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HIV-related traumatic stress symptoms in AIDS caregiving family dyads.
This study assesses HIV-related traumatic stress symptoms in 135 AIDS caregiving family dyads in which the caregiver is a midlife or older mother or wife, and the care-recipient is her HIV-infected adult son or husband. Symptoms of HIV-related traumatic stress can be reliably measured in these dyads, with both caregivers and care-recipients reporting avoidant and intrusive thoughts. Among care-recipients, high symptoms are associated with high daily living assistance requirements, low dyadic adjustment, and high constriction of social activities. Among caregivers, high symptoms of traumatic stress are associated with being HIV positive, feeling overloaded by caregiving demands, and perceiving high levels of HIV stigma. Caregiving mothers and wives may feel traumatized 'courtesy' of their loved one's HIV infection, the caregiving scenario, or the resultant caregiving stress. | {
"pile_set_name": "PubMed Abstracts"
} |
Assessment of brain metabolites change during visual sexual stimulation in healthy women using functional MR spectroscopy.
Numerous functional magnetic resonance imaging (fMRI) studies demonstrated the key brain areas associated with visual sexual arousal. However, the changes in brain metabolites involved in sexual stimuli have not been reported. This study utilized functional MR spectroscopy (fMRS) to evaluate the changes in brain metabolites associated with sexual arousal induced by stimulation with erotic video clips in healthy women. Twenty-three healthy, right-handed women (38.4 ± 10.0 years) participated in (1) H-fMRS and fMRI studies. T1 and T2 MR images were used for voxel localization of the anterior cingulate gyrus, which is one of the most important key centers associated with sexual arousal. The changes of brain metabolites were measured using (1) H-fMRS during time-course activation: "before," "during," and "after" visual sexual stimulation. The time-course variation of the brain metabolites was analyzed by the repeated-measures analysis of variance. The CVmean of all the metabolites had <30% (range, 9-29%). The ICCs of α-glutamine-glutamate (Glx), choline (Cho), β·γ-Glx, N-acetylaspartate (NAA) and lactate (Lac) all exceeded 0.6. However, myo-inositol (mI) and lipid (Lip) were <0.6. The concentration of brain metabolites including α-Glx, β·γ-Glx, Cho, and Lac comparatively increased significantly during visual sexual stimulation. (1) H-fMRS, for the first time, was applied to assess the brain metabolic changes during visually-evoked sexual arousal. The fMRS outcomes in relation to functional MRI data will be useful to understand the neural mechanism associated with sexual arousal. | {
"pile_set_name": "PubMed Abstracts"
} |
Thermal Modeling for the Next Generation of Radiofrequency Exposure Limits: Commentary.
This commentary evaluates two sets of guidelines for human exposure to radiofrequency (RF) energy, focusing on the frequency range above the "transition" frequency at 3-10 GHz where the guidelines change their basic restrictions from specific absorption rate to incident power density, through the end of the RF band at 300 GHz. The analysis is based on a simple thermal model based on Pennes' bioheat equation (BHTE) (Pennes 1948) assuming purely surface heating; an Appendix provides more details about the model and its range of applicability. This analysis suggests that present limits are highly conservative relative to their stated goals of limiting temperature increase in tissue. As applied to transmitting devices used against the body, they are much more conservative than product safety standards for touch temperature for personal electronics equipment that are used in contact with the body. Provisions in the current guidelines for "averaging time" and "averaging area" are not consistent with scaling characteristics of the bioheat equation and should be refined. The authors suggest the need for additional limits on fluence for protection against brief, high intensity pulses at millimeter wave frequencies. This commentary considers only thermal hazards, which form the basis of the current guidelines, and excludes considerations of reported "non-thermal" effects of exposure that would have to be evaluated in the process of updating the guidelines. | {
"pile_set_name": "PubMed Abstracts"
} |
The Recovery Assessment Scale - Domains and Stages (RAS-DS): Sensitivity to change over time and convergent validity with level of unmet need.
There is a need for robust outcome measures for use in psychiatric services. Particularly lacking are self-rated recovery measures with evidence of sensitivity to change. This study was established to examine the convergent validity and sensitivity to change over time (responsiveness) of the Recovery Assessment Scale - Domains and Stages (RAS-DS), in comparison to level of unmet need as measured by the Camberwell Assessment of Need - Short Appraisal Scale (CANSAS). Convergent validity was examined through cross-sectional correlations between 540 CANSAS and RAS-DS scores collected on the same day for the same individuals. Sensitivity to change was examined using correlations between change scores in CANSAS and RAS-DS where both were collected on the same day and the two time points were separated by 90 days or more (n = 498). Results demonstrated moderate, significant cross-sectional correlations between CANSAS scores and RAS-DS total and domain scores and between change scores of both instruments. Results suggest that the RAS-DS is sensitive enough to detect change over time. Only moderate correlation between the RAS-DS and CANSAS suggests that, in the context of recovery-oriented service provision, it is important to measure self-reported recovery in addition to level of unmet needs. | {
"pile_set_name": "PubMed Abstracts"
} |
Gay aging.
The oldest of the baby boomers (boomers) were age 63 in 2009 and on the verge of retirement. This cohort has had a history of making societal changes throughout its life cycle, and it is unlikely that retirement, as we know it, will remain unscathed. This article highlights two events-the Stonewall Inn riots and two prominent professional associations removing homosexuality from their list of personality disorders-and how they occurred early enough in the gay boomers life cycle to change their attitudes, behaviors, and lifestyles. This article introduces the reader to a broad array of facts, research findings, and issues that inform the topic of gay aging. A summary of the discrimination and legal concerns affecting the gay community are also highlighted. Two influential community programs are identified: Services and Advocacy for Gay Elders (SAGE) and the American Society on Aging's LGBT Aging Issues Network (LAIN). Gerontological educators need to be sensitive to the needs, desires, and resources of the coming cohort of gay boomers, who are more likely to advocate for responsive services, organizations, and policies than the current cohort of gay older adults. | {
"pile_set_name": "PubMed Abstracts"
} |
Lipid modifications of trimeric G proteins.
G protein alpha subunits and beta gamma dimers are covalently modified by lipids. The emerging picture is one in which attached lipids provide more than just a nonspecific "glue" for sticking G proteins to membranes. We are only beginning to understand how different lipid modifications of different G protein subunits affect specific protein-protein interactions and localization to specific cellular sites. In addition, regulation of these modifications, particularly palmitoylation, can provide new ways to regulate signals transmitted by G proteins. | {
"pile_set_name": "PubMed Abstracts"
} |
Expression of DBC1 and SIRT1 is associated with poor prognosis of gastric carcinoma.
SIRT1 (silent mating-type information regulation 2 homologue 1) expression has been reported to predict poor survival in some cancers. We therefore investigated the expression levels of SIRT1 and its negative regulator, DBC1 (deleted in breast cancer 1), in gastric cancer patients. We evaluated immunohistochemical expression of DBC1, SIRT1, and p53 using 3-mm tumor cores from 177 gastric cancer patients for tissue microarray. Positive expressions of DBC1 and SIRT1 were seen in 62% (109 of 177) and in 73% (130 of 177) of patients, respectively. Expression of DBC1 was significantly correlated with tumor stage (P = 0.007), lymph node metastasis (P < 0.001), tumor invasion (P = 0.001), venous invasion (P = 0.001), histologic types (P < 0.001), p53 expression (P < 0.001), and SIRT1 expression (P < 0.001). SIRT1 expression was also significantly correlated with tumor stage (P < 0.001), lymph node metastasis (P < 0.001), tumor invasion (P < 0.001), histologic types (P < 0.001), and p53 expression (P = 0.001). In addition, expression of DBC1 was significantly associated with shorter overall survival and relapse-free survival by univariate analysis (P < 0.001 and P < 0.001, respectively). SIRT1 expression was also significantly associated with shorter overall survival and relapse-free survival by univariate analysis (P = 0.001 and P = 0.001, respectively). Multivariate analysis showed that tumor stage and expression of DBC1 were independent prognostic factors significantly associated with overall survival and relapse-free survival. This study shows that expression of DBC1 and SIRT1 is a significant prognostic indicator for gastric carcinoma patients. | {
"pile_set_name": "PubMed Abstracts"
} |
15N T2' relaxation times of bacteriorhodopsin transmembrane amide nitrogens.
15N T(2)' relaxation times of bacteriorhodopsin (BR) amide nitrogens were determined in the temperature range from 40 to -60 degrees C using a Hahn echo pulse sequence and proton decoupling during the echo and detection times. Using oriented membrane samples, with their bilayer normal parallel to the external magnetic field, the (15)N amide nitrogens belonging to the transmembrane helices could be selected for the analysis. The experiments were performed on purple membrane fragments (in which BR is organized in a 2D crystalline network) and on BR reconstituted into dimyristoylphosphatidylcholine at a 1:150 molar ratio (in which BR is in a freely diffusing monomeric state at 40 degrees C and in an aggregated state at 4 degrees C and below). The results are discussed in terms of helix dynamics, mosaic spread and resolution of the (15)N spectra for the various samples and experimental conditions. | {
"pile_set_name": "PubMed Abstracts"
} |
Association of 25-hydroxyvitamin D3)levels in adult New Zealanders with ethnicity, skin color and self-reported skin sensitivity to sun exposure.
The study aim was to determine the contribution of ethnicity, objectively measured skin color and skin reaction-to-sun exposure to variations in 25-hydroxyvitamin D(3) [25(OH)D(3) ]. A multiethnic sample (European, Maori, Pacific and Asian) of 503 adult volunteers aged 18-85 years, recruited from Auckland and Dunedin in New Zealand, answered a questionnaire on sun exposure and self-defined ethnicity. Skin color was measured using a spectrophotometer and the Individual Typology Angle (ITA) calculated. A blood sample was collected 4 weeks later to measure 25(OH)D(3). 25(OH)D(3) was associated with ethnicity, but not self-reported skin reaction-to-sun exposure. Amongst the ethnic groups, Asians had the lowest mean 25(OH)D level (37.0 nmol L(-1)) and Europeans with lighter colored skin had the highest (57.9 nmol L(-1)). An association also was seen between 25(OH)D(3) and skin color, with an increase of 2-3 nmol L(-1) per 10° increase in ITA value, indicating higher 25(OH)D(3) with lighter skin color; but much of this association disappeared after adjusting for ethnicity. In contrast, ethnicity remained associated with 25(OH)D(3) after adjusting for ITA skin color and skin reaction-to-sun exposure. These results indicate that self-defined ethnicity was a major determinant of variations in serum 25(OH)D(3), while objective measures of skin color explained relatively little additional variation. | {
"pile_set_name": "PubMed Abstracts"
} |
Are viruses associated with aphthae and oral vesiculo-erosive disorders?
Oral and maxillofacial surgeons in District General Hospitals in UK often carry the major workload of patients with chronic oral ulcerative conditions. Although the immunopathogenic basis of many of these is being unravelled, the aetiology is often unclear, though a role for viruses is increasingly suspected. This paper reviews the current evidence. | {
"pile_set_name": "PubMed Abstracts"
} |
Degenerate PCR primer design for the specific identification of rhinovirus C.
Human rhinovirus (HRV)-A and -B is a common cause of upper respiratory tract infections. Recently, a third species, HRV-C, was categorized based on molecular typing studies. The results showed that the HRV-C genome had diverged from that of HRV-A and -B. Despite its late identification, increasing evidence suggests that HRV-C causes more severe pathogenic infections than HRV-A or -B; however, a large amount of epidemiological data is required to confirm this association in different clinical settings. Consequently, a simple and rapid method for identifying HRV-C is required to expedite such epidemiological studies. Here, two degenerate primer sets (HEV and HRVC) were designed based on bioinformatic analyses. The HEV set targeting the fifth IRES domain sequence within the 5'-UTR, which is highly conserved among enteroviruses, was designed to detect all enteroviruses, whereas the HRVC set, which targeted the VP2 coding region, was designed to detect HRV-C alone. Both primer sets were tested against a panel of standard enteroviruses and clinical lavage samples. HEV detected all enteroviruses tested whereas HRVC was specific for HRV-C. Although the primer design strategy was confirmed with a limited number of samples, extensive tests are required to be applied in clinical settings. | {
"pile_set_name": "PubMed Abstracts"
} |
Abortion due to equine herpesvirus in southern Brazil.
We report an outbreak of abortion due to equine herpesvirus (EHV) in 5 mares between 9 and 11 months of gestation, from a herd of 22 Thoroughbred mares. Equine herpesvirus was isolated from extracts of the liver, spleen and thymus but not from the lungs of a 9-month fetus grown in Rabbit Kidney (RK13) cells. The virus was identified by electron microscopy, where virus particles could be seen in the nucleus of infected cells, and by the fluorescent antibody technique with polyclonal antibodies against the whole virus. Anamnesis, necropsy, histopathology, bacteriology, and virology data suggest that the abortions reported in this paper were due to equine herpesvirus. | {
"pile_set_name": "PubMed Abstracts"
} |
Arsenic and non-cirrhotic portal hypertension. A report of eight cases.
It was discovered that eight patients with complications of non-cirrhotic portal hypertension had received an arsenical preparation for psoriasis as Fowler's solution some years age. Seven of them were admitted for bleeding oesophageal varices. Upon admission, splenomegaly and hypersplenism were present. Liver tests were normal and palmar skin keratosis and melanosis were noted. Liver biopsy of six patients showed features of incomplete septal cirrhosis. Malignant skin lesions were present in half of the patients. One patient died from lung carcinoma and another from an ovarium neoplasm. Chronic arsenic intake should be actively looked for in all patients with psoriasis and non-cirrhotic portal hypertension. They should be followed up for many years for development of malignant lesions in skin, lung and liver. Liver abnormalities present in the biopsies are often minor and may escape detection. | {
"pile_set_name": "PubMed Abstracts"
} |
Oxidative stress inhibits ionomycin-mediated cell death in cortical neurons.
Thiol-proteases play important roles in many cellular processes, including maintenance of protein homeostasis and execution of cell death. Therefore, determining how this family of enzymes is regulated is critical for our understanding of both physiological and pathological conditions. Because these proteases require a reduced cysteine residue for activity, the cellular redox state plays a crucial role in regulating the activity of thiol proteases. Importantly, increased oxidative stress can result in the direct modification of the active site cysteine, leading to enzyme inactivation. This would suggest that oxidative stress that occurs during pathological insults could prolong cell survival by preventing the execution of thiol-protease-dependent cell death pathways. To test this hypothesis, cultured rat cortical neurons were treated with the oxidizing agent diamide or doxorubicin in the presence or absence of the calcium ionophore ionomycin. Under normoxic conditions, ionomycin treatment resulted in approximately 70% cell death, which was prevented by addition of the calpain-selective inhibitor benyzloxycarbonyl-Leu-Leu-Tyr fluoromethylketone. Similarly, pretreatment of neurons with either oxidant was also protective. Protection resulting from oxidative stress was not due to new protein synthesis, insofar as cycloheximide did not affect oxidant-mediated protection. Interestingly, treatment with the antioxidant Trolox to reverse or prevent oxidative stress blocked the protective effects of both oxidants against ionomycin-induced cell death. We interpret these findings to suggest that, in diseases or conditions in which oxidative stress is increased, the ability of thiol-proteases to execute cell death pathways fully is decreased and may prolong cell survival. | {
"pile_set_name": "PubMed Abstracts"
} |
Investigations from external quality assurance programs reveal a high degree of variation in the laboratory identification of coagulation factor inhibitors.
The laboratory has a key role in the initial detection of factor inhibitors and an ongoing role in the measurement of inhibitor titers during the course of inhibitor eradication therapy. The most commonly seen factor inhibitors are those directed against factor VIII (FVIII), usually detected either with the original or the Nijmegen-modified Bethesda assay. In addition, several circumstances can arise in which the laboratory may test samples that potentially reflect false identification of factor inhibitors. These include lupus anticoagulants and other events generally related to preanalytical variables, including incorrect sample presentations. This article reviews each of these elements, largely from the perspective of cross-laboratory studies undertaken within the framework of external quality assurance (EQA), a peer-laboratory process that aims to assess the ongoing performance of groups of similar laboratories. This review details the experience of the Royal College of Pathologists of Australasia Haematology Quality Assurance Program, and it also reflects on the experience of other EQA organizations. Our analysis reveals a wide variety of test practice among inhibitor testing laboratories, a wide variation in detected inhibitor levels in cross-tested samples, and substantial evidence of false-positive and false-negative detection of factor inhibitors. These findings hold some significance for the clinical management of patients affected by these inhibitors. There is still much need for standardization and improvement in factor inhibitor detection, and we hope that this report provides a basis for future improvements in this area. | {
"pile_set_name": "PubMed Abstracts"
} |
Purification and characterization of a rat liver enzyme that hydrolyzes valaciclovir, the L-valyl ester prodrug of acyclovir.
Valaciclovir is an oral prodrug of the antiherpetic agent acyclovir. An enzyme that hydrolyzes valaciclovir to acyclovir, valaciclovir hydrolase (VACVase), was purified from rat liver and characterized. VACVase was a basic (pI 9.4) protein associated with mitochondria. It was monomeric and had a molecular mass of 29 kDa. Amino acid sequences of six VACVase peptides, including its NH2 terminus (13 amino acids) and accounting for approximately 20% of its complete sequence, were not found in the SwissProt protein data base. VACVase hydrolyzed other amino acid esters of acyclovir in addition to valaciclovir (kcat/Km = 58 mM-1 s-1), with a preference for the L-alanyl (kcat/Km = 226 mM-1 s-1) and L-methionyl (kcat/Km = 200 mM-1 s-1) esters. It did not hydrolyze other types of esters or numerous di- and tripeptides and aminoacyl-beta-naphthylamides. Hydrolysis of valaciclovir by VACVase was not inhibited by amastatin, antipain, aprotinin, bestatin, chymostatin, E-64, EDTA, ebelactone A, ebelactone B, elastatinal, leupeptin, pepstatin, or phosphoramidon. It was neither inhibited nor activated by Ca2+, Co2+, Mg2+, Mn2+, or Zn2+. Therefore, this enzyme is not a typical esterase or peptidase and, to our knowledge, it has not been described previously. Its physiological function is not known; however, it may play a significant role in the biotransformation of valaciclovir to acyclovir. | {
"pile_set_name": "PubMed Abstracts"
} |
Increase in bax expression and apoptosis are associated in Huntington's disease progression.
Huntington's disease (HD) is a hereditary dominant neurodegenerative disorder and the progression of the disease may be associated with apoptosis and altered expression of apoptotic proteins. The aim of this study was to investigate gene expression of bax and bcl-2 in tissues from R6/1 transgenic (TGN) mice of different ages (3, 6 and 9 months). The mRNA expression was investigated and related to apoptotic cells measured by TUNEL. Results showed a significant and progressive increase in bax levels in the cortex of TGN (from 10 to 33%) when compared to control (CT) (8 to 20%) mice with 3, 6 and 9-month-old. The increase in bax was correlated with the elevation in the number of apoptotic nuclei, especially in the cortex of 6 (10%) and 9 (18%)-month-old mice. Increase in bax expression might be related to an apoptotic induction which contributes to the HD progression. | {
"pile_set_name": "PubMed Abstracts"
} |
Polarons and charge carrier solvation on conjugated carbon chains: a comparative ab initio study.
We study accommodation of an excess charge carrier on long even-N polyynic oligomers C(N)H(2) due to displacements of the underlying carbon lattice and polarization of the surrounding solvent in the context of carrier self-localization into a polaronic state. Spatial patterns of bond-length alternation, excess charge and spin densities are compared as derived with Hartree-Fock and two hybrid density functional theory methods (BHandHLYP and B3LYP) in conjunction with the polarizable continuum model. Quite distinct resulting pictures of carrier accommodation are found when contributions from different interactions are analyzed. Solvation robustly acts to promote excess charge localization. | {
"pile_set_name": "PubMed Abstracts"
} |
Sexual Dimorphism: How Female Cells Win the Race.
Sexual dimorphisms are established by sex determination pathways and are maintained during regeneration of adult tissues. Two recent studies in Drosophila elucidate the contribution of cell-autonomous and endocrine mechanisms to the establishment and maintenance of growth dimorphism in larvae and the adult intestine. | {
"pile_set_name": "PubMed Abstracts"
} |
Effects of carbamazepine and valproate on brainstem auditory evoked potentials in epileptic children.
Brainstem auditory evoked potentials (BAEPs) were recorded in 18 epileptic children receiving carbamazepine and 10 epileptic children receiving valproate. BAEPs were recorded before the administration of antiepileptic drugs (AEDs) and 13 months later during which the children received AEDs. Statistical analysis of peak latencies and interpeak intervals of waves I-III-V were made. Carbamazepine treatment resulted in prolongation of peak latencies of waves I-III-V and interpeak intervals I-III and I-V. Valproate monotherapy, on the other hand, caused no consistent changes on BAEP. On the basis of these results we suggest that chronic carbamazepine therapy exerts a suppressive influence on the auditory pathways, both peripherally at the level of the cochlea and/or auditory nerve, and centrally at the brainstem. | {
"pile_set_name": "PubMed Abstracts"
} |
Synthesis and properties of endohedral C60 encapsulating molecular hydrogen.
We report the details of our study to synthesize a new endohedral fullerene, H2@C60, in more than 100 mg quantities by closure of the 13-membered ring orifice of an open-cage fullerene using four-step organic reactions. The 13-membered ring orifice in a previously synthesized open-cage fullerene incorporating hydrogen in 100% yield was reduced to a 12-membered ring by extrusion of a sulfur atom at the rim of the orifice, and the ring was further reduced into an eight-membered ring by reductive coupling of two carbonyl groups also at the orifice. Final closure of the orifice was completed by a thermal reaction. Purification of H2@C60 was accomplished by recycle HPLC. A gradual downfield shift of the NMR signal for the encapsulated hydrogen observed upon reduction of the orifice size was interpreted based on the gauge-independent atomic orbital (GIAO) and the nucleus-independent chemical shift (NICS) calculations. The spectral as well as electrochemical examination of the properties of H2@C60 has shown that the electronic interaction between the encapsulated hydrogen and outer C60 pi-system is quite small but becomes appreciable when the outer pi-system acquires more than three extra electrons. Four kinds of exohedral derivatives of H2@C60 were synthesized. The tendency in the shift of the NMR signal of the inner hydrogen was found to be quite similar to that observed for the 3He NMR signal of the corresponding derivatives of 3He@C60. | {
"pile_set_name": "PubMed Abstracts"
} |
Exposure guidelines for magnetic fields.
The powerful magnetic fields produced by a controlled fusion experiment at Lawrence Livermore National Laboratory (LLNL) necessitated the development of personnel-exposure guidelines for steady magnetic fields. A literature search and conversations with active researchers showed that it is currently possible to develop preliminary exposure guidelines for steady magnetic fields. An overview of the results of past research into the bioeffects of magnetic fields was compiled, along with a discussion of hazards that may be encountered by people with sickle-cell anemia or medical electronic and prosthetic implants. The LLNL steady magnetic-field exposure guidelines along with a review of developments concerning the safety of time-varying fields were also presented in this compilation. Guidelines developed elsewhere for time varying fields were also given. Further research is needed to develop exposure standards for both steady or time-varying fields. | {
"pile_set_name": "PubMed Abstracts"
} |
Acute neonatal suppurative parotitis: case reports and review.
We describe two cases of neonatal suppurative parotitis caused by Staphylococcus aureus. Only 32 cases of neonatal suppurative parotitis (72% male) have been described in the English literature in the last 35 years. Thirty-eight percent were premature babies, only 41% were febrile and the causative agent in most cases was S. aureus. Recovery was achieved in 78% of the patients with antibiotic therapy without drainage. | {
"pile_set_name": "PubMed Abstracts"
} |
[Ductal carcinoma in situ in dynamic MR-mammography at 1.5 T].
To define the value of contrast-enhanced MR mammography in ductal carcinoma in situ (DCIS). In a group of 35 patients with DCIS, the results of MR imaging were compared to histopathology and immunohistochemistry in a retrospective study. In 35 patients with DCIS, a signal enhancement was found in 25 cases (72%). In 15 of these cases, the signal time curve was typical for malignancy. The other 10 patients had non-specific signal curves. Six of 35 patients (11%) had no enhancement within the tumour region. Four of 35 patients (11%) had bilateral diffuse signal increase, and regions of DCIS could not be identified clearly. Three DCIS were visualised exclusively by MR mammography. The configuration of signal enhancement was sharp (32%), unsharp (48%) or dendritic (20%). DCIS of the comedo type showed a significantly higher enhancement than the non-comedo type. A significant correlation between the grade of vascularisation in immunohistochemistry and signal enhancement in MR mammography could not be demonstrated. Dynamic MR mammography does not reliably visualise DCIS. | {
"pile_set_name": "PubMed Abstracts"
} |
[Susceptibility and R plasmids conjugation tests for 44 strains of gram negative bacilli in a burn unit].
44 strains of 9 species Gram negative bacilli were isolated and identified in a burn unit, among them 25 strains were from patients and 19 from ward environment. All strains were tested for susceptibility to antibiotics and R plasmids. Using both agar dilution and disc diffusion methods to test susceptibility to 12 kinds of antibiotics, namely, Streptomycin Chloramphenicol, Tetracycline, Ampicillin, Kanamycin, Gentamycin, Nalidixic acid, Amikacin Rifampin, Carbenicillin, Cefazolin and Polymyxin, we found that all 44 strains were susceptible to Rifampin and Polymyxin. To the other 10 kinds of antibiotics, the susceptibilities varied. 40 strains of bacteria (91%) were resistant to 3 kinds or more of antibiotics, i.e, multiple resistant bacteria, 2 strains resistant to 2 kinds of antibiotics (4.6%), and 2 strains susceptible to all 12 kinds of antibiotics (4.6%). The multiple resistant strains consisted of 9 strains (22.5%) of R plasmid-harboured bacteria, Pseudomonas aeruginosa 2 strains, Citrobacter 4 strains, Proteins 1 strain, Enterobacter aerogenes 1 strain and Escherichia coli 1 strain. All the R plasmids carried the marks of resistance to chloramphenicol, tetracycline, ampicillin, kanamycin, gentamycin, streptomycin, and carbenicillin, but no one carried marks of resistance to Cefazolin and Amikacin indicating that drug-resistance of the last two antibiotics might not be mediated by R plasmids. Two strains of Citrobacter freundii isolated from 2 patients and showing susceptibility to all antibiotics were induced to be Rifampin-resistance (Rif) strains without changing their original biological characters. They both could receive the R plasmids of the multiple resistance strains one from patient and the other from ward environment.(ABSTRACT TRUNCATED AT 250 WORDS) | {
"pile_set_name": "PubMed Abstracts"
} |
Survival of abutment teeth used for telescopic abutment retainers in removable partial dentures.
This retrospective clinical study investigated the survival of 385 abutment teeth retaining 117 removable partial dentures with 3 types of telescopic abutment retainers. Within a mean service time of 6.26 years, 8.8% of 385 abutment teeth were extracted. Cox regression analysis revealed a significantly higher risk of tooth loss for posterior teeth (odds ratio: 2.985) and for teeth with root canal treatment (odds ratio: 3.298), whereas age, sex, and number and type of telescopic retainer had no influence on survival. Root canal-treated teeth did not show a higher fracture rate, excluding this as an explanation for an increased risk of tooth loss. | {
"pile_set_name": "PubMed Abstracts"
} |
The feasibility of triple-drug chemotherapy combination in older adult patients with oesophagogastric cancer: a randomised trial of the Arbeitsgemeinschaft Internistische Onkologie (FLOT65+).
We evaluated the feasibility and tolerability of triple- versus double-drug chemotherapy in elderly patients with oesophagogastric cancer. Patients aged 65 years or older with locally advanced or metastatic oesophagogastric cancer were stratified and randomised to infusional 5-FU, leucovorin and oxaliplatin without (FLO) or with docetaxel 50 mg/m(2) (FLOT) every 2 weeks. The study is registered at ClinicalTrials.gov, identifier NCT00737373. One hundred and forty three (FLO, 71; FLOT, 72) patients with a median age of 70 years were enrolled. The triple combination was associated with more treatment-related National Cancer Institute Common Toxicity Criteria (NCI-CTC) grade 3/4 adverse events (FLOT, 81.9%; FLO, 38.6%; P<.001) and more patients experiencing a ≥10-points deterioration of European Organization for Research and Treatment of Cancer Quality of Life (EORTC QoL) global health status scores (FLOT, 47.5%; FLO 20.5%; p=.011). The triple combination was associated with more alopecia (P<.001), neutropenia (P<.001), leukopenia (P<.001), diarrhoea (P=.006) and nausea (P=.029).). No differences were observed in treatment duration and discontinuation due to toxicity, cumulative doses or toxic deaths between arms. The triple combination improved response rates and progression-free survival in the locally advanced subgroup and in the subgroup of patients aged between 65 and 70 years but not in the metastatic group or in patients aged 70 years and older. The triple-drug chemotherapy was feasible in elderly patients with oesophagogastric cancer. However, toxicity was significantly increased and QoL deteriorated in a relevant proportion of patients. The study was partially funded by Sanofi-Aventis. | {
"pile_set_name": "PubMed Abstracts"
} |
Value-based formulas for purchasing. PEHP's designated service provider program: value-based purchasing through global fees.
In many circles, managed care and capitation have become synonymous; unfortunately, the assumptions informing capitation are based on a flawed unidimensional model of risk. PEHP of Utah has rejected the unidimensional model and has therefore embraced a multidimensional model of risk that suggests that global fees are the optimal purchasing modality. A globally priced episode of care forms a natural unit of analysis that enhances purchasing clarity, allows providers to more efficiently focus on the Marginal Rate of Technical Substitution, and conforms to the multidimensional reality of risk. Most importantly, global fees simultaneously maximize patient choice and provider cost consciousness. | {
"pile_set_name": "PubMed Abstracts"
} |
The many illusions of the Müller-Lyer: comparisons of the wings-in and wings-out illusions and manipulations of standard and dot forms.
The assumed role of peripheral distortion mechanisms in both wings-in and wings-out Müller-Lyer illusions was investigated by requiring subjects to reproduce the central extent of standard Müller-Lyer figures and dot variations. Illusory magnitude of the line and dot variations was also examined with increasing wing length and wing angle. A reduction in the overestimation for the wings-out illusion occurred with the removal of intersecting lines; the dot variations evidenced a significant overestimation effect. In contrast, no reliable decrease in underestimation was found with the removal of intersecting lines in the wings-in illusion, and both standard and dot variations were significantly underestimated. These results support a conclusion that the wings-in and wings-out Müller-Lyer illusions are two distinct illusions, and may be differentially determined at the loci of distortion within the visual system. Parallel changes in illusory magnitude were noted with configural manipulations of standard and dot wings-out illusions. However, standard and dot forms of the wings-in illusion were not equivalently affected by equivalent configural manipulations, which suggests that they are different illusions. Thus, the use of the wings-in dot variation to separate empirically peripheral from non-peripheral distortion mechanisms may be ill-advised. | {
"pile_set_name": "PubMed Abstracts"
} |
Extracellular superoxide dismutase induced by dopamine in cultured astrocytes.
Under some pathological conditions in brain, a large amount of superoxide anion (O(2)(-)) is produced, causing various cellular damages. Among three isozymes of superoxide dismutase (SOD), extracellular (EC)-SOD should play a role to detoxify O(2)(-) in extracellular space; however, a little is known about EC-SOD in brain. Although dopamine (DA) stored in the synaptic vesicle is stable, the excess leaked DA is spontaneously oxidized to yield O(2)(-) and reactive DA quinones, causing damages of dopaminergic neurons. In the present study, we examined the effects of DA on SOD expression in cultured rat cortical astrocytes. By means of RT-PCR, all mRNA of three isozymes of SOD could be detected; however, only EC-SOD was increased by DA exposure for 24 h, dose-dependently. The expression of EC-SOD protein and the cell-surface SOD activity in astrocytes also increased with 100 μM DA exposure. The increase of EC-SOD mRNA by DA was inhibited by a DA transporter inhibitor, GBR12909, whereas it was not changed by DA receptor antagonists, SKF-83566 (D1) and haloperidol (D2). Furthermore, a monoamine oxidase inhibitor, pargyline, and antioxidants, N-acetyl-L-cysteine and glutathione, also did not affect the DA-induced expression of EC-SOD mRNA. On the other hand, an inhibitor of nuclear factor kappaB (NF-κB), ammonium pyrrolidine-1-carbodithioate, suppressed the DA-induced expression of EC-SOD mRNA. These results suggest that DA incorporated into the cells caused the induction of EC-SOD mRNA followed by the enhancements of EC-SOD protein level and the enzyme activity, and that NF-κB activation is involved in the mechanisms of the EC-SOD induction. The regulation of EC-SOD in astrocytes surrounding dopaminergic neurons may contribute to the defensive mechanism against oxidative stress in brain. | {
"pile_set_name": "PubMed Abstracts"
} |
A quinoxaline based N-heteroacene interfacial layer for efficient hole-injection in quantum dot light-emitting diodes.
A series of N-heterocyclic quinoxaline derivatives was successfully synthesized and applied as hole transport layers in quantum dot light-emitting diodes (QLEDs). By inducing sp(2) N-atoms into the quinoxaline backbone, the electron affinity of the obtained material was enhanced, and its optical properties and bandgap became tunable. Quinoxaline based N-heteroacenes show a narrow bandgap, high thermal stability, and aligned film morphology. The resulting N-heteroacene polymer based QLED exhibits superior performance to poly(9-vinylcarbazole) based QLED. This study presents a strategy towards the design of novel N-rich molecules for the fabrication of QLEDs with improved performance. | {
"pile_set_name": "PubMed Abstracts"
} |
A splice variant of the Wilms' tumour suppressor Wt1 is required for normal development of the olfactory system.
Neuronal lineage formation in the developing olfactory epithelium has been extensively studied at the cellular level, but little is known about the genes that control proliferation and differentiation of neuronal progenitor cells. Here, we report that the Wilms' tumour zinc-finger protein, Wt1, is required for normal formation of the olfactory epithelium. Wt1 was detected by immunohistochemistry in the developing olfactory epithelium of wild-type embryos between gestational days E9.5 and E18.5. Embryos with complete lack of Wt1 and embryos with selective ablation of the alternatively spliced Wt1(+KTS) isoform both had thinner olfactory epithelia and fewer neuronal progenitor cells than do normal animals. Mash1 and neurogenin 1, two basic helix-loop-helix transcription factors with critical functions during olfactory neuron development, were reduced in the Wt1(+KTS)-/- mutants compared with the wild-type mice. Stable expression of the Wt1(+KTS) isoform, but not of the Wt1(-KTS) variant, upregulated Mash1 mRNA and protein in vitro. The olfactory epithelia of mouse embryos, which lacked the Wt1(-KTS) protein, appeared normal. However, formation of the neural retina was severely impaired in the Wt1(-KTS)-/- mutants. These findings demonstrate that the Wt1(+KTS) protein, which has been proposed to play a role in mRNA processing, acts upstream of Mash1 to promote the development of the olfactory epithelium. Furthermore, neuron formation depends on distinct functions of alternatively spliced Wt1 products in the embryonic retina and the olfactory epithelium. | {
"pile_set_name": "PubMed Abstracts"
} |
Galectin 15 (LGALS15) functions in trophectoderm migration and attachment.
Galectin 15 (LGALS15) is expressed specifically by the endometrial luminal epithelium (LE) of the ovine uterus in concert with blastocyst growth, elongation, and implantation. LGALS15 contains a predicted carbohydrate recognition domain (CRD) as well as LDV and RGD recognition sequences for integrin binding. Studies tested the hypothesis that LGALS15 is a secreted regulator of blastocyst development, as well as growth, migration, adhesion, and apoptosis of trophoblast. Bovine embryos were produced in vitro by standard conditions, and putative zygotes were cultured in the presence of recombinant ovine LGALS15. Rates of embryo cleavage and blastocyst formation were not affected by LGALS15. LGALS15 moderately increased proliferation of ovine trophectoderm (oTr) cells. Staurosporine elicited apoptosis of oTr cells, which could be partially inhibited by LGALS15. Migration of oTr cells was stimulated by LGALS15 that was dependent on Jun N-terminal kinase (JNK). A dose-dependent increase in oTr cell attachment to LGALS15 was found that could be inhibited by cyclic GRGDS, but not GRADS, peptides. Mutation of the LDVRGD integrin binding sequence of LGALS15 to LADRAD decreased its ability to promote oTr cell attachment, whereas mutation of the CRD had little effect. LGALS15 induced formation of robust focal adhesions in oTr cells that was abolished by mutation of the LDVRGD sequence. Collectively, these results support the hypothesis that LGALS15 stimulates trophectoderm cell migration and attachment via integrin binding and activation which are critical to blastocyst elongation and implantation. | {
"pile_set_name": "PubMed Abstracts"
} |
Strategies to prevent aspiration-related pneumonia in tube-fed patients.
It is improbable that aspiration and aspiration-pneumonia can be entirely prevented, but application of one or more of the strategies described in this article probably can reduce these potentially life threatening conditions. Fortunately, many of these strategies are relatively easy and inexpensive to incorporate into routine care. | {
"pile_set_name": "PubMed Abstracts"
} |
DETERMINATION OF NATIONAL DIAGNOSTIC REFERENCE LEVELS IN COMPUTED TOMOGRAPHY EXAMINATIONS OF IRAN BY A NEW QUALITY CONTROL-BASED DOSE SURVEY METHOD.
National diagnostic reference levels (NDRLs) of Iran were determined for the four most common CT examinations including head, sinus, chest and abdomen/pelvis. A new 'quality control (QC)-based dose survey method', as developed by us, was applied to 157 CT scanners in Iran (2014-15) with different slice classes, models and geographic spread across the country. The NDRLs for head, sinus, chest and abdomen/pelvis examinations are 58, 29, 12 and 14 mGy for CTDIVol and 750, 300, 300 and 650 mGy.cm for DLP, respectively. The 'QC-based dose survey method' was further proven that it is a simple, accurate and practical method for a time and cost-effective NDRLs determination. One effective approach for optimization of the CT examination protocols at the national level is the provision of an adequate standardized training of the radiologists, technicians and medical physicists on the patient radiation protection principles and implementation of the DRL concept in clinical practices. | {
"pile_set_name": "PubMed Abstracts"
} |
Effect of hypotension induced with sodium nitroprusside on canine coronary arterial flow.
In seven dogs anaesthetized with pentobarbitone, coronary and pulmonary artery blood flows were measured using electromagnetic flow meters. The infusion of a 0.01% solution of sodium nitroprusside caused an initial small increase in mean coronary artery flow which returned to control as the arterial pressure decreased. No changes were noted in cardiac output nor were further changes observed in coronary flow. Heart rate was increased consistently during the hypotension and left ventricular dp/dt max was reduced as were coronary and total peripheral resistances. There were no significant changes in myocardial or total body oxygen extraction or consumption. | {
"pile_set_name": "PubMed Abstracts"
} |
Action of mung bean nuclease on supercoiled PM2 DNA.
Single strand specific mung bean nuclease was used to probe for regions of altered secondary structure in supercoiled PM2 DNA. Supercoiled DNA is cleaved greater than or equal to 10,000 times faster than the relaxed topoisomer. Catalytic quantities of enzyme convert supercoiled DNA to both nicked-circular and unit length linear forms at pH 5 but to predominantly the nicked-circular form near neutral pH. At the elevated enzyme concentrations required to cleave relaxed DNA, unit length linear DNA and smaller fragments are produced from pH 5 to 7. One nick per supercoiled DNA molecule is introduced at pH 6.6. The nicks are repairable by DNA ligase and are not strand-specific. Snake venom phosphodiesterase selectively cleaves the strand opposite the nicks, permitting restriction endonuclease mapping. The nicks occur at three specific sites. Sites at 0.75 and 0.76 map units are cleaved with equal frequency, while a site at 0.82 is cleaved less frequently. The former sites map near one of the eight known early denaturation regions of PM2 DNA, while the latter does not. Since most early denaturation sites are not cleaved, sites other than these dA + dT-rich regions may be the preferred locations of strand unwinding and separation in supercoiled PM2 DNA. | {
"pile_set_name": "PubMed Abstracts"
} |
Interferon-beta-1a treatment has a positive effect on quality of life of relapsing-remitting multiple sclerosis: results from a longitudinal study.
The impact of interferon beta (IFNβ) therapy on a patient's quality of life (QoL) has not been completely clarified. This multicenter, independent, observational and longitudinal study was aimed to evaluate the impact of different pharmaceutical formulations of IFNβ-1a on QoL in patients affected by relapsing-remitting multiple sclerosis (RRMS). The multiple sclerosis quality of life-54 questionnaire was used to assess patients' QoL. 394 (66%) patients completed the two-year study; 152 were treated with IFNβ-1a i.m. weekly injected (group a), 152 with IFNβ-1a 44 μg s.c. injected three times a week (group b) and 90 were untreated (group c). After two years, a significant increase was found in the physical health composite score (Δ = +3.1 in group a, Δ = +3 in group b, p < 0.05 in both), mental health composite score (Δ = +4.7 in group a, Δ = +5.5 in group b, p < 0.001 in both), in eight MSQoL sub-items of group a and in seven sub-items in group b. Conversely, the untreated group showed a slight decrease in seven domains. The variable "therapy with DMDs" was associated with improved QoL. QoL of RRMS could be improved by IFNβ-1a treatment, despite natural history data which seem to demonstrate that QoL could get worse over the time. | {
"pile_set_name": "PubMed Abstracts"
} |
Physiological demands of standing and wheelchair fencing in able-bodied fencers.
The purpose of this study was to determine the cardiorespiratory demands of standing and wheelchair (seated) fencing in a group of able-bodied fencers during simulated competitive bouts. Participants were ten male able-bodied fencers of regional level with previous training experience in wheelchair fencing. After a standardized warm-up, participants performed two series of simulated competitive épée bouts (5 and 15 touches) in a random order, either while standing or while sitting in a wheelchair. Expired gas was analyzed for oxygen consumption (V̇O2) and respiratory exchange ratio (RER) and heart rate were continually monitored. Energy expenditure (EE) was subsequently calculated. V̇O2, HR and EE peak responses were greater during standing than seated fencing (P<0.05). Mean V̇O2 during all ST bouts (5- and 15-touch) was 43% greater than in wheelchair fencing (44.2±7.8 vs. 25.1±5.4 mL/kg/min). Mean HR during the standing 5- and 15-touch bouts was 91±20% and 84±7%, respectively, of that recorded during the seated bouts. HR, V̇O2 and EE data also indicated that the 15-touch bouts were more physiologically demanding than the 5-touch bouts (P<0.01). The HR-V̇O2 relationship was similar between both fencing modes. The duration of the 5- and 15-touch bouts were shorter for the seated than the standing bouts (P<0.01). The physiological demands of wheelchair fencing are lower than those for standing fencing. Furthermore, the physiology of 5 versus 15-touch bouts, similar to those undertaken in fencing competition, also differs. | {
"pile_set_name": "PubMed Abstracts"
} |
Increased intravenous fluid intake and the course of labor in nulliparous women.
To compare the effect of 2 regimens of intravenous fluid therapy on the course of labor. In a prospective, randomized, double-blind study of 300 nulliparous pregnant women at term conducted at a teaching hospital, 153 women received 125 mL and 147 received 250 mL of intravenous fluid per hour. The groups were matched and analysis was done using the t, chi(2), and Fisher exact tests. P<0.05 was considered statistically significant. In the group that received intravenous fluid at a rate of 250 mL per hour the mean+/-S.D. duration of labor was significantly shorter (253+/-97 vs. 386+/-110 min; P = 0.0001), the frequency of labor lasting both more than 10h and more than 15 h was statistically lower (4.8% vs. 13.8%; P=0.001 and 0% vs. 4.5%; P=0.02, respectively), and the frequency of oxytocin administration was significantly lower (8.1% vs. 20.4%; P=0.001). There was a trend toward a lower frequency of cesarean deliveries in the 250-mL group (16% vs. 22.8%; P=0.1). A greater volume per hour of intravenous fluid than is commonly administered to nulliparous women in active labor is associated with significantly shorter duration of labor and lower frequency of both prolonged labor and oxytocin administration. | {
"pile_set_name": "PubMed Abstracts"
} |
Induction of the hypoxia-inducible factor system by low levels of heat shock protein 90 inhibitors.
The heterodimeric hypoxia-inducible factor-1 (HIF-1) is involved in key steps of tumor progression and therapy resistance and thus represents an attractive antitumor target. Because heat shock protein 90 (HSP90) plays an important role in HIF-1alpha protein stabilization and because HSP90 inhibitors are currently being tested in clinical phase I trials for anticancer treatment, we investigated their role as anti-HIF-1alpha agents. Surprisingly, low-dose (5-30 nmol/L) treatment of HeLa cells with three different HSP90 inhibitors (17-AAG, 17-DMAG, and geldanamycin) increased HIF-1-dependent reporter gene activity, whereas higher doses (1-3 micromol/L) resulted in a reduction of hypoxia-induced HIF-1 activity. In line with these data, low-dose treatment with HSP90 inhibitors increased and high-dose treatment reduced hypoxic HIF-1alpha protein levels, respectively. HIF-1alpha protein stabilized by HSP90 inhibitors localized to the nucleus. As a result of HSP90-modulated HIF-1 activity, the levels of the tumor-relevant HIF-1 downstream targets carbonic anhydrase IX, prolyl-4-hydroxylase domain protein 3, and vascular endothelial growth factor were increased or decreased after low-dose or high-dose treatment, respectively. Bimodal effects of 17-AAG on vessel formation were also seen in the chick chorioallantoic membrane angiogenesis assay. In summary, these results suggest that dosage will be a critical factor in the treatment of tumor patients with HSP90 inhibitors. | {
"pile_set_name": "PubMed Abstracts"
} |
Zintl ions, cage compounds, and intermetalloid clusters of Group 14 and Group 15 elements.
For a long time, Zintl ions of Group 14 and 15 elements were considered to be remarkable species domiciled in solid-state chemistry that have unexpected stoichiometries and fascinating structures, but were of limited relevance. The revival of Zintl ions was heralded by the observation that these species, preformed in solid-state Zintl phases, can be extracted from the lattice of the solids and dissolved in appropriate solvents, and thus become available as reactants and building blocks in solution chemistry. The recent upsurge of research activity in this fast-growing field has now provided a rich plethora of new compounds, for example by substitution of these Zintl ions with organic groups and organometallic fragments, by oxidative coupling reactions leading to dimers, oligomers, or polymers, or by the inclusion of metal atoms under formation of endohedral cluster species and intermetalloid compounds; some of these species have good prospects in applications in materials science. This Review presents the enormous progress that has been made in Zintl ion chemistry with an emphasis on syntheses, properties, structures, and theoretical treatments. | {
"pile_set_name": "PubMed Abstracts"
} |
Association between oral malodor and adult periodontitis: a review.
Bad breath has a significant impact on our daily social life to those who suffer from it. The majority of bad breath originates within the oral cavity. However, it is also possible that it can come from other sources such as gastric-intestine imbalance. The term "oral malodor" is used to describe a foul or offensive odor emanating from the oral cavity, in which proteolysis, metabolic products of the desquamating cell, and bacterial putrefaction are involved. Recent evidence has demonstrated a link between oral malodor and adult periodontitis. The process of developing bad breath is similar to that noted in the progression of gingivitis/periodontitis. Oral malodor is mainly attributed to volatile sulfur compounds (VSC) such as hydrogen sulfide, methyl mercaptan and dimethyl sulfide. The primary causative microbes are gram-negative, anaerobic bacteria that are similar to the bacteria causing periodontitis. These bacteria produce the VSC by metabolizing different cells/tissues (i.e., epithelial cells, leukocytes, etc.) located in saliva, dental plaque, and gingival crevicular fluid. Tongue surface is composed of blood components, nutrients, large amounts of desquamated epithelial cells and bacteria, suggesting that it has the proteolytic and putrefactive capacity to produce VSC. One of the challenges in dealing with oral malodor is to identify a reliable test for detecting bad breath. The purposes of this review article were: (1) to correlate the relationship between oral malodor and adult periodontitis; (2) to analyze current malodor tests and discuss available treatment regimens. | {
"pile_set_name": "PubMed Abstracts"
} |
Apelin signaling modulates splanchnic angiogenesis and portosystemic collateral vessel formation in rats with portal hypertension.
Angiogenesis is a pathological hallmark of portal hypertension. Although VEGF is considered to be the most important proangiogenic factor in neoangiogenesis, this process requires the coordinated action of a variety of factors. Identification of novel molecules involved in angiogenesis is highly relevant, since they may represent potential new targets to suppress pathological neovascularization in angiogenesis-related diseases like portal hypertension. The apelin/APJ signaling pathway plays a crucial role in angiogenesis. Therefore, we determined whether the apelin system modulates angiogenesis-driven processes in portal hypertension. Partial portal vein-ligated rats were treated with the APJ antagonist F13A for seven days. Splanchnic neovascularization and expression of angiogenesis mediators (Western blotting) was determined. Portosystemic collateral formation (microspheres), and hemodynamic parameters (flowmetry) were also assessed. Apelin and its receptor APJ were overexpressed in the splanchnic vasculature of portal hypertensive rats. F13A effectively decreased, by 52%, splanchnic neovascularization and expression of proangiogenic factors VEGF, PDGF and angiopoietin-2 in portal hypertensive rats. F13A also reduced, by 35%, the formation of portosystemic collateral vessels. This study provides the first experimental evidence showing that the apelin/APJ system contributes to portosystemic collateralization and splanchnic neovascularization in portal hypertensive rats, presenting a potential novel therapeutic target for portal hypertension. | {
"pile_set_name": "PubMed Abstracts"
} |
Design, construction, and evaluation of a dynamic MR compatible cardiac left ventricle model.
Development of magnetic resonance (MR) sequences is important to answer clinical questions and to overcome current limitations. To meet the challenges of cardiac MR, dynamic and reproducible testing conditions are required. We aimed at developing a dynamic MR-compatible cardiac left ventricle model that imitates myocardial tissue properties and simulates dynamic motion. A dynamic left ventricle silicone model was designed to match myocardial T(1) and T(2) relaxation times. Silicone mixtures were explored to replicate T(2) values of myocardial edema. A controllable piston pump was constructed to produce pulsatile flow paradigms. They were validated against flow sensors and MR data, including SSFP-based and phase-contrast-based sequences. A dedicated software interface was developed for the control. Model dimensions represented cardiac left ventricle dimensions of healthy men. The range of end diastolic volumes was 85-175 ml, depending on the driven stroke volume. Stroke volume quantification for flow paradigms of 30∕60∕90∕120 ml resulted in 29.2∕57.6∕88.8∕118.4 ml by MR volumetry, 29.6∕59.9∕89.4∕119.0 ml by phase contrast measurements, and 29.9∕60.4∕91.1∕120.9 ml by flow meter revealing consistency. The system accurately replicated physiological and pathophysiological flow paradigms. The silicon model exhibited T(1) of 1002 ± 8 ms, T(2) of 58 ± 1 ms. Signal intensities (a.u.) of the ventricle model were 128 ± 23 for FGRE (vs 138 ± 17 in vivo) and 1156 ± 37 for b-SSFP (vs 991 ± 96 in vivo). T(2) of 75 ± 2 ms was achieved for the myocardial pathology. We developed a controllable left ventricle model resembling MR signal characteristics of human myocardium, including pathological conditions, and allowing for the replication of contraction and flow paradigms. | {
"pile_set_name": "PubMed Abstracts"
} |
Homology modeling of the multicopper oxidase Fet3 gives new insights in the mechanism of iron transport in yeast.
Fet3, the multicopper oxidase of yeast, oxidizes extracellular ferrous iron which is then transported into the cell through the permease Ftr1. A three-dimensional model structure of Fet3 has been derived by homology modeling. Fet3 consists of three cupredoxin domains joined by a trinuclear copper cluster which is connected to the blue copper site located in the third domain. Close to this site, which is the primary electron acceptor from the substrate, residues for a potential iron binding site could be identified. The surface disposition of negatively charged residues suggests that Fet3 can translocate Fe(3+) to the permease Ftr1 through a pathway under electrostatic guidance. | {
"pile_set_name": "PubMed Abstracts"
} |
Characterization of N alpha-acetyl methionyl human growth hormone formed during expression in Saccharomyces cerevisiae with liquid chromatography and mass spectrometry.
We found a new variant of human growth hormone (hGH) from the recombinant hGH expression process in Saccharomyces cerevisiae. The variant was identified as N(alpha)-acetyl methionyl hGH which may be formed by N(alpha)-acetylation of met-hGH during the intracellular expression of hGH in S. cerevisiae. The variant was isolated from manufacturing process of LG Life Sciences' hGH product. The variant was subjected to trypsin digestion and RP-HPLC analysis, resulting in a delayed retention time and an increased mass (173 Da) of T1 tryptic peptide. The amino acid composition and amino acid sequence of the peptide showed the same result with T1 peptide of met-hGH except the N-terminal modification on methionine in the variant peptide. With collision induced dissociation (CID) experiments of the variant T1 tryptic peptide, we found the sequence and the a(1) fragment of N-terminal residue matched with those of acetyl-methionyl hGH. Within our production process, we produce the methionyl hGH first and then use the aminopeptidase to cut the N-terminal methionine. So the acetylation may inhibit the aminopeptidase to remove methionine and produces N(alpha)-acetyl methionyl hGH. And the biological activity of the variant was comparable to one of the unmodified hGH when tested by rat weight gain bioassay. | {
"pile_set_name": "PubMed Abstracts"
} |
Adjuvant therapy of colon cancer: a review.
Colon cancer is a common cause of cancer-related mortality. Complete surgical resection of the primary tumor and/or select metastatic lesions can be curative in many patients. The risk of recurrence after resection can be predicted by pathologic staging. Large prospective randomized trials over the past 2 decades have clearly shown an increased overall survival for patients with resected stage III colon cancer who are treated with adjuvant 5-fluorouracil-based chemotherapy. The benefit of adjuvant chemotherapy for patients with stage II disease remains controversial. There is indirect evidence to support adjuvant chemotherapy after resection of metastatic disease. Locoregional approaches such as radiation, hepatic arterial infusion, or portal vein chemotherapy remain investigational. Adjuvant immunotherapy with monoclonal antibodies is emerging as a therapeutic option that might complement chemotherapy. Future challenges include improving adjuvant chemotherapy with the addition and/or substitution of new agents, resolving which subset of patients with stage II and resected stage IV colon cancer might benefit from therapy, validating the benefit of immunotherapy, and investigating locoregional therapies compared with systemic therapy. | {
"pile_set_name": "PubMed Abstracts"
} |
The bimolecular structure of aquahexa-μ-chlorido-μ4-oxido-tris(tetrahydrofuran-κO)tetracopper(II)-hexa-μ-chlorido-μ4-oxido-tetrakis(tetrahydrofuran-κO)tetracopper(II)-tetrahydrofuran (2/1/4).
The title bimolecular structure, [Cu4Cl6O(C4H8O)3(H2O)]2[Cu4Cl6O(C4H8O)4] · 4C4H8O, at 100 K has monoclinic (P21/c) symmetry. The structure contains nine symmetry-independent molecules expressed in simplest molecular form as 6[Cu4Cl6O(C4H8O)3(H2O) · 2(C4H8O)]:3Cu4Cl6O(C4H8O)4. The compound exhibits a supercell (smaller than the unit cell based on weak reflections) structure due to pseudotranslational symmetry. The structure displays O-H...O hydrogen bonding between bound water ligands and tetrahydrofuran (THF) solvent molecules. The structure exhibits disorder for 12 of the THF molecules, of which seven are ligated to Cu and five are hydrogen bonded to H2O ligands. | {
"pile_set_name": "PubMed Abstracts"
} |
Epicubenol and Ferruginol induce DC from human monocytes and differentiate IL-10-producing regulatory T cells in vitro.
Epicubenol and 19-hydroxyferruginol (Ferruginol) are sesquiterpenes isolated from the black heartwood of Cryptomeria japonica. Dendritic cells (DC) are specialized antigen-presenting cells that monitor the antigenic environment and activate naïve T cells. The role of DC is not only to sense danger but also to tolerize the immune system to antigens encountered in the absence of maturation/inflammatory stimuli. In this study, we attempted to investigate the effects of Epicubenol and Ferruginol on the phenotypic and functional maturation of human monocytes-derived DC in vitro. Human monocytes were cultured with GM-CSF and IL-4 for 6 days under standard conditions, followed by another 2 days with Epicubenol or Ferruginol. The expression levels of CD1a, CD83, and HLA-DR as expressed by mean fluorescence intensity (MFI) on Epicubenol-primed DC or Ferruginol-primed DC were enhanced. Allogeneic Epicubenol-primed DC or Ferruginol-primed DC co-cultured with naïve T cells at 1:5 ratio, secreted IL-10 and TGF-beta, but little IL-4. Moreover, T cells that develop in co-culture of Epicubenol-primed DC or Ferruginol-primed DC and naïve T cells at 1:5 ratio suppressed the proliferation of autologous T cells at Treg cells: Ttarget cells and this suppression of proliferation was inhibited by anti-IL-10 mAb. The expression of FoxP3 mRNA on T cells that develop in co-culture of Epicubenol-primed DC or Ferruginol-primed DC and naïve T cells was lower. From these results, Epicubenol and Ferruginol may induce IL-10-producing Treg 1 cells from naïve T cells by modulating DC function. It seems that Epicubenol and Ferruginol appear to be a target for tolerance after transplantation and in autoimmune diseases. | {
"pile_set_name": "PubMed Abstracts"
} |
Esophageal moniliasis. A review of common and less frequent characteristics.
Invasion of the esophagus by Candida albicans probably occurs more frequently than the reported cases suggest. The disease usually occurs following immunosuppression but may occur after antibiotic therapy. It is heralded by the sudden onset of severe pain and dysphagia, and recovery or death from dissemination may occur. Roentgenographically, impaired motility is much more prominent than disordered motility or spasm. Narrowing, a cobblestone epithelium, and later, erosions and ulcerations are seen. Antifungal agents are adequate therapy. | {
"pile_set_name": "PubMed Abstracts"
} |
Key two-component regulatory systems that control biofilm formation in Pseudomonas aeruginosa.
Biofilm formation in P. aeruginosa is a highly regulated process that proceeds through a number of distinct stages. This development is controlled by a wide range of factors, of which two-component systems (TCSs) play a key role. In this review, we focus on some of the TCSs that regulate the switch from a motile to a sessile bacterial lifestyle, either via the production of extracellular appendages or by the production of exopolysaccharides. Extracellular appendages, such as flagella, type IV pili and Cup fimbriae are often involved in the initial attachment of bacteria to a surface. In P. aeruginosa, many of these surface structures are regulated by TCSs, and some systems regulate more than one type of appendage. Furthermore, the production of exopolysaccharides, such as Pel and Psl, is required for P. aeruginosa biofilm formation. The regulation of Pel and Psl is post-transcriptionally repressed by RsmA, the activity of which is controlled by a complex regulatory system involving several sensor kinases and accessory components. Furthermore, the Rsm system is a major control system that inversely regulates factors involved in motility and acute infection on one hand, and factors involved in biofilm formation and chronic infection on the other hand. Finally, a series of TCSs has recently been discovered that regulates biofilm development in a stage-specific manner. Taken together, these complex regulatory networks allow the bacterium to respond appropriately to diverse environmental stimuli, and increased knowledge of their mechanisms and signals could be of great importance in the design of novel antibacterial strategies. | {
"pile_set_name": "PubMed Abstracts"
} |
Inducible expression of noggin selectively expands neural progenitors in the adult SVZ.
Multipotent, self-renewing stem cells are present throughout the developing nervous system remaining in discrete regions of the adult brain. In the subventricular zone (SVZ) signaling molecules, including the bone morphogenetic proteins and their secreted inhibitor, noggin appear to play a critical role in controlling neural stem cell (NSC) behavior. To examine the function of this signaling pathway in the intact nervous system, we developed a transgenic mouse model in which noggin expression can be induced specifically in NSC via a nestin-driven reverse tetracycline-controlled transactivator (rtTA). In adult animals, the induction of noggin expression promotes the proliferation of neural progenitors in the SVZ, and shifts the differentiation of B cells (NSC) from mature astrocytes to transit amplifying C cells and oligodendrocyte precursor cells without depleting the NSC population. Noggin expression significantly increases neuronal and oligodendrocyte differentiation both in vivo and in vitro when NSCs are grown as neurospheres. These results demonstrate that noggin/BMP interactions tightly control cell fate in the SVZ. | {
"pile_set_name": "PubMed Abstracts"
} |
Assessment of the Price-Volume Agreement Program in South Korea.
The Price-Volume Agreement Program (PVAP) was promulgated in 2007 in South Korea as the first attempt to adjust drug pricing according to total consumption in order to contain drug expenditure. This study was designed to assess the impact of the PVAP on diabetes drug expenditure for a period of a 10-year period (2003-2012) using claims data from the National Health Insurance Service. We estimated a multilevel mixed-effects linear regression model by comparing the level of total monthly diabetes drug expenditure for drugs subject to PVAP and existing drugs after adjusting the average differences in drug expenditure before and after the PVAP. The monthly total expenditure for drugs that were newly listed through the PVAP (negotiation drugs) was 7.03% higher on average compared to that for existing drugs, controlling for the baseline differences in expenditure before and after the PVAP. This increase was observed in all four subgroups of diabetes drugs, including sitagliptin, vildagliptin, exenatide, and others. The growth rate of total diabetes drug expenditure was reduced after the PVAP despite the sustained escalation of expenditure levels, which may imply that the PVAP has the potential to be an effective tool for drug expenditure control in the long term. | {
"pile_set_name": "PubMed Abstracts"
} |
Water-borne Bacillus licheniformis infection in mice.
A water-borne Bacillus licheniformis infection was associated with depressed haemoglobin content, white cell and platelet count. The epidemic was resolved by changing from tanked to mains water supply. | {
"pile_set_name": "PubMed Abstracts"
} |
Monocyte chemoattractant protein-1 (MCP-1) gene transduction: an effective tumor vaccine strategy for non-intracranial tumors.
Recently, there has been renewed interest in the concept of tumor vaccines using genetically engineered tumor cells expressing a variety of cytokines to increase their immunogenicity. Human MCP-1 (JE) is a potent chemoattractant and activator of monocytes and T lymphocytes and thus a good candidate gene for a tumor vaccine. We therefore evaluated the efficacy of vaccines consisting of irradiated tumor cells transduced with the murine MCP-1 gene in the syngeneic 9L gliosarcoma brain tumor model. 9L cell lines stably expressing murine MCP-1 (9L-JE) and control cell lines expressing neomycin 3' phosphotransferase (9L-Neo) were generated by infection with a Moloney murine leukemia retroviral vector. Fisher 344 rats were immunized with intradermal injections of 5 x 10(5) or 2 x 10(6) irradiated (5000 cGy) 9L-JE, 9L-Neo, and wild-type 9L (9L-WT) cells. Two weeks later immunized and non-immunized animals were challenged with various doses of intradermal (5 x 10(6)-5 x 10(7) or intracerebral (2 x 10(4)-5 x 10(5) 9L-WT cells. Intradermal tumors grew in all non-immunized animals. No tumors grew in animals immunized with irradiated 9L-JE or 9L-Neo cells and challenged with inocula of fewer than 5 x 10(5) 9L-WT cells. With higher inocula up to 10(7) cells, tumors appeared in all the animals, but subsequently regressed in the immunized animals. Tumors in animals immunized with 9L-JE were always smaller than tumors in the other groups. In addition, only the 9L-JE vaccine protected against tumor inocula of 5 x 10(7) cells. Thus vaccination with MCP-1-expressing cells was able to protect animals against at least a 100-fold larger number of challenge tumor cells than vaccination with control cells. In contrast to studies with intradermal tumors, immunization with 9L-JE and 9L-Neo produced only minimal protection against intracerebral tumors. There was no significant difference between the 9L-JE and 9L-Neo vaccines in intracerebral challenge. This study suggests that tumor vaccines expressing cytokine genes such as MCP-1 can increase the antitumor response. However, the protective effect of these vaccines appears to be largely limited to intradermal tumors rather than intracerebral tumors. | {
"pile_set_name": "PubMed Abstracts"
} |
Immunocytochemical localization of creatine kinase M in canine myocardial cells: most creatine kinase M is distributed in the A-band.
The localization of creatine kinase (CK) M in canine myocardium was immunocytochemically studied by a direct immunoperoxidase method. Specific antiserum against CK-M was produced in rabbits immunized with canine CK-MM. An anti-CK-M Fab'-horseradish peroxidase conjugate was prepared by the maleimide method. Frozen sections prepared from fixed canine myocardium were stained with the conjugate and observed by light and electron microscopy. In light microscopy of longitudinal sections, CK-M showed a cross-striated pattern consisting of distinct broad and narrow brown bands. Immunoelectron microscopy revealed that the regions of the broad and narrow brown bands corresponded to the A-band and the Z-line, respectively. Most CK-M in the A-band was associated with the thick fibers, and a small amount of CK-M was found in the M-line. These findings suggest that ATP regeneration from the ADP produced by myosin ATPase is related to the participation of this CK associated with the thick fibers rather than that of the M-line-bound CK. Creatine kinase M was also found in the sarcolemmal membrane, the membranes of the sarcoplasmic reticulum, and the mitochondrial outer and inner membranes. This report provides new information for understanding the physiological role of the phosphorylcreatine shuttle in the myocardial energy transport system. | {
"pile_set_name": "PubMed Abstracts"
} |
An estimation of the incidence of noma in north-west Nigeria.
Noma (cancrum oris, stomatitis gangrenosa) is a quickly spreading orofacial gangrene in children, caused by a combination of malnutrition, debilitation because of concomitant diseases (measles) and intraoral infections. The global incidence of noma in the world is uncertain. By comparing large numbers of noma patients and cleft lip patients in a large referral hospital for these disorders in Sokoto, Nigeria, we calculated the incidence of noma in north-west Nigeria as 6.4 per 1000 children. Extrapolation of this incidence to the developing countries bordering the Sahara Desert (the noma belt of the world) gives an incidence of 25,600 for that region and a global incidence of 30,000-40,000. Noma is a good biological parameter of extreme poverty, and hence a global monitoring system for noma can be justified. Though economic progress is the most effective preventive measure against noma, medical prevention by vaccination programmes against measles should be enhanced as well. | {
"pile_set_name": "PubMed Abstracts"
} |
Vitamin A excess alters membrane flow in rat liver.
Pulse-chase methodology with [35S]methionine as label was employed to determine flow kinetics through the endoplasmic reticulum-Golgi apparatus-(lysosome-) secretory vesicle-plasma membrane export route in livers of animals receiving vitamin A excess by gavage. Overall fraction composition determined by morphometry and by analyses of marker enzymes was unchanged by vitamin administration. The vitamin modified the pattern of flow of proteins through the Golgi apparatus to the cell surface and to lysosomes. Altered flux was evidenced by a markedly reduced rate of labeling of lysosomes and a slightly increased rate of labeling of both total membrane proteins of the plasma membrane and of a specific membrane glycoprotein GP80. Also reduced was overall labeling of the Golgi apparatus. Differences in the rate or routes of trafficking of glycoproteins through the Golgi apparatus together with altered opportunities for processing might account for some of the alterations in glycoconjugate glycosylation associated with excess vitamin A administration. | {
"pile_set_name": "PubMed Abstracts"
} |
Use of the pulmonary autograft for mitral replacement: short- and medium-term experience.
In an effort to find a suitable mitral substitute for our young rheumatic patients who cannot follow a proper anticoagulation regimen for life, we resorted to an old concept reported by one of the authors (D.N.R.) in 1967. This report summarizes our experience with the Ross-mitral operation to date. Between 19 June 1997 and 27 June 2000, 43 patients with rheumatic valve disease underwent the Ross-mitral operation. Two patients were excluded because of graft stenosis detected at the end of the procedure for which the autograft had to be sacrificed. Of the remaining 41 patients 29 were female, and the age range was 12--57 years (median 39 years). The autograft was incorporated within a Dacron tubing, with a pericardial collar attached to its proximal end. The conduit was sutured distally to the excised mitral annulus; the pericardium was attached proximally to the atrial wall in 36 patients, and was used simply to cover the Dacron tubing in five patients. The pulmonary artery was replaced with a pulmonary or aortic homograft, or with a pulmonary xenograft. There were two hospital fatalities from a cerebrovascular accident and a lung injury, and two postoperative myocardial infarctions. There were five late deaths, two due to bacterial endocarditis, one due to excessive bleeding at reoperation for a paravalvular leak, and two not related to the procedure. A phenomenon of 'autograft stenosis' occurred intraoperatively in four recent consecutive patients that probably resulted from our use, for the first time, of softer Dacron tubing material. This was repaired in two of the four patients. Echocardiography confirmed excellent functioning of all 34 autografts of surviving patients up to 36 months postoperatively (mean follow-up 18.2 months). Two patients remain in functional Class III status, one due to left heart failure following myocardial infarction, and the other due to recurrent tricuspid insufficiency. We believe that the mitral pulmonary autograft is a worthwhile alternative to mechanical prostheses in developing countries. | {
"pile_set_name": "PubMed Abstracts"
} |
Interactions between metal ions and carbohydrates: the coordination behavior of neutral erythritol to zinc and europium nitrate.
The single crystals of coordinated complexes of neutral erythritol (C4H10O4) with zinc nitrate and europium nitrate were synthesized and studied using FT-IR and single crystal X-ray diffraction analysis. In the structure of Zn(NO3)2.C4H10O4, ZnEN (E denotes erythritol, N represents nitrate), Zn2+ is coordinated to four hydroxyl groups from two erythritol molecules and two oxygen atoms from two nitrates. Two Zn2+ are connected by one erythritol molecule to form Zn(C4H10O4)(NO3)2 chain, and layers formed by above chain pile to produce 3D structures. In the structure of Eu(NO3)3.C4H10O4.C2H5OH, EuEN, Eu3+ is 10-coordinated by six oxygen atoms from three nitrate ions, three hydroxyl groups from one erythritol molecule and one hydroxyl group from ethanol. In the above erythritol complexes, two hydroxyl groups of erythritol coordinate to one metal ion and the other two to another metal ion or erythritol acts as three-hydroxyl groups donor. The OH groups of erythritol act as ligand to coordinate to metal ions on one hand, one the other hand, OH groups form hydrogen bonds network to build three-dimensional structures. | {
"pile_set_name": "PubMed Abstracts"
} |
A simple test of one minute heart rate variability during deep breathing for evaluation of sympatovagal imbalance in hyperthyroidism.
Heart rate variability is a sensitive marker of cardiac sympathetic activity. To determine whether long-term hyperthyroidism induced by thyroxine suppressive therapy affects HRV. Nineteen patients treated with suppressive doses of thyroxin for thyroid cancer and 19 age-matched controls were enrolled. Thyroid function tests and 1 minute HRV were performed on all subjects and the results were compared between the groups. The 1 minute HRV was analyzed during deep breathing and defined as the difference in beats/minute between the shortest and the longest heart rate interval measured by eletrocardiographic recording during six cycles of deep breathing. One minute HRV during deep breathing was significantly lower among thyroxine-treated patients compared to healthy controls (25.6 +/- 10.5 vs. 34.3 +/- 12.6 beats/min, P < 0.05). There were no significant differences in mean, maximal and minimal heart rate between the groups. Thyroxine therapy administered for epithelial thyroid cancer resulted in subclinical hyperthyroidism and significantly decreased HRV due to autonomic dysfunction rather than basic elevated heart rate. | {
"pile_set_name": "PubMed Abstracts"
} |
Altered Bcl-2 and Bax expression is associated with cultured first trimester human cytotrophoblasts apoptosis induced by hypoxia.
Preeclampsia is associated with placental hypoxia at early gestation. We therefore investigated the effect of hypoxia on the apoptosis of cultured first trimester human cytotrophoblasts and the expression of apoptosis relevant proteins, Bcl-2 and Bax. First trimester human cytotrophoblasts were isolated and cultured under either standard or hypoxic conditions. Cellular apoptosis was monitored by TUNEL and Annexin V binding, and the expression of Bcl-2 and Bax was determined by Western blot analysis. Apoptosis increased significantly in cytotrophoblasts cultured for 24 h under hypoxic conditions in contrast with those cultured under standard conditions, meanwhile expression of Bcl-2 reduced, and that of Bax increased. These changes suggested that hypoxia induced apoptosis in cultured first trimester cytotrophoblasts with altered Bcl-2 and Bax expression. Further study is needed to explore the role of cytotrophoblasts apoptosis in hypoxia-induced maternal and fetal diseases. | {
"pile_set_name": "PubMed Abstracts"
} |
Distributions of HLA-DRB1/DQB1 alleles and haplotypes in the north-eastern Thai population: indicative of a distinct Thai population with Chinese admixtures in the central Thais.
The phenotype and gene frequencies of HLA class II alleles were studied in the North-eastern Thai population. Blood samples were collected from 100 unrelated healthy North-eastern Thais. The HLA-DRB1 and DQB1 genes were typed using the polymerase chain reaction--sequence specific primer (PCR-SSP) and polymerase chain reaction--sequence specific oligonucleotide probe (PCR-SSO) techniques. Twenty-six HLA-DRB1 and 11 DQB1 alleles were found in this population. DRB1*1202, 1502, 0405 and DQB1*0502/0504, 0301/0304 alleles were commonly found. Linkage disequilibrium analysis suggested the existence of 13 DR-DQ haplotypes. The DRB1*1502-DQB1*0501 haplotype was the most common. The DRB1*1106-DQB1*0301/0304 haplotype was found only in North-eastern Thais and not in other Thai populations. Comparative analysis of the HLA-DR/DQ alleles revealed differences in the distributions of these alleles amongst different ethnic groups. Interestingly, the distributions of HLA class II alleles in Central Thai, North-eastern Thai and Southern Chinese populations are similar. However, it appears that the distribution in the Central Thais is a mixture of those in Southern Chinese and North-eastern Thais, suggesting the existence of Thai-Chinese admixtures in the Central Thai population. This study provides basic information for further studies of the MHC in anthropology, organ transplantation and disease susceptibility in the North-eastern Thai population. | {
"pile_set_name": "PubMed Abstracts"
} |
Occupancy model of perceived numerosity.
Observers saw 234 different pairs of stochastically organized dot patterns and indicated which of the two patterns appeared to be more numerous. All of the data can be accounted for by supposing that the choice of the more numerous pattern is based on the determination of the occupancy indices of both patterns. Each dot is posited to have an impact upon its neighborhood in a constant occupancy radius R. The area of the stimulus plane occupied collectively by all dots provides a basis for judging relative numerosity; the pattern with the larger occupancy value is chosen as more numerous. The occupancy model, besides providing a general explanation of known numerosity illusions in strictly quantitative terms, can explain some puzzling aspects of numerosity perception. | {
"pile_set_name": "PubMed Abstracts"
} |
[The prediction of blood pressure after adrenalectomy in primary aldosteronism].
In 30-40% of patients with primary aldosteronism owing to adenoma, hypertension is not relieved even though a hyper-functioning adenoma has been completely removed. The purpose of this study is to determine whether the prognosis of hypertension can be evaluated pre-operatively in patients with primary aldosteronism. Thirteen patients (6 men, 7 women; 47 +/- 9 years old) with primary aldosteronism were studied and adrenalectomy was performed in all cases. The success of the operation was confirmed by the normalization of plasma renin activity (PRA), plasma aldosterone concentration (PAC) and serum potassium. Eight patients, 3 men and 5 women, whose blood pressure (BP) was reduced to below 140mmHg systolic and 90mmHg diastolic at one year after the operation were classified as "group N" and the other 5 cases, 3 men and 2 women, remained hypertensive and were classified as "group H". There were no significant differences in the age of the patients, duration of hypertension, pretreatment mean BP and severity of hypertension between the two groups. Thus, it is doubtful that the lack of improvement of hypertension is due to the irreversible damage of the small arteries. Although pretreatment BP was similar in the two groups, systolic BP after the administration of 200mg per day of spironolactone for one week was significantly reduced in group N, but not in group H. Moreover, a significant correlation was found between mean BP after treatment with spironolactone and post-operative mean BP in all subjects. Pretreatment PRA was significantly lower in group H.(ABSTRACT TRUNCATED AT 250 WORDS) | {
"pile_set_name": "PubMed Abstracts"
} |
Type 3 innate lymphoid cells are altered in colons of C57BL/6 mice with dioxin exposure.
Type 3 innate lymphoid cells (ILC3s) are distributed in the gut and regulate inflammation by secreting cytokines, including interferon (IFN)-γ and interleukin (IL)-17. The maintenance and function of ILC3s involve the activity of aryl hydrocarbon receptor (AhR), a potent ligand of which is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), one of the most toxic dioxin congeners. Thus, TCDD exposure might affect ILC3s. To obtain in vivo evidence supporting this notion, we exposed female C57BL/6 mice orally to TCDD (low/high doses: 0.1/10 μg/kg body weight) during pregnancy and lactation periods, and after the exposure, evaluated the mothers and offspring for alterations in ILC3 differentiation and function in the colon. ILC3 frequency among colonic lamina propria lymphocytes was preferentially diminished in the offspring, and, in parallel, the median fluorescence intensity (MFI) of retinoic acid receptor-related orphan receptor (ROR)γt, which is associated with ILC3 differentiation, was also decreased in ILC3s. Conversely, the percentages of two subsets of the cells, one positive for natural cytotoxicity receptor NKp46 and the other for IL-17a, were increased in TCDD-exposed mothers and offspring. Moreover, the percentage of IFN-γ+ ILC3s was increased specifically in the mothers, but this was in conjunction with a significant decrease in the MFI of IFN-γ, which suggests that the IFN-γ+ ILC3 subset was functionally altered. In conclusion, maternal exposure to TCDD suppresses ILC3 differentiation in the offspring and influences ILC3 function in distinct manners in the mother and offspring. Our study provides new insights into the intergenerational interference of dioxins in colonic ILC3s. | {
"pile_set_name": "PubMed Abstracts"
} |
Free impinging jet microreactors: controlling reactive flows via surface tension and fluid viscoelasticity.
We investigate the use of impinging free liquid jets as wall-free continuous microreactors. The collision of two reactant jets forming a free-standing thin liquid sheet allows us to perform rapid precipitation reactions to form colloidal particles, enhance micromixing, and master challenging reactions with very fast kinetics. To control the shape, size, and hydrodynamics of the impingement zone between the two liquid streams, it is crucial to understand the interplay among surface tension, fluid viscoelasticity, and reaction kinetics. Here, we study these aspects using model fluids, each illustrating a different physical effect of surface and bulk fluid properties. First, solutions of sodium dodecyl sulfate below, near, and above the critical micelle concentration are used to assess the role of static and dynamic surface tension. Second, we demonstrate how dilute solutions of high-molecular-weight polymers can be used to control the morphology of the free surface flow. If properly controlled, these effects can enhance the micromixing time scales to the extent that very rapid reactions can be performed with outstanding selectivity. We quantitatively assess the interplay between the free surface flow and reaction kinetics using parallel-competitive reactions and demonstrate how these results can be used to control the particle size in precipitation processes. | {
"pile_set_name": "PubMed Abstracts"
} |
Resolution of discordant HIV-1 protease resistance rankings using molecular dynamics simulations.
The emergence of drug resistance is a major challenge for the effective treatment of HIV. In this article, we explore the application of atomistic molecular dynamics simulations to quantify the level of resistance of a patient-derived HIV-1 protease sequence to the inhibitor lopinavir. A comparative drug ranking methodology was developed to compare drug resistance rankings produced by the Stanford HIVdb, ANRS, and RegaDB clinical decision support systems. The methodology was used to identify a patient sequence for which the three rival online tools produced differing resistance rankings. Mutations at only three positions ( L10I , A71IV, and L90M ) influenced the resistance level assigned to the sequence. We use ensemble molecular dynamics simulations to elucidate the origin of these discrepancies and the mechanism of resistance. By simulating not only the full patient sequences but also systems containing the constituent mutations, we gain insight into why resistance estimates vary and the interactions between the various mutations. In the same way, we also gain valuable knowledge of the mechanistic causes of resistance. In particular, we identify changes in the relative conformation of the two beta sheets that form the protease dimer interface which suggest an explanation of the relative frequency of different amino acids observed in patients at residue 71. | {
"pile_set_name": "PubMed Abstracts"
} |
Value of echocardiography for evaluation of the flow-dependent epicardial coronary vasodilation in vivo.
To assess the value of echocardiography for detection of the flow-dependent epicardial coronary vasodilation, the changes in internal diameter of the left anterior descending coronary arteries (LAD) induced by reactive hyperemia were studied by echocardiography in 12 health anesthetized open-chest dogs. Reactive hyperemia was induced by brief occlusion of the left anterior descending coronary artery for 30 s followed by rapid release. The two- dimensional images of the left anterior descending coronary artery before and after reactive hyperemia with and without intracoronary infusion of N(G)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase (NOS) were investigated. The internal diameter of LAD was measured and its percent change induced by reactive hyperemia was calculated. Our results showed that the internal diameter of LAD was 2.23 +/- 0.19 mm before intracoronary infusion of L-NAME (baseline). The internal diameter of LAD significantly increased to 2.52 +/- 0.24 mm (P < 0.01) after reactive hyperemia at baseline, and the percent change in internal diameter of LAD was (13.10 +/- 3.59)%. The internal diameter of LAD before and after reactive hyperemia under the condition of intracoronary infusion of L-NAME was not different from that before reactive hyperemia at baseline. The percent change in internal diameter of LAD was (1.07 +/- 2.97)%, and it was significantly lower than that at baseline (P < 0.001). We are led to conclude that the change in internal diameter of LAD responding to reactive hyperemia was detected sensitively by echocardiography, and this change was associated with endothelium-derived nitric oxide. | {
"pile_set_name": "PubMed Abstracts"
} |
Identification of new human CYP2C19 alleles (CYP2C19*6 and CYP2C19*2B) in a Caucasian poor metabolizer of mephenytoin.
A genetic polymorphism in the metabolism of the anticonvulsant drug S-mephenytoin has been attributed to defective CYP2C19 alleles. This genetic polymorphism displays large interracial differences with the poor metabolizer (PM) phenotype representing 2-5% of Caucasian and 13-23% of Oriental populations. In the present study, we identified two new mutations in CYP2C19 in a single Swiss Caucasian PM outlier (JOB 1) whose apparent genotype (CYP2C19*1/CYP2C19*2) did not agree with his PM phenotype. These mutations consisted of a single base pair mutation (G395A) in exon 3 resulting in an Arg132-->Gln coding change and a (G276C) mutation in exon 2 resulting in a coding change Glu92-->Asp. However, the G276C mutation and the G395A mutation resided on separate alleles. Genotyping tests of a family study of JOB1 showed that the exon 2 change occurred on the CYP2C19*2 allele, which also contained the known splice mutation in exon 5 (this variant is termed CYP2C19*2B to distinguish it from the original splice variant now termed CYP2C19*2A). The exon 3 mutation resided on a separate allele (termed CYP2C19*6). In all other respects this allele was identical to one of two wild-type alleles, CYP2C19*1B. The incidence of CYP2C19*6 in a European Caucasian population phenotyped for mephenytoin metabolism was 0/344 (99% confidence limits of 0 to 0.9%). Seven of 46 Caucasian CYP2C19*2 alleles were CYP2C19*2B(15%) and 85% were CYP2C19*2A. The Arg132Gln mutation was produced by site-directed mutatgenesis and the recombinant protein expressed in a bacterial cDNA expression system. Recombinant CYP2C19 6 had negligible catalytic activity toward S-mephenytoin compared with CYP2C19 1B, which is consistent with the conclusion that CYP2C19*6 represents a PM allele. Thus, the new CYP2C19*6 allele contributes to the PM phenotype in Caucasians. | {
"pile_set_name": "PubMed Abstracts"
} |
Automated lesion annotation during pulmonary vein isolation: influence on acute isolation rates and lesion characteristics.
Recovery of pulmonary vein (PV) conduction is a common mechanism of atrial fibrillation recurrence after PV isolation (PVI), underscoring the need for durable lesion formation. We aimed to evaluate the utility of an automated lesion annotation algorithm (ALAA) on acute isolation rates and resulting lesion characteristics. Fifty patients underwent PVI using a contact force (CF) sensing catheter and ALAA. Single antral circles around ipsilateral PVs were performed with ALAA-1 settings including catheter stability (range of motion ≤2 mm, duration >10 s). Target CF was 10-20 g but not part of ALAA-1 settings. If PV conduction persisted after circle completion, force over time was added to automated settings (ALAA-2). Emerging gaps were subsequently ablated, followed by re-assessment for PVI. ALAA-1 isolated 70 % of the left and 78 % of the right PVs using 756.3 ± 212.3 s (left) and 737.1 ± 145.9 s (right) of energy delivery. ALAA-2 settings identified 29 gaps in previously unisolated PVs, closure significantly increased isolation rates to 88 % of the left and 96 % of the right PVs with additional 325.4 ± 354.1 s (left) and 266.8 ± 279.5 s (right) of energy delivery (p = 0.001). Lesion characteristics significantly differed between ALAA-1 (n = 3521 lesions) and ALAA-2 (n = 3037 lesions) settings, and between isolated and non-isolated PV segments, particularly with respect to CF. Interlesion distances with ALAA-2 were significantly longer in the left superior, left superior-anterior, and right superior-posterior segments when compared to ALAA-1. Settings of an ALAA affect lesion characteristics reveal areas of insufficient lesion formation and influence acute effectiveness of PVI. Combination of CF and stability shows superior performance over stability alone. | {
"pile_set_name": "PubMed Abstracts"
} |
Involvement of long- and short-range signalling during early tendon development.
Tendons connect muscle to skeletal elements. Although tendons have been shown to originate from the lateral plate mesoderm, very little is known at the molecular level about how they are formed. We have found that two genes, Follistatin and Eph-A4, are expressed in regions associated with tendon formation in developing chick limbs. Follistatin is expressed near the tip of the digits and subsequently around the tendon, whereas Eph A4 transcripts were localized in a slightly more proximal region and later in the body of the tendon. Previous work has demonstrated that application of TGFbeta1 or TGFbeta2 to inter-digital regions or the removal of ectoderm in the foot plate induces ectopic cartilage formation, while removal of ectoderm or application of FGF to tips of developing digits leads to truncation. Here we show that TGFbeta1 or removal of ectoderm is also able to induce the expression of both Eph-A4 and Follistatin and that manipulations that cause truncations affect these genes. Thus cartilage and tendon development appear to be coordinated. Ectopic application of recombinant human Follistatin, an antgaonist of certain TGFbeta super-family proteins including Activin and Bmp-4, results in the loss of tendon, implicating signalling by TGFbeta super-family in the development of tendon during chick embryogenesis. Signalling by TGFbeta family members, antagonised by Noggin is known to regulate skeletal development. Thus we suggest that parallel pathways govern both skeletal and tendon patterning. | {
"pile_set_name": "PubMed Abstracts"
} |
Daptomycin for treatment of patients with bone and joint infections: a systematic review of the clinical evidence.
The treatment of bone and joint infections, mainly caused by Gram-positive pathogens, can be difficult and quite challenging since it frequently involves prolonged administration of antibiotics as well as appropriate surgical procedures. First-line drugs have failed in some cases to cure the underlying infection. We performed a systematic review of the available evidence to clarify further the effectiveness and safety of daptomycin in the treatment of bone and joint infections. Cure of infection was achieved in 43/53 cases (81.1%). The results of the reviewed articles are promising with regard to the effectiveness and safety profile of this new antibiotic for bone and joint infections that are not responsive to other traditionally used antimicrobial agents. Although these reports are encouraging, the relatively frequent emergence of antimicrobial resistance associated with prolonged administration of daptomycin should be considered seriously. | {
"pile_set_name": "PubMed Abstracts"
} |
Comparable prognostic impact of BNP levels among HFpEF, Borderline HFpEF and HFrEF: a report from the CHART-2 Study.
We aimed to compare the usefulness of plasma levels of B-type natriuretic peptide (BNP) for long-term risk stratification among patients with heart failure (HF) with preserved left ventricular ejection fraction (LVEF) (HFpEF), borderline HFpEF, and HF with reduced LVEF (HFrEF) in the same HF cohort. In the CHART-2 Study (N = 10,219), we categorized 4301 consecutive Stage C/D HF patients (mean age 68.7 years, female 32.4%) into 3 groups: HFpEF (LVEF ≥ 50%, N = 2893), borderline HFpEF (LVEF 40-50%, N = 666), and HFrEF (LVEF ≤ 40%, N = 742). During the median 6.3-year follow-up, all-cause deaths occurred in 887 HFpEF, 330 borderline HFpEF, and 330 HFrEF patients. Although median BNP levels increased from HFpEF, borderline HFpEF to HFrEF (85.3, 126 and 208 pg/ml, respectively, P < 0.001), the relationship between log2 BNP levels and the mortality risk was comparable among the 3 groups. As compared with patients with BNP < 30 pg/ml, those with 30-99, 100-299 and ≥ 300 pg/ml had comparably increasing mortality risk among the 3 groups (hazard ratio 2.5, 4.7 and 7.8 in HFpEF, 2.1, 4.2 and 7.0 in borderline HFpEF, and 3.0, 4.7 and 9.5 in HFrEF, respectively, all P < 0.001). BNP levels have comparable prognostic impact among HFpEF, borderline HFpEF, and HFrEF patients. | {
"pile_set_name": "PubMed Abstracts"
} |
[Effect of tobacco smoking on the incidence of recurrent myocardial infarction. A retrospective study of 208 cases].
Two hundred and eight patients, less than 60 years of age at the time of their first myocardial infarction (MI), which occurred between 1 July 1976 and 30 September 1982, and with a mean recurrence-free follow-up period of 3450 +/- 142 days, were included in a retrospective survey. This concerned the outcome of their coronary artery disease and the persistence of vascular risk factors, notably their tobacco consumption, the extent and forme of which was detailed. This study showed: 1) the mortality rate was 8.8%, 2) 78.4% of the patients smoked before their infarction, 3) 76% of the smokers stopped smoking after this event. The risk of recurrence of infarction was higher amongst smokers. After 5 years, 51.6 +/- 15% of the subjects who had not reduced their daily tobacco consumption had suffered another MI, versus 21.5 +/- 3% of those who had reduced it by 1 to 50%, 16.9 +/- 6% of those who had never smoked and only 10.5 +/- 6% of those who had reduced it by more than 50% or had stopped smoking (p less than 0.02). The relative risk of recurrence of infarction in persistent smokers was 4.4 times that in subjects who had stopped smoking. However, no significant difference was found between the mortality in the various subgroups. In addition to smoking, only two factors were found to significantly promote the onset of a fresh MI: an initial infarction with no Q wave (p = 0.007), and the persistence of spontaneous angina pectoris (p = 0.0009). | {
"pile_set_name": "PubMed Abstracts"
} |
Comparison of preservation solutions in an experimental model of organ cooling in kidney transplantation.
Viscous preservation solutions such as University of Wisconsin solution (UW) may be less effective at rapid removal of blood from an organ so that cooling takes longer. This study assessed the temperature changes of kidneys flushed with UW and hyperosmolar citrate (HOC). Porcine kidneys were retrieved and flushed with 500 ml UW or HOC at 4 degrees C while monitoring kidney temperature at depths of 5 and 20 mm. Renal function was measured on an isolated organ preservation system. The mean(s.d.) rate of temperature fall was slower with UW (at 20 mm: 0.64(0.11) versus 1.01(0.56) degrees C per min per 100 g; P = 0.016). The perfusion flow rate required to reduce the temperature to less than 10 degrees C at a depth of 20 mm was lower in the UW group (P = 0.002). Kidneys flushed with HOC gained more weight than those flushed with UW (mean(s.d.) 50(8) versus 7(13) per cent; P = 0.002). Flushing with UW was associated with less histological injury but there were no significant differences in renal function parameters between the groups. UW cooled kidneys more slowly than HOC, but with no adverse effect on renal function. UW resulted in less oedema and histological injury than HOC. | {
"pile_set_name": "PubMed Abstracts"
} |
Influenza and influenza-like illnesses in Poland in the epidemic season 2010/2011 according to the SENTINEL influenza surveillance system.
The aim of this study was to analyze data collected by the SENTINEL influenza surveillance system in Poland in the first post-pandemic season 2010/2011. The results include weeks 35/2010-17/2011. Physicians registered weekly number of influenza-like illnesses and collected specimens. Laboratory tests were done using PCR and/or real-time PCR or immunofluorescence. Laboratories also isolated the influenza virus. Influenza-like illness incidence amounted to 2802.7/100000. Weekly incidence ranged from 11.3/100000 to 232/100000. The most affected group was children 0-4 years. Influenza-like illness peak occurred between weeks 02/2011 and 11/2011. Influenza infections were confirmed in 34.9% of specimens. More cases were caused by influenza A, including A(H1N1)pdm09 than influenza B (59.9% vs. 40.1%). The isolated strains were similar to A/California/7/2009 or B/Brisbane/60/2008. Season 2010/2011 in Poland did not differ from the rest of Europe. Further improvement is necessary, especially in the area of specimen collection at the beginning of an epidemic season and carrying out the isolation of the influenza virus. | {
"pile_set_name": "PubMed Abstracts"
} |
PHOTOSYNTHETIC PIGMENT AND GENETIC DIFFERENCES BETWEEN TWO SOUTHERN OCEAN MORPHOTYPES OF EMILIANIA HUXLEYI (HAPTOPHYTA)1.
The widespread coccolithophorid Emiliania huxleyi (Lohmann) W. W. Hay et H. Mohler plays a pivotal role in the carbon pump and is known to exhibit significant morphological, genetic, and physiological diversity. In this study, we compared photosynthetic pigments and morphology of triplicate strains of Southern Ocean types A and B/C. The two morphotypes differed in width of coccolith distal shield elements (0.11-0.24 μm, type A; 0.06-0.12 μm, type B/C) and morphology of distal shield central area (grill of curved rods in type A; thin plain plate in type B/C) and showed differences in carotenoid composition. The mean 19'-hexanoyloxyfucoxanthin (Hex):chl a ratio in type B/C was >1, whereas the type A ratio was <1. The Hex:fucoxanthin (fuc) ratio for type B/C was 11 times greater than that for type A, and the proportion of fuc in type A was 6 times higher than that in type B/C. The fuc derivative 4-keto-19'-hexanoyloxyfucoxanthin (4-keto-hex) was present in type A but undetected in B/C. DNA sequencing of tufA distinguished morphotypes A, B/C (indistinguishable from B), and R, while little variation was observed within morphotypes. Thirty single nucleotide polymorphisms were identified in the 710 bp tufA sequence, of which 10 alleles were unique to B/C and B morphotypes, seven alleles were unique to type A, and six alleles were unique to type R. We propose that the morphologically, physiologically, and genetically distinct Southern Ocean type B/C sensu Young et al. (2003) be classified as E. huxleyi var. aurorae var. nov. S. S. Cook et Hallegr. | {
"pile_set_name": "PubMed Abstracts"
} |
Intra-hemispheric functional coupling of alpha rhythms is related to golfer's performance: a coherence EEG study.
It has been shown that frontocentral electroencephalographic (EEG) alpha rhythms (about 10-12 Hz) were higher in amplitude in expert golfers in successful than unsuccessful putts, possibly reflecting the idea that amplitude regulation of frontocentral alpha rhythms is a physiological mechanism implied in motor control and golfer's performance (Babiloni et al., 2008). Here, we tested the ancillary hypothesis that golfer's performance is also associated to an improved coordination of cortical activity, as reflected by functional coupling of alpha rhythms across cortical regions. To this aim, between-electrodes spectral coherence was computed from spatially enhanced EEG data of the mentioned study (i.e. right handed 12 expert golfers; augmented 10-20 system; surface Laplacian estimation). Low- (about 8-10 Hz) and high-frequency (about 10-12 Hz) alpha sub-bands were considered with reference to individual alpha frequency peak. Statistical results showed that intra-hemispheric low-frequency alpha coherence in bilateral parietal-frontal (P3-F3 and P4-F4 electrodes) and parietal-central (P3-C3 and P4-C4 electrodes) was higher in amplitude in successful than unsuccessful putts (p<0.004). The same was true for intra-hemispheric high-frequency alpha coherence in bilateral parietal-frontal regions (p<0.004). These findings suggest that intra-hemispheric functional coupling of cortical alpha rhythms between "visuo-spatial" parietal area and other cortical areas is implicated in fine motor control of golfer's performance. | {
"pile_set_name": "PubMed Abstracts"
} |
Coconut Products Improve Signs of Diet-Induced Metabolic Syndrome in Rats.
Increasing prevalence of obesity and metabolic syndrome warrants identification of potential therapeutic options for intervention. This study tested commercially available Virgin Coconut Oil and Coconut Nourish, as coconuts are rich sources of lauric and myristic acids. Male Wistar rats were fed either corn starch diet (C); high-carbohydrate, high-fat diet (H); high-carbohydrate, high-virgin coconut oil diet (HV); or high-carbohydrate, high-coconut Nourish diet (HN) for 16 weeks. Metabolic, liver, and cardiovascular health parameters were measured during and at the end of the study. Virgin coconut oil lowered body weight (C 386±8g, H 516±13g, HV 459±10g), blood glucose concentrations (C 4.2±0.1 mmol/L, H 5.4±0.2 mmol/L, HV 4.6±0.2 mmol/L), systolic blood pressure (C 127±5mmHg, H 149±4mmHg, HV 133±3mmHg,) and diastolic stiffness (C 25.0±1.7, H 31.4±1.2, HV 25.2±2.3,) with improved structure and function of the heart and liver. Coconut Nourish increased total body lean mass (C 255±10g, H 270±16g, HN 303±15g) and lowered plasma total cholesterol concentrations (C 1.6±0.2 mmol/L, H 1.7±0.1 mmol/L, HN 1.0±0.0 mmol/L), systolic blood pressure (C 127±5mmHg, H 149±4mmHg, HN 130±3mmHg) and diastolic stiffness (C 25.0±1.7, H 31.4±1.2, HN 26.5±1.0), improved structure and function of the heart and liver but increased plasma concentrations of triglycerides (C 0.3±0.1 mmol/L, H 1.1±0.4 mmol/L, HN 1.8±0.2 mmol/L) and non-esterified fatty acids (C 1.2±0.3 mmol/L, H 3.3±0.8 mmol/L, HN 5.6±0.4 mmol/L). Thus, the fiber and protein in coconut Nourish and the medium-chain saturated fatty acids in virgin coconut oil may improve cardiovascular and liver complications in obesity. | {
"pile_set_name": "PubMed Abstracts"
} |
Antiviral effects on mouse leukemia virus replication by oligodeoxynucleotides in vitro and in vivo.
Oligodeoxynucleotides (Oligomers) including modified and unmodified, homo- and heterooligomers were tested for their ability to inhibit mouse SRS leukemia virus (SRSV)-induced proliferation of cells, colony formation, syncytium formation and reverse transcriptase (RT) activity in vitro. Phosphorothioate analogs complementary to Mo-MuLV sequences, as well as noncomplementary homooligomers, were found to be active. Unmodified homooligomer (dC14) also showed inhibition of growth of ascitic lymphoma carrying SRS virus. Our study suggests that different classes of oligonucleotides may inhibit SRSV replication with different mechanisms. | {
"pile_set_name": "PubMed Abstracts"
} |
Uptake of the trypanocidal drug suramin by bloodstream forms of Trypanosoma brucei and its effect on respiration and growth rate in vivo.
After a single intravenous injection of suramin the rate of removal of the drug from the plasma into other tissue compartments of the rat is independent of initial concentration. The data can be fitted to the sum of two exponential functions, consistent with a two-compartment, open model system. Trypanosomes take up only small amounts of suramin in vivo and do not actively concentrate the drug within the cell. Uptake is apparently by a non-saturable process that decreases with time and is dependent on the amount of suramin already taken up. Once within the cell, suramin progressively inhibits respiration and glycolysis, such that, for a given exposure in vivo, inhibition of oxygen consumption is proportional to the total amount of suramin absorbed. It can be calculated that only a fraction (4--9%) of this total is required to inhibit respiration to the extent found in broken cell preparations. The combined inhibition of two key enzymes in glycolysis--the sn-glycerol-3-phosphate oxidase (EC unassigned) and the glycerol-3-phosphate dehydrogenase (NAD+) (sn-glycerol-3-phosphate: NAD+ 2-oxidoreductase, EC 1.1.1.8)--are sufficient to account for the differential inhibition of glucose and oxygen consumption and of pyruvate production, together with the small, but significant, production of glycerol. Even at the highest dose of suramin tolerated by the rat, trypanosomes continue to increase exponentially in the bloodstream for at least 6 h. The mean doubling time is increased from 4.6 h to a maximum of about 12.5 h in rats treated with doses of suramin in the range 25--150 mg/kg. In the light of these and other findings, it is concluded that part of the trypanocidal action of suramin results from the inhibition of ATP production by glycolysis. | {
"pile_set_name": "PubMed Abstracts"
} |
Microarray based IgE detection in poly-sensitized allergic patients with suspected food allergy - an approach in four clinical cases.
Component-resolved diagnosis and microarray technology have been recently introduced into clinical allergy practice, and may be particularly useful in poly-sensitized allergic patients. We compare the clinical usefulness of a microarray-based IgE detection assay (ISAC(®)) with skin tests and specific IgE with standard allergens (sIgE) or their monocomponents in four case reports of patients poly-sensitized to aeroallergens and food. Case 1: a woman with rhinitis, oral allergy syndrome to several fruits and anaphylaxis to cherry. Diagnostic tests supported non-specific lipid transfer proteins (nsLTPs) primary sensitization. Case 2: a woman with exercise-induced asthma, rhino-conjunctivitis and oral allergy syndrome to fresh fruits of different families. A diagnosis of primary grass and weed pollen allergy with profilin and pathogenesis-related protein family 10 (PR-10) cross-reactive food allergy was proposed. Case 3: a man with atopic eczema, asthma, rhinitis, and multiple anaphylactic episodes with cashew nuts and oral allergy syndrome to fruits. The diagnostic workup supported a primary birch pollen allergy with PR-10 and nsLTPs cross-reactive food allergy. Case 4: a woman with rhino-conjunctivitis, per-operative anaphylaxis due to latex and recent pharyngeal angio-oedema episodes. The diagnosis was a primary grass and weed pollen allergy with equivocal profilin sensitization and no obvious cross-reactivity mediated by nsLTPs sensitization. The possibility to carry out multiple sIgE measurements with single protein allergens, in particular with the microarray technique, is a useful, simple and non-invasive diagnostic tool in complex poly-sensitized allergic patients. | {
"pile_set_name": "PubMed Abstracts"
} |
Looking BAC at striatal signaling: cell-specific analysis in new transgenic mice.
Understanding how molecular signaling pathways participate in behavioral responses requires determining precisely in which neuronal populations they are activated. The recent development of bacterial artificial chromosome (BAC) transgenic mice expressing a variety of reporters, epitope tagged-proteins or Cre recombinase driven by specific promoters, is a significant step forward in this direction. These mice help overcome the limitations of traditional approaches that examine an average of signaling events occurring in mixed populations of cells. Here, we review how recent studies using such tools have revisited the regulation of striatal signaling pathways, demonstrating the striking segregation between neurons expressing dopamine D1 and D2 receptors and significantly extending our overall knowledge of striatal neurons. Thus, BAC transgenic mice are changing the way to conceive experiments and provide an opportunity to fill the gaps between molecular and systems neurosciences. | {
"pile_set_name": "PubMed Abstracts"
} |
The effect of the CS-UCS interval and extinction on place conditioning and analgesic tolerance with morphine.
In experiment 1, a CS-UCS interval study of place conditioning and analgesic tolerance with morphine was conducted. Morphine (10 mg/kg i.p.) was administered to separate groups of rats either 2 h prior to, 1 h prior to, immediately prior to, immediately after or 2 h after 30-min confinement in one end compartment of a place conditioning apparatus. A total of three choice tests was given, one after every six morphine injections. A preference for the end compartment contingent upon morphine injection was shown in groups that received morphine prior to end compartment placement. Groups that received morphine after end compartment placement were not different in their preference behavior from groups that received only saline during place conditioning training. A hot-plate test for tolerance to the analgesic effect of morphine was given at the end of all choice testing. All groups that had received morphine during place conditioning training were equally tolerant. These results indicate a dissociation between the analgesic effect of morphine and the effect that produces place preference, since the former was not affected by temporal parameters that did affect the latter. In the second experiment, the effect of extinction on a morphine-induced place preference was studied using extinction procedures that, in contrast to previous studies, equated exposure to both end compartments. Whereas the morphine-induced place preference was undiminished by a 10-day retention period in which animals received saline injections in the home cage, extinction trials during the same period eliminated the place preference. These results provide evidence that morphine-induced place preferences involve associative processes. | {
"pile_set_name": "PubMed Abstracts"
} |
Mid-term outcomes of the modified Cox-maze procedure for elderly patients: a risk analysis for failure.
Although the maze procedure is highly effective for most patients with atrial fibrillation (AF), its standardized application to elderly patients is controversial. Between 2004 and 2007, 143 patients with a mean age of 65 years of age or older underwent the modified Cox-maze procedure concomitant with other cardiac procedures. The follow-up data were available from 128 patients, and the mean follow-up period was 37.1 months. The overall sinus rhythm (SR) rate at the latest follow-up was 74.2%. The cumulative freedom from AF without antiarrhythmic medication was 65.2% at five years. Stroke was less prevalent in patients with a stable SR than in those with a recurrence of AF. There were two patients (1.6%) who required permanent pacemaker placement during follow-up. Multivariate analysis demonstrated that a duration of AF >5 years, a fine f-wave and a dimension of the left atrium ≥60 mm were independent risk factors for recurrent AF. The Cox proportional hazard model showed that the former two factors independently affected freedom from recurrence. In conclusion, the modified Cox-maze procedure was safe and beneficial for patients 65 years of age or older, supporting that the limited biatrial ablation might be sufficient for elderly patients without risk factors for recurrence. | {
"pile_set_name": "PubMed Abstracts"
} |
Anti-tumor ribonuclease, combined with or conjugated to monoclonal antibody MRK16, overcomes multidrug resistance to vincristine in vitro and in vivo.
Onconase, a ribonuclease isolated from Rana pipiens oocytes and early embryos, is a member of the RNase A superfamily. Onconase has anti-neoplastic properties both in vitro and in vivo, and is undergoing clinical evaluation. In the present study, Onconase was combined with or conjugated to MRK16, an anti-P-glycoprotein (Pgp) monoclonal antibody. The interaction of these combinations with vincristine (VCR) against parental and multidrug resistant (MDR), Pgp expressing, human colon carcinoma cells caused increased VCR cytotoxicity in vitro and enhanced survival of athymic nude mice given transplants of drug resistant HT-29(mdr1) cells in vivo. The results suggest that combination treatment with Onconase and other agents that modulate the chemosensitivity of Pgp-expressing human tumor cells has the potential to overcome MDR. | {
"pile_set_name": "PubMed Abstracts"
} |
Effects of cerivastatin sodium, a new HMG-CoA reductase inhibitor, on biliary lipid metabolism in patients with hypercholesterolemia.
The use of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors has become common in the treatment of hypercholesterolemia. The present uncontrolled study was undertaken to determine the effect of cerivastatin sodium (BAY w 6228), a new HMG-CoA reductase inhibitor, on biliary lipid levels in patients with hypercholesterolemia. Twenty-one hypercholesterolemic patients (World Health Organization type IIa = 16 patients; type IIb = 5 patients) received placebo during a 4- to 6-week observation period, after which they received cerivastatin sodium 0.2 mg/d for 12 weeks. Fasting blood samples were drawn for the measurement of serum lipid levels early in the morning before the start of treatment and once a month for each of the 12 weeks of cerivastatin sodium treatment. Gallbladder bile samples were aspirated with a duodenal tube by cerulein stimulation to assess bile lithogenicity. Serum total cholesterol levels decreased markedly after 12 weeks. However, no significant difference was found in the molar percentage composition of biliary lipids (e.g., cholesterol, phospholipids, and total bile acids) or in individual biliary bile acids. Consequently, no significant change in bile cholesterol saturation index was found. The index values before and after 12 weeks of treatment were 0.81 +/- 0.38 and 0.80 +/- 0.47, respectively, whereas when patients were grouped by type of hypercholesterolemia, there was a tendency toward decreased lithogenicity in patients with type IIb but not type IIa hypercholesterolemia. We concluded that cerivastatin sodium was an effective cholesterol-lowering drug that did not appear to worsen biliary lipid metabolism and that may decrease lithogenicity in patients with type IIb hypercholesterolemia. | {
"pile_set_name": "PubMed Abstracts"
} |
Virus-host interactions in hepatitis C virus infection: implications for molecular pathogenesis and antiviral strategies.
With a global burden of 170 million chronically infected patients and a major cause of liver cirrhosis and hepatocellular carcinoma, hepatitis C virus (HCV) is a major public health challenge. Recent discoveries of viral and cellular factors mediating virus-host interactions have allowed scientists to uncover the key molecular mechanisms of viral infection and escape from innate and adaptive immune responses. These include the discovery of tight junction proteins as entry factors and microRNA-122, cyclophilins and lipoproteins as host factors for virus translation, replication and production. Furthermore, global genetic analyses have identified IL-28B as a genetic factor associated with the outcome of HCV infection. These discoveries markedly advance the understanding of the molecular pathogenesis of HCV infection and uncover novel targets for urgently needed antiviral strategies. | {
"pile_set_name": "PubMed Abstracts"
} |
Adapted head- and eye-movement responses to added-head inertia.
Adaptation to inertia added to the head was studied in man by mounting masses on a rigidly attached helmet. Two- to ten-fold increases of inertia were thus produced, while an overhead suspension compensated for the weights. Eye and head positions and corresponding velocities were simultaneously recorded during eye-head tracking of a target stepping at 0.2 Hz in the horizontal direction. Without added inertia, fast gaze movements are type III, the accelerated head movement coming early and the resulting VOR truncating the simultaneous eye movement saccade in both amplitude and velocity. Head oscillations are fast and overcompensated by higher gain VOR. With added inertia, the adapted head movement is slowed and delayed. This permits the eye movement saccade to be completed before head movement begins and to escape truncation; the saccade is normal or slightly increased in amplitude. Head oscillations are slow and compensated by normal gain VOR. Either truncation of the saccade or overcompensation of the VOR leads to eye movement and gaze position error that is corrected for by secondary corrective saccades. These same two errors in gaze coordination could explain the cause of the perceived oscillopsia. Oscillopsia, or continual displacement or instability of the visual worlds, is a symptom of breakdown of space constancy, and was prominent and consistent in perceptual reports of our subjects. Adaptation resulting from adding inertia to the head occurred much faster than that induced by adding prisms or lenses.(ABSTRACT TRUNCATED AT 250 WORDS) | {
"pile_set_name": "PubMed Abstracts"
} |
Peripheral non-small cell lung cancers 2.0 cm or less in diameter: proposed criteria for limited pulmonary resection based upon clinicopathological presentation.
Clinical features of peripheral non-small cell lung cancer 2.0 cm or less were retrospectively analyzed. Nodal status and prognosis in relation to tumor diameter and histologic type were investigated in 171 consecutive patients with peripheral clinical T1N0M0 non-small cell lung carcinomas 2 cm or less in diameter and who had undergone surgical resection between 1976 and 1997. Of the 171 patients, 136 had adenocarcinoma, 27 had squamous cell carcinoma, four had large cell carcinoma, three had carcinoid and one had adeno-squamous carcinoma. There was no statistically significant difference in the incidence of stage I cases between adenocarcinoma and squamous cell carcinoma. Lymph node involvement was recognized in 30 (17.5%) patients: ten (5.8%) at N1 nodes and 20 (11.7%) at N2 nodes. Lymph node metastasis was significantly more common in tumors 1.5-2.0 cm in diameter (22%) than in those 1.5 cm or less in diameter (14.0%, P = 0.0490). There was no lymph node metastasis in tumors 1.0 cm or less in diameter. The 5-year survival rates cases with or without lymph node involvement were 63.3 and 75.3%, respectively, showing significant difference (P = 0.0338). The result of the present study suggested that systematic mediastinal and hilar lymph node dissection is necessary even for cases with tumor diameter less than 2 cm. However, if the tumor is within 1.0 cm in diameter, mediastinal lymph node dissection might be dispensable; therefore, these cases are good candidates for video-assisted lobectomy. | {
"pile_set_name": "PubMed Abstracts"
} |
Indoor air pollution by different heating systems: coal burning, open fireplace and central heating.
Investigations of indoor air pollution by different heating systems in private homes are described. Sixteen homes, 7 with coal burning, 1 with open fireplace (wood burning) and 8 with central heating have been investigated. We measured the concentrations of carbon monoxide, carbon dioxide and sedimented dust in indoor air, of total suspended particulates, heavy metals and of polycyclic aromatic hydrocarbons in indoor and outdoor air. Measurements were taken during winter (heating period) and during summer (non-heating period). Generally, we found higher indoor air pollution in homes with coal burning and open fireplace than in homes with central heating. Especially, the concentrations of carbon monoxide, sedimented dust and of some heavy metals were higher. In one case, we found also high indoor air pollution in a home with central heating. This apartment is on the ground floor of a block of flats, and the central heating system in the basement showed a malfunctioning of the exhaust system. | {
"pile_set_name": "PubMed Abstracts"
} |
A neurochemical characterisation of the golden hamster myenteric plexus.
The neurochemical composition of nerve fibres and cell bodies in the myenteric plexus of the proventriculus, stomach and small and large intestines of the golden hamster was investigated by using immunohistochemical and histochemical techniques. In addition, the procedures for localising nitric-oxide-utilising neurones by histochemical (NADPH-diaphorase) and immunohistochemical (nitric oxide synthase) methods were compared. The co-localisation of vasoactive intestinal polypeptide and nitric oxide synthase in the myenteric plexus of all regions of the gut was also assessed. The results demonstrated the presence of nerve fibres and nerve cell bodies immunoreactive to protein gene product, vasoactive intestinal polypeptide, substance P, calcitonin gene-related peptide, tyrosine hydroxylase, 5-hydroxytryptamine and nitric oxide synthase in all regions of the gastrointestinal tract examined. The pattern of distribution of immunoreactive nerve fibres and nerve cell bodies containing the above markers was found to vary in different regions of the gut. Myenteric neurones and nerve fibres containing immunoreactivity to nitric oxide synthase and NADPH-diaphorase reactivity, however, were shown to have an identical distribution throughout the gut. In contrast to some studies on the guinea-pig and rat, the co-existence of vasoactive intestinal polypeptide and nitric oxide synthase was seen in only a small population of myenteric neurones. | {
"pile_set_name": "PubMed Abstracts"
} |
1H solid-state nuclear magnetic resonance study of the mobility of the tetrapropylammonium template in a purely siliceous MFI-type zeolite.
Dynamics of tetrapropylammonium (TPA) cation occluded during the synthesis in a siliceous MFI zeolite is investigated by 1H broad-line nuclear magnetic resonance (NMR) methods. Second moments M2, spin-lattice relaxation times T1 and T1 rho are measured in a large temperature domain. To al comparison, similar measurements are also reported in bulk tetrapropylammonium bromide (TPABr). Whereas methyl reorientation at low temperature and tumbling of the cation in the plastic phase are observed in crystalline TPABr in accordance with published studies, a new slower motion which could not be identified is observed below the phase transition. Such a motion is much more clearly shown by the existence of a minimum of T1 rho in a quenched sample. Our measurements in the zeolite demonstrate that the TPA template exhibits a larger and more complex mobility below 378 K. Beyond the fast methyl reorientation, the results disclose a motion which probably involves the entire propyl arms inside the channels. So the zeolite framework seems to make such a kind of motion easier. On the contrary, even at 450 K, the highest temperature investigated, the tumbling which would necessitate exchange of the propyl arms between the channels is not observed. A slow motion, responsible for a decrease of T1 rho above 350 K, could not be identified. While a simple correlation time is sufficient to describe the relaxation time dependences in TPABr, a distribution (such as Williams-Watts) is required to account for those in the zeolite. | {
"pile_set_name": "PubMed Abstracts"
} |
Porphyria cutanea tarda in south-east New South Wales.
Thirteen patients with porphyria cutanea tarda diagnosed between 1994 and 2000 were reviewed to evaluate the precipitating factors and associations of porphyria cutanea tarda in a regional area of coastal and rural NSW. The majority had more than one precipitating factor, with excess alcohol intake, mutations in the haemochromatosis gene, chronic hepatitis C infection and oestrogen therapy being the most common. Antibodies to the hepatitis C virus were detected in 25% and these patients presented at a younger age. Of the patients tested for the two known haemochromatosis gene mutations, six (46%) had at least one copy of the C282Y mutation. Two (15%) patients were homozygous for the C282Y mutation and two (15%) were compound heterozygous for the C282Y and H63D mutations. All patients responded to venesection, which is the treatment of choice for the majority of patients with porphyria cutanea tarda. | {
"pile_set_name": "PubMed Abstracts"
} |
Fight fire with fire: the effect of perceived anger on punitive intuitions.
The human ability to "mind-read" is fundamental in social interaction (e.g., contributing to the experience of empathy). The present research tests the hypothesis that perceiving anger in others on the basis of facial cues is sufficient to elicit very rapid punitive responses toward crime. The results suggest that individuals are faster to harshly punish criminals who appear to be angry, and that this effect emerges early in the decision-making process. Black criminals receive quicker punitive responses, but the effect of ethnicity is weakened at high levels of perceived anger. The results are discussed in terms of associative processes linking anger to punishment, the human ability to simulate and experience others' emotional responses, and the role of anger in eliciting hostile aggression. The findings also have important policy implications, as they suggest that drumming up anger toward crime could engender punitive intuitions. | {
"pile_set_name": "PubMed Abstracts"
} |
Subchondral cysts create increased intra-osseous stress in early knee OA: A finite element analysis using simulated lesions.
To investigate the role of intra-osseous lesions in advancing the pathogenesis of Osteoarthritis (OA) of the knee, using Finite Element Modeling (FEM) in conjunction with high-resolution imaging techniques. Twenty early stage OA patients (≤ Grade 2 radiographic score) were scanned with a prototype, cone-beam CT system. Scans encompassed the mid-shaft of the femur to the diaphysis of the proximal tibia. Individual bones were segmented to create 3D geometric models that were transferred to FE software for loading experiments. Patient-specific, inhomogeneous material properties were derived from the CT images and mapped directly to the FE models. Duplicate models were also created, with a 3D sphere (range 3-12 mm) introduced into a weight-bearing region of the joint, mimicking the size, location, and composition of a subchondral bone cyst (SBC). A spherical shell extending 1mm radially around the SBC served as the sample volume for measurements of von Mises equivalent stress. Both models were vertically loaded with 750 N, or approximately 1 body weight during a single-leg stance. All FE models exhibited a physiologically realistic weight-bearing distribution of stress, which initiated at the joint surface and extended to the cortical bone. Models that contained the SBC experienced a nearly two-fold increase in stress (0.934 ± 0.073 and 1.69 ± 0.159 MPa, for the non-SBC and SBC models, respectively) within the bone adjacent to the SBC. In addition, there was a positive correlation found between the diameter of the SBC and the resultant intra-osseous stress under load (p = 0.004). Our results provide insights into the mechanism by which SBC may accelerate OA, leading to greater pain and disability. Based on these findings, we feel that patient-derived FE models of the OA knee - utilizing in vivo imaging data - present a tremendous potential for monitoring joint mechanics under physiological loads. | {
"pile_set_name": "PubMed Abstracts"
} |
Comparison of galactomannan, beta-D-glucan, and Aspergillus DNA in sera of high-risk adult patients with hematological malignancies for the diagnosis of invasive aspergillosis.
Invasive aspergillosis (IA) is a fatal infection that is difficult to diagnose in immunocompromised patients. In this study, Aspergillus-specific DNA was searched using real-time PCR (RT-PCR) in serum samples. Galactomannan (GM) and/or beta-D-glucan (BDG) tests were previously performed on these samples for 70 neutropenic patients with hematological malignancy. The patients were categorized according to the criteria of the European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG). Among the patient serum samples, the first positive GM or BDG test sample and the median sample of GM or BDG test for negative patients were used to detect DNA levels by RT-PCR method (Light Cycler 480, Roche Molecular Biochemicals, Meylan, France) using a commercial kit (Way2Gene Fungi; Genmar, İzmir, Turkey). When the proven and probable IA group were considered as real patients, sensitivity of Aspergillus-specific DNA test was 90%, specificity was 73.3%, positive predictive value was 81.8%, and negative predictive value was 84.6%. This study found that searching for specific DNA by RT-PCR method has a sensitivity as high as the GM test. Although specificity was rather low, it was concluded that it can be used jointly with GM and BDG tests after decreasing contamination by severe laboratory applications. | {
"pile_set_name": "PubMed Abstracts"
} |
Filtration and transport of Bacillus subtilis spores and the F-RNA phage MS2 in a coarse alluvial gravel aquifer: implications in the estimation of setback distances.
Filtration of Bacillus subtilis spores and the F-RNA phage MS2 (MS2) on a field scale in a coarse alluvial gravel aquifer was evaluated from the authors' previously published data. An advection-dispersion model that is coupled with first-order attachment kinetics was used in this study to interpret microbial concentration vs. time breakthrough curves (BTC) at sampling wells. Based on attachment rates (katt) that were determined by applying the model to the breakthrough data, filter factors (f) were calculated and compared with f values estimated from the slopes of log (cmax/co) vs. distance plots. These two independent approaches resulted in nearly identical filter factors, suggesting that both approaches are useful in determining reductions in microbial concentrations over transport distance. Applying the graphic approach to analyse spatial data, we have also estimated the f values for different aquifers using information provided by some other published field studies. The results show that values of f, in units of log (cmax/co) m(-1), are consistently in the order of 10(-2) for clean coarse gravel aquifers, 10(-3) for contaminated coarse gravel aquifers, and generally 10(-1) for sandy fine gravel aquifers and river and coastal sand aquifers. For each aquifer category, the f values for bacteriophages and bacteria are in the same order-of-magnitude. The f values estimated in this study indicate that for every one-log reduction in microbial concentration in groundwater, it requires a few tens of meters of travel in clean coarse gravel aquifers, but a few hundreds of meters in contaminated coarse gravel aquifers. In contrast, a one-log reduction generally only requires a few meters of travel in sandy fine gravel aquifers and sand aquifers. Considering the highest concentration in human effluent is in the order of 10(4) pfu/l for enteroviruses and 10(6) cfu/100 ml for faecal coliform bacteria, a 7-log reduction in microbial concentration would comply with the drinking water standards for the downgradient wells under natural gradient conditions. Based on the results of this study, a 7-log reduction would require 125-280 m travel in clean coarse gravel aquifers, 1.7-3.9 km travel in contaminated coarse gravel aquifers, 33-61 m travel in clean sandy fine gravel aquifers, 33-129 m travel in contaminated sandy fine gravel aquifers, and 37-44 m travel in contaminated river and coastal sand aquifers. These recommended setback distances are for a worst-case scenario, assuming direct discharge of raw effluent into the saturated zone of an aquifer. Filtration theory was applied to calculate collision efficiency (alpha) from model-derived attachment rates (katt), and the results are compared with those reported in the literature. The calculated alpha values vary by two orders-of-magnitude, depending on whether collision efficiency is estimated from the effective particle size (d10) or the mean particle size (d50). Collision efficiency values for MS-2 are similar to those previously reported in the literature (e.g. ) [DeBorde, D.C., Woessner, W.W., Kiley, QT., Ball, P., 1999. Rapid transport of viruses in a floodplain aquifer. Water Res. 33 (10), 2229-2238]. However, the collision efficiency values calculated for Bacillus subtilis spores were unrealistic, suggesting that filtration theory is not appropriate for theoretically estimating filtration capacity for poorly sorted coarse gravel aquifer media. This is not surprising, as filtration theory was developed for uniform sand filters and does not consider particle size distribution. Thus, we do not recommend the use of filtration theory to estimate the filter factor or setback distances. Either of the methods applied in this work (BTC or concentration vs. distance analyses), which takes into account aquifer heterogeneities and site-specific conditions, appear to be most useful in determining filter factors and setback distances. | {
"pile_set_name": "PubMed Abstracts"
} |
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