Structure of the type IV secretion system in different strains of Anaplasma phagocytophilum.
Anaplasma phagocytophilum is an intracellular organism in the Order Rickettsiales that infects diverse animal species and is causing an emerging disease in humans, dogs and horses. Different strains have very different cell tropisms and virulence. For example, in the U.S., strains have been described that infect ruminants but not dogs or rodents. An intriguing question is how the strains of A. phagocytophilum differ and what different genome loci are involved in cell tropisms and/or virulence. Type IV secretion systems (T4SS) are responsible for translocation of substrates across the cell membrane by mechanisms that require contact with the recipient cell. They are especially important in organisms such as the Rickettsiales which require T4SS to aid colonization and survival within both mammalian and tick vector cells. We determined the structure of the T4SS in 7 strains from the U.S. and Europe and revised the sequence of the repetitive virB6 locus of the human HZ strain. Although in all strains the T4SS conforms to the previously described split loci for vir genes, there is great diversity within these loci among strains. This is particularly evident in the virB2 and virB6 which are postulated to encode the secretion channel and proteins exposed on the bacterial surface. VirB6-4 has an unusual highly repetitive structure and can have a molecular weight greater than 500,000. For many of the virs, phylogenetic trees position A. phagocytophilum strains infecting ruminants in the U.S. and Europe distant from strains infecting humans and dogs in the U.S. Our study reveals evidence of gene duplication and considerable diversity of T4SS components in strains infecting different animals. The diversity in virB2 is in both the total number of copies, which varied from 8 to 15 in the herein characterized strains, and in the sequence of each copy. The diversity in virB6 is in the sequence of each of the 4 copies in the single locus and the presence of varying numbers of repetitive units in virB6-3 and virB6-4. These data suggest that the T4SS should be investigated further for a potential role in strain virulence of A. phagocytophilum.


Post-graduation migration intentions of students of Lebanese medical schools: a survey study.
The international migration of physicians is a global public health problem. Lebanon is a source country with the highest emigration factor in the Middle East and North Africa and the 7th highest in the World. Given that residency training abroad is a critical step in the migration of physicians, the objective of this study was to survey students of Lebanese medical schools about their intentions to train abroad and their post training plans. Our target population consisted of all students of Lebanese medical schools in the pre-final and final years of medical school. We developed the survey questionnaire based on the results of a qualitative study assessing the intentions and motives for students of Lebanese medical schools to train abroad. The questionnaire inquired about student's demographic and educational characteristics, intention to train abroad, the chosen country of abroad training, and post-training intention of returning to Lebanon. Of 576 eligible students, 425 participated (73.8% response rate). 406 (95.5%) respondents intended to travel abroad either for specialty training (330 (77.6%)) or subspecialty training (76 (17.9%)). Intention to train abroad was associated with being single compared with being married. The top 4 destination countries were the US (301(74.1%)), France (49 (12.1%)), the United Kingdom (31 (7.6%)) and Canada (17 (4.2%)). One hundred and two (25.1%) respondents intended to return to Lebanon directly after finishing training abroad; 259 (63.8%) intended to return to Lebanon after working abroad temporarily for a varying number or years; 43 (10.6%) intended to never return to Lebanon. The intention to stay indefinitely abroad was associated male sex and having a 2nd citizenship. It was inversely associated with being a student of one of the French affiliated medical schools and a plan to train in a surgical specialty. An alarming percentage of students of Lebanese medical schools intend to migrate for post graduate training, mainly to the US. A minority intends to return directly to Lebanon after finishing training abroad.


Commentary: sex difference differences? A reply to Constantino.
Messinger et al. found a 3.18 odds ratio of male to female ASD recurrence in 1241 prospectively followed high-risk (HR) siblings. Among high-risk siblings (with and without ASD), as well as among 583 low-risk controls, girls exhibited higher performance on the Mullen Scales of Early Learning, as well as lower restricted and repetitive behavior severity scores on the Autism Diagnostic Observation Schedule (ADOS) than boys. That is, female-favoring sex differences in developmental performance and autism traits were evident among low-risk and non-ASD high-risk children, as well as those with ASD. Constantino (Mol Autism) suggests that sex differences in categorical ASD outcomes in Messinger et al. should be understood as a female protective effect. We are receptive to Constantino's (Mol Autism) suggestion, and propose that quantitative sex differences in autism-related features are keys to understanding this female protective effect.


APE1- and APE2-dependent DNA breaks in immunoglobulin class switch recombination.
Antibody class switch recombination (CSR) occurs by an intrachromosomal deletion requiring generation of double-stranded breaks (DSBs) in switch-region DNA. The initial steps in DSB formation have been elucidated, involving cytosine deamination by activation-induced cytidine deaminase and generation of abasic sites by uracil DNA glycosylase. However, it is not known how abasic sites are converted into single-stranded breaks and, subsequently, DSBs. Apurinic/apyrimidinic endonuclease (APE) efficiently nicks DNA at abasic sites, but it is unknown whether APE participates in CSR. We address the roles of the two major mammalian APEs, APE1 and APE2, in CSR. APE1 deficiency causes embryonic lethality in mice; we therefore examined CSR and DSBs in mice deficient in APE2 and haploinsufficient for APE1. We show that both APE1 and APE2 function in CSR, resulting in the DSBs necessary for CSR and thereby describing a novel in vivo function for APE2.


Intestinal CaBP: a new quantitive index of vitamin D deficiency in the rat.
Rats raised from weaning on regiments adequate in calcium and phosphorus but deficient in vitamin D will have no detectable intestinal calcium-binding proteins (CaBP), whether or not they show other signs of vitamin D deficiency, such as hypocalcemia. When hypocalcemic, vitamin D-deficient animals were treated with 25-hydroxycholecalciferol, a vitamin D metabolite, they showed a dose-dependent increase in plasma calcium and CaBP; both responses can be described by a single linear relationship, which appears to apply whether the metabolite is 25-hydroxycholecalciferol or dihydrotachysterol. Since vitamin D status is only one determinant of plasma calcium, whereas CaBP (or its expression) appears to depend on vitamin D quantitatively, CaBP may be used as an index of vitamin D status, provided calcium intake is controlled.


All-Trans Retinoic Acid-Induced Deficiency of the Wnt/β-Catenin Pathway Enhances Hepatic Carcinoma Stem Cell Differentiation.
Retinoic acid (RA) is an important biological signal that directly differentiates cells during embryonic development and tumorigenesis. However, the molecular mechanism of RA-mediated differentiation in hepatic cancer stem cells (hCSCs) is not well understood. In this study, we found that mRNA expressions of RA-biosynthesis-related dehydrogenases were highly expressed in hepatocellular carcinoma. All-trans retinoic acid (ATRA) differentiated hCSCs through inhibiting the function of β-catenin in vitro. ATRA also inhibited the function of PI3K-AKT and enhanced GSK-3β-dependent degradation of phosphorylated β-catenin. Furthermore, ATRA and β-catenin silencing both increased hCSC sensitivity to docetaxel treatment. Our results suggest that targeting β-catenin will provide extra benefits for ATRA-mediated treatment of hepatic cancer patients.


Screening SMAD1, SMAD2, SMAD3, and SMAD5 for germline mutations in juvenile polyposis syndrome.
Juvenile polyps occur in several Mendelian disorders, whether in association with gastrointestinal cancer alone (juvenile polyposis syndrome, JPS) or as part of known syndromes (Cowden, Gorlin, and Bannayan-Zonana) in association with developmental abnormalities, dysmorphic features, or extraintestinal tumours. Recently, some JPS families were shown to harbour germline mutations in the SMAD4 (DPC4) gene, providing further evidence for the importance of the TGFbeta signalling pathway in colorectal cancer. There remains, however, considerable, unexplained genetic heterogeneity in JPS. Other members of the SMAD family are excellent candidates for JPS, especially SMAD2 (which, like SMAD4, is mutated somatically in colorectal cancers), SMAD3 (which causes colorectal cancer when "knocked out" in mice), SMAD5, and SMAD1. SMAD1, SMAD2, SMAD3, and SMAD5 were screened for germline mutations in 30 patients with JPS and without SMAD4 mutations. No mutations were found in any of these genes. A G-A C89Y polymorphism with possible effects on protein function was found in SMAD3, but the frequencies of the G and A alleles did not differ between patients with JPS and controls. It remains to be determined whether or not this polymorphism is involved in a minor predisposition to colorectal or other carcinomas. SMAD4 may be the only member of the SMAD family which causes JPS when mutant in the germline. The other genes underlying JPS remain to be identified.


Expression and clinical significance of glucose regulated proteins GRP78 (BiP) and GRP94 (GP96) in human adenocarcinomas of the esophagus.
Glucose regulated proteins (GRPs) are main regulators of cellular homeostasis due to their role as molecular chaperones. Moreover, the functions of GRPs suggest that they also may play important roles in cancer biology. In this study we investigated the glucose regulated proteins GRP78 (BiP) and GRP94 (GP96) in a series of human esophageal adenocarcinomas to determine their implications in cancer progression and prognosis. Formalin-fixed, paraffin-embedded tissues of primary resected esophageal (Barrett) adenocarcinomas (n = 137) and corresponding normal tissue were investigated. mRNA-gene expression levels of GRP78 and GRP94 were determined by quantitative real-time RT-PCR after mRNA extraction. Protein expression analysis was performed with immunohistochemical staining of the cases, assembled on a tissue micorarray. The results were correlated with pathologic features (pT, pN, G) and overall survival. GRP78 and GRP94 mRNA were expressed in all tumors. The relative gene expression of GRP78 was significantly higher in early cancers (pT1m and pT1sm) as compared to more advanced stages (pT2 and pT3) and normal tissue (p = 0.031). Highly differentiated tumors showed also higher GRP78 mRNA levels compared to moderate and low differentiated tumors (p = 0.035). In addition, patients with higher GRP78 levels tended to show a survival benefit (p = 0.07). GRP94 mRNA-levels showed no association to pathological features or clinical outcome.GRP78 and GRP94 protein expression was detectable by immunohistochemistry in all tumors. There was a significant correlation between a strong GRP78 protein expression and early tumor stages (pT1m and pT1sm, p = 0.038). For GRP94 low to moderate protein expression was significantly associated with earlier tumor stage (p = 0.001) and less lymph node involvement (p = 0.036). Interestingly, the patients with combined strong GRP78 and GRP94 protein expression exclusively showed either early (pT1m or pT1sm) or advanced (pT3) tumor stages and no pT2 stage (p = 0.031). We could demonstrate an association of GRP78 and GRP94 mRNA and protein expression with tumor stage and behaviour in esophageal adenocarcinomas. Increased expression of GRP78 may be responsible for controlling local tumor growth in early tumor stages, while high expression of GRP78 and GRP94 in advanced stages may be dependent from other factors like cellular stress reactions due to glucose deprivation, hypoxia or the hosts' immune response.


Reexamination of alcohol dehydrogenase structural mutants in Drosophila using protein blotting.
Using protein blotting and an immuno-overlay procedure, we have reexamined the cross-reacting material produced by ADH null-activity mutants generated with ethyl methanesulfonate (EMS). Of the 13 mutants, 11 have an immunodetectable polypeptide of wild-type size. The native and urea denatured isoelectric points (pI) establish that 7 of 13 of the mutations have no effect on protein charge. The electrophoretic mobilities of each variant on increasing percent acrylamide gels (Ferguson analysis), reveal that 9 of the 11 immunodetectable mutants have retained the ability to form dimers under native conditions. None of the inactive mutant proteins has the ability to form the "adduct-bound" isozyme. We have found no correlation between protein pI and in vivo stability. The observed frequencies of specific charge class alterations do not dispute the propensity of G:A transitions previously found for EMS mutagenesis.


Metachronous metastatic paraganglioma in jejunum as a rare entity: A case report.
Pheochromocytomas and paragangliomas are neuroendocrine tumors that arise from chromaffin cells of adrenal medulla and extra-adrenal paraganglia, respectively. The recurrence of these neuroendocrine tumors as a jejunal mass causing obstruction in the small intestine is an exceptional entity. The present study reports the case of a 70-year-old male who presented to the Emergency Department of Bezmialem Vakif University Hospital with abdominal pain and vomiting. The patient possessed a history of left nephrectomy due to malignant pheochromocytoma that had invaded into the left kidney eight months prior to presentation. Bowel obstruction was diagnosed and the patient underwent a laparoscopic procedure. Partial resection of the jejunum was performed and immunohistochemical studies revealed the lesion to be malignant paraganglioma. The majority of paragangliomas are chemo- and radioresistant. Surgical excision remains the primary treatment. Metachronous paraganglioma arising from the small intestine is an extremely rare entity and may be a relevant consideration in patients presenting with bowel obstruction.


Polycyclic aromatic hydrocarbons (PAHs) cycling and fates in Galveston Bay, Texas, USA.
The cycling and fate of polycyclic aromatic hydrocarbons (PAHs) is not well understood in estuarine systems. It is critical now more than ever given the increased ecosystem pressures on these critical coastal habitats. A budget of PAHs and cycling has been created for Galveston Bay (Texas) in the northwestern Gulf of Mexico, an estuary surrounded by 30-50% of the US capacity of oil refineries and chemical industry. We estimate that approximately 3 to 4 mt per year of pyrogenic PAHs are introduced to Galveston Bay via gaseous exchange from the atmosphere (ca. 2 mt/year) in addition to numerous spills of petrogenic PAHs from oil and gas operations (ca. 1.0 to 1.9 mt/year). PAHs are cycled through and stored in the biota, and ca. 20 to 30% of the total (0.8 to 1.5 mt per year) are estimated to be buried in the sediments. Oysters concentrate PAHs to levels above their surroundings (water and sediments) and contain substantially greater concentrations than other fish catch (shrimp, blue crabs and fin fish). Smaller organisms (infaunal invertebrates, phytoplankton and zooplankton) might also retain a significant fraction of the total, but direct evidence for this is lacking. The amount of PAHs delivered to humans in seafood, based on reported landings, is trivially small compared to the total inputs, sediment accumulation and other possible fates (metabolic remineralization, export in tides, etc.), which remain poorly known. The generally higher concentrations in biota from Galveston Bay compared to other coastal habitats can be attributed to both intermittent spills of gas and oil and the bay's close proximity to high production of pyrogenic PAHs within the urban industrial complex of the city of Houston as well as periodic flood events that transport PAHs from land surfaces to the Bay.


The flavonoid isoquercitrin promotes neurite elongation by reducing RhoA activity.
Neurite formation and synaptic patterning are fundamental to the development of a functional nervous system. Flavonoids are natural molecules known for having beneficial effects on brain health through diverse molecular pathways. Cytoskeletal changes occurring during neuritogenesis and synapse formation often involve Rho GTPases. Here we hypothesized that the flavonoid isoquercitrin promotes neuronal differentiation through Rho signalling. We performed time lapse imaging of NG108-15 cells during incubation with/without isoquercitrin. Isoquercitrin stimulated extensive neurites enriched in the synaptic vesicle protein synaptotagmin-1. Neurite extension was augmented by the ROCK inhibitor Y-27632 suggesting an inactivation of RhoA/Rho kinase as the mechanism. To test this, we first measured the dose-dependent effect of isoquercitrin on RhoA activity and found a 47% reduction in RhoA activity at concentrations which induced neurites (≥40 µM). Secondly, we tested the ability of isoquercitrin to rescue the neural phenotype in a model of RhoA-induced neurite retraction and found that 40 µM isoquercitrin added to cultures previously treated with the RhoA activator calpeptin produced significantly more neurite length/cell than calpeptin alone. Finally, we tested the hypothesis that isoquercitrin may affect RhoA localization preventing the translocation to the plasma membrane. Unexpectedly, immunolocalization studies showed that RhoA was present in nuclear compartments of control NG108-cells, but underwent translocation to the cytoplasm upon treatment with isoquercitrin. DNA microarrays and reverse transcription - quantitative PCR (RT-qPCR) revealed differences in global gene expression of Rho GTPase family members. These data taken together indicate that isoquercitrin is a potential stimulator of neuronal differentiation, through multiple Rho GTPase mediated mechanisms. As several members of the Rho GTPase family are implicated in human neurological disorders/injuries, our results suggest that isoquercitrin could be used in the treatment of these pathological states through its effect on this family of molecular switches.


Protein Z in normal pregnancy.
Changes in the coagulation and fibrinolytic systems during pregnancy lead to a higher risk of thromboembolism. These changes include the increase of many clotting factors, as well as a significant fall in activity of fibrinolytic proteins, such as protein C. Protein Z is a vitamin-K-dependent plasma glycoprotein and inhibits the activation of factor X by serving as a cofactor to a plasma proteinase inhibitor. Protein Z deficiency has recently been reported in women with unexplained early fetal losses, and antibodies to protein Z can contribute to adverse pregnancy outcomes. The aim of this study was to determine the range of protein Z in normal pregnancies at different gestational weeks in a cross-sectional and a longitudinal setting. In the longitudinal study we found a 20% increase (p=0.006) of protein Z from first trimester to delivery and a 30% decrease (p<0.0001) 6 to 12 weeks after delivery. In the cross-sectional study these findings were reproducible. In summary, our data show a progressive increase in protein Z levels with gestational age in normal pregnancies and a return to normal levels around 6 to 12 weeks postpartum. The normal increase of protein Z during pregnancy may balance the increase of clotting factors to protect pregnant women from thrombosis.


The importance of context: when relative relief renders pain pleasant.
Context can influence the experience of any event. For instance, the thought that "it could be worse" can improve feelings towards a present misfortune. In this study we measured hedonic feelings, skin conductance, and brain activation patterns in 16 healthy volunteers who experienced moderate pain in two different contexts. In the "relative relief context," moderate pain represented the best outcome, since the alternative outcome was intense pain. However, in the control context, moderate pain represented the worst outcome and elicited negative hedonic feelings. The context manipulation resulted in a "hedonic flip," such that moderate pain elicited positive hedonics in the relative relief context. Somewhat surprisingly, moderate pain was even rated as pleasant in this context, despite being reported as painful in the control context. This "hedonic flip" was corroborated by physiological and functional neuroimaging data. When moderate pain was perceived as pleasant, skin conductance and activity in insula and dorsal anterior cingulate were significantly attenuated relative to the control moderate stimulus. "Pleasant pain" also increased activity in reward and valuation circuitry, including the medial orbitofrontal and ventromedial prefrontal cortices. Furthermore, the change in outcome hedonics correlated with activity in the periacqueductal grey (PAG) of the descending pain modulatory system (DPMS). The context manipulation also significantly increased functional connectivity between reward circuitry and the PAG, consistent with a functional change of the DPMS due to the altered motivational state. The findings of this study point to a role for brainstem and reward circuitry in a context-induced "hedonic flip" of pain.


Minimally invasive treatments for venous compression syndromes.
The management of venous compression syndromes has historically been reliant on surgical treatment when conservative measures fail. There are, however, several settings in which endovascular therapy can play a significant role as an adjunct or even a replacement to more invasive surgical methods. We explore the role of minimally invasive treatment options for three of the most well-studied venous compression syndromes. The clinical aspects and pathophysiology of Paget-Schroetter syndrome (PSS), nutcracker syndrome, and May-Thurner syndrome are discussed in detail, with particular emphasis on the role that interventionalists can play in minimally invasive treatment.


Biology and ecology of Alchisme grossa in a cloud forest of the Bolivian Yungas.
Treehoppers (Membracidae) exhibit different levels of sociality, from solitary to presocial. Although they are one of the best biological systems to study the evolution of maternal care in insects, information on the biology of species in this group is scarce. This work describes the biology and ecology of Alchisme grossa (Fairmaire) (Hemiptera: Membracidae) in a rain cloud forest of Bolivia. This subsocial membracid utilizes two host-plant species, Brugmansia suaveolens (Humb. & Bonpl. ex Wild) Bercht. & J.Presl and Solanum ursinum (Rusby) (both Solanaceae), the first one being used during the whole year and the second one almost exclusively during the wet season. The development of A. grossa from egg to adult occurred on the plant where eggs were laid. Maternal care was observed during the complete nymphal development, and involved behavioral traits such as food facilitation and antidepredatory defense. Life cycle was longer on B. suaveolens during the dry season and shorter on S. ursinum during the wet season. Mortality was similar on both host plants during the wet season but was lower on B. suaveolens during the dry season. The presence of a secondary female companion to the egg-guarding female individual and occasional iteropary is also reported.


Multiplexed (18-Plex) Measurement of Signaling Targets and Cytotoxic T Cells in Trastuzumab-Treated Patients using Imaging Mass Cytometry.
Imaging mass cytometry (IMC) uses metal-conjugated antibodies to provide multidimensional, objective measurement of protein targets. We used this high-throughput platform to perform an 18-plex assessment of HER2 ICD/ECD, cytotoxic T-cell infiltration and other structural and signaling proteins in a cohort of patients treated with trastuzumab to discover associations with trastuzumab benefit. An antibody panel for detection of 18 targets (pan-cytokeratin, HER2 ICD, HER2 ECD, CD8, vimentin, cytokeratin 7, β-catenin, HER3, MET, EGFR, ERK 1-2, MEK 1-2, PTEN, PI3K p110 α, Akt, mTOR, Ki67, and Histone H3) was used with a selection of trastuzumab-treated patients from the Hellenic Cooperative Oncology Group 10/05 trial (n = 180), and identified a case-control series. Patients that recurred after adjuvant treatment with trastuzumab trended toward a decreased fraction of HER2 ECD pixels over threshold compared with cases without recurrence (P = 0.057). After exclusion of the lowest HER2 expressers, 5-year recurrence events were associated with reduced total extracellular domain (ECD)/intracellular domain (ICD) ratio intensity in tumor (P = 0.044). These observations are consistent with our previous work using quantitative immunofluorescence, but represent the proof on identical cell content. We also describe the association of the ECD of HER2 with CD8 T-cell infiltration on the same slide. The proximity of CD8 cells as a function of the expression of the ECD of HER2 provides further evidence for the role of the immune system in the mechanism of action of trastuzumab.


Optofluidic devices and applications in photonics, sensing and imaging.
Optofluidics integrates the fields of photonics and microfluidics, providing new freedom to both fields and permitting the realization of optical and fluidic property manipulations at the chip scale. Optofluidics was formed only after many breakthroughs in microfluidics, as understanding of fluid behaviour at the micron level enabled researchers to combine the advantages of optics and fluids. This review describes the progress of optofluidics from a photonics perspective, highlighting various optofluidic aspects ranging from the device's property manipulation to an interactive integration between optics and fluids. First, we describe photonic elements based on the functionalities that enable fluid manipulation. We then discuss the applications of optofluidic biodetection with an emphasis on nanosensing. Next, we discuss the progress of optofluidic lenses with an emphasis on its various architectures, and finally we conceptualize on where the field may lead.


Pharmacological and immunohistochemical characterization of the APJ receptor and its endogenous ligand apelin.
Apelin peptides have recently been identified to be the endogenous ligands for the G protein-coupled receptor APJ. However, little is known about the physiological roles of this ligand-receptor pairing. In the present study we investigated the pharmacology of several apelin analogues at the human recombinant APJ receptor using radioligand binding and functional assays. This has led to the identification of key residues in the apelin peptide required for functional potency and binding affinity through structure-activity studies. In particular, we have identified that replacement of leucine in position 5, or arginine in position 2 and 4 of the C-terminal apelin peptide, apelin-13, resulted in significant changes in pharmacology. We also investigated the detailed localization of pre-proapelin and APJ receptor mRNA in a wide range of human, rat and mouse tissues using quantitative RT-PCR, and carried out a detailed immunohistochemical study of the distribution of the APJ receptor in rat brain and spinal cord. Interestingly, the APJ receptor was not only co-localized in white matter with GFAP in the spinal cord, but was also clearly localized on neurones in the brain, suggesting that this receptor and its peptide may be involved in a wide range of biological process yet to be determined.


Fine-scale genetic structure among greater sage-grouse leks in central Nevada.
Mating systems that reduce dispersal and lead to non-random mating might increase the potential for genetic structure to arise at fine geographic scales. Greater sage-grouse (Centrocercus urophasianus) have a lek-based mating system and exhibit high site fidelity and skewed mating ratios. We quantified population structure by analyzing variation at 27,866 single-nucleotide polymorphisms in 140 males from ten leks (within five lek complexes) occurring in a small geographic region in central Nevada. Lek complexes, and to a lesser extent individual leks, formed statistically identifiable clusters in ordination analyses, providing evidence for fine-scale geographic genetic differentiation. Lek geography predicted genetic differentiation even at a small geographic scale, which could be sharpened by strong site fidelity. Relatedness was also higher among individuals within lek complexes (and leks), suggesting that reproductive skew, where few males participate in most of the successful matings, could also potentially contribute to genetic differentiation. Models incorporating a habitat resistance surface as a proxy for potentially reduced movement due to landscape features indicated that both geographic distance and habitat suitability (i.e. preferred habitat) predicted genetic structure, with no significant effect of man-made barriers to movement (i.e. power lines and roads). Finally, we illustrate how data sets containing fewer loci (<4000) had less statistical precision and failed to detect the full degree of genetic structure. Our results suggest that habitat features and lek site geography of sage-grouse shape fine scale genetic structure, and highlight how larger data sets can have increased precision and accuracy for quantifying ecologically relevant genetic structure over small geographic scales.


Nanoscale and Macroscale Scaffolds with Controlled-Release Polymeric Systems for Dental Craniomaxillofacial Tissue Engineering.
Tremendous progress in stem cell biology has resulted in a major current focus on effective modalities to promote directed cellular behavior for clinical therapy. The fundamental principles of tissue engineering are aimed at providing soluble and insoluble biological cues to promote these directed biological responses. Better understanding of extracellular matrix functions is ensuring optimal adhesive substrates to promote cell mobility and a suitable physical niche to direct stem cell responses. Further, appreciation of the roles of matrix constituents as morphogen cues, termed matrikines or matricryptins, are also now being directly exploited in biomaterial design. These insoluble topological cues can be presented at both micro- and nanoscales with specific fabrication techniques. Progress in development and molecular biology has described key roles for a range of biological molecules, such as proteins, lipids, and nucleic acids, to serve as morphogens promoting directed behavior in stem cells. Controlled-release systems involving encapsulation of bioactive agents within polymeric carriers are enabling utilization of soluble cues. Using our efforts at dental craniofacial tissue engineering, this narrative review focuses on outlining specific biomaterial fabrication techniques, such as electrospinning, gas foaming, and 3D printing used in combination with polymeric nano- or microspheres. These avenues are providing unprecedented therapeutic opportunities for precision bioengineering for regenerative applications.


Larch arabinogalactan: clinical relevance of a novel immune-enhancing polysaccharide.
Larch arabinogalactan is composed of greater than 98-percent arabinogalactan, a highly branched polysaccharide consisting of a galactan backbone with side-chains of galactose and arabinose sugars. Larch arabinogalactan is an excellent source of dietary fiber, and has been approved as such by the FDA. It has been shown to increase the production of short-chain fatty acids, principally butyrate and propionate, and has been shown to decrease the generation and absorption of ammonia. Evidence also indicates human consumption of larch arabinogalactan has a significant effect on enhancing beneficial gut microflora, specifically increasing anaerobes such as Bifidobacteria and Lactobacillus. Larch arabinogalactan has several interesting properties which appear to make it an ideal adjunctive supplement to consider in cancer protocols. Experimental studies have indicated larch arabinogalactan can stimulate natural killer (NK) cell cytotoxicity, enhance other functional aspects of the immune system, and inhibit the metastasis of tumor cells to the liver. The immune-enhancing properties also suggest an array of clinical uses, both in preventive medicine, due to its ability to build a more responsive immune system, and in clinical medicine, as a therapeutic agent in conditions associated with lowered immune function, decreased NK activity, or chronic viral infection.


Conditional Self-Entropy and Conditional Joint Transfer Entropy in Heart Period Variability during Graded Postural Challenge.
Self-entropy (SE) and transfer entropy (TE) are widely utilized in biomedical signal processing to assess the information stored into a system and transferred from a source to a destination respectively. The study proposes a more specific definition of the SE, namely the conditional SE (CSE), and a more flexible definition of the TE based on joint TE (JTE), namely the conditional JTE (CJTE), for the analysis of information dynamics in multivariate time series. In a protocol evoking a gradual sympathetic activation and vagal withdrawal proportional to the magnitude of the orthostatic stimulus, such as the graded head-up tilt, we extracted the beat-to-beat spontaneous variability of heart period (HP), systolic arterial pressure (SAP) and respiratory activity (R) in 19 healthy subjects and we computed SE of HP, CSE of HP given SAP and R, JTE from SAP and R to HP, CJTE from SAP and R to HP given SAP and CJTE from SAP and R to HP given R. CSE of HP given SAP and R was significantly smaller than SE of HP and increased progressively with the amplitude of the stimulus, thus suggesting that dynamics internal to HP and unrelated to SAP and R, possibly linked to sympathetic activation evoked by head-up tilt, might play a role during the orthostatic challenge. While JTE from SAP and R to HP was independent of tilt table angle, CJTE from SAP and R to HP given R and from SAP and R to HP given SAP showed opposite trends with tilt table inclination, thus suggesting that the importance of the cardiac baroreflex increases and the relevance of the cardiopulmonary pathway decreases during head-up tilt. The study demonstrates the high specificity of CSE and the high flexibility of CJTE over real data and proves that they are particularly helpful in disentangling physiological mechanisms and in assessing their different contributions to the overall cardiovascular regulation.


Issues of cause and control in patient accounts of Type 2 diabetes.
Patients experience considerable difficulties in making and sustaining health-related lifestyle changes. Many Type 2 diabetes patients struggle to follow disease risk-management advice even when they receive extensive information and support. Drawing on a qualitative study of patients with Type 2 diabetes, the paper uses discourse analysis to examine their accounts about disease causation and disease management, and the implications for how they respond to their condition and health services advice. As it is a multifactorial disease, biomedical discourse around Type 2 diabetes is complex. Patients are encouraged to grasp the complicated message that both cause and medical outcomes related to their condition are partly, but not wholly, within their control. Discursive constructions identified from respondent accounts indicate how these two messages are deployed variously by respondents when accounting for disease causation and management. While these constructions (identified in respondent accounts as 'Up to me' and 'Down to them') are a valuable resource for patients, equally they may be deployed in a selective and detrimental way. We conclude that clear messages from health professionals about effective disease management may help patients to position themselves more effectively in relation to their condition. More importantly, they might serve to hinder the availability of inappropriate and potentially harmful patient positions where patients either relinquish responsibility for disease management or reject all input from health professionals.


Current Concepts in the Treatment of Lateral Condyle Fractures in Children.
Lateral condyle fractures of the humerus are the second most common fracture about the elbow in children. The injury typically occurs as a result of a varus- or valgus-applied force to the forearm with the elbow in extension. Plain radiographs are sufficient in making the diagnosis; however, an elbow arthrogram permits optimal visualization of the articular surface in minimally displaced fractures. Traditionally, nonsurgical management is indicated for fractures with ≤2 mm of displacement and a congruent articular surface. Closed reduction and percutaneous pinning is performed for fractures with >2 mm of displacement with an intact cartilaginous hinge at the articular surface. Open reduction and internal fixation is often necessary for fractures with ≥4 mm of displacement or if there is articular incongruity. Complications include malunion, delayed presentation, fishtail deformity, lateral spurring, and growth arrest. Evolving management concepts include relative indications for surgical management, the optimal pin configuration, and the use of cannulated screw and bioresorbable fixation.


Contribution of Maternal Immunity to Decreased Rotavirus Vaccine Performance in Low- and Middle-Income Countries.
The role of maternal immunity, received by infants either transplacentally or orally from breast milk, in rotavirus vaccine (RV) performance is evaluated here. Breastfeeding withholding has no effect on vaccine responses, but higher levels of transplacental rotavirus-specific IgG antibody contribute to reduced vaccine seroconversion. The gaps in knowledge on the factors associated with low RV efficacy in low- and middle-income countries (LMIC) remain, and further research is needed to shed more light on these issues.


Structures of Escherichia coli branched-chain amino acid aminotransferase and its complexes with 4-methylvalerate and 2-methylleucine: induced fit and substrate recognition of the enzyme.
The following three-dimensional structures of three forms of Escherichia coli branched-chain amino acid aminotransferase (eBCAT) have been determined by the X-ray diffraction method: the unliganded pyridoxal 5'-phosphate (PLP) form at a 2.1 A resolution, and the two complexes with the substrate analogues, 4-methylvalerate (4-MeVA) as the Michaelis complex model and 2-methylleucine (2-MeLeu) as the external aldimine model at 2.4 A resolution. The enzyme is a trimer of dimers, and each subunit consists of small and large domains, and the interdomain loop. The active site is formed by the residues at the domain interface and those from two loops of the other subunit of the dimer unit, and binds one PLP with its re-face directed toward the protein side. Upon binding of a substrate, Arg40 changes its side-chain direction to interact with the interdomain loop, and the loop, which is disordered in the unliganded form, shows its ordered structure on the active-site cavity, interacts with the hydrophobic side chain of the substrate, and shields it from the solvent region. The substrate binds to the active-site pocket with its alpha-hydrogen toward the protein side, its side-chain on the side of O3 of PLP, and its alpha-carboxylate on the side of the phosphate group of PLP. The hydrophobic side-chain of the substrate is recognized by Phe36, Trp126, Tyr129, Tyr164, Tyr31*, and Val109*. The alpha-carboxylate of the substrate binds to the unique site constructed by three polar groups (two main-chain NH groups of the beta-turn at Thr257 and Ala258 and the hydroxy group of Tyr95) which are activated by the access of Arg40 to the main-chain C=O group of the beta-turn and the coordination of Arg97 to the hydroxy group. Since Arg40 is the only residue that significantly changes its side-chain conformation and directly interacts with the interdomain loop and the beta-turn, the residue plays important roles in the induced fit of the interdomain loop and the alpha-carboxylate recognition of the substrate.


Redox ratio of mitochondria as an indicator for the response of photodynamic therapy.
The effect of photodynamic therapy (PDT) treatment on the metabolic state of tumor mitochondria is investigated by imaging of tumor redox status. PDT is performed using the photosensitizer pyropheophorbide-2-deoxyglucosamide (Pyro-2DG), which utilizes the glucose import pathway. It is found that Pyro-2DG-induced PDT resulting in a highly oxidized state of tumor mitochondria. This is determined from the redox ratio changes derived from the intrinsic oxidized flavoprotein (Fp) and reduced pyridine nucleotide (PN) [i.e., reduced nicotinamide adenine dinucleotide (NADH)] fluorescence signals observed using a cryoimager. Thus, the redox ratio is a sensitive indicator for providing reliable and informative measurements of PDT-induced tissue damage. In the PDT treated region of the tumor, highly oxidized flavoprotein and diminishing NADH fluorescence is detected, suggesting that flavoprotein and NADH are oxidized by singlet oxygen produced in the photosensitization process.


Pharmacological inhibition of PTEN attenuates cognitive deficits caused by neonatal repeated exposures to isoflurane via inhibition of NR2B-mediated tau phosphorylation in rats.
Evidence has shown that children exposed to repeated anesthesia in early childhood display long-term cognitive disabilities. However, the underlying mechanisms remain largely unclear. Our previous study has indicated the involvement of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) in isoflurane-induced decrease of self-renewal capacity in hippocampal neural precursor cells. Additionally, it is demonstrated by others that PTEN inhibition could protect against cognitive impairment via reduction of tau phosphorylation in the alzheimer's disease model. Therefore, in the present in vivo study, we aimed to examine the effects of PTEN inhibition on the cognitive dysfunction and tau hyperphosphorylation caused by neonatal repeated exposures to isoflurane. Our results showed that the neonatal repeated exposures to isoflurane resulted in the activation of PTEN in the hippocampus. The treatment of PTEN inhibitor BPV (pic) restored PSD-95 synthesis, and attenuated tau phosphorylation as well as the cognitive dysfunction caused by the repeated isoflurane exposures. In addition, BPV (pic) treatment reversed the activation of NR2B-containing NMDARs induced by repeated isoflurane exposures, while in turn, the antagonism of NR2B subunit with ifenprodil alleviated tau phosphorylation, indicating a possible role of NR2B as the downstream of PTEN in mediating tau phosphorylation in the neonatal rats repeatedly exposed to isoflurane. In conclusion, our results reveal a novel role of PTEN in mediating tau phosphorylation and cognitive deficits caused by neonatal repeated exposures to isoflurane, implying that targeting on PTEN may be a potential therapeutic approach for the anesthetic-related cognitive decline in the developing brain.


The influence of health beliefs on the presentation and consultation outcome in patients with chemical sensitivities.
This study was carried out to investigate the impact of the physical effects of a chemical exposure, health and chemical beliefs, and chemical sensitivities treatment preferences on the consultation outcome at a tertiary liaison clinic. Eighty-five patients exposed to a range of chemicals were assessed at a joint medical toxicology and psychiatric clinic. Patient's beliefs about chemicals and health, chemical sensitivities and their treatment preferences were assessed using a 23-item questionnaire. Fifty-seven patients (69%) had suffered from a range of initial or delayed symptoms that were probably a clear physical consequence of the exposure (Group A), whereas 26 patients (31%) had not (Group B). There were no significant differences found between groups A and B in terms of their diagnosis and their beliefs about health, food, chemicals and chemical sensitivities treatment preferences. However, patients in Group A were significantly more likely to report moderate to severe symptoms in comparison to Group B. Consultation outcome too did not differ between the two groups. The only predictors of consultation outcome were the patients' chemical sensitivities treatment preferences. Patients who at the outset thought that their treatment should comprise of complete avoidance to chemicals, regular monitoring and the use of alternative rather than conventional medicine were significantly less likely to achieve a favourable consultation outcome. Patients' chemical sensitivities treatment preferences were related to the more general beliefs on health, food and the harmful nature of chemicals and were not related to the chemical exposure variables. These findings suggest that addressing patients' treatment preferences and the general beliefs on chemicals, food and health may enhance outcome and perhaps ought to be the target for intervention in context of such a liaison clinic.


Adolescent, parent, and observer perceptions of parenting: genetic and environmental influences on shared and distinct perceptions.
Agreement among reporters on features of family life, whether family members or outside observers, is considered to be low. This study, which involved a national sample of 720 families comprised of identical and fraternal twins, full siblings, half siblings, and biologically unrelated stepsiblings, examined the issue of low interrater agreement by decomposing the common and unique variance among parent, child, and observer reports of parenting behaviors (warmth and negativity) into genetic and environmental factors. Quantitative genetic analyses were employed to decompose the "Social" level of perception (common variance among parents, children, observers), the level of "Family" subculture (common variance only among parents and children), and the unique "Individual" level into genetic and environmental components. It was predicted that genetic factors would account for substantial portions of the variance at the Social and Family levels; nonshared environmental factors were expected to influence variance unique to child reports; and shared environmental factors were expected to influence variance unique to parent reports. A second and related aim of the study was to examine the subjective-objective dimension of genetic effects on measures of the environment. Results of model-fitting analyses generally supported the predictions for parental warmth and negativity at the Family and Individual levels. At the Social level, genetic factors were predominant for parental negativity and shared environmental factors for parental warmth. The findings are discussed in terms of genetically influenced child effects on parenting and methodological difficulties in constructing latent variables.


A longitudinal examination of the relationship between perfectionism and motivational climate in dance.
The present study examined the relationship between dance-related perfectionism and perceptions of motivational climate in dance over time. In doing so, three possibilities were tested: (a) perfectionism affects perceptions of the motivational climate, (b) perceptions of the motivational climate affect perfectionism, and (c) the relationship is reciprocal. Two hundred seventy-one young dancers (M = 14.21 years old, SD = 1.96) from UK Centres for Advanced Training completed questionnaires twice, approximately 6 months apart. Cross-lagged analysis indicated that perfectionistic concerns led to increased perceptions of an ego-involving climate and decreased perceptions of a task-involving climate over time. In addition, perceptions of a task-involving climate led to increased perfectionistic strivings over time. The findings suggest that perfectionistic concerns may color perceptions of training/performing environments so that mistakes are deemed unacceptable and only superior performance is valued. They also suggest that perceptions of a task-involving climate in training/performing environments may encourage striving for excellence and perfection without promoting excessive concerns regarding their attainment.


Excessive expression of miR-27 impairs Treg-mediated immunological tolerance.
MicroRNAs (miRs) are tightly regulated in the immune system, and aberrant expression of miRs often results in hematopoietic malignancies and autoimmune diseases. Previously, it was suggested that elevated levels of miR-27 in T cells isolated from patients with multiple sclerosis facilitate disease progression by inhibiting Th2 immunity and promoting pathogenic Th1 responses. Here we have demonstrated that, although mice with T cell-specific overexpression of miR-27 harbor dysregulated Th1 responses and develop autoimmune pathology, these disease phenotypes are not driven by miR-27 in effector T cells in a cell-autonomous manner. Rather, dysregulation of Th1 responses and autoimmunity resulted from a perturbed Treg compartment. Excessive miR-27 expression in murine T cells severely impaired Treg differentiation. Moreover, Tregs with exaggerated miR-27-mediated gene regulation exhibited diminished homeostasis and suppressor function in vivo. Mechanistically, we determined that miR-27 represses several known as well as previously uncharacterized targets that play critical roles in controlling multiple aspects of Treg biology. Collectively, our data show that miR-27 functions as a key regulator in Treg development and function and suggest that proper regulation of miR-27 is pivotal to safeguarding Treg-mediated immunological tolerance.


Systematic Review of Microthrombi in COVID-19 Autopsies.
Histopathological analysis can provide additional clues in COVID-19 understanding. During the last year, autopsy reports have revealed that diffuse alveolar damage (DAD) is the most significant observed finding. The aim of this study is to review cases in the literature about COVID-19 autopsies that reported microthrombi in different organs. We performed a systematic literature review in PubMed, Virtual Health Library (VHL), and Google Scholar. In total, 151 autopsies were included, and 91 cases presented microthrombi in the lung (73%), heart (11.2%), kidney (24%), and liver (16.3%). The age range was between 27 and 96 years. Males were 64.8%. The patients with microthrombi had more comorbidities such as arterial hypertension (62%), obesity or overweight (64%), diabetes mellitus type 2 (51%), and heart disease (53%). The most common histopathological changes found in patients with lung microthrombosis were DAD in exudative phase (78%), pulmonary embolism (59%), and lung infarct (81%). Presence of microthrombi was associated with arterial hypertension (p < 0.0001) and DAD in exudative and proliferative phases (p = 0.02). The analysis of these results shows that microthrombi in COVID-19 autopsies may be found in different organs and are more frequent in patients with comorbidities, pulmonary embolism, and lung infarct.


Using participatory action research in community-based rehabilitation for people with acquired brain injury: from service provision to partnership with Aboriginal communities.
Community-based rehabilitation (CBR) developed in response to delivery of rehabilitation services to people with disability in developing countries, and appears appropriate to address rehabilitation needs of rural and remote populations, including Australian Aboriginal People with acquired brain injury (ABI). This article will describe participatory action research (PAR) as a vehicle for exploring and translating the CBR model within a mainstream brain injury rehabilitation service in Queensland, Australia. PAR was conducted with two self-selected remote Aboriginal communities in Far North Queensland. Key components to this project were the employment of a local Aboriginal worker, facilitating community engagement and consultation. PAR elements of planning, action and review were conducted through individual and group meetings and activities within the communities across a 3-year period. The project has facilitated expansion and change within the current brain injury rehabilitation service model in line with CBR philosophical foundations, including community development and partnership as a desirable way of engaging with key stakeholders. The focus on community consultation through PAR and the development of community partnerships has increased the cultural competency of the rehabilitation service, the capacity of participating communities and of the sector to respond in ways that are valued and owned by Aboriginal People with brain injury, their families and communities.


Microglia Regulate Neuroglia Remodeling in Various Ocular and Retinal Injuries.
Reactive microglia and infiltrating peripheral monocytes have been implicated in many neurodegenerative diseases of the retina and CNS. However, their specific contribution in retinal degeneration remains unclear. We recently showed that peripheral monocytes that infiltrate the retina after ocular injury in mice become permanently engrafted into the tissue, establishing a proinflammatory phenotype that promotes neurodegeneration. In this study, we show that microglia regulate the process of neuroglia remodeling during ocular injury, and their depletion results in marked upregulation of inflammatory markers, such as Il17f, Tnfsf11, Ccl4, Il1a, Ccr2, Il4, Il5, and Csf2 in the retina, and abnormal engraftment of peripheral CCR2+ CX3CR1+ monocytes into the retina, which is associated with increased retinal ganglion cell loss, retinal nerve fiber layer thinning, and pigmentation onto the retinal surface. Furthermore, we show that other types of ocular injuries, such as penetrating corneal trauma and ocular hypertension also cause similar changes. However, optic nerve crush injury-mediated retinal ganglion cell loss evokes neither peripheral monocyte response in the retina nor pigmentation, although peripheral CX3CR1+ and CCR2+ monocytes infiltrate the optic nerve injury site and remain present for months. Our study suggests that microglia are key regulators of peripheral monocyte infiltration and retinal pigment epithelium migration, and their depletion results in abnormal neuroglia remodeling that exacerbates neuroretinal tissue damage. This mechanism of retinal damage through neuroglia remodeling may be clinically important for the treatment of patients with ocular injuries, including surgical traumas.


Fluoride exposure from groundwater as reflected by urinary fluoride and children's dental fluorosis in the Main Ethiopian Rift Valley.
This cross-sectional study explores the relationships between children's F(-) exposure from drinking groundwater and urinary F(-) concentrations, combined with dental fluorosis (DF) in the Main Ethiopian Rift (MER) Valley. We examined the DF prevalence and severity among 491 children (10 to 15 years old) who are life-long residents of 33 rural communities in which groundwater concentrations of F(-) cover a wide range. A subset of 156 children was selected for urinary F(-) measurements. Our results showed that the mean F(-) concentrations in groundwater were 8.5 ± 4.1 mg/L (range: 1.1-18 mg/L), while those in urine were 12.1±7.3 mg/L (range: 1.1-39.8 mg/L). The prevalence of mild, moderate, and severe DF in children's teeth was 17%, 29%, and 45%, respectively, and the majority (90%; n=140) of the children had urinary F(-) concentrations above 3 mg/L. Below this level most of the teeth showed mild forms of DF. The exposure-response relationship between F(-) and DF was positive and non-linear, with DF severity tending to level off above a F(-) threshold of ~6 mg/L, most likely due to the fact that at ~6 mg/L the enamel is damaged as much as it can be clinically observed in most children. We also observed differential prevalence (and severity) of DF and urinary concentration, across children exposed to similar F(-) concentrations in water, which highlights the importance of individual-specific factors in addition to the F(-) levels in drinking water. Finally, we investigated urinary F(-) in children from communities where defluoridation remediation was taking place. The lower F(-) concentration measured in urine of this population demonstrates the capacity of the urinary F(-) method as an effective monitoring and evaluation tool for assessing the outcome of successful F(-) mitigation strategy in relatively short time (months) in areas affected with severe fluorosis.


Polymorphisms of Cx(3)CR1 and CXCR6 receptors in relation to HAART therapy of HIV type 1 patients.
The chemokine polymorphisms CXCR6-3E/K, In1.1T/C, H7 haplotype, CX(3)CR1-V249I, and CX(3)CR1-T280M have been shown to affect the course of HIV infection. We studied their influence on immunologic and virologic response to HAART in a group of 143 HIV-1 patients. We performed Kaplan-Meier analysis using the following end-point criteria: (1) time from HAART initiation to undetectable viral load (VL < 50 copies/ml), (2) maximum duration of viral suppression, (3) time from HAART administration until CD4 elevation above 200 cells/microl for patients with baseline CD4 below 200 cells/microl and above 500 cells/microl for patients with baseline CD4 between 200 and 500 cells/microl, respectively, and (4) time from HAART initiation until CD4 reduction below baseline values. Our results revealed an improved immunologic response to HAART in patients with the CX(3)CR1-249I or CX(3)CR1-280M allele. On the contrary, patients with initial VL suppression due to HAART showed a faster virologic failure in the presence of the CXCR6-3K allele. The In1.1T/C polymorphism and H7 haplotype did not reveal any specific effect on HAART response.


Case Report of Kikuchi-Fujimoto Disease from Sub-Saharan Africa: An Important Mimic of Tuberculous Lymphadenitis.
Kikuchi-Fujimoto disease (KFD) is a rare form of painful lymphadenopathy, usually cervical, which is more common in Southeast Asia and rarely reported from Africa. Symptoms are usually nonspecific (fever, night sweats, etc.), and can mimic more common diseases such as tuberculosis (TB) in endemic areas. We report a case of a 29-year-old black African woman who was admitted with headache, neck pain, fever, and lymphadenopathy. She was found to have aseptic meningitis, eventually attributed to TB based on cervical node biopsy, although further histology suggested KFD. Blood tests for systemic lupus erythematosus (SLE) were negative; she had already been commenced on anti-TB treatment and had responded well and so was continued with this therapy. She was also later diagnosed with Hashimoto's thyroiditis 3 months after her diagnosis of KFD. Five months after stopping TB treatment, she was readmitted with the same symptoms and associated painless lymphadenopathy. Repeat biopsy was morphologically similar to that of 2017, and repeat evaluation confirmed SLE. She has since been managed by a rheumatologist and continues to do well.


Nicotine gates long-term potentiation in the hippocampal CA1 region via the activation of alpha2* nicotinic ACh receptors.
Hippocampal CA1 pyramidal cells receive two major excitatory synaptic inputs via the Schaffer collateral (SC) and temporoammonic (TA) pathways. Nicotine promotes induction of long-term potentiation (LTP) in the SC path; however, it is not known whether the modulatory effect of nicotine on LTP induction is pathway-specific. Here we show that nicotine suppresses LTP induction in the TA path. Interestingly, these opposing effects of nicotine were absent or greatly reduced in alpha2 nicotinic acetylcholine receptor (nAChR)-knockout (KO) mice, suggesting that an alpha2-containing nAChR subtype mediates these effects. Optical imaging with a voltage-sensitive dye revealed significantly stronger membrane depolarization in the presence of nicotine in the SC path, facilitating spread of excitatory neural activity along both the somatodendritic and the CA1 proximodistal axes. These effects of nicotine were also absent in alpha2 nAChR-KO mice, suggesting that the enhanced optical signal is related to the nicotine-induced facilitation of LTP induction. In contrast, in the TA path nicotine terminated depolarization more quickly and increased the delayed hyperpolarization in the termination zone of the TA path input. These inhibitory effects of nicotine were absent in alpha2 nAChR-KO mice and, thus, most probably underlie the nicotine-induced suppression of LTP induction. Our results suggest that nicotine influences the local balance between excitation and inhibition, gates LTP, and directs information flow through the hippocampal circuits via the activation of alpha2* nAChRs. These effects of nicotine may represent the cellular basis of nicotine-mediated cognitive enhancement.


Older Cannabis Users Are Not All Alike: Lifespan Cannabis Use Patterns.
Although several studies have examined individual-level correlates of cannabis use in later life, there is scant evidence identifying heterogeneity among older users. Using data from Colorado, this study examines variability in lifespan patterns of cannabis use among individuals aged 60 years and older. Sample respondents reported cannabis use in the past year and frequency of use in four periods of adulthood. Analyses used a multi-way contingency table to identify mutually exclusive subgroups of cannabis users based on lifetime reports of use and linear probability models to identify predictors of group identity. Three subgroups of older cannabis users were identified: new users, stop-out or intermittent users, and consistent users. The three groups varied on current use frequency and method of ingestion, as well as social and health characteristics. Screening for past history of cannabis use may help health care providers identify older adults who need health information and monitoring related to cannabis use.


Treating Acute Pain in the Opiate-Dependent Patient.
Opioid drugs, including prescription as well as heroin, have come to the national spotlight due to the unprecedented rate of overdose and addiction. The Centers for Disease Control and Prevention (CDC) has termed this problem as an "epidemic" that has reached record numbers of deaths in 2014. Approximately half of these deaths are the result from prescribed opioids. Also on the rise are the numbers of individuals who are diagnosed with chronic pain and are treated with opioids, methadone and buprenorphine. Individuals currently taking opioids for chronic pain confound the treatment of acute pain after traumatic injury. Goals of treatment include effective pain relief, prevention of opioid withdrawal, and managing the associated behavioral and psychological factors with drug addiction and dependence. The CDC has put forth guidelines on how to treat chronic pain but has yet to provide recommendations on how to treat acute pain in this unique population. The purpose of this literature review is to provide resources to treat pain, given a tolerant opioid-dependent patient.


Molecular definition of the 22q11 deletions in velo-cardio-facial syndrome.
Velo-cardio-facial syndrome (VCFS) is a common genetic disorder among individuals with cleft palate and is associated with hemizygous deletions in human chromosome 22q11. Toward the molecular definition of the deletions, we constructed a physical map of 22q11 in the form of overlapping YACs. The physical map covers > 9 cM of genetic distance, estimated to span 5 Mb of DNA, and contains a total of 64 markers. Eleven highly polymorphic short tandem-repeat polymorphic (STRP) markers were placed on the physical map, and 10 of these were unambiguously ordered. The 11 polymorphic markers were used to type the DNA from a total of 61 VCFS patients and 49 unaffected relatives. Comparison of levels of heterozygosity of these markers in VCFS patients and their unaffected relatives revealed that four of these markers are commonly hemizygous among VCFS patients. To confirm these results and to define further the breakpoints in VCFS patients, 15 VCFS individuals and their unaffected parents were genotyped for the 11 STRP markers. Haplotypes generated from this study revealed that 82% of the patients have deletions that can be defined by the STRP markers. The results revealed that all patients who have a deletion share a common proximal breakpoint, while there are two distinct distal breakpoints. Markers D22S941 and D22S944 appear to be consistently hemizygous in patients with deletions. Both of these markers are located on a single nonchimeric YAC that is 400 kb long. The results also show that the parental origin of the deleted chromosome does not have any effect on the phenotypic manifestation.


Occurrence and stability of insertion sequences in Mycobacterium tuberculosis complex strains: evaluation of an insertion sequence-dependent DNA polymorphism as a tool in the epidemiology of tuberculosis.
In this study we established the usefulness of DNA fingerprinting for the epidemiology of tuberculosis on the basis of the DNA polymorphism generated by the insertion sequence (IS) IS986. Although clinical isolates of Mycobacterium tuberculosis displayed a remarkably high degree of restriction fragment length polymorphism, we showed that transposition of this IS element is an extremely rare event in M. tuberculosis complex strains grown either in vitro or in vivo for long periods of time. The M. tuberculosis and Mycobacterium africanum strains tested in this study contained 6 to 17 IS copies. In the Mycobacterium bovis strains, the copy numbers ranged between 1 and 5, and all 27 M. bovis BCG strains investigated invariably contained a single IS copy. This copy was located at a unique chromosomal position, reinforcing the idea that the frequency of IS transposition is very low in M. tuberculosis complex strains. Various microepidemics are described in which each microepidemic corresponds to a particular fingerprint type. The extent of similarity between Dutch and African strains was quantitatively assessed by computer-assisted analysis of DNA fingerprints. The results indicate that M. tuberculosis strains from regions in central Africa, where tuberculosis is highly prevalent, are generally more related to each other than isolates from the Netherlands, where the transmission rate is low and where the majority of the tuberculosis cases are presumed to be the result of reactivation of previously contracted M. tuberculosis infections.


A Hemodynamic Comparison of Myocardial Bridging and Coronary Atherosclerotic Stenosis: A Computational Model With Experimental Evaluation.
Myocardial bridging (MB) and coronary atherosclerotic stenosis can impair coronary blood flow and may cause myocardial ischemia or even heart attack. It remains unclear how MB and stenosis are similar or different regarding their impacts on coronary hemodynamics. The purpose of this study was to compare the hemodynamic effects of coronary stenosis and MB using experimental and computational fluid dynamics (CFD) approaches. For CFD modeling, three MB patients with different levels of lumen obstruction, mild, moderate, and severe were selected. Patient-specific left anterior descending (LAD) coronary artery models were reconstructed from biplane angiograms. For each MB patient, the virtually healthy and stenotic models were also simulated for comparison. In addition, an in vitro flow-loop was developed, and the pressure drop was measured for comparison. The CFD simulations results demonstrated that the difference between MB and stenosis increased with increasing MB/stenosis severity and flowrate. Experimental results showed that increasing the MB length (by 140%) only had significant impact on the pressure drop in the severe MB (39% increase at the exercise), but increasing the stenosis length dramatically increased the pressure drop in both moderate and severe stenoses at all flow rates (31% and 93% increase at the exercise, respectively). Both CFD and experimental results confirmed that the MB had a higher maximum and a lower mean pressure drop in comparison with the stenosis, regardless of the degree of lumen obstruction. A better understanding of MB and atherosclerotic stenosis may improve the therapeutic strategies in coronary disease patients and prevent acute coronary syndromes.


The Shamrock lumbar plexus block: A dose-finding study.
The Shamrock technique is a new method for ultrasound-guided lumbar plexus blockade. Data on the optimal local anaesthetic dose are not available. The objective of this study is to estimate the effective dose of ropivacaine 0.5% for a Shamrock lumbar plexus block. A prospective dose-finding study using Dixon's up-and-down sequential method. University Hospital Orthopaedic Anaesthesia Unit. Shamrock lumbar plexus block performance and block assessment were scheduled preoperatively. Ropivacaine 0.5% was titrated with the Dixon and Massey up-and-down method using a stepwise change of 5 ml in each consecutive patient. Combined blocks of the femoral, the lateral femoral cutaneous and the obturator nerve were prerequisite for a successful lumbar plexus block. Thirty patients scheduled for lower limb orthopaedic surgery completed the study. The minimum effective anaesthetic volume of ropivacaine 0.5% (ED50) to achieve a successful Shamrock lumbar plexus block in 50% of the patients. Further analysis of the data was performed with a logistic regression model to calculate ED95 and to estimate the effective doses for a sensory lumbar plexus block not requiring a motor block of the femoral nerve. The Dixon and Massay estimate of the ED50 was 20.4 [95% confidence interval (95% CI) 13.9 to 30.0] ml ropivacaine 0.5%. The logistic regression estimate of the ED95 was 36.0 (95% CI 19.7 to 52.2) ml ropivacaine 0.5%. For a sensory lumbar plexus block, the ED50 was 17.1 (95% CI 12.3 to 21.9) ml and the ED95 was 25.8 (95% CI 18.6 to 33.1) ml. A volume of 20.4 ml ropivacaine 0.5% provided a successful Shamrock lumbar plexus block in 50% of the patients. A volume of 36.0 ml would be successful in 95% of the patients. ClinicalTrials.gov identifier NCT01956617.


Achievement of steady state optimizes results when performing indirect calorimetry.
The use of steady state as the endpoint for performance of indirect calorimetry (IC) is controversial. We designed this prospective study to evaluate the necessity and significance of achieving steady state. Patients with respiratory failure placed on mechanical ventilation in a short- or long-term acute care unit at any 1 of 3 university-based urban hospitals were eligible for the study. The 24-hour total energy expenditure (TEE) was determined by a Nellcor Puritan Bennett 7250 continuous IC monitor. Measured gas exchange parameters were obtained and averaged every 1 minute for the initial hour and then every 15 minutes for the next 23 hours. Over the initial hour, resting energy expenditure (REE) was averaged for intervals over the first 20, 30, 40, and 60 minutes, and for various definitions of steady state where oxygen consumption (VO2) and carbon dioxide production (VCO2) changed by <10%, 15%, and 20%. Coefficient of variation (CV) was calculated for VO2 over the first 30 minutes of study. Twenty-two patients (mean age, 52.8 years, 59% male, mean Acute Physiology and Chronic Health Evaluation (APACHE III) score 42.0) were entered in the study. The best correlation between short-term "snapshot" REE and the 24-hour TEE was achieved by the steady-state period defined by the most stringent criteria (change in VO2 and VCO2 by <10%). The average REE for all steady-state and interval periods correlated significantly to TEE with no significant difference in the absolute values for REE and TEE. Adding 10% for an activity factor to the average REE for each steady-state and interval period again correlated to TEE in a similar fashion with the same R value, but the absolute values for REE + 10% for all steady-state and interval periods were significantly different than the corresponding TEE. In those patients with less variation (CV for VO2 < or = 9.0), the REE obtained for the steady-state period defined by the most stringent criteria still had the best correlation, but similar correlation could be obtained by interval testing of > or = 30-minute duration. In those patients with greater variation (CV for VO2 >9.0), interval testing of at least 60 minutes or more was required to attain levels of correlation similar to that achieved by the steady-state period defined by the most stringent criteria. These data support the use of steady state, best defined as an interval of 5 consecutive minutes whereby VO2 and VCO2 change by <10%. The mean REE from this period correlates best to the 24-hour TEE regardless of CV. IC testing can be completed after achievement of steady state. Activity factors of 10% to 15% should not be added to the steady-state REE, because this practice significantly decreases the accuracy. In patients who fail to achieve steady state, the CV helps to determine the appropriate duration of IC testing. In those patients with a low CV (< or = 9.0), 30-minute test duration is adequate. In patients with CV >9.0, test duration of at least 60 minutes may be required. These latter patients should be considered for 24-hour IC testing.


Diversity of honey stores and their impact on pathogenic bacteria of the honeybee, Apis mellifera.
Honeybee colonies offer an excellent environment for microbial pathogen development. The highest virulent, colony killing, bacterial agents are Paenibacillus larvae causing American foulbrood (AFB), and European foulbrood (EFB) associated bacteria. Besides the innate immune defense, honeybees evolved behavioral defenses to combat infections. Foraging of antimicrobial plant compounds plays a key role for this "social immunity" behavior. Secondary plant metabolites in floral nectar are known for their antimicrobial effects. Yet, these compounds are highly plant specific, and the effects on bee health will depend on the floral origin of the honey produced. As worker bees not only feed themselves, but also the larvae and other colony members, honey is a prime candidate acting as self-medication agent in honeybee colonies to prevent or decrease infections. Here, we test eight AFB and EFB bacterial strains and the growth inhibitory activity of three honey types. Using a high-throughput cell growth assay, we show that all honeys have high growth inhibitory activity and the two monofloral honeys appeared to be strain specific. The specificity of the monofloral honeys and the strong antimicrobial potential of the polyfloral honey suggest that the diversity of honeys in the honey stores of a colony may be highly adaptive for its "social immunity" against the highly diverse suite of pathogens encountered in nature. This ecological diversity may therefore operate similar to the well-known effects of host genetic variance in the arms race between host and parasite.


Lateral Versus Medial Hallux Excision in Preaxial Polydactyly of the Foot.
In preaxial polydactyly of the foot, the choice for excision of the lateral or medial hallux is not straightforward, in particular with proximal phalangeal (type IV) and metatarsal (type VI) duplication, because of anatomical characteristics. We evaluated whether medial or lateral hallux excision gives better outcomes in these duplication types, to help clinical decision making. Children with type IV or type VI duplication (n=14, age: 4.4-17.2 years), who were operatively treated by excision of the lateral or medial hallux, were assessed for foot function using plantar pressure measurements and clinical examination. Foot aesthetics were scored by the child, an expert, and 10 laypersons, and additional patient-reported outcome questionnaires were obtained. Outcomes were compared between lateral and medial excision, per duplication type. In type IV duplication (n=11), lateral excision showed a better distribution of peak pressure between the hallux and first metatarsal with significantly lower median first metatarsal peak pressure (P = .008). Lateral excision showed more medial hallux deviation (P = .017). Foot aesthetics were not different between excision sides. In type VI duplication (n=12), lateral excision showed a 59% higher hallux peak pressure, larger medial hallux deviation (P = .004), and more reoperations. Foot aesthetics were scored significantly better after lateral excision by experts and laypersons. Foot function by virtue of plantar pressure was better after lateral hallux excision in type IV and after medial hallux excision in type VI duplication. Surgeons and laypersons perceived the foot as more normal after lateral excision in type VI, whereas children reported no differences. These outcomes can be used in clinical decision making. Level III, therapeutic, comparative study.


Variations in optical coherence tomography resolution and uniformity: a multi-system performance comparison.
Point spread function (PSF) phantoms based on unstructured distributions of sub-resolution particles in a transparent matrix have been demonstrated as a useful tool for evaluating resolution and its spatial variation across image volumes in optical coherence tomography (OCT) systems. Measurements based on PSF phantoms have the potential to become a standard test method for consistent, objective and quantitative inter-comparison of OCT system performance. Towards this end, we have evaluated three PSF phantoms and investigated their ability to compare the performance of four OCT systems. The phantoms are based on 260-nm-diameter gold nanoshells, 400-nm-diameter iron oxide particles and 1.5-micron-diameter silica particles. The OCT systems included spectral-domain and swept source systems in free-beam geometries as well as a time-domain system in both free-beam and fiberoptic probe geometries. Results indicated that iron oxide particles and gold nanoshells were most effective for measuring spatial variations in the magnitude and shape of PSFs across the image volume. The intensity of individual particles was also used to evaluate spatial variations in signal intensity uniformity. Significant system-to-system differences in resolution and signal intensity and their spatial variation were readily quantified. The phantoms proved useful for identification and characterization of irregularities such as astigmatism. Our multi-system results provide evidence of the practical utility of PSF-phantom-based test methods for quantitative inter-comparison of OCT system resolution and signal uniformity.


Effect of the extracts of the spiderflower, Cleome arabica, on feeding and survival of larvae of the cotton leafworm, Spodoptera littoralis.
Aqueous and organic (hexane, chloroform, and methanol) extracts of siliquae, stems and leaves, and seeds of Cleome arabica L. (Brassicales: Capparidaceae) were evaluated in the laboratory for their antifeeding and insecticidal effect on larvae of the cotton leafworm, Spodoptera littoralis (Boisduval) (Lepidoptera, Noctuidae), using a leaf dipping bioassay with castor bean, Ricinus communis L. (Malpighiales: Euphorbiaceae), leaf discs. The polar extracts caused significant mortality. At the highest dose, C. arabica extracts exhibited significant antifeeding and phagostimulating activities against S. littoralis larvae. Under no-choice conditions, the methanol extract of siliquae was the most active, and the antifeedant index calculated over 24 hr for 3rd instar larvae varied significantly from 16 to 37%. Using nutritional indices, it was established that there was a significant decrease in growth rate concomitant with a reduction in consumption. These results suggest the presence of anti-feeding and/or toxic substances in the extracts that may be useful in developing bio-insecticides based on C. arabica extracts for use in integrated pest management of leafworm and other agricultural pests.


Gaze modulation of visual aftereffects.
Physiological studies of non-human primates have suggested that the direction of gaze can modulate the gain of neuronal responses to visual stimuli in many cortical areas including V1. The neural gaze modulation is suggested to subserve the conversion from gaze-independent (eye-centered) to dependent (e.g., head-centered) representations. However, it has not been established whether the gaze modulation has significant influences on human visual perception. Here we show that gaze direction modestly but significantly modulates the magnitudes of the motion aftereffect, the tilt aftereffect and the size aftereffect. These aftereffects were stronger when the adaptation and test patterns were presented in the same gaze direction, than when they were presented in different gaze directions, even though the patterns always stimulated the same retinal location. The gaze modulation effect was not statistically significant for the post-adaptation elevation of contrast detection thresholds. The gaze modulation of visual aftereffects provides a useful psychophysical tool to analyze human cortical processes for coordinate transformations of visual space.


Intracellular transport, assembly, and degradation of wild-type and disease-linked mutant gap junction proteins.
More than 130 different mutations in the gap junction integral plasma membrane protein connexin32 (Cx32) have been linked to the human peripheral neuropathy X-linked Charcot-Marie-Tooth disease (CMTX). How these various mutants are processed by the cell and the mechanism(s) by which they cause CMTX are unknown. To address these issues, we have studied the intracellular transport, assembly, and degradation of three CMTX-linked Cx32 mutants stably expressed in PC12 cells. Each mutant had a distinct fate: E208K Cx32 appeared to be retained in the endoplasmic reticulum (ER), whereas both the E186K and R142W mutants were transported to perinuclear compartments from which they trafficked either to lysosomes (R142W Cx32) or back to the ER (E186K Cx32). Despite these differences, each mutant was soluble in nonionic detergent but unable to assemble into homomeric connexons. Degradation of both mutant and wild-type connexins was rapid (t(1/2) < 3 h) and took place at least in part in the ER by a process sensitive to proteasome inhibitors. The mutants studied are therefore unlikely to cause disease by accumulating in degradation-resistant aggregates but instead are efficiently cleared from the cell by quality control processes that prevent abnormal connexin molecules from traversing the secretory pathway.


The effect of xenon on fetal neurodevelopment following maternal sevoflurane anesthesia and laparotomy in rabbits.
There is concern that maternal anesthesia during pregnancy impairs brain development of the human fetus. Xenon is neuroprotective in pre-clinical models of anesthesia-induced neurotoxicity in neonates. It is not known if xenon also protects the developing fetal brain when administered in addition to maternal sevoflurane-anesthesia during pregnancy. To investigate the effects of sevoflurane and xenon on neurobehaviour and neurodevelopment of the offspring in a pregnant rabbit model. Pregnant rabbits on post-conception day 28 (term = 31d) underwent two hours of general anesthesia with 1 minimum alveolar concentration (MAC) of sevoflurane in 30% oxygen (n = 17) or 1 MAC sevoflurane plus 50-60 % xenon in 30% oxygen (n = 10) during a standardized laparotomy while receiving physiological monitoring. A sham-group (n = 11) underwent monitoring alone for two hours. At term, the rabbits were delivered by caesarean section. On the first postnatal day, neonatal rabbits underwent neurobehavioral assessment using a validated test battery. Following euthanasia, the brains were harvested for neurohistological analysis. A mixed effects-model was used for statistical analysis. Maternal cardiopulmonary parameters during anesthesia were within the reference range. Fetal survival rates were significantly higher in the sham-group as compared to the sevoflurane-group and the fetal brain/body weight ratio was significantly lower in the sevoflurane-group as compared with the sham- and xenon-group. Pups antenatally exposed to anesthesia had significantly lower motor and sensory neurobehavioral scores when compared to the sham-group (mean ± SD; sevo: 22.70 ± 3.50 vs. sevo+xenon: 22.74 ± 3.15 vs. sham: 24.37 ± 1.59; overall p = 0.003; sevo: 14.98 ± 3.00 vs. sevo+xenon: 14.80 ± 2.83 vs. sham: 16.43 ± 2.63; overall p = 0.006; respectively). Neuron density, neuronal proliferation and synaptic density were reduced in multiple brain regions of the exposed neonates. The co-administration of xenon had no measurable neuroprotective effects in this model. In rabbits, sevoflurane anesthesia for a standardized laparotomy during pregnancy resulted in impaired neonatal neurobehavior and a decreased neuron count in several regions of the neonatal rabbit brain. Co-administration of xenon did not prevent this effect.


Genetic characterization and role in virulence of the ribonucleotide reductases of Streptococcus sanguinis.
Streptococcus sanguinis is a cause of infective endocarditis and has been shown to require a manganese transporter called SsaB for virulence and O2 tolerance. Like certain other pathogens, S. sanguinis possesses aerobic class Ib (NrdEF) and anaerobic class III (NrdDG) ribonucleotide reductases (RNRs) that perform the essential function of reducing ribonucleotides to deoxyribonucleotides. The accompanying paper (Makhlynets, O., Boal, A. K., Rhodes, D. V., Kitten, T., Rosenzweig, A. C., and Stubbe, J. (2014) J. Biol. Chem. 289, 6259-6272) indicates that in the presence of O2, the S. sanguinis class Ib RNR self-assembles an essential diferric-tyrosyl radical (Fe(III)2-Y(•)) in vitro, whereas assembly of a dimanganese-tyrosyl radical (Mn(III)2-Y(•)) cofactor requires NrdI, and Mn(III)2-Y(•) is more active than Fe(III)2-Y(•) with the endogenous reducing system of NrdH and thioredoxin reductase (TrxR1). In this study, we have shown that deletion of either nrdHEKF or nrdI completely abolishes virulence in an animal model of endocarditis, whereas nrdD mutation has no effect. The nrdHEKF, nrdI, and trxR1 mutants fail to grow aerobically, whereas anaerobic growth requires nrdD. The nrdJ gene encoding an O2-independent adenosylcobalamin-cofactored RNR was introduced into the nrdHEKF, nrdI, and trxR1 mutants. Growth of the nrdHEKF and nrdI mutants in the presence of O2 was partially restored. The combined results suggest that Mn(III)2-Y(•)-cofactored NrdF is required for growth under aerobic conditions and in animals. This could explain in part why manganese is necessary for virulence and O2 tolerance in many bacterial pathogens possessing a class Ib RNR and suggests NrdF and NrdI may serve as promising new antimicrobial targets.


Populations of a susceptible amphibian species can grow despite the presence of a pathogenic chytrid fungus.
Disease can be an important driver of host population dynamics and epizootics can cause severe host population declines. Batrachochytrium dendrobatidis (Bd), the pathogen causing amphibian chytridiomycosis, may occur epizootically or enzootically and can harm amphibian populations in many ways. While effects of Bd epizootics are well documented, the effects of enzootic Bd have rarely been described. We used a state-space model that accounts for observation error to test whether population trends of a species highly susceptible to Bd, the midwife toad Alytes obstetricans, are negatively affected by the enzootic presence of the pathogen. Unexpectedly, Bd had no negative effect on population growth rates from 2002-2008. This suggests that negative effects of disease on individuals do not necessarily translate into negative effects at the population level. Populations of amphibian species that are susceptible to the emerging disease chytridiomycosis can persist despite the enzootic presence of the pathogen under current environmental conditions.


Increased risk of ischemic stroke in patients with mild traumatic brain injury: a nationwide cohort study.
It is known that the risk of stroke in patients with traumatic brain injury might be increased. However, the relationship between mild traumatic brain injury and ischemic stroke has never been established. We conducted a study of patients in Taiwan with mild traumatic brain injury to evaluate if they had a higher risk of stroke compared with the general population. We utilized a sampled National Health Insurance claims database containing one million beneficiaries. We followed all adult beneficiaries older than 18 years from January 1, 2007 to December 31, 2010 to determine if they were diagnosed with ischemic stroke. We further identified patients with mild traumatic brain injury and compared their risk of ischemic stroke with the general population. We identified 24,905 patients with mild traumatic brain injury and 719,811 patients without mild traumatic brain injury. After controlling for age, gender, urbanization level, socioeconomic status, diabetes, hypertension, coronary artery disease, hyperlipidemia, history of alcohol intoxication, malignancies, heart failure, atrial fibrillation, smoking, obesity, epilepsy, peripheral artery disease and Charlson Comorbidity Index score, the adjusted hazard ratio for ischemic stroke was 1.46 (95% confidence interval, 1.33-1.62). Mild traumatic brain injury is an independent significant risk factor for ischemic stroke.


Target organ disposition and plasma pharmacokinetics of doxorubicin incorporated into albumin microspheres after intrarenal arterial administration.
We synthesized doxorubicin (Adriamycin, Adria Laboratories, Columbus, OH)-loaded human albumin microspheres (containing approximately 1% doxorubicin w/w) between 15 and 20 micron in diameter. Intrarenal arterial administration of 99mTC-labeled microspheres demonstrated a high renal entrapment ratio (97% of recovered radioactivity). The pharmacokinetics and metabolism of doxorubicin are different when it is administered in microspherical form. Peak plasma levels are lower (16 ng/ml versus 135 ng/ml) compared with treatment by a doxorubicin solution. Histologic studies showed that the microspheres were trapped within capillaries and small arterioles in the renal vascular arcade. It is apparent that chemoembolization with doxorubicin-loaded microspheres significantly reduces systemic exposure to the antineoplastic agent, and maintains intrarenal drug levels.


Novel treatment approaches for triple-negative breast cancer.
Triple-negative breast cancers share an aggressive biology, marked by increased recurrence risk and poorer survival compared with hormone receptor-positive subtypes. Few therapeutic trials have specifically focused on triple-negative breast cancer, and the treatment of patients with early-stage triple-negative breast cancer has changed little in the past decade. Over this time, however, attention has shifted to treatment approaches based on molecular subtypes of breast cancer, and investigation into the mechanistic underpinnings of these distinct subtypes has exploded. Converging preclinical rationales combined with early provocative clinical efficacy has focused recent attention on strategies targeting DNA repair defects for the treatment of patients with triple-negative and BRCA mutation-associated breast cancers. These developments are very promising and suggest that major advances in the targeted treatment of patients with triple-negative breast cancer are in sight. This review provides an overview of the clinical features of triple-negative breast cancer and current treatment strategies in the adjuvant setting. Mechanisms of DNA repair and the DNA damage response are reviewed to provide background for understanding novel approaches targeting DNA repair defects in this disease with DNA-damaging chemotherapeutic agents and poly(ADP-ribose) polymerase inhibitors. Ongoing studies, including those investigating the role of antiangiogenic therapies, are also reviewed.


Do clerkship directors think medical students are prepared for the clerkship years?
Educators have begun to question whether medical students are adequately prepared for the core clerkships. Inadequate preclerkship preparation may hinder learning and may be predictive of future achievement. This study assessed and compared the views of clerkship directors regarding student preparation for the core clinical clerkships in six key competencies. In 2002, a national survey was conducted of 190 clerkship directors in internal medicine, family medicine, pediatrics, surgery, obstetrics/gynecology, and psychiatry from 32 U.S. medical schools. Clerkship directors were asked to report their views on the appropriate level of student preparation needed to begin the core clinical clerkships (none, minimal, intermediate, advanced), and the adequacy of that preparation (ranging from "much less" to "much more than necessary") in six key clinical competencies. A total of 140 clerkship directors responded (74%). The majority reported that students need at least intermediate ability in five of six competencies: communication (96%), professionalism (96%), interviewing/physical examination (78%), life-cycle stages (57%), epidemiology/probabilistic thinking (56%), and systems of care (27%). Thirty to fifty percent of clerkship directors felt students are less prepared than necessary in the six competencies. Views were similar across all specialties and generally did not differ by other clerkship director characteristics. Almost half of clerkship directors were concerned that students do not receive adequate preparation in key competencies before starting the core clinical clerkships. Many medical schools may need to give more attention to the preclerkship preparation of students in these high-priority areas.


Exclusive breast-feeding for at least 4 months protects against otitis media.
This study was designed to assess the relation of exclusive breast-feeding, independent of recognized risk factors, to acute and recurrent otitis media in the first 12 months of life. Records of 1220 infants who used a health maintenance organization and who were followed during their first year of life as part of the Tucson Children's Respiratory Study were reviewed. Detailed prospective information about the duration and exclusiveness of breast-feeding was obtained, as was information relative to potential risk factors (socioeconomic status, gender, number of siblings, use of day care, maternal smoking, and family history of allergy). Acute otitis media and recurrent otitis media, defined as three or more episodes of acute otitis media in a 6-month period or four episodes in 12 months, were the outcome variables. Of the 1013 infants followed for their entire first year, 476 (47%) had at least one episode of otitis and 169 (17%) had recurrent otitis media. Infants exclusively breast-fed for 4 or more months had half the mean number of acute otitis media episodes as did those not breastfed at all and 40% less than those infants whose diets were supplemented with other foods prior to 4 months. The recurrent otitis media rate in infants exclusively breast-fed for 6 months or more was 10% and was 20.5% in those infants who breast-fed for less than 4 months. This protection was independent of the risk factors considered. These findings suggest that exclusive breast-feeding of 4 or more months protected infants from single and recurrent episodes of otitis media.


Central venous catheter dress rehearsals: translating simulation training to patient care and outcomes.
Central line-associated blood stream infection (CLABSI) is a preventable burden to our current health care system. Inconsistencies in knowledge and practice of central venous catheters (CVC) dressing change procedures are associated with CLABSI. We hypothesized that participation in a "just-in-time" and "just-in-place" CVC dressing change program would improve nurses' knowledge, confidence, and psychomotor performance on mannequins (eg, T1 outcomes). Moreover, this simulation program would be associated with improved procedural competence on real patients (T2 outcomes) and hospital CLABSI rate (T3 outcomes). We conducted a prospective before and after timed series study at a large urban children's hospital. This program provided an opportunity to practice a CVC dressing change using a simulated patient chest/arm. Cognitive and psychomotor skills were evaluated using a pre-self-assessment/post-self-assessment, written knowledge test and direct observation using a standardized checklist. Central line-associated blood stream infection rates were monitored monthly by the Office of Quality and Patient Safety. Five hundred twenty-four inpatient nurses participated in this program between November 2008 and May 2010. Knowledge and self-confidence improved significantly (knowledge, 4.1 [0.7] vs. 4.6 [0.5], P < 0.001; self-confidence, 4.1 [0.8] vs. 4.6 [0.6], P < 0.001). Of 2469 real-patient CVC dressing changes observed, dress rehearsal trainees required fewer corrective prompts (9% vs. 21%, P < 0.001), and CLABSI rates decreased from 5.3/1000 to 2.9/1000 line days (P < 0.001) during the study. This program improved nurse's knowledge, self-confidence, and psychomotor skill performance on mannequins (eg, T1 outcomes). These improvements were associated with improved procedural competence on real patients (T2 outcomes) and a temporal association with decreased hospital CLABSI rates (T3 outcomes).