Mapping of functionally characterized cell classes onto canonical circuit operations in primate prefrontal cortex.
Microcircuits are composed of multiple cell classes that likely serve unique circuit operations. But how cell classes map onto circuit functions is largely unknown, particularly for primate prefrontal cortex during actual goal-directed behavior. One difficulty in this quest is to reliably distinguish cell classes in extracellular recordings of action potentials. Here we surmount this issue and report that spike shape and neural firing variability provide reliable markers to segregate seven functional classes of prefrontal cells in macaques engaged in an attention task. We delineate an unbiased clustering protocol that identifies four broad spiking (BS) putative pyramidal cell classes and three narrow spiking (NS) putative inhibitory cell classes dissociated by how sparse, bursty, or regular they fire. We speculate that these functional classes map onto canonical circuit functions. First, two BS classes show sparse, bursty firing, and phase synchronize their spiking to 3-7 Hz (theta) and 12-20 Hz (beta) frequency bands of the local field potential (LFP). These properties make cells flexibly responsive to network activation at varying frequencies. Second, one NS and two BS cell classes show regular firing and higher rate with only marginal synchronization preference. These properties are akin to setting tonically the excitation and inhibition balance. Finally, two NS classes fired irregularly and synchronized to either theta or beta LFP fluctuations, tuning them potentially to frequency-specific subnetworks. These results suggest that a limited set of functional cell classes emerges in macaque prefrontal cortex (PFC) during attentional engagement to not only represent information, but to subserve basic circuit operations.


Feasibility of noninvasive single-channel automated differentiation of obstructive and central hypopneas with nasal airflow.
The identification of obstructive and central hypopneas is considered challenging in clinical practice. Presently, obstructive and central hypopneas are usually not differentiated or scores lack reliability due to the technical limitations of standard polysomnography. Esophageal pressure measurement is the gold-standard for identifying these events but its invasiveness deters its usage in daily practice. To determine the feasibility and efficacy of an automatic noninvasive analysis method for the differentiation of obstructive and central hypopneas based solely on a single-channel nasal airflow signal. The obtained results are compared with gold-standard esophageal pressure scores. A total of 41 patients underwent full night polysomnography with systematic esophageal pressure recording. Two experts in sleep medicine independently differentiated hypopneas with the gold-standard esophageal pressure signal. Features were automatically extracted from the nasal airflow signal of each annotated hypopnea to train and test the automatic analysis method. Interscorer agreement between automatic and visual scorers was measured with Cohen's kappa statistic (ĸ). A total of 1,237 hypopneas were visually differentiated. The automatic analysis achieved an interscorer agreement of ĸ = 0.37 and an accuracy of 69% for scorer A, ĸ = 0.40 and 70% for scorer B and ĸ = 0.41 and 71% for the agreed scores of scorers A and B. The promising results obtained in this pilot study demonstrate the feasibility of noninvasive single-channel hypopnea differentiation. Further development of this method may help improving initial diagnosis with home screening devices and offering a means of therapy selection and/or control.


Predicting the short-term risk of diabetes in HIV-positive patients: the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study.
HIV-positive patients receiving combination antiretroviral therapy (cART) frequently experience metabolic complications such as dyslipidemia and insulin resistance, as well as lipodystrophy, increasing the risk of cardiovascular disease (CVD) and diabetes mellitus (DM). Rates of DM and other glucose-associated disorders among HIV-positive patients have been reported to range between 2 and 14%, and in an ageing HIV-positive population, the prevalence of DM is expected to continue to increase. This study aims to develop a model to predict the short-term (six-month) risk of DM in HIV-positive populations and to compare the existing models developed in the general population. All patients recruited to the Data Collection on Adverse events of Anti-HIV Drugs (D:A:D) study with follow-up data, without prior DM, myocardial infarction or other CVD events and with a complete DM risk factor profile were included. Conventional risk factors identified in the general population as well as key HIV-related factors were assessed using Poisson-regression methods. Expected probabilities of DM events were also determined based on the Framingham Offspring Study DM equation. The D:A:D and Framingham equations were then assessed using an internal-external validation process; area under the receiver operating characteristic (AUROC) curve and predicted DM events were determined. Of 33,308 patients, 16,632 (50%) patients were included, with 376 cases of new onset DM during 89,469 person-years (PY). Factors predictive of DM included higher glucose, body mass index (BMI) and triglyceride levels, and older age. Among HIV-related factors, recent CD4 counts of <200 cells/µL and lipodystrophy were predictive of new onset DM. The mean performance of the D:A:D and Framingham equations yielded AUROC of 0.894 (95% CI: 0.849, 0.940) and 0.877 (95% CI: 0.823, 0.932), respectively. The Framingham equation over-predicted DM events compared to D:A:D for lower glucose and lower triglycerides, and for BMI levels below 25 kg/m(2). The D:A:D equation performed well in predicting the short-term onset of DM in the validation dataset and for specific subgroups provided better estimates of DM risk than the Framingham.


BAG-1 expression correlates with Bcl-2, p53, differentiation, estrogen and progesterone receptors in invasive breast carcinoma.
BAG-1, a recently identified anti-apoptotic protein, is overexpressed in the majority of invasive breast carcinomas. Overexpression of BAG-1 is important for both multi-step oncogenesis and resistance of cancer cells to apoptosis induced by DNA-damaging alkylating agents. BAG-1 protein species are localized differentially; nuclear expression may be associated with a shorter disease-free and overall survival in early stage breast cancer, while cytoplasmic expression has been associated with longer survival in non-small cell lung cancer. Growing evidence suggests that Bcl-2 and p53 are also involved in the oncogenesis of breast cancer. Since BAG-1 interacts with Bcl-2 and is upregulated by mutant p53 in vitro, it would be interesting to determine if their expressions are correlated with each other and with other clinical prognostic factors in invasive breast cancer. To address this question we conducted a large scale retrospective study of BAG-1, Bcl-2 and p53 in 185 breast cancer patients. Our study again showed that BAG-1 is overexpressed in the majority of breast cancer patients. In addition, it demonstrated that the expression of BAG-1 correlates with that of Bcl-2, p53, differentiation, estrogen and progesterone receptors. Our clinical study supports the preclinical finding of the interaction between BAG-1 and Bcl-2, p53 and estrogen and progesterone receptors. Further experiments to explore the prognostic and therapeutic role of BAG-1 in breast cancer are warranted.


Arrive: A retrospective registry of Indian patients with venous thromboembolism.
There is lack of substantial Indian data on venous thromboembolism (VTE). The aim of this study was to provide real-world information on patient characteristics, management strategies, clinical outcomes, and temporal trends in VTE. Multicentre retrospective registry involving 549 medical records of patients with confirmed diagnosis of VTE (deep vein thrombosis [DVT] confirmed by Doppler ultrasonography; pulmonary embolism [PE] by computed tomography, pulmonary angiography and/or V/Q scan) from 2006 to 2010 at three Indian tertiary care hospitals. Acute DVT without PE, acute DVT with PE, and PE alone were reported in 64% (352/549), 23% (124/549), and 13% (73/549) patients, respectively. Mean age was 47 (±16) years, and 70% were males. H/o DVT (34%), surgery including orthopedic surgery (28%), trauma (16%), and immobilization >3 days (14%) were the most common risk factors for VTE. Hypertension (25%), diabetes (19%), and neurological disease (other than stroke) (8%) were the most common co-morbidities. Most (94%) were treated with heparin alone (82%) or fondaparinux (2%) for initial anticoagulation; low molecular weight heparin alone (5%) or warfarin/acenocoumarol (76%) for long-term anticoagulation. Anticoagulant treatment was stopped because of bleeding in 2% (9/515) patients. Mortality was 7% among patients diagnosed with VTE during hospital stay versus 1% in those hospitalized with diagnosed VTE. The annual incidence of DVT (±PE) increased from 2006 to 2010. Acute DVT alone was responsible for the substantial burden of VTE in Indian patients. Bleeding was not the limiting factor for anticoagulant treatment in most patients.


Fragile-X syndrome: unique genetics of the heritable unstable element.
The fragile site at Xq27.3 is an unstable microsatellite repeat, p(CCG)n. In fragile-X syndrome pedigrees, this sequence exhibits variable amplification, the length of which correlates with fragile-site expression. There is a direct relationship between increased p(CCG)n copy number and propensity for instability: individuals having large amplifications exhibit somatic variation due to increased instability. The instability of the p(CCG)n repeat, when transmitted through affected pedigrees, explains the unusual segregation patterns of fragile-X phenotype, referred to as the Sherman paradox. All individuals of fragile-X genotype were found (where testing was possible) to have a parent with amplified p(CCG)n repeat, indicating that few, if any, cases of fragile-X syndrome are not familial.


Chloropicrin-induced toxicity in the respiratory system.
Chloropicrin is a volatile and reactive chemical that has been utilized as a warfare agent and a pesticide to fumigate soil against insects, fungi and nematodes. It poses a health risk to humans and animals if inhaled. The main source of chloropicrin exposure is occupational and occurs during its manufacture, transport and fumigation. Chloropicrin is toxic via all routes of exposure but the main route of systemic exposure is inhalation of the ambient air. Thus, the toxicity mainly affects the respiratory system. After a low level exposure, the first sign is irritation of the upper respiratory tract and eyes. Irritation is mediated by the sensory nerve fibers, which coordinate further activation of various protective reflexes. Chloropicrin-induced irritation is generally reversible but can alter airway responsiveness to other inhalation toxicants. Severe exposures cause injuries in the respiratory tract, inflammation, and even life-threatening edema. Much of the chloropicrin-caused symptoms and toxicity in the respiratory system displays similarities with those evoked by chlorine, which is also a breakdown product of chloropicrin. This review summarizes the latest information on chloropicrin with emphasis on the toxicity in the respiratory system. The data indicates that oxidative stress, modification of macromolecules, mutations, dysfunctions of cell organelles and cell death are involved in acute chloropicrin-induced toxicity in the respiratory system.


Simplified fractional Fourier transforms.
The fractional Fourier transform (FRFT) has been used for many years, and it is useful in many applications. Most applications of the FRFT are based on the design of fractional filters (such as removal of chirp noise and the fractional Hilbert transform) or on fractional correlation (such as scaled space-variant pattern recognition). In this study we introduce several types of simplified fractional Fourier transform (SFRFT). Such transforms are all special cases of a linear canonical transform (an affine Fourier transform or an ABCD transform). They have the same capabilities as the original FRFT for design of fractional filters or for fractional correlation. But they are simpler than the original FRFT in terms of digital computation, optical implementation, implementation of gradient-index media, and implementation of radar systems. Our goal is to search for the simplest transform that has the same capabilities as the original FRFT. Thus we discuss not only the formulas and properties of the SFRFT's but also their implementation. Although these SFRFT's usually have no additivity properties, they are useful for the practical applications. They have great potential for replacing the original FRFT's in many applications.


Protective effect of pioglitazone on cardiomyocyte apoptosis in low-dose streptozotocin & high-fat diet-induced type-2 diabetes in rats.
Cardiomyocyte apoptosis is one of the pathologic phenomena associated with diabetes and related conditions including obesity, insulin resistance and hyperlipidaemia. In the present study, the protective effects of pioglitazone on cardiomyocyte apoptosis was evaluated in experimental diabetes induced by low dose of streptozoticin (STZ) combined with high fat diet (HFD) in rats. Male Wistar rats (150-200 g) were injected with low-dose STZ (45 mg/kg, i.v., single dose) and orally fed with a HFD (20 g/day/rat) for a period of 28 days and simultaneously treated with pioglitazone (20 mg/kg/p.o.) for a period of 21 days (from 8 th day to 28 th day). On 29 th day blood was collected, serum separated and used for biochemical parameters. Heart tissue was used for cardiomyocyte apoptosis measurement and also for histopathological examination. Pioglitazone treatment resulted in a decrease in cardiomyocyte apoptosis as revealed by a decrease in cardiac caspase-3, lactate dehydrogenase (LDH) levels and DNA fragmentation, and an increase in Na+K+ATPase levels in diabetic rats. Cardiac histology of diabetic control rats showed dense focal fatty infiltration in the myocardial cells whereas normal architecture with regular morphology and well preserved cytoplasm was observed with pioglitazone treatment. Pioglitazone treatment significantly reduced the heart rate, mean arterial blood pressure, body mass index (BMI) and levels of serum glucose, leptin, insulin, HOMA-IR, total cholesterol (TC) and triglycerides (TGs), apoliproprotein-B glycosylated haemoglobin (HbA1c) levels and atherogenic index, and increased the levels of serum high density lipoprotein cholesterol (HDL-C) and cardiac antioxidant enzymes. The present study results suggest that pioglitazone possesses cardiac anti-apoptotic potential in diabetic rat model and can be further explored for its use for treatment of diabetic cardiomyopathy.


Differential expression of selenoproteins by human skin cells and protection by selenium from UVB-radiation-induced cell death.
The generation of reactive oxygen species has been implicated as part of the mechanism responsible for UVB-radiation-induced skin damage. In mice, evidence suggests that increased dietary selenium intake may protect skin from many of the harmful effects of UVB radiation. We sought to determine the selenoprotein profile of cultured human skin cells and whether selenium supplementation could protect keratinocytes and melanocytes from the lethal effects of UVB radiation. Labelling experiments using [75Se]selenite showed qualitative and quantitative differences in selenoprotein expression by human fibroblasts, keratinocytes and melanocytes. This was most noticeable for thioredoxin reductase (60 kDa) and phospholipid glutathione peroxidase (21 kDa); these proteins were identified by Western blotting. Despite these differences, we found that a 24 h preincubation with sodium selenite or selenomethionine protected both cultured human keratinocytes and melanocytes from UVB-induced cell death. With primary keratinocytes, the greatest reduction in cell death was found with 10 nM sodium selenite (79% cell death reduced to 21.7%; P<0.01) and with 50 nM selenomethionine (79% cell death reduced to 13.2%; P<0.01). Protection could be obtained with concentrations as low as 1 nM with sodium selenite and 10 nM with selenomethionine. When selenium was added after UVB radiation, little protection could be achieved, with cell death only being reduced from 88.5% to about 50% with both compounds. In all of the experiments sodium selenite was more potent than selenomethionine at providing protection from UVB radiation.


The Multiple Faces of Spinocerebellar Ataxia type 2.
Spinocerebellar ataxia type 2 (SCA2) is among the most common forms of autosomal dominant ataxias, accounting for 15% of the total families. Occurrence is higher in specific populations such as the Cuban and Southern Italian. The disease is caused by a CAG expansion in ATXN2 gene, leading to abnormal accumulation of the mutant protein, ataxin-2, in intracellular inclusions. The clinical picture is mainly dominated by cerebellar ataxia, although a number of other neurological signs have been described, ranging from parkinsonism to motor neuron involvement, making the diagnosis frequently challenging for neurologists, particularly when information about the family history is not available. Although the functions of ataxin-2 have not been completely elucidated, the protein is involved in mRNA processing and control of translation. Recently, it has also been shown that the size of the CAG repeat in normal alleles represents a risk factor for ALS, suggesting that ataxin-2 plays a fundamental role in maintenance of neuronal homeostasis.


Uncertainty characterization of particle depth measurement using digital in-line holography and the hybrid method.
In the detection of particles using digital in-line holography, measurement accuracy is substantially influenced by the hologram processing method. In particular, a number of methods have been proposed to determine the out-of-plane particle depth (z location). However, due to the lack of consistent uncertainty characterization, it has been unclear which method is best suited to a given measurement problem. In this work, depth determination accuracies of seven particle detection methods, including a recently proposed hybrid method, are systematically investigated in terms of relative depth measurement errors and uncertainties. Both synthetic and experimental holograms of particle fields are considered at conditions relevant to particle sizing and tracking. While all methods display a range of particle conditions where they are most accurate, in general the hybrid method is shown to be the most robust with depth uncertainty less than twice the particle diameter over a wide range of particle field conditions.


Use of plant growth promoting bacterial strains to improve Cytisus striatus and Lupinus luteus development for potential application in phytoremediation.
Plant growth promoting (PGP) bacterial strains possess different mechanisms to improve plant development under common environmental stresses, and are therefore often used as inoculants in soil phytoremediation processes. The aims of the present work were to study the effects of a collection of plant growth promoting bacterial strains on plant development, antioxidant enzyme activities and nutritional status of Cytisus striatus and/or Lupinus luteus plants a) growing in perlite under non-stress conditions and b) growing in diesel-contaminated soil. For this, two greenhouse experiments were designed. Firstly, C. striatus and L. luteus plants were grown from seeds in perlite, and periodically inoculated with 6 PGP strains, either individually or in pairs. Secondly, L. luteus seedlings were grown in soil samples of the A and B horizons of a Cambisol contaminated with 1.25% (w/w) of diesel and inoculated with best PGP inoculant selected from the first experiment. The results indicated that the PGP strains tested in perlite significantly improved plant growth. Combination treatments provoked better growth of L. luteus than the respective individual strains, while individual inoculation treatments were more effective for C. striatus. L. luteus growth in diesel-contaminated soil was significantly improved in the presence of PGP strains, presenting a 2-fold or higher increase in plant biomass. Inoculants did not provoke significant changes in plant nutritional status, with the exception of a subset of siderophore-producing and P-solubilising bacterial strains that resulted in significantly modification of Fe or P concentrations in leaf tissues. Inoculants did not cause significant changes in enzyme activities in perlite experiments, however they significantly reduced oxidative stress in contaminated soils suggesting an improvement in plant tolerance to diesel. Some strains were applied to non-host plants, indicating a non-specific performance of their plant growth promotion. The use of PGP strains in phytoremediation may help plants to overcome contaminant and other soil stresses, increasing phytoremediation efficiency.


Inpatient hospital care of children with trisomy 13 and trisomy 18 in the United States.
Trisomy 13 and trisomy 18 are generally considered fatal anomalies, with a majority of infants dying in the first year after birth. The inpatient hospital care that these patients receive has not been adequately described. This study characterized inpatient hospitalizations of children with trisomy 13 and trisomy 18 in the United States, including number and types of procedures performed. Retrospective repeated cross-sectional assessment of hospitalization data from the nationally representative US Kids' Inpatient Database, for the years 1997, 2000, 2003, 2006, and 2009. Included hospitalizations were of patients aged 0 to 20 years with a diagnosis of trisomy 13 or trisomy 18. The number of hospitalizations for each trisomy type ranged from 846 to 907 per year for trisomy 13 (P = .77 for temporal trend) and 1036 to 1616 per year for trisomy 18 (P < .001 for temporal trend). Over one-third (36%) of the hospitalizations were of patients older than 1 year of age. Patients underwent a total of 2765 major therapeutic procedures, including creation of esophageal sphincter (6% of hospitalizations; mean age 23 months), repair of atrial and ventricular septal defects (4%; mean age 9 months), and procedures on tendons (4%; mean age 8 years). Children with trisomy 13 and trisomy 18 receive significant inpatient hospital care. Despite the conventional understanding of these syndromes as lethal, a substantial number of children are living longer than 1 year and undergoing medical and surgical procedures as part of their treatment.


Organizational climate in primary care settings: implications for nurse practitioner practice.
The purpose of this review is to investigate literature related to organizational climate, define organizational climate, and identify its domains for nurse practitioner (NP) practice in primary care settings. A search was conducted using MEDLINE, PubMed, HealthSTAR/Ovid, ISI Web of Science, and several other health policy and nursingy databases. In primary care settings, organizational climate for NPs is a set of organizational attributes, which are perceived by NPs about their practice setting, emerge from the way the organization interacts with NPs, and affect NP behaviors and outcomes. Autonomy, NP-physician relations, and professional visibility were identified as organizational climate domains. NPs should be encouraged to assess organizational climate in their workplace and choose organizations that promote autonomy, collegiality between NPs and physicians, and encourage professional visibility. Organizational and NP awareness of qualities that foster NP practice will be a first step for developing strategies to creating an optimal organizational climate for NPs to deliver high-quality care. More research is needed to develop a comprehensive conceptual framework for organizational climate and develop new instruments to accurately measure organizational climate and link it to NP and patient outcomes.


Plasma Krebs Cycle Intermediates in Nonalcoholic Fatty Liver Disease.
Nonalcoholic liver disease (NAFLD) is manifested with a wide spectrum of clinical symptoms and is closely associated with the metabolic syndrome, inflammation, and mitochondrial dysfunction. Although the mechanism of mitochondrial dysfunction in NAFLD is still not fully elucidated, multiple studies have demonstrated evidence of molecular, biochemical, and biophysical mitochondrial abnormalities in NAFLD. Given the association between NAFLD and mitochondrial dysfunction, the aim of this study is to analyze circulating levels of Krebs cycle intermediates in a cohort of NAFLD-affected individuals and matching healthy controls and to correlate our findings with the liver function metrics. Standard serum biochemistry and Krebs cycle intermediates were analyzed in NAFLD (n = 22) and matched control (n = 67) cohorts. Circulating levels of isocitrate and citrate were significantly (p < 0.05) elevated in the NAFLD cohort of patients. The area under the curve (AUROC) for these two metabolites exhibited a moderate clinical utility. Correlations between plasma Krebs cycle intermediates and standard clinical plasma metrics were explored by Pearson's correlation coefficient. The data obtained for plasma Krebs cycle intermediates suggest pathophysiological insights that link mitochondrial dysfunction with NAFLD. Our findings reveal that plasma isocitrate and citrate can discriminate between normal and NAFLD cohorts and can be utilized as noninvasive markers of mitochondrial dysfunction in NAFLD. Future studies with large populations at different NAFLD stages are warranted.


Canine follicle stem cell candidates reside in the bulge and share characteristic features with human bulge cells.
The hair follicle bulge has attracted great interest as a stem cell repository. Previous studies have focused on rodent or human bulge stem cells, and our understanding of those in other species is limited. In this study, we attempted to localize and characterize stem cell candidates in canine hair follicles. The canine skin xenografting study located label-retaining cells in the outer root sheath around the insertion point of the arrector pili muscle, where the immunoreactivity of human bulge markers, keratin 15 and follistatin, were detected. Canine bulge cell-enriched keratinocytes up-regulated human bulge biomarkers CD200 and DIO2, and conserved key cell regulators of bulge stem cells, such as SOX9 and LHX2. Importantly, canine bulge-derived keratinocytes were highly proliferative in vitro and, when combined with trichogenic dermal cells, reconstituted pilosebaceous structures as well as the epidermis in vivo. Successful detection of canine specific DNA sequences suggested that the regenerated tissue was of canine origin. In addition, canine specific bulge cell and sebocyte lineage markers were expressed in reconstituted pilosebaceous units, implying the multipotency of canine bulge cells. Our findings demonstrate a unique strategy utilizing canine bulge cells to investigate human stem cell biology and intractable hair disorders that involve the bulge region.


Dietary Diversity: Implications for Obesity Prevention in Adult Populations: A Science Advisory From the American Heart Association.
"Eat a variety of foods," or dietary diversity, is a widely accepted recommendation to promote a healthy, nutritionally adequate diet and to reduce the risk of major chronic diseases. However, recent evidence from observational studies suggests that greater dietary diversity is associated with suboptimal eating patterns, that is, higher intakes of processed foods, refined grains, and sugar-sweetened beverages and lower intakes of minimally processed foods, such as fish, fruits, and vegetables, and may be associated with weight gain and obesity in adult populations. This American Heart Association science advisory summarizes definitions for dietary diversity and reviews current evidence on its relationship with obesity outcomes, eating behavior, and food-based diet quality measures. Current data do not support greater dietary diversity as an effective strategy to promote healthy eating patterns and healthy body weight. Given the current state of the science on dietary diversity and the insufficient data to inform recommendations on specific aspects of dietary diversity that may be beneficial or detrimental to healthy weight, it is appropriate to promote a healthy eating pattern that emphasizes adequate intake of plant foods, protein sources, low-fat dairy products, vegetable oils, and nuts and limits consumption of sweets, sugar-sweetened beverages, and red meats.


Picosecond infrared laser-induced all-atom nonequilibrium molecular dynamics simulation of dissociation of viruses.
Since the discovery of the plant pathogen tobacco mosaic virus as the first viral entity in the late 1800s, viruses traditionally have been mainly thought of as pathogens for disease-resistances. However, viruses have recently been exploited as nanoplatforms with applications in biomedicine and materials science. To this aim, a large majority of current methods and tools have been developed to improve the physical stability of viral particles, which may be critical to the extreme physical or chemical conditions that viruses may encounter during purification, fabrication processes, storage and use. However, considerably fewer studies are devoted to developing efficient methods to degrade or recycle such enhanced stability biomaterials. With this in mind, we carry out all-atom nonequilibrium molecular dynamics simulation, inspired by the recently developed mid-infrared free-electron laser pulse technology, to dissociate viruses. Adopting the poliovirus as a representative example, we find that the primary step in the dissociation process is due to the strong resonance between the amide I vibrational modes of the virus and the tuned laser frequencies. This process is determined by a balance between the formation and dissociation of the protein shell, reflecting the highly plasticity of the virus. Furthermore, our method should provide a feasible approach to simulate viruses, which is otherwise too expensive for conventional equilibrium all-atom simulations of such very large systems. Our work shows a proof of concept which may open a new, efficient way to cleave or to recycle virus-based materials, provide an extremely valuable tool for elucidating mechanical aspects of viruses, and may well play an important role in future fighting against virus-related diseases.


Association of the FCRL3 gene with rheumatoid arthritis: a further example of population specificity?
Association of a functional promoter polymorphism mapping to the Fc receptor-like 3 (FCRL3) gene has recently been reported and replicated with rheumatoid arthritis (RA) in Japanese populations. The aim of this study was to investigate association of the FCRL3 gene with RA in UK subjects. DNA was available from 1065 patients with RA and 2073 population controls from the UK. Four single nucleotide polymorphism (SNP) markers (FCRL3-169*C/T (fclr3_3, rs7528684), fclr3_4 (rs11264799), fclr3_5 (rs945635), fclr3_6 (rs3761959)) all previously associated with RA in a Japanese population were genotyped in 761 RA samples and 484 controls. In the remaining samples, only the putative disease causal polymorphism, FCRL3-169*C/T, was tested. Genotyping was performed using either the Sequenom MassArray iPlex platform or a 5' Allelic discrimination assay (Taqman, ABI). Extensive linkage disequilibrium was present across the promoter SNPs genotyped (r2 values = 0.60-0.98). Allele frequencies did not differ between RA cases and controls either for the putative disease causal polymorphism (odds ratio FCRL3-169*C allele = 0.97 (0.87-1.07), p = 0.51) or for the other SNPs tested. Similarly, no association was detected with RA using haplotype analysis or when stratification by shared epitope carriage or by presence of rheumatoid factor was undertaken. This study was powered to detect an effect size of 1.24 or greater for the FCRL3-169*C/T functional promoter polymorphism but no evidence for association was detected, suggesting that this gene will not have a substantial effect in determining susceptibility to RA in populations of Northern European descent.


Production of polyclonal antibodies to Batrachochytrium dendrobatidis and their use in an immunoperoxidase test for chytridiomycosis in amphibians.
Polyclonal antibodies were produced for diagnosing chytridiomycosis in amphibians. Two sheep and 4 rabbits were inoculated with homogenized whole culture of Batrachochytrium dendrobatidis in Freund's complete adjuvant or triple adjuvant. Antisera from all animals reacted strongly with all stages of B. dendrobatidis and stained the walls, cytoplasm, rhizoids and zoospores in an indirect immunoperoxidase test. Significant cross-reactivity occurred only with some fungi in the Chytridiomycota, and there are no members of this phylum besides B. dendrobatidis that infect frogs. The immunoperoxidase stain is a useful screening test when combined with recognition of the morphology and infection site of B. dendrobatidis.


Crystal structures of the CusA efflux pump suggest methionine-mediated metal transport.
Gram-negative bacteria, such as Escherichia coli, frequently use tripartite efflux complexes in the resistance-nodulation-cell division (RND) family to expel various toxic compounds from the cell. The efflux system CusCBA is responsible for extruding biocidal Cu(I) and Ag(I) ions. No previous structural information was available for the heavy-metal efflux (HME) subfamily of the RND efflux pumps. Here we describe the crystal structures of the inner-membrane transporter CusA in the absence and presence of bound Cu(I) or Ag(I). These CusA structures provide new structural information about the HME subfamily of RND efflux pumps. The structures suggest that the metal-binding sites, formed by a three-methionine cluster, are located within the cleft region of the periplasmic domain. This cleft is closed in the apo-CusA form but open in the CusA-Cu(I) and CusA-Ag(I) structures, which directly suggests a plausible pathway for ion export. Binding of Cu(I) and Ag(I) triggers significant conformational changes in both the periplasmic and transmembrane domains. The crystal structure indicates that CusA has, in addition to the three-methionine metal-binding site, four methionine pairs-three located in the transmembrane region and one in the periplasmic domain. Genetic analysis and transport assays suggest that CusA is capable of actively picking up metal ions from the cytosol, using these methionine pairs or clusters to bind and export metal ions. These structures suggest a stepwise shuttle mechanism for transport between these sites.


Predictive factors of lamivudine treatment success in an hepatitis B virus-infected pediatric cohort: a 10-year study.
Hepatitis B virus (HBV) infections are responsible for the development of chronic hepatitis in 400 million people worldwide. Currently, no consensus exists as to when treatment should be initiated for pediatric patients. To evaluate the risks and predictive factors of success of lamivudine treatment in children with chronic, active HBV infection. Forty-three children (22 male, median age 9.6 years) chronically infected with HBV and treated between 1998 and 2008 at CHU Ste-Justine (Montreal, Quebec) were included in the present chart review study. Inclusion criteria were detectable hepatitis B surface antigen and hepatitis B e antigen (HBeAg), minimum serum alanine aminotransferase (ALT) level of two times the upper limit of normal and detectable serum HBV DNA for at least three months. Patients received lamivudine for a minimum of six months (median 14 months). Genotyping was performed. Lamivudine treatment was effective in 35% of cases (15 of 43) and overall virological response (during or after treatment) was achieved in 51% of patients. Three patients harboured suspected lamivudine-resistant mutations and five progressed to HBeAg-chronic HBV. Predictive factors for success of treatment were: younger age at beginning of treatment (P=0.05), elevated ALT levels throughout treatment duration (P=0.003) and loss of HBeAg during treatment (P=0.016). Asian origin did not affect treatment success or spontaneous viral control during follow-up. HBV genotype did not influence treatment success. Lamivudine treatment in a carefully selected cohort of HBV patients demonstrated a good rate of success and low incidence of mutation. Younger age at the beginning of treatment and high ALT levels during treatment predicted a positive outcome.


Skin Inflammation Induced by the Synergistic Action of IL-17A, IL-22, Oncostatin M, IL-1{alpha}, and TNF-{alpha} Recapitulates Some Features of Psoriasis.
Keratinocytes play a crucial role in the regulation of skin inflammation, responding to environmental and immune cells stimuli. They produce soluble factors that can act in an autocrine or paracrine manner on immune cells or directly on aggressors. A screening of the activities of 36 cytokines on keratinocyte gene expression identified IL-17A, IL-22, oncostatin M, TNF-alpha, and IL-1alpha as potent cytokines in inducing cutaneous inflammation. These five proinflammatory cytokines synergistically increased production of CXCL8 and beta-defensin 2 (BD2). In addition, ex vivo studies on human skin explants demonstrated upregulation of BD2, S100A7, and CXCL8 expression in response to the same combination of cytokines. In vivo intradermal injection of these five cytokines in mouse increased CXCL1, CXCL2, CXCL3, S100A9, and BD3 expression, associated with neutrophil infiltration. We confirmed and extended this synergistic effect using quantitative real-time PCR analysis and observed increased expression of nine chemokines and 12 antimicrobial peptides. Production of CXCL, CXCL5, and CXCL8 by keratinocytes stimulated in the presence of this cytokine combination was associated with increased neutrophil chemotactic activity. Similarly, high production of BD2, BD3, and S100A7 was associated with an increased antimicrobial activity. Finally, the transcriptional profile observed in this in vitro model of inflammatory keratinocytes correlated with the one of lesional psoriatic skin. Our results demonstrate the important potentiating activities of IL-17A, IL-22, oncostatin M, TNF-alpha, and IL-1alpha on keratinocytes. This is particularly interesting in the context of psoriasis where these cytokines are overexpressed and could synergize to play an important role in upregulation of chemokines and antimicrobial peptides production.


Tissue protein imaging at 1 μm laser spot diameter for high spatial resolution and high imaging speed using transmission geometry MALDI TOF MS.
We have achieved protein imaging mass spectrometry capabilities at sub-cellular spatial resolution and at high acquisition speed by integrating a transmission geometry ion source with time of flight mass spectrometry. The transmission geometry principle allowed us to achieve a 1-μm laser spot diameter on target. A minimal raster step size of the instrument was 2.5 μm. Use of 2,5-dihydroxyacetophenone robotically sprayed on top of a tissue sample as a matrix together with additional sample preparation steps resulted in single pixel mass spectra from mouse cerebellum tissue sections having more than 20 peaks in a range 3-22 kDa. Mass spectrometry images were acquired in a standard step raster microprobe mode at 5 pixels/s and in a continuous raster mode at 40 pixels/s.


Sensory innervation of the external genital tract of female guinea pigs and mice.
The structural and neurochemical characterization of the sensory innervation of the external genitalia of females is poorly known. To immunohistochemically map the sensory innervation of external genitalia and surrounding structures of female guinea pigs and mice. Large-diameter sensory fibers, presumably mechanoreceptors, were identified by their immunoreactivity to neuron-specific enolase (NSE) or vesicular glutamate transporter 1 (VGluT1). Peptidergic sensory fibers, presumably unmyelinated nociceptors, were identified by their immunoreactivity to calcitonin gene-related peptide (CGRP), substance P, or both. Multiple-labelled tissues were examined with high-resolution confocal microscopy. Microscopic identification of sensory endings, including potential nociceptors, characteristic of the external genitalia. Large complex nerve endings immunoreactive for NSE and VGluT1 were abundant in dermal papillae of the clitoris. Each large ending was accompanied by one or two fine fibers immunoreactive for CGRP but neither substance P nor VGluT1. More simple NSE-immunoreactive endings occurred within dermal papillae in non-hairy skin of the labia and anal canal but were rare in pudendal or perineal hairy skin. Fine intra-epithelial fibers immunoreactive for NSE but not CGRP were abundant in hairy skin but rare in non-hairy genital skin and the clitoris. Only fine varicose fibers immunoreactive for both CGRP and substance P occurred in connective tissue underlying the mucosal epithelium of cervix and endometrium. Compared with surrounding tissues, the sensory innervation of the clitoris is highly specialized. The coactivation of nociceptors containing CGRP but not substance P within each mechanoreceptor complex could be the explanation of pain disorders of the external genitalia.


Conversion of C6 and C5 sugars in undetoxified wet exploded bagasse hydrolysates using Scheffersomyces (Pichia) stipitis CBS6054.
Sugarcane bagasse is a potential feedstock for cellulosic ethanol production, rich in both glucan and xylan. This stresses the importance of utilizing both C6 and C5 sugars for conversion into ethanol in order to improve the process economics. During processing of the hydrolysate degradation products such as acetate, 5-hydroxymethylfurfural (HMF) and furfural are formed, which are known to inhibit microbial growth at higher concentrations. In the current study, conversion of both glucose and xylose sugars into ethanol in wet exploded bagasse hydrolysates was investigated without detoxification using Scheffersomyces (Pichia) stipitis CBS6054, a native xylose utilizing yeast strain. The sugar utilization ratio and ethanol yield (Yp/s) ranged from 88-100% and 0.33-0.41 ± 0.02 g/g, respectively, in all the hydrolysates tested. Hydrolysate after wet explosion at 185°C and 6 bar O2, composed of mixed sugars (glucose and xylose) and inhibitors such as acetate, HMF and furfural at concentrations of 3.2 ± 0.1, 0.4 and 0.5 g/l, respectively, exhibited highest cell growth rate of 0.079 g/l/h and an ethanol yield of 0.39 ± 0.02 g/g sugar converted. Scheffersomyces stipitis exhibited prolonged fermentation time on bagasse hydrolysate after wet explosion at 200°C and 6 bar O2 where the inhibitors concentration was further increased. Nonetheless, ethanol was produced up to 18.7 ± 1.1 g/l resulting in a yield of 0.38 ± 0.02 g/g after 82 h of fermentation.


Aerosol and lobar administration of a recombinant adenovirus to individuals with cystic fibrosis. I. Methods, safety, and clinical implications.
Cystic fibrosis (CF), an autosomal recessive disorder resulting from mutations in the cystic fibrosis trans-membrane conductance regulator (CFTR) gene, is the most common lethal genetic illness in the Caucasian population. Gene transfer to airway epithelium, using adenoviruses containing normal CFTR cDNA, leads to transient production of CFTR mRNA and, in some studies, to correction of the airway epithelial ion transport defect caused by dysfunctional CFTR. Inflammatory responses to the adenoviral vector have been reported, particularly at high viral titers. We evaluated the effects of adenovirus-mediated CFTR gene transfer to airway epithelium in 36 subjects with CF (34 individuals, 2 of whom received two separate doses of vector), 20 by lobar instillation and 16 by aerosol administration. Doses ranged from 8 x 10(6) to 2.5 x 10(10) infective units (IU), in 0.5-log increments. After lobar administration of low doses there were occasional reports of cough, low-grade temperature, and myalgias. At the highest lobar dose (2.5 x 10(9) IU) two of three patients had transient myalgias, fever, and increased sputum production with obvious infiltrates on CT scan. After aerosol administration there were no significant systemic symptoms until the 2.5 x 10(10) IU dose, when both patients experienced myalgias and fever that resolved within 24 hr. There were no infiltrates seen on chest CT scans in any of the patients in the aerosol administration group. There were no consistent changes in pulmonary function tests or any significant rise in serum IgG or neutralizing antibodies in patients from either group. Serum, sputum, and nasal cytokines, measured before and after vector administration, showed no correlation with adenoviral dose. Gene transfer to lung cells was inefficient and expression was transient. Cells infected with the vector included mononuclear inflammatory cells as well as cuboidal and columnar epithelial cells. In summary, we found no consistent immune response, no evidence of viral shedding, and no consistent change in pulmonary function in response to adenovirus-mediated CFTR gene transfer. At higher doses there was a mild, nonspecific inflammatory response, as evidenced by fevers and myalgias. Overall, vector administration was tolerated but transfer of CFTR cDNA was inefficient and transgene expression was transient for the doses and method of administration used here.


Lipid profiling of parkin-mutant human skin fibroblasts.
Parkin mutations are a major cause of early-onset Parkinson's disease (PD). The impairment of protein quality control system together with defects in mitochondria and autophagy process are consequences of the lack of parkin, which leads to neurodegeneration. Little is known about the role of lipids in these alterations of cell functions. In the present study, parkin-mutant human skin primary fibroblasts have been considered as cellular model of PD to investigate on possible lipid alterations associated with the lack of parkin protein. Dermal fibroblasts were obtained from two unrelated PD patients with different parkin mutations and their lipid compositions were compared with that of two control fibroblasts. The lipid extracts of fibroblasts have been analyzed by combined matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF/MS) and thin-layer chromatography (TLC). In parallel, we have performed direct MALDI-TOF/MS lipid analyses of intact fibroblasts by skipping lipid extraction steps. Results show that the proportions of some phospholipids and glycosphingolipids were altered in the lipid profiles of parkin-mutant fibroblasts. The detected higher level of gangliosides, phosphatidylinositol, and phosphatidylserine could be linked to dysfunction of autophagy and mitochondrial turnover; in addition, the lysophosphatidylcholine increase could represent the marker of neuroinflammatory state, a well-known component of PD.


Does spatial proximity drive norovirus transmission during outbreaks in hospitals?
To assess the role of spatial proximity, defined as patients sharing bays, in the spread of norovirus during outbreaks in hospitals. Enhanced surveillance of norovirus outbreaks between November 2009 and November 2011. Data were gathered during 149 outbreaks of norovirus in hospital wards from five hospitals in two major cities in England serving a population of two million. We used the time between the first two cases of each outbreak to estimate the serial interval for norovirus in this setting. This distribution and dates of illness onset were used to calculate epidemic trees for each outbreak. We then used a permutation test to assess whether proximity, for all outbreaks, was more extreme than would be expected by chance under the null hypothesis that proximity was not associated with transmission risk. 65 outbreaks contained complete data on both onset dates and ward position. We estimated the serial interval to be 1.86 days (95% CI 1.6 to 2.2 days), and with this value found strong evidence to reject the null hypothesis that proximity was not significant (p<0.001). Sensitivity analysis using different values of the serial interval showed that there was evidence to reject the null hypothesis provided the assumed serial interval was less than 2.5 days. Our results provide evidence that patients occupying the same bay as patients with symptomatic norovirus infection are at an increased risk of becoming infected by these patients compared with patients elsewhere in the same ward.


Method development and validation of almotriptan in human plasma by HPLC tandem mass spectrometry: application to pharmacokinetic study.
A simple, sensitive and selective method has been developed for quantification of Almotriptan (AL) in human plasma using Almotriptan-d(6) (ALD6) as an internal standard. Almotriptan and Almotriptan-d(6) were detected with proton adducts at m/z 336.1→201.1 and 342.2→207.2 in multiple reaction monitoring (MRM) positive mode, respectively. The method was linear over a concentration range of 0.5-150.0 ng/mL. The limit of detection (LOD) and limit of quantification (LOQ) for Almotriptan were 0.2 pg/mL and 0.5 ng/mL, respectively. Liquid-liquid extraction was used followed by MS/MS (ion spray). The method was shown to be precise with an average within-run and between-run variation of 0.68 to 2.78% and 0.57 to 0.86%, respectively. The average within-run and between-run accuracy of the method throughout its linear range was 98.94 to 102.64% and 99.43 to 101.44%, respectively. The mean recovery of drug and internal standard from human plasma was 92.12 ± 4.32% and 89.62 ± 6.32%. It can be applied for clinical and pharmacokinetic studies.


Changes in the electroencephalographic spectrum in response to smoking cues in smokers and ex-smokers.
To investigate the changes in the electroencephalographic (EEG) spectrum in smokers during exposure to a neutral and a smoking-related cue to determine whether these EEG changes are still present in ex-smokers after prolonged abstinence and to examine the relationship between the power in each spectral bandwidth and subjective craving. EEG frequencies in response to a smoking-related and a neutral cue were examined in 23 smokers and 21 ex-smokers, who quit smoking for 1.4 years on average. Additionally, self-report measures of cigarette craving and nicotine dependence were obtained. The spectral power of each bandwidth was computed, log-transformed, and analyzed using a within-subject design. Differences between EEG activity under neutral and smoking conditions were correlated with differences between pre- and postexperimental subjective craving. Increases in reward craving (desire and intention to smoke) were associated with reduced theta activity, whereas increases in withdrawal craving (reduction of negative affect and withdrawal symptoms) were correlated with increases in both delta and higher alpha power. Furthermore, in smokers, but not in ex-smokers, a significant beta power increase was observed between the neutral condition and the smoking condition. Since the beta band is associated with arousal, attention, and alertness, it is suggested that the beta increase in response to the smoking cue might reflect an enhanced allocation of resources to smoking-related stimuli, i.e. a processing bias, which is an important feature of substance abuse. Since ex-smokers do not respond to the smoking cue with beta activity enhancement, we preliminarily conclude that smoking cues do not arouse ex-smokers or capture their attention as much as they do in smokers.


Regulation of cardiac cellular bioenergetics: mechanisms and consequences.
The regulation of cardiac cellular bioenergetics is critical for maintaining normal cell function, yet the nature of this regulation is not fully understood. Different mechanisms have been proposed to explain how mitochondrial ATP production is regulated to match changing cellular energy demand while metabolite concentrations are maintained. We have developed an integrated mathematical model of cardiac cellular bioenergetics, electrophysiology, and mechanics to test whether stimulation of the dehydrogenase flux by Ca(2+) or Pi, or stimulation of complex III by Pi can increase the rate of mitochondrial ATP production above that determined by substrate availability (ADP and Pi). Using the model, we show that, under physiological conditions the rate of mitochondrial ATP production can match varying demand through substrate availability alone; that ATP production rate is not limited by the supply of reducing equivalents in the form of NADH, as a result of Ca(2+) or Pi activation of the dehydrogenases; and that ATP production rate is sensitive to feedback activation of complex III by Pi. We then investigate the mechanistic implications on cytosolic ion homeostasis and force production by simulating the concentrations of cytosolic Ca(2+), Na(+) and K(+), and activity of the key ATPases, SERCA pump, Na(+)/K(+) pump and actin-myosin ATPase, in response to increasing cellular energy demand. We find that feedback regulation of mitochondrial complex III by Pi improves the coupling between energy demand and mitochondrial ATP production and stabilizes cytosolic ADP and Pi concentrations. This subsequently leads to stabilized cytosolic ionic concentrations and consequentially reduced energetic cost from cellular ATPases.


Short-term locomotor adaptation to a robotic ankle exoskeleton does not alter soleus Hoffmann reflex amplitude.
To improve design of robotic lower limb exoskeletons for gait rehabilitation, it is critical to identify neural mechanisms that govern locomotor adaptation to robotic assistance. Previously, we demonstrated soleus muscle recruitment decreased by approximately 35% when walking with a pneumatically-powered ankle exoskeleton providing plantar flexor torque under soleus proportional myoelectric control. Since a substantial portion of soleus activation during walking results from the stretch reflex, increased reflex inhibition is one potential mechanism for reducing soleus recruitment when walking with exoskeleton assistance. This is clinically relevant because many neurologically impaired populations have hyperactive stretch reflexes and training to reduce the reflexes could lead to substantial improvements in their motor ability. The purpose of this study was to quantify soleus Hoffmann (H-) reflex responses during powered versus unpowered walking. We tested soleus H-reflex responses in neurologically intact subjects (n=8) that had trained walking with the soleus controlled robotic ankle exoskeleton. Soleus H-reflex was tested at the mid and late stance while subjects walked with the exoskeleton on the treadmill at 1.25 m/s, first without power (first unpowered), then with power (powered), and finally without power again (second unpowered). We also collected joint kinematics and electromyography. When the robotic plantar flexor torque was provided, subjects walked with lower soleus electromyographic (EMG) activation (27-48%) and had concomitant reductions in H-reflex amplitude (12-24%) compared to the first unpowered condition. The H-reflex amplitude in proportion to the background soleus EMG during powered walking was not significantly different from the two unpowered conditions. These findings suggest that the nervous system does not inhibit the soleus H-reflex in response to short-term adaption to exoskeleton assistance. Future studies should determine if the findings also apply to long-term adaption to the exoskeleton.


Space, stars, c60, and soot.
Although carbon has been subjected to far more study than all other elements put together, the buckminsterfullerene hollow-cage structure, recently proposed to account for the exceptional stability of the C(60) cluster, has shed a totally new and revealing light on several important aspects of carbon's chemical and physical properties that were quite unsuspected and others that were not previously well understood. Most significant is the discovery that C(60) appears to form spontaneously, and this has particularly important implications for particle formation in combustion and in space as well as for the chemistry of polyaromatic compounds. The intriguing revelation that 12 pentagonal "defects" convert a planar hexagonal array of any size into a quasi-icosahedral cage explains why some intrinsically planar materials form quasi-crystalline particles, as appears to occur in the case of soot. Although the novel structural proposal has still to be unequivocally confirmed, this article pays particular attention to the way in which it provides convincing explanations of puzzling observations in several fields, so lending credence to the structure proposed for C(60).


Quantitative autoradiography of major neurotransmitter receptors in the monkey striate and extrastriate cortex.
In vitro autoradiography was used to determine the binding properties and distribution of 9 major neurotransmitter receptors and their subtypes in the striate (area 17 of Brodmann) and extrastriate (areas 18 and 19) cortex of 1 infant and 3 adult rhesus monkeys. Differences in total labeling and nonspecific labeling, as well as Kd and Bmax values, were determined for all cortical layers and sublayers in both cytoarchitectonic areas by Scatchard analysis of autoradiograms. Area 17 differed from area 18 in the laminar pattern and density of virtually every ligand examined, i.e., 3H-clonidine, 3H-prazosin, 125I-iodopindolol, 3H-quinuclidinyl benzilate, 3H-5-hydroxytryptamine, 3H-ketanserin, 3H-muscimol, 3H-flunitrazepam, and 3H-spiperone. Kd and Bmax values for each ligand were remarkably consistent across the 3 adult monkeys analyzed quantitatively. Particularly dramatic contrasts were observed with clonidine, 5-hydroxytryptamine, and ketanserin, which have high affinity for alpha 2-adrenergic, 5-HT1-, and 5-HT2-receptors, respectively. The differences in distribution of these ligands, especially clonidine and 5-hydroxytryptamine, correlated well with specific laminae and hence exhibited distinctly different patterns in areas 17 and 18. Other ligands, such as flunitrazepam and quinuclidinyl benzilate that bind to GABAergic and cholinergic receptors, were visually less discriminating both among layers and between regions. However, layer for layer, the Bmax values for quinuclidinyl benzilate were higher in area 17 than 18, indicating the subtle differences between areas may be revealed only by quantitative measures. Some ligands were particularly dense in layer I (iodopindolol in areas 17 and 18; 5-hydroxytryptamine in area 18), and others subdivided cortical layers that are otherwise cytoarchitectonically uniform (e.g., flunitrazepam and clonidine in layer VI of area 17), indicating that areal differences in ligand binding are not a simple read-out of cell-packing density but most likely reflect a genuine difference related to the neurotransmitters of intrinsic and extrinsic afferents in each area. The presence of binding sites in every layer of both areas for all ligands examined indicates that their distribution across laminae is quantitative and not all-or-none. No layer contained less than 50% of binding sites present in any other layer. These findings reveal that visual cortical areas differ in density and lamination of neurotransmitter receptors and presumably in their sensitivity to circulating levels of endogenous neurotransmitters and pharmacologically active compounds.


Low flow oxygenation of full-excisional skin wounds on diabetic mice improves wound healing by accelerating wound closure and reepithelialization.
Oxygen-based therapies have proven effective in treating chronic and difficult-to-heal skin wounds, but the current therapeutic approaches suffer from major limitations and they do not allow for continuous wound treatment. Here we examined whether the continuous treatment of wounds with pure oxygen at low flow rates accelerates wound closure and improves wound healing in a murine model of diabetic skin wounds. Two full-excisional dorsal skin wounds were generated on 15-week-old diabetic db/db mice and treated for 10 weeks continuously with pure oxygen (>99·9%) at low flow rates (3 ml/h). After 6 days, oxygen treatment resulted in a mean reduction of the original wound size by 60·2% as compared with only 45·2% in wounds on control mice that did not receive pure oxygen.(P = 0·022). After 10 days, oxygen-treated wounds were 83·1% closed compared with 71·2% in wounds on control mice. While reepithelialisation was complete after 10 days in over 57% of wounds receiving low flow oxygen treatment, significant epithelial gaps remained in 75% wounds from mice that did not receive oxygen. Continuous low flow oxygenation significantly improves healing of diabetic skin wounds in mice and may therefore be an effective treatment for chronic cutaneous and possibly other slow-healing wounds in diabetic patients.


Long-Term Results after Percutaneous Closure of Atrial Septal Defect: Cardiac Remodeling and Quality of Life.
Atrial septal defect (ASD) represents a common congenital heart malformation, cause of right ventricle (RV) volume overload, pulmonary hypertension, atrial arrhythmias, and paradoxical emboli. Percutaneous closure represents the treatment of choice for ASD. However, it is still difficult to associate symptoms to the success of ASD treatment. To investigate any possible correlation between transthoracic echocardiography (TTE) findings and patients' symptoms after ASD treatment. Thirty patients (mean age 49 ± 17 years; 10 younger ≤40 years and 20 > 40 years) underwent percutaneous closure of ASD type ostium secundum. Every patient underwent clinical examination, electrocardiogram (ECG) and TTE before procedure and at 1, 6, and 12 months after procedure and a multichoice questionnaire to collect patients' symptoms and complain severity. Continuous variables were summarized by means and standard deviation. Estimates of occurrence of events were expressed as percentages. Comparison between mean follow-ups was achieved using paired t-test sample. At end of follow-up, TTE showed a decrease of RV dimensions (34.4 vs 37.5 mm preclosure; P = 0.01), pulmonary artery systolic pressure (PAPs 28.4 vs 39.5 mmHg; P = 0.00003), atrial dimensions (51 vs 56 mm; P = 0.085), and of right myocardial performance index (MPI; 0.39 vs 0.42; P = 0.05). PAPs was significantly reduced in group more than 40-years-old (P = 0.00004), while the reduction was not significant in the less or equal than 40 years of age (P = 0.08) group because the baseline value was significantly lower. Many patients after procedure complained headache, insomnia, palpitations, fatigue, and dyspnea; but no cardiac morphological abnormalities related to symptoms were found. Our data showed a great improvement in symptoms and positive cardiac remodeling after closure of ASD, more effective in elderly patients compared to younger patients. The symptoms are not correlated with the principal disease or procedure.


Circulating fatty acids and prostate cancer risk: individual participant meta-analysis of prospective studies.
Individual studies have suggested that some circulating fatty acids are associated with prostate cancer risk, but have not been large enough to provide precise estimates of associations, particularly by stage and grade of disease. Principal investigators of prospective studies on circulating fatty acids and prostate cancer were invited to collaborate. Investigators provided individual participant data on circulating fatty acids (weight percent) and other characteristics of prostate cancer cases and controls. Prostate cancer risk by study-specific fifths of 14 fatty acids was estimated using multivariable-adjusted conditional logistic regression. All statistical tests were two-sided. Five thousand and ninety-eight case patients and 6649 control patients from seven studies with an average follow-up of 5.1 (SD = 3.3) years were included. Stearic acid (18:0) was inversely associated with total prostate cancer (odds ratio [OR] Q5 vs Q1 = 0.88, 95% confidence interval [CI] = 0.78 to 1.00, P trend = .043). Prostate cancer risk was, respectively, 14% and 16% greater in the highest fifth of eicosapentaenoic acid (20:5n-3) (OR = 1.14, 95% CI = 1.01 to 1.29, Ptrend = .001) and docosapentaenoic acid (22:5n-3) (OR = 1.16, 95% CI = 1.02 to 1.33, P trend = .003), but in each case there was heterogeneity between studies (P = .022 and P < .001, respectively). There was heterogeneity in the association between docosapentaenoic acid and prostate cancer by grade of disease (P = .006); the association was statistically significant for low-grade disease but not high-grade disease. The remaining 11 fatty acids were not statistically associated with total prostate cancer risk. There was no strong evidence that circulating fatty acids are important predictors of prostate cancer risk. It is not clear whether the modest associations of stearic, eicosapentaenoic, and docosapentaenoic acid are causal.


Base-catalyzed diastereoselective trimerization of trifluoroacetone.
Amphiphilic fluorocarbons have unique properties that facilitate their self assembly and adhesion to both inorganic and biological substrates. Incorporation of these moieties into valuable constructs typically require complex synthetic routes that have limited their use. Here, the base-catalyzed diastereoselective synthesis of 6-methyl-2,4,6-tris(trifluoromethyl)tetrahydro-2H-pyran-2,4-diol is reported. Trimerization of trifluoroacetone in the presence of 5 mol% KHMDS delivers one of four diastereomers selectively in 81% yield with no column chromatography. Temperature screening revealed the reversibility of this trimerization and the funneling of material into the most thermodynamically stable oxane. Subsequent functionalization with boronic acids is reported.


The most common Chinese rhesus macaque MHC class I molecule shares peptide binding repertoire with the HLA-B7 supertype.
Of the two rhesus macaque subspecies used for AIDS studies, the Simian immunodeficiency virus-infected Indian rhesus macaque (Macaca mulatta) is the most established model of HIV infection, providing both insight into pathogenesis and a system for testing novel vaccines. Despite the Chinese rhesus macaque potentially being a more relevant model for AIDS outcomes than the Indian rhesus macaque, the Chinese-origin rhesus macaques have not been well-characterized for their major histocompatibility complex (MHC) composition and function, reducing their greater utilization. In this study, we characterized a total of 50 unique Chinese rhesus macaques from several varying origins for their entire MHC class I allele composition and identified a total of 58 unique complete MHC class I sequences. Only nine of the sequences had been associated with Indian rhesus macaques, and 28/58 (48.3%) of the sequences identified were novel. From all MHC alleles detected, we prioritized Mamu-A1*02201 for functional characterization based on its higher frequency of expression. Upon the development of MHC/peptide binding assays and definition of its associated motif, we revealed that this allele shares peptide binding characteristics with the HLA-B7 supertype, the most frequent supertype in human populations. These studies provide the first functional characterization of an MHC class I molecule in the context of Chinese rhesus macaques and the first instance of HLA-B7 analogy for rhesus macaques.


Defective RNA of a Novel Mycovirus with High Transmissibility Detrimental to Biocontrol Properties of Trichoderma spp.
Trichoderma species are a group of fungi which is widely distributed in major terrestrial ecosystems; they are also commonly used as biocontrol agents for many plant diseases. A virus, namely Trichoderma harzianum hypovirus 1 (ThHV1), was identified in T. harzianum isolate T-70, and also infected isolate T-70D, together with its defective RNA (ThHV1-S). The ThHV1 genome possessed two Open Reading Frames (ORFs), namely ORF1 and ORF2. The start codon of ORF2 overlapped with the stop codon of ORF1 in a 43 nt long region. The polypeptide encoded by ORF2 of ThHV1 shared sequence similarities with those of betahypoviruses, indicating that ThHV1 is a novel member of Hypoviridea. Isolate T-70D, carrying both ThHV1 and ThHV1-S, showed abnormal biological properties, notably a decreased mycoparasitism ability when compared with isolate T-70. Both ThHV1 and ThHV1-S could be vertically transmitted to conidia and horizontally transmitted to T. harzianum isolate T-68 and T. koningiopsis T-51. The derivative strains carrying both ThHV1 and ThHV1-S showed decreased mycoparasitism ability, whereas strains carrying ThHV1 alone were normal, indicating that ThHV1-S is closely associated with the decreased mycoparasitism ability of T. harzianum isolate T-70D. ThHV1 was widely detected in isolates of T. harzianum, T. koningiopsis and T. atroviride originating from soil of China. Therefore, viruses in fungal biocontrol agents may also be a factor associated with the stability of their application.


Administration of visfatin during superovulation improves developmental competency of oocytes and fertility potential in aged female mice.
To examine whether visfatin administration during superovulation improves ovarian response, developmental competence of oocytes, and fertility in aged female mice. Controlled experimental study. University hospital. Two groups of differently aged C57BL female mice (6-11 and 26-31 weeks). Female mice were coinjected intraperitoneally with 5 IU pregnant mare's serum gonadotropin (PMSG) and visfatin of various doses (0-500 ng/mL), followed by 5 IU human chorionic gonadotropin (hCG) injection 48 hours later. Then the mice were immediately mated with an individual male. After 18 hours zygotes were cultured, and expression of ovarian visfatin and vascular endothelial growth factor (VEGF) was examined. Potential pregnancies of visfatin-administered aged female mice were monitored for delivery of offspring. Number of zygotes retrieved, embryo developmental competency, fertility potential, ovarian visfatin and VEGF expression. Ovarian visfatin expression was significantly decreased in the aged mice group compared with the young. Visfatin administration significantly increased embryo developmental rate and ovarian visfatin and VEGF expressions in the aged mice. Visfatin-administered aged mice delivered significantly higher numbers of offspring than controls. This study suggests that visfatin administration during superovulation plays an important role in regulating oocyte quality and can improve oocyte quality and fertility of aged female mice.


Nanodiscs separate chemoreceptor oligomeric states and reveal their signaling properties.
Bacterial chemoreceptors are transmembrane homodimers that can form trimers, higher order arrays, and extended clusters as part of signaling complexes. Interactions of dimers in oligomers are thought to confer cooperativity and cross-receptor influences as well as a 35-fold gain between ligand binding and altered kinase activity. In addition, higher order interactions among dimers are necessary for the observed patterns of assistance in adaptational modification among different receptors. Elucidating mechanisms underlying these properties will require defining which receptor functions can be performed by dimers and which require specific higher order interactions. However, such an assignment has not been possible. Here, we used Nanodiscs, an emerging technology for manipulating membrane proteins, to prepare small particles of lipid bilayer containing one or only a few chemoreceptor dimers. We found that receptor dimers isolated in individual Nanodiscs were readily modified, bound ligand, and performed transmembrane signaling. However, they were hardly able to activate the chemotaxis histidine kinase. Instead, maximal activation and thus full-range control of kinase occurred preferentially in discs containing approximately three chemoreceptor dimers. The sharp dependence of kinase activation on this number of receptors per dimer implies that the core structural unit of kinase activation and control is a trimer of dimers. Thus, our observations demonstrate that chemoreceptor transmembrane signaling does not require oligomeric organization beyond homodimers and implicate a trimer of dimers as the unit of downstream signaling.


Divergent immune responses to house dust mite lead to distinct structural-functional phenotypes.
Asthma is a chronic airway inflammatory disease that encompasses three cardinal processes: T helper (Th) cell type 2 (Th2)-polarized inflammation, bronchial hyperreactivity, and airway wall remodeling. However, the link between the immune-inflammatory phenotype and the structural-functional phenotype remains to be fully defined. The objective of these studies was to evaluate the relationship between the immunologic nature of chronic airway inflammation and the development of abnormal airway structure and function in a mouse model of chronic asthma. Using IL-4-competent and IL-4-deficient mice, we created divergent immune-inflammatory responses to chronic aeroallergen challenge. Immune-inflammatory, structural, and physiological parameters of chronic allergic airway disease were evaluated in both strains of mice. Although both strains developed airway inflammation, the profiles of the immune-inflammatory responses were markedly different: IL-4-competent mice elicited a Th2-polarized response and IL-4-deficient mice developed a Th1-polarized response. Importantly, this chronic Th1-polarized immune response was not associated with airway remodeling or bronchial hyperresponsiveness. Transient reconstitution of IL-4 in IL-4-deficient mice via an airway gene transfer approach led to partial Th2 repolarization and increased bronchial hyperresponsiveness, along with full reconstitution of airway remodeling. These data show that distinct structural-functional phenotypes associated with chronic airway inflammation are strictly dependent on the nature of the immune-inflammatory response.


Cognitive task demands and discourse performance after traumatic brain injury.
Social communication problems are common in adults with traumatic brain injury (TBI), particularly problems in spoken discourse. Social communication problems are thought to reflect underlying cognitive impairments. To measure the contribution of two cognitive processes, executive functioning (EF) and theory of mind (ToM), to the communication of adults with TBI, and to investigate the relationships between discourse performance and potential communication partners' perceptions. Twenty-one adults with moderate-to-severe TBI and 23 uninjured adults completed a discourse task in which EF and ToM demands were manipulated across three conditions: baseline, high-EF and high-ToM. Dependent variables were fluency (for EFs), number of mental state terms (MSTs; for ToM) and speech rate. Discourse from high-EF/ToM conditions was judged by naïve raters for social acceptability. The TBI group produced significantly fewer MSTs than the comparison group across conditions and also spoke at a slower rate, and there were significant effects of condition on both measures (MST: high-EF < baseline = high-ToM; speech rate: high-EF < high-ToM < baseline). There were no significant between-groups differences in fluency or interaction of fluency with condition. MST use and fluency were associated with social acceptability ratings. Results added further evidence of social communication problems in adults with TBI and demonstrated that discourse behaviours may negatively affect how a speaker is perceived. Results also indicated that task manipulations can affect discourse performance, suggesting that general cognitive demands may influence social communication after TBI.


Outcomes from magnetic resonance imaging-confirmed symptomatic cervical disk herniation patients treated with high-velocity, low-amplitude spinal manipulative therapy: a prospective cohort study with 3-month follow-up.
The purpose of this study was to investigate outcomes of patients with cervical radiculopathy from cervical disk herniation (CDH) who are treated with spinal manipulative therapy. Adult Swiss patients with neck pain and dermatomal arm pain; sensory, motor, or reflex changes corresponding to the involved nerve root; and at least 1 positive orthopaedic test for cervical radiculopathy were included. Magnetic resonance imaging-confirmed CDH linked with symptoms was required. Baseline data included 2 pain numeric rating scales (NRSs), for neck and arm, and the Neck Disability Index (NDI). At 2 weeks, 1 month, and 3 months after initial consultation, patients were contacted by telephone, and the NDI, NRSs, and patient's global impression of change data were collected. High-velocity, low-amplitude spinal manipulations were administered by experienced doctors of chiropractic. The proportion of patients responding "better" or "much better" on the patient's global impression of change scale was calculated. Pretreatment and posttreatment NRSs and NDIs were compared using the Wilcoxon test. Acute vs subacute/chronic patients' NRSs and NDIs were compared using the Mann-Whitney U test. Fifty patients were included. At 2 weeks, 55.3% were "improved," 68.9% at 1 month and 85.7% at 3 months. Statistically significant decreases in neck pain, arm pain, and NDI scores were noted at 1 and 3 months compared with baseline scores (P < .0001). Of the subacute/chronic patients, 76.2% were improved at 3 months. Most patients in this study, including subacute/chronic patients, with symptomatic magnetic resonance imaging-confirmed CDH treated with spinal manipulative therapy, reported significant improvement with no adverse events.


The Role of Posterior Parietal Cortex in Beat-based Timing Perception: A Continuous Theta Burst Stimulation Study.
There is growing interest in how the brain's motor systems contribute to the perception of musical rhythms. The Action Simulation for Auditory Prediction hypothesis proposes that the dorsal auditory stream is involved in bidirectional interchange between auditory perception and beat-based prediction in motor planning structures via parietal cortex [Patel, A. D., & Iversen, J. R. The evolutionary neuroscience of musical beat perception: The Action Simulation for Auditory Prediction (ASAP) hypothesis. Frontiers in Systems Neuroscience, 8, 57, 2014]. We used a TMS protocol, continuous theta burst stimulation (cTBS), that is known to down-regulate cortical activity for up to 60 min following stimulation to test for causal contributions to beat-based timing perception. cTBS target areas included the left posterior parietal cortex (lPPC), which is part of the dorsal auditory stream, and the left SMA (lSMA). We hypothesized that down-regulating lPPC would interfere with accurate beat-based perception by disrupting the dorsal auditory stream. We hypothesized that we would induce no interference to absolute timing ability. We predicted that down-regulating lSMA, which is not part of the dorsal auditory stream but has been implicated in internally timed movements, would also interfere with accurate beat-based timing perception. We show ( n = 25) that cTBS down-regulation of lPPC does interfere with beat-based timing ability, but only the ability to detect shifts in beat phase, not changes in tempo. Down-regulation of lSMA, in contrast, did not interfere with beat-based timing. As expected, absolute interval timing ability was not impacted by the down-regulation of lPPC or lSMA. These results support that the dorsal auditory stream plays an essential role in accurate phase perception in beat-based timing. We find no evidence of an essential role of parietal cortex or SMA in interval timing.


Retaliatory attitudes as mediator of exposure to violence and firearm aggression among youth: The protective role of organized activity involvement.
Firearm injury is a significant public health concern among youth living in the United States. Youth with exposure to violence (ETV) are more susceptible to carrying and using a firearm. Few researchers, however, have examined psychological mechanisms undergirding the association between ETV and firearm aggression. Retaliatory attitudes have been discussed as a potential mediator linking ETV with firearm aggression. Moreover, organized activity participation may disrupt direct and indirect pathways connecting ETV to firearm aggression. We tested: (a) the mediating role of retaliatory attitudes in the ETV-firearm aggression link, and (b) the moderating role of organized activity participation among 570 youth with past year illicit drug use and seeking emerging department care in an urban emergency department (ages 14-24; 58.8% males). Using multigroup path analysis, ETV indirectly influenced firearm aggression through retaliatory attitudes for youth not involved organized activities. Organized activities also buffered the association between retaliatory attitudes (mediator) and firearm aggression (outcome). Organized activities may, therefore, prevent firearm aggression by reducing retaliatory attitudes among youth contending with ETV. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


The Pancreatitis Activity Scoring System predicts clinical outcomes in acute pancreatitis: findings from a prospective cohort study.
The Pancreatitis Activity Scoring System (PASS) has been derived by an international group of experts via a modified Delphi process. Our aim was to perform an external validation study to assess for concordance of the PASS score with high face validity clinical outcomes and determine specific meaningful thresholds to assist in application of this scoring system in a large prospectively ascertained cohort. We analyzed data from a prospective cohort study of consecutive patients admitted to the Los Angeles County Hospital between March 2015 and March 2017. Patients were identified using an emergency department paging system and electronic alert system. Comprehensive characterization included substance use history, pancreatitis etiology, biochemical profile, and detailed clinical course. We calculated the PASS score at admission, discharge, and at 12 h increments during the hospitalization. We performed several analyses to assess the relationship between the PASS score and outcomes at various points during hospitalization as well as following discharge. Using multivariable logistic regression analysis, we assessed the relationship between admission PASS score and risk of severe pancreatitis. PASS score performance was compared to established systems used to predict severe pancreatitis. Additional inpatient outcomes assessed included local complications, length of stay, development of systemic inflammatory response syndrome (SIRS), and intensive care unit (ICU) admission. We also assessed whether the PASS score at discharge was associated with early readmission (re-hospitalization for pancreatitis symptoms and complications within 30 days of discharge). A total of 439 patients were enrolled, their mean age was 42 (±15) years, and 53% were male. Admission PASS score >140 was associated with moderately severe and severe pancreatitis (OR 3.5 [95% CI 2.0, 6.3]), ICU admission (OR 4.9 [2.5, 9.4]), local complications (3.0 [1.6, 5.7]), and development of SIRS (OR 2.9 [1.8, 4.5]) as well as prolongation of hospitalization by a mean of 1.5 (1.3-1.7) days. For the prediction of moderately severe/severe pancreatitis, the PASS score (AUC = 0.71) was comparable to the more established Ranson's (AUC = 0.63), Glasgow (AUC = 0.72), Panc3 (AUC = 0.57), and HAPS (AUC = 0.54) scoring systems. Discharge PASS score >60 was associated with early readmission (OR 5.0 [2.4, 10.7]). The PASS score is associated with important clinical outcomes in acute pancreatitis. The ability of the score to forecast important clinical events at different points in the disease course suggests that it is a valid measure of activity in patients with acute pancreatitis.


Kynanthropy: canine madness in Byzantine late antiquity.
Those afflicted bark like dogs, scramble on all fours and loiter around graveyards - canine madness, referred to as kynanthropy, was an illness concept in its own right in the medicine of late antiquity. At roughly the same time as the medical description produced by Aëtius of Amida, the Syrian chronicler John of Ephesus, also from Amida, reported an epidemic of dog-like madness sweeping his home town in ad 560. The symptoms are identical and both authors are from Amida - what is the connection between the two depictions? In addition to the history of the medical concept, the example of the canine madness of Amida and its cultural embedding allows us to contextualize and interpret the significance of dog-like behaviour for the people of the sixth century AD.


Rapid transcriptome and proteome profiling of a non-model marine invertebrate, Bugula neritina.
Non-model organisms represent the majority of life forms in our planet. However, the lack of genetic information hinders us to understand the unique biological phenomena in non-model organisms at the molecular level. In this study, we applied a tandem transcriptome and proteome profiling on a non-model marine fouling organism, Bugula neritina. Using a 454 pyrosequencing platform with the updated titanium reagents, we generated a total of 48M bp transcriptome data consisting of 131 450 high-quality reads. Of these, 122 650 reads (93%) were assembled to produce 6392 contigs with an average length of 538 bases and the remaining 8800 reads were singletons. Of the total 15 192 unigenes, 13 863 ORFs were predicated, of which 6917 were functionally annotated based on gene ontology and eukaryotic orthologous groups. Subsequent proteome analysis identified and quantified 882 proteins from B. neritina. These results would provide fundamental and important information for the subsequent studies of molecular mechanism in larval biology, development, antifouling research. Furthermore, we demonstrated, for the first time, the combined use of two high-throughput technologies as a powerful approach for accelerating the studies of non-model but otherwise important species.


Population pharmacokinetic model for topotecan derived from phase I clinical trials.
To characterize the pharmacokinetics of topotecan in a population model that would identify patient variables or covariates that appreciably impacted on its disposition. All data were collected from 82 patients entered in four different phase I trials that were previously reported as separate studies from 1992 to 1996. All patients received topotecan as a 30-minute constant-rate infusion on a daily-times-five schedule and were selected for this study because their daily dose did not exceed 2.0 mg/m(2). Among the 82 patients were 30 patients classified as having renal insufficiency and 13 patients with hepatic dysfunction. The population pharmacokinetic model was built in sequential manner, starting with a covariate-free model and progressing to a covariate model with the aid of generalized additive modeling. A linear two-compartment model characterized total topotecan plasma concentrations (n = 899). Four primary pharmacokinetic parameters (total clearance, volume of the central compartment, distributional clearance, and volume of the peripheral compartment) were related to various combinations of covariates. The relationship for total clearance (TVCL [L/h] = 32.0 + [0.356(WT - 71) + 0.308(HT - 168.5) - 8.42(SCR - 1.1)] x [1 + 0.671 sex]) was dependent on the patients' weight (WT), height (HT), serum creatinine (SCR), and sex and had a moderate ability to predict (r(2) = 0.64) each patient's individual clearance value. The addition of covariates to the population model improved the prediction errors, particularly for clearance. Removal of 10 outlying patients from the analysis improved the ability of the model to predict individual clearance values (r(2) = 0.77). A population pharmacokinetic model for total topotecan has been developed that incorporates measures of body size and renal function to predict total clearance. The model can be used prospectively to obtain a revised and validated model that can then be used to design individualized dosing regimens.


Two new species of the genus Xenotoca Hubbs and Turner, 1939 (Teleostei, Goodeidae) from central-western Mexico.
The subfamily Goodeinae (Goodeidae) is one of the most representative and well-studied group of fishes from central Mexico, with around 18 genera and 40 species. Recent phylogenetic studies have documented a high degree of genetic diversity and divergences among populations, suggesting that the diversity of the group may be underestimated. The species Xenotoca eiseni has had several taxonomic changes since its description. Xenotoca eiseni is considered a widespread species along the Central Pacific Coastal drainages of Mexico, inhabiting six independent drainages. Recent molecular phylogenetic studies suggest that X. eiseni is a species complex, represented by at least three independent evolutionary lineages. We carried out a meristic and morphometric study in order to evaluate the morphological differences among these genetically divergent populations and describe two new species. The new species of goodeines, Xenotoca doadrioi and X. lyonsi, are described from the Etzatlan endorheic drainage and upper Coahuayana basin respectively.


Quantitative measurement and control of oxygen levels in microfluidic poly(dimethylsiloxane) bioreactors during cell culture.
Microfluidic bioreactors fabricated from highly gas-permeable poly(dimethylsiloxane) (PDMS) materials have been observed, somewhat unexpectedly, to give rise to heterogeneous long term responses along the length of a perfused mammalian cell culture channel, reminiscent of physiologic tissue zonation that arises at least in part due to oxygen gradients. To develop a more quantitative understanding and enable better control of the physical-chemical mechanisms underlying cell biological events in such PDMS reactors, dissolved oxygen concentrations in the channel system were quantified in real time using fluorescence intensity and lifetime imaging of an oxygen sensitive dye, ruthenium tris(2,2'-dipyridyl) dichloride hexahydrate (RTDP). The data indicate that despite oxygen diffusion through PDMS, uptake of oxygen by cells inside the perfused PDMS microchannels induces an axial oxygen concentration gradient, with lower levels recorded in downstream regions. The oxygen concentration gradient generated by a balance of cellular uptake, convective transport by media flow, and permeation through PDMS in our devices ranged from 0.0003 (mg/l)/mm to 0.7 (mg/l)/mm. The existence of such steep gradients induced by cellular uptake can have important biological consequences. Results are consistent with our mathematical model and give insight into the conditions under which flux of oxygen through PDMS into the microchannels will or will not contribute significantly to oxygen delivery to cells and also provide a design tool to manipulate and control oxygen for cell culture and device engineering. The combination of computerized microfluidics, in situ oxygen sensing, and mathematical models opens new windows for microphysiologic studies utilizing oxygen gradients and low oxygen tensions.


Protein secretion by Gram-negative bacterial ABC exporters--a review.
One of the strategies used by Gram-negative bacteria to secrete proteins across the two membranes which delimit the cells is sec-independent and dedicated to proteins lacking an N-terminal signal peptide. Most of these proteins display a C-terminal secretion signal located in the last 60 amino acids (aa). Using one Erwinia chrysanthemi protease, PrtG, secreted by such a pathway it was shown that the smallest C-terminal sequence allowing efficient secretion contains the last 29 aa of PrtG and that low but significant secretion can be promoted by the last 15 aa of PrtG. Moreover, the extreme C-terminal motif, consisting of a negatively charged aa followed by several hydrophobic aa must be exposed and is conserved amongst many proteins following this pathway. This secretion system depends on ABC protein-mediated exporters, which consist of three cell envelope proteins: two inner membrane proteins, an ATPase (the ABC protein), a membrane fusion protein (MFP) and an outer membrane polypeptide. These Gram-negative bacterial protein exporters are dedicated to the secretion of one or several closely related proteins belonging to the toxin, protease and lipase families. The genes encoding the three secretion proteins and the exoproteins are usually all linked, consistent with the specificity of the systems. Er. chrysanthemi metalloproteases B and C and Serratia marcescens hemoprotein HasA are secreted by such homologous pathways and interact with the ABC protein. Interaction between the ABC protein and its substrate has also been evidenced by studies on protease and HasA hybrid transporters obtained by combining components from each system. Association between hemoprotein HasA and the three exporter secretion proteins was demonstrated by affinity chromatography on hemin agarose on which the substrate remained bound with the three secretion proteins. The three components' association was ordered and substrate binding was required for the formation of this multiprotein complex.


Marine invertebrates as models for aging research.
The oceans are home to many of the earth's longest lived animals with several species of non-colonial marine invertebrates documented to live for more than 100 years. Many of these animals grow and reproduce throughout their lifespans and there is no apparent functional decline or increase in mortality rate with age. Studying these animals may reveal some exceptionally effective defenses against the destructive process of aging thus providing a valuable alternative model for aging research. The life histories of commercially important marine invertebrates are well studied, but little is known of the molecular or cellular changes that occur with increasing age or the factors that determine lifespan. The objectives of this review are to present data on cellular and molecular aspects of aging in marine invertebrates with a focus on bivalves and sea urchins. This review will serve to evaluate their potential as model systems for aging and provide direction for future research efforts so that we can begin to understand the underlying molecular mechanisms responsible for the tremendous longevity and good health of key species.


The neuroethology of cognitive maps: contributions from research on the hippocampus and homing pigeon navigation.
The rich ethological tradition that characterizes the homing behavior of pigeons offers an excellent opportunity to examine the importance of the hippocampal formation for the regulation of spatial cognitive mechanisms. The present review summarizes both anatomical and behavioral data obtained in researches on the pigeon hippocampal formation that have been performed over the last 12 years. Pathway connection studies and investigations on the neurochemical organization of the avian hippocampal formation show that this structure shares many similarities with the mammalian hippocampus and provide the basis for structural as well as functional homology. The initial research on the role of the hippocampal formation in the homing behavior showed that this brain structure is likely to be involved in phenomena of spatial cognition. Therefore, the homing behavior of pigeons has been extensively used as an experimental model to investigate the role of the hippocampal formation in spatial cognition related to a naturally occurring behavior. These studies have revealed that the hippocampal formation plays a fundamental role in the learning of a navigational map based on atmospheric odors, but it doesn't seem to be involved in the operation of such a map. In contrast, both the learning and the operation of a navigational map based on the recognition of familiar landmarks require a functional hippocampal formation. Further investigations indicated that these functions of the hippocampal formation are mediated by its involvement in the use of the sun compass, and suggested that the hippocampal formation plays a fundamental role in a cognitive process in which the sun compass is specifically used to learn about the location of stimuli in space. The studies reviewed in the present paper have provided a considerable amount of experimental data both on the anatomical/neurochemical organization of the avian hippocampal formation and on the role played by this brain structure in spatial cognition. The future development of these researches will need to consider the contribution to hippocampal function of specific transmitter systems that are involved in hippocampal circuitry. In particular, the afferent cholinergic system and some of the peptidergic systems intrinsic to the hippocampal formation deserve particular attention in view of their possible involvement in the acquisition and/or operation of spatial cognitive abilities by homing pigeons.


Structural Insights into the Broad-Spectrum Antiviral Target Endoplasmic Reticulum Alpha-Glucosidase II.
Targeting the host-cell endoplasmic reticulum quality control (ERQC) pathway is an effective broad-spectrum antiviral strategy. The two ER resident α-glucosidases whose sequential action permits entry in this pathway are the targets of glucomimetic inhibitors. Knowledge of the molecular details of the ER α-glucosidase II (α-Glu II) structure was limited. We determined crystal structures of a trypsinolytic fragment of murine α-Glu II, alone and in complex with key catalytic cycle ligands, and four different broad-spectrum antiviral iminosugar inhibitors, two of which are currently in clinical trials against dengue fever. The structures highlight novel portions of the enzyme outside its catalytic pocket which contribute to its activity and substrate specificity. These crystal structures and hydrogen-deuterium exchange mass spectrometry of the murine ER alpha glucosidase II heterodimer uncover the quaternary arrangement of the enzyme's α- and β-subunits, and suggest a conformational rearrangement of ER α-Glu II upon association of the enzyme with client glycoproteins.