Water Dynamics in Shewanella oneidensis at Ambient and High Pressure using Quasi-Elastic Neutron Scattering

Quasielastic neutron scattering (QENS) is an ideal technique for studying water transport and relaxation dynamics at pico-to nanosecond timescales and at length scales relevant to cellular dimensions. Studies of high pressure dynamic effects in live organisms are needed to understand Earth's deep biosphere and biotechnology applications. Here we applied QENS to study water transport in Shewanella oneidensis at ambient (0.1 MPa) and high (200 MPa) pressure using H/D isotopic contrast experiments for normal and perdeuterated bacteria and buffer solutions to distinguish intracellular and transmembrane processes. The results indicate that intracellular water dynamics are comparable with bulk diffusion rates in aqueous fluids at ambient conditions but a significant reduction occurs in high pressure mobility. We interpret this as due to enhanced interactions with macromolecules in the nanoconfined environment. Overall diffusion rates across the cell envelope also occur at similar rates but unexpected narrowing of the QENS signal appears between momentum transfer values Q = 0.7-1.1 Å-1 corresponding to real space dimensions of 6-9 Å. The relaxation time increase can be explained by correlated dynamics of molecules passing through Aquaporin water transport complexes located within the inner or outer membrane structures

Stimulation of tumour growth by wound-derived growth factors

The goal of this work was to determine the molecular basis for the induction of tumour vascularization and progression by injury. Magnetic resonance imaging (MRI) studies demonstrated that administration of wound fluid derived from cutaneous injuries in pigs reduced the lag for vascularization and initiation of growth of C6 glioma spheroids, implanted in nude mice, and accelerated tumour doubling time. The former effect can be attributed to the angiogenic capacity of wound fluid as detected in vivo by MRI, and in vitro in promoting endothelial cell proliferation. The latter effect, namely the induced rate of tumour growth, is consistent with the angiogenic activity of wound fluid as well as with the finding that wound fluid was directly mitogenic to the tumour cells, and accelerated growth of C6 glioma in spheroid culture. Of the multiple growth factors present in wound fluid, two key factors, heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) and platelet-derived growth factor (PDGF), were identified as the dominant mitogens for C6 glioma, and inhibition of their activity using specific neutralizing antibodies suppressed the mitogenic effect of wound fluid on DNA synthesis in C6 glioma. This study suggests that the stimulatory effect of injury on tumour progression can possibly be attenuated by therapeutic targeting directed against a limited number of specific growth factors. © 1999 Cancer Research Campaig

Respiratory and skin health among glass microfiber production workers: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Only a few studies have investigated non-malignant respiratory effects of glass microfibers and these have provided inconsistent results. Our objective was to assess the effects of exposure to glass microfibers on respiratory and skin symptoms, asthma and lung function.</p> <p>Methods</p> <p>A cross-sectional study of 102 workers from a microfiber factory (response rate 100%) and 76 office workers (73%) from four factories in Thailand was conducted. They answered a questionnaire on respiratory health, occupational exposures, and lifestyle factors, and performed spirometry. Measurements of respirable dust were available from 2004 and 2005.</p> <p>Results</p> <p>Workers exposed to glass microfibers experienced increased risk of cough (adjusted OR 2.04), wheezing (adjOR 2.20), breathlessness (adjOR 4.46), nasal (adjOR 2.13) and skin symptoms (adjOR 3.89) and ever asthma (adjOR 3.51), the risks of breathlessness (95%CI 1.68–11.86) and skin symptoms (1.70–8.90) remaining statistically significant after adjustment for confounders. There was an exposure-response relation between the risk of breathlessness and skin symptoms and increasing level of microfiber exposure. Workers exposed to sensitizing chemicals, including phenol-formaldehyde resin, experienced increased risk of cough (3.43, 1.20–9.87) and nasal symptoms (3.07, 1.05–9.00).</p> <p>Conclusion</p> <p>This study provides evidence that exposure to glass microfibers increases the risk of respiratory and skin symptoms, and has an exposure-response relation with breathlessness and skin symptoms. Exposure to sensitizing chemicals increased the risk of cough and nasal symptoms. The results suggest that occupational exposure to glass microfibers is related to non-malignant adverse health effects, and that implementing exposure control measures in these industries could protect the health of employees.</p

Dendritic cells license regulatory B cells to produce IL-10 and mediate suppression of antigen-specific CD8 T cells

Regulatory B cells (Bregs) suppress and reduce autoimmune pathology. However, given the variety of Breg subsets, the role of Bregs in the pathogenesis of type 1 diabetes is still unclear. Here, we dissect this fundamental mechanism. We show that natural protection from type 1 diabetes in nonobese diabetic (NOD) mice is associated with increased numbers of IL-10-producing B cells, while development of type 1 diabetes in NOD mice occurs in animals with compromised IL-10 production by B cells. However, B cells from diabetic mice regain IL-10 function if activated by the innate immune receptor TLR4 and can suppress insulin-specific CD8 T cells in a dendritic cell (DC)-dependent, IL-10-mediated fashion. Suppression of CD8 T cells is reliant on B-cell contact with DCs. This cell contact results in deactivation of DCs, inducing a tolerogenic state, which in turn can regulate pathogenic CD8 T cells. Our findings emphasize the importance of DC–Breg interactions during the development of type 1 diabetes

Consequences of concurrent Ascaridia galli and Escherichia coli infections in chickens

Three experiments were carried out to examine the consequences of concurrent infections with Ascaridia galli and Escherichia coli in chickens raised for table egg production. Characteristic pathological lesions including airsacculitis, peritonitis and/or polyserositis were seen in all groups infected with E. coli. Furthermore, a trend for increased mortality rates was observed in groups infected with both organisms which, however, could not be confirmed statistically. The mean worm burden was significantly lower in combined infection groups compared to groups infected only with A. galli. It was also shown that combined infections of E. coli and A. galli had an added significant negative impact on weight gain

Inflammatory parameters predict etiologic patterns but do not allow for individual prediction of etiology in patients with CAP – Results from the German competence network CAPNETZ

<p>Abstract</p> <p>Background</p> <p>Aim of this study was to evaluate the correlation of inflammatory markers procalcitonin (PCT), C-reactive protein (CRP) and leukocyte count (WBC) with microbiological etiology of CAP.</p> <p>Methods</p> <p>We enrolled 1337 patients (62 ± 18 y, 45% f) with proven CAP. Extensive microbiological workup was performed. In all patients PCT, CRP, WBC and CRB-65 score were determined. Patients were classified according to microbial diagnosis and CRB-65 score.</p> <p>Results</p> <p>In patients with typical bacterial CAP, levels of PCT, CRP and WBC were significantly higher compared to CAP of atypical or viral etiology. There were no significant differences in PCT, CRP and WBC in patients with atypical or viral etiology of CAP. In contrast to CRP and WBC, PCT markedly increased with severity of CAP as measured by CRB-65 score (p < 0.0001). In ROC analysis for discrimination of patients with CRB-65 scores > 1, AUC for PCT was 0.69 (95% CI 0.66 to 0.71), which was higher compared to CRP and WBC (p < 0.0001). CRB-65, PCT, CRP and WBC were higher (p < 0.0001) in hospitalised patients in comparison to outpatients.</p> <p>Conclusion</p> <p>PCT, CRP and WBC are highest in typical bacterial etiology in CAP but do not allow individual prediction of etiology. In contrast to CRP and WBC, PCT is useful in severity assessment of CAP.</p

Detecting Subtle Changes in Visuospatial Executive Function and Learning in the Amnestic Variant of Mild Cognitive Impairment

BACKGROUND AND PURPOSE: Amnestic mild cognitive impairment (aMCI) is a putative prodromal stage of Alzheimer's disease (AD) characterized by deficits in episodic verbal memory. Our goal in the present study was to determine whether executive dysfunction may also be detectable in individuals diagnosed with aMCI. METHODS: This study used a hidden maze learning test to characterize component processes of visuospatial executive function and learning in a sample of 62 individuals with aMCI compared with 94 healthy controls. RESULTS: Relative to controls, individuals with aMCI made more exploratory/learning errors (Cohen's d = .41). Comparison of learning curves revealed that the slope between the first two of five learning trials was four times as steep for controls than for individuals with aMCI (Cohen's d = .64). Individuals with aMCI also made a significantly greater number of rule-break/error monitoring errors across learning trials (Cohen's d = .21). CONCLUSIONS: These results suggest that performance on a task of complex visuospatial executive function is compromised in individuals with aMCI, and likely explained by reductions in initial strategy formulation during early visual learning and "on-line" maintenance of task rules

Texture classification of proteins using support vector machines and bio-inspired metaheuristics

6th International Joint Conference, BIOSTEC 2013, Barcelona, Spain, February 11-14, 2013[Abstract] In this paper, a novel classification method of two-dimensional polyacrylamide gel electrophoresis images is presented. Such a method uses textural features obtained by means of a feature selection process for whose implementation we compare Genetic Algorithms and Particle Swarm Optimization. Then, the selected features, among which the most decisive and representative ones appear to be those related to the second order co-occurrence matrix, are used as inputs for a Support Vector Machine. The accuracy of the proposed method is around 94 %, a statistically better performance than the classification based on the entire feature set. This classification step can be very useful for discarding over-segmented areas after a protein segmentation or identification process

Procalcitonin Predicts Response to Beta-Lactam Treatment in Hospitalized Children with Community-Acquired Pneumonia

BACKGROUND: Antibiotic treatment of community-acquired pneumonia (CAP) in children remains mostly empirical because clinical and paraclinical findings poorly discriminate the principal causes of CAP. Fast response to beta-lactam treatment can be considered a proxy of pneumococcal aetiology. We aimed to identify the best biological predictor of response to beta-lactam therapy in children hospitalized for CAP. METHODS: A retrospective, single-centre cohort study included all consecutive patients 1 month to 16 years old hospitalized in a teaching hospital in Paris, France, because of CAP empirically treated with a beta-lactam alone from 2003 to 2010. Uni- and multivariate analyses were used to study the ability of routine biological parameters available in the Emergency Department to predict a favourable response to beta-lactam (defined as apyrexia within 48 hours of treatment onset). RESULTS: Among the 125 included patients, 85% (106) showed a favourable response to beta-lactam. In multivariate logistic regression, we found procalcitonin (PCT) the only independent predictor of apyrexia (p = 0.008). The adjusted odds ratio for the decadic logarithm of PCT was 4.3 (95% CI 1.5-12.7). At ≥ 3 ng/mL, PCT had 55.7% sensitivity (45.7-65.3), 78.9% specificity (54.4-93.9), 93.7% positive predictive value (84.5-98.2), 24.2% negative predictive value (14.2-36.7), 2.64 positive likelihood ratio (1.09-6.42) and 0.56 negative likelihood ratio (0.41-0.77). In the 4 children with a PCT level ≥ 3 ng/mL and who showed no response to beta-lactam treatment, secondary pleural effusion had developed in 3, and viral co-infection was documented in 1. CONCLUSIONS: PCT is the best independent biologic predictor of favourable response to beta-lactam therapy in children hospitalized for CAP. Thus, a high PCT level is highly suggestive of pneumococcal aetiology. However, a 3-ng/mL cut-off does not seem compatible with daily medical practice, and additional research is needed to further define the role of PCT in managing CAP in children

Risk factors of post renal transplant anaemia among Sudanese patients, a study in three renal transplant centres

<p>Abstract</p> <p>Background</p> <p>There is a relative lack of recent information about late post kidney transplantation anaemia (PTA), especially in the developing countries; data are scarce about the prevalence and risk factors of PTA. Sudan was a leading country in Africa and Arab world in kidney transplantation. The first kidney transplantation in Sudan was in 1973.</p> <p>Methods</p> <p>This is a cross-sectional hospital analytic study enrolling all kidney transplanted recipients following in the transplant referral clinics at Ahmed Gassim, Selma and Ibn Sina Hospitals, Khartoum/Sudan, in the period from 1/8/2010 to 1/9/2010, clinical and laboratory data were obtained from 114 patients, anaemia was defined as Hb levels of < 13 g/dl for male patients and < 12 g/dl for female patients, exclusion criteria were pregnancy, below 18 years old patients, multiple organ transplantation, and patients with less than one year from the transplantation.</p> <p>Results</p> <p>The study showed that 39.5% of the patients were anaemic. Univariate analysis showed that late PTA is significantly associated with not using Erythropoietin (EPO) in the pre-transplant period (p = < 0.001), history of rejection (p = 0.003), longer time from transplantation (p = 0.015), and eGFR (p < 0.0001). Multivariate analysis showed that eGFR (p = < 0.001) and not use of EPO in the pre transplant period (p < 0.001) are strong predictors of PTA. The use of Angiotensin converting enzyme inhibitors/Angiotensin receptors blockers (ACEI/ARB), immunosuppressive treatments, presence or absence of co-morbidities, donor type and donor age are not significantly associated with late PTA.</p> <p>Conclusion</p> <p>The study concluded that late PTA is common and under recognized. Risk factors for late PTA include renal dysfunction, history of rejection, longer duration of transplantation and not using EPO in the pre-transplant period. Renal dysfunction and not using EPO in the pre-transplant period are major predictors of late PTA.</p