339 research outputs found
The Relationship of Urinary Metabolites of Carbaryl/Naphthalene and Chlorpyrifos with Human Semen Quality
Most of the general population is exposed to carbaryl and other contemporary-use insecticides at low levels. Studies of laboratory animals, in addition to limited human data, show an association between carbaryl exposure and decreased semen quality. In the present study we explored whether environmental exposures to 1-naphthol (1N), a metabolite of carbaryl and naphthalene, and 3,5,6-trichloro-2-pyridinol (TCPY), a metabolite of chlorpyrifos and chlorpyrifos-methyl, are associated with decreased semen quality in humans. Subjects (n = 272) were recruited through a Massachusetts infertility clinic. Individual exposures were measured as spot urinary concentrations of 1N and TCPY adjusted using specific gravity. Semen quality was assessed as sperm concentration, percent motile sperm, and percent sperm with normal morphology, along with sperm motion parameters (straight-line velocity, curvilinear velocity, and linearity). Median TCPY and 1N concentrations were 3.22 and 3.19 μg/L, respectively. For increasing 1N tertiles, adjusted odds ratios (ORs) were significantly elevated for below-reference sperm concentration (OR for low, medium, and high tertiles = 1.0, 4.2, 4.2, respectively; p-value for trend = 0.01) and percent motile sperm (1.0, 2.5, 2.4; p-value for trend = 0.01). The sperm motion parameter most strongly associated with 1N was straight-line velocity. There were suggestive, borderline-significant associations for TCPY with sperm concentration and motility, whereas sperm morphology was weakly and nonsignificantly associated with both TCPY and 1N. The observed associations between altered semen quality and 1N are consistent with previous studies of carbaryl exposure, although suggestive associations with TCPY are difficult to interpret because human and animal data are currently limited
Mutations in TRAPPC11 are associated with a congenital disorder of glycosylation.
Congenital disorders of glycosylation (CDG) are a heterogeneous and rapidly growing group of diseases caused by abnormal glycosylation of proteins and/or lipids. Mutations in genes involved in the homeostasis of the endoplasmic reticulum (ER), the Golgi apparatus (GA), and the vesicular trafficking from the ER to the ER-Golgi intermediate compartment (ERGIC) have been found to be associated with CDG. Here, we report a patient with defects in both N- and O-glycosylation combined with a delayed vesicular transport in the GA due to mutations in TRAPPC11, a subunit of the TRAPPIII complex. TRAPPIII is implicated in the anterograde transport from the ER to the ERGIC as well as in the vesicle export from the GA. This report expands the spectrum of genetic alterations associated with CDG, providing new insights for the diagnosis and the understanding of the physiopathological mechanisms underlying glycosylation disorders
Sequential application of hyperspectral indices for delineation of stripe rust infection and nitrogen deficiency in wheat
© 2015, Springer Science+Business Media New York. Nitrogen (N) fertilization is crucial for the growth and development of wheat crops, and yet increased use of N can also result in increased stripe rust severity. Stripe rust infection and N deficiency both cause changes in foliar physiological activity and reduction in plant pigments that result in chlorosis. Furthermore, stripe rust produce pustules on the leaf surface which similar to chlorotic regions have a yellow color. Quantifying the severity of each factor is critical for adopting appropriate management practices. Eleven widely-used vegetation indices, based on mathematic combinations of narrow-band optical reflectance measurements in the visible/near infrared wavelength range were evaluated for their ability to discriminate and quantify stripe rust severity and N deficiency in a rust-susceptible wheat variety (H45) under varying conditions of nitrogen status. The physiological reflectance index (PhRI) and leaf and canopy chlorophyll index (LCCI) provided the strongest correlation with levels of rust infection and N-deficiency, respectively. When PhRI and LCCI were used in a sequence, both N deficiency and rust infection levels were correctly classified in 82.5 and 55 % of the plots at Zadoks growth stage 47 and 75, respectively. In misclassified plots, an overestimation of N deficiency was accompanied by an underestimation of the rust infection level or vice versa. In 18 % of the plots, there was a tendency to underestimate the severity of stripe rust infection even though the N-deficiency level was correctly predicted. The contrasting responses of the PhRI and LCCI to stripe rust infection and N deficiency, respectively, and the relative insensitivity of these indices to the other parameter makes their use in combination suitable for quantifying levels of stripe rust infection and N deficiency in wheat crops under field conditions
Objective vs. Self-Reported Physical Activity and Sedentary Time: Effects of Measurement Method on Relationships with Risk Biomarkers
<p><b>Purpose:</b> Imprecise measurement of physical activity variables might attenuate estimates of the beneficial effects of activity on health-related outcomes. We aimed to compare the cardiometabolic risk factor dose-response relationships for physical activity and sedentary behaviour between accelerometer- and questionnaire-based activity measures.</p>
<p><b>Methods:</b> Physical activity and sedentary behaviour were assessed in 317 adults by 7-day accelerometry and International Physical Activity Questionnaire (IPAQ). Fasting blood was taken to determine insulin, glucose, triglyceride and total, LDL and HDL cholesterol concentrations and homeostasis model-estimated insulin resistance (HOMAIR). Waist circumference, BMI, body fat percentage and blood pressure were also measured.</p>
<p><b>Results:</b> For both accelerometer-derived sedentary time (<100 counts.min−1) and IPAQ-reported sitting time significant positive (negative for HDL cholesterol) relationships were observed with all measured risk factors – i.e. increased sedentary behaviour was associated with increased risk (all p≤0.01). However, for HOMAIR and insulin the regression coefficients were >50% lower for the IPAQ-reported compared to the accelerometer-derived measure (p<0.0001 for both interactions). The relationships for moderate-to-vigorous physical activity (MVPA) and risk factors were less strong than those observed for sedentary behaviours, but significant negative relationships were observed for both accelerometer and IPAQ MVPA measures with glucose, and insulin and HOMAIR values (all p<0.05). For accelerometer-derived MVPA only, additional negative relationships were seen with triglyceride, total cholesterol and LDL cholesterol concentrations, BMI, waist circumference and percentage body fat, and a positive relationship was evident with HDL cholesterol (p = 0.0002). Regression coefficients for HOMAIR, insulin and triglyceride were 43–50% lower for the IPAQ-reported compared to the accelerometer-derived MVPA measure (all p≤0.01).</p>
<p><b>Conclusion:</b> Using the IPAQ to determine sitting time and MVPA reveals some, but not all, relationships between these activity measures and metabolic and vascular disease risk factors. Using this self-report method to quantify activity can therefore underestimate the strength of some relationships with risk factors.</p>
Prevalence of Helicobacter pylori infection and associated factors among adults in Southern Brazil: a population-based cross-sectional study
BACKGROUND: Helicobacter pylori (Hp) infection is associated with several upper gastrointestinal disorders. Local data on the epidemiology of the infection are scarce in Brazil. The purpose of this study is to measure the prevalence rate and to explore the associated factors among the adult population living in Pelotas, a southern Brazilin city. METHODS: This was a population-based cross-sectional study. Through a multi-stage sampling method all individuals 20 years and over living at the selected households at the urban area of the city were interviewed regarding past and current socio-economic indicators; demographic characteristics; nutritional and behavioural habits; and history of upper gastrointestinal symptoms.Hp infection was ascertained through the (13)C-UBT. Due to the high prevalence, data were analysed through robust Poisson regression. All analyses took into account the family clustering of the data. RESULTS: Among 563 eligible individuals, 363 agreed to perform the (13)C-UBT (refusal rate of 35.5%). Refusals were associated with female sex, consumption of mate drinking, and presence of upper gastrointestinal symptoms. The prevalence rate of H. pylori infection was 63.4% (95%CI 59.3%–69.3%). In crude analyses, prevalence was associated with increasing age, non-white skin colour, lower current family income, lower education level, higher size of the family, low socio-economic conditions in childhood, higher number of siblings and attendance to day-care centres in childhood, and presence of dyspeptic symptoms. In adjusted analysis the level of education of the father was inversely associated with the infection, whereas number of siblings and attendance to day-care centre in childhood were directly associated with it. Non-white skin colour remained significantly associated with increased prevalence even after allowing for past and current socio-economic characteristics, age and sex. Compared to non-symptomatic individuals, those reporting dyspeptic symptoms presented a higher prevalence of the infection even after allowing for current and past socio-economic conditions, ethnicity, age, and sex. CONCLUSION: Hp infection is as common among adults in southern Brazil as it is in other developing countries. Socio-economic conditions in childhood besides ethnicity and presence of dyspeptic symptoms were the factors significantly associated with the infection
SoftPanel: a website for grouping diseases and related disorders for generation of customized panels
Small intestinal mucosa expression of putative chaperone fls485
<p>Abstract</p> <p>Background</p> <p>Maturation of enterocytes along the small intestinal crypt-villus axis is associated with significant changes in gene expression profiles. <it>fls485 </it>coding a putative chaperone protein has been recently suggested as a gene involved in this process. The aim of the present study was to analyze <it>fls48</it>5 expression in human small intestinal mucosa.</p> <p>Methods</p> <p><it>fls485 </it>expression in purified normal or intestinal mucosa affected with celiac disease was investigated with a molecular approach including qRT-PCR, Western blotting, and expression strategies. Molecular data were corroborated with several <it>in situ </it>techniques and usage of newly synthesized mouse monoclonal antibodies.</p> <p>Results</p> <p>fls485 mRNA expression was preferentially found in enterocytes and chromaffine cells of human intestinal mucosa as well as in several cell lines including Rko, Lovo, and CaCo2 cells. Western blot analysis with our new anti-fls485 antibodies revealed at least two fls485 proteins. In a functional CaCo2 model, an increase in fls485 expression was paralleled by cellular maturation stage. Immunohistochemistry demonstrated fls485 as a cytosolic protein with a slightly increasing expression gradient along the crypt-villus axis which was impaired in celiac disease Marsh IIIa-c.</p> <p>Conclusions</p> <p>Expression and synthesis of fls485 are found in surface lining epithelia of normal human intestinal mucosa and deriving epithelial cell lines. An interdependence of enterocyte differentiation along the crypt-villus axis and fls485 chaperone activity might be possible.</p
Regulation of mTORC1 Signaling by pH
BACKGROUND: Acidification of the cytoplasm and the extracellular environment is associated with many physiological and pathological conditions, such as intense exercise, hypoxia and tumourigenesis. Acidification affects important cellular functions including protein synthesis, growth, and proliferation. Many of these vital functions are controlled by mTORC1, a master regulator protein kinase that is activated by various growth-stimulating signals and inactivated by starvation conditions. Whether mTORC1 can also respond to changes in extracellular or cytoplasmic pH and play a role in limiting anabolic processes in acidic conditions is not known. METHODOLOGY/FINDINGS: We examined the effects of acidifying the extracellular medium from pH 7.4 to 6.4 on human breast carcinoma MCF-7 cells and immortalized mouse embryo fibroblasts. Decreasing the extracellular pH caused intracellular acidification and rapid, graded and reversible inhibition of mTORC1, assessed by measuring the phosphorylation of the mTORC1 substrate S6K. Fibroblasts deleted of the tuberous sclerosis complex TSC2 gene, a major negative regulator of mTORC1, were unable to inhibit mTORC1 in acidic extracellular conditions, showing that the TSC1-TSC2 complex is required for this response. Examination of the major upstream pathways converging on the TSC1-TSC2 complex showed that Akt signaling was unaffected by pH but that the Raf/MEK/ERK pathway was inhibited. Inhibition of MEK with drugs caused only modest mTORC1 inhibition, implying that other unidentified pathways also play major roles. CONCLUSIONS: This study reveals a novel role for the TSC1/TSC2 complex and mTORC1 in sensing variations in ambient pH. As a common feature of low tissue perfusion, low glucose availability and high energy expenditure, acidic pH may serve as a signal for mTORC1 to downregulate energy-consuming anabolic processes such as protein synthesis as an adaptive response to metabolically stressful conditions
Differential impact of chronic stress along the hippocampal dorsal–ventral axis
First published online 06 February 2014Stress impacts differently in distinct brain regions. However, so far few studies have focused on the differential responses triggered by stressful stimuli on the intrinsic functional heterogeneity of the hippocampal axis. In this study, we assessed the functional and structural alterations caused by exposure to a chronic unpredictable stress (CUS) paradigm on the dorsal-ventral axis of the hippocampus. The morphological analysis demonstrated that CUS had opposite outcomes in the structure of the dorsal (DH) and ventral hippocampus (VH): whereas in the DH, stress triggered a volumetric reduction as a result of atrophy of CA3 and CA1 apical dendrites, in the VH there was an increase in hippocampal volume concurrent with the increase of CA3 apical dendrites. In parallel, electrophysiological data revealed that stress led to a decrease in VH LTD. In summary, the present work showed that stress impacts differently on the structure and function of the DH and VH which contributes to better understand the overall spectrum of the central effects of stress.Pinto V and Mota C were supported by Fundacao para a Ciencia e Tecnologia (FCT) grants (SFRH/BPD/69132/2010; SFRH/BD/81881/2011, respectively). This work was supported by an FCT grant (PTDC/SAU-NSC/120590/2010). The authors declare no competing financial interests
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