45 research outputs found

    Thermal Variability Increases the Impact of Autumnal Warming and Drives Metabolic Depression in an Overwintering Butterfly

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    Increases in thermal variability elevate metabolic rate due to Jensen's inequality, and increased metabolic rate decreases the fitness of dormant ectotherms by increasing consumption of stored energy reserves. Theory predicts that ectotherms should respond to increased thermal variability by lowering the thermal sensitivity of metabolism, which will reduce the impact of the warm portion of thermal variability. We examined the thermal sensitivity of metabolic rate of overwintering Erynnis propertius (Lepidoptera: Hesperiidae) larvae from a stable or variable environment reared in the laboratory in a reciprocal common garden design, and used these data to model energy use during the winters of 1973–2010 using meteorological data to predict the energetic outcomes of metabolic compensation and phenological shifts. Larvae that experienced variable temperatures had decreased thermal sensitivity of metabolic rate, and were larger than those reared at stable temperatures, which could partially compensate for the increased energetic demands. Even with depressed thermal sensitivity, the variable environment was more energy-demanding than the stable, with the majority of this demand occurring in autumn. Autumn phenology changes thus had disproportionate influence on energy consumption in variable environments, and variable-reared larvae were most susceptible to overwinter energy drain. Therefore the energetic impacts of the timing of entry into winter dormancy will strongly influence ectotherm fitness in northern temperate environments. We conclude that thermal variability drives the expression of metabolic suppression in this species; that phenological shifts will have a greater impact on ectotherms in variable thermal environments; and that E. propertius will be more sensitive to shifts in phenology in autumn than in spring. This suggests that increases in overwinter thermal variability and/or extended, warm autumns, will negatively impact all non-feeding dormant ectotherms which lack the ability to suppress their overwinter metabolic thermal sensitivity

    Dietary Re-education, Exercise Program, Performance and Body Indexes Associated with Risk Factors in Overweight/Obese Women

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    This study observed the effect of a dietary re-education plus regular physical activity on body composition, risk factors and physical test performance of sedentary overweight/obese women and to correlate these variables one with each other. Fifty women (36 ± 10 yrs; 31 ± 6 body mass index (BMI, kg/m2)) volunteered for the study. Body compositions were obtained by anthropometry and bioimpedance and some body indexes were established. One-repetition maximum (1-RM) and treadmill VO2max tests were carried out and blood samples were obtained for lipid, glucose and uric acid analyses before (T1) and after two months of intervention (T2). Diet was established by indirect calorimetry. Body fat, glucose, uric acid, total cholesterol, HDL-cholesterol and systolic blood pressure were significantly reduced. The 1-RM and VO2max tests were significantly increased. Neck circumference (NC) was correlated with body composition, back muscle 1-MR, HDL and LDL cholesterol, total cholesterol/HDL ratio, uric acid, and resting energy expenditure. BMI was found to be significantly correlated with waist/hip ratio, circumference sum, and body fat percentage by anthropometry and bioimpedance. Body fat percentage determined by bioimpedance and anthropometry was significantly correlated with arm fat area and arm fat area corrected respectively, and both with BMI at T1 and T2. This study suggests that a dietary reeducation plus physical activity around 200 min/week improved body composition and the health of these women. Many anthropometry measurements have correspondence to risk factors and NC could be a simple approach to reflect these results, without other more complex techniques

    A survey of the clinicopathological and molecular characteristics of patients with suspected Lynch syndrome in Latin America

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    Background: Genetic counselling and testing for Lynch syndrome (LS) have recently been introduced in several Latin America countries. We aimed to characterize the clinical, molecular and mismatch repair (MMR) variants spectrum of patients with suspected LS in Latin America. Methods: Eleven LS hereditary cancer registries and 34 published LS databases were used to identify unrelated families that fulfilled the Amsterdam II (AMSII) criteria and/or the Bethesda guidelines or suggestive of a dominant colorectal (CRC) inheritance syndrome. Results: We performed a thorough investigation of 15 countries and identified 6 countries where germline genetic testing for LS is available and 3 countries where tumor testing is used in the LS diagnosis. The spectrum of pathogenic MMR variants included MLH1 up to 54%, MSH2 up to 43%, MSH6 up to 10%, PMS2 up to 3% and EPCAM up to 0.8%. The Latin America MMR spectrum is broad with a total of 220 different variants which 80% were private and 20% were recurrent. Frequent regions included exons 11 of MLH1 (15%), exon 3 and 7 of MSH2 (17 and 15%, respectively), exon 4 of MSH6 (65%), exons 11 and 13 of PMS2 (31% and 23%, respectively). Sixteen international founder variants in MLH1, MSH2 and MSH6 were identified and 41 (19%) variants have not previously been reported, thus representing novel genetic variants in the MMR genes. The AMSII criteria was the most used clinical criteria to identify pathogenic MMR carriers although microsatellite instability, immunohistochemistry and family history are still the primary methods in several countries where no genetic testing for LS is available yet. Conclusion: The Latin America LS pathogenic MMR variants spectrum included new variants, frequently altered genetic regions and potential founder effects, emphasizing the relevance implementing Lynch syndrome genetic testing and counseling in all of Latin America countries.Radium Hospital Foundation (Oslo, Norway) in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript, Helse Sør-Øst (Norway) in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript, the French Association Recherche contre le Cancer (ARC) in the analysis, and interpretation of data, the Groupement des Entreprises Françaises dans la Lutte contre le Cancer (Gefluc) in the analysis, and interpretation of data, the Association Nationale de la Recherche et de la Technologie (ANRT, CIFRE PhD fellowship to H.T.) in the analysis, and interpretation of data and by the OpenHealth Institute in the analysis, and interpretation of data. Barretos Cancer Hospital received financial support by FINEP-CT-INFRA (02/2010)info:eu-repo/semantics/publishedVersio

    Proteins of Leishmania (Viannia) shawi confer protection associated with Th1 immune response and memory generation

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    <p>Abstract</p> <p>Background</p> <p><it>Leishmania (Viannia) shawi </it>parasite was first characterized in 1989. Recently the protective effects of soluble leishmanial antigen (SLA) from <it>L. (V.) shawi </it>promastigotes were demonstrated using BALB/c mice, the susceptibility model for this parasite. In order to identify protective fractions, SLA was fractionated by reverse phase HPLC and five antigenic fractions were obtained.</p> <p>Methods</p> <p>F1 fraction was purified from L. (V.) shawi parasite extract by reverse phase HPLC. BALB/c mice were immunized once a week for two consecutive weeks by subcutaneous routes in the rump, using 25 μg of F1. After 1 and 16 weeks of last immunization, groups were challenged in the footpad with L. (V.) shawi promastigotes. After 2 months, those same mice were sacrificed and parasite burden, cellular and humoral immune responses were evaluated.</p> <p>Results</p> <p>The F1 fraction induced a high degree of protection associated with an increase in IFN-γ, a decrease in IL-4, increased cell proliferation and activation of CD8<sup>+</sup>T lymphocytes. Long-term protection was acquired in F1-immunized mice, associated with increased CD4<sup>+ </sup>central memory T lymphocytes and activation of both CD4<sup>+ </sup>and CD8<sup>+ </sup>T cells. In addition, F1-immunized groups showed an increase in IgG2a levels.</p> <p>Conclusions</p> <p>The inductor capability of antigens to generate memory lymphocytes that can proliferate and secrete beneficial cytokines upon infection could be an important factor in the development of vaccine candidates against American Tegumentary Leishmaniasis.</p
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