278 research outputs found

    Effects of beta-alanine supplementation on brain homocarnosine/carnosine signal and cognitive function: an exploratory study

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    Objectives: Two independent studies were conducted to examine the effects of 28 d of beta-alanine supplementation at 6.4 g d-1 on brain homocarnosine/carnosine signal in omnivores and vegetarians (Study 1) and on cognitive function before and after exercise in trained cyclists (Study 2). Methods: In Study 1, seven healthy vegetarians (3 women and 4 men) and seven age- and sex-matched omnivores undertook a brain 1H-MRS exam at baseline and after beta-alanine supplementation. In study 2, nineteen trained male cyclists completed four 20-Km cycling time trials (two pre supplementation and two post supplementation), with a battery of cognitive function tests (Stroop test, Sternberg paradigm, Rapid Visual Information Processing task) being performed before and after exercise on each occasion. Results: In Study 1, there were no within-group effects of beta-alanine supplementation on brain homocarnosine/carnosine signal in either vegetarians (p = 0.99) or omnivores (p = 0.27); nor was there any effect when data from both groups were pooled (p = 0.19). Similarly, there was no group by time interaction for brain homocarnosine/carnosine signal (p = 0.27). In study 2, exercise improved cognitive function across all tests (P0.05) of beta-alanine supplementation on response times or accuracy for the Stroop test, Sternberg paradigm or RVIP task at rest or after exercise. Conclusion: 28 d of beta-alanine supplementation at 6.4g d-1 appeared not to influence brain homocarnosine/ carnosine signal in either omnivores or vegetarians; nor did it influence cognitive function before or after exercise in trained cyclists

    The Echinococcus canadensis (G7) genome: A key knowledge of parasitic platyhelminth human diseases

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    Background: The parasite Echinococcus canadensis (G7) (phylum Platyhelminthes, class Cestoda) is one of the causative agents of echinococcosis. Echinococcosis is a worldwide chronic zoonosis affecting humans as well as domestic and wild mammals, which has been reported as a prioritized neglected disease by the World Health Organisation. No genomic data, comparative genomic analyses or efficient therapeutic and diagnostic tools are available for this severe disease. The information presented in this study will help to understand the peculiar biological characters and to design species-specific control tools. Results: We sequenced, assembled and annotated the 115-Mb genome of E. canadensis (G7). Comparative genomic analyses using whole genome data of three Echinococcus species not only confirmed the status of E. canadensis (G7) as a separate species but also demonstrated a high nucleotide sequences divergence in relation to E. granulosus (G1). The E. canadensis (G7) genome contains 11,449 genes with a core set of 881 orthologs shared among five cestode species. Comparative genomics revealed that there are more single nucleotide polymorphisms (SNPs) between E. canadensis (G7) and E. granulosus (G1) than between E. canadensis (G7) and E. multilocularis. This result was unexpected since E. canadensis (G7) and E. granulosus (G1) were considered to belong to the species complex E. granulosus sensu lato. We described SNPs in known drug targets and metabolism genes in the E. canadensis (G7) genome. Regarding gene regulation, we analysed three particular features: CpG island distribution along the three Echinococcus genomes, DNA methylation system and small RNA pathway. The results suggest the occurrence of yet unknown gene regulation mechanisms in Echinococcus. Conclusions: This is the first work that addresses Echinococcus comparative genomics. The resources presented here will promote the study of mechanisms of parasite development as well as new tools for drug discovery. The availability of a high-quality genome assembly is critical for fully exploring the biology of a pathogenic organism. The E. canadensis (G7) genome presented in this study provides a unique opportunity to address the genetic diversity among the genus Echinococcus and its particular developmental features. At present, there is no unequivocal taxonomic classification of Echinococcus species; however, the genome-wide SNPs analysis performed here revealed the phylogenetic distance among these three Echinococcus species. Additional cestode genomes need to be sequenced to be able to resolve their phylogeny.Fil: Maldonado, Lucas Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Assis, Juliana. Fundación Oswaldo Cruz; BrasilFil: Gomes Araújo, Flávio M.. Fundación Oswaldo Cruz; BrasilFil: Salim, Anna C. M.. Fundación Oswaldo Cruz; BrasilFil: Macchiaroli, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Cucher, Marcela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Camicia, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Fox, Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Rosenzvit, Mara Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Oliveira, Guilherme. Instituto Tecnológico Vale; Brasil. Fundación Oswaldo Cruz; BrasilFil: Kamenetzky, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin

    Quantitative effects of tobacco smoking exposure on the maternal-fetal circulation

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    <p>Abstract</p> <p>Background</p> <p>Despite the existence of various published studies regarding the effects of tobacco smoking on pregnancy, and especially in regards to placental blood flow and vascular resistance, some points still require clarification. In addition, the amount of damage due to tobacco smoking exposure that occurs has not been quantified by objective means. In this study, we looked for a possible association between flow resistance indices of several arteries and the levels of urinary cotinine and the concentration of carbon monoxide in the exhaled air (COex) of both smoking and non-smoking pregnant women. We also looked for a relationship between those findings and fetal growth and birth weight.</p> <p>Methods</p> <p>In a prospective design, thirty pregnant smokers and thirty-four pregnant non-smokers were studied. The volunteers signed consent forms, completed a self-applied questionnaire and were subjected to Doppler velocimetry. Tobacco smoking exposure was quantified by subject provided information and confirmed by the measurement of urinary cotinine levels and by the concentration of carbon monoxide in the exhaled air (COex). The weight of newborns was evaluated immediately after birth.</p> <p>Results</p> <p>Comparing smoking to non-smoking pregnant women, a significant increase in the resistance index was observed in the uterine arteries (P = 0.001) and umbilical artery (P = 0.001), and a decrease in the middle cerebral artery (P = 0.450). These findings were associated with progressively higher concentrations of COex and urinary cotinine. A decrease in the birth weight was also detected (P < 0.001) in association with a progressive increase in the tobacco exposure of the pregnant woman.</p> <p>Conclusions</p> <p>In pregnant women who smoke, higher arterial resistance indices and lower birth weights were observed, and these findings were associated with increasing levels of tobacco smoking exposure. The values were significantly different when compared to those found in non-smoking pregnant women. This study contributes to the findings that smoking damage during pregnancy is dose-dependent, as demonstrated by the objective methods for measuring tobacco smoking exposure.</p

    Re-Emergence of Crimean-Congo Hemorrhagic Fever Virus in Central Africa

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    Crimean-Congo hemorrhagic fever virus (CCHFV) is transmitted to humans through tick-bite or contact with infected blood or tissues from livestock, the main vertebrate hosts in a peri-domestic natural cycle. With numerous outbreaks, a high case fatality rate (3%–30%) and a high risk for nosocomial transmission, CCHFV became a public health concern in Europe and Asia. However virus surveillance in Africa is difficult due to the limited sanitary facilities. Especially, CCHFV occurrence in Central Africa is very poorly described and seems highly in contrast with the temperate to dry environments to which the virus is usually associated with. We described a single human infection that occurred in Democratic Republic of the Congo after nearly 50 years of absence. The phylogenetic analysis suggests that CCHFV enzootic circulation in the area is still ongoing despite the absence of notification, and thus reinforces the need for the medical workers and authorities to be aware of the outbreak risk. The source of infection seemed associated with a forest environment while no link with the usual agro-pastoral risk factors could be identified. More accurate ecological data about CCHFV enzootic cycle are required to assess the risk of emergence in developing countries subjected to deforestation

    Turtle Carapace Anomalies: The Roles of Genetic Diversity and Environment

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    Background: Phenotypic anomalies are common in wild populations and multiple genetic, biotic and abiotic factors might contribute to their formation. Turtles are excellent models for the study of developmental instability because anomalies are easily detected in the form of malformations, additions, or reductions in the number of scutes or scales. Methodology/Principal Findings: In this study, we integrated field observations, manipulative experiments, and climatic and genetic approaches to investigate the origin of carapace scute anomalies across Iberian populations of the European pond turtle, Emys orbicularis. The proportion of anomalous individuals varied from 3 % to 69 % in local populations, with increasing frequency of anomalies in northern regions. We found no significant effect of climatic and soil moisture, or climatic temperature on the occurrence of anomalies. However, lower genetic diversity and inbreeding were good predictors of the prevalence of scute anomalies among populations. Both decreasing genetic diversity and increasing proportion of anomalous individuals in northern parts of the Iberian distribution may be linked to recolonization events from the Southern Pleistocene refugium. Conclusions/Significance: Overall, our results suggest that developmental instability in turtle carapace formation might be caused, at least in part, by genetic factors, although the influence of environmental factors affecting the developmental stability of turtle carapace cannot be ruled out. Further studies of the effects of environmental factors, pollutants an

    Disruption of TBP-2 ameliorates insulin sensitivity and secretion without affecting obesity

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    Type 2 diabetes mellitus (T2DM) is characterized by defects in both insulin sensitivity and glucose-stimulated insulin secretion (GSIS) and is often accompanied by obesity. In this study, we show that disruption of thioredoxin binding protein-2 (TBP-2, also called Txnip) in obese mice (ob/ob) dramatically improves hyperglycaemia and glucose intolerance, without affecting obesity or adipocytokine concentrations. TBP-2-deficient ob/ob mice exhibited enhanced insulin sensitivity with activated insulin receptor substrate-1/Akt signalling in skeletal muscle and GSIS in islets compared with ob/ob mice. The elevation of uncoupling protein-2 (UCP-2) expression in ob/ob islets was downregulated by TBP-2 deficiency. TBP-2 overexpression suppressed glucose-induced adenosine triphosphate production, Ca2+ influx and GSIS. In β-cells, TBP-2 enhanced the expression level and transcriptional activity of UCP-2 by recruitment of peroxisome proliferator-activated receptor-γ co-activator-1α to the UCP-2 promoter. Thus, TBP-2 is a key regulatory molecule of both insulin sensitivity and GSIS in diabetes, raising the possibility that inhibition of TBP-2 may be a novel therapeutic approach for T2DM

    Beta-alanine (Carnosyn™) supplementation in elderly subjects (60–80 years): effects on muscle carnosine content and physical capacity

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    The aim of this study was to investigate the effects of beta-alanine supplementation on exercise capacity and the muscle carnosine content in elderly subjects. Eighteen healthy elderly subjects (60–80 years, 10 female and 4 male) were randomly assigned to receive either beta-alanine (BA, n = 12) or placebo (PL, n = 6) for 12 weeks. The BA group received 3.2 g of beta-alanine per day (2 × 800 mg sustained-release Carnosyn™ tablets, given 2 times per day). The PL group received 2 × (2 × 800 mg) of a matched placebo. At baseline (PRE) and after 12 weeks (POST-12) of supplementation, assessments were made of the muscle carnosine content, anaerobic exercise capacity, muscle function, quality of life, physical activity and food intake. A significant increase in the muscle carnosine content of the gastrocnemius muscle was shown in the BA group (+85.4%) when compared with the PL group (+7.2%) (p = 0.004; ES: 1.21). The time-to-exhaustion in the constant-load submaximal test (i.e., TLIM) was significantly improved (p = 0.05; ES: 1.71) in the BA group (+36.5%) versus the PL group (+8.6%). Similarly, time-to-exhaustion in the incremental test was also significantly increased (p = 0.04; ES 1.03) following beta-alanine supplementation (+12.2%) when compared with placebo (+0.1%). Significant positive correlations were also shown between the relative change in the muscle carnosine content and the relative change in the time-to-exhaustion in the TLIM test (r = 0.62; p = 0.01) and in the incremental test (r = 0.48; p = 0.02). In summary, the current data indicate for the first time, that beta-alanine supplementation is effective in increasing the muscle carnosine content in healthy elderly subjects, with subsequent improvement in their exercise capacity
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