104 research outputs found
Exercise and postprandial lipemia: effects on vascular health in inactive adults
Background: There is evidence to suggest that postprandial lipemia are is linked to the impairment of endothelial
function, which is characterized by an imbalance between the actions of vasodilators and vasoconstrictors. The aim
of this study was to determine the effects of a 12-week high-intensity training (HIT) and moderate continuous
training (MCT) protocol on postprandial lipemia, vascular function and arterial stiffness in inactive adults after
high-fat meal (HFM) ingestion.
Methods: A randomized clinical trial was conducted in 20 healthy, inactive adults (31.6 ± 7.1 years). Participants followed
the two exercise protocols for 12 weeks. To induce a state of postprandial lipemia (PPL), all subjects received a HFM.
Endothelial function was measured using flow-mediated vasodilation (FMD), normalized brachial artery FMD (nFMD),
aortic pulse wave velocity (PWV) and augmentation index (AIx). Plasma total cholesterol, high-density lipoprotein
cholesterol (HDL-c), triglycerides and glucose were also measured.
Results: The effects of a HFM were evaluated in a fasted state and 60, 120, 180, and 240 min postprandially. A significant
decrease in serum glucose between 0 min (fasted state) and 120 min postprandially was found in the HIT group (P= 0.
035). Likewise, FMD (%) was significantly different between the fasted state and 60 min after a HFM in the HIT group
(P = 0.042). The total cholesterol response expressed as area under curve (AUC)(0â240) was lower following HIT than
following MCT, but no significant differences were observed (8%, P > 0.05). Similarly, triglycerides AUC(0â240) was also
lower after HIT compared with MCT, which trended towards significance (24%, P= 0.076). The AUC(0â240) for the glucose
response was significantly lower following HIT than MCT (10%, P = 0.008). FMD and nFMD AUC(0â240) were significantly
higher following HIT than following MCT (46.9%, P = 0.021 and 67.3%, P = 0.009, respectively). PWV AUC(0â240) did not
differ following between the two exercise groups (2.3%, P > 0.05).
Conclusions: Supervised exercise training mitigates endothelial dysfunction and glucose response induced by PPL.
Exercise intensity plays an important role in these protective effects, and medium-term HIT may be more effective than
MCT in reducing postprandial glucose levels and attenuating vascular impairment.This study as funded in part by the Center for Studies on Measurement of
Physical Activity, School of Medicine and Health Sciences, Universidad del
Rosario (Code N° FIUR DN-BG001). We declare that the results of the study
are presented clearly, honestly, and without fabrication, falsification, or appropriate
data manipulatio
The validation of pharmacogenetics for the identification of Fabry patients to be treated with migalastat
PURPOSE: Fabry disease is an X-linked lysosomal storage disorder caused by mutations in the α-galactosidase A gene. Migalastat, a pharmacological chaperone, binds to specific mutant forms of α-galactosidase A to restore lysosomal activity. METHODS: A pharmacogenetic assay was used to identify the α-galactosidase A mutant forms amenable to migalastat. Six hundred Fabry disease-causing mutations were expressed in HEK-293 (HEK) cells; increases in α-galactosidase A activity were measured by a good laboratory practice (GLP)-validated assay (GLP HEK/Migalastat Amenability Assay). The predictive value of the assay was assessed based on pharmacodynamic responses to migalastat in phase II and III clinical studies. RESULTS: Comparison of the GLP HEK assay results in in vivo white blood cell α-galactosidase A responses to migalastat in male patients showed high sensitivity, specificity, and positive and negative predictive values (â„0.875). GLP HEK assay results were also predictive of decreases in kidney globotriaosylceramide in males and plasma globotriaosylsphingosine in males and females. The clinical study subset of amenable mutations (n = 51) was representative of all 268 amenable mutations identified by the GLP HEK assay. CONCLUSION: The GLP HEK assay is a clinically validated method of identifying male and female Fabry patients for treatment with migalastat
Does Landscape Fragmentation Influence Sex Ratio of Dioecious Plants? A Case Study of Pistacia chinensis in the Thousand-Island Lake Region of China
The Thousand-Island Lake region in Zhejiang Province, China is a highly fragmented landscape with a clear point-in-time of fragmentation as a result of flooding to form the reservoir. Islands in the artificial lake were surveyed to examine how population sex ratio of a dioecious plant specie Pistacia chinensis B. was affected by landscape fragmentation. A natural population on the mainland near the lake was also surveyed for comparison. Population size, sex ratio and diameter at breast height (DBH) of individuals were measured over 2 years. More than 1,500 individuals, distributed in 31 populations, were studied. Soil nitrogen in the different populations was measured to identify the relationship between sex ratio and micro-environmental conditions. In accordance with the results of many other reports on biased sex ratio in relation to environmental gradient, we found that poor soil nitrogen areas fostered male-biased populations. In addition, the degree of sex ratio bias increased with decreasing population size and population connectivity. The biased sex ratios were only found in younger individuals (less than 50 years old) in small populations, while a stable 1â¶1 sex ratio was found in the large population on the mainland. We concluded that the effects of landscape fragmentation on the dioecious population sex ratio were mainly achieved in relation to changing soil nitrogen conditions in patches and pollen limitation within and among populations. Large populations could maintain a more suitable environment in terms of nutrient conditions and pollen flow, subsequently maintaining a stable sex ratio in dioecious plant populations. Both micro-environmental factors and spatial structure should be considered in fragmented landscape for the conservation of dioecious plant species
Residency patterns and migration dynamics of adult bull sharks (Carcharhinus leucas) on the east coast of southern Africa:
Bull sharks (Carcharhinus leucas) are globally distributed top predators that play an important ecological role within coastal marine communities. However, little is known about the spatial and temporal scales of their habitat use and associated ecological role. In this study, we employed passive acoustic telemetry to investigate the residency patterns and migration dynamics of 18 adult bull sharks (195â283 cm total length) tagged in southern Mozambique for a period of between 10 and 22 months. The majority of sharks (nâ=â16) exhibited temporally and spatially variable residency patterns interspersed with migration events. Ten individuals undertook coastal migrations that ranged between 433 and 709 km (mean â=â533 km) with eight of these sharks returning to the study site
Ecological Niche Dimensionality and the Evolutionary Diversification of Stick Insects
The degree of phenotypic divergence and reproductive isolation between taxon pairs can vary quantitatively, and often increases as evolutionary divergence proceeds through various stages, from polymorphism to population differentiation, ecotype and race formation, speciation, and post-speciational divergence. Although divergent natural selection promotes divergence, it does not always result in strong differentiation. For example, divergent selection can fail to complete speciation, and distinct species pairs sometimes collapse (âspeciation in reverseâ). Widely-discussed explanations for this variability concern genetic architecture, and the geographic arrangement of populations. A less-explored possibility is that the degree of phenotypic and reproductive divergence between taxon pairs is positively related to the number of ecological niche dimensions (i.e., traits) subject to divergent selection. Some data supporting this idea stem from laboratory experimental evolution studies using Drosophila, but tests from nature are lacking. Here we report results from manipulative field experiments in natural populations of herbivorous Timema stick insects that are consistent with this âniche dimensionalityâ hypothesis. In such insects, divergent selection between host plants might occur for cryptic colouration (camouflage to evade visual predation), physiology (to detoxify plant chemicals), or both of these niche dimensions. We show that divergent selection on the single niche dimension of cryptic colouration can result in ecotype formation and intermediate levels of phenotypic and reproductive divergence between populations feeding on different hosts. However, greater divergence between a species pair involved divergent selection on both niche dimensions. Although further replication of the trends reported here is required, the results suggest that dimensionality of selection may complement genetic and geographic explanations for the degree of diversification in nature
Dissecting the determinants of depressive disorders outcome: an in depth analysis of two clinical cases
Clinicians face everyday the complexity of depression. Available pharmacotherapies and psychotherapies improve patients suffering in a large part of subjects, however up to half of patients do not respond to treatment. Clinicians may forecast to a good extent if a given patient will respond or not, based on a number of data and sensations that emerge from face to face assessment. Conversely, clinical predictors of non response emerging from literature are largely unsatisfactory. Here we try to fill this gap, suggesting a comprehensive assessment of patients that may overcome the limitation of standardized assessments and detecting the factors that plausibly contribute to so marked differences in depressive disorders outcome. For this aim we present and discuss two clinical cases. Mr. A was an industrial manager who came to psychiatric evaluation with a severe depressive episode. His employment was demanding and the depressive episode undermined his capacity to manage it. Based on standardized assessment, Mr. A condition appeared severe and potentially dramatic. Mrs. B was a housewife who came to psychiatric evaluation with a moderate depressive episode. Literature predictors would suggest Mrs. B state as associated with a more favourable outcome. However the clinician impression was not converging with the standardized assessment and in fact the outcome will reverse the prediction based on the initial formal standard evaluation. Although the present report is based on two clinical cases and no generalizability is possible, a more detailed analysis of personality, temperament, defense mechanisms, self esteem, intelligence and social adjustment may allow to formalize the clinical impressions used by clinicians for biologic and pharmacologic studies
Opportunistic visitors: long-term behavioural response of bull sharks to food provisioning in Fiji
Shark-based tourism that uses bait to reliably attract certain species to specific sites so that divers can view them is a growing industry globally, but remains a controversial issue. We evaluate multi-year (2004–2011) underwater visual (n = 48 individuals) and acoustic tracking data (n = 82 transmitters; array of up to 16 receivers) of bull sharks Carcharhinus leucas from a long-term shark feeding site at the Shark Reef Marine Reserve and reefs along the Beqa Channel on the southern coast of Viti Levu, Fiji. Individual C. leucas showed varying degrees of site fidelity. Determined from acoustic tagging, the majority of C. leucas had site fidelity indexes >0.5 for the marine reserve (including the feeding site) and neighbouring reefs. However, during the time of the day (09:00–12:00) when feeding takes place, sharks mainly had site fidelity indexes <0.5 for the feeding site, regardless of feeding or non-feeding days. Site fidelity indexes determined by direct diver observation of sharks at the feeding site were lower compared to such values determined by acoustic tagging. The overall pattern for C. leucas is that, if present in the area, they are attracted to the feeding site regardless of whether feeding or non-feeding days, but they remain for longer periods of time (consecutive hours) on feeding days. The overall diel patterns in movement are for C. leucas to use the area around the feeding site in the morning before spreading out over Shark Reef throughout the day and dispersing over the entire array at night. Both focal observation and acoustic monitoring show that C. leucas intermittently leave the area for a few consecutive days throughout the year, and for longer time periods (weeks to months) at the end of the calendar year before returning to the feeding site
Postprandial lipemic and inflammatory responses to high-fat meals: a review of the roles of acute and chronic exercise
SK3 Channel Overexpression in Mice Causes Hippocampal Shrinkage Associated with Cognitive Impairments
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