Oxidative stress during rehabilitation from protein malnutrition associated with aerobic exercise in rats

This study was designed to evaluate biomarkers of oxidative stress in rats with or without aerobic exercise during recovery from protein malnutrition. From the 30(th) to the 90(th) day of life, male Wistar rats were fed a low protein diet (LP + 6%) followed by a normal protein diet (NP = 17%) until the 120(th) day and separated in two groups: sedentary (S) and exercise trained (E = swimming 1h/day, 5 days/Week, with from the 90(th) to the 120(th) day). Rats fed a normal protein diet were used as controls. Results showed that physical exercise had beneficial effects on body weight gain during nutrition rehabilitation. Erythrocytes catalase and glutathione reductase (biomarkers of the antioxidant system) were significantly reduced in all groups in comparison to the sedentary control group. The plasma concentration of TBARs (biomarkers of the oxidative damage) was also lower in the recovered rats, suggesting that the improvement in body growth after nutritional rehabilitation with physical exercise could be related to a decrease in the oxidative stress level.501455

The Toll-Like Receptor Signaling Molecule Myd88 Contributes to Pancreatic Beta-Cell Homeostasis in Response to Injury

Commensal flora and pathogenic microbes influence the incidence of diabetes in animal models yet little is known about the mechanistic basis of these interactions. We hypothesized that Myd88, an adaptor molecule in the Toll-like-receptor (TLR) pathway, regulates pancreatic β-cell function and homeostasis. We first examined β-cells histologically and found that Myd88−/− mice have smaller islets in comparison to C57Bl/6 controls. Myd88−/− mice were nonetheless normoglycemic both at rest and after an intra-peritoneal glucose tolerance test (IPGTT). In contrast, after low-dose streptozotocin (STZ) challenge, Myd88−/−mice had an abnormal IPGTT relative to WT controls. Furthermore, Myd88−/− mice suffer enhanced β-cell apoptosis and have enhanced hepatic damage with delayed recovery upon low-dose STZ treatment. Finally, we treated WT mice with broad-spectrum oral antibiotics to deplete their commensal flora. In WT mice, low dose oral lipopolysaccharide, but not lipotichoic acid or antibiotics alone, strongly promoted enhanced glycemic control. These data suggest that Myd88 signaling and certain TLR ligands mediate a homeostatic effect on β-cells primarily in the setting of injury

South American Plasmodium falciparum after the Malaria Eradication Era: Clonal Population Expansion and Survival of the Fittest Hybrids

Malaria has reemerged in many regions where once it was nearly eliminated. Yet the source of these parasites, the process of repopulation, their population structure, and dynamics are ill defined. Peru was one of malaria eradication's successes, where Plasmodium falciparum was nearly eliminated for two decades. It reemerged in the 1990s. In the new era of malaria elimination, Peruvian P. falciparum is a model of malaria reinvasion. We investigated its population structure and drug resistance profiles. We hypothesized that only populations adapted to local ecological niches could expand and repopulate and originated as vestigial populations or recent introductions. We investigated the genetic structure (using microsatellites) and drug resistant genotypes of 220 parasites collected from patients immediately after peak epidemic expansion (1999–2000) from seven sites across the country. The majority of parasites could be grouped into five clonal lineages by networks and AMOVA. The distribution of clonal lineages and their drug sensitivity profiles suggested geographic structure. In 2001, artesunate combination therapy was introduced in Peru. We tested 62 parasites collected in 2006–2007 for changes in genetic structure. Clonal lineages had recombined under selection for the fittest parasites. Our findings illustrate that local adaptations in the post-eradication era have contributed to clonal lineage expansion. Within the shifting confluence of drug policy and malaria incidence, populations continue to evolve through genetic outcrossing influenced by antimalarial selection pressure. Understanding the population substructure of P. falciparum has implications for vaccine, drug, and epidemiologic studies, including monitoring malaria during and after the elimination phase

Reference intervals for saliva analytes collected by a standardized method in a physically active population

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Objectives: Our aims were to test a liquid-based saliva collection system for total antioxidant status (TAS), uric acid (UA), total protein concentration (TP) and salivary alpha-amylase (SAA) activity; to determine if these analytes in serum and saliva are correlated in a physically active population and to establish reference intervals for these parameters. Design and methods: Participants in this study were 115 physically active males (18-20 years old). Saliva samples were collected using the Saliva Collection System (Greiner Bio-One (R)) immediately before obtaining blood. Biochemical analyses were conducted using an Autolab Boehringer analyzer. Results: We found a correlation between UA and TP concentrations in serum and saliva samples. The reference intervals for TP and SAA activity in the morning were lower than in the afternoon (p<0.0001). The reference intervals for UA and TAS did not vary with the time of collection. Conclusion: The establishment of reference intervals for these saliva constituents increases their diagnostic utility and allows for detection of physiological or pathological states. (c) 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.4417-1814401444Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Extecamp [927.7/0100]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Extecamp [927.7/0100