Rosiglitazone reverses tenofovir-induced nephrotoxicity

Tenofovir disoproxil fumarate (TDF) is a first-line drug used in patients with highly active retroviral disease; however, it can cause renal failure associated with many tubular anomalies that may be due to down regulation of a variety of ion transporters. Because rosiglitazone, a peroxisome proliferator-activated receptor-gamma agonist induces the expression of many of these same transporters, we tested if the nephrotoxicity can be ameliorated by its use. High doses of TDF caused severe renal failure in rats accompanied by a reduction in endothelial nitric-oxide synthase and intense renal vasoconstriction; all of which were significantly improved by rosiglitazone treatment. Low-dose TDF did not alter glomerular filtration rate but produced significant phosphaturia, proximal tubular acidosis, polyuria and a reduced urinary concentrating ability. These alterations were caused by specific downregulation of the sodium-phosphorus cotransporter, sodium/hydrogen exchanger 3 and aquaporin 2. A Fanconi`s-like syndrome was ruled out as there was no proteinuria or glycosuria. Rosiglitazone reversed TDF-induced tubular nephrotoxicity, normalized urinary biochemical parameters and membrane transporter protein expression. These studies suggest that rosiglitazone treatment might be useful in patients presenting with TFV-induced nephrotoxicity especially in those with hypophosphatemia or reduced glomerular filtration rate.FAPESP, Foundation for the Support of Research in the state of Sao PauloLIM, Laboratory for Medical ResearchFFM, School of Medicine FoundationCNPq, National Council for Scientific and Technological Developmen

NATURAL RADIOACTIVITY IN EXTREME SOUTH OF BAHIA, BRAZIL USING GAMMA-RAY SPECTROMETRY

ABSTRACT The concentrations activity of natural radionuclides in beach sand in extreme south of Bahia-Brazil was measured using gamma-ray spectrometry. The activity concentrations of 226 Ra, 232 Th and 40 K in beach sand ranged from 14.5 to 8,318.4, 20.5 to 18,450.0, 15.4 to 3,109.0 Bq/kg, with a mean value of 1,078.2, 2,429.6, and 417.0 Bq/kg respectively. The values of radiation hazard indexes in sands of Alcobaça, Caraíva and Cumuruxatiba are higher than the limits preconized by Beretka and Mathew. The use of these sands may be not safe in building constructions. The results show that the absorbed dose rates range from 20.4-15,116.6 nGy/h with mean value of 1762.7. The highest value of gamma dose rates among the studied beaches was found in Cumuruxatiba (15,116.6 nGy/h). The annual effective dose varied between 0.028 and 18.539 mSv/year, with a mean of 2.162 mSv/year. Values of Alcobaça, Trancoso, Caraíva and Cumuruxatiba are higher than the worldwide average for outdoor annual effective dose, 0.07 mSv/year

Resistance Exercise Training Improves Metabolic and Inflammatory Control in Adipose and Muscle Tissues in Mice Fed a High-Fat Diet

This study investigates whether ladder climbing (LC), as a model of resistance exercise, can reverse whole-body and skeletal muscle deleterious metabolic and inflammatory effects of high-fat (HF) diet-induced obesity in mice. To accomplish this, Swiss mice were fed for 17 weeks either standard chow (SC) or an HF diet and then randomly assigned to remain sedentary or to undergo 8 weeks of LC training with progressive increases in resistance weight. Prior to beginning the exercise intervention, HF-fed animals displayed a 47% increase in body weight (BW) and impaired ability to clear blood glucose during an insulin tolerance test (ITT) when compared to SC animals. However, 8 weeks of LC significantly reduced BW, adipocyte size, as well as glycemia under fasting and during the ITT in HF-fed rats. LC also increased the phosphorylation of AktSer473 and AMPKThr172 and reduced tumor necrosis factor-alpha (TNF-α) and interleukin 1 beta (IL1-β) contents in the quadriceps muscles of HF-fed mice. Additionally, LC reduced the gene expression of inflammatory markers and attenuated HF-diet-induced NADPH oxidase subunit gp91phox in skeletal muscles. LC training was effective in reducing adiposity and the content of inflammatory mediators in skeletal muscle and improved whole-body glycemic control in mice fed an HF diet

Doses de nitrogênio e fósforo para produção econômica de milho na Chapada do Apodi, RN

Este estudo foi realizado no município de Baraúna, RN, no ano agrícola de 2010, em um Cambissolo Háplico eutrófico e derivado de calcário objetivando definir a melhor combinação das doses de nitrogênio (N) e fósforo (P) associadas à máxima produção econômica de grãos de milho, assim como os níveis críticos de N na folha e de P no solo e na folha. Foram aplicados 17 tratamentos sendo 16 resultantes da combinação entre quatro doses de N (30, 60, 90 e 120 kg ha-1) e de quatro doses de P2O5 (30, 60, 90 e 120 kg ha-1) e um tratamento testemunha no qual não se aplicou nenhuma dose desses nutrientes. O delineamento experimental utilizado foi o de blocos ao acaso, com quatro repetições. A melhor combinação das doses de N e de P2O5 recomendadas para a produção de máxima eficiência econômica de grãos foi de 70 kg ha-1 de N combinado com 120 kg ha-1 de P2O5. Os níveis críticos de N na folha e de P no solo e na folha, associados à produção de máxima eficiência econômica de grãos de milho foram, respectivamente, de 32,93 g kg-1, de 7,97 mg dm-3 e de 3,11 g kg-1