Virulent Mycobacterium fortuitum restricts NO production by a gamma interferon-activated J774 cell line and phagosome-lysosome fusion

The virulence of different isolates of Mycobacterium has been associated with two morphologically distinguishable colonial variants: opaque (SmOp) and transparent (SmTr). In this report we used an in vitro assay to compare macrophage (Mphi) responses to SmOp and SmTr Mycobacterium fortuitum variants, taking advantage of the fact that these variants were derived from the same isolate. Cells preactivated or not with gamma interferon (IFN-gamma) were infected with SmOp or SmTr M. fortuitum. We showed that SmOp and SmTr induced different levels of nitric oxide (NO) production by IFN-gamma-stimulated Mphi. Indeed, the amount of IFN-gamma-induced NO production by J774 cells was 4.8 to 9.0 times higher by SmOp (23.1 to 37.7 micro M) compared to SmTr infection (3.9 to 4.8 micro M) (P = 0.0332), indicating that virulent SmTr bacilli restricted NO production. In addition, IFN-gamma-induced NO production by Mphi was higher when correlated with reduction of only avirulent SmOp bacillus viability. SNAP (S-nitroso-N-acetyl-DL-penicillamine)-induced NO production did not modify SmTr viability, indicating its resistance to nitrogen radicals. Electron microscopy studies were performed to evaluate the capacity of phagosomes to fuse with lysosomes labeled with bovine serum albumin-colloidal gold particles. By 24 h postinfection, 69% more phagosome-containing SmOp variant had fused with lysosomes compared to the SmTr-induced phagosomes. In conclusion, these data indicate that virulent SmTr bacilli may escape host defense by restricting IFN-gamma-induced NO production, resisting nitrogen toxic radicals, and limiting phagosome fusion with lysosomes.     

Influence of a preventive training program on lower limb kinematics and vertical jump height of male volleyball athletes

ObjectiveTo examine the influence of a preventative training program (PTP) on sagittal plane kinematics during different landing tasks and vertical jump height (VJH) in males.DesignSix weeks prospective exercise intervention.ParticipantsFifteen male volleyball athletes (13 ± 0.7 years, 1.70 ± 0.12 m, 60 ± 12 kg).InterventionsPTP consisting of plyometric, balance and core stability exercises three times per week for six weeks. Bilateral vertical jumps with double leg (DL) and single leg (SL) landings were performed to measure the effects of training.Main outcome measurementsKinematics of the knee and hip before and after training and VJH attained during both tasks after training. The hypothesis was that the PTP would produce improvements in VJH, but would not generate great changes in biomechanical behavior.ResultsThe only change identified for the SL was the longest duration of landing, which represents the time spent from initial ground contact to maximum knee flexion, after training, while increased angular displacement of the knee was observed during DL. The training did not significantly alter the VJH in either the SL (difference: 2.7 cm) or the DL conditions (difference: 3.5 cm).ConclusionsDespite the PTP’s effectiveness in inducing some changes in kinematics, the changes were specific for each task, which highlights the importance of the specificity and individuality in selecting prevention injury exercises. Despite the absence of significant increases in the VJH, the absolute differences after training showed increases corroborating with the findings of statistically powerful studies that compared the results with control groups. The results suggest that short-term PTPs in low risk young male volleyball athletes may enhance performance and induce changes in some kinematic parameters.     

Myocardial reperfusion: leukocyte accumulation in the ischemic and remote non-ischemic regions

Neutrophil accumulation in the first hour of myocardial reperfusion was assessed in dog hearts submitted to ischemia with and without necrosis. In anesthetized dogs, the left anterior descending coronary artery was occluded for 20 min (group IS-20 n = 7) and for 90 min (group IS-90 n = 6). Immediately after reperfusion, 99m Tc-Ceretec (Exametazime-Amersham) labeled neutrophils were injected into a central vein and 60 min later the dogs were killed. The left ventricle was isolated, weighed, and sliced. Six sections, 3 from normal and 3 from reperfused regions, were divided into endocardial and epicardial layers. Myocardial and blood radiometry were used to evaluate the neutrophil accumulation during reperfusion. The differences between leukocyte accumulation in both groups were assessed comparing the ischemic/normal relations in the endocardial and epicardial layers. A second comparison considered myocardium/blood relations to allow the evaluation of differences between remote normal myocardial areas of the two experimental groups. In dogs submitted to 20 min of ischemia, leukocytes accumulated significantly more (P < 0.01) in the reperfused myocardium as compared with the non-ischemic region. The increase occurred both in the endocardial (1.49+/-0.20) and epicardial (1.48+/-0.29) regions. After 90 min ischemia, leukocyte accumulation was more intense and predominant in endocardium where there was a 4-fold (3.97+/-1.28) increase over the non-ischemic region, while in the epicardium this relation was only 2.5-fold (2.56+/-0.98). In the remote non-ischemic myocardium, leukocyte accumulation was greater in dogs submitted to 90 min of ischemia compared to the 20 min group (P < 0.01), without distinction between endocardial and epicardial layers. This accumulation in territories of non-culprit coronary arteries may be related to the blood flow abnormalities and matrix structure changes that occur in these regions during the development of an acute myocardial infarction and its natural repair.     

Prolonged consumption of flaxseed flour increases the 17β-estradiol hormone without causing adverse effects on the histomorphology of Wistar rats’ penis

Consumption of foods rich in phytoestrogens such as flaxseed has increased due to its chemoprotective effects, especially those related to the cardiovascular system. The flaxseed has components that can interfere with development of male reproductive system. This study aims to investigate the possible effects of prolonged consumption of flaxseed flour on hormonal and histomorphologic penis parameters of adult Wistar rats. Rat dams were divided into two groups during lactation period: the control group that was fed with diet based on casein and the flaxseed group that was fed with diet based on casein containing 25% of flaxseed . At weaning, 10 male offspring from each group continued to receive the experimental diets until 250 days old. Rats fed with diet containing flaxseed showed increased concentrations of 17β-estradiol (p = 0.01) but no changes in testosterone concentrations. With regard to histomorphometric analysis of the penis, supplemented rats had lower values for the total area of the corpus spongiosum (p = 0.01). All other analyzed parameters wer e similar as the control. Results showed that the use of flaxseed flour did not cause adverse effects on the penis morphology but increases the 17β-estradiol hormone, when consumed in integral form for a prolonged period.     

Effect of Lutzomyia longipalpis salivary gland extracts on leukocyte migration induced by Leishmania major

The mechanism by which the salivary gland lysate (SGL) of Lutzomyia longipalpis enables Leishmania infection remains under investigation. One possibility is that saliva promotes cellular recruitment leading to development of skin lesions. In this study, we investigated leukocyte recruitment induced by L. major, L. major + SGL, or SGL alone into the peritoneal cavity of BALB/c mice. The administration of L. major with or without SGL induced neutrophil migration six hours after infection. Interestingly, after seven days, the BALB/c mice still had eosinophils and mononuclear cells in their peritoneal cavities. Flow cytometric analysis showed an increase in the CD4(+) CD45RB(low) T cell subset (effector or memory cells) compared with the CD4(+) CD45RB(high) subset (naive cells). Moreover, the co-injection of L. major with SGL enhanced production of interleukin-10. These results suggest that SGL can facilitate Leishmania infection by modulating leukocyte recruitment and Th2 cytokine production at the inflammatory focus.     

Histological and Genotoxic Biomarkers in <Emphasis Type="Italic">Prochilodus lacustris</Emphasis> (Pisces,Prochilodontidae) for Environmental Assessment in a Protected Area in the Northeast of Brazil

The quality of aquatic environments all around the world is being altered by different human activities that represent direct threat to the ecological system and the aquatic biota. This study aimed to evaluate the occurrence of histological and genotoxic alterations in Prochilodus lacustris as indicators of anthropic impacts in a lacustrine environment in northeast Brazil. The histological alterations were evaluated using the histological alteration index, and the genotoxic alterations were detected using the micronuclei test, at three sampling stations (S1, S2 and S3). The gills presented lesions with three stages of severity, with mild lesions more frequent in the specimens collected at station S1. Mild hepatic tissue lesions were the most frequent type in both areas. Micronucleus analysis showed that station S3 was the most affected. The biological responses observed indicated that the fish are under influence of environmental changes. It is important to highlight that the organisms collected at station S3 had a more compromised health status.     

Musculoskeletal disorders in nursing workers: evidences associated to work conditions

This paper presents a review of national scientific articles that researched about musculoskeletal disorders in nursing workers. It was analyzed the articles published in MEDLINE, LILACS, BDENF-BIREME data basis, during the period of 1996 to 2005. The following selection criteria were adopted: musculoskeletal outcomes, nursing workers' population and publications in national journals indexed in the BIREME system. Fifteen articles met all the selection criteria. In most of them, the inappropriate work conditions were identified as risk factors for the development of musculoskeletal disorders. In these articles, the authors debate the necessity, not only, of a more in-depth research method about musculoskeletal disorders related to the nursing job, but also, the necessity to rethink the work organization.