Effects of induced diabetes and the administration of aminoguanidine in the biomechanical retention of implants: a study in rats.

BACKGROUND AND OBJECTIVE: The present study aimed to assess the effects of induced diabetes and the administration of aminoguanidine in the biomechanical retention of implants in rats. MATERIAL AND METHODS: Thirty-six rats were randomly divided into six groups: group 1, healthy rats (no aminoguanidine); group 2 and group 3, healthy rats receiving 10 and 20 mg/kg of aminoguanidine daily, respectively; group 4, diabetic rats (no aminoguanidine); and group 5 and group 6, diabetic rats receiving 10 and 20 mg/kg of aminoguanidine daily, respectively. In each rat an implant was inserted in the femur. After 28 d of healing, the rats were killed. The implants were removed by applying a counter-torque, and the maximum force required for the rupture of the bone-implant interface was recorded using an analog torque meter. The data were evaluated using analysis of variance and the Student's t-test. RESULTS: In the healthy groups, no statistically significant difference could be observed in the average counter-torque values for implant removal, whereas in the diabetic groups, a daily dose of 20 mg/kg of aminoguanidine raised the counter-torque values to the values found in healthy rats. CONCLUSION: The administration of 20 mg/kg of aminoguanidine daily in diabetic rats raised the biomechanical retention of the implants to the level observed in the healthy rat group.

Worker evaluation of a macroergonomic intervention in a Brazilian footwear company.

This article presents a macroergonomic intervention in a Brazilian footwear company and its evaluation by the workers. Using participatory ergonomics, the traditional Taylor/Ford production system was transformed into a socio-technical one and tested by 100 volunteers working during 3.5 years in a pilot production line. Multiskilling and teamwork were the major changes promoted to enlarge and enrich work and make it more flexible. The workers' evaluation pre- and post-intervention showed an increase in overall satisfaction with the work and more commitment to the results and company targets. STATEMENT OF RELEVANCE: This study showed that problems and solutions can be identified through participatory ergonomics, that it is easier to involve workers than the managerial staff, and that a macroergonomic intervention, mainly focusing on work organization, led to positive personnel, health and production outcomes, despite management's resistance to changes.

Correlating denitrifying catabolic genes with N2O and N2 emissions from swine slurry composting.

This work evaluated N dynamics that occurs over time within swine slurry composting piles. Real-time quantitative PCR (qPCR) analyzes were conducted to estimate concentrations of bacteria community harboring specific catabolic nitrifying-ammonium monooxygenase (amoA), and denitrifying nitrate- (narG), nitrite- (nirS and nirG), nitric oxide- (norB) and nitrous oxide reductases (nosZ) genes. NH3-N, N2O-N, N2-N emissions represented 15.4 ± 1.9%, 5.4 ± 0.9%, and 79.1 ± 2.0% of the total nitrogen losses, respectively. Among the genes tested, temporal distribution of narG, nirS, and nosZ concentration correlated significantly (p<0.05) with the estimated N2 emissions. Denitrifying catabolic gene ratio (cnorB+qnorB)/nosZ ≥ 100 was indicative of N2O emission potential from the compost pile. Considering our current empirical limitations to accurately measure N2 emissions from swine slurry composting at field scale the use of these catabolic genes could represent a promising monitoring tool to aid minimize our uncertainties on biological N mass balances in these systems.

A socio-technical approach for improving a Brazilian shoe manufacturing system.

UNLABELLED: This article presents a macroergonomic intervention in a footwear company in Rio Grande do Sul, Brazil, to improve both the quality of life of the employees and productivity by optimizing the traditional Taylor/Ford work organization. Multi-functionality and team working were implemented as means of making tasks more flexible and richer and the working hours were changed. The results showed a reduction in human and material resource costs and a consequent improvement in health and workers quality of life. Although middle managerial staff displayed strong resistance to the project and to breaking traditional production paradigms, the socio-technical system has been implemented throughout the plant and is expected to end up becoming the benchmark for other companies in the sector. KEYWORDS: Macro-ergonomics, footwear industry, organization work.

Molecular aspects involved in swimming exercise training reducing anhedonia in a rat model of depression.

Patients suffering from depression frequently display hyperactivity of the hypothalamic-pituitary-adrenal axis (HPA) resulting in elevated cortisol levels. One main symptom of this condition is anhedonia. There is evidence that exercise training can be used as a rehabilitative intervention in the treatment of depressive disorders. In this scenario, the aim of the present study was to assess the effect of an aerobic exercise training protocol on the depressive-like behavior, anhedonia, induced by repeated dexamethasone administration. The study was carried out on adult male Wistar rats randomly divided into four groups: the "control group" (C), "exercise group" (E), "dexamethasone group" (D) and the "dexamethasone plus exercise group" (DE). The exercise training consisted of swimming (1 h/d, 5 d/wk) for 3 weeks, with an overload of 5% of the rat body weight. Every day rats were injected with either dexamethasone (D/DE) or saline solution (C/E). Proper positive controls, using fluoxetine, were run in parallel. Decreased blood corticosterone levels, reduced adrenal cholesterol synthesis and adrenal weight (HPA disruption), reduced preference for sucrose consumption and increased immobility time (depressive-like behavior), marked hippocampal DNA oxidation, increased IL-10 and total brain-derived neurotrophic factor (BDNF; pro-plus mature-forms) and a severe loss of body mass characterized the dexamethasone-treated animals. Besides increasing testosterone blood concentrations, the swim training protected depressive rats from the anhedonic state, following the same profile as fluoxetine, and also from the dexamethasone-induced impaired neurochemistry. The data indicate that physical exercise could be a useful tool in preventing and treating depressive disorders.