The use of metal devices in medical application is increasing but it remains incompletely understood the physiological effects of component degradation. Niobium (Nb) alloys have already been investigated in the 1980's and recent studies demonstrated the potential of Nb as an implant material. The purpose of this study was to determine cytotoxic, hematologic and histologic effects of niobium in Swiss mice. Animals were treated with a single dose of 3 % niobium oxide (Nb2O5) diluted in PBS, i.p. Cytotoxic assay, hematologic and histologic evaluation were done 3, 7 and 12 days after niobium treatment. Data have shown increased number of cells after niobium treatment, but there was no difference in cell viability. Furthermore, it was not observed hematological modification 3, 7 or 12 days after niobium treatment. Despite the fact that animals treated with niobium for 3 and 7 days showed mild degeneration in hepatocytes, mice kept alive for 12 days showed liver cells regeneration. Our results suggested that niobium cytotoxicity was not progressive because 12 days after treatment there was an evident liver regeneration. Data obtained indicated that niobium may be promising alternatives to biomedical applications.

Introduction Menopausal women have an increase deposition of body fat and changes in the lipid profile, being especially susceptible to cardiovascular diseases, and type 2 diabetes. However, physical activity can mitigate this situation. Thus, the aim of the present study is to evaluate the effects of moderate aerobic exercise on visceral adipose tissue (VAT) of female LDL-receptor knockout ovariectomized mice. Methods We used 48 animals, divided into six groups (n = 8/per group): sedentary control (SC), sedentary ovariectomized control (SCO), trained ovariectomized control (TCO), sedentary non-ovariectomized LDL-receptor knockout (KS), sedentary ovariectomized LDL-receptor knockout (KOS), and trained LDL-receptor knockout ovariectomized (KOT). We analyzed the VAT through morphometric and stereological parameters in hematoxylin and eosin stained sections. Additionally, we evaluated biochemical parameters as glucose, triglycerides, and total cholesterol. Finally, immunohistochemical techniques for matrix remodeling, inflammation, apoptosis, and oxidative stress were evaluated. Results We observed that menopause is related to increased visceral adiposity, inflammation, oxidative stress, macrophages activity, serum levels of glucose, triglycerides, and total cholesterol. However, exercise was effective in reducing these parameters, as well as being associated with increased vascularization of VAT and interstitial volume density. Conclusions Moderate exercise is a key factor in mitigating the effects of dyslipidemia in estrogen deprivation. However, further studies are needed to corroborate with our findings.