Effect of selenite treatment on ultrastructural changes in experimental diabetic rat bones

It is known that streptozotocin (STZ)-induced diabetes causes functional and structural alterations in some types of tissue and organ. A number of methods have been used to characterize the properties of diabetic tissues and their diagnosis. Selenium compounds, playing an antioxidant role, can restore some altered metabolic parameters and diminished functions in experimental diabetes. The first aim of the present study was to investigate the effects of STZ-induced diabetes on structural properties of rat long bones. Electron and light microscopic observations showed deleterious alterations in the structure of the diabetic rat long bones, the most prominent effect being in osteocytic cells. Fine cytoplasmic processes of the osteocytes seemed to be shortened, and diabetes affected the normal cytoplasmic processes in a negative manner. The second aim of the present study was to evaluate the effects of sodium selenite treatment for 4 wk on the long bones of the diabetic rats. Electron and light microscopic observations demonstrated that sodium selenite treatment prevented the STZ-induced structural as well as ultrastructural changes in the long bones of the rats. In conclusion, this study first showed that a period of 5-wk diabetes was enough to cause some important and degenerative changes in the structure of the bone tissues, and, second, it demonstrated that sodium selenite treatment of the diabetic rats could normalize these alterations.     

Effects of captopril and losartan on lipid peroxidation,protein oxidation and nitric oxide release in diabetic rat kidney

Increased oxidative stress has an important role in the pathogenesis of diabetic nephropathy. The aim of this study was to evaluate the effects of renin-anigiotensin system blockage, either by angiotensin-converting enzyme inhibition or angiotensin receptor blockage, on oxidative stress and nitric oxide release in diabetic rat kidneys. After induction of diabetes, six rats were given captopril, six rats were given losartan, and six rats served as diabetic controls. Six healthy rats were also included. At the end of an 8-week period nitric oxide release, lipid peroxidation and protein oxidation were measured in kidney cortices, and urinary albumin excretion (UAE) was determined in 24-h urine samples. Losartan- and captopril-treated diabetic rats had lower levels of UAE than diabetic controls. Diabetic rats had higher levels of lipid peroxidation and protein oxidation compared to healthy rats. NO release was significantly lower in diabetic groups than healthy controls. UAE levels showed a positive correlation with lipid peroxidation and a negative correlation with NO release. Inhibition of lipid peroxidation could be one of the protective mechanisms of renin-angiotensin axis inhibition in diabetic kidney tissues.     

Respiratory syncytial virus inhibitors. Part 2: Benzimidazol-2-one derivatives

Structure-activity relationships for a series of benzimidazol-2-one-based inhibitors of respiratory syncytial virus are described. These studies focused on structural variation of the benzimidazol-2-one substituent, a vector inaccessible in a series of benzotriazole derivatives on which 2 is based, and revealed a broad tolerance for substituent size and functionality.     

Comparative investigation of kidney mesangial cells from increased oxidative stress-induced diabetic rats by using different microscopy techniques

High glucose and increased oxidative stress levels are the known important mediators of diabetic nephropathy. However, the effects of these mediators on tissue damage basically due to extracellular matrix expansion in mesangial cells have yet to be fully examined within the context of early stage diabetic nephropathy. In this study, we attempted to characterize changes in mesangial cells of streptozotocin-induced diabetic rats with a comparative investigation of kidney tissue by using different microscopy techniques. The serum levels of urea and creatinine of diabetic rats, as biomarkers of kidney degeneration, decreased significantly compared to those of age-matched controls. In diabetic rats, there are increased malondialdehyde and oxidized-glutathione levels as well as reduced-glutathione and glutathione-peroxidase activity levels in renal tissue compared to those of the controls. By using light and electron microscopies, we showed that there were marked thickening in Bowman’s membrane and glomerular capillary wall, increased amount of extracellular matrix often occupying Bowman’s space, degenerations in tubules, an increased number of mesangial cells in the network of glomerular capillary walls, and increased amount of lipid accumulation in proximal tubules in the renal tissue of diabetic rats. Our confocal microscopy data confirmed also the presence of irregularity and widened in glomerular capillaries, their attachment to the Bowman’s capsule, degenerated heterochromatin, thickening in foci of glomerular basement membrane, and marked increase in mesangial cells. These results suggest that a detailed structural investigation of kidney tissue provides further information on the important role of mesangial cells in pathogenesis of diabetic nephropathy.     

Alteration of thiol-disulphide homeostasis in acute tonsillopharyngitis

Objective: Thiol-disulphide homeostasis (TDH) has a critical role in various clinical disorders. We aimed to assess the association of TDH with acute tonsillopharyngitis (AT) in children.

Methods: This study included 94 (73 viral and 21 bacterial) tonsillopharyngitis patients and 88 control children. Their native thiol, total thiol, and disulphide levels were measured.

Results: Viral and bacterial tonsillopharyngitis patients had lower native thiol levels compared with healthy children (P?P?=?0.008, respectively). Both groups had lower total thiol levels compared with control children (P?=?0.002 for viral, P?=?0.011 for bacterial). The disulphide levels were lower in bacterial than in viral tonsillopharyngitis patients (P?=?0.04), and there was a significant difference between viral tonsillopharyngitis patients and the control group (P?P?P?=?0.017 for bacterial). The disulphide/native thiol and disulphide/total thiol ratios were significantly higher in viral (P?P?=?0.017 for both) than in healthy children. In all patients, a correlation was found between the levels of C-reactive protein (CRP) and native thiol (r?=??0.211, P?=?0.04), CRP and total thiol (r?=??0.217, P?=?0.036), white blood cell (WBC) and native thiol (r?=??0.228, P?=?0.002), WBC and total thiol (r?=??0.191, P?=?0.01), and WBC and disulphide (r?=?0.160, P?=?0.03).

Discussion: TDH is altered in AT in children. The alteration is more prominent in viral than in bacterial tonsillopharyngitis.     

Advanced fully integrated radiofrequency/optical-coherence-tomography irrigated catheter for atrial fibrillation ablation

The inability of current catheter ablation procedures to accurately monitor lesion formation limits their safety and efficacy. An advanced fully integrated radiofrequency (RF)/optical coherence tomography (OCT) ablation catheter is developed, which enables real-time monitoring during ablation. An OCT fiber array is especially designed, developed and integrated into an off-the-shelf irrigated RF ablation catheter. In-vitro experimental studies performed on poultry and ovine hearts demonstrate the ability of the integrated RF/OCT system to provide information on the quality and orientation of catheter/wall contact. Experimental results show that adipose tissue can be accurately identified from normal myocardial tissue with 94% accuracy and lesion formation is monitored with an overall accuracy of 93%. The ability to predict pop events is also demonstrated, with an accuracy of 86%.