SIRT6 expression and oxidative DNA damage in individuals with prediabetes and type 2 diabetes mellitus.

Sirtuins (SIRTs) is a family of NAD+ dependent histone deacetylases. SIRT6 takes play in glucose homeostasis, genomic stability and DNA repair. Although increased oxidative DNA damage and decreased DNA repair activity were determined in diabetes mellitus, the possible relation between level of oxidative DNA damage and SIRT6 expression has not been investigated so far. We determined SIRT6 expression and urinary 8-hydroxy deoxyguanosine (8-OHdG) levels, marker of oxidative DNA damage, in cases with prediabetes (PreDM) and type 2 diabetes mellitus (T2DM). SIRT6 gene expression was determined in peripheral blood leukocytes of 70 patients with type 2 diabetes, 50 cases in prediabetic stage and 40 healthy subjects. SIRT6 mRNA levels were determined by quantitive real time- polymerase chain reaction. SIRT6 protein was detected by immunocytochemical staining. Urinary 8-hydroxy deoxyguanosine (8-OHdG) levels were measured by ELISA. There was no significant difference between groups for SIRT6 mRNA level. SIRT6 immunopositivity in T2DM group was lower when compared to those in preDM group (P<0.05). SIRT6 positive cell number in T2DM and preDM groups were lower in comparison to control group (P<0.01 for both), however, when study groups were subdivided into two groups according to their age, the difference between preDM and control groups disappeared in both mid-aged and old-aged groups. The urinary 8-OHdG level was found to be higher in the T2DM group in comparison to preDM group (P<0.05). When age is taken into consideration, urinary 8-OHdG level in the T2DM group was found to be higher than those in both preDM and control groups in the old-aged cases but no significant difference was determined between groups in the mid-aged cases. There was no relation between SIRT6 expression and urinary 8-OHDG excretion. It was concluded that SIRT6 may take play in development of T2DM but this effect seems to be independent from repair of oxidative DNA damage.

COMPARISON OF FINASTERIDE, METFORMIN, AND FINASTERIDE PLUS METFORMIN IN PCOS.

The effects of finasteride on insulin resistance and of metformin on hyperandrogenism in patients with polycystic ovary syndrome (PCOS) are not clear. This study therefore compared the effects of finasteride, metformin, and finasteride plus metformin treatments on hormone levels, insulin resistance, and hirsutism score in women with PCOS. Fifty-two patients with PCOS were randomly assigned to receive finasteride 5 mg/day, metformin 1700 mg/day or finasteride plus metformin for 12 months. Body mass index (BMI), Ferriman Gallway score (FGS), serum concentrations of estradiol, sex hormone-binding globulin, free testosterone, dehydroepiandrosterone sulfate (DHEAS), androstenedione, and homeostasis model assessment of insulin resistance (HOMA-IR) index and areas under the curve (AUC) for insulin and glucose were evaluated before and after 12 months of treatment. Reductions in FGS, free testosterone, DHEAS, androstenedione, HOMA-IR, AUC-insulin, and AUC-glucose were significant within each group, whereas BMI and estradiol were not. Comparisons of changes in parameters in the 3 groups did not clearly show the superiority of any treatment modality. The treatment with finasteride alone significantly reduced both androgen levels and parameters of insulin resistance. In addition, metformin alone was effective, and not inferior to finasteride, in the treatment of hyperandrogenism.

A strategy for the control of catheter blockage by crystalline Proteus mirabilis biofilm using the antibacterial agent triclosan.

OBJECTIVES: Catheter blockage by crystalline Proteus mirabilis biofilm is a common complication in patients undergoing long-term indwelling bladder catheterisation. Previously we have shown that inflating the retention balloons of all-silicone catheters with triclosan solutions prevents the encrustation process. The aim of the present work was to examine whether this strategy is effective in latex-based catheters. METHODS: Laboratory bladder models were fitted with catheters and the retention balloons inflated with water or various concentrations of triclosan. The urine was inoculated with Pr. mirabilis and the times catheters took to block recorded. RESULTS: Control catheters blocked in mean times ranging from 18 to 27 h. The pH of the urine rose from 6.1 to >8.6. In models with latex-based catheters inflated with 1-10 mg/ml triclosan, the urinary pH was controlled, the numbers of organisms in the urine was reduced and the catheters drained freely for the 7 day experimental period. Electron microscopy confirmed that crystalline biofilm was blocking control catheters. Little sign of encrustation was visible on the test catheters. CONCLUSION: Inflating the retention balloons with triclosan could have practical applications in controlling encrustation on both latex and silicone-based catheters.