Melatonin protects against gentamicin-induced nephrotoxicity in rats

Acute renal failure is a major complication of gentamicin (GEN), which is widely used in the treatment of gram-negative infections. A large body of in vitro and in vivo evidence indicates that reactive oxygen metabolites (or free radicals) are important mediators of gentamicin nephrotoxicity. In this study we investigated the role of free radicals in gentamicin-induced nephrotoxicity and whether melatonin, a potent antioxidant could prevent it. For this purpose female Sprague-Dawley rats were given intraperitoneally either gentamicin sulphate (40 mg/kg), melatonin (10 mg/kg), gentamicin plus melatonin or vehicle (control) twice daily for 14 days. The rats were decapitated on the 15th day and kidneys were removed. Blood urea nitrogen (BUN) and creatinine levels were measured in the blood and malondialdehyde (MDA) and glutathione (GSH) levels, protein oxidation (PO) and myeloperoxidase (MPO) activity were determined in the renal tissue. Gentamicin was observed to cause a severe nephrotoxicity which was evidenced by an elevation of BUN and creatinine levels. The significant decrease in GSH and increases in MDA levels, PO and MPO activity indicated that GEN-induced tissue injury was mediated through oxidative reactions. On the other hand simultaneous melatonin administration protected kidney tissue against the oxidative damage and the nephrotoxic effect caused by GEN treatment.     

Erythrocyte antigen and reticulocyte engraftment after allogeneic hematopoietic stem cell transplantation

The aim of this study was to study the usefulness of erythrocyte antigen (EA) measurement to study engraftment after allogeneic HSCT. In all, 31 consecutive patients receiving HLA-identical bone marrow (BM) (n=13) or peripheral blood stem cells (n=18) were investigated. Apart from the ABO group, 15 EAs representing six minor blood groups were followed by the simple tube agglutination technique. A total of 20 (64.5%) patients received ABO-identical, eight (25.8%) received ABO minor and three (9.7%) received ABO major mismatched grafts. In all, 29 patients were followed for a median of 12 (6-16) months; 65% of the patients expressed donor type EA 1 month and almost all did so 6 months after transplant. Reticulocyte engraftment was significantly shorter than EA engraftment (median 18 vs 35 days) (P=0.001). Patients who received PB stem cells showed significantly faster EA and reticulocyte engraftment than patients who received BM stem cells (P=0.038 and 0.025). ABO compatibility did not have an impact on reticulocyte and EA engraftment (P=0.4 and 0.55). The earliest donor type EA detected was from the Rh and Kidd system. These data suggest that EA and reticulocyte assays are useful in monitoring engraftment.     

Effect of alpha-interferon therapy on bone marrow fibrosis in hairy cell leukemia

Iliac crest trephine biopsy specimens from 16 patients treated with recombinant alpha 2-interferon (alpha-IFN) for hairy cell leukemia (HCL) were examined for reticulin and collagen content. These data were compared with the hairy cell index (HCl), the proportion of hairy cells to the overall cellularity of the bone marrow. Specimens were studied immediately before alpha-IFN therapy, at 6-month intervals during, and in six patients 6 months after cessation of therapy. All patients presented with increased bone marrow fibrosis ranging from focally increased reticulin to a diffuse increase in both reticulin and collagen content. This fibrosis was observed to decrease during alpha- IFN therapy inasmuch as the hairy cell population was diminished in the bone marrow in 13 patients. Regression analysis of HCl v bone marrow fibrosis showed a positive correlation (r = .73, P less than .02). Six patients demonstrated a reduction in bone marrow reticulin and collagen to normal levels during alpha-IFN therapy. Two of six patients demonstrated increased bone marrow fibrosis and HCl 6 months after cessation of alpha-IFN therapy. Three of 16 patients exhibited no decrease in bone marrow reticulin content during therapy despite a decreased bone marrow hairy cell population.     

Low eradication rate of Helicobacter pylori with triple 7-14 days and quadriple therapy in Turkey

AIM:The eradication rate of Helicobacter pylori (H pylon) shows variation among countries and regimens of treatment.We aimed to study the eradication rates of different regimens in our region and some factors affecting the rate of eradication.METHODS:One hundred and sixty-four Hpylori positivepatients (68 males, 96 females; mean age:48±12 years)with duodenal or gastric ulcer without a smoking history were included in the study. The patients were divided into three groups according to the treatment regimens. Omeprazole 20mg, clarithromycin 500mg, amoxicillin 1g were given twice daily for 1 week (Group I) and 2 weeks (Group Ⅱ).Patients in Group Ⅲ received bismuth subsitrate 300mg,tetracyline 500 mg and metronidazole 500mg four times daily in addition to Omeprazole 20mg twice daily.Two biopsies each before and after treatment were obtained from antrum and corpus, and histopathologically evaluated.Eradication was assumed to be successful if no Hpylorus was detected from four biopsy specimens taken after treatment. The effects of factors like age, sex, Hpyloridensity on antrum and corpus before treatment, the total Hpylori density, and the inflammation scores on the rate of Hpylori eradication were evaluated.RESULTS:The overall eradication rate was 42%. The rates in groups Ⅱ and Ⅲ were statistically higher than that in group I (P<0.05). The rates of eradication were 24.5%,40.7% and 61.5% in groups Ⅰ, Ⅱ and Ⅲ, respectively. The eradication rate was negatively related to either corpus Hpylori density or total Hpyloridensity (P<0.05).The median age was older in the group in which the eradication failed in comparison to that with successful eradication (55yr vs 39yr, P<0.001). No correlation between sex and Hpylori eradication was found.CONCLUSION: Our rates of eradication were significantly lower when compared to those reported in literature.We believe that advanced age and high Hpyloridensity are negative predictive factors for the rate of Hpylorieradication.