Mete Koksal

No increase in sperm DNA damage and seminal oxidative stress in patients with idiopathic infertility

The most common cause of male infertility is idiopathic. Standard investigations reveal no abnormality in such cases. The aim of the study was to investigate the levels of sperm DNA damage and seminal oxidative stress and their relationships with idiopathic infertility. The study included 30 normozoospermic infertile men seeking infertility treatment and 20 fertile donors. Semen analysis was performed according to the World Health Organization guidelines. Sperm DNA damage was assessed by alkaline single cell gel electrophoresis (comet assay) after preparation with two-step discontinuous Percoll gradient. Seminal oxidative stress was measured by a novel automated method. DNA damage score, total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI) were not different in idiopathic infertile men compared with controls. No correlations were also found between DNA damage score and TAS, TOS levels and OSI in idiopathic infertile group. We did not find any relationship between sperm DNA damage and oxidative stress in normozoospermic infertile men. We think that the pathophysiology of idiopathic infertility cannot be explained by sperm DNA damage or seminal oxidative stress.

Rectal and vaginal administration of insulin–chitosan formulations: An experimental study in rabbits

Insulin is a polypeptide drug and it is degraded by gastrointestinal enzymes, therefore, it cannot be used via oral route readily. There are only parenteral forms available in the market. The aim of this study was to investigate the effect of rectal and vaginal administration of various insulin gel formulations on the blood glucose level as alternative routes in rabbits. Chitosan gel (CH-gel) was used as a carrier; the penetration enhancing effect of sodium taurocholate and dimethyl-β-cyclodextrin (DM-βCD) was also investigated. CH-gel provided longer insulin release. The maximum decreasing effect on blood glucose level was observed with insulin–CH-gel containing 5% DM-βCD. In conclusion, our results indicate that insulin may penetrate well through the rectal and vaginal mucosae from the CH-gel. DM-βCD was also found to be a useful agent to enhance the penetration of insulin through rectal and vaginal membranes.

Melatonin improves methanol intoxication‐induced oxidative liver injury in rats

Abstract:  This study was performed to evaluate the effect of melatonin on methanol‐induced liver injury. We evaluated the levels of malondialdehyde (MDA), protein carbonylation (PC), myeloperoxidase (MPO) activities and to assess lipid peroxidation, protein oxidation, neutrophil accumulation and nitrite which is a stable end product of nitric oxide respectively. We also studied superoxide dismutase, catalase, and glutathione peroxidase activities of liver tissue to evaluate the changes in the antioxidant status. Histopathological alterations were also determined. The experiment was performed on Wistar rats, which received intragastric 3 g/kg methanol as a 50% solution in isotonic saline once. After 6 and 24 hr all the drug received and intoxicated rats were killed under anesthesia. Pretreatment with melatonin (10 mg/kg) decreased the MDA levels significantly, restored the PC levels to the control, prevented the increase of nitrite level and MPO activity significantly and reversed to the control levels, prevented the reduction in all of the antioxidant enzyme activities. Additionally in melatonin treated group piecemeal necrosis, lobular lytic necrosis, and portal inflammation returned to normal histologic appearances when compared with methanol administration. In conclusion, melatonin has protective effects against methanol‐induced hepatic injury.

Effect of lycopene on caspase-3 enzyme activation in liver of methanol-intoxicated rats: comparison with fomepizole.

Lycopene is one of the major carotenoids and is found almost exclusively in tomatoes and tomato products. This study was performed to evaluate the effect of lycopene on methanol-induced liver injury and to compare the results with those after fomepizole, which is used in treatment of methanol intoxication. Experiments were carried out with 30 female Wistar rats weighting 180-200 g. Rats were injected with a intraperitoneally dose of 3 g/kg methanol as a 50% solution in isotonic saline once for intoxication. Rats were pretreated with fomepizole (50 mg/kg) and/or lycopene (10 mg/kg) before methanol. After 24 hours all the drug-treated and intoxicated rats were sacrificed under anesthesia. Malondialdehyde (MDA) levels were determined in order to assess lipid peroxidation, and caspase-3 activity was determined by immunostaining of liver tissues to evaluate apoptosis. Methanol administration significantly increased the MDA level and caspase-3 activity in liver. Pretreatment with lycopene and/or fomepizole decreased the MDA levels significantly. Similarly, lycopene and fomepizole decreased methanol-induced caspase-3 activity. The findings of the present study demonstrate that methanol intoxication causes hepatic toxicity in rats and that this is likely a result of reactive oxygen species and apoptosis induction. Lycopene has protective effects against methanol-induced hepatic injury similar to fomepizole. It was demonstrated for the first time that both lycopene and fomepizole prevent methanol-induced hepatic injury by reducing the increase of lipid oxidation and caspase-3 activation.

Ultrastructure of the thymus in diabetes mellitus and starvation

IntroductionThe purpose of this study was to investigate the ultrastructural change of the thymus under stress conditions created by diabetes accompanied by fasting, and also the effects of insulin therapy.MethodsForty-eight Sprague-Dawley type rats were used in this experiment. Type 1 diabetes symptoms were induced in 24 of the rats by the application of a single dose of intravenous streptozotocin in sodium citrate buffer through the tail vein. A single dose of sodium citrate buffer was given to rats to create a control group. Following the infusions, rats were divided into control, control and fasting, diabetes, diabetes and fasting, and insulin treatment groups. At the end of the experiment tissues from the thymus of the rats were extracted and examined using electron microscopy.ResultsSevere degeneration was observed in the prolonged fasting (stress) and diabetes groups without insulin treatment. Insulin treatment was found to mostly reverse this degeneration.ConclusionThis study demonstrates that the thymus was affected ultrastructurally by diabetes and concomitant fasting, and insulin treatment can reverse these changes.

ULTRASTRUCTURE OF RAT PUP'S PURKINJE NEURONS WHOSE MOTHERS WERE EXPOSED TO ETHANOL DURING PREGNANCY AND LACTATION

This study was intended to investigate the effects of alcohol on the ultrastructure of fetal cerebellar Purkinje cells. Twelve adult female rats of Sprague-Dawney species were utilized. Control and experiment groups were formed. Rats were made pregnant. Rats in experiment group were administered liquid diet containing 6% alcohol. Cerebellums of infant rats were taken on 6th, 8th, and 10th days after birth. For electron microscopy, tissue sections were processed and stained with the usual methods. When control and experiment groups were compared for electron microscopic investigation, degeneration of mithocondriaas cristolysis, dilatations of rough endoplasmic reticulum tubuli, and ring-shaped appearance of Golgi apparatus unit were determined. In some groups, nuclear membrane disintegrated. In cytoplasms of Purkinje cells, multivesicular bodies were distinguished. It was determined that liquid diet containing 6% alcohol had toxic effects on Purkinje cells and caused ultrastructural signs of degeneration in these cells.

Does moxifloxacin alter oxidant status in the cornea? An experimental study

Abstract Objective: In this experimental study, we investigated the possible effects of intracameral moxifloxacin on oxidative stress parameters and endothelial cell morphology in corneal tissue. Methods: In total, 30 rats were randomly assigned to three groups of 10 rats: the sham group (Group 1, n = 10); the control group (Group 2), where balanced salt solution (BSS) was administered at a dose of 0.01 cc (n = 10); and the treatment group (Group 3), where moxifloxacin was administered at a dose of 0.05 mg/0.01 cc (n = 10). Total antioxidant status (TAS) and total oxidant status (TOS) in corneal tissue and blood samples were measured and the oxidative stress index (OSI) was calculated. Also, corneal tissue histopathology was evaluated with caspase-3 and caspase-8 staining. Apoptotic activity was also evaluated. Results: In blood samples, TAS, TOS, and OSI levels were not statistically significantly different (all p > 0.05). Compared with the sham and control groups, TOS and OSI levels in cornea tissue were significantly different in the moxifloxacin group (all p < 0.05). However, compared with the control group, no statistically significant difference was found in the sham group (all p > 0.05). Compared with the sham and control groups, apoptotic activity was higher in the moxifloxacin group, in both immunohistochemical staining for caspase-3 and caspase-8. Conclusions: Intracameral moxifloxacin injection seems to be safe systemically, but it may have toxic effects on corneal tissues, as suggested by oxidative stress parameters and a histopathological evaluation.