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Biomedical subjects

O Gökçe

Publications and source records attributed to O Gökçe.

10 recordsLinked to original sources

The oxidative effect of prolonged CO2 pneumoperitoneum on renal tissue of rats.

BACKGROUND: Despite its advantages, laparoscopic donor nephrectomy is associated with prolonged operation time, which could potentially increase oxidative stress in the graft. We performed the first experimental, randomized, controlled study with blind assessment of outcome to address this possibility. METHODS: Wistar-Albino rats were randomized into three groups. The animals in the control group were subjected to a sham operation under anesthesia; the animals in the other two groups were subjected to CO(2) pneumoperitoneum (Pp) for 120 and 240 min, respectively. The kidneys were removed at the end of each experiment. The concentrations of protein carbonyl and sulfhydryl (SH) groups and the activities of superoxide dismutase (SOD) were measured in renal tissue samples as markers of oxidative stress. Renal tissue samples were also evaluated histopathologically using light microscopy. RESULTS: Exposure to 120 min of Pp significantly increased the finding of oxidative stress in renal tissue samples, with an increase in protein carbonyl content and a decrease in protein sulfhydryls and tissue (SOD) activities. When exposure to Pp was prolonged from 120 min to 240 min, Pp associated oxidative stress was found to be increased. These changes occurred in the absence of light microscopical evidence of overt tissue damage. CONCLUSIONS: In an experimental model resembling laparoscopic donor nephrectomy, we found that exposure of pneumoperitoneum prolonged from 120 min to 240 min acts as an additive factor with respect to causing increased oxidative stress in renal tissue. Because these effects imply subtle tissue injury that may contribute to the chronic demise of renal grafts obtained laparoscopically, avoiding the use of Pp if possible and keeping operation time less than 120 min during laparoscopic donor nephrectomy appear to be advisable.

Animals↗

Use of random urine samples to estimate total urinary calcium and phosphate excretion.

Calcium-to-creatinine and phosphate-to-creatinine ratios in random single-voided urine specimens were compared with 24-hour calcium and phosphate excretions, respectively, in 67 subjects who were selected prospectively to represent a wide range of renal and parathyroid function as well as urinary calcium and phosphate loss. Simple linear regression analysis revealed significant correlation between the spot urine calcium-to-creatinine ratio and 24-hour total calcium excretion and between the spot urine phosphate-to-creatinine ratio and 24-hour phosphate excretion. Calculating these simple ratios permits easy, rapid, correct, and inexpensive estimation of the daily urinary calcium and phosphate excretion.

Adolescent↗

Povidone-iodine in experimental peritoneal hydatidosis.

The effect of polyvinylpyrrolidone-iodine (PVP-I) on experimental peritoneal hydatidosis was evaluated in this randomized blind controlled study. Seventy-five white, 3-month-old rats were subjected to laparotomy. After the intraperitoneal inoculation of viable scolices, the rats were randomly divided into three groups. Their peritoneal cavities were irrigated with either 1 per cent PVP-I solution (the PVP-I group), hypertonic saline (the HS group) or Ringer's lactate (the control group). Each group was assigned a separate code number; observers blind to the meaning of the code numbers noted all findings during a period of 4 months, after which the rats were killed to allow assessment of the abdominal cavity. The results were decoded after the statistical analyses were completed. The incidence of peritoneal cysts was found to be lower (8.7 per cent) in the PVP-I group compared with the HS (50 per cent) and control (90.9 per cent) groups; the mean number of hydatid cysts per animal was also lower in the PVP-I group compared with the other two groups. We conclude that the scolicidal activity of PVP-I is significantly higher than that of hypertonic saline and that it can be employed as a prophylactic agent against peritoneal hydatidosis.

Animals↗

Pheochromocytoma presenting with headache, panic attacks and jaundice in a child.

Pheochromocytomas can mimic many unrelated diseases due to their various presenting signs; they are encountered very rarely in childhood. Recently, their neuropsychiatric aspects have become a subject of interest for many workers, but most of the findings reported previously have been observed in adults. We present a case report which is unique in that it concerns a child with pheochromocytoma and psychiatric findings consisting of depression and panic disorder, which were interpreted as being directly related to, since they disappeared after the removal of, the tumor. Depression was persistent and accompanied by a constricting-type headache, while panic disorder was acute and accompanied by a migraine-type headache. Another intriguing complication encountered in our case was jaundice; we considered that it could possibly have been due to an adverse effect of catecholamines on hepatocyte function. We conclude that a pheochromocytoma can be confused with neuropsychiatric disorders in children as well as in adults and that it should be considered in the differential diagnosis of such disorders.

Adolescent↗

Preventive effect of nicardipine on hyperplastic changes in venous bypass grafts.

Nicardipine is a relatively new calcium channel blocker with important properties that could result in attenuation of the adverse proliferative changes in autogenous vein bypass grafts. In this experimental, randomized, controlled study, the effect of nicardipine on the pathologic findings in aortoaortic bypass graft was assessed. Forty-two male rabbits (Orycytolagus cuniculus) were randomized to three groups: group 1 received nicardipine and groups 2 and 3 placebo for 4 weeks, after which an aortaortic bypass was realized with an autogenous inferior vena cava segment. During the following 4 weeks, groups 1 and 2 received nicardipine, and placebo was continued in group 3. The animals were sacrificed at the end of the study to permit removal and evaluation of the bypass grafts. The mean intimal and medial thickness values for groups 1 and 2 were lower than those for group 3, indicating that nicardipine has a significant preventive effect on the hyperplastic changes in venous bypass grafts compared to placebo. The mean intimal and medial thickness values of group 1 were also lower than those of group 2, and the differences carried statistical relevance, suggesting that the use of nicardipine before grafting could potentiate its protective effect. To provide stimulus for further research, an attempt is made to relate the hyperplasia-preventing effect of nicardipine to possible mechanisms.

Animals↗

Calcium oxalate crystals in benign cyst fluid from the breast. A case report.

BACKGROUND: Two types of calcification have been observed in breast lesions. The more common is composed mostly of calcium phosphate and is detected in routine histologic tissue sections of frequently malignant lesions. The rare type is calcium oxalate and is found exclusively in benign cysts. CASE: In a 47-year-old female, strongly birefringent polyhedral crystals of calcium oxalate were detected in benign breast cyst fluid. CONCLUSION: Calcium oxalate is not clearly visible on routine histologic sections, and examination of the cytologic specimens under polarized light reveals them. Awareness of this potential pitfall might lead to conservative management.

Biopsy↗