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Biomedical subjects

O Kontaş

Publications and source records attributed to O Kontaş.

16 recordsLinked to original sources

Evaluation of contralateral testicular damage after unilateral testicular torsion by serum inhibin B levels.

BACKGROUND/PURPOSE: It is still controversial whether unilateral testicular torsion (TT) affects contralateral testis. The authors wanted to evaluate contralateral testicular damage in a rat model by the serum inhibin B levels, which is suggested as a marker of Sertoli cell function and spermatogenesis. METHODS: Fifty peripubertal male Wistar Albino rats were divided into 5 groups each containing 10 rats. Surgery was conducted under intraperitoneal 1-shot ketamine (50 mg/kg) anesthesia. Torsion-detorsion, torsion-detorsion-orchiectomies, orchiectomies, and sham operations were performed on the right testicle through a midline incision. Torsions were created by rotating the right testes 720 degrees in a clockwise direction and maintained by fixing the testes to the scrotum with a silk suture. Torsion duration was 4 hours. After each surgical intervention the incisions were closed. In group 1, 3-mL blood samples were taken to determine basal values of inhibin B in serum, and bilateral orchiectomies were performed. In group 2, 4 hours of torsion and detorsion was created and 1 month later, 3-mL blood samples were taken, and bilateral orchiectomies were performed. In group 3, 4 hours of torsion-4 hours of detorsion was created, and right orchiectomies were performed and 1 month later, 3-mL blood samples were taken and contralateral orchiectomies were added. In group 4, unilateral orchiectomies were performed, and 1 month later, 3-mL blood samples were taken, and contralateral orchiectomies were added. After the measurement of the serum inhibin B levels and histopathologic examinations, results are expressed as mean +/- SD. RESULTS: Serum inhibin B levels expressed as mean +/- SD were 108.233 +/- 21.296 pg/mL for group 1, 54.065 +/- 16.910 pg/mL for group 2, 74.195 +/- 2.779 pg/mL for group 3, 108.335 +/- 26.078 pg/mL for group 4, and 107.645 +/- 4.705 pg/mL for group 5. Inhibin B levels in group 2 and group 3 were different from group 1, group 4, and group 5 (P <.05). In histologic examination, Johnsen's scores expressed as mean +/- SD of right testes were 9.74 +/- 0.08 for group 1, 3.64 +/- 3.36 for group 2, and 9.86 +/- 0.05 for group 5. Histologic findings in group 2 were different from group 1 and group 5 (P <.05). Johnsen's scores expressed as mean +/- SD of left testes were 9.78 +/- 0.09 for group 1, 9.75 +/- 0.14 for group 2, 9.76 +/- 0.15 for group 3, 9.79 +/- 0.07 for group 4, and 9.82 +/- 0.08 for group 5, and there was no difference between groups (P >.05). CONCLUSIONS: The serum inhibin B levels decrease after unilateral TT reflecting contralateral testicular damage. Orchiectomy to prevent contralateral testicular damage after TT may not be effective after critical period. Measurement of inhibin B levels to evaluate contralateral testicular damage after unilateral TT is more effective than histopathologic examination.

Animals↗

Cohen syndrome with acanthosis nigricans and insulin resistance.

Cohen syndrome is a rare genetic disorder consisting of truncal obesity, hypotonia, mental retardation, microcephalia, characteristic facial appearance and ocular anomalies. Other diagnostic clinical features include narrow hands and feet, low growth parameters, neutropenia and chorioretinal dystrophy. Acanthosis nigricans is a cutaneous disorder characterized by hyperpigmentation and papillomatosis. Syndromal acanthosis nigricans may occasionally appear as a feature of several specific syndromes. We report a patient showing the typical characteristics of Cohen syndrome with acanthosis nigricans and hyperinsulinemia.

Acanthosis Nigricans↗

Therapeutic effect of tirilazad mesylate (U-74006F), mannitol, and their combination on experimental ischemia.

The effect of tirilazad mesylate (U-74006F), mannitol, and their combination was investigated on focal cerebral ischemia induced by permanent middle cerebral artery (MCA) occlusion in rabbits. Rabbits were divided into four groups receiving vehicle, U-74006F, mannitol, and U-74006F plus mannitol. Hematocrit (hct), glucose, mean arterial blood pressure (MABP), pH, PCO2, and PO2 were measured both before and after occlusion. Seventy-two hours following the permanent MCA occlusion, the neurological outcome was assessed and a quantitative neuropathologic examination was performed in all rabbits. The neurological outcome was better in the rabbits treated with U-74006F plus mannitol than in the other groups. The size of infarction of the affected hemisphere following MCA occlusion was 49.7% in the control group, 30.6% in the U-74006F group, 47.6% in the mannitol group, and 24.1% in the U-74006F plus mannitol group. There was a statistically significant reduction in infarct size in the U-74006F plus mannitol group compared with the other groups (P < 0.05). The ratio of ischemic neurons to total neurons in the cortex was smaller in the U-74006F plus mannitol group than in the other groups. The ratio of ischemic neurons to total neurons in the subcortex was significantly lower in the U-74006F plus mannitol group than in the other groups (P < 0.05). Our data provide evidence for the beneficial effects of both U-74006F and U-74006F plus mannitol in promoting neurological recovery and preservation of the ischemic area.

Animals↗

Detection of intestinal bacterial translocation in subclinical ischemia-reperfusion using the polymerase chain reaction technique.

BACKGROUND/PURPOSE: The purpose of this study was to evaluate the detection of bacterial translocation after subclinical ischemia reperfusion injuries in rats with the polymerase chain reaction (PCR) technique. METHODS: Six-week-old weaning rats were divided into 3 groups. (1) Experiment rats (n = 20) were gavaged with 10(10) Escherichia coli followed by superior mesentery artery occluded for 10 minutes, then reperfused for 30 minutes. (2) Control rats (n = 20) received bacterial gavage. (3) Group 3 were sham rats (n = 20). After the procedure, 3 mL of blood was obtained from the portal vein. The terminal ileum and mesenteric lymph node (MLN) near the terminal ileum were removed. E. coli DNA was detected in blood and MLN samples by PCR, and histological changes were examined. RESULTS: E. coli DNA detection in ischemia-reperfusion (I/R) group animals was 6 of 20 (30%) in the MLN and 2 of 20 (10%) in the blood. PCR was negative in all the rats in the control group and in the sham group (P < .05). There were no significant differences in the histological examination of rat intestines. CONCLUSION: These data suggest that subclinical intestinal I/R injury results in bacterial translocation. Also, PCR is a highly sensitive and rapid method to detect the presence of microbial DNA.

Animals↗

A new subtype of meningioma.

Three patients with small meningiomas presented with diffuse cerebral edema that was out of proportion to the size of tumors. All lesions were small and no brain invasion or unusual tumor vascularity or dural sinus involvement was noted in any of the three cases. Tumor material was subjected to conventional and immunohistochemical stains. All three tumors showed benign meningothelial components, prominent formation of hyaline inclusions (pseudopsammoma bodies), and striking vascular mural proliferation of small dark cells. All patients have remained asymptomatic without any evidence of tumor recurrence after a follow-up of 4-6 years. These tumors showed proliferation of pericytes in blood vessel walls and, therefore, represent a new subtype of meningothelial meningioma. In the study presented here, the location, size, histotype, and clinical findings that may influence the development of peritumoral brain edema are discussed in detail.

Adult↗

Burn scar sarcoma.

Malignancies developing in burn scars have been known for a long time and are generally epidermoid carcinomas although a few sarcoma cases have been reported. A case of fibrosarcoma developing in the burn scar was presented in this report and the literature reviewed.

Adult↗

Protective effect of magnesium supplementation on experimental 3-methyl cholanthrene-induced fibrosarcoma and changes in tissue magnesium distribution during carcinogenesis in rats.

In this study, we wanted to examine the effect of magnesium (Mg2+) supplementation on the experimental 3-methyl cholanthrene (3-MC)-induced fibrosarcoma and alterations in (Mg2+) distribution in several tissues of the rats, during carcinogenesis. It was determined that serum and tissue (Mg2+) levels of the rats in (Mg2+)-supplemented diet group were higher than those of the rats in the (Mg2+)-nonsupplemented and control groups. The mean time of fibrosarcoma development for (Mg2+)-supplemented group was longer than (Mg2+)-nonsupplemented group (p < 0.05). Symptoms of hypermagnesemia were not observed in any of the rats. These results suggests that dietary (Mg2+) supplementation may have a partial anti-carcinogenic effect on experimental 3-MC-induced fibrosarcoma by prolongation of the latent period of carcinogenesis.

Animals↗

Scintigraphic visualization of ocular melanoma with Tc-99m glutathione.

In a patient with ocular melanoma scintigraphy obtained with 99mTc-GSH clearly demonstrated the histologically proven ocular lesion both in planar and SPECT images. 99mTc-sestamibi study obtained in the same patient three days later was negative. 99mTc-GSH is a potential alternative to the currently used radiopharmaceuticals for imaging both cutaneous and ocular melanomas and their metastases.

Eye Neoplasms↗

A model of hypoxia-induced necrotizing enterocolitis: the role of distension.

BACKGROUND/PURPOSE: This study was performed to investigate additional effects of intestinal distension in the damage to the gut caused by hypoxia-reperfusion. METHODS: Five groups each consisting of ten 1-day-old Wistar albino rat pups were studied; Group 1, hypoxia-reoxygenation; Group 2, hypoxia-reoxygenation and distension; Group 3, distension and hypoxia-reoxygenation; Group 4, distension; and Group 5, control. Hypoxia was induced by placing the rat pups in a 100% carbon dioxide chamber for 5 minutes. After the hypoxia, the pups were exposed to 100% oxygen for reoxygenation for 5 minutes. The intestinal distension was carried out with a fine 21-gauge SILASTIC cannula via rectal route. The rats were killed on the third day, and all the intestine were harvested from duodenum to sigmoid colon. Malondialdehyde (MDA) levels were determined as an index of lipid peroxidation related to free radical reaction in the intestine. The histopathologic investigation was carried out by light microscopy in a blinded fashion. RESULTS: The MDA levels of Group 3 animals were significantly higher than those in Group 1, 4, and the control group (P < .05). The MDA level of Group 2 did not differ significantly from that of the Group 3 (P > .05). All MDA levels of the study groups also were significantly higher than the control group (P < .05). CONCLUSION: The results demonstrated that intestinal distension increased the damaging effects of hypoxia-reoxygenation in the gut.

3,4-Methylenedioxyamphetamine↗

Effects of angiotensin converting enzyme inhibitor cilazapril and angiotensin II antagonist saralasin in ovarian hyperstimulation syndrome in the rabbit.

We investigated the possible effects of the angiotensin converting enzyme (ACE) inhibitor cilazapril and angiotensin II antagonist saralasin on ovulation, ovarian steroidogenesis and ascites formation in the ovarian hyperstimulation syndrome (OHSS) in the rabbit model. OHSS was induced in rabbits by human menopausal gonadotropin (hMG) and intermittent human chorionic gonadotropin (hCG). In the cilazapril group (n = 10), animals also received cilazapril 2 mg/kg intraperitoneally daily for 7 days. In the saralasin group (n = 8), animals received saralasin intraperitoneally 1 h before or 1 h after hCG administration. Control animals (n = 8), received intraperitoneal saline solution. Serial blood samples were drawn on days 1, 5, 7 and 9 to measure serum estradiol and progesterone levels. On day 9, all rabbits underwent surgical exploration. Peritoneal and pleural fluid formation, ovarian weights and number of ovulations were determined. The volume of the ascitic and pleural fluids after hyperstimulation were not statistically different between the control, cilazapril and saralasin groups. The weight gains and ovarian weights of animals were similar between treatment and control groups. Saralasin significantly (p < 0.05) inhibited ovulation, but cilazapril did not. Cilazapril and saralasin did not affect progesterone production. Only cilazapril significantly decreased estradiol production (p < 0.05). In conclusion, the ACE inhibitor cilazapril and angiotensin II antagonist saralasin did not prevent ascites formation in OHSS. The ovarian renin-angiotensin system may not be the only factor acting in ascites formation in the OHSS.

Angiotensin II↗

Cranioplasty with bone flaps preserved under the scalp.

Cranial bone defects in 27 patients were repaired with bone flaps preserved under the scalp. Head trauma (thirteen patients), cerebrovascular disorder (five patients), postoperative brain swelling (seven patients), and cerebral infective disease (two patients) accounted for the cranial defects. The bone flaps are reimplanted after 14-98 days. The follow-up period was 6 to 26 months. We have encountered no complications related to this technique in 27 consecutive cases.

Adolescent↗

Fibrin glue and conventional sutured vasal anastomosis in the rat.

The present study was undertaken to evaluate the use of fibrin glue (Tisseel, Immune U.S., Inc) for vasovasostomy and to compare this technique to conventional sutured vasovasostomy. Thirty immature Sprague-Dawley rats, weighing from 60 to 80 g, were used in this study. A conventional one-layer sutured anastomosis (Ethilon 10-O) in 10 rats was compared to a fibrin glue technique of vasal anastomosis (10 rats). The fibrin glue technique was performed without sutures and was unstented. The biological glue was utilized to seal both ends of the vas. The contralateral vas was ligated with 5-O prolein. In the control group (10 rats) the left vas was ligated in the same way, and only the contralateral vas was explored. After 2 months, one male and two female rats were placed in a cage for a further 2 months. At the end of this period, the fertility rate was 80% (n = 8) of the control group, 60% (n = 6) of the conventional anastomosis, and 70% (n = 7) of fibrin glue groups, respectively. The testes and vasal specimens were evaluated for the presence of sperm granuloma, and histologic studies were performed. The incidence of sperm granuloma after vasovasostomy was 20% (n = 2) for the fibrin glue group and 30% (n = 3) for the sutured group. The sperms were seen in the proximal and distal side of the vasal anastomosis in 10 rats in the control group, in 8 in the glue group, and in 8 in the conventional sutured anastomosis group.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗

Hypoxia-induced necrotizing enterocolitis in the immature rat: the role of lipid peroxidation and management by vitamin E.

The authors developed an experimental model of necrotizing enterocolitis (NEC) by hypoxia-reoxygenation, and determined the content of malondialdehyde levels as an index of lipid peroxidation, related with a free-radical reaction in the gastrointestinal tract of newborn rats. They also investigated the role of vitamin E, an antioxidant, in this free-radical injury. The study was performed on 1-day-old rats. The 30 rat pups were divided into three groups. Hypoxia was induced by placing the pups in a 100% carbon dioxide chamber for 5 minutes. The pups were reoxygenated with 100% oxygen for 5 minutes. Group 1 (n = 10) was subjected to hypoxia-reoxygenation and killed 3 days after hypoxia. Group 2 (n = 10) was subjected to hypoxia-reoxygenation and treated with vitamin E (30 IU/kg/d intraperitoneally) for the next 3 days, and killed. Group 3 (n = 10) rats served as controls. The histopathology of the intestinal lesions in group 1 animals was characteristic of ischemic injury and ranged from superficial epithelial damage with villous shortening to transmural necrosis. In the vitamin E-treated animals these lesions were milder. The malondialdehyde levels of group 1 were significantly higher than those of the other two groups (P < .001). This study shows that oxidant-mediated lipid peroxidation injury plays a central role in mediating hypoxia-induced intestinal necrosis and suggests that vitamin E may play a therapeutic role in NEC.

Animals↗

Ectopic adrenal tissue in the inguinal region in children.

Adrenal rests are common in children and are most often found as bright yellow, retroperitoneal nodules from the diaphragm to the pelvis. They are usually incidental findings during surgery. In a 12-month period, 268 children, 18 days to 15 years (mean 3.2 years) of age, underwent 304 operations for common inguinoscrotal disorders at the Department of Pediatric Surgery, Erciyes University Medical School. There were 252 males and 16 females, (M/F 15.7:1). Ectopic adrenal tissue was found in nine males (3%). This report concerns the incidence and structure of aberrant adrenal tissue found in children during inguinoscrotal operations, including its embryology, histology, and clinical implications.

Adolescent↗