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Ayşe Polat

Publications and source records attributed to Ayşe Polat.

10 recordsLinked to original sources
PubMed2006

Effects of trapidil on renal ischemia-reperfusion injury.

There is increasing evidence to suggest that reactive oxygen and nitrogen species play a role in the pathogenesis of renal ischemia-reperfusion (I/R) injury. This study was designed to determine the possible protective effects of trapidil treatment against oxidative and nitrosative tissue injury of kidney induced by I/R. A renal I/R injury was induced by a left renal pedicle occlusion by ischemia for 45 minutes, followed by 1 hour of reperfusion with contralateral nephrectomy in I/R and I/R + trapidil groups. Trapidil (8 mg/kg intravenously) was administrated immediately before reperfusion phase. At the end of the reperfusion period, rats were killed. Then, renal tissue samples were taken for biochemical analysis and histopathological evaluation, and blood samples were obtained to determinate serum urea, aspartate aminotransferase (AST), and tumor necrosis factor-alpha (TNF-alpha) levels. Ischemia-reperfusion injury caused significant increases in myeloperoxidase activity and malondialdehyde and 3-nitrotyrosine levels in renal tissue and elevated serum urea, AST, and TNF-alpha levels. In addition, severe deterioration of renal morphology was seen in the I/R group. Trapidil treatment significantly reduced in biochemical parameters, as well as serum urea, AST, and TNF-alpha levels. Furthermore, renal tissue injury was markedly attenuated with trapidil treatment. These data suggest that reactive oxygen species and reactive nitrogen species play a causal role in I/R-induced renal tissue, and trapidil has a renoprotective effect against oxidative and nitrosative kidney damage.

Animals↗
PubMed2005

Familial cystic nephroma in two siblings with pleuropulmonary blastoma.

Cystic nephroma (CN) and pleuropulmonary blastoma (PPB) are rare tumors. In the cases presented here, a 13-month-old boy underwent right radical nephrectomy for CN. From the family history we learned that four years ago the patient's older sister underwent left radical nephrectomy for CN at a different center when she was 4 years old. A lung tumor was detected in the sister one year after nephrectomy. Biopsy from the lung tumor revealed PPB, and the sister died within one year after biopsy. To the knowledge of the authors, these cases represent the second reported familial occurrence of CN and the fourth of CN and PPB.

Child, Preschool↗
PubMed2004

Evaluation of the toxic effects of cypermethrin inhalation on the frog heart.

Cypermethrin is widely used as an insecticide on animals and in agriculture, the home, and the garden. The effect of inhaled cypermethrin on the cardiac mechanics, electrophysiology, and ultrastructure in frogs was investigated in this study. Four groups received 100 microL of cypermethrin via inhalation for different exposure times, and one group was used as a control. Electrical and mechanical activities of the heart were recorded, and heart samples were examined at light and transmission electron microscopic levels for all groups. The atrial and ventricular contractile forces on the mechanogram, the amplitude of the P wave and the QRS complex on electrocardiogram, and the heart rate were significantly decreased in cypermethrin-inhalated frogs. The total duration of contraction was prolonged in the study groups. Ultrastructurally, dilatation in smooth endoplasmic reticulum cisterns, a decrease in the number of mitochondria, disorganization in the myofibrils of myocytes, and necrotic changes in endothelial cells were observed. These results suggest that cypermethrin has cardiotoxic effects that increase with exposure time.

Animals↗
PubMed2003

The effect of L-carnitine on the prevention of experimentally induced myringosclerosis in rats.

The objective of this study was to investigate the possible effect of L-carnitine on the prevention of experimentally induced myringosclerosis. Twenty Sprague-Dawley rats were bilaterally myringotomized. The rats were divided into two groups randomly: group 1 which were intraperitoneally administered saline and group 2 which were intraperitoneally administered L-carnitine. Blood samples were collected for biochemical evaluation and the tympanic membranes were harvested after 28 days. Histopathological and immunohistochemical evaluation were done under light microscopy. The mean malondialdehyde levels were 3.9+/-0.9 in group 2, and 7.9+/-1.1 in group 1 (P<0.001), nitric oxide levels were 25.6+/-6.4 in group 2 and 30.8+/-8.2 in group 1 (P=0.14) and acetylcholinesterase was 1035+/-60 in group 2 and 678+/-35 in group 1 (P=0.001). Myringosclerosis was more frequent and severe in group 1 than group 2 (P<0.007). Immunoreactivity was seen in 16 of 20 tympanic membranes in group 2 and six of 20 tympanic membranes in group 1 (P=0.005). We conclude that L-carnitine diminishes the occurrence of myringosclerosis in rats after myringotomy possibly by antioxidant activity and decreasing the formation of reactive oxygen species.

Animals↗
PubMed2003

[The development of the wrist joint in the fetal period].

OBJECTIVES: This study was designed to investigate the development and anatomical features of the wrist joint, particularly the scapholunate ligament and triangular disc in the fetal period and to identify possible congenital variations. METHODS: The study included 16 wrist joints of eight fetuses aborted at ages 8 to 14 weeks. The samples had no macroscopically discernible anomalies. Tissue specimens were fixed in 10% formalin solution, embedded in paraffin, and mounted on a microtome to obtain 5-micron sections in the coronal plane. Following staining with hematoxylin and eosin, conventional light microscopic examinations were performed. RESULTS: Organization of the carpal ligaments in the wrist joint began on the radial side in the 9th week. In the 10th week, the scapholunate ligament was formed; a membranous structure was observed, which lied from the interfacet prominence of the radius to the scapholunate ligament and divided the wrist joint into two cavities. The triangular disc formation began to appear at this stage. During the 11th and 12th weeks, the membranous structure underwent regression from the dorsal to the volar aspects, and at the end of the 14th week, the wrist joint became a single cavity. Also noted was the development of fibrous appearance of the scapholunate ligament and the triangular disc into fibrocartilage. Vascular areas were identified on the radial rather than the ulnar side of the scapholunate ligament, but vice versa for the triangular disc. Bicompartmental structure seemed to persist in the wrist joint of a 14-week-old fetus. CONCLUSION: In this study, we demonstrated that the scapholunate ligament and the triangular disc were not homogeneous in the fetal period in terms of vascularity and cellularity. We speculate that a plica-like membranous structure may persist in the wrist joint as a remnant of the fetal life. An accurate knowledge of the anatomy is necessary for the treatment planning and arthroscopic interpretation of the wrist joint.

Carpal Bones↗
PubMed2002

The role of poly(ADP-ribose) synthetase inhibition in preventing endotoxemia-induced intestinal epithelial apoptosis.

In this lipopolysaccharide (LPS)-induced endotoxemia model, the effects of 3-aminobenzamide (3-AB), a poly(ADP-ribose) synthetase (PARS) inhibitor, on ileal apoptosis were evaluated by light microscopy and M30 cell death staining. Moreover, the relationship between Bcl-2, iNOS expression, and serum nitrate (NO(3)(-)) levels were investigated. Thirty-two male Wistar rats, weighing 180-220g were randomly divided into four groups. The group I (control; n=8) received saline and group II (sepsis; n=8) received 10 mg kg(-1) LPS intraperitoneally. 3-AB was given to the group IV (S+3-AB; n=8) 20 min before giving LPS and to the group III (C+3-AB; n=8) 20 min before giving saline. Six hours later, blood and ileum samples were taken. Endotoxemic group exhibited significant apoptosis in intestinal epithelial cells and the immunohistochemical examination with M30 was demonstrated that the 3-AB reduced the LPS-induced intestinal apoptosis. Serum NO(3)(-) level was increased in endotoxemic group, whereas the elevation of NO(3)(-) level was prevented in LPS+3-AB group (P<0.05). The increased iNOS expression observed in the LPS group was also prevented by 3-AB. Compared with the endotoxemic group, ileal epithelial columnar cells from LPS+3-AB group had a dense Bcl-2 staining which was almost identical with control. In conclusion, 3-AB decreases LPS-induced apoptosis in ileum by preventing LPS-induced depletion of Bcl-2 and blocking iNOS gene. Modification of Bcl-2 expression by PARS inhibitors should further be investigated as a new therapeutic alternatives in septic states.

Animals↗
PubMed2002

Dexamethasone down-regulates endothelial expression of intercellular adhesion molecule and impairs the healing of bowel anastomoses.

OBJECTIVE: To find out the role of endothelial expression of intercellular adhesion molecule-1 (ICAM-1) in the healing of intestinal anastomoses in rats, and to establish the effects of peroperative treatment with corticosteroids. DESIGN: Experimental animal study. SETTING: University hospital, Turkey. MATERIAL: 78 Male Wistar rats. INTERVENTIONS: Rats were divided into four groups: Group I, colonic anastomosis only (=18); Group II, colonic anastomosis plus caecal ligation and puncture (=18); Group III, colonic anastomosis plus dexamethasone (=18); and Group IV, colonic anastomosis, plus caecal ligation and puncture, plus dexamethasone (=18). Six animals served as the sham group. The animals underwent bowel transsection and primary anastomosis Infection was produced by caecal ligation and puncture Preoperatively, dexamethasone was given intramuscularly in a dose of 2 mg/kg/day. MAIN OUTCOME MEASURES: After 1, 3 and 5 days, anastomotic healing and endothelial expression of ICAM-1 were measured microscopically. RESULTS: Anastomotic healing was significantly impaired in dexamethasone-treated animals, and endothelial expression of ICAM-1 was reduced. Endothelial expression of ICAM-1 was no higher in the infected group than in controls. Maximum expression of ICAM-1 on endothelial cells was seen on the first day in each group, and declined on the following days, although the sebsequent reduction in expression was not significant. CONCLUSION: Dexamethasone down-regulated expression of ICAM-1, which is important in migration of leucocytes from the circulation to the wound site, and significantly impaired the healing of intestinal anastomoses in rats.

Anastomosis, Surgical↗
PubMedDate not supplied

Effects of triazolopyrimidine on lipid peroxidation and nitric oxide levels in the corticosteroid-impaired healing of rat tracheal anastomoses.

Corticosteroids are used to reduce the oedema and prevent scar tissue formation of the upper airways by their ability to inhibit influx of inflammatory cells, limit capillary permeability and block collagen synthesis in the early stages of wound healing. Triazolopyrimidine (Trapidil) is an antiplatelet agent that acts in part as a phosphodiesterase inhibitor and as a competitive inhibitor of the platelet-derived growth factor (PDGF) receptor. Trapidil, with its vasodilator and NO releasing effect may have some potential to diminish the tissue injury. This study was carried out to evaluate the effects of trapidil (triazolopyrimidine) on lipid peroxidation and nitric oxide in the corticosteroid-impaired healing of tracheal anastomoses. Thirty-four adult Wistar rats were divided into five groups. The animals underwent tracheal transection and primary anastomoses. The groups were assigned as follows: group I, control, (GI, n = 6); group II, sham, (GII, n = 6); group III, dexamethasone, 0.1 mg kg(-1) twice daily intramuscularly, (GIII, n = 8); group IV, trapidil, 6 mg kg(-1) twice daily intraperitoneally (GIV, n = 7); group V, dexamethasone, 0.1 mg kg(-1) plus trapidil, 6 mg kg(-1) twice daily (GV, n = 7), for 1 week. After 1 week, anastomotic healing was assessed by measurement of bursting pressure, evaluation of histopathology, measurement of MDA and nitrite/nitrate levels. In GIII, GIV and GV bursting pressures resulted in significantly reduced anastomotic strength compared to the controls (p < 0.001 for all groups). The difference between bursting pressures of GIII and GIV was not found to be statistically significant (p = 0.966). In regard to fibroblast proliferation and collagen content, a significant difference was found between GIII and GI (p < 0.01), A significant difference was also found when GIV and GV were compared to GIII (p < 0.01). MDA and nitrite/nitrate levels were found to be higher in GIII when compared to all other groups. MDA levels of GIV and GV rats were found to be lower than GIII (p < 0.001, for both groups). The nitrite/nitrate levels of GIV and GV rats were found to be lower than GIII (p < 0.05), and higher than GI (p < 0.001). Trapidil may be useful for its preventive effects on lipid peroxidation and possible increases in NO in cases with corticosteroid-impaired healing of trachea anastomoses.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Bcl-2, iNOS, p53 and PCNA expression in normal, disordered proliferative, hyperplastic and malignant endometrium.

We attempted to determine Bcl-2, inducible nitric oxide synthase (iNOS), p53 and proliferating cell nuclear antigen (PCNA) expression, and the relationships between them, in endometrioid adenocarcinomas and precursor lesions. Expression of Bcl-2, iNOS, p53 and PCNA were investigated immunohistochemically in 91 samples from benign (proliferative (pEM), secretory (sEM), disordered proliferative (dEM), inactive/atrophic (aEM), hyperplastic endometrium) and malignant endometrial tissue. Staining scores for Bcl-2 in the dEM, endometrial hyperplasia (EMH) and endometrioid cancer (ECA) groups were higher than in the pEM group (P = 0.004; P = 0.036 and P = 0.020, respectively). A significant difference in proliferating cell nuclear antigen staining was found between simple and complex EMH samples (P = 0.000). An inverse relationship was found between iNOS and p53 in the hyperplasia group (r = -0.533, P = 0.019). While a significant difference was found in p53 staining in ECA between the pEM, dEM and EMH groups, no such difference was found in iNOS staining. In addition, there was no direct relationship between iNOS and p53 in the ECA group. It was concluded that the interaction between iNOS, p53 and Bcl-2 in proliferative processes in the development of type 1 endometrioid adenocarcinomas is different from that in tumors originating in other organs.

Adenocarcinoma↗