Özgül Tap

The effect of edaravone on ischemia-reperfusion injury in rat ovary.

OBJECTIVE The aim of this study was to investigate the effect of edaravone on experimentally induced ovarian torsion/detorsion ischemia/reperfusion (I/R) injury. STUDY DESIGN Forty-six female adult Wistar-Albino rats were utilized to create five groups: In group 1, only 5 mg/kg edaravone was given and ovary torsion was not performed. In group 2, torsion was not performed and no drug was given. In group 3, vehicle was given and torsion/detorsion was performed. In group 4, 1 mg/kg edaravone was given and torsion/detorsion was performed. In group 5, edaravone; 5 mg/kg drug was administered and torsion/detorsion was performed. Right ovarian torsion was simulated for a 3-h period of ischemia and a 1-h reperfusion period. Right ovaries were then surgically extirpated in all groups. In ovarian tissue samples malondialdehyde (MDA) levels and activity of superoxide dismutase were studied. Microscopic ovarian tissue damage was scored by histologic and electron microscopic findings. RESULTS The MDA level in the group 5 was significantly lower than group 3 (p<0.001). Superoxide dismutase activity in the group 5 was significantly higher than group 3 (p<0.001). Histopathological ovarian tissue damage in the group 5 were significantly lower than group 3 (p<0.001). CONCLUSION These results indicate that edaravone could be an effective agent in the short-term treatment and prevention of ovarian ischemia and reperfusion damage.

Adenoids and otitis media with effusion : A morphological study

PURPOSE Adenoidectomy, especially for the treatment of suppurative otitis media, has been used for a very long time. In this study, the role of adenoids in the origin of otitis media with effusion was investigated by using light microscopy, immunocytochemistry, enzyme chemistry, and electron microscopy. MATERIALS AND METHODS A group of 28 children with otitis media with effusion (OME) was identified. Ages ranged from 3 to 12 years. A control group of 10 age-matched children without any middle ear and upper respiratory tract infection served as the basis for comparison. Specimens obtained at surgeries from both groups were divided into groups for light microscopy, immunocytochemistry, enzyme cytochemistry, and electron microscopy and then all were examined blindly. Also, quantitative analysis of antigen-presenting cells was performed blindly on 10 patients and 10 controls. RESULTS There was an increase in the number of lymphocytes, mast cells, plasma cells, macrophages, dendritic cells, and M cells in the adenoids of patients with OME when compared with the normal cases. Stratified squamous epithelial areas, collagenous fibers, and fibrocytes were also increased in the patient group. Antigen-presenting functions of epithelial cells are shown by major histocompatibility complex (MHC) class II positivity of some ciliated-columnar epithelial cells in the patient group. CONCLUSION Adenoid tissues of patients with OME in this study seem to be infectious foci, aggravating immune reactions, which might attack the middle ear through an ascending route.

Experimental evaluation of peritoneum and pericardium as dural substitutes

Although many substances have been tested in the search for an ideal dural substitute, an entirely satisfactory material has still not been found. The authors report an experimental study involving the closure of dural defects in rabbits with biomaterials developed from pig peritoneum and pericardium. Macroscopic and histologic examination, performed over a period between 15 and 45 days after implantation showed slight or no adhesion between the graft material and the cortex. No infection, CSF leakage, fistula or toxicity was noticed. The results demonstrated that these biomaterials could be used as satisfactory dural substitutes.

Effects of Methotrexate on the Tubal Morphology of Rabbits: Evaluation by Electron Microscopy

Background/Aims: To evaluate by electron microscopy the effects of methotrexate on the tubal morphology of rabbits. Methods: Biopsies were taken from the isthmic portion of both tubes of 4 rabbits in the control group. 1 mg/kg methotrexate was injected in the left tubes and as a control, a 14-gauge fine needle was used to puncture the right tubes of 10 rabbits in the study group. One month later, tubal biopsies were taken from both tubes of every rabbit in the study group. To mimic pregnancy, 100 IU hCG was injected intramuscularly to every rabbit 24 h before every surgery. On examination by electron microscopy, the effects of methotrexate and of the damage with the fine needle on the tubes were compared to the control group. Results: Young epithelial cells of the methotrexate-injected fallopian tubes kept their normal structure, but others contained important ultrastructural changes. These were: nuclear pyknosis, cytoplasmic vacuolization, dilatation of endoplasmic reticulum cisternae, increased cytoplasmic density and compound cilia. Conclusion: Degenerative changes on epithelial cells caused by the temporary blockage of mitotic activity associated with local methotrexate injection are reversible through the formation of new epithelial cells.

Investigating the clinical significance of mesh peritonization in abdominal vault suspension surgery using a comparative rabbit model

OBJECTIVE To investigate the clinical significance of mesh peritonization in an experimental rabbit model. STUDY DESIGN Twenty rabbits were randomly assigned to two groups. A sacrouteropexy operation was performed in both groups using a polypropylene mesh. In the first group, the pelvic peritoneum was not closed over the mesh, and in the second group, the mesh was buried throughout the pelvic retroperitoneal tunnel. One month after mesh implantation, the abdomen was opened and the previous surgical site was explored. The primary outcome was intraabdominal adhesion formation; the secondary outcome was the histologic degree of tissue remodeling. RESULTS There were no statistically significant differences between the two groups in terms of adhesion scores and collagen organization (P=0.692, P=0.097, respectively). There was a greater degree of inflammation in the second group as identified by significantly higher scores for eosinophils-neutrophils, macrophages-foreign body giant cells and mononuclear cells (P=0.002, P=0.001 and P=0.002, respectively). CONCLUSIONS Similar adhesion and collagen organization patterns were found in both groups, but indicators of the inflammatory process were significantly higher in the second group.

Ultrastructural changes in the contralateral lung tissue following unilateral lung ischemia: an experimental study in rabbits.

AbstractPurpose. To investigate the acute ultrastructural changes that may occur in the contralateral nonischemic lung tissue after unilateral ischemia of a lung in a rabbit model. Methods. The animals were divided into three main groups of eight; namely, a 2-h procedure group, a 4-h procedure group, and an 8-h procedure group. Each of these groups was further divided into two subgroups of four rabbits each; namely, a control group, given a sham operation without any ischemic insult, and an ischemia group, in which the main pulmonary arteries, the pulmonary veins, and the main bronchi of the left lungs were ligated after thoracotomy. Tissue samples were taken from the left and right lungs to examine the ultrastructural changes after 2, 4, and 8 h of ischemia. Each sample was given a semiquantitative histological injury score. Statistical analysis was done by the Mann-Whitney U-test. Results. Contralateral ultrastructural damage, evident by heterochromatin in the nuclei, mitochondrial degeneration, cisternal widening of the endoplasmic reticulum, increased lipid droplets, and lysosomes, was determined by electron microscopy after unilateral lung ischemia. The contralateral lung injury was significantly correlated with the duration of ischemia. Conclusions. Unilateral lung ischemia affected the bilateral lungs in a rabbit model. Therefore, in operations such as single-lung transplantation, pulmonectomy, or lobectomy, if the procedure is unnecessarily prolonged, the contralateral lung may be damaged, which could seriously affect the prognosis of the patient.

Investigation of the uterine structural changes in the experimental model with polycystic ovary syndrome and effects of vitamin D treatment: An ultrastructural and immunohistochemical study

In this study, we aimed to investigate the structural changes seen in the endometrium in experimental PCOS rat model and the effects of vitamin D treatment on these changes at immunohistochemical and electron microscopic levels. 24 prepubertal female rats were divided into three groups. Two groups were injected with dehydroepiandrosterone and one of them was treated with 1,25(OH)2 D3 at the same time. The control group was injected with sesame oil. At the end of the 28th day, the blood samples were collected. Uterus tissues were prepared for light and electron microscopic examinations. Epithelial, stromal and endometrial thickness measurements were investigated. Immunohistochemical staining was applied against caspase-3 and Ki-67. Serum AMH and estradiol levels were higher in PCOS group compared to the control group. Serum progesterone levels were similar in all groups. Endometrial, epithelial and stromal thickness measurements were increased in PCOS group compared to the control group, and decreased in the vitamin D treatment group compared to the PCOS group. Light and electron microscopic results of PCOS group showed an increase in apoptosis and proliferation. In the PCOS group, immunohistochemical staining of caspase-3 and Ki-67 were found to be higher than in the control group, but stainings were decreased with vitamin D treatment compared to PCOS group. Structural changes observed in endometrium may be related to implantation problems seen in patients with PCOS. Our studies suggest that vitamin D therapy may be beneficial in these patients.

Ultrastructural and hormonal changes in the contralateral adrenal gland in unilateral adrenal gland ischemia: An experimental study in rats

While it is well known that unilateral tissue ischemia may result in contralateral damage in some paired organs, there is no universally accepted mechanism to explain why these contralateral changes occur. The aim of the present study was to investigate the ultrastructural and hormonal changes that occur in the contralateral nonischemic adrenal gland after unilateral ischemia of an adrenal gland in a rat model. The animals were divided into four groups of four rats each; namely, a control group which received a sham operation without any ischemic insult, a 2-h ischemic group, a 4-h ischemic group, and an 8-h ischemic group. The left adrenal blood vessels were ligated in all ischemia groups and blood samples were taken for hormonal study 2, 4, and 8h later, after which bilateral adrenalectomy was performed to determine the ultrastructural changes. The plasma concentrations of aldosterone and cortisol were determined by radioimmunoassays. There was an increase in both aldosterone and cortisol levels related to the duration of the ischemia, but the differences among the groups were not statistically significant. Contralateral ultrastructural damage such as heterochromatin in nuclei, mitochondrial degeneration, endoplasmic reticulum cisternal widening, increased lipid droplets, and lysosomes, were demonstrated electron-microscopically after unilateral adrenal ischemia.