Êxpression of inducible nitric oxide synthase (iNOS) in the azoospermic human testis.

Azoospermia, which is the absence of spermatozoa in the ejaculate, is not a rare cause of male infertility. Inducible nitric oxide synthase (iNOS) is a calcium-independent NOS, which is present in the testis and involved in spermatogenesis, and apoptosis of Sertoli and germ cells. Twenty idiopathic infertile men presenting nonobstructive azoospermia were enrolled in this study, and testicular sperm extraction procedures were performed. Tissue extracts were dissected, and the fluid samples were investigated to determine the presence of spermatozoa. Histologic evaluation of the spermatozoa-present samples revealed that seminiferous tubules were normal and were lined by Sertoli cells and spermatogenic cells. However, in the spermatozoa-absent samples, the diameter of the seminiferous tubules was small, and Sertoli-cell-only syndrome was determined in most of the tubules. iNOS expression was very weak in Sertoli cells, germ cells, and in Leydig cells in the spermatozoa-present group. In the spermatozoa-absent group, the immunostaining was very intense in Sertoli and Leydig cells. Electron microscopy findings were supported the histologic results. In conclusion, complete germ cell loss and intense expression of iNOS in the Sertoli and Leydig cells in the spermatozoa-absent groups of azoospermic human testis suggest an essential role of iNOS in spermatogenesis.

The cardioprotective effects of thoracal epidural anestesia are induced by the expression of vascular endothelial growth factor and inducible nitric oxide synthase in cardiopulmonary bypass surgery.

AIM: The cardioprotective effects of thoracal epidural anesthesia (TEA) are induced by the expression of vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase (i-NOS) in cardiopulmonary bypass (CPB) surgery. When general anaesthesia (GA) is combined with TEA during coronary artery bypass graft, we investigated whether TEA together with GA play a role on VEGF and i-NOS expression in human heart tissue in cardiac ischemia. METHODS: Right atrial biopsy samples were taken before CPB, before aortic cross clamp (ACC) and at 15 min after ACC release (after ischemia and reperfusion). Human heart tissues were obtained from the TEA+GA and GA groups. Immunocytochemistry was performed using antibodies for VEGF and i-NOS. RESULTS: Both VEGF and i-NOS immunoreactivity was observed in cardiomyocytes and arteriol walls. Although VEGF and i-NOS immunoreactivity was apparent in both groups,, immunostaining intensity was greater in the TEA+GA group than the GA group. Between groups, at 4 h and at 24 h after the end of CPB, the cardiac index (CI) was significantly higher in the TEA+GA group than GA group (3.4+/-0.8 L/min/m(2) vs 2.5+/-0.8 L/min/m(2); P<0.001), (3.8+/-1.1 L/min/m(2) vs 3.1+/-1.1 L/min/m(2); P<0.008) respectively. Within groups, at 4 and 24 h after the end of CPB, the CI was significantly higher in the TEA+GA group than baseline values, (3.4+/-0.8 L/min/m(2) vs 2.4+/-0.7 L/min/m(2); P<0.001), (3.8 +/-1.1 L/min/m(2) vs 2.4+/-0.7 L/min/m(2); P<0.001) respectively, but no difference was found in the GA group (2.6+/-0.8 L/min/m(2) vs 2.5+/-0.8 L/min/m(2); P>0.05), (2.6+/-0.8 L/min/m(2) vs 3.1+/-1.1 L/min/m(2); P>0.05) respectively. After ACC release, 11/40 (27.5%) patients in the TEA+GA group showed ventricular fibrillation (VF), atrial fibrillation or heart block versus 25/40 (62.5%) of those in the GA group. VF after ACC release in the TEA+GA group (9/20 patients, 22.5%) was significantly lower than in the GA group (21/40 patients, 52.5%); (P<0.006). Sinus rhythm after ACC release in the TEA+GA group (29/40 patients, 72.5%) was significantly higher than in the GA group (15/40 patients, 37.5%); (P<0.002). CONCLUSIONS: The results of the present study indicate that TEA plus GA in coronary surgery preserve cardiac function via increased expression of VEGF and i-NOS, improved hemodynamic function and reduced arrhythmias after ACC release.

General anesthesia with thoracic epidural anesthesia in the cardiopulmonary bypass surgery reduces apoptosis by upregulating antiapoptotic protein Bcl-2.

AIM: The aim of the paper was to investigate whether thoracic epidural anesthesia (TEA) together with general anaesthesia (GA) play a role on apoptosis in humans before cardiopulmonary bypass (CPB), before aortic cross clamp (ACC) and at 15 min after ACC release (after ischemia and reperfusion). METHODS: Eighty patients scheduled for elective CABG were randomized to receive either GA group (n: 40) or TEA+GA group (n: 40). The right atrial biopsy samples were taken before CPB, before ACC and at 15 min after ACC release from all patients. Human heart tissues were obtained from patients of TEA+GA group and GA group. The number of Bcl-2 positive cardiomyocytes was counted in multiple tissue sections of biopsies of 80 patients using light microscopy (magnification x 40) with an ocular micrometer system (Olympus). RESULTS: In the TEA+GA group, the Bcl-2 positive cardiomyocytes were distinctly statistically increased compared to the GA group (P<0.001). In addition, the intensity of the immunostaining was also increased in the TEA+GA compared with the GA group. The number of immunoreactive cardiomyocytes is as follows: before CPB, TEA+GA group 396+/-61, GA group 92+/-41, before ACC, TEA+GA group 333+/-47, GA group 94+/-18, at 15 min after ACC release, TEA+GA group 346+/-68.8, GA group 85+/-9.5. There were statistically significant differences between groups, (P<0.001). Between groups, at 4 h and at 24 h after the end of CPB, in the TEA+GA group, the CI was significantly higher than GA group respectively; (3.4+/-0.8 L/min/m(2) vs 2.5+/-0.8 L/min/m(2); P<0.001), (3.8+/-1.1 L/min/m(2) vs 3.1+/-1.1 L/min/m(2); P<0.008). Within groups, at 4 and 24 h after the end of CPB, in the TEA+GA group, the CI was significantly higher than baseline values, respectively, (3.4+/-0.8 L/min/m(2) vs 2.4+/-0.7 L/min/m(2); P<0.001), (3.8+/-1.1 L/min/m(2) vs 2.4+/-0.7 L/min/m(2); P<0.001). Whereas no difference was found in the GA group respectively, (2.6+/-0.8 L/min/m(2) vs. 2.5+/-0.8 L/min/m(2); P>0.05), (2.6+/-0.8 L/min/m(2) vs. 3.1+/-1.1 L/min/m(2); P>0.05). The number of patients showing ventricular fibrillation (VF), atrial fibrillation or heart block after release of the ACC was 11 of 40 (27.5%) in the TEA+GA group versus 25 of 40 (62.5%) in the GA group. The number of patients showing VF after release of ACC was 9 out of 20 patients (22.5%) in the TEA+GA group which was significantly lower than in the GA group (21 of 40 patients 52.5%); (P<0.006). Sinus rhythm after release of ACC, in the TEA+GA group was observed in 29 of 40 patients (72.5%) and was significantly higher than in the GA group (15 of 40 patients 37.5%); (P<0.002). CONCLUSION: The result of the present study indicate that TEA plus GA in coronary surgery had preserved cardiac function during intraoperative and postoperative period by means of reduced apoptosis, improved hemodynamic function and reduced arrhythmias after release of the ACC.

Localization of neural cell adhesion molecule (N-CAM) immunoreactivity in adult rat tissues.

Neural cell adhesion molecule (N-CAM) mediates homophilic adhesion between cells and heterophilic adhesion between cells and extracellular matrix in a Ca2+-independent manner. N-CAM is widely expressed during development and plays a crucial role in cell division, migration, and differentiation, but its expression is restricted in adults. The distribution of N-CAM immunoreactivity in adult rat tissues was investigated in the present study. N-CAM immunoreactivity was present in the nervous system in the molecular layer of the cerebellum, ependymal cells surrounding the central canal, axons of the white matter, and in Lamina X of the gray matter of the spinal cord. N-CAM immunoreactivity also was found in autonomic nerves. In the digestive system, N-CAM immunoreactivity was found in the stratified squamous epithelium and nerve plexus of the esophagus, glandular cells of the stomach and pylorus, lamina propria, and epithelium of the villi of the duodenum, jejunum, and ileum. N-CAM immunoreactivity was demonstrated in the secretory cells of the adenohypophysis, islets of Langerhans, and acinar cells of the exocrine pancreas. Alveolar cells of the lung were also N-CAM immunoreactive. In the urinary system, N-CAM immunoreactivity was seen in the proximal convoluted tubules of the kidney. In the male reproductive system, N-CAM immunoreactivity was demonstrated in the nerve plexus around the urethral epithelium and in the nerve fibers around the smooth muscle cells of the corpus cavernosum penis. In the visual system, N-CAM immunoreactivity was seen in the epithelial cells of the corpus ciliaris. Cornea and lens epithelium also showed positive immunoreactivity. Our results suggest that cells in many tissues and organs of the adult rat synthesize N-CAM.

Expression of insulin-like growth factor in the placenta of intrauterine growth-retarded human fetuses.

Many cases of intrauterine growth retardation (IUGR) are the result of placental and fetal tissue insufficiency. Insulin-like growth factor-I (IGF-I) is known to play a role in placental and fetal growth. An immunocytochemical study was performed to localize IGF-I peptides in human placenta and umbilical cords of normal (n = 3) and IUGR (n = 3) fetuses. The peripartum fetal conditions were evaluated as well. Immunoreactive IGF-I was detected in the cytotrophoblast, syncytiotrophoblast, amnion, endothelial cells of fetal capillaries and in the decidua in both normal and IUGR placental tissue. A more robust immunostaining and increased numbers of positively stained cells were found in the decidua of IUGR placenta (p < 0.001). Intense immunostaining was also found in endothelial cells, smooth muscle cells and fibroblasts of the umbilical vein. IGF-I immunoreactivity was also present in stroma (Hofbauer cells and/or fibroblasts) of IUGR villi. Our results indicate that expression of IGF-I is high in specific sites in placenta and umbilical cords, which indicates a paracrine and/or endocrine function. The increased expression of IGF-I in placenta of IUGR fetuses indicates its involvement in restoring normal growth by means of a positive feed-back mechanism.

Protective effects of vitamin E and selenium on the renal morphology in rats fed high-cholesterol diets.

The histopathological effects of cholesterol and the protective effects of vitamin E and selenium (Se) on renal histology were examined in Sprague-Dawley rats. Light-microscopic evaluation of the renal cortex revealed: glomerular fibrosis, cellular and mesangial proliferation, capillary obliteration and cholesterol crystals in the tubular lumina of the cholesterol-fed group. These results suggest that oxidated LDL (O-LDL) is a cytotoxic factor which stimulates mesangial cell and matrix proliferation. Ultrastructurally, small and large lipid vacuolization in intracapillary lumina, adhesion of epithelial foot processes, mesangial foam cells and polymorphonuclear leukocytes were seen in the cholesterol-fed group. In the groups fed cholesterol + vitamin E, cholesterol + Se and cholesterol + vitamin E + Se, morphological improvements were observed. It appeared that an excess in O-LDL, reactive oxygen species and growth factors might play an important role in the pathogenesis of glomerulosclerosis. In addition, it was concluded that antioxidant therapy may prevent LDL oxidation and generation of free radicals.