Süheyla Gonca

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.

Chronic Ethanol-Induced Glial Fibrillary Acidic Protein (GFAP) Immunoreactivity: An Immunocytochemical Observation in Various Regions of Adult Rat Brain

In the present study, the effects of chronic ethanol (ETOH) treatment on the glial fibrillary acidic protein (GFAP) immunoreactivity was investigated in adult rat brains. ETOH were administered as increasing concentrations of 2.4%–7.2% (v/v) gradually for 21 days. Immunocytochemistry revealed that chronic-ETOH treatment increased synthesis of GFAP. The increase in the diameter and the number of GFAP (+) cells were statistically significant compared with the control group (p <. 05). An increase of GFAP immunoreactivity was evident in various white matter and gray matter structures. We concluded that functional astrocytic cells responded to chronic ETOH exposure by increasing the synthesis of GFAP.

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.

Effects of chronic ethanol treatment on glial fibrillary acidic protein expression in adult rat optic nerve: an immunocytochemical study

Glial fibrillary acidic protein (GFAP) is used as a marker of astrocyte response to various central nervous system injuries. In the present study, the effects of chronic ethanol administration on GFAP immunoreactivity were evaluated in astrocytes of the adult optic nerve head. The results demonstrated that ethanol exposure significantly and dramatically increases GFAP immunoreactivity and the number of immunoreactive astrocytes (p<0.001). In addition, GFAP immunoreactive cells in the optic nerve showed extensive hypertrophy (p<0.001).

Comparison of conventional and no-touch techniques in harvesting saphenous vein for coronary artery bypass grafting in view of endothelial damage.

BACKGROUND Optimization of saphenous vein patency for myocardial revascularization. OBJECTIVE The goal of this study was to present the no-touch technique of saphenous vein preparation. This technique consists of harvesting the vein with a pedicle of surrounding tissue, which protects the vein from distension pressure. METHODS We performed a prospective, randomized study that compared 2 techniques for harvesting saphenous vein-conventional and no-touchin 40 patients undergoing coronary artery bypass grafting. We carried out a morphologic study of the endothelium with the aid of light and transmission electron microscopy and an immunohistochemical assessment to identify adenosine, inducible nitric oxide synthase (iNOS), and vascular endothelial growth factor (VEGF) in the vein wall. RESULTS The integrity of endothelial cell and all vascular layers was maintained better with the no-touch technique than with the conventional procedure. The immunohistochemical assessment revealed that adenosine receptor, iNOS, and VEGF immunoexpression levels were normal or lower in the no-touch group than in the conventional-harvest group, as shown by the staining densities in all layers of the vein wall. CONCLUSION Endothelial integrity and adenosine, iNOS, and VEGF immunoreactivities were better preserved when the no-touch technique was used for vein graft harvesting. The mechanical protection provided by the cushion of surrounding tissue in the no-touch group and the vasorelaxation and thromboresistant activities of nitric oxide may be responsible for the reduction in vasospasms and the improved patency rate.

Effects of Thoracic Epidural Anesthesia on Flow and Endothelium of Internal Thoracic Artery in Coronary Artery Bypass Graft Surgery

OBJECTIVES The internal thoracic artery (ITA) is the preferred conduit for coronary artery bypass graft (CABG) surgery. The authors investigated whether thoracic epidural anesthesia (TEA) as an adjunct to general anesthesia (GA) can increase the blood flow of the ITA. DESIGN A prospective randomized study. SETTING A university hospital. PARTICIPANTS Patients with ischemic heart disease. INTERVENTIONS Thirty patients scheduled for elective CABG surgery were randomized to receive either GA (n = 15) or GA + TEA (n = 15) after receiving institutional review board approval. Demographics showed similarity between the groups. The epidural catheter was inserted in the thoracic region between T1 and T5 levels. In the GA + TEA group, the patients received a 20-mg bolus of 0.25% bupivacaine through epidural catheters 1 hour before surgery, and this was followed by the infusion (20 mg/h) of 0.25% bupivacaine. In all patients, ITA free blood flow was measured before cardiopulmonary bypass and without the administration of any vasodilatory agent. A short segment of ITA was excised for histologic examination; immunocytochemistry analysis was performed using antirabbit polyclonal VEGF antibody, rabbit polyclonal inducible nitric oxide synthase (i-NOS) antibody, and adenosine anti-A2B receptor antibody. The immunoreactivity rates then were evaluated. MAIN RESULTS The mean ITA free flow in the GA + TEA group was significantly higher than in the GA group (56.0 ± 9.0 mL/min v 39.6 ± 14 mL/min, p = 0.001). Immunostaining intensity in the sections after incubation with each primary antibody increased in the GA + TEA group compared with the GA group. CONCLUSIONS The results of this study indicated that TEA increased ITA free blood flow significantly via increased VEGF, i-NOS, and adenosine-A2B receptor expressions. Therefore, the use of TEA as an adjunct to GA might be considered as an alternative to vasoactive agents for increasing ITA flow in CABG surgery.

LOCALIZATION OF PAN‐CADHERIN IMMUNOREACTIVITY IN ADULT RAT TISSUES

Cadherins, being responsible for selective cell recognition and normal tissue integrity in adults, regulate morphogenesis in a variety of organs during development. In this study, anti‐rat pan‐cadherin antibody, specific to all subgroups of the cadherin family, was used to map the distribution of the pan‐cadherin immunoreactivity in adult rat organs. Pan‐cadherin immunoreactivity positive tissues were: secretory cells of the adenohypophysis, autonomic nerve, corneal epithelium, oesophageal nerve plexus, stomach and pyloric glandular cells, epithelium of the ileum and its nerve plexus, alveolar cells of the lung, proximal convoluted tubules of the kidney, islet cells of Langerhans, and the acinar cells of the exocrine pancreas. For the first time, positive pan‐cadherin immunoreactivity was demonstrated in the epithelial cells of the corpus ciliaris and in the nerve plexus of corpus cavernosum of the penis. In conclusion, our results suggest that cells in many tissues and organs of the adult rat synthesize cadherins.

Effect of Electrocautery on Endothelial Integrity of the Internal Thoracic Artery: Ultrastructural Analysis with Transmission Electron Microscopy

The internal thoracic artery (ITA) is typically harvested from the chest wall by means of conventional electrocautery. We investigated the effects of electrocautery on endothelial-cell and vessel-wall morphology at the ultrastructural level during ITA harvesting. Internal thoracic artery specimens from 20 patients who underwent elective coronary artery bypass grafting were investigated in 2 groups. The ITA grafts were sharply dissected with use of a scalpel and clips in the control group (n=10) and were harvested by means of electrocautery in the study group (n=10). Each sample was evaluated for intimal, elastic-tissue, muscular-layer, and adventitial changes. Free flow was measured intraoperatively. Light microscopic examinations were performed after hematoxylin-eosin and Massons trichrome staining. Transmission electron microscopy was used to evaluate ultrastructural changes in the endothelial cells and vessel walls of each ITA. In the sharp-dissection group, the endothelial surfaces were lined with normal amounts of original endothelium, endothelial cells were distinctly attached to the basal lamina, cytoplasmic organelles were evident, and intercellular junctional complexes were intact. Conversely, in the electrocautery group, the morphologic integrity of endothelial cells was distorted, with some cell separations and splits, contracted cells, numerous large cytoplasmic vacuoles, and no visible cytoplasmic organelles. The subendothelial layer exhibited disintegration. Free ITA flow was higher in the sharp-dissection group (P=0.04). The integrity of endothelial cells can be better preserved when the ITA is mobilized by means of sharp dissection, rather than solely by electrocautery; we recommend a combined approach.