Browsing by Subject "Hormones"
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Item Somatostatin infusion and hemodynamic changes in patients with non-variceal upper gastrointestinal bleeding: A pilot study(2003) Saruç M.; Can M.; Küçükmetin N.; Tuzcuoglu I.; Tarhan S.; Göktan C.; Yüceyar H.Background: Intravenous somatostatin decreases acid secretion, splanchnic blood flow, and portal pressure, but the evidence for its efficacy in the treatment of non-variceal upper gastrointestinal bleeding has been mixed. We aimed to evaluate the vasoactive effect and possible mechanisms of somatostatin infusion in the cessation of non-variceal upper gastrointestinal bleeding. Material/Methods: Patients with non-variceal upper gastrointestinal bleeding without portal hypertension were enrolled in the study. They were given somatostatin infusion in a dose of 250 μgr/hour for 72 hours. Superior mesenteric arterial average flow velocity (SMA-V), SMA pulsatility index (SMA-PI), portal venous volume flow (PV-F), and renal artery resistance index (RA-RI) were measured two times for each patient by Doppler ultrasound; oncee on the first day of infusion therapy and again 6 hours or more after stopping the infusion. Results: 21 patients (12 male, mean age 44.1±9.9) with bleeding peptic ulcer were enrolled. During somatostatin infusion, PV-F was 33.7±19.7 cm3/sec. After stopping infusion, it increased to 56.3±16.0 cm3/sec (p=0.001). SMA-V was 39.7±13.1 cm/ sec and 64.4±15.1 cm/sec during somatostatin infusion and after cessation of somatostatin respectively (p=0.01). SMA-PI was 2.0±0.8 during somatostatin infusion but 2.8±0.8 without somatostatin infusion (p=0.02). However, RA-RI showed no difference between states with or without somatostatin infusion (p>0.05). Conclusions: Somatostatin infusion causes a decrease in arterial blood flow to the stomach and duodenum in patients with non-variceal upper gastrointestinal bleeding without portal hypertension. Somatostatin therapy also decreases portal blood flow while not altering renal blood.Item Immunohistochemical detection of transforming growth factor-α, epidermal growth factor, and vascular endothelial growth factor expression in hyperstimulated rat ovary(2005) Ozcakir H.T.; Giray S.G.; Ozbilgin M.K.; Uyar Y.; Lacin S.; Caglar H.Objective. The aim of the present study is to figure out the immunohistochemical expression of transforming growth factor-α (TGF-α), epidermal growth factor (EGF), and vascular endothelial growth factor (VEGF) in hyperstimulated rat ovaries. Methods. Twenty Wistar-Albino adult female rats (250-300 g) were taken into the study. The animals were randomly divided into two groups, each containing 10 rats: (i) stimulation group and (ii) control group. In the stimulation group, a stimulation regimen was administered to induce follicular maturity and ovarian hyperstimulation syndrome (OHSS) at the end using a 30-IU follicle-stimulating hormone that was administered subcutaneously for 4 consecutive days, followed by a 30-IU human chorionic gonadotropin on day 5 to induce ovulation. The rats, in the control group, received 0.2ml of 0.9% NaCl for 5 consecutive days to mimic the conditions of the study animals. At the end of the treatment period, all rats underwent ovariectomy and the sections of ovaries were stained for the TGF-α, EGF, and VEGF. Results. The expression of TGF-α, EGF, and VEGF in the endothelium, the stroma, the granulosa cells, and the corpus luteum was found to be significantly higher in the stimulated group, compared to that in the control group (p < 0.05). Conclusion. TGF-α, EGF, and VEGF are found to have increased in the hyperstimulated ovaries and this finding seems to be involved in the OHSS pathogenesis. © Acta Obstet Gynecol Scand 2005.Item The effect of Misoprostol, a prostaglandin E1 analog, on apoptosis in ischemia-reperfusion-induced intestinal injury(Elsevier GmbH, 2007) Topcu I.; Vatansever S.; Var A.; Cavus Z.; Cilaker S.; Sakarya M.The aim of this study was to investigate whether Misoprostol, a synthetic prostaglandin (PG) E1 analog, has any effect on the prevention of apoptosis in ischemia-reperfusion (I/R)-induced intestinal injury. Thirty adult male Wistar albino rats were divided into three groups: group I=sham operated+saline; group II=I/R+saline; and group III=I/R+Misoprostol. Misoprostol (50 μg/kg/d) was administered as an intragastric meal for 3 days. The terminal ileum was collected for histological and biochemical investigations. Apoptotic cells were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelled (TUNEL) reaction. Immunohistochemical analysis was performed to determine the distribution of inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS). Samples were also analyzed for malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). The number of TUNEL-positive cells was higher in group II when compared to the other two groups (p<0.05). In group III this value was higher when compared to group I, but lower than group II (p<0.05). iNOS immunoreactivity was not detected in ileum sections of group I animals, but moderate immunoreactivity was seen in group II and mild immunoreactivity in group III. The immunoreactivity of eNOS was moderate in ileum sections of all three groups. In ileum tissue, MDA was found to be higher in group II compared to group I (p<0.05), but there was no difference in group III. SOD was not different between groups I and III, but was significantly higher in group II (p<0.05). In our experimental model of I/R-induced intestinal injury, apoptosis is induced in enterocytes, whereas Misoprostol decreases enterocyte apoptosis in this experimental model. Our results indicate that Misoprostol may play a key role in the pathophysiologic events leading to failure of the intrinsic gut barrier defense mechanisms of intestinal epithelium. © 2007 Elsevier GmbH. All rights reserved.Item Profiling of angiogenic cytokines produced by hormone- And drug-refractory prostate cancer cell lines, PC-3 and DU-145 before and after treatment with gossypol(2008) Karaca B.; Kucukzeybek Y.; Gorumlu G.; Erten C.; Gul M.K.; Cengiz E.; Atmaca H.; Uzunoglu S.; Sanli U.A.; Karabulut B.; Uslu R.In this study, we aimed to investigate the angiogenic cytokine profiles of hormone- and drug- refractory prostate carcinoma cell lines, PC-3 and DU-145. We also studied the effect of gossypol, a natural polyphenolic cotton-seed extract, on the angiogenic cytokine profile of these cell lines. XTT cell proliferation assay was used for the assessment of cytotoxicity. For apoptosis, both histone-DNA fragmentation by ELISA assay and caspase 3/7 activity measurement were used. Angiogenic cytokine profiles of supernatants from both cell lines, before and after treatment with gossypol, were investigated using the human angiogenesis antibody array I®. It was shown that the two different hormone- and drug-resistant prostate cancer cell lines, PC-3 and DU-145, constitutively express some important angiogenic cytokines, which are known to regulate tumorigenic- ity and angiogenesis in hormone-refractory prostate cancer. However, PC-3 and DU-145 cells have distinct angiogenic cytokine profiles. In addition, these two cells lines respond differently to gossypol treatment in terms of cytotoxicity and angiogenic cytokine secretion. After treatment with 10 μM of gossypol, there was a 1.5-fold decrease in angiogenin and IL-8 levels and a 1.7- and 1.8-fold decrease in ENA-78 and GRO-α levels respectively, in DU-145 cells. For PC-3 cells, there were 1.6- and 1.8-fold decreases in IL-8 and VEGF levels, respectively. We conclude that PC-3 and DU-145 cells secrete significant amounts of different angiogenic cytokines that may explain their aggressive nature and metastatic potential. Gossypol treatment affects angiogenic cyto- kine secretion from these two cell lines in a different manner. By expanding our knowledge of the heterogeneous biological behavior of these two cell lines, novel treatment approaches can be developed for the treatment of prostate cancer.Item Regulation of apoptosis-related molecules by synergistic combination of all-trans retinoic acid and zoledronic acid in hormone-refractory prostate cancer cell lines(2011) Karabulut B.; Karaca B.; Atmaca H.; Kisim A.; Uzunoglu S.; Sezgin C.; Uslu R.We report that all-trans retinoic acid (ATRA) in combination with zoledronic acid has strong synergistic cytotoxic and apoptotic effects against human hormone- and drug-refractory prostate cancer cells, PC-3 and DU-145, in a time- and dose-dependent manner. We further investigated the effect of the combination treatment on the apoptotic process by both oligoarray and protein array analysis in DU-145 cells, in which the drug combination shows much more strong synergistic effects, as compared to PC-3 cells. Moreover, we have also performed real time-PCR array analysis to validate oligoarray results. We demonstrated that the combination of ATRA and zoledronic acid is a strong inducer of apoptotic related cell death in human androgen-and drug refractory prostate cancer cells DU-145, at either transcriptional or translational levels. While expression of proapoptotic genes such as tumor necrosis factor receptor superfamily (TNFRSF), Bad, Bax, Fas, FADD are induced with the exposure of the combination, expression of antiapoptotic genes or proteins such as members of inhibitor apoptosis family (IAPs), MCL-1, LTBR, p53 and bcl-2 are reduced. Because this novel combination treatment has fewer side effects than is generally the case with conventional cytotoxic agents, this regimen may be a good option for treatment of elderly prostate cancer patients. © 2010 Springer Science+Business Media B.V.Item Study on bi-directional pedestrian movement using ant algorithms(Institute of Physics Publishing, 2015) Gokce S.; Kayacan O.A cellular automata model is proposed to simulate bi-directional pedestrian flow. Pedestrian movement is investigated by using ant algorithms. Ants communicate with each other by dropping a chemical, called a pheromone, on the substrate while crawling forward. Similarly, it is considered that oppositely moving pedestrians drop 'visual pheromones' on their way and the visual pheromones might cause attractive or repulsive interactions. This pheromenon is introduced into modelling the pedestrians' walking preference. In this way, the decision-making process of pedestrians will be based on 'the instinct of following'. At some densities, the relationships of velocity-density and flux-density are analyzed for different evaporation rates of visual pheromones. Lane formation and phase transition are observed for certain evaporation rates of visual pheromones. © 2016 Chinese Physical Society and IOP Publishing Ltd.