Browsing by Author "Ates U."

Now showing 1 - 6 of 6
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    Repeated epidural injections of ketamine with preservative benzethonium chloride produce evidence for neurotoxicity in rabbits
    (2003) Yentur E.A.; Mirzai I.T.; Mirzai H.; Ates U.; Baka M.; Yurtseven M.
    Background and objectives: In this study, we investigated whether repeated doses of 1% ketamine with preservative benzethonium chloride, administered into the epidural space of the rabbit, caused direct neurotoxicity. Methods: Twelve rabbits were randomly assigned to two groups (ketamine and control). After the animals were anesthetized, lumbar epidural catheters were placed for repeated epidural drug delivery. The ketamine group received 1% ketamine with preservative benzethonium chloride (0.5 ml) and the control group received isotonic saline (0.5 ml) once a day for 14 consecutive days. The day after the last injection, the animals were reanaesthetized, the left and right ventricles were cannulated and perfused with 2% glutaraldehyde, 1% formaldehyde mixture, in 0.1 mol/l phosphate buffer. Then, laminectomy was performed. A five centimetre segment of the spinal cord was removed and examined by light and electron microscopy to observe possible histological changes. Microscopic examinations were performed by coding each animal by a neuro-histologist who was blinded as to the source of each specimen. Results: Ketamine-treated rabbits showed significant histological changes at light and electron microscopy findings compared with the control group (p < 0.05). Conclusions: These changes suggested a neurotoxic effect of ketamine with preservative benzethonium chloride following chronic epidural administration.
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    Chemotherapy influences inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) activity on 3D breast cancer cell line
    (Tech Science Press, 2006) Öktem G.; Bilir A.; Selvi N.; Yurtseven M.E.; Vatansever S.; Ates U.; Uysal A.; Omay S.B.
    Multicellular tumor spheroids (MTS) are three-dimensional structural forms of tumors grown in vitro in the laboratory. In this study, the aim was to determine the regulation of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) expressions on MTS in response to treatment with the commonly used anti-cancer drugs Doxorubicin and Docetaxel. The spheroids were generated using the "liquid overlay" technique. The distribution of both iNOS and eNOS was detected using indirect immunohistochemistry, while the expression of both iNOS and eNOS was measured using Western blots. Additionally, S-phase analysis using 5-bromo-2′- deoxyuridine (BrdU) was done on the MTS after treatment with doxorubicin, docetaxel, and a combination of the two. The Griess method was used to measure nitric oxide (NO) production in the cells. An increase in iNOS immunoreactivity and a decrease in eNOS immunoreactivity were observed after doxorubicin treatment, when compared with the other groups. Furthermore, upregulation of iNOS and downregulation of eNOS were detected in doxorubicin-treated cells using Western blotting. Insignificant iNOS expression was observed in all of the groups, and it was particularly low in the control and drug combination groups. NO production was also found to be significantly high after docetaxel treatment, and cell proliferation decreased after doxorubicin treatment. In conclusion, chemotherapy influences NOS activity differently with the presence of different drugs. The results with iNOS show that doxorubicin is a more effective drug than docetaxel, and a drug combination may play a helpful role in the suppression of tumorigenicity and cancer metastasis. Interestingly, eNOS expression increased after the addition of both docetaxel and the drug combination, and it was found to negatively correlate with the histological grade of the tumor. Therefore, analyzing the expression of both iNOS and eNOS might be very useful for targeting the treatment of breast carcinoma and obtaining better information on prognosis. Copyright © 2006 Cognizant Comm. Corp.
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    The effect of melatonin on a dorsal skin flap model
    (Informa Healthcare, 2014) Kerem H.; Akdemir O.; Ates U.; Uyanikgil Y.; Sezer E.D.; Bilkay U.; Turgut M.; Sozmen E.; Songur E.
    Background: Melatonin (Mel) has a very potent antioxidant activity, depending mainly on its capacity to act as an electron donor. Recently, the antioxidant property of Mel has been much emphasized. In this study, the dorsal skin flap model was used to investigate the effect of Mel in flap viability in rats. Material and Methods: Totally 28 Wistar Albino rats were divided into four groups: control group (C) (n = 7), local treatment group (L) (n = 7), systemic low-dose melatonin treatment group (LT) (n = 7), and systemic high-dose melatonin treatment group (HT) (n = 7). The necrosis rate of the skin flaps was observed seven days after the operation by a blinded observer. Oxidative stress was assessed by determining malondialdehyde (MDA) level, and effects of melatonin on antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) were measured. Vascularity, epithelial thickness, and fibroblast proliferation of dorsal skin flaps were assessed histologically. Results: Amount of MDA were found significantly lower (p < .05), and the flap viability, CAT, SOD, vascularity, fibroblast proliferation, and epithelial thickness were found significantly higher (p < .05) in groups HT than in groups C, L, and LT statistically. Conclusion: Our results showed that the usage on different doses of melatonin could play an important role in the process of flap viability and further studies will focus on these areas of interest. © 2014 Informa Healthcare USA, Inc.
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    Comparison of nephron-protective effects of enalapril and glp analogues (exenatide) in diabetic nephropathy
    (Georg Thieme Verlag, 2014) Çavusoglu T.; Erbas O.; Karadeniz T.; Akdemir O.; Acikgoz E.; Karadeniz M.; Tuglu M.I.; Ates U.
    Background: One of the major concerns is a nephropathy in diabetes, which applies many different kinds of medicines. However, required level of the treatment of renal disease has not been achieved. Aim: To investigate and compare the effect of the enalapril and the exenatide on diabetic nephropathy in rats developed diabetes by streptozosin. Material and Methods: 32 male Sprague Dawley rats were divided into 4 groups: (1) Control, (2) Diabetic (DM), (3) DM+ Enalapril, and (4) DM+ exenatide groups. Then, the animals were euthanized and their blood samples were collected by cardiac puncture for blood glucose; blood urea nitrogen (BUN), creatinin, and nephrectomy were performed for histopathologic examination, and urine samples were taken on stick for proteinuria. Results: Administration of the enalapril or the exenatide in diabetic rats resulted in a significant reduction both fibronectin, induced nitric oxide synthase (i-NOS) expression in glomerular area and urine protein levels. It was shown that both of enalapril and exenatide protected the renal glomerulus more than diabetic group in the nephropathy histopathologically. Conclusion: The beneficial effects of enalapril and exenatide which reduces fibronectin, i-NOS expression and urine protein levels or increases recovery of glomerules, might be used for preventing the harmful effects of diabetic nephropathy. © 2014 Georg Thieme Verlag KG Stuttgart New York.
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    Experimental comparison of protective characteristics of enalapril and trimetazidine in diabetic nephropathy
    (Informa Healthcare, 2014) Karadeniz T.; Cavusoǧlu T.; Turkmen E.; Uyanikgil Y.; Karadeniz M.; Akdemir O.; Tuglu M.I.; Ates U.; Erbas O.
    Hyperglycemia, hypertension, dyslipidemia, and inflammation have been proposed to account for the development of nephropathy in diabetic subjects. The beneficial effects of enalapril on diabetic nephropathy are known. However, the effects of trimetazidine (TMZ) are still unknown. We aimed at comparing the effects of the enalapril and TMZ treatment on fibronectin expression, inducible nitric oxide synthase expression, urine proteinuria, blood glucose and glomerular, and mesangial structures of kidney in rats that take streptozotocin (STZ). In this study, 32 male Sprague-Dawley albino mature rats of 8 weeks, weighing 200-220 g were used. Diabetes was induced by intraperitoneal injection of STZ (60 mg/kg) for 24 rats. We made four groups (Group 1: control, non-diabetic rats (n = 8), Group 2: diabetes, without treatment (n = 8), Group 3: diabetes treatment with enalapril (n = 8), Group 4: diabetes treatment with TMZ (n = 8). The positive effects of renal tissue and tubules in the mesangium immunohistochemical were shown in TMZ receiving rat groups. These positive effects were in parallel with the reduction in fibronectin and I-NOS expression and reduction in the proteinuria. TMZ and enalapril treatment of diabetic rats and renal parenchyma in this study are shown to have positive effects on the different levels. © 2014 Informa Healthcare USA, Inc. All rights reserved.
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    The Protective Effect of Losartan on Diabetic Neuropathy in a Diabetic Rat Model
    (Georg Thieme Verlag, 2015) Cavusoglu T.; Karadeniz T.; Cagiltay E.; Karadeniz M.; Yigitturk G.; Acikgoz E.; Uyanikgil Y.; Ates U.; Tuglu M.I.; Erbas O.
    Aim: Involvement of the peripheral and autonomic nervous systems is possibly the most frequent complication of diabetes. Important risk factors included hyperglycemia, dyslipidemia, hypertension, and smoking. Angiotensin-converting-enzyme inhibitor (ACE) inhibitors should be beneficial in all vascular beds, including neuropathy and retinopathy. In this study we aimed to evaluate the effect of the angiotensin receptor blocker losartan on diabetic neuropathy in a diabetic rat model. Material and Methods: 24 male, Sprague Dawley albino mature rats were divided into 3 groups; (1) control group: No drug was administered to the remainder of rats which blood glucose levels were under 120mg/dl, (2) diabetic control: rats were given no medication, but 4ml per day of tap water was given by oral gavage, (3) losartan groups: rats were given 10mg/kg/day oral of losartan for 4 weeks. Electromyography (EMG) was applied to anesthetized rats at the end of 4th weekend. Then, the animals were euthanized and sciatic nerve was performed for histopathological examination. Results: Compound Muscle Action Potential (CMAP) amplitude of diabetic rats receiving the Saline in the EMG was significantly reduced when compared to the control group. Distal latency value and CMAP duration of diabetic rats receiving the saline were meaningfully increased when compared to the control group. CMAP amplitude and CMAP duration of diabetic rats receiving the Losartan treatment in the EMG were meaningfully reduced when compared to diabetic rats receiving the Saline. Perineural thickness in the rats receiving the Losartan treatment was found to be significantly reduced when compared to the group receiving the Saline. Conclusions: As a result, it has been shown in this study that perineural thickness of the Losartan treatment was significantly reduced when compared to saline receiving group, significantly increased the immunoexpression of NGF, and also provided a significantly recovery in EMG when compared to Saline receiving group. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart, New York.