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Dive into the research topics where Mehmet Ozaslan is active.

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Featured researches published by Mehmet Ozaslan.


The American Journal of Chinese Medicine | 2007

In vivo Antitumoral Effect of Plantago major L. Extract on Balb/C Mouse with Ehrlich Ascites Tumor

Mehmet Ozaslan; I. Didem Karagöz; M. Emin Kalender; I. Halil.Kilic; Ibrahim Sari; Alper Karagöz

The aim of this study is to investigate the antitumor activity of Plantago major L. extract in Ehrlich ascites tumor (EAT) bearing Balb/C mice in vivo. Thirty male Balb/C mice were divided into 5 groups: 3 treatment groups and 2 control groups (6 per group). Treatment groups and the negative control group were injected with EAT (1 x 10(6) cells) intraperitoneally to develop ascites tumor. P. major L. extract (1%, 2% and 3% concentration extracts, 0.1 ml/day/mouse) were given p.o. for 10 alternate days. The control group was treated with 0.9% NaCl solution (0.1 ml/day/mouse). The changes of body weight in animals were recorded. On the 11th day, all of the mice were sacrified and their tissues were stained with haematoxylen and eosin for pathological studies. Body weights of in 3 treatment groups and the negative control group were elevated because of tumor burden. The maximal weight gain was recorded in the negative control group and the minimal weight gain was recorded in Group I. Pathological studies showed that P. major L. extract (especially 1% concentration) has inhibitive effect on EAT. P. major has an inhibitory effect on EAT in a dose dependent manner.


Journal of Genetics | 2007

Mutations in the S gene region of hepatitis B virus genotype D in Turkish patients

Mehmet Ozaslan; Ersan Özaslan; Arzu Barsgan; Mehmet Koruk

The S gene region of the hepatitis B virus (HBV) is responsible for the expression of surface antigens and includes the ‘a’-determinant region. Thus, mutation(s) in this region would afford HBV variants a distinct survival advantage, permitting the mutant virus to escape from the immune system. The aim of this study was to search for mutations of the S gene region in different patient groups infected with genotype D variants of HBV, and to analyse the biological significance of these mutations. Moreover, we investigated S gene mutation inductance among family members. Forty HBV-DNA-positive patients were determined among 132 hepatitis B surface antigen (HbsAg) carriers by the first stage of seminested PCR. Genotypes and subtypes were established by sequencing of the amplified S gene regions. Variants were compared with original sequences of these serotypes, and mutations were identified. All variants were designated as genotype D and subtype ayw3. Ten kinds of point mutations were identified within the S region. The highest rates of mutation were found in chronic hepatitis patients and their family members. The amino acid mutations 125 (M → T) and 127 (T → P) were found on the first loop of ‘a’-determinant. The other consequence was mutation inductance in a family member. We found some mutations in the S gene region known to be stable and observed that some of these mutations affected S gene expression.


Biotechnology & Biotechnological Equipment | 2005

Effect of Explant Source on in Vitro Propagation of Paulownia Tomentosa Steud.

Mehmet Ozaslan; C. Can; Turkan Aytekin

ABSTRACT Shoot tip, leaf with petiole, nodal stem and root explants of in vitro germinated seedlings of Paulownia tomentosa Steud. were cultured on Murashige and Skoog (MS) medium combined with 1-naphthaleneaceticacid (NAA)/6-benzylaminopurine (BAP), indole3-aceticacid (IAA)/BAP or IAA/Kinetin. Nodal stem explants were found to be an excellent explant source to induce direct ogranogenesis. The highest number of shoot regeneration from stem explants was obtained on MS medium supplemented with 0.1 mg.l−1 IAA+3.0 mg.l−1 BAP. Rooting was induced on MS basal or MS containing NAA+IAA combinations. The rooted plantlets were transferred to potting soil and adopted to greenhouse conditions.


Cancer Genetics and Cytogenetics | 2010

Deletion mapping of chromosome region 12q13-24 in colorectal cancer.

Turkan Aytekin; Mehmet Ozaslan; Beyhan Cengiz

Colorectal cancer is one of the most common cancers in the world. Colorectal cancer develops after a long and multistep process of carcinogenesis. Inactivation of tumor suppressor genes is among the most important steps in development of colorectal cancer. Analysis of loss of heterozygosity (LOH) is an effective method to determine the localization of tumor suppressor genes. In this study, we used five microsatellite markers to analyze the region 12q13-24 among 47 patients with colorectal cancer. The frequency of LOH and the clinicopathological data were compared using logistic regression and a chi-square test. In 34 of 47 tumor tissues (72%), LOH was detected at least in one marker. The highest LOH frequency was 34%, on the D12S129 locus; the lowest frequency was 23%, on the D12S78 locus. Loss of heterozygosity was detected as 32% on D12S83, 30% on D12S346, and 26% on D12S1660. No statistically significant correlation was found between the frequency of LOH and clinicopathological features (P > 0.05). Chromosome region 12q13-24 contains several known genes that may be candidate tumor suppressor genes, including RASAL1, ITGA7, STAB2, GLIPR1, and SLC5A8. Although the exact roles of these genes in colorectal cancer formation remain to be clarified, the present data point to a tumor suppressor role.


Acta Physiologica Hungarica | 2008

Occupational lead exposure effect on liver functions and biochemical parameters

S. Can; Cahit Bagci; Mehmet Ozaslan; A.I. Bozkurt; Beyhan Cengiz; E.A. Cakmak; Ramazan Kocabas; E. Karadağ; Mehmet Tarakcioglu

The effect of occupational lead exposure on the liver function and on the blood biochemical parameters among the battery workers and the muffler repair workers was studied. The study included 22 battery and 38 muffler repair workers. Whole blood lead levels were determined by atomic absorption spectrophotometers. Total protein, albumin, globulin, cholesterol, triglyceride, total bilirubin, aspartate transaminase (AST), alanine transaminase (ALT), gamma glutamyltransferase (GGT), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) levels were determined in the serum by spectrophotometry. The blood lead levels of the battery workers, muffler repair workers, and the controls were found to be 36.83 +/- 8.13 microg/dL, 26.99 +/- 9.42 microg/dL, and 14.81 +/- 3.01 microg/dL, respectively. Blood lead levels of the workers were significantly higher than those of controls (p < 0.001). The lead level of the battery workers was also significantly higher than that of muffler repair workers (p < 0.001). Although, statisticly significant, higher blood lead levels are not related to toxicity for battery and muffler repair workers. Total protein, globulin, cholesterol, LDH, and ALP levels were within normal levels, however, they were slightly higher than the control levels. Increased LDH among the workers seems to be related rather to other causes than to the liver injury.


Tumor Biology | 2010

CDC25A gene 263C/T, -350C/T, and -51C/G polymorphisms in breast carcinoma

Isik Didem Karagoz; Mehmet Ozaslan; Beyhan Cengiz; Mehmet Emin Kalender; Ibrahim Halil Kilic; Serdar Oztuzcu; Bulent Gogebakan; Abdullah T. Demiryürek

The family of cell division cycle 25 (CDC25) phosphatase is one of the important regulators of the cell cycle progression. In mammalian cells, three isoforms have been identified: CDC25A, CDC25B, and CDC25C. CDC25A is required to enter S time, and the overexpression of this phosphatase accelerates the entrance to S time. CDC25A overexpression could render tumor cells less sensitive to DNA replication checkpoints, thereby contributing to their genomic instability. We aimed to investigate, for the first time, the frequency of human CDC25A gene SNPs in metastatic and non-metastatic breast cancer. Total number of 281 eligible patients with histologically confirmed incident of breast cancer and 137 cancer-free controls were included. The detection of CDC25A gene polymorphisms was achieved with real-time polymerase chain reaction and restriction fragment length polymorphism techniques. We found that the 263C/T polymorphism was significantly associated with breast cancer and risk of metastasis. The -350C/T polymorphism in the promoter region of CDC25A gene was found to associate with neither breast cancer nor metastasis. The other promoter polymorphism -51C/G in the CDC25A gene associated with breast cancer but not associated with metastasis. These data suggest that 263C/T and -51C/G polymorphisms of CDC25A gene could be candidate markers for earlier diagnosis and targets for breast cancer therapy.


Biotechnology & Biotechnological Equipment | 2010

Oxidant/Antioxidant Status of Patients with Diabetic and Senile Cataract

S. N. Aksoy; B. Gurler; Asude Aksoy; S. Nur Aksoy; Mehmet Ozaslan

ABSTRACT The aim of the present study is to evaluate the relationship of total antioxidant capacity, total oxidant status, oxidative stres and total free sulfydryl groups in patients with diabetic and nondiabetic senil cataract. The study was carried out on venous blood samples from 70 subjects admitted to the ophtalmology clinic of a research hospital. Of these, 25 were senile Type 2 diabetic patients with cataract who were using oral hypoglycemic agents or insülin. Fourty-five patients with nondiabetic senile cataract comprised the control group. Total oxidant status (TOS), total antioxidant capacity (TAC) and total free -SH levels were measured in sera of patients with cataract. Serum TAS and TOS levels were determined using a novel automated measurement method. Oxidative status was determined using TAC and TOS measurement and with the calculation of oxidative stres index. TOS and OSI levels were significantly higher in diabetic cataract than senile cataract (p=0.008, p=0.013), respectively. TAC and total free -SH levels were similiar in the two groups (p = 0.17, p=0.54). Free sulfydryl groups levels are consistent with TAC. The results of present study suggest that TOS and intensity of the oxidative stress in diabetic patients are higher, compared to other age-related cataract patients without diabetes. Since oxidative stress is important in development of diabetic complications, increased TOS and oxidative stress might have a role in the pathophysiology of diabetic cataract.


Biotechnology & Biotechnological Equipment | 2006

Two Species of Genus Xerolycosa (Araneae: Lycosidae) New to the Turkish Spider Fauna

I. Varol; Mehmet Ozaslan; A. Özdemir; Z. Akan; F. Kutbay

ABSTRACT Two species, Xerolycosa nemoralis (Westring, 1861) and X. miniata (C. L. Koch, 1834) were added Turkish spider fauna as the new records. The definitions, distributions, ecologies, genital structures and identification keys of these species were described according to literature.


Biotechnology & Biotechnological Equipment | 2015

Hepatoprotective effect of diffractaic acid on carbon tetrachloride-induced liver damage in rats

Isik Didem Karagoz; Mehmet Ozaslan; Ibrahim Halil Kilic; Izzettin Guler; Ceyda Uyar; Dilara Tuter; Ulku Kazanci; Ali Aslan; Ahmet Cakir; Sevgi Gezici

This study was designed to investigate the hepatoprotective effect of diffractaic acid isolated from a lichen species, Usnea longissima, at 3 doses, 50, 100 and 200 mg/kg, against carbon tetrachloride (CCl4)-induced hepatic damage. For this purpose, 40 Wistar albino rats were divided in 5 groups, including 3 experimental and 2 control ones, and 0.2 mL/kg of CCl4 in olive oil (1:5 v/v) was injected daily for 6 weeks intraperitoneally. After the liver injury, diffractaic acid was applied at doses of 50, 100 and 200 mg/kg for 7 days. The group given physiologic saline (0.2 mL/kg) was used as a control group. Alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, creatinine, urea, direct and total bilirubin and C-reactive protein levels were also evaluated in the serum samples obtained from the rat groups. Liver tissues were removed and were examined histopathologically following staining with hematoxylin–eosin. The results showed that 50 mg/kg daily dose of diffractaic acid could be considered to have hepatoprotective effect by ameliorating the studied biochemical parameters and tissue histological structures. However, 100 and 200 mg/kg of diffractaic acid acted as hepatotoxin and did not show any hepatoprotective effect. Thus, diffractaic acid could be potentially used as a hepatoprotective agent at a low dose (50 mg/kg) against acute liver toxicity induced by CCl4.


Pharmacological Reports | 2014

Antitumoral effect of a selective Rho-kinase inhibitor Y-27632 against Ehrlich ascites carcinoma in mice

Derya Isler; Mehmet Ozaslan; Isik Didem Karagoz; Ibrahim Halil Kilic; Metin Karakok; Seyithan Taysi; Izzettin Guler; Ahmet Cakmak; Abdullah T. Demiryürek

BACKGROUND The Rho proteins and Rho-kinase (ROCK) enzymes are responsible for signal transduction, and cause cell permeability, contractility, differentiation, migration, proliferation or apoptosis depending on cell types. All of these functions are vital for cancer initiation and progression. In this study, the preventive and protective effects of a selective ROCK inhibitor Y-27632 against Ehrlich ascites carcinoma in Swiss albino mice were investigated. METHODS Adult male albino mice were divided into five equal groups, and Y-27632 (0.1, 1, and 10 mg/kg) was given to groups as two steps; before (pre-carcinoma) and after inoculation of carcinoma cell suspensions (post-carcinoma). At the end of the experiments (at day 15), cardiac blood samples, the ascitic fluid, and intestinal specimens were collected for histopathology and biochemical investigation. RESULTS Significant decreases in the body weight and immunostaining scores in small and large intestine for ROCK2, preservation of serum glutathione (GSH) levels, and an increase in tumor level of nitric oxide were recorded in groups pretreated with Y-27632. However, treatment with Y-27632 after tumor inoculation did not affect body weight and ROCK2 immunostaining scores, increased serum MDA levels, and decreased GSH levels. CONCLUSIONS This is the first study on the effectiveness of Y-27632 in this experimental tumor model. Our findings provided direct evidence for ROCK involvement in tumor development. These data suggest that pretreatment with Y-27632 has a protective effect against tumor formation.

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Cahit Bagci

University of Gaziantep

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Ceyda Uyar

University of Gaziantep

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Ibrahim Sari

University of Gaziantep

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Sevgi Gezici

University of Gaziantep

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Arzu Barsgan

University of Gaziantep

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