Handan Ak Celik

TLR-2 gene Arg753Gln polymorphism is strongly associated with acute rheumatic fever in children

The recently described family of toll-like receptors (TLRs) is a key player in host immunity by mediating inflammatory reactions against a wide range of pathogens. Mutations and polymorphisms in TLRs have revealed the importance of TLRs in human defence against diseases. TLR-2 is reported to interact with different bacterial structures, including lipoproteins, peptidoglycan and lipoteichoic acid. To assess the role of TLR-2 gene polymorphism in acute rheumatic fever (ARF) etiopathology, 61 independent Caucasian Turkish patients and 91 child and 116 adult controls were studied. Antistreptolycin O, C-reactive protein, sedimentation and white blood cell counts were studied to evaluate the clinical characteristics of the patients. Genomic DNA was extracted from peripheral blood using a standard column extraction technique. The Arg753Gln and Arg677Trp polymorphisms were genotyped by polymerase chain reaction (PCR) restriction fragment length polymorphism. The PCR products for the TLR-2 gene were analysed on 1.5% agarose gel pre-stained with ethidium bromide. Compared with healthy adult controls, the Arg753Arg genotype was significantly decreased in the entire group of ARF cases [odds ratio (OR) 0.01, 95% confidence interval (95% CI) 0.0034–0.031, p<0.0001]. Significantly, ARF patients were just 16 times more frequent with Gln allele (OR 15.6, 95% CI 7.87–30.8, p<0.0001). Moreover, evidence for an intensifying effect of the Gln allele was noteworthy when patients with Arg753Gln genotype were compared with healthy controls (OR 97.1, 95% CI 32.5–290, p<0.0001). However, no Arg677Trp polymorphism was detected in either patients or controls. Our data suggest that there is strong evidence for the biological role of TLR-2 in ARF. The common TLR-2 Arg to Gln polymorphism at position 753 significantly contributes to the pathogenesis of ARF. These results will allow the construction of a profile of individuals prone to ARF and may assist in developing new therapies.

Inhibition of renin-angiotensin system in experimental acute pancreatitis in rats: a new therapeutic target?

OBJECTIVE Pancreatic renin-angiotensin system has been implied to play a role in the regulation of pancreatic functions and could be a new therapeutic target in acute pancreatitis. The aim of this study was to evaluate the therapeutic potential of angiotensin-converting-enzyme inhibition by captopril and angiotensin II type 1 receptor inhibition by L-158809 and losartan experimentally in acute pancreatitis. DESIGN Rats were randomly divided into 15 groups. Acute edematous pancreatitis was induced by injection of cerulein 20microg/kg SC four times at hourly intervals. Severe necrotizing pancreatitis was induced by retrograde injection of 3% taurocholate into the biliary-pancreatic duct. INTERVENTIONS Captopril, L-158809 and losartan were given intraperitoneally. Main outcome features: pancreatic pathology, pancreatic myeloperoxidase activity and serum amylase activity were assessed. RESULTS Captopril decreased serum amylase (10,809+/-1867 vs. 4085+/-1028U/L, p<0.01), myeloperoxidase activity (3.5+/-0.5 vs. 1.5+/-0.1, p<0.05) and histopathological score (5.0+/-0.4 vs. 1.1+/-0.5, p<0.01) in acute edematous pancreatitis. In taurocholate induced severe necrotizing pancreatitis captopril ameliorated histopathological score (10.1+/-1.2 vs. 3.4+/-0.5, p<0.01), pancreatic parenchymal necrosis (4.5+/-0.6 vs. 0.0+/-0.0, p<0.001), fatty necrosis (2.8+/-0.9 vs. 0.1+/-0.1, p<0.01) and edema (2.1+/-0.3 vs. 1.4+/-0.3, p<0.05). However, L-158809 did not have similar beneficial effects on acute pancreatitis in rats while losartan decreased pancreatic parenchymal necrosis and neutrophil infiltration. CONCLUSIONS This study not only demonstrated the differential effects of captopril, losartan and L-158809 in acute pancreatitis but also showed that there is still much to investigate about pancreatic renin-angiotensin system. Inhibition of angiotensin-converting enzyme should be evaluated carefully as a potential new therapeutic target in acute pancreatitis.

Characterization of the Cellular Response During Apoptosis Induction in Cadmium-Treated Hep G2 Human Hepatoma Cells

Cadmium is a toxic transition heavy metal of continuing occupational and environmental concern, with a wide variety of adverse effects on regulation of gene expression and cellular signal transduction pathways. Injury to cells by cadmium leads to a complex series of events that can culminate in the death of the cell. It has been reported that cadmium induces apoptosis in many cell lines. However, the morphological characteristics leading to apoptosis or subsequent regeneration in cells exposed to cadmium have not been clarified.We evaluated whether human hepatoma cells maintained in culture undergo apoptosis when exposed to cadmium. Cytotoxic activity of cadmium on Hep G2 cells determined using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. A DNA ladder assay was performed by electrophoresis. Cell cycle analysis was quantified by flow cytometry. Nuclear morphology was studied by fluorescence microscopy after staining with propidium iodide and Hoechst 33342. Morphologic alterations in culture hepatocytes treated with CdCl2 were observed by transmission electron microscopy.We have demonstrated that apoptosis is a major mode of elimination of damaged HepG2 cells in cadmium toxicity and it precedes necrosis.

Trace elements analysis of ascitic fluid in benign and malignant diseases

OBJECTIVES To evaluate differences in ascitic fluid trace element concentrations which might be useful in discrimination between benign and malignant ascites. DESIGN AND METHODS The concentrations of copper, zinc, magnesium and iron in ascitic fluid and venous blood in 17 patients were investigated. The relationship between these trace elements and type of disease were examined. Investigations were carried out in a group of 5 males and 5 females aged 54 to 77 yr who had cirrhosis ascites and in a group of 7 females aged 41 to 76 yr with ascites due to gynecologic neoplasms. RESULTS The mean ascitic fluid and serum concentrations of copper were significantly higher in neoplastic diseases compared to benign disease states (118,43 vs. 97,50, 91,14 vs. 26.90) (p < 0,05 and p < 0,01 respectively). The zinc levels in ascitic fluid and serum were significantly different between the groups (p < 0,01). Neoplastic patients had significantly higher ascitic fluid magnesium levels than the benign disease group (2,17 vs. 1,55, p < 0,001). The serum levels of iron were significantly lower in the neoplastic diseases group (92, 28 vs. 255, p < 0, 01). In benign diseases the concentration of zinc in ascitic fluid correlated positively with ascitic fluid copper concentrations. The concentrations of zinc and iron in malignant ascites correlate positively with the magnesium concentrations. Statistically significant negative correlations were found between ascites zinc and magnesium and magnesium and copper in cirrhotic patients and magnesium and copper in malignant diseases. CONCLUSIONS The results showed that zinc, magnesium and iron levels were significantly different between cirrhotic and neoplastic illness. Analysis of serum and ascitic fluid trace element composition may be helpful in identifying and distinguishing the malignant and nonmalignant ascites and provides useful information on processes regulating passage of blood components into the peritoneal cavity.

Effects of mast-cell stabilization in cerulein-induced acute pancreatitis in rats

SummaryAim. In this study we aimed to clarify the role of mast cells in the development and progression of inflammation in cerulein-induced acute pancreatitis (AP) in rats. We have also examined the effects of ketotifen; a mast-cell stabilizing agent in the treatment of acute pancreatitis and its relation with nitric oxide (NO) synthesis.Methods. In the first part of the study we planned to examine the effects mast cell stabilization in acute pancreatitis, while the second part was focused on examining the relation between NO synthesis and the potential effects of ketotifen in AP. Wistar albino rats were randomly divided into 6 groups (n: 10). In the first part of the study, AP was induced by four subcutaneous (sc) injections of 20 µg/kg body weight of cerulein at hourly intervals in Groups A and B while Group C was treated with saline as the control group. Group B was pretreated with ketotifen 1 mg/kg (ip). In the second part, the study design was similar except for the inhibition of nitric oxide synthesis by N-nitro L-arginine methyl ester (L-NAME) 30 mg/kg (ip) in Groups D, E and F. Group D was treated with L-NAME and cerulein and Group E was treated with ketotifen, L-NAME and cerulein. Group F was treated with L-NAME and saline as the control group. Serum amylase activity and pancreatic myeloperoxidase activity (MPO) were measured. Pancreatic histology and mast-cell count in pancreatic tissue were evaluated.Results. Mast cell count was found to be increased in the pancreatic tissue in cerulein-induced AP. (2.93±0.26 vs 1.98±0.26; p<0.001). Ketotifen treatment significantly reduced cerulein induced edema (1.30±0.21 vs 0.70±0.15; p<0.001), neutrophil infiltration (1.50±0.16 vs 0.60±0.16; p<0.001) and attenuated the increase in amylase (4394.0±149.5 U/L vs 3350.5±216.9 U/L; p<0.05) and MPO activity (1.14±0.13 U/gr tissue vs 0.54±0.08 U/gr tissue; p<0.001). Mast-cell count in pancreatic tissue was also decreased significantly with ketotifen pretreatment (2.93±0.26 vs 1.70±0.21; p<0.05). Inhibition of NO synthesis with L-NAME treatment decreased the beneficial effects of ketotifen.Conclusion. It seems likely that mast cell activity may play an important role in the initiation and progression of acute pancreatitis. Ketotifen treatment may reduce the severity of AP in rats. The protective action of ketotifen in cerulein-induced acute pancreatitis is most probably owing to mast cell stabilization and stimulation of NO synthesis.

The interaction between antioxidant status and cervical cancer: a case control study.

AIMS AND BACKGROUND To compare the antioxidant status of cervical cancer patients with healthy controls and to assess the antioxidant levels before and after radiotherapy or radiochemotherapy. METHODS AND STUDY DESIGN Antioxidant levels (glutathione, glutathione peroxidase, superoxide dismutase, and malondialdehyde) were measured in 35 patients with cervical cancer and 35 age-matched healthy controls. Blood samples were collected twice (before and after treatment) from cervical cancer patients and once from healthy control subjects. RESULTS In the patient group, pre-radiotherapy glutathione and glutathione peroxidase levels were significantly lower (P <0.01 and P <0.0001, respectively) than the control group. Pre-radiotherapy levels of superoxide dismutase were significantly higher in cancer patients (P <0.01). In general, no difference was observed between pre- and post-radiotherapy antioxidant levels in cancer patients. However, when post-radiotherapy glutathione levels were analyzed, patients who did not respond to treatment had significantly higher levels than those who did respond (P <0.01). CONCLUSIONS Levels of antioxidants significantly differed between the patients with cervical cancer and the controls, and no change in antioxidant levels was observed after treatment. Moreover, further studies evaluating the predictive value of glutathione levels on treatment response are warranted.

Sodium selenite protects against diabetes-induced alterations in the antioxidant defense system of the liver.

Free radical genesis of disorder is one of the major subjects of discussion in the explanation of pathological conditions. In this study, the effects of micro molar quantities of sodium selenite treatment on diabetes‐induced alterations in the antioxidant defense system were investigated.

Biochemical and morphological characteristics of selenite-induced apoptosis in human hepatoma hep G2 cells

Selenium is a cellular growth inhibitor in many mammary tumor cells. To comprehend the mechanism for the selenium-induced cell death, we examined the effects of sodium selenite, which has been one of the most extensively investigated selenium compounds, in human hepatoma Hep G2 cells.Cell viability gradually decreased after treatment with sodium selenite within the concentration range of 10–50 µM. Low (10 µM) selenite has shown a high-percentage laddering pattern compared to the high (25 µM) cytotoxic selenium concentration in agarose gel electrophoresis. G2M-phase enrichment was also concentration dependent. The most consistent transmission electron microscopic finding was the existence of large lysosomes.Based on these data, we hypothesize that sodium selenite predominantly shows its apoptotic effect over hydrogen selenite accumulation.

Polymorphisms in the activin A receptor type 2A gene affect the onset time and severity of preeclampsia in the Turkish population

Abstract Aim: To investigate the possible roles of selected single nucleotide gene polymorphisms (SNPs) of the activin A receptor type 2A (ACVR2A) gene in the pathogenesis of preeclampsia. Methods: Ninety-four patients with preeclampsia and 166 healthy pregnant women were included in this study. Genomic DNA was extracted from venous blood and were stored at −80°C before the analysis. Selected ACVR2A SNPs (rs10497025, rs1128919, rs13430086) were determined in an ABI 7900 HT Real-Time PCR instrument. Results: For all three SNPs, no statistically significant difference was found between preeclampsia and control groups in terms of genotype and allele frequencies. In the late preeclampsia group, with regard to the rs1128919 SNP, the frequency of GG genotype was found to be significantly lower (P=0.02). Although the frequency of “A” allele was found to be higher (P=0.05; OR=1.54), and the “G” allele was found to be lower (P=0.05; OR=0.65), the results did not reach statistical significance in late preeclamptic patients. For the rs1128919 SNP, the frequency of the AA genotype was found to be significantly higher in both mild (P=0.004) and severe (P=0.0001) preeclampsia groups, whereas the frequency of GG genotype was found to be significantly lower (P=0.008, and P=0.0001, respectively). For the rs13430086 SNP, while the frequency of the AA genotype was found to be significantly lower in both mild (P=0.02) and severe (P=0.0001) preeclamptic patients, the frequency of TT genotype was found to be significantly higher in only severe preeclampsia group (P=0.0001). Conclusion: ACVR2A gene polymorphisms may play a role in the development of preeclampsia.

Determination of the effects of Alcohol Dehydrogenase (ADH) 1B and ADH1C polymorphisms on alcohol dependence in Turkey

Alcoholism is a complex genetically influenced disorder which refers to alcohol abuse and alcohol dependence. There are controversial results on the role of gene polymorphisms in alcohol dependence in the literature. Differences in population groups and selective inclusion criteria for alcohol dependence may affect results. In this study, we investigated the role of ADH1B Arg48His (rs1229984) and, ADH1C Ile350Val (rs698) gene polymorphisms in Turkish population. 100 healthy volunteers and 75 patients who were admitted to Ege University Alcohol Dependence Unit enrolled in the study. We found significant increase both in ADH1B (Arg48His) polymorphism Arg allele and Arg/Arg genotype frequency in patients. No profound connection between alcohol dependence and ADH1C Ile350Val gene polymorphism was detected. Alcohol dependence is an important health problem that depends on many genetic and environmental factors but we think that it is possible to interpret genetic risk for developing early diagnostic methods and treatment strategies by comprehensive linkage and association studies.