A. Alev Karagözler

Electrochemical synthesis and sensor application of poly (1,4-diaminobenzene)

This paper describes a novel polymeric matrix, poly (p-phenylenediamine), as glucose oxidase entrapment media for amperometric glucose determination. The glucose sensor was constructed in a one-step procedure by anodic electropolymerization of p-phenylenediamine and concomitant incorporation of glucose oxidase at a potential of 0.7 V versus Ag/AgCl. Results show that the new glucose sensor has a linear range up to 6 mM, fast response time (less than 4 s) and high sensitivity. The specificity of the enzyme electrode for possible interfering species such as lactose, sucrose and urea was tested, and no discernible anodic signal was detected above the background current. Moreover, the effects of pH and temperature on the amperometric response were systematically investigated and the activation energy for enzymatic reaction was calculated as 41 kJ/mol. Also, the biosensor was found to be stable for more than 30 days.

Relationship among placental cadmium, lead, zinc, and copper levels in smoking pregnant women

Previous studies on Cd-exposed pregnant animals have reported a Cd−Zn interaction that result in increased placental Cd levels and decreased placental Zn transport. In this study, placental Cd, Pb, Cu, and Zn status in pregnant women exposed to Cd and Pb through cigaret smoke was investigated. Placental tissues obtained from 30 nonsmokers (controls), 70 passive smokers, and 90 smokers were analyzed for Cu and Zn levels using an atomic absorption spectrophotometer and for Pb and Cd levels using an EG&G PARC Model 303A hanging mercury drop electrode. The result showed that whereas the placental Cd and Pb levels in smokers were higher that those of nonsmokers, Cu and zinc levels were lower in nonsmokers. These results imply that smoking during pregnancy could be harmful for both the mother and the fetus.

Molecularly imprinted cryogels for carbonic anhydrase purification from bovine erythrocyte

Abstract Molecularly imprinted PHEMAH cryogels were synthesized and used for purification of carbonic anhydrase from bovine erythrocyte. Cryogels were prepared with free radical cryopolymerization of 2-hydroxyethyl methacrylate and methacryloylamido histidine and characterized by swelling degree, macroporosity, FTIR, SEM, surface area and elemental analysis. Maximum carbonic anhydrase adsorption of molecularly imprinted PHEMAH cryogel was found to be 3.16 mg/g. Selectivity of the molecularly imprinted cryogel was investigated using albumin, hemoglobin, IgG, γ-globulin, and lysozyme as competitor proteins and selectivity ratios were found to be 15.26, 60.05, 21.88, 17.61, and 17.42, respectively. Carbonic anhydrase purity was demonstrated by SDS-PAGE and zymogram results.

Comparison of the chemopreventive potentials of melatonin and vitamin E plus selenium on 7,12-dimethylbenz[a]anthracene-induced inhibition of mouse liver antioxidant enzymes.

Chemoprevention is a rapidly growing area of oncology that is identifying agents with a potentially preventive role in cancer. In this study, it was our goal to compare the chemopreventive effects of vitamin E plus selenium, and melatonin. Forty female mice were divided into four equal groups. The first group served as control. The second group had i.p. injections of 7,12-dimethylbenz[a]anthracene (DMBA) (20 mg/kg body weight) in corn oil for 21 days. The third group had the same procedure of DMBA injections as the second group and received vitamin E+selenium (90 μg+1.8 μg/day), simultaneously. The fourth group had DMBA injections and melatonin (4.2 mg/kg body weight), simultaneously. DMBA alone caused significant inhibition of hepatic glutathione peroxidase (GSHPx), catalase (CAT), and superoxide dismutase (SOD) in the second group. In the third group, vitamin E+selenium restored DMBA-induced GSHPx inhibition significantly whereas CAT and SOD inhibition remained essentially unchanged. In the fourth group, melatonin not only significantly decreased DMBA-induced GSHPx inhibition but also fully reversed CAT and SOD inhibitions caused by DMBA. We speculate that melatonin alone provides better chemoprevention against DMBA-induced oxidative stress than the vitamin E+selenium combination.

Investigation of the blood biochemical status of gas station workers

The aim of this study was to examine occupation-associated effects on blood cytokine and immunoglobulin g (IgG) levels, antioxidant enzyme activities (SOD, GSHPx, and catalase), nitrite and nitrate levels, and malondialdehyde (MDA) concentrations in gas station workers (GSWs). Trace elements (Cu, Zn, and Pb) in serum, and the amount of hemoglobin in erythrocytes were also determined. Forty male GSWs and 30 male controls were included in the study. No significant difference was observed between the hemoglobin levels of GSWs and those in controls. Proinflammatory cytokine levels, such as tumor necrosis factor-α and interleukin-8 were significantly increased in GSWs’ sera. Interleukin-1β and interleukin-6 were below the detection limit of the assay in both the groups. Cytokine receptor interleukin 2R concentration and IgG levels were also significantly increased. Approximately, two-fold increase in nitrite and nitrate concentrations was found in GSWs’ sera. Erythrocyte antioxidant enzyme levels were significantly lower in GSWs’ blood. MDA concentration, a measure of lipid peroxidation, was found to be significantly elevated. Zn levels were significantly decreased, whereas Cu and Pb levels were increased in GSWs’ sera. Smoking was not found to be a major confounder for the association between exposure and blood parameters.