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Öğe Changes in tyrosine hydroxylase activity, adrenomedullin (ADM) and total RNA levels by treatment of organoselenium compounds in rat hypothalamus exposed to 7, 12-dimethylbenzanthracene (DMBA)(2010) Ozdemir I.; Talas Z.S.; Gok Y.; Ates B.; Yilmaz I.The effects of synthetic organoselenium compounds (Se I and Se II) on the activity of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine synthesis as well as adrenomedullin (ADM) and total RNA levels were determined in the hypothalamus of adult rats exposed to DMBA (7,12-dimeuiylbenz[a] anthracene). DMBA, an organic environmental pollutant, is a polycyclic aromatic hydrocarbon that can induce a range of toxic effects and stress in rats. Selenium is an essential trace element, which interacts with antioxidants, and has anticancer and antihypertensive properties. TH is an aromatic amino acid hydroxylase whose activity is elevated in response to a range of stress inducers. TH activity is normally regulated by negative feedback in catecholamine biosynthesis. ADM is an abundantly present peptide in a broad range of normal tissues including adrenal medulla, lungs, kidneys and brain. Plasma ADM levels are elevated in a number of diseases including essential hyptertension and chronic renal failure. The antioxidant properties of ADM offer protection against organ damage induced by high blood pressure, ischemia and aging. DMBA treatment increased the TH activity and ADM level in the hypothalamus. These increases were found to be inhibited by Se I and Se II treatments. These studies demonstrate that synthetic organoselenium compounds can suppress DMBA-induced stress-related changes in the rat hypothalamus. Therefore, the antioxidant and antihypertensive effects of Se I and Se II may have important effects in the maintainance of homeostasis. © by PSP.Öğe Effect of Vitreoscilla hemoglobin on production of a chemotherapeutic enzyme, L-asparaginase, by Pseudomonas aeruginosa(2006) Geckil H.; Gencer S.; Ates B.; Ozer U.; Uckun M.; Yilmaz I.The production of L-asparaginase, an enzyme widely used in cancer chemotherapy, is mainly regulated by carbon catabolite repression and oxygen. This study was carried out to understand how different carbon sources and Vitreoscilla hemoglobin (VHb) affect the production of this enzyme in Pseudomonas aeruginosa and its VHb-expressing recombinant strain (PaJC). Both strains grown with various carbon sources showed a distinct profile of the enzyme activity. Compared to no carbohydrate supplemented medium, glucose caused a slight repression of L-asparaginase in P. aeruginosa, while it stimulated it in the PaJC strain. Glucose, regarded as one of the inhibitory sugars for the production L-asparaginase by other bacteria, was determined to be the favorite carbon source compared to lactose, glycerol and mannitol. Furthermore, contrary to common knowledge of oxygen repression of L-asparaginase in other bacteria, oxygen uptake provided by VHb was determined to even stimulate the L-asparaginase synthesis by P. aeruginosa. This study, for the first time, shows that in P. aeruginosa utilizing a recombinant oxygen uptake system, VHb, L-asparaginase synthesis is stimulated by glucose and other carbohydrate sources compared to the host strain. It is concluded that carbon catabolite and oxygen repression of L-asparaginase in fermentative bacteria is not the case for a respiratory non-fermentative bacterium like P. aeruginosa. © 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.Öğe The effects of reactive phthalocyanine blue textile dye on peroxidase activity, lipid peroxidation and total chlorophyll content of Phaseolus vulgaris L. CV. "GINA"(Parlar Scientific Publications, 2014) Kaya A.; Yigit E.; Akbulut G.B.; Ates B.In this study, the effects of Reactive Phthalocyanine Blue (RPB) changes on peroxidase, malondialdehyde (MDA) content and total chlorophyll content of Phaseolus vulgaris L. (bean) were examined. The beans were exposed to different concentrations of RPB between 200-1255 mg/L. In the analyzed plants, different effects were observed on peroxidase activity. When compared to the control group, a significant decrease was identified in the plants which were treated with RPB except for the 1255 mg/L application group. Besides the effects of RPB on MDA content were analyzed. MDA content was found to be lower in all application groups except for 439 mg/L. In addition, total chlorophyll content increased in all application groups except for 338 mg/L when compared to the control group. These findings indicated that RPB caused significant changes in peroxidase activity, MDA content and total chlorophyll. It was shown that the textile dye had a toxic effect on the plants. © by PSP.Öğe Medicinal and Biological Application of Magnetic Alloy Nanoparticles and Their Polymer Nanocomposites(Springer International Publishing, 2022) Dik G.; Ulu A.; Ates B.In recent years, there has been an increasing interest in the use of nanostructures in biomedical applications. Among these nanostructures, magnetic nanoparticles (MNPs) have been widely used because of their advantages such as large surface area, their small size, excellent magnetic behavior, and the possibility of surface modification. However, heterogeneous bimetallic nanostructures composed of the combination of two different metals are far superior to single-component nanoparticles. Especially, magnetic alloy nanoparticles (MANPs) such as those containing elements Fe, Co, and Ni show exceptional tunable soft magnetic properties, excellent chemical properties, and high thermal stability. Therefore, MANPs have many application approaches from controlled drug delivery to magnetic resonance imaging (MRI), hyperthermia for cancer treatment, water treatment, and sensors. In this chapter, the applications of MANPs and their polymer nanocomposites in medical and biological fields such as hyperthermia, bioimaging, and drug delivery are explained. Thus, thanks to this book chapter, we report the recent studies and some important points in the development of such applications. © Springer Nature Switzerland AG 2022.Öğe Modulation of DMBA-induced biochemical changes by organoselenium compounds in blood of rats(2007) Ozdemir I.; Selamoglu Z.; Ates B.; Gok Y.; Yilmaz I.The protective role of two synthetic organoselenium compounds 1-isopropyl-3-methylbenzimidazole-2-selenone (SeI) and 1, 3-di-p-methoxybenzylpyrimidine-2-selenone (SeII) was examined against the 7,12-dimethylbenz[a]anthracene (DMBA)-induced changes in biochemical parameters in blood of rats. Albino Winstar rats (150-200 g body wt) were treated with single dose of DMBA (50 mg/kg body wt) and organoselenium compounds (25 ?mol/kg) for 4 weeks at two days internal. Blood was taken from the anaesthetized rats ventricle from their hearts for biochemical analysis. Administration of DMBA resulted in elevation of urea, uric acid and creatinine levels as well as AST, ALT and LDH activities and decrease in levels of total proteins, albumin and globulin. SeI and SeII caused a significant (p<0.05) decrease in urea, uric acid and creatinine levels and alanine aminotransferase (ALT); aspartate aminotransferase; (AST) and lactate dehydrogenase (LDH) activities and significantly increased the levels of total protein and albumin (p<0.05). These organoselenium compounds are likely to be beneficial in human health.Öğe Production of L-DOPA and dopamine in recombinant bacteria bearing the Vitreoscilla hemoglobin gene(2009) Kurt A.G.; Aytan E.; Ozer U.; Ates B.; Geckil H.Given the well-established beneficial effects of Vitreoscilla hemoglobin (VHb) on heterologous organisms, the potential of this protein for the production of L-DOPA and dopamine in two bacteria, Citrobacter freundii and Erwinia herbicola, was investigated. The constructed recombinants bearing the VHb gene (vgb+) had substantially higher levels of cytoplasmic L-DOPA (112 mg/L for C. freundii and 97 mg/L for E. herbicola) than their respective hosts (30.4 and 33.8 mg/L) and the vgb- control strains (35.6 and 35.8 mg/L). Further, the vgb+ recombinants of C. freundii and E. herbicola had 20-fold and about two orders of magnitude higher dopamine levels than their hosts, repectively. The activity of tyrosine phenol-lyase, the enzyme converting L-tyrosine to L-DOPA, was well-correlated to cytoplasmic L-DOPA levels. As cultures aged, higher tyrosine phenol-lyase activity of the vgb+ strains was more apparent. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.Öğe Synthesis of Cyclodextrin-Based Multifunctional Biocompatible Hydrogels and Their Use in the Prevention of Intrauterine Adhesions (Asherman’s Syndrome) after Surgical Injury(American Chemical Society, 2024) Aksoy Erden B.; Kurus M.; Turkcuoglu I.; Melekoglu R.; Balcioglu S.; Yigitcan B.; Ates B.Asherman’s syndrome, which can occur during the regeneration of damaged uterine tissue after surgical interventions, is a significant health problem in women. This study aimed to acquire and characterize cyclodextrin-based hydrogels, which can be used to prevent Asherman’s syndrome, and investigate their effectiveness with biomedical applications. A series of hydrogels were synthesized from the cross-linking of ?-cyclodextrin and different polyphenols with epoxy-functional PEG. Their chemical, physical, and biological properties were subsequently determined. The results demonstrated that the cyclodextrin-based hydrogels had a porous structure, high swelling ratio, good injectability, drug release ability, and antioxidant activity. Cell culture results illustrated that the hydrogels had no significant cytotoxicity toward L929 fibroblast cells. Considering all properties, the ?-CD-PEG-600-Ec hydrogel showed the most satisfactory properties rather than other ones. The potential of this hydrogel in preventing Asherman’s syndrome was evaluated in a rat model. The results revealed that the ?-estradiol- and melatonin-loaded cyclodextrin-based multifunctional hydrogel group both structurally and mechanically showed an antiadhesion effect in the uterus and a therapeutic effect on the damage with the ?-estradiol and melatonin that it contains compared to the Asherman (ASH) group. This double drug-loaded hydrogel can be a promising candidate for preventing Asherman’s syndrome due to its versatile properties. © 2024 The Authors. Published by American Chemical Society.
