Yazar "Asma, Dilek" seçeneğine göre listele
Listeleniyor 1 - 13 / 13
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Antioxidative and metabolic responses to extended cold exposure in rats(Akademiai Kiado Zrt, 2008) Yuksel, Sengul; Asma, Dilek; Yesilada, OzferIn this work, we investigated whether extended cold exposure increases oxidative damage and susceptibility to oxidants of rat liver, heart, kidney and lung which are metabolically active tissues. Moreover in this study the effect of cold stress on some of the lipid metabolic mediators were studied in rat experimental model. Male albino Sprague-Dawley rats were randomly divided into two groups: The control group (n = 12) and the cold-stress group (n = 12). Tissue superoxide dismutase (SOD), catalase (CAT), glutathion S-transferase (GST) and glutathion reductase (GR) activities and glutathion (GSH) were measured using standard protocols. The biochemical analyses for total lipid, cholesterol, trigliceride, HDL, VLDL and LDL were done on autoanalyzer. In cold-stress groups SOD activity was decreased in the lung whereas it increased in the heart and kidney. CAT activity was significantly decreased (except liver) in all the tissues in treated rats. GST activity of cold-induced rats increased in liver and heart while decreased in the lung. GR activity was significantly decreased (except in liver) in all the tissues in cold-stressed rats. GSH level was significantly increased in the heart but decreased in the lung of animals exposed to cold when compared to controls. It was found that among the groups trigliceride, total lipid, HDL and VLDL parameters varied significantly but cholesterol and LDL had no significant variance. In this study, we found that exposure of extended (48 h) cold (8 C) caused changes both in the antioxidant defense system (as tissue and enzyme specific) and serum lipoprotein profiles in rats.Öğe Bazı fungus ve bakterilerde detoksifikasyon sistemi ve sistem üzerine pestisitlerin etkisinin araştırılması(İnönü Üniversitesi, 1998) Asma, DilekÖZET Bu çalışmada Basidiomycetes sınıfına dahil olan Funalia trogii ve Ascomycetes sınıfından Aspergillus niger kullanılmıştır. Araştırmada ayrıca Escherchia coli, Pseudomonas aeruginosa, Pseudomanas putida ve Staphylococcus aureus bakterileri ile de çalışılmıştır. Çalışmada mikroorganizmaların detoksifikasyon sistemi ile ilgili oldukları düşünülen katalaz (CAT), glutatyon redüktaz (GR), glutatyon S- transferaz (GST) süperoksit dismutaz (SOD) ve redükte glutatyon seviyelerinin zamana bağlı değişimleri araştırılmıştır. Ayrıca bu sistem üzerine çeşitli pestisitlerin etkisi de test edilmiştir. Statik ve çalkalamak koşullarda üretilen F. Trogii'nin CAT ve GR aktiviteleri kontrol grubunda üremenin erken fazlarında yüksek iken geç fazlara doğru düşmüştür. GST ve SOD aktiviteleri ile GSH miktarında ise artış saptanmıştır. Çalkalamak koşullarda üretilen F. trogii 'ye insektisit uygulanması katalaz aktivitesini geç fazlara doğru indüklerken, statik koşullarda insektisit uygulanması katalaz aktivitesini üremenin geç fazlarında azaltmıştır. İnsektisit eklenmesi sonucunda her iki koşulda da, statik ve çalkalamak, genelde GR, GST ve SOD enzim aktivitelerinde ve GSH miktarında azalma saptanmıştır. A. niger ile çalkalamak koşullarda insektisit eklenmeyen besiyerinde yürütülen çalışmada katalaz aktivitesi üremenin başlangıcında artmış ancak 4. ve 5. günlerde ise azalmıştır. GST ve GR aktiviteleri de zamana bağlı olarak azalırken, GSH miktarının ise üremenin erken fazlarında düşük olup, 5. günde arrtığı saptanmıştır. SOD aktivitesi ise fazla bir değişim göstermeyip üremenin geç safhalarında artmıştır. İnsektisit uygulaması ise GR aktivitesini azaltırken üremenin 2. ve 5. gününde GST aktivitesini, 4. ve 5. günlerde katalaz aktivitesini, 1. ve 2. günlerde ise SOD aktivitesini artırmıştır. Çalışmada ayrıca bir herbisit olan paraquat'ın F. Trogii'de bu enzimler ve glutatyon üzerine etkisi de test edilmiştir. Üretimin başlangıcında 0.1 ve 1,0 mM paraquat uygulamaları CAT aktivitesini ve GSH miktarım azaltırken, SOD, GR ve GST aktivitelerini ise artırmıştır. Üretim sonrası paraquat uygulaması ise CAT aktivitesini azaltmışta. 0.1 mM'lık uygulama, GR aktivitesini artırmış, 1.0 ve 10.0 mM'lık uygulamalar ise aktiviteyi azaltmıştır. GST aktivitesi ise 6. günde herbisit eklenmesi sonucunda artmıştır. Her üç konsantrasyonda da GSH miktarı azalırken SOD aktivitesi artmıştır. Genel olarak F. trogii ye paraquat uygulamaları SOD aktivitesinin artışına ve CAT aktivitesinin düşmesine neden olmuştur. Bu paraquat uygulaması sonucunda hidrojen peroksit birikimine bağlı olarak diğer organizmalarda da olumsuz etki ortaya çıkabileceğini göstermektedir. Bu yüzden paraquatin dikkatli kullanılması gereklidir. Çalışmamızda ayrıca çeşitli bakterilerin detoksifikasyondan sorumlu enzim aktiviteleri ve redükte glutatyon miktarındaki değişimler de araştırılmıştır. E. coli, P. Putida ve S. aureus' da CAT ve GR aktivitelerinin zamana bağlı dalgalanmalar gösterdiği gözlenmiştir. GST, SOD aktiviteleri ve GSH miktarı ise zamana bağlı olarak azalmıştır. Bu açıdan F. trogii ve bakteriler farklılık göstermektedirler. Bu çalışmada son olarak P. aeruginosa üzerine üremenin başlangıcında ve üreme sonrası iki farklı şekilde eklenen insektisitin etkisi araştırılmıştır. P. aeruginosa 'nın besiyerine üretimin başlangıcında eklenen 5 ve 20 ppm insektisit katalaz aktivitesini azaltırken GR aktivitesini artırmıştır. SOD aktivitesi ise m 4. saatte baskılanırken daha sonraki saatlerde indüklenmiştir. GST aktivitesi genel olarak azalırken, GSH miktarı bu azalmanın tersine artmıştır. Üretimin 8. saatında eklenen 5 ve 20 ppm insektisit, katalaz aktivitesini 30 dakikada artırırken 0, 60 ve 120. dakikalarda düşürmüştür. GR aktivitesi 30. dakikada artmış ancak 0 ve 120. dakikalarda baskılandığı gözlenmiştir. GST aktivitesi 5 ppm'lik uygulamalar sonucunda 0 ve 30. dakikalarda azalmıştır. Yüksek doz uygulama sonucunda (20 ppm) ise 60 ve 120. dakikalarda aktivite artmıştır. Bunların yanısıra GSH miktarı azalırken SOD aktivitesi artmıştır. Sonuç olarak mikroorganizmaların detoksifikasyon sisteminde yer alan bu ajanların zamana bağlı değişimi mikroorganizmadan mikroorganizmaya farklılık göstermektedir. Yine pestisit uygulamalarının etkisi de kullanılan mikroorganizmaya ve üreme fazına bağlı olarak farklılık içermektedir. Çalışmada mikroorganaizmaların detoksifikasyon sistemi ilk kez bu kadar geniş araştırılmış ve ilk kez zamana bağlı değişim ortaya konmaya çalışılmıştır. Anahtar Kelimeler: Süperoksit dismutaz, Katalaz, Glutatyon redüktaz, Glutatyon S- transferaz, Glutatyon, Fungus, Bakteri, Pestisid.Öğe Çeşitli pestisitlerin gammarus kischineffensis'in antioxidan enzim sistemi ve bazı biyobelirteçler üzerine etkisi(2012) Asma, Dilek; Öğüt, Serdal; Güven, Kemal[Abstract Not Available]Öğe DEVELOPMENT OF VOLTAMMETRIC MELANIN SENSOR WITH 2,5-DIMETHYLFURAN MODIFIED PLATINUM ELECTRODE(Soc Chemists Technologists Madeconia, 2021) Burc, Muammer; Asma, Dilek; Duran, Serap TitretirIn this study, an electrochemical sensor was developed for the electrochemical determination of melanin. For this purpose, phosphate buffer salt (PBS, pH 7.00) solution was used as an electrolyte, 2,5dimethylfuran (2,5-DMF) as a monomer, Pt wire as the auxilary electrode, Ag/AgCl electrode as the reference electrode and a platinum electrode as the working electrode. The modification of the electrode was performed by polymerization of 2,5-DMF at the bare Pt electrode surface using the cyclic voltammetry method. Parameters such as film thickness, scan rate and pulse amplitude with prepared 2,5-DMF modified platinum electrode (p(2,5-DMF)/PtE) were optimized by square wave voltammetry (SWV) in PBS buffer containing melanin. In optimum conditions, the anodic peak height showed a linear increase with the melanin concentration. The limit of detection (LOD) and limit of quantitation (LOQ) were calculated to be 0.088 mmol/l and 0.292 mmol/l, respectively, with melanin concentrations ranging from 0.10 to 2.20 mmol/l and the correlation coefficient (R2) was calculated as 0.9985. Stability of the prepared sensor was found to be 99.63% by using the reproducibility experiments (n = 15).Öğe THE EFFECT OF RADIATION ON ANTIOXIDANT SYSTEM OF ESCHERICHIA COLI AND RADIATION RESISTANT DEINOCOCCUS RADIODURANS(Parlar Scientific Publications (P S P), 2019) Ozbey, Elif; Asma, DilekIn last 30-35 years, it has been discovered that many organisms can live in environments considered as extreme for mankind. Since these microorganisms can live in the extreme environments, they are named as extremophiles. One of the discovered microorganisms, Deinococcus radiodurans, had drawn attention for its extraordinary capabilities and its potential of infinity. D. radiodurans is resistant to genotoxic chemicals, oxidative damage, high-level ionization, ultraviolet radiation and dehydration. Because of these features one can name it polyextremophilic. In recent years, studies on bioremediation and related to heavy metal and detoxification of xenobiotics which cause serious environment problems, as well as genetic engineering, have been intense. However, the reactive oxygen species, induced by UV and their effects, their cellular defense mechanisms against ROS and about antioxidative systems responsible for cleaning of reactive oxygen species enough research has not been made.To this end; in Ecsherichia coli and radiation-resistant D. radiodurans bacteria were compared and tested effects on levels reduced glutathione (GSH) and antioxidant system of radiation. In both bacteria, enzyme activity and GSH levels has been determined after the different doses of gamma radiation applications. In the end of our study, high activities in enzyme especially superoxide dismutase and catalase of D. radiodurans were observed depending on the different doses gamma radiation applications. We were also observed that GSH quantity and other enzymes had a low activity in the cell. Moreover, it was determined that enzyme and GSH levels were decreased in E. coli depending on the radiation levels.Öğe Effects of endosulfan, thiamethoxam, and indoxacarb in combination with atrazine on multi-biomarkers in Gammarus kischineffensis(Academic Press Inc Elsevier Science, 2018) Demirci, Ozlem; Guven, Kemal; Asma, Dilek; Ogut, Serdal; Ugurlu, PelinStudies addressing the toxicity of pesticides towards non-target organisms focus on the median lethal concentration and biochemical response of individual pesticides. However, when determining environmental risks, it is important to test the combined effects of pesticides, such as insecticides and herbicides, which are frequently used together in agricultural areas. Here we aimed to investigate the toxic effects of the combined use of the herbicide atrazine and the insecticides, endosulfan, indoxacarb, and thiamethoxam on Gammarus kischineffensis. To do this, we tested the activities of oxidative stress, detoxification, and neurotoxicity biomarkers. Compared to atrazine alone, we detected higher glutathione-S-transferase, catalase and superoxide dismutase activities (oxidative stress biomarkers) when atrazine was combined with either endosulfan or indoxacarb. However, higher IBR values were determined in organisms where pesticide mixtures were used according to individual use. Based on these results, mixtures of atrazine and other pesticides may cause synergistic effects and may be evidence of increased toxicity and oxidative stress.Öğe THE EFFECTS OF EXOGENOUS ADRENOMEDULLIN AND L-NAME ON ANTIOXIDANT DEFENCE SYSTEM OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS AND LIPID PARAMETERS OF SERUM IN RAT(Parlar Scientific Publications (P S P), 2011) Asma, Dilek; Yuksel, SengulThe aim of our study was to investigate the contribution of exogenous adrenomedullin (ADM): an antioxidant, and N sup omega nitro-L-arginine methyl ester (L-NAME); the nitric oxide synthase (NOS) enzyme inhibitor, to balance the oxidant/antioxidant status in hypothalamus and adrenal medulla, which are both key components of the hypothalamic-pituitary-adrenal (HPA) axis and affects some lipid metabolic mediators. Thirty six male albino Spraque-Dawley rats were randomly divided into three groups: the control group, the ADM group (8 nmol/kg, i.p.), and the L-NAME group (2 ml/kg, i.p.). Measurements of tissue superoxide dismutase (SOD), catalase (CAT), glutathion S-transferase (GST) and glutathion reductase (GR) activities and glutathione (GSH) were performed in tissues using chemical protocols. The biochemical analyses for total lipid, cholesterol, triglycerides, HDL, VLDL, and LDL were conducted on an auto-analyser. Administering exogenous ADM and L-NAME caused synergic changes in the tissues, antioxidative enzyme activities, and altered serum lipoprotein profiles in rats. In the adrenal medulla and hypothalamus of the experimental groups, SOD and GST activities decreased significantly, while the CAT and GR activities increased. The amount of GSH was enhanced in the both tissues in the ADM group only, while the amount was decreased for the hypothalamus of the L-NAME group. After the treatment, the cholesterol (of L-NAME group), triglyceride, total lipid, and VLDL parameters varied significantly, but there was no significant difference between the HDL and LDL among the groups.Öğe The evaluation of pre-grown mycelial pellets in decolorization of textile dyes during repeated batch process(Springer, 2010) Yesilada, Ozfer; Yildirim, Seval Cing; Birhanli, Emre; Apohan, Elif; Asma, Dilek; Kuru, FilizThis study was undertaken for the possibility of application of pre-grown pellets for biotechnological treatment of dyes and textile industry waste waters. Mycelial pellets of five different white rot fungi were tested for their dye decolorization activity. The pellets of Funalia trogii, Phanerochaete chrysosporium and Trametes versicolor were determined as the most effective ones. The decolorization ability of viable pellets was compared with the decolorization (adsorption) ability of dead pellets during repeated batch studies. Astrazon Black dye was decolorized effectively, about 90%, by viable pellets of all fungi during the first use. Viable F. trogii pellets were found as the most effective pellets. Upon pellet treatment not only a high decolorization but also reduced toxicity (antimicrobial activity) of the Astrazon Black dye was recorded. This type of decolorization activity with commercial or crude laccase was partially observed. Growing cells of F. trogii in batch system showed lower efficiency in color removal of mixed dyes compared to the pre-grown pellets in repeated batch system. The results in this study showed that mycelial pellets could effectively be used as an alternative to traditional physicochemical processes.Öğe Helical microtubules of nanostructured cobalt oxide for electrochemical energy storage applications(Biointerface Research Applied Chemistry, 2016) Atalay, Funda Ersoy; Kaya, Harun; Asma, Dilek; Bingol, AlperIn this study, Co3O4 nanostructured porous microtubes were prepared via chemical precipitation onto Aquaspirillum bengal bacteria in an aqueous solution. The morphological properties of the synthesized material were studied using a scanning electron microscopy (SEM). The diameter of the Co3O4 micro tubes is approximately 0.8 mu m, and the length is 4 mu m. The Brunauer-Emmett-Teller (BET) surface area was determined to be 87.07 m2/g. The nitrogen adsorption and desorption isotherm displayed properties associated with a typical type IV isotherm. The electrochemical properties of the produced material were studied using cyclic voltammetry (CV), long-term charge/discharge analysis and impedance spectroscopy (EIS).Öğe In UV-C, Deinonoccus radiodurans and Vitreoscilla Hemoglobin (vgb) Gene Transferred Recombinants; Effect on SOD, KAT and Carotene Amount(Kahramanmaras Sutcu Imam Univ Rektorlugu, 2022) Ozbey, Elif; Asma, DilekUltraviolet radiation (UV); creates oxidative stress by causing the formation of reactive oxygen species in biological tissues. Reactive oxygen species induced by UV. their effects and cellular defense mechanisms against them, and antioxidant systems responsible for cleaning reactive oxygen species are the subjects of much research today. In this study, Deinococcus radiodrans which is well known an extremophile for its resistance to many agents and conditions such as high levels of ionizing radiation and UV radiation, drought and chemicals that damage DNA and Vitreoscilla hemoglobin (vgb) gene cloned recombinant with. and vgb recombinant strain as a control were used. The effect of UV-C on the antioxidant defense systems of D. radiodurans (superoxide dismutase, catalase and carotene) was investigated, and in addition, the contribution of the vgb(-) gene, which provides more oxygenated environment to the organism, to the UV resistance of the bacteria, was investigated. Accordingly, when UV-C treated samples of D. radiodurans (vgb(-)) were compared with the control groups, it was determined that the superoxide dismutase and catalase enzyme activities were lower than the wild and the recombinant. carrying the vgb gene. Again, in wild-type bacteria with high carotene. an increase in the amount of carotene was clearly observed due to UV-C application.Öğe Krom’un Deinococcus radiodurans ve Rekombinantlarına Etkisi(2019) Özbey, Elif; Asma, DilekÖz: Ağır metaller düşük konsantrasyonlarda bulunmaları durumunda bile canlı organizmalar için toksiketkiye sahip olabilirler. Canlı metabolizmasında önemli bir yeri olan krom, genellikle Cr (III) formundabulunmaktadır. Cr (VI) ise endüstriyel faaliyetler sonucunda ortaya çıkmaktadır. Son yıllarda ciddi çevreproblemlerine neden olan ağır metallerin ve ksenobiyotiklerin detoksifikasyonuyla ilgili yoğun araştırmalaryapılmaktadır. Özellikle bu maddeleri daha zararsız bileşiklere çevirmek için gerekli olan genetik bilgiye sahipbakteri türlerinin alternatif kullanım alanı bulabileceği anlaşılmıştır. Bu amaçla çalışmamızda, yabanılDeinococcus radiodrans ile Vitreoscilla hemoglobin (vgb) geni klonlanmış rekombinantı ve kontrol olarak davgb¯ rekombinant suşu kullanılmıştır. Bu sayede D. radiodurans ve rekombinantlarının üreme potansiyelleriüzerine Cr?un etkisi araştırılarak bakterilerin metal uygulaması öncesi ve sonrası morfolojik değişimleri SEMfotoğrafları ile saptanmıştır. Bunlara ek olarak bakteriye daha fazla oksijenli ortam sağlayan vgb geninin,bakterinin üreme yeteneğine yapacağı katkı araştırılmıştır. Çalışmamızın sonunda, bakterilerin üremepotansiyelleri üzerinde vgb geninin bakteriye daha fazla oksijenli ortam yaratıp daha fazla üremesini sağlayarakmeydana getirdiği olumlu etkiler gözlenmiştir.Öğe RESPONSE OF ANTIOXIDANT DEFENCE SYSTEM TO CADMIUM-INDUCED TOXICITY IN WHITE ROT FUNGUS Phanerochaete chrysosporium(Parlar Scientific Publications (P S P), 2010) Yildirim, Numan; Asma, DilekThe effect of different cadmium (Cd) concentrations (5 mu M and 500 mu M) on antioxidant enzymes including superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), glutathione reductase (OR, EC 1.8.1.7) and glutathione S-transferase (GST, EC 2.5.1.18), and glutathione levels was studied in white rot fungus Phanerochaete chrysosporium (ME446), grown in liquid medium. Exposure to 500 mu M Cd resulted in significant induction of SOD actvity. Exposure to high (500 mu M) and low concentration (5 mu M) led to a clear induction of CAT activity with respect to control group. Exposure to 5 mu M Cd increased GR activity. GST activity was induced but GSH level reduced by exposure to 5 mu M Cd.Öğe Synthesis of NiO Nanostructures Using Cladosporium cladosporioides Fungi for Energy Storage Applications(Sage Publications Ltd, 2016) Atalay, Funda Ersoy; Asma, Dilek; Kaya, Harun; Bingol, Alper; Yaya, PinarIn this work, we produced nickel oxide nanostructures that show high electrochemical capacitive behaviour, using fungus - one of the most common life forms in nature. Cladosporium cladosporioides fungi are particularly attractive biotemplates due to their tubular structures. The nanostructured porous microtubes were prepared by chemical precipitation onto fungi. The morphological properties of the biosynthesized NiO microtubes were studied by transmission electron microscope (TEM). The Brunauer-Emmett-Teller (BET) surface area was found to be 119.72 m(2) g(-1) with an average pore size distribution of 7.5 nm. A maximum capacitance value of 334 F g(-1) was observed at 0.8 A g(-1), and a capacitance retention of approximately 95% was obtained after 1000 cycles.
