Nuray N Ulusu

Koc University · Medical Biochemistry

Gemcitabine (GEM) is a first-line treatment for pancreatic ductal adenocarcinoma (PDAC) patients, causing side effects and poor overall survival. Eighty percent of patients often develop resistance rapidly to GEM. Developing therapeutic approaches and increasing sensitivity to gemcitabine in PDAC has become one of the challenges in cancer research....

Objectives The elderly population is categorized as a risk group for COVID-19 infection, and dementia is the primary cause of disability in elderly individuals and affects 70 % of the elderly population. In this study, we evaluated the blood and serum biomarkers of deceased dementia patients infected by COVID-19 compared to the survived dementia an...

Extracellular vesicles (EVs) are membrane-encapsulated vesicles carrying various signal molecules, including metabolites, proteins, enzymes, genetic material, nucleic acids, mRNAs, noncoding RNAs, intact RNAs, lipids, organelles, ions, pathogenic microorganisms, and disease-specific molecules. The International Society for Extracellular Vesicles (I...

Purpose of Review The global COVID-19 pandemic has become a major public health problem since December 2019, affecting millions of people, especially individuals with comorbidities including cancer, diabetes, hypertension, cardiovascular disease, obesity, and hematological disorders. People are still infected and die despite vaccination since the v...

Phthalates are widely used as plasticizers in the industry and are found in cosmetics, food and drink packaging, drugs, toys, households, medical devices, pesticides, personal care products, and paints. Phthalates exert endocrine disrupting and peroxisome proliferator effects in humans and wildlife associated with the pathogenesis of various diseas...

Innovative medical education greatly relies on lifelong learning with universal standards in research, for generating novel knowledge for improvement maximum patient care. The other side of innovative medical education relies on success of development of novel ideas, perspective; skill building, future career objectives. Leaders have curious roles...

A high fructose diet is a major cause of diabetes and various metabolic disorders, including fatty liver. In this study, we investigated the effects of resveratrol and vitamin D (VitD) treatments on endoplasmic reticulum (ER) stress, oxidative stress, inflammation, apoptosis, and liver regeneration in a rat model of type 2 diabetes mellitus, namely...

Radiofrequency radiation (RFR) as an environmental and physical pollutant may induce vulnerability to toxicity and disturb fetal development. Therefore, the potential health effects of short-term mobile phone like RFR exposure (GSM 1800 MHz; 14 V/m, 2 mW/kg specific absorption rate (SAR) during 15 min/day for a week) during pregnancy and also the d...

Endocrine-disrupting chemicals (EDCs) are xenobiotics found in almost all types of industrial products such as toys, pharmaceuticals, cosmetics, food wrappings, furniture, paints, solvents, plasticizer, and households. Phthalates are the most used chemicals in the industry belonging to the EDCs family. Di(2-ethylhexyl) phthalate (DEHP), di-isononyl...

The rate of workplace-related various diseases will have arisen. Electrical workers, particularly, might be exposed to different physical, chemical, and biological agents. The respiratory system will be more vulnerable to the initiated inflammatory responses with the combined effects of these dangerous agents. The present study investigated E field...

COVID-19 pandemic has become a major public health problem affecting the lives of billions of people worldwide including Africa. Since there is no effective vaccine or treatment, self-isolation and self-protection are the only options to stop the spread of the virus. Usage of the surgical and other face masks are must during COVID-19 pandemic and m...

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease, and ALS incidence is increasing worldwide. Patients with ALS have respiratory failure at the disease’s end stages, leading to death; thus, the lung is one of the most affected organs during disease progression. Tissue stiffness increases in various lung diseases because of...

Book cover Basic Protocols in Foods and Nutrition pp 145–168Cite as Evaluation of the Minerals and Trace Elements in the Biological Samples Duygu Aydemir & Nuriye Nuray Ulusu Chapter First Online: 08 June 2022 Part of the Methods and Protocols in Food Science book series (MPFS) Abstract Minerals and trace elements are crucial for all organism...

Glutathione-related enzymes belong to the protection mechanism of the cells against harmful oxidative damage and chemicals. Glutathione S-transferase (GST) is frequently over-expressed in various cancer cells and is involved in drug resistance. Chlorophyllin is an antioxidant molecule interfering with the GST P1-1 activity. The purpose of this stud...

Aim Elderly population is categorized as a risk group for COVID-19 infection and dementia is the major cause of disability in elderly individuals and affects 70% of the elderly population. In this study, we evaluated blood and serum biomarkers of the patients with dementia infected by COVID-19 to evaluate possible indicators of the severity of COVI...

Background Type 2 Diabetes Mellitus is a chronic metabolic disease that causes endothelial damage and is an important risk factor for atherosclerosis. In the present study vitamin D3 supplementation in rats was used to determine the role of Osteoprotegerin (OPG)/Receptor activator kB ligand (RANKL) signalling in endothelial damage and changes in th...

PDMS is the most widely used material in the microfluidic systems because of its advantageous properties including ease of manufacture, low cost, transparency, and gas permeability. Although all biomaterials need to be sterilized for usage for in vitro or in vivo systems to avoid possible contaminants, none of them proved effective in providing the...

Aortic stiffness represents the major cause of aging and tightly associated with hypertension, atherosclerosis, cardiovascular diseases, and increased mortality. Mechanical characteristics of the aorta play a vital role in the blood flow, circulation, systolic pressure, and aortic stiffness; however, the correlation of trace element and mineral lev...

Influence of the life style parameters including dietary habit, chronic stress and environmental factors and jobs on the human health in relation to COVID-19 pandemic - Duygu Aydemir, Nuriye Nuray Ulusu

COVID‐19 threatens millions of lives especially elderly population and people with chronic diseases including diabetes, hypertension, cancer and cardiovascular diseases. Rapid and effective diagnosis are vital for the isolation of infected people and starting treatment immediately to stop the spread of COVID‐19 virus. Bioinformatics techniques such...

Amyotrophic lateral sclerosis (ALS) is a fatal neurological disorder affected by both genetic and environmental factors. Since ALS is a heterogenic disease, symptoms vary among patients and there are no prognostic biomarkers, 18 months of delay occur from the onset of symptoms to confirmation of the diagnosis. Additionally, there are only two FDA-a...

Objectives. Psychoactive drugs are a group of compounds used to treat severe mental problems, including psychosis, as well as other conditions. This study assessed clinically relevant side effects of haloperidol and clozapine on the thyroid hormones. Methods. Haloperidol (0.05 and 2 mg/kg) or clozapine (0.5 and 20 mg/kg) injected to male Wistar ra...

Minerals and trace elements play vital role in the biological functions for all organisms including human and other mammals. Therefore, imbalance in the mineral and/or trace element levels may cause formation of several diseases including cancer, diabetes, cardiovascular diseases, and neurological disorders. ICP-MS (inductively coupled plasma - mas...

Nanoflowers are recently developed flower-shaped nanoparticles consisting of several layers of petals to improve surface reaction and stability. Among them organic-inorganic hybrid nanoflowers have been spotlighted, since they can overcome enzyme-related limitations, including low stability, high production cost, substrate/product inhibition and di...

Background Metabolic syndrome, obesity and type 2 diabetes are metabolic disorders characterized by the insulin resistance and the impairment in the insulin secretion. Since impairment in the oxidative stress and adipocyte metabolism contribute to the formation of obesity and diabetes, targeting adipose tissue can be considered as an effective appr...

Di (2-ethylhexyl) phthalate (DEHP) is used as plasticizer in the industry and belongs to the phthalate family which can induce tissue damage including kidney, liver, and testis as a result of elevated oxidative stress levels. Glutathione reductase (GR), Glucose-6-phosphate dehydrogenase (G6PD), glutathione S-transferase (GST), 6-phosphogluconate de...

The scientific method can be described as a multistep and detailed process, in which finding the best question is the first and most crucial step. Thus, scientific problem should be examined thoroughly in different ways and perspectives. The amount and diversity of scientific data are enormously increasing and becoming more specific day by day, the...

Quantum dots (QD) are being evaluated as inorganic nanoparticles for both in vitro and in vivo optical imaging. They are also used as sensors or vehicles for targeted drug delivery combined with optical imaging. In this study, we demonstrated that glutathione coated Ag2S QDs (GSH‐Ag2S QDs) act as a substrate analogue of glutathione‐s transferase (G...

Di(2-ethylhexyl) phthalate (DEHP) is a widely used synthetic polymer in the industry. DEHP may induce reproductive and developmental toxicity, obesity, carcinogenesis and cause abnormal endocrine function in both human and wildlife. The aim of this study was to investigate trace element and mineral levels in relation of kidney and liver damage in D...

Background: The study aimed to investigate whether timolol-treatment has a beneficial effect on pentose phosphate pathway enzyme activities such as glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGDH) enzyme activities and cAMP level in streptozotocin-induced diabetic rats in pancreatic tissues Methods: Diabetes was in...

Glutathione (GSH), a key player in various cellular processes including detoxification, anti-oxidant defense system and cell proliferation is also a potentially good coating material for luminescent quantum dots. GSH is oxidized to oxidized glutathione (GSSG) under oxidative stress and then reduced back by glutathione reductase (GR) enzyme to maint...

Cardiovascular disease (CVD) is the leading cause of death in chronic kidney disease (CKD). One of the most important pathophysiological mechanisms for CVD in patients with CKD is the widespread and possibly accelerated formation of atherosclerotic plaques due to hyperlipidemia, uremic toxins, inflammation, oxidative stress, and endothelial dysfunc...

The pentose phosphate pathway and glutathione-associated metabolism are the main antioxidant cellular defense systems. This study investigated the effects of the powerful antioxidant SMe1EC2 (2-ethoxycarbonyl-8-methoxy-2,3,4,4a,5,9b-hexahydro-1H-pyrido[4,3-b] indolinium dichloride) on pentose phosphate pathway (PPP) and glutathione-dependent enzyme...

Aim of the present study is to investigate the effects of medication with donepezil (acetylcholinesterase inhibitor) on the liver and kidney function in Alzheimer's disease (AD) and to compare the effects of donepezil medication during short (one month) and long term (six years) follow-ups. We evaluated female and male patients from Cukurova [42 AD...

Physical transfer of viable tumor cells from one organism to another is known as transmissible cancer, which is observed in dogs, Tasmanian devils, Syrian hamsters, and some soft-shell clams. Tasmanian devil facial tumor disease is transmitted like an infectious disease between individuals through biting and other close contact. This extinction typ...

Background A large number of psychotropic drugs can interfere with the thyroid physiology, function and autoimmunity. Objective The aim of the present study was to investigate the effects of alprazolam and haloperidol on thyroglobulin, antithyroglobulin (aTg), antithyroid peroxidase, and thyroid stimulating hormone levels on rats. Materials and M...

Alzheimer’s disease (AD) is a multi-factorial neurodegenerative disorder that numerous factors have key properties in the development of this proteopathy. Glucose-6-phosphate dehydrogenase (G6PD) is the most common form of enzymopathy. We have examined G6PD enzyme activity levels in the serum of newly diagnosed AD patients compared with control sub...

Alzheimer’s disease (AD) is a severe multifactorial neurodegenerative proteopathy associated with advanced age. Discrepancies in the renal function of these patients compared to geriatric patients with dementia have rarely been reported. In this study, we aimed to disclose the importance of associated renal changes for the pathogenesis of AD. Patie...

Biotin, a water-soluble vitamin, is used as a co-factor by enzymes involved in carboxylation reactions. Biotinidase (BTD) catalyzes the recycling of biotin from endogenous and dietary sources. Biotinidase deficiency (BD) is an autosomal recessively inherited disorder of biotin recycling that is associated with neurologic and cutaneous consequences...

This study investigated the effects of flaxseed (Linum usitatissimum L.) intake on general metabolism, pentose phosphate pathway (PPP) and glutathione-dependent enzymes in diabetic rats. Diabetes was induced by streptozotocin injection (40 mg/kg, i.p.) and the enzyme activities were determined spectrophotometrically. Diabetic and control rats were...

Alzheimer's disease is a very severe degenerative disease that affects brain function. Neuronal loss, accumulation of extracellular amyloid β containing plaques and accumulation of intracellular (tau) neurofibrillary tangles are the hallmarks of this disease. We aim to investigate serum thyroid function tests in Alzheimer's disease, in addition to...

This review paper discusses the reciprocal kinetic behaviours of enzymes and the evolution of structure-function dichotomy. Kinetic mechanisms have evolved in response to alterations in ecological and metabolic conditions. The kinetic mechanisms of single-substrate mono-substrate enzyme reactions are easier to understand and much simpler than those...

Background/aim: Alzheimer disease, a common proteopathy of advanced age, is characterized by cortical atrophy, neuron degeneration, neuronal loss, and accumulation of extracellular amyloid β plaques. We aimed to investigate serum vitamin B12 and folic acid levels in Alzheimer disease and other dementia patients, as a potential screening test to de...

The factors with increasing diabetes-prevalence lead to significant global increases in chronic kidney disease. Since hyperglycemia generates more ROS and attenuates cellular antioxidant-defense mechanisms, numerous studies demonstrated that hyperglycemia-induced oxidative stress played a major role in the extracellular matrix expansion in tissues....

Life as we know it heavily relies on biological catalysis, in fact, in a very nonromantic version of it, life could be considered as a series of chemical reactions, regulated by the guarding principles of thermodynamics. In ancient times, a beating heart was a good sign of vitality, however, to me, it is actually the presence of active enzymes that...

Glutathione reductase (GR; E.C 1.6.4.2) catalyzes the reduction of oxidized glutathione to reduced glutathione by the nicotinamide adenine dinucleotide phosphate (NADPH) dependent mechanism. GR participates in the protection of the cell from the toxic effects of free radicals. In this study, we have investigated in vitro effects of isoorientin (C‐g...

Objective: Glucose-6-phosphate dehydrogenase is an important key enzyme which catalyzes the first oxidative step of the pentose phosphate pathway. The objectives of this study are to determine some properties and kinetic mechanism of glucose-6-phosphate dehydrogenase. Method: In this study we used the enzyme that was purified from sheep brain corte...

Glutathione reductase (GR, E.C 1.6.4.2) is a flavoprotein that catalyzes NADPH-dependent reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH). The aim of this study was to investigate in vitro effects of phenolic compounds isolated from Sideritis brevibracteata on bovine kidney GR. The Sideritis species are widely found in nature a...

Glutathione reductase (GR, NADPH:oxidized glutathione oxidoreductase, E.C 1.6.4.2) is a flavoprotein that catalyzes the NADPH-dependent reduction of oxidized glutathione (GSSG). GR is a crucial enzyme in the antioxidant system by maintaining reduced glutathione (GSH). Glucose 6-phosphate dehydrogenase (G6PD, glucose 6-phosphate (G6P):NADP(+) oxidor...

Effects of haloperidol and alprazolam on Tg,aTg,aTPO and TSH in rat

Effect of haloperidol and Alprazolam on Tg,aTg,aTPO and TSH hormone in rat

Hepatic ischemia reperfusion injury induced by Pringle maneuver leads to bacterial translocation, endotoxemia and apoptosis. Our aim was to compare the effects of low and high dose dexamethasone pretreatment on antioxidant enzyme activities, bacterial translocation, endotoxemia and apoptosis, following Pringle maneuver. Thirty-two rats were randomi...

Imatinib (Gleevec, STI571) is a drug used to treat certain types of cancer. Glucose-6-phosphate dehydrogenase and glutathione reductase are enzymes important for redox homeostasis and play key roles in many cellular processes. The purpose of the present work is to evaluate the in vitro effects of imatinib on sheep brain cortex glucose-6-phosphate d...

Heavy metal pollution can arise from many sources and damage many organisms. Exposure to the metal ions can leads to a reduction in cellular antioxidant enzyme activities and lowers cellular defense against oxidative stress. In this study we have tested effects of the some metal ions on the purified bovine kidney cortex glutathione reductase (GR)....

Colchicine is a drug used for the treatment of FMF, primary biliary cirrhosis, psoriasis, Behçet's disease, aphthous stomatitis. Glutathione reductase (GR; E.C 1.6.4.2) is a crucial enzyme which reduces glutathione disulphide to the sulfhydryl form GSH by the NADPH-dependent reduction, which is an important cellular antioxidant system. The purpose...

Glutathione reductase (GR; E.C. 1.6.4.2) is a flavoprotein that catalyzes the NADPH-dependent reduction of oxidized glutathione (GSSG). In this study we tested the effects of Al3+, Ba2+, Ca2+, Li+, Mn2+, Mo6+, Cd2+, Ni2+, and Zn2+ on purified bovine liver GR. In a range of 10 microM-10 mM concentrations, Al3+, Ba2+, Li+, Mn2+, and Mo6+, and Ca2+ at...

Current findings suggest a role for the angiotensin II (Ang II) signalling pathway in generation of reactive oxygen species and diabetes-induced cardiac complications. In this study we aimed to investigate the effect of angiotensin II type 1 (AT1) receptor blockage on some antioxidant enzymes such as glucose- 6-phosphate dehydrogenase (G6PD), 6-pho...

Glutathione reductase was purified 34806-fold with a final yield of 85 % from the bovine kidney cortex. Some molecular and kinetic properties of purified enzyme are investigated. Product inhibition studies showed that the enzyme obeys 'branched" mechanism: Km(NADPH) 18 +/- 3 microM and Km(GSSG) 65 +/- 5 microM were determined.

The metabolic response to adaptive conditions is very important for cell survival. Eukaryotic cell metabolism is exposed to different types of signals derived from the changing environment, therefore cell must be regulate its' metabolism according to the altering conditions. Recent findings demonstrate that mRNA metabolism is one of the regulatory...

Objectives: The aim of this study is to investigate thioredoxin reductase and glutathione peroxidase activities in malignant and benign lesions of breast. Methods: We have investigated thioredoxin reductase and glutathione peroxidase activities spectrophotometrically in 32 patients (breast cancer, fibroadenoma and fibrocystic disease) in malignant...

The present study was designed to determine whether there are beneficial effects of intake of Omega-3E (containing 70% pure omega-3 and 2% natural vitamin E) in cardiac dysfunction of diabetic rats. We also examined whether there are gender-related differences in the responses to the intake of Omega-3E on the heart dysfunction. Experiments were per...

Glutathione reductase (GR, NADPH: oxidized glutathione oxidoreductase, EC 1.6.4.2) catalyzes the reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH) using NADPH as reducing cofactor. The aim of the present work was to purify and characterize GR from bovine liver. GR was purified using 2', 5' ADP-Sepharose 4B and DEAE-Sepharose Fas...

Collagen has been studied extensively by a large number of research laboratories since the beginning of the 20th century. Collagens are the major fibrous glycoproteins present in the extracellular matrix and in connective tissue such as tendons, cartilage, the organic matrix of bone, and the cornea, and they maintain the strength of these tissues....

Glutathione reductase (GR, type IV, Baker's yeast, E.C 1.6.4.2) is a flavoprotein that catalyzes the NADPH-dependent reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH). In this study some metal ions have been tested on GR; lithium, manganese, molybdate, aluminium, barium, zinc, calcium, cadmium and nickel. Cadmium, nickel and cal...

Sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) and plasmalemmal Ca(2+)-ATPase (PMCA) activities in cremaster muscles and sacs, which have been subjected to different autonomic tonuses, were determined and compared. Samples of cremaster muscles and sacs associated with male or female inguinal hernia, hydrocele or undescended testis were obtained...

The aim of this study was to determine the most efficient purification protocol for purification of glucose-6-phosphate dehydrogenase (G6PD, EC 1.1.1.49) from sheep brain cortex. G6PD was purified by 2′,5′-ADP- Sepharose 4B affinity and DEAE Sepharose Fast Flow ion exchange chromatography columns in different orders. In all purification protocols,...

Radiation-induced acute intestinal injury after abdominal irradiation is a common and serious problem. The aim of this study was to evaluate the protective effect of Lactobacillus delbrueckii subsp bulgaricus B3 on the activities of antioxidant enzymes such as glutathione reductase, glucose-6-phoshate dehydrogenase (G-6-PD), 6-phosphogluconate dehy...

Ischaemia–reperfusion (I/R) injury, one of the main causes of acute renal failure, still needs satisfactory treatment for routine clinical application. Stobadine, a novel synthetic pyridoindole anti‐oxidant, has the ability to reduce tissue injury induced by mechanisms involving reactive oxygen species during I/R. The aim of the present study was t...

Ischemia-reperfusion (I/R) injury is one of the most common causes of renal dysfunction. Taurine is an endogenous antioxidant and a membrane-stabilizing, intracellular, free beta-amino acid. It has been demonstrated to have protective effects against I/R injuries to tissues other than kidney. The aim of this study was to determine whether taurine h...

Glutathione reductase (GR) is a crucial enzyme (EC 1.6.4.2) that reduces glutathione disulfide (GSSG) to the sulfhydryl form GSH by the NADPH-dependent mechanism, an important cellular antioxidant system. Due to its significance, the enzyme has been purified from a number of animals, plants and microbial sources and studied in an effort to identify...

Glucose-6-phosphate dehydrogenase (G-6-PD) is the first enzyme in the pentose phosphate pathway. Cadmium is a toxic heavy metal that inhibits several enzymes. Zinc is an essential metal but overdoses of zinc have toxic effects on enzyme activities. In this study G-6-PD from lamb kidney cortex was competitively inhibited by zinc both with respect to...

ABSTRACTCalcium ions are essentail for some of the cellular functions, including musclecontraction, adhesion, secretion, motility, growth, differentiation, gene expression,and cell death. The change in calcium concentration is transmitted as a signal ofthe intracellular second messenger. Calcium binding proteins are the mediators ofthe signal, and...

Glucose-6-phosphate dehydrogenase (G-6-PD) is one of the important enzymes, which is responsible for the production of NADPH and ribose-5-phosphate. NADPH is used for the biosynthetic reactions and protection of the cells from free radicals. We have investigated some properties and kinetic mechanism of the sheep kidney cortex G-6-PD. This enzyme ha...

It is known that selenium compounds can restore some metabolic parameters in experimental diabetes. However, as there are no clear data about their effects on the altered antioxidant defense system of the diabetic heart, we aimed to investigate whether these beneficial effects extend to the alterations of some enzyme activities, which play importan...

Glucose-6-phosphate dehydrogenase is the key regulatory enzyme of the pentose phosphate pathway and one of the products of this enzyme; NADPH has a critical role in the defence system against the free radicals. In this study, glucose-6-phosphate dehydrogenase from lamb kidney cortex kinetic properties is examined. The purification procedure is comp...

The aim of this study was to examine: the 24 h variation of 6-phosphogluconate dehydrogenase and glucose-6-phosphate dehydrogenase activities, key enzymes for the maintenance of intracellular NADPH concentration, in rat liver in control and streptozotocin-induced diabetic animals. Adult male rats were fed ad libitum and synchronized on a 12:12 h li...

We have shown that a single dose of streptozotocin (STZ) (50 mg/kg body weight) injected into rats caused significant changes in some antioxidant enzyme activities, such as glutathione peroxidase, glutathione reductase, glutathione-S-transferase, glucose-6-phosphate dehydrogenase, and 6-phosphogluconate dehydrogenase activities, and acid-soluble su...