Normal and Tumour Tissue mRNA Expressions of Telomerase Complex Genes in Several Types of Cancer.

Aims: To investigate the changes in mRNA expression levels of telomerase-related significant proteins in several types of cancer.

Methods: Human telomerase reverse transcriptase, pontin, reptin and dyskerin expressions were measured in normal and tumour tissues obtained from 26 patients with colorectal, breast and gastric cancers, using the real-time reverse transcriptase-polymerase chain reaction method.

Results: For all patients, no significant difference was found in mRNA expressions of human telomerase reverse transcriptase and dyskerin (p>0.

Relation of kynurenine/tryptophan with immune and inflammatory markers in coronary artery disease.

Background: Inflammation and immune activation have a crucial role in the pathogenesis of cardiovascular diseases. Indolamine 2,3-dioxygenase, a tryptophan catabolising enzyme, is up-regulated with various inflammatory stimuli. The aim of this study was to evaluate the relationship of tryptophan degradation with immune and inflammatory markers in coronary artery disease.

Accumulation of an endogenous inhibitor of nitric oxide synthesis and oxidative DNA damage in end-stage renal disease.

Background: Elevated oxidative status and reduced antioxidant defence systems in patients with chronic renal failure (CRF) accelerate the prevalence of atherosclerosis and other chronic complications. We aimed to investigate the levels of reactive oxygen, nitrogen species, and antioxidants in patients with end-stage renal disease (ESRD) having hemodialysis and controls and evaluate the factors that might influence the oxidative-antioxidative balance.

Methods: Sixty four patients with ESRD were enrolled in this study.

Serum homocysteine levels and sildenafil 50 mg response in young-adult male patients without vascular risk factors.

The aim of the present study was to investigate serum homocysteine levels in patients with erectile dysfunction and to evaluate the relationship between serum homocysteine levels and response to the standard 50 mg phosphodiesterase 5 inhibitor treatment. Twenty-eight erectile dysfunction patients having normal vascular parameter according to Penile Doppler Ultrasonography and twenty healthy subjects were enrolled in the study. All subjects filled The International Index of Erectile Function (IIEF) questionnaire.

Influence of gender on C-reactive protein, fibrinogen, and erythrocyte sedimentation rate in obstructive sleep apnea.

Inflammation is one of the pathophysiological pathways suggested for the development of cardiovascular disease in obstructive sleep apnea (OSA). The recurrent nocturnal episodes of hypoxia/reoxygenation observed in patients with OSA appear to be partly responsible for the systemic inflammatory response. The aim of this study was to investigate the role of inflammation by measuring the C-reactive protein (CRP) and fibrinogen levels, and erythrocyte sedimentation rate (ESR) in the OSA according to gender.

Increased oxidative DNA damage and impaired antioxidant defense system in patients with gastrointestinal cancer.

Background: Highly active intermediates are formed in aerobic metabolism which in turn leads to cellular damage. It is increasingly proposed that free radicals play a key role in human cancer development. The aim of this study was to investigate changes in 8-hydroxy-deoxyguanosine, nitrite+nitrate, total glutathione, total antioxidant capacity levels and superoxide dismutase, catalase, glutathione peroxidase activities in operative patients with gastrointestinal cancer before and after surgery and compare with inoperative patients.

Variability of total thiol compounds, oxidative and nitrosative stress in uncomplicated pregnant women and nonpregnant women.

Purpose: The objective of this study was to determine the changes in total plasma thiols (homocysteine, cysteine and cysteinylglycine), lipid peroxidation and nitric oxide concentrations during normal pregnancy.

Methods: These variables were measured in 28 uncomplicated pregnant women at first, second and third trimesters and in 19 nonpregnant women.

Results: The mean concentrations of homocysteine, cysteine and cysteinylglycine were significantly lower in all trimesters of pregnancy compared with nonpregnant controls.

Tryptophan degradation and neopterin levels in treated rheumatoid arthritis patients.

Increased kynurenine/tryptophan-reflects trytophan degradation-and neopterin levels have been regarded as a biochemical marker of cell-mediated immune response and inflammation. This study was designed to evaluate the usefulness of tryptophan degradation and neopterin levels in active rheumatoid arthritis patients under therapy. In this case-control study, kynurenine and tryptophan levels were determined by HPLC; neopterin and tumor necrosis factor-α levels were measured with ELISA in 32 active rheumatoid arthritis patients and 20 healthy controls.

Increased levels of 8-hydroxydeoxyguanosine and its relationship with lipid peroxidation and antioxidant vitamins in lung cancer.

Background: Reactive oxygen species produced either endogenously or exogenously can attack lipids, proteins and DNA in human cells and cause potentially deleterious consequences. In recent years, their role in the pathogenesis of lung cancer and the preventive effect of antioxidants have been studied extensively. In this study, our aim was to investigate the levels of 8-hydroxy-2'-deoxyguanosine (8OHdG) and malondialdehyde as a marker for the effects of reactive oxygen species on DNA and lipids, the levels of antioxidant vitamins and the correlations between these oxidative stress markers and antioxidants in lung cancer.

Circulating nitric oxide (NO), asymmetric dimethylarginine (ADMA), homocysteine, and oxidative status in obstructive sleep apnea-hypopnea syndrome (OSAHS).

Obstructive sleep apnea-hypopnea syndrome (OSAHS) with episodic hypoxia-reoxygenation is associated with increased cardiovascular morbidity and mortality. Therefore, increased homocysteine, asymmetric dimethylarginine (ADMA), oxidative status, and decreased nitric oxide levels have been implicated as possible mechanisms for development of cardiovascular diseases. We aimed to investigate changes in the levels of these substances in patients with OSAHS in comparison with nonapneic controls.

Usefulness of homocysteine as a cancer marker: total thiol compounds and folate levels in untreated lung cancer patients.

Background: Apart from being a risk factor for atherosclerotic cardiovascular diseases, the latest research suggests homocysteine as a marker for cancer. We aimed to explore the clinical utility of plasma homocysteine levels as a marker in lung cancer.

Patients And Methods: Changes in serum total thiols and folate levels were investigated in newly diagnosed untreated lung cancer patients (n = 37) and compared with healthy controls (n = 26).

Assessment of homocysteine, neopterin and nitric oxide levels in Behçet's disease.

Background: Behçet's disease is a multisystemic immunoinflammatory disease with a wide variety of clinical manifestations, whereas recurrent aphthous stomatitis is a local oral disease. The aim of this study was to examine the distribution of homocysteine levels in patients with active Behçet's disease, possible association of homocysteine with nitric oxide and neopterin levels, and to characterize the differences between patients with Behçet's disease and those with recurrent aphthous stomatitis in terms of these parameters compared with healthy controls.

Methods: A total of 23 patients with active Behçet's disease, 25 patients with recurrent aphthous stomatitis as positive controls, and 21 healthy subjects were included in this study.

Increased plasma homocysteine and allantoin levels in coronary artery disease: possible link between homocysteine and uric acid oxidation.

Objective: Homocysteine increases the damage to the cardiovascular system in different ways, one of them is the formation of reactive oxygen species resulting from the auto-oxidation of homocysteine. At the same time, uric acid is one of the major antioxidants in the plasma and protects the cells towards increased ROS activity. In humans, allantoin is only formed from non-enzymatic oxidation of uric acid by free radicals.

Oxidative stress is decreased in off-pump versus on-pump coronary artery surgery.

Oxidative stress occurs in patients undergoing coronary artery bypass operation. The aim of this study was to investigate the difference in oxidative stress in off-pump versus on-pump coronary artery bypass surgery. In the present study, in serial blood samples, plasma malondialdehyde (MDA) as index of lipid peroxidation, red blood cells glutathione peroxidase (GPx) and superoxide dismutase (SOD) were measured to compare the extent of oxidative stress in 30 patients undergoing OPCAB (off-pump coronary artery bypass grafting), 12 patients undergoing CABG (on-pump coronary artery bypass grafting) and 18 healthy controls.

The association between total antioxidant status and oxidative stress in Behçet's disease.

There has recently been growing evidence supporting the importance of oxidative stress in the pathogenesis of Behçet's disease (BD). In this study, we aim to evaluate total antioxidant status (TAS) and total oxidative stress (TOS) in BD patients, and compare their results both with controls that had recurrent aphthous stomatitis (RAS) and healthy controls. TAS statistically decreased in RAS patients, and TOS levels increased in BD and RAS patients than those in healthy controls.

Lipid peroxidation and antioxidant status in blood and tissue of malignant breast tumor and benign breast disease.

Changes in the levels of malondialdehyde (MDA), nitrate and nitrite (as an index of nitric oxide production), lipid hydroperoxide (LOH), total antioxidant capacity (TAC), lipids (total cholesterol and triglycerides) and lipoproteins (HDL- and LDL-cholesterol) were estimated in breast cancer patients (n = 15) and benign breast disease (n = 15). Serum and tissue MDA levels were found to be decreased in breast cancer patients compared to the benign group (p < 0.05).

Oxidative status in rheumatoid arthritis.

The insufficiency of antioxidant defense systems and the acceleration of the oxidative reactions can be results of the pro-oxidant/antioxidant imbalance in rheumatoid arthritis (RA). The aim of our study was to investigate the changes in oxidant status by measuring two different parameters; one was the level of malondialdehyde (MDA) as an index of lipid peroxidation and the other was total oxidative status; we could then compare our results with the antioxidant status, superoxide dismutase (SOD) enyzme activities. All were assessed in 22 patients with active RA and 18 age- and gender-matched control subjects.

Urate oxidation during percutaneous transluminal coronary angioplasty and thrombolysis in patients with coronary artery disease.

Thrombolysis and percutaneous transluminal coronary angioplasty (PTCA) are kinds of procedures that can be used to restore the blood flow of previously ischemic myocardium that can be the result of excessive production of reactive oxygen and nitrogen species, such as superoxide and hydroxyl radical, hypochlorous acid and peroxynitrite. Reaction of urate with some of these potent oxidants results in allantoin production. In this study, we measured the serum allantoin levels, an oxidation product of urate, and "in vivo" marker of free radical generation in reperfusion of ischemic myocardium.

Prevalence of zinc deficiency and immune response in short-term hemodialysis.

Zinc is an essential trace element for many biological functions, including immune functions. The mechanism by which zinc may affect the immune system is certainly multifaceted, due to zinc's widespread action on different enzymes, peptides, transcriptional factors and cytokines involved in the various physiological steps of immune development and reactivity. In this study, prevalence of zinc deficiency and alteration in complement system, immunoglobulins and T cell subsets depending on zinc levels were analyzed in short-term hemodialysis patients and compared with healthy controls.

Oxidation of uric acid in rheumatoid arthritis: is allantoin a marker of oxidative stress?

Free radicals are implicated in many diseases including atherosclerosis, cancer and also in rheumatoid arthritis. Reaction of uric acid with free radicals, such as hydroxyl radical and hypochlorous acid (HOCl) results in allantoin production. In this study, we measured the serum allantoin levels, oxidation products of uric acid, as a marker of free radical generation in rheumatoid arthritis.

The role of plasma thiol compounds and antioxidant vitamins in patients with cardiovascular diseases.

Background: Increased levels of homocysteine (Hcy) and cysteine (Cys) are associated with risk of cardiovascular diseases (CVD). These thiol compounds can generate various free radicals and so cause endothelial dysfunction. Antioxidant vitamins are effective scavengers of reactive oxygen species (ROS) and prevent endothelial dysfunction.

Plasma total homocysteine and cysteine levels as cardiovascular risk factors in coronary heart disease.

Objectives: As an important risk factor for coronary atherosclerosis, elevated plasma total homocysteine (t-hcy) concentration has recently received greater attention than have conventional risk factors. Though less reactive than homocysteine, cysteine (cys) is the most abundant plasma thiol and may function as an extracellular regulating factor of thiol/disulfide exchange in order to maintain an adequate redox status. An increase in the total amount of this compound may be noxious depending on environmental conditions.