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Biomedical subjects

I Durak

Publications and source records attributed to I Durak.

At least 91 records · Page 5Linked to original sources
PubMed1994

Adenosine deaminase, 5'nucleotidase, xanthine oxidase, superoxide dismutase, and catalase activities in cancerous and noncancerous human bladder tissues.

Activities of adenosine deaminase (ADA), 5'nucleotidase (5NT), xanthine oxidase (XO), superoxide dismutase (SOD), and catalase (CAT) enzymes were measured in cancerous and cancer-free adjacent bladder tissues from 36 patients with bladder cancer and in control bladder tissues from 9 noncancer patients. Increased ADA and decreased XO, SOD, and CAT activities were found in cancerous bladder tissues compared with those of cancer-free adjacent tissues and of control bladder tissues. Differences were also found between enzyme activities in the bladder of different disease stages and grades. In the cancerous tissues, only positive intracorrelations were found, but in the cancer-free adjacent tissues and control tissues, both positive and negative correlations were established between enzyme activities. Results suggested that purine metabolism and salvage pathway activity of purine nucleotides were accelerated in the cancerous human bladder tissues via increased ADA and decreased XO activities, probably together with changes in some other related enzyme activities and, free radical metabolising-enzyme activities were depressed in cancerous bladder tissues, which indicated exposure of cancerous tissues to more radicalic stress.

5'-Nucleotidase↗
PubMed1994

Serum adenosine deaminase and total superoxide dismutase activities before and after surgical removal of cancerous laryngeal tissue.

In this study, pre- and post-operative serum activities of adenosine deaminase (ADA) and total superoxide dismutase (SOD) enzymes were measured in patients with squamous cell laryngeal cancer. Activities of both enzymes were found to be higher in cancerous patients compared to the controls. No significant differences were found however between pre- and post-operative values for both enzymes in the patient group. It has been suggested that ADA and SOD enzymes leak from the cancerous laryngeal tissues into the blood stream. The absence of differences between pre- and post-operative serum enzyme activities has two possible explanations: Firstly, removal of previously released enzymes from the blood stream takes a much longer period than one month; and secondly, cancerous laryngeal tissue is not the only source of the enzymes mentioned even after removal of cancerous tissue by surgical operation, other sources such as adjacent tissues and/or metastatic tissues etc, still release these enzymes into the blood stream.

Adenosine Deaminase↗
PubMed1994

Reduced erythrocyte defense mechanisms against free radical toxicity in patients with chronic renal failure.

In this study, activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) enzymes were determined in the erythrocytes from patients with chronic renal failure (CRF) and from healthy subjects. In the conservative drug management group and intermittent ambulatory peritoneal dialysis group, CAT activity was lower than in the control group. However, SOD and GSH-Px activities of these groups were not statistically different from the control values. In the continuous ambulatory peritoneal dialysis group and the hemodialysis group, SOD, GSH-Px and CAT activities were lower than control values. In the patient groups, correlation coefficients between the enzyme activities were also found to be different from the control values. Results suggested that enzymatic antioxidant defense mechanisms were suppressed in the erythrocytes from the patients with CRF, in particular in the erythrocytes from those who were under hemodialysis and continuous ambulatory peritoneal dialysis management. It is proposed that reduced antioxidant defense mechanisms in the erythrocytes is one of the important factors leading to peroxidation in the membrane lipid structure of the erythrocytes and thereby to hemolysis and anemia in the patients with CRF.

Adolescent↗
PubMed1994

Plasma chromium levels in hypoglycemic preterm, full-term and in intrauterine-growth-retarded babies.

Serum chromium levels of hypoglycemic preterm and full-term babies were investigated. Normoglycemic preterm and full-term babies were selected as the control group. There was no statistically significant difference in serum Cr levels between preterm and full-term, hypoglycemic and normoglycemic, preterm hypoglycemic and preterm normoglycemic, full-term hypoglycemic and full-term normoglycemic babies. Serum Cr levels of intrauterine-growth-retarded babies were relatively low compared to infants appropriate for gestational age. Serum Cr levels of babies with mothers younger than 35 years of age had significantly lower levels than older mothers' babies.

Chromium↗
PubMed1994

Nd:YAG laser posterior hyaloidotomy in subhyaloid hemorrhage.

Subhyaloid hemorrhage is usually a benign condition that generally improves spontaneously and rarely causes visual loss. However, because subhyaloid hemorrhage may be associated with permanent macular changes before it spontaneously resolves, posterior Nd:YAG hyaloidotomy may be indicated in selected patients. We performed Q-switched Nd:YAG laser posterior hyaloidotomy via the transcorneal route in two cases of subhyaloid hemorrhage. The hemorrhage instantaneously drained into the vitreous cavity, resulting in a dramatic increase in visual acuity.

Adult↗
PubMed1993

Adenosine deaminase, 5' nucleotidase, xanthine oxidase, superoxide dismutase, and catalase activities in cancerous and noncancerous human laryngeal tissues.

We determined activities of adenosine deaminase (ADA), 5' nucleotidase (5NT), xanthine oxidase (XO), superoxide dismutase (Cu-Zn SOD), and catalase (CAT) enzymes in 15 human laryngeal tissues with well-differentiated squamous cell carcinomas, in 15 corresponding tumor-free adjacent tissues and in 7 normal laryngeal tissues. We found lower ADA and 5NT and higher XO, Cu-Zn SOD, and CAT activities in cancerous tissues than those in corresponding noncancerous ones. In the correlation analysis, we established one positive intercorrelation, which was between ADA activities of tumor tissues and noncancerous adjacent tissues. We also found some significant intracorrelations between enzyme activities of the tissues, all of which were positive in cancerous ones.

5'-Nucleotidase↗
PubMed1993

Efficiency of extracorporeal shockwave lithotripsy on calcium-oxalate stones: role of copper, iron, magnesium and zinc concentrations on disintegration of the stones.

Clinical use of extracorporeal shockwave lithotripsy (ESWL) in the noninvasive management of urinary calculi is highly effective and practical. But its results vary in relation to several factors including localization, size and the chemical composition of the stones. Moreover, the anatomy of the kidneys treated is another contributing factor to the success rate of ESWL in upper urinary tract stones. Currently, except cystine and struvite stones, the efficiency of ESWL has been proved and has become the most outstanding therapy for calculi in a great number of stone centers. In this study, the efficiency of ESWL treatment in respect to the concentrations of 4 different trace elements (Cu, Fe, Mg and Zn) in the chemical composition of Ca-oxalate monohydrate stones have been evaluated in 20 patients.

Adult↗
PubMed1993

Glutathione peroxidase activity in serum during acute myocardial infarction and unstable angina pectoris.

We studied GSH-Px enzyme activity in serum after acute myocardial infarction (AMI) and unstable angina pectoris (UAP). The study included 15 patients with AMI and 9 patients with UAP. Serum GSH-Px activity in the AMI group (0.992 +/- 0.071) (IU/ml) was higher than that of the UAP group. Serum GSH-Px activity was established as 0.683 +/- 0.110 (IU/ml) in UAP and 1.012 +/- 0.121 (IU/ml) in 10 healthy subjects (p < 0.0005). We suggest that measurement of serum GSH-Px activity together with other enzyme tests such as CK-MB, LDH, GOT, etc. can be helpful in the differentiation of AMI from UAP.

Angina, Unstable↗
PubMed1992

Analysis of calcium, iron, copper and zinc contents of nucleus and crust parts of urinary calculi.

In this study we compared the concentrations of calcium, iron, copper and zinc in the nucleus and the crust parts of various kinds of urinary calculi. We found that the mean concentrations of iron, zinc and copper in the nucleus parts of the stones were statistically higher than those in the crust parts. We attempted to explain this finding by two different approaches. Inter- and intra-correlations were also sought between the elements in the nucleus and crust parts. These correlations suggested a complex relationship between the elements of the urinary calculi.

Calcium Oxalate↗
PubMed1992

Malignant melanoma of the optic nerve head in a case of oculodermal melanocytosis.

Malignant melanoma of the uveal tract, orbit, and brain have been reported to occur in patients with oculodermal melanocytosis. A 60-year-old Caucasian man with oculodermal melanocytosis developed a malignant melanoma of the optic nerve head in the left eye. This case is the first reported example of a malignant melanoma developing in the optic nerve associated with oculodermal melanocytosis. After presentation the patient refused surgery for 19 months and the progression of the tumour necessitated an exenteration of the orbit.

Cranial Nerve Neoplasms↗
PubMed1991

Sodium, potassium and chloride concentrations in the inner nucleus and outer crust parts of urinary tract calculi.

In this study sodium, potassium and chloride concentrations were analysed in the nucleus and crust parts of various kinds of urinary tract calculi. Concentrations of these elements in the nucleus were found to be higher than those in the outer crust part. Moreover, some intra- and inter-correlations were established among the elements mentioned in these two parts of the stones. It was also determined that sodium, potassium and chloride concentrations in the nucleus and crust of various urinary tract stones exhibited statistically significant differences.

Chlorides↗
PubMed1990

Iron, copper, cadmium, zinc and magnesium contents of urinary tract stones and hair from men with stone disease.

Forty-seven urinary tract stones consisting of 5 pure magnesium ammonium phosphate (subgroup 1), 5 mixed calcium oxalate-magnesium ammonium phosphate (subgroup 2), 8 mixed calcium oxalate-calcium phosphate (subgroup 3), 6 mixed calcium oxalate-uric acid (subgroup 4) and 23 pure calcium oxalate stones (subgroup 5) and hair from these patients and control subjects were analyzed for iron, copper, cadmium, zinc and magnesium content by atomic absorption spectroscopy. Mean values +/- SD for each group were determined and statistical correlations were made to establish differences among the stone elements themselves, the hair elements themselves, and the stone and hair elements for group 5 (calcium oxalate stone group). We found significant differences among the element levels of the stones, patient hair and control hair. In particular, hair magnesium and cadmium levels of control and patient groups appear to have promising features for future work concerning urinary tract stone disease.

Adult↗