Biomedical subjects

O Durmus

Publications and source records attributed to O Durmus.

6 recordsLinked to original sources

PubMed2001

Leptin does not play a major role in platelet aggregation in obesity and leptin deficiency.

OBJECTIVE: A recent study suggested that high concentrations of leptin enhance platelet aggregations. Therefore, the aim of this study was to investigate whether platelet aggregation is altered in patients with leptin gene mutations compared with obese subjects or controls. RESEARCH METHODS AND PROCEDURES: Four men (one homozygous man and his three heterozygous brothers) carrying a leptin gene mutation; 20 age-matched, healthy, unrelated men; and 18 age-matched obese men were enrolled in the study. Adenosine diphosphate (ADP)-, collagen-, and epinephrine-induced platelet aggregation were evaluated in all individuals. RESULTS: Our results show that patients with the leptin gene mutation (both the homozygous and heterozygous patients) had significantly higher ADP-induced (78.3 +/- 3.4% vs. 57.9 +/- 9.3%, p = 0.001), collagen-induced (78.1 +/- 2.9% vs. 56.7 +/- 9.3%, p = 0.007), and epinephrine-induced (76.5 +/- 9.2% vs. 59.5 +/- 7.70%, p = 0.003) platelet aggregation compared with controls. However, ADP-, collagen-, or epinephrine-induced platelet aggregations were similar to those in obese patients. Platelet aggregation responses to a combination of pretreatment with leptin at concentrations of 20, 50, 100, or 500 ng/mL for 5 minutes and ADP at concentrations of 2 micromol/liter also were evaluated. However, we did not find significant increases in platelet aggregation even at high concentrations of leptin (100 or 500 ng/mL) in leptin-deficient patients, obese subjects, or controls. DISCUSSION: Our data show that similar to findings in obese humans, homozygous or heterozygous leptin deficiency is associated with increased platelet aggregation compared with controls, and that higher concentrations of leptin do not increase platelet aggregation.

Adenosine Diphosphate↗

PubMed2000

An alternative parameter for monitoring the therapeutic benefits of allopurinol simultaneously in renal ischaemia-reperfusion injury: MDA/ATP Ratio.

The therapeutic benefits of allopurinol pretreatment in renal ischaemia-reperfusion injury were investigated by monitoring renal malondialdehyde (MDA) and ATP levels together with calculated MDA/ATP ratio in ischaemic (45 min) and reperfused (15 min) rat kidneys. MDA levels remained unchanged during ischaemia, but increased after the subsequent reperfusion. ATP content of the ischaemic kidney was decreased significantly and the recovery of ATP was incomplete after the reperfusion, whereas the MDA/ATP ratio increased at both periods. Allopurinol pretreatment (40 mg kg(-1) iv) maintained higher ATP levels during the ischaemia and inhibited the MDA formation during the reperfusion and decreased the MDA/ATP ratio at both periods. Our findings demonstrate that allopurinol exerts a biphasic protective action by preserving tissue ATP and by inhibiting lipid peroxidation during ischaemia and the reperfusion period, respectively. These findings suggest the selective involvement of two protective mechanisms in the different periods of renal ischaemia-reperfusion injury. The MDA/ATP ratio could be a useful parameter for monitoring these protective actions of allopurinol simultaneously.

Allopurinol↗

PubMed1994

The effect of allopurinol on Na+K+ATPase related lipid peroxidation in ischemic and reperfused rabbit kidney.

1. Na+K+ATPase is a membrane bound enzyme whose activity is essential for maintenance of cell viability. Lipid peroxidation changes membrane fluidity and enzyme activity. 2. The purpose of this study was to investigate the effect of allopurinol (free radical scavenger) on Na+K+ATPase activity in rabbit kidney cortex membrane. In this in vivo study we created ischemia and reperfusion in rabbit kidneys. 3. Enzyme activity were low in ischemic and reperfused kidneys, compared to the controls. In allopurinol treated ischemic and reperfused groups, the levels of Na+K+ATPase activity were high compared to the untreated group. 4. It has been concluded that allopurinol may protect this enzyme activity.

Allopurinol↗

PubMed1993

Biochemical investigation of leukocyte functions during lithium therapy.

1. The effect of lithium on phagocytic activity of polymorphonuclear leucocytes (PMNL) has been investigated by measurements of glucose-6-phosphate dehydrogenase (G6PD), NADPH oxidase and myeloperoxidase (MPO) both in lithium treated rats and lithium treated infected rats. 2. The results have been compared with two control groups, one of which was without lithium treatment and the other was only infected. 3. In the first experimental group increased activities of these enzymes have been observed, while in lithium-treated infected rats there was a decrease in the activities of the same three enzymes. 4. It is proposed that defense mechanisms against infection fail during the lithium treatment.

Animals↗

PubMed1990

Acute appendicitis associated with pneumoperitoneum.

Spontaneous pneumoperitoneum is infrequently encountered as a radiographic finding in association with a perforated appendicitis. This may lead to diagnostic errors, of which every radiologist and surgeon should be aware. We report a case of perforated appendicitis associated with free intraperitoneal gas.

Acute Disease↗

PubMedDate not supplied

The effect of epidermal growth factor on liver lipid peroxidation and glutathione levels in lobectomized rats.

Epidermal growth factor (EGF) is a growth-promoting polypeptide which is found in highest levels in male mice in the submaxillary gland. It may also be a key factor in regeneration of the liver. We performed experiments with 18 male Wistar rats, divided into three groups. Hepatic left lobectomy (%30) was performed on the first group of rats. This group received an intraperitoneal injection of EGF for 7 days. The second group was the control group into which normal saline was injected for 7 days. The third group was sham-operated. On days 5 and 7 tomographic studies of liver were performed. On day 7 EGF levels, lipid peroxidation, and glutathione in liver were measured in all of the rats. While serum EGF levels did not show any significant change, the levels of lipid peroxide were decreased and glutathione was increased. Tomographic measurements indicated that administration of EGF increased the amount of regeneration.

Animals↗