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Biomedical subjects

Ahmet Var

Publications and source records attributed to Ahmet Var.

13 recordsLinked to original sources
PubMed2006

Trimetazidine reduces oxidative stress in cardiac surgery.

BACKGROUND: Trimetazidine is an anti-ischemic agent that is used to treat angina and it has cardioprotective effects without inducing any significant hemodynamic changes. It inhibits the long-chain mitochondrial 3-ketoacyl coenzyme A thiolase enzyme in the myocyte and can improve cardiac mitochondrial metabolism, as well as scavenge free radicals. The aim of this double-blind prospective randomized study was to investigate the effect of preoperative use of trimetazidine on the reduction of oxidative stress during coronary artery bypass grafting (CABG) under cardiopulmonary bypass (CPB). METHODS AND RESULTS: The study group (group T) and the control group (group C) each comprised 12 patients. Pretreatment began 2 weeks before CABG with trimetazidine (60 mg/day po); the control group did not receive any medication. Serial blood samples were collected before and after CPB for measurement of the serum concentrations of these major endogenous antioxidant enzyme systems, which are markers for oxidative degradation of the cellular membranes; postoperative levels were significantly different between the groups (p<0.05). There were no significant difference in hemodynamic values. CONCLUSION: The findings suggest that pretreatment with trimetazidine alleviates malondialdehyde production and preserves endogenous antioxidant capacity during CABG with CPB and cardioplegic arrest.

Aged↗
PubMed2004

Biochemical markers of bone metabolism and calciuria with inhaled budesonide therapy.

We investigated the changes in renal excretion of calcium, sodium, and potassium in asthmatic children treated with inhaled budesonide, an inhaled glucocorticoid. Twenty-two asthmatic patients (7 female, 15 male, mean age 10.1+/-4.3 years) treated with 400-600 microg/day inhaled budesonide and 23 healthy children (6 female, 17 male, mean age 10.2+/-2.8 years) were enrolled in the study. The parameters recorded were serum sodium, potassium, calcium, phosphorus, alkaline phosphatase (ALP), type I collagen carboxyterminal telopeptide (ICTP), osteocalcin, intact parathyroid hormone (PTH) levels, first spot morning urine calcium/creatinine ratio, sodium/potassium ratio, and daily renal calcium excretion rate (UCa-ER). These parameters were measured in the control group and pre- and post-budesonide treatment in asthmatic children. Serum electrolytes, ALP, PTH, ICTP, and UCa-ER were in the normal ranges and were not significantly different between controls and asthmatic children. Serum levels of ICTP increased, while levels of osteocalcin decreased after budesonide therapy in the asthmatic group ( P=0.001, P=0.005). UCa-ER was decreased after budesonide therapy in asthmatics ( P=0.000). In conclusion, moderate doses of inhaled budesonide cause hypocalciuria and decreased bone turnover. These results may be attributed to a mechanism compensating for decreased absorption of calcium in the gut due to the topical effect of swallowed budesonide rather than the systemic effects of the drug. Increased bone metabolism and decreased turnover may have an important role in this compensatory mechanism.

Administration, Inhalation↗
PubMed2004

The effect of simvastatin on serum cytokine levels and bone metabolism in postmenopausal subjects: negative correlation between TNF-alpha and anabolic bone parameters.

In this prospective study, we aimed to evaluate the effect of simvastatin on bone metabolism and the correlation between changes in bone turnover parameters and serum cytokine levels. For this purpose, 38 postmenopausal subjects with hypercholesterolemia (>240 mg/dl), not on osteoporosis treatment, were studied. Simvastatin was started at a dose of 20 mg daily and continued for 3 months. Six patients were excluded from the study during the follow-up period. Pre- and post-treatment samples were analyzed for bone alkaline phosphatase (BAP) and osteocalcin (OCL), as markers of bone formation; for carboxyterminal telopeptide of collagen I (CTX), as a marker of bone resorption; and for interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) cytokine levels. Total cholesterol level was decreased from 262.1 +/- 30.9 to 210.2 +/- 35.6 mg/dl after simvastatin treatment (P < 0.0001). While no significant change was observed in serum CTX level, BAP and OCL levels were significantly increased (from 120.8 +/- 56.6 to 149.5 +/- 57.6 IU/l [P = 0.008], and from 20.8 +/- 12.6 to 34.7 +/- 18.4 microg/l [P = 0.015], respectively). In the analysis of cytokines, while no significant change was observed in IL-6 levels, the TNF-alpha level was found to be significantly decreased after simvastatin treatment (from 77.9 +/- 31.6 pg/ml to 23.5 +/- 12.6 pg/ml [P = 0.021]). Individual changes in TNF-alpha levels showed a moderate negative correlation with the individual changes in BAP and OCL levels (r = -0.550 [P = 0.001], and r = -0.497 [P = 0.004], respectively). In conclusion; 20-mg daily simvastatin treatment for 3 months significantly increased BAP and OCL levels (markers of bone formation) in hypercholesterolemic postmenopausal subjects, without affecting bone resorption. These findings support the idea that simvastatin has an anabolic effect on bone formation. Additionally, the presence of a negative correlation between TNF-alpha levels and the anabolic bone parameters suggests that a cytokine-lowering effect of simvastatin may also be involved in the remodeling process and could exert some additive beneficial effect on bone metabolism.

Aged↗
PubMed2003

Endothelial dysfunction in preeclampsia. Increased homocysteine and decreased nitric oxide levels.

Endothelial dysfunction underlies the pathogenesis of preeclampsia, but its mechanism has not yet been completely understood. Elevated oxygen free radicals may partially explain the endothelial cell damage. In this study, we have aimed to measure homocysteine (Hcy) and nitric oxide (NO) levels as endothelial dysfunction markers in preeclamptic women. Nineteen preeclamptic (33.9 +/- 1.4 weeks) and 15 gestational-age-matched normal pregnant women (35.5 +/- 0.7 weeks) were included in the study. Mean NO level was significantly lower (p < 0.001) and mean Hcy level was significantly higher (p < 0.001) in the preeclamptic group. Elevated Hcy and oxygen free radical levels could decrease NO levels due to the reaction with each other and reduced NO may increase blood pressure and ischemia in preeclamptic patients. We have concluded that increased Hcy and oxygen free radical levels, and decreased NO levels are closely associated with preeclampsia-related endothelial dysfunction.

Adult↗
PubMed2003

Interleukin-6 levels in hyperemesis gravidarum.

INTRODUCTION: Hyperemesis gravidarum (HG) is associated with higher levels of serum beta-hCG levels and hyperthyroidism. Interleukin-6 (IL-6), a pro-inflammatory cytokine, is reported to enhance secretion of beta-hCG from trophoblastic cell line. METHODS: We measured serum levels of IL-6, thyroid hormones and beta-hCG of hyperemetic patients and gestational age-matched controls to search for a difference between the two groups. RESULTS: There was a significant difference in beta-hCG ( p=0.028), though IL-6 levels were higher in the hyperemetic group, it did not reach a significant level. Interleukin-6 positively correlated with beta-hCG ( r=0.38 and p=0.13).

Adult↗
PubMed2003

The relationship between serum trace element changes and visual function in heavy smokers.

PURPOSE: The aim of this prospective study was to evaluate serum manganese (Mn), zinc (Zn) and copper (Cu) levels and visual functions including visual acuity, colour vision, pattern visual evoked potentials (PVEPs), and contrast sensitivity in heavy smokers and to compare these with the equivalent levels and functions in non-smokers. METHODS: Data were recorded in 24 healthy, chronic and heavy cigarette smokers and 16 healthy, non-smoking control subjects. Serum Zn, Cu and Mn concentrations in all subjects were measured by atomic absorption spectrophotometry. RESULTS: Both study and control subjects had normal visual acuity and colour vision. Pattern visual evoked potentials were normal in all study and control subjects. Contrast sensitivity was significantly reduced in heavy smokers compared to non-smokers (p < 0.023), despite the fact that central vision and PVEP responses were not affected. Mean serum Mn and Zn levels were significantly lower in smokers than in non-smokers (p < 0.0001 and p < 0.005, respectively). CONCLUSIONS: Reduced contrast sensitivity values associated with low levels of serum Mn and Zn, which function as cofactors of superoxide dismutase in erythrocyte and other nucleated cells, suggest a possible role of trace elements in smoking-induced early retinal toxicity.

Adult↗
PubMed2002

Atherogenic profile in preeclampsia.

Atherosis is accepted to underlie the pathogenesis of preeclampsia, therefore we aimed to determine malonyldialdehyde (MDA) levels as a marker of lipid peroxidation, and lipoprotein(a) (Lp(a)), apolipoprotein A-1 (Apo A-1) and apolipoprotein B (Apo B) levels as a marker of atherogenic profile in preeclamptic and normal pregnant women. Twenty preeclamptic and 20 gestational-age matched normal pregnant patients were enrolled in the study, mean gestational ages for the preeclamptic and the control group were 33.9+/-1.4 and 35.5+/-0.7 weeks, respectively. Blood was withdrawn from the patients soon after diagnosis, and from the controls at their routine prenatal visits. MDA levels was significantly higher in preeclamptic patients (P=0.0003), but no difference was observed in Apo A-1 and Apo B and Lp(a) levels between the 2 groups. We consider that higher MDA was due to oxidative stress seen in preeclampsia, and similar Apo A-1 and Apo B and Lp(a) levels were due to lack of systemic atherosis.

Adult↗
PubMed2002

The protective role of caffeic acid phenethyl ester (CAPE) on testicular tissue after testicular torsion and detorsion.

Testicular artery occlusion causes an enhanced formation of reactive oxygen species, which contributes to the pathophysiology of tissue damage. Here, we have investigated the effects of caffeic acid phenethyl ester (CAPE), a new antioxidant and antiinflammatory agent, in rats subjected to testicular torsion/detorsion (T/D). Thirty-five male rats were divided into four groups: sham operation group ( n=8), torsion group ( n=9), T/D+saline group ( n=9) and T/D+CAPE group ( n=9). Rats, except the sham operation group, were subjected to left unilateral torsion (720 degrees rotation in the clockwise direction) without including the epididymis. After torsion (2 h) and detorsion (4 h) periods, rats were sacrificed and bilateral orchidectomy was performed. Testis tissues were washed with cold saline solution, cut into small pieces with scissors, placed into glass bottles and homogenised in four volumes of ice-cold Tris-HCl buffer. Clear supernatant fluid was used for biochemical analyses. Treating rats with CAPE (applied at 10 micro mol/kg, 30 min prior to T/D) attenuated the testicular injury, as well as the increase in the tissue levels of myeloperoxidase and thiobarbituric acid-reactant substances (TBARS) caused by T/D in the testis. Testis tissues showed a significant increase in glutathione peroxidase (GSH-Px) activity compared to the torsion group when CAPE was applied. Taken together, our results clearly demonstrate that CAPE treatment exerts a protective effect on testicular T/D, and part of this effect may be due to inhibiting the neutrophil-mediated cellular injury.

Animals↗
PubMed2002

Increased intraabdominal pressure impairs liver regeneration after partial hepatectomy in rats.

BACKGROUND: There are many experimental studies showing that increased intraabdominal pressure (IAP) reduces liver blood flow, leading to ischemia and portal venous congestion. But, there is no study evaluating the effect of increased IAP on liver regeneration. It is well known that acute liver ischemia and portal venous congestion impair liver regeneration. We, therefore, aimed to determine the effect of increased IAP on liver regeneration in this study. METHODS: Sprague-Dawley rats underwent partial hepatectomy with or without IAP of 12-14 mm Hg for 24 h or sham operation. Rats were randomly divided into six groups: two sham-operated groups, two hepatectomy groups, and two hepatectomy with increased IAP groups. Mitotic index, proliferating cell nuclear antigen (PCNA)-labeling index, and liver regeneration rate as liver regeneration parameters were studied on day 1 or on day 4 after operation. Additionally, serum aspartate transaminase (AST) level and histopathological changes in intestinal mucosa were studied. RESULTS: Hepatectomy with/without increased IAP groups had significantly higher serum AST levels than the sham-operated group on day 1. Serum AST level was found to be significantly higher in the hepatectomy with increased IAP group than in the other groups on day 4. Intestinal mucosal injury was found in the hepatectomy with increased IAP groups on days 1 and 4. Mitotic index and PCNA-labeling index were markedly higher in all hepatectomy with/without increased IAP groups than in the sham-operated groups. However, together with liver regeneration rate, both indices were significantly less in the hepatectomy with increased IAP groups than in the hepatectomy groups both on day 1 and on day 4. CONCLUSION: Maintenance of IAP between 12 and 14 mm Hg for 24 h impaired liver regeneration after partial hepatectomy in rats.

Abdomen↗
PubMed2002

Abdominal insufflation-deflation injury in small intestine in rabbits.

OBJECTIVE: To investigate the effect of increased intra-abdominal pressure followed by abdominal deflation on small intestine with or without previous intestinal ischaemia. DESIGN: Randomised experimental study. SETTING: University hospital, Turkey. ANIMALS: 78 male New Zealand white rabbits. INTERVENTIONS: Experiment 1: 30 rabbits (10 in each group) were subjected to intra-abdominal pressure of 0 mmHg (controls), 15 mmHg or 25 mmHg for 60 minutes. Experiment 2: 48 rabbits were divided into four groups (n = 12 in each). The first comprised sham-operated controls. In the other 3, the superior mesenteric artery was occluded for 60 minutes. Reperfusion was started and maintained under intra-abdominal pressure of 0 mmHg, 15 mmHg, or 25 mmHg for one hour. Intestinal specimens were obtained five and 60 minutes after abdominal deflation in the pressure groups and at identical times in the other groups in both experiments. MAIN OUTCOME MEASURES: Intestinal malondialdehyde concentration, wet:dry intestinal weight ratio, and mucosal injury score under light microscopy. RESULTS: In experiment I the malondialdehyde concentration, wet:dry weight ratio, and mucosal injury scores were higher in the 25 mmHg group than in the other groups in both specimens. There was a significant increase in malondialdehyde concentration in the 15 mmHg group in only the 5-minute specimen. In experiment 2, except for the wet:dry weight ratio in the 5-minute specimen in the 15 mmHg group, there were significant increases in malondialdehyde concentration, wet:dry weight ratio, and mucosal injury score in all groups except controls in both specimens. Malondialdehyde concentration and wet:dry weight ratio were higher in the 25 mmHg group than in the 0 mmHg group in the 60-minute specimen, and higher than the 15 mmHg group in both specimens. Wet:dry weight ratio was less in the 15 mmHg group than the 0 mmHg group in both specimens. Mucosal injury score was higher in the 25 mmHg group than the other groups in both specimens. CONCLUSION: Increased intra-abdominal pressure for 60 minutes followed by abdominal deflation led to an ischaemia-reperfusion-like injury in normal small intestine in rabbits, and added to reperfusion injury in the ischaemic small intestine at an intra-abdominal pressure of 25 mmHg.

Abdominal Injuries↗
PubMedDate not supplied

The effect of trimetazidine on liver regeneration after partial hepatectomy under hepatic blood inflow occlusion.

BACKGROUND/AIMS: It has been shown that hepatic blood inflow occlusion impairs liver regeneration. Our aim in this study was to investigate the effect of trimetazidine, known as an anti-ischemic and anti-oxidant agent, on liver regeneration after hepatic blood inflow occlusion. METHODOLOGY: Sprague-Dawley rats were randomized into three groups. Rats in group 1 underwent 65% hepatectomy. Rats in group 2 and 3 were subjected to 15 minutes of hepatic blood inflow occlusion during 65% hepatectomy. Rats were treated with saline (in group 1 and 2) or trimetazidine (in group 3) 30 minutes before operation. Serum level of aspartate transaminase, wet to dry liver weight ratio, and liver injury score in light microscopy were studied for the evaluation of liver injury. Liver regeneration was evaluated by PCNA-labeling index (the percentage of hepatocytes staining for proliferating cell nuclear antigen), mitotic index (the percentage of mitotic hepatocytes), and liver regeneration rate (the percentage of initial liver weight). RESULTS: Rats in group 2 and 3 had significantly higher serum aspartate transaminase level, wet to dry liver weight ratio and injury score than those in group 1 on day 1 posthepatectomy. Except for serum aspartate transaminase level on day 4, these parameters were significantly higher in group 2 than in group 1 and 3 on day 1 and 4. PCNA-labeling index and mitotic index were significantly less in group 2 and 3 than in group 1 on day 1. In contrast to liver regeneration rate, both indices in group 2 were significantly less than those in group 3 on day 1. There were no differences in regeneration parameters between the groups on day 4. Survival rate was significantly higher in group 3 than in group 2. CONCLUSIONS: Fifteen minutes of hepatic blood inflow occlusion caused an injury in the remnant liver, impaired liver regeneration, and decreased survival rate after partial hepatectomy. However, pretreatment with trimetazidine reduced liver injury, and improved liver regeneration and survival rate. For situations where hepatic blood inflow occlusion is planned in major liver resection, trimetazidine pretreatment would be useful strategy to improve postoperative outcome.

Animals↗
PubMedDate not supplied

Intestinal ischemia-reperfusion impairs liver regeneration after partial hepatectomy in rats.

BACKGROUND/AIMS: The deleterious effects of intestinal ischemia-reperfusion on liver are realized, but its effect on the regenerative capacity of the liver has not been studied. Our aim in this study was to determine the effect of intestinal ischemia-reperfusion on liver regeneration. METHODOLOGY: Sprague-Dawley rats were randomly divided into six groups; two sham-operated, two hepatectomy, and two hepatectomy with intestinal ischemia-reperfusion groups. To create intestinal ischemia-reperfusion, the superior mesenteric artery and collateral arteries supplying the small intestine were occluded for 20 minutes. Partial hepatectomy was performed during the period of ischemia. Ischemia-reperfusion injury in the mucosal layer of the small intestine was scored in light microscopy. Liver regeneration parameters (proliferating cell nuclear antigen labeling index for hepatocytes and liver regeneration rate), and serum levels of aspartate aminotransferase and alanine aminotransferase were studied on day 1 or 4 after operation. RESULTS: Mucosal injury score was high in the hepatectomy with intestinal ischemia-reperfusion groups. Liver regeneration rate and proliferating cell nuclear antigen labeling index were less in these groups than the hepatectomy groups on day 1 and 4. There were no differences in the serum levels of aspartate aminotransferase and alanine aminotransferase between hepatectomy and hepatectomy with intestinal ischemia-reperfusion groups. The mortality rate was higher in the hepatectomy with intestinal ischemia-reperfusion groups than the other groups. CONCLUSIONS: Ischemia and reperfusion of the small intestine impaired liver regeneration with high mortality after partial hepatectomy in the rats.

Alanine Transaminase↗