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Biomedical subjects

Ahmet Kahraman

Publications and source records attributed to Ahmet Kahraman.

At least 19 recordsLinked to original sources
PubMed2006

The effects of desferrioxamine and quercetin on hepatic ischemia-reperfusion induced renal disturbance.

BACKGROUND: The aim of this study was to analyze the effects of 45min of hepatic ischemia and 1h of reperfusion on renal oxidative stress parameters, on renal tissue damage, and the role of Desferrioxamin (Dfx) and Q on these parameters. METHODS: Thirty Wistar albino rats were randomized to five groups. Group I was the control group. Group II received no treatment. Groups III and IV received intramuscular injections of desferrioxamine (100mg/kg) and quercetin (50mg/kg), respectively. Group V was administered Dfx and quercetin in combination. After treatment for 3 days, groups II, III, IV, and V were exposed to total hepatic ischemia for 45min. Plasma alanine aminotransferase levels, renal malondialdehyde and reduced glutathione (GSH) activities were measured after reperfusion for 1h. Histopathological and ultrastructural analysis of renal tissues was carried out. RESULTS: Plasma creatinine and BUN levels were markedly increased in the IR group and pretreated groups. Kidney MDA increased in the IR group, Q and Dfx+Q significantly decreased kidney MDA Kidney GSH levels markedly decreased in the IR group, Dfx significantly increased kidney GSH. No evidence of overt injury was observed in any renal tissue under light and electron microscopy. CONCLUSIONS: Our data demonstrated that 45min of hepatic ischemia and 1h of reperfusion may alter renal functions and may cause oxidative stress on renal tissue. Q and Dfx seem to have a beneficial effect via the GSH system and modulation of MDA levels.

Animals↗
PubMed2006

Cytotoxic effects of volatile anesthetics with free radicals undergoing laparoscopic surgery.

BACKGROUND: Free radicals induced by several diseases can trigger oxidative stress, leading to the production of malondialdehyde (MDA) and protein carbonyl content (CB). Volatile agents are able to increase the extent of oxidative status. However, the effects of these agents together with pneumoperitonium (Pp) have not been reported. We aimed to investigate the role of volatile anesthetics and ischemic injury during Pp on free radicals and scavenging enzymes in laparoscopic abdominal surgery. METHODS AND MATERIALS: Forty patients were examined. Patients were randomly divided into four groups in order to receive sevoflurane-fentanyl (SF = 10), sevoflurane-N(2)O (SN = 10), desflurane-fentanyl (DF = 10), and desflurane-N(2)O (DN = 10), respectively. Tidal volume and ventilation frequency were kept unchanged during the operation. Intraabdominal pressure was remained constant at 12 mm Hg. Baseline values in venous blood samples were preoperatively taken and blood was also taken postoperatively at the 6th and the 24th hours. After collection of blood samples into citrate (3.5 mg/mL blood) containing glass tubes, erythrocyte sediments were prepared for the analyses. Then malondialdehyde levels, protein carbonyl content, and sulfhydryl (SH) groups were measured. RESULTS: The levels of MDA and protein carbonyl content were significantly higher at the 6th hour rather than the 24th hour postoperatively with desflurane anesthesia. In addition, SH groups were significantly different between the 6th hour and the 24th hour measurements (P < 0.05). In our study, desflurane caused a statistically significant increase in MDA levels and protein carbonyl content and a decrease in SH groups. When the two groups were compared, in the case of MDA and CB values, a significant increase was observed in the 6th and the 24th hour, where there was a decrease in SH groups in the desflurane group (P < 0.05). These parameters did not change in the sevoflurane group (P > 0.05). CONCLUSION: We concluded that desflurane was affected by desflurane with low flow anesthesia in patients undergoing laparoscopic abdominal surgery. Significant influence on oxidative stress and antioxidant mechanics was not seen with sevoflurane anesthesia. Our studies support that oxidant and antioxidant defense mechanisms were altered in the desflurane group and this alteration improved after a combination of desflurane-N(2)O.

Adult↗
PubMed2005

Mast cell stabilizator and antioxidant effects of epidermal growth factor (EGF) on gastric mucosal injury induced by ethanol in rats.

The role of epidermal growth factor (EGF), a polypeptide containing 53 amino acids, on protection and repair of ethanol-induced gastric mucosal injury was investigated in rats. In addition, the effects of EGF on the gastric damage were evaluated histopathologically. We used 48 Spraque-Dawley rats which were divided into [corrected] three groups as control rats, ethanol treated rats and ethanol+EGF treated rats. The ethanol group was given a gastric gavage containing 1 ml of 80% ethanol (v/v) prepared in distilled water. EGF (100 microg/kg) was given by intragastric gavage 30 min before the administration of ethanol. We studied histopathological evaluation and the histochemical heterogeneity of mast cells and its degree of degranulation. Besides, gastric tissue malondialdehyde (MDA), protein sulfhydryl groups (SH), and protein carbonyl levels were measured. EGF treatment stabilized mast cells degranulation and had lower polymorphonuclear leukocytes (PMNL) infiltration, ulcer index, histamine, and MDA; protein carbonyl levels were also lower, compared to the non-treated animals. EGF exerts a protective effect on gastric mucosa to ethanol-induced gastric injury probably through antioxidant and mast cell stabilizing mechanism.

Animals↗
PubMed2005

Plasma malondialdehyde and erythrocyte glutathione levels in workers with cement dust-exposure [corrected].

BACKGROUND: Chronic exposure to cement dust has been reported to lead to several health problems. Acute and chronic exposure to quartz are associated with the provocation of an inflammatory response and triggers an extensive host defense mechanism. These inflammatory reactions result in the secretions of cytokines, eicosanoids, lytic enzymes, chemotactic factors and reactive oxygen species (ROS). This study was designed to investigate the plasma oxidant and antioxidant status in cement plant workers. METHODS: Forty-eight non-smoker volunteer male cement plant workers and 28 non-smoker volunteer office male workers (control) aged between 27 and 56 were recruited. The concentrations of plasma malondialdehyde (p-MDA), and the erythrocyte glutathione (GSH) were measured in both groups. Pulmonary function tests, and exposed free silica fractions were also measured in different working places. RESULTS: Plasma MDA levels were found to be increased, while erythrocyte GSH levels to be decreased in cement workers (p < 0.001). Although no statistically significance was observed, pulmonary function tests were found to be decreased in cement workers. A negative correlation was observed between MDA levels and FEV1 and FEV1% levels. Although no statistically significant difference was found, MDA levels were found to be increased and GSH levels decreased in the working areas where silisium dioxide concentrations were found to be higher. CONCLUSIONS: In conclusion, the results presented in this study show that direct measurement of plasma MDA and erythrocyte GSH could be accepted as an indicator of oxidative injury in workers exposed to cement dust.

Adult↗
PubMed2005

The correlation between renal tissue oxidative stress parameters and TNF-alpha levels in an experimental model of ischemia-reperfusion injury in mice.

BACKGROUND: To investigate the relationship between oxidative stress and pro-inflammatory response of the renal tissue at different ischemia times in I/R mice. METHODS: Twenty-four male Swiss dormice were subjected to 30, 45 or 60 minutes of ischemia and then 60 minutes of reperfusion (Group 1 I 30/R60, Group 2, .I45/R60, and Group 3, I 60/R60 respectively). As markers of oxidative stress and antioxidant activity, levels of thiobarbituric acid reactive substances (TBARS), protein carbonyls and protein sulfhydryls (SH), tissue superoxide dismutase (SOD) and catalase (CAT) activities of the renal tissue and also renal tissue pro-inflammatory marker TNF-alpha levels were assessed. RESULTS: The levels of TBARS and protein carbonyl rised in I30/R60 group (p=0.01). In I45/R60 group, levels of TBARS, protein carbonyls and TNF-alpha levels were significantly higher while SOD and CAT activities (p=0.01), and the levels of SH were significantly decreased (p=0.05). These findings were more relevant for I60/R60 group. Higher TNF-alpha levels correlated positively with higher levels of TBARS, and protein carbonyls and negatively with SOD, CAT and renal tissue SH (p=0.001). CONCLUSIONS: In mice, oxidative stress after 45 minutes ischemia and 60 min reperfusion could induce pro-inflammatory cascade mediated through TNF-alpha.

Animals↗
PubMed2004

Which is more effective in the prevention of renal ischemia-reperfusion-induced oxidative injury in the early period in mice: interleukin (IL)-10 or anti-IL-12?

OBJECTIVES: Ischemia-reperfusion (I-R) injury induces production of reactive oxygen species (ROS) and some inflammatory mediators like tumor necrosis factor (TNF). We compared the effects of IL-10 and anti IL-12 antibody (Ab) on TNF-alpha production and oxidative stress markers. We also searched for which one, anti IL-12 or IL-10, is superior in the prevention of I-R induced oxidative stress. DESIGN AND METHODS: The animals were divided into four groups: control (n = 5), I-R (n = 5), I-R + IL-10 (n = 5), I-R + anti IL-12 Ab (n = 5). Mice were subjected to renal ischemia by clamping the left pedicle for 45 min, and were then reperfused for 1 h. RESULTS: Under conditions of IL-12 blockade and IL-10 treatment, I-R-induced tissue TNF-alpha levels were significantly reduced (P < 0.01). IL-10 treatment decreased I-R-induced thiobarbituric acid reactive substances (TBARS) and protein carbonyl content levels (P < 0.05). After IL-10 treatment, decrease in tissue reduced glutathione (GSH) levels were prevented. Renal superoxide dismutase (SOD) and catalase (CAT) activities were observed to be decreased after I-R. IL-10 treatment increased both SOD and CAT activities over control values (P < 0.05). CONCLUSION: These data indicated that IL-10 treatment may be more effective than anti-IL-12 treatment in the prevention of renal I-R-induced oxidative injury in the early period.

Animals↗
PubMed2004

Examination of changes caused by tubal sterilization in ovarian hormone secretion and uterine and ovarian artery blood flow rates.

OBJECTIVES: To examine the changes caused by tubal sterilization (TS) in ovarian hormone secretion and uterine and ovarian circulation. DESIGN: Tubal sterilization was performed by minilaparotomy and laparoscopy methods in 36 women. Blood samples were taken for hormonal tests on Preoperative Day 3 (D3) of the menstrual cycle, on Postoperative Days 13-15 (periovulatory period) of the same cycle and on D3 in the 1st and 6th months post-TS. Uterine and ovarian artery blood flow rates of the women were measured on the same days as hormonal tests by transvaginal color Doppler ultrasonography (TVCDUSG). The control group was composed of 15 volunteers in the same age group who preferred the barrier method and who had the same TVCDUSG and hormonal analyses in the same periods. RESULTS: There was a decrease in the uterine and ovarian artery pulsatility index (PI) measurements and an increase in serum luteinizing hormone (LH) and estradiol (E2) values during the periovulatory period as compared with preoperative and postoperative menstrual measurements in all groups. There was no difference between baseline uterine and ovarian artery PI and serum follicle-stimulating hormone, LH and E2 values and those measured on D3 of the menstrual cycle in the 1st and 6th months post-TS. CONCLUSIONS: The 6-month postoperative follow-up of groups that had undergone different TS methods showed no difference in uterine or ovarian artery blood flow rates or ovarian hormone secretion in comparison with baseline values.

Adult↗
PubMed2004

The comparison of the oxidative stress effects of different gases and intra-abdominal pressures in an experimental rat model.

BACKGROUND: Laparoscopy is used for almost all types of abdominal surgery because of its advantages, which include shorter postoperative hospital stay. However, pneumoperitoneum used to facilitate the visual field has severe metabolic, hemodynamic, and inflammatory consequences depending on the pressure level and the gas used. Helium (He), an inert gas, has been recommended for establishment of pneumoperitoneum since it does not alter the blood pH and PCO(2). Yet the oxidative response after He insufflation remains unknown. This study was undertaken to compare the levels of free radical production and antioxidant status following He and CO(2) pneumoperitoneum at different intra-abdominal pressure values. MATERIALS AND METHODS: The subjects were 40 Sprague-Dawley male rats randomized to the following groups: He 10 (n = 8) was subjected to He pneumoperitoneum at 10 mm Hg for 60 minutes; He 15 (n = 8) was subjected to He pneumoperitoneum at 15 mm Hg for 60 minutes; CO(2) 10 (n = 8) was subjected to CO(2) pneumoperitoneum at 10 mm Hg for 60 minutes; CO(2) 15 (n = 8) was subjected to CO(2) pneumoperitoneum at 15 mm Hg for 60 minutes; and Control (n = 8) was subjected to sham operation without pneumoperitoneum. At the end of the experiment blood samples were obtained and plasma malondialdehyde, carbonyl, and sulphydryl levels were measured. RESULTS: CO(2) pneumoperitoneum produced higher malondialdehyde and carbonyl responses and sulphydryl consumption compared to He, especially at 15 mm Hg (P = 0.01, P = 0.01, and P = 0.059, respectively). CONCLUSION: Helium seems to limit the postoperative oxidative response following laparoscopy.

Abdomen↗
PubMed2004

Effects of ascorbic acid on oxidative system and transient evoked otoacoustic emissions in rabbits exposed to noise.

OBJECTIVES/HYPOTHESIS: The objective was to investigate the effects of both noise exposure and ascorbic acid on oxidative status and hearing thresholds of rabbits. STUDY DESIGN: Randomized prospective animal study comparing oxidative parameters and otoacoustic emissions in two rabbit groups exposed to noise. One group was given ascorbic acid, the other group was not given any treatment. METHODS: Two groups of rabbits were used in the study; each group had six rabbits. The six rabbits in the first group were not given any treatment, whereas 500 mg intramuscular ascorbic acid twice daily for 2 1/2 days was given to the six rabbits in the second group. Transient evoked otoacoustic emissions were recorded in all animals before and after noise exposure. Total protein sulfhydryl groups, carbonyl contents, and malondialdehyde levels, as well as erythrocyte glutathione, superoxide dismutase, and catalase enzyme levels, were measured in all rabbits. All the rabbits were exposed to noise (100 dB sound pressure level, 1000 Hz, 1 h), and transient evoked otoacoustic emissions were recorded again. RESULTS: When oxidative parameters before noise exposure were compared, erythrocyte glutathione and catalase enzyme levels were detected to be higher in the second group (P <.05). In the first group of rabbits after noise exposure, total protein sulfhydryl groups were found to be reduced (P <.05), whereas plasma carbonyl contents and malondialdehyde levels were elevated significantly (P <.05). In this group, erythrocyte glutathione, superoxide dismutase, and catalase enzyme levels were low (P <.05). In the second group, which was given ascorbic acid, total protein sulfhydryl groups were reduced (P <.05), whereas plasma carbonyl contents and malondialdehyde levels did not change (P >.05) following noise exposure. In the second group, erythrocyte glutathione and catalase enzyme levels were reduced (P <.05), but superoxide dismutase levels did not change (P >.05). Transient evoked otoacoustic emissions after noise exposure were weak in both groups, but reproducibility and signal-to-noise ratios were higher in the second group (P <.05). CONCLUSION: Ascorbic acid treatment inhibited both lipid peroxidation and oxidative damage of proteins in rabbits exposed to noise. The study data suggest, at least, that oxidative status should be included in the physiopathology of noise-induced hearing loss; in addition, a brief application of ascorbic acid before noise exposure appeared to play a protective role for cochlea.

Animals↗
PubMed2004

Changes in serum markers of oxidative stress with varying periods of haemodialysis.

BACKGROUND AND AIMS: Oxidative stress possibly helps promote the progression and complications of chronic renal failure (CRF). Haemodialysis (HD) may aggravate oxidative stress. This controlled, cross-sectional clinical study with blind outcome assessment evaluated the effect of prolonged HD treatment on oxidative stress. METHODS AND RESULTS: Seventy patients (M/F = 33/37) with CRF and who were on HD were divided into six groups with differing treatment periods of HD; from 3 to 12 months to 85-120 months. Twelve healthy subjects acted as controls. The serum levels of thiobarbituric acid reactive substances (TBARS), total sulfhydryl (SH) groups and protein carbonyls (PCs) were determined. Compared with controls, PCs were increased in patients, and this positively correlated with the duration of HD. Treatment for more than 24 months caused the most striking increases in PCs, with relevant differences as compared to those on HD for a maximum of 12 months. Increasing periods of HD were associated with increases in TBARS and similar decreases in SH as compared with controls; the differences between the SH levels of those on HD for more than 84 months and those on HD for up to 24 months were significant. CONCLUSION: Our results indicate that HD continued for more than 2 years aggravates the latter. Decreased potential for oxygen-radical-scavenger activity becomes pronounced after 7 years of HD treatment.

Adult↗
PubMed2003

The antioxidative and antihistaminic properties of quercetin in ethanol-induced gastric lesions.

The role of reactive oxygen species in the pathogenesis of acute ethanol-induced gastric mucosal lesions and the effects of quercetin were evaluated in an experimental model. In addition, the effects of quercetin on gastric damage were evaluated histopathologically. Rats were divided into three groups as control rats, ethanol treated rats and ethanol+quercetin treated rats. Ethanol group was given a gastric gavage containing 1 ml of 80% ethanol (v/v) prepared in distilled water. Quercetin (200 mg/kg body wt.) was given by intragastric gavage 120 min before the administration of ethanol. Gastric tissue thiobarbituric acid reactive substance levels, carbonyl compounds, histamine levels and myeloperoxidase activities were found to be increased in ethanol treated rats and quercetin treatment reversed these increases. No statistically significant changes were found between all groups in catalase activity. The superoxide dismutase activity dropped significantly after ethanol treatment and quercetin treatment increased this enzyme activity. Gastric damage was confirmed histomorphometrically by significant increases in the number of mast cells and gastric erosions in ethanol treated rats. It was also confirmed that quercetin treatment significantly decreased the number of mast cells and reduced the area of gastric erosions. The results suggest that the gastroprotective effect of quercetin in this experimental model could be due to its antiperoxidative, antioxidant and antihistaminic effects.

Animals↗
PubMed2003

Effect of retroperitoneoscopic donor nephrectomy on tissue oxidative stress markers in rabbit pneumoretroperitoneum model.

BACKGROUND AND PURPOSE: Laparoscopic donor nephrectomy causes increased renal oxidative stress. There are no data about the effects of the retroperitoneoscopic route. The aim of our study was to evaluate the oxidative stress occurring in renal tissues during retroperitoneoscopic donor nephrectomy in a rabbit model. MATERIALS AND METHODS: Eighteen adult rabbits were randomized to three groups, each consisting of six rabbits. Group I (control) underwent 50-mL balloon dissection of the left retroperitoneal space without CO(2) insufflation. Group II (pneumoretroperitoneum) received a 3-hour CO(2) insufflation at a pressure of 10 mm Hg in the retroperitoneal space after balloon dissection. Group III (pneumoretroperitoneum with warm ischemia), in addition to the procedure applied in Group II, underwent left renal artery clamping for 3 minutes and reperfusion for the next 5 minutes. Bilateral nephrectomy was performed in all animals for analysis of oxidative stress markers. Concentrations of malonyldialdehyde (MDA), protein carbonyl, and reduced glutathione (GSH) were measured in renal tissue samples. RESULTS: The MDA and protein carbonyl content were increased both in the donor (P = 0.004 and P = 0.004, respectively) and in the remaining kidneys (P = 0.009 and P = 0.028, respectively) in Group II compared with Group I. There were no statistically significant increases in oxidative stress markers between Group II and Group III in donor kidneys. However, there were statistically significant decreases in MDA in the remaining kidneys in Group III compared with Group II (P = 0.009). CONCLUSION: Pneumoretroperitoneum causes increased oxidative stress in both donor and remaining kidneys. Short-term warm ischemia and reperfusion do not exert an additive effect on pneumoretroperitoneum-associated oxidative stress in donor kidneys.

Analysis of Variance↗
PubMed2002

Changes in hepatic TNF-alpha levels, antioxidant status, and oxidation products after renal ischemia/reperfusion injury in mice.

BACKGROUND: Ischemia/reperfusion (I/R) injury induces an inflammatory response and production of reactive oxygen species (ROS), which affects the organs remote to the sites of I/R. The aim was to assess the hepatic changes after renal I/R injury. MATERIALS AND METHODS: Twenty mice were subjected to either sham operation or varying degrees of renal I/R injury. Hepatic TNF-alpha levels, myeloperoxidase (MPO), superoxide dismutase (SOD), and catalase (CAT) activities and reduced glutathione (GSH) levels, thiobarbituric acid-reactive substances (TBARS), and protein carbonyl levels were evaluated to show hepatic response to renal I/R injury. RESULTS: Hepatic tumor necrosis factor-alpha levels were found to be increased significantly after 30 min ischemia-1 h reperfusion and remained elevated through 60 min ischemia-1 h reperfusion. Supporting the neutrophil recruitment, about 10-fold increase in MPO activity was detected after 30 min ischemia-1 h reperfusion. Antioxidant enzymes were detected to be decreased after 30 min ischemia-1 h reperfusion and reached to the minimum levels after 60 min ischemia-1 h reperfusion. Decreased levels of GSH and increased levels of TBARS and protein carbonyls after 60 min ischemia-1 h reperfusion supported the ROS-mediated biomolecular alterations. CONCLUSIONS: A minumum of 30 min ischemia-1 h reperfusion is enough to elicit remote effects of renal I/R injury. Care should be taken to protect other organs remote from I/R sites especially during renal surgery.

Animals↗
PubMed2002

Determination of cut-off values for leucocytes and bacteria for urine flow cytometer (UF-100) in urinary tract infections.

Leucocytes and bacteria in urine are the important indices for diagnosing urinary tract infections. Urine specimens from 260 patients were examined for leucocytes and bacteria with the UF-100 flow cytometer (Sysmex Corporation, Japan). The results obtained with the UF-100 were compared with those obtained by bacteriologic cultures of the same urine samples. Bacteriologic samples were found to be positive in 48 urine samples. The best detected cut-off value for bacteria is 3800/microL (senstivity = 73%, specificity = 78%) and 25/microL for leucocytes (sensitivity = 73%, specificity = 92%). In addition, comparison of leucocyte count by manually and with UF-100 shows good correlation (r = 0.91). A flow cytometric urinalysis analyzer operates in a time saving manner, increases throughput and decrease microscopy review rates. It also provides a reliable information to clinicians prior to bacteriologic culture results, in terms of leucocyte and bacteria count.

Bacteriuria↗
PubMedDate not supplied

Protective effects of quercetin on ultraviolet A light-induced oxidative stress in the blood of rat.

The oxidative effects of ultraviolet A (UVA) light (320-400 nm) and the antioxidant effects of quercetin were examined in rat blood. For this purpose, rats were divided into three groups: control, ultraviolet (UV) and ultraviolet + quercetin (UV + Q). The UV and UV + Q groups were irradiated for 4 h a day with UVA light (1.25 mW cm(2)) during periods of 3, 6 and 9 days. Quercetin (50 mg kg(-1) body wt.) was administered intraperitoneally in the UV + Q group rats before irradiation periods. Blood was taken 3, 6 and 9 days post-treatment. Plasma malondialdehyde (MDA) levels significantly increased after 9 days of daily exposure to UVA. Whole blood glutathione (GSH) levels significantly declined after 3-9 days of irradiation. Glutathione peroxidase activity on days 6 and 9 and glutathione reductase activities on days 3, 6 and 9 post-irradiation were diminished significantly. Superoxide dismutase and catalase activities decreased significantly 3-9 days post-irradiation. The administration of quercetin before the 9-day period of irradiation significantly reduced the increase in plasma MDA value. Whole blood GSH levels significantly decreased with the administration of quercetin on all days. Quercetin significantly increased antioxidant enzymes diminished by UVA irradiation. Exposure of rats to UVA light leads to oxidative stress, reflected by increased MDA and reduced antioxidant enzyme levels. The administration of quercetin appears to be a useful approach to reduce the damage produced by UVA radiation.

Animals↗