Ayhan Uysal

Effects of apocynin, an NADPH oxidase inhibitor, on levels of ADMA, MPO, iNOS and TLR4 induced by myocardial ischemia reperfusion

Purpose: In this study, the effects of apocynin, an NADPH oxidase inhibitor, on the levels of inducible nitric oxide synthase (iNOS) and the toll-like receptor 4 (TLR4), which are inflammatory mediators in myocardial ischemia-reperfusion (MIR) injury, and myeloperoxidase (MPO), which is the indicator of neutrophil infiltration and the endogenous nitric oxide synthase inhibitor asymmetric dimethyl arginine (ADMA) increasing with oxidative stress were investigated. Methods: MIR injury was accomplished by the application of occlusion for 30 minutes and reperfusion for 120 minutes in the left anterior descending artery (LAD). In the study, 21 Sprague-Dawley male rats were divided into three groups: a sham group (n = 7); a MIR group (n = 7); and a MIR + apocynin treatment group (n = 7, before the procedure, an intraperitoneal administration of 10 mg/kg of apocynin for 15 days). After reperfusion, iNOS, TLR4, MPO and ADMA levels in myocardial tissue were measured by ELISA. Results: While myocardial TLR4, MPO and ADMA levels increased in the MIR group, these parameters were found to be decreased significantly in the group treated with apocynin. Although iNOS levels showed an increase in the MIR group compared to the sham group and a reduction in the MIR+apocynin group, there was no statistically significant difference between the groups. Discussion: In our study, the effect of the treatment of apocynin in MIR on ADMA, MPO, iNOS and TLR4 levels in myocardial tissue was shown for the first time. It is thought that apocynin treatment may show a protective effect in MIR injury by affecting oxidative stress (ADMA) and inflammatory parameters (iNOS, MPO).

Management of Parapneumonic Empyema in Children

Empyema is a serious complication of bacterial pneumonia in children. Between July 1992 and July 1998, 53 children aged 7 months to 12 years (mean age, 5.5 years) were treated for empyema complicating pneumonia. After diagnostic thoracentesis, closed tube drainage was carried out with appropriate antibiotic therapy and other treatment strategies such as pleural lavage, intrapleural enzymatic debridement, decortication, or pulmonary resection, according to the effectiveness of drainage and clinical status. There was one death from toxic shock. It was concluded that early decortication in the chronic stage of the disease is a safe and effective treatment modality.

Effects of rosuvastatin on ADMA, rhokinase, NADPH oxidase, caveolin-1, hsp 90 and NFkB levels in a rat model of myocardial ischaemia-reperfusion : cardiovascular topic

Summary Aim Endothelial dysfunction, oxidative stress and inflammation are among the most important mechanisms of ischaemia–reperfusion (I/R) injury. Besides their cholesterol-lowering effects, statins are known to provide protection against myocardial dysfunction and vascular endothelial injury via nitric oxide-dependent mechanisms. The aim of this study was to investigate the effects of rosuvastatin on certain intermediates involved in the generation of nitric oxide (asymmetrical dimethyl arginin, ADMA, caveolin-1 and hsp 90), oxidative stress (rhokinase, NADPH oxidase) and inflammation (NFkB), using an in vivo model of myocardial infarction in the rat. Methods Adult male Sprague Dawley rats were divided into three groups (control, I/R and I/R after 15 days of rosuvastatin administration). Reperfusion was applied for 120 min following left anterior descending coronary artery ischaemia for 30 min. Caveolin-1, hsp 90 and NFkB levels were evaluated with the quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and ADMA, rhokinase and NADPH oxidase levels were evaluated with ELISA. Results While NFkB and hsp 90 levels were higher in the I/R group, their levels were significantly lower in the rosuvastatin group. While ADMA and NADPH oxidase levels significantly increased with I/R, they were lower in the rosuvastatin-treated group, but not statistically significant. Rhokinase levels were significantly lower in the rosuvastatin group. Caveolin-1 levels were not different between the groups. Conclusion Our results suggest that ADMA, rhokinase, NADPH oxidase, hsp 90 and NFkB could facilitate I/R injury, and rosuvastatin significantly reduced levels of these parameters. These results indicate that rosuvastatin may have a protective role in I/R injury via mechanisms targeting inflammation, endothelial dysfunction and oxidative stress.

In vitro effects of sodium nitroprusside and leptin on norepinephrine-induced vasoconstriction in human internal mammary artery : cardiovascular topic

Summary Aim The biological and pharmacological properties of vessels used in coronary artery bypass graft (CABG) surgery are as important as their mechanical properties. The aim of this study was to investigate the possible role of protein kinase C (PKC)-dependent mechanisms in leptin-induced relaxation in the human internal mammary artery (IMA). Methods IMA rings, obtained from patients undergoing CABG surgery, were suspended in isolated tissue baths containing Krebs-Henseleit solution, which were continuously gassed with 95% O2 and 5% CO2 at 37°C. Results The IMA rings were pre-contracted with increasing concentrations of norepinephrine (NE 10-9–10-4 mol/l) and the relaxation responses to sodium nitroprusside (SNP), a nitrosovasodilator, and leptin were studied in the presence and absence of a PKC inhibitor. Leptin (1 μM) caused a dose-dependent relaxation in NE pre-contracted IMA rings. Pre-treatment with a PKC inhibitor significantly attenuated this vasorelaxatory response to leptin in human isolated IMA. Conclusion It was found that SNP and leptin caused significant relaxation of the NE pre-contracted human IMA rings, and PKC was probably the sub-cellular mediator for this effect. Our findings may have clinical or pharmacological importance as it could be hypothesised that obese subjects who have a left IMA bypass graft would have better myocardial perfusion.

Relationship between mean platelet volume elevation and left ventricular mass index in hypertensive patients

Objectives: To compare the mean platelet volume (MPV; a general marker of platelet activation) in groups of patients with and without hypertension and to analyse its relationship with left ventricular mass index (LVMI). Methods: This cross-sectional, observational study enrolled newly diagnosed patients with untreated stage I–II hypertension and healthy control subjects without hypertension. MPV was measured using a haematology analyser. Echocardiography was performed on all of the study participants. Results: A total of 50 newly diagnosed patients with hypertension and 50 healthy control subjects were enrolled in the study. The majority of the demographic characteristics and laboratory findings were not significantly different between the two groups. The mean ± SD MPV was significantly higher in the hypertensive group compared with the control group (10.3 ± 1.4 fl versus 9.2 ± 1.8 fl, respectively). The mean ± SD LVMI was significantly higher in the hypertensive group compared with the control group (115.9 ± 23.0 g/m2 versus 95.7 ± 23.4 g/m2, respectively). There was no significant correlation between MPV and LVMI. Conclusion: In patients with untreated hypertension, despite elevated MPV levels there was no correlation between LVMI and MPV.

An Experimental Lymphoscintigraphy Study in an Acute Unilateral Deep Venous Thrombosis Model

BACKGROUND The aim of this study is to investigate the effect of both inguinal exploration and deep venous thrombosis on lymphatic flow in an experimental model of unilateral acute obstruction of the femoral vein. METHODS AND RESULTS Eighteen male New Zealand White rabbits were the subjects of this study. The rabbits were divided into three groups; Group 1 (n=6, control), Group 2 (n=6, sham), and Group 3 (n=6, operation). After the lymphoscintigraphy was performed on the Group 1 animals, the rabbits in Group 2 and Group 3 underwent intervention. In Group 3, the femoral vein was clipped and excised. In Group 2, an inguinal incision was performed and the clip materials were placed beneath the femoral vein. After the surgical intervention, lower extremity lymphoscintigraphy by subcutaneous administration of Tc-99m nanocolloid was performed in dynamic and static manner in Groups 2 and 3 on the second, fifteenth and thirtieth days after the operation. Unilateral impairment of the lymphatic flow in the operated extremity was observed in Group 3 in the early and late postoperative period but unilateral lymphatic impairment was observed in Group 2 in only the late postoperative period. CONCLUSION The lymphatic impairment in an operated extremity might be the consequence of surgical intervention rather than acute venous obstruction in cases where both situations are observed.