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Biomedical subjects

G Ersöz

Publications and source records attributed to G Ersöz.

14 recordsLinked to original sources

Effect of submaximal and incremental upper extremity exercise on platelet function and the role of blood shear stress.

INTRODUCTION: Platelets are involved in the pathogenesis of atherosclerosis. Although physical exercise is recommended to prevent atherosclerosis, the effect of exercise on platelet function and the underlying mechanisms of these effects are not completely understood. Accordingly, we aimed to examine the effect of different intensities acute arm exercises on platelet function. In addition, we evaluated the effect of lipid peroxidation and fluid shear rate on platelet response. MATERIALS AND METHODS: Twenty four healthy sedentary male volunteers aged 18-24 years performed submaximal and incremental exercises by upper extremity ergometer. The shear rate in the right artery was measured by Power Doppler Ultrasound (US) at rest and immediately after exercise. Pre and postexercise maximum intensities of ADP and collagen-induced platelet aggregation were measured using the impedance technique. Bioluminescent detection of thrombin-induced platelet ATP release and measurement of thromboxane B(2) (TxB(2)) levels (as a marker of thromboxane A(2) (TxA(2)) formation) by enzyme-linked immunoassay were performed before and after exercise. RESULTS AND CONCLUSION: Shear rate increased after both submaximal and incremental exercise. Collagen-induced platelet aggregation increased after submaximal exercise, while ADP-induced aggregation and thromboxane B(2) levels did not alter with this protocol. Incremental exercise caused increased collagen and ADP-induced platelet aggregation and thromboxane B(2) levels. Neither of the protocols altered platelet ATP release. It was shown that acute upper extremity exercise increased platelet aggregation, without an increase in platelet release. Collagen-induced signalling pathways were more sensitive than those induced by ADP. The increase in thromboxane B(2) after incremental exercise implied increase in thromboxane A(2) formation and lipid peroxidation. Despite a significant correlation between platelet aggregation and thromboxane B(2) levels at rest, we found no clear-cut relationship between thromboxane A(2) formation, blood shear rate and platelet response to exercise.

Adenosine Diphosphate↗

The effect of submaximal exercise on platelet aggregation during late follicular and midluteal phases in women.

INTRODUCTION: The key role of platelets in the pathogenesis of atherosclerosis prompted considerable interest on the effect of physical exercise on platelets. Due to probable menstrual cycle variations, only a limited number of investigations have studied the effect of exercise on platelets in women. The study was undertaken to determine the effect of acute submaximal exercise on platelet aggregation and thromboxane A(2) (TxA(2)) formation in females during their late follicular and midluteal phases. MATERIALS AND METHODS: Twelve healthy, sedentary, female volunteers performed 15 min of cycling exercise at a workload that increased their heart rate to 75% of maximal in two phases of the menstrual cycle. The maximal rate of ADP and collagen-induced platelet aggregation was evaluated on citrated whole blood using the impedance technique. Thrombin-induced thromboxane A(2) formation was evaluated by the measurement of thromboxane B(2) (TxB(2)) level by enzyme-linked immunoassay. RESULTS AND CONCLUSION: No significant difference was found between maximal rates of platelet aggregation measured in the different phases of menstrual cycle. Collagen-induced platelet aggregation and platelet count increased significantly after the exercise in both late follicular and midluteal phases (p<0.05). ADP-induced platelet aggregation did not change due to the exercise during the two phases of menstrual cycle. The thromboxane B(2) level measured in the midluteal phase was significantly higher than that measured in late follicular phase at rest. It was significantly increased after the exercise in late follicular phase while no significant difference was found between pre-exercise and postexercise levels in the midluteal phase. The differences in thromboxane A(2) formation were pointed out in the changes in platelet reactivity status. The inhibitory systems for platelets need further investigations. Our findings support the idea that menstrual variations do not have pronounced and acute effects on both platelet aggregation and response of platelets to acute exercise.

Adenosine Diphosphate↗

Serum L-carnitine levels and lipoprotein compositions in chronic viral hepatitis patients.

OBJECTIVES: The aim of this study was to evaluate the serum L-carnitine levels and its effect on lipoproteins in chronic viral hepatitis B or C patients. DESIGN AND METHODS: Blood samples were taken from 41 patients and 30 healthy subjects after 12 h fasting. RESULTS: Patients' serum L-carnitine levels (11.19 +/- 6.67 mg/L) (p < 0.0001) and hepatic enzyme activities (AST and ALT) (49.02 +/- 42.80 and 58.35 +/- 57.51 U/L) (p < 0.0005) were significantly higher than controls'. Serum total (3.85 +/- 0.82 mmol/L), LDL (2.08 +/- 0.76 mmol/L) and HDL (1.02 +/- 0.29 mmol/L) cholesterol levels were significantly lower in patients (p < 0.01). On the other hand triglyceride levels (1.65 +/- 0.85 mmol/L) were significantly higher in patients (p < 0.05). CONCLUSIONS: The higher L-carnitine levels of patients may result from the leakage of hepatic cellular carnitine. If there is a decreased hepatic cellular carnitine levels, this may affect the transport of acetyl moiety for cholesterol synthesis and alter lipoprotein composition. Further investigation is needed for hepatic tissue L-carnitine levels.

Adolescent↗

Intestinal permeability in liver cirrhosis.

OBJECTIVE: To determine the changes in intestinal permeability in liver cirrhosis and to investigate whether intestinal permeability relates to the stage and aetiology of cirrhosis or existence of spontaneous bacterial peritonitis (SBP). DESIGN: A prospective study of intestinal permeability in patients with cirrhosis. SETTING: Gastroenterology and Nuclear Medicine Departments of Ege University Hospital. PARTICIPANTS: Intestinal permeability was assessed in 44 consecutive patients with cirrhosis and 10 healthy volunteers by measuring 24 h urine excretion of (99m)technetium diethyl triamine penta-acetic acid (99mTc DTPA). Cases with an associated disease, impaired renal function, continuing alcohol consumption and drug intake which is known to have an effect on intestinal permeability were excluded. MAIN OUTCOME MEASURES: Comparisons of 24 h urine excretion of 99mTc DTPA were made between the groups of cirrhotics and controls, different grades of cirrhosis (according to Child-Pugh criteria), alcoholic and non-alcoholic cirrhotics and cirrhotic patients with and without SBP. RESULTS: Patients with cirrhosis excreted 99mTc DTPA significantly more than controls (11.56 +/- 8.96% in cirrhotics and 4.30 +/- 1.49% in controls, P < 0.0001). There was no relationship of 24 h urine excretion of the tracer with the grade and aetiology of cirrhosis (12.20 +/- 9.47%, 11.41 +/- 9.84%, and 11.09 +/- 8.42%, in Child A, B, and C groups and 8.45 +/- 6.57% and 12.05 +/- 9.25% in alcoholic and non-alcoholic cirrhotics, respectively). No significant difference was found between cirrhotic patients with and without SBP in terms of excretion of the administered dose of 99mTc DTPA (9.98 +/- 9.47% and 12.20 +/- 8.82%, respectively). CONCLUSIONS: This study shows that intestinal permeability increased in cirrhotic patients regardless of the grade and aetiology of disease. The presence of SBP does not seem to be due to increased intestinal permeability.

Bacterial Infections↗

The effect of interferon therapy on erythrocyte membrane Na+,K+ ATP activity in patients with chronic hepatitis B and C virus infections.

In order to evaluate the effect of alpha interferon on erythrocyte membrane Na+,K+ ATPase (EC 3.6.1.37) activity, 10 patients with chronic hepatitis B virus (HBV) infection and 8 patients with chronic hepatitis C virus (HCV) infection were investigated. Erythrocyte membrane Na+,K+ ATPase activity was determined in controls and in patients with HBV and HCV infection. Na+,K+ ATPase activity was significantly less in untreated patients with (HBV) infection (n = 20; 0.134 +/- 0.073 mumol of phosphate produced per milligram of protein per hour) and (HCV) infection (n = 11; 0.144 +/- 0.049) when compared to the controls (n = 10; 0.219 +/- 0.055). Among these subjects patients were treated with interferon and following treatment, significant elevation of Na+,K+ ATPase activity was seen in patients with HCV (n = 8; 0.183 +/- 0.044; P = 0.049) and HBV (n = 10, 0.213 +/- 0.095, P = 0.0069) infections when compared with the pre-treatment values (n = 8; 0.152 +/- 0.050) and (n = 10, 0.131 +/- 0.083), respectively. Normalization of serum alanin amino transferase levels (ALT) at treatment cessation was seen in 8 of 10 (%80) HBV infected patients of whom 2 of 8 (%25) had sustained ALT responses within three months after the end of treatment. In HCV infected patients 1 of 8 (%12.5) had sustained response following treatment. At the end of treatment, although Na+,K+ ATPase was restored in both of the patients groups, relative changes in enzyme activity in relation to relative reduction in ALT levels as a response to IFN therapy were not correlated.

Adult↗

Clinicopathological features of rapidly progressive hepatitis C virus infection in HCV antibody negative renal transplant recipients.

BACKGROUND: Hepatitis C virus (HCV) infection acquired during dialysis treatment generally shows a relatively benign course after renal transplantation (RTx). However, less is known about the course of HCV infection acquired during or after RTx. METHODS: Clinical and histopathological assessment of 15 renal transplant recipients who acquired HCV infection during or after RTx. RESULTS: Alanine aminotransferase levels rose for the first time 1-19 weeks after RTx. HCV RNA was found positive in all patients, but anti-HCV became positive in only nine of them. During a mean follow-up of 21 +/- 12 months, jaundice appeared in 12 patients while ascites and/or hepatic encephalopathy occurred in six. Azathioprine was stopped in all patients. Cyclosporin was also stopped in four patients and in two of them prednisolone was also interrupted for a period of 3-7 weeks. Following this, ascites, hepatic encephalopathy and biochemical disturbances improved, while no deterioration was seen in graft function. Nine of the 15 patients had undergone two consecutive liver biopsies (LB). The first LB revealed cirrhosis in three and chronic hepatitis in six patients; the second LB showed cirrhosis in seven patients. The histological activity index (Knodell's score) progressed from 11.8 +/- 3.5 to 13.8 +/- 3.8. CONCLUSIONS: The results suggest that HCV infection acquired during or after RTx may run an unusual and rapidly progressive clinical and histopathological course at least in some of these patients. Decrease or withdrawal of immunosuppressive drugs may improve early hepatic failure without detrimental effect on graft function during that period.

Adult↗

Platelet aggregation and release function in hyperbaric oxygenation.

The aim of the study was to investigate the acute and chronic effects of hyperoxygenation on platelet aggregation and adenosine triphosphate (ATP) release. To observe the acute effects of hyperbaric oxygen (HBO2), seven New Zealand rabbits were exposed to 2.4 atm abs oxygen for 90 min (group 1). Eight other rabbits were further exposed to O2 daily for 20 days (group 2) to observe the chronic effects of HBO2. Adenosine diphophate (ADP) and collagen-induced platelet aggregation and ATP release were evaluated before and after oxygenation in groups 1 and 2. It was found that the maximal rate of ADP and collagen-induced platelet aggregation decreased after hyperbaric oxygenation in group 1. No significant alteration was observed in platelet responses at the end of 20 days of oxygenation in group 2. The adaptation of platelets of 2.4 atm abs O2 after 20 days of exposure seems to need further investigation.

Adenosine Diphosphate↗

Hydatid acute pancreatitis: a rare complication of hydatid liver disease. Report of two cases.

Acute pancreatitis (AP) is known to be a rare complication of hydatid disease. We present two cases of AP due to intrabiliary ruptured hydatid cysts of the liver. High serum and urine amylase levels and ultrasonographic findings, compatible with AP, were detected. On ultrasonography and computed tomography dilated bile ducts and cystic masses in the liver were seen. A communication between the bile ducts and a cyst in one case, and a total common bile duct obstruction with hydatid material in the other case, were seen on endoscopic retrograde cholangiopancreatograms. The patients were treated surgically with mainly omentoplasty. Recovery was uneventful. A diagnosis of AP should be kept in mind in patients with hydatid liver disease presenting with upper abdominal pain.

Abdomen, Acute↗

Effect of EGF on the corneal wound healing of alloxan diabetic mice.

We identified the local treatment effect of epidermal growth factor on corneal wound healing of alloxan diabetic mice. The corneal wounds were induced by 0.5 M NaOH solution on the corneal surfaces of the diabetic and non-diabetic groups. The local epidermal growth factor solution (100 ng ml-1) was dropped in 5-microliters aliquots into the eye twice a day. The corneal wounds were measured daily for 15 days and examined histologically at the end of 15th day of experimental period. The results indicated that topical epidermal growth factor treatment of diabetic and non-diabetic mice greatly improved the incidence of healing of wounded corneas.

Administration, Topical↗

The serum levels of soluble interleukin-2 receptor levels in patients with obstructive jaundice.

BACKGROUND/AIMS: Increased susceptibility to infection in patients with obstructive jaundice is well recognized. Depression of reticuloendothlial system phagocytic function and suppression of cellular immunity suggested by in vivo studies have been postulated as the cause. It has been shown that increased serum soluble interleukin-2 receptor (sIL-2R) levels are the marker of immune system activation, especially T cell activation. The purpose of this study was to evaluate cellular immune system activation by measuring serum sIL-2R levels in 18 patients with obstructive jaundice (11 with choledocholithiasis, 7 with malignant obstructive jaundice), 10 patients with liver cirrhosis and 10 healthy subjects. MATERIAL AND METHODS: Serum sIL-2R levels were measured by using ELISA (Boehringer Manheim). Lymphocyte subgroups were determined by flowcytometry. Serum immungolubulins (IgG, IgA, IgM) and autoantibodies such as antinuclear antibody, rheumatoid factor, anti-thyroglobulin and anti-microsomal antibody were measured. RESULTS: The levels of serum sIL-2R were found to be 47.1-121.2 (mean 77.3, SD +/- 20.1) pmol/l in healthy subjects, 82.8-199.2 (mean 150.9 +/- 32.2) pmol/L in patients with liver cirrhosis and 32.6-172.5 (mean 121.7 +/- 40.6) pmol/L in patients with obstructive jaundice. Serum sIL-2R levels were significantly higher in patients with liver cirrhosis or obstructive jaundice than in healthy subjects (p < 0.01 and p < 0.05 respectively). There is a significant difference in levels between patients with choledocholithiasis and with malignant obstructive jaundice (p < 0.01). Serum sIL-2R levels were measured higher in patients with liver cirrhosis than those in patients with obstructive jaundice (p < 0.059). CONCLUSIONS: In patients with obstructive jaundice, and to a lesser extent in those with liver cirrhosis, in vivo activation of immune system may be considered possible.

Aged↗