The relationship between shear rate and vessel diameter.
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Blood Vessels↗
Biomedical subjects
M Ercan
Publications and source records attributed to M Ercan.
Impaired plasma viscosity via increased cholesterol levels in peripheral occlusive arterial disease [correction of disase].
The aim of this study was to investigate the relationship between plasma viscosity and lipoprotein and apolipoprotein pattern in normo- and hypercholesterolemic patients with peripheral occlusive arterial disease (POAD). 40 patients with POAD have been selected (8 females and 32 males, mean age: 54+/-3.2 years) with clinically evident superficial femoral occlusive artery disease. They were separated into two groups as normocholesterolemic (plasma total cholesterol <200 mg/dl) and hypercholesterolemic (plasma total cholesterol >200 mg/dl). Plasma total cholesterol, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides, total protein, and albumin levels were determined by enzymatic methods using commercial kits. Levels of apolipoprotein AI (apo AI), and apolipoprotein B (apo B) were measured using a immunoturbidometric method. Plasma viscosity (PV) was measured by capillary viscometer. Classifying the patients with PAOD according to the cholesterol levels; hypercholesterolemic (mean total-cholesterol: 227.90+/-26.97 mg/dl) patients had significantly higher LDL-C, PV and triglyceride levels compared with nornocholesterolemic patients (p<0.001, p<0.001, p<0.001, respectively). HDL-C and apo B were significantly lower in hypercholesterolemic patients than in normocholesterolemic patients (p<0.001, p<0.001, respectively). PV was positively correlated with total cholesterol (r=0.485, p<0.05), atherogenic index (r=0.624, p<0.01), total-C/HDL-C ratio (r=0.624, p<0.05), and LDL-C/HDL-C ratio (r=0.707, p<0.001) in hypercholesterolemic patients with POAD. PV was higher in hypercholesterolemic patients with POAD than in normocholesterolemic patients with POAD. We suggest that POAD patients should be regarded as a heterogenous group with lipid and lipoprotein parameters in order to assess the microcirculation in the affected limb. In case of dyslipidemia in POAD patients an elevated plasma viscosity should be considered as coexisting risk factor.
Aged↗
Plasma viscosity as a cardiovascular risk marker in patients with proteinuria.
Plasma viscosity is a major determinant of capillary blood flow. It has been suggested that alteration in plasma viscosity contributes to impaired blood flow and to increased cardiovascular risk. The aim of this study was to investigate the plasma viscosity levels and its possible role in the cardiovascular risk in patients with low grade nephrotic proteinuria. 20 patients with low-grade nephrotic proteinuria (mean age: 35+/-5 years) and 20 healthy controls (mean age: 33+/-4 years) were participated in the study. Plasma viscosity was measured by Harkness capillary viscometer. Biochemical analysis were measured by commercial enzymatic kits. Plasma viscosity, plasma levels of creatinine, fibrinogen and triglyceride were increased in patients with proteinuria than in the healthy controls (p<0.001, p<0.001, p<0.001, and p<0.001, respectively). The plasma levels of total protein and albumin were significantly lower in patients with low grade nephrotic proteinuria than in healthy controls (p<0.001 and p<0.001, respectively). Plasma viscosity was negatively correlated with plasma albumin (r= -0.835, p<0.001) and total protein (r= -0.862, p<0.001) in proteinuric patients. When the correlation analyses were performed a significant positive correlation was found between plasma viscosity and fibrinogen (r=0.636, p<0.001). In the stepwise multiple regression analysis plasma viscosity was found to be related with plasma total protein (t= -6.456, p<0.001) in the patients. When the stepwise multiple regression analysis were performed in healthy controls, the significant relationship was only found between plasma viscosity and fibrinogen (t= +2.202, p<0.01). These results suggested that altered plasma composition associated with low-grade nephrotic proteinuria may be involving the determination of plasma viscosity. Thus, the plasma viscosity in patients with low-grade nephrotic proteinuria may have a prognostic value in assessing cardiovascular risk in this group.
Adult↗
Plasma viscosity in female patients with hypothyroidism: effects of oxidative stress and cholesterol.
Hypothyroidism is associated with atherosclerotic events, however, the mechanism is unclear. We investigated the effects of oxidative stress and cholesterol on plasma viscosity in female patients with hypothyroidism (n = 20; mean age: 45.5 +/- 5.5 years) at baseline and after L-thyroxine replacement therapy (average daily dose being 0.1 to 0.15 mg). Two blood samples were taken after 2.3 +/- 1.2 months. In hypothyroid state plasma viscosity and thiobarbituric acid reactive substance (TBARS; marker of oxidative stress were significantly higher (p < 0.001 and p < 0.001), and plasma protein thiol (antioxidants) levels were significantly lower (p < 0.001) than in the healthy state (female; n = 15). After L-thyroxine replacement therapy, patients reached to euthyroid state. In this state, the levels of plasma viscosity and TBARS were decreased (p < 0.001 and p < 0.001), and protein thiol levels were significantly elevated (p < 0.001). There was a significant correlation between plasma cholesterol and viscosity (r = 0.64, p < 0.001), as well as plasma protein thiol (r = -0.59, p < 0.001) in the patients. The correlation between viscosity and TBARS was weak (r = 0.29, p < 0.01). Therefore hypothyroidism may be associated with atherosclerotic process by different mechanisms.
Adult↗
Hemorrheological variables in critical limb ischemia.
BACKGROUND: Impaired hemorrheological properties may worsen the tissue hypoxia distal to an arterial narrowing in patients with peripheral arterial occlusive disease (PAOD). The objective of this study was to investigate the changes in red blood cell rigidity, blood viscosity and plasma viscosity as contributing factors in the development of hypoxia in patients with critical limb ischemia (CLI). METHODS: Forty patients with critical limb ischemia and 40 healthy subjects were included in the study. The subjects included in the study were non-diabetic with blood pressure measurements within the normal range. Compound known to interfere with hemorrheological parameters were not taken by the patients for at least 7 days prior to investigation. Routine blood counts (WBC, RBC, Hb, Hct), plasma fibrinogen levels, plasma total cholesterol levels, red blood cell rigidity, blood and plasma viscosity were determined in both groups. Statistical evaluation of the results of both groups was compared by student's "t"-test. The level of significance was set at p<0.05. RESULTS: Blood viscosity at a shear rate of 6.00 sec(-1) was found to be significantly lower in the CLI group (p<0.001), whereas no significant difference was encountered when blood viscosity was measured at a shear rate of 225 sec(-1). Plasma viscosity and plasma fibrinogen levels were comparable. Plasma total cholesterol levels were found to be significantly higher in the CLI group (p<0.05) and red blood cell rigidity significantly lower (p<0.001). CONCLUSIONS: These findings may provide new insights into the role of blood viscosity in patients with CLI contrary to the previous reports in the literature. Therapies that address red blood cell rigidity more directly may decrease tissue hypoxia distal to arterial narrowing by preventing hemolysis, improving microcirculation, and increasing oxygen carrying capacity and may be more beneficial for these patients.
Arterial Occlusive Diseases↗
Nimodipine attenuates lipid peroxidation during the acute phase of head trauma in rats.
Oxygen free radical-mediated lipid peroxidation is one of the major mechanisms of secondary damage in traumatic brain injury. We assessed the effects of nimodipine on lipid peroxidation 1 h after head trauma in rats. Nimodipine (1.5 microg/kg IV bolus injection) was given immediately after head trauma by either the carotid artery or the jugular vein. Placebo treated rats received saline by the same routes. Control rats received head trauma only. Sham-operated rats were the group without head trauma. Malondialdehyde (MDA), which is the end product of lipid peroxidation, was measured as an indicator of oxygen free radical formation in the brain tissue. The mean values for MDA in sham operated rats were 92.4 +/- 4.9 nanomoles/gram wet weight (nmol/gww) of brain tissue. In the control group, MDA content of the brain tissue was 120.8 +/- 9.4 nmol/gww. In placebo treated rats, the results were similar. In the groups receiving nimodipine via carotid artery or jugular vein, the mean values were 101.1 +/- 6.9 and 106.5 +/- 6.0 nmol/gww, respectively. These results indicate that nimodipine caused a significant decrease in lipid peroxidation when given in the acute phase of head trauma in rats. This occurred regardless of the route of injection.
Acute-Phase Reaction↗
Trace element levels in the experimental peritonitis.
Electron transfer from iron or copper ions to oxygen is an important example of cellular free radical initiation. Oxygen derived free radicals have been implicated as mediators of cellular injury in several model systems. To evaluate the importance of iron, copper and zinc levels on lipid peroxidation in peritonitis, we measured peritoneum malondialdehyde (MDA) as a marker of lipid peroxidation, zinc, copper, and iron levels during an animal model of intraperitoneal sepsis. Additionally the effects of the free radical scavenger alpha-tocopherol administration was studied. The peritoneum MDA, iron, copper and zinc levels were increased after induction of peritonitis with Escherichia Coli. The treatment with alpha-tocopherol was decreased the peritoneum MDA, iron and copper levels significantly, except the zinc level (p < 0.001, p < 0.001, p < 0.001, respectively). Additionally the alpha-tocopherol treatment for three days prior to injection of E.Coli more decreased MDA, copper and iron levels than that of the treatment with alpha-tocopherol at the time of injection of E. Coli (p < 0.001, p < 0.001, p<0.001, respectively). Our results indicated that copper, iron and zinc had important effects on peroxidation events in E. Coli induced peritonitis, and alpha-tocopherol treatment can improve the oxidant status.
Animals↗
Plasma and erythrocytes antioxidant status and trace element levels in proteinuric patients with moderate glomerular function.
The objective of the study was to investigate the effect of moderate glomerular dysfunction on oxidative stress. We determined the plasma and erythrocyte malondialdehyde (MDA) levels, as a marker of lipid peroxidation, erythrocyte glutathione (GSH) levels and activities of GSH-Px, GSH Red and SOD as an antioxidant enzymes, and plasma trace element levels containing Fe, Cu and Zn in twenty proteinuric patients (6.8 +/- 5.1 g/day) with moderate glomerular function and in 20 anemic control subjects. We found that the erythrocyte and plasma MDA levels and erythrocyte GSH-Px activities were significantly higher (p < 0.001, p < 0.001, p < 0.001, respectively) and the erythrocyte GSH levels and activities of GSH-Red and SOD activities were significantly lower (p < 0.001, p < 0.001, p < 0.001, respectively) in the patients than in the anemic subjects. Plasma Fe and Zn levels were not to be found significantly different in the patients compared to the anemic subjects. But plasma Cu levels were significantly higher in the patients (p < 0.05) when compared with the levels of anemic subjects. This study was concluded that cellular antioxidant activity decreases in proteinuric patients with moderate glomerular function. This may increase lipid peroxidation reactions by causing oxidative stress in erythrocyte membranes.
Adult↗
Plasma leptin levels in obese and non-obese postmenopausal women before and after hormone replacement therapy.
OBJECTIVE: the aim of this study was to investigate the effect of hormone replacement therapy (HRT) on plasma leptin levels in postmenopausal women, and the relationship between the plasma leptin levels and obesity. METHODS: premenopausal women with normal cycles (n=30; mean ages, 35.4+/-8.3 years) and postmenopausal women (n=45; mean ages, 49.5+/-4.7 years) were randomly selected. Women were classified as obese (BMI>27 kg/m(2)) and as non-obese (BMI<27 kg/m(2)). Blood samples were obtained from the premenopausal women at the beginning of cycle, and from the postmenopausal women before and 6 months after HRT. Plasma leptin levels were measured by radioimmunassay. RESULTS: plasma leptin levels were significantly higher in premenopausal women than in postmenopausal women (18. 60+/-5.0; 3.67+/-2.44 ng/ml, respectively, P<0.001). Obese premenopausal women (n=15) had significantly higher plasma leptin levels (24. 60+/-7.81 ng/ml) in comparison with the levels of the non-obese premenopausal women (n=15; 12.50+/-4. 63 ng/ml) (P<0.001). Although there was no significant difference in the plasma leptin levels between obese (n=25) and non-obese (n=20) postmenopausal women before HRT, plasma leptin levels were significantly elevated in both obese and non-obese postmenopausal women after HRT (P<0.001), and the obese women had significantly higher plasma leptin levels than the non-obese (29.05+/-10.53; 14.78+/-6.76 ng/ml, respectively, P<0.001). CONCLUSION: HRT is effective in the elevation of the plasma leptin levels in postmenopausal women, and in obese women the increase of the plasma leptin levels are more marked than the non-obese women after HRT.
Adult↗
The relationship between plasma viscosity and cholesterol in postmenopausal women on hormone replacement therapy.
In women, cardiovascular morbidity and mortality sharply increase after the onset of menopause. There is substantial evidence that hormone replacement therapy (HRT) may decrease the risk of coronary heart disease; however the mechanism is unclear. We investigated the relationship between HRT and plasma viscosity as well as cholesterol levels in postmenopausal women. 30 women were using HRT (HRT users), and 30 women were not using HRT (non-users). According to the classification of their plasma cholesterol levels, 30 women were hypercholesterolemic levels (hypercholesterolemic users n = 15, and hypercholesterolemic non-users n = 15), and the others were normocholesterolemic levels. While the highest plasma viscosity was measured in hypercholesterolemic users (1.291 +/- 0.053 cP), the lowest plasma viscosity was measured in normocholesterolemic users (1.127 +/- 0.056 cP). There was a significant correlation between plasma viscosity and cholesterol levels in the women on HRT (r = 0.76, p < 0.001). We have not found a difference neither in fibrinogen levels nor in triglycerides between users and non-users. These data demonstrated that HRT has beneficial effect on plasma viscosity; mainly in normocholesterolemic post menopausal women.
Blood Viscosity↗
Hypnotizability, pain threshold, and dissociative experiences.
BACKGROUND: There may be an association between pain threshold, hypnotizability, and dissociative experiences. The purpose of the present study was to examine this association. METHODS: Forty-one healthy subjects were included in the study. Pain thresholds were determined using a manual algometer. The Dissociative Experiences Scale was administered to all subjects. Hypnotizability of the subjects was assessed by the eye roll sign of the Hypnotic Induction Profile. There were 14, 15, and 12 subjects in the Grade 1, 2, and 3 groups, respectively. RESULTS: Highly hypnotizable subjects had lower pain thresholds and were more likely to report dissociative experiences than the less hypnotizable subjects. CONCLUSIONS: There is an association between pain threshold, hypnotizability, and dissociative experiences. It may be suggested that dissociative and somatic symptoms may be integrally linked and related to hypnotic suggestibility.
Adult↗
Intraarticular morphine administration provides pain relief after knee arthroscopy.
This present study investigated the effects of intraarticular morphine administration in 1 mg and 5 mg doses on post-operative pain relief and analgesic requirements for patients undergoing arthroscopic procedures. At the end of the operation patients were randomly allocated in a double-blinded fashion into three groups. The control group (Group 1) received normal saline 20 mL intraarticularly. The patients in the second and third groups received intraarticular morphine sulphate 1 and 5 mg in saline 20 mL, respectively. Post-operative pain was assessed on the 1st, 6th and 24th hour by visual analogue scale (VSA). Supplementary analgesic requirement and possible complications were also followed. The intensity of pain and analgesic requirement were reduced more in the morphine 5 mg group than in the control group. It is concluded, that the administration of intraarticular morphine 5 mg provides long-lasting and effective analgesia after knee arthroscopy.
Adult↗
Acupuncture and hypnotic suggestions in the treatment of non-organic male sexual dysfunction.
We have examined the effects of acupuncture and hypnotic suggestions, and compared them with placebo in the treatment of male sexual dysfunction with no detectable organic cause. The study comprised 15 men (mean age 36.7 +/- 10.43 years) who received acupuncture treatment, 16 men (mean age 38.4 +/- 10.75 years) who underwent hypnosis (mean age 35.3 +/- 11.52 years) and 29 men (mean age 36.2 +/- 11.38 years) who served as controls. They were interviewed periodically; the patients' reports were verified by interviewing their partners. Men who received placebo had a 43-47% improvement in sexual function, while the rates of improvement in the treated groups were higher, but not significantly so. The success rates of acupuncture and hypnotic suggestions were 60% and 75% respectively. Although the improvement was not statistically significant, treatment with acupuncture could be used as an adjuvant therapy in non-organic male sexual dysfunction. The only treatment superior to placebo seemed to be hypnosis. A more effective treatment may be obtained by combining these therapeutic modalities, but this needs further study.
Acupuncture Therapy↗
Efficacy of testosterone, trazodone and hypnotic suggestion in the treatment of non-organic male sexual dysfunction.
OBJECTIVE: To examine the effects of hypnotic suggestions or the administration of testosterone or trazodone to impotent men with no detectable organic cause for the impotence. PATIENTS AND METHODS: The study comprised 79 men in whom clinical and laboratory examinations revealed no organic cause for their impotence: 20 men (mean age 38.7 +/- 11.47 years) received testosterone, 21 men (mean age 39.5 +/- 10.73 years) received trazodone, 20 men (mean age 34.2 +/- 11.69 years) underwent hypnosis and 18 men (mean age 39.1 +/- 11.46 years) served as controls. They were assessed by interview 4, 6 and 8 weeks after starting treatment: the patient's reports were verified by interviewing their partners. RESULTS: Men who received a placebo had a 39% improvement in sexual function, while the rates of improvement in the treated groups were higher, but not significantly so. The success rates of testosterone and trazodone treatment and hypnotic suggestions were 60%, 67% and 80%, respectively. CONCLUSION: Although the improvement was not statistically significant, treatment with testosterone and trazodone could be used as an adjuvant therapy in nonorganic male sexual dysfunction. The only treatment superior to placebo seemed to be hypnosis. A more effective treatment may be obtained by combining these therapeutic modalities, but this needs further study.
Adult↗
Anaesthetic management of a patient with von Hippel-Lindau disease: a combination of bilateral phaeochromocytoma and spinal cord haemangioblastoma.
The management of patients with Hippel-Lindau disease is discussed and illustrated using a case report. The importance of associated phaeochromocytoma and spinal involvement is stressed.
Adrenal Gland Neoplasms↗
Anaesthetic management in maple syrup urine disease.
Two children with maple syrup urine disease undergoing emergency and elective surgery are reported. The administration of ketamine to a 12-month-old boy without neurological problems and propofol infusion to a 5-year-old girl with a history of convulsions, was uneventful. We believe that a full knowledge of the pathophysiology of maple syrup urine disease and potential peri-operative problems associated with the disease are essential, so that patients are not subjected to unnecessary risks.
Anesthesia, General↗
Effects of vitamin A on immunological deficiencies in rats with obstructive jaundice.
OBJECTIVE: To investigate the ability of an immunostimulant, vitamin A, to reverse dysfunction of the mononuclear phagocyte system and impaired peritoneal neutrophil chemotaxis in rats with obstructive jaundice. DESIGN: Open laboratory study. SETTING: Medical School, Turkey. MATERIAL: 60 male Wistar-Albino rats. INTERVENTIONS: Two different experimental studies with 30 rats each were performed. Ten of the 20 rats in which the common bile duct was ligated and divided, were given vitamin A (vitamin A group) and the other 10 were given saline (saline group). Ten rats which underwent laparotomy with mobilisation of the common bile duct (sham group) were given saline. Rats in the vitamin A group were given 200 IU/g/day vitamin A and other groups of rats had an equal volume of saline intraperitoneally for 20 days. MAIN OUTCOME MEASURES: Function of the mononuclear phagocytic system was studied by the use of 99mTc sulphur colloid uptake, peritoneal neutrophil chemotaxis was measured by the Boyden chamber method, and liver function tests were studied 21 days after operation. RESULTS: Hepatic uptake of 99mTc sulphur colloid decreased, and lung uptake increased in the saline group compared with the sham and vitamin A groups (p < 0.05). Neutrophil chemotaxis was reduced in the saline and vitamin A groups compared with the sham group (p < 0.05). Serum aspartate aminotransferase and alanine aminotransferase activities and unconjugated bilirubin concentrations in the saline group were higher than in the vitamin A and sham groups (p < 0.05). CONCLUSION: Vitamin A stimulates mononuclear phagocytic function in jaundiced rats. It also improves liver function and may enhance peritoneal neutrophil chemotaxis.
Adjuvants, Immunologic↗
Blood flow determination in contralateral ovary with 133 Xe in unilateral ovarian torsion (experimental study in rabbits).
Clinical and experimental studies have shown that, in unilateral testicular torsion, some structural and hormonal changes may occur in the contralateral testis. The present study was designed to determine the effect of unilateral ovarian torsion on the blood flow in the contralateral ovary using #133Xe. Basal blood flow of the bilateral ovaries was determined in 40 prepubertal, female New Zealand rabbits. Right ovaries were then torsioned 720 degrees in all groups with the exception of the control group, where only laparotomy was performed. Bilateral ovarian blood flows were measured in the first group one hour after torsion, in the second group 8 hours after torsion, in the third group 24 hours after torsion and at the same times after laparotomy in the control group. Basal and post torsional blood flow measurements were analyzed. Contralateral ovarian blood flow was reduced after unilateral torsion in all of the groups. In the control group, there were no changes in these criteria.
Animals↗