Evaluation of carotid intima-media thickness with vascular endothelial growth factor and malondialdehyde levels in patients with sarcoidosis.

PURPOSE: To assess the impact of sarcoidosis on endothelial function by measuring carotid intima-media thickness (CIMT) and serum levels of malondialdehyde and vascular endothelial growth factor (VEGF). MATERIALS AND METHODS: We prospectively analyzed 41 patients with sarcoidosis (9 men, 32 women) with a mean age of 44.9±10.2 (SD) years and 34 healthy subjects (9 men, 24 women) with a mean age of 37.26±8.9 (SD) years who served as a control group. Sarcoidosis patients receiving steroids were included in Group 1 while those not under steroid treatment were included in Group 2. CIMT measurements were performed using B-mode ultrasound. Malondialdehyde and VEGF serum levels were obtained in all sarcoidosis patients and control subjects. RESULTS: Both right and left CIMT was significantly higher in Group 1 and Group 2 than in control subjects. Serum levels of malondialdehyde and VEGF in Group 1 and Group 2 were significantly higher than in healthy subjects. No differences in CIMT, malondialdehyde and VEGF were found between Group 1 and Group 2. CONCLUSION: Sarcoidosis results in increased CIMT, VEGF and malondialdehyde serum levels. However, there was no difference in terms of CIMT, VEGF and malondialdehyde levels between sarcoidosis patients with or without steroid treatment, suggesting that new treatment strategies for sarcoidosis vascular involvement should consider this result.

Evaluation of measurement uncertainty of glucose in clinical chemistry.

The definition of the uncertainty of measurement used in the International Vocabulary of Basic and General Terms in Metrology (VIM) is a parameter associated with the result of a measurement, which characterizes the dispersion of the values that could reasonably be attributed to the measurand. Uncertainty of measurement comprises many components. In addition to every parameter, the measurement uncertainty is that a value should be given by all institutions that have been accredited. This value shows reliability of the measurement. GUM, published by NIST, contains uncertainty directions. Eurachem/CITAC Guide CG4 was also published by Eurachem/CITAC Working Group in the year 2000. Both of them offer a mathematical model, for uncertainty can be calculated. There are two types of uncertainty in measurement. Type A is the evaluation of uncertainty through the statistical analysis and type B is the evaluation of uncertainty through other means, for example, certificate reference material. Eurachem Guide uses four types of distribution functions: (1) rectangular distribution that gives limits without specifying a level of confidence (u(x)=a/ radical3) to a certificate; (2) triangular distribution that values near to the same point (u(x)=a/ radical6); (3) normal distribution in which an uncertainty is given in the form of a standard deviation s, a relative standard deviation s/ radicaln, or a coefficient of variance CV% without specifying the distribution (a = certificate value, u = standard uncertainty); and (4) confidence interval.

Lipid peroxidation and antioxidant defence system in patients with active or inactive Behçet's disease.

To evaluate plasma lipid peroxidation and enzymatic and non-enzymatic antioxidant systems in patients with Behçet's disease, plasma malondialdehyde levels and total antioxidant status, erythrocyte superoxide dismutase and whole blood glutathione peroxidase activities were studied in 15 patients with active disease and in 30 with inactive disease, and compared with 20 age-matched healthy control subjects. Plasma malondialdehyde levels were significantly higher in patients with active Behçet's disease than in patients with inactive disease, who had significantly higher levels than control subjects. The plasma total antioxidant status of both groups of patients was significantly lower than that of controls. Furthermore, whole blood glutathione peroxidase activity was significantly lower in patients with active versus inactive Behçet's disease. There were no significant differences in erythrocyte superoxide dismutase levels between the groups. In conclusion, there is an increase in oxidative stress in Behçet's disease. Despite this stress, the antioxidant system is deficient and inadequate, especially in patients who are in an active phase of the disease.

Avidin-biotin ELISA for measurement of prothrombin in human plasma.

In this study, IgG was partially purified from rabbit antisera against human normal prothrombin. The presence of antibodies against prothrombin was shown by Ouchterlony's double immunodiffusion method. This IgG was adsorbed to microwells and an enzyme-linked immunosorbent assay (ELISA) method was developed by using biotinylated prothrombin. We used alkaline phosphatase as the labeling enzyme. Plasma prothrombin concentrations in 30 healthy individuals and 15 patients with liver cirrhosis were measured using this ELISA method. Prothrombin levels of the cirrhotic patients (61+/-36 microg/ml) were significantly lower than those of the control values (117+/-43 microg/ml) (P<.001). In addition to the ELISA method in the same samples, we assayed prothrombin levels by nephelometry and prothrombin activities using staphylocoagulase and chromogenic substrate. With nephelometry, in healthy individuals, a mean value of 104+/-17 microg/ml and, in cirrhotic patients, a mean value of 51+/-26 microg/ml of prothrombin levels were detected. The prothrombin activities were 10532+/-2429 and 2433+/-330 U/l, respectively. In both methods, the prothrombin values of cirrhotic patients were also significantly lower than those of the healthy individuals (P<.001). The correlation coefficient between ELISA and nephelometry was r=.90, P<.01, and between ELISA and the amidolytic assay was r=.69, P<.01. Prothrombin times (PT) of cirrhotic patients (18.5+/-2.3 s) were significantly longer and albumin (2.4+/-0.5 g/dl) levels were significantly lower than those of normal values (P<.001). PT were negatively correlated with prothrombin levels assayed by ELISA (r=-.59, P<.01). This enzyme immunoassay technique can be used to measure prothrombin levels in plasma.