CK-MB mass test in ischemic myocardial injury. Comparison of two tests: BioMerieux Vidas and sanofi access immunoassays.

The analytical and clinical performances of the new fluorescent immunoassay (CK-MB mass Vidas-BioMerieux) were examined and compared to the chemiluminescent test (CK-MB mass Access-Sanofi-Pasteur). Assay precisions of the CK-MB Vidas test within-assay or between-assay were less than 5.4 and 5.3%, respectively. Linearity was tested up to 214 microg/L. The CK-MB Vidas test was free of interference with CK-BB, CK-MM, and macro-CK. One hundred nineteen blood samples from patients with ischemic myocardial injury (IMI): acute myocardial infarction (AMI), suspected myocardial contusion (SMC), and unstable angina pectoris (UA), were tested using both immunoassays. In AMI, a good correlation was found (Y [CK-MB Access] = 1.1372 x [CK-MB Vidas] - 6.3902; r(2) = 0.96). In UA and SMC, low values were observed and both methods were well correlated (Y [CK-MB Access] = 1.3662 x [CK-MB Vidas] + 0.0671; r(2) = 0.97). Clinical data were in good agreement with both immunoassays. ROC analysis performed in AMI demonstrated that the clinical performances of the two assays were similar.

p53 and follow-up of colorectal adenocarcinomas.

Circulating p53 antibodies (ELISA method), p53 genetic alterations (SSCP), and protein overexpression (immunohistochemistry) were studied in 41 patients with colorectal adenocarcinomas and 10 control patients. Carcinoembryonic antigen (CEA) and carbohydrate antigen 19.9 (CA 19-9) were evaluated in parallel. Ten patients with p53 antibodies and p53 overexpression were selected. Tumor DNA extracts from these 10 patients were analyzed by SSCP. Of all 41 patients, 10 (24%) showed significant levels of p53 antibodies, and p53 accumulation was detected in 20 (48%) patients. In six patients, p53 antibody concentrations decreased rapidly after surgery; in two patients, these levels returned to normal values. Of the 10 selected tumors, eight revealed TP53 gene mutations. Only two patients with high values of both CEA and CA 19-9 developed p53 antibodies. In conclusion, beside classical tumor markers, circulating p53 antibodies may be considered as additional markers for the management of patients with colorectal adenocarcinomas.

Experimental studies on unconjugated bilirubin binding by human erythrocytes.

The evaluation of the bilirubin bound to human erythrocytes is considered by some paediatricians as a test to estimate the risk of development of kernicterus. We have studied the physical and chemical characteristics of this binding. Red blood cell membranes contain specific binding sites for bilirubin, the affinity of which is low (Kd = 170 mumol/L). The dissociation constant of the bilirubin/human serum albumin complex is about 10,000 times lower. In jaundiced neonates even with a level of blood bilirubin higher than 300 mumol/l, the binding of bilirubin to red blood cells is negligible. So, the evaluation of the bilirubin bound to human red blood cells does not seem to be a useful test to appreciate the risk of development of kernicterus.

Uroporphyrinogen I synthase assay as an evaluation of the in vitro development of human BFU-E and CFU-E.

We describe a simple spectrophotometric microassay to quantify the proliferation and the differentiation of human bone marrow or blood erythroid progenitor cells CFU-E and BFU-E. These precursors give rise, in culture, to colonies and bursts with markedly variations in size and hemoglobinization, which cannot be accurately evaluated by the usual method of scoring. We then developed a sensitive biochemical microassay to measure the uroporphyrinogen I synthase activity of progenitors grown in small wells. This assay is a valuable index of erythroid differentiation in vitro. This method can offer the opportunity to test the efficiency in vitro of various therapeutic agents in patients with hemopoietic disorders.

[Evidence for one atypic variant of an alkaline phosphatase from human placenta (author's transl)]. / Mise en évidence et purification partielle d'une variante atypique de la phosphatase alcaline placentaire humaine.

A variant of a partially purified Placental Alkaline Phosphatase, showing a slow electrophoretic mobility but the same kinetic caracteristics as the common type, has been found. This variant also differs from the D type by its insensibility to L-leucine inhibition.

Identification of placental alkaline phosphatase in human sera using polyacrylamide gel electrophoresis.

Polyacrylamide gradient gel electrophoresis may be used to separate placental alkaline phosphatase from other types of serum alkaline phosphatase. This method, of which specificity is demonstrated by the thermostability and immunological reaction of the placental form, is sensitive enough to detect an activity of 0.02 mU in a sample, and seems suitable for use in investigating placental isoenzyme in serum.

2,3-2, 3-. / Effets de l'hypoxie sur le métabolisme érythrocytaire du 2,3-diphosphoglycerate chez le lapin soumis a une épreuve d'effort

Erythrocityc variations of glycolytic intermediates and 2,3-DPG levels in rabbits performing strenuous exercise under hypoxic conditions are correlated with blood pH variations. The hypoxia alone is not able to induce directly an increase of erythrocytic 2,3-DPG level which would facilitate tissue oxygenation.