[Comparison of thawing of plasma by microwave or water bath: preliminary longitudinal biological study of hemostatic parameters].

Exploration of haemostasis was performed on plasmas thawed in an experimental microwave oven comparatively to a 37 degrees C water bath. Factor VIII:R:Ag, procoagulant and antigenic fibrinogen, and Fg:C/Fg:Ag ratio were found to be significantly, slightly decreased with microwave thawing. Factor VIII:C and VIII:C/VIII:R:Ag ratio were found to be increased with microwaves.

Studies on the structural requirements of heparin for the catalysis of thrombin inhibition by heparin cofactor II.

The structural requirements of heparin for the catalysis of thrombin inhibition by heparin cofactor II (HC II) were investigated. A series of well characterized heparin derivatives were prepared and their activities were measured using human thrombin in the presence of an excess of purified human HC II and, for comparison, antithrombin III (AT III). The 50% inhibitory concentrations of each derivative were calculated and compared with those of unmodified heparin.

An antiserum identifying a red cell determinant expressed by Rh:33 and by some "new" depressed Rh phenotypes.

An antibody detecting a determinant on Rh:33 cells and cells with depressed C and/or e antigens was separated by the absorption and elution technique from a serum with antibodies to several low-frequency antigens. The determinant, tentatively named FPTT, has a frequency of about 0.0094 percent in the South of France.

[Sero-epidemiology of viral hepatitis A, B and delta in Martinique].

In view of the ethnic and geographical peculiarities of the French department of Martinique and of the endemic character of hepatitis in tropical countries, we studied the prevalence of infections with hepatitis A, B and delta viruses in that region. A group of 10,109 blood donors and a group of about 100 patients were selected on account of their liver symptoms. As regards hepatitis A, the study of the 2 groups was completed by a sero-epidemiological survey of 509 children and teenagers aged from 1 to 18 years.

[Infections and bone marrow autograft carried out for leukemias in children. Apropos of 47 cases].

This study included 44 children undergoing autologous marrow transplantation for leukemia between August 1979 and June 1987. Three of them received a second transplant. In the phase of neutropenia, 38 children presented with fever.

Pharmacokinetics of dermatan sulfate in the rabbit after intravenous injection.

To investigate the pharmacokinetic properties of dermatan sulfate (DS), a new potential antithrombotic agent, two different approaches were used. In the first one, DS was derivatized with 3-4 hydroxyphenyl propionic acid N hydroxysuccinimide ester (SHPP) and iodinated. The labelled derivative was injected by IV route to rabbits with increasing doses of unlabelled compound ranging from 20 to 4000 micrograms/kg.

Standard heparin enhances the antithrombotic activity of dermatan sulfate in the rabbit but CY 216 does not.

Standard heparin (SH) and dermatan sulfate (DS) two glycosaminoglycans with different pharmacological targets are effective antithrombotic agents in the rabbit. We have investigated the antithrombotic activity of the association DS plus SH. It was found that doses as low as 25 micrograms/kg for DS and 10 micrograms/kg for SH were ineffective when injected separately but generated a high and significant antithrombotic activity when injected together.

[Probable association of HLA-DR5 with bullous pemphigoid].

HLA typing was performed in 35 French Caucasoids with bullous pemphigoid and compared with 160 healthy controls. 47 HLA antigens were characterized by a lymphocytotoxicity micromethod. Analysis of the results only reveals one statistically significant difference: an increased incidence of HLA-DR5, which reaches 51.

Genetic polymorphism of alpha 2HS-glycoprotein in a French population. Description of two new rare variants.

A French population was investigated for genetic polymorphism of alpha 2HS-glycoprotein (A2HS; nomenclature according to Human Gene Mapping 7, Los Angeles, 1983) using isoelectric focusing and immunoblotting. Three variants were observed together with two common alleles A2HS 1 and A2HS 2, whose frequencies were significantly different from the data in Canadians and Egyptians. An anodal variant to A2HS 1 was identical to a variant with two different nomenclatures reported by three different groups, indicating that there is a confusion in the A2HS nomenclature.

Human castor bean allergy and HLA-A, B, C, DR.

Our results in 27 castor bean-allergic patients typed for HLA-A, B, C, DR antigens show (although the observed difference did not reach a statistical significance after correction for the number of tested specificities) an increase of A2 cross-reacting group antigens and, on the other hand, of HLA-A29, B39, CW2, B12, DR2, and especially DR5 (48.1% vs. 26.

[The place of immunology in recurring spontaneous abortion].

Spontaneous repeated miscarriages are often explained by an immunological mechanism. Whereas in normal pregnancy the mother develops a tolerance immune response induced by paternal antigens of fetus, she is unable to react in this variety of miscarriage. The immunological theory is supported by some solid experimental arguments, which are detailed.

[Robertsonian translocation and genetic counseling].

A collaborative study on 92 Robertsonian translocations is analysed in relation with the methods of ascertainment, the type of rearrangement and potential imbalance of the anomaly. The results are useful in genetic counselling.

The role of the hematocrit in bleeding.

Low hematocrit is an often neglected cause in the pathogenesis of a prolonged bleeding time in an anemic patient. There has been ample evidence in the literature, indicating a relationship between hematocrit and the bleeding time; and that the transfusion of RBCs may correct the prolonged bleeding time often observed in anemic patients. It is unclear how a low hematocrit causes a prolongation in the bleeding time; however, two hypotheses have been put forward.

[Functional adjuvant for stored red blood cells: ascorbate or oxalate?].

In stored blood cells the p50 and the 2,3-DPG concentration drop rapidly. To compensate the functional resultant weakness, many different additives have been proposed, in particular ascorbate, which is very unstable, and ascorbate-2-phosphate (AsP), which is a little more stable. We have studied the effect of two commercially available AsP whose impurity content was different.

[24-hour study of thawed erythrocytes. Value of a protective solution].

We have previously shown that thawed RBC concentrate can be stored at +4 degrees C during 9 days if resuspended in a synthetic medium: ESOC. We now report the in vitro evolution of thawed RBC stored with or without protective medium during the 24 hours legal time-limit. (Formula: see text) We show that without protection, the ATP and 2,3-DPG levels remain acceptable, but spontaneous or caused hemolysis is high.

Inactivation of heparin cofactor II by polymorphonuclear leukocytes.

Inactivation of purified human heparin cofactor II by polymorphonuclear leukocytes was investigated. A proteolytic mechanism of inactivation was demonstrated by SDS-polyacrylamide gel electrophoresis. Inactivation and related proteolysis did not occur in the presence of unstimulated leukocytes and were prevented by various protease inhibitors.

Antithrombotic and bleeding effects of a new synthetic direct thrombin inhibitor and of standard heparin in the rabbit.

This study reports on the anticoagulant, antithrombotic and bleeding effects of a new synthetic direct thrombin inhibitor (SDTI) in comparison with standard heparin (SH). The anticoagulant effect was determined with the thrombin clotting time (TCT) and the activated partial thromboplastin time (APTT). SDTI was more potent than SH in prolonging the TCT, but as potent as SH in prolonging the APTT.

HLA class I antigens on normal and leukemic cells (quantitative analysis).

A monomorphic anti-Class I monoclonal antibody, ST01, found in our laboratory, was used to quantify Class I antigens on normal and leukemic cells, using a "CELISA" technique. Saturation graphs were used to compare the quantity of Class I antigens on normal PBL (25 cases) with that on the following types of leukemic cells: a) common acute lymphoblastic leukemias (cALL) (11 cases), b) mature B lymphocytic proliferations (16 cases), c) T hemopathies (9 cases), d) non-lymphoid leukemias (9 cases). In most cases the quantity of HLA Class I antigens was greatly reduced.

Human autoimmune serum antibodies against gag gene p30 retroviral protein also react with a U1-SnRNP 68K comigrant protein.

Using Immunoblotting procedure, we showed that autoimmune human antibodies reacting with mouse retrovirus gag-p30 also reacted with a HnRNP 68 Kd protein. Since U1-SnRNP 68 K and p30-gag proteins show 40% homology, the detected 68 Kd protein is likely to be the U1-RNA 68 K.