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Biomedical subjects

M Goudemand

Publications and source records attributed to M Goudemand.

At least 73 records · Page 4Linked to original sources

Effect of carbohydrate modifications of factor VIII/von Willebrand factor on binding to platelets.

This study compares the ability of unmodified and carbohydrate-modified forms of factor VIII/von Willebrand factor (FVIII/vWF) protein to bind to platelets in the presence of ristocetin or thrombin. Treatment of intact FVIII/vWF with alpha-D-neuraminidase results in more than 95% desialylation. Asialo FVIII/vWF retains total activity in ristocetin- and thrombin-mediated binding to platelets as demonstrated by direct and competitive binding assays. Examination of its multimeric pattern by sodium dodecyl sulfate-agarose electrophoresis reveals a normal multimeric structure. Treatment of intact FVIII/vWF with beta-D-galactosidase results in the removal of 20% of galactose (agalacto FVIII/vWF) whereas 55% of galactose is released from asialo FVIII/vWF (asialo agalacto FVIII/vWF). Agalacto and asialo-agalacto FVIII/vWF are both unable to bind to platelets in the presence of ristocetin. In contrast, they still bind to thrombin-stimulated human (except thrombasthenic) platelets. Removal of either ultimate (agalacto FVIII/vWF) or ultimate and penultimate (asialo-agalacto FVIII/vWF) galactose results in the same loss of the larger molecular weight multimers and in an increase of smaller multimers. These results suggest (1) that sialic acid does not play a significant role in ristocetin- or thrombin-mediated FVIII/vWF-platelets interactions and multimeric structure of FVIII/vWF (2) that ultimate beta-linked galactose residues are essential for the maintenance of a normal multimer organization (3) that ristocetin- and thrombin-mediated binding of FVIII/vWF to platelets differ in FVIII/vWF galactose requirement.

Aspergillus niger↗

The role of fibronectin in factor VIII/von Willebrand factor cryoprecipitation.

To evaluate the role of fibronectin (Fn) in factor VIII (FVIII) and von Willebrand factor (vWf) cryoprecipitation, factor VIII procoagulant activity, factor VIII coagulant antigen, factor VIII-related antigen and von Willebrand ristocetin cofactor activity were measured in cryoprecipitate and cryosupernatant from normal and Fn-depleted plasmas. Following cryoprecipitation of normal plasmas, most of the FVIII and almost all the FvWf recovered were found with a part of Fn and of fibrinogen in cryoprecipitate. Fn-depleted plasmas prepared either by affinity chromatography on gelatin or by immunoadsorption on monoclonal anti-Fn antibodies behaved differently: although their cryoprecipitate contained normal fibrinogen levels, neither FVIII nor FvWf was precipitated. Experiments performed with Fn-depleted plasma to which purified fibronectin had been added, and samples of plasma with decreased Fn levels (0.01 to 0.2 g/l) suggest that there is a relation between initial Fn level and the extent of FVIII/vWf cryoprecipitation. We conclude that Fn, like fibrinogen, is necessary to induce cryoprecipitation of FVIII/vWf and that an initial plasma level of 0.2 g/l is sufficient to obtain good recovery of FVIII/vWf in cryoprecipitate.

Blood Coagulation Factors↗

[Immunological study of a population of hemophiliacs treated with non-commercial fractions].

We studied lymphocyte subpopulations, serum beta 2 microglobulin, and viral markers in 115 hemophiliacs who are followed and treated at our center. The only clinical or biological anomaly observed is hypergammaglobulinemia. This frequent finding is independent of hemophilia type and of the intensity of substitutive treatment. This group is characterized by the fact that the patients are treated only by locally prepared coagulation fractions, essentially cryoprecipitates for hemophiliacs A, and not containing any derivative of commercial origin. This series is compared to other recent reports, some of which present a high incidence of immunologic anomalies.

Acquired Immunodeficiency Syndrome↗

[Preparation of a specific anti-cytomegalovirus immunoglobulin for intravenous injection].

In the industrialised countries of Europe about 60-70% of adults possess antibodies against cytomegalovirus. Primary infections or exacerbations of a latent infection are in most cases clinically asymptomatic in healthy patients. By way of contrast, attenuations in the immunological defence system: prematureness, pregnancy, the presence of malignant disease, immunosuppressive therapy, as well as massive transfusions of blood, are the commonest causes of a raised incidence of CMV infections often combined with severe clinical overt illness. Because a critical level of antibody is needed to prevent infection and disseminating, we have produced cytomegalovirus hyperimmune globulin for intravenous administration. They are prepared from plasmas of healthy blood donors on the basis of a high antibody level against cytomegalovirus. About 6% are selected by an ELISA procedure. Immunoglobulins, treated to ensure excellent intravenous acceptability, are lyophilized. The final product is found to have an anti-CMV antibody titer of 25 600, by the ELISA test, at a protein concentration of 5%. This CMV-immunoglobulin I.V. has 8 fold higher antibody content than do conventional immunoglobulin preparations. The first trials of prophylaxis and treatment of clinically apparent CMV infections are under study.

Antibodies, Viral↗

[The dexamethasone suppression test in depression. Critical review].

Within the investigation of the neuroendocrinology of depression, the HPA axis exploration brings the most definite results. Biological measurements indicate an hyperactivity of this system in the endogenous depressions. The dexamethasone cortisol suppression test has been described by Liddle and Nugent and has been used by Carroll since 1970. A standardisation of the protocol is required; thus, within the endogenous deficiencies, either lack of cortisol suppression or cortisol suppression with an early escape are noticed. The various and hazardous reasons that make the results vary are discussed. The dexamethasone suppression test is a practical and useful tool for the diagnosis of endogenous depression (sensitivity above 65%, specificity and diagnostical value near 95%); for treatment management; and prognostic evaluation. From a theoretical aspect, the dexamethasone test enables us to delineate the nosology of the depressive disorder and to detect in childhood depression the same neuro-endocrinological features as noticed in adulthood depression. Physiopathological hypotheses within the norepinephrinergic and serotoninergic depression theories are detailed.

Adolescent↗

Structure determination of the major asparagine-linked sugar chain of human factor VIII--von Willebrand factor.

N-glycosidically-linked glycans released by hydrazinolysis of human factor VIII/von Willebrand factor (FVIII/vWf) were separated by high-voltage electrophoresis. Five fractions were obtained, one of them representing 60% of the total amount of the N-glycosidically-linked glycans of FVIII/vWf. On the basis of the carbohydrate composition, methylation analysis and 500 MHz 1H-NMR spectroscopy, we describe the primary structure of this major glycan which is of the monosialylated and monofucosylated biantennary N-acetyllactosaminic type.

Asparagine↗

[Plasma fibronectin].

Fibronectin (FN) is a glycoprotein (disulfite-bonded dimer of 200 to 220 Kd submits) found in a soluble form in blood (concentration 250--500 microg/ml), it can be removed from it by cryoprecipitation and affinity chromatography on gelatin or heparin-agarose. It is also found in an insoluble fibrillar form as a component of connective tissue matrix like collagen, proteoglycans... FN fundamentally forms molecular complexes with collagen, fibrinogen or fibrin, heparin, activated factor XIII, bacteria, cellular membranes..., these various proteins binding with now well known functional "domains" on subunits. Thus FN mediates adhesion of cells to cells as well to biomaterials or tissue, cell migration and chemotactic activity, tissue stromal organization... The transformed cultured cells in presence of oncogen virus loose ability to secrete FN which contribute to their invasive tendency. FN also interacts with hemostatic and fibrinolytic systems, as component of the subendothelium (secreted, like Willbrand factor, by endothelial cells) and of platelet alpha-granules released by stimulated platelets. FN could then provoke platelet spreading on the subendothelium surface after collagen-platelet adhesion, triggered by Willebrand factor, has happened. FN is a part of the fibrinous clot. It participates in anchorage of the clot to subendothelium and mediates its colonisation by fibroblasts, first step to wound reparation. Lastly FN probably has an important role in organism defence. It acts as a non-immunological opsonin, promoting phagocytosis by RES macrophages of bacteria, cellular or fibrin fragments, immune complexes... present in blood. Plasmatic FN concentration is strongly decreased in several ill patients following major trauma, extensive burns, shock, sepsis, with or not evidence of DIVC, of respiratory distress... SABA and various other authors have obtained good results after injections of FN (as cryoprecipitates or concentrated fractions). It is yet necessary to confirm therapeutic role of FN.

Animals↗

[Comparative study of 3 technics for the determination of plasma fibronectin. Results in the normal subject].

Three different techniques (electro-immunodiffusion: EIA, laser nephelemetry and competitive enzymo-assay: CELIA) were compared in order to select an accurate and reproducible assay of plasma fibronectin that could be used in testing large numbers of samples. Nephelemetry, gave results similar to the EIA and CELIA in assays performed with samples from 40 healthy subjects and was used to determine the plasma concentration of fibronectin in 182 male and female blood donors, ranging in age from 18 to 60. The results demonstrate a great variability in plasma fibronectin levels and show that the values are significantly lower in women, 322.9 +/- 94.7 mg/l, compared to 360.8 +/- 97.6 mg/l for men and increase with age. We conclude that the plasma fibronectin levels in various diseases must be interpreted with caution and that it seems more interesting to study the variations of values in comparison with the clinical evolution of the patients.

Adolescent↗

[Immunization with antigen D. Results obtained with 118 volunteers].

During the last four years, 118 blood donors have been immunized to obtain plasma with a high level anti-D in order to prepare anti-D immunoglobulins. The results of the immunizing schedule are very successful, as we have obtained anti-D of titer superior to 256 in 96,36% of the cases (Coombs technic). However, the development of unwanted antibodies outside the Rh system (anti-Jka: 6, anti-Fya: 5) has led us since November 1979 to use phenotyped blood without undesirable red blood cell antigens. No irregular antibody has developed since except for an anti-Yta. The anti-HLA have been observed with a frequency of 36%. The use of frozen/thawed and phenotyped blood without undesirable red blood cell antigens can allow to obtain a high level of anti-D without risk for the donors. Nevertheless, the exceptional immunization to a public antigen persists.

Adult↗

[Anti-HAV-specific immunoglobulins].

The prevalence of anti-HAV antibodies declines dramatically in some European countries because of increasing socio-economical level, leaving the adult population susceptible to HAV infection at a higher age. Therefore an increasing proportion of plasma used for preparation of ISG will not contain anti-HAV. So, it seems to us that preselection of donors is necessary for ISG preparation, in order to reach a satisfactory content of anti-HAV. Firstly, 800 donors above 40 years old were selected and it appeared that ISG prepared was not different from ISG coming out of unselected donors. Titer was 200 UI/ml by RIA method. Secondly, we selected plasmas with high titer of anti-HAV: C 10 greater than 87% by a competitive-inhibition RIA. 498 plasmas among 3 050 tested (16%) were chosen to prepare hyper-immune serum globulin (HISG). In this case, anti-HAV level was 800 UI/ml. In these conditions, it is possible to produce hyperimmune globulin that has a known specific potency against HAV and the future prescription would account anti-HAV level and not merely the volume.

Adolescent↗

[Treatment of hemorrhagic incidents in acute leukemia and bone marrow aplasia. Personal results 1974-1981].

Transfusional therapy regimens have been investigated in a series of 385 patients treated for acute leukemia (AL). During remission induction, fatal hemorrhages occurred in 0.7% of the patients whereas, during the same time, deaths due to infections were four times more frequent. Platelet concentrates (PC) were usually given on the basis of clinical indications. When the risk of hemorrhage was especially high, as during the induction phase of acute promyelocytic leukemia, prophylactic platelet transfusions seemed to be necessary. Alloimmunization developed in 17% to 52% of the patients depending on their cytologic type and in these cases, PC prepared from single donors had to be used. Among the 57 patients with aplastic anemia (AA), bone marrow transplantation was indicated in 17, and 5 of the 10 grafted patients died from hemorrhages. In AA, as the risk of sensitization to platelet alloantigens was higher, PC prepared from single donors were systematically preferred to standard PC. If bone marrow transplantation was planned, PC from histocompatible donors were ordered.

Acute Disease↗

["Lymphoid" blastic transformation in chronic myelogenous leukemia. Report of three cases (author's transl)].

Three cases of chronic myelogenous leukemia (CML) were studied, occurring in 22, 43, and 30-year-old-men. Two observations (nos. 1 and 3) concerned typical CML, treated by discontinuous busulfan; in the last patient (no. 2), also presenting in addition with a constitutional deficiency from Hageman factor, diagnosis (Ph 1 chromosome) was based on a moderate leukocytosis with myelemia, spontaneously regressive for more than one year. Chronic phase duration was 17, 16 and 8 months respectively. During the first blast crisis, abnormal cells were rather of granular type in one case (no 1), undifferentiated in the other two. In the three observations, complete remission was easily obtained with prednisolone - vincristine but revealed very brief; 2, 2 and 4 months. Among the three patients a second blast crisis was preceded, in two cases (nos. 1 et 3), by a new CML phase during 3 and 1 months respectively. Treatment was then purely palliative by 6-mercaptopurine and hydroxyurea.

Adult↗

[Determination of specific anti-HBO immunoglobulin of IgM or IgG type. Relation to other virus HB markers].

A procedure for determining anti-HBc of IgM class is described herein. After IgG anti-HBc antibodies have been preferentially absorbed with Staphylococcus aureus cells positive for protein A, we have tested for residual IgM anti-HBc in the supernatant (absorbed serum) by radioimmunoassay. The occurrence and time course of anti-HBc, studied in 3 patients with ongoing infection, show that IgM anti-HBc persist for about 2 months in cases of acute hepatitis. IgM anti-HBc --marker for a recent HBV infection-- was found to be a useful tool in diagnosis of an unapparent hepatitis with transient or undetectable HBs antigenemia (case no 5). The presence of IgM or IgG anti-HBc, HBeAg and anti-HBe was determined by radioimmunoassay in 68 patients HBsAg positive. The immunoglobulin classes (IgM or IgG) of anti-HBc are dependent on the phase of hepatitis B. Of the 29 IgM anti-HBc positive specimens, 28 were found to be HBeAg positive, 18 of these patients were hemodialysed. 62 among 63 HBsAg positive blood donors had IgG anti-HBc, 6 associated with HBeAg and 56 with anti-HBe. All anti-HBc of anti-HBs positive sera were of IgG class (patients or blood donors). In order to estimate the anti-HBc titer, we have determined the per cent inhibition of 134 HBsAg and 46 anti-HBs positive sera diluted to 1 : 100. We correlate the presence of HBsAg --regardless of the level of titer of it --with high titers of anti-HBc and the presence of anti-HBs with low titers (P less than less than 0,0001). These results are very instructive with regard to the problem of anti-HBc titer and possibility of persisting HBV and we support the hypothesis that HBsAg negative but strongly anti-HBc positive blood might be infectious. IgM anti-HBc are on the average of lower titer than IgG anti-HBc, but we did not observe difference in IgG anti-HBc titer between HBeAg positive sera and anti-HBe, HBsAg positive sera.

Antibodies, Viral↗

[Study of a therapeutic concentrate of factor VIII/vWf prepared in a closed system].

An original procedure of preparation in a closed system of high purity Factor VIII concentrate is presented. Starting from cryoprecipitates, this method involves a first step of partial removal of fibrinogen by glycine precipitation (1.6 M) and a second step of Factor VIII concentration by cryoprecipitation. The yield is 16.5% of plasmatic F VIII:C (0.8 mu/ml.). Several batches of concentrates thus prepared are compared "in vitro" to 9 other commercially available concentrates from 8 different manufactories. The results show that most of the characteristics of our concentrate are within the range of specifications of other commercially available high-purity F VIII concentrate: F VIII: C activity (CRTS Lille concentrate: 25-40 U/ml.; other concentrates: 25-50 U/ml) solubility, specific activity (CRTS lille concentrate; 1.0-1.82 U F VIII:C/mg protein and 1.79-4.8 U F VIII: C/mg clottable proteins; other concentrates: 0.53-2.79 U F VIII:C/mg protein an 1.39-4.84 U F VIII:C/mg clottable proteins), isoagglutinin titers (CRTS Lille concentrate: 2-8 anti-A, 0.16 anti-B; other concentrates: 0-64 anti-A, 8-16 anti-B) F VIIIC/F VIII R: Ag ratios (CRTS Lille concentrate: 0.18-0.49; other concentrates: 0.20-0.42). Furthermore F VIII R:Ag electrophoretic mobility studied by crossed immunoelectrophoresis add F VIII R: RCo assays provide evidence that very high molecular weight multimeric forms of F VIII/vWf which support vWf activity are present in our concentrate. "In vivo" study and clinical efficacy in vWd patients confirm these results and show that our concentrate is appropriate for the treatment of patients with F VIII:C or V VIII R:RCo deficiency.

Blood Coagulation↗