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Biomedical subjects

B Genetet

Publications and source records attributed to B Genetet.

At least 55 records · Page 3Linked to original sources
PubMed1991

A human anti-Jkb monoclonal antibody.

Peripheral blood mononuclear cells of an immunized patient were transformed with Epstein-Barr virus and then fused with P3X63Ag8 mouse myeloma cells by polyethylene glycol. After the cloning, a hybridoma cell line secreting specific anti-Jkb monoclonal antibody was isolated. The antibody was produced in supernatant form and tested for its use as a blood grouping reagent.

Animals↗
PubMed1991

[Improvement of hemorheologic parameters in hemodialyzed patients treated with human recombinant erythropoietin].

Recombinant human erythropoietin (rhu EPO) is the choice treatment of dialytic anemia; however, this therapy has side effects due to the increased number of blood components involved. It seemed to us worth assessing, by hemorheological study, the impact of such a treatment on blood flow properties, already impaired in this type of patients. This study was designed to measure the evolution of hemorheological parameters in 16 hemodialysed patients before and after 2.3 and 6 months of treatment with rhu EPO. Hemorheological work-ups included: erythrocyte filtration with a hemorheometer; blood and plasma viscosities (LS30), ATP and 2.3 DPG, RBC aggregation (Sefam erythroaggregameter), RBC morphology under a scanning electron microscope; blood counts and full biochemical work-ups were performed to explore renal function. The results showed, besides a significant increase in hemoglobin: normalized rigidity index, reflecting the better deformability of erythrocytes; a moderate increase in blood viscosity with uncorrected hematocrit, becoming significant after 6 months of treatment. This increase however did not reach the values that could be expected with the increased hematocrit (it was probably balanced by improved erythrocyte deformability, which is confirmed by the fact that with corrected hematocrit, blood viscosity decreases during treatment). Studying erythrocyte aggregation in hemodialysed patients reveals, in the absence of any treatment, a decrease in aggregation time and a higher dissociation threshold, which reflects a tendency to erythrocyte hyperaggregation enhanced by erythropoietin.(ABSTRACT TRUNCATED AT 250 WORDS)

Anemia↗
PubMed1990

Implication of the HLA-DRB3 gene in Graves' disease: predominance of allele Dw24.

Using RFLP, the present study sets off to determine the MHC class II gene polymorphism in Graves' disease, in order to define the HLA-related genetic susceptibility. Considering the preferential link between Graves' disease and the HLA-DR3 antigen, 42 HLA-DR3 Graves' disease patients were studied and compared with 42 HLA-DR-matched controls. Hybridization with a DQ alpha probe of DNAs digested by Taq I revealed a polymorphism of the DR3 haplotype with an overrepresentation of a 2.1 kb(U) fragment in patients, but this was merely a sign of the linkage disequilibrium between U and B8DR3. Hybridization with the DR beta probe of DNAs digested by Taq I yielded more facts. It revealed the overrepresentation of the Dw24 specificity (Taq I:9.8 kb) in DR3 Graves' disease patients. This study thus enabled us to determine precisely the susceptibility linked to the DR3 haplotype, implicating the DRB3 gene and its Dw24 allele, which appear to be the most reliable markers of the disease, providing a higher relative risk than B8DR3.

Alleles↗
PubMed1990

Antithyroid drugs and Graves' disease: a prospective randomized evaluation of the efficacy of treatment duration.

A prospective randomized study was performed in patients with hyperthyroid Graves' disease (GD) in order to compare long (18 months) and short term (6 months) antithyroid drug treatment on the remission rate. A therapeutic protocol was offered to all GD patients who had not been treated for this disease previously. All patients studied who followed the protocol were rechecked 2 yr after treatment was withdrawn, or earlier in the case of relapse. Of the patients having undergone long term treatment, 61.8% still were in remission 2 yr after treatment withdrawal, whereas only 41.7% of the patients treated for 6 months were in remission (P less than 0.05). Such findings clearly establish that treatment duration has a direct beneficial incidence on the remission rate. These results were confirmed by the fact that treatment for 18 months resulted in remission in 7 of 15 patients who had previously relapsed after a 6-month course of therapy. This improvement in relation to treatment duration might be due to the immunosuppressive action of carbimazole. No significant difference was observed between relapse and remission groups, regardless of treatment duration, for HLA ABDr, serum T3 and T4, and T3/T4 ratio determined before treatment. Only the thyroid-stimulating antibody levels determined at the time of diagnosis and at the end of treatment were higher in the relapse group, a difference that was relevant only globally, due to value scattering. Furthermore, thyroid-stimulating antibody levels at the end of treatment may indicate remission or, conversely, continuance of the pathological process.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Rheologic and cytologic study of autologous blood collected with Cell Saver 4 during cesarean].

Intra-operative autologous transfusion has been frequently used in vascular and traumatic surgery for about ten years. The technique would be justified in other procedures when intra-operative bleeding is significant and the quality of retrieved blood is satisfactory. We have studied the potential use of intra-operative autologous transfusion during caesarean section of 15 parturients. The quality of autologous blood (at different stages of the procedure) was assessed after being recovered and washed by "Cell Saver 4" (Haemonetics). Blood quality was assessed through 1) measuring the following: erythrocyte deformability with Erythrometer and Hemorheometer; blood and plasma viscosities; ATP, 2.3 DPG and plasma hemoglobin rates; and RBC morphology through SEM; 2) bacterial detection and identification; 3) detection of foetal cells which could create immunological disturbances if reinjected into the mother. The results showed: 1) little variation in RBC deformability properties with ATP and 2.3 DPG rates which, apart from a slight decrease, remained within the normal range; 2) a 20 fold increase in plasma hemoglobin persisting, despite successive washes, in 80% of cases; 3) positive Staphylococcus epidermidis hemoculture clinically irrelevant in the reinjectable bag in 90% of cases; 4) close to 1% foetal cells in the reinjectable bag in 20% of cases; 5) 8% abnormal cells as seen on SEM (Stage I echinocytes) and a slight swelling of the RBCs, which could account for their fragility. These preliminary results show that intraoperative autologous transfusion could be used in obstetrical surgery, provided that certain precautions are taken to minimize the aforesaid drawbacks.

Adult↗
PubMed1988

A new immunoreagent for cell labeling. CD3 monoclonal antibody covalently coupled to fluorescent polymethacrylic nanoparticles.

The preparation and application of immunonanospheres are described. CD3 monoclonal antibodies were covalently coupled to fluorescent polymethacrylic nanoparticles by the glutaraldehyde reaction and the resultant conjugate purified by gel filtration on a Sepharose 4B column. Peripheral blood mononuclear cells labeled with this immunoreagent were observed by both fluorescence microscopy and scanning electron microscopy in order to evaluate the technique.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1988

Interferon production in severe hemophiliacs with and without HIV antibodies.

The interferon (IFN) system, both serum IFN levels and the in vitro IFN production, was investigated in 38 clinically asymptomatic multitransfused hemophiliacs, half positive and half negative for HIV antibodies. In most patients, no circulating IFN was detected; similar levels of IFN-alpha were obtained after peripheral blood mononuclear cell (PBMC) stimulation with Sendai virus both in hemophiliacs and controls, while production of IFN-gamma following stimulation with phytohemagglutin (PHA) was diminished in a large number of patients irrespective of their HIV serology. These data indicate that the deficiency in IFN-gamma generation is not only related to HIV contamination but may be a direct consequence of the chronic antigenic stimulation through Factor VIII concentrates.

HIV Seropositivity↗
PubMed1988

Definition of DRw10 specificity by restriction fragment length polymorphism.

The purpose of this study was the RFLP characterization of the DRw10 specificity. Twenty-two DRw10 cells were tested: the DNAs were digested by seven restriction enzymes and hybridized with DR beta, DQ beta and DQ alpha probes. Hybridization with DR beta revealed a pattern particular to the DRw10 specificity, with a specific TaqI 12.5Kb fragment. Hybridization with both DQ-specific probes showed that DRw10 is always associated with a special DQw1 subtype: DQw5. Furthermore, at DR and DQ levels, the 22 DRw10 cells behaved homogeneously.

Alleles↗
PubMed1988

[Increase of the frequency of HLA DR4 antigens in recurrent arterial hypertension of pregnancy].

We studied the frequency of HLA DR antigens in 96 women whose 50 with preeclampsia (PE = proteinuria greater than 0.5 g/l + HTA) and 46 with gestational HTA (GHTA = pregnancy-induced HTA without proteinuria). Sixty had later pregnancies (28 PE and 32 GHTA) and were followed for from 3 to 23 years (m = 8.5 yrs) after the first pregnancy. HLA DR antigen distribution was determined by a search on B lymphocytes for the 10 antigens of locus DR. The normal population included 38 control couples (76 mothers and fathers) with normotensive pregnancies (A) and 200 healthy controls recruited from a local blood donor population (B). The frequency of alleles was compared to that of the different group of primiparous women and whole group of women with later pregnancies. Significant variations were evaluated by the chi 2 test, using Woolf's method: the p values obtained was multiplied by the number of antigens looked for (p corrected or pc). Only the DR4 antigen, present in 19.7% of control couples (A) and 26.5% of the blood donor population (B), was increased in proportions that depended on clinical classification: 54.3% (pc less than 0.005 with A, less than 0.007 with B) in all primiparous women with GHTA, 38% (NS) in all primiparous women with PE. However significant variation was also observed when the frequency of DR4 in PE women was compared to that in only women of A (38% vs 5.2%, pc less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1988

[Evaluation of the activity of leukocytes during experimental periodontitis in the monkey].

Polymorphonuclear leucocytes play an important role in the defense mechanisms and destruction of periodontal tissues. The leucocytes number and activity were compared during an induced periodontitis in 3 Cercopithecus cephus. On day 0, the 3 animals presented a localized marginal gingivitis. On 2 animals a severe marginal periodontitis was induced unilaterally: 42 days later leucocytes were sampled in the peripheral blood, in the gingival blood and in the gingival sulcus on the experimental and control sites as well as on the 2 hemijaws of the control animal. For each sample, a leucocyte count and a chemiluminescence test were done. Different results related to the disease severity were obtained with these tests for gingival blood and sulcular fluid.

Animals↗
PubMed1987

Flow cytometric quantitative evaluation of phagocytosis by human mononuclear and polymorphonuclear cells using fluorescent nanoparticles.

The use of fluorescent polymethacrylic nanoparticles (0.3 micron) as a flow cytometric reagent in the quantitative evaluation of phagocytosis by human mononuclear and polymorphonuclear cells is described. The preparation of the nanoparticles, by emulsion copolymerization of methacrylic monomers, and their physicochemical properties are briefly summarized. Nanoparticles coupled with a fluorescent agent (ethidium bromide) were used in a flow cytometric assay to study opsonin-independent phagocytosis by human polymorphonuclear cells and by human monocytes. The phagocytosis of nanospheres by monocytes was determined by flow cytometry from the fluorescence distribution and ingestion was visualized by scanning and transmission electron microscopy. One possible application of the fluorescent nanoparticles is the simultaneous analysis of cell surface antigens and cell phagocytic activity.

Acrylates↗
PubMed1987

A common epitope between HLA-B27, -B13 and -B37 alloantigens defined by a monoclonal antibody.

An anti-HLA-B27 monoclonal antibody produced by the hybridoma technique is described. This BD.7 reagent is a cytotoxic IgM antibody. Its reactivity was studied by lymphocytotoxicity tests, indirect immunofluorescence tests and biochemical analysis against an extensive panel of peripheral blood mononuclear cells. All HLA-B27 positive samples, either from normal subjects or from patients with Ankylosing Spondylitis, were recognized by this reagent. Moreover, a cross-reaction was observed with HLA-B13 cells, and a new unexpected reaction with all HLA-B37 cell suspensions. The interest of such a reagent is discussed.

Antibodies, Monoclonal↗