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Biomedical subjects

B Dupont

Publications and source records attributed to B Dupont.

At least 505 records · Page 28Linked to original sources
PubMed1976

Linkage of gene for C2 deficiency and the major histocompatibility complex MHC in man. Family study of a further case.

Close linkage between HL-A and C2 deficiency was first reported by FU and co-workers in 1974. We present here a pedigree of a 31-year-old C2-deficient individual with clinical manifestations of Hodgkins disease. The following markers were tested: C2 levels, factor B polymorphism, blood groups, and enzyme typing. In addition to close linkage between HL-A and C2 deficiency, both parents were heterozygous for Bf (HL-A linked, electrophoretic variation of B). The two HL-A haplotypes closely linked to C2 deficiency are different: 2, W18 and W24, W18. They share, however, the SD2 antigen W18 and the LD type 7a.

Adult↗
PubMed1976

The use of cryopreserved lymphocytes for longitudinal studies of immune function and enumeration of subpopulations.

The responses of fresh and frozen lymphocytes to mitogens and antigens have been compared using samples collected on five separate occasions from one normal donor. The day-to-day variation seen with the fresh cells was eliminated by the use of frozen cells. Thawed cells from one donor collected on one occasion but studied on five separate occasions and compared to fresh cells on the same days, showed fluctuations from day to day as well, confirming that the day-to-day variation seen is due to technical and not biological phenomena. Cryopreserved cells showed a decrease in responses to specific microbial antigens, a slight shift in the PHA dose-response curve, but no significant difference in responses to Con A or PWM. The relative proportion of lymphocyte subpopulations changed with freezing and thawing. The proportion of T cells increased slightly and the proportion of B cells decreased.

Antigens, Bacterial↗
PubMed1976

Leukocyte migration inhibitory factor (LMIF) production in unidirectional mixed lymphocyte cultures.

Puromycin treatment of lymphocytes was used to develop a one-way test for leukocyte migration inhibitory factor (LMIF) production in the mixed lymphocyte culture (MLC) reaction. Lymphocytes incubated with this protein synthesis inhibitor induced a vigorous mediator production by nontreated allogeneic cells, being themselves unable to respond to stimulator cells. When puromycin-treated cells were stimulated with the mitogens PHA, ConA, or PWM, overall protein and DNA synthesis were significantly decreased with concomitant abolishment of LMIF production. Viability of stimulator lymphocytes was found to be essential for generation of the mediator in MLC reaction.

Cell Survival↗
PubMed1976

[Fungal and parasitic infections during immunosupressive treatment (author's transl)].

Deep visceral fungus infections, induced by occasional pathogens, have caused a new class of diseases, and occupy a more and more important place among the complications due to immunosuppressive agents. The experience of the Mycology Unit of the Pasteur Institute, where recent techniques of mycological and immunological diagnosis of these fungus infections are used, is reported here. 24 patients submitted to corticosteroids and other immunosuppressive treatments, including 6 renal transplants and one liver transplant, developed deep visceral infection with septicemia due to Candida, in a series of 106 cases of deep candidiasis due to massive antibiotic treatment diagnosed over the last few years. The mycological, immunological and therapeutic data obtained after treatment with amphotericin B and 5-fluorocytosine are reported here. 8 cases of meningeal, pulmonary and bony and cutaneous cryptococcosis, occurring after corticotherapy (6 cases), radiotherapy (1 case) and renal transplantation (one case), are presented together with the favourable results (6 cures out of 8) obtained with amphotericin B and 5-fluorocytosine, eight alone or in association. The authors also report 2 cases of aspergillosis, one in the lung, occurring in a case of renal transplantation who was given, at an early stage, amphotericin B and 5-fluorocytosine, thanks to rapid laboratory diagnosis, and another case in a heart transplant with pulmonary and cerebral localisations from which the patient died. The literature on these fungus infections, together with the mucormycoses, nocardioses and other fungus and antinomycosal complications are reported, together with parasitic infections the severity of which is emphasized in renal transplants, in particular P. carinii pneumonia, toxoplasmosis, strongyloidiasis and other parasitic diseases.

Adolescent↗
PubMed1976

Leukocyte migration inhibitory factor (LMIF) profile in primary and secondary immunodeficiency disease.

Lymphocytes from patients with primary and secondary immunodeficiency disease were tested for capacity to produce LMIF after mitogen and antigen stimulation as well as for ability to stimulate and respond in unidirectional MLC-LMIF assay. Different patterns of immune abnormality in vitro were detectable when Con A and Candida albicans antigen were used. In addition, significant abnormalities in LMIF responding and stimulatory capacity were demonstrated in patients with Hodgkin's disease. LMIF production after stimulation with different agents allows for a better characterization of cellular defects in immunodeficiency disease.

Antigens, Fungal↗
PubMed1975

Mixed lymphocyte culture determinants and C2 deficiency: LD-7a associated with C2 deficiency in four families.

Four families with C2 deficiency were studied. Among eight HL-A haplotypes involved with C2 deficiency, five were HL-A 10,W18. Three homozygotes for C2 deficiency from different families were mutually nonreactive in mixed lymphocyte cultures (MLC) and the heterozygotes from the fourth family failed to react to the homozygous cells. It appeared that identical MLC determinants were associated with all the genes from the different families that related to C2 deficiency. Further experiments identified the MLC determinant, LD-7a, as being involved. These results suggest marked linkage disequilibrium between the genes for C2 deficiency and the major histocompatibility complex (MHC). Studies of possible recombinants have offered tentative evidence for the positioning of the locus for C2 deficiency with respect to other segments of the MHC.

Chromosome Mapping↗
PubMed1975

Hereditary C2 deficiency: Genetic studies and association with the HL-A system.

Herediatary C2-deficiency has been shown to be transmitted asn an autosomal recessive characteristic. Recent evidence indicates that some genetic factors involved in the control of the complement (C) system in both man and mice are governed by genes localized within the major histocompatibility regionmthis study describes a large pedigree of the paternal family of a C2-deficient patient with systemic lupus erythematosusl It is shown that this condition is transmitted as an autosomal recessive trait, the heterozygous carriers having approximately half normal levels of C2. Furthermore, this trait was shown to be inherited in close linkage with an infrequent HL-A typw, 2,4A2. The maternal, C2-defective chromosome was shown to be transmitted by HL-AW10, W18 haplotypemthis same haplotype was described in a similar study by Fu et al. (6) to be associated with C2 deficiencymfinally, a third haplotype HL-A2,W18 carrying a defective C2 gene was demonstrated in a part of this pedigree.

Complement C2↗
PubMed1975

Recognition by pregnancy serums of non-HL-A alloantigens selectively expressed on B lymphocytes.

A group of alloantibodies are found in pregnancy sera which react with antigens present on B lymphocytes and monocytes but are not detectable on the vast majority of unstimulated T cells. This specificity distinguishes them from HL-A antibodies which react with both cell types. They were readily recognized through indirect fluorescent antibody analysis by employing the combination of B-cell lymphoid lines and normal peripheral blood T cells. Different sera gave a variety of patterns of reactivity with a panel of 11 lymphoid lines. Similar differential patterns were also observed with normal B cells from different individuals particularly after concentrating the B cells. The antibodies were also cytotoxic to B cells and this procedure gave parallel results to the fluorescence method. The pattern of reactions obtained indicated a very heterogeneous system similar to that for HL-A. Special study of certain of the sera provided evidence that the lymphocyte-defined determinants of the mixed lymphocyte reaction system were involved. For convenience the term HL-B has been employed for these antigens.

Antibody Specificity↗
PubMed1975

Evidence for tryosine peptide homologies in the HLA antigens system.

The tetrameric HLA antigens are composed of two heavier chains which carry the alloantigenic determinants and two lighter chains identified as beta2-microglobulin. Although at least 40 different antisera are required to define the varying HLA specificities, it appears that these antigens may be closely related to each other and to the immunoglobulins. Through the use of a new electrophoretic technique, which is able to compare simultaneously the tyrosine peptides produced from radioiodinated cell surface proteins, this report gives evidence that HLA antigens of the three chromosomal loci may have similar amino-acid sequences. Since the retention of homologous tyrosine residues and a tendency for sequence preservation surrounding these residues are features of immunoglobulin structure, this may indicate that similarly conservative evolutionary mechanisms have been operative in the HLA allelelic proteins or that immunoglobulins and HLA antigens may indeed have a common evolutionary origin.

Antigen-Antibody Reactions↗
PubMed1975

Leukocyte migration inhibitory factor (LMIF) induced by concanavalin A: standardized microassay for production in vitro.

A standardized microculture system has been developed to assess the ability of lymphocytes to secrete leukocyte migration inhibitory factor (LMIF) in response to the nonspecific mitogen concanavalin(Con A). LMIF-rich supernates collected from stimulated lymphocytes cultured in plastic microtiter plates are assayed by pulse exposure of purified human granulocytes and inhibition of their migration in agarose medium. LMIF activity in this system is suppressed by the protein synthesis inhibitor puromycin, but not by inhibition of lymphocyte proliferation by irradiation. It is demonstrated that normal lymphocytes stimulated with mitogen elaborate LMIF activity, while lymphocytes from malignant lymphoma patients are frequently unable to produce it. Thus, mitogen-induced mediator production may be a useful parameter in further characterization of primary and secondary immunodeficiencies.

Cell Migration Inhibition↗
PubMed1975

Detection of measles antibodies in cerebrospinal fluid and serum by a radioimmunoassay.

Evidence that different structural components of the measles virus may act as antigens has been provided by the serologic methods of hemagglutination inhibition hemolysin inhibition, and nucleocapsid complement fixation. Using radioiodinated measles viral antigens, and immune precipitation assay has been designed that is capable of discriminating among various reactivities to measles viral structural components in serum or cerebrospinal fluid (CSF) and of distinguishing whether IgG and IgM antibody is involved. This technique has been applied to the study of measles antibodies in CSF and sera of patients with multiple sclerosis (MS) and other neurologic diseases. From data presented here, it was found that both groups of patients have individual reactivity to measles proteins, present in CSF and serum, whereas three normal CSF samples were found not to have such antibodies. It appears that oligoclonal immunoglobulins in CSF of MS patients may be detected by this method, and one patient with MS was found to have CSF IgM anti-measles antibodies.

Antibodies, Viral↗