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Biomedical subjects

M Desrosiers

Publications and source records attributed to M Desrosiers.

9 recordsLinked to original sources
PubMed1991

The large vestibular aqueduct syndrome and sensorineural hearing loss in the pediatric population.

Sensorineural hearing loss, associated with a dilated vestibular aqueduct, is often described as progressive. Since 1982, computed tomography of the mastoids has become part of the routine investigation of deaf children at Sainte-Justine Hospital. Using clinical, audiometric and radiological material from 130 patients with sensorineural hearing loss, we identified 18 patients with enlarged vestibular aqueducts. The large vestibular aqueduct population was then compared to the normal vestibular aqueduct patients in regard to the degree and evolution of the sensorineural hearing loss. Progression of hearing loss was noted in 46% of patients in the presence of large vestibular aqueducts as compared to 35% in the absence of this anomaly. Normal radiographic findings did not exclude the possibility of further hearing loss.

Child↗
PubMed1990

Evaluation of biotinylated DNA probes for the detection of gene rearrangements in clinical specimens.

To determine whether a nonisotopic procedure is suitable for analyzing clinical specimens for gene rearrangements, the authors hybridized DNA from 15 specimens of lymphoid tissue with biotinylated DNA probes directed to J beta I + J beta II (T-cell receptor beta chain gene), JH (immunoglobulin gene heavy chain J region), and J kappa (immunoglobulin gene kappa light chain J region). Five cases of benign lymphoid hyperplasia, one case of dermatopathic lymphadenopathy, and one case of small noncleaved follicular center cell lymphoma had germline hybridization patterns when digested with Bam HI, Eco RI, and Hind III restriction endonucleases. Four cases of B-cell lymphoma and three cases of T-cell lymphoma had clearly detectable rearrangements of the genes for immunoglobulin or the T-cell receptor or both. One case of dermatopathic lymphadenopathy had a faint, clonal rearrangement of the T-cell receptor after digestion with Eco RI and Bam III. The authors conclude that biotinylated DNA probes can be useful for analyzing gene rearrangements in clinical specimens.

Biotin↗
PubMed1990

Anti-HIV antibodies and other serological and immunological parameters among normal Haitians in Montreal.

A matched-pair, cross-sectional study of lymphocyte and serological parameters associated with acquired immune deficiency syndrome (AIDS) in 189 randomly chosen, ostensibly healthy adult Haitian immigrants residing in Montreal matched for sex, age (within 5 years), and neighborhood of residence to 189 non-Haitian (Caucasian) controls was done in 1983-1984. Three years later (1986-1987), 41 of the Haitian study subjects and 83 of the non-Haitian controls participated in a follow-up study centered on lymphocyte parameters. A significantly greater number of Haitians than controls had produced antibodies to Toxoplasma gondii. In addition, a greater percentage of the Haitians than the controls were also producing antibodies to two other opportunistic pathogens frequently encountered in AIDS, cytomegalovirus and hepatitis B virus, implying that the Haitians in general had had greater exposure to a variety of infectious agents than had the controls. A few study participants were producing antibodies against two viruses that are related to the human immunodeficiency virus-type 1 (HIV-1), the human T-cell lymphotropic viruses I and II (HTLV-I and -II). Two Haitians and one control were producing antibodies against HTLV-I. One study subject and four controls were HTLV-II seropositive. The most interesting and surprising finding was that four (2.1%) of the Haitian study subjects but none of the controls were seropositive for HIV-1. These individuals, two of whom were women and two men, were asymptomatic. Although their individual lymphocyte parameter values fell in the normal range, as a group they had statistically significantly lower average values for their lymphocyte parameters than did the HIV-seronegative Haitian study objects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Tac expression induced by Epstein-Barr virus is restricted on non-transformable B lymphocytes.

During the course of a comparative study dealing with the immortalization of lymphocytes from a large number of normal healthy donors, we found that B cells of two of these individuals could not be immortalized by Epstein-Barr virus (EBV) under the standard conditions. The expression of the Tac antigen on the membrane of EBV-infected B cells from these two donors was compared with that of B cells from EBV immortalization-susceptible ones. The method used was two-colour immunofluorescence cytofluorometer analysis. We found that the Tac antigen expression was significantly and repeatedly reduced in the case of the two immortalization-resistant donors. This difference might be related to a genetic control of the resistance to EBV-immortalization.

B-Lymphocytes↗
PubMed1985

Immunologic findings in healthy Haitians in Montreal.

To investigate the occurrence of acquired immune deficiency syndrome in Haitians, a health status questionnaire was administered and selected studies of immune status done in a randomly chosen sample of 189 healthy adult Haitians living in Montreal. The study group was comparable to a large sample of Haitians in Montreal interviewed in the 1981 census with respect to age, sex, number of persons per household and year of immigration, but the proportion of currently married people in the study was larger (60.8% v. 42.6%). The results in the study group were compared with those in a sample of 189 non-Haitians matched for age, sex and neighbourhood of residence. Persons with known causes of impaired immune function were excluded. The participation rate was 87.5%. The study and control groups both reported few symptoms and chronic health problems and had comparable demographic data, including rate of employment and income. The mean total numbers of lymphocytes, OKT3 and OKT4 (helper) and OKT8 (suppressor) cells were significantly higher in the Haitians than in the controls, though still within normal limits. There was a borderline elevation of the lymphocyte response to phytohemagglutinin in the Haitians. The ratios of helper to suppressor T cells in the two groups were, however, not significantly different. The Haitians, in comparison with non-Haitians living in the same community, had no demonstrable abnormalities of cellular immune function.

Acquired Immunodeficiency Syndrome↗
PubMed1976

Immunological features in multiple sclerosis.

A clinical and laboratory profile of the immunological system of patients with multiple sclerosis (MS) strongly suggested that many specific immune deficiencies exist in MS. The immunological history showed that patients with MS had had more tonsillectomies, appendicectomies, and childhood infections than matched controls, which suggested that there had been problems in controlling various types of childhood infections. The cell-mediated immune response and the circulating antibody titres were specifically impaired against a variety of antigens. Patients with MS had significantly lower serum antibody titres than controls against many naturally occurring antigens-namely, diptheria and tetanus toxoids, adenovirus, and mumps viruses. Raised serum antibody titres were found against measles and varicella zoster viruses while no difference was found towards other antigens. The delayed hypersensitivity reaction and the immunological memory of patients with MS were also greatly reduced against the mumps skin test antigens. There were normal amounts of circulating T and B lymphocytes, and the phytohaemagglutinin, concanavallin A, pokeweed mitogen, and encephalitogens lymphocyte transformation was not different from that in controls. These results indicated that patients with MS have more infectious problems than normal people and that both their T and B cell systems cannot mount a fully normal immunological response to some viral and bacterial antigens, while they give an increased response to others.

Adult↗
PubMedDate not supplied

Stimulation of T cells and induction of interferon by toxic shock syndrome toxin 1.

Toxic shock syndrome toxin 1 (TSST-1) is a potent immunomodulating substance isolated from Staphylococcus aureus strains associated with toxic shock syndrome (TSS). Flow cytometric analysis was used to compare scatter changes in several cell-surface phenotype markers on human mononuclear cells exposed in vitro to TSST-1 or to phytohemagglutinin, a lectin with similar effects on the immune response. The results showed differences between PHA and TSST-1 in the appearance of the tested T cell subset markers and of interleukin 2 receptors. In general, the stimulation of mononuclear cells by TSST-1 was slower than that by phytohemagglutinin. TSST-1 induced the production of interferon in cultures of murine spleen cells. By means of inhibition studies with specific antibodies to interferon, the interferon produced was characterized as the gamma type. Human mononuclear cells exposed to the toxin also produced gamma interferon, with levels similar to those induced by staphylococcal enterotoxin A, a known potent interferon inducer. The induction of gamma interferon by TSST-1 may play a role in the immunosuppression caused by TSST-1.

Adult↗