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Biomedical subjects

B Lesourd

Publications and source records attributed to B Lesourd.

14 recordsLinked to original sources

Delayed-type hypersensitivity and circulating basophils. A population study.

The factors related to delayed-type hypersensitivity (DTH) have been investigated in two samples of elderly non-hospitalized (n = 375) and hospitalized subjects (n = 409). Percent basophils was found to be consistently related to the number of positive responses to seven common antigens in the different samples or subsamples considered. The mean number of responses, after adjustment for age, sex and sample was 1.55 below 0.5% basophils, 1.87 between 0.5 and 1.5% and 1.96 over 1.5% (P less than 0.01). No relation was observed between percent basophils and the mean diameter of the positive responses, suggesting that basophils might be related to the early phase of DTH reactions. As previously reported, the number of positive responses was found to be lower in women than in men and to be inversely related to age.

Age Factors

Nutritional status: haematology and albumin. Euronut SENECA investigators.

In the context of the Euronut SENECA study of nutrition and the elderly, performed in 19 towns situated in 12 European countries, blood haemoglobin and haematocrit, and serum albumin were measured in a large sample of 70-75-year-old subjects. The mean haemoglobin (Hb) values for the different towns ranged from 144 g l-1 to 157 g l-1 for men and from 131 g l-1 to 150 g l-1 for women. The town haematocrit (Hct) means ranged from 43.0% to 48.9% for men and from 39.7% to 46.4% for women. No clear geographical pattern emerged for either Hb or Hct. The 95% ranges (2.5-97.5 percentile intervals) for Hb and Hct for all towns combined (without any claim of being representative of Europe) were very similar to those reported in the NHANES II study of the USA. Prevalences of anaemia, using the WHO definition (Hb less than 130 g l-1 for men and Hb less than 120 g l-1 for women) were 5.2% for men and 5.7% for women. The town mean serum albumins ranged from 40.3 g l-1 to 44.3 g l-1 for men and from 40.3 g l-1 to 43.2 g l-1 for women. No clear geographical pattern emerged. Mean values were somewhat lower than for younger adults and comparable to other published data. Most albumin values were in the normal range, with only 2.0% of both men and women having levels below 35 g l-1 and only 0.4% of men and no women having levels below 30 g l-1. These results show that these 70-75-year-old subjects who chose to participate in the study were in relatively good health as judged from their haemoglobin, haematocrit and serum albumin levels.

Age Factors

Prevalence of infections and their risk factors in geriatric institutions: a one-day multicentre survey.

This one-day prevalence survey of 1919 patients (74% females and 44% aged greater than or equal to 85 years) in nine geriatric hospitals, six of them located in France and three in Switzerland, indicated a high prevalence of infections in elderly institutionalized patients (infection rate: 18.7% in males and 15.4% in females). The risk factors for infection were identified and the relative risks assessed. Prevention of infections in geriatric wards should be one of the goals of every care-giver. A low rate of infection in elderly inpatients is thus likely to be associated with care of good quality.

Aged

Hymenoptera venom immunotherapy. I. Induction of T cell-mediated immunity by honeybee venom immunotherapy: relationships with specific antibody responses.

The specific cell-mediated and humoral immune responses of 14 children allergic to honeybee venom were studied. An 8-day rush venom immunotherapy induced an increase in T proliferative (p less than 0.04) and T suppressive (p less than 0.003) cell-specific activities. Antibody variations, an increase in specific IgG4 (p not equal to 0.05), and a decrease in specific IgE (p less than 0.01) were observed 1 year later. Initial high T suppressive cell activity prevents T proliferative cell increase during rush venom immunotherapy. High initial levels of specific IgG1 and specific IgG4 have opposing effects on the increase in T suppressive cell activity, the former being positively correlated with intensive increase (r = 0.840; p less than 0.005), the latter negatively with T suppressive cell increase (r = -0.709; p less than 0.001). These data indicate that there are interrelationships between the cell-mediated immunity and the antibody responses in honeybee allergy.

Adolescent

Hymenoptera venom immunotherapy. II. T proliferative and T suppressive activities induced by Vespula immunotherapy: effects on long-term antibody responses.

Thirty-five children who had exhibited major clinical reactions to yellow jacket stings were desensitized during an 8-day rush immunotherapy (RIT). Maintenance treatment was continued for at least 1 year in all cases and for 2 years in 21 cases. Blood samples, obtained before, during, and after RIT, were analyzed for specific T proliferative (TP) and T suppressive (TS) cell activities and for specific IgE, IgG1, and IgG4 levels. TS and TP cell activities increased during RIT (p less than 0.001) and remained elevated throughout the 2-year follow-up. There were transient rises in specific IgG1 and IgE during RIT, but the levels of both decreased thereafter. Specific IgG4 increased throughout the follow-up period. The data indicate that the levels of specific IgE and specific IgG1 were correlated with TP cell responses (inducers) and TS cells responses (suppressors) and therefore might be controlled by them; data also suggest that TS cell responses should play a role in the IgG4 response. These changes in TS and TP cell responses and antibody responses have been incorporated into a model of antibody-response regulation by cell-mediated immunity in this type of allergy.

Adolescent

[Technics for the study of a total leukocyte dialysate and its fractions].

The crude dialysate extracted from human white blood cells from a thousand unselected donors were studied by leukocyte migration inhibition test with measles antigen. This dialysate and its fractions eluted from Biogel P4 and P6 chromatography were compared towards rosette restoration test and nucleotide composition.

Cell Migration Inhibition

Characterization of human dialyzable transfer factor from normal and chronic lymphoid leukemia sources.

Dialysates of lymphomonocytes can be roughly quantified through the use of optical density and measurements of RNA and protein contents. Dialysates of normal lymphocytes (N-TFd) contain about 224 +/- 67 mug of RNA-like material per 10(8) cells, 75 to 90% of which is eluted in fractions II and III on Biogel P10 chromatography. In contrast, dialysates of lymphocytes from patients suffering chronic lymphoid leukemia (CLL-TFd) contain approximately 12 times less RNA-like material (about 27 +/- 11 mug per 10(8) lymphocytes) and have a different characteristic chromatographic pattern. Bioassays with crude dialysates confirm (a) that N-TFd increases 3H-thymidine incorporation by nonsenstitized lymphocytes "in vitro" in the presence of PPD, and (b) that inbred Lewis rats develop positive skin tests (systemic transfer) after receiving injections of N-TFd or of fractions II and III from Biogel fractionation of N-TFd. Neither test gives positive results when CLL-TFd is used.

Animals

[Production of a dialysable transfer factor of cell mediated immunity by lymphoblastoid cells in continuous proliferation].

Four lymphoblastoid cell lines tested in this work contain normally a dialysable moiety having by ultraviolet spectroscopy, column chromatography (Biogel P 10) and chemically the same properties than human dialysable Transfer Factor (TFd), but unable to transfer cell mediated immune response against common antigens. Two of them are able to do so after incubation with minimal amounts of TFd. Production of a molecule identical to human TFd is possible in some lymphoblastoid cell lines after induction with TFd.

Animals

Respective roles of immune and nutritional factors in the priming of the immune response in the elderly.

Ninety-six institutionalized elderly (greater than 70 years old) (mean age: 82 +/- 7 years) subjects, negative for tetanus toxoid antibodies were primed with tetanus toxoid vaccination and dinitrochlorobenzene (DNCB). Correlations were studied between some immunological parameters, nutritional parameters prior to immunization and the immune response intensity after it. Levels of tetanus toxoid specific IgG (ELISA assay) were positively correlated with monocyte phagocytosis, DNCB response and prealbumin levels, and negatively correlated with total IgG, monocyte immune degradation and tetanus toxoid lymphocyte stimulation. No correlation was observed with IgA, IgM, PHA stimulation. Tetanus toxoid lymphocyte stimulation correlated positively with response to DNCB, and negatively with tetanus toxoid IgG as well as total IgG. DNCB response correlated with prealbumin, tetanus toxoid IgG and tetanus toxoid lymphocyte stimulation. Therefore, it appears that malnutrition, as measured by prealbumin level, is one of the main factors contributing to the inconstant senile immunodeficiency. Monocyte antigenic degradation function unaltered with age can impair immune response while conserved or increased phagocytosis enhances immune response in the elderly. High total IgG levels were linked with low specific responses to priming antigens. High specific antibody levels also correlated negatively with cellular specific response. It is assumed that regulatory IgG antibody accumulation, likely anti-idiotypic antibodies, play an important role in senile immunological depletion.

Aged

[Immune status in infantile autism. Correlation between the immune status, autistic symptoms and levels of serotonin].

In sixteen autistic children high values of IgG and a high level of lymphocyte stimulation with PHA were observed. Principal component analysis showed: 1) a significant correlation between basic lymphocyte mitogenic activity and the clinical symptoms opposition and hyperactivity, 2) a significant correlation between high Ig levels, high PHA stimulation responses and the main autistic symptoms (withdrawal, inaffectivity, hypoactivity, mannerism, stereotypy and negatively echolalia), 3) a significant correlation with serotonin uptake by platelets and high immunological responses. Such correlations are strongly in favor of an immunologic component in autistic disease.

Adolescent