Search PubMed⌕ Search

Biomedical subjects

S E Read

Publications and source records attributed to S E Read.

At least 73 records · Page 4Linked to original sources
PubMed1978

Cellular reactivity to altered glomerular basement membrane in glomerulonephritis.

Glomerular basement membrane may be altered during glomerulonephritis, exposing antigens that are recognized as foreign. Immunochemical studies suggest that removal of peripheral glycopeptides from the basement membrane with glycosidase mimics this pathogenetic event. To examine these hypotheses, we studied 24 patients with biopsy-proved glomerulonephritis by means of the lymphocyte-blast-transformation assay. Three preparations of normal glomerular basement membrane were used: two mimicked the native state for the peripheral glycopeptides, and one was altered by glycosidases. Results showed minimal differences in responses to native glomerular basement-membrane preparations among patients with glomerulonephritis and control groups. However, patients with glomerulonephritis had a significant blastogenic response to the glycosidase-treated glomerular basement membrane as compared to patients with nonglomerular renal disease and normal controls (P less than 0.0005). These studies suggest that cellular reactivity to altered glomerular basement-membrane antigens can be detected in certain forms of progressive glomerulonephritis.

Antigens↗
PubMed1976

Antibody response of rabbit blood lymphocytes in vitro. Kinetics, clone size, and clonotype analysis in response to streptococcal group polysaccharide antigens.

Peripheral blood lymphocytes (PBL) of rabbits previously hyperimmunized against streptococcal groups A and A-variant antigens were stimulated in vitro by the corresponding vaccines to produce group-specific antibody. This response was dependent on an optimal cell density (2 X 10(6) cells/ml), on the presence of antigen, it was specific and cross-reactive due to a shared rhamnose backbone of the two polysaccharide antigens, and it was highly selective, such that in a 42-55-day culture 1 out of 20 viable cells was a specific PFC. During the exponential increase of the antibody concentration at a constant number of PFC, antibodies were secreted at a rate of 2.4 X 10(4) molecules/s per cell until a plateau level of antibody (40 mug/culture) was reached. The microculture system was used to determine the minimal frequency of group polysaccharide-specific precursor cells in the blood. Independent of the time elapsed since the last immunization this frequency was 1-3 X 10(-5), i.e., in the range of 1-2.8 X 10(2) precursor cells per ml blood. This number was further used together with the clonotype analysis of the culture supernates to calculate the frequencies of precursors of major and minor clonotypes. A hierachy of persisting clonal memory precursor cells was found indicating that clonal dominance is determined by locked-in frequency patterns and therefore it is a phenomenon based on numbers of cells that respond to the antigen.

Animals↗
PubMed1974

Cellular reactivity studies to streptococcal antigens. Migration inhibition studies in patients with streptococcal infections and rheumatic fever.

The question of whether hypersensitivity to streptococcal antigens plays a role in the pathogenesis of the nonsuppurative sequelae of streptococcal infections remains at present unclear. As a first step in the approach to this question, the degree of cellular reactivity of peripheral blood leucocytes to streptococcal antigens was investigated in a number of rheumatic fever patients, patients with uncomplicated streptococcal infections, as well as normal healthy subjects. Using the in vitro technique for the inhibition of capillary migration of peripheral blood leucocytes as an index of the degree of sensitivity to streptococcal antigens, the results indicate that patients with acute rheumatic fever exhibit an exaggerated cellular reactivity to these antigens and in particular to streptococcal cell membrane antigens. This abnormal response to streptococcal membrane antigens appears to persist in rheumatic subjects for at least 5 yr after the initial attack of rheumatic fever. Only Group A streptococcal membrane antigens elicited this unusual response in rheumatic subjects, since the cellular reactivity to Group C and D streptococcal membranes was the same in all groups. Patients with evidence of valvular disease exhibited the same degree of cellular reactivity to these antigens as did patients without clinical evidence of rheumatic heart disease. The nature of the antigens responsible for the observed cellular response remains unknown. Enzymatic treatment of streptococcal cell walls and membranes designed to remove type-specific M proteins did not alter the observed cellular reactivity to the streptococcal antigens. The finding that an abnormal cellular response to certain streptococcal antigens is present only in rheumatic patients suggests that cell-mediated factors may play an important role in the disease process.

Animals↗
PubMedDate not supplied

Sexual behaviour changes in a cohort of male sexual contacts of men with HIV disease: a three-year overview.

We describe the sexual behaviour reported by 240 seronegative and seropositive homosexual men over a 3-year period. Sexual partners of men with HIV disease were recruited into a prospective study between July 1984 and July 1985 and were monitored every 3 months thereafter. Data on sexual activities were collected through interviewer-administered questionnaires. The cohort experienced a reduction in both the number of sexual partners and the volume of sexual activity. Reductions in the number of partners were early and dramatic. Changes in sexual activities were gradual and consistent in trend. The greatest reduction occurred in high risk activities (receptive and insertive anal intercourse). After 3 years of follow-up, only 10% of the men continue to be exposed to semen through unprotected receptive anal intercourse and 18% through unprotected receptive oral-genital sex. The proportion of men engaging in oral-genital contact and masturbation remained stable over the 3 years. Once informed of their serostatus, both seropositive and seronegative men reduced their high risk behaviour. The decline in rates of STDs and seroconversion confirmed that this cohort had indeed reduced their high risk behaviour.

Cohort Studies↗