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Biomedical subjects

E M Tan

Publications and source records attributed to E M Tan.

At least 307 records · Page 17Linked to original sources
PubMed1975

Microhemagglutination test for the detection of nucleoprotein antibody in systemic lupus erythematosus.

A simple and practical microhemagglutination test that detects two antibodies, one showing reactivity to the DNA moiety of soluble nucleoprotein (sNP) and the other to the DNA-histone complex of sNP, is described. The method incorporates human erythrocytes formalinized at 30 C., tanned, and coated with sNP at 37 C. Antibody specificity was determined by inhibition experiments performed on sera with added DNA or sNP antigen. With the indirect LE cell technic, evidence that the anti-sNP antibody detected in this work is related to the serum LE factor commonly associated with the LE cell phenomenon was obtained. The hemagglutination test is helpful in establishing the specific diagnosis of systemic lupus erythematosus (SLE) and may be used to follow the course of the disease and response to therapy in SLE patients, as this is a semiquantitative technic and rise or fall in titer or antibody can be determined.

Antibodies↗
PubMed1975

Adjuvant activity of the histamine-sensitizing factor of Bordetella pertussis in different strains of mice.

The effect of an extract of histamine-sensitizing factor (HSF) of Bordetella pertussis on the immune response of different strains of mice to ovalbumin (OA) was investigated with regard to optimal dose of antigen and adjuvant. It was observed that all strains of mice treated with HSF during immunization with OA demonstrated enhanced production of hemagglutinating antibodies, as compared to animals treated with antigen alone. This enhancement was generally not as great as that demonstrated when Al(OH)3 was the adjuvant. HSF also stimulated a reaginic antibody response (IgE) to OA, but not in all strains of mice. In reagin responders optimal responses were observed with high doses of both antigen and adjuvant, whereas low doses of both produced little or no response. Maximal reagin production occurred usually 14-28 days after immunization and persisted for long periods of time. An anamnestic reagin response was elicited upon secondary immunization with antigen alone, not only in mice immunized with OA and HSF but also in animals treated with OA alone. These studies demonstrate the profound effect that a microbial substance such as HSF can have on reaginic antibody production and suggest that the stimulation of IgE antibody production is the net result of a number of factors including genetic capabilities of the host, environmental influence such as adjuvants, and prior exposure to an antigen.

Adjuvants, Immunologic↗
PubMed1975

Antibodies to cellular antigens in Sjögren's syndrome.

An extract of human lymphocytes from continous cell culture was used as the antigen source to detect antibodies in sera of patients with Sjögren's syndrome (SS). Using double diffusion in agarose, 85 per cent of a selected group of patients had precepating antibodies. Three precipitating antigen-antibody systems were detected and were shown to be different from those described previously in othe systemic rheumatic diseases. The SS precipitating antibodies were temporarily classified as precipitins, A, B, and C. SS patinets with sicca syndrome but without clinical rheumatoid arthritis had precipitin systems A and/or B, and SS patients with associated rheumatoid arthritis had precipitin system C. Serum reactants were demonstrated by immuno-electrophoresis to migrate in the gamma globulin region. The precipitating activity of the serum factors was not destroyed by treatment with 2-mercaptoethanol and was not removed by absorption of rheumatoid factor from the sera. The reactivity of the lympuocyte antigens was destroyed by treatment with trypsin but not by deoxyribonuclease or ribonuclease.

Absorption↗
PubMed1975

Profiles of antinuclear antibodies in systemic rheumatic diseases.

The prevalence of different antinuclear antibodies was examined in systemic lupus erythematosus, rheumatoid arthritis, Sjögren's syndrome, progressive systemic sclerosis, dermatomyositis, discoid lupus erythematosus, and mixed connective tissue disease. Antibody to Sm antigen (a nuclear acidic protein) was found almost exclusively in serums of patients with systemic lupus erythematosus, suggesting that this antibody might be a "marker" antibody for this disease. However, antibodies to native DNA and to nuclear ribonucleoprotein were found in a variety of systemic rheumatic diseases. In systemic lupus erythematosus, antibody to native DNA was present in high titer but in other rheumatic diseases in low titer. Antibody to nuclear ribonucleoprotein occurred in certain other systemic rheumatic diseases besides the mixed connective tissue disease syndrome. These studies showed that there were distinct profiles of antinuclear antibodies in certain systemic rheumatic diseases, characterized by the presence or absence of certain antibodies and by differences in their mean titers.

Antibodies, Antinuclear↗
PubMed1975

Provoking factors in bronchial asthma.

Asthmatic patients were identified as having asthma on the basis of lung function studies (76%), objective physical findings of asthma (11%), or a strong history of asthma (13%). Each of the 234 patients so identified was assigned to an asthma subgroup determined by careful clinical assessment of the major provoking factor or factors for his asthmatic episodes; minor provoking factors were also identified. Only 20% of the patients had asthmatic episodes provoked by a single factor. Most asthmatics had at least one major and one or more minor provoking factor(s). Reagin-mediated mechanisms constituted the major provoking factor in 25% of patients and were a minor provoking factor in an additional 20% of the patients. Thus, in only 45% of the patients, were reaginic mechanisms responsible for some part of their asthmatic episodes.

Adolescent↗
PubMed1975

Immunologic and biochemical properties of the histamine-sensitizing factor from Bordetella pertussis.

A highly potent extract of the histamine sensitizing factor (HSF) of Bordetella pertussis was isolated by extraction of bacterial cells with urea buffer and subsequent gel filtration. This preparation of HSF also contained leukocytosis-promoting activity and adjuvant activity for reaginic and hemagglutinating antibodiesl Digestion of this extract with pronase or trypsin partially destroyed histamine-sensitizing activity, leukocytosis-promoting activity, and adjuvant activity for reaginic antibody, but did not affect adjuvant activity for hemagglutinating antibody. Antisera to HSF was prepared by immunizing rabbits with either whole bacteria or partially purfied extract. These antisera contained several precipitating antibodies to Bordetella pertussis extract demonstrated by immunodiffusion and immunoelectrophoresis. Antisera added in vitro to Bordetella pertussis extracts or passively administered in vivo to mice, reduced or abolished all biologic activities except adjuvant activity for hemagglutinating antibody. These results suggest that HSF might be an antigenic component of Bordetella pertussis which also possesses leukocytosis-promoting activity and adjuvant activity for reaginic antibody.

Adjuvants, Immunologic↗