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Biomedical subjects

J J Thompson

Publications and source records attributed to J J Thompson.

At least 55 records · Page 3Linked to original sources
PubMed1982

Use of monoclonal antibodies in detection of melanoma-associated antigens in intact human tumors.

The use of antimelanoma monoclonal antibodies on tissue sections using a two-step indirect immunoperoxidase technique is reported. Antibodies 691-13-17 and 691-I5-Nu4B reacted with dysplastic nevus cells and all melanomas tested, but not with normal skin melanocytes, intradermal nevi, or lentigines. Antibody 691-13-17, directed against DR antigen, reacted also with Langerhan's cells, macrophages, and a subpopulation of lymphocytes. Antibody 691-I5-Nu4B reacted only with melanomas. The technique allows analysis of the expression of antigens by tumor cells in situ.

Adult↗
PubMed1981

Adenocarcinoid tumor of the colon arising in preexisting ulcerative colitis.

Patients with ulcerative colitis are at increased risk of developing adenocarcinoma of the colon. The authors describe a patient whose colonic neoplasm demonstrated histologic characteristics of both an adenocarcinoma and a carcinoid tumor and which was pathologically identical to a appendiceal adenocarcinoid. Because individual tumor cells stained positively for both mucin and argentaffin granules, the histologic picture is unique among the malignancies seen in patients with ulcerative colitis and cannot be explained as a composite of two independent neoplasms that have grown together. Since the tumor discussed seems to have originated from a single cell line, the theory that carcinoids develop from neural crest cells which have migrated to embryonic gut endoderm must be regarded with considerable doubt.

Adenocarcinoma↗
PubMed1981

The macroscopic appearance of colorectal polyps.

The macroscopic (10 to 30 times magnification) surface features of 187 colonic lesions are described. The lesions were studied using a dissecting microscope and a 1% trypan blue solution as a contrast agent. Using five criteria, lesions were evaluated for the presence or absence of adenoma, the type of adenoma present, the presence of dysplasia or carcinoma-in-situ, and the presence of invasive carcinoma. The technique has proven to be a rapid, sensitive, and relatively specific means of separating tumors in the adenoma--carcinoma sequence from nonadenomatous lesions (sensitivity, 99%, specificity 90%). The technique is accurate in differentiating tubular, tubulovillous, and villous lesions. It is suggested that areas of dysplasia (sensitivity 100%, specificity 93%), carcinoma-in-situ, and microinvasive carcinoma may also be differentiated, but need further investigation. The present study suggests that the macroscopic architecture of the various lesions in the adenoma--carcinoma sequence is unique and may be used diagnostically. These preliminary findings need to be confirmed in a prospective double-blind study, and to be adapted to use in colonoscopic and radiologic diagnosis.

Adenoma↗
PubMed1980

Immunoregulatory properties of serum from patients with different stages of syphilis.

The response of lymphocytes from 17 patients with primary, secondary, and tertiary syphilis to phytohaemagglutinin (PHA) and to allogeneic lymphocytes was normal in heterologous serum; however, the responsiveness of cells from some patients with primary and secondary disease was significantly reduced in the presence of autologous serum. As cells from healthy controls invariably responded better to these stimuli in autologous serum, the sera from 81 patients with syphilis were screened for immunosuppressive properties. Sera from 25 primary, 32 secondary, two tertiary, six congenital, and 16 latent cases of syphilis were examined for their ability to reduce the responsiveness of normal cells to PHA. These experiments were performed with test sera as the sole source of serum for the cultures or with test sera added to cultures containing optimally supportive amounts of pooled human plasma.Stimulation of normal cells from one control in human plasma and 20% test serum showed that only in sera from congenital cases of syphilis was the mean response significantly different from the response seen in control sera; a significant increase in the response to stimulation occurred. The range of response to PHA with sera from cases of primary and secondary syphilis was wider than with normal sera. Sera from five (20%) cases of primary and 14 (44%) cases of secondary syphilis appeared to be immunosuppressive. When retested on another sample of normal cells, these sera were consistently immunosuppressive even in the presence of 15% pooled human plasma. Thus, in early syphilis antigenic stimulation may result in the release from suppressor cells of non-specific immunoregulators of cell-mediated immunity. Such phenomena may be a prelude to the development of tolerance to treponemal antigens. In congenital syphilis the development of suppressor cells may be impaired, resulting in the apparent immunostimulatory properties of serum from such cases.

Cells, Cultured↗
PubMed1979

A fluoroimmunoassay for measurement and visualization of antibody bound to surface antigens of HSV-infected cells.

An assay based on quantitative spectrofluorometry of surface immunofluorescence was applied to the study of reactions between antibody and surface antigens of viable HSV-infected cells in suspension. Fluorescence was expressed in terms of photon counts per second. Both the direct and indirect fluorescent antibody techniques proved acceptable for assay of surface reactions, yielding values of specific fluorescence as high as eight times those of controls. Fluorescence microscopy of cell populations assayed by spectrofluorometry allowed for simultaneous visual examination of surface antigens. Comparison of the fluoroimmunoassay with the 51Cr-release test for cytolytic antibody to HSV-induced surface antigens revealed the latter to be the more sensitive, with antibody titres ranging up to four times those detected by fluoroimmunoassay. General correlation between the two assays was found using both rabbit and human sources of antisera.

Animals↗
PubMed1978

Quantitative fluorescent immunoassay of antibodies to, and surface antigens of, Actinomyces viscosus.

Optimal conditions for a fluorescence immunoassay of antibodies to, and surface antigens of, Actinomyces viscosus ATCC 19246 are described. In the standard fluorescence immunoassay, 10(8) colony-forming units of A. viscosus reacted with an antibody preparation, were washed, and then were treated with an excess of fluorescein-conjugated goat anti-rabbit immunoglobulin G. After another set of washes, fluorescence was determined in a spectofluorometer; in most cases excitation was at 485 nm, with emission measured at 525 nm. These conditions minimized interference from light scatter and stray light. Under appropriate conditions, antibodies to A. viscosus could be readily determined, with the fluorescence of the specific antibody-treated cells more than five times the fluorescence of controls treated with normal rabbit serum. Organisms coated with specific antibody could be detected at levels approaching 10(5) colony-forming units per ml. The standard fluorescence immunoassay procedure was readily adapted to the measurement of either particulate or soluble surface antigens of A. viscosus by competition of the antigen with a fixed amount of antibody in the standard assay system; the competition resulted in an antigen dose-dependent inhibition of fluorescence. The fluorescent immunoassay system thus appears to be a general one that could be applied to other microbial systems as well.

Actinomyces↗
PubMed1978

Double-label fluorescence immunoassay of bacteria.

Fluorescence of sensitized bacterial suspensions, reactive with either fluorescein-labeled or rhodamine-labeled antiglobulins, could be quantitatively distinguished in dual-labeled preparations by fluorescence immunoassay.

Actinomyces↗
PubMed1976

Cooperative binding of a complement component to antigen-antibody complexes. III. Complexes containing IgM antibodies.

The first component of guinea pig complement (C1)2) is bound in a cooperative manner to antigen-antibody complexes containing rabbit IgM antibodies, as was previously shown to be the case for IgG antibodies. The shape of the binding curves is consistent with an allosteric mechanism involving clusters of 10 interacting C1 binding sites. Similar results were obtained with IgM antibodies against an artificial hapten and against a natural constituent of the erythrocyte membrane.

Allosteric Regulation↗
PubMed1972

The new alliance.

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Governing Board↗