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Biomedical subjects

M Waller

Publications and source records attributed to M Waller.

At least 37 records · Page 2Linked to original sources
PubMed1982

Heterogeneity of soluble T cell products. I. Precursor frequency and correlation analysis of cytotoxic and immune interferon (IFN-gamma)-producing spleen cells in the mouse.

In this study, the precursor frequency, relationship and activity of murine splenic cytotoxic and immune interferon (IFN-gamma)-producing cells has been determined. C57BL/6 spleen cells were activated by concanavalin A (Con A) and subsequently grown in microcultures under limiting dilution conditions. The progeny of cells plated in microcultures was divided and tested for (a) total cytotoxic activity on EL4 (H-2b) tumor target cells in the presence of Con A to nonspecifically attach the killer to the target cells, and (b) the quantity of IFN-gamma released by Con A stimulation. Cytotoxic T lymphocytes and IFN-gamma-producing cells were present in Con A-activated C57BL/6 spleen cells at a high frequency of approximately 1 out of 3 and 1 out of 2 cells, respectively. IFN-gamma could be released from both noncytotoxic and a large fraction of cytotoxic T cells and the cytotoxic activity was not necessarily associated with IFN-gamma release. In a few selected cultures with a progeny of cells plated at a low cell number (up to 10/well) very high IFN-gamma titers (greater than 10 000 U/ml) could be found. These results provide the first frequency estimate of IFN-producing cells and are discussed with respect to the physiological role of IFN-gamma release from T cells.

Animals↗
PubMed1981

Production of immune interferon by murine T-cell clones from long-term cultures.

Production of leukocyte interferon (IFN-alpha) and fibroblast interferon (IFN-beta) can be induced by a variety of agents but immune interferon, IFN-gamma, is only obtained when lymphoid cells are stimulated by specific antigens, allo-antigens or T-cell mitogens. Moreover, in bulk cultures, only small quantities of IFN-gamma are produced. The type of cell producing IFN-gamma has not been unambiguously defined and so we set out to determine whether a pure T-cell population could produce it, exploiting the knowledge that T cells can be maintained indefinitely in tissue culture by the addition of T-cell growth factors. Although not all T cells can found long-term cultures of this kind, cultures of antigen-specific helper, suppressor and killer T cells have been obtained in this way. We now describe the production of substantial amounts of INF-gamma when some (but not all) murine T-cell clones derived from such cultures are stimulated by either concanavalin A (Con A) or phytohaemagglutinin (PHA).

Animals↗
PubMed1981

Nonantibody binding of serum proteins to 5S anti-Rh fragments produced by chymotrypsin.

Chymotrypsin hydrolysis of the IgG anti-Rh antibodies Ri results in both bivalent and univalent antibody fragments. The bivalent fragments coated on Rh-positive erythrocytes are agglutinable by albumin and other serum proteins in 3% polyethylene glycol. The bivalent structure of the 5S fragment is essential for expression of this site since 5S fragments produced by trypsin and pepsin are also agglutinable, while univalent fragments produced by papain and subtilisin are not. The agglutination by albumin of the 5S fragments is not caused by residual enzyme. The reaction appears to be irreversible in that once albumin has reacted with the 5S fragment, either in the fluid phase or at the cell surface, fresh addition of albumin and PEG will not result in agglutination. The nonantibody reaction of albumin and the other serum proteins with these 5S IgG fragments is believed to be caused by hydrophobic bonding involving the intrachain disulfide in the 5S fragment and hydrophobic areas of other proteins.

Antibodies↗
PubMed1978

Nephelometric method for determination of rheumatoid factor.

We have developed a nephelometric technique for determining titers of rheumatoid factor. Serum dilutions are added to a mixture of commercially available latex particles of small size (0.098 micrometer) and human gamma-globulin. Rheumatoid sera induce a substantial increase in the light scattering properties of the mixture, and the highest dilution significantly increasing the light scattering is considered as the titer for that serum. This technique is simple to use, provides objective results, and can be automated for analysis of large numbers of samples.

Humans↗
PubMed1978

[Diploid and aneuploid human cell lines from autopsy material in long term cultures. Investigations of growth behaviour and karyotype (author's transl)].

Experiences with the development and characterization of cell lines obtained from human autopsy material, mainly of peripartal deceased children with multiple malformations, are reported. On 7 diploid and 4 aneuploid fibroblast-like cell lines (2 cases of trisomy G, 2 cases of trisomy E) investigations of the whole life span in vitro, on the growth behaviour and morphology as well as karyotype analyses in the early, middle and late phases of cultivation were carried out. All cell lines showed a definite limited life span, their doubling potential being on the average greater than 30 +/- 5. Compared with results from literature, these values had been found to be between those of cells of embryonic and adult origin and are possibly dependent on the age of the donor. No morphologic signs or changes of cell kinetic parameters were found which might point to a spontaneous cell alteration. The karyotype determined in the early culture phase was stable until the natural end of the cell lines. The results may serve as an evidence for the stability of all investigated parameters and for a reproducible growth behaviour in diploid and aneuploid cell lines developed from human autopsy material, a prerequisite to sue them as an in vitro model for further investigations.

Aneuploidy↗
PubMed1977

The action of N-methyl-N-nitrosourea on non-established human cell lines in vitro. I. Cell cycle inhibition and aberration induction in diploid and Down's fibroblasts.

The effect of N-methyl-N-nitrosourea (MNU) on the cell cycle, DNA synthesis and chromosomal sensitivity of cultivated diploid fibroblasts and fibroblasts with trisomy 21 was investigated in vitro. With the exception of the inhibition of G2, Down's cells proved to be more sensitive than diploid cells with respect to the decrease of the mitotic and labelling index, the inhibition of the progression of cells through the early and middle S and the frequency of induced chromosomal aberrations. The chromosomal sensitivity was dependent on the position of cells in the cell cycle during treatment with MNU. If treated during late S no differences concerning the S block and aberration frequencies were found between diploid and Down's cells. However, if MNU treatment took place in the middle and early S, Down's cells were more sensitive. The higher aberration frequencies in Down's cells resulted from elevated levels of chromatid breaks, multiple fragmentations and chromatid translocations. Possible reasons for the increased sensitivity of Down's cells are discussed.

Cell Division↗
PubMed1976

Antirat erythrocyte agglutinins.

Antirat hemagglutinins may be found in the sera of both normal and sick persons. High titers of these antibodies are influenced by the major blood groups, the antigen B tending to suppress these antibodies, and by age where juveniles have higher titers than adults. Elevated titers may be stimulated by immunization, injection of pooled gamma-globulin, infection, and transplantation.

ABO Blood-Group System↗
PubMed1976

The frequency of 7S rheumatoid factors and 22S complexes in human sera with positive latex tests for rheumatoid factor.

In sera with positive latex tests for rheumatoid factors, the immunoglobulin class of the antiglobulins is influenced by the quantity of immunoglobulins present in the serum. Sera with 7S antiglobulins have high levels of IgG and IgA immunoglobulins. 22S complexes tend to be found in sera with high levels of IgM immunoglobulins. These findings suggest that the occurrence of antiglobulins and 22S complexes may be influenced by the hypergammaglobulinemia.

Adsorption↗
PubMed1976

Factors influencing tests for infection and inflammation.

Four laboratory tests performed on 236 persons showed a positive correlation with the erythrocyte sedimentation rate when that test was negative or strongly positive. Most of the tests were influenced by sex and by age.

Agglutination Tests↗
PubMed1975

The hydrolysis of human IgG with subtilisin.

Small amounts of subtilisin (0.1 mg. per ml.) in the absence of cysteine will instantaneously hydrolyze "enzyme-sensitive" IgG globulins. This procedure permits the identification of antibodies in whole serum and myeloma globulins in the ultracentrifuge with simplicity and speed unmatched by other technics.

Bromelains↗
PubMed1975

Humoral antibody responses following transplantation in man.

Sequential titers of five different humoral antibodies (antirat erythrocyte, antisheep erythrocyte, isoantibodies, rheumatoid factors, and serum agglutinators) were simultaneously performed on 20 patients with renal transplants, 12 patients with skin transplants, and 2 patient populations (one hospitalized and one ambulatory). The results suggested that rises in titer of any of these antibodies could not be used as an indicator of acute rejection. Nevertheless, patients who lacked rejection episodes were unlikely to show humoral responses and always lacked antiglobulin responses. Heterophil responses always preceeded antiglobulin responses. These results suggest that heterophils are cross reacting antibodies and antiglobulins are auxillary immune responses.

Absorption↗
PubMed1975

A mixed antiglobulin test with kidney cells in suspension for IgG antibody in human allograft recipients.

A modification of the mixed antiglobulin test for the detection of IgG antibodies directed against human kidney cells has been devised which uses a suspension of individual kidney cells rather than a monolayer culture as antigen so that it may be enployed clinically as a prospective crossmatch for organ transplantation. The antiglobulin reagent is added to the sensitized kidney cells rather than to the indicator erythrocytes, which reduces the background of nonspecific reations almost to zero. It is reproducible. The mixed antiglobulin test detected antibody in the sera of patients on chronic dialysis two to four times more frequently than did either the immune adherence test or the most sensitive modification of the microlymphocytotoxicity test which was utilized. It detected the development of antibody specific for donor kidney cells in the sera of 5 of 10 allograft receipients during periods of good to moderate renal transplant function several months before rejection.

Animals↗