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J M MacSween

Publications and source records attributed to J M MacSween.

53 records · Page 3Linked to original sources
PubMed1978

Cellular immunity to a lung homogenate in asymptomatic cigarette smokers.

Leucocyte migration in the presence and absence of a soluble lung homogenate has been studied in a group of asymptomatic cigarette smokers. Results were expressed as migration indices. Controls consisted of age-matched subjects who had never smoked and had no past history of any pulmonary disease. The migration indices, the number of pack-years smoked and the results of pulmonary function studies were tested for correlation. The mean leucocyte migration index of the test group of sixteen smokers was significantly less than was that of the control group (P less than 0.001). Inhibition of leucocyte migration in the presence of the lung homogenate was not observed in any of the control subjects. Six of the sixteen asymptomatic cigarette smokers, however, were identified by inhibition of leucocyte migration in the presence of the lung homogenate. The number of pack-years which had been smoked did not correlate with the migration indices (r = -0.06); however, inhibition of leucocyte migration was not observed in subjects who had smoked less than 6 pack-years.

Adult↗
PubMed1977

The quantitative relationship of carcinoembryonic antigen to tumor cells of different organs.

Carcinoembryonic antigen (CEA) was measured in extracts of cell suspensions from tumors of the colon, stomach, breast, lung and kidney. Cell suspensions were also obtained from normal tissue surrounding the primary tumors. The number of neoplastic cells in each cell suspension was determined by cytologic criteria. Highest CEA concentrations were found in cells obtained from carcinoma of the bowel. There also appeared to be a greater difference between the concentrations of CEA in colonic tumors and either surrounding normal tissue or serum, than in tumors of other organs. There was no apparent correlation of the concentration of CEA in tumor cells and the presence or absence of metastases. The presence of CEA in normal cells from tissue adjacent to tumors was suggestive of increased synthesis of CEA by these cells in some cases.

Breast↗
PubMed1976

Cytotoxic lymphocytes in infectious mononucleosis.

Seven patients with a clinical diagnosis of infectious mononucleosis (IM) and detectable heterophil antibodies were found to have peripheral blood lymphocytes that were cytotoxic for lymphoid cells containing Epstein-Barr virus from a patient with Burkitt's lymphoma. The cytotoxic lymphocytes persisted in the peripheral circulation for up to 45 days. Patients who had had IM 1 to 5 years previously lacked such cytotoxic lymphocytes. Patients who had signs and symptoms of IM but no detectable heterophil antibodies lacked cytotoxic lymphocytes. The lymphocytes of one patient with IM showed progressive diminution of cytotoxic ability after prednisone treatment.

Adult↗
PubMed1976

Potentiation of the macrophage response to migration inhibition factor from fetal calf serum by blood group substances with human H activity.

Soluble blood group substances, with human H and A activity, have previously been shown to block the interaction between guinea pig peritoneal macrophages and migration inhibition factor from fetal calf serum (FCS-MIF). Conversely, incubation of macrophages at 37 degrees C for 1 h in the presence of 0.1% blood group substance, followed by thorough washing, potentiates the action of FCS-MIF. The sensitivity of the macrophages is markedly increased, allowing detection of subthreshold levels of FCS-MIF. Blood group substances (BGS) labeled with radioidine are taken up by macrophages, and a proportion remains on the surface. This radiolabeled BGS is lost from the surface spontaneously, and the rate of loss is increased by treatment with trypsin. It is suggested that the BGS mimic the natural macrophage receptor for FCS-MIF and potentiate its effect by incorporating new receptors into the macrophage membrane.

ABO Blood-Group System↗
PubMed1976

E rosette formation by human t lymphocytes: a spontaneous cell mediated cytotoxic phenomenon.

The nature and significance of spontaneous association between unsensitized human T lymphocytes and sheep erythrocytes has been studied in relation to a possible cytotoxic reaction. Human lymphocytes and 51Cr labelled sheep erythrocytes when mixed in ratios of 5 or 10:1 released 70-100% of 51Cr into the supernatants. This suggests that E rosette formation may be the first step in a spontaneous T cell mediated cytotoxic reaction to sheep erythrocytes.

Animals↗
PubMed1976

Lymphocyte responses to phytohaemagglutinin: age-related effects.

Cell-mediated immunity is depressed in elderly individuals compared to young individuals, and lymphocytes from elderly individuals have been reported to have impaired lymphocyte responsiveness to stimulation by PHA after 4 days of culture. We have confirmed this observation. However, after 8 days of culture, the lymphocyte responses were greater in elderly normal individuals than in young normal individuals. Responses of lymphocytes from young individuals decreased with time from 4 to 8 days in culture, while there were increased responses with time when lymphocytes from elderly individuals were studied. When adherent cells from lymphocytes of young individuals were removed by passage through protein-coated Degalan-bead columns, the lymphocyte responses to PHA were significantly increased at 8 days. Passage of lymphocytes from elderly individuals through coated Degalan bead columns did not alter the lymphocyte responses. Removal of macrophages from the mononuclear cells obtained from young individuals did not result in increased lymphocyte responses to PHA after 8 days in culture. Removal of adherent cells appeared to have the same effect regardless of the efficiency of removing B cells. The adherent cells removed by the protein coated columns, therefore, appear to be nonphagocytic mononuclear cells which are not B lymphocytes.

Adult↗
PubMed1975

The antigenicity of carcinoembryonic antigen in man.

Binding of globulins to -125I CEA was detected in 10 of 24 sera from patients with cancer, 13 of 26 sera from blood donors, and 7 of 27 supernates of tumor-cell suspensions. Binding was predominantly by IgM in 10 of 14 sera tested by radioimmunoelectrophoresis. Binding was inhibited by 6 ng unlabelled CEA in one instance only, and by adsorption with blood group A erythrocytes in three cases. Binding was not increased in dialysed precipitates formed by ammonium sulfate at pH 2.5, while there was increased binding in precipitates of complexes of CEA and heterologous anti-CEA. These results confirm that human IgM binds to CEA, and in some cases binding appears to be mediated by antibodies to blood group A. However, the binding is weak and appears to be of low affinity. This suggests that binding of CEA by immunoglobulins represents cross-reactivity by antibodies to similar antigens, of which blood group A is one example.

Adsorption↗
PubMed1975

Separation of T lymphocytes from normal individuals and patients with B lymphocyte chronic lymphocytic leukaemia.

Previous studies have shown that lymphocytes from patients with chronic lymphocytic leukaemia have a diminished response to mitogens which stimulate T cells. Chronic lymphocytic leukaemia is most often a disease of accumulating B cells so that T lymphocytes are diluted by large numbers of leukaemic cells. Direct comparison with the responses of normal lymphocytes to mitogenic stimulation is therefore suspect. To circumvent this difficulty, a method of isolating T cells from normal individuals and patients with chronic lymphocytic leukaemia was developed. Lymphocytes containing an average of 16.1 per cent B cells from normal individuals were applied to IgG-anti-IgG-coated Degalan bead columns and held at 4 degrees for 2 hours. The eluted cells contained less than 2 per cent B cells. When chronic lymphocytic leukaemic lymphocytes, containing an average of 68.6 per cent B cells, were applied to IgG-anti-IgG columns, the eluted cells contained 36.4 per cent B cells. To improve the purification of T lymphocytes, columns of uncoated Degalan beads were used to remove non-specifically adherent cells. Eluted lymphocytes were then applied to IgG-anti-IgG columns. This resulted in the recovery of purified populations of T cells with less than 2 per cent contamination with B cells. Patients with chronic lymphocytic leukaemia were found to have lymphocytes with either a normal density or a low density of surface immunoglobulins. B cells were successfully removed from lymphocyte suspensions in all cases of chronic lymphocytic leukaemia with a normal density of lymphocyte surface immunoglobulins. In the three cases of chronic lymphocytic leukaemia with low density surface immunoglobulins, separation by this method was unsuccessful. However, an enriched T-cell population was obtained when leukaemic lymphocytes which had lost all detectable surface immunoglobulins were passed through a column coated with heat-aggregated IgG.

Animals↗
PubMed1972

Carcinoembryonic antigen in whole serum.

A microradioimmunoassay technique is described for detecting carcinoembryonic antigen (CEA) in whole serum. It differs from previous methods in being performed on 0·025 ml of whole serum instead of 5 ml of serum extracted with perchloric acid. The present assay was sufficiently sensitive to detect 85% of carcinomata, localized to the colon, but positive results occurred also with certain non-gastrointestinal cancers, chiefly lung and breast, and certain non-malignant diseases. Many of the latter sera, with the general exception of alcoholic cirrhosis and pancreatitis, gave negative results after extraction with perchloric acid. It is suggested that a direct assay for CEA in whole serum may permit testing of large numbers of sera by laboratories with facilities for radioimmunoassays.

Ammonium Sulfate↗