Biomedical subjects

B Fernandes

Publications and source records attributed to B Fernandes.

At least 55 records · Page 3Linked to original sources

PubMed1978

Analysis of cell-mediated hypersensitivity, immune complexes and monocyte-released factor(s) in allergic alveolitis and asymptomatic exposed subjects.

Patients with allergic alveolitis to various antigens, asymptomatic exposed individuals and healthy control subjects were studied. The lymphocyte transformation test and the formation of two lymphokines were shown to be positive in almost all affected subjects and only rarely in asymptomatic exposed individuals. In most symptomatic subjects and only rarely in asymptomatic exposed individuals. In most symptomatic subjects, the presence of antigen-antibody complexes could be demonstrated. However, such complexes were also present in six of the nine asymptomatic exposed individuals having precipitating antibodies. Factor(s) released from sensitized monocytes strongly facilitate the in vitro formation of specific antibodies but are poorly effective when incubated with cells from asymptomatic exposed subjects or normal individuals.

Alveolitis, Extrinsic Allergic↗

PubMed1977

[Analysis of the macrophage function in sarcoidosis].

This study demonstrates that, in spite of the fairly normal functional capacity of T lymphocytes in sarcoidosis, a deficit of cell-mediated immunity frequently develops. It is shown that monocytes of sarcoidosis seem to share in responsibility for the appearance of this deficit. Soluble factors from sensitized healthy monocytes are shown to be capable of restoring this capacity.

Cell Count↗

PubMed1977

[Immunological aspects of pulmonary granulomatosis with special reference to sarcoidosis].

A wide variety of exogenous or endogenous aggressors exhibit the capacity to induce pulmonary granulomatous lesions. This lesion is characterized by exacerbation of phagocytic function and tentative development of a specific immune response. In many clinical situations there is a well developed circulating antibody response with deficient cell-mediated immunity of variable degree. Finally, it is argued that the granulomatous lesion may be due to abnormal cooperation between T and B lymphocytes.

Antibodies, Viral↗

PubMed1977

Cell-mediated immunity in an ageing population.

Eight hundred and eighty patients hospitalized in a geriatric hospital were routinely tested with 2, 10, 30 and 100 i.u. tuberculin. Among these, fifty-four patients were selected on the basis of negative skin tests and absence of evident diseases interfering with the function of the immune apparatus. A battery of tests analysing cell-mediated immunity was applied to those fifty-four patients. It appears that elderly patients having a negative test to 100 i.u. tuberculin show very infrequent sensitization to three other thymus-dependent antigens. The capacity of this selected population to become sensitized to DNCB is poor (20%). Furthermore they exhibit a low per cent of peripheral blood T cells (36%) and a poor capacity to respond in vitro to mitogens such as PHA. Testing the in vitro response to a battery of antigens demonstrates a good correlation with the results of the skin tests. Finally the leucocytes of 25% of this selected population failed to produce LIF in vitro in the presence of PHA. These results suggest not only an absolute decrease in the population of circulating T lymphocytes in those elderly humans; but very likely, at least in some cases, a functional impairment of T cells.

Adult↗

PubMed1977

Analysis and function of T and B cells subpopulations in sarcoidosis.

Various technical procedure were applied to the purification of T and B lymphocytes subpopulation in sarcoidosis. Patients were selected according to the presence of a characterized deficit in cell-mediated immune functions. These purified lymphocytes populations were further analysed for their ability to release lymphokines in the presence of Con-A-sepharose or specific antigens. Among these factors, MIF, LIF and mitogenic factor (MF) were looked for. For the determination of MIF and LIF, a newly elaborated technique was deviced which allows a semi-quantitative approach of the lymphokine production. The following results were obtained: A decrease in the absolute number of T lymphocytes was observed among all our patients, and a increase in the number of Ig producing cells. A rather large percent (15 to 40%) of null cells which were carrying characteristic features of quiescent, non activable monocytes. The ability of T lymphocytes to release lymphokines was impaired in the presence of these monocytes but could be restored to normal levels when cells were removed. The results suggest that T cell function might be impaired, in sarcoidosis, by a non identified monocytes abnormal behaviour.

B-Lymphocytes↗

PubMed1976

Studies on the mitogenic activity of trypsin, pronase and neuraminidase on human peripheral blood lymphocytes.

Human peripheral blood lymphocytes were cultured in the presence of protease (trypsin and pronase) and Vibrio choleraneuraminidase. T and B lymphocyte populations were separated and the effect of these enzymes plus phytohaemagglutin or Tuberculin was studied. The results of these experiments show that proteases moderately stimulate spontaneous deoxynucleic acid synthesis of control cells and potentiate the effect of tuberculin on sensitized cells. These enzymes act specifically on B lymphocytes. Neuraminidase also increases spontaneous deoxyribonucleic acid synthesis of control cells and augments significantly the in vitro response to PPD. There is no additive effect of neuraminidase on phytohaemagglutin stimulated cells. Neuraminidase seems to stimulate specifically T lymphocytes. Some possible mechanisms of action of these enzymes are proposed and discussed.

B-Lymphocytes↗

PubMed1975

[T-and B-lymphocytes in lymphoproliferative syndromes].

Using the various markers of human lymphocytes, it is possible to define, at least roughly, some malignancies of the lymphoid system in terms of their components in T and B cell subpopulations. Furthermore, the study of surface-immune globulins using labelled antisera specific for heavy and light chain classes, has made it possible to define the concept of monoclonal proliferation of B cells. Following a short description of the various interrelationships between B and T lymphocytes, the main lymphoproliferative diseases are briefly described in terms of B or T nature of tumoral cell lines and their bearing on the overall function of the immune apparatus.

B-Lymphocytes↗

PubMed1974