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Biomedical subjects

N F Mendes

Publications and source records attributed to N F Mendes.

At least 55 records · Page 3Linked to original sources
PubMed1978

Decreased lymphocyte response to PHA, Con-A, and calcium ionophore (A23187) in patients with RA and SLE, and reversal with levamisole in rheumatoid arthritis.

The mechanism of poor lymphocyte transformation to mitogens was studied in selected patients with rheumatoid arthritis and systemic lupus erythematosus. Low lymphocyte response to PHA and Con-A in media containing autologous and homologous sera was usually associated with poor response to the calcium ionophore A23187, which induces blastogenesis by a different mechanism. The low lymphocyte response to mitogens in patients with rheumatoid arthritis could be restored by in vivo treatment with the anthelmintic drug, levamisole. The present findings suggest that intrinsic defects are responsible for the decreased cellular response in patients with rheumatoid arthritis and systemic lupus erythematosus.

Adolescent↗
PubMed1978

Suppression of C3 rosette formation by serum from patients with systemic lupus erythematosus. A corollary of disease activity.

Many sera from patients with systemic lupus erythematosus (SLE) inhibit C3 rosette formation of normal human lymphocytes. Fractionation of SLE sera by Sephadex G-200 gel chromatography showed that the inhibition was present in low molecular weight serum fractions. A correlation was noted between inhibition of C3 rosette formation and disease activity. Inhibition of C3 rosette formation may be helpful and simple way to monitor clinical activity and complement activation in patients with SLE.

Adult↗
PubMed1977

Cellular immunity in chronic Chagas' disease.

The cellular immune response was assessed in 20 patients with chronic Chagas' disease (American trypanosomiasis). Thymus-derived lymphocyte function was determined in vivo by cutaneous reactivity to several antigens including a soluble preparation derived from Trypanosoma cruzi and sensitization to 2,4-dinitrochlorobenzene. The in vitro T-cell reactivity was investigated by the proliferative response to phytohemagglutinin and to T. cruzi antigen and by inhibition of leukocyte migration with the specific antigen. In addition, the proportion and absolute numbers of peripheral blood T and B-lymphocytes were determined by rosette formation. This research indicates that the general and specific cellular immune response, evaluated by the tests herein mentioned, is well preserved in patients, with Chagas' disease. We conclude that chronic Chagas' disease is not associated with deficiency in cellular immunity, nor does it lead to it. Conceivably, the active participation of delayed hypersensitivity may play an important role in the expression of the human chagasic lesions.

Adult↗
PubMed1977

Immunological identification of human lymphoid cell populations.

Lymphocytes can be subdivided into two major groups according to origin and function (1,2). T lymphocytes are thymus dependent and are responsible for cell-mediated immunity while the B lymphocytes represent precursors of immunoglobulin-producing plasma cells and give rise to humoral immunity. Considerable knowledge concerning the biological properties of T and B lymphocytes and their mutual interaction has been obtained in the last few years. Recent data also demonstrate further heterogeneity within each of the two main lymphocyte populations. Certain lymphoid cells are capable of mediating cytotoxicity against target cells coated with specific antibody. These cells are termed K cells, and although some evidence seems to suggest that they comprise a subpopulation of B lymphocytes, their nature and localization in lymphoid organ is not well known. This article will attempt to cover the methodologies involved in assays of T, B, and K cells. The methods to be discussed are used to detect the presence of different lymphoid cell populations; the markers used are not necessarily related to cell function.

Animals↗
PubMed1976

Cell-mediated immunity in patients with carcinoma: correlation between clinical stage and immunocompetence.

Cell-mediated immunity (CMI) was evaluated in 82 patients with non-lymphoid tumors by in vivo and in vitro methods. These included skin test with ubiquitous antigens, 2,4 dinitrochlorobenzene (DNCB) sensitization, determination of T and B peripheral blood lymphocytes, and lymphocyte response to phytohemagglutinin (PHA). The patients were divided into two groups: those with localized and those with disseminated disease (LD and DD). The patients with LD showed no significant differences in CMI when compared with normal controls. The patients with DD showed various defects in CMI when compared with controls and patients with LD. There were significant differences in the response to DNCB, and streptokinase-streptodornase (SK-SD) was the most discriminative of the skin-test antigens. The response to PHA was greatly depressed in patients with DD, whether in the presence of autologous or homologous plasma; in some patients a factor inhibiting to blastogenesis was detected in the serum. In patients with DD, a T-cell lymphopenia was observed. These data showed a correlation between immunocompetence and clinical stage.

Adult↗
PubMed1976

Rosétte formation between human b lymphocytes and zymosan-C3 complexes using different complement sources.

Sera from five animal species were studied as complement source in the preparation of zymosan-C3 complexes used to detect human B lymphocytes. There was no significant difference in the determination of the percentage of ZC rosette forming cells due to differences in complement source. Human B lymphocytes could not discriminate C3 from different species studied. Every one of these sources of complement may be used interchangeably without altering the percentage of B cells detected by this method.

Adolescent↗
PubMed1976

Peripheral blood T and B lymphocytes, in vitro stimulation with phytohemagglutinin, and sensitization with 2,4-dinitrochlorobenzene in Grave's disease.

The percentage and absolute numbers of thymos-dependent (T) and thymos-independent (B) peripheral blood lymphocytes, the in vitro response of lymphocytes to phytohemagglutinin (PHA), and the sensitization with 2,4dinitrochlorobenzene (DNCB) was studied in 26 patients with hyperthyroidism due to Graves' disease. The results showed a normal percentage of both T and B cells and increased absoluted numbers of total lymphocytes in patients compared with 30 healthy controls. The in vitro response to PHA was normal in most patients with the exception of 5 of them who showed an impaired response. All patients developed a reaction of delayed hypersensitivity to DNCB. Our study indicated that there is no general abnormality in cell-mediated immunity in Graves' disease.

Adolescent↗