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Biomedical subjects

N F Mendes

Publications and source records attributed to N F Mendes.

At least 19 recordsLinked to original sources
PubMed1992

Delayed hypersensitivity skin tests in prognosis of human immunodeficiency virus infection.

Delayed hypersensitivity skin tests (DHST) with recall antigens were investigated as prognostic markers in five different approaches. In the first study, 42 acquired immunodeficiency syndrome (AIDS) patients (IVb, IVcl, IVd, and IVe; MMWR 35:334-339, 1986) 26 AIDS-related complex (ARC) patients (IVa and IVc2), and 98 asymptomatic patients (II and III) were evaluated with candidin, tricophytin, PPD and streptokinase-streptodornase. In the second study, 10 patients (II and III) were evaluated sequentially with the same antigens. In the third, 45 patients with at least two positive skin tests ("reactors") were followed for one year and evaluated every 6 months with the same antigens. In the fourth, 16 "reactors" were followed and evaluated every 3 months with the same antigens. We measured the interval from the time at which patients first presented with only one or no positive DHST until the development of ARC or AIDS. In the last study, the correlation between absolute number of CD4+ lymphocytes and the number of DHST was studied in 151 patients. We found that the decrease in reactiveness to DHST correlated directly with the progression to AIDS, demonstrating the usefulness of this simple procedure as a valid prognostic marker.

AIDS-Related Complex↗
PubMed1991

Molecular forms of soluble human T lymphocyte receptor for sheep erythrocytes in serum and saliva.

Using a specific serum anti-soluble T lymphocytes receptor for sheep erythrocytes (E) and SDS-PAGE, we detected radioactive bands of molecular weight 58,000 in immunoprecipitates of supernatant of heated human lymphocytes (SHL), in the supernatant of PHA stimulated lymphocyte cultures (SLC), normal human serum (NHS), and serum from cancer and uremia patients, labelled with 131I. By Sephadex G-200 chromatography, in addition to this fraction, we detected molecules of molecular weight higher than 150,000 which interact with the anti-soluble receptor serum (anti-RS), in serum from cancer and uremia patients. These molecules were detected in NHS or SHL after concentration or by prolonged exposure of SDS-PAGE with some labelled and immunoprecipitated SHL samples. The soluble receptors of molecular weights 58,000 (RS1) and more than 150,000 (RS2) were fully identical when analyzed by immunodiffusion with anti-RS serum. When submitted to immunoelectrophoresis, RS1 showed electrophoretic migration similar to that of albumin, while RS2 showed a pattern close to that of alpha 2-globulin. However, RS2 did not show antigenic relationship with IgM and was not an immune complex with IgG. Even though the presence of RS in human saliva has not yet been reported, molecules that interact with anti-RS serum have been detected in human saliva and are fully identical to molecules found in supernatant of heated human T lymphocytes and NHS. The RS molecules present in human saliva have a molecular weight and electrophoretic migration similar to those of RS1 from SLC and from human serum and have no antigenic relationship with human albumin.

Animals↗
PubMed1991

Purification of soluble human T lymphocyte receptors for sheep erythrocytes.

Using a polyclonal heterologous anti-soluble E-receptor serum, we identified molecules of molecular weight circa 58,000 and 150,000. The soluble receptor molecule with molecular weight of approximately 58,000 (Rs1) was initially purified from supernatant of heated lymphocytes through chromatography on Sephadex G-200 and/or DEAE-cellulose. The soluble receptor molecule with molecular weight of approximately 150,000 (Rs2) is detected at high levels in the serum of patients with cancer and uremia. Rs1 and Rs2 present in serum from cancer patients were purified by chromatography on Sephadex G-200 and by affinity chromatography using anti-Rs1 IgG. 131I-labelled supernatant of heated lymphocytes binds to sheep erythrocytes and the elution and analysis of the molecules adsorbed showed bands of molecular weights approximately 58,000 and 150,000, confirming the receptor activity of these molecules.

Animals↗
PubMed1991

Quantitation of the soluble E-receptor of human T lymphocytes by rocket electrophoresis in the serum of patients with lepromatous and tuberculoid leprosy.

Human T lymphocytes carry a membrane receptor for sheep erythrocytes (E) which is responsible for the well-known phenomenon of E-rosette formation. This receptor has been related to CD2 molecules; it is present in a soluble form (Rs) in normal serum and may play an immunoregulatory role. In this study we quantitated soluble E-receptor in serum samples of 43 normal controls, 32 patients with tuberculoid leprosy and 53 with lepromatous leprosy, using rocket electrophoresis and an anti E receptor serum (anti-Rs) obtained from an adult sheep immunized with autologous E treated with Rs. In the 3 groups studied, the rocket means were respectively 5.0, 7.5 and 10.9 mm (p less than 0.001). We found abnormally high levels of Rs in the serum of various diseases associated with a depression of cell-mediated immunity. The increase of Rs levels in the serum may be one of the mechanisms responsible for the depression of cellular immunity in leprosy.

Adult↗
PubMed1990

Seroepidemiological studies of HIV-1 infection in large Brazilian cities.

The prevalence of HIV-1 antibodies in selected groups of individuals from Rio de Janeiro, São Paulo and Santos was determined retrospectively. These groups and respective prevalences were: hemophiliac patients from Rio de Janeiro (1983-1984) 98.0%; polytransfused hemodialysis patients from São Paulo (1985-1986) 3.0% and (1987) 7.7%; intravenous drug addicts from São Paulo and Rio de Janeiro (1986-1987) 15.9%; male prisoners from São Paulo (1988) 12.5%, and pregnant women from Santos (1988-1989) 3.6%. These data stress the magnitude of AIDS in Brazil.

Adolescent↗
PubMed1979

Serum amyloid protein SAA, C-reactive protein and lysozyme in leprosy.

Serum amyloid protein (SAA) appears to be the precursor of amyloid protein AA, the non-immunoglobulin fibril protein of secondary amyloidosis. Since amyloidosis is known to occur in high frequency associated with lepromatous leprosy (LL), we have examined the SAA levels in untreated LL patients and compared them to the levels observed in patients with tuberculoid leprosy (TT) and a large number observed in healthy controls. We found that SAA is markedly elevated in LL when compared to TT and controls. No clear correlation could be established with C-reactive protein, a well-documented acute phase reactant, or serum lysozyme levels that reflect the presence of monocyte activity. This study showed that SAA levels in leprosy do not appear to be a reflection of inflammatory activity or monocyte turnover. Whether amyloidosis will be more prevalent in patients who have higher SAA levels remains to be determined.

Amyloid↗
PubMed1978

Cellular immunity in squamous cell carcinoma of the uterine cervix.

The thymus-dependent immunity of 42 patients with SCCC was evaluated by: delayed cutaneous reactions to ubiquitous antigens, DNCB sensitization, and lymphocyte response to PHA. In addition, T and B lymphocytes were detected in peripheral blood and in tumor sections, by adherence to E and HEAC. Depressed CMI was more intense in patients with disseminated disease, although a premature impairment of CMI was observed in some patients with initial-stage tumors. The absolute number of peripheral T lymphocytes showed association with both cutaneous reactions and PHA response. However, there appeared to be no significant correlation between the stage of the tumor and the pattern of adherence of E or HEAC to the biopsies.

Adult↗
PubMed1978

Monocyte function in patients with solid neoplasms during immunotherapy with Corynebacterium parvum.

The present studies were performed in order to evaluate monocyte function in patients with solid neoplasms before and after administration of C. parvum. The results demonstrate that monocytes from cancer patients display increased numbers of C3 and Fc receptor sites after administration of C. parvum. It is concluded that characterization of monocyte receptor activity may be helpful in monitoring the effects of immunotherapy in the immune system.

Chemotaxis, Leukocyte↗
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↗