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Biomedical subjects

S Gupta

Publications and source records attributed to S Gupta.

At least 1,585 records · Page 88Linked to original sources
PubMed1983

Autologous mixed lymphocyte reaction in health and disease states in man.

In this review are discussed the nature of T cell subsets, defined with monoclonal antibodies, responding in T-non-T and T-T autologous mixed-lymphocyte reactions (AMLR) and antigens stimulating in AMLR, soluble products of AMLR and generation of suppressor, helper and cytotoxic functions. On the basis of these data a model of immunoregulation in vivo can be proposed. We believe that AMLR is a real-phenomenon and not an artefact and perhaps represents a mechanism by which various immune functions are regulated, including feedback regulation of AMLR. The significance of AMLR is further supported by studies in various human and animal diseases.

Adult↗
PubMed1983

Adult polio-like syndrome following Enterovirus 70 conjunctivitis (natural history of the disease).

During the Indian EV 70 conjunctivitis epidemic in 1981, 79 patients with neurological complications were evaluated by clinical, electrophysiological, histopathological and virological studies. The disease was heralded by an attack of conjunctivitis and was followed, after a variable latent period, by a pre-paralytic, paralytic, and post-paralytic stage of slow recovery. The above events occurred in an orderly sequence. The paralysis affected the cranial nerves, limbs or both. The clinical course closely simulated poliomyelitis, without any evidence of radiculopathy or myelopathy. Cranial nerve palsies were seen in approximately half of the patients. The electrophysiological and histologicl studies pointed towards the affection of anterior horn cells. The raised neutralizing antibody titres to Enterovirus 70, confirmed the aetiology of the disease. On the available data, we believe that this nosological entity should be considered under the general title of "polio-like syndrome" following EV 70 conjunctivitis. On account of two epidemics in 1971 and 1981 with unfavourable prognosis and high resultant disability, and because of lack of specific therapy, it has become imperative to develop, as a top priority, a vaccine for immunization.

Adult↗
PubMed1983

Deficiency of concanavalin A induced suppressor cell activity in patients with primary immunodeficiency disorders.

Peripheral blood mononuclear cells (PBMC) from 40 patients with a variety of primary immunodeficiency diseases were examined for concanavalin A (Con A) inducible suppressor activity against proliferative response of autologous and allogeneic PBMC to phytohaemagglutinin (PHA). 45% (12/27) of the patients with common variable immunodeficiency and 86% (6/7) of the patients with selective IgA deficiency demonstrated lack of Con A-induced suppressor activity against proliferative response of autologous/allogeneic PBMC. 2 of 4 patients with X-linked agammaglobulin and both patients, each with Wiskott-Aldrich syndrome and ataxia-telangiectasia, also showed deficient suppressor function. This study demonstrates a deficiency of Con A-inducible suppressor-cell activity in a variety of immunodeficiency diseases. Possible underlying mechanisms for this functional defects are discussed.

Adolescent↗
PubMed1983

Colony-forming lymphocytes in man. II. Increased phytohemagglutinin-induced T lymphocyte colony formation in aging humans.

Phytohemagglutinin-induced T cell colony (greater than 50 cells/aggregate) and cluster (10-50 cells/aggregate) formation was studied by one-stage microagar culture in glass capillaries by peripheral blood mononuclear cells from 26 young healthy individuals (20-32 years) and 26 aging subjects (greater than 65 years). The number of colonies developed after phytohemagglutinin (PHA) stimulation of mononuclear cells from aging subjects was significantly increased (p less than 0.05) when compared to those from simultaneously studied young individuals. Increase in the number of PHA-induced colonies by lymphocytes from aging subjects over that of young subjects was observed at different concentrations of PHA. The highest level of colony formation in mononuclear cells from both aging and young subjects was obtained with 10 micrograms/ml of PHA. Possible mechanisms for increased T cell colony formation in aging humans are discussed.

Adult↗
PubMed1983

Deficient autologous mixed lymphocyte reaction in Kaposi's sarcoma associated with deficiency of Leu-3+ responder T cells.

Autologous mixed lymphocyte reaction (AMLR) and T cell subsets defined with monoclonal antibodies were analyzed in the peripheral blood of homosexual males with Kaposi's sarcoma (KS). All seven patients demonstrated decreased AMLR (P less than 0.001) when compared with age- and sex-matched simultaneously studied controls. These patients also showed decreased proportions of Leu-3+ (helper/inducer phenotype) and an increase in the proportion of Leu-2+ (suppressor/cytotoxic phenotype) T cells. Leu-3+ T cells were purified from two patients by depleting Leu-2+ T cells in complement-dependent cytotoxicity. Leu-3+ T cells from both patients demonstrated poor proliferative response in the AMLR. In allogeneic MLR, patients' T cells were poor responders and their non-T cells were poor stimulators against healthy controls. This study demonstrates deficiency of both AMLR and allogeneic MLR in patients with KS. The decreased AMLR is associated with qualitative and functional deficiency of Leu-3+ responder T cells. Whether the functional deficiency of Leu-3+ responder T cells in the AMLR is a general phenomena or a feature of a subset of patients with KS remains to be determined.

Adult↗
PubMed1983

Spontaneous and concanavalin A induced suppressor cell activity in patients undergoing bone marrow transplantation: relationship with acute and chronic graft versus host disease.

Peripheral blood mononuclear cells from 23 patients with acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML) or aplastic anemia (AA) undergoing allogeneic bone marrow transplantation were examined for spontaneous and Concanavalin A (Con-A)-induced suppressor activities against proliferative response of autologous or allogeneic responder lymphocytes to phytohemagglutinin (PHA) and for its relationship with acute or chronic graft-versus host disease (GVHD). Patients who developed acute GVHD had increased spontaneous and deficient Con A-induced suppressor cell activity, whereas patients who developed chronic GVHD or had no evidence of GVHD had both spontaneous and Con A-induced suppressor cell activity essentially similar to that of healthy controls. The nature of underlying disease (ALL v. AML v. AA) had no relationship with the abnormal suppressor functions. Depletion of adherent monocytes from mononuclear cells from a patient with acute GVHD and deficient Con A-induced suppressor function, restored the suppressor function, demonstrating the role of monocytes for deficient Con A suppressor function in some patients with acute GVHD. Additional mechanisms of abnormal immunoregulatory functions in bone marrow transplant recipients are discussed.

Adolescent↗
PubMed1983

Monoclonal antibody defined T cell subsets and autologous mixed lymphocyte reaction in Down's syndrome.

Peripheral blood from 21 non-institutionalized children with Down's syndrome (DS) and 21 age and sex matched simultaneously studied healthy controls, was analysed for monoclonal antibody defined T cells and T cell subsets, using a fluorescence activated cell sorter, and the autologous (AMLR) and allogeneic mixed lymphocyte reaction (MLR). Total T cells (9.6+), OKT4+ (helper/inducer phenotype) and anti-Tac+ (activated T) cells were present in comparable proportions to that observed in the control group. In contrast, the proportion of OKT8+ (suppressor/cytotoxic phenotype) cells were significantly (P less than 0.05) decreased when compared to healthy controls. The proliferative response in the AMLR and MLR were comparable to control group. The significance of these results are discussed.

Antibodies, Monoclonal↗
PubMed1983

Autologous mixed lymphocyte reaction in man. VI. Deficiency of autologous mixed lymphocyte reaction in type I (insulin-dependent) diabetes mellitus.

Autologous mixed lymphocyte reaction (AMLR) was examined in the peripheral blood from 20 patients with type I (insulin-dependent) diabetes mellitus. Six of 20 patients demonstrated deficient AMLR when compared to the range for simultaneously studied age and sex matched healthy controls. The kinetics of AMLR with regard to duration of the peak proliferative response was similar to controls, the peak response being on day 6. In allogeneic MLR. T cells from patients responded normally. However, non-T cells from patients were poor stimulators against responder T cells from healthy controls. This study demonstrates a deficiency of AMLR in a subset of patients with type I diabetes that further supports an abnormal immune regulation and might be an important mechanism in the pathogenesis and autoimmune manifestations of type I diabetes.

Adolescent↗
PubMed1983

Immunological studies in patients with isolated growth hormone deficiency.

The proportion of total T cells, OKT4+ (helper/inducer phenotype) T cells and activated T cells (Tac+) in four growth hormone deficient children were compared to simultaneously studied age and sex matched healthy controls. Proportions of OKT8+ T cells (suppressor/cytotoxic phenotype), and B lymphocytes (surface immunoglobulin positive) were increased when compared to healthy controls. Increased proportion of OKT8+ T cells resulted in abnormally low ratios of OKT4+/OKT8+ cells. Proliferative response to PHA and in the AMLR were comparable to the control group. In allogeneic MLR, T cells from three of four patients responded poorly and three of four patients non-T cells stimulated poorly in MLR. Con A activated suppressor cell activity was comparable to healthy control group. This study supports the role of growth hormone in certain immune response.

Antibodies, Monoclonal↗
PubMed1983

Cellular interactions in the human T-T autologous mixed lymphocyte reaction.

Human peripheral blood T cells and T cell subsets were studied for the proliferative response in the autologous mixed lymphocyte reaction (AMLR) upon stimulation with mitogen- or AMLR-activated T cells and T cell subsets. T cells exhibited a vigorous proliferative response when stimulated with autologous activated T cells but not with unactivated T cells. The stimulatory capacity of activated T cells in the T-T AMLR was inhibited by prior treatment with 7.2 anti-DR monoclonal antibody in the absence of complement A BUdR and light experiment clearly demonstrated that T cells responding to activated T cells in the AMLR were distinct from those responding in allogeneic MLR. Further analysis with OKT4+ and OKT8+ T cell subsets demonstrated that OKT8+ T cells were the major responder upon stimulation with PHA-activated T cells. In contrast, OKT4+ T cells were the major responder in the T-T AMLR, when AMLR-activated T-cells were used as stimulators. T cells activated in T-T AMLR (PHA-activated T cells as stimulators) demonstrated suppressor activity against the proliferative response of autologous responder T cells. This study demonstrates that distinct subsets of T cells respond in the T-T AMLR and express suppressor activity.

Antibodies, Monoclonal↗
PubMed1983

Reduced capacity for DNA repair synthesis in patients with or genetically predisposed to colorectal cancer.

Peripheral resting mononuclear leukocytes were compared for their capacities to repair DNA lesions induced by a 1-hour exposure to a standardized 10-microM dose of N-acetoxy-N-2-fluorenylacetamide (N-AcO-2-FAA). Leukocytes from the following 3 groups were studied: 39 control subjects, 40 patients after colonic resection because of colorectal cancer (disease-free at the time of this study), and 28 individuals with a hereditary predisposition to colorectal cancer. Although the level of N-AcO-2-FAA that bound to mononuclear leukocyte DNA was the same for the various population groups, the level of N-AcO-2-FAA-induced unscheduled DNA synthesis (UDS) was significantly reduced in the mononuclear leukocytes of individuals who had had colorectal cancer or a genetic predisposition for the disease. These findings indicate that a deficiency in mononuclear leukocyte DNA repair synthesis is associated with the development of colorectal cancer in these populations. Our observation of this nonspecific UDS deficiency (relating to colorectal cancer) was not explained by experimental variations among the sampled groups with regard to individual differences in lymphocyte heterogeneity, age, sex, smoking habits, or blood pressure.

Acetoxyacetylaminofluorene↗
PubMed1983

Natural killer and antibody-dependent cytotoxic activities in T cell chronic lymphocytic leukemia.

T cells from a patient with T cell chronic lymphocyte leukemia (CLL) were analysed for natural killer (NK) and antibody-dependent cytotoxicity (ADCC) and surface phenotype using a battery of monoclonal antibodies. T cells from the patient reacted with a pan T cell (9.6) and OKT8 (suppressor/cytotoxic phenotype) monoclonal antibodies and bore receptors for IgG Fc (Tg) but lacked receptors for IgM Fc (Tm) and did not react with OKT4 (helper/inducer phenotype) monoclonal antibody. T cells from the patient demonstrated a significantly higher (p less than 0.01) NK activity when compared to control T cells. T cells from the patient also demonstrated strong but comparable ADCC when compared to healthy controls. The significance of these results is discussed.

Aged↗