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Biomedical subjects

A Bertotto

Publications and source records attributed to A Bertotto.

At least 91 records · Page 5Linked to original sources
PubMed1985

Sézary's syndrome: a case with blood T-lymphocytes of helper phenotype, elevated IgE levels and circulating immune complexes.

A patient with Sézary's syndrome is described. Surface marker analysis of her peripheral blood lymphocytes exhibit a phenotype characteristic of mature helper T cells (OKT3+, OKT4+, OKT8-, OKT6-). Serological studies revealed a polyclonal hyperimmunoglobulinemia with large amounts of IgE and IgA and circulating immune complexes that activate the complementary system via alternative pathway. The patient's cells showed a helper activity on normal B cell differentiation after a 7-day co-culture with pokeweed mitogen. The relevance of this helper phenotype and the function on in vivo polyclonal B cell activation is discussed.

Aged↗
PubMed1985

Plasma cell generation inhibition in lymphocyte cultures containing cerebrospinal fluid from children with central nervous system viral infections.

Plasma cell generation in pokeweed mitogen-pulsed lymphocyte cultures was markedly suppressed when the experiments were carried out by adding cell-depleted cerebrospinal fluid (CSF) from 5 acute aseptic meningitis or meningoencephalitis children known to have an overexpanded cell population with the suppressor-cytotoxic T-cell surface phenotype in their CSF. In contrast, B-cell terminal differentiation was not affected by the addition of CSF from 5 control children with non-neurological diseases, thereby indicating that CSF from central nervous system virus-infected children contains soluble factors which are themselves capable of exerting regulatory influences on immunocompetent cells.

Adolescent↗
PubMed1984

Immunoregulatory T cells in measles. The relationship between reduced lymphocyte proliferative response to PHA and increased proportion of circulating suppressor-cytotoxic T cells.

Viral infections are often associated with immunodeficiency states. Although T lymphocytes have been thought to suppress the host's immune response, the precise cellular basis for this phenomenon remains unclear. Therefore, we characterized peripheral blood mononuclear cells from 9 measles virus-infected children by means of monoclonal antibodies directed against surface antigens expressed on human T lymphocytes and T-cell subsets. In addition, the measles lymphocyte blast transformation response to the T-cell mitogen phytohaemagglutinin (PHA) was evaluated as an index of specific T-cell immunocompetence. During the course of measles, there was a slight reduction in the proportion of total circulating T cells, with a relative decrease in helper-inducer and a parallel increase in suppressor-cytotoxic T lymphocytes. The PHA lymphocyte blastogenic response was found to be defective in children with measles and, interestingly, there was a significant negative correlation between the reduced PHA blast transformation value and the increased proportion of suppressor-cytotoxic cells. The biological implications of these finding with respect to the underlying immunopathology of the measles virus infection are discussed.

Antibodies, Monoclonal↗
PubMed1984

Lymphocyte surface phenotypes in Down's syndrome.

The lymphocyte surface phenotypes in the blood of 7 non-institutionalized adults with trisomy-21, and in 10 karyotypically normal control subjects, were analysed by fluorescent microscopy with an OKT series of monoclonal antibodies. Whereas the proportions of OKT3+, OKT4+ and OKT6+ cells were similar in the two groups, the percentages of both OKT8+ and OKT10+ trisomic lymphocytes were significantly higher. The biological implications of these findings with respect to the underlying immunopathology of Down's syndrome are discussed.

Adult↗
PubMed1984

Phenotypic analysis of T cell subsets in the blood of chronically aborting women.

A relative decrease in helper and a parallel increase in suppressor-cytotoxic T lymphocytes was found in the blood of six habitually aborting women, as compared with the T-cell subset distribution in ten normal multiparae and eight multigravid post-partum women. It is suggested that an imbalance between the immunoregulatory T-cell subpopulations may contribute to the rejection of the semiallogenic fetus.

Abortion, Habitual↗
PubMed1984

Lymphocyte surface antigens: a longitudinal study during the first month of human life.

A longitudinal study on human T lymphoid surface antigens was performed on blood samples from 6 infants during their first month of life. Although the results indicate a sudden increase in the percentage of OKT3+ and E-RF+ cell types a few hours after birth and a less rapid decrease of OKT6+ and OKT9+ circulating cells, high levels of OKT10+ cells persisted. This finding suggests that infant blood contains immature phenotypic T lymphocytes after birth.

Age Factors↗
PubMed1983

Monoclonal antibody-defined T-cell surface phenotypes in human breast milk.

The distribution of T-lymphocyte subsets in human early milk was determined by immunofluorescence analysis of reactivity with monoclonal antibodies of the OKT series. A novel finding was that the T-lymphocyte population in human milk contains both OKT4 (helper/inducer phenotype) and OKT8 (suppressor/cytotoxic phenotype)-positive subsets. The relative ratio of OKT4 to OKT8-positive T-cell subsets in milk, however, was generally higher than that observed for peripheral blood T cells.

Female↗
PubMed1983

Serum migration inhibitory activity and monoclonal antibody-defined T-cell phenotypes in patients with acute infectious mononucleosis.

Previous experiments in our laboratory have demonstrated that circulating endogenous leucocyte (migration) inhibitory factor (serum LIF), or a lymphokine with LIF-like activity, may be involved in the impaired cellular immune response observed during the acute phase of the Epstein-Barr virus (EBV) induced infectious mononucleosis (IM). To determine whether serum LIF activity is associated with immunoregulatory IM T-cell subset abnormalities, we analyzed the peripheral blood T-cell populations in a series of acute serum LIF-positive and LIF-negative IM patients by means of T-lymphocyte-specific monoclonal antibodies. Although there was both activation and increase of suppressor/cytotoxic T cells in all IM patients sampled in the acute stage, the relative and absolute numbers of suppressor lymphocytes were found to be significantly higher in those who had LIF activity in their serum. It is postulated that EBV infection can preferentially activate a specific T-cell subpopulation which, in its turn, inhibits the overall host immune response, possibly by a LIF-induced feedback suppression mechanism.

Antibodies, Monoclonal↗
PubMed1983

"In vitro" and "in vivo" leukocyte migration inhibitory factor production in acute infectious mononucleosis patients.

Since infectious mononucleosis (IM) mononuclear cells spontaneously release the leukocyte (migration) inhibitory factor (LIF) in culture and since previous experiments in our laboratory have demonstrated that one or more substances with LIF-like activity are detectable in the serum (serum LIF) of young patients with heterophile-positive IM, an investigation was carried out to determine both the in vitro and in vivo LIF production in a series of IM patients sampled during the acute phase of the infection. The observation than only the unstimulated lymphocytes from serum LIF-positive IM patients released LIF in culture suggests that a single active product is involved in the in vitro and in vivo LIF activities observed in Epstein-Barr virus (EBV) infected subjects. The biological implications of this finding with respect to the underlying immunopathology of the EBV IM syndrome are discussed.

Adolescent↗
PubMed1983

The in vivo effect of thymic factor (thymostimulin) administration in Hodgkin's disease patients. Correlation of skin reactivity and leukocyte migration-inhibition factor in the sera of anergic subjects.

The correlation between leukocyte migration-inhibition and delayed skin hypersensitivity was studied in the sera of 15 anergic untreated Hodgkin's disease patients before and after administration of thymostimulin. Skin tests, negative in all patients before treatment, turned positive in 9 after thymostimulin. Prior to treatment, 10 patients had normal and 5 enhanced migration; none was leukocyte migration-inhibition factor (LIF) positive (mean 1.14 +/- 0.30). Seven of the 9 patients (77.9%) whose skin tests became positive, 3 of whom had an initially enhanced migration, were LIF positive after thymostimulin. LIF closely paralleled skin hypersensitivity both before and after thymostimulin. It is suggested that thymostimulin evokes the differentiation of a lymphocyte subpopulation(s) responsible for both factors investigated.

Cell Migration Inhibition↗
PubMed1982

The in vivo effect of a thymic factor (thymostimulin) on immunologic parameters of patients with untreated Hodgkin's disease.

The in vivo effect of a calf thymus extract (thymostimulin, TS) on the E-rosetting capacity, PHA blastogenic response, serum migration inhibitory activity (LIF) and skin reactivity to recall antigens was evaluated in 19 untreated patients with Hodgkin's disease. In patients the mean percentage of peripheral blood lymphocytes forming E-rosettes increased from 47 to 55.7% (P less than or equal to 0.001; normal: 58.9). The mean PHA stimulation index rose with all three concentrations tested but did not reach normal values. Serum LIF was positive in only one patient prior to treatment with a mean LIF for all patients of 0.75 (P less than or equal to 0.005). Skin tests were positive in ten patients (52.6%) prior to therapy and 18 patients following therapy (94.7%; P less than or equal to 0.05). Thymostimulin, in vivo, appears to return immunologic competency to a population of untreated patients with Hodgkin's disease.

Adult↗
PubMed1982

Leucocyte migration-inhibitory activity in human cord blood.

Leucocyte migration-inhibitory activity was found in the sera (cord blood) of 15/28 (53%) healthy, fullterm newborn infants as opposed to only 3/28 (10,7%) control children under three years of age (P less than 0,005). It is postulated that the migration-inhibitory activity may be related to lymphokine-dependent mechanisms.

Child, Preschool↗