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Biomedical subjects

R Paganelli

Publications and source records attributed to R Paganelli.

At least 127 records · Page 7Linked to original sources
PubMed1983

Heterogeneity of immunological abnormalities in ataxia-telangiectasia.

Peripheral blood mononuclear cells from five patients with ataxia-telangiectasia were evaluated for their reactivity with a panel of monoclonal antibodies directed against T-cell subsets and for their in vitro functions in a pokeweed mitogen-induced immunoglobulin biosynthesis assay. All the patients had significantly reduced proportions of cells identified by monoclonal antibodies to subpopulations of T lymphocytes with helper activity (OKT4 and 5/9) and produced low amounts or no IgA and IgG in vitro. Immunoglobulin biosynthesis was increased by the addition of normal x-irradiated peripheral blood mononuclear cells in one of three patients, suggesting a helper T-cell deficiency in this patient and intrinsic B-cell defects in the other two. Two patients had increased proportions of cells identified by a monoclonal antibody to a subpopulation of T lymphocytes which includes suppressor T cells (OKT8), and their cells were able to suppress immunoglobulin biosynthesis by peripheral blood mononuclear cells from normal donors. These findings indicate heterogeneous disturbances of immunoregulatory mechanisms in ataxia-telangiectasia.

Adolescent↗
PubMed1983

Differences between normal and milk allergic subjects in their immune responses after milk ingestion.

In order to understand why non-atopic people do not have adverse symptoms to food antigens which enter the circulation after eating, 8 non-atopic and 10 atopic eczema- and milk-allergic subjects were challenged with milk, and the types of circulating immune complexes formed were analysed. Although the amount of beta-lactoglobulin incorporated into complexes did not differ statistically between the groups, the type of immune complex did. Of the non-atopic individuals, 5 formed IgA and 2 IgG complexes. Of the milk-allergic group, all showed a rise in at least one type; 5 formed IgA, 7 IgG, 6 IgE, and 6 formed C1q-binding complexes. Our data suggest that serum IgA is concerned in safe food antigen handling in non-atopic people, and that the differences in the type of immune complexes formed in response to antigen challenge may underlie the systemic symptoms of food allergy.

Adolescent↗
PubMed1983

A placebo-controlled trial of thymic hormone treatment of recurrent herpes simplex labialis infection in immunodeficient hosts.

Twenty-one immunodeficient patients with recurrent herpes simplex labialis (HSL) were randomly allocated to either saline or the bovine thymus extract thymostimulin (TS) and treated for a period of 6 months. An impressive reduction in both number and severity of the recurrences of the infection was observed in TS-treated patients during the trial and for up to 3 months afterward. A significant increase in total WBC, lymphocyte count, and T cells was detected in the TS group after 6 months. In vitro lymphoproliferative responses to herpes simplex virus antigen and natural killer cell activity were also significantly higher in the TS group, whereas no significant difference in antibody titers to herpes simplex could be detected between the two groups. TS can therefore help prevent viral reactivation in immunocompromised hosts by potentiating cell-mediated immune responses and should be considered for use in prophylaxis of infection in patients at risk and also in apparently normal subjects with recurrent HSL.

Adolescent↗
PubMed1983

Impaired production of interleukins in patients with cell-mediated immunodeficiencies.

The poor mitogen response to phytohaemagglutinin (PHA) of lymphocytes from three patients with cell-mediated immunodeficiencies was restored to normal when supernatants containing interleukin 2 (IL-2) were added. One of three children with severe combined immunodeficiency also showed a partial response. There was no improvement in the normal mitogenic response of the lymphocytes from patients with either the X linked or common variable forms of hypogammaglobulinaemia. All three patients with cell-mediated immunodeficiencies showed gross imbalance in the ratio of helper/inducer (OKT4+) to suppressor/cytotoxic (OKT8+) T cells. The PHA stimulated culture supernatant from one of these patients failed to induce proliferation of a cytolytic continuous T cell line. Our data suggests that the underlying defect in these patients may be a failure in production of interleukins but not in the acquisition of IL-2 receptors.

Adult↗
PubMed1983

Food allergy and gastrointestinal diseases.

Several gastrointestinal diseases and symptoms have been attributed to food intolerance, but in only a few cases has the participation of immune mechanisms been confirmed. Acute or chronic gastroenteritis is commonly due to allergic reactions to food proteins, inflammatory diseases and infections, or the presence of immunological defects may induce secondarily a food allergic disorder. This review will focus on the immunopathogenetical importance of the mucosal and systemic defenses, and the absorption of food proteins by the gut.

Angioedema↗
PubMed1983

Intestinal antigen handling at mucosal surfaces in health and disease: human and experimental studies.

Intestinal uptake of antigenically intact food proteins was measured by a solid phase radioimmunoassay on serum samples after instillation of food proteins into a closed intestinal loop of adult Wistar rats. Compared to normal controls, rats fed protein deficient diets during five months had a higher macromolecular uptake. During the course of Nippostrongylus brasiliensis infection this uptake was decreased. In cholera toxin induced secretory states of the intestinal mucosa uptake of food proteins was increased. In human studies the uptake of Beta-Lactoglobulin after a milk meal was shown to be increased in premature compared to full-term neonates. In children suffering from intestinal helminth infection the macromolecular uptake was higher before treatment compared to that after treatment. These studies show that various pathological situations can alter the antigen handling at mucosal surfaces.

Adolescent↗
PubMed1982

Milk antigen absorption in the preterm and term neonate.

The concentrations of beta-lactoglobulin was measured in the sera of 47 preterm an term neonates during the first few days of life under standardised conditions after feeding with a cows' milk'based formula. Preterm neonates, particularly those of less than 33 weeks' gestation, had higher serum concentrations of beta-lactoglobulin than term neonates given an equivalent mild feed. Prior feeding with breast milk did not diminish the amount of beta-lactoglobulin absorbed. Our results suggest tha te ability of the gastrointestinal tract to exclude antigenically intact food proteins increases with gestational age and that gut closure occurs normally before birth in man.

Breast Feeding↗
PubMed1981

Differences in specific antibody responses of human tonsillar cells to an oral and a parenteral antigen.

Tonsillar lymphocytes stimulated in vitro with either beta-lactoglobulin or with tetanus toxoid were shown to produce specific antibodies by a direct plaque assay and by radioimmunoprecipitation of the culture supernatants. There was a sixfold increase in the number of IgA-secreting cells in response to beta-lactoglobulin; no such effect was seen in response to tetanus toxoid, where a fivefold rise in IgG-secreting cells occurred. These differences in antibody response are probably due to the route of initial antigen presentation. Those antigens priming the mucosa-associated lymphoid system stimulate mainly IgA-producing cells, in contrast to parenteral antigens, which elicit a predominantly IgM and IgG response.

Administration, Oral↗
PubMed1981

Specific antigen exclusion and non-specific facilitation of antigen entry across the gut in rats allergic to food proteins.

The intestinal absorption of ovalbumin and beta-lactoglobulin was measured in Hooded Lister rats which had previously been made allergic to ovalbumin, and in unimmunized controls. The antigens were introduced both together and separately into closed intestinal loops. Absorption of free ovalbumin, but not beta-lactoglobulin, was reduced in rats with anti-ovalbumin antibody, demonstrating antigen-specific immune exclusion despite the presence of reaginic antibody. In contrast, the absorption of beta-lactoglobulin was enhanced by the presence of ovalbumin in rats with IgE anti-ovalbumin, but not in unimmunized controls. These results suggest that macromolecular absorption may be increased in an antigen non-specific way in food allergy.

Animals↗
PubMed1981

Detection of specific antigen within circulating immune complexes: validation of the assay and its application to food antigen-antibody complexes formed in healthy and food-allergic subjects.

A simple two-step method for the detection of specific antigen within immune complexes is described. The immune complexes are precipitated from serum by polyethylene glycol, dissociated by incubation in acid pH buffer and adsorbed onto the surface of polystyrene tubes. The antigen is detected by the binding of a radiolabelled affinity-purified specific antibody. The assay can detect the antigen within both antigen- and antibody-excess immune complexes of any immunoglobulin class, and can also allow semiquantitative comparison of different samples. Immune complexes containing food protein antigens after eating have been found in the serum of both normal subjects and atopic patients; the latter group showed higher mean levels of antigen-specific immune complexes. The method can be adopted for large-scale screening of clinical samples for suspected antigens if suitable antisera are available.

Adult↗
PubMed1980

Solid phase radioimmunoassay for detection of circulating food protein antigens in human serum.

A two site solid phase radioimmunoassay for detection of common food antigens is described. Bovine serum albumin, beta-lactoglobulin and ovalbumin can be detected in normal human serum at levels ranging from 0.1 to > 1000 ng/ml; sensitivity is not impaired by the presence of low levels of antibodies. Thirty min to 3 h after oral intake of milk, beta-lactoglobulin could be detected in the sera of 3 normal individuals, at a concentration of 0.1-3 ng/ml. This assay should prove useful in assessing the importance of macromolecular absorption in food allergy and in other gastrointestinal diseases.

Adult↗
PubMed1980

Circulating immune complexes in onchocerciasis.

Circulating immune complexes were detected in sera of patients with both localized and generalized onchocerciasis by a 125I-Clq binding assay but not by the IgG latex agglutination inhibition method. Gel filtration of sera demonstrated high molecular weight Clq-reactive material(greater than 2 x 10(6) Daltons) which contained IgM but no IgG. Antibody titres to Onchocerca volvulus antigen were higher in patients with generalized disease than in those with the localized form. The lack of correlation between antibody titres and levels of immune complexes suggests that these immune complexes contain antigens other than those derived exclusively from the parasite. Although few of the symptoms of this disease are likely to be due to deposition of circulating immune complexes, the depression of delayed hypersensitivity reactions to the parasite found in patients with generalized onchocerciasis may be due to IgM immune complexes exerting an immuno-regulatory role on T cell function.

Adolescent↗
PubMed1979

Mouse rosette forming cells and surface immunoglobulins in human lymphoid cells.

Peripheral blood lymphocytes from normal subjects were studied for mouse rosette-forming cells (MRFC) and their relationship to surface immunoglobulins (SIg). The majority of MRFC expressed both SIgM and SIgD, although some dissociation between population showing SIgM+/MRFC- and SIgM-/MRFC+ could be seen. A similar pattern of association was found in human derived cultured cells of B lineage, but no simple correlation and the number of SIgM+ cells could be established. Increased percentages of MRFC were detected in two foetal livers but greater dissociation of MRFC and SIgM was shown. This heterogeneity of MRFC may be explained by a selective expression of this surface marker in the early stages of B lymphocyte differentiation.

Animals↗