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Biomedical subjects

A Bootello

Publications and source records attributed to A Bootello.

At least 37 records · Page 2Linked to original sources
PubMed1989

Soluble class I antigens in serum and CSF of patients with varicella-zoster virus meningitis.

Soluble class I antigens (sHLA) are secreted by lymphocytes upon activation in vitro. The intrathecal synthesis (ITS) of these molecules has been studied in patients with the varicella-zoster virus (VZV) meningitis. In this paper we describe a sHLA index IH = (CSF sHLA/serum sHLA): (CSF albumin/serum albumin) which is expected to increase only when sHLA is synthesised within the central nervous system (CNS). The IH is elevated in the first week of meningitis, when antibody synthesis is still low, and decreases thereafter. We think IH is an index of early lymphocyte activation within the CNS. The relation of these findings with previous in vitro studies is also discussed.

Herpesvirus 3, Human↗
PubMed1986

Studies on the quaternary structure of class I major histocompatibility complex antigens. Effect of different agents on the interaction between subunits.

The effect of temperature, urea, guanidine HCl, ionic and nonionic detergents, organic solvents, chaotropic salts, pH, and divalent cations has been investigated on purified human histocompatibility antigens solubilized by papain (HLApap) or solubilized by sodium cholate (HLAchol). HLApap and HLAchol are fairly stable proteins to agents acting predominantly on hydrogen bonds (temperature, urea) or hydrophobic forces (ionic and nonionic detergents). However, agents which affect ionic interactions (pH, salts, divalent cations) dissociate the molecules into subunits. A single binding site for beta 2-microglobulin with an affinity constant of 1.0 X 10(7) M-1 was found for the alpha chain of HLAchol. The dissociated subunits can be separated by affinity chromatography on Sepharose-rabbit IgG anti-human beta 2-microglobulin and reassociate in vitro when incubated under the appropriate conditions. The results point toward an important role of ionic interactions between subunits in the stabilization of the quaternary structure of HLA.

Animals↗
PubMed1985

Abnormal B cell function in haemophiliacs and their relationship with factor concentrates administration.

The present study was performed to evaluate B cell function in haemophiliacs. Spontaneous and pokeweed mitogen (PWM)-induced immunoglobulin (Ig) production was determined by ELISA in the supernatants of cultured peripheral blood lymphocytes (PBL) from 14 haemophiliacs and 17 normal donors. Spontaneous IgM, IgA and IgG production was three times higher in patients than normal controls, while PWM-induced IgM, IgA and IgG production was markedly reduced in patients compared to normal donors (P less than 0.025). Allogeneic co-cultures of haemophiliacs and normal B plus T cell fractions revealed that these results are due to a defect of the patients' T cell depleted fraction. These abnormalities were not found in three patients who had received no clotting factor concentrates for at least 1 year prior to the study. Additionally, the annual amount of clotting factor concentrates received by treated patients correlates well with the enhancement of spontaneous Ig production (r = +0.688, P less than 0.02), the decrease of PWM-induced Ig secretion (r = -0.655, P less than 0.02), and the elevation of serum IgG levels (r = +0.610, P less than 0.05). These findings suggest that the administration of clotting factor concentrates play an important role in the altered B cell function in haemophiliacs.

Adult↗
PubMed1985

Antigen-induced inhibition of human in vitro spontaneous IgE synthesis. I. Factors and kinetic studies.

Peripheral blood mononuclear cells from patients with hypersensitivity to L. perenne and D. pteronyssinus were incubated with specific antigen. They were then cultured for 7 days in the absence of antigen and the IgE contained in the supernatants was determined using an enzyme immunoassay (ELISA). Pre-incubation of the cells with antigen produced an inhibitory effect on the spontaneous IgE synthesis in most of the cases (101 of the 134 individual studied). This inhibition was more pronounced and more frequent in those cultures with an elevated spontaneous production of IgE (3,000-10,000 pg/ml). This effect depended on the dose of antigen and the duration of cell exposure. Both spontaneous IgE production kinetics and antigen-mediated inhibition were studied. A study of the IgE content of the cell pellets indicated that the antigen did not induce inhibition of the IgE release. We therefore believe that the inhibition observed must be due to some kind of IgE synthesis suppression.

Allergens↗
PubMed1984

EGG hypersensitivity as measured by RAST and a reverse enzyme-immunoassay.

The application of a reverse enzyme-immunoassay (REIA) to measure specific anti-egg IgE is described. The results obtained with the REIA and the RAST are shown. The REIA is economical, easy and fast to perform when the conjugate has been made, non-radioactive and offers a new alternative for the in vitro evaluation of egg white-specific IgE.

Antibody Specificity↗
PubMed1984

Disorders of regulatory T cell function in patients with the Wiskott-Aldrich syndrome.

Three patients with the Wiskott-Aldrich syndrome were studied. One of them had no past history of relevant infections. The other two presented different degrees of humoral and cellular immunodeficiency and their T cells in vitro showed a defect in regulatory activity of Ig production in PWM stimulated cultures. This defect was not observed in the third patient. All three had normal numbers of B cells, producing normal amounts of Ig in vitro when co-cultured with normal T cells. It is suggested that the immunoregulatory T cell abnormality might play an important role in the pathogenesis of the humoral immunodeficiency.

B-Lymphocytes↗
PubMed1983

Use of the ELISA to detect and quantify histocompatibility antigens and their subunits.

A solid phase enzyme immunoassay (ELISA) has been developed for the detection and quantification of human histocompatibility antigens and their subunits. The assay involves the binding to a microELISA plate of a mouse monoclonal antibody reacting with a common antigenic determinant to all HLA (A, B, C) antigens. The standard conditions for the assay and the curves obtained for the quantification of total HLA, free beta 2m, and free heavy chain subunit (alpha) present in a biological sample are described and the sensitivity and potential uses of the method are discussed.

Animals↗
PubMed1983

Modulatory effect of hydrocortisone on T-lymphocyte regulatory activity in pokeweed mitogen-driven Ig production.

The effect of hydrocortisone (HCO) on pokeweed mitogen (PWM)-driven Ig production from human tonsil B- plus T-lymphocyte cocultures was analyzed. IgM and IgG production decreased in cultures with a B/T ratio of 10/1 or higher (P less than 0.001) and increased in cultures with a B/T ratio of 1/1 or lower (P less than 0.01) when 10(-5) M HCO was added. Similar effects were observed on Ig production from peripheral blood lymphocyte cultures. These effects were only obtained at the HCO doses of 10(-5) and 10(-6) M, and no modifications by monocyte depletion were observed. The function of HCO-pretreated B cells did not differ from that of control B cells when cocultured with fresh T cells. However, the HCO pretreatment of T cells before coculturing with fresh B cells affected the Ig production in the same way as the addition of the drug to fresh cocultures. These results suggest that HCO modulates the PWM-driven Ig production by affecting helper and suppressor T-cell activity.

Antibody Formation↗
PubMed1983

Reverse enzyme immunoassay for the determination of Dermatophagoides pteronyssinus IgE antibodies.

Sera from patients with suspected mite sensitivity were assayed using both the radioallergosorbent test (RAST) and a reverse enzyme immunoassay for IgE antibodies (REIA). Of the 133 sera studied, the RAST gave positive results in 48 cases and the REIA in 59. Negative results for both assays were obtained in 72 of the sera. The immunoenzymatic assay described here, using micro-plates as solid phase, has proven to be IgE- and antigen-specific. The allergen conjugate has a prolonged shelf life and the method is easy to perform. The sensitivity of the REIA for Dermatophagoides pteronyssinus IgE antibodies is limited by the small amount of IgE bound by the well surface (less than 100 ng). However, we think that the method offers a reliable alternative for the diagnosis of D. pteronyssinus-allergic patients.

Animals↗
PubMed1983

Reverse enzyme immunoassay for the determination of Lolium perenne IgE antibodies.

A microplate enzyme-immunoassay technique for the detection of specific anti-Lolium perenne IgE antibodies is described. This method consists of coating polystyrene wells with goat antihuman IgE (epsilon chain specific) and late selecting the IgE from the patients serum in order to finally reveal the bound specific IgE by means of a crude L. perenne extract conjugated with peroxidase. The optimal conditions necessary to achieve maximum sensitivity and specificity using this system have been studied. After testing 98 sera, the results showed a 97.9% correlation between our technique and the RAST.

Antibodies↗
PubMed1982

Disorders of regulatory T cells in patients with selective IgA deficiency and its relationship to associated autoimmune phenomena.

In vitro lymphocyte function of 13 patients with selective IgA deficiency was studied. IgG, IgA and IgM secretion by pokeweed mitogen-stimulated peripheral blood lymphocytes from normal donors and IgA deficient patients was measured by an enzyme-linked immunosorbent assay. Addition of concanavalin A or hydrocortisone and co-cultures of B and T cell enriched populations from patients and normal donors, allowed us to investigate B cell Ig production and T cell regulatory abnormalities. IgA production by these patients' B cells was either absent or very low, as compared to their total Ig production, even in the presence of optimal T cell help. Several T cell immunoregulatory abnormalities were seen in different patients. A moderate increase in suppressor activity selective for IgA production was observed in some, but does not appear to play a major role in the pathogenesis of the IgA deficiency. In others, with associated autoimmune phenomena, a decrease in suppressor T cell function was found.

Adolescent↗
PubMed1982

B cell hyperactivity and abnormalities in T cell markers and immunoregulatory function in a patient with nucleoside phosphorylase deficiency.

We describe a 2 year old girl with nucleoside phosphorylase (PNP) deficiency, who had low blood T cell numbers and T lymphocyte blastogenic response to mitogens, hypergammaglobulinaemia, high titres of antibodies to many common antigens, various autoantibodies, a monoclonal IgM-kappa protein, an increased frequency of mature Ig containing blood B cells and a high production of Ig in vitro in unstimulated cultures. E rosetting cells showed faint or no immunofluorescence staining with monoclonal antibodies directed against T cell membrane antigens. In vitro Ig production in response to pokeweed mitogen was defective, and no T cell helper or suppressor activity was observed. It is suggested that the immunoregulatory deficiency might have caused the B cell hyperactivity.

Antibodies↗
PubMed1982

[Circulating immune complexes in the serum of tumor patients].

The conditions for the detection of circulating immune complexes (CIC) were established by combination of polyethylene glycol precipitation with a nephelometric determination on the precipitate of endogenous C1q. The CIC precipitated from the sera of patients with breast carcinoma, malignant melanoma or autoimmune diseases were dissociated in SDS-beta-mercaptoethanol buffer and no differences were observed in the electrophoretic patterns os polyacrylamide gels allowing to characterize tumour specific antigens.

Antigen-Antibody Complex↗
PubMed1982

Functional assessment of T and B lymphocytes in patients with selective IgM deficiency.

Two patients with selective IgM deficiency were studied. Both presented with dermatitis, chronic diarrhoea, recurrent respiratory infections, failure to thrive, elevated serum IgE levels and in vivo impairment of antibody production. No phagocytic or complement abnormalities were found. B lymphocytes with surface IgM were present in normal or high percentage in peripheral blood, and produced normal amounts of IgM in vitro when co-cultured with normal T cells. Patients' T cells did not show excess suppressor function in vitro but had a decreased helper activity for IgM, IgG and IgA production. It is suggested that both patients have an extensive humoral immune deficiency that might be caused by the immunoregulatory T cell defect.

B-Lymphocytes↗
PubMed1981

Linkage of GLO with HLA in a sample of the Spanish population.

GLO allele frequencies are studied in 100 unrelated normal Spaniards. GLO-S shows a frequency similar to that found in Caucasoids. Weak linkage disequilibria between some HLA-B and some HLA-DR antigens are described. DR3 and DR4 are GLO-F associated both in normal and insulin dependent diabetic Spaniards. GLO/HLA-DR loci distance is about 6cM according to our family studies; females show a higher GLO/HLA-DR recombination rate than males in our sample. NO GLO heterozygous excess or "nul" alleles are found.

Adult↗