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Biomedical subjects

C Piccardo

Publications and source records attributed to C Piccardo.

9 recordsLinked to original sources
PubMed1996

HIV-1 and hepatitis B virus infections in adolescents lodged in security institutes of Buenos Aires.

The goal of this study was to determine the prevalence of human immunodeficiency virus type 1 (HIV-1) and hepatitis B virus (HBV) infections in street youth lodged in security institutes, from February 1992 to March 1995, to correlate these infections with nontherapeutic drug use, and to compare these results with a previous study done in a similar population. A total of 1460 white adolescents, 276 females and 1184 males, were enrolled (mean age 16.6 years). Prevalence of HIV-1 was 4.58% and of HBV was 6.78%. The prevalence of dual HIV-1/HBV infection was 1.91%; the prevalence of HBV infection was significantly higher in HIV-positive subjects (p < 0.0000000, chi 2 = 136.17, OR = 13.37) than in those not infected with HIV-1. Prevalences were higher in males. Intravenous drug addiction proved to be a significant risk factor for both viruses (HIV-1, p < 0.0000000, chi 2 = 171.34, OR = 16.84; HBV, p = 0.000044, chi 2 = 16.67, OR = 3.17); 6.43% of the total population were intravenous drug users. Comparison of the current results with our previous study (1989-1992) showed that the prevalence of HIV-1, HBV, and concurrent HIV/HBV as well as intravenous drug addiction has decreased significantly in our current cohort (chi 2 = 134.85, p < 0.0000000; chi 2 = 126.62, p < 0.0000000; chi 2 = 110.05, p < 0.0000000; and chi 2 = 158.3, p < 0.0000000) respectively. Progress appears to have been made in the fight against acquired immunodeficiency syndrome (AIDS), and promising results have been obtained. However, if further viral spread is to be avoided, the emphasis on prevention should be energetically maintained.

Adolescent↗
PubMed1987

Effects of a new heterocyclic glucocorticoid, deflazacort (DFC), on the functions of lymphocytes from patients with rheumatoid arthritis (RA).

Deflazacort (DFC) is a new glucocorticoid which, when compared with prednisone (PDN), has similar anti-inflammatory actions, but lacks several unwanted side effects on mineral and carbohydrate metabolism. DFC is more efficient than PDN in inducing immunomodulatory effects. This study concerns twelve patients with classical RA who required corticosteroid therapy because of the ineffectiveness of other drugs. Six patients received 12 mg/day of PDN from day 1 to day 21 and 15 mg/day of DFC from day 29 to day 50. The second group of six patients received DFC initially followed by the PDN dosing regimen. At various times (4, 8, 24, 48 and 72 h) after the first administration of steroid, and 7, 14 and 21 days after the beginning of the treatment with PDN or DFC the following tests were performed the phenotype of T lymphocytes isolated from peripheral blood; the evaluation of the expression of HLA Class 2 antigens by PHA primed T cells; and the analysis of cell behavior in mixed lymphocyte reactions. The data reported in this paper show that the oral administration of DFC to patients with RA affects the in vitro behavior of their lymphocytes. This immunomodulatory effect of DFC concerns both the phenotype and function of RA lymphocytes. Moreover it differs in both intensity and kinetic characteristics from the immunomodulating effect observed with PDN (control).

Arthritis, Rheumatoid↗
PubMed1985

Analysis of the role of xenogeneic antigens in the proliferation of human T cells stimulated with autologous non-T cells and phytohemagglutinin-activated T cells.

Since conflicting results have been reported about the role of xenoantigens in the proliferation of T cells stimulated with autologous non-T cells, the effect of the exposure of cells to xenogeneic proteins during the isolation procedure and/or the culture period on autologous mixed lymphocyte reactions (AMLR) with non-T cells and phytohemagglutinin-activated T cells as stimulators was investigated. T and non-T cells were isolated by rosetting with 2-aminoethylisothiuronium bromide-treated sheep red blood cells (AET-SRBC), by nylon-wool filtration, and by positive or negative selection with anti-class II HLA antigens and anti-T-cell monoclonal antibodies. Isolation and cultures were performed in presence of fetal calf serum (FCS) or of autologous serum. In both types of AMLR, proliferation of responding cells did not require exposure to xenoantigens. However xenoantigens enhanced the proliferation of cells from some, although not all, the donors tested. There were differences in the degree of proliferation of the cells from the donors tested, but without correlation with the two types of AMLR. These results suggest that both types of AMLR reflect a self-recognition event and not a response to xenoantigens. However the potential interference of xenoantigens, as well as the individual variability, should be taken into account when interpreting the significance of abnormalities of AMLR in immunopathologic processes.

Antibodies, Monoclonal↗
PubMed1985

T-lymphocytes phenotype and functions in patients with head and neck cancer.

We studied the phenotype of T-lymphocytes isolated from 18 patients with head and neck cancer, their capacity to express Ia antigens upon activation by lectins in vitro, their capacity to function either as responder or stimulator cells in autologous mixed lymphocyte reaction, and their capacity to cooperate with the normal adherent suppressor cells (NASC). The T-lymphocytes isolated from these patients have several functional defects including an impaired capacity to activate allogeneic lymphocytes in mixed lymphocyte reactions (MLRs), a lack of a proliferative capacity in autologous MLRs, an impaired sensitivity to inhibition by NASC, and an impaired capacity to express Ia antigens upon activation by mitogens in vitro. These data indicate that, in patients with head and neck cancer, immune function is characterized by a defect in T-lymphocytes functions which concerns the process of cell to cell cooperation.

Aged↗
PubMed1984

Human T cells in cord blood: abnormalities in IA antigens induction by phytohemagglutinin and in autologous mixed lymphocyte reactions.

About 25% of human T cells isolated from cord blood acquired la antigens, following stimulation with phytohemagglutinin (PHA) for 72 hr. This percentage is markedly lower than that found in PHA-activated T-cell populations (PHA-T cells) isolated from peripheral blood of adults. The low expression of la antigens by human T cells from cord blood does not reflect abnormalities in the sensitivity to PHA stimulation and/or in the kinetics of induction of la antigens. PHA-T cells from cord blood display a low stimulatory activity in autologous mixed lymphocyte reactions (MLR). The defect does not reflect a nonspecific abnormality in the stimulatory activity of PHA-T cells from cord blood, since the latter do not differ from PHA-T cells from adults in their ability to stimulate allogeneic T cells from adults. Furthermore the defect does not reflect a nonspecific abnormality in the proliferative response of T cells from cord blood, since the latter display a normal proliferative response to PHA-T cells from adults. The defect in the proliferative response is not restricted to the autologous MLR with PHA-T cells, since it was found also in autologous MLR with non-T cells as stimulators. Correlation of the temporal evolution of the abnormalities of human T cells with the maturation of the immune system may contribute to our understanding of the role of la antigens in cell-cell interactions and of the biological significance of abnormalities of autologous MLR.

Cells, Cultured↗
PubMedDate not supplied

[Molecular analysis of the principal neutralization epitope (V3 loop) of human immunodeficiency virus type 1 in Argentina].

The main goal of the present paper was to analyze the molecular diversity of the principal neutralizing domain (V3 loop) of the HIV 1 gp120 in samples from patients of Argentina. The study was carried out on a total of 30 HIV 1 positive blood samples, obtained during 1991-1992, belonging to 15 intravenous drug users (group A), 5 homosexual men (group B), 8 children born to HIV 1 positive mothers (group C) and 2 AIDS patients (group D). By using extracted DNA from peripheral blood lymphocytes and from infected cells of the viral isolates in the case of the 2 AIDS patients, the V3 loop region was amplified by means of polymerase chain reaction. Direct sequencing by Sanger methodology was then performed on DNA fragments and nucleotide sequences obtained were translated into the correspondent amino acids. Consensus sequences for each group and a general consensus sequence were established (Table 1). Its alignment with V3 loop amino acid sequences of the major HIV 1 strains isolated worldwide is showed in table 2. Homology analysis between each sequence of the study population and sequence of different HIV 1 isolates showed that most of these samples share high homology with SF2 and BH10 strains. In contrast a low homology was found with JH3 and MN isolated (table 3). The presence of highly conserved amino acid residues as substitutions and insertions was determined in the Argentinian V3 loop sequences giving them a local pattern. The present paper is of great importance for our country, considering that the V3 loop is the main neutralizing domain becoming a major target in the development of HIV 1 vaccine. To our knowledge, this is the first report on the sequencing of the principal neutralizing domain of the Human Immunodeficiency Virus type 1 in Latin America.

Acquired Immunodeficiency Syndrome↗