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Biomedical subjects

C Mancini

Publications and source records attributed to C Mancini.

At least 91 records · Page 5Linked to original sources
PubMed1987

Age restriction in antigen-specific immunosuppression.

Age-related alterations of antigen-specific T cell-mediated suppression have been examined in the 4-hydroxy-3-nitrophenyl acetyl (NP) system. Inducer suppressor T cells (Tsi) were activated in mice at the age of 3 mo (young) or 18 mo (old) by i.v. injection of NP-conjugated syngeneic spleen cells (SC). Spleen cells from the NP-SC-injected mice were subcultured in vitro with spleen cells from normal young or old mice to generate transducer suppressor T cells (Tst). Four days later subcultured cells were added to responder cell cultures 1 day before the PFC assays to trigger effector suppressor T cells (Tse). Responder cell cultures, containing NP-conjugated horse red blood cells (HRBC) and spleen cells from HRBC-primed young or old mice, were assayed on day 4 for anti-NP and anti-HRBC PFC. Suppression was found to be antigen specific and age restricted. NP-specific suppressor cells are easily induced in subculture if the Tsi and Tst cell populations are both derived from young or old mice. Conversely, if Tsi cells from young or old mice are subcultured with Tst cells from mice of a different age, suppression of the anti-NP PFC response is hardly observed. Age restriction was also found to operate in the interactions between subcultured and responder cell populations, indicating that age-matching is required for effective triggering of Tse cells by Tst cells. These results altogether suggest that aging may affect the recognition repertoire expressed in suppressor T cell subsets. Moreover, the finding that suppression is less efficient when exerted on responder spleen cells from old than from young mice provides an explanation for the increased frequency of autoimmune disorders in aging.

Aging↗
PubMed1987

Membrane interactions involved in the induction of interferon-alpha by Mycoplasma pneumoniae.

Interferon (IFN) induction by Mycoplasma pneumoniae (MP) in human peripheral blood mononuclear cells (PBMC) has been studied. We show that IFN yields depend on the concentration of both lymphocytes and MP. The effective IFN inducer appears to be the mycoplasma membrane, and IFN production occurs without significant lymphocyte proliferation. Data obtained by both positive and negative selection experiments suggest that the PBMC subpopulation induced by MP is B lymphocyte, as opposed to the main subpopulation induced by NDV that is monocyte. Evidence is also provided suggesting that the membrane interaction between MP and the B cells is mediated by MHC Class II antigens.

B-Lymphocytes↗
PubMed1987

[Seroepidemiologic studies in 63 patients given organ transplants in relation to cytomegalovirus, herpes simplex, varicella-zoster and HTLV-III: validity and limits].

We carried out a seroepidemiological study on 63 patients undergoing organ transplantation in order to determine viral markers like CMV, HTLV III, HS and V/Z. The antibodies valuation was carried out by enzyme-linked immunosorbent assays (ELISA-Abbott) and complement fixation test. All the tested markers give a high percentage of positivity even if the values relevant to anti-HTLV III antibodies can not be related to infection but, probably, to anti-HLA-Dr antibodies.

Cytomegalovirus↗
PubMed1986

Reconstitution of T cell functions in aging mice by thymosin alpha 1.

Helper T cell activity of spleen cells from BDF1 mice is impaired by aging but is restored to a large extent by injection of thymosin alpha 1, a synthetic peptide consisting of 28 amino acid residues. Injection of an equimolar amount of the N14 (N-terminal half of thymosin alpha 1) synthetic fragment is at least as effective as the entire alpha 1 molecule in increasing helper T cell activity of spleen cells from old (6-18 months) mice but not from young (3 months) mice. Conversely, injection of the C14 (C-terminal half of thymosin alpha 1) synthetic fragment is devoid of any effect in both young and old mice. Since helper T cell activity of spleen cells from old mice is also increased by injection of interleukin-2, the observed enhancement of interleukin-2 production by mitogen-activated spleen cells from old mice upon injection of thymosin alpha 1 or the N14 fragment suggests that these peptides amplify helper T cell activity by increasing the cell precursor frequency of interleukin-2-producing T cells. This conclusion is further supported by the finding that injection of thymosin alpha 1, or its N14, but not C14, fragment enhances the expression of interleukin-2 receptors on mitogen-activated spleen cells from old but not from young mice.

Aging↗
PubMed1986

In vitro interferon production: induction in human leukocytes after exposure to cytomegalovirus antigens.

In vitro lymphocytes from healthy donors with crude (HCMV), heat inactivated (HCMVi) and infected human fetal fibroblasts (HCMVFF) were stimulated. In all the experiments peak titers of alfa Interferon (IFN) were present 24 h after exposure to antigens. On the other hand, at least after seven days, only lymphocytes of seropositive donors stimulated by HCMVFF and HCMV showed gamma IFN production. Our HCMVFF gave much higher IFN yields than free virus. Our data suggest that HCMVFF and HCMV are recognised by lymphocytes of HCMV specific memory and HCMVFF give additional and more reproducible information on HCMV specific cellular immunity.

Antigens, Viral↗
PubMed1986

The influence of antifungal drugs on adherence of Candida albicans to buccal epithelial cells.

The adherence of two strains of Candida albicans serotype A to human epithelial cells was measured after exposure to different concentrations of amphotericin B, 5-fluorocytosine, nystatin, miconazole and ketoconazole. Germ-tube formation after different exposure times to the antifungal drugs as a preliminary test was carried out. Pretreatment of blastospores with minimum inhibitory concentrations (MIC) and sub-MIC (1/2 and 1/4 of MIC values) for 3 and 72 h did not affect adherence for all drugs tested except amphotericin B. This antimycotic agent reduces significantly the adherence either after 3 or 72 h exposure time. The other antifungal drugs interfere with adherence only after 72 h and at the highest concentrations tested, above MIC values. The decrease in adherence by antifungal drugs suggests that some of these drugs would be useful in the prophylaxis of patients at high risk for candidosis.

Adhesiveness↗
PubMed1986

Comparison between adherence of C. albicans and Candida spp. to human epithelial cells.

A comparison was made of the adherence of different Candida species to human epithelial cells. Three strains each of C. albicans serotype A, serotype B, C. stellatoidea, C. tropicalis, C. krusei and C. glabrata recently clinical isolated were studied. The adherence assay, run in triplicate, was carried out using pooled buccal epithelial cells from healthy donors. The results indicate that both serotypes of C. albicans adhere to buccal epithelial cells in a significantly greater degree than the other species tested and there is no differences between C. albicans serotypes A and B. The rate of adherence of C. stellatoidea and C. tropicalis was similar to that of C. albicans serotypes A and B respectively. Among different strains of C. stellatoidea, C. tropicalis and C. glabrata, the adherence varied significantly and it is possible that there exist a relationship with different degree of pathogenicity of these particular strains.

Candida↗
PubMed1986

Susceptibility of Candida species strains to five antifungal agents: comparison between agar dilution and disk diffusion tests.

The in vitro activity of five antifungal agents were compared against 180 Candida strains. The drugs were: two imidazoles (miconazole and ketoconazole), nystatin, 5-fluorocytosine and amphotericin B. Agar dilution and disk diffusion methods were used. Nystatin, miconazole and amphotericin B were the most active agents. 5-fluorocytosine had high activity except against C. albicans serotype B, of which a high percentage were resistant. Finally, a good correlation between the two methods was observed.

Agar↗
PubMed1985

Bacterial chromosomal restriction endonuclease analysis of the homology of Bacteroides species.

Chromosomal DNAs of selected Bacteroides organisms whose relatedness had been previously determined by "conventional" filter-annealing studies (J. L. Johnson, Int. J. Syst. Bacteriol. 28:245, 1978) were further analyzed by restriction endonuclease analysis coupled with the Southern hybridization procedure (E. M. Southern, J. Mol. Biol. 98:503, 1975). By comparing their EcoRI restriction fragment patterns in agarose gel electrophoresis, each Bacteroides strain could be clearly differentiated. As a simple and direct means for comparison purposes this method was particularly useful for differentiating genetically similar organisms such as Bacteroides strains of the same species which shared greater than 75% homology. In contrast, bacterial chromosomal restriction endonuclease analysis in conjunction with Southern hybridizations was most effectively used to determine the significance of low levels of homology (less than 24%) as this technique provided additional information on the nature and relative distribution of that homology when the areas of homology were displayed as reproducible bands in autoradiograms.

Bacteroides↗