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Biomedical subjects

C De Simone

Publications and source records attributed to C De Simone.

At least 145 records · Page 8Linked to original sources
PubMed1987

Enhancement of immune response of murine Peyer's patches by a diet supplemented with yogurt.

The first line of defense against pathogens that enter the host by the oral route involves the Peyer's Patches (PP). For centuries many populations of the mediterranean basin have empirically administered soured milk (yogurt) to prevent and treat diarrhoea and entero-colitis. Recent reports have offered evidence in favour of a possible influence of yogurt on the host's immunocompetence. Scope of the present study was to evaluate the influence of a diet supplemented with yogurt on the PP from BALB/c mice. The results reported here suggest that yogurt feeding potentiates the host's cell-mediated immune response by increasing the percentage of B lymphocytes and the PHA and LPS-induced proliferative responses of PP cell suspensions.

Animals↗
PubMed1986

Assessment of immunomodulating activity of ofloxacin and three other quinolones in human plasma.

A time-dependent degree of immunosuppression or immunostimulation which may be correlated to pharmacokinetic variables was obtained by administering a single dose of ofloxacin, norfloxacin, pipemidic and piromidic acid to healthy volunteers. The plasma samples collected before drug administration and then at various time intervals were tested for their immunomodifying activity by employing a modified 2-way mixed lymphocyte reaction and a PMN chemotactic assay. Our results show that some of the quinolones tested--norfloxacin, pipemidic acid, piromidic acid--have an immunosuppressive activity.

Anti-Infective Agents↗
PubMed1986

Influence of ofloxacin on murine Peyer's patch lymphocytes.

Several factors must be considered before the clinical impact of antimicrobials on the immune function can be determined. No data are available as yet on the influence of ofloxacin, a new fluoro-quinolone, on the lymphocytes of Peyer's patches. The present study offers evidence that murine Peyer's patches are influenced by ofloxacin administered by the oral route for seven days (15 mg/kg). No modifications of the percentage of the Thy 1,2 and SIg positive splenocytes and of the PHA and LPS-induced proliferative responses were observed studying cell suspensions from the spleen of the same animals. An immunotoxic effect of the compound on the cells of Peyer's patches or an impairment of their homing tendency has been postulated.

Animals↗
PubMed1986

Ofloxacin: clinical evaluation in urinary and respiratory infections.

40 patients with urinary tract (30 cases) or pulmonary infections (ten cases) caused by different agents were treated with ofloxacin in order to evaluate the efficacy and safety of this new quinolone derivative. Treatment was performed with a dose of 300 mg three times a day for nine to 26 days. Out of the 30 urinary tract infections, 22 were clinically and bacteriologically cured, six had a clinical improvement but the causative organism persisted, one suffered a reinfection with a different pathogen and one failed to respond. Clinical and bacteriological cure was achieved in eight of the ten pulmonary infections. The overall clinical response for the two groups of patients was 97% (cure and improvement): bacteriological cure was achieved in 75% of the patients treated. No serious side effects of ofloxacin therapy were observed in any of our patients.

Adult↗
PubMed1986

Eosinophil-mediated cellular cytotoxicity induced by zymosan-activated serum.

The aim of the present work was to develop an in vitro model of eosinophil cytotoxicity which mimics numerous in vivo situations characterized by complement activation through the alternative pathway. Our results demonstrate that eosinophilic granulocytes from patients with parasitic diseases and blood eosinophilia were able to damage chicken red blood cells when incubated with zymosan-activated serum (ZAS) as assessed by a 51Cr release assay. The phenomenon was independent of the presence of antibodies directed against the target cells and related to the quantity of ZAS added to the wells. As target cell lysis is totally or partially inhibited by catalase, sodium azide and potassium cyanide, an involvement of toxic oxygen derivatives as cytolytic mediators was suggested.

Azides↗
PubMed1986

Human eosinophils and parasitic diseases--III. Beta-interferon increases eosinophil IgG-Fc receptor expression and capacity.

Eosinophilic granulocytes from the blood of patients with parasitic diseases were preincubated in the presence or absence of beta-interferon (beta-IFN). The number of cells bearing IgG-Fc receptors was determined by rosette formation with chicken erythrocytes coated with IgG antibodies. beta-IFN augmented the expression of IgG-Fc receptors on the cells within 1 h incubation. Treatment of beta-IFN with heat or acid did not abolish the activity. The doses of beta-IFN needed to induce the modulations of IgG-Fc receptors could also augment the eosinophil-mediated antibody-dependent cytotoxicity (ADCC) against chicken red blood cells which resulted most pronounced when the IgG antibodies were present in suboptimal amount. These data suggest the role of beta-IFN in the host resistance to parasitic diseases, mainly in the initial phases of parasitic infestation when the specific IgG antibody levels are very low.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1986

Influence of ofloxacin, norfloxacin, nalidixic acid, pyromidic acid and pipemidic acid on human gamma-interferon production and blastogenesis.

Several new quinolone derivatives were investigated for their influence on human lymphocyte blastogenesis and gamma-interferon production following concanavalin A stimulation. All the antimicrobials induced inhibition of lymphocyte DNA synthesis. The gamma-interferon measurements showed that nalidixic acid and norfloxacin have a negative influence on lymphokine production and release.

Adult↗
PubMed1985

Human amoebiasis: the interaction of lymphocyte surface-bound immune complexes and PMNs impairs T cell proliferative responses to E. histolytica mitogen.

In some of the sera from patients with amoebiasis circulating immune complexes are present which are thought to interact with lymphoid cells, enabling them to elicit a burst of oxygen consumption in PMNs. The intensity of chemiluminescence is related to the presence of C3+ and Fc IgG+ cells in the lymphoid cell suspensions employed. The generation and release of highly reactive oxygen derivatives from PMNs impair T lymphocyte proliferative responses to the E. histolytica mitogen. The Authors suggest that one of the mechanisms by which circulating immune complexes present in the sera of patients with amoebiasis may interfere with T cell-mediated immune responses, is through their binding to the surface of the C3+, Fc IgG+ cells with subsequent stimulation of the PMN oxidative metabolism.

Adult↗
PubMed1984

Anti-Ia reactivity in sera from subjects with Entamoeba histolytica infection.

Sera from 15 patients with Entamoeba histolytica infection were tested for anti T-cell antibodies by assessing cross-reacting specificities with the antigens defined by an anti-Ia hybridoma antibody. T cells prepared by sheep erythrocyte rosetting were preincubated with the test sera and then with the anti-Ia antibody. Binding of the specific monoclonal antibody was assessed by rosetting with ox erythrocytes conjugated with goat anti-mouse IgG. Eight sera from amoebic patients were found to block the binding of monoclonal mouse hybridoma anti Ia-antibody to T cells. Blocking of anti-Ia binding was not due to Fc IgG receptor binding by immune complexes nor was it HLA-DR restricted. T cells pre-treatment with the amoebic sera positive for anti-Ia activity showed reduced activity when tested in the autologous mixed lymphocyte reaction (AMLR). The results of our study seem to suggest the existence of specific anomalies of immunoregulation during E. histolytica infection which may play a role in inducing immune disregulation in vivo.

Adult↗
PubMed1984

The effect of NPT 15392, 9-(erythro-2-hydroxy-3-nonyl)-6-hydroxypurine, on the phytohemagglutinin of OKT3+, OKT4+, OKT8+, and OKM1+ cell-depleted and undepleted peripheral blood mononuclear cells.

NPT 15392, 9-(erythro-2-hydroxy-3-nonyl)-6-hydroxypurine, has been reported to influence immunological responses involving different cell types. Herein data are obtained by studying the influence of NPT 15392 on the phytohemagglutinin (PHA)-induced proliferative responses of unfractionated peripheral blood lymphocytes (PBLs) and of cell suspensions, which have been depleted of the cell subsets recognized by the monoclonal antibodies OKT3, OKT4, OKT8, and OKM1, in an attempt to identify which cell types respond to NPT 15392 in the PHA-driven blast transformation assay. The proliferative responses of unfractionated peripheral blood lymphocytes are potentiated when the drug is employed at the concentration of 0.1 microgram/ml and inhibited when NPT 15392 is added to the cell suspensions at concentrations over 5 micrograms/ml. The data reported here suggest that this phenomenon is a composite effect, made up of a combination of the counteracting effects caused by the OKT4+ cells on the one hand, and the OKT8+ and OKM1+ cells on the other.

Antibodies, Monoclonal↗
PubMed1984

Pharmacokinetic assessment of immunosuppressive activity of antibiotics in human plasma by a modification of the mixed lymphocyte reaction.

Antibiotics may impair the development and expression of specific or nonspecific immune responses. Prophylactic administration of antibacterial antibiotics is widely used in ICUs. We studied the immunosuppressive activities of cefotaxime, chloramphenicol, gentamicin, metronidazole, and rifamycin as a function of time after the administration of these drugs to ICU patients, finding that the last 4 drugs had an immunosuppressive activity detectable up to 8 h by a mixed lymphocyte reaction. When these antimicrobial agents were added to normal pooled plasma in concentrations similar to those obtained in vivo, a similar degree of inhibition was observed.

Adult↗
PubMed1984

Systemic and ocular effects of alpha 2-adrenergic stimulating and beta 2-blocking agents.

The effects of alpha 2-adrenergic stimulating agents (clonidine and guanabenz) and beta-adrenolytic agents (atenolol and propranolol) on the systemic arterial pressure, heart-rate, blood glucose level and intraocular pressure, as well as on the concentrations of glucose, Na+, K+ and Ca++ in the lens and aqueous and vitreous humours, are evaluated in the rabbit. alpha 2-adrenergic stimulating agents cause a significant increase of the glucose concentration in the blood, lens, aqueous and vitreous humours; whereas the beta-adrenolytic agents cause insignificant effects. Neither of the two drugs alters the concentration of Na+, K+ and Ca++ in the lens and aqueous and vitreous humours.

Adrenergic alpha-Agonists↗
PubMed1984

Methisoprinol and corticosteroids: immunopharmacokinetic assessment.

Methisoprinol is an antiviral drug with immunopotentiating properties. The aim of this study was to assess the immunopharmacokinetic profile of the drug alone or administered in conjunction with corticosteroids. The plasma of patients who had been given a single dose of methisoprinol, prednisolone or both was collected before the infusion and at different time intervals thereafter. The plasma samples were tested for immunosuppressive or immunopotentiating activity in a mixed lymphocyte culture (MLC). The test was modified to increase sensitivity and decrease variability. The administration of methisoprinol resulted in increased responses up to three hours after the infusion. The simultaneous administration of both drugs resulted in an even more marked inhibition of MLCs as compared with corticosteroids alone.

Adjuvants, Immunologic↗
PubMed1983

LDH isoenzyme distribution in human eosinophils.

The lactate dehydrogenase (LDH) isoenzyme pattern has been determined in human eosinophils isolated from the peripheral blood of healthy donors and patients with parasitic diseases. Almost equal LDH1 and LDH5 values appear to be a characteristic of the eosinophils obtained from healthy subjects. Eosinophilic granulocytes which have been isolated from the peripheral blood of patients with eosinophilia due to parasitic infestations have reduced values of LDH5 accompanied by higher LDH1 as compared with eosinophils from healthy donors. Centrifugation of cells through multiple discontinuous gradients of polyvinylpyrrolidone-coated silica particles made it possible to isolate distinct eosinophil subpopulations of differing densities which showed differences in cell surface markers, K-cell activity and also LDH patterns. Analysis of the lactate dehydrogenase isoenzyme patterns showed that EAG+ and EAC+ eosinophilic leukocytes are characterized by very low values of LDH5.

Animals↗
PubMed1983

Density and size distributions of the intramembranous particles in the cytoplasmic membrane of human peripheral blood lymphocytes. II. Ultrastructural differences between T and B cells.

Separated T and B lymphocytes from human peripheral blood were studied using the freeze-fracture technique. Quantitative analysis performed on density and size of intramembranous particles (IMPs) present on both fracture faces of the plasma membrane has revealed remarkable differences between cells belonging to the two main lymphocyte populations. In particular: (a) both fracture faces of the cytoplasmic membrane of B lymphocytes exhibit larger particles than T lymphocytes; (b) the mean densities, on both protoplasmic (PF) and external (EF) fracture faces, in B lymphocytes are lower than in T lymphocytes; (c) in B cells the partition ratio of particles between PF and EF is reversed with respect to T cells; (d) on both fracture faces of B lymphocytes, the IMP densities present a normal distribution while on T cells, density values show bimodal distributions indicating the existence of two cell subsets differing in particle density.

B-Lymphocytes↗
PubMed1982

Human peripheral eosinophils with receptors for IgM: demonstration and ultrastructural morphology.

Receptors for IgM were detected on peripheral blood human eosinophils by a rosette technique with ox red blood cells coated with the IgM fraction of the specific immunserum. Between 14% and 43% (mean 27%) FcmuR positive cells were found after an overnight incubation period at 37 degrees C by using this technique. The specificity of the receptors for IgM was assessed by studying the inhibitory capacity of purified human IgM in the rosette assay. From an ultrastructural point of view, the EAM rosette-forming cells are mature eosinophilic granulocytes characterized by a nucleus with a variable number of lobes and a certain number of "first type" granules partially or totally devoid of their content.

Binding, Competitive↗
PubMed1982

In vitro effect of inosiplex on T lymphocytes. I. Influence on T cells with receptors for IgG (T gamma).

Inosiplex, a complex of inosine and 2-hydroxypropyldimethyl ammonium-4-(acetylamino)benzoate, 1:3 molar ratio, originally developed for antiviral use, is now under wider investigation because of its immunopotentiating properties. This compound can have some actions on T cells at various stages of differentiation, thus promoting an enhancement of their blastogenic responses to varied mitogenic agents (PHA, Con A, PWM, MLC, tetanus toxoid, and viral antigens). Our studies demonstrated that under the influence of inosiplex human peripheral blood T lymphocytes bearing Fc IgG receptors have an augmented receptor avidity for SRBC which result in an increased E active rosette formation, and that T cells preincubated with the drug at the appropriate concentrations express more Fc IgG receptors. Even though T gamma cells exert "in vitro" immunoregulatory properties, the increase in percentage of T gamma lymphocytes do not correlate with a potentiation of the Con A-induced suppressor activity of T cells. Moreover, the lymphocytes treated with the substance in the absence of Con A exert helper functions, increasing the mitogenic responses of the second culture PHA--treated lymphocytes. These data appear to suggest a pro-proliferative inosiplex-induced effect which could mask a concomitant suppressor cell induction.

Adjuvants, Immunologic↗