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Biomedical subjects

C Mancini

Publications and source records attributed to C Mancini.

At least 109 records · Page 6Linked to original sources

Effect of cyclosporin A on natural killer cells' response during viral infections.

In the this study the modification of lymphocyte subsets (T3, T4, T8) and Natural Killer (NK) cells in organ transplanted patients treated with Cyclosporin A (CyA) in the course of viral infection, have been analyzed. Different subsets have been studied with the monoclonal antibody method and infective processes have been verified by serological data of seroconversion. Our study has shown that CyA at the adopted doses does not alter NK response to viral infection; in fact, in patients with seroconversion, higher NK values and lower OKT4/OKT8 ratio values have been found with respect to patients who did not show any viral infection serologic data. Furthermore an increased incidence of reject crisis has been observed in patients with seroconversion.

Antibodies, Monoclonal↗

[Sero-epidemiological results in subjects receiving a renal transplant].

In this study a sero-epidemiological investigation on 127 renal allograft recipients was examined. In these patients, treated with Cyclosporine A or conventional drugs, antibody response to various antigens (Cytomegalovirus, Herpes simplex, Varicellae/Zoster and Mycoplasma pneumoniae) was examined. The data were compared to the healthy population and dialyzed subjects.

Adolescent↗

Spontaneous lymphomas in mice genetically selected for high or low phytohemagglutinin responsiveness.

Biozzi mice selected for high (Hi) or low (Lo) responsiveness to phytohemagglutinin (PHA) have been followed for their entire life-span to examine their pathology at death. Spontaneous lymphomas were found to exhibit higher incidence and faster development in Lo/PHA than in Hi/PHA females, whereas a similar difference between the two lines did not attain the level of statistical significance in male mice. The incidence of solid tumors was higher in Lo/PHA than in Hi/PHA males but the same in females of the two lines, yet the probability of dying from solid tumors was slightly increased in Lo/PHA mice of both sexes. All these results indicate that T-cell-mediated immunity influences mainly the spontaneous incidence of lymphomas and, to a lesser degree, the appearance of other solid tumors.

Animals↗

[In vitro activity of norfloxacin against gram-positive and gram-negative organisms from recent clinical isolates].

A total of 274 recently isolated Gram-positive e Gram-negative strains have been tested. The method used for the determination of the minimal inhibitory concentration of the antibiotics was by agar dilution and the minimal bactericidal concentrations were determined by "replica plating" system. All strains demonstrated a good sensitivity, above all, to Norfloxacin which inhibited Gram-positive bacteria at the concentration of 3.12 micrograms/ml and, concerning Gram-negative, at the concentration of 0.10 microgram/ml for K.E.S. group, 0.19 microgram/ml for Escherichia coli, 6.25 micrograms/ml for Proteus sp and 1.56 microgram/ml for Pseudomonas aeruginosa. Also with the other antibiotics we obtained good results especially with Nitrofurantoin concerning Enterococcus and Ceftazidime concerning all the strains. On the basis of these results we can conclude that Norfloxacin is one of the most active antibiotics among those used against strains implicated in urinary infections.

Escherichia coli↗

[Incidence of Pseudomonas sp., Staphylococcus sp. and Candida sp. in a high-risk population].

Since infections represent one of the greatest complications in immunocompromised hosts, our group, concerned with bacteriological monitoring, has applied its attention to microorganisms such as Pseudomonas sp, Staphylococcus sp and Candida sp. Pseudomonas sp strains have been identified using conventional techniques and the API system 20 NE. According to Varaldo's scheme, Staphylococci sp have been divided into six "lyogroup" and then, the typing of Candida sp has been checked by cultural and biochemical tests. The results obtained have demonstrated that the Pseudomonas aeruginosa species is prevalent not only in the urinary tract but also in the respiratory tract. As for the Staphylococci sp, the VI lyogroup showed the greatest percentage of strains and than, as regards Candida sp it has been possible to observe that, over a given period, the percentage of pluricontamination has been almost constant.

Candida↗

[Pulmonary infectious complications caused by cytomegalovirus in clinical kidney transplantation].

Infections constitute one of the main complications in organ allografts because of the immunosuppression status of the patient due to the own disease and the reduction of the immunoresponse dealing with the immunosuppressive therapy. Moreover the bacterial, micotic and parasitic infections show a lower incidence while viral infections affect more frequently the patients. On these basis the AA, report their experience on 162 kidney allografts with particular reference to cytomegalovirus pulmonary infections observed in nine patients. Five patients died of acute respiratory insufficiency while in three cases a complete resolution of the clinical picture has been observed. Finally one case underwent the association of pulmonary infection and irreversible graft failure due to rejection. The AA. conclude that the cytomegalovirus pulmonary infection is particularly riskfull in the non immunocompetent patients and stress the potent effect of the high titer specific immunoglobulins to prevent such often lethal complication.

Adult↗

In vitro susceptibility tests with cefoperazone compared with cefotaxime, cefoxitin, cefuroxime, cephaloridine and gentamicin.

Minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs) and sensitivity disc tests of cefoperazone, cefotaxime, cefoxitin, cefuroxime, cephaloridine and gentamicin were determined from 300 Gram-positive and -negative isolates from kidney transplant recipients. Cefoperazone inhibited 50% of Pseudomonas aeruginosa strains at a concentration of 6.25 micrograms/ml. Only gentamicin had similar activity but if we consider the sources of our strains and the nephrotoxicity of the compound, its use is not suitable. Moreover, cefoperazone was able to inhibit from 50% to 90% of the other strains at variable concentrations between 0.39 micrograms/ml and 3.12 micrograms/ml.

Bacteria↗

Life-span, tumor incidence, and natural killer cell activity in mice selected for high or low antibody responsiveness.

Biozzi mice selected for high (H) or low (L) antibody responsiveness to natural antigens have been followed for their entire life-span to examine their pathology at death. As previously found in selection I, shorter life-span and higher lymphoma incidence were observed in L responder mice than in H responder mice selected for antibody responsiveness to sheep red blood cells (selection II). In mice selected for antibody responsiveness to Salmonella flagellar antigens (selection III), similar life-span and similar lymphoma incidence were found in H and L responder mice. Natural killer (NK) cell activity, as assessed in spleen cells from young mice, was lower in L than in H responder mice of selection I but higher in L than in H responder mice of both selections II and III. All these results indicate that longevity and lymphoma incidence at death are independent of NK cell activity in mice selected for H or L antibody responsiveness to natural antigens. Furthermore, genetic selection for antibody responsiveness does not always appear to influence life-span and lymphoma incidence.

Animals↗

Immunoregulation in senescence: increased inducibility of antigen-specific suppressor T cells and loss of cell sensitivity to immunosuppression in aging mice.

Azobenzenearsonate (ABA)-specific T cell-mediated suppression has been studied in aging mice. ABA-specific suppressor T cells were induced in young and old mice by injection of ABA conjugated to syngeneic spleen cells (ABA-SC). These suppressor cells were tested for their ability to suppress the in vitro anti-trinitrophenyl (TNP) antibody response of lymph node cells obtained from ABA-keyhole limpet hemocyanin (KLH)-primed young or old mice and cultured with TNP-ABA-KLH. Suppressor T cells were found to be more easily induced in old than in young mice but to suppress less efficiently the antibody response of cells from old than from young mice. The increased inducibility of antigen-specific suppressor T cells in old mice is compatible with the age-dependent decline of immune responsiveness to exogenous antigens. The loss of cell sensitivity to antigen-specific immunosuppression as well as the lack of evidence for increased nonspecific suppression in old mice is consistent with the age-related increase in autoimmune disorders. These findings provide a unifying explanation for the most relevant immunological phenomena of senescence.

Aging↗

T-cell-dependent oscillations of IgM antibody affinity during the immune response to DNP-Dextran to low or high epitope density.

Anti-hapten IgM antibody response and affinity were evaluated by haemolytic plaque inhibition assay on spleen cells from mice immunized with 2,4, dinitrophenyl (DNP)1.3-Dextran or DNP13-Dextran. Regardless of epitope density, affinity was found to mature with time after immunization and to be characterized by rapid oscillations independent of changes in anti-hapten plaque-forming cell (PFC) response and antibody secretion rate. Injection of the lower epitope density immunogen not only elicited higher PFC responses and higher affinity antibodies but also induced more pronounced affinity oscillations mainly confined to the higher affinity PFC subpopulation. Immunization of athymic nude mice with DNP1.3-Dextran elicited PFC responses comparable to those observed in similarly immunized euthymic mice. However, affinity oscillations were drastically reduced in athymic mice and the restricted variation of antibody affinity observed shortly after immunization was followed by no oscillations in any of the affinity PFC subpopulations. Athymic mice did not produce high affinity PFC which account to a large extent for the affinity oscillations observed in euthymic mice. These findings demonstrate the important role of T cells in the appearance of rapid changes in IgM antibody affinity. The generation of T-cell-dependent oscillations of high affinity antibody-producing cell subpopulations is discussed in terms of interactions among cells and soluble factors involved in regulatory circuits of the immune network.

Animals↗

Synergism between two helper cell subpopulations characterized by different radiosensitivity and nylon adherence.

The present work extends our previous results on the radiosensitivity of the helper cell function. Two helper cell subpopulations, 1 radiosensitive and the other radioresistant, have been demonstrated in the spleen of mice at different times after priming with HRBC. The radiosensitive subpopulation increases with the increasing time interval between carrier-priming and irradiation. The 2 cell subpopulations have been further characterized by different nylon adherence properties: radioresistant helper cells adhere to nylon wool, whereas radiosensitive cells pass through. The 2 cell subpopulations were separated by x-irradiation and nylon wool filtration, and their helper activity was assessed separately or after recombination. The results favor the notion that 2 functionally independent helper T cells, as characterized by different radiosensitivity and nylon adherence, participate synergistically in the helper activity of primed spleen cells.

Animals↗

Oscillations of IgM antibody affinity at the level of single immunocytes.

IgM antibody affinity was measured by hemolytic plaque inhibition assays on spleen cells from mice immunized with a single injection of DNP-dextran. Maturation of affinity was found to occur with time after 1 to 1000 microgram of immunogen and to be characterized by rapid oscillations independent from changes inFC number/spleen and in antibody secretion rate. Analysis of affinity heterogeneity showed that such oscillations occur in higher affinity PFC subpopulations. The origin of affinity oscillations was discussed in terms of interactions among antigen and the elements of the immune network.

Animals↗