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Biomedical subjects

A Vecchiarelli

Publications and source records attributed to A Vecchiarelli.

At least 91 records · Page 5Linked to original sources
PubMed1985

Immunoadjuvant activity of amphotericin B as displayed in mice infected with Candida albicans.

Mice receiving a single intraperitoneal injection of amphotericin B showed increased resistance to subsequent challenge with either Candida albicans or Staphylococcus aureus. This enhancement of resistance was obvious in terms of both survival criteria and clearance of the intravenously injected organism from different organs. The protective effect of amphotericin B was conditioned by dose, time of drug administration, and size of yeast or bacterial inoculum and was reversed by cyclophosphamide. Effector cells from mice treated with amphotericin B displayed enhanced fungicidal activity in vitro as measured in a short-term 51Cr release assay. Macrophages from intact animals exposed in vitro to amphotericin B also acquired strong candidacidal reactivity.

Adjuvants, Immunologic↗
PubMed1984

A comparison of experimental pathogenicity of Candida species in cyclophosphamide-immunodepressed mice.

The experimental pathogenicity of Candida albicans, C. krusei, C. guilliermondii, C. parapsilosis, C. tropicalis and C. viswanathii was tested in normal and in cyclophosphamide-(Cy) immunodepressed mice. In unpretreated CD1 mice only C. albicans, C. tropicalis and C. viswanathii were pathogenic on intravenous challenge, with LD50 of 1.0 X 10(6), 4.8 X 10(6), 7.2 X 10(8) cells, respectively, per kg. Three days after a single intraperitoneal injection of Cy (150 mg kg-1) mice had a marked decrease in spleen weight and cellularity as well as reduced numbers of circulating leukocytes. Under these conditions, there was a significant, proportional increase in pathogenicity of C. albicans, C. tropicalis and C. viswanathii but the animals were still resistant to challenge with C. krusei, C. guilliermondii and C. parapsilosis. This pattern of susceptibility was not influenced by higher doses of Cy. Only C. albicans and C. tropicalis were capable of rapid and extensive multiplication in target organs such as kidney and brain in normal and Cy-treated mice and for both these species of Candida, there was a 'rebound' effect of increased resistance to experimental infection after 12 days from Cy administration. This study shows that the strong immunodepression provoked by Cy does not modify significantly the susceptibility of the animal to those species of Candida which were endowed with low or no pathogenicity for normal mice, but it greatly increases the susceptibility to those species of Candida that are already pathogenic for unmodified host.

Animals↗
PubMed1983

Comparison of passive hemagglutination with Turkey erythrocyte assay, enzyme-linked immunosorbent assay, and counterimmunoelectrophoresis assay for serological evaluation of tetanus immunity.

Antibody titers to tetanus toxin in human sera were assayed by passive hemagglutination with turkey erythrocytes, enzyme-linked immunosorbent assay, and counterimmunoelectrophoresis. The first two of these tests were shown to be the most sensitive for antibody detection, having the same range of sensitivity and reproducibility. The antibody levels determined by these assays were up to 400-fold higher than those determined by counterimmunoelectrophoresis. The turkey erythrocyte hemagglutination assay requires only 40 min, whereas the immunosorbent assay method requires 24 h. These results suggest that the hemagglutination assay is the more appropriate method for rapid and sensitive determination of tetanus antibody levels.

Journal Article↗
PubMed1980

[The use of BCG as immunoadjuvant in combination with antitumor drugs in a virus induced leukemia. II].

Various treatment schedules of BCG with respect to tumor challenge and drug administration were applied in a histocompatible tumor-host system. LSTRA, an ascitic lymphoma induced by Moloney leukemia virus in BALB/c mice, was inoculated ip in histocompatible CD2F1 mice. BCG was administered ip before and/or after (-14, +1, -14+1) the tumor challenge. The drugs used in our experiments: cyclophosphamide (CY), iphosphamide (IPHO), nitrogen mustard (NM), were given at graded doses on day +5. In our experimental system the BCG treatment schedule (-14+1) only showed synergistic antitumor effects at defined doses: only the association BCG-CY have no significant survival percentage increase. No synergistic antitumor activity was evidenced when the drugs were associated with BCG given 14 days before or 1 day after the tumor challenge. The degree of immunochemotherapy treatment efficacy was different according to various antineoplastic agents used. It was never found any treatment schedule was able to cure experimental mice with the best survival percentage increase.

Adjuvants, Immunologic↗
PubMed1980

[Use of BCG as an immunoadjuvant in combination with antitumor agents in virus-induced leukemia].

The effect of administration of BCG in association with chemotherapy in histocompatible CD2F1 mice challenged ip with Moloney-virus-induced lymphoma LSTRA of Balb/c origin was studied. All untreated mice died with comparable median survival time (MST). Immunochemotherapy experiments were performed in histocompatible mice using BCG according to various treatment schedules with respect to tumor challenge and 3 nitrosureas of clinical interest (i.e. BCNU, MeCCNU and CCNU) administration. If recipients were subjected to ip treatment with drugs alone or in association with the non specific immunoadjuvant (IA) given after tumor challenge (on day +1); no significant antitumor effect was detected. Synergistic antitumor effects were evidenced when the antineoplastic agents were associated with IA administered on the "-14+1" regimen with respect to the tumor. The results pointed out that the antilymphoma effects of chemotherapy could be amplified by IA only when the treatment schedule included adjuvants administration prior to tumor challenge.

Animals↗
PubMed1977

Enhanced early response to tetanus toxoid, in rabbits.

AIPO4 adsorbed tetanus toxoid injected in rabbits according different vaccination schedules, gives rise to antibody responses with varying lag periods. Shortening the intervals among antigen injections, or increasing the quantity of toxoid per dose, makes it possible to reach protective serum antibody levels in 10 days. That is to say, in a period of time shorter than the mean tetanus incubation in man. Although difficult to transfer to man, the exposed data suggest a possible differentiated antitetanus vaccination in subjects at risk, non protected.

Animals↗
PubMed1977

Anti-Candida albicans precipitating antibodies in the sera of surgery patients.

In healthy subjects and in subjects undergoing surgical intervention for neoplastic and other diseases, the behaviour of precipitating antibodies against soluble Candida albicans natigens was studied. In 13,7% of healthy controls the Ouchterlony test was positive. In subjects suffering from intestinal tract neoplasia, the percentage of positive tests was 26,6% before and 66,6% after the intervention. In other two groups of patients affected by neoplasia, the per cent positive results of the tests after intervention were, respectively, 50% and 63,1%. Among non neoplastic patients undergoing surgical treatment, after intervention 35% too proved positive. The data were confirmed by P.E.T. (partigen elution test): specific anti-Candida IgG, and in some cases IgA, could be demonstrated. The diagnostic value of positive Ouchterlony's test against superficial soluble Candida antigens after surgical intervention has been discussed.

Antigens, Fungal↗
PubMedDate not supplied

[The anti-tetanus serumprophylaxis (author's transl)].

The antitoxin titre against tetanus toxin has been evaluated in wounded subjects before and 24 after anti-tetanus serumprophylaxis by passive haemagglutination. Treatment with digested heterologous antiserum (3000-6000 I.U.) or with human hyperimmune immunoglobulins does not modify preexisting antitoxin titre. Serum negative subjects remain as such.

Antibody Formation↗
PubMedDate not supplied

[Chemical composition and protein value of some baby foods (author's transl)].

The determination of lipids, available carbohydrates and unavailable carbohydrates, and of various minerals has been carried out on some baby foods; the value of the protein fraction has been similarly determined by the ultrafiltration method of the enzymic hydrolisate in vitro. Both the total protein content and the essential amino acid availability of the foodstuffs are satisfactory although generally speaking a slight decrease of the protein value has been found in this material as compared to the crude samples, due particularly to the breakdown of sulfur-containing amino acids. This breakdown is due probably to the high temperature reached during the technological processes at industrial level.

Amino Acids↗
PubMedDate not supplied

Interferon-gamma (r-IFN-gamma) induced activation of alveolar macrophages (AM) from anergic patients with chronic obstructive pulmonary disease (COPD).

Forty-six anergic patients (37 males and 9 females, age range 55-79 yr) were selected from ninety-one patients suffering from COPD due to frequent exacerbations and impaired delayed cutaneous reactivity (43.9%). The phenotype of circulating lymphocytes, their proliferative response to a panel of polyclonal T-cell activators and the candidacidal activity (CA) of circulating PMNs (polymorphonuclear cells) were measured. In 13 patients presenting a defective CA of circulating PMNs, the in vitro response of alveolar macrophage CA to r-IFN-gamma was also determined. We found: 1) a significant reduction in the CL response to PHA in COPD patients vs controls; 2) a low PMN-CA in 23 (57%) COPD patients; 3) a non-significant difference in phenotype analysis in patients and controls; 4) lower CA of AMs in COPD patients than in controls; 5) restoration in vitro of CA by r-IFN-gamma in the group of anergic COPD patients presenting depressed CA. We conclude that a defective cell-mediated immunity could be the basis of the enhanced susceptibility to infectious exacerbations in many COPD patients and that, in vitro, it could be reversed by r-IFN-gamma treatment.

Aged↗
PubMedDate not supplied

[Some experimental data on the seroprophylaxis of tetanus].

The survival time of tetanus heterologous antitoxins, crude or digested, has been controlled by indirect haemagglutination (I.H.A.) and neutralization tests in guinea pigs and rabbits. Digested antitoxins are demonstrable in guinea pigs up to the 8th day, in rabbits only during the first day. They reach the highest level 24 hours after the injection: tested with I.H.A. show a good correlation with the quantity of injected antitoxin. In the sera of three wounded subjects, treated with Ig or digested horse antitetanic serum, after 24 hours the I.H.A. test was negative, while the neutralizing antibody titer was equal to 0.1/0.01 I.U./ml. These contrasting results are probably due to circulating Fab' gragments from decaying tetanus antitoxins.

Animals↗
PubMedDate not supplied

[Tetanus prevention with vaccine and with vaccine plus heterologous immune serum: serum antibody levels in the rabbit].

Haemagglutinating antibodies have been assessed in rabbits undergoing active- passive immunization against tetanus. The animals received 6 injections of horse immune serum, 400 UI/kg, and A1PO4 adsorbed toxoid, 0.35 Lf/kg, every 30th day. One the 5th day, after the first injection, E.A. antibodies appeared, at low levels, as a result of a passive immunization. Thereafter the tests became negative, up to the 70th day, when an active immunization emerged, with a 25 days delay in comparison with controls. Neutralization test in vivo behaved in the same way. The results stress once more the need to give up the use of heterologous immune sera in tetanus prophylaxis, in active-passive immunization as well. Arguments adding force to this point of view are: the sensibilization against heterologous proteins, the very low (if any) passive protective action, and, last not least, the delay in the emergence of active immunization: the only reliable shield against tetanus.

Animals↗
PubMedDate not supplied

Resistance induced by concanavalin A and phytohaemagglutinin P against tetanus toxin in mice.

The effect of concanavalin A (ConA), phytohaemagglutinin P (PHA) and Limulus polyphemus haemocyanin (LPH) on the lethal activity of tetanus toxin (TT) is reported. C3H mice treated s.c. with ConA or PHA but not with LPH from 48 h before to 12 h after s.c. TT challenge showed a significant increase in median survival time compared to control mice inoculated with toxin alone. This protective effect was also obtained when PHA or ConA was administered by the i.p. route, TT being injected s.c. In further studies, mice treated with ConA or PHA by different routes (s.c., i.p. or i.v.) were challenged s.c. with graded minimal lethal doses of TT, with or without i.p. administration of horse antitetanus serum (HATS) 24 h after toxin inoculation. The mice treated with ConA or PHA + HATS showed a significantly increased survival rate and a higher percentage of cured mice with respect to control animals treated with lectins alone. In contrast, the mice challenged with TT and treated with HATS alone did not show any increased survival with respect to untreated controls. Sera from ConA- or PHA-treated mice were unable to neutralize the TT. Immune depression in mice by total-body irradiation (400 R) did not abolish the protective activity of the lectins. These results show that in vivo treatment of mice with ConA or PHA but not with LPH can protect against the lethal effects of TT.

Animals↗