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Biomedical subjects

G Cavallo

Publications and source records attributed to G Cavallo.

At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

Lymphokines and cancer.

In the last fifteen years the role of cytokines in the modulation of anti-tumor responses has been extensively studied at the Institute of Microbiology of the University of Turin. In retrospect many observations appear to have been quite innovative and original. Altogether they form the steps of a consequential intellectual endeavour leading progressively towards a precise definition of the role of the lymphokines in modulating the immune response to neoplasia. Starting from the characterization of the tumor signals required for lymphokine induction, this research progressed towards the definition of the cellular, molecular and genetic mechanisms involved, and provisionally ends with the direct manipulation of lymphokine genes transfected to tumor cells.

Animals↗
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[Host-parasite interactions: mechanisms for recognition and attack].

Host-parasite interactions were studied by several researchers in these last years, both to better understand some parasite diseases and to identify new targets and strategies for the control of these infections. In this paper some of the most important recognition's mechanisms demonstrated between specific parasite structures and host cell receptors are reported, and particularly those concerning protozoa Leishmania, Plasmodium, Entamoeba, Giardia and Pneumocystis.

Adaptation, Physiological↗
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[Changes in the blood zinc in the irritable bowel syndrome: a preliminary study].

Having outlined the important role played by zinc in the human metabolism and the alteration which may occur as a result of a zinc deficit, the paper reports a study of 50 patients affected by irritable bowel syndrome. Two subgroups have been identified (Ac and Ad), characterised by reduced blood zinc [correction of zinchemia] and increased fecal excretion of zinc. This finding suggests that the syndrome has a multifactorial pathogenesis and that over time it may follow a different pattern in the different subgroups.

Adolescent↗
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[Biological activity of gamma interferon on various cell types in human and murine systems].

The effects of interferon (IFN gamma) and of IFN alpha/beta on normal T and B lymphocytes and various T and non-T human and murine cell lines have been investigated. IFN gamma, unlike IFN alpha/beta, did not promote the antiviral state in T cells. The lack of antiviral activity was confirmed at the biochemical level by the finding that 2',5' oligoadenylate synthetase activity is not induced in T cells by IFN gamma only.

2',5'-Oligoadenylate Synthetase↗
PubMedDate not supplied

Interferon gamma does not induce antiviral resistance in T lymphocytes.

We compared the activity of human recombinant alpha and gamma interferons (IFNs) on normal T lymphocytes and various T cell lines. IFN gamma, unlike IFN alpha, did not promote the antiviral state in these cells, or induce the activity of 2'-5' oligoadenylate synthetase. The lack of antiviral effect was observed using an RNA virus (VSV) and a DNA virus (HSV, type 1) as challenger viruses.

2',5'-Oligoadenylate Synthetase↗
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[Analysis of the gamma interferon receptor in mice].

Natural murine interferon-gamma (IFN-gamma) produced by the T lymphoma, L12R4, stimulated with phorbol myristic acetate was purified by anti-murine IFN-gamma immunoadsorbent and labeled with 125I to study its binding to receptors of mouse cells. By adding increasing concentrations of unlabeled natural murine IFN-gamma in competition binding assays we determined a KD of 8.2 X 10(-10) M for L1210 cells and a number of receptors of about 3000. Moreover protease, but not endoglycosidase treatment of target cells prevented the subsequent binding of the ligand. These studies demonstrate that natural murine IFN-gamma binds in a specific manner and with high affinity to receptors on murine cell lines.

Animals↗
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[Characterization of the receptor for murine gamma interferon].

Rabbits immunized with murine cells EL-4 expressing high number of interferon-gamma (IFN-gamma) receptors produce antibodies which inhibit the specific binding of murine 125I-IFN-gamma to the surface of target cells. Moreover to define the M.W. of the IFN-gamma receptor we have performed cross-linking experiments using 125I-IFN-gamma. The results obtained reveal that the IFN-gamma receptors has a M.W. of about 90-95.000 d.

Molecular Weight↗
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Production of polyclonal antibodies against the cellular IFN-gamma receptor.

In this work we consider the possibility to produce a polyclonal antibody against murine interferon gamma receptors by immunizing rabbits with the complex receptor-IFN-gamma immunoprecipitated by a monoclonal antibody (AN-18) recognising the ligand bound to the receptor. Using the Western Blotting technique it has been found a polyclonal serum directed against a protein (90 kDa) that could represent the murine IFN-gamma membrane receptor.

Animals↗
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[Modulation of the action of interferon-gamma by protein G].

These studies were designed to investigate the characteristics of the intracellular second messengers induced by interferons (IFN-alpha/beta and IFN-gamma) after receptor binding. Pretreatment of target cells with V. cholerae toxin, which is Known to activate the GTP-binding stimulatory protein (Gs), potentiated the action of IFN-gamma, but not of IFN-alpha/beta. By contrast, B. pertussis toxin, which is known to act on the GTP-binding inhibitory protein (Gi doesn't affect the action of both IFN) (Gi). Besides this forskolin and PGE1, known to increase intracellular cAMP levels, completely prevented antiviral state induction by IFN-gamma, but had no effects on IFN-alpha/beta. Altogether these results demonstrate that IFN-gamma transduction signal is mediated by a G protein with functional characteristics similar to those of the known Gs protein.

Alprostadil↗
PubMedDate not supplied

[Antibiotic-resistant bacterial strains, their spread and social and economic implications].

The policies, laws, regulations governing the prescription and the use of antibiotics in 41 countries are examined. The enforcement of restrictions and the relations with the emergence of resistant strains are discussed. Emergence and spread of antibiotic-resistant bacteria result augmented in developing countries. Efforts to improves, in these nations, sanitation, nutrition, right information, education and usage of antibiotics must be taken into consideration.

Anti-Bacterial Agents↗
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[Bacterial resistance to antibiotics: biologic and ecologic aspects].

After a short introduction on bacterial resistance to the antibiotics and on the importance of the problem of emergence of the resistant strains, the mechanisms responsible are discussed. There are three major ways by which bacteria resist beta-lactam antibiotics; these include: altered outer membrane permeability, production of beta-lactamase and diminished affinity of the PbPs. Production of beta-lactamase is by far the most frequently encountered; for this reason there has been a major effort in the past 20 year to design new beta-lactam antibiotics, but on the other side bacteria elaborate constantly new strategies against new antibiotics. Moreover the use of antibacterial agents over the past half century has elicited a widespread deployment of genes for resistance in population of bacteria throughout the world and is conditioning the evolution of microbes.

Anti-Bacterial Agents↗
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[Diet and immunity].

Diet modulates the immune system and cell reactivity in particular since it may induce an early aging. A survey of published data on diet-immune system relationship is presented. Studies performed at the Institute of Microbiology, University of Turin, are discussed more in detail.

Aging↗
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[Retroviruses: current classification system].

Based on the various viral properties, the recent Retrovirus classifications are reported. After describing the HIV characteristics with the transactivation capability, the authors include the HIV among the Lentivirinae.

Animals↗
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[Vaginal microbial flora and infectious pathology].

Qualitative and quantitative studies in humans as well as animal models studies have confirmed that the vaginal flora is a dynamic and interrelated system. Factors influencing and changing vaginal ecology are considered. The disturbances in the vaginal flora may have impact on many infectious affections. Moreover the review examines concisely the microbial agents of the sexually transmitted diseases.

Bacterial Infections↗
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[The development of immunology in a century of research].

Immunology started in 1880 with the observation of Pasteur upon attenuated strains of Pasteurella aviseptica and evolved in nearly one century until the actual situation. Havig discussed the immunology topics, this review ends by stressing some of the recent landmarks in immunology.

Allergy and Immunology↗
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Production of polyclonal antibodies against the 40 kDa form of human 2'-5' oligoadenylate synthetase.

A 17-aminoacid peptide corresponding to the C terminal of the smaller form of human 2'-5' oligoadenylate synthetase was coupled to keyole lymphet haemocyanin (KLH) and used as immunogen in rabbits. After a cycle of four immunizations two animals produced immunoglobulins able to recognize the 17-aminoacid peptide as evaluated in ELISA assays. The specific Ig were purified by an immunoadsorbent with the peptide immobilized on Sepharose CL-4B and used in Western blot employing either protein A iodinated or conjugated with peroxidase as indicator system. The results obtained using extracts from HeLa or WISH cells treated for 15 hr with HuIFN-alfa as antigen demonstrate that the anti-peptide antibodies recognize the 40 kDa form of the 2'-5' oligoadenylate synthetase enzyme complex. These antibodies therefore represent a useful tool for monitoring the induction of the above enzyme.

2',5'-Oligoadenylate Synthetase↗
PubMedDate not supplied

[Cefonicid toxicity. I. Effects on the reactivity of the specific immune system].

The degree of toxicity of the antibiotic Cefonicid on the cellular reactivity of the immune system was evaluated. The effects on some lymphokine (IL-2 and IFN-gamma) production and the degree of proliferation of splenic lymphocytes following mitogen stimulation have been considered. Our results show that Cefonicid does not impair the immune response, except at very high doses (500 micrograms/ml).

Animals↗