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Biomedical subjects

M Divizia

Publications and source records attributed to M Divizia.

At least 55 records · Page 3Linked to original sources
PubMed1984

Lack of correlation between thymidine kinase activity and the antiviral or antiproliferative response to interferon.

Murine L cells lacking thymidine kinase activity (Ltk-) do not respond to the antiviral or antiproliferative activity of interferon, whereas human tk- cells show a normal response. Furthermore, a clone of tk+ cells derived from Ltk- cells by DNA-mediated transfer of the tk herpes gene does not respond to interferon. Cells of this clone and Ltk- cells do not produce interferon when infected with Newcastle disease virus or treated with poly(I) X poly(C) and DEAE-dextran. Possible reasons for this inability to produce interferon and the lack of response to interferon are discussed.

Animals↗
PubMed1983

Preliminary study on fixed rabies virus strain "Roma". I: Adaptation on BHK21/S13 cells.

In this study the attempts to adapt Roma fixed rabies virus to BHK21/S13 cells and human diploid fibroblasts, for a better characterization of the virus, are reported. BHK21 cells were infected with the virus and maintained in culture for more than 100 passages. A persistently infected culture by rabies virus was obtained. Attempts to propagate virus in human diploid fibroblasts were unsuccessful.

Adaptation, Physiological↗
PubMed1982

Cell-mediated immunity in human cytomegalovirus infection.

The direct leukocyte migration inhibition test, in response to cytomegalovirus stimulation, was used to study cell-mediated immunity in a group of children with cytomegalovirus infection. The test was impaired in children with chronic disease associated with cytomegaloviruria. In those cases with no viruria at the moment of the test, leukocyte migration inhibition was normal. Our data suggest that the acquired chronic cytomegalovirus infection may be sustained by a state of specific cellular desensitization, as already demonstrated for congenital infection.

Cell Migration Inhibition↗
PubMed1980

Abnormal behavior of interferon-induced enzymatic activities in an interferon-resistant cell line.

Interferon induces two double-stranded RNA-dependent enzymatic activities: an oligoisoadenylate synthetase that converts ATP to ppp(A2'p)n5'A, and a protein phosphokinase. We have explored the level and inducibility of these two enzymes in a human cell line (HEC-1) totally insensitive to both the antiviral and the anticellular actions of interferon. The activities of both enzymes are high in untreated cells and only minor changes occur after treatment with interferon, even at high concentrations. Interferon-treated HEC-1 cells do not contain an inhibitor of the oligoisoadenylate synthetase activity. The products of this HEC-1 oligoisoadenylate synthetase consist mainly of dimers, trimers, and tetramers as found in other cell lines after interferon treatment. The synthetase level is unaffected by treating the cells with anti-interferon antiserum, indicating that the results cannot be explained by a spontaneous low production of interferon by these cells. Furthermore, virus multiplication is not inhibited, even after treatment with interferon. These observations suggest that either the two enzymatic activities do not suffice for the establishment of an antiviral state in vivo or that a regulatory control mechanism, lost in these cells and common for both enzymes, is required for the expression of the antiviral action of interferon. This might explain both the constitutivity of the two enzymes and the interferon resistance observed.

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

Effect of isoflavans and isoflavenes on the infection of Frp/3 cells by hepatitis A virus.

The effect of 6,4'-dichloroflavan and of isoflavan and isoflavene derivatives on hepatitis A virus (HAV) infection in a monkey cell line (Frp/3 cells) was studied. These compounds were not virucidal and had no measurable effect on the adsorption of virus to the cells at 0 degrees C, whereas they exerted an inhibitory effect on viral antigen synthesis when incubated with the infected cells during HAV multiplication. Among the substances tested, 6,4'-dichloroflavan and 6,4'-dichloroisoflavan showed the highest activity. These compounds are postulated to interact with an early stage (penetration and/or uncoating) of HAV infection.

Antiviral Agents↗
PubMedDate not supplied

[Virus transmission in drinking water].

Several epidemiological data confirm the presence of enteric viruses in drinking water. The present paper deals with several problems tied to the virological analysis, such as the concentration of the samples, the isolation and the identification of enteric viruses.

Drinking↗
PubMedDate not supplied

[Health-related behaviour and HCV prevalence among elderly and younger adults in an isolated community close to Rome (Italy)].

The aim of this study has been to investigate the differences in the health-related behaviour by means of a questionnaire in a sample of elderly (>54 years, 1st generation) and younger adults (<54 years, 2nd generation, all of them sons/daughters of HCV positive subjects), given the high difference in HCV positive prevalence among the two groups (19.4% vs. 2.1%). Most (53.4% vs. 0.0%) of the 1st generation subjects used glass syringes while all the 2nd generation subjects used disposable syringes. Among the elderly, the frequency of hospitalisation (70% vs. 50%), transfusions (11.8% vs. 2.9%) and dental therapy by false dentists (52% vs. 0%) were higher. These results show that the use of non recyclable syringes is the main responsible for the drastic reduction of HCV circulation in the present community, and the consequent decrease in the risk for infection in younger subjects. Moreover, dental therapy was not related to an increased risk for infection, providing that the treatment has been made by a "true" dentist. Finally, the intrafamiliar transmission was not supported by the present data.

Adult↗
PubMedDate not supplied

[Enteric viruses and bacteriological parameters in molluscs].

Eighty-seven samples of shellfish were collected considering: type of mollusc, origin, growing area, monitoring or for human purpose. The bacteriological parameters were: Fecal Coliforms, Escherichia coli, and Salmonella; whereas the virological parameters included: Hepatitis A and E virus, Rotavirus, Astrovirus and Enterovirus. In total, 63.2% of samples had normal bacteria values, only one sample was Salmonella positive. The percentage of positive samples for Hepatitis A virus was 5.7%, Rotavirus 29.9%, Astrovirus 27.6%, Enterovirus 10.3%. The recovery of hepatitis E virus was always negative, whereas 13 samples (14.9%) were positive for two viruses.

Animals↗
PubMedDate not supplied

[Hygienic aspects of the Tiber river: presence of pathogenic protozoa and correlation with microbiological and physico-chemical parameters].

An investigation on the hygienic quality of the Tiber river was conducted with the aim both to enumerate Giardia cysts and Cryptosporidium oocysts in the water and to determine possible correlations between them and bacterial indicators, pathogens and physico-chemical parameters. A low hygienic water quality was evidenced, with high counts of microorganisms. Furthermore, variable concentrations of Giardia and Cryptosporidium were observed. No correlation was found between the protozoa concentrations and that of the other microorganisms, whilst a significant correlation with redox potential and Giardia cysts was calculated.

Animals↗