Biomedical subjects

A D'Aprile

Publications and source records attributed to A D'Aprile.

6 recordsLinked to original sources

PubMed2006

Mitochondrial dysfunction in hepatitis C virus infection.

The mechanisms of liver injury in chronic hepatitis C virus (HCV) infection are poorly understood though HCV induces a state of hepatic oxidative stress that is more pronounced than that present in many other inflammatory diseases. This mini-review will focus on recent findings revealing an unexpected role of mitochondria in providing a central role in the innate immunity and in addition will illustrate the application of stably transfected human-derived cell lines, inducibly expressing the entire HCV open reading frame for in vitro studies on mitochondria. Results obtained by a comparative analysis of the respiratory chain complexes activities along with mitochondrial morpho-functional confocal microscopy imaging show a detrimental effect of HCV proteins on the cell oxidative metabolism with specific inhibition of complex I activity, decrease of mtDeltaPsi, increased production of reactive oxygen species. A possible de-regulation of calcium recycling between the endoplasmic reticulum and the mitochondrial network is discussed to provide new insights in the pathogenesis of hepatitis C.

Gene Expression Regulation, Viral↗

PubMed2002

Chlamydia pneumoniae in community-acquired pneumonia: seven years of experience.

OBJECTIVES: To determine the prevalence of Chlamydia pneumoniae in community-acquired pneumonia during a period of seven years. METHODS: Serum samples from 311 patients with pneumonia were evaluated using microimmunofluorescence assay to detect C. pneumoniae -specific IgG and IgM antibodies. RESULTS: Thirty nine patients (12.5%) complied with the diagnostic criteria of acute C. pneumoniae infection (a four-fold rise in the titer of IgG antibody, or a single IgG titer > or = 1:512, or a single IgM titer > or = 1:16). All patients were diagnosed as having pneumonia. Co-infection with other respiratory tract pathogens was found in four patients. CONCLUSIONS: C. pneumoniae is an important cause of pneumonia also in our area. Pneumonia due to this bacterium occurs in the cold months and in early spring; in addition we have observed periods of increased incidence of one years duration and periods of low incidence lasting one-two years. Therapy with macrolides and levofloxacin was effective in all patients with C. pneumoniae infection.

Anti-Bacterial Agents↗

PubMed2002

Comparison of two microimmunofluorescence tests for detecting antibodies to Chlamydia pneumoniae.

Two microimmunofluorescence (MIF) tests were compared for detection of antibodies to Chlamydia pneumoniae: the microimmunofluorescence of Washington University and the microimmunofluorescence of Chlamydia Serofia. Concordant positive results at the same dilution were observed for IgG in 37.33% of sera tested and concordant negative results were found in 44%. Variations of one fold dilution were observed in 36 sera. Extensive variations (2-3 two-fold dilutions) in the numeric titer values were observed in 20 serum samples with titers of antibody generally higher in the Chlamydia Serofia MIF than in the Washington MIF, resulting in a diagnosis of current infection in three patients. IgM were found with both methods only in one patient. The discrepancies observed may be due to several factors including the different TWAR strain used as antigen in the two tests and the dilution of the FITC-labelled conjugated anti-human IgG. We think that MIF serology may also be influenced by the type of response of the host that may depend on the "local strain" of C. pneumoniae that may express different antigens or in different amounts in comparison with the strains used by the commercial kit.

Antibodies, Bacterial↗

PubMed2001

Chlamydia trachomatis and Mycobacterium tuberculosis lung infection in an HIV-positive homosexual man.

A 31-year-old homosexual man, who was human immunodeficiency virus (HIV)-positive was admitted for fever and cough. Chest computed tomography (CT) revealed the presence of diffuse interstitial reticular nodulation, and brain nuclear magnetic resonance imaging showed the presence of nodular frontal lesions. Microscopic examination of sputum and other body fluids showed the presence of acid-fast bacilli and culture-only growth Mycobacterium tuberculosis. Serology for respiratory tract pathogens was negative except for Chlamydia. An antibody titer in the immunoglobulin G (IgG) class of 1:64 for Chlamydia pneumoniae and, unexpectedly, an antibody titer of 1:1024 for C. trachomatis were found. The patient was successfully treated with antituberculosis agents, and clarithromycin, for presumptive chlamydial infection.

AIDS-Related Opportunistic Infections↗

PubMedDate not supplied

Regulation by the cAMP cascade of oxygen free radical balance in mammalian cells.

A study is presented of the effect of the cAMP cascade on oxygen metabolism in mammalian cell cultures. Serum-starvation of the cell cultures resulted in depression of the forward NADH-ubiquinone oxidoreductase activity of complex I, decreased content of glutathione, and enhancement of the cellular level of H2O2. Depressed transcription of cytosolic Cu/Zn-SOD 1, mitochondrial glutathione peroxidase and catalase was also observed. Activation of the cAMP cascade reversed the depression of the activity of complex I and the accumulation of H2O2. The effect of cAMP involved the cAMP-dependent protein kinase.

Animals↗

PubMedDate not supplied

[Neurotoxic effect of 7,8-oxide styrene on striatal neuron culture].

The present study was undertaken to test the hypothesis that the neurotoxic action of styrene may be primarily presynaptic in nature and may involve impaired regulation of DA content and stimulation of DA release. Primary striatal neurons were grown in vitro and exposed to styrene oxide at different concentrations to evaluate the minimal effective dose able to induce these synaptic alterations.

Animals↗