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C Vignoli

Publications and source records attributed to C Vignoli.

At least 19 recordsLinked to original sources
PubMed2006

Inactivation of a European strain of West Nile virus in single- donor platelet concentrate using the INTERCEPT blood system.

BACKGROUND AND OBJECTIVE: In order to prevent West Nile virus (WNV) contaminations by transfusion, the French National Blood Service decided to evaluate the INTERCEPT Blood System's efficiency on a European strain. MATERIALS AND METHODS: Culture supernatant of WNV was used to infect six platelets concentrates. Viral titre was determined by plaque reduction neutralization test before and after viral inactivation using the INTERCEPT Blood System. RESULTS: In all assays, the absence of plaque forming unit was observed after viral inactivation. The log reduction observed ranged between > 5.1 logs to > 5.2 logs. CONCLUSION: INTERCEPT Blood System is a commercially viral inactivation method potentially useful in order to prevent WNV transmission by blood products in France during re-emerging outbreaks.

Blood Donors↗
PubMed1998

Prevalence of JC virus viraemia in HIV-infected patients with or without neurological disorders: a prospective study.

Progressive Multifocal Leukoencephalopathy (PML) is a severe demyelinating disease, which is rapidly fatal and is due to JC virus (JCV) infection, which especially occurs in HIV-infected patients. To investigate JCV pathophysiology and to evaluate the predictive value of JCV detection in blood, we looked for JCV DNA in leukocytes and plasma of 96 patients without any neurological symptoms and 109 patients with neurological diseases, among whom 19 were suffering from PML. JCV genome was detected in about 18% of all patients, i.e. 15.6% of patients with central nervous system disorders except PML, 13.5% of patients without neurological symptoms and significantly more often in PML patients (47.6%). Both leukocytes and plasma were tested; in plasma, JCV DNA was found in 36.1% of positive patients and in cells in 80.5%. Surprisingly in seven instances only the plasma contained JCV genome. One-year follow-up of these patients showed that the absence of JCV DNA in blood was associated with a very low probability of developing PML (negative predictive value=0.99).

Blotting, Southern↗
PubMed1994

Comparison of viral burden and phenotype of HIV-1 isolates from lymph nodes and blood.

OBJECTIVE: To compare the viral burden and the biological phenotype of HIV-1 isolates obtained from lymphoid node mononuclear cells (LNMC) and peripheral blood mononuclear cells (PBMC) in 11 HIV-infected patients. METHODS: Viral burden was quantified by cocultivating LNMC and PBMC from HIV-infected patients with PBMC from seronegative donors. For each patient, LNMC and PBMC isolates were characterized in terms of susceptibility to neutralizing antibodies, syncytium-inducing capacity and sensitivity to zidovudine. RESULTS: Our data show that: (1) viral burden was 1.73 log higher in LNMC than PBMC in patients with persistent generalized lymphadenopathy and only 0.37 log higher in patients with AIDS-related complex; (2) five out of 11 LNMC bulk isolates were phenotypically distinct from autologous PBMC isolates; (3) in three patients, the autologous serum neutralized the PBMC isolates but not the LNMC isolates. CONCLUSIONS: These results suggest that the relatively high level of HIV-1 replication in lymph nodes may favour the emergence of viruses exhibiting specific phenotypes, including neutralization escape variants. The existence of viral variants in lymphoid tissue at all stages of HIV infection may elucidate certain aspects of the pathogenesis of HIV-1 infection.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Improved current methods for amplification of DNA from routinely processed liver tissue by PCR.

With both a classic DNA preparation protocol (including removal of paraffin wax and protein digestion) and a DNA extraction protocol with Chelex 100, the hepatitis B virus genome was searched for using the polymerase chain reaction (PCR) in 30 samples of paraffin wax embedded liver tissue from patients with chronic hepatitis. The classic protocol was more sensitive than the rapid Chelex 100 procedure (10 v six positive samples). A third protocol, including removal of paraffin wax, protein digestion, and Chelex 100 treatment of the digestion solution before PCR, was more sensitive than the others (16 positive samples). It is concluded that it could therefore be helpful for PCR analysis of paraffin wax embedded liver tissue.

Base Sequence↗
PubMed1994

Correlation between surrogate markers, viral load, and disease progression in HIV-1 infection.

Surrogate markers generally used for observation of patients infected with human immunodeficiency virus (HIV) and their plasma and cellular viral load were assayed in a series of 40 patients before initiation of zidovudine therapy. Plasma viremia was positive in 62.5% of patients and was statistically correlated with clinical stage, CD4+ T cell count, CD8+ T cell count, beta 2-microglobulin level, neopterin level, and immunoglobulin A level. Cellular viremia was positive in 95% of patients and was correlated with clinical stage, CD4+ T cell count, beta 2-microglobulin, neopterin levels, and disease progression during the following months. A discordance was found between p24 antigenemia, even after acid dissociation of immune complexes, and plasma viremia. In fact, p24 antigenemia was correlated with only biological markers of immune activation as beta 2-microglobulin and neopterin levels. The measurement of anti-p24 antibodies did not appear discriminative in our staging. Plasma viremia, like CD4+ T cell count, reflects the patient's status at the time of assessment. Cellular viremia could be more informative for the prediction of future clinical progression.

Adult↗
PubMed1993

Detection of JC virus by polymerase chain reaction and colorimetric DNA hybridization assay.

A procedure for rapid detection of JC virus (JCV) using the polymerase chain reaction is described. The procedure was tested in eight HIV-1-seropositive patients with progressive multifocal leukoencephalopathy. One-step DNA extraction using a chelating resin was carried out on clinical samples of cerebrospinal fluid (CSF), urine and brain tissue. After amplification, PCR products were detected by a DNA hybridization method. Microplates were coated with a specific probe and hybridized PCR products were revealed by a commercial colorimetric immunoassay. Using this procedure JC virus DNA was detected in all CSF specimens from patients with progressive multifocal leukoencephalopathy. This sensitive and rapid (24 h) procedure could greatly facilitate use of the DNA probe assay for detection of JC virus in clinical laboratories.

Colorimetry↗
PubMed1992

[Identification of Mycobacterium tuberculosis and Mycobacterium avium by non-radioactive probes: evaluation of the Snap Syngene system].

We evaluated an alkaline phosphatase-labeled oligonucleotide probe for the rapid identification of Mycobacterium tuberculosis and mycobacteria belonging to the M avium and M intracellulare complex (MAIS). Sixty-two strains of mycobacteria and eight strains belonging to related genera were studied. All M tuberculosis strains hybridized with the tuberculosis probe. All M avium and M intracellulare gave a strong signal with their probes. However the 3 M xenopi strains tested hybridized with all probes for MAIS complex.

DNA Probes↗
PubMed1992

Detection and identification of Mycobacterium tuberculosis, M. bovis/BCG, and M. avium by two-step polymerase chain reaction. Comparison with ELISA using A60 antigen.

We propose a rapid two-step PCR to amplify a 767-bp sequence present in the gene coding for the 65-kD antigen of mycobacteria. The high G+C content (80%) permitted annealing to occur at 70 degrees C, enhancing the specificity. The amplified fragment contains a restriction site for differentiation between M. tuberculosis, M. bovis/BCG, and M. avium. Complete diagnosis can be achieved in less than four hours without labelled probe or nucleic acid transfer.

Antigens, Bacterial↗
PubMed1992

Molecular cloning of a specific DNA probe for the identification of Bacillus licheniformis.

Bacillus licheniformis has been found to be one of the dominant nosocomial species of Bacillus: laboratories dealing with nosocomial infections must be able to identify Bacillus up to the species level. To date, no DNA probes have been isolated for B. licheniformis although there is a clear need for a direct detection by polymerase chain reaction. The isolation of a B. licheniformis-specific DNA probe, as described in this paper, represents the first step toward accomplishing this goal.

Bacillus↗