Search PubMed⌕ Search

Biomedical subjects

M Mariotti

Publications and source records attributed to M Mariotti.

At least 19 recordsLinked to original sources
PubMed1995

Correlation between viral DNA load and serum anti p19 antibody concentration in symptomless human T-lymphotropic virus type-I (HTLV-I)-infected individuals.

In order to determine whether serum anti-human T-cell lymphotropic virus type I (HTLV-I) antibody concentration is correlated with cellular viral DNA load, these 2 biological parameters were established in 22 symptomless HTLV-I carriers. The proviral copy (PVC) number was determined through quantificative polymerase chain reaction. Specific antibody titers were determined by Western blot with the end-point dilution method; the quantification of each antibody was performed through ScanBlot by determination of the peak height of each Western-blot band. A positive correlation was observed between the PVC number and the titer of total antibodies. When the association between the peak height of each antibody and the PVC number was studied, a significant positive correlation was observed only with anti-p 19. Further evaluation through follow-up studies of symptomless HTLV-I individuals is needed to clarify the value of anti-HTLV-I antibody titer as a predictor of disease progression.

Adult↗
PubMed1995

Albumin batches and B19 parvovirus DNA.

BACKGROUND: B19 parvovirus (B19) may be transmitted iatrogenically by blood, and its prevalence in blood donations is estimated at 1 in 3,300 to 1 in 50,000. As a large number of blood donations make up the plasma pools used to produce plasma derivatives, even a virus as rare as B19 in a population of blood donors may result in the frequent contamination of plasma batches. The percentage of albumin batches containing B19 DNA has never been determined. STUDY DESIGN AND METHODS: The presence of B19 DNA was investigated by a polymerase chain reaction assay (with a primer pair in the VP1 region) in a total of 12 and 17 batches of 4- and 20-percent albumin, respectively, from two different manufacturers. RESULTS: No B19 DNA was detected in the batches tested. CONCLUSION: The current fractionation process used to obtain these albumin preparations is seen to allow the efficient degradation and/or elimination of B19.

Base Sequence↗
PubMed1994

B19 parvovirus DNA in solvent/detergent-treated anti-haemophilia concentrates.

A transfusional B19 parvovirus infection may have severe consequences in immunocompromised hosts. The presence of B19 DNA was investigated with a polymerase chain reaction (PCR) assay in 30 batches of solvent/detergent-treated clotting factor concentrates (12 batches of factor VIII, 16 batches of factor IX, 1 batch of factor VII, and 1 batch of PPSB). B19 DNA was detected in 6 (20%) batches, including 3 factor VIII and 3 factor IX concentrates. Because of the frequency of B19 DNA in batches of clotting factors, measures to prevent transfusional risk of B19 infection via these blood products are justified, especially in recipients immunocompromised by HIV infection.

Blood Coagulation Factors↗
PubMed1994

Provirus copy number to predict disease progression in asymptomatic human immunodeficiency virus type 1 infection.

To evaluate the prognostic value of provirus copy number through quantitative DNA polymerase chain reaction (PCR) in early stages of human immunodeficiency virus type 1 (HIV-1) infection, 42 untreated and asymptomatic HIV-1-seropositive subjects with baseline CD4+ cell counts > 200 x 10(6)/L were included in a prospective study and followed over a median of 27 months. Disease progression was defined as decrease in CD4+ cells to < 200 (14 events). At enrollment, provirus copy number was associated with CD4+ cell count and percentage, serum IgA, and p24 antigenemia. Elevated provirus copy number above 20 allowed identification of patients at high risk of a subsequently decreasing CD4+ cell count, even after adjusting for baseline CD4+ cell count (P = .003). Measuring provirus copy number by PCR at early stages of HIV-1 infection could offer a useful early means to predict progression to AIDS.

Adult↗
PubMed1994

Prenatal diagnosis for the unstable CTG repeat sequence in myotonic dystrophy: a retrospective study in a French family.

The results of DNA analysis for the unstable CTG repeat are reported in a french family of myotonic dystrophy. This retrospective study confirms results obtained previously with a linked DNA marker, using the CTG repeat DNA sequence in the same family. The demonstrated possibility of predicting phenotype as well as genotype in prenatal diagnosis is important for such a disorder, were subjects may be severely affected.

Adult↗
PubMed1992

Human T lymphotropic virus (HTLV) type I and II DNA amplification in HTLV-I/II-seropositive blood donors of the French West Indies.

To confirm the presence of DNA from human T lymphotropic virus type I (HTLV-I), HTLV-II, or both in individuals found HTLV-I/II-positive through systematic screening of blood donations in Guadeloupe (French West Indies), 42 blood donors repeatedly positive for HTLV-I/II by ELISA were studied by polymerase chain reaction (PCR). Three primer pairs (env, pol, tax) targeted on conserved regions of HTLV-I or -II sequences (or both) and six probes (two generic, two HTLV-I-specific, two HTLV-II-specific) were used in a multiplex PCR. HTLV-I sequences were detected in 31 individuals (74%). All 31 subjects positive by Western blot (WB) harbored HTLV-I sequences. Fifteen individuals (48%) were positive with the three primer pairs used, 10 (32%) with two, and 6 (20%) with one. Subjects indeterminate or negative by WB were all negative by PCR. No HTLV-II sequences were detected with specific probes. The results indicate the absence of HTLV-I and -II infection in individuals with indeterminate WB, the presence of HTLV-I DNA in individuals positive for WB in the French West Indies, and the absence of HTLV-II infection in the cohort.

Adult↗
PubMed1992

Multicentre quality control of polymerase chain reaction for detection of HIV DNA.

OBJECTIVE: Seven French laboratories tested the specificity and sensitivity of the polymerase chain reaction (PCR) for the detection of HIV-1 DNA. METHODS: Following its own PCR protocols, each laboratory independently tested blind two panels of 20 coded peripheral blood mononuclear cell samples collected from HIV-1-seropositive individuals and from HIV-1-seronegative individuals at high or low risk of HIV infection. For the first panel, laboratories were free to select type and number of primers; for the second, all were required to use the two primer pairs Pol 3/4 and MMy 9/10' (Nef 1). RESULTS: False-positive and false-negative results were observed in all laboratories (concordance with serology ranged from 40 to 100%). In addition, the number of positive PCR results did not differ significantly between high- and low-risk seronegatives. The use of crude cell lysates in DNA preparation produced the same PCR results as phenol-extracted DNA. Discrepancies between laboratories indicated that factors other than primer pairs contributed strongly to laboratory variability. CONCLUSIONS: Our results emphasize the importance of both positive and negative controls in PCR and demonstrate the value of multicentre PCR quality control.

Base Sequence↗
PubMed1992

Towards a new predictor of AIDS progression through the quantitation of HIV-1 DNA copies by PCR in HIV-infected individuals.

The proviral copy (PVC) number in peripheral blood mononuclear cells (PBMCs) of human immunodeficiency virus (HIV)-infected individuals was measured by a quantitative polymerase chain reaction (PCR) assay to determine over time the relation between the viral load and the evolution towards the disease in HIV-infected people: 67 anti-HIV-1 positive individuals (60 stage II/III, 7 stage IV) were studied. The mean PVC number per 1.5 x 10(5) PBMCs in stage II/III individuals (14.4 +/- 14.2) and in stage IV individuals (32.2 +/- 22.9) was significantly different (P < 0.02). PVC number was inversely correlated to the CD4 lymphocyte count (P < 0.01). In the logistic regression, the PVC number was a better marker of evolution towards the disease than the CD4 lymphocyte count. The mean proportion of HIV-infected PBMCs in stage IV individuals and in stage II/III individuals was 1/4606 and 1/10714, respectively.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Quantification of HTLV-1 proviral copy number in peripheral blood of symptomless carriers from the French West Indies.

The development of human T-cell leukemia type 1 (HTLV-1) diseases are related to an increase in the proviral copy number (VCN) in peripheral blood mononuclear cells (PBMCs). Twenty symptomless anti-HTLV-1-positive blood donors, as well as four symptomatic individuals, all from the French West Indies, were studied. The VCN in PBMCs was determined by quantitative PCR. The VCN values for asymptomatic HTLV-1 carriers (range of less than 100 to approximately 9,500/micrograms of DNA) was nearly always less than the values for symptomatic carriers (range of approximately 5,500 to approximately 29,000/micrograms of DNA). Consequently, the proportion of HTLV-1-infected PBMCs in symptomless and in symptomatic individuals ranged from less than 1/1,500 to approximately 1/16 and approximately 1/27 to approximately 1/5, respectively. No correlation could be found between VCN and age or sex, suggesting the importance of factors other than age and sex as influences on the VCN number.

Adult↗
PubMed1991

No evidence of HIV-1 infection in seronegative hemophiliacs and in seronegative partners of seropositive hemophiliacs through polymerase chain reaction (PCR) and anti-NEF serology.

We prospectively studied a well-characterized cohort including 60 seronegative hemophiliacs or von Willebrand's disease patients, 6 seronegative female sexual partners of seropositive hemophiliacs, 59 seropositive hemophiliacs or von Willebrand's disease patients and 2 seropositive partners of seropositive hemophiliacs (used as positive controls), and 117 seronegative low risk individuals (used as negative controls). PCR assay, performed in peripheral blood mononuclear cells using three primer pairs in the gag, pol, LTR regions, showed no positive results in the 60 seronegative patients, in the 6 seronegative partners of seropositive patients and in the 117 seronegative low risk individuals, while PCR was positive with at least one primer pair in 53 (87%) of 61 seropositive patients. Anti-nef serology (Western-blot) was negative in seronegative patients, in seronegative partners of seropositive patients and positive in 58% out of the seropositive individuals. These results strongly suggest an absence of HIV-1 infection in individuals with a lastingly negative HIV serology.

Base Sequence↗
PubMed1991

No evidence of HTLV-I infection in French patients with multiple sclerosis using the polymerase chain reaction.

The polymerase chain reaction (PCR), using three primer pairs in the pol, tax, and env regions of the HTLV-I genome, was unable to detect HTLV-I in the blood samples of 54 caucasian subjects with multiple sclerosis who were seronegative for HTLV-I/II. Seventeen HTLV-I/II seropositive (by ELISA and Western blot) subjects used as positive controls were positive with the three primer pairs. The PCR was negative in 47 healthy HTLV-I/II seronegative (by ELISA) subjects at low risk of HTLV-I infection used as negative controls. These results suggest that there is no association between the occurrence of HTLV-I sequences and the development of multiple sclerosis.

Adult↗
PubMed1991

Polymerase chain reaction (PCR) in various stages of HIV infection. Relationship to disease progression.

In order to establish whether the Polymerase Chain Reaction (PCR) may constitute a new marker of evolution towards AIDS in symptomless HIV infected subjects, we used PCR with three primer pairs (in the gag, pol and LTR regions) in 223 seropositive individuals at different stages of HIV infection. Among 176 symptomless seropositive individuals, 174 (98.8%) were positive with at least one primer pair. The subjects negative with at least one primer pair had a CD4 lymphocyte count significantly higher (p less than 0.01), and serum immunoglobulin G, immunoglobulin A, neopterin and beta-2-microglobulin concentrations significantly lower (p less than 0.01) than the individuals positive with the three primer pairs. Among 73 seropositive individuals followed over a two year period, 59 presented the same PCR pattern over this time period, while PCR showed different results in 14. Forty-seven AIDS patients were positive with the three primer pairs. The number of PCR negative with at least one primer pair was significantly fewer (p less than 0.001) in symptomatic individuals than in symptomless individuals. We conclude that the percentage of positive PCR results in HIV infected individuals is linked to the clinical stage of infection and to the disease progression.

Acquired Immunodeficiency Syndrome↗