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Biomedical subjects

A Monnet

Publications and source records attributed to A Monnet.

14 recordsLinked to original sources
PubMed2005

Risk of cancer after low doses of ionising radiation: retrospective cohort study in 15 countries.

OBJECTIVES: To provide direct estimates of risk of cancer after protracted low doses of ionising radiation and to strengthen the scientific basis of radiation protection standards for environmental, occupational, and medical diagnostic exposures. DESIGN: Multinational retrospective cohort study of cancer mortality. SETTING: Cohorts of workers in the nuclear industry in 15 countries. PARTICIPANTS: 407 391 workers individually monitored for external radiation with a total follow-up of 5.2 million person years. MAIN OUTCOME MEASUREMENTS: Estimates of excess relative risks per sievert (Sv) of radiation dose for mortality from cancers other than leukaemia and from leukaemia excluding chronic lymphocytic leukaemia, the main causes of death considered by radiation protection authorities. RESULTS: The excess relative risk for cancers other than leukaemia was 0.97 per Sv, 95% confidence interval 0.14 to 1.97. Analyses of causes of death related or unrelated to smoking indicate that, although confounding by smoking may be present, it is unlikely to explain all of this increased risk. The excess relative risk for leukaemia excluding chronic lymphocytic leukaemia was 1.93 per Sv (< 0 to 8.47). On the basis of these estimates, 1-2% of deaths from cancer among workers in this cohort may be attributable to radiation. CONCLUSIONS: These estimates, from the largest study of nuclear workers ever conducted, are higher than, but statistically compatible with, the risk estimates used for current radiation protection standards. The results suggest that there is a small excess risk of cancer, even at the low doses and dose rates typically received by nuclear workers in this study.

Dose-Response Relationship, Drug↗
PubMed2004

Evaluation of a prototype HCV NS5b assay for typing strains of hepatitis C virus isolated from Tunisian haemodialysis patients.

Hepatitis C virus (HCV) strains isolated from 68 haemodialysis Tunisian patients exhibiting chronic infection were genotyped targeting the NS5b region of the HCV genome using a prototype assay developed by Bayer HealthCare-Diagnostics (TRUGENE NS5b HCV). The overall results were compared to those obtained with another assay of the same company based on sequencing of the 5' non-coding region (TRUGENE HCV 5'NC genotyping kit). All strains could be typed by the 5'NC typing kit, but only 62 (91; 2%) by the NS5b prototype assay. All the 62 strains typed by both methods exhibited the same pattern at the type level: 57 were type 1, 3 were type 2, and 2 were type 4. At the subtype level, eight strains that gave undetermined results by the 5'NC kit were successfully typed by the NS5b kit; eight additional strains exhibited discrepant results. The overall agreement between the two assays was 74.2% at the subtype level. In conclusion, the NS5b region appears to be much more accurate than the 5'NC region to subtype HCV strains, especially in those isolated from patients attending haemodialysis centres where the subtype distribution suggests frequent nosocomial transmissions.

5' Untranslated Regions↗
PubMed2000

Genotyping of hepatitis C virus isolates using CLIP sequencing.

Determination of hepatitis C virus (HCV) genotypes and subtypes has become increasingly important for the clinical management and prognosis of HCV infections. The aim of the present study was to assess the specificity and reliability of a newly developed, commercially available HCV genotyping kit (TRUGENE HCV 5'NC genotyping kit). This technique utilizes PCR fragments previously generated by the diagnostic Roche AMPLICOR HCV test, which are subsequently subjected to simultaneous PCR amplification and direct sequencing (CLIP sequencing) of the 5' noncoding region (5'NCR). HCV isolates from 100 randomly chosen patients were genotyped by both the TRUGENE HCV 5'NC genotyping kit and DNA enzyme immunoassay (DEIA). Typing results obtained by both methods were in complete concordance in 91% of the cases. HCV RNA from the samples with discordant genotype assignment in both assays was additionally amplified with primers from the HCV core and NS5B regions. Phylogenetic analysis of the obtained sequences supported the results obtained from DEIA in six cases and CLIP sequencing in two cases. In the former six cases, the TRUGENE HCV 5'NC genotyping kit could not correctly differentiate between subtypes of genotypes 1 and 2 due to the high conservation of the 5'NCR. However, since there was not any misclassification between HCV genotypes 1 and non-1 types, the results obtained with this system are, in general, reliable and can be used in clinical practice. The TRUGENE HCV 5'NC genotyping kit in our hands proved to be a fast and convenient technique that might be an attractive option for HCV genotyping in laboratories already using the Roche AMPLICOR HCV test for diagnostic reverse transcription-PCR.

5' Untranslated Regions↗
PubMed1978

[Some aspects of the allelic interaction in family studies of normal A1B and A2B subjects (author's transl)].

The authors have selected three series of families presenting several heterozygous AB gene combinations: the same gene A and the same gene B; the same gene B and different genes A; and the same gene A and different genes B. The results concerning these families show that the quantitiy of A1 and A substances (for A1B) or A (for A2B) is related to the "quality" of the alpha-D-galactosyl transferase acting on a more or less important H substratum. The alpha-N-acetyl-D-galactosaminyl transferase seems to have a minor function.

ABO Blood-Group System↗
PubMed1978

Automatized hemagglutination kinetics.

An automatized technique for the study of hemagglutination kinetics is described. It was used to differentiate between homozygous and heterozygous individuals in the Rh system. Other applications are proposed.

ABO Blood-Group System↗
PubMed1977

A quantitative study of the ABH red cell antigens in the Kulamwo of Ivory Coast.

The agglutination percentages given by various erythrocytes with reference sera have been compared in blood samples from Kulamwos living in the Ivory Coast and of blood donors of the regional transfusion centre of Toulouse. The study of O, A, B and AB phenotypes shows: 1. in O Kulamwos a higher agglutination percentage with anti-H than in Toulousains; 2. in B Kulamwos a higher agglutination percentage with anti-B than in Toulousains; 3. in A Kulamwos a very marked frequency of A intermediate which can be classified in different categories due to the variability of their agglutination percentage with anti-A1 and anti-H sera.

ABO Blood-Group System↗
PubMed1976

[Conversion of chimpanzee O-erythrocytes into B-erythrocytes by human alpha galactosyltransferase].

The red blood cell antigens of the ABO system are not present in all the anthropïd Primates. The Chimpanzee, particularly, shows only the two genes A and O. The alpha-galactosyl transferase, present in the human sera of group B, has been used to fix a molecule of galactose on O red cells of Chimpanzee giving them a B specificity. If the B gene was present in the Chimpanzee it could consequently be expressed on the erythrocytes. This gene, probably present in an ancestor common to the anthropoïd apes and to Man disappeared in the Chimpanzee, perhaps at the origin of species.

ABO Blood-Group System↗
PubMed1975

Quantitative study of the ABO system in several groups of African populations.

Agglutination percentages of red blood cells from European and from three African populations (Twareg from Mali, Sara from Central African Republic, and Niokholonko from Senegal) in the ABO system have been compared. The results show a greater agglutinability of group O erythrocytes with anti-H sera, for African subjects than for Europeans. No significant difference was noted between African and European B subjects, except for the Niokholonko, whose agglutination percentage was slightly higher with anti-B. The study of group A disclosed a large number of Aint in all African populations studied. The AB African red cells seem to be less agglutinable with anti-A and anti-A1 sera than European ones; A and A1 antigens may be depressed by a strong B antigen.

ABO Blood-Group System↗
PubMedDate not supplied

[Relationship between the quantities of H substance before, and B substance after conversion of red blood cells by alpha-D-galactosyl transferase].

The authors determined the agglutination percentages with anti-B, eel and Ulex europeus anti-H reagents for the kinetic study of the in vitro conversion O red blood cells in B. The agglutination with the anti-B increases in proportion as the agglutination with eel anti-H decreases; the agglutination with Ulex anti-H remains constant. They converted (time=18 h) O red blood cells with a more or less high substance H content (adults in good health, africans and europeans, patients, newborn and one "Bombay" phenotype). They showed that there is a good correlation between the agglutination percentages with eel anti-H or Ulex anti-H before conversion and the agglutination percentages with anti-B after conversion. These "O converted" look like the B phenotype defined by a check sample of B subjects.

ABO Blood-Group System↗