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Biomedical subjects

L Noel

Publications and source records attributed to L Noel.

At least 19 recordsLinked to original sources
PubMed2002

Multivariate analysis of determinants of bacterial contamination of whole-blood donations.

BACKGROUND AND OBJECTIVES: Introduction of bacteria into blood components at the collection stage seems to be a frequent occurrence. We therefore assessed determinants of bacterial contamination of whole-blood donations to gain insight into contamination mechanisms and direct prevention. MATERIALS AND METHODS: A cross-sectional study was carried out on donors accepted for whole-blood donation in four French blood banks. Each blood bank used its own two-stage procedure for phlebotomy site preparation. Contamination was identified by culturing two 15-ml samples (collected aseptically at the outset of donation) in a BacT/Alert 240 system. Determinants were assessed by logistic regression analysis. RESULTS: Bacterial contamination, mainly by skin flora, occurred in 76 (2.2%) out of 3385 donations. Significant determinants were as follows: the blood bank (odds ratio [OR] range = 3.0-5.6, P < 0.001); lack of repetition of scrub (OR = 2.7, P = 0.032); and donor age > 35 years (OR = 1.8, P = 0.036). CONCLUSION: Systematic scrub repetition should be implemented to reduce bacterial contamination by skin flora at the collection stage. Further research is required to clarify the role of different antiseptic agents and of donor age.

Adult↗
PubMed2001

Efficacy of a new collection procedure for preventing bacterial contamination of whole-blood donations.

BACKGROUND: Transfusion-related bacterial contamination is a serious problem. The introduction of bacteria into donations at the collection stage seems frequent, despite well-conducted phlebotomy site preparation. Additional preventive measures are required. STUDY DESIGN AND METHODS: The aim of this study was to assess the potential efficacy of excluding the first 15 mL of blood to reduce the bacterial contamination of donations. A special device allowed the aseptic collection of two samples at the beginning of donation: S1 (first 15 mL) and S2 (next 15 mL). Bacteriologic cultures of S1 and S2 were performed by using an automated system. The procedure's efficacy was measured by the proportion of positive donations in S1 that were then negative in S2. RESULTS: S1 and/or S2 were positive in 76 (2.2%) of 3385 donations. In about three-fourths of the culture-positive donations, contamination was detected in the first 15-mL sample only. Gram-positive cocci accounted for 81 percent of species, gram-positive bacilli for 14 percent, and gram-negative bacilli for 5 percent. The new procedure would have prevented the introduction of bacteria in 55 donations, reducing to 0.6 percent the risk of contamination from the first 15 mL collected. CONCLUSION: Although the final effect on blood component bacterial contamination rates cannot be derived from the study, excluding the first 15 mL of blood may reduce the rate of bacterial contamination in donations.

Adult↗
PubMed1999

The French haemovigilance system.

Haemovigilance is a national system of surveillance and alarm, from blood collection to the follow-up of the recipients, gathering and analysing all untoward effects of blood transfusion in order to correct their cause and prevent recurrence. In France haemovigilance was created by law and notification of transfusion incidents is a legal obligation. The haemovigilance network associates local correspondents in each hospital and blood centre with regional co-ordinators and is centralised by the Agence Française du Sang. After 4 years the incident reporting rate is 2.3 per 1,000 allogeneic blood components transfused, justifying for example increased efforts in the prevention of bacteria-associated transfusion reactions, haemolytic transfusion reactions or vascular overload. However, haemovigilance still has to be strenghtened by improved information management or further progress in standardisation from one region to the other. The most important factor of success is collaboration between blood centres and hospitals. Haemovigilance clearly is the ultimate quality indicator of a transfusion service.

Blood Banks↗
PubMed1998

The French haemovigilance system.

Haemovigilance was part of the reform of the French transfusion system. The haemovigilance network is now operational with approximately 4600 transfusion incidents reported annually. Immediate incidents observed within 8 days after transfusion account for 85% of the reports. A cause cannot be identified in 41% of these, usually concerning minor clinical incidents with transient fever and/or shivers. An allergic reaction is described in 31% of transfusion reactions. Immunological conflicts account for 18% and bacteria associated transfusion reactions for 6%. The importance of bacteria associated transfusion reactions, the first identified cause of death associated with transfusion is one of the findings of haemovigilance. Improvement in the haemovigilance systems aims at obtaining better descriptions of transfusion incidents, standardisation of severity and imputability assessment and definitions of denominators such as the actual number of recipients. Delayed incidents will ultimately provide a true vision of post transfusion immunisation and infection The improvement of haemovigilance now considered as part of transfusion medicine practice is a continuous process.

Bacteremia↗
PubMed1998

A comparative evaluation of the sensitivity of five anti-hepatitis C virus immunoblot assays.

BACKGROUND AND OBJECTIVES: In order to compare sensitivity, five anti-hepatitis C virus (HCV) immunoblot assays were tested (Deciscan plus, Inno-Lia III, Matrix, Murex Western blot and RIBA-3). MATERIALS AND METHODS: The test panel (50 samples for each assay) included 6 anti-HCV-negative samples and 44 samples from 36 HCV-infected subjects. RESULTS: There were minor differences in core reactivity among the assays. The smallest number of NS3-reactive results occurred with the Murex and Matrix assays, and the smallest number of NS4 reactives with RIBA-3 and Matrix. Among the 20 discrepant results for NS5 there was one clear false-negative with Inno-Lia. Only 28 of the 50 samples of the panel gave the same results in all the assays: 5 negatives and 23 positives. One of the 6 negative samples were indeterminate in 3 assays. Eighteen of the 21 other divergent results were interpreted as either indeterminate or positive, a common reactivity being exhibited by all 5 assays. The most important discrepancies occurred on 3 HCV-RNA-positive samples which came up negative in some assays: 2 samples with isolated NS3 reactivity were negative by Matrix and Murex Western blot, 1 of them being also negative by Inno-Lia III; another sample was negative by RIBA-3 and Matrix due to weak signals (< 1) on core and NS3 proteins, which did not exceed 1+ with the other assays. CONCLUSIONS: With more uniform criteria for interpretation, the results would have been less divergent. Some assays should improve their sensitivity to the NS3 protein.

Evaluation Studies as Topic↗
PubMed1995

Radiocesium body burdens in immigrants to Israel from areas of the Ukraine, Belarus and Russia near Chernobyl.

Of the 500,000 immigrants from the former Soviet Union who came to Israel during 1990-1993, about 100,000 are estimated to have come from radiocontaminated areas near Chernobyl. These people were subject to chronic uptake of environmental radiocesium over protracted periods. During October-November 1991, a joint Israeli-Canadian investigation measured radiocesium body burdens in immigrants to Israel from the Ukraine, Belarus, and the southern Russian republic in order to provide factual information on radiocesium levels to concerned immigrants and to relate the body burdens to the geographic area of residence before coming to Israel. Assessments were made of 137Cs body burdens in 1,228 volunteer men, women, and children. These measurements were accompanied by medical assessments based on clinical histories and examinations. Radiocesium levels were strongly dependent on the duration of residence in Israel, with the highest levels being found in the most recent immigrants. The maximum level, extrapolated back to the time of leaving the former Soviet Union, was estimated to be about 0.83 kBq (10.3 Bq kg-1). Of the most recent immigrants from the Kiev region (< 101 days in Israel), only 15% had back extrapolated body burdens > 50 Bq, whereas 53% of those coming from Gomel and other towns in the contaminated zones (> 3.7 x 10(10) Bq km-2 of radiocesium) had detectable levels > 50 Bq. People coming from the latter region had significantly higher body burdens as compared to those from the former, in accordance with the higher degree of ground radiocesium contamination reported for the latter region. Women and children showed considerably lower total radiocesium content in comparison to men. All radiocesium body burdens at the time of measurement were too low to be of health concern.

Adolescent↗
PubMed1992

Transmission of HIV by transfusion of HIV-screened blood: the value of a national register. The 'Recipients' Study Group of the French Society of Blood Transfusion.

A National Register of transfusion-transmitted infections was opened by the French Society of Blood Transfusion on 1 October, 1986. Out of 54 initially reported cases of HIV-infection, allegedly transmitted by blood components, further investigation could be completed in 33 cases. The transfusional origin of contamination was considered as established or probable in 28/33 cases, either because a potentially infectious unit was identified among those transfused to the recipient (23/28), or because the recipient was known to be seronegative before transfusion (5/28), or both (10/28). In 5/33 cases transfusion was considered as presumably responsible for contamination because no other risk factor was found in the recipient. Among the 33 documented cases of HIV-transmission by screened blood, 29 (88%) occurred between 1985 and 1987, and four (12%) during 1988. Out of 19 implicated donors later found seropositive, 16 belonged to a high-risk group for HIV-infection. The majority of HIV-infections occurred as a consequence of blood donation in the window period between contamination and the appearance of detectable antibodies in the donor's serum (11/19). In three instances, however, human and operational errors led to the release of seropositive units. We conclude that the main value of this Register is to provide a potential trend-indicator of transfusion-related infectious risks, to allow objective documentation of reported cases and to contribute to the improvement of blood transfusion practice.

AIDS Serodiagnosis↗
PubMed1992

Interstitial deletion of the proximal region of the long arm of chromosome 18, del(18q12) a distinct clinical entity? A report of two new cases.

Two unrelated mentally retarded patients were found to have an interstitial deletion of 18q12. They were a 2-year-old, short, macrocephalic and autistic girl, and a 5-year-old boy. Six other liveborn patients with comparable deletion have been so far identified. The common findings are mild dysmorphic features (telecanthus, epicanthal folds, flaring eyebrows, small mouth with thin upper lip), hypotonia, behavioural disorders, mental retardation with speech delay and lack of major malformation.

Child, Preschool↗
PubMed1991

The BRMD BOMAB phantom family.

The Human Monitoring Laboratory (HML) has used the International Commission on Radiological Protection's Report on Reference Man and Canadian anthropomorphic data as guidance to design and construct a family of phantoms corresponding to Reference Man (PM), Reference Woman (PF), Reference Ten-Year-Old (P10), Reference Four-Year-Old (P4), Ninety-five Percentile Man (PM95), and Five Percentile Man (PM5). The PM series also has an accessory chest section (PMacc) to better simulate lung depositions. The phantoms are constructed from high-density polyethylene and fitted with end-recessed filling caps to minimize leakage problems. This paper describes the methodology of construction and presents data so that the phantoms can be reproduced. The phantoms have been used in Canada's National in-vivo Intercomparison Program, and results show that all Canadian in-vivo counting facilities have size-dependent calibrations. Selected data are presented to exemplify this dependence.

Adult↗
PubMed1991

Antibody to hepatitis C (anti C 100-3) in French hemophiliacs.

486 patients followed in four French hemophilia centres were tested for antibody to hepatitis C virus C100-3 recombinant protein. On samples collected in 1989, the overall incidence of anti-C 100-3 positivity was 66%. None of the 27 patients only exposed to solvent-detergent treated factor VIII or IX concentrates had C 100-3 antibodies. There was no difference according to the type of hemophilia nor to its severity. Serological follow-up from 1985 to 1989 was carried out on 51 patients. Two third of the C-100 3 paradoxically seronegative patients in 1989 were in fact positive for these antibodies within the last 5 years. They have lost their HCV antibodies as seen with the presently available C 100-3 test. Actually, as the virus has been already present at least for the last 10 years, (on 51 samples collected in 1979, the incidence of C-100-3 positivity was 78%), all treated patients may well have been in contact with HCV.

Adolescent↗
PubMed1989

The glomerular basement membrane defect in Alport-type hereditary nephritis: absence of cationic antigenic components.

Alport-type hereditary nephritis is a familial disorder which results in progressive renal insufficiency and sensorineural hearing loss. It is thought to result from a biochemical defect affecting basement membranes. To study this further, non-collagenous components of type IV collagen were prepared from the glomerular basement membrane (GBM) by collagenase digestion from three male patients with hereditary nephritis. The normal Goodpasture antigenicity of the 28 and 26 kD monomers and 54 and 50 kD dimers which may be isolated from the GBM was absent on one-dimensional immunoblots. Two-dimensional electrophoresis and immunoblotting studies showed absence of Goodpasture antigenicity of these molecular weight components as well as all cationic monomeric and dimeric spots. It is concluded that the expression of the Goodpasture antigen is altered in basement membranes of hereditary nephritis patients. The altered antigenicity thus acts as a marker for the underlying abnormality.

Anti-Glomerular Basement Membrane Disease↗