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Biomedical subjects

L Noël

Publications and source records attributed to L Noël.

At least 19 recordsLinked to original sources
PubMed2004

Subchronic dietary exposure of rats to cadmium alters the metabolism of metals essential to bone health.

Cadmium (Cd) was recently identified as a risk factor for osteoporosis. Skeletal damage may be the critical effect of low-level long-term exposure to Cd in the general population exposed via food, but the mechanisms behind this are not clearly understood. We investigated the effect of dietary Cd exposure on metals involved in bone turnover. Female rats received a Cd-supplemented diet (0, 10, 50, or 200 CdCl2 mg/kg diet) for 13 weeks. Cd and essential metals stored in the liver were measured by ICP-MS multianalysis. Mineral content of the livers was modified according to Cd level: iron, magnesium and selenium decreased while copper, zinc and manganese increased with increasing Cd levels. Iron was the most strikingly affected metal, falling to one-fifth of control values at high dietary Cd exposure. In this dosage group, selenium decreased to 36% of mean control concentrations while zinc increased to 168%. This mineral imbalance, especially depleted iron stores, can contribute, at least in part, to the Cd-associated risk of osteoporosis. The association between iron metabolism and Cd exposure should be investigated in humans, as Cd and low iron stores could act synergistically as risk factors for osteoporosis.

Animals↗
PubMed2003

Determination of several elements in duplicate meals from catering establishments using closed vessel microwave digestion with inductively coupled plasma mass spectrometry detection: estimation of daily dietary intake.

An estimation of the dietary exposure of French consumers to 21 essential and non-essential mineral elements using duplicate meals (breakfast and lunch) purchased from catering establishments was investigated after digestion by a closed vessel microwave procedure and quantification by ICP-MS. Daily dietary exposure estimates for metals and minerals were compared with the Provisional Tolerable Weekly Intakes (PTWI), the Tolerable Daily Intake (TDI) or the Acceptable Daily Intakes (ADI), as established by the FAO/WHO to estimate the risk of toxicity, and the US Recommended Daily Allowances (US RDA) or the Estimate Safe & Adequate Daily Dietary Intakes (ESADDI). Moreover, comparisons were made with those from previous French studies as well as those from other countries. The estimated mean daily intakes were 11 microgram for lithium, 3.42 g for sodium, 192 mg for magnesium, 2.03 mg for aluminium, 3.64 g for potassium, 642 mg for calcium, 154 microgram for chromium, 12.3 mg for iron, 2.15 mg for manganese, 4 microgram for cobalt, 74 microgram for nickel, 925 microgram for copper, 10.2 mg for zinc, 147 microgram for arsenic, 66 microgram for selenium, 112 microgram for molybdenum, 3.6 microgram for cadmium, 2.32 mg for tin, 3 microgram for antimony, 9 microgram for mercury and 34 microgram for lead. For the non-essential (toxic) elements, aluminium, tin, antimony, cadmium, arsenic, mercury and lead, the daily intake estimates were far below tolerable limits; and similar or somewhat lower than their respective PTWI, ADI, TDI, ESADDI and US RDA for individual minerals and essential trace elements, with good agreement with other country studies. The performance of the multi-elemental ICP-MS technique was also evaluated.

Diet↗
PubMed2002

[Intracerebral radiation-induced cavernous angiomas].

We present four cases of cerebral cavernous angioma that developed after radiatherapy for brain tumor in three cases and for cavernous angioma in one case. The time interval between irradiation and the detection of the cavernous angioma varied from three to nine years and the doses from 24 to 60 Grays. Brain hemorrhage appeared in two cases. Explanation for the formation of cavernous malformations is unclear but is probably related to proliferation and dilatation of the vascular endothelium with formation of capillary telangiectasis with evolution to cavernous angiomas. The pediatric brain appears particularly vulnerable to radiation injury. The risk of hemorrhage appears higher than with spontaneous cavernous malformations.

Adolescent↗
PubMed2001

cDNA-AFLP analysis unravels a genome-wide hrpG-regulon in the plant pathogen Xanthomonas campestris pv. vesicatoria.

The Hrp type III protein secretion system is essential for pathogenicity of the Gram-negative plant pathogen Xanthomonas campestris pv. vesicatoria. Expression of the hrp gene cluster is controlled by HrpG, a two-component response regulator, and HrpX, an AraC-type transcriptional activator. Using the cDNA-AFLP technique, 30 hrpG-induced (hgi) and five hrpG-repressed (hgr) cDNA fragments were identified, defining a large hrpG-regulon in X. campestris pv. vesicatoria. Expression of most genes in the hrpG-regulon was dependent on hrpX. Seven cDNA fragments map to the known hrp gene cluster and flanking regions. All other genes appear to be scattered over the chromosome and endogenous plasmids. Sequence analysis identified genes encoding putative extracellular proteases, a putative transcriptional regulator and XopJ and XopB (Xanthomonas outer proteins), homologues of YopJ from Yersinia spp. and the avirulence protein AvrPphD of Pseudomonas syringae respectively. XopB is secreted by the Hrp type III secretion system. Analysis of deletion mutants in several hgi genes revealed a new virulence locus. This study demonstrates that cDNA-AFLP is a powerful tool to study prokaryotic transcriptomes and to identify genes contributing to Xanthomonas virulence and putative effector proteins.

Bacterial Proteins↗
PubMed2001

Correctional officers' intention of accepting or refusing to make HIV preventive tools accessible to inmates.

The aim of this study was to identify the factors which explain correctional officers' intention of accepting or refusing to make HIV preventive tools (condoms, bleach, tattooing equipment, and syringes) accessible to inmates. A total of 957 officers completed a questionnaire that took into account determinants from several social-cognitive behavior theories. The results indicated that only 21.4% of officers were favorable toward making accessible all of the preventive tools. The theoretical model explained 87% of the intention variance, p < .0001. Self-efficacy (beta = .35), personal normative belief (beta = .29), social determinants (beta = .21) and the affective dimension of attitude (beta = .19) were significant determinants. Moreover, officers with a high level of intention differed from those with a low level of intention on several points of the theoretical model. In conclusion, the results clearly indicated that several difficulties must be overcome before HIV preventive tools as a whole can be made accessible to inmates.

Adult↗
PubMed2001

[Multiple gastrointestinal tract duplication : a neonatal case report].

We report the case of newborn with multiple GI tract duplication cysts. Prenatal diagnosis was that of duodenal stenosis. A complete screening for polymalformative syndrome is required in the neonatal period and the authors insist on the importance of US and color Doppler US imaging.

Abnormalities, Multiple↗
PubMed2001

Correctional officers and prevention of HIV transmission among prisoners.

The problem of HIV transmission in prisons in Québec and elsewhere is increasingly urgent and requires the attention of federal and provincial authorities. Prison officers are among the key players who should be kept in mind when preventive measures are being developed. We reprint the executive summary of a study conducted in federal and provincial prisons in Québec. The goal of the study was to identify the factors influencing prison officers, with respect to whether they would agree or refuse to make accessible the tools needed for the prevention of HIV transmission among inmates (i.e., condoms, bleach, tattooing equipment, and needles). Among the factors studied are officers' perceptions and beliefs as well as their attitudes, perceived social norms, emotions, and perceived barriers with respect to making preventive tools accessible.

HIV Infections↗
PubMed1999

Pronounced intraspecific haplotype divergence at the RPP5 complex disease resistance locus of Arabidopsis.

In Arabidopsis ecotype Landsberg erecta (Ler), RPP5 confers resistance to the pathogen Peronospora parasitica. RPP5 is part of a clustered multigene family encoding nucleotide binding-leucine-rich repeat (LRR) proteins. We compared 95 kb of DNA sequence carrying the Ler RPP5 haplotype with the corresponding 90 kb of Arabidopsis ecotype Columbia (Col-0). Relative to the remainder of the genome, the Ler and Col-0 RPP5 haplotypes exhibit remarkable intraspecific polymorphism. The RPP5 gene family probably evolved by extensive recombination between LRRs from an RPP5-like progenitor that carried only eight LRRs. Most members have variable LRR configurations and encode different numbers of LRRs. Although many members carry retroelement insertions or frameshift mutations, codon usage analysis suggests that regions of the genes have been subject to purifying or diversifying selection, indicating that these genes were, or are, functional. The RPP5 haplotypes thus carry dynamic gene clusters with the potential to adapt rapidly to novel pathogen variants by gene duplication and modification of recognition capacity. We propose that the extremely high level of polymorphism at this complex resistance locus is maintained by frequency-dependent selection.

Amino Acid Sequence↗
PubMed1998

[Transfusion incidents related to bacterial contamination: review of the literature and hemovigilance data. For the working group Bacterial incidents of French Blood Agency, scientific advice of Bacthem and the French hemovigilance network].

The impact of transfusion reactions related to bacterial contamination (TRBC) of labile blood products (LBP) was identified in France soon after the implementation of the haemovigilance system. The aims of our communication were: 1) to confront published data on TRBC with available French data; 2) to describe measures implemented in France to prevent TRBC. Bacterial contamination of whole blood at the collection stage is found in 0.6 to 3% of blood donations. Systematic bacteriological controls detect frequent contaminations of LBP that vary according to studies and the nature of the product. The incidence of clinical TRBC was only estimated in recipients with malignant diseases. Based on French haemovigilance data, the incidence was estimated to two per 100,000 delivered units. The measures taken were the diffusion of information and recommendations and the implementation of studies. In the framework of the Bacthem study (a national case-control study on LBP-related bacterial contamination), standardised diagnostic criteria are applied to suspected TRBC notified to the Centre National d'Hémovigilance. Expected results should allow us to estimate the incidence of TRBC in France and to determine the recipients or situations at risk more precisely, in order to target additional preventive measures. Preliminary results, 11 months after the beginning of the study, show the feasibility and the relevance of completing the surveillance with specific studies within the haemovigilance network.

Bacterial Infections↗
PubMed1996

[Quality assurance of bacterial incidents associated with blood transfusion].

Transfusion associated bacterial sepsis, TABS, may be caused by-donor bacteremia,-bacteria from the donors skin,-bacteria brought by one of the persons handling the donation or the blood product, from collection and components preparation to the actual transfusion,-or bacteria introduced by a defect in one of the disposables used. Quality Assurance relies on the Good Transfusion Practices of the French Blood Agency all along the transfusion chain from the donor to the recipient. Active involvement of personnel, standardisation and controls as well as improvement of technics particularly as regarding donor selection, skin disinfection technics and collection are required. The ultimate control is hemovigilance with proper identification and investigation of all cases of TABS even with mild symptoms. Centralisation of data in the Haemovigilance scheme is a further step toward a better understanding and improvement of blood products bacterial security.

Bacteremia↗
PubMed1996

[Viral attenuation of labile blood products].

Viral inactivation is one of the possibilities to reduce the residual risk of blood products. It is now applied to all plasma derived products (PDP). Application of such techniques to labile blood products (LBP) is difficult for two main reasons: any method should inactivate cell-associated viruses and should avoid any injury of the cells constituting the active ingredient. Physical techniques may reduce the viral content of cellular BPL (leucodepletion, washing, gamma irradiation), but none of them is active enough to comply with the present requirements for efficacy. An important work has been dedicated to the development of virus photoinactivation techniques. They consist of the addition of a photoreagent followed by illumination at an appropriate wavelength which results in a photochemical reaction responsible for the viral inactivation. Treatment of platelet concentrates by psoralen derivatives and UV-A illumination significantly inactivate in vitro enveloped and naked viruses, free and cell-associated viruses and also sequences integrated in the viral genome. Recent progresses have led to these results without detectable functional alteration of platelets and mutagenicity. Viral inactivation of red blood cells yet did not reach the same level because hemoglobin does not allow the use of the photoreagent compounds applicable to platelet concentrates. Viral decontamination of fresh frozen plasma by solvent and detergent, active on enveloped viruses, has been used in France since 1992. Other techniques of comparable efficacy, have received an agreement in other countries. The research on viral inactivation of LBP could prove to be of great importance in the near future in bringing additional safety to patients not only for the residual viral risk but maybe also for the residual bacterial risk of LBP.

Antiviral Agents↗
PubMed1996

Prevalence and risk behaviours for HIV infection among inmates of a provincial prison in Quebec City.

OBJECTIVE: To assess HIV prevalence and related risk factors among inmates at the Quebec Detention Centre (QDC). DESIGN: Cross-sectional prevalence study. METHODS: Inmates incarcerated at the QDC in September 1994 were asked to participate in an anonymous survey concerning HIV infection. Volunteers answered a questionnaire and provided a saliva sample during a meeting with an interviewer. RESULTS: The overall participation rate was 95% (618 out of 651). HIV prevalence was 2% (11 out of 499) in men. All HIV-infected men were injecting drug users (IDU) with an HIV prevalence of 9% (11 out of 129) in this group. HIV prevalence was 14% (9/63) among male IDU admitting previous needle-sharing and 3% (two out of 66) among the other IDU (odds ratio, 5.3; P = 0.028). Twelve male inmates admitted injecting drugs during imprisonment, of whom 11 shared needles and three were HIV-positive. HIV prevalence in men reporting sexual intercourse with men prior to incarceration was 10% (five out of 52). Nine of the 119 women were HIV-infected (8%), seven of whom were IDU (prevalence of 16% in female IDU). One of the two non-IDU had sexual contacts with male IDU, and the other with men who had sex with men. Tattooing was not associated with HIV infection in either men or women. CONCLUSIONS: Prisoners constitute a group at high risk of HIV infection mainly because of the high proportion of them who are IDU. Imprisonment offers a good opportunity to provide education and preventive programs to this specific group that might otherwise be difficult to reach.

Female↗
PubMed1996

The BRMD thyroid-neck phantom: design and construction.

The Human Monitoring Laboratory, which acts as the Canadian National Calibration Reference Center for In Vivo monitoring, has constructed a robust neck-thyroid phantom for use in the Canadian Thyroid Intercomparison Program. The phantom is rugged and capable of being distributed through the mail with no expectation of a leak of radioactive materials; it is anthropomorphic; the thyroid inserts simulate 125I and 131I; the phantom can be used to mimic different layers of adipose tissue over the thyroid insert; and it is cost effective. This paper describes the design criteria and the manufacturing process; the performance characteristics have been described in an earlier publication.

Canada↗
PubMed1995

Properties of red blood cell concentrates stored in PAGGS-sorbitol.

The physiological, biochemical, morphological and rheological characteristics of RBC resuspended in PAGGS-Sorbitol were studied over, and beyond, 49 days. The levels of P50 and 2,3-DPG, as well as the concentration of ATP, stayed above acceptable values for longer periods than those described with other Optional Additive Solutions (OAS). Spontaneous hemolysis was kept below 1%, cell morphology, viscosity, deformability and other factors such as pH, the ratio of glucose consumption to lactate formation, the total adenylates and energetic charge indicate that good properties should be seen after 49 days' storage. In vivo survival studies using a double isotope technique showed that at least 75% of those RBC stored in this OAS for 49 days were still in circulation 24 hours after injection. Therefore RBC stored in PAGGS-S can be kept for 49 days with excellent in vivo survival, as well as maintaining DPG levels for up to 3 weeks. Furthermore, a clinical trial in routine conditions for use has been carried out with surgical and medical patients as well as with hemodialysed patients. The results obtained are those that could at least be expected of normal stored blood. As regards RBC/PAGGS-Sorbitol, it would be reasonable to propose a storage period of 49 days in the liquid state.

Adenine↗
PubMed1992

[Anti-HCV and recipients: situation in hemophiliacs in 1991].

Sera from 273 French haemophiliacs who had received non viral inactivated concentrates, were tested for antibodies to HCV by first and second generation assays. Antibodies to HCV were detected in 66% of the sera by the first generation assays (anti-C 100-3) reaching 100% by the second generation assays. None of the 53 patients only exposed to solvent-detergent treated Factor VIII or IX concentrates had HCV seroconversion. HCV core protein antibody was always detectable often as a single antibody in seropositive hemophilic patients.

Antigens, Viral↗