Biomedical subjects

J Morel

Publications and source records attributed to J Morel.

At least 19 recordsLinked to original sources

PubMed2006

[HELLP syndrome and ruptured subcapsular hepatic haematoma. Case report and therapeutic options].

We report a case of spontaneous hepatic rupture secondary to HELLP syndrome. A favourable evolution was observed after massive transfusion and surgical management limited to hepatic packing. Subcapsular hepatic haematoma is a rare complication of preeclampsia occurring mainly in the context of HELLP syndrome. A high maternal and foetal mortality is observed. Different therapeutic options are presented including medical, surgical and radiological interventions. A unique strategy cannot be defined. Multidisciplinary approach seems mandatory. Surgery should remain as less aggressive as possible.

Adult↗

PubMed2005

How to predict prognosis in early rheumatoid arthritis.

In early rheumatoid arthritis (RA), the objectives of therapeutic strategies are to obtain remission and prevent joint destruction as early as possible. These goals may be reached with conventional disease-modifying antirheumatic drugs (DMARDs) or with biological agents. In clinical practice, initial treatments are usually chosen according to the degree of disease activity at baseline, and adapted according to a step-up strategy. A more elegant therapeutic approach would be to choose the most appropriate treatment based on the prognosis of RA. Therefore, prognostic stratification could improve the relative roles and benefits of initial DMARD or biological therapy for early RA. For RA with a severe prognosis, a combination of DMARDs or biologicals could be initiated as the first-line therapy. However, we need to know how to predict outcome in early RA for this type of strategy. This review attempts to answer this question by reporting the most reliable prognostic factors and some predictive models proposed for classification into benign, mild and severe RA.

Arthritis, Rheumatoid↗

PubMed2004

[Mediastinal and abdominal lymphoedema: consequence of massive pulmonary embolism with shock?].

We report a case of severe pulmonary embolism diagnosed using spiral CT-scan in a patient admitted for shock associated with acute abdominal symptoms. Intraluminal clots images were visualized associated with an infiltration of mediastinal fat. Abdominal CT showed infiltration of the hepatobiliary hilum. After thrombolysis, the clinical thoracic and abdominal symptoms improved. A CT-scan at the 48(th) hour showed that the thoracic and abdominal features had disappeared. We emphasize the misleading aspect of the CT-scan images and we speculated that this infiltration could reflect the abdominal and mediastinal lymphoedema.

Abdomen↗

PubMed2004

HLA-DMA0103 and HLA-DMB0104 alleles as novel prognostic factors in rheumatoid arthritis.

OBJECTIVE: To evaluate HLA-DM alleles as markers for disease severity in rheumatoid arthritis (RA). METHODS: Two distinct cohorts of patients with RA were oligotyped for HLA-DB1 and HLA-DM genes using PCR amplified genomic DNA with sequence specific oligonucleotide probes. Cohort 1 comprised 199 unselected patients with RA (mean (SD) age 45.5 (13.5) years; disease duration 11.9(8.8) years), whose disease severity was assessed using Larsen score on hand and foot radiographs. Cohort 2 comprised 95 patients with severe RA and 70 patients with benign RA according to the Larsen method. RESULTS: In cohort 1, after stratification according to DRB1 genotypes, patients positive for HLA-DMA*0103 and negative for HLA-DRB1*04 tended to have greater articular damage on hands and wrists (p = 0.07 by Mann-Whitney U test) and reached statistical significance for the Larsen score per year (p = 0.05). This association between HLA-DMA*0103 and articular damage was especially observed in patients with HLA-DRB1*01. Similarly, HLA-DMB*0104 positive patients had higher Larsen score on hands and wrists (p = 0.02). This association was even stronger in DRB1*04 positive patients (p = 0.005). In cohort 2, HLA-DMA*0103 was associated with severe RA in patients negative for HLA-DRB1*04 (OD = 5.4; p = 0.014). HLA-DMB*0104 allele frequency tended to be higher in patients with severe RA but without reaching significance. CONCLUSION: This is the first study evaluating the role of HLA-DM genes in the severity of RA. Our results suggest that HLA-DMA*0103 and HLA-DMB*0104 alleles may represent new genetic markers of RA severity. The HLA-DMA*0103 allele tends to be associated with patients with RA negative for DRB1*04 and could predict a more severe form of disease especially in HLA-DRB1*01 positive patients. The HLA-DMB*0104 allele could have an additive effect in HLA-DRB1*04 patients. Combined determination of HLA-DM and HLA-DRB1 alleles could facilitate identification of patients likely to have a poor disease course.

Adolescent↗

PubMed2003

[Iodine intoxication after subcutaneous irrigations of povidone iodine].

Irrigation of povidone iodine considered as a safe and effective procedure, is frequently used for deep infections. We report a case of intoxication by iodine in a man of 68-year-old after subcutaneous irrigations of Betadine at a concentration of 20% for a subcutaneous infection of the thigh. Abnormalities of cardiac conduction, lactic acidosis, acute renal failure, hypocalcaemia and thyroid dysfunction were the manifestations of the intoxication confirmed by a very high level of total blood iodine and urine iodine.

Aged↗

PubMed2001

Steady-state kinetics of MgATP splitting by native myosin RLC-free subfragment 1.

MgATP positively regulates the dimerisation reaction, resulting in an increase in the rate of MgATP splitting with increasing MgATP concentration. We investigated the stoichiometry of this dimerisation reaction and found that each subunit in the dimer bound one molecule of MgATP at the dimerisation site. We studied changes with temperature in the MgATPase activity of S1 in the dimeric form for temperatures of 18-25 degrees C. Between 18.0 and 21.2 degrees C, kcat increased steadily with temperature. Between 21.2 and 21.8 degrees C, there was a large decrease in kcat. A strong increase in kcat occurred at temperatures above 21.8 degrees C, corresponding to a new reversible conformation of S1, unable to dimerise. The steep decrease in kcat between 21.2 and 21.8 degrees C is due to a temperature transition in the monomer-dimer equilibrium.

Adenosine Triphosphate↗

PubMed2001

Bone mineral density of 704 amateur sportsmen involved in different physical activities.

The aim of the study was to analyze the relation between sports and bone mass. Seven hundred and four men with no history of chronic disease were questioned on their adolescent and adult sporting activities. Their total body (TB) and regional (head, spine, arms and legs) bone mineral density (BMD) were measured by dual-energy X-ray absorptiometry. BMD measurements and ratios of regional BMD to TB BMD were compared using a multiple regression analysis. Probands (mean age 30 years) were engaged in 14 sports activities: rugby, soccer, other team sports, endurance running, fighting sports, bodybuilding, multiple weightbearing activities, swimming, swimming with flippers, biking, rowing, climbing, triathlon and multiple mixed activities. They stated that they were practising a physical activity at the amateur level: 7.1 h/week between the ages of 11 and 18 years and 9 h/week between age 18 years and the day of the interview (no significant difference between physical activities). Rowers and swimmers had low TB BMD (1.22 and 1.17 g/cm2) and low leg BMD (1.37 and 1.31 g/cm2). Participants in rugby, soccer, other team sports and fighting sports had a high TB BMD (1.27-1.35 g/cm2) and high leg BMD (1.41-1.5 g/cm2). For head BMD, there was no stastistical difference among the different groups. Constructed ratios pointed out the site-specific adaptation of the skeleton: soccer player and runners had a higher leg ratio; bodybuilders, fighters, climbers and swimmers had a higher arm ratio; rugby players had a higher spine ratio. Head ratio was higher in non-weightbearing sports (rowing, swimming) than in weightbearing sports (rugby, team sports, soccer, fighting sports and bodybuilding). Thus the BMD and ratio differences among the 14 disciplines seem to be site-specific and related to the supposedly high and unusual strains created at certain sites during sport training by muscle stress and gravitational forces. Head ratio is closely related to the type of practice; its value could predict whether sport participants have developed the maximal peak bone mass they could achieve.

Absorptiometry, Photon↗

PubMed2001

Effect of pH on the sorption of uranium in soils.

This work was undertaken to study the influence of soil type and chemical composition on uranium sorption ratios (SR in 1 kg-1) in order to reduce the uncertainty associated with this parameter in risk assessment models. Thirteen soil samples were collected from three different locations in France under different geological conditions. Clay content varied from 7.0 to 50.0%, pH ranged from 5.5 to 8.8 and organic matter content from 1.0 to 4.6%. Soils were incubated at room temperature in polyethylene packets for 28 days in the presence of 1 mg U kg-1 soil. Sorption ratio values varied from 0.9 to 3198 for all soils with no significant effect of soil texture or of organic matter. However, soil pH was highly linearly correlated with (log SR) as a probable consequence of the existence of different uranium complexes as a function of soil pH. The sorption behaviour differences between UO2(2+) and UO2(2+)-carbonate complexes are so great that any other effect of soil properties on U sorption is hidden. Thus, soil pH should be the focus variable for reduction of the uncertainty associated with the soil Kd value used in environmental risk assessments, even for reducing the uncertainty in site-specific Kd values.

Hydrogen-Ion Concentration↗

PubMed2001

[Cerebrovascular accident: differential diagnosis of a compressive spinal hematoma].

We report the case of a 84-year-old patient who developed a monoplegia of the left inferior limb after a spinal anaesthesia for femoral neck's fracture. The magnetic resonance imaging (MRI) carried out in emergency, eliminated a spinal compression. The final diagnosis was a cerebral stroke. This observation leads us to discuss the choice of anaesthesia technical, the various aetiologies of a neurological trouble after spinal anaesthesia. The appearance of clinical signs evoking a spinal haematoma, must make seek by the imagery (MRI or scanner) the signs of spinal compression in order to propose an emergency laminectomy. Finally we insist on the importance but also on the difficulties of the clinical examination in elderly traumatic patients.

Aged↗

PubMed2000

The down-regulation of HLA-DM gene expression in rheumatoid arthritis is not related to their promoter polymorphism.

HLA-DM molecule, a class II-like heterodimer, is a critical factor of HLA class II-dependent Ag presentation. It acts as a molecular chaperone and also functions as a peptide editor favoring the presentation of high-stability peptides. Thus, it appears to skew the peptide repertoire presented to T cells. Variation in HLA-DM expression has considerable effect on Ag presentation and regulation of these genes is likely to be a prerequisite to prevent autoimmunity. In this study, rheumatoid arthritis (RA) was chosen as a model of human autoimmune disease since its genetic susceptibility is known to be associated with the HLA-DR and -DM components. We described a limited nucleotide polymorphism in the HLA-DM promoters with functional impact on basal transcriptional activity and IFN-gamma induction as assessed in vitro. However, no difference of allele frequencies was found between controls and RA patients. Despite of this lack of association, expression of HLA-DM molecules was also investigated. Interestingly, an underexpression of HLA-DM transcripts and protein was shown in peripheral blood B cells from RA patients compared with controls or inflammatory arthritis patients. This underexpression does not affect HLA-DR genes and is responsible for a decrease of the DM:DR ratio in RA patients. This specific HLA-DM down-regulation is likely to have important consequences on Ag presentation and could participate in the autoimmune process in RA.

Arthritis, Rheumatoid↗

PubMed2000

Prevalence of anemia among James Bay Cree infants of northern Quebec.

BACKGROUND: Anemia is common among First Nation infants in Canada, often as a result of iron deficiency, which places them at risk for psychomotor impairment. Prevalence data are unavailable, and the risk factors are unknown. This study assessed the prevalence of anemia and associated risk factors among 9-month-old Cree infants in northern Quebec. METHODS: Between January 1995 and October 1998, 6 of 9 Cree villages in the James Bay region adopted a screening protocol for anemia in 9-month-old infants. Cross-sectional data were obtained from medical charts. The data for babies of very low birth weight and those with fever or infection were excluded. Among the 386 babies whose hemoglobin concentration was known, the type of milk consumed at the time of screening was known for 354. Associations between hemoglobin concentration and mean cell volume at 9 months, and milk type and weight gain since birth were analysed. RESULTS: The mean hemoglobin concentration of the 386 infants was 114.1 (standard deviation [SD] 10.6) g/L. The prevalence of anemia was 31.9% (95% confidence interval [CI] 27.2%-36.7%) with a hemoglobin cutoff value of 110 g/L, 17.6% 95% CI 13.9%-21.7%) with a cutoff value of 105 g/L, and 7.8% (95% CI 5.3%-10.9%) with a cutoff value of 100 g/L. Babies exclusively fed formula at 9 months had a higher mean hemoglobin concentration (118.5 [SD 9.9] g/L) than those exclusively fed breast milk (109.9 [SD 10.0] g/L), cow's milk (112.5 [SD 10.1] g/L) or more than one type of milk (112.0 [SD 10.8] g/L) (p < 0.05). Compared with formula, the odds ratio (OR) for anemia was 7.9 (95% CI 3.4-18.2) for breast milk, 5.0 (95% CI 2.0-12.7) for cow's milk and 5.2 (95% CI 1.9-14.6) for mixed milks. Infants fed formula and those fed cow's milk had significantly greater weight gains since birth, by 724 g and 624 g respectively, than breast-fed infants (p < 0.05). When milk type was controlled for, weight gain since birth was significantly associated with the presence of microcytic erythrocytes (OR comparing highest tertile of weight gain to lowest tertile 2.9, 95% CI 1.2-6.6). INTERPRETATION: Iron-deficiency anemia is highly prevalent among James Bay Cree infants. Measures to increase iron intake are required.

Analysis of Variance↗

PubMed2000

Results from the EUROMET action 410 concerning the decay data of 169Yb

An international comparison EUROMET, action No. 410, was organized with the objective of improving the knowledge of nuclear data for 169Yb decay. To determine the photon emission probabilities, the participants were asked to measure at least one of the quantities, activity per unit mass and/or photon emission rate per unit mass. In addition, the participants were requested to report the count rates observed with point source samples for an eventual coaxial-type germanium detector characterization. Eleven laboratories participated, giving one or more sets of results. In all, 34 sets of results were received, 17 for the activity measurement, 11 for the photon emission rate measurement and six for the detector characterization. Using the accurate activity value obtained from this exercise, it was possible to determine the emission probabilities of the main X- and gamma-rays with an uncertainty of 1-2% for the LX-rays, 1% for the KX-rays and < or =0.5% for the main gamma-rays. These data can be very useful for the calibration of so-called gamma-X ray detectors'. The measurement of 169Yb with type P or N coaxial structure detectors has also made possible an estimation of their diameters and volumes.

Journal Article↗

PubMed2000

Emission probabilities of the main gamma-rays of 237Np in equilibrium with 233Pa

Due to the needs in environment monitoring and nuclear waste survey, there has been increasing interest over recent years for measuring the activity of 237Np. Thus, the EUROMET project No. 416 has been proposed by NPL, in order to improve as well as possible the knowledge of the decay scheme of this radionuclide. In order to achieve this objective, the emission probabilities of the main gamma-rays following the decay of 237Np in equilibrium with its daughter 233Pa, have been precisely measured, using calibrated Ge-HP detectors and sources for which the activity has been determined from absolute measurement. The obtained results, the main instrumentation characteristics, details of the experimental procedure, are presented and discussed in this paper.

Journal Article↗

PubMed2000

Results from the international evaluation exercise for uranium enrichment measurements. European Safeguards Research and Development Association NDA-WG Members

An international evaluation exercise for uranium enrichment measurement was organized by the ESARDA (European Safeguards Research and Development Association) Working Group on Techniques and Standards for Non-Destructive Analysis. The aim of this exercise was to test the different methods and more particularly X- and gamma-ray spectrometry methods used in the determination of uranium enrichment. Sets of samples of different uranium enrichments prepared by IRMM (Institute for Reference Materials and Measurements) and BNFL (British Nuclear Fuels) were measured by 15 participants in the IRMM laboratories. A description of this exercise is given here and the final results with their uncertainties are compared to the reference values obtained from mass spectrometry measurements. The main conclusions from this exercise are proposed; in particular, it appears necessary to improve the nuclear data used in the spectral modeling of the XKalpha region.

Journal Article↗

PubMed2000

Outcomes in patients with incipient undifferentiated arthritis.

OBJECTIVE: To determine outcomes in patients with onset within the last year of peripheral inflammatory arthritis that does not meet classification criteria for any specific disease. METHODS: Symptoms and laboratory tests were evaluated at baseline and 14 to 60 months later in 43 patients, 32 women and 11 men, with a mean age of 50 years. RESULTS: At baseline, a presumptive clinical diagnosis was made in 16 of the 43 patients. Diagnoses at last follow-up were undifferentiated inflammatory arthritis in seven cases, mild rheumatoid arthritis in 18, psoriatic arthritis in two, Sjögren's syndrome in two, lupus in one, and paraneoplastic syndrome in one. The remaining 12 patients were free of inflammatory joint symptoms; three had symptoms of osteoarthritis and nine were asymptomatic. Factors present at baseline and predictive of progression to definite rheumatoid arthritis were a positive test for rheumatoid factor, presence of an HLA DRB1*04 allele, and a presumptive clinical diagnosis of rheumatoid arthritis. CONCLUSION: 55% of our patients developed a specific inflammatory joint disease, and 42% developed rheumatoid arthritis, which was consistently mild. Resolution of all inflammatory joint symptoms occurred in 28% of cases. A number of clinical laboratory, and genetic findings of use for predicting the outcome of undifferentiated arthritis were identified.

Adult↗

PubMed2000

Folic acid alters methotrexate availability in patients with rheumatoid arthritis.

OBJECTIVE: To evaluate the effects of repeated doses of folic acid on the pharmacokinetics of methotrexate (MTX) in patients with rheumatoid arthritis. METHODS: We studied 20 patients (ages 30-78 years) who received MTX intramuscularly (10 mm/week). MTX was administered alone or after treatment with folic acid (5 mg tablet once daily) for 13 days. Plasma samples were collected 2 and 8 h after dose intake. MTX concentrations in plasma and ultrafiltrate samples were measured by fluorescence polarization immunoassay. A Bayesian approach was used to determine individual MTX pharmacokinetic variables to minimize the number of samples collected. RESULTS: Folic acid supplementation led to reduced plasma MTX levels 2 and 8 h after MTX administration and reduced area under the plasma MTX concentration versus time curve (AUC) (about 20%; p < 0.02). Total clearance of MTX and Vd were higher when patients were also receiving folic acid than when they were taking MTX alone (p < 0.02). The plasma protein binding of MTX remains unchanged. CONCLUSION: The lower plasma MTX concentrations in patients taking folic acid supplements could be interpreted as increased cellular uptake of MTX; the folic acid supplements would promote the sequestering of MTX intracellularly. The decrease of MTX concentrations leads to reduced AUC; it is also possible that there are reduced AUC combined with increased intracellular folate levels. These results reopen the question of whether folic acid should be used immediately in all patients when MTX is begun.

Adult↗

PubMed1999

Myosin thick filaments from adult rabbit skeletal muscles.

Myosin subfragment 1 (S1) forms dimers in the presence of Mg(2+) or MgADP or MgATP. The entire myosin molecule forms head-head dimers in the presence of MgATP. The angle between the two subunits in the S1 dimer is 95 degrees. Assuming that the length of the globular part of S1 is approximately 12 nm and that the S1/S2 joint (lever arm approximately 7 nm) is clearly bent, the cylinder tangent to this dimer should have a diameter of approximately 18 nm, close to the approximately 16-20 nm suggested by many studies for the diameter of thick filaments in situ. These conclusions led us to re-examine our previous model, according to which two heads from two opposite myosin molecules are inserted into the filament core and interact as dimers. We studied synthetic filaments by electron microscopy, enzyme activity assays, controlled digestion and filament-filament interaction analysis. Synthetic filaments formed by rapid dilution in the presence of 1 mM EDTA at room temperature ( approximately 22 degrees C) had all their myosin heads outside the backbone. These filaments are called superfilaments (SF). Synthetic filaments formed by slow dilution, in the presence of either 2 mM Mg(2+) or 0.5 mM MgATP and at low temperature ( approximately 0 degrees C) had one myosin head outside the backbone and one head inside. These filaments are called filaments (F). Synthetic filaments formed by slow dilution, in the presence of 4 mM MgATP at low temperature ( approximately 0 degrees C) had most of their heads inserted in the filament core. These filaments are called antifilaments (AF). These experimental results provide important new information about myosin synthetic filaments. In particular, we found that myosin heads were involved in filament assembly and that filament-filament interactions can occur via the external heads. Native filaments (NF) from rabbit psoas muscle were also studied by enzyme assays. Their structure depended on the age of the rabbit. NF from 4-month-old rabbits were three-stranded, i.e. six myosin heads per crown, two of which were inside the core and four outside. NF from 18-month-old rabbits were two-stranded (similar to F).

Adenosine Triphosphate↗

PubMed1999

Comparison of the fuel oil biodegradation potential of hydrocarbon-assimilating microorganisms isolated from a temperate agricultural soil.

Strains of hydrocarbon-degrading microorganisms (bacteria and fungi) were isolated from an agricultural soil in France. In a field, a portion was treated with oily cuttings resulting from the drilling of an onshore well. The cuttings which were spread at the rate of 600 g HC m-2 contained 10% of fuel oil hydrocarbons (HC). Another part of the field was left untreated. Three months after HC spreading, HC adapted bacteria and fungi were isolated at different soil depths in the two plots and identified. The biodegradation potential of the isolated strains was monitored by measuring the degradation rate of total HC, saturated hydrocarbons, aromatic hydrocarbons and resins of the fuel. Bacteria of the genera Pseudomonas, Brevundimonas Sphingomonas, Acinetobacter, Rhodococcus, Arthrobacter, Corynebacterium and fungi belonging to Aspergillus, Penicillium, Beauveria, Acremonium, Cladosporium, Fusarium, and Trichoderma were identified. The most active strains in the assimilation of saturates and aromatics were Arthrobacter sp., Sphingomonas spiritivorum, Acinetobacter baumanii, Beauveria alba and Penicillum simplicissimum. The biodegradation potential of the hydrocarbon utilizing microorganisms isolated from polluted or unpolluted soils were similar. In laboratory pure cultures, saturated HC were more degraded than aromatic HC, whereas resins were resistant to microbial attack. On an average, individual bacterial strains were more active than fungi in HC biodegradation.

Bacteria↗