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Biomedical subjects

L Bernard

Publications and source records attributed to L Bernard.

At least 55 records · Page 3Linked to original sources
PubMed2000

A longitudinal insufficiency fracture of the tibia in association with a healed chronic osteomyelitis.

Longitudinal stress fracture of the tibia often present with an atypical clinical presentation which can be mistaken for osseous tumor or osteomyelitis. We present a case of longitudinal stress fracture of the tibia which occurred in a patient with healed chronic osteomyelitis of the tibia. Magnetic resonance imaging failed to make the correct diagnosis. Accurate diagnosis was only obtained by helical CT which showed the longitudinal fracture line. Magnetic resonance imaging showed only non-specific signs of bone marrow edema, suggesting recurrence of osteomyelitis. Magnetic resonance imaging can be misleading in the absence of direct visualization of the fracture line.

Adult↗
PubMed2000

SEL1L, the human homolog of C. elegans sel-1: refined physical mapping, gene structure and identification of polymorphic markers.

We have cloned the human full-length cDNA SEL1L, which is highly similar to the C. elegans sel-1 gene, an important negative regulator of the "notch" pathway which acts as a key regulator of the cellular proliferation and specification processes in both vertebrates and invertebrates. The SEL1L gene maps to 14q24.3-31 and here we report its fine localization by HAPPY mapping, which determines its molecular distance to microsatellite markers isolated in the region. We have found two new polymorphic (CA)n microsatellites located in the gene, and have identified the exon-intron boundaries. The gene is composed of 21 exons spanning 70 kb of genomic DNA. Human SEL1L protein exhibits a high degree of similarity compared to the mouse and nematode homologs.

Amino Acid Sequence↗
PubMed2000

Hepatitis C virus co-infection is a negative prognostic factor for clinical evolution in human immunodeficiency virus-positive patients.

A longitudinal study of human immunodeficiency virus (HIV)-infected individuals followed-up in 13 centres was performed to assess the influence of hepatitis C virus (HCV) on the clinical and immunological evolution of HIV-infected patients. Eight-hundred and twelve HIV-infected patients with known HIV acquisition date, 89 co-infected with HCV, were included in the cohort. Clinical progression was defined as: 30% decrease of Karnofsky's index; and/or 20% body weight loss; and/or acquired immune deficiency syndrome (AIDS)-defining illness; and/or death (except by accident, suicide, or overdose). Immunological progression was defined as a decrease of initial CD4 count to below 200 mm(-3). If immunological progression was not statistically different between groups (P=0.25), clinical progression was significantly faster in HCV-HIV co-infected patients in univariate (P=0.02) and multivariable survival analysis (hazard ratio=1.63, P=0.03). This argues for active management of hepatitis C chronic infection among HCV-HIV co-infected patients.

Adult↗
PubMed2000

Specific combinations of zein genes and genetic backgrounds influence the transcription of the heavy-chain zein genes in maize opaque-2 endosperms.

The transcript levels of heavy-chain zein genes (zH1 and zH2) and the occurrence of the zH polypeptides in different opaque-2 (o2) lines were investigated by RNA-blot analyses and by sodium dodecylsulfate-polyacrylamide gel electrophoresis or two-dimensional gel electrophoresis protein fractionations. Four mutant alleles o2R, o2T, o2It, and o2-676 introgressed into different genetic backgrounds (GBs) were considered. The mono-dimensional gel electrophoresis zein pattern can be either conserved or different among the various GBs carrying the same o2 allele. Likewise, in the identical GB carrying different o2 alleles, the zein pattern can be either conserved or differentially affected by the different mutant allele. Zein protein analysis of reciprocal crosses between lines with different o2 alleles or the same o2 showed in some case a more than additive zH pattern in respect to the o2 parent lines. Electrophoretic mobility shift assay approaches, with O2-binding oligonucleotide and endosperm extracts from the above o2 lines, failed to reveal o2-specific retarded band in any of the o2 extracts. The results suggest that the promoter of some zH1 and zH2 contains motif(s) that can respond to factors other than O2.

Alleles↗
PubMed2000

Variations in subject pool as a function of earlier or later participation.

Data were obtained from 113 participants in a university subject pool during a 16-wk. semester. Without knowing the purpose of the study, participants self-selected to participate earlier (Weeks 3 and 4: n = 63) or later (Weeks 15 or 16) n = 50). Variations in scores on the NEO Personality Inventory--Revised, the Crowne-Marlowe Social Desirability Scale, the General Expectancy of Success Scale, the Shipley Institute of Living Scale, self-reported SATs and GPAs, and a measure of academic self-efficacy as a function of earlier or later participation were examined. Multivariate analysis of variance indicated that early participants differed significantly from later participants but not in predicted ways. Earlier participants scored higher on NEO PI-R Neuroticism; specifically men (n = 15) and women (n = 48) scored higher on Hostility, and women scored higher on Depression and Self-consciousness. An additional significant difference occurred for self-reported SAT Verbal scores for men, which were significantly higher for later participants. These temporal variations may represent confounds in research using university subject pools.

Adolescent↗
PubMed2000

Amino acid flux in ruminal and gastric veins of sheep: effects of ruminal and omasal injections of free amino acids and carnosine.

The possibility of free amino acid (FAA) and peptide absorption across the ruminant stomach wall was studied in multicatheterized wethers fed every 12 h. During the last third of the feeding cycle, two intraruminal or intraomasal injections of solutions containing increasing amounts of Ser, Gly, Val, Met, Phe, Lys, and carnosine were successively performed. Before injections, a net uptake of each of these FAA was measured in the ruminal and the gastric veins. The ruminal injections produced a linear increase in ruminal FAA concentration. The highest ruminal concentrations (observed with 3 g of FAA and carnosine) ranged between 5 and 14 mM. After ruminal injections, Ser (P < .05), Gly (P < .05), Val (P < .05), Met (P < .10), and Lys (P < .10) uptake decreased and carnosine net release linearly increased (P < .05), suggesting absorption across the ruminal epithelium. Owing to the low net flux generated by high ruminal concentration, the ruminal epithelium permeability to these molecules seemed to be low. After omasal injections, net flux of injected FAA were not modified, suggesting a low permeability of the gastric epithelia to FAA. Carnosine net release linearily increased (P < .05) with increasing level of carnosine injection, indicating the possibility of dipeptide absorption at the gastric level. This study demonstrated in vivo that the stomach epithelia possess the capacity to absorb FAA and small peptides; however, the permeability of these epithelia to these molecules seemed limited.

Absorption↗
PubMed2000

The effect of physical form of orchardgrass hay on the passage of particulate matter through the rumen of sheep.

Four Texel wethers (60 to 64 kg) fitted with ruminal and duodenal cannulas were used to study the kinetics of particulate matter in the rumen and the series of processes involved in their selection and passage. They were fed, in eight equal meals, 1,200 g of a mixture of a chopped orchardgrass hay and ground (8-mm screen) and pelleted orchardgrass hay in 90/10, 50/50, 30/70, or 10/90 ratios, according to a 4 x 4 Latin square design. The particle size distributions in feed, chewed feed, and ruminal, reticular, and duodenal digesta were determined by a wet-sieving procedure. Indigestible lignin was used as an internal marker to trace the passage of particles through the rumen. Digesta flow measurement was performed using the double-marker technique. We used a three-pool model, which partitions particles through the large, medium, and small particle pools, to determine the passage of lignin through those pools. Particle pool sizes and rumen and pool mean retention times (MRT) of lignin and of the rumen MRT of an ideal marker introduced separately in each pool were corrected for the "filter bed" effect. Grinding and pelleting of hay decreased the MRT of the indigestible lignin pool in the rumen. Particle MRT decreased and then reached a plateau with increased proportion of ground/pelleted hay in the diet. The diet with a ratio of 50/50 of chopped and ground/pelleted hay was the most favorable for the exit of particles from the rumen because of both a higher outflow rate from the rumen of particles eligible to exit and a sufficient comminution rate of larger particles to supply particles that were able to pass. For all diets, the large-particle comminution rate was always higher than the small-particle outflow rate, indicating that comminution was not the limiting step for passage. These results were the consequence of the curvilinear and opposite evolutions of both the particulate lignin pool in, and outflow from, the rumen. Those results contribute to an improved explanation of the mechanisms involved in the outflow of particles from the rumen.

Animal Feed↗
PubMed2000

Free and peptide amino acid net flux across the rumen and the mesenteric- and portal-drained viscera of sheep.

This experiment was conducted to determine the significance of the peptide amino acid (PAA) contribution to amino acid (AA) net flux in the portal vein and to evaluate the capacity for peptide absorption in the different segments of the gastrointestinal tract of ruminants. Four sheep (64+/-3 kg BW) were fitted with catheters and blood flow probes, allowing AA net flux measurements across the portal- (PDV) and mesenteric (MDV)-drained viscera and the rumen. Sheep were fed at maintenance a diet containing hay and extruded peas (70:30). Peptide absorption was investigated by a dose infusion of a mixture of peptides (casein hydrolysate, Pro-Phe, beta-Ala-His, Gly-Gly) into the rumen. Control and postinjection net fluxes of plasma free amino acids (FAA) and PAA were determined. The concentration of plasma PAA was determined by quantification of amino acids before and after acid hydrolysis of samples first submitted to chemical deproteinization and ultrafiltration (3-kDa cut-off filter). During the control period a significant net release (12 mmol/h) of PAA was observed across the PDV, which accounted for 35% of the sum of FAA and PAA net fluxes. This PDV flux of PAA mainly resulted from a MDV release of PAA (15 mmol/h). The net flux of total PAA across the ruminal wall was not significantly different from zero, but uptake of peptide Ile and release of peptide Gly were observed. The injection into the rumen of the peptide mixture increased the net release of peptide essential AA (EAA) across the MDV (P < .05) and the PDV (P < .10), and of peptide Pro and Phe across the non-MDV (P < .10). Peptide Ile uptake by the rumen tissues was decreased by the injection (P < .05). Significant increases in peptide Pro and Gly arterial concentrations were observed (P < .05). The 3-Ala-His and Gly-Gly arterial concentrations and net fluxes across the PDV were not affected by their injections into the rumen. This study showed that PAA may contribute significantly to AA flux across the PDV of sheep, and that part of this flux can probably be attributed to peptide absorption from the gut lumen. When high concentrations of peptides are generated in the rumen the possibility of peptide absorption before the jejunum has to be considered.

Amino Acids↗
PubMed2000

Effect of underfeeding on metabolism of portal-drained viscera in ewes.

We investigated whether short-term underfeeding could induce adaptative mechanisms in portal-drained viscera (PDV) that would allow nutrients to be spared for vital functions in adult ewes. Six ewes (three of them fitted with catheters in the mesenteric artery and portal and mesenteric veins) were fed, in a double Latin square design (2 weeks per experimental period), a regrowth of natural grassland hay at 143 (high; H), 88 (medium; M) and 51 (low; L) % of their energy maintenance requirements. The digestibility of the diet was measured in all six ewes and the net portal fluxes of nutrients in the three catheterized ewes. The organic matter content and N digestibility of the diet were not affected by underfeeding. Urinary and faecal N losses and N balance were linearly related to feed intake. Arterial concentration of acetate was linearly related to feed intake. Arterial concentrations of the other volatile fatty acids, 3-hydroxybutyrate, lactate, glucose, NH3, urea and total amino acids were not affected by underfeeding. Arterial concentration of non-esterified fatty acids (NEFA) increased with underfeeding. The portal net release of all volatile fatty acids, 3-hydroxybutyrate and NH3 were linearly related to intake. The portal net flux of both essential and non-essential amino acids, and thus total amino acids, remained unchanged between levels H and M, and decreased between levels M and L. A significant net uptake for glycine and total non-essential amino acids occurred at level L. The portal net uptake of glucose, urea, glutamate and glutamine, and the portal net release of lactate and NEFA were not affected by underfeeding. Summation of portal energy fluxes indicated that 51% of the metabolizable energy intake was recovered in the portal blood with the three levels of intake. In conclusion, no quantitative adaptation to spare energy, in terms of percentage of intake, occurred in PDV of short-term underfed ruminants, but the pattern of absorption of energetic nutrients was modified.

Adaptation, Physiological↗
PubMed1999

Effectiveness of CSE to counterstain particles and dead bacterial cells with permeabilised membranes: application to viability assessment in waters.

The CSE dye (Chemunex, Maisons-Alfort, France) was combined with an activity marker to improve bacterial activity assessment in natural waters. Its effectiveness to counterstain dead cells with permeabilised membranes was investigated on live and dead cells of a variety of strains from collections or isolated from the natural environment. Cells were killed by heat treatment. For all strains tested, the fluorescent dye showed an intense staining of killed cells having permeabilised membranes while no significant signal was detected when applied to live cells. Furthermore, the CSE dye had no toxicity on viable cells. Then, CSE was combined with the ChemChrome V6 dye (Chemunex) to assess the activity of bacterial cells in different waters. Both fluorescences were analysed simultaneously by solid-phase cytometry. The active cell counts were sometimes lower when both dyes were combined suggesting that CSE was able to counterstain cells having a residual esterase activity and compromised membranes. These cells were subtracted from the active cell counts determined with ChemChrome V6. In most samples, active cell counts were congruent with those determined by the direct viable count method.

Bacteria↗
PubMed1999

Identification of 6 new mutations in the iduronate sulfatase gene. Mutation in brief no. 233. Online.

Mucopolysaccharidosis type II (Hunter syndrome) is an X-linked lysosomal storage disorder caused by a deficiency of the enzyme iduronate-2-sulfatase. We sequenced genomic DNA and RT-PCR products in the iduronate sulfatase (IDS) gene in 6 unrelated patients with Hunter syndrome to assess genotype/phenotype relationships and offer carrier testing where required. Six novel mutations were identified: four missense mutations, one four-base pair deletion (596-599delAACA) and a cryptic splice site mutation. Three of the missense mutations were significant amino acid substitutions (S143F, S491F, E341K) of which the latter two involve amino acids conserved amongst sulfatase enzymes. The patients identified with these mutations all had a severe clinical phenotype. One missense mutation with a minimal amino acid substitution (H342Y), in a non-conserved region of the gene, was associated with a mild clinical phenotype. We identified a novel cryptic splice site (IVS5+934G>A) with some normal (wild type) mRNA processing. We predict that the normal mRNA product confered some residual functional enzyme, resulting in a mild phenotype associated with the absence of overt central nervous system disease.

Gene Deletion↗
PubMed1999

Mycobacterium kansasii septic arthritis: French retrospective study of 5 years and review.

Septic arthritis due to Mycobacterium kansasii is rare; only 40 cases have been published. A French national inquiry revealed the occurrence of 10 new cases between 1992 and 1997 (8 men and 2 women: mean age, 37 years; range, 25-54 years). Seven had an underlying condition: AIDS (n=4), chronic skin psoriasis and AIDS (n=2), or a renal transplant (n=1). Trauma to the joint, use of intra-articular corticosteroid(s) 1 month to 2 years after the event, and chronic skin psoriasis were risk factors. The mean interval between appearance of the first symptoms of arthritis and the diagnosis was 5 months. Monarthritis was localized to the knee (n=4), wrist (n=3), finger (n=1), elbow (n=1), or ankle (n=1). The main diagnostic procedure was culture of a synovial biopsy specimen. In all cases, debridement was associated with antimycobacterial treatment. Three patients died of AIDS during treatment, and another is still undergoing treatment; the other 6 patients were cured. M. kansasii infection should be considered in all cases of indolent arthritis with any of the following risk factors: local trauma, local or systemic corticosteroid therapy, chronic skin psoriasis, and immunodepression, especially that due to human immunodeficiency virus infection.

Adolescent↗
PubMed1999

Bacterial contamination of hospital physicians' stethoscopes.

Because stethoscopes might be potential vectors of nosocomial infections, this study, conducted in a 450-bed general hospital, was devised to evaluate the bacterial contamination of stethoscopes; bacterial survival on stethoscope membranes; the kinetics of the bacterial load on stethoscope membranes during clinical use; and the efficacy of 70% alcohol or liquid soap for membrane disinfection. Among the 355 stethoscopes tested, 234 carried > or =2 different bacterial species; 31 carried potentially pathogenic bacteria. Although some bacteria deposited onto membranes could survive 6 to 18 hours, none survived after disinfection.

Bacteria↗
PubMed1999

EYA4, a novel vertebrate gene related to Drosophila eyes absent.

We have isolated a family of four vertebrate genes homologous to eyes absent (eya), a key regulator of ocular development in Drosophila. Here we present the detailed characterization of the EYA4 gene in human and mouse. EYA4 encodes a 640 amino acid protein containing a highly conserved C-terminal domain of 271 amino acids which in Drosophila eya is known to mediate developmentally important protein-protein interactions. Human EYA4 maps to 6q23 and mouse Eya4 maps to the predicted homology region near the centromere of chromosome 10. In the developing mouse embryo, Eya4 is expressed primarily in the craniofacial mesenchyme, the dermamyotome and the limb. On the basis of map position and expression pattern, EYA4 is a candidate for oculo-dento-digital (ODD) syndrome, but no EYA4 mutations were found in a panel of ODD patients.

Alternative Splicing↗
PubMed1999

Sulfitobacter mediterraneus sp. nov., a new sulfite-oxidizing member of the alpha-Proteobacteria.

Analysis of PCR products of 16S rDNA of 680 isolates from Mediterranean Sea mesocosm experiments with taxon-specific 16S rDNA oligonucleotides revealed that 262 isolates belonged to the alpha subclass of the class Proteobacteria. Partial 16S rDNA sequence analysis of selected isolates and oligonucleotide probing with a Sulfitobacter-specific 16S rDNA probe affiliated 33 strains to the genus Sulfitobacter. Analysis of the HaeIII digest pattern of 16S rDNA revealed the presence of two groups; while 30 strains showed a pattern identical with that obtained for Sulfitobacter pontiacus DSM 10014T, a second group of three strains had a unique pattern that was different from that of the type strain. Five isolates of group 1 and one isolates of group 2, strain CH-B427T, were selected for detailed taxonomic analysis. All six isolates closely resembled the type strain Sulfitobacter pontiacus DSM 10014T in physiological reactions. However, strain CH-B427T differed quantitatively in the composition of fatty acids from Sulfitobacter pontiacus DSM 10014T and showed only 98.2% 16S rDNA sequence similarity with strain DSM 10014T. DNA-DNA reassociation value obtained for strains DSM 10014T and CH-B427T revealed 46% similarity. Based on the results of DNA-DNA reassociation and discrete differences in the nucleotide composition of 16S rDNA, a new species of the genus Sulfitobacter is proposed, designated Sulfitobacter mediterraneus sp. nov., the type strain being strain CH-B427T (= DSM 12244T).

Bacterial Typing Techniques↗