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Biomedical subjects

A Rossier

Publications and source records attributed to A Rossier.

At least 19 recordsLinked to original sources
PubMed2004

Dissemination of CTX-M-type beta-lactamases among clinical isolates of Enterobacteriaceae in Paris, France.

We analyzed 19 clinical isolates of the family Enterobacteriaceae (16 Escherichia coli isolates and 3 Klebsiella pneumoniae isolates) collected from four different hospitals in Paris, France, from 2000 to 2002. These strains had a particular extended-spectrum cephalosporin resistance profile characterized by a higher level of resistance to cefotaxime and aztreonam than to ceftazidime. The bla(CTX-M) genes encoding these beta-lactamases were involved in this resistance, with a predominance of bla(CTX-M-15). Ten of the 19 isolates produced both TEM-1- and CTX-M-type enzymes. One strain (E. coli TN13) expressed CMY-2, TEM-1, and CTX-M-14. bla(CTX-M) genes were found on large plasmids. In 15 cases the same insertion sequence, ISEcp1, was located upstream of the 5' end of the bla(CTX-M) gene. In one case we identified an insertion sequence designated IS26. Examination of the other three bla(CTX-M) genes by cloning, sequencing, and PCR analysis revealed the presence of a complex sul1-type integron that includes open reading frame ORF513, which carries the bla gene and the surrounding DNA. Five isolates had the same plasmid DNA fingerprint, suggesting clonal dissemination of CTX-M-15-producing strains in the Paris area.

DNA Fingerprinting↗
PubMed2003

Aqueous dynamic and histological findings after deep sclerectomy with collagen implant in an animal model.

AIM: The use of an animal model to study the aqueous dynamic and the histological findings after deep sclerectomy with (DSCI) and without collagen implant. METHODS: Deep sclerectomy was performed on rabbits' eyes. Eyes were randomly assigned to receive collagen implants. Measurements of intraocular pressure (IOP) and aqueous outflow facility using the constant pressure method through cannulation of the anterior chamber were performed. The system was filled with BSS and cationised ferritin. Histological assessment of the operative site was performed. Sections were stained with haematoxylin and eosin and with Prussian blue. Aqueous drainage vessels were identified by the reaction between ferritin and Prussian blue. All eyes were coded so that the investigator was blind to the type of surgery until the evaluation was completed. RESULTS: A significant decrease in IOP (p<0.05) was observed during the first 6 weeks after DSCI (mean IOP was 13.07 (2.95) mm Hg preoperatively and 9.08 (2.25) mm Hg at 6 weeks); DS without collagen implant revealed a significant decrease in IOP at weeks 4 and 8 after surgery (mean IOP 12.57 (3.52) mm Hg preoperatively, 9.45 (3.38) mm Hg at 4 weeks, and 9.22 (3.39) mm Hg at 8 weeks). Outflow facility was significantly increased throughout the 9 months of follow up in both DSCI and DS groups (p<0.05). The preoperative outflow facility (OF) was 0.15 (0.02) micro l/min/mm Hg. At 9 months, OF was 0.52 (0.28) microl/min/mm Hg and 0.46 (0.07) micro l/min/mm Hg for DSCI and DS respectively. Light microscopy studies showed the appearance of new aqueous drainage vessels in the sclera adjacent to the dissection site in DSCI and DS and the apparition of spindle cells lining the collagen implant in DSCI after 2 months. CONCLUSION: A significant IOP decrease was observed during the first weeks after DSCI and DS. DS with or without collagen implant provided a significant increase in outflow facility throughout the 9 months of follow up. This might be partly explained by new drainage vessels in the sclera surrounding the operated site. Microscopic studies revealed the appearance of spindle cells lining the collagen implant in DSCI after 2 months.

Animals↗
PubMed2000

Comparison of PCR-ribotyping, arbitrarily primed PCR, and pulsed-field gel electrophoresis for typing Clostridium difficile.

Clostridium difficile is now recognized as the major agent responsible for nosocomial diarrhea in adults. Among the genotyping methods available, arbitrarily primed PCR (AP-PCR), PCR-ribotyping, and pulsed-field gel electrophoresis (PFGE) have been widely used for investigating outbreaks of C. difficile infections. However, the comparative typing ability, reproducibility, discriminatory power, and efficiency of these methods have not been fully investigated. We compared the results of three methods-AP-PCR with three different primers (AP3, AP4, and AP5), PCR-ribotyping, and PFGE (with SmaI endonuclease)-to differentiate 99 strains of C. difficile that had been previously serogrouped. Typing abilities were 100% for PCR-ribotyping and AP-PCR with AP3 and 90% for PFGE, due to early DNA degradation in strains from serogroup G. Reproducibilities were 100% for PCR-ribotyping and PFGE but only 88% for AP-PCR with AP3, 67% for AP-PCR with AP4, and 33% for AP-PCR with AP5. Discriminatory power for unrelated strains was >0.95 for all the methods but was lower for PCR-ribotyping among serogroups D and C. PCR-based methods were easier and quicker to perform, but their fingerprints were more difficult to interpret than those of PFGE. We conclude that PCR-ribotyping offers the best combination of advantages as an initial typing tool for C. difficile.

Bacterial Typing Techniques↗
PubMed1986

Upper and lower rib cage deformation during breathing in quadriplegics.

In quadriplegia, the anteroposterior diameter of the rib cage (RC) decreases during inspiration. Our aim was to characterize this paradoxical motion further and to determine to what extent it was due to a diminished inspiratory effect of the diaphragm on the RC because of abdominal muscle paralysis. In six quadriplegics, upper and lower RC (URC, LRC) displacements were studied in various postures with and without extrinsic abdominal support. LRC was in its relaxed configuration at all lung volumes studied in three subjects before and four subjects during abdominal compression. URC distorted most and, despite improvement during abdominal compression, was never in the relaxed configuration during tidal inspiration. Thoracic distortability was further studied by noting the effect on URC and LRC of a cephalad force applied to the RC at the costal margin. This produced distortion similar to that observed during spontaneous inspiration. It was concluded that during spontaneous inspiration in quadriplegics lack of abdominal support does not entirely explain the RC distortion which occurs, and high abdominal pressure results in diminished RC distortion, an effect which we attribute to an increase in the area of diaphragmatic apposition to the RC.

Abdomen↗
PubMed1986

Changes in lung volume and rib cage configuration with abdominal binding in quadriplegia.

Previous studies suggest that abdominal binding may affect the interaction of the rib cage and the diaphragm over the tidal range of breathing in quadriplegia. To determine whether abdominal binding influences rib cage motion over the entire range of inspiratory capacity, we used spirometry and the helium-dilution technique to measure functional residual capacity (FRC), inspiratory capacity, and total lung capacity (TLC) in eight quadriplegic and five normal subjects in supine, tilted (37 degrees), and seated positions. Combined data in all three positions indicated that, with abdominal binding, FRC and TLC decreased in normal subjects [delta FRC = -0.33 + 0.151 (SD) P less than 0.01); delta TLC = -0.16 + 0.121, P less than 0.05]. In quadriplegia there was also a reduction in FRC with binding (delta FRC = -0.32 + 0.101, P less than 0.001). However, TLC increased in quadriplegia (delta TLC = 0.07 + 0.061, P less than 0.025). In an additional six quadriplegic and five normal subjects, we used magnetometers to define the influences of abdominal binding on rib cage dimensions and TLC. In quadriplegia, rib cage dimensions were increased at TLC with abdominal binding, whereas there was no change in normals. Our data suggest that this inspiratory effect of abdominal binding on augmenting rib cage volume in quadriplegia is greater than the effect of impeding diaphragm descent, and thus abdominal binding produces a net increase in TLC in quadriplegia.

Abdomen↗
PubMed1981

Diaphragm electrical activity during negative lower torso pressure in quadriplegic men.

We recorded the diaphragm electromyogram (EMG) of quadriplegic men before and during exposure of the lower torso to continuous negative pressure, which caused shortening of the inspiratory muscles by expanding the respiratory system by one tidal volume. The moving-time-averaged diaphragm EMG was larger during expansion of the respiratory system. When we repeated the experiment with subjects who breathed through a mouthpiece, we found qualitatively similar EMG changes and little or no change in tidal volume or end-tidal CO2 partial pressure. When the pressure was applied or removed rapidly, changes in EMG occurred within one or two breaths. Because end-tidal CO2 partial pressure did not increase, and because the response was rapid, we suggest that the response results from proprioceptive, rather than chemoreceptive, reflexes. As most of these men had complete spinal lesions at C6 or C7 the afferent pathways are likely to be vagal or phrenic.

Adult↗
PubMed1978

Goitre and hypothyroidism in the newborn after cutaneous absorption of iodine.

Iodine goitre and hypothyroidism in 5 newborn infants in an intensive care unit were induced by cutaneous absorption of iodine, after numerous skin applications of iodine alcohol. The infant's skin permeability allows severe iodine overloading of the thyroid, resulting in goitre and hypothyroidism. Ioduria should always be sought in a newborn infant showing hypothyroidism. Iodine should not be used as a skin disinfectant in young infants.

Female↗