Biomedical subjects

S Trépanier

Publications and source records attributed to S Trépanier.

4 recordsLinked to original sources

PubMed1999

Detection of older people at increased risk of adverse health outcomes after an emergency visit: the ISAR screening tool.

OBJECTIVES: To develop a self-report screening tool to identify older people in the emergency department (ED) of a hospital at increased risk of adverse health outcomes, including: death, admission to a nursing home or long-term hospitalization, or a clinically significant decrease in functional status. DESIGN: Prospective (6-month) follow-up study of a cohort of ED patients aged 65 and older. SETTING: The EDs of four acute-care hospitals in Montreal, Quebec, Canada. PARTICIPANTS: Community-dwelling patients aged 65 and older who came to the EDs during the weekday shift over a 3-month recruitment period. Patients were excluded if they could not be interviewed either because of their medical condition or because of cognitive impairment and no other informant was available. MEASUREMENTS: Measures ascertained at the ED visit included: 27 self-report screening questions on social, physical, and mental risk factors; medical history; use of hospital services, medications, and alcohol; and the Older American Resources and Services (OARS) activities of daily living (ADL) scale. At follow-up, the OARS scale was readministered by telephone, and other adverse health outcomes were ascertained. RESULTS: Among 1673 patients who completed the follow-up measures, 488 (29.2%) had an adverse health outcome. Scale development and selection methods included logistic regression, receiver operating characteristic curves, and expert judgment. The proposed screening tool (ISAR) comprises six self-report questions on functional dependence (premorbid and acute change), recent hospitalization, impaired memory and vision, and polymedication. The tool performed well in the total cohort aged 65 and older, and in sub-groups defined by disposition (admitted or released from ED), language of questionnaire administration (French or English), information source (patient or other), and other characteristics. CONCLUSIONS: The ISAR is a short self-report questionnaire that can quickly identify older patients in the ED at increased risk of several adverse health outcomes and those with current disability.

Aged↗

PubMed1999

Structure-function studies of Ser-289 in the class C beta-lactamase from Enterobacter cloacae P99.

Site-directed mutagenesis of Ser-289 of the class C beta-lactamase from Enterobacter cloacae P99 was performed to investigate the role of this residue in beta-lactam hydrolysis. This amino acid lies near the active site of the enzyme, where it can interact with the C-3 substituent of cephalosporins. Kinetic analysis of six mutant beta-lactamases with five cephalosporins showed that Ser-289 can be substituted by amino acids with nonpolar or polar uncharged side chains without altering the catalytic efficiency of the enzyme. These data suggest that Ser-289 is not essential in the binding or hydrolytic mechanism of AmpC beta-lactamase. However, replacement by Lys or Arg decreased by two- to threefold the kcat of four of the five beta-lactams tested, particularly cefoperazone, cephaloridine, and cephalothin. Three-dimensional models of the mutant beta-lactamases revealed that the length and positive charge of the side chain of Lys and Arg could create an electrostatic linkage to the C-4 carboxylic acid group of the dihydrothiazine ring of the acyl intermediate which could slow the deacylation step or hinder release of the product.

Bacterial Proteins↗

PubMed1998

Screening for geriatric problems in the emergency department: reliability and validity. Identification of Seniors at Risk (ISAR) Steering Committee.

OBJECTIVE: To determine the test-retest reliability and concurrent criterion validity of a self-report ED screening questionnaire for adverse outcomes in elders. METHODS: A cohort of 1,885 patients aged > or = 65 years were recruited from the EDs of 4 Montreal hospitals. Patients were excluded if they could not be interviewed because of their clinical status or cognitive impairment and no informant was available. The screening questionnaire, administered in the ED, contained 27 items on social, physical, and mental risk factors, medical history, and use of hospital services, medications, and alcohol. A random sample of 404 patients were invited to participate in a clinical assessment 1-3 weeks after the ED visit, that included re-administration of the screening questionnaire, and standardized instruments to assess disability, social resources, depression, alcohol use and abuse, and current medications. RESULTS: Study data were collected from 221 patients (54.7%), of whom 193 were included in the test-retest reliability analyses and 213 in the analyses of concurrent validity. The concordance correlation coefficient for test-retest reliability of the risk factor score was 0.78 (95% confidence interval: 0.71, 0.83; n=193). Several screening questions showed moderately good agreement with the appropriate criterion standard, particularly those on visual and hearing impairment, depression, and use of medications. The best subset of 9 screening questions explained approximately half of the variance in the total disability score. CONCLUSIONS: The screening questionnaire score has good test-retest reliability, but individual screening questions have, at best, modest concurrent validity. The final set of screening questions should be selected based on their predictive validity.

Aged↗

PubMed1997

Characterization of the penA and penR genes of Burkholderia cepacia 249 which encode the chromosomal class A penicillinase and its LysR-type transcriptional regulator.

Burkholderia cepacia is recognized as an important pathogen in the lung infections of patients with cystic fibrosis. An inducible beta-lactamase activity has been associated with increased resistance to beta-lactam antibiotics in clinical isolates of B. cepacia. In this study, we report the revised sequence of the penA gene, which encodes the inducible penicillinase of B. cepacia, and show that it belongs to the molecular class A beta-lactamases and exhibits a high degree of similarity to the chromosomal beta-lactamase of Klebsiella oxytoca. Analysis of the nucleotide sequence of the DNA region directly upstream of the penA coding sequence revealed an open reading frame (penR), the transcription of which was oriented opposite to that of penA and whose initiation was 130 bp away from that of penA. Two potential ribosome-binding sites and two overlapping -10 and -35 promoter sequences were identified in the intercistronic region. The predicted translation product of penR was a polypeptide of 301 amino acids with an estimated molecular size of 33.2 kDa. The deduced polypeptide of penR showed a high degree of similarity with AmpR-like transcriptional activators of class A and C beta-lactamases, with identities of 59 and 58.7% with Pseudomonas aeruginosa PAO1 AmpR and Proteus vulgaris B317 CumR, respectively. The N-terminal portion of B. cepacia PenR was predicted to include a helix-turn-helix motif, which may bind the LysR motif identified in the intercistronic region. Induction of PenA by imipenem was shown to be dependent upon the presence of PenR. Expression of the cloned B. cepacia penA and penR genes in Escherichia coli SNO302 (ampD) resulted in a high basal and hyperinducible PenA activity. These results suggest that the regulation of the PenA penicillinase of B. cepacia 249 is similar to that observed in other class A and class C beta-lactamases that are under the control of a divergently transcribed AmpR-like regulator.

Amino Acid Sequence↗