Multidrug-resistant organism carriage among residents from residential care homes for the elderly in Hong Kong: a prevalence survey with stratified cluster sampling.

INTRODUCTION: A point prevalence survey was conducted to study the epidemiology of and risk factors associated with multidrug-resistant organism carriage among residents in residential care homes for the elderly (RCHEs). METHODS: A total of 20 RCHEs in Hong Kong were selected by stratified single-stage cluster sampling. All consenting residents aged ≥65 years from the selected RCHEs were surveyed by collection of nasal swab, axillary swab, rectal swab or stool on one single day for each home. Specimens were cultured and analysed for methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Acinetobacter (MDRA, defined as concomitant resistant to fluoroquinolones, carbapenems, aminoglycosides, cephalosporins and beta-lactam with or without beta-lactamase inhibitors), vancomycin-resistant Enterococcus (VRE), and carbapenemase-producing Enterobacteriaceae (CPE). One third of the MRSA-positive samples were selected at random for molecular typing; all positive MDRA, VRE and CPE samples were tested for molecular typing. Demographic and health information of residents including medical history, history of hospitalisation, antimicrobial usage, and use of indwelling catheters were collected to determine any associated risk factors. RESULTS: Samples of 1028 residents from 20 RCHEs were collected. Prevalence of MRSA was estimated as 30.1% (95% confidence interval [CI]=25.1%-35.6%) and MDRA 0.6% (95% CI=0.1%-4.1%). No residents carried VRE nor CPE. Residents living in privately run RCHEs were associated with MRSA carriage. Non-Chinese residents were associated with MRSA carriage with borderline significance. CONCLUSIONS: This survey provided information about multidrug-resistant organism carriage among RCHE residents. This information will enable us to formulate targeted surveillance and control strategies for multidrug-resistant organisms.

A health risk assessment of reclaimed municipal wastewater for industrial and miscellaneous use.

The study evaluated the safety of reclaimed water using health risk assessment and biotoxicity tests. The reclaimed water was produced from reverse osmosis and used in industrial and miscellaneous purposes. The health risk assessment was conducted based on the concentrations of detectable pollutants in reclaimed water in a hypothetical scenario. The estimated carcinogenic and non-carcinogenic risks are lower than the generally accepted level. Biotoxicity evaluation included three genotoxicity tests, a chronic toxicity test using medaka fishes, and a subchronic toxicity test using mice. The reclaimed water is not genetically toxic, and does not cause significant chronic effects on these model organisms. These results confirm the safety of using reclaimed water from municipal wastewater treatment plants.

Experienced surgeons can do more than one thing at a time: effect of distraction on performance of a simple laparoscopic and cognitive task by experienced and novice surgeons.

BACKGROUND: While operating, surgeons are required to make cognitive decisions and often are interrupted to attend to questions from other members of the health care team. Technical automatization may be achieved by experienced surgeons such that these distractions have little effect on performance of either the surgical or the cognitive task. This study assessed the effect of adding a distracting cognitive task on performance of a basic laparoscopic skill by novice and experienced surgeons. METHODS: In this study, 31 novice (medical students in postgraduate years [PGYs] 1-2) and 9 experienced (fellows/attendants and PGYs 4-5) laparoscopic surgeons practiced the Fundamentals of Laparoscopic Surgery (FLS) laparoscopic peg transfer task until their scores stabilized. The mean normalized score after five repetitions then was recorded. The subjects also were tested on the number of mathematical addition questions they could answer in 1 min. This was repeated five times, with the mean number of questions attempted and the accuracy (% correct) recorded. The laparoscopic and addition tasks then were performed concurrently five times. Data, presented as mean +/- standard deviation, were analyzed using Student's t-test. A p value less than 0.05 was considered statistically significant. RESULTS: After practice to stable peg transfer performance, the baseline peg transfer score was higher in the experienced group (98 +/- 6 vs 87 +/- 12; p < 0.01). There were no baseline differences between the groups in the number of math questions attempted in 1 min (10 +/- 2 vs 9 +/- 2; p = 0.55) or the number of correct answers (9 +/- 3 vs 8 +/- 3; p = 0.36). The comparison of baseline performance and dual-task performance showed that the experienced surgeons had no decline in peg transfer score (98 +/- 6 vs 97 +/- 6; p = 0.48), number of questions attempted in 1 min (10 +/- 2 vs 9 +/- 3; p = 0.32), or number of correct answers (9 +/- 3 vs 8 +/- 3; p = 0.46). In contrast, dual-tasking among the novices was associated with a decrease in the number of questions attempted (9 +/- 2 vs 8 +/- 2; p < 0.01) and the number of correct answers (8 +/- 3 vs 7 +/- 2; p = 0.02), and with no change in the peg transfer score (87 +/- 12 vs 88 +/- 8; p = 0.38) compared with baseline. CONCLUSIONS: Distraction significantly decreased a novice's ability to process cognitively based math problems, whereas there was no effect on experienced subjects. This occurred despite the fact that the novice group had practiced to high-level peg transfer scores at baseline. This suggests that the experienced surgeons had achieved automatization of the peg transfer basic surgical skill to a level that cognitive distraction did not affect performance of either task. The experienced surgeons were able to attend equally to both tasks, whereas the novices attended to the surgical task at the expense of some aspects of cognitive task performance.

Identification of the retinoic acid-inducible all-trans-retinoic acid 4-hydroxylase.

Retinoic acid (RA) metabolites of vitamin A are key regulators of gene expression involved in embryonic development and maintenance of epithelial tissues. The cellular effects of RA are dependent upon the complement of nuclear receptors expressed (RARs and RXRs), which transduce retinoid signals into transcriptional regulation, the presence of cellular retinoid-binding proteins (CRABP and CRBP), which may be involved in RA metabolism, and the activity of RA metabolizing enzymes. We have been using the zebrafish as a model to study these processes. To identify genes regulated by RA during exogenous RA exposure, we utilized mRNA differential display. We describe the isolation and characterization of a cDNA, P450RAI, encoding a novel member of the cytochrome P450 family. mRNA transcripts for P450RAI are expressed normally during gastrulation, and in a defined pattern in epithelial cells of the regenerating caudal fin in response to exogenous RA. In COS-1 cells transfected with the P450RAI cDNA, all-trans-RA is rapidly metabolized to more polar metabolites. We have identified 4-oxo-RA and 4-OH-RA as major metabolic products of this enzyme. P450RAI represents the first enzymatic component of RA metabolism to be isolated and characterized at the molecular level and provides key insight into regulation of retinoid homeostasis.