Publications

BACKGROUND

Instructional forms of advance care planning depend on the ability of patients to predict their future treatment preferences. However, preferences may change with changes in patients' health states.

METHODS

We conducted in-home interviews of 226 older community-dwelling persons with advanced cancer, congestive heart failure, or chronic obstructive pulmonary disease at least every 4 months for up to 2 years. Patients were asked to rate whether treatment for their illness would be acceptable if it resulted in 1 of 4 health states.

RESULTS

The likelihood of rating as acceptable a treatment resulting in mild (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.06-1.16) or severe (OR, 1.06; 95% CI, 1.03-1.09) functional disability increased with each month of participation. Patients who experienced a decline in their ability to perform instrumental activities of daily living were more likely to rate as acceptable treatment resulting in mild (OR, 1.23; 95% CI, 1.08-1.40) or severe (OR, 1.23; 95% CI, 1.11-1.37) disability. Although the overall likelihood of rating treatment resulting in a state of pain as acceptable did not change over time (OR, 0.98; 95% CI, 0.96-1.01), patients who had moderate to severe pain were more likely to rate this treatment as acceptable (OR, 2.55; 95% CI, 1.56-4.19) than were those who did not have moderate to severe pain.

CONCLUSIONS

For some patients, the acceptability of treatment resulting in certain diminished states of health increases with time, and increased acceptability is more likely among patients experiencing a decline in that same domain. These changes pose a challenge to advance care planning, which asks patients to predict their future treatment preferences.

The mouse is increasingly important as a subject of vestibular research. Although many studies have focused on the vestibular responses of mice to angular rotation, the geometry of their semicircular canals has not been described. High-voltage X-ray computed tomography was used to measure the anatomy of the semicircular canals of two strains of mice, C57Bl/6J and CBA/CaJ. The horizontal plane of a stereotaxic coordinate system was defined by the midpoints of the external auditory meati and the point where the incisors emerge from the maxilla. The centroids of the lumens of the bony canals were calculated, and planes that describe the canals were fit using a least-squares regression analysis to the resulting points. Vectors normal to each regressed plane were used to represent the corresponding canal's axis of rotation, and angles of these vectors relative to skull landmarks as well as to each other were calculated. The horizontal canal of the mouse was found to be angled anteriorly upward 17.8 degrees for CBA/CaJ and 32.6 degrees for C57Bl/6J from the reference horizontal plane. Angles between ipsilateral canals deviated up to 12.3 degrees from orthogonal, and angles between contralateral synergistic canals (left anterior-right posterior, right anterior-left posterior, and horizontal-horizontal) deviated from parallel by up to 14.8 degrees. The orientations of the canals within the head as well as the orientations of the canals relative to each other were significantly different between the two strains, suggesting that care must be taken in the design and interpretation of developmental and physiologic studies involving different mouse strains.

BACKGROUND

The extent to which the horizontal transfer of virulence genes has contributed to the emergence of contemporary virulent strains of methicillin-resistant Staphylococcus aureus (MRSA) in hospital and community settings is poorly understood.

METHODS

Epidemiologically well-characterized MRSA isolates collected over 8.5 years were genotyped and tested for the presence of 34 virulence genes.

RESULTS

Six strain types accounted for 88.2% of all MRSA infections. The evolution of contemporary hospital and community phenotypes within the CC8 and CC30 lineages--2 background genomes that produced historical pandemic MRSA clones--were associated with multiple horizontal acquisitions of virulence genes. The epidemic community phenotype of a CC8 strain, designated ST8:USA300, was linked to the acquisition of staphylococcal cassette chromosome (SCC)mec type IV, the genes for Panton-Valentine leukocidin (PVL), and the enterotoxin Q and K genes. Similarly, the epidemic community phenotype of a CC30 strain, ST30:USA1100, was linked to the acquisition of SCCmec type IV and the pvl genes. In contrast, the epidemic hospital phenotype of another CC30 strain, ST36:USA200, was associated with the acquisition of SCCmec type II, the enterotoxin A gene, and the toxic shock syndrome toxin 1 gene. The pvl genes appear not to be essential for the evolution OF other community-associated strains of mrsa, including ST8:USA500 and ST59:USA1000.

CONCLUSIONS

The horizontal transfer of virulence genes, although infrequent, is epidemiologically associated with the emergence of new virulent strains of MRSA.