A preliminary assessment of the medical and functional factors associated with vehicle crashes by older adults.

OBJECTIVES: To examine associations between medical and functional variables and at-fault car crashes in a cohort of older drivers. DESIGN: A case-control study. SETTING: A tertiary care medical center. PARTICIPANTS: Older drivers (ages 55-90 years) residing in Jefferson County, Alabama (n = 174). Cases were drivers who had at least one at-fault crash in the previous 6 years; controls were crash-free during the same period. MEASUREMENTS: Self-reported medical conditions, reported and observed functional measures, and urinary drug screens. The occurrence of one or more at-fault car crashes in the 6 years preceding the 1991 assessment date represented the outcome measure. RESULTS: Ninety-nine older drivers experienced between one and seven at-fault vehicle crashes during the period 1985 through 1991, whereas 75 drivers did not. Logistic regression models indicated that the following variables were independently associated with crash involvement: A 40% or greater reduction in the useful field of view (OR = 6.1; 95% CI, 2.9 to 12.7; P < 0.001), black race (OR = 6.6; 95% CI, 1.7 to 26.2; P = .007), a history of falling in the previous 2 years (OR = 2.6; CI, 1.1 to 6.1; P = .025), and not taking a beta-blocking drug (OR = 4.3; CI, 1.2 to 15.0; P = .023). CONCLUSIONS: Functional assessments, such as a comprehensive test of visual processing, a falls history, and a review of current medications may be of greater relevance than specific medical conditions in the identification of older at-risk drivers. If prospective studies determine that falling and crashing share risk factors, a unified approach to the prevention of these mobility disorders could result. The finding of an independent association of black race with at-fault crashing is in need of further clarification because of the low representation of black drivers in this sample.

Properties of calcium phosphate coatings before and after exposure to simulated biological fluid.

The surface qualities of calcium phosphate (CaP) implants are important factors determining the nature and degree of cellular behaviour, especially cellular attachment, proliferation and differentiation. Thus, in this study, the chemical composition and crystallographic properties of radiofrequency sputter-deposited CaP coatings prior to and after in vitro immersion in a physiological solution were characterized. Significant differences in crystallite size were observed with different heat treatments, with coatings heat treated at 850 degrees C (CA8) having larger crystallites compared to coatings heat treated at 700 degrees C (CA7). However, no statistical difference in the Ca/P ratio, carbon concentration and surface energy were observed with different heat treatments. After immersion in a physiological solution, the crystallite size was significantly increased. The crystallite size for the CA8 and CA7 coatings remained statistically different after 1-week immersion in solution. An increase in carbon concentration was also observed for both samples after 1-week immersion in solution. However, no significant differences in the Ca/P ratio and surface energy were indicated between the two coatings after 1-week immersion in solution. In addition, no statistical difference in surface energy was observed for both samples initially and after 1 week.

Economics of pancreatoduodenectomy in the elderly.

BACKGROUND: Managed care and the increasing percentage of surgical procedures performed in the elderly have renewed the focus on hospital charges and expenditures. The objective of this study was to determine whether septuagenarians and octogenarians accrue more hospital charges or have a higher risk of morbidity and death. METHODS: We retrospectively reviewed the charges and pertinent clinical outcomes data that were available on 70 of the last 100 pancreatoduodenectomies performed at our institution (1989 to 1994). Charges from four cost centers were analyzed and normalized to 1995 dollars by using the Consumer Price Index and Wilcoxon rank sum test. Patients were divided into two groups: group 1, 70 years of age or older (n = 21); group 2, younger than 70 years of age (n = 49). RESULTS: Anesthetic charges were $2657 +/- $835 for group 1 versus $2815 +/- $826 for group 2, which was not a statistically significant difference. Laboratory charges were $4650 +/- $3284 for group 1 versus $5969 +/- $5169 for group 2, which was not a significant difference. Pharmaceutical charges were $5424 +/- $4435 for group 1 versus $9243 +/- $9695 for group 2, which was not a significant difference. Charges for operative units were $6198 +/- $1671 for group 1 versus $7469 +/- $2116 for group 2, p < 0.02. Total charges were $41,180 +/- $20,635 for group 1 versus $50,968 +/- $33,783 for group 2, which was not a significant difference. No difference was noted in morbidity, mortality, length of stay, or survival. CONCLUSIONS: Pancreatoduodenectomy in the elderly can be performed safely without accruing higher cost, increased morbidity, or increased mortality.

Inhibitory effects of cocaine on NGF-induced neuronal differentiation: incomplete reversibility after a critical time period.

We extend our findings showing dose-dependent cocaine inhibition of differentiation in NGF-stimulated PC-12 cells without affecting cell viability by demonstrating that neurite extension is severely limited after 24 h, maximal effect is reached at 36 h and recovery is only partial. Cocaine metabolites lack these effects. A similar process may occur following human prenatal exposure, perhaps through cocaine-induced changes in gene expression or other intracellular signalling events.