Human subject rear passenger symptom response to frontal car-to-car low-speed crash tests.

OBJECTIVE: The purpose of this study was to determine whether healthy adult volunteers report symptoms following exposure to low-speed frontal crashes at low velocities. METHODS: Nineteen medically screened, healthy, informed, and willing volunteers (17 men, 2 women; mean age, 37 years) were exposed to low-speed frontal crashes. All volunteers were seated in the rear seat position of the bullet vehicle. Closing velocities ranged from 4.1 to 8.3 mph (mean, 6.7 mph). For the bullet vehicle, the delta V ranged from 1.4 to 3.9 mph with a mean of 2.8 mph. RESULTS: Eighty-eight percent of volunteers attributed symptoms of discomfort to their crash exposure. All reported symptoms were transient, and none required medical treatment. The mean duration was 1 day. CONCLUSIONS: Even at relatively low speeds, there is no lower threshold below which it can be reasonably assumed that healthy and prepared volunteer rear seat passengers will not sustain some level of minor injury in a frontal collision. Although the reported mean delta V for injured persons in real-world frontal crashes has been reported to be as high as 8.1 mph, this does not offer any insight into the minimum threshold for such injuries among all at-risk vehicle occupants.

Pleiotropic effects of environment-specific adaptation in Arabidopsis thaliana.

Local adaptation may be important for the preservation of genetic diversity and the promotion of speciation. However, local adaptation may also constrain establishment in different environments. The consequences of local adaptation depend strongly on the pleiotropic effects of the genes involved in adaptation. Here, we investigated the pleiotropic effects of the genetic response to selection in outbred lines of Arabidopsis artificially selected to flower earlier under both winter- and spring-annual simulated conditions. The consequences of adaptation were evaluated by reciprocally transplanting selected and control lines between the two conditions. Selected lines always flower earlier than their controls, independent of growing conditions. However, selected lines, growing in the same condition in which they were selected, flower earlier than plants selected in the alternative environment. Plants selected to flower earlier in spring produce more fruits than controls when growing in the spring, and less fruits when growing in the winter; indicating that local adaptation has negative pleiotropic effects in another environment. Our results indicate that local adaptation can arise even when selection targets the same trait in the same direction. Furthermore, it suggests that adaptation under the two different environments can generate fitness trade-offs that can maintain genetic variation for flowering time.

Delayed gallstone abscess following laparoscopic cholecystectomy.

Delayed infectious complications following elective laparoscopic cholecystectomy have not been well delineated in the medical literature. Irretrievable spillage of gallbladder contents at the time of laparoscopic cholecystectomy is not rare, and has generally been felt to be of little consequence, particularly in the nonacute setting. The case presented documents an instance of delayed gallstone abscess formation after elective laparoscopic cholecystectomy. While rare, such cases highlight the need for refined techniques to prevent gallbladder, perforation during this procedure and to allow laparoscopic recovery of small gallstones spilled at the time of cholecystectomy.

Traumatic incarceration of the small bowel: case report.

While bowel injuries associated with blunt abdominal trauma are a well recognized entity, entrapment of bowel between vertebral bodies has seldom been described. The unusual case of traumatic jejunal incarceration between two lumbar vertebrae is presented.

Elevated serum levels of creatine kinase BB in autosomal dominant osteopetrosis type II--a family study.

A markedly elevated BB isoenzyme fraction of serum creatine kinase was noted in four male siblings and correlated with typical radiographic findings of autosomal dominant osteopetrosis Type II (ADO Type II). Patients with other sclerosing bone diseases had no elevation of CK-BB. The precision of the electrophoretic mobility patterns and correlation by I-125 tagged radioimmunoassay method confirms that this is CK-BB. We postulate that the dysfunctional and/or immature osteoclasts in ADO are more dependent on CK-BB than on the usual tricarboxylic acid cycle for the production of energy. The correlation of marked elevation of serum CK-BB with radiographic evidence of ADO Type II may prove to be of value as a biologic marker in the early diagnosis of the illness and lead to better understanding of the metabolism of bone.