Validation of criterion-referenced standards for the mile run and progressive aerobic cardiovascular endurance tests.

The purpose of this study was to validate criterion-referenced standards for cardiovascular endurance tests using the criterion-groups validation model. Adolescent boys and girls assigned to either untrained or trained groups were administered the mile run and Progressive Aerobic Cardiovascular Endurance Run (PACER) tests. Selection of optimal criterion standards was based on finding a cutting score that minimized the probability of misclassification errors and maximized the probability of making correct decisions based on participation in physical activity. The results of this study suggest that recent changes in FITNESSGRAM standards are appropriate, especially for the PACER test. While modifications of standards have corrected somewhat for disparities in passing rates between the mile run and the PACER, especially for girls, further study of standards is necessary.

Ischemic optic neuropathy after hemorrhage from a cornual ectopic gestation.

A case of ischemic optic neuropathy resulting from uterine hemorrhage is reported in which a 37-year-old white woman, gravida 1, para 0, was diagnosed at 8 weeks' gestation with a ruptured ectopic pregnancy. After diagnostic laparoscopy the patient underwent a minilaparotomy, cornual wedge resection, and right salpingectomy with a total estimated blood loss of 3000 ml. Her postoperative course was uneventful until postoperative day 4, when the patient complained of vision loss for the last 1 to 2 days, total body edema, and headache. Ophthalmologic examination revealed findings consistent with ischemic optic neuropathy. Multiple studies of the cerebrospinal fluid were negative, as were computed tomography studies and magnetic resonance imaging of the head. Ischemic optic neuropathy, whose pathogenesis is still unclear, is a rare complication of massive hemorrhage and may cause permanent vision loss.

Integrative repair of articular cartilage in vitro: adhesive strength of the interface region.

The objective of this study was to quantify the strength of the repair tissue that forms at the interface between pairs of cartilage explants maintained in apposition in an in vitro culture system. Articular cartilage explants were harvested from calves and from adult bovine animals, dissected into uniform blocks, and incubated in pairs within a chamber that maintained a 4 x 5 mm area of tissue overlap. Following 1-3 weeks of incubation, integrative repair was assessed by testing samples in a tensile single-lap configuration to estimate adhesive strength. After incubation in medium containing 20% fetal bovine serum, the adhesive strength between pairs of calf cartilage blocks and pairs of adult bovine cartilage blocks increased at a rate of 7.0 and 10.5 kPa/week, respectively. This repair process appeared to be dependent on viable cells, since lyophilization of adult bovine cartilage before incubation completely inhibited the development of an interface with a measurable adhesive strength. The repair process was dependent on serum components in the medium. Incubation of sample pairs for 3 weeks in medium supplemented with 20% fetal bovine serum resulted in a relatively high proteoglycan content as well as a relatively high adhesive strength (34 kPa), whereas incubation in basal medium with or without 0.1% bovine serum albumin resulted in a 54-70% lower proteoglycan content and a 65-88% lower adhesive strength. Samples incubated for 3 weeks with serum also had a 20% higher DNA content than samples maintained in basal medium. Histological analysis indicated some cell division at the free surfaces of the explant and also occasional cells within the interface region between explants.