Bone mass and muscle strength in female college athletes (runners and swimmers).

OBJECTIVE: To determine whether female college athletes had increased muscle strength and bone mass in comparison with age-matched nonathletic female subjects and, if so, whether participation in weight-bearing versus non-weight-bearing exercise made a difference. MATERIAL AND METHODS: We performed a comparative statistical analysis of the bone mineral density (BMD) of the total body, lumbar spine, and femoral neck, maximal oxygen uptake (VO2max), muscle strength, and level of physical activity in 21 runners, 22 swimmers, and 20 control subjects. The study participants were female college students, 18 to 24 years old, who had had more than 8 normal menstrual cycles during the past year. RESULTS: Statistical analyses showed significantly higher VO2max in the two athletic study groups than in the control subjects (P < 0.0001). No significant difference in BMD was noted among the three groups. Total body BMD (r = 0.30; P = 0.02) and femoral neck BMD (r = 0.39; P = 0.002) were positively correlated with weight-bearing activity but not with non-weight-bearing activity. VO2Max (an index of physical fitness) was positively correlated with femoral neck BMD (r = 0.33; P = 0.009) and trochanteric BMD (r = 0.29; P = 0.021). Shoulder muscle strength (determined by isokinetic dynamometry) was positively correlated with total body BMD (r = 0.34; P = 0.007) and lumbar spine BMD (r = 0.28; P = 0.028). Swimmers had higher muscle strength in the back and upper extremities than did runners and control subjects. Hip girdle muscle strength was not significantly different among the three groups. Total body BMD had a positive correlation with percentage of body fat and height. Lumbar spine BMD was higher in subjects who had previously used oral contraceptives. The athletes had a lower percentage of body fat, were less likely to have used oral contraceptives, and had fewer years of normal menses than did the control subjects. CONCLUSION: Our study shows that (1) total body BMD and femoral neck BMD were significantly higher in the study group that performed weight-bearing exercises than in control subjects, (2) swimming exercise had no effect on BMD, and (3) although swimming is not a bone-building exercise, it can significantly improve shoulder, back, and grip muscle strength.

Efficacy of esophageal bougienage by emergency physicians in pediatric coin ingestion.

STUDY OBJECTIVE: To determine the efficacy and safety of bougienage performed by properly trained pediatric emergency medicine physicians to advance a recently ingested coin lodged in the esophagus into the stomach. METHODS: We carried out a prospective study of consecutive cases at two university-affiliated pediatric hospitals. Our subjects were 31 children, each with an ingested coin lodged in the esophagus, who met criteria for bougienage: a single coin ingested in the preceding 24 hours, radiographically localized in the esophagus; no history of esophageal disease, esophageal surgery, or foreign body removal; and no sign of respiratory compromise. The bougienage procedure involved a single pass of a Hurst bougie dilator from the mouth to the stomach with the unsedated patient sitting upright. RESULTS: In all cases, the coin was successfully advanced into the stomach with a single pass of the bougie dilator. No patient experienced an acute complication or delayed surgical complication related to the procedure. In one case the coin was vomited after the procedure and recovered without complications. Mild abdominal pain developed in two patients, who were reevaluated 2 weeks after the procedure. In each case the coin was present in the stomach and was removed endoscopically without subsequent complications. CONCLUSION: When used by trained emergency physicians, esophageal bougienage is a safe, effective, cost-containing treatment for dislodging and advancing ingested coins from the esophagus into the stomach that requires no sedation or general anesthesia.

The capillary thrombometer and von Willebrand factor.

A modified capillary thrombometer was constructed to study the rate of thrombus formation using heparinized whole blood (2 U/ml) from 4 different groups of pigs: normal, heterozygous von Willebrand's disease (vWD), homozygous vWD, and platelet storage pool disease (SPD). The median thrombosis times for the 4 groups of pigs were: 5.3 min (range = 3.0-14), 31 min (range = 4.0-47), 55 min (range = 41-60), and 60 min (range = 15-60), respectively. Significant differences were demonstrated between all pig groups (p less than .01 - p less than .001), except between the homozygous vWD pigs and the SPD pigs (p = 0.8), both of which are clinical bleeders. Cryoprecipitate was infused into 3 pigs with homozygous vWD. Partial correction of the capillary thrombometer thrombosis time and the in vivo ear bleeding time was observed. Murine monoclonal antibodies to porcine von Willebrand factor were added to normal pig whole blood samples in the capillary thrombometer. Four of six antibodies prolonged the thrombosis time and had similar effects on the ear bleeding time. Using these monoclonal antibodies, an immunoperoxidase stain demonstrated plasmatic and platelet associated von Willebrand factor in sections of thrombi from the capillary thrombometer. These experiments confirm that von Willebrand factor is important to thrombus formation in the capillary thrombometer and that measurements by this instrument may relate to in vivo hemostasis as measured by the ear bleeding time.

The capillary thrombometer revisited.

A modified capillary thrombometer was constructed to study the rate of thrombus formation using heparinized whole blood (2 U/ml) obtained from normal adults (n = 22) and children (n = 20) and patients with hemophilia A (n = 10) or von Willebrand's disease (n = 8). The median thrombosis times were as follows: normal adults = 12.8 min (range = 4.5-26.0), normal children = 13.3 min (range = 5.7-29.0), patients with hemophilia A = 37.2 min (range = 20.0-60.0 min), and patients with von Willebrand's disease = 60.0 min (range = 37.2-60.0). Significant differences were demonstrated between all groups of subjects, except between normal adults and children. The capillary thrombometer appears to measure thrombus formation dependent on adequate Willebrand factor and platelets.