The role of Plantaris Longus in Achilles tendinopathy: a biomechanical study.

BACKGROUND: The Plantaris Longus Tendon (PLT) may be implicated in Achilles (AT) tendinopathy. Different mechanical characteristics may be the cause. This study is designed to measure these. METHODS: Six PLT and six AT were harvested from frozen cadavers (aged 65-88). Samples were stretched to failure using a Minimat 2000™ (Rheometric Scientific Inc.). Force and elongation were recorded. Calculated tangent stiffness, failure stress and strain were obtained. Averaged mechanical properties were compared using paired, one-tailed t-tests. RESULTS: Mean stiffness was higher (p<0.001) in the PLT, measuring 5.71 N/mm (4.68-6.64), compared with 1.73 N/mm (1.40-2.22) in AT. Failure stress was also higher (p<0.01) in PLT: 1.42 N/mm(2) (0.86-2.23) AT: 0.20 N/mm(2) (0.16-0.25). Failure strain was less (p<0.05) in PLT: 14.1% (11.5-16.8) than AT: 21.8% (14.9-37.9). CONCLUSIONS: The PLT is stiffer, stronger than AT, demonstrating potential for relative movement under load. The stiffer PLT could tether AT and initiate an inflammatory response.

An evaluation of the BD-100R rechargeable neutron bubble dosimeter.

The purpose of this paper is to present data gathered in the evaluation of the BD-100R neutron bubble dosimeter done at the University of Maryland and the Naval Research Lab. The performance of 12 dosimeters has been followed over 15 exposure-recharge cycles under a wide range of exposure conditions. Included in this paper are the results from tests on dose rate dependence, neutron energy dependence, beta and gamma exposure, and recharge cycle performance. A statistical analysis of the reusability performance of the dosimeter as a function of dose equivalent is also presented.

Serum titres of Pneumocystis carinii antibody in health care workers caring for patients with AIDS.

BACKGROUND: Pneumocystis carinii pneumonia was thought to occur from reactivation of latent infection, but recent studies with the polymerase chain reaction have failed to detect P carinii in normal subjects. If pneumocystis pneumonia is therefore caused by new infection the source and mode of transmission of P carinii remains unknown. METHODS: Natural exposure to P carinii was detected by measuring antibodies by indirect immunofluorescence in 24 health care workers working continuously with patients with AIDS and 24 control health care workers exclusively treating elderly patients. RESULTS: P carinii antibody titres were significantly higher in the health care workers exposed to AIDS than in the control group (median titre 1:32 v 1:16 respectively). Three control subjects had no antibodies compared with none of the subjects exposed to AIDS, and 10 of the 12 highest titres came from the exposed group. CONCLUSIONS: Raised P carinii antibody titres in health care workers caring for patients with AIDS suggest that patients infected with HIV may be a potentially infectious source of P carinii for susceptible subjects.