No abstract

No abstract

Cholesterol and calcium phosphate, the latter in the form of hydroxyapatite, accumulate in atherosclerotic lesions. In this report, we demonstrate that these organic and inorganic constituents of lesions can accumulate together, closely associated in crystal agglomerates. Using the fluorescent cholesterol probe, filipin, we identified unesterified cholesterol that was associated with calcium granules in tissue sections of lesions. We also have shown that small crystallites of cholesterol can associate with preformed hydroxyapatite crystals in vitro. Scanning electron microscopy coupled with energy-dispersive X-ray analysis demonstrated the physical association of many small crystallites of cholesterol with larger crystals of hydroxyapatite. These small crystallites of cholesterol associated with hydroxyapatite stained with filipin. This contrasted with the lack of filipin staining of unassociated larger cholesterol crystals or hydroxyapatite alone. How cholesterol and calcium come to be closely associated in crystal agglomerates within atherosclerotic lesions remains to be determined.

No abstract

The purpose of this study was to investigate the adaptability of long bones of young adult rats to the stress of chronic aquatic exercise. Twenty-eight female Sabra rats (12 weeks old) were randomly assigned to two groups and treatments: exercise (14 rats) and sedentary control (14 rats) matched for age and weight. Exercised animals were trained to swim in a water bath (35 degrees +/- 1 degree C, 1 hour daily 5 times a week) for 12 weeks loaded with lead weights on their tails (2% of their body weight) (BW). At the end of the training period following blood sampling for alkaline phosphatase, all rats were sacrificed and the humeri and tibiae bones were removed for the following measurements: bone morphometry, bone water compartmentalization, bone density (BD), bone mineral content (BMC), and bone ions content (Ca, Pi, Mg, Zn). The results indicate that exercise did not significantly affect the animals' body weight, bone volume, or length and diameters. However, bone hydration properties, BD, bone mass, and mineralization revealed significant differences between swim-trained rats and controls (P less than 0.05). Longitudinal (R1) measurement was higher by 43% for both humerus and tibia, and Transverse (R2) relaxation rates of hydrogen proton were higher by 117 and 76% for humerus and tibia, respectively; fraction of bound water was higher by 36 and 46% for humerus and tibia, respectively. BD, bone weight, and ash were higher by 13%. BMC and bone ions content were higher by 10%, and alkaline phosphatase was higher by 67%.(ABSTRACT TRUNCATED AT 250 WORDS)