Biomedical subjects

Guy Trudel

Publications and source records attributed to Guy Trudel.

20 records · Page 2Linked to original sources

PubMed2002

Review of growth plate closure compared with age at sexual maturity and lifespan in laboratory animals.

Although it is assumed that most mammals experience growth plate closure and cessation of bone growth soon after sexual maturity, bone growth in rats continues throughout their lifespan. The rat was compared to other laboratory animals to assess differences in the duration of bone growth and its relationship to age at sexual maturity and lifespan. We reviewed the literature from 1966 to March 1999 by searching MEDLINE and other databases. Growth closure times and age at sexual maturity were retrieved for the mouse, rabbit, dog, cat, sheep, cow, horse, nonhuman primates, and human. For all species, we calculated the ratios of: 1) age at growth plate closure to lifespan, 2) age at growth plate closure to age at sexual maturity, and 3) age at sexual maturity to average lifespan. The ratio of age at physis closure to the average lifespan was large for the rat (22 to 35) and showed some overlap with that of humans (17 to 25); this ratio was comparatively small in all other nonhuman species (range, 4 to 17). This finding indicates that bone growth continues in the rat for a greater proportion of their lifespan than does that in other species. The ratio of age at physis closure to age at sexual maturity was larger for the rat (5 to 6) than that for other species, indicating that bone growth continues much longer after sexual maturity in rats than in other animals. The ratio of age at sexual maturity to average lifespan was largest for humans and nonhuman primates (13 to 14), indicating the increased time to reach puberty versus that in other species. These differences are important for studies in which animal models are used in research involving bone growth.

Age Factors↗

PubMedDate not supplied

Tensile strength of the supraspinatus after reimplantation into a bony trough: an experimental study in rabbits.

The goals of this study were to determine the strength of the supraspinatus tendon after reimplantation into a bony trough and to find out whether the fibrocartilaginous enthesis reformed. In 21 rabbits, the supraspinatus tendon was transected and reinserted into a bony trough at the greater tuberosity. After sacrifice at 8 and 12 weeks, tensile strength was measured. Microscopically, the presence of fibrocartilage and the spatial orientation of the cartilage columns and collagen fibers were assessed. At sacrifice, 14 of 21 reinserted specimens had healed successfully and were studied. Most mechanical failures occurred through bone, and none failed at the site of reimplantation. The mean peak loads of the operated tendons were significantly lower than their controls (8 weeks, 134.8 +/- 49.9 N vs 223.1 +/- 33.4 N, and 12 weeks, 172.2 +/- 68.2 N vs 274.1 +/- 70.0; P =.013 and P =.025, respectively). Histologically, at 8 weeks, the fibrocartilaginous enthesis had partially reformed; it was narrower than normal, and the collagen fibers had only partially assumed their normal spatial arrangement. Twelve weeks after reimplantation, 4 of 7 entheses had a normal histologic appearance. We conclude that return of strength of the supraspinatus tendon is evident 8 weeks after surgical reattachment into a bony trough and that the fibrocartilaginous enthesis is normal in over half of the specimens at 12 weeks. The subchondral bone was weaker than the reinserted tendon. The results support the clinical practice of surgical reimplantation. Avoiding active exercises early while promoting them later could improve the surgical results and reduce the effects of disuse.

Animals↗