The aging mouse partially models the aging human spine: lumbar and coccygeal disc height, composition, mechanical properties, and Wnt signaling in young and old mice.

Murine lumbar and coccygeal (tail) regions of spines are commonly used to study cellular signaling of age-related disc diseases, but the tissue-level changes of aging intervertebral discs and vertebrae of each spinal region remain unclear. Furthermore, the impact of aging lumbar and coccygeal discs on Wnt/ß-catenin signaling, which is putatively involved in the catabolism of intervertebral discs, is also unclear. We compared disc/vertebrae morphology and mechanics and biochemical composition of intervertebral discs from lumbar and coccygeal regions between young (4-5 mo) and old (20-22 mo) female C57BL/6 mice. Center intervertebral disc height from both regions was greater in old discs than young discs. Compared with young, old lumbar discs had a lower early viscous coefficient (a measure of stiffness) by 40%, while conversely old coccygeal discs were stiffer by 53%. Biochemically, old mice had double the collagen content in lumbar and coccygeal discs of young discs, greater glycosaminoglycan in lumbar discs by 37%, but less glycosaminoglycan in coccygeal discs by 32%. Next, we compared Wnt activity of lumbar and coccygeal discs of 4- to 5-mo and 12- to 14-mo TOPGAL mice. Despite the disc-specific changes, aging decreased Wnt signaling in the nucleus pulposus from both spinal regions by ≥64%. Compared with young, trabecular bone volume/tissue volume and ultimate force were less in old lumbar vertebrae, but greater in old coccygeal vertebrae. Thus intervertebral discs and vertebrae age in a spinal region-dependent manner, but these differential age-related changes may be uncoupled from Wnt signaling. Overall, lumbar and coccygeal regions are not interchangeable in modeling human aging.

The 2005 Rose Prize Essay. GP Education in Northern Ireland 1920-1990. A study of the use and misuse of power.

The use and misuse of power has been demonstrated. It has been shown that GP education has changed very significantly between 1920 and 1990. Many excellent improvements have been achieved. Nevertheless, despite these gains, it is quite impossible to accept the hypothesis that there has been a constant steady improvement through history to the present perfect state (so-called Whiggism). Rather, it is clear that each and every one of the participants who provided GP medical education in Northern Ireland have made mistakes, of varying magnitude. However, the hypothesis of the conflict perspective is proven--the inevitable competition for power and the struggle for control were ever-present, and have been illustrated. This paper acknowledges that it is axiomatic that the medical profession should teach both its 'apprentices' and CME. For the medical profession to achieve a more independent position in this provision, the powers of state and the pharmaceutical industry would have to be curbed or controlled--in short, realigned. To reach this goal the medical profession's future planners would need to change. The various cliques would have to become a unified force. Only then would they have sufficient power to orchestrate and achieve the profession's proposals for GP education. An armistice could be agreed by the warrior bands (hospital consultants, the multiplicity of royal colleges including RCGP, and medico-political bodies such as the BMA) to allow this to happen. At this point, successful renegotiation of the conditions for GP education could become a real possibility. As a postscript, it must be acknowledged that there have been a great many significant developments in GP education since 1990; some are listed in Table II. These will require research elsewhere. Nevertheless, even after a further 15 years, the hypothesis remains sound; the competition for power and struggle for control are constants, and the schisms within medical education continue unabated.