Search

Abstract: Background: Bone innervation is implicated in bone modeling and remodeling. This study investigates skeletal nerve development in embryonic and newborn mice, focusing on sensory and autonomic nerves and their temporal occurrence. Materials and methods: The ontogeny of innervation and angiogenesis in the hindlimb skeleton of mice was studied from embryonic day (E) 15 to postnatal day (P) 20. Neuronal tissue was immunohistochemically labeled for detection of growth associated protein 43 (GAP-43), protein gene product 9.5 (PGP 9.5), calcitonin gene-related peptide (CGRP), tyrosine hydroxylase (TH), and neuropeptide Y (NPY). Vascular endothelium was labeled for platelet endothelium cell adhesion molecule-1 (PECAM-1). Morphology was evaluated with hematoxylin and eosin staining. Results: GAP-43, PGP 9.5, CGRP, and PECAM-1 were all present at E 15, adjacent to areas with high osteogenic and chondrogenic activity. In the primary ossification centers, GAP-43 was found at E 15, PGP 9.5 at E 17, CGRP at E 19, and NPY at P 4. The same time lag in appearance was observed in the secondary ossification centers. The covering capillary network was initially dense, but became mature and sparse from P 12 onwards. Conclusion: A functional nerve supply co-localized with a rich capillary network is seen early in the developing mouse skeleton, especially in areas with high osteogenic activity. Sensory innervation occurs prior to partus, while autonomic innervation (revealed by the presence of NPY and TH) is established post partum. The findings indicate a time-related development of nerves with different qualities, according to skeletal development. [Copyright &y& Elsevier]

The frequency of new primary cancers was studied in 1846 postmenopausal patients included in a randomised trial of tamoxifen as an adjunct to primary surgery for early breast cancer. The median follow-up was 4.5 years (range 0.5-10.5 years). The number of new cancers in the tamoxifen group (n = 57) did not differ significantly from that in the control group (n = 70). However, in tamoxifen patients second breast cancers occurred less often and endometrial cancer occurred more often than in the controls. The increase in endometrial cancers was probably related to the agonistic oestrogenic effects of tamoxifen and was most pronounced in those treated for over 2 years. [ABSTRACT FROM AUTHOR]