The anterolateral ligament of the knee: unwrapping the enigma. Anatomical study and comparison to previous reports.

It has been suggested that the anterolateral ligament (ALL) of the knee may have importance in limiting rotational instability, and reconstruction may prevent a continued pivot-shift following anterior cruciate ligament surgery. However, the anatomy of this ligament has not been consistently reported in recent publications. We describe our experience of cadaveric dissection with reference to other published work.This article is freely available via Open Access. Click on the 'Additional Link' above to access the full-text from the publisher's site.Published (Open Access

Exploiting notochord cells for stem cell-based regeneration of the intervertebral disc

The nucleus pulposus is an avascular and aneural tissue that has significant influence on the homeostasis and overall function of the intervertebral disc. The nucleus pulposus is comprised of a heterogeneous population of cells including large notochord cells and smaller chondrocyte-like cells. Loss of notochord cells has been correlated with the pathogenesis of disc degeneration and consequently, it has been hypothesized that regeneration of the disc could be mediated by notochord cells. Attempts to grow and expand notochord cells in vitro have thus far been limited by cell availability and ineffective culturing methodologies. As a result, co-culturing techniques have been developed in order to exploit notochord-derived signals for the differentiation of proliferative mesenchymal stem cells. A recent study by Korecki et al. has demonstrated that notochord cell conditioned medium has the ability to differentiate mesenchymal stem cells toward a nucleus pulposus-like fate, producing high levels of glycosaminoglycans and type III collagen. These findings suggest that growth factors and other soluble proteins may be able to stimulate endogenous IVD tissue maintenance in vivo. While this study advances our understanding of intervertebral disc cell-cell interactions, limitations remain in our ability to determine the phenotype of terminally differentiated cells within the nucleus pulposus (ie mature notochord cells) and therefore assess the relevance of differentiated mesenchymal stem cells for disc regeneration. In order for the field to progress, elucidation of the notochord phenotype remains of utmost importance

Proteaceae Leaf Fossils: Phylogeny, Diversity, Ecology and Austral Distributions

Foliar fossils of Proteaceae are reviewed, and useful specimens for interpreting evolution, and past and present distributions and environments are discussed. There are no definite Cretaceous occurrences. However, there is evidence of extant lineages dating from the Paleocene onwards, including tribe Persoonieae of subfamily Persoonioideae and each of the four tribes of subfamily Grevilleoideae. High diversity and abundance characterizes the Australian fossil record, including sclerophyllous and xeromorphic forms, but there is little evidence of the prominent extant subfamily Proteoideae. New Zealand had a much higher diversity of Proteaceae than at present, including Oligo-Miocene species of open vegetation. The South American leaf fossil record is not extensive. However, the fossil records of Embothrieae and Orites are consistent with the distributions of their extant relatives in South America and Australia being the result of vicariance. Overall, there is a need for more research on placing Proteaceae leaf fossils in a phylogenetic context.Raymond J. Carpente