Acetabular labrum reconstruction with fresh meniscus allograft transplantation : validation in a preclinical canine model

"Acetabular labrum pathology is frequently diagnosed in young, active individuals. Methods of hip preservation emphasize recapitulation of labrum structure and function to re-establish joint health and mitigate the development of hip osteoarthritis (OA). Labrum reconstruction utilizing fresh, frozen tendon allograft has become a popular option based on good short-term outcomes, however, failure rates are ~24%. Meniscus allograft has demonstrated early success as an alternative due to similarities in geometry, tissue composition, and metabolic profile when compared to acetabular labrum tissue. Healing of the fresh (viable) meniscus allografts transplantation (MAT) has not been well characterized."--Introduction

Regional differences in femoral condyle cartilage biomarkers related to histological degradation severity in the osteoarthritic knee

Introduction and purpose: There is significant variation in the development and progression of articular cartilage lesions across the surface of the femoral condyle (FC) during Osteoarthritis (OA). The complex relationships among localized changes in the structure of articular cartilage on the FC and the tissue concentration of protein biomarkers associated with OA development and progression are not well characterized. This study was designed to characterize relationships among OA-related changes in cartilage structure with the concentrations of clinically relevant protein biomarkers in cartilage tissue recovered from femoral condyles of OA patients. Hypothesis: There will be significant differences in the regional concentration of inflammatory, degradation-related, and bone turnover-related biomarkers in OA cartilage tissue recovered from the femoral condyle based on histological severity of degenerative cartilage

Phenotypic plasticity in sperm production rate : there's more to it than testis size

Evolutionary theory predicts that males should produce more sperm when sperm competition is high. Because sperm production rate is difficult to measure in most organisms, comparative and experimental studies have typically used testis size instead, while assuming a good correspondence between testis size and sperm production rate. Here we evaluate this common assumption using the marine flatworm Macrostomum lignano, in which we can estimate sperm production rate because the accumulation of produced sperm can be observed in vivo. In earlier studies we have shown that testis size is phenotypically plastic in M. lignano: worms can be induced to make larger testes by raising them in groups instead of pairs, and these larger testes have a higher cell proliferation activity (i.e. they are more energetically costly). Here we demonstrate that worms with such experimentally enlarged testes have a higher sperm production rate. Moreover, although testis size and sperm production rate were related linearly, worms with experimentally enlarged testes had a higher sperm production rate per unit testis size (i.e. a higher spermatogenic efficiency). We thus show that phenotypically plastic adjustment of sperm production rate includes a component that is independent of testis size. We discuss possible reasons for this novel finding, and suggest that the relationship between testis size and sperm production needs to be evaluated in other species as well

Sperm production in an extremophile fish, the cave molly (Poecilia mexicana, Poeciliidae, Teleostei)

A prominent trade-off in life history theory and evolution balances the costs of reproduction with those of basic somatic needs. Hence, reproductive efforts may be reduced in environments where additional energy is required for somatic maintenance. Here, we investigated male sperm stores in Atlantic mollies (Poecilia mexicana) from a sulfidic cave and several sulfidic and non-sulfidic surface habitats. We found significant differences among populations in the number of sperm stripped per male, which was also correlated with differences in gonad weights. The largest sperm stores were detected in males from non-sulfidic surface creeks, while males from a partially sulfidic surface system had lower sperm counts, and males from completely sulfidic systems, surface as well as subterranean, had even fewer available sperm. We conclude that the extreme environmental conditions in sulfidic habitats appear to constrain male sperm production, since hydrogen sulfide as a naturally occurring toxin requires energy-demanding adaptations. Furthermore, we examined sperm counts of lab-reared cave and surface mollies in response to energy limitation. Males from stock populations were placed under high and low food treatments for a 2-week period and then stripped of sperm. Sperm counts of surface mollies tended to be reduced by low food availability, whereas sperm counts of cave mollies did not significantly vary between food treatments, which likely points towards a higher starvation resistance in cave mollies