Tissue engineering of functional articular cartilage: the current status

Osteoarthritis is a degenerative joint disease characterized by pain and disability. It involves all ages and 70% of people aged >65 have some degree of osteoarthritis. Natural cartilage repair is limited because chondrocyte density and metabolism are low and cartilage has no blood supply. The results of joint-preserving treatment protocols such as debridement, mosaicplasty, perichondrium transplantation and autologous chondrocyte implantation vary largely and the average long-term result is unsatisfactory. One reason for limited clinical success is that most treatments require new cartilage to be formed at the site of a defect. However, the mechanical conditions at such sites are unfavorable for repair of the original damaged cartilage. Therefore, it is unlikely that healthy cartilage would form at these locations. The most promising method to circumvent this problem is to engineer mechanically stable cartilage ex vivo and to implant that into the damaged tissue area. This review outlines the issues related to the composition and functionality of tissue-engineered cartilage. In particular, the focus will be on the parameters cell source, signaling molecules, scaffolds and mechanical stimulation. In addition, the current status of tissue engineering of cartilage will be discussed, with the focus on extracellular matrix content, structure and its functionality

What’s wrong with evolutionary biology?

There have been periodic claims that evolutionary biology needs urgent reform, and this article tries to account for the volume and persistence of this discontent. It is argued that a few inescapable properties of the field make it prone to criticisms of predictable kinds, whether or not the criticisms have any merit. For example, the variety of living things and the complexity of evolution make it easy to generate data that seem revolutionary (e.g. exceptions to well-established generalizations, or neglected factors in evolution), and lead to disappointment with existing explanatory frameworks (with their high levels of abstraction, and limited predictive power). It is then argued that special discontent stems from misunderstandings and dislike of one well-known but atypical research programme: the study of adaptive function, in the tradition of behavioural ecology. To achieve its goals, this research needs distinct tools, often including imaginary agency, and a partial description of the evolutionary process. This invites mistaken charges of narrowness and oversimplification (which come, not least, from researchers in other subfields), and these chime with anxieties about human agency and overall purpose. The article ends by discussing several ways in which calls to reform evolutionary biology actively hinder progress in the field

COMPARISON OF POSTURAL VARIABLE IN DIVISION 2 ATHLETES AND NON-ATHLETE COLLEGE STUDENTS

Johnathon L. Callum1 & Caleb A. Woodfield1 1Ouachita Baptist University, Arkadelphia, Arkansas Research has indicated a possible difference in the development of posture deformities in athletes and non-athletes. PURPOSE: This study was to identify posture differences in division 2 collegiate athletes and non-collegiate athletes and provide a two-week intervention to reduce discrepancies found. METHODS: 16 male athletes, 10 male non-athletes, 12 female athletes, and 13 female non-athletes participated. During the assessment, participants were evaluated from posterior and sagittal views with an adjusted REEDCO Posture Assessment. They were scored on a scale of 3 to 1 with 3 being good and 1 being poor in 10 categories with 30 being the max score. The volunteers were provided 4 stretches: neck extension, doorframe stretch, shoulder tuck, sitting up straight in a chair. They completed an anonymous survey indicating how often they did the intervention. RESULTS: The initial plumb line test average score for male athletes was 28.37, 27.10 for male non-athletes, 27.16 for female athletes, and 26.92 for female non-athletes. The final scores for male athletes were 28.93, 28.10 for male non-athletes, 29.16 for female athletes, and 28.69 for female non-athletes. 6% of the population said they did the intervention for 2 weeks, 23% did it for a week and a half, 51% did it for 1 week, and 20% didn\u27t do it at all. After conducting a one-way ANOVA test with the average scores of the final plumb line test a p-value of 0.1723 was found. Most group\u27s scores on average increased by 1.33 points after participating in the intervention. CONCLUSION: A difference in posture scores for the populations being tested was observed. Athletes had better initial and post posture scores than non-athletes. The intervention improved scores for most participants. A Limitation of the study includes not monitoring volunteers’ adherence to the intervention. When conducting future research keeping track of the exact sport or activities the athletes and non-athletes participate in would be beneficial. ACKNOWLEDGEMENTS: This study was funded by the Ouachita Baptist University Kinesiology Department