TGF-β1 as a prognostic factor in the process of early osteoarthrosis in the rabbit knee

AbstractObjective To assess changes in knee joint fluid concentrations of transforming growth factor-β1 (TGF-β1) and proteoglycan (PG) fragments during the early course of post-traumatic osteoarthrosis (OA) after meniscectomy in the rabbit knee, and to ascertain whether the concentrations of these substances shortly after operation could be used as prognostic markers for the OA process.Design In 15 rabbits with medial meniscectomy in one knee and a sham operation in the other knee, synovial lavage fluid samples were taken repeatedly, before operation, every third week post-operatively until 12 weeks, thereafter every sixth week, and at death. Five rabbits each were killed at 13, 25 and 40 weeks. Synovial lavage fluid samples from five non-operated rabbits served as controls. At death, two histological scores were formed that characterized the highest (MAX) and the overall (ALL) degree of OA changes in each joint.Results TGF-β1 and PG fragment concentrations in synovial lavage fluid correlated highly (R=0.81, P< 0.001). Both OA scores were higher in meniscectomized than controls (P< 0.05). The synovial lavage fluid concentration of TGF-β1 at 3 weeks, but no other time point, correlated to the histological scores (ALL, R=0.58; MAX, R=0.52;P< 0.001).Conclusion Higher concentrations of TGF-β1 in synovial lavage fluid early after surgery seemed indicative for the later development of more severe OA changes in contrast to lower concentrations. The association between TGF-β1 and the changes found later in the cartilage was underlined by the high correlations between this substance and PG fragment concentrations in synovial lavage fluid at all time points

Simultaneous changes in bone mineral density and articular cartilage in a rabbit meniscectomy model of knee osteoarthrosis

AbstractObjective It was hypothesized that increased bone mineral density of the medial proximal tibia would precede or coincide with the development of more severe cartilage changes after meniscectomy.Methods In a rabbit knee model, mineral density of subchondral bone and changes of articular cartilage were monitored 13 to 40 weeks after medial meniscectomy or a sham operation.Results Both procedures resulted in a decrease of bone mineral density, especially of the medial proximal tibia, which persisted up to 40 weeks (P< 0.02–0.0007). Meniscectomy induced cartilage changes typical for osteoarthrosis (P< 0.009), which progressed over time on the posterior aspect of the medial tibial plateau (P< 0.009), which is physiologically covered by the meniscus, but the procedure also induced iatrogenic changes which were located mainly on the anterior aspect of the concerned compartment, and which did not progress or develop to osteoarthrosis.Conclusions The data suggest that the cartilage changes after meniscectomy in this animal model are caused by the surgical trauma, subsequent limb misuse, and altered load distribution, and initially associated by a decrease not an increase in bone mineral density of the proximal tibia. Moreover, the cartilage changes progressed without a simultaneous increase of the bone mineral density at corresponding sites

Cellular control of protein levels: A systems biology perspective

Abstract How cells regulate protein levels is a central question of biology. Over the past decades, molecular biology research has provided profound insights into the mechanisms and the molecular machinery governing each step of the gene expression process, from transcription to protein degradation. Recent advances in transcriptomics and proteomics have complemented our understanding of these fundamental cellular processes with a quantitative, systems-level perspective. Multi-omic studies revealed significant quantitative, kinetic and functional differences between the genome, transcriptome and proteome. While protein levels often correlate with mRNA levels, quantitative investigations have demonstrated a substantial impact of translation and protein degradation on protein expression control. In addition, protein-level regulation appears to play a crucial role in buffering protein abundances against undesirable mRNA expression variation. These findings have practical implications for many fields, including gene function prediction and precision medicine

'Dressage Is Full of Queens!' Masculinity, Sexuality and Equestrian Sport

Attitudes towards sexuality are changing and levels of cultural homophobia decreasing, yet there remain very few openly gay men within sport. As a proving ground for heteromasculinity, sport has traditionally been a hostile environment for gay men. This article is based on an ethnographic study within a sporting subworld in which gay men do appear to be accepted: equestrian sport. Drawing on inclusive masculinity theory, equestrian sport is shown to offer an unusually tolerant environment for gay men in which heterosexual men of all ages demonstrate low levels of homophobia. Inclusive masculinity theory is a useful framework for exploring the changing nature of masculinities and this study demonstrates that gay men are becoming increasingly visible and accepted within once unreceptive locales, such as sport and rural communities. However, this more tolerant attitude is purchased at the expense of a subordinated feminine Other, perpetuating the dominance of men within competitive sport. © The Author(s) 2012

Learning masculinities in a Japanese high school rugby club

This paper draws on research conducted on a Tokyo high school rugby club to explore diversity in the masculinities formed through membership in the club. Based on the premise that particular forms of masculinity are expressed and learnt through ways of playing (game style) and the attendant regimes of training, it examines the expression and learning of masculinities at three analytic levels. It identifies a hegemonic, culture-specific form of masculinity operating in Japanese high school rugby, a class-influenced variation of it at the institutional level of the school and, by further tightening its analytic focus, further variation at an individual level. In doing so this paper highlights the ways in which diversity in the masculinities constructed through contact sports can be obfuscated by a reductionist view of there being only one, universal hegemonic patterns of masculinity

Space power distribution system technology. Volume 2: Autonomous power management

Electrical power subsystem requirements, power management system functional requirements, algorithms, power management subsystem, hardware development, and trade studies and analyses are discussed

Field responsive mechanical metamaterials.

Typically, mechanical metamaterial properties are programmed and set when the architecture is designed and constructed, and do not change in response to shifting environmental conditions or application requirements. We present a new class of architected materials called field responsive mechanical metamaterials (FRMMs) that exhibit dynamic control and on-the-fly tunability enabled by careful design and selection of both material composition and architecture. To demonstrate the FRMM concept, we print complex structures composed of polymeric tubes infilled with magnetorheological fluid suspensions. Modulating remotely applied magnetic fields results in rapid, reversible, and sizable changes of the effective stiffness of our metamaterial motifs

"It is what it is": masculinity, homosexuality, and inclusive discourse in mixed martial arts

In this paper we make use of inclusive masculinity theory to explore online media representations of male homosexuality and masculinity within the increasingly popular combat sport of mixed martial arts MMA). Adopting a case-study approach, we discuss narratives constructed around one aspirational male MMA fighter, Dakota Cochrane, whose history of having participated in gay pornography became a major talking point on a number of MMA 'fanzine'/'community' websites during early 2012. While these narratives attempted to discursively 'rescue' Cochrane's supposedly threatened masculinity, highlighting both his 'true' heterosexuality and his prodigious fighting abilities, they also simultaneously celebrated the acceptance of homosexual men within the sport which Cochrane's case implied. Thus, we suggest that these media representations of homosexuality and masculinity within MMA are indicative of declining cultural homophobia and homohysteria, and an inclusive vision of masculinity, as previously described by proponents of inclusive masculinity theory

Mass spectrometry-based high-throughput proteomics and its role in biomedical studies and systems biology

There are multiple reasons why the next generation of biological and medical studies require increasing numbers of samples. Biological systems are dynamic, and the effect of a perturbation depends on the genetic background and environment. As a consequence, many conditions need to be considered to reach generalizable conclusions. Moreover, human population and clinical studies only reach sufficient statistical power if conducted at scale and with precise measurement methods. Finally, many proteins remain without sufficient functional annotations, because they have not been systematically studied under a broad range of conditions. In this review, we discuss the latest technical developments in mass spectrometry (MS)-based proteomics that facilitate large-scale studies by fast and efficient chromatography, fast scanning mass spectrometers, data-independent acquisition (DIA), and new software. We further highlight recent studies which demonstrate how high-throughput (HT) proteomics can be applied to capture biological diversity, to annotate gene functions or to generate predictive and prognostic models for human diseases. Keywords: biomarker discovery; data-independent acquisition; dynamic biological systems; gene annotation; precision medicine; proteomics

'It's a Form of Freedom': The experiences of people with disabilities within equestrian sport

This paper explores the embodied, gendered experiences of disabled horse‐riders. Drawing on data from five in‐depth interviews with paradressage riders, the ways in which their involvement in elite disability sport impacts upon their sense of identity and confidence are explored, as well as the considerable health and social benefits that this involvement brings. Social models of disability are employed and the shortcomings of such models, when applied to disability sport, are highlighted. The data presented here demonstrates the necessity of seeing disability sport as an embodied experience and acknowledging the importance of impairment to the experiences of disabled athletes. Living within an impaired body is also a gendered experience and the implications of this when applied to elite disability sport are considered