Tear and skin phospholipids:analysis and hydrogel analogues

This thesis is concerned with the analysis of phospholipids in the tear film and with the synthesis of phospholipids analogous to hydrogels. The work consists of two areas. The first area is the study of the phospholipids in the tear film, their nature and fate. The use of liquid chromatography mass spectrometry determined that the concentration of phospholipids in the tear film was less than previously thought. The analysis of the tear film phospholipids continued with thin layer chromatography. This showed the presence of diacylglycerides (DAGs) in the tear film at relatively high concentrations. The activity of an enzyme, phospholipase C, was found in the tear film. It was hypothesised that the low concentration of phospholipids and high concentrations of DAG in the tear film was due to the action of this enzyme. The second area of study was the synthesis of phospholipids analogous materials for use in ocular and dermal applications for use in ocular and dermal applications.For ocular applications the synthesis involved the use of the monomer N,N-dimethyl-N-(2-acryloylethyl)-N-(3-sulfopropyl) ammonium betaine (SPDA) in combination with 2-hdyroxyethyl methacrylate (HEMA). Charge-balanced membranes were also synthesised using potentially anionic monomers in conjunction with cationic monomers in stoichiometrically equivalent ratios also with HEMA as a commoner. Membranes of SPDA copolymers and charge-balanced copolymers proved to have some properties suitable for ocular applications. The dermal materials consisted of one family of partially hydrated hydrogels synthesised from SPDA in combination with ionic monomers: sodium 2-(acrylamido)-2-methyl propane sulfonate and acrylic acid-bis(3-sulfopropyl)-ester, potassium salt. A second family of partially hydrated hydrogels was synthesised from N-vinyl pyrrolidone in combination with the same ionic monomers. Both of the partially hydrated hydrogels synthesised proved to have some properties suitable for use as adhesives for the skin

How much can exercise raise creatine kinase level-- and does it matter?

Moderate-intensity exercise (maintaining heart rate between 55% and 90% of maximum) may elevate creatine kinase (CK) to levels that meet the diagnostic criteria for rhabdomyolysis if the exercises involve eccentric muscle contractions, such as weight lifting or downhill running (strength of recommendation [SOR]: C, small observational studies). The clinical significance of exercise-induced elevations in CK is unclear because the renal complications associated with classic rhabdomyolysis haven't been observed

'We are the selfie generation!': an ethnographic study of contemporary bodily culture within a Scottish school and physical education context

Schools are rich and intense social environments where young people constantly interact with one another, negotiate social relationships and construct their identities. The school context also influences how young people experience and relate to their bodies. Physical education can be especially influential here – an environment where young people learn about the body and through the body within a highly visible setting. Research has investigated how bodily meanings and power relations are constructed within schools and physical education but these processes are ever evolving. For example, the ingraining of online social interaction within young people’s lives currently adds new dimensions to how young people learn, interact and perceive themselves and their bodies. This thesis presents findings from a year-long ethnographic study located within a Scottish secondary school. Participant observation and qualitative interviews were used to explain the contemporary bodily culture amongst young people and to investigate how engagements with online social spaces were shaping young people’s bodily perceptions and practices. Findings evidenced three overarching tenets of informal pupil culture. These were: the centrality and importance of the body within social life; the omnipresence of online social spaces and online social interaction; and the development of a celebrity-esque culture amongst the pupil population. Accordingly, pupils constructed and negotiated hyper-risky social environments where the body and the self were hyper-visible, hyper-scrutinised and hyper-controlled. Working within a critical realist framework, theoretical insights from Erving Goffman, Michel Foucault and Pierre Bourdieu were utilised to suggest that the online environment represented a very important and attractive medium for identity construction where young people had opportunities, and felt pressure, to create idealised images of themselves. Online self-presentation also had offline implications for how pupils behaved, viewed themselves and for how they perceived and treated others. Physical education therefore became an especially risky social space as it was characterised by a lack of control over bodily identity, which juxtaposed sharply with the intense control over self-presentation afforded online. The online realm was also a highly influential context for learning about health and the body and a space where looking ‘healthy’ was very fashionable. Accordingly, this thesis suggests that socially safe and critical environments should be constructed in physical education. The thesis also concludes by arguing that physical education has unique potential to contribute positively to young people’s lives through practical, experiential learning. Physical education can foster and create a refreshing culture, contrasting and challenging superficial dimensions of contemporary bodily culture. It can become a space that diminishes the significance of outward experiences: a space where young people positively experience their bodies and the world around them; where they can reflect and marvel upon such experiences; and learn to respect their own and each other’s bodies in a very intrinsic and deep sense

The initiator methionine tRNA drives secretion of type II collagen from stromal fibroblasts to promote tumor growth and angiogenesis

Summary: Expression of the initiator methionine tRNA (tRNAi Met) is deregulated in cancer. Despite this fact, it is not currently known how tRNAi Met expression levels influence tumor progression. We have found that tRNAi Met expression is increased in carcinoma-associated fibroblasts, implicating deregulated expression of tRNAi Met in the tumor stroma as a possible contributor to tumor progression. To investigate how elevated stromal tRNAi Met contributes to tumor progression, we generated a mouse expressing additional copies of the tRNAi Met gene (2+tRNAi Met mouse). Growth and vascularization of subcutaneous tumor allografts was enhanced in 2+tRNAi Met mice compared with wild-type littermate controls. Extracellular matrix (ECM) deposited by fibroblasts from 2+tRNAi Met mice supported enhanced endothelial cell and fibroblast migration. SILAC mass spectrometry indicated that elevated expression of tRNAi Met significantly increased synthesis and secretion of certain types of collagen, in particular type II collagen. Suppression of type II collagen opposed the ability of tRNAi Metoverexpressing fibroblasts to deposit pro-migratory ECM. We used the prolyl hydroxylase inhibitor ethyl- 3,4-dihydroxybenzoate (DHB) to determine whether collagen synthesis contributes to the tRNAi Met-driven pro-tumorigenic stroma in vivo. DHB had no effect on the growth of syngeneic allografts in wild-type mice but opposed the ability of 2+tRNAi Met mice to support increased angiogenesis and tumor growth. Finally, collagen II expression predicts poor prognosis in high-grade serous ovarian carcinoma. Taken together, these data indicate that increased tRNAi Met levels contribute to tumor progression by enhancing the ability of stromal fibroblasts to synthesize and secrete a type II collagen-rich ECM that supports endothelial cell migration and angiogenesis

International Society of Sports Nutrition position stand: protein and exercise

<p>Abstract</p> <p>Position Statement</p> <p>The following seven points related to the intake of protein for healthy, exercising individuals constitute the position stand of the Society. They have been approved by the Research Committee of the Society. 1) Vast research supports the contention that individuals engaged in regular exercise training require more dietary protein than sedentary individuals. 2) Protein intakes of 1.4 – 2.0 g/kg/day for physically active individuals is not only safe, but may improve the training adaptations to exercise training. 3) When part of a balanced, nutrient-dense diet, protein intakes at this level are not detrimental to kidney function or bone metabolism in healthy, active persons. 4) While it is possible for physically active individuals to obtain their daily protein requirements through a varied, regular diet, supplemental protein in various forms are a practical way of ensuring adequate and quality protein intake for athletes. 5) Different types and quality of protein can affect amino acid bioavailability following protein supplementation. The superiority of one protein type over another in terms of optimizing recovery and/or training adaptations remains to be convincingly demonstrated. 6) Appropriately timed protein intake is an important component of an overall exercise training program, essential for proper recovery, immune function, and the growth and maintenance of lean body mass. 7) Under certain circumstances, specific amino acid supplements, such as branched-chain amino acids (BCAA's), may improve exercise performance and recovery from exercise.</p

Descriptive Analysis of a Baseline Concussion Battery Among U.S. Service Academy Members: Results from the Concussion Assessment, Research, and Education (CARE) Consortium

Introduction The prevalence and possible long-term consequences of concussion remain an increasing concern to the U.S. military, particularly as it pertains to maintaining a medically ready force. Baseline testing is being used both in the civilian and military domains to assess concussion injury and recovery. Accurate interpretation of these baseline assessments requires one to consider other influencing factors not related to concussion. To date, there is limited understanding, especially within the military, of what factors influence normative test performance. Given the significant physical and mental demands placed on service academy members (SAM), and their relatively high risk for concussion, it is important to describe demographics and normative profile of SAMs. Furthermore, the absence of available baseline normative data on female and non-varsity SAMs makes interpretation of post-injury assessments challenging. Understanding how individuals perform at baseline, given their unique individual characteristics (e.g., concussion history, sex, competition level), will inform post-concussion assessment and management. Thus, the primary aim of this manuscript is to characterize the SAM population and determine normative values on a concussion baseline testing battery. Materials and Methods All data were collected as part of the Concussion Assessment, Research and Education (CARE) Consortium. The baseline test battery included a post-concussion symptom checklist (Sport Concussion Assessment Tool (SCAT), psychological health screening inventory (Brief Symptom Inventory (BSI-18) and neurocognitive evaluation (ImPACT), Balance Error Scoring System (BESS), and Standardized Assessment of Concussion (SAC). Linear regression models were used to examine differences across sexes, competition levels, and varsity contact levels while controlling for academy, freshman status, race, and previous concussion. Zero inflated negative binomial models estimated symptom scores due to the high frequency of zero scores. Results Significant, but small, sex effects were observed on the ImPACT visual memory task. While, females performed worse than males (p < 0.0001, pη2 = 0.01), these differences were small and not larger than the effects of the covariates. A similar pattern was observed for competition level on the SAC. There was a small, but significant difference across competition level. SAMs participating in varsity athletics did significantly worse on the SAC compared to SAMs participating in club or intramural athletics (all p’s < 0.001, η2 = 0.01). When examining symptom reporting, males were more than two times as likely to report zero symptoms on the SCAT or BSI-18. Intramural SAMs had the highest number of symptoms and severity compared to varsity SAMs (p < 0.0001, Cohen’s d < 0.2). Contact level was not associated with SCAT or BSI-18 symptoms among varsity SAMs. Notably, the significant differences across competition level on SCAT and BSI-18 were sub-clinical and had small effect sizes. Conclusion The current analyses provide the first baseline concussion battery normative data among SAMs. While statistically significant differences may be observed on baseline tests, the effect sizes for competition and contact levels are very small, indicating that differences are likely not clinically meaningful at baseline. Identifying baseline differences and significant covariates is important for future concussion-related analyses to inform concussion evaluations for all athlete levels

Fitting quadrics with a Bayesian prior

Quadrics are a compact mathematical formulation for a range of primitive surfaces. A problem arises when there are not enough data-points to compute the model but knowledge of the shape is available. This paper presents a method for fitting a quadric with a Bayesian prior. We use a matrix normal prior in order to favour ellipsoids on ambiguous data. The results show the algorithm to cope well when there are few points in the point cloud, competing with contemporary techniques in the area

Co-ingestion of carbohydrate with branched-chain amino acids or L-leucine does not preferentially increase serum IGF-1 and expression of myogenic-related genes in response to a single bout of resistance exercise

This study determined if the co-ingestion of carbohydrate (CHO) with branched-chain amino acids (BCAA) or L-leucine (LEU) preferentially affected serum IGF-1 and the expression of myogenic-related genes in response to resistance exercise (RE). Forty one, college-age males were randomly assigned to 1 of 4 groups: CHO, CHO-BCAA, CHO-LEU, or placebo (PLC). Resistance exercise consisted of 4 sets of leg press and leg extension at 80% 1RM. Supplements were ingested peri-exercise, and venous blood and muscle biopsies were obtained pre-exercise (PRE), and at 30, 120, and 360 min post-exercise. Serum IGF-1 was determined with ELISA, and skeletal muscle mRNA expression of myostatin, ActRIIB, p21kip, p27kip, CDK2, cyclin B1, cyclin D1, Myo-D, myogenin, MRF-4, and myf5 was determined using real-time PCR. Results were determined with two-way ANOVA for serum IGF-1 and two-way MANOVA for mRNA expression. Serum IGF-1 in CHO and CHO+BCAA was greater than PLC (p \u3c 0.05) but was not affected by RE (p \u3e 0.05). Significant differences were detected between groups for myostatin, ActIIB, MyoD, and myf5 mRNA expression showing CHO to be significantly different than CHO+BCAA, CHO+LEU, and PLC (p \u3c 0.05). At 30, 120 and 360 min post-exercise, p21cip was significantly less than PRE, whereas cyclin D1 was greater than PRE at 120 and 360 min post-exercise (p \u3c 0.05). The co-ingestion of CHO with either BCAA or L-leucine in conjunction with RE had no preferential effect on serum IGF-1 or pre-translational markers indicative of myogenesis

Doing our work better, together: a relationship-based approach to defining the quality improvement agenda in trauma care

Article presents a study conducted at Gold Coast University Hospital that aimed to define and improve relational aspects of trauma care and facilitate co-creation of targeted interventions designed to improve team relationships and performance

Identifying 'avoidable harm' in family practice: A RAND/UCLA Appropriateness Method consensus study

BackgroundHealth care-related harm is an internationally recognized threat to public health. The United Kingdom’s national health services demonstrate that upwards of 90% of health care encounters can be delivered in ambulatory settings. Other countries are transitioning to more family practice-based health care systems, and efforts to understand avoidable harm in these settings is needed.MethodsWe developed 100 scenarios reflecting a range of diseases and informed by the World Health Organization definition of ‘significant harm’. Scenarios included different types of patient safety incidents occurring by commission and omission, demonstrated variation in timeliness of intervention, and conditions where evidence-based guidelines are available or absent. We conducted a two-round RAND / UCLA Appropriateness Method consensus study with a panel of family practitioners in England to define “avoidable harm” within family practice. Panelists rated their perceptions of avoidability for each scenario. We ran a k-means cluster analysis of avoidability ratings.ResultsPanelists reached consensus for 95 out of 100 scenarios. The panel agreed avoidable harm occurs when a patient safety incident could have been probably, or totally, avoided by the timely intervention of a health care professional in family practice (e.g. investigations, treatment) and / or an administrative process (e.g. referrals, alerts in electronic health records, procedures for following up results) in accordance with accepted evidence-based practice and clinical governance. Fifty-four scenarios were deemed avoidable, whilst 31 scenarios were rated unavoidable and reflected outcomes deemed inevitable regardless of family practice intervention. Scenarios with low avoidability ratings (1 s or 2 s) were not represented by the categories that were used to generate scenarios, whereas scenarios with high avoidability ratings (7 s 8 s or 9 s) were represented by these a priori categories.DiscussionThe findings from this RAND/UCLA Appropriateness Method study define the characteristics and conditions that can be used to standardize measurement of outcomes for primary care patient safety.ConclusionWe have developed a definition of avoidable harm that has potential for researchers and practitioners to apply across primary care settings, and bolster international efforts to design interventions to target avoidable patient safety incidents that cause the most significant harm to patients