Relationship of performance on the sensory organization test to landing characteristics

Background: Jump landing tasks have been used to assess landing characteristics and require significant sensorimotor feedback to maintain functional joint stability (FJS) throughout the task. Postural stability (PS) also requires significant sensorimotor feedback and control and would seemingly involve similar sensory feedback pathways. However, previous literature clarifying the relationship between these two processes, maintaining FJS and PS, is limited. Participants: 80 Special Tactics Operators Methods: PS was assessed using the Sensory Organization Test (SOT). SOT variables included: Composite, Somatosensory, Visual, Vestibular, and Preference scores. Landing characteristics were assessed using motion analysis and during a double-legged (DLSJ) and single-legged (SLSJ) stop jump task. Pearson’s correlation coefficients were calculated to assess the relationship between SOT scores and landing characteristics (α<.05) Results: For the DLSJ, significant correlations were found between: Composite and peak posterior ground reaction forces (-.257), Vestibular and peak knee abduction moment (-.237), and Preference and initial contact hip flexion (-.297), peak hip flexion (-.249). For the SLSJ, significant correlations were found between: Somatosensory and peak vertical ground reaction forces (-.246); Preference and initial contact hip flexion (-.295), peak hip flexion (-.262). Conclusions: The results indicate that the SOT may not be a sensitive enough tool to assess sensorimotor control in a healthy, athletic population

Initial steps towards an evidence-based classification system for golfers with a physical impairment

Purpose: The present narrative review aims to make a first step towards an evidence-based classification system in handigolf following the International Paralympic Committee (IPC). It intends to create a conceptual framework of classification for handigolf and an agenda for future research. Method: Pubmed was searched on three themes: “Classification in Paralympic sports”, “Performance determining factors in golf” and “Impact of impairments on golf performance”. IPC-regulations were gathered on the IPC-website and their official publications. Results: In developing a classification system conform IPC-regulations, the main challenge is to identify the activity limitation caused by the impairment, not influenced by training, talent or motivation. Timing, accuracy and control, work per joint, range of motion, balance and flexibility are important performance determining factors in abled-bodied golf and should be considered when determining activity limitations in handigolf. Only five articles on handigolf were found, mainly addressing the asymmetric golf movement. Based on the present review, a conceptual framework for classification was developed, while a future research agenda was designated. The conceptual framework presents factors that are essential for sports performance categorized under “technology”, “interface” and “athlete characteristics”. It also includes impairment related factors essential for determining eligibility and classification. Ideally, measures to be used during classification need to be resistant against training, natural development of the athlete’s talent and motivational changes. Conclusions: The conceptual framework and a multidimensional scientific research agenda will support further development of the knowledge base required for an evidence-based classification in handigolf, including multi-level analysis of player statistics, experimental analyses of biomechanics and modeling studies.Implications for Rehabilitation The main challenge in developing an evidence-based classification system conform IPC-regulations is defining eligibility criteria and sport classes based on activity limitation caused by only the impairment and not affected by training, talent and motivation. It is expected that a transparent classification system, a lively competition and admission to the Paralympic program will further promote participation in disabled golf. Timing, accuracy and control, work per joint, range of motion, balance and flexibility are of greater importance for golf performance in able-bodied golfers and expected to be of interest to incorporate in classification for handigolf. Side and level of amputation influence activity limitation in the asymmetric golf movement, and should be incorporated in classification. The proposed conceptual framework is fundamental to the research agenda that must further generate the knowledge-base to determine activity limitations caused by different impairments in handigolf and may serve as a guideline for other Paralympic sports in the development of evidence-based classification

A Q-methodology study of flare help-seeking behaviours and different experiences of daily life in rheumatoid arthritis

© 2014 Lin et al.; licensee BioMed Central Ltd. Background: Previous studies have not addressed rheumatoid arthritis (RA) patients' help-seeking behaviours for RA flares, and only one small qualitative study has addressed how patients experience daily life on current treatment regimes. Thus, this study aims to identify clusters of opinion related to RA patients' experiences of daily life on current treatments, and their help-seeking behaviours for RA flares. Methods: Using Q-methodology (a methodology using qualitative and quantitative methods to sort people according to subjective experience), two separate studies were conducted with the same sample of RA patients (mean age 55, 73% female). Thirty participants sorted 39 statements about daily life (Q-study 1) and 29 participants separately sorted 23 statements about flare help-seeking (Q-study 2). Data were examined using Q-factor analysis. Results: Daily life with RA (Q-study 1): Three factors relating to the experience of living with RA were extracted and explained. Patients belonging to Factor A (mean age 62, 86% female) use effective self-management techniques to control the daily impact of RA. Those in Factor B (mean age 55, 75% male) struggle to self-manage and cope. Whilst patients in Factor C (mean age 42, 100% female) prioritise life responsibilities over their RA, reporting less impact. Flare help-seeking (Q-study 2): Two factors explaining the experience of flare help-seeking (unrelated to the factors from Q-study 1) were extracted and explained. Factor X (68.8% on biologics) reported seeking help quickly, believing the medical team is there to help. Factor Y (0% on biologics) delay help-seeking, concerned about wasting the rheumatologist's time, believing they should manage alone. All participants agreed they sought help due to intense pain and persistent, unmanageable symptoms. Conclusions: Patients with different characteristics appear to manage RA life in different ways and men may struggle more than women. Whilst all patients are prompted to seek help by persistent, unmanageable symptoms, some delay help-seeking. Further research is needed to quantify the severity of daily symptoms, the level of symptoms needed for patients to define themselves as in flare and to understand the support needs of RA men

Altering α-dystroglycan receptor affinity of LCMV pseudotyped lentivirus yields unique cell and tissue tropism

BACKGROUND: The envelope glycoprotein of lymphocytic choriomeningitis virus (LCMV) can efficiently pseudotype lentiviral vectors. Some strains of LCMV exploit high affinity interactions with α-dystroglycan (α-DG) to bind to cell surfaces and subsequently fuse in low pH endosomes. LCMV strains with low α-DG affinity utilize an unknown receptor and display unique tissue tropisms. We pseudotyped non-primate feline immunodeficiency virus (FIV) vectors using LCMV derived glycoproteins with high or low affinity to α-DG and evaluated their properties in vitro and in vivo. METHODS: We pseudotyped FIV with the LCMV WE54 strain envelope glycoprotein and also engineered a point mutation in the WE54 envelope glycoprotein (L260F) to diminish α-DG affinity and direct binding to alternate receptors. We hypothesized that this change would alter in vivo tissue tropism and enhance gene transfer to neonatal animals. RESULTS: In mice, hepatic α- and β-DG expression was greatest at the late gestational and neonatal time points. When displayed on the surface of the FIV lentivirus the WE54 L260F mutant glycoprotein bound weakly to immobilized α-DG. Additionally, LCMV WE54 pseudotyped FIV vector transduction was neutralized by pre-incubation with soluble α-DG, while the mutant glycoprotein pseudotyped vector was not. In vivo gene transfer in adult mice with either envelope yielded low transduction efficiencies in hepatocytes following intravenous delivery. In marked contrast, neonatal gene transfer with the LCMV envelopes, and notably with the FIV-L260F vector, conferred abundant liver and lower level cardiomyocyte transduction as detected by luciferase assays, bioluminescent imaging, and β-galactosidase staining. CONCLUSIONS: These results suggest that a developmentally regulated receptor for LCMV is expressed abundantly in neonatal mice. LCMV pseudotyped vectors may have applications for neonatal gene transfer. ABBREVIATIONS: Armstrong 53b (Arm53b); baculovirus Autographa californica GP64 (GP64); charge-coupled device (CCD); dystroglycan (DG); feline immunodeficiency virus (FIV); glycoprotein precursor (GP-C); firefly luciferase (Luc); lymphocytic choriomeningitis virus (LCMV); nuclear targeted β-galactosidase (ntLacZ); optical density (OD); PBS/0.1% (w/v) Tween-20 (PBST); relative light units (RLU); Rous sarcoma virus (RSV); transducing units per milliliter (TU/ml); vesicular stomatitis virus (VSV-G); wheat germ agglutinin (WGA); 50% reduction in binding (C50)

Knee stability assessment on anterior cruciate ligament injury: Clinical and biomechanical approaches

Anterior cruciate ligament (ACL) injury is common in knee joint accounting for 40% of sports injury. ACL injury leads to knee instability, therefore, understanding knee stability assessments would be useful for diagnosis of ACL injury, comparison between operation treatments and establishing return-to-sport standard. This article firstly introduces a management model for ACL injury and the contribution of knee stability assessment to the corresponding stages of the model. Secondly, standard clinical examination, intra-operative stability measurement and motion analysis for functional assessment are reviewed. Orthopaedic surgeons and scientists with related background are encouraged to understand knee biomechanics and stability assessment for ACL injury patients

Altering α-dystroglycan receptor affinity of LCMV pseudotyped lentivirus yields unique cell and tissue tropism

BACKGROUND: The envelope glycoprotein of lymphocytic choriomeningitis virus (LCMV) can efficiently pseudotype lentiviral vectors. Some strains of LCMV exploit high affinity interactions with α-dystroglycan (α-DG) to bind to cell surfaces and subsequently fuse in low pH endosomes. LCMV strains with low α-DG affinity utilize an unknown receptor and display unique tissue tropisms. We pseudotyped non-primate feline immunodeficiency virus (FIV) vectors using LCMV derived glycoproteins with high or low affinity to α-DG and evaluated their properties in vitro and in vivo. METHODS: We pseudotyped FIV with the LCMV WE54 strain envelope glycoprotein and also engineered a point mutation in the WE54 envelope glycoprotein (L260F) to diminish α-DG affinity and direct binding to alternate receptors. We hypothesized that this change would alter in vivo tissue tropism and enhance gene transfer to neonatal animals. RESULTS: In mice, hepatic α- and β-DG expression was greatest at the late gestational and neonatal time points. When displayed on the surface of the FIV lentivirus the WE54 L260F mutant glycoprotein bound weakly to immobilized α-DG. Additionally, LCMV WE54 pseudotyped FIV vector transduction was neutralized by pre-incubation with soluble α-DG, while the mutant glycoprotein pseudotyped vector was not. In vivo gene transfer in adult mice with either envelope yielded low transduction efficiencies in hepatocytes following intravenous delivery. In marked contrast, neonatal gene transfer with the LCMV envelopes, and notably with the FIV-L260F vector, conferred abundant liver and lower level cardiomyocyte transduction as detected by luciferase assays, bioluminescent imaging, and β-galactosidase staining. CONCLUSIONS: These results suggest that a developmentally regulated receptor for LCMV is expressed abundantly in neonatal mice. LCMV pseudotyped vectors may have applications for neonatal gene transfer. ABBREVIATIONS: Armstrong 53b (Arm53b); baculovirus Autographa californica GP64 (GP64); charge-coupled device (CCD); dystroglycan (DG); feline immunodeficiency virus (FIV); glycoprotein precursor (GP-C); firefly luciferase (Luc); lymphocytic choriomeningitis virus (LCMV); nuclear targeted β-galactosidase (ntLacZ); optical density (OD); PBS/0.1% (w/v) Tween-20 (PBST); relative light units (RLU); Rous sarcoma virus (RSV); transducing units per milliliter (TU/ml); vesicular stomatitis virus (VSV-G); wheat germ agglutinin (WGA); 50% reduction in binding (C50)

The aromatase inhibitor letrozole and inhibitors of insulin-like growth factor I receptor synergistically induce apoptosis in in vitro models of estrogen-dependent breast cancer

INTRODUCTION: Endocrine-dependent, estrogen receptor positive breast cancer cells proliferate in response to estrogens, synthesized by the cytochrome p450 aromatase enzyme. Letrozole is a potent nonsteroidal aromatase inhibitor that is registered for the treatment of postmenopausal women with advanced metastatic breast cancers and in the neoadjuvant, early, and extended adjuvant indications. Because crosstalk exists between estrogen receptor and insulin-like growth factor I receptor (IGF-IR), the effect of combining a selective IGF-IR inhibitor (NVP-AEW541) with letrozole was assessed in two independent in vitro models of estrogen-dependent breast cancer. METHODS: MCF7 and T47D cells stably expressing aromatase (MCF7/Aro and T47D/Aro) were used as in vitro models of aromatase-driven breast cancer. The role of the IGF-IR pathway in breast cancer cells stimulated only by 17ß-estradiol or androstenedione was assessed by proliferation assays. The combination of letrozole and NVP-AEW541 was assessed for synergy in inhibiting cell proliferation using Chou-Talalay derived equations. Finally, combination or single agent effects on proliferation and apoptosis were assessed using proliferation assays, flow cytometry, and immunoblotting. RESULTS: Both MCF7 and T47D cells, as well as MCF7/Aro and T47D/Aro, exhibited sensitivity to inhibition of 17ß-estradiol dependent proliferation by NVP-AEW541. Letrozole combined with NVP-AEW541 synergistically inhibited androstenedione-dependent proliferation in aromatase-expressing cells with combination index values of 0.6 or less. Synergistic combination effects correlated with higher levels of apoptosis as compared with cells treated with the single agent alone. Treatment with either agent also appeared to inhibit IGF-IR signalling via phosphoinositide 3-kinase. Notably, IGF-IR inhibition had limited effect on estrogen-dependent proliferation in the cell lines, but was clearly required for survival, suggesting that the combination of letrozole and IGF-IR inhibition sensitizes cells to apoptosis. CONCLUSION: Inhibition of the IGF-IR pathway and aromatase was synergistic in two independent estrogen-dependent in vitro models of breast cancer. Moreover, synergism of NVP-AEW541 and letrozole correlated with induction of apoptosis, but not cell cycle arrest, in the cell lines tested. Combination of IGF-IR inhibitors and letrozole may hold promise for the treatment of patients with estrogen-dependent breast cancers