Molecular characterisation of squamous cell carcinoma antigen recognised by T-cells 3, an adaptor protein of ubiquitin specific protease 15

The deubiquitinating enzyme USP15, a member of the USP family, reverses the process of ubiquitination thereby altering the fate of a plethora of substrates. As such, USP15 has been implicated in a numerous important cellular pathways including cell cycle progression, transcriptional modification and DNA damage repair. The spliceosomal subunit recycling protein SART3 has been shown to bind to USP15 enhancing its deubiquitination of histone H2B thereby providing histone dimers for reassembly during subsequent rounds of transcription and splicing. Furthermore SART3 has also been shown to bind to USP4, a close homologue of USP15. In addition to this histone chaperone activity, SART3 primarily functions by mediating the re-annealing of the U4 and U6 snRNPs to facilitate consequent rounds of splicing in addition to its implication in several disease states including numerous cancer types and HIV through interactions with various cellular proteins. In this thesis ITC, ESI-MS, analytical size exclusion, X-ray crystallography, SAXS and pull-down assays are used to characterise the interaction between USP15 and SART3, solve the structure of the N-terminus of SART3 and identify novel binding partners of the USP15-SART3 complex. The structure of SART3’s N-terminus (residues 96-574) has been solved to 3.04Å, revealing that it is a homodimer comprised of a series of anti-parallel α-helices that form a shape reminiscent of a bowtie. This dimeric arrangement is retained in solution and can bind two molecules of USP15DU. The DU-finger of USP15 plays a pivotal role in co-ordinating the binding interaction with SART3, as small changes to this region can affect the nanomolar affinity interaction between USP15 and SART3. In addition the USP15-SART3 complex appears to interact with several cellular proteins which could have significant impact in several disease states

Electrocardiographic patch devices and contemporary wireless cardiac monitoring.

Cardiac electrophysiologic derangements often coexist with disorders of the circulatory system. Capturing and diagnosing arrhythmias and conduction system disease may lead to a change in diagnosis, clinical management and patient outcomes. Standard 12-lead electrocardiogram (ECG), Holter monitors and event recorders have served as useful diagnostic tools over the last few decades. However, their shortcomings are only recently being addressed by emerging technologies. With advances in device miniaturization and wireless technologies, and changing consumer expectations, wearable “on-body” ECG patch devices have evolved to meet contemporary needs. These devices are unobtrusive and easy to use, leading to increased device wear time and diagnostic yield. While becoming the standard for detecting arrhythmias and conduction system disorders in the outpatient setting where continuous ECG monitoring in the short to medium term (days to weeks) is indicated, these cardiac devices and related digital mobile health technologies are reshaping the clinician-patient interface with important implications for future healthcare delivery

A review of outcomes and modes of presentation following liner dissociation from Harris-Galante uncemented acetabular components

Purpose Dissociation of the polyethylene liner is a known failure mechanism of the Harris Galante I and II uncemented acetabular components. The outcomes of revision surgery for this indication and the influence of time to diagnosis are not well described. Methods We report a series of 29 cases revised due to this failure mechanism. The median time from primary to revision surgery was 13 years. Results At a median of 4 years follow-up, the mean OHS was 34 (range 6-48) but results were poorer (mean 29; range 6-45) when the diagnosis and revision was delayed compared to when it was not (mean 39; range 20-48). A large proportion of our patients (n = 14) presented with sudden onset of symptoms with or without trauma. Osteolysis was common in this series but the cup was well fixed in 20/29 cases. There was macroscopic damage to the shell in all cases. Conclusions In our experience, prompt revision of liner dissociation optimises outcomes in this group of patients and radiology reporting alone is not sufficient to identify these cases. </jats:sec

Reliability of a musculoskeletal profiling test battery in elite academy soccer players

The study aimed to quantify the measurement error / reliability of a musculoskeletal profiling test battery administered in young, elite academy soccer players, and to examine if the order in which the test battery was administered, and who it was administered by, influenced reliability. Players (n = 75; age 12–20 years; stature 1.47–1.95 m; body mass 36–89 kg) from U-12 to U-23 age groups were assigned to either: 1) intra-rater-fixed order; 2) intra-rater-non-fixed order; 3) inter-rater-fixed order; or, 4) inter-rater-non-fixed order groups. On two separate occasions separated by 3 to 7 days, 12 raters conducted a musculoskeletal profiling test battery comprising 10 tests (Supine Medial Hip Rotation, Supine Lateral Hip Rotation, Hamstring 90/90, Prone Medial Hip Rotation [degrees]; Combined Elevation, Thoracic Rotation, Weight-Bearing Dorsiflexion, Y-Balance [centimetres]; Beighton, Lumbar Quadrant [categorical]). The measurement error / reliability for tests measured in degrees and centimetres was evaluated using the intraclass correlation (relative reliability), coefficient of variation and ratio limits of agreement (absolute reliability). Intraclass correlations varied from 0.04 (“poor”) to 0.95 (“excellent”), coefficient of variation from 2.9 to 43.4%, and the ratio limits of agreement from 1.058 (*/÷ 1.020) to 2.026 (*/÷ 1.319) for the tests measured in degrees and centimetres. The intraclass correlation, coefficient of variation and ratio limits of agreement were smallest for five out of eight tests measured in degrees and centimetres when the tests were administered in an intra-rater-fixed test order. These findings emphasise that different testing methods, and the administration of a musculoskeletal profiling test battery using a less than optimal design, will influence measurement error and hence test reliability. These observations need to be considered when investigating musculoskeletal function and age, injury, training or asymmetry in young, elite academy soccer players

A review of biomarker and imaging monitoring to predict heart failure recovery

Heart failure is a clinical syndrome caused by structural cardiac abnormalities that lead to increased intracardiac pressures and decreased cardiac output. Following cardiovascular insult or direct myocardial injury, neurohormonal activation triggers hemodynamic changes and cardiac remodeling to preserve cardiac output. While initially adaptive, cardiac remodeling eventually causes pathologic changes in cardiac structure that often compromise cardiac function. Reverse remodeling is the regression of abnormal cardiac chamber geometry and function after myocardial injury. In recent years, several classes of therapeutics have been associated with greater likelihood of reverse remodeling. Heart failure recovery and heart failure remission, terms encompassing the clinical correlates of reverse remodeling, have been associated with improved survival in patients with heart failure with reduced ejection. As such, identifying predictors of heart failure recovery can have important implications for guiding clinical practice and therapeutic innovation. This review addresses the role of biomarkers and imaging monitoring in predicting structural, functional, and clinical recovery in patients with acute and chronic heart failure

A 15 to 17-year follow-up of the Kinemax total knee replacement

Background: There is a paucity of long-term data concerning the pre- and postoperative patient reported function of total knee replacement. The aim of this study was to determine the mortality, implant survivorship, patient reported function and satisfaction in a cohort of 114 patients, from a single centre, who received a Kinemax total knee replacement more than 15 years ago. Methods: Patients completed a questionnaire incorporating validated disease- and joint-specific scores, patient satisfaction and overall health preoperatively, at three months, one year, two years and a minimum of 15 years following surgery. NHS National Strategic Tracing Service, hospital and primary care records were used to establish mortality and for implant survivorship in deceased patients. Results: Forty five patients were alive at final follow-up. The survivorship of the cohort with revision of the TKR as the endpoint was 84%. Four cases were revised for wear, three for loosening and one for peri-prosthetic fracture. There was a significant improvement in WOMAC Pain, Function and Stiffness Scores, Oxford Knee Score and Self-Administered Patient Satisfaction Scale between pre-operative and all post-operative time points, although patient satisfaction had decreased significantly by the time of final follow-up. Conclusion: In this cohort, the Kinemax TKR showed survivorship of 84% at 16.3 years with functional scores demonstrating a high level of patient satisfaction at all follow-up time points

Case Report of Multiembolic Cerebrovascular Event Associated with Ramp Study Echocardiogram

The incidence of ramp test echocardiogram-associated embolic events in the setting of therapeutic anticoagulation is likely rare and has not been reported. We present such a case in a patient with a HeartMate II left ventricular assist device (LVAD) whose serial head computed tomography images, deteriorating clinical course, and the multiembolic nature of the event suggest causality. If the pretest probability of pump thrombosis in an individual LVAD patient is sufficiently high, the potential risks of performing a ramp study echocardiogram may not be warranted, even in the setting of adequate anticoagulation

Anti-erbB2 treatment induces cardiotoxicity by interfering with cell survival pathways

INTRODUCTION: Cardiac dysfunction is among the serious side effects of therapy with recombinant humanized anti-erbB2 monoclonal antibody. The antibody blocks ErbB-2, a receptor tyrosine kinase and co-receptor for other members of the ErbB and epidermal growth factor families, which is over-expressed on the surface of many malignant cells. ErbB-2 and its ligands neuregulin and ErbB-3/ErbB-4 are involved in survival and growth of cardiomyocytes in both postnatal and adult hearts, and therefore the drug may interrupt the correct functioning of the ErbB-2 pathway. METHODS: The effect of the rat-anti-erbB2 monoclonal antibody B-10 was studied in spontaneously beating primary myocyte cultures from rat neonatal hearts. Gene expression was determined by RT-PCR (reverse transcription polymerase chain reaction) and by rat stress-specific microarray analysis, protein levels by Western blot, cell contractility by video motion analysis, calcium transients by the FURA fluorescent method, and apoptosis using the TUNEL (terminal uridine nick-end labelling) assay. RESULTS: B-10 treatment induces significant changes in expression of 24 out of 207 stress genes analyzed using the microarray technique. Protein levels of ErbB-2, ErbB-3, ErbB-4 and neuregulin decreased after 1 day. However, both transcription and protein levels of ErbB-4 and gp130 increased several fold. Calreticulin and calsequestrin were overexpressed after three days, inducing a decrease in calcium transients, thereby influencing cell contractility. Apoptosis was induced in 20% cells after 24 hours. CONCLUSION: Blocking ErbB-2 in cultured rat cardiomyocytes leads to changes that may influence the cell cycle and affects genes involved in heart functions. B-10 inhibits pro-survival pathways and reduces cellular contractility. Thus, it is conceivable that this process may impair the stress response of the heart

Mitochondria-Specific Accumulation of Amyloid β Induces Mitochondrial Dysfunction Leading to Apoptotic Cell Death

Mitochondria are best known as the essential intracellular organelles that host the homeostasis required for cellular survival, but they also have relevance in diverse disease-related conditions, including Alzheimer's disease (AD). Amyloid β (Aβ) peptide is the key molecule in AD pathogenesis, and has been highlighted in the implication of mitochondrial abnormality during the disease progress. Neuronal exposure to Aβ impairs mitochondrial dynamics and function. Furthermore, mitochondrial Aβ accumulation has been detected in the AD brain. However, the underlying mechanism of how Aβ affects mitochondrial function remains uncertain, and it is questionable whether mitochondrial Aβ accumulation followed by mitochondrial dysfunction leads directly to neuronal toxicity. This study demonstrated that an exogenous Aβ1–42 treatment, when applied to the hippocampal cell line of mice (specifically HT22 cells), caused a deleterious alteration in mitochondria in both morphology and function. A clathrin-mediated endocytosis blocker rescued the exogenous Aβ1–42-mediated mitochondrial dysfunction. Furthermore, the mitochondria-targeted accumulation of Aβ1–42 in HT22 cells using Aβ1–42 with a mitochondria-targeting sequence induced the identical morphological alteration of mitochondria as that observed in the APP/PS AD mouse model and exogenous Aβ1–42-treated HT22 cells. In addition, subsequent mitochondrial dysfunctions were demonstrated in the mitochondria-specific Aβ1–42 accumulation model, which proved indistinguishable from the mitochondrial impairment induced by exogenous Aβ1–42-treated HT22 cells. Finally, cellular toxicity was directly induced by mitochondria-targeted Aβ1–42 accumulation, which mimics the apoptosis process in exogenous Aβ1–42-treated HT22 cells. Taken together, these results indicate that mitochondria-targeted Aβ1–42 accumulation is the necessary and sufficient condition for Aβ-mediated mitochondria impairments, and leads directly to cellular death rather than along with other Aβ-mediated signaling alterations