619 research outputs found
Functional characterization of recombinant chloroplast signal recognition particle
The signal recognition particle (SRP) is a ubiquitous system for the targeting of membrane and secreted proteins. The chloroplast SRP (cpSRP) is unique among SRPs in that it possesses no RNA and is functional in post-translational as well as co-translational targeting. We have expressed and purified the two components of the Arabidopsis thaliana chloroplast signal recognition particle (cpSRP) involved in post-translational transport: cpSRP54 and the chloroplast-specific protein, cpSRP43. Recombinant cpSRP supports the efficient in vitro insertion of pea preLhcb1 into isolated thylakoid membranes. Recombinant cpSRP is a stable heterodimer with a molecular mass of approximately 100 kDa as determined by analytical ultracentrifugation, gel filtration analysis, and dynamic light scattering. The interactions of the components of the recombinant heterodimer and pea preLhcb1 were probed using an immobilized peptide library (pepscan) approach. These data confirm two previously reported interactions with the L18 region and the third transmembrane helix of Lhcb1 and suggest that the interface of the cpSRP43 and cpSRP54 proteins is involved in substrate binding. Additionally, cpSRP components are shown to recognize peptides from the cleavable, N-terminal chloroplast transit peptide of preLhcb1. The interaction of cpSRP43 with cpSRP54 was probed in a similar experiment with a peptide library representing cpSPR54. The C terminus of cpSRP54 is essential for the formation of the stable cpSRP complex and cpSPR43 interacts with distinct regions of the M domain of cpSRP54.</p
An occupational therapy intervention for residents with stroke related disabilities in UK care homes (OTCH): cluster randomised controlled trial
Objective To evaluate the clinical efficacy of an established programme of occupational therapy in maintaining functional activity and reducing further health risks from inactivity in care home residents living with stroke sequelae.
Design Pragmatic, parallel group, cluster randomised controlled trial.
Setting 228 care homes (>10 beds each), both with and without the provision of nursing care, local to 11 trial administrative centres across the United Kingdom.
Participants 1042 care home residents with a history of stroke or transient ischaemic attack, including those with language and cognitive impairments, not receiving end of life care. 114 homes (n=568 residents, 64% from homes providing nursing care) were allocated to the intervention arm and 114 homes (n=474 residents, 65% from homes providing nursing care) to standard care (control arm). Participating care homes were randomised between May 2010 and March 2012.
Intervention Targeted three month programme of occupational therapy, delivered by qualified occupational therapists and assistants, involving patient centred goal setting, education of care home staff, and adaptations to the environment.
Main outcome measures Primary outcome at the participant level: scores on the Barthel index of activities of daily living at three months post-randomisation. Secondary outcome measures at the participant level: Barthel index scores at six and 12 months post-randomisation, and scores on the Rivermead mobility index, geriatric depression scale-15, and EuroQol EQ-5D-3L questionnaire, at all time points.
Results 64% of the participants were women and 93% were white, with a mean age of 82.9 years. Baseline characteristics were similar between groups for all measures, personal characteristics, and diagnostic tests. Overall, 2538 occupational therapy visits were made to 498 participants in the intervention arm (mean 5.1 visits per participant). No adverse events attributable to the intervention were recorded. 162 (11%) died before the primary outcome time point, and 313 (30%) died over the 12 months of the trial. The primary outcome measure did not differ significantly between the treatment arms. The adjusted mean difference in Barthel index score at three months was 0.19 points higher in the intervention arm (95% confidence interval â0.33 to 0.70, P=0.48). Secondary outcome measures also showed no significant differences at all time points.
Conclusions This large phase III study provided no evidence of benefit for the provision of a routine occupational therapy service, including staff training, for care home residents living with stroke related disabilities. The established three month individualised course of occupational therapy targeting stroke related disabilities did not have an impact on measures of functional activity, mobility, mood, or health related quality of life, at all observational time points. Providing and targeting ameliorative care in this clinically complex population requires alternative strategies
The effects of childbirth on the pelvic-floor
Basically, vaginal delivery is associated with the risk of pelvic floor damage. The pelvic floor sequelae of childbirth includes anal incontinence, urinary incontinence and pelvic organ prolapse. Pathophysiology, incidence and risk factors for the development of the respective problems are reviewed. Where possible, recommendations for reducing the risk of pelvic floor damage are given
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The Optical Lightpipe as a High-Bandwidth Fusion Diagnostic
A recent series of experiments at the University of Rochester Laboratory for Laser Energetics OMEGA facility studied the feasibility of using radiation-to-light converters and high bandwidth optical signal transmission to remote recording devices as an alternate nuclear diagnostic method. A prototype system included a radiation-to-light converter, a multiple-section light pipe consisting of stainless steel tubes with polished interiors and turning mirrors, and a streak camera or photomultiplier/digitizer combination for signal recording. Several different radiation-to-light converters (scintillators, glasses, plastics, and pressurized CO{sub 2}) performed well and produced predictable optical emissions. The lightpipe transmitted high-bandwidth optical signals to the recording stations. Data were recorded with the streak camera, the photomultiplier/digitizer, and with both recorders simultaneously
Generalizability of Blood Pressure Lowering Trials to Older Patients: CrossâSectional Analysis
BACKGROUND/OBJECTIVES: Randomized controlled trials are used to inform clinical guidelines on the management of hypertension in older adults, but it is unclear to what extent these trials represent the general population attending routine clinical practice. This study aimed to define the proportion and characteristics of patients eligible for hypertension trials conducted in older people.
DESIGN: Crossâsectional study.
SETTING: A total of 24 general practices in England.
PARTICIPANTS: Anonymized electronic health record data from all individuals aged 80 and older.
MEASUREMENTS: Descriptive statistics were used to define the proportion and characteristics of patients eligible for two previous medication intensification trials (HYVET, SPRINT) and one medication reduction trial (OPTiMISE). A logistic regression model was constructed to estimate predictors of eligibility for each trial.
RESULTS: Of 15,376 patients identified, 268 (1.7%; 95% confidence interval [CI] = 1.5â2.0%), 5,290 (34.4%; 95%CI = 33.7â35.2%), and 3,940 (25.6%; 95%CI = 24.9â26.3%) were eligible for the HYVET, SPRINT, and OPTiMISE trials, respectively. Between 5.6% and 30.7% of exclusions from each trial were due to eligibility criteria excluding those with high or uncontrolled blood pressure. Frailty (odds ratio [OR] = .44; 95%CI = .36â.54 [OPTiMISE]), cardiovascular polypharmacy (OR = .61; 95%CI = .55â.68 [SPRINT]) and multimorbidity (OR = .72; 95%CI = .64â.82 [SPRINT]) were associated with a lower likelihood of being eligible for one or more of the trials.
CONCLUSION: A possible unintended consequence of blood pressure criteria used by trials attempting to answer different primary questions is that for many older patients, no trial evidence exists to inform treatment decisions in routine practice. Caution should be exercised when applying results from existing trials to patients with frailty or multimorbidity
Phase I trial of WEE1 inhibition with chemotherapy and radiotherapy as adjuvant treatment, and a window of opportunity trial with cisplatin in patients with head and neck cancer: the WISTERIA trial protocol.
INTRODUCTION:Patients with head and neck squamous cell carcinoma with locally advanced disease often require multimodality treatment with surgery, radiotherapy and/or chemotherapy. Adjuvant radiotherapy with concurrent chemotherapy is offered to patients with high-risk pathological features postsurgery. While cure rates are improved, overall survival remains suboptimal and treatment has a significant negative impact on quality of life.Cell cycle checkpoint kinase inhibition is a promising method to selectively potentiate the therapeutic effects of chemoradiation. Our hypothesis is that combining chemoradiation with a WEE1 inhibitor will affect the biological response to DNA damage caused by cisplatin and radiation, thereby enhancing clinical outcomes, without increased toxicity. This trial explores the associated effect of WEE1 kinase inhibitor adavosertib (AZD1775). METHODS AND ANALYSIS:This phase I dose-finding, open-label, multicentre trial aims to determine the highest safe dose of AZD1775 in combination with cisplatin chemotherapy preoperatively (group A) as a window of opportunity trial, and in combination with postoperative cisplatin-based chemoradiation (group B).Modified time-to-event continual reassessment method will determine the recommended dose, recruiting up to 21 patients per group. Primary outcomes are recommended doses with predefined target dose-limiting toxicity probabilities of 25% monitored up to 42 days (group A), and 30% monitored up to 12 weeks (group B). Secondary outcomes are disease-free survival times (groups A and B). Exploratory objectives are evaluation of pharmacodynamic (PD) effects, identification and correlation of potential biomarkers with PD markers of DNA damage, determine rate of resection status and surgical complications for group A; and quality of life in group B. ETHICS AND DISSEMINATION:Research Ethics Committee, Edgbaston, West Midlands (REC reference 16/WM/0501) initial approval received on 18/01/2017. Results will be disseminated via peer-reviewed publication and presentation at international conferences. TRIAL REGISTRATION NUMBER:ISRCTN76291951 and NCT03028766
Cumulative Complexity: A qualitative analysis of patientsâ experiences of living with heart failure with preserved ejection fraction
Abstract Aims To investigate how Heart Failure with preserved Ejection Fraction, within the context of limited clinical services, impacts upon patientsâ lives. Methods & Results Secondary thematic analysis informed by the Cumulative Complexity Model (CCM), of interview transcripts from 77 people diagnosed with HFpEF and their carers. Four themes corresponding to the core concepts of workload, capacity, access and outcome described in the CCM were generated. Theme 1: Shouldering a Heavy Workload, described the many tasks expected of people living with HFpEF. Theme 2: The Multiple Threats to Capacity described how patients and carers strived to engage with this work, but were often faced with multiple threats such as symptoms and mobility limitations. Deficient Illness Identity (Theme 3) reflects how HFpEF either was not recognised or was perceived as a more benign form of HF and therefore afforded less importance or priority. These themes contributed to a range of negative physical, social and psychological outcomes and the perception of loss of control described in Theme 4: Spiraling Complexity. Conclusions The constellation of HFpEF, multimorbidity and aging creates many demands that people with HFpEF are expected to manage. Concurrently, the same syndromes threaten their ability to physically enact this work. Patients' recollections of their interactions with health professionals suggest there is widespread misunderstanding of HFpEF, which can prohibit access to care that could potentially reduce or prevent deterioration. </jats:sec
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