Overcoming Lot-to-Lot Variability in Protein Activity Using Epitope-Specific Calibration-Free Concentration Analysis.

Concentration determination is a fundamental hallmark of protein reagent characterization, providing a means to ensure reproducibility and unify measurements from various assays. However, lot-to-lot differences in protein activity often still occur, leading to uncertainty in the accuracy of downstream measurements. Here, we postulate that those differences are caused by a misrepresentation of the protein concentration as measured by traditional total protein techniques, which can include multiple types of inactive protein species. To overcome this, we developed a standardized method to quantify a protein's active concentration via calibration-free concentration analysis (CFCA). As a pilot study, we compare the biophysical and immunoassay responses from three batches of recombinant soluble lymphocyte-activation gene 3 (sLAG3), as defined by either their total or active concentrations. Defining the sLAG3 reagents by their assay-specific concentration improved consistency in reported kinetic binding parameters and decreased immunoassay lot-to-lot coefficients of variation (CVs) by over 600% compared to the total protein concentration. These findings suggest that the total concentration of a protein reagent may not be the ideal metric to correlate in-assay signals between lots, and by instead quantifying the concentrations of a reagent's assay-specific epitopes, CFCA may prove a useful tool in overcoming lot-to-lot variability.

Separation and Characterization of Plastic Waste Packaging Contaminated with Food Residues.

In this paper, we present the development of a novel processing technology to tackle hard-to-recycle plastic packaging waste contaminated with food residues. The proof-of-concept (POC) technology can effectively separate food residual amounts from plastic waste materials to a level acceptable for further re-use or recycling of the plastic packaging. To assess this technology, we have conducted spectroscopic, thermal, and calorimetric characterizations of the obtained fractions, such as cleaned mixed plastics (CMP), food waste with mixed plastics (FWMP), and a mixture of microplastics (MP). The analyses were carried out with the aid of Fourier-Transform Infrared spectroscopy (FT-IR), Thermo-Gravimetric Analysis (TGA), Microcone Combustion Calorimetry (MCC), and 'bomb' calorimetry. The highest ratio of CMP to FWMP and the lowest amount of MP were obtained utilizing 700 rpm blade rotational speed and 15 s residence time of contaminated plastics in a cutting mill chamber. The plastics were freed from food contamination by 93-97%, which highlights a strong potential of the POC as a solution for 'dry-cleaning' of similar wastes on a larger scale. The main components of the CMP fraction were low-density polyethylene (LDPE), polypropylene (PP), and polyethylene terephthalate (PET), which are recyclable plastics. The knowledge and understanding of thermal degradation behaviours and calorimetric attributes of separated fractions, determined in this study, are essential in informing the industrial players using pyrolysis as a technique for recycling plastics.

COVID-VU - ENT-UK national survey of flexible nasendoscopy in the upper aerodigestive tract amidst the COVID-19 pandemic.

BACKGROUND: Flexible nasendoscopy (FNE) is an invaluable multi-disciplinary tool for upper aerodigestive tract (UADT) examination. During the COVID-19 pandemic concerns were raised that FNE had the potential of generating aerosols resulting in human cross-contamination when performed on SARS-COV2 carriers. In the UK, and other European countries, national guidelines were issued restricting FNE to essential cases. We surveyed ENT-UK members and Royal College of Speech and Language Therapists (RCSLT) members to determine the impact of the COVID-19 pandemic (first peak) on FNE practice in the UK. METHODS: An observational internet-based survey constructed in accordance to the CHERRIES checklist and setup in SurveyMonkey of FNE practice amongst UK-based ENT surgeons and speech and language therapists in community clinics, the outpatient department, inpatient wards, ICU, emergency department and operating theatres (through the NHS and private sector) prior to, during and following the first COVID-19 wave in the UK. RESULTS: 314 responses collected (24% response rate), 82% from ENT clinicians, 17% from SLTs and 1% from other allied healthcare professionals. Overall, there has been a large reduction in the volume and indications for FNE during the first peak of the COVID-19 pandemic with limited recovery by mid-August 2020. Cancer and airway assessments were impacted less. A wide range of FNE protocols influenced by local factors are reported, varying in endoscope preference, Personal Protective Equipment (PPE) and sterilization methods. Where dedicated Aerosol Generating Procedure (AGP) rooms were unavailable, clinicians resorted to window opening and variable room "down-time" between patients. Endoscope preference reflected availability and user familiarity, ENT trainees favoring the use of single-use video endoscopes. CONCLUSION: Despite national guidance, local practice of FNE remains interrupted and highly variable in the UK. A collaborative inter-disciplinary approach is required to re-introduce FNE safely in volume across healthcare settings, re-establishing timely endoscopic diagnosis and pre-pandemic levels of patient care.

Seroprevalence of SARS-CoV-2 Antibodies in Children and Adults in St. Louis, Missouri, USA.

Reported coronavirus disease 2019 (COVID-19) case counts likely underestimate the true prevalence because mild or asymptomatic cases often go untested. Here, we use a sero-survey to estimate the seroprevalence of IgG antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the St. Louis, MO, metropolitan area in a symptom-independent manner. Five hundred three adult and 555 pediatric serum/plasma samples were collected from patients presenting to Barnes-Jewish Hospital or St. Louis Children's Hospital between 14 April 2020 and 12 May 2020. We developed protocols for in-house enzyme-linked immunosorbent assays (ELISAs) using spike and nucleoprotein and used the assays to estimate a seroprevalence rate based on our samples. Overall IgG seropositivity was estimated to be 1.71% (95% credible interval [CI], 0.04% to 3.38%) in pediatric samples and 3.11% (95% CI, 0.92% to 5.32%) in adult samples. Seropositivity was significantly lower in children under 5 years of age than in adults, but rates between adults and children aged 5 or older were similar. Of the 176 samples tested from children under 4 years of age, none were positive.IMPORTANCE This study determined the percentages of both children and adult samples from the greater St. Louis metropolitan area who had antibodies to SARS-CoV-2 in late April to early May 2020. Approximately 1.7 to 3.1% of the tested individuals had antibodies, indicating that they had previously been infected by SARS-CoV-2. These results demonstrate that the extent of infection was about 10 times greater than the number of confirmed cases at that time. Furthermore, it demonstrated that by 5 years of age, children were infected to an extent similar to that of adults.

A Single-Dose Intranasal ChAd Vaccine Protects Upper and Lower Respiratory Tracts against SARS-CoV-2.

The coronavirus disease 2019 pandemic has made deployment of an effective vaccine a global health priority. We evaluated the protective activity of a chimpanzee adenovirus-vectored vaccine encoding a prefusion stabilized spike protein (ChAd-SARS-CoV-2-S) in challenge studies with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and mice expressing the human angiotensin-converting enzyme 2 receptor. Intramuscular dosing of ChAd-SARS-CoV-2-S induces robust systemic humoral and cell-mediated immune responses and protects against lung infection, inflammation, and pathology but does not confer sterilizing immunity, as evidenced by detection of viral RNA and induction of anti-nucleoprotein antibodies after SARS-CoV-2 challenge. In contrast, a single intranasal dose of ChAd-SARS-CoV-2-S induces high levels of neutralizing antibodies, promotes systemic and mucosal immunoglobulin A (IgA) and T cell responses, and almost entirely prevents SARS-CoV-2 infection in both the upper and lower respiratory tracts. Intranasal administration of ChAd-SARS-CoV-2-S is a candidate for preventing SARS-CoV-2 infection and transmission and curtailing pandemic spread.

Replication-Competent Vesicular Stomatitis Virus Vaccine Vector Protects against SARS-CoV-2-Mediated Pathogenesis in Mice.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused millions of human infections, and an effective vaccine is critical to mitigate coronavirus-induced disease 2019 (COVID-19). Previously, we developed a replication-competent vesicular stomatitis virus (VSV) expressing a modified form of the SARS-CoV-2 spike gene in place of the native glycoprotein gene (VSV-eGFP-SARS-CoV-2). Here, we show that vaccination with VSV-eGFP-SARS-CoV-2 generates neutralizing immune responses and protects mice from SARS-CoV-2. Immunization of mice with VSV-eGFP-SARS-CoV-2 elicits high antibody titers that neutralize SARS-CoV-2 and target the receptor binding domain that engages human angiotensin-converting enzyme-2 (ACE2). Upon challenge with a human isolate of SARS-CoV-2, mice that expressed human ACE2 and were immunized with VSV-eGFP-SARS-CoV-2 show profoundly reduced viral infection and inflammation in the lung, indicating protection against pneumonia. Passive transfer of sera from VSV-eGFP-SARS-CoV-2-immunized animals also protects naive mice from SARS-CoV-2 challenge. These data support development of VSV-SARS-CoV-2 as an attenuated, replication-competent vaccine against SARS-CoV-2.

Replication-competent vesicular stomatitis virus vaccine vector protects against SARS-CoV-2-mediated pathogenesis.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused millions of human infections and hundreds of thousands of deaths. Accordingly, an effective vaccine is of critical importance in mitigating coronavirus induced disease 2019 (COVID-19) and curtailing the pandemic. We developed a replication-competent vesicular stomatitis virus (VSV)-based vaccine by introducing a modified form of the SARS-CoV-2 spike gene in place of the native glycoprotein gene (VSV-eGFP-SARS-CoV-2). Immunization of mice with VSV-eGFP-SARS-CoV-2 elicits high titers of antibodies that neutralize SARS-CoV-2 infection and target the receptor binding domain that engages human angiotensin converting enzyme-2 (ACE2). Upon challenge with a human isolate of SARS-CoV-2, mice expressing human ACE2 and immunized with VSV-eGFP-SARS-CoV-2 show profoundly reduced viral infection and inflammation in the lung indicating protection against pneumonia. Finally, passive transfer of sera from VSV-eGFP-SARS-CoV-2-immunized animals protects naïve mice from SARS-CoV-2 challenge. These data support development of VSV-eGFP-SARS-CoV-2 as an attenuated, replication-competent vaccine against SARS-CoV-2.

Molluscum contagiosum virus MC80 sabotages MHC-I antigen presentation by targeting tapasin for ER-associated degradation.

The human specific poxvirus molluscum contagiosum virus (MCV) produces skin lesions that can persist with minimal inflammation, suggesting that the virus has developed robust immune evasion strategies. However, investigations into the underlying mechanisms of MCV pathogenesis have been hindered by the lack of a model system to propagate the virus. Herein we demonstrate that MCV-encoded MC80 can disrupt MHC-I antigen presentation in human and mouse cells. MC80 shares moderate sequence-similarity with MHC-I and we find that it associates with components of the peptide-loading complex. Expression of MC80 results in ER-retention of host MHC-I and thereby reduced cell surface presentation. MC80 accomplishes this by engaging tapasin via its luminal domain, targeting it for ubiquitination and ER-associated degradation in a process dependent on the MC80 transmembrane region and cytoplasmic tail. Tapasin degradation is accompanied by a loss of TAP, which limits MHC-I access to cytosolic peptides. Our findings reveal a unique mechanism by which MCV undermines adaptive immune surveillance.

Viral MHCI inhibition evades tissue-resident memory T cell formation and responses.

Tissue-resident memory CD8+ T cells (TRMs) confer rapid protection and immunity against viral infections. Many viruses have evolved mechanisms to inhibit MHCI presentation in order to evade CD8+ T cells, suggesting that these mechanisms may also apply to TRM-mediated protection. However, the effects of viral MHCI inhibition on the function and generation of TRMs is unclear. Herein, we demonstrate that viral MHCI inhibition reduces the abundance of CD4+ and CD8+ TRMs, but its effects on the local microenvironment compensate to promote antigen-specific CD8+ TRM formation. Unexpectedly, local cognate antigen enhances CD8+ TRM development even in the context of viral MHCI inhibition and CD8+ T cell evasion, strongly suggesting a role for in situ cross-presentation in local antigen-driven TRM differentiation. However, local cognate antigen is not required for CD8+ TRM maintenance. We also show that viral MHCI inhibition efficiently evades CD8+ TRM effector functions. These findings indicate that viral evasion of MHCI antigen presentation has consequences on the development and response of antiviral TRMs.

3-Dimensional fasciectomy: A highly efficacious common ground approach to Dupuytren's surgery.

BACKGROUND: Numerous Dupuytren's fasciectomy techniques have been described, each associated with unique surgical challenges, complications and recurrence rates. We describe a common ground surgical approach to Dupuytren's disease; 3-dimensional fasciectomy (3DF). 3DF aims to address the potential contributors to the high recurrence rate of Dupuytren's disease and unite current limited fasciectomy practice that varies considerably between surgeons. METHODS: We describe the 3DF principles; raising thin skin flaps (addressing dermal involvement), excising diseased palmar fascia with a 3-5 mm clearance margin (treating highly locally recurrent conditions) and excising the vertical septae of Legueu and Juvara (providing deep clearance, hence addressing all potentially involved pathological tissue). The surgical outcomes between traditional limited fasciectomy (LF) and 3DF are compared. RESULTS: From the 786 operations included (n=585), postoperative recurrence rates were significantly lower for the 3DF group (2/145, 1.4%) than the LF group (72/641, 11.2%) (P=0.001), and the time to recurrence was significantly longer (5.0±0 years vs. 4.0±0.2 years; P<0.0001). With recurrence excluded, there were no differences between the postoperative complication rates for 3DF (5/145, 3.5%) and LF (41/641, 6.4%) (P=0.4). CONCLUSIONS: Our results suggest that 3DF leads to lower recurrence rates and a longer disease-free period for patients, without increasing complications. 3DF provides a safe, efficacious, common ground surgical approach in the treatment of Dupuytren's flexion deformity.

Management of Patients With High Baseline Hip Fracture Risk by FRAX Reduces Hip Fractures-A Post Hoc Analysis of the SCOOP Study.

The Screening for Osteoporosis in Older Women for the Prevention of Fracture (SCOOP) study was a community-based screening intervention in women aged 70 to 85 years in the United Kingdom. In the screening arm, licensed osteoporosis treatments were recommended in women identified to be at high risk of hip fracture using the FRAX risk assessment tool (including bone mineral density measurement). In the control arm, standard care was provided. Screening led to a 28% reduction in hip fractures over 5 years. In this planned post hoc analysis, we wished to examine for interactions between screening effectiveness on fracture outcome (any, osteoporotic, and hip fractures) on the one hand and baseline FRAX 10-year probability of hip fracture on the other. All analyses were conducted on an intention-to-treat basis, based on the group to which women were randomized, irrespective of whether screening was completed. Of 12,483 eligible participants, 6233 women were randomized to screening, with treatment recommended in 898 (14.4%). No evidence of an effect or interaction was observed for the outcomes of any fracture or osteoporotic fracture. In the screening arm, 54 fewer hip fractures were observed than in the control arm (164 versus 218, 2.6% versus 3.5%), and commensurate with treatment being targeted to those at highest hip fracture risk, the effect on hip fracture increased with baseline FRAX hip fracture probability (p = 0.021 for interaction); for example, at the 10th percentile of baseline FRAX hip probability (2.6%), there was no evidence that hip fractures were reduced (hazard ratio [HR] = 0.93; 95% confidence interval [CI] 0.71 to 1.23), but at the 90th percentile (16.6%), there was a 33% reduction (HR = 0.67; 95% CI 0.53 to 0.84). Prior fracture and parental history of hip fracture positively influenced screening effectiveness on hip fracture risk. We conclude that women at high risk of hip fracture based on FRAX probability are responsive to appropriate osteoporosis management. © 2018 American Society for Bone and Mineral Research.

Screening in the community to reduce fractures in older women (SCOOP): a randomised controlled trial.

BACKGROUND: Despite effective assessment methods and medications targeting osteoporosis and related fractures, screening for fracture risk is not currently advocated in the UK. We tested whether a community-based screening intervention could reduce fractures in older women. METHODS: We did a two-arm randomised controlled trial in women aged 70-85 years to compare a screening programme using the Fracture Risk Assessment Tool (FRAX) with usual management. Women were recruited from 100 general practitioner (GP) practices in seven regions of the UK: Birmingham, Bristol, Manchester, Norwich, Sheffield, Southampton, and York. We excluded women who were currently on prescription anti-osteoporotic drugs and any individuals deemed to be unsuitable to enter a research study (eg, known dementia, terminally ill, or recently bereaved). The primary outcome was the proportion of individuals who had one or more osteoporosis-related fractures over a 5-year period. In the screening group, treatment was recommended in women identified to be at high risk of hip fracture, according to the FRAX 10-year hip fracture probability. Prespecified secondary outcomes were the proportions of participants who had at least one hip fracture, any clinical fracture, or mortality; and the effect of screening on anxiety and health-related quality of life. This trial is registered with the International Standard Randomised Controlled Trial registry, number ISRCTN 55814835. FINDINGS: 12 483 eligible women were identified and participated in the trial, and 6233 women randomly assigned to the screening group between April 15, 2008, and July 2, 2009. Treatment was recommended in 898 (14%) of 6233 women. Use of osteoporosis medication was higher at the end of year 1 in the screening group compared with controls (15% vs 4%), with uptake particularly high (78% at 6 months) in the screening high-risk subgroup. Screening did not reduce the primary outcome of incidence of all osteoporosis-related fractures (hazard ratio [HR] 0·94, 95% CI 0·85-1·03, p=0·178), nor the overall incidence of all clinical fractures (0·94, 0·86-1·03, p=0·183), but screening reduced the incidence of hip fractures (0·72, 0·59-0·89, p=0·002). There was no evidence of differences in mortality, anxiety levels, or quality of life. INTERPRETATION: Systematic, community-based screening programme of fracture risk in older women in the UK is feasible, and could be effective in reducing hip fractures. FUNDING: Arthritis Research UK and Medical Research Council.

Quantification of Lipid Filtration and the Effects on Cerebral Injury During Cardiopulmonary Bypass.

BACKGROUND: Lipid microemboli (LME) are formed in pericardial suction blood which, when returned to the cardiopulmonary bypass (CPB) circuit, can pass through filter materials and are returned to the arterial cannula. LME have been observed to enter all major organs and have been associated with small capillary arteriolar dilatations in the brains of patients who have died after CPB. However, a causal relationship showing correlation between LME and organ dysfunction has not been demonstrated, or whether removal of LME results in improved organ function. METHODS: A prospective, single center, randomized controlled trial examined 30 patients (15 per group) undergoing coronary artery bypass grafting using CPB with or without a lipid-depleting filter. The effects of LME filtration on neurocognitive injury were assessed using neuron-specific enolase (NSE). RESULTS: The study group showed a significant reduction in LME after filtration of the pericardial suction blood (p < 0.001), whereas the control group exhibited a significant rise in LME (p < 0.001). There was a significant reduction in peak NSE release (p = 0.013) and significant attenuation throughout the postoperative period (p = 0.002). Correlation and regression analyses showed a significant relationship between the number of LME post-CPB and peak NSE release (r = 0.42, p = 0.02). CONCLUSIONS: Several methods of LME filtration have been proposed, but none provided a suitable, efficacious method for use within the clinical setting. The RemoweLL CPB system removes significant numbers of LME from the cardiotomy suction. Furthermore, LME correlate to the release of a known marker of neurologic injury.

A Murine Herpesvirus Closely Related to Ubiquitous Human Herpesviruses Causes T-Cell Depletion.

The human roseoloviruses human herpesvirus 6A (HHV-6A), HHV-6B, and HHV-7 comprise the Roseolovirus genus of the human Betaherpesvirinae subfamily. Infections with these viruses have been implicated in many diseases; however, it has been challenging to establish infections with roseoloviruses as direct drivers of pathology, because they are nearly ubiquitous and display species-specific tropism. Furthermore, controlled study of infection has been hampered by the lack of experimental models, and until now, a mouse roseolovirus has not been identified. Herein we describe a virus that causes severe thymic necrosis in neonatal mice, characterized by a loss of CD4+ T cells. These phenotypes resemble those caused by the previously described mouse thymic virus (MTV), a putative herpesvirus that has not been molecularly characterized. By next-generation sequencing of infected tissue homogenates, we assembled a contiguous 174-kb genome sequence containing 128 unique predicted open reading frames (ORFs), many of which were most closely related to herpesvirus genes. Moreover, the structure of the virus genome and phylogenetic analysis of multiple genes strongly suggested that this virus is a betaherpesvirus more closely related to the roseoloviruses, HHV-6A, HHV-6B, and HHV-7, than to another murine betaherpesvirus, mouse cytomegalovirus (MCMV). As such, we have named this virus murine roseolovirus (MRV) because these data strongly suggest that MRV is a mouse homolog of HHV-6A, HHV-6B, and HHV-7.IMPORTANCE Herein we describe the complete genome sequence of a novel murine herpesvirus. By sequence and phylogenetic analyses, we show that it is a betaherpesvirus most closely related to the roseoloviruses, human herpesviruses 6A, 6B, and 7. These data combined with physiological similarities with human roseoloviruses collectively suggest that this virus is a murine roseolovirus (MRV), the first definitively described rodent roseolovirus, to our knowledge. Many biological and clinical ramifications of roseolovirus infection in humans have been hypothesized, but studies showing definitive causative relationships between infection and disease susceptibility are lacking. Here we show that MRV infects the thymus and causes T-cell depletion, suggesting that other roseoloviruses may have similar properties.

Does home oxygen therapy (HOT) in addition to standard care reduce disease severity and improve symptoms in people with chronic heart failure? A randomised trial of home oxygen therapy for patients with chronic heart failure.

BACKGROUND: Home oxygen therapy (HOT) is commonly used for patients with severe chronic heart failure (CHF) who have intractable breathlessness. There is no trial evidence to support its use. OBJECTIVES: To detect whether or not there was a quality-of-life benefit from HOT given as long-term oxygen therapy (LTOT) for at least 15 hours per day in the home, including overnight hours, compared with best medical therapy (BMT) in patients with severely symptomatic CHF. DESIGN: A pragmatic, two-arm, randomised controlled trial recruiting patients with severe CHF. It included a linked qualitative substudy to assess the views of patients using home oxygen, and a free-standing substudy to assess the haemodynamic effects of acute oxygen administration. SETTING: Heart failure outpatient clinics in hospital or the community, in a range of urban and rural settings. PARTICIPANTS: Patients had to have heart failure from any aetiology, New York Heart Association (NYHA) class III/IV symptoms, at least moderate left ventricular systolic dysfunction, and be receiving maximally tolerated medical management. Patients were excluded if they had had a cardiac resynchronisation therapy device implanted within the past 3 months, chronic obstructive pulmonary disease fulfilling the criteria for LTOT or malignant disease that would impair survival or were using a device or medication that would impede their ability to use LTOT. INTERVENTIONS: Patients received BMT and were randomised (unblinded) to open-label LTOT, prescribed for 15 hours per day including overnight hours, or no oxygen therapy. MAIN OUTCOME MEASURES: The primary end point was quality of life as measured by the Minnesota Living with Heart Failure (MLwHF) questionnaire score at 6 months. Secondary outcomes included assessing the effect of LTOT on patient symptoms and disease severity, and assessing its acceptability to patients and carers. RESULTS: Between April 2012 and February 2014, 114 patients were randomised to receive either LTOT or BMT. The mean age was 72.3 years [standard deviation (SD) 11.3 years] and 70% were male. Ischaemic heart disease was the cause of heart failure in 84%; 95% were in NYHA class III; the mean left ventricular ejection fraction was 27.8%; and the median N-terminal pro-B-type natriuretic hormone was 2203 ng/l. The primary analysis used a covariance pattern mixed model which included patients only if they provided data for all baseline covariates adjusted for in the model and outcome data for at least one post-randomisation time point (n = 102: intervention, n = 51; control, n = 51). There was no difference in the MLwHF questionnaire score at 6 months between the two arms [at baseline the mean score was 54.0 (SD 18.4) for LTOT and 54.0 (SD 17.9) for BMT; at 6 months the mean score was 48.1 (SD 18.5) for LTOT and 49.0 (SD 20.2) for BMT; adjusted mean difference -0.10, 95% confidence interval (CI) -6.88 to 6.69; p = 0.98]. At 3 months, the adjusted mean MLwHF questionnaire score was lower in the LTOT group (-5.47, 95% CI -10.54 to -0.41; p = 0.03) and breathlessness scores improved, although the effect did not persist to 6 months. There was no effect of LTOT on any secondary measure. There was a greater number of deaths in the BMT arm (n = 12 vs. n = 6). Adherence was poor, with only 11% of patients reporting using the oxygen as prescribed. CONCLUSIONS: Although the study was significantly underpowered, HOT prescribed for 15 hours per day and subsequently used for a mean of 5.4 hours per day has no impact on quality of life as measured by the MLwHF questionnaire score at 6 months. Suggestions for future research include (1) a trial of patients with severe heart failure randomised to have emergency oxygen supply in the house, supplied by cylinders rather than an oxygen concentrator, powered to detect a reduction in admissions to hospital, and (2) a study of bed-bound patients with heart failure who are in the last few weeks of life, powered to detect changes in symptom severity. TRIAL REGISTRATION: Current Controlled Trials ISRCTN60260702. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 75. See the NIHR Journals Library website for further project information.

Specifying the target difference in the primary outcome for a randomised controlled trial: guidance for researchers.

BACKGROUND: Central to the design of a randomised controlled trial is the calculation of the number of participants needed. This is typically achieved by specifying a target difference and calculating the corresponding sample size, which provides reassurance that the trial will have the required statistical power (at the planned statistical significance level) to identify whether a difference of a particular magnitude exists. Beyond pure statistical or scientific concerns, it is ethically imperative that an appropriate number of participants should be recruited. Despite the critical role of the target difference for the primary outcome in the design of randomised controlled trials, its determination has received surprisingly little attention. This article provides guidance on the specification of the target difference for the primary outcome in a sample size calculation for a two parallel group randomised controlled trial with a superiority question. METHODS: This work was part of the DELTA (Difference ELicitation in TriAls) project. Draft guidance was developed by the project steering and advisory groups utilising the results of the systematic review and surveys. Findings were circulated and presented to members of the combined group at a face-to-face meeting, along with a proposed outline of the guidance document structure, containing recommendations and reporting items for a trial protocol and report. The guidance and was subsequently drafted and circulated for further comment before finalisation. RESULTS: Guidance on specification of a target difference in the primary outcome for a two group parallel randomised controlled trial was produced. Additionally, a list of reporting items for protocols and trial reports was generated. CONCLUSIONS: Specification of the target difference for the primary outcome is a key component of a randomized controlled trial sample size calculation. There is a need for better justification of the target difference and reporting of its specification.

An Intrinsically Disordered Peptide from Ebola Virus VP35 Controls Viral RNA Synthesis by Modulating Nucleoprotein-RNA Interactions.

During viral RNA synthesis, Ebola virus (EBOV) nucleoprotein (NP) alternates between an RNA-template-bound form and a template-free form to provide the viral polymerase access to the RNA template. In addition, newly synthesized NP must be prevented from indiscriminately binding to noncognate RNAs. Here, we investigate the molecular bases for these critical processes. We identify an intrinsically disordered peptide derived from EBOV VP35 (NPBP, residues 20-48) that binds NP with high affinity and specificity, inhibits NP oligomerization, and releases RNA from NP-RNA complexes in vitro. The structure of the NPBP/ΔNPNTD complex, solved to 3.7 Å resolution, reveals how NPBP peptide occludes a large surface area that is important for NP-NP and NP-RNA interactions and for viral RNA synthesis. Together, our results identify a highly conserved viral interface that is important for EBOV replication and can be targeted for therapeutic development.

Reversing paclitaxel resistance in ovarian cancer cells via inhibition of the ABCB1 expressing side population.

The majority of deaths in ovarian cancer are caused by recurrent metastatic disease which is usually multidrug resistant. This progression has been hypothesised to be due in part to the presence of cancer stem cells, a subset of cells which are capable of self-renewal and are able to survive chemotherapy and migrate to distant sites. Side population (SP) cells, identified by the efflux of the DNA-binding dye Hoechst 33342 through ATP-binding cassette (ABC) transporters, are a known adult stem cell group and have been suggested as a cancer stem cell in various cancers. Despite the identification of SP cells in cancer cell lines and patient samples, little attention has been paid to the identification of specific ABC transporters within this cell fraction which efflux Hoechst dye and thus may facilitate drug resistance. In this study, we demonstrate that SP cells can be detected in both ovarian cancer cell lines and ascitic fluid samples, and these SP cells possess stem cell and drug resistance properties. We show that ABCB1 is the functioning ABC transporter in ovarian cancer cell lines, and expression of ABCB1 is associated with a paclitaxel-resistant phenotype. Moreover, silencing of ABCB1 using a specific morpholino oligonucleotide results in an inhibition of the SP phenotype and a sensitising of ovarian cancer cell lines to paclitaxel. ABCB1 should therefore be considered as a therapeutic target in ovarian cancer.

Assessing methods to specify the target difference for a randomised controlled trial: DELTA (Difference ELicitation in TriAls) review.

BACKGROUND: The randomised controlled trial (RCT) is widely considered to be the gold standard study for comparing the effectiveness of health interventions. Central to the design and validity of a RCT is a calculation of the number of participants needed (the sample size). The value used to determine the sample size can be considered the 'target difference'. From both a scientific and an ethical standpoint, selecting an appropriate target difference is of crucial importance. Determination of the target difference, as opposed to statistical approaches to calculating the sample size, has been greatly neglected though a variety of approaches have been proposed the current state of the evidence is unclear. OBJECTIVES: The aim was to provide an overview of the current evidence regarding specifying the target difference in a RCT sample size calculation. The specific objectives were to conduct a systematic review of methods for specifying a target difference; to evaluate current practice by surveying triallists; to develop guidance on specifying the target difference in a RCT; and to identify future research needs. DESIGN: The biomedical and social science databases searched were MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Methodology Register, PsycINFO, Science Citation Index, EconLit, Education Resources Information Center (ERIC) and Scopus for in-press publications. All were searched from 1966 or the earliest date of the database coverage and searches were undertaken between November 2010 and January 2011. There were three interlinked components: (1) systematic review of methods for specifying a target difference for RCTs - a comprehensive search strategy involving an electronic literature search of biomedical and some non-biomedical databases and clinical trials textbooks was carried out; (2) identification of current trial practice using two surveys of triallists - members of the Society for Clinical Trials (SCT) were invited to complete an online survey and respondents were asked about their awareness and use of, and willingness to recommend, methods; one individual per triallist group [UK Clinical Research Collaboration (UKCRC)-registered Clinical Trials Units (CTUs), Medical Research Council (MRC) UK Hubs for Trials Methodology Research and National Institute for Health Research (NIHR) UK Research Design Services (RDS)] was invited to complete a survey; (3) production of a structured guidance document to aid the design of future trials - the draft guidance was developed utilising the results of the systematic review and surveys by the project steering and advisory groups. SETTING: Methodological review incorporating electronic searches, review of books and guidelines, two surveys of experts (membership of an international society and UK- and Ireland-based triallists) and development of guidance. PARTICIPANTS: The two surveys were sent out to membership of the SCT and UK- and Ireland-based triallists. INTERVENTIONS: The review focused on methods for specifying the target difference in a RCT. It was not restricted to any type of intervention or condition. MAIN OUTCOME MEASURES: Methods for specifying the target difference for a RCT were considered. RESULTS: The search identified 11,485 potentially relevant studies. In total, 1434 were selected for full-text assessment and 777 were included in the review. Seven methods to specify the target difference for a RCT were identified - anchor, distribution, health economic, opinion-seeking, pilot study, review of evidence base (RoEB) and standardised effect size (SES) - each having important variations in implementation. A total of 216 of the included studies used more than one method. A total of 180 (15%) responses to the SCT survey were received, representing 13 countries. Awareness of methods ranged from 38% (n =69) for the health economic method to 90% (n =162) for the pilot study. Of the 61 surveys sent out to UK triallist groups, 34 (56%) responses were received. Awareness ranged from 97% (n =33) for the RoEB and pilot study methods to only 41% (n =14) for the distribution method. Based on the most recent trial, all bar three groups (91%, n =30) used a formal method. Guidance was developed on the use of each method and the reporting of the sample size calculation in a trial protocol and results paper. CONCLUSIONS: There is a clear need for greater use of formal methods to determine the target difference and better reporting of its specification. Raising the standard of RCT sample size calculations and the corresponding reporting of them would aid health professionals, patients, researchers and funders in judging the strength of the evidence and ensuring better use of scarce resources. FUNDING: The Medical Research Council UK and the National Institute for Health Research Joint Methodology Research programme.