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This study introduces the prostate cancer linear energy transfer sensitivity index (PCLSI) as a novel method to predict relative biological effectiveness (RBE) in prostate cancer using linear energy transfer (LET) in proton therapy based on screening for DNA repair mutations.
Materials and Methods:
Five prostate cancer cell lines with DNA repair mutations known to cause sensitivity to LET and DNA repair inhibitors were examined using published data. Relative Du145 LET sensitivity data were leveraged to deduce the LET equivalent of olaparib doses. The PCLSI model was built using three of the prostate cancer cell lines (LNCaP, 22Rv1 and Du145) with DNA mutation frequency from patient cohorts. The PCLSI model was compared against two established RBE models, McNamara and McMahon, for LET-optimized prostate cancer treatment plans.
Results:
The PCLSI model relies on the presence of eight DNA repair mutations: AR, ATM, BRCA1, BRCA2, CDH1, ETV1, PTEN and TP53, which are most likely to predict increased LET sensitivity and RBE in proton therapy. In the LET-optimized plan, the PCLSI model indicates that prostate cancer cells with these DNA repair mutations are more sensitive to increased LET than the McNamara and McMahon RBE models, with expected RBE increases ranging from 11%–33% at 2keV/µm.
Conclusions:
The PCLSI model predicts increasing RBE as a function of LET in the presence of certain genetic mutations. The integration of LET-optimized proton therapy and genetic mutation profiling could be a significant step toward the use of individualized medicine to improve outcomes using RBE escalation without the potential toxicity of physical dose escalation.
Task planning and its effect on the complexity of second language (L2) written production have been studied extensively. However, the results of these studies are inconclusive, and at times contradictory, potentially as a result of variation in metrics of linguistic complexity. This study is an extension of earlier research syntheses and quantitative meta-analyses on the effects of planning on oral and written L2 production. It examines the identification and selection of linguistic complexity metrics in previous research on planning and its subsequent effects on the linguistic complexity of written L2 production. This research-focused synthesis of studies surveys construct definitions and operational definitions of linguistic complexity in the research domain and provides an overview of rationales for metric selection in the included studies. Methodological implications for future research are discussed in light of the findings.
Objective. The efficacy of individualized, community-based physical activity as an adjunctive smoking cessation treatment to enhance long-term smoking cessation rates was evaluated for the Lifestyle Enhancement Program (LEAP). Methods. The study was a two-arm, parallel-group, randomized controlled trial. All participants (n = 392) received cessation counseling and a nicotine patch and were randomized to physical activity (n = 199; YMCA membership and personalized exercise programming from a health coach) or an equal contact frequency wellness curriculum (n = 193). Physical activity treatment was individualized and flexible (with each participant selecting types of activities and intensity levels and being encouraged to exercise at the YMCA and at home, as well as to use “lifestyle” activity). The primary outcome (biochemically verified prolonged abstinence at 7-weeks (end of treatment) and 6- and 12-months postcessation) and secondary outcomes (7-day point prevalent tobacco abstinence (PPA), total minutes per week of leisure time physical activity and strength training) were assessed at baseline, 7 weeks, 6 months, and 12 months. Results. Prolonged abstinence in the physical activity and wellness groups was 19.6% and 25.4%, respectively, at 7-weeks, 15.1% and 16.6% at 6-months, and 14.1% and 17.1% at 12 months (all between-group P values >0.18). Similarly, PPA rates did not differ significantly between groups at any follow-up. Change from baseline leisure-time activity plus strength training increased significantly in the physical activity group at 7 weeks (P = 0.04). Across treatment groups, an increase in the number of minutes per week in strength training from baseline to 7 weeks predicted prolonged abstinence at 12 months (P ≤ 0.001). Further analyses revealed that social support, fewer years smoked, and less temptation to smoke were associated with prolonged abstinence over 12 months in both groups. Conclusions. Community-based physical activity programming, delivered as adjunctive treatment with behavioral/pharmacological cessation treatment, did not improve long-term quit rates compared to adjunctive wellness counseling plus behavioral/pharmacological cessation treatment. This trial is registered with https://beta.clinicaltrials.gov/study/NCT00403312, registration no. NCT00403312.
South Africa has embarked on major health policy reform to deliver universal health coverage through the establishment of National Health Insurance (NHI). The aim is to improve access, remove financial barriers to care, and enhance care quality. Health technology assessment (HTA) is explicitly identified in the proposed NHI legislation and will have a prominent role in informing decisions about adoption and access to health interventions and technologies. The specific arrangements and approach to HTA in support of this legislation are yet to be determined. Although there is currently no formal national HTA institution in South Africa, there are several processes in both the public and private healthcare sectors that use elements of HTA to varying extents to inform access and resource allocation decisions. Institutions performing HTAs or related activities in South Africa include the National and Provincial Departments of Health, National Treasury, National Health Laboratory Service, Council for Medical Schemes, medical scheme administrators, managed care organizations, academic or research institutions, clinical societies and associations, pharmaceutical and devices companies, private consultancies, and private sector hospital groups. Existing fragmented HTA processes should coordinate and conform to a standardized, fit-for-purpose process and structure that can usefully inform priority setting under NHI and for other decision makers. This transformation will require comprehensive and inclusive planning with dedicated funding and regulation, and provision of strong oversight mechanisms and leadership.
OBJECTIVES/GOALS: Neonatal hypoxic-ischemic encephalopathy (HIE) is an acute neurologic syndrome where decreased blood flow and oxygen to the brain causes acute and chronic brain dysfunction. The only proven neuroprotective intervention for HIE is hypothermia treatment started within 6 hours of birth and 50% of survivors have long-term deficits. METHODS/STUDY POPULATION: Pre-clinical adult stroke studies demonstrated that vagus nerve stimulation (VNS) has anti-inflammatory effects and attenuates brain damage. Transcutaneous auricular VNS (taVNS) is safe and feasible in infants and may improve the motor skill of bottle feeding. We hypothesize that a combined hypothermia-taVNS treatment shortly after HIE birth will have neuroprotective effects, improve motor function, attenuate infarct volume inflammation compared to hypothermia alone. The HIE model includes ligation of the right common carotid artery in postnatal day 7 (P7) rats followed by 90min hypoxia (8% oxygen) and 2hr hypothermia. taVNS or sham taVNS was administered using a bipolar electrode placed on the auricular concha region for 30min, [30sec trains, 0.5msec duration, 20Hz frequency, followed by 4.5min breaks] RESULTS/ANTICIPATED RESULTS: Experimental groups include +HIE/+taVNS, +HIE/-taVNS, and -HIE/-taVNS. To assess motor function, grasping reflex and forelimb grip strength tasks were assessed prior to surgery through P10. Infarct volume was assessed at 72h after injury by staining coronal sections with cresyl-violet. Thirty-four rat pups underwent surgery with an 8.82% mortality rate. taVNS was well tolerated by the P7 rats when delivered below perceptual threshold (0.4-1.1mA). There was no difference in elementary motor function or infarct volume between any group. DISCUSSION/SIGNIFICANCE: Future studies will include 2.5hr hypoxia for a more severe brain injury and a -HIE/+taVNS control group. These initial pre-clinical studies in neonates are important in determining whether taVNS may translate as a treatment to improve outcomes after neonatal HIE.
Rapid whole genome sequencing (rapid WGS) is a powerful diagnostic tool that is becoming increasingly practical for widespread clinical use. However, protocols for its use are challenging to implement. A significant obstacle to clinical adoption is that laboratory certification requires an initial research development phase, which is constrained by regulations from returning results. Regulations preventing return of results have ethical implications in cases which might impact patient outcomes. Here, we describe our experience with the development of a rapid WGS research protocol, that balanced the requirements for laboratory-validated test development with the ethical needs of clinically relevant return of results.
To determine the utility of the Sofia SARS rapid antigen fluorescent immunoassay (FIA) to guide hospital-bed placement of patients being admitted through the emergency department (ED).
Design:
Cross-sectional analysis of a clinical quality improvement study.
Setting:
This study was conducted in 2 community hospitals in Maryland from September 21, 2020, to December 3, 2020. In total, 2,887 patients simultaneously received the Sofia SARS rapid antigen FIA and SARS-CoV-2 RT-PCR assays on admission through the ED.
Methods:
Rapid antigen results and symptom assessment guided initial patient placement while confirmatory RT-PCR was pending. The sensitivity, specificity, positive predictive values, and negative predictive values of the rapid antigen assay were calculated relative to RT-PCR, overall and separately for symptomatic and asymptomatic patients. Assay sensitivity was compared to RT-PCR cycle threshold (Ct) values. Assay turnaround times were compared. Clinical characteristics of RT-PCR–positive patients and potential exposures from false-negative antigen assays were evaluated.
Results:
For all patients, overall agreement was 97.9%; sensitivity was 76.6% (95% confidence interval [CI], 71%–82%), and specificity was 99.7% (95% CI, 99%–100%). We detected no differences in performance between asymptomatic and symptomatic individuals. As RT-PCR Ct increased, the sensitivity of the antigen assay decreased. The mean turnaround time for the antigen assay was 1.2 hours (95% CI, 1.0–1.3) and for RT-PCR it was 20.1 hours (95% CI, 18.9–40.3) (P < .001). No transmission from antigen-negative/RT-PCR–positive patients was identified.
Conclusions:
Although not a replacement for RT-PCR for detection of all SARS-CoV-2 infections, the Sofia SARS antigen FIA has clinical utility for potential initial timely patient placement.
The study of planning in second language (L2) writing research is heavily influenced by two research domains: (a) early research on cognition in first language (L1) composing processes and (b) second language acquisition (SLA) research. The first research domain has been instrumental in determining the specific systems and processes involved in composing and has led to widely accepted models of L1 writing (Bereiter & Scardamalia, 1987*; Flower & Hayes, 1980*; Hayes, 1996, 2012) as well as a widely accepted model of the interaction between working memory and L1 writing systems (Kellogg, 1996*; Kellogg, Whiteford, Turner, Cahill, & Mertens, 2013). The influence of these early studies is still felt in process approaches to composition instruction commonly implemented in L1 and L2 writing classes. The second research domain—SLA and more specifically task-based language teaching/learning—has come to view planning as a feature of task complexity that can be manipulated to facilitate the production of language that is complex (syntactically and/or lexically), accurate, and/or fluent (Robinson, 2011*; Skehan, 1998*; Skehan & Foster, 2001). This research timeline traces the study of planning in L2 writing in each of these domains by reviewing key L1 and L2 writing research over the last 30-plus years and by highlighting each study's findings. Prior to presenting the timeline, the following sections provide backgrounds in each of the domains noted above and situate planning within those domains.