Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Baseline cardiovascular risk in subjects with type 2 diabetes and chronic kidney disease from the FLOW trial

Background

Patients with chronic kidney disease and type 2 diabetes (T2D) have a high risk of progression to kidney failure as well as cardiovascular (CV) events. It is established that glucagon-like peptide-1 receptor agonists (GLP-1RAs) improve glycaemic control and reduce body weight. Some CV outcomes trials have shown that GLP-1RAs reduce CV risk in people with T2D at high CV risk; for example, the SUSTAIN 6 trial demonstrated that the GLP-1RA semaglutide significantly lowered the rate of major CV events (CV death, non-fatal myocardial infarction and non-fatal stroke) versus placebo. Some trials have also indicated that GLP-1RAs reduce albuminuria and estimated glomerular filtration rate (eGFR) decline. Based on these previous results indicating potential kidney-protective effects, the FLOW trial (NCT03819153) is evaluating once-weekly, subcutaneous semaglutide 1.0 mg versus placebo on kidney- and CV-related outcomes in participants with T2D. We describe the baseline characteristics and the calculated CV risk of this patient population using the atherosclerotic CV disease (ASCVD) and second manifestations of arterial disease (SMART) risk calculators.

Methods

FLOW is an ongoing, multicentre, randomised, double-blind, parallel-group, event-driven, phase 3b trial, with participants randomised 1:1 to semaglutide or placebo, each in addition to standard of care. Recruitment is complete and 3,535 participants with T2D, an eGFR ≥25–≤75 mL/min/1.73 m2, and urine albumin-to-creatinine ratio ≥100–≤5,000 mg/g have been enrolled. The primary endpoint is time to first occurrence of a kidney composite that includes ≥50% persistent eGFR reduction, kidney failure (persistent eGFR <15 mL/min/1.73 m2 or initiation of chronic dialysis or kidney transplantation), and kidney-related death, or CV death. Key secondary outcomes include time to first occurrence of CV death, myocardial infarction or stroke.

Results

The baseline clinical characteristics and demographics are shown (Table 1). Median age was 68 years, 30% were female, mean diabetes duration was 17 years, and 98% had a history of hypertension. Overall, 52% of participants had a previous CV event. The calculated 10-year risk for ASCVD events in those without prior ASCVD was 31% in males and 18% in females, and in those with previous CV events was 37–56% in males and 35–53% in females depending on the type of CV disease reported in the calculator (Table 2).

Conclusions

The FLOW trial has completed enrolment. Based on the ASCVD and SMART risk calculators, the enrolled population has a substantial risk for adverse CV outcomes. Event ascertainment is ongoing, and the FLOW trial will provide evidence for the potential of semaglutide to improve kidney and CV outcomes in the T2D population.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Novo Nordisk

How well do polygenic risk scores identify men at high risk for prostate cancer? Systematic review and meta-analysis

OBJECTIVES

Genome-wide association studies have revealed over 200 genetic susceptibility loci for prostate cancer (PCa). By combining them, polygenic risk scores (PRS) can be generated to predict risk of PCa. We summarize the published evidence and conduct meta-analyses of PRS as a predictor of PCa risk in Caucasian men.

PATIENTS AND METHODS

Data were extracted from 59 studies, with 16 studies including 17 separate analyses used in the main meta-analysis with a total of 20,786 cases and 69,106 controls identified through a systematic search of ten databases. Random effects meta-analysis was used to obtain pooled estimates of area under the receiver-operating characteristic curve (AUC). Meta-regression was used to assess the impact of number of single-nucleotide polymorphisms (SNPs) incorporated in PRS on AUC. Heterogeneity is expressed as I² scores. Publication bias was evaluated using funnel plots and Egger tests.

RESULTS

The ability of PRS to identify men with PCa was modest (pooled AUC 0.63, 95% CI 0.62-0.64) with moderate consistency (I² 64%). Combining PRS with clinical variables increased the pooled AUC to 0.74 (0.68-0.81). Meta-regression showed only negligible increase in AUC for adding incremental SNPs. Despite moderate heterogeneity, publication bias was not evident.

CONCLUSION

Typically, PRS accuracy is comparable to PSA or family history with a pooled AUC value 0.63 indicating mediocre performance for PRS alone.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Microplastics and other anthropogenic particles in the surface waters of the Chesapeake Bay

Microplastics are a ubiquitous environmental contaminant whose distributions have been correlated with land-use and population density. Although there are numerous studies quantifying microplastics in the environment, local studies help inform sources, pathways, and policy. Here, we measure the concentration of microplastics in the surface waters across the Chesapeake Bay - the largest estuary in the USA. Thirty surface water samples from throughout the Chesapeake Bay were collected with a manta trawl. Samples were manually processed for microplastics and other anthropogenic particles. Fourier-transform infrared spectroscopy (FTIR) was used to determine the chemical composition of the particles. Higher concentrations were found near major cities and where larger rivers or tributaries met the Chesapeake Bay. Fragments, films, and fibres were the most common morphologies found, and polyethylene and polypropylene were the most common plastic types. These results can be used to inform mitigation strategies for microplastic pollution in the Chesapeake Bay region.

Production of relativistic electrons at subrelativistic laser intensities

Relativistic electron temperatures were measured from kilojoule, subrelativistic laser-plasma interactions. Experiments show an order of magnitude higher temperatures than expected from a ponderomotive scaling, where temperatures of up to 2.2 MeV were generated using an intensity of 1×10^{18}W/cm^{2}. Two-dimensional particle-in-cell simulations suggest that electrons gain superponderomotive energies by stochastic acceleration as they sample a large area of rapidly changing laser phase. We demonstrate that such high temperatures are possible from subrelativistic intensities by using lasers with long pulse durations and large spatial scales.

Prevalence of and factors associated with underdiagnosis of pediatric asthma in Batumi, Georgia

BACKGROUND AND OBJECTIVE

A recent survey in Batumi, Georgia showed a low prevalence of asthma in children (1.8%). A potential explanation is underdiagnosis of asthma. To investigate this, we conducted a follow up to the survey with the objective of estimating the level of childhood asthma underdiagnosis and to describe factors related to it.

METHODS

Subjects included 437 survey participants who had a history of asthma-like symptoms and no diagnosis of asthma. All children underwent clinical examination (spirometry, skin prick tests, FeNO measurement) to identify new cases of asthma. The distribution of host and environmental factors was compared between the group with newly identified asthma and a group of 59 children with previously known asthma (diagnosed asthma).

RESULTS

Clinical investigation identified 107 cases of undiagnosed asthma. The corrected asthma prevalence estimate was 5.1% (95%CI: 4.4%-5.9%) suggesting that 65% of asthma cases were undiagnosed. Compared to children with diagnosed asthma, children with undiagnosed asthma were younger (8.2±1.6 vs. 9.3±2.1; p=0.0005), had less frequent history of allergic disorders (38.3% vs. 64.4%; p=0.001), and a lower prevalence of parental asthma (1.8% vs. 8.4%; p=0.04). The groups did not differ in terms of environmental characteristics except for more exposure to passive smoking in the undiagnosed asthma group (p=0.01). Multivariate analysis confirmed results of simple analyses.

CONCLUSION

In Batumi, 65% of children with asthma remain undiagnosed. Older age of a child, coexisting allergic disorders, and parental asthma seem to facilitate diagnosis. Implementation of current diagnostic guidelines should improve diagnostic accuracy of pediatric asthma in Batumi.

Wound protectors for improved exposure in open hernia repair

INTRODUCTION

Achieving adequate surgical exposure is fundamental to good surgical practice. Traditionally, in the repair of ventral and open inguinal hernias, this has been accomplished with the aid of self-retaining retractors or by extending the incision length. We propose that using disposable wound protectors, surgical exposure will be improved for a given incision length in the repair of ventral and open inguinal hernias, compared to traditional methods.

METHOD

Through the use of an animal tissue model, we compared incisions of varying lengths and measured the dimensions of the exposure achieved with disposable wound protectors (Alexis™) and a Mollison self-retainer. We calculated the surface area and, therefore, exposure gained using the specified wound retraction devices and compared the results.

RESULTS

The average superficial surface area of wound with a self-retainer compared to the small and extra-small disposable wound protector was 2.65 cm² vs 2.27 cm² (small) and 2.2 cm² (extra-small) for 2 cm incision length, 3.6 cm² vs 4.93 cm² and 4.2 cm² for 3 cm incision length, 5.19 cm² vs 8.25 cm² and 6.27 cm² for 4 cm incision length, 6.17 cm² vs 12.25 cm² and 9.07 cm² for 5 cm incision length, and 8.75 cm² vs 16.73 cm² and 10.78 cm² for 6 cm incision length [p = 0.038 (small) and p = 0.049 (extra-small)]. Our results show a statistically significant increase in surface area of a wound for each incision length when a disposable wound protector was used for exposure, compared to a self-retainer.

CONCLUSION

Our results demonstrate that the use of disposable wound protectors provides superior surgical exposure for a given incision length compared to traditional techniques in the repair of ventral and open inguinal hernia repairs.

Predicting seasonal occurrence of leatherback turtles (Dermochelys coriacea) in eastern Canadian waters from turtle and ocean sunfish (Mola mola) sighting data and habitat characteristics

Part of the western Atlantic population of leatherback turtles (Dermochelys coriacea (Vandelli, 1761)) forage in Canadian waters, where high-use areas have been identified using satellite telemetry and opportunistic sightings. Here, we use sightings of leatherback turtles and ocean sunfish (Mola mola (Linnaeus, 1758)) obtained during a systematic large-scale aerial survey, along with opportunistic turtle sightings, to examine the seasonal occurrence and distribution of leatherback turtles in eastern Canada. Using environmental correlates, we predict the spatial and seasonal development of potentially suitable habitats. All data sets confirmed the presence of leatherback turtles off Nova Scotia during summer. They also highlighted turtle occurrence off southern Newfoundland. Opportunistic sightings suggest a seasonal shift in main turtle concentrations from southwest to northeast, with use of southern Newfoundland waters extending into September. A generalized additive model linking environmental characteristics and turtle observations suggests adding the Grand Banks off Newfoundland and waters east of Anticosti Island in the Gulf of St. Lawrence to the potentially important habitat for leatherback turtles. Direct observations helped delineate habitat currently used by leatherback turtles. In the context of climate change, this modelling approach may improve our ability to forecast changes in turtle habitat suitability and the risks of entrapment or collision associated with potentially changing usage patterns.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Upregulation of TET activity with ascorbic acid induces epigenetic modulation of lymphoma cells

The Ten Eleven Translocation (TET) enzymes have been found to be mutated in both diffuse large B-cell (DLBCL) and peripheral T-cell (PTCL) lymphomas resulting in DNA hypermethylation. Recent studies in embryonal stem cells showed that ascorbic acid (AA) is a cofactor for TET with a binding site at the catalytic domain, and enhances TET activity. We hypothesized that AA could potentially enhance TET activity in lymphoma cells to cause DNA demethylation, reactivate expression of tumor suppressor genes and enhance chemosensitivity. We demonstrate in vitro that AA treatment of DLBCL and PTCL cells using AA concentrations achievable intravenously increased TET activity leading to DNA demethylation. This epigenetic effect is independent of hydrogen peroxide. AA treatment increased the expression of SMAD1, a tumor suppressor gene known to be suppressed by methylation, and increased chemosensitivity of lymphoma cells. Twenty-nine percent (10/34) of unselected lymphoma patients had plasma AA levels that were deficient suggesting an additional clinical mechanism of TET hypofunction. These data indicate that AA has the potential to modify TET function in lymphoma and enhance chemosensitivity. In addition, the AA deficiency seen in some patients may further impair TET function and contribute to resistance. Clinical trials testing intravenous AA with chemotherapy are warranted.

Efficiency of pragmatic search strategies to update clinical guidelines recommendations

Background

A major challenge in updating clinical guidelines is to efficiently identify new, relevant evidence. We evaluated the efficiency and feasibility of two new approaches: the development of restrictive search strategies using PubMed Clinical Queries for MEDLINE and the use of the PLUS (McMaster Premium Literature Service) database.

Methods

We evaluated a random sample of recommendations from a national guideline development program and identified the references that would potentially trigger an update (key references) using an exhaustive approach.

We designed restrictive search strategies using the minimum number of Medical Subject Headings (MeSH) terms and text words required from the original exhaustive search strategies and applying broad and narrow filters. We developed PLUS search strategies, matching Medical Subject Headings (MeSH) and Systematized Nomenclature of Medicine (SNOMED) terms with guideline topics. We compared the number of key references retrieved by these approaches with those retrieved by the exhaustive approach.

Results

The restrictive approach retrieved 68.1 % fewer references than the exhaustive approach (12,486 versus 39,136), and identified 89.9 % (62/69) of key references and 88 % (22/25) of recommendation updates. The use of PLUS retrieved 88.5 % fewer references than the exhaustive approach (4,486 versus 39,136) and identified substantially fewer key references (18/69, 26.1 %) and fewer recommendation updates (10/25, 40 %).

Conclusions

The proposed restrictive approach is a highly efficient and feasible method to identify new evidence that triggers a recommendation update. Searching only in the PLUS database proved to be a suboptimal approach and suggests the need for topic-specific tailoring.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-015-0058-2) contains supplementary material, which is available to authorized users.

Novel integrative genomic tool for interrogating lithium response in bipolar disorder

We developed a novel integrative genomic tool called GRANITE (Genetic Regulatory Analysis of Networks Investigational Tool Environment) that can effectively analyze large complex data sets to generate interactive networks. GRANITE is an open-source tool and invaluable resource for a variety of genomic fields. Although our analysis is confined to static expression data, GRANITE has the capability of evaluating time-course data and generating interactive networks that may shed light on acute versus chronic treatment, as well as evaluating dose response and providing insight into mechanisms that underlie therapeutic versus sub-therapeutic doses or toxic doses. As a proof-of-concept study, we investigated lithium (Li) response in bipolar disorder (BD). BD is a severe mood disorder marked by cycles of mania and depression. Li is one of the most commonly prescribed and decidedly effective treatments for many patients (responders), although its mode of action is not yet fully understood, nor is it effective in every patient (non-responders). In an in vitro study, we compared vehicle versus chronic Li treatment in patient-derived lymphoblastoid cells (LCLs) (derived from either responders or non-responders) using both microRNA (miRNA) and messenger RNA gene expression profiling. We present both Li responder and non-responder network visualizations created by our GRANITE analysis in BD. We identified by network visualization that the Let-7 family is consistently downregulated by Li in both groups where this miRNA family has been implicated in neurodegeneration, cell survival and synaptic development. We discuss the potential of this analysis for investigating treatment response and even providing clinicians with a tool for predicting treatment response in their patients, as well as for providing the industry with a tool for identifying network nodes as targets for novel drug discovery.

Magnetic diagnostics for equilibrium reconstruction and realtime plasma control in NSTX-Upgrade

This paper describes aspects of magnetic diagnostics for realtime control in National Spherical Torus Experiment-Upgrade (NSTX-U). The sensor arrangement on the upgraded center column is described. New analog and digital circuitry for processing the plasma current Rogowski data are presented. An improved algorithm for estimating the plasma vertical velocity for feedback control is presented.

A survey of the management of transient loss of consciousness in the emergency department

Transient loss of consciousness (TLoC) is a common presentation to the emergency department (ED). We sought to evaluate current practice in the management of patients with TLoC presenting to a large, city centre ED, against national standards.

METHODS

The ED admissions database was searched to identify all patients attending with TLoC during October 2012. The clinical record of the attendance was reviewed to determine if the initial assessment met national standards.

RESULTS

Ninety-one patients had a primary presentation with TLoC, representing 0.95% of ED attendances. Documentation of before/during/after the clinical event and clinical examination were done well. Notable aspects done less well included lying and standing blood pressure and recording of driving status. No patient was discharged from the ED with a copy of their 12-lead electrocardiogram (ECG). Sixty-five patients (71%) were discharged from the ED, with follow-up arranged for 11 (16%). Additional follow-up would have been appropriate in a further 15 cases (28%).

CONCLUSION

Several aspects of the initial assessment of TLoC were done well. Areas for improvement include driving status documentation and advice, recording of postural blood pressures and ECG provision on discharge.

Predictors of recurrence of great saphenous vein reflux following treatment with ultrasound-guided foamsclerotherapy

OBJECTIVE

To investigate which clinical characteristics at baseline are predictive for great saphenous vein recurrence following ultrasound-guided foamsclerotherapy.

MATERIAL AND METHODS

Data of patients treated for great saphenous vein incompetence with ultrasound-guided foamsclerotherapy were derived from a multicentre prospective randomized controlled trial comparing surgery versus ultrasound-guided foamsclerotherapy with a follow-up of two years. Recurrence of reflux was determined on colour duplex scans at three months, one year and two years. Univariate and multivariate Cox regression analysis was used to evaluate the effect of gender, age, C of CEAP classification, diameter of great saphenous vein, injected foam volume, presence of distal great saphenous vein reflux, presence of reflux in the anterior accessory saphenous vein and Venous Clinical Severity Score on risk of recurrent reflux.

RESULTS

Two hundred twenty-five patients were available for analysis. Treatment after one single session was successful in 120 patients and recurrence of saphenous reflux was observed in 105 patients within two years during follow-up. Significant associations with risk of recurrence were observed for mid thigh great saphenous vein diameter (HR = 1.012 with 95% CI: 1.002-1.022, p = 0.022) and presence of distal great saphenous vein reflux (HR = 1.882 with 95% CI: 1.029-3.443, p = 0.040).

CONCLUSION

In conclusion, this prospective study suggests that ultrasound-guided foamsclerotherapy treatment for the proximal great saphenous vein is less effective for patients with a large vein and a refluxing distal great saphenous vein at baseline.

[Reality and importance of transfusion-transmitted malaria in a stable endemic context: Cotonou case in Benin]

Malaria endemic status of our countries supports avoiding malaria screening for the blood qualification. But this attitude makes young children, pregnant women and people without semi-immunity incur a high risk of malaria. The goal of the survey was to value the reality and the importance of transfusion-transmitted malaria and to assess its determining factors. The study included 141 packed-red-cells units transfused to 77 hospitalized recipients, not suffering from malaria and not having been transfused the last two weeks. Every packed-red-cells assigned to a patient was tested for malaria before use. Thick and thin blood film were performed 96hours after transfusion. A clinical follow-up was undertaken as well as in the hospital and at home after release. In all, 13.47% of the transfused packed-red-cells were positive for the thick blood film. Plasmodium research in patients was negative 96hours after transfusion, even in the 19 patients who had received parasitized blood units! The home follow-up had permitted to note that 15.78% of blood recipients had developed clinical malaria. Parasitic density ≥240 parasites/mm(3) seems to be a determining factor. Transfusion-transmitted malaria is a reality we ought to consider. Introduction of malaria screening in donated blood qualification testings simultaneously with a framing of the blood donors appear the lasting solution to hope in the future to limit the waited excessive blood evictions.

Sapheon: the solution?

Less invasive endovenous techniques have been shown to be as effective as open surgery in the treatment of varicose veins. Furthermore, they cause less postoperative bruising and pain and enable early return to normal activities and work. Tumescent anaesthesia is safe and obviates complications of general or spinal anaesthesia. Drawbacks are a steep learning curve and painful administration during treatment. Tumescentless techniques like Clarivein™ or VenaSeal™ Sapheon Closure System are recently under investigation. Short-term results of VenaSeal™ are comparable with thermal ablation. The procedure is safe without serious adverse events. Perioperative pain and patient discomfort with this tumescentless approach is minimal but postoperative recovery is temporarily hindered by thrombophlebitis in 14–15 % of patients. One-year results in a small feasibility study has demonstrated durable closure at this endpoint. No longer-term results are available. A randomized control trial between VenaSeal™ and Covidien ClosureFast™ is in a preparatory phase.

Diagnostic accuracy of mammography readers and their memory performance have no correlation with each other

INTRODUCTION

The study aims to determine if any association exists between visual memory performance and diagnostic accuracy performance in a group of radiologist mammogram readers.

MATERIALS AND METHODS

One hundred proven mammograms (23 with cancers) were grouped into 5 sets of 20 cases, with sets being of equal difficulty. Pairs of sets were presented in 5 reads (40 cases per read, order random) to a panel of 8 radiologist readers (either present or past screening readers, with experience range from <1 year to >20 years). The readers were asked to either 'clear' or 'call back' cases depending on need for further workup, and at post-baseline reads to indicate whether each case was 'new' or 'old' (i.e. remembered from prior read). Two sets were presented only at baseline (40 cases per reader), and were used to calculate the reader's false recollection rate. Three sets were repeated post-baseline once or twice (100 cases per reader). Reading conditions were standardised.

RESULTS

Memory performance differed markedly between readers. The number of correctly remembered cases (of 100 'old' cases) had a median of 10.5 and range of 0-58. The observed number of false recollections (of 40 'totally new' cases) had a median of 2 and range of 0-17. Diagnostic performance measures were mean (range): sensitivity 0.68 (0.54-0.81); specificity 0.82 (0.74-0.91); positive predictive value (PPV) 0.55 (0.50-0.65); negative predictive value (NPV) 0.89 (0.86-0.93) and accuracy 0.78 (0.76-0.83). Confidence intervals (CIs; 95%) for each reader overlapped for all the diagnostic parameters, indicating a lack of statistically significant difference between the readers at the 5% level. The most sensitive and the most specific reader showed a trend away from each other on sensitivity, specificity, NPV and PPV; their accuracies were 0.76 and 0.82, respectively, and their accuracy 95% CIs overlapped considerably. Correlation analysis by reader showed no association between observed memory performance and any of the diagnostic accuracy measures in our group of readers. In particular, there was no correlation between diagnostic accuracy and memory performance.

CONCLUSION

There was no association between visual memory performance and diagnostic accuracy as a screening mammographer in our group of eight representative readers. Whether a radiologist has a good or a bad visual memory for cases, and in particular mammograms, should not impact on his or her performance as a radiologist and mammogram reader.

Executive functioning in Alzheimer's disease and vascular dementia

OBJECTIVE

To compare performance of patients with mild-moderate Alzheimer's disease (AD) and vascular dementia (VaD) on tests of executive functioning and working memory.

METHODS

Patients with AD (n = 76) and VaD (n = 46) were recruited from a memory clinic along with dementia free participants (n = 28). They underwent specific tests of working memory from the Cognitive Drug Research (CDR) battery and pen and paper tests of executive function including CLOX 1 & 2, EXIT25 and a test of verbal fluency (COWAT). All patients had a CT brain scan which was independently scored for white matter change/ischaemia.

RESULTS

The AD and VaD groups were significantly impaired on all measures of working memory and executive functioning compared to the disease free group. There were no significant differences between the AD and VaD groups on any measure. Z-scores confirmed the pattern of impairment in executive functioning and working memory was largely equivalent in both patient groups. Small to moderate correlations were seen between the MMSE and the neurocognitive scores in both patient groups and the pattern of correlations was also very similar in both patient groups.

CONCLUSIONS

This study demonstrates sizeable executive functioning and working memory impairments in patients with mild-moderate AD and VaD but no significant differences between the disease groups.