Demonstration of improved laser preheat with a cryogenically cooled magnetized liner inertial fusion platform

We report on progress implementing and testing cryogenically cooled platforms for Magnetized Liner Inertial Fusion (MagLIF) experiments. Two cryogenically cooled experimental platforms were developed: an integrated platform fielded on the Z pulsed power generator that combines magnetization, laser preheat, and pulsed-power-driven fuel compression and a laser-only platform in a separate chamber that enables measurements of the laser preheat energy using shadowgraphy measurements. The laser-only experiments suggest that ∼89% ± 10% of the incident energy is coupled to the fuel in cooled targets across the energy range tested, significantly higher than previous warm experiments that achieved at most 67% coupling and in line with simulation predictions. The laser preheat configuration was applied to a cryogenically cooled integrated experiment that used a novel cryostat configuration that cooled the MagLIF liner from both ends. The integrated experiment, z3576, coupled 2.32 ± 0.25 kJ preheat energy to the fuel, the highest to-date, demonstrated excellent temperature control and nominal current delivery, and produced one of the highest pressure stagnations as determined by a Bayesian analysis of the data.

O080 A double-blind, placebo-controlled, randomised trial of extracorporeal shockwave therapy as a novel treatment for intermittent claudication

Introduction

Intermittent claudication (IC) is a prevalent manifestation of peripheral arterial disease and affects about 3% of the UK population. Current guidance for the management of nonlife limiting IC is supervised exercise and best medical therapy. Supervised exercise however is not readily available across the nation and has poor recruitment and retention rates. Pilot data has demonstrated that Extracorporeal ShockWave Therapy (ESWT) is effective for improving walking distance in patients with IC. This study aims to consider its effectiveness for improving quality of life (QoL).

Methods

In a double-blind, sham-controlled, randomised trial, patients with IC were randomised in a 1:1 ratio to ESWT or sham treatment. The primary endpoint was change in physical functioning at 12-week follow-up, as measured by the SF-36. Secondary endpoints included changes in walking distances and ABPI.

Results

138 patients were randomised. The ESWT group had a significantly higher physical functioning score at 12 weeks (Mdn 41 vs 34, z=-2.1, p=0.033). They also had significantly longer claudication (Mdn 125 vs 88, z=-2.9, p=0.004) and maximum (Mdn 179 vs 129, z=-2.4, p=0.013) walking distances. The change from baseline to 12-weeks was also significantly greater in the ESWT group for claudication (Mdn 51 vs 24, z=-2.8, p<0.01) and maximum (Mdn 63 vs 17, z=-4 p<0.01) walking distance. No difference observed in ABPI.

Conclusion

This study demonstrates that ESWT is safe, well tolerated and clinically effective for improving QoL and walking distances in patients with IC.

Take-home message

Extracorporeal shockwave therapy improves quality of life and walking distances, and could potentially be used as a non-invasive adjunct to supervised exercise or in institutions were supervised exercise is not available.

O076 Long term outcomes of “Christmas tree” banding for the treatment of dialysis access related steal syndrome: a thirteen-year experience with the technique

Introduction

High flowrates in arterio-venous fistulas (AVF) and the associated distal arterial insufficiency can cause Dialysis-Access related Steal Syndrome (DASS). Various techniques including ligation, banding, and bypass with interval-ligation have been advocated to treat this difficult problem with varying success. We present the long-term outcomes following a novel banding technique.

Methods

46 patients in this prospective cohort-study from 2008–2021 underwent an adjustable banding procedure using a PTFE patch shaped with one slit-end and saw-tooth edges (resulting in a ‘‘Christmas tree’’ pattern) to provide a ratchet mechanism to progressively constrict the draining vein. Real-time finger perfusion pressure monitoring allowed an optimal compromise between distal extremity and AVF perfusion. Comparisons between groups were measured and survival curves were obtained using the Kaplan-Meier method based on the log-rank test to calculate the thrombosis-free survival.

Results

63%(n=29) presented with constant pain and 24%(n=11) presented with tissue loss due to steal syndrome. Post-intervention patency was 100%,97.7%,95%,86% and 72% at 30 days, 60 days, 180 days, 1 year and 3 years, respectively. Complete resolution of symptoms was achieved in 74%(n=34) of patients and 11%(n=5) reported partial response needing no further intervention. We also observed that pre-procedure finger pressures of 41mmHg or below was highly specific for “true” steal-syndrome and these patients were more likely to completely respond to banding (p=0.016). The overall mean thrombosis free survival was seen to be 1844±168 days.

Conclusion

This adjustable dynamic method of AVF banding demonstrates a sustained efficacy in patients with DASS in the long term with a very low risk of patency loss.

Take-home message

The described adjustable dynamic method of AVF banding under local anaesthesia demonstrates a sustained efficacy in patients with DASS in the long term with a very low risk of patency loss.

Identifying the research priorities of healthcare professionals in UK vascular surgery: modified Delphi approach

Background

The Vascular Research Collaborative was established to develop a national research strategy for patients with vascular disease in the UK. This project aimed to establish national research priorities in this patient group.

Methods

A modified Delphi approach, an established method for reaching a consensus opinion among a group of experts in a particular field, was used to survey national multidisciplinary vascular clinical specialists. Two rounds of online surveys were conducted involving the membership of the Vascular Society, Society of Vascular Nurses, Society for Vascular Technology, and the Rouleaux Club (vascular surgical trainees). The first round invited any suggestions for vascular research topics. A steering group then collated and rationalized the suggestions, categorizing them by consensus into pathological topics and research categories, and amalgamating the various questions relating to the same fundamental issue into a single question. The second round involved recirculating these questions to the same participants for priority scoring.

Results

Round 1 resulted in 1231 suggested research questions from 481 respondents. Steering group collation and rationalization resulted in 83 questions for ranking in round 2. The second round resulted in a hierarchical list of vascular research priorities. The highest scoring priorities addressed topics related to critical lower-limb ischaemia, diabetic foot disease, amputation, wound healing, carotid plaque morphology, and service organization/delivery.

Conclusion

It is anticipated that these results will drive the UK national vascular research agenda for the next 5–10 years. It will facilitate focused development and funding of new research projects in current clinical areas of unmet need where potential impact is greatest.

Comparative Effectiveness of Behavioral Interventions to Prevent or Delay Dementia: One-Year Partner Outcomes

BACKGROUND/OBJECTIVE

Various behavioral interventions are recommended to combat the distress experienced by caregivers of those with cognitive decline, but their comparative effectiveness is poorly understood.

DESIGN/SETTING

Caregivers in a comparative intervention study randomly had 1 of 5 possible interventions suppressed while receiving the other four. Caregivers in a full clinical program received all 5 intervention components. Care partner outcomes in the study group were compared to participants enrolled in a full clinical program.

PARTICIPANTS

Two hundred and seventy-two dyads of persons with amnestic mild cognitive impairment (pwMCI) and care partners enrolled in the comparative intervention study. 265 dyads participated in the full clinical program.

INTERVENTION

Behavioral intervention components included: memory compensation training, computerized cognitive training, yoga, support group, and wellness education. Each was administered for 10 sessions over 2 weeks.

MEASUREMENTS

A longitudinal mixed-effect regression model was used to analyze the effects of the interventions on partner burden, quality of life (QoL), mood, anxiety, and self-efficacy at 12 months follow-up.

RESULTS

At 12 months, withholding wellness education or yoga had a significantly negative impact on partner anxiety compared to partners in the clinical program (ES=0.55 and 0.44, respectively). Although not statistically significant, withholding yoga had a negative impact on partner burden and mood compared to partners in the full clinical program (ES=0.32 and 0.36, respectively).

CONCLUSION

Our results support the benefits of wellness education and yoga for improving partner's burden, mood, and anxiety at one year. Our findings are the first to provide an exploration of the impact of multicomponent interventions in care partners of pwMCI.

Machine learning to refine decision making within a syndromic surveillance service

Background

Worldwide, syndromic surveillance is increasingly used for improved and timely situational awareness and early identification of public health threats. Syndromic data streams are fed into detection algorithms, which produce statistical alarms highlighting potential activity of public health importance. All alarms must be assessed to confirm whether they are of public health importance. In England, approximately 100 alarms are generated daily and, although their analysis is formalised through a risk assessment process, the process requires notable time, training, and maintenance of an expertise base to determine which alarms are of public health importance. The process is made more complicated by the observation that only 0.1% of statistical alarms are deemed to be of public health importance. Therefore, the aims of this study were to evaluate machine learning as a tool for computer-assisted human decision-making when assessing statistical alarms.

Methods

A record of the risk assessment process was obtained from Public Health England for all 67,505 statistical alarms between August 2013 and October 2015. This record contained information on the characteristics of the alarm (e.g. size, location). We used three Bayesian classifiers- naïve Bayes, tree-augmented naïve Bayes and Multinets - to examine the risk assessment record in England with respect to the final ‘Decision’ outcome made by an epidemiologist of ‘Alert’, ‘Monitor’ or ‘No-action’. Two further classifications based upon tree-augmented naïve Bayes and Multinets were implemented to account for the predominance of ‘No-action’ outcomes.

Results

The attributes of each individual risk assessment were linked to the final decision made by an epidemiologist, providing confidence in the current process. The naïve Bayesian classifier performed best, correctly classifying 51.5% of ‘Alert’ outcomes. If the ‘Alert’ and ‘Monitor’ actions are combined then performance increases to 82.6% correctly classified. We demonstrate how a decision support system based upon a naïve Bayes classifier could be operationalised within an operational syndromic surveillance system.

Conclusions

Within syndromic surveillance systems, machine learning techniques have the potential to make risk assessment following statistical alarms more automated, robust, and rigorous. However, our results also highlight the importance of specialist human input to the process.

Compliance with NICE guidelines when commissioning varicose vein procedures

Background

Varicose veins impair quality of life and can lead to chronic leg ulcers. National Institute for Health and Care Excellence (NICE) guidelines (CG168) set out evidence-based standards for patient management. In England, Clinical Commissioning Groups (CCGs) fund NHS care within their locality. The objective of this study was to evaluate CCGs' commissioning policies and compare them with CG168.

Methods

Searches were made for the published policies of all 206 English CCGs. They were reviewed for compliance with NICE guidelines and the associated quality standard. Areas of disagreement were analysed for themes.

Results

Some 203 CCGs (98·5 per cent) had a published policy and 190 (93·6 per cent) of these were published after publication of CG168. Only 73 of the policies (36·0 per cent) were compliant with CG168. Treatment was restricted on the basis of clinical disease severity in 119 CCGs (58·6 per cent); 29 (14·3 per cent) stipulated delay of treatment using a 'trial' of conservative treatment; 22 (10·8 per cent) used lifestyle-related factors such as BMI and smoking status to ration treatment. Treatment was commissioned for uncomplicated symptomatic varicose veins in 87 CCGs (42·9 per cent), but some applied additional rationing mechanisms; 109 CCGs (53·7 per cent) would treat oedema, 183 (90·1 per cent) would treat skin and soft tissue damage, 202 (99·5 per cent) healed ulceration, and all would allow active ulcers to be treated.

Discussion

The majority of CCGs in England have commissioning policies that contradict NICE guidelines. Rationing strategies include disease severity, delay and patient lifestyle-related factors, creating unwarranted geographical variation for varicose vein treatment, disregarding the NHS Constitution for England, and perhaps leading to an increase in costly treatment of chronic complications in the long term.

Access to supervised exercise services for peripheral vascular disease patients

Which factors determine the current provision of supervised exercise in the UK?

Quality of life in patients with intermittent claudication

Background

Intermittent claudication (IC) is a common condition that causes pain in the lower limbs when walking and has been shown to severely impact the quality of life (QoL) of patients. The QoL is therefore often regarded as an important measure in clinical trials investigating intermittent claudication. To date, no consensus exits on the type of life questionnaire to be used. This review aims to examine the QoL questionnaires used in trials investigating peripheral arterial disease (PAD).

Material and methods

A systematic review of randomised clinical trials including a primary analysis of QoL via questionnaire was performed. Trials involving patients with diagnosed PAD were included (either clinically or by questionnaire). Any trial which had QoL as the primary outcome data was included with no limit being placed on the type of questionnaire used.

Results

The search yielded a total of 1845 articles of which 31 were deemed appropriate for inclusion in the review. In total, 14 different QoL questionnaires were used across 31 studies. Of the questionnaires 24.06% were missing at least one domain when reported in the results of the study. Mean standard deviation varied widely based on the domain reported, particularly within the SF36.

Discussion

Despite previous recommendations for Europewide standardisation of quality of life assessment, to date no such tool exists. This review demonstrated that a number of different questionnaires remain in use, that their completion is often inadequate and that further evidence-based guidelines on QoL assessment are required to guide future research.

Association between glycaemic control and common infections in people with Type 2 diabetes: a cohort study

AIM

To investigate the impact of glycaemic control on infection incidence in people with Type 2 diabetes.

METHODS

We compared infection rates during 2014 in people with Type 2 diabetes and people without diabetes in a large primary care cohort in the UK (the Royal College of General Practitioners Research and Surveillance Centre database). We performed multilevel logistic regression to investigate the impact of Type 2 diabetes on presentation with infection, and the effect of glycaemic control on presentation with upper respiratory tract infections, bronchitis, influenza-like illness, pneumonia, intestinal infectious diseases, herpes simplex, skin and soft tissue infections, urinary tract infections, and genital and perineal infections. People with Type 2 diabetes were stratified by good [HbA_1c < 53 mmol/mol (< 7%)], moderate [HbA_1c 53-69 mmol/mol (7-8.5%)] and poor [HbA_1c > 69 mmol/mol (> 8.5%)] glycaemic control using their most recent HbA_1c concentration. Infection incidence was adjusted for important sociodemographic factors and patient comorbidities.

RESULTS

We identified 34 278 people with Type 2 diabetes and 613 052 people without diabetes for comparison. The incidence of infections was higher in people with Type 2 diabetes for all infections except herpes simplex. Worsening glycaemic control was associated with increased incidence of bronchitis, pneumonia, skin and soft tissue infections, urinary tract infections, and genital and perineal infections, but not with upper respiratory tract infections, influenza-like illness, intestinal infectious diseases or herpes simplex.

CONCLUSIONS

Almost all infections analysed were more common in people with Type 2 diabetes. Infections that are most commonly of bacterial, fungal or yeast origin were more frequent in people with worse glycaemic control.

Developing and validating a new national remote health advice syndromic surveillance system in England

Background

Public Health England (PHE) coordinates a suite of real-time national syndromic surveillance systems monitoring general practice, emergency department and remote health advice data. We describe the development and informal evaluation of a new syndromic surveillance system using NHS 111 remote health advice data.

Methods

NHS 111 syndromic indicators were monitored daily at national and local level. Statistical models were applied to daily data to identify significant exceedances; statistical baselines were developed for each syndrome and area using a multi-level hierarchical mixed effects model.

Results

Between November 2013 and October 2014, there were on average 19 095 NHS 111 calls each weekday and 43 084 each weekend day in the PHE dataset. There was a predominance of females using the service (57%); highest percentage of calls received was in the age group 1-4 years (14%). This system was used to monitor respiratory and gastrointestinal infections over the winter of 2013-14, the potential public health impact of severe flooding across parts of southern England and poor air quality episodes across England in April 2014.

Conclusions

This new system complements and supplements the existing PHE syndromic surveillance systems and is now integrated into the routine daily processes that form this national syndromic surveillance service.

Everyday Impact of Cognitive Interventions in Mild Cognitive Impairment: a Systematic Review and Meta-Analysis

Cognitive interventions in Mild Cognitive Impairment (MCI) seek to ameliorate cognitive symptoms in the condition. Cognitive interventions may or may not generalize beyond cognitive outcomes to everyday life. This systematic review and meta-analysis sought to assess the effect of cognitive interventions compared to a control group in MCI on generalizability outcome measures [activities of daily living (ADLs), mood, quality of life (QOL), and metacognition] rather than cognitive outcomes alone. PRISMA guidelines were followed. MEDLINE and PsychInfo were utilized as data sources to locate references related to cognitive interventions in individuals with MCI. The cognitive intervention study was required to have a control or alternative treatment comparison group to be included. Thirty articles met criteria, including six computerized cognitive interventions, 14 therapist-based interventions, and 10 multimodal (i.e., cognitive intervention plus an additional intervention) studies. Small, but significant overall median effects were seen for ADLs (d = 0.23), mood (d = 0.16), and metacognitive outcomes (d = 0.30), but not for QOL (d = 0.10). Computerized studies appeared to benefit mood (depression, anxiety, and apathy) compared to controls, while therapist-based interventions and multimodal interventions had more impact on ADLs and metacognitive outcomes than control conditions. The results are encouraging that cognitive interventions in MCI may impact everyday life, but considerably more research is needed. The current review and meta-analysis is limited by our use of only PsychInfo and MEDLINE databases, our inability to read full text non-English articles, and our reliance on only published data to complete effect sizes.

Surveillance of sexually transmitted diseases in general practice: a description of trends in the Royal College of General Practitioners Weekly Returns Service between 1994 and 2001

This paper describes the incidence of sexually transmitted infections (STIs) recorded in the Weekly Returns Service (WRS) between 1994 and 2001. There were approximately 76,500 new diagnoses of STIs (7500 males, 71,000 females) and associated syndromes. Candidiasis was the commonest condition reported in males and females followed by pelvic inflammatory disease. The ratio of males to females was 7.1 for non-specific urethritis, and 9.1 and 2.1 for Reiter's syndrome and pediculosis pubis, respectively. The incidence of anogenital warts and genital herpes changed little over time. New diagnoses of genital herpes were higher in females than in males (ratio 2.8:1), whereas the mean annual incidence of genital warts was similar in males and females. The WRS provides an insight into the burden of STI diagnoses, and diagnoses related to STIs that are managed in general practice, and as such has the potential to make a substantial contribution to STI surveillance in England.

Systematic review of compression following treatment for varicose veins

Background

Consensus regarding compression following treatment of varicose veins has yet to be reached. This systematic review aims to establish the optimal compression regimen after venous treatment.

Methods

A systematic review of MEDLINE, Embase and CENTRAL was performed to identify randomized clinical trials (RCTs) investigating different compression strategies following treatment for superficial venous insufficiency.

Results

Seven RCTs comparing different durations and methods of compression fulfilled the inclusion criteria. The treatment modality was open surgery in three trials, foam sclerotherapy in two and endovenous laser ablation (EVLA) in two trials. The quality of the studies was variable, and significant sources of potential bias were present. Both the studies and compression regimens used were heterogeneous. Ten products were used in six general regimens for a duration of 0–42 days. One study suggested that 7 days rather than 2 days of stockings following EVLA was associated with superior quality of life and less pain at 1 week. Another study reported that, following surgery, application of a compression stocking after 3 days of bandaging was associated with a slightly longer recovery than no compression after 3 days. One study recorded compliance clearly, finding it to be only 40 per cent. The quality and heterogeneity of the studies precluded meta-analysis.

Conclusion

There is currently little quality evidence upon which to base any recommendations concerning compression following treatment for varicose veins.

Self-sampling for community respiratory illness: a new tool for national virological surveillance

This report aims to evaluate the usefulness of self-sampling as an approach for future national surveillance of emerging respiratory infections by comparing virological data from two parallel surveillance schemes in England. Nasal swabs were obtained via self-administered sampling from consenting adults (≥ 16 years-old) with influenza symptoms who had contacted the National Pandemic Flu Service (NPFS) health line during the 2009 influenza pandemic. Equivalent samples submitted by sentinel general practitioners participating in the national influenza surveillance scheme run jointly by the Royal College of General Practitioners (RCGP) and Health Protection Agency were also obtained. When comparable samples were analysed there was no significant difference in results obtained from self-sampling and clinician-led sampling schemes. These results demonstrate that self-sampling can be applied in a responsive and flexible manner, to supplement sentinel clinician-based sampling, to achieve a wide spread and geographically representative way of assessing community transmission of a known organism.

Compression regimes after endovenous ablation for superficial venous insufficiency – A survey of members of the Vascular Society of Great Britain and Ireland

Introduction

The optimal compression regime following ultrasound guided foam sclerotherapy (UGFS), radiofrequency ablation (RFA) and endovenous laser ablation (EVLA) for varicose veins is not known. The aim of this study was to document current practice.

Methods

Postal questionnaire sent to 348 consultant members of the Vascular Society of Great Britain and Ireland.

Results

Valid replies were received from 41% ( n = 141) surgeons representing at least 68 (61%) vascular units. UGFS was used by 74% surgeons, RFA by 70% and EVLA by 32%, but fewer patients received UGFS (median 30) annually, than endothermal treatment (median 50) – P = 0.019. All surgeons prescribed compression: following UGFS for median seven days (range two days to three months) and after endothermal ablation for 10 days (range two days to six weeks) – P = 0.298. Seven different combinations of bandages, pads and compression stockings were reported following UGFS and four after endothermal ablation. Some surgeons advised changing from bandages to stockings from five days (range 1–14) after UGFS. Following endothermal ablation, 71% used bandages only, followed by compression stockings after two days (range 1–14). The majority of surgeons (87%) also treated varicose tributaries: 65% used phlebectomy, the majority (65%) synchronously with endothermal ablation. Concordance of compression regimes between surgeons within vascular units was uncommon. Only seven units using UGFS and six units using endothermal ablation had consistent compression regimes.

Conclusion

Compression regimes after treatments for varicose veins vary significantly: more evidence is needed to guide practice.

Clinical outcomes and quality of life 5 years after a randomized trial of concomitant or sequential phlebectomy following endovenous laser ablation for varicose veins

Background

Endovenous laser ablation (EVLA) is a popular treatment for superficial venous insufficiency. Debate continues regarding the optimal management of symptomatic varicose tributaries following ablation of the main saphenous trunk. This randomized trial compared the 5-year outcomes of endovenous laser therapy with ambulatory phlebectomy (EVLTAP) with concomitant ambulatory phlebectomy, and EVLA alone with sequential treatment if required following a delay of at least 6 weeks.

Methods

Patients undergoing EVLA for great saphenous vein insufficiency were randomized to receive EVLTAP or EVLA alone with sequential phlebectomy, if required. Outcomes included disease-specific quality of life (QoL) (Aberdeen Varicose Vein Questionnaire; AVVQ), requirement for secondary procedures, clinical severity (Venous Clinical Severity Score; VCSS), residual and recurrent varicose tributaries, and generic QoL. Patients were followed up for 5 years.

Results

Fifty patients were randomized equally into two parallel groups. The EVLTAP group had lower VCSS scores at 12 weeks (median 0 (i.q.r. 0–1) versus 2 (0–2); P &lt;0·001), and lower AVVQ scores at 6 weeks (median 7·9 (i.q.r. 4·1–10·7) versus 13·5 (10·9–18·1); P &lt; 0·001) and 12 weeks (2·0 (0·4–7·7) versus 9·6 (2·2–13·8); P = 0·015). VCSS and AVVQ scores were equivalent by 1 year, but only after 16 of 24 patients in the EVLA group, compared with one of 25 in the EVLTAP group (P &lt; 0·001), had received a secondary intervention. From 1 to 5 years both groups had equivalent outcomes.

Conclusion

EVLA with either concomitant or sequential management of tributaries is acceptable treatment for symptomatic varicose veins, with both treatments achieving excellent results at 5 years. Concomitant treatment of varicosities is associated with optimal improvement in both clinical disease severity and QoL.

Uptake and impact of a new live attenuated influenza vaccine programme in England: early results of a pilot in primary school-age children, 2013/14 influenza season

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Uptake and impact of a new live attenuated influenza vaccine programme in England: early results of a pilot in primary school-age children, 2013/14 influenza season

As part of the introduction and roll-out of a universal childhood live-attenuated influenza vaccination programme, 4–11 year-olds were vaccinated in seven pilot areas in England in the 2013/14 influenza season. This paper presents the uptake and impact of the programme for a range of disease indicators. End-of-season uptake was defined as the number of children in the target population who received at least one dose of influenza vaccine. Between week 40 2013 and week 15 2014, cumulative disease incidence per 100,000 population (general practitioner consultations for influenza-like illness and laboratory-confirmed influenza hospitalisations), cumulative influenza swab positivity in primary and secondary care and cumulative proportion of emergency department respiratory attendances were calculated. Indicators were compared overall and by age group between pilot and non-pilot areas. Direct impact was defined as reduction in cumulative incidence based on residence in pilot relative to non-pilot areas in 4–11 year-olds. Indirect impact was reduction between pilot and non-pilot areas in <4 year-olds and >11 year-olds. Overall vaccine uptake of 52.5% (104,792/199,475) was achieved. Although influenza activity was low, a consistent, though not statistically significant, decrease in cumulative disease incidence and influenza positivity across different indicators was seen in pilot relative to non-pilot areas in both targeted and non-targeted age groups, except in older age groups, where no difference was observed for secondary care indicators.

Randomized clinical trial of selective versus routine preoperative duplex ultrasound imaging before arteriovenous fistula surgery

Background

Anatomical suitability for arteriovenous fistula (AVF) formation was formerly determined by clinical examination alone. There are potential benefits from imaging to assess anatomical suitability. Existing studies examined the role of routine preoperative ultrasonography versus clinical examination alone. The role of a selective duplex ultrasound imaging policy is unknown. This study aimed to compare a policy of selective versus routine ultrasound assessment before AVF formation.

Methods

All patients referred for fistula formation were assessed for inclusion. Suitable patients were randomized to either routine or selective preoperative ultrasound imaging; selective imaging was performed only when clinical criteria were not met. The primary outcome measures were site of AVF formation and 30-day primary failure rate, and secondary outcome measures included the rate of complications.

Results

A total of 106 patients were assessed, and 94 were randomized: 47 to selective and 47 to routine duplex ultrasonography. The groups were well matched for age, co-morbidities and medications. The primary failure rate (29 per cent overall) was not significantly different between the selective and routine imaging groups: 36 per cent (14 of 39) and 21 per cent (8 of 38) respectively (P = 0·144). There were no significant differences in the sites of AVF formation or complication rates.

Conclusion

Routine preoperative ultrasound vessel imaging did not significantly reduce early failure rates, influence the site of AVF formation or reduce complications. If clinical evaluation detects anatomy suitable for AVF formation, duplex imaging may not be needed. Registration number: NCT01004627 (http://www.clinicaltrials.gov).

The impact of thunderstorm asthma on emergency department attendances across London during July 2013

BACKGROUND

This study illustrates the potential of using emergency department attendance data, routinely accessed as part of a national syndromic surveillance system, to monitor the impact of thunderstorm asthma.

METHODS

The Emergency Department Syndromic Surveillance System (EDSSS) routinely monitors anonymised attendance data on a daily basis across a sentinel network of 35 emergency departments. Attendance data for asthma, wheeze and difficulty breathing are analysed on a daily basis.

RESULTS

A statistically significant spike in asthma attendances in two EDSSS emergency departments in London was detected on 23 July 2013, coinciding with a series of large violent thunderstorms across southern England. There was also an increase in the reported severity of these attendances.

CONCLUSIONS

This preliminary report illustrates the potential of the EDSSS to monitor the impact of thunderstorms on emergency department asthma attendances. Further work will focus on how this system can be used to quantify the impact on emergency departments, thus potentially improving resource planning and also adding to the thunderstorm asthma evidence-base.

The apolipoprotein E genotype predicts longitudinal transitions to mild cognitive impairment but not to Alzheimer's dementia: findings from a nationally representative study

OBJECTIVE

The ε4 allele of the apolipoprotein E (APOE) genotype is the most widely accepted genetic risk factor for Alzheimer's dementia (AD), but findings on whether it is a risk factor for the AD prodrome, mild cognitive impairment (MCI), have been inconsistent. In a prospective longitudinal design, we investigated (a) whether transitions to MCI and other forms of neurocognitive impairment without dementia (CIND) are more frequent among normal ε4 carriers than among noncarriers and (b) whether subsequent transitions to AD from MCI and from other forms of CIND are more frequent among ε4 carriers than among noncarriers.

METHOD

The frequency of the ε4 allele was studied in older adults (mean age > 70), who had participated in two or more waves of neuropsychological testing and diagnosis in the Aging, Demographics, and Memory Study (ADAMS) of the United States Department of Health and Human Services, National Institutes of Health, National Institute on Aging's Health and Retirement Study, conducted by the University of Michigan. The association between ε4 and longitudinal transitions to specific types of CIND and dementia can be determined with this data set.

RESULTS

Epsilon 4 increased the rate of progression from normal functioning to MCI (58% of new diagnoses were carriers) but not to other forms of CIND. The rate of progression to AD from MCI or from other forms of CIND was not increased by ε4.

CONCLUSIONS

The results support the hypothesis that ε4 is a risk factor for transitions from normal functioning to MCI but not for subsequent transitions to AD. In the ADAMS sample, the reason ε4 is elevated in AD individuals is because it is already elevated in MCI individuals, who are the primary source of new AD diagnoses.

Challenges and lessons learned from implementing a risk-based approach to school advice and closure during the containment phase of the 2009 influenza pandemic in the West Midlands, England

OBJECTIVE

School closure as a social distancing measure was used in some countries during the initial phases of the influenza A(H1N1)pdm09 pandemic. The objective of this paper is to describe the use of a risk-based approach to public health interventions for schools during the 'containment phase' of the pandemic and to describe lessons learnt.

METHODS

The development of a framework for risk assessment and decision-making to determine school closures in the West Midlands, England, during the 'containment phase' of influenza A(H1N1)pdm09 pandemic is described.

RESULTS

Using the framework developed during the 'containment phase', assessments were conducted for 344 educational institutions who reported confirmed cases or 'particularly high absenteeism'. Of these, 209 (60%) had confirmed cases and 65 were closed, mainly for public health or operational reasons. Schools were closed on an individual basis, during the most intense period of the pandemic and for an average period of six days (maximum 11 days). The risk-based approach evolved as experience and knowledge of influenza A(H1N1)pdm09 pandemic virus increased, however some decisions were difficult to communicate to parents, schools and stakeholders particularly when the number of schools affected escalated and the pandemic response phases changed.

CONCLUSION

The management of school closures is an 'uncertain art'. Numerous challenges and lessons were identified in attempting, during the containment phase of the influenza A(H1N1)pdm09 pandemic, to ensure consistency and transparency in an increasingly complex process. The overall approach described could be further developed to improve decision-making for infectious diseases in schools.

The memory support system for mild cognitive impairment: randomized trial of a cognitive rehabilitation intervention

OBJECTIVE

Individuals with amnestic mild cognitive impairment (MCI) have few empirically based treatment options for combating their memory loss. This study sought to examine the efficacy of a calendar/notebook rehabilitation intervention, the memory support system (MSS), for individuals with amnestic MCI.

METHODS

Forty individuals with single domain amnestic MCI and their program partners were randomized to receive the MSS, either with training or without (controls). Measures of adherence, activities of daily living, and emotional impact were completed at the first and last intervention sessions and again at 8 weeks and 6 months post intervention.

RESULTS

Training in use of a notebook/calendar system significantly improved adherence over those who received the calendars but no training. Functional ability and memory self-efficacy significantly improved for those who received MSS training. Change in functional ability remained significantly better in the intervention group than in the control group out to 8-week follow-up. Care partners in the intervention group demonstrated improved mood by 8-week and 6-month follow-ups, whereas control care partners reported worse caregiver burden by 6-month follow-up.

CONCLUSIONS

Memory support system training resulted in improvement in activities of daily living and sense of memory self-efficacy for individuals with MCI. Although activities of daily living benefits were maintained out to 8 weeks post intervention, future inclusion of booster sessions may help extend the therapeutic effect out even further. Improved mood of care partners of trained individuals and worsening sense of caregiver burden over time for partners of untrained individuals further support the efficacy of the MSS for MCI.

Developing a new syndromic surveillance system for the London 2012 Olympic and Paralympic Games

Syndromic surveillance is vital for monitoring public health during mass gatherings. The London 2012 Olympic and Paralympic Games represents a major challenge to health protection services and community surveillance. In response to this challenge the Health Protection Agency has developed a new syndromic surveillance system that monitors daily general practitioner out-of-hours and unscheduled care attendances. This new national system will fill a gap identified in the existing general practice-based syndromic surveillance systems by providing surveillance capability of general practice activity during evenings/nights, over weekends and public holidays. The system will complement and supplement the existing tele-health phone line, general practitioner and emergency department syndromic surveillance systems. This new national system will contribute to improving public health reassurance, especially to meet the challenges of the London 2012 Olympic and Paralympic Games.

Saphenopopliteal ligation and stripping of small saphenous vein: does extended stripping provide better results?

OBJECTIVE

Saphenopopliteal ligation (SPL) for venous insufficiency is a challenging procedure, with mixed results being reported. The role of stripping of the small saphenous vein (SSV) is contentious. This prospective observational study aimed to assess the risks and benefits of this procedure.

METHODS

Fifty patients underwent SPL under general anaesthesia by a single surgeon in a tertiary referral vascular centre. The aim was to perform inversion stripping in each case, but in a proportion this was not possible. Patients were grouped into SPL with short segment excision ≤5 cm (n = 23) and SPL with extended stripping >5 cm (n = 27). Outcome measures included venous clinical severity scores (VCSS), quality of life (QoL), Aberdeen varicose vein questionnaire (AVVQ), patient satisfaction, recurrence and complication rates.

RESULTS

Intragroup analysis demonstrated statistically significant improvements in VCSS (P < 0.001), and QoL measures (generic and disease-specific AVVQ) (P < 0.050) with both treatments. Intergroup analysis demonstrated statistically significant superior VCSS scores at one year (P = 0.001), AVVQ at three months and one year (P < 0.05), and cosmetic satisfaction at one year (P = 0.011) in the SPL extended stripping group. There was no difference in clinical recurrence 1/23 (4.3%) versus 1/27 (3.7%) (P = 0.900) or complication rates (P > 0.050).

CONCLUSIONS

SPL with or without stripping is an effective procedure improving clinical severity and QoL in the short term. Early outcomes favour SPL with extended stripping to offer greater improvement in disease-specific QoL, venous severity and cosmesis. With this small sample, there is no evidence of increased complications following stripping, or increased short-term recurrence without it. Greater numbers and follow-up are required to make firm conclusions.

Inclusion of RBD improves the diagnostic classification of dementia with Lewy bodies

OBJECTIVE

To determine whether adding REM sleep behavior disorder (RBD) to the dementia with Lewy bodies (DLB) diagnostic criteria improves classification accuracy of autopsy-confirmed DLB.

METHODS

We followed 234 consecutive patients with dementia until autopsy with a mean of 4 annual visits. Clinical diagnoses included DLB, Alzheimer disease (AD), corticobasal syndrome, and frontotemporal dementia. Pathologic diagnoses used the 2005 DLB consensus criteria and included no/low likelihood DLB (non-DLB; n = 136) and intermediate/high likelihood DLB (DLB; n = 98). Regression modeling and sensitivity/specificity analyses were used to evaluate the diagnostic role of RBD.

RESULTS

Each of the 3 core features increased the odds of autopsy-confirmed DLB up to 2-fold, and RBD increased the odds by 6-fold. When clinically probable DLB reflected dementia and 2 or more of the 3 core features, sensitivity was 85%, and specificity was 73%. When RBD was added and clinically probable DLB reflected 2 or more of 4 features, sensitivity improved to 88%. When dementia and RBD were also designated as probable DLB, sensitivity increased to 90% while specificity remained at 73%. The VH, parkinsonism, RBD model lowered sensitivity to 83%, but improved specificity to 85%.

CONCLUSIONS

Inclusion of RBD as a core clinical feature improves the diagnostic accuracy of autopsy-confirmed DLB.

Diffusion tensor imaging and cognitive function in older adults with no dementia

OBJECTIVE

To determine the patterns of diffusivity associated with cognitive domain functions in older adults without dementia.

METHODS

We studied older adults without dementia (n = 220) who underwent neuropsychometric testing and a diffusion tensor imaging (DTI) examination at 3 T in a cross-sectional study. Memory, language, attention/executive function, and visual-spatial processing domains were assessed within 4 months of the MRI examination. A fluid-attenuated inversion recovery-based DTI sequence that enabled uncontaminated cortical diffusion measurements was performed. Associations between cortical mean diffusivity (MD) and cognitive function were tested using voxel-based regression analysis. Association between tract diffusivity and cognitive function was tested with regions of interest drawn on color-coded fractional anisotropy (FA) maps.

RESULTS

Memory function was associated with the medial temporal lobe cortical MD on voxel-based analysis (p < 0.001, corrected for multiple comparisons), and inferior longitudinal fasciculus and posterior and anterior cingulum FA on tract-based analysis (p < 0.001). Language function was associated with the left temporal lobe cortical MD (p < 0.001, corrected for multiple comparisons), inferior longitudinal fasciculus, fornix, and posterior cingulum FA (p < 0.05). Attention and executive function was associated with the posterior and anterior cingulum FA, and visual-spatial function was associated with posterior cingulum FA (p < 0.01).

CONCLUSION

Specific cognitive domain functions are associated with distinct patterns of cortical and white matter diffusivity in elderly with no dementia. Posterior cingulum tract FA was associated with all 4 cognitive domain functions, in agreement with the hypothesis that the posterior cingulate cortex is the main connectivity hub for cognitive brain networks. Microstructural changes identified on DTI may be associated with neurodegenerative pathologies underlying cognitive changes in older adults without dementia.

Early spread of the 2009 influenza A(H1N1) pandemic in the United Kingdom – use of local syndromic data, May–August 2009

Following the confirmation of the first two cases of pandemic influenza on 27 April 2009 in the United Kingdom (UK), syndromic surveillance data from the Health Protection Agency (HPA)/QSurveillance and HPA/NHS Direct systems were used to monitor the possible spread of pandemic influenza at local level during the first phase of the outbreak. During the early weeks, syndromic indicators sensitive to influenza activity monitored through the two schemes remained low and the majority of cases were travel-related. The first evidence of community spread was seen in the West Midlands region following a school-based outbreak in central Birmingham. During the first phase several Primary Care Trusts had periods of exceptional influenza activity two to three weeks ahead of the rest of the region. Community transmission in London began slightly later than in the West Midlands but the rates of influenza-like illness recorded by general practitioners (GPs) were ultimately higher. Influenza activity in the West Midlands and London regions peaked a week before the remainder of the UK. Data from the HPA/NHS Direct and HPA/QSurveillance systems were mapped at local level and used alongside laboratory data and local intelligence to assist in the identification of hotspots, to direct limited public health resources and to monitor the progression of the outbreak. This work has demonstrated the utility of local syndromic surveillance data in the detection of increased transmission and in the epidemiological investigation of the pandemic and has prompted future spatio-temporal work.

Early spread of the 2009 influenza A(H1N1) pandemic in the United Kingdom--use of local syndromic data, May-August 2009

Following the confirmation of the first two cases of pandemic influenza on 27 April 2009 in the United Kingdom (UK), syndromic surveillance data from the Health Protection Agency (HPA)/QSurveillance and HPA/NHS Direct systems were used to monitor the possible spread of pandemic influenza at local level during the first phase of the outbreak. During the early weeks, syndromic indicators sensitive to influenza activity monitored through the two schemes remained low and the majority of cases were travel-related. The first evidence of community spread was seen in the West Midlands region following a school-based outbreak in central Birmingham. During the first phase several Primary Care Trusts had periods of exceptional influenza activity two to three weeks ahead of the rest of the region. Community transmission in London began slightly later than in the West Midlands but the rates of influenza-like illness recorded by general practitioners (GPs) were ultimately higher. Influenza activity in the West Midlands and London regions peaked a week before the remainder of the UK. Data from the HPA/NHS Direct and HPA/QSurveillance systems were mapped at local level and used alongside laboratory data and local intelligence to assist in the identification of hotspots, to direct limited public health resources and to monitor the progression of the outbreak. This work has demonstrated the utility of local syndromic surveillance data in the detection of increased transmission and in the epidemiological investigation of the pandemic and has prompted future spatio-temporal work.

Value of syndromic surveillance in monitoring a focal waterborne outbreak due to an unusual Cryptosporidium genotype in Northamptonshire, United Kingdom, June – July 2008

The United Kingdom (UK) has several national syndromic surveillance systems. The Health Protection Agency (HPA)/NHS Direct syndromic surveillance system uses pre-diagnostic syndromic data from a national telephone helpline, while the HPA/QSurveillance national surveillance system uses clinical diagnosis data extracted from general practitioner (GP)-based clinical information systems. Data from both of these systems were used to monitor a local outbreak of cryptosporidiosis that occurred following Cryptosporidium oocyst contamination of drinking water supplied from the Pitsford Reservoir in Northamptonshire, United Kingdom, in June 2008. There was a peak in the number of calls to NHS Direct concerning diarrhoea that coincided with the incident. QSurveillance data for the local areas affected by the outbreak showed a significant increase in GP consultations for diarrhoea and gastroenteritis in the week of the incident but there was no increase in consultations for vomiting. A total of 33 clinical cases of cryptosporidiosis were identified in the outbreak investigation, of which 23 were confirmed as infected with the outbreak strain. However, QSurveillance data suggest that there were an estimated 422 excess diarrhoea cases during the outbreak, an increase of about 25% over baseline weekly levels. To our knowledge, this is the first time that data from a syndromic surveillance system, the HPA/QSurveillance national surveillance system, have been able to show the extent of such a small outbreak at a local level. QSurveillance, which covers about 38% of the UK population, is currently the only GP database that is able to provide data at local health district (primary care trust) level. The Cryptosporidium contamination incident described demonstrates the potential usefulness of this information, as it is unusual for syndromic surveillance systems to be able to help monitor such a small-scale outbreak.

Orientation of the Genome of Autographa californica Nuclear Polyhedrosis Virus: a Proposal

The nuclear polyhedrosis virus of the alfalfa looper Autographa californica contains a double-stranded, circular DNA genome. Fourteen scientists agreed to accept an orientation of this circular genome with respect to a physical map of the restriction endonuclease cleavage sites.

Acquisition of Host Cell DNA Sequences by Baculoviruses: Relationship Between Host DNA Insertions and FP Mutants of Autographa californica and Galleria mellonella Nuclear Polyhedrosis Viruses

Mutants of Autographa californica and Galleria mellonella nuclear polyhedrosis viruses, which produce an altered plaque phenotype as a result of reduced numbers of viral occlusions in infected cells, were isolated after passage in Trichoplusia ni (TN-368) cells. These mutants, termed FP (few-polyhedra) mutants, had acquired cell DNA sequences ranging from 0.8 to 2.8 kilobase pairs in size. The insertions of cell DNA occurred in a specific region between 35.0 and 37.7 map units of the A. californica viral genome. A cloned viral fragment containing one of the host DNA inserts was homologous to host DNA inserts in two other mutant viruses and to dispersed, repetitious sequences in T. ni cell DNA. Most of the homology between the cloned insert and cell DNA was contained within a 1,280-base-pair AluI fragment. Marker rescue studies and analysis of infected-cell-specific proteins suggested that the insertion of cell DNA into the viral genomes resulted in the FP plaque phenotype, possibly through the inactivation of a 25,000-molecular-weight protein.

In Vitro Translation of Autographa californica Nuclear Polyhedrosis Virus Early and Late mRNAs

A preliminary translational map of the Autographa californica genome was constructed. Eighteen viral DNA restriction fragments were either purified from agarose gels or obtained from pBR322 recombinant DNA plasmids to locate specific gene products. The DNAs were immobilized on nitrocellulose filters and used to select viral mRNAs isolated from RNA obtained from the cytoplasm of infected Spodoptera frugiperda cells at 21 h postinfection. The fragment-specific mRNAs were translated in vitro in the presence of l-[(3)H]leucine by using a rabbit reticulocyte lysate system and analyzed on sodium dodecyl sulfate-polyacrylamide gels. The approximate locations of 19 A. californica nuclear polyhedrosis virus (AcMNPV) gene products were mapped. The genes for mRNAs present late in viral infection were mapped to DNA fragments that represent nearly the entire genome. The molecular weights of many of these proteins were similar to those present in purified AcMNPV extracellular virus and to proteins being made in infected cells at 18 to 21 h postinfection. Cytoplasmic RNA was isolated at 4 h postinfection from infected cells, a time early in the viral infection cycle, and hybridized to AcMNPV DNA immobilized on nitrocellulose filters. AcMNPV-specific early RNA was translated in vitro into at least six polypeptides, the most abundant having a molecular weight of 39,000. Viral polypeptides were detected in cells pulse-labeled with l-[(3)H]leucine at 3 to 6 h postinfection, with molecular weights similar to those of polypeptides made in vitro from early AcMNPV mRNA.

Molecular Engineering of the Autographa californica Nuclear Polyhedrosis Virus Genome: Deletion Mutations Within the Polyhedrin Gene

We describe a method to introduce site-specific mutations into the genome of Autographa californica nuclear polyhedrosis virus. Specifically, the A. californica nuclear polyhedrosis virus gene for polyhedrin, the major protein that forms viral occlusions in infected cells, was mutagenized by introducing deletions into the cloned DNA fragment containing the gene. The mutagenized polyhedrin gene was transferred to the intact viral DNA by mixing fragment and viral DNAs, cotransfecting Spodoptera frugiperda cells, and screening for viral recombinants that had undergone allelic exchange. Recombinant viruses with mutant polyhedrin genes were obtained by selecting the progeny virus that did not produce viral occlusions in infected cells (occlusion-negative mutants). Analyses of occlusion-negative mutants demonstrated that the polyhedrin gene was not essential for the production of infectious virus and that deletion of certain sequences within the gene did not alter the control, or decrease the level of expression, of polyhedrin. An early viral protein of 25,000 molecular weight was apparently not essential for virus replication in vitro, as the synthesis of this protein was not detected in cells infected with a mutant virus.