Comparison of tetramethylammonium hydroxide (TMAH), trimethylsulfonium hydroxide (TMSH), and trimethylphenylammonium hydroxide (TMPAH) thermochemolysis for in situ space analysis of organic molecules in planetary environments

One of the main objectives of present and future space exploration missions dedicated to astrobiology is the detection of organic molecules of interest for life (e.g. amino and fatty acids). With this aim, a sample preparation and a gas chromatograph (connected to a mass spectrometer) are generally used. To date, tetramethylammonium hydroxide (TMAH) has been the first and only thermochemolysis reagent to be used for in situ sample preparation and chemical analysis of planetary environments. Although TMAH is widely used in terrestrial laboratories, numerous applications also leverage other thermochemolysis reagents that may be more relevant than TMAH to meet both scientific and technical objectives of space instrumentation. The present study compares the performance of tetramethylammonium hydroxide (TMAH), trimethylsulfonium hydroxide (TMSH), and trimethylphenylammonium hydroxide (TMPAH) reagents on molecules of interest to astrobiology. The study focuses on the analyses of 13 carboxylic acids (C₇-C₃₀), 17 proteinic amino acids, and the 5 nucleobases. Here we report the derivatization yield without stirring or adding solvents, the detection sensitivity with mass spectrometry, and the nature of the degradation products from the reagents produced during pyrolysis. We conclude that TMSH and TMAH are the best reagents for analyzing carboxylic acids and nucleobases. Amino acids are not relevant targets for a thermochemolysis over 300 °C as they are degraded and showed high limits of detection. As TMAH, and probably TMSH, meet the space instrumentation requirements, this study informs sample treatment approaches prior to GC-MS analysis in in situ space studies. The thermochemolysis reaction using TMAH or TMSH is also recommended for space return missions to extract organics from a macromolecular matrix, derivatize polar or refractory organic targets, and volatilize with the fewest organic degradations.

Effects of COVID-19 on Vaccine-Preventable Disease Surveillance Systems in the World Health Organization African Region, 2020

Global emergence of the COVID-19 pandemic in 2020 curtailed vaccine-preventable disease (VPD) surveillance activities, but little is known about which surveillance components were most affected. In May 2021, we surveyed 214 STOP (originally Stop Transmission of Polio) Program consultants to determine how VPD surveillance activities were affected by the COVID-19 pandemic throughout 2020, primarily in low- and middle-income countries, where program consultants are deployed. Our report highlights the responses from 154 (96%) of the 160 consultants deployed to the World Health Organization African Region, which comprises 75% (160/214) of all STOP Program consultants deployed globally in early 2021. Most survey respondents observed that VPD surveillance activities were somewhat or severely affected by the COVID-19 pandemic in 2020. Reprioritization of surveillance staff and changes in health-seeking behaviors were factors commonly perceived to decrease VPD surveillance activities. Our findings suggest the need for strategies to restore VPD surveillance to prepandemic levels.

Transcutaneous electrical stimulation in obstructive sleep apnoea: current developments and concepts of the TESLA-home programme

PURPOSE OF REVIEW

Obstructive sleep apnoea (OSA) is a highly prevalent condition affecting about 1 billion people worldwide. The first line therapy for most patients with OSA is continuous positive airway pressure (CPAP) therapy. However, there are significant limitations with long-term adherence to CPAP therapy, which may be as low as 30-60%.

RECENT FINDING

Electrical stimulation of the hypoglossal nerve has been studied in recent years. It achieves upper airway patency by causing a contraction of the genioglossus muscle, the strongest dilator of the upper airway, and by maintaining its neuromuscular tone in the asleep patient with OSA. Electrical stimulation can be delivered invasively, hypoglossal nerve stimulation (HNS), and noninvasively, transcutaneous electrical stimulation in OSA (TESLA). However, randomised controlled trials, the STAR and the TESLA trial, have provided promising results on efficacy and safety of the methods.

SUMMARY

Patient and public involvement underlines the interest in TESLA and HNS and highlights the need to provide non-CPAP therapeutic options to those who may find it difficult to cope with first line therapies. The relatively low costs and the favourable safety profile of the TESLA approach provide the chance to offer this treatment to patients with OSA following further development of the evidence.

Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars

The Perseverance rover landed in Jezero crater, Mars, to investigate ancient lake and river deposits. We report observations of the crater floor, below the crater's sedimentary delta, finding the floor consists of igneous rocks altered by water. The lowest exposed unit, informally named Séítah, is a coarsely crystalline olivine-rich rock, which accumulated at the base of a magma body. Fe-Mg carbonates along grain boundaries indicate reactions with CO₂-rich water, under water-poor conditions. Overlying Séítah is a unit informally named Máaz, which we interpret as lava flows or the chemical complement to Séítah in a layered igneous body. Voids in these rocks contain sulfates and perchlorates, likely introduced by later near-surface brine evaporation. Core samples of these rocks were stored aboard Perseverance for potential return to Earth.

Feasibility and acceptability of experience sampling among LGBTQ+ young people with self-harmful thoughts and behaviours

This study was the first to determine whether it was feasible and acceptable to use experience sampling methods (ESM) among LGBTQ+ young people, who had current experiences of self-harm. Sixteen LGBTQ+ young people (16-25 years old) took part in the experience sampling study. This included a baseline assessment, a 7-day ESM assessment (participants were sampled six times a day using a phone app), and the option of an interview at the end of the 7-day ESM assessment. Feasibility data was descriptively analysed, with pilot ESM data presented. Qualitative data was thematically analysed to determine the acceptability (barriers and facilitators) of taking part in this study. Study feasibility was assessed by enrolment rate (55.2%), participant retention across assessment period (100%), ESM app feasibility (87.5%), and good adherence to total number of ESM surveys (67.6%). Individual study adherence ranged between 43 and 95.2%. Study acceptability was assessed by participant interviews. Thematic analysis indicated four superordinate themes; (i) Self-reflection and awareness; (ii) Practicalities of ESM surveys; (iii) Daily timeframes; and (iv) Suggestions for future studies. Pilot ESM data demonstrates that there was fluctuation of depressive and anxiety symptoms within- and between- participants over the course of the study, however, greater sample power is needed for full analysis. This study demonstrated that ESM designs are feasible and acceptable among LGBTQ+ young people with current experiences of self-harm. Pilot data indicated that specific experiences and moods are likely to be important to self-harm. These potentially have a temporal influence on self-harm behaviour or ideation, and therefore should be examined in a fully powered sample.

Perseverance rover reveals an ancient delta-lake system and flood deposits at Jezero crater, Mars

[Figure: see text].

Validation of a New Contactless and Continuous Respiratory Rate Monitoring Device Based on Ultra-Wideband Radar Technology

Respiratory rate (RR) is typically the first vital sign to change when a patient decompensates. Despite this, RR is often monitored infrequently and inaccurately. The Circadia Contactless Breathing Monitor™ (model C100) is a novel device that uses ultra-wideband radar to monitor RR continuously and un-obtrusively. Performance of the Circadia Monitor was assessed by direct comparison to manually scored reference data. Data were collected across a range of clinical and non-clinical settings, considering a broad range of user characteristics and use cases, in a total of 50 subjects. Bland-Altman analysis showed high agreement with the gold standard reference for all study data, and agreement fell within the predefined acceptance criteria of ±5 breaths per minute (BrPM). The 95% limits of agreement were -3.0 to 1.3 BrPM for a nonprobability sample of subjects while awake, -2.3 to 1.7 BrPM for a clinical sample of subjects while asleep, and -1.2 to 0.7 BrPM for a sample of healthy subjects while asleep. Accuracy rate, using an error margin of ±2 BrPM, was found to be 90% or higher. Results demonstrate that the Circadia Monitor can effectively and efficiently be used for accurate spot measurements and continuous bedside monitoring of RR in low acuity settings, such as the nursing home or hospital ward, or for remote patient monitoring.

Performance Evaluation of the Circadia Contactless Breathing Monitor and Sleep Analysis Algorithm for Sleep Stage Classification

Although polysomnography (PSG) remains the gold standard for studying sleep in the lab, the development of wearable and 'nearable' non-EEG based sleep monitors has the potential to make long-term sleep monitoring in a home environment possible. However, validation of these novel technologies against PSG is required. The current study aims to evaluate the sleep staging performance of the radar-based Circadia Contactless Breathing Monitor (model C100) and proprietary Sleep Analysis Algorithm, both in a home and sleep lab environment, on cohorts of healthy sleepers. The C100 device was initially used to record 17 nights of sleep data from 9 participants alongside PSG, with a subsequent 24 nights of PSG data for validation purposes. Respiration and body movement features were extracted from sensor data, and a machine learning algorithm was developed to perform sleep stage prediction. The algorithm was trained using PSG data obtained in the initial dataset (n=17), and validated using leave- one-subject-out cross-validation. An epoch-by-epoch recall (true positive rate) of 75.0 %, 59.9 %, 74.8 % and 57.1 %, was found for 'Deep', 'Light', 'REM' and 'Wake' respectively. Highly similar results were obtained in the independent validation dataset (n=24), indicating robustness of results and generalizability of the sleep staging model, at least in the healthy population. The device was found to outperform both a consumer and medical grade wrist-worn monitoring device (Fitbit Alta HR and Philips Respironics Actiwatch) on sleep metric estimation accuracy. These results indicate that the developed non-contact monitor forms a viable alternative to existing clinically used wrist-worn methods, and that longitudinal monitoring of sleep stages in a home environment becomes feasible.

Feasibility and acceptability of an intervention for enhancing reintegration in adults with experience of homelessness

BACKGROUND

Service centres for homeless adults are potential settings for implementation of reintegration interventions. This study aimed to evaluate (i) the acceptability of a group-based programme among individuals from the broad population of homeless people and (ii) if a future study of its feasibility and acceptability for re-housed homeless people is warranted.

METHODS

Recruiting participants and intervention facilitators from partnering service centres was thought to improve recruitment and retention, cost-effectiveness and social interactions compared to professional-led interventions. Seven adults with experience of homelessness (three females, four males, mean age 39 years, range 18-63) were recruited to participate in the intervention. The research protocol comprised completion pre/post of scales [Recovering Quality of Life questionnaire; Working Alliance Inventory-short form revised (WAI-SR)] and focus groups, and WAI-SR and focus groups after sessions 3 and 6.

RESULTS

The intervention and research protocols were feasible, with all participants engaging in all sessions, completing all scales and attending all focus groups. The quantitative data demonstrated the feasibility of obtaining practically useful measures of relevant outcomes. In the four focus groups, the intervention received very favourable feedback.

CONCLUSIONS

This study demonstrated initial feasibility and acceptability of an intervention that places minimal burden on infrastructure and promotes user autonomy. This is an important advance as there is increasing recognition that the challenge of reintegration is as much a psychological and social problem as a housing problem. If effective, this style of intervention may serve as a template for future interventions with similar populations.

1201 Performance Evaluation Of A Novel Contactless Breathing Monitor And Machine Learning Algorithm For Sleep Stage Classification In A Healthy Population

Introduction

Although polysomnography (PSG) remains the gold standard for sleep assessment in a lab setting, non-EEG signals such as respiration and motion are directly affected by sleep stages and can be used for sleep stage prediction. Importantly, these signals can be obtained in a low-cost and unobtrusive manner, allowing for large scale and longitudinal data collection in a home environment. The Circadia C100 System (FDA 510(k) clearance expected Q1 2020) is a novel ‘nearable’ device that uses radar for contactless monitoring of respiration and motion. The current study aims to validate the performance of the associated sleep analysis algorithm.

Methods

A total of 41 nights of sleep data were recorded from 33 healthy participants using the device, alongside PSG. Data were recorded both in a sleep lab and home environment. PSG data were scored by RPSGT-certified technicians. Respiration and movement features were extracted, and machine learning algorithms were developed to perform sleep stage classification and predict sleep metrics. Algorithms were trained and validated on PSG data using cross-validation.

Results

An epoch-by-epoch true positive rate of 56.2%, 79.4%, 55.5% and 72.6% was found for ‘Wake’, ‘REM’, ‘Light’ and ‘Deep’ respectively. No statistical differences in performance were found between home-recorded and lab-recorded contactless data. Mean absolute error of total sleep time (TST), wake after sleep onset (WASO), and sleep efficiency (SE) was 13.2 minutes, 11.3 minutes and 3%, respectively. The contactless monitor was found to outperform both medical grade and clinical grade actigraphy based devices: The Philips Actiwatch Spectrum Plus and the Fitbit Alta HR.

Conclusion

Current results are encouraging and suggest that the contactless monitor could be used for long-term sleep assessment and continuous evaluation of sleep therapy outcomes. Further clinical validation work is ongoing in subjects diagnosed with sleep disorders such as obstructive sleep apnea.

Support

-

Lessons from a publicly funded tier 2 healthy weight programme in Cornwall, UK

BACKGROUND

The UK has one of the highest prevalence rates of obesity worldwide. Public health departments have a duty to provide some obesity treatment and prevention services. With evidence of effective programmes lacking, we investigate lessons learned from a healthy weight programme in Cornwall, UK.

METHODS

Data from the 12-week multi-component adult healthy weight management programme were obtained for 2012-2016. Descriptive statistics and statistical tests were used to describe participants' demographics, health status and anthropometric measures to explore the enrolment and retention of the programme as well as the impact.

RESULTS

A total of 1872 adults were referred into the programme. Overall, 646 completed the programme and, 48.8% achieved the programme's aim of a >3% reduction in weight. Those who completed and met the programme aim tended to have had healthier outcomes at baseline.

CONCLUSIONS

For those who engage with the programme the impact can be meaningful. However, <1% of the population of Cornwall with overweight or obesity enroled in the programme, and those who benefitted most might have been in least need. Providing services that meet the needs of the population is challenging when a variety of services is needed, and the evidence base is poor.

Domiciliary use of transcutaneous electrical stimulation for patients with obstructive sleep apnoea: a conceptual framework for the TESLA home programme

Obstructive sleep apnoea (OSA) is a global health problem of increasing prevalence. Effective treatments are available with continuous positive airway pressure (CPAP) therapy and mandibular advancement devices (MAD). However, there is limited long-term adherence to therapy, as CPAP and MAD require permanent usage to avoid recurrence of the symptoms and adverse ill health. Alternative treatments would aid in the treatment cascade to manage OSA effectively whenever standard therapy has been trialled and failed. Hypoglossal nerve stimulation (HNS), an invasive approach to stimulate the pharyngeal dilator muscles of the upper airway during sleep, has been approved for the treatment of OSA by several healthcare systems in recent years. In parallel to the development of HNS, a non-invasive approach has been developed to deliver electrical stimulation. Transcutaneous electrical stimulation in obstructive sleep apnoea (TESLA) uses non-invasive electrical stimulation to increase neuromuscular tone of the upper airway dilator muscles of patients with OSA during sleep. Data from previous feasibility studies and randomised controlled trials have helped to identify a subgroup of patients who are "responders" to this treatment. However, further investigations are required to assess usability, functionality and task accomplishment of this novel treatment. Consideration of these factors in the study design of future clinical trials will strengthen research methodology and protocols, improve patient related outcome measures and assessments, to optimise this emerging therapeutical option. In this review, we will introduce a conceptual framework for the TESLA home programme highlighting qualitative aspects and outcomes.

Video polysomnographic findings in non-rapid eye movement parasomnia

Although video polysomnography (vPSG) is not routinely recommended for the evaluation of typical cases of non-rapid eye movement (NREM) parasomnias, it can aid diagnosis of unusual cases, other sleep disorders and complicated cases with REM behaviour disorder (RBD), and in differentiating parasomnias from epilepsy. In this study, we aimed to assess vPSG findings in consecutive patients with a clinical diagnosis of NREM-parasomnia covering the whole phenotypic spectrum. Five hundred and twelve patients with a final diagnosis of NREM parasomnia who had undergone vPSG were retrospectively identified. vPSGs were analysed for features of NREM parasomnia and for the presence of other sleep disorders. Two hundred and six (40.0%) patients were clinically diagnosed with sleepwalking, 72 (14.1%) with sleep terrors, 39 (7.6%) with confusional arousals, 15 (2.9%) with sexsomnia, seven (1.4%) with sleep-related eating disorder, 122 (23.8%) with mixed phenotype, and 51 (10.0%) with parasomnia overlap disorder (POD). The vPSG supported the diagnosis of NREM parasomnia in 64.4% of the patients and of POD in 98%. In 28.9% of the patients, obstructive sleep apnea (OSA) or/and periodic limb movements during sleep (PLMS) were identified, most commonly in older, male, sleepy and obese patients. vPSG has a high diagnostic yield in patients with NREM parasomnia and should be routinely performed when there is diagnostic doubt, or in patients where there is a suspicion of OSA and PLMS.

NREM parasomnias: a treatment approach based upon a retrospective case series of 512 patients

Background

Non-REM parasomnias are not uncommon conditions in the general population. Current treatment options are based on small case series and reports. In this study, we aimed to present the clinical experience from a large cohort of patients.

Patients

Five hundred and twelve patients with Non-REM parasomnia or parasomnia overlap disorder (POD), who had undergone a video polysomnography and were exposed to treatment, were retrospectively identified. Treatment outcome was assessed based on patients’ reports, and treatment approach on a locally accepted hierarchy of interventions.

Results

Forty percent of patients were diagnosed with sleepwalking, 23.8% with mixed-phenotype and 10% with POD. Ultimately, 97.2% reported adequate control of their symptoms. Moreover, 60.1% were treated with pharmacotherapy and 32.0% without, consistent across all phenotypes (p = 0.09). Benzodiazepines were the most common drugs prescribed (47.1%, p < 0.05). In the end, 37.7% of our patients were receiving a benzodiazepine as part of their successful treatment, 11.7% an antidepressant, 9.2% a z-drug, and 10.7% melatonin. Finally, 13.2%, 12.1%, and 5.8% of our patients reported good control of their symptoms with sleep hygiene, management of sleep-disordered breathing, and psychological interventions (cognitive behavioral therapy [CBT] or mindfulness-based stress reduction [MBSR]), as monotherapy, respectively.

Conclusion

The treatment approach to effective treatment of the patients with Non-REM parasomnias or POD offering first sleep hygiene advice, next treatment of concurrent sleep disorders and management of other priming factors like stress and anxiety, and lastly pharmacotherapy for Non-REM parasomnia is supported by our results. Non pharmacological interventions were effective in one third of our patients, and CBT/MBSR and melatonin appeared promising new treatments.

•

This study supports a standardised treatment approach in NREM-parasomnias.

•

Pharmacotherapy alone effectively treated two thirds of the patients.

•

One third of the patients were effectively treated without pharmacotherapy.

•

Treatment of sleep apnea and periodic limb movements in sleep is recommended.

•

Melatonin and psychological therapies are promising treatment options.

Restoration of Acutely Thrombosed Arterio-Venous Fistulae by rTPA and Percutaneous Angioplasty

Acute thrombosis in native arterio-venous fistulae (AVF) results in considerable patient morbidity. Interventional radiology (IR) comprising thrombolysis and percutaneous transluminal angioplasty (PTA) is well established in the management of thrombosed polytetrafluoroethylene (PTFE) grafts. However its role in thrombosed AVF is uncertain. We looked retrospectively at the role of IR in re-establishing blood flow in acutely thrombosed AVF.

Between 1992–2000, 21 episodes of acutely thrombosed AVF in 15 patients (9 females; age range 29–80yrs) were referred for intervention. All fistulae were being used for haemodialysis at the time. Diagnosis was established by angiography and thrombolysis with recombinant tissue plasminogen activator (rTPA) was attempted in all patients. Discrete stenoses when present (n=12) were then treated with PTA and resistant or recurrent stenoses were managed by stent insertion (n=3). Patients were then heparinised for 24 hours.

Technical success as defined by radiological patency was achieved in 86% cases. Clinical success i.e. the ability to reuse of the fistula for haemodialysis was achieved in 62% of the interventions, where patency rates at 3 and 6 months were 92% and 69% respectively. Five patients had recurrence of thrombosis >3 months after the primary procedure, 3 had successful re-intervention. Minor local bleeding was the only complication.

Our retrospective study shows rTPA and PTA is successful in the management of acutely thrombosed AVF. We advocate the routine use of IR as a valuable technique for prolonging the life of native AVF in patients on maintenance haemodialysis.

Effectiveness and side-effect profile of stimulant therapy as monotherapy and in combination in the central hypersomnias in clinical practice

Effectiveness and side-effect profile data on pharmacotherapy for daytime sleepiness in central hypersomnias are based largely upon randomized controlled trials. Evidence regarding the use of combination therapy is scant. The aim of this study was to examine the effectiveness and occurrence of drug-related side effects of these drugs in routine clinical practice. Adult patients diagnosed with a central hypersomnia during a 54-month period at a tertiary sleep disorders centre were identified retrospectively. Side effects were recorded at every follow-up visit. A total of 126 patients, with 3275 patient-months of drug exposure, were categorized into narcolepsy type 1 (n = 70), narcolepsy type 2 (n = 47) and idiopathic hypersomnia (n = 9). Modafinil was the most common drug used as a first-line treatment (93%) and in combination therapy (70%). Thirty-nine per cent of the patients demonstrated a complete, 25% partial and 36% a poor response to treatment. Combination treatment improved daytime sleepiness in 55% of the patients with residual symptoms despite monotherapy. Sixty per cent of patients reported side effects, and 30% reported treatment-limiting side effects. Drugs had similar side-effect incidence (P = 0.363) and their side-effect profile met those reported in the literature. Twenty-seven per cent of the patients received combination treatment and had fewer side effects compared to monotherapy (29.4% versus 60%, respectively, P = 0.001). Monotherapy appears to achieve satisfactory symptom control in most patients with central hypersomnia, but significant side effects are common. Combination therapy appears to be a useful and safe option in patients with refractory symptoms.

Urine Toxicology in Adults Evaluated for a Central Hypersomnia and How the Results Modify the Physician's Diagnosis

STUDY OBJECTIVES

Drugs and psychoactive substances can cause sleepiness and when undetected, may lead to over diagnosis of central hypersomnias. We performed urine drug testing using gas chromatography-mass spectrometry in adults undergoing multiple sleep latency testing (MSLT) for a suspected central hypersomnia. We examined how the drug test results modified the treating physician's diagnosis.

METHODS

One hundred eighty-six consecutive patients with a suspected central hypersomnia who underwent clinical assessment, MSLT and urine drug testing by gas chromatography-mass spectrometry were retrospectively studied. Physicians made a diagnosis after clinical assessment and MSLT and were initially blinded to the urine drug test results.

RESULTS

A third of patients assessed for subjective hypersomnia had a positive urine drug test for a substance affecting sleep. Opioids, cannabis, and amphetamines were the commonest drugs detected. Using MSLT, 35 (18.8%) of 186 patients had objective hypersomnia that may have been due to a drug or substance. Drugs or substances may have confounded the MSLT in 11 (20.1%) of 53 patients who fulfilled diagnostic criteria for idiopathic hypersomnia, and 12 (52%) of 23 of those who fulfilled diagnostic criteria for narcolepsy without cataplexy. Of the 75 positive urine drug samples, 61 (81%) were substances or medications not revealed in the physician interview. The treating physician had not suspected drugs or substances as a possible cause of objective hypersomnia in 34 (97%) of the 35 patients.

CONCLUSIONS

Drugs and psychoactive substances can confound the results of the MSLT and when undetected could lead to over diagnosis of central hypersomnias.

An automated curation procedure for addressing chemical errors and inconsistencies in public datasets used in QSAR modelling

The increasing availability of large collections of chemical structures and associated experimental data provides an opportunity to build robust QSAR models for applications in different fields. One common concern is the quality of both the chemical structure information and associated experimental data. Here we describe the development of an automated KNIME workflow to curate and correct errors in the structure and identity of chemicals using the publicly available PHYSPROP physicochemical properties and environmental fate datasets. The workflow first assembles structure-identity pairs using up to four provided chemical identifiers, including chemical name, CASRNs, SMILES, and MolBlock. Problems detected included errors and mismatches in chemical structure formats, identifiers and various structure validation issues, including hypervalency and stereochemistry descriptions. Subsequently, a machine learning procedure was applied to evaluate the impact of this curation process. The performance of QSAR models built on only the highest-quality subset of the original dataset was compared with the larger curated and corrected dataset. The latter showed statistically improved predictive performance. The final workflow was used to curate the full list of PHYSPROP datasets, and is being made publicly available for further usage and integration by the scientific community.

Catathrenia, a REM predominant disorder of arousal?

OBJECTIVES

Catathrenia is an uncommon and poorly understood disorder, characterized by groaning during sleep occurring in tandem with prolonged expiration. Its classification, pathogenesis, and clinical relevance remain debated, substantially due to the limited number of cases reported to date. We report a series of consecutive cases of catathrenia, their clinical and polysomnographic characteristics, and their subsequent management.

METHODS

Consecutive patients with catathrenia who had undergone full polysomnography in our institution over a 5.5-year period were included. Catathrenia events (CEs) were examined in clusters, which formulated catathrenia periods (CPs). The relationships between CPs, sleep stage distribution, electroencephalogram (EEG) arousals, and other sleep parameters were assessed, along with the clinical presentation and management of catathrenic patients.

RESULTS

A total of 427 CPs were identified in 38 patients, 81% arising from rapid eye movement (REM) sleep. EEG arousals preceded or coincided with the onset of 84% of CPs, which were of longer duration than those not associated with an arousal (57.3 ± 56.8 vs. 32.2 ± 29.4 s, p < 0.001). Each CE had a characteristic airflow signal, with inspiration preceding a protracted expiration and a brief more rapid exhalation, followed by deep inspiration. Although the majority of patients were referred on the basis of bed partner complaints, 44.7% complained of daytime sleepiness. Continuous positive airway pressure therapy and sleep-consolidating pharmacotherapy led to subjective improvement, but were limited by poor long-term adherence.

CONCLUSIONS

In the largest series of catathrenia patients reported to date, we found that this rare disorder is characterized by a distinct breathing pattern and arises predominantly from REM sleep, with arousals almost uniformly preceding or coinciding with the onset of CPs.

Regional Metabolic Supply Dependency in Chronic Congestive Heart Failure

We present a 64-year-old man with New York Heart Association (NYHA) Class III chronic congestive heart failure (CHF) who was examined for an alteration in cerebral cortex regional oxygen utilization as reflected by changes in local cerebral metabolic rates for glucose (LCMRglu). LCMRglu was determined by positron emission tomography at baseline and while oxygen delivery (DO2) was optimized during dobutamine infusion. Baseline DO2 was 8.31 mL/min/kg and cardiac output (CO) was 3.4 L/min, whereas oxygen consumption (VO2) measured by respired gas analysis was 3.64 mL/min/kg. At optimal dobutamine effect (7.5 μg/kg/min), DO2 increased to 16.8 mL/min/kg, CO to 7.2 L/min, and VO2MEAS was 3.67 mL/min/kg. Mean percentage Increase in cortical gray matter LCMRglu was 99.4 ± 11.7% (mean ± SD) and was statistically significant ( p < 0.001; Student's paired t-test). Our results demonstrate that the cerebral glucose utilization and therefore oxygen consumption increased parallel with Increases in DO2. This phenomenon is contrary to the conventional concept that cerebral perfusion is strictly autoregulated and that substrate utilization is independent of oxygen delivery.

The use of an online pictorial Epworth Sleepiness Scale in the assessment of age and gender specific differences in excessive daytime sleepiness

BACKGROUND

Excessive daytime sleepiness (EDS) is a non-specific but highly prevalent cardinal symptom of sleep disorders. We hypothesized that with modern media and an online pictorial Epworth Sleepiness Scale (ESS) age and gender specific differences of EDS could be identified on a large scale. This could be helpful in the screening of patients with sleep disorders.

PATIENTS AND METHODS

In 8,098 subjects, age and gender were recorded in addition to an online pictorial ESS (range 0-24 points). The cut-off for EDS (ESS >10 points) was chosen in line with the traditional ESS.

RESULTS

The prevalence of EDS was slightly higher in male subjects (45% vs. 43%, P=0.033). When age was considered, female subjects tended to be sleepier in their 3(rd) and 4(th) lifetime decade (P=0.01 and P=0.003, respectively), whilst male subjects scored significantly higher in their 7(th) decade (P<0.0001); there was a trend to more daytime symptoms with higher age (P for trend <0.001).

CONCLUSIONS

The online pictorial ESS identifies gender differences in EDS and reveals increased levels of sleepiness associated with higher age. The use of modern media facilitates reaching out to the general population to raise awareness of conditions associated with EDS such as sleep apnoea.

HIV research trials versus standard clinics for antiretroviral-naïve patients: the outcomes differ but do the patients?

Exclusion criteria for HIV treatment-naïve drug trials can be stringent and selection bias exists, making it difficult to extrapolate results into the 'real world' clinical situation. We aim to compare the demographics, virological outcomes and psychosocial complexity in adult HIV-infected treatment-naïve patients from our cohort initiating combination antiretroviral therapy (cART) in research trials versus standard clinics. In our unit from 2006 to 2011, 1202 standard clinic and 69 research trial patients initiated cART; every eighth standard clinics patient was included to create a standard clinics:research trials patient ratio of 2:1. Notes were retrospectively reviewed for patient demographics, attendance rates and virological outcomes. Data from 221 antiretroviral-naïve patients starting cART were analysed: 152 standard clinic patients and 69 from research trials. In the research trials group, there was an overrepresentation of men (p = 0.041), men who have sex with men (p < 0.001), patients of white ethnicity (p = 0.01), employed patients (p = 0.01) and patients using excessive alcohol (p = 0.02). There was equal representation of drug use, depression and referral to psychology, psychiatry and social work in both groups. The research trials group at baseline had significantly higher CD4 counts (p < 0.001), lower viral loads (p = 0.01) and more patients achieved undetectable viral loads at three (p < 0.001), six (p < 0.001) and 24 months (p = 0.033). There is a prevailing common preconception that participants in clinical trials are uncomplicated, unlike their 'real-life' counterparts. We demonstrated important similarities in psychosocial complexity as well as differences in demographics and virological outcomes in trial and non-trial patients. Clinicians need to be aware of these discrepancies to ensure the facilitation of a heterogeneous population participating in research trials.

Molecular cloning, characterisation and mRNA expression of the ryanodine receptor from the peach-potato aphid, Myzus persicae

The peach potato aphid, Myzus persicae, is one of the most important agricultural pests of temperate climates. It is mainly controlled through the judicious application of insecticides; however, over time, aphids have developed resistance to many insecticidal classes. The recent introduction of synthetic diamide insecticides, with a novel mode of action, potentially offers new tools to control aphid populations. These diamides act on the ryanodine receptor (RyR), a large endoplasmic calcium release channel. In this study we have cloned cDNAs encoding the complete open reading frame of the RyR from M. persicae. The open reading frame is 15,306 base pairs long and encodes a protein of 5101 amino acids. The aphid RyR shares many of the features of other insect and vertebrate RyRs, including a highly conserved transmembrane region. However, unlike the other RyRs characterised to date, the M. persicae channel does not display alternative splicing at any stage of its developmental cycle, so it cannot generate functional variants of the channel.

Spatial variation in the effects of size and age on reproductive dynamics of common coral trout Plectropomus leopardus

The effects of size and age on reproductive dynamics of common coral trout Plectropomus leopardus populations were compared between coral reefs open or closed (no-take marine reserves) to fishing and among four geographic regions of the Great Barrier Reef (GBR), Australia. The specific reproductive metrics investigated were the sex ratio, the proportion of vitellogenic females and the spawning fraction of local populations. Sex ratios became increasingly male biased with length and age, as expected for a protogyne, but were more male biased in southern regions of the GBR (Mackay and Storm Cay) than in northern regions (Lizard Island and Townsville) across all lengths and ages. The proportion of vitellogenic females also increased with length and age. Female P. leopardus were capable of daily spawning during the spawning season, but on average spawned every 4·3 days. Mature females spawned most frequently on Townsville reserve reefs (every 2·3 days) and Lizard Island fished reefs (every 3·2 days). Females on Mackay reefs open to fishing showed no evidence of spawning over 4 years of sampling, while females on reserve reefs spawned only once every 2-3 months. No effect of length on spawning frequency was detected. Spawning frequency increased with age on Lizard Island fished reefs, declined with age on Storm Cay fished reefs, and declined with age on reserve reefs in all regions. It is hypothesized that the variation in P. leopardus sex ratios and spawning frequency among GBR regions is primarily driven by water temperature, while no-take management zones influence spawning frequency depending on the region in which the reserve is located. Male bias and lack of spawning activity on southern GBR, where densities of adult P. leopardus are highest, suggest that recruits may be supplied from central or northern GBR. Significant regional variation in reproductive traits suggests that a regional approach to management of P. leopardus is appropriate and highlights the need for considering spatial variation in reproduction where reserves are used as fishery or conservation management tools.

Comparison of 7 versus 14 days wrist actigraphy monitoring in a sleep disorders clinic population

Wrist actigraphy is a valid measure to assess sleep and circadian rhythm abnormalities. It is listed in the diagnostic criteria for sleep disorders where single night polysomnography is insufficient (ICSD-2). However, an optimal recording time remains unclear. We hypothesised that seven days would provide sufficient data for analysis, similar to recordings for 14 days. We analysed three consecutive years of actigraphy data obtained within a tertiary sleep referral centre. Data were recorded continuously for two weeks using an AW4 actiwatch (Cambridge NeuroTechnology, Cambridge, UK; Mini Mitter Co, Sunriver, OR). Parameters, including sleep efficiency (SE), sleep latency (SL), sleep fragmentation index (SFI), total sleep time (TST) and wake after sleep onset (WASO) were analysed using GraphPad Prism (Version 5.02, GraphPad Software Inc, San Diego, CA) and classified into week one, week two and an overall average for the duration of 14 days. In addition, two experienced consultants working in the sleep laboratory compared the results of week one versus week two independently, visually analysing the data for circadian rhythmicity and fragmentation of the pattern, allowing calculation of the intraclass correlation coefficient (ICC), κ. The actigraphies of 239 patients (51.9% male; age 42 (16) years) were analysed. There was no difference in SE, SL, SFI or WASO between week one, week two and 14 days average recording. A small difference was found between TST week one (399.9 minutes, 95% CI 389.9-409.9 minutes) and TST week two (388.7 minutes, 95% CI 378.3-399.1 minutes), but not between TST for 14 days average recording (394.3 minutes, 95% CI 384.7-403.9 minutes) and either week. Independent scorers achieved a good agreement in the rhythmicity of the sleep pattern (ICC κ 0.734, p < 0.001) and a low agreement for the fragmentation of the pattern (ICC κ 0.380, p < 0.001). One week of wrist actigraphy recording provides similar data to two week actigraphies, despite subtle differences between the weeks. One week wrist actigraphy could be recommended as standard compared to longer recordings to maximise efficiency of the clinical service. Further studies are required to validate our results in specific clinical subgroups.

Multiple independent emergences of type 2 vaccine-derived polioviruses during a large outbreak in northern Nigeria

Since 2005, a large poliomyelitis outbreak associated with type 2 circulating vaccine-derived poliovirus (cVDPV2) has occurred in northern Nigeria, where immunization coverage with trivalent oral poliovirus vaccine (tOPV) has been low. Phylogenetic analysis of P1/capsid region sequences of isolates from each of the 403 cases reported in 2005 to 2011 resolved the outbreak into 23 independent type 2 vaccine-derived poliovirus (VDPV2) emergences, at least 7 of which established circulating lineage groups. Virus from one emergence (lineage group 2005-8; 361 isolates) was estimated to have circulated for over 6 years. The population of the major cVDPV2 lineage group expanded rapidly in early 2009, fell sharply after two tOPV rounds in mid-2009, and gradually expanded again through 2011. The two major determinants of attenuation of the Sabin 2 oral poliovirus vaccine strain (A481 in the 5'-untranslated region [5'-UTR] and VP1-Ile143) had been replaced in all VDPV2 isolates; most A481 5'-UTR replacements occurred by recombination with other enteroviruses. cVDPV2 isolates representing different lineage groups had biological properties indistinguishable from those of wild polioviruses, including efficient growth in neuron-derived HEK293 cells, the capacity to cause paralytic disease in both humans and PVR-Tg21 transgenic mice, loss of the temperature-sensitive phenotype, and the capacity for sustained person-to-person transmission. We estimate from the poliomyelitis case count and the paralytic case-to-infection ratio for type 2 wild poliovirus infections that ∼700,000 cVDPV2 infections have occurred during the outbreak. The detection of multiple concurrent cVDPV2 outbreaks in northern Nigeria highlights the risks of cVDPV emergence accompanying tOPV use at low rates of coverage in developing countries.

Age estimation and validation for South Pacific albacore Thunnus alalunga

Validated estimates of age are presented for albacore Thunnus alalunga, sampled from a large part of the south-western Pacific Ocean, based on counts of annual opaque growth zones from transverse sections of otoliths. Counts of daily increments were used to estimate the location of the first opaque growth zone, which was completed before the first assumed birthday. The periodicity of opaque zones was estimated by marginal increment analysis and an oxytetracycline mark-recapture experiment. Both validation methods indicated that opaque zones formed over the austral summer and were completed by autumn to winter (April to August). The direct comparison of age estimates obtained from otoliths and dorsal-fin spines of the same fish indicated bias, which was assumed to be due to poor increment clarity and resorption of early growth zones in spines, resulting in imprecise age estimates. As such, age estimates from otoliths are considered to be more accurate than those from spines for T. alalunga. This is consistent with results for a growing number of tropical and temperate tuna Thunnini species. It is recommend that validated counts of annual growth zones from sectioned otoliths is used as the preferred method for estimating age-based parameters for assessment and management advice for these important stocks.

Comparative biology of tropical Lethrinus species (Lethrinidae): challenges for multi-species management

Life-history characteristics of six tropical Lethrinus species sampled from the Great Barrier Reef World Heritage Area were compared. Two species groups were identified based on fork length (LF ): large species with maximum LF > 640 mm (longface emperor Lethrinus olivaceus, yellowlip emperor Lethrinus xanthochilus and spangled emperor Lethrinus nebulosus) and small species with maximum LF < 480 mm (Pacific yellowtail emperor Lethrinus atkinsoni, pink ear emperor Lethrinus lentjan and ornate emperor Lethrinus ornatus). Lifespan was not correlated with LF . Early growth for all species was rapid and similar during the first few years of life, but coefficients of the von Bertalanffy growth function varied considerably among species. Growth also differed between sexes for L. atkinsoni. Reproductive characteristics varied among species, with peak periods of spawning occurring in November to December for L. atkinsoni, July to August for L. nebulous, September to October for L. olivaceus and a protracted season for L. lentjan, although fewer samples were available for the last two species. Sex-specific LF and age distributions and gonad histology of L. lentjan were suggestive of a functional protogynous reproductive pattern, as observed in other lethrinids. Gonad histology indicated non-functional protogynous hermaphroditism for L. atkinsoni and L. nebulosus. The diversity of life histories among these closely related species emphasizes the difficulty in devising single management strategies appropriate for multi-species fisheries and illustrates the importance of understanding species-specific life histories to infer responses to exploitation.

Sleep stage sequence analysis of sleep onset REM periods in the hypersomnias

BACKGROUND

The Multiple Sleep Latency Test (MSLT) remains an important diagnostic tool in the diagnosis of hypersomnias. However, a positive MSLT may be found in other sleep disorders, such as behaviourally induced inadequate sleep syndrome (BIISS). It has been demonstrated that in sleep onset rapid eye movement (SOREM) periods in BIISS, REM sleep tends to arise from stage 2 sleep (non-REM (NREM) 2), rather than stage 1 sleep (NREM1), as in narcolepsy.

METHODS

We performed sleep stage sequence analysis on 127 patients with nocturnal polysomnography and MSLT, including 25 with narcolepsy with cataplexy (N+C), 41 with narcolepsy without cataplexy (N-C), 21 with idiopathic hypersomnia with long sleep time (IHL), 20 with BIISS and 20 with periodic limb movement disorder (PLMD). 537 naps were recorded, containing 176 SOREM periods.

RESULTS

All SOREM periods in the IHL, BIISS and PLMD groups arose from NREM2 sleep, 75% of those in N+C arose from NREM1 and in N-C only 52% arose from NREM1. Within the N-C group, those with SOREM periods all arising from stage 1 had a shorter MSL (p=0.02).

CONCLUSIONS

These results suggest that SOREM periods arising from NREM1 have high sensitivity for the diagnosis of narcolepsy and that SOREM periods from NREM1 are a marker of severity, either of sleepiness or REM instability. Sleep stage sequence analysis of SOREM periods may also aid more accurate phenotyping of the hypersomnias and in particular clarify heterogeneity among patients with narcolepsy without cataplexy.

Alcohol and sleep I: effects on normal sleep

This review provides a qualitative assessment of all known scientific studies on the impact of alcohol ingestion on nocturnal sleep in healthy volunteers. At all dosages, alcohol causes a reduction in sleep onset latency, a more consolidated first half sleep and an increase in sleep disruption in the second half of sleep. The effects on rapid eye movement (REM) sleep in the first half of sleep appear to be dose related with low and moderate doses showing no clear trend on REM sleep in the first half of the night whereas at high doses, REM sleep reduction in the first part of sleep is significant. Total night REM sleep percentage is decreased in the majority of studies at moderate and high doses with no clear trend apparent at low doses. The onset of the first REM sleep period is significantly delayed at all doses and appears to be the most recognizable effect of alcohol on REM sleep followed by the reduction in total night REM sleep. The majority of studies, across dose, age and gender, confirm an increase in slow wave sleep (SWS) in the first half of the night relative to baseline values. The impact of alcohol on SWS in the first half of night appears to be more robust than the effect on REM sleep and does not appear to be an epiphenomenon REM sleep reduction. Total night SWS is increased at high alcohol doses across gender and age groups.

An Investigation into the Use of Stimulant Therapy during Pregnancy

Introduction. A lack of documentation of stimulant use during pregnancy means that doctors have difficulty advising narcoleptic and hypersomnolent patients. Objectives. To investigate the use of stimulant therapy in narcoleptic and hypersomnolent patients during pregnancy. Method. A search of clinic letters at a tertiary sleep clinic identified women who became pregnant whilst receiving stimulant therapy between 01/09/1999 and 18/11/2010. Fifteen patients were included in a telephone survey. Results. There were 20 pregnancies. The reported advice received with regards to stimulant use was variable. In 7 pregnancies, medication was stopped preconceptually: 1 had a cleft palate and an extra digit 6 had good foetal outcomes. In 8 pregnancies, medication was stopped postconceptually: 1 had autism and attention-deficit hyperactivity disorder; 7 had good foetal outcomes. In 5 pregnancies, medication was continued throughout pregnancy: 2 ended in miscarriage; 1 was ectopic; 2 had good foetal outcomes. The most common symptom experienced was debilitating hypersomnolence. Conclusion. There are no standardised guidelines for use of stimulants during pregnancy. Women have significant symptoms during pregnancy for which there is an unmet clinical need. More research is needed into whether medication can be safely continued during pregnancy, and if not, when it should be discontinued. Better standardized advice should be made available.

Volume targeted versus pressure support non-invasive ventilation in patients with super obesity and chronic respiratory failure: a randomised controlled trial

INTRODUCTION

Automatic titration modes of non-invasive ventilation, including average volume assured pressure support (AVAPS), are hybrid technologies that target a set volume by automated adjustment of pressure support (PS). These automated modes could offer potential advantages over fixed level PS, in particular, in patients who are super obese.

METHODS

Consecutive patients with obesity hypoventilation syndrome were enrolled in a two-centre prospective single-blind randomised controlled trial of AVAPS versus fixed-level PS using a strict protocolised setup.

MEASUREMENTS

The primary outcome was change in daytime arterial PCO(2) (PaCO(2)) at 3 months. Body composition, physical activity (7-day actigraphy) and health-related quality of life (severe respiratory insufficiency questionnaire, SRI) were secondary outcome measures.

RESULTS

50 patients (body mass index 50±7 kg/m(2); 55±11 years; 53% men) were enrolled with a mean PaCO(2) of 6.9±0.8 kPa and SRI of 53±17. 46 patients (23 AVAPS and 23 PS) completed the trial. At 3 months, improvements in PaCO(2) were observed in both groups (AVAPS 0.6 kPa, 95% CI 0.2 to 1.1, p<0.01 vs PS 0.6 kPa, 95% CI 0.1 to 1.1, p=0.02) but no between-group difference (-0.1 kPa, 95% CI -0.7 to 0.6, p=0.87). SRI also improved in both groups (AVAPS 11, 95% CI 6 to 17, p<0.001 vs PS 7, 95% CI 1 to 12, p=0.02; between groups 5, 95% CI -3 to 12, p=0.21). Secondary analysis of both groups combined showed improvements in daytime physical activity that correlated with reduction in fat mass (r=0.48; p=0.01).

CONCLUSION

The study demonstrated no differences between automated AVAPS mode and fixed-level PS mode using a strict protocolised setup in patients who were super obese. The data suggest that the management of sleep-disordered breathing may enhance daytime activity and promote weight loss in super-obese patients.

Ultra-low exposure to α-7 nicotinic acetylcholine receptor partial agonists elicits an improvement in cognition that corresponds with an increase in α-7 receptor expression in rodents: implications for low dose clinical efficacy

Αlpha-7 neuronal nicotinic receptors (NNRs) are considered targets for cognitive enhancement in schizophrenia and Alzheimer's disease. AZD0328 is an alpha-7 NNR partial agonist that enhances cognition in rodents and nonhuman primates at sub-microgram to microgram doses. We hypothesized that increased expression of the alpha-7 receptor contributes to this beneficial activity at low doses and tested this by examining the effect of AZD0328 using in vivo and ex vivo binding, RT-PCR and cognitive function in rodents. AZD0328 (0.00178 mg/kg) was subcutaneously administered to mice 4, 24, 48 and 72 hours prior to testing in novel object recognition and produced a significant increase in cognition at 4, 24 and 48 h post-dosing. In vivo binding was examined in rat brain using [(3)H]AZ11637326 and there was a dose-dependent reduction in receptor binding at higher doses of AZD0328 (0.001-3 mg/kg), and a second alpha-7 partial agonist, SSR180711 (0.01-30 mg/kg). Lower doses of both compounds (0.0001 mg/kg) produced a significant increase in binding of [(3)H]AZ11637326. Ex vivo binding using [(125)I]-α-bungarotoxin, showed a significant increase in receptor number (B(max.)) in the frontal cortex or hippocampus with no significant effect on receptor affinity (K(d)) 2 h post administration of AZD0328. [(3)H]AZ11637326 administered 1.5 h following AZD0328 produced a significant increase in specific binding in rat brain regions. We found that the effect on receptor number was long-lasting, with [(125)I]-α-bungarotoxin binding increased in rats given AZD0328 for 2-48 h, but this was not accompanied by increased mRNA synthesis. SSR180711 produced a similar increase in B(max.) and specific binding with no effect on K(d). Therefore, trace dose of alpha-7 partial agonists has rapid onset and produces a profound, sustained effect on novel object recognition in mice that corresponds by dose to an increase in receptor number in rat brain. These findings provide an explanation for the acute and sustained benefit of alpha-7 receptor activation in working memory in nonhuman primates and guidance for drug development initiatives and treatment regimens for nicotinic partial agonists.

Outbreak of type 2 vaccine-derived poliovirus in Nigeria: emergence and widespread circulation in an underimmunized population

Wild poliovirus has remained endemic in northern Nigeria because of low coverage achieved in the routine immunization program and in supplementary immunization activities (SIAs). An outbreak of infection involving 315 cases of type 2 circulating vaccine-derived poliovirus (cVDPV2; >1% divergent from Sabin 2) occurred during July 2005-June 2010, a period when 23 of 34 SIAs used monovalent or bivalent oral poliovirus vaccine (OPV) lacking Sabin 2. In addition, 21 "pre-VDPV2" (0.5%-1.0% divergent) cases occurred during this period. Both cVDPV and pre-VDPV cases were clinically indistinguishable from cases due to wild poliovirus. The monthly incidence of cases increased sharply in early 2009, as more children aged without trivalent OPV SIAs. Cumulative state incidence of pre-VDPV2/cVDPV2 was correlated with low childhood immunization against poliovirus type 2 assessed by various means. Strengthened routine immunization programs in countries with suboptimal coverage and balanced use of OPV formulations in SIAs are necessary to minimize risks of VDPV emergence and circulation.

Practical guidelines for routine intensity-modulated radiotherapy verification: pre-treatment verification with portal dosimetry and treatment verification with in vivo dosimetry

The purpose of this work is to provide guidelines for the routine use of portal dosimetry and in vivo diode measurements to verify intensity-modulated radiotherapy (IMRT) treatments. To achieve tolerance levels that are sensitive enough to intercept problems, both the portal dosimetry and the in vivo procedure must be optimised. Portal dosimetry was improved by the introduction of an optimised two-dimensional (2D) profile correction, which also accounted for the effect of backscatter from the R-arm. The scaled score, indicating the fraction of points not meeting the desired gamma evaluation criteria within the field opening, was determined as the parameter of interest. Using gamma criteria of a 3% dose difference and 3 mm distance to agreement, a "scaled score" threshold value of 1.5% was chosen to indicate excessive tongue and groove and other problems. The pre-treatment portal dosimetry quality assurance (QA) does not encompass verification of the patient dose calculation or position, and so it is complemented by in vivo diode measurements. Diode positioning is crucial in IMRT, and so we describe a method for diode positioning at any suitable point. We achieved 95% of IMRT field measurements within ±5% and 99% within ±8%, with improved accuracy being achieved over time owing to better positioning. Although the careful preparation and setup of the diode measurements can be time-consuming, this is compensated for by the time efficiency of the optimised procedure. Both methods are now easily absorbed into the routine work of the department.

Test of recrudescence hypothesis for overwintering of West Nile virus in gray catbirds

West Nile virus is a pathogen of concern for both human and wildlife health. Although many aspects of the ecology of West Nile virus are well understood, the mechanisms by which this and similar mosquito-borne viruses overwinter and become reinitiated each spring in temperate regions is not known. A thorough understanding of this mechanism is crucial to risk assessment and development of control strategies. One of the hypotheses to explain the mechanism by which this virus persists from year to year is the spring recrudescence of latent virus in avian reservoir hosts. Stress-related immunosuppression is implicated in the recrudescence of latent viruses in birds. We tested the spring recrudescence hypothesis in a controlled laboratory experiment using hatching-year gray catbirds (Dumatella carolinensis) captured in northern Ohio (July-August 2006). Catbirds (n = 60) were experimentally infected (September 2006) and later examined for the effects of immunosuppression through exogenous hormones and artificially induced migratory disposition. We found no effect of either testosterone or migratory behavior on infection status in any of the treatment birds. Moreover, we detected no viral RNA in the kidney, spleen, brain, or liver upon necropsy at 24 wk postinfection.

Effect of informational internet web pages on patients' decision-making: randomised controlled trial regarding choice of spinal or general anaesthesia for orthopaedic surgery

This study explored whether patients' preference for particular types of anaesthesia could be influenced pre-operatively by giving them the addresses of various relevant websites. Patients at an orthopaedic pre-assessment education clinic completed a questionnaire, which included a short multiple-choice general knowledge quiz about anaesthesia, and also questioned them as to their choice of anaesthesia (general or neuraxial). Patients were randomly assigned to intervention or control groups. Intervention group members were given the addresses of three relevant anaesthesia and health related websites to access at home. All patients were asked to complete the questionnaires on a second occasion, before surgery. Initially, most patients stated a preference for general anaesthesia. Subsequently, the intervention group altered their preference towards neuraxial anaesthesia compared to the control group (p < or = 0.0001). The increase in median (IQR [range]) anaesthesia knowledge test score was greater in the intervention group (from 10.0 (9.0-12.0 [5.0-14.0]) to 13.0 (11.0-14.0 [6.0-14.0])) than in the control group (from 10.0 (9.0-11.5 [3.0-13.0]) to 11.0 (9.0-12.0 [4.0-14.0]); p = 0.0068).

The size of the spleen by magnetic resonance imaging in patients with cystic fibrosis; with and without diabetes--a novel observational study

BACKGROUND

Magnetic resonance imaging (MRI) has been shown to be a useful tool to evaluate the volume of the pancreas. There is currently no information about the size of the spleen in cystic fibrosis (CF) patients.

PATIENTS AND METHODS

We investigated 51 adult volunteers: 28 pancreatic insufficient CF patients [13 with CF-related diabetes (CFRD) and 15 non-diabetic] and 23 male non-CF patients [12 with type 1 diabetes mellitus (T1DM) and 11 healthy control subjects]. Patients with known liver cirrhosis or portal hypertension were excluded. The size of the spleen was measured in all subjects by an investigator unaware of patients' clinical status. For comparison of spleen size in the four study groups only male CF patients were included. For CF patients, spleen size was compared with forced expiratory volume in 1 s (FEV(1)), body mass index (BMI), total number of days of intravenous (IV) antibiotic treatment for pulmonary exacerbations in year previous to study, levels of circulating white blood cells, glycosylated haemoglobin A1c (HbA1c), and exocrine function of the pancreas, as assessed by daily requirement of oral lipase.

RESULTS

Amongst the four study groups, spleen size was greatest in the male non-diabetic CF patients (P = 0.01). For CF patients, spleen size was greater in male compared to female patients (P = 0.012). For patients with CFRD, there was an inverse correlation between the spleen size and HbA1c (r = -0.59, P = 0.04) and the daily intake of supplementary lipase (r = -0.63, P = 0.02). The size of the spleen in patients with CFRD, but not in CF patients without CFRD, inversely correlated with the days of IV antibiotic treatment received in the year previous to the study (r = -0.67, P = 0.012). There was no correlation between spleen size and BMI, FEV1 and white blood cell counts in any group.

CONCLUSION

On MRI, the spleen size was greatest in male non-diabetic CF patients in comparison with other groups. The size of the spleen in CFRD patients was smaller when diabetes was poorly controlled, when exocrine pancreatic function was greatly impaired and in those with greater need for IV antibiotics in the year prior to the study.

Superconductivity in CuxBi2Se3 and its implications for pairing in the undoped topological insulator

Bi2Se3 is one of a handful of known topological insulators. Here we show that copper intercalation in the van der Waals gaps between the Bi2Se3 layers, yielding an electron concentration of approximately 2x10{20} cm{-3}, results in superconductivity at 3.8 K in CuxBi2Se3 for 0.12<or=x<or=0.15. This demonstrates that Cooper pairing is possible in Bi2Se3 at accessible temperatures, with implications for studying the physics of topological insulators and potential devices.