Spatial and temporal control of lysis by the lambda holin

The infection cycle of phage λ terminates in lysis mediated by three types of lysis proteins, each disrupting a layer in the bacterial envelope: the S105 holin, the R endolysin, and the Rz/Rz1 spanin complex targeting the inner membrane, cell wall or peptidoglycan, and the outer membrane, respectively. Video microscopy has shown that in most infections, lysis occurs as a sudden, explosive event at a cell pole, such that the initial product is a less refractile ghost that retains rod-shaped morphology. Here, we investigate the molecular basis of polar lysis using time-lapse fluorescence microscopy. The results indicate that the holin determines the morphology of lysis by suddenly forming two-dimensional rafts at the poles about 100 s prior to lysis. Given the physiological and biochemical similarities between the lambda holin and other class I holins, dynamic redistribution and sudden concentration may be common features of holins, probably reflecting the fitness advantage of all-or-nothing lysis regulation.IMPORTANCEIn this study, we use fluorescent video microscopy to track -green fluorescent protein (GFP)-labeled holin in the minutes prior to phage lysis. Our work contextualizes prior genetic and biochemical data, showing when hole formation starts and where holin oligomers form in relation to the site of lytic rupture. Furthermore, prior work showed that the morphology of lambda-infected cells is characterized by an explosive event starting at the cell pole; however, the basis for this was not clear. This study shows that holin most often oligomerizes at cell poles and that the site of the oligomerization is spatially correlated with the site of lytic blowout. Therefore, the holin is the key contributor to polar lysis morphology for phage lambda.

Behaviour regulation and the role of mental health in non-alcoholic fatty liver disease

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease in wealthy societies, and is responsible for a significant rise in liver morbidity and mortality. Current treatments prioritise lifestyle interventions, predominantly diet and exercise management, but patients frequently fail to make the necessary behavioural adjustments. The current study seeks to identify those factors which influence patients' behaviour with respect to adherence to treatment regimes.

METHODS

Novel areas of interest were investigated; locus of control, behavioural regulation and a range of mental health measures, due to their links to either poor lifestyle choices or abnormal eating as identified in previous literature. Data was gathered using self-report questionnaires, from 96 participants, who were split into three groups, NAFLD patients, non-NAFLD liver disease patients and healthy controls RESULTS: Data was analysed using a MANOVA, and followed up with a Tukey post-hoc test. Three factors were found to be significant by group; cognitive restraint, uncontrolled eating and SAPAS score (a measure of personality disorders). An association between personality disorders and NAFLD was identified.

CONCLUSION

It is suggested that NAFLD patients are screened for personality disorders and, if identified, treated prior to the commencement of diet and exercise management.

Global survival trends for brain tumors, by histology: analysis of individual records for 556,237 adults diagnosed in 59 countries during 2000-2014 (CONCORD-3)

BACKGROUND

Survival is a key metric of the effectiveness of a health system in managing cancer. We set out to provide a comprehensive examination of worldwide variation and trends in survival from brain tumors in adults, by histology.

METHODS

We analyzed individual data for adults (15-99 years) diagnosed with a brain tumor (ICD-O-3 topography code C71) during 2000-2014, regardless of tumor behavior. Data underwent a 3-phase quality control as part of CONCORD-3. We estimated net survival for 11 histology groups, using the unbiased nonparametric Pohar Perme estimator.

RESULTS

The study included 556,237 adults. In 2010-2014, the global range in age-standardized 5-year net survival for the most common sub-types was broad: in the range 20%-38% for diffuse and anaplastic astrocytoma, from 4% to 17% for glioblastoma, and between 32% and 69% for oligodendroglioma. For patients with glioblastoma, the largest gains in survival occurred between 2000-2004 and 2005-2009. These improvements were more noticeable among adults diagnosed aged 40-70 years than among younger adults.

CONCLUSIONS

To the best of our knowledge, this study provides the largest account to date of global trends in population-based survival for brain tumors by histology in adults. We have highlighted remarkable gains in 5-year survival from glioblastoma since 2005, providing large-scale empirical evidence on the uptake of chemoradiation at population level. Worldwide, survival improvements have been extensive, but some countries still lag behind. Our findings may help clinicians involved in national and international tumor pathway boards to promote initiatives aimed at more extensive implementation of clinical guidelines.

Oral fluoroquinolones and risk of aortic dissection and aortic aneurysm: a nationwide nested case-control study

Background

Oral fluoroquinolones are commonly prescribed antibiotics. Observational studies have shown an association between fluoroquinolone-use and subsequent risk of aortic aneurysm (AA) and aortic dissection (AD) due to a potential collagen degrading effect of fluoroquinolones.

Purpose

To investigate if fluoroquinolone-use was associated with increased rates of AA or AD in patients without known aortic disease. Secondly, to investigate if fluoroquinolone-use was associated with increased all-cause mortality and aortic interventions in high-risk patients with known aortic disease.

Methods

We used a nested case-control study design in which individuals aged 30–100 years from 2003 to 2018 were included from Danish nationwide registers. Exclusion criteria were bicuspid aortic valve, coarctation of the aorta, and connective tissue disease. A main cohort and a secondary high-risk cohort were defined. The main cohort comprised patients without history of AA/AD in which two case definitions were used: 1) A broad case definition of first-time AA/AD. 2) A severe case definition of ruptured AA/AD. The high-risk cohort comprised patients surviving index AA/AD admission in which cases were defined as all-cause mortality and aortic interventions.

Cases were matched on age, sex, and year of inclusion in a 1:30 ratio with controls. For the main cohort, a potential dose-response effect was investigated using groups of cumulative defined daily doses (cDDD) of fluoroquinolones. Hazard ratios (HR) with 95% confidence intervals (CI) for fluoroquinolone-use compared with amoxicillin as an active comparator were obtained from time-dependent Cox regression models using multiple exposure windows.

Results

The main cohort comprised 4.81 million individuals with 43,280 cases. Short-term 30-day, intermediate-term 90-day, and long-term 1-year fluoroquinolone use were all not associated with AA/AD (30-day HR 1.18 [95% CI: 0.84 to 1.66]; 90-day HR 1.12 [95% CI 0.96 to 1.30]; 1-year HR 1.00 [95% CI 0.93 to 1.07]). Using a severe case definition of ruptured AA/AD yielded comparable results. For the dose-response analysis, increasing cDDD did not confer increased rates of AA/AD (1–5 cDDD: Reference group; 6–10 cDDD: HR 1.03 [95% CI: 0.87 to 1.23]; >10 cDDD: HR 1.00 [95% CI 0.83 to 1.29]) (Figure 1).

The secondary high-risk cohort included 20,195 patients surviving index admission with 9,183 cases of all-cause mortality and 1,768 cases of aortic interventions. The 30-day HR for all-cause mortality was 1.21 (95% CI 0.92 to 1.60) and the 60-day HR 1.06 (95% CI 0.89 to 1.26). No association with aortic interventions was found either (Figure 2).

Conclusion

Fluroquinolone-use was not associated with AA/AD. Furthermore, fluoroquinolone-use was not associated with all-cause mortality or aortic interventions in potentially susceptible patients with known aortic disease. These findings do not support an increased risk of AA/AD with fluoroquinolone-use.

Funding Acknowledgement

Type of funding sources: None.

Risk of heart failure following short-term non-steroidal anti-inflammatory drug use in patients with type 2 diabetes mellitus

Background

Fluid retention is a known but underappreciated side-effect of non-steroidal anti-inflammatory drug (NSAID) use. As type 2 diabetes mellitus (T2DM) has been linked to both subclinical cardiomyopathy and a decline in kidney function, short-term NSAID use could lead to subsequently development of heart failure (HF) due to aberrations in fluid balances.

Purpose

We investigated associations between short-term NSAID use and the risk of HF in a nationwide cohort of patients with T2DM.

Methods

Using nationwide Danish registers, we identified patients diagnosed with T2DM during 1998–2018. Follow-up began 120 days after first-time T2DM diagnosis among patients without prior heart failure or a rheumatological diagnosis indicating long-term NSAID use.

To describe use of NSAID among patients with T2DM, we reported proportions of patients claiming at least 1, 2, 3 or 4 prescriptions of NSAID within one year of start of follow-up. We investigated associations between use of NSAIDs (celecoxib, diclofenac, ibuprofen and naproxen) and new-onset HF hospitalizations using a case-crossover design with 28-day exposure windows and reported odds ratios (OR) with 95% confidence intervals (CI). The case-crossover design uses each individual as his or her own control making it suitable to study the effect of short-term exposure on immediate events while mitigating unmeasured confounding. Sensitivity analyses using exposure windows of 14 and 42 days were performed as well.

Results

A total of 334,950 patients with T2DM was included (47.7% female, median age of 61 [interquartile range 50–70]). Celecoxib and naproxen were rarely used; on the contrary, prescriptions of diclofenac and ibuprofen were claimed at least once within one year from the beginning of follow-up by 4.9% and 15.5% of patients, respectively–0.9% and 2.7% claimed at least four prescriptions (Figure 1).

The risk of new-onset HF hospitalization was increased following use of diclofenac or ibuprofen with corresponding ORs of 1.3 (95% CI 1.0 to 1.7) and 1.3 (95% CI 1.1 to 1.5) using 28-day exposure windows. An increased risk following use of celecoxib or naproxen was not found (Figure 2).

Conclusion

NSAIDs diclofenac and ibuprofen were both widely used and associated with an increased risk of new-onset HF hospitalization in patients with T2DM. This suggests a previously unknown and serious, clinically relevant concern of NSAID use in patients with T2DM.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Ib Mogens Kristiansens Almene FondHelsefonden

Cardiovascular risk following cannabinoid treatment for patients with chronic pain

Background

Treatment with medical cannabis for chronic pain is in popular demand, and a rising number of countries allow physicians to prescribe medical cannabis for pain management. However, data on drug-safety is scarce. Studies have showed a risk of cardiovascular side effects following use of recreational cannabis warranting further investigations into the safety of prescribing medical cannabis.

Purpose

We investigated risk of new-onset arrhythmias (tachy- or bradyarrhythmia and conduction disorders), acute coronary syndrome (ACS) and heart failure (HF) following use of prescribed medical cannabis compared with no use in a nationwide cohort of patients with chronic pain.

Methods

Using nationwide Danish registers, a cohort of patients with chronic pain and without prior history of arrhythmias, ACS, HF or prescribed medical cannabis (cannabinoid, cannabidiol or dronabinol) use were followed from 2018–2021. Any patient from the cohort initiating first-time treatment with medical cannabis was identified and matched 1:10 to corresponding controls within the cohort using incidence density sampling. Matching parameters were age group, sex, and chronic pain diagnosis. Follow-up was initiated at the date of the first claimed prescription of medical cannabis or the corresponding date among controls. We reported 180-day standardized absolute risks (AR) with 95% confidence intervals (CI) and risk ratios (RR) from fitted multivariable logistic regression models comparing patients exposed to medical cannabis with patients not exposed. Separate analyses for each chronic pain group were conducted as well.

Results

Among 1.6 million patients with chronic pain, 4,562 patients claimed at least one prescription of medical cannabis (exposed) and were each matched to 10 controls (non-exposed). Exposed and non-exposed patients were identical in relation to matching parameters; however, exposed patients were slightly more comorbid, and a larger proportion was concomitantly treated with other pain medication (Table). The risk of new-onset arrhythmia was elevated among exposed patients with 180-day AR of 0.71% (95% CI 0.47%–0.94%) compared with 0.43% (95% CI 0.37%–0.49%) yielding a RR of 1.64 (95% CI 1.04–2.23). The risk of new-onset ACS and HF was not increased comparing exposed to non-exposed with corresponding 180-day ARs of 0.13% (95% CI 0.03%-0.23%) vs 0.11% (95% CI 0.08%–0.14% and 0.13% (95% CI 0.03%–0.24%) vs 0.14% (95% CI 0.11%–0.17% (corresponding RRs of 1.2 [95% CI 0.3–2.1] and 0.9 [95% CI 0.2–1.7]) (Figure). Subgroup analyses of each chronic pain group yielded similar results.

Conclusion

In a nationwide cohort of patients with chronic pain, use of medical cannabis was associated with a 64% risk increase of arrhythmias compared with no use. This poses a potential health concern and is vital knowledge for any physician prescribing medical cannabis. Use of medical cannabis was not associated with an elevated risk of ACS or HF.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Ib Mogens Kristiansens Almene FondHelsefonden

25 Unmuting Regional Paediatric Simulation Training Throughout the COVID-19 Pandemic

The National Health Service endured significant strains during the COVID-19 pandemic to the point where all face-to-face training had to be paused. Our team delivers simulation-based training face to face and offers support for those returning to work, stepping up to senior roles and addressing important aspects of general paediatric care such as acute mental health crises and end of life care.

The aim of the study was to deliver our courses virtually without compromising the quality of content.

Initially, we reviewed all scenarios to appraise whether they could be delivered online. Scenarios that involved acute clinical decisions were recorded with the faculty acting as the candidates. This also allowed scripting to ensure that key discussion points could be raised within the debrief. Scenarios mainly involving communication skills with standardized patient role player were retained, and briefs were adapted so that the candidates were aware that the scenarios began when the actor appeared on screen.

Participants were recruited using newsletters and subsequently directed to a website to collate email addresses where invites to the virtual meeting space and pre-course material were sent. The scenarios were combined with contracting rules and links to interactive polls to form a presentation that could be shared on the screen throughout the day. Links to post-course feedback surveys were also included to evaluate participant satisfaction of the course design. From October 2020 to May 2021, we delivered eight virtual teaching sessions to a total of 67 multi-professional candidates ranging from nursing staff, police officers and doctors. Candidates were asked whether the course addressed their learning objectives or whether the course had increased their knowledge and 53 (79%) candidates ‘strongly agreed’ with these statements. Including those who ‘agreed’ with these statements, 66 out of 67 (98%) of the candidates perceived this course addressed their learning outcomes or improved their knowledge. The results from the evaluation of these courses indicate that the adaptation of our face-to-face courses have not impaired the quality of the content and have been beneficial to the targeted audience. Despite the challenges that online teaching can pose, we have overcome these by ensuring that we contract behaviour to ensure psychological safety, included interactive aspects such as live word clouds and polls and used a modality of learning such as the use of role players and modified scenarios to guide debriefs and learning.

Identifying ecological production functions for use in ecosystem services-based environmental risk assessment of chemicals

There is increasing research interest in the application of the ecosystem services (ES) concept in the environmental risk assessment of chemicals to support formulating and operationalising regulatory environmental protection goals and making environmental risk assessment more policy- and value-relevant. This requires connecting ecosystem structure and processes to ecosystem function and henceforth to provision of ecosystem goods and services and their economic valuation. Ecological production functions (EPFs) may help to quantify these connections in a transparent manner and to predict ES provision based on function-related descriptors for service providing species, communities, ecosystems or habitats. We review scientific literature for EPFs to evaluate availability across provisioning and regulation and maintenance services (CICES v5.1 classification). We found quantitative production functions for nearly all ES, often complemented with economic valuation of physical or monetary flows. We studied the service providing units in these EPFs to evaluate the potential for extrapolation of toxicity data for test species obtained from standardised testing to ES provision. A broad taxonomic representation of service providers was established, but quantitative models directly linking standard test species to ES provision were extremely scarce. A pragmatic way to deal with this data gap would be the use of proxies for related taxa and stepwise functional extrapolation to ES provision and valuation, which we conclude possible for most ES. We suggest that EPFs may be used in defining specific protection goals (SPGs), and illustrate, using pollination as an example, the availability of information for the ecological entity and attribute dimensions of SPGs. Twenty-five pollination EPFs were compiled from the literature for biological entities ranging from 'colony' to 'habitat', with 75% referring to 'functional group'. With about equal representation of the attributes 'function', 'abundance' and 'diversity', SPGs for pollination therefore would seem best substantiated by EPFs at the level of functional group.

Usage and risk with phosphodiesterase type 5 inhibitors in male patients with chronic ischemic heart disease on oral organic nitrates

Background

Combining oral organic nitrates (OON) with phosphodiesterase type 5 (PDE5) inhibitors is contraindicated. Growing and liberal use of PDE5 inhibitors for erectile dysfunction among patients with ischemic heart disease (IHD) could pose serious health consequences especially among patients with IHD on OON.

Purpose

We hypothesize that concomitant prescription of OON and PDE5 inhibitors is prevalent and has increased in recent years, and further that possible co-exposure could be associated with an increased risk of ischemic stroke, myocardial infarction (MI) or acute coronary angiography (CAG).

Methods

During 2000–2018, we included all male patients with history of IHD between 18 and 85 years of age from nationwide Danish health registers. Patients with a history of pulmonary hypertension were excluded and not followed up afterwards if they developed the condition during follow-up. From this cohort, we identified an OON treated subgroup defined by two consecutively redeemed prescriptions of OON within 180 days from each other. Further, to become a case or control, patients had to redeem a prescription of OON within 180 days prior to the event or corresponding date among controls.

Temporal trends during 2001–2018 of PDE5 inhibitor use were calculated among all male patients with IHD and the subgroup on OON. Among OON treated patients, we examined associations between PDE5 inhibitor use and risk of ischemic stroke, MI or CAG using a case-crossover design where each individual serves as his/her own control thereby controlling for time-invariant confounding. The case-crossover design compares an individual's exposure in an index period just before the event occurred to a reference period prior to the index period. We investigated periods of varying length (7, 14, 21 and 28 days). To account for possible temporal trends in the use of PDE5 inhibitors, we also conducted a case-time-control analysis using a control group matched on age and calendar year.

Results

We identified 249,541 male patients with IHD (median age 65 years [IQR 56–73]), and a subgroup of 42,073 (17%) on OON treatment (median age 70 years [IQR 62–77]). From 2001 to 2018, the use of PDE5 inhibitors saw a 6-fold increase among all male IHD patients and a 10-fold rise in the subgroup on OON (Figure 1). The risk of ischemic stroke, MI or CAG following exposure to PDE5 inhibitors was not increased in the OON subgroup in neither the case-crossover nor the case-time-control analyses (Figure 2).

Conclusions

The use of PDE5 inhibitors has increased 6-fold since 2001 among male patients with IHD, and 10-fold among patients on OON–notwithstanding an established absolute contraindication. However, we did not find any evidence of an increased risk of ischemic stroke, MI or acute CAG following exposure to PDE5 inhibitors in the OON subgroup. This suggests that patients on OON are adequately informed and comply with the recommended pause in OON medication prior to PDE5 inhibitor use.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Ib Mogens Kristiansens Almene FondandHelsefonden

Gastrointestinal bleeding risk following concomitant treatment with oral glucocorticoids in patients with atrial fibrillation on direct-acting oral anticoagulants

Background

Oral glucocorticoids and direct-acting oral anticoagulants (DOAC) have both been associated with a risk of gastrointestinal (GI) bleeding. However, drug safety, especially regarding the risk of bleeding, in relation to concomitant treatment with oral glucocorticoids and DOACs is insufficiently explored.

Purpose

We aimed to investigate the short-term risk of GI bleeding in patients with atrial fibrillation (AF) following concomitant treatment with DOACs and oral glucocorticoids.

Methods

Register-based, retrospective and nationwide Danish study including patients with AF and on DOAC treatment during 2012–2018. Patients were defined as exposed to oral glucocorticoids from the date of a redeemed prescription and 60 days forward. We associated concomitant treatment with GI bleeding and reported hazard ratios (HR) via a nested case-control design and standardized 60-day absolute risk adjusted for comorbidities using a cohort design. In both analyses, exposed were compared to non-exposed controls matched on age, sex, calendar year, follow-up time and DOAC agent.

Results

We included 98,376 patients (age [interquartile range]: 75 [68– 82], 44% females) with AF on DOAC treatment. The use of oral glucocorticoids among included patients was widespread with 16% redeeming at least one prescription within three years, 4% redeeming at least five (Figure 1A). Lung disease was the most frequent indication (Figure 1B). Concomitant treatment with DOACs and oral glucocorticoids was associated with an increased incidence of GI bleeding (total n=4,946) compared with only DOAC treatment, including a dose-response trend (<20mg daily dose, HR [95% confidence interval (CI)]: 1.64 [1.38–1.95]; ≥20mg daily dose, HR [95% CI]: 2.29 [1.90–2.77]). Likewise, the standardized 60-day absolute risk of GI bleeding from first oral glucocorticoid exposure was increased compared with non-exposed (Figure 2).

Conclusion

Caution should be exercised when prescribing even short-term oral glucocorticoid treatment for DOAC treated patients, most notably in high doses and for patients with elevated bleeding risk.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Ib Mogens Kristiansens Almene FondandHelsefonden

Obesity bias and stigma, attitudes and beliefs among entry-level physiotherapy students in the Republic of Ireland: a cross sectional study

OBJECTIVE

To explore entry-level physiotherapy students' attitudes and beliefs relating to weight bias and stigmatisation in healthcare.

DESIGN

Cross sectional survey of physiotherapy students.

METHODS

All final year physiotherapy students (n = 215) enrolled in entry-level physiotherapy programmes in the Republic of Ireland were invited to participate. Each received a questionnaire, consisting of 72 questions, within four key sections. Descriptive statistics and frequencies were used to analyse the data.

RESULTS

A response rate of 83% (179/215) was achieved. Whilst physiotherapy students, overall, had a positive attitude towards people with obesity, 29% had a negative attitude towards people with obesity, 24% had a negative attitude towards managing this population and most (74%) believed obesity was caused by behavioural and individual factors. Over one third of students (35%) reported that they would not be confident in managing patients with obesity and more than half (54%) felt treating patients with obesity was not worthwhile.

CONCLUSION

This study provides preliminary findings to suggest that weight stigma-reduction efforts are warranted for physiotherapy students. Helping students to understand that obesity is a complex, chronic condition with multiple aspects requiring a multi-faceted approach to its management might be the first step towards dispelling these negative attitudes towards patients living with obesity. Inclusion of a formal obesity curriculum should perhaps now be part of the contemporary physiotherapy students' education.

Effect of beta blocker therapy following myocardial infarction in optimally treated patients in the reperfusion era – a Danish, nationwide, and registry-based cohort study

Background and purpose

European and American cardiovascular treatment guidelines advocate for two and three years of beta-blocker (BB) treatment, respectively, following myocardial infarction (MI). Contemporary continued efficacy of longer-term use of BB in stable coronary artery disease has been debated in the era of reperfusion. We aim to investigate the cardio-protective effect associated with BB treatment in patients following MI.

Methods

Using nationwide databases, we included optimally treated patients with first-time MI undergoing coronary angiography (CAG) or percutaneous coronary intervention (PCI) during admission and treated with both acetyl-salicylic acid and statins post-discharge between 2003 and 2017. Patients with prior history of MI, BB use or any other possible indication or contraindication for BB treatment (heart failure, cardiac arrhythmias or procedures, asthma, chronic obstructive pulmonary disease) were excluded. Continued BB exposure was defined as two redeemed prescriptions within the first 180 days following discharge, one of them within 90 days. Follow-up began 180 days following discharge in patients alive and with no further cardiovascular events or procedures prior. Patients were followed for a maximum of three years. Primary outcomes were cardiovascular death and recurrent MI in patients stratified by BB treatment using adjusted Cox regression models.

Results

A total of 27,068 patients optimally treated for MI were included (57% acute PCI, 26% sub-acute PCI, 17% CAG without intervention). At study start 180 days following MI, 79% of the patients were on BB treatment (median age 61 years, 75% male) and 21% were not (median age 62 years, 69% male). Cumulative incidence of cardiovascular death and recurrent MI did not differ significantly comparing patients on BB treatment with patients not on BB treatment (Figure). In multivariable analyses, BB treatment was associated with a similar risk of cardiovascular death and recurrent MI compared to the patients not receiving BB treatment (hazard ratios with [95% confidence intervals] correspondingly; 0.89 [0.68–1.17] and 1.02 [0.89–1.18]) (Figure 1). When stratifying the cohort according to calendar year and type of procedure during admission, we found similar results as the main analysis. No interaction for sex was found.

Conclusions

In this nationwide cohort study of optimally treated patients following MI at 180 days in the reperfusion era, we found a very good prognosis with only 1.2% suffering cardiovascular death and 4.7% suffering a recurrent MI within three years. In total 79% of patients were receiving BB treatment, but we found no difference suggesting BB to be associated with an improved cardiovascular prognosis. These findings challenge current clinical practice and guideline recommendation, suggesting that the role of long-term BB use may be obsolete among optimally treated MI patients. Further investigations, preferably a randomized trial, are warranted.

Figure 1

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Ib Mogens Kristiansens Almene Fond, Snedkermester Sophus Jacobsen og Hustru Astrid Jacobsens Fond

Structurally Related Scaling Behavior in Ionic Systems

We examine the density scaling properties of two ionic materials, a classic aprotic low molecular weight ionic liquid, 1-butyl-3-methylimidazolium bis(perfluoroethylsulfonyl)imide ([BMIm][BETI]), and a polymeric ionic liquid, poly(3-methyl-1,2,3-triazolium bis(trifluoromethylsulfonyl)imide) (TPIL). Density scaling is known to apply rigorously to simple liquids lacking specific intermolecular associations such as hydrogen bonds. Previous work has found that ionic liquids conform to density scaling over limited ranges of temperature and pressure. In this work, we find that the dc-conductivity of [BMIm][BETI] accurately scales for density changes of 17%; however, there is a departure from scaling for TPIL for even more modest variations of temperature and pressure. The entropy of both ionic samples conforms to density scaling only if the scaling exponent is allowed to vary linearly with the magnitude of the entropy.

A-27 Stroop Color-Word Interference Test in Alcohol Use Disorder

Objective

Poor inhibitory control is a characteristic of Alcohol Use Disorder (AUD) that might be associated with worse treatment outcomes because of its contribution to the likelihood of relapse. One valid and efficient tool to examine inhibitory control is the Stroop Color-Word Interference Test (Stroop inhibition). The purpose of this meta-analysis was to examine the consistency of findings on the Stroop inhibition subtest and its relationship to length of use and duration of abstinence in AUD.

Data Selection

Three researchers independently searched nine databases (e.g., PsycINFO, Pubmed, ProceedingsFirst), extracted required data, and calculated effect sizes. Inclusion criteria identified studies that had (a) compared participants with AUD to healthy controls and (b) matched groups on either age, education, or IQ. Studies were excluded if participants were reported to have Axis I diagnoses (other than AUD) or comorbidities known to impact neuropsychological functioning. Twelve articles were coded and analyzed for the current study.

Data Synthesis

Studies comparing AUD to controls showed a medium statistically significant effect size (g = 0.355, p < 0.001) with no heterogeneity (I2 = 0). Length of use and duration of abstinence did not predict effect sizes.

Conclusions

The Stroop inhibition measure distinguishes between AUD participants and controls. Given the robustness of this finding, the lack of heterogeneity among studies, and the extensive past use of the Stroop to measure inhibitory control; this test should be considered when examining AUD patients. This is especially important when patients exhibit poor inhibition in daily functioning.

A-17 Category Test performance in individuals with alcohol versus methamphetamine dependence

Objective

The Category Test (CT) has consistently been found to be sensitive at detecting the effects of alcohol on the brain. However, this test has not been as widely used in examining the effects of methamphetamine. The current meta-analysis compared effect sizes of studies that have examined performance on the CT in alcohol versus methamphetamine dependent participants.

Data selection

Three researchers independently searched nine databases (e.g., PsycINFO, Pubmed, ProceedingsFirst), extracted required data, and calculated effect sizes. Inclusion criteria identified studies that had (a) compared alcohol or methamphetamine dependent groups to healthy controls and (b) matched groups on either age, education, or IQ (at least 2 out of 3). Studies were excluded if participants were reported to have Axis I diagnoses (other than alcohol or methamphetamine dependence) or comorbidities known to impact neuropsychological functioning. Sixteen articles were coded and analyzed for the current study.

Data synthesis

Alcohol studies showed a large effect size (g = 0.745, p < 0.001) while methamphetamine studies evidenced a moderate effect size (g = 0.406, p = 0.001); both without statistically significant heterogeneity (I2 = 0). Subgroup analysis revealed a statistically significant difference between the effect sizes from alcohol versus methamphetamine studies (Q-between = 5.647, p = 0.017).

Conclusions

The CT is sensitive to the effects of both alcohol and methamphetamine and should be considered when examining dependent patients who might exhibit problem solving, concept formation, and set loss difficulties in everyday living.

Obesity in acute alcoholic hepatitis increases morbidity and mortality

BACKGROUND

Alcohol and obesity synergise to increase the risk of liver-related mortality. We examined the influence of adiposity on clinical outcomes in alcoholic hepatitis (AH) and the underlying inflammatory crosstalk between adipose tissue (AT) and the liver.

METHODS

A cohort of 233 patients with AH from the UK and USA provided data to analyse the effects of obesity in AH. Body mass index was corrected for the severity of ascites, termed cBMI. Inflammatory and metabolic profiling was undertaken by proteome analysis of human serum samples. The effect of alcohol on adipose tissue and CXCL11 expression was studied in 3 T3-derived adipocytes and in mice using the high-fat diet-plus-binge ethanol model.

FINDINGS

Obesity was common amongst patients with AH, seen in 19% of individuals. Obesity (HR 2.22, 95%CI 1.1-4.3, p = .022) and underweight (HR 2.38, 1.00-5.6, p = .049) were independently associated with mortality at 3 months. Proteome analysis demonstrated multiple metabolic and inflammatory factors differentially expressed in obese AH verse lean AH, with CXCL11 being the most elevated factor in obese AH. In vitro analysis of cultured adipocytes and in vivo analysis of mouse models showed that alcohol induced CXCL11 expression in AT, but not in liver.

INTERPRETATION

Obesity is common in AH and associated with a greater than two-fold increase in short-term mortality. Obese AH is associated with a different inflammatory phenotype, with the greatest elevation in CXCL11. These data confirm that adiposity is clinically important in acute alcohol-related liver disease and illustrate the adipose-liver inflammatory axis in AH. FUND: This work was supported in part by an EASL Sheila Sherlock Physician Scientist Fellowship. The funder played no role in gathering or analysing data or writing the manuscript. This paper presents independent research supported by the NIHR Birmingham Biomedical Research Centre at the University Hospitals Birmingham NHS Foundation Trust and the University of Birmingham. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

Hepatitis C Virus Recurrence Occurs Earlier in Patients Receiving Donation After Circulatory Death Liver Transplant Grafts Compared With Those Receiving Donation After Brainstem Death Grafts

INTRODUCTION

Hepatitis C virus (HCV)-related cirrhosis remains the commonest indication for liver transplantation worldwide, yet few studies have investigated the impact of donation after circulatory death (DCD) graft use on HCV recurrence and patient outcomes. DCD grafts have augmented the limited donor organ pool and reduced wait-list mortality, although concerns regarding graft longevity and patient outcome persist.

METHODS

This was a single-center study of all HCV + adults who underwent DCD liver transplantation between 2004 and 2014. 44 HCV+ patients received DCD grafts, and were matched with 44 HCV+ recipients of donation after brainstem death (DBD) grafts, and their outcomes examined.

RESULTS

The groups were matched for age, sex, and presence of hepatocellular carcinoma; no significant differences were found between the group's donor or recipient characteristics. Paired and unpaired analysis demonstrated that HCV recurrence was more rapid in recipients of DCD organs compared with DBD grafts (408 vs 657 days; P = .006). There were no significant differences in graft survival, patient survival, or rates of biliary complications between the cohorts despite DCD donors being 10 years older on average than those used in other published experience.

CONCLUSIONS

In an era of highly effective direct acting antiviral therapy, rapid HCV recrudescence in grafts from DCD donors should not compromise long-term morbidity or mortality. In the context of rising wait-list mortality, it is prudent to use all available sources to expand the pool of donor organs, and our data support the practice of using extended-criteria DCD grafts based on donor age. Notwithstanding that, clinicians should be aware that HCV recrudescence is more rapid in DCD recipients, and early post-transplant anti-viral therapy is indicated to prevent graft injury.

Genetic Analysis of the Lambda Spanins Rz and Rz1: Identification of Functional Domains

Coliphage lambda proteins Rz and Rz1 are the inner membrane and outer membrane subunits of the spanin complex-a heterotetramer that bridges the periplasm and is essential for the disruption of the outer membrane during phage lysis. Recent evidence suggests the spanin complex functions by fusing the inner and outer membrane. Here, we use a genetics approach to investigate and characterize determinants of spanin function. Because Rz1 is entirely embedded in the +1 reading frame of Rz, the genes were disembedded before using random mutagenesis to construct a library of lysis-defective alleles for both genes. Surprisingly, most of the lysis-defective missense mutants exhibited normal accumulation or localization in vivo, and also were found to be normal for complex formation in vitro Analysis of the distribution and nature of single missense mutations revealed subdomains that resemble key motifs in established membrane-fusion systems, i.e., two coiled-coil domains in Rz, a proline-rich region of Rz1, and flexible linkers in both proteins. When coding sequences are aligned respective to the embedded genetic architecture of Rz1 within Rz, genetically silent domains of Rz1 correspond to mutationally sensitive domains in Rz, and vice versa, suggesting that the modular structure of the two subunits facilitated the evolutionary compression that resulted in the unique embedded gene architecture.

Limonene in exhaled breath is elevated in hepatic encephalopathy

Breath samples were taken from 31 patients with liver disease and 30 controls in a clinical setting and proton transfer reaction quadrupole mass spectrometry (PTR-Quad-MS) used to measure the concentration of volatile organic compounds (VOCs). All patients had cirrhosis of various etiologies, with some also suffering from hepatocellular cancer (HCC) and/or hepatic encephalopathy (HE). Breath limonene was higher in patients with No-HCC than with HCC, median (lower/upper quartile) 14.2 (7.2/60.1) versus 3.6 (2.0/13.7) and 1.5 (1.1/2.3) nmol mol^-1 in controls. This may reflect disease severity, as those with No-HCC had significantly higher UKELD (United Kingdom model for End stage Liver Disease) scores. Patients with HE were categorized as having HE symptoms presently, having a history but no current symptoms and having neither history nor current symptoms. Breath limonene in these groups was median (lower/upper quartile) 46.0 (14.0/103), 4.2 (2.6/6.4) and 7.2 (2.0/19.1) nmol mol^-1, respectively. The higher concentration of limonene in those with current symptoms of HE than with a history but no current symptoms cannot be explained by disease severity as their UKELD scores were not significantly different. Longitudinal data from two patients admitted to hospital with HE show a large intra-subject variation in breath limonene, median (range) 18 (10-44) and 42 (32-58) nmol mol^-1.

Volatile Biomarkers in Breath Associated With Liver Cirrhosis - Comparisons of Pre- and Post-liver Transplant Breath Samples

Background

The burden of liver disease in the UK has risen dramatically and there is a need for improved diagnostics.

Aims

To determine which breath volatiles are associated with the cirrhotic liver and hence diagnostically useful.

Methods

A two-stage biomarker discovery procedure was used. Alveolar breath samples of 31 patients with cirrhosis and 30 healthy controls were mass spectrometrically analysed and compared (stage 1). 12 of these patients had their breath analysed after liver transplant (stage 2). Five patients were followed longitudinally as in-patients in the post-transplant period.

Results

Seven volatiles were elevated in the breath of patients versus controls. Of these, five showed statistically significant decrease post-transplant: limonene, methanol, 2-pentanone, 2-butanone and carbon disulfide. On an individual basis limonene has the best diagnostic capability (the area under a receiver operating characteristic curve (AUROC) is 0.91), but this is improved by combining methanol, 2-pentanone and limonene (AUROC curve 0.95). Following transplant, limonene shows wash-out characteristics.

Conclusions

Limonene, methanol and 2-pentanone are breath markers for a cirrhotic liver. This study raises the potential to investigate these volatiles as markers for early-stage liver disease. By monitoring the wash-out of limonene following transplant, graft liver function can be non-invasively assessed.

•

Breath volatiles were compared for cirrhotic patients and controls and pre- and post-liver transplant.

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Three volatiles (limonene, methanol, 2-pentanone) have been found to have excellent diagnostic capabilities.

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Limonene shows washout characteristics following transplant supporting a hypothesis that it accumulates in fat.

There are numerous previous studies investigating breath volatiles in patients with liver disease but with conflicting results. It is impossible to tell which volatiles from previous studies may be false discoveries, and which are actually associated with the disease. We measured breath samples in patients and controls and in patients after transplant. Methanol, 2-pentanone and limonene show differences not only between patients and controls but also in cases pre- and post-transplant and have excellent diagnostic capabilities. We show evidence that limonene accumulates in the body, probably because the cirrhotic liver fails to metabolise dietary limonene.

Impact of intracellular domain flexibility upon properties of activated human 5-HT3 receptors

Background and Purpose

It has been proposed that arginine residues lining the intracellular portals of the homomeric 5-HT₃A receptor cause electrostatic repulsion of cation flow, accounting for a single-channel conductance substantially lower than that of the 5-HT₃AB heteromer. However, comparison of receptor homology models for wild-type pentamers suggests that salt bridges in the intracellular domain of the homomer may impart structural rigidity, and we hypothesized that this rigidity could account for the low conductance.

Experimental Approach

Mutations were introduced into the portal region of the human 5-HT₃A homopentamer, such that putative salt bridges were broken by neutralizing anionic partners. Single-channel and whole cell currents were measured in transfected tsA201 cells and in Xenopus oocytes respectively. Computational simulations of protein flexibility facilitated comparison of wild-type and mutant receptors.

Key Results

Single-channel conductance was increased substantially, often to wild-type heteromeric receptor values, in most 5-HT₃A mutants. Conversely, introduction of arginine residues to the portal region of the heteromer, conjecturally creating salt bridges, decreased conductance. Gating kinetics varied significantly between different mutant receptors. EC₅₀ values for whole-cell responses to 5-HT remained largely unchanged, but Hill coefficients for responses to 5-HT were usually significantly smaller in mutants. Computational simulations suggested increased flexibility throughout the protein structure as a consequence of mutations in the intracellular domain.

Conclusions and Implications

These data support a role for intracellular salt bridges in maintaining the quaternary structure of the 5-HT₃ receptor and suggest a role for the intracellular domain in allosteric modulation of cooperativity and agonist efficacy.

Linked Article

This article is commented on by Vardy and Kenakin, pp. 1614–1616 of volume 171 issue 7. To view this commentary visit http://dx.doi.org/10.1111/bph.12550.

Review article: liver transplantation for the pulmonary disorders of portal hypertension

BACKGROUND

Liver transplantation is potentially a life-saving therapeutic intervention for patients with portopulmonary hypertension and hepatopulmonary syndrome. However, due to limited data, listing criteria for patients with these conditions have not been clearly established. Indeed, this has led some to speculate that transplantation may not be appropriate in cases of moderate-to-severe portopulmonary hypertension and severe hepatopulmonary syndrome.

AIM

To critically discuss the utility of LT for the treatment of hepatopulmonary syndrome and portopulmonary hypertension.

METHODS

A literature search was conducted in 2012 on PubMed, Ovid Embase, Ovid Medline and Scopus using the following search terms: hepatopulmonary syndrome, portopulmonary hypertension, pulmonary arterial hypertension, liver transplantation. Relevant manuscripts were included in the review.

RESULTS

Liver transplantation has established itself as an effective treatment for selected patients with hepatopulmonary syndrome and portopulmonary hypertension. A multidisciplinary team approach incorporating focused strategies (both pre- and post-operatively) aimed at improving oxygenation in patients with hepatopulmonary syndrome has led to a dramatic improvement in patient outcomes. Additionally, careful patient selection and the use of targeted pulmonary vascular therapies are successfully being used to treat portopulmonary hypertension and 'bridge' patients to successful liver transplantation.

CONCLUSIONS

Liver transplantation is an effective therapy for patients with hepatopulmonary syndrome and portopulmonary hypertension. However, rigorous screening and early identification of these conditions allied with aggressive pre-operative optimisation of physiology and diligent post-operative care are imperative to ensuring a good outcome.

Predictive performance of Acute Physiological and Chronic Health Evaluation releases II to IV: a single New Zealand centre experience

There is debate in Australia and New Zealand around the appropriate use of illness severity scoring systems in Australasian intensive care units. The international benchmark is the Acute Physiological and Chronic Health Evaluation (APACHE) system. In order to compare the performance of recent APACHE releases, we audited 2080 sequential patients admitted between 1 January 2006 and 31 March 2008 to the Middlemore Hospital intensive care unit, Auckland, New Zealand. We compared the predictive performance of the proprietary APACHE II, IIIh, IIIj and IV releases, and the performance of a 'localised' version of APACHE II containing re-estimated coefficients derived from a legacy dataset (7703 sequential patients admitted between 1 January 1997 and 31 December 2005). Discrimination assessed by receiver operating characteristic curves was highest with the APACHE III and IV releases, and significantly better than the APACHE II releases. Calibration assessed by the Hosmer-Lemeshow statistic was poor with all releases, although it was best with APACHE IV and 'localised' version of the APACHE II release. Overall accuracy assessed by the Brier Mean Probability score and Shapiro's R statistic was best with APACHE IV. Our study suggests the possibility of improved prediction in moving to APACHE IV from older releases, although broader multicentre study within the Australian and New Zealand critical care community is warranted. Our study also suggests localisation of the APACHE system offers further opportunity to improve prediction, although these improvements may not be major without ground-up development of a new risk prediction model within our local critical care setting.

Donation after cardiac death liver transplant recipients have an increased frequency of acute kidney injury

Donation after cardiac death (DCD) liver transplantation is associated with an increased frequency of hepato-biliary complications. The implications for renal function have not been explored previously. The aims of this single-center study of 88 consecutive DCD liver transplant recipients were (1) to compare renal outcomes with propensity-risk-matched donation after brain death (DBD) patients and (2) in the DCD patients specifically to examine the risk factors for acute kidney injury (AKI; peak creatinine ≥2 times baseline) and chronic kidney disease (CKD; eGFR <60 mL/min/1.73 m(2) ). During the immediate postoperative period DCD liver transplantation was associated with an increased incidence of AKI (DCD, 53.4%; DBD 31.8%, p = 0.004). In DCD patients AKI was a risk factor for CKD (p = 0.035) and mortality (p = 0.017). The cumulative incidence of CKD by 3 years post-transplant was 53.7% and 42.1% for DCD and DBD patients, respectively (p = 0.774). Importantly, increasing peak perioperative aspartate aminotransferase, a surrogate marker of hepatic ischemia reperfusion injury, was the only consistent predictor of renal dysfunction after DCD transplantation (AKI, p < 0.001; CKD, p = 0.032). In conclusion, DCD liver transplantation is associated with an increased frequency of AKI. The findings suggest that hepatic ischemia reperfusion injury may play a critical role in the pathogenesis of post-transplant renal dysfunction.

Patient indicators of a pulmonary exacerbation: preliminary reports from school aged children map onto those of adults

BACKGROUND

Despite the importance of identifying and managing a pulmonary exacerbation, and its use as an outcome measure in interventions, there is no standardised definition in cystic fibrosis. In achieving standardised criteria it is important to identify patient-reported indicators.

METHODS

Interviews were undertaken with 35 school aged children. They reported symptoms experienced during a pulmonary exacerbation in two ways: the first symptoms they become aware of, and how they recognised when they were improving. Interviews were taped, transcribed verbatim and the data analysed thematically.

RESULTS

For many children, the onset of an exacerbation was characterised by 'cold' symptoms, tiredness, and changes in cough. For those with moderate or severe disease, sleep disruption, activity induced breathlessness, changes in mood, sputum volume and lack of appetite were common. When describing improvement children focused initially on activities they were now able to perform accompanied by improvements in tiredness and cough. Those with moderate or severe disease also reported improvements in sleep and mood, breathlessness, sputum volume and colour.

CONCLUSIONS

Child-reported indicators of a pulmonary exacerbation tend to map onto those reported by adults. These results provide the rationale for the development of a single scale for school age children and adults that could be sensitive to progressive stages of CF disease.

Characteristics of Procarbazine as an Inhibitor In-vitro of Rat Semicarbazide-sensitive Amine Oxidase

Procarbazine (N-isopropyl-α-(2−methyl hydrazino)-p-toluamide hydrochloride) inhibited more powerfully the deamination of benzylamine by semicarbazide-sensitive amine oxidase (SSAO) of rat brown adipose tissue than the deamination of 5−hydroxytryptamine and benzylamine by rat liver monoamine oxidase-A or -B activities, respectively. Inhibition of SSAO, but not monoamine oxidase, was time-dependent. Use of metabolic inhibitors, and an enzyme dilution technique, suggested that any conversion of procarbazine to an active species must be as a result of the action of SSAO itself and not of any other enzyme. The non-competitive kinetics and the time-dependence of inhibition were indicative of a suicide interaction between procarbazine and SSAO. The slow reversal of inhibition by dialysis was evidence in favour of the involvement of tight binding, rather than covalent bonding. High concentrations of benzylamine afforded the enzyme significant protection from the action of procarbazine, indicating that the interaction is at or near the active site. If the properties of procarbazine, evident in in-vitro studies, are retained in-vivo, these data suggest that procarbazine might be suitable for the examination of SSAO activities, both in-vivo and ex-vivo.

Effects In-vitro of Procarbazine Metabolites on Some Amine Oxidase Activities in the Rat

The effects were examined of four metabolites of the anticancer agent, procarbazine (N-isopropyl-α-(2−methyl hydrazino)-p-toluamide hydrochloride) on semicarbazide-sensitive amine oxidase (SSAO) and monoamine oxidase-A and -B (MAO-A and -B) activities in rat brown adipose tissue and liver homogenates, respectively. Azoprocarbazine (AZO) and monomethylhydrazine (MMH) inhibited selectively the deamination of benzylamine by SSAO, when compared with their effects on MAO activities. The IC50 values against SSAO, of 32·7 Nm (AZO) and 7·0 Nm (MMH), were more than three orders of magnitude lower than those exhibited against MAO. Neither isomer of azoxyprocarbazine was an effective inhibitor of rat amine oxidase activities. The inhibition of SSAO by AZO was reversed very slowly by dialysis, in contrast to results seen for MMH. The non-competitive kinetics of MMH and the ability of B24, a rapidly reversible SSAO inhibitor, to protect SSAO against inhibition by MMH are consistent with the view that this compound binds to the enzyme cofactor at, or near, the active site.

What defines a pulmonary exacerbation? The perceptions of adults with cystic fibrosis

BACKGROUND

There is no standardised definition of a pulmonary exacerbation in cystic fibrosis (CF). In attempting to achieve standardised criteria it is important to identify patient-reported indicators.

METHODS

Interviews were undertaken with 47 adults with CF. Participants were asked to report symptoms experienced during a pulmonary exacerbation in two ways: the first symptoms they become aware of, and how they subsequently recognised when they were improving.

RESULTS

A range of systemic and respiratory symptoms were reported. Their relative importance varied by severity of disease. The severity and subsequent improvement of an exacerbation was often described as limitations on their activities.

CONCLUSION

These preliminary data suggest that patient-reported indicators of a pulmonary exacerbation may not be the same for all adults with CF. Whether different indicators are associated with specific demographic or clinical variables remains to be evaluated.

Refining the 22q11.2 deletion breakpoints in DiGeorge syndrome by aCGH

Hemizygous deletions of the chromosome 22q11.2 region result in the 22q11.2 deletion syndrome also referred to as DiGeorge, Velocardiofacial or Shprintzen syndromes. The phenotype is variable but commonly includes conotruncal cardiac defects, palatal abnormalities, learning and behavioral problems, immune deficiency, and facial anomalies. Four distinct highly homologous blocks of low copy number repeat sequences (LCRs) flank the deletion region. Mispairing of LCRs during meiosis with unequal meiotic exchange is assumed to cause the recurrent and consistent deletions. The proximal LCR is reportedly located at 22q11.2 from 17.037 to 17.083 Mb while the distal LCR is located from 19.835 to 19.880 Mb. Although the chromosome breakpoints are thought to localize to the LCRs, the positions of the breakpoints have been investigated in only a few individuals. Therefore, we used high resolution oligonucleotide-based 244K microarray comparative genomic hybridization (aCGH) to resolve the breakpoints in a cohort of 20 subjects with known 22q11.2 deletions. We also investigated copy number variation (CNV) in the rest of the genome. The 22q11.2 breaks occurred on either side of the LCR in our subjects, although more commonly on the distal side of the reported proximal LCR. The proximal breakpoints in our subjects spanned the region from 17.036 to 17.398 Mb. This region includes the genes DGCR6 (DiGeorge syndrome critical region protein 6) and PRODH (proline dehydrogenase 1), along with three open reading frames that may encode proteins of unknown function. The distal breakpoints spanned the region from 19.788 to 20.122 Mb. This region includes the genes GGT2 (gamma-glutamyltransferase-like protein 2), HIC2 (hypermethylated in cancer 2), and multiple transcripts of unknown function. The genes in these two breakpoint regions are variably hemizygous depending on the location of the breakpoints. Our 20 subjects had 254 CNVs throughout the genome, 94 duplications and 160 deletions, ranging in size from 1 kb to 2.4 Mb. The presence or absence of genes at the breakpoints depending on the size of the deletion plus variation in the rest of the genome due to CNVs likely contribute to the variable phenotype associated with the 22q11.2 deletion or DiGeorge syndrome.

Impact of changing water levels and weather on Oncomelania hupensis hupensis populations, the snail host of Schistosoma japonicum, downstream of the Three Gorges Dam

Increasing evidence indicates that dams impact riverine ecosystems and human diseases. Poyang Lake, one of the largest schistosomiasis endemic environments in China, will change due to the construction of the Yangtze River Three Gorges Dam. We assess changes in Oncomelania hupensis hupensis, the snail host for Schistosoma japonicum, in response to changing water levels and weather from 1998 to 2002. In the 5 years following the major flooding of Poyang Lake in 1998, seasonal water levels have gradually decreased, concomitant with decreases in mean and variance of fall snail densities. Nonlinear relationships suggest that the highest spring density is associated with current, 2-, and 3-month prior temperatures of 18 degrees, 9.1 degrees, and 5.8 degrees C, while the highest fall density is associated with 2- and 3-month prior water levels of 17 and 18 m, respectively. This suggests that lower, more stable water levels downstream of the dam may result in a reduction in mean fall densities and their variance. However, additional data are needed to determine whether snail populations that are typically destroyed by seasonal floods may live longer in more stable environments created by the dam.

Spatial distribution of traffic induced noise exposures in a US city: an analytic tool for assessing the health impacts of urban planning decisions

BACKGROUND

Vehicle traffic is the major source of noise in urban environments, which in turn has multiple impacts on health. In this paper we investigate the spatial distribution of community noise exposures and annoyance. Traffic data from the City of San Francisco were used to model noise exposure by neighborhood and road type. Remote sensing data were used in the model to estimate neighborhood-specific percentages of cars, trucks, and buses on arterial versus non-arterial streets. The model was validated on 235 streets. Finally, an exposure-response relationship was used to predict the prevalence of high annoyance for different neighborhoods.

RESULTS

Urban noise was found to increase 6.7 dB (p < 0.001) with 10-fold increased street traffic, with important contributors to noise being bus and heavy truck traffic. Living along arterial streets also increased risk of annoyance by 40%. The relative risk of annoyance in one of the City's fastest growing neighborhoods, the South of Market Area, was found to be 2.1 times that of lowest noise neighborhood. However, higher densities of exposed individuals were found in Chinatown and Downtown/Civic Center. Overall, we estimated that 17% of the city's population was at risk of high annoyance from traffic noise.

CONCLUSION

The risk of annoyance from urban noise is large, and varies considerably between neighborhoods. Such risk should be considered in urban areas undergoing rapid growth. We present a relatively simple GIS-based noise model that may be used for routinely evaluating the health impacts of environmental noise.