The importance of patient characteristics, operators, and image quality for accurate diagnoses of heart failure by general practitioners using hand-held ultrasound

Background

Echocardiography is a cornerstone in diagnosing heart failure (HF). Hand-held ultrasound devices (HUDs) are established diagnostic tools. After a period of training, inexperienced users can utilize HUDs in HF diagnostics. Developments have allowed for decision-support software such as automatic analyses of ejection fraction (autoEF), mitral annular plane systolic excursion (autoMAPSE) and telemedicine. It is not well established how patient characteristics, operator qualifications and image quality influence the clinical usefulness of HUDs. Furthermore, it is not known whether associations of patient-, operator- and image quality characteristics with diagnostic accuracy is consistent across different decision-support software.

Purpose

To evaluate associations of patient-, operator- and image quality characteristics with the accuracy of HF diagnostics by general practitioners (GPs) using HUDs with and without decision-support software.

Method

After a period of training, five GPs examined outpatients with suspected HF. They examined the patients clinically and subsequently by adding HUD examinations, autoEF and autoMAPSE. Recorded images were interpreted by external cardiologists using a telemedical software program, giving immediate feedback to the GPs. After each step the GPs considered whether the patients had HF. Diagnostic accuracy was evaluated by comparing to reference echocardiograms by cardiologists. Image quality was evaluated by external cardiologists scoring each of the categories; LV view, LV alignment, apical misposition, mitral annular assessment and visible segments. The associations of possible predictors with the diagnostic accuracy were tested by univariate regression.

Results

Of 166 patients, 28 were diagnosed with HF after reference examinations. The GPs correctly diagnosed 72% of the patients after HUD examinations, 55% after autoMAPSE, 57% after autoEF and 76% after telemedical support. Atrial fibrillation (AF) was present in 40 patients, 27 had chronic obstructive pulmonary disease and 121 had body mass index >25 kg/m2. Ongoing AF was significantly associated with reduced accuracy using HUD examination alone and in combination with autoEF (p<0.05). No other patient characteristics were associated with GPs' diagnostic accuracy. There were significant differences between different operators when autoMAPSE was used (p<0.05). Image quality indices were not significantly associated with diagnostic accuracy (p≥0.2).

Conclusion

Atrial fibrillation and operator characteristics were associated with reduced diagnostic accuracy when basing diagnosis on automatic decision support software. No other association of neither patient-, operator- nor image quality characteristics with the accuracy of GP diagnostics was found. Thus, it is important that the clinical society is aware of the limited to modest accuracy of HF diagnostics by inexperienced users of hand-held ultrasound including novel decision-support software.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Research council of NorwayNorwegian University of Science and Technology

Differences in obstetrical care and outcomes associated with the proportion of the obstetrician's shift completed

BACKGROUND

Understanding and improving obstetrical quality and safety is an important goal of professional societies, and many interventions such as checklists, safety bundles, educational interventions, or other culture changes have been implemented to improve the quality of care provided to obstetrical patients. Although many factors contribute to delivery decisions, a reduced workload has addressed how provider issues such as fatigue or behaviors surrounding impending shift changes may influence the delivery mode and outcomes.

OBJECTIVE

The objective was to assess whether intrapartum obstetrical interventions and adverse outcomes differ based on the temporal proximity of the delivery to the attending's shift change.

STUDY DESIGN

This was a secondary analysis from a multicenter obstetrical cohort in which all patients with cephalic, singleton gestations who attempted vaginal birth were eligible for inclusion. The primary exposure used to quantify the relationship between the proximity of the provider to their shift change and a delivery intervention was the ratio of time from the most recent attending shift change to vaginal delivery or decision for cesarean delivery to the total length of the shift. Ratios were used to represent the proportion of time completed in the shift by normalizing for varying shift lengths. A sensitivity analysis restricted to patients who were delivered by physicians working 12-hour shifts was performed. Outcomes chosen included cesarean delivery, episiotomy, third- or fourth-degree perineal laceration, 5-minute Apgar score of <4, and neonatal intensive care unit admission. Chi-squared tests were used to evaluate outcomes based on the proportion of the attending's shift completed. Adjusted and unadjusted logistic models fitting a cubic spline (when indicated) were used to determine whether the frequency of outcomes throughout the shift occurred in a statistically significant, nonlinear pattern RESULTS: Of the 82,851 patients eligible for inclusion, 47,262 (57%) had ratio data available and constituted the analyzable sample. Deliveries were evenly distributed throughout shifts, with 50.6% taking place in the first half of shifts. There were no statistically significant differences in the frequency of cesarean delivery, episiotomy, third- or fourth-degree perineal lacerations, or 5-minute Apgar scores of <4 based on the proportion of the shift completed. The findings were unchanged when evaluated with a cubic spline in unadjusted and adjusted logistic models. Sensitivity analyses performed on the 22.2% of patients who were delivered by a physician completing a 12-hour shift showed similar findings. There was a small increase in the frequency of neonatal intensive care unit admissions with a greater proportion of the shift completed (adjusted P=.009), but the findings did not persist in the sensitivity analysis.

CONCLUSION

Clinically significant differences in obstetrical interventions and outcomes do not seem to exist based on the temporal proximity to the attending physician's shift change. Future work should attempt to directly study unit culture and provider fatigue to further investigate opportunities to improve obstetrical quality of care, and additional studies are needed to corroborate these findings in community settings.

Ethnic differences in incidence and mortality of stroke in Denmark

Background

Stroke is a leading cause of disability and mortality worldwide. However, studies on incidence and mortality of stroke hereof among ethnic minorities compared with local born are still limited.

Methods

We conducted a Danish nationwide register-based cohort study between 2004 and 2018. All cases of first ever stroke aged 18-95 years were included. Country of birth was used to construct ethnic groups. Age standardized incidence rate ratio (IRR) of stroke stratified by country of birth and sex were estimated with the Danish born as a reference group. Ethnic minorities were grouped as Western and Non-western for mortality hazard ratio (HR) estimates.

Results

In overall, ethnic minorities had a higher risk of stroke compared with Danish born. Particularly, the IRR of all stroke was estimated to be 8.3 times higher among Polish men compared to Danish born men (IRR, 8.32; 95% CI, 6.89-10.05). Compared with Danish born women, Pakistan women had the highest risk of all stroke (IRR, 2.89; 95% CI, 2.46-3.39). By contrast, Swedish women had reduced risk of hemorrhagic stroke (IRR, 0.40; 95% CI, 0.18-0.89) and Norwegian women had reduced risk of ischemic stroke (IRR, 0.87; 95% CI, 0.72-1.06). Compared with Danish born men, all-cause 1-year mortality hazard for Non-western men was (HR, 1.61; 95% CI, 1.13-2.29) while for Western men was (HR, 1.07; 95% CI, 0.90-1.29) among ischemic stroke patients. Among hemorrhagic stroke patients, 1-year mortality hazard for Non-western men was (HR, 0.75; 95% CI, 0.39-1.47) whereas Western men had (HR, 1.48; 95% CI, 1.04-2.10). Among women, we observed reduced all cause 1-year mortality hazard in Non-western (HR, 0.32; 95% CI, 0.13-0.80) for hemorrhagic stroke whereas no difference in mortality hazard was observed for ischemic stroke.

Conclusions

Incidence and post stroke mortality appear to vary among ethnic minorities in comparison to Danish born. It may depend on the type of stroke and sex.

Key messages

The study contributes knowledge in migration and health. With good quality registers, we are in unique position to establish findings in Denmark, which has a growing migrant population.

Post-stroke depression: Diagnosis and incidence

Diagnosis of post-stroke depression (PSD) is extremely difficult due to concomitant focal cognitive disturbances or generalized intellectual impairment, and, in some cases, dissociation of mood and affective behavior. The diagnosis has been standardized on the basis of psychiatric criteria in the Diagnostic and Statistical Manual (DSM)-III, an approach that has been criticized for taking into account non-specific stroke-related somatic symptoms. Yet evaluation of the PSD diagnosis by comparing the severity of depressive symptoms in stroke to an age-matched population sample and by conducting a controlled antidepressant treatment study in unselected PSD patients has failed to disclose any evidence that non-specific symptoms influence the diagnosis of PSD. The prognosis, however, of early vs late diagnosed PSD and the response to treatment of early vs late diagnosed PSD differ, indicating that PSD diagnosed according to DSM-III criteria covers a heterogeneous group of etiologically different conditions.

15O-water PET for evaluation of cardiopulmonary perfusion in complex cyanotic heart disease

Background

Dynamic ¹⁵O-water PET may provide information about cardiopulmonary circulation complementary to MRI and CT in complex cyanotic heart disease.

Case presentation

We present a case in which a ¹⁵O-water PET scan was used for the first time to map the complex circulation in a univentricular heart patient with dual pulmonary blood supply. The pulmonary blood supply consisted of partially oxygenated blood led from the univentricle to the lungs by the pulmonary artery, plus of venous blood from the upper body lead by a bidirectional Glenn anastomosis to the right pulmonary artery. Despite the bidirectional Glenn anastomosis, the patient developed increasing cyanosis and was considered for heart transplantation. Pulmonary perfusion measurements using MRI were inconclusive due to metal artifacts, and the patient was referred for a ¹⁵O-water PET scan. The scan showed significant venovenous collaterals bypassing the lungs. Only the left upper lung lobe was properly perfused. The mean transit time from the superior vena cava to the left ventricle was approximately four times longer than would be expected from a healthy person.

Conclusion

The case illustrates that ¹⁵O-water PET can complement CT and MRI for quantitative characterization of cardiopulmonary circulation in complex cyanotic heart disease.

Neonatal outcomes of elective early-term births after demonstrated fetal lung maturity

BACKGROUND

Studies of early-term birth after demonstrated fetal lung maturity show that respiratory and other outcomes are worse with early-term birth (37⁰-38⁶ weeks) even after demonstrated fetal lung maturity when compared with full-term birth (39⁰-40⁶ weeks). However, these studies included medically indicated births and are therefore potentially limited by confounding by the indication for delivery. Thus, the increase in adverse outcomes might be due to the indication for early-term birth rather than the early-term birth itself.

OBJECTIVE

We examined the prevalence and risks of adverse neonatal outcomes associated with early-term birth after confirmed fetal lung maturity as compared with full-term birth in the absence of indications for early delivery.

STUDY DESIGN

This is a secondary analysis of an observational study of births to 115,502 women in 25 hospitals in the United States from 2008 through 2011. Singleton nonanomalous births at 37-40 weeks with no identifiable indication for delivery were included; early-term births after positive fetal lung maturity testing were compared with full-term births. The primary outcome was a composite of death, ventilator for ≥2 days, continuous positive airway pressure, proven sepsis, pneumonia or meningitis, treated hypoglycemia, hyperbilirubinemia (phototherapy), and 5-minute Apgar <7. Logistic regression and propensity score matching (both 1:1 and 1:2) were used.

RESULTS

In all, 48,137 births met inclusion criteria; the prevalence of fetal lung maturity testing in the absence of medical or obstetric indications for early delivery was 0.52% (n = 249). There were 180 (0.37%) early-term births after confirmed pulmonary maturity and 47,957 full-term births. Women in the former group were more likely to be non-Hispanic white, smoke, have received antenatal steroids, have induction, and have a cesarean. Risks of the composite (16.1% vs 5.4%; adjusted odds ratio, 3.2; 95% confidence interval, 2.1-4.8 from logistic regression) were more frequent with elective early-term birth. Propensity scores matching confirmed the increased primary composite in elective early-term births: adjusted odds ratios, 4.3 (95% confidence interval, 1.8-10.5) for 1:1 and 3.5 (95% confidence interval, 1.8-6.5) for 1:2 matching. Among components of the primary outcome, CPAP use and hyperbilirubinemia requiring phototherapy were significantly increased. Transient tachypnea of the newborn, neonatal intensive care unit admission, and prolonged neonatal intensive care unit stay (>2 days) were also increased with early-term birth.

CONCLUSION

Even with confirmed pulmonary maturity, early-term birth in the absence of medical or obstetric indications is associated with worse neonatal respiratory and hepatic outcomes compared with full-term birth, suggesting relative immaturity of these organ systems in early-term births.

Prescription and predictors of post-stroke antidepressant treatment: A population-based study

OBJECTIVES

Post-stroke depression and pathological crying are common and potentially serious complications after stroke and should be diagnosed and treated accordingly. Diagnosis and treatment probably rely on clinical experience and may pose certain challenges. We aimed to examine prescription and predictors of antidepressant treatment after ischemic stroke in a clinical setting.

MATERIALS AND METHODS

In this registry-based follow-up study, consecutive ischemic stroke patients were identified from the Danish Stroke Registry, holding information on antidepressant treatment during admission in Aarhus County from 2003 to 2010. Information on prescription after discharge was obtained from the Danish Prescription Database. Treatment initiation was analyzed using the cumulative incidence method including death as a competing risk. Multiple logistic regression was used to identify potential predictors of treatment.

RESULTS

Among 5070 consecutive first-ever ischemic stroke patients without prior antidepressant treatment, the cumulative incidence of antidepressant treatment and prescription over 6 months was 35.2% (95% CI: 33.8-36.6). Overall 16.5% (95% CI: 15.5-17.6) started treatment within 14 days corresponding to 48.1% (95% CI: 45.8-50.5) of all treated patients, and the most widely prescribed group of antidepressants was selective serotonin reuptake inhibitors (86%). Increasing stroke severity was associated with higher odds of initiating treatment.

CONCLUSION

Antidepressant treatment in this real-life clinical setting was common and initiated early, in almost half the treated patients within 14 days. Our results suggest that special focus should be given to the severe strokes as they may have a greater risk of requiring treatment.

Ischemic stroke subtype is associated with outcome in thrombolyzed patients

OBJECTIVES

The impact of ischemic stroke subtype on clinical outcome in patients treated with intravenous tissue-type plasminogen activator (IV-tPA) is sparsely examined. We studied the association between stroke subtype and clinical outcome in magnetic resonance imaging (MRI)-evaluated patients treated with IV-tPA.

MATERIAL AND METHODS

We conducted a single-center retrospective analysis of MRI-selected stroke patients treated with IV-tPA between 2004 and 2010. The Trial of ORG 10172 in Acute Stroke Treatment criteria were used to establish the stroke subtype by 3 months. The outcomes of interest were a 3-month modified Rankin Scale score of 0-1 (favorable outcome), and early neurological improvement defined as complete remission of neurological deficit or improvement of ≥4 on the National Institute of Health Stroke Scale at 24 h. The outcomes among stroke subtypes were compared with multivariable logistic regression.

RESULTS

Among 557 patients, 202 (36%) had large vessel disease (LVD), 153 (27%) cardioembolic stroke (CE), 109 (20%) small vessel disease, and 93 (17%) were of other or undetermined etiology. Early neurological improvement was present in 313 (56.4%) patients, and 361 (64.8%) patients achieved a favorable outcome. Early neurological improvement and favorable outcome were more likely in CE patients compared with LVD patients (odds ratio (OR), 2.1 (95% confidence interval, 1.4-3.3), and 2.0 (95% confidence interval, 1.2-3.3), respectively).

CONCLUSIONS

Cardioembolic stroke patients were more likely to achieve early neurological improvement and favorable outcome compared with LVD stroke following MRI-based IV-tPA treatment. This finding may reflect a difference in the effect of IV-tPA among stroke subtypes.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

Post-anaesthetic emergence delirium in adults: incidence, predictors and consequences

BACKGROUND

Emergence delirium (ED) after general anaesthesia (GA) is a well-known phenomenon, yet the risk factors are still unclear. The aims of this study were to determine the incidence and independent predictors of ED and secondly to determine to which degree ED has any relevant, clinical consequences to medical staff as well as to patients.

METHOD

This prospective, observational cohort study assessed adult patients emerging from GA in the operating room, using the Richmond Agitation-Sedation Scale (RASS). Signs of ED, defined as RASS≥1 along with possible clinical consequences were noted. Patients with ED were re-evaluated in the post-anaesthesia care unit (PACU) and concomitant patient and anaesthesia related factors were noted.

RESULTS

Among the 1970 patients enrolled, 73 (3.7%) showed signs of ED when emerging from anaesthesia. When reassessed in PACU, the number had declined to 25 patients (1.3%). Male sex, endotracheal tube (ETT) and volatile anaesthetics were found to be significantly related to developing ED after anaesthesia. In 20 cases, additional staff had to be called for and in one case, an i.v. access was accidentally removed. Neither patients nor staff were hurt.

CONCLUSION

Male sex, volatile anaesthetics and ETT were factors significantly related to ED. Whether gender, choice of respiratory devices and anaesthetics are true predictors or derived factors of surgery procedures, duration of surgery and the patients' physical condition need further investigation. The most notable clinical consequence of ED was the need of additional staff in order to restrain the agitated patient.

Preterm neonatal morbidity and mortality by gestational age: a contemporary cohort

BACKGROUND

Although preterm birth <37 weeks' gestation is the leading cause of neonatal morbidity and mortality in the United States, the majority of data regarding preterm neonatal outcomes come from older studies, and many reports have been limited to only very preterm neonates. Delineation of neonatal outcomes by delivery gestational age is needed to further clarify the continuum of mortality and morbidity frequencies among preterm neonates.

OBJECTIVE

We sought to describe the contemporary frequencies of neonatal death, neonatal morbidities, and neonatal length of stay across the spectrum of preterm gestational ages.

STUDY DESIGN

This was a secondary analysis of an obstetric cohort of 115,502 women and their neonates who were born in 25 hospitals nationwide, 2008 through 2011. All liveborn nonanomalous singleton preterm (23.0-36.9 weeks of gestation) neonates were included in this analysis. The frequency of neonatal death, major neonatal morbidity (intraventricular hemorrhage grade III/IV, seizures, hypoxic-ischemic encephalopathy, necrotizing enterocolitis stage II/III, bronchopulmonary dysplasia, persistent pulmonary hypertension), and minor neonatal morbidity (hypotension requiring treatment, intraventricular hemorrhage grade I/II, necrotizing enterocolitis stage I, respiratory distress syndrome, hyperbilirubinemia requiring treatment) were calculated by delivery gestational age; each neonate was classified once by the worst outcome for which criteria was met.

RESULTS

In all, 8334 deliveries met inclusion criteria. There were 119 (1.4%) neonatal deaths. In all, 657 (7.9%) neonates had major morbidity, 3136 (37.6%) had minor morbidity, and 4422 (53.1%) survived without any of the studied morbidities. Deaths declined rapidly with each advancing week of gestation. This decline in death was accompanied by an increase in major neonatal morbidity, which peaked at 54.8% at 25 weeks of gestation. As frequencies of death and major neonatal morbidity fell, minor neonatal morbidity increased, peaking at 81.7% at 31 weeks of gestation. The frequency of all morbidities fell >32 weeks. After 25 weeks, neonatal length of hospital stay decreased significantly with each additional completed week of pregnancy; among babies delivered from 26-32 weeks of gestation, each additional week in utero reduced the subsequent length of neonatal hospitalization by a minimum of 8 days. The median postmenstrual age at discharge nadired around 36 weeks' postmenstrual age for babies born at 31-35 weeks of gestation.

CONCLUSION

Our data show that there is a continuum of outcomes, with each additional week of gestation conferring survival benefit while reducing the length of initial hospitalization. These contemporary data can be useful for patient counseling regarding preterm outcomes.

Biodegradation of dispersed Macondo crude oil by indigenous Gulf of Mexico microbial communities

Because of the extreme conditions of the Deepwater Horizon (DWH) release (turbulent flow at 1500m depth and 5°C water temperature) and the sub-surface application of dispersant, small but neutrally buoyant oil droplets <70μm were formed, remained in the water column and were subjected to in-situ biodegradation processes. In order to investigate the biodegradation of Macondo oil components during the release, we designed and performed an experiment to evaluate the interactions of the indigenous microbial communities present in the deep waters of the Gulf of Mexico (GOM) with oil droplets of two representative sizes (10μm and 30μm median volume diameter) created with Macondo source oil in the presence of Corexit 9500 using natural seawater collected at the depth of 1100-1300m in the vicinity of the DWH wellhead. The evolution of the oil was followed in the dark and at 5°C for 64days by collecting sacrificial water samples at fixed intervals and analyzing them for a wide range of chemical and biological parameters including volatile components, saturated and aromatic hydrocarbons, dispersant markers, dissolved oxygen, nutrients, microbial cell counts and microbial population dynamics. A one phase exponential decay from a plateau model was used to calculate degradation rates and lag times for more than 150 individual oil components. Calculations were normalized to a conserved petroleum biomarker (30αβ-hopane). Half-lives ranged from about 3days for easily degradable compounds to about 60days for higher molecular weight aromatics. Rapid degradation was observed for BTEX, 2-3 ring PAHs, and n-alkanes below n-C23. The results in this experimental study showed good agreement with the n-alkane (n-C13 to n-C26) half-lives (0.6-9.5days) previously reported for the Deepwater Horizon plume samples and other laboratory studies with chemically dispersed Macondo oil conducted at low temperatures (<8°C). The responses of the microbial populations also were consistent with what was reported during the actual oil release, e.g. Colwellia, Cycloclasticus and Oceanospirillales (including the specific DWH Oceanospirillales) were present and increased in numbers indicating that they were degrading components of the oil. The consistency of the field and laboratory data indicate that these results could be used, in combination with other field and model data to characterize the dissipation of Macondo oil in the deepwater environment as part of the risk assessment estimations.

Nonmedically indicated induction vs expectant treatment in term nulliparous women

OBJECTIVE

The purpose of this study was to compare maternal and neonatal outcomes in nulliparous women with nonmedically indicated inductions at term vs those expectantly treated.

STUDY DESIGN

Data were obtained from maternal and neonatal charts for all deliveries on randomly selected days across 25 US hospitals over a 3-year period. A low-risk subset of nulliparous women with vertex nonanomalous singleton gestations who delivered 38 0/7 to 41 6/7 weeks were selected. Maternal and neonatal outcomes for nonmedically indicated induction within each week were compared with women who did not undergo nonmedically indicated induction during that week. Multivariable analysis was used to adjust for hospital, maternal age, race/ethnicity, body mass index, cigarette use, and insurance status.

RESULTS

We found 31,169 women who met our criteria. Neonatal complications were either less frequent with nonmedically indicated induction or no different between groups. Nonmedically indicated induction was associated with less frequent peripartum infections (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.16-0.98) at 38 weeks of gestation and less frequent third- and fourth-degree lacerations (OR, 0.60; 95% CI, 0.42-0.86) and less frequent peripartum infections (OR, 0.66; 95% CI, 0.49-0.90) at 39 weeks of gestation. Nonmedically indicated induction was associated with a longer admission-to-delivery time by approximately 3-4 hours and increased odds of cesarean delivery at 38 (OR, 1.50; 95% CI, 1.08-2.08) and 40 weeks (OR, 1.30; 95% CI, 1.15-1.46) of gestation.

CONCLUSION

At 39 weeks of gestation, nonmedically indicated induction is associated with lower maternal and neonatal morbidity than women who are expectantly treated.

Post-stroke pathological crying: frequency and correlation to depression

While pathological crying has classically been described as a disturbance of the motor concomitants of emotional affect that is unrelated to mood, recent studies indicate that there may in fact be a correlation. We therefore undertook a study of post-stroke pathological crying in relation to mood score/depression and lesion site in an unselected stroke population the first year following stroke. The study population comprised 211 patients with first ever stroke (median age 69 years, range 25-80). The patients were included in the study within 7 days of the onset of stroke, and follow-up examinations were made at 1 month, 6 months and 1 year. Computerized tomography brain scans were obtained on Days 5-10. The frequency of pathological crying was 14% at 1 month, 10% at 6 months and 11% at 1 year. The overall 1 year incidence was 19%. Pathological crying correlated significantly to mood score and post-stroke depression (p < 0.005), as well as to lesion size (p < 0.05), Barthel Index (p < 0.05), Motricity Index (p < 0.005) and intellectual impairment (p < 0.05), but not to lesion location, sex, age, history of stroke or depression, predisposing disease or social distress before the stroke incident Post-stroke pathological crying was common and persistent in 11% of patients at 1 year and correlated strongly to mood score and post-stroke depression. The indication for treatment of pathological crying is therefore further strengthened.

Exome sequencing-driven discovery of coding polymorphisms associated with common metabolic phenotypes

AIMS/HYPOTHESIS

Human complex metabolic traits are in part regulated by genetic determinants. Here we applied exome sequencing to identify novel associations of coding polymorphisms at minor allele frequencies (MAFs) >1% with common metabolic phenotypes.

METHODS

The study comprised three stages. We performed medium-depth (8×) whole exome sequencing in 1,000 cases with type 2 diabetes, BMI >27.5 kg/m(2) and hypertension and in 1,000 controls (stage 1). We selected 16,192 polymorphisms nominally associated (p < 0.05) with case-control status, from four selected annotation categories or from loci reported to associate with metabolic traits. These variants were genotyped in 15,989 Danes to search for association with 12 metabolic phenotypes (stage 2). In stage 3, polymorphisms showing potential associations were genotyped in a further 63,896 Europeans.

RESULTS

Exome sequencing identified 70,182 polymorphisms with MAF >1%. In stage 2 we identified 51 potential associations with one or more of eight metabolic phenotypes covered by 45 unique polymorphisms. In meta-analyses of stage 2 and stage 3 results, we demonstrated robust associations for coding polymorphisms in CD300LG (fasting HDL-cholesterol: MAF 3.5%, p = 8.5 × 10(-14)), COBLL1 (type 2 diabetes: MAF 12.5%, OR 0.88, p = 1.2 × 10(-11)) and MACF1 (type 2 diabetes: MAF 23.4%, OR 1.10, p = 8.2 × 10(-10)).

CONCLUSIONS/INTERPRETATION

We applied exome sequencing as a basis for finding genetic determinants of metabolic traits and show the existence of low-frequency and common coding polymorphisms with impact on common metabolic traits. Based on our study, coding polymorphisms with MAF above 1% do not seem to have particularly high effect sizes on the measured metabolic traits.

Biogeography of bacterioplankton in the tropical seawaters of Singapore

Knowledge about the biogeography of marine bacterioplankton on the global scale in general and in Southeast Asia in particular has been scarce. This study investigated the biogeography of bacterioplankton community in Singapore seawaters. Twelve stations around Singapore island were sampled on different schedules over 1 year. Using PCR-DNA fingerprinting, DNA cloning and sequencing, and microarray hybridization of the 16S rRNA genes, we observed clear spatial variations of bacterioplankton diversity within the small area of the Singapore seas. Water samples collected from the Singapore Strait (south) throughout the year were dominated by DNA sequences affiliated with Cyanobacteria and Alphaproteobacteria that were believed to be associated with the influx of water from the open seas in Southeast Asia. On the contrary, water in the relatively polluted Johor Strait (north) were dominated by Betaproteobacteria, Gammaproteobacteria, and Bacteroidetes and that were presumably associated with river discharge and the relatively eutrophic conditions of the waterway. Bacterioplankton diversity was temporally stable, except for the episodic surge of Pseudoalteromonas, associated with algal blooms. Overall, these results provide valuable insights into the diversity of bacterioplankton communities in Singapore seas and the possible influences of hydrological conditions and anthropogenic activities on the dynamics of the communities.

Complexity and variability of gut commensal microbiota in polyphagous lepidopteran larvae

Background

The gut of most insects harbours nonpathogenic microorganisms. Recent work suggests that gut microbiota not only provide nutrients, but also involve in the development and maintenance of the host immune system. However, the complexity, dynamics and types of interactions between the insect hosts and their gut microbiota are far from being well understood.

Methods/Principal Findings

To determine the composition of the gut microbiota of two lepidopteran pests, Spodoptera littoralis and Helicoverpa armigera, we applied cultivation-independent techniques based on 16S rRNA gene sequencing and microarray. The two insect species were very similar regarding high abundant bacterial families. Different bacteria colonize different niches within the gut. A core community, consisting of Enterococci, Lactobacilli, Clostridia, etc. was revealed in the insect larvae. These bacteria are constantly present in the digestion tract at relatively high frequency despite that developmental stage and diet had a great impact on shaping the bacterial communities. Some low-abundant species might become dominant upon loading external disturbances; the core community, however, did not change significantly. Clearly the insect gut selects for particular bacterial phylotypes.

Conclusions

Because of their importance as agricultural pests, phytophagous Lepidopterans are widely used as experimental models in ecological and physiological studies. Our results demonstrated that a core microbial community exists in the insect gut, which may contribute to the host physiology. Host physiology and food, nevertheless, significantly influence some fringe bacterial species in the gut. The gut microbiota might also serve as a reservoir of microorganisms for ever-changing environments. Understanding these interactions might pave the way for developing novel pest control strategies.

Post-stroke fatigue and return to work: a 2-year follow-up

BACKGROUND

Post-stroke fatigue may affect the ability to return to work but quantitative studies are lacking.

METHOD

We included 83 first-ever stroke patients <60 years and employed either full-time (n = 77) or part-time (n = 6) at baseline. The patients were recruited from stroke units at Aarhus University Hospital between 2003 and 2005 and were followed for 2 years. Fatigue was assessed by the Multidimensional Fatigue Inventory. Pathological fatigue was defined as a score ≥12 on the General Fatigue dimension. Return to paid work was defined as working at least 10 h per week. Data were analyzed using multivariable logistic regression.

RESULTS

A total of 58% of patients had returned to paid work after 2 years. The adjusted Odds Ratio (OR) for returning to paid work was 0.39 (95% confidence interval (CI) 0.16-1.08) for patients with a General Fatigue score ≥12 at baseline. Persisting pathological fatigue after 2 years of follow-up was associated with a lower chance of returning to paid work [adjusted OR 0.29 (95% CI 0.11-0.74)]. Higher scores of General Fatigue at follow-up also correlated negatively with the chance of returning to paid work when analyzing fatigue on a continuous scale (adjusted OR 0.87, 95% CI 0.80-0.94 for each point increase in General Fatigue).

CONCLUSIONS

Post-stroke fatigue appears to be an independent determinant of not being able to resume paid work following stroke.

Remote Ischemic Perconditioning in Thrombolysed Stroke Patients: Randomized Study of Activating Endogenous Neuroprotection – Design and MRI Measurements

Background

Intravenous administration of alteplase is the only approved treatment for acute ischemic stroke. Despite the effectiveness of this treatment, 50% of patients suffer chronic neurological disability, which may in part be caused by ischemia-reperfusion injury. Remote ischemic perconditioning, performed as a transient ischemic stimulus by blood-pressure cuff inflation to an extremity, has proven effective in attenuating ischemia-reperfusion injury in animal models of stroke. Remote ischemic perconditioning increases myocardial salvage in patients undergoing acute revascularization for acute myocardial infarction. To clarify whether a similar benefit can be obtained in patients undergoing thrombolysis for acute stroke, we included patients from June 2009 to January 2011.

Aim and design

The aims of the study are: to estimate the effect of remote ischemic perconditioning as adjunctive therapy to intravenous alteplase of acute ischemic stroke within the 4½-h time window and to investigate the feasibility of remote ischemic perconditioning performed during transport to hospital in patients displaying symptoms of acute stroke. Patients are randomized to remote ischemic perconditioning in a single-blinded fashion during transportation to hospital. Only patients with magnetic resonance imaging-proven ischemic stroke, who subsequently are treated with intravenous alteplase, and in selected cases additional endovascular treatment, are finally included in the study.

Study outcomes

Primary end-point is penumbral salvage. Penumbra is defined as hypoperfused yet viable tissue identified as the mismatch between perfusion-weighted imaging and diffusion-weighted imaging lesion on magnetic resonance imaging scans. Primary outcome is a mismatch volume not progressing to infarction on one-month follow-up T2 fluid attenuated inversion recovery. Secondary end-points include: infarct growth (expansion of the diffusion-weighted imaging lesion) from baseline to the 24-h and one-month follow-up examination. Infarct growth inside and outside the acute perfusion-weighted imaging–diffusion-weighted imaging mismatch zone is quantified by use of coregistration. Clinical outcome after three-months. The influence of physical activity (Physical Activity Scale for the Elderly score) on effect of remote ischemic perconditioning. Feasibility of remote ischemic perconditioning in acute stroke patients.

Summary

This phase 3 trial is the first study in patients with acute ischemic stroke to evaluate the effect size of remote ischemic perconditioning as a pretreatment to intravenous alteplase, measured as penumbral salvage on multimodal magnetic resonance imaging and clinical outcome after three-months follow-up.

Novel plasmids and resistance phenotypes in Yersinia pestis: unique plasmid inventory of strain Java 9 mediates high levels of arsenic resistance

Growing evidence suggests that the plasmid repertoire of Yersinia pestis is not restricted to the three classical virulence plasmids. The Java 9 strain of Y. pestis is a biovar Orientalis isolate obtained from a rat in Indonesia. Although it lacks the Y. pestis-specific plasmid pMT, which encodes the F1 capsule, it retains virulence in mouse and non-human primate animal models. While comparing diverse Y. pestis strains using subtractive hybridization, we identified sequences in Java 9 that were homologous to a Y. enterocolitica strain carrying the transposon Tn2502, which is known to encode arsenic resistance. Here we demonstrate that Java 9 exhibits high levels of arsenic and arsenite resistance mediated by a novel promiscuous class II transposon, named Tn2503. Arsenic resistance was self-transmissible from Java 9 to other Y. pestis strains via conjugation. Genomic analysis of the atypical plasmid inventory of Java 9 identified pCD and pPCP plasmids of atypical size and two previously uncharacterized cryptic plasmids. Unlike the Tn2502-mediated arsenic resistance encoded on the Y. enterocolitica virulence plasmid; the resistance loci in Java 9 are found on all four indigenous plasmids, including the two novel cryptic plasmids. This unique mobilome introduces more than 105 genes into the species gene pool. The majority of these are encoded by the two entirely novel self-transmissible plasmids, which show partial homology and synteny to other enterics. In contrast to the reductive evolution in Y. pestis, this study underlines the major impact of a dynamic mobilome and lateral acquisition in the genome evolution of the plague bacterium.

Pain following stroke: a prospective study

BACKGROUND

Post-stroke pain is common and affects the quality of life of stroke survivors, but the incidence and severity of headache, shoulder pain, other joint pain and central post-stroke pain following stroke still remain unclear. The aim of this prospective study was to determine the incidence and intensity of these different types of post-stroke pain.

METHODS

A total of 299 consecutive stroke patients, admitted to the Department of Neurology at Aarhus University Hospital, underwent a structured interview and a short sensory examination within 4 days of admission. Follow-up was conducted by phone 3 and 6 months after stroke onset, with 275 patients completing the whole study. Pain with onset in relation to stroke onset or following stroke was defined as 'newly developed pain'.

RESULTS

At the 6-month follow-up, newly developed pain was reported by 45.8% of the patients; headache by 13.1%, shoulder pain by 16.4%, other joint pain by 11.7%, other pain by 20.0% and evoked pain by light touch or thermal stimuli by 8.0%. More than one pain type was reported by 36.5% of the patients with newly developed pain. According to pre-defined criteria, 10.5% of the patients were classified as having possible central post-stroke pain. There was a moderate to severe impact on daily life in 33.6% of the patients with newly developed pain.

CONCLUSIONS

Pain following stroke is common, with almost half of the patients reporting newly developed pain 6 months after stroke.

Bacterial diversity of terrestrial crystalline volcanic rocks, Iceland

Bacteria inhabiting crystalline rocks from two terrestrial Icelandic volcanic lava flows of similar age and from the same geographical region, but differing in porosity and mineralogy, were characterised. Microarray (PhyloChip) and clone library analysis of 16S rRNA genes revealed the presence of a diverse assemblage of bacteria in each lava flow. Both methods suggested a more diverse community at the Dómadalshraun site (rhyolitic/andesitic lava flow) than that present at the Hnausahraun site (basaltic lava flow). Proteobacteria dominated the clone library at the Dómadalshraun site, while Acidobacteria was the most abundant phylum in the Hnausahraun site. Although analysis of similarities of denaturing gradient gel electrophoresis profiles suggested a strong correlation of community structure with mineralogy, rock porosity may also play an important role in shaping the bacterial community in crystalline volcanic rocks. Clone sequences were most similar to uncultured microorganisms, mainly from soil environments. Of these, Antarctic soils and temperate rhizosphere soils were prominent, as were clones retrieved from Hawaiian and Andean volcanic soils. The novel diversity of these Icelandic microbial communities was supported by the finding that up to 46% of clones displayed <85% sequence identities to sequences currently deposited in the RDP database.

Low risk of vascular events following urgent treatment of transient ischaemic attack: the Aarhus TIA study

BACKGROUND AND PURPOSE

Patients with TIA have a high short-time risk of stroke and an increased long-term risk of ischaemic vascular events compared with the general population. Urgent intervention may reduce short-time stroke risk, but little is known about the effect beyond 3 months. We examined 1-year outcome and risk factor management in patients with TIA after urgent intervention.

METHODS

All patients with TIA referred to Aarhus University Hospital 1 March 2007-28 February 2008 were seen by an acute TIA team (ATT), integrating outpatient care and stroke unit facilities. Preventive treatment was initiated immediately, including fast-track surgery for carotid stenosis. Follow-up including nurse-conducted health counseling was carried out after 7, 90, and 365 days.

RESULTS

A total of 306 patients were included. Stroke, myocardial infarction, or vascular death occurred in 5.2% during 1 year of follow-up. The cumulated stroke rate was 1.6%, 2.0%, and 4.4% after 7, 90, and 365 days, respectively, compared to expected 4.5% [relative risk (RR) 0.36, 95% CI 0.13-0.98] and 7.5% (RR 0.26, 95% CI 0.11-0.63) after 7 and 90 days using ABCD(2) criteria. Recurrent TIA occurred in 10.2% (n = 32). Secondary prevention targets were attained in 47.6% after 1 year. Carotid surgery was performed in 8.1%; median time to operation was 11 days after contact with the ATT.

CONCLUSION

Urgent intervention after TIA by an ATT covering outpatient and stroke unit facilities combined with nurse-conducted health counseling is associated with a low 1-year risk of new vascular events and may improve risk factor control.

Systemic thrombolytic therapy alone and in combination with mechanical revascularization in acute ischemic stroke in two children

Thrombolytic therapy is not recommended for acute ischemic stroke (AIS) in patients under the age of 18 and published experience is limited. In this case report, we describe two children treated with systemic thrombolytic therapy. One child received additional mechanical revascularization and achieved a good clinical outcome. The differences in the fibrinolytic system and the different etiology of AIS in childhood may limit a simple extrapolation of the adult guidelines for systemic thrombolytic therapy. Acute multimodal imaging to clarify the etiology of AIS might help to select the most appropriate treatment modality.

Functional biogeography as evidence of gene transfer in hypersaline microbial communities

BACKGROUND

Horizontal gene transfer (HGT) plays a major role in speciation and evolution of bacteria and archaea by controlling gene distribution within an environment. However, information that links HGT to a natural community using relevant population-genetics parameters and spatial considerations is scarce. The Great Salt Lake (Utah, USA) provides an excellent model for studying HGT in the context of biogeography because it is a contiguous system with dispersal limitations due to a strong selective salinity gradient. We hypothesize that in spite of the barrier to phylogenetic dispersal, functional characteristics--in the form of HGT--expand beyond phylogenetic limitations due to selective pressure.

METHODOLOGY AND RESULTS

To assay the functional genes and microorganisms throughout the GSL, we used a 16S rRNA oligonucleotide microarray (Phylochip) and a functional gene array (GeoChip) to measure biogeographic patterns of nine microbial communities. We found a significant difference in biogeography based on microarray analyses when comparing Sørensen similarity values for presence/absence of function and phylogeny (Student's t-test; p = 0.005).

CONCLUSION AND SIGNIFICANCE

Biogeographic patterns exhibit behavior associated with horizontal gene transfer in that informational genes (16S rRNA) have a lower similarity than functional genes, and functional similarity is positively correlated with lake-wide selective pressure. Specifically, high concentrations of chromium throughout GSL correspond to an average similarity of chromium resistance genes that is 22% higher than taxonomic similarity. This suggests active HGT may be measured at the population level in microbial communities and these biogeographic patterns may serve as a model to study bacteria adaptation and speciation.

Ribosylurea accumulates in yeast urc4 mutants

Yeast Saccharomyces (Lachancea) kluyveri urc4 mutants, unable to grow on uracil, biotransformed (14)C(2)-uracil into two labeled compounds, as detected by high performance liquid chromatography (HPLC). These two compounds could also be obtained following organic synthesis of ribosylurea. This finding demonstrates that in the URC pyrimidine degradation pathway, the opening of the uracil ring takes place when uracil is attached to the ribose moiety. Ribosylurea has not been reported in the cell metabolism before and the two observed compounds likely represent an equilibrium mixture of the pyranosyl and furanosyl forms.