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Arrhythmia discrimination using a smart phone

Wed, 07/20/2016 - 9:50am

We hypothesize that our smartphone-based arrhythmia discrimination algorithm with data acquisition approach reliably differentiates between normal sinus rhythm (NSR), atrial fibrillation (AF), premature ventricular contractions (PVCs) and premature atrial contraction (PACs) in a diverse group of patients having these common arrhythmias. We combine root mean square of successive RR differences and Shannon entropy with Poincare plot (or turning point ratio method) and pulse rise and fall times to increase the sensitivity of AF discrimination and add new capabilities of PVC and PAC identification. To investigate the capability of the smartphone-based algorithm for arrhythmia discrimination, 99 subjects, including 88 study participants with AF at baseline and in NSR after electrical cardioversion, as well as seven participants with PACs and four with PVCs were recruited. Using a smartphone, we collected 2-min pulsatile time series from each recruited subject. This clinical application results show that the proposed method detects NSR with specificity of 0.9886, and discriminates PVCs and PACs from AF with sensitivities of 0.9684 and 0.9783, respectively.

Combined measure of neighborhood food and physical activity environments and weight-related outcomes: The CARDIA study

Wed, 07/20/2016 - 9:49am

Engagement in healthy lifestyle behaviors likely reflects access to a diverse and synergistic set of food and physical activity resources, yet most research examines discrete characteristics. We characterized neighborhoods with respect to their composition of features, and quantified associations with diet, physical activity (PA), body mass index (BMI), and insulin resistance (IR) in a longitudinal biracial cohort (n=4143; aged 25-37; 1992-2006). We used latent class analysis to derive population-density-specific ( < vs. > /=1750 people per sq km) clusters of neighborhood indicators: road connectivity, parks and PA facilities, and food stores/restaurants. In lower population density areas, a latent class with higher food and PA resource diversity (relative to other clusters) was significantly associated with higher diet quality. In higher population density areas, a cluster with relatively more natural food/specialty stores; fewer convenience stores; and more PA resources was associated with higher diet quality. Neighborhood clusters were inconsistently associated with BMI and IR, and not associated with fast food consumption, walking, biking, or running.

Sleep disturbance and longitudinal risk of inflammation: Moderating influences of social integration and social isolation in the Coronary Artery Risk Development in Young Adults (CARDIA) study

Wed, 07/20/2016 - 9:49am

Both sleep disturbance and social isolation increase the risk for morbidity and mortality. Systemic inflammation is suspected as a potential mechanism of these associations. However, the complex relationships between sleep disturbance, social isolation, and inflammation have not been examined in a population-based longitudinal study. This study examined the longitudinal association between sleep disturbance and systemic inflammation, and the moderating effects of social isolation on this association. The CARDIA study is a population-based longitudinal study conducted in four US cities. Sleep disturbance - i.e., insomnia complaints and short sleep duration - was assessed in 2962 African-American and White adults at baseline (2000-2001, ages 33-45years). Circulating C-reactive protein (CRP) was measured at baseline and follow-up (2005-2006). Interleukin-6 (IL-6) and subjective and objective social isolation (i.e., feelings of social isolation and social network size) were measured at follow-up. Sleep disturbance was a significant predictor of inflammation five years later after full adjustment for covariates (adjusted betas: 0.048, P=0.012 for CRP; 0.047, P=0.017 for IL-6). Further adjustment for baseline CRP revealed that sleep disturbance also impacted the longitudinal change in CRP levels over five years (adjusted beta: 0.044, P=0.013). Subjective social isolation was a significant moderator of this association between sleep disturbance and CRP (adjusted beta 0.131, P=0.002). Sleep disturbance was associated with heightened systemic inflammation in a general population over a five-year follow-up, and this association was significantly stronger in those who reported feelings of social isolation. Clinical interventions targeting sleep disturbances may be a potential avenue for reducing inflammation, particularly in individuals who feel socially isolated.

Neighborhood availability of convenience stores and diet quality: findings from 20 years of follow-up in the coronary artery risk development in young adults study

Wed, 07/20/2016 - 9:49am

OBJECTIVES: We examined the association between neighborhood convenience stores and diet outcomes for 20 years of the Coronary Artery Risk Development in Young Adults study.

METHODS: We used dietary data from the Coronary Artery Risk Development in Young Adults study years 1985-1986, 1992-1993, and 2005-2006 (n = 3299; Birmingham, AL; Chicago, IL; Minneapolis, MN; and Oakland, CA) and geographically and temporally matched neighborhood-level food resource and US Census data. We used random effects repeated measures regression to estimate associations between availability of neighborhood convenience stores with diet outcomes and whether these associations differed by individual-level income.

RESULTS: In multivariable-adjusted analyses, greater availability of neighborhood convenience stores was associated with lower diet quality (mean score = 66.3; SD = 13.0) for participants with lower individual-level income (b = -2.40; 95% CI = -3.30, -1.51); associations at higher individual-level income were weaker. We observed similar associations with whole grain consumption across time but no statistically significant associations with consumption of sugar-sweetened beverages, artificially sweetened beverages, snacks, processed meats, fruits, or vegetables.

CONCLUSIONS: The presence of neighborhood convenience stores may be associated with lower quality diets. Low-income individuals may be most sensitive to convenience store availability.

Dyslexia and language impairment associated genetic markers influence cortical thickness and white matter in typically developing children

Wed, 07/20/2016 - 9:49am

Dyslexia and language impairment (LI) are complex traits with substantial genetic components. We recently completed an association scan of the DYX2 locus, where we observed associations of markers in DCDC2, KIAA0319, ACOT13, and FAM65B with reading-, language-, and IQ-related traits. Additionally, the effects of reading-associated DYX3 markers were recently characterized using structural neuroimaging techniques. Here, we assessed the neuroimaging implications of associated DYX2 and DYX3 markers, using cortical volume, cortical thickness, and fractional anisotropy. To accomplish this, we examined eight DYX2 and three DYX3 markers in 332 subjects in the Pediatrics Imaging Neurocognition Genetics study. Imaging-genetic associations were examined by multiple linear regression, testing for influence of genotype on neuroimaging. Markers in DYX2 genes KIAA0319 and FAM65B were associated with cortical thickness in the left orbitofrontal region and global fractional anisotropy, respectively. KIAA0319 and ACOT13 were suggestively associated with overall fractional anisotropy and left pars opercularis cortical thickness, respectively. DYX3 markers showed suggestive associations with cortical thickness and volume measures in temporal regions. Notably, we did not replicate association of DYX3 markers with hippocampal measures. In summary, we performed a neuroimaging follow-up of reading-, language-, and IQ-associated DYX2 and DYX3 markers. DYX2 associations with cortical thickness may reflect variations in their role in neuronal migration. Furthermore, our findings complement gene expression and imaging studies implicating DYX3 markers in temporal regions. These studies offer insight into where and how DYX2 and DYX3 risk variants may influence neuroimaging traits. Future studies should further connect the pathways to risk variants associated with neuroimaging/neurocognitive outcomes.

Long-term outcomes of secondary atrial fibrillation in the community: the Framingham Heart Study

Wed, 07/20/2016 - 9:49am

BACKGROUND: Guidelines have proposed that atrial fibrillation (AF) can occur as an isolated event, particularly when precipitated by a secondary, or reversible, condition. However, knowledge of long-term AF outcomes after diagnosis during a secondary precipitant is limited.

METHODS AND RESULTS: In 1409 Framingham Heart Study participants with new-onset AF, we examined associations between first-detected AF episodes occurring with and without a secondary precipitant and both long-term AF recurrence and morbidity. We selected secondary precipitants based on guidelines (surgery, infection, acute myocardial infarction, thyrotoxicosis, acute alcohol consumption, acute pericardial disease, pulmonary embolism, or other acute pulmonary disease). Among 439 patients (31%) with AF diagnosed during a secondary precipitant, cardiothoracic surgery (n=131 [30%]), infection (n=102 [23%]), noncardiothoracic surgery (n=87 [20%]), and acute myocardial infarction (n=78 [18%]) were most common. AF recurred in 544 of 846 eligible individuals without permanent AF (5-, 10-, and 15-year recurrences of 42%, 56%, and 62% with versus 59%, 69%, and 71% without secondary precipitants; multivariable-adjusted hazard ratio, 0.65 [95% confidence interval, 0.54-0.78]). Stroke risk (n=209/1262 at risk; hazard ratio, 1.13 [95% confidence interval, 0.82-1.57]) and mortality (n=1098/1409 at risk; hazard ratio, 1.00 [95% confidence interval, 0.87-1.15]) were similar between those with and without secondary precipitants, although heart failure risk was reduced (n=294/1107 at risk; hazard ratio, 0.74 [95% confidence interval, 0.56-0.97]).

CONCLUSIONS: AF recurs in most individuals, including those diagnosed with secondary precipitants. Long-term AF-related stroke and mortality risks were similar between individuals with and without secondary AF precipitants. Future studies may determine whether increased arrhythmia surveillance or adherence to general AF management principles in patients with reversible AF precipitants will reduce morbidity.

Mental health problems in young male offenders with and without sex offences: a comparison based on the MAYSI-2

Wed, 07/20/2016 - 9:49am

BACKGROUND: There is a need for better knowledge about the relationship between sexual offending by young people and mental health problems.

AIM: This study aimed to compare mental health problems between young people who commit sexual offences and those who do not.

METHODS: After completion of the Massachusetts Youth Screening Instrument-Version 2 (MAYSI-2), 334 young people who, according to MAYSI-2 information, had committed a sex offence were compared with 334 young people whose MAYSI-2 data suggested that they had not committed a sex offence. They were matched for age, race/ethnicity, type of facility and adjudication status. We also examined the young sex offenders for within group differences.

RESULTS: The young sex offenders were less likely to report anger-irritability or substance misuse than the comparison youths. Within the sex offender group, older juveniles were more likely to report alcohol and drug use problems than younger ones, Caucasians were more likely to report anger and suicidal ideation than their non-Caucasian peers, those detained were more likely to report alcohol and drug use problems and somatic complaints than those on probation, and convicted youths were more likely to report alcohol and drug use problems and anger-irritability than those awaiting trial.

CONCLUSIONS: Juvenile sexual offending seems less likely to be committed in the context of an anti-social lifestyle than other offending. Important findings among young sex offenders are their higher levels of mental health problems among those detained and convicted than among those on probation or awaiting trial. Assessment of the mental health of young sex offenders seems to be even more important the further they are into the justice system.

Change in emergency department providers' beliefs and practices after use of new protocols for suicidal patients

Wed, 07/20/2016 - 9:49am

OBJECTIVE: The study examined changes in self-reported attitudes and practices related to suicide risk assessment among providers at emergency departments (EDs) during a three-phase quasi-experimental trial involving implementation of ED protocols for suicidal patients.

METHODS: A total of 1,289 of 1,828 (71% response rate) eligible providers at eight EDs completed a voluntary, anonymous survey at baseline, after introduction of universal suicide screening, and after introduction of suicide prevention resources (nurses) and a secondary risk assessment tool (physicians).

RESULTS: Among participants, the median age was 40 years old, 64% were female, and there were no demographic differences across study phases; 68% were nurses, and 32% were attending physicians. Between phase 1 and phase 3, increasing proportions of nurses reported screening for suicide (36% and 95%, respectively, p < .001) and increasing proportions of physicians reported further assessment of suicide risk (63% and 80%, respectively, p < .01). Although increasing proportions of providers said universal screening would result in more psychiatric consultations, decreasing proportions said it would slow down clinical care. Increasing proportions of nurses reported often or almost always asking suicidal patients about firearm access (18%-69%, depending on the case), although these numbers remained low relative to ideal practice. Between 35% and 87% of physicians asked about firearms, depending on the case, and these percentages did not change significantly over the study phases.

CONCLUSIONS: These findings support the feasibility of implementing universal screening for suicide in EDs, assuming adequate resources, but providers should be educated to ask suicidal patients about firearm access.

Clinical Operations Variables are Associated With Blood Pressure Outcomes

Wed, 07/20/2016 - 9:49am

BACKGROUND: Uncontrolled blood pressure (BP), among patients diagnosed and treated for the condition, remains an important clinical challenge; aspects of clinical operations could potentially be adjusted if they were associated with better outcomes.

OBJECTIVES: To assess clinical operations factors' effects on normalization of uncontrolled BP.

RESEARCH DESIGN: Observational cohort study.

SUBJECTS: Patients diagnosed with hypertension from a large urban clinical practice (2005-2009).

MEASURES: We obtained clinical data on BP, organized by person-month, and administrative data on primary care provider (PCP) staffing. We assessed the resolution of an episode of uncontrolled BP as a function of time-varying covariates including practice-level appointment volume, individual clinicians' appointment volume, overall practice-level PCP staffing, and number of unique PCPs.

RESULTS: Among the 7409 unique patients representing 50,403 person-months, normalization was less likely for the patients in whom the episode starts during months when the number of unique PCPs were high [the top quintile of unique PCPs was associated with a 9 percentage point lower probability of normalization (P < 0.01) than the lowest quintile]. Practice appointment volume negatively affected the likelihood of normalization [episodes starting in months with the most appointments were associated with a 6 percentage point reduction in the probability of normalization (P=0.01)]. Neither clinician appointment volume nor practice clinician staffing levels were significantly associated with the probability of normalization.

CONCLUSIONS: Findings suggest that clinical operations factors can affect clinical outcomes like BP normalization, and point to the importance of considering outcome effects when organizing clinical care.

In patients stratified by preoperative risk, endovascular repair of ruptured abdominal aortic aneurysms has a lower in-hospital mortality and morbidity than open repair

Wed, 07/20/2016 - 9:49am

OBJECTIVE: Previous studies have reported that endovascular repair (EVAR) of ruptured abdominal aortic aneurysms (RAAAs) has lower postoperative mortality than open repair (OR). However, comparisons involved heterogeneous populations that lacked adjustment for preoperative risk. We hypothesize that for RAAA patients stratified by a validated measure of preoperative mortality risk, EVAR has a lower in-hospital mortality and morbidity than does OR.

METHODS: In-hospital mortality and morbidity after EVAR and OR of RAAA were compared in patients from the Vascular Quality Initiative (2003-2013) stratified by the validated Vascular Study Group of New England RAAA risk score into low-risk (score 0-1), medium-risk (score 2-3), and high-risk (score 4-6) groups.

RESULTS: Among 514 patients who underwent EVAR and 651 patients who underwent OR of RAAA, EVAR had lower in-hospital mortality (25% vs 33%, P = .001). In risk-stratified patients, EVAR trended toward a lower mortality in the low-risk group (n = 626; EVAR, 10% vs OR, 15%; P = .07), had a significantly lower mortality in the medium-risk group (n = 457; EVAR, 37% vs OR, 48%; P = .02), and no advantage in the high-risk group (n = 82; EVAR, 95% vs OR, 79%; P = .17). Across all risk groups, cardiac complications (EVAR, 29% vs OR, 38%; P = .001), respiratory complications (EVAR, 28% vs OR, 46%; P < .0001), renal insufficiency (EVAR, 24% vs OR, 38%; P < .0001), lower extremity ischemia (EVAR, 2.7% vs OR, 8.1%; P < .0001), and bowel ischemia (EVAR, 3.9% vs OR, 10%; P < .0001) were significantly lower after EVAR than after OR. Across all risk groups, median (interquartile range) intensive care unit length of stay (EVAR, 2 [1-5] days vs OR, 6 [3-13] days; P < .0001) and hospital length of stay (EVAR, 6 [4-12] days vs OR, 13 [8-22] days; P < .0001) were lower after EVAR.

CONCLUSIONS: This novel risk-stratified comparison using a national clinical database showed that EVAR of RAAA has a lower mortality and morbidity compared with OR in low-risk and medium-risk patients and that EVAR should be used to treat these patients when anatomically feasible. For RAAA patients at the highest preoperative risk, there is no benefit to using EVAR compared with OR.

Taking complaints seriously: using the patient safety lens

Wed, 07/20/2016 - 9:49am

Yet few healthcare institutions see patient complaints as adverse events. Instead, at most institutions, patient complaints are handled by patient relations or risk management departments, with a primary goal of mollifying the patient and avoiding litigation, missing the opportunity not only to meet the affected patients’ needs but also to improve the quality of care going forward by identifying root causes and developing prevention plans.

Social synchronization of circadian rhythmicity in female mice depends on the number of cohabiting animals

Wed, 07/20/2016 - 9:49am

Communal animals often engage in group activities that require temporal synchrony among its members, including synchrony on the circadian timescale. The principles and conditions that foster such collective synchronization are not understood, but existing literature hints that the number of interacting individuals may be a critical factor. We tested this by recording individual circadian body temperature rhythms of female house mice housed singly, in twos (pairs), or in groups of five (quintets) in constant darkness; determining the daily phases of the circadian peak for each animal; and then calculating the cycle-to-cycle phase relationship between cohabiting animals over time. Significant temporal coherence was observed in quintets: the proportion of quintets (4/7), but not pairs (2/8), that became synchronized was greater than could be achieved by the complete simulated reassortment of all individuals. We speculate that the social coupling of individual circadian clocks of group members may be adaptive under certain conditions, and we propose that optimal group sizes in nature may depend not only on species-specific energetics, spatial behaviour and natural history but also on the mathematics of synchronizing assemblies of weakly coupled animal oscillators.

Age and sex differences in long-term outcomes following implantable cardioverter-defibrillator placement in contemporary clinical practice: findings from the Cardiovascular Research Network

Wed, 07/20/2016 - 9:48am

BACKGROUND: Patient sex and age may influence rates of death after receiving an implantable cardioverter-defibrillator for primary prevention. Differences in outcomes other than mortality and whether these differences vary by heart failure symptoms, etiology, and left ventricular ejection fraction are not well characterized.

METHODS AND RESULTS: We studied 2954 patients with left ventricular ejection fraction < /=0.35 undergoing first-time implantable cardioverter-defibrillator for primary prevention within the Cardiovascular Research Network; 769 patients (26%) were women, and 2827 (62%) were aged > 65 years. In a median follow-up of 2.4 years, outcome rates per 1000 patient-years were 109 for death, 438 for hospitalization, and 111 for heart failure hospitalizations. Procedure-related complications occurred in 8.36%. In multivariable models, women had significantly lower risks of death (hazard ratio 0.67, 95% CI 0.56 to 0.80) and heart failure hospitalization (hazard ratio 0.82, 95% CI 0.68 to 0.98) and higher risks for complications (hazard ratio 1.38, 95% CI 1.01 to 1.90) than men; patients aged > 65 years had higher risks of death (hazard ratio 1.55, 95% CI 1.30 to 1.86) and heart failure hospitalization (hazard ratio 1.25, 95% CI 1.05 to 1.49) than younger patients. Age and sex differences were generally consistent in strata according to symptoms, etiology, and severity of left ventricular systolic dysfunction, except the higher risk of complications in women, which differed by New York Heart Association classification (P=0.03 for sex-New York Heart Association interaction), and the risk of heart failure hospitalization in older patients, which differed by etiology of heart failure (P=0.05 for age-etiology interaction).

CONCLUSIONS: The burden of adverse outcomes after receipt of an implantable cardioverter-defibrillator for primary prevention is substantial and varies according to patient age and sex. These differences in outcome generally do not vary according to baseline heart failure characteristics.

Patient Portals: An Underused Resource for Improving Patient Engagement

Wed, 07/20/2016 - 9:48am

The potential of patient portals to improve patient engagement and health outcomes has been discussed for more than a decade. The slow growth in patient portal adoption rates among patients and providers in the United States, despite external incentives, indicates that this is a complex issue. We examined evidence of patient portal use and effects with a focus on the pulmonary domain. We found a paucity of studies of patient portal use in pulmonary practice, and highlight gaps for future research. We also report on the experience of a pulmonary department using a patient portal to highlight the potential of these systems. Inc.

Hepatocellular Carcinoma Recurrence Pattern Following Liver Transplantation and a Suggested Surveillance Algorithm

Tue, 07/19/2016 - 3:28pm

Purpose: Evaluate the recurrence pattern of hepatocellular carcinoma (HCC) following liver transplantation.

Materials and Methods: A total of 54 patients underwent liver transplantation for HCC; 9 patients developed biopsy proven recurrent HCC (16.6%). The site of HCC recurrence along with other factors were analyzed.

Results: Seven patients were diagnosed with HCC prior to liver transplantation and 2 patients had incidental HCC in the explanted liver. Two patients had locoregional recurrence, 4 patients had distant metastasis and 3 patients had synchronous locoregional recurrence and distant metastasis.

Conclusion: A significant proportion of HCC recurrence following liver transplantation is extrahepatic.

Case of the Week: A 51-year-old Man with Headaches and Visual Disturbances

Tue, 07/19/2016 - 3:27pm

"Case of the Week" for the American Journal of Neuroradiology, with the following description: Sagittal T1WI pre- (A) and postcontrast (B) show a large, lobulated, heterogeneously-enhancing pituitary mass that expands the sella and demonstrates a suprasellar extension. Axial (C) and sagittal (D) T2WI demonstrate diffuse thickening of the calvarium with heterogeneous marrow signal. Axial (E) and coronal (F) noncontrast CT through the level of the parathyroid gland demonstrate hypodense nodules posterior and inferior to the thyroid lobes (arrows).

MCQs in Neuroradiology: Brain and Physics

Tue, 07/19/2016 - 3:27pm

Version 1.4 of this book contains 500 multiple choice questions (MCQs) in Neuroradiology dealing with subjects of brain and physics, to assist in preparing for certification exams. The MCQs are organized into easy, intermediate and difficult categories. The answer page covers not only the topic of the MCQ but also the related material. The MCQs have been prepared mostly from the review articles especially RadioGraphics.

Discovery and Reuse of Open Datasets: An Exploratory Study

Tue, 07/19/2016 - 8:56am

Objective: This article analyzes twenty cited or downloaded datasets and the repositories that house them, in order to produce insights that can be used by academic libraries to encourage discovery and reuse of research data in institutional repositories.

Methods: Using Thomson Reuters’ Data Citation Index and repository download statistics, we identified twenty cited/downloaded datasets. We documented the characteristics of the cited/downloaded datasets and their corresponding repositories in a self-designed rubric. The rubric includes six major categories: basic information; funding agency and journal information; linking and sharing; factors to encourage reuse; repository characteristics; and data description.

Results: Our small-scale study suggests that cited/downloaded datasets generally comply with basic recommendations for facilitating reuse: data are documented well; formatted for use with a variety of software; and shared in established, open access repositories. Three significant factors also appear to contribute to dataset discovery: publishing in discipline-specific repositories; indexing in more than one location on the web; and using persistent identifiers. The cited/downloaded datasets in our analysis came from a few specific disciplines, and tended to be funded by agencies with data publication mandates.

Conclusions: The results of this exploratory research provide insights that can inform academic librarians as they work to encourage discovery and reuse of institutional datasets. Our analysis also suggests areas in which academic librarians can target open data advocacy in their communities in order to begin to build open data success stories that will fuel future advocacy efforts.

TAD disruption as oncogenic driver

Thu, 07/14/2016 - 9:21pm

Topologically Associating Domains (TADs) are conserved during evolution and play roles in guiding and constraining long-range regulation of gene expression. Disruption of TAD boundaries results in aberrant gene expression by exposing genes to inappropriate regulatory elements. Recent studies have shown that TAD disruption is often found in cancer cells and contributes to oncogenesis through two mechanisms. One mechanism locally disrupts domains by deleting or mutating a TAD boundary leading to fusion of the two adjacent TADs. The other mechanism involves genomic rearrangements that break up TADs and creates new ones without directly affecting TAD boundaries. Understanding the mechanisms by which TADs form and control long-range chromatin interactions will therefore not only provide insights into the mechanism of gene regulation in general, but will also reveal how genomic rearrangements and mutations in cancer genomes can lead to misregulation of oncogenes and tumor suppressors.