bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-reported Chronic Pain in Young Adults With a Low Birth Weight
Authors: Iversen Johanne M. , Indredavik Marit S. , Evensen Kari A.I. , Romundstad Pål R. , Rygg Marite
Published: August 2016

Objective:

To investigate self-reported pain in young adults with a low birth weight.

Materials and Methods:

This study was a part of a long-term follow-up study of preterm very low birth weight (VLBW; birth weight ≤1500 g), term small for gestational age (SGA; birth weight <10th percentile adjusted for sex and parity), and control young adults born during 1986 to 1988. Of the 300 individuals invited, 216 (62 VLBW, 67 term SGA, and 87 controls) completed a pain questionnaire. Of these, 151 (70%) had answered a pain severity question at 19 years. Chronic pain was defined as pain lasting for >6 months and being moderate, severe, or very severe during the past 4 weeks.

Results:

The prevalence of chronic pain at 26 years was 16% in the VLBW group, 21% in the term SGA group, and 7% in the control group. The VLBW and the term SGA groups had higher odds ratios for chronic pain (crude OR, 2.6; 95% CI, 0.9-7.6 for the VLBW group and crude OR, 3.6; 95% CI, 1.3-9.9 for the term SGA group vs. controls). The main results remained after adjusting for potential confounding factors. Some attenuation was observed when adjusting for anxiety and depressive problems. Moderate to very severe pain increased from 16% to 41% in the term SGA group from 19 to 26 years, whereas less changes were seen in the VLBW and the control groups.

Discussion:

Results of our study imply that pain should be in focus when conducting long-term follow-up programs of individuals with a low birth weight.
Pain and Function in Home Care
Authors: Murtaugh Christopher M. , Beissner Katherine L. , Barrón Yolanda , Trachtenberg Melissa A. , Bach Eileen , Henderson Charles R. , Sridharan Sridevi , Reid Manny C.
Published: August 2016

Objectives:

To describe racial/ethnic group differences in pain presentation and the prevalence of psychosocial factors among patients admitted to home health care, and to determine the extent of racial/ethnic group differences in the association of psychosocial factors with pain intensity and pain-related disability.

Methods:

We analyzed cross-sectional data on 588 patients with activity-limiting pain admitted to home care for physical therapy. Three psychosocial factors were assessed: depressive symptoms, pain self-efficacy, and health literacy. Statistical methods included estimation of general linear models of pain intensity and pain-related disability.

Results:

Hispanics and non-Hispanic blacks report a greater number of pain sites, worse pain intensity, and higher levels of pain-related disability than non-Hispanic whites and others. Racial/ethnic minority group patients also have a higher prevalence of adverse psychosocial factors than others, with evidence that race/ethnicity interacts with pain self-efficacy and depressive symptoms in their association with mean pain intensity and pain-related disability, respectively.

Discussion:

The substantial racial/ethnic difference in the psychosocial profiles of older adults with activity-limiting pain highlights the importance of screening for these modifiable risk factors and tailoring interventions accordingly. Direct attention to the psychosocial needs of patients could help to address racial/ethnic disparities in pain outcomes.
Exercise-induced Hypoalgesia in People With Knee Osteoarthritis With Normal and Abnormal Conditioned Pain Modulation
Authors: Fingleton Caitríona , Smart Keith M. , Doody Catherine M.
Published: August 2016

Objectives:

Normal efficiency of exercise-induced hypoalgesia (EIH) has been demonstrated in people with knee osteoarthritis (OA), while recent evidence suggests that EIH may be associated with features of pain sensitization such as abnormal conditioned pain modulation (CPM). The aim of this study was to investigate whether people with knee OA with abnormal CPM have dysfunctional EIH compared with those with normal CPM and pain-free controls.

Methods:

Forty peoples with knee OA were subdivided into groups with abnormal and normal CPM, as determined by a decrease/increase in pressure pain thresholds (PPTs) following the cold pressor test. Abnormal CPM (n=19), normal CPM (n=21), and control participants (n=20) underwent PPT testing before, during, and after aerobic and isometric exercise protocols. Between-group differences were analyzed using repeated-measures analysis of variance and within-group differences were analyzed using Wilcoxon signed-rank tests.

Results:

Significant differences were demonstrated between groups for changes in PPTs postaerobic (F
2,55=4.860; P=0.011) and isometric (F
2,57=4.727; P=0.013) exercise, with significant decreases in PPTs demonstrated during and postexercise in the abnormal CPM group (P<0.05), and significant increases in PPTs shown during and postexercise in the normal CPM and control groups (P<0.05).

Conclusions:

Results are suggestive of dysfunctional EIH in response to aerobic and isometric exercise in knee OA patients with abnormal CPM, and normal function of EIH in knee OA patients with an efficient CPM response. Identification of people with knee OA with inefficient endogenous pain modulation may allow for a more individualized and graded approach to exercises in these individuals.
Mindfulness-Based Intervention Does Not Influence Cardiac Autonomic Control or the Pattern of Physical Activity in Fibromyalgia During Daily Life
Authors: Grossman Paul , Deuring Gunnar , Walach Harald , Schwarzer Barbara , Schmidt Stefan
Published: August 2016

Objectives:

Fibromyalgia (FM) is a syndrome characterized by severe pain, fatigue and sleep disturbance. There is evidence of central hyper-responsiveness to sensory stimulation and impaired cardiovascular autonomic control. Laboratory investigations suggest that mindfulness-based stress reduction (MBSR) may improve autonomic functioning in FM. However, these findings may not reflect what occurs during naturalistic conditions, and MBSR studies during real-life functioning are lacking. We conducted a randomized controlled, 3-armed study with 168 female FM patients. This report describes cardiac, respiratory, and physical activity findings.

Methods:

Eight-week MBSR was compared with wait-list and active control intervention. Ambulatory accelerometry and cardiorespiratory function were monitored over 24-h periods at 3 time points: preintervention, postintervention, and at the 8-week follow-up. Also, baseline levels were compared with an age-matched group of 33 healthy women.

Findings:

Activity heart rate, respiratory sinus arrhythmia, and ventilation were measured. Comparison with controls confirmed differences in cardiac autonomic tone and activity pattern among patients. Most measures also showed effects of time of day and point of measurement. Regarding the intervention study, there were no effects of treatment. In addition, there were no relations between patient-reported clinical improvement and objective physiological or accelerometry parameters. Intervention-related benefits in wellbeing were not associated with changes in daytime cardiorespiratory measures or pattern of physical activity.

Conclusions:

MBSR did not produce cardiac autonomic benefits or changes in daily activity in FM. Furthermore, the lack of an association between patient-experienced clinical improvement and objective physiological measures suggests that subjective changes in the wellbeing of FM patients over time are not related to alterations in the cardiorespiratory autonomic function or activity levels.
How Reliable Are the Reported Genetic Associations in Disc Degeneration?
Authors: Rajasekaran S. , Kanna Rishi Mugesh , Reddy Ranjani Raja , Natesan Senthil , Raveendran Muthuraja , Cheung Kenneth M.C. , Chan Danny , Kao Patrick Y.P. , Yee Anita , Shetty Ajoy Prasad
Published: August 2016

Study Design.

Prospective genetic association study.

Objective.

The aim of this study was to document the variations in the genetic associations, when different magnetic resonance imaging (MRI) phenotypes, age stratification, cohort size, and sequence of cohort inclusion are varied in the same study population.

Summary of Background Data.

Genetic associations with disc degeneration have shown high inconsistency, generally attributed to hereditary factors and ethnic variations. However, the effect of different phenotypes, size of the study population, age of the cohort, etc have not been documented clearly.

Methods.

Seventy-one single-nucleotide polymorphisms (SNPs) of 41 candidate genes were correlated to six MRI markers of disc degeneration (annular tears, Pfirmann grading, Schmorl nodes, Modic changes, Total Endplate Damage score, and disc bulge) in 809 patients with back pain and/or sciatica. In the same study group, the correlations were then retested for different age groups, different sample, size and sequence of subject inclusion (first 404 and the second 405) and the differences documented.

Results.

The mean age of population (M: 455, F: 354) was 36.7 ± 10.8 years. Different genetic associations were found with different phenotypes: disc bulge with three SNPs of CILP; annular tears with rs2249350 of ADAMTS5 and rs11247361 IGF1R; modic changes with VDR and MMP20; Pfirmann grading with three SNPs of MMP20 and Schmorl node with SNPs of CALM1 and FN1 and none with Total End Plate Score.

Subgroup analysis based on three age groups and dividing the total population into two groups also completely changed the associations for all the six radiographic parameters.

Conclusion.

In the same study population, SNP associations completely change with different phenotypes. Variations in age, inclusion sequence, and sample size resulted in change of genetic associations. Our study questions the validity of previous studies and necessitates the need for standardizing the description of disc degeneration, phenotype selection, study sample size, age, and other variables in future studies.

Level of Evidence: 4
Can C3 Laminectomy Reduce Interlaminar Bony Fusion and Preserve the Range of Motion After Cervical Laminoplasty?
Authors: Lee Dong-Ho , Cho Jae Hwan , Hwang Chang Ju , Lee Choon Sung , Cho Samuel K. , Ha Jung-Ki
Published: August 2016

Study Design.

Retrospective comparative study.

Objective.

To investigate whether the resection of C3 lamina during cervical laminoplasty can prevent C2-C4 interlaminar bony fusion and preserve the range of motion (ROM) postoperatively.

Summary of Background Data.

Interlaminar bony fusion is a common complication after cervical laminoplasty, especially in the C2-C4. Laminectomy, rather than laminoplasty, of C3 has been recently introduced. Its advantages include minimizing muscle detachment at C2 and reducing postoperative neck pain.

Methods.

A total of 59 patients with cervical spondylotic myelopathy that involved three or more levels, including C3, were consecutively treated with laminoplasty and followed up for more than 3 years after surgery. The first 45 patients underwent open-door laminoplasty at C3 (Lp group) and the subsequent 14 patients underwent laminectomy at C3 rather than laminoplasty (Ln group). The Lp group was further divided into two subgroups based on the development of interlaminar bony fusion at C2-C3 and/or C3-C4: Lp-NF (nonfusion) and Lp-F (fusion) groups. Clinical outcomes and radiographic parameters were assessed pre- and postoperatively.

Results.

Nineteen out of 45 patients who underwent laminoplasty demonstrated fusion at 3-year follow up. Fusion developed more commonly in those patients who had a smaller preoperative ROM at C2-C4 segments (Lp-F 14.3° ± 6.9° vs. Lp-NF 21.4° ± 5.3°, P = 0.013). The neck disability index (range, 13.4 ± 7.3 to 6.3 ± 5.2, P < 0.001), visual analog scale for neck pain (range, 2.5 ± 1.7 to 0.9 ± 1.3, P = 0.027), Japanese Orthopedic Association (JOA) score (range, 14.3 ± 1.9 to 16.0 ± 2.4, P < 0.001), and JOA recovery rate (63.4 ± 19.8%) in the Ln group improved postoperatively; however, there was no significant difference in the improvement of these clinical outcomes among all three groups. Postoperative cervical ROM was significantly reduced in all groups; however, the extent of reduction was significantly smaller in the Ln group (10.5°; range, 44.2° ± 9.1° to 33.7 ± 6.0°) than in the Lp-NF (15.1°; range, 45.4° ± 8.5° to 30.3° ± 7.4°) or Lp-F (18.2°; range, 39.6° ± 9.3° to 21.4° ± 10.3°) groups (P < 0.05).

Conclusion.

C3 laminectomy with laminoplasty can prevent interlaminar bony fusion at C2-C4 and, ultimately, result in better preservation of cervical ROM than C3 laminoplasty. Furthermore, it yields similar clinical outcomes when compared with C3 laminoplasty.

Level of Evidence: 3
Neuromuscular Recovery Is Prolonged After Immobilization or Superimposition of Inflammation With Immobilization Compared to Inflammation Alone: Data From a Preclinical Model
Authors: Stäuble Christiane G. , Helming Marc , Martyn J. A. Jeevendra , Blobner Manfred , Fink Heidrun
Published: August 2016

Objectives:

Recovery from ICU-acquired muscle weakness extends beyond hospital stay. We hypothesized that immobilization, more than inflammation, plays a prominent role in the delayed recovery from critical illness.

Design:

Prospective, randomized, controlled, experimental study.

Setting:

Animal laboratory, university hospital.

Subjects:

Male Sprague-Dawley rats.

Interventions:

Animals were divided to have one hind limb immobilized (n = 129) or sham-immobilized (n = 129) on day –12. After surgery, rats were further assigned to two subgroups. To induce inflammation, rats received three IV injections of Corynebacterium parvum on days –12, –8, and –4. Controls received saline at the respective time-points. At day 0, the limbs were remobilized and recovery from inflammation and/or immobilization was followed for 36 days.

Measurements and Main Results:

At day 0 and after 4, 12, or 36 days of recovery, maximum tetanic tension and tetanic fade (functional parameters = primary outcome variables) as well as nicotinic acetylcholine receptor expression, muscle mass, and histologic changes (structural parameters = secondary outcome variables) were measured. Impaired maximum tetanic tension, decreased tibialis muscle mass, and fiber diameter due to inflammation alone recovered by day 4. Tetanic fade was not affected by inflammation. Immobilization-induced loss of tibialis muscle mass, decreased fiber diameter, and tetanic fade did not return to normal until day 36, while maximum tetanic tension had recovered at that time. In the presence of inflammation and immobilization, the decrease in tibialis muscle mass, fiber diameter, and maximum tetanic tension, as well as decreased tetanic fade persisted until day 36. Up-regulation of nicotinic acetylcholine receptors normalized before day 4 following inflammation, but persisted until day 4 following immobilization.

Conclusions:

In our model, muscle function and structure recovered from inflammation within 4–12 days. Immobilization-induced neuromuscular changes, however, persisted even at day 36, especially if inflammation was concomitant.
Incidence and Characteristics of Ventilator-Associated Events Reported to the National Healthcare Safety Network in 2014*
Authors: Magill Shelley S. , Li Qunna , Gross Cindy , Dudeck Margaret , Allen-Bridson Katherine , Edwards Jonathan R.
Published: August 2016

Objective:

Ventilator-associated event surveillance was introduced in the National Healthcare Safety Network in 2013, replacing surveillance for ventilator-associated pneumonia in adult inpatient locations. We determined incidence rates and characteristics of ventilator-associated events reported to the National Healthcare Safety Network.

Design, Setting, and Patients:

We analyzed data reported from U.S. healthcare facilities for ventilator-associated events that occurred in 2014, the first year during which ventilator-associated event surveillance definitions were stable. We used negative binomial regression modeling to identify healthcare facility and inpatient location characteristics associated with ventilator-associated events. We calculated ventilator-associated event incidence rates, rate distributions, and ventilator utilization ratios in critical care and noncritical care locations and described event characteristics.

Measurements and Main Results:

A total of 1,824 healthcare facilities reported 32,772 location months of ventilator-associated event surveillance data to the National Healthcare Safety Network in 2014. Critical care unit pooled mean ventilator-associated event incidence rates ranged from 2.00 to 11.79 per 1,000 ventilator days, whereas noncritical care unit rates ranged from 0 to 14.86 per 1,000 ventilator days. The pooled mean proportion of ventilator-associated events defined as infection-related varied from 15.38% to 47.62% in critical care units. Pooled mean ventilator utilization ratios in critical care units ranged from 0.24 to 0.47.

Conclusions:

We found substantial variability in ventilator-associated event incidence, proportions of ventilator-associated events characterized as infection-related, and ventilator utilization within and among location types. More work is needed to understand the preventable fraction of ventilator-associated events and identify patient care strategies that reduce ventilator-associated events.
Lung Injury Prediction Score in Hospitalized Patients at Risk of Acute Respiratory Distress Syndrome
Authors: Soto Graciela J. , Kor Daryl J. , Park Pauline K. , Hou Peter C. , Kaufman David A. , Kim Mimi , Yadav Hemang , Teman Nicholas , Hsu Michael C. , Shvilkina Tatyana , Grewal Yekaterina , De Aguirre Manuel , Gunda Sampath , Gajic Ognjen , Gong Michelle Ng
Published: August 2016

Objective:

The Lung Injury Prediction Score identifies patients at risk for acute respiratory distress syndrome in the emergency department, but it has not been validated in non-emergency department hospitalized patients. We aimed to evaluate whether Lung Injury Prediction Score identifies non-emergency department hospitalized patients at risk of developing acute respiratory distress syndrome at the time of critical care contact.

Design:

Retrospective study.

Setting:

Five academic medical centers.

Patients:

Nine hundred consecutive patients (≥ 18 yr old) with at least one acute respiratory distress syndrome risk factor at the time of critical care contact.

Interventions:

None.

Measurements and Main Results:

Lung Injury Prediction Score was calculated using the worst values within the 12 hours before initial critical care contact. Patients with acute respiratory distress syndrome at the time of initial contact were excluded. Acute respiratory distress syndrome developed in 124 patients (13.7%) a median of 2 days (interquartile range, 2–3) after critical care contact. Hospital mortality was 22% and was significantly higher in acute respiratory distress syndrome than non-acute respiratory distress syndrome patients (48% vs 18%; p < 0.001). Increasing Lung Injury Prediction Score was significantly associated with development of acute respiratory distress syndrome (odds ratio, 1.31; 95% CI, 1.21–1.42) and the composite outcome of acute respiratory distress syndrome or death (odds ratio, 1.26; 95% CI, 1.18–1.34). A Lung Injury Prediction Score greater than or equal to 4 was associated with the development of acute respiratory distress syndrome (odds ratio, 4.17; 95% CI, 2.26–7.72), composite outcome of acute respiratory distress syndrome or death (odds ratio, 2.43; 95% CI, 1.68–3.49), and acute respiratory distress syndrome after accounting for the competing risk of death (hazard ratio, 3.71; 95% CI, 2.05–6.72). For acute respiratory distress syndrome development, the Lung Injury Prediction Score has an area under the receiver operating characteristic curve of 0.70 and a Lung Injury Prediction Score greater than or equal to 4 has 90% sensitivity (misses only 10% of acute respiratory distress syndrome cases), 31% specificity, 17% positive predictive value, and 95% negative predictive value.

Conclusions:

In a cohort of non-emergency department hospitalized patients, the Lung Injury Prediction Score and Lung Injury Prediction Score greater than or equal to 4 can identify patients at increased risk of acute respiratory distress syndrome and/or death at the time of critical care contact but it does not perform as well as in the original emergency department cohort.
Acute Kidney Injury in Pediatric Severe Sepsis: An Independent Risk Factor for Death and New Disability
Authors: Fitzgerald Julie C. , Basu Rajit K. , Akcan-Arikan Ayse , Izquierdo Ledys M. , Piñeres Olave Byron E. , Hassinger Amanda B. , Szczepanska Maria , Deep Akash , Williams Duane , Sapru Anil , Roy Jason A. , Nadkarni Vinay M. , Thomas Neal J. , Weiss Scott L. , Furth Susan
Published: August 2016

Objectives:

The prevalence of septic acute kidney injury and impact on functional status of PICU survivors are unknown. We used data from an international prospective severe sepsis study to elucidate functional outcomes of children suffering septic acute kidney injury.

Design:

Secondary analysis of patients in the Sepsis PRevalence, OUtcomes, and Therapies point prevalence study: acute kidney injury was defined on the study day using Kidney Disease Improving Global Outcomes definitions. Patients with no acute kidney injury or stage 1 acute kidney injury (“no/mild acute kidney injury”) were compared with those with stage 2 or 3 acute kidney injury (“severe acute kidney injury”). The primary outcome was a composite of death or new moderate disability at discharge defined as a Pediatric Overall Performance Category score of 3 or higher and increased by 1 from baseline.

Setting:

One hundred twenty-eight PICUs in 26 countries.

Patients:

Children with severe sepsis in the Sepsis PRevalence, OUtcomes, and Therapies study.

Interventions:

None.

Measurements and Main Results:

One hundred two (21%) of 493 patients had severe acute kidney injury. More than twice as many patients with severe acute kidney injury died or developed new moderate disability compared with those with no/mild acute kidney injury (64% vs 30%; p < 0.001). Severe acute kidney injury was independently associated with death or new moderate disability (adjusted odds ratio, 2.5; 95% CI, 1.5–4.2; p = 0.001) after adjustment for age, region, baseline disability, malignancy, invasive mechanical ventilation, albumin administration, and the pediatric logistic organ dysfunction score.

Conclusions:

In a multinational cohort of critically ill children with severe sepsis and high mortality rates, septic acute kidney injury is independently associated with further increased death or new disability.
Human Papillomavirus Type 16 L2 DNA Methylation in Exfoliated Cervical Cells From College-Age Women
Authors: Anderson Erin L. , Banister Carolyn E. , Kassler Susannah , Messersmith Amy , Pirisi Lucia , Creek Kim E. , Wyattt Michael D.
Published: August 2016

Objectives

The Carolina Women’s Care Study (CWCS) at the University of South Carolina followed 467 young women with the goal of identifying biomarkers of human papillomavirus (HPV) persistence. In this study, we analyzed the methylation of HPV16 DNA.

Methods

The aims of this study were to determine the methylation status of the HPV16 L2 gene in DNA isolated from exfoliated cervical cells collected longitudinally as part of the CWCS and to determine the prevalence of polymorphisms (single nucleotide polymorphisms [SNPs]) in folate metabolizing enzymes and DNA repair enzymes known to affect DNA methylation in blood-derived genomic DNA from CWCS participants. For methylation studies, DNA samples were bisulfite converted and amplified with the EpiTect Whole Bisulfitome kit. Polymerase chain reaction was performed for amplicons containing 5 CpG sites in L2. Pyrosequencing was carried out using EpigenDx and analyzed with PyroMark Software. Taqman genotyping assays were performed to determine selected SNP alleles in the CWCS cohort.

Results and Conclusions

Methylation data were obtained for 82 samples from 27 participants. Of these, 22 participants were positive for HPV16 for 3 or more visits (≥12 months). Methylation in L2 was detectable, but methylation levels varied and were not associated with HPV16 persistence. No linearity of methylation levels over time was observed in participants for whom longitudinal data could be analyzed. Analysis of 9 selected SNPs did not reveal an association with persistence. We conclude that at early stages of infection methylation of HPV16 L2 DNA in Pap test samples is not a predictive biomarker of HPV persistence.
Validation of Interstitial Fractional Volume Quantification by Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Porcine Skeletal Muscles
Authors: Hindel Stefan , Söhner Anika , Maaß Marc , Sauerwein Wolfgang , Baba Hideo Andreas , Kramer Martin , Lüdemann Lutz
Published: August 2016

Objectives

The aim of our study was to assess the accuracy of fractional interstitial volume determination in low perfused and low vascularized tissue by using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

Materials and Methods

The fractional interstitial volume (v
e) was determined in the medial thigh muscle of 12 female pigs by using a 3-dimensional gradient echo sequence with k-space sharing and administering gadolinium-based contrast agent (gadoterate meglumine). Analysis was performed using 3 pharmacokinetic models: the simple Tofts model (TM), the extended TM (ETM), and the 2-compartment exchange model (2CXM). We investigated the effect of varying acquisition durations (ADs) on the model parameter estimates of the 3 models and compared the v
e values with the results of histological examinations of muscle sections of the medial thigh muscle.

Results

Histological measurements yielded a median value (25%–75% quartile) of 4.8% (3.7%–6.2%) for v
e. The interstitial fractional volume determined by DCE-MRI was comparable to the histological results but varied strongly with AD for the TM and ETM. For the TM and the ETM, the results were virtually the same. Choosing arterial hematocrit to Hcta = 0.4, the lowest median v
e value determined by DCE-MRI was 5.2% (3.3%–6.1%) for the ETM at a 6-minute AD. The maximum v
e value determined with the ETM at a 15-minute AD was 7.7% (4.5%–9.0%). The variation with AD of median v
e values obtained with the 2CXM was much smaller: 6.2% (3.1%–9.2%) for the 6-minute AD and 6.3% (4.3%–9.8%) for the 15-minute AD. The best fit for the 2CXM was found at the 10-minute AD with v
e values of 6.6% (3.7%–8.2%). No significant correlation between the histological and any DCE-MRI modeling results was found. Considering the expected accuracy of histological measurements, the medians of the MR modeling results were in good agreement with the histological prediction. A parameter determination uncertainty was identified with the use of the TMs. This is due to underfitting and has a major effect even on the analysis of tissues with low vascularization and low perfusion, where the estimated v
e values depend on the AD. For the TM and ETM, the results best matched the histological measurements for an AD of 6 minutes.

Conclusions

Owing to more fitting parameters, the 2CXM yielded better fits and the median interstitium-to-plasma rate constant k
ep was less depending on the AD; however, the uncertainty expressed by the 25% to 75% quartile range was found to be larger. An AD of 10 minutes was needed for the 2CXM to achieve accuracy comparable to those of the TMs with shorter ADs.
Dose Optimization for Computed Tomography Localizer Radiographs for Low-Dose Lung Computed Tomography Examinations
Authors: Schmidt Bernhard T. , Hupfer Martin , Saltybaeva Natalia , Kolditz Daniel , Kalender Willi A.
Published: August 2016

Introduction

Recent studies have shown a substantial reduction of radiation dose from computed tomography (CT) scans down to 0.1 mSv for lung cancer screening and cardiac examinations, when applying optimization techniques. Hence, CT localizer radiographs (LRs) might now be considered a significant contributor to the total dose of the CT examination. We investigated in our study the potential for reducing dose of the LRs by adapting the patient-specific acquisition parameters of the LR.

Materials and Methods

Localizer radiographs covering the lungs were acquired on 2 clinical scanners (64 slices, conventional detector [CD]; 96 slices, fully integrated detector [ID]) for 3 semianthropomorphic phantoms, representing a slim, a normal, and an obese adult. Starting at 120-kV tube voltage and 250-mA current were reduced until the image quality of the LR, and thereby the accuracy of the automatic exposure control was compromised; this was defined as a deviation of measured attenuation values in the center of the LR of more than 5% from the reference values measured at the highest tube voltage and current. Subsequent Monte Carlo calculations on anthropomorphic phantoms were performed to calculate organ and effective dose values for the respective optimal settings. In addition, effective dose values normalized to CTDIvol for tube voltages ranging from 60 to 160 kV were determined for the different combinations of phantom sizes, sexes, and LR views to evaluate dose efficiency.

Results

For the CD scanner, the optimal LR settings depended strongly on phantom size. Higher tube voltage and current were necessary for the larger phantoms. The ID scanner showed uncompromised LR quality for all phantoms using the lowest possible tube voltage-tube current combination of 80 kV and 20 mA. Depending on patient size and LR direction, effective dose values for the optimal settings ranged from 6 to 53 μSv and 3 to 11 μSv for the CD and ID scanner, respectively. For the example of an anterior-posterior LR on a normal patient, using the optimal settings instead of the standard settings on the ID scanner reduced LR dose from 53 μSv (120 kV, 30 mA) to 10 μSv (80 kV, 20 mA). The simulations for the different tube voltages show that effective dose and CTDIvol behave similarly for different views and patient sizes. However, the tube voltage level itself impacts the relationship between CTDIvol and effective dose, by up to a factor of 2.

Discussion

Dose from LRs may contribute significantly to the total effective dose of low-dose CT examinations such as lung cancer screening. Optimal LR settings can reduce LR dose substantially, but adaptations have to consider scanner characteristics, detector technology, and patient size. Thus, for low-dose CT examinations, such as cardiac examinations and lung cancer screening, LR optimization may result in a significant dose reduction and thereby in a substantial reduction of total dose.
The Use of Acoustic Radiation Force Decorrelation-Weighted Pulse Inversion for Enhanced Ultrasound Contrast Imaging
Authors: Herbst Elizabeth B. , Unnikrishnan Sunil , Wang Shiying , Klibanov Alexander L. , Hossack John A. , Mauldin Frank William
Published: August 2016

Objectives

The use of ultrasound imaging for cancer diagnosis and screening can be enhanced with the use of molecularly targeted microbubbles. Nonlinear imaging strategies such as pulse inversion (PI) and “contrast pulse sequences” (CPS) can be used to differentiate microbubble signal, but often fail to suppress highly echogenic tissue interfaces. This failure results in false-positive detection and potential misdiagnosis. In this study, a novel acoustic radiation force (ARF)–based approach was developed for superior microbubble signal detection. The feasibility of this technique, termed ARF decorrelation-weighted PI (ADW-PI), was demonstrated in vivo using a subcutaneous mouse tumor model.

Materials and Methods

Tumors were implanted in the hindlimb of C57BL/6 mice by subcutaneous injection of MC38 cells. Lipid-shelled microbubbles were conjugated to anti-VEGFR2 antibody and administered via bolus injection. An image sequence using ARF pulses to generate microbubble motion was combined with PI imaging on a Verasonics Vantage programmable scanner. ADW-PI images were generated by combining PI images with interframe signal decorrelation data. For comparison, CPS images of the same mouse tumor were acquired using a Siemens Sequoia clinical scanner.

Results

Microbubble-bound regions in the tumor interior exhibited significantly higher signal decorrelation than static tissue (n = 9, P < 0.001). The application of ARF significantly increased microbubble signal decorrelation (n = 9, P < 0.01). Using these decorrelation measurements, ADW-PI imaging demonstrated significantly improved microbubble contrast-to-tissue ratio when compared with corresponding CPS or PI images (n = 9, P < 0.001). Contrast-to-tissue ratio improved with ADW-PI by approximately 3 dB compared with PI images and 2 dB compared with CPS images.

Conclusions

Acoustic radiation force can be used to generate adherent microbubble signal decorrelation without microbubble bursting. When combined with PI, measurements of the resulting microbubble signal decorrelation can be used to reconstruct images that exhibit superior suppression of highly echogenic tissue interfaces when compared with PI or CPS alone.
Scale-Free Exponents of Resting State are Biomarkers of Neuro-Typical and Atypical Brain Activity
Authors: Hanson S.J. , Mastrovito D. , Hanson C. , Ramsey J. , Glymour C.
Published: August 2016

Scale-free networks (SFN) arise from simple growth processes, which can encourage efficient, centralized and fault tolerant communication (1). Recently its been shown that stable network hub structure is governed by a phase transition at exponents (>2.0)causing a dramatic change in network structure including a loss of global connectivity, an increasing minimum dominating node set, and a shift towards increasing connectivity growth compared to node growth. Is this SFN shift identifiable in atypical brain activity? The Pareto Distribution (P(D)∼D∧-β) on the hub Degree (D) is a signature of scale-free networks. During resting-state, we assess Degree exponents across a large range of neurotypical and atypical subjects. We use graph complexity theory to provide a predictive theory of the brain network structure.Results.We show that neurotypical resting-state fMRI brain activity possess scale-free Pareto exponents(1.8 se .01)in a single individual scanned over 66 days as well as in 60 different individuals (1.8 se .02). We also show that 60 individuals with Autistic Spectrum Disorder, and 60 individuals with Schizophrenia have significantly higher (>2.0) scale-free exponents(2.4 se .03, 2.3 se .04), indicating more fractionated and less controllable dynamics in the brain networks revealed in resting state. Finally we show that the exponent values vary with phenotypic measures of atypical disease severity indicating that the global topology of the network itself can provide specific diagnostic biomarkers for atypical brain activity.
Modeling the Multiple Facets of Speciation-with-Gene-Flow Towards Inferring the Divergence History of Lake Whitefish Species Pairs (Coregonus Clupeaformis)
Authors: Rougeux Clément , Bernatchez Louis , Gagnaire Pierre-Alexandre
Published: August 2016

Parallel divergence patterns across replicated species pairs occurring in similar environmental contrasts may arise through distinct evolutionary scenarios. Deciphering whether such parallelism actually reflects repeated parallel divergence driven by divergent selection or a single divergence event with subsequent gene flow needs to be ascertained. Reconstructing historical gene flow is therefore of fundamental interest to understand how demography and selection jointly shaped genomic divergence during speciation. Here, we use an extended modeling framework to explore the multiple facets of speciation-with-gene-flow with demo-genetic divergence models that capture both temporal and genomic variation in effective population size and migration rate. We investigate the divergence history of five sympatric Lake Whitefish limnetic (dwarf) and benthic (normal) species pairs characterized by variable degrees of ecological divergence and reproductive isolation. Genome-wide SNPs were used to document the extent of genetic differentiation in each species pair, and 26 divergence models were fitted and compared to the unfolded joint allele frequency spectrum of each pair. We found evidence that a recent (circa 3000-4000 generations) asymmetrical secondary contact between expanding post-glacial populations has accompanied Whitefish diversification. Our results suggest that heterogeneous genomic differentiation patterns have emerged through the combined effects of linked selection generating variable rates of lineage sorting across the genome during geographical isolation, and heterogeneous introgression eroding divergence at different rates across the genome upon secondary contact. This study thus provides a new retrospective insight into the historical demographic and selective processes that shaped a continuum of divergence associated with ecological speciation.
Pangolin genomes and the evolution of mammalian scales and immunity
Authors: Choo Siew Woh , Rayko Mike , Tan Tze King , Hari Ranjeev , Komissarov Aleksey , Wee Wei Yee , Yurchenko Andrey A. , Kliver Sergey , Tamazian Gaik , Antunes Agostinho , Wilson Richard K. , Warren Wesley C. , Koepfli Klaus-Peter , Minx Patrick , Krasheninnikova Ksenia , Kotze Antoinette , Dalton Desire L. , Vermaak Elaine , Paterson Ian C. , Dobrynin Pavel , Sitam Frankie Thomas , Rovie-Ryan Jeffrine J. , Johnson Warren E. , Yusoff Aini Mohamed , Luo Shu-Jin , Karuppannan Kayal Vizi , Fang Gang , Zheng Deyou , Gerstein Mark B. , Lipovich Leonard , O'Brien Stephen J. , Wong Guat Jah
Published: August 2016

Pangolins, unique mammals with scales over most of their body, no teeth, poor vision, and an acute olfactory system, comprise the only placental order (Pholidota) without a whole-genome map. To investigate pangolin biology and evolution, we developed genome assemblies of the Malayan (Manis javanica) and Chinese (M. pentadactyla) pangolins. Strikingly, we found that interferon epsilon (IFNE), exclusively expressed in epithelial cells and important in skin and mucosal immunity, is pseudogenized in all African and Asian pangolin species that we examined, perhaps impacting resistance to infection. We propose that scale development was an innovation that provided protection against injuries or stress and reduced pangolin vulnerability to infection. Further evidence of specialized adaptations was evident from positively selected genes involving immunity-related pathways, inflammation, energy storage and metabolism, muscular and nervous systems, and scale/hair development. Olfactory receptor gene families are significantly expanded in pangolins, reflecting their well-developed olfaction system. This study provides insights into mammalian adaptation and functional diversification, new research tools and questions, and perhaps a new natural IFNE-deficient animal model for studying mammalian immunity.
Genomic variation within alpha satellite DNA influences centromere location on human chromosomes with metastable epialleles
Authors: Aldrup-MacDonald Megan E. , Kuo Molly E. , Sullivan Lori L. , Chew Kimberline , Sullivan Beth A.
Published: August 2016

Alpha satellite is a tandemly organized type of repetitive DNA that comprises 5% of the genome and is found at all human centromeres. A defined number of 171-bp monomers are organized into chromosome-specific higher-order repeats (HORs) that are reiterated thousands of times. At least half of all human chromosomes have two or more distinct HOR alpha satellite arrays within their centromere regions. We previously showed that the two alpha satellite arrays of Homo sapiens Chromosome 17 (HSA17), D17Z1 and D17Z1-B, behave as centromeric epialleles, that is, the centromere, defined by chromatin containing the centromeric histone variant CENPA and recruitment of other centromere proteins, can form at either D17Z1 or D17Z1-B. Some individuals in the human population are functional heterozygotes in that D17Z1 is the active centromere on one homolog and D17Z1-B is active on the other. In this study, we aimed to understand the molecular basis for how centromere location is determined on HSA17. Specifically, we focused on D17Z1 genomic variation as a driver of epiallele formation. We found that D17Z1 arrays that are predominantly composed of HOR size and sequence variants were functionally less competent. They either recruited decreased amounts of the centromere-specific histone variant CENPA and the HSA17 was mitotically unstable, or alternatively, the centromere was assembled at D17Z1-B and the HSA17 was stable. Our study demonstrates that genomic variation within highly repetitive, noncoding DNA of human centromere regions has a pronounced impact on genome stability and basic chromosomal function.
The use of social media for engaging stakeholders in sustainability reporting
Authors: Manetti Giacomo , Bellucci Marco
Published: August 2016

Purpose

– The purpose of this paper is to assess if online interaction through social media, particularly Facebook, Twitter, and YouTube, represents an effective stakeholder engagement mechanism in order to define the contents of social, environmental, or sustainability reporting (SESR).

Design/methodology/approach

– After examining 332 worldwide sustainability reports for the year 2013, drawn up according to the guidelines provided by the Global Reporting Initiative, the authors conducted a content analysis on the Twitter, Facebook, and YouTube pages of the organisations who rely on these types of social media. This was done in order to assess the scope of interaction between the organisation and its stakeholders.

Findings

– The authors found that a small number of organisations use social media to engage stakeholders as a means of defining the contents of SESR, and that the level of interaction is generally low. Rather than assuming a deliberative approach that is aimed at forging a democratic consensus on how to address specific corporate social responsibility or SESR issues, these types of interaction focus on gathering divergent socio-political views in an agonistic perspective.

Research limitations/implications

– Further research could complement this exploratory research with statistical analyses. It could focus on how comments/replies by users are used by organisations and examine the impacts of SESR on companies’ performances.

Originality/value

– The authors contribute to the literature on social accounting by understanding whether social media can be reliable instruments of stakeholder engagement and by examining the relevance of information that is voluntarily disclosed by corporations in SESR.
The role of identity and image in shaping management accounting change
Authors: Taylor Lynda C. , Scapens Robert W.
Published: August 2016

Purpose

– The purpose of this paper is to analyse the implementation of a new accounting system in the accounting department of a large retail company. The paper seeks to understand and explain how management accounting change can be shaped by the identity and image of particular groups in an organisation.

Design/methodology/approach

– This paper reports the findings of a longitudinal explanatory case study. An institutional framework was initially used to inform the research, but was subsequently extended using the concepts of identity and image.

Findings

– By changing existing accounting systems, the accountants “inside” the accounting department sought to challenge their current “negative” identity and image. However, the case shows that the new accounting system was not well received by accountants “outside” the accounting department. The case illustrates that the differing identity and image of the two groups of accountants were crucial factors underlying the different perceptions of the accounting change.

Originality/value

– The conceptual framework developed in this paper highlights the role which identity and image can play in shaping processes of change, and it enriches the understanding of the reasons for change, stability and resistance to change.
The influence of USD/CNY foreign exchange rate, RMB NEER and spatial effects on China’s foreign trade
Authors: Wang Hua , Zhu Junjun
Published: August 2016

Purpose

– The purpose of this paper is to analyze the influence of different forms of RMB foreign exchange rates on Chinese foreign trade.

Design/methodology/approach

– This paper constructed spatial panel model and Markov Chain Monte Carlo estimation method and collected the data of 25 countries’ (including China) quarterly macroeconomic data from first quarter of 1993 until third quarter of 2013 to conduct the data analysis.

Findings

– This paper finds that USD/CNY, which is widely used in trade settlement, is more significant in effecting Chinese export. Totally, 1 percent appreciation of CNY against USD will lead to 1.532 percent decline of Chinese export, while 1 percent appreciation of CNY NEER only 0.42 percent. What is more, 1 percent increases of the volatility of USD/CNY results in 0.579 percent decline of Chinese export. As policy suggestions, we should further reform the foreign exchange derivative market in China, and provide more currency derivatives, so that the ability of Chinese economy to deal with foreign exchange risk could be improved.

Research limitations/implications

– Effect of exchange rate on imports and exports relates to the future direction of China’s exchange rate policy. This paper claims that China should accelerate the construction of foreign exchange derivatives market, improving the ability to respond quickly to foreign currency risk.

Practical implications

– First, denominated exchange rate has more significant impact on the Chinese export trade to other countries than effective exchange rate. Second, the RMB exchange rate fluctuations also significantly affect the export trade. Third, China’s import and export trade have significant spatial effect.

Social implications

– This paper recommends the construction of the RMB currency futures market as soon as possible, providing a richer foreign exchange derivatives and other risk hedging instruments, thus to enhance the ability to respond to exchange rate risks.

Originality/value

– This paper uses spatial panel model with the refined data to study various factors on the import and export trade, and thus more comprehensive analysis on the impact of the exchange rate on the import and export trade with other major countries.
The dependence structure in volatility between Shanghai and Shenzhen stock market in China
Authors: Guo Mingyuan , Wang Xu
Published: August 2016

Purpose

– The purpose of this paper is to analyse the dependence structure in volatility between Shanghai and Shenzhen stock market in China based on high-frequency data.

Design/methodology/approach

– Using a multiplicative error model (hereinafter MEM) to describe the margins in volatility of China’s Shanghai and Shenzhen stock market, this study adopts static and time-varying copulas, respectively, estimated by maximum likelihood estimation method to describe the dependence structure in volatility between Shanghai and Shenzhen stock market in China.

Findings

– This paper has identified the asymmetrical dependence structure in financial market volatility more precisely. Gumbel copula could best fit the empirical distribution as it can capture the relatively high dependence degree in the upper tail part corresponding to the period of volatile price fluctuation in both static and dynamic view.

Originality/value

– Previous scholars mostly use GARCH model to describe the margins for price volatility. As MEM can efficiently characterize the volatility estimators, this paper uses MEM to model the margins for the market volatility directly based on high-frequency data, and proposes a proper distribution for the innovation in the marginal models. Then we could use copula-MEM other than copula-GARCH model to study on the dependence structure in volatility between Shanghai and Shenzhen stock market in China from a microstructural perspective.