bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adverse Remodeling of the Electrophysiological Response to Ischemia–Reperfusion in Human Heart Failure Is Associated With Remodeling of Metabolic Gene Expression
Authors: Ng Fu Siong , Holzem Katherine M. , Koppel Aaron C. , Janks Deborah , Gordon Fabiana , Wit Andrew L. , Peters Nicholas S. , Efimov Igor R. 
Published: August 2014

Background—
Ventricular arrhythmias occur more frequently in heart failure during episodes of ischemia–reperfusion although the mechanisms underlying this in humans are unclear. We assessed, in explanted human hearts, the remodeled electrophysiological response to acute ischemia–reperfusion in heart failure and its potential causes, including the remodeling of metabolic gene expression.

Methods and Results—

We optically mapped coronary-perfused left ventricular wedge preparations from 6 human end-stage failing hearts (F) and 6 donor hearts rejected for transplantation (D). Preparations were subjected to 30 minutes of global ischemia, followed by 30 minutes of reperfusion. Failing hearts had exaggerated electrophysiological responses to ischemia–reperfusion, with greater action potential duration shortening (
P
<0.001 at 8-minute ischemia;
P
=0.001 at 12-minute ischemia) and greater conduction slowing during ischemia, delayed recovery of electric excitability after reperfusion (F, 4.8±1.8 versus D, 1.0±0 minutes;
P
<0.05), and incomplete restoration of action potential duration and conduction velocity early after reperfusion. Expression of 46 metabolic genes was probed using custom-designed TaqMan arrays, using extracted RNA from 15 failing and 9 donor hearts. Ten genes important in cardiac metabolism were downregulated in heart failure, with
SLC27A4
and
KCNJ11
significantly downregulated at a false discovery rate of 0%.

Conclusions—
We demonstrate, for the first time in human hearts, that the electrophysiological response to ischemia–reperfusion in heart failure is accelerated during ischemia with slower recovery after reperfusion. This can enhance spatial conduction and repolarization gradients across the ischemic border and increase arrhythmia susceptibility. This adverse response was associated with downregulation of expression of cardiac metabolic genes.
Examination of the Treatment Selection Process in a Multicenter Observational Study
Authors: Anstrom Kevin J. , Brennan J. Matthew , Eisenstein Eric L. , Federspiel Jerome J , Dai David , Peterson Eric D. , Douglas Pamela S. 
Published: August 2014

Background—
Many multicenter clinical trials use permuted-block randomization to create balanced treatment allocations within clinical centers. Unlike randomized trials, observational studies do not control treatment allocation, and statistical models are used to adjust for measured confounders. For many observational data analyses, the variability in the treatment selection process within clinical centers is ignored. Furthermore, there is no consensus on the best approach for dealing with variability in the treatment selection process across clinical centers.

Methods and Results—
Individuals aged ≥65 years receiving either drug-eluting stents or bare metal stents were included. A cohort of 262 700 patients from 650 CathPCI Registry sites was followed up for a median of 15 months. Propensity score models were estimated to describe the process used to select drug-eluting stents across the study population. Substantial variability in the use of drug-eluting stents at the clinical center level was observed—even after accounting for differences in patient and clinical center characteristics. By refitting and matching propensity scores within clinical centers, a balanced cohort on treatment allocation and prognostic factors was obtained. This approach generated an estimated hazard ratio that was qualitatively similar to standard regression models and other propensity score approaches.

Conclusions—
Substantial variability in treatment selection existed between clinical centers. Matching recalibrated propensity scores within clinical centers has the potential to reduce a source of bias in multicenter observational studies. This methodology cannot eliminate all potential for biases; however, it removes the potential bias from site-level factors.
Plasma Magnesium and Risk of Ischemic Stroke Among Women
Authors: Adebamowo Sally N. , Jiménez Monik C. , Chiuve Stephanie E. , Spiegelman Donna , Willett Walter C. , Rexrode Kathryn M. 
Published: August 2014

Background and Purpose—
Lower plasma magnesium levels may be associated with higher blood pressure and endothelial dysfunction, but sparse prospective data are available for stroke.

Methods—
Among 32 826 participants in the Nurses’ Health Study who provided blood samples in 1989 to 1990, incident ischemic strokes were identified and confirmed by medical records through 2006. We conducted a nested case–control analysis of 459 cases, matched 1:1 to controls on age, race/ethnicity, smoking status, date of blood draw, fasting status, menopausal status, and hormone use. We used conditional logistic regression models to estimate the multivariable adjusted association of plasma magnesium and the risk of ischemic stroke and ischemic stroke subtypes.

Results—

Median magnesium levels did not differ between ischemic stroke cases and controls (median, 0.86 mmol/L for both;
P
=0.14). Conditional on matching factors, women in the lowest magnesium quintile had a relative risk of 1.34 (95% confidence interval, 0.86–2.10;
P
trend=0.13) for total ischemic stroke compared with women in the highest quintile. Additional adjustment for risk factors and confounders did not substantially alter the risk estimates for total ischemic stroke. Women with magnesium levels <0.82 mmol/L had significantly greater risk of total ischemic stroke (multivariable relative risk, 1.57; 95% confidence interval, 1.09–2.27;
P
=0.01) and thrombotic stroke (multivariable relative risk, 1.66; 95% confidence interval, 1.03–2.65;
P
=0.03) compared with women with magnesium levels ≥0.82 mmol/L. No significant effect modification was observed by age, body mass index, hypertension, or diabetes mellitus.

Conclusions—
Lower plasma magnesium levels may contribute to higher risk of ischemic stroke among women.
Effects of Surgical Revascularization on Cerebral Oxygen Metabolism in Patients With Moyamoya Disease
Authors: Kuroda Satoshi , Kashiwazaki Daina , Hirata Kenji , Shiga Tohru , Houkin Kiyohiro , Tamaki Nagara 
Published: August 2014

Background and Purpose—
This prospective study was aimed to evaluate the effects of surgical revascularization on cerebral oxygen metabolism in moyamoya disease.

Methods—

This study included totally 69 hemispheres of 42 patients who underwent superficial temporal artery to middle cerebral artery anastomosis and indirect bypass for moyamoya disease between 2000 and 2011. There were 12 children and 30 adults. MRI and
15
O-gas positron emission tomography were performed before and 3 to 4 months after surgery. Hemodynamic and metabolic parameters were precisely quantified and statistically analyzed.

Results—

Preoperative positron emission tomographic scans revealed that cerebral blood flow was decreased, cerebral blood volume was increased, and cerebral metabolic rate for oxygen was decreased in both pediatric and adult patients. Cerebral metabolic rate for oxygen reduction was observed in ≈80% of pediatric (16/21; 76%) and adult hemispheres (38/48; 79%). Surgical revascularization resolved hemodynamic compromise in all operated hemispheres. Cerebral metabolic rate for oxygen significantly improved in pediatric patients without parenchymal lesions (n=8), but not those with parenchymal lesions (n=8). Multivariate analysis revealed that cerebral metabolic rate for oxygen significantly improved in younger adult patients without parenchymal lesions (
P
=0.0264; odds ratio, 0.88; 95% confidence interval, 0.79–0.99).

Conclusions—
Cerebral oxygen metabolism is significantly depressed in ≈80% of the involved hemispheres of moyamoya disease and improves in pediatric and younger adult patients without parenchymal lesions after bypass surgery. Cerebral oxygen metabolism may be reversibly depressed in response to cerebral ischemia in them although the underlying mechanisms are still unclear.
Energetics of Multidecadal Atlantic Ocean Variability
Authors: Dijkstra Henk A. , Saenz Juan A. , McC. Hogg Andrew 
Published: August 2014

Abstract
Oscillatory behavior of the Atlantic meridional overturning circulation (MOC) is thought to underlie Atlantic multidecadal climate variability. While the energy sources and sinks driving the mean MOC have received intense scrutiny over the last decade, the governing energetics of the modes of variability of the MOC have not been addressed to the same degree. This paper examines the energy conversion processes associated with this variability in an idealized North Atlantic Ocean model. In this model, the multidecadal variability arises through an instability associated with a so-called thermal Rossby mode, which involves westward propagation of temperature anomalies. Applying the available potential energy (APE) framework from stratified turbulence to the idealized ocean model simulations, the authors study the multidecadal variability from an energetics viewpoint. The analysis explains how the propagation of the temperature anomalies leads to changes in APE, which are subsequently converted into the kinetic energy changes associated with variations in the MOC. Thus, changes in the rate of generation of APE by surface buoyancy forcing provide the kinetic energy to sustain the multidecadal mode of variability.
Acoustic reflectors are visible in the right heart during radiofrequency ablation of varicose veins
Authors: Sounderajah V , Moore HM , Thapar A , Lane TRA , Fox K , Franklin IJ , Davies AH 
Published: August 2014

Objective Cerebrovascular events have been noted after foam sclerotherapy for varicose veins. One hypothesis is migration of microemboli to the brain through a cardiac septal defect. The aim of this study was to identify whether acoustic reflectors are found in the right side of the heart during radiofrequency ablation of varicose veins, as neurological events are not reported during these procedures. Methods Transthoracic echocardiography was performed during local anaesthetic radiofrequency ablation (VNUS ClosureFast) of the great saphenous vein in 14 patients. An apical view was captured at the start of the procedure, during each cycle of heating and at 1 min post-treatment. Patients were monitored for 1 h. Video loops were read by an independent cardiologist. The presence of acoustic reflectors was classified as: 0 = absent, 1 = occasional, 2 = stream, 3 = complete opacification. Results Loops were of diagnostic quality in 11/14 (79%) patients. After the second cycle of heating, acoustic reflectors moving through the right heart were seen in 5/11 (45%) patients. These were classified as grade 1 in four patients and grade 2 in one patient. No acoustic reflectors were seen in the left heart. No neurological symptoms were reported. Conclusion Acoustic reflectors in the right heart are a common finding during radiofrequency ablation of varicose veins. Considering the prevalence of cardiac septal defects (17%), more neurological events would be expected if these particles were indeed responsible for these events. Further work is required to elicit the mechanisms underlying neurological complications following sclerotherapy.
What is the incidence of patients with palliative care needs presenting to the Emergency Department? A critical review
Authors: Wong Joanne , Gott Merryn , Frey Rosemary , Jull Andrew 
Published: August 2014

Background: Given the context of ageing populations globally, there are a growing number of patients with chronic conditions, some of whom are in the final stages of their disease trajectory, presenting to Emergency Departments. Aim: The aim was to estimate the incidence of patients with palliative care needs presenting to the department. Methods: Three databases (MEDLINE, CINAHL and Embase) were systematically searched up to August 2012. The reference lists of included articles were searched as well as Google and Google Scholar. Only studies in English were included. Two reviewers independently reviewed studies at the abstract and full-body stages. A critical review using systematic methods was undertaken as statistical analysis could not be done because of a lack of information. Results: Only 10 of 1427 identified records met the inclusion criteria. Different definitions of palliative care were evident. One article provided an incidence density for patients with non-small cell lung cancer, and we calculated the mean presentations to be 52.5 per 100 person-months. Two articles focussed on patients known to palliative care services; we estimated that 2.5 in 1000 Emergency Department visits were made by these patients. The review demonstrated that the studies were so different it was not possible to compare the data. Conclusion: There is an absence of evidence regarding the incidence of patients with palliative care needs presenting to the Emergency Department. Further research needs to be undertaken in this area to ensure both clinicians and policymakers have sufficient information for service provision.
Low-dose CT for patients with clinically suspected acute appendicitis: optimal strength of sinogram affirmed iterative reconstruction for image quality and diagnostic performance
Authors: Kim Seung Ho , Yoon Jung-Hee , Lee Jang Hee , Lim Yun-Jung , Kim Ok Hwa , Ryu Ji Hwa , Son Jung-Hee 
Published: August 2014

Background As there is increased concern over the radiation exposure particularly in adolescents and young adults, computed tomography (CT) dose reduction is needed in the diagnosis of acute appendicitis. Purpose To evaluate the optimal strength of sinogram affirmed iterative reconstruction (SAFIRE) to obtain the best image quality on a 30-mAs applied low-dose CT (LDCT30mAs) and to compare the diagnostic performances of the LDCT30mAs with different SAFIRE strengths with that of the 100-mAs applied LDCT (LDCT100mAs) for the diagnosis of acute appendicitis. Material and Methods A total of 102 consecutive patients (47 men, 55 women; mean age, 41.2 years; range, 15–82 years) with right lower quadrant pain underwent abdominal-pelvic CT, consisting of arterial phase LDCT100mAs and portal venous phase LDCT30mAs under a fixed 120 kV. LDCT30mAs images were reconstructed separately with five strength levels (S1–S5). Two blinded radiologists recorded scores for the subjective image quality of the LDCT30mAs dataset (S0–S5) and confidence scores for the diagnosis of acute appendicitis on each dataset and LDCT100mAs. CT image noise was measured for each set. Results The study population consisted of 58 patients with confirmed appendicitis and 44 without appendicitis. There was no significant difference in diagnostic performance between LDCT100mAs and LDCT30mAs with any strength for both readers (AUC for reader 1, LDCT30mAs with S0–S5 = 0.97, LDCT100mAs = 0.93, P = 0.0936; for reader 2, LDCT30mAs with S0–S5 = 0.96, LDCT100mAs = 0.97, P = 0.128). The measured noise decreased as the strength increased from S0 to S5 (mean, 20.8 > 17.7 > 15.6 > 13.5 > 11.5 > 9.5, P < 0.0001). However, overall subjective image quality on S3 was better than the other strengths for both readers (S0 < S1 < S2 < S3 > S4 > S5, P < 0.0001). Conclusion Although measured noise declined as SAFIRE strength increased, S3 seems optimal for the best subjective image quality on LDCT30mAs. The diagnostic performance of LDCT30mAs with any strength is comparable to that of LDCT100mAs for the diagnosis of acute appendicitis.
Intake and Macronutrient Content of Human Milk Given to Extremely Preterm Infants
Authors: Stoltz Sjöström Elisabeth , Öhlund Inger , Tornevi Andreas , Domellöf Magnus 
Published: August 2014

Background: Human milk (HM) is the preferred basis of nutrition for infants, including those born prematurely. Information on HM macronutrient content is necessary to optimize nutritional support of preterm infants. Objectives: This study aimed to describe the types and amounts of enteral feeds given to Swedish extremely preterm infants during hospitalization and to investigate the energy and macronutrient contents in HM given to these infants. Methods: A population-based study of Swedish extremely preterm infants (n = 586) born before 27 gestational weeks was conducted. Data on ingested volumes of different milk during hospitalization and analyses of macronutrient content in HM samples were obtained from hospital records. Nutritional content of HM was determined by mid-infrared spectrophotometry analysis. Results: During the first 4 weeks of life, 99% of the infants were exclusively fed HM, and at 4 weeks of life, 70% of the infants received only mother’s own milk (MOM). Nutritional content in 821 MOM samples was analyzed. Protein content in MOM decreased significantly from 2.2 to 1.2 g/100 mL during the first 112 postpartum days, whereas fat and energy content were highly variable within and between MOM samples. In addition, 354 samples of donor milk were analyzed. Content of protein, fat, and energy in pooled donor milk (n = 129) was lower compared to single donor milk. Conclusion: Swedish extremely preterm infants receive MOM to a large extent during hospitalization. Protein, carbohydrates, and energy in MOM changed significantly with time. Weekly analyses of MOM during the first month of lactation would allow more individualized nutritional support for these vulnerable infants.
Comparison of Continuous Nerve Block Versus Patient-Controlled Analgesia for Postoperative Pain and Outcome After Talar and Calcaneal Fractures
Authors: Luiten Willem E. , Schepers Tim , Luitse Jan S. , Goslings J. Carel , Hermanides Jeroen , Stevens Markus F. , Hollmann Markus W. , van Samkar Gan 
Published: August 2014

Background: Talar and calcaneal fractures and their treatment can cause severe postoperative pain. We hypothesized that a continuous peripheral nerve block (CPNB) would reduce pain scores more effectively than systemic analgesics, improve recovery, and lead to reduced length of stay (LOS). Methods: Over a 3-year period patients undergoing open reduction and internal fixation (ORIF) of a talar or calcaneal fracture were retrospectively analyzed. Patients received a CPNB catheter preoperatively or intravenous patient-controlled analgesia (PCA) postoperatively. Primary endpoint was Numerical Rating Scale (NRS) scores on postoperative day 1. Secondary endpoints were NRS scores up to day 3, opioid requirement, analgesia-related side effects, intraoperative blood loss, infection, and LOS. Eighty-seven patients were analyzed; 70 with calcaneal fracture, 21 with talar fracture, 4 with both. In all, 40 patients received CPNB, 47 patients PCA. Results: Median NRS scores on day 1 were 1.0 (IQR 3) in the CPNB group and 2.0 (IQR 3) in the PCA group ( ns). Median LOS for patients with CPNB was 5 days (IQR3) and PCA 4 days (IQR 2 ns). Blood loss and incidence of local infections were comparable in both groups. Opioid requirement was significantly increased in the PCA group ( P < .01). Conclusion: Significant advantages or disadvantages were not seen in either group. However, the PCA group required about 30-fold more opioids compared to the CPNB group on day 1, although that did not lead to an increased number of side effects. Level of Evidence: Level III, retrospective comparative series.
The Prognostic Value of the Hawkins Sign and Diagnostic Value of MRI After Talar Neck Fractures
Authors: Chen Hao , Liu Wenzhou , Deng Lianfu , Song Weidong 
Published: August 2014

Background: The early diagnosis of avascular necrosis of the talus (AVN) and prediction of ankle function for talar fractures are important. The Hawkins sign, as a radiographic predictor, could exclude the possibility of developing ischemic bone necrosis after talar neck fractures, but its relationship with ankle function remains unclear. The purpose of this study was to illustrate the prognostic effect of the Hawkins sign on ankle function after talar neck fractures and to study the value of early MRI in detecting the AVN changes after talus fractures. Methods: Cases of talar neck fractures between November 2008 and November 2013 were evaluated. The occurrences of the Hawkins sign and AVN were studied. X-ray imaging was performed at multiple time points from the 4th to the 12th week after the fractures, and MRI examinations were used in the Hawkins sign negative group, with the time span ranging from 1.5 to 12 months. AOFAS scores of the Hawkins sign positive and negative groups were compared during the follow-up. Forty-four cases (48 feet) were evaluated. Results: The occurrence of positive Hawkins sign was 50%, 30%, and 33.3%, the incidence of AVN was 0%, 10%, and 50%, respectively, in type I, type II, and type III and IV talus fractures, respectively. The AOFAS scores showed no statistically significant difference between Hawkins sign positive group and negative group in type I and II fractures. The Hawkins sign positive group had better AOFAS scores than the negative group in type III and IV fractures. However, there was no statistically significant difference between Hawkins sign positive and negative groups when AVN cases were excluded in type III and IV fractures. Conclusion: The Hawkins sign was a reliable predictor excluding the possibility of AVN. It did not have predictive value on the ankle function in low-energy fractures and may predict better ankle function in high-energy fractures. MRI can diagnose AVN during an earlier period, and we believe Hawkins sign negative patients should undergo MRI examinations 12 weeks after the fractures, especially in high-energy traumatic cases. Level of Evidence: Level III, comparative case series.