bluuebunny/crossref_metadata_2025_split huggingface dataset:
Residual cyclooxygenase-1 activity and epinephrine reduce the antiplatelet effect of aspirin in patients with acute myocardial infarction
Authors: Moscardó Antonio , Fuset María Paz , Ruano Miguel , Santos María Teresa , Vallés Juana 
Published: February 2011

SummaryAspirin treatment is essential in patients with acute myocardial infarction (AMI) to block platelet thromboxane (TXA)2 synthesis. Epinephrine is known to enhance platelet reactivity induced by other agonists and to be elevated in patients with AMI due to stress. Our objective was to study the influence of epinephrine on platelet TXA2 synthesis in patients treated with aspirin for AMI at early onset (within 48 hours) and the potential biochemical mechanisms involved in the functional response. Washed platelets from 45 patients with AMI and 10 aspirin-free controls were stimulated with arachidonic acid (AA) or AA + epinephrine, and aggregation and TXA2 synthesis were evaluated. Full platelet aggregation was recorded in 8/45 patients (18%) with a partial TXA2 inhibition (86%) vs. the aspirin-free controls. Platelets from the remaining 37 patients did not aggregate to AA and had TXA2 inhibition >95%. However, when platelets were simultaneously stimulated with AA + epinephrine, in 25/37 patients a large intensity of aggregation (73%) was observed and a 5.5-fold increase in TXA2 synthesis, although this remained residual (<5% of aspirin-free controls). This residual-TXA2 was critical in the functional response, as demonstrated by the complete inhibition by TXA2 receptor blockade or additional aspirin in vitro. The phosphatidylinositol-3-kinase activity and the cytosolic calcium levels participated in this platelet response elicited by a receptor cooperation mechanism, while the Rho/p160ROCK pathway or the blockade of the ADP receptors (P2Y1, P2Y12) were without effect. Residual-cyclooxygenase –1 activity and epinephrine enhance TXA2-dependent platelet function, which may reduce the clinical benefit of aspirin in patients with AMI.
Ischaemic cardiovascular mortality in patients with non-valvular atrial fibrillation according to CHADS2 score
Authors: Kim Young Dae , Cha Myoung Jin , Kim Jinkwon , Lee Dong Hyun , Lee Hye Sun , Nam Chung Mo , Nam Hyo Suk , Heo Ji Hoe 
Published: February 2011

SummaryThe CHADS2 score predicts the risk of ischaemic stroke in patients with non-valvular atrial fibrillation (NVAF). Most components of the CHADS2 score are also risk factors of atherosclerosis, and clustering of these risk factors is associated with increased risk of cardiovascular disease, including ischaemic heart disease. The aim of this study was to investigate whether the CHADS2 score and CHA2DS2-VASc score are predictive of fatal ischaemic heart disease as well as fatal ischaemic stroke. Among 5,268 stroke patients admitted between August 1994 and December 2008, 770 stroke patients with NVAF were enroled in this study. The relationship between CHADS2 score or CHA2DS2-VASc score and the fatal ischaemic events was examined using a Cox regression model. During the follow-up period of 1156.0 ± 1205.0 days (median 729.5, in-terquartile range 179.0 – 1751.0), 321 patients died (41.7%). The CHADS2 score or CHA2DS2-VASc score was positively correlated with fatal ischaemic heart disease as well as with fatal ischaemic stroke. After adjustment for all potential confounders, the occurrence of fatal ischaemic heart disease was independently associated with CHADS2 score or CHA2DS2-VASc score, and previous history of ischaemic heart disease. The CHADS2 and CHA2DS2-VASc scores provide valuable information for identifying high-risk individuals for fatal ischaemic heart and brain diseases among stroke patients with NVAF.
Comparative assessment of drug-eluting balloons in an advanced porcine model of coronary restenosis
Authors: Byrne Robert , Lapointe Jean-Martin , Radke Peter , Bayer Gerd , Steigerwald Kristin , Wittchow Eric , Joner Michael 
Published: February 2011

SummaryThe advent of drug-eluting balloon (DEB) therapy has represented an important development in interventional cardiology. Nevertheless, pre-clinical data with this technology remain scant, and comparative studies have not previously been published. Bare metal stents were implanted in the coronary arteries of 15 pigs followed by balloon angioplasty. Animals were allocated to treatment with a 60-second inflation of one of four different balloon catheters: a conventional untreated plain angioplasty balloon (PBA, Biotronik AG), the Pantera Lux DEB (3.0 μg/mm2 paclitaxel; BTHC excipient, Biotronik AG), the Elutax DEB (2.0 μg/mm2 paclitaxel; no excipient; Aachen Resonance), or the SeQuent Please DEB (3.0 μg/mm2 paclitaxel; iopromide excipient: B. Braun). Twenty-eight days following balloon deployment, animals underwent repeat angiography for quantitative coronary angiography analysis and euthanasia for histopathologic assessment. By histology, the mean neointimal thickness was 0.44 ± 0.19 mm with PBA, 0.35 ± 0.13 mm with Pantera Lux, 0.61 ± 0.20 mm with Elutax, and 0.47 ± 0.21 mm with SeQuent Please DEB (p=0.02). In comparison with PBA, deployment of the Pantera Lux or the SeQuent Please DEB resulted in delayed healing characterised by significant increases in fibrin, neointimal cell vacuity and delayed re-endothelialisation. In conclusion, investigation of comparative DEB performance in a porcine model of advanced coronary restenosis reveals significant heterogeneity of neointimal suppression between the devices tested with numerically lowest values seen in the Pantera Lux group. On the other hand, evidence of delayed healing was observed in the most effective DEB groups.
Listing and Transplanting Adults With Congenital Heart Disease
Authors: Davies Ryan R. , Russo Mark J. , Yang Jonathan , Quaegebeur Jan M. , Mosca Ralph S. , Chen Jonathan M. 
Published: February 2011

Background—
An increasing number of patients with congenital heart disease (CHD) are reaching adulthood and may require heart transplantation. The survival of these patients after listing and transplantation has not been evaluated.

Methods and Results—

A total of 41 849 patients (aged >18 years) were listed for primary transplantation during 1995–2009. Patients with a history of CHD (n=1035; 2.5%) were compared with those with other causes (non-CHD group) (n=40 814; 97.5%); 26 055 (62.3%) reached transplantation and were subdivided into those with (reoperation group; n=10 484; 40.2%) and without (nonreoperation group; n=15 571; 59.8%) a previous sternotomy. Survival on the waiting list was similar between groups, but mechanical ventricular assistance was not associated with superior survival to transplantation among CHD patients. CHD patients were more likely to have body mass index <18.5 at transplantation (
P
<0.0001), were younger, and had fewer comorbidities. Early mortality among patients with CHD was high (reoperation, 18.9% versus 9.6%;
P
<0.0001; nonreoperation, 16.6% versus 6.3%;
P
<0.0001), but by 10 years, overall survival was equivalent (53.8% versus 53.6%). Analysis was limited by the lack of specific information regarding the CHD diagnosis in most patients.

Conclusions—
Adults with CHD have high 30-day mortality but better late survival after heart transplantation. Mechanical circulatory assistance does not improve waiting list survival in these patients. This may be due to a combination of highly complex reoperative surgery and often poor preoperative systemic health.
Simulations of Dissipative, Shore-Oblique Infragravity Waves
Authors: Henderson Stephen M. , Bowen A. J. 
Published: February 2011

AbstractA model of forced, dissipative shore-oblique shallow water waves predicts net cross-shore infragravity wave propagation, in qualitative agreement with field observations. Forcing applied near the shore generates edge waves, whose energy is mostly trapped shoreward of the edge wave turning point. Forcing applied sufficiently far seaward of the turning point generates only evanescent waves, whose energy decays almost exponentially with distance from regions of forcing. Weakly dissipative edge waves are nearly cross-shore standing, whereas strongly dissipative edge waves propagate obliquely across-shore. Groups of directionally spread incident waves can nonlinearly force evanescent bound waves, which propagate shoreward, lowering the sea level under large incident waves. Unlike the bound waves described by previous researchers, evanescent bound waves are not released when incident waves break and do not radiate far from the breakpoint. Regions of evanescent waves between the shoreface and shore-parallel sandbars are barriers to energy transport, which can decouple bar- and shore-trapped waves even when dissipation is weak.
Oceanic Teleconnections: Remote Response to Decadal Wind Forcing
Authors: Cessi Paola , Otheguy Pantxika 
Published: February 2011

Abstract
The transhemispheric and interbasin response to time-dependent wind forcing localized in the Northern Hemisphere of a single basin is examined using the reduced-gravity shallow-water equations in domains of simple geometry. On decadal timescales, the pressure on the eastern boundary fluctuates synchronously in both hemispheres and thus communicates a signal to latitudes distant from the forcing. The signal then penetrates into the interior through westward radiation of Rossby waves. Associated with the eastern boundary pressure fluctuation is a time-dependent mass flux across the equator that, in a single basin, is balanced by a storage of mass in the unforced hemisphere. Two oceanic basins connected by a reentrant channel at the high-latitude edge of the Southern Hemisphere are then considered. Again the forcing is confined to the Northern Hemisphere of one basin only. In this geometry the time-dependent mass flux across the equator of the forced basin is not entirely balanced within the same basin, but induces a mass flux into the unforced basin, while the mass heaving within the periodic channel is negligible. This process is illustrated by considering winds oscillating at a period on the same order as the Rossby wave transit time in high latitudes. The interhemispheric and interbasin teleconnection is achieved by a combination of long Rossby waves and large-scale, low-frequency gravity waves forced by the Rossby signal. These disturbances share no characteristics of Kelvin waves; that is, they are not boundary trapped.
Why Are There Rossby Wave Maxima in the Pacific at 10°S and 13°N?
Authors: Capotondi Antonietta , Alexander Michael A. , Deser Clara 
Published: February 2011

Abstract
Observations indicate the existence of two bands of maximum thermocline depth variability centered at ∼10°S and 13°N in the tropical Pacific Ocean. The analysis of a numerical integration performed with the National Center for Atmospheric Research ocean general circulation model (OGCM) forced with observed fluxes of momentum, heat, and freshwater over the period from 1958 to 1997 reveals that the tropical centers of thermocline variability at 10°S and 13°N are associated with first-mode baroclinic Rossby waves forced by anomalous Ekman pumping. In this study the factors that may be responsible for the Rossby wave maxima at 10°S and 13°N, including the amplitude and spatial coherency of the forcing at those latitudes, are systematically investigated. A simple Rossby wave model is used to interpret the OGCM variability and to help to discriminate between the different factors that may produce the tropical maxima. These results indicate that the dominant factor in producing the maximum variability at 10°S and 13°N is the zonal coherency of the Ekman pumping, a characteristic of the forcing that becomes increasingly more pronounced at low frequencies, maximizing at timescales in the decadal range. Local maxima in the amplitude of the forcing, while not explaining the origin of the centers of variability at 10°S and 13°N, appear to affect the sharpness of the variability maxima at low frequencies. Although the Rossby wave model gives an excellent fit to the OGCM, some discrepancies exist: the amplitude of the thermocline variance is generally underestimated by the simple model, and the variability along 13°N is westward intensified in the wave model but reaches a maximum in the central part of the basin in the OGCM. Short Rossby waves excited by small-scale Ekman pumping features, or the presence of higher-order Rossby wave modes may be responsible for the differences in the zonal variance distribution along 13°N.
Complications in Pediatric Deep Neck Space Abscesses
Authors: Baldassari Cristina M. , Howell Rebecca , Amorn Melissa , Budacki Ross , Choi Sukgi , Pena Maria 
Published: February 2011

ObjectivesTo determine the incidence and demographic profile of children who develop complications from deep neck space abscess.Study DesignCase series.SettingTertiary children’s hospital.Subjects and MethodsOne hundred thirty‐eight patients admitted for deep neck space abscesses between 1998 and 2008. Inclusion criteria were age younger than 18 years and computed tomography scan demonstrating an abscess in the retropharyngeal, parapharyngeal, or peritonsillar spaces. Children were diagnosed with abscess if purulence was encountered on operative incision and drainage.ResultsIn the first 5 years of the study, 45 children met the inclusion criteria, whereas in the latter 5 years, 93 children were treated for abscesses. There were no differences between these cohorts in terms of age (P =. 70), gender (P =. 08), abscess site (P =. 23), or rate of surgical intervention (P =. 83). The total major complication rate was 9.4% (n = 13) with mediastinitis being the most frequent (n = 9) complication. The number of complications between the first (n = 3) and second (n = 10) groups was not significantly different (P =. 55). The factors that predisposed patients to develop complications were younger age at presentation and retropharyngeal abscess location. Children with complications were more likely to have Staphylococcus aureus identified as the causative organism (P =. 007). Only 1 of 4 children with methicillin‐resistant S aureus had a complicated clinical course.ConclusionsDeep neck space abscesses continue to cause significant morbidity in children. Factors that predict complications include young age, retropharyngeal location, and S aureus. Providers must maintain a high index of suspicion to promptly diagnose and treat these complications.
Race as a Social Construct in Head and Neck Cancer Outcomes
Authors: Worsham Maria J. , Divine George , Kittles Rick A. 
Published: February 2011

ObjectiveThe authors examined ancestry informative markers (AIMs) to estimate the amount of population admixture and control for this heterogeneity for stage and survival in a primary head and neck squamous cell carcinoma (HNSCC) cohort.Study DesignHistorical cohort study.SettingIntegrated health care system.SubjectsThe cohort comprised 358 patients with HNSCC who self‐reported race as Caucasian American (CA), African American (AA), or other.MethodsDNA was interrogated for West African (WA) and European genetic background by genotyping AIMs. Associations of race (self‐report or WA ancestry) with stage and survival were analyzed using logistic regression and Cox regression modeling. A subgroup analysis for diagnosis (late vs early stage) and survival (time to death) and WA ancestry was performed for self‐reported AAs.ResultsThere were significant associations between stage and self‐reported race (P =. 04 [univariate]) and with cancer site (oropharynx: P =. 014; hypopharynx: P =. 026 [multivariate]). For prognosis, there were significant multivariate associations between stage (P =. 002), age (>65 years, P <. 001), and cancer site (hypopharynx: P <. 001; oral cavity: P =. 049), but self‐reported race was not associated with overall survival. Interestingly, there was no association with degree of WA ancestry and stage or survival. In the subgroup analysis of genetic ancestry among self‐reported AAs, cancer site remained an independent risk factor for stage (other site: P =. 026) and survival (oropharynx: P =. 036). Late stage persisted as an independent variable for poor survival (P =. 032).ConclusionsStratification within AAs by WA ancestry revealed no correlation with stage or survival, suggesting that HNSCC outcomes with race may be owing to social/behavior factors rather than biological differences.
Prophylactic Neck Dissection in Early Oral Tongue Squamous Cell Carcinoma 2.1 to 4.0 mm Depth
Authors: Lin Matthew J. , Guiney Anthony , Iseli Claire E. , Buchanan Malcolm , Iseli Tim A. 
Published: February 2011

ObjectiveRegional recurrence is common following surgery for T1/T2 oral tongue squamous cell carcinoma (SCC). Tumor depth >4.0 mm is commonly assigned as an indication for prophylactic neck dissection to improve regional control. Prophylactic neck dissection may detect extracapsular extension, a poor prognostic sign where adjuvant chemotherapy is indicated. The hypothesis in this study is that regional recurrence is a significant problem in 2.1‐ to 4.0‐mm‐depth tumors, and detection of extracapsular extension may be important in this group.Study DesignRetrospective chart review.SettingAustralian tertiary referral center.Subjects and MethodsReview of all patients with T1/T2 oral tongue SCC treated surgically between January 1991 and January 2009 (n = 81).ResultsTwenty‐nine prophylactic and 5 therapeutic neck dissections followed for a median 34 months (range, 4‐132 months). Tumor depths were 0 to 2.0 mm (n = 15), 2.1 to 4.0 mm (n = 18), 4.1 to 7.0 mm (n = 26), and >7.0 mm (n = 22). Tumors 2.1 to 4.0 mm depth had similar rates of occult nodes as 4.1 to 7.0 mm depth (25% vs 20%). Regional recurrence occurred in 31% overall, 44% in tumors 2.1 to 4.0 mm, and 27% in tumors 4.1 to 7.0 mm depth. Prophylactic neck dissection reduced regional recurrence (17% vs 43%,P=. 02). Patients with pathologically negative necks had lower rates of regional recurrence than those with occult nodes (9% vs 50%,P<. 01). Extracapsular extension increased regional recurrence (43% vs 7%,P=. 02), including 25% of dissected necks with tumor depth 2.1 to 4.0 mm.ConclusionsRegional recurrence is a significant problem in 2.1‐ to 4.0‐mm‐depth T1/T2 tongue tumors. Prophylactic neck dissection may improve regional control in patients with adequate primary resection margins and determine need for adjuvant therapies in 2.1‐ to 4.0‐mm‐depth tumors.
Otolaryngology Resident Selection
Authors: Bent John P. , Colley Patrick M. , Zahtz Gerald D. , Smith Richard V. , Parikh Sanjay R. , Schiff Bradley , Fried Marvin P. 
Published: February 2011

ObjectivesTo examine the relationship between National Residency Matching Program (NRMP) rank list position and future otolaryngology residency performance.Study DesignCohort study.MethodsEight consecutive residency classes (starting 2001‐2008; 4 residents/y) were reviewed. Three hundred and thirty‐three applicants (40.6 applicants/y) were interviewed, and 316 (94.9%) were ranked. Residents matching with our program were divided 3 different ways: into quarters, thirds, and halves, based on their rank order. Correlation coefficients were obtained to compare resident rank number and rank group (quarter, third, half) to faculty evaluation, coresident evaluation, and in‐service score. Chi‐square tests were conducted comparing rank group to chief resident selection and annual teaching award.ResultsResident NRMP rank number was not significantly correlated with faculty evaluation, coresident evaluation, or in‐service exam score (−0.21 < r < 0.05; P >. 28). There was also no significant correlation between resident quarter, third, or half rank group and faculty evaluation; coresident evaluation; or in‐service exam score (−0.29 < r < 0.10; P >. 13). Chi‐square analysis found no relationship between resident rank group and chief resident (P >. 35) or teaching award (P >. 13) selection.ConclusionsApplicant rank number and rank group did not correlate with performance of this otolaryngology residency cohort as assessed by faculty evaluation, coresident evaluation, in‐service exam score, or selection for chief resident or the annual teaching award. Resident selection committees should consider reallocating manpower hours from creating rank order to recruiting applicants and selecting interview candidates.
Endothelium-dependent vasodilatation in migraine patients
Authors: Perko Denis , Pretnar-Oblak Janja , Sabovic Miso , Zvan Bojana , Zaletel Marjan 
Published: February 2011

Background: Endothelial dysfunction could be involved in the pathophysiology of migraine. The results obtained from a few studies on endothelial dysfunction in migraine are controversial. We investigated brachial flow-mediated dilatation (FMD), which reflects systemic endothelial dysfunction, in migraine patients without comorbidities. By employing strict inclusion criteria we avoided the possible changes to FMD from confounding factors. Methods. Forty migraine patients without comorbidities (20 with and 20 without aura) and 20 healthy subjects were included. FMD of brachial arteries and carotid intima-media thickness were measured by using standard procedures. Results. We did not find any difference in FMD between migraine patients and healthy subjects ( p = .96). Also, no differences were found among healthy subjects, migraine patients with aura and without aura ( p = .99). Conclusion. Our study showed that systemic endothelial function is not impaired in migraine patients without comorbidities, neither in those with or without aura. Considering these findings, the investigation of cerebral endothelial function would be useful in a further investigation of the role of endothelial (dys)function in migraine pathophysiology.
Using Bogie-Mounted Sensors to Understand the Dynamics of Third Rail Current Collection Systems
Authors: Stewart E , Weston P , Hillmansen S , Roberts C 
Published: February 2011

Electric railways collect power from the infrastructure via various current collection systems. For high-voltage AC- and DC-powered railways, this is usually achieved using overhead electrification equipment and a train-borne pantograph. The dynamics of such systems are well understood, and the systems are able to be operated under a range of conditions and speeds. Lower-voltage DC-powered railways (<1500 V) use a current collecting shoe as part of a shoegear system and track side electrification infrastructure in the form of a conductor rail. The dynamics of such systems are equally as complex as those of overhead systems. This is due to the interaction between the conductor rail and the track system, coupled with the dynamics of the conductor shoe assembly, which are mechanically linked with the bogie and axle systems. The systems also collect high currents (<2000 A), and therefore maintaining an effective electrical contact is essential. The interface between the conductor shoe and conductor rail is regulated through standards and guidelines. However, there are numerous engineering challenges in the effective management of the whole system that have yet to be addressed. The mechanical design of the system must balance the requirements of good fatigue life with appropriate impact strength. Other issues such as removal of contaminants from the conductor rail surface and shoe wear also have an impact on the design. This article presents some experimental results from a bogie-mounted instrumentation system designed to monitor a typical example of a shoegear assembly operated on the UK railway system. The results indicate that the shoegear broadly performs in accordance with the design guidelines. Several points of loss of contact were observed, and it is shown that the contact force between the conductor shoe and rail can be estimated. The mean force was found to vary with third rail height, but a wide distribution of forces is found at any one height because of hysteresis in the shoegear. Large, but short-term, forces and torques occur because of third rail irregularities and ramps.