bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two novel Jknull alleles derived from 222C>A in Exon 5 and 896G>A in Exon 9 of the JK gene
Authors: Liu Hsueng‐Mei , Lin Jeong‐Shi , Chen Pei‐Shan , Lyou Jau‐Yi , Chen Ying‐Ju , Tzeng Cheng‐Hwai 
Published: January 2009

BACKGROUND: Polynesian Jknull is well known for its mutation as Intron 5 g>a at the 3′ splice acceptor site. After sequencing analysis, however, it was noticed that only three of eight samples with the Jknull phenotype carried typical homozygous Polynesian Jknull mutation. Five others were noted to be unreported heterozygous Polynesian Jknull mutation. An investigation was then conducted to characterize the underlying mechanism leading to this particular Jknull genotype.STUDY DESIGN AND METHODS: Genomic DNA covering 5′‐untranslated region exons and intervening introns of the JK gene was amplified by polymerase chain reaction, and the fragments were directly sequenced. The sequencing results were compared with those published in literature and related biologic Web sites.RESULTS: In all five samples with a heterozygous Polynesian Jknull mutation, additional mutations were identified. Two samples carried missense mutations: 222C>A (Asn74Lys) in Exon 5 and 499A>G (Met167Val) in Exon 7. Three others had missense mutation 896G>A (Gly299Glu) in Exon 9. These substituted amino acids were located either near or at transmembrane domains, respectively. In addition, two polymorphic nucleotides at positions −103 (a>g) and −119(c>a) from the 3′ end of Intron 1 were also Polynesian mutation–related.CONCLUSIONS: In contrast to the typical homozygous Polynesian Jknull mutation, two novel heterozygous Jknull alleles were noted to be associated with the Jknull phenotype. One carried missense mutation 222C>A in Exon 5, and the other had 896G>A missense mutation in Exon 9. These findings may have implications in designing a molecular screening assay for people with the Jknull phenotype.
High‐Water Marks: High Risk Appetites? Convex Compensation, Long Horizons, and Portfolio Choice
Authors: PANAGEAS STAVROS , WESTERFIELD MARK M. 
Published: January 2009

ABSTRACTWe study the portfolio choice of hedge fund managers who are compensated by high‐water mark contracts. We find that even risk‐neutral managers do not place unbounded weights on risky assets, despite option‐like contracts. Instead, they place a constant fraction of funds in a mean‐variance efficient portfolio and the rest in the riskless asset, acting as would constant relative risk aversion (CRRA) investors. This result is a direct consequence of the in(de)finite horizon of the contract. We show that the risk‐seeking incentives of option‐like contracts rely on combining finite horizons and convex compensation schemes rather than on convexity alone.
Share Repurchases and Pay‐Performance Sensitivity of Employee Compensation Contracts
Authors: BABENKO ILONA 
Published: January 2009

ABSTRACTI show that share repurchases increase pay‐performance sensitivity of employee compensation and lead to greater employee effort and higher stock prices. Consistent with the model, I find that after repurchases, employees and managers receive fewer stock option and equity grants, and that the market reacts favorably to repurchase announcements when employees have many unvested stock options. Managers are more likely to initiate share repurchases when employees hold a large stake in the firm. Moreover, since employees are forced to bear more risk in firms that repurchase shares, they exercise their stock options earlier and receive higher compensation.
Financing Innovation and Growth: Cash Flow, External Equity, and the 1990s R&D Boom
Authors: BROWN JAMES R. , FAZZARI STEVEN M. , PETERSEN BRUCE C. 
Published: January 2009

ABSTRACTThe financing of R&D provides a potentially important channel to link finance and economic growth, but there is no direct evidence that financial effects are large enough to impact aggregate R&D. U.S. firms finance R&D from volatile sources: cash flow and stock issues. We estimate dynamic R&D models for high‐tech firms and find significant effects of cash flow and external equity for young, but not mature, firms. The financial coefficients for young firms are large enough that finance supply shifts can explain most of the dramatic 1990s R&D boom, which implies a significant connection between finance, innovation, and growth.
CEO Compensation and Board Structure
Authors: CHHAOCHHARIA VIDHI , GRINSTEIN YANIV 
Published: January 2009

ABSTRACTIn response to corporate scandals in 2001 and 2002, major U.S. stock exchanges issued new board requirements to enhance board oversight. We find a significant decrease in CEO compensation for firms that were more affected by these requirements, compared with firms that were less affected, taking into account unobservable firm effects, time‐varying industry effects, size, and performance. The decrease in compensation is particularly pronounced in the subset of affected firms with no outside blockholder on the board and in affected firms with low concentration of institutional investors. Our results suggest that the new board requirements affected CEO compensation decisions.
Do Entrenched Managers Pay Their Workers More?
Authors: CRONQVIST HENRIK , HEYMAN FREDRIK , NILSSON MATTIAS , SVALERYD HELENA , VLACHOS JONAS 
Published: January 2009

ABSTRACTAnalyzing a panel that matches public firms with worker‐level data, we find that managerial entrenchment affects workers' pay. CEOs with more control pay their workers more, but financial incentives through cash flow rights ownership mitigate such behavior. Entrenched CEOs pay more to employees closer to them in the corporate hierarchy, geographically closer to the headquarters, and associated with conflict‐inclined unions. The evidence is consistent with entrenched CEOs paying more to enjoy private benefits such as lower effort wage bargaining and improved social relations with employees. Our results show that managerial ownership and corporate governance can play an important role for employee compensation.
Market Sidedness: Insights into Motives for Trade Initiation
Authors: SARKAR ASANI , SCHWARTZ ROBERT A. 
Published: January 2009

ABSTRACTWe infer motives for trade initiation from market sidedness. We define trading as more two‐sided (one‐sided) if the correlation between the number of buyer‐ and seller‐initiated trades increases (decreases), and assess changes in sidedness (relative to a control sample) around events that identify trade initiators. Consistent with asymmetric information, trading is more one‐sided before merger news. Consistent with belief heterogeneity, trading is more two‐sided before earnings and macro announcements with greater dispersion in analyst forecasts, and after news with larger announcement surprises. We examine the codeterminacy of sidedness, bid‐ask spread, volatility, number of trades, and order imbalance.
Private Benefits of Control, Ownership, and the Cross‐listing Decision
Authors: DOIDGE CRAIG , KAROLYI G. ANDREW , LINS KARL V. , MILLER DARIUS P. , STULZ RENÉ M. 
Published: January 2009

ABSTRACTThis paper investigates how a foreign firm's decision to cross‐list on a U.S. stock exchange is related to the consumption of private benefits of control by its controlling shareholders. Theory has proposed that when private benefits are high, controlling shareholders are less likely to choose to cross‐list in the United States because of constraints on the consumption of private benefits resulting from such listings. Using several proxies for private benefits related to the control and cash flow ownership rights of controlling shareholders, we find support for this hypothesis with a sample of more than 4,000 firms from 31 countries.
Right Ventricular Outflow Tract Septal Pacing: Long‐Term Follow‐Up of Ventricular Lead Performance
Authors: MEDI CAROLINE , MOND HARRY G. 
Published: January 2009

Background: The detrimental effects of right ventricular apical pacing on left ventricular function has driven interest in selective site pacing, predominantly on the right ventricular outflow tract (RVOT) septum. There is currently no information on long‐term ventricular lead electrical performance from this site.
Methods: A total of 100 patients with ventricular lead placement on the RVOT septum undergoing pacemaker implantation for bradycardia indications were analyzed retrospectively. Lead positioning was confirmed with the use of fluoroscopy. Long‐term (1 year) follow‐up was obtained in 92 patients. Information on stimulation threshold, R‐wave sensing, lead impedance, and lead complications were collected.
Results: Lead performance at the RVOT septal position was stable in the long term. Ventricular electrical parameters were acceptable with stable long‐term stimulation thresholds, sensing, and impedance for all lead types. One‐year results demonstrated mean stimulation threshold of 0.71 ± 0.25 V, mean R wave of 12.4 ± 6.05 mV, and mean impedance values of 520 ± 127 Ω. There were no cases of high pacing thresholds or inadequate sensing.
Conclusions: This study confirms satisfactory long‐term performance with leads placed on the RVOT septum, comparable to traditional pacing sites. It is now time to undertake studies to examine the long‐term hemodynamic effects of RVOT septal pacing.
Reversal of Atrial Remodeling after Cardioversion of Persistent Atrial Fibrillation Measured with Magnetocardiography
Authors: LEHTO MIKA , JURKKO RAIJA , PARIKKA HANNU , MÄNTYNEN VILLE , VÄÄNÄNEN HEIKKI , MONTONEN JUHA , VOIPIO‐PULKKI LIISA‐MARIA , TOIVONEN LAURI , LAINE MIKA 
Published: January 2009

Background: Atrial fibrillation (AF) causes electrical, functional, and structural changes in the atria. We examined electrophysiologic remodeling caused by AF and its reversal noninvasively by applying a new atrial signal analysis based on magnetocardiography (MCG).
Methods: In 26 patients with persistent AF, MCG, signal‐averaged electrocardiography (SAECG), and echocardiography were performed immediately after electrical cardioversion (CV), and repeated after 1 month in 15 patients who remained in sinus rhythm (SR). Twenty‐four matched subjects without history of AF served as controls. P‐wave duration (Pd) and dispersion (standard deviation of Pd values in individual channels) and root mean square amplitudes of the P wave over the last 40 ms portions (RMS40) were determined.
Results: In MCG Pd was longer (122.8 ± 18.2 ms vs 101.5 ± 14.6 ms, P < 0.01) and RMS40 was higher (60.4 ± 28.2 vs 46.9 ± 19.1 fT) in AF patients immediately after CV as compared to the controls. In SAECG Pd dispersion was increased in AF patients. Mitral A‐wave velocity and left atrial (LA) contraction were decreased and LA diameter was increased (all P < 0.01). After 1 month, Pd in MCG still remained longer and LA diameter greater (both P < 0.05), while RMS40 in MCG, Pd dispersion in SAECG, mitral A‐wave velocity, and LA contraction were recovered.
Conclusions: Magnetocardiographically detected atrial electrophysiologic alterations in persistent AF diminish rapidly although incompletely during maintained SR after CV. This might be related to the known early high and late lower, but still existent tendency to AF relapses.
Insights into the Effects of Contraction Dyssynchrony on Global Left Ventricular Mechano‐Energetic Function
Authors: JOHNSON LAUREN , SIMON MARC A. , PINSKY MICHAEL R. , SHROFF SANJEEV G. 
Published: January 2009

Background: The effects of dyssynchrony on global left ventricular (LV) mechanics have been well documented; however, its impact on LV energetics has received less attention.
Objective: To assess the effects of LV contraction dyssynchrony on global LV mechano‐energetic function in a pacing‐induced acute model of dyssynchrony.
Methods: Using blood‐perfused isolated rabbit heart preparations (n = 11), LV pressure, coronary flow, and arteriovenous oxygen content difference were recorded for isovolumic contractions under right atrial (RA) pacing (control) and simultaneous RA and right ventricular outflow tract (RVOT) pacing (dyssynchrony). LV mechanical function was quantified by the end‐systolic pressure‐volume relationship (ESPVR). Myocardial oxygen consumption‐pressure‐volume area (MVO2‐PVA) relationship quantified LV energetic function. Internal PVA for MVO2 RVOT was calculated based on the MVO2‐PVA relationship for RA pacing. Thus, lost PVA (internal PVA–PVARVOT) represents the mechanical energy not observable at the global level.
Results: Compared to RA pacing, RVOT pacing depressed LV mechanics as indicated by a rightward shift of ESPVR (i.e., increase in Vd from 0.58 ± 0.10 to 0.67 ± 0.10 mL, P < 0.05). Despite depressed mechanics, RVOT pacing was associated with greater MVO2 such that the MVO2‐PVA relationship intercept was markedly increased from 0.025 ± 0.003 to 0.029 ± 0.003 mL•O2/beat/100gLV (P < 0.05). Excess MVO2 (i.e., MVO2 RVOT– MVO2 RA) significantly correlated with lost PVA (R2= 0.54, P < 0.001).
Conclusion: A potential mechanism explaining the observed increase in MVO2 with dyssynchrony may be that the measured PVA at the global level underestimates the internal PVA at the cellular level, which is likely to be the true determinant of MVO2.
Implantable cardioverter defibrillator in maintenance hemodialysis patients with ventricular tachyarrhythmias: A single‐center experience
Authors: ITO Itaru , KONO Koichi , SHINBO Goro , TADOKORO Kazuyoshi , ABE Chikara , TAKEMURA Naoki , IEMURA Tomomi , MATSUHASHI Noritaka , NAKANO Nobuyuki , OTA Satoshi , ISHIMITSU Toshihiko , MATSUOKA Hiroaki 
Published: January 2009

AbstractPatients with hemodialysis (HD) are at risk of death due to cardiac arrhythmias, worsening congestive heart failure (CHF), and noncardiac causes. This study reviews our experience with the use of implantable cardioverter defibrillators (ICDs) in patients with ventricular tachycardia who are under maintenance HD. We retrospectively reviewed 71 consecutive patients who underwent an ICD implantation in our hospital. There were 11 patients under maintenance HD and 60 patients without HD. The group of patients with HD (HD group) was compared with the patients without HD (control group). The mean follow‐up period was 30±9 vs. 39±4 months in the HD group vs. the control group, respectively. Among these patients, 6 in the HD group and 26 in the control group received appropriate ICD therapies. There was no difference in appropriate ICD therapy, time to the first therapy, and electrical storm between the 2 groups. In the HD group, 1 patient underwent surgical removal of the ICD system due to infective endocarditis. There were 5 deaths in the HD group (4 from CHF) and 8 deaths in the control group (4 from CHF). There were no sudden cardiac deaths or arrhythmic deaths in both groups of patients during the follow‐up period. However, the overall death rate was significantly higher in the HD group (P<0.01). In HD patients, ICD therapy prevented arrhythmic death, but their rate of nonarrhythmic adverse outcomes was high. This risk‐benefit association should be considered before implantation of the device.
A pilot study of genetic polymorphisms and hemodialysis vascular access thrombosis
Authors: BROPHY Donald F. , BUKAVECKAS Bonny L. , FERREIRA‐GONZALEZ Andrea , ARCHER Kellie J. , MARTIN Erika J. , GEHR Todd W.B. 
Published: January 2009

AbstractVascular access thrombosis (VAT) remains a significant problem worldwide. This study determined the association between VAT and 7 candidate gene polymorphisms (factor V Leiden 1691G>A, factor II 20210G>A, methylenetetrahydrofolate reductase 677C>T, angiotensin converting enzyme 287 base pair (bp) insertion/deletion, transforming growth factor‐β1 869T>C and 915G>C, NOS3 −786T>C and intron 4 27 bp tandem repeat, and endotoxin receptor CD14 −159C>T). This was a retrospective case‐control pilot study conducted in 101 hemodialysis patients at a large tertiary‐care, University health‐science center. Sixty cases that experienced frequent VAT and 41 controls that had not experienced VAT in at least 3 years were evaluated for demographics and genotyping. These data were summarized, and univariable and multivariable regression models were constructed. Univariate VAT predictors included the NOS3 420 bp allele (P=0.03) and the presence of a central venous dialysis catheter (P<0.01). Aspirin use was protective against VAT (P=0.02). In the multivariate analysis, the dialysis access type remained a significant predictor of thrombosis (P<0.01), while aspirin use retained its protective status (P=0.01). Statin use was associated with the cases (P=0.02); however, the NOS3 420 bp allele failed to improve the model. These data confirm that central venous dialysis catheter access is associated with thrombosis, while aspirin use appears protective. The NOS3 420 bp allele may have an association with thrombosis; however, further epidemiologic data evaluating large dialysis registries are needed to confirm our observation.
The anticoagulant activity of enoxaparin sodium during on‐line hemodiafiltration and conventional hemodialysis
Authors: SOMBOLOS Kostas I. , FRAGIA Theodora K. , GIONANLIS Lazaros C. , VENETI Panagiota E. , BAMICHAS Gerasimos I. , FRAGIDIS Stelios K. , GEORGOULIS Ioannis E. , NATSE Taïsir A. 
Published: January 2009

AbstractTo study and compare the anticoagulant activity of enoxaparin sodium during on‐line hemodiafiltration (OL‐HDF) and conventional hemodialysis (C‐HD). Enoxaparin was administered as an anticoagulant to 21 hemodialysis patients at the beginning of a single 4‐hour OL‐HDF session as an intravenous bolus dose of 80 mg/kg. On‐line hemodiafiltration was performed using a high‐flux polyester polymer alloy dialyzer and a total of 18 L replacement fluid (session A). One week later, the study was repeated in the same patients during a single 4‐hour session of C‐HD using a low‐flux polysulfone dialyzer (session B). Blood samples for the measurement of Hb, blood urea and nitrogen (BUN), activated partial thromboplastin time (APTT), and anti‐Xa levels were taken before each study session and 5‐minute postdialysis. In 13 more patients, the same study was performed during OL‐HDF using a high‐flux polysulfone dialyzer (session C). No differences were found between sessions A, B, and C when predialysis values for Hb, BUN, APTT, and anti‐Xa were compared. The mean postdialysis APTT and anti‐Xa values were 32.5±3.8 seconds and 0.19±0.11 IU/mL, respectively, in session A, 39.0±5.0 seconds and 0.71±0.17 IU/mL in session B, and 33.8±3.1 seconds and 0.35±17 IU/mL in session C (A vs. B, P<0.0001, for both parameters, A vs. C, P<0.003 for anti‐XA, and B vs. C, P<0.005, for both parameters). The anticoagulant activity of enoxaparin sodium is decreased significantly during a 4‐hour OL‐HDF session compared with to a similar session of C‐HD. The degree of the reduction seems to depend on the dialyzer's membrane.
Triage of women with equivocal or low‐grade cervical cytology results: a meta‐analysis of the HPV test positivity rate
Authors: Arbyn Marc , Martin‐Hirsch Pierre , Buntinx Frank , Van Ranst Marc , Paraskevaidis Evangelos , Dillner Joakim 
Published: January 2009

Introduction
Methods
Results
Discussion
Conclusion

AbstractConsistent evidence underlines the utility of human papillomavirus (HPV) DNA testing in the management of women with equivocal cervical cytological abnormalities, but not in case of low‐grade lesions. We performed a meta‐analysis including studies where the high‐risk probe of the Hybrid Capture‐II is used to triage these two cytological categories. The triage test‐positivity rate reflects the colposcopy referral workload.Data were pooled on the HPV test positivity rate in women with atypical squamous cells of undetermined significance (ASCUS/ASC‐US) or low‐grade squamous intraepithelial lesions (LSIL), derived from different cytological classification systems. The meta‐analysis was restricted to studies, published between 1991 and 2007. A random‐effect model was applied for meta‐analytical pooling and the influence of covariates on the HPV positivity rate was analyzed by meta‐regression. The variation by age was assessed within individual studies since age strata were not defined uniformly. On an average, 43% (95% CI: 40–46%) of women with ASCUS/ASC‐US were high‐risk HPV positive (range 23–74%). In women with LSIL, the pooled positivity rate was 76% (95% CI: 71–81%; range 55–89%). In spite of considerable inter‐study heterogeneity, the difference in HPV positivity between the two triage groups was large and highly significant: 32% (95% CI: 27–38%). HPV rates dropped tremendously as age and cutoffs of test positivity increased. Other factors (cytological classification system, country, continent, collection method and year of publication) had no statistically significant impact, except in LSIL triage where HPV positivity was significantly lower in European compared to American studies. Women with LSIL, especially younger women, have high HPV positivity rates suggesting limited utility of reflex HPV triaging these cases. Research is needed to identify more specific methods to triage women with low‐grade squamous cervical lesions.
The role of caveolae and caveolin 1 in calcium handling in pacing and contraction of mouse intestine
Authors: Daniel Edwin E. , Eteraf Tahereh , Sommer Bettina , Cho Woo Jung , Elyazbi Ahmed 
Published: January 2009

AbstractIn mouse intestine, caveolae and caveolin‐1 (Cav‐1) are present in smooth muscle (responsible for executing contractions) and in interstitial cells of Cajal (ICC; responsible for pacing contractions). We found that a number of calcium handling/dependent molecules are associated with caveolae, including L‐type Ca2+channels, Na+‐Ca2+exchanger type 1 (NCX1), plasma membrane Ca2+pumps and neural nitric oxide synthase (nNOS), and that caveolae are close to the peripheral endo‐sarcoplasmic reticulum (ER‐SR). Also we found that this assemblage may account for recycling of calcium from caveolar domains to SR through L‐type Ca+channels to sustain pacing and contractions. Here we test this hypothesis further comparing pacing and contractions under various conditions in longitudinal muscle of Cav‐1 knockout mice (lacking caveolae) and in their genetic controls. We used a procedure in which pacing frequencies (indicative of functioning of ICC) and contraction amplitudes (indicative of functioning of smooth muscle) were studied in calcium‐free media with 100 mM ethylene glycol tetra‐acetic acid (EGTA). The absence of caveolae in ICC inhibited the ability of ICC to maintain frequencies of contraction in the calcium‐free medium by reducing recycling of calcium from caveolar plasma membrane to SR when the calcium stores were initially full. This recycling to ICC involved primarily L‐type Ca2+channels;i.e.pacing frequencies were enhanced by opening and inhibited by closing these channels. However, when these stores were depleted by block of the sarco/endoplasmic reticulum Ca2+‐ATPase (SERCA) pump or calcium release was activated by carbachol, the absence of Cav‐1 or caveolae had little or no effect. The absence of caveolae had little impact on contraction amplitudes, indicative of recycling of calcium to SR in smooth muscle. However, the absence of caveolae slowed the rate of loss of calcium from SR under some conditions in both ICC and smooth muscle, which may reflect the loss of proximity to store operated Ca channels. We found evidence that these channels were associated with Cav‐1. These changes were all consistent with the hypothesis that a reduction of the extracellular calcium associated with caveolae in ICC of the myenteric plexus, the state of L‐type Ca2+channels or an increase in the distance between caveolae and SR affected calcium handling.