bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased Dispersion of Ventricular Repolarization During Head‐Up Tilt Test Late After Orthotopic Heart Transplantation in Humans
Authors: LEE TSUNG‐MING , CHOU NAI‐KUAN , TSAI CHANG‐HER , KO WEN‐JE , TSAI PI‐RU , WANG SHOEI‐SHEN , CHU SHU‐HSUN
Published: July 2003

LEE, T.‐M., et al.: Increased Dispersion of Ventricular Repolarization During Head‐Up Tilt Test Late After Orthotopic Heart Transplantation in Humans. Sympathetic reinnervation after heart transplantation may be regionally heterogeneous. It remains undetermined if such heterogeneous reinnervation will result in increased ventricular repolarization dispersion. To determine the changes of ventricular repolarization after transplantation, a 15‐minute, 80‐degree head‐up tilt test was prospectively performed with isoproterenol provocation in 30 patients who were studied within 5 months after transplantation (early group) and 30 patients who were studied ≥12 months (late group). Holter monitor was initiated to evaluate heart rate variability, which was a surrogate of cardiac reinnervation. JT dispersion was defined as the difference between maximal and minimal JT interval measurements occurring among any of the 12 leads on a standard electrocardiogram. No subject had fewer than nine measurable leads. Compared with patients in the early group, the patients in the late group had higher low frequency activity, indicating partial sympathetic reinnervation. Analysis of the electrocardiogram showed that there were significant differences in the corrected JT dispersion in the late group compared with the early group and controls (74 ± 18 vs 56 ± 15 and 55 ± 14 ms, both P <0.05) during isoproterenol infusion. Head‐up tilt test is a useful tool to unmask the increased dispersion of ventricular repolarization, particularly during states of isoproterenol infusion. Early after cardiac transplantation, neither postural changes nor isoproterenol infusion caused a significant increase of corrected JT dispersion. Late after transplantation, heterogeneous sympathetic reinnervation may result in increased corrected JT dispersion. However, whether increased dispersion of ventricular repolarization is related to cardiac death late after operation warrants further investigation in a large and long‐term trial.
Arrhythmic Risk Stratification After Myocardial Infarction Using Ambulatory Electrocardiography Signal Averaging
Authors: ROCHE FRÉDÉRIC , DACOSTA ANTOINE , KARNIB IBRAHIM , TRIOMPHE GÉRALDINE , ROCHE CHRISTIAN , ISAAZ KARL , GEYSSANT ANDRÉ , BARTHÉLÉMY JEAN‐CLAUDE
Published: July 2003

ROCHE, F., et al.: Arrhythmic Risk Stratification After Myocardial Infarction Using Ambulatory Electrocardiography Signal Averaging. Ambulatory ECG had been proposed to examine the amplified high resolution signal‐averaged electrocardiogram (SAECG). Clinical investigations are required to confirm the predictive value of such a high resolution technique in arrhythmic risk stratification. The prognostic value of ambulatory Holter SAECG was evaluated in 108 postinfarction patients for the purpose of predicting the occurrence of serious arrhythmic (SARR) events (sudden cardiac death [SCD], VT, or VF) in comparison with classical real‐time SAECG. During the 42 ± 8 months of follow‐up, the sudden cardiac death mortality was 4.6% (five deaths), six (5.6%) patients had VT, and one (0.9%) VF. QRSd was found to be the most predictive parameter using ROC curves analysis for SAAR+ outcome (W = 0.833 and W = 0.803 for 25–250 Hz and 40–250 Hz filters, respectively) followed by RMS (W = 0.766 and W = 0.721) and LAS (W = 0.759, W = 0.709) (all P < 0.01). Abnormal Holter SAECG for 25 and 40‐Hz LP filter were significant predictors of SARR+ by log‐rank test (P < 0.01, P < 0.05, respectively). This study confirms that valuable prognostic information can be obtained from the ambulatory high resolution ECG technique and that Holter SAECG may predict arrhythmic risk in a postinfarction population.
Brugada‐Like Electrocardiographic Pattern Induced by Fever
Authors: SAURA DANIEL , GARCÍA‐ALBEROLA ARCADI , CARRILLO PILAR , PASCUAL DOMINGO , MARTÍNEZ‐SÁNCHEZ JUAN , VALDÉS MARIANO
Published: July 2003

SAURA, D., et al.: Brugada‐Like Electrocardiographic Pattern Induced by Fever. The Brugada syndrome is characterized by a peculiar ST‐segment elevation in the right precordial leads and the propensity to develop ventricular arrhythmias. Mutations in a cardiac sodium channel gene have been linked to this syndrome and some experimental data suggest that the dysfunction of the mutated channel can be temperature sensitive. This report describes a patient in whom a typical Brugada ECG pattern developed in relation to fever but could not be reproduced at normal temperature on administration of flecainide. This case suggests that in some patients a Brugada‐like ECG may only manifest during a febrile state.
Pacemaker Contact Sensitivity: Case Report and Review of the Literature
Authors: DÉRY JEAN‐PIERRE , GILBERT MARCEL , O'HARA GILLES , CHAMPAGNE JEAN , DESAULNIERS DENIS , CARTIER PAUL , PHILIPPON FRANÇOIS
Published: July 2003

DÉRY, J.‐P., et al.: Pacemaker Contact Sensitivity: Case Report and Review of the Literature. Pacemaker contact sensitivity is a rare condition. Less than 25 reports of pacemaker skin reaction have been described over the past 30 years. This report describes one patient who developed contact dermatitis after implantation of two subsequent pacemakers. The diagnosis was made with skin patch tests that were positive to polyurethane 75D and polysulfone beige, two of the pacemaker and connector components. Review of the literature and general guidelines for the management of this unusual condition is depicted in this report.
Evaluation of Myocardial Ischemia in Kawasaki Disease Using an Isointegral Map on Magnetocardiogram
Authors: SHIONO JUNKO , HORIGOME HITOSHI , MATSUI AKIRA , TERADA YASUSHI , WATANABE SHIGEYUKI , MIYASHITA TSUYOSHI , TSUKADA KEIJI
Published: July 2003

SHIONO, J., et al.: Evaluation of Myocardial Ischemia in Kawasaki Disease Using an Isointegral Map on Magnetocardiogram. The authors have recently reported on the usefulness of the isointegral mapping technique using magnetocardiography (MCG) for the diagnosis of adult ischemic heart disease. This study evaluated myocardial ischemia in patients with Kawasaki disease (KD). The ischemia has been considered difficult to diagnose with a standard ECG. The study included 32 patients (age 3 ± 22 years, mean 12.9 ± 4.1 years, ± SD) with a history of KD and 21 age‐matched healthy children. Coronary arterial lesions were present in 13 patients of the KD group, MCG was carried out at rest with a multichannel superconducting quantum interference device (SQUID) system. The integral value was computed for each channel and isointegral maps were constructed during depolarization and repolarization processes. In all subjects of the control group, the integral value of repolarization was higher than that of depolarization and the isointegral map of these two processes showed similar patterns. However, the integral value of repolarization in four cases with KD (one with a history of myocardial infarction, two with a stenotic lesion in the left coronary artery, one with an aneurysmal and stenotic lesion in the right coronary artery) was lower than that of depolarization, and abnormal patterns were evident in the isointegral map. All but the case with myocardial infarction showed only mild abnormalities or almost normal on the ECG. Although sensitivity of the method for detection of myocardial ischemia was not fully assessed because of the small number of cases with significant coronary arterial stenosis, noninvasive isointegral mapping technique using the MCG could be useful for evaluation of myocardial ischemia in patients with KD.
Multiple Pulse Generator Malfunctions with a Dual Chamber Pacemaker
Authors: LIPCHENCA IGOR , BARLEV DAVID , LURIA DAVID , GRANIT CHAVA , ROTSHTEIN ZEEV , ELDAR MICHAEL , GLIKSON MICHAEL
Published: July 2003

LIPCHENCA, I., et al.: Multiple Pulse Generator Malfunctions with a Dual Chamber Pacemaker. The aim of this study was to evaluate the dual chamber uni/bipolar pacemaker Minidual 50, manufactured by Sorin Biomedica. Between 1995 and 1998, 66 Minidual 50 models were implanted at the Heart Institute. During the follow‐up period of 33 ± 12.8 months (range 0–50 months), total function loss in seven (10.6%) units and false threshold measurement of sensing and pacing in three (4.5 %) patients were observed. Average time from implantation to malfunction was 37 months (range 28–42). Malfunction was unrelated to battery status and could not be predicted by any measures obtained during the pacemaker follow‐up period. Kaplan Meyer survival curve predicted a 70% 4‐year malfunction‐free survival of that pacemaker model. Given this high rate of total malfunction and the unpredictable nature of its occurrence, the authors recommend the replacement of all remaining Minidual 50 units at risk, at least in dependent patients.
Localization of the Ventricular Insertion Site of Concealed Left‐Sided Accessory Pathways Using Ventricular Pace Mapping
Authors: YAMABE HIROSHIGE , SHIMASAKI YUKIO , HONDA OSAMU , KIMURA YOSHIHIRO , HOKAMURA YOUICHI
Published: July 2003

YAMABE, H., et al.: Localization of the Ventricular Insertion Site of Concealed Left‐Sided Accessory Pathways Using Ventricular Pace Mapping. The aim of the present study was to localize the ventricular insertion site of concealed accessory pathway (APs) by using the ventricular pace mapping and examined if the analysis of the timing of retrograde atrial electrogram recorded at the ventricular side of the mitral annulus is useful in identifying the ventricular insertion site of the AP. In 39 patients with concealed left‐sided APs, ventricular pacing was delivered along the mitral annulus at a cycle length of 500 ms while measuring the conduction interval from the pacing stimulus to the earliest retrograde atrial electrogram recorded in the coronary sinus (St‐A). The ventricular insertion site of the AP was localized by identifying the shortest St‐A. Also the interval between the onsets of QRS and atrial electrograms (QRS‐A) and presence of continuous electrical activity (CEA) between the ventricular and atrial electrograms were evaluated at each mapping site during atrioventricular reciprocating tachycardia. Initial radiofrequency energy application to the site with the shortest St‐A (46 ± 15 ms) eliminated the AP conduction in all patients, suggesting the accurate localization of the ventricular insertion site by ventricular pace mapping. The QRS‐A and the percentage of the presence of CEA at the shortest St‐A site were 79 ± 19 ms and 64%, respectively. However, the earliest retrograde atrial activation site did not coincide with the shortest St‐A site in 19 of 39 patients, suggesting an oblique course of AP. Thus, in these 19 patients, there was a significant difference in St‐A (47 ± 16 vs 59 ± 15 ms, P < 0.0001), QRS‐A (83 ± 13 vs 72 ± 12 ms, P < 0.0001) and the presence of CEA (32 vs 74%, P < 0.01) between the shortest St‐A site and the earliest retrograde atrial activation site, respectively. These indicate that the earliest retrograde atrial activation is not necessarily indicative of the ventricular insertion site of AP. However, ventricular pace mapping was considered to be useful for identifying and ablating the ventricular insertion site of AP, irrespective of the course of AP.
Broadening the Perspective: Treating the Whole Patient
Authors: Krämer Günter
Published: July 2003

Summary:  Seizures are not the only obstacles that individuals with epilepsy must overcome. Treatment of epilepsy must take into consideration that patients with epilepsy often face some form of depression, such as peri‐ictal depression, ictal depression, interictal depression, or postictal depression, as well as an elevated risk of suicide. Elderly patients, in particular, require special consideration, since aging affects pharmacokinetics and pharmacodynamics; women of childbearing age also require additional counseling. Treatment strategies that focus only on seizure reduction are inadequate and unsuccessful in up to one half of all patients with epilepsy. Epilepsy requires broad treatment strategies that address the needs of the whole patient. Age, genetic factors, gender, diet, use of alcohol and nicotine, comorbidities, and polypharmacy all are important factors to consider in determining a successful epilepsy treatment strategy. Epilepsy affects many aspects of psychosocial function, and optimal outcomes require that the needs of the whole patient be adequately addressed.
A high‐titer, high‐thermal‐amplitude autoanti‐B associated with acrocyanosis but no obvious hemolytic anemia
Authors: Arndt Patricia A. , Do Jennifer B. , Garratty George , Kuriyan Mercy A. , Strair Roger K. , Baranwal Akhil
Published: July 2003

BACKGROUND: ABO autoantibodies are rare. Most reported examples have been antibodies with 4°C titers not greater than 256 in patients without apparent hemolytic anemia. Most high‐titer, high‐thermal‐amplitude, complement‐activating cold agglutinins are associated with hemolytic anemia.

STUDY DESIGN AND METHODS: A 52‐year‐old man presented with acrocyanosis and mild small‐vessel brain disease, but no evidence of obvious hemolytic anemia. Regular plasmapheresis treatment was helpful in relieving the clinical symptoms associated with acrocyanosis. Serologic methods were used to study the patient's RBCs and sera.

RESULTS: The patient's RBCs were strongly reactive with anti‐C3 and anti‐IgM and weakly reactive with anti‐IgA. The patient's serum contained a high‐titer, high‐thermal‐amplitude, IgMκ autoanti‐B, capable of activating complement in vitro.

CONCLUSION: A patient with a powerful ABO autoantibody is described. This patient had acrocyanosis but did not appear to have an obvious hemolytic anemia. This case is a good example of the lack of correlation between in vitro serologic tests and in vivo reactions in individual patients.
Circulating RBC volume, measured with biotinylated RBCs, is superior to the Hct to document the hematologic effects of delayed versus immediate umbilical cord clamping in preterm neonates
Authors: Strauss Ronald G. , Mock Donald M. , Johnson Karen , Mock Nell I. , Cress Gretchen , Knosp Laura , Lobas Lori , Schmidt Robert L.
Published: July 2003

BACKGROUND: One problem assessing the hematologic physiology of preterm infants after delivery and/or the efficacy and toxicity of therapeutic interventions affecting RBC measurements is the inability of blood Hct values to accurately reflect circulating RBC volume—owing to changes in plasma volume that influence Hct (i.e., a fall in plasma volume concentrates RBCs to increase Hct; a rise in plasma volume dilutes RBCs to decrease Hct).

STUDY DESIGN AND METHODS: As part of a randomized, clinical trial testing the hypothesis that delayed clamping of the umbilical cord at delivery expands neonatal circulating RBC volume, blood Hct was compared to circulating RBC volume results measured directly with autologous, biotinylated RBCs or estimated mathematically with neonatal body weight and Hct values in neonates after immediate or delayed (60 sec) cord clamping.

RESULTS: Circulating RBC volume measured directly with biotinylated RBCs significantly increased (p=0.04) in neonates after delayed (42.1 ± 7.8 mL/kg) versus immediate (36.8 ± 6.3 mL/kg) cord clamping—a difference not detected indirectly by measuring Hct or estimating circulating RBC volume mathematically.

CONCLUSIONS: Because true hematologic effects of delayed versus immediate cord clamping may not be apparent or may be misinterpreted, when based on indirect measurements of Hct or calculations of circulating RBC volume, it is important to measure circulating RBC volume directly—as done with autologous, biotinylated RBCs—to document whether delayed cord clamping truly results in a transfer of significant quantities of RBCs from placenta to neonate. The clinical benefits and potential toxicities of increased RBC transfer to neonates require further studies.
Peripheral blood cell telomere length measurements indicate that hematopoietic stem cell turnover is not significantly increased in whole blood and apheresis PLT donors
Authors: Scheding Stefan , Ersöz Inci , Hartmann Ulrike , Bartolvic Kerol , Balabanov Stefan , Salama Abdulgabar , Kanz Lothar , Brümmendorf Tim H.
Published: July 2003

BACKGROUND: The telomere length (TEL) of peripheral blood leukocytes (PBLs) can be used to estimate hematopoietic stem cell turnover. The current study investigated whether the repetitive stimulation of the hematopoietic system caused by regular whole blood (WB) and PLT donations would affect PBL TEL.

STUDY DESIGN AND METHODS: PBLs were obtained from healthy donors (n=94) with a history of at least 3 years of WB donation (median, 7.7 years; range, 3.0‐43.0 years) plus additional apheresis PLT donations. The median (range) numbers of WB and PLT donations were 22.0 (6.0‐194.0) and 42.0 (7.0‐336.0), respectively. Additionally, samples were obtained from healthy nondonors (n=47). PBL TEL was measured with fluorescence in situ hybridization and flow cytometry (flow‐FISH). Flow‐FISH results were expressed in molecular equivalents of soluble fluorochrome units (MESF; 1000 MESF=1 kMESF) either as absolute (TEL) or as age‐adjusted TEL (ΔTEL).

RESULTS: Donor granulocyte and lymphocyte TELs were 12.6 ± 0.3 (mean ± SEM) and 13.2 ± 0.3 kMESF, respectively. No differences were observed when compared with corresponding nondonor data (granulocytes, 12.5 ± 0.4 kMESF; lymphocytes, 13.6 ± 0.5 kMESF). Furthermore, ΔTEL values did not differ between the two groups and were not different from previously established reference values. In addition, neither donor data for age‐adjusted TEL for granulocytes nor ΔTEL for lymphocytes were correlated with either total years or total numbers of WB and/or PLT donations.

CONCLUSION: Long‐term WB and PLT donation does not affect PBW TEL as measured by flow‐FISH, arguing against a significantly increased stem cell turnover.
Collection of WBC‐reduced single‐donor PLT concentrates with a new blood cell separator: results of a multicenter study
Authors: Moog Roger , Zeiler Thomas , Heuft Hans‐Gert , Stephan Berckard , Fischer Eike G. , Kretschmer Volker , Rödel‐Spieker Regina , Strasser Stephan , Zingsem Jürgen
Published: July 2003

BACKGROUND: A new cell separator (COM.TEC, Fresenius) was recently developed aimed at efficient collection of WBC‐reduced single‐donor PLT concentrates (SDPs).

STUDY DESIGN AND METHODS: Five German centers collected 554 WBC‐reduced SDPs with help of the COM.TEC cell separator. Two multicenter cell counting studies were performed at the beginning and at the end of the study to document uniform counting results among the participating centers.

RESULTS: A total of 441 (79.6%) PLT collections were included in the study according to the protocol. A total of 342 single‐dose and 99 double‐dose SDPs were collected. For single‐dose SDPs, an average blood volume of 2826 ± 409 mL was processed in a donation time of 55 ± 11 minutes. Mean PLT yield of these products was 3.11 × 1011± 0.40 × 1011 and the WBC contamination was 0.11 × 106± 0.20 × 106. For double‐dose SDPs (PLT count, 5.29 ± 0.93 × 1011), 3943 ± 639 mL was processed. The average difference between the target and the collected PLT concentration was −2.8 ± 12.0 percent for single‐dose SDPs and −1.8 ± 9.5 for double‐dose SDPs, respectively. The collection efficiency was 53.7 ± 5.8 percent for single‐dose SDPs and 58.2 ± 6.2 percent for double‐dose SDPs. If all results of each sample from the counting study were set to unity (to the mean over all centers), most PLT determinations were very similar to the mean, for example, near or 1 if set to unity.

CONCLUSION: The COM.TEC machine makes it possible to obtain WBC‐reduced SDPs that comply with current standards.
Mutations that diminish expression of Kell surface protein and lead to the Kmod RBC phenotype
Authors: Lee Soohee , Russo David C.W. , Reid Marion E. , Redman Colvin M.
Published: July 2003

BACKGROUND: Kmod is an inherited rare RBC phenotype characterized by weak but detectable expression of high‐incidence Kell antigens.

STUDY DESIGN AND METHODS: The 19 exons and the intron‐exon regions of the KEL gene from four unrelated Kmod individuals were sequenced and compared to wild‐type KEL. To study the mechanisms by which the mutations result in depression of Kell antigens, mutant and wild‐type Kell proteins were expressed in 293T cells and the amounts of protein present on the cell surface were determined.

RESULTS: The following point mutations were identified: Kmod−1, homozygous 1208G>A, S363N; Kmod−2, heterozygous, 1208G>A, S363N and 2150 A>G, Y677C; Kmod−3 (previously classified as KEL:−13), heterozygous 1106T>C, L329P and 1716G>A, W532Stop; Kmod−4, heterozygous, 2227G>A, G703R and a silent 1839C>T mutation. In transfected 293T cells, fewer G703R and L329P mutant Kell proteins were transported to the cell surface compared with wild‐type Kell protein, and there was no detectable Y677C mutant Kell protein. Previously, it was shown that that S363N Kell protein was not detected on the cell surface.

CONCLUSION: Different point mutations, causing amino acid substitutions and presumably altering protein conformation, inhibit transport of the mutant Kell proteins to the cell surface. The different mutations leading to the Kmod phenotype explain why anti‐Ku made by persons with the Kmod phenotype are not mutually compatible.
Extended blood grouping of blood donors with automatable PCR‐ELISA genotyping
Authors: St‐Louis Maryse , Perreault Josée , Lemieux Réal
Published: July 2003

BACKGROUND: In the past 10 years, PCR‐based methods have been described to allow the detection of gene polymorphisms responsible for many blood group antigens. These methods are routinely used to test samples of fetal origin and to resolve serologic discrepancies. Another interesting application of blood group genotyping could be the extended typing of blood donors for minor antigens to facilitate the procurement of compatible blood for alloimmunized patients.

STUDY DESIGN AND METHODS: PCR‐based tests have been modified to allow multiplex amplification of specific fragments of blood group genes and the convenient detection of hybridized amplicons by ELISA in a microplate format.

RESULTS: The results obtained show that fragments of the Rh (D, c, C, e, E), Kell (K, k), Duffy (Fya, Fyb), and Kidd (Jka, Jkb) genes could be amplified along with controls in multiplex PCR reactions. Labeling of amplicons with digoxigenin allowed their solid‐phase detection in microplate wells previously coated with individual blood group‐specific oligonucleotides. A comparative study performed with 100 individuals showed a 99.7 percent concordance between genotypes and phenotypes for the 11 antigens assayed, with only three discrepant Fyb genotypes.

CONCLUSION: Extended genotyping could be performed once on regular donors and confirmed when needed by standard serologic RBC assays. The format of these tests will allow easy automation of the procedure including the interpretation and downloading of the results with existing ELISA software.
Donor exposure to the plasticizer di(2‐ethylhexyl)phthalate during plateletpheresis
Authors: Buchta Christoph , Bittner Claudia , Höcker Paul , Macher Maria , Schmid Rainer , Seger Christoph , Dettke Markus
Published: July 2003

BACKGROUND: Di(2‐ethylhexyl)phthalate (DEHP) is a plasticizer that is contained in most PVC devices, including apheresis disposables. Because DEHP can be extracted from apheresis disposables as the blood passes through the apheresis device, DEHP exposure was determined in healthy donors undergoing plateletpheresis performed with commercially available apheresis systems.

STUDY DESIGN AND METHODS: The study population consisted of 36 healthy PLT donors undergoing plateletpheresis with either continuous or discontinuous apheresis devices. Serum concentrations of DEHP were determined from peripheral blood obtained before and after plateletpheresis, with gas chromatography‐mass spectroscopy.

RESULTS: Plateletpheresis performed with standard collection disposables resulted in a median increase of 232 percent of serum DEHP compared to levels before apheresis, corresponding to a total amount of DEHP exposed during a single apheresis of a median of 6.46 (range, 1.8‐20.3) μg per kg of body weight. Endogenous levels of triglycerides showed a positive correlation with the amount of DEHP released. Increase in serum DEHP was short‐term as serum DEHP rapidly returned to levels obtained before apheresis within 3 hours after completion of the apheresis course. Donor exposure to DEHP led to no variation in liver cell function within 48 hours after plateletpheresis.

CONCLUSION: Commercial plateletpheresis disposables release considerable amounts of DEHP during the apheresis procedure, but the total dose of DEHP retained by the donor is within the normal range of DEHP exposure of the general population.
West Nile virus infection transmitted by blood transfusion
Authors: Harrington Theresa , Kuehnert Matthew J. , Kamel Hany , Lanciotti Robert S. , Hand Sheryl , Currier Mary , Chamberland Mary E. , Petersen Lyle R. , Marfin Anthony A.
Published: July 2003

BACKGROUND: A patient with transfusion‐transmitted West Nile virus (WNV) infection confirmed by viral culture of a blood component is described. A 24‐year‐old female with severe postpartum hemorrhage developed fever, chills, headache, and generalized malaise after transfusion of 18 units of blood components; a serum sample and the cerebrospinal fluid tested positive for the presence of WNV IgM antibodies. An investigation was initiated to determine a possible association between transfusion and WNV infection.

STUDY DESIGN AND METHODS: Blood donors were assessed for recent infection through questionnaires and WNV testing of serum samples. Whole‐blood retention segments and untransfused blood components were sent to the CDC to test for the presence of WNV through PCR (TaqMan, Applied Biosystems), IgM ELISA, plaque reduction neutralization testing, and viral culture.

RESULTS: Three of 15 available donor retention segments were WNV PCR‐positive. WNV was recovered from one associated blood component. The implicated donor was symptomatic near the time of donation; serology confirmed WNV IgM seroconversion.

CONCLUSION: Seroconversion of a symptomatic donor, the presence of viral genetic material in an associated whole‐blood retention segment, and recovery of WNV from an associated component provides compelling evidence for transfusion‐acquired infection. This report has important implications for blood safety.
Combination HCV core antigen and antibody assay on a fully automated chemiluminescence analyzer
Authors: Shah Dinesh O. , Chang Chi D. , Jiang Lily X. , Cheng Kevin Y. , Muerhoff A. Scott , Gutierrez Robin A. , Leary Thomas P. , Desai Suresh M. , Batac‐Herman Irenea V. , Salbilla Vince A. , Haller Alla S. , Stewart James L. , Dawson George J.
Published: July 2003

BACKGROUND:HCV exposure among blood donors is serologically determined by detection of antibodies to HCV (anti‐HCV); however, the recent development of an assay for the detection of HCV core antigen identifies infection before anti‐HCV development. Simultaneous detection of HCV core antigen and anti‐HCV would shorten the window period before seroconversion over conventional HCV antibody screening assays.

STUDY DESIGN AND METHODS:A prototype chemiluminescent immunoassay was developed for simultaneous detection of HCV core antigen and anti‐HCV in human sera and plasma. The assay was performed on a single‐channel instrument representing an automated serologic analyzer (PRISM, Abbott Laboratories) system. Sensitivity and specificity were evaluated by testing 23 HCV seroconversion panels and plasma or sera from volunteer blood donors.

RESULTS:The prototype HCV core antigen and antibody combination assay detected 80 of 89 (89.9% ) HCV RNA‐positive and antibody‐negative specimens from 23 panels, thereby reducing the seroconversion window period by an average of 34.3 days compared to PRISM HCV antibody detection. All PRISM HCV antibody‐positive specimens were detected by the combination assay for a relative sensitivity of 100 percent. The repeatedly reactive rate was 0.20 percent based on testing of 3017 screened anti‐HCV‐negative sera and plasma.

CONCLUSIONS:The prototype combination assay was shown to detect HCV core antigen and anti‐HCV simultaneously and significantly closed the time gap between the initial detection of HCV RNA and the first appearance of detectable antibodies to HCV.
Fiber Orientation and Cell‐Cell Coupling Influence Ventricular Fibrillation Dynamics
Authors: Choi Bum‐Rak , Liu Tong , Lavasani Mitra , Salama Guy
Published: July 2003

Introduction: The structure of ventricular fibrillation (VF) is influenced by regional differences in action potential durations and perhaps restitution kinetics and fiber anisotropy. The spatial organization of VF was investigated by measuring the cross‐correlation (CC) and mutual information (MI) of membrane potential (Vm) oscillations recorded from multiple sites.

Methods and Results: Rabbit hearts (n = 6) were retrogradely perfused and stained with di‐4‐ANEPPS, and VF was elicited by burst pacing. Vm oscillations were recorded optically from multiple locations on the epicardium using a 16 × 16 photodiode array or a 72 × 78 CCD camera. The spatial organization of VF was investigated by calculating the maximum CC (CCmax) and MI (MImax) that can be obtained between any two sites. CCmax and MImax were extended to all pixels and served as indices of the similarities between Vm transients at a reference pixel and all other pixels on the map. We found that maps of CCmax and MImax did not contain discrete regions with high CC or MI. However, CCmax and MImax decreased monotonically with increasing distance between any arbitrarily chosen reference pixel and all other pixels. In VF, maps of CCmax and MImax revealed elliptical gradients of CC and MI that were closely aligned with fiber orientation, with major axis at 127°± 8° on the left ventricles.

Conclusion: CC and MI analysis in fibrillation provides new evidence that anisotropy of fiber orientation and cell‐cell coupling have a direct influence on VF dynamics. (J Cardiovasc Electrophysiol, Vol. 14, pp. 851‐860, August 2003)
Defibrillation Efficacy and Pain Perception of Two Biphasic Waveforms for Internal Cardioversion of Atrial Fibrillation
Authors: Jung Jens , Siaplaouras Stephanos , Buob Axel , Schubert Bernd D. , Hahn Stephen J. , Heisel Armin
Published: July 2003

Introduction: We evaluated the influence of the peak voltage of waveforms used for internal cardioversion of atrial fibrillation on defibrillation efficacy and pain perception. A low peak voltage biphasic waveform generated by a 500‐μF capacitor with 40% tilt was compared to a standard biphasic waveform generated by a 60‐μF capacitor with 80% tilt.

Methods and Results: In 19 patients with paroxysmal atrial fibrillation (79% male, age 55 ± 11 years, 21% with heart disease), the atrial defibrillation threshold (ADFT) was determined during deep sedation with midazolam for both waveforms in a randomized fashion using a step‐up protocol. Internal cardioversion with a single lead (shock vector: coronary sinus to right atrium) was successful in 18 (95%) of 19 patients. ADFT energy and peak voltage were significantly lower for the low‐voltage waveform (2.1 ± 2.4 J vs 3.5 ± 3.9 J, P < 0.01; 100 ± 53 V vs 290 ± 149 V, P < 0.01). Sedation then was reversed with flumazenil after ADFT testing. Two shocks at the ADFT (or a 3‐J shock if ADFT >3 J) were administered to the patient using each waveform in random order. Pain perception was assessed using both a visual scale and a numerical score. ADFTs were above the pain threshold in 17 (94%) of 18 patients, even though the ADFT with the 500‐μF waveform was <100 V in 63% of the patients. Pain perception was comparable for both waveforms (numerical score: 6.5 ± 2.4 vs 6.3 ± 2.6; visual scale: 5.4 ± 2.6 vs 5.2 ± 3.1; P = NS, 500‐μF vs 60‐μF). The second shock was perceived as more painful in 88% of the patients, independent of the waveform used.

Conclusion: Despite a 66% lower peak voltage and a 40% lower energy, the 40% tilt, 500‐μF capacitor biphasic waveform did not change the pain perceived by the patient during delivery of internal cardioversion shocks. Pain perception for internal cardioversion probably is not influenced by peak voltage alone and increases with the number of applied shocks. (J Cardiovasc Electrophysiol, Vol. 14, pp. 837‐840, August 2003)
Prognostic Significance of Heart Rate Turbulence Following Ventricular Premature Beats in Patients with Idiopathic Dilated Cardiomyopathy
Authors: Grimm Wolfram , Sharkova Julia , Christ Michael , Müller Hans‐Helge , Schmidt Georg , Maisch Bernhard
Published: July 2003

Introduction: The aim of this study was to investigate the prognostic significance of heart rate turbulence (HRT) characterized by HRT onset and slope after ventricular premature beats in patients with idiopathic dilated cardiomyopathy (IDC).

Methods and Results: Blinded HRT analysis was performed in 242 patients with IDC who were enrolled in the Marburg Cardiomyopathy database between 1992 and 2000. During 41 ± 23 months of follow‐up, 54 patients (22%) died or underwent heart transplant. On Cox univariate regression analysis, abnormal HRT onset, HRT slope, HRT onset combined with HRT slope, left ventricular (LV) ejection fraction, LV size, and New York Heart Association (NYHA) functional class III showed a significant association with total mortality or the need for heart transplant. On multivariate analysis, abnormal HRT onset identified patients without transplant‐free survival, as did LV size and NYHA class III heart failure. Major arrhythmic events were observed in 42 patients (17%) during follow‐up. On univariate analysis, abnormal HRT onset, HRT onset combined with HRT slope, male sex, NYHA class III, LV ejection fraction, and LV size were associated with a higher incidence of major arrhythmic events. On multivariate analysis, only LV ejection fraction remained as a significant arrhythmia risk predictor, with a relative risk of 2.2 per 10% decrease in ejection fraction (95% confidence interval 1.5–3.2).

Conclusion: In this selected patient population with IDC, HRT onset is a significant predictor of transplant‐free survival, as are LV size and NYHA class. For arrhythmia risk stratification, however, only LV ejection fraction remained a significant risk predictor on multivariate analysis. (J Cardiovasc Electrophysiol, Vol. 14, pp. 819‐824, August 2003)
Mesenchymal Stem Cell Injection Induces Cardiac Nerve Sprouting and Increased Tenascin Expression in a Swine Model of Myocardial Infarction
Authors: Pak Hui‐Nam , Qayyum Mohammed , Kim Dave T. , Hamabe Akira , Miyauchi Yasushi , Lill Michael C. , Frantzen Malkar , Takizawa Kaname , Chen Lan S. , Fishbein Michael C. , Sharifi Behrooz G. , Chen Peng‐Sheng , Makkar Raj
Published: July 2003

Introduction: Mesenchymal stem cell (MSC) transplantation is a promising technique to improve cardiac function. Whether MSC can increase cardiac nerve density and contribute to the improved cardiac function is unclear.

Methods and Results: Anterior wall myocardial infarction was created in 16 swine. One month later, 6 swine were given MSC and fresh bone marrow (BM) into infarcted myocardium (MSC group). Four swine were given fresh BM only (BM group), and 6 swine were given culture media (MI‐only group). The swine were sacrificed 95.8 ± 3.5 days after MI. Six normal swine were used as control. Immunocytochemical staining was performed using antibodies against growth‐associated protein 43 (GAP43), tyrosine hydroxylase (TH), and three subtypes of tenascin (R, C, and X). Five fields per slide were counted for nerve density. The results show the following. (1) There were more GAP43‐positive nerves in the MSC group than in the BM, MI‐only, or Control group (P < 0.0001). TH staining showed higher nerve densities in the MSC group than in the MI‐only (P < 0.01) or Control group (P < 0.0001) in the atria. (2) There were more sympathetic (TH‐positive) nerves in myocardium distant from infarct than in the peri‐infarct area (P < 0.05). (3) Optical intensity and color analyses showed significantly higher tenascin R and tenascin C expression in the MSC and BM groups than in the MI‐only or Control group (P < 0.01).

Conclusion: MSC injected with BM into swine infarct results in overexpression of cardiac tenascin, increased the magnitude of cardiac nerve sprouting in both atria and ventricles, and increased the magnitude of atrial sympathetic hyperinnervation 2 months after injection. (J Cardiovasc Electrophysiol, Vol. 14, pp. 841‐848, August 2003)
The Atrial Pacing Peri-ablation for Paroxysmal Atrial Fibrillation (PA3) Study
Authors: Gillis A. M.
Published: July 2003

The Canadian Atrial Pacing Peri-Ablation for Paroxysmal Atrial Fibrillation Study tested the hypotheses that atrial pacing prevents paroxysmal atrial fibrillation (PAF) in patients without symptomatic bradycardia and that DDDR pacing is more likely to prevent PAF following total atrioventricular (AV) node ablation compared to VDD pacing. Patients with PAF who were refractory to or intolerant of antiarrhythmic drug therapy received a Medtronic Thera DR pacemaker 3 months prior to a planned total AV node ablation. Patients were randomized to atrial pacing or no pacing therapy. The time to first recurrence of sustained PAF was the primary study outcome event. Following AV node ablation, patients were randomized to the DDDR or VDD mode in a crossover study design. Patients were followed in each mode for 6 months. The time course of PAF recurrence was compared for each pacing mode.
The Pollen Tube Pathway inTasmannia insipida(Winteraceae): Homology of the Male Gametophyte Conduction Tissue in Angiosperms
Authors: Frame D.
Published: July 2003

Abstract:The pathway of the pollen tube inTasmannia insipida(Winteraceae), an archaic angiosperm, is described. Visual observations and measurements of percentage sugar content from stigmatic exudate and the calyptra droplet were made. The droplet that forms on the calyptra of unopened flowers was artificially pollinated, but no pollen tubes appeared to grow through it to the gynoecium of female flowers. Calyptra droplets occur on both female and male (having reduced female structures) flowers of this dioecious plant. It is considered unlikely that a drop pollination mechanism, analogous to that found in some gymnosperms, is at work inT. insipida,and it is proposed that one possible droplet function is as a “reward” to potential pollinators in advance of flower opening. Pollen tubes were observed to grow almost exclusively along epidermal cells. Early thoughts on angiosperm transmission tissue are re‐examined and built upon. It is proposed that the male gametophyte conduction tissue in angiosperms is homologous with epidermal tissue, and that pollen tube passage occurred originally solely along the surface of specialized epidermal cells, or possibly for short distances along unspecialized regions covered with exudate derived from these cells. Some earlier attempts to explain transmitting tissue homology and evolution are discussed.
Ultrastructural Changes in Cambial Cell Derivatives during Xylem Differentiation in Poplar
Authors: Arend M. , Fromm J.
Published: July 2003

Abstract: The changes in cellular structures that occur in cambial cell derivatives during xylogenesis were examined in Populus trichocarpa Torr et Gray. During dormancy, the cells of the vascular cambium are characterised by dense cytoplasm, many small vacuoles and lipid bodies. During cambial activation, cambial cells are highly vacuolated, the cytoplasm is rich in organelles and the nucleus contains distinctly enlarged nucleoli. The plasma membrane forms vesicle‐filled invaginations which mediate uptake of vesicular material into the vacuole. The mitotic patterns in dividing fusiform cells are fragmentary due to their strong vacuolisation. During cell enlargement, cambial cell derivatives remain strongly vacuolated and cytoplasmic structures are similar to active fusiform cells. From the beginning of secondary cell wall formation many changes in cytoplasmic structures occur in newly‐formed fibres and vessels. In fibres, the cytoplasm is characterised by components of secondary cell wall synthesis, as indicated by increased amounts of endoplasmic reticulum, vesicle‐producing dictyosomes and microtubules. In contrast, vessels show a more or less distinct occurrence of these components and remain more strongly vacuolated than fibres. Similar to cambial cells, a distinct flow of vesicular material into the vacuole through invaginations of the plasma membrane is apparent in fibres, as well as in vessels. After completion of the secondary cell walls, the loss of tonoplast integrity causes the collapse of the vacuole and initiates cell death in vessels and fibres. In vessels the tonoplast exhibits unusually strong staining prior to the collapse of the vacuole, indicating subsequent cell death. Overall, our results indicate an important role for the vacuole in the xylogen differentiation of cambial derivatives.
A Comparison of the Sucrose Transporter Systems of Different Plant Species
Authors: Kühn C.
Published: July 2003

Abstract: The sucrose uptake behaviour of many different plant species is characterised by the presence of at least two components with distinct kinetic properties. These include at least one high‐affinity and one low‐affinity transport system. All known sucrose transporters from higher plants fall into one of three large subfamilies, according to phylogenetic analysis. Apparently, the largest subfamily, the SUT1 subfamily, exclusively consists of high‐affinity sucrose transporters from dicotyledons, whereas none of the transporters from monocotyledonous plants groups within this subfamily. The other two subfamilies of sucrose transporter‐like proteins are either low‐affinity transporter or putative sucrose‐sensing proteins. Most of the known sucrose transporters from monocotyledons are closely related to the SUT2 subfamily and include high‐affinity transporters, suggesting a different evolutionary origin of dicotyledonous and monocotyledonous sucrose transporter gene families.
Whole Plant Regulation of Sulfur Nutrition of Deciduous Trees‐Influences of the Environment
Authors: Herschbach C.
Published: July 2003

Abstract: The current view of sulfur nutrition is based on the source‐to‐sink relationship of carbohydrates. SO42‐ reduction is thought to occur mainly in leaves. Surplus reduced sulfur must be transported out of the leaves, loaded into the phloem and transported to other tissues, in particular tissues assumed to be sink organs. However, it has not been proved that tissues which are sinks for carbohydrates are also sink organs for reduced sulfur. It is evident that sinks must communicate with sources, and vice versa, to signal demand and to transport the surplus of reduced sulfur that is produced. The demand‐driven control model of sulfur nutrition proposes that the tripeptide glutathione is the signal which regulates S nutrition of the whole plant at the level of SO42‐ uptake. Acclimatization to environmental changes has been shown to result in several changes in S nutrition of deciduous trees: (i) Drought stress diminished SO42‐ transport into the xylem, although the GSH content in lateral roots remained unaffected, possibly due to an overall reduction in water status. (ii) Flooding decreased APS reductase activity in the anoxic roots. This may be due to enhanced GSH transport to the roots, but it is more likely to be the result of a change in metabolism leading to diminished energy gain in the roots. (iii) Mycorrhization enhanced the GSH content in the phloem, while SO42‐ uptake was not affected. This clearly goes against the demand‐driven control model. (iv) Under both short‐ and long‐term exposure to elevated pCO2, the APS reductase activity in leaves and lateral roots did not correlate with the GSH contents therein. Therefore, it must be assumed that, under these conditions, regulation of S nutrition goes beyond the demand‐driven control model, and occurs within the network of other nutrient metabolism. (v) Atmospheric S in the form of H2S enhanced the reduced sulfur content of the phloem and lateral roots. Under these conditions, the SO42‐ loaded into the xylem decreased. It would appear that the demand‐driven control model of sulfur nutrition is not always valid in the case of deciduous trees.
Telomere Length Dynamics in Pearl Millet (Pennisetum glaucum [L.] R. Br.) as Observed at Different Developmental Stages
Authors: Devi K. Uma , Sri Devi V. , Nirmal K. , Sivaramakrishnan S. , Isola N. R.
Published: July 2003

Abstract: In plants, the developmental dynamics of telomere length have only been studied in a few species to date. Contrasting results have been reported. To search for the pattern(s) operating in plants, a study of the telomere length was made in pearl millet. Telomere length in cells representing different developmental stages: a) embryo, b) leaves of 1‐week‐old seedlings, 1‐month‐old plants and boot leaf and c) germ cells (pollen) were compared. The presence of the consensus plant telomere repeat sequence (5′‐TTTAGGG‐3′) in pearl millet telomeres was first ascertained; the sensitivity of the sequences hybridizing with (TTTAGGG)4 oligonucleotide to time course Bal 31 exonuclease digestions were studied on dot blots and gel blots. The exonuclease digestion kinetics revealed the presence of the consensus telomere repeat sequence in pearl millet telomeres. The average telomere length (ATL) was measured from autoradiograms of Hae III digested DNA, hybridized with labelled (5'‐TTTAGGG‐3′)4 oligonucleotide using “UVI band” software. No significant difference in the average telomere length was observed between the embryo, leaves of 1‐week‐old seedlings, boot leaf and pollen. The ATL in leaves of 1‐month‐old plants was slightly higher. The results of the present investigation and analysis of the reports in the other plants suggest that there is an occasional increase in telomere length in some telomeres but no significant decrease due to loss during DNA replication.
Fluorescence spectra of NH2 X̃ 2B1←Ã 2A1 Σ bands: Experiment and theory
Authors: Petrongolo Carlo , Fan Haiyan , Ionescu Ionela , Kuffel David , Reid Scott A.
Published: July 2003

We report new calculations and measurements of fluorescence properties of the title system, which is important in astrochemical processes. Dispersed fluorescence spectra show extensive X̃ 2B1 vibrational progressions that depend on the initial Ã 2A1 state. Observed and calculated (0,ν2′,0)Σ lifetimes are in good accord, save for ν2′=4 (bent molecule notation), and calculated (1,ν2′−2,0)Σ lifetimes are longer than the (0,ν2′,0)Σ ones. The calculated laser-induced fluorescence spectrum is compared with experimental absorption data and with previous calculations, finding that the present treatment underestimates the intensity of the (0,4,0)Σ band.
Adsorption and depletion of polyelectrolytes from charged surfaces
Authors: Shafir Adi , Andelman David , Netz Roland R.
Published: July 2003

Mean-field theory and scaling arguments are presented to model polyelectrolyte adsorption from semidilute solutions onto charged surfaces. Using numerical solutions of the mean-field equations, we show that adsorption exists only for highly charged polyelectrolytes in low salt solutions. Simple scaling laws for the width of the adsorbed layer and the amount of adsorbed polyelectrolyte are obtained. In other situations the polyelectrolyte chains will deplete from the surface. For fixed surface potential conditions, the salt concentration at the adsorption–depletion crossover scales as the product of the charged fraction of the polyelectrolyte f and the surface potential, while for a fixed surface charge density, σ, it scales as σ2/3f2/3, in agreement with single-chain results.