bluuebunny/crossref_metadata_2025 huggingface dataset:
Generation of annexin V‐positive platelets and shedding of microparticles with stimulus‐dependent procoagulant activity during storage of platelets at 4°C
Authors: Xiao H.Y. , Matsubayashi H. , Bonderman D.P. , Bonderman P.W. , Reid T. , Miraglia C.C. , Gao D.Y.
Published: March 2003

BACKGROUND: The ability of propyl gallate to activate platelet factor 3 has been determined through the activated partial thromboplastin time, but its effect on phosphatidylserine has not been established.

STUDY DESIGN AND METHODS: A novel platelet activator, propyl gallate, was introduced to a study of platelets stored at 4°C. The effects of storage on platelet coagulation activity, on phosphatidylserine, and on the shedding of activated and activable membrane particles (microparticles) were examined by activated plasma clotting time, and the effect on annexin V binding was examined by gated flow cytometry. The ratios of annexin V binding and microparticle shedding in stored platelet samples were compared with those in fresh platelets stimulated with propyl gallate.

RESULTS: Microparticle shedding by stored platelets compensated for the diminished procoagulant potential of intact platelets (shown as the total propyl gallate‐dependent platelet factor 3 activity), which did not change during prolonged (20‐day) storage, but levels of phosphatidylserine confined to microparticles increased dramatically as platelet counts fell. Both annexin V binding and microparticle shedding increased spontaneously with storage and artificially with propyl gallate stimulation. However, at the same level of annexin V binding, stored platelets shed more microparticles than did fresh platelets stimulated with propyl gallate.

CONCLUSION: Propyl gallate induces platelet procoagulant activity and annexin V binding. Stored platelets differ from fresh platelets in a lower reactivity to propyl gallate activation and a higher rate of microparticle shedding.
In vitro collection and posttransfusion engraftment characteristics of MNCs obtained by using a new separator for autologous PBPC transplantation
Authors: Snyder E.L. , Baril L. , Cooper D.L. , Min K. , Mechanic S. , Stoddart L. , Burtness B. , Seagraves P. , Debelak J. , Gudino M. , McCullough J.
Published: March 2003

BACKGROUND: A clinical study was performed to evaluate the peripheral blood progenitor cell (PBPC) collection, transfusion, and engraftment characteristics associated with use of a blood cell separator (Amicus, Baxter Healthcare).

STUDY DESIGN AND METHODS: Oncology patients (n = 31) scheduled for an autologous PBPC transplant following myeloablative therapy were studied. PBPCs were mobilized by a variety of chemotherapeutic regimens and the use of G–CSF. As no prior studies evaluated whether PBPCs collected on the Amicus separator would be viable after transfusion, to ensure patient safety, PBPCs were first collected on another cell separator (CS‐3000 Plus, Baxter) and stored as backup. The day after the CS‐3000 Plus collections were completed, PBPC collections intended for transfusion were performed using the Amicus instrument. For each transplant, >2.5 × 106 CD34+ PBPCs per kg of body weight were transfused.

RESULTS: Clinical data collected on the donors immediately before and after PBPC collection with the Amicus device were comparable to donor data similarly obtained for the CS‐3000 Plus collections. While the number of CD34+ cells and the RBC volume in the collected products were equivalent for the two devices, the platelet content of the Amicus collections was significantly lower than that of the CS‐3000 Plus collections (4.35 × 1010 platelets/bag vs. 6.61 × 1010 platelets/bag, p<0.05). Collection efficiencies for CD34+ cells were 64 ± 23 percent for the Amicus device and 43 ± 14 percent for the CS‐3000 Plus device (p<0.05). The mean time to engraftment for cells collected via the Amicus device was 8.7 ± 0.7 days for >500 PMNs per μL and 9.7 ± 1.5 days to attain a platelet count of >20,000 per μL—equivalent to data in the literature. No CS‐3000 Plus backup cells were transfused and no serious adverse events attributable to the Amicus device were encountered.

CONCLUSIONS: The mean Amicus CD34+ cell collection efficiency was better (p<0.05) than that of the CS‐3000 Plus collection. Short‐term engraftment was durable. The PBPCs collected with the Amicus separator are safe and effective for use for autologous transplant patients requiring PBPC rescue from high‐dose myeloablative chemotherapy.
The effects of phosphate, pH, and AS volume on RBCs stored in saline‐adenine‐glucose‐mannitol solutions
Authors: Hess J.R. , Lippert L.E. , Derse‐Anthony C.P. , Hill H.R. , Oliver C.K. , Rugg N. , Knapp A.D. , Gormas J.F. , Greenwalt T.J.
Published: March 2003

BACKGROUND: RBC ATP concentrations are the most important correlate of RBC viability. Tests were performed to determine whether increased AS volume, pH, and phosphate content increased stored RBC ATP concentrations.

STUDY DESIGN AND METHODS: In three studies, packed RBCs were pooled in groups of 3 or 4 units and realiquoted as combined units to reduce intradonor differences. Pooled units were stored in the licensed ASs, AS‐1 or AS‐5, which contain saline, adenine, glucose, and mannitol (SAGM), or in experimental ASs (EASs) containing SAGM and disodium phosphate. Ten pools were stored in AS‐1 at RBC concentrations equivalent to 100, 200, or 300 mL of AS. Six pools were stored in 100, 200, 300, or 400 mL volumes of EAS‐61. Ten pools were stored in 100 mL of AS‐5, 200 mL of EAS‐61, or 300 mL of EAS‐64. RBC ATP concentration and other measures of RBC metabolism and function were measured weekly.

RESULTS: RBC ATP concentrations decreased sooner with storage in increasing volumes of AS‐1. In EAS‐61 and EAS‐64, RBC ATP concentrations initially increased and stayed elevated longer with increasing AS volume.

CONCLUSIONS: The addition of disodium phosphate to SAGM AS increases the RBC ATP concentrations. Reducing storage Hct appears to have a separate beneficial effect in reducing hemolysis.
Cord blood as a source of autologous RBCs for transfusion to preterm infants
Authors: Eichler Hermann , Schaible Thomas , Richter Ekkehard , Zieger Wolfgang , Voller Katrin , Leveringhaus Andreas , Goldmann Shraga F.
Published: March 2003

BACKGROUND: This prospective study was conducted to gain experience as to whether it is technically possible to produce autologous RBCs in additive solution from cord blood (CB), to optimize the blood supply for preterm infants.

STUDY DESIGN AND METHODS: CB was collected from 47 infants with a mean (± SD) birth weight of 1717 (± 699) g. Whenever possible, RBC components were prepared by standard centrifugation using a six‐bag system. All samples were put in sterility testing quarantine for 5 days, and a maximum storage of 14 days from collection to transfusion was specified. The babies were given either the autologous RBCs or standard allogeneic RBC concentrates, if autologous blood was not available.

RESULTS: In 81 percent of the samples, autologous RBC components could be processed (vol, 7‐87 mL; Hct, 31‐82%). But within the group of extremely low birth weight infants (body weight <1000 g), a mean CB net volume of only 37 mL was collected, and the RBC preparation was successful only in exceptional cases. Three CB samples (8.6%) tested positive in sterility testing. Of the 47 infants, 21 were treated with a total of 62 allogeneic and 4 autologous RBC transfusions. Most infants with a body weight over 1400 g did not need any RBC transfusion.

CONCLUSION: The preparation of autologous RBCs from the CB of preterm infants is technically possible in principle. However, major concerns must be raised as to whether such preparations are of benefit in ensuring safe care of neonates with blood components, with respect to the high rate of bacterial contamination and the limited availability in babies with low birth weight.
Leukapheresis components may be cryopreserved at high cell concentrations without additional loss of HPC function
Authors: Cabezudo Elena , Dalmases Clara , Ruz Maria , Sanchez Jose Antonio , Torrico Carlos , Sola Claudio , Querol Sergi , García Joan
Published: March 2003

BACKGROUND: The aim of this study was to assess the feasibility of freezing mobilized peripheral blood progenitor cell (PBPC) components at higher cell concentrations than are classically recommended for bone marrow. This approach might have potential benefits, such as lower cost of processing and storage and less risk of the complications associated with the transfusion of large component volumes and large quantities of DMSO.

STUDY DESIGN AND METHODS: In the first phase, small aliquots of 19 apheresis components were cryopreserved at standard and higher cell concentrations (Aliquots A and B, respectively). In the second phase, 21 apheresis components were split into two bags each and frozen at standard (Bag A) and high (Bag B) cell concentrations. The differences in viability, cloning efficiency, and nucleated cell recovery in Bags A and B were examined. Finally, the hematologic recovery of 10 patients who underwent autologous transplantation with PBPC components frozen at high cell concentrations was analyzed.

RESULTS: The median cell concentration at freezing was 94 (57‐100) × 106 per mL and 291 (220‐467) × 106 per mL for Aliquots A and B, respectively, and 90.9 (45.4‐92) × 106 per mL and 332 (171‐582) × 106 per mL for Bags A and B, respectively. The viability was significantly lower in samples frozen at higher cell concentrations: 92 versus 83 percent (p = 0.001) and 87 versus 77 percent (p<0.001) for Aliquots and Bags A and B, respectively. Significant differences were not observed in the recovery of total nucleated cells (102 vs. 101% and 98 vs. 105%) or the cloning efficiency after thawing (13 vs. 16% and 27 vs. 23%) for Aliquots and Bags A and B, respectively. The time to granulocyte engraftment >0.5 × 109 per L and platelet engraftment >20 × 109 per L was 9 (8‐11) and 10.5 (7‐21) days, respectively.

CONCLUSION: The cryopreservation of PBPC components at standard concentrations and 3.3 (1.8‐6.2)‐fold cell concentrations has no adverse effect on the function of HPCs after thawing.
Fy phenotype and gender determine plasma levels of monocyte chemotactic protein
Authors: Jilma‐Stohlawetz Petra , Homoncik Monika , Drucker Christa , Marsik Claudia , Rot Antal , Mayr Wolfgang R. , Seibold Brigitte , Jilma Bernd
Published: March 2003

BACKGROUND: In vitro studies indicate that the Fy blood group system antigens serve as receptors for chemokines such as monocyte chemotactic protein‐1 (MCP‐1) and RANTES. However, it is unclear whether subjects with the Fy(a−b−) phenotype exhibit altered clearance and hence altered plasma levels of chemo‐kines, because they still express Fy on endothelial cells.

STUDY DESIGN AND METHODS: To clarify a possible in vivo role of Fy on RBCs in the regulation of chemo‐kine levels, healthy young volunteers of common Fy phenotypes were compared in a cross‐sectional study.

RESULTS: More than 90 percent of the 34 subjects of African origin were Fy(a−b−), one black volunteer was Fy(a+b−), and two were Fy(a−b+). As expected, all 65 white volunteers were positive for either Fya and/or Fyb. Unexpectedly, persons expressing either Fya and/or Fyb had significantly higher plasma levels of MCP‐1 than Fy(a−b−) volunteers (women: 154 vs. 110 ng/L, p<0.01; men: 179 vs. 169 ng/L, p = 0.03). Surprisingly, plasma levels of MCP‐1 were found to be sex‐dependent: median MCP‐1 levels averaged 180 ng per L in men but only 139 ng per L in women (p<0.001). Further, MCP‐1 levels decreased significantly throughout the menstrual cycle of 18 women studied longitudinally.

CONCLUSION: MCP‐1 levels are about 30 percent higher in men than in premenopausal women, and MCP‐1 levels are also higher in persons with RBCs expressing Fy antigens than in Fy(a−b−) persons. These findings have direct implications for the concept and interpretation of clinical studies measuring MCP‐1 levels; the role of the observed differences in MCP‐1 levels for the pathogenesis of MCP‐1‐dependent diseases, such as atherosclerosis, merits further investigation.
Detection of fetal HPCs in maternal circulation after delivery
Authors: Osada Hisao , Doi Shigeharu , Fukushima Takashi , Nakauchi Hiromitsu , Seki Katsuyoshi , Sekiya Souei
Published: March 2003

BACKGROUND: Circulation of mature fetal blood cells in the maternal blood for a certain postpartum period has been verified, but detailed study of the fetal HPCs has not been reported. The objective of this study was to evaluate the frequency and clearance of these cells in the peripheral blood of puerperal women.

STUDY DESIGN AND METHODS: PBMNCs from 15 puerperal women who gave birth to male infants were cultured in semi‐solid medium containing hematopoietic stimulating factors. Colonies formed in the medium were individually characterized, collected, and subjected to PCR amplification of the SRY gene on Y chromosome to confirm fetal origin.

RESULTS: The mean numbers of fetal progenitor cell colonies isolated per mL of maternal blood were 1.63, 2.48, 0.56, 0.12, and 0 on the day of delivery, at 4 days, 1 month, 6 months, and 1 year after delivery, respectively. There was no difference in the ratio of fetal versus maternal colonies between erythroid and granulocyte/macrophage lineages.

CONCLUSION: The present study demonstrated that a significant number of fetal HPCs circulate in the maternal blood for a duration of at least 6 months after delivery.
Validating billing data for RBC transfusions: a brief report
Authors: Segal Jodi B. , Ness Paul M. , Powe Neil R.
Published: March 2003

BACKGROUND: Administrative data are used often for research, but without validation of their accuracy. The validity of the billing for blood transfusion was assessed in one tertiary‐care hospital.

MATERIALS AND METHODS: Patient discharge data were retrieved from a database containing demographics, diagnoses, and charges. There was random selection of 358 patients who were billed for RBC transfusion and 358 who were not, within a 2‐month period. The blood bank's transfusion records were reviewed. Sensitivity was defined as the proportion of transfused patients who were billed, and specificity as the proportion of nontransfused patients who were not billed. Patient characteristics were compared by using Wilcoxon's rank sum test and the chi‐square test.

RESULTS: Sixty‐one transfused patients were not billed for the transfusion. No patient was billed without transfusion. Thus, the sensitivity and specificity were 83 percent (95% CI, 79‐87%) and 100 percent, respectively. Nine patients who were not issued RBCs were appropriately not billed for RBCs, although the billing record suggests they had a procedure involving transfusion. These patients were called true‐negative. The patients not billed were older (58 years vs. 55 years; p = 0.046) and less likely to have commercial insurance (5% vs. 15%; p = 0.035) than billed patients.

CONCLUSIONS: The billing for RBC transfusion in one large institution is reassuringly valid. The specificity is excellent, and the sensitivity is higher than that seen in other studies of coding validity.
Prolonged iron depletion afterallogeneic 2‐unit RBC apheresis
Authors: Högler Wolfgang , Mayer Wolfgang , Messmer Christian , Eibl Günther , Innerhofer Petra , Schönitzer Diether , Nussbaumer Walter
Published: March 2003

BACKGROUND: Allogeneic 2‐unit RBC apheresis is a safe procedure offering many advantages for donors and blood banks. A controlled study was performed to determine whether the recommended minimum interval of 4 months between 2‐unit RBC apheresis donations is appropriate in terms of the recovery of RBCs and the regeneration of iron stores.

STUDY DESIGN AND METHODS: Twenty male subjects each donated 2 units of RBCs by apheresis. The RBC count, reticulocyte count, EPO, and measures of iron status were analyzed before and during the 4 months after donation.

RESULTS: A significant decrease in Hb (15.89 ± 0.82 [mean ± SD] vs. 14.08 ± 0.97 mg/dL, baseline vs. Day 7; p<0.001) was equalized within 2 months. In contrast, ferritin values declined significantly from 54.2 ± 33.7 to 23.42 ± 21.94 μg per L (predonation vs. Day 30) and remained significantly below predonation values, but within the normal range, until the end of the study period.

CONCLUSION: A donation interval of 4 months is appropriate in terms of RBC recovery, but may not be appropriate in terms of iron store regeneration. The tendency to shorten the donation interval should be reconsidered in light of the measurements of iron storage. The use of ferritin levels is recommended as a preselection criterion for allogeneic 2‐unit RBC apheresis.
Health and economic consequences of HCV lookback
Authors: Pereira Arturo
Published: March 2003

BACKGROUND: Several countries have conducted or are considering campaigns of lookback on blood recipients who may have acquired posttransfusion HCV (PT‐HCV) before the implementation of anti‐HCV screening. There is, however, no estimation of the health and economic consequences of the medical interventions triggered by the lookback.

STUDY DESIGN AND METHODS: This study used a Monte Carlo simulation of a Markov model representing the natural history of PT‐HCV. Unadjusted and quality‐adjusted life expectancy and lifetime medical costs were calculated for a cohort of patients in whom PT‐HCV is diagnosed through the lookback, and these values were compared with those calculated for a similar cohort on whom lookback is not performed.

RESULTS: The model predicts that 47 percent of people who received transfusions of HCV‐infective blood 10 years ago are still alive, carry the infection, and have not yet progressed to end‐stage liver failure. In this population, forthcoming complications of PT‐HCV will reduce the remaining life expectancy by 1.75 years per patient. Medical interventions triggered by the diagnosis of PT‐HCV would salvage 0.123 years of life expectancy, at a net cost of $921 per newly diagnosed patient. The health and economic impact of diagnosing a new case of PT‐HCV through lookback was sensitive to the patient's age, the efficacy of antiviral therapies, the time elapsed from transfusion to lookback, and the future inflation of costs of treating end‐stage liver disease. Under some plausible assumptions, the intervention could result in net financial savings for the health care system, but it may also produce a net health loss for the majority of patients who will be said to be HCV‐positive without being offered an effective therapy.

CONCLUSION: Diagnosis of PT‐HCV through HCV lookback has a potential both to increase patients' life expectancy and to reduce health care costs. However, more effective antiviral therapies and a better knowledge of factors predicting the progression of PT‐HCV are needed to attain those goals. Meanwhile, care should be taken to avoid pursuing a health gain for a minority that might result in a health loss for the majority.
Ex vivo evaluation of PBMNCs collected with a new cell separator
Authors: Snyder Edward L. , O'Donnell Lynn , Dengler Thomas J. , Pomper Gregory J. , Velleca Mark A. , Dincecco Dorothy M. , Baril Laurene L. , Min Kyungyoon , Gudino Maria D. , Bender Jeffrey R.
Published: March 2003

BACKGROUND: This study reports on an evaluation of the ability of a cell separator (Amicus, Baxter Healthcare) and the integral MNC computer software program to collect a variety of MNC subsets. The collection efficiency (CE) of the Amicus for these MNC subsets was compared to that of another cell separator (CS‐3000 Plus, Baxter). The collected MNCs were also assayed ex vivo to determine if these cells remained functional.

STUDY DESIGN AND METHODS: Healthy volunteer blood donors were recruited to provide PBMNCs for the isolation of CD3+, CD4+, CD8+, CD19+, NK, and γδ+ cells and monocytes. Cells were collected with an Amicus (test arm; n = 16) or a CS‐3000 Plus (control arm; n = 11) cell separator. Cells were counted on a flow cytometer and CEs were calculated. For functional studies, the Amicus‐collected MNC data were compared to CS‐3000 Plus historical data. Functional studies performed included surface antigen expression assays (CD8+), proliferation assays (CD4+ and CD8+ cells), NK cytotoxicity assays for K562 and HUVE cells, and E‐selectin induction on endothelial cells through NK+ contact dependency. Dendritic cells (DCs) were generated from CD34+ cells collected on the Amicus, positively selected by the use of antibody‐bound, magnetic bead technology, and then cultured ex vivo with a combination of growth factors to generate the DCs.

RESULTS: CEs were higher on the Amicus than on the CS‐3000 Plus for CD3+ (68 vs. 54%), CD4+ (70 vs. 56%), CD8+ (68 vs. 52%), and CD19+ (60 vs. 48%) cells (p<0.05). For the two separators, CEs were equivalent for monocytes, NK+, and γδ+ cells. The Amicus separator collected significantly fewer platelets than did the CS‐3000 Plus (p<0.00001). CD4+, CD8+, and NK cells proliferated normally. NK cells appropriately stimulated E‐selectin expression on endothelial cells. Culture‐generated DCs obtained by using Amicus‐collected CD34+ cells expressed appropriate cell surface markers.

CONCLUSION: The Amicus separator is acceptable for the collection of PBMNC subsets. The device collects CD3+, CD4+, CD8+, and CD19+ T‐ and B‐cell subsets with greater efficiency and collects MNCs with significantly fewer contaminating platelets than does the CS‐3000 Plus. Cells collected on the Amicus are suitable for use in a variety of research and clinical immunobiologic studies.
Evaluation of a concurrent multicomponent collection system for the collection and storage of WBC‐reduced RBC apheresis concentrates
Authors: Moog Rainer , Franck Valentine , Pierce Jennifer A. , Müller Norbert
Published: March 2003

BACKGROUND: Multicomponent apheresis procedures offer the possibility of collecting blood components that are standardized, as compared to those available with whole‐blood donations. A new separator program for the concurrent collection of RBCs, platelets, and plasma (Amicus, Baxter Healthcare) was evaluated.

STUDY DESIGN AND METHODS: Apheresis donors (n = 47) underwent concurrent collection of RBCs, platelets, and plasma by use of the single‐needle procedure of the Amicus blood cell separator. A standardized RBC volume (100% Hct) of 200 mL was targeted with either 1 or 2 platelet concentrate units, depending on the donor's predonation characteristics. After collection, the RBC component was sterilely connected to an RBC collection set (Amicus) to allow for the addition of 100 mL of saline‐adenine‐glucose‐mannitol preservative solution and WBC reduction at either ambient temperature or 4°C. The RBC units were subsequently stored at 2 to 6°C for 42 days, and the following in vitro measures were evaluated over the storage period: blood cell counts including Hct and total Hb, plasma Hb, potassium, pH, ATP, and 2,3 DPG.

RESULTS: Procedure time averaged 74 ± 9 minutes, and no adverse events were reported. The absolute RBC volume collected averaged 198 ± 11 mL with an average Hct value of 83 ± 2 percent. After filtration, the Hb content averaged 58.2 ± 2.4 g per unit and residual WBCs averaged 0.038 ± 0.015 × 106 per unit. Day 42 results showed that all units had on average more than 70‐percent ATP maintenance, and all of the units had less than 0.8 percent he‐molysis. All units had pH values higher than 6.5 on Day 42.

CONCLUSION: The concurrent multicomponent collection system (Amicus) can reliably collect a standardized RBC unit of good quality. In vitro testing of the RBCs collected and stored for 42 days met the Council of Europe criteria for transfusion.
Interactions of IgM ABO antibodies and complement with methoxy‐PEG‐modified human RBCs
Authors: Bradley Amanda J. , Test Samuel T. , Murad Kari L. , Mitsuyoshi Joyce , Scott Mark D.
Published: March 2003

BACKGROUND: RBCs modified with cyanuric chloride activated methoxy‐PEG (CmPEG; 5000 Da) are less immunogenic than untreated RBCs, and their use thus may reduce the risk of alloimmunization in chronically transfused patients.

STUDY DESIGN AND METHODS: To further examine the potential utility of CmPEG‐RBCs, the effects of derivatization on an arm of the immune system that plays an important role in transfusion rejection—the complement system—were determined.

RESULTS: When CmPEG‐RBCs were incubated in autologous or heterologous ABO‐matched serum, no classical or alternative pathway consumption was found, no C3a was generated, no cell‐bound C3b or C9 was detected, and no cell lysis occurred. Cell‐bound complement regulation was normal for CmPEG‐RBCs, as determined by acidified serum or reactive lysis assays. CmPEG‐RBCs differed from control RBCs only when incubated in ABO‐mismatched serum. In that case, CmPEG modification failed to protect against ABO antibody‐dependent complement‐mediated lysis. Indeed, cell lysis was actually enhanced at CmPEG concentrations >1.0 mM.

CONCLUSION: The enhanced lysis of CmPEG‐RBCs in ABO‐mismatched serum correlated with increased IgM binding and C3a generation and elevated C3b and C9 membrane deposition. While PEG modification effectively blocks non‐ABO antigens, these data show that ABO matching is still required. Once ABO‐matched, these modified RBCs retain great potential for the prevention of alloimmunization.
Implementation of a blood irradiation program at a community cancer center
Authors: Patton Gregory A. , Skowronski Michael G.
Published: March 2003

BACKGROUND: Blood component irradiation is an accepted method of preventing transfusion‐associated GVHD. Previous publications have largely focused on the technical aspects of the irradiation process itself, but relatively little attention has been paid to the details associated with the implementation of a blood irradiation program at the level of a community cancer center.

STUDY DESIGN AND METHODS: An observational study was performed, detailing the specific operational, documentation, and quality assurance measures employed in providing a blood component‐irradiation service within the institutional context of a community cancer center.

RESULTS: The Montgomery Cancer Center irradiated 589 units of blood components in 1998 and 1999 to provide a local blood bank with an alternative for procurement of irradiated blood components while complying with applicable quality assurance and regulatory requirements.

CONCLUSION: Blood component irradiation is within the scope of most well‐equipped and adequately staffed community cancer centers. Establishment of a blood component irradiation program requires scrupulous physics and dosimetry support, both to ensure the quality of the irradiated component and to satisfy governmental agency regulatory requirements.
Three‐Dimensional Mapping of Earliest Activation after Near‐Threshold Ventricular Defibrillation Shocks
Authors: CHATTIPAKORN NIPON , FOTUHI PARWIS C. , CHATTIPAKORN SIRIPORN C. , IDEKER RAYMOND E.
Published: March 2003

Three‐Dimensional Pattern of Earliest Postshock Activation. Introduction: Following shocks with a 50% defibrillation success (DFT50) delivered from electrodes at the right ventricular (RV) apex and superior vena cava (SVC), the earliest epicardial postshock activation always appears focally in the left ventricular (LV) apex for both successful and failed shocks. Because the heart is a three‐dimensional (3D) structure, questions remain whether this activation truly arises from a focus or the focal pattern represents epicardial breakthrough resulting from intramural reentry. To answer these questions, 3D electrical mapping was performed.

Methods and Results: In six pigs, 60 to 84 epoxy fiberglass needles (0.7‐mm‐diameter), each containing six electrodes 2 mm apart, were inserted into the LV with 3‐ to 5‐mm spacing around the apex and 5‐ to 10‐mm spacing near the base. Ten DFT50 shocks (RV→SVC, biphasic, 6/4 msec) were delivered after 10 seconds of fibrillation in each animal. The first five activations after each shock were mapped. Of 60 DFT50 shocks, 31 were successful, of which the first postshock cycle was a sinus beat in 13. In the other 18 successful shock episodes, the first postshock activation was detected

63 ± 16

msec after the shock, which was not significantly different from the

58 ± 23

msec postshock interval for the 29 failed shock episodes. In these 47 successful and failed shock episodes, the earliest postshock activation always arose focally from the LV apex. Its origin was in the subepicardium in

76%± 17%

, midmyocardium in

16%± 12%

, and subendocardium in

8%± 6%

of cases.

Conclusion: Following near‐DFT50 shocks, the first postshock cycles did not arise by macroreentry. Instead, they originated from a true focus or microreentry, most commonly near the epicardium.
Electrocardiographic Patterns of Superior Right Ventricular Outflow Tract Tachycardias: Distinguishing Septal and Free‐Wall Sites of Origin
Authors: DIXIT SANJAY , GERSTENFELD EDWARD P. , CALLANS DAVID J. , MARCHLINSKI FRANCIS E.
Published: March 2003

ECG Patterns of RVOT Tachycardias. Introduction: The superior right ventricular outflow tract (RVOT) septum and free wall are common locations of origin for outflow tract ventricular tachycardias (VT). We hypothesized that (1) unique ECG morphologies of pace maps from septal and free‐wall sites in the superior RVOT could be identified using magnetic electroanatomic mapping for accurate anatomical localization; and (2) this ECG information could help facilitate pace mapping and accurate VT localization.

Methods and Results: In 14 patients with structurally normal hearts who were undergoing ablation for outflow tract VT, a detailed magnetic electroanatomic map of RVOT was constructed in sinus rhythm, then pace mapping was performed from anterior, mid, and posterior sites along the septum and free wall of the superior RVOT. Pace maps were analyzed for ECG morphologies in limb leads and transition patterns in precordial leads. Monophasic R waves in inferior leads for septal sites were taller (

1.7 ± 0.4 mV

vs

1.1 ± 0.3 mV; P < 0.01

) and narrower (

158 ± 21 msec

vs

168 ± 15 msec; P < 0.01

) compared with free‐wall sites; lacked “notching” (28.6% vs 95.2%;

P < 0.05

); and showed early precordial transition (by lead V4; 78.6% vs 4.8%;

P < 0.05

). A positive R wave in lead I also distinguished posterior from anterior septal and free‐wall sites. Based on QRS morphology in limb leads and precordial transition pattern (early vs late), in a retrospective analysis, a blinded reviewer was able to accurately localize the site of origin of clinical arrhythmia (the successful ablation site on the magnetic electroanatomic map) in 25 of 28 patients (90%) with superior RVOT VT.

Conclusion: Pace maps in the superior RVOT region manifest site‐dependent ECG morphologies that can help in differentiating free‐wall from septal locations and posterior from anterior locations. Despite overlap in QRS amplitude and duration, in the majority of patients a combination of ECG features can serve as a useful template in predicting accurately the site of origin of clinical arrhythmias arising from this region.
The Canon of the History of Political Thought: Its Critique and a Proposed Alternative
Authors: Stuurman Siep
Published: March 2003

After a brief review of the origins and the nature of the received canon of the history of political thought, this article discusses the critiques that have been leveled at it over the past decades. Two major lines of critique are distinguished: 1. The democratic critique, focusing on the omission of “plebeian,” non‐Western, and female voices from the traditional canon, as well as the failure of the canon to discuss issues such as popular radicalism, patriarchal rule, and the politics of empire. 2. The methodological critique, in which the canon is deconstructed as an anachronistic, “Whiggish” enterprise, and its validity as history is questioned against the background of “history after the linguistic turn.” The article examines the consequences of both lines of criticism for some key concepts in the history of political thought, as well as for the coherence and the structure of the traditional canon. It calls attention to the paradox that, while virtually all elements of the canon have been subjected to incisive critique, the canon itself has so far survived relatively unscathed in the major textbooks and in the way the subject is taught in universities the world over. In the final section the question is raised what a new, reconstructed overall history of political thought might look like, and some preliminary suggestions are offered towards a revision of the canon that would satisfy both the democratic and the methodological critique.
Coherence and Ambiguity in History
Authors: Pollmann Thijs
Published: March 2003

This article is about the logic of the concept of “coherence” as used by historians to justify an argument. Despite its effectiveness in historical arguments, coherence is problematic for epistemologists and some theorists of history. The main purpose of this article is to present some insights that bear upon the logical status of coherence. As will be demonstrated, this will also shed some light on the allegedly dubious epistemological position of coherence. In general I will argue that, logically seen, coherence is a property of a set of related beliefs that makes it possible to justify a choice out of different factually justifiable interpretations. Coherence disambiguates vague or ambiguous observations. As words lose their vagueness or ambiguity in contexts, so do contexts disambiguate historical facts. My argument will be based on some relatively recent findings about the cognitive processes underlying vision and reading. Research in the field of text linguistics is used to show what kinds of relationships exist between historical representations that might be considered to cohere.
How to Be an Intentionalist
Authors: Bevir Mark
Published: March 2003

The general aim of this paper is to establish the plausibility of a postfoundational intentionalism. Its specific aim is to respond to criticisms of my work made by Vivienne Brown in a paper “On Some Problems with Weak Intentionalism for Intellectual History.” Postfoundationalism is often associated with a new textualism according to which there is no outside to the text. In contrast, I suggest that postfoundationalists can legitimate our postulating intentions, actions, and other historical objects outside of the text. They can do so by reference to, first, philosophical commitments to general classes of objects, and, second, inference to the best explanation with respect to particular objects belonging to such classes. This postfoundational intentionalism sets up a suitable context within which to address Brown's more specific questions.
Commitment to Company and Union: Evidence from Hong Kong
Authors: Snape Ed , Chan Andy W.
Published: March 2003

This article examines the pattern and antecedents of employee commitment to company and union in the Hong Kong context. Findings are consistent with those from the United States. In general, company and union commitment have different antecedents, although the perceived industrial relations climate is a common predictor. Dual commitment is in evidence. Union membership is a function of union commitment. The findings caution against attempts to explain the pattern of Hong Kong industrial relations purely in terms of culture.
Decision Making in Employment and Labor Arbitration
Authors: Bingham Lisa B. , Mesch Debra J.
Published: March 2003

This experimental study examined the labor and employment arbitration decisions of four groups of arbitrators: (1) employment arbitrators who resolve disputes involving nonunion employees, (2) labor arbitrators who arbitrate cases in which an employee is represented by a union, (3) arbitrators in the National Academy of Arbitrators (NAA), and (4) students as a comparison of nonarbitrator decision makers with experienced arbitrators. A 2 ×2 ×4 factorial design was used, crossing arbitrator group with discipline standard and sex of the grievant. Results indicate that employment artibrators reinstate the grievant significantly less frequently than other arbitrators; however, the findings also reveal that all arbitrators make more favorable decisions under a just‐cause standard than under the newer META standard of discipline.
Models of International Labor Standards
Authors: Block Richard N. , Roberts Karen , Ozeki Cynthia , Roomkin Myron J.
Published: March 2003

This article examines existing models of the regulation of international labor standards in the context of international trade. The article first focuses on conceptual and theoretical notions of the international regulation of labor standards. Four existing models of international labor regulations are then examined: the legislative model, the trade sanctions model, the multilateral enforcement model, and the voluntary standards model. The theoretical issues raised and the characteristics of the four models are then used to develop a suggested structure for the international regulation of labor standards in a world of free trade.
Disciplined Litigation, Vigilant Litigation, and Deformation: Dramatic Organization Change in Jehovah's Witnesses
Authors: Côté Pauline , Richardson James T.
Published: March 2003

Jehovah's Witnesses' long‐term development presents an interesting case of evolution in line with the “deformation thesis,” an attempt at explaining dramatic shifts in organizational forms, activities, and even beliefs in controversial religious minorities. Derived from resource mobilization tradition, this thesis assumes that radical transformations result from major defensive resource allocation mandated by negative reactions of societal institutions. This is especially the case with reference to the adoption by Jehovah's Witnesses, a millenarian group, of a “disciplined litigation”strategy in the 1940s, a pattern later to be incorporated in religious activities and beliefs of the organization. Today, disciplined litigation and its successor, “vigilant litigation,” seem legitimate ways to adapt to the prevailing religious climate and structure. As such, it can be conceived as a model for defensive moves taken by “younger” controversial religious minorities and reflects the enormous influence of the law and legal systems in shaping minority religions.
Parental Divorce and the “Switching” of Religious Identity
Authors: Lawton Leora E. , Bures Regina
Published: March 2003

This article examines the impact of parental divorce on the likelihood that an individual has changed their religious identify. Using data from the National Survey of Family and Households, we use a theoretical framework of family structure and community ties to test the hypothesis that religious mobility is more likely among children of divorce compared to those from intact families. Distinguishing between parental divorce in childhood and parental divorce in adulthood allows us to assess the impact of parental divorce on religious socialization. For individuals raised as either moderate Protestant, conservative Protestant or Catholic, parental divorce increases the likelihood of both switching to another religion and apostasy. The impact of divorce is particularly strong for Catholics and conservative Protestants, who are, in general, less likely to be religious mobile. These findings add religious disaffiliation to the set of likely sequelae of parental divorce. In addition, the results of the study highlight the need to consider the relationship between family structure and religious processes in a community context.
Self‐Selection, Church Attendance, and Local Civic Participation
Authors: McKenzie Brian D.
Published: March 2003

Prior research has shown that church attendance affects voting participation, but has a negative or no effect on more demanding forms of political participation. I argue that this differential for nonelectoral activity partially results from biases in how scholars conceptualize and analyze church attendance variables. To properly measure the influence of church attendance on nonelectoral participation, scholarship needs to account for self‐selection biases that hinder accurate analyses. Consistent with the literature, a selection model finds that once fundamentalism's motivating effect is considered, church attendance plays no role in a respondent's participation in local government meetings. The present work provides a partial explanation for why attendance has no effect on more demanding political activity. These findings demonstrate that scholarship should focus attention on prior factors that influence congregants' attendance decisions.
Do Inventories Matter in Dealership Markets? Evidence from the London Stock Exchange
Authors: Hansch Oliver , Naik Narayan Y. , Viswanathan S.
Published: March 2003

Using London Stock Exchange data, we test the central implication of the canonical model of Ho and Stoll (1983) that relative inventory differences determine dealer behavior. We find that relative inventories explain which dealers obtain large trades and show that movements between best ask, best bid, and straddle are highly correlated with both standardized and relative inventory changes. We show that the mean reversion in inventories is highly nonlinear and increasing in inventory levels. We show that a key determinant of variations in interdealer trading is inventories and that interdealer trading plays an important role in managing large inventory positions.
Capital Gains Taxation and Stock Market Activity: Evidence from IPOs
Authors: Reese William A.
Published: March 2003

Prior to the Tax Reform Act of 1986 (TRA '86), long‐term capital gains were taxed at a lower rate than short‐term gains, presenting investors with an opportunity to increase their after‐tax return by delaying the sale of appreciated assets until after they qualified for long‐term status and selling depreciated assets prior to long‐term qualification. Using a sample of Initial Public Offerings, I find that stocks that appreciated prior to long‐term qualification exhibit increased volume and decreased returns just after their qualification date, while stocks that depreciated prior to long‐term qualification exhibit these effects just prior to their qualification date.
How Are Derivatives Used? Evidence from the Mutual Fund Industry
Authors: Koski Jennifer Lynch , Pontiff Jeffrey
Published: March 2003

We investigate investment managers' use of derivatives by comparing return distributions for equity mutual funds that use and do not use derivatives. In contrast to public perception, derivative users have risk exposure and return performance that are similar to nonusers. We also analyze changes in fund risk in response to prior fund performance. Changes in risk are substantially less severe for funds using derivatives, consistent with the explanation that managers use derivatives to reduce the impact of performance on risk. We provide new evidence regarding the implications of cash flows and managerial gaming for the relation between performance and risk.
The Going‐Public Decision and the Development of Financial Markets
Authors: Subrahmanyam Avanidhar , Titman Sheridan
Published: March 2003

This paper explores the linkages between stock price efficiency, the choice between private and public financing, and the development of capital markets in emerging economies. Generally, the advantage of public financing is high if costly information is diverse and cheap to acquire, and if investors receive valuable information without cost. The value of public firms generally depends on public market size, which implies that there can be a positive externality associated with going public, so that an inferior equilibrium can exist where too few firms go public. The model is consistent with empirical observations on financial market development.
Liquidity and Liquidation: Evidence from Real Estate Investment Trusts
Authors: Brown David T.
Published: March 2003

This study provides evidence that highly leveraged owner‐managed properties liquidated assets during the commercial real estate decline of the late 1980s, and that this provided buying opportunities for better capitalized buyers. The analysis documents significant financial distress costs for highly leveraged firms during an industry‐wide downturn and shows that these costs are particularly large for owner‐managed firms.
Continuous‐Time Methods in Finance: A Review and an Assessment
Authors: Sundaresan Suresh M.
Published: March 2003

I survey and assess the development of continuous‐time methods in finance during the last 30 years. The subperiod 1969 to 1980 saw a dizzying pace of development with seminal ideas in derivatives securities pricing, term structure theory, asset pricing, and optimal consumption and portfolio choices. During the period 1981 to 1999 the theory has been extended and modified to better explain empirical regularities in various subfields of finance. This latter subperiod has seen significant progress in econometric theory, computational and estimation methods to test and implement continuous‐time models. Capital market frictions and bargaining issues are being increasingly incorporated in continuous‐time theory.
Corporate Reorganizations and Non‐Cash Auctions
Authors: Rhodes‐Kropf Matthew , Viswanathan S.
Published: March 2003

This paper extends the theory of non‐cash auctions by considering the revenue and efficiency of using different securities. Research on bankruptcy and privatization suggests using non‐cash auctions to increase cash‐constrained bidder participation. We examine this proposal and demonstrate that securities may lead to higher revenue. However, bidders pool unless bids include debt, which results in possible repossession by the seller. This suggests all‐equity outcomes are unlikely and explains the high debt of reorganized firms. Securities also inefficiently determine bidders' incentive contracts and the firm's capital structure. Therefore, we recommend a new cash auction for an incentive contract.
Price Discovery in Initial Public Offerings and the Role of the Lead Underwriter
Authors: Aggarwal Reena , Conroy Pat
Published: March 2003

We examine the price discovery process of initial public offerings (IPOs) using a unique dataset. The first quote entered by the lead underwriter in the five‐minute preopening window explains a large proportion of initial returns even for hot IPOs. Significant learning and price discovery continues to take place during these five minutes with hundreds of quotes being entered. The lead underwriter observes the quoting behavior of other market makers, particularly the wholesalers, and accordingly revises his own quotes. There is a strong positive relationship between initial returns and the time of day when trading starts in an IPO.
A First Look at the Accuracy of the CRSP Mutual Fund Database and a Comparison of the CRSP and Morningstar Mutual Fund Databases
Authors: Elton Edwin J. , Gruber Martin J. , Blake Christopher R.
Published: March 2003

This paper examines problems in the CRSP Survivor Bias Free U.S. Mutual Fund Database (CRSP, 1998) and compares returns contained in it to those in Morningstar. The CRSP database has an omission bias that has the same effects as survivorship bias. Although all mutual funds are listed in CRSP, return data is missing for many and the characteristics of these funds differ from the populations. The CRSP return data is biased upward and merger months are inaccurately recorded about half the time. Differences in returns in Morningstar and CRSP are a problem for older data and small funds.
Competition in a Repeated Spatial Auction Market with an Application to Timber Sales
Authors: Rusco Frank W. , Walls W. David
Published: March 2003

In this paper we develop a model of a repeated spatial auction market. The auction model contributes to the literature on spatial competition by considering the sale of goods in a market with spatial and temporal dimensions, and in which goods are sold by an auction institution instead of a posted‐price institution. In the Nash equilibrium of the spatial auction model, each bidder is found to have a dominance solvable strategy to bid below his net (of transportation costs) valuation for the first unit of the good because there is an option value to not winning, namely that the following units may be locationally preferred to the first unit. The equilibrium bidding strategies lead to the possibility of non–Pareto‐efficient outcomes. The auction model is applied to data from U.S. Forest Service timber sales.