bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance characteristics of the COBAS AmpliScreen HIV‐1 test, version 1.5, an assay designed for screening plasma mini‐pools
Authors: Yang Yanfeng , Lamendola Misty‐Hope , Mendoza Miguel , Xu Dick , Nguyen Minh , Yeh Sheria , Wu Yiqiao , Ku Joanne , Rosenstraus Maurice , Sun Rita 
Published: March 2003

BACKGROUND: The COBAS AmpliScreen HIV‐1 test, version 1.5 (v1.5) (Roche Molecular Systems), is designed for screening pools composed of samples from 24 individual units of blood or plasma. A specimen‐processing procedure (Multiprep) simultaneously concentrates and extracts HIV‐1, HCV, and HBV particles from plasma and incorporates an HIV‐1 internal control (IC) RNA. Processed samples are amplified by RT‐PCR using HIV‐1‐specific primers and detected by hybridization of the amplified products to HIV‐1‐ and IC‐specific oligonucleotide probes.STUDY DESIGN AND METHODS: Plasma samples containing known quantities of HIV‐1 were used to evaluate analytical sensitivity and precision and to validate a pool testing algorithm. Analytical specificity was evaluated by adding various viruses and bacteria to HIV‐1‐negative plasma. Seroconversion panels were tested to estimate the window‐period reduction achieved by RNA testing.RESULTS: The analytical sensitivity of the test (concentration that yields ≥95% positive results in a set of replicate tests) was 25 copies of HIV‐1 RNA per mL of pooled plasma. Representative strains from all HIV‐1 group M subtypes were reproducibly detected (>95% positive results) at concentrations of 20 to 200 viral particles per mL. The test did not cross‐react with a set of 31 viral and 5 bacterial isolates, and it yielded negative results on a panel of 500 blood samples from HIV‐1‐seronegative donors. Plasma samples containing abnormally high levels of Hb, albumin, triglycerides, or bilirubin did not interfere with the test. HIV‐1 RNA was detected 2 to 14 days before HIV‐1 antibody and 0 to 28 days before p24 antigen. The test specifically detected pools containing a single positive unit with 2400 HIV‐1 RNA copies per mL and correctly identified the positive unit.CONCLUSION: The COBAS AmpliScreen HIV‐1 test, v1.5, has sufficient sensitivity to detect a single infected unit containing 600 copies of HIV‐1 per mL in a pool with 23 uninfected units and should reduce the window period between infection and seroconversion by at least 2 to 14 days.
Immune reconstitution after autologous selectedperipheral blood progenitor cell transplantation:comparison of two CD34+ cell‐selection systems
Authors: Laurenti Luca , Sorà Federica , Piccirillo Nicola , Chiusolo Patrizia , Cicconi Silvia , Rutella Sergio , Serafini Riccardo , Garzia Maria Grazia , Leone Giuseppe , Sica Simona 
Published: March 2003

BACKGROUND: Selection of CD34+ PBPCs has been applied as a method of reducing graft contamination from neoplastic cells. This procedure seems to delay lymphocyte recovery, while myeloid engraftment is no different from that with unselected PBPC transplants.STUDY DESIGN AND METHODS: Lymphocyte recovery was studied in two groups of patients who underwent autologous CD34+ PBPC transplant with two different technologies (Ceprate SC, Cellpro [n = 17]; CliniMACS, Miltenyi Biotech [n = 13]). The median number of CD34+ cells transfused was 3.88 × 106 per kg and 3.32 × 106 per kg, respectively. Residual CD3 cells × 106 per kg were 4.97 and 0.58, respectively (p = 0.041). Residual CD19 cells × 106 per kg were 1.33 and 0.73, respectively (NS).RESULTS: No differences were found between the two groups in total lymphocyte recovery to >0.5 × 109 per L, which achieved a stable count by Day 30. During the study period, the CD4+ cell count remained below 0.2 × 109 per L, and the B‐cell subset showed a trend toward normalization. CD3/HLA‐DR+ and CD16/56 increased markedly in both groups by Day 30. An increase in CMV (13%) and adenovirus (17.4%) infection was found in both groups.CONCLUSION: Both CD34+ cell selection technologies used here determined an excellent CD34+ cell purity and an optimal depletion of T cells. The high rate of viral complications is probably due to the inability of residual T cells left from the CD34+ cell selection to generate, immediately after transplant, an adequate number of virus‐specific lymphocytes.
Absence of D alloimmunization in D– pediatric oncology patients receiving D‐incompatible single‐donor platelets
Authors: Molnar R. , Johnson R. , Sweat L.T. , Geiger T.L. 
Published: March 2003

BACKGROUND: Guidelines are lacking for prophylaxis against D alloimmunization after D‐incompatible platelet transfusion. A rational basis for the application of prophylaxis would be beneficial for institutions in which inventory constraints demand the administration of large numbers of D‐incompatible platelets. STUDY DESIGN AND METHODS: A retrospective analysis was performed of all D‐incompatible platelet transfusions administered at a pediatric research hospital over a 1.5‐year period. Patients exclusively received single‐donor WBC‐reduced platelets and did not receive RhIg immunoprophylaxis. Numbers, source, ABO type, duration of serologic follow‐up, and level of RBC contamination of D‐incompatible transfusions were analyzed. All positive D serologies in the institution over a 3.5‐year period were examined to determine cause and potential association with platelet transfusion. RESULTS: Thirty‐five patients not receiving bone marrow transplant and seven bone marrow transplant patients received 490 and 255 D‐incompatible transfusions, respectively, over 1.5 years. Patients had various diagnoses, predominantly malignancies. Seventy‐nine percent of D‐incompatible transfusions were ABO compatible. An estimated 2300 incompatible transfusions were performed over 3.5 years. No case of D alloimmunization was detected. CONCLUSIONS: D immunoprophylaxis is generally unnecessary in pediatric oncology patients receiving D‐incompatible, WBC‐reduced, single‐donor platelets not visibly contaminated by RBCs. Further studies to validate these observations in the pediatric population and to extend them to other population groups are warranted.
The rare Lu:–6 phenotype in Israel and the clinical significance of anti‐Lu6
Authors: Yahalom Vered , Ellis Martin H. , Poole Joyce , Rahimi‐Levene Naomi , Shinar Eilat , DaCosta Yehudit , Manny Noga , Levene Cyril 
Published: March 2003

BACKGROUND: Lu6 is a high‐incidence antigen of the Lutheran blood group. Examples of anti‐Lu6 are rare and are of uncertain clinical significance. CASE REPORT: Three patients were encountered in whom anti‐Lu6 was detected on pretransfusion screening. The patients were all Iranian Jews and were not known to be related. In vitro studies to ascertain the potential clinical significance of the antibody using the monocyte monolayer assay (MMA) were negative in two patients. The third patient received a two‐unit transfusion of incompatible Lu6 RBCs with no signs of hemolysis. However, after the transfusion, the MMA and a chemiluminescence test were positive, whereas a chromium survival study was normal. Thus, the antibody may have changed in its clinical significance. CONCLUSION: Although anti‐Lu6 does not appear to be a clinically significant RBC antibody in all circumstances, transfusion of Lu6 RBCs in patients with anti‐Lu6 should be performed cautiously.
Preparation of FFP as a by‐product of plateletpheresis
Authors: Zingsem Jürgen , Weisbach Volker , Zimmermann Robert , Glaser Anke , Bunkens Helena , Eckstein Reinhold 
Published: March 2003

BACKGROUND: To reduce the production costs of single‐donor platelets (SDPs), a study was conducted to investigate whether plasma collected as a by‐product of plateletpheresis satisfies the quality requirements for FFP without impairing the quality of the SDP component. STUDY DESIGN AND METHODS: Ninety‐two donors with platelet (PLT) counts <270 × 109 per L underwent plateletpheresis using an automated cell separator (Spectra Apheresis System with the Leukoreduction System [LRS], Gambro BCT, Lakewood, CO). The machine was programmed to collect 3 × 1011 PLTs in 250 mL of plasma with an additional unit of 350 mL of plasma or 3 × 1011 PLTs in 250 mL of plasma without additional plasma in 10 procedures. FV and FVIII and residual RBCs, WBCs, and PLTs in the plasma were measured for quality control. RESULTS: FV was 0.87 ± 0.18 IU per mL, and FVIII was 1.32 ± 0.48 IU per mL in the plasma components (n = 41). The recovery was 94.1 ± 5.5 percent for FV and 102.2 ± 9.5 percent for FVIII when compared with the donors' predonation values. Residual cells were 0.002 ± 0.009 × 109 RBCs per L (n = 30), 12 ± 6 × 109 PLTs per L (n = 30), and 0.32 ± 0.37 × 106 WBCs per L (n = 92). CONCLUSIONS: Using the automated cell separator and special software, it is possible to collect plasma as a by‐product of plateletpheresis that meets the properties requested for FFP without impairing the quality of the SDP components. The content of clotting factors is within the requested range for FFP. Residual cell counts are within all European and U.S. specifications for FFP, and the WBC content even satisfies the criteria for WBC‐reduced blood components. The collection of FFP as a by‐product does not cause any additional costs and thus helps to reduce the costs in preparing blood components.
Ex vivo expansion of long‐term culture initiating marrow cells by IL‐10, SCF, and IL‐3
Authors: Keil Felix , Elahi Fariborz , Greinix Hildegard T. , Fritsch Gerhard , Louda Norbert , Petzer Andreas ;L. , Prinz Erika , Wagner Thomas , Kalhs Peter , Lechner Klaus , Geissler Klaus 
Published: March 2003

BACKGROUND: Ex vivo expansion of progentior cells may shorten hematopoietic regeneration after myeloablative chemoradiotherapy, increase target cells for gene therapy, and improve purging of progenitor cell components. STUDY DESIGN AND METHODS: Marrow cells were incubated for 1 week in suspension culture with and without IL‐10, IL‐3, and SCF. As long‐term culture initiating cells (LTC‐ICs) represent early hematopoietic progenitors in vitro, these cells were quantified at initiation and after a 1‐week culture period in a limiting dilution assays. Additionally, immunophenotyping of cells before and after culture was performed. RESULTS: In six experiments, marrow cells cultured for 1 week with IL‐10, IL‐3, and SCF showed a significant increase (almost doubling) in LTC‐ICs as compared with marrow cells before expansion. Additionally, an increased proliferative capacity of LTC‐ICs was achieved with a sevenfold increase of committed colony‐forming cells and a 10‐fold proliferation of high proliferative potential colony‐forming cells. Immunophenotyping revealed a sevenfold increase of CD34+ CD45 RA– cells in IL‐10‐, IL‐3‐, SCF‐stimulated suspension cultures. In unstimulated cultures, no LTC‐ICs were maintained after 1 week. CONCLUSION: Expansion of LTC‐ICs by IL‐10, IL‐3, and SCF has not been shown so far. This in vitro model allows expansion of LTC‐IC if compared with the input of progenitor cells without extensive progenitor cell manipulation. This should be an attractive model for in vitro purging, gene transfer, or expansion of progenitor cells to allow rapid engraftment after myeloablative chemotherapy.
Semiautomated data analysis of flow cytometric estimation of fetomaternal hemorrhage in D− women
Authors: Greiss M.A. , Armstrong‐Fisher S.S. , Perera W.S. , Brown P.M. , Urbaniak S.J. 
Published: March 2003

BACKGROUND : Accurate and reliable measurement of the volume of fetal D+ cells in D− women is required for adequate anti‐D prophylaxis. A semiautomated flow cytometry assay based on a standardized calibration curve that was created with simulated fetomaternal hemorrhage (FMH) mixtures was developed. STUDY DESIGN AND METHODS : A calibration range of 0.083‐ to 2‐percent D+ cells in the D−RBC mixtures (2‐44 mL calculated FMH) was analyzed by use of a flow cytometer (XL‐MCL, Coulter Electronics Ltd). Linear regression analysis of the calibration curve data with computer software (Excel, Microsoft) allowed semiautomated determination of the FMH volume. To optimize the assay, fresh versus frozen and thawed RBCs, RBCs from adults who are heterozygous for D or cord RBCs, and indirect‐ or direct‐labeling techniques were evaluated by use of MoAbs. RESULTS
: Fresh RBCs from adults heterozygous for D were chosen for routine use, although equivalent calibration curves were obtained with all cells tested (n = 12 calibration assays; r

2
= 0.999; mean SD, 14%). A monoclonal anti‐D reagent (Therad 10, Diagnostics Scotland) worked well in both indirect‐(anti‐IgG F(ab)‐FITC) and direct‐(anti‐D‐FITC) labeling methods compared to the use of BRAD‐3 FITC. In routine practice, the FMH volumes obtained were mainly lower than those obtained in the Kleihauer Betke test when there was less than 4 mL of FMH. CONCLUSION : Semiautomated data acquisition and calibration curve analysis represents a further step toward standardization of flow cytometry for accurate FMH quantification and facilitates evaluation and control of day‐to‐day variations between laboratories, flow cytometers, and operators.
Residual risk of transfusion‐transmitted HCV and HIV infections by antibody‐screened blood in Italy
Authors: Velati Claudio , Romanò Luisa , Baruffi Lorella , Pappalettera Marco , Carreri Vittorio , Zanetti Alessandro R. 
Published: March 2003

BACKGROUND: This study was designed to assess the risk of transmitting HCV and HIV by transfusion of antibody‐screened blood and to estimate the additional reduction in risk that may be achieved through the implementation of direct viral detection assays in Italy.STUDY DESIGN AND METHODS: Clinical and laboratory data of 2,411,800 blood donations collected from repeat volunteer donors from 1996 through 2000 were analyzed. The risk of transmitting HCV or HIV from screened blood donated during the window period was estimated using a mathematical model.RESULTS: The residual risk of donating antibody‐ negative infectious blood was estimated at 1 in 127,000 donations for HCV and 1 in 435,000 for HIV. The use of NAT should further reduce such risk by 83 percent for HCV and 50 percent for HIV.CONCLUSION: The residual risk of HCV or HIV transmission through screened blood is currently very small in Italy. The implementation of direct viral detection assays can further improve the safety of blood supply.
Hypotensive reaction during staphylococcal protein A column therapy in a patient with anomalous degradation of bradykinin and Des‐Arg9‐bradykinin after contact activation
Authors: Molinaro Giuseppe , Adam Albert , Lepage Yves , Hammerschmidt Dale , Koenigbauer Ulrike , Eastlund Ted 
Published: March 2003

BACKGROUND: Hypotensive reactions have occurred in patients taking angiotensin converting enzyme (ACE) inhibitors after infusion of blood previously in contact with negatively charged surfaces capable of generating kinins, which accumulate when ACE, a kininase, is inhibited. A patient with anomalous bradykinin (BK) metabolism who experienced hypotension during extracorporeal staphylococcal protein A (SPA) therapy while on an ACE inhibitor was studied. CASE REPORT: A patient with mitomycin‐associated hemolytic‐uremic syndrome received SPA treatments after her ACE inhibitor, lisinopril, was held. Lisinopril was restarted before her 18th SPA treatment, and immediately after return of treated plasma she developed facial redness and hypotension, which resolved after the return stopped and recurred when restarted. To study formation and degradation of kinins, exposed her plasma to glass beads. We found a normal kinin formation rate but an abnormal degradation and accumulation of Des‐Arg9‐BK. The kinin degradation enzymes ACE, aminopeptidase P (APP), and carboxypeptidase N (CPN) were measured while on an ACE inhibitor, showing absence of ACE activity, low APP, but normal CPN. CONCLUSION: This patient's vasodilation and hypotension during SPA therapy was associated with a pre‐ existing anomaly of BK metabolism. Her ACE inhibitor shifted degradation toward Des‐Arg9‐BK formation, and her low APP was associated with a prolonged t50 and accumulation of the vasoactive Des‐Arg9‐BK.
Assessing the accuracy of three viral risk models in predicting the outcome of implementing HIV and HCV NAT donor screening in Australia and the implications for future HBV NAT
Authors: Seed Clive R. , Cheng Anthea , Ismay Susan L. , Bolton Wayne V. , Kiely Philip , Cobain Trevor J. , Keller Anthony J. ,   Virology Subcommittee of the National Donor and Product Safety Committee, Australian Red Cross Blood Service
Published: March 2003

BACKGROUND : Risk modeling is now the most practical method of estimating the residual risk of viral transmission in developed countries. One method of assessing the accuracy of a risk model is to measure the observed against the predicted outcome after implementing a new screening method. The primary objective of this paper is to assess the accuracy of three published models in predicting the impact of implementing HIV and HCV NAT in Australia. STUDY DESIGN AND METHODS : Viral screening data on Australian donors for 2000 and 2001 were retrospectively analyzed. The data were applied to the three models to estimate the risk of transmission and predicted NAT yield for HIV, HCV, and HBV. RESULTS : The median risk estimates for the three models were 1 in 3,415,000 for HIV NAT, 1 in 911,000 for HCV NAT, and 1 in 483,000 for HBsAg. The predicted NAT yield for the three models ranged from 0.17 to 0.30 per million donations for HIV, 1.20 to 5.55 for HCV, and 0.47 to 1.01 for HBV. The observed NAT yield was not significantly different from the expected yield with any of the three models for either HIV or HCV. CONCLUSIONS : First, the residual risk in Australian donors is small in comparison with other transfusion complications and comparable to or lower than the risk in US and European nonremunerated donors. Second, mathematical risk modeling has sufficient precision to be used as a predictive tool for risk‐benefit assessments of novel screening procedures. Finally, in relation to the case for implementing HBV NAT and/or anti‐HBc in Australia, we conclude that at present, there is inadequate information about our donor population to perform an evidence‐based risk‐benefit analysis.
Body Surface Laplacian Electrocardiogram of Ventricular Depolarization in Normal Human Subjects
Authors: LI GUANGLIN , LIAN JIE , SALLA PRATHYUSHA , CHENG JIA , RAMACHANDRA INDIRESHA , SHAH PARTHIV , AVITALL BOAZ , HE BIN 
Published: March 2003

Body Surface Laplacian Map. Introduction: The body surface Laplacian electrocardiogram (ECG) mapping provides a noninvasive means for spatiotemporal mapping of cardiac electrical events. The aim of the present study was to explore the relationship between the Laplacian ECG and the underlying cardiac activities during ventricular depolarization in healthy human subjects.
Methods and Results: A 95‐channel body surface potential ECG was recorded over the anterolateral chest from 11 healthy male subjects. The surface Laplacian (SL) ECG was estimated from the recorded potentials during QRS complex by means of a novel spline SL estimator, as well as by the conventional 5‐point SL estimator for comparison purpose. A simulation study was also conducted using a realistic geometry heart‐torso model in an attempt to qualitatively interpret the experimental results. For all subjects, more spatial details were observed in the SL ECG maps compared with the potential ECG maps, with spline SL more robust against noise than the 5‐point SL. In total, three positive activities (denoted as P1, P2, P3) and four negative activities (denoted as N1, N2, N3, N4) in the spline SL ECG maps were observed during ventricular depolarization. Initial localized P1 and N1 activities were observed in 11 and 8 subjects, respectively. Then, the initial P1 was divided into three positive activities (P1, P2, P3) in 9 subjects. After the appearance of multiple positive activities, three negative activities (N2, N3, N4) appeared in 11, 8, and 9 subjects, respectively. Similar findings were obtained in the computer simulation study.
Conclusion: The present study demonstrates that the SL ECG provides more spatial details than the potential ECG, and multiple simultaneously active ventricular activities could be revealed in the SL ECG maps. The results suggest that the SL ECG may provide an alternative for noninvasive mapping of cardiac electrical activity.
Danto on Representation, Identity, and Indiscernibles
Authors: Ankersmit F. R. 
Published: March 2003

Arthur Danto has made important contributions to both aesthetics and philosophy of history. Furthermore, as I shall try to show in this essay, his aesthetics is of great relevance to his philosophy of history, while his philosophy of history is of no less interest for his aesthetics.By focusing on the notions of representation, identity, and the identity of indiscernibles we shall discover how fruitful this cooperation of aesthetics and philosophy of history may be. Crucial to all historical writing and, hence, to all philosophy of history, is the notion of identity through time and change. How could the historian write the history of x if x cannot be said to remain the same in the course of its history? It will become clear that aesthetics will provide us with a satisfactory solution for the problem, for the aestheticist notion of representation will enable us to define the notion of identity that the historian needs.Nevertheless, a certain friction can be observed between Danto's aesthetics and his philosophy of history. At the end of this essay I hope to show that Danto's philosophy of history will be our best guide to dealing adequately with this friction.
Agency Costs, Risk Management, and Capital Structure
Authors: Leland Hayne E. 
Published: March 2003

ABSTRACTThe joint determination of capital structure and investment risk is examined. Optimal capital structure reflects both the tax advantages of debt less default costs (Modigliani and Miller (1958, 1963)), and the agency costs resulting from asset substitution (Jensen and Meckling (1976)). Agency costs restrict leverage and debt maturity and increase yield spreads, but their importance is small for the range of environments considered.Risk management is also examined. Hedging permits greater leverage. Even when a firm cannot precommit to hedging, it will still do so. Surprisingly, hedging benefits often are greater when agency costs are low.
Corporate Ownership Around the World
Authors: La Porta Rafael , Lopez‐De‐Silanes Florencio , Shleifer Andrei 
Published: March 2003

ABSTRACTWe use data on ownership structures of large corporations in 27 wealthy economies to identify the ultimate controlling shareholders of these firms. We find that, except in economies with very good shareholder protection, relatively few of these firms are widely held, in contrast to Berle and Means's image of ownership of the modern corporation. Rather, these firms are typically controlled by families or the State. Equity control by financial institutions is far less common. The controlling shareholders typically have power over firms significantly in excess of their cash flow rights, primarily through the use of pyramids and participation in management.
Learning about Predictability: The Effects of Parameter Uncertainty on Dynamic Asset Allocation
Authors: Xia Yihong 
Published: March 2003

ABSTRACTThis paper examines the effects of uncertainty about the stock return predictability on optimal dynamic portfolio choice in a continuous time setting for a longhorizon investor. Uncertainty about the predictive relation affects the optimal portfolio choice through dynamic learning, and leads to a state‐dependent relation between the optimal portfolio choice and the investment horizon. There is substantial market timing in the optimal hedge demands, which is caused by stochastic covariance between stock return and dynamic learning. The opportunity cost of ignoring predictability or learning is found to be quite substantial.