bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitation of residual WBCs in filtered blood components by high‐throughput, real‐time kinetic PCR
Authors: Lee Tzong‐Hae , Wen Li , Chrebtow Vera , Higuchi Russell , Watson Robert M. , Sninsky John J. , Busch Michael P. 
Published: March 2003

BACKGROUND: The effort to eliminate transfusion complications associated with WBCs has led to the widespread use of filters able to reduce WBC concentrations to ≤0.1 WBC per μL blood. This has necessitated sensitive QC methods to quantitate residual WBCs in filtered units. One fast, effective method is DNA amplification using real‐time kinetic PCR (kPCR). STUDY DESIGN AND METHODS: Two methods of preparation of standards were compared and used for the optimization of quantitative kPCR. The first involved spiking genomic DNA cell lysate into a diluent, followed by a series of 1 in 10 dilutions. The second involved spiking serial 1 in 10 dilutions of WBCs into twice‐filtered fresh whole blood. Two hundred fifty filtered frozen whole‐blood samples were amplified in duplicate to show the kPCR assay's reproducibility. Another 359 filtered frozen whole blood samples were used to compare data from kPCR with data from a standard PCR protocol using 32P‐labeled probe and autoradiography. All specimens were amplified for conserved HLA DQα sequences. RESULTS: Standards prepared by both methods gave reproducible and equivalent results. Quantitation of standards representing a dynamic range of 8 × 100 to 8 × 105 WBCs per mL, yielded standard deviations ranging from 0.59 cycle to 1.04 cycles (a one‐cycle increase is equivalent to a twofold increase in WBC concentration). The scatter graph of the 250 samples tested in duplicate by kPCR generated a slope of 1.0122 and an R2 value of 0.9265. The comparison of kPCR and 32P‐probe hybridization results on 359 clinical samples gave a scatter‐graph slope of 0.9428 and an R2 value of 0.8718, indicating excellent agreement of the methods over a 4‐log dynamic range. CONCLUSION: kPCR is a high‐throughput, sensitive assay that could prove useful in routine quality assurance of the WBC reduction process.
Signs and symptoms associated with the transfusion of WBC‐reduced RBCs and non‐WBC‐reduced RBCs in patients with anemia and HIV infection: results from the Viral Activation Transfusion Study
Authors: Lane Thomas A. , Gernsheimer Terry , Mohandas Kala , Assmann Susan F. 
Published: March 2003

BACKGROUND: RBC transfusion is associated with fever and other reactions in some patients. The Viral Activation Transfusion Study randomly assigned patients to receive either unmodified or WBC‐reduced RBCs and thus offered an opportunity to assess the effect of WBC‐reduced RBCs on the incidence of transfusion reactions prospectively. STUDY DESIGN AND METHODS: This prospective, randomized, double‐blind, multicenter study compared prestorage WBC‐reduced RBCs to unmodified RBCs in HIV‐infected, CMV‐seropositive, and transfusion‐naive persons who required transfusions for anemia. Primary endpoints were survival and change in the plasma HIV RNA level at 7 days after transfusion. The incidence of transfusion reactions was prospectively evaluated. RESULTS: The two groups had similar baseline characteristics and study endpoints; 3864 RBC units (median storage age, 9 days) were administered to 531 patients during 1745 transfusions. The most frequent signs reported were elevated temperature and hypotension. Subjects who reported fever within the week prior to transfusion were more likely to have an elevation in temperature associated with transfusion. The administration of RBCs that were less than 10 days old was associated with a marginal increase in the incidence of transfusion‐associated temperature elevation among recipients of unmodified RBCs, but not among recipients of WBC‐reduced RBCs. Caregivers reported fewer instances of both elevated temperature and hypotension than were identified by review of transfusion records. CONCLUSIONS: The incidence of elevated temperature and hypotension associated with transfusion in this population was unexpectedly high. Use of WBC‐reduced RBCs had no effect on the overall rates of elevated temperature or hypotension associated with transfusion of RBCs. The occurrence of a pre‐existing fever was associated with a higher frequency of transfusion‐associated elevated temperature.
Potential value of Plasmodium falciparum‐associated antigen and antibody detection for screening of blood donors to prevent transfusion‐transmitted malaria
Authors: Silvie Olivier , Thellier Marc , Rosenheim Michel , Datry Annick , Lavigne Patricia , Danis Martin , Mazier Dominique 
Published: March 2003

BACKGROUND: Malaria antibody detection is a valuable tool in the prevention of transfusion‐transmitted malaria in countries with a high proportion of donors with travel exposure to malaria. The immunofluorescent antibody test (IFAT) is still the reference method, but it is not suitable for screening of blood donors. ELISA would be an interesting alternative to the IFAT, but it lacks sensitivity. STUDY DESIGN AND METHODS: To evaluate the potential value of a combined screening strategy based on malaria antigen and antibody detection, plasma samples from 203 patients infected with Plasmodium falciparum were tested with an ELISA for the detection of malaria antibodies (Malaria IgG CELISA, Cellabs) and a P. falciparum histidine‐rich protein‐2 kit (Malaria P.f., ICT Diagnostics) for the detection of malaria antigens. RESULTS: Among patients with positive IFAT results, CELISA had a sensitivity of 71 percent, whereas the combined screening tests (CELISA and Malaria P.f.) had a sensitivity of 88 percent (p < 0.001). Sequential samples from 50 patients were tested. The combined screening tests shortened the detection of seroconversion from 11.4 ± 1.6 to 5.3 ± 1.1 days (p < 0.001). CONCLUSION: Combined malaria antigen and antibody detection, with methods compatible with mass screening, may constitute an attractive alternative to the IFAT for blood donor screening.
Reduced frequency of blood donors with false‐positive HIV‐1 and ‐2 antibody EIA reactivity after elution of low‐affinity nonspecific natural antibodies
Authors: Bouillon Marlene , Aubin Éric , Roberge Chantal , Bazin Renée , Lemieux Réal 
Published: March 2003

BACKGROUND : The detection by EIA of antibodies (Abs) specific to HIV antigens in the serum of blood donors is important for transfusion safety. A small but significant number of donor sera (0.1‐0.3%) yield false‐positive results in EIA, and these donors must be permanently deferred from the blood donor list, causing operational and public relations problems. STUDY DESIGN AND METHODS : False‐positive EIA reactions could be caused by the binding of low‐affinity natural polyreactive Abs, which could be eluted by treatment with a chaotropic agent such as thiocyanate (SCN). The effect of the SCN elution on EIA specificity was studied using tetanus toxoid and HIV Abs. RESULTS : SCN elution preferentially reduced the binding of nonspecific Abs. Testing of 235 seronegative samples in HIV‐1 and ‐2 EIA showed that SCN elution reduced the mean and dispersion of OD values obtained. In addition, SCN elution abolished the false‐ positive reactivity in HIV‐1 and ‐2 EIA of 69 percent (299/435) of the repeatedly reactive specimens tested without impact on the reactivity of HIV‐seropositive specimens. CONCLUSION : The SCN elution step increased the specificity of HIV‐1 and ‐2 EIA and could facilitate the re‐entry of previously deferred donors.
PCR with sequence‐specific primer‐based simultaneous genotyping of human platelet antigen‐1 to ‐13w
Authors: Lyou Jau‐Yi , Chen Ying‐Ju , Hu Hui‐Yu , Lin Jeong‐Shi , Tzeng Cheng‐Hwai 
Published: March 2003

BACKGROUND : Accurate human platelet antigen (HPA) typing is important for patients with diagnosis of alloimmune thrombocytopenic syndromes and provision of HPA‐matched blood components for these patients. STUDY DESIGN AND METHODS : Thirteen sequence‐specific primers (SSPs) designed on the basis of known published polymorphisms for HPA‐1 to HPA‐13w, respectively, were employed for simultaneous HPA genotyping. All PCR amplifications were carried out with identical cycling conditions in 96‐well plates containing primer mixtures. A total of 300 blood samples from unrelated volunteer donors in Taiwan were included in the study. RESULTS
: All primers had specific amplification products. The typing results were available within 4 hours each time for up to four blood samples tested. Among the 13 HPAs, HPA‐3 had the greatest heterozygosity with a gene frequency of 0.3267, 0.4967, and 0.1767 for
HPA‐3a/HPA‐3a, HPA‐3a/HPA‐3b,
and
HPA‐3b/HPA3‐b,
respectively. For the remaining 12 HPAs, the predominance of
a/a
homozygosity was noted for HPA‐1, ‐2, ‐4, ‐5, and ‐6, with a frequency ranging from 0.9200 to 0.9967. The frequency of
a/a
homozygosity was 1.0000 for HPA‐7w to ‐13w, except for HPA‐10w, for which one case was observed to be
HPA‐10aw/HPA‐10bw
heterozygous. Excluding HPA‐3,
b/b
homozygosity was noted in only one case (
HPA‐6b/HPA‐6b ). The prevalence rates of HPA‐1 to ‐13w in this study were consistent with previous reports using different methods. CONCLUSION : An extended, streamlined PCR‐SSP protocol for simultaneous genotyping of HPA‐1 to HPA‐13w was established. This allows fast and reliable diagnosis of alloimmune thrombocytopenia, and is readily applicable to large‐scale genetic population studies.
PEN110 treatment functionally inactivates the PBMNCs present in RBC units: comparison to the effects of exposure to gamma irradiation
Authors: Fast Loren D. , DiLeone Gilbert , Edson Clark M. , Purmal Andrei 
Published: March 2003

BACKGROUND : The presence of WBCs in blood components is the major factor influencing the immunologic consequences of transfusion. Attempts to ameliorate these responses have used WBC reduction or inactivation by ionizing radiation. PEN110 (Inactine, V. I. Technologies) is a chemical that inhibits the replication of infectious pathogens by modifying their nucleic acids. These experiments compared effects of PEN110 treatment or gamma irradiation on WBC function. STUDY DESIGN AND METHODS : Aliquots of non‐WBC‐reduced RBC units were treated with PEN110 or gamma irradiation with appropriate controls, and PBMNCs from these units were tested with in vitro assays. The assays included immunophenotyping, activating T cells with phorbol ester, proliferation of cells in response to mitogens or allogeneic cells, and determining the ability of cells to stimulate proliferative responses and to produce IL‐8. DNA fragmentation following PEN110 treatment was examined by PCR and terminal deoxynucleotidyl transferase‐mediated deoxyuridine triphosphate‐biotin nick end labeling assays. RESULTS : Treatment of non‐WBC‐reduced RBC units with PEN110 functionally inactivated WBC in all in vitro assays used. In contrast, while gamma irradiation inhibited proliferation of the WBCs, it did not or only partially inhibited the ability of WBC to function in the other assays. PEN110, but not gamma irradiation, rapidly induced fragmentation of cellular DNA. CONCLUSION : Because PEN110 was as effective as gamma irradiation at inhibiting WBC proliferation, PEN110 treatment could potentially be used to prevent the development of GVHD following transfusion.
Autologous transfusion recovery of WBC‐reduced high‐concentration platelet concentrates
Authors: Dumont Larry J. , Beddard Rachel , Whitley Pamela , Johnson Adrienne , McNeil Deanna , Sawyer Sherrie , Elfath M. Dean 
Published: March 2003

BACKGROUND : This study evaluates the recovery and survival of high‐concentration platelets (HCPs) compared to standard apheresis platelets (APCs) in a double‐label autologous human system. METHODS
: Nine HCP units paired with APC units were stored, labeled with either
51
Cr and
111 In, and returned, and recovery and survival were determined. Standard in vitro platelet biochemical and functional parameters were monitored over the storage period and evaluated in a secondary analysis. RESULTS
: Three each HCP units containing more than 2.2 × 10
11
, 1.5 × 10
11
to 2.1 × 10
11
, and 0.8 × 10
11
to 1.1 × 10
11
platelets in 59.4 ± 2.5 mL were stored for 1, 2, or 5 days, respectively, and simultaneously with matched APC units (3.8 × 10
11 platelets, 282 mL). Recoveries were 72.3 ± 8.6, 60.8 ± 14.6, and 52.5 ± 6.7 percent for HCPs, respectively; and 59.4 ± 6.4 percent for APCs (p = 0.37). HCP survivals were 202.0 ± 14.9, 204.9 ± 10.2, and 162.6 ± 17.0 hours; APC survivals were 155.4 ± 20.3 hours (p = 0.001). Secondary analysis with P‐selectin added as a predictor in the model resulted in significant difference in recoveries for Day 1 HCPs versus Day 5 APCs (p = 0.024) with no difference shown for HCPs on Days 2 or 5 versus APCs. No significant difference was found in survival (p = 0.16). CONCLUSION
: HCPs may be stored 24 hours for high yield, 48 hours for intermediate yield, and up to 5 days for yields less than 1.6 × 10
11 platelets per bag with equivalent to superior recovery and survival of platelets in the autologous transfusion model compared to APCs.
RBC‐associated IgG in patients with visceral leishmaniasis (kala‐azar): a prospective analysis
Authors: Vilela Rosana B. , Bordin José O. , Chiba Akemi K. , Castelo Adauto , Barbosa Maria C. 
Published: March 2003

BACKGROUND: Despite the fact that anemia is one of the most striking clinical features of visceral leishmaniasis (kala‐azar), the factors involved in its pathogenesis are not fully understood. Although the cause of the anemia seen in these patients is often multifactorial, sequestration and destruction of the RBCs in the enlarged spleen, immune mechanisms, and alterations in RBC membrane permeability have been implicated. STUDY DESIGN AND METHODS: To investigate whether RBCs of patients with kala‐azar were coated with IgG, blood samples of 67 patients were tested, prospectively, before (Day 1), during (Day 30), and after (Day 90) antimonial therapy, to examine the presence of RBC‐associated IgG, circulating immune complexes (CICs), and rheumatoid factor (RF). RESULTS: The prevalence of a positive DAT on Day 1 was significantly greater than the prevalence of a positive DAT performed on Day 30 and on Day 90 (32.8 vs. 4 vs. 0%, p < 0.001). With an enzyme‐linked antiglobulin test (ELAT) to measure the number of IgG molecules per RBC more accurately, it was found that the amount of IgG molecules per RBC was increased (mean, 298 molecules of IgG per RBC) in the group of patients with kala‐azar tested before antimonial therapy, but was considered normal (<50 molecules of IgG per RBC) in all patients tested 90 days after treatment. The prevalence of a positive eluate test was low (15.0%) in DAT (anti‐IgG)‐positive patients and the positivity of DATs and ELATs correlated with the presence of either RF or CICs, respectively. CONCLUSIONS: These data suggest that a nonspecific adsorption of CICs on the RBC surface is probably the most important factor involved in the increased amount of RBC‐associated IgG in patients with untreated visceral leishmaniasis; however, further prospective studies are required to establish the exact role of the RBC‐associated antibodies, CICs, and RF as contributing factors of the anemia seen in these patients.
IgG1 and IgG3 anti‐D in maternal serum and on the RBCs of infants suffering from HDN: relationship with the severity of the disease
Authors: Lambin Patrick , Debbia Martine , Puillandre Philippe , Brossard Yves 
Published: March 2003

BACKGROUND : Anti‐D IgG antibodies that are responsible for severe cases of HDN belong chiefly to IgG1 and IgG3 subclasses. The relationship between the concentrations of IgG1 anti‐D and IgG3 anti‐D in maternal serum and the amount bound to the surface of infants' RBCs is not known. In addition, the contribution of the two subclasses to the severity of HDN is not well established. STUDY DESIGN AND METHODS : Blood samples from 40 infants suffering from severe forms of HDN due to anti‐D were collected before transfusion together with sera from their respective mother. The amount of total anti‐D IgG as well as IgG1 anti‐D and IgG3 anti‐D on infants' RBCs and the concentration in maternal sera were determined by ELISA. RESULTS : The median percentages of IgG1 anti‐D and of IgG3 anti‐D in maternal sera were 90 and 10 percent, respectively, whereas on infants' RBCs they were 97 and 3 percent, respectively. The differences between maternal and infantile percentages were significant (p < 0.001). IgG1 and IgG3 anti‐D bound to infants' RBCs increased concomitantly with the concentration of IgG1 and IgG3 anti‐D in maternal sera. The severity of HDN correlated positively with the concentration of IgG1 anti‐D in maternal sera, but negatively with the amount of IgG3 anti‐D bound to infants' RBCs. In addition, the existence of a high proportion of IgG3 anti‐D in maternal serum was associated with a delayed risk of fetal anemia. CONCLUSION : The proportion of IgG3 anti‐D relative to the total anti‐D IgG on infants' RBCs is only one‐ third of the proportion present in maternal serum. The study of the correlations between the amount of IgG1 anti‐D and IgG3 anti‐D and the severity of HDN suggests that IgG1 anti‐D are more important than IgG3 anti‐D in the pathogenesis of fetal anemia.
Investigations into the role of anti‐HLA class II antibodies in TRALI
Authors: Kao Grace S. , Wood Isabelle G. , Dorfman David M. , Milford Edgar L. , Benjamin Richard J. 
Published: March 2003

BACKGROUND : TRALI is thought to be triggered by recipient‐specific anti‐HLA class I or antibodies against neutrophils in donor plasma. Recently, anti‐HLA class II have also been implicated. The prevalence of anti‐HLA class II was investigated in normal volunteer platelet donors and in two nonfatal TRALI cases utilizing a flow‐based assay. Potential target antigens also were investigated. STUDY DESIGN AND METHODS : Commercial flow cytometry‐based assays (FlowPRA, One Lambda, Inc.) for anti‐HLA class I and II were compared with standard lymphocytotoxicity tests. Subsequently, 151 volunteer platelet donors and two clinical cases of TRALI were screened with FlowPRA. Immunohistochemical studies were performed on lung tissue from a surgical case, an autopsy case, and a fatal TRALI case. RESULTS : The FlowPRA assays showed moderate concordance for anti‐HLA class I (κ = 0.448) and good concordance for class II antibodies (κ = 0.801), when compared to standard lymphocytotoxicity assays. Ten and 9 percent of female platelet donors were positive for anti‐HLA class I and class II, respectively. Two nonfatal cases of TRALI showed both anti‐HLA class I and anti‐HLA class II. Immunohistochemical analysis of a TRALI case revealed granulocyte aggregation in alveolar capillaries with activated vascular endothelial cells. HLA class II antigen expression was not present on vascular endothelium or intravascular WBCs; however, strong expression was seen on alveolar macrophages. CONCLUSION : FlowPRA assays often detect anti‐HLA class I not detected by conventional lymphocytotoxicity assays. These assays reveal anti‐HLA class II in normal female donor plasma and in sera implicated in TRALI. Immunohistochemical studies failed to reveal endothelial or intravascular‐WBC HLA class II antigen expression in lung tissue derived from TRALI cases or controls, but demonstrated HLA class II expression on pulmonary macrophages.
The Stochastic Volatility of Short‐Term Interest Rates: Some International Evidence
Authors: Ball Clifford A. , Torous Walter N. 
Published: March 2003

ABSTRACTThis paper estimates a stochastic volatility model of short‐term riskless interest rate dynamics. Estimated interest rate dynamics are broadly similar across a number of countries and reliable evidence of stochastic volatility is found throughout. In contrast to stock returns, interest rate volatility exhibits faster mean‐reverting behavior and innovations in interest rate volatility are negligibly correlated with innovations in interest rates. The less persistent behavior of interest rate volatility reflects the fact that interest rate dynamics are impacted by transient economic shocks such as central bank announcements and other macroeconomic news.
Valuation and Control in Venture Finance
Authors: Kirilenko Andrei A. 
Published: March 2003

ABSTRACTThis paper presents the model of a relationship between a venture capitalist and an entrepreneur engaged in the formation of a new firm. I assume that the entrepreneur derives private nonpecuniary benefits from having some control over the firm. I show that to separate the entrepreneur's value of control from the firm's expected payoff, the venture capitalist demands disproportionately higher control rights than the size of his equity investment. The entrepreneur is compensated for a greater loss of control through better terms of financing, ability to extract higher rents from asymmetric information, and improved risk sharing.
Survival Bias and the Equity Premium Puzzle
Authors: Li Haitao , Xu Yuewu 
Published: March 2003

ABSTRACTPrevious authors have raised the concern that there could be serious survival bias in the observed U.S. equity premium. Contrary to conventional wisdom, we argue that the survival bias in the U.S. data is unlikely to be significant. To reach this conclusion, we introduce a general framework for modeling survival and derive a mathematical relationship between the ex ante survival probability and the average survival bias. This relationship reveals the fundamental difficulty facing the survival argument: High survival bias requires an ex ante probability of market failure, which seems unrealistically high given the history of world financial markets.
Cantonese Speakers and the Acquisition of French Consonants
Authors: Cichocki W. , House A.B. , Kinloch A.M. , Lister A.C. 
Published: March 2003

This chapter reports the findings of research on the acquisition of French consonants by native speakers of Cantonese. The corpus is noteworthy because few studies have investigated this particular interlanguage. Indeed, although our knowledge of the phonology of French is rich, we know considerably less about Cantonese. As members of different language families, French and Cantonese display phonetic and phonological features that differ along various tiers of analysis; one of the important differences illustrated in this study is the [voice] feature.The principle guiding our research on Cantonese‐French interlanguage is the Markedness Differential Hypothesis (MDH), which invokes notions of universal markedness to make predictions about which target language forms are more difficult to acquire than others. Although the fact that it provides testable hypotheses makes it an attractive framework, the MDH has its share of difficulties. We show that the MDH can explain several major patterns of difficulty, but that other errors found can be explained in terms of an interaction of language acquisition and markedness reversals. Our ongoing research on the interlanguage vocalic system suggests other interactions between the hypothesized markedness relations and language transfer facts. Noteworthy is the fact that the markedness relations have been established on the basis of typological, and not necessarily Universal Grammar, universals.The methodological issue of defining standards of acceptable/unacceptable responses in learning research continues to be problematic. A well‐defined and quantitative measure of difficulty is attractive for applications in language learning, yet continuous acoustic spaces such as vowels or prosodic features provide challenges to this goal. In this study, we develop a scale of difficulty of consonants in both initial and final positions. For consonants we use judgements of unimpeded understanding, and these prove to offer a workable approach.