bluuebunny/crossref_metadata_2025_split huggingface dataset:
Different preparation methods to obtain platelet components as a source of growth factors for local application
Authors: Zimmermann Robert , Jakubietz Rafael , Jakubietz Michael , Strasser Erwin , Schlegel Andreas , Wiltfang Jörg , Eckstein Reinhold 
Published: March 2003

BACKGROUND: Autologous platelet components were recently used as part of tissue‐engineering strategies in oral and maxillofacial surgery. Various preparation methods were investigated to define standardized blood bank components and to collect data on the growth factor content of human platelets before and after storage.STUDY DESIGN AND METHODS: Apheresis platelets (AP), buffy coat‐derived platelets (BCP), platelets prepared by tube method (TP), and highly concentrated samples prepared from AP and from BCP were evaluated for standard quality criteria of platelet components and for their concentration of transforming growth factor (TGF)‐ß1, platelet‐derived growth factor (PDGF)‐AB, and PDGF‐BB. AP were stored for 5 days. On Days 3 and 5, these components and freshly prepared, highly concentrated samples were evaluated for the same measures.RESULTS: Platelet concentration in TP was lower than that in the other groups (p<0.05). However, the concentrations of PDGF‐AB, PDGF‐BB, and TGF‐ß1 were comparable in the three groups. TP showed higher spontaneous CD62 expression than did AP and BCP. The three preparation procedures resulted in significantly different WBC contamination, with the highest levels in TP. For the whole series of measurements, there was a strong correlation between growth factor levels and platelet concentration (p<0.05), which was due to the face that the growth factor content of concentrated platelet samples was tenfold that of AP, BCP, and TP. In TP, the WBC concentration was correlated with PDGF levels (p<0.05). After 5‐day storage, the mean levels of PDGF‐AB, PDGF‐BB, and TGF‐ß1 were 57.1, 43.0, and 72.0 percent of the initial values in AP. Overall, multiple regression analysis revealed the following factors influencing the measured growth factor concentrations: platelet concentration, baseline CD62 expression, lactate production, and WBC contamination.CONCLUSION: Various methods enable the preparation of platelet components and of highly concentrated components for local use according to standard blood banking criteria. The obtained components differ, particularly in their WBC content and in vitro platelet activation. These findings are relevant for planning and evaluating further studies of locally usable autologous platelet components.
A study of 178 consecutive vasovagal syncopal reactions from the perspective of safety
Authors: Newman Bruce H. , Graves Susan 
Published: March 2003

BACKGROUND: While vasovagal syncopal reactions have been studied in the past, there are several safety questions that could be further addressed. The purpose of this study was to address these safety questions.STUDY DESIGN AND METHODS: One hundred seventy‐eight vasovagal reactions were reported in 1999 from 194,000 blood donations. The reactions were retrospectively reviewed for 38 variables that included donor demographics, symptoms, injury, and final disposition.RESULTS: Sixty‐one percent of the syncopal reactions occurred at the refreshment table and 12 percent offsite. Fourteen percent of the donors sustained an injury, usually to the head (10%). Eleven donors (6%) had additional medical care in an emergency room: 4 for injuries, 3 for delayed recovery, and 4 for offsite syncope. None of the donors was admitted to the hospital. One of the injured donors developed postconcussion syndrome and had later sequelae.CONCLUSION: Syncopal reactions most commonly occur at the refreshment table, where preventive safety measures against trauma could be applied. A significant number of syncopal reactions occur offsite, where the environment is less safe. The injuries that occur, particularly to the head, may in rare cases lead to long‐term sequelae.
Predicting response to plasma exchange in patients with thrombotic thrombocytopenic purpura with measurement of vWF‐cleaving protease activity
Authors: Mori Yoshitaka , Wada Hideo , Gabazza Esteban C. , Minami Nobuyuki , Nobori Tsutomu , Shiku Hiroshi , Yagi Hideo , Ishizashi Hiromichi , Matsumoto Masanori , Fujimura Yoshihiro 
Published: March 2003

BACKGROUND: Severe deficiency of vWF‐cleaving protease (vWF‐CPase) activity was recently found in patients with thrombotic thrombocytopenic purpura (TTP). Although the survival of patients with TTP has been dramatically improved with plasma exchange (PE), there are still many patients who are refractory to PE and immunosuppressive therapy. STUDY DESIGN AND METHODS: The activities of vWF‐CPase and its inhibitor were measured in 27 patients with nonfamilial TTP and hemolytic‐uremic syndrome (HUS) to examine the relationship between the clinical variables and vWF‐CPase activity. RESULTS: Eight of nine patients with HUS had more than 40 percent of vWF‐CPase activity, whereas one had 28 percent of the normal level at the acute phase. Ten of 12 TTP patients with a good outcome had a severe deficiency of vWF‐CPase activity and its inhibitor, whereas four of six patients with a poor outcome had a moderate deficiency of vWF‐CPase activity along with a lack of the inhibitor. PE produced normalization of the vWF‐CPase activity and neutralization of the inhibitor in TTP patients with a good outcome; however, some TTP patients with vWF‐CPase inhibitor had relapsed and required an immunosuppressive therapy. The response to the combination therapy with PE and immunosuppressive treatment was poor in TTP patients without a severe deficiency of vWF‐CPase activity. CONCLUSION: Assays of vWF‐CPase activity and its inhibitor may be useful for predicting the response to therapy and the outcome of patients with TTP. In some patients, nonfamilial TTP with a poor prognosis may not be caused by a constitutional or acquired deficiency of vWF‐CPase with its inhibitor. Although PE and immunosuppressive therapy are effective in patients with nonfamilial TTP and a vWF‐CPase inhibitor, other therapeutic modalities may be needed for nonfamilial TTP with unknown etiology.
Validation of the NucliSens Extractor combined with the AmpliScreen HIV version 1.5 and HCV version 2.0 test for application in NAT minipool screening
Authors: Jongerius John M. , Sjerps Margret , Cuijpers H. Theo M. , Van Drimmelen Harry A.J. , Van der Poel Cees L. , Reesink Henk W. , Molijn M. Hans J. , Peeters Geert A.H. , Peeters Ton P.W. , Lelie P. Nico 
Published: March 2003

BACKGROUND : Routine HCV NAT minipool screening (48 donations) of all blood donations was implemented in July 1999 and was combined with HIV NAT in November 2000. This report describes the validation of the NAT methods and the results of quality control testing. STUDY DESIGN AND METHODS : Nucleic acid was extracted from 2‐mL plasma samples by using an automated silica‐based extraction method (NucliSens Extractor, Organon Teknika). Eluates were tested with RT‐PCR (AmpliScreen HIV‐1 version 1.5 and AmpliScreen HCV version 2.0 test, Roche Diagnostic Systems). HIV‐1 and HCV RNA reference panels and run controls (PeliCheck and PeliSpy, respectively, Sanquin‐CLB) and human plasma minipools were used for NAT validation. RESULTS : The 95‐percent detection limit (and 95% CI) for HIV‐1 RNA genotype B, HIV‐1 RNA genotype E, and HCV RNA genotype 1 was 32 (19‐76), 30 (17‐72), and 21 (13‐44) genome equivalents (geq) per mL, respectively. During initial validation, 2332 samples for HIV‐1 RNA and 2644 samples for HCV RNA were analyzed, with 13 (0.56%) and 12 (0.45%) invalid test results, respectively. Thereafter, over 19,600 samples (minipools and run controls) were analyzed during the first 11 months of routine screening. Invalid test results for HIV‐1 RNA and HCV RNA were found in 1.1 and 1.07 percent of the samples tested, respectively. HIV‐1 RNA minipool testing resulted in 27 (0.16%) initial false‐positive results and 3 (0.02%) confirmed positive results. HCV RNA minipool testing resulted in four (0.02%) initial false‐positive results and five (0.02%) confirmed positive results. CONCLUSION : Routine HIV and HCV NAT minipool screening using the NucliSens Extractor, AmpliScreen HIV‐1 version 1.5, and AmpliScreen HCV version 2.0 meets the sensitivity criteria set by the regulatory bodies and provides sufficient specificity and robustness for timely release of blood donations.
Sensitivity of HCV core antigen and HCV RNA detection in the early infection phase
Authors: Nübling C. Micha , Unger Gabriele , Chudy Michael , Raia Steven , Löwer Johannes 
Published: March 2003

BACKGROUND : Various countries have introduced HCV NAT to exclude infectious donations collected during the preseroconversion window phase (PWP). For the same purpose, an ELISA has also been developed to detect HCV core antigen (cAg). STUDY DESIGN AND METHODS : Using sequential samples from regular plasma donors with very recent HCV infections, a total of 494 samples from 52 anti‐HCV‐negative donors were collected. These panels were used for direct comparison of the performance of PCR and ELISA in detecting viral markers (RNA and cAg) during the PWP of HCV infection. The panels were genotyped, and each sample was analyzed by qualitative and quantitative HCV PCR and by cAg ELISA. The HCV RNA doubling time was calculated from quantitation of viral RNA in consecutive samples during the earliest outbreak of viremia. RESULTS : Concurrent detection of HCV RNA and cAg in 218 and nondetection in 185 samples yielded 81.6‐percent concordance in the results of 494 samples. Unidirectional discrepancy of results (i.e., PCR positive and cAg negative) was seen in 91 of 494 (18.4%) samples, which was consistent with 65 specimens with RNA concentrations ranging between 300 and 100,000 IU per mL and 26 specimens with less than 300 IU per mL (limit of quantitative PCR). Individual genotyped panels had different kinetics and courses of viremia. The mean doubling time in the early PWP at the onset of viremia was derived to be 10.8 (range, 5.8‐21.0) hours. CONCLUSION : A majority of HCV RNA‐positive samples were also cAg‐positive during the PWP. The current cAg detection corresponds to 100,000 IU per mL of HCV RNA. Since low‐titer samples would be identified only by single‐donation NAT, which is often affordable only in developed countries, the cAg ELISA could offer a practical alternative for some countries. The doubling time for HCV RNA at the onset of viremia corresponds to a calculated mean delay of cAg detection during the virus burst phase of 2 or 5 days, when compared with minipool (5000 IU/mL) or single‐donation NAT (50 IU/mL), respectively.
Partitioning of human and sheep forms of the pathogenic prion protein during the purification of therapeutic proteins from human plasma
Authors: Stenland Christopher J. , Lee Douglas C. , Brown Paul , Petteway Stephen R. , Rubenstein Richard 
Published: March 2003

BACKGROUND: Therapeutic proteins derived from human plasma and other biologic sources have demonstrated an excellent safety record relative to the potential threat of transmissible spongiform encephalopathy (TSE) transmission. Previously, hamster‐adapted scrapie was used as a model agent to assess TSE clearance in purification steps leading to the isolation of biopharmaceutical proteins. The current study investigated the validity of hamster scrapie as a model for human TSE clearance studies. The partitioning of the pathogenic forms of the prion protein associated with human variant CJD (PrPvCJD), human sporadic CJD (PrPsCJD) and Gerstmann‐Sträussler‐Scheinker (PrPGSS) syndrome was compared to the partitioning of hamster scrapie (PrPSc) in three plasma protein purification steps. Sheep scrapie (PrPSc) was similarly evaluated. STUDY DESIGN AND METHODS: The starting materials for three plasma protein purification steps, cryoseparation, 3 percent PEG separation, and 11.5 percent PEG separation, were spiked with brain homogenates containing human PrPvCJD, human PrPsCJD, human PrPGSS, sheep PrPSc, and hamster 263K PrPSc. The partitioning of the pathogenic form of the PrP was analyzed. RESULTS: Clearance of the pathogenic form of the PrP was measured relative to the effluent fraction. Regardless of the source of the pathogenic prion, clearance was similar to hamster PrPSc. A nominal amount of clearance (approx., 1 log), an intermediate amount of clearance (approx., 2 log), and a substantial amount of clearance (≥3 log) were observed for the cryoseparation, 3 percent PEG separation, and 11.5 percent PEG separation steps, respectively. In the latter step, no PrP was detected in the effluents. CONCLUSIONS: These data demonstrate that human prions, including vCJD prions, can be removed during the purification of human therapeutic proteins and indicate that partitioning of human prions is similar to that observed in the hamster scrapie model.
A puzzling case of anemia
Authors: Haddad Salim A. , Winer Karen K. , Gupta Anurag , Chakrabarti Sakti , Noel Pierre , Klein Harvey G. 
Published: March 2003

BACKGROUND : Iron deficiency anemia in adults is most frequently due to chronic blood loss. When the clinical course is complicated by sudden, severe declines in Hb concentration, the cause, nature, and lo‐ cation of bleeding may require an extensive clinical evaluation. CASE REPORT : A 39‐year‐old woman was admitted for management of refractory hypoparathyroidism related to total thyroidectomy for Graves' disease. Two weeks before admission, her Hb level was 7.0 g per dL. Despite transfusion with four units of RBCs during this interval, her admission Hb level was 5.7 g per dL. There was no evidence of blood loss or hemolysis. Laboratory values were consistent with an iron‐deficient state. The patient's hospital course included repeated instances of sharp Hb drop and appropriate but unsustained response to RBC transfusion. Extensive work‐up identified no occult source of bleeding. Clinical suspicion raised the possibility of self‐inflicted blood loss. The patient subsequently admitted to repeatedly drawing blood from her indwelling catheter and discarding it in the lavatory. CONCLUSION : Munchausen syndrome should be considered in cases of unexplained anemia, especially in the target demographic group: young, female, healthcare professionals. Early diagnosis may prevent morbidity, multiple hospitalizations, and the risk of invasive diagnostic procedures.
Long‐term production of pre‐existing alloantibodies to E and c after allogenic BMT in a patient with aplastic anemia resulting in delayed hemolytic anemia
Authors: Izumi Noriko , Fuse Ichiro , Furukawa Tatsuo , Uesugi Yumiko , Tsuchiyama Junjiro , Toba Ken , Togashi Kazue , Yamada Keiko , Ohtake Sachiko , Saitoh Yukiko , Yanagisawa Naoe , Aizawa Yoshifusa 
Published: March 2003

BACKGROUND : Delayed hemolysis mediated by long‐term production of pre‐existing recipient‐derived antibodies directed against donor RBC antigens after allogenic BMT is an unusual complication of hematopoietic transplantation. CASE REPORT : A 26‐year‐old man with aplastic anemia had pre‐existing alloantibodies to E and c. He received BMT from a donor, whose Rh phenotype was E+, c+. From about 1 month after the transplant, he showed mild hemolysis due to the antibodies. RESULTS : The patient was typed as group B, CCDee and had anti‐E and c alloantibodies before BMT. The donor was typed as group O, ccDEE. Although MNCs from the donor marrow were infused into the patient, DAT became positive on Day 21, and the patient‐origin antibodies remained detectable by both DAT and IAT even 20 months after BMT. However, immunomagnetically isolated peripheral circulating B cells were 100 percent donor origin. The patient received prednisolone from Day 221, and thereafter, the signs of hemolysis disappeared. CONCLUSION : It is likely that the long‐term production of alloantibodies is due to the existence of long‐lived recipient plasma cells, which survive the conditioning regimen. This case suggests that patients with pre‐ existing alloantibodies that do not belong to the ABO system should be carefully followed up after BMT.
Transvenous Defibrillation Leads: High Incidence of Failure During Long‐Term Follow‐Up
Authors: DORWARTH UWE , FREY BERNHARD , DUGAS MARTIN , MATIS TOMAS , FIEK MICHAEL , SCHMOECKEL MICHAEL , REMP THOMAS , DURCHLAUB ILKA , GERTH ANDREA , STEINBECK GERHARD , HOFFMANN ELLEN 
Published: March 2003

Implantable Defibrillator Lead Failure. Introduction: Patients with implantable cardioverter defibrillators (ICD) critically depend on correct functioning of their system. The aim of this study was to determine the incidence and clinical presentation of transvenous ICD lead failures during long‐term follow‐up.
Methods and Results: The study group consisted of 261 consecutive patients who received Medtronic right ventricular polyurethane transvenous leads (models 6884, 6966, 6936) between 1990 and 1998 as part of an abdominal

(n = 70)

or pectoral

(n = 191)

ICD system. During mean follow‐up of

4.0 ± 2.6 years

, 31 patients (12%) developed a lead‐related sensing failure with oversensing of artifacts. All failures except two were compatible with an insulation defect and occurred late after ICD placement (

6.0 ± 1.8 years

after implant). Lead survival decreased from 98% at 4‐year follow‐up to only 62% at 8‐year follow‐up. Lead survival was not related to patient age, sex, venous lead implantation route, or device implantation site. In 26 (87%) of 31 patients, a sensing defect resulted in inappropriate detection of ventricular fibrillation and subsequent delivery of

3 ± 3

(range 1–11) inappropriate shocks in 19 (61%) of 31 patients. Device interrogation showed artifacts classified as nonsustained ventricular tachycardia in 21 patients,

40 ± 43 days

before clinically relevant failure of the system. One patient with a subclavian crush syndrome required resuscitation because of undersensing of true ventricular fibrillation.
Conclusion: Transvenous polyurethane ICD leads showed a high rate of lead insulation failure late after implantation with frequent inappropriate shock deliveries. Close follow‐up is mandatory in patients with these leads. Automated device control features with patient alert function integrated into new devices may contribute to early detection of lead failure.
Effect of Coronary Sinus Electrode on the Optimal Atrial Defibrillation Pathway for an Atrioventricular Defibrillator
Authors: TSE HUNG‐FAT , TIMMERMANS CARL , RODRIGUEZ LUZ‐MARIA , LAU CHU‐PAK , WELLENS HEIN J.J. 
Published: March 2003

Atrial Defibrillation Pathway. Introduction: Previous studies have demonstrated significant failure in converting atrial fibrillation (AF) using a conventional ventricular pathway. The aim of this study was to assess the benefit of incorporating a coronary sinus (CS) lead into the atrial defibrillation pathway in atrial defibrillation threshold (ADFT) reduction in patients with persistent AF.
Methods and Results: This study was a prospective, randomized assessment of shock configuration on ADFT in 18 patients undergoing elective internal cardioversion for persistent AF (mean AF duration:

8 ± 9

months). The lead system included a dual‐coil defibrillation lead (Endotak DSP, Guidant) with a distal right ventricular (RV) electrode and a proximal superior vena cava (SVC) electrode, a CS lead (Perimeter, Guidant), and a left pectoral cutaneous electrode (Can). In each patient, dual step‐up ADFTs were determined for each of three vectors: (1) RV → SVC+Can; (2) CS → SVC+Can; and (3) RV → CS+SVC+Can (group 1, n = 8) or RV+CS → SVC+Can (group 2, n = 10), using R wave‐synchronized biphasic shocks. Successful defibrillation was achieved in all patients without any ventricular proarrhythmia. ADFT of CS → SVC+Can

(11.8 ± 5.6 J)

was significantly lower than ADFT of RV → SVC+Can

(16.5 ± 7.8 J, P = 0.021)
. ADFT of CS → SVC+Can was similar to RV → CS+SVC+Can (group 1:12.0 ± 6.5J vs17.4 ± 4.8 J, P = 0.16), but it was significantly higher than RV+CS → SVC+Can (group2: 9.0 ± 3.9J vs11.6 ± 5.0 J, P = 0.049).
Conclusion: Patients with persistent AF of substantial duration can be reliably cardioverted using a conventional implantable cardioverter defibrillator (ICD) lead set; however, the incorporation of a CS lead to the conventional ICD lead configuration significantly lowered ADFT. The optimal shock vector that incorporates a CS lead for atrial defibrillation requires future studies.
Hayden White (and the Content and the Form and Everyone Else) at the AHA
Authors: Partner Nancy 
Published: March 2003

The special session at the January 1997 annual meeting of the American Historical Association honoring the achievement of Hayden White and examining the impact and influence of his work on the historical discipline was an enlightening experience, at least to this participant, in many more ways than had been planned or promised. The session itself, albeit fairly routine by the standard of such occasions, seemed to take on a meta‐narrative of its own as each of the speakers (not excluding the honoree who was present and participating) confidently spoke at length, proceeding from deep premises which bore no relation to any of the others. My own initial anticipation that this event would produce limited variations on a coherent theme—the impact of the linguistic turn and of narrative theory in particular on the practice and self‐definition of academic history—turned gradually to rather disconcerted bemusement, especially when my turn came to listen to myself.My previous engagement to report on the AHA session in a paper for the Center for the Humanities at Wesleyan University became an opportunity to confide some of my freshest reactions to the event in a fairly small and very select audience. Narrating the ephemeral metanarrative I perceived as spinning itself out over the blunter facts of the AHA occasion, turned out to be the inner topic of my Wesleyan paper (this present essay), not excluding the mysterious impulses of the audience and the existential atmosphere of the never to be forgotten Princess Ballroom.
Making History, Talking about History
Authors: Barrera José Carlos Bermejo 
Published: March 2003

Making history—in the sense of writing it—is often set against talking about it, with most historians considering writing history to be better than talking about it. My aim in this article is to analyze the topic of making history versus talking about history in order to understand most historians' evident decision to ignore talking about history. Ultimately my goal is to determine whether it is possible to talk about history with any sense.To this end, I will establish a typology of the different forms of talking practiced by historians, using a chronological approach, from the Greek andRoman emphasis on the visual witness to present‐day narrativism and textual analysis. Having recognized the peculiar textual character of the historiographical work, I will then discuss whether one can speak of a method for analyzing historiographical works. After considering two possible approaches—the philosophy of science and literary criticism—I offer my own proposal. This involves breaking the dichotomy between making and talking about history, adopting a fuzzy method that overcomes the isolation of self‐named scientific communities, and that destroys the barriers among disciplines that work with the same texts but often from mutually excluding perspectives. Talking about history is only possible if one knows about history and about its sources and methods, but also about the foundations of the other social sciences and about the continuing importance of traditional philosophical problems of Western thought in the fields of history and the human sciences.