bluuebunny/crossref_metadata_2025_split huggingface dataset:
AnIn VitroBiomechanical Comparison of a Prototype Intramedullary Pin‐Plate with a Dynamic Compression Plate for Equine Metacarpophalangeal Arthrodesis
Authors: Sod Gary A. , Martin George S. 
Published: December 2004

ObjectivesTo compare the biomechanical properties of a prototype intramedullary pin‐plate (IMPP) implant specifically designed for equine metacarpophalangeal (MCP) arthrodesis with a dynamic compression plate (DCP) system.Study DesignIn vitrobiomechanical testing of paired cadaveric equine forelimbs with a simulated traumatic disruption of the suspensory apparatus, stabilized by one of two methods for MCP arthrodesis.Animal PopulationTwenty‐one pairs of adult equine cadaveric forelimbs.MethodsEach forelimb had the distal sesamoidean ligaments severed to create a disrupted suspensory apparatus. For each forelimb pair, the MCP joint was stabilized with the IMPP in one limb, and a DCP in the other limb. Seven matching limb pairs were tested in axial compression in a single cycle to failure, 7 matching limb pairs were tested in torsion in a single cycle to failure, and 7 matching limb pairs were fatigued tested in axial compression. Mean test variable values for each method were compared using a pairedt‐test within each group. Significance was set atP<.05.ResultsThe mean yield load, yield stiffness, and failure load (axial compression, torsional loading) was significantly greater for the IMPP compared with the DCP system. Mean cycles to failure for axial compression was significantly greater for the IMPP compared with the DCP system. Significance in all tests wasP<.0001.ConclusionThe IMPP was superior to the DCP system in resisting the biomechanical forces most likely to cause failure of MCP joint arthrodesis.Clinical RelevanceThe IMPP implant should be considered for MCP arthrodesis in horses with traumatic disruption of the suspensory apparatus. The specific design of the IMPP implant may facilitate equine MCP arthrodesis and avoid convalescent complications related to cyclic fatigue.
A Method for Radioactive Antiglobulin Testing with 125I Labeled Anti‐IgG
Authors: Jenkins D. E. , Moore W. H. , Hawiger A. 
Published: December 2004

The present report describes a method for 125I anti‐IgG antiglobulin testing. The method involves the use of a labeled DEAE cellulose IgG fraction of goat anti‐human IgG globulin. Leukocyte‐free red blood cells were used in the test procedure. Both the labeled antiserum and the red blood cell suspensions were diluted in normal rabbit serum to prevent nonspecific uptake of labeled antiserum by normal, un‐coated red blood cells.The results of the study show that the method is highly reproducible and relatively easy to perform once the labeled anti‐IgG is prepared. Furthermore, the use of labeled antiserum permits analysis of antiserum specificity by radioimmunoelectrophoresis. The problem of determining anti‐IgG/IgG binding ratios remains the major disadvantage to using the method to determine precise amounts of human IgG coating red blood cells.
Preservation of Human Granulocytes: II. Characteristics of Granulocytes Obtained by Counterflow Centrifugation
Authors: Lionetti F. J. , Hunt S. M. , Lin P. S. , Kurtz S. R. , Valeri C. R. 
Published: December 2004

Human granulocytes were isolated from whole blood and from the buffy coat of blood by counterflow centrifugation using the Beckman JE‐6 rotor. Ninety‐one per cent of granulocytes in the human blood sample were isolated in 59 studies. The differential white blood cell count showed 97 per cent segmented neutrophils, 1 per cent lymphocytes and 2 per cent others. The ratio of polymorphonuclear white blood cells to red blood cells was 9:1 when the granulocytes were isolated from whole blood and 40:1 when the granulocytes were isolated from the buffy coat of CPD‐collected blood. The size distribution showed a single symmetrical peak. Measurements of oxygen consumption, chemotaxis, and phagocytosis in granulocytes isolated by counter‐flow centrifugation were similar to those in granulocytes isolated from blood by dextran sedimentation. The granulocytes had normal adenine and guanine di‐ and trinucleotide levels.Scanning electron microscopy demonstrated spherical granulocytes with ridge‐like profiles and leafy folded exoplasm. After fluorescein diacetate treatment, the cytoplasm of 98.5 + 0.7 per cent of fresh granulocytes was positive, while 98.5 + 1.2 per cent of the fresh granulocytes excluded ethidium bromide from their nuclei. The response of freeze‐preserved granulocytes to treatment with fluorescein diacetate and ethidium bromide showed that 75 per cent of granulocytes survived freezing and thawing in 5 per cent DMSO but were progressively unstable after incubation for two hours at 37 C.
In Vitro Studies of Cryopreserved Baboon Granulocytes
Authors: Lionetti F. J. , Hunt S. M. , Mattaliano R. J. , Valeri C. R. 
Published: December 2004

Granulocytes were isolated from the buffy coat of baboon blood by counterflow centrifugation. They were frozen in polypropylene tubes in 2.0 ml volumes containing 1 × 107 granulocytes. The medium consisted of 5% DMSO, 6% HES, 4% human serum albumin, and 6 mM glucose in Normosol‐R, pH 7.1. Granulocytes were cooled to 4 C for 30 minutes, then cooled at 4 C per minute to –80 C and stored for one to three weeks in liquid nitrogen at –197 C. Cooling rates of 1 C and 10 C per minute were less efficacious. Tubes were thawed manually with swirling for 130 seconds at 42 C in a water bath. The yield after thawing was 98 ± 14 per cent.Granulocytes isolated from fresh blood all fluoresced green when incubated with fluorescein diacetate (FDA). Less than one per cent of cells showed nuclear uptake of ethidium bromide (EB). After freezing and thawing, an average of 79 ± 8 per cent granulocytes fluoresced green with FDA and 21 ± 8 per cent fluoresced red with EB. About 98 ± 2 per cent of the granulocytes isolated from fresh blood exhibited a serum dependent capacity for ingestion of latex and yeast. Thawed granulocytes were diluted 1:4 dropwise with a medium containing 7% HES, 4% albumin, and 6 mM glucose in Normosol‐R, incubated with fluorescent latex or fluorescent zymosan at 37 C for 30 minutes and then washed twice. After this, 75 ± 5 per cent demonstrated serum‐dependent latex ingestion and 67 ± 8 per cent ingested zymosan.
Effect of cardiopulmonary bypass on plasma fibronectin, IgG, and C3
Authors: Gandhi J. G. , Salm T. Vander , Szymanski I. O. 
Published: December 2004

The effect of cardiopulmonary bypass operations on the concentration of plasma fibronectin, IgG, and C3 was studied in 28 patients. During cardiopulmonary bypass operations, plasma IgG, and C3 decreased to about 45 percent of their preoperative concentrations, probably as a result of hemodilution and blood loss. On the average, plasma fibronectin decreased significantly more (p < 0.002), to 32 percent of its preoperative concentration, probably as a result of hemodilution, blood loss, and consumption. We assumed that consumption of fibronectin occurred when its concentration decreased more than the concentrations of IgG and C3. Interestingly, consumption of fibronectin during bypass operations was not demonstrated in seven of the 28 patients who did not require blood products within the 24‐hour period after operation. We suggest that consumption, rather than dilution, of plasma fibronectin might be clinically important. A significant (p < 0.002) negative correlation was observed between the length of the bypass and the concentration of plasma fibronectin during this 24‐hour period.We also studied the rate of regeneration of fibronectin, IgG, and C3 in 12 of these patients. The concentrations of fibronectin and C3 were normal by the fifth postoperative day. The rate of regeneration of IgG, however, was slower than that of fibronectin and C3.
Activation of the complement system by different autologous transfusion devices: an in vitro study
Authors: Tylman Maria , Bengtson Jan Peter , Bengtsson Anders 
Published: December 2004

BACKGROUND : The aim of the present investigation was to study whether autologous transfusion devices activate the complement system and whether complement‐activated blood is more vulnerable to further activation during processing. STUDY DESIGN AND METHODS : Forty‐eight blood units were randomized to be processed by one of three different salvage systems: Group 1 underwent whole blood filtration (hemofiltration) (n = 16); Group 2 underwent continuous processing, saline washing, and centrifugation (CATS, Fresenius AG ) (n = 16); and Group 3 underwent saline washing and centrifugation (Cell‐Saver, Haemonetics Corp.) (n = 16). Eight blood units for each system were activated with cobra venom factor (CVF) at a concentration of 0.2 U per mL whole blood before processing. C activation was studied by determinations of C4d, Bb, C3a, and SC5b‐9. Samples were drawn from whole blood, processed blood, and the waste bags. RESULTS : The concentrations of Bb, C3a, and SC5b‐9 in whole blood after activation with CVF were significantly elevated compared to blood that was not activated (p < 0.01). Processed blood from hemofiltration contained significantly higher levels of complement‐split products than techniques that use washing and centrifugation. The concentrations of SC5b‐9 in blood processed by hemofiltration were higher in the experiments with CVF activation (p < 0.05). CONCLUSION : The tested autologous transfusion systems did not themselves activate the complement system, and complement‐activated blood was not more vulnerable to further activation during processing. A blood‐salvaging technique that used washing and centrifugation reduced elevated concentrations of complement‐split products, whereas hemofiltration did not.
CMV DNA is rarely detected in healthy blood donors using validated PCR assays
Authors: Roback John D. , Drew W. Lawrence , Laycock Megan E. , Todd Deborah , Hillyer Christopher D. , Busch Michael P. 
Published: December 2004

BACKGROUND : Although serologic screening or WBC reduction of blood components can reduce the incidence of transfusion‐transmitted CMV (TT‐CMV) infection, ‘breakthrough’ cases of TT‐CMV still occur and may produce serious sequelae. NAT of blood components for CMV DNA has been proposed to further reduce the risks of TT‐CMV. However, large‐scale studies to determine the utility of validated CMV NAT assays for donor screening have not been reported. STUDY DESIGN AND METHODS : Coded whole‐blood samples (n = 1000) were tested for the presence of CMV DNA using two CMV PCR assays previously validated in a multicenter trial (a nested PCR assay directed at the CMV UL93 open‐reading frame and the Roche Monitor assay). Corresponding plasma samples were tested in parallel for the presence of anti‐CMV using other assays (Abbott CMV EIA and Fujirebio/Olympus CMV particle agglutination assays). RESULTS : In total 416 and 514 of the samples tested as CMV‐seropositive and ‐seronegative, respectively, by both antibody assays. The remaining 70 samples had discrepant serology results. Only 2 of the 1000 samples (both seropositive) had reproducibly detectable CMV DNA (positive in at least three of four replicates). CMV DNA was not reproducibly detected in seronegative samples or in samples with discrepant serology results. CONCLUSIONS : Although previous investigations showed frequent detection of CMV DNA in healthy CMV‐seropositive (and some seronegative) blood donors, these studies were relatively small and the performance characteristics of their assays were difficult to evaluate. In contrast, the present large cross‐sectional study of US donors utilized two previously validated PCR assays and demonstrated that CMV DNA is only rarely detectable in seropositive donors. Thus, the use of CMV PCR assays with optimal performance characteristics did not increase the detection of potentially infectious blood components beyond that provided by current serologic screening assays.
Systematic analysis of the ABO gene diversity within exons 6 and 7 by PCR screening reveals new ABO alleles
Authors: Seltsam Axel , Hallensleben Michael , Kollmann Anke , Burkhart Jürgen , Blasczyk Rainer 
Published: December 2004

BACKGROUND: Mutations critical for ABO blood group phenotypes have predominantly been found in exons 6 and 7 of the ABO gene, both of which encode the catalytic domain of ABO glycosyltransferase. To design rapid and reliable ABO genotyping assays, a profound knowledge of the prevalent alleles is required and a reliable sequence database needs to be established. STUDY DESIGN AND METHODS: A PCR screening system was established consisting of 102 different PCRs, each specific for a single nucleotide (nt) variation. The primer mixes were developed to walk from the 5′ to the 3′ end of exons 6 and 7 of the ABO gene to screen for nt mutations at 50 known polymorphic sites. A total of 109 unrelated individuals with common and rare ABO characteristics were screened. All blood samples in which the PCR results were inconclusive or inconsistent with the ABO phenotypes were subjected to sequence analysis of exons 6 and 7. RESULTS: The results of PCR screening were conclusive and consistent with the ABO phenotypes in 90 cases. In the remaining 19 cases, PCR screening revealed unusual allele combinations or amplification results that were incompatible with known ABO allele combinations or subgroups predicted by serologic analysis. In these 19 cases, sequencing revealed new ABO alleles (one ABO*Ael allele, one ABO*B(A) allele and two ABO*O alleles) in two individuals with common and seven individuals with variant ABO phenotypes. CONCLUSION: This PCR screening strategy is an effective tool for obtaining deeper insight into the ABO gene diversity and diversification and may be useful to increase the quality of the ABO sequence database.
RBC transfusion requirements after allogeneic marrow transplantation: impact of the before‐transplant Hb level on transfusion and early survival
Authors: Xenocostas Anargyros , Yee Angelina , Wong Cindy J. , Sutton David M.C. , Lipton Jeffrey H. , Kiss Thomas L. , Messner Hans A. 
Published: December 2004

BACKGROUND: Most patients undergoing allogeneic marrow transplantation (alloBMT) require transfusions of RBCs. A retrospective analysis was performed to evaluate the utilization and risk factors for RBC transfusions including age and sex of recipient, HLA matching between donor and recipient, disease status at time of BMT, the occurrence of GVHD, ABO blood group compatibility, the source of progenitor cells and the Hb level before BMT (PT‐Hb).STUDY DESIGN AND METHODS: Data from 519 consecutive patients receiving transplants between January 1995 and March 2000 were reviewed. The number of RBC transfusions was determined for the following periods: 0 to 60, 61 to 120, and 121 to 180 days after BMT.RESULTS: The transfusion requirements were greatest during the first 60 days after BMT and decreased with time. The total number of units transfused to this cohort of patients was 5398, of which 3505 units were utilized within the first 2 months. The mean number ± SD of units transfused per patient from 0 to 60 days was 6.8 ± 6.4; 61 to 120 days, 3.2 ± 5.5; and 121 to 180 days, 2.0 ± 4.6. An increased transfusion requirement was associated with lower PT‐Hb, major ABO mismatch between donor and recipient, BMT in patients with more advanced disease, use of unrelated donors, older age, and female sex by Spearman's correlation analysis. The source of progenitor cells and the development of GVHD did not influence transfusion requirements. Increased mortality during the 6‐month period after transplant was associated with lower PT‐Hb, use of unrelated donors, advanced disease status at BMT, and sex by Cox regression analysis. In a multivariate model, PT‐Hb remained significant when controlling for the other risk factors.CONCLUSION: The PT‐Hb was identified as an independent risk factor for RBC transfusions during alloBMT. As well, a lower PT‐Hb was found to be an independent risk factor for increased mortality during the 6‐month study period.
MP4, a new nonvasoactive PEG‐Hb conjugate
Authors: Vandegriff Kim D. , Malavalli Ashok , Wooldridge Jerod , Lohman Jeff , Winslow Robert M. 
Published: December 2004

BACKGROUND: Vasoconstriction has been an obstacle to clinical development of Hb‐based O2 carriers. It is proposed that this limitation can be overcome by increasing molecular size and oxygen affinity. STUDY DESIGN AND METHODS: Surface‐modified Hb (MP4) was designed, whose properties are consistent with the theory that cell‐free Hb engages autoregulatory vasoconstrictive responses to Hb diffusion in the plasma space (“facilitated diffusion”). Human Hb was modified by reaction first with 2‐iminothiolane to add sulfhydryl groups and then with monofunctional maleimide‐ activated 5‐kDa PEG. RESULTS: MP4 was found to have a molecular weight of 90 kDa, a molecular radius increased relative to native Hb (9.3 ± 1.4 vs. 3.2 nm), high oxygen affinity (p50∼ 5‐6 mmHg), and a Bohr effect approximately half that of native human Hb (–0.24Δlogp50/ΔpH). At 4.2 g per dL in Ringer's lactate, its viscosity was 2.5 cP, and its oncotic pressure was 50 mmHg. The t50 of 14C‐MP4 in rats was approximately 24 hours. No significant elevation in mean arterial pressure was observed. CONCLUSION: MP4 appears to be free of a pressor effect, a major limitation to the development of a safe and effective RBC substitutes in the past.
Apoptotic activity in stored human platelets
Authors: Perrotta Peter L. , Perrotta Cheryl L. , Snyder Edward L. 
Published: December 2004

BACKGROUND: Platelets possess some of the machinery required for apoptotic cell death. However, disruption of mitochondria function, implicated in several models of cell death, has not been extensively studied in platelets. Mitochondrial viability and several other measures of apoptotic death in stored and experimentally stressed platelets were evaluated. MATERIALS AND METHODS: Platelet mitochondrial transmembrane potentials (Δψm) were studied by staining platelets with JC‐1, a dye that fluoresces at different wavelengths based on the state of mitochondrial polarization. Annexin V binding, a measure of phosphatidylserine (PS) exposure, and CD62P expression, an indicator of platelet activation, were determined by flow cytometry. Caspase‐3 activity was measured with an enzyme assay and by Western blotting. Experimental platelet stressors included storage for 7 days, azide exposure, calcium ionophore stimulation, and plasma deprivation. RESULTS: As measured by flow cytometry, Δψm values were similar in freshly drawn platelets and in platelet concentrates stored for up to 7 days. However, compared to fresh platelets, stored platelet concentrates had significantly increased PS exposure (3.1 vs. 5.1%, p = 0.015), CD62P expression (6.5 vs. 13.5%, p = 0.0067), and caspase‐3 activity. Azide exposure, which decreased ATP release 20 to 30 percent, did not affect the Δψm. Stressed platelets exhibited higher degrees of mitochondrial depolarization in response to calcium ionophore stimulation than platelets that were not stressed. Plasma deprivation also resulted in significant alterations in Δψm, PS exposure, and CD62P expression. CONCLUSIONS: Platelet mitochondria maintain Δψm when stored for up to 7 days under standard blood bank storage conditions. Therefore, changes in platelet mitochondria Δψm do not correlate with downstream markers of apoptotic death such as caspase activation and PS exposure.
A closed and single‐use system for monocyte enrichment: potential for dendritic cell generation for clinical applications
Authors: Rouard Helene , Leon Anne , De Reys Stef , Taylor Linda , Logan Josephine , Marquet Jeanine , Jouault Helene , Loper Kathy , Maison Patrick , Delfau‐Larue Marie‐Helene , Beaujean Françoise , Farcet Jean‐Pierre , Noga Stephen J. 
Published: December 2004

BACKGROUND: This study evaluated the ability of a modified cell separator (Cobe Spectra Apheresis) system to isolate monocytes (MOs) by elutriation. The evaluation was performed in two independent international laboratories. The capacity of collected MOs to differentiate into dendritic cells (DCs) was also assessed. STUDY DESIGN AND METHODS: MNCs from platelet apheresis residues were elutriated on a modified cell separator (Cobe Spectra Apheresis system) using a custom disposable set. Cells were separated according to their size and density. Recovery and purity of the collected cell product were evaluated by impedance counting and flow cytometry. DCs were differentiated in culture from the elutriated MOs and characterized by their surface markers and stimulatory capacity in a mixed WBC reaction assay. RESULTS: Six apheresis mononuclear cell products were used by each laboratory. The separation was achieved in less than 1 hour. Collected MOs had the potential to differentiate into DCs. CONCLUSION: The modified cell separator is an easy and fast device to obtain highly enriched MOs with a DC differentiation potential. The system is closed and employs a single‐use disposable set and is more amenable to good tissue practice. This method could become a valuable tool for DC‐based active immunotherapy.
Comparative sensitivity of HBV NATs and HBsAg assays for detection of acute HBV infection
Authors: Biswas Robin , Tabor Edward , Hsia Chu Chieh , Wright David J. , Laycock Megan E. , Fiebig Eberhard W. , Peddada Lorraine , Smith Richard , Schreiber George B. , Epstein Jay S. , Nemo George J. , Busch Michael P. 
Published: December 2004

BACKGROUND: A study was designed to estimate relative analytic sensitivity and window‐period (WP) closure and to project incremental yield of newer HBsAg tests, pooled‐sample NAT, and single‐sample NAT, compared to currently licensed HBsAg tests. STUDY DESIGN AND METHODS: HBV DNA and HBsAg test results for 23 HBV seroconversion (SC) panels were first analyzed to construct a model of primary HBV viremia. One‐hundred representative samples were then selected from 10 panels and coded with 28 analytical controls. All 128 samples were tested by seven HBsAg tests and by four pooled‐sample and three single‐sample NAT assay formats. Results were analyzed to obtain differential times to HBV detection and combined with HBV incidence rates to project comparative yields. RESULTS: HBV doubling time during the ramp‐up phase was estimated at 2.56 days. HBsAg concentrations at cutoff for new tests ranged from 0.07 to 0.12 ng per mL, compared with 0.13 to 0.62 ng per mL for licensed tests. Estimated viral load at cutoff ranged from 102 to 267 IU per mL for new tests and from 363 to 1069 IU per mL for licensed tests. HBsAg tests detected 31 to 63 percent of early ramp‐up phase samples in the 100‐member seroconversion panel study, while pooled‐sample NAT detected 55 to 71 percent and single‐sample NAT, 82 to 99 percent. Compared with currently licensed HBsAg assays, newer HBsAg assays would reduce the WP by 2 to 9 days; pooled‐sample NAT would reduce the WP by 9 to 11 days; and single‐sample NAT would reduce the WP by 25 to 36 days. CONCLUSION: Newer HBsAg tests would be expected to detect an additional 15 to 21 infected units per 107 donations, compared to licensed HBsAg tests. Sensitivity, WP closure, and yield projections for newer HBsAg assays and pooled‐sample NAT are comparable. Single‐sample NAT would increase yield by 13 to 15 units per 107 donations over pooled‐sample NAT and newer HBsAg assays and by 35 to 50 units per 107 donations over currently licensed HBsAg assays.