bluuebunny/crossref_metadata_2025_split huggingface dataset:
Red cell concentrates of hemochromatosis patients comply with the storage guidelines for transfusion purposes
Authors: Luten Marleen , Roerdinkholder‐Stoelwinder Bregt , Rombout‐Sestrienkova Eva , De Grip Willem J. , Bos Harry J. , Bosman Giel J.C.G.M. 
Published: February 2008

BACKGROUND: Therapeutic phlebotomy is the preferred treatment for iron overload associated with hemochromatosis. In the Netherlands, red blood cell concentrates (RCCs) from hemochromatosis patients are not used for transfusion purposes. In this study, their storage performance was compared with that of control donors as a first step in the evaluation of their potential usefulness for transfusion.STUDY DESIGN AND METHODS: RCCs were obtained from hemochromatosis patients and regular donors, either by apheresis or by whole‐blood collection, and stored up to 50 days under routine Dutch blood bank conditions. Weekly samples were taken for determination of hematologic, biophysical, and biochemical variables.RESULTS: Most variables displayed the same storage‐related changes in RCCs originating from hemochromatosis patients as in those from regular donors. In all RCCs, hemolysis remained well below the guideline limit of 0.8 percent for up to 6 weeks of storage, and the glucose concentration remained above the required 5 mmol per L up to 5 weeks of storage. After 4 weeks of storage, the mean ATP level remained above the required limit of 75 percent of the starting value in all RCCs as well. The major difference was a larger mean cell volume in hereditary hemochromatosis RBCs up to 50 days of storage.CONCLUSIONS: RCCs from hemochromatosis patients comply with the in vitro quality requirements for transfusion. This paves the way for the final step, namely, the establishment of the 24‐hour RBC posttransfusion recovery.
Heterogeneity of HPA‐3 alloantibodies: consequences for the diagnosis of alloimmune thrombocytopenic syndromes
Authors: Socher Ines , Zwingel Claudia , Santoso Sentot , Kroll Hartmut 
Published: February 2008

BACKGROUND: Immunization against the human platelet alloantigen (HPA)‐3a residing on αIIbβ3 integrin accounts for approximately 2 percent of fetal and neonatal alloimmune thrombocytopenia (FNAIT). Anti‐HPA‐3a alloantibodies are sometimes difficult to detect and can be overlooked by standard antigen capture assays.STUDY DESIGN AND METHODS: The reactivity of 12 anti‐HPA‐3a and 2 anti‐HPA‐3b alloantibodies from patients with FNAIT and posttransfusion purpura was analyzed by serologic (monoclonal antibody‐specific immobilization of platelet antigens [MAIPA] assay, flow cytometry) and immunochemical (immunoprecipitation, immunoblotting) techniques. The influence of platelet (PLT) age, storage conditions, recombinant antigens from Chinese hamster ovary (CHO) cells, and sialic acids (treatment with neuraminidase) were analyzed.RESULTS: The most sensitive anti‐HPA‐3 alloantibody detection in MAIPA assay could be achieved with fresh homozygous PLTs. During a PLT storage period of 14 days before use, three types of anti‐HPA‐3 alloantibodies were found: 1) complete loss of reactivity (n = 6), 2) considerably weakened reaction (≥50% reduction; n = 3), and 3) minor reduction of reactivity (≤40% decrease; n = 5). When cryopreserved PLTs were used, 10 of 12 anti‐HPA‐3a and all anti‐HPA‐3b alloantibodies reacted positive. Only 6 of 10 serum samples reacted with recombinant HPA‐3a on CHO cells. Neuraminidase treatment of PLTs showed that some anti‐HPA‐3a alloantibodies require the presence of sialic acids. The storage lesion seems to be related to cleavage of sialic acids. Immunochemical analysis revealed evidence that most anti‐HPA‐3a alloantibodies require an intact three‐dimensional αIIbβ3 integrin structure.CONCLUSIONS: Anti‐HPA‐3 alloantibodies show considerable heterogeneity, which may hamper the serologic diagnosis of FNAIT. Preservation of the αIIbβ3 integrin and protection from enzymatic degradation seem to be important during PLT storage.
Expression of a novel missense mutation found in the A4GALT gene of Amish individuals with the p phenotype
Authors: Hellberg Åsa , Schmidt‐Melbye Anne‐Christine , Reid Marion E. , Olsson Martin L. 
Published: February 2008

BACKGROUND: The rare p phenotype is found at a higher frequency in Amish people than in other populations. Different mutations in the 4‐α‐galactosyltransferase gene (A4GALT), responsible for synthesis of Pk (Gb3) antigen, have been found to cause the Pk‐deficient p phenotype. The aim of this study was to explore the molecular background of the p phenotype in people of Amish origin.STUDY DESIGN AND METHODS: Twenty blood samples with the p phenotype, 19 of them from Amish individuals and 1 Pakistani, were investigated. Amplification of genomic DNA by polymerase chain reaction (PCR) and sequencing by capillary electrophoresis were performed. Blood donors of different geographic origin were screened with PCR–allele‐specific primer to investigate whether the novel mutation occurs among individuals with common phenotypes. The mutation was also cloned into an expression vector and transfected to Namalwa cells, which do not normally express Pk. Pk expression on the transfected cells and P/Pk on red blood cells (RBCs), both with p and with common phenotypes, were analyzed by flow cytometry.RESULTS: All 20 samples were homozygous for 299C>T changing serine to leucine in a region that is highly conserved in homologous genes across species borders. The mutation was not found in any of the 500 alleles of blood donors investigated. Pk expression was neither observed by serology and flow cytometry on p RBCs from Amish individuals nor following transfection of cells with constructs containing the novel missense mutation.CONCLUSION: A novel A4GALT missense mutation causes the p phenotype in Amish individuals.
Sec1‐FUT2‐Sec1 hybrid allele generated by interlocus gene conversion
Authors: Soejima Mikiko , Fujihara Junko , Takeshita Haruo , Koda Yoshiro 
Published: February 2008

BACKGROUND: Many single‐nucleotide polymorphisms have been identified in the coding region of the FUT2 locus, which encodes secretor type α(1,2)fucosyltransferase. In addition, three recombination alleles have been reported. Of these recombination alleles, a fusion gene generated by an unequal crossing over between Sec1, a pseudogene that locates 23 kb upstream to and has high sequence homology with FUT2 and FUT2, was identified as a Japanese‐specific nonsecretor allele (sefus).STUDY DESIGN AND METHODS: During the screening of the sefus in Mongolians (n = 118), a hybrid allele of Sec1‐FUT2‐Sec1 was found.RESULTS: The DNA sequence suggested that the Sec1‐FUT2‐Sec1 allele contains a 275‐bp sequence (between positions 259 and 533) that is identical to the FUT2 sequence including a 54‐bp FUT2‐specific region (between positions 417 and 470) and that might have been generated by an interlocus gene conversion.CONCLUSION: Because the recombination region of sefus and the upstream recombination region of Sec1‐FUT2‐Sec1 are almost identical, this sequence stretch is likely to be the breakpoint for different kinds of recombinations that occur in this family of genes.
ABOtranscript levels in peripheral blood and erythropoietic culture show different allele‐related patterns independent of the CBF/NF‐Y enhancer motif and multiple novel allele‐specific variations in the 5′‐ and 3′‐noncoding regions
Authors: Thuresson Britt , Chester M. Alan , Storry Jill R. , Olsson Martin L. 
Published: February 2008

BACKGROUND:Mechanisms regulating theABOgene are unclear, especially in the hematopoietic compartment. The number of 43‐bp repeats in the CBF/NF‐Y‐binding enhancer region is considered to have a major influence on transcription.STUDY DESIGN AND METHODS:Transcript levels in peripheral blood and in erythropoietic culture of CD34+ cells from marrow donors were measured with TaqMan assays. The 5′‐regulatory region and 3′‐downstream sequences were investigated to determine if allelic variations occur.RESULTS:Surprisingly, transcripts fromA1andA2alleles could not be detected in peripheral blood, although transcripts fromB/O1/O1v/O2alleles were readily observed. Sequencing of approximately 4 kb upstream and 1.8 kb downstream of the coding region showed multiple novel allele‐specific and allele‐related motifs. No correlation between these sequence variations and transcript levels was found, however. Contradictory to the results with peripheral blood, in erythropoietic culture of CD34+ cells from healthy marrow donors transcripts fromA1andA2alleles were found at higher levels than transcripts fromB/O1/O1valleles.CONCLUSION:These data do not support previous suggestions that nonsense‐mutatedO1/O1vtranscripts are eliminated first. Furthermore, our results contradict the notion that the number of repeats in the upstream CBF/NF‐Y‐binding enhancer region, which contains four 43‐bp repeats inA2/B/O1/O1vbut only one 43‐bp unit inA1/O2alleles, determines the transcription rate. The reason for the remarkable discrepancy between blood and marrow remains to be elucidated.
Tranexamic acid reduces blood transfusion in total knee arthroplasty even when a blood conservation program is applied
Authors: Álvarez Juan C. , Santiveri Francisco X. , Ramos Isabel , Vela Enrique , Puig Lluis , Escolano Fernando 
Published: February 2008

BACKGROUND: In total knee arthroplasty surgery, a blood conservation program is applied as a normal clinical practice to avoid allogenic transfusions. The objective of this study was to assess the effectiveness of tranexamic acid to reduce transfusions in total knee replacement even when a blood conservation program is applied.STUDY DESIGN AND METHODS: In a double‐blind prospective study the patients scheduled for total knee arthroplasty were included in a well‐established blood conservation program and then randomly assigned into two groups: In tranexamic acid group, 10 mg per kg ev bolus followed by 1 mg per kg per hour perfusion was administered, while in the control group, saline was given matching the protocol.RESULTS: Ninety‐five patients were included (tranexamic acid group, 46; control group, 49). Thirty‐three patients (34.7%) underwent preoperative procedures to reduce transfusions: presurgical autologous blood donation (12), recombinant erythropoietin (6), and elementary iron (15); postoperative drain for reinfusion was allocated in all the cases. Total blood loss on the fourth postoperative day was [mean (±SD)] 1744 (±804) mL in controls compared with 1301 (±621) mL in the tranexamic acid group (p < 0.05). Eleven units of blood were transfused (6 patients) in the control group versus one in the tranexamic acid group (p < 0.05). Only 2 patients (4%) in the tranexamic acid group received reinfusion of blood recovered by drains compared with 36 (73%) in the control group (p < 0.0001). No thromboembolic complications were detected.CONCLUSION: Tranexamic acid reduces blood losses and transfusion requirements even when a blood conservation program was used and it questions the usefulness of the postoperative reinfusion drains.
Selection of hematopoietic stem cells with a combination of galactose‐bound vinyl polymer and soybean agglutinin, a galactose‐specific lectin
Authors: Yura Hirofumi , Kanatani Yasuhiro , Ishihara Masayuki , Takase Bonpei , Nambu Masaki , Kishimoto Satoko , Kitagawa Michihiro , Tatsuzawa Osamu , Hoshi Yasutaka , Suzuki Shinya , Kawakami Mitsuyuki , Matsui Takemi 
Published: February 2008

BACKGROUND: Selection of hematopoietic stem cells can be used to prevent graft‐versus‐host disease (GVHD) after allograft transplantation. The purpose of the study was to examine a novel cell separation system comprising a galactose‐bound vinyl polymer (Gal‐VP) and soybean agglutinin (SBA), a galactose‐specific lectin.STUDY DESIGN AND METHODS: A vinyl polymer (VP) containing α‐1,6‐ and β‐1,4‐linked galactose terminals was used to facilitate cell separation. A VP containing an α‐1,4‐linked glucose terminal (α‐1,4‐Glu‐VP) was also synthesized as a control for α‐1,6‐ and β‐1,4‐Gal‐VP. Peripheral blood samples were collected from healthy volunteers and umbilical cord blood cells were collected after normal labor.RESULTS: The sugar‐VP was adsorbed on the surface of various materials. In the presence of SBA, T lymphocytes bound to β‐1,4‐Gal‐VP–coated microbeads, but not to α‐1,4‐Glu‐VP–coated microbeads. When peripheral or cord blood cells were cultured on α‐1,6‐Gal‐VP–coated plates, most red blood cells, lymphocytes, granulocytes, and monocytes adhered to the plate in the presence of 300 mg per mL SBA, whereas few CD34+ cells attached, even with 800 mg per mL SBA.CONCLUSION: SBA binds selectively to blood cells by recognizing cell‐surface sugars, which are dependent on the extent of cellular differentiation. Therefore, the combination of α‐1,6‐Gal‐VP and SBA might be useful for separation of blood cells according to their stage of differentiation and lineage.
Evaluation of proposed FDA criteria for the evaluation of radiolabeled red cell recovery trials
Authors: Dumont Larry J. , AuBuchon James P. ,   Biomedical Excellence for Safer Transfusion (BEST) Collaborative
Published: February 2008

BACKGROUND: FDA requirements for recovery of radiolabeled red blood cells (RBCs) 24 hours after autologous reinfusion in normal subjects have evolved over time. This study defined the ability of currently available RBC systems to satisfy the most recently proposed criteria.STUDY DESIGN METHODS: RBC recoveries were collected from US laboratories participating in clinical trials for RBC systems that have received FDA approval. Data were stratified for analysis into liquid‐stored, gamma‐irradiated, and frozen components. With statistical software, 24 individual samples were randomly selected with replacement from each stratum, repeating this for 5000 sample groups per stratum, to simulate experimental outcomes for each population. The percentage of sample groups that passed each and all of the proposed FDA criteria was determined. This procedure was repeated for recovery success thresholds of 75, 70, and 67 percent.RESULTS: A total of 941 RBC recoveries were obtained from 11 laboratories and 34 studies performed between 1990 and 2006 for 12 sponsors. While the criterion for the mean was almost always satisfied, the standard deviation (SD) criterion was more problematic. Causing most failures was the success threshold definition. Changing the success threshold from 75 to 70 percent or 67 percent increased the likelihood of meeting the requirement for all RBC types.CONCLUSION: The probability of passing the FDA‐proposed criteria for currently FDA‐approved products was poor. Changing the success threshold for an individual RBC recovery from 75 to 67 percent resulted in improved ability to meet this criterion for all three RBC types. This change had no affect on the pass rates based on the mean and SD criteria.
pH value promotes growth of Staphylococcus epidermidis in platelet concentrates
Authors: Störmer Melanie , Kleesiek Knut , Dreier Jens 
Published: February 2008

BACKGROUND: The platelet (PLT) storage lesion is characterized metabolically by a pH value associated with lactic acid generation. PLT storage conditions support the growth of Staphylococcus epidermidis, the most common organism implicated in bacterial contamination of PLT concentrates (PCs). Here, different factors that influence bacterial growth in PCs are discussed and the relation between pH values of PCs and citrate plasma (CP) is studied, with emphasis on bacterial proliferation.STUDY DESIGN AND METHODS: The PLT lesion with regard to pH decrease and lactic acid production was monitored during storage and correlated to bacterial proliferation properties. A total of 115 coagulase‐negative staphylococci, especially S. epidermidis isolates, were characterized for their proliferation in different blood components (CP, buffy coat–derived, and apheresis PCs). Furthermore, the influence of donor‐specific, product‐specific, species‐specific, and strain‐specific factors on bacterial proliferation was investigated.RESULTS: PCs showed a lower pH value in comparison to plasma during storage. Bacterial proliferation in PCs and the failure to grow in CP were determined with all organisms tested. No correlation to donor‐specific, species‐specific, or strain‐specific factors was observed. Lowering the pH of CP resulted in bacterial proliferation, whereas a pH increase in the PC unit inhibited the proliferation of S. epidermidis.CONCLUSION: With emphasis on bacterial proliferation, the significant difference between PC and CP is the presence of metabolizing PLTs. The pH values of stored PLTs, but not those of stored plasma, support the growth of S. epidermidis.
Proficiency testing experience for viable CD34+ stem cell analysis
Authors: López María C. , Lawrence David A. 
Published: February 2008

BACKGROUND: Successful hematopoietic engraftment depends on the number of viable CD34+ stem cells. Therefore, accurate quantification of viable CD34+ stem cells is required.STUDY DESIGN AND METHODS: To evaluate clinical laboratory performance, the New York State Department of Health initiated proficiency testing (PT) for viable CD34+ stem cells. Preserved adult peripheral blood was spiked with preserved cord blood CD34+ stem cells and was shipped to the participating laboratories. Three educational and two graded PTs were performed by participating laboratories, and their results were analyzed for consistency. Comparative analysis of viability with 7‐aminoactinomycin D (7‐AAD) and ToPro‐3 dyes also was performed.RESULTS: Laboratories had to adapt their standard operating procedures to include a viability dye to quantify the number of viable CD34+ stem cells. The majority of laboratories chose 7‐AAD as their preferred viability dye, but propidium iodide (PI) and ToPro‐3 were used by two laboratories. Once all laboratories started to simultaneously analyze viability and staining for CD34, graded PTs started. Lower numbers of viable CD34+ stem cells were obtained for ToPro‐3 when the dye was compared with 7‐AAD.CONCLUSION: It is concluded that ToPro‐3 stains more cells than 7‐AAD and likely includes compromised cells. The use of new vital dyes, like ToPro‐3, that may stain preapoptotic cells could represent an important advance to improve the quantification of viable CD34+ stem cells, for engraftment purposes. Further studies are needed to document the benefits of switching to a method that excludes not only dead cells, but apoptotic cells as well.
N‐terminal pro‐brain natriuretic peptide is a useful diagnostic marker for transfusion‐associated circulatory overload
Authors: Tobian Aaron A.R. , Sokoll Lori J. , Tisch Daniel J. , Ness Paul M. , Shan Hua 
Published: February 2008

BACKGROUND: Transfusion‐associated circulatory overload (TACO) can be difficult to diagnose and distinguish from transfusion‐related acute lung injury (TRALI), but is a relatively common complication that occurs when increases in blood volume overwhelm the cardiovascular system. Brain natriuretic peptide (BNP) has been shown to be a functional marker for TACO. N‐terminal pro‐brain natriuretic peptide (NT‐proBNP) is another marker that could be more helpful than BNP since it has a longer half‐life in circulation and is also much more stable in laboratory samples. In this study, whether NT‐proBNP is a useful diagnostic marker for TACO was evaluated.STUDY DESIGN AND METHODS: Forty patients were enrolled into a case‐control study (16 patients with TACO and 24 control patients) and had pre‐ and posttransfusion NT‐proBNP concentrations evaluated from submitted type‐and‐screen blood samples.RESULTS: The sensitivity of elevated posttransfusion NT‐proBNP to diagnose TACO was 93.8 percent, the specificity was 83.8 percent, and the accuracy was 87.5 percent. Elevated posttransfusion NT‐proBNP is the only independent variable for the diagnosis of TACO based on multivariate logistic regression.CONCLUSION: NT‐proBNP is both a sensitive and a specific marker for TACO and can be helpful in confirming transfusion associated fluid overload. This study also demonstrates that many patients who experience TACO may already be in a state of excess volume. Clinicians should be aware that many asymptomatic patients have excess fluid and transfusion may cause these patients to become symptomatic.
Latitudinal Variation in Leaf and Tree Traits of the Mangrove Avicennia germinans (Avicenniaceae) in the Central Region of the Gulf of Mexico
Authors: Méndez‐Alonzo Rodrigo , López‐Portillo Jorge , Rivera‐Monroy Víctor H. 
Published: February 2008

ABSTRACTThe variation in leaf mass per area, leaf nutrients (% carbon, nitrogen and phosphorus), and the allometric relation between tree height and diameter of the black mangrove, Avicennia germinans, were explored in nine mangrove forests in similar environments along a 5° latitudinal gradient in the central region of the Gulf of Mexico, as indicated by a southward increase in temperature and precipitation. There was no correlation between leaf nitrogen or phosphorus content and latitude. Leaf mass per area and leaf carbon content were positively correlated with latitude and negatively correlated with temperature and annual rainfall, whereas asymptotic tree height and maximum diameter showed the opposite trend. Such patterns suggest a trade‐off between leaf traits and tree size which may be constrained by the same environmental factors along a dry‐cold to humid‐warm latitudinal gradient.
Decline of Mammal Species Diversity Along the Yungas Forest of Argentina
Authors: Ojeda Ricardo A. , Barquez Rubén M. , Stadler Jutta , Brandl Roland 
Published: February 2008

ABSTRACTThe southernmost extension of tropical Andean–Amazonian forests protrudes into the arid to semiarid habitats in northwestern Argentina. We analyzed the decline of species richness of forest mammals along these Yungas forests. In particular, we tested whether species decline is due to a general latitudinal effect and whether the drop of species from the assemblages was independent from species' traits and environmental variables. For these tests, we estimated the geographic range edges of 39 species of forest mammal and estimated the species richness with bands of 30′. First, we compared the slope of the decline of species richness from north to south (5.8 species/degree) with the decline expected from the latitudinal species gradient (1–3 species/degree). The decline in species richness of forest mammals along the Yungas was significantly steeper than expected. Second, with a null model assuming a random drop of mammal species we derived confidence limits for the expected species richness and number of range edges within the bands. None of the forest mammals reached the tip of the forest, in marked contrast to nonforest mammals. More range edges than expected from the null model fell within the bands 23°30′–24°00′ S and a band near the tip of the Yungas indicating a nonrandom drop of species. The correlation between vulnerability traits and range edges suggests that processes associated with the availability of resources influence the drop of species. We propose that a suite of macroecological attributes interacting with a decrease in habitat quality determines the pattern of species richness in the Yungas forest.