bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Animal Model Suitable for Predicting In Vivo Behavior of Platelets in Humans: A Tool for New Product Development.
Authors: Blajchman Morris A. , Li Junzhi , Kulczycky Myron , Woskowska Zofia , Pieters Henry , Roodt Jan , Badenhorst Philip , Crookes Robert , Heyns Anthon , Goodrich Raymond 
Published: October 2019

Abstract
Testing platelet in vivo activity in an animal model remains an attractive approach for the pre-clinical evaluation of platelets that have been treated or manipulated by a new technology or product. Mirasol PRT™ is a novel pathogen reduction technology based on riboflavin photochemistry for the safety of blood component transfusion. In this study, rabbit platelets were tested for viability after exposure to 2, 3 and 5 J/cm2 of UV light in the presence of 50 μM riboflavin in a polypropylene bag (Sangewald). In order to minimize the potential variations caused by different isotope labeling and by individual rabbit differences, a pool of platelets was split into two for the treatment and control groups. Eight to ten rabbits were used in each group as recipients for each dose of light. Half of the rabbits in the group received concurrent injections of 111In-labeled PRT treated platelets and 51Cr-labeled control platelets. The other half received 51Cr-labeled PRT-platelets and 111In-labeled control platelets. The recovery and survival times were determined post-infusion for both treated and control platelets using the multiple hit model (γ-function) and data from the various groups were pooled and analyzed. The platelets treated with 2, 3 and 5 J/cm2 retained recoveries of 63.2% (SD=17, n=9), 55.3% (SD=10.8, n=10) and 44.0% (SD=12.8, n=8) of control platelets, respectively. The survival times of the platelets treated with 2, 3 and 5 J/cm2 were 59.5% (SD=15.7, n=9), 60.1% (SD=19.5, n=10) and 55.1% (SD=18.1, n=8) of control, respectively. Both values of recovery and survival times were correlated with UV light dose with correlation coefficients of 0.90 (r2) and 0.73 (r2) respectively. In a subsequent single site human clinical study, human platelets were treated with UV light at a dose of 3 J/cm2 in a Sangewald bag, radiolabelled with Indium at day 5 of storage and infused into autologous subjects. Recovery and survival values for these subjects were obtained. At a dose of 3 J/cm2, recovery and survival activities retained 54.9% (SD=3.1, n=4) and 71.7% (SD=21.5) of control platelets, respectively. Good agreement with observations made in the rabbit model was thus obtained. Based on this work, a light dose was selected for standard treatment of human platelets using the Mirasol PRT system. In conclusion, this kinetic study on UV light dose in an animal model was predictive of human platelet in vivo activity, making it a potentially valuable model for estimating human clinical trial outcomes for new platelet storage and treatment methodologies.
An Increase in the Immature Platelet Fraction Predicts Reconstitution of the Platelet Count and May Reduce Prophylactic Platelet Transfusions after Stem Cell Transplantation.
Authors: Machin Samuel J. , Hart Dan , Kunka Stefan , Briggs Carol , Corash Laurence 
Published: October 2019

Abstract
A new automated method to reliably quantitate reticulated platelets, expressed as the immature platelet fraction (IPF), has been developed on an automated cell counter (XE-2100, Sysmex). The IPF is identified by flow cytometery using a polymethine dye, staining platelet RNA, in the reticulocyte channel; the results are available at the same time as the CBC. The IPF normal range is 1.1–6.1%, mean 3.4%, 2 SD 2.3%. Reproducibility and stability results over 48 hours were acceptable. The IPF is raised when there is increased peripheral consumption/destruction. In untreated idopathic thrombocytopenic purpura, n = 12, mean 22.3%, range 9.2–33.1% and active thrombotic thrombocytopenic purpura, n = 5, mean 17.2%, range 11.2–30.9%. Patients who may require prophylactic platelet transfusion, usually at threshold counts less than 10 x 109/L, to support periods of marrow aplasia were monitored daily for platelet count and IPF%. The recovery phase of thrombocytopenia in most chemotherapy (n=13) and stem cell/bone marrow transplant patients (n=15) was preceded by a rise in IPF% several days prior to platelet recovery, mean IPF 13.7%, range 7–27.3%. In particular, patients undergoing autologous transplantation (n=8) using peripherally collected stem cells have a very characteristic IPF% motif, with a rise 1 day prior to engraftment for all patients except one where it was 2 days prior. For bone marrow derived transplant patients the increase in IPF was more variable, the rise preceded the rise in platelet count by 2–7days. These patients suffer more septic episodes where there is a rise in the IPF with no immediate increase in the platelet count, and require more regular platelet transfusions. Following a platelet transfusion there is a 24-hour transitory fall in the IPF response, which may impede platelet recovery. A parameter that could predict the timing of platelet recovery could be used clinically to reduce the use of prophylactic platelet transfusion in these patients, thus minimising donor exposure, infection risk and allowing substantial financial savings. The IPF is a useful parameter in the evaluation of the thrombocytopenic patient and has the potential to allow more optimal transfusion of platelet concentrates.
Platelet Transfusions in a Medical- Surgical Intensive Care Unit.
Authors: Arnold Donald M. , Molnar Laura A. , Crowther Mark A. , Sigouin Christopher , Carruthers Julie , Heddle Nancy M. , Cook Deborah J. 
Published: October 2019

Abstract
Background: The benefits and harms of platelet transfusions in critically ill patients are unclear.
Objectives: To describe the frequency of, indications for, and effects of platelet transfusions in patients admitted to a medical- surgical intensive care unit (ICU).
Design: Single center cohort study (January 2001 to January 2002).
Methods: We identified all patients who developed thrombocytopenia (platelet count <150 x 109/l) during their ICU admission from a prospective study which enrolled consecutive adults admitted to ICU with an expected length of stay ≥72 hours, and which excluded patients with trauma, orthopedic surgery, cardiac surgery, pregnancy, or receiving palliative care. Retrospectively, using a priori criteria, bleeding severity and the indications for platelet transfusions were assessed; 23.7% of bleeding events and 89.5% of transfusion indications were reviewed in duplicate independently. Initial agreement was calculated using Cohen’s unweighted kappa and all assessments of bleeding severity and transfusion indications were adjudicated by third person.
Results: Of 261 ICU patients, 118 (45.2%) had thrombocytopenia. Initial agreement between primary reviewers for assessments of bleeding severity was good (k= 0.69), and for indications for platelet transfusions was poor (k=0.35); consensus was achieved in all cases. One third of thrombocytopenic patients had major bleeding (37/118, 31.4%), and one fifth had minor bleeding (24/118, 20.3%). Among thrombocytopenic patients, 27/118 (22.9%) received a total of 76 platelet transfusions, 24 (31.6%) of which were administered to treat bleeding, and 52 (68.4%) of which were to prevent bleeding. Of the prophylactic platelet transfusions, 18/52 (34.6%) preceded invasive procedures. The mean ± SD platelet count prior to therapeutic platelet transfusions was 54 ± 40 x109/l; for peri-procedural transfusions, 55 ± 38 x109/l; and for other prophylactic platelet transfusions, 37 ± 21 x109/l. Most transfusions (69/76, 91%) were administered as pools of 5.2 ± 1.2 random donor platelets, and few (7/76, 9.2%) were apheresis platelets. A single platelet transfusion (pool of 5 random donor units or 1 apheresis unit) resulted in a platelet increment of 14 ± 29 x109/l at 6.6 ± 5.9 hours following transfusion. No rise in platelet count was observed following 17 transfusions given to 13 patients.
Conclusions: Platelet transfusions are frequently administered to thrombocytopenic critically ill patients, and, although the indication is not always clear, the most common reason is to prevent bleeding. Nearly half of transfused ICU patients were refractory to one or more platelet transfusion. Further prospective studies are needed on the indications for, and effects of, platelet transfusions in the ICU setting.
Treahlose Loaded, Freeze-Dried Rehydrated Human Platelets Maintain and Regulate Their Intracellular pH.
Authors: Tablin Fern , Tang Minke , Walker Naomi J. , Crowe John H. 
Published: October 2019

Abstract
Maintenance of intracellular pH, a critical cellular function, is required for generation of proton gradients and platelet response to agonist. Previously, we have demonstrated that freeze-dried rehydrated platelets are able to respond to agonists generate a rise in intracellular calcium (Auh et al. 2004 Calcium mobilization in freeze-dried platelets. Cell Preservation Technology in press) and maintain normal membrane and protein secondary structure (Wolkers et al. 2002 Towards a clinical application of freeze-dried platelets. Cell Preservation Technology 1:175–188). As part of our ongoing studies of trehalose loaded freeze-dried rehydrated human platelets we examined their ability to maintain their intracellular pH. Platelet proton regulation is achieved through the Na-H exchanger (NHE1) which is dependent on the concentration of extracellular sodium. Freeze-dried and fresh control human platelets were loaded with the pH ratio dye bis-carboxyfluorescein acetomethyl ester (BCECF-AM), washed over a Sepharose 2B column and examined by fluorescence spectroscopy. Fresh and freeze-dried rehydrated human platelets maintained virtually identical resting intracellular pH, 7.273 +/− 0.015, and 7.270 +/− 0.034 respectively. Both cell types responded to increased extracellular sodium by increasing their pH in a virtually identical manner. The addition of 0.5U/ml thrombin (in the presence of 135 mM NaCl) resulted in an initial acidification and subsequent alkalinzation of both fresh and freeze-dried rehydrated cells. Prior to the addition of thrombin both cell populations had an [pH]i of 6.9, while after thrombin stimulation the pH rose to 7.012 for fresh cells and 7.001 for freeze-dried rehydrated cells. Thrombin stimulation in the absence of extracellular sodium resulted in a significant acidification of both cell populations to a final pH of 6.6 for fresh cells and 6.7 for freeze-dried rehydrated cells. Specific inhibition of the NHE1 transporter by 5-(N-methyl-N-isobutyl) amiloride (MIA) completely abolished the response of all cells to increasing concentrations of sodium. In the parallel control experiment both freeze-dried and fresh cells acidified to pH 6.2 and incubated with 135mM NaCl responded by generating a rise in intracellular pH to 7.1. These results demonstrate that freeze-dried rehydrated platelets are able to maintain normal pH homeostasis and respond to agonist in a specific manner. Studies funded by DARPA.
Plasma Cell Folate Receptor Overexpression Differentiates Multiple Myeloma from Monoclonal Gammopathy of Undetermined Significance and Smoldering Myeloma.
Authors: Greipp Patricia , Cascino Greg , Kimlinger Teresa , Rajkumar Vincent , Prendergast Franklyn G. , Fonseca Rafael , Bergsagel P. Leif , Low Philip S. , Greipp Philip R. 
Published: October 2019

Abstract
Background: Folate receptor (FR) is a recently recognized tumor marker that is being investigated for targeted delivery of drugs, imaging of cancer cells, and tumor immunotherapy. The small size of the molecule, simple conjugation chemistry and lack of immunogenicity make folate an ideal candidate for targeted delivery to tumors bearing the FR (Lu Y, Low PS. Folate-mediated delivery of macromolecular anticancer therapeutic agents. Adv Drug Deliv Rev. 2002 Sep 13;54(5):675–93). FR is overexpressed in 90% of ovarian cancers and in other human tumors including endometrial, colorectal, breast, and neuroendocrine carcinomas, it is negatively or only weakly expressed in most normal tissues including some myeloid cells. In view of the above we wished to learn if overexpression of FR by marrow plasma cells (PC) might differentiate MM from MGUS and SMM.
Methods: We obtained marrow biopsy sections from 20 patients each with MM, MGUS, or SMM, and 11 normals and stained them by immunohistochemistry using a FR-beta antibody. Expression was graded 0 (negative), 1 (equivocal), 2 (positive) or 3 (strong positive) based on immunohistochemical staining of marrow PC. We recorded the percent PC, percent positive PC, and the staining of other cell types including myeloid, erythroid, lymphocytes, macrophages, megakaryocytes and control tissues.
Results: PC of patients with MM positively expressed FR compared to MGUS, SMM and normal PC (p<0.0001) (Figure 1 and 2). Of interest, 6 of 20 SMM patients showed positive expression. Maturing myeloid cells were also positive, acting as internal positive controls. Macrophages were often positive; some endothelial cells were positive; early erythroid precursors were rarely positive; megakaryocytes, maturing erythroid precursors and lymphocytes did not express FR. The chromosomal location of the FOLR gene cluster is 11q13. Gene expression arrays of purified PC failed to show evidence of overexpression of FOLR1, FOLR2, or FOLR3. We are currently performing Western blots to examine levels of protein product of purified PC.
Conclusion: Immunohistochemistal studies show differential expression of FR in MM PC compared to absent or equivocal expression in MGUS and normal PC and variable expression in SMM. The data suggest that FR may be used as a diagnostic tumor marker and has implications for development of folate-based tumor imaging, drug delivery, and immunotherapy.
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Symptomatic and Indolent Waldenström’s Macroglobulinemia Display Different Biological and Cytogenetic but Not Immunophenotypic Characteristics.
Authors: Ocio Enrique M. , Mateo Gema , Vidriales Belen , Lopez-Berges Consuelo , Gutierrez Norma C. , Hernandez Jesus M. , Sanchez-Guijo Fermin M. , Moro Maria J. , Hernandez Jose , Fernandez-Calvo Javier , Garcia-Frade Javier , Orfao Alberto , Miguel J.F. San 
Published: October 2019

Abstract
Waldenström’s Macroglobulinemia (WM) patients are classified in two main subtypes: symptomatic and asymptomatic. In this study we have analyzed the clinical, biological, immunophenotypical and cytogenetic characteristics of 85 WM, including 59 symptomatic WM (SWM) and 26 indolent WM (IWM).
Clinical behaviour of SWM, as expected, was clearly different from that of IWM. Characteristics of the first group included: poor performance status (30%), hyperviscosity syndrome (19%), B symptoms (29%) and neurological symptoms (25%). None of these features were present in IWM.
Regarding biology, most SWM patients (75%) had hemoglobin levels below 12 g/dl while only 8% of IWM showed this feature (p<0.001). Beta2 microglobulin and ESR were significantly higher in SWM than in IWM (3.6 vs 2.3 p=0.008, and 103 vs 62 p<0.001, respectively) and both entities also differed in albumin (3.5 vs 4 p=0.009) and IgM levels (3.4 vs 2.1 p=0.005). Although lymphoid infiltration was higher in SWM, differences did not reach statistical significance (47% vs 34% p=0.06). BM infiltration was predominantly interstitial in IWM (91%) whereas only 44% of SWM had this pattern (p=0.06). Interestingly, SWM patients had higher plasma cell (PC) bone marrow infiltration (2.6% vs 1.5% p=0.006) and a higher proportion of SWM patients showed evidence of mast cells (66% vs 28% p=0.009).
Immunophenotypic characteristics of B cells in SWM and IWM were almost identical, with only slight, but non significant, differences in some markers. The proportion of patients expressing CD27, strong CD24 and bcl-2 were greater in SWM than in IWM (42% vs 28%, 28% vs 17%, and 73% vs 61%, respectively). It should be noted that the frequency of these three markers was even lower in 15 MGUS patients analyzed (18%, 10% and 45% respectively), pointing out to a progressive decrease in expression from SWM to MGUS. Regarding PC, although their number was significantly higher in SWM than in IWM no differences were observed in their immunophenotypic pattern.
Cytogenetic profile was clearly different in SWM as compared to IWM. Thus, 10 out of the 59 SWM (17%) showed chromosomal abnormalities: 8 patients had 6q deletions and 2 patients IgH translocations, while none of the IWM cases displayed 6q deletions. In fact, only 2 out of 26 (8%) IWM showed cytogenetic aberrations: 1 case had IgH translocation and 1 case RB deletion. These results suggest that 6q deletion is associated with a more aggressive course of disease.
In summary, our results show that the different clinical and biological picture of SWM and IWM is associated with a different cytogenetic but not immunophenotypic profile.
Gain of von Willebrand Factor Binding Function Induced by a Mutation within the Leucine-Rich Repeat Region of Platelet Glycoprotein Ibα.
Authors: Peng Yuandong , Shrimpton Corie N. , Lopez Jose A. 
Published: October 2019

Abstract
The first step of platelet adhesion to areas of vessel injury is carried out by the platelet glycoprotein (GP) Ib-IX-V complex, which binds von Willebrand factor affixed to the subendothelial matrix. The GP Ib-IX-V complex comprises four polypeptides, each belonging to the leucine-rich repeat (LRR) family of proteins. Glycoprotein Ibα is the largest of these and contains the VWF binding site within a ~300-amino acid domain at its N-terminus that contains 8 tandem LRRs. In this study, we investigated the role in VWF binding of charged residues in this region of GP Ibα that are conserved across three species: humans, dogs and mice. Each of eleven charged residues was converted to Ala: His37, Glu40, Asp83, His86, Asp106, Glu128, Lys137, Lys152, Glu162, Asp175 and Lys189. All of the GP Ibα mutants expressed normally on the surface of CHO bIX cells, which stably express GP Ibb and GP IX. GP Iba expression was detected by the monoclonal antibody WM23, which binds a region uninvolved by the mutations. In three mutants, His86Ala, Glu128Ala, and Asp175Ala, the mutations appeared to induce large conformational changes, as they markedly altered the binding of the antibodies AN51 and SZ2, with epitopes located N-terminal and C-terminal to the LRRs, respectively. As a result, cells expressing the mutants Glu128Ala and Asp175Ala were unable to adhere to the surface when perfused over immobilized VWF. By contrast, cells expressing mutant His86Ala adhered to the surface and rolled on it much more slowly than did cells expressing wild-type GP Ibα. The His86Ala cells also displayed a left-shifted VWF binding curve in the presence of ristocetin compared to the wild-type cells. We investigated this residue further by converting the His to Glu, a residue of opposite charge. Cells expressing the His86Glu mutant rolled even more slowly over a VWF surface than the His86Ala cells at 20 dynes/cm2, but not at 2.5 dynes/cm2. Previously, mutations of GP Ibα causing gain of VWF-binding function have been confined to the disulfide loop formed by a bond between Cys209 and Cys248, which lies immediately C-terminal to the LRR region of GP Ibα. This is the first report of a gain-of-function phenotype due to a mutation in the LRR region of GP Ibα. Since His86 is more than 20 Å away from the major region of GP Ibα in direct contact with VWF defined by published crystal structures, our data suggests that the leucine-rich repeats regulate the affinity for VWF through long-range allosteric alterations of GP Ibα structure.
Ex Vivo Treatment of Erythroid Cells with Glycolytic Intermediates for Metabolic Correction of Pyruvate Kinase Deficiency.
Authors: Kanno Hitoshi , Aisaki Ken-ichi , Hamada Takako , Okada Shin-ichi , Fujii Hisaichi 
Published: October 2019

Abstract
Glycolysis is an essential metabolic pathway for survival of red blood cells (RBC), and mutations in the RBC-type of pyruvate kinase (R-PK) cause hereditary non-spherocytic hemolytic anemia. We have shown that R-PK deficiency induced apoptosis in erythroid progenitor cells (Blood96:596a, 2000; Am J Hematol74: 68, 2003). In this study, we examined whether ex vivo treatment of erythroid cells with high concentration of glycolytic intermediates ameliorated apoptosis of R-PK deficiency. For this purpose, we used the R-PK deficient Friend erythroleukemic cell, SLC3, which has been established from a mice model of R-PK deficiency (Jpn J Cancer Res90: 171, 1999). SLC3 and a control Friend cell were cultured with 0, 1, 3, and 5mM phosphoenolpyruvate (PEP) or pyruvate (PA). Supplementations of either PEP or PA resulted in about 2-fold accumulation of intracellular PA; however, ATP concentration was not significantly changed. Flow cytometric analysis showed that 24-hours treatment with 5mM PEP significantly reduced annexinV (+)/PI (−) cells. These data suggested that exogenously supplemented glycolytic intermediates increased intracellular PA concentration, resulting in amelioration of erythroid apoptosis. We have shown that a glutathione precursor, N-acetyl cysteine, reduced apoptosis of SLC3. Several studies revealed that PA, which effectively maintained the redox state and also prevented the loss of intracellular antioxidants, antagonized the apoptotic cell death. Taken together, oxidative stress caused by decreased supply of PA might account for erythroid apoptosis due to R-PK deficiency.