bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coronary Artery Damage Induces Endothelial Progenitor Cell Recruitment and High Levels of Circulating EPCs Correlate with Coronary Artery Collaterals Formation.
Authors: Lev Eli I. , Kleiman Neal S. , Birnbaum Yocahi , Harris David , Korbling Martin , Estrov Zeev 
Published: April 2020

Abstract
Endothelial progenitor cells (EPCs) are bone marrow-derived undifferentiated cells that are rapidly mobilized in response to tissue ischemia and incorporated into sites of neovascularization. EPCs co-express surface CD34, CD133 and vascular endothelial growth factor receptor-2 (VEGFR-2) antigens and develop an endothelial phenotype in culture. In animal models of tissue ischemia EPCs were shown to participate in angiogenesis and vasculogenesis. We sought to determine whether circulating EPCs level correlate with collateral formation following a non-ST segment elevation myocardial infarction (NSTEMI). In addition, we sought to evaluate the effect of percutaneous coronary intervention (PCI) on the levels of circulating EPCs. Twenty patients who underwent PCI within a week of NSTEMI were divided into two groups: patients without collaterals [coll(−), n=10] and patients with Rentrop grade 3–4 collaterals [coll(+), n=10]. Two blood samples were drawn from all patients: before PCI and 24±2 hours after PCI. Using flow cytometry the percentage of cells co-expressing VEGFR-2 and CD133 was determined. In addition, EPC colonies were grown from peripheral blood mononuclear cells, characterized, and counted after 7 days of culture. The clinical characteristics of the two groups were similar. The coll(+) group had a higher degree of culprit vessel stenosis and lower initial TIMI flow grade. The relative number of EPCs (co-expressing VEGFR-2 and CD133) before PCI was significantly higher in the coll(+) group than in the coll(−) group (1.49±0.9% vs. 0.77±0.4%, P=0.045). There were no significant inter-group differences in the number of EPC colony-forming cells. The number of EPC colonies increased significantly in the coll(−) group following PCI (from 9.5±4.8 to 14.0±5.9 per 106 cultured cells, P=0.01). This study supports an association between circulating EPC levels and collateral formation in patients with a NSTEMI. Furthermore, these findings suggest that vascular injury during PCI triggers mobilization of EPCs to the peripheral blood, especially in patients without coronary collaterals. Our data suggest that patients with high levels of circulating EPCs are more likely to form coronary artery collaterals and that vascular injury induces EPC recruitment.
A Method for Rapid Purification of Murine Siderocytes.
Authors: Martin Florent M. , Bydlon Gabriela , Welsh Megan L. , Friedman Jeffrey S. 
Published: April 2020

Abstract
Iron overload is a key contributor to the pathogenesis of multiple human disorders including the sideroblastic anemias. The specific iron compounds present in tissues or cells that are the targets of excess iron deposition remain poorly understood. Our objective is to further identify the composition of such iron aggregates. As there is evidence that some forms are magnetically active, we have developed a simple and specific method to purify iron-overloaded red blood cells using magnetic affinity columns. RBC derived from mice transplanted with SOD2-deficient hematopoietic stem cells served as a source of iron-laden cells (Friedman et al., Blood 2004; J. Exp. Med. 2001). Purification was based upon the observation that iron deposits in SOD2-deficient cells are magnetically susceptible and allow for retention of iron-laden cells in a strong magnetic field. Peripheral blood from SOD2-deficient chimeric mice was passed through magnetic separation columns; iron-overloaded cells were eluted and subsequently characterized by flow cytometry, western blot and microscopy. We were able to purify 3% of the total red cells as iron-laden siderocytes. More than 93% of the magnetically purified SOD2-deficient cells were identified as reticulocytes; they had numerous siderotic granules, produced enhanced reactive oxygen species levels, and showed increased protein oxidative damage, mitochondrial enrichment and mitochondrial membrane potential. Our method can be used to purify iron-laden cells as well as iron-associated subcellular fractions prepared from iron-loaded tissues, allowing elucidation of the structure, location and protein composition of such iron deposits. We believe that this data will help develop our understanding of the pathogenesis of sideroblastic anemia and other disorders characterized by iron overload.
Iron Deficiency and Vitamin B12/Folate Levels. A Case-Control Study.
Authors: Remacha Angel F. , Sardà Pilar , Royo Teresa , Fernández Nieves , Rojas Ester , Canals Carmen , Altés Albert 
Published: April 2020

Abstract
A number of cases with iron deficiency anemia (IDA) are associated with low vitamin B12 (LB12). However, LB12 is not synonymous with B12 deficiency. An increase in homocysteine (Hcy) or methylmalonic acid can differentiate cases with a real deficiency from those with apparently innocuous LB12. Our aim was to study LB12 and low red cell folate (LRCF) prevalence in IDA cases and to determine the existence of B12/folate deficiency. A prospective case-control study was carried out in patients with anemia consecutively admitted to our Hospital. The case group included 506 IDA patients (Hb &lt;115g/l, MCV &lt;98fl, serum ferritin &lt;20microg/l or soluble transferrin receptor &gt;5mg/l). The control group was made up of 117 patients with anemia of chronic disorders (ACD) (Hb &lt;115g/l, MCV 80-98fl, iron &lt;10micromol/l, total iron binding capacity &lt;40micromol/l, serum ferritin &gt;100microg/l and soluble transferrin receptor &lt;4mg/l). Serum B12 and RCF were evaluated in all cases and controls. Serum homocysteine was determined in those with B12 and/or RCF below percentile 10 (B12 &lt;200pmol/l, RCF &lt;590nmol/l). HyperHcy was considered when Hcy exceeded &gt;17micromol/l. Several variables were included in a multiple regression analysis to build a predictive model for IDA with LB12 and hyperHcy. LB12 was observed in 17.8% of IDA cases (87 cases), including 8.2% with B12&lt;150pmol/l (percentile 2.5). Interestingly, 60% of patients with B12 &lt;150pmol/l had hyperHcy and 48% of those with B12 between 150 and 200pmol/l. Low RCF was found in 6.3% (13 cases). All cases with RCF &lt;500nmol/l (percentile 2.5) showed hyperHcy and 50% of cases with RCF between 500 and 590nmol/l. LB12 was observed in 7 patients in the control group (5.4%) and LRCF in 10%. LB12 was more frequent in IDA than in ACD (p&lt;0.0001). The best predictive variable for IDA and LB12 with hyperHcy was age and the cut-off was 60 years (sensitivity: 91%). In summary, in our study 18% of cases with IDA showed LB12, and a high percentage had a real vitamin deficiency. Age was the main predictive factor. Thus, serum B12 should be determined in IDA patients over 60 years
Magnetic Ressonance Image T2* for the Evaluation of Iron Overload in Patients with Hereditary Hemochromatosis. A New Guide for the Indication of Therapeutic Phlebotomies.
Authors: Hamerschlak Nelson , Rosemberg Laercio , Parma Alexandre , Moreira Frederico R. , Fernanda Assir F. , Jose Kutner M. , Andreza Ribeiro A. , Marcelo Funari B. 
Published: April 2020

Abstract
Hereditary hemochromatosis is highly prevalent in those with northern European ancestry (1 in 8 individuals are heterozygous and 1 in 100 – 200 are homozygous). It is characterized by laboratory tests as ferritin &gt; 150 ng/mL, transferrine saturation &gt; 40% and HFE mutations (C282Y and H63D). Presently the indications for treatment (therapeutic phlebotomies, TP) are based solely on the ferritin levels. It is possible that patients with moderate or even high levels of ferritin do not have iron overload. Performing liver biopsies would be an option for the actual evaluation, though invasive and risky. A non-invasive method to evaluate this deposition would be helpful in order to determine which patients actually demand TP.
To evaluate if the use of Magnetic Ressonance Image (MRI) is a method for measuring tissue iron and could be a new guide for the indication of therapeutic phlebotomies, nineteen patients (mean age 43,47 y.o, +/− 9,85, gender = 16 male, 3 female) with hereditary hemochromatosis were scanned with T2- star (T2*) (GE equipment, Milwaukee, USA). The median of ferritin level was 594 (21–9300) The MRI method was previously validated to chemical estimation of iron in thalassemic major patients undergoing liver biopsies. The evaluated organs were liver and heart.
All patients were in normal range of myocardial T2*. The images of four patients (25%), showed liver iron deposition. Eleven patients who presented serum ferritin levels below 600 ng/ml showed no liver iron deposition. Just one among five patients (20%), who presented ferritin levels between 601 and 1000 ng/ml showed hepatic iron overload. The three patients with ferritin levels higher than 1000 ng/ml had liver iron deposition quantified using liver T2* MRI techique.
MRI T2* showed that some patients who would have an indication for TP based on laboratory tests, might avoid these procedures based on image results of internal organs. These patients can have an image follow up in order to decide when would be the appropriate time to start TP. This method can also be used to evaluate the efficacy of TP in patients who have already received this treatment. A larger group of patients would have to be evaluated in order to validate these results.
Anti-Angiogenic In Vivo Effect of Lenalidomide (CC-5013) in Myelodysplastic Syndrome with del(5q) Chromosome Abnormality and Its Relation to the Course of Disease.
Authors: Buesche Guntram , Dieck Stephanie , Giagounidis Aristoteles , Bock Oliver , Wilkens Ludwig , Schlegelberger Brigitte , Knight Robert , Bennett John , Aul Carlo , Kreipe Hans H. 
Published: April 2020

Abstract
Lenalidomide, a novel immunomodulatory drug (IMiD), is a multifunctional inhibitor of angiogenesis. Vascular endothelial growth factor (VEGF) and its receptor (KDR) are major regulators of angiogenesis, which plays a key role in the growth and progression of solid tumors and hematologic neoplasms, and increased plasma levels of KDR were correlated with a lower remission rate in patients with myelodysplastic syndromes (MDS).
From a total of 35 patients suffering from MDS with del(5q) and being treated within a multicenter trial on the efficacy of CC-5013, biopsies and aspirates from bone marrow taken before and 6 + 12 months after start of lenalidomide therapy were evaluated for the percentage of cells with del(5q), blast count, vascularization, and gene expression of VEGF and its receptor using cytologic, histopathologic, cytogenetic and molecular genetic methods. 20 patients with healthy marrow served as a control for normal marrow.
Before start of treatment, vascularity of bone marrow, measured as the total length of vessels within the marrow volume, was markedly increased in MDS exceeding that from normal marrow by a factor of 3.24 +/− 2.57 (P &lt; 0.00005). Increase of vascularity correlated with increase of VEGF gene expression, which exceeded that from normal marrow by a factor of 2.68 +/− 2.21 (P = 0.0003), whereas KDR gene expression was not significantly changed. During therapy with lenalidomide, vascularity markedly decreased to normal values in 60 % of patients (21 /35; P &lt; 0.00005). Normalization of vascularization correlated with a major cytogenetic response of disease (&lt; 35 % metaphases with del(5q); P = 0.0005) which occurred in 21 patients, 12 of them with a complete cytogenetic remission. Anti-angiogenic inefficacy of lenalidomide correlated with progression of disease (&gt;= 5 % blasts in blood or bone marrow; 14 patients; P = 0.0005). In contrast to vascularity, VEGF and KDR gene expression were not reduced during lenalidomide treatment. They increased in 8 (VEGF) and 12 (KDR) patients (P = 0.0005) independent of the cytogenetic response. Moreover, correlation between vascularity and VEGF gene expression disappeared, and an inverse correlation between KDR gene expression and vascularity occurred (P &lt; 0.00005).
We conclude that in MDS with del(5q), lenalidomide uncouples angiogenesis from the effect of VEGF resulting in a significant reduction of marrow vascularity followed by an increase in gene expression of VEGF and KDR. Inhibition of angiogenesis correlates with a significant reduction of the MDS clone in bone marrow whereas increase of vascularization indicates progression of disease.
Routine Blood Draw during Chemotherapy Does Not Cause Significant Iron Deficiency.
Authors: Fesnak Andrew , Mastoris Jason , Ley Susan , Henry David 
Published: April 2020

Abstract
Chemotherapy-related anemia in cancer patients can be significant. Frequent blood draws prior to and during chemotherapy treatment may result in a loss of iron (Fe) that could exacerbate or cause anemia. Therefore, phlebotomy for diagnostic testing has the potential to lead to significant Fe loss. We conducted a retrospective case study on 40 randomly selected patients currently undergoing chemotherapy. A CBC and routine chemistry resulted in blood losses of 9 ml and 13 ml respectively. If an infusaport was used, an additional 10 ml was drawn and discarded. Blood loss was recorded for each visit during a chemotherapy course of some 4–6 cycles. Approximately 1 ml of compacted red blood cells is equivalent to 1 mg of Fe. Therefore, by multiplying the hematocrit (HCT) by the blood loss (ml), the amount of iron loss (mg) was determined for each patient visit. Fe losses for the patients in this study were compiled and averaged by gender (M/F), by method of access (port/IV), per cycle of chemotherapy and overall. The average overall loss of Fe during a course of chemotherapy was 45.7 mg. Female patients lost an average of 39.9 mg Fe, while male patients lost an average of 53.7 mg Fe, probably because of higher average HCTs in men. As expected, patients with infusaports lost more Fe (76.9 mg Fe/course) than patients with peripheral intravenous access (30.7 mg Fe/course). Correcting for variability in the number of cycles per course of chemotherapy revealed an average loss of 10.3 mg Fe per cycle of chemotherapy. The impact of Fe loss on a patient’s overall hematological condition is dependent on many factors. If a patient is initially Fe deficient, an additional loss of Fe will have a greater effect than if the patient has sufficient iron stores. For example, an Fe loss of 50 mg in an Fe replete patient (approx. 3000 mg Fe) versus an Fe deficient patient (approx. 1500 mg Fe) would only account for a 1.67% or 3.33% loss respectively. This loss is not likely to result in Fe restricted erythropoiesis. Therefore, the Fe loss due to diagnostic phlebotomy in chemotherapy patients is unlikely to cause significant Fe deficiency.
Modulation of Iron Homeostasis during Erythroid Differentiation Is Mediated by Complementary Transcriptional and Post-Transcriptional Mechanisms.
Authors: Samara Maria , Chiotoglou Ioanna , Likousi Sophia , Kollia Panagoula 
Published: April 2020

Abstract
Iron is essential for cell proliferation, heme synthesis and a variety of cellular metabolic processes. Transferrin receptors (TfR)-1 and -2, ferritin and DMT1/Nramp2 are critically implicated in iron homeostasis. In this study, we evaluated TfR1/TfR2 (both alpha and beta isoforms), ferritin H-/-L-subunit and DMT1/Nramp2 mRNA expression as well as TfR1 protein expression in a model system of human erythropoiesis in an attempt to understand mechanisms critically involved in iron metabolism during normal erythroid maturation. CD34+ erythroid precursors collected from peripheral blood samples of normal individuals were cultured in free serum StemSpan medium in the presence of stem-cell factor (SCF, 100ng/ml) and erythropoietin (4u/ml). Real-time quantitative RT-PCR analysis showed that TfR1 mRNA levels increased significantly during cell proliferation and erythroid maturation (4–7-fold over days 4–12); in contrast, TfR2-alpha mRNA transcripts were low at the proerythroblast stage, then showed a slight increase (1.2–1.3-fold over days 4–12) and eventually remained stable up to terminal differentiation. TfR2-beta mRNA levels were generally low and did not fluctuate significantly throughout erythroid differentiation. TfR1 and TfR2-alpha mRNA stability was analyzed in cultures exposed to actinomycin-D (actD: 5μg/ml) for 24 and 48hrs on day 8 of culture (proerythroblast stage). The levels of both TfR1 and TfR2-alpha mRNA transcripts increased by 2.0–3.0-fold in actD-treated-CD34+ cells. Western blotting experiments were performed with an anti-TfR1-specific antibody on lysates derived from CD34+ cells throughout erythroid differentiation (days 3–14 of culture); in all experiments, actin served as control. Quantitative gel-banding densitometry was performed using Epson GT-8000 Laser Scanner. A significant increase of TfR1 protein was observed during erythroid maturation (from day 3 up to day 9), whereas a gradual decrease was observed after day 12 of culture. Assessment of H- and L-ferritin mRNA content at different stages of erythroid maturation demonstrated slightly higher levels of H-ferritin, albeit without significant changes throughout erythroid maturation. Similar results were obtained for DMT-1/Nramp-2 mRNA. These findings suggest that:
TfR1 upregulation starting from early erythroid stages and ongoing throughout erythroid maturation is mediated via transcriptional and post-transcriptional mechanisms, especially at more advanced differentiation stages; TfR2-alpha expression is uniformly low throughout erythroid differentiation and regulated by both transcriptional and post-transcriptional mechanisms.
These observations suggest that increased iron demands of developing erythroid cells might be met by increased TfR-1 expression, in a context of high TfR-1 mRNA transcripts with increased stabiliy at more advanced maturation stages.
No Significant Molecular Response in Polycythemia Vera Patients Treated with Imatinib or Interferon alpha.
Authors: Jones Amy V. , Higley Katherine , Curtis Claire , Kreil Sebastian , Zoi Katerina , Hochhaus Andreas , Reiter Andreas , Oscier David , Merber Alec , Silver Richard T. , Cross Nicholas C.P. 
Published: April 2020

Abstract
Imatinib mesylate and interferon alpha (rIFNa) have both been reported to induce remission in patients with polycythemia vera (PV), but until recently it has not been possible generally to gauge the depth of these responses due to the absence of a specific cytogenetic or molecular marker of the disease. Here we have used ARMS and pyrosequencing assays to detect and quantify the V617F JAK2 mutation in granulocytes or mononuclear cells from 111 PV patients, of whom 14 were undergoing treatment with imatinib (300–800 mg/day; median follow up 17 months; range 5–31), seven were undergoing treatment with rIFNa (dose range from 2MU three times/week to 3MU/day; median follow up 60 months; range 13–132), and 90 were untreated or treated only by phlebotomy, hydroxyurea or anagrelide (control group). Clinical responses in the 14 imatinib treated cases were none (NR; n=3), partial (PR; n=9) or complete (CR; n=2); responses in the seven rIFNa treated cases were PR (n=1) or CR (n=6). The V617F mutation was detected in all cases undergoing treatment with imatinib or rIFNa and in 82 (91%) of the control PV cases. The median percentage of mutated JAK2 alleles (%V617F) did not differ significantly between the imatinib treated cases (median 59%, range 8–91), the rIFNa treated cases (median 27%, range 19–87) or the V617F positive cases from the control group (median 53%, range 5–100). In the imatinib group, the median %V617F for cases with NR, PR and CR were 72% (44–89; n=3), 60% (30–91; n=9) and 15% (8 and 21; n=2), respectively. In the rIFNa treated group the single case with a PR had 87% V617F compared to a median of 26% (19–39) for the six cases in CR. Pretreatment samples were available for 9 of the imatinib treated cases. Of these, all seven of the NR or PR cases showed a marginal increase (median 1.2 fold, range 1.0–1.5) in the percentage of V617F alleles on treatment. In contrast, the two CR patients showed a 2–3 fold reduction in %V617F on treatment. We conclude that although PV patients may benefit from treatment with imatinib or rIFNa, molecular analysis indicates that responses are modest.
Activated JAK2 Signaling in Primary Human Hematopoietic Cells Drives Erythropoietin-Independent Erythropoiesis and Myelofibrosis.
Authors: Kennedy James A. , Barabe Frederic , Barber Dwayne L. , Dick John E. 
Published: April 2020

Abstract
An activating mutation in the JAK2 tyrosine kinase has recently been identified in patients with polycythemia vera (PV), essential thrombocythemia (ET) and idiopathic myelofibrosis (IMF). However, at this time, evidence of a causative role for activated JAK2 signaling in the pathogenesis of these myeloproliferative disorders is limited. Given that these are clonal stem cell diseases, the impact of deregulated JAK-STAT signaling must be considered in the context of primitive human hematopoietic cells. To this end, a lentiviral vector encoding the TEL-JAK2 (5–19) fusion was employed to infect lineage-depleted human cord blood, resulting in constitutive activation of STAT5 as well as the ERK and PI-3 kinase signaling pathways. Interestingly, when grown in culture under conditions that normally support the exclusive production of cells from the granulopoietic and monocytic lineages, cells expressing TEL-JAK2 underwent a burst of erythropoietin (EPO)-independent erythropoiesis; an outcome that could even occur in serum-free media in the absence of supportive cytokines. Furthermore, TEL-JAK2 cells exhibited erythroid colony-forming capacity in the absence of exogeneous EPO, a hallmark of PV. In order to gain insight into the in vivo effects of activated JAK2 signaling, transduced cord blood cells were injected intrafemorally into sublethally irradiated NOD/SCID mice. When animals were sacrificed 3 weeks post-transplant, the percentage of human engraftment was comparable between TEL-JAK2 and control animals; however, total cellularity was significantly reduced in the injected femur of TEL-JAK2 mice. At 9 weeks post-transplant, this reduction in cellularity was noted not only in the injected femur, but also in distant marrow cavities. Histological examination of the bone marrow from TEL-JAK2-transplanted mice showed a decrease in cellularity, the presence of an atypical megakaryocyte population, and patent sinusoids. Most notably, reticulin staining revealed the existence of a fibrous network in the bone marrow of TEL-JAK2 mice, indicative of myelofibrotic change. Taken together, these in vitro and in vivo studies provide functional evidence that in human hematopoietic cells, activated JAK2 signaling can initiate disease processes bearing similarity to both PV and IMF. Furthermore, they provide the first example of an experimental xenotransplant model of IMF which can be utilized to provide insight into both the pathogenesis of this disease and potential therapeutic targets.