bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Frequency CD4+CD25+ Treg Cells in Nasopharyngeal Carcinoma Is Associated with Suppression of CD8 T Cell Mediated Response to Latency II EBV Antigens.
Authors: Chen Frederick E. , Wen Wensheng , Huang Guangwu , Travers Paul , Dodi I. Anthony , Madrigal J. Alejandro 
Published: October 2019

Abstract
Nasopharyngeal Carcinoma (NPC) is associated with latent Epstein Barr Virus (EBV) infection and expression of EBV latent antigen LMP2. Because of the possibility of targeting viral antigens, there is interest in developing EBV-LMP2-specific Cytotoxic T lymphocyte (CTL) immunotherapy for NPC. However, evidence suggests that CD8+ T cell responses to EBV latency II antigens are rarely detectable in these patients. Regulatory T cells have been shown to inhibit stimulation of CD8+ T cells by Antigen Presenting Cells (APC) in vitro, and may play an important role in immune tolerance to tumours. Thirteen newly diagnosed untreated HLA A2 NPC patients were investigated for CTL responses to EBV latency II antigens by flow cytometry using HLA A2 restricted tetramers specific for LMP2a derived peptides (CLG, LTA). No LMP2-specific CD8+ T cells were detected amongst peripheral blood CD8+ T cells either ex vivo or in vitro following short stimulation in ELIspot assays, although strong responses to CMV and flu peptides and PHA were elicited. To investigate the antigen presenting capability of professional APC in NPC, dendritic cells (DC) were generated from ex vivo peripheral blood monocytes and shown to express a stimulatory mature phenotype with expression of CD83 and markers of costimulation CD80 and CD86. Despite this, mature DC pulsed with LMP2 derived peptides failed to stimulate and expand autologous LMP2-specific CTL, suggesting either absence or tolerance of LMP2-specific CTL. CD4+CD25+ regulatory cells have been implicated in peripheral tolerance and inhibition of antigen-specific T cell responses, and analysis of ex vivo peripheral blood T cells from NPC patients showed increased CD25 expression constituting a mean of 22.23 % of total CD4+ T cells compared to normal control mean of 5.35% (student t-test p<0.001). CD25 was not expressed by non-CD4+ T cells including CD8+ and NK cells, indicating that CD25 expression was unlikely to have represented activation. The findings suggest that CD4+CD25+ regulatory cells may play an important role in inhibiting antigen-specific anti-tumour responses in patients with established disease.
Leukemia during Pregnancy: 32 Cases from a Single Institution.
Authors: Alhejazi Ayman , Aljurf Mahmoud , Sahovic Entezam , Almhareb Fahed , Maghfoor Irfan , Alsharif Fahad , Alzahrani Hazzaa , Alomar Hamad , Alshanqeeti Ali , Albeihani Amal , Zaidi Syed , Chaudhri Naeem 
Published: October 2019

Abstract
In an attempt to evaluate the outcome of leukemia during pregnancy we performed a study of all such cases identified in our institution leukemia database. Thirty two cases were identified as cases of leukemia during pregnancy among the cohort of patients treated between January 1991 and July 2003. The cases were AML (15), ALL (6) and CML (11).
At diagnosis the median age was 24.5 years and the median gestational age was 16 weeks. Twenty patients were treated for their leukemia during pregnancy at a median gestational age of 20 weeks (4 in the first trimester, 8 in the second trimester and 8 patients in the third trimester).
Among the acute leukemia patients (n=21), 10 patients (47.6 %) received chemotherapy during pregnancy, 9 (90%) of them achieved CR and one patient needed salvage chemotherapy. Of these 10 patients, 7 had normal live births, one spontaneously aborted at 15 weeks of gestation and 2 had therapeutic abortion at 16 and 19 weeks of gestation. The remaining 11 (52.4%) were not given chemotherapy while pregnant as 3 patients (27.3%) presented late in their pregnancy after 34 weeks of gestation ending in normal live births and then received induction chemotherapy and 8 patients (72.7%) presented early in their pregnancy and they either spontaneously aborted or had a therapeutic termination of their pregnancy before starting chemotherapy. Among the CML patients (n=11), 9 patients received Hydroxyurea (HU) treatment during pregnancy, one patient received α-Interferon and one patient was treated with leukapheresis. Eight of the 11 patients (63.6%) had normal live births. Three patients (18.1%) aborted, 2 at 11 weeks of gestation while on HU treatment and one shortly after diagnosis before treatment. Of the total 32 patients 13 (40.6%) subsequently underwent allogeneic stem cell transplant, 8 for AML, 2 for ALL and 3 for CML. At a median follow up of 19.1 months, the disease free survival (DFS) and overall survival (OS) were 19% and 33.3% respectively for the acute leukemia patients. For CML patients, the OS was 90.9% at a median follow up of 38 months.
The above data suggest that a high CR rate and satisfactory OS can be achieved in leukemia during pregnancy. Furthermore, chemotherapy did not lead to any teratogenic effects among live births. All spontaneous and therapeutic abortions were for disease related complications and not chemotherapy induced.
This series of cases, which is the largest from a single institution, clearly supports early treatment of leukemia during pregnancy based on the underlying disease rather than concomitant pregnancy.
Activation of Monocytes by Aspergillus Fumigatus Hyphae and Conidia.
Authors: Haddad Ziad , Loeffler Juergen , Bonin Michael , Schumacher Ulrike , Markulin Marija , Frank Friederike , Kapp Markus , Einsele Hermann , Hebart Holger 
Published: October 2019

Abstract
Invasive aspergillosis is a life-threatening infection in immunocompromised patients. Activation of innate immune cells is crucial for the successful control of invasive aspergillosis. Monocytes play an important role in the cellular defense against Aspergillus fumigatus by attacking defined differentiation states of the fungus and by the release of pro-inflammatory cytokines and chemokines. In order to get a better understanding on pathways involved in these defense mechanism, genome-wide expression profiling was performed after incubation of CD14+ selected monocytes with A. fumigatus conidia and hyphae for 3, 6 and 9 hours using the Affymetrix HG-U133A array. Moreover, phagocytosis of conidia was analyzed by immunofluorescence. Expression of defined cytokines and chemokines was confirmed by Real-time PCR and on protein level by ELISA. Phagocytosis of conidia was observed during the first 3 hours (up to 2–3 conidia/monocyte). The conidia became swollen after 6 hours. By genome-wide expression profiling, ~600 genes were differentially regulated after 3 hours of incubation with hyphae and ~200 after incubation with conidia. At 6 and 9 hours of incubation, the number of differentially regulated genes showed no difference (~400 genes by both stimuli). Hyphae but not conidia strongly induced the expression of chemokines attracting neutrophils and T-lymphocytes as well as their receptors already after 3 hours, indicating that phagocytosis of conidia does not immediately induce expression of inflammatory genes. Pentraxin-3 was upregulated after 3 but not after 6 hours by both conidia and hyphae. PTX-3 binds to A. fumigatus and plays a role in initiating phagocytosis. Genes encoding for inflammatory cytokines and chemokines as well as their receptors were found to be up-regulated at 6 and 9 hours by both stimuli. Urokinase plasminogen activator (uPA), which plays an essential role in regulating fibrinolysis and thereby monocyte/macrophage recruitment to sites of inflammation, was also found to be upregulated after stimulation with both stimuli. ELISA experiments confirmed these results on protein level, demonstrating a steady increase of chemokine and cytokine concentrations in culture supernatants from 3 to 9 hours.
In conclusion, A. fumigatus differentially regulates a wide number of genes expressed by human monocytes, which play a crucial role in immune response during infection. The expression of these genes is dependent on the differentiation and germination state of the fungus and the incubation period.
Iron Acquisition in Reticulocytes: Evidence for a Kiss and Run Mechanism.
Authors: Sheftel Alex D. , Zhang An-sheng , Shirihai Orian , Ponka Premysl 
Published: October 2019

Abstract
During differentiation, immature erythroid cells acquire vast amounts of iron at a breakneck rate. Proper coordination of iron delivery and utilization in heme synthesis is essential and disruption of this process likely underlies iron loading disorders such as sideroblastic anemia and myelodysplastic syndrome with ringed sideroblasts. Iron is taken up by the cells via receptor mediated endocytosis, a process whereby diferric transferrin (Tf) binds to its cognate receptor (TfR) on the erythroid cell plasma membrane, followed by internalization of the Tf-TfR complex. Subsequent to endocytosis, the endosome is acidified by a H+-ATPase, allowing the release of iron from Tf. Through an unknown mechanism, iron is targeted to the inner membrane of the mitochondria, where the enzyme that inserts Fe into protoporphyrin IX, ferrochelatase, resides. Although it has been demonstrated that the divalent metal transporter, DMT1, is responsible for the egress of reduced Fe from the vesicle, the immediate fate of the iron atoms after their transport across the vesicular membrane remains unknown. Because reduced iron is a strong pro-oxidant, contributing to free radical formation through Fenton chemistry, it has been predicted that an iron binding molecule shuttles Fe from the endosome to mitochondria. However, this much sought iron binding intermediate, that would constitute the labile iron pool (LIP), has yet to be identified. Thus, we hypothesize that, in Hb-producing cells, there is a direct relaying of Fe from the endosomal machinery to that of the mitochondria. By loading the cytoplasm of reticulocytes with an impermeant form of the iron chelator, desferrioxamine, (hDFO) which would intercept Fe that traversed the cytosol bound to the putative LIP intermediate, we show that 59Fe, delivered via Tf, can bypass the cytosol. Importantly, iron delivered to these cells in a form that freely diffuses across the membrane, iron-salicylaldehyde isonicotinoyl hydrazone (59FeSIH2), was significantly prevented from being used for heme synthesis in hDFO-laden reticulocytes. We have also used time-lapse confocal microscopy to track iron-loaded endosomes and mitochondria with high spatial and temporal resolutions. Using this approach, we have found that endosomes are very mobile organelles that continuously traverse the cytosol and touch a number of mitochondria multiple times. Addition of N-(6-aminohexyl)-5-chloro-1-naphthalene-sulfonamide (W-7), a calmodulin antagonist that is known to block the myosin motor, to cells that had been treated with fluorescent holo-Tf, inhibited endosomal movement. Interestingly, W-7 treatment of cells whose endosomes were loaded with 59Fe-Tf blocked both incorporation of that iron into heme or mobilization of the iron by chelators. Together, these data are congruent with our hypothesis that iron is directly delivered to mitochondria by endosomes in a “kiss and run” paradigm.
Consequences of DMT1 Mutation on Proliferation and Hemoglobinization of Erythroid Progenitors In Vitro.
Authors: Priwitzerova Monika , Pospisilova Dagmar , Indrak Karel , Ponka Prem , Divoky Vladimir 
Published: October 2019

Abstract
Disorders of iron metabolism and homeostatis belong to the most common diseases in humans; however, neither the regulation of iron metabolism in erythroid cells nor the pathophysiology of these diseases are completely understood. Last year we reported at this meeting a case of severe hypochromic microcytic anemia caused by a homozygous mutation in the divalent metal transporter 1 (DMT1) gene (DMT1 1285G>C). The defective growth of this patient’s erythroid progenitors in vitro was rescued by the addition of 10 μM iron-salicylaldehyde isonicotinoyl hydrazone (Fe-SIH), an iron chelate that has been shown to deliver iron for heme synthesis without involving the transferrin receptor/DMT1 pathway. To further characterize the impact of the DMT1 mutation on the in vitro growth of erythroid progenitors, 10 μM Fe-SIH, 25 μM hemin or 10 μM zinc chloride (ZnCl2) were added to the erythropoietin (Epo) containing cultures. All substances increased the plating efficiency in normal control as well as mutant BFU-Es. Moreover, all substances led to a 1.4 to 1.6 fold increase in hemoglobin (Hb) content in normal BFU-Es. Although hemin did not significantly increase Hb content in the patient’s BFU-E, the addition of Fe-SIH to the Epo/hemin-containing cultures increased Hb content 2.2 fold. Since Hb synthesis in heme-deficient erythroid cells is inhibited by heme-regulated inhibitor (HRI) kinase, which specifically phosphorylates the α subunit of the eukaryotic initiation factor 2 (eIF2α), we have analyzed the level of eIF2α phosphorylation in cytospine-harvested BFU-Es. Immunofluorescence analysis of erythroid cells with phospo-eIF2α (Ser51) antibody revealed increased phosphorylation of eIF2α in mutant BFU-Es compared to control BFU-Es grown under all aforementioned conditions. The most striking differences were observed in Epo and Epo/hemin containing cultures, in which the fractions of phospho-eIF2α-positive cells were significantly higher in mutant BFU-Es. These data suggest that the block of terminal differentiation/hemoglobinization in the DMT1-mutant erythroid cells is only partially caused by translational arrest of globin chain synthesis; the delivery of iron may be required for other cellular functions apart from Hb synthesis. Interestingly, the most prominent positive effect on the proliferation (i.e., BFU-E cellularity) as well as hemoglobinization of mutant BFU-Es had a combination of Epo/Fe-SIH and ZnCl2; this combination led to the highest increase in Hb content that was associated with almost complete lack of eIF2α phosphorylation. This suggests that the addition of Zn2+ to Fe-SIH containing cultures further stimulates processes that are initially rescued in DMT1-mutant erythroid cells by the addition of iron. We conclude, that the DMT1 defect in erythroid cells is complex, probably involving the combination of transcriptional and translational defects that cannot be rescued by hemin alone.
Figure Figure
Aberrant Ferroportin 1 Regulation and Iron Homeostasis Interferes with Development of the Spleen Stroma during Murine Embryogenesis.
Authors: Mok Henry , Mendoza Miriam , Prchal Josef T. , Balogh Peter , Schumacher Armin 
Published: October 2019

Abstract
We have previously identified a regulatory mutation in the ferroportin 1 (Fpn1) locus in polycythaemia (Pcm) mutant mice, leading to transient iron overload and polycythemia during postnatal development. A 58-base pair deletion within the Fpn1 promoter region caused aberrant transcription initiation and resulted in the absence of the iron-responsive element in the 5′ untranslated region of the vast majority of Fpn1 transcripts, thereby disrupting translational regulation of Fpn1 expression. Interestingly, at birth Pcm mutant pups were remarkable for severe iron deficiency and a hypochromic, microcytic anemia. Here, we demonstrate that decreased placental syncytiotrophoblast expression of Fpn1 protein governs decreased embryonic iron levels during late gestation, implicating Fpn1 in maternal-to-fetal iron transport in the placenta. The decreased placental expression of Fpn1 protein appeared to be regulated at the transcriptional level. In striking contrast, increased Fpn1 protein was observed in the embryonic spleen during late gestation, mediated by a post-transcriptional mechanism. This correlated with a significant increase in apoptotic cell death of spleen stromal cells, culminating in a progressive regression of the spleen during late embryogenesis, more severe in Pcm homozygotes. Importantly, Pcm describes a phase in spleen development subsequent to that affected in mutant alleles of the transcription factors Wt1, Hox11, Bapx1, and capsulin. During postnatal development, whereas Pcm heterozygotes retain a significant amount of spleen tissue, Pcm homozygotes display only a spleen rudiment, and are likely to be functionally asplenic throughout postnatal life. Phenylhydrazine treatment of Pcm heterozygotes during early postnatal development demonstrated a reduced functional capacity for erythroid hyperplasia in the spleen. Despite the significantly reduced organ size, splenic white pulp follicles appear to form normally in both Pcm heterozygotes and homozygotes. However, severe abnormalities of the red pulp sinusoidal endothelial are observed in mutant spleens using markers specific for endothelial cell subpopulations. Therefore, the Pcm mutation represents a novel murine model for disrupted splenogenesis that is due to aberrant tissue-specific regulation of the iron transporter Fpn1 during embryonic development.
Hepcidin Contributes to Anemia of Malignancy by Causing Sequestration of Iron in Hepatic Stores.
Authors: Rivera Seth , Liu Lide , Nemeth Elizabeta , Gabayan Victoria , Ganz Tomas 
Published: October 2019

Abstract
The iron regulatory hormone hepcidin is presumed to be the central mediator of anemia of inflammation (AI, anemia of chronic disease). Hepcidin is an acute phase protein which restricts iron absorption and release of iron from stores. Patients with hepatic adenomas producing large amounts of hepcidin had severe AI that resolved when the tumors were resected (Weinstein et al, 2002). In order to study the effects of hepcidin in anemia of malignancy, we created tumor xenografts in SCID mice, some of which were engineered to secrete large amounts of hepcidin (33 mice with control tumors, 30 with hepcidin producing tumors). Hepcidin producing tumors expressed 2000-times more hepcidin mRNA which also correlated with increased levels of hepcidin peptide detected in urine of these mice. Mice with hepcidin producing tumors were significantly more anemic (median hemoglobin = 10.4 vs. 8.4 g/dL, p=0.02) and had significantly lower serum iron values (median serum iron = 242 vs. 96 mg/dL, p<0.001). Liver iron was significantly higher in mice with hepcidin producing tumors (mean liver iron 199 vs. 142 mg/100 mg dry weight, p<0.001) even in the face of anemia and hypoferremia. Splenic and bone marrow iron levels were unchanged. Hepcidin contributes to the anemia of malignancy by sequestering iron predominately in hepatic stores, similar to the pattern seen in AI.
Lack of Anemia Despite Marked Elevation of Serum Methylmalonic Acid and Total Homocysteine in a Multiethnic Cohort.
Authors: Stabler Sally P. , Anand Kishlay , Huang Sam , Boden-Albala Bernadette , Allen Robert H. , Sacco Ralph L. 
Published: October 2019

Abstract
It is controversial whether asymptomatic patients with metabolic evidence of cobalamin (Cbl) deficiency need vitamin treatment. Patients with clinical abnormalities due to Cbl deficiency which are proven to correct with treatment invariably have elevated serum methylmalonic acid(MMA) and total homocysteine(tHcy). However, many subjects with elevated MMA are found in screening studies of seniors and they often have no classical clinical abnormalities. We correlated hematologic and neurologic findings with elevated MMA and tHcy in subjects enrolled in the Northern Manhattan Study. Eligible subjects were over 40 yr, had not had a stroke and lived in Manhattan. Approximately 3000 subjects had serum MMA, tHcy and other relevant data available. The samples were collected from 1993 to 2001 thus spanning food folate fortification in the United States. We analyzed those in the top 1% MMA and/or tHcy since these subjects had values seen also in clinical Cbl deficiency. There were 30 subjects with MMA 975 to 179,900 nM (normal<271 nM), 15 female, age 56 to 90 yr, and 19% white, 15% black, 60% other including Hispanic. Only 7of 27 had mild anemia (lowest value, 33.6%) and 6 of 27 had elevated MCV>100fL. The male subject with the highest MCV (109.8 fL), had a hematocrit of 42.7 %, MMA 179,900 nM, tHcy 86.3 uM and Cbl 34 pg/mL with no neurologic findings. Neurologic abnormalities were present in 5 of 30. One subject had high grade spastic paraparesis, 3 had peripheral nervous system deficits, and one had central nervous system defects.Serum tHcy and MMA were not higher in those with neurologic abnormalities. The serum creatinine was < 1.3 mg/dL in the 27 with values thus the elevated MMA was not attributable to renal failure. The serum Cbl was < 200 pg/mL in only 6 of 22 and < 350 pg/mL in 16 of 22. The top 1% of tHcy value ranged from 24.9 to 102 uM (normal<14uM) and only 7 of 31 of these subjects had elevated tHcy without associated elevated MMA. Eight of those in the top 1 percentile for tHcy were also in the top 1 percentile for MMA. We conclude 1.Serum MMA is elevated > 975 nM in 1% of a randomly selected urban multiethnic cohort. 2. Hematologic abnormalities were absent or mild in this group with high MMA. 3. Neurologic abnormalities were found consistent with Cbl deficiency in 17 % of those with high MMA. 4. Both MMA and tHcy are usually elevated. 5. Even though the elevations of MMA and tHcy overlapped those found in clinical studies of Cbl deficiciency these randomly discovered subjects were generally asymptomatic, suggesting that the pathophysiology of megaloblastic anemia and combined systems disease still needs to be investigated.