bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drug Selection Enrichment of Type II Pneumocytes Following Transplant of P140K MGMT Lentiviral Transduced Hematopoietic Stem Cells.
Authors: Reese Jane S. , Roth Justin C. , Gerson Stanton L. 
Published: October 2019

Abstract
Recent reports have shown that bone marrow derived cells can differentiate into epithelial cells of the lung. Data indicate that this event occurs in the absence of cell fusion, however the numbers of donor-derived cells are present at a low frequency. In this study, we investigated whether hematopoietic donor-derived Type II pneumocytes could be enriched by lentiviral or retroviral expression of P140K MGMT. MGMT encodes O6 alkylguanine DNA alkyltransferase (AGT), a major drug resistance protein for DNA damage induced by BCNU. This gene transfer approach provides a selective advantage to wild type donor cells by transduction with a mutant human AGT (P140K MFG-MGMT) which confers resistance to BG and BCNU. P140K transduced whole bone marrow or Sca+kit+lin- cells were transplanted into lethally irradiated wild type recipients followed by two or three doses of 30 mg/kg BG and 7.5–10 mg/kg BCNU. After drug selection, human AGT expressing murine cells comprised up to 99% of bone marrow in mice harvested 5–7 months after transplant (n=8). These mice also showed enrichment for the total number of donor derived alveolar cells after drug treatment from 25% (n= 2 untreated mice) to 46% ± 9.7 (n=4 mice; p=.0001). The high percentage of donor cells was attributed to the hematopoietic cells present in the lung, however there were also donor-derived cells with epithelial morphology. Similar bone marrow plasticity studies have elicited controversy, largely due to the technical limitations of in situ detection of organ specific donor cells. To overcome the inability to accurately detect single cells in lung tissue, we used dispase mediated cell dissociation followed by analysis of single cell suspensions by fluorescent microscopy. Type II pneumocytes were detected using a Pro-surfactant protein C antibody that is specific for alveolar Type II cells. Donor P140K transduced cells were co-detected using an antibody to AGT. Using this method, 10–12% of total cells isolated from the lung were Type II pneumocytes and 1.5–8% of these cells co-expressed AGT in mice treated with BG and BCNU (n=3). This indicated drug selection mediated expansion of transplanted marrow-derived cells with characteristics of lung epithelial Type II pneumocytes. These numbers represent an increase compared to untreated mice in which we were unable to detect donor-derived Type II cells (n=2) and published results indicating 0.2–0.6% of total lung cells are bone marrow-derived epithelial cells. This study indicates that MGMT mediated drug selection of hematopoietic cells, using lentiviral MGMT gene transfer, enhances their capacity for organ specific selection and repopulation of lung alveolar epithelial cells. Drug selection gene transfer may augment transdifferentiation and have therapeutic implications for pulmonary disorders.
Both the Activity and Stability of the Transcriptional Repressor PLZF Are Modified by the Class III Histone Deacetylase SIRT1.
Authors: McConnell Melanie-Jane , Langley Emma , Martinez-Martinez Yolanda , Kouzarides Tony , Licht Jonathan D. 
Published: October 2019

Abstract
The transcription factor PLZF is expressed in hematopoietic development and rearranged in t(11;17) acute promyelocytic leukemia (APL). PLZF expression is high in the quiescent progenitor CD34+ cell, and declines during differentiation along myeloid and erythroid lineages. PLZF encodes a BTB-Zinc finger transcriptional repressor that inhibits the cell cycle through inhibition of targets genes such as cyclin A and c-myc through the recruitment of histone deacetylase complexes. However, PLZF itself is regulated by acetylation. In a separate study we demonstrate that acetylation of PLZF by p300/CBP enhances the transcriptional repression activity of PLZF. Through a yeast two-hybrid study we found that PLZF associates with the protein deacetylase SIRT1. SIRT1 is a member of the sirtuin family of class III histone deacetylases. In model organisms such as yeast, worms and flies, sirtuins play a common role in lifespan extension. The interaction between PLZF and SIRT1 was confirmed by co-precipitation of endogenous proteins and localized to the zinc fingers of PLZF, the region targeted for acetylation by p300/CBP. Acetylation of PLZF mediated by p300/CBP was reversed by SIRT1. Furthermore while acetylation of PLZF enhances its ability to repress transcription, co-expression of SIRT1 decreased PLZF transcriptional repression activity, consistent with loss of acetylation. Conversely, inhibition of SIRT1 activity with nicotinamide enhanced both PLZF acetylation and transcriptional repression of PLZF on its endogenous target gene c-myc. Further, increasing PLZF acetylation by inhibition of SIRT1 was associated with decreased PLZF stability. Acetyl-PLZF levels were stabilized by inhibition of the proteosomal degradation machinery, together implying that PLZF acetylation and activation results in increased protein turnover. These data point to the increasing complexity of the role of acetylation in transcriptional regulation and stand in contrast with data for the related Bcl6 repressor where acetylation of the protein inhibits repression. These data also indicate a novel function for sirtuins in regulation of transcriptional repression.
Transplantation of Human Aldehyde Dehydrogenase Expressing Cells Leads to Widespread Tissue Distribution of Donor Cells in the Novel NOD/SCID/MPSVII Xenotransplantation Model.
Authors: Hess David A. , Craft Timothy P. , Wirthlin Louisa , Herrbrich Phillip E. , Hofling A. Alex , Sands Mark S. , Nolta Jan A. 
Published: October 2019

Abstract
Beta-glucuronidase (GUSB) is a lysosomal enzyme expressed in virtually all human and murine cell types. Transplantation of GUSB-expressing human hematopoietic stem cells (HSC) into the recently developed GUSB-deficient NOD/SCID/MPSVII mouse allows for the sensitive histochemical detection of xenotransplanted cells in hematopoietic and non-hematopoietic tissues. Most notably, human cells expressing GUSB can be detected without reliance on the expression of human cell surface markers. In addition, we have recently characterized a novel population of reconstituting HSC from human umbilical cord blood (UCB) by lineage depletion (Lin−) followed by selection of cells with high aldehyde dehydrogenase (ALDH) activity. We have also demonstrated the robust hematopoietic engraftment of ALDHhiLin− cells in the NOD/SCID model. Because donor cell surface protein expression may be altered in non-hematopoietic tissues due to cell fusion or other mechanisms, we have used the NOD/SCID/MPSVII model to study the tissue distribution of ALDHhiLin− or ALDHloLin− cells in multiple organs. Tail vein injection of 2x105–4x105 ALDHhiLin− cells into sub-lethally irradiated (300cGy) NOD/SCID/MPSVII mice (n=3) demonstrated high levels of hematopoietic (human CD45+ cells) engraftment in the BM (70.5±15.1%), spleen (7.0±2.8%) and peripheral blood (17.0±10.7%). In contrast, injection of 2x105–106 ALDHloLin− cells (n=3) did produce significant human cell engraftment in these hematopoietic tissues, with only 1 of 3 mice engrafting at 0.3% CD45+ cells in the murine BM. By using GUSB-specific histochemical staining, significant human engraftment was detected, with single cell sensitivity, in hematopoietic (BM and spleen) and non-hematopoietic (liver, pancreas, and lung) tissues of mice transplanted with ALDHhiLin− cells. GUSB activity was colocalized with CD45 immunohistochemical staining in the BM, liver, and pancreas of mice transplanted with ALDHhiLin− cells. Human cells were not detected in the muscle or brain of these engrafted mice. In contrast, mice transplanted with equal doses of ALDHloLin− cells showed no GUSB expression in the BM, spleen, liver, pancreas, lung, muscle, and brain. We are currently developing a flow cytometric assay to enumerate the frequency of GUSB expressing cells in the tissues of the transplanted mice. These data indicate that ALDHhiLin− UCB cells demonstrate previously uncharacterized engraftment in the liver, pancreas, and lung of NOD/SCID MPSVII mice. This novel model provides a unique opportunity to visualize donor human cells after xenotransplantation without reliance upon the expression of cell surface proteins, in situ hybridization, or cell labeling using viral transduction or membrane dyes.
Pulmonary Hypertension: A Common Complication in Thalassemia.
Authors: Vichinsky Elliott P. , Morris Claudia R. , Hagar Ward , Gardner Jennifer , Singer Sylvia Titi , Foote Drucilla , Quirolo Keith C. 
Published: October 2019

Abstract
Pulmonary hypertension (PHT) is a complication that is associated with high mortality rate. It is increasingly recognized in thalassemia intermedia (TI) as a leading factor in heart failure and death. Undetected PHT has been reported in 60–75% of patients. Data on PHT and thalassemia major is limited. However, these patients have many risk factors for PHT, including splenectomy, red cell phosphatidylserine exposure, coagulation abnormalities and iron overload. Since chronic hemolysis continues despite transfusion, these patients are also at risk for hemolysis-associated PHT. This is a recently described syndrome where free hemoglobin scavenges nitrous oxide and catalyzes the formation of reactive oxygen species. The purpose of this study is to determine the prevalence of PHT in transfused thalassemia patients and its risk factors. We compared the echocardiogram of 28 patients with their transfusion history, iron stores, chest x-ray, age, hemoglobin level, splenectomy status and cardiac function.
The prevalence of PHT in this population was 57%. Sixteen of the 28 patients had a tricuspid regurgitant jet velocity ≥2.5 m/s, indicating PHT. 5 patients had a jet velocity ≥ 2.9 m/s suggestive of moderate PHT. Patients with PHT were more likely to be older (29±10 vs. 24±7 years without PHT, r=0.52, p=0.01) and male (56%). 41% of the female patients undergoing echocardiogram exam had PHT, while 82% of the men screened had PHT (p=0.03). PHT was also inversely related to ferritin level (r=−0.46, p=0.02). A history of an abnormal CXR occurred more frequently in the PHT group (38% vs. 8%, p=0.08), but did not reach statistical significance. However, there was no difference in hemoglobin level, creatinine, splenectomy rate (63% vs. 58%) or abnormal cardiac function between patients with PHT vs. those without PHT.
Two of the 16 patients with PHT have initiated therapy with hypertransfusion or sildenafil. An intermittently transfused 25-year-old female patient lowered the tricuspid jet velocity from 3.2 to 2.4 m/s following hypertransfusion program. The second patient, a 44-year-old chronically transfused female, lowered her tricuspid jet velocity from 3 to 2.3 m/s within one month of sildenafil therapy.
In conclusion, PHT is a common complication in transfused thalassemia patients that is under recognized and under treated. In contrast to other complications, adequate chelation and low iron stores are not protective. Since secondary PHT is associated with a high mortality and morbidity, annual screening with echocardiogram for all thalassemia patients is recommended. Early identification of PHT and its risk factors may prevent the irreversible cardiomyopathy that may develop. Prospective studies evaluating therapies, including hypertransfusion, sildenafil and arginine are needed.
Non-Invasive Monitoring of Hepatic Iron Concentration during Oral Chelation in Patients with Non-Regularly Transfused β-Thalassemia/Hb E Disease.
Authors: Pootrakul Pensri , Chua-anusorn Wanida , Fleming Adam , Clark Paul , Sirankapracha Pornpan , Kachintorn Udom , Chanyawattiwongse Somsak , Metarugcheep Pichest , St. Pierre Tim 
Published: October 2019

Abstract
Current non-invasive measurement techniques of hepatic iron concentration (HIC) include magnetic susceptometry (SQUID) and the magnetic resonance imaging (MRI) methods utilising T2 and T2*. HIC can be quantified through image measurement of the proton transverse relaxation rate (R2) (St. Pierre et al Blood 2004). The potential for using the St Pierre method to monitor changes in HIC of patients with β-thalassemia/Hb E undergoing iron chelation therapy was investigated.
Seventeen non-tansfusion dependant β-thal/Hb E patients who had not previously undergone chelation were studied. Subjects were chelated with the oral iron chelator Deferiprone (DFP) and had their HIC measured using both the R2-MRI and biopsy non-heme iron techniques pre and post treatment. Ferritin levels were also assayed for comparison. The subjects ages ranged from of 13 to 53 years (mean 31.6, SD 11.5). DFP was administered at a low dose of 50 mg/kg/Day with divided doses 2 –3 times daily. The periods of drug exposure ranged between 53 and 77 weeks (mean 64.1, SD 8.4).
HIC by R2-MRI and tissue iron chemical analysis, and serum ferritin
Measurement R2-HIC (mg/g DW) Biopsy-HIC (mg/g DW) Serum Ferritin (ng/ml) Mean ± SD Range Mean ± SD Range G.Mean ± SE Range Initial 17.8 ± 6.6 5.7 – 29.7 18.3 ± 9.0 6.0 – 40.1 2526 ± 432 842 – 6072 Final 8.4 ± 7.9 1.0 – 23.9 7.4 ± 7.3 0.2 – 25.5 416 ± 236 113 – 4030
The results show a significant decrease of HIC after long term administration of DFP with MRI and biopsy (p= .0004 and p<0.0001 respectively). Spearman rank correlations of R2-HIC with the liver non-heme Fe and serum ferritin measures gave positive values of 0.866 (p < 0.0001) and 0.768 (p < 0.0001) respectively. The mean reduction of R2-HIC, biopsy-HIC and serum ferritin were 53%, 69%, and 74%, respectively. A decrease of 20.5% (SD ±14.9%) in the standard deviation of the R2 distribution was observed suggesting a decrease in iron heterogeneity accompanied the mean HIC decrease. The results suggest that R2 MRI has the potential to be used as a clinical monitoring tool in chelation therapy.
A Novel Murine Model for Human Waldenstrom’s Macroglobulinemia.
Authors: Tassone Pierfrancesco , Neri Paola , Kutok Jeffery , Tournilhac Olivier , Santos Daniel Ditzel , Hatjiharissi Evdoxia , Venuta Salvatore , Anderson Kenneth C. , Treon Steven , Munshi Nikhil C. 
Published: October 2019

Abstract
The pre-clinical studies of investigational agents in Waldenstrom’s Macroglobulinemia (WM) have been limited by the lack of an in vivo animal model, which is representative of the disease in patients. We and others have previously demonstrated growth of primary myeloma cells in immunodeficient mice bearing a human bone marrow (huBM) implant (SCID-hu mice). We therefore evaluated the use of this model for propagation of WM tumor cells. Four weeks following implantation of human fetal bone chip in SCID mice, mononuclear cells obtained from BM aspirates of consenting WM patients were directly inoculated into the bone chip. Mice were then evaluated every 2 weeks for the presence of human immunoglobulins. Seven of 13 patient samples engrafted in mice 4 to 28 weeks after WM cell inoculation as confirmed by detection of circulating human IgM and/or human k or l chain of the same type as that from the patient from whom the BM aspirate was obtained. The levels of human paraproteins, which were detected in murine sera, showed a time-dependent increase. Importantly, immunohistochemical analysis of human bone chips retrieved from the mice showed diffuse infiltration of CD20+, IgM+ and/or k+ or l+ lymphoplasmacytic cells as well as mast cells, which, we recently demonstrated, provide growth and survival signals for WM cells (JCO 2004 22:571S). Consistent with our previous observations with the MM SCID-hu mouse model, hereto we did not observe infiltration of murine tissues by WM cells confirming the essential nature of the human BM microenvironment in supporting WM cell expansion. These studies therefore demonstrate the utility of the SCID-hu mouse model for the study of WM, and provide a pre-clinical model for the investigation of novel agents for the treatment of WM.
Intravenous Hemin as Prophylaxis of Allograft Function Following Second Liver Transplant for Erythropoietic Protoporphyria.
Authors: Schiller Gary J. , Goldstein Leonard , Finn Richard , Busuttil Ronald 
Published: October 2019

Abstract
Erythropoietic protoporphyria (EPP) is a rare disorder of heme biosynthesis caused by an inherited deficiency of mitochondrial ferrochelatase. This deficiency results in accumulation of protoporphyrin, a heme precursor, in bone marrow, skin, nervous system, and liver. In some patients, toxic levels of protoporphyrins in the liver cause chronic liver disease, cirrhosis, and hepatic failure. Liver transplantation is the only treatment available; however, the risk of allograft dysfunction is high as a result of continued, excessive protoporphyrin production due to the underlying systemic enzyme deficiency. We present the case of a 40 year-old man with EPP, diagnosed at age 6, who underwent orthotopic liver transplantation (OLT) at age 25. By age 31, biopsy-proven recurrent EPP with liver dysfunction was identified in the allograft with subsequent hepatic failure seven years later at age 38. A second liver transplant was complicated by a biliary anastomotic leak requiring further surgery and prolonged hospitalization. Six months prior to a second liver transplant, the patient was started on 4 mg/kg hemin infusions every week; following second liver transplant, the frequency was increased to twice weekly to maintain graft function. Infusions have been well tolerated and administered at home through a central venous catheter and there has been no evidence of iron overload. Three months following second transplant, blood alkaline phosphatase, ALT, AST, and bilirubin were 1009, 53, 64, and 11.5, respectively. Fourteen months after the second allograft, these levels are 234, 65, 65, and 1.2, respectively. Prior to hemin therapy, erythrocyte protoporphyrin level was 6600 mg/dl and was 5573 mg/dl immediately before second allograft. With twice weekly hemin, erythrocyte protoporphyrin level fourteen months after transplantation is 1240 mg/dl - greatly reduced but still elevated above the normal range. A liver biopsy three months after the second allograft showed cholestasis and biliary obstruction consistent with recurrent porphyria, but no subsequent biopsy has been performed yet despite improvement in alkaline phosphatase, bilirubin, and transaminase levels. This case study confirms an earlier report of clinical graft stabilization with hemin infusions after orthotopic liver transplantation for erythropoietic protoporphyria (Dellon et al., Transplantation2002; 73:911–5) and to our knowledge is the first case of long-term hemin use to maintain the integrity of a second liver allograft. Further follow-up and biopsy will be needed to determine the impact of this strategy on preserving graft function.
Parental Ferric Hydroxide Saccharate Therapy for Iron Deficiency Anemia: Safety and Efficacy.
Authors: Abdel-Razeq Hikmat , Radwi Ghazala , Khalil Manar , Bajouda Ali , Macalintal Marifi 
Published: October 2019

Abstract
Background: Iron deficiency remains the most common cause of anemia both locally and worldwide. In adults, the most common etiology of iron deficiency is blood loss; in men and postmenopausal women, iron deficiency almost inevitably signifies gastrointestinal (GI) blood loss. In women of childbearing age, genitourinary blood loss is the usual culprit. The goal of iron therapy for iron deficiency anemia (IDA) is to supply sufficient iron to repair the hemoglobin deficit and replenish storage iron. Iron can be given in either oral or parenteral forms. Because of the local and systemic side effects linked to parenteral iron therapy, it has been the less favored form of treatment of IDA. In this retrospective review, we report our experience using parenteral iron therapy for certain indications in patients with severe IDA.
Methods: Total number of patients was 57, 54 were females. Mean age was 31 years (12–60 yrs). Iron deficiency anemia was found to be due to: menorrhagia (46%), pregnancy (23%), malabsorption (22%), GI loss (7%) and poor dietary habits (4%). Patients presented with the following symptoms: dizziness (84%), exertional dyspnea (40%), palpitations (28%) and fatigue (23%). The indications for parenteral iron therapy were: severe symptomatic anemia (58%), pregnancy (25%), poor response to oral iron (14%), noncompliance to oral therapy (10%) and bleeding (7%).
Treatment plan: The form of iron used was Ferric Hydroxide Saccharate Complex. Iron requirement was calculated based on the following formula: Total iron deficiency in mg = [body weight (kg) x (normal Hb -actual Hb in g/L)x 0.24] + 500.The mean iron requirement was 1200mg (700mg – 2400mg). This was given in an outpatient setting as daily intravenous infusions starting with a dose of 100mg on the first day. The rest of the requirement was divided into doses of 200mg given over consecutive days.
Results: The mean Hb pre-treatment was 7.96g/dL (4.9–10.7g/dL) and the mean Hb post treatment was 10.6g/dL. (8.2–12.3g/dL). The rise in Hb was at a rate of 0.76/dL per week (0.17– 1.9). All patients tolerated the treatment well with only one complaining of burning sensation at the site of the IV line. There were no other side effects including anaphylactic reactions. In conclusion, the above data demonstrates that parenteral iron therapy, in the form and schedule given, is a fast, convenient, effective and safe means of treating severe, symptomatic IDA.