Journal of hematotherapy & stem cell research最新文献

{"title":"Ex vivo immunotherapy for patients with benzene-induced aplastic anemia.","authors":"Jiayu Chen,&nbsp;Weiwei Liu,&nbsp;Xiaohuai Wang,&nbsp;Huaiyu Chen,&nbsp;Jinming Wu,&nbsp;Yi Yang,&nbsp;Lubo Wu,&nbsp;Demao Yang","doi":"10.1089/152581603322448213","DOIUrl":"https://doi.org/10.1089/152581603322448213","url":null,"abstract":"<p><p>Aplastic anemia is a bone marrow failure disorder characterized by pancytopenia and a hypocellular marrow. Benzene is one of the etiologic agents capable of inducing the disease. With modest to severe aplastic anemia, one previously untreated patient and 13 patients who had failed immunosuppressive therapy were studied. Peripheral blood mononuclear cells from patients were expanded in vitro with a combination of cytokines and a calcium-mobilizing agents for 2 days, and the activated cells were infused intravenously once a week. In some cases, we used allogenic leukocytes instead of autologous cultured lymphocytes. After 6-35 weeks of the treatment, all patients had multilineage responses to this therapy and achieved complete disease remission, defined as normal blood count, independence from transfusion, and normal bone marrow histology. The therapy was safe and well tolerated with minimal side effects. The cultured cells produced interleukin-1 and induced immune responses in vivo. Serum interleukin-2 and interferon- gamma were detected following cell infusion. Finally, patients had sustained responses to the therapy and no relapse was found up to 18 months after cellular therapy.</p>","PeriodicalId":80030,"journal":{"name":"Journal of hematotherapy & stem cell research","volume":"12 5","pages":"505-14"},"PeriodicalIF":0.0,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/152581603322448213","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24055045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An efficient large-scale thawing procedure for cord blood cells destined for selection and ex vivo expansion of CD34+ cells.","authors":"Pascale Duchez,&nbsp;Bernard Dazey,&nbsp;Luc Douay,&nbsp;Gerard Vezon,&nbsp;Zoran Ivanovic","doi":"10.1089/152581603322448295","DOIUrl":"https://doi.org/10.1089/152581603322448295","url":null,"abstract":"THE MAIN DISADVANTAGES of transplantation of cord blood (CB) hematopoietic stem or progenitor cells (HSPC) are the delayed neutrophil and platelet reconstitution coupled with the difficulty in obtaining a large enough graft for patients weighing more than 30 kg (1). Both problems could be overcome by ex vivo expansion of CB progenitors. In most CB banks, the whole CB samples are stored in individual or double bags. The ex vivo expansion of progenitors in whole blood samples is inefficient; thus, a CD341 selection before an expansion procedure is a prerequisite. However, this selection using frozen-thawed blood samples is impaired by aggregate formation (“clumping”). To overcome this problem, addition of recombinant human deoxyribonuclease (DNase) has been proposed during thawing of CB cells prior to transplantation (2) or expansion (3). We have extended this procedure to clinical-grade conditions incorporating subsequent CD341 cell selection and expansion in two-step culture conditions. Two bags [(Macopharma, Lille, France) GSR 7000 A), each containing 125 ml of CB and 125 ml of cryoprotecting solution 20% dimethylsulfoxide (DMSO), from a single CB and frozen by using a controlled-rate procedure and stored in liquid nitrogen, were thawed in a water bath at 37°C. DNase (Pulmozyme Roche, Neuilly, France) (3750 units) and the MgCl2 solution (Cooper, Mellin, France) (0.5 M, 250 ml) were added to each bag. Two samples were pooled and then rehydrated slowly (10 min at 20–22°C) by adding 250 ml of Dextran 40-sorbitol solution (Braun Medical, Boulogne, France) and 3.3 ml of Gamma IV (0.5 g LFB). The cell suspension was filtered, incubated with anti-CD34, and transferred into the separation chamber (system Isolex 300i, Baxter, Deerfield, IL). An additional 7500 Units of DNase and 500 ml of MgCl2 were added before the addition of immunomagnetic microbeads (Baxter kit). The suspension was processed on Isolex 300i. The CD341 cells were transferred into 50-ml conical tubes and centrifuged for 10 min at 1500 rpm. The supernatant was removed, and the cells were resuspended in 10 ml of serum-free culture medium (Irvine Scientific, Santa Ana, CA). The CD341 cells were expanded in the same serum-free medium (200 ml; 10,000 cells/ml) in gas-permeable bags (Opticyte 390 cm2, Baxter, Maurepas, France) in the presence of stem cell factor (SCF; Amgen, Thousand Oaks, CA), megakaryocyte growth and development factor (MGDF) (Amgen), Flt3 ligand (RD Median 3.333 106 n 5 5) CD341 cells per sample (Fig. 1A), i.e., a mean recovery of 48.5% with respect to the values found in fresh CB samples (Fig. 1B). The purity of these","PeriodicalId":80030,"journal":{"name":"Journal of hematotherapy & stem cell research","volume":"12 5","pages":"587-9"},"PeriodicalIF":0.0,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/152581603322448295","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24055053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Colony-stimulating activity of fetal liver cells: synergistic role of stem cell factor in bone marrow recovery from aplastic anemia.","authors":"G M K Raju,&nbsp;S Guha,&nbsp;A Mukhopadhyay,&nbsp;L Kumar,&nbsp;V P Kale,&nbsp;S Mittal,&nbsp;D Deka,&nbsp;S Mohanty,&nbsp;V Kochupillai","doi":"10.1089/152581603322448196","DOIUrl":"https://doi.org/10.1089/152581603322448196","url":null,"abstract":"<p><p>Previously, we and others have shown that fetal liver infusion (FLI) leads to autologous hematopoietic improvement in 40-54% of patients with aplastic anemia. However, whether this recovery was spontaneous or the effect of the infused liver cells was not clear. To dissect the role of FLI in autologous hematopoietic recovery, the colony-supporting potential of fetal liver-conditioned medium (FLCM) was evaluated in bone marrow (BM) cells of normal adult and aplastic anemia patients. In both cases, each sample of FLCM supported the growth of colony-forming cells in semi solid culture medium. The FLCM was assayed for the presence of four principal colony-stimulating cytokines, namely stem cell factor (SCF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and erythropoietin (Epo). While GM-CSF, IL-3, and Epo were present in insignificant amounts or were altogether absent, 50-635 pg/ml of SCF was found in 8 of the 13 FLCM samples tested. Preliminary results of bioneutralization assay indicated the possible role of SCF, secreted by the FL cells, in colony-supporting activity of aplastic anemia and normal BM cells. Overall, our in vitro study implicates the paracrine role of infused FL cells in regenerating autologous hematopoiesis in aplastic anemia patients.</p>","PeriodicalId":80030,"journal":{"name":"Journal of hematotherapy & stem cell research","volume":"12 5","pages":"491-7"},"PeriodicalIF":0.0,"publicationDate":"2003-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/152581603322448196","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24055724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential responses of human neural and hematopoietic stem cells to ethanol exposure.","authors":"Hsiao-Nan Hao,&nbsp;Graham C Parker,&nbsp;Jane Zhao,&nbsp;Kaveh Barami,&nbsp;William D Lyman","doi":"10.1089/152581603322286024","DOIUrl":"https://doi.org/10.1089/152581603322286024","url":null,"abstract":"<p><p>The mechanisms underlying fetal developmental defects caused by maternal ethanol (EtOH) consumption remain unclear. The symptoms of fetal alcohol syndrome (FAS) include neurological and immunological dysfunctions that are linked to cell reduction in these systems. Neural (NSC) and hematopoietic stem cells (HSC) may be targets for the cytotoxic effects of EtOH. Furthermore, protein kinase C (PKC) signal transduction systems of these stem cells may be involved in EtOH-induced cell death. Purified CD34+ human fetal liver hematopoietic stem cells (HSC) and CD133+/nestin+ human neural stem cells (NSC) were exposed to 0.1-10 mM EtOH. A range of indices of cell damage indicated that these doses of EtOH were deleterious to NSC, but had no observable effects on HSC. Furthermore, the colony-forming ability of NSC was completely inhibited by 5 mM EtOH treatment, whereas HSC were unaffected by even 20 mM EtOH. These results suggest that NSC are much more sensitive to EtOH than HSC. Classic and novel PKC isozyme protein expressions in the membrane fraction of cells were differentially affected by EtOH exposure across the two stem cell types. Concentrations of EtOH capable of inducing NSC, but not HSC, death also changed apoptosis-associated PKC isozyme expression in the membrane of NSC, but not HSC. Therefore, PKC expression may mediate the susceptibility of NSC to EtOH-induced cytotoxicity via cell signal transduction pathways. The toxic effect of EtOH on NSC may lead to the decreased neural cell number observed in FAS patients. The comparable immunity of HSC to the deleterious effects of EtOH exposure indicates that the susceptibility of NSC is not simply due to their being stem cells and also may explain the relative lack of hematopoietic problems associated with FAS.</p>","PeriodicalId":80030,"journal":{"name":"Journal of hematotherapy & stem cell research","volume":"12 4","pages":"389-99"},"PeriodicalIF":0.0,"publicationDate":"2003-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/152581603322286024","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22568490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Significance of molecular quantification of minimal residual disease in metastatic neuroblastoma.","authors":"Andrei Tchirkov,&nbsp;Catherine Paillard,&nbsp;Pascale Halle,&nbsp;Frédéric Bernard,&nbsp;Pierre Bordigoni,&nbsp;Philippe Vago,&nbsp;François Deméocq,&nbsp;Justyna Kanold","doi":"10.1089/152581603322286060","DOIUrl":"https://doi.org/10.1089/152581603322286060","url":null,"abstract":"<p><p>Molecular detection of tumor cells is the most sensitive approach to study residual disease in bone marrow (BM), peripheral blood (PB), and peripheral blood stem cell (PBSC) autografts from children with metastatic neuroblastoma (NB). We have developed a real-time PCR assay that allows the quantification of tyrosine hydroxylase (TH) mRNA, a tissue-specific marker of neuroblasts. We investigated a total of 165 BM, PB, and PBSC samples from 30 children over 1 year of age with stage IV NB and correlated the findings with disease status and patient survival. The levels of TH mRNA agreed well with clinical status and were significantly different across the groups that included samples obtained from patients at diagnosis, after three cycles of chemotherapy, in complete or very good partial remission and at relapse. We found that overall survival was significantly worse for patients with >1000 TH copies in BM after initial chemotherapy (p=0.0075). In 57% of cases, autologous PBSC harvests were found to be contaminated by neuroblasts, the level of TH >500 copies being associated with a decreased survival (p=0.003). In addition, molecular quantification enabled an estimation of tumor depletion in contaminated autografts using CD34 selection (median, 3 logs). In conclusion, quantification of minimal residual disease in metastatic NB using real-time RT-PCR for TH mRNA appears to be of potential clinical value. Further studies are needed to ascertain prognostic implications of molecular analysis of residual disease.</p>","PeriodicalId":80030,"journal":{"name":"Journal of hematotherapy & stem cell research","volume":"12 4","pages":"435-42"},"PeriodicalIF":0.0,"publicationDate":"2003-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/152581603322286060","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22568928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expansion of mobilized peripheral blood progenitor cells under defined culture conditions rsing CD34+CD71-CD45- cells as a starting population.","authors":"Nicolas H Zech,&nbsp;Eberhard Gunsilius,&nbsp;Johannes Clausen,&nbsp;Elisabeth Hoflehner,&nbsp;Karoline Hoelzler,&nbsp;Günther Gastl,&nbsp;Andreas L Petzer","doi":"10.1089/152581603322286006","DOIUrl":"https://doi.org/10.1089/152581603322286006","url":null,"abstract":"<p><p>A major goal of experimental and clinical hematology is the identification of mechanisms and conditions supporting the expansion of transplantable hematopoietic stem cells. We assessed the expansion potential of CD34+CD71-CD45- cells derived from granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood under recently defined serum-free culture conditions. The CD34+CD71-CD45- cells in mobilized peripheral blood were found to contain the majority (92%+/-5.6) of primitive long-term culture initiating cells (LTCIC) and 53.5%+/-16.7 of the more committed colony-forming cells (CFC). Furthermore, this population represents 23.3%+/-4.1 of the total CD34+ cells and allows reduction of the cell density important for maintenance/expansion of primitive progenitor cells. CD34+ CD71- CD45- cells were cultured in defined serum-free media supplemented with 300 ng each of Flt-3 ligand and stem cell factor (SCF), 60 ng of interleukin (IL)-3, and 20 ng each of IL-6 and G-CSF. Mononuclear cells (MNC) and CFC were expanded 50-fold and 200-fold, respectively; primitive progenitor cells (LTC-IC) were maintained at input values after a total of 10 days of expansion. The addition of IL-15 to our cytokine cocktail expanded LTC-IC 2- to 3-fold and CFC to >500-fold. The data presented should allow clinical manipulation (purging) and expansion procedures with mobilized PBPC harvests without the loss of primitive progenitor cells and could be made applicable for large-scale clinical expansion.</p>","PeriodicalId":80030,"journal":{"name":"Journal of hematotherapy & stem cell research","volume":"12 4","pages":"367-73"},"PeriodicalIF":0.0,"publicationDate":"2003-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/152581603322286006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22568488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distinct requirements for Stat4 and Stat6 in hematopoietic progenitor cell responses to growth factors and chemokines.","authors":"Mark H Kaplan,&nbsp;Hua-Chen Chang,&nbsp;Scott Cooper,&nbsp;Younghee Lee,&nbsp;Hal E Broxmeyer","doi":"10.1089/152581603322286033","DOIUrl":"https://doi.org/10.1089/152581603322286033","url":null,"abstract":"<p><p>Hematopoietic progenitor cell (HPC) homeostasis is critical in maintaining innate immunity and healing processes. Recently, we demonstrated that Th1 cells regulate HPC homeostasis, partly based on altered homeostasis in Stat4- and Stat6-deficient mice. To explore changes in HPC responsiveness in altered T helper cell environments, we directly examined growth factor-stimulated colony formation and chemokine-induced myelosuppression of HPC in Stat4- and Stat6-deficient bone marrow cells. Stat6-deficient cells have increased responses to the synergy between granulocyte-macrophage colony-stimulating factor (GM-CSF) and steel factor (SLF), compared to wild-type and Stat4-deficient cells. Increased responses are eliminated by in vivo depletion of CD4 cells. Whereas Stat6-deficient bone marrow cells respond to chemokine-mediated myelosuppression, Stat4-deficient bone marrow cells are refractory to the suppressive effects of chemokines. Thus, T helper cell development affects HPC homeostasis through several mechanisms, including the sensitivity to growth factor stimulation and chemokine suppression of HPC colony formation. Since Stat4 and Stat6 regulate opposing programs of T helper differentiation, there are distinct requirements for Stat4 and Stat6 in regulation of growth factor and chemokine responses of HPC.</p>","PeriodicalId":80030,"journal":{"name":"Journal of hematotherapy & stem cell research","volume":"12 4","pages":"401-8"},"PeriodicalIF":0.0,"publicationDate":"2003-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/152581603322286033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22568925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CXCR-4 expression on bone marrow CD34+ cells prior to mobilization can predict mobilization adequacy in patients with hematologic malignancies.","authors":"Melissa Dabusti,&nbsp;Francesco Lanza,&nbsp;Diana Campioni,&nbsp;Barbara Castagnari,&nbsp;Alessia Tieghi,&nbsp;Sabrina Moretti,&nbsp;Marina Punturieri,&nbsp;Cristiano De Angeli,&nbsp;Romedio Spanedda,&nbsp;Eros Ferrazzi,&nbsp;Gianluigi Castoldi","doi":"10.1089/152581603322286051","DOIUrl":"https://doi.org/10.1089/152581603322286051","url":null,"abstract":"<p><p>To investigate the mechanisms of mobilization and of the factors implicated in the homing of progenitors and possibly understand the reasons for unpredicted mobilization failure, we analyzed CXCR-4 (CD184) expression on bone marrow (BM) CD34+ cells prior to peripheral blood stem cell (PBSC) mobilization in 24 patients affected by hematologic malignancies (non-Hodgkin lymphoma, multiple myeloma, and acute myeloid leukemia). We wanted to determine whether the level of CXCR-4 expressed by hematopoietic stem cells could influence mobilization process and therefore could be considered a predictive factor for mobilization adequacy. These data were also compared with stromal cell function as assessed by colony forming unit-fibroblast (CFU-F) and CFU endothelial cells (CFU-En) assays and stromal layer confluence capacity exhibited by patients' BM cells. In this study, we also compared CXCR-4 expression on CD34+ cells from different sources and at different migration stages specifically bone marrow (BM), steady state peripheral blood (SSPB), fetal cord blood (FCB), cord blood (CB), and mobilized PBSC. Seven (29%) of the 24 patients undergoing mobilization failed to achieve an adequate number of CD34+ stem cells (5 x 10(6)/kg CD34+ cells) and showed a very high expression frequency of CXCR-4 on BM CD34(+) stem cells (mean number of positive cells, 97%) investigated before the mobilization regimen. We also found that high expression intensity per cell for CXCR-4 was associated with lower amounts of mobilized CD34+ cells whereas those patients (17 out of 24 patients, 71%) with lower expression intensity per cell of CD184 on BM CD34+ cells prior to mobilization harvested at least 5 x 10(6)/kg CD34+ cells. Setting a cut off of 5 x 10(6)/kg CD34+ cells harvested, patients mobilizing less had a mean value of 97% CD34+ cells expressing CXCR-4 with a relative mean channel fluorescence of 458 whereas patients mobilizing more than 5 x 10(6)/kg CD34+ progenitors showed a mean value of 59.8% CD34+/CXCR4+ cells with a relative mean channel fluorescence value of 305. Interestingly, in the poor mobilizers group, the marrow stromal microenvironment was found to be more severely damaged in comparison with that of good mobilizers. The comparative analysis of CXCR-4 expression showed no difference in percentage values between steady-state PB (87.4%) and BM (85.1%) stem cells whereas mobilized CD34+ stem cells have a lower expression frequency of CXCR-4 (71.6%) compared to that of progenitors from other sources. Fetal blood CD34+ stem cells had the lowest mean expression frequency of CD184 antigen (36.3%), while CB cells had the highest (94.8%). In conclusion, this study provides evidence that monitoring CXCR-4 CD34 double positive cells before mobilization can be regarded as a predictive factor for mobilization outcome, giving us directional cues for the choice of the best stem cell mobilization regimens.</p>","PeriodicalId":80030,"journal":{"name":"Journal of hematotherapy & stem cell research","volume":"12 4","pages":"425-34"},"PeriodicalIF":0.0,"publicationDate":"2003-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/152581603322286051","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22568927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Robust levels of long-term multilineage reconstitution in the absence of stem cell self-replication in W/Wv mice transplanted with purified stem cells.","authors":"Anna Rita Migliaccio,&nbsp;Rodolfo Lorenzini,&nbsp;Alessandro M Vannucchi,&nbsp;Gerald J Spangrude,&nbsp;Giovanni Migliaccio","doi":"10.1089/152581603322286042","DOIUrl":"https://doi.org/10.1089/152581603322286042","url":null,"abstract":"<p><p>Isolation of primitive blood stem cells by different methods results in cell populations with distinct biological activities. This study was aimed at resolving differences in the frequency of multilineage reconstituting cells (MRC) and their precursors (pMRC) in cell populations isolated by positive selection for Sca-1 compared to those isolated by negative selection for 15-1.1. Separation of wheat germ agglutinin-positive mouse bone marrow cells into 15-1.1neg or Sca-1+ subsets was performed by flow cytometry. The isolated cells were transplanted into W/Wv or normal irradiated recipient mice and reconstitution was evaluated over time. Sca-1+ cells were less frequent and contained more MRC than 15-1.1neg cells, while pMRC were found mainly among 15-1.1neg cells. MRC activity was exclusively contained within the Sca-1+ subpopulation of 15-1.1neg cells, but marrow from 7 robustly engrafted W/Wv mice did not contain donor-derived MRC, indicating that 15-1.1negSca-1+ cells contain low numbers of pMRC. Functional differences between 15-1.1neg and Sca-1+ cells were further confirmed by reverse transcriptase (RT)-PCR gene expression analysis. Early hematopoiesis-specific transcription factors (Scl, Gata-2, and Gata-1) were amplified from cDNA prepared from Sca-1+ but not 15-1.1neg cells. This study indicates that cell populations isolated as Sca-1+ are functionally distinct from those isolated as 15-1.1neg in that few pMRC are included among Sca-1+ cells and that MRC and pMRC are two distinct and separable cell populations.</p>","PeriodicalId":80030,"journal":{"name":"Journal of hematotherapy & stem cell research","volume":"12 4","pages":"409-24"},"PeriodicalIF":0.0,"publicationDate":"2003-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/152581603322286042","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22568926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydroxyurea-induced skin ulcerations in patients with chronic myeloproliferative disorders.","authors":"Ana María Bravo Blanco,&nbsp;Jose Luis Sastre Moral,&nbsp;Sonia Tembrás,&nbsp;Rocío Gómez,&nbsp;Carlos Ulibarrena,&nbsp;María Obdulia Vazquez","doi":"10.1089/152581603322286097","DOIUrl":"https://doi.org/10.1089/152581603322286097","url":null,"abstract":"461 HYDROXYUREA (HU) is a hydroxylated derivative of urea used in the treatment of myeloproliferative disorders and acute myelogenous leukemia. It inhibits cellular DNA synthesis and promotes cell death in the S phase of the cell cycle through its action on the enzyme ribonucleotide reductase, an essential enzyme to DNA synthesis (1). HU is well tolerated with a relatively low toxicity profile. Side effects may be systemic or restricted to skin and mucous membranes. Dermatological adverse effects are underestimated because they are usually benign. These include alopecia, xerosis, diffuse hyperpigmentation, brown-nail discoloration, fixed drug eruption, stomatitis, acral erythema and scaling eruptions, photosensitization, skin tumors on UV-light-exposed areas, dermatomyositis-like dermatitis, lichen planus-like dermatitis, and painful leg ulcerations (2). We report 6 patients in whom cutaneous leg ulcers developed while receiving HU. Their characteristics are summarized in Table 1. The reported incidence of adverse reactions varies from 10 to 35% and leg ulcers have been described in less than 0.1% of patients (3). Since the first description by Montefusco et al. in 1986, HU-related leg ulcers have been reported following chronic therapeutic doses. The first lesions usually observed after 0.7–7 years (4). There was no relationship between sex ratio, age, duration of treatment, and daily dose, neither with the appearance, worsening, and regressions of the lesions and nor with the complementary therapy received for the control of the haematological disease (5). The most common site of ulcers is on legs, mainly located near the malleoli, but they were occasionally found over the tibia, on feet, and on calves (1). The clinical feature of our cases is the early appearance of lesions in older patients. All of them developed extensive and progressive skin changes with ulceration on malleoli, calves, or hands (see Fig. 1). Ulcers were extremely painful and fibrous with violaceous macules, edema surrounding them, and thin periulcerous skin. Histology of vascular changes showed leukocytoclastic vasculitis, perivascular lymphocytic inflammation, formation of thrombus, swelling of the endothelial cells, and thickening of the vascular walls (6). The pathogenesis remains poorly understood and probably leg ulcers are often multifactorial. Microvascular circulatory disturbance in myeloproliferative disorders includes erytromelalgia, Raynaud’s phenomenon, digital ischemia, acrocyanosis, blue toe syndrome, livedo reticularis, cutaneous ulcers, or necrotic purpura (7). Besides, HU causes cumulative toxicity on the basal layer of epidermis producing cutaneous atrophy and impaired wound healing (8). Furthermore, the megaloblastic erythrocyte changes, which occur in almost all patients taking HU, may be a pathogenic factor. Macroerytrocytosis can be considered as an acquired blood dyscrasia and similar leg ulcers have long been known to occur with certain hereditary bl","PeriodicalId":80030,"journal":{"name":"Journal of hematotherapy & stem cell research","volume":"12 4","pages":"461-3"},"PeriodicalIF":0.0,"publicationDate":"2003-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/152581603322286097","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22568931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}