Journal of hematotherapy最新文献

{"title":"Factors influencing mobilization and engraftment in patients with metastatic breast cancer undergoing PBSC transplantation.","authors":"M de Magalhaes-Silverman,&nbsp;A D Donnenberg,&nbsp;J Lister,&nbsp;W Rybka,&nbsp;J Wilson,&nbsp;E Ball","doi":"10.1089/106161299320433","DOIUrl":"https://doi.org/10.1089/106161299320433","url":null,"abstract":"<p><p>Factors influencing mobilization and engraftment of PBSC were analyzed in 38 patients with metastatic breast cancer who were undergoing PBSC transplantation. None of these patients had had previous chemotherapy for metastatic disease. PBSC were mobilized with cyclophosphamide (CY) and G-CSF (n = 21) or CY and etoposide (CY-etoposide) and G-CSF (n = 17). All received cyclophosphamide 6000 mg/m2, thiotepa 500 mg/m2, and carboplatin 800 mg/m2 (CTCb) as preparative regimen. PBSC infusion was followed by G-CSF at 5 microg/kg in 30 patients or 10 microg/kg in 8 patients. A median number of 27 x 10(6) CD34+ cells/kg was obtained with a median of four aphereses. Previous chemotherapy, radiation therapy, marrow disease, time from previous chemotherapy to mobilization, and type of mobilization regimen did not have a statistically significant effect on collection efficiency (CE). CE was defined as the total number of CD34+ collected/number of collections. Engraftment was rapid, with patients reaching a neutrophil count of 0.5 x 10(9)/L a median of 9 days (range 7-23) and a platelet count of 20 x 10(9)/L a median of 12 days (range 8-28) after transplantation. Shorter times to platelet recovery were associated with a higher number of CD34+ cells infused (p = 0.012), CY mobilization (p = 0.033), and a lower number of prior chemotherapy cycles (p = 0.022). When the number of CD34+ cells was included in the proportional hazard model, no other variables were found to be significant predictors of platelet engraftment. Time to neutrophil recovery was negatively associated with the dose of G-CSF used after transplantation (p = 0.036) CD34 cell dose is an important predictor of engraftment kinetics. A posttransplant dose of G-CSF improves neutrophil recovery. For patients with metastatic breast cancer and no previous chemotherapy for metastatic disease, we have no evidence for a difference between CY and CY-Etoposide as the mobilization regimen.</p>","PeriodicalId":77208,"journal":{"name":"Journal of hematotherapy","volume":"8 2","pages":"167-72"},"PeriodicalIF":0.0,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/106161299320433","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21219132","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":"Isolation of highly purified autologous and allogeneic peripheral CD34+ cells using the CliniMACS device.","authors":"M Schumm,&nbsp;P Lang,&nbsp;G Taylor,&nbsp;S Kuçi,&nbsp;T Klingebiel,&nbsp;H J Bühring,&nbsp;A Geiselhart,&nbsp;D Niethammer,&nbsp;R Handgretinger","doi":"10.1089/106161299320488","DOIUrl":"https://doi.org/10.1089/106161299320488","url":null,"abstract":"<p><p>The CliniMACS CD34+ selection device was used for positive selection of apheresis products for autologous transplantation from 10 patients with malignant diseases and for allogeneic transplantation from 26 healthy donors. A total of 71 separations were performed. In 1 allogeneic donor, CD34+ progenitors were also isolated from bone marrow. Between 0.27 and 8.9 x 10(10) nucleated cells (median 4.9 x 10(10)) containing 0.09%-10.8% (median 0.67%) CD34+ progenitor cells were separated. After separation, a median number of 227 x 10(6) mononuclear cells (MNC) (51-524) were recovered, with a median viability of 99% (22%-100%) and a median purity of 97.0% (68.3%-99.7%) CD34+ cells. Depletion of T cells was extensive, with a median of 0.04% residual CD3+ cells (range <0.01%-0.92%). Residual CD19+ cells were between <0.01% and 17%, including CD34+CD19+ cells. Recovery of CD34+ cells was calculated according to the ISHAGE guidelines and ranged from 24% to 105% (median 71%). We conclude that with the CliniMACS device CD34+ cells with high purity and recovery can be isolated with concomitant effective T cell depletion in the allogeneic setting and with a high purging efficacy in the autologous setting.</p>","PeriodicalId":77208,"journal":{"name":"Journal of hematotherapy","volume":"8 2","pages":"209-18"},"PeriodicalIF":0.0,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/106161299320488","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21219817","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":"Peripheral blood stem cell mobilization for high-dose chemotherapy.","authors":"T Demirer,&nbsp;W I Bensinger,&nbsp;C D Buckner","doi":"10.1089/106161299320389","DOIUrl":"https://doi.org/10.1089/106161299320389","url":null,"abstract":"<p><p>Several studies have clearly documented a more rapid hematopoietic recovery with growth factor-mobilized PBSC than with bone marrow. Time to engraftment for neutrophils and platelets average 8-12 days in contrast to 2-4 weeks after bone marrow. This rapid hematopoietic recovery with PBSC has decreased the duration of hospitalization, transfusion requirements, and costs. Although growth factors alone may mobilize enough PBSC for high-dose chemotherapy, administration of growth factor after submyeloablative chemotherapy increases the yield of CD34+ cells. Based on the current data, CD34+ cell content of PBSC appears to be the single most powerful predictor of hematopoietic recovery. Infusion of > or =5 x 10(6) CD34+ cells/kg is associated with a rapid engraftment of neutrophils and platelets, although successful engraftment has also been reported with infusion of 2.5-5 x 10(6) CD34+ cells/kg. Age, prior radiotherapy, marrow involvement, and prior chemotherapy regimens are important factors influencing the yield of stem cells. Therefore, using these pa-rameters, we may identify the patients who will fail to mobilize sufficient numbers of PBSC before collection and use new strategies for stem cell mobilization. Because of the ease of collection and rapid engraftment after myeloablative therapy, PBSC have replaced bone marrow for autologous transplantation and may supplant bone marrow for allogeneic transplantation in the near future.</p>","PeriodicalId":77208,"journal":{"name":"Journal of hematotherapy","volume":"8 2","pages":"103-13"},"PeriodicalIF":0.0,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/106161299320389","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21219127","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":"Megakaryocyte ex vivo expansion potential of three hematopoietic sources in serum and serum-free medium.","authors":"P Lefebvre,&nbsp;J N Winter,&nbsp;L E Kahn,&nbsp;J G Giri,&nbsp;I Cohen","doi":"10.1089/106161299320479","DOIUrl":"https://doi.org/10.1089/106161299320479","url":null,"abstract":"<p><p>Megakaryocytes (MK) were expanded from purified human CD34+ cells obtained from three sources, bone marrow (BM), mobilized peripheral blood progenitor cells (PB), and umbilical cord (UC) blood. CD34+-selected cells were cultured for 12 days with 10 ng/ml thrombopoietin (TPO), 10 ng/ml IL-3, 10 ng/ml TPO + 10 ng/ml IL-3, or 200 ng/ml promegapoietin (PMP), a chimeric dual agonist of the c-Mpl and human IL-3 receptors. MK production was compared in serum-free versus human serum-supplemented liquid media. PMP and the combination of TPO and IL-3 (TPO + IL-3) increased MK production similarly. Culturing CD34+ cells with PMP in serum-free medium resulted in a twofold increase in MK yield compared with serum-supplemented medium. CD34+ cells from UC proliferated more than those from either BM or PB in liquid culture, resulting in much greater MK production under all conditions. Phenotypic analysis of the uncultured CD34+ cells showed that BM had a higher frequency of CD34+/CD41+ cells than PB or UC. TPO + IL-3 or PMP produced larger and greater numbers of BFU-MK and CFU-MK per seeded CD34+/CD41+ cell from UC than from either BM or PB. Thus, although uncultured CD34+-selected BM cells contained a higher frequency of committed mature MK progenitors, UC CD34+ cells had a greater proliferative capacity and, therefore, were more productive. PMP induced megakaryocytopoietic activity comparable to that achieved with TPO + IL-3 and may be useful for ex vivo expansion of MK for clinical trials.</p>","PeriodicalId":77208,"journal":{"name":"Journal of hematotherapy","volume":"8 2","pages":"199-208"},"PeriodicalIF":0.0,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/106161299320479","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21219816","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":"Hematotherapy Literature Watch.","authors":"","doi":"10.1089/106161299320505","DOIUrl":"https://doi.org/10.1089/106161299320505","url":null,"abstract":"","PeriodicalId":77208,"journal":{"name":"Journal of hematotherapy","volume":"8 2","pages":"223-8"},"PeriodicalIF":0.0,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/106161299320505","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21219818","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":"Large ex vivo expansion of human umbilical cord blood CD4+ and CD8+ T cells.","authors":"D Skea,&nbsp;N H Chang,&nbsp;R Hedge,&nbsp;B Dabek,&nbsp;T Wong,&nbsp;B Wettlaufer,&nbsp;D Bell","doi":"10.1089/106161299320406","DOIUrl":"https://doi.org/10.1089/106161299320406","url":null,"abstract":"<p><p>The use of human umbilical cord (UC) blood as a source of transplantable hematopoietic stem cells and progenitor cells may present some advantages over the use of BM. For example, it has been suggested that the degree of HLA matching may be less stringent, and the risk of GvHD may be lower. We have been studying the ex vivo expansion of UC blood T lymphocytes with a view to their use in the adoptive immunotherapy of cancer, autoimmunity, and infectious disease. We have developed a new method involving the use of a conditioned medium (XLCM) that consistently results in levels of UC blood T cell expansion not hitherto possible. Primary cultures of unfractionated low-density MNC (LDMNC) derived from UC blood treated with 5% XLCM routinely show expansions greater than 10,000-fold within 4 weeks. By contrast, similar FBS-free cultures treated with IL-2 expand less than 10-fold and not after 1 week, and cultures treated with IL-2 and concanavalin A (ConA) expand to a maximum of only 300-500-fold over 2 weeks and fail to continue to proliferate thereafter. The MAb, OKT3, which, when combined with IL-2 and FBS, is known to stimulate proliferation of adult peripheral blood lymphocytes, permitted only a 17-fold expansion of UC blood lymphocytes under the same conditions. Thus, XLCM, which can also stimulate adult peripheral blood lymphocyte expansion to levels exceeding 100,000-fold in 3-4 weeks, is uniquely able to stimulate proliferation of UC blood lymphocytes to high levels. From initiation of the UC blood or adult peripheral blood LDMNC/XLCM cultures up to approximately 2 weeks, the cultures are dominated by CD4+ T lymphocytes. By 4 weeks, >80% of the cultured cells bear the CD8+ phenotype, whereas UC blood T lymphocytes cultured in the presence of IL-2 are predominantly CD8+. Thus, XLCM not only allows high levels of expansion of UC blood T lymphocytes not heretofore possible but also permits the selective expansion of different T lymphocyte subsets from a single source.</p>","PeriodicalId":77208,"journal":{"name":"Journal of hematotherapy","volume":"8 2","pages":"129-39"},"PeriodicalIF":0.0,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/106161299320406","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21219129","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":"Use of reverse-transcriptase polymerase chain reaction (RT-PCR) for carcinoembryonic antigen, cytokeratin 19, and maspin in the detection of tumor cells in leukapheresis products from patients with breast cancer: comparison with immunocytochemistry.","authors":"J A López-Guerrero,&nbsp;P B Gilabert,&nbsp;E B González,&nbsp;M A Sanz Alonso,&nbsp;J P Pérez,&nbsp;A S Talens,&nbsp;E A Oraval,&nbsp;J de la Rubia Comos,&nbsp;S B Boix","doi":"10.1089/106161299320578","DOIUrl":"https://doi.org/10.1089/106161299320578","url":null,"abstract":"<p><p>This study evaluates the role of reverse-transcriptase polymerase chain reaction (RT-PCR) assay for carcinoembryonic antigen (CEA), cytokeratin 19 (CK19), and maspin transcripts to identify breast cancer cells (BCC) in leukapheresis products (LP) collected from breast cancer (BC) patients and compares these results with those obtained using immunocytochemistry (IC). Eighty-four LP obtained from 33 patients with stage II-III BC and control subjects without BC were screened for the presence of BCC by IC and CK19, CEA, and maspin expression using RT-PCR. CEA RT-PCR and IC were the only specific markers, as no false positives were detected in any patients without BC. CK19 RT-PCR gave 11% false positives, whereas maspin RT-PCR with 25% was the most unspecific marker. In LP from BC patients, positive results were observed in 70% and 63% for CK19 and CEA RT-PCR, respectively. For maspin RT-PCR, this percentage was 22%, and for IC it was 17%. There was a good correlation between the CEA and CK19 RT-PCR (p = 0.018). No correlation between CEA and CK19 RT-PCR and IC was found, and although 5 of the 6 IC+ samples were CEA+/CK19+, great discrepancies in the group of IC- samples were observed. Our data suggest that RT-PCR assays for CEA and, to a lesser extent, for CK19 have more sensitivity and specificity than IC to detect BCC in LP.</p>","PeriodicalId":77208,"journal":{"name":"Journal of hematotherapy","volume":"8 1","pages":"53-61"},"PeriodicalIF":0.0,"publicationDate":"1999-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/106161299320578","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21063933","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":"A controlled comparison of two different clinical grade devices for CD34+ cell selection of autologous blood stem cell grafts.","authors":"B Björkstrand,&nbsp;B Sundman-Engberg,&nbsp;B Christensson,&nbsp;G Kumlien","doi":"10.1089/106161299320596","DOIUrl":"https://doi.org/10.1089/106161299320596","url":null,"abstract":"<p><p>Six patients who were to undergo autologous PBSC transplantation with positively selected CD34+ cells were included in this study to compare the efficiency of two devices for clinical grade stem cell selection, the Isolex 300i (Baxter, Munich, Germany) and CEPRATE SC (CellPro, Bothell, WA). PBSC were mobilized by chemotherapy and G-CSF and were collected by leukapheresis on a CS3000 cell separator on 2 consecutive days. The two apheresis products were pooled for CD34 selection. The pooled apheresis products from each patient were divided into two equal portions to be separated on each of the two devices. Cell selection was performed according to the manufacturers' instructions. Enumeration of CD34+ cells was performed by flow cytometry using the HPCA-2 MAb. Purity and yield were significantly better with Isolex than with CEPRATE. Median purity was 93.0% (range 80%-98%) for Isolex and 61.5% (range 27%-72%) for CEPRATE (p = 0.03); median yields for Isolex and for CEPRATE were 48.0% (range 18%-73%) and 23.0% (range 17%-29%), respectively (p = 0.03). The number of CD34+ cells/kg body weight was also significantly higher with Isolex (median 3.8x10(6), range 1.7-5.2) compared with CEPRATE (median 2.35x10(6), range 0.7-4.3) (p = 0.03). Thus, the Isolex 300i device gave products of higher purity and recovered a higher proportion of the CD34+ cells in the harvest before separation. The yield was still poor with both devices, however, and further optimization of the technique for clinical grade stem cell selection is warranted.</p>","PeriodicalId":77208,"journal":{"name":"Journal of hematotherapy","volume":"8 1","pages":"75-80"},"PeriodicalIF":0.0,"publicationDate":"1999-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/106161299320596","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21063935","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":"Reproducible scoring of CFU-GM and BFU-E grown in collagen-based semisolid medium after a short (3 h) training.","authors":"I Dobo,&nbsp;J M Bidet,&nbsp;S Acquart,&nbsp;A Allegraud,&nbsp;L Amiot,&nbsp;C Boccaccio,&nbsp;N Boiret,&nbsp;J Domenech,&nbsp;P Mossuz,&nbsp;L Sensebe,&nbsp;E Wunder,&nbsp;M Zandecki,&nbsp;S Hermouet","doi":"10.1089/106161299320569","DOIUrl":"https://doi.org/10.1089/106161299320569","url":null,"abstract":"<p><p>Colony counting remains an important source of variation in colony-forming unit-granulocyte-macrophage (CFU-GM) assays performed in methylcellulose or agar. We studied the reliability of colony scoring of CFU-GM assays carried out with collagen, a matrix that allows gel collection on glass slides and in situ cellular morphology. Fourteen slides were exchanged among laboratories, and two rounds of colony (CFU-GM and burst-forming units-erythrocyte [BFU-E]) counting were performed by 11 (first counting), then 8 (second counting) different laboratories, the majority of which had no previous experience of collagen gel cultures and reading. Two-way analysis of variance (ANOVA) of the first round of colony counting showed significant differences among centers in CFU-GM counts (p = 0.023) but not in BFU-E counts (p = 0.163). Coefficients of variation for the 14 slides ranged from 22% to 50% (median 28%) for CFU-GM counts and from 12% to 74% (median 23%) for BFU-E counts. After a 3 h session of collective colony reading attended by members of 8 laboratories, a second round of colony counting was performed. This time, ANOVA showed no significant difference among centers for CFU-GM (p = 0.533) and BFU-E (p = 0.328) counts, and coefficients of variation were significantly improved, with medians of 17% for CFU-GM counts and 20% for BFU-E counts. In addition, when data from the second round of readings were analyzed without the 2 centers counting consistently low (center 8) or consistently high (center 5), variance among centers was further improved for both CFU-GM (p = 0.798) and BFU-E (p = 0.619). In summary, this study shows for the first time that reproducible BFU-E and CFU-GM scoring can be achieved using collagen-based semisolid medium (now commercially available) as long as adequate training in colony identification is provided.</p>","PeriodicalId":77208,"journal":{"name":"Journal of hematotherapy","volume":"8 1","pages":"45-51"},"PeriodicalIF":0.0,"publicationDate":"1999-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/106161299320569","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21063932","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":"Chronic myelogenous leukemia: from pathogenesis to therapy.","authors":"C M Verfaillie","doi":"10.1089/106161299320523","DOIUrl":"https://doi.org/10.1089/106161299320523","url":null,"abstract":"CHRONIC MYELOGENOUS LEUKEMIA (CML) is a malignancy of the hematopoietic stem cell (HSC) (1) characterized by the Philadelphia chromosome (Ph) (2). The Ph is the result of a translocation between chromosomes 9 and 22, resulting in the formation of a hybrid BCR/ABL gene on chromosome 22 (3). The p210BCR/ABL oncoprotein is necessary and sufficient for transformation. Introduction of BCR/ABL into hematopoietic cell lines renders them cytokine independent in vitro and tumorigenic in vivo (4,5). Transplantation of BCR/ABL-transduced murine HSC causes a CML-like syndrome (6±8), and transgenic expression of BCR/ABL induces leukemias and lymphomas (9,10). Although these studies show the transforming potential of BCR/ABL, they do not explain the typical clinical features of CML. The clinical syndrome of CML can be summarized as an (a) abnormal, unregulated expansion of Ph1 progenitors and precursors (b) affecting the myeloid but not erythroid or lymphoid lineages, (c) which circulate prematurely in the peripheral blood and home to extramedullary locations and (d) demonstrate a tendency to acquire additional molecular defects, leading to blast crisis over a period of 3±5 years (11,12). In this article, we review the molecular pathways that are affected by the BCR/ABL oncoprotein and how this may explain the clinical features of the disease. We also discuss ongoing and future therapeutic approaches for CML that are based on our current understanding of the pathophysiology of CML.","PeriodicalId":77208,"journal":{"name":"Journal of hematotherapy","volume":"8 1","pages":"3-13"},"PeriodicalIF":0.0,"publicationDate":"1999-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1089/106161299320523","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21064529","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}