摘要:

AbstractCellular transformation may be accomplished in vitro and in vivo through the concerted action of growth factors and oncogenes. This association has demonstrated that malignant growth results from aberrations in growth factor‐signal transduction pathways that normally operate to control proliferation. Activation of genes that code for growth factors and/or their receptors provides tumor cells with potential mechanisms to maintain their proliferative state.Tumor cells have been shown to produce endogenous substances that augment their growth (autocrine stimulation), as well as responding to exogenous substances (paracrine stimulation). With solid tumor cells these responses have been shown to involve aberrant expression of growth factor and/or receptor genes. The study of the interrelationship of these various growth regulatory molecules is important not only in the identification of gene products essential to cellular proliferation, but also in providing clues as to what forces are driving tumor cell growt

ISSN:0737-1454    

DOI:10.1002/stem.5530040401

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractIn mammalian ontogeny, the liver constitutes the primary hematopoietic organ for some time. Fetal liver cells (FLC) are rich in hematopoietic stem cells with a high proliferative potential but contain few post‐thymic T cells. In animal studies, FLC restored hematopoiesis without severe graft‐versus‐host disease. However, genetic disparity between donor and host frequently limited durable engraftment and prevented or protracted complete immune reconstitution in most fully allogeneic recipients. Some children with severe combined immunodeficiency have been cured by FLC infusion, whereas favorable effects in aplastic anemia, acute leukemia, and inborn errors of metabolism have been limited and badly understood. Fetal liver transplantation in animals may serve as a model for the analysis and management of complications associated with the transfer of purified hematopoietic stem cell grafts and aid in the development of future therapeutic strategies requiring rapidly proliferating stem cell popula

ISSN:0737-1454    

DOI:10.1002/stem.5530040402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractAutologous bone marrow transplantation (ABMT) in chronic granulocytic leukemia (CGL) aims at reversing the acute or acceleration phases by injection of stem cells collected during the chronic phase. This study was designed to explain an unusual rate of delayed engraftment (50%) in our experience of ABMT in CGL patients. We investigated all the factors possibly responsible for abnormal perpetuation of aplasia following infusion of cryopreserved marrow stem cells. The study of CFU‐gm recovery in 41 bags of frozen marrow from 25 patients revealed an overall deficiency with a mean CFU‐gm recovery of 55 ± 38% in CGL patients versus 73 ± 15% in the control group (p<0.001). Our data also showed an inverse linear relation (r = –0.40,p<0.05) between CFU‐gm concentration and recovery after freezing. A good CFU‐gm recovery (≥ = 50%) was observed in 70% of cases when the concentration was less than 3700 CFU‐gm/ml as compared to 30% of cases when the concentration was over 3700 CFU‐gm/ml (p<0.001). The lack of improvement by diluting rich CFU‐gm marrows to reduce CFU‐gm concentration/ml, as well as the absence of relationship between CFU‐gm recovery after freezing and nucleated cells concentration, suggest a particular fragility of CGL stem cells to freezing, probably related to their excessive amplification. At the present time, we strongly recommend that the highest possible dose of progenitor cells be cryopreserved, preferably at a low concentration, in patients with CGL, and particular attention devoted to the freezing procedure in each individual patient, with numerous appro

ISSN:0737-1454    

DOI:10.1002/stem.5530040403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractA long‐term culture of bone marrow lymphoblasts in a case of unclassified acute lymphoblastic leukemia is described. Cells lacking any lymphocytic marker in the early phaseof the culture were gradually substituted by B cells showing a pattern of polyclonality.The culture supernatant contained high levels of immunoglobulins also showing interleukin 2 activity. Search for antigens related to the Epstein‐Barr virus was negative.A clonal expansion of B cells versus spontaneous differentiation of unclassified leukemic cells is discussed; the long‐term culture technique as a tool for a better evaluation of leukemic cells is suggested and disc

ISSN:0737-1454    

DOI:10.1002/stem.5530040404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractIn order to evaluate the possibility of a patient with thalassemia finding an HLA‐identical sibling donor, we performed an analysis of HLA antigens in families of thalassemic patients.The pattern distribution was not significantly different from the expected ratio 25:50:25. When the siblings were subdivided according to the age of the patients (under or over 5 years), the above pattern remained unmodified for both the age groups.The average size of the 129 thalassemic families was 2.4. Thus, taking into account that thalassemic patients have an average of 1.4 siblings and that the HLA genotype distribution is expected as such, HLA‐matched siblings are available for 33% of the patients.Because an additional 8.5 % of the patients were found HLA‐phenotypically identical to one parent, the chance for a patient with thalassemia to find a suitable donor for bone marrow transplantation would be increased to 41.5 %.Our preliminary data cannot be extrapolated to the overall Italian thalassemic population; however, it can be inferred that for a patient with thalassemia, the chance of finding a suitable donor for bone marrow transplantation is not re

ISSN:0737-1454    

DOI:10.1002/stem.5530040405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractCell cycle times of cells derived from human hemopoietic progenitor cells were measured directly by using 5‐bromodeoxyuridine (BrdU) incorporation and sister chromatid differential staining. Umbilical cord cells were cultured in the mixed‐colony assay for 96 h prior to the addition of BrdU and then harvested at 6–12 h intervals. Individual cell cycle times ranging from 8.5–23.4 h were observed while population mean cell cycle times ranged from 17.5–24 h. These results show that some early progeny of hemopoietic progenitor cells have short cell cycle times and that there is considerable heterogeneity within the proliferating cell p

ISSN:0737-1454    

DOI:10.1002/stem.5530040406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

ISSN:0737-1454    

DOI:10.1002/stem.5530040407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY