ISSN:0737-1454    

DOI:10.1002/stem.5530060302

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

年代:1988

数据来源: WILEY

摘要:

AbstractTumor cell heterogeneity has in recent years been the subject of numerous excellent review articles, but comprehensive reviews may not always distinguish between that which is known about tumors from direct observation and that which is inferred from the study of analagous systems. The purpose of this review is to describe what is known about cellular heterogeneity inhumantumors and to discuss current models of the pathogenesis of cellular heterogeneity in light of the evidence available from the study of human cancer.

ISSN:0737-1454    

DOI:10.1002/stem.5530060303

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

年代:1988

数据来源: WILEY

摘要:

AbstractPhase I and Phase II studies of recombinant human erythropoietin (rhEpo) were conducted in normal volunteers and in anemic patients with chronic renal failure on maintenance hemodialysis. Three hundred U/person of rhEpo was administered intravenously to healthy normal volunteers in the Phase I study, resulting in no subjective or objective changes. In the Phase II study, 66 patients with chronic renal failure on maintenance hemodialysis with less than 20% hematocrit values were treated with rhEpo in doses of 50 U/kg to 200 U/kg two or three times a week. Hematocrit values increased significantly during the 12 weeks, and the patients' conditions improved. Patients previously requiring blood transfusions became transfusion‐independent during our study. There were no obvious side effects, thus indicating the safety and efficacy of rhEpo in the anemia of chronic renal failur

ISSN:0737-1454    

DOI:10.1002/stem.5530060304

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

年代:1988

数据来源: WILEY

摘要:

AbstractPharmacologic modulators of cyclic 3′,5′‐adenosine monophosphate (cAMP) and calcium were added to cultures of bone marrow cells from normal cats and cats with retrovirus‐induced erythroid aplasia (EA). Treatment with the following reagents increased the number of erythroid progenitors (CFU‐e and BFU‐e) in cells from normal cats: isoproterenol, dibutyryl cAMP, forskolin, RO‐20–1724 and A23187. However, treatment of cells collected from viremic cats not only failed to enhance CFU‐e and BFU‐e but inhibited their growth. These studies suggest that EA is related to a non‐reversible block of primitive erythroid progenitors or to direct inhibition of B

ISSN:0737-1454    

DOI:10.1002/stem.5530060305

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

年代:1988

数据来源: WILEY

摘要:

AbstractTerminal cell differentiation usually results in an irreversible arrest in the G, phase of the cell cycle and loss of cell renewal ability. Human promyelocytic leukemia HL‐60 cells induced with 12‐o‐tetradecanoylphorbol‐13‐acetate (TPA) differentiate into monocytes/macrophages and accumulate in G1We determined the effect of TPA on the growth kinetics of a human leukemia cell line (KOPM‐28), which developed several of the characteristics of megakaryocytes in response to TPA, such as the surface antigen complex IIb/IIIa, platelet peroxidase and polyploidy. Cell growth was immediately and completely inhibited by TPA. Flow cytometric analysis of cellular DNA content revealed a gradual decrease in cells in G, and an accumulation of cells in G2. These data suggest that TPA prolonged G1and rapidly arrested the cells in G2. Synchronized cells were utilized to further analyze the rapid G2arrest. Cells arrested with aphidicolin at the G1/S interphase were released, and the effects of TPA (added at different intervals) on cell cycle progression were examined 14 h after release. The results showed that TPA added at the end of the S phase, as well as at the G1/S interphase incompletely but distinctly arrested cells in G2. Moreover, G2arrest was observed when TPA was added to cells released from a colcemid‐induced G2/M block, suggesting that cells already in G2were inhibited by TPA from moving through M to G1. Since some cells became multi‐nucleated in the course of incubation with TPA, this G2accumulation may have resulted at least in part from a prolongation of the phase or a transient G2block. These changes in cell cycle progression induced by TPA may be characteristic of and/or related to megakaryocytic differentiation of hemopoietic

ISSN:0737-1454    

DOI:10.1002/stem.5530060306

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

年代:1988

数据来源: WILEY

摘要:

AbstractTransforming growth factor‐alpha (TGFα) is a low molecular weight peptide that has been implicated in an autocrine growth‐stimulation of tumor cell lines in vitro. Although its mRNA has been detected in biopsies from human malignancies, the importance of an autocrine mechanism for the growth of human malignancies in vivo is unknown. The purpose of our study was to determine the effects of recombinant human TGFα (rhTGFα) on the in vitro growth of fresh human tumors using a capillary cloning system. Growth was detected in control capillaries in 17 of 47 specimens (36%) without rhTGFα.Further stimulation of 12 of these tumors with rhTGFα obtained a maximal effect at 0.1 to 1μg/ml. Stimulation by rhTGFα was concentration‐dependent with some tumors showing a biphasic response. Eight of 22 specimens not showing colony formation in control capillaries were recruited to form colonies by rhTGFα (p<0.005). Responsiveness to rhTGFα varied among individual tumors. In control experiments, rhTGFα failed to stimulate colony formation in three low‐passage fibroblast cell lines. Furthermore, three additional human tumor specimens with benign cytologic findings displayed no colony formation. We concluded that a subgroup of primary human tumors was sensitive t

ISSN:0737-1454    

DOI:10.1002/stem.5530060307

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

年代:1988

数据来源: WILEY

ISSN:0737-1454    

DOI:10.1002/stem.5530060308

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

年代:1988

数据来源: WILEY