摘要:

AbstractSince initial reports of use of a human tumor cloning system to predict response or lack of response of a patient's tumor to chemotherapy, there have been approximately 2,166 clinical correlations attempted. Overall, the percent true positives has been 69% while the percent true negatives has been 92%. Despite the high reliability of this system to predict patient response or lack of response, the cloning assay has not been put into general clinical use. Reasons for this include the past inability to grow a majority of the patients' malignancies and lack of controlled trials demonstrating an advantage of a cloning assay choice over a clinician's choice. Both of these problems are being addressed with greatly improved abilities to grow patient malignancies (70%‐80% of patients' tumors can now be grown in vitro) and the reporting of results of prospectively controlled randomized trials. It is likely that the most significant limitation for the human tumor cloning assay will be the lack of agents with in vitro activity. It is proposed that we are in the “sulfonamide era” of in vitro drug sensitivity testing of human tumors. It is unlikely any predictive assay will be of major utility until a more active spectrum of agents becomes available for in vitro testing and in vivo trea

ISSN:0737-1454    

DOI:10.1002/stem.5530050302

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

年代:1987

数据来源: WILEY

摘要:

AbstractIn vitro chemosensitivity assays based on colony counting are plagued by persistent incidence of false‐negative results. To avoid serious predictive errors, some investigators have utilized positive controls (known toxic compounds) as a quality control measure. Sodium azide (NaN3) at 6 mg/ml failed to inhibit colony formation in 17/35 (49%) assays; while in the thymidine incorporation assay, sodium azide was effective in inhibiting 124/131 (95%) specimens. Positive control substances for use in chemosensitivity assays must be carefully selected to insure accurate result

ISSN:0737-1454    

DOI:10.1002/stem.5530050303

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

年代:1987

数据来源: WILEY

摘要:

AbstractErythropoietin (Epo) titers in various hematological states were determined by a radioimmunoassay. Epo titers in patients with uremic anemia and iron deficiency anemia were inversely correlated with their respective hemoglobin concentrations. Epo titers in patients with uremic anemia were significantly lower than those in patients with iron deficiency anemia with comparable hemoglobin concentrations.

ISSN:0737-1454    

DOI:10.1002/stem.5530050304

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

年代:1987

数据来源: WILEY

摘要:

AbstractWe have studied the internalization of125I‐erythropoietin (Epo) and regulation of Epo receptors by the ligand in a murine erythroleukemia cell clone, TSA8. To determine internalization, a high‐salt acid wash was performed. Internalization of125I‐Epo was found in TSA8 cells as well as in fetal mouse liver cells (FMLC), although the percentage of internalized radioactivity reached 40% after incubation at 37°C for 150 min and was lower than that in FMLC. Exposure of TSA8 cells to unlabeled Epo resulted in a rapid, time‐dependent reduction in125I‐Epo binding activity. The net loss of the activity was related to the ambient Epo concentration and 5 × 10‐4M Epo induced approximately 80% loss of total binding capacity. Scatchard analysis of the binding data revealed that the high‐affinity receptor number was decreased but the affinity was increased in the Epo‐treated cells. In low‐affinity receptors, however, the receptor affinity was decreased and the receptor number was not changed much by preincubation with Epo. These results suggest that the decrease in125I‐Epo binding activity after preincubation with unlabeled Epo is mainly accounted for by a decrease in the number of high‐affinity receptors, and the high‐affinity receptors play an important role in the b

ISSN:0737-1454    

DOI:10.1002/stem.5530050305

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

年代:1987

数据来源: WILEY

摘要:

AbstractWe have examined the usefulness of a protoplast fusion technique as a tool to transfer cloned genes into hematopoietic cells. Protoplasts carrying cloned plasmids, which would express specific markers when successfully transfected into human cells, were prepared and fused with human leukemic cell line K562 cells using polyethylene glycol as a fusogenic factor.As a result, K562 cells fused with protoplasts containing a plasmid pSV2‐cat constructed to code for chloramphenicol acetyltransferase (CAT) expressed CAT activity efficiently. K562 cells were also readily transformed to geneticin‐(G418) resistant cells following fusion with protoplasts carrying a plasmid pSV2‐neo‐SV‐gpt, which confers the resistance of mammalian cells to G418 and mycophenolic acid. It was also demonstrated that the plasmid genome was stably integrated into the chromosomal DNA of G418‐resistant K562 cells.Our results proved that protoplast fusion could be used to study the specific expression and the biologic activities of cloned genes in human hematopo

ISSN:0737-1454    

DOI:10.1002/stem.5530050306

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

年代:1987

数据来源: WILEY

摘要:

AbstractThis paper describes a study of hematopoiesis in parathion‐treated mice. Adult mice (48 C57B1/6) were given a daily dose of parathion (4 mg/kg p.o.) or corn oil vehicle (5 ml/kg p.o.) for 14 days. During the pesticide and the examination period, treated animals showed no signs of poisoning and had normal body weights. On days 2, 5, 7, 9, 12 and 14 following parathion or corn oil, femoral marrow cells were assayed in vitro for granulocyte/monocyte (CFU‐gm), erythroid (CFU‐e and BFU‐e), megakaryocyte (CFU‐meg), stromal (CFU‐str) and multipotential (CFU‐mix) hematopoietic stem cells. Leukocyte counts were elevated on days 2 and 5, while platelet counts were not increased until day 12. No change was observed in either hematocrits or numbers of marrow cells. BFU‐e were reduced (23% of control) by day 7, then increased to 137% of control by day 14. CFU‐e were reduced (41% of control) on day 9, then increased to 71% of control by day 14. CFU‐mix were 130% of control (day 2), then declined to control values by day 5. On days 12 and 14, CFU‐mix colonies decreased to 40% of control. CFU‐str were reduced at all time points examined. CFU‐gm were 123%, 136% and 130% of control on days 7, 12 and 14, respectively, while CFU‐meg were increased (145% of control) on day 7. The data suggest that parathion alters the cloning potential of bone

ISSN:0737-1454    

DOI:10.1002/stem.5530050307

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe sera of 14 out of 48 patients with aplastic anemia and four out of nine patients with paroxysmal nocturnal hemoglobinuria (PNH) contained complement‐dependent hematopoietic inhibitory activity against allogeneic marrow progenitor cells. Some sera with hematopoietic inhibitory activity, however, demonstrated no effect on autologous marrow progenitor cells. Hematopoietic inhibitory activity was absorbed by pooled, packed platelets. Serum hematopoietic inhibitory activity was present in both IgM and IgG fractions. These data suggested that serum hematopoietic inhibitors are alloantibodies and might be associated with graft rejection in the transplanted marrow of patients with aplastic anemia and PN

ISSN:0737-1454    

DOI:10.1002/stem.5530050308

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

年代:1987

数据来源: WILEY

ISSN:0737-1454    

DOI:10.1002/stem.5530050301

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

年代:1987

数据来源: WILEY