摘要:

AbstractA tumor cell-associated protein, previously shown to be present in the circulation of carcinogen-treated and tumor-bearing animals and cancer patients, has now been identified in the cytosol of embryonic tissue. This oncofetal protein, which is absent from the plasma of normal animals, has been purified from the plasma of tumor-bearing rats by a series of steps including ammonium sulfate fractionation and chromatography on Sepharose CL-6B and on CM Affi-Gel Blue. The tumor and fetal-associated 60-kd rat factors appear to be identical based on their reactivity to polyclonal antibody produced against the tumor factor. The factor, assayed by its ability to induce the transport of RNA from isolated nuclei, is a phosphoprotein with a minimum molecular weight of 60,000, as determined by polyacrylamide gel electrophoresis. In its purified form it is phosphorylated in the presence of the catalytic subunit of heart muscle protein kinase and ATP but does not exhibit auto-phosphorylating activity. 32P-orthophosphate is also incorporated into the phosphoprotein in vivo.

ISSN:0735-7907    

DOI:10.3109/07357908409048516

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

摘要:

AbstractMultistage risk models provide a close fit to most age patterns of adult-onset cancers. Such models posit that a number of events must occur before some cell in a tissue is transformed from normal to neoplastic. When an approximate version of the models has been fitted to data, this number has been estimated to be about 4–6. In fitting the same approximate model to the age pattern of onset of colon cancer in bearers of the Familial Polyposis coli (FPC) gene, several authors have found that the number of stages estimated was about two to three fewer than those for colon cancer in the general population. However, when an exact multistage model is used rather than an approximation to it, this is no longer the case: the number of stages estimated from the general population becomes too large to be compatible with what is known about carcinogenesis from laboratory experiments, and the number estimated from FPC victims is larger than that for the general population.“Inherited-hit”models of the nature of the FPC gene may be correct at the cellular level, but multistage models as commonly formulated cannot be used on data on the age-onset patterns in populations of individuals to infer such mechanisms or estimate their parameters.

ISSN:0735-7907    

DOI:10.3109/07357908409048517

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

摘要:

AbstractThe chemical stability of doxorubicin in a variety of tissue culture media has been studied by thin layer chromatography (TLC). In all the media examined, authentic doxorubicin was converted to a chemically distinct form as evidenced by the failure of this form to migrate on TLC plates. The rates of conversion were rapid enough (t1/23 hr) to be of consequence in chemosensitivity determinations, especially if working solutions of doxorubicin were to be routineh made and stored in tissue culture media. The addition of certain antioxidants to media did not prevent the conversion of authentic doxorubicin. However, doxorubicin was quite stable in distilled water. No single component of media was found to be responsible for the conversion of authentic doxorubicin, although arginine, histidine, tyrosine, NaHCO3and Fe(NO:3):3could each generate a form of doxorubicin which did not migrate in TLC analysis. Purification of the non-migrating form of doxorubicin demonstrated that in vitro conversion resulted in considerable loss of lethality while antiproliferative activity was retained. These observations provide possible explanations for the variability in chemosensitivity determinations and may explain some of the failures to predict clinical responsiveness.

ISSN:0735-7907    

DOI:10.3109/07357908409048518

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

ISSN:0735-7907    

DOI:10.3109/07357908409048519

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

ISSN:0735-7907    

DOI:10.3109/07357908409048520

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

ISSN:0735-7907    

DOI:10.3109/07357908409048521

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

ISSN:0735-7907    

DOI:10.3109/07357908409048522

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

ISSN:0735-7907    

DOI:10.3109/07357908409048523

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor

摘要:

AbstractThe animal rights movement is described in detail elsewhere in this issue of Cancer Investigation in the paper by Trull and Kalikow. It is an effort that must be taken seriously.

ISSN:0735-7907    

DOI:10.3109/07357908409048524

出版商:Taylor&Francis    

年代:1984

数据来源: Taylor