摘要:

AbstractA non‐histone protein with mol. wt of 48 000 differentially expressed in normal and tumour cells was identified using immunological criteria. Antibodies were raised against a component specific for Kirkman‐Robbins hepatoma of mol. wt about 48 000 separated from hepatoma non‐histone proteins by preparative electrophoresis in polyacrylamide gel. It was demonstrated by immunoblotting that Morris hepatoma 7777 and Ehrlich ascites cells share an antigenic non‐histone protein with Kirman‐Robbins hepatoma. Tumour cells when compared with normal cells, i.e. hamster and rat liver, are characterized by significant enrichment of this component. Intracellular distribution of the polypeptide with mol. wt 48 000 suggests that this component may be a structural protein the biosynthesis of which increases or the antigenic determinants of which change in tum

ISSN:0263-6484    

DOI:10.1002/cbf.290080202

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractThis study was designed to evaluate the effect of adrenalectomy on growth of L1210 leukemic cells in ascites of BDF1mice. Varying doses of 1·5 × 104, 5·0 × 105, and 1·5 × 106viable tumour cells were inoculated intraperitoneally into groups of either adrenalectomized or sham‐operated mice. At days 4 to 7 after the inoculation, adrenalectomized mice inoculated with 1·5 × 104or 5·0 × 105tumour cells had a smaller number of tumour cells in ascites than sham‐operated controls. However, after inoculation of 1·5 × 106cells, no significant differences were found at days 2 to 4 between adrenalectomized and sham‐operated mice. The growth retardation by adrenalectomy was not observed in adrenalectomized mice supplemented with 4 or 6 μg dexamethasone per day per mouse. It suggested that the ablation of glucocorticoids was at least partially responsible for the growth retardation observed in adrenalectomized mice. Cell kinetic analysis revealed that the difference in a potential doubling time could not explain these results. Tumour retention in the peritoneal cavity was measured using [125I]‐iododeoxyuridine‐labelled tumour cells as a tracer. At days 4 to 6 after inoculation of 5·0 × 105labelled cells, radioactivity in the peritoneal cavity in adrenalectomized mice was about 70 per cent of that in sham‐operated mice. This ratio was almost equivalent to the ratio of the number of cells in ascites of adrenalectomized mice to that of sham‐operated ones. Consequently, growth retardation observed in adrenalectomized mice resulted from an increase in tumour cell migration and/or in tumour cell death, but not from

ISSN:0263-6484    

DOI:10.1002/cbf.290080203

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

Abstract4‐Hydroxynonenal, which is one of the most important products of lipid peroxidation, alters microtubular organization and structure in 3T3 fibroblasts. Changes in cell shape and the disappearance of microtubules are observed by immunofluorescence after incubation with the aldehyde, and the colchicine binding activity of tubulin from 3T3 cells is modified. Moreover, the aldehyde determines a decrease in the ability of purified tubulin to polymerize and to bind colchicine. These effects may be related to the interaction of the aldehyde with functional ‐SH groups of tubulin which are necessary for protein integrity and functions. Indeed, the addition of cysteine protects against the damaging effects of the aldeh

ISSN:0263-6484    

DOI:10.1002/cbf.290080204

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe subcellular distribution of newly absorbed iron in isolated mouse duodenal enterocytes was investigated by analytical subcellular fractionation using sucrose density gradient centifugation. Two major peaks of mucosal59Fe activity were observed: one soluble and one particulate (density 1·18–1·20 g ml−1). The latter was increased following prior exposure of animals to chronic hypoxia. The particulate59Fe was localized to the basolateral membranes using the marker enzyme Na+, K+activated, Mg2+dependant, ATPase and by washing intact enterocytes with the selective plasma membrane perturbant digitonin.The basolateral membrane can be selectively labelled byin vitroincubation of intact enterocytes at 0°C with59Fe(III)‐nitrilotriacetate complex, confirming the presence of a59Fe binding site on this membrane. No significant difference inin vitroiron binding to this site was observed between normal and chronically hypoxic animals. Iron binding to the basolateral membrane was significantly higher in disrupted, compared to intact enterocytes, indicating that this site is present on both sides of the basolateral membrane. It is therfore suggested that the increased labelling of this site in hypoxia,in vivo, is a consequence of an increase in a mucosal Fe pool which is available for binding to a membrane

ISSN:0263-6484    

DOI:10.1002/cbf.290080205

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractTo investigate how newly synthesized cardiac myosins are assembled into myofilaments, we analysed the distribution of newly produced α‐myosin heavy chain isozyme in sarcomeres by immunoelectron microscopy using a monoclonal antibody (CMA19), which is specific for α‐myosin heavy chain. Isozymic changes in myosin heavy chains from β to α type were induced in canine ventricular muscles and cultured ventricular myocytes by administration of 1‐thyroxine. We incubated the glycerinated ventricular muscles or cultured ventricular myocytes with the enzyme (horseradish peroxidase) labelled Fab fragment of CMA19. After the reaction with 3, 3′‐diaminobenzidine and osmification, we prepared ultrathin sections of the ventricular muscles or cultured ventricular myocytes and analysed their staining patterns by electron microscopy.There was apparent heterogeneity in the staining intensity of the myofilaments among different cells, among different myofibrils and even intramyofibrillarly. Higher magnification revealed that there were scattered foci of strong reaction which appeared to be foci of assembly of the newly synthesized α‐myosin heavy chain. Immunocytochemical study also showed heterogeneous reactions within myofilaments and that there were scattered foci of myofilament assembly, which were closely associated with polyribosomes producing newly induced α‐myosin heavy chain. These data suggest that newly synthesized cardiac myosins are assembled into myofilaments from the sites of synthesis, that is polyribosomes. This may explain the heterogeneity of the assembly pattern of newly synthesized cardiac myosins at th

ISSN:0263-6484    

DOI:10.1002/cbf.290080206

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe ultraviolet absorbing components of human cartilage have been measured by microspectrophotometry. The characteristics of the chondrocytes appeared to be identical, irrespective of the pathology. However the matrix of osteoarthritic cartilage contained components that absorbed maximally in the region of 270 to 250 nm; such components were not found in the matrix of cartilage of non‐arthritic joints. Substances that absorb maximally in this region of the ultraviolet could generate free radical

ISSN:0263-6484    

DOI:10.1002/cbf.290080207

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

ISSN:0263-6484    

DOI:10.1002/cbf.290080210

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

ISSN:0263-6484    

DOI:10.1002/cbf.290080212

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

ISSN:0263-6484    

DOI:10.1002/cbf.290080216

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

ISSN:0263-6484    

DOI:10.1002/cbf.290080201

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY