摘要:

AbstractThe epithelial lining of the gastrointestinal (GI) tract is in a state of continuous cell renewal, and the proliferating and differentiating/differentiated cell populations are spatially clearly demarcated. Members of the epidermal growth factor (EGF) family of peptides, the trefoil peptides and enteroglucagon appear to be the most important enterotrophic molecules for both normal cell renewal and healing after cell damage. Transforming growth factor‐a (TGF‐a) appears to be the primary physiological ligand for the EGF receptor (EGFR), promoting normal cell renewal, and TGF‐a/EGFR are part of an autocrine loop in many intestinal cancers. In response to damage, a differentiating cell lineage arises from adjacent epithelium secreting EGF, TGF‐a and trefoil peptides; this may be viewed as part of a ‘repair kit’ in damaged endodermally‐d

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1001

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractESb and BW‐O‐Li1 are T‐lymphoma cell lines that form metastases in various organs after injection into syngeneic mice. In vitro, both cell lines invade through a fibroblastic monolayer, but ESb cells do so much slower than BW‐O‐Li1. By the use of Fourier analysis of cell outlines, we can relate this difference in invasiveness to a difference in cell motility: ESb cells do not perform any conspicuous shape change, whereas BW‐O‐Li1 cells are actively protruding and retracting large pseudopodia. However, the low‐motile ESb cells become as motile and deformable as BW‐O‐Li1 cells when they have eventually invaded under a fibroblastic monolayer. This indicates that ESb cells do have inherent capability for shape change. Treatment of ESb cells with the microtubule disrupting agent nocodazole concomitantly increases their shape change intensity, and their invasion rate through fibroblast monolayers. On the contrary, the microtubule stabilizing drug taxol inhibits both motility and invasion of BW‐O‐Li1 cells. Our observations suggest that the microtubule network can repress invasion‐bound m

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1002

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractHuman lymphocytes were used as an assay system to test chemopreventive activity of natural products. Purnark, a mixture of extracts of turmeric, betel leaf and catechu, was tested for its chemoprotective activity against BP induced DNA damage. Sister chromatid exchange and micronuclei were used as markers to assess the protective activity of Purnark. Purnark gave 50‐60 % protection against BP induced SCEs and micronuclei. Purnark at 1000μg dose did not show any genotoxici

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1003

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractSkin fibroblasts derived from Ehlers‐Danlos syndrome (EDS) patients lack an organized extracellular matrix (ECM) of fibronectin (FN) and often show an accumulation of cytoplasmic FN. The treatment of EDS cells of different types (I to VIII) with 10‐7M dexamethasone (dex), as well as cocultivation with control fibroblasts, induced in most cases the assembly of a FN‐like ECM. The study of FN mRNA expression by dot‐blot hybridization and of FN released into the culture media of EDS cells showed that the correction of the defective FN‐ECM of EDS cells by dex treatment is associated in most cases with an increase of FN mRNA synthesis and of se

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1004

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe sensitivity of cells to serum deprivation depends upon whether they are transformed. Most supplies of 3T3 cells are of this type and are considerably less sensitive than untransformed cells. In addition, the apparently simple manoeuvre of reducing serum levels has considerable effects on cell fragility, viability, growth rate and metabolism, which were found to be due to small changes in pH, substrate availability, cell density and other parameters, many of which cannot be attributed to the absence of growth factors from the medium. Supplementation of medium with bovine serum albumin (BSA) to compensate for low normal serum protein did not aid growth nor offset the disturbances caused by low serum levels themselves. Problems associated with the altered precursor availability for DNA, RNA and protein synthesis are also discussed.

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1005

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractMetallothionein presence and amount were determined in the unfertilized eggs of six sea urchin species by silver saturation assay and gel‐chromatography of cell extracts. The results showed high levels of metallothionein in the egg cytoplasm of the two Mediterranean species Paracentrotus lividus and Sphaerechinus granularis. No metallothionein was found either in the eggs of Arbacia lixula, or in those of the three Eastern species Strongylocentrotus intermedius, Temnopleurus hardwickii and Clypeaster japonicus. However, the extracts of the latter three species revealed the presence of zinc bound in a macromolecular form, thus suggesting the existence of metal‐binding proteins distinct from metallothione

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1006

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe presence of cytokine producing cells is most easily revealed by techniques measuring the secreted cytokines in culture supernatants or body fluids. However, these techniques only measure the bulk cytokine release by a given, often mixed cell population. To demonstrate cytokine production at the single cell level, immunocytochemistry (ICC) and in situ hybridisation (ISH) are now widely used techniques. To establish these techniques, an easily accessible model system is needed which permits the evaluation of different ICC and ISH protocols. It can be used to demonstrate the specificity of the antibodies and may serve as a positive control for samples of unknown cytokine content. Here we propose the use of Chinese hamster ovary (CHO) cells transfected to express one specific cytokine as such a model system. Its usefulness is demonstrated by the characterisation of six monoclonal antibodies to human interleukin‐4 and the establishment of two in situ hybridisation protocol

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1007

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1008

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1009

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1010

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY