ISSN:1065-6995    

DOI:10.1006/cbir.1994.1012

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTThe relationship between differentiation and concerted cell death was studied using ultrastructural, histochemical and immunochemical methods in solid rat fibrosarcoma Sa‐45 grown in the presence of demineralized bone matrix. The control tumour consisted mostly of undifferentiated cells with few poorly or moderately differentiated cells. In the presence of the inducer, cells with a more differentiated pattern appeared in the surrounding area. The proliferative activity in the presence of the inducer was 3 to 5 times lower but the apoptotic index was higher than in the controls. However, complete differentiation was induced only in stromal cells, whereas the parenchymal cells showed signs of enhanced but incomplete differentiation. The ultrastructural signs of programmed cell death progressed in them faster than the corresponding features of maturation, thus leaving differentiation incomplet

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1013

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTActivities of the ß‐glucuronidase (GUS) reporter enzyme were evaluated in transgenic plants, protoplasts, and intertypic heterokaryons ofSolanum tuberosumandNicotiana tabacum. With GUS under control of the promoter of the cauliflower‐mosaicvirus 35S RNA gene (CaMV), activities of the enzyme were nearly evenly distributed over the tissues of plants grownin vitro. Activities in microtubers of potato plants with the reporterenzyme under control of the promoter of granule‐bound starch synthase (GBSS) fromS. tuberosumwere higher than in leaves. The CaMV‐GUS construct present in leaf protoplasts showed an increased expression in biochemical and cytochemical assays after fusion with wildtype‐tuber protoplasts. Such an increase was not observed in the case of the GBSS‐GUS constructs. It was concluded that nuclei in plant heterokaryons are being influenced by the fusion partner, but that repressive,trans‐acting regulation factors in leaf protoplasts possibly prevent an increase of the expression of the chimeric GBSS‐gene

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1014

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTCultured vascular smooth muscle cells express distinct histological phenotypes due to a contractile to synthetic stage transition. In this study, we compared the behaviour of cultured aortic smooth muscle cells from young normal and mdx mice. Morphological, immunobiochemical, immunocytochemical analyses and contraction studies of these cells demonstrated that (i) the cell cytoskeleton in mdx mice is not affected by the absence of dystrophin since proteins such as caldesmon, a‐actin, and vinculin are expressed similarly in normal mice, (ii) utrophin (or dystrophin‐related protein) overexpression does not compensate for the physiological and functional role of the lacking dystrophin. These data suggested that dystrophin and utrophin cannot substitute one another and may play different or complementary roles within smooth muscle ce

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1015

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTThe relative importance of hydrogen peroxide generated as a consequence of irradiation with X‐rays for the production of chromosomal aberrations has been studied in cultured CHO cells. Catalase introduced into cells by electroporation protected DNA from strand breakage induced by hydrogen peroxide given 4h later, and the yield of chromosome aberrations was also reduced. Nevertheless, when the cells were irradiated after treatment with catalase following a similar protocol and the yield of chromosomal aberrations analyzed at metaphase, no protective effect was observed as compared with cells treated with X‐rays alone. These observations seem to support the hypothesis that hydroxyl radicals generated from hydrogen peroxide are not a major factor responsible for chromosome damage induced by ionizing radiat

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1016

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTThe influence of hyaluronan (HA) on the expression of human skin fibroblast elastase‐type protease (HSFEp) (Homsy et al, 1988) was studied. At confluency of HSF cultures, hyaluronan increased the level of HSFEp in a time and dose‐dependent fashion, Optimal effect was observed after 48 h of culture and at 2 mg/ml HA concentration; the stimulatory, effect of HA could be suppressed by 1 μM cycloheximide. The enhancement of enzyme biosynthesis by HA was dependent on cell proliferation but quasi invariant with HSF passage number (from 7

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1017

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTSynthetic medium collected from stationary phase cultures of Acanthamoeba castellanii can support limited growth of these cells if lipids are first extracted. Conditioned medium contains several lipids, both saponifiable and non‐saponifiable. Release of these lipids is probably mediated by release of microexudate, a large‐molecular complex with surface‐active prope

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1018

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTAcetylcholine (ACh) is believed to play a major role in the efferent vestibular system in several animal models, however no information regarding the role of ACh in the human efferent vestibular system has been published. Post‐embedding immunohistochemistry in a hydrophilic resin was used to investigate the choline acetyltransferase immunoreactivity (ChATi) and acetylcholinesterase (ACHE) histochemistry in human vestibular end‐organs. ChATi and AChE activity was found in numerous bouton‐type terminals at the basal area of the vestibular hair cells. These terminals were found to contact type II vestibular hair cells and the afferent chalices surrounding type I hair cells. This study provides the first evidence that the human efferent vestibular axons and terminals are cholin

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1019

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTCultured bovine aortic endothelial cells (BAEC) were incubated for 5 days with 10−54‐hydroxynonenal (HN). HN treated BAEC and controls were either (i) further incubated with125I‐polymyxin B (IPxB) or with radioiodinated, inactivated coagulation factor Xa (IFXai) as markers of membrane phospholipid perturbation, or (ii) assayed for the synthesis of prostacyclin (PGI2) and thromboxane A2(TXA2). Rabbit blood mononuclear cells enriched in monocytes (MC) were isolated and assayed for chemotactic response to HN. The results showed six ‐ fold increases of IPxB and IFXai binding to BAEC treated with HN, as compared to untreated controls. We also found in HN treated cells a marked inhibition of PGI2synthesis, but an unmodified TXA2production. In addition, HN in the 10‐5‐10‐10 M range induced oriented mi

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1020

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1021

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY