摘要:

ABSTRACTHypothermic preservation of hepatocytes on gelatin gels allows hepatocytes to be stored for at least 9 days. The procedure is easy, inexpensive and does not require specialised equipment. The cells retain their morphology and are released as separate spherical entities by dissolving the gelatin layer at 37°. The recovered cells have an intact plasma membrane as judged by lactate dehydrogenase activity, attachment efficiency and subsequent monolayer formation in culture. Functional tests show that the cells recover quickly from the storage conditions. Rates of protein synthesis are maintained over a 6 day period and remain at 62% of the initial level on day 9. The liver specific, hormonal induction of the enzyme tyrosine aminotransferase is apparent throughout the culture period. In addition a phenotypic marker enzyme, γ‐glutamyl transpeptidase, remained at basal lev

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1023

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTElements controlling high expression of the 17‐1A antigen gene in pancreatic carcinoma cells (Capan 2) reside within the two regions: proximal (−193 to +3) and distal (−877 to −518). We demonstrate here that some factors present in nuclear extracts from nonexpressing cells bind specifically to the control elements, important for gene expression. Our results suggest that nonexpressing cells may either lack at least one of the factors necessary for activation or may contain their modified forms. A major difference between expressing and nonexpressing cells was found in the region containing core enhancer sequence. Moreover, nonexpressing cells display a complex pattern of DNA‐protein interactions in this region, suggesting that these cells contain factors acting negatively mainly on the enhancer sequence. Our results however, indicate that the mechanism of repression is much more complicated than

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1024

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTAntibodies to elongation factor 1α (EF1α), a known 50 kDa actin‐bundling protein in Dictyostelium, identified a protein in a whole cell extract of the characean alga Nitella pseudoflabellata that had an apparent molecular weight of 51 kDa. Indirect immunofluorescence microscopy revealed labelling by the EF1α antibodies of the subcortical actin bundles, even after the motile organelles of the endoplasm were removed by perfusion with ATP‐containing sol

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1025

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTProtease inhibitor preparations (PIP) with antitryptic and antichymotryptic activities, isolated from field bean legume as well as doxorubicin and cyclophosphamide could effectively suppress the growth of Yoshida sarcoma ascites tumor cells transplanted in adult rats and prevent their death. As against this, methotrexate and heat‐inactivated PIP were ineffective in such rats at varied doses of treatment tried. The percent survival of animals appeared to be related to the purity, treatment mode and the dose of PIP used. Zymographic analysis of the trypsin activated sarcoma cell homagenate revealed the presence of six protease bands in the molecular weight range of 51kD to 206kD. Prolonged interactions of such zymograms with protease inhibitors such as 20mM EDTA or 5mM diisopropyl fluorophosphate (DIFP) or 400 · μg/ml of PIP in reaction buffer indicated that these are not metalloproteases but serine proteases whose activities are inhibited by PIP and DIFP. Since proteases are involved in cell growth regulation and cell transformation, we hypothesize a positive relationship between the field bean protease inhibitor;s blocking action on tumor cell proteases and its tumor suppressing acti

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1026

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTA 170 kDa polypeptide that has been partially purified from mung beans is retained by ADPagarose even in the absence of divalent cations when most non‐myosin ATPases and kinases do not bind. Attempts to demonstrate a myosin‐like ATPase activity were inconclusive, however, and the protein accounts at most for only a small part of the total K+EDTA ATPase activity of mung bean extracts. All four monoclonal antibodies raised to the 170 kDa polypeptide react with rabbit skeletal muscle myosin and localize the 170 kDa polypeptide in mung bean root tip cells to the actin‐containing phragmoplast and to sites dispersed throughout the cytoplasm which probably include some but not all actin cables. These 4 monoclonals and 3 commercially available antimyosin monoclonals all recognise rabbit skeletal myosin and 160‐170 kDa proteins that are present in two other angiosperms tested. In addition, a 158 kDa protein of mung bean reacts with only one antibody and does not bind ADP‐agarose. We conclude that strong but not yet conclusive evidence points to the 160‐170 kDa proteins of angiosperms being a widely conserved form of myosin

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1027

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTAim of the study was the establishment of a standardized in vitro culture system for studies on proliferation and differentiation of human leukemic pre ‐ B cells. Coincubation with human stromal cells led to a significantly higher proliferation of the cytokine ‐ sensitive leukemic pre ‐ B cell line BLIN‐1. Clones from the murine fibroblast cell line L929 provided identical results. Coincubation with the murine cells also resulted in a significantly higher numbers of viable cells in 5 of 8 patient samples with newly diagnosed B lineage ALL. The results show that in vitro bone marrow stromal cells can be substituted by murine fibroblasts and form the basis for a simpler and more reproducible assay

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1028

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTTemperature of culture can be used to modulate cellular metabolism for improving small intestinal cell culture and cryopreservation. An hypothermia pretreatment (2 days at 25°C and 3 hours recovery at 37°C) improved hamster cell survival to freeze‐thaw damage (p<0.01) but decreased the survival of 2 immortal pig ileal cell lines even though epithelioid IPI‐2I cells were more tolerant to hypothermia than IPI‐I fibroblasts. Epithelioid cells survived 3 days at 25°C with unaltered expression of cytokeratin‐18 whereas colonies of fibroblasts did not survive more than a day at 25°C (p<0.001). These results suggest that hypothermia‐tolerance of pig ileal cell lines might differ according to cell lineage calling for further experiments on small intestinal primary

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1029

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTFollowing culture of human peripheral blood mononuclear cells (PBMNC) from 25 normal donors and 15 patients with common variable immunodeficiencv (CVID), we were unable to identify any IL10‐defective patients. Clear‐cut effects of IL4 could be demonstrated in controls, while in CVID all effects are less pronounced. While in both controls and CVID baseline levels of 1L6, IgG and IgM were found to be correlated, this was altered by the addition of either IL4 or Poke Weed Mitogen (PWM). We therefore conclude that the inability of PBMNC to produce IL10 is not the cause of CVID in our patients. In CVID, the regulating circuitry triggered by IL4 remains principally intact, however, some subgroups of CVID behave significantly differen

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1030

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTPrometaphase PtK1cells are treated with low concentrations of sucrose in order to analyze its effects on kinetochore structure, microtubule (MT) associations with the developing kinetochore and chromosome congression. Prometaphase cells treated with 0.15M sucrose slows chromosome congression, yet chromosomes form a metaphase configuration. However, 0.2M sucrose treatment prevents chromosome congression and affects some of the kinetochore MT linkages with the kinetochore, resulting in loss of chromosome congression. We use time lapse video microscopy and ultrastructural analysis to correlate changes in the linkages in the kinetochore MTs and the kinetochore to explain these findings. It appears hyperosmotic shock treatment can produce non‐functional linkages between kinetochore MTs and kinetochores such that chromosome congression is affected. When non‐functional linkages are formed, the presence of both a corona and matrix‐like material is also present, proximal to the kinetochore. The role of this material and its organization at the klnetochore is discussed in its relation to generating mitotic f

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1031

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

ABSTRACTCholesterol, triacylglicerol and phospholipid content was analysed in Xenopus embryos during their early development (from day 1 to day 6). Triacylglicerols decrease significantly during the analysed stages and this can be explained by their use as energy substrate. Cholesterol and phospholipids, on the contrary, remain constant and are probably redistributed inside the embryo. The different phospholipid classes were separated by HPTLC. A constant decrease of PC and a marked increase of PS has been observed. The fatty acid composition of the single phospholipid classes has been analysed.

ISSN:1065-6995    

DOI:10.1006/cbir.1994.1032

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY