摘要:

A routine in situ hybridization method is described and discussed, which allows parallel detection of repeated DNA sequences and of their abundant transcripts in consecutive tissue sections of a same biological sample with a unique probe. The protocol, based on the use of classical 3H‐labelled nick translated cloned DNA probes and of conventional paraffin sections of ethanol‐acetic acid‐fixed tissues, consists of a simple combination of procedures in current use for separate detection of either RNA or DNA. Different treatments recommended in other methods are omitted or simplified, making the protocol suitable for routine use. The method is successfully applied here to a test‐system where ribosomal sequences are sought in the ovarian follicles of the Lepidopteran Ephestia kühniella, by using a recombinant plasmid containing a Drosophila melanogaster rDNA repeating unit as a probe. Specific and reproducible results are obtained. Sensitivity is sufficient though moderate specific activities are used. Background level is very low. The regionalized distribution of sequences of both types in the chosen model allows to demonstrate that specific detection of RNA requires the systematic removal of DNA from the tissue sections prior to hybri

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1985.tb00349.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The effects of chloroquine and vinblastine (10‐100 microM) on insulin degradation and biological action were studied in cultured foetal rat hepatocytes. Insulin degradation, as measured by the release of trichloroacetic acid‐soluble radioactivity from 125I‐insulin into the medium, was strictly cell‐associated, saturable with respect to insulin concentrations and linearly related to the amount of cell‐associated hormone. The maximal rate of insulin degradation was 4,700 molecules/min per cell, and its KM about 5 nM. Thus, insulin receptors (30,000 sites/cell; half‐life close to 13 hr) must be reutilized 450‐fold before being degraded with an average time of reutilization inferior to 10 min. In the presence of 70 microM chloroquine or 100 microM vinblastine, insulin degradation was inhibited by 80% and the amount of cell‐associated hormone enhanced 2‐3‐fold. Nearly total inhibition of insulin‐stimulated glycogenesis was obtained with 70 microM chloroquine and 45 microM vinblastine. When hepatocytes were preincubated with chloroquine or vinblastine, insulin binding remained high for up to 4 hr, then progressively decreased thereafter. The addition of 10 nM native insulin during preincubation with the drugs resulted in an earlier and more pronounced decrease in insulin binding, whereas native insulin alone did not induce any change. Both the inhibition of insulin degradation and onset of receptor down‐regulation suggest a drug‐induced impairment in the receptor reutilization. This defect is correlated to a loss of the glycogenic effect of insulin in cultur

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1985.tb00350.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Clostridium difficile is the major etiologic agent of human pseudomembranous colitis. It produces two toxins: an enterotoxin and a cytotoxin. In cultured hepatoma cells, at very low doses, the cytotoxin inhibits the incorporation of precursors into biological macromolecules. Protein synthesis is more affected than RNA and DNA synthesis. The toxin also induces severe alterations of the cell morphology consisting in damages to the cytoskeleton and to the cell shape.

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1985.tb00351.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The depletion of polyamines by alpha‐difluoromethylornithine (DFMO) treatment of mice after subcutaneous inoculation of adenocarcinoma M3 cells caused a remarkable inhibition in the growth rate of primary tumors as well as in the occurrence and number of lung metastases with a concomitant increase in survival time. Tumor‐bearing mice submitted to the surgical removal of primary tumors and then treated with alpha‐difluoromethylornithine also showed a significant reduction of lung metastases. In addition, a lower number of lung metastatic nodules correlated with decreased levels of polyamines in the same tissue. The described approach provides a useful experimental model for studies in human cancer th

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1985.tb00352.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Antibiotics and dyes which preclude growth of Saccharomyces cerevisiae in media containing oxidizable carbon sources arrested the growth of Candida albicans, Candida tropicalis and Candida utilis even in glucose medium. The growth in the presence of sub‐inhibitory concentrations of the various antibiotics and dyes determined a reduction in the cell survival but with no accumulation of respiratory deficient mutants. Under these culture conditions, the total respiration declined leaving a residual antimycin A‐resistant—hydroxamate‐sensitive O2 uptake, and the amount of the respiratory cytochromes aa3 and b synthesized was reduced. SDS gel electrophoresis of soluble proteins prepared from the antibiotic‐treated cells showed some bands in the MW range 92‐100 K, which became faint after the cells were grown in the presence of some mitochondrial inhibitors. The ultrastructural analysis of these cells evidenced disappearance of the mitochondrial cristae and their replacement by unfolded membranes. The data obtained suggest that the petite negative trait of Candida could depend on the non‐viability or on the very low viability of those cells which have lost their mitochond

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1985.tb00353.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Six nervous system drugs which inhibited vegetative reproduction of S. cerevisiae arrested also mitotic division of C. utilis, C. albicans and C. tropicalis. Chlorpromazine and chlorpheniramine which proved to be the most effective, affected respiration and cytochrome biosynthesis. Electrophoretic bands with MW congruent to 100 K were faint in silver‐stained electrophoregrams of proteins from cells grown in the presence of a sub‐inhibitory concentration of chlorpromaz

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1985.tb00354.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Propionate and pyruvate added to isolated normal and biotin‐deficient adult rat hepatocytes increase the production of glucose. This production decreases about 30% on biotin deficiency. Malonate inhibits gluconeogenesis from propionate showing the metabolic transformation of propionyl‐CoA via the Krebs cycle. Neither glucagon nor dibutyryl‐cyclic AMP significantly stimulate gluconeoge

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1985.tb00355.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Gold immunolabeling of bovine lens tissue embedded in Lowicryl K4M, using a polyclonal antibody specific for a major component of lens fiber plasma membrane of 26 K molecular weight, shows that this constituent is absent from the epithelial cell plasma membrane and associated only with the junctional and non‐junctional domains of the lens fiber plasma membran

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1985.tb00356.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

In human lymphocytic metaphasis chromosomes sodium glycocholate induces a banding of chromatids and an intense apparently perichromatic labelling, reproducible on the same points of various chromosomal pairs. Arginine makes centromeric heterochromatin visible.

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1985.tb00357.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY