摘要:

Sodium butyrate induced adhesion of cultured mastocytoma p‐815 cells to the surface of a standard tissue culture grade petri dish. The ratio of the number of adherent cells to that of total cells (adherent plus floating cells) was dependent on the serum concentration and on the dose of sodium butyrate. During approximately the first 6 hr after the addition of sodium butyrate, no cells adhered. The optimum conditions for adhesion were provided by 2 mM sodium butyrate and 15% fetal calf serum, 44 hr after addition of this compound. Morphologically, adherent cells consisted of spindle‐shaped and round cells: the latter clustered to the former. Low concentrations of actinomycin D (0.005 microgram/mL) and of cycloheximide (0.5 microgram/mL) inhibited cell adhesion. Adherent cells were easily detached by 0.25% trypsin‐0.02% EDTA but not by EDTA alone. Adherent mastocytoma cells which were cultured in the presence of 2 mM sodium butyrate, re‐adhered to the surface of the dish. The ratio of adhesion in the second dish, however, was very low (35% after 2 hr incubation). Radioactive iodinated surface proteins of butyrate‐treated adherent cells showed two new bands (70,000 and 92,000 D) which were not detected in control cells, but there was no difference in the extent of labeling of high molecular weight protein (250,000 D) between butyrate‐treated and co

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1984.tb00249.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Affinity toward each other was demonstrated in co‐cultures between HeLa cells and fibroblasts originating from human tumor stromal or normal tissues. Both cell types in the mixed cultures (ratio 1:1, 1:2, 2:1) proliferated normally as shown by 3H‐thymidine labeling index estimation for up to 48 hr of co‐culture. At ratios of fibroblasts: HeLa lower than 1:10, fibroblasts were eventually eliminated after serial passaging. It was shown that 3H‐nucleotides could be transferred between heterologous cells in either direction. Contact of cells was essential for this phenomenon. Transfer of the label from HeLa to fibroblasts required a longer interaction time and was evidently lower than the transfer from fibroblasts to HeLa. 3H‐thymidine incorporated into the DNA of either cell type could not be transferred from one cell to another. The model provides a means for studying neoplastic X normal (or tumour stromal) cell interactions

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1984.tb00250.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Using galactosylated bovine serum albumin coupled to colloidal gold (galBSA‐CG) as a probe, the receptor‐mediated endocytosis pathway has been analyzed qualitatively and quantitatively at the ultrastructural level in cultured rat hepatocytes. The results showed that galBSA‐CG was specifically recognized by the asialoglycoprotein receptor of the hepatocytes, thus confirming biochemical findings. The probe was preferentially bound in coated pits of the cell surface. When bound elsewhere on the plasma membrane, it apparently moved towards coated regions. In both cases, it was then internalized via coated vesicles. The galBSA‐CG passed through pleiomorphic tubular structures and in endosomes, a pool of smooth‐surfaced vesicles of various size (50‐350 nm), before transiently accumulating in multivesicular bodies. The latter then fused with lysosomes where the glycoproteinic moiety of the probe was degraded, as judged by the flocculated aspect of the accumulated gold particles. About 10% of the internalized ligand was recycled back to the cell surface via secreting vesicles containing lipoprotein‐like particles without having apparently passed through lysosomes, which suggests the existence of a pre‐lysosomal sorting mechanism of the endocytosed material. Functional recovery of the morphologically restored biliary polarity of hepatocytes in culture was indicated by the fact that galBSA‐CG finally appeared in the reconstitute

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1984.tb00251.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Human blood group A antigenicity of glycoproteins is retained on epon‐embedded jejunum sections after glutaraldehyde fixation and osmium treatment. The intracellular location of molecules bearing these determinants was visualized in the four types of epithelial cells of A+ rabbit jejunum sections with immuno‐colloidal gold labeling. The brush border membrane and in particular the glycocalyx of absorbing cells as well as the secretory granules of goblet and Paneth cells were heavily labeled. In enteroendocrine cells, the membrane of secretory granules and not their content was lightly labeled. The differential labeling of secretory or membrane bound glycoproteins is accompanied by different labels of the Golgi complex as expected if labeling of the Golgi saccules was due to the presence of glycoproteins in transit. In all cases the label is primarily concentrated in only half the cisternae on the trans side of the Golgi stacks. In absorbing cells, structures have been revealed in the terminal web that could be related to the brush border membrane and consequently implicated in its biogenesis. The fibrillar material of the glycocalyx appears as highly labeled tangled structures which apparently proceed from densely stained “carrier” vesicles arising from the Golgi apparatus. Vesicles fusing at the lower part of microvilli could result of integration of this material into the lightly labeled vesicles strictly found in the terminal web. These last vesicles could also contain newly synthesized brush border hyd

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1984.tb00252.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A quantitative ultrastructural study was performed on 56 ejaculates showing anomalies of the sperm axonemal complex. The anomalies comprised either the absence of one, or more often several, axonemal structures, or defective elongation of the doublets. Several characteristics relating to the extent and superimposition of the various anomalies could be described and enabled the definition of 6 groups of anomalies. In decreasing order of frequency these were: absence of the doublets and peripheral junctions, absence of the central complex, of the outer dynein arms, of the central junctions, of both dynein arms, and absence of the inner dynein arms and peripheral junctions. Some anomalies caused total immobility, whereas others caused abnormal movement patterns. Abnormalities of the peri‐axonemal structures were found in each group. The various light microscopic characteristics of each of the 6 groups represented 6 seminal profiles which should permit their detection during a routine semen analysis. Several specific associations of axonemal and/or peri‐axonemal anomalies would suggest some morphogenetic links between them. Relationships between the absence of doublets or the absence of the central complex and disturbances of microtubular polymerization are discussed. Finally, the study has provided new data on the composition of the axon

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1984.tb00253.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

In order to elucidate the function of the cytoplasmic core (or rachis: a structure specific of the nematode gonads), we have carried out a cytological study of this structure in the free‐living nematode Caenorhabditis elegans, in wild‐type and in several mutant strains showing an abnormal gametogenesis. We also performed an ultrastructural radioautographic study of RNA synthesis during oogenesis in order to examine the part played by the rachis in the transport of nutritive substances. Our results evidence for the first time a metabolite transfer from the germ cells to the cytoplasmic core and lead us to assign to the core a trophic role linked to oogenesis. A statistical analysis of silver grain distribution has led us to conclude that there is no accumulation of RNA labelling in any part of the cytoplasmic core. In addition, our studies performed on sterile mutant strains suggest that the cytoplasmic core may have a specific function in oogenesis determinat

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1984.tb00254.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Our double labelling method allows the junctional AChE and AChR distributions to be stained in the same preparation. This method which provides good definition of the fine morphology of synaptic structure and is capable of revealing a very weak AChE activity is of a particular value in studies of synaptogenesis.

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1984.tb00255.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The nucleolus of the human Sertoli cell consistently showed three distinct, spontaneously segregated parts: 1. one or two large, silver‐positive fibrillar centers; 2. strands of dense fibrillar component continuous with the dense cords surrounding the fibrillar center. These components were also silver‐positive; 3. a granular, silver‐negative mass. These observations show that in the human Sertoli cell the number of fibrillar centers is far lower than the diploid number of NORs. They also suggest that the fibrillar center might contain several NORs in this cell

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1984.tb00256.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY