ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1986.tb00484.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The distribution of the herpes simplex virus alkaline nuclease (HSV DNase) in rabbit fibroblast cells infected with HSV type 1 or 2 (HSV‐1 or HSV‐2) has been examined with the aid of immunocytochemical techniques using gold particles as markers. HSV DNase was found to be accumulated within infected nuclei as early as 2.5 hr post‐infection. Labeled antibody to HSV DNase subsequently increased in all nuclei after 7 hr and 17 hr. At all times post‐infection the virus induced nuclear dense bodies were always the most intensely labeled structures. The association of HSV DNase with nucleoprotein containing structures was readily dissociated by hypotonic shock and detergent treatment, but its association with the dense bodies was not disrupted. Nucleolar 100 kDa protein was found to be simultaneously present in the dense bodies. This suggests that HSV DNase might interfere with ribosomal RNA synthesis and play a role in the degradation of the host‐cell m

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1986.tb00485.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Administration of the antimicrotubular agent colchicine to adult rats (0.5 mg/100 g of body weight for 6 hr) induces formation of extended aggregates of tubular, vesicular, and cisternal organelles in the absorptive cells of the small intestine. The phosphatase reaction pattern (thiamine pyrophosphatase, acid phosphatase, acid trimetaphosphatase) suggests that the majority of them belongs to the lysosomal system (Ellinger and Pavelka, 1984). The present study extends these findings and examines the uptake and fate of intravenously injected horseradish peroxidase (HRP) at the basal and lateral cell surfaces and of intraluminally applied HRP at the apical cell surface. HRP, applied to control animals and animals pretreated with colchicine, was internalized at both apical and basolateral cell surfaces of the absorptive cells, and delivered into endosome‐like vesicles, multivesiculated bodies (mvbs), dense bodies (dbs), and in several instances into Golgi cisternae. Following intraluminal application, evidence was obtained for the transport of HRP across the cell; in contrast, intravenously applied HRP was never detected at the apical cell surface. Colchicine pretreatment did not stop the uptake of HRP, which was rapidly sequestered to the clustered tubules, vesicles, and cisternae, as well as to the mvbs and dbs. After longer intervals, the portion of HRP‐reactive tubules, vesicles, and cisternae within the clusters increased: 60 min after HRP‐administration all of them contained HRP‐activity. These results indicate that the colchicine‐induced clustered organelles are recipients of endocytic materials internalized at the apical as well as at the basolateral cel

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1986.tb00486.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Cilia from quail oviduct were isolated with their membrane. The ultrastructural study revealed a good preservation of cilia in the purified fraction. Electrophoresis on SDS‐PAGE showed a reproducible pattern of ciliary proteins, the major bands being those of tubulins 57 kDa and dyneins above 250 kDa. Among the minor bands, an immunological study was focused on a 43 kDa molecular mass protein, using monospecific antibodies against actin. Presence of actin was then detected by immunoblotting of isolated cilia fractions as well as of demembranated cilia, suggesting that actin is associated with the axoneme. The presence of actin in the cilia was confirmed by immunofluorescence. The cilia were found stained only on the proximal part, suggesting an heterogeneous distribution of actin within the axonemal lengt

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1986.tb00487.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Fetal hepatocytes cultured in medium supplemented with fetal calf serum (FCS) or Ultroser SF do not maintain production of albumin or transferrin beyond one week of culture. When dexamethasone (10(‐7) M) is present, secretion of albumin and transferrin can be extended to two weeks, however, levels are extremely low. By three weeks, neither plasma protein can be detected in the culture medium in either conditions of culture. In contrast, hepatocytes maintained in medium supplemented with Ultroser G continue to produce albumin and transferrin at high levels for the entire three week period of this study. The morphology of the cultures are different. In FCS and Ultroser SF supplemented medium there are many more fibroblast and epithelial‐like cells and relatively fewer cells which are distinctly hepatocytes when compared with Ultroser G supplemented medium. The level of tyrosine aminotransferase, which is a dexamethasone inducible enzyme, is found to be much higher in Ultroser G cultures, with no further increase demonstrable by addition of dexamethasone. In contrast, dexamethasone induces the enzyme by about eight‐fold in cultures maintained in FCS supplemented medium. Therefore it appears that Ultroser G already contains sufficient steroid activity to maximize the level of tyrosine aminotransferase. A comparison between Ultroser C and SF (steroid‐free) suggests that the mixture of steroid and steroid derivatives in the G formulation must be important in the maintenance of differentiated functions of hepatocytes in culture. However, supplementation of FCS cultures with dexamethasone, which is known to be present in Ultroser G, does not allow hepatocytes to retain their differentiated functions over an extended period. Therefore it is concluded that other components besides dexamethasone must be im

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1986.tb00488.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Several strains of Candida parapsilosis, isolated independently in our laboratory, had their resistance compared to a series of inhibitors which act either at the level of mitochondrial ribosomes (chloramphenicol, erythromycin, paromomycin) or at the level of mitochondrial respiration and oxidative phosphorylation (oligomycin, antimycin A, diuron, carbonylcyanide m‐chlorophenylhydrazone). Cells were grown on glycerol media supplemented with one of these inhibitors, and it was demonstrated that the resistance of these yeasts to a large spectrum of antibiotics was due to several features: a resistance to oligomycin was found at the permeation level; the resistance to the other drugs was correlated to the relative insensitivity of cytochrome biosynthesis to the drugs; the cells developed, at the same time, two types of alternative pathways: the one branched at the ubiquinone level which drove electrons from Krebs cycle substrates to oxygen, and the other, antimycin A‐insensitive but inhibited by amytal, salicylhydroxamic acid and high cyanide concentrations. This secondary mitochondrial pathway, driving reducing equivalents from cytoplasmic NADH to cytochrome c and then to cytochrome aa3 or to alternate oxidase, allowed the growth of Candida parapsilosis on a non fermentescible medium, supplemented with these dr

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1986.tb00489.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Isolated cortices from sea urchin eggs accumulate calcium in a non‐mitochondrial store at a rate dependent on ATP and enhanced by oxalate. Calcium efflux is increased by ionomycin and by A23187 which has been used as a parthenogenetic agent, but not by weak base (NH4Cl). Accumulated calcium is partially released by 1,4,5 inositol triphosphat

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1986.tb00490.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Human gingival cells were collected using an enzymatic procedure and seeded on a feeder layer of irradiated mouse 3T3 fibroblasts. Epithelial cells generate stratified colonies ultimately forming an epithelium which was studied using electron microscopy. When this epithelium‐like structure was dispased and transferred to enamel surfaces, the relationship between basal cells and enamel corresponded to half‐desmosomes and a discontinuous extracellular mat

ISSN:0248-4900    

DOI:10.1111/j.1768-322X.1986.tb00491.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY