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31.
Ali H. Qizilbash 《CMAJ》1974,110(2):185-186
A case of early bilateral serous papillary adenocarcinoma of the ovaries in an asymptomatic 58-year-old woman was diagnosed by the discovery of psammoma bodies in routine cervicovaginal and endometrial smears. Multiple small foci of carcinoma in-situ involving both fallopian tubes were also present. The significance of psammoma bodies in the cervicovaginal smear is discussed and the literature on the subject briefly reviewed. 相似文献
32.
33.
The growth OfRhizoctonia solani in different carbohydrates was studied. The rate of growth of the fungus was traced by taking the dry weights of mycelia obtained from the carbohydrate medium at regular intervals and shifts in the pH were recorded. Different carbohydrate sources had different effects on the growth of the organism. The exoenzymes from the organism were capable of cleaving carbohydrates irrespective of whether the fungus grew in them or not. 相似文献
34.
Identification of a cDNA encoding a long form of prolactin receptor in human hepatoma and breast cancer cells 总被引:19,自引:0,他引:19
J M Boutin M Edery M Shirota C Jolicoeur L Lesueur S Ali D Gould J Djiane P A Kelly 《Molecular endocrinology (Baltimore, Md.)》1989,3(9):1455-1461
Human PRL receptor cDNA clones from hepatoma (Hep G2) and breast cancer (T-47D) libraries were isolated by using a rat PRL receptor cDNA probe. The nucleotide sequence predicts a mature protein of 598 amino acids with a much longer cytoplasmic domain than the rat liver PRL receptor. Although this extended region has additional segments of localized sequence identity with the human GH receptor, there is no identity with any consensus sequences known to be involved in hormonal signal transduction. This cDNA will be a valuable tool to better understand the role of PRL in the development and growth of human breast cancer. 相似文献
35.
On the mechanism of action of dexamethasone in a rat mast cell line (RBL-2H3 cells). Evidence for altered coupling of receptors and G-proteins 总被引:1,自引:0,他引:1
D Collado-Escobar H Ali M A Beaven 《Journal of immunology (Baltimore, Md. : 1950)》1990,144(9):3449-3457
Prolonged exposure of rat basophilic leukemia (RBL-2H3) cells, a cultured analog of rat mast cells, to 0.1 microM dexamethasone resulted in global suppression of various stimulatory events in response to Ag and a global enhancement of the same stimulatory events to the adenosine analog, N-(ethylcarboxamide)adenosine (NECA). We had previously shown that Ag and NECA both activate phospholipase C but by different mechanisms; cells that had been treated with cholera or pertussis toxin, for example, responded to Ag but not to NECA with the release of inositol phosphates, increase in levels of cytosolic Ca2+, and secretion. Because the toxins still inhibited the responses to NECA in dexamethasone-treated cells, the effects of dexamethasone may have been exerted at the level of receptor/G-protein coupling rather than at the level of effector systems. Additional evidence for this was the following: 1) NECA-induced hydrolysis of the inositol phospholipids was still enhanced after permeabilizing (with streptolysin O or Staphylococcus alpha-toxin) and washing the cells; 2) the response to the G-protein stimulant, guanosine 5'-(3-O-thio)triphosphate was also enhanced in permeabilized, dexamethasone-treated cells and 3) binding and kinetic studies suggested that the enhanced responsiveness to NECA was attributable in part to an increase in receptor number. The suppressive action of dexamethasone on Ag-induced hydrolysis of inositol phospholipids, however, was readily lost by permeabilizing RBL-2H3 cells. The results indicate, therefore, that treatment with dexamethasone leads to changes in receptor-coupling mechanisms that are either resistant to (i.e., NECA-mediated responses) or reversed by (i.e., Ag-mediated responses) cell permeabilization. 相似文献
36.
László E. Heszky Zsolt Jekkel Abdel-Hamid Ali 《Plant Cell, Tissue and Organ Culture》1990,21(3):217-226
Reflexed saltmarsh-grass suspension cultures produced by seed callus were frozen to the liquid nitrogen temperature. Cooling rates, cryoprotectants and holding times were taken as a function of transfer temperatures. The highest survival of cells (45%) was found at a freezing rate of 1°C min-1, without cryoprotectant treatments. The cryoprotectants (proline, dimethyl sulphoxide, glycerol), used at different concentrations and transfer temperatures, increased the survival rate. The maximum value was 78% at 12.5% (w/v) of proline with –30°C transfer temperature. Considerable improvement of viability (from 0% to 95%) among the 12.5 and 15.0% (v/v) dimethyl sulphoxide cryopreserved cells was achieved by holding them at – 20°C for 10–30 min before plunging into the liquid nitrogen. A 20 min holding time at 15.0% (v/v) glycerol level and – 30°C transfer temperature significantly enhanced the viability of the explants from 42% to 92%. Plants were successfully regenerated from cells cryopreserved with proline (w/v) and dimethyl sulfoxide (v/v) levels of 12.5 and 15.0%, respectively. 相似文献
37.
Ali Arslan Cuillermina Almazan Hans H. Zingg 《In vitro cellular & developmental biology. Animal》1995,31(2):140-148
Summary Normal and neoplastic growth of epithelial cells depends on mutual interactions between epithelial and stromal cells. As a
tool for the study of the underlying molecular mechanisms, we have developed temperature-sensitive, nontransformed cell lines
derived from rat uterine epithelium and stroma by transfecting primary cultures with a temperature-sensitive mutant of the
SV40 large T antigen. The epithelial and stromal cell lines obtained shared relevant morphological characteristics with the
primary cells from which they were derived. Immunocytochemical analysis showed that the epithelial cell lines expressed the
intermediate filament cytokeratin, whereas the stromal lines expressed the intermediate filament vimentin. Alkaline phosphatase
activity was present in all cell lines examined. All cell lines were anchorage dependent and did not form foci. One epithelial
cell line expressed oxytocin mRNA, a gene product recently shown to be highly expressed in vivo in the uterine epithelium
at term. If grown on Matrigel, this cell line formed domelike structures, a further characteristic of its differentiated phenotype.
In an attempt to reconstitute an endometrium in vitro, epithelial cells were seeded on top of a layer of stromal cells. Paraffin
cross sections showed that this in vitro system consisted of a bilayer structure. Four to five cuboidal epithelial cells were
typically anchored atop one stromal cell, forming an endometriumlike tissue. The present in vitro system should provide a
useful model for further studies on endometrial functions and epithelial/stromal cell interactions at a molecular level. 相似文献
38.
An RNA pseudoknot is an essential structural element of the internal ribosome entry site located within the hepatitis C virus 5' noncoding region. 总被引:8,自引:2,他引:6 下载免费PDF全文
Translation of the human hepatitis C virus (HCV) RNA genome occurs by a mechanism known as "internal ribosome entry." This unusual strategy of translation is employed by naturally uncapped picornaviral genomic RNAs and several cellular mRNAs. A common feature of these RNAs is a relatively long 5' noncoding region (NCR) that folds into a complex secondary structure harboring an internal ribosome entry site (IRES). Evidence derived from the use of dicistronic expression systems, combined with an extensive mutational analysis, demonstrated the presence of an IRES within the HCV 5'NCR. The results of our continued mutational analysis to map the critical structural elements of the HCV IRES has led to the identification of a pseudoknot structure upstream of the initiator AUG. The evidence presented in this study is based upon the mutational analysis of the putative pseudoknot structure. This is further substantiated by biochemical and enzymatic probing of the wild-type and mutant 5'NCR. Further, the thermodynamic calculations, based upon a modified RNAKNOT program, are consistent with the presence of a pseudoknot structure located upstream of the initiator AUG. Maintenance of this structural element is critical for internal initiation of translation. The pseudoknot structure in the 5'NCR represents a highly conserved feature of all HCV subtypes and members of the pestivirus family, including hog cholera virus and bovine viral diarrhea virus. 相似文献
39.
Summary Excavation of 18 nests ofHarpegnathos saltator from southern India revealed an unusually complex architecture for a ponerine ant. The inhabited chambers are not deep in the ground. The uppermost chamber is protected by a thick vaulted roof, on the outside of which is an intervening space serving as isolation from the surrounding soil. In large colonies, the vaulted roof is extended into a shell which encloses several superimposed chambers. Little openings, which may be encircled by moulded flanges, occur in the upper region of the shell. The inside of the chambers is partly or completely lined with strips of empty cocoons. A refuse chamber is always found deeper than the inhabited chambers; live dipteran larvae (family Milichiidae) are typically present. These elaborate nests represent a large energetic investment, and we speculate therefore that nest emigration is unlikely in this species. Consequently, colony fission may never occur, unlike other ants where gamergates reproduce. 相似文献
40.
Xu Chang Hong; Nejidat Ali; Belkin Shimshon; Boussiba Sammy 《Plant & cell physiology》1994,35(5):737-741
Partition in aqueous dextran-polyethylene glycol two-phase systemwas used to isolate the plasma membranes from the alkalophiliccyanobacterium Spirulina platensis. The upper phase containeda colorless membranes obtained in relatively short time, 34h. This fraction had a different protein profile than that ofthe thylakoid fraction obtained in the lower phase. It did notcontain cytochrome c-oxidase activity, but retained characteristicMg2+-ATPase activity that is sensitive to vanadate, stimulatedby K+, and has a pH optimum near 8.5. These data support ourassumption that the upper phase of the gradient consist of theplasma membrane of S. platensis. (Received November 25, 1993; Accepted April 12, 1994) 相似文献