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91.
Destabilization of Raf-1 by geldanamycin leads to disruption of the Raf-1-MEK-mitogen-activated protein kinase signalling pathway. 总被引:7,自引:0,他引:7 下载免费PDF全文
92.
The liver is a target for toxic chemicals such as cadmium (Cd). When the liver is damaged, hepatic stellate cells (HSC) are activated and transformed into myofibroblast-like cells, which are responsible for liver fibrosis. Curcuma longa has been reported to exert a hepato-protective effect under various pathological conditions. We investigated the effects of C. longa administration on HSC activation in response to Cd induced hepatotoxicity. Forty adult male albino rats were divided into: group 1 (control), group 2 (Cd treated), group 3 (C. longa treated) and group 4 (Cd and C. longa treated). After 6 weeks, liver specimens were prepared for light and electron microscopy examination of histological changes and immunohistochemical localization of alpha smooth muscle actin (αSMA) as a specific marker for activated HSC. Activated HSC with a positive αSMA immune reaction were not detected in groups 1 and 3. Large numbers of activated HSC with αSMA immune reactions were observed in group 2 in addition to Cd induced hepatotoxic changes including excess collagen deposition in thickened portal triads, interlobular septa with hepatic lobulation, inflammatory cell infiltration, a significant increase in Kupffer cells and degenerated hepatocytes. In group 4, we observed a significant decrease in HSC that expressed αSMA with amelioration of the hepatotoxic changes. C. longa administration decreased HSC activation and ameliorated hepatotoxic changes caused by Cd in adult rats. 相似文献
93.
The plant alkaloids vinblastine and colchicine are known to arrest cells in mitosis by virtue of their binding to spindle protein. These drugs are also capable of binding to microtubule protein and causing these structures to disaggregate into nonfunctional subunits (1, 2). Microtubular structures are thought to be involved in the secretory process of a number of proteins including insulin (7), collagen (4), and thyroid hormone (12). In this report we present our findings on the effects of these two drugs on the synthesis and secretion of interferon in a high producing human foreskin fibroblast strain (FS-4) (11). 相似文献
94.
95.
The effect of aeration on growth and production of extra- and intracellular lipids was studied in the yeast Rhodotorula glutinis. Oxygen concentration in the medium optimal for biomass formation did not favour the maximal lipid yield. Changes in the fatty acid composition of the both lipid types as a function of aeration are discussed. 相似文献
96.
Isolation and mapping of Escherichia coli K12 mutants defective in Tn9 transposition 总被引:2,自引:0,他引:2
T. S. Hyina E. V. Nechaeva Yu. M. Romanova G. B. Smirnov 《Molecular & general genetics : MGG》1981,181(3):384-389
Summary Five mutants (called tnm) of Escherichia coli with impaired ability for transposition of Tn9 were isolated after treatment with ethyl methanesulfonate (EMS) or N-methyl-N-nitro-N-nitrosoguanidine (NG).The map locations of the tnm mutations were deterimined by a combination of Hfr matings, F episome complementation and P1 transductional mapping. The data obtained show that the five tnm mutations are located near 91 min on the Escherichia coli linkage map and are cotransducible with the metA marker with a frequency of 3%–4%. Introduction of F plasmids containing this region complements the Tnm- phenotype for the two mutants tested i.e. tnm-1 and tnm-2 are recessive in tnm
+/tnm-merodiploids. 相似文献
97.
98.
S Shmidt L G Kuznetsova E A Romanova A Nimann T S Oretskaia N F Krynetskaia V G Metelev Z A Shabarova 《Bioorganicheskaia khimiia》1991,17(6):823-830
A synthesis of synthons which allow one to introduce 2'-deoxy-2'-fluoropyrimidine derivatives into the oligodeoxynucleotide chain by means of the standard solid phase phosphoramidite method has been developed. Oligonucleotides with 1-beta-D-arabinofuranosylcytosine were synthesized using either aC derivative with the unprotected 2'-OH group or O2,2'-anhydro-4-thiouridine. The synthesis of seven modified oligonucleotides (7 to 11 nucleotide residues) is described and their ability to form duplexes with complementary DNA have investigated as well as RNase H hydrolysis of hybrids formed by the E. coli 5S RNA and the obtained oligonucleotide probes. 相似文献
99.
N V Kostiuchenko V P Romanova S B Serebriany? V K Kibirev 《Ukrainski? biokhimicheski? zhurnal》1987,59(3):8-12
The capacity of methyl esters of arginine-containing substrates to inhibit the proteolytic activity of thrombin is studied. A relationship between the structure of peptides and their capacity to inhibit the thrombin-fibrinogen reaction is investigated. Parameters Ks, k2 and k3, which characterize individual stages of the protein process are calculated from experimentally obtained kcat, Km and I50 values. It is shown that the antithrombin activity of peptides becomes maximal only in the case when residues of hydrophobic amino acids would be simultaneously present both at the positions of P2 and P3 of oligopeptides. 相似文献
100.
Four male mice (1-month-old) of BALB strain have been studied. Three types of cells participate in formation of cellular lining of the terminal branchioles: ciliated, Clara cells and villose cells which are included in the neuroepithelial bodies composition. Clara cells are numerous and they are similar in their ultrastructural organization, they contain a great number of polymorphous secretory granules, single mitochondria and a poorly developed endoplasmic reticulum. A comparatively large number of pores of Khone are revealed: there are 4-8 pores per one alveole, and one pore is situated on 197.4 mcm2 of the alveolar surface. Alveolocytes of the second type of make the main actively secreting cell population of the alveolar passages and alveoles. Simultaneously, at the state of secretion there are 76% of the cells. The secretion of alveolar surfactant is realized by means of merocrine exocytosis. Relative volumetric fraction of mitochondria in alveolocytes of the II type comprises 12% and that of "cytophospholiposomes" (osmiophilic laminar bodies)--11%. 相似文献