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61.
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Mina Mina William B. Upholt Edward J. Kollar 《Differentiation; research in biological diversity》1991,48(1):9-16
We have examined the in vitro stage-related chondrogenic potential of avian mandibular ectomesenchymal cells using micromass cultures. Our results indicate that mandibular ectomesenchymal cells as early as stage 16, soon after the formation of the mandibular arches and well before the initiation of in vivo chondrogenesis, have chondrogenic potential which is expressed in micromass culture. There is an increase in the total area of the cultures occupied by cartilage when cells from increasing stages of development are used. The nodular pattern of chondrogenesis in these cultures indicates that mandibular ectomesenchymal cells are a heterogenous population from the time of mandibular arch formation. In addition, we studied the temporal expression of the genes for extracellular matrix proteins during in vitro chondrogenesis and correlated the morphological changes with the pattern of gene expression. Low levels of type II collagen mRNA are present in the cultures prior to detection of any stainable cartilage matrix and increase 5 fold just before the onset of chondrogenesis in vitro. On the other hand mRNA for cartilage proteoglycan core protein was not detected until the second day of culture when stainable cartilage matrix was present and progressively increased thereafter. Messenger RNA for type I collagen was present at the time of initiation of cultures and continuously increased during the culture period. Our experiments also indicated that embryonic epithelia can inhibit the in vitro chondrogenesis of mandibular ectomesenchymal cells and that the inhibitory effect of embryonic epithelia is independent of its age and site of origin. 相似文献
63.
Mina E. Holm Juul John M. Dornish Niels O. Juul Erik O. Pettersen Reidar Oftebro 《Molecular and cellular biochemistry》1990,96(2):117-126
Summary Accumulation of tubulin as compared with the accumulation of total cellular protein in human NHIK 3025 cells treated with the sulfone 2-(2-thenyl)sulfonyl-5-bromopyrimidine (NY 4137) and the sulfoxide 2-(2thenyl)sulfinyl-5-bromopyrimidine (NY 4138), two mitotic inhibitors, were investigated by two-parametric flow cytometry. Following a 4 h treatment with NY 4137 tubulin accumulation is inhibited while total protein continues to accumulate. After treatment for 4h with NY 4138 the accumulation of total protein is approximately constant, while the accumulation of tubulin is reduced although not to the same degree as that found for NY 4137-treated cells. In addition, the percentage tubulin SH-groups (6.89 ± 0.14) remaining after treatment of purified rat brain tubulin with NY 4137 or NY 4138 was determined. Treatment with 0.0125 mM NY 4137 reduced the number of tubulin SH-groups detectable with dithiobis benzoate or from 6.89 ± 0.14 before treatment to about 4 after treatment. However, practically all SH-groups of tubulin remain detectable following treatment with the same concentration of NY 4138. From the results described in this report we infer that NY 4137 binds to tubulin SH-groups and that inhibition of tubulin accumulation follows as a secondary effect. 相似文献
64.
Daisuke Sato Takuya Kisen Mina Kumagai Kiminori Ohta 《Bioorganic & medicinal chemistry》2018,26(2):536-542
Xanthine oxidase (XO) is an enzyme that contains molybdenum at the active site and catalyzes the oxidation of purine bases to uric acid. Even though XO inhibitors are widely used for the treatment of hyperuricemia and gout, only very few such compounds are clinically used as drugs for the treatment of these diseases. Given the unique physicochemical properties of tropolone, i.e., its chelating effect and the pKa value that is similar to that of carboxylic acid, we have synthesized 22 5-arylazotropolone derivatives as potential XO inhibitors. In vitro enzyme-inhibitory assays for XO revealed that 3-nitro derivative 1j showed the most potent XO inhibitory activity, which is by one order of magnitude more potent than allopurinol. An enzyme-kinetic study revealed that 1j inhibited the production of uric acid by XO both competitively and non-competitively. A docking-simulation study of 1j with XO suggested that the carbonyl and hydroxyl groups of the tropolone ring interact with the hydroxy group that acts as a ligand for molybdenum and the amino acid residues around the active site of XO. 相似文献
65.
Field observations indicate that Euphorbia cotinifolia escapes attack by leaf cutting ants, which are the largest generalist herbivores of the Neotropics. We used controlled bioassays to evaluate the effect of E. cotinifolia on the foraging of the Atta cephalotes ant. In a free-choice trial, to five colonies were offered Mangifera indica leaves with a 10% aqueous E. cotinifolia extract, leaves with distilled water and untreated leaves. The carrying time and leaf area consumed were determined over a five-hour period. The effect of E. cotinifolia on the development of the symbiotic fungus on three sets of five colonies fed the leaves of this plant were compared to the controls fed M. indica and oat flakes, and the effect of the addition of extracts on the culture medium used for the symbiotic fungus isolation was evaluated. Euphorbia leaf consumption was lower than that of the other diets; its consumption as the exclusive foraging resource significantly affected the symbiotic fungus, resulting in changes in colour and texture and an 83.57% decrease in volume that occasionally caused 100% mortality. Although the aqueous extract of E. cotinifolia is not a phagodeterrent for foraging workers, it is evident that E. cotinifolia is not a preferred resource for A. cephalotes due to the negative effect on the growth and viability of the symbiotic fungus. 相似文献
66.
The Therapeutic Potential of PI3K/Akt/mTOR Inhibitors in Breast Cancer: Rational and Progress 下载免费PDF全文
Afsane Bahrami Majid Khazaei Soodabeh Shahidsales Seyed Mahdi Hassanian Malihe Hasanzadeh Mina Maftouh Gordon A. Ferns Amir Avan 《Journal of cellular biochemistry》2018,119(1):213-222
Breast cancer (BC) is the most commonly diagnosed cancer in women. The PI3K/AKT/mTOR pathway is among the most frequently dysregulated pathways in patients with BC. The activation of this pathway is associated with increased cell growth and clinical outcome, and its overexpression is associated with a poor prognosis. It has been proposed that it may be of importance as a potential therapeutic target in the treatment of BC. The aim of current review is to provide an overview of the potential utility of PI3K/Akt/mTOR inhibitors in patients with BC, with particular emphasis on recent preclinical and clinical studies. J. Cell. Biochem. 119: 213–222, 2018. © 2017 Wiley Periodicals, Inc. 相似文献
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68.
Observations on reproduction of the Lake Tana barbs 总被引:2,自引:0,他引:2
Yu. Yu . Dgebuadze‡ M. V. Mina † S. S. Alekseyev † A. S. Golubtsov 《Journal of fish biology》1999,54(2):417-423
During the rainy season (September–November 1994), in tributaries of Lake Tana (Ethiopia), the Gumara, Gelda and Negashu, barbs of diVerent morphotypes were ready to spawn, running and spent. The most numerous were barbs similar to Barbus intermedius common in many rivers of the Ethiopian Highlands. They were also found spawning in the Gumara and Gelda Rivers in the dry season (February 1996, 1997). There were no evident diVerences in time and place of spawning of barbs representing diVerent morphotypes. Only zurki, bigmouth mini-eye and bighead were not found in the rivers. Spatial and temporal segregation may contribute to reproductive isolation of morphotypes spawning in rivers, but if reproductive isolation exists the main role must be played by diVerences in mating behaviour. Morphotypes of the Lake Tana barbs have diVerent migration patterns. Barbs similar to the riverine B. intermedius may spend their lives in rivers or in the lake, moving to and fro. Barbs of acute, bigmouth big-eye and, perhaps, other morphotypes migrate downstream as alevins or fry, stay in the lake for several years and migrate back into rivers for spawning after reaching maturity. 相似文献
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