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101.
Fascin,an actin-bundling protein,modulates colonic epithelial cell invasiveness and differentiation in vitro 总被引:18,自引:0,他引:18
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Jawhari AU Buda A Jenkins M Shehzad K Sarraf C Noda M Farthing MJ Pignatelli M Adams JC 《The American journal of pathology》2003,162(1):69-80
In epithelial tissue, cell-matrix and cell-cell adhesive interactions have important roles in the normal organization and stabilization of the cell layer. The malignant conversion of epithelial cells involves alterations in the expression and function of these adhesion systems that enable a switch to a migratory phenotype in tumor invasion and metastasis. Fascin is an actin-crosslinking protein that is found in the core actin bundles of cell-surface spikes and projections that are implicated in cell motility. We demonstrate that fascin is not detectable in normal colonic epithelium, but is dramatically up-regulated in colorectal adenocarcinoma. To test the hypothesis that fascin could participate in tumor invasive behavior, we developed a cell culture model to examine the effect of fascin expression on the adhesive interactions, invasiveness, and differentiation of colonic epithelial cells. We report marked effects on the organization of cell-surface protrusions, actin cytoskeleton, and focal adhesions in the absence of alterations in the protein levels of the major components of these structures. These effects correlate with alterations in cell movements on two-dimensional matrix, and increased invasiveness in three-dimensional matrix. The cells also show increased proliferation and decreased capacity for normal glandular differentiation in collagen gels. We propose that up-regulation of fascin, by promoting the formation of protrusive, actin-based, cell-motility structures, could be a significant component in the acquisition of invasive phenotype in colonic carcinoma. 相似文献
102.
Eishun Tsuchida Masao Kaneko Hiroyuki Nishide 《Macromolecular chemistry and physics.》1972,151(1):221-234
It was found that the oxidative polymerization of 2.6-xylenol with a copper-amine complex proceeds via a mechanism similar to that of a MICHAELIS-MENTEN-type reaction, the steady state being maintained during the polymerization; the kinetics were studied. The LINEWEAVER-BURK plots showed linear relationships, supporting this mechanism. From the comparison of the kinetic constants it was concluded that oxygen not only takes part in the recycling step of the catalyst, but also promotes the catalytic action of the cuprous complex by being coordinated to the intermediate complex. K1 values (the reciprocal of the MICHAELIS constant, Km) vary with the amine-ligand species, but the reaction-rate constants (k2) do not change, regardless of the ligands used. According to the kinetic formula, K1 is proportional to the product of the formation constant of the complex between the copper-amine catalyst and the monomer (K′1) by the rate constant of electron transfer (ke). It is because of the K′1 values that the apparent polymerization rate varies with the amine ligands in the region of relatively low monomer concentrations. It was found that, as the ligand ratio ([pyridine]/[Cu]) increases, i.e., as the selectivity for C? O coupling increases, the K1 values become larger. The mechanism for the coupling selectivity is discussed in relation to the K1 values. 相似文献
103.
Shin Kobayashi Hiraku Uemura Takashi Kohda Toshiro Nagai Yasutsugu Chinen Kenji Naritomi Ei‐ichi Kinoshita Hirofumi Ohashi Kiyoshi Imaizumi Masato Tsukahara Yoshitsugu Sugio Hidefumi Tonoki Tatsuya Kishino Toshiaki Tanaka Masao Yamada Osamu Tsutsumi Norio Niikawa Tomoko Kaneko‐Ishino Fumitoshi Ishino 《American journal of medical genetics. Part A》2001,104(3):225-231
Silver‐Russell syndrome (SRS) is characterized by prenatal and postnatal growth retardation with morphologic anomalies. Maternal uniparental disomy 7 has been reported in some SRS patients. PEG1/MEST is an imprinted gene on chromosome 7q32 that is expressed only from the paternal allele and is a candidate gene for SRS. To clarify its biological function and role in SRS, we screened PEG1/MEST abnormalities in 15 SRS patients from various standpoints. In the lymphocytes of SRS patients, no aberrant expression patterns of two splice variants (α and β) of PEG1/MEST were detected when they were compared with normal samples. Direct sequence analysis failed to detect any mutations in the PEG1/MEST α coding region, and there were no significant mutations in the 5′‐flanking upstream region containing the predicted promoter and the highly conserved human/mouse genomic region. Differential methylation patterns of the CpG island for PEG1/MEST α were normally maintained and resulted in the same pattern as in the normal control, suggesting that there was no loss of imprinting. These findings suggest that PEG1/MEST can be excluded as a major determinant of SRS. © 2001 Wiley‐Liss, Inc. 相似文献
104.
Yukie Niwa Tsuyoshi Sakane Masao Shingu M. Mitsuo Yokoyama 《Journal of clinical immunology》1983,3(3):228-240
Neutrophils from the synovial fluid (SFN) of 10 patients with active rheumatoid arthritis (RA) were investigated to determine the generation of oxygen intermediates (OI) (O2-, H2O2, OH .), chemiluminescence, and lysosomal enzymes (lysozyme and beta-glucuronidase). Lymphocytes from healthy individuals were cocultured at 37 degrees C for 17 hr with SFN from the patients and the number of OKT4+, OKT8+, and OKT3+ cells and the response to mitogens were determined. A markedly increased OI and slightly elevated lysosomal enzyme levels were observed in SFN from patients. Coculture of lymphocytes with SFN resulted in a decreased number of OKT4+ and OKT8+ cells and a greatly reduced response to Con A and mildly diminished response to PHA, while OKT3+ cells were not affected. The simultaneous addition of superoxide dismutase and catalase restored the impairment of monoclonal antibody reaction and lymphocyte responsiveness almost to control levels. It is suggested that the disturbed immunoreactivity of synovial fluid lymphocytes from RA patients may be due to increased OI generated by stimulated neutrophils. 相似文献
105.
Identity of hemolysins produced by Vibrio cholerae non-O1 and V. cholerae O1, biotype El Tor. 总被引:8,自引:11,他引:8
K Yamamoto Y Ichinose N Nakasone M Tanabe M Nagahama J Sakurai M Iwanaga 《Infection and immunity》1986,51(3):927-931
Hemolysins purified from non-O1 Vibrio cholerae (non-O1 hemolysin) and a Vibrio cholerae O1, biotype El Tor (El Tor hemolysin) were investigated for their homology. The hemolysins were isolated from the culture supernatant fluids by ammonium sulfate precipitation and gel filtration on Sephadex G-100 columns. The purified hemolysins gave single bands with an identical mobility on conventional polyacrylamide gel disc electrophoresis. The molecular weights of the non-O1 and El Tor hemolysins were estimated to be about 60,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the amino acid compositions of the hemolysins were very similar. The specific activities of the hemolysins were identical, and both hemolysins were neutralized to the same extent with antisera against the homologous and heterologous hemolysins. Ouchterlony double immunodiffusion tests with both hemolysins and antihemolysin serum gave a common (fused) precipitin line. These data indicate that the non-O1 hemolysin is biologically, physicochemically, and immunologically indistinguishable from the El Tor hemolysin. 相似文献
106.
Photodegradation behavior for copolymers of styrene (St), α-methyl styrene (α-MSt) and methyl methacrylate (MMA) with methyl vinyl ketone (MVK) and phenyl vinyl ketone (PVK) in the presence of air was investigated in the solid state and in solution. Photolysis of St/MVK and St/PVK copolymers proceeded smoothly and an increase of the ketone in the copolymer resulted in an increase of the rate of degradation. Generally, the rate of degradation is faster in St/PVK copolymers than in St/MVK copolymers. It is likely that the degradation of the copolymers takes place mainly through NORRISH type II reaction. It was found that the photolysis of α-MSt/PVK copolymers was retarded considerably as compared with St/PVK copolymers. An unexpected behavior was observed in the case of MMA/MVK or MMA/PVK copolymers. These copolymers were expected to degrade with slow rates; they degraded, however, rapidly. Some experiments were done to explain this phenomenon. 相似文献
107.
Yoshiharu Doi Masao Kunioka Akira Tamaki Yoshiyuki Nakamura Kazuo Soga 《Macromolecular chemistry and physics.》1988,189(5):1077-1086
Copolyesters of 3-hydroxybutyric acid (HB) and 3-hydroxyvaleric acid (HV), P(HB-co-HV), were isolated from Alcaligenes eutrophus and characterized by solution NMR, solid-state 13C CP/MAS NMR, and differential scanning calorimetry. The 13C CP/MAS NMR analysis was compatible with that of a random copolyester of oxy-(1-methyl-3-oxotrimethylene) ( B ) and oxy-(1-ethyl-3-oxotrimethylene) ( V ) units which adopts a regular conformation of a 21 -helix in the solid state throughout a wide range of compositions varying from 0 to 90 mol-% V units. The chain dynamics of P(HB-co-HV) in chloroform was studied by analysis of the 13C and 1H NMR spectra. The carbon-13 spin-lattice relaxation times (T1) and nuclear Overhauser enhancements (NOE) indicated that the copolyester molecules in chloroform are not rigid but rather flexible. The conformational preferences of the copolyester molecules were determined by analysis of the 1H NMR spectra. 相似文献
108.
Yoshihide Takaki Masao Kishikawa Ichiro Serine Issei Nishimori Mitsuro Hieata Hideo Namiki 《Pathology international》1983,33(4):823-829
Malignant fibrous histiocytoma (MFH) has become one of the most common malignancies occurring in soft tissue. To our knowledge, the present case is the first of MFH occurring in the endometrium. The uterus removed from a 47-year-old woman demonstrated a large multinodular endometrial lesion with gross invasive foci in the myometrium and the left oviduct. Microscopically, the endometrial tumor and the invasive lesions were composed of dense sheets of markedly pleomorphic cells consisting of fibroblast-like cells, histiocyte-like cells, foamy histiocytes, benign appearing multinucleated giant cells resembling either osteoclasts or Touton giant cells, and bizarre tumor giant cells. Some of the tumor cells showed phagocytic activities. The tumor cells were oriented in a random or haphazard fashion and classical storiform and fascicular patterns were not observed. The tumor was diagnosed as MFH consisting exclusively of so-called pleomorphic pattern. The patient is alive without evidence of disease, months following total hysterectomy and bilateral salpingo-oophorectomy. 相似文献
109.
Hoshina M Shibuya H Kubo HD Miura M Ohashi I Yoshimura R Oota S 《Medical physics》2004,31(7):2068-2074
A new characterization of depth-ionization parameters for electron beams is empirically deduced from our data analysis based on the divided difference method (the DD method), which employs the numerical differential of an ionization curve. The important feature of the present method is that it does not necessarily require normalized percent depth-ionization (NPDI) data. The depth of 50% of maximum ionization, I50, which is an important parameter for electron beam dosimetry, can be deduced from the analysis of an unnormalized (or partial) depth-ionization (UDI) curve obtained over a short interval of depth. The values of I50 determined by the DD method are in agreement to within 0.1 mm for energies of 4, 6, and 9 MeV, compared with the ones determined by the TG-51 protocol method (or the conventional method), and the difference was 0.9 mm for 12 and 15 MeV. The dose at the reference depth, dref, calculated from I50 by the DD method, is found to be in agreement with TG-51 to within 0.1%. The field size dependence of the DD method using UDI data was studied for three field sizes: 6 x 6, 10 x 10, and 20 x 20 cm2. For all energies, the discrepancies of I50 as determined by both methods were 0.9 mm on average for the 6 x 6 cm2 fields and 0.6 mm for the other two field sizes. This dependence was remarkable for 6 x 6 cm2 fields for 12 and 15 MeV, and the discrepancies shown by the DD method were 1.2 mm for 12 MeV and 1.8 mm for 15 MeV, respectively. Since the reference field size in clinical dosimetry is usually 10 x 10 cm2, this dependence will not affect clinical dosimetry. The DD method could be an alternative option for checking beam quality in dose calibration. 相似文献