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11.
Whole cells of Brevibacterium ammoniagenes IAM 1645 having the polyphosphate NAD-kinase were successfully immobilized in a polyacrylamide gel lattice. The immobilized cells were activated by treatment with organic solvents or detergents. The pH optimum of the immobilized cells for the production of NADP was 7.0, and divalent metal ions were required to maintain the elevated activity of polyphosphate NAD-kinase. Highly pure NADP was continuously produced in high yield by the immobilized cell column. The half-life of this column was about eight days. 相似文献
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T Miyoshi G Ooki M Murata H Hayakawa K Tomita M Imai M Suzuki 《Biochemical and biophysical research communications》1999,265(1):13-17
We have cloned a cDNA inducing a cation-permeable current (mNSC1) from pancreatic beta-cells, which shows niflumate-sensitive current in Xenopus oocytes. To elucidate the expression in mammalian cells, mNSC1 was expressed in CHO cells. The reversal potential by mNSC1 was shifted toward positive which was significantly reversed by flufenamic acid. Single-channel analysis showed a characteristic of a Ca-activated nonselective cation channel. Therefore, we may conclude that mNSC1 expresses a fenamates-sensitive cation channel, inducing membrane depolarization in a mammalian cell. 相似文献
14.
Toshihiko Sudo Xiaoxian Zhao Yoko Wakamatsu Miki Shibahara Nobuhiko Nomura Tadaatsu Nakahara Akemi Suzuki Yoshiro Kobayashi Chunyuan Jin Takehide Murata Kazunari K. Yokoyama 《Cytotechnology》2000,33(1-3):259-264
Four analogs of succinoyl trehalose lipid-3 (STL-3)with saturated even-number or odd-number carbonchains, and unsaturated or halogenated fatty acidswere examined for their ability to inhibit the growthand induce the differentiation of HL-60 humanpromyelocytic leukemia cells. The optimalconcentration of STL-3 at which such activities wererecognized was closed to the critical micelleconcentration of STL-3. Analog of STL-3 witheven-number or odd-number carbon chain and unsaturatedfatty acids strongly inhibited growth and induced thedifferentiation of HL-60 cells, as evaluated in termsof nitroblue tetrazilium-reducing activity and theappearance of the CD36 antigen. An analog of STL-3with halogenated fatty acids significantly inhibitedproliferation but only induced the differentiation ofHL-60 cells. Our results indicate that the effects ofSTL-3 and its analogs on HL-60 cells depend on thestructure of the hydrophobic moiety of STL-3.These authors contributed equally to this work 相似文献
15.
W Darmanto M Inouye S Hayasaka Y Takagishi M Ogawa K Mikoshiba Y Murata 《Biological Sciences in Space》1998,12(3):254-255
The major histogenetic events of the rat cerebellum take place in the early postnatal days. During this period, precursors of microneurons, such as granule cells, form the external granular layer (EGL), extend over the surface of the primordial cerebellum, and actively proliferate. Postmitotic granule cells leave the EOL and migrate to the internal granular layer (IGL). On the other hand, guided by radial glial fibers, immature Purkinje cells migrate from the ventricular zone of the fourth ventricle and settle in the Purkinje cell plate with thickness of several cells. Various cell adhesion molecules are involved in the interaction between the migratory immature Purkinje cells and processes of the radial glia as the basis for contact guidance. The second process is the formation of immature Purkinje cells to the monolayer. This process takes place at the first week after birth of the rat and cell adhesion molecules such as neural cell adhesion molecule (NCAM), fibronectin, tenascin and Reelin are also suggested to play an important role for the cell patterning. When rat fetuses are exposed to X-radiation in the last gestation period, abnormal foliation of the cerebellum develops with ectopic Purkinje cells. The molecular mechanism that contributes to abnormal migration of Purkinje cells and foliar malformation induced by X-irradiation in the cerebellum are not yet clear. This study was undertaken to elucidate the mechanisms of ectopic Purkinje cell formation by examining the expression of cell adhesion molecules. 相似文献
16.
Total starch, amylose content and amylose-included lipid phosphorus and lysophosphatidylcholine (LPC) were measured in normal Glacier (G) and Hi Amylose Glacier (HA) barley varieties during germination. From days three to six, alkaline and acidic lysophospholipase (LPL) activities in the starchy endosperm were measured and the distribution of these activities between a soluble and particulate form determined. During germination the amylose content of the starches increases as the total starch levels decline. The starch-bound LPC and lipid phosphorus disappear at the same rate between days three and six in both barley varieties, indicating no discrimination among the different lipid-included amylose population for degradation. However, both lipid phosphorus and LPC disappear more rapidly in the G than in the HA variety. This is presumably due to the slightly larger content of LPC per mg amylose of the G than of the HA variety, equivalent to 134 and 150 anhydroglucose residues per lipid molecule in G and HA, respectively. There is no increase in starch-bound lipid phosphorus or LPC expressed as nmol of phosphorus or LPC per mg amylose as amylose content declines, indicating no selective resistance of lipid-included amylose to degradation. The alkaline and acidic LPC activities in each variety increase 2–4-fold between days four and five. In both varieties ca 30% of the acidic LPL and ca 50–60% of the alkaline LPL is particulate from days three to six. No correlation can be made between the content of amylose or amylose-included lipid and particulate LPL activity. However, the possibility that particulate LPL activity is associated with specific populations of residual amylose-included lipid molecules cannot be excluded. 相似文献
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Sakano S Hasegawa Y Murata Y Ito T Genda E Iwata H Ishiguro N Seo H 《Biochemical and biophysical research communications》2002,293(2):680-685
Basic fibroblast growth factor (bFGF) is reported to stimulate repair of fracture and bony defects in in vivo animal studies. However, most studies performed in vitro demonstrate inhibitory effect of bFGF on cartilage and bone differentiation. To understand the discrepancy observed in in vivo and in vitro studies, we evaluated the effect of bFGF on chondro-osteogenesis initiated by bone matrix powder (MP). MP was implanted in the murine hamstring muscles with or without administration of bFGF. Injection of 1 microg of bFGF markedly reduced the size of heterotopic bone induced by MP, as detected by X-ray. Injection of 10 microg of bFGF completely inhibited ossification and only fibrous tissues were observed at the site of MP implantation. The expressions of alkaline phosphatase and osteocalcin mRNAs, markers for bone differentiation, were completely suppressed by 10 microg of bFGF. These results demonstrate the inhibitory effect of bFGF on endochondral ossification in vivo, implicating a precaution for its use in musculo-skeletal disorders. 相似文献
19.
Satoshi Takeo Reiko Tanonaka Kouichi Tanonaka Keiko Miyake Hideto Hisayama Norifumi Ueda Keiko Kawakami Hiromi Tsumura Shuichi Katsushika Yuzo Taniguchi 《Molecular and cellular biochemistry》1991,107(2):169-183
The present study was designed to induce massive accumulation of calcium in the myocardium and to evaluate the effect of calcium overload on myocardial contractile function and biochemical activity of cardiac subcellular membranes. Rats were treated with an oral administration of 500,000 units/kg of vitamin D3 for 3 consecutive days, and their hearts were sampled on the 5th day for biochemical analysis. On the 4th and 5th days, heart rate, mean aortic pressure, left ventricular systolic pressure and left ventricular dP/dt were significantly lowered in vitamin D3-treated rats, demonstrating the existence of appreciable myocardial contractile dysfunction. Marked increases in the myocardial calcium (67-fold increase) and mitochondrial calcium contents (24-fold increase) were observed by hypervitaminosis D3. Mitochondrial oxidative phosphorylation and ATPase activity were significantly reduced by this treatment. A decline in sarcolemmal Na+, K+-ATPase activity was also observed, while relatively minor or insignificant changes in calcium uptake and ATPase activities of sarcoplasmic reticulum were detectable. Electron microscopic examination revealed calcium deposits in the mitochondria after vitamin D3 treatment. The results suggest that hypervitaminosis D3 produces massive accumulation of calcium in the myocardium, particularly in the cardiac mitochondrial membrane, which may induce an impairment in the mitochondrial function and eventually may lead to a failure in the cardiac contractile function. 相似文献
20.
Akira C. Saito Toshihiko Ogura Kei Fujiwara Satoshi Murata Shin-ichiro M. Nomura 《PloS one》2014,9(9)
Here, we report a method for introducing large objects of up to a micrometer in diameter into cultured mammalian cells by electrofusion of giant unilamellar vesicles. We prepared GUVs containing various artificial objects using a water-in-oil (w/o) emulsion centrifugation method. GUVs and dispersed HeLa cells were exposed to an alternating current (AC) field to induce a linear cell–GUV alignment, and then a direct current (DC) pulse was applied to facilitate transient electrofusion. With uniformly sized fluorescent beads as size indexes, we successfully and efficiently introduced beads of 1 µm in diameter into living cells along with a plasmid mammalian expression vector. Our electrofusion did not affect cell viability. After the electrofusion, cells proliferated normally until confluence was reached, and the introduced fluorescent beads were inherited during cell division. Analysis by both confocal microscopy and flow cytometry supported these findings. As an alternative approach, we also introduced a designed nanostructure (DNA origami) into live cells. The results we report here represent a milestone for designing artificial symbiosis of functionally active objects (such as micro-machines) in living cells. Moreover, our technique can be used for drug delivery, tissue engineering, and cell manipulation. 相似文献