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11.
Level of translatable messenger RNA coding for argininosuccinate synthetase in the liver of the patients with quantitative-type citrullinemia 总被引:2,自引:0,他引:2
Mariko Sase Keiko Kobayashi Yasushi Imamura Takeyori Saheki Kyoko Nakano Satoshi Miura Masataka Mori 《Human genetics》1985,69(2):130-134
Summary The translation activity of mRNA coding for argininosuccinate synthetase in total RNA extracted from the liver of three patients with quantitative-type citrullinemia was determined using a cell-free translation system. In two patients, the hepatic content of the enzyme was about 20% of the control value, whereas translatable mRNA level for the enzyme was similar to or slightly lower than those of control livers. In the third patient, the enzyme content was about 50% of the control value, and mRNA activity for the enzyme was low normal. These results indicate that at least in the first two patients, the decrease in the enzyme protein is due either to increased degradation of the enzyme or to decreased translation in the patient's liver. 相似文献
12.
Effects of auxin and cytokinin on cell growth and alkaloid production in cell suspension cultures of Thalictrum minus were examined in an attempt to increase the productivity of a medicinal compound, berberine. In Linsmaier and Skoog medium containing auxin such as 2,4-D (1 M), the cultured cells grew rapidly, producing little berberine. On the other hand, the berberine-producing activity was remarkably enhanced by simultaneous administration of auxin and cytokinin, although cell growth was inferior. In particular, for the combination of NAA (60 M) and 6-benzylaminopurine (10 M), the yield of berberine was as high as 20 mg/30 ml medium after 2 weeks of culture. Furthermore, most of the berberine produced by the cells was released into the liquid medium, in which an excess of berberine crystallized. The results of the present experiments are suggestive of an advantage in adopting a two-stage culture method for the production of berberine in fermentor systems.Abbreviations LS
Linsmaier and Skoog
- 2,4-D
2,4-dichlorophenoxyacetic acid
- NAA
1-naphthaleneacetic acid
- IAA
indole-3-acetic acid
- IBA
indole-3-butyric acid
- BAP
6-benzylaminopurine 相似文献
13.
Cell suspension cultures of Carica papaya were found to produce a papain-like enzyme showing an amidase activity similar to papain. Experiments suggested that the enzyme was an SH-enzyme, but an immunological test indicated the absence of papain in cultured cells. The isoelectric point (4.3) of the enzyme of cultured cells was the same as that of the leaf extract, but was different from that of papain or other amidases in the latex of the fruit. 相似文献
14.
In order to clarify whether a dietary fiber has any effect upon the intestinal absorption of sulfonylurea, changes in plasma concentration of glibenclamide were determined during a six-hour period in nine healthy volunteers who took 2.5 mg of glibenclamide together with a breakfast and 3.9 g of glucomannan in a form of konjac powder and were compared with those of the control experiment in which the same amount of the hypoglycemic agent was given without the dietary fiber. In the control, mean plasma glibenclamide level increased rapidly, reaching a peak at 60 min and decreased gradually thereafter, whereas an increase in plasma glibenclamide level was blunted in the test experiment, thus plasma concentration of glibenclamide being lower at 30, 60, 90 and 150 min compared with the corresponding value of the control (31.7 +/- 24.5 ng/ml vs 76.4 +/- 25.0 ng/ml at 30 min; 51.3 +/- 35.5 ng/ml vs 120.9 +/- 56.0 ng/ml at 60 min; 60.0 +/- 38.8 ng/ml vs 117.4 +/- 53.1 ng/ml at 90 min; 54.0 +/- 31.5 ng/ml vs 100.7 +/- 46.5 ng/ml at 150 min). Mean plasma glucose concentration was significantly lower at 30 min in the test experiment than in the control despite the lower level of plasma glibenclamide in the former. The results suggest that glucomannan may influence the intestinal absorption of glibenclamide. A dietary fiber must be prescribed in due consideration of these facts. 相似文献
15.
Cultured cells ofThalictrum flavum take up berberine exogenously added to medium against the concentration gradient. This uptake was temperature-dependent and sensitive to plasma membrane-bound ATPase inhibitors such as sodium orthovanadate and diethylstilbestrol, indicating that the process is mediated by an energy-requiring system. The time-course of pH-shift during berberine uptake suggests the participation of a berberine-proton antiport system in the berberine uptake by the cultured cells. In addition, the existence of a specific transport system was suggested by the competitive inhibition of berberine uptake by berberine analogues, coptisine and jatrorrhizine. 相似文献
16.
The ample supply of O2 proved to be of great importance for berberine production in cell suspension culture ofThalictrum minus, as the specific O2 consumption rate of berberine-producing cells was twice as high as that of non-producing cells. Furthermore, berberine yield increased with increases in the volumetric O2 transfer coefficient (KLa). Estimation of the optimum conditions of oxygen supply in suspension cultures and immobilized cells according to a known theoretical model assuming O2 uptake by cells to be a zero-order reaction was in good agreement with the experimental data. The O2 supply to immobilized cells could be improved by reducing the cell density and radius of the bead. 相似文献
17.
Construction of an ordered cosmid collection of the Escherichia coli K-12 W3110 chromosome. 总被引:23,自引:12,他引:11
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S Tabata A Higashitani M Takanami K Akiyama Y Kohara Y Nishimura A Nishimura S Yasuda Y Hirota 《Journal of bacteriology》1989,171(2):1214-1218
A cosmid library of the Escherichia coli K-12 W3110 chromosome was constructed in which clones were assigned to locations on the chromosome map by hybridization and genetic marker complementation tests. Approximately 70% of the genome was represented by this library. The identified clones can be maintained in the homologous system and would facilitate genetic studies of E. coli. 相似文献
18.
When two separated Chara internodal cells were kept in contactover a length of 14 mm or more in moist air, an action potentialof one cell could be transmitted to the other cell in about40% of cases (ephaptic transmission). The action potential ofthe former cell was sometimes eliminated transiently when anew action potential was elicited in the latter cell. The newaction potential reactivated the former cell. The conductionvelocity of the action potential was reduced from 0.30?0.11cm/s (mean?SD) to 0.15?0.05 cm/s by ephaptic transmission ofthe action potential. Substitution of an artificial pond waterfor moist air or contact over a shorter length (4 mm insteadof 14 mm or more) between the two cells reduced the couplingratio, the ratio of the change in membrane potential of onecell to that of the other cell, and no transmission was observed.After ephaptic transmission, the action potentials of the twocells were conducted at almost the same velocity along the cells.The velocity was increased to 0.68?0.06 cm/s by simultaneousconduction of the action potentials in the two adjacent cells.When the simultaneously conducted action potentials reachedthe node of one cell, at the point at which another cell madecontact, they were able very frequently to trigger a new actionpotential in the adjoining cell. (Received September 28, 1989; Accepted April 5, 1990) 相似文献
19.
Nodal cells of Chara braunii were exposed to artificial pondwater (APW) for a month or more, with removal of larger surroundingcells. The membrane resistance, resting potential, amplitudeof the action potential, and threshold voltage measured fromthe resting level were examined. Exposure to APW had markedeffects on membrane properties. (Received April 2, 0990; Accepted August 24, 1990) 相似文献
20.
A highly sensitive FIA system for chemiluminometric determination of reduced coenzyme, NADH, was developed, using immobilized NADH oxidase from Brevibacterium ammoniagenes. The enzyme catalyzed the oxidation of NADH generating hydrogen peroxide which emitted chemiluminescence when mixed with luminol and potassium ferricyanide. The immobilized enzyme reactor was a mini-column, measuring 1 or 2 mm in inner diameter and 20 mm in length, and the sample volume was only 1 microliter per assay, with a feeding speed of one sample per min and a lowest detection limit of 10 pmol NADH. A FIA system was also developed for the determination of magnesium in human serum, using an enzyme column reactor with simultaneously coimmobilized hexokinase, D-glucose-6-phosphate dehydrogenase, and NADH oxidase. The performance of the system was as satisfactory as a routine colorimetric assay, but with much higher sensitivity. 相似文献