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11.
Acute exacerbations of Crohn''s disease are usually treated with prednisolone or potentially more toxic immunosuppressive drugs or by surgery. In pilot studies replacing the normal diet by a protein free elemental diet also induced remission. A controlled trial was therefore conducted in which 21 patients acutely ill with exacerbations of Crohn''s disease were randomised to receive either prednisolone 0.75 mg/kg/day or an elemental diet (Vivonex) for four weeks. Assessment at four and 12 weeks showed that the patients treated with the elemental diet had improved as much as and by some criteria more than the steroid treated group. Elemental diet is a safe and effective treatment for acute Crohn''s disease. 相似文献
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Summary Growth and glucose isomerase biosynthesis in Streptomyces bambergiensis ATCC 13879 have been studied under different conditions. Some data concerning correlation between cultivation conditions and elemental analysis of the cells are also presented. 相似文献
14.
The influence of external sodium concentration on potassium (depolarizing agent)-stimulated calcium uptake and Ca+-dependent acetylcholine release by rat cerebral cortex synaptosomes has been studied. It was found that increased sodium concentration decreases both the Ca2+ uptake and the acetylcholine release, whereas a low external sodium concentration is stimulatory. 相似文献
15.
Functionally-stabilized proteins--a review 总被引:1,自引:0,他引:1
The maintenance or stabilization of protein or enzyme function is of vital importance in Biotechnology. Investigations of thermophilic organisms, studies of denaturation and the use of enzymes in organic solvents have each contributed to an understanding of protein stability. Enzymes can reliably and reproducibly be stabilized by variety of means including immobilization, use of additives, chemical modification in solution and protein engineering. Examples of each of these are discussed. With these recent advances it appears that a rational strategy for achieving a particular stabilized enzyme or protein may be within reach. 相似文献
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The plasma membrane of mammalian cells can mediate the cytotoxic and cytocidal effects of colicin E3. As little as 102 lethal units of purified colicin E3 per cell exert a pronounced cytocidal effect on human epithelial HeLa cells and as little
as 104 lethal units per cell also on line L mouse fibroblasts in tissue culture. Cells in complete monolayers are rapidly killed,
become spherical and shrink, they are detached from the support and finally autolyzed. The percentage of killed cells in both
lines is directly proportional to the multiplicity of colicin used. Theld
50 for HeLa cells is about 30 times lower than for L cells. At the multiplicity of 105 l.u., usually 100 % HeLa cells and 90 % L cells are killed in 2–3 days. Purified colicins E2 and D have no demonstrable cytological
effect on HeLa cells, although DNA synthesis in L cells appears to be partly inhibited by colicin E2. The profound effect
of colicin E3 on mammalian cells could be interpreted in a similar way as in bacteria,viz. as a specific cleavage of rRNA. 相似文献
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Citrobacter freundii was grown aerobically in a chemostat on a mineral medium witn galactose or glucose as carbon and energy sources under limitation
by carbon or nitrogen source respectively. At various specific growth rates ranging from 7 to 95% μmax the culture in steady state was analysed and growth yield, specific metabolic rate of substrate utilization, intracellular
concentration of pyruvate, ATP, ADP, AMP and energy charge were determined and plotted as functions of dilution rate. In all
four types of experiments the physiological state of cells remained practically independent of dilution rate up toD = 0.6 μmax, and at a given specific growth rate nearly independent on μmax and type of limitation. At approximatelyD = 0.6 μmax, which is close to the maximum output dilution rateD
m, the physiological state of the cells changed: growth yields decreased and intr cellular pyruvate and adenylates concentrations
increased. Consequently, in a given medium two dilution rates exist at which growth rate dx/dt is the same but the physiology
of the population is quite different. 相似文献
20.