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61.
Both hydroxymonocarboxylic acids and dicarboxylic acids in urine were converted into their 2-nitrophenylhydrazides without lengthy and cumbersome sample workup and were separated from each other by two-step extraction with diethyl ether at different pH values. HPLC analysis of each acid group was achieved isocratically within 30 min. By the use of a visible-range detector (400 nm) the detection limits ranged from 1 to 2 pmol and from 2 to 5 pmol per injection for the hydroxymonocarboxylic acids and dicarboxylic acids, respectively. The analytical results showed good recovery and reproducibility. Analysis profiles of the two acid groups in normal and diabetic subjects could be performed with 200 microliters of urine. The present method is superior over previously published methods because of its great simplicity and its time-, cost-, and labor-saving nature. 相似文献
62.
K Minakata M Asano T Sato N Harada 《Hoppe-Seyler's Zeitschrift für physiologische Chemie》1982,363(5):493-498
A new proteinase inhibitor has recently been found in human serum or plasma which specifically inhibits cysteine proteinases such as ficin, papain, bromelain and cathepsin B. However, serum contains alpha 2-macroglobulin which also inhibits these cysteine proteinases and, consequently, interferes with the assay of the new alpha-cysteine proteinase inhibitor. Therefore, assay of the inhibitor in serum has not been established previously. In the present method, the alpha 2-macroglobulin is inactivated by preincubating the serum in methylamine solution at 55 degrees C, while the alpha-cysteine proteinase inhibitor retains its activity. The inhibitory power against cysteine proteinases is found to be due mainly to this protein in human serum. This inhibitor is also found in mammals such as cows, pigs and rats. Vitamin E deficient rats show a very high inhibitor level. Therefore, the present method will enable us to investigate the relation between diseases and the activity of the alpha-cysteine proteinase inhibitor. Also, this method is simple and inexpensive. The necessary amount of serum is only 10 microliter. 相似文献
63.
Toshio Nakatani Kazue Ozawa Motokazu Asano Minoru Ukikusa Yasuo Kamiyama Takayoshi Tobe 《Life sciences》1981,28(3):257-264
The changes in the energy substrate utilized by the remnant liver were studied in relation to the changes in the cellular energy status of 25 and 70% hepatectomized rabbits. In 25% hepatectomized rabbits, the energy charge level of the remnant liver remained unchanged, the energy substrate of which was predominantly glucose, rather than fatty acid. In contrast, in 70% hepatectomized rabbits, the energy production by the mitochondria was mainly dependent upon fatty acid oxidation at the early period after hepatectomy when the energy charge level decreased remarkably, and then upon glucose oxidation, concomitant with the restoration of the energy charge. It is suggested that the changes in the energy substrate utilized are closely related to those in the energy charge level and the mitochondrial phosphorylative activity of the remnant liver following hepatectomy. 相似文献
64.
65.
Differences between surface antigenic determinants of polar monotrichous flagella of Vibrio parahaemolyticus and of related species 总被引:2,自引:0,他引:2
Polar monotrichous flagella (M-flagella) of Vibrio parahaemolyticus have antigens in common with those of various species of Vibrio including V. cholerae and V. anguillarum, and of Beneckea, revealed by gel diffusion tests with flagelli monomers. However, antiserum against M-flagellin of V. parahaemolyticus did not agglutinate cells of V. cholerae and V. anguillarum, although it did agglutinate cells of V. parahaemolyticus. Agglutination tests after absorption of the antiserum with purified M-flagellar filaments or flagellin monomers and H-agglutination inhibition tests demonstrated that there are two different antigenic determinants in M-flagella as in lateral flagella. One is on the surface of the M-flagella (surface antigenic determinant, SA) and disappears or is buried in dissociated monomers. The other is inside the flagella (internal antigenic determinant, IA) and is exposed when the flagella are dissociated to flagellin monomers. SA of V. parahaemolyticus is different from those of V. cholerae and V. anguillarum, whereas the three species have a common IA. 相似文献
66.
Actinogelin, a regulatory protein of cell motility, enhanced gelation of actin filaments in the absence of calcium ions, only on standing still or with very low velocity gradients ( less than 0.1 s-1). The Ca2+-sensitive action of actinogelin on action filaments was dependent on a weak external force. In the presence of a micromolar level of Ca2+, actinogelin did not affect the network formation of actin filaments at all. 相似文献
67.
The preparation of cell fusion-inducing proteoliposomes from purified glycoproteins of HVJ (Sendai virus) and chemically defined lipids 总被引:1,自引:0,他引:1
Cell fusion-inducing (fusogenic) proteoliposomes of defined chemical composition were reconstituted from purified glycoproteins of hemagglutinating virus of Japan (Sendai virus) either with lipids extracted from the virus particles or with a chemically defined lipid mixture. Cell fusion reactions induced by the reconstituted system have several important characteristics similar to the virus-induced fusion reaction: fusogenic activity of the proteoliposomes depends on the presence of active fusion protein in the vesicles and, in the case of Ehrlich tumor cells, the fusion is almost completely inhibited by adding cytochalasin D to a final concentration of 4 microgram/ml. The only known difference between the original and reconstituted systems is that a greater amount of the latter is necessary for the same degree of fusogenic activity. Thus, the reconstituted system can be used as a model for the Sendai virus-induced fusion reaction. A lipid mixture (phosphatidylcholine:phosphatidylethanolamine:phosphatidylserine:sphingomyelin = 1:2:1:1, by weight, and cholesterol equimolar to the total phospholipids) similar to that of the virion was active for reconstitution, whereas a mixture containing the same composition of phospholipids but no cholesterol, and ones containing cholesterol with only a single species of phospholipid were not reconstitutively active. 相似文献
68.
Four tests for antibody to varicella-zoster (V-Z) virus were compared; these were tests of complement fixation (CF), neutralization (NT), fluorescent antibody to membrane antigen (FAMA) and immune adherence hemagglutination (IAHA). Fifty-two sera from patients with varicella and zoster and from recipients of live varicella vaccine were examined by the 4 tests. The CF test was least sensitive, but the antibody titers by the NT, FAMA and IAHA tests were roughly comparable. The IAHA test was the simplest and fastest to perform, and appeared suitable for routine serological assay to V-Z virus. The correlation between the IAHA antibody titer and susceptibility of individuals to clinical varicella was investigated retrospectively using sera obtained during 2 outbreaks of varicella in an institution for children, where all the unvaccinated children had developed varicella symptoms. Most of the 25 pre-exposure sera from unvaccinated children examined by the IAHA test had tiers of less than 1:2. In contrast, all the 23 sera from vaccinated children who did not develop varicella had detectable antibody titers of 1:2 to 1:64. These results indicate that the IAHA titer reflects the susceptibility or resistance of individuals to clinical varicella. 相似文献
69.
Relationship between Na+-dependent respiration and Na+ + K+-adenosine triphosphatase activity in the action of thyroid hormone on rat jejunal mucosa. 下载免费PDF全文
Administration of three successive doses of triiodothyronine (T3) (50 micrograms/100 g body wt), given on alternate days to thyroidectomized and euthyroid rats, stimulated oxygen consumption (QO2) and Na+ transport-dependent respiration (QO2 [5]) in the stripped jejunal mucosa, a preparation that consisted mostly of epithelial cells. The increase in QO2(t) accounted for 57% of the increment in QO2 in the transition from the hypothyroid to the euthyroid state and for 29% of the increment in the transition from the euthyroid to the hyperthyroid state. Administration of T3 to hypothyroid rats also increased the yield of epithelial cells. Injection of T3 into thyroidectomized and euthyroid rats increased the specific activity (at Vmax) of the (Na+ + K+)-dependent adenosine triphosphatase (NaK-ATPase) in jejunal crude membrane preparations. No significant change was recorded in the activity of Mg-ATPase in the same preparation. The ratio of QO2/NaK-ATPase and QO2(t)/NaK-ATPase in the various thyroid states remained constant, indicating proportionate increased in the respiratory and enzymatic indices. The effect of administration of T3 to thyroidectomized rats on the number of NaK-ATPase units (recovered in the crude membrane preparation) was estimated by: (a) Na+ + Mg++ + ATP-dependent binding of [3H]-ouabain to crude membrane fractions, and (b) the amount of the phosphorylated intermediate formed in the NaK-ATPase reaction from AT32P(gamma). Estimates were obtained of the maximal number of [3H]ouabain binding sites (Nm) and dissociation constants (Kd). Nm for [3H]ouabain and Nak-ATPase specific activity increased to about the same extent after T3 administration to thyroidectomized rats, with no change in the apparent Kd values. The amount of phosphorylated intermediate formed in jejunal crude membrane preparations also increased significantly. Thus, thyroid hormone administration may increase the number of active Na+pump sites in the plasma membrane. The apparent increase in the number of Na+ pump sites also correlated with the hormone dependent increases in QO2 and QO2(t). 相似文献
70.