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991.
Hiroshi Taguchi Shiro Koyama Yoshihide Shimabayashi Kazuo Iwai 《Analytical biochemistry》1983,131(1):194-197
A new fluorometric assay method for quinolinic acid is introduced in this study. Quinolinic acid-hydrazine complex, a stable fluorescent compound, is formed after heating quinolinic acid with hydrazine at 215–220°C for 2 min. Fluorescence excitation and emission maxima of the complex are at 285 and 380 nm, respectively. This assay method is rapid and rather sensitive. It takes about 30 min to ascertain the amount of quinolinic acid as low as 50 ng. Specificity of this method is high among biological compounds. An ultrasensitive assay method for uinolinic acid (as low as 20 pg) with diphenylhydrazine instead of hydrazine is also found. After separating the quinolinic acid-diphenylhydrazine complex from residual diphenylhydrazine, this ultrasensitive assay method may be practically applicable. 相似文献
992.
Kazuo Yoshizaki Yoshiteru Seo Hiroyasu Nishikawa 《Biochimica et Biophysica Acta (BBA)/General Subjects》1981,678(2):283-291
High-resolution proton magnetic resonance spectra of intact muscles of frog and rat were obtained with selective saturation of the water signal. The spectra consisted of the superposition of a broad component and a high-resolution portion. The line width of the former was about 5 ppm and is assumed to originate from the protons of the macromolecules in muscle. The high-resolution portion showed well-resolved signals arising from creatine phosphate, creatine, carnosine, lactate and lipids. It is suggested that this technique could be used to monitor the intracellular pH by measuring the chemical shift of carnosine and the lipid consumption due to muscular contraction. When the spectrum of 31P-NMR is prepared simultaneously, the ratio of creatine phosphate to total creatine can also be determined. 相似文献
993.
Kazuo Sugamura Hideki Tozawa Morio Homma Nakao Ishida 《Microbiology and immunology》1974,18(5):349-355
Infection of a subline of L cells adapted to grow in suspension (Ls) with Fushimi strain of HVJ (HVJ-F) resulted in a virus carrier state. Ls cells, when cultured in monolayer, showed morphological changes following infection of HVJ-F and were detached from the glass wall. However, when the detached cells were transferred to a new environment of suspension culture within 5 days after infection, the carrier state was again established. HVJ-F caused only lethal infection in L cells maintained exclusively in monolayer (Lm). On the other hand, both Ls and Lm, irrespective of their culture conditions, were lethally infected by Nagoya 1–60 strain of HVJ. The overall results showed that culture condition as well as the kind of host cells or virus strains is an important factor regulating the establishment and maintenance of the virus carrier state. 相似文献
994.
Noriaki Endo Yumiko Takeda Kazuo Kishida Yoshinori Kato Masahiko Saito Naoji Umemoto Takeshi Hara 《Cancer immunology, immunotherapy : CII》1987,25(1):1-6
Summary In studies on antitumor antibody-cytotoxic drug conjugates as potential tumor-selective cytotoxic agents, methotrexate (MTX) was conjugated via its active ester derivative with a murine monoclonal antibody (aMM46) to a mouse mammary tumor antigen (MM antigen) on syngeneic, ascitic C3H/He mouse mammary tumor MM46 cells. The conjugate retained full antibody activity, as assayed by complement-dependent cytolysis. The target-selective cytotoxicity of aMM46-MTX was verified by the observations that this conjugate showed greater cytotoxicity than the corresponding normal mouse immunoglobulin (nIg) conjugate to MM46 cells, neither aMM46 nor nIg being cytotoxic, and that it showed less cytotoxicity to MM antigen negative mouse mammary tumor MM48 cells than to MM46 cells, its cytotoxicity to MM48 cells being similar to that of the nIg conjugate. From the results of assays of cell binding and uptake of 131I-labeled aMM46 and aMM46-3H-MTX, aMM46 and aMM46-MTX were internalized after their binding to MM46 cell surface antigen. Leupeptin, an inhibitor of the lysosomal endopeptidase cathepsin, decreased the cytotoxicity of aMM46-MTX, supporting the involvement of lysosomal degradation of the conjugate in its action. 相似文献
995.
Rufous turtle dove, Streptopelia orientalis, coming to the soybean field entered it from the outer part to eat soybean cotyledons. As a result, the injured plants extended from the outer to inner parts in the field. A model expressing these behaviours was constructed here, by assuming that the amount of food birds can eat in one block determines whether they stay there or move into neighbour block. As the food decrease due to exploitation of them by birds, birds enter into farther parts with the passage of time. The rate of feeding in all visiting birds (an0 where a is the rate of feeding per individual and n0 the number of birds visiting) and the rate of staying at a block, b, was estimated from the field experimental results, using the above model. The value of an0 fluctuated greatly, depending upon the season in which soybean seeds sowed. The value of b also fluctuated inversely with that of an0, suggesting the the staying rate decreases with an increase in the number of doves coming, probably because of interference among individuals. 相似文献
996.
Kazuo Suzuki 《Analytical biochemistry》1978,88(2):468-474
A simple and sensitive method for the assay of trans-cinnamic acid 4-hydroxylase by use of tritiated substrate is described. This method is based on the migration of tritium during the enzyme-catalyzed hydroxylation. The hydroxylase activity is detected in microsomes from Phaseolus mungo. The tritium method can be used practically with sensitivity similar to that of the 14C method. In view of the time and labor required the tritium method is obviously more advantageous. 相似文献
997.
998.
999.
Kuroda K Kitagawa Y Kobayashi K Tsumura H Komeda T Mori E Motoki K Kataoka S Chiba Y Jigami Y 《FEMS yeast research》2007,7(8):1307-1316
When human antibody genes were expressed in the methylotrophic yeast Ogataea minuta, the secreted antibody became partially degraded. To suppress the degradation, a vacuolar protease-deficient strain was constructed and its antibody production was evaluated. Although antibody productivity was improved in the vacuolar protease-deficient strain, the secreted antibody still became partially degraded. Peptide sequencing revealed that the cleavage occurred in the CH1 region of the heavy chain, implying that the cleavage was caused by an aspartic protease, Yps1p. To inhibit this cleavage, Yps1p-deficient strains were constructed and their antibody production was evaluated. As a result, the partial degradation of the antibody was suppressed in the O. minuta multiple-protease-deficient strains. 相似文献
1000.
Imai M Tago Y Ihara M Kawata M Yamamoto K 《Molecular genetics and genomics : MGG》2007,278(2):211-220
We have previously demonstrated that the Escherichia coli strain mutS
ΔpolA had a higher rate of transition and minus frameshift mutations than mutS or ΔpolA strains. We argued that DNA polymerase I (PolI) corrects transition mismatches. PolI, encoded by the polA gene, possesses Klenow and 5′ → 3′ exonuclease domains. In the present study, rates of mutation were found to be higher in
Klenow-defective mutS strains and 5′ → 3′ exonuclease-defective mutS strains than mutS or polA strains. The Klenow-defective or 5′ → 3′ exonuclease-defective mutS strains showed a marked increase in transition mutations. Sites of transition mutations in mutS, Klenow-defective mutS and 5′ → 3′ exonuclease-defective mutS strains are different. Thus, it is suggested that, in addition to mutS function, both the Klenow and 5′ → 3′ exonuclease domains are involved in the decrease of transition mutations. Transition
hot and warm spots in mutS
+
polA
+
strains were found to differ from those in mutS and mutS ΔpolA strains. We thus argue that all the spontaneous transition mutations in the wild-type strain do not arise from transition
mismatches left unrepaired by the MutS system or MutS PolI system. 相似文献