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31.
Masao Kawai Kenji Yoshiba Shigeru Ando Shigeru Azuma 《Primates; journal of primatology》1968,9(1-2):1-12
The social behavior pattern of a solitary male at Koshima was studied by means of radio-telemetry. The relationship between the solitary males and the troop was estimated from radio-tracking data of the former's location and movement, and by direct observation of the latter at each corresponding hour.For most of day, the solitary male stayed within a distance of about 20 to 150 m from the central part of the troop, occasionally approaching it. His movement also was synchronized with that of the troop. For two nights, the solitary male slept at places which were about 200 m from the sleeping sites of the troop and faced them across the beach. The relationship between the solitary male and the troop did not seem to be strongly antagonistic.It can be assumed that the solitary male was moving according to certain pre-determined relationships or social contacts with the troop. The example of this solitary male shows the existence of the solitary male that follows and maintains contact with the troop, even outside the copulatory season.This study was sponsored by Scientific Research Grant No. 91620 of the Ministry of Education to the Japan Monkey Centre. 相似文献
32.
Masahiro Miyazaki Yasunori Suzuki Munehiro Oda Akira Kawai Liyan Bai Jiro Sato 《In vitro cellular & developmental biology. Plant》1989,25(9):839-848
Summary For serum-free primary culture of adult rat hepatocytes, a synthetic medium DM-160 and rat-tail collagen were selected for
the basal medium and for the culture substratum, respectively. Barbiturates, such as phenobarbital and 1-ethyl-5-isobutylbarbiturate,
efficiently supported survival of hepatocytes and maintained their morphologic features at lower concentrations under the
serum-free conditions than under the serum-supplemented conditions. However, the hepatocyte survival rates under the serum-free
conditions were lower than those under the serum-supplemented conditions in the presence or absence of barbiturates. Supplementation
of the basal medium with a combination of five groups of factors (5Fs), such as eight amino acids (Ala, Arg, Gly, Ile, Met,
Phe, Pro, and Trp), two unsaturated fatty acids (linoleate and oleate), a protease inhibitor (aprotinin), three vitamins (A,
C, and E), and five trace elements (Mn, Fe, Cu, Zn, and Se), improved the hepatocyte survival under the serum-free conditions
in the presence or absence of barbiturates. In other words, the serum could be completely substituted by the 5Fs. Hepatocyte
cultures maintained in the 5Fs-suppelemented basal medium showed excellent induction of tyrosine aminotransferase activity
in response to dexamethasone in the presence or absence of barbiturates. The efficiency of the 5Fs-supplemented basal medium
for maintaining hepatocytes was not inferior to those of other media in common use with hepatocytes, such as Williams' medium
E and Waymouth's medium MB-752/1. In conclusion, maintenance of functional hepatocytes in serum-free primary culture could
be improved by use of the new medium preparation (the 5Fs-supplemented DM-160) in the presence of barbiturates.
This work was supported by a grant no. 61771923 from the Ministry of Education, Science and Culture of Japan. 相似文献
33.
Molecular cloning and nucleotide sequence of a gene for alkaline cellulase from Bacillus sp. KSM-635 总被引:5,自引:0,他引:5
A gene for alkaline cellulase from the alkalophilic Bacillus sp. KSM-635 was cloned into the HindIII site of pBR322 and expressed in Escherichia coli HB101. Although the recombinant plasmid contained two HindIII inserts of 2.6 kb and 4.0 kb, the inserts were found to be contiguous in the Bacillus genome by hybridization analysis. Nucleotide sequences of a 2.4 kb region which was indispensable for the production of cellulase, and the flanking, 1.1 kb region, were determined. There was an open reading frame (ORF) of 2823 bp in the 3498 bp sequence determined, which encoded 941 amino acid residues. Two putative ribosome-binding sites and a sigma 43-type, promoter-like sequence were found upstream from an initiation codon in the ORF. The deduced amino-terminal sequence resembles the signal peptide of extracellular proteins. A region of amino acids, 249 to 568, of the deduced amino acid sequence of the cellulase from this organism is homologous with those of alkaline and neutral enzymes of other micro-organisms, but nine amino acid residues were found to be conserved only in the alkaline enzymes. 相似文献
34.
35.
We investigated the peroxidative effect of paraquat and active oxygens on detergent-dispersed linolenic acid in phosphate buffer (pH 7.5) from the malondialdehyde (MDA) level. Our complete system and further inclusion of catalase were effective in stimulating MDA formation. On the other hand, xanthine oxidase (XOD) or paraquat omission, superoxide dismutase (SOD) inclusion or anaerobic incubation inhibited the formation of MDA. Ferrous ion was weakly associated with phosphate of the buffer, forming a complex, and the release of ferrous ion from the complex intensified the MDA levels with the complete and catalase inclusion systems. The electron paramagnetic resonance (EPR) spectra using 5,5-dimethyl-1-pyrroline N-oxide (DMPO) showed that superoxide, produced immediately after the addition of XOD, played a crucial role. We could obtain a DMPO-OOH signal at the starting stage whenever MDA stimulation was observed. The omission of paraquat, however, produced no increase in MDA level in spite of an appearance of DMPO-OOH signal, indicating that paraquat also plays an important role. On the other hand, Desferal, a ferric chelator, showed a concentration-dependent inhibition effect. There was an immediate strong intensity of DMPO-OOH and paraquat signals. We did not, however, observe MDA stimulation at 250 microM Desferal, which confirms that ferrous ion plays an essential role in the lipid peroxidation. These results indicate a combined action of paraquat (or its radical) and superoxide on the accessibility of ferrous ion, including its release from the complex with phosphate, which may be an endogenous chelator. The possibility of ternary complex participation is also discussed. 相似文献
36.
Effect of Hypoxia on Na+-K+-Cl− Cotransport in Cultured Brain Capillary Endothelial Cells of the Rat
Abstract: The effect of hypoxia on Na+,K+-ATPase and Na+-K+-Cl? cotransport activity in cultured rat brain capillary endothelial cells (RBECs) was investigated by measuring 86Rb+ uptake as a tracer for K+. RBECs expressed both Na+,K+-ATPase and Na+-K+-Cl? cotransport activity (4.6 and 5.5 nmol/mg of protein/min, respectively). Hypoxia (24 h) decreased cellular ATP content by 43.5% and reduced Na+,K+-ATPase activity by 38.9%, whereas it significantly increased Na+-K+-Cl? cotransport activity by 49.1% in RBECs. To clarify further the mechanism responsible for these observations, the effect of oligomycin-induced ATP depletion on these ion transport systems was examined. Exposure of RBECs to oligomycin led to a time-dependent decrease of cellular ATP content (by ~65%) along with a complete inhibition of Na+,K+-ATPase and a coordinated increase of Na+-K+-Cl? cotransport activity (up to 100% above control values). Oligomycin augmentation of Na+-K+-Cl? cotransport activity was not observed in the presence of 2-deoxy-d -glucose (a competitive inhibitor of glucose transport and glycolysis) or in the absence of glucose. These results strongly suggest that under hypoxic conditions when Na+,K+-ATPase activity is reduced, RBECs have the ability to increase K+ uptake through Na+-K+-Cl? cotransport. 相似文献
37.
38.
Yuriko Osakabe Kazuya Nanto Hiroko Kitamura Shinya Kawai Yuki Kondo Tomoyuki Fujii Keiji Takabe Yoshihiro Katayama Noriyuki Morohoshi 《Planta》1996,200(1):13-19
The polypeptide encoded by the partial fragment of cDNA of phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), PALcDNAl (Osakabe et al., 1995, Plant Sci. 105: 217–226), isolated from Populus kitakamiensis (P. sieboldii x P. grandidentata), was expressed in Escherichia coli cells. The polypeptide was purified and an antiserum raised against it. The antiserum recognized a protein of 77 kDa on nitrocellulose blots after sodium dodecyl sulfate-poly-acrylamide gel electrophoresis of total protein and the partially purified PAL protein from P. kitakamiensis. Moreover,the antiserum recognized a protein on the blot after non-denaturing polyacrylamide gel electrophoresis of P. kitakamiensis proteins and this protein had PAL activity. Furthermore, the antibody inhibited PAL activity of extracts from stem tissues. These results showed that the antiserum against the partial PAL peptide recognized only the PAL subunits in extracts of P. kitakamiensis. Immunolocalization studies of P. kitakamiensis tissues revealed that the PAL protein was specifically localized in the xylem and the phloem fibers and no immunogold signal was found in the epidermis, the cortex, the pith, or the cambium of either stems or leaves.Abbreviations IgG
immunoglobulin G
- IPTG
isopropylthio--d-galactoside
- PAL
phenylalanine ammonia-lyase
The authors thank Dr. Kunio Hata of Nippon Paper Industries Co., Ltd. (Japan) for supplying P. kitakamiensis. This work was supported in part by a grant-in-aid for Scientific Research from the Ministry of Education, Science and Culture of Japan (No. 07406008). 相似文献
39.
Preparation of biologically active Ascaris suum mitochondrial tRNAMet with a TV-replacement loop by ligation of chemically synthesized RNA fragments. 下载免费PDF全文
T Ohtsuki G Kawai Y Watanabe K Kita K Nishikawa K Watanabe 《Nucleic acids research》1996,24(4):662-667
Ascaris suum mitochondrial tRNA Met lacking the entire T stem was prepared by enzymatic ligation of two chemically synthesized RNA fragments. The synthetic tRNA could be charged with methionine by A.suum mitochondrial extract, although the charging activity was considerably low compared with that of the native tRNA, probably due to lack of modification. Enzymatic probing of the synthetic tRNA showed a very similar digestion pattern to that of the native tRNA Met, which has already been concluded to take an L-shape-like structure [Watanabe et al. (1994) J. Biol. Chem., 269, 22902-22906]. These results suggest that the synthetic tRNA possesses almost the same conformation as the native one, irrespective of the presence or absence of modified residues. The method of preparing the bizarre tRNA used here will provide a useful tool for elucidating the tertiary structure of such tRNAs, because they can be obtained without too much difficulty in the amounts necessary for physicochemical studies such as NMR spectroscopy. 相似文献