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排序方式: 共有1319条查询结果,搜索用时 15 毫秒
1.
Hypoxia-induced fibre type transformation in rat hindlimb muscles
Histochemical and electro-mechanical changes 总被引:1,自引:0,他引:1
Histochemical and electro-mechanical changes 总被引:1,自引:0,他引:1
Kazuo Itoh Toshio Moritani Koji Ishida Chiyoko Hirofuji Sadayoshi Taguchi Minoru Itoh 《European journal of applied physiology and occupational physiology》1990,60(5):331-336
Twelve male Sprague-Dawley rats (21 days old) were randomly assigned into two experimental groups: sea level control (CONT) and hypobaric hypoxia (HYPO). The HYPO rats were kept in an hypobaric chamber maintaining a simulated altitude of 4000 m (61.1 kPa). After 10 weeks of treatment, the rat hindlimb muscles [soleus (SOL) and extensor digitorum longus (EDL)] were subjected to histochemical and electro-mechanical analyses. Results indicated that compared to CONT the HYPO SOL muscle had a significantly greater relative distribution of fast-twitch-oxidative-glycolytic (FOG) fibres (28.9% SEM 2.0 vs 18.3% SEM 1.8, P less than 0.01) with a significant decrease in slow twitch oxidative fibre distribution (69.5% SEM 2.4 vs 82.9% SEM 3.1, P less than 0.01). Compared to CONT the HYPO EDL muscle also manifested a significant increase in FOG fibre distribution (51.6% SEM 0.8 vs 46.6% SEM 1.1, P less than 0.01), but this was accompanied by a significant decrease in fast twitch glucolytic fibres (44.3% SEM 0.9 vs 49.2% SEM 1.7, P less than 0.05). These histochemical fibre type transformations accompanied significant and expected changes in the electro-mechanical parameters tested in situ, e.g. maximal twitch force, maximal rate of force development, contraction time, half relaxation time, force: frequency curve, and fatigability. It was concluded that chronic hypobaric hypoxia could have a potent influence upon the phenotype expression of muscle fibres. 相似文献
2.
3.
Toshio Shimada Dr. Yoshimasa Kosako Yasunori Isshiki Kazuhito Hisatsune 《Current microbiology》1992,25(4):215-217
The O antigen of enterohemorrhagicEscherichia coli O157:H7 is identical with that ofSalmonella O301 and is also related toSalmonella O301302 in an a-a, b type of relationship. 相似文献
4.
Naoki Yamashita Isao Nakanishi Yasunori Okada 《Virchows Archiv. B, Cell pathology including molecular pathology》1991,60(1):57-66
Arthritis was induced by injecting cationic amidated bovine serum albumin (aBSA) (pI approximately 9.2) into the knee joint of immunized guinea pigs and the mechanisms of articular cartilage destruction were studied morphologically and biochemically. Marked synovitis associated with polymorphonuclear leukocyte (PML) infiltration occurred within 1 day of the challenge. Articular cartilage infiltrated by PMLs was almost completely destroyed after 2 weeks. During the initial destructive process, proteoglycans were depleted from the cartilage and later collagen fibers disappeared. Granulation tissue growing in the inflamed synovium and bone marrow replaced the destroyed cartilage and joint cavity and formed fibrous scar tissue (fibrous ankylosis) by 8 weeks. Subsequently, the knee joints developed cartilagenous ankylosis by 12 weeks and finally bony ankylosis at 28 weeks. Autoradiography using 125I-aBSA and immunofluorescence studies for immunoglobulin (IgG) and complement (C3) demonstrated that the antigen is trapped in all zones of the articular cartilage and serves as a trigger for immune complex formation. Significantly increased neutral proteinase activities against substrates of proteoglycan subunits, [3H]carboxymethylated transferrin and L-pyroglutamyl-L-prolyl-L-valine-paranitroanilide were detected in homogenates of the synovium and cartilage from arthritic knee joints 1 and 2 weeks after induction. Inhibitor studies and pH curves suggested that the proteinase is leukocyte elastase. Measurable amounts of gelatinolytic activity, detected by activation with 4-aminophenylmercuric acetate and inhibited with EDTA, were also present in the same samples, but there was no detectable collagenase activity. The data on SDS-gelatin substrate gel showed that the proteinase is gelatinase derived from PMLs. These results suggest that in aBSA-induced arthritis, elastase and gelatinase from PMLs invading articular cartilage may play important roles in cartilage destruction. 相似文献
5.
In Dunaliella tertiolecta, D. bioculata and D. viridis the activitiesof phosphoenolpyruvate carboxylase and carbonic anhydrase werehigher in the cells grown in ordinary air (low-CO2 cells) thanin those grown in air enriched with 15% CO2 (high-CO2cells), whereas in Porphyridium cruentum R-1 there was no differencein phosphoenolpyruvate carboxylase activity between these twotypes of cells. Apparent Km(NaHCO3) values for photosynthesisin low-CO2 cells of all species tested were smaller than thosein high-CO2 cells. Most of the 14C was incorporated into 3-phosphoglycerate,sugar mono- and di-phosphates during the initial periods ofphotosynthetic NaH14CO3 indicating that both types of cellsin D. tertiolecta are C3 plants. (Received May 27, 1985; Accepted June 25, 1985) 相似文献
6.
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
7.
Integration of Agrobacterium T-DNA into a tobacco chromosome: Possible involvement of DNA homology between T-DNA and plant DNA 总被引:13,自引:0,他引:13
Shogo Matsumoto Yukihiro Ito Tsuyoshi Hosoi Yosuke Takahashi Yasunori Machida 《Molecular & general genetics : MGG》1990,224(3):309-316
Summary We established tobacco tumour cell lines from crown galls induced by Agrobacterium. Restriction fragments containing T-DNA/plant DNA junctions were cloned from one of the cell lines, which has a single copy of the T-DNA in a unique region of its genome. We also isolated a DNA fragment that contained the integration target site from nontransformed tobacco cells. Nucleotide sequence analyses showed that the right and left breakpoints of the T-DNA mapped ca. 7.3 kb internal to the right 25 by border and ca. 350 by internal to the left border respectively. When the nucleotide sequences around these breakpoints were compared with the sequence of the target, significant homology was seen between the region adjacent to the integration target site and both external regions of the T-DNA breakpoints. In addition, a short stretch of plant DNA in the vicinity of the integration site was deleted. This deletion seems to have been promoted by homologous recombination between short repeated sequences that were present on both sides of the deleted stretch. Minor rearrangements, which included base substitutions, insertions and deletions, also took place around the integration site in the plant DNA. These results, together with previously reported results showing that in some cases sequences homologous to those in T-DNA are present in plant DNA regions adjacent to left recombinational junctions, indicate that sequence homology between the incoming T-DNA and the plant chromosomal DNA has an important function in T-DNA integration. The homology may promote close association of both termini of a T-DNA molecule on a target sequence; then TDNA may in some cases be integrated by a mechanism at least in part analogous to homologous recombination.Shogo Matsumoto is on leave from Biochemical Research Institute, Nippon Menard Cosmetic Co., Ltd, Ogaki, Gifu-ken 503, Japan 相似文献
8.
Prosaposin Facilitates Sciatic Nerve Regeneration In Vivo 总被引:3,自引:0,他引:3
Yasunori Kotani Seiji Matsuda Masahiro Sakanaka Keiji Kondoh Shu-ichi Ueno Akira Sano 《Journal of neurochemistry》1996,66(5):2019-2025
Abstract: Prosaposin, a multifunctional protein, is the precursor of saposins, which activate sphingolipid hydrolases. In addition to acting as a precursor for saposins, prosaposin has been shown to rescue hippocampal CA1 neurons from lethal ischemic damage in vivo and to promote neurite extension of neuroblastoma cells in vitro. Here we show that prosaposin, when added to a collagen-filled nerve guide after sciatic nerve transection in guinea pigs, increased dramatically the number of regenerating nerve fibers within the guide. To identify the target neurons of prosaposin during peripheral nerve regeneration, we determined the degree of atrophy and chromatolysis of neurons in the spinal anterior horn and dorsal root ganglia on the prosaposin-treated and untreated side. The effect of prosaposin on large spinal neurons and small neurons of the dorsal root ganglion was more conspicuous. Subsequent immunohistochemistry demonstrated that the atrophy of cholinergic large neurons in the anterior horn is prevented to significant extent by prosaposin treatment. These findings suggest that prosaposin promotes peripheral nerve regeneration by acting on α-motor neurons in the anterior horn and on small sensory neurons in the dorsal root ganglion. The present study raises the possibility of using prosaposin as a tool for the treatment of peripheral nerve injuries. 相似文献
9.
Toshio Ariga Shama Bhat Takashi Kanda Masanaga Yamawaki Tadashi Tai Yasunori Kushi Takeshi Kasama Shizuo Handa Robert K. Yu 《Glycoconjugate journal》1996,13(2):135-145
We analysed the glycolipid composition of glioma cells (N-370 FG cells), which are derived from a culture of transformed human fetal glial cells. The neutral and acidic glycolipid fractions were isolated by column chromatography on DEAE-Sephadex and analysed by high-performance thin-layer chromatography (HPTLC). The neutral glycolipid fraction contained 1.6 µg of lipid-bound glucose/galactose per mg protein and consisted of GlcCer (11.4% of total neutral glycolipids), GalCer (21.5%), LacCer (21.4%), Gb4 (21.1%), and three unknown neutral glycolipids (23%). These unknown glycolipids were characterized as Lewisx (fucosylneolactonorpentaosyl ceramide; Lex), difucosylneolactonorhexaosyl ceramide (dimeric Lex), and neolactonorhexaosyl ceramide (nLc6) by an HPTLC-overlay method for glycolipids using specific mouse anti-glycolipid antibodies against glycolipid and/or liquid-secondary ion (LSI) mass spectrometry. The ganglioside fraction contained 0.6 µg of lipid-bound sialic acid per mg protein with GD1a as the predominant ganglioside species (83% of the total gangliosides) and GM3, GM2, and GM1 as minor components. Trace amounts of sialyl-Lex and the complex type of sialyl-Lex derivatives were also present. Immunocytochemical studies revealed that GD1a and GalCer were primarily localized on the surface of cell bodies. Interestingly, Lex glycolipids and sialyl-Lex were localized not only on the cell bodies but also on short cell processes. Especially, sialyl-Lex glycolipid was located on the tip of fine cellular processes. The unique localization of the Lex glycolipids suggests that they may be involved in cellular differentiation and initiation of cellular growth in this cell line. 相似文献
10.
The reason for failure to initiate fertilization internally was examined in a cottid fish, the elkhorn sculpin, Alcichthys alcicornis which has internal gametic association and external fertilization. While eggs could be activated in calcium free hypertonic media but not be fertilized, fertilization occurred in isotouic media rich in calcium ions. The rate of fertilization was dependent on calcium concentration, and eggs were not fertilized in solutions with a calcium ion concentration of less than 0·57 mmol kg−1 . Calcium ions could be replaced to some extent by magnesium ions, but the former were the more effective in fertilization. Since calcium ion concentration of ovarian fluid of A. alcicornis was 0·41 mmol kg−1 , it was inferred that low calcium concentration in the ovarian fluid was the cause of the failure of A. alcicornis eggs to fertilize internally. 相似文献