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21.
Masashi Yamaguchi Theodore Yanos Tomoko Yamaguchi Abel Lajtha 《Developmental neurobiology》1969,1(4):419-433
When rat sciatic nerves were incubated with C14l-lysine, l- or d-glutamate, or d-l γ-aminoisobutyrate, the labeled compounds penetrated the nerve, and the level of lysine and leucine after 1 hr was higher in the nerve than in the medium. The level increased with time, and at 24 hr glutamate levels also were higher in the nerve than in the medium. Lowering the temperature strongly inhibited uptake, while other conditions such as absence of glucose, absence of sodium, or the presence of cyanide inhibited uptake by nerve less than uptake by brain slices. The uptake against a concentration gradient, and inhibitions of this uptake by metabolic inhibitors and by structural analogs, were interpreted as showing the presence of transport processes for amino acids in peripheral nerves with characteristics similar to such transport processes in the central nervous system. 相似文献
22.
Isolated microspores of Chinese cabbage (Brassica campestris ssp. pekinensis) were incubated in modified NN medium containing 10% sucrose in darkness at 33°C for one day followed by culture at 25°C. After 14 days of culture, microspores developed into embryos ranging from globular to cotyledonary stage. Plants were regenerated after transfer of embryos to medium containing 3% sucrose and no plant growth regulators.Abbreviations NN
Nitsch and Nitsch
- MS
Murashige and Skoog
- NAA
naphthaleneacetic acid
- BA
6-benzylaminopurine 相似文献
23.
Hiroaki Kataoka Kazuki Nabeshima Naoto Komada Masashi Koono 《Virchows Archiv. B, Cell pathology including molecular pathology》1989,57(1):157-165
Two new human cell lines, RCM-1 and CoCM-1, have been established from primary colorectal adenocarcinomas. Both cell lines
were unique in that the cultures secreted trypsin inhibitors in vitro. The activities of these inhibitors were accumulated
in serum-free media of both cell lines over a period of several days. Two inhibitors (PI-1 and PI-2) were isolated from serum-free
conditioned medium in which RCM-1 was grown by anion-exchange and gel filtration high-performance liquid chromatography. PI-1
inhibited trypsin and chymotrypsin strongly, and pancreatic elastase weakly. Its molecular weight was about 57 kilodaltons
(Kd) as determined by gel filtration chromatography. It cross-reacted with the antiserum elicited against human α1-antitrypsin in double immunodiffusion. PI-1 corresponding to α1
- antitrypsin was also demonstrated immunohistochemically in both cell lines. PI-2 inhibited trypsin strongly, and chymotrypsin,
kallikrein and plasmin weakly. It had higher molecular weight (200–300 Kd) than that of PI-1, and did not crossreact with
antisera against human α1-antitrypsin, α2-macroglobulin, α1-antichymotrypsin, α2-plasmin inhibitor, inter-α-trypsin inhibitor and urinary trypsin inhibitor. RCM-1 and CoCM-1 are the first colorectal adenocarcinoma
cell lines that secrete functionally active trypsin inhibitors, including α1-antitrypsin in vitro, and are useful for the study of tumor-cell derived proteinase inhibitors. 相似文献
24.
Masashi Yamada Toshihiko Ikeuchi Saburo Aimoto Dr. Hiroshi Hatanaka 《Neurochemical research》1996,21(7):815-822
PC12h-R cell, a subclone of PC12 cells, exhibited a neuron-like phenotype, including neurite outgrowth and increased acetylcholinesterase
activity, in response to epidermal growth factor (EGF) as well as nerve growth factor (NGF). We examined the mechanism by
which EGF induced the neuronal differentiation in PC12h-R cells. The EGF-induced neuronal differentiation of PC12h-R cells
was not blocked by K252a, whereas that induced by NGF was. EGF induced sustained tyrosine phosphorylation of the EGF receptor
in PC12h-R cells, but not in the parent PC12h cells, which do not show neuronal differentiation in response to EGF. In addition,
the rate of EGF-induced down-regulation of the EGF receptor in PC12h-R cells was decreased compared with that in PC12h cells.
Furthermore, we found that the duration of EGF-induced tyrosine phosphorylation of the EGF receptor in PC12h-R cells was similar
to that of NGF-induced tyrosine phosphorylation of p140
trkA in PC12h cells. The EGF-induced phosphorylation of the EGF receptor in PC12h cells was less sustained than that of p140
trkA by NGF in PC12h cells. These findings suggested that the EGF-induced neuronal differentiation of PC12h-R cells is due to
the sustained activation of the EGF receptor, resulting from the decreased down-regulation of the EGF receptor and that the
duration of the receptor tyrosine kinase activity determines the cellular responses of PC12 cells. We concluded that sustained
activation of the receptor tyrosine kinase induces neuronal differentiation, although transient activation promotes proliferation
of PC12 cells.
Special issue dedicated to Dr. Hans Thoenen. 相似文献
25.
By using monoclonal antibodies directed against discoidin II,we have isolated cDNA clones from axenically grown Ax-2 cells.On cDNA clone (D2) condtained a 1.2-k.b insert encoding theentire discoidin II protein, which is conposed of 257 aminoacid residuces and has a calculated molecular mass of 28,574.The amino acid sequences, determined by Edman degradation ofsix tryptic peptides of discoidin II, were identical to thosededuced from the cDNA sequences. The protein bears no resemblanceto any proteins in the data banks, except that its sequenceis 49% identical with the amino acid sequence of discoidin I.Discoidin II shares with discoidin I both a carbohydratebindingsite and an Arg-Gly-Asp (RGD) sequence, which has been foundin fibronectin in mammalian cells. With the onset of aggregation(8 h of development), a 1.3-kb discoidin II mRNA begins to accumulate.A similar pattern of regulation occurs at the protein level.
1Present address: MRC Laboratory for Molecular Cell Biology,University College London, Gower Street, London, WC1E 6BT UnitedKingdom 相似文献
26.
Fujimoto J Nishigaki M Hori M Ichigo S Morishita S Tamaya T 《Journal of biomedical science》1995,2(2):160-165
The mechanism of known receptor-mediated androgen effects on the endometrial stroma was studied in endometrial fibroblasts derived from human uterus. 17-Estradiol (E) induced the expressions of androgen receptor (AR) mRNA, and predominantly increased the level of testosterone-binding sites (TBS) in uterine endometrial fibroblasts. The effect on the level of dihydrotestosterone-binding sites (DHTBS) was similar but smaller. This result suggests that the AR mRNA expressed might encode TBS, but probably not DHTBS. The TBS level increased by estrogen was down-regulated by testosterone (T) + E, but the AR mRNA expression increased by E was not down-regulated by E + T in the fibroblasts. Although the synthesis rate of AR was slightly increased (p<0.05) by E alone or E + T, the degradation rate of AR was significantly accelerated (p<0.05) by E + T in the fibroblasts. This result suggests that T might stimulate the metabolic rate of TBS, but does not inhibit the synthesis rate of AR mRNA to TBS in endometrial fibroblasts. 相似文献
27.
The objective of this study was to investigate the in vitro and in vivo developmental abilities of equine embryos cryopreserved by vitrification. Twenty-eight embryos were recovered from Native pony and Thoroughbred mares at Days 5 to 7 by nonsurgical uterine flushing (detection of ovulation=Day 0). The vitrification solution contained 40% ethylene glycol, 18% Ficoll, and 0.3 M sucrose in PBS. The embryos were placed for 1 to 2 min in vitrification solution (Group 1) or following exposure to 20% ethylene glycol in PBS for 10 to 20 min (Groups 2 and 3). Single embryos were loaded in 0.25-ml straws, cooled for 1 min in liquid nitrogen vapor and immersed in liquid nitrogen. Straws were warmed in water (20 degrees C, 20 sec), and the contents were expelled with 0.5 M sucrose in PBS. Then the sucrose was diluted in 1-step (Groups 1 and 2) or 4-steps (Group 3). Embryos (n=21) were cultured for 120 h in TCM199 supplemented with 10% fetal bovine serum at 37 degrees C in 5% CO(2) in air and evaluated morphologically. Development to the hatching or hatched blastocyst stage was obtained in 0 7 , 4 7 and 4 7 embryos in Groups 1, 2 and 3, respectively. An additional 7 embryos were vitrified-warmed according to the treatment of Group 2 (4 embryos) and Group 3 (3 embryos). Five embryos were selected after in vitro culture for 4 h and were transferred nonsurgically into the uterine horn of Day-4 recipient mares. Transfer of 2 embryos (both Day-6 blastocysts: Group-2 treatment) resulted in pregnancies with a viable fetus at Day-60 of the gestation period. 相似文献
28.
Light-induced changes of cytosolic pH (pHc) and the plasmalemmapotential (Em) in dark-adapted leaf cells of the aquatic plant,Egeria densa were measured simultaneously with double-barreledpH-sensitive microelectrodes. Upon illumination, pHc increasedtransiently and then decreased to a level that was lower thanthe original value, while the plasmalemma was greatly hyperpolarizedafter an initial small depolarization. DCMU inhibited the light-inducedchanges in both pHc and Em. DCMU acted without directly inhibitingthe electrogenic proton pump in the plasmalemma since a decreasein pHc caused by treatment with butyrate (H+-loading) hyperpolarizedthe plasmalemma in DCMU-pretreated cells. N.N-Dicyclohexylcarbodiimide(DCCD) also inhibited the light-induced changes in both pHcand Em. This result may be explained by direct inhibition ofthe proton pump in the plasmalemma by DCCD since the decreasein pHc caused by butyrate did not induce membrane hyperpolarizationin DCCD-treated leaf cells. Fusicoccin induced membrane hyperpolarizationand slight acidification of the cytosol. DCCD inhibited thefusicoccin-induced changes in both pHc and Em. The mechanismof the light-induced changes in pHc is discussed in relationto activities of the proton pump in the plasmalemma and photosynthesis. (Received January 10, 1994; Accepted June 9, 1994) 相似文献
29.
Naoyuki Miyashita Yoshifumi Kubota Masashi Kimura Masamitsu Nakajima Yoshihito Niki Rinzo Soejima Akira Matsumoto 《Microbiology and immunology》1994,38(11):857-864
The isolation of Chlamydia pneumoniae, especially from elderly persons, is generally not easy. Recently, we succeeded in isolating a chlamydial strain, which was designated KKpn-15, from a 57-year-old man suffering from acute bronchitis. It was compared with well established strains of C. pneumoniae, C. trachomatis and C. psittaci, and its biological properties, such as the morphology of elementary bodies (EBs) and inclusions, and the immunochemistry of EB proteins, were investigated. Based on the results obtained in the present study, it was confirmed that the new chlamydial strain, KKpn-15, is a member of the C. pneumoniae strain and that the organisms of KKpn-15 are useful as an antigen for the serodiagnosis and epidemiology of C. pneumoniae infection. 相似文献
30.
Jianyu Zheng Kohei Irifune Kouji Hirai Masashi Nakata Ryuso Tanaka Hiromichi Morikawa 《Journal of plant research》1994,107(4):365-369
In situ hybridization with a biotin-labeled rice ribosomal DNA (rDNA) probe to the somatic metaphase chromosomes of six species ofPhaseolus andVigna (P. angularis, P. calcaratus, P. coccineus, P. vulgaris, V. sesquipedalis andV. sinensis) was done to determine the sites of rDNA. Hybridization signals were present in the terminal and subterminal chromosome regions
of each of the six species. The number of rDNA sites was two inP. angularis andP. calcaratus, four inP. coccineus andP. vulgaris, and six inV. sesquipedalis andV. sinensis. 相似文献