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61.
Tanaka Osamu; Nasu Yutaka; Takimoto Atsushi; Kugimoto Mamoru 《Plant & cell physiology》1982,23(7):1291-1296
The effect of copper on flowering and growth of Lemna paucicostata6746 and Lemna gibba G3 in a copper-containing medium is nullifiedby the addition of EDTA, ammonium ions or salicylic acid tothe medium or a decrease in its nitrate concentration. Thesefactors were examined for their effects on the absorption ofcopper by the plants. The addition of EDTA to the medium completelyinhibited the absorption of copper in both species, thus eliminatingthe copper effect. Ammonium ions also inhibited copper absorption,their effectiveness rising with their concentration. Loweringthe nitrate concentration in the medium nullified the coppereffect on flowering in L. paucicostata 6746, and the additionof salicylic acid to the medium also nullified the copper effectin L. gibba G3, both without affecting the absorption of copper. (Received June 7, 1982; Accepted August 27, 1982) 相似文献
62.
Rice plants (IR26 and Latisail) obtained at near heading stage from a wetland field were transferred to water culture and exposed to 15N2 in a gas-tight growth chamber for 7 days to measure N2-fixing activities associated with the rice. The activities measured varied from 6.5 to 11.6 μmol of N2 fixed per hill per day. The outer leaf sheath had about 2.5 times higher N2-fixing activities per unit weight than the root. Slight activities were also found in the basal node and inner leaf sheath. Wrapping basal parts of the stem with aluminum foil did not decrease the activities of N2 fixation in these parts. Thus, the outer leaf sheath as well as the root are N2-fixing sites in rice plants. N2 fixation found in above-ground parts is not due to photoautotrophic organisms. Less than 10% of the fixed nitrogen was translocated from the fixing sites to the leaf blades and the young panicles. 相似文献
63.
Jun-Ichi Hayashi Osamu Gotoh Yusaku Tagashira 《Archives of biochemistry and biophysics》1980,205(1):27-35
Previous studies showed that stimulation of mouse mitochondrial ATPase activity of tumor cells, fetal liver, and adult brain by the uncoupler 2,4-dinitrophenol was markedly suppressed during incubation of the mitochondria with the uncoupler (J.-I. Hayashi et al., 1980, Biochem. Biophys. Res. Commun.92, 261–267). The present work showed the reason for this suppression. More than half the endogenous Mg2+ leaked from mitochondria of all tumor cells tested, and of fetal liver and adult brain during incubation with the uncoupler, while only about 30% of the endogenous Mg2+ leaked from mitochondria of other normal tissues. The effect of the uncoupler on Mg2+ leakage from liver mitochondria changed from the fetal to the adult type within about 30 min after birth. In hypotonic medium, normal liver mitochondria also lost more than half their total Mg2+ and concomitantly stimulation of their ATPase activity by uncoupler was considerably reduced. Exogenously added Mg2+ could reverse this reduced effect of the uncoupler on ATPase activity of mitochondria from normal tissues and tumor cells. These results show that the endogenous Mg2+ content of mitochondria directly affects the stimulation by uncoupler of ATPase activity of mitochondria from both normal tissues and tumor cells. Thus, mitochondria of all tumor cells tested, and of fetal liver and adult brain are leaky to Mg2+ during incubation with uncoupler and as a result of the leakage, the stimulatory effect of the uncoupler on their ATPase activity is greatly reduced. 相似文献
64.
Osamu Gotoh Jun-Ichi Hayashi Hiromichi Yonekawa Yusaku Tagashira 《Journal of molecular evolution》1979,14(4):301-310
Summary We have developed a theory to estimate the degree of sequence divergence between related DNAs from the comparison of restriction endonuclease recognition sites. Two major improvements have been made upon a similar method reported by Upholt (1977). First, the most probable value is calculated by the collective use of all available data. This reduces intrinsic statistical error and extends the analyzable range of sequence divergence. Second, all variables are redefined so that they have strict mathematical implications. This corrects a serious error arising from the misinterpretation of the meaning of the fraction of conserved cleavage sites. With this refined method, sequence divergence between rat and mouse mitochondrial DNAs (mtDNAs) was calculated to be about 25% substitutions/nucleotide, which is in good agreement with the DNA-DNA hybridization data obtained by Jakovcic et al. (1975). It was also estimated that the three types of rat mtDNAs differ from one another by 0.3 ~1% of total base pairs. These values are 2 ~5 times smaller than those obtained with the conventional method. 相似文献
65.
66.
From dried leaves of Panax pseudo-ginseng subsp. himalaicus collected in Eastern Himalaya, new dammarane saponins, named pseudo-ginsenosides-F11 and -F8 were isolated along with the known Ginseng-root saponins, ginsenosides-Rb3, Rd and -Re. Pseudo-ginsenoside-F8 was proved to be a mono-acetyl-ginsenoside-Rb3 and the location of its acetyl group was established mainly by 13C NMR spectroscopy. Pseudo-ginsenoside-F11, was identified as the 6-O-α-rhamnopyransyl(1 → 2)-β-glucopyranoside of 3β,6α,12β,25-tetrahydoxy-(20S,24R)-epoxy-dammarane. The C-24 configuration of ocotillone and its related triterpenes was confirmed to be 24R excluding the recent comment by Lavie et al. 相似文献
67.
Masanori Fukushima Taketoshi Kato Ryuzo Ueda Kazuo Ota Shuh Narumiya Osamu Hayaishi 《Biochemical and biophysical research communications》1982,105(3):956-964
Cytotoxic actions of various prostaglandins were examined on L1210 mouse leukemia and several human leukemia cell lines, and prostaglandin D2 (PGD2) was found most active. PGD2 exerted a dose dependent inhibition of L1210 cell growth over 3.6 μ. At 14.3 μ growth was completely inhibited, and the number of viable cells remarkably decreased during culture. Microscopically the remaining cells showed degenerative changes with many vacuoles in their cytoplasm. The IC50 value of PGD2 on L1210 cell growth was calculated to be 6.9 μ (2.4 μg/ml), and at this concentration the DNA synthesis in 24 hr cultured cells was also decreased to a half of the level in the control cells. Such growth inhibition by PGD2 was also found at similar concentrations with several human leukemia cell lines such as NALL-1, RPMI-8226, RPMI-8402, and Sk-Ly-16. Among other prostaglandins tested, PGA2 showed a comparable, and PGE2 a less but significant growth inhibitory activity, while PGB2, PGF2α and PGI2 had no such effects on cell proliferation at 14.3 μ concentration. These results suggest a potential antineoplastic activity of PGD2. 相似文献
68.
Osamu Suzuki Hideki Hattori Makoto Sawada Toshiharu Nagatsu Naomasa Miki Haruhiro Higashida 《Neurochemistry international》1983,5(5):599-601
Mouse neuroblastoma × rat glioma NG108-15 hybrid cells contain a considerable amount of serotonin, and possess small but significant tryptophan hydroxylase activity. The results suggest that NG108-15 hybrid cells are serotonergic, in addition to the known cholinergic property. 相似文献
69.
70.
Cellular localization of thiol-proteinase inhibitor in the epidermis of the newborn rat 总被引:4,自引:0,他引:4
Dr. Kimie Fukuyama Osamu Ohtani Toshihiko Hibino William L. Epstein 《Cell and tissue research》1982,222(2):313-323
Summary In cichlid, poecilid and centrarchid fishes luteinizing hormone releasing hormone (LHRH)-immunoreactive neurons are found in a cell group (nucleus olfactoretinalis) located at the transition between the ventral telencephalon and olfactory bulb. Processes of these neurons project to the contralateral retina, traveling along the border between the internal plexiform and internal nuclear layer, and probably terminating on amacrine or bipolar cells. Horseradish peroxidase (HRP) injected into the eye or optic nerve is transported retrogradely in the optic nerve to the contralateral nucleus olfactoretinalis where neuronal perikarya are labeled. Labeled processes leave this nucleus in a rostral direction and terminate in the olfactory bulb. The nucleus olfactoretinalis is present only in fishes, such as cichlids, poecilids and centrarchids, in which the olfactory bulbs border directly the telencephalic hemispheres. In cyprinid, silurid and notopterid fishes, in which the olfactory bulbs lie beneath the olfactory epithelium and are connected to the telencephalon via olfactory stalks, the nucleus olfactoretinalis or a comparable arrangement of LHRH-immunoreactive neurons is lacking. After retrograde transport of HRP in the optic nerve of these fishes no labeling of neurons in the telencephalon occurred. It is proposed that the nucleus olfactoretinalis anatomically and functionally interconnects and integrates parts of the olfactory and optic systems. 相似文献