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排序方式: 共有2073条查询结果,搜索用时 31 毫秒
11.
Hisashi Miyazaki Masatoshi Iida Yoshimasa Matsunaga Toshihiko Fujii Keiko Nambu Hideki Amejima Yoshinori Oh-e Hideo Furukawa Yukiharu Matsui Yasunobu Sohmura Masahisa Hashimoto 《Biotherapy》1989,1(1-2):47-57
The mode of antitumor action of rHu-TNF was elucidated in BALB/c mice bearing Meth A fibrosarcoma 7 days after transplantation with respect to time course, dose-response relationships and selectivity of the effects. The maximal cytotoxic effect on tumor cells revealed by inhibition of DNA synthesis and maximal lesional effect on tumor vasculature revealed by change in blood pool-size in the tissue were detected at 30 min and I h after administration of rHu-TNF, respectively. The dose-response relationship between cytotoxic and tumoricidal effects of rHu-TNF was irrespective of administration route. ED50s of these antitumor effects afteri.v. administration of rHu-TNF were about 50 times as high as ED50s afteri.t. administration. ED50 ofi.t. given rHu-TNF for vascular effect was about 20 times as high as that for cytotoxicity while ED50 ofi.v. rHu-TNF for vascular effect was only 2–3 times as high as that for cytotoxicity. The whole body autoradiographies with [125I] HSA giveni.v. to see the blood influx into tumor tissue and [14C]thymidine given i.v. to see DNA synthesis in the whole body after administration of rHu-TNF revealed that the distribution of radioactivity was markedly changed in the tumor alone without any detectable change in other whole body tissues.In conclusion, thein vivo antitumor effect of rHu-TNF giveni.t. ori.v., appears to be exerted through the direct action on Meth A sarcoma rather than indirectly on tumor vasculature. Under present conditions, the effect of rHu-TNF in the whole body tissues seems rather selective on cells and vasculature of the tumor. 相似文献
12.
Hidenori Sassa Takeshi Nishio Yasuo Kowyama Hisashi Hirano Takato Koba Hiroshi Ikehashi 《Molecular & general genetics : MGG》1996,250(5):547-557
Stylar riboncleases (RNases) are associated with gametophytic self-incompatibility in two plant families, the Solanaceae and the Rosaceae. The self-incompatibility-associated RNases (S-RNases) of both the Solanaceae and the Rosaceae were recently reported to belong to the T2 RNase gene family, based on the presence of two well-conserved sequence motifs. Here, the cloning and characterization of S-RNase genes from two species of Rosaceae, apple (Malus × domestica) and Japanese pear (Pyrus serotina) is described and these sequences are compared with those of other T2-type RNases. The S-RNases of apple specifically accumulated in styles following maturation of the flower bud. Two cDNA clones for S-RNases from apple, and PCR clones encoding a further two apple S-RNases as well as two Japanese pear S-RNases were isolated and sequenced. The deduced amino acid sequences of the rosaceous S-RNases contained two conserved regions characteristic of the T2/S-type RNases. The sequences showed a high degree of diversity, with similarities ranging from 60.4% to 69.2%. Interestingly, some interspecific sequence similarities were higher than those within a species, possibly indicating that diversification of S-RNase alleles predated speciation in the Rosaceae. A phylogenetic tree of members of the T2/S-RNase superfamily in plants was obtained. The rosaceous S-RNases formed a new lineage in the tree that was distinct from those of the solanaceous S-RNases and the S-like RNases. The findings suggested that self-incompatibility mechanisms in Rosaceae and Solanaceae are similar but arose independently in the course of evolution. 相似文献
13.
14.
Masahiro Tohkin Shinji Kakudo Hisashi Kasai Hitoshi Arita 《Cancer immunology, immunotherapy : CII》1994,39(3):155-160
The inhibitory effect of murine interferon (muIFN) on humoral hypercalcemia in nude mice bearing lower-jaw cancer (LJC-1-JCK), in which parathyroid-hormone(PTH)-related protein is responsible for causing humoral hypercalcemia by activating bone resorption, was examined in comparison with that of a new bisphosphonate, 4-amino-1-hydroxybutylidene-1,1-bisphosphonate (alendronate), muIFN was injected into tumor-bearing nude mice for 5 days before the establishment of hypercalcemia. The increase of plasma calcium concentration was delayed and this effect continued for more than 6 days even after the injection was stopped. Alendronate markedly suppressed hypercalcemia in tumor-bearing nude mice but this inhibitory effect continued for less than 6 days. Neither muIFN nor alendronate affected the tumor volume or serum PTH-related protein concentration. Injection of muIFN into mice for 3 days almost completely abolished the formation of multinucleated osteoclast-like cells from bone marrow cells in vitro, whereas injection of alendronate into mice had no effect. These findings suggested that muIFN suppressed the formation of osteoclasts, resulting in the prolonged decrease of plasma calcium concentration in hypercalcemic tumor-bearing nude mice, whereas alendronate is cytotoxic to functionally mature osteoclasts and inhibited osteoclastic bone resorption, resulting in a marked decrease in the plasma calcium concentration in tumor-bearing hypercalcemic nude mice. 相似文献
15.
Noriko Arase-Fukushi Hisashi Arase Bingyan Wang Mari Hirano Kazumasa Ogasawara Robert A. Good Kazunori Ono 《Microbiology and immunology》1993,37(11):883-894
Allo-chimerism and clonal elimination of self antigen (Ag) (Ia + Mls-1a) reactive Vβ6+ T cells were analyzed and compared between allogeneic bone marrow (BM) chimeras reconstituted with BM cells which had been treated with anti-Thy-1 monoclonal antibody (mAb) plus complement (C) (T– chimeras) and BM chimeras which had been reconstituted with BM cells pretreated with anti-Thy-1 mAb alone (T+ chimeras). When lethally irradiated AKR (Mls-1a) mice were reconstituted with BM cells from B10 or B10 H-2 congenic mice, both T+ and T– chimeras were entirely free of signs of graft-versus-host reaction (GVHR). However, complete replacement of the AKR lymphoid tissues by donor BM cells was accomplished at an early stage in T+ chimeras but not in T– chimeras. On the other hand, clonal elimination of Vβ6+ T cells reactive to the recipient Ag (Mls-1a) was abolished in T+ chimeras but successfully induced in T– chimeras. The Vβ6+ T cells not eliminated in T+ chimeras showed depressed responses against Mls-1a antigens. The findings herein demonstrate that T cells which contaminate a BM inoculum survive in recipient mice after treatment with anti-Thy-1 mAb without C in vitro followed by BMT. The surviving T cells have been estimated to represent fewer than 0.5% of the BM cells inoculated. These cells appear to accelerate the full replacement of recipient lymphoid tissues by donor cells. Furthermore, the T cells which survive in the marrow inoculum influence eventually the development of a tolerant state in the T cell repertoire of the donor. 相似文献
16.
Hisashi Nagata 《Ecological Research》1993,8(1):1-9
The breeding sites of Styan's grasshopper warblers are restricted to small islands and distributed discretely. The study on
the marked population was conducted on two islets, Okitsu-jima and Ohtsukue-jima, located near Fukuoka, Japan, from 1981 to
1989. About 20 and 70 birds bred on the two islets, respectively, and the mean density of breeding pairs was 25.5 ha−1. The dispersal pattern and population, structure were examined. Adult birds returned to the same breeding site. Males always
reoccupied the same territory as in previous years but females not. Males were more philopatric and only female yearlings
dispersed over long distances and moved between the breeding sites in Hakata Bay. The returning rate was 0.57 for adults,
and 0.21 for juveniles. The age distribution of birds at Ohtsukue-jima was almost stable, while that at Okitsu-jima was unstable
because it was a marginal habitat for the birds. Estimating from the dispersal pattern and age structure of this warbler the
population near Fukuoka consists of only four islets and is almost stable. 相似文献
17.
Molecular cytological evidence for gradual telomere synthesis at the broken chromosome ends in wheat
Hisashi Tsujimoto 《Journal of plant research》1993,106(3):239-244
Telomere formation of the normal and broken chromosomes of common wheat,Triticum aestivum, was investigated byin situ hybridization using the biotin-labeled probe of telomere repetitive sequences (pAtT4) ofArabidopsis thaliana with subsequent amplification by an antibody. After double and triple amplification, prominent signals appeared at all the
telomeric regions of the normal chromosomes.
Prominent signals also emerged at the broken ends of the telocentric and deletion chromosomes that had passed through more
than one generation since the appearance. However, broken ends that had passed through only the stages of gametogenesis, fertilization,
embryogenesis and root development did not show complete signals such as found in normal telomeres. These findings indicate
that a certain time or stage is required for synthesis of the telomeric repetitive sequences with a complete length. Nevertheless,
because the broken ends without complete telomere sequences were also healed, restoration of the normal complement of telomere
sequences is not necessary for healing of broken ends. 相似文献
18.
Kajiwara Hideyuki; Okuyama Tsuneo; Fukuda Minoru; Hirano Hisashi; Oono Kiyoharu 《Plant & cell physiology》1992,33(1):27-32
A protein with relatively high homology in its N-terminal aminoacid sequence to animal parvalbumin and oncomodulin has beenidentified in leaves of rice (Oryza sativa L.). The PV-likeprotein has a relative molecular mass of 27,000 and an isoelectricpoint of 5.0. This protein was partially purified by ion-exchangechromatography, and the purified protein was found to have Ca2+-bindingactivity in a microscale Ca2+-binding assay. Furthermore, anantiserum raised against a synthetic oligopeptide based on theN-terminal amino acid sequence of this protein cross-reactedwith protein not only from rice but also from other monocotyledonousplants. (Received October 17, 1990; Accepted October 17, 1991) 相似文献
19.
Hisashi Hisabayashi 《Biological Sciences in Space》2003,17(4):324-340
It is much easier to find extraterrestrial intelligence than to detect simple organisms living on other planets. However, it is hard to communicate with such intelligence without the mutual understanding of inter-stellar communication protocol. The radio SETI (The Search for Extra-Terrestrial Intelligence) was initiated with the pioneering work of F. Drake in 1960, one year after the historical SETI paper by Cocconi and Morrison. This talk explains that SETI evolves with two bases of science; the understanding of our universe and the development of technology. Since SETI has had strong connection with radio astronomy from its early beginning, the impacts of radio astronomical findings and technological breakthrough can be seen in many aspects of the SETI history. Topics of this talk include the detection of microwave 3 K background radiation in the universe. Interstellar atomic and molecular lines found in radio-wave spectra provide the evidence of pre-biotic chemical evolution in such region. Radio telescope imaging and spectral technique are closely associated with methodology of SETI. Topics of the talk extend to new Allen Telescope Array and projected Square Kilometer Array. Recent optical SETI and the discoveries of extra solar planets are also explained. In the end, the recent understanding of our universe is briefly introduced in terms of matter, dark matter and dark energy. Even our understanding of the universe has been evolutionarily revolved and accumulated after 1960, we must recognize that our universe is still poorly understood and that astronomy and SETI are required to proceed hand in hand. 相似文献
20.
Parasitic specialization ofGeotrichum candidum citrus race, the causal agent of citrus sour rot, was investigated. Of seven isolates tested for pathogenecity, all could
infect ten species of citrus fruits and edible parts of five species of noncitrus crops. Only one isolate (Ap2), isolated
from soil of an apple orchard, could infect apple fruit. 相似文献