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排序方式: 共有1008条查询结果,搜索用时 31 毫秒
831.
Nucleotide sequence of the staphylocoagulase gene: its unique COOH-terminal 8 tandem repeats 总被引:12,自引:0,他引:12
S Kaida T Miyata Y Yoshizawa S Kawabata T Morita H Igarashi S Iwanaga 《Journal of biochemistry》1987,102(5):1177-1186
832.
M Kumada Y Hosaka M Kawabata H Asahi K Kato T Kobayakawa S Hayashi 《Japanese journal of medical science & biology》1987,40(2):89-93
To learn the possible alteration of immune response, hemolytic plaque-forming cells (PFC) produced in the spleen of Schistosoma japonicum infected mice treated with Praziquantel and untreated group were counted. There was no significant difference in the immunesuppression percentage between the treated and untreated groups 1 and 3 weeks after treatment. In 5 weeks after treatment, however, the immunesuppression percentage in the treated mice was markedly reduced in comparison with that of the untreated group. Recovery from immunesuppression appears to be associated with elimination or impairment of adult worms. 相似文献
833.
A low molecular weight protein protease inhibitor was purified from Japanese horseshoe crab (Tachypleus tridentatus) hemocytes. It consisted of a single polypeptide with a total of 61 amino acid residues. This protease inhibitor inhibited stoichiometrically the amidase activity of trypsin (Ki = 4.60 X 10(-10) M), and also had inhibitory effects on alpha-chymotrypsin (Ki = 5.54 X 10(-9) M), elastase (Ki = 7.20 X 10(-8) M), plasmin, and plasma kallikrein. However, it had no effect on T. tridentatus clotting enzyme and factor C, mammalian blood coagulation factors (activated protein C, factor Xa and alpha-thrombin), papain, and thermolysin. The complete amino acid sequence of this inhibitor was determined and its sequence was compared with those of bovine pancreatic trypsin inhibitor (BPTI) and other Kunitz-type inhibitors. It was found that the amino acid sequence of this inhibitor has a high homology of 47 and 43% with those of sea anemone inhibitor 5-II and BPTI, respectively. Thus, this protease inhibitor appeared to be one of the typical Kunitz-type protease inhibitors. 相似文献
834.
Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) have different C-terminal tail structures compared with the rather conservative ring structures which consist of 17 amino acid residues. To examine the different effects of the tail structures of ANP and BNP on their interaction with receptors, we synthesized several peptide analogs and measured their biological actions in three different assay systems. Deletion of the C-terminal tail from rat BNP did not effect the vasorelaxation activity against rat aorta, but it promoted cGMP production in cultured rat aortic smooth muscle cells (RASMC). Deletion of the C-terminal tail from rat ANP diminished both vasorelaxant and cGMP producing activities. In a binding competition assay with RASMC and [125I]rat ANP-(1-28), the competition activities of both ANP and BNP were greatly reduced by C-terminal deletion. In addition, we obtained agonists with novel receptor selectivity. 相似文献
835.
Differential Changes in Levels of mRNAs during Maturation of Wheat Seeds That Are Susceptible and Resistant to Preharvest-Sprouting 总被引:2,自引:0,他引:2
Seed dormancy is strongly related to the physiological conditions,especially as they relate to responsiveness to ABA, of embryocells during maturation of seeds. In this study, seeds of Triticumaestivum L. cv. Chihoku, which showed nondormancy at harvest,and line Kitakei-l354 (referred to as Kitakei), which showedpost-harvest dormancy, were collected 30 days after anthesis(DPA 30) and at the mature stage (DPA 60). Poly(A)+RNA was extractedfrom the embryos of the seeds and translated in a wheat germsystem. The majority of products of translation from the twogenotypes migrated to the same positions in two-dimensionalgels. Levels of six (for polypeptides h, i, k, m, n, and o)out of 14 Chihoku-specific mRNAs decreased dramatically duringseed maturation, concurrently with the loss of dormancy. Bycontrast, levels of 3 (for polypeptides c, e and f) out of 6Kitakei specific mRNAs were maintained during maturation andduring a 48-h imbibition of the dormant seeds but decreasedat germination. Polypeptides n of Chihoku and e of Kitakei hadthe same molecular size and slightly different pI values. Thesetwo polypeptides may be encoded by the same gene and may playsome role in the maintenance of seed dormancy. Levels of mRNAsfor 10 polypeptides, found in both Chihoku and Kitakei embryosat DPA 30, changed to different extents during maturation. Outof the 10 mRNAs, the relative abundance of 4 mRNAs of Kitakeidid not change dramatically during seed maturation, while inChihoku these mRNAs decreased in level or disappeared duringthe same maturation period. In addition, levels of 2 of these4 mRNAs did not decrease significantly during imbibition ofthe dormant Kitakei seeds but disappeared upon treatment forbreaking of dormancy. The maintenance of these mRNAs in thedormant seeds during maturation and imbibition suggests thatthe respective gene products are involved in the maintenanceof dormancy in wheat seeds. (Received December 5, 1991; Accepted April 1, 1992) 相似文献
836.
Enhancement of cytotoxic T lymphocyte growth from spleens of P815-tumor-bearing host mice with mafosfamide 总被引:1,自引:0,他引:1
Thomas H. Inge Shelley K. Hoover James L. Frank Thomas T. Kawabata Kevin P. Bethke Harry D. Bear 《Cancer immunology, immunotherapy : CII》1992,35(2):119-126
Summary Mafosfamide (Mafo) is an analog of cyclophosphamide that does not require hepatic activation and therefore has in vitro activity. The present study was conducted to determine the effects of in vitro treatment with Mafo on the generation and growth of cytotoxic T lymphocytes (CTL) from tumor-bearing host mice (TBH). In contrast to early (day-11) TBH splenocytes, splenocytes from late (days 18–20) P815 TBH mice suppress the in vitro generation of CTL. Treatment of late TBH splenocytes in vitro with 5–15 µM Mafo resulted in a reduced ability of these cells to suppress in vitro CTL generation. Treatment of late TBH splenocytes with 10 µM Mafo also inhibited their ability to suppress adoptive immunotherapy of intradermal tumors with immune splenocytes. These doses of Mafo were selectively toxic to the suppressive effects of late TBH splenocytes, since treatment of early TBH splenocytes with 1–10 µM Mafo did not significantly inhibit CTL generation. Spleen cells from early (days 10–12) TBH mice, carried in long-term in vitro sensitization cultures in the presence of tumor cells and 20 U/ml human recombinant interleukin-2, did not increase in cell number over time. However, when pretreated with 3 µM Mafo, this population of tumor-sensitized lymphocytes demonstrated 450-fold growth over 6 weeks as compared to the static cell numbers for the untreated controls. High levels of tumor-specific cytolytic activity were maintained in these expanded cells. These results suggest that Mafo pretreatment markedly and selectively inhibits suppressor cells that limit long-term expansion of splenic CTL in culture and inhibit adoptive immunotherapy of solid tumors.This work was supported by grants CA 42443, CA 48075 and T32-CA 09210 from the National Cancer Institute, Department of Health and Human Services, in part by PHS AI-25044, an American Cancer Society Clinical Oncology Career Development Award (H. D. B.) and by a Medical Scholar's Award from the A. D. Williams Foundation (T. H. I.) 相似文献
837.
Teruyuki Nakanishi 《Environmental Biology of Fishes》1991,30(1-2):135-146
Synopsis The ontogenetic development of the immune system in a marine teleostSebastiscus marmoratus was studied by histological examination and removal of the thymus. The pronephros and the spleen had been differentiated
at the time of birth and contained small numbers of haemopoietic cells. In contrast to most vertebrates, the rudiments of
the thymus were first visible 1 week post-birth in the dorsoposterior part of the pharynx, the same location as in the adults.
However, small lymphocytes first appeared in the thymus of fish at 3 weeks of age, followed by the pronephros at 4 weeks and
the spleen at 6 weeks. Complete or partial suppression of the antibody response to sheep red blood cells (SRBC) occurred in
fish that were thymectomized at 1.5 months of age and immunized 2 weeks later, and a marked decrease in lymphocytes was observed
in the pronephros and spleen. The thymectomy of adult fish also caused reduced serum antibody titres in fish immunized 1 month
after the operation. These results suggest that the thymus plays an essential role in the development of the immune system
and its functions continue into adult life. 相似文献
838.
Kazunori Takano Akihiro Takemura Mitsuru Furihata Teruyuki Nakanishi Akihiko Hara 《Environmental Biology of Fishes》1991,30(1-2):39-48
Synopsis Changes in serum steroid hormones were studied during the reproductive cycle of a viviparous rockfish,Sebastiscus marmoratus. Serum levels of estradiol-17β (E2) and testosterone (T) were moderately high throughout the spawning period from December until February (E2), and until post-spawning in April (T). Serum progesterone (prog) fluctuated but remained low throughout the annual reproductive
cycle; 17α,20β-dihydroxy-4-pregnen-3-one (17α, 20β-diOHprog), on the other hand, was relatively high during the spawning period.
During the spawning period, 7 of 12 females reared under laboratory conditions spawned twice at 10-to 16-day intervals. Histological
observations indicated that oocytes developed gradually during gestation of the preceding brood and; after parturition, developed
more quickly towards the end of vitellogenesis and subsequent fertilization. In repeat spawners, E2 and female-specific serum proteins remained high several days after the first parturition, then gradually decreased. Prog
showed no significant changes over the period. The 17α, 20β-diOHprog, however, was low immediately after parturition, then
rapidly increased, remained elevated during the middle of the period and then decreased. These results indicate that E2 is involved in vitellogenesis, and 17α, 20β-diOHprog may have some important roles in gestation in the multiple spawnerS. marmoratus. 相似文献
839.
A Nakao T Imamura S Souchelnytskyi M Kawabata A Ishisaki E Oeda K Tamaki J Hanai C H Heldin K Miyazono P ten Dijke 《The EMBO journal》1997,16(17):5353-5362
840.
Keiichi Kawabata 《Ecological Research》1995,10(2):207-215
Eodiaptomus japonicus was collected in the north basin of Lake Biwa, Japan, on six dates from 11 to 25 June 1987. Temporal changes in its vertical
distribution and reproduction indices were small, but those in its abundance were large. Mortality was high in the naupliar
stage I and from copepodid stage III to adult stage. The latter fact and low proportion of females in adulthood suggest heavy
predation by fishes which prefer larger prey.Eodiaptomus japonicus showed ontogenetic vertical migration within the epilimnion. The direction of the migration was upward in the early naupliar
stages and downward in the late naupliar and early copepodid stages. Both migrations resulted in raising mortality in the
corresponding or succeeding stages, probably expressing the behavioral constraints ofE. japonicus. 相似文献