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1.
Mitsuyasu Hasebe Rumiko Kofuji Motomi Ito Mikio Kato Kunio Iwatsuki Kunihiko Ueda 《Journal of plant research》1992,105(4):673-679
Partial nucleotide sequences of the large subunit of ribulose-1,5-bisphosphate carboxylase (rubisco) gene (1333 base pairs:
about 90% of the gene) from several seed plants were determined. Phylogenetic trees based on amino acid sequences were inferred
by using the neighbor joining and maximum likelihood methods. The results indicate (1) monophyly of gnetum group (Ephedra, Gnetum, Welwitschia), (2) monophyly of extant gymnosperms containing gnetum group, which contradicts the results of morphological data. 相似文献
2.
A cytological and reproductive study of the diploid and triploid agamosporousDryopteris pacifica was made to elucidate the origin of its infraspecific cytotypes. Some triploids produced 16 spore mother cells (SMCs) sometimes with n=41II+41I chromosomes, in addition to eight SMCs with n=123II, in each sporangium. In the former case the 16 SMCs usually underwent abnormal meiosis to give rise to some 50 spores, some of which were regular-shaped; in the latter the eight SMCs multiplied into 32 spores by normal meiosis. We found that spores from one of the triploid plants developed into either diploid or triploid gametophytes, which further apogamously produced diploid or triploid sporophytes, respectively. This novel mechanism of ploidy reduction is discussed in relation to the origin of diploid agamosporous ferns, the taxonomic complexity of the species, and the correlation of agamospory with polyploidy. The mechanism is also compared to that operating in agamospermous angiosperms. 相似文献
3.
Effects of cytokines on in vitro growth of tumor-infiltrating lymphocytes obtained from human primary and metastatic liver tumors 总被引:4,自引:0,他引:4
Yukihiro Shimizu Shunzaburo Iwatsuki Ronald B. Herberman Theresa L. Whiteside 《Cancer immunology, immunotherapy : CII》1991,32(5):280-288
Summary Tumor-infiltrating lymphocytes (TIL) were isolated from 22 human primary and metastatic liver tumors, and expanded in vitro in the presence of either interleukin-2 (IL-2, 100 U/ml) plus tumor necrosis factor (TNF, 1000 U/ml), IL-2 (1000 U/ml) plus IL-4 (1000 U/ml) or IL-2 (1000 U/ml) alone. TIL proliferated in culture in 20/22 cases. Among different cytokine combinations, TNF and IL-2 were most effective in promoting the outgrowth of CD3+ CD8+ T lymphocytes (mean ± SEM: 90%±5) in the cultures of TIL from primary liver tumors. Cytotoxicity against autologous tumor cells was demonstrated in all early cultures of TIL from primary liver cancers in the presence of IL-2 plus TNF. In contrast, cultures of TIL derived from colon cancer metastatic to liver had significantly lower levels of autotumor cytotoxicity and proportions of CD3+ CD8+ cells (40%±13) than those of TIL from primary liver tumors. The addition on day 0 of interferons ( or ) to TIL cultured in the presence of TNF and IL-2, significantly augmented cytotoxicity against autologous tumor. In contrast, incubation of TIL in the presence of IL-4 and IL-2 did not result in increased autotumor responses in the cultures of TIL from primary liver tumors. The expansion (-fold) of TIL (day 30) cultured in the presence of IL-2 alone compared to that in the presence of TNF and IL-2 was significantly greater for hepatocellular carcinoma (median, 280 vs 260) than for autologous peripheral blood lymphocytes (36 vs 27), cholangiocarcinoma (42 vs 51) or TIL from metastatic colon cancer (39 vs 30). Outgrowth of TIL in IL-2 plus TNF offers an opportunity for in vitro enrichment in cells with autotumor cytotoxicity in primary liver tumors. However, this cytokine combination was unable to promote and sustain growth of autotumor effectors from TIL in metastatic liver cancer.Supported by ACS grants IM27 077 and IM588 A (TLW) and Organ Transplant Program Project 1P01-CA-4744501 AZ 相似文献
4.
Chromoplast DNA was isolated from ripe-red tomato fruits, andits structure compared with that of chloroplast DNAs from maturegreen fruits and leaves. There was a good correspondence betweenthe structures analyzed by BamHI or EcoRI digestion and by hybridizationwith a probe for the gene of the ribulose 1,5-bisphosphate carboxylase/oxygenaselarge subunit.
1 Present address: Koryo International College, Nisshin, Aichi470-01, Japan. (Received November 5, 1984; Accepted February 6, 1985) 相似文献
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Mechanism of erythromycin-induced ermC mRNA stability in Bacillus subtilis. 总被引:10,自引:5,他引:5
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In Bacillus subtilis, the ermC gene encodes an mRNA that is unusually stable (40-min half-life) in the presence of erythromycin, an inducer of ermC gene expression. A requirement for this induced mRNA stability is a ribosome stalled in the ermC leader region. This property of ermC mRNA was used to study the decay of mRNA in B. subtilis. Using constructs in which the ribosome stall site was internal rather than at the 5' end of the message, we show that ribosome stalling provides stability to sequences downstream but not upstream of the ribosome stall site. Our results indicate that ermC mRNA is degraded by a ribonucleolytic activity that begins at the 5' end and degrades the message in a 5'-to-3' direction. 相似文献
8.
胀果甘草化学成分的研究(Ⅲ) 总被引:5,自引:0,他引:5
继前文工作,本文报道从胀果甘草(Glycyrrhiza inflata Bat)根及根茎用95%乙醇渗滤后的提取部分中获得的另外五个化合物的结构鉴定。经理化性质及波谱分析,分别鉴定为胡萝卜甙(Daucosterol)、甘草查尔酮甲(Licochalcone A)、β-谷甾醇(β-Sitosterol),异芒柄花甙(Isoononin)和4',7一二羟基黄酮(4',7-Dihydroxy-flavone)。其中胡萝卜甙和异芒柄花甙为首次从该植物中获得。药理实验表明,甘草查尔酮甲对H_2O_2诱异的溶血有极好的抑制作用(97.3%),但甘草甙在三个体外氧化体系中都没有明显的活性。 相似文献
9.
Hirohiko Iwatsuki Kazunobu Sasaki Masumi Suda Chikako Itano 《Histochemistry and cell biology》1995,104(4):277-286
Using lectin and colloidal iron (CI) stainings in combination with neuraminidase digestion, glycoconjugates on the surface of erythropoietic cells of the yolk sac and liver in fetal mice were examined. Fetal hepatic macrophages were capable of distinguishing between phagocytozed and non-phagocytozed erythroid elements as described in our previous study. Marked differences between these two elements could be ultrahistochemically detected on their cell surface. The phagocytozed elements, such as nuclei expelled from erythroblasts and degenerating primitive erythroblasts, faintly bound neuraminidase-sensitive CI, and neuraminidase digestion imparted a weak peanut agglutinin (PNA) binding. In contrast, erythroblasts at various maturation stages, erythrocytes and normal primitive erythroblasts heavily bound neuraminidase-sensitive CI, and neuraminidase digestion imparted a moderate PNA binding. No differences in binding of either concanavalin agglutinin,Ricinus communis agglutinin-I or PNA were noted between phagocytozed and non-phagocytozed erythroid elements. Desialylation appears to be one of the most important signs for the recognition mechanism of fetal macrophage phagocytosis. During maturation of hepatic erythroblasts, sialic acid changes its affinity forLimax flavus agglutinin from strong to weak, and soybean agglutinin binding sites disappear at the basophilic erythroblast stage. Glycoconjugates on polychromatophilic erythroblasts acquire similar compositions to those of erythrocytes. 相似文献
10.