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81.
The roles of ultraviolet-B (UV) radiation in the immunogenicity of human cancer cells have not been fully studied. We have investigated the effects of UV radiation on metastatic melanoma and renal cell carcinoma cells with regard to MHC antigen expression and the ability to induce cytotoxic T lymphocyte (CTL) activity in peripheral blood mononuclear cells (PBMC) or tumor-infiltrating lymphocytes (TIL) against untreated autologous tumor cells. UV radiation respectively decreased or increased MHC class I expression of freshly isolated tumor cells or cultured tumor cells, and also decreased MHC class I expression of starved cultured tumor cells. It increased the ability of both freshly isolated and cultured tumor cells to induce CTL activity from PBMC against untreated autologous tumor cells. UV-irradiated subclones that were more susceptible to CTL lysis were more potent for CTL induction from TIL than either an untreated parental clone or a UV-irradiated subclone that was resistant to CTL lysis. In summary, UV radiation increased the ability of tumor cells to induce CTL activity without a corresponding effect on MHC antigen expression.This work was supported in part by a grant CA47891 from the National Cancer Institute, USA, a grant-in-aid of the comprehensive 10-years strategy for cancer control from ministry of a Health and Welfare, Japan, and the Ishibashi Research Fund, Japan  相似文献   
82.
辽宁和江苏两省杂草稻植物性状多样性   总被引:6,自引:0,他引:6  
辽宁和江苏两省是我国杂草稻(Oryza sativa f. spontanea)发生最为严重的地区之一, 为明确两省杂草稻识别特征和类型, 我们在两省14个市29个样点采集样品, 与当地栽培水稻品种一并在南京种植, 观测了营养生长期和生殖生长期的23个植物性状。结果表明, 两省杂草稻在营养生长期的1月株高、1月和2月分蘖数, 在生殖生长期的果皮色、谷粒长/宽比、百粒重、落粒性、秆硬度、剑叶宽、剑叶长、有效穗数、50%黄熟、50%黄熟–50%抽穗和全黄熟等性状与相应的当地栽培稻存在差异;主成分1和主成分2组成的二维散点图(累计贡献率达43.24%)也显示出两省杂草稻间以及与栽培稻间的差异性。采用欧氏距离对两省杂草稻进行系统聚类可以将杂草稻分为籼型和粳型。其中辽宁省杂草稻全部聚在粳型类群中, 它们又可细分为两类; 江苏省杂草稻既有粳型, 又有籼型, 其中粳型与辽宁省杂草稻聚在粳型类群中, 籼型又可分为3类。这6个类群分别具有如下突出特点: 第1类为强落粒、粒轻、秆矮、早熟、偏粳等; 第2类为无芒、穗多、强休眠、剑叶窄、偏粳等; 第3类为长芒、弱分蘖、穗少、弱落粒、偏粳等; 第4类为硬秆、剑叶宽、迟熟、强休眠、偏籼等; 第5类为红果皮、粒长、软秆、粒重、偏籼等; 第6类为无芒、株高、穗长、剑叶长、偏籼等。上述杂草稻的形态学指标和类型的研究将为两省开展杂草稻危害防治工作提供理论依据。  相似文献   
83.
84.
Dai D  Xia L 《Biotechnology progress》2005,21(4):1165-1168
Alkaline lipase production was performed in submerged fermentation by Penicillium expansum PED-03. It was found that the suitable carbon source and nitrogen source for lipase production were 0.5% starch and 4.0% soybean meal, respectively. The maximal lipase activity (850 U/mL) of production was achieved at initial pH 5.5-6.0, 26 degrees C, 72 h. Tween-80 was an effective enhancer for lipase production. Agitation speed of the fermentor played an important role, and the suitable agitation speed for lipase production was 500 r/min. The lipase was stable within the range of pH 7.0-10.0 and 20-40 degrees C, and the optimum conditions for the enzymatic reaction were 35 degrees C and pH 9.5. The enzymatic resolution of racemic allethrolone (4-hydroxy-3-methyl-2-(2-propenyl)-2- cyclopenten-1-one) was carried out by the lipase from P. expansum PED-03, and the conversion reached 48% with excellent enantioselectivity (E > 100), which showed a good application potential in the production of optically pure allethrolone.  相似文献   
85.
胰腺是一个重要的内外分泌混合腺, 胰腺发生损伤后能够再生。为了探讨胰腺活体细胞世系追踪的方法和胰腺损伤后再生细胞的来源,分别通过胰腺伤口涂抹并胰内注射、尾静脉注射及腹腔注射三种方法, 利用假型反转录病毒对成体小鼠大部分切除后胰腺的细胞进行世系追踪。结果发现在活体条件下, 与尾静脉注射及腹腔注射法相比, 胰腺伤口涂抹并胰腺内注射反转录病毒的方法能够更有效的标记胰腺细胞; 而且, 通过对标记细胞的世系追踪研究证明, 在胰腺损伤后, 胰腺腺泡细胞能够接受损伤信号刺激发生再生。为今后进一步利用反转录假病毒对活体胰腺进行细胞命运追踪研究奠定基础, 为利用反转录病毒载体进行胰腺疾病的基因治疗提供线索。  相似文献   
86.
李劲亭  刘力  戴欣 《微生物学报》2012,52(10):1181-1186
人和动物胃肠道中都栖息了大量的产丁酸微生物。研究表明,参与丁酸合成中心途径的酶基因成簇存在,其相关基因的排列形式多样并具有属种特异性。参与丁酸合成最后一步的(丁酰辅酶A/乙酸)辅酶A(CoA)转移酶在胃肠道产丁酸微生物中广泛存在,并在丁酸合成中发挥重要作用。本文结合我们的研究工作,综述了国内外丁酸合成相关酶基因和基因簇的最新研究进展。  相似文献   
87.
The MADS-box gene SOC1/TM3 (SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1/ Tomato MADS-box gene 3) is a main integrator in the Arabidopsis flowering pathway; its structure and function are highly conserved in many plant species. SOC1-like genes have been isolated in chrysanthemum, one of the most well-known ornamental plants, but it has not been well characterized thus far. We isolated and characterized ClSOC1-1 and ClSOC1-2, two putative orthologs of Arabidopsis SOC1, from the wild diploid chrysanthemum, Chrysanthemum lavandulifolium, to investigate the regulatory mechanisms of flowering time control in chrysanthemum. Expression analysis indicated that ClSOC1-1 and ClSOC1-2 were expressed in all examined organs/tissues (leaves, shoot apices, petioles, stems and roots) with different expression levels, and with high expression in the shoot apices and leaves during the early stage of floral transition. The expression levels of ClSOC1-1 and ClSOC1-2 in the shoot apices increased at different developmental stages with the highest expression levels after 7 days of short-day treatment. Overexpression of ClSOC1-1 and ClSOC1-2 in wild-type Arabidopsis resulted in early flowering, which was coupled with the upregulation of one of the flowering promoter genes LEAFY. Our results suggested that the ClSOC1-1 and ClSOC1-2 genes play an evolutionarily conserved role in promoting flowering in Chrysanthemum lavandulifolium and could serve as a vital target for the genetic manipulation of flowering time in the chrysanthemum.  相似文献   
88.
中国菊属一些种的分支分类学研究   总被引:13,自引:0,他引:13  
运用分支分析方法研究了12种原产中国的野生菊属植物的系统发育关系,并引入了若干栽培品种及部分杂种一代植株作为分析材料。研究结果表明:分支分析方法有效而准确地将分类群分类,并揭示出毛华菊(Dendranthemarestitum)与菊花(Dendranthema×gran-diflorum)同为菊属植物中进化程度较高的种,部分种间杂种也已进入栽培类群。同时还发现不同性状在各品种间平行进化的现象。根据上述结果,作者讨论了中国菊属植物的系统进化及菊花起源问题。  相似文献   
89.
Schistosomiasis is a serious and widespread parasitic disease caused by infection with Schistosoma. Because the parasite’s eggs are primarily responsible for schistosomiasis dissemination and pathogenesis, inhibiting egg production is a potential approach to control the spread and severity of the disease. The bromodomain and extra-terminal (BET) proteins represent promising targets for the development of epigenetic drugs against Schistosoma. JQ-1 is a selective inhibitor of the BET protein family. In the present study, JQ-1 was applied to S. japonicum in vitro. By using laser confocal scanning microscopy and EdU incorporation assays, we showed that application of JQ-1 to worms in vitro affected egg laying and the development of both the male and female reproductive systems. JQ-1 also inhibited the expression of the reproductive-related genes SjPlk1 and SjNanos1 in S. japonicum. Mice infected with S. japonicum were treated with JQ-1 during egg granuloma formation. JQ-1 treatment significantly reduced the size of the liver granulomas and levels of serum alanine aminotransferase and aspartate aminotransferase in mice and suppressed both egg laying and the development of male and female S. japonicum reproductive systems in vivo. Moreover, the mRNA expression levels of some proinflammatory cytokines were decreased in the parasites. Our findings suggest that JQ-1 treatment attenuates S. japonicum egg–induced hepatic granuloma due at least in part to suppressing the development of the reproductive system and egg production of S. japonicum. These findings further suggest that JQ-1 or other BET inhibitors warrant additional study as a new approach for the treatment or prevention of schistosomiasis.  相似文献   
90.
Tropical lotus (Nelumbo) is an important and unique ecological type of lotus germplasm. Understanding the genetic relationship and diversity of the tropical lotus is necessary for its sustainable conservation and utilization. Using 42 EST-SSR (expressed sequence tag-simple sequence repeats) and 30 SRAP (sequence-related amplified polymorphism) markers, we assessed the genetic diversity and inferred the ancestry of representative tropical lotus from Thailand and Vietnam. In total, 164 and 41 polymorphic bands were detected in 69 accessions by 36 EST-SSR and seven SRAP makers, respectively. Higher genetic diversity was revealed in Thai lotus than in Vietnamese lotus. A Neighbor-Joining tree of five main clusters was constructed using combined EST-SSR and SRAP markers. Cluster I included 17 accessions of Thai lotus; cluster II contained three Thai accessions and 11 accessions from southern Vietnam; and cluster III was constituted by 13 accessions of seed lotus. Consistent with the results from the Neighbor-Joining tree, the genetic structure analysis showed that the genetic background of most Thai and Vietnamese lotus was pure, as artificial breeding has been rare in both countries. Furthermore, these analyses indicate that Thai and Vietnamese lotus germplasms belong to two different gene pools or populations. Most lotus accessions are genetically related to geographical distribution patterns in Thailand or Vietnam. Our findings showed that the origin or genetic relationships of some unidentified lotus sources can be evaluated by comparing morphological characteristics and the data of molecular markers. In addition, these findings provide reliable information for the targeted conservation of tropical lotus and parent selection in breeding novel cultivars of lotus.  相似文献   
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