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Metastasis formation is a major clinical problem in cancer treatment, and no significant progress in the treatment of metastatic spread has been made. This apparent lack of progress is partly caused by the absence of clinically relevant animal models of meta stases. The binding of the lectin Helix pomatia agglutinin (HPA) has been associated with a poor prognosis in breast and colon cancer patients. HPA-positive and -negative human breast and colon cancer cell lines were transplanted into severe combined immunodeficient (SCID) mice. HPA-positive breast cancer cell lines (MCF-7 and T47D) metastasized in SCID mice, whereas the HPA-negative ones (BT20, HS578T and HBL100) did not. The HPA-positive colon cancer cell line HT29 metastasized, while the HPA-negative ones (COLO320DM, SW480 and SW620) did not. However, in two of eight SCID mice inoculated with the HPA-negative colon cancer cell line, CACO2 metastatic deposits were found. Despite this exception, HPA binding is a good indicator of the metastasis of human breast and colon cancer cells in SCID mice: 23 out of 26 HPA-positive cancers metastasized, as opposed to only two out of 38 HPA-negative cancers. This experimental model is well suited for investigating the functional role of carbohydrate residues recognized by HPA in breast and colon cancer metastasis. This revised version was published online in November 2006 with corrections to the Cover Date.  相似文献   
133.
Thirty strains of Yersinia pseudotuberculosis were isolated from rabbits (17 strains), wild rats (9 strains) and house rats (4 strains) in China between 1990 and 1993. The biochemical properties of these isolates were identical with those of Y. pseudotuberculosis and no special characteristics were found in these strains. Serologically, serogroups 4b and 5b were identical to isolates found in Japan, and a new serogroup 1c and unclassified strains have also been detected. The existence of virulence-associated properties were different among strains. The pYV plasmid was detected from 6 strains of 30 isolates. This report documents the presence of Y. pseudotuberculosis in China, providing important epidemiological information.  相似文献   
134.
The efficacy of systemic infusion of recombinant human macrophage-colony-stimulating factor (M-CSF) in combination with local treatment with human recombinant tumor necrosis factor (TNF) and mouse recombinant interferon (IFN) was studied in vivo on a subclone of B16 melanoma (MmB16) in mice. Short-term intravenous administration of M-CSF at a dose of 106 units daily had no antitumor effect in vivo. Similarly, local treatment of tumor with TNF (5 g daily) did not produce any therapeutic effect. However, simultaneous administration of the same dose of TNF with IFN (1000 units daily) resulted in a synergistic effects manifested by the retardation of tumor growth. Addition of systemic infusion of M-CSF to the local therapy with TNF and IFN induced further augmentation of antitumor efficacy and delayed progression of MmB16 melanoma. The strengthened antitumor effect of combination therapy including M-CSF, TNF and IFN was most probably due to the increased release of monocytes from the bone marrow, their recruitment into the site of tumor growth and subsequent local stimulation of their antitumor activity.  相似文献   
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We have investigated heat-shock response in a marine bacterium Vibrio harveyi. We have found that 39 C was the highest tempature at which V. harveyi was able to grow steadily. A shift from 30° C to 39° C caused increased synthesis of at least 10 proteins, as judged by SDS-PAGE, with molecular masses of 90, 70, 58, 41, 31, 27, 22, 15, 14.5 and 14kDa. The 70, 58, 41 and 14.5 kDa proteins were immunologically homologous to DnaK, GroEL, DnaJ and GroES heat-shock proteins of Escherichia coli, respectively. V. harveyi GroES protein had a lower molecular mass (14.5 kDa) than E. coli GroES, migrating in SDS-PAGE as 15 kDa protein. We showed that a protein of ~43 kDa, immunologically reactive with antiserum against E. coli sigma 32 subunit (σ32) of RNA polymerase, was induced by heat-shock and co-purified with V. harveyi RNA polymerase. These results suggest that the 43 kDa protein is a heat-shock sigma protein of V. harveyi. Preparation containing the V. harveyi sigma 32 homologue, supplemented with core RNA polymerase of E. coli, was able to transcribe heat-shock promoters of E. coli in vitro.  相似文献   
137.
四川地区幼儿和学龄前儿童的鼻部测量   总被引:2,自引:0,他引:2  
史铀  邓德华 《人类学学报》1995,14(2):151-156
本文报告1116例四川地区幼儿和学龄前儿童(2-7岁)鼻部9项指标的测量均数,性差及年龄发育特点。性差:仅鼻凹鼻底距4-6.5岁等少数指标部分年龄段男女性间出现显著性划异(男>女)。此外各项指标的绝大多数年龄段男女性间无显著性差异。年龄发育:9项测量指标中7项的生长曲线随年产长而上升,数值随年龄增大,并有1-2个发育高峰;提示鼻部发育具有阶段性;2项指标的曲线随年龄增长变化较小。4项指标男女性的曲  相似文献   
138.
合成了2-氯-5-正十二硫烷基-6-甲基-4,7-苯并噻唑醌(2-Cl-DMMDBT)和2-氯-5-正丁烷氨基-6-甲基-4,7-苯并噻唑醌(2-Cl-BAMDBT)两种化合物,研究了它们对线粒体呼吸链酶系的抑制作用.结果表明:2-Cl-DMMDBT和2-C1-BAMDBT对琥珀酸氧化酶及泛醌氧化酶的电子传递活性均表现一定的抑制作用,而对细胞色素氧化酶无作用,说明二者的抑制作用发生在泛醌反应区.二者对NADH氧化酶的抑制行为略有不同,2-Cl-DMMDBT是一个逐渐加强的过程,最终可致酶活性完全抑制,而2-Cl-BAMDBT则表现为瞬间抑制.比较了2-Cl-DMMDBT和2-Cl-BAMDBT对琥珀酸氧化酶的抑制能力,长侧链的2-Cl-DMMDBT比短侧链的2-Cl-BAMDBT抑制能力强很多.  相似文献   
139.
科尔沁沙质草甸草场不同牧压条件植物群落分异数量分析   总被引:5,自引:0,他引:5  
本文用TWINSPAN分类和PCA及DCA排序技术分析了沙质草甸草场放牧试验引起地植物群落分异的特征,主要结论为:放牧强度是引起群落分异的主要原因,群落的分异主要表现在高度和现存生物量上。放牧引起群落变化的动力主要是放牧强度。而无牧条件下群落变化的主要动力是植物间的相互作用。当地的放牧强度处于中牧与重牧之间,属于过度放牧。这是引起草场退化及沙漠化的主要原因之一。  相似文献   
140.
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