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11.
荔枝草提取工艺的实验研究 总被引:1,自引:0,他引:1
目的:寻找荔枝草最佳提取工艺。方法:采用正交试验法,以溶剂用量、浸泡时间、提取次数、醇沉浓度和醇沉时间六因素,每个因素选取三水平进行实验。结果:因素A和D对提取有显著影响。因此C、B、E和F则有一定影响。结论:煎煮的最佳提取工艺是A3B1C2D3E3F3。 相似文献
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高效液相色谱法测定车前草中桃叶珊瑚苷的含量 总被引:10,自引:1,他引:10
目的建立测定车前草中桃叶珊瑚苷含量的高效液相色谱法。方法以Nucleosi17-C 相似文献
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de Vries-Bouwstra JK Goekoop-Ruiterman YP Verpoort KN Schreuder GM Ewals JA Terwiel JP Ronday HK Kerstens PJ Toes RE de Vries RR Breedveld FC Dijkmans BA Huizinga TW Allaart CF 《Arthritis and rheumatism》2008,58(5):1293-1298
OBJECTIVE: To determine the association of HLA-DRB1, rheumatoid factor (RF), and anti-citrullinated protein antibody (ACPA) status with progression of joint damage in early rheumatoid arthritis (RA) treated according to different treatment strategies. METHODS: The present study was conducted using data from the BeSt study (Behandelstrategie?n voor Reumatoide Artritis [treatment strategies for rheumatoid arthritis]), a randomized trial comparing 4 targeted (toward achievement of a Disease Activity Score [DAS] of < or =2.4) treatment strategies: sequential monotherapy (group 1), step-up combination therapy (group 2), initial combination therapy with methotrexate, sulfasalazine, and prednisone (group 3), and initial combination therapy with methotrexate and infliximab (group 4), in 508 patients with early RA. Multivariate logistic regression analysis was used to predict progressive disease (increase of Sharp/van der Heijde score over 2 years beyond the smallest detectable change [4.6]) according to the presence or absence of the shared epitope (SE), DERAA, RF, and ACPA, with correction for other baseline characteristics. RESULTS: Progressive disease could not be predicted by presence of the SE: the odds ratio in groups 1, 2, 3, and 4, respectively, was 1.4, 2.6, 1.9, and 3.0. DERAA carriership did not protect against progressive disease (odds ratio 0.4, 1.4, 0.9, and 0.9 in groups 1, 2, 3, and 4, respectively). RF positivity and ACPA positivity predicted progressive disease in group 1 (odds ratio 4.7 [95% confidence interval 1.5-14.5] for RF and 12.6 [95% confidence interval 3.0-51.9] for ACPA), but not in groups 2-4 (for RF, odds ratio [95% confidence interval] 1.5 [0.5-4.9], 1.0 [0.3-3.3], and 1.4 [0.4-4.8] in group 2, group 3, and group 4, respectively; for ACPA, odds ratio [95% confidence interval] 3.4 [0.8-14.2], 1.7 [0.5-5.4], and 1.8 [0.5-6.8] in group 2, group 3, and group 4). CONCLUSION: In patients with early RA treated with the goal of tight control of the DAS, no significant association between HLA-DRB1 status and radiographic progression was found. RF and ACPA were predictive of progressive disease only in patients treated with sequential monotherapy. These observations suggest that effective treatment can prevent radiographic progression, even in patients with risk factors for severe damage. 相似文献
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三叶因子与胃黏膜保护的研究进展 总被引:1,自引:0,他引:1
三叶因子家族是一群主要由胃肠道黏液细胞分泌的小分子多肽.其共同特征为均含一特殊的P结构域及三叶状结构.这种稳定的结构使三叶因子家族具有明显的抗蛋白酶水解、酸消化及耐热特性,因而能在消化道复杂的环境中保持生物活性.目前在哺乳动物体内发现的有pS2/TFF1、SP/TFF2和ITF/TFF3三种,它们具有黏膜保护与修复、肿瘤抑制、信号传导、调节细胞凋亡等功能.本文阐述了三叶因子家族发现的历史,并初步探讨了其作用.同时也对三叶因子受体这一热点的研究现状进行总结. 相似文献
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We have recently described a flow cytometry technique, whose sensitivity allows direct measurements of latent times before the onset of aggregation, and of rates, maximal extents, and reversibility of aggregation (J Leuk Biol 50:434, 1991). We report here that activators which stimulate sustained cellular signaling associated with increases in intracellular calcium (ionomycin) or protein kinase C activation (phorbol myristate acetate, PMA) cause complete (> or = 98%) and irreversible neutrophil aggregation, with latent times for the onset of aggregation inversely proportional to the activator concentration. In contrast, the receptor-specific activators leukotriene B4 (LTB4), formyl peptide FMLP, and platelet-activating factor (PAF) gave only partial and reversible aggregatory responses, limited by the following similar properties: latent times of 4.5 seconds +/- 1.5 seconds, independent of activator concentration; similar concentrations for onset of aggregation (approximately 1 nmol/L) that increased over a similar broad range of activator concentration, with one-half maximal rates of aggregation at 10 nmol/L to 30 nmol/L, corresponding to reported dissociation constant values; comparable limited recruitment and spontaneous reversibility of aggregation; absence of interactivator synergism; and similar exponential decays in activated cell stickiness (refractoriness), with t1/2 = 15 to 30 seconds. Variable cross- desensitization was seen between LTB4 and FMLP depending on donor and activator concentrations. In vivo, these properties are expected to provide localization of the aggregatory response, minimizing the otherwise detrimental effects of circulating activated neutrophils. 相似文献
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We have recently found that antibodies to L-selectin, the homing receptor on neutrophils, are as effective as those to beta 2-integrin at blocking formyl peptide-stimulated aggregation. Therefore, we investigated the requirements for expression of L-selectin and beta 2- integrin on adjacent cells during aggregation. Fluorescence flow cytometry allowed characterization of aggregates on the basis of size and color, as well as antibody binding to these two adhesive molecules. Formyl peptide-stimulated aggregate formation was measured for individual populations fluorescently labeled red (LDS-751) or green (CD44-FITC), and interpopulation red-green cell conjugates. Blocking either the beta 2-integrin or L-selectin adhesive epitope with monoclonal antibody on individual cell populations resulted in an approximately 50% reduction in two-color aggregation as compared with that in unblocked samples. Shedding the L-selectin on a cell population by preincubation with complexes of lipopolysaccharide and its plasma membrane binding protein also decreased aggregation to a control population by approximately 50%. We examined the aggregation of neutrophils from patients genetically deficient in beta 2-integrin and clinically leukocyte adhesion deficient (LAD). LAD adhesion to normal neutrophils was dependent on the expression of L-selectin on LAD cells and beta 2-integrin on normal cells. Thus, the minimum requirement for adhesion between two mixed populations of neutrophils was that one population expressed the beta 2-integrin and the other expressed the L- selectin adhesive epitope. 相似文献
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用放射性同位素的方法研究了丁基苯肽(NBP)在大鼠体内代谢,并对代谢产物进行了鉴定。结果表明,大鼠ig3HNBP后24h,从尿和粪中排出的放射性分别为ig剂量的552%和185%,排除了药物蓄积在体内的可能性;用高效液相色谱法分离、纯化了丁基苯酞的两个主要的体外代谢产物代I和代I,根据代I和代II的波谱数据(UV,1HNMR,MS)确定了它们的化学结构;薄层色谱(TLC)证明丁基苯酞的体内代谢产物同样有代I和代I,并且也是两个主要的代谢产物;大鼠ig3HNBP后1h,脑中原型药与代谢物的比例为1∶1,而且只发现有代I,未发现有代I,推测代I很有可能是活性代谢产物。 相似文献
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YP Panayiotopoulos MD PhD S Padayachee PhD BSC ACE Colchester PhD FRCP PR Taylor MChir FRCS 《International journal of clinical practice》1997,51(6):375-377
In early series the majority of carotid endarterectomies were performed in patients with amaurosis fugax (AFx) or transient ischaemic attacks (TIAs) who were thought to have atheromatous ulcers of the carotid bifurcation or the internal carotid artery (ICA). The degree of stenosis was considered to be of secondary importance. We compared our own data with two British series undertaken in the early and late 80s/early 90s. This reflects the broadening of indications and the change of practice for carotid endarterectomy over the years, on the one hand towards including patients who are at greater risk of perioperative stroke (previous CVAs vs TIAs, crescendo TIAs and stroke in evolution), and on the other towards patients who have had no symptoms attributable to the carotid lesion (asymptomatic cases, combined carotid and cardiac procedures). 相似文献