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71.
Liver biopsy is still most commonly done via the percutaneous route; however, increasingly, transvascular venous liver biopsy has been used in patients with bleeding disorders. Although the jugular route is now generally favoured, a transfemoral route can be a useful alternative technique when the jugular route is not available. We describe the transfemoral technique and outline a number of commonly encountered problems and complications and suggested methods of addressing them.  相似文献   
72.
SoxE genes (Sox8, Sox9, and Sox10) are early response genes to neural crest induction. Although the early role of Sox9 has been examined in chick and frog, later roles in neural crest migration and differentiation remain largely unexplored. We first examined which SoxE genes were expressed in trunk neural crest cells and then investigated their function using in ovo electroporation. The results of this analysis reveal that Sox10 is present in migrating neural crest cells, whereas other SoxE genes are only expressed transiently after induction. Ectopic expression of Sox10 in the neural tube at trunk level induced expression of HNK-1 in neuroepithelial cells followed by extensive emigration from all levels of the dorsoventral neuraxis, including the floor plate. Sox10-expressing cells failed to express neuronal, Schwann, or melanocyte markers up to 6 days posttransfection (E8), suggesting these cells were maintained in an undifferentiated state. Overexpression of Sox8 or Sox9 had similar but not identical effects on neuroepithelial cells. These results show that high levels of Sox10, Sox9, or Sox8 expression in the neural tube are capable of inducing a migratory neural crest-like phenotype even in the absence of dorsal signals and can maintain these cells in an undifferentiated state.  相似文献   
73.

Background and purpose:

P2Y nucleotide receptors are involved in the regulation of vascular tone, smooth muscle cell (SMC) proliferation and inflammatory responses. The present study investigated whether they are involved in atherosclerosis.

Experimental approach:

mRNA of P2Y receptors was quantified (RT-PCR) in atherosclerotic and plaque-free aorta segments of apolipoprotein E-deficient (apoE–/–) mice. Macrophage activation was assessed in J774 macrophages, and effects of non-selective purinoceptor antagonists on atherosclerosis were evaluated in cholesterol-fed apoE–/– mice.

Key results:

P2Y6 receptor mRNA was consistently elevated in segments with atherosclerosis, whereas P2Y2 receptor expression remained unchanged. Expression of P2Y1 or P2Y4 receptor mRNA was low or undetectable, and not influenced by atherosclerosis. P2Y6 mRNA expression was higher in cultured J774 macrophages than in cultured aortic SMCs. Furthermore, immunohistochemical staining of plaques demonstrated P2Y6-positive macrophages, but few SMCs, suggesting that macrophage recruitment accounted for the increase in P2Y6 receptor mRNA during atherosclerosis. In contrast to ATP, the P2Y6-selective agonist UDP increased mRNA expression and activity of inducible nitric oxide synthase and interleukin-6 in J774 macrophages; this effect was blocked by suramin (100–300 µM) or pyridoxal-phosphate-6-azophenyl-2′-4′-disulphonic acid (PPADS, 10–30 µM). Finally, 4-week treatment of cholesterol-fed apoE–/– mice with suramin or PPADS (50 and 25 mg·kg−1·day−1 respectively) reduced plaque size, without changing plaque composition (relative SMC and macrophage content) or cell replication.

Conclusions and implications:

These results suggest involvement of nucleotide receptors, particularly P2Y6 receptors, during atherosclerosis, and warrant further research with selective purinoceptor antagonists or P2Y6 receptor-deficient mice.  相似文献   
74.
缬昔洛韦的合成   总被引:1,自引:0,他引:1  
目的;对缬昔洛韦的合成进行了研究。方法:以阿昔洛韦和N-苄氧羰基-L-缬氨酸为原料,经酰化,催化氢解反应得到了新型抗疱疹毒药物缬昔洛韦。结果;本品的元素分析,红外,质谱及核磁共振图谱数据与文献报道一致,总收率为45.2%,结论;采用此法合成缬昔洛韦是可行的,适合于工业生产。  相似文献   
75.
给大鼠腹腔及睾内注射氚标记的( )与(-)棉酚后第7、18天,对主要脏器中各亚细胞组分的总放射活性及共价结合的放射活性进行了动态观察。结果表明,(-)棉酚在心肌线粒体共价结合放射活性较明显高于( )棉酚;( )及(-)棉酚在睾丸细胞膜、微粒体共价结合的放射活性随时间增高,且(-)棉酚较为明显。  相似文献   
76.
给大鼠腹腔及睾内注射氚标记的(+)与(-)棉酚后第7、18天,对主要脏器中各亚细胞组分的总放射活性及共价结合的放射活性进行了动态观察。结果表明,(-)棉酚在心肌线粒体共价结合放射活性较明显高于(+)棉酚;(+)及(-)棉酚在睾丸细胞膜、微粒体共价结合的放射活性随时间增高,且(-)棉酚较为明显。  相似文献   
77.
一个计量型制剂含量均匀度检查新方案的制订与评价   总被引:2,自引:0,他引:2  
采用概率统计计算方法找到符台一定质量要求的制剂批单剂含量总体均值和标准差的轨迹,进行近似并确定了二次抽样范围,从而制订出一个以标示量为参考值、二次抽样的计量型含量均匀度检查新方案;然后用蒙特卡洛即统计模拟方法为该方案在4个不同允许废品率下绘制抽样特性(OC)曲线,同时统计平均样本容量,并与几个国家药典典型的含量均匀度检查法的对应指标比较;最后讨论了新方案的准确性、灵活性和在控制生产上的实用性等问题。  相似文献   
78.
Dietary energy restriction was previously shown to be effective in preventing a wide range of experimentally induced cancers. Studies were conducted to assess the influence on pancreatic carcinogenesis of dietary energy restrictions (reduced fat and carbohydrate) of 10%, 20% or 40% in comparison with control in Syrian hamsters treated with N- nitrosobis(2-oxopropyl)amine (BOP). Two carcinogenesis studies were conducted. One used a single treatment with 20 mg BOP/kg body weight and followed hamsters for 102 weeks following treatment, and the other used three weekly treatments of 20 mg BOP/kg body weight and followed hamsters for 45 weeks after treatment. Hamsters were fed control or energy restricted diet beginning the week following the last BOP treatment. Pancreatic carcinomas were induced in 9-18% of the hamsters in the first experiment and in 59-66% of the animals in the second. Dietary energy restriction did not influence carcinoma incidence in either study, and in the second experiment the multiplicity of tumors was higher in the 40% energy restriction (ER) group than in control hamsters. Plasma corticosterone was suppressed by BOP treatment, particularly in the 20% and 40% ER hamsters in the second experiment, and diet or BOP treatment did not significantly alter plasma cortisol. Pancreatic protein kinase Czeta measured by Western blot was highest in the cytosol and particulate fractions of the 40% ER hamsters in the first experiment. These results indicate that dietary energy restriction is not effective in the prevention of BOP induced pancreatic carcinogenesis in the Syrian hamster.   相似文献   
79.
新型全固态阿托品电极的研制   总被引:2,自引:0,他引:2  
制备了以脲醛树脂为框架,以KCl粉末为活性组分的Ag/AgCl固体电极。以此固体电极为基体,以阿托品—四苯硼酸根离子缔合物为活性物质,研制了一种新型全固态阿托品选择电极。并对此电极的性质进行了研究,结果表明该电极稳定性较好,并能用于硫酸阿托品制剂的含量测定。  相似文献   
80.

Background

Semaphorins act as chemotactic cues for cell movement via their transmembrane receptors, plexins. Somatic missense mutations in the plexinB1 gene coupled with overexpression of the protein frequently occur in prostate tumours, indicating a role for plexinB1 in the pathogenesis of prostate cancer.

Results

Two specific mutations found in prostate cancer enhance RhoD binding and one other mutation results in loss of inhibition of Rac-dependent Pak1 phosphorylation and lamellipodia formation and in impairment of trafficking of plexinB1 to the membrane. None of the three characterised mutations affect PDZRhoGEF binding, RhoA activity, the interaction of plexinB1with the oncogenes ErbB2 or c-Met or ErbB2 phosphorylation. The mutations have the net effect of increasing cell motility by blocking plexinB1-mediated inhibition of Rac while enhancing the interaction with RhoD, an anti-migratory factor.

Conclusions

PlexinB1 mutations block plexinB1-mediated signalling pathways that inhibit cell motility.  相似文献   
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