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991.
冠脉结扎法制做大鼠心肌缺血模型 总被引:38,自引:3,他引:38
目的探讨大鼠心肌缺血动物模型的构建。方法缝扎大鼠冠脉左前降支,于左室前外侧壁形成缺血区域,约占左室壁面积的20%~50%。结果完成85例动物模型制作,存活74只,其中60只据术中所见、心电图、及病理检查证实有明确的心肌缺血,心功能下降。结论该方法制作简单可行,动物存活率满意;但模型欠稳定,需标本量较大以充分筛选。 相似文献
992.
Xiao L Ryan UM Graczyk TK Limor J Li L Kombert M Junge R Sulaiman IM Zhou L Arrowood MJ Koudela B Modrý D Lal AA 《Applied and environmental microbiology》2004,70(2):891-899
The genetic diversity of Cryptosporidium in reptiles was analyzed by PCR-restriction fragment length polymorphism and sequence analysis of the small subunit rRNA gene. A total of 123 samples were analyzed, of which 48 snake samples, 24 lizard samples, and 3 tortoise samples were positive for Cryptosporidium: Nine different types of Cryptosporidium were found, including Cryptosporidium serpentis, Cryptosporidium desert monitor genotype, Cryptosporidium muris, Cryptosporidium parvum bovine and mouse genotypes, one C. serpentis-like parasite in a lizard, two new Cryptosporidium spp. in snakes, and one new Cryptosporidium sp. in tortoises. C. serpentis and the desert monitor genotype were the most common parasites and were found in both snakes and lizards, whereas the C. muris and C. parvum parasites detected were probably the result of ingestion of infected rodents. Sequence and biologic characterizations indicated that the desert monitor genotype was Cryptosporidium saurophilum. Two host-adapted C. serpentis genotypes were found in snakes and lizards. 相似文献
993.
994.
动物孵化酶(hatching enzyme,HE)是早期胚胎在特定发育阶段由孵化腺细胞产生和分泌的,在动物早期胚胎孵化中具有关键性作用。孵化腺细胞(hatching gland cell,HGC)一般为单细胞腺体,是从胚胎发育到特定阶段(孵化前)出现、至胚胎孵出后的特定时期消失的一时性细胞(transient type ofcells)。完全分化的HGC内充满了低电子密度的酶原颗粒(孵化酶原颗粒),在鱼胚中的分布因物种而异。在大多数鱼中,HGC分布在胚体的外表面和/或卵黄囊中,一般为外胚层来源。如在虹蹲鱼HGC分布在胚体的前表面、卵黄囊、咽部、鳃的内表面及外表面,属于外胚层来源。而日本鳉鱼HGC 相似文献
995.
996.
Ling TY Chen CL Huang YH Liu IH Huang SS Huang JS 《The Journal of biological chemistry》2004,279(37):38736-38748
The type V TGF-beta receptor (TbetaR-V) plays an important role in growth inhibition by IGFBP-3 and TGF-beta in responsive cells. Unexpectedly, TbetaR-V was recently found to be identical to the LRP-1/alpha(2)M receptor; this has disclosed previously unreported growth regulatory functions of LRP-1. Here we demonstrate that, in addition to expressing LRP-1, all cells examined exhibit low affinity but high density acidic pH binding sites for LRP-1 growth regulatory ligands (TGF-beta(1), IGFBP-3, and alpha(2)M(*)). These sites, like LRP-1, are sensitive to receptor-associated protein and calcium depletion but, unlike LRP-1, are also sensitive to chondroitin sulfate and heparin and capable of directly binding ligands, which do not bind to LRP-1. Annexin VI has been identified as a major membrane-associated protein capable of directly binding alpha(2)M(*) at acidic pH. This is evidenced by: 1) structural and Western blot analyses of the protein purified from bovine liver plasma membranes by alpha(2)M(*) affinity column chromatography at acidic pH, and 2) dot blot analysis of the interaction of annexin VI and (125)I-alpha(2)M(*). Cell surface annexin VI is involved in (125)I-TGF-beta(1) and (125)I-alpha(2)M(*) binding to the acidic pH binding sites and (125)I-alpha(2)M(*) binding to LRP-1 at neutral pH as demonstrated by the sensitivity of cells to pretreatment with anti-annexin VI IgG. Cell surface annexin VI is also capable of mediating internalization and degradation of cell surface-bound (125)I-TGF-beta(1) and (125)I-alpha(2)M(*) at pH 6 and of forming ternary complexes with (125)I-alpha(2)M(*) and LRP-1 at neutral pH as demonstrated by co-immunoprecipitation. Trifluoperazine and fluphenazine, which inhibit ligand binding to the acidic pH binding sites, block degradation after internalization of cell surface-bound (125)I-TGF-beta(1) or (125)I-alpha(2)M(*). These results suggest that cell surface annexin VI may function as an acidic pH binding site or receptor and may also function as a co-receptor with LRP-1 at neutral pH. 相似文献
997.
β-转化生长因子与肝细胞生长因子在肾间质纤维化中的关系 总被引:2,自引:0,他引:2
肾间质纤维化是各种慢性肾脏疾病的最终通路。研究发现,β-转化生长因子与肝细胞生长因子的平衡关系可能在肾间质纤维化发生发展过程中起着重要作用。 相似文献
998.
就当前制约我国生物医药发展的影响因素进行了全面、细致地分析,并相应地对下一步生物医药R&D的发展提出设想. 相似文献
999.
Guixiang Tang Wenjian Song Ling Xu Zonglai Jin Kasirajan Subrahmaniyan Weijun Zhou 《Acta Physiologiae Plantarum》2006,28(3):273-280
Experiments were conducted to study the influence of sowing seasons and drying methods on the seed vigour of two spring soybean
(Glycine max (L.) Merr.) cultivars. Two cultivars, ‘Huachun18’ and ‘Huachun 14’, were sown in three seasons viz., spring, summer and autumn and the harvested seeds were dried using three different methods. The results showed that soybean
sown in spring had a higher number of branches per plant, pods per branch and seed weight, and consequently resulted in higher
seed yields than that of soybean sown in autumn or summer seasons. Seeds sown in the autumn season had the lowest values of
electrical conductivity during seed imbibitions, higher peroxidase (POD) activity in germinated seedlings and lower contamination
by the seed-borne fungi on the MS medium, which indirectly improved the seed vigour, which was followed by summer sown seeds.
Seeds sown during the spring season resulted in poor seed vigour. In addition, the effect of drying methods on the seed vigour
was also clarified. Seeds that hung for four days before threshing and then air-dried had the poorest seed vigour which was
determined by germination, electrical conductivity, POD activity and seed borne fungal growth. There was no difference in
seed vigour between other methods, i.e. seeds threshed directly at harvest and then air-dried on a bamboo sifter or concrete floor. These results indicated that
autumn sowing soybean and the drying method in which seeds were threshed directly at harvest and then air-dried on a bamboo
sifter resulted in higher seed vigour. 相似文献
1000.