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111.
112.
本实验采用D-氨基半乳糖(D-GalN)诱导的大鼠急性肝损伤模型,观察大鼠肝脏组织化学的变化,探讨肝炎平对急性肝损伤的保护作用。实验分为四组,即正常对照组、模型组、肝炎平及肝得健保护组。结果表明:肝炎平对肝细胞膜系统有一定的保护作用。肝炎平组和肝得健组SDH、CCO及ChE活性明显高于模型组,且与正常对照组相近。本实验模型组ACP的活性明显高于正常组,而肝炎平组ACP的活性明显低于模型组,与正常对照组无显著性差异。提示:肝炎平可显著改善因D-氨基半乳糖所致肝损害的作用。且其对肝细胞的保护作用与肝得健一致。 相似文献
113.
将人粒细胞-巨噬细胞集落刺激因子(GM-CSF)和人血清白蛋白第三功能区(HAS-D3)的基因串联后,在E.coli中获高效表达,表达量占菌体蛋白的32.6%.利用TF-1体外细胞活性测定表明,GM-HSA的活性单位为1.04×10~6U/mg,虽然其比活性低于GM-CSF,但比后者具有更高的体外热稳定性和储藏稳定性. 相似文献
114.
Hongkui Jin Renhui Yang Gilbert A. Keller Anne Ryan Annie Ko David Finkle Todd A. Swanson WeiLi Diane Pennica William I. Wood Nicholas F. Paoni 《Cytokine》1996,8(12):920-926
Cardiotrophin-1 (CT-1) is a recently discovered cytokine that was isolated based on its ability to induce cardiac myocyte hypertrophy in vitro. In this study, the effects of chronic administration of CT-1 to mice (0.5 or 2 μg by intraperitoneal injection, twice a day for 14 days) were determined. A dose-dependent increase in both the heart weight and ventricular weight to body ratios was observed in the treated groups. The body weights of the animals were unaffected. These results indicate that CT-1 can induce cardiac hypertrophy in vivo. CT-1 was not specific for the heart, however. It stimulated the growth of the liver, kidney, and spleen, and caused atrophy of the thymus. CT-1 administration also increased the platelet counts by 70%, with no change in mean platelet volume. Red blood cell counts were increased in the treated animals, and there was a concomitant increase in haemoglobin concentration. Thus, CT-1 has a broad spectrum of biological activities in vivo. This observation is consistent with previous in-vitro findings showing that the mRNA for CT-1 is expressed in several tissues, and that CT-1 can function through binding to the leukaemia inhibitory factor (LIF) receptor and signalling through the gp130 pathway. 相似文献
115.
此项工作在新疆平原荒漠区盐化草甸带进行。研究结果显示出K、Na、Ca、Mg 4种元素在植物体内不同器官的含量分布特点和各个器官中不同元素间的含量关系。同时表明这4种元素在植物体不同器官中具有不同的作用。对于K、Na元素,地上部器官尤其叶片中含量水平反映出器官具有较强的留K排Ns的选择性元素的分配机制。 相似文献
116.
A suitable medium was developed from modified Richard's medium plus V8 juice (RM8) to produce high levels of desiccation-tolerant conidia ofTrichoderma harzianumstrain 1295-22. The addition of 9% (v/v) glycerol to RM8 improved both biomass production and desiccation tolerance of the conidia ofT. harzianum.This medium was then used in a laboratory scale fermenter (1.5 liter) to determine optimal operating conditions. The optimal temperature for conidial production and desiccation tolerance improvement in the fermenter was 32°C when dissolved oxygen was maintained at 50% saturation of air, and the stirring rate was 1000 revolutions per minute. The initial water potential of the medium (with 9% glycerol) was −3.7 MPa, the pH was 6, and neither was controlled during fermentation. Changes in medium pH and dissolved oxygen were associated with the stages of morphological development and conidiation. The pH of the medium decreased concurrently with germ-tube elongation and mycelium development and then increased to 6.0–6.2 at phialide formation. Intensive conidiation occurred at pH 6.3–6.5 and reached its maximal level at 6.9–7.1. Changes in pH values could be used as indicators to monitor the morphological development and conidiation ofT. harzianumduring fermentation. The use of a 48-h-old culture inoculum, rather than conidial inoculum, to start fermentation reduced the time required to complete the shift from vegetative growth to phialide formation. Intensive conidiation occurred immediately after the addition of culture inoculum and reached maximum levels within 68 h of fermentation. Dry weight of biomass increased with the duration of fermentation and was greatest at 96 h. However, no improvements in conidia/gram and CFU/gram were achieved after 72 h of fermentation. The desiccation tolerance of conidia harvested at 72 or 96 h was significantly (P = 0.05) greater than that of conidia harvested at 48 h of fermentation. Results obtained from this study could be used for further scale-up of the fermentation process. 相似文献
117.
Richard J. Bold Jin Ishizuka Srinivasan Rajaraman †J. Regino Perez-Polo Courtney M. Townsend Jr. James C. Thompson 《Journal of neurochemistry》1995,64(6):2622-2628
Abstract: Carcinoid tumors are a group of neuroendocrine neoplasms distributed widely throughout the body but most commonly occurring in the gut. These tumors retain many characteristics of their neural crest origin, including secretion of neuroactive peptides and responsiveness to neurotrophic substances. Nerve growth factor (NGF), a neurotrophic protein involved in maintenance and differentiation of peripheral sympathetic and sensory neurons, regulates growth of several neural tumor cells by inducing a differentiated phenotype and subsequent inhibition of cell growth rate. We examined the actions of NGF in a functioning human pancreatic carcinoid cell line (termed BON). NGF has no effect on the cytoarchitecture or constitutive secretion of bioamines in this carcinoid cell line. NGF, however, stimulates the in vitro cellular proliferation of BON cells. BON cells possess mRNA for the NGF receptors (p75LNGFR and p140trkA ) and membrane-associated tyrosine kinase activity is increased in response to NGF. Both the mitogenic activity of NGF, as well as the receptor-linked tyrosine kinase activity, can be abrogated in BON cells by the trkA inhibitor K-252a and specific anti-NGF antibody. Our studies demonstrate that NGF is a mitogen for this carcinoid cell line without effect on cellular phenotype or cytoarchitecture. NGF may play a role in the development and progression of human carcinoid tumors. 相似文献
118.
Genetic and cytological studies were conducted with a new male-sterile, female-fertile soybean [Glycine max (L.) Merr.] mutant. This mutant was completely male sterile and was inherited as a single-recessive gene. No differences in
female or male gamete transmission of the recessive allele were observed between reciprocal cross-pollinations in the F1 or F2 generations. This mutant was not allelic to any previously identified soybean genic male-sterile mutants: ms1, ms2, ms3, ms4, ms5, or ms6. No linkage was detected between sterility and flower color (W1 locus), or between sterility and pubescence color (T1 locus). Light microscopic and cytological observations of microsporogenesis in fertile and sterile anthers were conducted.
The structure of microspore mother cells (MMC) in male-sterile plants was identical to the MMCs in male-fertile plants. Enzyme
extraction analyses showed that there was no callase activity in male-sterile anthers, and this suggests that sterility was
caused by retention of the callose walls, which normally are degraded around tetrads at the late tetrad stage. The tapetum
from male-sterile anthers also showed abnormalities at the tetrad stage and later stages, which were expressed by an unusual
formation of vacuoles, and by accumulation of densely staining material. At maturity, anthers from sterile plants were devoid
of pollen grains.
Received: 13 May 1996 / Revision accepted: 19 August 1996 相似文献
119.
盘县大洞的发育与演化 总被引:2,自引:0,他引:2
盘县大洞是一个形态和成因复杂的大型喀斯特洞穴系统,本文通过对喀斯特作用与坡立谷结构,古水系变迁与洞穴形成等动力地貌-洞穴过程分析,探讨区域喀斯特及洞穴形成演化的水动力成因,结合岩相古地理环境等推测指出,关牛洞形成早更新世和中更新世早期,大洞洞厅,阴河坡,消洞和水洞形成于更新世早期至中更新世中期,十里坪坡立谷的形成始于中更新世早期,并经历后来反复积水-消水,侵蚀-堆积过程直至全新世。 相似文献