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81.
本文主要观察硫酸铝钾——饮用水净化剂引致小鼠肝酶组化,超微结构和组织结构的变化。动物30只,分为正常组、硫酸铝钾大、小剂量组。实验结果:硫酸铝钾10mg/kg/日(大剂量组)与5mg/kg/日(小剂量组)动物用药10天、80天均可使肝SDH酶活性降低;肝细胞线粒体肿胀、嵴断裂和溶解。在光学显微镜下用药80天后大部分肝细胞肿胀,胞浆疏松淡染、肝小叶内可见呈小灶状分布的炎性细胞浸润,主要为淋巴细胞及浆细胞,门管区偶见少许炎性细胞,但肝小叶和门管区未见结缔组织增生。为此,硫酸铝钾作为净水剂,不宜用量过大。 相似文献
82.
采用超微组织化学方法,观察了体外冲击波碎石术(ESWL)对家免肝脏酶活性的影响。实施 ESWL 后,肝细胞的琥珀酸脱氢酶(SDH)和毛细胆管壁上的碱性磷酸酶(ALP)、焦磷酸硫胺素酶(TPPase)反应活性减弱或消失。TPPase 从损伤的肝细胞高尔基体分泌面扁囊、溶酶体样小泡和毛细胆管内溢出,并伴有肝细胞面的质膜上出现了 TPPase 反应产物和形成膜包内凹小泡。结果提示 ESWL 可对肝细胞及毛细胆管的功能和结构有损伤作用。 相似文献
83.
曲酶F_(23)是一株角质蛋白酶分泌型菌株。我们研究了各种发酵条件如碳源、氮源等对产酶能力的影响,确定了适宜的发酵条件。摇瓶发酵培养基以1%的玉米浆为氮源,1%的玉米粉为碳源,0.3%的羽毛粉为诱导物及各种无机盐和维生素等。最适发酵pH范围为6.5~7.5,最适发酵温度为28℃~32℃,转速为180rpm,发酵102h左右酶活性达238ku/ml。 相似文献
84.
Sequence analyses and evolutionary relationships among the energy-coupling proteins Enzyme I and HPr of the bacterial phosphoenolpyruvate: sugar phosphotransferase system. 总被引:8,自引:0,他引:8 下载免费PDF全文
85.
A. ZUASTI J.H. MARTÍNEZ-LIARTE C. FERRER M. CA
IZARES J. NEWTON J.T. BAGNARA 《Pigment cell & melanoma research》1993,6(5):359-364
The presence of a melanization-stimulating factor (MSF) was discovered in dorsal and/or ventral skin of Sparus auratus. Skin from this marine species was used to condition Steinberg's balanced salt solution (BSS), which was subsequently tested with the neural tube assay. BBS conditioned by dorsal and/or ventral skin of S. auratus at 25% and 50% concentrations had a profound stimulatory effect on the percentage of melanization of neural crest cells throughout the 3day assay period. In some cases 90% melanization occurred within the first 24 hr. Such stimulated cells showed a doubling of the number of dendrites per cell. assess the effects of MSF on other indices of melanization, dorsal and/or ventral skin was used to condition MEM used in the culture of B16-F10 murine melanoma cells. During the first 24 hr, B16-F10 murine melanoma cells responded to conditioned media by demonstrating a considerable increase in activities of tyrosine hydroxylase, dopa oxidase, and dopachrome tautomerase, but no effect was observed on melanin content. In contrast, melanin content increased after 48 hr of incubation, whereas the enzymatic activities were inhibited during this period. It seems that MSF activity, expressed in several ways, may be present generally among marine species. 相似文献
86.
87.
The membrane-bound F1 sector of the H+–ATPase complex (F-type ATPase) in dark-adapted photosynthetic chromatophores is endowed with MgATP- and CaATP-dependent ATPase
activities, both sensitive to inhibitors such as oligomycin and venturicidin. Because of contatamination of free Mg2
+ and Ca2+ ions in chromatophore preparations, kinetic characterization of the two hydrolitic reactions can be performed only in the
presence of both substrates, using a model for two alternative substrates. The two activities are characterized by similar
maximal rates and affinity constants [VMgATP and VCaATP: 13±1 and 10±1 nmol s–1 ATP hydrolyzed (μmol BChl)–1; KMgATP and KCaATP: 0.22±0.06 and 0.20±0.05 mm]. However, only the MgATP-dependent ATPase is coupled to Δ*H
+ generation. In this process CaATP acts as an alternative substrate and a competitive inhibitor of the proton pump, with a
KI coincident with KCaATP for the hydrolytic activity. This finding highlights the central role that the coordination chemistry of the ion-nucleotide
complex plays in determining the proton gating mechanism at the catalytic site(s) of the enzyme complex. These results are
discussed on the basis of the coordination properties of the ions and of the available information on the protein structure.
Received: 5 December 1995 / Accepted: 7 March 1996 相似文献
88.
89.
香附子提取物B处理作物种子效应初报张建新(陕西省农业科学院农业测试中心,杨陵712100)赵伯善(西北农业大学农业化学系,杨陵712100)EffectofseedtreatmentwithextractBfromCyperusrotundus¥Zh... 相似文献
90.
The Nucleotide Sequence of Human Acylamino Acid-Releasing Enzyme 总被引:3,自引:0,他引:3
Mitta Masanori; Ohnogi Hiroshi; Mizutani Shigetoshi; Sakiyama Fumio; Kato Ikunoshin; Tsunasawa Susumu 《DNA research》1996,3(1):31-35
The nucleotide sequence of a cDNA coding for the human acylaminoacid-releasing enzyme (AARE, also known as acylpeptide hydrolase)[EC 3.4.19.1] subunit has been determined. The amino acid sequenceof human AARE subunit deduced from its cDNA nucleotide sequenceshowed a high degree of identity (91.5%) with both the correspondingproteins from the pig and the rat. The AARE cDNA shows 99.2%identity with a 3.3 kb cDNA transcribed from a locus (DNF15S2)on the short arm of human chromosome 3, whose deletion is associatedwith small cell lung cancer, taking into consideration thatthe sequence of the 3.3-kb cDNA previously reported was causedby misreading. 相似文献