促肝细胞生长物质对实验性肝损伤动物的肝脏修复作用

本实验测定了促肝细胞生长物质对CCl4 诱导的中毒性肝损伤及D 氨基半乳糖致急性肝衰竭的动物的恢复与治疗作用 ,发现促肝细胞生长物质能促进受损肝细胞的增长 ,迅速降低肝损伤后的ALT水平 ,降低肝衰竭动物的死亡率 ,对肝脏起很好的保护作用。并发现促肝细胞生长物质还能减少受损肝组织中的纤维细胞 ,防止肝硬化的形成。     

促肝细胞生长物质(HSS)

促肝细胞生长物质(hepaticstimulatorysubstance,HSS)不仅能够阻止肝损伤、启动肝细胞增殖再生,而且可以部分恢复肝功能以及具有抗氧化作用,因此有较为广阔的应用前景。     

促细菌生长物质及机理研究进展

促细菌生长物质是一类通过直接或间接作用于细菌生长代谢过程而加速细菌生长繁殖速度或为细菌生长繁殖所必需的物质的总称,对其进行研究和利用会在微生物快速检验、生物工程,经济菌类生产方面带来实际应用价值。本文介绍了几类近10年来国内外报道的促细菌生长物质及其促生长机理研究进展。     

猪肝刺激物质pHSS对离体肝细胞DNA合成的影响

应用[~3H]TdR掺入离体培养大鼠肝细胞DNA的方法,测定由本室提取的pHSS的生物活性。结果表明,pHSS可显著促进原代培养大鼠肝细胞的DNA合成,其促进率约为对照组的10倍左右。培养液中血清浓度对pHSS的生物活性表达有显著影响,不同浓度血清可以使pHSS表现出不同的量效关系,这些结果在Buffello大鼠肝细胞系的实验中得到进一步证实。在低剂量pHSS的刺激下,不同年龄大鼠肝细胞的[~3H]TdR掺入率无显著差异。但高剂量时,pHSS对幼鼠作用不明显。     

离子注入哈茨木霉筛选高产促植物生长物质菌株的研究

用 N+注入哈茨木霉所获得的突变型的发酵液浇灌水稻种子 ,结果发现 :5× 10 - 6、5× 10 - 5、2× 10 - 4木霉突变株发酵稀释液处理的种子幼苗长势优于对照组和木霉原种组。其 5 0倍、15 0倍木霉发酵稀释液浇灌的种子幼苗过氧化物酶同工酶与对照和原种相比均出现了新的谱带 A- 3、C- 3带。各突变株 5 0倍发酵稀释液和原种发酵液浇灌的水稻幼苗过氧化物酶同工酶出现了 B- 3带。而四种浓度的木霉发酵稀释液处理的水稻幼苗 ,其酯酶同工酶与对照组和原种组相比 ,无明显差异     

我国促肝细胞生长因子的研究和应用

促肝细胞生长因子具有促进细胞增殖和生长的作用,国内外研究较多。我国对肝细胞生 长因子的研究和应用主要集中在肝源性促肝细胞生长因子上。在总结国内学者历年研究成果的 基础上,结合我国生产和应用的实际情况,对促肝细胞生长因子的来源、结构、理化性质、生产及 应用情况进行了综述,有助于更深入研究。     

促肝细胞生长素对肝损伤小鼠脂质过氧化的影响

将脱毒甘薯叶节苗基端于布洛芬液浸10min然后扦插,能有效地促使薯苗生根,增加根数和根干重,提高根系活力;并能促使薯苗生长,茎叶干重和腋芽发育成的枝数增加,茎节繁殖系数提高。布洛芬的最适作用浓度为1000mg·L-1。     

鱼类促摄食物质研究进展

一般来说,缺乏鱼类摄食方面的知识,就不可能合理地经营养殖业,而忽视鱼类对饲料的嗜好性也将是饲料科学中的一个重大缺陷。       

测定昆虫细胞存活或死亡的MTT方法的改进

MTT方法具有灵敏、简便、稳定可靠、不需同位素等特点。为了摸索测定昆虫细胞存活（或死亡）的MTT方法的各种最适条件,本文以中国棉铃虫细胞系为对象,确定了一些基本参数、并比较了三种MTT测定方法。结果表明：改进的方法所选用的溶剂——pH为4.5的3％SDS异丙醇效果最好,溶解甲所需时间短、OD值高。测定昆虫细胞范围为每孔500～60000细胞,测试波长为560nm,参考波长为690nm.     

^3H—胸腺嘧啶核苷参入法测定胰岛素促生长活性

利用＾３Ｈ－胸腺嘧啶核苷参入方法,在２４孔板和９６孔板培养的小鼠乳腺癌细胞ＧＲ２Ｈ６中,建立了胰岛素促细胞生长活性的测定体系。这一方法具有操作简便、周期较短和便于进行大量样品分析和测试等优点,它为研究胰岛素促生长功能与结构的关系提供了适当的新研究体系。     

SRB法和MTT法抗肿瘤药物筛选结果相关性研究

为了探索抗肿瘤药物体外筛选中磺酰罗丹明B（SRB）法和四甲基偶氮唑盐（MTT）比色法实验结果的相互验证作用,作者以PC-3、BGC-823、Bcap-37细胞系为研究对象,利用SRB法和MTT比色法对供试化合物行体外抑制活性考察,并用SPSS12．0对两种筛选方法得到的实验结果进行差异性分析。结果表明,SRB法和MTT比色法实验结果相关性好,可以相互验证实验结果的准确性和可靠性。     

MTT法用于药物对L2细胞毒性的实验研究

目的：评价噻唑蓝（MTT）法检测药物对细胞的毒性作用的可靠性。方法：大鼠肺泡上皮L2细胞以叔丁基对苯二酚（TBHQ）10．100μM,BsO以1-10mM分别处理,用MTT法检测细胞活性、JC-1（5,5’,6,6’-四氯．1,1’,3,3’-四乙基苯并咪唑羰花青碘化物）荧光染料法检测细胞线粒体电位改变、台盼蓝排斥实验检测细胞死亡率,分析各指标的情况。结果：在处理剂量范围,MTT法检测到的光密度（OD）值未能达到一般判断的半数抑制浓度（ic50）水平,最高抑制率仅达到30％左右;台盼蓝排斥试验检测数据表明TBHQ的LC50值为50μM,丁硫氨酸亚砜胺（BSO）为5mM;利用JC-1荧光染料判断的半数凋亡剂量分别为50μM和7mM。结论：MTT法作为最常采用的细胞生长抑制检测手段,但在某些特定实验中可能不能客观地反映细胞的活性,建议多种方法结合进行评价。     

A colorimetric assay for sulfiredoxin activity using inorganic phosphate measurement

2-Cys peroxiredoxin (Prx) is the major subgroup of a family of Prx enzymes that reduce peroxide molecules such as hydrogen peroxide (H₂O₂). 2-Cys Prxs are inactivated when their active site cysteine residue is hyperoxidized to sulfinic acid. Sulfiredoxin (Srx) is an enzyme that catalyzes reduction of hyperoxidized 2-Cys Prxs in the presence of ATP, Mg²⁺, and thiol equivalent. Therefore, Srx activity is crucial for cellular function of 2-Cys Prxs. The method currently available for the determination of Srx activity relies on immunoblot detection using antibodies to hyperoxidized enzymes. Here we introduce a simple quantitative assay for Srx activity based on the colorimetric determination of inorganic phosphate released in Srx-dependent reduction of hyperoxidized Prx using the malachite green. The colorimetric assay was used for high-throughput screening of 25,000 chemicals to find Srx inhibitors.     

Assessing cytotoxicity of boron nitride nanotubes: Interference with the MTT assay

Thanks to a non-covalent wrapping with glycol-chitosan, highly biocompatible and highly concentrated dispersions of boron nitride nanotubes were obtained and tested on human neuroblastoma cells. A systematic investigation of the cytotoxicity of these nanovectors with several complementary qualitative and quantitative assays allowed a strong interference with the MTT metabolic assay to be highlighted, similar to a phenomenon already observed for carbon nanotubes, that would wrongly suggest toxicity of boron nitride nanotubes. These results confirm the high complexity of these new nanomaterials, and the needing of extensive investigations on their exciting potential applications in the biomedical field.     

Development of a new colorimetric assay for lipoxygenase activity

Lipoxygenases (LOXs) are a family of non-heme iron-containing dioxygenases that catalyze the hydroperoxidation of lipids, containing a cis,cis-1,4-pentadiene structure. A rapid and reliable colorimetric assay for determination of the activity of three human functional lipoxygenase isoforms (5-lipoxygenase, platelet 12-lipoxygenase, and 15-lipoxygenase-1) is developed in this article. In the new assay, LOX-derived lipid hydroperoxides oxidize the ferrous ion (Fe²⁺) to the ferric ion (Fe³⁺), the latter of which binds with thiocyanate (SCN^–) to generate a red ferrithiocyanate (FTC) complex. The absorbance of the FTC complex can be easily measured at 480 nm. Because 5-LOX can be stimulated by many cofactors, the effects of its cofactors (Ca²⁺, ATP, dithiothreitol, glutathione, l-α-phosphatidylcholine, and ethylenediaminetetraacetic acid) on the color development of the FTC complex are also determined. The assay is adaptive for purified LOXs and cell lysates containing active LOXs. We use the new colorimetric assay in a 96-well format to evaluate several well-known LOX inhibitors, the IC₅₀ values of which are in good agreement with previously reported data. The reliability and reproducibility of the assay make it useful for in vitro screening for inhibitors of LOXs and, therefore, should accelerate drug discovery for clinical application.     

Development of an isoenzyme-specific colorimetric assay for tissue transglutaminase 2 cross-linking activity

Tissue transglutaminase (TGase 2) belongs to the multigene transglutaminase family of Ca²⁺-dependent protein cross-linking enzymes. Based on the transamidation activity of TGase 2, a novel colorimetric assay has been developed using covalently coupled spermine to carboxy-substituted polystyrene plates and biotinylated pepT26, an excellent acyl-donor substrate, highly specific for TGase 2. The assay is based on the incorporation of the gamma-carboxamide of glutamine of pepT26 into the immobilized spermine. The amount of biotinylated pepT26 bound to the plate, as measured by the activity of streptavidin-peroxidase, is directly proportional to the TGase activity. The colorimetric procedure showed a good correlation (r = 0.995) with the commonly used radiometric filter paper method for TGase2, and provides linear dose-response curves over a wide range of hrTGase2 concentrations (2.5-40 μU/ml). In addition, the assay shows higher sensitivity when compared with our previous TG-colorimetric test (more than 50-fold increase) and other existing assays. PepT26 displays strong reactivity with TGase 2, and no reactivity with TGases 1, 3, and FXIII. The procedure constitutes a rapid, TG2-specific, sensitive, and nonisotopic method for the measurement of TGase 2 activity in as low as 4 ng of hrTGase 2 and purified guinea pig liver transglutaminase, and 1.25 μg of guinea pig liver extracts.     

MTT法检测石刁柏悬浮细胞技术的研究

本研究确定了MTT法测定悬浮培养的石刁柏细胞活力所需的最适条件为:比色波长560nm,最适缓冲液为柠檬酸钠-Vc缓冲液,渗透促进剂为二甲基亚砜,洗脱剂为酸化异丙醇,0.133%浓度的MTT溶液适于对未知培养时期的细胞计数,0.267‰浓度的MTT溶液适于鉴定细胞活力;同时,本研究通过MTT对培养细胞的生长过程进行了测定,确定细胞活性最强时期为指数期;并研究了细胞数量与吸光值之间的关系以及培养时间对MTT染色的影响.     

Development of a colorimetric colony‐screening assay for detection of defluorination by micro‐organisms

Aims: To develop a colorimetric colony‐screening assay to facilitate the isolation of micro‐organisms capable of defluorination. Methods and Results: A metal‐dye chelate, zirconium‐xylenol orange was used to detect fluoride ions released from a fluorinated substrate through microbial metabolism. Depolymerised zirconium reagent gave the greatest visual contrast for the presence of fluoride compared to more polymerised forms of zirconium reagent. The sensitivity of the assay was greatest when the molar ratio of depolymerised zirconium to xylenol orange was 1 : 2. Using depolymerised zirconium and xylenol orange (150 and 300 nmol l^?1 respectively), the assay could detect a fluoride application spot (5 mmol l^?1) containing 50 nmoles of fluoride ions. Most media constituents were well tolerated by the assay, although phosphate ions needed to be restricted to 0·1 g l^?1 and some proteins digest to between 1 and 5 g l^?1. A microbial enrichment culture growing on solidified medium containing 20 mmol l^?1 fluoroacetate was screened using the assay, and defluorinating bacteria belonging to the genus Burkholderia isolated. Conclusions: A method was developed that is sensitive, rapid and reliable for detecting defluorination by micro‐organisms growing on solidified medium. Significance and Impact of the Study: This method can be used to facilitate the isolation of micro‐organisms capable of defluorination.