植物类药材基因组DNA提取与纯化的方法学研究

本文探讨了菊科9种植物和地胆草的4种对口商品药材基因组DNA提取与纯化的原理、方法，通过对3种常用植物基因组DNA提取方法（CsC1梯度超速离心法、CTAB／CsC1梯度超速离心法和DTAB微量提取法）的条件摸索，在DNA产率、纯度以及提取纯化过程中影响PCR扩增因子方面进行比较，认为CTAB微量提取法是植物类药材基因组DNA一种比较省时、有效、经济的提取方法。     

玉竹基因组DNA的提取与分析

目的以玉竹根茎为材料,寻找一种适合于玉竹总DNA提取的方法,便于下游分子生物学的操作。方法采用经典CTAB法与改良CTAB法。结果改良CTAB法提取得到的DNA可以很好地用于PCR扩增。结论改良CTAB法适用于类似玉竹这类含多糖较多的根及根茎类中药材DNA的提取。     

蒙药材山野豌豆总DNA提取方法研究

目的 寻找快速、简便的山野豌豆总DNA提取方法。方法 采用4种不同方法(CTAB法、SDS法及改进CTAB法、改进SDS法)提取山野豌豆总DNA,通过琼脂糖凝胶电泳和紫外分光光度计检测其纯度,以筛选出最优提取方法。结果 改进CTAB法和改进SDS法所得的山野豌豆总DNA纯度都较高,A260和A280分别为(1.9128±0.0827)和(1.8767±0.0408)。改进CTAB法提取到的总DNA电泳时DNA条带亮度明显,无拖尾现象。结论 改进CTAB法是提取山野豌豆中高质量总DNA的有效方法。     

牡丹皮基因组DNA提取的影响因素研究

目的:研究牡丹皮基因组DNA提取的影响因素。方法:以根皮类中药材牡丹皮为材料,在快速少量抽提(CTAB)法的基础上对提取缓冲液中氯化钠、β-巯基乙醇浓度,水浴温度、时间,RNA酶(RNaseA)、聚合酶链(PCR)反应体系等条件进行考察。结果:使用经过改进后的CTAB法获得的DNA纯度和完整性较好,A260/A280值在1.8～2.0之间,PCR扩增条带清晰且亮,从而为接下来的分子生物学实验打下了良好的基础。结论:本方法经济、快速、高效,可作为根皮类中药材基因组DNA的提取方法,可为大规模生产提供理论依据。     

一种适于ISSR分析的太子参DNA提取方法

目的获得能用于中药太子参简单序列重复区间DNA标记技术等分析研究的高质量DNA。方法以太子参为材料,采用改良CTAB法提取太子参DNA,经紫外分光光度计和琼脂糖凝胶电泳检测。结果改良的CTAB法能获得高质量的太子参DNA,OD260/OD280>1.8,蛋白质、多糖、RNA等去除较彻底,适于简单序列重复区间分析。结论改良的CTAB法所提取太子参DNA适于简单序列重复区间分析。     

白木香基因组DNA的提取及AFLP银染体系的建立

用改良的CTAB法提取不同居群的白木香基因组DNA，通过优化AFLP技术中关键步骤的参数，建立适合白木香的AFLP银染反应体系。结果表明，改良的CTAB法提取的白木香基因组DNA纯度高，完整性好，满足AFLP分析的要求；250ng的基因组DNA用EcoRI和MseI37℃消化3h后可以被完全酶切，酶切产物和接头经16℃连接过夜后，用带有一个选择性碱基的引物和带有3个选择性碱基的引物分别进行预扩增和选择性扩增，扩增产物经变性聚丙烯酰胺凝胶电泳分离，用AgNO3染色得到了清晰的指纹式样，为下一步的遗传分析奠定了基础。     

药用百合鳞叶中总DNA提取方法的研究

目的:对药用百合DNA的提取过程进行改良和优化,筛选出较理想的DNA提取方法。方法:在传统十六烷基三甲基氯化铵(CTAB)提取方法基础上,进行改良和优化,寻找出一种实用的DNA提取方法。结果:用改良CTAB法提取的总DNA的OD260/OD280在1.6~2.0之间,电泳条带清晰,其含量和纯度完全满足引物扩增分析的要求。结论:本试验中的百合鳞叶总DNA的提取方法简便实用,所得DNA的产量和纯度均能满足基因工程操作的要求。     

川芎DNA提取方法的研究

目的 以伞形科蒿本属植物川芎Ligusticum chuanxiong Hort.叶为材料,研究川芎DNA的提取方法 .方法 分别采取CTAB法、高盐低pH法、木本植物DNA提取法、改良高盐低pH法提取基因组DNA,并对4种方法进行了改进.通过0.9%琼脂糖凝胶电泳和RAPD两种方法检测所提取的DNA样品.结果 比较DNA产量、质量等,确定了木本植物DNA提取法最佳.结论 木本植物DNA提取法为最佳方法.     

何首乌扩增长度多态性反应及银染体系的建立

目的 通过对各主要影响因素的研究,建立适于何首乌扩增长度多态性（AFLP）反应体系及银染体系. 方法 采用改进的CTAB提取方法从何首乌的嫩叶中提取获得总DNA;从酶切DNA的量、时间等考察酶切体系,并设计正交实验进行预扩体系和选扩体系的优化. 结果 酶切体系DNA的适用量为400 ng,37 ℃酶切5 h;用较优的预扩增体系和选择性扩增得到的选择性扩增产物在6%变性聚丙烯酰胺凝胶上电泳,得到清晰的指纹图谱. 结论 所建立的反应体系可有效地应用于何首乌的分类鉴定和道地性鉴定.     

贝母属药用贝母总DNA提取方法的比较研究

目的 比较筛选最适于贝母属药用贝母的总DNA提取方法。方法 利用试剂盒法、改良的CTAB法、改良的SDS法提取贝母属药用贝母的总DNA;通过核酸蛋白检测仪及琼脂糖凝胶电泳方法检测其浓度和纯度;进行ISSR-PCR扩增检测所得总DNA质量。结果 3种方法均可提取出产量较高的基因组DNA,但试剂盒法相较提取的总DNA纯度最高,质量最好,并且均能扩增出丰富清晰的条带,稳定性高,操作简单耗时短。改良的CTAB法、SDS法提取的总DNA纯度、质量均次于试剂盒法,操作复杂耗时长,不适用于下游的分子生物学实验。结论 试剂盒法为贝母属药用贝母总DNA提取的最佳方法,其所得样品适用于PCR及其他分子生物学研究。     

Synthesis and testing of quinone-based bis(2,2-dimethyl-1-aziridinyl)phosphinyl carbamates as radiation-potentiating antitumor agents

Two new drug candidates, in which a quinonoid moiety is linked to the reactive bis(2,2-dimethyl-1-aziridinyl)phosphinyl function, have been prepared and tested in vivo for antitumor activity and in vitro as potentiators of the cytotoxic effect of X-irradiation. Without irradiation only moderate effectiveness against leukemia P-388 in mice was exhibited by one of the quinonoid compounds that had sufficient water solubility to be used in the in vivo screening. However, both compounds were shown to potentiate the effect of X-irradiation in vitro by a colony-forming cell culture assay under hypoxic conditions.     

Comparason of extraction methods for PCR detection of <Emphasis Type="Italic">Burkholderia cepacia</Emphasis> complex (BCC) from cystic fibrosis patients

Direct detection of Burkholderia cepacia complex (BCC) and its genomovars from sputum by molecular tests emerges as a method for rapid identification. In this study, four DNA extraction methods were evaluated for the identification for BCC from sputum of CF patients. Sputa from 28 CF patients were aliquoted and spiked with BCC reference strain. Boiling, phenol-chloroform, CTAB methods and a commercial spin column kit was used for DNA extraction. Total DNA yields were determined by spectrophotometry and single-round recA PCR was used for detection of BCC. No significant difference was observed in DNA yields from different extraction methods. Lower limit of detection for recA PCR was determined as 10⁶ cfu/ml. Amplification was observed in 7/16 (43.7%) of sputa for boiling, 8/16 (50%) of sputa for CTAB and 13/16 (81.2%) of sputa for phenol-chloroform method and spin column kit in the assay sensitivity range determined in the study. Phenol-chloroform and commercial spin column kit were found to be better suited for DNA purification from sputum of CF patients for BCC identification. Diagnostic impact of single-round recA PCR directly from sputum was limited to chronically-infected patients.     

Xenoestrogenicity in in vitro assays is not caused by displacement of endogenous estradiol from serum proteins.

The possibility that compounds tested for estrogenicity can compete for binding places on serum proteins and cause an increase of available and very potent endogenous estrogens is of great interest for both the in vitro assay results and the prediction of risk for humans. In in vitro assays, small amounts of estradiol remaining after the charcoal stripping of serum applied in the culture medium could be displaced by the tested compounds, leading to an estrogenic response that might be falsely attributed to the test compound. We have studied the stripping efficiency of charcoal and measured whether reported xenoestrogens can displace estradiol from serum in an in vitro assay using negligible depletion-solid phase microextraction (nd-SPME). Possible competition was also studied with a mathematical exposure model, from which the predictions were compared to the measurements. We found that the common charcoal stripping procedure removed 99% of initially present estradiol. Additionally, our results with charcoal adsorption indicate that charcoal is not useful for serum protein binding assays, as it adsorbs more than the free fraction of ligand. Although the competition model predicted a displacement of estradiol from the serum proteins at the higher applied doses of xenoestrogen, the measurements showed no displacement. Therefore, we conclude that estrogenic responses in the in vitro assay applied here are not caused by displacement of remaining estradiol in the stripped serum. The possibility remains, however, that our displacement hypothesis does apply for estrogen sulfates, as these are present in much higher concentrations than estradiol in stripped serum.     

Method development for betamethasone and dexamethasone by micellar liquid chromatography using cetyl trimethyl ammonium bromide and validation in tablets. Application to cocktails

An isocratic liquid chromatographic method for the determination of betamethasone (BM) and dexamethasone (DM) using methylprednisolone (MPL) as internal standard and micellar mobile phases consisting of cetyl trimethyl ammonium bromide (CTAB) and organic modifiers such as propanol, butanol and pentanol has been developed. The effect of organic modifiers, surfactant concentration, temperature and flow-rate on the separation has been studied. Method validation for dexametasone or bethametasone in tablets was carried out using a mobile phase 0.24% pentanol and 32.5 mM CTAB, a flow-rate of 0.5 ml min(-1), an Hypersil C18 column (60 degrees C), and UV detection at 243 nm. The recoveries for BM and DM found in the accuracy test were 99 +/- 3 and 101 +/- 2, respectively. Repeatability and intermediate precision expressed as R.S.D. were lower than 5% for both compounds. The proposed method was applied to cocktails containing both compounds.     

Factors influencing the clinical efficacy of activated charcoal

The use of activated charcoal as part of the treatment of intoxicated patients has increased dramatically over the last ten years. Activated charcoal is currently suggested as therapy to prevent the absorption of orally ingested compounds, and is gaining popularity as a method of increasing systemic drug clearance. This review presents variables that should be considered when activated charcoal is used in the treatment of intoxicated patients. Variables that may alter the efficacy of charcoal therapy include the preparation and dose of charcoal used, the intoxicants involved, stomach contents, the gastrointestinal pH, concurrently administered materials, and time from toxin ingestion to charcoal administration. As a general guideline, a single, large dose should be administered with a cathartic as soon as possible after oral ingestion to prevent drug absorption. When charcoal is used to enhance systemic drug clearance, the dosage regimen should be individualized, based on the drugs involved and the patient's gastrointestinal tract function, fluid and electrolyte status, and the severity of intoxication.