导读与评议(2017年第6期)

正精准医疗概念的提出开启了一个医学新时代,其实质包括精准诊断和精准治疗。张文宏课题组围绕结核病治疗中的精准医疗进行了阐述,涉及结核病的精准诊断,包括结核病的临床诊断及结核分枝杆菌的检测(分子检测及耐药检测技术等)、特殊人群的药理学参数与药物代谢相关的分子标记、针对病原体生命周期分子靶点的直接作用药物研发、通     

精准医疗与肿瘤免疫治疗伴随诊断

以免疫检查点阻断疗法为代表的肿瘤免疫治疗在肿瘤临床治疗中取得了突破性进展,然而肿瘤免疫治疗伴随诊断仍存在诸多困难。在当前精准医疗大发展的背景下,创新性的技术和方法不断应用到肿瘤免疫治疗的伴随诊断中,对于提高肿瘤免疫治疗的效率具有重要意义。现有研究发现肿瘤微环境PD-L1的表达检测、肿瘤突变和肿瘤变异新抗原分析、肿瘤微环境免疫相关基因表达谱分析等方法与肿瘤免疫治疗效果具有显著相关性,然而其临床应用仍具有一定局限性,导致精准的肿瘤免疫治疗伴随诊断仍面临诸多挑战。主要介绍了免疫检查点阻断治疗相关伴随诊断领域研究进展,提出肿瘤免疫治疗伴随诊断需要开放式思维,积极引入新技术新方法,拓展多元化分子标识,从而推动肿瘤免疫治疗实现个体化精准应用。     

基于质谱技术的肺癌代谢标志物筛选研究进展

肺癌早期诊断可显著改善患者预后,提高患者生存率。肺癌发生发展进程伴随机体代谢物变化,因此通过对体内代谢通路的全面检测,进而结合生物信息学工具分析代谢应答变化,可高效筛选肺癌相关代谢标志物,有助肺癌早期发现。近年来已开发多种代谢检测技术用于肺癌代谢标志物筛选,其中质谱技术在检测的灵敏度、特异性、分析速度、多指标平行检测等方面展现出显著优势,因此在癌症诊断、疾病监测和治疗等领域有重要地位。该文概述了质谱技术方法在肺癌临床诊疗应用中的最新研究进展,并对应用质谱方法学研究生物标志物的前景进行了系统性展望。通过对近期研究的深入了解,预期将进一步理解肺癌代谢特征,为肺癌早期诊断和治疗提供精准评估技术手段。     

基因组学技术推动中医药精准医学研究现状分析与展望

中医药具有精准医学的核心"个体化诊断和治疗"要素。基因组学技术在中医药基于体质的精准预防、个体化诊断与药物、针灸治疗、药物复杂性、包括中医药干预人体微生物环境等方面已经有较多应用。这与精准医学通过分析人群基因信息、生活方式、环境因素等了解疾病发生发展机制、针对相关靶点开发药物的方法及目标相匹配。未来将在整合各组学技术、结合中医药自身特色等方面应用于中医药精准医学研究,为实现中医药现代化及精准治疗的目标提供助力。     

2023年肿瘤精准医学发展态势

肿瘤的高度复杂性和异质性使其治疗面临巨大挑战,而精准医学的发展为其带来新机遇,成为肿瘤医学的重要发展模式。经过几年的发展,肿瘤精准医学不断推进,相关成果持续涌现。该文在系统梳理2023年全球肿瘤精准医学的发展布局与举措,总结领域发展现状与发展趋势的基础上,展望了肿瘤精准医学领域的未来发展方向。当前,全球已建设多个肿瘤相关的大型人群队列,为肿瘤精准医学的实现提供了重要资源基础。随着精准医学理念的深入和生命组学技术的革新,基因检测、液体活检、伴随诊断等精准诊断技术以及靶向药物、免疫治疗、RNA疗法等先进治疗手段逐渐成熟,不仅推动了对肿瘤发生发展机制的深入解析,使得肿瘤精准分型取得快速突破,并逐渐用于指导临床实践;而且推动了新技术、新应用、新产品的快速突破,从而助推肿瘤精准医学的实现。     

基于病灶图像特征提取的光动力治疗方案

识别和分析病灶区域是光动力治疗的一个重要环节。以鲜红斑痣疾病为例,光动力治疗是利用光、光敏剂和分子氧对病变细胞进行强烈的光动力作用,让活性氧杀死病变细胞,最终达到治疗疾病的目的。传统的治疗方案存在病灶区域无法精确诊断、无法精准治疗和总体治疗成本较高等问题。本研究方案设计了一款用于照射治疗鲜红斑痣的窄光谱LED光源,根据病灶特征计算病灶区域分布与病灶程度,最后根据计算结果制作非均匀透射密度的胶片,用于精准调控治疗光源强度。试验结果显示,图像特征提取技术、设计的光源和胶片能够解决光动力治疗中无法精确诊断、无法精准治疗和治疗光源均匀性等问题,在试验描述的鲜红斑痣治疗方面具有广阔的应用前景。     

导读与评议（2017年第6期）

精准医疗概念的提出开启了一个医学新时代,其实质包括精准诊断和精准治疗。张文宏课题组围绕结核病治疗中的精准医疗进行了阐述,涉及结核病的精准诊断,包括结核病的临床诊断及结核分枝杆菌的检测(分子检测及耐药检测技术等)、特殊人群的药理学参数与药物代谢相关的分子标记、针对病原体生命周期分子靶点的直接作用药物研发、通过正向调控或负向调控药物的使用实现宿主导向抗结核精准治疗。本期刊登了3篇关于结核病耐药的综述。鉴于耐药结核分枝杆菌的补偿性进化是其传播与流行的基础,高谦课题组从结核分枝杆菌的耐药分子机制、耐药突变的适应性代价与补偿性进化,以及补偿性进化如何影响耐药结核病传播等方面进行了综述。袁莉课题组就近年来结核分枝杆菌“毒素-抗毒素系统”(TAS)与生物膜的研究及抗结核药物对生物膜形成的影响进行综述......     

非药物干预治疗神经精神疾病作用及机制研究

<正>近年来，随着非药物干预技术和方法的更新，其在治疗神经精神疾病中的作用及相关的机制也引起了广泛的关注。非药物干预包括运动、认知、经颅磁刺激、经颅电刺激，声光感觉刺激等^[1-4]。非药物干预在早期预防、减少药物副作用等方面存在优势。多项研究表明，非药物干预在预防和治疗脑缺血、阿尔茨海默病(Alzheimer’s disease,AD)、帕金森病、神经性疼痛、共情缺陷、意识障碍、物质使用障碍等神经精神疾病都有较好效果^[5-24]。     

可逆性后部脑病综合征发病机制进展及影像学表现

可逆性后部脑病综合征是一种与多种致病因素相关的临床影像学综合征,以头痛、癫痫发作、精神症状、视觉障碍、意识障碍为主要临床表现,影像学以顶枕叶可逆性脑白质病变为主。该病如果能够得到及时的诊断与治疗,大部分患者的临床症状及影像学改变可以消失;如果不能得到及时正确的诊疗,可能会发生一些不可逆的损伤,严重时甚至危及生命,因此加强对本病的认识、诊断及治疗至关重要。目前该病的发病机制尚不明确,现对其发病机制进展及影像学表现进行综述,以提高临床医师对该病的病理生理机制的认识及提高诊断水平。     

Cell:科学家发现罕见的亚型儿童脑瘤

正近日,来自圣犹大儿童医院等机构的研究人员通过研究,利用特殊的分子技术鉴别出了四种新型罕见的脑瘤,相关研究刊登于国际杂志Cell上,该研究或为后期开发更精准的诊断及治疗疗法来治疗相关癌症提供了新的线索。本文研究中,研究者对中枢神经系统原发性神经外胚层肿瘤(CNS-PNET)发生的遗传改变及其它分子特性进行了分析,这种罕见脑瘤常在儿童和成年个体中     

壳聚糖酶的克隆表达与壳寡糖的制备分析

目的:克隆壳聚糖酶基因于大肠杆菌中实现高表达,制备壳寡糖。方法:以枯草芽孢杆菌总DNA为模板扩增壳聚糖酶基因(CSN),克隆至载体pET23a(+)上,转化菌株BL21(DE3)。重组子经0.5 mmol/L IPTG诱导后,SDS-PAGE和质谱检测与鉴定重组酶。酶纯化后水解壳聚糖,薄层色谱分析其水解产物。结果:质谱证明壳聚糖酶(31.5kDa)成功表达,表达量占菌体总蛋白的45%左右。纯化后重组酶浓度为900 mg/L,纯度95%、回收率85%,酶活力为10 000 U/mg。壳聚糖降解产物为壳二糖至壳四糖。结论:原核表达载体pET23a(+)-CSN构建正确,壳聚糖酶表达量与活性高,适用于水解壳聚糖制备壳寡糖。     

国内外蝗害治理技术现状与展望

本文首先概述了国内外蝗虫发生与为害的态势,总结了现阶段我国蝗虫发生与为害的主要特点:即农田飞蝗暴发频繁而且严重,草原土蝗的发生时常造成严重的经济损失,而且侵入城市干扰市民生活,我国与周边国家之间蝗虫过境迁移频繁,使用化学农药污染环境和农产品;分析了国内外蝗虫防治对策与技术的发展现状,重点介绍了应急防治和可持续治理对策、...     

Kinetics and thermodynamics of peroxidase- and laccase-catalyzed oxidation of N-substituted phenothiazines and phenoxazines

N -substituted phenothiazines (PTs) and phenoxazines (POs) catalyzed by fungal Coprinus cinereus peroxidase and Polyporus pinsitus laccase were investigated at pH 4–10. In the case of peroxidase, an apparent bimolecular rate constant (expressed as k _cat/K _m) varied from 1 ×10⁷M⁻¹s⁻¹to 2.6×10⁸M⁻¹s⁻¹ at pH 7.0. The constants for PO oxidation were higher in comparison to PT. pH dependence revealed two or three ionizable groups with pK _a values of 4.9–5.7 and 7.7–9.7 that significantly affected the activity of peroxidase. Single-turnover experiments showed that the limiting step of PT oxidation was reduction of compound II and second-order rate constants were obtained which were consistent with the constants at steady-state conditions. Laccase-catalyzed PT and PO oxidation rates were lower; apparent bimolecular rate constants varied from 1.8×10⁵M⁻¹s⁻¹ to 2.0×10⁷M⁻¹s⁻¹ at pH 5.3. PO constants were higher in comparison to PT, as was the case with peroxidase. The dependence of the apparent bimolecular constants of compound II or copper type 1 reduction, in the case of peroxidase or laccase, respectively, was analyzed in the framework of the Marcus outer-sphere electron-transfer theory. Peroxidase-catalyzed reactions with PT, as well as PO, fitted the same hyperbolic dependence with a maximal oxidation rate of 1.6×10⁸M⁻¹s⁻¹ and a reorganization energy of 0.30 eV. The respective parameters for laccase were 5.0×10⁷M⁻¹s⁻¹ and 0.29 eV. Received: 20 September 1999 / Accepted: 24 February 2000     

Coiled-coil nanomechanics and uncoiling and unfolding of the superhelix and alpha-helices of myosin

The nanomechanical properties of the coiled-coils of myosin are fundamentally important in understanding muscle assembly and contraction. Force spectra of single molecules of double-headed myosin, single-headed myosin, and coiled-coil tail fragments were acquired with an atomic force microscope and displayed characteristic triphasic force-distance responses to stretch: a rise phase (R) and a plateau phase (P) and an exponential phase (E). The R and P phases arise mainly from the stretching of the coiled-coils, with the hinge region being the main contributor to the rise phase at low force. Only the E phase was analyzable by the worm-like chain model of polymer elasticity. Restrained molecular mechanics simulations on an existing x-ray structure of scallop S2 yielded force spectra with either two or three phases, depending on the mode of stretch. It revealed that coiled-coil chains separate completely near the end of the P phase and the stretching of the unfolded chains gives rise to the E phase. Extensive conformational searching yielded a P phase force near 40 pN that agreed well with the experimental value. We suggest that the flexible and elastic S2 region, particularly the hinge region, may undergo force-induced unfolding and extend reversibly during actomyosin powerstroke.     

Synthesis of hapten and conjugates of coumestrol and development of immunoassay

3-O-Carboxymethylcoumestrol was prepared as the hapten for immunoassay by a partial alkylation of coumestrol with ethyl chloroacetate in acetone alkalized with potassium carbonate. 3-O-Ethoxycarbonylmethylcoumestrol was separated by column chromatography and finally was hydrolyzed with formic acid. 1H and 13C NMR data (APT, COSY, HMQC, and HMBC) revealed that the reaction was regioselective, as 3-O-ethoxycarboxymethylcoumestrol was the only monosubstituted derivative. The hapten was then conjugated to bovine serum albumin and used for immunization of rabbits. A radioimmunoassay (RIA) system was established based on the polyclonal antiserum and a 125I-labeled hapten-tyrosine methyl ester conjugate as the radioligand. Parameters of the RIA: sensitivity: 12 pg per tube, 50% intercept: 140 pg per tube, working range: 20-4000 pg per tube. The cross-reactivity of a panel isoflavonoid and lignan phytoestrogens was either negligible (e.g. formononetin 0.07%; biochanin A 0.06%) or not detectable at all. The major immunoreactive peak in HPLC fractions from an alfalfa extract had the same retention time as coumestrol standard and represented 94.8% of the signal. The remaining 5.2% of immunoreactivity was distributed between five minor peaks. We conclude that after the validation for particular matrices, the method will be a useful tool for analysis of coumestrol, especially in low volume and low concentration samples.     

白术同源四倍体的诱导和鉴定及其与二倍体过氧化物酶的比较

以白术（Atractylodes macrooephala Koidz.）二倍体组培苗为材料,对其四倍体诱导方法进行研究,共获得45个白术同源四倍体株系,为优良株系的选育提供了材料。此外,还分析比较了其中8个白术四倍体株系与二倍体的过氧化物酶同工酶（POD）的酶谱差异,发现四倍体各株系过氧化物酶同工酶谱比二倍体的均多了Rf0.310的谱带,且总过氧化物酶比活力也发生了很大改变,对探讨白术四倍体优良株系的生理生化机理具有一定的参考价值。     

Effect of soil salinity and water stresses on growth and content of nitrogen,chloride and phosphate of wheat and triticale

Summary Three wheats and one triticale were grown, up to flowering stage, in pots on calcareous soil adjusted to a range of salinities (S₁=3.5, S₂=6, S₃=8.5, and S₄=11 mmhos/cm, 20°C, soilpaste extract) by adding solution consisting of 3∶2∶1 of Na-, Ca- and Mg chlorides in chemical equivalent amounts. Moisture in the pots was kept at 100% (W₁), 40% (W₂) and 20% (W₃) of the available water. The vegetative growth, nitrogen and phosphate were affected by S and W treatments, chloride was affected only by S. The interaction S×W affected only dry weight. Varietal effect was observed between wheat as a group and triticale. Multiple quadratic regression equations of these properties on salinity and water revealed that the higher the available water the wider the range of tolerable salinity. Triticale was relatively more tolerant to water stress. Salinity increases Cl and decreases N, whereas water stress enhances N accumulation to a certain extent. However, in triticale at S₃ and S₄ the effect of water stress on N was overshadowed by the excessive salinity. This did not occur for the wheat (Florence). P trends were described. R² for P was low (0.7435–0.3603) which made interpretations rather difficult.     

放牧对牧草光合作用、呼吸作用和氮、碳吸收与转运的影响

研究放牧对草地植物生理活动的影响,对于揭示草地放牧演替的生理机制有重要意义.大量研究表明,家畜放牧对牧草光合作用、呼吸作用以及C和N吸收与转运的影响,可以分为生理伤害和生理恢复2个阶段.放牧通过改变草地冠层结构影响牧草光合作用,净光合作用速率短期内迅速下降,随着叶面积指数增加又逐渐上升,呼吸作用有相似的变化趋势.牧草放牧后再生长所需的C和N最初主要来自根系和留茬中的贮藏物质,此后随着牧草生长恢复逐渐由同化作用供给,C代谢与土壤N水平负相关.放牧后牧草生理活动变化与牧草遗传特性、种间竞争、家畜放牧特征、非生物环境等因素密切相关.