皮肤组织显微共聚焦拉曼光谱成像研究

显微共聚焦拉曼光谱成像技术(Confocal Raman Microspectroscopy Imaging,CRMI)能够对样品微区进行精确无损的拉曼光谱分析和光谱图像扫描,提供生物样品的无损高分辨光学信息。本项研究工作,利用CRMI技术实验获取了正常人体离体皮肤组织的拉曼光谱特征,并结合典型特征峰的扫描图像,探讨了脂类、蛋白质等成分在皮肤真皮层的分布特点。实验发现皮肤组织真皮层内胶原蛋白的拉曼特征峰1 248 cm-1强度及其空间分布尤为突出,这一实验结果与组织学中胶原纤维占真皮结缔组织95%的事实相符。实验结果显示,CRMI技术能够全面诠释生物组织内部生化组成与分布信息,在实验描述皮肤组织病理变化的分子生物学机制方面具有广阔的应用前景。     

拉曼光谱在皮肤领域的研究进展

拉曼光谱是一种新型的光学检测技术,常用于材料鉴定。近年来,随着无创检测需求的增加,拉曼光谱逐渐应用于疾病诊断、物质鉴别等生物领域。综述了拉曼光谱在皮肤领域的研究进展,及其对皮肤组织成分鉴别和皮肤疾病诊断的价值,以期推动拉曼光谱广泛应用于皮肤病学的机理研究和临床诊断。     

菹草红色类胡萝卜素的拉曼光谱特性研究

用MgO 硅藻土 (1∶2 ,w/w)柱层析和硅胶G薄层层析 (TLC)从菹草中分离纯化了三种红色素r1、r2和r3,其极性大小排序依次为 :虾青素 >r1>r2 >r3>角黄素 >β 胡萝卜素。以虾青素和 β 胡萝卜素为对照 ,运用显微拉曼技术对它们作了测试分析研究。在拉曼光谱的“指纹区”(<180 0cm-1) ,r1、r2和r3都在 15 2 7cm-1处有最强的特征谱线 ,对应的是c=c伸缩振动 (υc=c) ,r1在 116 2cm-1、r2和r3在 115 7cm-1有较强的特征谱线 ,对应的是c c伸缩振动(υc c) ,r1、r2和r3在 10 0 7cm-1有较强的特征谱线 ,对应的主要是甲基与碳链之间的摇摆振动 ;r1、r2和r3与虾青素及 β 胡萝卜素在 2 0 0 0— 4 0 0 0cm-1区也有很好的对应关系。实验结果充分证明菹草红色素r1、r2和r3属于类胡萝卜素化合物 ,r1、r2和r3之间及与虾青素和 β 胡萝卜素的拉曼光谱都存在差异 ,说明它们的细微结构不同 ,其具体结构有待进一步研究。     

正常和癌变胃粘膜组织的共焦拉曼光谱初探

目的:分析研究胃正常和癌变粘膜组织的拉曼光谱特征,为拉曼光谱应用于胃癌的临床检测诊断奠定基础。方法:收集胃镜检查中活检的19例正常和12例癌变胃粘膜组织标本,采用785 nm激发光拉曼光谱仪进行拉曼光谱采集。比较分析胃正常和癌变粘膜组织的拉曼光谱特征差异并研究其区分正常和癌变组织的价值。结果:1)特征峰1 098 cm-1、1 444 cm-1、1 555 cm-1、1 660 cm-1等在胃癌组织中发生了移位,平均位移(2.57±1.28)cm-1,以红移为主;2)癌变组织中相对峰强比I1087 cm-1/I1207 cm-1≥1.87,其区别胃癌和正常胃粘膜组织的准确率、灵敏度和特异度分别为87.1%、83.3%、89.5%;3)癌组织中增加了表征蛋白质的特征峰1 262 cm-1、1 586 cm-1,但同时减少了表征蛋白质和脂质特征峰1 172 cm-1。结论:拉曼光谱不仅可以准确区分正常和癌变,而且可以探索癌变相关的分子生化改变。拉曼光谱在胃癌的跟踪发现和检测诊断中具有良好前景。     

生物组织拉曼光谱数据的统计分析

拉曼光谱技术在生命科学领域已取得较为广泛的研究与应用,如何从低信噪比、质量差的拉曼光谱信号提取并充分利用谱图中所含信息,对光谱后续分析、样品的归类等至关重要.本文首先明确了生物组织拉曼光谱统计分析中几个重要的概念,进而对拉曼光谱数据的预处理,光谱分析研究中较为常用的几种多元统计方法进行了归纳、对比与分析.     

二甲基亚砜对P19细胞体外分化为心肌细胞的影响

体外应用不同浓度二甲基亚砜(dimethyl sulfoxide,DMSO)诱导P19细胞向心肌细胞分化,通过免疫细胞化学、流式细胞、RT-PCR方法检测α-横纹肌肌动蛋白(α-sarcomeric actin,α-SA)、心肌肌钙蛋白T(cardiac troponin T,cTnT)及GATA-4、α-肌球蛋白重链(α-myosin heavy chain,α-MHC)mRNA表达。结果显示,DMSO处理结合悬浮培养可诱导部分P19细胞分化为节律跳动的心肌细胞,分化的细胞α-SA、cTnT表达阳性,同时表达心肌特异GATA-4、α-MHCmRNA。1.0%DMSO组α-SA、cTnT阳性细胞免疫荧光强度及GATA-4、α-MHCmRNA表达水平明显高于0.5%及0.8%DMSO组。表明DMSO的诱导作用与其浓度有关。     

褪黑素对癫痫病作用的激光拉曼光谱研究

分别对正常状态,癫痫状态以及癫痫状态注射褪黑素后的Wistar大鼠的大脑皮质上清液样品进行了拉曼光谱分析.研究表明三种样品的拉曼特征峰分别为波数1 654 cm-1、1 623 cm-1及1 632 cm-1.它们有明显的区别.癫痫状态样品光谱在波数1 654 cm-1位置幅值有所减小;注射褪黑素样品光谱在波数1 654 cm-1位置幅值有所增加,证明褪黑素对癫痫病有抑制作用.     

二甲基亚砜对秀丽线虫运动、个体发育和生殖的影响

本研究探讨了不同浓度二甲基亚砜(dimethyl sulfoxide, DMSO)对秀丽线虫运动、个体发育以及生殖的影响。结果显示:DMSO浓度≥2.5%时,线虫咽泵运动次数显著下降;DMSO浓度≤0.5%时,线虫头部摆动次数显著增加;DMSO浓度≤2.5%时,线虫体长和体宽无明显影响,浓度为5.0%时,抑制线虫个体发育作用明显;DMSO浓度0.5%,线虫子宫内怀卵数增加,而后代数目减少;各试验浓度DMSO对单侧性腺臂卵母细胞数目均无显著影响。综上所述,DMSO对秀丽线虫具有一定毒性作用,且对不同指标产生毒性的浓度阈值不同,在以线虫为模型的药物研究中,为排除DMSO对线虫的毒性作用给试验结果造成的影响,助溶剂DMSO的最佳使用浓度应为0.5%,本研究为今后对秀丽线虫的研究提供研究数据。     

光镊捕获的单个解冻人血红细胞的拉曼光谱研究

红细胞的冰冻与解冻的实施为血液的长期保存提供了有效的方法。在过去的几十年中,红细胞冻存有过数种方法,其中高甘油冻存法比较普遍,因而用此方法保存红细胞是否对红细胞产生了影响及产生了什么影响是值得研究的。作者利用激光光镊拉曼光谱系统,通过拉曼光谱对冻存人血红细胞进行研究;结果显示,红细胞冻存前后的拉曼光谱有一定的变化,解冻提取后也产生了一定的变化,这些变化主要体现在对应拉曼光谱的位置和强度上。研究结果对进一步研究红细胞的冻存具有一定的参考价值。     

Effects of Dimethyl Sulfoxide on Tetrahymena pyriformis GL. Fine Structural Changes and Their Reversibility*

SYNOPSIS. Fine-structural changes are induced in Tetrahymena by exposure to 7.5% dimethyl sulfoxide (DMSO) in the presence of growth medium. Some of these changes (nucleolar, mitochondrial, peroxisomal) resemble those seen during starvation, in agreement with the previously reported inhibitory effect of DMSO on food-vacuole formation; however, changes such as helical formations of polyribosomes indicate additional internal actions of the reagent. The effects vary to some extent within the same group of cells, suggesting that sensitivity to the reagent may differ with the stage in the cell cycle. The structural changes induced by a 1-hr exposure to DMSO are reversible, but recovery of the cells after removal of the reagent is slower than that seen after starvation. The observations suggest that the recovery is associated with renewed synthesis.     

The effect of hycanthone and maleic hydrazide on the frequency of micronuclei in the bone-marrow erythrocytes of mice.

Male Swiss mice were assigned to 6 groups of either 3 or 4 animals each. 3 groups were given hycanthone methanesulfonate intraperitoneally, at 40, 80 or 120 mg/kg, respectively; the dose was repeated after an interval of about 24 h. At the same time 2 groups received maleic hydrazide at 100 or 200 mg/kg, and the remaining group was given dimethyl sulfoxide which was used as a solvent for both drugs. 6 h after the second injection, the mice were killed and bonemarrow preparations were made. Hycanthone induced a significant increase in the frequency of micronuclei in the polychromatic erythrocytes and suppressed the P/N ratio significantly. However, there was no dose-response relationship. Maleic hydrazide, on the other hand, failed to influence the incidence of micronuclei or the ratio of poly- to normo-chromatic erythrocytes.     

二甲基亚砜对生物膜的作用机理

二甲基亚砜被广泛应用于生物、化学和药学领域,这些应用大多与其增加生物膜的通透性、促进活性分子跨膜传输的作用密切相关。本文对二甲基亚砜增加生物膜通透性的理论及实验研究做简要综述,主要强调二甲基亚砜在生物膜中诱导水性孔道形成的分子动力学模拟及其相关的实验研究。     

Effects of methylation and ring size on mutagenicity of cyclic nitrosamines in Drosophila melanogaster

The mutagenic activity of 7 nitrosopiperazines, 2 nitropyrrolidines, and 3 nitrosomorpholines was examined in the X-linked recessive-lethal assay of Drosophila melanogaster. Mutagenicity is also reported for a series of cyclic nitrosamines that differ in structure only in the number of carbon atoms in the ring. Of the 18 compounds tested, 6 (nitrosopiperazine; 2,3,5,6-tetramethyl-dinitrosopiperazine; nitrosoproline; 2,5-dimethylnitrosopyrrolidine; nitrosothiomorpholine; and nitrosooctamethyleneimine) were nonmutagenic. As we reported earlier in investigations with the nitrosopiperidines, substitutions with methyl groups at all of the α-carbon atoms reduce or eliminate the mutagenic activity of dinitrosopiperazine and nitrosopyrrolidine.     

Dimethyl sulfoxide-induced high enantioselectivity of subtilisin Carlsberg for hydrolysis of ethyl 2-(4-substituted phenoxy)propionates

The enantioselectivity for subtilisin-catalyzed hydrolysis of ethyl 2-(4-substituted phenoxy)propionates in an aqueous buffer solution was improved by addition of DMSO (54–56% v/v). On the basis of the conformational change of subtilisin Carlsberg observed for FT-IR and CD spectra, the high enantioselectivity for subtilisin-catalyzed hydrolysis of racemic ethyl 2-(4-ethylphenoxy)propionate could be related to a partial decrease of the tertiary structure of the enzyme protein arising from an increase of the ratio of DMSO in the reaction medium. This mechanistic model for the enantiorecognition can also be supported by the discussion based on the value of the Michaelis constant (K_m) obtained for each enantiomer of the substrate.     

Genetic activity of niridazole in yeast.

Niridazole, one of several drugs presently known to be of value in the treatment of human schistosomiasis, was tested for its activity in inducing mitotic recombination in yeast. It was found that niridazole is genetically active when the treatment of yeast cells is performed in a rich medium (YPG-medium) under growing conditions, but not when treatment is carried out in a non-nutrient suspension (phosphate buffer). The data suggest that niridazole might be converted to an active compound by yeast metabolism. The results of the experiments with niridazole in the non-nutrient medium were compared with those of AF-2 and SQ18, 506, two agents which have been shown to be genetically active in the present assay system.     

喇曼光谱技术在生物医学中的应用

喇曼光谱技术是一种非侵入、非弹性散射技术,能够在分子层次上探测物质的临床医学特征和结构特征。本文综述了近十年来喇曼光谱技术在生物医学中的最新发展,归纳出了四种目前在生物医学中最为活跃的喇曼光谱技术：近红外喇曼光谱、紫外共振喇曼光谱、表面增强喇曼光谱和多维喇曼成像技术。详细阐述了这四种技术的特点和适用范围,并且列举了丰富的成功范例。     

Differential effect of recombinant human leukocyte interferon on human leukemic and normal myeloid progenitor cells

Two separate clones of recombinant leukocyte interferon (IFLrA and IFLrD) inhibited the cloning efficiency in soft agar of the human leukemia cell lines HL-60 and KG-1. Inhibition of the growth in agar of normal human bone marrow myeloid progenitors was also observed, but this required considerably higher concentrations. IFLrA and IFLrD also inhibited the growth of HL-60 and KG-1 cells in suspension culture. This antiproliferative effect did not appear to be due to induction of maturation of these cells. Our results suggest that homogeneous preparations of interferon may be capable of exerting selective antiproliferative effects on malignant human myeloid progenitor cells in comparison to their normal counterparts.