X射线和~(60)Coγ射线辐照食管癌细胞的拉曼光谱研究

食管癌细胞(EC9706)经不同剂量X射线和60Coγ射线辐照后继续培养24h,利用激光拉曼光谱分析EC9706细胞内部蛋白质、核酸、脂类等生物大分子的构象和含量变化。分析发现,两种放射源各剂量组拉曼光谱的峰强和频移与空白对照组之间都存在较大的差异。主要表现为(1)X射线辐照后,对照组光谱中存在的某些谱带,个别剂量组中该谱带却消失。蛋白质主链中骨架C-N振动引起的1114 cm-1谱带在各剂量组中普遍消失,膜脂中膜结合β-胡萝卜素的C=C振动谱带1523 cm-1仅存在于6Gy组。(2)60Coγ射线辐照后,蛋白质酰胺Ⅲ带在中等剂量(4、5Gy)组中β折叠结构向无规卷曲转化,大剂量组中DNA中的磷酸二酯(O-P-O)基团的非氢键化程度增强。拉曼特征峰在不同剂量组中的变化,为进一步从物理能级结构角度研究X射线和60Coγ射线对EC9706细胞的辐照损伤机制提供了实验依据。     

12C和X射线辐照人肺癌细胞H1299的生物学效应

用高传能线密度（LET）的12C离子束和低LET的X射线辐照体外培养的非小细胞肺癌H1299(p53基因缺失), 研究它们的辐照生物学效应的差异。 用克隆形成率法测定了细胞对射线的辐射敏感性; 用AnnexinV/PI试剂盒检测了细胞早期凋亡; 用流式细胞仪检测了细胞周期变化。 实验结果表明, 12C离子束辐照H1299细胞的存活率明显低于用X射线辐照的; 12C离子束引起H1299细胞的早期凋亡率明显高于X射线辐照引起的, 且持续时间更长; 12C离子束引起的H1299细胞G2/M期的抑制更明显。 说明H1299细胞对高LET的12C离子束的辐射敏感性高于对X射线的, 重离子对p53基因缺失型肿瘤的治疗可实施较低的照射剂量、 较少的照射次数和较长的时间间隔。     

^12C和X射线辐照人肺癌细胞H1299的生物学效应

用高传能线密度（LET）的^12C离子束和低LET的X射线辐照体外培养的非小细胞肺癌H1299（p53基因缺失）,研究它们的辐照生物学效应的差异。用克隆形成率法测定了细胞对射线的辐射敏感性;用AnnexinV/PI试剂盒检测了细胞早期凋亡;用流式细胞仪检测了细胞周期变化。实验结果表明,^12C离子束辐照H1299细胞的存活率明显低于用X射线辐照的;^12C离子束引起H1299细胞的早期凋亡率明显高于X射线辐照引起的,且持续时间更长;^12C离子束引起的H1299细胞G2/M期的抑制更明显。说明H1299细胞对高LET的^12C离子束的辐射敏感性高于对X射线的,重离子对p53基因缺失型肿瘤的治疗可实施较低的照射剂量、较少的照射次数和较长的时间间隔。     

低剂量电离辐射预处理对不同肿瘤细胞周期的影响

实验研究了低剂量γ射线预照射对人肝癌细胞系hepG2和人宫颈癌细胞系HeLa的细胞周期进程的影响.结果显示(1)低剂量(5cGy)辐射后,两种细胞的G2/M期细胞短暂累积;(2)低剂量辐射促进肿瘤细胞的生长;(3)高剂量(3Gy)辐射后,hepG2细胞发生G2期阻滞,HeLa细胞发生S期和G2期阻滞;(4)与单纯高剂量照射相比,低剂量辐射预处理后4h,再给予高剂量辐射,可进一步促进hepG2细胞在G2/M期累积,但是预照射对HeLa细胞的周期进程没有明显影响.因此,低剂量辐射预处理对高剂量诱导的细胞周期阻滞的影响依赖于肿瘤细胞的类型.     

12C6+离子预辐射对小鼠胸腺脾脏细胞周期进程的影响

以0, 0.05, 0.1, 0.25, 0.5 Gy 12C6+ 离子全身预辐照昆明小鼠, 间隔4 h后再对小鼠进行4 Gy全身辐射。 辐照后12 h用流式细胞仪检测小鼠胸腺脾脏细胞在各细胞周期时相的百分率, 同时用单细胞电泳检测受辐射小鼠胸腺脾脏细胞DNA损伤程度。 结果显示, 相对于大剂量预照射组, 各低剂量预照射组胸腺细胞S期细胞百分率显著减少; 脾脏细胞G0/G1期细胞百分率明显减少; 同时胸腺脾脏细胞的拖尾率及拖尾长度明显减少, 以0.1 Gy预辐照效果最为明显。 这些结果表明, 低剂量预辐射处理可以减弱胸腺细胞的S期阻滞及脾脏细胞的G1期阻滞, 并明显减轻胸腺脾脏细胞的DNA损伤程度。     

准分子激光辐照PVDF的拉曼和红外光谱研究

通过测量KrF准分子激光辐照前后PVDF的拉曼光谱和红外光谱,分析了PVDF经激光辐照后表面电导率大幅度提高的机理;采用逐点扫描拉曼成像技术,确定出激光辐照后PVDF的导电层厚度约为7.5μm。在拉曼光谱、扫描电镜和X射线能谱综合表征基础上,发现激光辐照后PVDF表面呈现出复合型微结构。     

羧甲基-β-1,3-葡聚糖对人肝癌HepG2细胞的放射增敏作用

本研究旨在探讨羧甲基-β-1,3葡聚糖（CMG）对人肝癌HepG2细胞X射线或12C6+离子束辐射敏感性的影响。首先用CCK-8法检测CMG对HepG2细胞的生长抑制情况,得到半数抑制浓度（IC50）为120.6μg/mL。用浓度为0.1×IC50的CMG预处理HepG2细胞24 h,再给予2 Gy X射线或12C6+离子束辐照（CMG+辐照组）;CMG未处理组直接接受2 Gy X射线或12C6+离子束辐照（辐照组）。对比分析辐照组和CMG+辐照组细胞的克隆存活、DNA损伤、凋亡与周期分布、细胞内活性氧（ROS）水平。发现:与X射线辐照组相比,相同剂量的12C6+离子辐照组克隆存活率更小,DNA损伤和周期阻滞更加严重,细胞凋亡率和细胞内ROS水平也更高。与单独X射线或12C6+离子束辐照组相比,CMG+辐照组克隆存活率明显降低,细胞凋亡率随辐照后CMG作用时间的延长而明显增加,CMG使辐照后细胞内ROS维持在一个较高的水平,同时CMG明显加重了单独辐照诱导的DNA损伤和周期阻滞。结果表明,与X射线相比,HepG2细胞对相同剂量的12C6+离子辐射更敏感;CMG可增加HepG2细胞对X射线或12C6+离子辐射的敏感性;CMG可能通过增加受照HepG2细胞内的ROS水平,加剧辐照诱导的DNA损伤,促进辐射诱导细胞凋亡而起到辐射增敏作用。This study aims to investigate the effect of carboxymethy-β-1, 3-glucan (CMG) on the sensitivity of human hepatoma HepG2 cells to X-rays or 12C6+ ions irradiation. First, the inhibitory effect of CMG on the growth of HepG2 cells was detected by CCK-8 assay, and the half maximal inhibitory concentration (IC50) was 120.6 μg/mL. HepG2 cells were pretreated with CMG at a concentration of 0.1×IC50 for 24 h and then irradiated with 2 Gy X-ray or 12C6+ ion beams (CMG + irradiation group). CMG untreated group was directly irradiated by 2 Gy X-rays or 12C6+ ions beam (irradiation group). The clone survival, DNA damage, cell apoptosis, cell cycle distribution, and intracellular reactive oxygen species (ROS) levels in irradiation group and CMG + irradiation group were comparatively analyzed. The results showed that the clone survival rate was lower, DNA damage and cycle arrest were more serious, and the rate of apoptosis and intracellular ROS levels were higher in 12C6+ ions irradiation group than those in the same dose of X-rays irradiation group. Compared with X-rays or 12C6+ ions irradiation group, the clone survival rate of CMG + irradiation group was significantly decreased, and the apoptosis rate significantly increased with the prolongation of CMG treatment post-irradiation; CMG maintained intracellular ROS at a higher level after irradiation, CMG also significantly aggravated radiation-induced DNA damage and cycle arrest. These results indicated that HepG2 cells were more sensitive to 12C6+ ions radiation than those at the same dose of X-rays. CMG increased the sensitivity of HepG2 cells to X-rays or 12C6+ ions irradiation by increasing intracellular ROS level, exacerbating radiation-induced DNA damage and promoting radiation-induced apoptosis in irradiated HepG2 cells.     

辐照诱导的人正常肝细胞系HL-7702细胞延迟效应

利用X射线辐照人正常肝细胞系HL-7702细胞, 运用胞质分离阻滞微核法实验检测细胞微核率,AnnexinV FITC细胞凋亡检测试剂盒检测细胞凋亡率, 细胞微核率和凋亡率随着辐照剂量的增加而显著增加。X射线照射后细胞传代培养, 第7代时不同剂量辐照后子代细胞微核率和凋亡率同未辐照细胞相比已无明显区别。 对不同剂量辐照后传代7代的细胞再次照射2.5 Gy的相同剂量,发现它们细胞微核率和凋亡率存在明显差异,即初次受辐照剂量高的细胞, 再次以相同剂量辐照后的微核率和凋亡率也高. 这些结果表明,X射线辐照导致了HL-7702细胞基因组不稳定性这一辐射延迟效应,再次辐照使得辐射的延迟效应得以明显的表现。 Human normal liver cell line HL-7702 cells were irradiated with different doses of X rays. Micronucleus and apoptosis rates in the irradiated cells were measured with cytokinesis block micronucleus method and Annexin V FITC apoptosis detection kit, respectively. Experimental data showed that the micronucleus and apoptosis rates increased obviously with increasing irradiation dose. After seven population doublings, the micronucleus and apoptosis rates of the cells surviving exposure to the X rays reduced to the same levels as non irradiated control cells; the progenies of the cells were secondly exposed to X rays at the same dose of 2.5 Gy. We found that the progenies of the cells surviving the first irradiations of the various doses showed markedly differential micronucleus frequencies and apoptotic rates. Although the same dose of 2.5 Gy was applied in the second irradiations, the micronucleus frequencies and apoptotic rates of the progenies of the cells initially exposed at higher doses were significantly higher than the others. These results indicate that X rays lead to genomic instability in HL 7702 cells, which is an important manifestation of radiation induced delayed effect, and a second radiation stimulus makes the delayed effect in the progeny of the previously irradiated cells be expressed obviously.     

高功率毫米波辐照对小鼠皮肤组织拉曼光谱的影响

运用显微激光拉曼仪测定了正常小鼠离体皮肤0～300 μm不同深度的拉曼光谱。实验还测定了8 mm辐照一定时间后小鼠受辐照皮肤组织的拉曼光谱。实验结果表明毫米波辐照后皮肤拉曼光谱峰位857,936,1 658 cm-1的相对强度随着辐照时间的增加而减少。这表明由于毫米波热效应皮肤组织中的胶原蛋白构象发生了改变甚至分解,从而进一步表明皮肤组织受到了不可恢复的损伤。     

呼吸缺陷型酵母菌株的离子束辐射敏感性研究

选取一株由离子束辐照诱变获得的呼吸缺陷型酵母菌株，研究其在不同离子辐照剂量范围的辐射敏感性。结果发现，呼吸缺陷型酵母菌株因其线粒体及线粒体DNA发生突变，在离子束辐照时，在低剂量区域表现出较高辐射敏感性，在高剂量区则表现出对于辐射的抗性。     

微束技术在放射生物学中的应用

微束装置可以为生命科学研究提供微米定位、剂量特定的电离辐射,在生物体内的电离辐射靶物质及其敏感度、靶物质的损伤及修复机制研究中具有独特的作用。概述了生物微束装置和实验技术的发展及其在低剂量辐射效应、旁观者效应、信号传导研究中的主要应用;介绍了中国科学院近代物理研究所（IMP）重离子微束装置,该装置可以提供能量7~ 80 MeV/u、传能线密度为30~ 3000 keV/μm的重离子微束,实现了活细胞辐照和在线观察、小鼠定位辐照的实验技术;利用IMP微束装置在重离子诱导旁效应实验、小鼠下丘脑重离子辐照效应和DNA损伤快速修复动态等方面取得了一些实验成果。The microbeam facility can provide micrometer scale localized and predefined ionizing radiation in the life science study, and the microbeam techniques play a unique role in determining the target substances of ionizing radiation, as well as in the study of radiation sensitivity, mechanisms of radiation damage response and repair. This paper summarizes the technical developments of biological microbeam facilities and their applications in the studies of low-dose radiation effect, bystander effect and cellular signaling. This paper also introduces the recent developments at the heavy-ion microbeam facility in the Institute of Modern Physics (IMP), which can provide heavy ion microbeam irradiation with energy of 7~80 MeV/u and LET of 30~3000 keV/μm. The facility can perform radiobiological irradiation and online investigation in living cells and mice, including bystander effect study, sleeping system influence after irradiation to mice hypothalamus and the recruitment dynamics of XRCC1 protein.     

Inhomogeneous depth distribution of fluorine atoms in PVDF upon radiative carbonization

Under the action of ionizing radiation on a PVDF film, fluorine and hydrogen atoms bound to its linear carbon chain with single chemical bonds detach. Free atoms and HF molecules diffuse toward the film surface and escape from it. As a result of irradiation of the sample surface, a fluorine concentration depth profile arises. The fluorine distribution in the PVDF films subjected to long-term X-ray exposure was studied using X-ray photoelectron spectroscopy and Rutherford backscattering spectroscopy. Both methods yield close values of the fluorine concentration at a depth of ～10 nm.     

Monitoring radiation induced alterations in biological systems,from molecules to tissues,through infrared spectroscopy

Humans can be exposed to non-ionizing and ionizing radiation for diagnostic, therapeutic, accidental, and occupational reasons. Consequently, the effect of radiation on biological systems has attracted the attention of researchers for a rather long time. This review is about the mid-infrared Fourier Transform Infrared (FTIR) spectroscopic characterization of non-ionizing and ionizing radiation-induced changes in DNA, lipids, and proteins, as isolated or synthetic macromolecules, and in biological membranes, cells, and tissues. Here, the context of radiation was limited with electromagnetic radiation including gamma rays. The review first outlines introductory information about non-ionizing and ionizing radiation and their interaction with biological systems. Afterwards, FTIR spectroscopy and spectroscopic analysis are briefly discussed. Finally, FTIR spectroscopic analysis of DNA, lipids, proteins, membranes, cells, and tissues that were exposed to radiation are presented. The findings show that FTIR spectroscopy can be successfully used as a novel method to monitor radiation-induced alteratios in biological systems.     

芬太尼类物质的振动光谱特征分析研究

通过分析28种芬太尼类物质的红外和拉曼光谱,研究了芬太尼类物质的振动光谱特征,考察了红外和拉曼光谱对芬太尼类物质的区分能力。整体上看,芬太尼类物质的红外和拉曼光谱表现出不同的光谱特征,具有互补性。在红外光谱中,不同盐型芬太尼类物质在3200～2 000 cm-1区间差异显著,碱型化合物在2 972～2 952 cm-1存在强的吸收峰,盐酸盐化合物在2 600～2 320 cm-1存在中等强度的多重吸收峰,枸橼酸盐化合物在3 100～2 800 cm-1存在中等偏弱的宽吸收峰。在红外光谱中,芬太尼类物质在1 750～1 630 cm-1存在由C═O键伸缩振动引起的强吸收峰,在710～680 cm-1存在由苯环面外弯曲振动引起的强的单峰或双峰。在拉曼光谱中,28种芬太尼类物质均在1 001～1 002 cm-1处有强的拉曼峰,该峰是由苯环上C-H键的面内弯曲振动引起的。含烷基、苯基、四氢呋喃基取代化合物的拉曼光谱中,1 000 cm-1左右位置的峰为基峰,其他峰的强度均低于基峰强度的30%;含氟、呋喃、硫代等取代基化合物的拉曼光谱中,除1 000 cm-1左右位置的峰外还有其他高强度的峰。红外光谱可用于区分所有芬太尼类物质,对绝大多数化合物区分度高,对个别结构相差一个甲基的芬太尼结构类似物的区分度较弱,但通过指纹区的特征吸收峰,也可实现区分。当不存在荧光干扰时,拉曼光谱可用于区分所有的芬太尼类物质,对绝大多数化合物区分度高,对部分结构相差一个甲基或不同位置甲基取代的芬太尼结构类似物的区分度较弱,但通过指纹区的特征峰,也可实现区分。红外光谱和拉曼光谱均具有无需样品前处理、测试速度快、检测成本低、绿色环保等优点,便携式设备可用于现场快速检验。拉曼光谱仪测定某些样品时会受到荧光干扰,具有一定的局限性。与拉曼光谱相比,红外光谱无荧光干扰、谱图一致性高、商业谱库更加完备,是现场快速定性分析的首选方法。     

The influence of DNA inhibitor synthesis on the induction and repair of double-strand DNA breaks in human lymphocytes under action of radiation with a different linear energy transfer

The influence that inhibitors of repair and replicative DNA synthesis, 1-β-D-arabinofuranosyl-cytosine and hydroxyurea, have on the formation and repair kinetics of double-strand breaks (DSBs) in peripheral human blood lymphocytes under the influence of radiation with a different linear energy transfer (LET) (gamma quanta and accelerated heavy ions) is studied. It is demonstrated that lithium and boron ions with LETs of 20 and 40 keV/μm, respectively, possess higher biological effectiveness with respect to the DNA DSB induction criterion. The value of the relative biological effectiveness of accelerated lithium and boron ions is 1.5 ± 0.1 and 1.6 ± 0.1, respectively. It is found that, upon cell irradiation by gamma quanta in the absence of inhibitors, efficient DNA DSB repair is observed during incubation. Under the conditions of cell incubation and in the presence of inhibitors, some growth in the number of DNA DSBs, rather than a reduction, is observed after 5-h incubation. In the case of the action of accelerated boron ions (as well as gamma quanta), under normal conditions, the efficient repair of induced DNA lesions takes place. Unlike the action of gamma quanta, in the case of cell incubation in the presence of radiomodifiers, the number of induced DNA DSBs falls. These results may testify to the fact that the repair of double-strand DNS breaks takes place under the action of ionizing radiation with a different LET on mammalian cells in the presence of DNA synthesis inhibitors Ara-C and HU. It is concluded that, for cells subject to gamma irradiation, no DNA DSB repair is observed due to the large contribution of single-strand incision DNA breaks formed in the postradiation period in the course of excision nucleotide repair.     

人全血的毛细管显微拉曼光谱分析

血液中含有众多生物信息,如激素、酶、抗体等丰富的蛋白质成分。通过对血液中众多生物信息进行检测鉴定可以起到对该血液种属判定、溯源的目的。因此,血液检测技术的发展在诸如刑事案件侦破、物种鉴定、疾症预防等领域具有重要意义。目前,传统血液检测手段多为显微观测、免疫法、DNA/基因检测法等,这些技术会对血液样本造成不可逆转的破坏性,且存在分析周期长、结构装置复杂、试验价格昂贵等问题。随着激光技术的发展,拉曼光谱技术作为一种非线性散射光谱技术,在血液检测技术中得到了应用。在血液检测技术中,拉曼光谱技术通常与共聚焦显微系统结合,对涂在载玻片上或盛放在透明容器中的血液样品进行光谱信号采集。该技术具有快速、无损等优势,但复杂的光路系统及昂贵的实验装置限制了该技术的广泛推广。为提出一种装置简单、操作简便的血液拉曼检测新技术,研究采用基于毛细管的显微拉曼技术方案采集并分析人全血的拉曼信号。血液样品通过毛细管的虹吸效应取样,与载玻片的涂样方式相比毛细管的方案具有模拟人血管、维持血液活性、减小空气对实验过程中血液成分的影响、降低激光对血液样品的灼伤效果等优势。为避开可见光部分荧光较强区域的荧光干扰,研究采用360 nm紫外激光器作为激发光源,防止可见荧光信号的干扰。积分时间设为800 ms,有效避免因激光长时间照射对血液样品的灼伤效果,影响实验数据的稳定性与真实性,光谱平均次数为2次,避免单次测量所带来的数据的不准确性影响。光谱扫描范围为500～1 800 cm-1, 结果表明此范围内可较好的避开可见光部分荧光较强区域的干扰。测得的拉曼光谱信号通过滤波去噪及基线校正进行处理。首先采用5阶离散小波变换滤波,进行1层信号分解,滤除高频噪声信号,保留低频有效信号,从而去除杂散信号,对光谱有效信号进行提取。其次,采用4阶多项式拟合扣除基底的基线校正,实现人全血的毛细管显微拉曼光谱峰值信号的提取。最终,通过查询SDBS数据库以及人血样本通过reishaw共聚焦显微拉曼光谱仪测量所得光谱图进行验证发现测得信号中部分为人体内数种氨基酸成分的拉曼信号。实验研究发现,基于毛细管的显微拉曼实验系统与常规拉曼探头实验系统相比,拉曼信号更稳定、重复性高,可有效提取人全血中的拉曼光谱信号, 而其与高精度的共聚焦显微拉曼系统相比价格便宜、结构简单、易于推广等优点,但信号信噪比、有效信号的峰值强度上仍有进一步的提升,是一种测量人全血拉曼信号的可行方案。     

基于拉曼光谱方法研究不同剪切力下的红细胞亚损伤

利用共聚焦拉曼光谱技术,对人工心脏泵不同剪切应力下受到亚损伤的红细胞进行实验研究,验证拉曼光谱对红细胞亚损伤程度的评估能力,为血液损伤评价提供了一种新的思路。实验采集血红蛋白和红细胞的拉曼光谱标准谱图并进行对比分析,以确定红细胞谱图特征峰的归属。用血液剪切力试验平台对测试血样施加暴露时间为1 s,大小分别为0,50,100,150,200,250和300 pa的剪切力。利用共聚焦拉曼仪器,在10倍长焦物镜,532 nm激光光源波长,积分时间10 s,积分次数2次,2.5 mW功率下采集剪切应力作用后的红细胞拉曼谱图。通过归一化的方法对比红细胞的拉曼谱图变化,评估红细胞亚损伤的程度,运用曲线拟合方法对特征峰和剪切应力进行拟合,验证拉曼光谱对红细胞亚损伤的评估能力。对比血红蛋白和红细胞的拉曼光谱标准谱图发现,红细胞谱图能够反映血红蛋白的内部结构。且结果表明,拉曼光谱法可以用于区分不同剪切应力下亚损伤的红细胞,推断剪切应力可以透过细胞膜从而影响到其内部的血红蛋白结构。且随着剪切力的增大,1 376 cm-1位置左侧谱线呈现明显抬高趋势,1 549和1 604 cm-1位置的峰强增高,1 639 cm-1位置的氧浓度标记带ν₁₀振动谱带减弱。其中1 549 cm-1位置的峰强为亚铁离子高自旋带,在不同剪切力的作用下,峰强差异表现最明显,与剪切应力呈明显的正向线性关系,拟合效果良好。拉曼光谱法检测样本处理简单、耗时短、操作简便、重现性好,且可以精确的检测到细胞内部结构的细微变化,可以评估红细胞的亚损伤程度,弥补了传统评价溶血的方法的不足,为人工心脏泵血液损伤评价提供了新的技术手段,拓宽了拉曼检测方法的应用领域。     

Raman spectroscopic investigations on the interactions of gastric cancer cells with 5-fluorouracil

To study the efficacy and side effects of antitumor drug by the method of Raman spectroscopy, the cancerous (SGC-7901) and normal (GES-1) gastric cells were treated with 0, 25-, 100-, and 200-mg/L 5-fluorouracil (5-Fu) for 24 h, respectively, then Raman spectra of cells were recorded. The excitation wavelength was 514.5 nm and the Raman spectra in the region of 500 - 1800 cm-1 were recorded. For the gastric cancer cells, as the concentration of 5-Fu increases, the band at 1094 cm-1 attributed to the symmetric stretching vibration mode of PO2- in the DNA backbone gradually decreases, and the intensity ratio of the band at 1315 cm-1 to that at 1340 cm-1 (I1315/I1340) shows the ascending trend, and the ratio of the band area at 1655 cm-1 to that at 1450 cm-1 (A1655/A1450) shows the slight ascending trend. For the normal gastric cells, these peaks also appear changes, however, the changes are weaker than those for the cancer cells. In SGC-7901 cells, 5-Fu can interfere with the DNA synthesis and result in the reduction of the DNA content. Besides, it can affect the unsaturation degree of the hydrocarbon chains and alter the external environment of guanine and adenine residues in cancer cells. The changes of Raman spectra for normal gastric cells reveal the side effect of 5-Fu.     

Ⅱ型糖尿病人与大鼠红细胞拉曼光谱学比较

使用激光共聚焦拉曼光谱仪测量正常大鼠红细胞、正常人红细胞、糖尿病STZ造模大鼠红细胞、糖尿病四氧嘧啶造模大鼠红细胞和人Ⅱ型糖尿病红细胞的拉曼光谱,应用主成分分析(principal component analysis,PCA)结合支持向量机(support vector machines,SVM)分类器对数据进行判别分析,然后采用类间距离判断两种造模方法与人Ⅱ型糖尿病的接近程度。结果发现糖尿病红细胞与正常红细胞的拉曼光谱存在明显差异,糖尿病在酰胺 ⅥCO变形振动谱带处峰高显著,并在酰胺ⅤN—H变形振动谱带处谱线出现偏移,属于磷脂的脂酰基C—C骨架1 130 cm-1谱线增强,1 088 cm-1谱线强度减弱,说明糖尿病红细胞膜的通透性增强。PCA结合SVM可以很好地区分以上5类红细胞的拉曼光谱,分类器测试结果表明分类准确度达100%。通过分别计算两种造模方法与人Ⅱ型糖尿病的类间距离,发现STZ造模法更接近人Ⅱ型糖尿病。由此得出结论：拉曼光谱法可以用于糖尿病诊断,大鼠糖尿病STZ造模法更接近人类Ⅱ型糖尿病。