表没食子儿茶素没食子酸酯对心血管疾病防治作用的研究进展

中国在公元前3 000年以前就有饮用绿茶的记载。现代技术发现绿茶含有大量的茶多酚,儿茶素是茶多酚的主要成分,包括4种单体物质,即表没食子儿茶素没食子酸酯[(-)-epigallocatechin gallate, EGCG]、表儿茶素没食子酸酯(epicatechin gallate,ECG)、表没食子儿茶素(epigallocatechin,EGC)和表儿茶素(epicatechin,EC),其中最主要的活性成分EGCG被认为具有抗癌、减肥、抗糖尿病、抗菌、抗病毒、预防龋齿等作用^[1]。大量研究发现饮茶也会减少心血管疾病的发生风险,对心脏具有明确的保护作用,本文就EGCG对心血管疾病的预防作用研究进展进行综述。     

负载表没食子儿茶素没食子酸酯硅酸钙微球的制备及抗菌性能评价

背景：茶多酚的主要活性成分为表没食子儿茶素没食子酸酯,其具有抗氧化、抗菌、抗凋亡、抗炎等多种生物学功能。为实现表没食子儿茶素没食子酸酯的可控释放、提高其生物利用度,开发具有生物活性的茶多酚载体是亟待解决的难题。目的：制备高效负载表没食子儿茶素没食子酸酯的微球,同时加测其抗菌性能及生物相容性。方法：采用化学沉淀法分别制备硅酸钙微球与二氧化硅微球,利用X射线光电子能谱、透射电镜、场发射扫描电子显微镜、比表面积分析仪、激光粒度分析仪对微球的性能进行表征。将两种微球分别浸泡于表没食子儿茶素没食子酸酯溶液中,制备负载表没食子儿茶素没食子酸酯的硅酸钙微球与二氧化硅微球(分别记为CSM-EGCG、SM-EGCG),检测微球的载药量及包封率,以及体外表没食子儿茶素没食子酸酯的释放情况。将未载药的硅酸钙微球、二氧化硅微球及CSM-EGCG、SM-EGCG分别与金黄色葡萄球菌、大肠杆菌共培养,检测抑菌率。将上述4种微球分别与人皮肤成纤维细胞共培养,通过CCK-8法评估细胞活性。结果与结论：(1)表征实验结果显示,硅酸钙微球和二氧化硅微球均为介孔微球,分散性好,硅酸钙微球的比表面积、总孔体积、平均孔径均大于...     

表没食子儿茶素没食子酸酯对人乳腺癌MCF-7细胞及其血管内皮细胞生长因子-C表达的影响

目的:探讨体外应用表没食子儿茶素没食子酸酯(EGCG)对人乳腺癌MCF-7细胞增殖、侵袭及其对血管内皮细胞生长因子-C (VEGF-C)表达的影响.方法:体外培养MCF-7细胞,设立对照组及EGCG实验组,应用MTT法及Transwell侵袭实验观察不同浓度EGCG对MCF-7细胞增殖及侵袭的影响;应用免疫细胞化学显色...     

表没食子儿茶素没食子酸酯对小鼠耐缺氧及抗疲劳作用的实验研究

目的:观察表没食子儿茶素没食子酸酯(Epigallocatechin-3-gallate,EGCG)对小鼠的缺氧耐受及抗疲劳作用并初步探讨其机制与抗氧化作用的关系.方法:将小鼠随机分成对照组、低浓度组(EGCG1)和高剂量组(EGCG2),低剂量EGCG每天灌胃10 g?kg-1,高剂量EGCG每天灌胃50 g?kg-...     

两种脱敏剂封闭牙本质小管的扫描电镜观察

背景：MS Coat、极固宁脱敏剂均可以有效封闭牙本质小管,隔绝外界刺激,降低牙本质敏感。国内外学者对两者效果的对比多为描述性、定性研究。 目的：通过扫描电镜定量观察MS Coat、极固宁脱敏剂对牙本质小管的封闭效果,并做出比较。 方法：将30颗人离体新鲜第三磨牙样本制成3 mm厚的牙本质盘,以17%EDTA液体处理牙本质表面2 min,随机均分为3组,空白对照组不做任何处理,MS Coat组和极固宁组分别用MS Coat脱敏剂和极固宁脱敏剂对牙本质表面进行处理,采用扫描电镜观察各组牙本质表面和纵剖面结构。 结果与结论：①表面观察：空白对照组牙本质小管全部开放;MS Coat组绝大部分牙本质小管口被堵塞;极固宁组牙本质小管口覆盖不规则鳞状晶体物质,仍可见一小部分暴露的牙本质小管口,但直径变窄。②纵剖面观察：空白对照组牙本质小管呈条状平行排列,无任何堵塞物;MS Coat组小管口有沉淀物沉积,较致密,基本上封闭了牙本质小管口;极固宁组牙本质小管内有鳞片状晶体物质沉积。组间牙本质直径及小管数量比较：空白对照组>极固宁组> MS Coat组(P < 0.05)。表明MS Coat脱敏剂和极固宁脱敏剂均能有效封闭牙本质小管,且MS Coat脱敏剂的封闭效果优于极固宁。 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

牙本质保护膜对牙本质小管的封闭作用**

背景：有临床研究报道牙本质保护膜在用于烤瓷全冠牙体预备后牙本质面的保护处理后,能有效降低基牙敏感度。 目的：体外实验观察牙本质保护膜封闭牙本质小管的效果。 方法：将20颗完好离体人前磨牙分为3组：空白对照组牙本质表面不作任何处理,对照组牙本质表面涂布格鲁玛脱敏剂,实验组牙本质表面涂布牙本质保护膜,在扫描电镜下观察牙本质小管口封闭情况。 结果与结论：扫描式电子显微镜观察显示,实验组牙本质小管口密度和直径均明显低于对照组与空白对照组(P < 0.05),牙本质小管口相对面积明显低于空白对照组(P < 0.01)。表明牙本质保护膜在减小牙本质小管的密度和直径方面的作用优于格鲁玛脱敏剂。     

表没食子儿茶素没食子酸酯预防正畸固定矫治者的牙釉质白斑

文题释义： 龋白斑：很多接受正畸固定矫治的患者其牙面上会呈现白垩色的点或斑块，临床上表现为龋白斑(white spot lesions，WSL)，即釉质脱矿，如病变进一步发展甚至会形成龋洞。 表没食子儿茶素没食子酸酯(Epigallocatechin gallate，EGCG)：是茶多酚中最有效的活性成分，属于儿茶素。EGCG具有抗菌、抗病毒、抗氧化、抗动脉硬化、抗血栓形成、抗血管增生、抗炎以及抗肿瘤作用。绿茶里有EGCG，但红茶里没有，因为红茶里的EGCG被转化成了茶玉红精。EGCG在医药保健上具有防治癌症等多种疾病和增强免疫力等功能。 背景：目前已有大量研究证实表没食子儿茶素没食子酸酯(Epigallocatechin gallate，EGCG)可应用于牙科治疗中，但目前尚未有临床研究讨论EGCG用于托槽的釉质粘接是否可以减少临床上正畸术后白斑的发生率。目的：探讨EGCG应用于预防正畸固定矫治患者牙釉质白斑发生的价值。方法：选择接受正畸固定矫治治疗的50例符合纳入排除标准的患者，采用自身对照法，右侧使用添加有1 g/L EGCG的粘接剂(EGCG组)，左侧使用不含EGCG的粘接剂(对照组)，其余治疗步骤和材料均相同。于治疗开始后3，6和12个月检测目标牙位(16，11，46，26，31，36)牙釉质脱矿指数(EDI)和釉质白斑的发生率，并统计托槽脱落情况。研究方案的实施符合柳州市人民医院对研究的相关伦理要求，患者及监护人对试验过程完全知情同意。结果与结论：①EGCG组和对照组在试验期间托槽脱落率差异无显著性意义(P > 0.05)；②在治疗开始后3个月，2组白斑发生率和牙釉质脱矿指数值差异无显著性意义(P > 0.05)，治疗6，12个月，EGCG组白斑发生率和牙釉质脱矿指数值均较对照组显著降低(P < 0.05)；③结果说明，添加有1 g/L EGCG的粘接剂可以在不影响托槽粘接强度的情况下，起到预防正畸固定矫治患者牙釉质脱矿和白斑发生作用，且能长期维持。 ORCID: 0000-0002-5325-5037(杨柳青) 中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程     

草酸铁溶液处理牙本质后黏结界面的超微形态

背景：基于流体动力学说,选择良好的生物材料封闭暴露的牙本质小管口是国际上对治疗牙齿敏感研究的热点。草酸铁溶液可以在牙本质小管内形成结晶样结构。 目的：观察草酸铁溶液结合全酸蚀黏结系统处理牙本质后黏结界面的形态学变化。 方法：选择无龋人离体智齿12颗,去除牙冠牙釉质,暴露牙本质。随机均分为实验组和对照组, 32%磷酸酸蚀剂酸蚀牙本质黏结面,实验组用5.3%草酸铁溶液处理表面1 min后充分冲洗10 s,两组表面再充填树脂。平行牙长轴方向片切制备扫描电镜试样,在扫描电镜(SEM)下观察黏结界面的微观形态。 结果与结论：实验组草酸铁产生的结晶样结构几乎堵塞全部牙本质小管开口,树脂层伸出无数短小树脂突嵌于硬化的牙本质小孔内。对照组局部区域混合层与其下方未脱矿的牙本质间有明显的裂隙出现,树脂突较粗,但长短不均匀,可见树脂突的断裂。提示,5.3%草酸铁溶液能够在牙本质小管内形成结晶,使牙本质小管口封闭良好。对照组可见树脂突的断裂,牙本质小管暴露,封闭不严密。说明5.3%草酸铁溶液结合全酸蚀黏结系统治疗牙本质龋能够提高其临床治愈率。     

硅酸三钙封闭牙本质小管的作用

背景：多项体外实验证实硅酸三钙不仅可以通过自固化过程与牙本质紧密结合,而且在生理环境下能诱导牙本质再矿化,有效阻塞牙本质小管。 目的：进一步验证硅酸三钙对牙本质小管的封闭作用。 方法：选择正畸患者拔除的第一前磨牙制作离体牙本质盘36块,分别经 0.29 mol/L EDTA 内浸置 2 min,6%柠檬酸蚀 1 min 后冲洗,蒸馏水超声清洗 20 min 3种方法预处理,模拟具有牙本质小管不同开放程度的牙本质敏感症。以上每组随机分为3个亚组,即硅酸三钙组、氟化钠对照组、空白对照组,前2组每天早晚分别用对应材料涂刷表面,2 min/次,空白对照组不处理,其余时间全部置于人工唾液 37 ℃恒温箱中保存。14 d后通过扫描电镜观察各组处理前后牙本质形态,并计算开放牙本质小管直径和面积。 结果与结论：经不同预处理后牙本质小管都呈开放状态,但柠檬酸和EDTA预处理溶液较蒸馏水有更强的脱矿作用,牙本质小管更加清晰。各组经氟化钠或硅酸三钙涂擦后,牙本质小管口有不同程度沉积物,且开放牙本质小管面积及平均直径较空白对照组小(P < 0.05);经硅酸三钙涂擦的牙本质小管几乎完全均质封闭,偶见有单个孤立开放的牙本质小管口,开放牙本质小管面积及平均直径都明显低于氟化钠对照组(P < 0.05)。证实硅酸三钙可有效封闭牙本质小管,且效果优于氟化钠;在治疗牙本质过敏时,如果先用EDTA或酸蚀剂处理,脱敏效果会更完善。     

生物活性玻璃对早期人工釉质龋的再矿化

背景：生物活性玻璃具有良好的生物相容性,且具有抑制口腔致龋细菌和牙周相关细菌及抗牙本质过敏的作用。 目的：评价生物活性玻璃促进早期人工釉质龋再矿化的作用。 方法：将新鲜拔除的30颗牛切牙制成人工龋模型,将标本在37 ℃人工脱矿液内脱矿72 h,用扫描电镜观察脱矿后釉质表面的平滑情况,用显微硬度仪测量脱矿后釉质的显微硬度。然后随机分为3组,每组10个。采用pH循环法模拟人口腔环境,将3组标本分别浸泡在生物活性玻璃溶液、氟化钠溶液及人工唾液内,3次/d,10 min/次,循环浸泡20 d,扫描电镜检测标本脱矿及再矿化情况,用显微硬度计检查牙釉质显微硬度。 结果与结论：浸泡在生物活性玻璃溶液中的牙釉质表面较浸泡在其他两溶液中的牙釉质表面光滑平整,无空隙存在;浸泡在生物活性玻璃溶液中的牙釉质表面显微硬度高于浸泡在其他两溶液中的牙釉质表面显微硬度(P < 0.05)。说明生物活性玻璃在体外实验中能促进早期釉质龋的再矿化。     

Characterization of sterols of three digenetic trematodes of buffalo

Sterols of three digenetic trematodes were isolated and characterized by infrared and 1H nuclear magnetic resonance spectroscopies, and gas-liquid chromatography and gas chromatography-mass spectrometry. Sterols identified were cholesterol, cholestanol, 24-methylcholesterol, 24-methylcholestanol, 24-ethyl-22-dehydrocholesterol, 24-ethyl-22-dehydrocholestanol, 24-ethylcholesterol and 24-ethylcholestanol.     

Level of functioning of siblings and parents of probands of varying degrees of retardation

A further analysis of already published data supports the position that retardates of low ability level less frequently have retarded siblings, retarded parents, and parents low in occupational level than do retardates higher in ability level. The analysis supports the position that there are two types of retarded individuals, persons retarded as a result of gene or chromosomal anomalies, brain injury, etc., who more frequently occur in the lower-level retardate group, and persons whose retardation represents polygenic segregation, who more frequently occur in the higher-level group.     

局部注射辛伐他汀对骨质疏松大鼠股骨髁骨小梁的改建效应

背景：局部注射具有成骨作用的辛伐他汀,可显著增加骨质疏松大鼠股骨颈及股骨髁部的骨密度及力学强度,分析局部注射辛伐他汀对股骨髁骨小梁的影响。 目的：进一步研究骨质疏松大鼠股骨内局部注射辛伐他汀对股骨髁骨小梁的影响。为将辛伐他汀应用于临床骨质疏松局部治疗提供实验基础。 方法：18只雌性SD大鼠双侧卵巢切除后3个月,制备大鼠骨质疏松模型。实验大鼠随机数字表法均分为3组,分别在实验大鼠的右侧股骨髓腔内单次注射辛伐他汀溶液5 mg、10 mg,对照组单纯注射空白载体。分别在注射后1个月处死大鼠并取材。Micro-CT扫描并定量分析骨组织形态变化。 结果与结论：给药后1个月,Micro-CT扫描结果显示,辛伐他汀治疗组的骨微结构参数如骨皮质厚度、骨小梁密度及连接率明显优于对照组。说明疏松骨骼单次注射小剂量辛伐他汀可显著促进股骨髁部骨小梁改建,改善骨骼微结构,可为强化局部、防治骨质疏松骨折的新选择进一步提供实验基础。     

石斛属民族药用植物的分类及生药学研究

中药石斛早在《神农本草经》中就被列为上品,其应用历史悠久,具有养阴生津、补肾益气、润喉护嗓、活血明目、抗癌防老等功效。本文对国内外石斛属民族药用植物的分类及生药学研究进行了综述。     

Anatomical study of distribution of valves of the cutaneous veins of adult''s limbs

Since the cutaneous veins of the four limbs have been used as autogenous grafts in the treatment of cardiovascular disorders, knowledge of distribution of the valves is increasingly required depending upon the use. In the gross anatomical study of distribution of valves of the trunci venae, there has been argument about locational relationships between the venous roots and the valves in the vicinity of the roots and the inter-valvular distance. However, there have been only few reports discussing detailed information about valves of the cutaneous veins of the four limbs. The authors observed patterns of distribution of the cutaneous venous valves of the four limbs of cadavers prepared for practice in anatomy. The following parts were excised from each cadaver: the cephalic, basilic, and the great saphenous veins, which originate from the acral venous network and flow into the proximal deep veins, and the venous roots communicating with these veins. An incision was made on each excised vein in the direction of the long axis under observation with a stereoscopic microscope, and the inter-valvular distance and the distance between the valve and the orifice of venous root in the vicinity of the valve were measured. The inter-valvular distance varied with type of the truncus venae, and it varied according to area even in the same truncus venae.     

Comparison of accuracy of diagnostic modalities for evaluation of breast cancer with review of literature

This study was conducted to confirm which of these modalities [mammography (MG), fine‐needle aspiration cytology (FNAC), core‐needle biopsy (CNB), or intraoperative touch imprint cytology (IOTIC)] is useful to detect breast cancer and to compare the accuracy of these modalities for the diagnostic setting. One hundred seventy‐five, 85, 78, and 25 patients were selected who underwent FNAC, MG, IOTIC, and CNB, respectively. Histopathology was used as a gold standard for comparison of the results of all diagnostic modalities. Twenty‐five patients with combinations of three preoperative tests (MG, FNAC, CNB) showed 100% accurate results when compared with histopathology, while the overall accuracy for MG, FNAC, and CNB was 91.7%, 91.5%, and 96%, respectively. Both touch and scrape imprints' sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy were 100% for class V and class II smears, while sensitivity, accuracy, and NPV were 87, 95, and 83% for IOTIC and 94%, 96%, and 89% for IOSC for class III and IV smears. On comparison of the results of all these procedures, the difference was nonspecific (P = 0.2, 0.3, 0.5, 0.55, and 0.6 for MG, FNAC, IOTI, IOSC, and CNB, respectively). Combinations of preoperative tests (MG, FNAC, CNB) were more accurate, reliable, and acceptable when compared with individual diagnostic procedure, but these have their own technical limitations. The accuracy of CNB was much higher than that of MG and FNAC. IOTP and IOSC are simple and cost effective diagnostic tests with better accuracy that can be used as an alternate to frozen section in diagnostic settings and margin assessments. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.     

Effect of prolonged use of high dose of tibolone on the vagina of ovariectomized rats

The aim of this study was evaluate the effect of prolonged use of high dose of tibolone on the vagina of ovariectomized rats. Bilateral ovariectomy was performed on 14 rats weighing 250 g. Thirty days later, vaginal smears were collected verifying the menopause status by anoestrus cytology. Rats were divided randomly into groups: experimental rats (n = 9) received 1 mg tibolone/day orally and control rats (n = 6) received placebo (carboxymethylcellulose). After 150 days, all rats were sedated and euthanized by cervical displacement. The vagina was removed, fixed in 10% buffered formalin, sampled and processed for paraffin embedding. Histological sections were stained with haematoxylin and eosin, picrosirius red, periodic acid Schiff (PAS) and PAS-diastase, and Weigert's resorcin-fuchsin. Cell proliferation was analysed by immunohistochemistry to detect Ki67. Histomorphometric analyses were performed for epithelial thickness, per cent area of collagen fibres and blood vessels, mast cells and Ki67-positive nuclei per mm of basal membrane. Means and standard error of means were calculated, and data were compared using the Mann-Whitney test, with significance level at P < 0.05. In the vagina, epithelial thickness, number of Ki67-positive nuclei per mm of basal membrane, number of vessels and number of mast cells were significantly higher in the tibolone group when compared with the control group. Furthermore, the content of glycogen and glycoproteins in the vaginal epithelium was modified by tibolone. Tibolone administered in high dose and for a long period has a trophic effect, reversing vaginal atrophy, and has no dysplastic or neoplastic effect in the vagina of ovariectomized rats.     

胃小弯侧血管弓的MDCT解剖

目的：研究正常胃小弯侧血管弓及其属支血管的多排螺旋CT表现。方法：回顾性分析51例正常成人的上腹部CT资料,观察胃小弯侧血管弓及其属支血管的显示情况、血管弓形态及其与胃壁的关系。结果：51例均显示胃小弯侧血管弓,血管弓贲门部属支、胃体部属支和幽门部属支分别显示46例、15例和10例;血管弓与胃壁紧邻41例。结论：MDCT检查可良好显示正常胃小弯侧血管弓及其属支血管。     

Effects of pathogenic action of botulinus toxin of spinal motoneurons of various types

Motoneurons of the lumbosacral region of the spinal cord were studied during local botulinus paralysis. The development of paralysis of the poisoned limb was accompanied by lowering of the membrane potential, the amplitude of the antidromic action potentials and of mono- and polysynaptic EPSPs, and the input resistance, and by an increase in the critical depolarization level of the soma membrane of phasic motoneurons in the affected segments of the spinal cord. The excitability of the tonic motoneurons was substantially unchanged in the course of development of local botulism.A. A. Bogomolets Department of Pathological Physiology, Saratov Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR P. N. Veselkin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 80, No. 11, pp. 21–24, November, 1975.     

骨关节炎动物模型的选择

背景:目前骨关节炎的发病原因尚不清楚,而且也没有有效的治疗手段。选择合适的动物模型会给骨关节炎的动物实验创造一个良好的条件。目的:对骨关节炎的不同实验动物及不同造模方式作一综述。方法:检索中国期刊全文数据库(CNKI)、万方数据库、维普数据库和PubMed数据库2013年1月至2018年7月的相关文章,以“骨关节炎、模型动物、大鼠、小鼠、豚鼠、兔、狗、羊”,英文检索词为“Osteoarthritis、Models、Animals、Mice、Rats、Rabbits、Dogs、Goats、guinea pigs、sheep”进行检索,剔除重复文献,选取与骨关节炎动物模型相关的文章,进行整理和分析。结果与结论:小鼠、大鼠、豚鼠、兔、狗、羊等动物都可作为骨关节炎研究的动物模型。而在研究骨关节炎动物实验的时候,正确选择动物模型和造模方式是很重要的。非手术模型避免了手术对于关节其他部位的损伤,更符合骨关节炎的病理过程,但是对于造模方法难以掌控,容易造成误差,且不能模拟创伤改变。手术模型通过手术破坏组织而造成关节损伤,进展快,效果明显,是短期研究的最佳选择。不同的实验动物和造模方案各有其优缺点,需要根据实验的需求合理选择。