三维多孔支架材料PLLA/n-HA的体外生物相容性研究

目的：研究三维多孔支架材料聚乳酸/纳米羟基磷灰石(PLLA/n-HA)的体外生物相容性,探讨其作为细胞培养材料和骨组织工程支架的可行性。方法将大鼠成骨细胞接种于PLLA/n-HA复合支架上,体外共同培养后,CCK-8法检测大鼠成骨细胞增殖活性,荧光倒置显微镜、扫描电子显微镜下观察PLLA/n-HA复合支架材料表面和孔隙内细胞粘附情况。结果 CCK-8法检测显示实验组复合支架材料上细胞的增殖与空白对照组的差异无统计学意义（P>0.05）;电镜观察到细胞在复合支架材料表面和孔隙内大量黏附、生长,并且随着共培养时间的增加,材料表面的细胞数量呈几何级增长。结论三维多孔支架材料PLLA/n-HA的生物相容性较好,可望成为一种性能良好的骨组织工程支架材料。     

聚乳酸/羟基磷灰石纳米复合物对MC3T3-E1细胞增殖活性的影响

背景:研究表明聚乳酸/羟基磷灰石复合材料与自然骨结构和性能相似,具有骨传导性和良好的生物相容性。目的:观察聚乳酸/羟基磷灰石纳米复合物与成骨细胞株MC3T3-E1的生物相容性。方法:分别采用普通完全培养基(对照组)与聚乳酸/羟基磷灰石纳米复合物浸提液(实验组)培养第3代成骨细胞株MC3T3-E1,培养3,5,7 d,采用CCK-8法检测细胞的吸光度值;在培养第7,14天检测细胞碱性磷酸酶、骨钙素、Ⅰ型胶原、核心结合因子α1/成骨特异性转录因子表达。将聚乳酸/羟基磷灰石纳米复合物与第3代成骨细胞株MC3T3-E1共培养,培养7,14 d细胞骨架染色及扫描电镜观察细胞在支架材料上的形态。结果与结论:随着时间的延长,成骨细胞株MC3T3-E1的吸光度值明显增加,两组细胞吸光度值比较差异无显著性意义。实验组培养第7天细胞碱性磷酸酶活性高于对照组(P0.05),培养第14天细胞碱性磷酸酶、Ⅰ型胶原、核心结合因子α1/成骨特异性转录因子表达高于对照组(P0.05)。种植7 d后细胞在材料上贴附生长,细胞呈多角形;种植14 d后细胞较7 d前数目明显增多,且完全伸展,呈多角形和梭形。表明聚乳酸/羟基磷灰石纳米复合物对成骨细胞有良好的生物相容性,无细胞毒性。     

胶原多糖基纳米羟基磷灰石仿生骨支架材料的研制

目的依据仿生原理制备新型的胶原多糖基纳米羟基磷灰石（HA）复合骨支架材料,并与成骨细胞复合培养,检测其细胞相容性。方法以胶原分子与透明质酸钠的交联产物为模板,调制钙磷盐在液相中沉积其上,得到矿化胶原多糖基复合材料;采用液相分离法与少量聚乳酸复合进一步制备成为三维多孔支架,使用成骨细胞（Mc3T3-E1）接种于该支架上培养。用X—ray衍射、扫描电镜、万能材料测试机等对材料进行观察和测试分析;并用倒置相差显微镜、荧光显微镜、扫描电镜、CCK-8细胞计数试剂盒、碱性磷酸酶（ALP）活性测定等观察和分析细胞在支架材料中的生长、分化情况。结果胶原多糖基纳米HA仿生复合材料的晶粒度较低,晶体极为细小,与天然骨中羟基磷灰石的组装结构类似;该复合支架为多孔状,孔隙率约82％,孔径大小为200～650μm;抗压性能好,成骨细胞可在其上贴附、生长和繁殖,并表现出较高的成骨活性。结论所制备的胶原多糖基纳米HA仿生骨支架材料,无论从组分和结构上均与天然松质骨类似,与成骨细胞相容性好,可望成为较理想的骨组织工程支架材料。     

仿生支架材料骨形态发生蛋白7多肽/壳聚糖/纳米羟基磷灰石/胶原的制备及其细胞相容性

背景：目前骨组织工程常用的支架材料主要有无机材料、有机高分子材料及天然衍生材料等,上述材料各有优缺点,为了充分发挥各类材料的优势,弥补其不足,目前多采用联合材料制备复合支架。 目的：制备新型仿生支架材料骨形态发生蛋白7多肽/壳聚糖/纳米羟基磷灰石/胶原,并观察其对骨髓间充质干细胞增殖、黏附及分化的影响。 方法：制备壳聚糖/纳米羟基磷灰石/胶原复合支架材料,扫描电镜观察支架材料表面微观形貌;采用真空吸附法将骨形态发生蛋白7多肽与支架材料复合,高效液相色谱仪检测骨形态发生蛋白7多肽在体外的释放规律;将骨髓间充质干细胞接种到复合骨形态发生蛋白7多肽的仿生支架材料上,以未复合多肽的支架材料作为对照,检测支架材料表面细胞增殖、黏附率、生长形态及碱性磷酸酶活性。 结果与结论：壳聚糖/纳米羟基磷灰石/胶原支架材料呈多孔状,孔径10~100 µm;骨形态发生蛋白7多肽可以从支架材料中缓慢释出;在复合多肽的仿生支架材料表面,骨髓间充质干细胞的黏附及向成骨细胞方向分化能力均明显强于对照组(P < 0.05),而增殖能力与对照组差异无显著性意义(P > 0.05)。说明新型仿生支架材料骨形态发生蛋白7多肽/壳聚糖/纳米羟基磷灰石/胶原是一种理想的骨组织工程支架材料,具有良好的细胞相容性。     

骨髓间充质干细胞与不同基质修饰的纳米晶胶原基骨体外生物相容性研究

研究大鼠骨髓间充质干细胞(MSCs)诱导培养后与不同基质修饰的纳米晶胶原基骨(nanoHydroxyapatite/collagen,nHAC)的生物相容性,为骨组织工程提供一种新型复合支架材料。SD大鼠MSCs经成骨诱导培养、扩增,进行成骨细胞表征后,种植与支架材料体外复合培养。实验分为4组:实验组A,纤维蛋白(FB)和纤维连接蛋白(FN)修饰的纳米晶胶原基骨((FB FN)-nHAC);实验组B,纤维蛋白修饰的纳米晶胶原基骨(FB-nHAC);实验组C,纤维连接蛋白修饰的纳米晶胶原基骨(FN-nHAC);对照组D,单纯的纳米晶胶原基骨(nHAC)。通过检测支架材料的细胞黏附率、不同时间点(3、7、10、14d)支架材料中细胞数、碱性磷酸酶活性以及扫描电镜观察细胞在材料上的生长状况,比较分析不同支架材料与细胞生物相容性差异。大鼠MSCs经诱导培养14d后,碱性磷酸酶细胞化学染色、I型胶原免疫荧光染色及矿化沉积茜素红染色均为阳性;细胞与支架材料黏附率A组最高为74.4%;支架材料中细胞数量均随培养时间延长而增长,且A组细胞数增加较快,与相同时相点其他各组材料中细胞数差异有显著性(P<0.05);各时相点细胞碱性磷酸酶活性表达A组最高,差异亦有显著性(P<0.05)。电镜观察发现4组材料上均有细胞生长,但A组的细胞生长状况明显好于其他组。大鼠MSCs经成骨诱导培养,可表达成骨细胞表型,(FB FN)-nHAC在体外实验中表现出与细胞优良的生物相容性,可作为较理想的新型复合支架应用于骨组织工程。     

煅烧骨/壳聚糖复合材料对成骨细胞增殖黏附的影响

文题释义：壳聚糖：是甲壳素的脱乙酰产物,属于天然聚合物,广泛存在于低等生物体内,其代谢产物为N-乙酰葡萄糖和氨基多糖,是天然代谢产物,对人体组织无毒无害,具有良好的生物相容性和生物降解性。 体外细胞毒性实验：是运用体外细胞培养技术检测待测物质和(或)其浸提液是否造成细胞生长受到抑制、变异、溶解、死亡等情况,是生物材料评价体系中非常重要的指标之一,也是各种生物材料运用到临床前安全性评价的必选和首选项目。背景：前期研究制备了不同配比的煅烧骨/壳聚糖复合材料,体外细胞实验显示该复合材料安全无毒。目的：观察煅烧骨/壳聚糖复合材料对成骨细胞增殖与黏附的影响。方法：采用溶液共混法制备煅烧骨与壳聚糖质量比分别为1/2、1/1、2/1的复合材料,将新生大鼠成骨细胞分别接种于3种复合材料上,以单独培养的细胞为对照。采用CCK-8法检测细胞增殖情况,DAPI荧光染色观察细胞在材料上的生长情况,扫描电镜观察细胞在复合材料表面的黏附。 结果与结论：①CCK-8检测显示4组成骨细胞增殖良好,在培养的第1-3天增殖较慢,第3天后增殖加快,第3-7天进入对数生长期,第7天后进入平台期,复合材料组细胞增殖与对照组无差异;②培养3 d后的DAPI荧光染色显示,成骨细胞在3种复合材料表面生长良好,组间无明显差异;③扫描电镜显示,培养3 d后成骨细胞紧密黏附于3种复合材料表面,伸展完全,胞体丰满并伸出伪足嵌入材料内部;培养7 d后细胞铺满材料表面,生长密集,其中质量比为2/1煅烧骨/壳聚糖复合材料表面的细胞最密集;④结果表明,成骨细胞可在煅烧骨/壳聚糖复合材料表面增殖与黏附。ORCID: 0000-0003-3519-4485(廖健) 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     

胶原-纳米羟基磷灰石复合支架的细胞相容性

背景：观察成骨细胞在生物材料上的形态、增殖和分化等项目,可评估生物支架材料的生物相容性。 目的：观察复合支架材料纳米羟基磷灰石/胶原对成骨细胞增殖、分化的影响。 方法：取新生24 h内Wistar大鼠的颅盖骨,采用改良胶原酶消化法进行成骨细胞原代培养,取第3代细胞与纳米羟基磷灰石/胶原支架或普通羟基磷灰石材料体外复合培养。培养3,6,9 d后,观察材料周边的细胞形态及支架材料对细胞分化、增殖的影响。 结果与结论：纳米羟基磷灰石/胶原材料较普通的羟基磷灰石材料更有利于成骨细胞的黏附、生长、分化、增殖,证实其生物相容性更好,有望成为一种新型的骨组织工程支架材料。     

纯钛表面阳极氧化增强成骨细胞生物活性及护骨素基因的表达

背景:纯钛阳极氧化改性后形成的纳米结构与骨组织具有良好的生物相容性。目的:观察纯钛表面纳米孔结构的形貌和物相构成,以及其对MC3T3-E1小鼠前成骨细胞增殖、黏附等生物学行为和促成骨基因护骨素表达的影响。方法:取纯钛片24份,其中12份仅进行机械抛光,作为对照组;另外12份进行机械抛光后,应用阳极氧化技术在纯钛表面制备纳米孔结构,作为实验组。将小鼠前成骨细胞MC3T3-E1分别接种于两组试件表面,接种7 d后扫描电镜下观察细胞形态,采用MTT法检测细胞增殖情况,绘制生长曲线;同时检测细胞促成骨基因护骨素的表达。结果与结论:阳极氧化后钛片表面形成规格统一的纳米孔结构,但是物相构成并未发生变化。与接种于对照组试件上的成骨细胞相比,实验组试件表面的细胞密度变大,覆盖金属的面积更多,呈现多边形结构,突触向周围移行,可见板状伪足向周围材料伸出;接种第7天时,实验组细胞数目约为对照组的1.4倍,同时纳米孔表面成骨细胞护骨素基因的表达高于对照组(P0.01)。结果表明阳极氧化后形成纳米孔结构的钛片更有利于成骨细胞的黏附、增殖和护骨素基因的表达,进而促进成骨细胞生长,具有良好的生物相容性。     

改性3D打印钛支架对脂肪间充质干细胞成骨分化的影响北大核心

背景:3D打印钛支架克服了传统钛支架内部结构可控性差及外形不匹配等缺陷,但由于钛的生物惰性较大,使其在植入体内后难以与周围组织快速稳定地结合。目的:采用喷砂酸蚀和阳极氧化方法改性3D打印钛支架表面,观察其对脂肪间充质干细胞黏附、增殖和成骨分化能力的影响。方法:采用喷砂酸蚀联合阳极氧化方法在3D打印钛支架表面构建微纳米多孔结构,扫描电镜观察其表面特征。将第3代大鼠脂肪间充质干细胞分别接种于3D打印钛支架组(A组)、3D打印钛支架+成骨诱导液(B组)、改性3D打印钛支架(C组)上,通过细胞骨架与CCK-8实验检测细胞的黏附和增殖能力,碱性磷酸酶与茜素红染色观察细胞的成骨分化能力,实时定量PCR分析细胞成骨相关基因的表达,免疫荧光染色观察细胞骨钙素与骨桥蛋白的表达。结果与结论:①扫描电镜下可见,改性后的3D打印钛支架表面出现微米及亚微米级凹坑和沟槽,内部有直径为70-100 nm的纳米级孔隙,孔隙之间相互连通;②共聚焦显微镜下可见,A、B组细胞伪足及触角较少,尚未铺展;C组细胞完全铺展在材料表面,可见大量明显的细胞伪足和触角,紧密附着于材料表面;CCK-8实验显示,改性3D打印钛支架可促进脂肪间充质干细胞的增殖;③碱性磷酸酶与茜素红染色显示,B、C组碱细胞性磷酸酶活性与矿化水平高于A组(P<0.05);④B、C组细胞骨钙素、RUNX2、碱性磷酸酶及Ⅰ型胶原mRNA表达均高于A组(P<0.05),骨桥蛋白与骨钙素蛋白表达均高于A组(P<0.05);⑤结果表明,喷砂酸蚀联合阳极氧化改性3D打印钛支架具有良好的生物相容性,可促进脂肪间充质干细胞的黏附、增殖和成骨分化。     

成骨细胞与镁合金表面硅酸盐-磷酸盐复合涂层的体外相容性

目的 评价成骨细胞在镁合金表面硅酸盐磷酸盐复合涂层上的生长状况,探讨镁合金表面硅酸盐磷酸盐复合涂层与成骨细胞的生物相容性。 方法 用胶原酶消化法分离培养大鼠成骨细胞,并用免疫荧光和茜素红染色法进行鉴定;然后将第4代大鼠的成骨细胞接种于材料表面,用扫描电镜观察成骨细胞在不同表面上黏附形态的变化,同时制备材料浸提液,用浸提液法培养细胞,并通过四甲基偶氮唑盐（MTT）法和碱性磷酸酶（ALP）活性法检测成骨细胞的增殖和分化情况。 结果 将成骨细胞与材料进行复合培养后,扫描电镜下可见,涂层组的成骨细胞生长活力旺盛、形态饱满、分布均匀,而单纯镁合金组未见细胞生长;MTT和ALP活性分析结果显示,硅含量为1%~5%涂层对大鼠成骨细胞的体外生长、增殖和分化的促进作用最佳。 结论 镁合金表面硅酸盐磷酸盐涂层与成骨细胞具有良好的相容性,在体外培养的环境下,有利于细胞的生长、黏附、增殖和分化。     

Schizophrenia in a North Swedish geographical isolate, 1900–1977. Epidemiology, genetics and biochemistry

Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc² (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.     

Renal dysplasia and asplenia in two sibs

A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.     

The dominant diseases of modernized societies as omega-3 essential fatty acid deficiency syndrome: Substrate beriberi

About 1900, modern food selection and processing caused widespread $\text{epidemics}$ of the B vitamin deficiency diseases of beriberi and pellagra which, for genetic reasons, often expressed as different diseases ranging from bowel and heart disease to dermatoses and psychoses. But the B vitamins merely help convert essential fatty acids (EFA) into the prostaglandin (PG) tissue regulators and it now turns out that, through hydrogenation, milling and selection of w3-poor southern foods, we have also been systematically depleting, by as much as 90%, a newly discovered trace Nordic EFA (w3) of special importance to primates and sole precursor of the PG3(4) series, even as a concurrent fiber deficiency increases body demand for EFA. Since substrate EFA is processed by many B vitamin catalysts, an EFA deficiency will mimic a $\text{panh}$ypovitaminosis B, i.e., a mixture of $\text{substrate}$ beriberi and $\text{substrate}$ pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse $\text{endemic}$ disease. This would consitute a second stage of the Modern Malnutrition and explain why some workers now hold the dominant diseases of modermized societies to be new, nutritionally based, pellagraform yet lipid-related and to range, once again, from heart disease to psychosis. It is an assumption that our dominant diseases are unrelated to each other or are merely revealed by our diagnostic acumen and therapeutic success; and that hydrogenating millions of tons of food oils annually, to destroy the rancidity producing w3-EFA, is safe for $\text{primates}$. Extensive beriberiform disease is reported here in 32 typical cases taken from medical practice which responds strikingly to linseed oil supplements (60% w3-EFA) in confirmation of identical results in Capuchins.     

'Very sore nights and days': the child's experience of illness in early modern England, c.1580-1720

Sick children were ubiquitous in early modern England, and yet they have received very little attention from historians. Taking the elusive perspective of the child, this article explores the physical, emotional, and spiritual experience of illness in England between approximately 1580 and 1720. What was it like being ill and suffering pain? How did the young respond emotionally to the anticipation of death? It is argued that children’s experiences were characterised by profound ambivalence: illness could be terrifying and distressing, but also a source of emotional and spiritual fulfilment and joy. This interpretation challenges the common assumption amongst medical historians that the experiences of early modern patients were utterly miserable. It also sheds light on children’s emotional feelings for their parents, a subject often overlooked in the historiography of childhood. The primary sources used in this article include diaries, autobiographies, letters, the biographies of pious children, printed possession cases, doctors’ casebooks, and theological treatises concerning the afterlife.     

Guidelines for the Validation and Use of Immunoassays for Determination of Introduced Proteins in Biotechnology Enhanced Crops and Derived Food Ingredients

Recent advancements in agricultural biotechnology have created a need for analytical techniques to determine introduced proteins in crops enhanced through modern biotechnology techniques. These proteins are expressed in plant tissues and may be present in food ingredients. Immunoassays are ideally suited for protein detection and may be used as both quantitative and threshold methods. Microplate ELISA and lateral flow devices are two of the most commonly used immunoassay formats for agricultural biotechnology applications. This paper provides general background information and a discussion of criteria for the validation and application of immunochemical methods to the analysis of proteins introduced into plants and food ingredients using biotechnology methods. It is the result of a collaborative effort of members of the Analytical Environmental Immunochemical Consortium. This collaborative effort represents the combined expertise of several organizations to reach consensus on establishing guidelines for the validation and use of immunoassays. Further, the paper offers developers and users a consistent approach to adopting the technology as well as aid in producing accurate and meaningful results.     

Ultracryotomy: development and application (with examples from the yeast cytology) (author's transl)

The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning, and post-staining the sections for transmission electron microscopy) are submitted to a critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. Fundamental considerations of chemical prefixation and poststaining are supported by examples from yeast cytology. Furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.     

HLA in North Colombia Chimila Amerindians

HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.     

The case for allele‐specific recognition by the TCR

There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable.     

The universal muscular chamber. A basic unit of the genitourinary, cardiovascular, gastro-intestinal, skeletal, cutaneous, respiratory and other systems, endocameral hypertension; and spasm, the key to their idiopathic diseases and arthropathies

Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.