MC3T3-E1细胞与多组分纳米羟基磷灰石基三维复合支架材料的相容性

目的 观察MC3T3-E1细胞在复合支架材料上的黏附、增殖及形态,评价多组分纳米羟基磷灰石基三维复合支架材料的生物相容性.方法 采用仿生学方法,将壳聚糖、羟基磷灰石、明胶、果胶按照一定比例制作成多组分纳米羟基磷灰石基三维复合支架材料.在复合支架材料上接种MC3T3-E1细胞,通过倒置相差显微镜、HE染色、扫描电镜、四甲...     

丝素蛋白/壳聚糖复合支架材料的细胞相容性**

背景：大量研究表明丝素蛋白、壳聚糖为天然高分子材料,具有良好的细胞生物相容性。 目的：探讨丝素蛋白/壳聚糖复合支架材料与诱导的兔骨髓间充质干细胞的生物相容性。 方法：将兔骨髓间充质干细胞分离培养、诱导后,与丝素蛋白/壳聚糖三维支架材料体外共培养,以材料的细胞毒性、细胞增殖活力、材料细胞黏附率及扫描电镜等检测评价材料的细胞相容性。 结果与结论：经诱导后的骨髓间充质干细胞在支架材料上黏附、生长良好,保持正常的分裂增殖速度;随时间的增加,细胞黏附率增加,材料组较对照组黏附率强,差异有显著性意义(P < 0.05)。扫描电镜观察发现细胞接种48 h后细胞生长良好,与支架黏附紧密,增殖分裂活跃。说明丝素蛋白/壳聚糖三维支架材料具有良好的细胞相容性。     

脱细胞异体真皮基质与人脂肪干细胞的生物相容性

背景：脱细胞异体真皮基质具有优良的生物相容性和组织细胞诱导功能。 目的：评价人脂肪干细胞与脱细胞异体真皮基质的生物相容性。 方法：取健康成年人吸脂术后的脂肪组织分离脂肪干细胞,并行原代与传代培养,传至第3代,将细胞与脱细胞异体真皮基质联合体外培养3,7 d,倒置相差显微镜和扫描电镜观察细胞在支架材料上的黏附、生长及增殖情况,并计算细胞在材料上的黏附率;XTT比色法检测细胞的生长增殖情况。 结果与结论：脂肪干细胞在支架材料上分布均匀,24 h内细胞开始伸展、黏附,二三天完全伸展变形,以梭形为主,呈网状排列;随着培养时间延长,支架上的细胞逐渐增多;人脂肪干细胞细胞与脱细胞异体真皮基质混合培养后平均黏附率为95.03%,并保持正常的生长增殖速度,表明支架对细胞具有良好的黏附性;脱细胞异体真皮基质材料与人脂肪干细胞复合后相容性良好。     

同种异体松质骨支架材料的制备及理化特性

背景：同种异体脱脂、脱蛋白松质骨具有与受体相同的三维立体结构,力学性能稳定,排异反应弱,细胞相容性好等独特的生物学性能。 目的：通过理化方法制备同种异体脱脂、脱蛋白松质骨支架材料,分析其理化特性。 方法：剥离兔髂骨10对,制作成约1.0 cm×0.8 cm×0.1 cm的骨条,经脱脂、脱蛋白、深低温冷冻处理制备骨支架材料,检测其生物化学性能。测定支架材料与骨髓间充质干细胞的黏附率;将支架植入同种属动物体内,观察其组织相容性、免疫反应。 结果与结论：同种异体脱脂、脱蛋白松质骨支架材料保留了天然骨组织的网状孔隙结构,孔隙率为(80.23±5.65)%,孔径最大为(318.11±17.51) μm,最小为(209.37±11.33) μm。骨髓间充质干细胞不仅能与支架黏附,而且能在支架上分裂、增殖。兔体内植入6周后支架周围界面未引起明显的炎症和排斥反应,并形成少量骨样组织。说明脱脂、脱蛋白松质骨支架具有适宜的三维多孔结构,与种子细胞黏附率高,有良好的生物相容性和细胞-材料界面作用;同时有一定的成骨作用。     

新型胶原支架材料改性的研究

针对脱细胞真皮基质作为复合移植用真皮支架所存在的渗透性较差、降解速率慢、生物活性低等缺点,采用新工艺技术制备了天然三维网络结构的新型胶原支架材料,探讨交联、复合及其顺序和打孔对其理化性能的影响,并通过成纤维细胞培养试验研究其生物相容性.理化性能检测结果显示:复合提高交联试样的孔隙率和延长降解时间;交联明显提高试样的孔隙率和拉伸强度并延长其降解时间;先复合后交联可以提高孔隙率和降解时间;打孔可以明显提高材料的透水汽性和孔隙率.成纤维细胞培养试验表明:成纤维细胞能在改性支架材料上黏附、增殖.新型胶原支架经复合、交联、打孔改性后,其透水汽性明显提高,达到(3372±83)g/(m2·d);孔隙率显著提高,达(94.20±2.5)%;拉伸强度较好,为(10.65±0.32)MPa;体外降解时间为(38.3±1.0)h,通过适当改变交联剂的用量在比较宽的范围,可以满足不同支架材料降解速率的要求;细胞相容性良好.新型胶原支架经复合、交联、打孔改性后有望作为复合移植用的真皮支架.     

异种生物衍生骨支架材料的制备及性能

背景：异种骨来源丰富,价格低廉,处理相对简单容易,处理后骨支架保留原有骨的微结构,具有良好的促成骨、骨传导及骨诱导活性。 目的：检测自制生物衍生骨支架材料的理化性质及体外细胞相容性。 方法：通过脱蛋白、脱脂、脱钙,深低温冻存制备猪源性松质骨支架材料。组织学检测松质骨处理前后的变化,扫描电镜观察材料结构及计算孔隙直径,采用液体置换法检测支架材料的孔隙率,体外降解速度,能谱分析及体外复合兔骨髓间充质干细胞的细胞相容性。 结果与结论：处理后的松质骨支架材料具有三维多孔结构,孔隙直径150.8-306.7 μm,孔隙率84.5%-89.7%。材料在前6周降解速度稍慢,6周后材料降解率曲线基本呈线性且降解速度明显加快,10周时材料接近完全降解,降解率达92.8%。松质骨支架材料孔隙大小适合骨髓间充质干细胞的黏附和增殖。表明生物衍生骨支架材料性能良好,细胞相容性良好,适用于构建组织工程骨。     

透明质酸改性壳聚糖-胶原-羟基磷灰石复合支架力学特性及成骨细胞的增殖

背景：组织工程中,种子细胞需依赖于细胞外基质的存在才能发挥功能。因此支架材料的选择具有重大意义。 目的：制备一种新型改性壳聚糖-胶原-羟基磷灰石复合支架,优化易于细胞黏附的组织工程支架材料工艺。 方法：壳聚糖与透明质酸进行交联,红外和差示扫描量热图谱检测其结构;改性壳聚糖与胶原按1∶2,1∶1和2∶1制备3种改性壳聚糖-胶原-羟基磷灰石复合支架,将复合支架与成骨细胞MC3T3-E1联合培养,CCK-8法检测增殖,绘制生长曲线。 结果与结论：透明质酸和壳聚糖以酰胺键形成交联的新化合物,孔径在50~250 μm之间,孔隙率随着胶原水平、弹性模量的增加而增加,而密度则减少;增加胶原的含量在细胞联合培养初期有利于细胞对支架的黏附和增殖,但从第10天开始,3种样品中细胞数量相差不大,均出现平台期;苏木精-伊红染色发现成骨细胞在培养初期沿着支架材料内部空隙贴壁生长,随着培养天数的增加,贴壁细胞呈集落样生长,可明显看到细胞间连接。说明透明质酸改性壳聚糖/胶原/纳米羟基磷灰石复合材料可以作为骨支架材料供成骨细胞黏附、增殖,其中胶原与壳聚糖的体积比为1∶1为较优配比。     

复合壳聚糖微球-丝素基载药α-磷酸三钙骨水泥的细胞相容性及毒性

背景:磷酸钙骨水泥具有良好的生物相容性和骨传导性,已被应用于临床,但其不良的力学性能和缺乏骨诱导性限制了其进一步发展和应用。目的:制备壳聚糖微球-丝素基载药α-磷酸三钙骨水泥,验证其细胞相容性及细胞毒性。方法:分别以含体积分数10%胎牛血清和1%双抗的α-MEM培养基、苯酚、100%及50%复合壳聚糖微球-丝素基载药α-磷酸三钙骨水泥材料的浸提液培养MC3T3-E1细胞,采用MTT法评估细胞生长增殖情况,采用乳酸脱氢酶活性检测法判断复合壳聚糖微球-丝素基载药α-磷酸三钙骨水泥材料的毒性。将MC3T3-E1细胞系与复合壳聚糖微球-丝素基载药α-磷酸三钙骨水泥材料共培养,扫描电镜观察细胞在材料表面的附着及生长。结果与结论:复合壳聚糖微球-丝素基载药α-磷酸三钙骨水泥材料浸提液对MC3T3-E1细胞的生长增殖无明显影响,无明显细胞毒性。MC3T3-E1细胞在复合壳聚糖微球-丝素基载药α-磷酸三钙骨水泥材料表面生长良好,伸展充分,在材料表面伸出伪足,与材料贴附紧密,表明壳聚糖微球-丝素基载药α-磷酸三钙骨水泥细胞相容性良好。     

补骨脂素抗菌双相陶瓷骨的制备及性能检测

背景：近年来中药在骨组织工程中应用的研究在国内处于起步阶段,尚未见到补骨脂素在骨组织工程支架材料中应用的研究报道。 目的：通过真空复合方法制备出补骨脂素抗菌双相陶瓷骨,检测材料的理化性能、抗菌性和细胞相容性。 方法：将猪椎骨经复合焦磷酸钠两次低温煅烧制备双相陶瓷骨,将双相陶瓷骨置于壳聚糖/补骨脂素复合溶液中,制备补骨脂素抗菌双相陶瓷骨。扫描电镜观察补骨脂素抗菌双相陶瓷骨的表面形貌,并检测其抗压强度;采用微生物法检测补骨脂素抗菌双相陶瓷骨对大肠杆菌、金黄色葡萄球菌的抑制效果;将补骨脂素抗菌双相陶瓷骨与小鼠成骨细胞MC3T3-El共培养4,8 d,扫描电镜观察细胞在材料表面的附着与增殖。 结果与结论：补骨脂素抗菌双相陶瓷骨具有天然的孔隙结构,骨小梁、小梁间隙和骨内管腔系统同时存在,抗压强度为(4.69±0.50) MPa,其对大肠杆菌、金黄色葡萄球菌均有较强的抑制作用,抑菌效果明显;小鼠成骨细胞MC3T3-El可在补骨脂素抗菌双相陶瓷骨上很好的附着,保持良好的状态和功能并快速增殖,说明补骨脂素抗菌双相陶瓷骨具有良好的细胞相容性。 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     

丝素蛋白/壳聚糖三维支架与骨髓间充质干细胞的体外培养

背景：前期实验发现丝素蛋白、壳聚糖以适当的比例混合,可以互相弥补各自的不足,表现出良好的理化性质和生物学特性。 目的：观察骨髓间充质干细胞在丝素蛋白/壳聚糖混合三维支架材料上的生长情况。 方法：将诱导后的兔骨髓间充质干细胞接种在丝素蛋白/壳聚糖支架材料上,检测细胞黏附率,倒置显微镜及扫描电镜观察细胞生长情况。 结果与结论：细胞黏附率随时间的延长而增加。倒置显微镜观察显示,丝素蛋白/壳聚糖支架上的细胞看不清,随着时间的延长,支架周围细胞增多,且有细胞伸入支架内;扫面电镜观察显示,细胞生长活跃、增殖分裂正常,细胞周围见颗粒状、丝状基质物质,细胞的微丝与支架材料黏附紧密;细胞不仅可以在材料表面贴附生长,并伸入材料之中。说明丝素蛋白/壳聚糖混合支架材料具有良好的细胞生物相容性。     

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.