基于计算流体力学的小血管生物反应器设计

目的：设计一套能构建内壁直径为2mm的组织工程小血管的生物反应器。方法：根据计算流体力学原理和方法对组织工程小血管托架材料进行分析，设计一套用于培养2mm小血管的生物反应器。采用压注成型技术制作了小血管的托架。结果：确定了硅胶管的尺寸结构并获得了成型产品，设计完成了培养室内相应的辅助结构，使整个反应器系统能够对PGA-细胞材料复合物进行动态培养。结论：小血管托架的流体力学仿真分析是合理的，在此基础上构建的血管生物反应器性能稳定、可靠。     

人血管平滑肌细胞种植构建工程生物血管的实验研究

了解猪血管去细胞后平滑肌细胞种植情况,为猪血管用于血管组织工程提供资料。取猪颈动脉,生物酶预处理猪血管,在自行设计制作的新型动力性生物反应器中,用原代培养的人平滑肌细胞种植在去细胞血管基质材料内,HE染色及银染检测平滑肌细胞种植效果。结果表明生物酶预处理血管后,HE染色及银染检测可见血管腔平滑肌细胞形态正常,沿血管长轴分布,提示经生物酶预处理的猪血管人平滑肌细胞能成功种植,可望构建实用的组织工程血管。     

生物反应器体外构建组织工程化尿路肌性管腔

背景：理想的组织工程尿道替代物应具有良好的力学特性,足以承受长时间的尿液排泄冲击,而静态培养的尿路肌性管腔强度不佳。已有研究表明,力学刺激能够促进细胞生长和细胞外基质的分泌。 目的：探讨生物反应器内构建组织工程化尿路肌性管腔的可行性。 方法：酶消化法获取脂肪干细胞,经体外培养和扩增后,流式细胞技术检测细胞表面抗原,将脂肪干细胞接种于聚羟基乙酸上,形成细胞-材料复合物,体外培养1周后,将其置于生物反应器内培养,实验组予以动态力学刺激培养;对照组为静态培养,先采用基础培养基培养3周,而后用成肌诱导培养液诱导4周,行大体观察及组织学检测。 结果与结论：流式细胞仪检测细胞表面CD90,CD44,CD105表达率分别为99.42%,98.12%,93.27%;CD34,CD45表达率分别为4.92%和0.38%,实验组培养的肌性管腔色泽明亮,管腔圆润,免疫组化染色显示,细胞材料复合物在诱导4周后,细胞表达结蛋白和α-平滑肌肌动蛋白阳性,细胞材料复合物胶原成分多。对照组构建的肌性管腔色泽暗淡,管腔轻度塌陷,细胞材料复合物胶原成分较少。提示脂肪干细胞复合聚羟基乙酸材料在生物反应器内动态培养可构建具有良好结构的尿路肌性管腔。 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;组织工程全文链接：     

骨髓间充质干细胞-聚乙醇酸支架复合体种植动物皮下构建组织工程化小口径血管

背景：课题组的前期工作已证实骨髓间充质干细胞可以诱导分化为血管内皮细胞和血管平滑肌细胞,并证实所诱导的细胞和胶原包埋的聚乙醇酸支架具有良好的组织相容性。 目的：探讨利用动物皮下作为生物反应器构建小口径组织工程化血管的可行性。 方法：骨髓间充质干细胞诱导分化为血管平滑肌样细胞和血管内皮样细胞,分层种植于胶原包埋聚乙醇酸支架表面,然后将细胞-支架复合体种植于动物皮下,构建小口径组织工程化血管。 结果与结论：人工血管组织学观察见管壁结构清晰,其大体结构和天然血管相似,可承受26.6 kPa的血管腔内压力不破裂。皮下培养8周免疫荧光观察Brdu标记的部分细胞核呈现明亮的黄绿色荧光。结果说明利用动物的皮下作为生物反应器,采用静态培养的方式构建小口径组织工程化血管是可行的。     

自制双腔生物反应器构建组织工程骨软骨复合体的体外性能

背景：关节软骨损伤往往并发软骨下骨损伤形成骨软骨复合缺损,其治疗仍为骨科急待解决的问题,利用组织工程学构建骨软骨复合体为治疗该类疾患提供了新思路。 目的：探讨利用自行设计制造的双腔搅拌式生物反应器构建一体化组织工程骨软骨复合体的可行性。 方法：在双腔搅拌式生物反应器内对复合于β-磷酸三钙支架材料的羊骨髓间充质干细胞同时进行成骨和成软骨诱导,并根据施加剪切应力分为动态培养组和静态培养组。利用MTT试验、RT-PCR和扫描电镜检测骨髓间充质干细胞体外增殖和诱导分化情况。 结果与结论：MTT试验和扫描电镜结果显示,骨髓间充质干细胞增殖良好。成骨和成软骨相关基因RT-PCR检测结果表明,骨髓间充质干细胞诱导分化良好,动态培养组要优于静态培养组。提示利用自行设计制作的双腔搅拌式生物反应器进行骨软骨复合体的体外构建是可行的,力学刺激环境下的构建效果要优于静态环境。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;组织工程全文链接：     

生物反应器在血管组织工程中的应用及进展

论述生物反应器的种类与发展,以及其在血管组织工程种子细胞培养和组织工程血管构建方面的主要研究进展。根据生物反应器领域的发展,分析了生物反应器对种子细胞培养、扩增的影响,尤其是对干细胞培养、定向分化方面的影响;阐述生物反应器内种植细胞的方法,以及机械力学对细胞生长、黏附的影响;探讨生物力学与血管构建的关系。最后提出生物反应器未来的发展趋势。     

血管组织工程的研究与进展

背景：血管组织工程是指利用血管壁的正常细胞和生物可降解材料来制备、重建和再生血管替代材料的科学。近年来,组织工程学技术的发展推动了组织工程化血管的研究,已成为今后血管替代物的重要方向。 目的：综述血管组织工程的相关临床及基础研究进展。 方法：检索SCI数据库2001/2010有关血管组织工程的文献,检索词为“组织工程血管(tissue-engineered vascular);组织工程(tissue engineering);血管(vascular);支架材料(scaffold materials);支架(scaffolds);种子细胞(seed cell);细胞外基质(extracellular matrix, ECM);血管支架(vascular scaffold);高分子材料(polymer materials);复合材料(composite materials);纳米(nanometer);生物材料(biological materials)”,对血管组织工程的临床及基础文献进行分析。 结果与结论：血管组织工程研究的内容主要有种子细胞、细胞外基质替代物以及组织工程血管三维培养。血管组织工程所应用的种子细胞包括自体血管壁细胞、胚胎干细胞和骨髓间充质干细胞,还包括内皮细胞,平滑肌细胞及成纤维细胞等众多组织细胞。在组织工程血管构建中血管组织微环境是活细胞在体外生长所需的支持物,是种子细胞生长增殖的三维空间,便于细胞黏着、生长、进行新陈代谢。因此,组织工程血管需要具有良好的生物相容性,可塑性强,来源广泛,有一定的抗张强度和无免疫原性的支架材料。根据来源和性能,目前研究应用的材料分为天然生物生材料和合成材料两种。     

可注射藻酸盐支架与人骨髓基质干细胞的体外复合培养*☆

背景：目前可注射组织工程骨的研究主要限于动物实验,若人骨髓基质干细胞与藻酸盐生物相容性良好,可注射组织工程骨将是极具前途的临床治疗手段。 目的：体外观察人骨髓基质干细胞与可注射支架藻酸钙凝胶的生物相容性。 方法：实验组将第2代人骨髓基质干细胞与藻酸钙凝胶复合培养,对照组单纯接种骨髓基质干细胞。倒置相差显微镜、扫描电镜观察各组细胞形态及增殖情况,MTT法半定量检测细胞增殖情况。 结果与结论：倒置显微镜下见实验组细胞生长良好,与对照组无明显差异。扫描电镜见骨髓基质干细胞在藻酸钙表面贴附、增殖良好,第6天时细胞已跨越微孔表面或向孔内生长。MTT法显示与对照组相比,实验组细胞增殖能力不受影响。结果初步表明藻酸钙与人骨髓基质干细胞体外生物相容性较好。      

体外构建人工仿生骨膜

背景：小肠黏膜下层既具有良好的生物相容性和降解性,又富含多种生长因子,能明显促进细胞的黏附、增殖及分化,在国外已被广泛应用于骨与软骨、血管、皮肤、膀胱、平滑肌及胰岛等组织的修复,且已表现出良好的组织工程化细胞支架性能。 目的：探讨兔骨髓间充质干细胞经体外诱导成成骨细胞与猪小肠黏膜下层复合构建组织工程骨膜的可行性。 方法：采用贴壁筛选法分离2周龄健康新西兰大白兔骨髓间充质干细胞,并进行体外扩增培养、诱导分化及鉴定。将经成骨诱导分化的骨髓间充质干细胞与猪小肠黏膜下层复合构建组织工程骨膜,观察细胞在生物材料上的附着、生长、增殖情况。 结果与结论：接种5 d后,细胞散在附着于小肠黏膜下层材料上,细胞形态呈圆形,细胞之间无连接;10 d后细胞之间形成桥粒连接,成骨细胞伸出突起,与小肠黏膜下层贴附;15 d后细胞增殖,分泌基质,在小肠黏膜下层表面形成多层细胞组成的复层膜样结构。表明将骨髓间充质干细胞诱导成成骨细胞后与猪小肠黏膜下层复合可构建组织工程骨膜,有可能成为理想的组织工程支架材料。     

组织工程生物反应器嵌入式实时检测控制系统的设计

背景:组织工程生物反应器通过模拟体内环境,可为细胞或组织提供适宜的生长条件,并能培养出与体内结构和功能相似的三维细胞或组织。目的:对水平旋转生物反应器培养细胞或组织的环境需求进行分析,针对其特殊的环境需求提出了基于Linux和ARM9嵌入式处理器的生物反应器检测控制系统设计。方法:以系统对实验室自制的生物反应器进行控制监测。实验主要完成支架材料制备,实验用主要仪器(自动台式灭菌器,气液膜,液液膜电子分析天平等)准备,实验材料-骨髓间充质干细胞的原代、传代培养及制备,以及系统对反应器的转速和蠕动泵控制,温度,pO2,pH值的检测。结果与结论:与单片机控制检测系统相比,改进系统驱动控制方式,提高了控制精度,增强检测灵敏度。同时新设计增加了养分压以及pH值检测,进一步完善了反应器的功能。     

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.     

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.     

The universal muscular chain reaction,muscle spasm,Torsions, ruptures and extravasations. Chameleons of pathology and some manifestations of simple muscular disorders

Most bodily functions require the coordinated actions of complementary and supplementary paired muscle groups. Where this essential muscular cooperation is lacking, hollow organs may burst and others become literally screwed up, giving rise to many similar spastic diseases such as Torticollis, Twisted ovarian cyst, Torsion of the Testis, Volvulus of the intestines, Varicose Veins, Megacolon, Aortamegaly, Scoliosis, Erb's Palsy, Peyronie's Disease, Main-en-Griffe, Undescended Foot (Pes Cavus), Talipes, Strabismus. Spasm is “panenepidemic” and unclassified examples of Torsion Dystonia and Dyskinesia really are as common as debt and taxes.     

'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.     

Hypo- und Hypermagnesämie aus kardiologischer Sicht

Zusammenfassung Eine Reihe pathologischer Zustände bedingen Magnesiummangel. Zustände mit Hypermagnesämie sind ebenfalls bekannt, doch wesentlich seltener. Für den Kardiologen beachtenswert ist, daß unter Therapie mit bestimmten Diuretica bei Herzinsuffizienz, bei Herzinfarkt, Kardiomyopathie, Digitalisintoxikation und bestimmten Herzrhythmusstörungen Hypomagnesämie beobachtet wurde. Leider kann in der klinischen Routine nur ein extracelluläres Magnesiumdefizit durch Serumbestimmungen gemessen werden; über Magnesiummangel einzelner Organe kann nichts ausgesagt werden. Hinweise für Magnesiummangel geben aber neben der Messung des Serumspiegels Anamnese, klinischer Befund, bestimmte EKG-Veränderungen wie auch evtl. Hypokalämie, ein Zustand, bei dem sich oft — besonders bei Aldosteronismus — parallele Veränderungen zeigten.Tierexperimente deuten darauf hin, daß infarktähnliche Läsionen unter Magnesiummangel entstehen, doch ob Herzinfarkt beim Menschen durch Magnesiummangel ausgelöst werden kann, ist noch ungeklärt. In Leichenherzen zeigte sich im Infarktgebiet neben Calciumakkumulation signifikanter Magnesiumverlust, wobei unklar blieb, ob sich Ursache oder Folge des Infarktes widerspiegelten. Falls ein ursächlicher Zusammenhang besteht, ist er im Myokardstoffwechsel selbst zu suchen, wie bei der Alkoholkardiomyopathie, wo myokardialer Magnesiummangel zumindest als pathogenetischer Teilfaktor anerkannt wird. Andererseits versucht man aber auch Beziehungen zwischen Atherosklerose, Blutgerinnung und Hypomagnesämie herzustellen, in der Meinung, daß Magnesiummangel auch über den coronaren Pathomechanismus des Herzinfarktes wirken könnte. Sicher scheint, daß gewisse EKG-Veränderungen und Herzrhythmusstörungen durch einen irritierten Magnesiumhaushalt bedingt sein können, da sie bei Gabe bzw. Entzug von Magnesium verschwinden. Daß Magnesiummangel die Glykosidtoleranz verringert, wird tierexperimentell bestätigt. Unter Hypomagnesämie bewirkt Acetylstrophanthidin eher und länger Rhythmusstörungen als ohne, außerdem lassen diese sich durch Magnesiumgaben eliminieren. Da in gewissen Fällen spontane und digitalisinduzierte Herzrythmusstörungen durch Magnesiuminjektionen beseitigt wurden, scheint Magnesium als Therapeuticum angebracht. Einsatz verschiedener Magnesiumsalze bei Angina pectoris, degenerativen Herzerkrankungen und Herzinsuffizienz ohne geprüften und offensichtlich gestörten Magnesiumhaushalt ist fragwürdig, weil keine eindeutigen klinischen Erfolgsbeweise vorliegen. Immerhin mag es aber larvierte, durch Serumbestimmungen nicht erfaßbare Mangelzustände geben. Allgemein erscheint es aus kardiologischer Sicht ratsam, den Magnesiumhaushalt zu überwachen und in entsprechenden Fällen auszugleichen, um möglichen Myokardläsionen oder fatalen Herzrhythmusstörungen entgegenzuwirken.     

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 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.