多孔碳酸化羟基磷灰石水泥植入修复兔包容性骨缺损的力学分析

背景:采用发泡剂成孔技术,制成了有知识产权的新型骨修复材料多孔碳酸化羟基磷灰石,既保留了碳酸化羟基磷灰石骨水泥原位固化性能等所有的优点,同时又形成多孔结构。目的:通过动物实验观察新型的骨修复材料多孔碳酸化羟基磷灰石水泥修复骨缺损的力学效果。方法:30只新西兰大白兔,手术组25只在双侧股骨髁制备直径为5.5mm、深12mm的骨缺损动物模型,左侧植入多孔碳酸化羟基磷灰石骨水泥为实验组,右侧植入碳酸化羟基磷灰石骨水泥为对照组。非手术组5只,用于正常力学对照。将多孔碳酸化羟基磷灰石骨水泥和碳酸化羟基磷灰石骨水泥试件经模仿体液浸泡,检测力学强度。同时在手术组背肌内分别植入多孔碳酸化羟基磷灰石骨水泥和碳酸化羟基磷灰石骨水泥标准试件。分别于术后2,4,8,12,16周分批处死动物,进行试件骨内和肌内植入的力学实验分析和试件在模仿体液中浸泡后的抗压强度测试。结果与结论:多孔碳酸化羟基磷灰石骨水泥:2周时的骨内力学强度较低,4周时降到最低,8周时接近正常松质骨强度,12周时超过正常松质骨强度,16周时恢复到正常松质骨水平。碳酸化羟基磷灰石骨水泥:2周时骨内植入强度较多孔碳酸化羟基磷灰石骨水泥略高,4周时有所降低,8,12,16周时略升高,但是始终低于正常松质骨的强度。多孔碳酸化羟基磷灰石骨水泥和碳酸化羟基磷灰石骨水泥在SBF中浸泡的抗压强度变化不大。试件植入肌内后抗压强度变化非常显著。结果表明,多孔碳酸化羟基磷灰石水泥具有原位固化性能和一定的力学支撑作用,能作为自体骨移植的一种替代物修复骨缺损。     

多孔结构对碳酸化羟基磷灰石骨水泥溶解度的影响

目的探讨碳酸化羟基磷灰石骨水泥中多孔结构存在的意义及其对溶解性能的影响.方法合成能原位固化形成多孔结构的碳酸化羟基磷灰石骨水泥,并通过扫描电镜和模拟体液浸泡实验,观察其孔隙结构和失重率变化.结果多孔碳酸化羟基磷灰石骨水泥固化后的孔隙率为42%,平均孔径为153μm,孔之间以90μm左右的连通孔互相贯通,孔隙结构与松质骨相似.碳酸化羟基磷灰石的多孔结构增加了其比表面积,利于体液循环.经模拟体液浸泡后,其失重率的改变比普通型碳酸化羟基磷灰石骨水泥明显增加,二者差异显著.结论碳酸化羟基磷灰石骨水泥内部的多孔结构能促进其体外溶解.     

碳酸化羟基磷灰石水泥修复骨缺损的实验研究

目的通过动物实验观察一种新型的骨修复材料———碳酸化羟基磷灰石水泥修复骨缺损的效果。方法在10只杂种犬肱骨近端制作骨缺损动物模型,采用碳酸化羟基磷灰石水泥修复骨缺损,并以高温烧结羟基磷灰石陶瓷作为对照,分别于术后5天、4周、8周、12周和16周处死动物,通过X线和组织学观察其修复效果。结果碳酸化羟基磷灰石水泥完全充填骨缺损,界面与骨结合紧密,生物相容性良好,并且随着植入时间的延长可逐渐降解并被新生骨爬行替代,与骨整合为一体。而羟基磷灰石陶瓷不能紧密充填骨缺损,在实验期间与骨界面清晰,并且没有见到降解现象。结论碳酸化羟基磷灰石水泥具有原位固化性能,是一种较为理想的新型骨缺损修复材料。     

羟基磷灰石骨水泥中碳酸根存在的意义及其对溶解度的影响

目的探讨羟基磷灰石骨水泥中碳酸根存在的意义及其对溶解度产生的影响。方法制备碳酸化羟基磷灰石骨水泥，定量分析其固化产物晶体中的碳酸根结构。以磷酸钙骨水泥为对照组，分别预制直径为8mm、高为12mm的圆柱体试样。经模拟体液浸泡后，定期观察、测量每一试样的失重率，对照分析其体外溶解性的差别。结果碳酸化羟基磷灰石骨水泥固化产物的晶体中含有质量浓度5．6％的碳酸根，与自然骨的矿物成分更接近。随着时间的改变，材料在模拟体液中逐渐由白色转为微黄色，棱角逐渐变钝。体视显微镜下观察发现材料表面出现点、坑、片状溶蚀，碳酸化羟基磷灰石骨水泥较磷酸钙骨水泥更明显。失重率的检测表明，酸化羟基磷灰石骨水泥的失重率改变明显高于磷酸钙骨水泥。结论羟基磷灰石骨水泥中碳酸根的存在可增加其溶解度，加快降解速度。     

抗稀散性碳酸化羟基磷灰石骨水泥的研究

目的研制一种适合出血部位植骨的碳酸化羟基磷灰石骨水泥代骨材料.方法合成碳酸化羟基磷灰石骨水泥,在固化液中按重量比添加水溶性磷酸化壳聚糖,通过固化时间、抗压强度、残余百分比、X线衍射分析、傅里叶变换红外线分析等检测方法筛选合适的配方.结果添加壳聚糖对碳酸化羟基磷灰石骨水泥的固化时间影响不大,平均固化时间为11～15min,符合临床操作要求.但是对抗压强度影响较大,由39MPa降到31MPa.壳聚糖的添加量为0.4%(质量分数)时,抗稀散达到100%.大于0.5%时,骨水泥的操作性能明显下降.添加量为1.5%时,部分标本发现少量的磷酸八钙形成,羟基磷灰石的转化受到了影响.傅里叶变换红外线分析证明,其固化产物的晶格相中含有5.6%碳酸根成分.结论磷酸化壳聚糖能明显增加碳酸化羟基磷灰石骨水泥的黏度系数,增强钙离子的熬合作用,有效抑制血液渗入材料内部,保证骨水泥的固化反应顺利进行.当壳聚糖的添加量为0.4%时,材料表现出良好的操作性能,抗稀散性达到100%,适合出血部位的骨缺损修复.     

纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥与骨髓基质细胞的生物相容性*☆

背景：在前期的试验中,通过共沉淀法合成了纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合粉体,并与柠檬酸衍生物溶液调和制备出可生物降解、适当力学性能以及较好黏合强度的骨水泥。 目的：验证纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥材料对体外兔骨髓基质细胞黏附及增殖的影响,了解材料的生物相容性。 方法：应用共沉淀法制备纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合材料作为骨水泥的固相粉体,将柠檬酸衍生物配制成溶液作为液相调和制备黏合性骨水泥。培养兔骨髓基质细胞,传代扩增后接种到材料上,体外继续培养;以细胞加入无材料的培养皿培养为对照。 结果与结论：体外培养的兔骨髓基质细胞2 d后呈梭形成纤维细胞样,生长良好。有材料实验组细胞数显著多于对照组(P < 0.01)。扫描电镜下骨水泥材料具有良好的多孔网状结构,兔骨髓基质细胞伸出多个伪足样突起,紧密贴附在材料表面。两组细胞均保持持续增殖,2,4,6,和8 d实验组增殖均显著快于对照组(P < 0.01)。提示纳米羟基磷灰石/羧甲基壳聚糖-海藻酸钠复合骨水泥材料具有良好的生物相容性。      

多孔碳酸钙陶瓷与干细胞源性成骨细胞的相容性

背景：国内外的研究证实普通碳酸钙陶瓷作为骨替代材料时具有细胞支架作用。 目的：观察多孔碳酸钙陶瓷与成骨细胞的相容性,及作为骨组织工程支架的可能性。 方法：SD大鼠骨髓基质干细胞经矿化诱导培养、扩增并检测证实其已具成骨细胞表型后,分别与多孔碳酸钙陶瓷支架、普通羟基磷灰石陶瓷支架体外复合培养。 结果与结论：骨髓基质干细胞经体外诱导形成成骨细胞,钙结节、Ⅰ型胶原和碱性磷酸酶免疫染色结果阳性。多孔碳酸钙陶瓷支架材料与羟基磷灰石陶瓷材料皆有细胞附着生长,但多孔碳酸钙陶瓷支架材料细胞的黏附能力、增殖活力及成骨活性均强于羟基磷灰石陶瓷材料。提示多孔碳酸钙陶瓷支架材料与SD大鼠骨髓基质干细胞源性成骨细胞有良好相容性。     

大鼠成骨细胞与壳聚糖/羟基磷灰石复合支架降解产物的生物相容性

背景：人们对壳聚糖/羟基磷灰石复合多孔生物支架在体内的降解过程并非十分清楚,而且有关其降解产物对成骨细胞的影响研究也较少。 目的：分析大鼠成骨细胞与壳聚糖/羟基磷灰石复合多孔生物支架降解产物的生物相容性。 方法：将培养的第2代大鼠成骨细胞分别在壳聚糖/羟基磷灰石复合支架降解产物浸提液和含体积分数10%胎牛血清的DMEM培养液中培养,培养第2,4,6,8,10天分别对两组细胞做MTT细胞计数,采用联合会推荐法测定细胞碱性磷酸酶活性,采用BCA蛋白定量法测定总蛋白。 结果与结论：在壳聚糖/羟基磷灰石复合多孔生物支架降解产物浸提液中培养的大鼠成骨细胞增殖速度、细胞碱性磷酸酶活性、细胞总蛋白合成及碱性磷酸酶与总蛋白的比值明显高于在体积分数为10%胎牛血清DMEM培养液中培养的细胞(P < 0.05)。表明壳聚糖/羟基磷灰石复合多孔生物支架的降解产物不仅可促进大鼠成骨细胞的黏附、生长和增殖,还可增强其骨化功能,具有较好的生物相容性。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;组织工程全文链接：     

壳聚糖/纳米羟基磷灰石分层复合支架的生物相容性研究

制备壳聚糖/纳米羟基磷灰石(CS/nHA)分层复合支架,对其进行细胞毒性评价.分离培养大鼠软骨细胞接种于支架,相差显微镜和扫描电镜观察细胞的黏附及生长情况.动物皮下埋植试验观察其组织相容性.实验结果证实壳聚糖/纳米羟基磷灰石分层复合支架具有良好的生物相容性,有望成为较好的骨软骨组织工程支架.     

珊瑚转化羟基磷灰石应用于牙周组织工程的细胞相容性和细胞毒性**☆

背景：经处理后的珊瑚转化羟基磷灰石具有良好的生物相容性和可降解性,其三维相通的孔隙结构不仅可为种子细胞的黏附、增殖提供足够的内部空间和表面积,而且有利于营养成分的渗透和血管化形成。 目的：对珊瑚转化羟基磷灰石进行细胞相容性和细胞毒性的研究,以初步探讨其应用于牙周组织工程的可行性。 方法：将体外培养的人牙周膜细胞接种到珊瑚转化羟基磷灰石支架上体外三维复合培养,通过细胞计数方法和扫描电镜观察人牙周膜细胞在珊瑚转化羟基磷灰石支架上的附着、生长情况,并设立阴性对照组和阳性对照组,采用MTT测试法和碱性磷酸酶活性检测法评估稀释浓度分别为100%,50%,10%,1%的珊瑚转化羟基磷灰石浸提液对人牙周膜细胞增殖及功能表达的影响。 结果与结论：珊瑚转化羟基磷灰石具有良好的多孔网状结构,人牙周膜细胞在珊瑚转化羟基磷灰石支架上生长旺盛,伸展充分,而不同浓度的材料浸提液对人牙周膜细胞的生长、增殖及碱性磷酸酶活性的影响差异均无显著性意义。提示珊瑚转化羟基磷灰石具有良好的三维空间结构和细胞相容性,且无细胞毒性,有望用作牙周组织工程的支架材料。关键词：珊瑚转化羟基磷灰石;细胞相容性;细胞毒性;支架材料;组织工程 缩略语注释：CHA：coral hydroxyapatite,珊瑚转化羟基磷灰石;HPDLCs：human periodontal ligament cells,人牙周膜细胞 doi:10.3969/j.issn.1673-8225.2012.16.025      

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.     

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.