新短肽P17-骨形态发生蛋白2/胶原基质矿化磷灰石材料生物活性的评价

文题释义：胶原基质矿化磷灰石：具有良好的生物相容性,不产生排斥反应,降解速度与成骨的速度相适应,其降解不会影响周围环境的pH值。该材料在微米尺度上具有互联孔洞结构,孔隙尺寸为100-500 µm,孔隙率为70%-90%,结构和成分与自体骨相似,能够更好的诱导自体骨生长,具有良好的骨修复作用,其机械耐受性、可塑性、强度接近松质骨。 新短肽P17-骨形态发生蛋白2：通过FMOC/tBu固相多肽合成法合成的具有17个氨基酸的新型活性短肽中包含磷酸化的丝氨酸及天冬氨酸,能够极好地模拟天然骨基质的促发及指导矿化的功能,在局部形成偏酸环境,促进局部的钙磷沉积、成核和生物自组装矿化。短链多肽活性位点能充分暴露并与细胞表面受体结合,生物活性更强。 背景：胶原基质矿化磷灰石材料具有仿生的化学组成及良好的生物学性能,已被用于某些骨缺损修复;新短肽P17-骨形态发生蛋白2具有良好的生物相容性和成骨诱导生物活性,因此将新短肽P17-骨形态发生蛋白2与胶原基质矿化磷灰石材料制备成复合支架材料可望提升骨修复效率和效果。 目的：探讨新型P17-骨形态发生蛋白2/胶原基质矿化磷灰石复合材料的生物活性。 方法：将兔骨髓间充质干细胞分别接种于新型P17-骨形态发生蛋白2/胶原基质矿化磷灰石复合材料与胶原基质矿化磷灰石材料上,培养3,7 d后,利用RT-PCR检测细胞碱性磷酸酶 mRNA相对表达。将新型P17-骨形态发生蛋白2/胶原基质矿化磷灰石复合材料(实验组)与胶原基质矿化磷灰石材料(对照组)分别埋置于SD大鼠皮下,植入12,35 d后进行Masson染色后组织学分析。将新型P17-骨形态发生蛋白2/胶原基质矿化磷灰石复合材料(实验组)与胶原基质矿化磷灰石材料(对照组)分别植入日本大耳白兔下颌骨箱状缺损处,植入5,15周后进行大体与X射线检查。实验经中国医科大学附属口腔医院伦理委员会批准。 结果与结论：①复合材料组培养7 d的碱性磷酸酶mRNA表达高于胶原基质矿化磷灰石组(P < 0.05);②皮下埋植实验显示两组材料和组织界面均未引起明显的急性炎症反应,植入后35 d实验组可见更多的纤维细胞与材料嵌合;③骨缺损修复实验中,大体观察显示两种材料均具有良好的骨修复能力,植入5周时缺损区已有缩小趋势,植入15周缺损表面比较平整;X射线检查显示与对照组相比,实验组缺损区缩小趋势更明显;④结果表明,新型P17-骨形态发生蛋白2/胶原基质矿化磷灰石复合支架材料具有比胶原基质矿化磷灰石更为优良的生物活性与骨缺损修复能力。 ORCID: 0000-0002-1196-5954(张雪) 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     

载TGF-β1纳米粒的胶原/丝素蛋白复合支架的制备与表征

目的 构建一种载转化生长因子β1(TGF-β1)纳米粒的双层胶原/丝素蛋白复合支架.方法 制备载TGF-β1的壳聚糖-肝素(Ch-Hep)纳米粒,检测其形态、粒径、Zeta电位和包封率.制备不同胶原和丝素蛋白质量比(2∶8、3∶7、7∶3、8∶2、10∶0)的5种胶原/丝素蛋白复合材料,分别检测其吸水率、孔隙率、热水溶失率和生物相容性;选择其中2种综合性能良好的复合材料分别作为复合支架的疏松层和致密层,构建载TGF-β1纳米粒的双层胶原/丝素蛋白复合支架,观察其形态并进行体外释放动力学研究.结果 Ch-Hep纳米粒的平均粒径为(718.2±73.6) nm,Zeta电位为(25.5±0.8) mV,对TGF-β1的包封率为(84.82±1.57)％.随着胶原/丝素蛋白复合材料中胶原含量的增加,材料的吸水率、孔隙率逐渐增加,热水溶失率逐渐降低;5种材料对骨髓间充质干细胞(BMSCs)均有促生长和增殖的作用.综合考虑后选用质量比为3∶7和7∶3的胶原/丝素蛋白复合材料分别作为复合支架的致密层和疏松层,构建的胶原/丝素蛋白复合支架为双层结构,一侧结构致密,另一侧疏松多孔.体外释放动力学研究表明,复合支架对TGF-β1具有定向时空控制性释放作用.结论 载TGF-β1纳米粒的双层胶原/丝素蛋白复合支架对TGF-β1具有良好的时空控制释放作用,有望作为生长因子的控缓释支架材料应用于软骨组织工程.     

纳米羟基磷灰石/胶原复合材料的制备及生物学评价

低温下,水热合成的纳米羟基磷灰石浆液与中性胶原溶胶混合,升温使羟基磷灰石晶体与胶原自组装形成复合凝胶,经洗涤、冻干,获得羟基磷灰石/胶原复合材料。采用XRD,FTIR和TEM对复合材料的特性进行研究,结果表明:羟基磷灰石晶体尺寸为16nm×40nm;复合材料的晶相组成,羟基磷灰石晶体大小、胶原纤维的结构等都与天然骨相似。采用骨髓嗜多染细胞微核实验、致敏实验、以及细胞毒性实验对复合材料进行生物相容性评价。小鼠骨髓微核率为1.6±0.9,与阴性对照组无显著性差异,和阳性对照组有显著性差异。最大剂量法实验表明复合材料无致敏作用。滤膜扩散实验证明复合材料无细胞毒性。复合材料骨内植入的组织学分析表明,4周时,在材料和骨组织的界面处有新骨生成,12周时,界面处有大量的新骨形成。皮下植入44周后,材料降解成碎片,纤维组织长入材料降解区域。本研究制备的纳米羟基磷灰石/胶原复合材料具有体内降解和促进骨形成的能力。不具有致染色体畸变作用、皮肤致敏作用和细胞毒性,是一种生物相容性良好的潜在的骨替换材料。     

纳米相羟基磷灰石/胶原复合材料研究进展

综述羟基磷灰石（hydroxyapatite,HA）/胶原复合材料的研究进展,着重阐述自组装纳米相羟基磷灰石/胶原复合材料的制作方法、结构特点、体内植入后修复骨缺损的效果及降解过程.基于仿生学设计的纳米相羟基磷灰石/胶原复合材料,其HA纳米晶体约50～100nm,HA的C-轴沿胶原纤维排列,形成片状包绕胶原纤维束,HA和胶原分子之间为牢固的化学键性结合,为自组装的纳米结构,和自然骨中钙化的胶原相同.复合材料体内植入后降解和骨替代的过程与骨的改建过程相似.纳米相羟基磷灰石/胶原复合材料具有生物降解性高、表面能大、生物活性好、生物相容性好等特点,作为骨修复和重建材料具有更好的前景.     

纳米相羟基磷灰石/胶原复合材料研究进展

综述羟基磷灰石(hydroxyapatite,HA)/胶原复合材料的研究进展,着重阐述自组装纳米相羟基磷灰石/胶原复合材料的制作方法、结构特点、体内植入后修复骨缺损的效果及降解过程。基于仿生学设计的纳米相羟基磷灰石/胶原复合材料,其HA纳米晶体约50～100nm,HA的C-轴沿胶原纤维排列,形成片状包绕胶原纤维束,HA和胶原分子之间为牢固的化学键性结合,为自组装的纳米结构,和自然骨中钙化的胶原相同。复合材料体内植入后降解和骨替代的过程与骨的改建过程相似。纳米相羟基磷灰石/胶原复合材料具有生物降解性高、表面能大、生物活性好、生物相容性好等特点,作为骨修复和重建材料具有更好的前景。     

纳米微球负载抗生素/羟基磷灰石复合支架的缓释性能及治疗感染性骨缺损的研究

目的 评价新型纳米微球负载抗生素/羟基磷灰石复合支架材料的体外缓释性能及治疗感染性骨缺损的疗效。方法 运用HPLC法检测不同时间点药物的体外释放量。建立兔胫骨感染性骨缺损动物模型24只,共分为4组：a组动物仅单纯清创;b组植入1 mg Lev/PMMA;c组植入n-HA/PU;d组植入1 mg Lev/n-HA/PU。在植入材料术后6周、12周观察放射学、组织病理学,Micro CT评价新骨生成。评价新型复合材料控制感染、诱导成骨能力、治疗感染性骨缺损的效果。结果 1 mg Lev/n-HA/PU组比1 mg Lev/PMMA组释放的抗生素更多（P<0.05）,缓释性能表现更好。单纯清创组X线表现出局部骨破坏、死骨形成。1 mg Lev/n-HA/PU组无明显骨破坏。Micro CT发现1 mg Lev/n-HA/PU组材料周围新生骨小梁数量与其余三组比较,差异有统计学意义（P<0.05）,结论 新型载抗生素复合支架材料具有良好的缓释性能、抗感染能力、骨诱导能力,可有效治疗胫骨感染性骨缺损。     

可注射壳聚糖/纳米羟基磷灰石/胶原复合材料的生物相容性实验研究

目的　评价可注射壳聚糖/纳米羟基磷灰石/胶原复合材料的组织相容性,以及探讨材料负载骨髓基质干细胞进行骨修复的可行性。 方法　壳聚糖/纳米羟基磷灰石/胶原材料与BrdU标记的rBMSc混合,注射入大鼠皮下,于皮下植入后24 h,14 d和28 d分别断颈处死大鼠,进行大体观察、HE、MASSON染色、免疫组化染色。 结果　壳聚糖/纳米羟基磷灰石/胶原材料在室温呈液态,经1 ml注射器26号针头注射入大鼠皮下后,材料在体内可以迅速原位成形成凝胶状态,并在原位保持形状,BrdU标记的rBMSc弥散于材料中,28 d的免疫组化结果显示细胞存活良好。 结论　壳聚糖/纳米羟基磷灰石/胶原复合材料具有良好的组织相容性,是一种良好的负载干细胞的骨组织工程支架。     

聚乳酸/壳聚糖复合支架材料的生物相容性研究

为改善聚乳酸作为骨组织工程支架材料降解速率过快、亲水性差和降解产物呈酸性等缺点，本研究制备了一系列高孔隙率的聚乳酸／壳聚糖三维多孔复合支架材料，通过软骨细胞培养、动物皮下和肌肉植入试验对其进行了生物相容性研究。软骨细胞培养试验表明软骨细胞能在复合支架材料贴附增殖，材料无明显毒性；植入试验结果显示纯聚乳酸在体内2个月左右已经降解吸收，失去力学强度，复合材料三个月后仍能保持一定的力学强度和形状，而且组织切片也同时表明复合材料的炎症反应远远低于纯聚乳酸材料。     

植入型表阿霉素缓释药膜的制备及体内抑瘤活性

制备用于实体肿瘤局部治疗的植入型表阿霉素缓释药膜.采用复乳.溶剂挥发法制备聚乳酸载表阿霉素缓释微球,用交联复合法制备含载药微球的植入型胶原药膜;用扫描、透射电镜、共聚焦及粒度仪等考察微球和药膜的形貌、结构、粒径及体外释放;用H22肝癌荷瘤动物模型评价其体内抑瘤效果.结果:载药微球粒径分布均匀,外观圆整,平均粒径为5.8μm;微球的载药量4.39%,包裹率为37.2%;10h内载药微球在模拟体液中的累积释放率为35%;腹腔注射载药微球与瘤体局部植入胶原药膜对H22肝癌均有明显的抑瘤效果;微球注射与药膜植入两种不同给药方式对H22肝癌抑瘤效果也存在显著性差异(P<0.05).植入型载表阿霉素缓释胶原膜具有良好的药物局部缓释特性,在肿瘤的术后局部治疗方面具有良好的临床应用前景.     

旋转反应器胶原支架的制备及复合软骨细胞修复骨软骨损伤的初步研究

目的以胶原为原料开发一种小型胶原支架材料,尝试是否适合旋转反应器来复合软骨细胞,并探讨复合细胞后修复软骨损伤的效果。方法成年猪跟腱中提取胶原,制备胶原支架,进行细胞毒性检测和生物相容性分析。将其切成1 mm~3小块,置于旋转培养器中与软骨细胞共培养,倒置相差显微镜观察细胞贴附效果。建立兔关节软骨缺损模型,编号后,将14只新西兰大白兔随机分为2组:支架材料组(n=8),兔膝关节软骨缺损区植入胶原支架材料和软骨细胞;空白对照组(n=6),不进行任何植入处理。进行HE染色后观察。结果胶原支架呈瓷白色,表面空隙均匀,无细胞毒性,生物相容性良好,但在体内降解较快。在旋转反应器中,支架可以与软骨细胞良好结合。胶原支架植入动物体内12周,虽未完全修复缺损,但已有少量软骨细胞在缺损处出现,修复效果优于对照组。结论制备的胶原支架复合软骨细胞短期内有一定的修复软骨缺损的能力,长期效果欠佳,可能与胶原支架在体内过快降解有关,尚需对制备方法进行改进。     

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.