硫酸钙/羟基磷灰石可注射性骨替代物凝固时间的影响因素

目的分析可注射性硫酸钙/羟基磷灰石骨替代物凝固时间的影响因素。方法分别在改变凝固条件后,或改变羟基磷灰石含量,液固比,固化液成分后用 Gillmore 双针法测定硫酸钙/羟基磷灰石骨替代物凝固时间的变化。结果当减低液固比,提高羟基磷灰石含量或升高温度时可注射性硫酸钙／羟基磷灰石骨替代物凝固时间缩短,使用固化液欧乃派克或蒸馏水对其凝固时间的影响无显著性差异。结论硫酸钙/羟基磷灰石骨替代物的凝固时间通过改变影响因素可以达到临床操作的要求。     

注射型纳米羟基磷灰石/聚酰胺生物活性骨修复材料的研究

利用羟基磷灰石纳米晶体与聚酰胺66复合，构成新型生物活性骨修复材料，探讨用于不规则骨缺损修复的注射型纳米复合人工骨的生物学特性及骨组织修复能力。对该材料进行X射线衍射分析、凝结时间、凝结强度等研究及动物实验研究，评价该材料的组织相容性和缺损骨组织的修复能力。结果表明该材料的X射线衍射谱与羟基磷灰石／聚酰胺复合材料的X射线衍射谱相同；液固比为0．5时复合材料易于注射；在生理盐水或血液中的凝固时间为25～30min；在生理盐水中固化48h后，抗压强度为37MPa。植入后牙槽嵴表面软组织愈合良好，实验侧牙槽嵴修复高度明显大于对照侧；组织形态学观察，4周时材料周围未见有成骨迹象，16周时材料被包裹并在与其相连的区域出现成骨早期的片状结缔组织。研究证实，以一定的复合比例构成的纳米羟基磷灰石／聚酰胺66复合材料组织相容性良好，可以注射方式实现对不规则骨缺损的修复。     

载药复合纳米人工骨的注射、凝固、抗稀散性及药物缓释放的性能研究

目的 考察纳米羟基磷灰石(n-HA)的载药情况,并复合α-半水硫酸钙(CSH)构建复合人工骨材料,比较载药与未载药的复合人工骨的各方面性能,以及对复合材料的药物缓释放情况进行考察.方法 用离子交换法把阿莫西林载入n-HA中,与未载药的n-HA用UV-vis和TEM进行对比检测.再分别以质量比1:1与CSH复合,并对两组复合人工骨的各方面性能进行对比考察.把复合材料浸泡于生理盐水,每天更新浸泡液,测试骨水泥中药物的释放效果.结果 n-HA可有效地运载入阿莫西林.载药组的注射性能优于未载药组,凝固时间、抗稀散性相差不大.药物在浸泡数天内持续释放.结论 n-HA可以作为药物缓释放载体,以质量比1:1与CSH构建复合人工骨材料,其注射性能、凝固时间、抗稀散性均能符合临床要求.     

nHA/α-CSH复合植骨材料的研制及其固化时间和抗压强度测定

目的构建纳米羟基磷灰石(nHA)/α型半水硫酸钙(α-CSH)复合植骨材料并对其固化性能和机械强度进行观测。方法测试不同液/固比、不同二水硫酸钙(CSD)促凝剂含量条件下复合植骨材料的固化时间和压缩强度,并进行X线衍射(XRD)和扫描电镜(ESM)观察。结果复合骨水泥的固化时间随着nHA的增加而增加,随着CSD的增加而降低。含20%nHA、80%α-CSH的骨修复材料固化时间为(169±36)min;而含5%nHA、20%CSD、75%α-CSH的骨修复材料固化时间为(6±1.1)min。抗压强度随着nHA的增加而降低。纯α-CSH的平均压缩强度为(12.3±2.4)MPa,而含20%nHA、80%α-CSH的骨修复材料为(4.8±0.6)MPa。XRD检测显示固化后α-CSH转化为CSD,没有其他物质生成。ESM显示固化后nHA镶嵌在了CSD的晶体结构上,呈两相结构。结论通过调节nHA、α-CSH和促凝剂CSD的含量可以控制复合骨水泥的固化时间和机械强度,为临床应用提供适宜条件。     

可塑型生物活性骨修复材料的制备及性能表征

背景：国外研制的可注射性硫酸钙骨替代材料具有操作简便、生物相容性好、能够注射入骨缺损处、原位固化、适应骨缺损进行塑形等优点,但价格昂贵。 目的：研究以α-半水硫酸钙为主要成分可塑型骨修复材料的最佳制备参数,并对其性能进行研究和表征。 方法：使用汽热法制备粉末,将α-半水硫酸钙粉末与透明质酸钠固化液分别按液固比0.2,0.25,0.3,0.35,0.4 mL/g混合,制备可注射人工骨材料,检测其注射性能、凝固时间和抗压强度;根据检测结果选择最佳液固比0.3 mL/g,在α-半水硫酸钙粉末中分别加入质量分数为1%,2%,3%的二水硫酸钙粉末,制备可注射人工骨材料,检测其注射性能、凝固时间和抗压强度,同时检测可注射骨材料的生物安全性。将液固比为     0.3 mL/g并加入2%二水硫酸钙制备的可注射人工骨材料植入巴马小型猪胸骨缺损模型,植入后8,16,24周进行组织学观察。 结果与结论：α-半水硫酸钙粉末与透明质酸钠固化液液固比为0.3 mL/g,加入质量分数2%二水硫酸钙粉末制备的可注射人工骨材料,初凝时间为4.0-5.0 min,终凝时间为8.0-9.0 min,抗压强度(8.93±0.23) MPa,具备良好的注射性能,符合临床要求的凝固时间及作为非负重骨缺损修复要求的抗压强度,并具有良好的生物安全性。动物植入实验表明可注射人工骨材料通过自身降解,可为新生骨的爬行替代提供空间,具有一定的成骨活性。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     

纳米羟基磷灰石/硫酸钙人工骨在模拟体液浸泡环境下的行为研究

目的 将纳米羟基磷灰石与半水硫酸钙组合构建一种可注射的人工骨材料,研究其在模拟体液环境中的降解与物质变化,并探讨该变化与材料成骨活性的关系.方法 采用模拟人体体液SBF9#浸泡两种晶体物质和不同成分组合的复合材料样品,测定失重率、钙磷元素释放速率,并对材料表面形态和晶体变化作扫描电镜观察和XRD分析.结果 纯羟基磷灰石在早期快速失重后保持稳定,其余材料均稳定降解,复合材料的HA含量越高,降解速率越快.纳米羟基磷灰石组的溶液Ca浓度始终较低;各组均有P元素释出,但随时间减少.XRD分析发现复合材料浸泡中CS峰下降,HA峰强度增高.扫描电镜观察到浸泡后复合材料表面呈现新的晶体形态.结论 CSD与HA在SBF环境下可能出现表面Ca、P的释放-吸附动态过程,材料的降解速度主要取决于CSD,可通过调节成分配比而加以控制.     

可注射性硫酸钙/羟基磷灰石骨替代物抗压强度的影响因素

目的分析可注射性硫酸钙／羟基磷灰石骨替代物抗压强度的影响因素。方法用材料力学测试机，①测定含10％、20％、30％、40％、50％质量HA的α-半水硫酸钙分别与欧乃派克按照0．4ml／g的液固比混合后的抗压强度；②测定含40％质量HA的α-半水硫酸钙与欧乃派克按照液固比分别为0．350、0．375、0．400、0．425、0．450或0．475混合后的抗压强度；③测定含40％质量HA的α-半水硫酸钙按照0．4ml／g的液固比与不同的固化液即欧乃派克或蒸馏水混合后的抗压强度。结果当增加液固比，提高羟基磷灰石含量时可注射性硫酸钙／羟基磷灰石骨替代物抗压强度下降，使用固化液欧乃派克或蒸馏水对其抗压强度的影响无显著性差异。结论对可注射性硫酸钙／羟基磷灰石骨替代物抗压强度通过改变影响因素可以满足临床操作的要求。     

新型聚乳酸与纳米羟基磷灰石复合人工骨的性能测试研究

目的　通过原位聚合法制备新型的聚乳酸与纳米羟基磷灰石复合材料,找到两者复合的最佳配比,从而得到理想的人工骨移植材料。 方法　采用原位聚合法按一定的配比（纳米羟基磷灰石质量分数分别为0,10%,20%,30%,40%)聚乳酸与纳米羟基磷灰石复合人工骨,对这类新型的人工骨进行性能测试,通过抗弯,抗压,弹性模量,电镜扫描,体外降解实验,观测该人工骨的力学性能、微观结构、纳米羟基磷灰石在聚乳酸中的分散情况以及复合材料的降解性能。 结果　（1）力学测试显示：随着n-HA含量的增加,复合材料的拉伸强度逐渐减少。复合材料的弯曲强度在n-HA微粒的质量分数为20%时弯曲强度出现峰值(156.8 MPa)。复合材料的弯曲模量随着n-HA微粒质量分数的增加而增大。（2）SEM扫描显示：纯PDLLA材料断裂表面较平整;在n-HA含量为10%时出现大量的韧窝, 明显的粗糙断裂面;在n-HA含量为20%断裂表面凹凸不平,形成大量的韧窝;在n-HA含量为30%以上时断口又变得越来越平整,尚有许多小的韧窝。（3）体外降解实验显示：随着降解时间的延长,降解液的pH值均逐渐降低,复合材料的力学性能也逐渐的产生一定的衰减。 结论　当n-HA含量为20%时,该人工骨复合材料有着更好的力学性能和降解性能,筛选出该种新型人工骨的最佳配比,制备出性能良好的PDLLA/n-HA复合人工骨材料。     

纳米羟基磷灰石/硫酸钙复合人工骨的生物安全性研究

目的研制纳米羟基磷灰石/半水硫酸钙(n-HA/CSH)复合型人工骨,并对其进行体内、外生物安全性测试。方法对n-HA/CSH人工骨进行急性全身毒性试验、皮内刺激试验、致敏试验、MTT细胞毒性试验和遗传毒性实验(Ames试验)并与对照组比较。结果人工骨浸取液静脉及腹腔注射后不引起小鼠呼吸、进食改变或死亡,体重稳定。家兔皮内注射72小时后仅出现红斑或微弱水肿,豚鼠皮内注射后未出现过敏反应。MTT细胞毒性试验显示含HA10%、20%、40%人工骨及纯n-HA、CSH的细胞增殖率均在77%以上,细胞毒性均为0～1级,Ames试验表明含HA40%人工骨的不同浓度生理盐水浸取液引起鼠伤寒沙门氏菌回复突变数均不超过阴性对照组的2倍。结论n-HA/CSH复合材料不引起全身毒性反应、皮内刺激反应和急性过敏反应。且无MTT细胞毒性,细胞相容性良好。同时,复合材料的生理盐水浸取液不引起鼠伤寒沙门氏菌回复突变数增加。     

硫酸钙/纳米羟基磷灰石构建人工骨材料的实验研究

目的探索将纳米羟基磷灰石（n-HA）/硫酸钙与半水硫酸钙（2CaSO4·H2O,CSH）组合构建一种新型的人工骨材料,研究其降解速度、理化特性及物质的变化过程,并对该变化与构建人工骨材料的成骨活性的相互作用及关系进行分析。方法模拟人体体液SBF9#浸泡液,将5组样品进行浸泡测试;5组分别是：n-HA、CSH、CSH/10wt%HA、CSH/20wt%HA和CSH/40wt%HA,测定钙磷元素释放速率、失重率及CSH/HA变化并对复合人工骨材料表面形态作扫描电镜观察和XRD分析。结果体外浸泡后,n-HA在24h内质量失重50%,24h后基本稳定;CSH外形及失重变化稳定,但2周后仅剩余少量,到17天时完全降解;3组复合材料质量失重及外形变化不大。5组在浸泡后24h内均有Ca释放,但n-HA组的Ca释放低于其他4组,各组均有P元素释出,但随时间逐渐减少。XRD结果分析：复合人工骨材料浸泡中的峰值下降,HA峰值强度增高。电镜观察到浸泡后复合材料形成新的晶体形态。结论本研究将硫酸钙、纳米羟基磷灰石2种材料复合,其主要成分存在相互作用,在模拟人体体液浸泡的环境下出现表面Ca、P元素的释放-吸附动态过程并新生磷灰石层,材料的降解速度可通过调节成分配比而加以控制。     

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.     

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.     

What will studies of Fulani individuals naturally exposed to malaria teach us about protective immunity to malaria?

There are an estimated over 200 million yearly cases of malaria worldwide. Despite concerted international effort to combat the disease, it still causes approximately half a million deaths every year, the majority of which are young children with Plasmodium falciparum infection in sub-Saharan Africa. Successes are largely attributed to malaria prevention strategies, such as insecticide-treated mosquito nets and indoor spraying, as well as improved access to existing treatments. One important hurdle to new approaches for the treatment and prevention of malaria is our limited understanding of the biology of Plasmodium infection and its complex interaction with the immune system of its human host. Therefore, the elimination of malaria in Africa not only relies on existing tools to reduce malaria burden, but also requires fundamental research to develop innovative approaches. Here, we summarize our discoveries from investigations of ethnic groups of West Africa who have different susceptibility to malaria.     

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.     

Class II HLA in Georgia Caucasus Tbilisi Georgians and their Mediterranean ancestry: The Usko Mediterranean languages

Georgia (or Sakartvelo in its own language) is a South Caucasus Mts. country with its easternmost part is enigmatically named Iberia, like the Iberian Peninsula, which may refer to rivers “Kura” and “Ebro” or their valleys respectively. Most of their inhabitants speak Georgian which is included within Dene-Caucasian group and Usko-Mediterranean subgroup of languages. The latter includes Basque, Berber, ancient Iberian-Tartessian, Etruscan, Hittite, Minoan Lineal A and others. In the present paper, HLA class II -DRB1 and -DQB1 alleles has been studied and extended haplotypes calculated. Most frequent haplotypes are also of Mediterranean origin (i. e.: (A*02-B*51)-DRB1*11:01-DQB1*03:01, (A*02-B*51)-DRB1*13:01-DQB1*06:03, or (A*24-B*35)-DRB1*01:01-DQB1*05:01) and DA genetic distances show that closest world populations to Georgians are Mediterraneans. Georgians also show common extended haplotypes ((A*02-B*51)-DRB1*11:01-DQB1*03:01, (A*02-B*13)-DRB1*07:01-DQB1*02:01 and (A*03-B*35)-DRB1*11:01-DQB1*03:01) with Svan people, a secluded population in North Georgia mountains. We can conclude that Georgians belong to a very old Mediterranean substratum according to both linguistics (Usko Mediterranean languages) and HLA genetics.     

'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.