胰岛移植用免疫隔离微胶囊的牢固度、生物相容性和通透性研究

目的为了探讨用于胰岛移植的海藻酸钠-聚赖氨酸-海藻酸钠（APA）生物膜的免疫隔离效果。方法采用高压静电成囊装置,制备APA微胶囊和微囊化胰岛,微囊直径为0.25～0.55mm;取空微囊,利用恒温振荡仪振荡后测定其破损率;将空微囊移植至小鼠腹腔,分别于不同时间由腹腔中灌洗出微胶囊,记数并观察其形态;取一定量空微囊分别与IgG、BSA和胰蛋白酶孵育,测量其浓度变化确定APA微胶囊的通透性。结果采用高压静电成囊技术制成的APA微胶囊呈球形,大小均匀、表面光滑,具有较好的生物相容性;粒径为0.25～0.35mm的微胶囊其牢固度大于粒径为0.45～0.55mm的微胶囊;葡萄糖、胰岛素等小分子物质能够自由通过微囊膜,胰蛋白酶也可通过,但速度较慢;大分子物质牛血清白蛋白和免疫球蛋白则不能透入APA微囊。结论采用高压静电成囊技术可制备高质量粒径为0.25～0.35mm的微胶囊;这是具有良好免疫隔离性能的APA微胶囊。     

胰岛素移植用免疫隔离微胶囊的牢固度、生物相容性和通透性研究

目的：为了探讨用于胰岛移植的海东酸钠－聚赖氨酸－海藻酸钠（APA）生物膜的免疫隔离效果,方法：采用高压静电成囊装置,制备APA,微胶囊和微囊化胰岛,微囊直径为0．25－0．55mm,取空微囊,利用恒温振荡仪振荡后侧定其破损率,将空微囊称植至小鼠腹腔,分别于不同时间由腹腔中灌洗出微胶囊,记数并观察其形态,取一定量空微囊分别与ＩgG,BSA和胰蛋白酶孵育,测量其浓度变化确定ＡＰＡ向表囊的通透性,结果：采用高压静电成囊技术制成的ＡＰＡ微胶囊呈球形,大小均匀、表面光滑,测量较好的生物相容性,粒径为０．２５－０．３５mm 的微胶囊其牢固度大于粒径为０．４５－０．５５mm的微胶囊,葡萄糖,胰岛素等小分子物质能够自由通过微囊膜,胰蛋白酶也可通过,但速度较慢,大分子物质牛血清白蛋白和免疫球蛋白则不能透人ＡＰＡ微囊 ,结论：采用高压静电成囊技术可制备高质量粒为０．２５－０．３５mm的微胶囊,这是具有良好免疫隔离性能的ＡＰＡ微胶囊。     

移植用微囊化细胞低温保存的研究

目的：探索移植用微囊化细胞低温保存的可行性。方法：以海藻酸钠-聚赖氨酸-海藻酸钠微胶囊（APA微胶囊）为研究体系，以转内皮抑素重组中国仓鼠卵巢细胞（rCHO）为模型细胞，观察低温保存过程中降温方式、预平衡方式、冷冻保护剂浓度等关键条件对微囊化细胞复苏活性的影响，以及低温保存后微囊膜对IgG的通透性及微囊内细胞的存活、增殖及产物分泌情况。结果：包埋功能细胞的APA微囊经一定时间的低温保存后，微囊膜仍可屏蔽IgG，并未改变其原有的免疫隔离特性，且囊内细胞具有较高的细胞活性，能够正常生存并保持增殖和产物分泌能力。结论：微囊化细胞进行低温保存是可行的。     

一种新型的生物人工肝—微囊肝细胞

采用海藻酸盐—聚赖氨酸—海藻酸盐膜成功地将大鼠游离肝细胞制备成微囊肝细胞。短期体外培养显示微囊肝细胞的尿素和白蛋白合成功能与游离肝细胞相仿。组织学检查显示植入大鼠腹腔内的微囊肝细胞35天后仍有半数存活。将微囊肝细胞植入氨基半乳糖引起肝衰竭的大鼠腹腔内可显著地提高其存活率,初步研究的结果表明微囊肝细胞可能有治疗肝衰竭的临床应用价值。     

微囊对大鼠松果体细胞作用的实验研究

目的　探讨微囊化处理后大鼠松果体细胞 5羟色胺 N 乙酰转移酶 (NAT)mRNA的表达及细胞微囊的免疫原性 ,进一步明确人工松果体组织的功能活性与免疫屏蔽效能。　方法　海藻酸钠 聚赖氨酸 海藻酸钠生物微胶囊 (APA微囊 )包裹大鼠松果体细胞 ,采用RT PCR技术检测微囊与对照组松果体细胞的NATmRNA表达 ;运用3H标记胸腺嘧啶核苷 (3H TdR)掺入法比较微囊组、空囊组及游离松果体细胞的淋巴细胞转化值。　结果　不同培养时间对照组和微囊组松果体细胞的NATmRNA表达水平无显著差异 ;微囊组淋巴细胞转化值明显低于游离的松果体细胞 (P <0 0 1) ,但仍高于空囊组 (P <0 0 5 )。　结论　微囊包裹不影响松果体细胞NATmRNA的表达 ,表明APA微囊内松果体细胞代谢正常 ,分泌功能旺盛 ;松果体微囊有一定的免疫保护效应 ,但其隔离作用仍不完全。     

海藻酸钠-壳聚糖微胶囊载体在组织工程研究中的应用

背景：用壳聚糖包裹海藻酸钠制备微囊,可以改善海藻酸钠水凝胶的力学性能,如何获得理想的海藻酸钠壳聚糖微囊以及该微囊体系的应用前景是这一研究的关键。 目的：探讨海藻酸钠壳聚糖微胶囊载体的制备方法、成型机制,分析影响微胶囊膜强度性能的几个重要因素及探讨海藻酸钠-壳聚糖微胶囊在固定化细胞技术、药物载体和组织工程方面的应用前景。 方法：由第一作者采用计算机检索PubMed数据库、Elsevier ScienceDirect、中国知网库、万方数据库1987至2013年有关海藻酸钠壳聚糖微囊制备方法、反应机制及应用前景的文章。 结果与结论：海藻酸盐水凝胶在药物释放和组织工程领域具有很多优势,但是凝胶溶蚀现象和力学性能缺陷限制了它的应用,壳聚糖与海藻酸钠通过静电相互作用形成聚电解质络合物,弥补了海藻酸钠凝胶的不足。通过控制壳聚糖溶液的性质-壳聚糖的分子质量、壳聚糖溶液的pH值和浓度制备膜强度高的微囊,海藻酸钠-壳聚糖微囊在固定化技术、药物释放和组织工程领域表现出了广阔的应用前景。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：     

APA微囊移植免疫隔离效果的研究

目的：探讨海藻酸钠-多聚赖氨酸-海藻酸钠(APA)微囊在宿主体内的免疫隔离作用。方法：分别将APA空微囊、牛嗜铬细胞(BCCs)和APA微囊化BCCs(APA-BCCs)移植到绵羊的蛛网膜下腔中，观察宿主细胞免疫指标和组织形态学的变化。结果：各组移植后血中淋巴细胞数量无明显变化；APA微囊包裹可明显阻止BCCs移植引起的血中CD4^ T淋巴细胞比例、CD4^ ／CD8^ 值和脑脊液中淋巴细胞数量的增加；APA微囊包裹可减轻羊移植区组织反应，延长移植物的存活。结论：APA微囊具有免疫隔离效果，可有效地阻止细胞免疫排斥反应。     

静电法制备小微囊包裹成年猪胰岛的实验研究

目的探索用静电法制备小微囊包裹成年猪胰岛细胞.方法用自制的静电微囊发生装置、制备海藻酸钠-多聚赖氨酸-海藻酸钠(APA)微囊(微囊直径<350μm),包裹成年猪胰岛,体外检测APA小微囊猪胰岛生物活性及微囊膜的通透性.结果静电法制备的APA微囊直径300～350μm,大小相对均一.小微囊包裹成年猪胰岛后,每个微囊内可见1～2个胰岛团,表面光滑.囊内胰岛组织学结构完整,体外培养微囊化胰岛素分泌良好,葡萄糖刺激释放明显,显示了良好的细胞活力及微囊膜通透性.结论用我们自制的静电微囊发生装置能制备APA微囊包裹成年猪胰岛细胞,微囊直径300～350μm,表面光滑,囊内猪胰岛生物活性良好.     

APA微囊牛肾上腺嗜铬细胞治疗疼痛的量效时效关系研究

研究海藻酸钠-聚赖氨酸-海藻酸钠(APA)微囊牛肾上腺嗜铬细胞(BCC)治疗大鼠疼痛动物模型的量效时效关系。用结扎坐骨神经制作大鼠疼痛动物模型,将APA微囊BCC移植到动物模型的蛛网膜下腔,分别用冷致痛实验和热过敏实验观察镇痛效果。结果显示与对照组相比,细胞数量5万组、10万组和20万组收缩差异均减小(P<0.05),且随细胞量增加差异减小,表明有明显镇痛作用;40万组与20万组相比没有明显差异。这种镇痛作用可持续12周以上。以上结果表明APA微囊BCC治疗大鼠疼痛动物模型的移植细胞数量和镇痛效果呈正相关关系,有效镇痛时间在12周以上。     

APA微囊细胞移植的免疫隔离作用

随着器官移植研究的深入,诸如移植物排斥反应、供体缺乏等一系列问题出现在人们面前。1980年,Lim等[1]首次采用微囊免疫隔离技术进行胰岛微囊化移植研究,为人类解决这些问题提供了新思路。微囊化免疫隔离技术近些年取得了众多成就,目前研究表明由海藻酸钠—多聚赖氨酸—海藻酸钠(APA)构成的微胶囊具有制作简便、体积小、生物相容性好等优点,是应用前景较好的免疫隔离膜[2]。本文将就其免疫隔离效果的研究进展作如下综述。1发展史60年代Chang[3]首次提出人工细胞的概念,即用具有生物相容性的半透膜包裹组织细胞,该膜允许小分子营养物、代谢…     

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.     

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.     

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.     

'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.