氧等离子体表面改性P3/4HB无纺支架

研究氧等离子体表面改性对P3/4HB无纺支架的作用。氧等离子体改性P3/4HB无纺支架,改性的效能通过检测接触角及X射线光电子能谱分析进行结构表征,接种大鼠肌成纤维细胞,检测细胞黏附率以进行功能表征,并检测改性前后的最大应力变化。结果表明:等离子体改性后的P3/4HB无纺支架表面氧含量增加了12.1%,C-O(C-OH)峰、COOR(COOH)峰分别增加了0.2%、6.2%,接触角下降了44°,而最大应力无明显变化,改性后支架细胞黏附率较预处理组高。说明氧等离子体处理P3/4HB支架,可引入功能性的-OH、-COOH等活性基团,改善材料的表面亲水性,提高对细胞的黏附力,为进一步共价接枝生物活性单体创造了条件。     

氧等离子处理人工晶状体材料的生物相容性

背景：氧等离子处理可有效改善双组分室温硫化硅橡胶人工晶状体材料表面的亲水性能和生物相容性,但等离子体聚合形成的薄膜可能产生卷曲和破裂或因与基质是非共价键结合而产生剥离,影响材料本身的理化性能和光学性能。 目的：初步评价优选氧等离子处理表面改性后双组分室温硫化硅橡胶人工晶状体材料的体外生物相容性。 方法：采用氧等离子体表面改性技术修饰疏水性双组分室温硫化硅橡胶人工晶状体材料的表面,处理功率及时间分别为：20 W、50 W、100 W和30 s、1 min、3 min、10 min。应用视频光学接触角测定仪、傅里叶变换衰减全反射红外光谱和X射线光电子能谱分析材料表面亲水性和表面化学元素组成;扫描电子显微镜和原子力显微镜观察材料表面形貌。通过人晶状体上皮细胞黏附实验观察双组分室温硫化硅橡胶表面改性前后细胞的数量及形态改变。 结果与结论：最佳改性条件为100 W,30 s,20 mL/min,40 Pa。此条件改善了双组分室温硫化硅橡胶人工晶状体材料表面的亲水性,对材料表面无刻蚀作用,改善了人晶体上皮细胞在双组分室温硫化硅橡胶人工晶状体材料表面的生物相容性。     

乳酸／羟基乙酸共聚物-壳聚糖膜支架的制备及体外性质研究

目的制备乳酸,羟基乙酸共聚物（PLGA）-壳聚糖（CS）接枝化合物．改善PLGA薄膜的亲水性。方法利用PLGA端基的羧基与CS进行反应,从而在PLGA长链上共价键合CS。通过傅立叶变换红外光谱（FTIR）、差示扫描热分析法（DSC）、热重分析法（TGA）、X射线光电子能谱法（XPS）对其结构和热力学性质进行表征,利用接触角评价PLGA—CS薄膜表面亲水性能。结果通过共价结合的方式制备了CS改性PLGA化合物．该接枝化合物热稳定性和亲水性能都较PLGA有了明显提高。结论成功制备了不同接枝比例的CS改性PLGA化合物．该薄膜的亲水性能得到了较大的改善．拓展了该类型材料在生物医学工程领域的廊用范围．     

医用聚碳酸酯的涂层修饰及生物相容性研究

目的 研制低分子肝素钠(LMWH)涂层和多醛基氧化海藻酸钠(OSA)涂层的聚碳酸酯,并对其生物相容性进行评价.方法 利用化学接枝改性方法制备涂层材料,进行表征并验证涂层稳定性;通过接触角测定、体外血清蛋白、血小板黏附试验、体外凝血试验等进行生物相容性评价.结果 分析红外光谱,发现涂层后材料出现与涂层物相关的吸收峰变化,定量结果显示材料表面涂层量稳定.与未涂层材料相比,涂层材料表面与水的接触角减小,血清蛋白、血小板黏附量显著减少,凝血酶原时间(PT)和活化部分凝血活酶时间(APTT)显著延长,其差异有统计学意义(P＜0.05).与LMWH涂层材料相比,OSA涂层材料抗凝效果略差,但其蛋白黏附量、表面接触角小于LMWH涂层,差异具有统计学意义(P＜0.05).结论 应用化学接枝改性方法制备LMWH、OSA涂层的聚碳酸酯,其涂层稳定,生物相容性显著改善.     

生物医学材料 聚氨酯表面接枝左旋——丙交酯以改善细胞粘附性

聚氨酯具有良好的生物相容性和力学性能 ,在心血管材料及其它生物医用材料领域得到广泛应用 ,但其表面的细胞粘附性较差 ,本文研究了运用等离子体引发表面接枝方法改善聚氨酯表面的细胞粘附性。市售聚氨酯溶于四氢呋喃铸成膜 ,用氩等离子体处理后在空气中放置一定时间 ,浸入溶有左旋丙交酯的甲苯中 ,脱气封管在 70℃反应 5h,得到表面接枝左旋丙交酯的 PU膜。接触角测量显示等离子体处理后水接触角由 73°下降到 36°,接枝使接触角略有上升 ,但仍比未处理聚氨酯及聚左旋乳酸表面亲水性好。只用等离子体处理而未进行表面接枝的聚氨酯膜接触角…     

生物材料改性对人涎腺细胞生长的影响

目的：利用SO2等离子体对聚乳酸和聚醚酯膜进行表面改性，研究人类涎腺细胞系HSG细胞在生物材料上的生长。方法：材料的表面性质通过表面接触角和X射线光电子能谱(XPS)进行表征。细胞形态与生长情况则通过倒置显微镜观察和MTT检测来评估。结果：用SO2等离子体改性后，膜表面接枝上磺酸基团。亲水性明显增强；在几种材料中。用S02等离子体改性后的聚醚酯膜更适合HSG细胞的粘附生长。结论：用SO2等离子体改性后的聚醚酯材料可能用于人造涎腺的支架材料。     

聚乙二醇在聚砜膜上的接枝与表征

对用紫外辐照法在聚砜膜表面接枝的聚乙二醇作了初步的研究。通过静态水接触角测定、X射线-光电子能谱分析以及原子力学显微镜等测试手段，对接枝前后聚砜膜表面的性能进行了测定，证明采用同步接枝法和二步接枝法在聚砜材料表面接上了聚乙二醇，表面亲水性大大提高，两种接枝方法的接枝覆盖率分别为77．3％和41．9％，表面形貌、相位图等参数较接枝前变化明显，说明用同步法在聚砜膜表面产生了分枝的聚乙二醇层，而二步法在聚砜膜表面产生了薄煎饼状的聚乙二醇层。这一研究为下一步拟在聚砜中空纤维膜表面接上聚乙二醇刷分子层打下了基础。     

基于肝素和硫酸软骨素的两种纳米颗粒改性表面对生物相容性影响的研究

本研究合成了基于肝素和硫酸软骨素的两种纳米颗粒,用于316L不锈钢表面的生物功能改性。通过激光粒度分析仪、傅立叶变换红外光谱(FTIR)、原子力显微镜(AFM)、水接触角等对纳米颗粒的性质及颗粒固定前后表面的理化性质进行表征。通过体外血液相容性评价和内皮细胞相容性评价对两种纳米颗粒改性表面的生物相容性进行对比研究。结果表明,两种纳米颗粒均能有效降低材料表面血小板的粘附和聚集行为,但肝素纳米颗粒对内皮细胞的生长增殖表现出抑制作用,而硫酸软骨素纳米颗粒改性表面则具有促进内皮再生的潜能。     

聚醚醚酮表面多孔羟基化改性对MC3T3-E1细胞黏附、增殖的影响

目的对聚醚醚酮(polyetheretherketone,PEEK)薄片表面进行多孔化和羟基化改性,观察PEEK表面形貌和生物活性的变化,并探讨该改性方法对前成骨MC3T3-E1细胞黏附、增殖的影响。方法超声波环境下浓硫酸处理PEEK表面,在其表面形成大量微孔结构;经湿化学法将PEEK表面的酮类基团还原成羟基基团,改善其表面化学活性,提升PEEK薄片的生物相容性。利用扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FTIR)及静态水接触角检测改性前后材料表面形貌、化学基团及亲水性的变化。未处理PEEK、多孔化PEEK、羟基化PEEK、多孔羟基化PEEK与MC3T3-E1细胞共培养,评价表面改性后PEEK薄片对细胞黏附、增殖的影响。结果 SEM结果显示浓硫酸处理后的PEEK薄片表面形成密集的空隙大小均匀的微孔结构,FT-IR结果证实羟基化改性成功地在PEEK表面还原出了大量羟基基团。同时,表面多孔化和羟基化改性均可有效提升PEEK材料表面的亲水性能。在体外细胞实验中,不同改性的PEEK材料与MC3T3-E1细胞共培养后结果显示,多孔化、羟基化和多孔羟基化改性均可显著促进细胞黏附和伸展,同时随着时间的延长,其促进细胞增殖的功能也逐步增强。结论表面多孔羟基化改性能有效提高PEEK材料表面的生物学活性和亲水性能,进而显著促进细胞的黏附和增殖。     

利用等离子体表面接枝技术提高医用聚氨酯血液相容性的研究

目的：聚氨酯作为与血液接触的植入物和组织器官替代材料在心血管系统有重要而广泛的应用前景,本研究采用等离子体表面接枝技术,通过“空间桥梁”在聚氨酯材料表面引入具有抗凝血功能的肝素分子,对材料表面的微观化学组成、表面接触角等理化性能进行了测定分析,并通过测定血小板在材料表面的粘附数量,对改性表面的抗凝血性能做了评价。结果：聚氨酯表面接枝肝素分子后,表面的氧／氮元素比提高,水接触角减小。对血小板的吸附和活化性下降,抗凝血性能得到提高。     

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.     

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.     

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.     

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.