壳聚糖结构和分子量对凝血作用的研究

本工作研究了不同脱乙酰度和不同分子量壳聚糖、壳聚糖醋酸生理盐水溶液及羧甲基壳聚糖生理盐水溶液的凝血作用。在壳聚糖醋酸生理盐水溶液作用下，红细胞发生聚集和形变，而且低脱乙酰度现象明显，分子量在10^5～10^6范围内影响不十分明显；羧甲基壳聚糖不能使红细胞在低相对离心力下发生沉降，仅有部分叠连现象；而壳聚糖则不能使红细胞发生聚集和形变。血液凝血酶时间(TT)、凝血酶原时间(PT)、活化部分促凝血酶原激酶时间(APTT)和纤维蛋白原浓度(FIB)验证了壳聚糖、壳聚糖醋酸生理盐水溶液以及羧甲基壳聚糖均不激活凝血因子，且脱乙酰度、分子量以及取代基对这些指标也没有明显地影响。动态凝血实验发现低脱乙酰度壳聚糖能够更好地使血液凝固。     

壳聚糖醋酸溶液对凝血作用的研究

研究了不同脱乙酰度和不同分子量壳聚糖醋酸溶液的凝血作用。发现壳聚糖醋酸溶液使抗凝血液中红细胞发生了明显的聚集和变形。通过不同分子量和脱乙酰度壳聚糖的促红细胞聚集实验,证明了低脱乙酰度壳聚糖(60%~70%)使红细胞聚集效果更好,分子量在105~106范围内作用不十分明显。对血液的凝血酶时间(TT)、凝血酶原时间(PT)、活化部分促凝血酶原激酶时间(APTT)和纤维蛋白原浓度(FIB)的测定结果验证了壳聚糖醋酸溶液凝血机理不依赖于血小板和常规“瀑布”凝血机制。     

不同分子量壳聚糖膜性质的研究

分别以分子量为130，000、220，000、300，000、550，000道尔顿的壳聚糖制备壳聚糖膜，并研究了各膜的表面结构、结晶性、力学特性、渗透性、透光透气性、吸附性、生物降解性等。结晶表明壳聚糖膜的各种特性和壳聚糖的分子量相关，高分子量的壳聚糖膜表面较为光滑，透光性较好，透气性、渗透性和生物降解性较差；低分子量的壳聚糖膜表面较为粗糙，透气性、渗透性和生物降解性较好，但透光性较差。经分析认为膜的结晶性和超微结构决定了不同分子量壳聚糖膜具有不同的性质。     

壳聚糖相对分子量对壳聚糖膜与角膜基质细胞相容性的影响

以脱乙酰度为95％，相对分子量分别为130KDa、220KDa、300KDa和500KDa的壳聚糖制备不同的壳聚糖膜。以各种壳聚糖膜作为基质，体外培养兔角膜基质细胞，通过观察角膜基质细胞在不同壳聚糖膜上的生长状态、贴附情况、生长曲线以及乳酸脱氢酶的活性，研究壳聚糖相对分子量对壳聚糖膜与角膜基质细胞生物相容性的影响。实验结果表明壳聚糖相对分子量对壳聚糖膜与角膜基质细胞的相容性具有重要的影响，相对分子量过高或过低的情况下，壳聚糖膜与角膜基质细胞相容性较差，对细胞损伤程度较大，细胞在膜上的贴附、生长能力较差；以相对分子量在200KDa～300KDa之间的壳聚糖制备出的膜与角膜细胞具有较好的相容性，细胞可在膜上长成密集单层，适合作为角膜培养的支架材料。     

影响水溶性羧甲基壳聚糖稳定性的外界因素

以虾壳为原料,制备了水溶性羧甲基壳聚糖。通过对壳聚糖特性黏度的测定来表征其稳定性,具体研究了影响壳聚糖稳定性的因素温度、pH值、离子强度、紫外线和灭菌过程。结果表明溶液的酸碱度和离子强度对壳聚糖的特性黏度有很大的影响,在一定范围内,壳聚糖溶液的黏度随之变化敏感。紫外线照射和灭菌过程不但使特性黏度降低,更使壳聚糖的分子结构发生显著变化。特性黏度随时间而降低,在37℃时降低较快,在2℃～8℃冷藏条件下壳聚糖制品可保持一定的稳定性,为壳聚糖的存放条件提供了科学依据。     

不同分子量羧甲基壳聚糖的制备及其对皮肤成纤维细胞和角质形成细胞生长的影响

本实验将高分子量壳聚糖通过酸水解法和氧化法降解成不同分子量,然后将其羧甲基化制备成相应不同分子量的羧甲基壳聚糖。分别以bFGF和EGF为对照,通过显微观察法和MTT细胞计数法研究不同分子量的羧甲基壳聚糖对小鼠皮肤成纤维细胞和人皮肤表皮角质形成细胞形态及细胞生长的影响。实验结果表明:不同分子量的羧甲基壳聚糖在浓度为1～1 000 ppm时对成纤维细胞和表皮角质形成细胞生长均有促进作用,在浓度为100 ppm时促进作用最强;其促进作用随着分子量的减小而增强,分子量为3 KD左右的羧甲基壳聚糖对成纤维细胞和表皮角质形成细胞生长促进作用最为显著,分别与bFGF和EGF促生长作用基本相当。     

壳聚糖水凝胶的研制及其与C2C12细胞粘附、支持作用的实验研究

研制可注射的壳聚糖水凝胶材料,并对该材料的理化特性进行检测,同时检验其是否能粘附并支持C2C12细胞生长。对不同温度下的壳聚糖溶液进行pH值的测定,并以壳聚糖溶液和β-甘油磷酸钠溶液为原料,制备温敏性壳聚糖水凝胶,对该材料的粘度及37℃成胶时间进行测定,显微镜下观察水凝胶材料的结构,通过C2C12细胞在其表面上的粘附与生长情况,判定该材料是否具有良好的细胞相容性。结果表明：该材料具有温度敏感性,即室温下为液态,37℃变为固态。当壳聚糖溶液浓度为2%时,加入45%β-甘油磷酸钠溶液后的成胶作用时间最短,约为15min。C2C12细胞在壳聚糖水凝胶材料上的粘附与生长情况良好。壳聚糖水凝胶可作为可注射性组织工程化心肌的支架材料,用于携带有效细胞进行缺血性心脏病的治疗。     

壳聚糖对幽门螺杆菌外膜屏障功能的影响

研究壳聚糖 (即脱乙酰壳聚糖 ,Chi tosan)对Hp外膜屏障功能的影响 ,以探讨壳聚糖抗Hp的作用机制 ,以 6种抑菌作用较好的壳聚糖溶液 ,3种 70 %脱乙酰、3种 88.5 %脱乙酰为试验材料。将Hp标准菌株SydneyStrain 1(SS1)、NCTC116 39、NCTC116 37加入上述壳聚糖溶液中 ,细菌浓度为 10 8CFU ml,将每种壳聚糖分别与Hp菌液加入 2 4孔加样板中 ,每孔 2ml,每种溶液做 5孔 ,在 37℃和微需氧条件下 ,12 0r min振荡 ,4 8h后取出孔内液 ,30 0 0r min离心 10min后 ,取上清液分别测葡萄糖含量、天门冬氨酸氨基转移酶 (AST)和γ 谷氨酰转肽酶(GGT)…     

不同脱乙酰度对壳聚糖膜与角膜基质细胞相容性的影响

以分子量为30万．脱乙酰度分别为63．3％、73．7％、83％和97％的壳聚糖制备不同的壳聚糖膜，在不同脱乙酰度的壳聚糖膜上培养兔角膜基质细胞．通过观察角膜基质细胞在不同壳聚糖膜上的生长状态、贴附情况、生长曲线以及乳酸脱氢酶的活性，研究壳聚糖分子脱乙酰度对壳聚糖膜与角膜基质细胞生物相容性的影响。实验结果表明壳聚糖脱乙酰度越高。壳聚糖膜对细胞的损伤越小。越有利于细胞在膜上的生长和贴附，反之．低脱乙酰度的壳聚糖膜与角膜细胞的相容性较差。     

真菌发酵制备生物材料壳聚糖

利用犁头霉属真菌发酵生产壳聚糖。发现培养温度、时间以及 p H值等因素对壳聚糖产量及性质产生明显影响。p H值影响壳聚糖的脱乙酰程度 ,p H值控制在 4 .5可获得 90 %以上的脱乙酰度 ;2 8～2 9℃和 p H值 5.0条件下 ,壳聚糖的收率达到 780 mg/ L ;随培养时间延长 ,产品分子量迅速下降。扫描电镜分析显示 ,发酵法生产的壳聚糖成膜后 ,与酸碱处理甲壳素得到的产品在微观结构上存在显著差别     

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 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.     

Der Einfluß von Nahrungsmitteln und Rauchen auf die klinisch-chemische Diagnostik von Phäochromozytom,Neuroblastom und Karzinoid-Syndrom

Zusammenfassung Der Einfluß von verschiedenen Nahrungsmitteln auf Methoden zur Bestimmung von Adrenalin (AD), Noradrenalin (NA), Vanillinmandelsäure (VMS), Metanephrinen (MN), Homovanillinsäure (HVS) und 5-Hydroxyindolessigsäure (5-HIE) im 24 h-Harn zur Diagnose des Phäochromozytoms bzw. Karzinoid-Syndroms wurde untersucht. Die in die Untersuchung einbezogenen Nahrungsmittel waren: Tee, Kaffee, Mandeln, Ananas, Käse, Walnüsse, Vanillepudding, Bananen, Tomaten und Milchschokolade. Außerdem wurde der Einfluß des Zigarettenrauchens auf die Bestimmung von AD, NA, VMS und MN untersucht.Walnüsse führten zu einer starken Erhöhung der 5-HIE-Ausscheidung. Bananen erhöhten die Ausscheidung von AD, NA, VMS, MN und 5-HIE. Kaffee und Ananas bewirkten eine geringe Zunahme der MN-Werte. Rauchen von 20–30 Zigaretten/Tag beeinflußte keine der vier Variablen.Wenn die beschriebenen Methoden benutzt werden, sollte lediglich auf den Verzehr von Bananen und Walnüssen vor und während der Harnsammelperioden verzichtet werden, da die oberen Normgrenzen im Harn überschritten werden könnten. Ein Verzicht auf Kaffee und Ananas in normalen Mengen ist nicht erforderlich. Es besteht kein Anlaß, weiterhin die bisherigen umfangreichen Restriktionen der übrigen Nahrungsmittel beizubehalten.