嗅鞘细胞移植和左旋硝基精氨酸对大鼠脊髓损伤后背核神经元存活及其轴突再生的影响

目的 探讨嗅鞘细胞(OECs)移植和一氧化氮合酶(NOS)抑制剂左旋硝基精氨酸(LNNA)对大鼠脊髓损伤后,背核神经元存活及其轴突再生的影响.方法 将20只大鼠行脊髓半横断术后分为对照组、OECs组、L-NNA组和OECs L-NNA组.OECs L-NNA组在脊髓损伤处移植嗅鞘细胞,并注射L-NNA.术后30d时,应用NADPH酶组织化学、免疫组织化学、中性红染色、HE染色和荧光金逆行标记等方法,观察4组大鼠L1背核神经元存活及其轴突再生情况.结果 1.0ECs组、L-NNA组L1背核神经元存活数量均高于对照组,且分类计数显示,这两组对脊髓背核大、中、小神经元的存活均有促进作用,而OECs L-NNA组的促存活作用最显著.2.0ECs组和OECs L-NNA组脊髓损伤处可见再生的轴突,且L1背核可观察到被荧光金逆行标记的神经元胞体.3.与对照组比较,OECs组L1背核NOS阳性神经元增加,L-NNA组NOS阳性神经元减少,OECs L-NNA组NOS阳性神经元数量差异不明显.结论 嗅鞘细胞移植和L-NNA均可促进脊髓受损伤背核神经元的存活,两者联合应用可更好地促进受损伤的背核神经元存活及其轴突再生.     

蛋白激酶C亚型在原代培养神经元生长中的作用

目的　探讨PKC不同亚型在原代培养脊髓神经元突起生长中的作用。　方法　采用免疫组织化学技术研究蛋白激酶C(PKC) 4种亚型 (α、βⅠ、βⅡ和ε)在胎鼠脊髓原代培养神经元突起生长过程中的表达与分布 ,借助计算机图像分析系统同步测定突起长度和胞体面积。　结果　原代培养神经元生长过程中 ,7d前随着PKC 4种亚型的表达逐渐增加 ,神经元胞体逐渐长大及突起逐渐延长 ;7d以后无论在胞体还是突起中 ,PKC 4种亚型的表达均下降 ,突起开始萎缩 ,胞体内出现空泡。相关分析发现 βⅡ亚型与突起生长关系最密切 (r =0 73,P <0 0 1)。 　结论　PKC可能参与了神经元的生长过程 ;βⅡ型PKC在培养脊髓神经元突起生长中的作用较为重要     

神经营养素-3能够促进体外受损伤大鼠脊髓神经元的存活及其神经突起生长

目的探讨神经营养素-3(NT-3)对体外机械性损伤的大鼠脊髓神经元存活及其神经突起生长影响。方法将体外培养的大鼠脊髓神经元分为4组:正常组、对照组、20 ng/ml NT-3组和40 ng/ml NT-3组。培养4 d后,除正常组外,其余3组建立划痕损伤模型。在划痕损伤后,对照组不做处理,另外2组分别在培养液中加入20 ng/mlNT-3和40 ng/ml NT-3继续培养。直至培养第6 d,应用4%多聚甲醛固定4组细胞。固定后的细胞分别做转移酶介导的三磷酸脱氧鸟苷-生物素刻痕末端标记(TUNEL)、微管相关蛋白2(MAP2)和生长相关蛋白-43(GAP43)免疫荧光染色,检测划痕损伤的神经元凋亡及其神经突起生长情况。结果免疫荧光化学染色显示,与对照组相比,应用NT-3处理的2组可以显著降低划痕损伤后的脊髓神经元凋亡率,并促进其神经突起生长。尤其是40 ng/mlNT-3组的神经元凋亡率最低,其神经突起可穿过划痕损伤边界。结论 NT-3能够促进体外机械性损伤的大鼠脊髓神经元存活及其神经突起生长。     

施万细胞对植入大鼠脊髓损伤区内的神经干细胞存活和分化的影响

目的 探讨施万细胞对植入损伤脊髓内的神经干细胞的存活及其分化的影响。方法 分离和克隆新生大鼠海马组织的神经干细胞；同时获取坐骨神经和臂丛神经，从中分离和纯化施万细胞。在移植前先用核荧光(Hoechst33342)标记神经干细胞。实验组为神经干细胞和施万细胞联合移植入大鼠脊髓半横断处，对照组为单独神经干细胞移植。应用免疫组织化学和酶组织化学技术，在移植后7d、14d、21d和30d分别观察神经干细胞的存活和分化情况。结果 实验组的神经干细胞比对照组迁移的更远，分化为神经丝蛋白染色阳性神经元样细胞的数量比对照组的多，并且有较长的突起长出。在30d实验组中，移植的神经干细胞有部分呈乙酰胆碱酯酶(AchE)染色阳性。而在对照组中，移植区内仅有少数呈AchE染色弱阳性的神经干细胞。结论 在脊髓损伤处，施万细胞可促进移植的神经干细胞存活、迁移和向神经元样细胞分化；有些神经元样细胞能长出较长的突起，有些呈现乙酰胆碱酯酶活性。     

经改良的取材和差速贴壁法培养纯化嗅黏膜嗅鞘细胞

目的:采用经改良的取材和差速贴壁法培养纯化嗅黏膜嗅鞘细胞(OECs),以探求更加简单、高效的嗅黏膜OECs取材和培养纯化方法.方法:成年雄性SD大鼠6只,采用经改良的方法剥取嗅黏膜,然后用改良差速贴壁法培养纯化嗅黏膜OECs.倒置相差显微镜下观察细胞生长情况以及形态并照相,培养7 d、14 d细胞行NGFRp75免疫细胞化学染色鉴定,并根据免疫细胞化学染色结果计算细胞纯度.结果:体外培养的嗅黏膜OECs形态主要有扁圆形或油煎蛋形、梭形或双极、多突起形.嗅黏膜OECs NGFRp75免疫细胞化学染色阳性.培养7 d嗅黏膜OECs纯度为90%,培养14 d嗅黏膜OECs纯度为85%.嗅黏膜OECs最长可以存活35 d.结论:经改良的取材和差速贴壁法培养纯化嗅黏膜OECs具有简单、高效的优点,培养的嗅黏膜OECs的纯度完全可以达到细胞移植的要求.     

蛋白激酶C在培养神经元突起生长中的作用

为探讨蛋白激酶 C(protein kinase C,PKC)在神经再生中的作用 ,本研究在对培养神经元生长规律与 PKC活性作相关分析的基础上 ,观察 PKC活性改变对原代培养的脊髓前角神经元突起生长状态的影响。以 5 -氟尿嘧啶 (5 - Fu)抑制有丝分裂代替免疫淘汰法提高神经元的纯度进行胎鼠脊髓前角神经元的原代培养。取孕 14d左右的 SD大鼠 ,行无菌操作取出胎鼠 ,于脑干以下平面取出脊髓 ,经胰酶消化吸管吹打 ,过 2 0 0目钢网后 ,滤过液在 1m l 4%牛血清白蛋白中30 0 g离心 10 m in,沉淀经 L 15培养基溶解后 ,于 1m l 6 .8%Metrizamide中 5 0 0 g离…     

不同发育期鸡胚脊髓背角提取液的神经营养活性初探

为了探讨在发育过程中鸡胚脊髓背角提取液的神经营养活性作用 ,分别取 Hamburger3 0期和 40期鸡胚的脊髓背角组织制成条件培养液 ,以 Hanks平衡盐溶液代替背角提取液设置对照组。实验组分别培养了两时相的脊神经节及其神经元。培养48h时测量各组每个脊神经节神经元的神经突起平均长度及神经元存活数。结果 :两时相实验组的神经元存活数量均明显大于对照组 (P<0 .0 5 ) ;而神经突起长度仅 40期组者大于对照组 (P<0 .0 5 )。另外 ,40期组脊神经节神经元的神经突起长度及神经元存活数量也明显高于 3 0期者。提示 ,两时相脊髓背角内均存在某些初级感觉神经元诱向因子。但在不同的发育阶段脊髓背角的神经营养活性却有变化。     

成人、成年狗鼻腔嗅黏膜成鞘细胞的纯化、培养与鉴定

目的研究成人和成年狗嗅黏膜成鞘细胞（OECs）的分离与培养的方法,为探索在人体和大型动物模型的自体嗅黏膜OECs移植修复脊髓损伤奠定基础。方法采用差速贴壁方法分别从成人和成年比格狗的嗅黏膜分离出OECs,分别培养25d,在第6d、10d和25d进行形态学观察,最后进行OECs特异标记物NGFRp75的免疫细胞化学染色,鉴定成鞘细胞。结果原代培养的成人和成年狗嗅黏膜OECs在培养10d后明显增多,25d的OECs成熟,具有很长的突起,其形态多为双极和三极,NGFRp75的免疫组织化学染色呈阳性。本实验条件下,狗嗅黏膜OECs的生长状态比成人的好。而未进行差速贴壁的培养细胞则几乎均呈成纤维样细胞。结论差速贴壁的方法可以分离出较为纯化的成人、成年狗鼻腔嗅黏膜OECs。     

人胎脊髓内源性物质对脊髓中GABA神经元的营养作用

目的:从人胎脊髓提取液中寻找对脊髓GABA神经元有神经营养作用的成分。方法:用四月龄人胎制备脊髓提取液,加人体外培养的胎鼠脊髓细胞中,观察提取液对神经元活性、突起生长和分化的影响。结果:人胎脊髓中有提高GABA神经元活性的营养成分,并且小于10kD组分还可以诱导GABA神经元的分化,但是提取液对GABA神经元的突起生长没有影响。结论:实验结果揭示人胎脊髓中可能存在不止一种神经营养活性成分,对GABA神经元的活性和分化起营养作用。     

激活素A与NGF协同刺激鸡胚背根神经节神经突起生长

目的:探讨激活素A(Activin A)与神经生长因子(Nerve growth factor,NGF)共同刺激鸡胚背根神经节(DRG)神经突起生长作用。方法:采用8 d的鸡胚DRG原代培养法,通过Activin A与NGF联合刺激,观察DRG神经突起生长和DRG神经元存活情况。采用RT-PCR检测钙基因相关肽(CGRP)。结果:Activin A与NGF体外联合培养3 d时DRG神经突起生长比单纯NGF组更明显,DRG神经元存活数量也明显增加,Activin A与NGF联合作用可以明显促进CGRP mRNA表达。结论:Activin A对NGF诱导的鸡胚DRG神经突起生长和维持DRG神经元存活具有增强作用,提示二者的联合应用可能为治疗神经元损伤及变性疾病的应用提供了新的数据和实验依据。     

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.