大鼠脑缺血再灌流时神经元损伤与星形胶质细胞的反应

为探讨星形胶质细胞在缺血性神经元损伤中的作用及其与神经元损伤的关系 ,本实验阻塞大鼠大脑中动脉 2 h,再灌流0 .5～ 48h建立短暂局灶性脑缺血模型 ,进行 H-E染色 ;通过胶质原纤维酸性蛋白和细胞核增殖抗原免疫组化单重或双重反应 ,TU NEL和胶质原纤维酸性蛋白免疫组化双重反应观察了神经元和星形胶质细胞的反应。结果表明 :再灌流 2 4h缺血区面积最大 ,再灌流 6h开始出现神经元不可逆变性 ,2 4h梗塞成熟 ;星形胶质细胞表现为反应性、营养不良性和退形变三种不同的形态特点。再灌流 48h时星形胶质细胞数量开始增多。 48h之内星形胶质细胞无增生 ,且有少量星形胶质细胞凋亡。这些结果提示脑缺血时星形胶质细胞反应与神经元损伤密切相关 ,反应性星形胶质细胞是其积极应答神经元损伤的结果 ,在维持神经元存活中起作用。     

小鼠脑缺血再灌流对铁及其调节蛋白在神经胶质细胞内分布的影响──免疫组织化学观察

应用免疫组织化学、荧光双标记和组织化学方法,对双侧颈总动脉反复短暂缺血造成再灌流损伤的小鼠部分脑区（额、颞叶大脑皮质、海马、胼胝体、丘脑和纹状体）中的铁、铁蛋白和转铁蛋白的分布变化进行了观察。结果显示：在正常状况下,铁蛋白和转铁蛋白阳性细胞以少突胶质细胞为主,部分星形胶质细胞也显示阳性反应,阳性细胞分布密度在胼胝体、丘脑和纹状体内较高,在皮质和海马处较低。铁阳性细胞也是少突胶质细胞,分布密度同铁蛋白阳性细胞。缺血再灌流损伤后,在上述脑区中铁蛋白和转铁蛋白阳性的少突胶质细胞密度下降;而星形胶质细胞及小胶质细胞除反应性增生外．部分仍含有铁蛋白或转铁蛋白,神经元呈弱阳性。铁的含量变化不大。提示少突胶质细胞在缺血、缺氧后,因铁代谢失调造成损伤,说明铁及其调节蛋白参与了缺血再灌流的病理过程。同时星形胶质细胞和小胶质细胞在铁代谢调节中可能起到一定的代偿作用。本文还对神经胶质细胞在缺血再灌流损伤与修复中的地位进行了讨论。     

脑缺血再灌流后海马区胶质纤维酸性蛋白的动态表达及意义

本研究目的在于 :观察脑缺血再灌流后海马区胶质纤维酸性蛋白的分布及动态表达 ,探讨其与缺血性神经元的联系。钳夹沙土鼠的双侧颈总动脉制造脑缺血模型 ,应用免疫荧光法染色。结果显示 :脑缺血再灌流后胶质纤维酸性蛋白的阳性反应主要分布于海马本部的始层、放射层、分子层及齿状回门区。再灌流 3 d,胶质纤维酸性蛋白反应增强 ;7～ 15 d,胶质纤维酸性蛋白反应达高峰 ;脑缺血再灌流 40 d和对照组相比胶质纤维酸性蛋白阳性反应仍维持较高水平。再灌流 3 0～ 40 d,CA1区锥体层胶质纤维酸性蛋白阳性细胞明显增强。本研究结果表明 :脑缺血再灌流后海马区星形胶质细胞活化及胶质纤维酸性蛋白表达增强长期保持在较高水平 ,星形胶质细胞的活化、增生可作为神经元受损可靠而敏感的指标     

阿尔茨海默病大鼠氢质子磁共振波谱研究

目的:探讨海马注射β-淀粉样肽(Aβ1-42)诱发阿尔茨海默病(AD)大鼠模型的病理学变化及氢质子磁共振波谱(~1H MRS)特性。方法:健康SD大鼠40只,实验随机分为假伤组(Sham组)、阿尔茨海默病模型(AD组)。采用大鼠海马注射Aβ_(1-42)复制AD模型。苏木精-伊红染色法染色观察海马CA1区神经元形态,免疫化学染色观察Aβ的沉积,采用Morris水迷宫法进行大鼠记忆功能的测定。~1H MRS检测AD鼠脑中的N-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)和乳酸(Lac)水平。结果:与Sham组比较,AD组游全程时间延长,错误次数增加,差异显著(均P0.01)。与Sham组比较,AD组双侧海马CA1区神经元数目减少,核固缩增加;且与注射对侧比较,Aβ_(1-42)注射侧大鼠海马CA1区神经元数目显著减少,核固缩显著增加。免疫化学染色Sham组呈阴性;AD组双侧抗Aβ1-42呈阳性,且与注射对侧比较,注射侧阳性显著增加。~1H MRS结果Sham组双侧半球无显著性差异。与Sham组比较,AD组双侧~1H MRS海马NAA/Cr明显降低、Cho/Cr增加、Lac/Cr增加;在AD组,与注射对侧半球比较,注射侧半球海马NAA/Cr明显降低(P0.05)、Cho/Cr显著增加(P0.01)、Lac/Cr显著增加(P0.01)。结论:Aβ1-42能引起大鼠海马CA1区神经元损伤,记忆功能下降,注射Aβ后4周NAA/Cr已有明显改变,与免疫组化发现Aβ1-42表达增强结果一致,提示利用~1H MRS检测NAA/Cr改变,可能有助于AD早期临床诊断。     

大鼠脑缺血再灌流时即早基因c-fos在脑组织表达的免疫组织化学研究

为了研究 c-fos在大鼠缺血性脑损伤中的作用 ,本研究利用阻塞大鼠大脑中动脉 2 h后再灌流 0 .5～ 48h制成的局灶性脑缺血模型 ,用免疫组织化学技术观察了 c-fos的表达特点。结果证明 ,正常组、假性手术组 c-fos在神经元的表达呈阴性或弱阳性 ;再灌流 0 .5～ 48h组 ,胞核呈强阳性 ( +++)的神经元主要位于非大脑中动脉供血区 ,而缺血中心区的皮质、纹状体和视前区呈阴性 ( -)。缺血周边区 ,神经元胞核呈弱阳性 ( +)。正常组未发现 c-fos阳性的胶质细胞 ,假性手术组脑实质内胶质细胞团和侧脑室壁的胶质细胞 c-fos呈强阳性 ,再灌流 3h组脑室壁及深层的室管膜下区和皮质浅层、髓质等处胶质细胞为阳性 ,再灌流2 4～ 48h组缺血周边区和脑实质内的巨噬细胞、活化小胶质细胞呈强阳性 ;再灌流 48h组 ,白质如胼胝体内大量的反应性星形胶质细胞呈强阳性。本文结果提示 ,脑缺血时 c-fos对神经元具有神经保护作用 ,并且这种保护作用可能与小胶质细胞和星形胶质细胞的活化有关     

首发抑郁症患者海马质子磁共振波谱成像研究

目的:探讨首发抑郁症患者海马的磁共振质子波谱(1HMRS)特点.方法:应用1HMRS成像技术检测21例未用药首发抑郁症患者和14例健康志愿者海马N-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)3种代谢物,计算NAA/Cr和Cho/Cr比值.结果:首发抑郁症患者组双侧海马NAA/Cr比值低于对照组,差异有统计学意义(右侧:0.88±0.29/1.37±0.51,P=0.004;左侧:0.76±0.33/1.40±0.99,P=0.034);Cho/Cr比值两组间无统计学差异(P＞0.05);双侧海马NAA/Cr和Cho/Cr与抑郁严重度无相关性(P＞0.05).结论:首发抑郁症患者可能存在双侧海马神经元活力和功能下降.     

大鼠大脑中动脉缺血后海马星形胶质细胞反应的研究

目的:观察大鼠大脑中动脉缺血后皮层损伤侧海马星形胶质细胞反应的变化。方法:采用大鼠大脑中动脉阻塞再灌流模型,应用免疫印迹和免疫组织化学方法测定脑缺血后3 d、7 d以及30 d皮层损伤侧海马胶质纤维酸性蛋白(GFAP)以及增殖细胞核抗原(PCNA)蛋白的表达,观察星形胶质细胞增殖的变化。结果: GFAP免疫组化结果显示,脑缺血后7d皮层损伤侧海马CA1、CA2区星形胶质细胞数量较假手术组增加且胞体增大;脑缺血后30 d皮层损伤侧海马CA1、CA2区呈胶质疤痕样改变。同时,免疫印迹法显示脑缺血后7 d皮层损伤侧海马GFAP表达增强;脑缺血后30 d皮层损伤侧海马GFAP表达增高更加明显。此外,免疫印迹法显示脑缺血后3 d皮层损伤侧海马PCNA蛋白表达水平升高;脑缺血后7 d PCNA蛋白表达水平达到峰值;脑缺血后30 d,PCNA蛋白表达水平降低,但仍高于假手术组。结论: 大鼠大脑中动脉缺血后可引起其皮层损伤侧海马星形胶质细胞过度反应和增殖。     

短暂性脑缺血再灌注对大鼠脑PGRN表达的影响

目的检测短暂性脑缺血再灌注早期,大鼠的额颞叶皮质、海马及纹状体中颗粒蛋白前体(progranulin,PGRN)的表达变化,为进一步探讨PGRN对脑缺血的治疗提供实验基础。方法 SPF级成年SD大鼠随机分为2组,假手术组(shamoperation group)和实验组(MCAO group)。用线栓法制作右侧大脑中动脉阻塞(MCAO)1 h,然后再灌注30 min、2 h、12 h、24 h模型,以缺血侧为实验组(ipsilateral group),其对侧为对照组(contralateral group)。假手术组为处理对照。用TTC染色法观察缺血梗死体积。用免疫荧光组织化学法和Western-blot分别检测PGRN的细胞定位及其表达变化。结果 TTC染色表明,脑缺血区域呈现白色,而对照无缺血区为红色。免疫组织化学结果提示,PGRN在神经元中大量表达,在小胶质细胞中有少量表达,而在星形胶质细胞中几乎无表达。Western blot结果提示,与对照组相比,缺血再灌注后2 h大鼠脑额颞叶皮质的缺血侧与非缺血侧PGRN含量均显著上调。在海马区缺血再灌注能瞬间降低PGRN水平,随着时间延长PGRN表达水平在24 h逐步恢复到正常水平。与皮质和海马相比,纹状体在短时间再灌注后PGRN具有较高的表达,特别是在缺血再灌注24 h后。结论短暂性脑缺血再灌注能显著影响PGRN在大鼠脑缺血区及半暗带区的水平,提示PGRN可能参与缺血后脑的调节。     

雷公藤多甙对大鼠海马内注射β-淀粉样蛋白后星形胶质细胞增生的影响

目的：探讨大鼠海马内注射v淀粉样蛋白1-40(Aβ1-40)后海马星形胶质细胞表达GFAP的变化及雷公藤多甙(TWP)对其的影响。方法：在大鼠左侧海马定向注射Aβ1-40作为Aβ组，注射生理盐水作为对照组，雷公藤多甙腹腔注射治疗海马内注入了Aβ1-40的大鼠为TWP组。用免疫组织化学方法观察各组大鼠海马星形胶质细胞GFAP的表达。结果：Aβ组海马星形胶质细胞增生、肥大，GFAP阳性细胞数增多，细胞截面积明显增大。TWP组星形胶质细胞数较Aβ组减少，并且细胞截面积明显缩小。结论：雷公藤多甙能抑制Aβ诱导的海马星形胶质细胞的反应性增生。     

局灶性脑缺血再灌注时神经元、胶质细胞形态变化与TNF-α、c-Myc表达相关的实验研究

目的:探讨局灶性脑缺血再灌注时神经元、神经胶质细胞形态变化特点和TNF-α、c-Myc表达的相关性。方法: 采用线栓法大鼠大脑中动脉阻塞复制局部脑缺血再灌注模型,缺血2 h分别再灌注1 d、3 d、7 d,应用光镜和免疫组化法,观察缺血侧额顶叶皮质神经元,神经胶质细胞形态变化及TNF-α、c-Myc蛋白表达。结果: 局灶性脑缺血再灌注后,同侧额顶叶皮质梗死区神经元、小胶质细胞、星形胶质细胞出现变性、坏死,梗死灶周围小胶质细胞和星形胶质细胞增生,呈现时间相关性,变性、死亡以再灌注3 d最为显著,星形胶质细胞和小胶质细胞增生以再灌注7 d最为显著且位于梗死周围区。再灌注后,TNF-α、c-Myc阳性细胞表达也显著增加,以再灌注3 d最为显著,且主要表达于星形胶质细胞、小胶质细胞,少量表达于神经元。结论: 脑缺血再灌注后神经元、神经胶质细胞之间在损伤、抗损伤及修复中相互影响,而TNF-α、c-Myc蛋白表达的增加可能是联系不同细胞间相互作用的主要调节物质之一。     

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 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.     

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.