肾上腺素对U251细胞增殖及凋亡的影响

目的:探讨肾上腺素对人胶质瘤细胞系U251细胞增殖、凋亡、周期的作用。方法:应用RT-PCR方法检测U251细胞中β-肾上腺素能受体(β-AR) mRNA的表达。MTT法检测肾上腺素对U251细胞增殖的影响;克隆形成实验检测肾上腺素对U251细胞克隆形成的影响; Annexin V-FITC/PI检测肾上腺素对U251细胞凋亡的影响;流式细胞术检测肾上腺素对U251细胞周期的影响; Western Blot检测周期、凋亡和自噬相关蛋白表达变化。结果:人胶质瘤细胞U251表达β-AR;肾上腺素以浓度依赖性的方式抑制U251细胞增殖(P 0. 05);肾上腺素抑制U251细胞的克隆形成(P 0. 05);流式结果显示,随着肾上腺素浓度的增加,细胞的凋亡率明显增加(P 0. 05),G_0/G_1期细胞比例显著增加(P 0. 05),G_2/M期细胞比例下降(P 0. 05);肾上腺素处理U251细胞48 h,细胞周期蛋白Cyclin D表达下调,促凋亡蛋白Bax表达上调,自噬相关蛋白LC3-II/LC3-I比值升高。结论:肾上腺素可能通过激活细胞自噬抑制人胶质瘤细胞的增殖,使细胞阻滞在G_0/G_1期。     

去甲肾上腺素促进血管平滑肌增殖和细胞表型转化

目的:研究去甲肾上腺素(NE)对血管平滑肌细胞(VSMC)表型转化和增殖的影响及作用机制.方法:用NE分别作用体外培养和血清饥饿的血管平滑肌细胞,用5-BrdU标记VSMC的增殖、RT-PCR检测VSMC表型标志基因SM22a和增殖负性调控基因高血压相关基因-1(HRG-1)的表达.结果:NE和OX-LDL分别作用血清培养的VSMC后,SM22α和HRG-1表达下凋,5-BrdU标记的阳性增殖细胞增多;NE分别与α1-肾上腺素受体拮抗剂(α1-R-)和β1-肾上腺素受体拮抗剂(β1-R)共作用时,SM22α和HRG-1的表达明显上调.而当NE作用血清饥饿VSMC时,NE上调SM22α和HRG-1的表达.结论:NE对VSMC有促表型转化和增殖作用,且这种作用呈现像神经样的可逆性调节作用.其作用机制主要通过肾上腺索受体α1和β1来实现的.     

洛沙坦抑制β-肾上腺素能刺激诱导的大鼠心肌细胞凋亡的机制研究

目的:研究洛沙坦(Los)能否抑制β-肾上腺素能刺激诱导的大鼠心肌细胞凋亡,及其抑制凋亡的作用机制.方法:体外培养大鼠H9c2心肌细胞株,将其分为对照组、异丙肾上腺素(ISO)组、ISO+Los组、LY294002组和DMSO组,用流式细胞术和琼脂糖凝胶电泳观察心肌细胞的凋亡状态,通过RT-PCR检测凋亡相关基因的表达,Western blotting检测磷酸化Akt(p-Akt)和总Akt(t-Akt)蛋白水平的表达变化,放射免疫法检测各组细胞cAMP的含量.结果:10 μmol/L ISO可诱导H9c2心肌细胞凋亡,并伴有bax/bcl-2和caspase-9表达增高以及cAMP水平升高;加入10μmol/L Los后可明显抑制细胞凋亡的发生,bax/bcl-2和caspase-9表达减少,同时p-Akt的蛋白水平显著升高,而cAMP的水平降低;当加入LY294002阻断Akt活化后则可增加细胞凋亡的发生,从而取消Los对ISO诱导凋亡的保护作用.结论:ISO通过慢性刺激β-肾上腺素能受体(β-AR)可诱导心肌细胞凋亡,Los通过干扰β-AR下游信号转导通路并增加Akt活化,从而抑制β-肾上腺素能刺激诱导的心肌细胞凋亡.     

去甲肾上腺素对培养心肌细胞肥大和凋亡的作用

目的:研究不同剂量去甲肾上腺素(NE)对培养心肌细胞肥大和凋亡的影响。方法:心肌细胞暴露于NE,观察心肌细胞形态变化,通过心肌细胞蛋白质含量、[3H]亮氨酸掺入率检测心肌细胞肥大;透射电镜、DNA Ladder和流式细胞术检测心肌细胞凋亡。结果:1和10μmol/L NE可明显增加心肌细胞蛋白含量和[3H]亮氨酸掺入率,并有呈剂量依赖性升高的趋势;50μmol/L NE更可明显增加心肌细胞凋亡率;100μmol/L NE使心肌细胞凋亡率明显增高并出现超微结构改变和DNA梯状带纹。结论:低浓度NE主要诱导心肌细胞肥大,高浓度NE主要诱导心肌细胞凋亡,中浓度NE兼有两种功能。     

β1-肾上腺素受体自身抗体对大鼠B淋巴细胞增殖的影响

目的 探讨β1-肾上腺素受体自身抗体(β1-AA)对大鼠B淋巴细胞增殖的影响.方法 本研究以主动免疫大鼠的方法获得β1-AA阳性的IgGs (pIgGs);免疫磁珠分选技术获得大鼠B淋巴细胞;CCK8法检测B淋巴细胞的增殖能力.结果 β1-AA(0.1 μmol/L pIgGs)促进LPS刺激的大鼠B淋巴细胞增殖(A值:0.739±0.036 vs 0.533±0.032,P＜0.05),且有浓度依赖性的趋势;该效应可以分别被β1/β2-肾上腺素受体(β1/β2-AR)阻断剂部分阻断,被两种阻断剂共同作用完全阻断;pIgGs对静息的大鼠B淋巴细胞无增殖作用.结论 β1-AA可能通过B淋巴细胞表面的β1-AR和/或β2-AR信号通路促进激活的B淋巴细胞增殖.     

β-肾上腺素能刺激促进离体小鼠心脏缺氧/复氧诱导的细胞凋亡

目的：观察β-肾上腺素能刺激与缺氧/复氧损伤对离体小鼠心脏细胞凋亡的影响。 方法： 逆行灌注离体小鼠心脏，观察不同剂量异丙基肾上腺素（Iso）和不同时间缺氧/复氧心肌细胞凋亡率的变化，并观察β1-肾上腺素能受体阻滞剂、caspase-拮抗剂、Bcl-2对其凋亡率的影响，以TUNEL法检测心肌细胞凋亡率。 结果： 单独Iso未引起心肌细胞凋亡率的变化，但可增加缺氧/复氧所诱导的细胞凋亡率；Bcl-2转基因鼠细胞凋亡率明显低于正常小鼠；β1-受体拮抗剂（美托洛尔）及caspase -拮抗剂（zVAD.fmk）可明显抑制Iso和缺氧/复氧所致细胞凋亡。 结论： β-肾上腺素能受体激动剂可促使缺氧/复氧所诱导心肌细胞凋亡，其诱导凋亡的作用主要通过β1-受体介导，β1-受体拮抗剂可抑制二者共同作用所诱导心肌细胞凋亡。     

乙酰胆碱抑制去甲肾上腺素诱导的心肌H9c2细胞凋亡

目的:探讨乙酰胆碱(ACh)对去甲肾上腺素(NE)诱导心肌H9c2细胞凋亡的作用及机制。方法:用不同浓度(0、5、10和20μmol/L)NE诱导心肌H9c2细胞凋亡,用ACh预处理细胞观察其作用,用MTT法检测细胞存活率,选出最适NE和ACh剂量。其次,分别加入与凋亡密切相关的4种信号分子阻断剂与ACh共同干预,用激光共聚焦成像JC-1法检测线粒体膜电位水平,DCFH-DA染色及流式细胞术检测胞内活性氧簇的水平,Annexin V-FITC/PI染色及流式细胞术检测细胞凋亡情况。结果:10μmol/L NE可明显诱导H9c2细胞凋亡(P0.05);经10μmol/L ACh预处理后,可减弱NE诱导的H9c2细胞凋亡(P0.05);在ACh预处理前分别预先加入4种分子阻断剂,发现加入PDTC后可减弱ACh的抑制作用。结论:ACh具有抑制NE诱导的心肌H9c2细胞凋亡的作用,其机制可能与NF-κB信号分子有关。     

交感神经末梢调节损伤感觉神经元兴奋性的一种新方式(英文)

本研究观察到育亨宾对受损背根节 (DRG)神经元呈现兴奋作用 ,并初步研究了其发生机制。用外源性育亨宾 (10μmol/L)灌流损伤 DRG时 ,在 2 2个有自发放电的 DRG神经元中有 18个神经元产生明显反应。育亨宾对损伤神经元的兴奋作用可被α1 -肾上腺素受体拮抗剂哌唑嗪 (5μmol/L )明显阻断。用 6 -羟多巴胺化学性交感神经切断和胍乙啶耗竭交感末梢后 ,育亨宾的兴奋作用均明显减小。结果显示 :育亨宾阻断交感节后神经末梢上的α2 -肾上腺素受体 ,引起去甲肾上腺素 (NE)的释放 ;释放的NE作用于损伤 DRG神经元上的α1 -肾上腺素受体呈现兴奋作用。提示交感节后神经末梢可能存在一种持续性抑制 NE释放的新机制 ,这种抑制作用不依赖交感节后神经节和动作电位的存在     

雌激素对培养新生大鼠心肌细胞凋亡的影响

目的探讨17β雌二醇（E2）对去甲肾上腺素（NE）诱导的培养心肌细胞凋亡的影响及其可能机制。方法培养的新生大鼠心肌细胞分别给予NE（50μmol／L）、E2（10nmol／L）、NE（50pmol／L）＋E2（10nmol／L）作用48h,倒置相差显微镜和透射电镜观察心肌细胞形态结构的变化;DNA ladder和流式细胞术对心肌细胞凋亡情况进行定性和定量分析;免疫荧光细胞化学技术及半定量分析心肌细胞促凋亡基因c-fos的蛋白表达。结果E2抑制NE诱导的心肌细胞凋亡的特征性形态学改变如细胞萎缩,核染色质浓缩边集,线粒体肿胀,出现凋亡小体等;使凋亡心肌细胞特异性的DNA梯状条带消失;降低心肌细胞凋亡率并减弱凋亡心肌细胞内c-fos蛋白的表达。结论17β雌二醇可抑制去甲肾上腺素所诱导的心肌细胞凋亡,其机制可能与促凋亡基因c-fos的表达有关。     

三种不同β受体阻滞剂治疗小鼠血管瘤的实验研究

目的:比较三种不同β受体阻滞剂对小鼠血管瘤(EOMA细胞)细胞体内外的影响,初步探讨普萘洛尔对小鼠血管瘤的治疗作用及可能机制,为β受体阻滞剂治疗婴幼儿型血管瘤提供参考。方法:体外培养EOMA细胞,用不同浓度美托洛尔、普萘洛尔、布托沙明作用EOMA细胞,作用24 h。应用MTT法检测细胞存活率、吖啶橙染色检测细胞凋亡情况,观察美托洛尔、普萘洛尔、布托沙明对EOMA细胞体外增殖和凋亡的影响。体内实验将EOMA细胞移植裸鼠,待肿瘤体积生长至100 mm3,将动物随机分为4组,分别为对照组、美托洛尔组、布托沙明组和普萘洛尔组,药物组按2 mg/(kg·d)灌胃给药,对照组给予等体积的生理盐水(NS),每两天测量肿瘤体积大小。实验结束时收集血清,酶联免疫吸附实验检测血清中肿瘤坏死因子-α(TNF-α)和血管内皮细胞生长因子(VEGF)的表达水平。结果:体外实验显示,普萘洛尔作用24 h后,EOMA细胞存活率随剂量增加逐渐下降,50μmol/L时有显著差异(P0.05),药物增加至800μmol/L,细胞存活率接近10%。吖啶橙染色显示50μmol/L时凋亡细胞显著增多。美托洛尔、布托沙明作用24 h后,100μmol/L时细胞存活率与对照组相比有显著差异(P0.05),800μmol/L时细胞存活率下降至20%,明显高于相同浓度的普萘洛尔组,存在显著性差异(P0.05)。吖啶橙染色亦出现相似的规律。体内实验显示,实验结束时美托洛尔、布托沙明小鼠和普萘洛尔药物组的肿瘤体积分别为(1 642.8±89.3)、(1 529.3±119.1)和(752.7±46.5)mm3,与对照组小鼠的肿瘤体积(2 023.3±123.07)mm3相比明显减少(P0.001)。美托洛尔、布托沙明小鼠和普萘洛尔药物组血清中VEGF分别水平为(606.5±105.8)pg/ml、(534.3±243.2)pg/ml和(420.1±123.7)pg/ml,明显低于PBS对照组的[(825.8±145.7)pg/ml,(P0.05)],TNF-α结果依次是(301.3±62.3)pg/ml、(305.1±53.8)pg/ml和(288.8±59.5)pg/ml,明显低于正常对照组[(444±100.4)pg/ml,(P0.05)]。结论:三种β受体阻滞剂均可在体外有效抑制小鼠血管瘤EOMA细胞的增殖并促进细胞凋亡普萘洛尔的这一作用较布托沙明和美托洛尔明显。三种β受体阻滞剂不同程度的抑制小鼠血管瘤的生长,其中普萘洛尔的抑制作用明显强于美托洛尔和布托沙明。三种β受体阻滞剂均可降低体内VEGF和TNF-α的水平。提示普萘洛尔对小鼠血管瘤的作用可能与β1和β2受体协同作用有关,其治疗血管瘤的机制可能与VEGF和TNF-α有关。     

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.