流体切应力对中性粒细胞内Ca2+的影响

流体切应力是中性粒细胞的重要功能环境 ,但以往的研究很少涉及力学作用对中性粒细胞的影响。我们利用旋转粘度仪提供的流体切应力作用于分离的中性粒细胞 ,采用Fura 2 /AM与细胞内游离Ca2 结合 ,检测其荧光强度 ,研究不同力学条件下细胞内游离Ca2 浓度的变化情况 ;另外 ,分别以f MLP和TNF两种刺激因子作用中性粒细胞 ,使之激活 ,与此同时考察流体力学作用对中性粒细胞激活程度的影响。结果显示 :定常剪切流 ,切变率由低变高时 ,中性粒细胞内的游离Ca2 水平先是显著下降 ,切变率达到一定程度后 ,[Ca2 ]i逐渐回升 ,并且会超过静止时的水平 ;两种刺激因子在静态下激活中性粒细胞均可使游离Ca2 大幅度上升 ,同时给予定常流作用 ,在较低切变率作用下 ,这一上升被明显抑制 ,当切变率升高到一定程度后 ,[Ca2 ]i回复到静态激活水平甚至更高。正弦振荡剪切作用于中性粒细胞 ,[Ca2 ]i随最大切变率增大而升高 ,当激活剂和剪切流同时作用时 ,[Ca2 ]i随最大切变率升高而下降 ,逐渐接近最大切变率相同时的单纯振荡切应力作用的水平。由此我们认为 :体内不同血流环境将影响中性粒细胞的 [Ca2 ]i,在不同循环部位的血管血流中 ,流体切应力对中性粒细胞的 [Ca2 ]i有着不同的调节作用。     

雌激素的膜受体机制

细胞膜存在雌激素受体的非基因组效应。 17β-雌二醇〔E2 〕胞膜受体 ,通过增加Ca2 + 内流和环核苷酸途径诱导快速信号转导过程 ,如磷酸肌醇 3-激酶系统、蛋白激酶B/AKT系统、ERK和P38MAP激酶系统转导通路。这些通路使E2 膜效应与细胞其他功能紧密衔接 ;E2 非基因组效应参与神经和血管细胞调节作用。E2 受体池假说很好地解释E2 基因组和非基因组效应的协调性和统一性     

孕酮对正常生育男性精子头部胞浆内游离钙离子浓度（[Ca^2＋]i）的影响

目的：定量分析生育男性获能后单个精子的[Ca^2 ]i基础水平以及10μM孕酮刺激后的[Ca^2 ]i动态改变。方法：生育健康男子10例，手淫法留取精液。精液液化后，应用上游技术分离活动良好的精子，之后将精子悬液置于3‘70C培养2h使之获能。获能后精子移人Petri培养皿，每皿加入终浓度为8．85μmoL／L的钙荧光探针Fluo-3／AM，370C避光孵育40min。     

急性缺氧对大鼠远端肺静脉平滑肌细胞内钙浓度的影响

目的:研究急性缺氧对大鼠远端肺静脉平滑肌细胞(PVSMC)细胞内钙浓度([Ca2+]i)的影响及L型电压依赖性钙通道(VDCC)阻断剂硝苯地平的作用,为缺氧性肺动脉高压发病机制的进一步研究提供理论依据.方法:胶原酶消化法培养大鼠远端PVSMC,利用荧光显微镜和细胞内钙浓度检测系统观测急性缺氧(4％O2)、高钾(60 mmol/L KCl)溶液对PVSMC的[Ca2+]i影响及硝苯地平的干预作用.结果:对照组PVSMC的[Ca2+]i随时间变化维持基线水平;缺氧组PVSMC急性缺氧后,[Ca2+]i迅速升高并维持平台水平,△[Ca2+]i达82.83 nmol/L士23.03 nmol/L;硝苯地平干预组PVSMC予急性缺氧和5μmol/L硝苯地平干预后,[Ca2+]i升高幅度较小;高钾溶液孵育PVSMC后,[Ca2+]i迅速增高,5 μmol/L硝苯地平能完全阻断PVSMC的[Ca2+]i对高钾溶液的反应.结论:急性缺氧可使大鼠远端PVSMC的[Ca2+]i升高,其机制可能与激活PVSMC的VDCC和另外的非VDCC依赖的钙通道导致细胞外Ca2+内流有关.     

外源性锌对缺氧神经元的保护作用

目的:观察不同浓度外源性锌对神经元细胞内游离钙([Ca2 ]i)的影响,探讨低浓度外源性锌对于缺氧神经元保护作用的可能机制.方法:原代培养大鼠皮层神经元,加入不同浓度的外源性锌,激光扫描共聚焦显微镜检测神经元[Ca2 ]i的变化;建立细胞缺氧模型,检测10 μmol/L外源性锌对于缺氧神经元[Ca2 ]i和[Zn2 ]i的影响.结果:神经元的[Ca2 ]i,μmol/L锌组与对照相比无明显变化;100μmol/L锌组一过性升高,后降至对照水平;500 μmol/L锌组,明显高于对照水平.除正常加锌组外,其余各组神经元[Zn2 ]i和[Ca2 ]i均较正常对照组增高;但正常加锌组、缺氧加锌组神经元[Zn2 ]i和[Ca2 ]i均较缺氧组降低.结论:外源性锌对于神经元的作用随浓度而不同;10 μmol/L外源性锌维持了神经元的钙稳态,它对于缺氧神经元的保护作用,可能通过抑制钙超载实现.     

PTCA围手术期硫氮(艹卓)酮对血小板活性和钙动力学的影响

目的 :研究硫氮  酮对内皮损伤后血小板激活的影响及与胞浆Ca2 浓度的关系。方法 :35例拟行PTCA治疗的心绞痛患者随机分成对照 (C)组和硫氮 艹卓 酮治疗 (D)组 ,由冠状静脉窦和外周静脉采血 ,检测围术期血小板GPⅡb/Ⅲa表达和胞浆Ca2 浓度。并在体外研究不同浓度硫氮 艹卓 酮对稳定型心绞痛患者全血GPⅡb/Ⅲa表达的影响。结果 :C组首次球囊扩张后 5min、10min和PTCA后 10min时GPⅡb/Ⅲa表达和 [Ca2 ]i明显升高 ,而D组未见升高。高于治疗浓度的硫氮 艹卓 酮 (2 0 0 μg/L以上 )显著抑制GPⅡb/Ⅲa表达。 结论 :硫氮 艹卓 酮和阿司匹林 /抵克力得联合治疗可防止常规阿司匹林 /抵克力得治疗时发生的血小板激活。硫氮 艹卓 酮抗血小板作用可能是抑制[Ca2 ]i升高的结果 ,但只在高于治疗浓度时有效     

急性给予ApoE4升高大鼠皮层神经元内静息[Ca~(2+)]i

目的研究载脂蛋白E(ApoE)对大鼠皮层神经元内游离钙离子水平[Ca2+]i的影响。方法用激光共聚焦显微镜(LSCM)和Fluo-3/AM荧光探针标记检测皮层神经元钙信号瞬间动态变化;用N-甲基-D-天冬氨酸(NMDA)受体阻断剂MK-801观察ApoE4对其影响。结果ApoE4可以呈时间及浓度依赖性升高神经元内静息[Ca2+]i(P<0.01或P<0.05),MK-801可以部分阻断ApoE4所致的静息[Ca2+]i升高(P<0.05或P<0.01);而ApoE3无影响。结论急性给予ApoE4能升高神经元内静息[Ca2+]i,NMDA受体的激活可能参与了ApoE4所致的胞内钙信号改变与其神经毒作用。     

芦荟大黄素影响巨噬细胞升高[Ca~(2 )]_i和释放TNF-α的作用特征

应用MTT法检测肿瘤坏死因子(TNF-α)量,同时利用细胞钙离子成像分析系统检测单细胞内自由钙离子浓度([Ca2 ]i)的动态变化,来研究芦荟大黄素(aloe-emodin)对正常的和细菌脂多糖(LPS)刺激的大鼠腹腔巨噬细胞(PMψ)释放TNF-α和[Ca2 ]i的影响。结果显示,芦荟大黄素可较强活化正常PMψ释放TNF-α,同时诱发正常PMψ[Ca2 ]i呈振荡式变化,[Ca2 ]i变化主要来源于胞外钙内流。药物升高细胞[Ca2 ]i和促进TNF-α释放都随其浓度增加而增强。芦荟大黄素对LPS刺激的PMψ的影响有较复杂的剂量依赖性特征:低浓度芦荟大黄素(10-7 mol／L、10-6 mol／L)抑制LPS诱发的[Ca2 ]i升高和TNF-α的释放;10-5 mol／L的芦荟大黄素则对LPS诱发的[Ca2 ]i峰及TNF-α释放量没有明显影响。以上结果说明,芦荟大黄素对PMψ释放FNF-α和升高[Ca2 ]i表现出双向调节作用,但其活化正常PMψ和抑制LPS的刺激作用有相反的量一效关系。同时芦荟大黄素对PMψ的[Ca2 ]i动力学的调制,是其调节细胞释放TNF-α的信号传导通路中的重要环节。     

ATP通过P2Y1受体引发脊髓背角星形胶质细胞[Ca2+]i升高和GFAP表达上调

目的 观察体外培养的背角星形胶质细胞P2Y1受体激活对其[Ca2 ]i的变化和GFAP表达的影响.方法 培养并纯化脊髓背角星形胶质细胞,采用免疫组织化学染色观察背角星形胶质细胞P2Y1受体及GFAP的表达,激光共聚焦技术观察星形胶质细胞[Ca2 ]i的变化.结果 体外培养的大鼠脊髓背角星形胶质细胞大多表达P2Y1受体;P2Y受体激动剂ATP、ADP、ADP-βs剂量依赖性促进星形胶质细胞[Ca2 ]i升高;10 μg/mL的ATP、ADP和ADP-βs显著增加胞内[Ca2 ]i,此作用可被特异性P2Y1受体拮抗剂MRS2179所阻断,并具量效关系.免疫组织化学染色结果显示,100 μg/mL的ATP、ADP和ADP-βs作用下,星形胶质细胞GFAP表达上升,此效应可被100 μg/mL的MRS2179所抑制.结论 体外培养的大鼠脊髓背角星形胶质细胞表达P2Y1受体;P2Y1受体介导了ATP、ADP及ADP-βs促进星形胶质细胞[Ca2]i升高和GFAP表达增强的过程.     

雌激素保护神经作用研究现状

正雌激素(Estrogen)主要由雄激素经芳香化酶催化、并由卵巢产生,它是人体内常见甾体类固醇激素。人体雌激素有三种类型,17-β雌二醇(17-βestradio,17-βE2)、雌酮(Estrone)和代谢产物雌三醇(estriol),生物效能最强的是17-βE2。雌激素在神经系统中的明显保护作用是近年发现的一大重要作用~([1-3])。雌激素发挥作用是与细胞内受体结合,但它抑制细胞凋亡是通过抗氧化应激、抗炎和细胞增殖等途径     

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.