共查询到20条相似文献,搜索用时 46 毫秒
1.
为研究亚纳秒脉冲联合温度对人宫颈癌(HeLa)细胞的杀伤效应, 将脉冲电场参数组合(电场强度25、50、100 kV/cm, 半峰值脉宽1 ns, 脉冲个数分别为4 000、1 000、250, 频率5 Hz), 作用于处于不同温度(25℃、43℃、48℃)的HeLa细胞, 利用MTT检测亚纳秒脉冲对细胞的生长抑制情况, 通过AO/EB染色和透射电镜观察细胞形态学变化, 采用免疫细胞化学S-P法检测caspase-3蛋白表达活性。实验发现:当细胞悬液温度到达48℃后, 随着时间推移细胞死亡率不断增加;采用亚纳秒脉冲电场(电场强度50 kV/cm, 半峰值脉宽1 ns, 脉冲个数1 000, 频率5 Hz)处理不同温度下HeLa细胞, 细胞悬液温度达到43℃后, 细胞死亡率达到18.07%±1.98%, 细胞悬液温度达到48℃, 细胞死亡率增至25.11%±6.05%;采用相同能量脉冲电场处理处于相同温度(48℃)的细胞悬液时, 细胞死亡率与脉冲场强正相关, 100 kV/cm电场作用下得到最高细胞死亡率为31.09%±5.03%, 进一步的分子生物学检测结果显示HeLa细胞发生凋亡效应。适当场强的亚纳秒脉冲联合温度通过诱导细胞凋亡, 进而杀死HeLa细胞。 相似文献
2.
背景:在前期研究基础上,设想将基因电转染作为脉冲电场治疗恶性肿瘤的辅助方法。
目的:探讨脉冲电场联合抑癌基因野生型p53基因诱导人宫颈癌hela细胞发生凋亡及相互作用。
方法:采用空质粒及含有野生型p53的质粒转染Hela细胞得到Hela-vector、Hela-p53细胞,将Hela细胞、Hela-vector和Hela-p53细胞分别施加固定脉宽100 μs、频率1 Hz、脉冲数8个、电场强度为1 500 V/cm的脉冲电场处理。
结果与结论:相同参数脉冲电场作用于各组细胞12 h后,MTT结果显示Hela-p53组细胞吸光度明显低于Hela组(P < 0.05);流式细胞仪及RT-PCR检测结果显示Hela-p53组的早期凋亡率和p53 mRNA表达较Hela组明显增加;Western bolt及激光共聚焦显微镜结果显示与Hela组比较,Hela-p53组细胞Bax蛋白表达明显上升,而Bcl-2蛋白则明显下降,Casepase-3相对荧光强度明显增强。表明野生型p53基因对宫颈癌Hela细胞生长有明显的抑制作用,野生型p53基因可以提高脉冲电场诱导宫颈癌Hela细胞凋亡的作用。 相似文献
3.
为研究陡脉冲电场的凋亡效应,以人肝癌细胞系为实验对象,采用激光扫描共聚焦显微镜观察陡脉冲电场作用下细胞内钙离子浓度的变化,采用流式细胞术Annexin V检测陡脉冲电场诱导细胞凋亡.结果发现,陡脉冲电场能使肝癌细胞内钙离子浓度发生变化,变化的程度与陡脉冲电场的参数和胞外是否有钙有关,使得细胞内钙离子浓度稳态失调或大幅度振荡;流式细胞检测结果证实了陡脉冲电场能有效诱导肝癌细胞凋亡(与对照组比较,P<0.01),并且较低的电压峰值、较宽的脉冲宽度(200V/1.3μs)比较高的电压峰值、较窄的脉冲宽度(600V/100ns)能更有效地(P<0.01)诱导肝癌细胞凋亡.实验结果为陡脉冲杀伤肿瘤细胞的机制和参数选择提供了依据. 相似文献
4.
纳秒级陡脉冲电场诱导癌细胞凋亡的实验及作用机理研究 总被引:3,自引:1,他引:3
观察纳秒级陡脉冲电场诱导人浆液囊腺性卵巢癌SKOV3癌细胞凋亡效应,及其对细胞内钙离子浓度即[Ca2+]i的影响并探讨其作用机理。采用场强为10kV/cm、脉宽为100ns、重复频率为1Hz的纳秒级陡脉冲电场作用于SKOV3癌细胞悬液5min。4h后采用Annexin V-FITC/PI双标记并结合流式细胞仪分析SKOV3癌细胞的凋亡率,采用扫描和透射电子显微镜观察癌细胞凋亡的超微结构变化;以Fluo-3/AM为细胞内钙离子的荧光指示剂,用激光扫描共聚焦显微镜检测纳秒级陡脉冲电场对SKOV3癌细胞[Ca2+]i的影响,及[Ca2+]i变化时的Ca2+来源。结果显示,流式细胞术检测到癌细胞的早期凋亡率为(22.21±2.71)%,明显高于对照组的(3.04±0.44)%(P〈0.01),扫描和透射电子显微镜均观察到典型的凋亡细胞形态,证实纳秒级陡脉冲电场能够有效诱导SKOV3癌细胞发生凋亡;同时纳秒级陡脉冲电场可明显升高细胞[Ca2+]i(P〈0.01),而与细胞外钙离子浓度无关(P〉0.05)。由于纳秒级陡脉冲电场的等值频率很高,容易穿透细胞膜,其诱导凋亡的机制之一可能是通过激活细胞内钙库(内质网、线粒体),引起细胞内钙离子升高,从而介导凋亡信号通路。 相似文献
5.
探讨脐血CIK细胞对K562细胞的杀伤活性及诱导凋亡作用。通过第1天在脐血淋巴细胞中加入IFN-r,第2天再加入IL-2和CD3单抗进行细胞培养获得多种细胞因子诱导的杀伤细胞(Cytokines induced killer cells)即脐血CIK细胞。用MTT法测定其抗肿瘤活性,原位末端标记法进行凋亡分析,台盼蓝拒染法计数细胞。脐血CIK细胞及培养上清抗K562活性明显优于CD3AK细胞,短期培养后其增殖活性低于CD3AK细胞;但是加入G-CSF可以提高CIK细胞的增殖活性,且CIK细胞的抗K562活性仍高于CD3AK细胞。CIK细胞诱导K562细胞凋亡率大于CD3AK细胞,G-CSF能部分抑制CIK细胞诱导的K562细胞的凋亡。脐血CIK细胞是一种有效的杀伤活化细胞,脐血在多种细胞因子适当组合的诱导下可提高杀瘤活性。 相似文献
6.
基于经典球形单细胞五层介电模型,并考虑电穿孔过程中细胞膜电导率的变化,对微秒脉冲电场作用下的细胞内外膜跨膜电压进行了仿真分析,以及脉冲电场诱导人宫颈癌细胞系Hela凋亡的实验研究。仿真分析发现,随着细胞穿孔程度的加剧,细胞膜电导率增加,内、外膜跨膜电压的比值不断增加,表明外加脉冲电场对内膜的影响不断增强,其作用靶点逐渐透过细胞膜进入胞内细胞器。同时,实验结果也表明随着脉冲电场场强不断增加,微秒脉冲电场所诱导的Hela细胞的凋亡率随之增加,从而间接证实了仿真分析的结果。现有研究普遍认为微秒脉冲电场的作用靶点为细胞外膜,本研究关于微秒脉冲电场对细胞内膜作用的研究结果是对已有研究的重要补充和发展。 相似文献
7.
苦瓜蛋白诱导K562细胞凋亡及其对Bcl-2、PCNA蛋白表达的影响 总被引:4,自引:0,他引:4
目的:观察苦瓜蛋白是否具有诱导K562细胞凋亡的生物学活性,探讨苦瓜蛋白对K562细胞Bcl-2及PCNA表达水平的影响及其作用的分子机制。方法:以一定浓度的苦瓜蛋白处理K562细胞12~72小时,CCK-8检测其对细胞生长的影响;流式细胞术(AnnexinV)、细胞形态学(光镜及电镜)等方法检测细胞凋亡;同时应用流式细胞术检测Bcl-2及PCNA蛋白表达的变化。结果:苦瓜蛋白对K562细胞生长具有明显的抑制作用;流式细胞术及形态学观察(光镜及电镜)证实一定作用浓度的苦瓜蛋白可诱导K562细胞发生明显的细胞凋亡,且随着作用时间的延长细胞凋亡率逐渐升高。苦瓜蛋白处理组K562细胞中Bcl-2及PCNA蛋白的表达分别为0.33%和98.36%,对照组分别为74.03%和97.63%。结论:苦瓜蛋白对K562细胞生长具有明显抑制作用,其作用主要通过诱导K562细胞产生细胞凋亡.而不是抑制细胞增殖。苦瓜蛋白诱导K562细胞凋亡过程中,Bcl-2蛋白表达的下调对调控细胞凋亡有重要作用。 相似文献
8.
纳秒级电场脉冲诱导肿瘤细胞凋亡的线粒体通路研究 总被引:4,自引:0,他引:4
将纳秒级电场脉冲作用于人卵巢癌(SKOV3)细胞,通过流式细胞仪检测细胞活性氧(ROS)、线粒体跨膜电位(MTMP)的变化情况,用免疫荧光法检测线粒体膜间隙凋亡相关蛋白释放情况;用Western blot法检测线粒体膜间隙凋亡相关蛋白表达及活化情况,以研究纳秒级电场脉冲诱导肿瘤细胞凋亡的线粒体通路.实验发现:经纳秒级电场脉冲处理后,细胞活性氧即刻升高,且线粒体跨膜电位在6 h时达到最低值;线粒体膜间隙蛋白释放入胞浆(P<0.05);线粒体凋亡通路相关蛋白表达最也明显升高(P<0.05).结果表明,在纳秒级电场脉冲诱导的肿瘤细胞凋亡中,线粒体凋亡通路参与并发挥了重要作用. 相似文献
9.
为研究陡脉冲电场的诱导凋亡作用,以体外人肝癌细胞SMMC-7721为实验对象,采用Annexin V-FITC/PI双染色并利用流式细胞术检测磷脂酰丝氨酸(PS)外翻,采用琼脂糖凝胶电泳检测DNA降解片段化.实验发现,陡脉冲电场能有效(P<0.05)地使PS外翻,并且微秒级陡脉冲(μsSPEF)比纳秒级陡脉冲(nsSPEF)更有效(P<0.05);陡脉冲电场能使DNA降解片段化,且nsSPEF比μsSPEF更有效.实验结果表明,陡脉冲电场能有效诱导体外人肝癌细胞凋亡,其机理与陡脉冲电场非热效应及其频谱特性有关.μsSPEF主要作用于细胞膜,而可能通过外源性通路诱导细胞凋亡;nsSPEF主要作用于细胞核和线粒体等胞内细胞器,可能通过内源性通路诱导细胞凋亡.实验结果为陡脉冲电场杀伤肿瘤细胞的机制和参数选择提供了依据. 相似文献
10.
目的:探讨重组灵芝免疫调节蛋白(rLZ-8)诱导K562细胞发生细胞凋亡相关机制的研究。方法:采用MTT法检测rLZ-8对K562细胞的体外杀伤作用;通过Annexin V/PI双染检测细胞凋亡率;应用钙离子荧光探针Fluo-3/AM染色,检测了rLZ-8作用K562细胞后细胞内钙离子浓度变化,分光光度法测定细胞caspase-3活性,还利用激光扫描共聚焦显微镜确定了rLZ-8在K562细胞内的亚细胞定位。结果:rLZ-8可明显杀伤K562细胞,并诱导其发生细胞凋亡;rLZ-8可提高K562细胞内的caspase-3活性,进一步确证了细胞凋亡的发生;激光扫描共聚焦显微镜下观察,rLZ-8可定位在细胞核中,并引起细胞内钙离子水平升高。结论:rLZ-8具有诱导K562细胞发生凋亡的作用,这种杀伤肿瘤细胞的作用可能与rLZ-8可富集在细胞核上的特性有关。 相似文献
11.
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. 相似文献
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 Gc
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. 相似文献
12.
Renal dysplasia and asplenia in two sibs 总被引:2,自引:0,他引:2
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. 相似文献
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. 相似文献
13.
Donald O. Rudin 《Medical hypotheses》1982,8(1):17-47
About 1900, modern food selection and processing caused widespread 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 ypovitaminosis B, i.e., a mixture of beriberi and pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse 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 . 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. 相似文献
14.
15.
Antonio Arnaiz-Villena Jose Palacio-Grüber Ignacio Juarez Ennio Hernández Ester Muñiz Brayan Bayona Cristina Campos Jorge Nieto Manuel Martin-Villa Carlos Silvera 《Human immunology》2018,79(4):189-190
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. 相似文献
16.
Newton H 《Medical history》2011,55(2):153-182
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. 相似文献
17.
C. R. Lipton J. X. Dautlick G. D. Grothaus P. L. Hunst K. M. Magin C. A. Mihaliak F. M. Rubio J. W. Stave 《Food and Agricultural Immunology》2000,12(2):153-164
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. 相似文献
18.
Ultracryotomy: development and application (with examples from the yeast cytology) (author's transl)
Konrad Joachim Böhm 《Acta histochemica》1980,66(1):59-84
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. 相似文献
19.
M G Baggot 《Medical hypotheses》1979,5(5):591-597
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. 相似文献
20.
G. Heinemann H. Schievelbein D. Eberhagen V. Rahlfs 《Journal of molecular medicine (Berlin, Germany)》1981,59(20):1165-1173
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. 相似文献