首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
目的 研究慢性粒细胞白血病(CML)骨髓来源的肿瘤干细胞的免疫学特征,比较其与正常人来源的间充质干细胞(MSC)是否存在免疫功能的异常.方法 分离正常人和CML患者骨髓中的MSC,MLR法检测其对T细胞增殖的影响,流式细胞术检测其对T细胞周期、凋亡的作用情况.结果 CML和正常志愿者骨髓来源的MSC的细胞形态和表型没有差异,CML患者来源的MSC抑制T细胞增殖能力和抑制T细胞停留在G0/G1期的作用均减弱(CML MSC组74.5%±1.2%,BMSC组94.0%±1.9%,P<0.05),CML患者抑制T细胞凋亡的作用增强(CMLMSC组8.36%±1.31%,BMSC组14.10%±0.65%,P<0.05).结论 CML患者骨髓来源的MSC存在明显的免疫调节功能缺陷,如果使用CML患者自体的MSC移植治疗可能不是一种很好的选择,对于CML患者最好是选用异基因的MSC移植.  相似文献   

2.
背景:研究认为间充质干细胞可能是骨髓造血微环境的免疫保护位点。由于慢性粒细胞白血病存在造血微环境异常和免疫异常,所以推测间充质干细胞可能在慢性粒细胞白血病的病理过程中扮演了一个重要角色。 目的:观察慢性粒细胞白血病骨髓来源的肿瘤干细胞的免疫学特征,比较其与正常人来源的间充质干细胞是否存在免疫功能的异常。 方法:分离正常人和慢性粒细胞白血病患者的骨髓间充质干细胞,分别检测它们对T细胞周期、活化、抑制和增殖的作用。 结果与结论:慢性粒细胞白血病和正常志愿者骨髓来源的间充质干细胞形态和表型没有差异,慢性粒细胞白血病患者来源的间充质干细胞抑制T细胞增殖的作用减弱,抑制T细胞周期及活化的能力减弱,慢性粒细胞白血病患者抑制T细胞凋亡的作用增强。提示慢性粒细胞白血病患者骨髓来源的间充质干细胞存在明显的免疫调节功能缺陷,如果使用慢性粒细胞白血病患者自体的间充质干细胞移植治疗可能不是一种很好的选择,对于骨髓增生异常综合征患者最好是选用异基因的间充质干细胞移植。  相似文献   

3.
目的:观察骨髓增生异常综合征(MDS)患者来源的间充质干细胞(MSC)对混合淋巴细胞反应体系中的T淋巴细胞亚群的影响.方法:将MDS来源的MSC,按照不同比例加入双向混合淋巴细胞培养体系中共同孵育,3 d后采用流式细胞术(FCM)和ELISA法检测其表面抗原以及上清液中细胞因子的变化.结果:MDS来源的MSC能明显抑制共孵育体系中的CD8 +T细胞亚群和IFN-γ的分泌,轻度抑制IL- 4的分泌,与正常来源的MSC抑制性没有统计学意义.结论:MSC在体外能明显抑制CD8 +T细胞(CTL)和Th1细胞,轻度抑制Th2细胞.  相似文献   

4.
本研究中我们分离骨髓和脂肪的间充质干细胞,分别检测它们对T细胞周期、活化、抑制和增殖的作用情况,研究脂肪来源(adipose-derived mesenchemal stem cell,AMSC)和骨髓来源(bone marrow derived mesenchemal stem cell,BMSC)间充质干细胞的免疫学特征,比较它们是否存在免疫功能的差异,结果显示AMSC和BMSC均具有抑制T细胞增殖的能力,在有丝分裂原刺激和MLR的T细胞增殖中均具有剂量依赖性的,在1∶2时有极强的抑制作用,但是在1∶100时这种作用基本消失,在共培养时AMSC和BMSC都可使更多的T细胞被抑制在G0/G1期,同时也可以抑制T细胞的早期活化,但是上述作用AMSC均较BMSC弱,但是AMSC并不具有抑制T细胞凋亡的作用,而两者在Th0向Th1或Th2分化中所起的作用是基本相似的,主要抑制Th0向Th1细胞(IL-2和IFN-γ生成细胞)的分化,而对向Th2细胞(IL-4和IL-10生成细胞)分化没有明显的影响。所以,AMSC和BMSC具有类似的免疫调节作用,因AMSC取材方便而成为更佳的材料来源。  相似文献   

5.
背景:脂肪来源的间充质干细胞是否具有和骨髓来源间充质干细胞类似的免疫调节作用? 目的:观察骨髓来源和脂肪来源间充质干细胞的免疫学特征。 方法:分离骨髓和脂肪来源的间充质干细胞,分别检测它们对T细胞周期、活化、抑制和增殖的作用情况。 结果与结论:骨髓来源和脂肪来源的间充质干细胞同样具有抑制T细胞增殖的能力,在有丝分裂原刺激和混合淋巴细胞反应的T细胞增殖中这种作用都是具有剂量依赖性的,在1︰2时有极强的抑制作用,但是在1︰100时这种作用基本消失,在共培养时骨髓来源和脂肪来源的间充质干细胞都可以使更多的T细胞被抑制在G0/G1期,同时也可以抑制T细胞的早期活化,但是上述作用脂肪来源的间充质干细胞均较骨髓来源间充质干细胞弱,且脂肪来源的间充质干细胞并不具有抑制T细胞凋亡的作用。  相似文献   

6.
张千  邓存良 《基础医学与临床》2010,30(11):1222-1225
骨髓间充质干细胞(MSCs)是一群具有多向分化潜能的成体干细胞,具有抑制T细胞活化、调节异体移植的免疫耐受等免疫特性。肝移植是各种晚期肝病的主要治疗方法,但由于器官来源的缺乏和伴随的免疫排斥反应,其应用受到限制。研究证明骨髓是肝祖细胞的来源之一,在一定的条件下,骨髓间充质干细胞能够分化为功能性肝细胞并分泌相关细胞因子,促进肝细胞的再生,为临床治疗各种肝损害提供了新的途径。  相似文献   

7.
骨髓间充质干细胞(BMSC)具有独特的生物学特性,其免疫抑制作用引起了人们广泛的兴趣。大量资料表明,MSC能在同种异基因,甚至异种基因的环境中长期存活,并且保持它的多向分化潜能。这一特性使MSC异体移植预防和治疗免疫性疾病成为可能。因此有必要从问充质干细胞的低免疫原性、灯免疫细胞及补体系统的调节和诱导抑制性免疫微环境等方面探讨BMSC避免同种异体移植排斥反应的可能机制。  相似文献   

8.
背景:既往研究发现骨髓间充质干细胞具有免疫抑制作用,而再生障碍性贫血患者存在T淋巴细胞异常活化及增殖。 目的:体外分析骨髓间充质干细胞对再生障碍性贫血患者外周血T淋巴细胞增殖的抑制作用。 方法:分离再生障碍性贫血患者外周血T淋巴细胞,行羧基荧光素乙酰乙酸琥珀酰亚胺酯(CFDA SE)荧光染色,与体外培养扩增的骨髓间充质干细胞按3︰1比例直接接触法及Transwell法共培养,加入植物血凝素(PHA)刺激T淋巴细胞增殖,并设阴性及阳性对照。流式细胞术检测各组T细胞增殖情况,评价骨髓间充质干细胞对T淋巴细胞增殖的影响。 结果与结论:CFDA SE染色分析显示,直接接触组T细胞增殖较阳性对照组明显减低(P < 0.01);Transwell组T细胞增殖亦较阳性对照组减低(P < 0.05);直接接触组T细胞增殖较Transwell组明显减低(P < 0.01)。骨髓间充质干细胞可能通过直接接触及分泌某些细胞因子方式抑制再生障碍性贫血患者异常增殖的T细胞,以直接接触方式发挥主要作用。  相似文献   

9.
骨髓增生异常综合征(myelodysplastic syndromes,MDS)是一组肿瘤性疾病,以骨髓无效造血并向急性髓系白血病转化的风险为特点.流行病学显示自身免疫性疾病的患者发生MDS风险增加,为二者存在共同病因的假设提供了依据.MDS骨髓微环境中存在T细胞过度活化的现象.部分低危组MDS治疗药物具有抑制T细胞免疫机制,而高危组MDS的去甲基化药物则增强T细胞的抗肿瘤免疫反应,特别是免疫检查点抑制剂正在MDS中进行临床实验.因此,MDS中T细胞免疫失调的双重作用值得深思,充分认识T细胞免疫异常在M D S发病机制中的作用是形成新治疗方法的理论基础.  相似文献   

10.
目的研究人骨髓间充质干细胞(MSC)对T细胞周期和活化的影响,探讨MSC对T细胞增殖抑制的作用机制。方法Ficoll密度梯度离心法分离纯化人骨髓MSC,体外扩增培养3代后用于实验。应用流式细胞术分析MSC对PHA作用下T细胞周期和早期表型CD25、CD69表达的影响,ELISA法检测细胞因子水平。结果人骨髓MSC体外可使PHA刺激下的T细胞滞留于细胞周期的G0/G1期,下调活化T细胞早期表型CD25、CD69的表达,抑制IL-2、IFN-r的分泌。结论人骨髓MSC体外可通过对T细胞周期的影响抑制其活化和增殖。  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   

12.
About 1900, modern food selection and processing caused widespread 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 panhypovitaminosis B, i.e., a mixture of substrate beriberi and substrate pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse 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 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.  相似文献   

13.
Most bodily functions require the coordinated actions of complementary and supplementary paired muscle groups. Where this essential muscular cooperation is lacking, hollow organs may burst and others become literally screwed up, giving rise to many similar spastic diseases such as Torticollis, Twisted ovarian cyst, Torsion of the Testis, Volvulus of the intestines, Varicose Veins, Megacolon, Aortamegaly, Scoliosis, Erb's Palsy, Peyronie's Disease, Main-en-Griffe, Undescended Foot (Pes Cavus), Talipes, Strabismus. Spasm is “panenepidemic” and unclassified examples of Torsion Dystonia and Dyskinesia really are as common as debt and taxes.  相似文献   

14.
15.
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   

16.
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   

17.
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   

18.
Zusammenfassung Eine Reihe pathologischer Zustände bedingen Magnesiummangel. Zustände mit Hypermagnesämie sind ebenfalls bekannt, doch wesentlich seltener. Für den Kardiologen beachtenswert ist, daß unter Therapie mit bestimmten Diuretica bei Herzinsuffizienz, bei Herzinfarkt, Kardiomyopathie, Digitalisintoxikation und bestimmten Herzrhythmusstörungen Hypomagnesämie beobachtet wurde. Leider kann in der klinischen Routine nur ein extracelluläres Magnesiumdefizit durch Serumbestimmungen gemessen werden; über Magnesiummangel einzelner Organe kann nichts ausgesagt werden. Hinweise für Magnesiummangel geben aber neben der Messung des Serumspiegels Anamnese, klinischer Befund, bestimmte EKG-Veränderungen wie auch evtl. Hypokalämie, ein Zustand, bei dem sich oft — besonders bei Aldosteronismus — parallele Veränderungen zeigten.Tierexperimente deuten darauf hin, daß infarktähnliche Läsionen unter Magnesiummangel entstehen, doch ob Herzinfarkt beim Menschen durch Magnesiummangel ausgelöst werden kann, ist noch ungeklärt. In Leichenherzen zeigte sich im Infarktgebiet neben Calciumakkumulation signifikanter Magnesiumverlust, wobei unklar blieb, ob sich Ursache oder Folge des Infarktes widerspiegelten. Falls ein ursächlicher Zusammenhang besteht, ist er im Myokardstoffwechsel selbst zu suchen, wie bei der Alkoholkardiomyopathie, wo myokardialer Magnesiummangel zumindest als pathogenetischer Teilfaktor anerkannt wird. Andererseits versucht man aber auch Beziehungen zwischen Atherosklerose, Blutgerinnung und Hypomagnesämie herzustellen, in der Meinung, daß Magnesiummangel auch über den coronaren Pathomechanismus des Herzinfarktes wirken könnte. Sicher scheint, daß gewisse EKG-Veränderungen und Herzrhythmusstörungen durch einen irritierten Magnesiumhaushalt bedingt sein können, da sie bei Gabe bzw. Entzug von Magnesium verschwinden. Daß Magnesiummangel die Glykosidtoleranz verringert, wird tierexperimentell bestätigt. Unter Hypomagnesämie bewirkt Acetylstrophanthidin eher und länger Rhythmusstörungen als ohne, außerdem lassen diese sich durch Magnesiumgaben eliminieren. Da in gewissen Fällen spontane und digitalisinduzierte Herzrythmusstörungen durch Magnesiuminjektionen beseitigt wurden, scheint Magnesium als Therapeuticum angebracht. Einsatz verschiedener Magnesiumsalze bei Angina pectoris, degenerativen Herzerkrankungen und Herzinsuffizienz ohne geprüften und offensichtlich gestörten Magnesiumhaushalt ist fragwürdig, weil keine eindeutigen klinischen Erfolgsbeweise vorliegen. Immerhin mag es aber larvierte, durch Serumbestimmungen nicht erfaßbare Mangelzustände geben. Allgemein erscheint es aus kardiologischer Sicht ratsam, den Magnesiumhaushalt zu überwachen und in entsprechenden Fällen auszugleichen, um möglichen Myokardläsionen oder fatalen Herzrhythmusstörungen entgegenzuwirken.  相似文献   

19.
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   

20.
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.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号