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1.
目的:探讨大鼠局灶性脑缺血再灌注后大脑皮层神经细胞一氧化氮合酶(NOS)的表达与神经细胞凋亡的关系及中药复方丹参的保护作用.方法:采用大脑中动脉内栓线法造模,应用原位细胞凋亡检测方法观察神经细胞凋亡,用免疫组织化学方法检测大鼠大脑皮层神经细胞nNOS、iNOS的表达并做图像分析.结果:与假手术组比较,脑缺血冉灌注2 h后缺血侧大脑皮层缺血边缘区神经细胞nNOS、iNOS表达升高,并出现神经细胞凋亡,随着再灌注时间的延长,缺血侧大脑皮层缺血边缘区神经细胞iNOS表达明显增强,凋亡神经细胞数逐渐增多,至24 h达高峰,但神经细胞nNOS的表达增强不如iNOS表达明显.复方丹参保护组神经细胞nNOS、iNOS的表达和凋亡神经细胞数明显低于缺血再灌组.结论:脑缺血再灌注后缺血侧大脑皮层缺血边缘区神经细胞nNOS的表达增强,尤其是iNOS的表达显著升高,使NO产生增加可能是介导脑缺血再灌注后神经细胞凋亡的机制之一,复方丹参具有下调神经细胞nNOS、iNOS表达,减少NO生成,抑制细胞凋亡,减轻缺血再灌注对大鼠大脑皮层神经细胞损伤的作用.  相似文献   

2.
目的 探讨一氧化氮合酶(NOS)抑制剂左旋硝基精氨酸甲酯(L-NAME)对沙土鼠脑缺血再灌注后海马区胶质纤维酸性蛋白(GFAP)合成的影响。方法 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,观察GFAP密度的变化及分布。结果 脑缺血再灌流后海马区GFAP合成增加,GFAP阳性细胞主要分布在放射层及分子层,L-NAME能减少海马区GFAP的合成。结论 L-NAME是NOS强有力的抑制剂,L-NAME可能通过抑制NO的产生抑制了GFAP的合成。  相似文献   

3.
目的研究脑缺血区周边组织一氧化氮合酶(NOS)的表达与应激活化蛋白激酶/c—Jun氨基末端激酶(SAPK/JNK)及p38MAP激酶(p38MAPK)激活的关系;探讨一氧化氮(NO)诱导脑缺血再灌注后神经元凋亡的可能机制。方法采用TUNEL染色法观察脑缺血再灌注不同时段模型鼠缺血区周边组织凋亡的阳性神经元数量;免疫组织化学、蛋白免疫印迹方法检测活化型Caspase-3、神经元型一氧化氮合酶(nNOS)、诱导型一氧化氮合酶(iNOS)和SAPK/JNK,p38MAPK及其磷酸化组分的表达。结果再灌注后1h、2h缺血区周边组织nNOS表达明显增强;自1h起iNOS开始表达,12h达到高峰。1hp-SAPK/JNK表达较强,以后逐渐减弱;p38MAPK各时段表达均明显增强,以6h为著,p-p38MAPK表达高峰亦在6h。6h活化型Caspase.3开始表达,12h达到高峰;12h开始出现TUNEL阳性神经元,24h达到高峰。结论缺血区周边组织NOS表达的增强可能通过激活SAPK/JNK及p38MAPK诱导脑缺血再灌注后神经元凋亡。  相似文献   

4.
一氧化氮,一氧化氮合酶与脑缺血损伤   总被引:16,自引:0,他引:16  
在脑缺血损伤的不同阶段,不同类型的一氧化氮合酶(NOS)通过其催化生成的一氧化氮(NO)发挥不同的功能。在脑缺血早期,eNOS介导短时保护性作用,而nNOS则介导神经毒性效应并很快占据优势,使脑缺血损伤进展;至晚期,iNOS表达并介导毒性作用,使缺血生成的NO分别在脑缺血进展期和晚期介导神经毒性作用。这种机制为脑缺血损伤的治疗提供了新途径。  相似文献   

5.
目的观察八肽胆囊收缩素(CCK-8)对大鼠糖尿病性白内障(DC)的影响。方法用链脲霉素(STZ)复制大鼠DC模型。实验分为对照组、STZ组和治疗组。分别于实验第20、40和60天时检测晶状体iNOS mRNA与蛋白表达,一氧化氮(NO)含量与一氧化氮合酶(NOS)活性变化及组织学改变。结果对照组晶状体iNOS mRNA与蛋白未见明显表达,NO含量较少,NOS活性较低,晶状体上皮细胞(LEC)形态正常;STZ组iNOS mRNA和蛋白表达明显上调,NO生成增加,NOS活性增强,LEC病变随时间延长而加重。治疗组上述改变明显减轻。结论CCK-8可减轻晶状体损伤,机制可能与抑制iNOS基因表达、减少NO生成有关。  相似文献   

6.
目的: 研究人参皂苷Rg1对大鼠脑缺血再灌注损伤的影响及其作用的机制。方法: 采用大鼠右侧大脑中动脉阻塞(MCAO)2 h、再灌注24 h模型,造模前,人参皂甙Rg1防治组分别静脉注射人参皂苷Rg1 10、20及40 mg/kg,1次/d,连续7 d。分别以Longa's法评定神经功能、尼氏染色观察海马椎体细胞存活数,并检测脑组织中内一氧化氮(NO)含量及一氧化氮合酶(NOS)、诱导型一氧化氮合酶(iNOS)活性,Western blotting检测脑组织中神经元型一氧化氮合酶(nNOS)和iNOS蛋白表达。结果: 与模型组比较,人参皂苷Rg1 20及40 mg/kg组能明显改善大鼠MCAO后神经功能症状,增加海马椎体细胞存活数(P<0.05,P<0.01),使脑组织NOS和iNOS活性降低,NO生成减少(P<0.05,P<0.01),iNOS及nNOS表达不同程度降低(P<0.05,P<0.01)。结论: 人参皂苷Rg1能减轻大鼠脑缺血再灌注损伤,其机制可能与抑制NOS表达而使NO含量降低有关。  相似文献   

7.
目的:探讨大鼠局灶性脑缺血再灌流后神经细胞凋亡及其与caspase-3和caspase-9基因表达的关系。方法:应用原位末端标记和原位杂交技术分别观察细胞凋亡与caspase-3mRNA和caspase-9mRNA表达。结果:脑缺血再灌流后,凋亡神经细胞主要分布于缺血半影区,随着时间的延长凋亡细胞数逐渐增加,至24h达高峰。在缺血半影区,再灌流后神经细胞caspase-3mRNA和caspase-9mRNA表达逐渐增强,到24h阳性细胞数目最多,COD值最高,而缺血中心区两基因均弱表达。结论:脑缺血再灌流后神经细胞凋亡是一个动态的渐进过程。caspase-3和caspase-9基因表达在介导细胞凋亡过程中起重要作用。  相似文献   

8.
一氧化氮与缺血性脑血管疾病   总被引:5,自引:0,他引:5  
在脑缺血性损伤过程中,一氧化氮(n itric oxide,NO)发挥着复杂的作用,多途径参与生理和其病理过程。NO在脑缺血过程中起着保护与损伤双重作用,其对脑组织的损伤或保护取决于脑缺血的不同时期和一氧化氮合酶(n itric oxide synthase,NOS)的同工酶类型等因素。脑缺血早期内皮细胞型一氧化氮合酶(endothelial NOS,eNOS)催化生成的NO对脑缺血有防护作用,而在脑缺血缺氧的大部分时期由诱生型一氧化氮合酶(induc ib leNOS,iNOS)和神经元型一氧化氮合酶(neuronal NOS,nNOS)催化生成的一氧化氮对脑缺血则具有损伤作用。  相似文献   

9.
目的:观察局部亚低温对大鼠全脑缺血再灌注小脑皮层神经细胞凋亡的影响.方法:采用闭塞大鼠四动脉建立全脑缺血模型,应用电镜及末端转移酶介导的缺口末端标记法(TUNEL染色法)观察常温组和亚低温组动物脑缺血30min再灌注7d小脑皮层神经细胞的凋亡情况.结果:常温组小脑皮层神经细胞电镜显示有明显形态学损伤,染色质凝聚、边集、电子密度增强,核呈新月形或不规则状,细胞体积变小,胞浆浓缩.TUNEL染色法示蒲肯野细胞凋亡明显,凋亡率为(43.08±11.27)%.亚低温组神经细胞结构损伤明显减轻,凋亡细胞明显减少,凋亡率为(11.56±3.72)%.两组有统计学显著性差异.结论:亚低温对大鼠全脑缺血再灌注小脑皮层神经细胞凋亡有明显的抑制作用.  相似文献   

10.
为了探讨中药复方丹参对大鼠局灶性脑缺血再灌注后大脑皮层神经细胞凋亡及Bcl-2mRNA表达的影响和保护作用,本研究采用大脑中动脉内栓线阻断法(MCAO)造成局灶性脑缺血再灌注模型,应用原位末端标记(TUNEL)和原位杂交技术检测大鼠大脑皮层神经细胞凋亡和神经细胞Bcl-2mRNA的表达,并进行图像分析。结果显示:缺血再灌注组凋亡神经细胞主要位于缺血侧大脑皮层缺血边缘区(半暗区);缺血侧大脑皮层缺血边缘区神经细胞Bcl-2mRNA的表达在缺血再灌注2h后升高,随着缺血再灌注时间的延长逐渐增强;复方丹参保护组神经细胞Bcl-2mRNA的表达明显强于缺血再灌组(P<0.01),凋亡神经细胞数明显低于缺血再灌组(P<0.01)。上述结果说明复方丹参可通过上调神经细胞Bcl-2mRNA的表达,抑制神经细胞凋亡,减轻缺血再灌注对大鼠大脑皮层神经细胞的损伤。  相似文献   

11.
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   

12.
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   

13.
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   

14.
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.  相似文献   

15.
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.
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.
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   

19.
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   

20.
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   

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