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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Effects of environmental enrichment on ischemic tolerance /

Farrell, Rosemarie, January 2001 (has links)
Thesis (M.Sc.)--Memorial University of Newfoundland, 2002. / Bibliography: leaves 72-92.
12

Rehabilitative experience following focal ischemic brain injury : evidence for bihemispheric neural reorganization and the existence of a critical period for enhanced morphological plasticity and functional recovery /

Biernaskie, Jeffrey A., January 2003 (has links)
Thesis (Ph.D.)--Memorial University of Newfoundland, 2004. / Bibliography: leaves 140-153.
13

Alteration of protein pattern in the brain in experimentally induced cerebral ischemia.

January 1991 (has links)
by Mo Flora. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1991. / Includes bibliographical references (leaves 168-184). / ACKNOWLEDGEMENT --- p.i / ABSTRACT --- p.ii / TABLE OF CONTENTS --- p.iv / Chapter CHAPTER ONE --- INTRODUCTION / Chapter 1.1 --- Stroke as a major disabling disease --- p.1 / Chapter 1.2 --- Classification of stroke --- p.4 / Chapter 1.3 --- Risk factors attributing to stroke --- p.15 / Chapter 1.4 --- Experimental methods to induce cerebral ischemia --- p.19 / Chapter 1.4.1 --- The establishment of animal models for stroke --- p.21 / Chapter 1.4.2 --- Gerbil as a putative model --- p.25 / Chapter 1.5 --- Mechanisms of focal ischemia damage --- p.30 / Chapter 1.6 --- Potential biochemical markers for cerebral ischemia --- p.38 / Chapter 1.7 --- Aim of investigation --- p.48 / Chapter CHAPTER TWO --- MATERIALS AND METHODS / Chapter 2.1 --- Common chemicals --- p.49 / Chapter 2.2 --- Common bench solutions --- p.52 / Chapter 2.3 --- Animals / Chapter 2.3.1 --- Gerbils --- p.52 / Chapter 2.3.2 --- Rabbit --- p.53 / Chapter 2.4 --- Establishment of an animal model / Chapter 2.4.1 --- Surgical methods for common carotid artery (CCA) ligation --- p.54 / Chapter 2.5 --- Methods to determine stroke conditions of gerbils / Chapter 2.5.1 --- Ocular fundus examination --- p.56 / Chapter 2.5.2 --- Stroke index --- p.56 / Chapter 2.5.3 --- Inclined plane method --- p.59 / Chapter 2.6 --- Preparation of gerbil brain for subsequent analysis / Chapter 2.6.1 --- Preparation of gerbil brain slices --- p.61 / Chapter 2.6.2 --- "2,3,5-triphenytetrazolium chloride (TTC) for quantitative staining of brain slices" --- p.61 / Chapter 2.6.3 --- Preparation of normal and stroke gerbil brain extract --- p.62 / Chapter 2.7 --- Polyacrylamide gel electrophoresis (PAGE) using a discontinuous buffer system / Chapter 2.7.1 --- Stock reagents --- p.63 / Chapter 2.7.2 --- Separation gel preparation --- p.65 / Chapter 2.7.3 --- Stacking gel preparation --- p.66 / Chapter 2.7.4 --- Electrophoresis conditions --- p.67 / Chapter 2.7.5 --- Staining and destaining --- p.67 / Chapter 2.8 --- Two dimensional slab gel electrophoresis / Chapter 2.8.1 --- Equipment --- p.70 / Chapter 2.8.2 --- Chemical --- p.70 / Chapter 2.8.3 --- Procedure --- p.74 / Chapter 2.9 --- Production of rabbit polyclonal antibodies against isolated stroke protein / Chapter 2.9.1 --- Isolation of stroke protein band from SDS-PAGE slab gel --- p.78 / Chapter 2.9.2 --- Production of anti-stroke protein serum in rabbits --- p.79 / Chapter 2.10 --- Western blotting method / Chapter 2.10.1 --- Reagents --- p.80 / Chapter 2.10.2 --- Procedures --- p.81 / Chapter 2.11 --- Extraction of total cellular RNA by lithium chloride method / Chapter 2.11.1 --- Reagents --- p.83 / Chapter 2.11.2 --- Procedures --- p.84 / Chapter 2.11.3 --- Checking the purity of the extracted RNA --- p.85 / Chapter 2.12 --- Purification of mRNA / Chapter 2.12.1 --- Reagents --- p.85 / Chapter 2.12.2 --- Procedure --- p.86 / Chapter 2.13 --- Verification of purity of mRNA / Chapter 2.13.1 --- Reagents --- p.87 / Chapter 2.13.2 --- Procedure --- p.88 / Chapter 2.14 --- Translation of gerbil brain mRNA in reticulocyte lysates and analysis of its product by SDS PAGE / Chapter 2.14.1 --- Reagents --- p.89 / Chapter 2.14.2 --- Procedures --- p.89 / Chapter CHAPTER THREE --- ESTABLISHMENT OF AN ANIMAL STROKE MODEL / Chapter 3.1 --- Foreword --- p.92 / Chapter 3.2 --- Preliminary studies / Chapter 3.2.1 --- Introduction --- p.92 / Chapter 3.2.2 --- Results --- p.93 / Chapter 3.2.3 --- Discussion --- p.96 / Chapter 3.3 --- Survival rate analysis / Chapter 3.3.1 --- Introduction --- p.97 / Chapter 3.3.2 --- Result --- p.98 / Chapter 3.3.3 --- Discussion --- p.102 / Chapter 3.4 --- Neurologic signs of ischemia / Chapter 3.4.1 --- Introduction --- p.103 / Chapter 3.4.2 --- Result --- p.105 / Chapter 3.4.3 --- Discussion --- p.111 / Chapter 3.5 --- Ocular fundus examination / Chapter 3.5.1 --- Introduction --- p.112 / Chapter 3.5.2 --- Result --- p.114 / Chapter 3.5.3 --- Discussion --- p.116 / Chapter 3.6 --- Inclined plane method / Chapter 3.6.1 --- Introduction --- p.117 / Chapter 3.6.2 --- Result --- p.118 / Chapter 3.6.3 --- Discussion --- p.121 / Chapter 3.7 --- Histologic examination using TTC as staining agent / Chapter 3.7.1 --- Introduction --- p.122 / Chapter 3.7.2 --- Result --- p.124 / Chapter 3.7.3 --- Discussion --- p.129 / Chapter CHAPTER FOUR --- IDENTIFICATION OF ALTERED PROTEIN PATTERN IN THE - BRAINS OF STROKE GERBILS BY ELECTROPHORETIC METHODS / Chapter 4.1 --- Separation of soluble brain extracts by SDS-PAGE analysis / Chapter 4.1.1 --- Introduction --- p.130 / Chapter 4.1.2 --- Result --- p.132 / Chapter 4.1.3 --- Discussion --- p.140 / Chapter 4.2 --- Two dimensional electrophoretic analysis of soluble brain extracts from stroke gerbils / Chapter 4.2.1 --- Introduction --- p.142 / Chapter 4.2.2 --- Result --- p.143 / Chapter 4.2.3 --- Discussion --- p.148 / Chapter CHAPTER FIVE --- ISOLATION OF STROKE-ASSOCIATED PROTEIN FROM BRAINS OF STROKE GERBILS BY IMMUNOCHEMICAL METHOD / Chapter 5.1 --- Introduction --- p.149 / Chapter 5.2 --- Result --- p.151 / Chapter 5.3 --- Discussion --- p.153 / Chapter CHAPTER SIX --- DETECTION OF NEW PROTEIN TRANSLATED FROM MESSENGER RIBONUCLEIC ACID FROM BRAINS OF STROKE GERBIL / Chapter 6.1 --- Introduction / Chapter 6.1.1 --- Extraction of stroke gerbil brain messenger ribonucleic acid --- p.154 / Chapter 6.1.2 --- Translation of mRNA --- p.154 / Chapter 6.2 --- Results / Chapter 6.2.1 --- Yield of total cellular RNA --- p.157 / Chapter 6.2.2 --- Verification of purity of mRNA --- p.157 / Chapter 6.2.3 --- Autoradiographic patterns of translated proteins --- p.159 / Chapter 6.3 --- Discussion --- p.163 / Chapter CHAPTER SEVEN --- GENERAL DISCUSSION --- p.165 / BIBLIOGRAPHY --- p.168
14

Recovery from focal brain ischemia induced by extradural compression in diabetic and non-diabetic rats /

Moreira, Tiago J. T. Prazeres, January 2006 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.
15

Mechanism of ischemic stroke in patients with middle cerebral artery stenosis.

January 2002 (has links)
Gao Shan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 191-194). / Abstracts in English and Chinese. / Abstract in English --- p.i / Abstract in Chinese --- p.iii / Acknowledgement --- p.v / Introduction --- p.vi / Contents --- p.viii / List of tables --- p.xiv / List of figures --- p.xv / Chapter Chapter One --- Literature Review / Chapter 1.1 --- Middle Cerebral Artery (MCA) Stenos --- p.is / Chapter 1.1.1 --- Prevalence of atherosclerotic MCA stenosis --- p.2 / Chapter 1.1.2 --- Methods for diagnosis of MCA stenosis --- p.3 / Chapter 1.1.3 --- Possible mechanism and course of stroke with MCA stenosis --- p.4 / Chapter 1.1.4 --- Treatment and prevention of stroke in patients with MCA stenosis --- p.5 / Chapter 1.2 --- Microembolic Signal (MES) Detection / Chapter 1.2.1 --- Introduction --- p.9 / Chapter 1.2.2 --- Technology --- p.9 / Characteristics of MES / Factors that affect MES detection / Problems of technology / Chapter 1.2.3 --- Clinical application --- p.15 / MES originating from atherosclerotic carotid artery stenosis / MES detection in internal carotid endarterectomy (CEA) / MES detection in patients with MCA stenosis / Predicting value and application in therapeutic trial / References --- p.19 / Chapter Chapter Two --- General Methodology / Chapter 2.1 --- Transcranial Doppler (TCD) Diagnosis for Intracranial Artery Stenosis / Chapter 2.1.1 --- TCD spectrum and common parameters --- p.29 / Chapter 2.1.2 --- Emitting and receiving transducers --- p.29 / Chapter 2.1.3 --- Pulsitility index (PI) --- p.31 / Chapter 2.1.4 --- Insonation depth and flow direction --- p.31 / Chapter 2.1.5 --- Continuous wave (CW) and pulsed wave (PW) --- p.33 / Chapter 2.1.6 --- Normal intracranial arteries through temporal and suboccipital window --- p.33 / Chapter 2.1.7 --- Normal intracranial arteries through orbital window --- p.36 / Chapter 2.1.8 --- Normal extracranial arteries --- p.36 / Chapter 2.1.9 --- TCD diagnosis for intracranial artery stenosis --- p.39 / Chapter 2.1.10 --- Example of multiple intracranial arteries stenosis --- p.39 / Chapter 2.2 --- Microembolic Signal (MES) Detection / Chapter 2.2.1 --- Device of MES monitoring --- p.41 / Chapter 2.2.2 --- Insonated artery and depth --- p.41 / Chapter 2.2.3 --- Axis length of the sample volume --- p.43 / Chapter 2.2.4 --- Fast Fourier Transform (FFT) time window overlap --- p.43 / Chapter 2.2.5 --- Distinguishing embolic signal and artifact with two-gate transducer --- p.45 / Chapter 2.2.6 --- Measurements of embolic signal and threshold --- p.47 / References --- p.45 / Chapter Chapter Three --- Prevalence and Clinical Significance of Microembolic Signal (MES) in Patients with Middle Cerebral Artery (MCA) Stenosis / Chapter 3.1 --- Abstract --- p.50 / Chapter 3.2 --- Introduction --- p.51 / Chapter 3.3 --- Methodology --- p.51 / Patients / Severity of stroke and clinical course / Diagnosis for middle cerebral artery (MCA) stenosis / Microembolic signal (MES) detection / Statistical analysis / Chapter 3.4 --- Results --- p.55 / Baseline information of patients / Prevalence of MES / Relationship between presence of MES and severity of MCA stenosis / Correlation between presence of MES and clinical course in 85 symptomatic patients / Correlation between the count of MES and clinical course in 85 symptomatic patients / Correlation between the presence of MES and further ischemic stroke / Chapter 3.5 --- Discussion --- p.63 / Prevalence of MES / Association between severity of stroke and presence or the number of MES / Predictive value of MES for further stroke / References --- p.66 / Chapter Chapter Four --- Mechanisms of Acute Cerebral Infarction in Patients with Cerebral Artery Stenosis: a Diffusion-weighted Imaging and Microemboli Monitoring study / Chapter 4.1 --- Abstract / Chapter 4.2 --- Introduction --- p.72 / Chapter 4.3 --- Methodology --- p.73 / Patients / Microembolic signal (MES) detection by transcranial Doppler (TCD) / "Magnetic resonance imaging (DWI, MRI and MRA)" / Statistical analysis / Chapter 4.4 --- Results --- p.77 / Severity of MCA stenosis on MRA and pattern of infarct on DWI / Frequency and count of MES and its relationship with multiple and borderzone infarction on DWI / Chapter 4.5 --- Discussion --- p.79 / Frequency of MES / Pattern of cerebral infarcts on DWI / Relationship between MES and multiple infarcts on DWI / References --- p.83 / Chapter Chapter Five / Chapter Chapter Five-I --- Novel Observations of the Characteristics of Real Time Genesis of Thromboembolism in Middle Cerebral Artery Stenosis Detected by Transcranial Doppler / Chapter 5.1.1 --- Abstract --- p.90 / Chapter 5.1.2 --- Introduction --- p.91 / Chapter 5.1.3 --- Methodology --- p.91 / Characteristics of patients / "MRA, DWI and conventional TCD data" / MES monitoring method and overall data / Neuroimaging and MES monitoring data in all five patients / Signal analysis in off-line / Confirmation test for the origin of MES / Chapter 5.1.4 --- Results --- p.104 / Frequency of three special phenomena / Characteristics of three special phenomena / Results of confirmation test for embolic source / Chapter 5.1.5 --- Discussion --- p.133 / Occurrence of MES with flow velocity change simultaneously / MES splatter / Bi-directional low frequency (S-velocity) vibration / Testing for source of MES detected from MCA stenosis / References --- p.139 / Chapter Chapter Five-II --- Characteristics of Microembolic Signals Detected near Its Origin from the Middle Cerebral Artery Stenosis / Chapter 5.2.1 --- Abstract --- p.143 / Chapter 5.2.2 --- Introduction --- p.144 / Chapter 5.2.3 --- Methodology --- p.144 / Patients / Microembolic signal (MES) detection / Classification of MES / Chapter 5.2.4 --- Results --- p.145 / Types of MES detected from MCA stenosis / Characteristics of three types of MES / Chapter 5.2.5 --- Discussion --- p.157 / Emboli moving from vessel wall to the center / Emboli vibration / About calculating the time delay between two channels / References --- p.160 / Chapter Chapter Five-III --- "Hemodynamic change,microembolic signal counts and use of antithrombotic treatments" / Chapter 5.3.1 --- Abstract --- p.163 / Chapter 5.3.2 --- Introduction --- p.164 / Chapter 5.3.3 --- Methodology --- p.164 / Chapter 5.3.4 --- Results / "The relationship among flow velocity, the number of MES and time since symptom onset" --- p.165 / Patient one / Patient two / Patient three / Chapter 5.3.5 --- Discussion / Association between flow velocity or MES change and different anticoagulants in acute stage / Progression of MCA stenosis after acute stage / Stability of MCA atherosclerotic stenosis / References --- p.173 / Chapter Chapter Six --- The Optimal Values of Flow Velocity on Transcranial Dopplerin Grading Severity of Middle Cerebral Artery Stenosis in Comparison With Magnetic Resonance Angiography / Chapter 6.1 --- Abstract --- p.179 / Chapter 6.2 --- Introduction --- p.180 / Chapter 6.3 --- Methodology --- p.180 / Patients / TCD examination / Grading of MCA stenosis on MRA / Statistical analysis / Chapter 6.4 --- Results --- p.182 / Detection of >50% MCA stenosis according to flow velocity / Grading severity of MCA stenosis by flow velocity / Chapter 6.5 --- Discussion --- p.186 / Reliability of TCD diagnosis for MCA stenosis / Grading MCA stenosis according to flow velocity on TCD / References / Abbreviations --- p.189 / Publications --- p.191
16

The value of extracranial arterial blood flow volume in ischaemic cerebrovascular disease. / CUHK electronic theses & dissertations collection

January 2002 (has links)
Ho Sin Yee, Stella. / "August 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 167-193). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
17

Efeito neuroprotetor do α-bisabolol em camundongos submetidos à isquemia cerebral focal permanente / Neuroprotective effect α-bisabolol in mice submitted to ischemia model permanent focal cerebral

Mara Yone Soares Dias Fernandes 02 July 2015 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O acidente vascular cerebral (AVE) à uma das principais causa de mortalidade no Brasil, acometendo cerca de 200.000 indivÃduos anualmente. A fisiopatologia do AVE isquÃmico envolve uma complexa cascata de eventos como a inflamaÃÃo e o estresse oxidativo que podem à morte neuronal e dÃficits cognitivos. O α-bisabolol à um Ãlcool sesquiterpeno, monocÃclico, que ocorre na natureza e à encontrado como constituinte majoritÃrio do Ãleo essencial sintÃtico da Matricaria chamomilla, que possui atividade antiinflamatÃria, antioxidante e anti-apoptÃtica jà descritas. Para avaliar o efeito neuroprotetor deste composto em camundongos submetidos à oclusÃo permanente da artÃria cerebral media (pMCAO), os animais foram prà e pÃs tratados com α-bisabolol nas doses de 50, 100 e 200 mg/kg, v.o, durante 24, 48, 72, 96 ou 120 horas apÃs a isquemia. Os animais foram avaliados 24h apÃs a isquÃmia para verificar a Ãrea de lesÃo isquÃmica, avaliaÃÃo neurolÃgica e atividade da mieloperoxidase. 72 horas apÃs a pMCAO, os testes de atividade locomotora, memÃria de trabalho e memÃria aversiva recente foram realizados. 96 horas apÃs a pMCAO foi realizado o teste do reconhecimento de objecto, e os animais foram eutanasiados para a realizaÃÃo da Imunohistoquimica para TNF-α, iNOS e GFAP e anÃlise histologica para Cresil violeta e Fluoro Jade C. Finalmente, 120h apÃs a isquemia, avaliou-se a memÃria espacial. O α-bisabolol reduziu significativamente a lesÃo isquemica e o dÃficit neurolÃgico e normalizou a atividade locomotora. O α-bisabolol mostrou proteÃÃo contra os dÃficits nas memÃrias de trabalho, espacial, reconhecimento de objeto e aversiva. O α-bisabolol (200 mg/kg) preveniu significativamente o aumento da MPO e TNF-α no cÃrtex temporal e o aumento do iNOS tanto no cÃrtex temporal como no estriado. Tambem preveniu o aumento da astrogliose nessas Ãreas. O α-bisabolol (200 mg/kg) mostrou protecÃÃo contra a morte neuronal. Os resultados do presente estudo mostraram que o α-bisabolol possui atividade neuroprotetora provavelmente devido a sua aÃÃo antiinflamatÃria, mas outros mecanismos nÃo podem ser descartados. / Stroke is the leading cause of mortality in Brazil, affecting about 200,000 individuals annually. The pathophysiology of ischemic stroke involves a complex cascade of events such as inflammation and oxidative stress which will lead to neuronal death and cognitive deficits. The α-bisabolol is a sesquiterpene alcohol, natural, monocyclic, found as main constituents of the essential oil of Matricaria chamomilla, which has anti-inflammatory, antioxidant and anti-apoptotic already described. To evaluate the neuroprotective effects of this compound in mice underwent permanent occlusion of the middle cerebral artery (pMCAO), the animals were pre and post treated with α-bisabolol at doses of 50, 100 and 200 mg / kg, orally for 24, 48, 72, 96 or 120 hours after pMCAO. The animals were evaluated 24 hours after ischemia to verify the area of ischemic damage, and neurological evaluation and myeloperoxidase activity. Seventy-two hours after pMCAO, the locomotor activity tests, working memory and aversive recent memory were performed. Ninety six hours after the pMCAO was performed the object recognition test, and the animals were euthanized for carrying out the immunohistochemistry for TNF-α, iNOS and GFAP and for histology analyes Cresil violet and Fluoro Jade C. Finally, 120 h after pMCAO, the spatial memory was evaluated. The α-bisabolol reduced significantly ischemic damage and neurological deficit and normalized the locomotor activity. The α-bisabolol showed protection against the deficits in working, spatial, object recognition and aversive memories. The α-bisabolol (200 mg / kg) significantly prevented the increase of MPO and TNF-α in the temporal cortex and the increased of iNOS both in the temporal cortex and in striatum. Also prevented the increase in astrogliosis in there area. The α-bisabolol (200 mg / kg) showed protection against neuronal death. The results of this study showed that α-bisabolol has neuroprotective activity probably due to its anti-inflammatory action, but other mechanisms can not be discarded.
18

Actions of protease activated receptors in in vivo and in vitro models of stroke / CUHK electronic theses & dissertations collection

January 2014 (has links)
Ischaemic stroke has become one of the leading causes of death and disability in the world. Protease activated receptors (PARs, PAR-1 to PAR-4) belong to G protein coupled receptors that can be self-activated by tethered ligands (TL) revealed through proteolytic cleavage. Based on these TL, many activating peptides (APs) and antagonists have been synthesized to investigate PARs actions. / In the present study, the roles of PARs were examined in two models of ischaemic stroke. For the in vivo model, transient middle cerebral artery occlusion (tMCAO) was performed to establish cerebral ischaemia in rats. For the in vitro model, oxygen and glucose deprivation (OGD) was used to mimic an ischaemia insult in primary cultured rat embryonic cortical neurones. / Western blot studies showed that expressions of PAR-1 and PAR-2 were increased in the rat ischaemic brain cortex, whereas PAR-1 was reduced in the rat cortical neurones subjected to OGD. Pretreatments of PAR-1 AP (SFLLRN-NH₂) and PAR-2 AP (SLIGRL-NH₂) produced significant protection against ischaemia-induced damage. Pretreatment of PAR-3 AP (SFNGGP-NH₂) only improved ischaemic symptoms in in vivo but not in in vitro model. When treated after ischaemia, only PAR-1 AP produced significant reductions on ischaemia-induced damage. Protective actions of PAR-1 and PAR-2 APs were inhibited by PAR-1 antagonist (BMS-200261) and PAR-2 antagonist (ENMD-1068) respectively, but PAR-1 antagonist did not affect posttreatment effects of PAR-1 AP in in vitro model. Pre- and posttreatments of thrombin, and pretreatment of trypsin also protected ischaemia-induced damage in the two models. / PAR-1 AP produced marked increase in the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and ratio of bcl-2/bax, but reduced contents of reactive oxygen species (ROS), nitric oxide (NO) and malondialdehyde (MDA) in both ipsilateral ischaemic brain cortices and in rat cortical neurones subjected to OGD. In the in vitro model, PAR-1 AP greatly decreased caspase-3 activity and TUNEL positive cells, while markedly increased mitochondrial membrane potential (MMP). All these protective actions were inhibited by its antagonist, which suggests it was mediated via activation of PAR-1. / In MCA isolated from normal and ischameic rats, PAR-2 AP and trypsin produced vasodilatation while PAR-3 AP elicited vasoconstriction. However, another PAR-3 AP had no effect in the two types of MCA. A high concentration of PAR-1 AP relaxed MCA isolated form ischaemic rats, and it was not inhibited by a PAR-1 antagonist. The vasodilator action of PAR-2 AP was inhibited by one of two PAR-2 antagonists tested. The vasodilator actions induced by PAR-1 and PAR-2 APs involved NO production since L-NAME was effective in inhibiting their actions. / In conclusion, PAR-1 AP was found to be the most efficacious in protecting the brain from ischaemia-induced damage when administered either before or after ischaemia insults. The protective actions were likely to be attributed to its anti-oxidant properties in the ischaemic brain that reduced apoptosis of brain cells. Therefore, PAR-1 was identified as a promising target for development of novel prophylactic and therapeutic treatments of ischaemic brain disease. / 缺血性腦中風已經成為全世界導致死亡和殘疾的最主要的疾病之一。蛋白酶激活受體(PARs, PAR-1 to PAR-4)屬於G蛋白偶聯受體並且可以通過蛋白水解生成系鎖配體(TL)從而作用於受體本身而激活信號通路。根據TL的序列已經合成了很多激活肽和拮抗劑,它們可以作為有價值的工具藥進行PAR的作用研究。 / 當前,PAR的作用在兩個缺血性腦中風模型中進行研究。體內模型是通過大鼠大腦中動脈阻塞手術而建立;體外模型是通過對大鼠胚胎大腦皮層神經元進行氧糖剝奪模擬缺血性損傷。 / 蛋白質印跡法的實驗表明PAR-1和PAR-2的表達在缺血側大腦皮層中有所增多,而PAR-1在氧糖剝奪的大鼠皮層神經元中表達卻有所降低。預處理PAR-1(SFLLRN-NH₂)和PAR-2(SLIGRL-NH₂)的激活肽顯著改善了缺血導致的損傷。預處理PAR-3激活肽(SFNGGP-NH₂)僅僅改善了體內缺血症狀,卻對體外缺血模型沒有效果。然而,當這些激活肽在缺血后給予的時候,只有PAR-1的激活肽顯著改善了缺血損傷。PAR-1的拮抗劑(BMS-200261)和PAR-2的拮抗劑(ENMD-1068)抑制了PAR-1和PAR-2激活肽的保護作用,但是體外實驗後處理PAR-1激活肽的保護作用卻未收影響。預處理及後處理凝血酶,預處理胰酶都在這兩個模型中顯示出保護缺血性損傷的作用。 / PAR-1激活肽在缺血同側大腦皮層以及經受氧糖剝奪的大鼠皮層神經元中,顯著提高了超氧化物歧化酶(SOD)、過氧化氫酶(CAT)、谷胱甘肽過氧化物酶(GSH-Px)的活力以及bcl-2/bax的比例,同時顯著降低了活性氧自由基(ROS)、一氧化氮(NO)以及丙二醛(MDA)的含量。在體外模型中,PAR-1激活肽還顯著降低了caspase-3的活力以及TUNEL陽性細胞的比例,同時顯著提高了線粒體膜電位(MMP)。所有這些作用都可以被拮抗劑抑制,說明PAR-1激活肽的保護作用是通過激活PAR-1介導的。 / 不管是從正常還是缺血的大鼠中分離出來的大腦中動脈,PAR-2激活肽和胰酶都可以使之舒張,PAR-3激活肽卻對其有收縮作用。然而,另外一種PAR-3激活肽卻未顯現出對血管活性的影響。高劑量的PAR-1激活肽只可以在分離于缺血大鼠的大腦中動脈中引起舒張,但此作用不能被其拮抗劑所抑制。PAR-2激活肽導致的血管舒張只可以被檢測的兩個拮抗劑中的其中一個所抑制。PAR-1和PAR-2激活肽引起的血管舒張與NO的產生有關,因為L-NAME可以有效抑制它們的作用。 / 總之,不管是預處理還是後處理的給藥方式,PAR-1的激活肽在保護大腦的缺血性損傷中都是最有效果的。保護作用可能可以歸因于其抗氧化以及抗凋亡的特性。所以,PAR-1是研究防治缺血性腦疾病的發展中富有希望的一個靶點。 / Zhen, Xia. / Thesis Ph.D. Chinese University of Hong Kong 2014. / Includes bibliographical references (leaves 194-206). / Abstracts also in Chinese. / Title from PDF title page (viewed on 11, October, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.
19

The role of oxygen free radicals in ischemic brain damage

Pahlmark, Kerstin. January 1995 (has links)
Thesis (doctoral)--Lund University, 1995. / Added t.p. with thesis statement inserted.
20

Ischemic brain damage the influence of hyperglycemia on tissue injury, cerebral circulation and edema formation /

Gisselsson, Lars. January 1998 (has links)
Thesis (doctoral)--Lund University, 1998. / Added t.p. with thesis statement inserted. Includes bibliographical references.

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