Dissertation (Ph.D.)--University of South Florida, 2008. / Includes vita. Includes bibliographical references. Also available online.

Diss. (sammanfattning) Stockholm : Karol. inst., 2006. / Härtill 4 uppsatser.

Chiu, Wui Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 107-128). / Abstracts in English and Chinese. / Abstract --- p.i / 中文摘要 --- p.iv / Acknowledgements --- p.vi / Publications --- p.viii / Table of Contents --- p.ix / List of Tables --- p.xiv / List of Figures --- p.xv / List of Abbreviations --- p.xviii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Hypoxic-ischemic encephalopathy in human infants --- p.1 / Chapter 1.1.1 --- Incidence --- p.1 / Chapter 1.1.2 --- Biphasic development of HI brain damage --- p.2 / Chapter 1.1.2.1 --- Initiating mechanism: energy failure in immature brain --- p.3 / Chapter 1.1.2.2 --- Biochemical cascades --- p.4 / Chapter 1.1.2.2.1 --- Excitatory amino acid receptor activation by glutamate --- p.4 / Chapter 1.1.2.2.2 --- Intracellular calcium accumulation --- p.4 / Chapter 1.1.2.2.3 --- Formation of free radicals --- p.5 / Chapter 1.1.2.2.3.1 --- Reactive oxygen species (ROS) --- p.5 / Chapter 1.1.2.2.3.2 --- Nitric oxide (NO) --- p.6 / Chapter 1.1.2.3 --- Release of inflammatory mediators --- p.6 / Chapter 1.1.2.4 --- Mitochondrial dysfunction --- p.7 / Chapter 1.1.2.5 --- Final path to death: necrosis or apoptosis --- p.8 / Chapter 1.1.2.6 --- Ways to change: neuronal survival and proliferation signaling --- p.8 / Chapter 1.1.3 --- Interventions for neonatal hypoxia-ischemia --- p.9 / Chapter 1.2 --- Animal models mimicking hypoxia-ischemia brain injury --- p.12 / Chapter 1.2.1 --- Comparisons of animal models of hypoxia-ischemia --- p.12 / Chapter 1.2.2 --- Development of neonatal rat model with hypoxic-ischemic damage --- p.14 / Chapter 1.3 --- Neural stem/progenitor cells --- p.15 / Chapter 1.3.1 --- Effect of hypoxic-ischemia on neural stem/progenitor cells --- p.17 / Chapter 1.4 --- Thrombopoietin --- p.18 / Chapter Chapter 2 --- Objectives --- p.23 / Chapter Chapter 3 --- Materials and Methodology --- p.24 / Chapter 3.1 --- Establishment of neonatal rat model of HI brain damage and effects of TPO on neural protection --- p.24 / Chapter 3.1.1 --- Animal protocols --- p.24 / Chapter 3.1.2 --- Induction of HI brain damage in neonatal rats --- p.24 / Chapter 3.1.3 --- Treatment with TPO --- p.25 / Chapter 3.1.4 --- Sacrifice of rats --- p.25 / Chapter 3.1.5 --- Read-out measurements --- p.26 / Chapter 3.1.5.1 --- Brain weight --- p.26 / Chapter 3.1.5.2 --- Gross injury assessment of the right hemisphere --- p.26 / Chapter 3.1.5.3 --- Histology --- p.27 / Chapter 3.1.5.4 --- Blood cell count --- p.27 / Chapter 3.1.5.6 --- Functional assessments --- p.28 / Chapter 3.1.5.6.1 --- Grip traction test --- p.28 / Chapter 3.1.5.6.2 --- Elevated body swing test --- p.28 / Chapter 3.1.5.7 --- Statistical analysis --- p.28 / Chapter 3.2 --- Establishment of in vitro model of primary mouse NSPs and the effect of TPO on their proliferation --- p.29 / Chapter 3.2.1 --- Mouse embryo dissection for the extraction of NSP --- p.29 / Chapter 3.2.2 --- Culturing of NSP --- p.30 / Chapter 3.2.3 --- Immunofluorescence staining for stem cell markers --- p.31 / Chapter 3.2.4 --- Neurosphere assay with different combinations of mitogens --- p.31 / Chapter 3.2.5 --- Neurosphere assay with different concentrations of TPO --- p.32 / Chapter 3.2.6 --- Neurosphere assay under hypoxia --- p.32 / Chapter 3.2.7 --- Statistical analysis --- p.33 / Chapter Chapter 4 --- Effects of thrombopoietin on neonatal rat models of hypoxia-ischemia brain damage --- p.39 / Chapter 4.1 --- Summary of experimental settings --- p.39 / Chapter 4.2 --- Results --- p.39 / Chapter 4.2.1 --- Mortality --- p.39 / Chapter 4.2.2 --- Effects of TPO on p7 mild damage model 1 week post-surgery --- p.40 / Chapter 4.2.2.1 --- Body and brain weights --- p.40 / Chapter 4.2.2.2 --- Gross injury score --- p.41 / Chapter 4.2.2.3 --- Cortex and hippocampus area --- p.41 / Chapter 4.2.2.4 --- Blood cell counts --- p.42 / Chapter 4.2.3 --- Effects of TPO on p7 severe damage model 1 week post-surgery --- p.43 / Chapter 4.2.3.1 --- Body and brain weights --- p.43 / Chapter 4.2.3.2 --- Gross injury score --- p.43 / Chapter 4.2.3.3 --- Cortex area --- p.44 / Chapter 4.2.3.4 --- Blood cell counts --- p.44 / Chapter 4.2.4 --- Effects of TPO on p7 severe damage model 3 week post-surgery --- p.45 / Chapter 4.2.4.1 --- Body and brain weights --- p.45 / Chapter 4.2.4.2 --- Gross injury score --- p.46 / Chapter 4.2.4.3 --- Blood cell counts --- p.46 / Chapter 4.2.4.4 --- Functional outcomes --- p.46 / Chapter 4.2.5 --- Effects of TPO on pl4 severe damage model 1 week post-surgery --- p.47 / Chapter 4.2.5.1 --- Body and brain weights --- p.47 / Chapter 4.2.5.2 --- Gross injury score --- p.48 / Chapter 4.2.5.3 --- Cortex area --- p.48 / Chapter 4.2.5.4 --- Blood cell counts --- p.49 / Chapter 4.3 --- Discussion --- p.49 / Chapter Chapter 5 --- Effects of thrombopoietin on the proliferation of primary mouse neural stem/ progenitor cells in culture --- p.83 / Chapter 5.1 --- Summary of experimental settings --- p.83 / Chapter 5.2 --- Results --- p.83 / Chapter 5.2.1 --- Effect of EGF or bFGF withdrawal on NSP proliferation --- p.84 / Chapter 5.2.2 --- Dose effect of TPO treatment on NSP proliferation --- p.85 / Chapter 5.2.3 --- Effect of hypoxia --- p.85 / Chapter 5.2.4 --- Effect of TPO treatment in combination with hypoxia --- p.86 / Chapter 5.2.5 --- Detection of neural progenitor cell marker --- p.87 / Chapter 5.3 --- Discussion --- p.88 / Chapter Chapter 6 --- General discussion --- p.101 / Bibliography --- p.106

Dissertation (Ph.D.)--University of South Florida, 2008. / Includes vita. Includes bibliographical references. Also available online.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 8 uppsatser.

Neonatal hypoxic-ischemic encephalopathy (HIE) is a common clinical problem. Tanshinone IIA is a compound purified from the Chinese herb Danshen ( Radix Salviae Miltiorrhiza Bge). Thrombopoietin (TPO) and Erythropoietin (Epo) are hematopoietic growth factors. The effects of tanshinone IIA, EPO and TPO on hypoxia-ischemia brain injury were investigated in this study, using in vitro model of neural cell culture and an in vivo model of hypoxic-ischemic brain damage. / Our observation provided the first evidence showing the expression of functional TPO receptor c-mpl in central nervous system. It revealed that novel agents TPO, EPO and tanshinone IIA have neuroprotection effects against brain injury induced by hypoxia-ischemia in neonatal rats, and these agents could be developed for clinical applications. / To investigate the effect of TPO, EPO and tanshinone IIA on in-vivo neural protection, a neonatal rat model of hypoxic-ischemic brain damage was established. Our results demonstrated significant and sustained brain injury in the hypoxic-ischemic and vehicle-treated group, measured by the reduction in relative weights of the ipsilateral (right) to the contralateral (left) brain at 1 and 3 weeks post-surgery, compared with those of sham-operated animals. At 3 weeks post-surgery, the hypoxic-ischemic animals had decreased cortical neuron density quantified by neuron-specific enolase (NSE) staining, and compromised sensorimotor functions in response to the postural reflex test. Treatment with TPO, EPO and tanshinone IIA significantly reduced the severity of brain injury, as indicated by the significantly increased ipsilateral brain weight and neuron density. Recoveries of sensorimotor functions (p < 0.05) and histopathology were also observed in animals that received TPO, EPO and tanshinone IIA. The plasma of tanshinone IIA-treated animals exhibited higher antioxidant activities (oxygen radical absorbance capacity assay) than those from vehicle-treated rats. / TPO and TPO receptor (c-mpl) mRNA was identified in human cerebral hemispheres, cerebellum, mouse neural progenitor cell line C17.2 and four neuroblastoma cell lines (SK-N-MC, MHH-NB-11, SK-N-AS and SH-SY-5Y) using RT-PCR methods. TPO proteins were detected in human cerebrospinal fluid (CSF) and plasma by ELISA. Furthermore, TPO receptor c-mpl was confirmed in human cerebral hemispheres, hippocampus, cerebellum, brainstem and spinal cord using immunohistostaining. TPO had a stimulating effect on the growth of neural progenitor cell C17.2 in culture via the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway as demonstrated by Western blot. The anti-apoptotic effects of TPO, EPO on C17.2 cells were demonstrated by staining with Annexin-V and PI. EPO exerted a protective effect against SHSY-5Y cell damage induced by NMDA (N-methyl-d-aspartate), as demonstrated by the MTT and LDH assay. The anti-oxidative property of tanshinone IIA was studied in the C17.2 cell line. Tanshinone IIA increased the viability of these cells subjected to 2,2'-azobis (2-amidino propane hydrochloride) (AAPH)-induced oxidative stress. / by Xia Wen-Jie. / "May 2005." / Advisers: Kwok-Pui Fung, Tai-Fai Fok. / Source: Dissertation Abstracts International, Volume: 67-01, Section: B, page: 0126. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 126-146). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

INTRODUÇAO: O uso da epinefrina na ressuscitação cardiopulmonar (RCP) tem sido questionado devido aos efeitos adversos como dano miocárdico e cerebral. Fármacos como azul de metileno têm sido estudados como adjuvantes, objetivando reduzir essas lesões. OBJETIVOS: Neste estudo objetivou-se avaliar o efeito da administração do azul de metileno em bôlus durante a RCP, na lesão miocárdica e cerebral. MÉTODO: Quarenta e nove ratos Wistar machos submetidos a parada cardíaca por fibrilação ventricular foram distribuídos aleatoriamente em quatro grupos com 11 animais: azul de metileno (GA, 2mg/kg), solução salina (GC, salina 0,9% 0,1ml), epinefrina (GE, 20mcg/kg), epinefrina + azul de metileno (GM), além do grupo sham com 5 animais. A fibrilação ventricular foi induzida por estimulação elétrica direto no ventrículo direito por 3 minutos, sendo mantidos por mais 2 minutos em anóxia. As manobras de RCP foram iniciadas com o fármaco correspondente de cada grupo, massagem torácica, ventilação e desfibrilação. Após retorno a circulação espontânea (RCE), os animais foram observados durante quatro horas. Foram coletados sangue para gasometria e troponina, tecido cardíaco e cerebral para análise histológica, marcação de TUNEL, marcadores inflamatórios e de estresse oxidativo. Os grupos foram comparados por meio do teste não paramétrico de Kruskal-Wallis, com o teste de comparação múltipla com correção de Bonferroni quando adequado. RESULTADOS: Animais do grupo GE apresentaram 63% de RCE, enquanto o GC e GM obtiveram 40% e 45%, respectivamente, sem diferença estatística entre os grupos (p= 0,672). O grupo GA apresentou apenas 18% de RCE e foi excluído da análise. O tempo de RCP do GC foi maior comparado aos grupos GE e GM, mas sem diferença estatisticamente significativa. Os animais do grupo GM apresentaram PAM maior comparado ao grupo GC, no momento imediatamente após a RCE (P=0,007). Em todos os grupos os animais apresentaram acidose, queda da PaO2 e aumento do lactato após PCR e RCP. A mediana da troponina sérica foi maior no GC (130ng/ml) comparada ao grupo GE (3,8ng/ml), e GM (43,7ng/ml), porém sem diferença estatística. O grupo GC apresentou aumento significativo na expressão proteica dos marcadores BAX e TLR4. Não houve diferença estatística em relação a histologia e marcação de TUNEL entre os grupos submetidos a PCR. CONCLUSÃO: A utilização de azul de metileno em bolus na RCP de forma isolada apresentou resultados negativos em relação ao retorno da circulação espontânea. A utilização de azul de metileno associada a epinefrina não diminuiu a presença de lesões no cérebro e no coração decorrentes da parada cardíaca / INTRODUCTION: The use of epinephrine in cardiopulmonary resuscitation (CPR) has been questioned due to adverse effects such as myocardial and cerebral damage. Drugs such as methylene blue have been studied as adjuvants in order to reduce lesions. OBJECTIVES: The aim of this study was to evaluate the effect of methylene blue administration during CPR on myocardial and cerebral lesion. METHOD: Forty nine Wistar male rats submitted to ventricular fibrillation cardiac arrest (CA) were randomly assigned to four principal groups with 11 cases each one: methylene blue (MB, 2mg/kg), control (CTRL, 0.1ml saline 0.9%), epinephrine (EPI, 20?g/kg), epinephrine plus methylene blue (EPI+MB), and a sham group, wich have 5 cases. Ventricular fibrillation was induced by direct electrical stimulation in the right ventricle for 3 minutes and anoxia was maintained until a total of 5 minutes. CPR was initiated using the group drug, ventilation, chest compressions and defibrillation. The animals were observed for four hours after return of spontaneous circulation (ROSC). Blood samples were collected for blood gas and troponin measurements. Heart and brain tissues were harvested for the evaluation of oxidative stress, inflamation, histological and TUNEL staining. Groups were compared using the non-parametric Kruskal-Wallis test and Bonferroni post test. RESULTS: ROSC was achieved in 63% of the cases in EPI, 40% in CTRL, and 45% in EPI+MB (P=0.672). MB was excluded from analysis because of its low ROSC rate (18%). CPR duration was longer in CTRL compared to EPI and EPI+MB, without statistical significance. EPI+MB animals presented higher arterial pressure compared to the CTRL group, immediately after ROSC (P=0.007). All animals presented acidosis, decreased PaO2 and increased lactate after CA and CPR. Serum troponin was higher in CTRL (130ng/ml) compared with EPI (3.8ng/ml) and EPI+MB (43.7ng/ml), without statistical significance. CTRL presented higher BAX and TLR4 expression. There was no difference in TUNEL staining and histology among CA groups. CONCLUSION: Methylene blue in bolus during CPR did not improve outcome. Methylene blue combined with epinephrine did not decrease CA-related myocardial and cerebral lesions

Cerebral ischemia is the principal cause of morbidity and mortality worldwide. In addition to neuronal loss associated with hypoxic-ischemic damage, cerebral ischemia is characterized by a neuromicrovascular injury. Nitrative stress and lipid peroxidation increase in hypoxic-ischemic damages and play an essential role in neuromicrovascular injury leading to cerebral ischemia. We hypothesized that newly described lipid peroxidation products, termed trans-arachidonic acids (TAA), could be implicated in the pathogenesis of hypoxia-ischemia by affecting the cerebral vasomotricity and microvascular integrity. / The effects of TAA on neuromicrovascular tone were tested ex vivo by monitoring the changes in vascular diameter of rat cerebral pial microvessels. Four isomers of TAA, namely 5 E-AA, 8E-AA, IIE-AA and 14 E-AA induced an endothelium-dependent vasorelaxation. Possible mechanisms involved in TAA-induced vasorelaxation were thoroughly investigated. Collectively, data enclosed revealed that TAA induce cerebral vasorelaxation through the interactive activation of BKCa channels with heme oxygenase-2. This interaction leads to generation of carbon monoxide which in turn activates soluble guanylate cyclase and triggers vasorelaxation. / Chronic effects of TAA on microvascular integrity were examined by generating a unilateral hypoxic-ischemic (HI) model of cerebral ischemia on newborn rat pups. Our HI model showed microvascular degeneration as early as 24h post-HI, preceded by an increase in cerebral TAA levels. HI-induced microvascular lesions were dependent on nitric oxide synthase activation and ensued TAA formation. Although the molecular mechanisms leading to TAA-induced microvascular degeneration were, in part uncovered for the retina, the primary site of action of TAA remains unknown. We demonstrated that TAA binds and activates GPR40 receptor, a newly described free fatty acid receptor. Importantly, GPR40 receptor knock-out prevents TAA-induced reduction in cerebral microvascular density and limits HI-induced brain infarct.

INTRODUÇAO: O uso da epinefrina na ressuscitação cardiopulmonar (RCP) tem sido questionado devido aos efeitos adversos como dano miocárdico e cerebral. Fármacos como azul de metileno têm sido estudados como adjuvantes, objetivando reduzir essas lesões. OBJETIVOS: Neste estudo objetivou-se avaliar o efeito da administração do azul de metileno em bôlus durante a RCP, na lesão miocárdica e cerebral. MÉTODO: Quarenta e nove ratos Wistar machos submetidos a parada cardíaca por fibrilação ventricular foram distribuídos aleatoriamente em quatro grupos com 11 animais: azul de metileno (GA, 2mg/kg), solução salina (GC, salina 0,9% 0,1ml), epinefrina (GE, 20mcg/kg), epinefrina + azul de metileno (GM), além do grupo sham com 5 animais. A fibrilação ventricular foi induzida por estimulação elétrica direto no ventrículo direito por 3 minutos, sendo mantidos por mais 2 minutos em anóxia. As manobras de RCP foram iniciadas com o fármaco correspondente de cada grupo, massagem torácica, ventilação e desfibrilação. Após retorno a circulação espontânea (RCE), os animais foram observados durante quatro horas. Foram coletados sangue para gasometria e troponina, tecido cardíaco e cerebral para análise histológica, marcação de TUNEL, marcadores inflamatórios e de estresse oxidativo. Os grupos foram comparados por meio do teste não paramétrico de Kruskal-Wallis, com o teste de comparação múltipla com correção de Bonferroni quando adequado. RESULTADOS: Animais do grupo GE apresentaram 63% de RCE, enquanto o GC e GM obtiveram 40% e 45%, respectivamente, sem diferença estatística entre os grupos (p= 0,672). O grupo GA apresentou apenas 18% de RCE e foi excluído da análise. O tempo de RCP do GC foi maior comparado aos grupos GE e GM, mas sem diferença estatisticamente significativa. Os animais do grupo GM apresentaram PAM maior comparado ao grupo GC, no momento imediatamente após a RCE (P=0,007). Em todos os grupos os animais apresentaram acidose, queda da PaO2 e aumento do lactato após PCR e RCP. A mediana da troponina sérica foi maior no GC (130ng/ml) comparada ao grupo GE (3,8ng/ml), e GM (43,7ng/ml), porém sem diferença estatística. O grupo GC apresentou aumento significativo na expressão proteica dos marcadores BAX e TLR4. Não houve diferença estatística em relação a histologia e marcação de TUNEL entre os grupos submetidos a PCR. CONCLUSÃO: A utilização de azul de metileno em bolus na RCP de forma isolada apresentou resultados negativos em relação ao retorno da circulação espontânea. A utilização de azul de metileno associada a epinefrina não diminuiu a presença de lesões no cérebro e no coração decorrentes da parada cardíaca / INTRODUCTION: The use of epinephrine in cardiopulmonary resuscitation (CPR) has been questioned due to adverse effects such as myocardial and cerebral damage. Drugs such as methylene blue have been studied as adjuvants in order to reduce lesions. OBJECTIVES: The aim of this study was to evaluate the effect of methylene blue administration during CPR on myocardial and cerebral lesion. METHOD: Forty nine Wistar male rats submitted to ventricular fibrillation cardiac arrest (CA) were randomly assigned to four principal groups with 11 cases each one: methylene blue (MB, 2mg/kg), control (CTRL, 0.1ml saline 0.9%), epinephrine (EPI, 20?g/kg), epinephrine plus methylene blue (EPI+MB), and a sham group, wich have 5 cases. Ventricular fibrillation was induced by direct electrical stimulation in the right ventricle for 3 minutes and anoxia was maintained until a total of 5 minutes. CPR was initiated using the group drug, ventilation, chest compressions and defibrillation. The animals were observed for four hours after return of spontaneous circulation (ROSC). Blood samples were collected for blood gas and troponin measurements. Heart and brain tissues were harvested for the evaluation of oxidative stress, inflamation, histological and TUNEL staining. Groups were compared using the non-parametric Kruskal-Wallis test and Bonferroni post test. RESULTS: ROSC was achieved in 63% of the cases in EPI, 40% in CTRL, and 45% in EPI+MB (P=0.672). MB was excluded from analysis because of its low ROSC rate (18%). CPR duration was longer in CTRL compared to EPI and EPI+MB, without statistical significance. EPI+MB animals presented higher arterial pressure compared to the CTRL group, immediately after ROSC (P=0.007). All animals presented acidosis, decreased PaO2 and increased lactate after CA and CPR. Serum troponin was higher in CTRL (130ng/ml) compared with EPI (3.8ng/ml) and EPI+MB (43.7ng/ml), without statistical significance. CTRL presented higher BAX and TLR4 expression. There was no difference in TUNEL staining and histology among CA groups. CONCLUSION: Methylene blue in bolus during CPR did not improve outcome. Methylene blue combined with epinephrine did not decrease CA-related myocardial and cerebral lesions

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