Cardiac arrest is a common cause of coma with frequent poor outcomes. Palliative medicine teams are often called upon to discuss the scope of treatment and future care in cases of anoxic brain injury. Understanding prognostic tools in this setting would help medical teams communicate more effectively with patients’ families and caregivers and may promote improved quality of life overall. This article reviews multiple tools that are useful in determining outcomes in the setting of postarrest anoxic brain injury.

This study concerned the effect of ethanol on cardiac activity and brain respiration in chick embryos. Ethanol dosages tested ranged from 1.0 mg to 4.0 mg/g weight. Each experiment lasted at least 150 minutes. Cardiac activity in terms of total waveform energies was integrated and printed out for plotting and analysis. The embryonic heart rates were simultaneously determined from physical graph tracings. The embryonic brain respiration was measured using a differential microrespirometer. The effect of ethanol on cardiac activity was one of slight (10 to 13), but statistically significant (p<.05) rate depression. The brain slices exhibited a marked, immediate, and irreversible decrease (39 to 89%) in oxygen consumption at both ethanol dosages. The data indicated that chick embryonic brain tissues were more susceptible to alcohol effects than cardiac tissue. Therefore, the mental abnormalities seen in the offspring of alcoholic mothers may be more cerebral in nature than cardiovascular.

published_or_final_version / Paediatrics and Adolescent Medicine / Doctoral / Doctor of Philosophy

No description available.

A anóxia neonatal é uma das causas mais importantes de lesão encefálica em neonatos. Várias espécies de mamíferos têm contribuído no estudo dos mecanismos patogênicos envolvidos no prejuízo da anóxia/hipóxia, em particular roedores tem sido utilizado com sucesso como modelo da anóxia em humanos. Fatores como a maturidade do encéfalo no momento da deficiência de oxigênio, a duração da asfixia, vulnerabilidade regional e celular específica, apresentam grande influência no surgimento de problemas neurológicos, déficit sensoriomotor, prejuízo no aprendizado e memória. Alterações em processos atentivos e ansiedade também podem afetar as funções cognitivas. Em roedores, tem-se observado marcada hiperatividade na idade infantil, acompanhada por significativa hipoatividade na idade adulta. Os objetivos deste estudo foram avaliar as possíveis alterações comportamentais, tais como memória de referência espacial, memória operacional, alterações sensoriais, ansiedade e aquisição do medo condicionado ao som e ao contexto, em ratos, submetidos à anóxia neonatal. Foram utilizados 25 ratos albinos (Rattus norvegicus, linhagem Wistar) machos, neonatos, divididos em dois grupos experimentais: Anóxia (n = 13) e Controle (n = 12). Nos testes envolvendo a memória de referência espacial e memória operacional, o grupo experimental evidenciou que a anóxia neonatal causa prejuízo na capacidade de aprendizagem e navegação espacial no labirinto aquático de Morris, porém verificou-se que ambos os grupos conseguiram valer-se das suas experiências prévias para melhorarem seu desempenho na medida em que passavam pelos diferentes testes (memória de referência espacial, memória operacional com intervalo entre as tentativas de 10, 30 e 0) demonstrados por meio da diminuição na latência e no comprimento do trajeto, sendo esta melhora no desempenho inferior nos animais anóxia. Os animais anóxia, também necessitaram de mais dias de testes, para atingirem desempenho próximo ao encontrado nos animais do outro grupo. Observou-se variação na velocidade do nado ao longo dos dias de testes em ambos os grupos, porém verificou-se que os animais anóxia demonstraram velocidade inferior aos animais controle. No teste do labirinto em cruz elevado os animais anóxia mostraram-se menos ansiosos, tendo permanecido menor tempo em congelamento no teste do medo condicionado ao contexto, porém não ao som. Portanto, estes dados indicam que o modelo de anóxia neonatal utilizado promove alterações neuronais que modificam o comportamento do animal na vida adulta, verificados por meio das alterações comportamentais. Espera-se, com estes resultados, favorecer a compreensão das alterações comportamentais após anóxia neonatal e se possível, abrir caminho para novas abordagens e perspectivas terapêuticas / Neonatal anoxia is a major cause of brain injury in newborns. Several species of mammals have contributed to the study of pathogenic mechanisms involved in the injury caused by anoxia / hypoxia; particularly rodents have been used successfully as a model for the study of anoxia in humans. Factors such as maturity of the brain when oxygen deficiency, the duration of asphyxia, specific regional and cell vulnerability, have great influence on the rise of neurological disorders, sensory motor deficit, and impaired learning and memory. Changes in attentional processes and anxiety can also affect cognitive functions. In rodents, there has been marked hyperactivity at young age, accompanied by a significant hypoactivity in adult life. The objectives of this study were to evaluate the possible behavioral changes, such as spatial reference memory, working memory, sensory disturbance, anxiety and acquisition of conditioned fear to the sound and context in rats subjected to neonatal anoxia. We used 25 albino rats (Rattus norvegicus, Wistar) male neonates, divided into two groups: Anoxia (n = 13) and control (n = 12). In tests involving spatial reference memory and working memory, the experimental group showed that neonatal hypoxia adversely affects the ability of spatial learning and navigation in the Morris water maze, but it was found that both groups were able to draw on their experiences prior to improve its performance as they passed through various tests (spatial reference memory, working memory at an interval timing between attempts of 10, 30 and 0) shown by the decrease in latency and path length, and this improvement in underperform on anoxic animals. Anoxic animals also required more days of testing to achieve performance close to that found in animals of the other group. There was variation in the speed of swimming during the days of testing in both groups, but it was found that the anoxic animals showed lower speed than the control animals. In the elevated plus-maze test, the anoxic animals were less anxious and reminded less time freezing in the conditioned fear test to the context but not to the sound. Therefore, these data indicate that the used neonatal anoxia model promotes neuronal alterations that modify the behavior of the animal in adult life, verified through behavioral changes. It is expected, with these results, to promote understanding of the behavioral alterations after neonatal anoxia and, if possible, to make way for new approaches and therapeutic perspectives

Drosophila melanogaster tolerates several hours of anoxia (the absence of oxygen) by entering a protective coma. A burst of reactive oxygen species (ROS) is produced when oxygen is reintroduced to the cells. ROS causes oxidative damage to critical cellular molecules, which contribute to aging and development of certain agerelated conditions. The amino acid, methionine, is susceptible to oxidation, although this damage can be reversed by methionine sulfoxide reductases (Msr). This project investigates the effect of Msr-deficiency on anoxia tolerance in Drosophila throughout the lifespan of the animal. The data show that the time for recovery from the protective comma as well as the survival of the animals lacking any Msr activity depends on how quickly the coma is induced by the anoxic conditions. Insight into the roles(s) of Msr genes under anoxic stress can lead us to a path of designing therapeutic drugs around these genes in relation to stroke. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Glicose e oxigênio desempenham um importante papel na regulação do metabolismo celular. Dada a importância de ambos no metabolismo - o primeiro como fonte de carbono preferencial da maior parte das células, e o segundo como aceptor final de elétrons na cadeia respiratória, em diversos organismos desenvolveram-se métodos adequados para detectar sua presença de modo a ajustar o metabolismo em função de sua disponibilidade. Neste trabalho foi realizado o estudo da expressão, no nível transcricional, dos genes envolvidos nas vias metabólicas primárias e genes envolvidos em morte celular, em células humanas, com o intuito de determinar as alterações no metabolismo energético em resposta a condições de hipóxia e anóxia, por meio da técnica de microarrays de cDNA. Utilizamos, inicialmente, células normais de fibroblasto humano ASl98 e células de fibroblasto humano MRC-5 imortalizadas por transfecção por SV40, e por fim células provenientes de ilhotas pancreáticas humanas, para a elaboração de um protocolo de cultura celular em que as mesmas crescessem aderidas a microcarregadores Cytodex I. Numa segunda etapa, células de ilhotas pancreáticas humanas foram cultivadas em suspensão, aderidas aos microcarregadores, num biorreator, sendo então realizada a análise do perfil transcricional dos genes escolhidos, frente às condições de baixa tensão de oxigênio. É apresentada a análise da expressão gênica de aproximadamente 160 genes na qual foram verificados um comportamento de indução daqueles envolvidos no metabolismo de lipídios e alguns na morte celular e um comportamento inicial de indução, e posterior inibição, do metabolismo primário como um todo. Em vista dos dados obtidos é de interesse ressaltar que essas células deveriam ser mantidas em saturações de oxigênio acima de 5% para evitar o efeito deletério observado na baixa concentração de oxigênio sobre a viabilidade celular, em termos da indução de alguns genes envolvidos na morte celular e da repressão geral dos relacionados ao metabolismo energético. Também foi verificado que, em saturações de oxigênio de até 10%, as células adotaram um padrão transcricional que indicou uma resposta ao estresse por falta de oxigênio, este por sua vez reflete-se na viabilidade celular, característica crucial para o sucesso do transplante clínico de ilhotas. / Glucose and oxygen have important roles on the regulation of cellular metabolism. Due to their importance in metabolism, the former as the preferential carbon source and the later as the final electron acceptor of the respiratory chain, many organisms have developed suitable processes to detect their presence in order to adjust the cellular metabolism to their availability. In this work, we have studied, in human cells and at the transcriptional level, the expression of genes involved in primary metabolism pathways and some of those related to cell death, aiming to resolve alterations in the energetic metabolism as a response to hypoxic and anoxic conditions, by means of cDNA microarrays. We initially used AS198 human fibroblastic normal cells and MRC-5 human fibroblastic cells immortalized by SV40, and later on cells from human pancreatic islets, to develop a cell culture protocol in which they would grow on the surface of Cytodex 1 microcarriers. As a second step, cells from human pancreatic islets were cultured on microcarriers in suspension inside a bioreactor. This culture was then used to carry out the transcriptional profile analysis of selected genes in response to low levels of oxygen. This work presents the analysis of gene expression of approximately 160 genes that can be divided into two distinct groups. The first group, the expression of which is induced, comprises genes involved in lipid metabolism and some of those related to cell death. The expression of the second group, consisting of diverse genes of the primary metabolism, suffers an initial induction followed by repression. Given the data acquired it is interesting to note that the human pancreatic islets should be maintained under at least 5% dissolved oxygen to avoid the deleterious effects on cell viability observed at lower oxygen concentrations, resulting in the induction of some genes involved in cell death and the repression of those related to energetic metabolism. It was also verified that, under oxygen saturation of at least 10%, these cells adopted a transcriptional profile that indicated a response to the stress created by the lack of oxygen, which would in turn reflect on cell viability, a crucial characteristic for success in clinical islet transplantation.

Com objetivos de validar o modelo de anóxia neonatal apresentado e analisar a distribuição de neurônios imunorreativos à proteína Fos (IR-Fos) no encéfalo de ratos neonatos submetidos ao insulto anóxico, foram utilizados 24 ratos wistar neonatos machos divididos em dois grupos: Anóxia (n=12) e Controle (n=12). O grupo Anóxia apresentou decréscimo de 75% no valor da saturação periférica de oxigênio durante a exposição ao nitrogênio, enquanto o Controle não apresentou alterações nos valores (97%±0,5). A análise do número de células IR-Fos mostrou ativação de áreas encefálicas relacionadas ao controle da respiração, estruturas límbicas e núcleos da rafe. Tais dados sugerem que o modelo experimental de anóxia neonatal utilizado é eficiente em produzir privação temporária de oxigênio em ratos neonatos, levando a respostas condizentes com a anóxia. Espera-se, com estes resultados, facilitar a compreensão dos eventos relacionados à neurodegeneração e neurorregeneração após anóxia neonatal e, se possível, abrir caminho para novas abordagens e perspectivas terapêuticas. / The aim of this study is to validate the experimental model of neonatal anoxia and evaluate by Fos imunoreactivity (Fos-IR) the effects of anoxic insult. Twenty-four male wistar neonates (weighting 6-8g) were divided in two groups: Anoxia (n=12) and Control (n=12). The anoxic group presented decrease of 75% in the value of the peripheric saturation of oxygen during exposure to the nitrogen while control group did not present alterations in the values of the peripheric saturation of oxygen during the studied time (97 % ± 0,5). These data suggest that the experimental model of neonatal anoxia presented is efficient in producing temporary deprivation of oxygen in neonates rats, leading to responses that characterize anoxia. Fos-IR neurons analisis showed important activation of respiratory regions, limbic strutures and raphe nuclei in anoxic group when compared to control group. We hope facilitate the understanding of neonatal anoxia neurodegeneration and neuroregeneration and possibly contribute for new approaches and therapeutic perspectives.

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

Objetivo: Determinar el valor predictivo del Índice Cerebro Placentario y del flujo anormal del Ductus Venoso de Aranzio, medido por velocimetría Doppler, en pacientes con preeclampsia, en relación a un resultado perinatal adverso. Materiales y métodos: Estudio prospectivo, no experimental, longitudinal, de tipo correlacional. Se realizaron exámenes ultrasonográficos Doppler para determinar el Índice Cerebro Placentario y el flujo anormal del Ductus Venoso de Aranzio, en los 7 días previos al parto, en 160 pacientes con diagnóstico de preeclampsia severa admitidas en la Unidad de Medicina Fetal y Diagnóstico Prenatal del Servicio de Obstetricia de Alto Riesgo del Hospital Guillermo Almenara Irigoyen – EsSalud. El resultado perinatal adverso fue definido por los siguientes parámetros: Cesárea por SFA, APGAR menor 7 a los 5´, Líquido amniótico meconial, Oligohidramnios, pH de la arteria umbilical menor 7,2, Admisión en UCI neonatal, RCIU. Se utilizó estadística descriptiva para la variable dependiente y estadística inferencial mediante el estadístico chi cuadrado (x²) y prueba exacta de Fisher, con un nivel de significancia de 0,05; confiabilidad del 95%. Además se calculó la sensibilidad, especificidad y valores predictivos positivo y negativo de la variable independiente. Conclusiones: Se ha demostrado que la alteración del Índice Cerebro Placentario y del Flujo del Ductus Venoso de Aranzio medido por flujometría Doppler fetal, detecta a más del 65% de los recién nacidos con resultado perinatal adverso e hipoxia fetal y se asocia a la ocurrencia del mismo. Además esta es una prueba predictiva, estadísticamente significativa, de RCIU y de oligohidramnios, en pacientes con preeclampsia severa. El presente estudio se realizó con un muestreo no aleatorio, por ende, este hecho de no aleatoriedad, pudiera plantear problemas de validez externa. / Objective: To ascertain the value of cerebral-placental ratio and the abnormal fluxo of Aranzio´s Ductus Venous and for identifying newborns with neonatal morbidity in pregnancies complicated by severe preeclampsia. Study Design: A longitudinal and correlational study of 160 patients with severe preeclampsia (PA > 160/110, proteinuria 3+) was performed Doppler study done by one operador within 7 days before delivery. An abnormal cerebral-placental ratio and abnormal resistance and pulsabilility index of ductus venous were used to identificate fetal asphixia (cardiac insuficiency). The results belong 5 percentile were considered abnormal. These results were matched with perinatal results considered as abnormal. Results: Maternal characteristic were: age 33, parity 1, primigravid 45%, prenatal care 85%, gestational age at enrollment 35,1 weeks. The probability of detection IUGR is 65% and oligohydramnios 61,2%. Conclusion: The cerebral-placental ratio and abnormal fluxo of Aranzio´s Ductus venous identifies 65 % or more of the newborns with severe neonatal morbidity in pregnancies with severe preeclampsia. / Tesis