RESUMO
Introducción: la asfixia perinatal es un problema de salud que puede acarrear alteraciones del neurodesarrollo en los recién nacidos. Las determinaciones en suero de enolasa específica de neurona, lactato deshidrogenasa y aspartato amino transferasa han sido utilizadas como marcadores de asfixia perinatal. Objetivos: evaluar el valor de las determinaciones en suero de lactato deshidrogenasa, aspartato amino transferasa y enolasa específica de neurona como marcadores moleculares de la asfixia perinatal. Métodos: se realizó un estudio observacional descriptivo de corte transversal. Se trabajó con una muestra intencional de 41 recién nacidos asfícticos, clasificados con distintos grados de encefalopatía hipóxico-isquémica según los criterios de Sarnat. Se tomaron muestras de suero al momento del nacimiento y a las 72 horas siguientes. Las determinaciones en suero de enolasa específica de neurona se realizaron por ELISA. Se cuantificó lactato deshidrogenasa y aspartato amino transferasa por espectrofotometría. Resultados: todos los pacientes presentaron valores elevados en suero, de los tres analitos, a las 24 y 72 horas de nacidos. Los valores enzimáticos no variaron significativamente entre las 24 y 72 horas de nacidos sin tomar en cuenta el grado de encefalopatía hipóxico-isquémica. Existe correlación positiva entre los valores enzimáticos a las 24 y a las 72 horas de enolasa específica de neurona y lactato deshidrogenasa. No fue posible diferenciar el grado de encefalopatía hipóxico-isquémica a través de los niveles en suero de estas enzimas. Conclusiones: los valores de estas determinaciones enzimáticas contribuyen a describir desde el punto de vista bioquímico el cuadro del neonato con asfixia perinatal(AU)
Introduction: perinatal asphyxia is a health problem which may cause neurodevelopmental alterations in newborns. Serum determinations of neuron-specific enolase, lactate dehydrogenase, and aspartate aminotransferase have been used as markers of perinatal asphyxia. Objectives: evaluate the value of serum determinations of lactate dehydrogenase, aspartate aminotransferase and neuron-specific enolase as molecular markers of perinatal asphyxia. Methods: a cross-sectional observational descriptive study was conducted of 41 asphyxiated newborns classified as different grades of hypoxic-ischemic encephalopathy according to Sarnat's scale. Serum samples were taken at birth and 72 hours later. Serum determinations of neuron-specific enolase were obtained by ELISA. Lactate dehydrogenase and aspartate aminotransferase were quantified by espectrophotometry. Results: all the patients had high serum values of the three analytes 24 and 72 hours after birth. Enzyme values did not vary significantly from 24 to 72 hours after birth, not considering the grade of hypoxic-ischemic encephalopathy. A positive correlation was found between enzyme values for neuron-specific enolase and lactate dehydrogenase at 24 and 72 hours. It was not possible to differentiate the grade of hypoxic-ischemic encephalopathy via the serum levels of these enzymes. Conclusions: the values of these enzyme determinations contribute to describe the status of neonates with perinatal asphyxia from a biochemical point of view(AU)
Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Asfixia Neonatal/enzimologia , Fosfopiruvato Hidratase/imunologiaRESUMO
BACKGROUND: Thioredoxin (Trx) family proteins are crucial mediators of cell functions via regulation of the thiol redox state of various key proteins and the levels of the intracellular second messenger hydrogen peroxide. Their expression, localization and functions are altered in various pathologies. Here, we have analyzed the impact of Trx family proteins in neuronal development and recovery, following hypoxia/ischemia and reperfusion. METHODS: We have analyzed the regulation and potential functions of Trx family proteins during hypoxia/ischemia and reoxygenation of the developing brain in both an animal and a cellular model of perinatal asphyxia. We have analyzed the distribution of 14 Trx family and related proteins in the cerebellum, striatum, and hippocampus, three areas of the rat brain that are especially susceptible to hypoxia. Using SH-SY5Y cells subjected to hypoxia and reoxygenation, we have analyzed the functions of some redoxins suggested by the animal experiment. RESULTS AND CONCLUSIONS: We have described/discovered a complex, cell-type and tissue-specific expression pattern following the hypoxia/ischemia and reoxygenation. Particularly, Grx2 and Trx1 showed distinct changes during tissue recovery following hypoxia/ischemia and reoxygenation. Silencing of these proteins in SH-SY5Y cells subjected to hypoxia-reoxygenation confirmed that these proteins are required to maintain the normal neuronal phenotype. GENERAL SIGNIFICANCE: These findings demonstrate the significance of redox signaling in cellular pathways. Grx2 and Trx1 contribute significantly to neuronal integrity and could be clinically relevant in neuronal damage following perinatal asphyxia and other neuronal disorders.
Assuntos
Asfixia Neonatal/enzimologia , Encéfalo/enzimologia , Glutarredoxinas/metabolismo , Hipóxia-Isquemia Encefálica/enzimologia , Neurônios/enzimologia , Tiorredoxinas/metabolismo , Animais , Asfixia Neonatal/patologia , Encéfalo/patologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Glutarredoxinas/genética , Humanos , Hipóxia-Isquemia Encefálica/patologia , Masculino , Neurônios/patologia , Oxirredução , Oxigênio/metabolismo , Fenótipo , Interferência de RNA , Ratos Sprague-Dawley , Transdução de Sinais , Tiorredoxinas/genética , Fatores de Tempo , TransfecçãoRESUMO
Perinatal asphyxia (PA) produces changes in nitric oxide synthase (NOS) activity in neuronal and endothelial cells of the striatum and neocortex. The changes were examined using a histochemical NADPH-diaphorase (NADPH-d) staining method. Newborn rats were exposed to severe PA at 37 degrees C and other groups were subjected to severe PA under hypothermic condition (15 degrees C) for 20 or 100 min, respectively. Quantitative image analysis was performed on the striatum and neocortex in order to count cell number of reactive neurons and to compare the pattern of staining between the different groups of animals. Severe asphyctic pups showed an important neuronal loss in striatum and neocortex that was reduced by hypothermia. NADPH-d(+) neurons with reactive processes were found in the lateral zone of the striatum and neocortex in asphyctic pups. Controls and hypothermic striatum showed rounded cells without reactive process, while no cells were stained in cortex. There was also an increase in NADPH-d activity in endothelial cells in severe asphyctic pups in striatum and neocortex vs control and hypothermically treated animals. Our data evidenced that an inappropriate activation of NOS in neuronal and endothelial cells induced by PA is related to neuronal injury. Hypothermia inhibits neuronal injury and may be a valuable neuroprotective agent.
Assuntos
Animais Recém-Nascidos/fisiologia , Asfixia Neonatal/enzimologia , Encéfalo/enzimologia , Hipotermia Induzida , NADPH Desidrogenase/metabolismo , Animais , Asfixia Neonatal/patologia , Asfixia Neonatal/prevenção & controle , Comportamento Animal , Encéfalo/patologia , Feminino , Histocitoquímica , Humanos , Processamento de Imagem Assistida por Computador , Recém-Nascido , Neocórtex/enzimologia , Neocórtex/patologia , Neostriado/enzimologia , Neostriado/patologia , Neurônios/enzimologia , Óxido Nítrico Sintase/metabolismo , Gravidez , RatosRESUMO
Nitric oxide (NO) is known to be involved in the neuropathological mechanisms triggered by excitatory aminoacids. NO(+) neurons in the brain may be detected histochemically by nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemical technique, as the latter readily labels NO synthase in the central nervous system (CNS). NADPH-d stained striatal and cortical sections were studied in 6-month-old male Sprague-Dawley rats exposed to perinatal asphyxia (PA) at 37 degrees C, as well as in animals subjected to PA plus hypothermia treatment at 15 degrees C. Quantitative image analysis was performed to compare the staining pattern in the various groups. NADPH-d(+) neurons in striatum and cortex from subsevere and severe asphyctic animals showed a significant increase in soma size and in dendritic processes versus controls and hypothermia-treated rats. These findings indicate that chronic NO changes are involved in postischemic striatal and cortical alterations induced by PA that may be prevented by hypothermia.
Assuntos
Asfixia Neonatal/enzimologia , Córtex Cerebral/metabolismo , Hipotermia Induzida , NADPH Desidrogenase/metabolismo , Neostriado/metabolismo , Neurônios/enzimologia , Animais , Asfixia Neonatal/terapia , Benzoxazinas , Córtex Cerebral/citologia , Corantes , Feminino , Histocitoquímica , Humanos , Processamento de Imagem Assistida por Computador , Recém-Nascido , Masculino , Neostriado/citologia , Oxazinas , Gravidez , Ratos , Ratos Sprague-DawleyRESUMO
Striatal and cortical neurons containing nitric oxide synthase (NOS) were studied in adult rats subjected to different periods of perinatal asphyxia (PA) using immunohistochemistry at both light microscopy (LM) and electron microscopy (EM). Another group was subjected to PA + hypothermia to study its neuroprotective effect. Quantitative image analysis was performed on the striatum and neocortex in order to count the number of immunoreactive neurons and to compare the pattern of staining between the different groups. Six-month-old rats that suffered subsevere and severe PA demonstrated, at LM, cytomegaly of the striatal and neocortical neurons containing NOS. Control and hypothermic neurons were more weakly immunostained than PA neurons. Subsevere and severe asphyctic rats showed an important neuronal loss that was reduced by hypothermic treatment. The PA group disclosed, at EM, dense electronic bodies distributed in terminals surrounding synaptic vesicles and in dendrites. Non-NOS-containing neurons showed signs of degeneration, such as dark cytoplasm and shrunken nuclei. Surrounding the blood vessels, we observed a clear edema. The immunolabeling in hypothermic rats resembled that observed in controls. These data suggest that subsevere and severe PA induces chronic changes in the neuronal content of NOS in the striatum and neocortex. Degeneration observed in neurons surrounding cytomegalic NOS-containing cells may be due to the excess of NO in their environment. Moreover, the chronic alterations produced by PA seem to be prevented by hypothermia.
Assuntos
Asfixia Neonatal/enzimologia , Asfixia Neonatal/terapia , Encéfalo/enzimologia , Encéfalo/patologia , Hipotermia Induzida , Óxido Nítrico Sintase/metabolismo , Animais , Asfixia Neonatal/patologia , Benzoxazinas , Encéfalo/ultraestrutura , Corantes , Feminino , Humanos , Imuno-Histoquímica , Recém-Nascido , Microscopia Eletrônica , Neurônios/enzimologia , Neurônios/ultraestrutura , Oxazinas , Gravidez , Ratos , Ratos Sprague-DawleyRESUMO
A prospective study in 76 newborn with perinatal asphyxia searching for myocardial ischemia was carried out. The disease was found in 51% of the patients. With electrocardiogram, myocardial enzymes, X ray and clinical manifestations the diagnosis was elaborated. No difference in the sex was present, the mean of gestational age was 35 weeks, and with mean birth weight 2,216 g, respiratory distress was present in all the people; only 20.5% developed heart failure and two had heart murmurs; 61.5% showed cardiomegaly. The creatine kinase MB isoenzyme at twelve hours after birth was raised in most of the patients. Respiratory distress syndrome was the principal diagnosis in 38%; hypoxic ischemic encephalopathy and peri-intraventricular hemorrhage was present in 50 and 33% of the patients, respectively. Mortality rate was 33%. Also a comparative study in the infants with and without myocardial ischemia was carried out appearing significative difference in: 1. Cardiomegaly, 2. Hypoxic-ischemic encephalopathy and 3. Creatine kinase MB isoenzyme.
Assuntos
Asfixia Neonatal/complicações , Cardiomiopatias/etiologia , Doença das Coronárias/etiologia , Asfixia Neonatal/enzimologia , Cardiomiopatias/enzimologia , Cardiomiopatias/fisiopatologia , Doença das Coronárias/enzimologia , Doença das Coronárias/fisiopatologia , Creatina Quinase/sangue , Feminino , Humanos , Recém-Nascido , Isoenzimas , Masculino , Estudos Prospectivos , Fatores de RiscoRESUMO
Brain-type isoenzyme of creatine kinase was measured serially in 45 healthy and 22 severely asphyxiated term infants. The enzyme was measured in cord blood and in venous, capillary, or arterial blood at six to eight hours, 24 to 30 hours, and 72 to 80 hours after birth. In the healthy infants a brief rise of CK-BB occurred at six to eight hours; CK-BB activities were greater than 2.5 log-transformed standard deviations above the mean of the control values in ten of the asphyxiated infants and in none of the control infants. When normal CK-BB activity was used as a predictor of good neurologic outcome and elevated CK-BB as a predictor of subsequent neurologic abnormality, the outcome was predictable from the CK-BB activity in 17 of 22 cases (77%) and in 11 of the 12 survivors (92%). Eight of the 12 surviving infants had neonatal seizures and outcome was predictable from CK-BB activity in all cases. We conclude that serum CK-BB activity, especially when measured in cord blood and at six to 12 hours of life, correlates with neurologic outcome after severe asphyxia, and that measurement of CK-BB compares favorably with radionuclide and computerized tomographic scanning as a method of predicting neurologic outcome after asphyxia.