RESUMO
Asphyxia is an insult to the fetus or newborn due to lack 1 of oxygen or lack of perfusion to various organs.National Neonatology Forum of India has de?ned asphyxia as gasping or ineffective breathing or lack of 2breathing at 1 min of life.Birth asphyxia is one of the most important causes of neonatal brain injury whose incidence ranges from 3.7 to 9/1000 deliveries in the 3west.With the advent of therapeutic hypothermia (TH), improved outcomes are being reported in moderate HIE. TH, however, has not demonstrated improvement in outcomes related to severe HIE. . This has led clinicians and researchers to continue evaluating complementary and/or alternative therapies for infants with HIE. In this review, we will discuss current and emerging therapies in the management of HIE, other than hypothermia. With issues of access to health care and the burden of birth asphyxia shifting to developing and least developed nations, there is a need for alternative and supplementary neuroprotective agents. Low cost and easy availability along with ease of use would assist in ensuring that these therapies have global applicability. So global efforts must be taken to increase such studies as birth asphyxia is causing more morbidity & mortality globally
RESUMO
Neonatal asphyxia occurs due to reduction in oxygen supply to vital organs in the newborn. Rapid restoration of oxygen to the lungs after a long period of asphyxia can cause lung injury and decline of respiratory function, which result from the activity of molecules that induce vascular changes in the lung such as nitric oxide (NO) and vascular endothelial growth factors (VEGF). In this study, we evaluated the pulmonary and vascular morphometry of rats submitted to the model of neonatal asphyxia and mechanical ventilation, their expression of pulmonary VEGF, VEGF receptors (VEGFR-1/VEGFR-2), and endothelial NO synthase (eNOS). Neonate Sprague-Dawley rats (CEUA #043/2011) were divided into four groups (n=8 each): control (C), control submitted to ventilation (CV), hypoxia (H), and hypoxia submitted to ventilation (HV). The fetuses were harvested at 21.5 days of gestation. The morphometric variables measured were body weight (BW), total lung weight (TLW), left lung weight (LLW), and TLW/BW ratio. Pulmonary vascular measurements, VEGFR-1, VEGFR-2, VEGF, and eNOS immunohistochemistry were performed. The morphometric analysis showed decreased TLW and TLW/BW ratio in HV compared to C and H (P<0.005). Immunohistochemistry showed increased VEGFR-2/VEGF and decreased VEGFR-1 expression in H (P<0.05) and lower eNOS expression in H and HV. Median wall thickness was increased in H, and the expression of VEGFR-1, VEGFR-2, VEGF, and eNOS was altered, especially in neonates undergoing H and HV. These data suggested the occurrence of arteriolar wall changes mediated by NO and VEGF signaling in neonatal hypoxia.
Assuntos
Animais , Asfixia Neonatal/terapia , Respiração Artificial/efeitos adversos , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/análise , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/análise , Fator A de Crescimento do Endotélio Vascular/análise , Óxido Nítrico Sintase Tipo III/análise , Pulmão/patologia , Arteríolas/patologia , Valores de Referência , Asfixia Neonatal/fisiopatologia , Asfixia Neonatal/patologia , Respiração Artificial/métodos , Imuno-Histoquímica , Ratos Sprague-Dawley , Modelos Animais de Doenças , Pulmão/fisiopatologia , Pulmão/irrigação sanguíneaRESUMO
Os objetivos deste estudo foram descrever a frequência cardíaca (FC) e os índices de variabilidade da frequência cardíaca (VFC) materna e fetal no terço final da gestação, bem como descrever a evolução do desenvolvimento do sistema nervoso autônomo durante o período fetal e neonatal. Foram avaliados 20 animais de cada categoria, cujos exames eletrocardiográficos, maternos e fetais, foram realizados aos 15 e sete dias pré-parto. Quanto ao eletrocardiograma neonatal, os momentos avaliados foram ao nascimento até as primeiras 48 horas de vida, e posteriormente, uma vez por semana até os 35 dias de idade. Ocorreram diferenças significativas na frequência cardíaca fetal (FCF) no período avaliado, porém os índices de VFC fetais não se alteraram. Não foram encontradas diferenças significativas nos índices de VFC materna. A média da FCF diminuiu significativamente dos 15 para sete dias do pré-parto (95,6±11,4 bpm; 83,1±12,6, respectivamente), entretanto os índices de VFC fetal não diminuíram. Os resultados obtidos da VFC fetal e neonatal deste estudo, quando comparados aos maternos, indicaram predomínio parassimpático durante a fase fetal e, simpático durante a neonatal, até a terceira e/ou quarta semanas de idade, momento no qual se inicia o equilíbrio entre os dois sistemas.(AU)
The aim of this study were to describe the heart rate (HR) and indexes of maternal and fetal heart rate variability (HRV) in final period of pregnancy, as well as to describe the evolution of the development of autonomic nervous system during fetal and neonatal period. There were 20 animals in each category, whose maternal and fetal electrocardiographic examinations were performed at 15 and 7 days antepartum. Neonatal ECG it was evaluated at birth until the first 48 hours of life, and then once a week up to 35 days. There were significant differences in fetal heart rate (FHR) during this period, but the fetal HRV indexes have not changed. There were no significant differences in the rates of maternal HRV. The mean of fetal HR decreased significantly from 15 to seven antepartum days (95.6±11.4 bpm; 83.1±12.6, respectively), though the fetal HRV indexes have not decreased. The results of fetal and neonatal HRV in the present study, when compared to maternal indicate the parasympathetic dominance during fetal and neonatal sympathetic phase during to the third and/or fourth weeks of age, at which point begins the modulation of the two systems.(AU)
Assuntos
Animais , Variação Biológica da População , Frequência Cardíaca , Cavalos/fisiologia , Eletrocardiografia/veterinária , HipóxiaRESUMO
Hypoxia ischemic encephalopathy(HIE) is the brain hypoxia ischemic damage resulted from perinatal hypoxia.MRI can reflect not only the anatomical and pathological changes of neonatal HIE,but also the molecular and metabolical changes in early stage,and evaluate the property and degree of HIE without radioactive damage,which is considered as an ideal imaging examination method for neonatal HIE.This review will summarize progresses in application of MRI to neonatal HIE diagnosis and prognosis.
RESUMO
Hypoxia is one of the major causes of damage to the fetal and neonatal brain and cardiac functions. In earlier studies, we have reported the brain damage caused by hypoxia and resuscitation with oxygen and epinephrine and have found that glucose treatment to hypoxic rats and hypoxic rats treated with oxygen shows a reversal of brain damage. The neonatal rats are shown to be deficient in free radical scavenging system, which offers a high risk of oxidative stress. In the present study, we induced hypoxia in neonatal Wistar rats and resuscitated with glucose, oxygen and epinephrine. Heart tissue and cerebral cortex were used to study the kinetics of superoxide dismutase activity in experimental groups of rats to assess the free radical status. Results showed that glucose supplementation in hypoxia (Hx + G) and hypoxic + oxygen (Hx + O) had an efficient free radical scavenging capability, compared to all other experimental groups. The observation was ascertained by studying the activity of catalase, another antioxidant enzyme in the body. Our results suggested that in neonatal rats during hypoxic condition, damage to heart and brain was more prominent in all groups, except when supplemented with glucose. These findings may have clinical significance in the proper management of heart and brain function.