Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 568
Filtrar
1.
Oxid Med Cell Longev ; 2022: 3255296, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35132347

RESUMO

Near-term acute hypoxia in utero can result in significant fetal brain injury, with some brain regions more vulnerable than others. As mitochondrial dysfunction is an underlying feature of the injury cascade following hypoxia, this study is aimed at characterizing mitochondrial function at a region-specific level in the near-term fetal brain after a period of acute hypoxia. We hypothesized that regional differences in mitochondrial function would be evident, and that prophylactic creatine treatment would mitigate mitochondrial dysfunction following hypoxia; thereby reducing fetal brain injury. Pregnant Border-Leicester/Merino ewes with singleton fetuses were surgically instrumented at 118 days of gestation (dGa; term is ~145 dGA). A continuous infusion of either creatine (n = 15; 6 mg/kg/h) or isovolumetric saline (n = 16; 1.5 ml/kg/h) was administered to the fetuses from 121 dGa. After 10 days of infusion, a subset of fetuses (8 saline-, 7 creatine-treated) were subjected to 10 minutes of umbilical cord occlusion (UCO) to induce a mild global fetal hypoxia. At 72 hours after UCO, the fetal brain was collected for high-resolution mitochondrial respirometry and molecular and histological analyses. The results show that the transient UCO-induced acute hypoxia impaired mitochondrial function in the hippocampus and the periventricular white matter and increased the incidence of cell death in the hippocampus. Creatine treatment did not rectify the changes in mitochondrial respiration associated with hypoxia, but there was a negative relationship between cell death and creatine content following treatment. Irrespective of UCO, creatine increased the proportion of cytochrome c bound to the inner mitochondrial membrane, upregulated the mRNA expression of the antiapoptotic gene Bcl2, and of PCG1-α, a driver of mitogenesis, in the hippocampus. We conclude that creatine treatment prior to brief, acute hypoxia does not fundamentally modify mitochondrial respiratory function, but may improve mitochondrial structural integrity and potentially increase mitogenesis and activity of antiapoptotic pathways.


Assuntos
Lesões Encefálicas/etiologia , Lesões Encefálicas/metabolismo , Creatina/administração & dosagem , Hipóxia Fetal/complicações , Feto/metabolismo , Idade Gestacional , Hipocampo/metabolismo , Mitocôndrias/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Citocromos c/metabolismo , Modelos Animais de Doenças , Feminino , Mitocôndrias/efeitos dos fármacos , Membranas Mitocondriais/metabolismo , Gravidez , Proteínas Proto-Oncogênicas c-bcl-2/genética , Ovinos , Resultado do Tratamento , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
2.
Minerva Obstet Gynecol ; 74(3): 288-293, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34096693

RESUMO

BACKGROUND: Perinatal asphyxia can cause cerebral palsy and hypoxic-ischemic encephalopathy. They are public health problems because they cause permanent disability. METHODS: This is a retrospective, analytical, observational study. Overall, 162 cases of mothers whose children experienced fetal asphyxia were compared to 361 controls where this condition did not occur. The variables analyzed were classified as: prepartum, intrapartum and organizational. RESULTS: Assisted reproductive technology obtained pregnancies, smoking, maternal body mass index, lack of one-to-one assistance during labor, birth on a day of high-volume activity increased the risk of fetal asphyxia, as well as other traditionally linked factors like shoulder dystocia or age over 35 years. CONCLUSIONS: Cerebral palsy cannot always be prevented because it is a syndrome with a multitude of potential causes. But a small number of cases is likely to be linked to acute intrapartum events that could be limited by changing organizational policies such as staff training and implementing teamwork and discussion. Our paper proposes strategies to try and modify organizational risk factors and therefore limit the incidence of fetal asphyxia.


Assuntos
Asfixia Neonatal , Paralisia Cerebral , Adulto , Asfixia/prevenção & controle , Asfixia Neonatal/epidemiologia , Paralisia Cerebral/epidemiologia , Criança , Feminino , Hipóxia Fetal/complicações , Humanos , Recém-Nascido , Gravidez , Estudos Retrospectivos
3.
Sci Rep ; 11(1): 16799, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34408219

RESUMO

Foetal hypoxia-ischaemia is a key trigger of meconium aspiration syndrome (MAS). However, many neonates develop MAS without evidence of hypoxia-ischaemia, suggesting the presence of covert but important risk variables. We evaluated the association of MAS with clinical variables, placental histopathologic findings, and inflammatory biomarkers at birth. Of 1336 symptomatic and asymptomatic term singleton neonates with meconium-stained amniotic fluid, 88 neonates (6.6%) developed MAS. Univariate analysis showed that MAS development was associated with low 1- and 5-min Apgar scores, low cord blood pH, funisitis, higher α1-acid glycoprotein levels, and higher haptoglobin levels (all p < 0.001 except for p = 0.001 for haptoglobin). Associations of MAS with caesarean delivery (p = 0.004), premature rupture of the membranes (p = 0.006), chorioamnionitis (p = 0.007), and higher C-reactive protein levels (p = 0.008) were lost when adjusted for multiple comparisons. The final multivariate model to explain MAS development comprised lower cord blood pH (odds ratio [OR] 0.58; 95% confidence interval [CI] 0.47-0.73; p < 0.001), funisitis (OR 2.45; 95% Cl 1.41-4.26; p = 0.002), and higher α1-acid glycoprotein levels (OR 1.02; 95% Cl 1.01-1.03; p = 0.001). Our data from a large cohort of neonates suggested that intrauterine inflammation is one of the key independent variables of MAS development, together with foetal hypoxia-ischaemia.


Assuntos
Hipóxia Fetal/fisiopatologia , Hipóxia-Isquemia Encefálica/fisiopatologia , Inflamação/fisiopatologia , Síndrome de Aspiração de Mecônio/fisiopatologia , Proteína C-Reativa/genética , Corioamnionite/genética , Corioamnionite/fisiopatologia , Feminino , Hipóxia Fetal/complicações , Hipóxia Fetal/genética , Humanos , Hipóxia-Isquemia Encefálica/complicações , Hipóxia-Isquemia Encefálica/genética , Recém-Nascido , Inflamação/complicações , Masculino , Síndrome de Aspiração de Mecônio/complicações , Síndrome de Aspiração de Mecônio/genética , Placenta/metabolismo , Placenta/fisiopatologia , Gravidez , Respiração Artificial , Fatores de Risco
5.
S Afr Med J ; 111(3b): 280-288, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33944711

RESUMO

The science surrounding cerebral palsy indicates  that it is a complex medical condition with multiple contributing variables and factors, and causal pathways are often extremely difficult to delineate. The pathophysiological processes are often juxtaposed on antenatal factors, genetics, toxins, fetal priming, failure of neuroscientific autoregulatory mechanisms, abnormal biochemistry and abnormal metabolic pathways. Placing this primed compromised compensated brain through the stresses of an intrapartum process could be the final straw in the pathway  to brain injury and later CP.  It is thus simplistic to base causation of cerebral palsy on only an intrapartum perspective with radiological 'confirmation', as is often the practice in medicolegal cases in South African courts. The present modalities (MRI and CTG when available) that retrospectively attempt to determine causation in courts are inadequate when used in isolation. Unless a holistic scientific review of the case including all contributing clinical factors (antepartum, intrapartum and neonatal), fetal heart rate monitoring, neonatal MRI if possible (and preferred) or late MRI, and histology (placental histology if performed) are taken into account, success for plaintiff or defendant currently in a court of law will depend on eloquent legal argument rather than true scientific causality. The 10 criteria set out in this document to implicate acute intrapartum hypoxia in hypoxic ischaemic encephalopathy/neonatal encephalopathy serve as a guideline in the medicolegal setting.


Assuntos
Paralisia Cerebral/etiologia , Hipóxia Fetal/complicações , Hipóxia Fetal/diagnóstico , Hipóxia-Isquemia Encefálica/complicações , Hipóxia-Isquemia Encefálica/diagnóstico , Cardiotocografia , Feminino , Humanos , Recém-Nascido , Responsabilidade Legal , Imageamento por Ressonância Magnética , Gravidez , Diagnóstico Pré-Natal , África do Sul
6.
FASEB J ; 35(5): e21477, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33891326

RESUMO

Chronic fetal hypoxia is one of the most common outcomes in complicated pregnancy in humans. Despite this, its effects on the long-term health of the brain in offspring are largely unknown. Here, we investigated in rats whether hypoxic pregnancy affects brain structure and function in the adult offspring and explored underlying mechanisms with maternal antioxidant intervention. Pregnant rats were randomly chosen for normoxic or hypoxic (13% oxygen) pregnancy with or without maternal supplementation with vitamin C in their drinking water. In one cohort, the placenta and fetal tissues were collected at the end of gestation. In another, dams were allowed to deliver naturally, and offspring were reared under normoxic conditions until 4 months of age (young adult). Between 3.5 and 4 months, the behavior, cognition and brains of the adult offspring were studied. We demonstrated that prenatal hypoxia reduced neuronal number, as well as vascular and synaptic density, in the hippocampus, significantly impairing memory function in the adult offspring. These adverse effects of prenatal hypoxia were independent of the hypoxic pregnancy inducing fetal growth restriction or elevations in maternal or fetal plasma glucocorticoid levels. Maternal vitamin C supplementation during hypoxic pregnancy protected against oxidative stress in the placenta and prevented the adverse effects of prenatal hypoxia on hippocampal atrophy and memory loss in the adult offspring. Therefore, these data provide a link between prenatal hypoxia, placental oxidative stress, and offspring brain health in later life, providing insight into mechanism and identifying a therapeutic strategy.


Assuntos
Ácido Ascórbico/uso terapêutico , Atrofia/tratamento farmacológico , Hipóxia Fetal/complicações , Hipocampo/efeitos dos fármacos , Transtornos da Memória/tratamento farmacológico , Efeitos Tardios da Exposição Pré-Natal/tratamento farmacológico , Animais , Animais Recém-Nascidos , Antioxidantes/uso terapêutico , Atrofia/etiologia , Atrofia/metabolismo , Atrofia/patologia , Suplementos Nutricionais , Modelos Animais de Doenças , Feminino , Retardo do Crescimento Fetal/tratamento farmacológico , Retardo do Crescimento Fetal/etiologia , Retardo do Crescimento Fetal/metabolismo , Retardo do Crescimento Fetal/patologia , Masculino , Transtornos da Memória/etiologia , Transtornos da Memória/metabolismo , Transtornos da Memória/patologia , Gravidez , Complicações na Gravidez/tratamento farmacológico , Complicações na Gravidez/etiologia , Complicações na Gravidez/metabolismo , Complicações na Gravidez/patologia , Efeitos Tardios da Exposição Pré-Natal/etiologia , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Efeitos Tardios da Exposição Pré-Natal/patologia , Ratos , Ratos Wistar
7.
Am J Obstet Gynecol ; 225(5): 544.e1-544.e9, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33887239

RESUMO

BACKGROUND: Nifedipine is a widely used drug in pregnancies complicated by maternal hypertensive disorders that can be associated with placental insufficiency and fetal hypoxemia. The evidence regarding fetal myocardial responses to nifedipine in hypoxemia is limited. OBJECTIVE: We hypothesized that nifedipine would not impair fetal sheep cardiac function under hypoxemic environment. In particular, we investigated the effects of nifedipine on fetal ventricular functional parameters and cardiac output. STUDY DESIGN: A total of 21 chronically instrumented fetal sheep at 122 to 134 gestational days (term, 145 days) were included in this study. Fetal cardiac function was evaluated by measuring global longitudinal strain, indices describing ventricular systolic and diastolic function, and cardiac outputs using two-dimensional speckle tracking and tissue and spectral pulsed-wave Doppler echocardiography. Fetal carotid artery blood pressure and blood gas values were invasively monitored. After baseline data collection, fetal hypoxemia was induced by maternal hyperoxygenation. After hypoxemia phase data collection, 9 fetuses received nifedipine infusion, and 12 fetuses received saline infusion. Data were collected 30 and 120 minutes after the infusion was started. After 120 minutes of data collection, maternal and fetal oxygenation were normalized, and normoxemia phase data were collected, while infusion was continued. RESULTS: Hypoxemia decreased fetal carotid artery mean arterial pressure from 40 (8) mm Hg to 35 (8) mm Hg (P<.007), and left ventricular global longitudinal strain showed less deformation than at baseline (P=.001). Under hypoxemia, nifedipine caused a reduction in right ventricular global longitudinal strain (P<.05), a decrease in right ventricular isovolumic relaxation velocity and its deceleration (P<.01) indicating diastolic dysfunction, and a drop in right ventricular cardiac output (P<.05). Nifedipine did not alter fetal left ventricular functional parameters or cardiac output. When normoxemia was restored, fetal right ventricular functional parameters and cardiac output returned to baseline level. CONCLUSION: In hypoxemic fetus, nifedipine impaired right ventricular function and reduced its cardiac output. The detrimental effects of nifedipine on fetal right ventricular function were abolished, when normoxemia was restored. Our findings suggest that in a hypoxemic environment nifedipine triggers detrimental effects on fetal right ventricular function.


Assuntos
Bloqueadores dos Canais de Cálcio/efeitos adversos , Débito Cardíaco/efeitos dos fármacos , Hipóxia Fetal/complicações , Nifedipino/efeitos adversos , Disfunção Ventricular Direita/induzido quimicamente , Animais , Pressão Arterial/efeitos dos fármacos , Artérias Carótidas/efeitos dos fármacos , Diástole/efeitos dos fármacos , Ecocardiografia Doppler de Pulso , Monitorização Fetal , Modelos Animais , Ovinos
8.
Am J Physiol Heart Circ Physiol ; 320(5): H1873-H1886, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33739154

RESUMO

Compared with acyanotic congenital heart disease (CHD), cyanotic CHD has an increased risk of lifelong mortality and morbidity. These adverse outcomes may be attributed to delayed cardiomyocyte maturation, since the transition from a hypoxic fetal milieu to oxygen-rich postnatal environment is disrupted. We established a rodent model to replicate hypoxic myocardial conditions spanning perinatal development, and tested the hypothesis that chronic hypoxia impairs cardiac development. Pregnant mice were housed in hypoxia beginning at embryonic day 16. Pups stayed in hypoxia until postnatal day (P)8 when cardiac development is nearly complete. Global gene expression was quantified at P8 and at P30, after recovering in normoxia. Phenotypic testing included electrocardiogram, echocardiogram, and ex vivo electrophysiology study. Hypoxic P8 animals were 47% smaller than controls with preserved heart size. Gene expression was grossly altered by hypoxia at P8 (1,427 genes affected), but normalized after recovery (P30). Electrocardiograms revealed bradycardia and slowed conduction velocity in hypoxic animals at P8, with noticeable resolution after recovery (P30). Notable differences that persisted after recovery (P30) included a 65% prolongation in ventricular effective refractory period, sinus node dysfunction, 23% reduction in ejection fraction, and 16% reduction in fractional shortening in animals exposed to hypoxia. We investigated the impact of chronic hypoxia on the developing heart. Perinatal hypoxia was associated with changes in gene expression and cardiac function. Persistent changes to the electrophysiological substrate and contractile function warrant further investigation and may contribute to adverse outcomes observed in the cyanotic CHD population.NEW & NOTEWORTHY We utilized a new mouse model of chronic perinatal hypoxia to simulate the hypoxic myocardial conditions present in cyanotic congenital heart disease. Hypoxia caused numerous abnormalities in cardiomyocyte gene expression, the electrophysiologic substrate of the heart, and contractile function. Taken together, alterations observed in the neonatal period suggest delayed cardiac development immediately following hypoxia.


Assuntos
Cianose/etiologia , Coração Fetal/crescimento & desenvolvimento , Cardiopatias Congênitas/etiologia , Hipóxia/complicações , Fatores Etários , Animais , Animais Recém-Nascidos , Doença Crônica , Cianose/genética , Cianose/metabolismo , Cianose/fisiopatologia , Modelos Animais de Doenças , Feminino , Coração Fetal/metabolismo , Hipóxia Fetal/complicações , Hipóxia Fetal/genética , Hipóxia Fetal/metabolismo , Hipóxia Fetal/fisiopatologia , Regulação da Expressão Gênica no Desenvolvimento , Idade Gestacional , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/metabolismo , Cardiopatias Congênitas/fisiopatologia , Frequência Cardíaca , Hipóxia/genética , Hipóxia/metabolismo , Hipóxia/fisiopatologia , Camundongos , Contração Miocárdica , Miócitos Cardíacos/metabolismo , Organogênese , Gravidez , Efeitos Tardios da Exposição Pré-Natal
9.
FASEB J ; 35(5): e21446, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33788974

RESUMO

Mitochondria-derived oxidative stress during fetal development increases cardiovascular risk in adult offspring of pregnancies complicated by chronic fetal hypoxia. We investigated the efficacy of the mitochondria-targeted antioxidant MitoQ in preventing cardiovascular dysfunction in adult rat offspring exposed to gestational hypoxia, integrating functional experiments in vivo, with those at the isolated organ and molecular levels. Rats were randomized to normoxic or hypoxic (13%-14% O2 ) pregnancy ± MitoQ (500 µM day-1 ) in the maternal drinking water. At 4 months of age, one cohort of male offspring was chronically instrumented with vascular catheters and flow probes to test in vivo cardiovascular function. In a second cohort, the heart was isolated and mounted onto a Langendorff preparation. To establish mechanisms linking gestational hypoxia with cardiovascular dysfunction and protection by MitoQ, we quantified the expression of antioxidant system, ß-adrenergic signaling, and calcium handling genes in the fetus and adult, in frozen tissues from a third cohort. Maternal MitoQ in hypoxic pregnancy protected offspring against increased α1 -adrenergic reactivity of the cardiovascular system, enhanced reactive hyperemia in peripheral vascular beds, and sympathetic dominance, hypercontractility and diastolic dysfunction in the heart. Inhibition of Nfe2l2-mediated oxidative stress in the fetal heart and preservation of calcium regulatory responses in the hearts of fetal and adult offspring link molecular mechanisms to the protective actions of MitoQ treatment of hypoxic pregnancy. Therefore, these data show the efficacy of MitoQ in buffering mitochondrial stress through NADPH-induced oxidative damage and the prevention of programmed cardiovascular disease in adult offspring of hypoxic pregnancy.


Assuntos
Antioxidantes/farmacologia , Doenças Cardiovasculares/prevenção & controle , Hipóxia Fetal/complicações , Mitocôndrias/metabolismo , Estresse Oxidativo , Efeitos Tardios da Exposição Pré-Natal/prevenção & controle , Animais , Animais Recém-Nascidos , Cálcio/metabolismo , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/patologia , Feminino , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal/etiologia , Efeitos Tardios da Exposição Pré-Natal/patologia , Ratos , Ratos Wistar
10.
Am J Physiol Heart Circ Physiol ; 320(3): H980-H990, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33416457

RESUMO

Perinatal hypoxia induces permanent structural and functional changes in the lung and its pulmonary circulation that are associated with the development of pulmonary hypertension (PH) in later life. The mechanistic target of the rapamycin (mTOR) pathway is vital for fetal lung development and is implicated in hypoxia-associated PH, yet its involvement in the developmental programming of PH remains unclear. Pregnant C57/BL6 dams were placed in hyperbaric (760 mmHg) or hypobaric chambers during gestation (505 mmHg, day 15 through postnatal day 4) or from weaning through adulthood (420 mmHg, postnatal day 21 through 8 wk). Pulmonary hemodynamics and right ventricular systolic pressure (RVSP) were measured at 8 wk. mTOR pathway proteins were assessed in fetal (day 18.5) and adult lung (8 wk). Perinatal hypoxia induced PH during adulthood, even in the absence of a sustained secondary hypoxic exposure, as indicated by reduced pulmonary artery acceleration time (PAAT) and peak flow velocity through the pulmonary valve, as well as greater RVSP, right ventricular (RV) wall thickness, and RV/left ventricular (LV) weight. Such effects were independent of increased blood viscosity. In fetal lung homogenates, hypoxia reduced the expression of critical downstream mTOR targets, most prominently total and phosphorylated translation repressor protein (4EBP1), as well as vascular endothelial growth factor, a central regulator of angiogenesis in the fetal lung. In contrast, adult offspring of hypoxic dams tended to have elevated p4EBP1 compared with controls. Our data suggest that inhibition of mTORC1 activity in the fetal lung as a result of gestational hypoxia may interrupt pulmonary vascular development and thereby contribute to the developmental programming of PH.NEW & NOTEWORTHY We describe the first study to evaluate a role for the mTOR pathway in the developmental programming of pulmonary hypertension. Our findings suggest that gestational hypoxia impairs mTORC1 activation in the fetal lung and may impede pulmonary vascular development, setting the stage for pulmonary vascular disease in later life.


Assuntos
Hipóxia Fetal/complicações , Hipertensão Pulmonar/etiologia , Pulmão/irrigação sanguínea , Pulmão/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Neovascularização Fisiológica , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Ciclo Celular/metabolismo , Modelos Animais de Doenças , Feminino , Hipóxia Fetal/metabolismo , Hipóxia Fetal/fisiopatologia , Idade Gestacional , Hemodinâmica , Oxigenoterapia Hiperbárica , Hipertensão Pulmonar/metabolismo , Hipertensão Pulmonar/fisiopatologia , Camundongos Endogâmicos C57BL , Fosforilação , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Circulação Pulmonar , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/metabolismo , Função Ventricular Direita , Pressão Ventricular
11.
Can J Physiol Pharmacol ; 99(1): 1-8, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32687731

RESUMO

Epidemiological studies have demonstrated a relationship between the adverse influence of perinatal development and increased risk of ischemic heart disease in adults. From negative factors to which the fetus is subjected, the most important is hypoxia. The fetus may experience hypoxic stress under different conditions, including pregnancy at high altitude, pregnancy with anemia, placental insufficiency, and heart, lung, and kidney disease. One of the most common insults during the early stages of postnatal development is hypoxemia due to congenital cyanotic heart defects. Experimental studies have demonstrated a link between early hypoxia and increased risk of ischemia/reperfusion injury (I/R) in adults. Furthermore, it has been observed that late myocardial effects of chronic hypoxia, experienced in early life, may be sex-dependent. Unlike in males, perinatal hypoxia significantly increased cardiac tolerance to acute I/R injury in adult females, expressed as decreased infarct size and lower incidence of ischemic arrhythmias. It was suggested that early hypoxia may result in sex-dependent programming of specific genes in the offspring with the consequence of increased cardiac susceptibility to I/R injury in adult males. These results would have important clinical implications, since cardiac sensitivity to oxygen deprivation in adult patients may be significantly influenced by perinatal hypoxia in a sex-dependent manner.


Assuntos
Hipóxia Fetal/complicações , Isquemia Miocárdica/epidemiologia , Traumatismo por Reperfusão Miocárdica/epidemiologia , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Adulto , Feminino , Hipóxia Fetal/fisiopatologia , Coração/embriologia , Coração/fisiopatologia , Humanos , Masculino , Isquemia Miocárdica/etiologia , Isquemia Miocárdica/fisiopatologia , Traumatismo por Reperfusão Miocárdica/etiologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Oxigênio/metabolismo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/etiologia , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Fatores de Risco , Fatores Sexuais
12.
Physiol Res ; 70(S3): S431-S440, 2021 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-35099261

RESUMO

Attention-deficit/hyperactivity disorder (ADHD) is a mental disorder with a heterogeneous origin with a global incidence that continues to grow. Its causes and pathophysiological mechanisms are not fully understood. It includes a combination of persistent symptoms such as difficulty in concentration, hyperactivity and impulsive behavior. Maternal methamphetamine (MA) abuse is a serious problem worldwide, it can lead to behavioral changes in their offspring that have similarities with behavioral changes seen in children with ADHD. There are several types of ADHD animal models, e.g. genetic models, pharmacologically, chemically and exogenously induced models. One of the exogenously induced ADHD models is the hypoxia-induced model. Our studies, as well as those of others, have demonstrated that maternal MA exposure can lead to abnormalities in the placenta and umbilical cord that result in prenatal hypoxia as well as fetal malnutrition that can result in irreversible changes to experimental animals. Therefore, the aim the present study was to compare the cognitive impairments in MA exposure model with those in established model of ADHD - prenatal hypoxia model, to test whether MA exposure is a valid model of ADHD. Pregnant Wistar rats were divided into four groups based on their gestational exposure to MA: (1) daily subcutaneous injections of MA (5 mg/kg), (2) saline injections at the same time and volume, (3) daily 1-hr hypoxia (10 % O2), and (4) no gestational exposure (controls). Male rat offspring were tested for short-term memory in the Novel Object Recognition Test and the Object Location Test between postnatal days 35 and 40. Also their locomotor activity in both tests was measured. Based on the present results, it seems that prenatal MA exposure is not the best animal model for ADHD since it shows corresponding symptoms only in certain measures. Given our previous results supporting our hypothesis, more experiments are needed to further test possible use of prenatal MA exposure as an animal model of the ADHD.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/induzido quimicamente , Comportamento Animal , Metanfetamina , Efeitos Tardios da Exposição Pré-Natal , Animais , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Cognição , Modelos Animais de Doenças , Feminino , Hipóxia Fetal/complicações , Idade Gestacional , Locomoção , Exposição Materna , Gravidez , Ratos Wistar
13.
Mol Med Rep ; 22(5): 4173-4182, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33000260

RESUMO

Pulmonary hypertension (PH) in newborns and adults is a disease that can lead to right heart failure and result in a shorter lifespan. PH was induced by maintaining pregnant rats in a hypoxic chamber for 4 h twice a day, from days 7­21 of pregnancy. Hypoxia was confirmed by a decrease in the partial pressure of oxygen (PaO2) and the oxygen saturation (SaO2) of arterial blood in the aorta. The body weight of newborns from hypoxic rats was ~20% decreased compared with the control newborns of normoxic rats. The vascular wall thickness/vascular diameter values of hypoxia treated pubs were increased compared with that of control newborns 7 days after birth; however, it decreased to similar levels than in the control group after 3 months, and then further decreased to significantly lower levels than in the control group at 6 months after birth. At birth, the lung tissues of newborns from hypoxic rats exhibited an increase in the levels of mRNA and proteins associated with PH such as HIF­1α, HIF­2α, V2R, TGF­ß, TNF­α, Ang­2 and α­SMA. At 3 and 6 months after birth, the levels of both V2R mRNA and protein in offspring from hypoxic rats were at least 2­fold higher, whereas the expression of all other factors decreased compared with the control offspring. By contrast, HIF­2α and Ang­2 expression levels were significantly increased in the 6­month­old control offspring from normoxic rats. V2R overexpression in pups induced by hypoxia in maternal rats was sustained until their adulthood. V2R may be a marker for detecting PH.


Assuntos
Hipóxia Fetal/complicações , Hipertensão Arterial Pulmonar/metabolismo , Receptores de Vasopressinas/genética , Receptores de Vasopressinas/metabolismo , Regulação para Cima , Angiotensina II/genética , Angiotensina II/metabolismo , Animais , Animais Recém-Nascidos , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Biomarcadores/metabolismo , Modelos Animais de Doenças , Feminino , Hipóxia Fetal/genética , Hipóxia Fetal/metabolismo , Peso Fetal , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Masculino , Hipertensão Arterial Pulmonar/etiologia , Hipertensão Arterial Pulmonar/genética , Ratos , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
14.
Clin Obstet Gynecol ; 63(3): 601-606, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32516154

RESUMO

Despite its ubiquitous use, fetal heart rate (FHR) monitoring has not resulted in a significant reduction in hypoxic-ischemic encephalopathy following delivery. This manuscript reviews the reasons for this failure including limitations of FHR to accurately predict hypoxia, low prevalence of hypoxic-ischemic encephalopathy, and lack of standardization of interpretation and intervention. We propose an alternative goal for FHR monitoring during labor to provide optimal care by early identification of truly concerning features, initiation of appropriate interventions, clear documentation of concerns and plans, and clear communication between team members on labor and delivery, including initiation of the chain of command as needed.


Assuntos
Hipóxia Fetal , Monitorização Fetal , Frequência Cardíaca Fetal/fisiologia , Hipóxia-Isquemia Encefálica , Trabalho de Parto/fisiologia , Diagnóstico Precoce , Feminino , Hipóxia Fetal/complicações , Hipóxia Fetal/diagnóstico , Hipóxia Fetal/fisiopatologia , Monitorização Fetal/métodos , Monitorização Fetal/normas , Humanos , Hipóxia-Isquemia Encefálica/etiologia , Hipóxia-Isquemia Encefálica/prevenção & controle , Recém-Nascido , Gravidez
15.
Cell Mol Neurobiol ; 40(5): 737-750, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31916069

RESUMO

Neonatal hypoxic-ischemic encephalopathy (HIE) is a major cause of lifelong disabilities worldwide, without effective therapies and clear regulatory mechanisms. MicroRNAs (miRNAs) act as a significant regulator in neuroregeneration and neuronal apoptosis, thus holding great potential as therapeutic targets in HIE. In this study, we established the hypoxia-ischemia (HI) model in vivo and oxygen-glucose deprivation (OGD) model in vitro. Zea-longa score and magnetic resonance imaging were applied to verify HI-induced neuronal dysfunction and brain infarction. Subsequently, a miRNA microarray analysis was employed to profile miRNA transcriptomes. Down-regulated miR-124 was found 24 h after HIE, which corresponded to the change in PC12, SHSY5Y, and neurons after OGD. To determine the function of miR-124, mimics and lentivirus-mediated overexpression were used to regulate miR-124 in vivo and in vitro, respectively. Our results showed that miR-124 overexpression obviously promoted cell survival and suppressed neuronal apoptosis. Further, the memory and neurological function of rats was also obviously improved at 1 and 2 months after HI, indicated by the neurological severity score, Y-maze test, open field test, and rotating rod test. Our findings showed that overexpression of miR-124 can be a promising new strategy for HIE therapy in future clinical practice.


Assuntos
Hipóxia Fetal/complicações , Hipóxia Fetal/terapia , Hipóxia-Isquemia Encefálica/prevenção & controle , Hipóxia-Isquemia Encefálica/fisiopatologia , MicroRNAs/metabolismo , Animais , Técnicas de Diagnóstico Neurológico , Encefalite/etiologia , Hipóxia Fetal/patologia , Glucose/deficiência , Hipóxia-Isquemia Encefálica/complicações , MicroRNAs/genética , Células PC12 , Ratos , Ratos Sprague-Dawley
16.
Am J Obstet Gynecol ; 222(1): 17-26, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31351061

RESUMO

Uterine contractions in labor result in a 60% reduction in uteroplacental perfusion, causing transient fetal and placental hypoxia. A healthy term fetus with a normally developed placenta is able to accommodate this transient hypoxia by activation of the peripheral chemoreflex, resulting in a reduction in oxygen consumption and a centralization of oxygenated blood to critical organs, namely the heart, brain, and adrenals. Providing there is adequate time for placental and fetal reperfusion between contractions, these fetuses will be able to withstand prolonged periods of intermittent hypoxia and avoid severe hypoxic injury. However, there exists a cohort of fetuses in whom abnormal placental development in the first half of pregnancy results in failure of endovascular invasion of the spiral arteries by the cytotrophoblastic cells and inadequate placental angiogenesis. This produces a high-resistance, low-flow circulation predisposing to hypoperfusion, hypoxia, reperfusion injury, and oxidative stress within the placenta. Furthermore, this renders the placenta susceptible to fluctuations and reduction in uteroplacental perfusion in response to external compression and stimuli (as occurs in labor), further reducing fetal capillary perfusion, placing the fetus at risk of inadequate gas/nutrient exchange. This placental dysfunction predisposes the fetus to intrapartum fetal compromise. In the absence of a rare catastrophic event, intrapartum fetal compromise occurs as a gradual process when there is an inability of the fetal heart to respond to the peripheral chemoreflex to maintain cardiac output. This may arise as a consequence of placental dysfunction reducing pre-labor myocardial glycogen stores necessary for anaerobic metabolism or due to an inadequate placental perfusion between contractions to restore fetal oxygen and nutrient exchange. If the hypoxic insult is severe enough and long enough, profound multiorgan injury and even death may occur. This review provides a detailed synopsis of the events that can result in placental dysfunction, how this may predispose to intrapartum fetal hypoxia, and what protective mechanisms are in place to avoid hypoxic injury.


Assuntos
Hipóxia Fetal/fisiopatologia , Feto/fisiologia , Placenta/fisiologia , Circulação Placentária/fisiologia , Contração Uterina/fisiologia , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/fisiopatologia , Feminino , Hipóxia Fetal/complicações , Feto/fisiopatologia , Humanos , Hipóxia-Isquemia Encefálica/etiologia , Hipóxia-Isquemia Encefálica/fisiopatologia , Trabalho de Parto/fisiologia , Isquemia Miocárdica/etiologia , Isquemia Miocárdica/fisiopatologia , Síndrome da Persistência do Padrão de Circulação Fetal/etiologia , Síndrome da Persistência do Padrão de Circulação Fetal/fisiopatologia , Placenta/fisiopatologia , Gravidez , Nascimento a Termo
17.
Physiol Res ; 69(Suppl 4): S649-S659, 2020 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-33656908

RESUMO

The healthy development of the fetus depends on the exact course of pregnancy and delivery. Therefore, prenatal hypoxia remains between the greatest threats to the developing fetus. Our study aimed to assess the impact of prenatal hypoxia on postnatal development and behavior of the rats, whose mothers were exposed to hypoxia (10.5 % O2) during a critical period of brain development on GD20 for 12 h. This prenatal insult resulted in a delay of sensorimotor development of hypoxic pups compared to the control group. Hypoxic pups also had lowered postnatal weight which in males persisted up to adulthood. In adulthood, hypoxic males showed anxiety-like behavior in the OF, higher sucrose preference, and lower levels of grimace scale (reflecting the degree of negative emotions) in the immobilization chamber compared to the control group. Moreover, hypoxic animals showed hyperactivity in EPM and LD tests, and hypoxic females had reduced sociability compared to the control group. In conclusion, our results indicate a possible relationship between prenatal hypoxia and changes in sociability, activity, and impaired emotion regulation in ADHD, ASD, or anxiety disorders. The fact that changes in observed parameters are manifested mostly in males confirms that male sex is more sensitive to prenatal insults.


Assuntos
Comportamento Animal , Hipóxia Fetal/complicações , Efeitos Tardios da Exposição Pré-Natal , Córtex Sensório-Motor/crescimento & desenvolvimento , Equilíbrio Ácido-Base , Fatores Etários , Animais , Modelos Animais de Doenças , Feminino , Hipóxia Fetal/fisiopatologia , Preferências Alimentares , Idade Gestacional , Masculino , Aprendizagem em Labirinto , Atividade Motora , Gravidez , Ratos Wistar , Reflexo de Sobressalto , Fatores Sexuais , Interação Social
18.
Sci Rep ; 9(1): 18049, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31792231

RESUMO

Schizophrenia (SZ) is a multifactorial mental disorder, which has been associated with a number of environmental factors, such as hypoxia. Considering that numerous neural mechanisms depends on energetic supply (ATP synthesis), the maintenance of mitochondrial metabolism is essential to keep cellular balance and survival. Therefore, in the present work, we evaluated functional parameters related to mitochondrial function, namely calcium levels, mitochondrial membrane potential, redox homeostasis, high-energy compounds levels and oxygen consumption, in astrocytes from control (Wistar) and Spontaneously Hypertensive Rats (SHR) animals exposed both to chemical and gaseous hypoxia. We show that astrocytes after hypoxia presented depolarized mitochondria, disturbances in Ca2+ handling, destabilization in redox system and alterations in ATP, ADP, Pyruvate and Lactate levels, in addition to modification in NAD+/NADH ratio, and Nfe2l2 and Nrf1 expression. Interestingly, intrauterine hypoxia also induced augmentation in mitochondrial biogenesis and content. Altogether, our data suggest that hypoxia can induce mitochondrial deregulation and a decrease in energy metabolism in the most prevalent cell type in the brain, astrocytes. Since SHR are also considered an animal model of SZ, our results can likewise be related to their phenotypic alterations and, therefore, our work also allow an increase in the knowledge of this burdensome disorder.


Assuntos
Astrócitos/patologia , Hipóxia Celular , Hipóxia Fetal/complicações , Mitocôndrias/patologia , Esquizofrenia/patologia , Trifosfato de Adenosina/metabolismo , Animais , Animais Recém-Nascidos , Astrócitos/citologia , Encéfalo/citologia , Encéfalo/patologia , Sobrevivência Celular , Células Cultivadas , Modelos Animais de Doenças , Metabolismo Energético , Feminino , Hipóxia Fetal/patologia , Humanos , Masculino , Potencial da Membrana Mitocondrial , Mitocôndrias/metabolismo , Oxirredução , Consumo de Oxigênio , Gravidez , Cultura Primária de Células , Ratos , Ratos Endogâmicos SHR , Esquizofrenia/etiologia
19.
J Dermatol ; 46(10): 849-852, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31418467

RESUMO

Infantile hemangioma is one of the most common tumors in infancy. Delivery may be a clue for the trigger of infantile hemangioma formation in the head and face areas. In this study, we tried to plot localization of infantile hemangioma as well as capillary malformation on the head and face, and compared them to identify their characteristics and risk factors. The distribution of 104 lesions in 100 patients with infantile hemangioma was as follows: 32 lesions on the head, 12 on the forehead, 57 on the cheek and three in the jaw area. We could not find a statistically significant correlation of the distribution with three clinical subtypes (superficial, deep and mixed), sex or size of the lesions. However, the lesions in the jaw or chin areas were significantly less frequent than other areas (P = 0.0008 or 0.03, respectively). This tendency was not found in 40 patients with capillary malformation. Mechanical stress to jaw or chin areas may be less than other areas in normal cephalic delivery. Considering the emergence after birth and age-dependent involution of infantile hemangioma, we speculate that physiological events including perinatal hypoxia or mechanical stress during delivery as the trigger of hemangioma formation. Taken together, our results may reveal the contribution of mechanical stress to the trigger of infantile hemangioma, not capillary malformation, and may facilitate clinical differentiation between the two diseases by their localization. Further studies with an increased number of patients will be necessary to validate the finding.


Assuntos
Capilares/anormalidades , Hemangioma/diagnóstico por imagem , Neoplasias Cutâneas/diagnóstico por imagem , Análise Espacial , Malformações Vasculares/diagnóstico por imagem , Capilares/diagnóstico por imagem , Parto Obstétrico/efeitos adversos , Face , Feminino , Hipóxia Fetal/complicações , Cabeça , Hemangioma/etiologia , Humanos , Lactente , Japão , Masculino , Fotografação , Pele/diagnóstico por imagem , Neoplasias Cutâneas/etiologia , Distribuições Estatísticas , Estresse Mecânico
20.
Int J Mol Sci ; 20(10)2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-31137455

RESUMO

We investigated whether thrombin preconditioning of human Wharton's jelly-derived mesenchymal stem cells (MSCs) improves paracrine potency and thus the therapeutic efficacy of naïve MSCs against severe hypoxic ischemic encephalopathy (HIE). Thrombin preconditioning significantly enhances the neuroprotective anti-oxidative, anti-apoptotic, and anti-cytotoxic effects of naïve MSCs against oxygen-glucose deprivation (OGD) of cortical neurons in vitro. Severe HIE was induced in vivo using unilateral carotid artery ligation and hypoxia for 2 h and confirmed using brain magnetic resonance imaging (MRI) involving >40% of ipsilateral hemisphere at postnatal day (P) 7 in newborn rats. Delayed intraventricular transplantation of 1 × 105 thrombin preconditioned but not naïve MSCs at 24 h after hypothermia significantly enhanced observed anti-inflammatory, anti-astroglial, and anti-apoptotic effects and the ensuing brain infarction; behavioral tests, such as cylinder rearing and negative geotaxis tests, were conducted at P42. In summary, thrombin preconditioning of human Wharton's jelly-derived MSCs significantly boosted the neuroprotective effects of naïve MSCs against OGD in vitro by enhancing their anti-oxidative, anti-apoptotic, and anti-cytotoxic effects, and significantly attenuated the severe HIE-induced brain infarction and improved behavioral function tests in vivo by maximizing their paracrine anti-inflammatory, anti-astroglial, and anti-apoptotic effects.


Assuntos
Hipóxia-Isquemia Encefálica/terapia , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Trombina/farmacologia , Animais , Apoptose , Hipóxia Celular , Células Cultivadas , Hipóxia Fetal/complicações , Humanos , Hipóxia-Isquemia Encefálica/etiologia , Recém-Nascido , Masculino , Ratos , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...