Role of the NF-kB/parkin/vegfr-1 pathway associated with hypoxic-ischemic insult in germinal matrix samples of newborn infants / O papel da via NF-kB/parkin/vegfr-1 associada à agressão hipóxico-isquêmica em amostras de matriz germinativa de pacientes recém-nascidos

Abstract Objective: Given the high proliferative activity of germinal matrix and its direct correlation with hypoxemia, it is necessary to investigate the possible molecular regulation pathways, to understand the existing clinical relationship between the hypoxic-ischemic insult and the biomarkers NF-kB, AKT-3, Parkin, TRK-C and VEGFR-1. Methods: A hundred and eighteen germinal matrix samples of the central nervous system of patients who died in the first 28 days of life were submitted to histological and immunohistochemistry analysis to identify the tissue immunoexpression of those biomarkers related to asphyxia, prematurity, and death events within 24h. Results: A significantly increased tissue immunoexpression of NF-kB, AKT-3 and Parkin was observed in the germinal matrix of preterm infants. In addition, significantly decreased tissue immunoexpression of VEGFR-1 and NF-kB was observed in patients who experienced asphyxia followed by death within 24 hours. Conclusions: The results suggest a direct involvement between the hypoxic-ischemic insult and NF-kB and VEGFR-1 markers since a decreased immunoexpression of these biomarkers was observed in asphyxiated patients. Furthermore, it is suggested that there was not enough time for VEGFR-1 to be transcribed, translated and expressed on the surface of the plasma membrane. This temporality can be observed in the relationship between NF-kB expression and the survival time of individuals who died within 24 hours, suggesting that this factor is essential for the production of VEGFR-1 and, therefore, to carry out the necessary remodeling effect to neovascularize the affected region.

RESUMO Objetivo: Dada a alta atividade proliferativa da matriz germinativa e sua correlação direta com a hipoxemia, é necessário investigar as possíveis vias de regulação molecular para entender a relação clínica existente entre o insulto hipóxico-isquêmico e os biomarcadores NF-kB, AKT -3, Parkina, TRK-C e VEGFR-1. Métodos: Cento e dezoito amostras de matriz germinativa do sistema nervoso central de pacientes que faleceram nos primeiros 28 dias de vida foram submetidas a análise histológica e imuno-histoquímica para identificar a imunoexpressão tecidual desses biomarcadores relacionados a eventos de asfixia, prematuridade e óbito em 24 horas. Resultados: Observou-se uma imunoexpressão tecidual significativamente aumentada de NF-kB, AKT-3 e Parkin na matriz germinativa de prematuros. Além disso, constatou-se uma imunoexpressão tecidual significativamente diminuída de VEGFR-1 e de NF-kB em pacientes que apresentaram asfixia seguida de morte em 24 horas. Conclusões: Os resultados sugerem o envolvimento direto entre o insulto hipóxico-isquêmico e os marcadores NF-kB e VEGFR-1, visto que se observou uma imunoexpressão diminuída destes biomarcadores nos pacientes asfixiados. Além disso, sugere-se que não houve tempo suficiente para que o VEGFR-1 fosse transcrito, traduzido e expresso na superfície da membrana plasmática. Essa temporalidade pode ser observada na relação entre a expressão de NF-kB e o tempo de vida dos indivíduos que morreram em 24 horas, o que sugere que esse fator é essencial para a produção do VEGFR-1 e, portanto, para realizar o efeito remodelador necessário para neovascularizar a região afetada.

Spectrum of MRI abnormalities in pediatric seizures

Background: Seizure is a pediatric emergency. Accurate determination of the etiology of seizures is very important to start an effective treatment. The study aims to determine the spectrum of Imaging abnormalities by Magnetic Imaging Resonance (MRI) in children who presented with seizures. Methods: It is a hospital-based prospective observational study which was carried out in Government Medical College and Rajindra Hospital, Patiala. This study included 50 pediatric patients in the age group between 0 months to 18 years who were referred to the Department of Radiodiagnosis for brain MRI between October 2017 to September 2019. Results: Neuroimaging abnormality was found in 19 (38%) cases. 31 (62%) patients had no abnormal finding. The most common imaging findings were inflammatory granuloma in 5 (10%) patients. Other findings were- Hypoxic-ischemic injury (HII) in 4 (8%), Mesial temporal sclerosis in 2(4%), cerebral atrophy in 1(2%), Hemorrhage in 1(2%), Tuberous sclerosis in 1(2%), Focal cortical dysplasia in 1(2%), Lissencephaly in 1 (2%), Joubert syndrome in 1(2%), and Arachnoid cyst in 1 (2%) patients. Conclusion: The MRI was able to identify brain lesions in 38% of pediatric patients who presented with seizures. The study revealed inflammatory granuloma as the commonest cause of seizures in children, followed by Hypoxic-Ischemic Injury. Early recognition of potentially treatable diseases helps in timely treatment and arrest of disease progression. It is recommended to use MRI as a primary investigation during the evaluation and management of pediatric seizures.

Neonatal Intracranial Ischemia and Hemorrhage : Role of Cranial Sonography and CT Scanning

OBJECTIVE: To evaluate the role of cranial sonography and computed tomography in the diagnosis of neonatal intracranial hemorrhage and hypoxic-ischemic injury in an Indian set-up. METHODS: The study included 100 neonates who underwent cranial sonography and computed tomography (CT) in the first month of life for suspected intracranial ischemia and hemorrhage. Two observers rated the images for possible intracranial lesions and a kappa statistic for interobserver agreement was calculated. RESULTS: There was no significant difference in the kappa values of CT and ultrasonography (USG) for the diagnosis of germinal matrix hemorrhage/intraventricular hemorrhage (GMH/IVH) and periventricular leucomalacia (PVL) and both showed good interobserver agreement. USG, however detected more cases of GMH/IVH (24 cases) and PVL (19) cases than CT (22 cases and 16 cases of IVH and PVL, respectively). CT had significantly better interobserver agreement for the diagnosis of hypoxic ischemic injury (HII) in term infants and also detected more cases (33) as compared to USG (18). CT also detected 6 cases of extraaxial hemorrhages as compared to 1 detected by USG. CONCLUSION: USG is better modality for imaging preterm neonates with suspected IVH or PVL. However, USG is unreliable in the imaging of term newborns with suspected HII where CT or magnetic resonance image scan is a better modality.

Changes of AIF (Apoptosis Inducing Factor) in the Basal Ganglia of Neonatal Rat Brain Induced by Hypoxic-ischemic Injury / 대한해부학회지

The caudate-putamen is generally referred to as the striatum or neostriatum, which is one of the main components of the basal ganglia and this designation, is especially relevant in the rat. In spite of the fact that it comprises one of the major parts in central nervous system, studies on how seriously vulnerable this area to cerebral ischemia especially in neonates is still remained. In this study, using neonatal (7 days postnatal) rats, we speculated the significance of AIF in the apoptotic neuronal cell death in basal ganglia induced by hypoxic-ischemic injury. For this study, we introduced permanent common carotid artery occlusion and then, exposed to 6% oxygen for 2 hours and the results are as follows: 1. There were tendency of increasing AIF immunoreactivity induced by hypoxic-ischemic insult in neonatal basal ganglia at 12 & 24 hrs after hypoxic-ischemic insult. 2. Western Blotting analysis showed increased AIF expression in basal ganglia at 12 hrs(caudate-putamen) & 24 hrs (globus pallidus) after hypoxic-ischemic insult. 3. Evidence of localization of AIF in glial cells as well as in neurons obtained by double-immunofluorescence staining. Our results seem to provide evidences on the involvement of AIF in the apoptotic neuronal cell loss with hypoxicischemic insult in neonatal rat. Furthermore, localization AIF in glial cells as well as in neurons suggests involvement of neuroglial cells in the apoptotic pathway in neonatal basal ganglia induced by hypoxic-ischemic injury.

Possible Neuroprotective Role of Exogenous Growth Hormone on Hypoxic-Ischemic Brain Injury in Neonatal Rats / 소아과

PURPOSE: This study was performed to evaluate the possible neuroprotective effect of exogenous growth hormone on hypoxic-ischemic brain injury in neonatal rats. METHODS: After ligation of the right common carotid artery, seven-day old Sprague-Dawley rats(n= 75) were exposed to 8% oxygen for two hours. In a growth hormone(GH)-treated group(n=25), each animal was subcutanously injected by GH(50 mg/kg, Grotrpin, Dong-Ah Pharmacy Co. KOREA) just before exposing to 8% oxygen, and then injected for the next two consecutive days by the same method. In a saline-treated group(n=25), the same amounts of saline were injected instead of GH. Other twenty five animals were sham-operated without hypoxia as a sham control group. The gross morphologic changes of extracted brains at three and seven days after injury were observed, and the ratios of wet and dry weight of each cerebral hemisphere ipsilateral and contralateral to hy poxic-ischemic injury were compared among three groups for evaluating the severity of brain edema. Also, the microscopic changes of cerebral cortex on coronal sections of paraffin-embedded brains were observed at three days after injury by light microscopy. RESULTS: The GH injection reduced the severities of gross changes at seven days after HI injury. The brain edemas of ipsilateral cerebral hemispheres to the site of ligation of the right common carotid artery were significantly decreased in GH-treated animals at three days after HI injury, compared to those in saline-treated animals(P<0.05). On light microscopic examination, neurons with pyknosis of nucleus were remarkably reduced on cerebral cortex at three days after hypoxic-ischemic injury by GH treatment. CONCLUSION: Exogenous GH might have a some neuroprotective role in hypoxic-ischemic brain injury of newborn rats.

The Effects of Excitatory Amino Acids and Their Receptors on Neuronal Damage of Rat Brain in Hypoxic-Ischemic Encephalopathy

Since the role of excitatory amino acids such as glutamate and aspartate and their receptors mediating cellular injury through various mechanisms were known in hypoxic-ischemic injury and associated diseases of central nervous system, blocking agents for transmitter release or receptors have been tried to reduce the cellular damages and subsequent sequelae experimentally. Several in vitro studies suggested two kinds of glutamate neurotoxicity: (1) rapid toxicity due to influx of sodium or chloride with resultant cellular edema and consequent damage, which is associated with N-methyl-D-Aspartate(NMDA) as well as non-NMDA receptors, (2) calcium mediated delayed toxicity associated mainly with NMDA receptor. This study was conducted to investigate the role of rapid toxicity in hypoxic-ischemic injury. Early lesions of 30 minutes to 24 hours after hypoxic-ischemic insult were examined by autoradiography with radiolabelled glutamate and kainitic acid (KA) as well as light and electron microscopy. Late changes were evaluated on formaldehyde-acetic acid-methanol(FAM) fixed brain 1 week after the insult. Cornus ammonis(CA) l of hippocampus showed the highest density of NMDA receptors, which was decreased constantly from 2 hours to 24 hours. In contrast, CA3 of hippocampus showed the highest density of KA receptors, which was the lowest at 6 hour and increased thereafter. Light microscopic examination showed the worst changes during 30 minutes to 6 hours. After 1 week, most of the cases showed degeneration of neurons and CAI and CA3 did not show the difference. Electron microscopic examination showed marked degenerative changes of neurons as well as neuropils starting from 30 minutes after the insult. In conclusion, rapid toxicity mediated by non-NMDA(KA) receptor seen in CA3 lead to permanent damage in 1 week old lesion.