• Nuclear Medicine and Molecular Imaging
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• 제41권2호
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• pp.91-96
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• 2007

The measurement of pathologically low levels of tissue $pO_2$ is an important diagnostic goal for determining the prognosis of many clinically important diseases including cardiovascular insufficiency, stroke and cancer. The target tissues nowaday have mostly been tumors or the myocardium, with less attention centered on the brain. Radiolabelled nitroimidazole or derivatives may be useful in identifying the hypoxic cells in cerebrovascular disease or traumatic brain injury, and hypoxic-ischemic encephalopathy. In acute stroke, the target of therapy is the severely hypoxic but salvageable tissue. $^{18}F-MISO$ PET and $^{99}mTc-EC-metronidazole$ SPECT in patients with acute ischemic stroke identified hypoxic tissues and ischemic penumbra, and predicted its outcome. A study using $^{123}I-IAZA$ in patient with closed head injury detected the hypoxic tissues after head injury. Up till now these radiopharmaceuticals have drawbacks due to its relatively low concentration with hypoxic tissues associated with/without low blood-brain barrier permeability and the necessity to wait a long time to achieve acceptable target to background ratios for imaging in acute ischemic stroke. It is needed to develop new hypoxic marker exhibiting more rapid localization in the hypoxic region in the brain. And then, the hypoxic brain imaging with imidazoles or non-imidazoles may be very useful in detecting the hypoxic tissues, determining therapeutic strategies and developing therapeutic drugs in several neurological disease, especially, in acute ischemic stroke.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-1
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• pp.104-105
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• 2003

Hypoxic-ischemic (H-I) encephalopathy in the prenatal and perinatal period is a major cause of morbidity and mortality and often results in cognitive impairment, seizures, and motor impairment (cerebral palsy). Many studies of neonatal H-I brain injury have utilized the well characterized Levine model in which unilateral carotid ligation is followed by exposure to hypoxia. (omitted)

• Clinical and Experimental Pediatrics
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• 제64권12호
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• pp.608-618
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• 2021

Hypoxic-ischemic encephalopathy (HIE) is the most common cause of neonatal encephalopathy with a global incidence of approximately 1 to 8 per 1,000 live births. Neonatal encephalopathy can cause neurodevelopmental and cognitive impairments in survivors of hypoxic-ischemic insults with and without functional motor deficits. Normal neurodevelopmental outcomes in early childhood do not preclude cognitive and behavioral difficulties in late childhood and adolescence because cognitive functions are not yet fully developed at this early age. Therapeutic hypothermia has been shown to significantly reduced death and severe disabilities in term newborns with HIE. However, children treated with hypothermia therapy remain at risk for cognitive impairments and follow-up is necessary throughout late childhood and adolescence. Novel adjunctive neuroprotective therapies combined with therapeutic hypothermia may enhance the survival and neurodevelopmental outcomes of infants with HIE. The extent and severity of brain injury on magnetic resonance imaging might predict neurodevelopmental outcomes and lead to targeted interven tions in children with a history of neonatal encephalopathy. We provide a summary of the long-term cognitive outcomes in late childhood and adolescence in children with a history of HIE and the association between pattern of brain injury and neurodevelopmental outcomes.

• Clinical and Experimental Pediatrics
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• 제64권8호
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• pp.422-429
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• 2021

Background: Carnosine has antioxidative and neuroprotective properties against hypoxic-ischemic (HI) brain injury. Hypothermia is used as a therapeutic tool for HI encephalopathy in newborn infants with perinatal asphyxia. However, the combined effects of these therapies are unknown. Purpose: Here we investigated the effects of combined carnosine and hypothermia therapy on HI brain injury in neonatal rats. Methods: Postnatal day 7 (P7) rats were subjected to HI brain injury and randomly assigned to 4 groups: vehicle; carnosine alone; vehicle and hypothermia; and carnosine and hypothermia. Carnosine (250 mg/kg) was intraperitoneally administered at 3 points: immediately following HI injury, 24 hours later, and 48 hours later. Hypothermia was performed by placing the rats in a chamber maintained at 27℃ for 3 hours to induce whole-body cooling. Sham-treated rats were also included as a normal control. The rats were euthanized for experiments at P10, P14, and P35. Histological and morphological analyses, in situ zymography, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assays, and immunofluorescence studies were conducted to investigate the neuroprotective effects of the various interventional treatments. Results: Vehicle-treated P10 rats with HI injury showed an increased infarct volume compared to sham-treated rats during the triphenyltetrazolium chloride staining study. Hematoxylin and eosin staining revealed that vehicle-treated P35 rats with HI injury had decreased brain volume in the affected hemisphere. Compared to the vehicle group, carnosine and hypothermia alone did not result in any protective effects against HI brain injury. However, a combination of carnosine and hypothermia effectively reduced the extent of brain damage. The results of in situ zymography, TUNEL assays, and immunofluorescence studies showed that neuroprotective effects were achieved with combination therapy only. Conclusion: Carnosine and hypothermia may have synergistic neuroprotective effects against brain damage following HI injury.

• The Korean Journal of Physiology and Pharmacology
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• 제24권5호
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• pp.423-431
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• 2020

This study aimed to evaluate the effect of curcumin on brain hypoxic-ischemic (HI) damage in neonatal rats and whether the phosphoinositide 3-kinase (PI3K)/Akt/vascular endothelial growth factor (VEGF) signaling pathway is involved. Brain HI damage models were established in neonatal rats, which received the following treatments: curcumin by intraperitoneal injection before injury, insulin-like growth factor 1 (IGF-1) by subcutaneous injection after injury, and VEGF by intracerebroventricular injection after injury. This was followed by neurological evaluation, hemodynamic measurements, histopathological assessment, TUNEL assay, flow cytometry, and western blotting to assess the expression of p-PI3K, PI3K, p-Akt, Akt, and VEGF. Compared with rats that underwent sham operation, rats with brain HI damage showed remarkably increased neurological deficits, reduced right blood flow volume, elevated blood viscosity and haematocrit, and aggravated cell damage and apoptosis; these injuries were significantly improved by curcumin pretreatment. Meanwhile, brain HI damage induced the overexpression of p-PI3K, p-Akt, and VEGF, while curcumin pretreatment inhibited the expression of these proteins. In addition, IGF-1 treatment rescued the curcumin-induced down-regulated expression of p-PI3K, p-Akt, and VEGF, and VEGF overexpression counteracted the inhibitory effect of curcumin on brain HI damage. Overall, pretreatment with curcumin protected against brain HI damage by targeting VEGF via the PI3K/Akt signaling pathway in neonatal rats.

• 재활치료과학
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• 제7권1호
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• pp.11-26
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• 2018

목적 : 본 사례연구는 자살시도로 인한 저산소성 허혈성 뇌손상 환자의 특징적 증상과 신경학적 회복 양상을 고려한 인지 및 연하 재활 중심의 작업치료 중재를 소개하고 중재 효과로 인한 회복 양상에 대해 알아보고자 하였다. 연구방법 : 연구 대상은 자살시도로 인한 저산소성 허혈성 뇌손상을 진단받은 32세 남성으로 치료기간은 2016년 9월 8일부터 12월 6일까지이며, 주 5회 하루 한 번 재활치료를 받았다. 작업치료는 신경학적 기전으로 인한 저산소 허혈성 뇌손상의 특징과 자살이라는 정신 건강학적 특징을 바탕으로 이루어 졌으며, 인지와 연화 재활 중심의 프로그램이었다. 인지기능은 Mini Mental State Examination-Korean(MMSE-K), Computerized Neurocognitive Function Test(CNT), 일상생활활동 수준은 Korean-Modified Barthel Index(K-MBI), 연하기능은 Videofluoroscopic Dysphagia Scale(VDS), American Speech-Language-Hearing Association National Outcomes Measurements System (ASHA-NOMS)로 평가하였다. 결과 : 저산소성 허혈성 뇌손상 환자의 지연성 뇌손상 기전에 따라 인지기능 평가인 MMSE-K, CNT와 일상생활활동 수준을 평가하는 K-MBI, 연하기능을 평가하는 VDS, ASHA NOMS 결과에서 초기 평가 결과에 비해 모든 기능에서 저하가 나타났으나 회복 기전과 함께 재활 치료가 병행되며 모든 기능이 회복되어 초기 평가 수준으로 호전되었다. 결론 : 본 연구 결과 자살시도로 인한 심리적 요인과 저산소성 허혈성 뇌손상으로 인한 인지 및 연하적 요인을 고려한 일반적인 작업치료 프로그램은 환자에게 긍정적 회복 양상을 나타냈다. 이를 바탕으로 저산소성 허혈성 뇌손상으로 인한 지연성 뇌손상이 발생한 환자에게 작업치료의 개입은 필요한 부분이며, 정신건강과 인지 및 연하기능의 중심 프로그램이 개발되어야할 것이다.

• Clinical and Experimental Pediatrics
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• 제49권2호
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• pp.198-202
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• 2006

목 적 : Fas는 세포표면 수용체로 세포사멸 신호를 전도한다. 많은 질환에서 세포표면의 Fas가 Fas ligand(FasL)와 결합하여 세포사멸 과정을 유발하게 된다. 연구자들은 7일된 신생 흰쥐에 저산소성 허혈성 손상을 유발한 후 뇌 해마에서 Fas와 FasL의 발현을 관찰하고자 하였다. 방 법 : 7일된 신생 흰쥐를 오른쪽 총 경동맥 영구 결찰 후 8% 산소에 2시간 노출시켰다. 저산소성 허혈성 손상 후 12, 24, 48시간에 뇌를 적출 냉동 보관하였다. Western blotting 방법과 면역형광염색 방법으로 냉동 보관된 뇌의 경동맥을 결찰한 오른 쪽 해마에서 Fas와 FasL의 발현을 관찰하였다. 결 과 : Fas와 FasL의 발현은 저산소성 허혈성 손상 후 12시간에 경동맥이 결찰된 오른쪽 해마에서 크게 증가하고 이후 감소하는 것을 western blotting 방법에 의해 관찰하였다. Fas와 FasL의 면역형광발현은 오른쪽 해마의 CA1 영역에서 손상 후 12시간과 24시간에 대조군에 비해 증가하였다. Fas의 면역형광 발현은 손상 후 48시간에 감소하였으나 FasL의 면역형광발현은 손상 후 48시간에도 지속되었다. 결 론 : 세포표면에서 Fas와 FasL의 발현과 그들의 결합은 저산소성 허혈성 손상을 받은 미성숙 뇌의 신경세포 손상에 기여할 것으로 추측되었다.

• Journal of Korean Neurosurgical Society
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• 제58권1호
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• pp.22-29
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• 2015

Objective : Perinatal hypoxic-ischemic encephalopathy (HIE) and prolonged febrile seizures (pFS) are common neurologic problems that occur during childhood. However, there is insufficient evidence from experimental studies to conclude that pFS directly induces hippocampal injury. We studied cognitive function and histological changes in a rat model and investigated which among pFS, HIE, or a dual pathologic effect is most detrimental to the health of children. Methods : A rat model of HIE at postnatal day (PD) 7 and a pFS model at PD10 were used. Behavioral and cognitive functions were investigated by means of weekly open field tests from postnatal week (PW) 3 to PW7, and by daily testing with the Morris water maze test at PW8. Pathological changes in the hippocampus were observed in the control, pFS, HIE, and HIE+pFS groups at PW9. Results : The HIE priming group showed a seizure-prone state. The Morris water maze test revealed a decline in cognitive function in the HIE and HIE+pFS groups compared with the pFS and control groups. Additionally, the HIE and HIE+pFS groups showed significant hippocampal neuronal damage, astrogliosis, and volume loss, after maturation. The pFS alone induced minimal hippocampal neuronal damage without astrogliosis or volume loss. Conclusion : Our findings suggest that pFS alone causes no considerable memory or behavioral impairment, or cellular change. In contrast, HIE results in lasting memory impairment and neuronal damage, gliosis, and tissue loss. These findings may contribute to the understanding of the developing brain concerning conditions caused by HIE or pFS.

• Clinical and Experimental Pediatrics
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• 제53권10호
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• pp.898-908
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• 2010

Purpose: The neuroprotective effects of erythropoietin (EPO) have been recently shown in many animal models of brain injury, including hypoxic-ischemic (HI) encephalopathy, trauma, and excitotoxicity; however, limited data are available for such effects during the neonatal periods. Therefore, we investigated whether recombinant human EPO (rHuEPO) can protect against perinatal HI brain injury via an antiapoptotic mechanism. Methods: The left carotid artery was ligated in 7-day-old Sprague-Dawley (SD) rat pups ($in$ $vivo$ model). The animals were divided into 6 groups: normoxia control (NC), normoxia sham-operated (NS), hypoxia only (H), hypoxia+vehicle (HV), hypoxia+rHuEPO before a hypoxic insult (HE-B), and hypoxia+rHuEPO after a hypoxic insult (HE-A). Embryonic cortical neuronal cell culture of SD rats at 18 days gestation ($in$ $vitro$ model) was performed. The cultured cells were divided into 5 groups: normoxia (N), hypoxia (H), and 1, 10, and 100 IU/mL rHuEPO-treated groups. Results: In the $in$ $vivo$ model, Bcl-2 expressions in the H and HV groups were lower than those in the NC and NS groups, whereas those in the HE-A and HE-B groups were greater than those of the H and HV groups. The expressions of Bax and caspase-3 and the ratio of Bax/Bcl-2 were in contrast to those of Bcl-2. In the $in$ $vitro$ model, the patterns of Bcl-2, Bax, and caspase-3 expression and Bax/Bcl-2 ratio were similar to the results obtained in the in vivo model. Conclusion: rHuEPO exerts neuroprotective effect against perinatal HI brain injury via an antiapoptotic mechanism.

• The Journal of Korean Physical Therapy
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• 제15권4호
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• pp.199-207
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• 2003

신생아의 정상적인 발달을 저해하고 조기 사망의 주된 원인이 되고 있는 주산기 뇌손상에 관한 신경병리적 기전을 살펴보고자 하였다. 발달하고 있는 과정에서의 주산기 뇌손상은 주로 저산소성-허혈성 뇌손상과 출혈성 뇌손상에 의한 경우가 많다. 저산소성-허혈성 뇌손상과 관련하여 에너지 부전, 세포흥분독성, 미성숙 백질의 선택적 취약성을 고려해 볼 수 있다. 첫번째, 세포호흡에 관여하는 미토콘드리아의 손상과 관련하여 즉각적인 병리와 함께 지연된 양상의 손상을 보인다. 미토콘드리아의 호흡률이 감소하고 칼슘이온의 농도가 상승하여 세포 괴사 및 세포사멸 과정이 진행된다. 두번째, 흥분성 아미노산과 관련하여 미성숙한 뇌에는 NMDA 수용기-채널 복합체의 기능이 매우 풍부하고, phosphoinositide 가수분해가 높아서 흥분독성에 상당히 취약하다. 세 번째, 수초 형성에 중요한 역할을 하는 희돌기교세포가 주산기 뇌손상 특히, 저산소성-허혈성 손상에 취약하다. 희돌기교세포는 글루타메이트에 의한 자유유리기과 사이토카인 손상에 취약하다. 뇌출혈과 관련하여, 미성숙한 뇌는 뇌실 주위에 혈관층이 풍부하나 매우 약한 상태로 재관류 혹은 혈류의 증가로 인해 쉽게 파열된다. 특히 32주 이내인 경우 이러한 손상으로 인해 뇌실주위 백질연화증이 초래된다.