• Title/Summary/Keyword: BRAIN DEATH

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Cadmium induces neurotoxicity via activation of JNK and c-JUN in human neuroblastoma cell

  • Kim, Sun-Don;Moon, C.K.;Jo, Sang-Mee
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.182.1-182.1
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    • 2003
  • Occupational exposure to cadmium (Cd) can result in brain disorders and olfactory dysfunction is the most well-known symptom. Recently Cd has been shown to induce apoptosis by activating MAPKs in various cell types. However, intracellular signaling pathways of Cd-induced cytotoxicity in neuronal cells is not known well. Thus, in the present study, we studied role of JNK and its well-known downstream transcription factor, c-JUN, in Cd-induced neuronal cell death. (omitted)

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Attitudes of Hospice Volunteers towards Death with Dignity (호스피스 자원봉사자의 존엄사에 대한 태도요인)

  • Hwang, Byung-Deog
    • The Korean Journal of Health Service Management
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    • v.5 no.2
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    • pp.1-14
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    • 2011
  • The purpose of this study was analyzed the factors of influencing toward attitude to death with dignity to hospice volunteers. The data was collected for 21 days from 14 March to 3 April 2010. Among a total of 220 cases of the questionaries, only 195 cases were used. To data were analyzed by factor analysis, independent t-test, one-way anova and logistic regression using PASW statistics 18.0. The results were as follows; The attitudes towards death with dignity according to general characteristics was high in those with will to agreed to the passive euthanasia than those opposite to the attitude factors, namely, acceptive, the right to decide, negative, and dereliction of duty attitude factors. Significant variables for effects of death with dignity were gender, acceptive attitude factor and dereliction of duty attitude factors. Given that main provider of human organs is the brain-dead and we don't have enough organ donation, death with dignity should be linked with activating policy of organ donation, while solving donation shortage problem. This way, constructing social implementation and sharing consciousness on organ donation, would be diluting the bio-ethic controversies.

Naegleria fowleri Induces Jurkat T Cell Death via O-deGlcNAcylation

  • Lee, Young Ah;Kim, Kyeong Ah;Shin, Myeong Heon
    • Parasites, Hosts and Diseases
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    • v.59 no.5
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    • pp.501-505
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    • 2021
  • The pathogenic free-living amoeba Naegleria fowleri causes primary amoebic meningoencephalitis, a fatal infection, by penetrating the nasal mucosa and migrating to the brain via the olfactory nerves. N. fowleri can induce host cell death via lytic necrosis. Similar to phosphorylation, O-linked β-N-acetylglucosamine (O-GlcNAc) glycosylation (O-GlcNAcylation) is involved in various cell-signaling processes, including apoptosis and proliferation, with O-GlcNAc addition and removal regulated by O-GlcNAc transferase and O-GlcNAcase (OGA), respectively. However, the detailed mechanism of host cell death induced by N. fowleri is unknown. In this study, we investigated whether N. fowleri can induce the modulation of O-GlcNAcylated proteins during cell death in Jurkat T cells. Co-incubation with live N. fowleri trophozoites increased DNA fragmentation. In addition, incubation with N. fowleri induced a dramatic reduction in O-GlcNAcylated protein levels in 30 min. Moreover, pretreatment of Jurkat T cells with the OGA inhibitor PUGNAc prevented N. fowleri-induced O-deGlcNAcylation and DNA fragmentation. These results suggest that O-deGlcNAcylation is an important signaling process that occurs during Jurkat T cell death induced by N. fowleri.

Mechanisms of 5-azacytidine-induced damage and repair process in the fetal brain

  • Ueno, Masaki
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2006.11a
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    • pp.55-64
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    • 2006
  • The fetal central nervous system (CNS) is sensitive to diverse environmental factors, such as alcohol, heavy metals, irradiation, mycotoxins, neurotransmitters, and DNA damage, because a large number of processes occur during an extended period of development. Fetal neural damage is an important issue affecting the completion of normal CNS development. As many concepts about the brain development have been recently revealed, it is necessary to compare the mechanism of developmental abnormalities induced by extrinsic factors with the normal brain development. To clarify the mechanism of fetal CNS damage, we used one experimental model in which 5-azacytidine (5AZC), a DNA damaging and demethylating agent, was injected to the dams of rodents to damage the fetal brain. 5AzC induced cell death (apoptosis)and cell cycle arrest in the fetal brain, and it lead to microencephaly in the neonatal brain. We investigated the mechanism of apoptosis and cell cycle arrest in the neural progenitor cells in detail, and demonstrated that various cell cycle regulators were changed in response to DNA damage. p53, the guardian of genome, played a main role in these processes. Further, using DNA microarray analysis, tile signal cascades of cell cycle regulation were clearly shown. Our results indicate that neural progenitor cells have the potential to repair the DNA damages via cell cyclearrest and to exclude highly affected cells through the apoptotic process. If the stimulus and subsequent DNA damage are high, brain development proceeds abnormally and results in malformation in the neonatal brain. Although the mechanisms of fetal brain injury and features of brain malformation afterbirth have been well studied, the process between those stages is largely unknown. We hypothesized that the fetal CNS has the ability to repair itself post-injuring, and investigated the repair process after 5AZC-induced damage. Wefound that the damages were repaired by 60 h after the treatment and developmental processes continued. During the repair process, amoeboid microglial cells infiltrated in the brain tissue, some of which ingested apoptotic cells. The expressions of genes categorized to glial cells, inflammation, extracellular matrix, glycolysis, and neurogenesis were upregulated in the DNA microarray analysis. We show here that the developing brain has a capacity to repair the damage induced by the extrinsic stresses, including changing the expression of numerous genes and the induction of microglia to aid the repair process.

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Effects of Glutamate Receptor Antagonists and Protein Synthesis Inhibitor on Delayed Neuronal Death Induced by Transient Global Ischemia in Rat Brain

  • Ko, Jun-Seog;Bae, Choon-Sang;Kim, Jong-Keun
    • The Korean Journal of Physiology and Pharmacology
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    • v.2 no.3
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    • pp.279-286
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    • 1998
  • It has been well documented that transient forebrain global ischemia causes selective neuronal degeneration in hippocampal CA1 pyramidal neurons with a delay of a few days. The mechanism of this delayed hippocampal CA1 pyramidal neuronal death (DND) is still controversial. To delineate the mechanisms of the DND, the effects of treatment with MK-801, an NMDA receptor antagonist, kynurenic acid, a NMDA/non-NMDA receptor antagonist, and/or cycloheximide, a protein synthesis inhibitor, on the DND were investigated in male Wistar rats. To examine the participation of apoptotic neuronal death in the DND, TUNEL staining was performed in ischemic brain section. Global ischemia was induced by 4-vessel occlusion for 20 min. All animals in this study showed the DND 3 and 7 days after the ischemic insult. The DND that occured 3 days and 7 days after the ischemia were not affected by pretreatment with MK-801 (1 mg/kg), but markedly attenuated by the pretreatment with kynurenic acid (500 mg/kg). Treatment with cycloheximide (1 mg/kg) also markedly inhibited the DND. The magnitudes of attenuation by the two drugs were similar. The magnitude of attenuation by co-treatments with kynurenic acid and cycloheximide was not greater than that with any single treatment. TUNEL staining was negative in the sections obtained 1 or 2 days after the ischemic insults, but it was positive at hippocampal CA1 pyramidal cells in sections collected 3 days after the ischemia. These results suggested that the DND should be mediated by the activation of non-NMDA receptor, not by the activation of NMDA receptor and that the activation of AMPA receptor should induce the apoptotic process in the DND.

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The Adult Guardianship and Medical Issue According to the Amendments of Civil Code (성년후견과 의료 -개정 민법 제947조의 2를 중심으로-)

  • Park, Ho-Kyun
    • The Korean Society of Law and Medicine
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    • v.13 no.1
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    • pp.125-153
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    • 2012
  • The adult guardianship system has been introduced through amendments of Korean Civil Code for the first time in the March 2011(Act No. 10429, 7. 1. 2013. enforcement). The adult guardianship system has the main purposes to provide a lot of help vulnerable adults and elderly, and protect them on the welfare related with property act, treatment, care, etc. There could be a controversy about whether the protection Legal Guardian's consent(formerly known as the Mental Health Act) or permission of the Family Court(revised Civil Code) are required to, or the Mental Health Act should be revised, when mental patient will be hospitalized forcibly. The author proposes that mental patient with Adult guardians should be determined by Legal Guardian's consent and approval of the Family Court, but mental patient without Adult guardians could be determined by Legal Guardian's consent. The issue of Withdrawing of life-sustaining treatment could be occurred due to the aging society and the development of modern medicine, and this has provided difficult, various problems to mankind in Legal, ethical, and social welfare aspects. The need of Death with dignity law or Natural death law has been reduced for a revision of the Civil Code. Therefore, on the issue of Withdrawing of life-sustaining treatment, in the future, intervention of the court is necessary in accordance with the revised Civil Code Section, and Organ Transplantation Act and the brain death criteria may serve as an important criterion.

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Modeling Survival in Patients With Brain Stroke in the Presence of Competing Risks

  • Norouzi, Solmaz;Jafarabadi, Mohammad Asghari;Shamshirgaran, Seyed Morteza;Farzipoor, Farshid;Fallah, Ramazan
    • Journal of Preventive Medicine and Public Health
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    • v.54 no.1
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    • pp.55-62
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    • 2021
  • Objectives: After heart disease, brain stroke (BS) is the second most common cause of death worldwide, underscoring the importance of understanding preventable and treatable risk factors for the outcomes of BS. This study aimed to model the survival of patients with BS in the presence of competing risks. Methods: This longitudinal study was conducted on 332 patients with a definitive diagnosis of BS. Demographic characteristics and risk factors were collected by a validated checklist. Patients' mortality status was investigated by telephone follow-up to identify deaths that may be have been caused by stroke or other factors (heart disease, diabetes, high cholesterol, etc.). Data were analyzed by the Lunn-McNeil approach at alpha=0.1. Results: Older age at diagnosis (59-68 years: adjusted hazard ratio [aHR], 2.19; 90% confidence interval [CI], 1.38 to 3.48; 69-75 years: aHR, 5.04; 90% CI, 3.25 to 7.80; ≥76 years: aHR, 5.30; 90% CI, 3.40 to 8.44), having heart disease (aHR, 1.65; 90% CI, 1.23 to 2.23), oral contraceptive pill use (women only) (aHR, 0.44; 90% CI, 0.24 to 0.78) and ischemic stroke (aHR, 0.52; 90% CI, 0.36 to 0.74) were directly related to death from BS. Older age at diagnosis (59-68 years: aHR, 21.42; 90% CI, 3.52 to 130.39; 75-69 years: aHR, 16.48; 90% CI, 2.75 to 98.69; ≥76 years: aHR, 26.03; 90% CI, 4.06 to 166.93) and rural residence (aHR, 2.30; 90% CI, 1.15 to 4.60) were directly related to death from other causes. Significant risk factors were found for both causes of death. Conclusions: BS-specific and non-BS-specific mortality had different risk factors. These findings could be utilized to prescribe optimal and specific treatment.

Protective Effects of Singihwan (腎氣丸) on Traumatic Brain Injury-induced Apoptosis in Rat Hippocampal Dentate Gyrus

  • Kwon, Oh-Bong;Song, Yun-kyung;Lim, Hyung-Ho
    • The Journal of Korean Medicine
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    • v.29 no.2
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    • pp.21-31
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    • 2008
  • Backgrounds: Singihwan is used "to strengthen inborn energy" and we suspected a protective effect on brain neuron cells. Objectives: The aim of this study was to evaluate the effects of Singihwan (SGH) on traumatic brain injury-induced delayed apoptosis in rat hippocampal dentate gyrus. Methods: For a surgical induction of traumatic brain injury (TBI), a 5 mm diameter stainless rod was used to make traumatic attack from the surface of the brain used by an impactor. The protective effect of the aqueous extract of SGH against TBI in the rat hippocampal dentate gyrus was investigated by using step-down avoidance task, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, Bax immunohistochemistry, and 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry. Results: The aqueous extract of SGH suppressed the TBI-induced increase in apoptosis and cell proliferation in the hippocampal dentate gyrus. Conclusions: It is possible that the aqueous extract of SGH has a neuroprotective effect on TBI-induced neuronal cell death.

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The Effects of Jujadokseo-hwan on the Activation of Brain and Neuroprotactive Effects (주자독서환의 뇌기능 활성 및 신경세포 보호효과)

  • Lee, Yu-Gyung;Chae, Jung-Won
    • The Journal of Pediatrics of Korean Medicine
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    • v.23 no.3
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    • pp.241-262
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    • 2009
  • Objectives This study is designed to investigate the effects of Jujadokseo-hwan on the brain ability and inducing oxidative stresses. Methods We measured the changes of regional cerebral blood flow and mean arterial blood pressure. Then we analyzed histological examination, immunohistochemistric response and anti-oxidant activity of Jujadokseo-hwan. Results 1. Treatment of Jujadokseo-hwan significantly increased regional cerebral blood flow but decreased mean arterial blood pressure. 2. Treatment of Jujadokseo-hwan-induced increase of regional cerebral blood flow was significantly inhibited by pretreatment with indomethacin (1 mg/kg, i.p.), an inhibitor of cyclooxygenase. 3. In histological examination through TTC stain, group I was no change, but group II showed that discolored in the most cortical part. Group III showed that decreased discolor in the cortical part. 4. In immunohistochemistric response of BDNF, group II showed that lower response effect. Group III showed that increase response effect. 5. Treatment of Jujadokseo-hwan increased proliferation rates of Glial cell effectively 6. Treatment of Jujadokseo-hwan accelerated proliferation rates of C6 cells in vitro. In addition, protective effects on cell death induced by paraquat, rotenone and hydrogen peroxide. In addition, activity of SOD were increased by treatment with Jujadokseo-hwan. Conclusions In conclusion, Jujadokseo-hwan can improve of the brain ability, learning ability, memory ability and induce ischemic brain injuries.

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Lipocalin-2 Secreted by the Liver Regulates Neuronal Cell Function Through AKT-Dependent Signaling in Hepatic Encephalopathy Mouse Model

  • Danbi Jo;Yoon Seok Jung;Juhyun Song
    • Clinical Nutrition Research
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    • v.12 no.2
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    • pp.154-167
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    • 2023
  • Hepatic encephalopathy (HE) associated with liver failure is accompanied by hyperammonemia, severe inflammation, depression, anxiety, and memory deficits as well as liver injury. Recent studies have focused on the liver-brain-inflammation axis to identify a therapeutic solution for patients with HE. Lipocalin-2 is an inflammation-related glycoprotein that is secreted by various organs and is involved in cellular mechanisms including iron homeostasis, glucose metabolism, cell death, neurite outgrowth, and neurogenesis. In this study, we investigated that the roles of lipocalin-2 both in the brain cortex of mice with HE and in Neuro-2a (N2A) cells. We detected elevated levels of lipocalin-2 both in the plasma and liver in a bile duct ligation mouse model of HE. We confirmed changes in cytokine expression, such as interleukin-1β, cyclooxygenase 2 expression, and iron metabolism related to gene expression through AKT-mediated signaling both in the brain cortex of mice with HE and N2A cells. Our data showed negative effects of hepatic lipocalin-2 on cell survival, iron homeostasis, and neurite outgrowth in N2A cells. Thus, we suggest that regulation of lipocalin-2 in the brain in HE may be a critical therapeutic approach to alleviate neuropathological problems focused on the liver-brain axis.