• BMB Reports
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• v.41 no.1
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• pp.1-10
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• 2008

Surgery, Chung-Ang Unviersity College of Medicine, Yong-San Hospital, Seoul, Korea Apoptosis is considered to be a programmed and controlled mode of cell death, whereas necrosis has long been described as uncontrolled and accidental cell death resulting from extremely harsh conditions. In the following review, we will discuss the features and physiological meanings as well as recent advances in the elucidation of the signaling pathways of both apoptotic cell death and programmed necrotic cell death.

• Journal of Microbiology and Biotechnology
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• v.32 no.12
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• pp.1547-1552
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• 2022

β-Amyrin is a pentacyclic triterpene widely distributed in leaves and stems worldwide. The ability of β-amyrin to induce the production of reactive oxygen species (ROS) in microorganisms suggests its potential as an antimicrobial agent. Thus, this study aimed to elucidate the antibacterial mode of action of β-amyrin. We treated Escherichia coli cells with β-amyrin and found that it triggered ROS accumulation. Excessive stress caused by ROS, particularly hydroxyl radicals, induces glutathione (GSH) dysfunction. GSH protects cells from oxidative and osmotic stresses; thus, its dysfunction leads to membrane depolarization. The resultant change in membrane potential leads to the release of apoptotic proteins, such as caspases. The activated caspases-like protein promotes the cleavage of DNA into single strands, which is a hallmark of apoptosis-like death in bacteria. Apoptotic cells usually undergo events such as DNA fragmentation and phosphatidylserine exposure, differentiating them from necrotic cells, and the cells treated with β-amyrin in this study were positive for annexin V and negative for propidium iodide, indicating apoptosis-like death. In conclusion, our findings suggest that the antibacterial mode of action of β-amyrin involves the induction of ROS, which resulted in apoptosis-like death in E. coli.

• Lingua Humanitatis
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• v.8
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• pp.129-150
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• 2006

According to John Newman's Bibliography of Imaginative Works about American Fighting in Vietnam, there are 1370 entries up to 1996 which deal with the theme of Vietnam War in literature. Among various themes such as war and gender/race and ethnicity/class, this study makes an issue of the contiguity between femininity and death in Vietnam War novels written by Americans to investigate one of the bedrocks upon which the western civilization is founded. Female figures, especially Oriental females are seen as an emblem of death in the novels such as The Thirteenth Valley, Close Quarters, Body Count, and Bamboo Bed. It has been found out that this kind of death obsessive mode of thinking is deeply embedded in Western mentality and argued that its habitual mode needs to be changed.

• Journal of Microbiology and Biotechnology
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• v.33 no.8
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• pp.992-997
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• 2023

Ferroptosis is a new kind of programmed cell death of which occurrence in microorganisms is not clearly verified. The elevated level of reactive oxygen species (ROS) influences cellular metabolisms through highly reactive hydroxyl radical formation under the iron-dependent Fenton reaction. Iron contributes to ROS production and acts as a cofactor for lipoxygenase to catalyze poly unsaturated fatty acid (PUFA) oxidation, exerting oxidative damage in cells. While ferroptosis is known to take place only in mammalian cells, recent studies discovered the possible ferroptosis-like death in few specific microorganisms. Capacity of integrating PUFA into intracellular membrane phospholipid has been considered as a key factor in bacterial or fungal ferroptosis-like death. Vibrio species in bacteria and Saccharomyces cerevisiae in fungi exhibited certain characteristics. Therefore, this review focus on introducing the occurrence of ferroptosis-like death in microorganisms and investigating the mode of action underlying the cells based on contribution of lipid peroxidation and iron-dependent reaction.

• YAKHAK HOEJI
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• v.57 no.4
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• pp.289-292
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• 2013

A total of 2,080 forensic autopsies in Seoul, Incheon and Gyeonggi province were performed by the National Forensic Service (NFS) in 2010. After analysing blood samples collected at autopsies by GC-MS and LC-MS/MS, the types and prevalence of drugs and poisons in blood were investigated using our laboratory information management system. Among 2,080 cases, 1,061 cases (51%) were positive for drugs and poisons. Surprisingly, antidepressants were identified in 137 cases which comprised 13% of the positive cases. Twelve different kinds of antidepressants were determined: Amitriptyline, fluoxetine, nortriptyline, trazodone, imipramine, mirtazapine, citalopram, venlafaxin, clomipramine, paroxetine, sertraline and bupropion. Amitriptyline was the most frequently detected antidepressant and was identified in 39 cases. Moreover, amitriptyline, fluoxetine, and nortriptyline were included in the list of the 20 most commonly encountered drugs or poisons in the analysis of blood collected at autopsies from 2007 to 2009, indicating the prevalence of their use. In this study, the 137 antidepressant-related deaths were classified by the mode of death to predict the prevalence of these drugs. As a result, those deaths were divided into four groups based on the cause and mode of death: 56 cases of suicide with fatal concentrations of antidepressant drugs in blood, 6 homicidal cases directly or indirectly related to antidepressants, 59 natural deaths with antidepressants detected in blood and 16 deaths caused by fire or other accidents with antidepressants detected in blood. Because incidents involving antidepressants have been increasing, especially in suicides or homicides, it is necessary for the health authorities and law enforcement administrations to cooperate and share the statistical data for curbing the abuse of antidepressants. This report is expected to provide the reference data related with antidepressants for the investigation of the deaths.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.6
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• pp.509-516
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• 2014

Radiation therapy for variety of human solid tumors utilizes mechanism of cell death after DNA damage caused by radiation. In response to DNA damage, cytochrome c was released from mitochondria by activation of pro-apoptotic Bcl-2 family proteins, and then elicits massive $Ca^{2+}$ release from the ER that lead to cell death. It was also suggested that irradiation may cause the deregulation of $Ca^{2+}$ homeostasis and trigger programmed cell death and regulate death specific enzymes. Thus, in this study, we investigated how cellular $Ca^{2+}$ metabolism in RKO cells, in comparison to radiation-resistant A549 cells, was altered by gamma (${\gamma}$)-irradiation. In irradiated RKO cells, $Ca^{2+}$ influx via activation of NCX reverse mode was enhanced and a decline of $[Ca^{2+}]_i$ via forward mode was accelerated. The amount of $Ca^{2+}$ released from the ER in RKO cells by the activation of $IP_3$ receptor was also enhanced by irradiation. An increase in $[Ca^{2+}]_i$ via SOCI was enhanced in irradiated RKO cells, while that in A549 cells was depressed. These results suggest that ${\gamma}$-irradiation elicits enhancement of cellular $Ca^{2+}$ metabolism in radiation-sensitive RKO cells yielding programmed cell death.

• Journal of The Korean Society of Clinical Toxicology
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• v.18 no.1
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• pp.11-17
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• 2020

Purpose: This study examines errors in death certificates (DCs) issued to cases of poisoning. Methods: DCs issued in poisoning cases were retrospectively reviewed. Errors in the DC were classified as major and minor errors, and were evaluated in accordance with their impact on the process of selecting the cause of death (COD). Results: A total of 79 DCs were evaluated; 43 (54.4%) DCs were issued in the emergency department (ED), and 36 (45.6%) DCs were issued outside the ED. The average major and minor errors per DC were determined to be 0.4 and 3.3, respectively. Moreover, an average of 3.0 errors were discovered in DCs issued at the ED, and 4.4 errors in DCs issued outside the ED. The most common major errors were incorrect manner of death (11.4%, 9/79), followed by unacceptable COD (7.6%, 6/79), and the mode of dying as an underlying COD (5.1%, 4/79). The common minor errors most frequently encountered were incorrect time interval (86.1%, 68/79), followed by incorrect other significant conditions (73.4%, 58/79), and no record for date of onset (62.0%, 49/79). Conclusion: Our results indicate that the total numbers of major errors, minor errors and cases of misjudged cause of death were greater in DCs issued outside the ED than in DCs issued at the ED. The most frequently quoted major error of DCs related to poisoning was determined to be the incorrect manner of death.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.1
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• pp.63-68
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• 2005

Hydrogen peroxide ($H_2O_2$) causes oxidative stress and is considered as an inducer of cell death in various tissues. Two-pore domain $K^+$ ($K_{2p}$) channels may mediate $K^+$ efflux during apoptotic volume decreases (AVD) in zygotes and in mouse embryos. In the present study, we sought to elucidate linkage between $K_{2p}$ channels and cell death by $H_2O_2$. Thus $K_{2p}$ channels (TASK-1, TASK-3, TREK-1, TREK-2) were stably transfected in HEK-293 cells, and cytotoxicity assay was preformed using cell counting kit-8 (CCK-8). Cell survival rates were calculated using the cytotoxicity assay data and dose-response curve was fitted to the $H_2O_2$ concentration. Ionic currents were recorded in cell-attached mode. The bath solution was the normal Ringer solution and the pipette solution was high $K^+$ solution. In HEK-293 cells expressing TREK-1, TREK-2, TASK-3, $H_2O_2$ induced cell death did not change in comparison to non-transfected HEK-293. In HEK-293 cells expressing TASK-1, however, dose-response curve was significantly shifted to the left. It means that $H_2O_2$ induced cell death was increased. In cell attached-mode recording, application of $H_2O_2$ (300μM) increased activity of all $K_{2p}$ channels. However, a low concentration of $H_2O_2$ ($50{\mu}M$) increased only TASK-1 channel activity. These results indicate that TASK-1 might participate in $K^+$ efflux by $H_2O_2$ at low concentration, thereby inducing AVD.

• Nuclear Engineering and Technology
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• v.49 no.6
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• pp.1211-1218
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• 2017

Monte Carlo neutron transport codes generally use the method of successive generations to converge the fission source distribution to-and then maintain it at-the fundamental mode. Recently, a phenomenon called "clustering" has been noted, which produces fission distributions that are very far from the fundamental mode. In this study, a mathematical model of clustering in Monte Carlo has been developed. The model draws on previous work for continuous-time birth-death processes, as well as methods from the field of population genetics.

• Journal of Biomedical Engineering Research
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• v.37 no.4
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• pp.134-139
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• 2016

US Food and Drug Administration (FDA) approved as a innovative cure for cancer, 1996. The effect is death of cancer cells through necrosis, apoptosis. Mainly the Continuous Wave mode (CW) use for PDT Laser. It sting, the question including itch, and etc. Reportedly, the increase of temperature with the perforated edema, ulcer, necrosis. The Thermal relaxation time and Oxygen recovery time is necessary. To give a normal oxygen recovery time of the cell, used Pulse mode. Progress, it was Burst Pulse mode when easing the thermal wake, the simplicity was secured, the PDT effect is good. Excepted in control group CW, Pulse, Burst pulse mode were incubated with various concentrations of 5-aminolevulinic acid hydrochloride (ALA-5). The tumor size reduction CW mode (44%), Pulse mode (48%), Burst pulse mode (53%) at 4 week after PDT with 0.3, 0.3, 0.3 mg/ml of ALA-5. After 4 hours, investigation of 100, 100, $100J/cm^2$ laser irradiation. The pulse mode was superior in expirimental data analysis. And it was the Burst pulse mode edge head of a family effect.