Publications by authors named "Yeon Kyeong Lee"
Article Synopsis
- The release of radionuclides from nuclear activities and natural sources can contaminate aquatic ecosystems, leading to long-term exposure to ionizing radiation for organisms, potentially threatening their survival.
- In a study, Atlantic salmon embryos were exposed to varying gamma radiation dose rates (1 to 30 mGy·h) from fertilization to hatching; results showed that higher radiation doses led to increased mortality, DNA damage, and developmental issues, particularly in eye and brain tissues.
- Significant negative effects on fish development, including delayed hatching and reduced antioxidant enzyme activity, were observed at dose rates exceeding 10 mGy·h, demonstrating the harmful impact of chronic radiation exposure on aquatic life. *
Article Synopsis
- The Chernobyl Nuclear Power Plant accident in 1986 caused severe damage to surrounding Scots pine trees due to high levels of ionizing radiation, leading to tree death and subsequent replanting efforts.
- Over 30 years later, radiation levels remain elevated but have decreased significantly, with ongoing research investigating the health of Scots pine in areas with varying radiation exposure.
- Findings indicate that trees in high and medium radiation areas exhibit notable DNA damage, cellular abnormalities, and increased antioxidant compounds, highlighting the long-lasting impact of radiation on forest ecosystems in the Exclusion Zone.
Article Synopsis
- The study examines how de-methyl esterification of homogalacturonan, combined with calcium cross-linking, may improve freezing survival in cold-acclimated plants by making their cell walls less porous.
- Japanese bunching onion leaves showed an 8 °C increase in freezing survival and a significant reduction in tissue permeability after two weeks of cold acclimation, linked to higher pectin methylesterase activity and lower homogalacturonan methylation.
- Treatment with calcium chloride in non-acclimated plants increased certain cell wall components and decreased visible pores, but did not enhance survival to freezing; rather, it aided in ice nucleation reduction to levels seen in cold-acclimated plants.*
COVID-19 vaccine safety monitoring in the Republic of Korea: February 26, 2021 to April 30, 2021.
Osong Public Health Res Perspect
August 2021
Article Synopsis
- COVID-19 vaccination began in Korea on February 26, 2021, targeting high-priority groups, with AstraZeneca and Pfizer-BioNTech vaccines available.
- From February 26 to April 30, 2021, there were 16,196 reports of adverse events after administering 3,586,814 doses, with 96.7% being non-serious, while 3.3% were serious including 73 deaths, none linked to the vaccines.
- The majority of adverse events (80.7%) occurred in women, with common side effects like myalgia, fever, and headache, and ongoing monitoring of vaccine safety is being conducted by the Korea Disease Control and Prevention Agency.
Article Synopsis
- South Korea's mass vaccination campaign from February 26 to April 30, 2021, administered 3.8 million COVID-19 vaccine doses.
- Out of 173 suspected anaphylaxis cases reported, 44 were confirmed as actual anaphylaxis using established case definitions.
- The rates of anaphylaxis were 18.2 per million doses for Vaxzevria and 6.2 per million for Comirnaty, with symptoms typically appearing 14 minutes after vaccination, and most patients had recovered by the time of review.
Article Synopsis
- - A national immunization program is crucial for preventing diseases and reducing mortality from vaccine-preventable diseases (VPD).
- - An analysis from 2001 to 2016 showed 13 confirmed cases of vaccine-related anaphylaxis in Korea, mainly in children, with the highest incidence in 2015.
- - Although vaccine-related anaphylaxis is rare, healthcare professionals need to remain vigilant about the possibility of such reactions.
Article Synopsis
- * The research used both lab tests and computational methods to study the effects of UVB on crustaceans, focusing on a specific species to measure its impact at different biological levels.
- * A novel network of quantitative adverse outcome pathways (qAOPs) was created using experimental data and existing information, providing a structured framework that could be useful for assessing both chemical and nonchemical stressors in the future.
Article Synopsis
- Ionizing radiation can cause oxidative stress, DNA damage, and epigenetic changes in aquatic organisms, which can either help them adapt or lead to negative effects.
- A study exposed adult Daphnia magna to different levels of Co gamma radiation and analyzed various biological responses at molecular, cellular, and organismal levels.
- Findings revealed increased global DNA methylation and changes in gene expression and reactive oxygen species over time, but no significant impact on overall fecundity, leading to a proposed model for understanding how epigenetic mechanisms respond to low-dose radiation stress.
Article Synopsis
- - The study investigates the effects of high-energy gamma radiation on Daphnia magna, a type of freshwater crustacean, examining multiple biological levels from molecular to individual impacts.
- - Key findings include the identification of complex, non-linear responses to radiation exposure and the characterization of toxicity pathways that impair reproduction, including DNA damage and lipid peroxidation.
- - The research proposes three new Adverse Outcome Pathways (AOPs) that connect oxidative stress mechanisms to reproductive effects, emphasizing the need for a mechanistic understanding of gamma radiation's impact on aquatic organisms.
Article Synopsis
- The study investigates the effects of gamma radiation on three plant species: Norway spruce, Scots pine, and Arabidopsis thaliana, revealing that conifers are more sensitive to radiation compared to the herbaceous A. thaliana.
- High doses of gamma radiation (≥40 mGy h) significantly inhibited growth in the conifers, causing visible damage and mortality, while A. thaliana only displayed delayed root development at much higher doses (≥100 mGy h) without significant damage.
- All species experienced dose-dependent DNA damage, but the conifers showed more persistent adverse effects at the cellular and organismal level, indicating a lower tolerance to DNA damage compared to Arabidopsis thaliana.
Article Synopsis
- - A study examined how UV-B radiation affects Scots pine seedlings' tolerance to gamma radiation, focusing on whether previous UV-B exposure helps seedlings acclimatize to low-moderate gamma radiation levels.
- - Results showed that gamma radiation significantly harmed the seedlings by increasing reactive oxygen species, reducing shoot and root length, and causing DNA damage, regardless of whether they were pre-exposed to UV-B.
- - Ultimately, no protective effect of UV-B against gamma radiation was found; any negative effects of both types of radiation on growth and DNA damage persisted for weeks but began to reverse after eight months.
Chelidonine Induces Caspase-Dependent and Caspase-Independent Cell Death through G Arrest in the T98G Human Glioblastoma Cell Line.
Evid Based Complement Alternat Med
May 2019
Article Synopsis
- Greater celandine, a plant from the Papaveraceae family, is recognized for its potential health benefits.
- It has been studied for its antibacterial and anticancer properties.
- Chelidonine, a functional metabolite derived from the plant, is specifically noted for its therapeutic effects.
Article Synopsis
- Researchers developed a new method to quantitatively measure auxin levels in plant tissues by combining cryosectioning, freeze-drying, and laser microdissection (LMD), enabling high precision and minimal tissue use.
- This method enhances the preservation of plant materials, preventing auxin degradation, which is crucial for accurate measurement of the hormone indole-3-acetic acid (IAA).
- The technique allows collection of tissue samples in a short time frame (around 4 hours) and can be applied to other small molecule analyses requiring high specificity and preservation of biological compounds.
Article Synopsis
- NDRG2 downregulation is linked to cancer progression and poor outcomes but may enhance chemotherapy sensitivity when induced by p53.
- This study focuses on NDRG2's role in increasing sensitivity to cisplatin in U937 lymphoma cells lacking functional p53.
- NDRG2 enhances cisplatin sensitivity by adjusting the BAK-to-Mcl-1 ratio via the NOX5-ROS-PKR pathway, suggesting its potential as a target for improving cancer treatment effectiveness.
Article Synopsis
- * In the crown region of buds, SDs lead to changes in cell wall composition, making them less permeable to water, which helps prevent dehydration in winter buds.
- * Upon returning to LD conditions, these changes are reversed, allowing for increased water transport and signaling the end of dormancy in the buds.
Article Synopsis
- - The study analyzed adverse events following immunization (AEFI) and compensation claims in Korea from 2011 to 2016, revealing an average of 278 reported AEFI cases annually, including 31 deaths, but no direct link to vaccinations was established.
- - The bacillus Calmette-Guérin (BCG) vaccine had the highest reporting rate for AEFI (20.8 cases per 100,000 doses) and was most commonly associated with injury compensation claims (50% of total claims), with a high compensation rate of 96% for BCG-related cases.
- - The research highlights the importance of maintaining a robust vaccine safety management system and timely responses to serious AEFI to uphold public
Article Synopsis
- Adverse events during mass vaccination campaigns can significantly lower vaccine coverage, making it essential to identify characteristics of psychogenic illness cases that require further intervention.
- The study analyzed reports of psychogenic illnesses from a vaccination campaign against H1N1 in Korea in 2009, focusing on cases that were confirmed by health authorities.
- Findings indicated that most affected individuals were female adolescents, and these cases led to lengthy hospital stays and high medical costs, highlighting the need for awareness and planning in future vaccination efforts.
Article Synopsis
- * The study examined Arabidopsis thaliana mutants to understand how different combinations of day and night temperatures (while keeping the average daily temperature constant) affect the timing of floral induction.
- * Results showed that lower daytime temperatures led to faster flowering due to increased expression of key floral genes (FT and LFY), and indicated that the circadian clock protein LHY is important for this thermoperiodic response.
Article Synopsis
- The Def locus in pea seeds influences the abscission between the funicle and seed coat, requiring cell wall remodeling for this process.
- Researchers investigated changes in pectic polysaccharides in wild type and def mutant pea seeds using immunolabeling techniques to identify factors behind abscission.
- Results showed specific changes in pectic components during abscission, highlighting that de-methyl esterification may contribute to the remodeling necessary for seed separation, as seen in the different patterns of labeling in dominant and recessive lines.
Article Synopsis
- The study investigates the effectiveness of low temperature treatment combined with meristem culture to eliminate Chrysanthemum stunt viroid (CSVd) from infected Argyranthemum plants, focusing on two cultivars: 'Border Dark Red' and 'Yellow Empire'.
- While some CSVd-free plants were successfully produced in 'Border Dark Red', the treatment was ineffective for 'Yellow Empire', indicating varied responses between the cultivars.
- The research also found that CSVd persists in the flowers and stems of both cultivars but does not transmit via seeds, providing insights into the viroid's distribution and potential methods for creating viroid-free plants.
Article Synopsis
- A study showed that during embryogenesis in Norway spruce, several epigenetic regulators are expressed differently based on temperature conditions, affecting their epigenetic memory.
- Key mechanisms involved include DNA and histone methylation and small RNAs, with significant transcriptomic changes identified in over 10,000 genes due to temperature variations.
- The research suggests that Norway spruce has a larger variety of epigenetic regulatory genes compared to related species, which may enhance its ability to adapt to environmental changes.
Article Synopsis
- Abscission is a critical process in plants that affects crop yields and ornamental quality, and researchers are focused on understanding its regulation to enhance control over this process in agricultural settings.
- A study on poinsettia showcases a reliable method of inducing abscission through specific bud decapitation, revealing important gene expressions linked to the process, including six genes that are differentially expressed.
- Comparative analysis between poinsettias and pea mutants highlights significant differences in abscission characteristics, offering insights into evolutionarily conserved genes and mechanisms across vastly separated plant species.
Article Synopsis
- - Chrysanthemum stunt viroid (CSVd) is a harmful pathogen that affects Argyranthemum plants, and this study investigates its distribution in the plants' shoot apical meristems (SAM) and why certain cultivars are more susceptible.
- - Through techniques like in situ hybridization, researchers found that CSVd spreads differently among Argyranthemum cultivars: it fully invaded the SAM of 'Yellow Empire' and 'Butterfly' while being limited in 'Border Dark Red' and 'Border Pink'.
- - Differences in the invasion ability of CSVd are linked to the presence of callose deposits at plasmodesmata (PD) in SAM, with 'Yellow Empire' showing fewer deposits compared to 'Border
Article Synopsis
- - Young Norway spruce seedlings stop growing and set buds when exposed to short days, with temperature variations impacting dormancy and bud set timing, but the effects of alternating day and night temperatures are unclear.
- - Seedlings subjected to various day and night temperature combinations showed that night temperature significantly influences bud set and break, with higher daytime temperatures leading to delayed bud break, despite fast bud flush at intermediate night temperatures.
- - Time to bud burst decreases with longer short day exposure, indicating a threshold in bud development, and seedlings from different latitudes experience varying effects of low temperatures during bud development, with southern sources being more affected.
Article Synopsis
- Plants produce proteins like CaXEGIP1 to defend against microbial attacks, with this specific protein being isolated from pepper plants.
- CaXEGIP1 is activated during infection by certain pathogens and inhibits a specific glycoside hydrolase enzyme, helping enhance the plant's defense.
- Overexpression of CaXEGIP1 triggers cell death in pepper and Nicotiana plants, increases defense protein levels, and boosts resistance to other infections, highlighting its role in plant immunity.