Ischemic stroke causes severe neuronal damage. Chlorogenic acid is a phenolic substance present in fruits and coffee. It also exerts neuroprotective effects against various brain injuries. The 14-3-3 family protein perform a variety of functions including metabolism, signal transduction, cell differentiation, and apoptosis. The purpose of this study is to investigate whether chlorogenic acid regulates the expression of 14-3-3 protein in stroke animal models. Ischemic stroke was induced by middle cerebral artery occlusion (MCAO) surgery. Phosphate buffered saline (PBS) or chlorogenic acid (30 mg/kg) were intraperitoneally injected to adult male rats 2 h before MCAO surgery. Adhesive-removal test was performed 24 h after MCAO surgery and cerebral cortical tissues were collected for further study. MCAO damage caused severe neurological impairment and chlorogenic acid treatment ameliorated this disorder. Our proteomic approach showed a decrease in 14-3-3 expression in MCAO animals with PBS. The decrease in 14-3-3 expression alleviated in MCAO animal with chlorogenic acid. We confirmed changes in various 14-3-3 protein isoforms, including beta/alpha, zeta/delta, gamma, epsilon, eta, and tau through reverse transcription-PCR. These results explained that chlorogenic acid regulates the expression of 14-3-3 protein in MCAO-induced cerebral ischemia. 14-3-3 is considered to be an important protein for cell survival through binding to pro-apoptotic proteins. The maintenance of 14-3-3 levels is an important event in neuroprotection against ischemic injury. Therefore, we can demonstrate that the 14-3-3 protein contributes to the neuroprotective effect of chlorogenic acid in stroke animal models.
To analyze the radioactivity of 3H and 14C in miscellaneous radioactive wastes generated from nuclear power plants, a wet digestion method using sulfuric acid is currently used. However, sulfuric acid is classified as a special management material, and there is no disposal method for contaminated radioactive waste. Therefore, research on a thermal decomposition method that can analyze the DAW radioactive waste samples without using sulfuric acid is necessary. In this study, we will cover the final sample amount, sample injection method, and prevention of organic ignition to meet the minimum detection limit requirements of the analysis equipment. Through this research, optimal conditions for the thermal decomposition method for analyzing the radioactivity of 3H and 14C in DAW radioactive wastes generated from nuclear power plants can be derived.
Combustion method has been widely used in the analysis of 3H and 14C in various types of radioactive wastes since X. Hou reported the analysis of 3H and 14C in graphite and concrete for decommissioning of nuclear reactor. In this work, it was demonstrated that the validation result of combustion method for the simultaneous analysis of 3H and 14C in non-combustible radioactive wastes. To validate the combustion method, 3H and 14C spiked to sea sand and soil were prepared and each simulated sample was combusted with the accordance to a combustion temperature program. The validation of combustion method was assessed by the radioactivity recovery, radioactivity deviation, and relative standard deviation of measured radioactivity. The results of radioactivity recovery, radioactivity deviation, and relative standard deviation of 14C were 100~105%, less than 7%, less than 5%, respectively. In addition, 3H showed about 90% of radioactivity recovery, less than 20% of radioactivity deviation, and less than 5% of relative standard deviation. It will be provided that the validation results of combustion method in detail.
This study presents a rapid and quantitative sequential separation method for H-3 and C-14 isotopes with distillation apparatus in environmental samples released from nuclear facilities. After adding 200 mg of granulated potassium permanganate and 500 mg of sodium hydroxide in 100 mL of sample solution, the sample solution was heated until approximately 10 mL of distillate, and the distillate fraction was removed. The sample solution was heated again until a minimum 10 mL of additional distillate was collected. 10 mL of distillate was transferred to the LSC vail and the measurement sample for H-3 was made by adding 10 mL of Ultima Gold LLT to the LSC vial. After adding 2.5 g of potassium persulfate, 2 mL of 1M silver nitrate and 15 mL of concentrated nitric acid to the remained sample solution, the sample solution was heated for 90 minutes and C-14 isotopes were adsorbed into 10 mL of Carbo-Sorb solution in glass vial. The measurement sample for C-14 was made by adding 10 mL of Permafluor to the C-14 fraction in glass vial. The purified H-3 and C-14 samples were measured by the liquid scintillation counter after quenching correction. The average recoveries of H-3 and C-14 with CRM were measured to be 96% and 85%, respectively. The sequential separation method for H-3 and C-14 investigated in this study was applied to activated charcoal filter produced from nuclear power plants after validating the reliability by result of proficiency test (KOLAS-KRISS, PT-2021-51).
In this study, an aerosol process was introduced to produce CaCO3. The possibility of producing CaCO3 by the aerosol process was evaluated. The characteristics of CaCO3 prepared by the aerosol process were also evaluated. In the CaCO3 prepared in this study, as the heat treatment proceeded, the calcite phase disappeared. The portlandite phase and the lime phase were formed by the heat treatment. Even if the CO2 component is removed from the calcite phase, there is a possibility that the converted CO2 component could be adsorbed into the Ca component to form a calcite phase again. Therefore, in order to remove the calcite phase, carbon components should be removed first. The lime phase was formed when CO2 was removed from the calcite phase, while the portlandite phase was formed by the introducing of H2O to the lime phase. Therefore, the order in which each phase formed could be in the order of calcite, lime, and portlandite. The reason for the simultaneous presence of the portlandite phase and the lime phase is that the hydroxyl group (OH−) introduced by H2O was not removed completely due to low temperature and/or insufficient heating time. When the sufficient temperature (900°C) and heating time (60 min) were applied, the hydroxyl group (OH−) was removed to transform into lime phase. Since the precursor contained the hydrogen component, it could be possible that the moisture (H2O) and/or the hydroxyl group (OH−) were introduced during the heat treatment process.
This study examined the antioxidative and lipid accumulation inhibitory effects of 14 plants from Mongolia and Myanmar on 3T3-L1 and HepG2 cells. The total phenolic and flavonoid contents (TPC and TFC) of 14 plant extracts were measured, and the antioxidative activities were analyzed using DPPH, ABTS, FRAP, and ORAC. After measuring the pancreatic lipase levels and performing the thiobarbituric acid assay, the degree of lipid accumulation was determined by lipid (Oil Red O) staining and triglyceride assay in 3T3-L1 and HepG2 cells. M. paniculate (259.43 mgGAE/g) and C. benghalensis (130.78 mgNAE/g) had the highest TPC and TFC, respectively, among the 14 plants. R. acicularis Lindl. had the highest antioxidant activity in DPPH. The ABTS, FRAP, and ORAC results showed that the antioxidant activity of 11 species was higher than that of the positive control. The pancreatic lipase inhibitory effect of C. angustifolium Scop. was reduced to 23.65% at 0.1 mg/mL, and the level of lipid peroxidation of C. abrorescens Lam. was 0.63 nmol/mg. Five selected plants inhibited the lipid accumulation and triglyceride content, respectively, in 3T3-L1 and HepG2 cells. These results provide scientific evidence for developing functional foods using 14 plants from Mongolia and Myanmar, which have antioxidant activities and lipid accumulation reduction effects.
Stevioside, a natural sweeteners presently used in various kinds of food and food products in Korea, was evaluated for its toxicity potential in the 14 day feeding study using B6C3F1 mice. Stevioside was added to the diet at different concentrations of 0.31, 0.62, 1.25, 2.5 and 5%, and was administered for 14 consecutive days. An increase of liver organ weight in male mice was observed. No diet-related differences were noted in clinical signs, food consumption, and gross and histopatholgical evaluation. Based on these results, we concluded that the concentration of 5% in the diet was a suitable maximum tolerable dose of stevioside for a 90 day study in mice.
It has been suggested that Helicobacter pylori(H. pylori) infections can promote the development and progression of gastric cancer through the modulation of cell cycle regulators such as p27Kip1 and Skp2. p27Kip1 is a cyclin-dependent kinase (CDK) inhibitor that blocks the G1/S transition necessary for cell cycle progression. Skp2 is a component of the ubiquitin ligase complex called SCFSkp2(SKP1-Cullin-F-box), which specifically binds and promotes the degradation of p27Kip1. A low level of p27Kip1 and a high level of Skp2 have been reported in many types of cancers, including gastric cancer. In addition, a decrease in p27Kip1 has been reported in H. pylori-infected specimens. However, data on Skp2 in H. pylori infections are limited. This study examines the changes in the status of Skp2 in H. pylori-infected gastric epithelial AGS cells. For this, we stimulated AGS cells with H. pylori(NCTC 11637) at the ratio of 300:1(bacterium:cell) for 6 hours. The results of an immunoprecipitation analysis, followed by a western blot, indicate that the interaction between Skp2 and 14-3-3 was elevated 3 hours after the H. pylori treatment. In addition, there was an increase in cytoplasmic Skp2 after 3 hours, whereas there was no change in the nuclear level. Since it has been reported that interaction with 14-3-3 and the subsequent cytoplasmic translocation of Skp2 can increase its protein stability, increases in the interaction with 14-3-3 and the cytoplasmic Skp2 after the H. pylori treatment can increase the level of Skp2 in AGS cells. This phenomenon may explain, at least to some extent, the mechanism underlying the relationship between H. pylori infections and gastric carcinogenesis.
14-3-3 is a highly conserved, ubiquitously expressed protein family. It associates with diverse cellular proteins through its specific phosphoserine/phosphothreonine-binding activity and thus contributes to the regulation of crucial cellular processes such as metabolism, signal transduction, cell-cycle control, apoptosis, protein trafficking, transcription and stress responses. This study aims to determine changes in levels of 14-3-3 isoforms and 14-3-3 - associated proteins in Helicobacter pylori(H. pylori)-infected gastric epithelial AGS cells. AGS cells were stimulated with H. pylori(NCTC 11637) at the ratio of 300:1(bacterium:cell). Western blot analysis revealed that 14-3-3 σ was elevated at 3 hr after H. pylori treatment. Other isoforms were not significantly affected by H. pylori infection. Using immunoprecipitation to 14-3-3 σ, followed by proteomic analysis, we found that S phase kinase associated protein isoform 2 bound to 14-3-3 σ has increased. In contrast, three proteins (DEAD-box polypeptide 3, heterogeneous nuclear ribonucleoprotein H2 and WD repeat-containing protein isoform 1) bound to 14-3-3 decreased by H. pylori infection. Our results suggest that 14-3-3 may play an important regulatory role in H. pylori-induced signal transduction in gastric epithelial cells.
14-3-3 proteins are known to play a pivotal role in a diverse array of cellular events such as cell survival, apoptosis, and signal transduction. Numerous 14-3-3 ζ have been cloned and characterized from a host of eukaryotic organisms including human, plants, yeast, fruit fly and silkworm. However, no study on Spodoptera exigua 14-3-3ζ in conjunction with virus infection has so far been reported in insects. It appears that expression of Se14-3-3ζ was decreased starting 24 h post-SeNPV infection as SeNPV titers seemed to increase as evidenced by intense bands of SeNPV IAP3. Interestingly, confocal microscopic analysis revealed that Se14-3-3ζ is expressed at the apical side of the NPV-uninfected gut cells, whereas it was detected mainly in the nucleus of the NPV-infected cells. Thus, despite the biological significance of Se14-3-3ζ in S. exigua in conjunction with molecular interactions between SeNPV and S. exigua is unclear now, our data suggest that Se14-3-3 ζ protein plays a role to protect S. exigua from the infection or inhibit replication of SeNPV.