• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.343-349
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• 2022

We intend to use topic modeling to identify radiation-themed papers published from 1989 to 2022 and analyze the relevance and weight between topics. This study analyzed topics derived from national subjects for 717 papers published until recently in 2022 to contribute to the revitalization of research in the field of radiation. Through text mining, overall research trends on the subject distribution of the study were analyzed, and five topics were derived through topic modeling. First, among the papers to be analyzed, a total of 1,675 words were frequency-analyzed through the preprocessing process of key words in a total of 717 papers centered on keywords. Second, as a result of analyzing topics based on the association of constituent words for five topics, it was found that studies focused on minimizing dose in the range that does not degrade image quality in the fields of radiation, image, CT clinical. In addition, it was found that various studies were mainly conducted in the MRI, and the study of ultrasound in various areas of disease analysis was actively attempted.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2599-2605
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• 2022

The Korea Retrospective Dosimetry network (KREDOS) performed an inter-laboratory comparison to confirm the harmonization and reliability of the results of retrospective dosimetry using mobile phone. The mobile phones were exposed to ¹⁹²Ir while attached to the human phantoms in the field experiment, and the exposure doses read by each laboratory were compared. This paper describes the reference dosimetry performed to present the reference values for inter-comparison and to obtain additional information about the dose distribution. Reference dosimetry included both measurement using LiF:Mg,Cu,Si and calculation via MCNP simulation to allow a comparison of doses obtained with the two different methodologies. When irradiating the phones, LiF elements were attached to the phones and phantoms and irradiated at the same time. The comparison results for the front of the phantoms were in good agreement, with an average relative difference of about 10%, while an average of about 16% relative difference occurred for the back and side of the phantom. The differences were attributed to the different characteristics of the physical and simulated phantoms, such as anatomical structure and constituent materials. Nevertheless, there was about 4% of under-estimation compared to measurements in the overall linear fitting, indicating the calculations were well matched to the measurements.

• Journal of Veterinary Science
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• v.21 no.3
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• pp.35.1-35.11
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• 2020

Background: Despite common use of tylosin in turkeys, the pharmacokinetic (PK) data for this drug in turkeys is limited. Within a few months of growth, PK of drugs in turkeys undergoes changes that may decrease their efficacy due to variable internal exposure. Objectives: The objective of this study was to investigate the influence of age on the PK of a single intravenous (i.v.) and oral administration of tylosin to turkeys at a dose of 10 and 50 mg/kg, respectively. Methods: Plasma drug concentrations were measured using high-performance liquid chromatography with UV detection. The PK parameters were assessed by means of non-compartmental approach and were subjected to allometric analysis. Results: During a 2.5-month-long period of growth from 1.4 to 14.7 kg, the median value for area under the concentration-time curve after i.v. administration increased from 2.61 to 7.15 mg × h/L and the body clearance decreased from a median of 3.81 to 1.42 L/h/kg. Over the same time, the median elimination half-life increased from 1.03 to 2.96 h. For the oral administration a similar trend was noted but the differences were less pronounced. Bioavailability was variable (5.76%-21.59%) and age-independent. For both routes, the plasma concentration of the major tylosin metabolite, tylosin D, was minimal. Protein binding was age-independent and did not exceed 50%. Allometric analysis indicated a relatively poor predictivity of clearance, volume of distribution and elimination half-life for tylosin in turkeys. Conclusions: Age has a significant impact on tylosin PK in turkeys and dosage adjustment may be needed, particularly in young individuals.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.3030-3038
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• 2023

Nowadays, mobile robots have been used to search for uncontrolled radioactive source in indoor environments to avoid radiation exposure for technicians. However, in the indoor environments, especially in the presence of obstacles, how to make the robots with limited sensing capabilities automatically search for the radioactive source remains a major challenge. Also, the source search efficiency of robots needs to be further improved to meet practical scenarios such as limited exploration time. This paper proposes an automatic source search strategy, abbreviated as ACA: the location of source is estimated by a convolutional neural network (CNN), and the path is planned by the A-star algorithm. First, the search area is represented as an occupancy grid map. Then, the radiation dose distribution of the radioactive source in the occupancy grid map is obtained by Monte Carlo (MC) method simulation, and multiple sets of radiation data are collected through the eight neighborhood self-avoiding random walk (ENSAW) algorithm as the radiation data set. Further, the radiation data set is fed into the designed CNN architecture to train the network model in advance. When the searcher enters the search area where the radioactive source exists, the location of source is estimated by the network model and the search path is planned by the A-star algorithm, and this process is iterated continuously until the searcher reaches the location of radioactive source. The experimental results show that the average number of radiometric measurements and the average number of moving steps of the ACA algorithm are only 2.1% and 33.2% of those of the gradient search (GS) algorithm in the indoor environment without obstacles. In the indoor environment shielded by concrete walls, the GS algorithm fails to search for the source, while the ACA algorithm successfully searches for the source with fewer moving steps and sparse radiometric data.

• The Journal of Internal Korean Medicine
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• v.43 no.6
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• pp.1089-1104
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• 2022

Objective: The aim of this study was to identify the efficacy and underlying mechanism of cloves as an osteoarthritis (OA) treatment in a monosodium iodoacetate (MIA)-induced rat OA model. Osteoarthritis (OA) is nowadays one of the most prevalent degenerative joint diseases. Methods: Sprague-Dawley rats treated with MIA (50 μL; 80 mg/mL) were used as in vivo OA models. Cloves (100 and 200 mg/kg b.w.) were administered orally once daily for 2 weeks from 7 days after MIA injection. Changes in hindpaw weight distribution (HWD) were measured as a joint discomfort index. Activation markers related to inflammatory responses and cartilage degeneration in the right knee joints were evaluated by serum analysis and western blotting. Results: HWD decreased in the MIA control group but showed a dose-dependent elevation after clove treatment. Clove treatment inhibited inflammatory factors by PI3K/Akt/NF-κB signaling pathways, while also activating antioxidant factors through Sirt1/AMPK signaling pathways. Clove treatment also suppressed matrix metalloproteinase (MMP) overexpression and significantly increased the levels of tissue inhibitors of metalloproteinases (TIMPs). Conclusions: Treatment with cloves effectively reversed MIA-induced effects. Therefore, clove treatment could have the potential to protect against or treat OA.

• Biomolecules & Therapeutics
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• v.30 no.2
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• pp.151-161
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• 2022

This study elucidates the anti-cancer potential of gallic acid (GA) as a promising therapeutic agent that exerts its effect by regulating the PI3K/Akt pathway. To prove our research rationale, we used diverse experimental methods such as cell viability assay, colony formation assay, tumor spheroid formation assay, cell cycle analysis, TUNEL assay, Western blot analysis, xenograft mouse model and histological analysis. Treatment with GA inhibited cell proliferation in dose-dependent manner as measured by cell viability assay at 48 h. GA and cisplatin (CDDP) also inhibited colony formation and tumor spheroid formation. In addition, GA and CDDP induced apoptosis, as determined by the distribution of early and late apoptotic cells and DNA fragmentation. Western blot analysis revealed that inhibition of the PI3K/Akt pathway induced upregulation of p53 (tumor suppressor protein), which in turn regulated cell cycle related proteins such as p21, p27, Cyclin D1 and E1, and intrinsic apoptotic proteins such as Bax, Bcl-2 and cleaved caspase-3. The anti-cancer effect of GA was further confirmed in an in vivo mouse model. Intraperitoneal injection with GA for 4 weeks in an A549-derived tumor xenograft model reduced the size of tumor mass. Injection of them downregulated the expression of proliferating cell nuclear antigen and p-Akt, but upregulated the expression of cleaved caspase-3 in tumor tissues. Taken together, these results indicated that GA hindered lung cancer progression by inducing cell cycle arrest and apoptosis, suggesting that GA would be a potential therapeutic agent against non-small cell lung cancer.

• The Korean Journal of Physiology and Pharmacology
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• v.28 no.2
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• pp.153-164
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• 2024

This study aimed to identify metabolic biomarkers and investigate changes in intestinal microbiota in the feces of healthy participants following administration of Lactococcus lactis GEN-001. GEN-001 is a single-strain L. lactis strain isolated from the gut of a healthy human volunteer. The study was conducted as a parallel, randomized, phase 1, open design trial. Twenty healthy Korean males were divided into five groups according to the GEN-001 dosage and dietary control. Groups A, B, C, and D1 received 1, 3, 6, and 9 GEN-001 capsules (1 × 10¹¹ colony forming units), respectively, without dietary adjustment, whereas group D2 received 9 GEN-001 capsules with dietary adjustment. All groups received a single dose. Fecal samples were collected 2 days before GEN-001 administration to 7 days after for untargeted metabolomics and gut microbial metagenomic analyses; blood samples were collected simultaneously for immunogenicity analysis. Levels of phenylalanine, tyrosine, cholic acid, deoxycholic acid, and tryptophan were significantly increased at 5-6 days after GEN-001 administration when compared with predose levels. Compared with predose, the relative abundance (%) of Parabacteroides and Alistipes significantly decreased, whereas that of Lactobacillus and Lactococcus increased; Lactobacillus and tryptophan levels were negatively correlated. A single administration of GEN-001 shifted the gut microbiota in healthy volunteers to a more balanced state as evidenced by an increased abundance of beneficial bacteria, including Lactobacillus, and higher levels of the metabolites that have immunogenic properties.

• IMMUNE NETWORK
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• v.9 no.6
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• pp.236-242
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• 2009

Background: Melanoma is the most fatal form of skin cancer due to its rapid metastasis. Recently, several studies reported that selenium can induce apoptosis in melanoma cells. However, the precise mechanism remains to be elucidated. In this study, we investigated the effect of selenium on cell proliferation in murine melanoma and on tumor growth and metastasis in C57BL/6 mice. Methods: Cell proliferation was measured by MTT assay in selenium-treated melanoma cells. Cell cycle distribution was analysized by staining DNA with propidum iodide (PI). mRNA and protein expression related to cell cycle arrest was measured by reverse transcription PCR and western blot. Tumor growth and metastasis was measured by in vivo model. Results: Selenium was suppressed the proliferation of melanoma cells in a dose dependent manner. The growth inhibition of melanoma by selenium was associated with an arrest of cell cycle distribution at G0/G1 stage. The mRNA and protein level of CDK2/CDK4 was suppressed by treatment with selenium in a time-dependent manner. In vivo, tumor growth was not suppressed by selenium; however tumor metastasis was suppressed by selenium in mouse model. Conclusion: These results suggest that selenium might be a potent agent to inhibit proliferative activity of melanoma cells.

• Journal of the Korean Institute of Gas
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• v.20 no.2
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• pp.35-42
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• 2016

Formamide is a colorless fluid with ammonia odor, and irritable when inhaled. It has $LD_{50}$ value of > 5,577 mg/kg in rats for acute oral toxicity and NOAEL of 113 mg/kg/day for target organ (liver) of whole body toxicity. It is also known as reproductive toxicant (1B) and TWA(Time Weighted Average) for it is 10 ppm. Workplace measurements of work places dealing with formamide showed the ppm of all 25 samples was very lower than WEL. However, the exposure concentration can change, depending on workplace condition such as the intensity of work, operating local ventilation system, and wearing protection equipment (Respirators). Therefore, considering it with the risk of whole body toxicity and reproductive toxicity, exposure quantity of each imaginary scenario was calculated at 5.16, 1.72, and $0.43mg/m^3$. The average value was calculated at 0.02-0.58, 0.02-0.66 at 90 percent of cumulative distribution, 0.02-0.69 at 95 percent of cumulative distribution. Therefore, it was generally evaluated to be safe because all values were below 1. However, caution is required to prevent health hazard because it has hepatotoxicity and reproductive toxicity and risk of a high level momentary exposure, depending on the condition of workplace.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3581-3586
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• 2014

Aim: To investigate the effects of tetramethypyrazine (TMP) on proliferation and apoptosis of the human gastric carcinoma cell line 7901 and its possible mechanism of action. Methods: The viability of TMP-treated 7901 cells was measured with a 3-(4, 5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) and cell apoptosis was analyzed by flow cytometry. The distribution of cells in different phases of cell cycle after exposure of TMPs was analyzed with flow cytometry. To investigate the molecular mechanisms of TMP-mediated apoptosis, the expression of NF-${\kappa}Bp65$, cyclinD1 and p16 in SGC-7901 cells was analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. Results: TMP inhibited the proliferation of human gastric carcinoma cell line 7901 in dose and time dependent manners. Cell growth was suppressed by TMP at different concentrations (0.25, 0.5, 1.0, 2.0 mg/ml), the inhibition rate is 0.46%, 4.36%, 14.8%, 76.1% (48h) and 15.5%, 18.5%, 41.2%, 89.8% (72h) respectively. When the concentration of TMPs was 2.0mg/ml, G1-phase arrest in the SGC-7901 cells was significant based on the data for cell cycle distribution. RT-PCR demonstrated that NF-${\kappa}Bp65$ and cyclin D1 mRNA expression was significantly down-regulated in 7901 cells treated with 2.0 mg/ml TMP for 72h (p<0.05), while the p16 mRNA level was up-regulated (p<0.05). The protein expression of NF-${\kappa}Bp65$ and cyclin D1 decreased gradually with the increase in TMP concentration, compared with control cells (p<0.05), while expression of protein p16 was up-regulated (p<0.01). Conclusion: TMP exhibits significant anti-proliferative and pro-apoptotic effects on the human gastric carcinoma cell line SGC-7901. NF-${\kappa}Bp65$, cyclinD1 and p16 may also play important roles in the regulation mechanisms.