• The Journal of the Korea Contents Association
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• v.5 no.5
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• pp.281-286
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• 2005

This research is to measure the irradiation dose in radiological technologists with 623 radiological technologists working at 44 general hospitals in 16 cities and states nation-wide, during one month from July to August 2003. Questionnaires were used to analyze the dose, while existing data from measurements taken in 5 years was used to analyze amounts of radiation dose level. Average annual irradiation dose level was $1.73{\pm}0.10mSv$ in 5 years from 1998 to 2002. Annually, 2000 had the highest level With $1.80{\pm}0.15mSv$, While 1998 was lowest with $1.36{\pm}0.12mSv$, but a long-term solution needs to be worked out since there is a possibility of chronic exposure due to the nature of the work. The results of present research shows that the radiological technologists are effecting managing irradiation dose.

• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1349-1360
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• 2019

Chronic exposure to ultraviolet (UV) radiation, regarded as a major cause of extrinsic aging or photoaging characterized by wrinkle formation and skin dehydration, exerts adverse effects on skin by causing the overproduction of reactive oxygen species. Agastache rugosa Kuntze, known as Korean mint, possesses a wide spectrum of biological properties including anti-oxidation, anti-inflammation, and anti-atherosclerosis. Previous studies have reported that A. rugosa protected human keratinocytes against UVB irradiation by restoring the anti-oxidant defense system. However, the anti-photoaging effect of A. rugosa extract (ARE) in animal models has not yet been evaluated. ARE was orally administered to hairless mice at doses of 100 or 250 mg/kg/day along with UVB exposure for 12 weeks. ARE histologically improved UVB-induced wrinkle formation, epidermal thickening, erythema, and hyperpigmentation. In addition, ARE recovered skin moisture by improving skin hydration and transepidermal water loss (TEWL). Along with this, ARE increased hyaluronic acid levels by upregulating HA synthase genes. ARE markedly increased the density of collagen and the amounts of hydroxypoline via two pathways. First, ARE significantly downregulated the mRNA expression of matrix metalloproteinases responsible for collagen degradation by inactivating the mitogen-activated protein kinase/activator protein 1 pathway. Second, ARE stimulated the transforming growth factor beta/Smad signaling, consequently raising the mRNA levels of collagen-related genes. In addition, ARE not only increased the mRNA expression of anti-oxidant enzymes but also decreased inflammatory cytokines by blocking the protein expression of nuclear factor kappa B. Collectively, our findings suggest that A. rugosa may be a potential preventive and therapeutic agent for photoaging.

• Journal of Radiation Protection and Research
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• v.43 no.2
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• pp.39-49
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• 2018

Background: A model to assess the activity concentration of agricultural products and the public ingestion dose as result of a nuclear accident is necessarily required to manage the contaminated agricultural systems by the accident, or to estimate the effects of chronic exposure due to food ingestion at a Level 3 PSA. Materials and Methods: A dynamic compartment model, which is composed of three sub-modules, namely, an agricultural plant contamination assessment model, an animal product contamination assessment model, and an ingestion dose assessment model has been developed based on Korean farming characteristics such as the growth characteristics of rice and stockbreeding. Results and Discussion: The application study showed that the present model can predict well the characteristics of the activity concentration for agricultural products and ingestion dose depending on the deposition date. Conclusion: The present model is very useful to predict the radioactivity concentration of agricultural foodstuffs and public ingestion dose as consequence of a nuclear accident. Consequently, it is expected to be used effectively as a module for the ingestion dose calculation of the Korean agricultural contamination management system as well as the Level 3 PSA code, which is currently being developed.

• Journal of Radiation Protection and Research
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• v.28 no.1
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• pp.43-50
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• 2003

This study describes a practical method for interpretation of bioassay results of inhaled uranium to assess the committed effective doses both for chronic and acute intake situations. Organs in the body were represented by a series of mathematical compartments for analysis of the behavior of uranium in the body according to the gastrointestinal track model, respiratory track model and biokinetic model recommended by the ICRP. An analytical solutions of the system of balance equations among the compartments were obtained using the Birchall's algorithm, and the urinary excretion function and the lung retention function of uranium were obtained. An initial or total intakes by intake modes were calculated by applying excretion and retention functions to the urinary uranium concentration and the lung burden measured with a lung counter. The dose coefficients given in ICRP 78 are used to estimate the committed effective doses from the calculated intakes.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.1
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• pp.87-94
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• 2021

Skin photoaging occurs due to chronic exposure to solar ultraviolet radiation (UV), the main factor contributing to extrinsic skin aging. Clinical signs of photoaging include the formation of deep, coarse skin wrinkles and hyperpigmentation. Although melanogenesis and skin wrinkling occur in different skin cells and have different underlying mechanisms, their initiation involves intracellular calcium signaling via calcium ion channels. The ORAI1 channel initiates melanogenesis in melanocytes, and the TRPV1 channel initiates MMP-1 production in keratinocytes in response to UV stimulation. We aimed to develop a drug that may simultaneously inhibit ORAI1 and TRPV1 activity to help prevent photoaging. We synthesized nootkatol, a chemical derivative of valencene. TRPV1 and ORAI1 activities were measured using the whole-cell patch-clamp technique. Intracellular calcium concentration [Ca2+]i was measured using calcium-sensitive fluorescent dye (Fura-2 AM). UV-induced melanin formation and MMP-1 production were quantified in B16F10 melanoma cells and HaCaT cells, respectively. Our results indicate that nootkatol (90 μM) reduced TRPV1 current by 94% ± 2% at -60 mV and ORAI1 current by 97% ± 1% at -120 mV. Intracellular calcium signaling was significantly inhibited by nootkatol in response to ORAI1 activation in human primary melanocytes (51.6% ± 0.98% at 100 μM). Additionally, UV-induced melanin synthesis was reduced by 76.38% ± 5.90% in B16F10 melanoma cells, and UV-induced MMP-1 production was reduced by 59.33% ± 1.49% in HaCaT cells. In conclusion, nootkatol inhibits both TRPV1 and ORAI1 to prevent photoaging, and targeting ion channels may be a promising strategy for preventing photoaging.

• Journal of Preventive Medicine and Public Health
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• v.43 no.2
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• pp.159-165
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• 2010

Objectives: We evaluated the reliability of the possible covariates of the baseline survey data collected for the Epidemiological Investigation on Cancer Risk Among Residents Who Reside Near the Nuclear Power Plants in Korea. Methods: Follow-up surveys were conducted for 477 participants of the cohort at less than 1 year after the initial survey. The mean interval between the initial and follow-up surveys was 282.5 days. Possible covariates were identified by analyzing the correlations with the exposure variable and associations with the outcome variables for all the variables. Logistic regression analysis with stepwise selection was further conducted among the possible covariates to select variables that have covariance with other variables. We considered that these variables can be representing other variables. Seven variables for the males and 3 variables for the females, which had covariance with other possible covariates, were selected as representative variables. The Kappa index of each variable was calculated. Results: For the males, the Kappa indexes were as follow; family history of cancer was 0.64, family history of liver diseases in parents and siblings was 0.56, family history of hypertension in parents and siblings was 0.51, family history of liver diseases was 0.50, family history of hypertension was 0.44, a history of chronic liver diseases was 0.53 and history of pulmonary tuberculosis was 0.36. For females, the Kappa indexes were as follow; family history of cancer was 0.58, family history of hypertension in parents and siblings was 0.56 and family history of hypertension was 0.47. Conclusions: Most of the possible covariates showed good to moderate agreement.

• Archives of Reconstructive Microsurgery
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• v.7 no.2
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• pp.114-121
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• 1998

The purpose of this study is to investigate the appropriate management of severe radionecrotic wounds of the anterior chest wall associated with infection of the soft tissues and ribs and exposure of vital structures(heart and lung), and present our strategies for reconstruction of these complicated patients. 9 patients have undergone radical debridement and immediate microsurgical reconstruction for severe radionecrotic wounds of the anterior chest wall over last 7 years. All patients had extensive osteomyelitis of the ribs or sternum, and chronic infection or cutaneous fistulae. 2 patients had pericardial effusions due to longstanding inflammation, and 6 patients had pleural effusions. 2 patients had ipsilateral lung collapse. 10 free flaps were performed for coverage of the huge defects. One patient required 2 free flaps to control the inflammation. 8 free TRAM flaps were used for coverage of the defects and in addition, the rectus abdominis muscle was packed into any deep cavity. 1 patients underwent latissimus dorsi muscle free flap because of previous abdominal surgery. After extensive debridement of the infected, radionecrotic wounds, all 10 free flaps were successful. All the extensive radionecrotic defects of the anterior chest wall were completely healed. Free flaps successfully covered the exposed vital structures of the heart and lungs. Patients with severe radionecrotic defects of the anterior chest wall after ablative breast cancer surgery and radiotherapy were successfully treated by radical debridement and immediate free flap surgery. The TRAM flap together with the rectus muscle is the treatment of choice for these huge defects. The latissimus dorsi muscle flap was the second choice in patients with previous abdominal surgery. The recipient vessel should be carefully selected because of possible radiation damage and inflammation.

• Biomolecules & Therapeutics
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• v.21 no.6
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• pp.470-475
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• 2013

Ultraviolet (UV) radiation is a major environmental factor that leads to acute and chronic reactions in the human skin. UV exposure induces wrinkle formation, DNA damage, and generation of reactive oxygen species (ROS). Most mechanistic studies of skin physiology and pharmacology related with UV-irradiated skin have focused on proteins and their related gene expression or single-targeted small molecules. The present study identified and analyzed the alteration of skin metabolites following UVB irradiation and topical retinyl palmitate (RP, 5%) treatment in hairless mice using direct analysis in real time (DART) time-of-flight mass spectrometry (TOF-MS) with multivariate analysis. Under the negative ion mode, the DART ion source successfully ionized various fatty acids including palmitoleic and linolenic acid. From DART-TOF-MS fingerprints measured in positive mode, the prominent dehydrated ion peak (m/z: 369, M+H-$H_2O$) of cholesterol was characterized in all three groups. In positive mode, the discrimination among three groups was much clearer than that in negative mode by using multivariate analysis of orthogonal partial-least squares-discriminant analysis (OPLS-DA). DART-TOF-MS can ionize various small organic molecules in living tissues and is an efficient alternative analytical tool for acquiring full chemical fingerprints from living tissues without requiring sample preparation. DART-MS measurement of skin tissue with multivariate analysis proved to be a powerful method to discriminate between experimental groups and to find biomarkers for various experiment models in skin dermatological research.

• Biomolecules & Therapeutics
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• v.12 no.3
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• pp.157-164
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• 2004

DA-3711 is a novel anti-wrinkle agent containing growth factors derived from culture medium of artificial human skin. Photoprotective effect by DA-3711 against chronic UVB (ultraviolet B)-induced skin damage was investigated in hairless mice model. Methods: After hairless mice were irradiated to induce photodamage for 8 weeks with UVB, grouped mice were treated topically once a day with lotion base, DA-3711 (30% or l5%), Cylasphere retinol$^{\circed{R}}$ (2500 I.U.), NouriCel$^{\circed{R}}$ along with concomitant exposure to UVB for further 8 weeks. Then mice were sacrificed to assess photodamage-protective effect by replica analysis, biochemistry and histology. DA-3711 of 30% lotion significantly reduced UVB radiation-induced wrinkling, histological alterations and increased collagen contents. Whereas DA-3711 of l5% lotion and NouriCel$^{\circed{R}}$ treatment showed a partial protective effect on skin wrinkle, epidermal and dermal thickness, and collagen content, Cylasphere retinol$^{\circed{R}}$ showed no protective effects. These results demonstrate that topical application of DA-3711 can alleviate UVB-induced photodamage and potentially be used for reduction of UVB-induced photodamage.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.50 no.1
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• pp.41-48
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• 2024

Objectives: Botulinum toxin type A (BTX), a powerful neurotoxin, can be an effective treatment choice for diverse muscular disorders and can reduce abnormal muscle activities. Abnormal movements of the mandible can be caused by involuntary and uncontrolled contractions of the lateral pterygoid muscle (LP) in various pathological situations. Previous reports have shown that BTX can reduce abnormal contractions of the LP. However, needle placement into the LP for BTX injection requires skill, experience, and sufficient anatomical knowledge. To place the needle precisely into the LP, ultrasonography (USG) can be used as an effective needle-guidance modality. USG is a non-invasive imaging modality able to create real-time images without any potential risks, including radiation exposure. Patients and Methods: The patients who had been performed USG-guided BTX injection into the LP using an intraoral approach were included in this study with a literature review and case presentations. Using the USG, four patients received BTX injections to treat recurrent temporomandibular dislocation and oromandibular dystonia resulting from involuntary LP activity. Result: Involuntary movements of the mandible were improved successfully in all patients, and showed satisfactory results without significant complication. Conclusion: The intraoral approach could prevent potential complications during needle placement. USG-guided BTX injection is an effective, convenient, and safe method that provides real-time imaging without unnecessary pain to the patient.