• Title/Summary/Keyword: school of dentistry

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An Assessment on Cu-Equivalent Image of Digital Intraoral Radiography (디지털구내방사선사진의 구리당량화상에 대한 평가)

  • KIM JAE-DUK
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.29 no.1
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    • pp.33-42
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    • 1999
  • Geometrically standardized dental radiographs were taken. We prepared Digital Cu-Equivalent Image Analyzing System for quantitative assessment of mandible bone. Images of radiographs were digitized by means of Quick scanner and personal Mcquintosh computer. NIH image as software was used for analyzing images. A stepwedge composed of 10 steps of 0.1mm copper foil in thickness was used for reference material. This study evaluated the effects of step numbers of copper wedge adopted for calculating equation. kVp and exposure time on the coefficient of determination(r²)of the equation for conversion to Cu-equivalent image and the coefficient of variation and Cu-Eq value(mm) measured at each copper step and alveolar bone of the mandible. The results were as follows: 1. The coefficients of determination(r²) of 10 conversion equations ranged from 0.9996 to 0.9973(mean=0.9988) under 70kVp and 0.16 sec. exposure. The equation showed the highest r was Y=4.75614612-0.06300524x +0.00032367x² -0.00000060x³. 2. The value of r² became lower when the equation was calculated from the copper stepwedge including 1.0mm step. In case of including 0mm step for calculation. the value of r showed variability. 3. The coefficient of variation showed 0.11, 0.20 respectively at each copper step of 0.2, 0.1mm in thickness. Those of the other steps to 0.9 mm ranged from 0.06 to 0.09 in mean value. 4. The mean Cu-Eq value of alveolar bone was 0.14±0.02mm under optimal exposure. The values were lower than the mean under the exposures over 0.20sec. in 60kVp and over 0.16sec. in 70kVp. 5. Under the exposure condition of 60kVp 0.16sec.. the coefficient of variation showed 0.03. 0.05 respectively at each copper-step of 0.3, 0.2mm in thickness. The value of r² showed over 0.9991 from both 9 and 10 steps of copper. The Cu-Eq value and the coefficient of variation was 0.14±0.01mm and 0.07 at alveolar bone respectively. In summary. A clinical application of this system seemed to be useful for assessment of quantitative assessment of alveolar provided high coefficient of determination is obtained by the modified adoption of copper step numbers and the low coefficient of variation for the range of Cu-Equivalent value of alveolar bone from optimal kVp and exposure time for each x-ray machine.

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GRIM-19 Ameliorates Multiple Sclerosis in a Mouse Model of Experimental Autoimmune Encephalomyelitis with Reciprocal Regulation of IFNγ/Th1 and IL-17A/Th17 Cells

  • Jeonghyeon Moon;Seung Hoon Lee;Seon-yeong Lee;Jaeyoon Ryu;Jooyeon Jhun;JeongWon Choi;Gyoung Nyun Kim;Sangho Roh;Sung-Hwan Park;Mi-La Cho
    • IMMUNE NETWORK
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    • v.20 no.5
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    • pp.40.1-40.15
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    • 2020
  • The protein encoded by the Gene Associated with Retinoid-Interferon-Induced Mortality-19 (GRIM-19) is located in the mitochondrial inner membrane and is homologous to the NADH dehydrogenase 1-alpha subcomplex subunit 13 of the electron transport chain. Multiple sclerosis (MS) is a demyelinating disease that damages the brain and spinal cord. Although both the cause and mechanism of MS progression remain unclear, it is accepted that an immune disorder is involved. We explored whether GRIM-19 ameliorated MS by increasing the levels of inflammatory cytokines and immune cells; we used a mouse model of experimental autoimmune encephalomyelitis (EAE) to this end. Six-to-eight-week-old male C57BL/6, IFNγ-knockout (KO), and GRIM-19 transgenic mice were used; EAE was induced in all strains. A GRIM-19 overexpression vector (GRIM19 OVN) was electrophoretically injected intravenously. The levels of Th1 and Th17 cells were measured via flow cytometry, immunofluorescence, and immunohistochemical analysis. IL-17A and IFNγ expression levels were assessed via ELISA and quantitative PCR. IL-17A expression decreased and IFNγ expression increased in EAE mice that received injections of the GRIM-19 OVN. GRIM19 transgenic mice expressed more IFNγ than did wild-type mice; this inhibited EAE development. However, the effect of GRIM-19 overexpression on the EAE of IFNγ-KO mice did not differ from that of the empty vector. GRIM-19 expression was therapeutic for EAE mice, elevating the IFNγ level. GRIM-19 regulated the Th17/Treg cell balance.

EXPRESSION OF TGF-α AND TGF-β (구강암 발생 과정에서 TGF-α 및 TGF-β 발현에 관한 연구)

  • Yang, Hee-Chang;Lee, Dong-Keun;Kim, Eun-Cheol
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.19 no.4
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    • pp.414-434
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    • 1997
  • Though many genetic and epigenetic alterations have been identified in hamster oral carcinogenesis model, there is no information about the possible role of transforming growth factor related with oral cancer. The purpose of this paper was to find the expression patterns of transforming growth factor alpha and beta during the stages of complete oral carcinogenesis model in hamster. 0.5% 9, 10-dimethyl-1, 2-benzanthracene(DMBA) in mineral oil was topically applied to the buccal pouch of 75 hamster three times a week during the experimental periods. The experimental animals were subdivided into two groups of control and experiment. Only the mineral oil was applied to the control group. 0.5% DMBA in mineral oil was applied to the experimental groups of 6, 8, 10, 12, 14, 16, 18 and 20 weeks. The expression of the $TGF-{\alpha}$ and $TGF-{\beta}$ protein were evaluated by the distribution and intensity of positive cells during the carcinogenesis using the immunohistochemical study. The following results were obtained ; 1. The buccal pouch epithelium of hamster was histologically changed to the dysplasia at 6, 8, 10 weeks, carcinoma in situ at 12 weeks, and squamous cell carcinoma at 14 weeks. 2. The expression of the $TGF-{\alpha}$ was restricted to the parabasal and basal layers of the normal and dysplastic mucosa, but those positive cells were extended to the spinous layers of the epithelium in the carcinoma. 3. The degree of $TGF-{\alpha}$ expression was markedly decreased in the carcinoma at 16, 18, 20. The strong positive staining in the center of cancer islands and weak positive staining in periphery of tumor were seen at the stage of squamous cell carcinoma. 4. The positive index of the $TGF-{\alpha}$ had a tendency to increase with DMBA- applied time. There was a statistically significant difference between 12, 18, 20 experimental group and control group (p<0.05). 5. The expression of the $TGF-{\beta}$ was shown at the cytoplasm of all control and experimental groups, and the parabasal and basal layers of the normal and dyslastic mucosa, but it was shown at the basal layers of the epithelium in the carcinoma. 6. $TGF-{\beta}$ was expressed diffusely at 16, 18, 20 experimental group. The strong positive staining in the center of cancer islands and positive staining in periphery of tumor were seen at the stage of squamous cell carcinoma. From the above findings, the expression of $TGF-{\alpha}$ and ${\beta}$ in oral carcinogenesis model seems to have two formal stages, the first being an overexpression step as reaction to uncontrolled growth and the second being one in which external protein accumulate in the surrounding stroma and intracytoplasm. Overexpression of $TGF-{\alpha}$ and ${\beta}$ may have important cooperative roles for the promotion of cancer and factor of prognosis.

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Regulator of G-Protein Signaling 4 (RGS4) Controls Morphine Reward by Glutamate Receptor Activation in the Nucleus Accumbens of Mouse Brain

  • Kim, Juhwan;Lee, Sueun;Kang, Sohi;Jeon, Tae-Il;Kang, Man-Jong;Lee, Tae-Hoon;Kim, Yong Sik;Kim, Key-Sun;Im, Heh-In;Moon, Changjong
    • Molecules and Cells
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    • v.41 no.5
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    • pp.454-464
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    • 2018
  • Crosstalk between G-protein signaling and glutamatergic transmission within the brain reward circuits is critical for long-term emotional effects (depression and anxiety), cravings, and negative withdrawal symptoms associated with opioid addiction. A previous study showed that Regulator of G-protein signaling 4 (RGS4) may be implicated in opiate action in the nucleus accumbens (NAc). However, the mechanism of the NAc-specific RGS4 actions that induce the behavioral responses to opiates remains largely unknown. The present study used a short hairpin RNA (shRNA)-mediated knock-down of RGS4 in the NAc of the mouse brain to investigate the relationship between the activation of ionotropic glutamate receptors and RGS4 in the NAc during morphine reward. Additionally, the shRNA-mediated RGS4 knock-down was implemented in NAc/striatal primary-cultured neurons to investigate the role that striatal neurons have in the morphine-induced activation of ionotropic glutamate receptors. The results of this study show that the NAc-specific knock-down of RGS4 significantly increased the behaviors associated with morphine and did so by phosphorylation of the GluR1 (Ser831) and NR2A (Tyr1325) glutamate receptors in the NAc. Furthermore, the knock-down of RGS4 enhanced the phosphorylation of the GluR1 and NR2A glutamate receptors in the primary NAc/striatal neurons during spontaneous morphine withdrawal. These findings show a novel molecular mechanism of RGS4 in glutamatergic transmission that underlies the negative symptoms associated with morphine administration.

A Study on the Dental Technicians' Professional Self-Concept - Centering on the Dental Technicians in Seoul Area - (치과기공사의 전문직 자아개념 연구 - 서울지역 근무자에 한하여 -)

  • Lee, Hye-Eun
    • Journal of Technologic Dentistry
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    • v.29 no.2
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    • pp.35-47
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    • 2007
  • The aim of this study was to make dental technicians recognize the importance of their professional self-concept, and to provide basic data to devise the educational programs and policies of establishing their positive professional self-concept. In addition, the investigator tried to present some improvement measures for dental technicians' actual services by examining their job satisfaction. Study findings are as follows: First, the score of study subjects' self-concept is 3.41($\pm$.58) (perfect score=5), middle or high in rank. As for the mean score of professional self-concept by realms, the self-concept of communication is 3.59($\pm$.67), the highest; the self-concept of leadership in the realm of professional service is 3.54($\pm$.75); the self-concept of skills is 3.50($\pm$.75); the self-concept of adaptability is 3.47($\pm$.69); and the recognizant level of satisfactory self-concept is 2.95($\pm$.81), below the normal. Second, as for the difference of professional self-concept according to general characteristics, such variables as age, marital states, and the length of one's service have a significant influence upon the recognition of self-concept. First, the self-concept of those whose age is between 31 and 35 is the highest (3.64$\pm$.49), and it is followed by that of those whose age is 36 and above (3.57$\pm$.77) and then that of those whose age is between 26 and 30 (3.31$\pm$.56)). And that of those whose age is below 25 is the lowest. The obove results show us that the professional self-concept of older study subjects is higher than that of younger ones in general(p<.01). As for marital states, that of married persons(3.54$\pm$.64) is higher than that of unmarried ones(3.35$\pm$.55)(p<.05). As for the length of one's service, that of longtime employees is higher than that of short-period workers(p<.01). In relation to positions, a manager's professional self-concept is the highest(3.89$\pm$.55) and that of an assistant technician is the lowest(3.17$\pm$.58). Study findings show that the professional self-concept of higher ranking technicians is higher than that of lower ones in general (p<.001). Based on the study findings, the investigator suggests followings: First, studies on the professional self-concept that is appropriate to the characteristics of dental technicians must be carried out with a new point of view. Second, a tool must be researched and developed in order for the professional self-concept of dental technicians to be measured. Third, if a new professional self-concept is established and a measuring tool is developed, a study on the relationship between dental technicians' professional self-concept and practice performance can be carried out again.

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Effect of aging on Leydig cells of Sprague Dawley rats (흰쥐에서 고환 간질세포에 미치는 노화의 영향)

  • Kim, In-Shik;Tae, Hun-Jin;Li, Li-Guang;Park, Young-Jae;Kang, Hyung-Sub;Park, Sang-Youel;Park, Soo-Hyun;Park, Young-Seok;Lee, Young-Hoon;Ahn, Dong-Choon;Choi, Eun-Young;Yang, Hong-Hyun
    • Korean Journal of Veterinary Research
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    • v.43 no.4
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    • pp.541-549
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    • 2003
  • The present study investigated the effects of aging on Leydig cells of Sprague Dawley rats. Rats of 3, 6, 12 and 18 months of age were used. Testes of rat were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in epon-araldite. Using $1{\mu}m$ sections stained with methylene blue, qualitative and quantitative morphological studies were performed. Testis incubations were used to determine luteinizing hormone (LH; 100 ng/ml) stimulated testosterone secretory capacity per testis in vitro. Testosterone levels in the incubation medium, and testosterone and luteinizing hormone levels in serum of these four groups of rats were determined by radioimmunoassay. Morphological studies revealed that Leydig cells were more abundant in the testis interstitium at 6, 12 and 18 months when compared with 3 months. The volumes of Leydig cells per testis was significantly higher, at 6, 12 and 18 months of age than those at 3 months. The number of Leydig cells per testis was doubled at 6, 12 and 18 months of age compared with 3 months. The average volume of a Leydig cell was not significantly different between 3 and 6 months of age, however, at 12 and 18 months a significantly lower value was observed. LH-stimulated testosterone production per testis in vitro was reduced by 45% at 6 months of age compared with 3 months; a further significant reduction was observed at 12 and 18 months. Serum testosterone and LH levels were not significantly different between 3 and 6 months of age but at 12 and 18 months a significantly lower value was observed in both groups for these hormones. These results showed that signs of aging are apparent in Leydig cells of Sprague Dawley rats at 12 months of age.

Comparison of Stress of the Abutment Teeth and Denture Base in Distal Extension Removable Partial Dentures Retained Konus Crown, Precision Attachment and RPI Clasp with the Occlusal Load Application (유리단 국소의치의 교합하중 적용시 이중금관, 어태치먼트 및 RPI clasp 유지장치에 따라 지대치와 의치상에 미치는 응력 비교)

  • Jun, In-Sik;Kim, Bu-Sub;Chung, In-Sung
    • Journal of Technologic Dentistry
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    • v.28 no.2
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    • pp.331-346
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    • 2006
  • Free-end partial dentures, which are supported by teeth surrounded by dental root membranes and elastic mucous membrane tissues, may cause stress to the abutment teeth due to external force imposed on the denture base, increase the mobility of the abutment teeth, and bring about a change in the periodontal tissue. General retainers used in partial dentures are categorized into clasp, attachment, and Konus crown. Stress imposed on the abutment teeth and mobility of the denture base have relations with the lifetime of a crown and abutment teeth, and have direct relations with the chewing ability. Thus, a need arises to make a comparative analysis of stress of the three direct retainers on the abutment teeth and interpret the mobility of the denture base. This study designed three kinds of removable partial dentures (one kind of attachment partial denture, one kind of Konus crown partial denture, and one kind of clasp partial denture), and fabricated Dentiforms of bilateral partial dentures (Kennedy Class I) with lower left 1st premolar and lower right 1st and 2nd premolars being as the abutment teeth. A strain gauge was installed in the mesial and distal surface of the lowerr left 1st premolar (No. 34) of the fabricated dentiform and in the lower part of the denture base, and installed were a clasp partial denture, an attachment partial denture, and a Konus crown partial denture. Then, the vertical static load of 5kgf and 7.5kgf at the occlusion surface of the lower left No. 6 molar was generated for a total of 20 frequencies of load each using a push-full gauge, and thus a change in the output of the strain gauge was measured. With the respective application of Konus crown, attachment and RPI clasp in the free-end partial denture, surveyed was the distribution of stress imposed on the abutment teeth and the denture base according to the location of occlusion force load so as to come up with the following results. 1. Konus crown and attachment partial dentures generated much stress, and more stress on the abutment teeth than RPI clasp dentures did. Attachment dentures tended to further intensify stress on the abutment teeth than Konus crown dentures did. 2. Attachment dentures and Konus dentures imposed less stress on the denture base than RPI clasp dentures did. There was no stress difference between Attachment and Konus crown dentures. 3. Dentures that were designed with the application of retainers using sturdy linkage methods tended to be less mobile.

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A Study of the status of Dental technicians' leisure activities (치과기공사의 여가활동 실태에 관한 연구)

  • Kwon, Soon-Suk;Kim, Yoon-Shin
    • Journal of Technologic Dentistry
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    • v.30 no.1
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    • pp.83-96
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    • 2008
  • This study aims to analyze the major factors in their working conditions affecting the enlargement of leisure activities of dental technicians. We also present a need for dental technicians to assign more time many different kinds of leisure activities for their quality life. To this end, we examined the status and the characteristics of dental technicians' leisure activities among the randomly selected subjects who are working in the area of Seoul, Gyonggido, and Gangwon-do through the analysis of the 311 sheets of self-administered questionnaires. The conclusions from this analysis are as follows; 1. On weekdays, non participants in leisure activities were found to be 64.0%, and in the case of weekends, the participants were reached to 70.7%. Those who enjoy any leisure activities in either of weekdays and weekends were 34.1%, 27.3% of the dental technicians did not have any leisure activities. Therefore, statistical significance was shown in the participations of leisure activities between weekdays and weekends. 2. Of the types of leisure activities in both weekdays and weekends, sports activities were ranked at the top 33.4%, 29.6% respectively, which is followed by going to the cinema/theatre/exhibitions, etc 21.9%, 26.0%, games/entertainment 14.5%, 14.8%, hobbies/cultural activities 14.1%, 12.5%, sightseeing/picnic 6.4%, 7.4%. 3. Of the differences in the characteristics of leisure activities, the types of leisure activities between weekdays and weekends showed difference in gender, company and information regarding leisure activities in age, company and the place of leisure activities, and leisure information in the marital status, career and monthly income in company, company and leisure information in the job position, which is statistically significant (p<.001). However, no statistical significance was found among the other general items of the characteristics of leisure activities. Considering only works on weekdays policy is currently permeating into almost every business sector, dental business owners or managers are advised to consider more effective time management or human resources management, such as keeping reasonable manufacturing time through cooperations with the dentists, regularity of working hours, incentive system, introduction of credible over time payment. Which will provide their staff with more times and opportunities to enjoy their leisure activities. Additionally, the concrete and feasible ways of motivating and activating the leisure activities of dental technicians are in need of further researches and studies.

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The Effect of Lidocaine.HCl on the Fluidity of Native and Model Membrane Lipid Bilayers

  • Park, Jun-Seop;Jung, Tae-Sang;Noh, Yang-Ho;Kim, Woo-Sung;Park, Won-Ick;Kim, Young-Soo;Chung, In-Kyo;Sohn, Uy Dong;Bae, Soo-Kyung;Bae, Moon-Kyoung;Jang, Hye-Ock;Yun, Il
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.6
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    • pp.413-422
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    • 2012
  • The purpose of this study is to investigated the mechanism of pharmacological action of local anesthetic and provide the basic information about the development of new effective local anesthetics. Fluorescent probe techniques were used to evaluate the effect of lidocaine HCl on the physical properties (transbilayer asymmetric lateral and rotational mobility, annular lipid fluidity and protein distribution) of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex, and liposomes of total lipids (SPMVTL) and phospholipids (SPMVPL) extracted from the SPMV. An experimental procedure was used based on selective quenching of 1,3-di(1-pyrenyl)propane (Py-3-Py) and 1,6-diphenyl-1,3,5-hexatriene (DPH) by trinitrophenyl groups, and radiationless energy transfer from the tryptophans of membrane proteins to Py-3-Py. Lidocaine HCl increased the bulk lateral and rotational mobility of neuronal and model membrane lipid bilayes, and had a greater fluidizing effect on the inner monolayer than the outer monolayer. Lidocaine HCl increased annular lipid fluidity in SPMV lipid bilayers. It also caused membrane proteins to cluster. The most important finding of this study is that there is far greater increase in annular lipid fluidity than that in lateral and rotational mobilities by lidocaine HCl. Lidocaine HCl alters the stereo or dynamics of the proteins in the lipid bilayers by combining with lipids, especially with the annular lipids. In conclusion, the present data suggest that lidocaine, in addition to its direct interaction with proteins, concurrently interacts with membrane lipids, fluidizing the membrane, and thus inducing conformational changes of proteins known to be intimately associated with membrane lipid.

Natural Substance MS-10 Improves Women's Health via Regulation of Estrogen Receptor (천연소재 MS-10의 에스트로겐 수용체 조절을 통한 여성건강 증진)

  • Noh, Yoo-Hun;Lee, Ji Won;Park, Jiae;Lee, Sang Hyung;Lee, Jun Young;Kim, Sung-Su;Park, Kwang-Kyun;Kim, Tae Jin;Myung, Soon-Chul;Jeong, Yoonhwa
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.6
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    • pp.903-910
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    • 2016
  • In this study, the expression level of estrogen receptor in an ovariectomized rat model was effectively enhanced by MS-10, Cirsium japonicum and Thymus vulgaris extract complex, in a reversible manner. MS-10 plays a positive role in enhancing estrogen activity at low concentrations, leading to improved women's health. In order to determine whether or not MS-10 improves menopausal symptoms clinically, a randomized, double-blinded, and placebo-controlled clinical study was carried out on 62 middle-aged women treated with 500 mg of MS-10 or placebo daily for 12 weeks. Clinical menopausal symptoms were evaluated by Kupperman's index (KI) detecting various menopausal symptoms, including hot flushes, parenthesis, insomnia, nervousness, melancholia, dizziness, fatigue, rheumatic pain, palpitations, formication, and headaches. Total KI score decreased significantly by about 18% upon ingestion of MS-10. Colpoxerosis, a main symptom of menopause, was significantly reduced by about 21% upon ingestion of MS-10 in contrast to placebo. In addition, reduction of insulin-like growth factor-1 with age was improved by over 10% upon ingestion of MS-10, whereas there were no significant difference with placebo. No side effects appeared after treatment with MS-10. Thus, MS-10 can be suggested as a plausible natural substance for improving women's health.