• Journal of Oral Medicine and Pain
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• v.48 no.4
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• pp.169-173
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• 2023

Hemangioma is a lesion characterized by vascular proliferation of endothelial origin, manifesting neoplastic features. The occurrence of central hemangioma in the oral and maxillofacial region is exceptionally rare, and in two-thirds of cases, it is predominant in the mandible rather than the maxilla. The main symptoms and signs associated with central hemangiomas include pulsation, bone expansion, bruit, teeth displacement, and root resorption of the adjacent teeth. Bleeding may manifest periodically from the sulcus surrounding the affected teeth, particularly when accompanied by hypermobility in the primary dentition. One of the most noteworthy complications is the potential for severe bleeding during tooth extraction or surgical procedures conducted in proximity to unrecognized hemangiomas. Such situations may pose a life-threatening risk. Taking this into consideration, we present two cases of central hemangiomas in adolescent patients who sought consultation, with subsequent embolization performed by the Department of Radiology in Chosun University Hospital.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.4
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• pp.315-320
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• 2013

Here, we show that radicicol, a fungal antibiotic, resulted in marked inhibition of inducible nitric oxide synthase (iNOS) transcription by the pancreatic beta cell line MIN6N8a in response to cytokine mixture (CM: TNF-${\alpha}$, IFN-${\gamma}$, and IL-$1{\beta}$). Treatment of MIN6N8a cells with radicicol inhibited CM-stimulated activation of NF-${\kappa}B$/Rel, which plays a critical role in iNOS transcription, in a dose-related manner. Nitrite production in the presence of PD98059, a specific inhibitor of the extracellular signal-regulated protein kinase-1 and 2 (ERK1/2) pathway, was dramatically diminished, suggesting that the ERK1/2 pathway is involved in CM-induced iNOS expression. In contrast, SB203580, a specific inhibitor of p38, had no effect on nitrite generation. Collectively, this series of experiments indicates that radicicol inhibits iNOS gene expression by blocking ERK1/2 signaling. Due to the critical role that NO release plays in mediating destruction of pancreatic beta cells, the inhibitory effects of radicicol on iNOS expression suggest that radicicol may represent a useful anti-diabetic activity.

• Journal of Integrative Natural Science
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• v.11 no.2
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• pp.69-75
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• 2018

The red algae Gracilaria vermiculophylla is widely spread around seaside areas across the globe, and has been used as a food resource in Southeast Asian countries. Previous studies have shown that Gracilaria red algae extracts have beneficial antihypercholesterolemic, antioxidant, anti-inflammatory, and antimicrobial effects. In this study, we investigated the antioxidant effects of Gracilaria vermiculophylla extracts (GV-Ex) on human bone marrow mesenchymal stem cells (hBM-MSCs). The acetone and DMSO/ethanol solvents of the tested GV contain higher total flavonoid and polyphenolic contents that can strongly scavenge reactive oxygen species (ROS). Pre-treatment with GV-Ex protected hBM-MSCs against oxidative stress induced by hydrogen peroxide treatment. The protective effects of GV-Ex treatment were confirmed by MTT assay. The elevated levels of ROS in hBM-MSCs caused by hydrogen peroxide induced oxidative stress were significantly decreased by GV extract treatment. The levels of the antioxidant proteins superoxide dismutase 1 (SOD1), superoxide dismutase 2 (SOD2), and catalase (CAT) were also restored or protected by GV-Ex treatment, suggesting that GV extracts moderate excess ROS levels and prevent cells from oxidative damage.

• International Journal of Oral Biology
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• v.46 no.1
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• pp.23-29
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• 2021

Demethoxycurcumin (DMC), which is a curcuminoid found in turmeric, has anti-proliferative effects on cancer cells. However, the effect of DMC on osteosarcoma has not been established. The aim of this study was to examine the effects of DMC on cell growth and apoptosis induction in MG-63 human osteosarcoma cells. This study was investigated using 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromid assay, Live/Dead cell assay, 4', 6-diamidino-2-phenylindole staining, and immunoblotting in MG-63 cells. DMC induced MG-63 cell death in a dose-dependent manner, with an estimated IC50 value of 54.4 µM. DMC treatment resulted in nuclear condensation in MG-63 cells. DMC-induced apoptosis in MG-63 cells was mediated by the expression of Fas and activation of caspase-8, caspase-3, and poly (ADP-ribose) polymerase. Immunoblotting results showed that Bcl-2 and Bcl-xL were downregulated, while Bax and Bad were upregulated by DMC in MG-63 cells. These results indicated that DMC inhibits cell proliferation and induces apoptotic cell death in MG-63 human osteosarcoma cells via the death receptor-mediated extrinsic apoptotic pathway and mitochondria-mediated intrinsic apoptotic pathway.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.1
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• pp.37-45
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• 2022

The aim of the present study was to investigate the physiological role of nicotinamide phosphoribosyltransferase (NAMPT) associated with odontogenic differentiation during tooth development in mice. Mouse dental papilla cell-23 (MDPC-23) cells cultured in differentiation media were stimulated with the specific NAMPT inhibitor, FK866, and Visfatin (NAMPT) for up to 10 days. The cells were evaluated after 0, 4, 7, and 10 days. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The mineralization assay was performed by staining MDPC-23 cells with Alizarin Red S solution. After cultivation, MDPC-23 cells were harvested for quantitative PCR or Western blotting. Analysis of variance was performed using StatView 5.0 software (SAS Institute Inc., Cary, NC, USA). Statistical significance was set at p < 0.05. The expression of NAMPT increased during the differentiation of murine odontoblast-like MDPC-23 cells. Furthermore, the up-regulation of NAMPT promoted odontogenic differentiation and accelerated mineralization through an increase in representative odontoblastic biomarkers, such as dentin sialophosphoprotein, dentin matrix protein-1, and alkaline phosphatase in MDPC-23 cells. However, treatment of the cells with the NAMPT inhibitor, FK866, attenuated odontogenic differentiation, as evidenced by the suppression of odontoblastic biomarkers. These data indicate that NAMPT regulated odontoblastic differentiation through the regulation of odontoblastic biomarkers. The increase in NAMPT expression in odontoblasts was closely related to the formation of the extracellular matrix and dentin via the Runx signaling pathway. Therefore, these data suggest that NAMPT is a critical regulator of odontoblast differentiation during tooth development.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.6
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• pp.447-456
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• 2022

The present study was carried out to investigate the effect of Arctigenin on cell growth and the mechanism of cell death elicited by Arctigenin were examined in FaDu human pharyngeal carcinoma cells. To determine the apoptotic activity of Arctigenin in FaDu human pharyngeal carcinoma cells, cell viability assay, DAPI staining, caspase activation analysis, and immunoblotting were performed. Arctigenin inhibited the growth of cells in a dose-dependent manner and induced nuclear condensation and fragmentation. Arctigenin-treated cells showed caspase-3/7 activation and increased apoptosis versus control cells. FasL, a death ligand associated with extrinsic apoptotic signaling pathways, was up-regulated by Arctigenin treatment. Moreover, caspase-8, a part of the extrinsic apoptotic pathway, was activated by Arctigenin treatments. Expressions of anti-apoptotic factors such as Bcl-2 and Bcl-xL, components of the mitochondria-dependent intrinsic apoptosis pathway, significantly decreased following Arctigenin treatment. The expressions of pro-apoptotic factors such as BAX, BAD and caspase-9, and tumor suppressor -53 increased by Arctigenin treatments. In addition, Arctigenin activated caspase-3 and poly (ADP-ribose) polymerase (PARP) induced cell death. Arctigenin also inhibited the proliferation of FaDu cells by the suppression of p38, NF-κB, and Akt signaling pathways. These results suggest that Arctigenin may inhibit cell proliferation and induce apoptotic cell death in FaDu human pharyngeal carcinoma cells through both the mitochondria-mediated intrinsic pathway and the death receptor-mediated extrinsic pathway.

• Molecules and Cells
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• v.46 no.4
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• pp.245-255
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• 2023

This study aimed to exploring the pathophysiological mechanism of 7α,25-dihydroxycholesterol (7α,25-DHC) in osteoarthritis (OA) pathogenesis. 7α,25-DHC accelerated the proteoglycan loss in ex vivo organ-cultured articular cartilage explant. It was mediated by the decreasing extracellular matrix major components, including aggrecan and type II collagen, and the increasing expression and activation of degenerative enzymes, including matrix metalloproteinase (MMP)-3 and -13, in chondrocytes cultured with 7α,25-DHC. Furthermore, 7α,25-DHC promoted caspase-dependent chondrocyte death via extrinsic and intrinsic pathways of apoptosis. Moreover, 7α,25-DHC upregulated the expression of inflammatory factors, including inducible nitric oxide synthase, cyclooxygenase-2, nitric oxide, and prostaglandin E₂, via the production of reactive oxygen species via increase of oxidative stress in chondrocytes. In addition, 7α,25-DHC upregulated the expression of autophagy biomarkers, including beclin-1 and microtubule-associated protein 1A/1B-light chain 3 via the modulation of p53-Akt-mTOR axis in chondrocytes. The expression of CYP7B1, caspase-3, and beclin-1 was elevated in the degenerative articular cartilage of mouse knee joint with OA. Taken together, our findings suggest that 7α,25-DHC is a pathophysiological risk factor of OA pathogenesis that is mediated a chondrocyte death via oxiapoptophagy, which is a mixed mode of apoptosis, oxidative stress, and autophagy.

• Journal of Preventive Medicine and Public Health
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• v.57 no.1
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• pp.47-54
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• 2024

Objectives: This study was conducted to systematically summarize trends in research concerning patients with coronavirus disease 2019 (COVID-19) as reported in Korean medical journals. Methods: We performed a literature search of KoreaMed from January 2020 to September 2022. We included only primary studies of patients with COVID-19. Two reviewers screened titles and abstracts, then performed full-text screening, both independently and in duplicate. We first identified the 5 journals with the greatest numbers of eligible publications, then extracted data pertaining to the general characteristics, study population attributes, and research features of papers published in these journals. Results: Our analysis encompassed 142 primary studies. Of these, approximately 41.0% reported a funding source, while 3.5% disclosed a conflict of interest. In 2020, 42.9% of studies included fewer than 10 participants; however, by 2022, the proportion of studies with over 200 participants had increased to 40.6%. The most common design was the cohort study (48.6%), followed by case reports/series (35.2%). Only 3 randomized controlled trials were identified. Studies most frequently focused on prognosis (58.5%), followed by therapy/intervention (20.4%). Regarding the type of intervention/exposure, therapeutic clinical interventions comprised 26.1%, while studies of morbidity accounted for 13.4%. As for the outcomes measured, 50.7% of studies assessed symptoms/clinical status/improvement, and 14.1% evaluated mortality. Conclusions: Employing a systematic approach, we examined the characteristics of research involving patients with COVID-19 that was published in Korean medical journals from 2020 onward. Subsequent research should assess not only publication trends over a longer timeframe but also the quality of evidence provided.

• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.110-115
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• 2004

This study was undertaken to develop PCR primers for the simultaneous detection of Fusobacterium nucleatum and Actinobacillus actinomycetemcomitans, using two species-specific reverse primers in combination with a single conserved forward primer. These primers target the variable and conserved regions of the 16S rDNA. The primer specificity was tested against (i) four F. nucleatum and three A. actinomycetemcomitans strains and (ii) seven representatives of the different species of oral bacteria. The primer sensitivity was determined by testing serial dilutions of the purified genomic DNA of F. nucleatum and A. actinomycetemcomitans. The data indicate that species-specific amplicons could be obtained for all the F. nucleatum and A. actinomycetemcomitans strains tested, which were not found in the seven other species. The multiplex PCR could detect as little as 4 fg of chromosomal DNA of F. nucleatum and A. actinomycetemcomitans simultaneously. These findings suggest that these PCR primers are highly sensitive and are suitable for applications in epidemiological studies, diagnosis, and monitoring F. nucleatum and A. actinomycetemcomitans after the treatment of periodontitis.

• Journal of Periodontal and Implant Science
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• v.35 no.4
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• pp.949-959
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• 2005

이 연구는 임플란트를 식립하기를 원하는 전신건강상태가 양호하며 구강위생상태가 좋은 14명 환자(남자:8명, 여자:6명, 평균나이 : 44세)의 20개의 발치와 내에 흡수성 차폐막(BioMesh. Sam Yang Corporation, Korea)과 함께 탈회냉동 건조동종 골(dem-ineralized freezedried bone allografts, $250-500{\mu}m$. Pacific Coast Tissue Bank, U.S.A.)과 이종골(Bovine-Bone, Bio-Oss 0.25-1.0 mm, Geistlich, Biomaterials and Osteohealth, Switzerland)을 1:1(부피)로 혼합하여 이식한 후 그 치유양상을 관찰하고자 조직학적 및 면역조직화학적으로 평가하였다. 이직재가 탈락되는 것을 방지하기 위하여 발치한 후 1개윌이 경과된 후에 이식재와 차폐막을 위치시켰다. 표본제작을 위하여 이식술을 시행한 지 약 6개윌 후에 임플란트를 식립하기 직전 식립부위에서 trephine bur로 골을 채취하였는데, 20증례 중 7증례에서 임플란트를 식립하기 전에 차폐막이 노출되었다. 차폐막이 노출되지 않은 것을 대조군으로, 노출된 것을 실험군으로 설정하였다. 조직학적인 관찰을 위하여 통상적인 방법에 따라 탈회 표본을 제작하였고, alkaline phosphotase(ALP)틀 이용하여 면역조직화학적 염색을 시행한 후 골 형성 상태를 평가하여 다음과 같은 결과를 얻었다. 본 연구에서는 발치와내에서 골유도재생술 후 나타나는 치유 형태를 5가지 형태로 분류할 수 있었다. Type I, II와 III는 새로운 골 형성을 나타내지 않았고, 면역조직화학적 검사 시 ALP 음성 소견을 나타내었다. Type V는 새로운 골 형성과 ALP 양성 소견을 나타내었으나 염증, 괴사, 결합조직의 증식 등은 없었다. Type IV와 Type V의 차이는 결합조직의 증식여부로 구분되었다. 막이 노출되지않은 증례들 중 7 증례에서는 Type V의 치유 형태를, 2증례에서는 Type IV의 치유 형태를 나타내었다. 막이 노출되었던 증례에서는 Type I, II, III의 다양한 치유 형태를 나타내었다. 본 연구결과, 발치와 내에 골유도재생술을 시행한 후 차폐막의 노출 여부가 신생골 형성에 중요한 영향을 미칠 것으로 사료되며, 본 연구에서 분류한 치유 형태가 향후 골유도재생술 후의 결과 분석에 활용될 수 있을 것으로 사료된다.