• Title/Summary/Keyword: factor matrix

Search Result 1,344, Processing Time 0.032 seconds

Anti-photoaging Effects of Flavonoid glycosides from shizophragma hydrangeoides (바위수국으로부터 분리한 플라보노이드 배당체의 광노화 예방 효과)

  • Sung Chun Kim;So Yeon Oh;Hyejin Hyeon;Yong-Hwan Jung;Young-Min Ham
    • Proceedings of the Plant Resources Society of Korea Conference
    • /
    • 2022.09a
    • /
    • pp.25-25
    • /
    • 2022
  • 피부 노화는 피부와 피부 지지층 등의 광범위한 퇴행 과정을 말한다. 피부 노화의 원인은 흡연, 공해, 스트레스 등이 있지만, 그 중에서도 자외선(ultra violet, UV) 조사가 가장 큰 요인으로 꼽힌다. 반복적인 자외선 조사에 의해 진행되는 피부노화를 광노화라고 하며 그 가장 큰 특징으로는 콜라겐 섬유와 엘라스틴의 감소로 야기되는 주름을 들 수 있다. 본 연구에서는 제주에서 채집한 바위수국의 추출물 및 분획물의 항산화 및 자외선으로 인한 피부노화 예방(anti-photoaging) 효능을 확인하고, 활성물질을 분리하여 광노화 예방 효능과 그 메커니즘을 확인하였다. 실험에 사용된 바위수국은 범의귀과의 덩굴성 식물로 바위면이나 나무줄기 등에 붙어서 자라며, 한국(제주, 울릉도)과 일본에 분포한다. 바위수국 추출물과 분획물에서 총 페놀 함량. 총 플라보이드 함량, DPPH 및 ABTS 라디칼소거 활성의 항산화 실험 결과, 부탄올과 에틸아세테이트 분획층에서 강력한 항산화 활성이 관찰되었다. 또한 UVA를 조사한 인간 진피 섬유아세포 (human dermal fibroblast, HDF)데 대한 콜라겐 분해효소인 matrix metalloproteinase-1(MMP-1) 생성 억제 활성을 확인한 결과, 부탄올 분획층이 세포 생장 저해 없이 가장 우수한 효능이 확인되었다. 따라서 부탄올 분획층에서 주요 성분 분리 실험을 수행하여 총 4개의 화합물을 분리하였다; Chlorogenic acid (1), Quercetin-3-O-glucosyl-(1-2)-rhamnoside (2), Quercetin-3-O-xylosyl-(1-2)-rhamnoside (3), Quercitrin (4). 분리한 4개의 물질의 MMP-1 생성 억제 활성을 비교한 결과 화합물 2가 세포독성 없이 MMP-1 생성 억제 효능이 우수하였고, 이후 화합물 2의 광노화 예방 효능과 그 메커니즘을 확인하였다. 화합물 2는 MMP-1의 생성을 억제할 뿐만 아니라 procollagen type I의 생성을 증가시켰으며, MMP-1 생성에 관여하는 mitogen-activated protein kinase (MAPK)/activator protein-1 (AP-1) 신호전달경로를 하향 조절하며, 콜라겐 생성과 관련된 Transforming growth factor-β (TGF-β)/Smad 신호전달경로를 상향 조절하여 UVA에 의한 광노화 예방에 효능을 나타내었다. 이러한 결과들을 바탕으로, 바위수국은 항노화(anti-aging) 기능성 화장품 및 이너뷰티 기능성 식품 소재로 개발이 가능할 것으로 기대된다.

  • PDF

Non-alcoholic Fatty Liver Disease Classification using Gray Level Co-Ocurrence Matrix and Artificial Neural Network on Non-alcoholic Fatty Liver Ultrasound Images (비알콜성 지방간 초음파 영상에 GLCM과 인공신경망을 적용한 비알콜성 지방간 질환 분류)

  • Ji-Yul Kim;Soo-Young Ye
    • Journal of the Korean Society of Radiology
    • /
    • v.17 no.5
    • /
    • pp.735-742
    • /
    • 2023
  • Non-alcoholic fatty liver disease is an independent risk factor for the development of cardiovascular disease, diabetes, hypertension, and kidney disease, and the clinical importance of non-alcoholic fatty liver disease has recently been increasing. In this study, we aim to extract feature values by applying GLCM, a texture analysis method, to ultrasound images of patients with non-alcoholic fatty liver disease. By applying an artificial neural network model using extracted feature values, we would like to classify the degree of fat deposition in non-alcoholic fatty liver into normal liver, mild fatty liver, moderate fatty liver, and severe fatty liver. As a result of applying the GLCM algorithm, the parameters Autocorrelation, Sum of squares, Sum average, and sum variance showed a tendency for the average value of the feature values to increase as it progressed from mild fatty liver to moderate fatty liver to severe fatty liver. The four parameters of Autocorrelation, Sum of squares, Sum average, and sum variance extracted by applying the GLCM algorithm to ultrasound images of non-alcoholic fatty liver disease were applied as inputs to the artificial neural network model. The classification accuracy was evaluated by applying the GLCM algorithm to the ultrasound images of non-alcoholic fatty liver disease and applying the extracted images to an artificial neural network, showing a high accuracy of 92.5%. Through these results, we would like to present the results of this study as basic data when conducting a texture analysis GLCM study on ultrasound images of patients with non-alcoholic fatty liver disease.

The distribution of Jeju coastal sand dune plants and its restoration implications (제주 해안사구 식물 분포와 복원을 위한 의미)

  • Kim, Kee Dae
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.27 no.1
    • /
    • pp.31-44
    • /
    • 2024
  • The coastal dune ecosystem is one of the ecosystems under the most development pressure in Korea. Therefore, it is necessary to study the ecological location and related ecological phenomena of coastal dune plants, but related studies are lacking. Through this study, we intend to conduct research on the structure and restoration of dune plants, focusing on the coastal dunes in Jeju Island, which are affected by artificial development pressure and the continuous increase in tourists among many coastal dunes in Korea. Ecosystems of coastal sand dunes for vegetation survey in Jeju Island are selected based on naturalness and preservation. In this study, 23 major coastal dunes on Jeju Island including Udo were selected. In the coastal dunes of Jeju Island, a whole species survey and quadrat survey were carried out. The vegetation survey at study sites were conducted on May to September 2022, when the vegetation is clearly visible. At the survey site, the dune area was identified at the beginning and the plant species were recorded until no more new species appeared. Vegetation survey in the field was performed by 103 quadrat establishments and was conducted using Braun-Blanquet method. A total of 277 species appeared, and the most common species were Vitex rotundifolia and Calystegia soldanella. The frequency of both Vitex rotundifolia and Calystegia soldanella was approximately over 90%. The proportion of woody and herbaceous in all emerging species was 7.2% and 92.8%, respectively. The total number of species found in the quadrat survey was 98. As a result of classifying plant communities based on species dominance in the quadrats, it was analyzed into 30 plant communities. The plant communities that appeared with a frequency of 2 or more on the main island of Jeju were Vitex rotundifolia, Imperata cylindrica var. koenigii, Ischaemum antephoroides, Wedelia prostrata, Elymus mollis, Calystegia soldanella, Artemisia scoparia, and Tetragonia tetragonoides. The DCCA(detrended canonical correspondence analysis) based on the vegetation and environment factor matrix showed that the height and covers of the dominant plant species explain significantly the variation and distribution of coastal sand dune species on Jeju island. Thus, we may propose a plan to restore the coastal dunes of Jeju island as helping colonization and establishment of mainly sand dune native perennials and trees, preserving native plant communities that are declining and preserving present tree strips of Pinus thunbergii, Litsea japonica, Pittosporum tobira and Vitex rotundifolia.

Single-Channel Seismic Data Processing via Singular Spectrum Analysis (특이 스펙트럼 분석 기반 단일 채널 탄성파 자료처리 연구)

  • Woodon Jeong;Chanhee Lee;Seung-Goo Kang
    • Geophysics and Geophysical Exploration
    • /
    • v.27 no.2
    • /
    • pp.91-107
    • /
    • 2024
  • Single-channel seismic exploration has proven effective in delineating subsurface geological structures using small-scale survey systems. The seismic data acquired through zero- or near-offset methods directly capture subsurface features along the vertical axis, facilitating the construction of corresponding seismic sections. However, substantial noise in single-channel seismic data hampers precise interpretation because of the low signal-to-noise ratio. This study introduces a novel approach that integrate noise reduction and signal enhancement via matrix rank optimization to address this issue. Unlike conventional rank-reduction methods, which retain selected singular values to mitigate random noise, our method optimizes the entire singular value spectrum, thus effectively tackling both random and erratic noises commonly found in environments with low signal-to-noise ratio. Additionally, to enhance the horizontal continuity of seismic events and mitigate signal loss during noise reduction, we introduced an adaptive weighting factor computed from the eigenimage of the seismic section. To access the robustness of the proposed method, we conducted numerical experiments using single-channel Sparker seismic data from the Chukchi Plateau in the Arctic Ocean. The results demonstrated that the seismic sections had significantly improved signal-to-noise ratios and minimal signal loss. These advancements hold promise for enhancing single-channel and high-resolution seismic surveys and aiding in the identification of marine development and submarine geological hazards in domestic coastal areas.

The Effect of the IGF-I treated Gingival and Periodontal Ligament Fibroblast on Osteoblasts (IGF-I으로 처리한 치은 및 치주인대 섬유모세포가 골모세포에 미치는 영향)

  • Kim, Mi-Jeong;Yang, Won-Sik
    • The korean journal of orthodontics
    • /
    • v.31 no.6 s.89
    • /
    • pp.589-600
    • /
    • 2001
  • Insulin-like growth factor I (IGF-I) has the local tissue regulating actions. In bone, IGF-I increases the replication of osteoblastic lineage, probably preosteoblasts, and enhances osteoblastic collagen synthesis and matrix composition rates. The purpose of this study was to investigate the local regulatory effect of IGF-I on periodontium totally, both in an autocrine and paracrine manner. To examine the effect of IGF-I directly on osteoblast (OB) of test rats, and indirectlv on OB via periodontal ligament fibroblast (PDLF), and the effect of gingival fibroblast (GF) on OB via cellular paracrine manner for the understanding of humoral action of adjacent tissue, GF and PDLF were obtained from male Sprague-Dawley rats of six to eight weeks of age. OB was obtained iron frontal and parietal calvarial bone of Sprague-Dawley 21day-old-fetus. After each tell was Incubated 24 hours, for collecting conditioned medium, different concentrations of IGF-I (1,10,100 ng/ml,1ml/well) was adding in the GF, PDLF cells, and the supernatant from these cultures was put into the primary OB culture with $1{\times}10^4$cell/ml/well. The experimental group was divided into six groups control OB, IGF-I treated OB, OB culture with conditioned medium from PDLF, OB culture with conditioned medium from IGF-I treated PDLF, OB culture with conditioned medium from GF, OB culture with conditioned medium from IGF-I treated GF. After final IGF-I treatment, OB was Incubated for 24 hours, and alkaline phosphatase activity assay, BMP expression, cell proliferation measurement using MTT assay, total protein measurement, Collagen synthesis assay using western blot, and examination of bone nodule synthesis were done. Alkaline phosphatase expressions were increased in the group of PDLF-IGF-I supernatant treatment. Direct IGF-I treatment with concentrations of 100ng/m1 showed increased viable tell number measured by MTT assay. And IGF-I treatment did not increase total protein amount. The entire experimental group showed BMP2, 4 expression in western blot, and there was no significant difference between control and experimental groups. These results suggested that supernatant from PDLF effects on increasing cellular activities of OB regardless of IGF-I, and at high concentration, IGF-I increases OB tell proliferation.

  • PDF

The Ability of Cervus Elaphus Sibiricus Herbal Acupuncture to Inhibit the Generation of Inflammatory Enzymes on Collagen-induced Arthritis Mice (녹용약침(鹿茸藥鍼)이 CIA 모델 생쥐의 염증인자 생성억제에 미치는 영향)

  • Hwang, Jong-Soon;Hwang, Ji-Hye;Lee, Hyun-Jin;Lee, Dong-Gun;Kang, Min-Joo;Back, Song-Ook;Cho, Hyun-Seok;Kim, Kyung-Ho;Kim, Kap-Sung
    • Journal of Acupuncture Research
    • /
    • v.24 no.6
    • /
    • pp.1-14
    • /
    • 2007
  • Backgrounds : Rheumatoid Arthritis(RA) is known as the chronic inflammatory diseasethat induces persistent inflammation in the joint cavity. The destruction of cartilage occurs as the result of bones destoyed by pannus, several influential cytokines induced by the synovial capsulitis, varieties of proteinases, $O_2$ radicals, and the secondary degenerative changes of articular cartilage. The type 2 collagen-induced arthritis model is used in recent experimental research on rheumatoid arthritis. Cervus elaphus sibiricus (Nockyong) has the effect of relieving pain by nourishing the muscles, joints, and bones. It is also known to be efficacious in promoting and enhancing the immune system. The objective of this study was to investigate the effect of Cervus elaphus sibiricus herbal acupuncture to inhibit the generation of proinflammatory enzyme on type 2 collagen-induced arthritis. I investigated the inhibition of mRNA transcription of MIF(macrophage migration inhibitory factor), $TNF-{\alpha}$(Tumor necrosis $factor-{\alpha}$) and MMP-9 (matrix metalloproteinase-9) of Cervus elaphus sibiricus herbal acupuncture using an in vitro test. Also investigated was the inhibition of differentiation of Th 1 cells and activation of cytokines(MIF, $TNF-{\alpha}$, IL-6, MMP-9), which are known to cause initial RA ,and are also related to the morphology of the synovial membranes of the joint capsule, by an in vivo test, using CIA(collagen induced arthritis) model mice. Materials & methods : The laboratory animals used in this experiment were 4 week-old DBA female mice, weighing approximately 20 grams, and adjusted to the laboratory environment. The experiment was divided into the normal group(NOR)-no treated group, control group(CON)-CIA induced group, and sample group(SAM)-Cervus elaphus sibiricus herbal acupuncture treated group. RA was induced in the mice via injection of $50{\mu}{\ell}$ C II mixed CFA. The Cervus elaphus sibiricus herbal acupuncture solution was applied on $GB_{35}$(陽陵泉) for 26 days from the 3rd day of RA inducement. The concentration of the solution was determined via a MTT assay. To research the effect on the expression of MIF, $TNF-{\alpha}$ and MMP-9 mRNA, RT-PCR was performed on synovial membrane cells from the knee joint of CIA mice. C II induced RA knee joint's histo-chemical synovial membrane was observed using a specimen model via the Hematoxilin and Eosin dying technique. Results : The expression of mRNA of RA-related cytokines such as MIF, $TNF-{\alpha}$, and MMP-9 dosedependently decreased in the cell from the synovial membranes of the joint, which is treated with Cervus elaphus sibiricus herbal acupuncture solution. In mice treated with Cervus elaphus sibiricusherbal acupuncture, the damage of synovial membranes of the joint was lessened, and differentiation of Th 1 cells was suppressed. The activation of RA-related cytokines such as MIF was suppressed, and the generation of $TNF-{\alpha}$ and MMP-9 showed a statistically significant decreas. Conclusions : It is speculated that Cervus elaphus sibiricus herbal acupuncture has the therapeutic effect of palliating the damage of the tissue impaired by RA by inhibition of the initial RA progression and by regulating excessive differentiation of Th 1 cell as it suppresses the generation of RA-related cytokines during the highest stage of RA by acting on pro-inflammatory enzymes.

  • PDF

Geochemical Characteristics and Heavy Metal Pollutions in the Surface Sediments of Oyster Farms in Goseong Bay, Korea (고성만 굴 양식장 표층퇴적물의 지화학적특성과 중금속 오염에 관한 연구)

  • Kang, Ju-Hyun;Lee, Sang-Jun;Jeong, Woo-Geon;Cho, Sang-Man
    • The Korean Journal of Malacology
    • /
    • v.28 no.3
    • /
    • pp.233-244
    • /
    • 2012
  • Goseong bay, located in southeast sea of Korea with an area of 2,100 ha, is a semi-enclosed bay well-known for oyster farming cultured in an extended range of 148 ha. The objective of this study is to provide the fundamental data in order to manage the effective sea area. A total 26 of surface sediment were collected from Goseong bay to evaluate their sedimentary environment and heavy metals. The loss on Ignition (LOI), C/N ratio, acid volatile sulfide (AVS) and heavy metals were analyzed. loss on ignition (LOI) of surface sediment range from 1.00% to 3.03% (average 2.00%). The carbonate content ranges from 0.52% to 4.29% (average 2.37%). C/N ratio of organic matter showed that most part of organic matter comes from neighboring continent. Acid volatile sulfide (AVS) value of surface sediment from 0.02 mg/g to 1.43 mg/g (average 0.24 mg/g). A ten element of surface sediments (Al, As, Cd, Cr, Cu, Hg, Ni, Pb, V, Zn) were calculated by enrichment factor (Ef) and the results show that some areas are highly polluted with respect Cu and Hg. The correlation matrix displays the existence of remarkable levels of correlation with both positive and negative values among different variable pairs. LOI and AVS showed both positive values. LOI and AVS values falls under 2% and 1%. Therefore, Goseong bay showed good in quality of sediment.

Apolipoprotein A1 Inhibits TGF-β1-Induced Epithelial-to-Mesenchymal Transition of Alveolar Epithelial Cells

  • Baek, Ae Rin;Lee, Ji Min;Seo, Hyun Jung;Park, Jong Sook;Lee, June Hyuk;Park, Sung Woo;Jang, An Soo;Kim, Do Jin;Koh, Eun Suk;Uh, Soo Taek;Kim, Yong Hoon;Park, Choon Sik
    • Tuberculosis and Respiratory Diseases
    • /
    • v.79 no.3
    • /
    • pp.143-152
    • /
    • 2016
  • Background: Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal lung disease characterized by the accumulation of excessive fibroblasts and myofibroblasts in the extracellular matrix. The transforming growth factor ${\beta}1$ (TGF-${\beta}1$)-induced epithelial-to-mesenchymal transition (EMT) is thought to be a possible source of fibroblasts/myofibroblasts in IPF lungs. We have previously reported that apolipoprotein A1 (ApoA1) has anti-fibrotic activity in experimental lung fibrosis. In this study, we determine whether ApoA1 modulates TGF-${\beta}1$-induced EMT in experimental lung fibrosis and clarify its mechanism of action. Methods: The A549 alveolar epithelial cell line was treated with TGF-${\beta}1$ with or without ApoA1. Morphological changes and expression of EMT-related markers, including E-cadherin, N-cadherin, and ${\alpha}$-smooth muscle actin were evaluated. Expressions of Smad and non-Smad mediators and TGF-${\beta}1$ receptor type 1 ($T{\beta}RI$) and type 2 ($T{\beta}RII$) were measured. The silica-induced lung fibrosis model was established using ApoA1 overexpressing transgenic mice. Results: TGF-${\beta}1$-treated A549 cells were changed to the mesenchymal morphology with less E-cadherin and more N-cadherin expression. The addition of ApoA1 inhibited the TGF-${\beta}1$-induced change of the EMT phenotype. ApoA1 inhibited the TGF-${\beta}1$-induced increase in the phosphorylation of Smad2 and 3 as well as that of ERK and p38 mitogen-activated protein kinase mediators. In addition, ApoA1 reduced the TGF-${\beta}1$-induced increase in $T{\beta}RI$ and $T{\beta}RII$ expression. In a mouse model of silica-induced lung fibrosis, ApoA1 overexpression reduced the silica-mediated effects, which were increased N-cadherin and decreased E-cadherin expression in the alveolar epithelium. Conclusion: Our data demonstrate that ApoA1 inhibits TGF-${\beta}1$-induced EMT in experimental lung fibrosis.

Effect of Cervi Pantotrichum Cornu Herbal acupuncture on protease activities, antioxidant in Rheumatoid arthritis rats (류마티스 관절염 실험용쥐의 활액에서 단백분해효소의 활성 및 항산화에 대한 녹용약침의 효과)

  • Park, Sang-Dong;Kim, Min-Jeong;Lee, A-Ram;Jang, Jun-Hyouk;Kim, Kyung-Ho
    • Journal of Acupuncture Research
    • /
    • v.19 no.2
    • /
    • pp.51-64
    • /
    • 2002
  • We have compared(using the same series of experimental tissue samples) the levels of proteolytic enzyme activities and free radical-induced protein damage in synovial fluid from RA and CPH cases. Many protease types showed significantly increased (typically by a factor of approximately 2-3-fold) activity in RA, compared to normal rats. However, CPH significantly reduced the cytoplasmic enzyme activities of arginyl aminopeptidase, leucyl aminopeptidase, pyroglutamyl aminopeptidase, tripeptidyl aminopeptidase, and proline endopeptidase to almost about 1/10 each. For the Iysosomal proteases, synovial fluid samples from RA rats, CPH significantly reduced the enzyme activities of cathepsin B, dipeptidyl aminopeptidase I and dipeptidyl aminopeptidase II. In extracellular matrix degrading(collagenase, tissue elastase) and leukocyte as sociated proteases (leukocyte elastase, cathepsin G), CPH decreased these enzyme activities of collagenase, tissue elastase and leukocyte associated elastase in RA. In cytoplasmic and lysosomal protease activities in plasma from RA. CPH and normal plasma samples were not significantly different, suggesting that altered activity of plasma proteases (particularly those enzymes putatively involved in the immune response) is not a contributory factor in the pathogenesis of RA. In addition, the level of free radical induced damage to synovial fluid proteins was approximately twice that in RA, compared with CPH. CPH significantly decreased the level of ROS induced oxidative damage to synovial fluid proteins (quantified as protein carbonyl derivative). Therefore we conclude that both proteolytic enzymes and free radicals are likely to be of equal potential importance as damaging agents in the pathogenesis of inflammatory joint disease, and that the design of novel therapeutic strategies for patients with the latter disorder should include both protease inhibitory and free radical scavenging elements. In addition, the protease inhibitory element should be designed to inhibit the action of a broad range of protease mechanistic types (i.e. cysteine-, metallo- and serine- proteinases and peptidases). However, increased protein damage induced by ROS could not be rationalised in terms of compromised antioxidant total capacity, since the latter was not significantly altered in RA synovial fluid or plasma compared with CPH.

  • PDF

CORRELATION BETWEEN VASCULAR ENDOTHELIAL GRWOTH FACTOR SIGNALING AND MINERALIZATION DURING OSTEOBLASTIC DIFFERENTIATION OF CULTURED HUMAN PERIOSTEAL-DERIVED CELLS (배양된 인간 골막기원세포의 조골세포 분화과정에서 골기질 형성정도와 혈관내피세포성장인자 신호와의 상관관계)

  • Park, Bong-Wook;Byun, June-Ho;Ryu, Young-Mo;Hah, Young-Sool;Kim, Deok-Ryong;Cho, Yeong-Cheol;Sung, Iel-Yong;Kim, Jong-Ryoul
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.29 no.3
    • /
    • pp.197-205
    • /
    • 2007
  • Angiogenesis is a essential part for bone formation and bone fracture healing. Vascular endothelial growth factor (VEGF), one of the most important molecules among many angiogenic factors, is a specific mitogen for vascular endothelial cells. VEGF-mediated angiogenesis is required for bone formation and repair. However, the effect of VEGF on osteoblastic cells during osteogenesis is still controversial. In recent days, substantial progress have been made toward developing tissue-engineered alternatives to autologous bone grafting for maxillofacial bony defects. Periosteum has received considerable interest as a better source of adult stem cells. Periosteum has the advantage of easy harvest and contains various cell types and progenitor cells that are able to differentiate into a several mesenchymal lineages, including bone. Several studies have reported the bone formation potential of periosteal cells, however, the correlation between VEGF signaling and cultured human periosteal cell-derived osteogenesis has not been fully investigated yet. The purpose of this study was to examine the correlation between VEGF signaling and cultured human periosteal-derived cells osteogenesis. Periosteal tissues of $5\;{\times}\;20\;mm$ were obtained from mandible during surgical extraction of lower impacted third molar from 3 patients. Periosteal-derived cells were introduced into the cell culture and were subcultured once they reached confluence. After passage 3, the periosteal-derived cells were further cultured for 42 days in an osteogenic inductive culture medium containing dexamethasone, ascorbic acid, and ${\beta}-glycerophosphate$. We evaluated the alkaline phosphatase (ALP) activity, the expression of Runx2 and VEGF, alizarin red S staining, and the quantification of osteocalcin and VEGF secretion in the periosteal-derived cells. The ALP activity increased rapidly up to day 14, followed by decrease in activity to day 35. Runx2 was expressed strongly at day 7, followed by decreased expression at day 14, and its expression was not observed thereafter. Both VEGF 165 and VEGF 121 were expressed strongly at day 35 and 42 of culture, particularly during the later stages of differentiation. Alizarin red S-positive nodules were first observed on day 14 and then increased in number during the entire culture period. Osteocalcin and VEGF were first detected in the culture medium on day 14, and their levels increased thereafter in a time-dependent manner. These results suggest that VEGF secretion from cultured human periosteal-derived cells increases along with mineralization process of the extracellular matrix. The level of VEGF secretion from periosteal-derived cells might depend on the extent of osteoblastic differentiation.