• Toxicological Research
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• 제27권3호
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• pp.161-166
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• 2011

Carbon black, a particulate form of pure elemental carbon, is an industrial chemical with the high potential of occupational exposure. Although the relationship between exposure to particulate matters (PM) and cardiovascular diseases is well established, the cardiovascular risk of carbon black has not been characterized clearly. In this study, the cytotoxicity of carbon black to vascular smooth muscle and endothelial cells were examined to investigate the potential vascular toxicity of carbon black. Carbon black with distinct particle size, N330 (primary size, 28~36 nm) and N990 (250~350 nm) were treated to A-10, rat aortic smooth muscle cells and human umbilical vein endothelial cell line, ECV304, and cell viability was assessed by lactate dehydrogenase (LDH) leakage assay. Treatment of carbon black N990 resulted in the significant reduction of viability in A-10 cells at 100 ${\mu}g$/ml, the highest concentration tested, while N330 failed to cause cell death. Cytotoxicity to ECV304 cells was induced only by N330 at higher concentration, 200 ${\mu}g$/ml, suggesting that ECV304 cells were relatively resistant to carbon black. Treatment of 100 ${\mu}g$/ml N990 led to the elevation of reactive oxygen species (ROS) detected by dichlorodihydrofluorescein (DCF) in A-10 cells. Pretreatment of antioxidants, N-acetylcysteine (NAC) and sulforaphane restored decreased viability of N990-treated A-10 cells, and N-acetylcysteine, but not sulforaphane, attenuated N990-induced ROS generation in A-10 cells. Taken together, present study shows that carbon black is cytotoxic to vascular cells, and the generation of reactive oxygen contributes to the development of cytotoxicity. ROS scavenging antioxidant could be a potential strategy to attenuate the toxicity induced by carbon black exposure.

• Applied Microscopy
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• 제23권1호
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• pp.91-108
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• 1993

The relationship of cartilage canals to initial osteogenesis of primary ossification center of developing vertebrae in human fetuses ranging from 50mm to 260mm in crown rump length was studied by light and electron microscopy. The cartiage canals of the thoracic vertebrae were first observed at 60mm fetus. Cartilage canals were identified as vascular channels arising from perichondrium surfaces. A number of cartilage canals were observed around the primary center of ossification at 80mm fetus. At 120mm fetus, cartilage canals of the bodies of vertebra were increased. Eventually the canals were eroded from the main medullary cavity and remained at only peripheral regions of growth cartilage. Superficial, intermediate, and deep canals were identified by the characteristics of cartilage cells. Fibroblasts, undifferentiated mesenchymal cells, and vacuolated macrophages were observed adjacent to the matrix of resting cartilage cells in the superficial canal. Fibroblasts and mesenchymal cells were densely packed at the tip of canal, giving an epithelial appearance to the clustered cell in the intermediate canal. Vacuolated macrophages were in contact with matrix of hypertrophied cartilage. The thick-walled vessels in the intermediate and deep canals consisted of typical endothelial cells, but in the newly formed vessels contained mesenchymal cells and fibroblasts incorporated into the vessel wall. During lengthening of cartilage canal, the matrix of cartilage cells were invaded by newly formed capillaries and vacuolated macrophages. At the deep canal, the lateral wall of the canal terminated in matrix containing calcified cartilage. The mesenchymal cells began to differentiate into osteoblasts adjacent to the calcified matrix. The results indicate that the connective tissue cells within the cartilage canals proliferate and differentiate into osteoblasts at the site of primary ossification center.

• Journal of Korean Neurosurgical Society
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• 제30권6호
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• pp.683-687
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• 2001

Objective : Angiogenesis, the proliferation of capillary endothelial cells, is a vital component in the development, progression, and metastasis of many human tumors. Vascular endothelial growth factor(VEGF) is an endothelial cell-specific mitogen and induces angiogenesis and vascular permeability. The features of glioblastoma, distinct from low grade astrocytomas, are the presence of necroses and vascular endothelial proliferation. In this study, we investigated VEGF expression in the different grades of astrocytomas and determined whether VEGF expression correlates with development of glioblastoma and progression of astrocytomas. Patients and Methods : Forty seven patients with astrocytic tumors(24 males and 23 females), aged 3 to 65 years, were evaluated. Immunohistochemical staining was carried out using labelled streptavidin biotin method and primary antibody was a antirabbit polyclonal Ab against N-terminus region of VEGF165(Oncogene research product, MA, USA). Immunoreactivity(IR) was classified into no IR(absent or a trace of stain), moderate IR and intense IR by level of staining amount and intensity. Results : Six pilocytic astrocytomas showed 3 no IR and 3 moderate IR, 10 astrocytomas showed 2 no IR, 6 moderate IR and 2 intense IR, 12 anaplastic astrocytomas showed I no IR, 7 moderate IR and 4 intense IR and 19 glioblastomas showed 1 no IR, 11 moderate IR and 7 intense IR. Immunoreactivity was significantly different between low and high grade of tumors but there was no significant difference between anaplastic astrocytomas and glioblastomas. Gemistocytic tumor cells represented the predominent VEGF-immunoreactive cell types, as compared with compactly-arranged small tumor cells. In glioblastomas VEGF IR was observed in both perinecrotic and vital tumor areas. Conclusion : VEGF seems to be a important angiogenic factor in anaplastic astrocytomas and glioblastomas and VEGF expression may contribute to neovascularization of human astrocytomas.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권2호
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• pp.55-65
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• 2009

Purpose: We determined the therapeutic effects of blockade of epidermal growth factor(EGF) and vascular endothelial growth factor(VEGF) receptor tyrosine kinases on the growth of oral squamous cell carcinoma(OSCC) xenografted in athymic nude mice. Experimental Design: We investigated the in vivo antitumor effects of a tyrosine kinase inhibitor for EGFR and VEGFR-2, AEE788 in a mouth floor(orthotopic) tumor model. Nude mice with orthotopic tumors were randomized to receive AEE788, paclitaxel, a combination of AEE788 and paclitaxel, or control. Antitumor mechanisms of AEE788 were determined by immunohistochemical/immunofluorescent and apoptosis assays. Results: Tumors of mice treated with AEE788 demonstrated down-regulation of phosphorylated EGFR, phosphorylated VEGFR and their downstream mediators(pMAPK and pAkt), decreased proliferative index, decreased microvessel density(MVD). As a result, growth of the primary tumor and nodal metastatic potentials were inhibited by AEE788. Conclusion: These data show that EGFR and VEGFR can be molecular targets for the treatment of OSCC.

• Archives of Plastic Surgery
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• 제37권3호
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• pp.239-244
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• 2010

Purpose: Intravascular papillary endothelial hyperplasia (IPEH), also known as Masson's pseudoangiosarcoma, is a rare disease which is now considered as a reactive process of the endothelium rather than a benign neoplasm. It can occur in any blood vessels in the body but more common in the head and neck region as a solitary, often tender, bluish or reddish nodule. IPEH is characterized by the development of endothelial-lined papillary projections in a vascular lumen, usually associated with thrombotic material, the endothelial cells in the papillary structures showing only slight atypia and occasional mitotic Figures, the absence of tissue necrosis. Methods: 8 patients with IPEH were enrolled in the study from 2002 to 2007. All 8 lesions were surgically excised for histopathologic diagnosis. Results: 4 patients were female. The duration of the lesions ranged from 3 months to 15 years. The tumors were first noted between the ages of 20 and 72 years. 4 patients had lesions on the head; 2 on the toe; 1 on the back; and 1 on the finger, respectively. All lesions were solitary, ranged in size from 2 mm to 27 mm. There were no recurrences. Conclusion: The clinical appearance of IPEH is not specific, presented as a primary neoplasm, and the diagnosis can be established by microscopic examination. Complete surgical excision is the best choice of therapy for patients with IPEH, and is both diagnostic and curative. Awareness of this lesion will prevent incorrect diagnosis and overly aggressive treatment.

• Journal of Gastric Cancer
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• 제2권4호
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• pp.195-199
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• 2002

Purpose: Angiogenesis is essential for tumor growth and metastasis and depends on the production of angiogenic factors that are secreted by tumor cells. Vascular endothelial growth factor (VEGF) is the most significant angiogenic factor and a selective mitogen for endothelial cells. VEGF, also known as the vascular permeability factor, acts on endothelial cells to increase microvascular permeability and directly stimulate the growth of new blood vessels. Several studies have reported that the expression of VEGF is correlated with hematogenous recurrence via angiogenesis in gastric carcinomas. This research evaluated the relationship between the expression of VEGF and hepatic and peritoneal recurrence in gastric carcinomas. Materials and Methods: Thirty specimens resected from patients with primary gastric carcinomas who had undergone curative resections were divided into three group: Group I, early gastric carcinomas without recurrence; Group II, advanced gastric carcinomas with hepatic recurrence; and Group III, advanced gastric carcinomas with peritoneal recurrence. The expression of VEGF and the density of the microvessel count were examined using immunohistochemistry. Results: 1) The expression of VEGF in Group II and Group III ($63.2\pm\24.3\%$) was stronger than that in Group I ($7\pm\4.2\%$). The expression of VEGF in Group II ($76.5\pm\13.2\%$) was stronger than that of the Group III ($50\pm\14.2\%$) (P<0.05). 2) The microvessel count in Group II ($49.9\pm14.5$) was more than that in Group I ($8.6\pm2.6$) and Group III ($29.1\pm18.1$) (P<0.05). 3) The microvessel count was increased significantly with increasing the expression of VEGF. Conclusions: The expression of VEGF is associated with advanced stomach cancer and hepatic recurrence has a higher expression of VEGF than peritoneal recurrence with neovascularization. Thus the expression of VEGF can be considered to be a useful indicator of recurrence in gastric carcinoma and especially in hepatic recurrence.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제38권3호
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• pp.145-151
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• 2012

Objectives: Angiogenesis and lymphangiogenesis are correlated with tumor growth and lymph node metastasis in cases of oral squamous cell carcinoma (OSCC). Endoglin is one of the representative vascular endothelial cell markers. Podoplanin is also a representative marker used in order to detect lymphatic endothelial cells. The aim of this study was to determine the correlation between the expression of endoglin/podoplanin and clinical variables associated with OSCC progression. Materials and Methods: Paraffin embedded tissue specimens from 21 patients diagnosed with OSCC were used in this study. Ten patients were diagnosed with early clinical stage (I or II) and 11 patients with advanced clinical stage (III or IV) OSCC. Five patients had positive lymph node involvement. Primary antibodies for endoglin and podoplanin were used to perform the immunohistochemical detection of the vascular and lymphatic endothelial cells. The expression of endoglin and podoplanin was examined by an image analysis program in the three most highly expressed regions of each specimen. Results: The average endoglin expression was observed to be $1.691{\pm}0.920$ in the advanced stage (III, IV) specimens and $0.797{\pm}0.583$ in the early stage (I, II) specimens (P=0.020). The average expression of podoplanin was $0.286{\pm}0.228$ in the advance stage (III, IV) specimens and $0.374{\pm}0.157$ in the early stage (I, II) specimens (P>0.05). There was no statistically significant difference in the expression of endoglin and podoplanin, regardless of whether or not the lymph node was positive. Conclusion: The expression of endoglin was significantly higher in the advanced stage specimens than that in the early stage specimens. Therefore, we concluded that endoglin is a useful molecular marker for use in the evaluation of the progression of OSCC.

• Molecules and Cells
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• 제41권3호
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• pp.224-233
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• 2018

Primary cilia are solitary, non-motile, axonemal microtubule-based antenna-like organelles that project from the plasma membrane of most mammalian cells and are implicated in transducing hedgehog signals during development. It was recently proposed that aberrant SHH signaling may be implicated in the progression of idiopathic pulmonary fibrosis (IPF). However, the distribution and role of primary cilia in IPF remains unclear. Here, we clearly observed the primary cilia in alveolar epithelial cells, fibroblasts, and endothelial cells of human normal lung tissue. Then, we investigated the distribution of primary cilia in human IPF tissue samples using immunofluorescence. Tissues from six IPF cases showed an increase in the number of primary cilia in alveolar cells and fibroblasts. In addition, we observed an increase in ciliogenesis related genes such as IFT20 and IFT88 in IPF. Since major components of the SHH signaling pathway are known to be localized in primary cilia, we quantified the mRNA expression of the SHH signaling components using qRT-PCR in both IPF and control lung. mRNA levels of SHH, the coreceptor SMO, and the transcription factors GLI1 and GLI2 were upregulated in IPF compared with control. Furthermore, the nuclear localization of GLI1 was observed mainly in alveolar epithelia and fibroblasts. In addition, we showed that defective KIF3A-mediated ciliary loss in human type II alveolar epithelial cell lines leads to disruption of SHH signaling. These results indicate that a significant increase in the number of primary cilia in IPF contributes to the upregulation of SHH signals.

• Tuberculosis and Respiratory Diseases
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• 제47권2호
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• pp.150-160
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• 1999

연구배경: CREST 증후군은 전신성 경화증의 이형으로 전신성 경화증에 비교하여 병의 진행이 늦은 것으로 알려져 있다. 하지만 CREST 증후군 환자의 약 50%에서 폐나 심장질환의 증거 없이 폐고혈압이 발생하며, 이러한 환자들의 이년 생존률은 40%로 폐고혈압이 없는 환자에 비해 예후가 매우 나쁘다. 그러나 CREST 증후군에 동반되는 폐고혈압의 원인과 병리기전에 대해서는 전혀 알려진 바 없으며 막연히 원발성 폐고혈압의 이형(variant form) 또는 이차성 폐고혈압으로 분류되고 있다. 총상병변(plexiform lesion) 내 증식된 내피세포의 클론성 검증은 폐고혈압을 원발성과 이차성으로 나누는 기준이 되고 있다. 이에 저자들은 CREST 증후군이 동반된 폐고혈압 환자의 총상병변 내피세포의 클론성을 분석함으로써 CREST 동반된 폐고혈압이 원발성인지 이차성인지를 알아보고자 하였다. 방법: 폐고혈압을 동반한 CREST 증후군 여자환자에서 얻은 폐조직의 파라핀 block을 사용하여 microdissection 방법으로 총상병변내에 증식된 내피세포를 분리한후 X-염색체의 methylation pattern을 이용하여 클론성 분석을 시행하였다. 같은 방법으로 중막 비후를 보이는 혈관의 혈관 평활근과 폐실질의 클론성도 분석하였다. 결과: 14개 총상병변의 '증식된 내피세포'의 클론성 모두 다클론성 이었다. 또한 중막비후가 현저한 5개 폐동맥의 평활근세포 클론성도 모두 다클론성 이었다. 결론: 이상의 결과는 CREST 증후군에 동반되는 폐고혈압이 원발성 폐고혈압과는 다른 병리 기전을 갖는 이차성 폐고혈압임을 시사한다.

• Journal of Korean Neurosurgical Society
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• 제44권4호
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• pp.249-255
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• 2008

Objective : In Moyamoya disease, the primary goal of treatment is to improve collateral circulation through angiogenesis. In the present study, we obtained and sub-cultured bone marrow stromal cells (BMSCs) from rats without a cell-mediated immune response. Then, we injected the labeled BMSCs directly into adjacent temporal muscle during encephalomyosynangiosis (EMS). Three weeks after BMSC transplantation, we examined the survival of the cells and the extent of neovascularization. Methods : We divided 20 rats into a BMSC transplantation group (n=12) and a control group (n=8). Seven days after the induction of chronic cerebral ischemia, an EMS operation was performed, and labeled BMSCs ($1{\times}106^6/100\;{\mu}L$) were injected in the temporal muscle for the transplantation group, while an equivalent amount of culture solution was injected for the control group. Three weeks after the transplantation, temporal muscle and brain tissue were collected for histological examination and western blot analysis. Results : The capillary/muscle ratio in the temporal muscle was increased in the BMSC transplantation group compared to the control group, showing a greater increase of angiogenesis (p<0.05). In the brain tissue, angiogenesis was not significantly different between the two groups. The injected BMSCs in the temporal muscle were vascular endothelial growth factor (VEGF)-positive by immunofluorescence staining. In both temporal muscle and brain tissue, the expression of VEGF by western blot analysis was not much different between the two groups. Conclusion : During EMS in a chronic cerebral ischemia rat model, the injection of BMSCs resulted in accelerated angiogenesis in the temporal muscle compared to the control group.