• Title/Summary/Keyword: Tissue remodeling

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Biocompatible polymeric rods as implants for enhanced cartilage regeneration

  • Yook , Yeo-Joo;Hwang, Jeong-Hyo;Shim, In-Kyung;Lee, Jue-Yeon;Lee, Sang-Young;Ahn, Hyun-Jeong;Lee, Sang-Hoon;Lee, Myung-Chul;Lee, Seung-Jin
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.235.1-235.1
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    • 2003
  • With an aim of obtaining high efficacy in cartilage regeneration, implantable polymeric rods were fabricated. These rod-type matrices were anticipated to perform structural tissue supporting activity and enhance extracellular matrix (ECM) formation by releasing specific agent, DHEA-S, in controlled manner. It is expected that application for the drilling operation on the articular cartilage of OA patients as the implants may promote regeneration of their cartilage. Osteoarthritis (OA) is a degenerative joint disease characterized by progressive loss of articular cartilage, subchondral bone remodeling, spur formation, and synovial inflammation. (omitted)

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Molecular imaging of polarized macrophages in tumors

  • Ran Ji Yoo;Yun-Sang Lee
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.7 no.1
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    • pp.41-49
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    • 2021
  • Diversity and flexibility are two typical hallmarks of macrophages. Two types of macrophages, M1(classically activated macrophages) and M2(alternatively activated macrophages) exist at both ends of the commonly known macrophage polarization. M1 macrophages have inflammatory properties and are primarily responsible for defending against invading bacteria in our body. On the other hand, M2 macrophages are involved in anti-inflammatory responses and tissue remodeling. Polarized migration of macrophages is of increasing interest in regulating the initiation, generation, and resting phases of inflammatory diseases. In this review, it intend to discuss the properties and functions of tumor-associated macrophages based on polarized macrophages that affect inflammatory diseases. In addition, the purpose of this study is to investigate a molecular imaging approach that targets macrophages that affect tumor growth by controlling the polarization of macrophages that affect tumor diagnosis and treatment.

A STUDY ON THE EFFECTS OF EARLY LOADING ON THE SURROUNDING BONE TISSUE OF THE DENTAL IMPLANTS (치과임플랜트 매식후 조기기능이 임플랜트 주위골조직에 미치는 영향에 관한 연구)

  • Park, Hui-Un;Yang, Jae-Ho;Lee, Sun-Hyung
    • The Journal of Korean Academy of Prosthodontics
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    • v.31 no.1
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    • pp.101-127
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    • 1993
  • The purpose of this study was to observe the effects of early loading on the surrounding bone tissue of the implants. 12 ITI HS implants (8 mm) were inserted on the mandible at 3 mongrel dogs. The implants were divided into two groups; the functional group was functioned with crown, and nonfunctional group was functioned without crown. After 3 and 5 months animals were sacrificed and specimens were examined using radiography, light microscopy, scanning electron microscopy. The following results were obtained. 1. On light microscopic and scanning electron microscopic examination, the difference in the amounts of bone attachment between 3 months loaded and unloaded implants were a little. Sometimes more bone attachment were observed in loaded implants. 2. Many osteoids surrounded the fibrous connective tissues indicating of bone remodeling were observed along the outer surface of the implants. 3. On clinical, radiographic, microscopic examination, epithelial downgrowths were not observed and bone attachments to the outer surface of the implants were observed in 3 months loaded and unloaded implants with good oral hygiene. 4. Epithelial downgrowths and crater-like bone resorptions were observed on 5 months loaded and unloaded implants with poor oral hygiene. 5. Many inflammatory cells in the epithelial tissue were packed in the hollow on 5 months loaded implants.

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An Electron Microscopic Study on Healing of Epidermis Following Injury of Skin in Mice (피부손상후 표피치유에 관한 전자현미경적 연구)

  • Kim, Sang-Hee;Ahn, Dong-Choon;Kim, Won-Kyu;Chung, Ho-Sam
    • Applied Microscopy
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    • v.28 no.3
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    • pp.307-314
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    • 1998
  • The author has undertaken this study for demonstrating the relationship between keratinization and proliferation as well as remodeling of epidermis. Healthy ICR strain male mice, weighing about $20\sim25gm$, were used as experimental animals. Under the general anesthesia with ether the skins of experimental animals were subjected to a dorsal, transverse, full-thickness incision with 0.5cm in length, and removed them on 3rd day, 7th day and 2nd week after operation Specimens were prepared for electron microscopic study. The results obtained were as follows: The epidermis of 3rd day group is made up of $7\sim8$ keratinocytes. The new epidermal cells are grown beneath the necrotic tissue. Keratohyaline granules (KHGs) are visible in some granular cells. Various sited-KHGs are seen in granular layer cell, and in spinous cell ribosomes, tonofilaments and lamellar granules are seen. The epidermis of 7th day group is made up of $7\sim8$ keratinocytes. Numerous KHGs are seen in granular layer cells. KHGs are located in granular layer cells as well as spinous layer cells. The epidermis of End week group is composed of one-layered basal cell and $1\sim2$ layered superficial cells. Various sized-KHGs are observed in granular layer cells. The results of the present study suggest that as the epidermis should be keratinized during proliferation and remodeling process, so keratinization of the epidermis would play a major role of wound healing process.

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Angiotensin-(1-9) ameliorates pulmonary arterial hypertension via angiotensin type II receptor

  • Cha, Seung Ah;Park, Byung Mun;Kim, Suhn Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.4
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    • pp.447-456
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    • 2018
  • Angiotensin-(1-9) [Ang-(1-9)], generated from Ang I by Ang II converting enzyme 2, has been reported to have protective effects on cardiac and vascular remodeling. However, there is no report about the effect of Ang-(1-9) on pulmonary hypertension. The aim of the present study is to investigate whether Ang-(1-9) improves pulmonary vascular remodeling in monocrotaline (MCT)-induced pulmonary hypertensive rats. Sprague-Dawley rats received Ang-(1-9) ($576{\mu}g/kg/day$) or saline via osmotic mini-pumps for 3 weeks. Three days after implantation of osmotic mini-pumps, 50 mg/kg MCT or vehicle were subcutaneously injected. MCT caused increases in right ventricular weight and systolic pressure, which were reduced by co-administration of Ang-(1-9). Ang-(1-9) also attenuated endothelial damage and medial hypertrophy of pulmonary arterioles as well as pulmonary fibrosis induced by MCT. The protective effects of Ang-(1-9) against pulmonary hypertension were inhibited by Ang type 2 receptor ($AT_2R$) blocker, but not by Mas receptor blocker. Additionally, the levels of LDH and inflammatory cytokines, such as $TNF-{\alpha}$, MCP-1, $IL-1{\beta}$, and IL-6, in plasma were lower in Ang-(1-9) co-treated MCT group than in vehicle-treated MCT group. Changes in expressions of apoptosis-related proteins such as Bax, Bcl2, Caspase-3 and -9 in the lung tissue of MCT rats were attenuated by the treatment with Ang-(1-9). These results indicate that Ang-(1-9) improves MCT-induced pulmonary hypertension by decreasing apoptosis and inflammatory reaction via $AT_2R$.

Predicting the Role of Osteal Macrophages and Osteocytes in Bone Tissue Network Using a Mathematical Modeling (수학적 모델링을 이용한 골조직 세포 네트워크에서 Osteal Macrophage와 골세포의 역할 예측)

  • Hwang, Soo-Jeong
    • Journal of dental hygiene science
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    • v.18 no.2
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    • pp.130-135
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    • 2018
  • The aim of this study was to investigate the role of osteal macrophages (osteomac) and osteocytes in bone remodeling using a mathematical model. We constructed the bone system with pre-osteoblasts, osteoclasts, osteocytes, and osteomac. Each link of the parameters and ordinary differential equations followed the Graham's model in 2013 except for the parameters of osteomac signaling and osteocytes signaling to link preosteoblasts and osteoblasts. We simulated the changes in each cell and bone volume according to the changes in the parameters of osteomac signaling and osteocytes signaling. The results showed bone volume was unstable and decreased gradually when the effectiveness of osteocytes and osteomac dropped below a certain level. When the parameters of osteomac signaling and osteocytes signaling to link preosteoblasts and osteoblasts had a value less than 1, bone volume increased with the increase in the parameter of osteomac signaling to link preosteoblasts and osteoblasts. Moreover, although the parameter of osteocytes signaling to link preosteoblasts and osteoblasts, increased in case of a small parameter of osteomac signaling, bone volulme decreased. If the parameters of osteomac signaling to link preosteoblasts and osteoblasts were over a certain level, bone volume was positively maintained, despite the parameter of osteocyte signaling to link preosteoblasts and osteoblasts. We suggested the osteomac may affect bone remodeling and may play an important role in bone cell network.

Matrix metalloproteinases: expression and regulation in the endometrium during the estrous cycle and at the maternal-conceptus interface during pregnancy in pigs

  • Inkyu Yoo;Soohyung Lee;Yugyeong Cheon;Hakhyun Ka
    • Animal Bioscience
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    • v.36 no.8
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    • pp.1167-1179
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    • 2023
  • Objective: Matrix metalloproteinases (MMPs) are a family of endoproteases produced by various tissues and cells and play important roles in angiogenesis, tissue repair, immune response, and endometrial remodeling. However, the expression and function of MMPs in the pig endometrium during the estrous cycle and pregnancy have not been fully elucidated. Thus, we determined the expression, localization, and regulation of MMP2, MMP8, MMP9, MMP12, and MMP13 in the endometrium throughout the estrous cycle and at the maternal-conceptus interface during pregnancy in pigs. Methods: Endometrial tissues during the estrous cycle and pregnancy and conceptus and chorioallantoic tissues during pregnancy were obtained and the expression of MMPs was analyzed. The effects of steroid hormones and cytokines on the expression of MMPs were determined in endometrial explant cultures. Results: Expression levels of MMP12 and MMP13 changed during the estrous cycle, while expression of MMP2, MMP9, MMP12, and MMP13 changed during pregnancy. Expression of MMP2, MMP8, and MMP13 mRNAs was cell type-specific at the maternal-conceptus interface. Gelatin zymography showed that enzymatically active MMP2 was present in endometrial tissues. In endometrial explant cultures, estradiol-17β induced the expression of MMP8 and MMP12, progesterone decreased the expression of MMP12, interleukin-1β increased the expression of MMP2, MMP8, MMP9, and MMP13, and interferon-γ increased the expression of MMP2. Conclusion: These results suggest that MMPs expressed in response to steroids and cytokines play an important role in the establishment and maintenance of pregnancy by regulating endometrial remodeling and processing bioactive molecules in pigs.

Pectolinarigenin ameliorated airway inflammation and airway remodeling to exhibit antitussive effect

  • Quan He;Weihua Liu;Xiaomei Ma;Hongxiu Li;Weiqi Feng;Xuzhi Lu;Ying Li;Zi Chen
    • The Korean Journal of Physiology and Pharmacology
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    • v.28 no.3
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    • pp.229-237
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    • 2024
  • Cough is a common symptom of several respiratory diseases. However, frequent coughing from acute to chronic often causes great pain to patients. It may turn into cough variant asthma, which seriously affects people's quality of life. For cough treatment, it is dominated by over-the-counter antitussive drugs, such as asmeton, but most currently available antitussive drugs have serious side effects. Thus, there is a great need for the development of new drugs with potent cough suppressant. BALB/c mice were used to construct mice model with cough to investigate the pharmacological effects of pectolinarigenin (PEC). Hematoxylin-eosin and Masson staining were used to assess lung injury and airway remodeling, and ELISA was used to assess the level of inflammatory factor release. In addition, inflammatory cell counts were measured to assess airway inflammation. Airway hyperresponsiveness assay was used to assess respiratory resistance in mice. Finally, we used Western blotting to explore the potential mechanisms of PEC. We found that PEC could alleviate lung tissue injury and reduce the release of inflammatory factors, inhibit of cough frequency and airway wall collagen deposition in mice model with cough. Meanwhile, PEC inhibited the Ras/ERK/c-Fos pathway to exhibit antitussive effect. Therefore, PEC may be a potential drug for cough suppression.

THE EFFECT OF NEW BONE FORMATION OF ONLAY BONE GRAFT USING VARIOUS GRAFT MATERIALS WITH A TITANIUM CAP ON THE RABBIT CALVARIUM (가토의 두개골에서 티타늄 반구를 이용한 다양한 onlay bone graft시 골형성 능력)

  • Park, Young-Jun;Choi, Guen-Ho;Jang, Jung-Rok;Jung, Seung-Gon;Han, Man-Seung;Yu, Min-Gi;Kook, Min-Suk;Park, Hong-Ju;Ryu, Sun-Youl;Oh, Hee-Kyun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.31 no.6
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    • pp.469-477
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    • 2009
  • Purpose: This study was performed to evaluate the effect of various graft materials used with a titanium cap on the ability of new bone formation in the rabbit calvarium. Materials and Methods: A total of 32 sites of artificial bony defects were prepared on the calvaria of sixteen rabbits by using a trephine bur 8 mm in diameter. Each rabbit had two defect sites. 0.2 mm deep grooves were formed on the calvaria of sixteen rabbits by using a trephine bur 8 mm in diameter for the fixation of a titanium cap. The treatments were performed respectively as follows: without any graft for the control group (n=8), autogenous iliac bone graft for experimental group 1 (n=8), alloplastic bone graft ($SynthoGraft^{(R)}$, USA) for experimental group 2 (n=8), and xenogenic bone graft ($NuOss^{(R)}$, USA) for experimental group 3 (n=8). After the treatments, a titanium cap (8 mm in diameter, 4 mm high, and 0.2 mm thick) was fixed into the groove. At the third and sixth postoperative weeks, rabbits in each group were sacrificed for histological analysis. Results: 1. In gross examination, the surgical sites showed no signs of inflammation or wound dehiscence, and semicircular-shaped bone remodeling was shown both in the experimental and control groups. 2. In histological analysis, the control group at the third week showed bone remodeling along the inner surface of the cap and at the contact region of the calvarium without any specific infiltration of inflammation tissue. Also, there was no soft tissue infiltration. Bone remodeling was observed around the grafted bone and along the inner surface of the titanium cap in experimental group 1, 2, and 3. 3. Histologically, all groups at the sixth week showed the increased area of bone remodeling and maturation compared to those at the third week. In experimental group 2, the grafted bone was partially absorbed by multi nucleated giant cells and new bone was formed by osteoblasts. In group 3, however, resorption of the grafted bone was not observed. 4. Autogenous bone at the third and sixth week showed the most powerful ability of new bone formation. The size of newly formed bone was in decreasing order by autogenous, alloplastic, and heterogenous bone graft. There was no statistically significant difference among autogenous, alloplastic, and heterogenous bones(p>0.05). Summary: This result suggests that autogenous bone is the best choice for new bone formation, but when autogenous bone graft is in limited availability, alloplastic and xenogenic bone graft also can be an alternative bone graft material to use with a suitably guided membrane.

The Effects of Various Extracellular Matrices on Motility of Cultured MC3T3-E1 Cell (다양한 세포외기질이 배양 골아세포의 이동에 미치는 영향)

  • Park, Beyoung Yun;Seo, Sang Woo;Lee, Won Jai;Ryu, Chang Woo;Rah, Dong Kyun;Son, Hyun Joo;Park, Jong Chul
    • Archives of Plastic Surgery
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    • v.32 no.2
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    • pp.143-148
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    • 2005
  • Chemotactic migration of bone forming cell, osteoblast, is an important event during bone formation, bone remodeling, and fracture healing. Migration of cells is mediated by adhesion receptors, such as integrins, that link the cell to extracellular matrix ligands, type I collagen, fibronectin, laminin and depend on interaction between integrin and extracellular ligand. Our study was designed to investigate the effect of extracellular matrix like fibronectin, laminin, type I collagen on migration of osteoblast. Migration distance and speed of MC3T3-E1 cell on extracellular matrix-coated glass were measured for 24 hours using 0.01% type I collagen, 0.01% fibronectin, 100 microliter/ml laminin. The migration distance and speed of MC3T3-E1 cell was compared using a video-microscopy system. To determine migration speed, cells were viewed with a 4 phase- contrast lens and video recorded. Images were captured using a color CCD camera and saved in 8-bit full-color mode. The migration distance on 0.01% type I collagen or 0.01% fibronectin was longer than that on $100{\mu}l/ml$ laminin-coated glass. The migration speed on fibronectin-coated glass was 68 micrometer/hour which was fastest. The migration speed on type I collagen-coated glass was similar with that on fibronectin-coated glass. The latter two migration speeds were faster than that on no-coated glass. On the other hand, the average migration speed on laminin-coated glass was 37micrometer/hour and not different from that of control group. In conclusion, the extracelluar matrix ligands such as type I collagen and fibronectin seem to play an important role in cell migration. The type I collagen or fibronectin coated scaffold is more effective for migration of osteoblast in tissue engineering process.