• Title/Summary/Keyword: Tissue remodeling

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Distal Aortic Remodeling after Type A Dissection Repair: An Ongoing Mirage

  • Rathore, Kaushalendra Singh
    • Journal of Chest Surgery
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    • v.54 no.6
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    • pp.439-448
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    • 2021
  • Remodeling is a commonly encountered term in the field of cardiothoracic surgery that is often used to describe various pathophysiological changes in the dimension, structure, and function of various cardiac chambers, including the aorta. Stanford type A or DeBakey type 1 aortic dissection (TAAD) is a perplexing pathologic condition that can present surgical teams with the need to navigate a maze of complex decision-making. Ascending or hemi-arch replacement leaves behind a significant amount of distal diseased aortic tissue, which might have a persistent false lumen or primary or secondary intimal tears (or communications between lumina), which can lead to dilatation of the aortic arch. Unfavorable aortic remodeling is a major cause of distal aortic deterioration after the index surgery. Cardiac surgeons are aware of post-surgical cardiac chamber remodeling, but the concept of distal aortic remodeling is still idealized. The contemporary literature from established aortic centers supports aggressive management of the residual aortic pathology during the index surgery, and with continuing technical advancements, endovascular stenting options are readily available for patients with TAAD or for complicated type B aortic dissection cases. This review discusses the pathophysiology and treatment options for favorable distal aortic remodeling, as well as its impact on mid- to long-term outcomes following TAAD repair.

Bone Cell Response to Neurotransmitters and Mechanical Loading (신경전달물질 및 물리적 자극에 대한 뼈 세포의 반응)

  • Kwag, J.H.;Kim, B.G.;Kim, K.H.;Kim, C.H.
    • Journal of Biomedical Engineering Research
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    • v.30 no.1
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    • pp.89-93
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    • 2009
  • Bone remodeling is a continuous process of skeletal renewal during which bone formation is tightly coupled to bone resorption. Mechanical loading is an important regulator of bone formation and resorption. In recent studies, neurotransmitters such as vasoactive intestinal peptide (VIP) were found to be present inside bone tissue and have been suggested to potentially regulate bone remodeling. In this study, our objective was to use a pre-established in vitro oscillatory fluid flow-induced shear stress mechanical loading system to quantify the effect of VIP on bone resorptive activity and investigate its combined effect with mechanical loading. VIP decreased osteoclastogenesis significantly decreased RANKL/OPG mRNA ration by approximately 90%. Combined VIP and mechanical loading further decreased RANKL/OPG ratio to approximately 95%. These results suggest that VIP present in bone tissue may synergistically act with mechanical loading to regulate bone remodeling via suppression of bone resorptive activities.

Macrophagal Polykaryocytes in Inflammation, Tumor Growth, and Tissue Remodeling

  • Schepetkin, Igor-A.;Kiran, Kondaragil-R.;Kwon, Byoung-S.
    • Journal of Microbiology and Biotechnology
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    • v.11 no.5
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    • pp.727-738
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    • 2001
  • Macrophagal polykaryocytes (MPs) are terminally differentiated multinuclear macrophage cells responsible for remodeling and resorption of bone, foreign body, and tissue deposition in inflammation. MPs are encountered only in bone and cartilagenous tissues, in which they are referred to as osteoclasts, odontoclasts, in which they are referred to as osteoclasts, odontoclasts, and septoclasts. Depending on the disease, the MPs differentiate into many morphological variants that include foreign-body giant cells, Langhans-type cells, and Touton-type cells. Morphological heterogeneity of MPs could Touton-type cells. Morphological heterogeneity of MPs could reflect the giant cell formation from phenotypically different marophage precursors by the process of fusion. At present, many cytokines, adhesion/fusion molecules, and other factors of the microenvironment have been discovered that influence the multinucleation process. Many evidences suggest that conditions in giant cell fibrohistiocytomas, which facilitate MP formation, are similar to the inflammation site of granulomatosis. MPs in the giant cell tumors and granulomatosis foci are formed in response to the factors secreted by mesenchymal cells. It is proposed that one of the first steps in vertebrate evolution could be the organization of skeleton remodeling, in which osteoclasts play a major role. In this step, the same mechanism of regulations served as a basis for the development of both osteoclast and inflammatory forms of MPs.

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Inhibitory Effect of Standardized Curcuma xanthorrhiza Supercritical Extract on LPS-Induced Periodontitis in Rats

  • Kook, Kyo Eun;Kim, Changhee;Kang, Wonku;Hwang, Jae-Kwan
    • Journal of Microbiology and Biotechnology
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    • v.28 no.10
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    • pp.1614-1625
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    • 2018
  • Periodontitis, which is a severe inflammatory disease caused by endotoxins secreted from oral pathogens, destructs gingival tissue and alveolar bone. Curcuma xanthorrhiza, commonly called Java turmeric, has been shown to possess anti-bacterial and anti-inflammatory activities. The present study evaluated the inhibitory effect of C. xanthorrhiza supercritical extract (CXS) standardized with xanthorrhizol on lipopolysaccharide (LPS)-induced periodontitis in an animal model. LPS was topically injected into the periodontium of Sprague-Dawley rats to induce periodontitis and CXS (30 and $100mg{\cdot}kg^{-1}{\cdot}day^{-1}$) was orally administered after day 12. Histologically, CXS inhibited the collapse of gingival tissue by preventing cell infiltration. CXS significantly downregulated the expression of matrix metalloproteases (MMPs) and inflammation-related biomarkers, such as nuclear factor-kappa B ($NF-{\kappa}B$) and interleukin-1 beta ($IL-1{\beta}$) in gingival tissue. CXS also improved bone remodeling by downregulating osteoclastic transcription factors, such as nuclear factor of activated T-cells c1 (NFATc1), tartrate-resistant acid phosphatase (TRAP), and cathepsin K. In addition, CXS upregulated osteoblast differentiation-related markers, alkaline phosphate (ALP) and collagen type I alpha (COLA1). Thus, CXS can ameliorate periodontitis by inhibiting inflammation and improving bone remodeling.

Study on Guidelines for Using Therapeutic Modalities According to Injury Phases of Soft Tissue (치료적 방법을 연부조직 손상단계에 따라 사용하기 위한 지침에 관한 연구)

  • Kwon Won-An;Kim Sik_hyun;Jun Kyong-hee
    • The Journal of Korean Physical Therapy
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    • v.12 no.3
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    • pp.497-507
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    • 2000
  • This study was performed to understanding on guidelines for using therapeutic modalities according to injury phases of soft tissue. Clinical decisions on how and when therapeutic modalities may be used should be based on recognition of signs and symptoms. as well as some awareness of the time frames associated with the various phases of the Healing process. The physical therapist must have a sound understanding of that process in terms of the sequence of the various process of healing stage. The results of this study are as follows: 1. Once an acute injury has occured, the healing process consists of the imflammatory response phase, the fibroblastic-repair phase, and the maturation-remodeling phase and can impede by various pathologic factors. 2. Modality use in the initial acute injury phase and the inflammatory response phase should be directed toward limiting the amount of swelling and reducing pain. 3. Modality use in the Fibroblastic repair phase may be change from cold to heat. The purpose of heat is to increase circulation to the injured area to promote healing. 4. During the Maturation-Remodeling phase, some type of heating modalities, ultrasound, or short wave and microwave diathermy should be used to increase circulation to the deeper tissue. In this phases, physical therapists must control training and conditioning habits to allow the injury to heal sufficiently.

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Expression of Plasminogen Activators in Uterine Epithelial Cells of Pre-ovulatory Phase in Pigs (돼지의 배란 전 자궁내막 상피세포 내 Plasminogen Activators의 발현)

  • HwangBo, Yong;Lee, Sang-Hee;Cha, Hye-Jin;Song, Eun-Ji;Lee, Seung-Tae;Lee, Eun-Song;Cheong, Hee-Tae;Yang, Boo-Keun;Park, Choon-Keun
    • Journal of Embryo Transfer
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    • v.28 no.3
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    • pp.257-263
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    • 2013
  • The endometrium undergoes a cyclic growth and tissue remodeling as changes of epithelial cells, and plasminogen activators (PAs) are related to endometrium tissue remodeling. This study was to evulate expression of urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) in porcine uterine epithelial cells. In results, the uPA and tPA were expressed in uterine tissue, epithelium and secretory glands in porcine endometrial cell. In addition, the uPA and tPA were expressed in cultured epithelial cells, and it were mainly expressed in cytoplasm. In porcine uterine tissue and epithelial cells, uPA activity was higher than activity in tPA. In PAs mRNA expression levels, uPA mRNA level was significantly higher than tPA mRNA level (P<0.05). The fluorescence intensity of uPA protein was also higher than fluorescence intensity of tPA protein, and uPA protein expression was significantly higher than in tPA protein expression (P<0.05). Therefore, we suggest that a physiological function in porcine uterine epithelial cells should be more influenced by uPA than in tPA during pre-ovulatory phase.

Neural circuit remodeling and structural plasticity in the cortex during chronic pain

  • Kim, Woojin;Kim, Sun Kwang
    • The Korean Journal of Physiology and Pharmacology
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    • v.20 no.1
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    • pp.1-8
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    • 2016
  • Damage in the periphery or spinal cord induces maladaptive plastic changes along the somatosensory nervous system from the periphery to the cortex, often leading to chronic pain. Although the role of neural circuit remodeling and structural synaptic plasticity in the 'pain matrix' cortices in chronic pain has been thought as a secondary epiphenomenon to altered nociceptive signaling in the spinal cord, progress in whole brain imaging studies on human patients and animal models has suggested a possibility that plastic changes in cortical neural circuits may actively contribute to chronic pain symptoms. Furthermore, recent development in two-photon microscopy and fluorescence labeling techniques have enabled us to longitudinally trace the structural and functional changes in local circuits, single neurons and even individual synapses in the brain of living animals. These technical advances has started to reveal that cortical structural remodeling following tissue or nerve damage could rapidly occur within days, which are temporally correlated with functional plasticity of cortical circuits as well as the development and maintenance of chronic pain behavior, thereby modifying the previous concept that it takes much longer periods (e.g. months or years). In this review, we discuss the relation of neural circuit plasticity in the 'pain matrix' cortices, such as the anterior cingulate cortex, prefrontal cortex and primary somatosensory cortex, with chronic pain. We also introduce how to apply long-term in vivo two-photon imaging approaches for the study of pathophysiological mechanisms of chronic pain.

Simvastatin as a Modulator of Tissue Remodeling through Inhibition of Matrix Metalloproteinase (MMP) Release from Human Lung Fibroblasts

  • Ra, Ji-Eun;Lee, Ji-Kyoung;Kim, Hui-Jung
    • Tuberculosis and Respiratory Diseases
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    • v.71 no.3
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    • pp.172-179
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    • 2011
  • Background: Statins can regulate the production of pro-inflammatory cytokines and inhibit MMP production or activation in a variety of types of cells. This study evaluated whether statins would inhibit MMP release from human lung fibroblasts, which play a major role in remodeling processes. Methods: This study, using an in-vitro model (three-dimensional collagen gel contraction system), evaluated the effect of cytokines (tumor necrosis factor-${\alpha}$, TNF-a and interleukin-$1{\beta}$, IL-1b) on the MMP release and MMP activation from human lung fibroblasts. Collagen degradation induced by cytokines and neutrophil elastase (NE) was evaluated by quantifying hydroxyproline. Results: In three-dimensional collagen gel cultures (3D cultures) where cytokines (TNF-a and IL-1b) can induce the production of MMPs by fibroblasts, it was found that simvastatin inhibited MMP release. In 3D cultures, cytokines together with NE induced collagen degradation and can lead to activation of the MMP, which was inhibited by simvastatin. Conclusion: Simvastatin may play a role in regulating human lung fibroblast functions in repair and remodeling processes by inhibiting MMP release and the conversion from the latent to the active form of MMP.

Molecular Signatures of Sinus Node Dysfunction Induce Structural Remodeling in the Right Atrial Tissue

  • Roh, Seung-Young;Kim, Ji Yeon;Cha, Hyo Kyeong;Lim, Hye Young;Park, Youngran;Lee, Kwang-No;Shim, Jaemin;Choi, Jong-Il;Kim, Young-Hoon;Son, Gi Hoon
    • Molecules and Cells
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    • v.43 no.4
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    • pp.408-418
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    • 2020
  • The sinus node (SN) is located at the apex of the cardiac conduction system, and SN dysfunction (SND)-characterized by electrical remodeling-is generally attributed to idiopathic fibrosis or ischemic injuries in the SN. SND is associated with increased risk of cardiovascular disorders, including syncope, heart failure, and atrial arrhythmias, particularly atrial fibrillation. One of the histological SND hallmarks is degenerative atrial remodeling that is associated with conduction abnormalities and increased right atrial refractoriness. Although SND is frequently accompanied by increased fibrosis in the right atrium (RA), its molecular basis still remains elusive. Therefore, we investigated whether SND can induce significant molecular changes that account for the structural remodeling of RA. Towards this, we employed a rabbit model of experimental SND, and then compared the genome-wide RNA expression profiles in RA between SND-induced rabbits and sham-operated controls to identify the differentially expressed transcripts. The accompanying gene enrichment analysis revealed extensive pro-fibrotic changes within 7 days after the SN ablation, including activation of transforming growth factor-β (TGF-β) signaling and alterations in the levels of extracellular matrix components and their regulators. Importantly, our findings suggest that periostin, a matricellular factor that regulates the development of cardiac tissue, might play a key role in mediating TGF-β-signaling-induced aberrant atrial remodeling. In conclusion, the present study provides valuable information regarding the molecular signatures underlying SND-induced atrial remodeling, and indicates that periostin can be potentially used in the diagnosis of fibroproliferative cardiac dysfunctions.