• Title/Summary/Keyword: Tissue characterization

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Mouse Cre-LoxP system: general principles to determine tissue-specific roles of target genes

  • Kim, Hyeonhui;Kim, Minki;Im, Sun-Kyoung;Fang, Sungsoon
    • Laboraroty Animal Research
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    • v.34 no.4
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    • pp.147-159
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    • 2018
  • Genetically engineered mouse models are commonly preferred for studying the human disease due to genetic and pathophysiological similarities between mice and humans. In particular, Cre-loxP system is widely used as an integral experimental tool for generating the conditional. This system has enabled researchers to investigate genes of interest in a tissue/cell (spatial control) and/or time (temporal control) specific manner. A various tissue-specific Cre-driver mouse lines have been generated to date, and new Cre lines are still being developed. This review provides a brief overview of Cre-loxP system and a few commonly used promoters for expression of tissue-specific Cre recombinase. Also, we finally introduce some available links to the Web sites that provides detailed information about Cre mouse lines including their characterization.

Changing Role of Nuclear Medicine for the Evaluation of Focal Hepatic Tumors: From Lesion Detection to Tissue Characterization (국소 간 종양의 조직적 특성을 평가하는데 있어 최근 핵의학의 역할)

  • Kim, Chun-Ki;Yu, Mi-Jin
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.3
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    • pp.211-224
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    • 1998
  • The role of scintigraphic imaging has moved from the detection of lesions to the tissue-specific characterization of lesions over the past 2 decades. Major advances in nuclear medicine imaging include: 1) positron imaging, 2) improved instrumentation, such as the use of multidetector (dual or triple head) gamma cameras for single photon emission computed tomography, and 3) development of numerous new radiopharmaceuticals for positron or single photon imaging (labeled glucose analogue, amino acids, fatty acids, hormones, drugs, receptor ligands, monoclonal antibodies, etc). These advances have resulted in a significantly improved efficacy of radionuclide techniques for the evaluation of various tumors, including those within the liver. The current role of nuclear medicine in the evaluation of focal hepatic tumors is reviewed in this article with an emphasis on the clinical applications of various tracer studies and imaging findings.

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Functional Characterization of ABCB4 Mutations Found in Low Phospholipid-Associated Cholelithiasis (LPAC)

  • Kim, Tae Hee;Park, Hyo Jin;Choi, Ji Ha
    • The Korean Journal of Physiology and Pharmacology
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    • v.17 no.6
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    • pp.525-530
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    • 2013
  • Multidrug resistance 3 (MDR3) is expressed on the canalicular membrane of the hepatocytes and plays an important role in protecting the liver from bile acids. Altered ABCB4 gene expression can lead to a rare hepatic disease, low phospholipid-associated cholelithiasis (LPAC). In this study, we characterized 3 ABCB4 mutations in LPAC patients using various in vitro assay systems. We first measured the ability of each mutant to transport paclitaxel and then the mechanisms by which these mutations might change MDR3 transport activity were determined using immunoblotting, cell surface protein biotinylation, and immunofluorescence. Through a membrane vesicular transport assay, we observed that the uptake of paclitaxel was significantly reduced in membrane vesicles expressing 2 ABCB4 mutations, F165I and S320F. Both mutants showed significantly decreased total and cell surface MDR3 expression. These data suggest two missense mutations of ABCB4 may alter function of MDR3 and ultimately can be determined as LPAC-causing mutations.

Cloning and characterization of a cDNA encoding a paired box protein, PAX7, from black sea bream, Acanthopagrus schlegelii

  • Choi, Jae Hoon;Han, Dan Hee;Gong, Seung Pyo
    • Journal of Animal Reproduction and Biotechnology
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    • v.36 no.4
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    • pp.314-322
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    • 2021
  • Paired box protein, PAX7, is a key molecule for the specification, maintenance and skeletal muscle regeneration of muscle satellite cells. In this study, we identified and characterized the cDNA and amino acid sequences of PAX7 from black sea bream (Acanthopagrus schlegelii) via molecular cloning and sequence analysis. A. schlegelii PAX7 cDNA was comprised of 1,524 bp encoding 507 amino acids and multiple sequence alignment analysis of the translated amino acids showed that it contained three domains including paired DNA-binding domain, homeobox domain and OAR domain which were well conserved across various animal species investigated. Pairwise Sequence Alignment indicated that A. schlegelii PAX7 had the same amino acid sequences with that of yellowfin seabream (A. latus) and 99.8% identity and similarity with that of gilt-head bream (Sparus aurata). Molecular phylogenetic analysis confirmed that A. schlegelii PAX7 formed a monophyletic group with those of teleost and most closely related with those of the fish that belong to Sparidae family including A. latus and S. aurata. In the investigation of its tissue specific mRNA expression, the expression was specifically identified in skeletal muscle tissue and a weak expression was also shown in gonad tissue. The cultured cells derived from skeletal muscle tissues expressed PAX7 mRNA at early passage but the expression was not observed after several times of subculture.

Polymer brush: a promising grafting approach to scaffolds for tissue engineering

  • Kim, Woonjung;Jung, Jongjin
    • BMB Reports
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    • v.49 no.12
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    • pp.655-661
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    • 2016
  • Polymer brush is a soft material unit tethered covalently on the surface of scaffolds. It can induce functional and structural modification of a substrate's properties. Such surface coating approach has attracted special attentions in the fields of stem cell biology, tissue engineering, and regenerative medicine due to facile fabrication, usability of various polymers, extracellular matrix (ECM)-like structural features, and in vivo stability. Here, we summarized polymer brush-based grafting approaches comparing self-assembled monolayer (SAM)-based coating method, in addition to physico-chemical characterization techniques for surfaces such as wettability, stiffness/elasticity, roughness, and chemical composition that can affect cell adhesion, differentiation, and proliferation. We also reviewed recent advancements in cell biological applications of polymer brushes by focusing on stem cell differentiation and 3D supports/implants for tissue formation. Understanding cell behaviors on polymer brushes in the scale of nanometer length can contribute to systematic understandings of cellular responses at the interface of polymers and scaffolds and their simultaneous effects on cell behaviors for promising platform designs.

Characterization of Pectate Lyase Produced by Erwinia rhapontici During Growth in Host Plant Tissue (Erwinia rhapontici가 기주식물 조직에서 생산한 Pectate Lyase의 특성)

  • 최재을
    • Korean Journal Plant Pathology
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    • v.10 no.3
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    • pp.163-168
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    • 1994
  • Erwinia rhapontici causes soft-rot disease in a number of plants such as rhubarb, onion, hyacinth and garlic. Pectate lyase (Pel) depolymerizes pectin and other polygalacturonates, which is though to play a role in bacterial invasion of plants. Pel activity was not detected in E. rhapontici cultured in a minimal salts medium containing glycerol, polygalacturonate, or citrus pectin as a carbon source. However, when sterilized potato tuber and Chinese cabbage slices were added to minimal salts polygalacturonate (0.5%) medium, E. rhapontici produced pectate lyase enzyme. Also Pel activity was consistently detected from macerated potato tubers, Chinese cabbage leaves, lettuce leaves and celery petioles tissue. Pel in the extract of macerated Chinese cabbage caused by E. rhapontici strain 1, resulted in electrolyte loss, tissue maceration and cell death of potato tuber tissue. These results indicate that E. rhapontici produces pectate lyase only in the presence of non-diffusible plant components, and that this enzyme probably contributes to its pathogenicity.

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Characterization of HA/PCL composite scaffolds fabricated by layer manufacturing technology

  • Kim, Seung-Eon;Hyun, Yong-Taek;Yun, Hui-Suk;Yoon, Taek-Rim;Heo, Su-Jin;Shin, Jung-Woog
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1409-1410
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    • 2008
  • Layer manufacturing technology has been recently spotlighted as a promising candidate to fabricate porous scaffolds for tissue engineering, because it can provide three dimensional interconnectivity and different pore structures and on-demand scaffold design. This study aims to fabricate HA/PCL composite scaffolds for bone tissue engineering by a layer manufacturing technology, paste extruding deposition, and to characterize in vitro and in vivo biocompatibilities of the scaffolds. This study discusses the mechnical properties, proliferation and differentiation of osteogenic cells, and tissue in-growth and bone regeneration behavior using animal models.

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Application of DSP for Processing the Reflected Ultrasonic Signal in Biological Tissue (생체조직내의 초음파 반사신호 처리를 위한 DSP 응용)

  • Lee, S.M.;Min, H.K.;Choi, H.H.;Hong, S.H.
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.720-722
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    • 1988
  • The Diagnostic applications of Ultrasound are developed in many ways. In this paper, We measure the attenuation coeffient of biological tissue using DSP. This method is useful in tissue characterization with real time. In the future, We expect that this method coupling with the ultrasonic temperature dependence of biological tissue also is applied to hyperthermia.

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A Basic Study on the Variation of Temperature Characteristics for Attenuation Coefficient and Sound Velocity in Biological Tissues

  • Park, Heung-Ho
    • Journal of Biomedical Engineering Research
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    • v.14 no.3
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    • pp.273-282
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    • 1993
  • This study is concerned with the temperature dependence characteristics of ultrasound parameters in biological tissues, which are basic on the noninvasive deep body temperature estimation. Used parameters are ultrasonic attenuation coefficient and sound velocity In order to accomplishment our purpose, several signal processing methods were used. Attenua4iorl coefficient was estimated by spectral difference method and sound velocity was estimated by P-P method. And we also examined these methods through a series of IN VITRO experi mentis that used tissue-mimicking phantom samples and biological tissue samples. In order to imitate the biological soft tissue two kinds of phantom samples are used, one is agar phantom sample which is composed of agar, graphite, N-propyl alcohol and distilled water, and the other is fat phantom sample which is composed of pure animal fat. And the ultrasound transmission mode and reflection mode experiments are performed on the pig's spleen, kidney and fat. As a result, it is found that the temperature characteristics are uniform in case of phan- tom samples but not in biological tissues because of complicate wave propagation within them. Consequently, the possibility of temperature measurement using ultrasound on biological tissue is confirmed and its results may contribute to the establishment of reference values of internal temperature measurement of biological tissues.

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ISOLATION OF HUMAN ALVEOLAR BONE-DERIVED CELLS AND IN VITRO AMPLIFICATION FOR TISSUE ENGINEERING (조직공학용 사람 치조골세포의 인공증식)

  • Choi, Byung-Ho;Park, Jin-Hyoung;Huh, Jin-Young;Yoo, Jae-Ha
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.27 no.5
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    • pp.453-456
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    • 2001
  • Background: Autogenous alveolar bone cell transplantation may be suitable for tissue engineering for alveolar bone reconstruction. This study aimed to isolate human alveolar bone-derived cells (HABDCs) and to evaluate the ability of collagen gels to support HABDC proliferation and differentiation for human alveolar bone tissue engineering applications. Method: Cultures of primary HABDCs were established from alveolar bone chips obtained from 10 persons undergoing tooth extraction. These cells were expanded in vitro until passage 3 and used for the in vitro characterization of HABDCs and the in vitro analysis of collagen gels for alveolar bone tissue engineering. Results: Of the 10 attempts made to obtain HABDC cultures, eight were successful. HABDCs expressed the osteoblastic phenotype characterized by alkaline phosphatase activity, osteocalcin expression and the mineralization of the extracellular matrix in vitro. When seeded on collagen gels, HABDCs penetrated into the collagen gel matrices and proliferated inside the gels. Significantly, when HABDCs were embedded into the gels, collagen fibers and mineralization were produced within the gels. Conclusion: This study demonstrates the feasibility of using cultured HABDCs and collagen gels for human alveolar bone tissue engineering applications.

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