• Title/Summary/Keyword: Biological tissue

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The Tissue Types of Stroma in Some Species of Hypoxylon (Hypoxylon속 자낭자좌 조직의 형태 연구)

  • Lee, Yang-Soo
    • Applied Microscopy
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    • v.27 no.4
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    • pp.453-460
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    • 1997
  • The tissue types of stromata were observed intensively in four species of Hypoxylon under a scanning electron microscope (SEM). These stromata were sectioned with a freezing fracture method for observation. Several tissue types were recognized and stable in each species. This study presents the most intensive observation of tissue types of each layer of stromata. It will be useful for taxonomic criteria for the species level. However, the tissue types can not be major taxonomical criteria for the genus Hypoxylon.

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Agonist (P1) Antibody Converts Stem Cells into Migrating Beta-Like Cells in Pancreatic Islets

  • Eun Ji Lee;Seung-Ho Baek;Chi Hun Song;Yong Hwan Choi;Kyung Ho Han
    • Journal of Microbiology and Biotechnology
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    • v.32 no.12
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    • pp.1615-1621
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    • 2022
  • Tissue regeneration is the ultimate treatment for many degenerative diseases, however, repair and regeneration of damaged organs or tissues remains a challenge. Previously, we showed that B1 Ab and H3 Ab induce stem cells to differentiate into microglia and brown adipocyte-like cells, while trafficking to the brain and heart, respectively. Here, we present data showing that another selected agonist antibody, P1 antibody, induces the migration of cells to the pancreatic islets and differentiates human stem cells into beta-like cells. Interestingly, our results suggest the purified P1 Ab induces beta-like cells from fresh, human CD34+ hematopoietic stem cells and mouse bone marrow. In addition, stem cells with P1 Ab bound to expressed periostin (POSTN), an extracellular matrix protein that regulates tissue remodeling, selectively migrate to mouse pancreatic islets. Thus, these results confirm that our in vivo selection system can be used to identify antibodies from our library which are capable of inducing stem cell differentiation and cell migration to select tissues for the purpose of regenerating and remodeling damaged organ systems.

Extracellular Matrix of Fresh and Cryopreserved Porcine Aortic Tissues

  • Shon, Yun-Hee
    • BMB Reports
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    • v.30 no.2
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    • pp.106-112
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    • 1997
  • The effect of cryopreservation on extracellular matrix was studied with the ultimate objective of permiting a prediction of the tendency of aorta conduit tissue to calcify following transplantation. Cryopreserved and fresh porcine aorta conduit tissues were extracted using guanidine-hydrochloride (Gdn-HCl) followed by sequential digestion of the tissues with collagenase, elastase, and papain. Glycosaminoglycans (GAGs) of the proteoglycans (PGs) were isolated and quantitated. Gdn-HCl extracted about 61% and 62% of the total GAG (proteoqlycan) material from cryopreserved and fresh tissues, respectively. Collagenasesolubilized proteoglycans from Gdn-HCl extracted tissue represented 20% and 13%, respectively, of the total GAGs present in cryopreserved and fresh tissues. Subsequent elastase hydrolysis of collagenase-digested tissue released about 11% of total GAGs from cryopreserved tissue and 16% from fresh tissue. The remaining 8%, from cryopreserved tissue, and 9%, from fresh tissue, of the total GAGs were obtained after using a papain hydrolysis. There was essentially no difference between fresh and cryopreserved tissues in the relative distribution of proteoglycans in the extracts and digestions except in the initial digestion step where more proteoglycans were obtained from collagenase solubilization of cryopreserved tissue than fresh tissue (p<0.05). The histologic status of the fresh and cryopreserved porcine aortic conduit did not differ markedly. The normal tissue architecture was not affected markedly by the cryopreservation procedure as neither alteration of elastic structure, fibrous proteins nor alteration of nuclear distribution or smooth muscle cell morphology was detected. Quantitative tissue mineral studies revealed that the mean calcium content of the cryopreserved aorta conduit tissue $(165{\pm}3\;{\mu}g/g\;wet\;tissue)$ was higher than that of the fresh tissue $(105{\pm}4\;{\mu}g/g\;wet\;tissue)$ $(p<0.05)$. The mean phosphorus content was $703{\pm}35\;{\mu}g$ wet tissue from cryopreserved tissue and $720{\pm}26\;{\mu}g$ wet tissue from fresh tissue. The study indicates that there is no significant alteration in the distribution of PGs in properly cryopreserved tissue, but the total calcium level appears to be increased in tissue cryopreserved by the cryopreservation process used in this study.

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Fabrication of Piezoelectric Cantilever with Microcone Tip for Sensing Local Stiffness of Biological Tissue (생체 조직의 국소 강도 측정을 위한 마이크로 콘 팁을 가진 압전 캔틸레버 제작)

  • Roh, Hee Chang;Yang, Dasom;Ryu, WonHyoung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.11
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    • pp.743-748
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    • 2017
  • For diseases that are difficult to detect by conventional imaging techniques, the development of a diagnostic method that allows sensors to be inserted into the human body to aid the diagnosis of local spots of the target tissue, is highly desirable. In particular, it is extremely difficult to determine whether vulnerable plaque can later develop into atherosclerosis using only imaging techniques. However, vulnerable plaques are expected to have slightly different mechanical properties than healthy tissue. In this study, we aim to develop a piezoelectric cantilever-type sensor that can be inserted into the human body and can detect the local mechanical properties of the target tissue. A piezoelectric polymer composite based on $BaTiO_3$ nanoparticles was optimized for fabrication of a piezoelectric cantilever. Next, a micro-cone tip was fabricated at the end of the piezoelectric cantilever by thermal drawing. Finally, stiffness of biological tissue samples was measured with the piezoelectric cantilever sensor for verifying its functionality.

The Effect of Leonurus sibiricus on Uterine Activity (익모초(Leonurus sibiricus)가 자궁운동에 미치는 영향)

  • Pak, S.C.;Na, H.M.;Bai, Y.H.;Cho, C.;Na, C.S.;Kim, J.S.;Wilson Jr., L.
    • Korean Journal of Animal Reproduction
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    • v.19 no.4
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    • pp.245-250
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    • 1996
  • This study was undertaken to illustrate the uterotonic effect of Leonurus sibiricus. It was dissolved in sterile water and several different dosages were administered both in vitro and in vivo study. Rat uterine tissue for in vitro bioassay was obtained from estrous rat. From the low to high dosages of Leonurus sibiricus were tried and each uterine contraction was recorded and integrated. Anesthetized estrous rat for in vivo study was cannulated into the jugular vein for infusion of the compound. Another cannula with a balloon tipped and water filled was inserted into the uterus to measure uterine activity. While the uterine tissue did not respond to low dosage of compound, high dosage of compound stimulated the tissue to contract less than 1 minute with low amplitude. In vivo rat uterus showed a certain, consistent pattern of contractions which was initial relaxation and followed by prolonged and increased amplitude of contractions. It also caused a short breathing stop which might be due to acute acidosis.

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