• 제목/요약/키워드: Mucosal epithelial cells

검색결과 104건 처리시간 0.033초

Insulin-like growth factor가 소장 점막 세포 증식에 미치는 영향

  • 윤정한
    • 한국영양학회:학술대회논문집
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    • 한국영양학회 1995년도 추계학술대회 초록
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    • pp.11-34
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    • 1995
  • Growth hormone (GH) plays a key role in regulating postnatal growth and can stimulate growth of animals by acting directly on specific receptors on the plasma membrane of tissues or indirectly through stimulating insulin-like growth factor (IGF)-I synthesis and secretion by the liver and other tissues. IGF-I and IGF-Ⅱ are polypeptides with structural similarity with proinsulin that stimulate cell proliferation by endocrine, paracrine and autocrine mechanisms. The initial event in the metabolic action of IGFs on target cells appears to be their binding to specific receptors on the plasma membrane. Current evidence indicates that the mitogenic actions of both IGFs are mediated primarily by binding to the type I IGF receptors, and that IGF action is also mediated by interactions with IGF-binding proteins (IGFBPs). Six distinct IGFBPs have been identified that are characterized by cell-specific interaction, transcriptional and post-translational regulation by many different effectors, and the ability to either potentiate or inhibit IGF actions. Nutritional deficiencies can have their devastating consequence during growth. Although IGF-I is the major mediator of GH's action on somatic growth, nutritional status of an organism is a critical regulator of IGF-I and IGFBPs. Various nutrient deficiencies result in decreased serum IGF-I levels and altered IGFBP levels, but the blood levels of GH are generally unchanged or elevated in malnutrition. Effects of protein, energy, vitamin C and D, and zinc on serum IGF and IGFBP levels and tissue mRNA levels were reviewed in the text. Multiple factors are involved in the regulation of intestinal epithelial cell growth and differentiation. Among these factors the nutritional status of individuals is the most important. The intestinal epithelium is an important site for mitogenic action of the IGFs in vivo, with exogenous IGF-I stimulating mucosal hyperplasia. Therefore, the IGF system appears to provide and important mechanism linking nutrition and the proliferation of intestinal epithelial cells. In order to study the detailed mechanisms by which intestinal mucosa is regulated, we have utilized IEC-6 cells, an intestinal epithelial cell line and Caco-2 cells, a human colon adenocarcinoma cell line. Like intestinal crypt cells analyzed in vivo or freshly isolated intestinal epithelial cells, IEC-6 cells and Caco-2 cells possess abundant quatities of both type Ⅰ and type Ⅱ IGF receptors. Exogenous IGFs stimulate, whereas addition of IGFBP-2 inhibits IEC-6 cell proliferation. To investigate whether endogenously secreted IGFBP-2 inhibit proliferation, IEC-6 cells were transfected with a full-length rat IGFBP-2 cDNA anti-sense expression construct. IEC-6 cells transfected with anti-sense IGFBP-2 protein in medium. These cells grew at a rate faster than the control cells indicating that endogenous IGFBP-2 inhibits proliferation of IEC-6 cells, probably by sequestering IGFs. IEC-6 cells express many characteristics of enterocyte, but do not undergo differentiation. On the other hand, Caco-2 cells undergo a spontaneous enterocyte differentiation. On the other hand, Caco-2 cells undergo a spontaneous enterocyte differentiation after reaching confluency. We have demonstrated that Caco-2 cells produce IGF-Ⅱ, IGFBP-2, IGFBP-3, and an as yet unidentified 31,000 Mr IGFBP, and that both mRNA and peptide secretion of IGFBP-2 and IGFBP-3 increased, but IGFBP-4 mRNA and protein secretion decreased after the cells reached confluency. These changes occurred in parallel to and were coincident with differentiation of the cells, as measured by expression of sucrase-isomaltase. In addition, Caco-2 cell clones forced to overexpress IGFBP-4 by transfection with a rat IGFBP-4 cDNA construct exhibited a significantly slower growth rate under serum-free conditions and had increased expression of sucrase-isomaltase compared with vector control cells. These results indicate that IGFBP-4 inhibits proliferation and stimulates differentiation of Caco-2 cells, probably by inhibiting the mitogenic actions of IGFs.

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어류의 공기호흡 기관 (Modified Organs of Air Breathing Fishes in Korea)

  • 김치홍;박종영
    • 한국어류학회지
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    • 제23권3호
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    • pp.250-254
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    • 2011
  • 한국의 담수어류 중 짱뚱어, 큰볏말뚝말둥어, 말뚝망둥어, 미꾸리, 미꾸라지, 자가사리 등 모두 6종에서 공기로 호흡하기 위해 변형된 부속기관이 알려져 있다. 짱뚱어, 큰볏말뚝말망둥어, 말뚝망둥어, 자가사리 4종은 부족한 산소를 공기로부터 흡입하기 위해 호흡상피 (respiratory epithelium)를 갖는다. 이러한 호흡상피는 풍부한 모세혈관과 2종류의 선세포(점액세포와 곤봉세포-자가사리, 점액세포와 거대세포-짱뚱어) 또는 1종류의 선세포로 구성된 팽대세포 (말뚝망둥어와 큰볏말뚝망둥어)를 갖는다. 특히 거대세포 (swollen cell)는 상피세포의 팽대로 인해 형성된 거미줄 구조 (web-like structure)를 갖고 있다. 또한 짱뚱어의 진피성돌기 (dermal bulge)는 진피성 모세혈관이 매우 풍부하며, 지느러미 등의 부속지를 제외한 피부에 존재한다. 또한 미꾸리와 미꾸라지는 장 상피 (intestinal epithelium)에 모세혈관이 아주 풍부하게 존재한다.

간흡충에 감염된 토끼 및 흰쥐 담관상피의 분비기능 (Secretions of the biliary mucosa in experimental clonorchiasis)

  • 이순형;이종인
    • Parasites, Hosts and Diseases
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    • 제31권1호
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    • pp.13-20
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    • 1993
  • 간흡충에 감염되었을 때 나타나는 조직병리학적 소견의 변화로는 담관 직경이 확장되고 담관벽이 비후되며, 담관 상피층에 선종성 증식과 배세포 화생이 관찰되었다. 치료 후에는 이러한 변화 중에서 화생이 소실되나 선종성 증식은 상당히 완화되어 잔존하고 담관벽의 비후는 지속된다. 이러한 형태학적인 변화는 선종성인 특징이 있어 어떠한 분비기능이 예상되었다. 이 연구에서는 특히 소장의 분비물이 담관 점막층에서 분비되는가를 확인하고자 하였다. 간흡충 피낭유충을 300개씩 8마리의 토끼에 감염시킨 후, 14주에 프라지관텔로 치료하여 구층 후 6개월 및 1년에 간을 적출하고, 파라핀 포매하여 절편을 만들어 분비물에 대하여 면역조직화학법을 시행하였다. Gastrln과 secretin은 정상토기의 간내 담관 및 감염된 담관에서 나타나지 않았다. Serotonin은 비감염 간 내 담관에서는 관찰되지 않았으나, 감염 대조군의 담관상퍼층에서 몇 개의 양성 세포가 관찰되었다. 그러나 치료 후 6개월에는 관찰되지 않았다. 또한 휜쥐에 100개씩 간흡충 피낭유충을 감염시키고 증식된 상피 층에서 소장 미소응모막 효소의 활성을 관찰한 바, alkalinephosphatase의 활성이 감염군에서 대조군과 같은 정도로 관찰되 었으나 sucrose, trehalase, lactate, leucine annnopeptidase의 활성은 나타나지 않았다. 이 결과를 통하여 간흡충 감염시에 증식된 담관상피에 소수의 serotonin 분비세포가 있음을 관찰하였고 다른 소장의 분비기능은 생기지 않음을 확인하였다. 이 serotonin을 포함한 세포는 비만세포로 추정된다.

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Preventive Effects of Spirogyra neglecta and a Polysaccharide Extract against Dextran Sodium Sulfate Induced Colitis in Mice

  • Taya, Sirinya;Kakehashi, Anna;Wongpoomchai, Rawiwan;Gi, Min;Ishii, Naomi;Wanibuchi, Hideki
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권4호
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    • pp.2235-2245
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    • 2016
  • Ulcerative colitis (UC) results from colonic epithelial barrier defects and impaired mucosal immune responses. In this study, we aimed to investigate the modifying effects of a Spirogyra neglecta extract (SNE), a polysaccharide extract (PE) and a chloroform fraction (CF) on dextran sodium sulfate (DSS)-induced colitis in mice and to determine the mechanisms. To induce colitis, ICR mice received 3% DSS in their drinking water for 7 days. Seven days preceding the DSS treatment, oral administration of SNE, PE and CF at doses of 50, 25 and 0.25 mg/kg body weight (low dose), 200, 100 and 1 mg/kg body weight (high dose) and vehicle was started and continued for 14 days. Histologic findings showed that DSS-induced damage of colonic epithelial structure and inflammation was attenuated in mice pre-treated with SNE, PE and CF. Furthermore, SNE and PE significantly protected colonic epithelial cells from DSS-induced cell cycle arrest, while SNE, PE and CF significantly diminished apoptosis. Proteome analysis demonstrated that SNE and PE might ameliorate DSS-induced colitis by inducing antioxidant enzymes, restoring impaired mitochondria function, and regulating inflammatory cytokines, proliferation and apoptosis. These results suggest that SNE and PE could prevent DSS-induced colitis in ICR mice by protection against and/or aiding recovery from damage to the colonic epithelium, reducing ROS and maintaining normal mitochondrial function and apoptosis.

두시하태독법의 Th2 분화 조절을 통한 알레르기 비염 완화 효과 (Reduction of Allergic Rhinitis by Controlling the Th2 Differentiation of Douchi Hataedock)

  • 최준용;안상현;김기봉
    • 대한한방내과학회지
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    • 제38권4호
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    • pp.468-478
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    • 2017
  • Objectives: This study investigated the effects of Douchi Hataedock on Th2-skewed conditions to control allergic rhinitis. Methods: NC/Nga mice were divided into three groups: 10 mice were assigned to the control group (CTRL; no treatment), 10 mice to allergic rhinitis-induced (ARE) without treatment group, and 10 mice to the allergic rhinitis-induced (FGT) after Douchi Hataedock treatment group. The 3-week-old mice of the FGT group were given one 10 mg/kg dose of Douchi Hataedock extract and resensitized to allergic antigens at weeks four, five, and six. Allergic rhinitis was induced primarily in mice nasal cavities for five days after one week of final sensitization. The second induction used the same method one week after the first induction was completed. After one week, the nasal mucosal tissues of each group were observed. Immunohistochemical staining for IL-4, STAT6, CD40, $Fc{\varepsilon}RI$, substance P, MMP-9, $NF-{\kappa}B$ p65, p-IkB, and iNOS in the nasal mucosa was also performed. Results: The FGT group had less respiratory epithelial damage and less mucin secretion in goblet cells than the ARE group and showed a 62% decrease in IL-4, 85% decrease in STAT6, 71% decrease in CD40, 69% decrease in $Fc{\varepsilon}RI$, 43% decrease in substance P, 49% decrease in MMP-9, 43% decrease in NF-kB p65, 38% decrease in p-IkB, and 73% decrease in iNOS compared to the ARE group. Conclusions: Douchi Hataedock lessens inflammation in epithelial and goblet cells and reduces inflammatory mediator secretion in a mouse allergic rhinitis model.

Shigellosis

  • Niyogi Swapan Kumar
    • Journal of Microbiology
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    • 제43권2호
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    • pp.133-143
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    • 2005
  • Shigellosis is a global human health problem. Four species of Shigella i.e. S. dysenteriae, S. flexneri, S. boydii and S. sonnei are able to cause the disease. These species are subdivided into serotypes on the basis of O-specific polysaccharide of the LPS. Shigella dysenteriae type 1 produces severe disease and may be associated with life-threatening complications. The symptoms of shigellosis include diarrhoea and/or dysentery with frequent mucoid bloody stools, abdominal cramps and tenesmus. Shigella spp. cause dysentery by invading the colonic mucosa. Shigella bacteria multiply within colonic epithelial cells, cause cell death and spread laterally to infect and kill adjacent epithelial cells, causing mucosal ulceration, inflammation and bleeding. Transmission usually occurs via contaminated food and water or through person-to-person contact. Laboratory diagnosis is made by culturing the stool samples using selective/differential agar media. Shigella spp. are highly fragile organism and considerable care must be exercised in collecting faecal specimens, transporting them to the laboratories and in using appropriate media for isolation. Antimicrobial agents are the mainstay of therapy of all cases of shigellosis. Due to the global emergence of drug resistance, the choice of antimicrobial agents for treating shigellosis is limited. Although single dose of norfloxacin and ciprofloxacin has been shown to be effective, they are currently less effective against S. dysenteriae type 1 infection. Newer quinolones, cephalosporin derivatives, and azithromycin are the drug of choice. However, fluoroquinolone-resistant S. dysenteriae type 1 infection have been reported. Currently, no vaccines against Shigella infection exist. Both live and subunit parenteral vaccine candidates are under development. Because immunity to Shigella is serotype-specific, the priority is to develop vaccine against S. dysenteriae type 1 and S. flexneri type 2a. Shigella species are important pathogens responsible for diarrhoeal diseases and dysentery occurring all over the world. The morbidity and mortality due to shigellosis are especially high among children in developing countries. A recent review of literature (KotIoff et al.,1999) concluded that, of the estimated 165 million cases of Shigella diarrhoea that occur annually, $99\%$ occur in developing countries, and in developing countries $69\%$ of episodes occur in children under five years of age. Moreover, of the ca.1.1 million deaths attributed to Shigella infections in developing countries, $60\%$ of deaths occur in the under-five age group. Travellers from developed to developing regions and soldiers serving under field conditions are also at an increased risk to develop shigellosis.

Th17 responses and host defense against microorganisms: an overview

  • Van De Veerdonk, Frank L.;Gresnigt, Mark S.;Kullberg, Bart Jan;Van Der Meer, Jos W.M.;Joosten, Leo A.B.;Netea, Mihai G.
    • BMB Reports
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    • 제42권12호
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    • pp.776-787
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    • 2009
  • T helper (Th) 17 cells have recently been described as a third subset of T helper cells, and have provided new insights into the mechanisms that are important in the development of autoimmune diseases and the immune responses that are essential for effective antimicrobial host defense. Both protective and harmful effects of Th17 responses during infection have been described. In general, Th17 responses are critical for mucosal and epithelial host defense against extracellular bacteria and fungi. However, recent studies have reported that Th17 responses can also contribute to viral persistence and chronic inflammation associated with parasitic infection. It has become evident that the type of microorganisms and the setting in which they trigger the Th17 response determines the outcome of the delicate balancethat exists between Th17 induced protection and immunopathogenesis.

산란계에서의 칸디다증 국내 발생 사례 (Candidiasis in layer chickens in Korea)

  • 성환우;권혁무;한정희;모인필
    • 대한수의학회지
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    • 제50권4호
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    • pp.323-326
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    • 2010
  • Candidiasis is a mycosis caused by the mycelial yeast of the Candida genus which is opportunistic pathogen of humans, animals, and birds. Under some conditions such as prolonged antibiotic therapy, overcrowding, and immunosuppression, the opportunistic Candida can cause disease. Chicken candidiasis is sporadically occurred and characterized by unsatisfactory growth, listlessness, roughness of feathers, and death. A case of 23 weeks old layer with history of increased mortality and anemia was submitted to our Lab. At necropsy, the characteristic lesions were observed in the crop and proventriculus. The whitish pseudomembrane, that are peeled easily, was found in the crop. Proventriculus was swollen and the mucosa was covered with hemorrhagic exudate. The histological changes of the affected crop are epithelial hyperplasia, hydropic degeneration, and mycelia formation. Smears made from the necrotic mucosal surfaces of the crop revealed the presence of large number of yeast cells and mycelia. Pure cultures of yeast colonies were obtained from the potato dextrose agar. The yeast cells were identified as Candida albicans by gene sequencing. To our knowledge, this is the first report of candidiasis in chickens with anemia in Korea.

총담관 결찰후 집토끼 담낭상피세포의 미세구조적 변화 (An Ultrastructural Study on the Epithelial Cells of the Rabbit Gallbladder after Common Bile Duct Ligation)

  • 임수재;양남길;안의태;고정식;박경호;김진국
    • Applied Microscopy
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    • 제22권2호
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    • pp.15-29
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    • 1992
  • The gallbladder is known to have the function of the storage and the concentration of the bile produced by the liver. This function is carried out by the removal of water and inorganic electrolytes. Extrahepatic cholestasis or the impairment of excretion of the bile leads to the distension and loss of the function of the gallbladder. The purpose of this study was to examine the ultrastructural characteristics of the normal gallbladder epithelial cells, and their structural changes induced by the ligation of common bile duct of the rabbit. Common bile duct ligation was performed under ether anesthesia. The rabbits were sacrificed on the 1st, 3rd, 5th, 7th and 14th day, respectively after operations. The tissue blocks of the gallbladder were fixed in 2.5% glutaraldehyde-1.5% paraformaldehyde prior to fixation in 1% osmium tetroxide, and embedded in the araldite mixture, and observed with JEM 100 CX-II electron microscope. The results were as follows: 1. The normal gallbladder epithelium of adult rabbit demonstrated two cell types, the ordinary epthelial cell and the dark cell. The dark cells have electron dense cytoplasm, and were found much infrequently, whereas ordinary epthelial cells were found quite numerous. 2. The ordinary epthelial cells of normal gallbladder were provided with the regular microvilli at the free surface and the images of pinocytotic activities in the apical cytoplasm, and exhibit highly convoluted lateral surfaces with elaborated microfolds. These figures of the cells suggest that they are resorptive in functional activity. 3. In the early stages (1st, 3rd, 5th day groups) following the ligation, the apical cytoplasm of some cells is protruding from the free surface and lost their microvilli. Numerous mucous granules filled in the apical and supranuclear cytoplasm compactly. 4. In the late stages (7th, 14th day groups) following the ligation, many light cells containing mumerous mucous granules are seen, between the ordinary epthelial cells. Mucous granules are fused each other, and are discharged into the lumen from the apical cytoplasm. The lateral membranes are straight or undulating without any interdigitations. From the above results, it was concluded that in the cholestasis induced by the common bile duct ligation, there is a tendency for the mucosal epithelium of the rabbit gallbladder to have secretory rather than an absorptive function.

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햄스터 구강암 발생 과정에서 Heat Shock Protein에 관한 면역조직화학적 연구 (A IMMUNOHISTOCHEMICAL STUDY ON HEAT SHOCK PROTEIN IN ORAL CARCINOGENESIS IN HAMSTER)

  • 최규환;이동근;김은철;정창주
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제23권2호
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    • pp.124-136
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    • 2001
  • Heat shock protein (HSP) expression is unregulated in tumor cells and, HSP expression is likely marker of the malignant potential of oral epithelial lesion. Furthermore, the 70kDa HSP is implicated in the degree of tumor differentiation, the rate of tumor proliferation and the magnitude of the anti-tumor Immune response. Accordingly, the distribution and intensity of HSP70 and HSP47 expression was assessed in the DMBA induced oral carcinogenesis in hamster. Golden Syrian hamsters which were 3 months-age and $90{\sim}120g$ were collected. 9,10-dimethyl -1,2-benzanthracene (DMBA) in a 0.5% solution in mineral oil was painted on the buccal pouch mucosa 3 times per week in the study group. In each control and experimental groups of 6, 8, 10, 12, 14, 16, 18, 20 weeks, specimen were sectioned for immunohistochemical study with anti-HSP47 and anti-HSP70 antibody. The following results were obtained. 1. HSP47 positive cells were race or negative of normal oral mucosa, increased mildly in basal and suprabasal basal layer, and spinous cell layer after experimental 6 weeks (dysplastic or CIS stage). In CIS stage, HSP47 expression is prominent in dysplastic free or normal adjacent epithelium. 2. HSP47 positive cells in connective tissue were mainly inflammatory cells, which is gradually increased from control to precancerous and cancer stage. But HSP47 positive cells after 14 weeks were decreased, especially normal and cancer adjacent epithelium. 3. The positive staining cells of HSP70 in control, dysplastic, and CIS stage were not seen. But they were mild findings in basal layer and moderate findings in spinous layer after experimental 14 weeks (cancer stage). 4. HSP70 positive cells were increased in precancerous and cancer stage than control group in connective tissue. After experimental 16 weeks, we could not find the HSP expression in cancer cells according to cancer differentiation or cancer stage. It is concluded that HSP70 or HSP47 expression is not a definitive marker of oral malignancy or malignant potential. However, with further development, HSP immunoreactivity may be valuable as an adjunct to conventional histology for assessing the malignant potential of oral mucosal lesions.

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