(The) changes in the Kidney of rats induced by homologous placental tissue as observed with the light and electron microscope

의학과/박사[한글] [영문]Toxemia of pregnancy, a disorder of the human characterized by hypertension, proteinuria, edema and in certain cases, convulsion an coma, is a peculiar symptom complex with unknown etiology and mechanism. McKay and his associates (1953), reported that intravascular fibrin deposition in arterioles and capillaries, throughout the body is responsible for the necrosis and hemorrhage seen in eclampsia and speculated that the mechanism behind the fibrin deposition is similar to that in the generalized Schwartzman reaction. Certainly, lesions of the brain, pituitary, liver and kindney may occur in toxemia of pregnancy, but it is generally accepted that the lesions of the kidney constitute the specific pathologic disturbance and many excellent studies have been carried out dealing with the renal lesions in the toxemia of pregnancy (Bell, 1932; Baird & Dunn, 1933; Sheehan, 1950; Govan, 1954; Dieckmann, 1957; and Spargo, et al. 1959). In 1947, a condition closely simulating toxemia of pregnancy with albuminuria, hypertension and edema was produced in rats by sensitizing them against placenta protein before they became pregnant and the histopathologic changes of the kidney corresponded closely to the early lesions in the human toxemia of pregnancy (Lin, 1947). With the improvement of biopsy technique, fresh renal tissue became available and renal lesions at various stages of toxemia were observed with light and electron microscope by many authors. Certain lesions were felt to be diagnostic (Dieckman, et al., 1957; Hopper, et al., 1961; Altchek, 1961; Mautner, 1962; Pirani, et al., 1963; Altchek, 1964; Altchek, et al., 1968). In 1967, Irino and his associates induced similar renal lesions to those of human toxemia by repeated intraperitoneal injections of homologous placenta in rats and concluded that the lesions were closely resembled the vascular lesions which are caused by autoimmune reactions. The present study is an attempt to establish the pathologic changes induced by sensitizing the rat against homologous placenta and to compare them with the lesions of kidney in human toxemia. Materials and Methods Healthy male and female rats weighing around 200gm were used and a total of 50 rats were subjected to the experiment . The animals were divided into 4 major groups and treated as follows: Group Ⅰ : Normal control (6 rats) Group Ⅱ : Adjuvant only (6 rats) Group Ⅲ : Placental emulsion with adjuvant (32 rats) A. 14th day whole placenta B. 18th day whole placenta C. Labyrinth of 20th day placenta D. Junctional zone of 20th day placenta Group Ⅳ : Homologous kidney emulsion with adjuvant (6 rats) The antigens were prepared as follows: Placentae were removed on the 14th, 18th, and 20th day of pregnancy. After washing them with sterile isotonic saline solution several times, a 30% saline suspension of placena was made with the tissue homogenizer, and added to the same amount of Freund's complete adjuvant (Difco laboratories, U.S.A.). Antigens were injected at weekly nitervals for eight weeks intra-peritoneally and each dosage was 0.5cc per animal. During this period, body weight and urine protein were checked weekly. All animals were sacrificed and necropsied about 4 to 6 weeks after the last injection of antigen. After gross examination, one part of the kidney was fixed in 10% formalin and cut in 6 micron thickness after paraffin embedding. It was then stained with routine hematoxyline-eosin and Periodic acid Schiff (PAS). For electron microscopic examination, the kidney was subdivided into 3 parts, outer cortex, inner cortex and medulla. Tissues were fixed in 1% osmium tetraoxide in veronal buffer at pH of 7.4, for 2 hours each, and were dehydrated at 4'C in a graded series of ethanol solutions and embedded in Epon 812 or 815. Ultrathin sections were made with glass knife in 400 to 500 A and were stained with uranyl acetate and with lead hydroxide. sections were examined in Hitachi HU-11E electron microscope. Result and Summary The changes of body weight of the rats in Group Ⅰ, Ⅱ and Ⅲ-B were not significant. But in Group Ⅲ-A, Ⅲ-C, and Ⅲ-D, the body weight was markdly increased during 4th to 7th week, and the increment corresponded to 7 to 15% of the body weight at initial point. In group Ⅳ, the body weight decreased 5% during the first week, but gradually increased eventhough they failed to reach normal full recovery. Proteinuria was seen in all animals in Group Ⅲ but in only one in Group Ⅳ. Proteinuria was noted at the 4th week and reached a peak level at the 6th week. At necropsy, the kidney of the rats in group Ⅰ, Ⅱ and Ⅳ disclosed no specific gross changes. In group Ⅲ, increased perirenal fat tissue, mild edematous swelling of the kidney, adherent renal capsule and pale cortex on cut surfaces were noted grossly. On light microscopic examination definite lesions were identified only in the kidneys of the rats in Group Ⅲ. At the glomeruli, the endothelial and epithelial cells were enlarged with narrowed capillary lumen. Thickening of the basement membranes and ischemia were the constant findings and all glomeruli were affected equally. The enlargement of endothelial cells was more prominent in the kidneys of rats in Group Ⅲ-A, and Ⅲ-D, where as the epithelial changes had no group preponderance. Deposition of PAS-positive material was marked in Group Ⅲ-C and mild in remaining subgroups. Ischemic chagnes were more severe in glomeruli in Group Ⅲ-D. At the tubules, mild hyaline changes were noted in proximal and distal tubules with occasional degeneration and destruction of epithelial cells of proximal convoluted tubules, and these lesions were rather severe in Group Ⅲ-C and Ⅲ-D. Thickening of arteriolar walls were also more prominent in Group Ⅲ-C and Ⅲ-D. In Group Ⅳ, only mild changes were noted, such as enlargement of endothelium, proliferation of epithelium and thichkening of arterioles. On electron microscope, the findings of kidneys in control group were not differ from that of reported normal rat kidney. In Group Ⅱ, no ultrastructural alternations were identified, comparing with normal kidney. In Group Ⅲ-A, basement membrane was focally thickened and endothelial cells were enlarged with swollen nuclei and narrowed capillary lumen. The nuclei of the epithelial cells were also enlarge and had irregular chromatin patterns which were clumped at the periphery. The nuclear membranes became indistinct and in the cytoplasm, vacuoles and vesicle appeared in varying sizes and granulated endoplasmic reticulum almost completely disappeared. The Golgi apparatus were swollen and the foot processes were fused to each other with infiltration of membranous materials in Bowman's spaces. Mesangial cells disclosed similar alterations in the endothelium, such as mild enlargement at the capillary axis and decreased density of the cytoplasm. In Group Ⅲ-B and Ⅲ-C, all alterations were more marked, but changes of the nuclear membrane was more mild and occasional osmophilic bodies were found in Group Ⅲ-C. In Group Ⅲ-D, the enlargement of the endothelium is marked and the capillary lumen was almost completely obstructed. The basement membranes were focally thickened and similar to that of Group Ⅲ-B. In summary, the renal lesions which were induced by repeated injection of homologous placenta in rats were closely related to that of human toxemia of pregnancy.restrictio

S사 중심으로

학위논문(석사) - 한국과학기술원 : 경영정보전공, 2008.2, [ v, 70 p. ]급변하는 컨버전스 환경속에서 모바일인터넷 서비스플랫폼은 글로벌 기업들에게 가장 핵심적인 역량 중 하나가 될 것이다. 특히 이동통신과 다른 사업들간의 컨버전스화가 진행되면서 이동통신 사업자들의 모바일 인터넷서비스 플랫폼은 더욱 중요해지고 있다. 동시에 기업전략은 여러분야 기업들의 다양한 서비스모델들과의 협업이 이루어져야만 한다. 그러므로, 기업들은 변화하는 시장과 신기술을 적용한 그들만의 플랫폼관점의 전략을 수립해야 하는 것이다. 본 연구의 주된 목적은 모바일 인터넷 분야의 기업들에게 서비스플랫폼을 제안하는 것이다. 프레임워크는 글로벌 기업들의 사례연구를 기초로 제시되었고 플랫폼센터장과의 인터뷰를 통해 완성되었다. 나아가, 서비스플랫폼 제공자로써 리더쉽을 가질 수 있는 전략을 제안하였다. 본 연구는 서비스 플랫폼에 대한 일반적인 문헌연구와 해외 기업 사례의 문서정보와 기록정보들을 기본으로 최대한 다양한 산업분야의 기업들을 조사해 동일 관점에서의 서비스플랫폼 성장전략 모델을 살펴보는 것을 시작으로 하며 크게 다음과 같은 네 가지 목적을 가지고 있다. 1) 플랫폼전략의 구성요소와 성공요인에 대한 이해 2) 해외 사례연구를 통한 서비스 플랫폼 추진전략과 관련요소 파악 3) S사의 서비스 플랫폼 추진전략과 진행상황 분석 4) 무선인터넷 서비스플랫폼 전략실천을 위한 대응방안 제시 산업의 특성에 따른 세부전략에는 차이가 존재할 수 있으므로 해외 기업사례는 단말기 제조사, 인터넷 포탈, 이동통신사 등 세 가지 영역의 사업자들 사례를 중심으로 살펴보고 국내 기업사례로는 무선 인터넷서비스 산업에서 이동통신사의 영역으로 한정하여 현재까지 이 분야에서 가장 중심적인 역할을 해오고 있는 S기업을 중점적으로 조사한다. 전문가 인터뷰와 직접관찰을 바탕으로 S사의 서비스 플랫폼 전략사례 분석을 통해 치열한 무선 인터넷 환경하에서 필요한 플랫폼 전략을 제시하고 나아가, 다른 영역의 기업들에게 지속적인 성장동력으로써 플랫폼전략을 채택하고 수행해야 하는 진행과정과 필요요인들, 그리고 접근방법에 대해 제시해 보고자 한다.한국과학기술원 : 경영정보전공

충남 <지역순환 농식품체계와 로컬푸드 연구회> 제4회 워크숍 -횡성 꾸러미 네트워킹 사례와 마을사업화 방안 (윤종상 / 텃밭 영농조합법인 대표) * 해외 CSA 사례가 주는 함의 (허남혁 / 충남발전연구원 책임연구원

1. 기조발표 * 횡성 꾸러미 네트워킹 사례와 마을사업화 방안 (윤종상 / 텃밭 영농조합법인 대표) * 해외 CSA 사례가 주는 함의 (허남혁 / 충남발전연구원 책임연구원) 2. 사례발표 3. 지정토론 4. 자유토론1. 기조발표 (14:10~15:00) * 횡성 꾸러미 네트워킹 사례와 마을사업화 방안 (윤종상 / 텃밭 영농조합법인 대표) * 해외 CSA 사례가 주는 함의 (허남혁 / 충남발전연구원 책임연구원) 2. 사례발표 (15:00~16:00) * 전여농 언니네텃밭 사례 (김정열 / 전국여성농민회총연합 언니네텃밭사업단 단장) * 완주 건강밥상꾸러미 사례 (강성욱 / 완주 로컬푸드지원센터 팀장) * 춘천 봄내살림 사례 (이진천 / 봄내살림 대표이사) * 지리산 산내 어머니꾸러미 사례 (정우식 / 지리산친환경영농조합 기획담당) 3. 지정토론 (16:00~16:40) * 안충섭 / 충남농어업6차산업화센터 로컬푸드 담당 * 조영철 / 충남도청 농정과 로컬푸드 담당 * 이재국 / 서천 얼굴있는먹거리 대표 * 배연근 / (주)공생공소 농업회사법인 대표 4. 자유토론 (16:40~17:30