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Permeability changes of the brain capillary endothelial monolayer with different malignancy of co-cultured cell line
No full text의학과/박사[한글]
악성 뇌종양에서 종양주위 부종의 생성기전을 밝히기 위해서 구조적 연구나 생체모델에서의 연구를 통해서 여러 가설들이 있지만 아직도 기전을 설명하기는 어려운 실정이다. 이에 저자는 혈뇌장벽의 체외모델을 만들고, 체외모델을 이용하여 악성도에 따라서 뇌종양의 수용성인자가 증가하여 혈뇌장벽의 투과도가 상승하는 지를 측정하여 이러한 기전에 의해서 악성뇌종양 주위 부종의 생성을 설명할 수 있는지를 확인하고자 하였다.
체외 혈뇌장벽 모델은 뇌미세혈관 내막세포를 단일층으로 배양하여 기본적인 내막세포 단독배양 체외 혈뇌장벽 모델을 구축하고 나서 0.4u크기의 공막으로 2개의 구획으로 분리한 공막분리 동시배양법으로 정상 성상세포와 양성 성상세포를 각각 추가하여 동시배양하였으며, 각 모델에서의 전기저항과 투과도를 측정하여 혈뇌장벽 모델의 선택에 도움이 되고자 하였다. 그 결과 정상 성상세포나 양성 성상세포종 세포를 동시배양하는 경우에 혈관 내막세포만을 단독배양한 경우보다 전기저항이 높고 투과도가 낮았으며, 또한, 동시배양모델중에서는 정상 성상세포를 동시배양할 경우가 혈관내막세포와 양성 성상세포종 세포를 동시배양할 경우보다 투과도가 낮았기 때문에 정상성상세포 동시배양 모델이 가장 체외혈뇌장벽을 실험하는데 이상적일 것으로 사료되었다.
이러한 정상 및 양성 성상세포종 세포를 동시배양한 모델을 이용하여 혈관내막세포와 교모세포종을 동시 배양한 악성종양모델과 비교함으로서 악성도에 따른 뇌종양주위 부종의 악화가 악성 뇌종양에서 분비한 수용성 인자에 의해서 생긴 혈놔장벽의 투과도 변화와 관계가 있는지를 확인하고자 하였다. 종양 세포가 통과 할 수 없는 0.4u 크기의 공막으로 배양관을 2개구획으로 분리하여 배양액만이 순환될 수 있게 된 공막분리 동시배양법으로 교모세포종을 동시배양하였다. 분자량 373에서 양성 성상세포종을 동시배양한 모델에서는 정상 성상세포를 동시배양한 경우보다 혈관내막세포의 투과도가 150%까지 증가하였고, 교모세포종을 동시배양한 모델에서는 혈관내막세포의 투과도가 240%까지 증가하여 악성도가 높을수록 투과도가 증가하였다. 또한, 정상 성상세포, 양성 성상세포종, 그리고
교모세포종을 배양한 배양액을 각각 사용하여 혈관내막세포를 배양한 경우에도 정상 성상세포 배양액을 사용한 경우보다 혈관내막세포층의 투과도가 각각 36%, 131% 가 증가하였다. 전기저항은 양성 성상세포종을 동시배양한 모델에서 정상 성상세포를 동시배양한 경
우보다 15% 감소하였고, 교모세포종을 동시배양한 모델에서는 19% 감소하여 전기저항은 악성도가 증가함에 따라서 감소하였으며, 전기저항에 따른 투과도는 반비례 관계를 보였다(R2=0.94). 악성도의 증가에 따라 정상 성상세포, 양성 성상세포종, 그리고 교모세포종 각각의 동시배양모델에서 투과도가 의의있게 증가하였으며, 전기저항은 감소하였다. 이러한 동시 배양 모델은 비접촉적 공막분리법으로 배양되었으므로 동시배양된 각 세포가 혈관 내막세포에 영향을 주어 투과도를 변화시켜야하므로 0.4u크기의 공막을 통과한 수용성 물질로 추정된다.
결국, 체외혈뇌장벽 모델로서 전기저항이나 투과도에 있어서 혈관내막세포 단독배양보다 동시배양 모델이 이상적이며, 이러한 모델을 사용하여 뇌종양의 악성도에 따라서 혈뇌장벽의 투과도가 증가하였다. 따라서 악성 뇌종양에서 동반되는 뇌부종은 종양세포에서
방출하는 수용성 물질에 의해서 혈관 내막세포의 투과도가 증가한 결과로 추정할 수 있었다. 혈관 내막세포의 투과도를 증가시키는 수용성 물질의 규명에 대해서는 계속적인 연구가 이루어져야 할 것으로 사료된다.
[영문]
It is still impossible to explain the mechanism of peritumoral edema in the malignant brain tumors even though there are many hypothesis derived from the anatomical and functional analysis in vivo model of brain tumor. The author tried to establish in vitro blood-brain-barrier model and to confirm elevation of permeability of blood-brain barrier model correlated with malignancy of co-cultured brain tumor through the water-soluble factors that could explain the pathogenetic mechanism of peritumoral edema of malignant brain tumors. Author established in vitro blood-brain barrier model from the brain capillary endothelial monolayer, and compared trans-endothelial permeability and electrical resistance in a endothelial monolayer mode! and two co-culture models which were made with co-cultured normal astrocyte or benign astrocytoma cell line in the second comparenent circumscribed with 0.4u sized porous membrane. Among these three models, the endothelial monolayer only showed highest permeability, the astrocytoma co-cultured model medium permeability and the normal astrocyte co-cultured model lowest one. Permeability and electrical resistance were in the inverse correlation among these three models. As a results, it was suggested that the normal aslrocyte co-culture model was much more ideal for blood-brain barrier model in the aspect of permeability and electrical
Author estimated the permeability changes with malignancy of co-cultured cells compared to normal astrocyte co-culture models to elucidate the characteristics of causative factors for the perihunoral edema in malignant brain tumors. The malignant cell co-culture model was made with co-cultured glioblastoma cell lines such as 87MG and 373MG in the second compartment circumscribed with 0.4u sued 77r7us membrane that could permit medium communication but limit cell migration to another compartment. Permeability at molecular weight 373 increased in the astrocytoma co-culture model and the glioblastoma co-cultured model up to 150% and 240% respectively more than that of normal astrocyte co-culture model. Permeability at molecular weight 373 also increased in the astrocytoma-conditioned medium culture model and the glioblastoma-conditioned medium culture model up to 38% and 131% respectively more than that of normal astrocytoma-conditioned medium culture model. Trans-endothelial electrical resistance was decreased in the astrocytoma co-culture model and the glioblastoma co-culture model about 15% and 19% respectively and these suggest electrical resistance become decreased according to malignancy of co-cultured cells. Electrical resistance was inversely correlated to permeability(R2=0.94). Results was that permeability of endothelial monolayer became increased with the malignancy of co-cultured cells in the system permitting media transfer only except cell migration.
These suggest some factor soluble in media secreted from co-cultured cells make action to change permeability of the endothelial monolayer and could be applied to explain pathogenetic mechanism of peritumoral edema of the malignant brain tumors.restrictio
Clinical Analysis of Intracranial Arteriovenous Malformations
No full text의학과/석사[영문]
[한글]
두개강내 동정맥 기형은 근본적인 치료를 위해서는 수술적 치료에 의존하여야 하나, 수
술후 뇌기능 장애의 위험성으로 수술적 치료를 시도하기가 어렵다. 그러나 과거 20년간
진단방법의 발달과 함께 마취학과 수술수기도 장족의 진보를 보이면서, 과거의 소극적 치
료에서 적극적 치료로 전환되어 왔으며, 좀 더 구체적인 이해를 통한 새로운 치료지침이
요구되었다.
1977년부터 1985년까지 연세대학교 의과대학 부속 세브란스 병원 신경외과에서 치험한
두개강내 동정맥 기형 66예를 분석 고찰하여 다음과 같은 결과를 얻었다.
1. 환자의 연령은 10대와 30대에 가장 많이 분포하여 전체의 77.3%를 차지하였으며, 약
2:1로 남자에서 많았다.
2. 내원 당시 주 증상은 출혈에 의한 증상이 75%, 비출혈성 증상에서는 전간발작이 14.
1%로 가장 많았다.
3.뇌전산화 단층촬영 소견 상, 93.3%에서 진단이 가능하였으며, 약 반 수 정도에서 확
진이 가능하였으며, 전간이나 경도의 신경학적 증상을 보이는 경우 일차적 예비검사로서
진단 가치가 높았다. 확진에 가장 중요한 소견은 tubular enhanced shadow였고, 조영전
뇌전산화 단층촬영 소견으로는 고밀도를 보인 경우가 42.1%로 가장 많았다.
4. 대뇌피질 및 피질하부에 동정맥기형이 위치한 예는 75.4%였고, 대뇌심부는 14.8%를
차지하였고, 천막하에 생기거나 경막에 생긴 병소가 각각 4.8%였다.
5. 크기에 따른 출혈빈도는 직경이 4㎝이상인 경우와 2㎝ 이하인 경우에 높았고, 2㎝-4
㎝ 사이인 경우에는 낮았다. 천막상 병소는 피질하부와 심부에 따른 출혈빈도의 차이가
없었으며, 천막하 병소 3예는 모두 출혈성이었다.
6. Luessenhop분류상 I등급이 가장 많아 46.6%를 차지하였으며, 전대뇌동맥과 중대뇌동
맥의 참여가 가장 많았다.
7. 개두술을 시행하였던 43예 중, 79.1%에서 완전절제 하였고, 이중 Luessenhop 분류를
할 수 있었던 36예에서 72.2%가 Ⅰ-Ⅱ등급이었다. 동정맥 기형의 크기와 위치 때문에 수
술이 불가능하였던 경우가 14.6%이었다.
8. 수술치료를 받은 48예 중 12.5%에서 수술 직후 신경학적 증상의 악화가 있었다.
9. 수술여부에 관계없이 퇴원 시에는 입원시보다 Ⅰ등급인 예가 증가하였고, Ⅳ등급인
경우에는 수술치료를 받은 군에서는 감소하였으나 수술 받지 않은 군에서는 증가하였다.
10. 개두술로 치료받은 19명의 장기추적 결과는 63.2%에서 증세가 호전하였으며 악화된
예는 없었다.
11. Luessenhop분류상 Ⅰ-Ⅱ등급은 적극적으로 수술을 하는 것이 바람직하며, Ⅲ-Ⅳ등
급에서는 나이가 40세 이상인 경우에는 수술의 적용이 어렵고, 40세 이하인 경우에는 위
험 요인을 신중하게 분석한 후 수술을 결정하는 것이 바람직한 것으로 사료되었다.
Clinical analysis of Intracranial Arteriovenous Malformations
Soo Han Yoon
Department of Medical Science, Graduate School, Yonsei University
(Directed by Prof. Kyu Chang Lee, M.D.)
surgical resection is the ost absolute treatment method of arteriovenous
malformation. However, because of the risks of neurological deficit, surgical
intervention cannot be considered in many cases.
Development in better methods of diagnosis, anesthesiology and surgery of this
lesions has replaced previous passive management with more aggresive treatment.
therefore, there is an urgent need of new criteria for evaluation and treatment of
arteriovenous malformations which is based on better understanding of natural
course and hemodynamics of these lesions.
The author analyzed 66 cases of intracranial arteriovenous malformations treated
in the Department of Neurosurgery of Yonsei University Hospital from 1977 to 1985.
The analized results are summarized as follows:
1. The ratio of male to female was 2:1 and 75.8% or 50 cases were distributed
bewteen the 2nd and 4th decade.
2. The common presenting symptoms were either seizure alone (14%) or various
symptoms resulting from hemorrhage (75%).
3. Arteriovenous malformations were suggested in 93.3% and were diagnosed in
about half of the cases with the brain CT scan.
Enhanced tubular shadow was the most important finding and hyperdensity of the
lesion on precontrast brain CT scan was themost common finding.
4. The most common site of involvement was the supratentorial subcortical region
with 75.4%, followed by the supratentorial deep region with 14.8X, and the
infratentorial and dosal region with 4.8%.
5. When compared to small (4cm) lesions, there was less chance
of hemorrhage in medium sized lesion(>2cm to <4cm). When the subcortical and deep
regions of the supratentorial lesion were compared, there was no difference in
incidence of hemorrhage.
6. According to angiographic findings, 46.6% was grade Ⅰ lesions.
The anterior cerebral artery and the middlecerebral artery were most commonly
involved.
7. After craniotomy, total resection was performed in 334 of 43 cases or 79.1%.
Due to either size or location, 14.4% or 7 of 43 cases were inoperable.
8. Immediate postoperative neurological deficits were noted in 12.5% or 6 of 48
cases. Non-hemorrhagic patients showed postoperative deficits more frequently than
hemorrhagic patient did.
9. Regardless of treatment modality, there was a significant increase in number
of patients who could be classified as grade Ⅰ at discharge.
10. Long-term follow-up was carried out on 19 craniotomy cases. Neurological
improvement was noted in 63.2% of these 19 cases. Among this group, there was no
case of neurological deterioration.
11. Our findings indicate that surgery is the best treatment method for cases
included in grade Ⅰ and Ⅱ. Age is found to be an important factor in group Ⅲ and
Ⅳ. In cases over 40 years of age, surgical intervention is not advisable. In cases
bellow 40 years of age, surgical intervention is possible after careful evaluation.restrictio
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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