• 제목/요약/키워드: Repetition

검색결과 1,575건 처리시간 0.037초

양성자 자기공명분광법을 이용한 우울증 동물모델에서의 항우울제 약물 효능 평가 (Evaluation of Antidepressant Drug Effect in a Depressive Animal Model by Proton MR Spectroscopy)

  • 김상영;최치봉;이성호;우동철;윤성익;홍관수;이현승;정재준;지보근;홍승탁;김휘율;최보영
    • 한국의학물리학회지:의학물리
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    • 제19권2호
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    • pp.95-101
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    • 2008
  • 본 기초연구에서는 강제수영검사(forced swimming test, FST)에 의해 우울증이 유발된 쥐의 해마(hippocampus) 부위에서 뇌 대사물질(brain metabolites)중에 choline 신호의 변화를 관찰하였다. 본 연구의 목적은 우울증이 유발된 쥐에 항우울제인 desipramine-HCl을 투여하여 정상 쥐와 약물을 투여한 쥐 사이의 뇌 대사물질의 차이를 자기공명분광법(magnetic resonance spectroscopy: MRS)을 통하여 알아보는 것이다. 실험대상으로는 6주령의 SD rat을 사용하였으며 우울증을 유발시키고 항우울제의 약물평가를 위한 모델링 방법으로 강제수영검사를 시행하였다. 자기공명분광법을 시행하기 위한 localization 방법으로는 PRESS 펄스시퀀스를 사용하였다(TR: 2,500 ms, TE: 144 ms, averaging: 512, complex data point: 2048, scan time: 25 min). 정상 쥐 그룹과 우울증을 유발시킨 뒤 항우울제를 투여한 쥐 그룹 모두 양쪽 해마부위에서의 NAA/Cr, Cho/Cr 비율(ratio)은 차이가 나지 않았다. 또한 왼쪽 해마에서 정상 쥐와 항우울제를 투여한 쥐 사이에서 NAA/Cr, Cho/Cr 비율도 차이가 나지 않았고, 오른쪽 해마부위에서도 통계적으로 유의한 차이가 없었다. 본 연구를 통하여 anti-immobility효과를 나타내는 항우울제를 투여함으로써 choline 신호가 정상 쥐와 비슷하게 회복되는 것을 관찰하였다. 이는 앞으로의 항우울제 약물 평가에 있어 자기공명분광법을 도입함으로써 기존의 주관적인 판단을 배제할 수 없었던 행동변화분석만으로 항우울제의 효과를 평가하는 방법에 비해 객관적이고 정량적인 분석을 할 수 있다는 점에서 아주 유용한 방법이라 사료된다.

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소뇌와 뇌교의 정상 자기공명분광 소견: 같은 장비내 및 다른 장비간의 결과 비교 (Normal MR Spectroscopic Findings of the Cerebellum and Pons: Comparison of the Results between Intra-Unit and Inter-Unit Studies)

  • 최준일;장기현;송인찬;도강현;이준우
    • Investigative Magnetic Resonance Imaging
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    • 제5권2호
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    • pp.123-129
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    • 2001
  • 목적 : 정상 성인에셔 소뇌와 뇌교의 MRS의 정상 소견과 대사물질비의 정상값을 구하고, 같은 장비에서 반복 시행한 결과의 차이와 다른 장비간의 결과의 차이가 어느 정도인지를 알아보고자 하였다. 대상 및 방법 : 건강한 9명의 정상 자원자(평균연령 23세)를 대상으로 두 개의 서로 다론 1.5T MR 장비 (A, B 장비)에서 각각 두 번씩 총 4회의 MRS를 양측 소뇌 반구와 뇌교에셔 시행하였 다. 스핀에코 단일화적소기법을 이용하였고 소뇌에서는 $2{\times}2{\times}1.5{\;}em$의 voxel 크기를, 뇌교 에서는 $1.5{\times}1.5{\times}1.5{\;}cm$의 voxel을 적용하였다. TR/TE는 2000/288 msec, Averaging 은 128회로 하였다. 소뇌와 뇌교의 NAA/Cho, NAA/Cr, NAA/(Cho+Cr), Cr/Cho 비를 peak height와 peak area로 각각 구하여, 같은 장비 내 (intra-unit) , 그리고 다론 장비간 (inter-unit)의 정상값에 유의한 차이가 있는지를 알아보았다. 결과 : A 장비에서 첫번째로 시행한 peak height NAA/Cho, NAA/Cr, NAA/(Cho+ Cr), CriCho 비의 평균값(표준편차는 소뇌에서 각각 $1.08{\pm}0.16,{\;}1.44{\pm}0.286,{\;}0.61{\pm}0.09,{\;}0.76{\pm}0.13$ 였고, 두번째 시행한 결과와 비교할 때 장비내 차이는 3-7% 였다. B장비에서 시 행한 2회의 검사 사이에서는 22% 의 차이를 보인 Cr/Cho를 제외하면 1-9% 의 장비내 차이 를 보였다. A, B 두 장비 간 차이는 1-26%였다. 뇌교에서는 A장비 첫번째 peak height 측정 치는 $1.51{\pm}0.35,{\;}3.35{\pm}0.78,{\;}1.02{\pm}0.16,{\;}0.47{\pm}0.14$로서, 소뇌보다 NAA/Cho, NAA/Cr, NAA!(Cho+Cr) 비가 유의하게 높았다. 장비내 차이는 A장비에서 2-21 %였고, B장비에서 4-18%였다. A, B 두 장비간 차이는 1-18% 였다. peak area로 구한 대사산물비의 평균값은 peak height 의 그것에 비해 전반적으로 두 장비에서 높거나 광범위한 변이를 보였다. 결론 : 소뇌의 NAA/Cho과 NAA/Cr의 평균값이 뇌교의 그것보다 유의하게 낮았다. 같은 장비 내에서 반복 시행한 평균값의 차이는 대체적으로 유의한 차이가 없었으나, 다른 장비에서 반복 시행한 장비간의 사이에는 유의한 차이가 있는 경우가 더 많았다. 따라서 , MRS 검사를 소뇌나 뇌교의 어떤 절환에 적용하기 전에 각 장비 마다 정상 기준치를 반드시 얻은 후에 이상여부를 판 정하는 것이 필수적이라고 생각된다.

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Analysis of Image Distortion on Magnetic Resonance Diffusion Weighted Imaging

  • Cho, Ah Rang;Lee, Hae Kag;Yoo, Heung Joon;Park, Cheol-Soo
    • Journal of Magnetics
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    • 제20권4호
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    • pp.381-386
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    • 2015
  • The purpose of this study is to improve diagnostic efficiency of clinical study by setting up guidelines for more precise examination with a comparative analysis of signal intensity and image distortion depending on the location of X axial of object when performing magnetic resonance diffusion weighted imaging (MR DWI) examination. We arranged the self-produced phantom with a 45 mm of interval from the core of 44 regent bottles that have a 16 mm of external diameter and 55 mm of height, and were placed in 4 rows and 11 columns in an acrylic box. We also filled up water and margarine to portrait the fat. We used 3T Skyra and 18 Channel Body array coil. We also obtained the coronal image with the direction of RL (right to left) by using scan slice thinkness 3 mm, slice gap: 0mm, field of view (FOV): $450{\times}450mm^2$, repetition time (TR): 5000 ms, echo time (TE): 73/118 ms, Matrix: $126{\times}126$, slice number: 15, scan time: 9 min 45sec, number of excitations (NEX): 3, phase encoding as a diffusion-weighted imaging parameter. In order to scan, we set b-value to $0s/mm^2$, $400s/mm^2$, and $1,400s/mm^2$, and obtained T2 fat saturation image. Then we did a comparative analysis on the differences between image distortion and signal intensity depending on the location of X axial based on iso-center of patient's table. We used "Image J" as a comparative analysis programme, and used SPSS v18.0 as a statistic programme. There was not much difference between image distortion and signal intensity on fat and water from T2 fat saturation image. But, the average value depends on the location of X axial was statistically significant (p < 0.05). From DWI image, when b-value was 0 and 400, there was no significant difference up to $2^{nd}$ columns right to left from the core of patient's table, however, there was a decline in signal intensity and image distortion from the $3^{rd}$ columns and they started to decrease rapidly at the $4^{th}$ columns. When b-value was 1,400, there was not much difference between the $1^{st}$ row right to left from the core of patient's table, however, image distortion started to appear from the $2^{nd}$ columns with no change in signal intensity, the signal was getting decreased from the $3^{rd}$ columns, and both signal intensity and image distortion started to get decreased rapidly. At this moment, the reagent bottles from outside out of 11 reagent bottles were not verified from the image, and only 9 reagent bottles were verified. However, it was not possible to verify anything from the $5^{th}$ columns. But, the average value depends on the location of X axial was statistically significant. On T2 FS image, there was a significant decline in image distortion and signal intensity over 180mm from the core of patient's table. On diffusion-weighted image, there was a significant decline in image distortion and signal intensity over 90 mm, and they became unverifiable over 180 mm. Therefore, we should make an image that has a diagnostic value from examinations that are hard to locate patient's position.

A Study on Relationship between Physical Elements and Tennis/Golf Elbow

  • Choi, Jungmin;Park, Jungwoo;Kim, Hyunseung
    • 대한인간공학회지
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    • 제36권3호
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    • pp.183-196
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    • 2017
  • Objective: The purpose of this research was to assess the agreement between job physical risk factor analysis by ergonomists using ergonomic methods and physical examinations made by occupational physicians on the presence of musculoskeletal disorders of the upper extremities. Background: Ergonomics is the systematic application of principles concerned with the design of devices and working conditions for enhancing human capabilities and optimizing working and living conditions. Proper ergonomic design is necessary to prevent injuries and physical and emotional stress. The major types of ergonomic injuries and incidents are cumulative trauma disorders (CTDs), acute strains, sprains, and system failures. Minimization of use of excessive force and awkward postures can help to prevent such injuries Method: Initial data were collected as part of a larger study by the University of Utah Ergonomics and Safety program field data collection teams and medical data collection teams from the Rocky Mountain Center for Occupational and Environmental Health (RMCOEH). Subjects included 173 male and female workers, 83 at Beehive Clothing (a clothing plant), 74 at Autoliv (a plant making air bags for vehicles), and 16 at Deseret Meat (a meat-processing plant). Posture and effort levels were analyzed using a software program developed at the University of Utah (Utah Ergonomic Analysis Tool). The Ergonomic Epicondylitis Model (EEM) was developed to assess the risk of epicondylitis from observable job physical factors. The model considers five job risk factors: (1) intensity of exertion, (2) forearm rotation, (3) wrist posture, (4) elbow compression, and (5) speed of work. Qualitative ratings of these physical factors were determined during video analysis. Personal variables were also investigated to study their relationship with epicondylitis. Logistic regression models were used to determine the association between risk factors and symptoms of epicondyle pain. Results: Results of this study indicate that gender, smoking status, and BMI do have an effect on the risk of epicondylitis but there is not a statistically significant relationship between EEM and epicondylitis. Conclusion: This research studied the relationship between an Ergonomic Epicondylitis Model (EEM) and the occurrence of epicondylitis. The model was not predictive for epicondylitis. However, it is clear that epicondylitis was associated with some individual risk factors such as smoking status, gender, and BMI. Based on the results, future research may discover risk factors that seem to increase the risk of epicondylitis. Application: Although this research used a combination of questionnaire, ergonomic job analysis, and medical job analysis to specifically verify risk factors related to epicondylitis, there are limitations. This research did not have a very large sample size because only 173 subjects were available for this study. Also, it was conducted in only 3 facilities, a plant making air bags for vehicles, a meat-processing plant, and a clothing plant in Utah. If working conditions in other kinds of facilities are considered, results may improve. Therefore, future research should perform analysis with additional subjects in different kinds of facilities. Repetition and duration of a task were not considered as risk factors in this research. These two factors could be associated with epicondylitis so it could be important to include these factors in future research. Psychosocial data and workplace conditions (e.g., low temperature) were also noted during data collection, and could be used to further study the prevalence of epicondylitis. Univariate analysis methods could be used for each variable of EEM. This research was performed using multivariate analysis. Therefore, it was difficult to recognize the different effect of each variable. Basically, the difference between univariate and multivariate analysis is that univariate analysis deals with one predictor variable at a time, whereas multivariate analysis deals with multiple predictor variables combined in a predetermined manner. The univariate analysis could show how each variable is associated with epicondyle pain. This may allow more appropriate weighting factors to be determined and therefore improve the performance of the EEM.

중학교 "환경" 교과의 교수.학습 및 평가 방법 연구 (A Study on Teaching-Learning and Evaluation Methods of Environmental Studies in the Middle School)

  • 남상준
    • 한국환경교육학회지:환경교육
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    • 제7권1호
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    • pp.1-17
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    • 1994
  • This study was performed to determine appropriate teaching-learning and evaluation methods for Environmental Studies. To promote the relevance of our study to the needs of the schools and concerned educational communities of environmental education, we reviewed related literature, conducted questionnaire surveys, interviewed related teachers and administrator, held meetings with experts, and field-tested our findings. For selecting and developing teaching-learning methods of Environmental Studies, findings of educational research in general are considered. moreover, principles of environmental education, general aim of environmental education, orientations of environmental education, and developmental stages of middle school students in educational psychology were attended. In addition, relevance to the purpose of the Environmental Studies curriculum, appropriateness for value inquiry as well as knowledge inquiry, small group centered class organization, social interaction centered teaching-learning process, regional environmental situation, significance of personal environment, evaluation methods of Environmental Studies, multi- and inter-disciplinary contents of the Environmental Studies textbook, suitability to the evaluation methods of Environmental Studies, and emphasis on the social interaction in teaching-learning process were regarded. It was learned the Environmental Studies can be taught most effectively in via of holding discussion sessions, conducting actual investigation, doing experiment-practice, doing games and plate, role-playing and carrying out simulation activities, and doing inquiry. These teaching-learning methods were field-tested and proved appropriate methods for the subject. For selecting and developing evaluation method of Environmental Studies, such principles and characteristics of Environmental Studies as objective domains stated in the Environmental Studies curriculum, diversity of teaching-learning organization, were appreciated. We categorized nine evaluation methods: the teacher may conduct questionnaire surveys, testings, interviews, non-participatory observations; they may evaluate student's experiment-practice performances, reports preparation ability, ability to establish a research project, the teacher may ask the students to conduct a self-evaluation, or reciprocal evaluation. To maximize the effect of these methods, we further developed an application system. It considered three variables, that is, evaluates, evaluation objectives domains, and evaluation agent, and showed how to choose the most appropriate methods and, when necessary, how to combine uses of different methods depending on these variables. A sample evaluation instrument made on the basis of this application system was developed and tested in the classes. The system proved effective. Pilot applications of the teaching-learning methods and evaluation method were made simultaneously; and the results and their implications are as follows. Discussion program was applied in a lesson dealing with the problems of waste disposal, in which students showed active participation and creative thinking. The evaluation method used in this lesson was a multiple-choice written test for knowledge and skills. It was shown that this evaluation method and device are effective in helping students' revision of the lesson and in stimulating their creative interpretations and responces. Pupils showed great interests in the actual investigation program, and this programme was proved to be effective in enhancing students' participation. However, it was also turned out that there must be pre-arranged plans for the objects, contents and procedures of survey if this program is to effective. In this lesson, non-participatory observation methods were used with a focus on the attitudes of students. A scaled reported in general description rather than in grade. Experiment-practice programme was adopted in a lesson for purifying contaminated water and in this lesson, instruction objectives were properly established, the teaching-learning process was clearly specified and students were highly motivated. On the other hand, however, it was difficult to control the class when some groups of students require more times to complete their experiment, and sometimes different results. As regards to evaluation, performance observation test were used for assessing skills and attitudes. If teachers use well-prepared Likert scale, evaluation of all groups within a reasonablely short period of time will be possible. The most effective and successful programme in therms of students' participation and enjoyment, was the 'ah-nah-bah-dah-market' program, which is kind of game of the flea market. For better organized program of this kind, however, are essential, In this program, students appraise their own attitudes and behavior by responding to a written questionnaire. In addition, students were asked to record any anecdotes relating to self-appraisal of changes on one's own attitudes and behaviours. Even after the lesson, students keep recording those changes on letters to herself. Role-playing and simulation game programme was applied to a case of 'NIMBY', in which students should decide where to located a refuse dumping ground. For this kind of programme to e successful, concepts and words used in the script should be appropriate for students' intellectual levels, and students should by adequately introduced into the objective and the procedures of the lessons. Written questionnaire was used to assess individual students' attitudes after the lesson, but in order to acquire information on the changes of students' attitudes and skills, pre-test may have to be made. Doing inquiry programme, in which advantages in which students actually investigated the environmental influence of the areas where school os located, had advantages in developing students' ability to study the environmental problems and to present the results of their studies. For this programme to be more efficient, areas of investigation should be clearly divided and alloted to each group so that repetition or overlap in areas of study and presentation be avoided, and complementary wok between groups bee enhanced. In this programme, teacher assessed students' knowledge and attitudes on the basis of reports prepared by each group. However, there were found some difficults in assessing students' attitudes and behaviours solely on the grounds of written report. Perhaps, using a scaled checklist assessing students' attitudes while their presentation could help to relieve the difficulties.

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Prosodic Phrasing and Focus in Korea

  • Baek, Judy Yoo-Kyung
    • 대한음성학회:학술대회논문집
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    • 대한음성학회 1996년도 10월 학술대회지
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    • pp.246-246
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    • 1996
  • Purpose: Some of the properties of the prosodic phrasing and some acoustic and phonological effects of contrastive focus on the tonal pattern of Seoul Korean is explored based on a brief experiment of analyzing the fundamental frequency(=FO) contour of the speech of the author. Data Base and Analysis Procedures: The examples were chosen to contain mostly nasal and liquid consonants, since it is difficult to track down the formants in stops and fricatives during their corresponding consonantal intervals and stops may yield an effect of unwanted increase in the FO value due to their burst into the following vowel. All examples were recorded three times and the spectrum of the most stable repetition was generated, from which the FO contour of each sentence was obtained, the peaks with a value higher than 250Hz being interpreted as a high tone (=H). The result is then discussed within the prosodic hierarchy framework of Selkirk (1986) and compared with the tonal pattern of the Northern Kyungsang dialect of Korean reported in Kenstowicz & Sohn (1996). Prosodic Phrasing: In N.K. Korean, H never appears both on the object and on the verb in a neutral sentence, which indicates the object and the verb form a single Phonological Phrase ($={\phi}$), given that there is only one pitch peak for each $={\phi}$. However, Seoul Korean shows that both the object and the verb have H of their own, indicating that they are not contained in one $={\phi}$. This violates the Optimality constraint of Wrap-XP (=Enclose a lexical head and its arguments in one $={\phi}$), while N.K. Korean obeys the constraint by grouping a VP in a single $={\phi}$. This asymmetry can be resolved through a constraint that favors the separate grouping of each lexical category and is ranked higher than Wrap-XP in Seoul Korean but vice versa in N.K. Korean; $Align-x^{lex}$ (=Align the left edge of a lexical category with that of a $={\phi}$). (1) nuna-ka manll-ll mEk-nIn-ta ('sister-NOM garlic-ACC eat-PRES-DECL') a. (LLH) (LLH) (HLL) ----Seoul Korean b. (LLH) (LLL LHL) ----N.K. Korean Focus and Phrasing: Two major effects of contrastive focus on phonological phrasing are found in Seoul Korean: (a) the peak of an Intonatioanl Phrase (=IP) falls on the focused element; and (b) focus has the effect of deleting all the following prosodic structures. A focused element always attracts the peak of IP, showing an increase of approximately 30Hz compared with the peak of a non-focused IP. When a subject is focused, no H appears either on the object or on the verb and a focused object is never followed by a verb with H. The post-focus deletion of prosodic boundaries is forced through the interaction of StressFocus (=If F is a focus and DF is its semantic domain, the highest prominence in DF will be within F) and Rightmost-IP (=The peak of an IP projects from the rightmost $={\phi}$). First Stress-F requires the peak of IP to fall on the focused element. Then to avoid violating Rightmost-IP, all the boundaries after the focused element should delete, minimizing the number of $={\phi}$'s intervening from the right edge of IP. (2) (omitted) Conclusion: In general, there seems to be no direct alignment constraints between the syntactically focused element and the edge of $={\phi}$ determined in phonology; all the alignment effects come from a single requirement that the peak of IP projects from the rightmost $={\phi}$ as proposed in Truckenbrodt (1995).

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Er:YAG laser와 Conventional bur의 유치와 영구치 치아삭제효과 비교 (CUTTING EFFICACY OF Er:YAG LASER AND CONVENTIONAL BUR IN DECIDUOUS AND PERMANENT TEETH)

  • 박인천;이창섭;이난영;이상호
    • 대한소아치과학회지
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    • 제30권2호
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    • pp.272-285
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    • 2003
  • 본 연구는 유치와 영구치의 법랑질과 상아질을 bur를 이용하여 삭제한 경우와 Er:YAG laser를 이용하여 삭제한 경우 형성되는 와동의 미세학적인 형태를 관찰하고 삭제 효과를 비교하기 위함이다. 유치와 영구치의 법랑질과 상아질을 #330 bur 와 5 Hz의 150mJ, 200mJ, 250mJ 그리고 300mJ 조사세기로 Er:YAG laser를 조사하여 1mm 두께의 표본이 삭제되는 시간을 측정하였다. 또한 삭제된 표면을 관찰하기 위해서 유치와 영구치 각각 5개에 #330 bur와 5Hz의 150mJ, 200mJ, 250mJ, 300mJ 조사세기로 Er:YAG laser를 1초동안 조사하여 횡단면과 종단면으로 나누어 관찰하였다. 1. Er:YAG 레이저를 사용하여 삭제한 경우 유치와 영구치, 법랑질과 상아질 모두 bur를 이용하여 삭제한 경우보다 삭제 시간이 길었다(P<0.05). 2. 법랑질을 삭제할 경우 bur를 사용시 영구치보다 유치에서 삭제시간이 더 길었다. 그러나 Er:YAG 레이저 사용시에는 유치와 영구치 사이에 유의한 차이를 보이지 않았다(P>0.05). 3. 상아질을 삭제할 경우 bur사용시 영구치에서 삭제시간이 더 길었으며 Er:YAG레이저 사용시 150mJ, 5Hz에서는 유의하게 영구치에서 더 긴 삭제시간을 보였으나 나머지 다른 출력의 레이저에서는 유의한 차이를 보이지 않았다(P<0.05). 4. SEM 관찰시 bur를 이용하여 치아를 삭제한 경우 치질유형에 관계없이 경계가 비교적 명확한 와동 변연을 보였다. 그러나 와동 변연에서 균열과 $10-100{\mu}m$의 microchipping이 관찰되었다. 와동벽은 회전식 bur에 따른 줄무늬 모양의 표면을 보이고 있었다. 편평한 와동저를 관찰할 수 있었으며 역시 와동벽과 마찬가지로 거친 표면을 보이고 있었다. 5. 레이저를 이용하여 치아를 삭제한 경우 와동의 변연이 명확하고 날카롭게 형성되었다. 와동의 상부의 직경은 조사에너지와 pulse repetition rate가 커질수록 점차 증가하였다. 와동벽은 불규칙하게 배열되었으며 와동의 변연이나 바닥에 비해 불규칙한 양상을 보여주었다. 와동저는 일반적으로 둥근 원추형이며 비교적 부드러운 표면을 보였다. 이상의 결과를 요약해보면 Er:YAG 레이저는 유치와 영구치에서 비슷한 삭제 시간이 소요되었다. 그러나, 법랑질보다는 상아질에 더 효과적인 것으로 나타났다. 실험 결과 레이저를 이용하여 치아를 삭제한 경우 bur사용에 비해 3배 이상의 삭제시간이 소요되었다. 그러나, 레이저를 이용하여 치아를 삭제할 경우 깨끗한 와동 변연이 형성되고 smear layer가 형성되지 않는 점이 장점으로 사료된다.

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연속조명과 폭염 스트레스가 육계의 혈액지질 및 성장능력에 미치는 영향 (Effects of extreme heat stress and continuous lighting on growth performance and blood lipid in broiler chickens)

  • 박상오;황보종;류채민;윤재성;박병성;강환구;서옥석;채현석;최희철;최양호
    • 한국응용과학기술학회지
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    • 제30권1호
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    • pp.78-87
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    • 2013
  • 본 연구는 연속조명과 함께 폭염 스트레스(extreme heat stress, EHS)에 노출된 브로일러에서 폭염사료 급여가 혈액지질, 성장능력, 면역기관, 혈청 면역물질, 맹장 미생물 변화에 미치는 영향을 조사하였다. 일반 환경온도 ($25^{\circ}C$) 또는 폭염스트레스 ($33{\pm}2^{\circ}C$)하에서 사육한 병아리는 일반사료(chow diet, CD)와 폭염사료(extreme heat diet, EHD)를 섭취하였다. 부화 당일 Ross 308 병아리 500 마리를 5 처리구 4 반복(반복 펜 당 25 마리)으로 완전임의배치 하였다. T1 (일반환경+CD), T2 (EHS+CD), T3 (EHS+CD 내 우지를 대두유로 대체 및 당밀 5%를 함유하는 EHD), T4 (EHS+CD 내 우지를 대두유로 대체, 당밀 5%, 메치오닌과 라이신을 각각 CD 의 1.5 배씩 함유하는 EHD), T5 (폭염+CD 내 우지를 대두유로 대체, 당밀 5%, 메치오닌과 라이신을 각각 CD 의 1.5 배씩 추가 및 비타민 C 300 ppm 을 함유하는 EHD)로 구분하였다. EHS 는 체중 및 사료섭취량을 유의하게 감소하였다. 혈액지질, 혈액 면역물질, F 낭, 흉선 그리고 비장의 무게는 브로일러를 EHS 에 노출하였을 때 유의하게 낮아졌다. 일반 환경온도 처리군과 비교할 때 EHS 처리군에서 맹장 Lactobacillus sp.는 낮았으나 Escherichia sp., Salmonella sp. 및 총호기성균은 높게 나타났으며 각 처리구 사이의 통계적인 유의차가 인정되었다.

제대정맥 내피세포에서 Amiloride 유도체에 의한 Apoptosis 반복 (Repetition of Apoptosis Induced by Amiloride Derivatives in Human Umbilical Vein Endothelial Cells)

  • 박규창;박규상;문수지
    • Clinical and Experimental Pediatrics
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    • 제46권1호
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    • pp.56-66
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    • 2003
  • 목 적 : 제대정맥은 모체의 혈액을 태아로 운반하여 산소와 영양물질을 공급하는 유일한 통로이다. 이러한 제대 혈류의 장애가 있을 시 자궁내 성장제한, 임신성 고혈압 등을 초래할 수 있다. 제대-태반 혈관의 내피세포 손상을 유발하는 원인 중 amiloride 유도체들을 중심으로 내피세포에 미치는 amiloride 유도체들의 작용을 밝히고, 세포 내 이온농도 변화와 apoptosis 간의 관계를 규명하고자 하였다. 방 법 : 인간 제대정맥 내피세포는 Clonetics로부터 구입하였으며, 내피세포 성장에 필요한 여러 성장인자가 포함된 배지에서 배양하였다. MTT 방법과 flow cytometry 방법을 이용하여 세포독성 효과 및 apoptosis를 확인하였다. 세포 내 이온농도 변화를 측정하기 위해서는 각각의 목적에 적합한 형광염료들을 세포 내에 부하시켜 놓은 뒤, 형광 현미경과 연결된 영상분석장치를 이용하여 관찰하였다. 결 과 : 1) Amiloride 유도체들은 농도 의존적으로 HUVEC의 사멸을 나타내었으며, 각각의 정도는 HMA($IC_{50}$; $11.2{\mu}M$), MIA($13.6{\mu}M$)>EIPA($30.8{\mu}M$)>>amiloride($106{\mu}M$) 순이었다. 2) 세포주기 분석결과 apoptosis의 특징적인 sub $G_0/G_1$ ploidy peak를 나타냈으며, 이러한 작용은 caspase 억제제에 의해 감소되었다. 3) Annexin-V와 propidium iodide 이중 염색 결과 apoptosis로 진행된 세포의 비율(73.0%)을 대조군(11.3%)에 비해 현저히 증가시켰다. 4) HMA에 의한 apoptosis 효과는 세포외액의 pH를 높이거나, $NH_4Cl$을 투여하여 세포내액의 pH를 높일 경우 크게 증가하였다. 5) HMA는 농도 의존적으로 세포내 주요 이온인 $K^+$$Cl^-$의 세포내 농도를 감소시켰으며, 이러한 효과 역시 세포외액의 pH를 높일수록 현저하게 증가하였다. 결 론 : 이상의 결과들로 미루어 볼 때, HUVEC에서 amiloride 유도체들에 의한 apoptosis 과정에 세포내 주요 이온 농도 감소가 일부 관여하고 있을 것이라 생각된다.

뇌기능 자기공명영상 장치를 이용한 짠맛 자극에 따른 인간 뇌의 반응에 대한 기초 연구 (Salty-taste Activation of Human Brain Disclosed by Gustatory fMRI Study)

  • 김수현;최기승;이현용;신운재;은충기;문치웅
    • Investigative Magnetic Resonance Imaging
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    • 제9권1호
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    • pp.30-35
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    • 2005
  • 목적 : 본 논문은 뇌 기능 자기공명영상(Brain Functional Magnetic Resonance Imaging: Brain fMRI)을 이용하여 짠 맛 자극에 대한 인지활동으로 뇌 신경세포의 활성화에 따른 국소 대사 및 혈류역학적 변화가 일어나는 뇌 영역을 분석 및 가시화함으로써 맛에 대한 뇌 활성화 부위의 기초자료를 마련하고자 하였다. 대상 및 방법 : 건강한 비흡연 남자 12명을 대상으로 1.5T MRI 장치에서 혈액산소수준의존(Blood Oxygen Level Dependent, 이하 BOLD) 방법을 이용한 fMRI 실험을 수행하여 인간의 미각 중 짠맛에 대한 반응을 관찰하였다. 잔 맛의 자극은 $3\%$ 농도의 소금물(NaCl)을 미각 자극기를 이용하여 혀 전체에 자극을 주었다. 미각 자극기인 Auto Syringe Pump는 일정한 자극을 반복적으로 가할 수 있도록 마이크로프로세서를 이용하여 연구실에서 자체 제작되었다. 자극의 패러다임은 5회의 휴식기간과 4회의 자극기간으로 구성되었으며, 자극기간은 15초씩 진행되고 휴식기간은 30초로 하여 각 slice당 42 영상을 연속적으로 획득하였다. 자극에 대해 얻은 fMRI 영상은 SPM99'(Statistical Parametric Mapping, UCL)를 이용하여 분석하였다. 활성화 영상은 EPI 영상과 동일한 부위의 T1 강조영상에 registration 기법을 이용하여 overlapping시켜 활성화 부위의 해부학적 판별을 용이하도록 하였다. 결과 : 농도 $3\%$ 소금물의 짠맛 자극에 대해서 insula, amygdala, frontal opercular taste cortex (OFC), orbitofrontal cortex 영역에서 활성화 영역을 fMRI로 확인하였으며, dorsolateral prefrontal cortex (DLPFC) 영역에서도 유효한 신호를 관찰하였다. 결론 : 본 연구의 결과는 미각의 주요 신경이 뇌의 insula, OFC 그리고 DLPFC 영역에 주로 분포한다는 기존의 결과와 잘 일치하고 있다. 마이크로 프로세서로 동작하는 자동펌프를 미각 자극기로 사용함으로써 미각자극에 대한 뇌의 활성화 영역을 안정되게 관찰할 수 있었다. 본 연구의 결과는 fMRI를 이용한 고차원적 미각작용 과정 연구에 튼튼한 밑거름이 될 것으로 생각된다.

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