The ZIP family zinc transporters support the virulence of Cryptococcus neoformans

Do, E.,Hu, G.,Caza, M. l.,Kronstad, J. W.,Jung, W. H. Informa Healthcare 2016 Medical mycology Vol.54 No.6

<P>Zinc is an essential element in living organisms and a cofactor for various metalloproteins. To disseminate and survive, a pathogenic microbe must obtain zinc from the host, which is an environment with extremely limited zinc availability. In this study, we investigated the roles of the ZIP family zinc transporters Zip1 and Zip2 in the human pathogenic fungus Cryptococcus neoformans. Zip1 and Zip2 are homologous to Zrt1 and Zrt2 of the model fungus, Saccharomyces cerevisiae, respectively. We found that the expression of ZIP1 was regulated by the zinc concentration in the environment. Furthermore, the mutant lacking ZIP1 displayed a severe growth defect under zinc-limited conditions, while the mutant lacking ZIP2 displayed normal growth. Inductively coupled plasma-atomic emission spectroscopy analysis showed that the absence of Zip1 expression significantly reduced total cellular zinc levels relative to that in the wild type, while overexpression of Zip1 was associated with increased cellular zinc levels. These findings suggested that Zip1 plays roles in zinc uptake in C. neoformans. We also constructed a Zip1-FLAG fusion protein and found, by immunofluorescence, not only that the protein was localized to the periphery implying it is a membrane transporter, but also that the protein was N-glycosylated. Furthermore, the mutant lacking ZIP1 showed attenuated virulence in a murine inhalation model of cryptococcosis and reduced survival within murine macrophages. Overall, our data suggest that Zip1 plays essential roles in zinc transport and the virulence of C. neoformans.</P>

Pure titanium 표면에서 calcium phosphate의 핵형성 및 성장

김도균,김교한 大韓齒科器材學會 2000 대한치과재료학회지 Vol.27 No.4

The surfaces of cp titanium specimens were treated by immersion in specific aqueous solutions at 37℃ for 3 days containing phosphate ions and 10 days containing phosphate and calcium ions subsequently (pH 5.8, 7.0, 8.0, respectively) in order to obtain a more biocompatible surface of cp titanium(experimental group 1 and 2). The group 2 specimens treated by above methods and control group without surface treatment were immersed in Hanks' balanced solutions at 37℃ for 30 days to confirm the effectiveness of specific surface treatments and all specimens including group 1 were characterized using scanning electron microscopy(SEM) and x-ray fluorescence spectrometer (XRES). The results were as follows ; 1.In control group only immersed in Hanks' balanced solution for 30 days, the existence of crystallized particles was not evident in SEM. 2.In experimental group 1 treated with phosphate-buffered solutions for 3 days followed by treatment with calcium-phosphate buffered solutions for 10 days, also the existence of crystallized particles was not evident in SEM. 3.In XRES results of experimental group 1, the existence of calcium and phosphate ions was evident in all experimental conditions. In particular, the amount of calcium and phosphate ions were largest in neutral condition, and relative concentrations of Ca/P in acidic condition were 2.06, 1.54 and 1.63 respectively. 4.In experimental group 2 immersed in Hanks' balanced solution for 30 days after treating the specimens with same methods of experimental group 1, dense and numerous multi-layed crystallized particles were found in all experimental conditions in SEM.

The lysine biosynthetic enzyme Lys4 influences iron metabolism, mitochondrial function and virulence in Cryptococcus neoformans

Do, E.,Park, M.,Hu, G.,Caza, M.,Kronstad, J.W.,Jung, W.H. Academic Press 2016 Biochemical and biophysical research communication Vol.477 No.4

The lysine biosynthesis pathway via α-aminoadipate in fungi is considered an attractive target for antifungal drugs due to its absence in mammalian hosts. The iron-sulfur cluster-containing enzyme homoaconitase converts homocitrate to homoisocitrate in the lysine biosynthetic pathway, and is encoded by LYS4 in the model yeast Saccharomyces cerevisiae. In this study, we identified the ortholog of LYS4 in the human fungal pathogen, Cryptococcus neoformans, and found that LYS4 expression is regulated by iron levels and by the iron-related transcription factors Hap3 and HapX. Deletion of the LYS4 gene resulted in lysine auxotrophy suggesting that Lys4 is essential for lysine biosynthesis. Our study also revealed that lysine uptake was mediated by two amino acid permeases, Aap2 and Aap3, and influenced by nitrogen catabolite repression (NCR). Furthermore, the lys4 mutant showed increased sensitivity to oxidative stress, agents that challenge cell wall/membrane integrity, and azole antifungal drugs. We showed that these phenotypes were due in part to impaired mitochondrial function as a result of LYS4 deletion, which we propose disrupts iron homeostasis in the organelle. The combination of defects are consistent with our observation that the lys4 mutant was attenuated virulence in a mouse inhalation model of cryptococcosis.

고등학교 <사회>과 논쟁수업에 관한 연구 : Focusing on the unit "The Development of Democratic Society and Democratic Citizen" from the text of 1st grade students

주도연 이화여자대학교 교육대학원 2003 이화교육논총 Vol.13 No.-

We are living in the society with rapid changes, significant increase in information and innate respect for democracy. Since the members of this society are exposed to various kinds of conflicts resulting from those rapid changes, they are required to have the ability to unravel social conflicts in a rational manner. They are also expected to be able to gather wide range of information and choose suitable information for themselves. In addition, they have to be endowed with the virtues that every member of democratic society should have: conversation and discussion and concession and compromise. Therefore every member of democratic society should be able to sort out necessary knowledge and information, make one's position clear based on rational value system, and mediate interests between oneself and others with willingness to settle problems and will to put one's thought into practice for the purpose of solving problems. That's the very democratic citizenship required by modem society and, if we go further, cultivating those democratic citizen is the direction for as well as objective of the education. Therefore this study is designed to verify the hypothesis that issue-oriented class is more efficient method of teaching to achieve the goals of social study than conventional one by using it for the class as a means of cultivating democratic citizenship according to the consideration that the democratic citizenship is main body for one's will to solve social problems more actively, to define one's position clearly, and to make decision rationally. In the first place, modem society and its issues has been studied. Then the existing theory, conception and theoretical characteristics of issue-oriented class have been examined based on the previous study. Second the groundwork for issue-oriented class has been made after understanding the applicable issues according to each unit of social studies within the context of 7-step curriculum for high school students. Third, 16 areas of controversial issues were presented to the students in order to choose the educational contents based on students' perception with relation to controversial issue class, and their interest, importance, and seriousness have been surveyed. Fourth, for empirical study, the teaching model applying issue-oriented class was given to the first grade students of high school, which means that they are also 10th grade within the context of 7-step curriculum, using the most applicable unit to practice the issue-oriented class, VI. The Development of Democratic Society and Democratic Citizen. However the controversial issue should be selected on the basis of the findings having obtained from previously conducted survey. Fifth, the subjects are the first grade students attending C Girls' High School in Jungang-dong, Gwacheon, which is also the school that the researcher has been working for and 4 of 10 classes were sampled by the researcher randomly. The experiment was performed from October, 2 to October 25, and the issue-oriented class applying PROTON model by Johnson & Johnson and pro-con negotiation model based on Johnson & Johnson's by Ju, Eunok has been given to those 4 classes throughout 5 times. Finally, in order to verify the effect of issue-oriented class, the survey questionnaire was given to all students having participated the experiment before and after the experiment respectively, and the result has been examined thoroughly. As a result it was verified that the issue-oriented class had been more efficient to accomplish the goals of social studies and enhance the academic achievement than conventional one. The analysis methods used here are Paired t test for investigating the degree of democratic citizenship improvement and One-Way MANOVA for examining the correlation among educational effects according to variable factors. SPSS WINDOWS 10.0 has been used for all statistical analyses and the test has been done using 96% confidence level. The results are as follows; First when the comparison was made after the class, all 118 students given the issue-oriented class model have shown significant increase not only in perception of social studies(importance, interest and participation) but also in perception of controversial issues, ability to search for alternatives, procedural principle of rational decision-making procedure and participation in social activities. Second frequency of access to news or newspaper in daily lives, school record, economic status and parents' academic background of a student were compared in order to examine variable factors affecting issue-oriented class. As a result the most influential factors were 'frequency of access to news or newspaper in daily lives' and 'school record of a student'. The educational effect of issue-oriented class had much effect on the students with high marks and those with low grades. The students with little frequency of access to newspapers also have shown much educational effect. Lastly after finishing the issue-oriented class, almost all students showed positive attitude toward the survey questionnaire asking how the students had felt about the class different from previous one, what they could have obtained from the class and what they had wanted from teacher about these kind of class. However this study still has a long way to go. The research period is comparatively short and many other variable factors such as the relation between learning atmosphere and students and interaction with teacher aren't controlled completely. Therefore it is difficult to generalize the results. Consequently the research on more concrete controversial issue-centered education considering Korean classroom situation should be activated, and this would be possible only when supporting policies are made and the teachers have active interest and participation in it. In addition, these research achievements should be reflected in teacher-training course and currently working teacher-training program so that they could help teachers-to-be and currently-working-teachers have a lot of experiences.

지역발전 요인간 관계와 지방정부의 역할

국도형,강병수 충남대학교 지역개발연구소 2000 地域開發論叢 Vol.12 No.-

This thesis aims to analyzed the determinants of regional development which is effecting positively or negatively each other and to find out role of local govenment from be followed result. And, to achieve these objectives, 3 models are adapted. The major result of this study could be summarized as follows. First, At the model of immigrant, employ and school was more effect than others were. Second, At the model of employ, tax and crime were the more important factors than others were. Third, At the model of produce, tax and employ was researched as very important factors. Finally, from the analysis, I suggested role of local government.

불소의 종류 및 도포방법에 따른 치면에의 침착농도 비교

김도훈,박광범,박준봉 慶北大學校 齒科大學 1990 慶北齒大論文集 Vol.7 No.1

치주과적 시술후 빈발되는 병발증중 하나인 지각과민증을 치료하는 방법인 불소도포후 그 종류 및 처리방법에 따라 무기이온의 용출량을 측정함으로써 불소이온이 치근면에 함유되는 양을 역으로 추정하고자 부분적 혹은 완전히 매복된 상, 하악 제3대구치를 이용하여 본실험을 실시하였다. 발거된 치아의 연조직을 제거하여 건조시킨 후 증류수, 2% NaF, 10% SnF_2등의 용액을 국소도포만 시행한 군과 inotophoresis를 병행하여 시행한 군으로 분류한 후 1, 2, 3회 도포를 시행하였다. 무기이온의 용출량을 관찰하고자 처치된 치근면을 노출시킨후 pH5.0으로 적정된 0.5M acetate buffer solution에 2시간 처리하여 각군에서 용출되는 칼슘 및 무기인의 양을 측정하여 상대적으로 치면에 함유된 불소량을 역으로 추정 하였으며 그 결과는 다음과 같다. 대조군, 2% NaF, 10% SnF_2도포군을 비교시 국소도포만 시행한 경우는 도포군사이에 용출량의 유의한 차이를 보였으며, SnF_2군에서 칼슘이온의 용출이 5.69ppm으로 최소였고 NaF군은 이 보다는 효과가 적었으나 대조군에 비해서는 효과가 있었다(p<0.05). Iontophoresis를 병행한 경우도 대조군, NaF군, SnF_2군의 순서로 용출량이 감소되었다(p<0.05). 국소도포만 시행한 경우와 iontophoresis를 병행한 경우에서의 칼슘용출량을 비교해보면 iontophoresis를 병행한 경우가 NaF에서 2.2-11.7배의 감소로 더 우수한 효과를 나타내었으며 NaF보다는 SnF_2가 약 2-4배 정도 더 용출역제효과가 높았다. 도포회수 증가에 따른 칼슘의 용출량은 국소도포만을 시행한 경우 유의성이 없었으나 iontophoresis를 병행한 경우는 대부분에서 유의성 있게 나타났으며(p<0.05) SnF_2의 경우 2회와 3회 시행에서 서로간의 유의성이 없었다(p>0.05). 국소도포만을 시행한 경우 및 iontophoresis를 병행한 경우에서 양자 모두 대조군, 2% NaF, 10% SnF_2의 순서대로 유의성 있게 무기인의 용출이 억제되었다(p<0.05). 국소도포만을 시행한 경우와 iontophoresis를 병행한 경우 무기인의 용출량을 비교해 보면 국소도포만 시행한 군에서 유의성이 있게 감소되었으나(p>0.05) SnF_2의 1회 도포에서 군소판을 시행한 경우에는 iontophoresis가 더 효과가 있었다. 도포회수 증가시 국소도포만을 시행한 모둔 경우 유의성이 없게 나타났으며(p<0.05). iontophoresis를 병행한 후 경우는 SnF_2군은 1회에 비해 2, 3회가 유의성이 있었다(p<0.05). This experiment was designed to measure inversely the amount of fluoride deposited on the partially or completely impacted upper and lower 3rd molars through measuring the amount of the released inorganic ions after application of fluoride, which is one of the therapies for the hypersensitive root that is a frequent complication of periodontal therapies. After debrided and dried, the root surfaces were divided into control group, 2% NaF, 10% SnF_2 topical application group, 2% NaF and 10% SnF_2 iontophoresis group and each of them was treated once, twice, 3 times. To find out the amount of the released inorganic ion the treated root surface was exposed and shaken for 2 hours in the 0.5 M acetate buffer solution (set for pH 5.0) and then the amount of fluoride deposited on the tooth surface was estimated inversely through the measurement of the amount of calcium and phosphorous released. the results were as follows: The amount of calcium released after topical application of fluoride was significantly different among the control, 2% NaF, 10% SnF_2 group. The least amount of them was SnF_2 group, which was 5.69 ppm and that of NaF group was less than SnF_2 group, but more than that of the control group(p<0.05). The same results was found in the iontophoresis groups. When compared the amount of calcium released after topical application and iontophoresis group, the amount of iontophoresis group was more than that of the topical group and the rate of reduction of NaF group was 2.2-11.7 times more than that of the control group. The rate reduction of SnF_2 was 2-4 times more than that of NaF. As the application frequency was increased, the amount of calcium released was not changed significantly in case of topical application, but changed significantly in case of iontophoresis (p<0.05) except twice, 3 times of application(p>.05). In case of phosphorus both topical application and iontophoresis showed significant reducation in the order of control, 2% NaF, 10% SnF2 group(p<0.05). when compared the amount of phosphorous released after topical application and iontophoresis, topical application group showed significant reduction in case of once application of naF, once and 3 times application of SnF2. As the application frequency was increased, the amount of calcium released was not changed significantly in case of topical application, but changed significantly in case of iontophoresis (p<0.05) except twice, 3 times of application(p>0.05). In case of phosphorous both topical application and iontophoresis showed significant reduction in the order of control, 2% NaF, 10% SnF_2 group(p<0.05). When compared the amount of phosphorous released after topical application and iontophoresis, topical application group showed significant reduction in case of once application of NaF, once and 3 times application of SnF2. As the application frequency was increased, the amount of phosphorous released was not changed significantly in case of topical application and significant difference was found between once and twice, 3 times application in case of iontophoresis. J. Kyungpook Univ. Sch. Dent. Vol.7,No.1,169∼181,1990

석회유담즙증 1예

이지아,김도영,정혜경,문일환,신수연,곽재진 梨花女子大學校 醫科大學 醫科學硏究所 2003 EMJ (Ewha medical journal) Vol.26 No.1

Milk of calcium bile or limy bile is a rare disorder in which the gallbladder lumen is filled with a thick, paste-like, radio-opaque material. Churchman first reported a case of curious deposition of calcium salts within the gallbladder in 1911. Volkmann first used the term Kalkmilchgalle or "milk of calcium bile" in 1926. The radio-opaque material is almost entirely composed of calcium carbonate by weight. The mechanisms by which bile turns limy and radio-opaque or the time required for this biochemical alteration to occur are not well understood. The limy bile is found mostly in a gallbladder complicated by cholecystitis. Recently, we experienced a 33 year old woman who had a milk of calcium bile in the gallbladder lumen. We report this case with a review of literature.

配分交通量 豫測時 Link 走行時間設定에 關한 硏究

李周桓,金度坤,金大雄 嶺南大學校 工業技術硏究所 1998 工業技術硏究所論文集 Vol.26 No.2

Judging form the results of estimating segment volumes, the applicability more differs with how link performance functions are set up rather than which traffic assignment model is used So, the purpose of this study is to establish link performance functions which fit the current transportation network in our country. The result of this study can be summarized as follows; ●Estimated parameter by total lane is α=2.0, β=2.76, but R ²=0.55. Estimated parameter by each lane is that R ²is over 90.0%. So, it is reasonable what Parameter of BPR function is used with each lane. ●When the traffic assignment, if BPR function is used as performance function must apply to each road type.

전염성 단핵구증 1예

이종수,김도영 梨花女子大學校 醫科大學 醫科學硏究所 2001 EMJ (Ewha medical journal) Vol.24 No.3

Infectious mononucleosis is an acute lymphoproliferative disease that is most common in children and young adults and is caused by Epstein-Barr virus. Characteristic clinical feastures include : 1) fever, sore throat, and lymphadenopathy ; 2) an associated absolute lymphocytosis greater than 50%, of which at least 10% are atypical lymphocytes in the peripheral blood ; 3) development of transient heterophil and persistent antibody responses against Epstein-Barr virus ; and 4) abnormal liver function tests. The most prevalent age of infectious mononucleosis in Korea was less than 5 years old and it has been very rare in adulthood. However, recently in Korea, possibly due to the increasing number of people who are non-immune to Epstein-Barr virus, the age range seems to be increasing from young childhood to over 10 years old and even to adulthood. We present a 19-year-old man who showed typical clinical features of infectious mononucleosis.

췌장의 점액성 낭선암 1예

송현주,김도영,정혜경,남승현,문일환,구혜수 梨花女子大學校 醫科大學 醫科學硏究所 2002 EMJ (Ewha medical journal) Vol.25 No.2

Nowadays increasing use of abdominal ultrasound in routine check-up may increase the detection rate asymtomatic cystic lesions of pancreas. Even through the majority of the cystic lesions of pancreas is pseudocyst, about 10-15% of those lesions are caused by pancreatic cystic tumor. In the pancreatic cystic tumor, especially, mucinous cystic tumor should be exicised due to its malignant potential, while the pancreatic pseudocyst or serous cystic tumon can be observed for a period or treated medically. Several clinical, radiological, biochemical and pathologic guidelines have been developed in order to distinguish among them. Among pancreatic cystic tumors, mucinous cystic adenocarcinoma is very rare and accounts for only 1% of all pancreatic neoplasms. Unlike extremely poor prognosis of pancreatic adenocarcinoma, mucinous cystic adenocarcinoma has an indolent course and shows a good prognosis after its curative resection. Recently we experienced a 69-year-old woman who had a mucinous cystic adenocarcinoma of the pancreas. We report this case with a review of literature.