• 한국해양학회지
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• 제14권1호
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• pp.15-25
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• 1979

A study on field bioassay test using four species of commercially important shellfish was carried out to assess the effect of pollutants and determine the extent of marine environmental pollution of the Masan Bay from 9 to 15 August 1978. Water quality analysis and planktological examination of sea water were made during the experiment and the examination gave the following results. The water temperature was so high at 31.7$^{\circ}C$ in maximum and rather subject to change on weather condition of the land than on the effect of the water mass from outer bay. The range of DO,COD and SS at the stations were 0.3-7.08cc/l, 0.07-3.31ppm and 5.5-117ppm, respectively with the high values of COD and SS at the stations 7 and 1. The concentrations of the dissolved inorganic nitrogen in sea water, NH$\sub$4/-N, NO$\sub$2/-N, NO$\sub$3/-N, and PO$\sub$4/-P were 18.90-99.80, 2.48- 19.60, 13.00-39.00 and 1.04-14.0$\mu\textrm{g}$ at/l, respectively with decrease of their values in the outer part of the Bay. The high values mentioned above were caused by the sewage and industrial activities. The effects of organic waste are increased oxygen demand, nutrient concentration, turbidity and a higher input of pathogens, leading to structural changes in the marine ecosystems and to a considerable hazard to public health. The percentage composition of phytoplankton standing crop between diatom and dinoflagellate was characterized by making a difference between the two groups in respect of location: a decrease of diatom and a increase of dinoflagellate in numerical abundance toward inner part from outer part of the bay. Namely phytoplankton organisms were composed of 80% of diatom and 20% of dinoflagellate in outer bay, on the contrary, only 4% of diatom and 96% of dinoflagellate occupied by 94% of prorocentrum micans known as tolerant species to polluted reaas in the inner bay. On the occurrence and composition of zooplankton, there are two significant communities in the bay:one is characterized by the predominance of Oithona nana and the other by Favella sp They were composed of a range from 84% to 90% of the total organisms and monotonously constituted of themselves only at most inner station 3 even small numbers. From the results mentioned above, Oithona nana, Favella and prorocentrum micans recommed themselves as valuable indicators for judging the extent of the marine pollution.During the period of the biossays Mytilus edulis showed the highest mortality and Tapes japonica the lowest one between the four test species. The highest death rate by stations was found at most inner stations 3'and 4near Masan Free Export Zone with the most sensitive response and the lowest one occured at outer station 13 where no death specimen of oyster and arkshell was found during the whole test period.As for mussel,85 percent death rate appeared after 72 hours and 100percent rate after 120hours at station 4. It was found that the significant high mortality of the test shellfish mentioned above was caused by severe pollution with mainly organic pollutants from domestic sewage and industrial wastes from the results of too much higher concentrations of dissolved inorganic nitrogen especially ammonia-N,COD,SS and lack of dissolved oxygen,and furthermore occurrence and abundance composition of Prorcentrum,Favella and Oithona nana by stations, valuable indicator species of coastal pollution by orgnic and boilogical pollutants.

• 대한한방내과학회지
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• 제36권4호
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• pp.547-561
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• 2015

Objectives In this study, we divided Korean asthma patients into excess syndrome or deficiency syndrome groups according to clinical phenotype. Genetic analysis was conducted to investigate the association of exonic SNPs in the CD46 gene polymorphism with the clinical phenotype based on the differentiation syndrome of the bronchial asthma patients.Methods There were 95 healthy patients (control group) and 53 asthma patients. (The deficiency syndrome group included 24 and the excess syndrome group 29). We searched the exonic areas of the CD46 gene in the NCBI website SNPs with <0.01 minor allele frequency (MAF) and <0.01 heterozygosity. We finally selected two SNPs: rs138843816, Ser13Phe and rs7144, 3’-UTR. Hardy-Weinberg equilibrium was calculated using SNPStats.Results There were significant differences in the codominant 1 model and the dominant model between the healthy group and the asthma group. There were significant differences between deficiency syndrome group and the excess syndrome group in the genotype frequencies and in the codominant 1 model, the dominant model, and the log-additive model. The allele frequency of rs7144C showed a significant difference between the deficiency syndrome group and the excess syndrome group. Two-SNP haplotype analysis showed a significant difference in frequency in the deficiency syndrome group and in the excess syndrome group. There were significant differences between the healthy group and the excess syndrome group in the codominant 1 model, the dominant model, and the log-additive model. The frequency of the rs7144 C allele exhibited a significant difference in the demonstration. SNP haplotype analysis between the healthy group and the excess syndrome group showed a significant difference in the frequency of the CT haplotype and the CC haplotype.Conclusions The results indicate that two CD46 SNPs (rs138843816, Ser13Phe and rs7144, 3′–UTR) might be associated with the symptomatic excess syndrome in Korean asthma patients.

• Journal of Applied Biological Chemistry
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• 제63권1호
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• pp.95-101
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• 2020

건선(psoriasis)은 인체 피부조직 중 표피의 과증식 및 다양한 크기의 홍반, 인설 등이 동반되는 난치성 자가면역 피부질환이다. 건선 피부염 발병 기작은 명확히 규명되지 않았으나 각질 형성세포의 과분화 과정에 관여하는 염증성 cytokine과 Th17 세포를 포함한 면역세포를 염증부위로 유인하는 chemokine (C-C motif) ligand 20 (CCL20)이 발병과정에 관여하는 것으로 알려진다. 따라서 건선치료에 효과적인 천연 소재를 발굴하기 위해 예로부터 항염증 활성이 알려진 익지인(Alpiniaoxyphylla Miquel)의 유효성분인 yakuchinone-A의 건선 피부염 개선효과를 연구하였다. 먼저 CCK-8 assay 통해 human keratinocyte (HaCaT) 세포에 tumor necrosis factor-alpha (TNF-α)와 yakuchinone-A를 동시 처리하여 세포독성을 관찰한 결과, yakuchinone-A는 10 ㎍/mL까지 세포독성이 관찰되지 않았다. TNF-α를 HaCaT 세포에 처리하여 염증을 유발한 후 yakuchinone-A를 농도별로 처리한 결과 IL-6, IL-8, TNF-α 등 건선 피부염 유발 cytokine의 mRNA 발현이 각각 61.4±7.5, 23.6±1.5, 46.0±4.8% 수준으로 감소하였고, Th17 세포를 유인하는 chemokine인 CCL20 또한 yakuchinone-A에 의해 유의적으로 억제되었다. 또한 CCL20 발현에 관여하는 NF-κB/IκB pathway에서 IκB 인산화 및 STAT3 인산화가 yakuchinone-A에 의해 79.1±5.0, 80.8±2.3% 수준만큼 농도 의존적으로 억제되었다. 마지막으로 Th17 세포에 의해 분비되는 IL-17A에 의해 활성화된 HaCaT 세포에 yakuchinone-A를 처리한 결과, CCL20 mRNA발현이 농도의존적으로 감소하였다. 이러한 결과들을 토대로 yakuchinone-A는 건선 피부염 개선 활성을 가지며, 향후 새로운 건선 피부염 개선 소재로 개발될 수 있을 것으로 기대된다.

• 대한두경부종양학회지
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• 제14권2호
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• pp.156-163
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• 1998

Background & Objectives: Frameless fractionated stereotactic radiotherapy(FFSRT) is a modification of stereotactic radiosurgery(SRS) with radiobiologic advantage of fractionation without losing mechanical accuracy of SRS. Local recurrence of head and neck cancer at or near skull base benefit from reirradiation. Main barrier to successful palliation is dose limitation secondary to normal tissue tolerance. We try to evaluate the efficacy and safety of FFSRT as a new modality of reirradaton in these challenging patients. Materials & Methods: Seven patients with recurrent head & neck cancer involving at or near skull base received FFSRT from September 1995 to November 1997. Six patients with nasopharyngeal cancer had received induction chemotherapy and curative radiation therapy. One patient with maxillary sinus cancer had received total maxillectomy and postoperative radiation therapy as a initial treatment. Follow-up ranged from 11 to 32 months with median of 24 months. Three of 7 patients received hyperfractionated radiation therapy(1.1-1.2Gy/fraction, bid, total 19.8-24Gy) just before FFSRT. All patients received FFSRT(3-5Gy/fraction, total 15-30Gy/5-10fractions). Chemotherapy(cis-platin $100mg/m^2$) were given concurrently with FFSRT in four patients. Second course of FFSRT were given in 4 patients with progression or recurrence after initial FFSRT. Because IF(irregularity factor; ratio of surface area of target to the surface area of sphere with same volume as a target) is too big to use conventional stereotactic RT using multiple arc method for protection of radiation damage to critical normal tissue, all patients received FFSRT with conformal method using irregular static ports. Results: Five of 7 patients showed complete remission in follow-up CT &/or MRI. Three of these five patients who developed marginal, in-field, and out-field recurrences, respectively. Another one of complete responders has been dead of G-I bleeding without evidence of local recurrence. One partial responder who showed progressive disease 15 months after initial FFSRT has received additional FFSRT, and then he is well-being with symptomatic improvement. One minmal responder who showed progression of locoregional disease 9 months after $1^{st}$ FFSRT has received 2nd FFSRT, and then he is alive with stable disease. Five of 7 case had showed direct invasion to skull base and had complaint headache and various symptoms of cranial nerve involvement. Four of these five case showed improvement of neurologic symptoms after FFSRT. No significant neurologic complicaltion related to FFSRT was observed during follow-up periods. Tumor volumes were ranged from 3.9 to 50.7 cc and surface area ranged from 16.1 to $114.9cm^2$. IF ranged from 1.21 to 1.74. The average ratio of volume of prescription isodose shell to target volume was 1.02 that indicated the improvement of target coverage and dose distribution with FFSRT with conformal method compared to target coverage with FFSRT with multiple arc method. Conclusion: Our initial experience suggests that FFSRT with conformal method was relatively effective and safe modality in the treatment of recurrent head and neck cancer involving at or near skull base. Treatment benefit included good palliation of symptoms and reasonable radiographic response. However, more experience and additional follow-up are needed to better assess its ultimate role in treating these challenging patients.

• 생물환경조절학회지
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• 제15권2호
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• pp.125-137
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• 2006

본 연구에서는 큰느타리버섯 재배사의 환경조절을 최적화하고 시스템 설계에 대한 기초자료를 얻기 위하여 진주인근에 위치한 샌드위치패널을 이용한 영구형 재배사 2동을 대상으로 2003년 11월부터 2005년 10월까지 재배사 내부에서 측정한 환경인자들을 중심으로 검토하였다. 실험지역의 외기온은 평년의 것과 대체로 비슷한 경향을 보였다. 시스템 변경전의 경우, 동절기에는 전체적으로 설정온도보다 낮게 유지되었고, 또 최상부와 최하부의 최대온도 편차도 $5.1^{\circ}C$ 정도로 상층이 가장 높게 나타났다. 그러나 시스템의 변경 후의 경우, 난방시 대체로 설정온도 범위에서 조절되는 경향을 보였고, 공기정체나 온도층의 역전현상이 나타나지 않았다. 상대습도는 시스템 변경 후, $80{\sim}100%$ 정도의 범위로서 권장상대습도 범위에 있었다. 전체 재배기간동안 탄산가스 농도는 $400{\sim}3,300mg{\cdot}L^{-1}$ 정도의 범위에 있었다. 조도는 권장조도보다 전반적으로 낮게 유지되고 있음을 알 수 있었고, 산도는 대체로 일정하게 유지되었다. 수확량은 전체적으로 일정하지 않았고, 포기재배의 경우가 상대적으로 등외품이 적었으며, 증수 효과도 있었다. 전력소비량은 계절별로 일정한 경향이 있음을 알 수 있었고, 하절기보다 동절기에 전력소비량이 현저히 많은 것을 확인 할 수 있었다.

• Tuberculosis and Respiratory Diseases
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• 제53권2호
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• pp.113-126
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• 2002

연구배경 : 폐암의 80-90%는 흡연과 관계가 있으나 흡연자의 일부에서만 폐암이 발생하는 현상은 개체의 유전적 소인이 폐암발생을 결정하는 주요 요인임을 시사한다. 저자들은 한국인에서 DNA 회복 유전자인 XPC 유전자의 codon 499와 codon 939 다형성 그리고 intron 9에 존재하는 poly(AT) 삽입/결손 (PAT) 다형성에 따른 폐암의 위험도를 조사하였다. 방 법 :1998년 1월부터 1998년 12월까지 경북대학교병원 내과에서 병리학적으로 폐암으로 확진된 남자 폐암환자 219명을 대상으로 하였으며 악성종양으로 진단받은 과거력이 있는 사람은 제외하였다. 대조군은 1998년 1월부터 1998년 12월까지 경북대학교병원 건강검진센터를 방문한 40세 이상의 검진자들을 대상으로 하였으며 호흡기질환이나 악성종양이 있는 경우는 제외하였다. 대상인의 나이, 성, 흡연력, 과거력 등은 면접이나 병력지를 통해 얻었으며, 시료는 전혈 5cc에서 DNA를 추출하고 PCR 혹은 PCR-RFLP법을 통해 XPC 유전자의 다형성을 조사하였다. 결 과: 조사한 3부위의 XPC 유전자의 유의한 관계가 없었으며 연령, 흡연력, 흡연 인-년등으로 구분한 경우에도 다형성에 따른 폐암의 위험도는 유의한 차이가 없었다. 폐암의 조직형을 구분하여 비교한 경우에도 XPC 유전자의 다형성과 폐암의 위험도는 유의한 관계가 없었다. XPC 유전자의 Va1499Ala, PAT, Lys939Gln 다형성은 다형성간에 연관비평형 (lingkage disequilibrium) 있었으며, 특히 PAT 다형성과 Lys939Gln 다형성은 kappa 치가 0.87로 높았다. XPC 유전자의 3부위다형성의 haplotype도 폐암과 유의한 관계가 없었으며, 연력, 흡연력, 흡연 안-년, 조직형을 구분한 경우에도 haplotype에 따른 폐암의 위험도는 유의차이가 없었다. 결 론: 한국인에서 XPC 유전자의 codon 499와 codon 939 다형성과 PAT 다형성은 폐암의 위험도를 결정하는 주요 인자는 아닌 것으로 생각된다.

• Tuberculosis and Respiratory Diseases
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• 제60권1호
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• pp.65-71
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• 2006

서론 : 대량객혈은 치료가 이루어 지지 않을 경우, 50% 이상의 사망률을 보이는 호흡기 영역의 가장 위급한 응급상황의 하나이며 여러 원인에 의해 발생 될 수 있다. 1973년 레미 등에 의해 처음 보고된 이후로 기관지동맥 색전술은 대량의 재발성 객혈의 치료로 확립되어 그 효과가 입증 되었다. 그러나 기관지동맥 색전술의 재발률은 10~52%로 보고되어 객혈의 재발을 예측 할 수 있는 위험 요소들에 대한 연구가 필요하다. 재료 및 방법 : 2000년 1월부터 2005년 1월까지 세브란스병원에 100 cc 이상의 대량 객혈로 내원하여 기관지동맥 색전술을 시행 받은 66명 환자들을 대상으로 하여 기관지동맥 색전술 후 재발의 빈도와 재발과 관련이 있는 위험 요인에 대해 분석하였다. 결과 : 5년 간 기관지동맥 색전술을 시행 받은 환자는 75명이었고, 장기간 추적관찰이 되어 결과 분석이 가능했던 환자는 66명이었다. 이들의 평균 나이는 $54.9{\pm}15.9$세이었고, 남자가 48명, 여자가 18명이었다. 원인 질환은 결핵 20명, 기관지확장증 및 기타 양성질환 23명, 악성 종양 7명이었고, 평균 20.4개월 간의 추적 관찰 기간 동안 23명(34.9%)에서 치료가 필요한 대량 객혈이 재발되었다. 환자의 성별과 나이, 이전에 객혈로 시술 받은 과거력, 객혈의 원인 질환, 분포 혈관의 수 등은 대량 객혈의 재발과 유의한 관계가 없었으나, 병변의 양측성, 흉막 비후, 객혈의 양은 유의한 인자로 관찰되었고, 로그 회귀분석 결과에서도 동일하였다. 결론 : 기관지동맥 색전술을 시행한 후 객혈의 재발을 예측할 수 있는 위험 인자로 흉막 비후, 병변의 양측성, 객혈의 양이 중요하게 작용하며, 이에 대한 대규모 임상 연구가 필요하다.

• 한국균학회지
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• 제3권1호
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• pp.1-19
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• 1975

Since the importance of casing in fruit body formation of Agaricus bisporus has been emphasized, physico-chemical characteristics of casing materials were discussed by many workers and a mixture of peat and mineral soil as proper casing material has been adopted in many of mushroom growing countries. Because of limited resources of peat in Korea, it is necessary to find practical performance and substitutional materials for casing. The effect of casing on mycelial growth and mushroom yield of A. bisporus varied with materials, its combination and practices etc. The experiments to be discussed in this paper are concerned with pH and Ca of casing material which influence A bisporus, and changes of physico-chemical characteristics with mixing ratio of casing materials and its effect on A. bisporus. The optimum range of moisture content of each material, management of watering and application of physico-chemical characteristics casing materials was also investigated and re-use of weathered spent compost for casing material was described. 1. The effect of calcium on mycelial growth of A. bisporus at various pH in Halbschalentest showed different results with calcium sources. Best results were obtained around neutrality and fresh weight of fruit bodies grown in the range of pH 7 to 8 was highest among the tested levels. 2. Available moisture, pore space, organic matter, cation exchangeable capacity and exchangeable cation was increased by an increase of mixing ratio of peat in casing materials, while an adverse effect was obtained by addition of sand. 3. Mycelial growth on clay loam was more rapid at a lower bulk density of 0.75g/cc and at 20% moisture content on a dry weight basis at the same bulk density. 4. Mixing ratio of casing materials, 60 to 80 per cent by volume of peat mixed with 20 to 40 per cent of clay loam produced the highest yield of fresh fruit bodies and sand the lowest. However, per cent of open cap was highest in peat and lowest in sand. 5. Days required for fruit body initiation was shortened in mixtures of peat and clay loam by one to three days compared with other materials and the formation of flushes was clear. 6. The effect of some physico-chemical characteristics of casing materials on the fresh weight of fruit bodies were estimated by a multiple regression equation; Y=-923.86+$8.18X_1+8.04X_2+7.90X_3+0.12X_4+2.03X_5-0.82X_6-0.54X_7$ where $X_1,X_2,X_3,X_4,X_5,X_6,X_7$ are sand, silt, clay, available moistuer, porosity, organic matter and exchangeable cation respectively. The productivity of certain casing material could be predicted from this equation. 7. Fresh weight of fruit bodies was positively correlated with porosity exchangeable cation, organic matter, available moisture, silt and clay of materials; while sand was negatively correlated. On the contrary, sand was the unique factor reducing per cent of open cap. 8. Distribution of three phases of high productive casing material was concentrated in the range of 10 to 30 per cent solids, 15 to 30 per cent liquids, and 50 to 60 per cent in air volume. 9. Fresh weight of fruit bodies from peat was not affected with heavy watering but in clay loam and sandy loam severe crop losses occurred. Fresh weight of individual fruit was increased and open caps were decreased with heavy watering but light watering resulted in adverse effects: its effect was especially great in peat. 10. Optimum range of moisture content by weight on a dry basis was different with each casing material. To maintain optimum moisture content concerned with yield of fruit bodies and open cap, sandy loam and peat mixtures required daily watering of 0.6, 0.6 to 1. 2 and 1.2 to 2.4 liters per $3.3m^2$ of bed area, respectively. 11. Maximum yield of fruit body was recorded in the range of pF 2. 0 to 2. 5 of casing materials if organic matter content was below 4.2 per cent and in pF 1. 3 to 1.8 if above 7.1%. 12. pF curve of a certain casing material could be draws from moisture content at various pF values by multiple regression equations provided texture, organic matter and calcium of the casing material are given. Optimum moisture range of the casing materials also could be estimated by the equation. 13. It was possible to improve the phyico-chemical characteristics of clay loam and sandy loam by addition of weathered spent compost although the effect was less than in the case of peat. Fresh weight of fruit bodies wsa increased by addition of weathered spent compost but its effect was not as remarkable as peat. Accordingly, further studies will be required.

• 암석학회지
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• 제21권4호
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• pp.385-396
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• 2012

우리나라에서 가장 큰 화산섬인 제주도에는 약 360여 개의 단성화산체가 분포되어 있다고 알려져 있으나, 본 연구를 통해 기존에 일려진 것보다 100여 개가 더 많은 총 455개의 단성화산체가 분포하고 있음을 확인하였다. 총 455개의 단성화산체를 형태학적으로 분석해 본 결과, 분석구가 373개로 전체의 82.0%를 차지하여 가장 높은 비율로 나타나며, 분석구 외에도 정상부가 뾰족한 형태이면서 용암으로 구성된 것이 9개(2.0%), 순상화산체가 27개(5.9%), 응회환이 17개(3.7%), 응회구가 3개(0.7%), 마르가 1개(0.2%), 용암돔이 25개(5.5%)가 분포하고 있다. 또한 이들 중 알오름의 형태로 나타나는 것이 15개가 있다. 단성화산체의 지역별 분포를 살펴보면 전체적으로 제주도의 서쪽에 비해 동쪽에 더 우세하게 분포하고 있음을 알 수 있다. 또한 강수량과 같은 풍화 요인에 의해 분석구의 형태가 영향을 받는다면, 강수량이 월등히 더 많은 남부 지역에 한 방향으로 터진 말발굽형 화구를 가진 분석구나 초승달형 분석구, 불규칙한 형태의 분석구 등이 더 많이 분포해야 할 것이다. 그러나 실제 제주도에서는 오히려 강수량이 더 적은 북부 지역에 이러한 분석구들이 더 많이 분포하는 것으로 나타나, 제주도의 남북 간의 기후적인 요소의 차이가 분석구의 형태나 분포에 크게 영향을 끼친 것은 아니라고 생각된다. 단성화산체 중 응회환, 응회구와 마르는 주로 제주화산섬의 지하 또는 해안가의 저지대에 위치하며, 분석구는 대부분이 해안에서 떨어진 섬의 내륙부에 위치한다. 이는 제주도 단성화산체를 형성한 화산활동이 물(지하수 또는 얕은 바닷물)과의 접촉 유무에 따라 수성화산활동(수증기마그마분화)을 하거나, 마그마성화산활동(스트롬볼리안분화 혹은 하와이안분화)을 한 것임을 알 수 있다. 또한 이들 단성화산체의 고도별 분포를 살펴보면 고도 300 m 이하의 해안저지대에 253개(55.6%), 고도 300~600 m의 중산간지대에 110개(24.2%), 600 m 이상의 산악지대에 92개(20.2%)가 분포하고 있어 과반수 이상이 해안저지대에 분포하고 있음을 알 수 있다. 제주화산섬에 분포하는 단성화산체들은 응력장 안에서 생긴 단층이나 틈을 따라서 틈새 분출을 통해 선상으로 배열되어 나타나는 것과 이러한 틈새와는 무관하게 독립된 단일 화구를 통한 중심 분출을 통해 생성된 것이 함께 나타남을 알 수 있다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.37-37
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• 2003

We have shown the $Ca^{2+}$-activated chloride current is present in cardiac myocyte in rabbit pulmonary vein (Kim et al., 2002). This current amplitude was increased as [N $a^{+}$]$_{i}$ was increased and we suggested this chloride current may be involve in the spontaneous action potential frequency change. Since this current is activated by the increase of intracellular $Ca^{2+}$, we would like to test what is the inducer of the increase of [C $a^{2+}$]$_{i}$ between a L-type $Ca^{2+}$-current or a reverse mode of N $a^{+}$-C $a^{2+}$ exchange current. White rabbit (1.5 kg) was used and anesthetized with Ketamin (100 mg/kg). Pulmonary vein (PV) was isolated and sleeve area between left atrium and PV was dissected. Using collagenase (Worthington 0.7 mg/cc), single cardiac myocytes were isolated. In the presence of 15 mM of N $a^{＋}$, three steps of voltage pulses were applied (holding potential : -40 ㎷, -80 ㎷ for 50 msec, 30 ㎷ for 5 msec, 10 ㎷ steps from -70 ㎷ to 60 ㎷). The inward and outward tail current was activated after brief 5 msec prepulse. The outward tail current was blocked by the removal of extracellular chloride substituted by glucuronic acid or by a chloride channel blocker, 5 mM 9-AC. But the inward tail current was still remained even though the amplitude was decreased. The reversal potentials were changed to the direction of the change of chloride equilibrium potential ( $E_{Cl}$ ) but the shift of equilibrium potential was not enough to match to the theoretical equilibrium potential shift. In the presence of L-type $Ca^{2+}$ channel blocker, nifedipine 1 uM, inward tail currents were greatly reduced but the outward current tail currents were still remained. In the presence of N $a^{+}$-C $a^{2+}$ exchange current blocker, 10 uM KB-R7943, the inward and outward tail currents were blocked almost completely. We tried to test the $Ca^{2+}$sensitivity of the chloride current with various [C $a^{2+}$]$_{i}$ in pipette solution from 100 nM to 1 uM but we failed to activate $Ca^{2＋}$-activated chloride currents even though the cell became contracted in the presence of 1 uM $Ca^{2+}$. From these results, we could conclude that the increase of [C $a^{2+}$]$_{i}$ to activate the outward $Ca^{2+}$-activated chloride current was mainly induced by the activation of the reverse mode of N $a^{+}$-C $a^{2+}$ exchanger, But for the increase of [C $a^{2+}$]$_{i}$ to activate the inward tail current, L-type $Ca^{2+}$ current may be the major provoking current. Since the cytosolic increase of [C $a^{2+}$]$_{i}$ through pipette solution have failed to activate $Ca^{2+}$-activated chloride current, this chloride current may have very low $Ca^{2+}$ sensitivity or a comparmental increase $Ca^{2+}$ such as in subsarcolemmal space may activate the chloride current. Since there are several reports and models that the increase of $Ca^{2+}$ in subsarcolemmal space would be over several to tens of uM, both possibility may be valid together.uM, both possibility may be valid together.