• 한국물환경학회지
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• 제34권4호
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• pp.375-381
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• 2018

The monitoring of phytoplankton biomass and community structure is essential as a first step to control the harmful cyanobacterial blooms in freshwater systems, such as seen in rivers and lakes, due to the process of eutrophication and climate change. In order to quantify the biomass of phytoplankton with a wide range in size and shape, the measurement of cell biovolume along with cell density is required for a comprehensive review on this issue. However, most routine monitoring programs preserve the gathered phytoplankton samples before analysis using chemical additives, because of the constraint of time and the number of samples. The purpose of this study was to investigate the cell biovolume change characteristics of six cyanobacterial species, which are common bloom-causing cyanobacteria in the Nakdong River, after the preservation with Lugol's iodine solution. All species showed a statistically significant difference after the addition of Lugol's iodine solution compared to the live cell biovolume, and the cell biovolume decreased to the level of 34.0 ~ 56.3 % at maximum in each species after the preservation. The nonlinear regression models for determining the shrinkage ratio by a preservation period were derived by using the cell biovolume measured until 180 days preservation of each target species, and the equation to convert the cell biovolume measured after preservation for a certain period to the cell biovolume of viable cell was derived using that formula. The conversion equation derived from this study can be used to estimate the actual cell biovolume in the natural environment at the time of sampling, by using the measured biovolume after the preservation in the phytoplankton monitoring. Moreover this is expected to contribute to the final interpretation of the water quality and aquatic ecosystem impacts due to the cyanobacterial blooms.

• Journal of Microbiology and Biotechnology
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• 제23권3호
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• pp.289-296
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• 2013

Cryptomonads are unicellular, biflagellate algae. Generally, cryptomonad cells cannot be preserved well because of their fragile nature, and an improved methodology should be developed to identify cryptomonads from natural habitats. In this study, we tried using several cytological fixatives, including glutaraldehyde, formaldehyde, and their combinations to preserve field samples collected from various waters, and the currently used fixative, Lugol's solution was tested for comparison. Results showed that among the fixatives tested, glutaraldehyde preserved the samples best, and the optimal concentration of glutaraldehyde was 2%. The cell morphology was well preserved by glutaraldehyde. Cells kept their original color, volume, and shape, and important taxonomic features such as furrow/gullet complex, ejectosomes, as well as flagella could be observed clearly, whereas these organelles frequently disappeared in Lugol's solution preserved samples. The osmotic adjustments and buffers tested could not preserve cell density significantly higher. Statistical calculation showed the cell density in the samples preserved by 2% glutaraldehyde remained stable after 43 days of the fixation procedure. In addition, DNA was extracted from glutaraldehyde preserved samples by grinding with liquid nitrogen and the 18S rDNA sequence was amplified by PCR. The sequence was virtually identical to the reference sequence, and phylogenetic analyses showed very close relationship between it and sequences from the same organism. To sum up, the present study demonstrated that 2% unbuffered glutaraldehyde, without osmotic adjustments, can preserve cryptomonads cells for identification, in terms of both light microscopy and phylogenetic analyses based on DNA sequences.

• 한국어병학회지
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• 제19권1호
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• pp.7-15
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• 2006

육상수조에 양식중인 폐사가 발생하는 숭어 (Mugil cephalus)를 조사한 결과 아가미와 지느러미에 Amyloodinium sp.의 감염이 확인되었다. 아가미의 무염색표본을 검경하면 충체는 불투명한 원형 또는 난원형으로 중심부에 밝게 보이는 핵을 가지고 있는데, Lugol 액 이나 Diff-Quick III액을 적하하여 충체는 각각 검은색과 청색으로 염색된다. 또 충체를 May-Grunwald Giemsa염색하면 세포질의 주변부는 과립성의 호산성이지만 가운데 부위는 과립성의 호염기성으로 염색되는데, 도은염색에서 세포질의 과립은 음성, 중심부의 과립은 양성이었으며, 도은 양성과립은 Lugol 액에 갈색으로 염색되었다. 분리한 충체를 여과멸균해수에 넣어 20℃에서 배양하였을 엷은 이중막인 시스트막이 형성되면서 2분열을 일으켜 최종적으로 시스트막이 파열되면서 수많은 dinospores가 방출되었다. 병리조직학적으로는 아가미 상피세포의 증생으로 인한 새변의 유착, 곤봉화 및 변형이 일어나 병어는 호흡곤란을 일으키는 것으로 판단되었다.

• Korean Chemical Engineering Research
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• 제54권1호
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• pp.140-144
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• 2016

본 연구에서는 극지 연구소로부터 분양 받은 Arthrobacter sp. PAMC 27388 균주에서 생산되는 아밀라아제(amylase)를 물리적 요인(physical factor)들의 변화를 통하여 생산배지 최적화를 수행하였다. 한천 배지 상에서 lugol solution을 이용한 클린환의 확인을 통하여 아밀라아제가 생산됨을 확인하였으며, 16S rDNA를 이용하여 동정한 결과 Arthrobacter sp. 임을 확인할 수 있었다. 최적화 이전의 아밀라아제 생산량은 1.66 mU/L로 확인되었다. 최적화 결과, 2.49 mL의 접종부피, pH 6.85, 42.87 mL의 배지 부피의 조건에서 가장 많은 양의 아밀라아제가 생산될 것으로 예상되었으며, 생산량은 2.84 mU/L로 예상되었다. 확인 실험을 통하여 최적화 이전과 비교하여 생산량이 약 150% 증가한 2.50 mU/L의 아밀라아제가 생산됨을 확인할 수 있었다.

• 한국물환경학회지
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• 제34권2호
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• pp.210-215
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• 2018

It is difficult to count colonial cyanobacteria Microcystis cells since the thickness of colonies is constrained by amorphous mucilage, making it impossible to estimate the number of cells. Disaggregation of Microcystis colonies into single cell is needed to improve the accuracy and precision of cell density estimation of naturally collected samples. Uultrasonic treatment method is commonly used owing to the simplicity and immediacy of the procedure. However, amplitude, frequency, and duration of ultrasonic treatment also cause cell loss during the experiment. Optimal ultrasonic treatment has not been standardized yet. Therefore, the objective of this study was to investigate optimal ultrasonic treatment by analyzing cell density and colony numbers. We collected colonial Microcystis from Changnyeong-Haman weir area in Nakdong River during harmful algal boom period from September to October in 2017. Ultrasonic treatment method was applied to disrupt colonies into single cells to enumerate cell density. Among treatment conditions, results from continuously treated for 100 seconds were found to be the optimum to reduce colonies to a suspension of single cell without cell losses under high and low density of Microcystis cells. Lugol iodine fixed cells followed by sonication showed less negative impact of cell damage within the optimal treatment time (100 seconds). Furthermore, disaggregated cells treated by sonication enables microscopic observation more easily since gas vacuoles were collapsed to facilitate sedimentation of cells under the counting chamber for quantitative enumeration of buoyant Microcystis cells.

• Journal of Chest Surgery
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• 제23권3호
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• pp.537-541
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• 1990

Early esophageal carcinoma is defined as a lesion wherein invasion is confined to the mucosa and submucosa without metastasis to lymph node or other organs. Postoperative 5-year survival rate for early esophageal carcinoma is much superior than advanced carcinoma. Unfortunately, because of the anatomic characteristic of esophagus and absence of specific early symptoms, detection is frequently belated, and advanced disease is present at the time of the initial diagnosis. We experienced 2 cases of early esophageal carcinoma. They complained no specific symptoms. The diagnosis was made by barium esophagogram, esophagofiberscopy with dye staining and endoscopic biopsy. We performed esophagectomy with esophagogastrostomy. All had good postoperative course without any complication. We concluded that the combined use of double contrast radiography, esopagofiberscopy aided by intraluminal staining with Toluidine blue or Lugol`s solution, and endoscopic biopsy is very important in the diagnosis of early esophageal carcinoma in high risk patient group.

• 한국해양학회지:바다
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• 제4권4호
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• pp.363-370
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• 1999

1997년 8월 27일 전남 고흥군 외나로도 연안에 그 해 최초로 Cochlodinium polykrikoides에 의한 적조경보 발령시, 동 해역에는 형태상으로 유사하지만 크기가 다른 연쇄상의 무각 와편모조류가 공존하고 있었다. 이들의 24S rRNA 유전자 엽기서열을 분석한 경과, 염기서열의 상동성은 74.9%에 불과하여 두 총은 상이한 종인 것으로 드러났다. 또한 각 종을 분리, 배양하여 형태상의 특성을 비교 관찰한 결과, 20~35 ${\mu}m$ 내외의 큰 종은 국내에 잘 알려진 Cochlodinium polykrikoides이었으며, 12~25 ${\mu}m$ 내외의 작은 종은 아직까지 국내에 보고된 적이 없었던 Gymdinium impudicum인 것으로 밝혀졌다. 각 종의 24S rRNA 유전자 염기서열은 아직 밝혀진 적이 없어 Gcnbank에 보고하였다. 조사 당시 적조는 최고 개체수 30,000 cells $ml^{-1}$의 G. impudicum 적조였다. 본 연구에서는 광학현미경과 해부현미경으로 관찰할 수 있는 두 종의 형태상의 특성과 행동양식을 기술하였으며, Lugol용액으로 고정하여 원형이 변형된 후의 특정도 비교하여 고정시료를 통해서도 종을 구별할 수 있도록 하였다.

• Fisheries and Aquatic Sciences
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• 제2권2호
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• pp.172-175
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• 1999

Relative DNA contents in some harmful algae were measured using DAPI staining and image analysis system. This method was useful to identify some morphologically similar species and isolates from harmful algal blooms (HABs). In exponential phase, Prorocentrum micans had higher relative DNA content (RD) of $1.83\pm0.52$ than any other isolates, followed by Cochlodinium polykrikoides $(1.10\pm0.46)$ Alexandrium tamarense $(0.93\pm0.32)$ Gyrodinium impudicum $(0.56\pm0.17)$, Scrippsiella trochoidea $(0.41\pm0.26)$ and P. minimum$(0.05\pm0.01)$. When they were fixed with Lugol's solution, it was difficult to d,iscern C. polykrikoides from G. impudicum under the light microscope, but the DNA contents were quite different in two species. C. polykrikoides contained about twice as much RD as G. impudicum under the same culture conditions and exponential phase. DAPI­stained DNA feature in C. polykrikodes showed concentrated in the peripheral part of the cell, but in G. impudicum showed a compact structure in the central part. Although A. tamarense and S. trochoidea were morphologically similar under the light microscope, nuclear DNA content of A. tamarense was twice as much as that of S. trochoidea.

• 한국양식학회지
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• 제10권3호
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• pp.227-237
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• 1997

Five species of intertidal clams including Ruditapes philippinarum, Tegillarca granosa, Solen strictus, Heteromacoma irus, and Coecella chinensis were tested for the presence of the protozoan parasite, Perkinsus sp. using fluid thioglycollate medium (FTM) fortified with antibiotics and histological techniques. Each individual clam was placed in a test tube filled with 10ml FTM, placed in totally dark place, and incubated over a week. After incubation the clam tissues were stained with Lugol's iodine solution and examined under a light microscope to find out any hypnospores of Perkensus sp. in the tissues. Cross-sections of the clams were also embedded in paraffin, sliced to 3um, and stained with Harry's hematoxylene and Picro eosine to observe the presence of tomont or trophozoites. Perkinsus sp. were found in the presence of tomont or trophozoites. Perkinsus sp. were found in the tissues of R. philippinarum collected from Kangjin and Wando, along the south coast of Korea. However, Perkinsus sp. was not found in four other species of clams nor R. philippinaurm collected from Kimnyong and Waido in Cheju. A size-dependent Perkinsus sp. infection was found in R. philippinarum collected rom Kangjin and Wando the clams smaller than 15mm in shell width do not exhibit and Perkinsus sp. while other clams greater than 20mm in shell width exhibit almost 100% infection. To determine the number of Perkinsus sp. in the clams, FTM cultured clam tissues were digested with 2M NaOH solution and the number of hypnospores in the tube were counted. The number of hypnospores counted from the tissues indicated that each Manila clam contains 100,000 to 3,500,000 Perkinsus cells or 20,000 to 1,000,000 cells per gram tissue wet weight. The results of cell counts also suggests that such a high occurrence of Perkinsus sp. in the clam may cause mortality, as already reported from other studies of Perkinsus spp.

• 농촌의학ㆍ지역보건
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• 제15권2호
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• pp.107-111
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• 1990

A survey was undertaken to evaluate the present status of intestinal infection in army soldiers. Stool specimen of 417 soldiers fixed by SAF solution were collected from a camp located in area of Nakdong river during the period from August to October of 1990. And these stool samples were examined by formalin-ether sedimentation technique once for helminths and protozoan cysts stained with Lugol's iodine solution. The results obtained in this survey were summarized as follows : l) The overall positive rate of intestinal parasite was 18.0%. 2) The egg positive rate of intestinal helminth was 15.1%, : and 11.5% for Clonorchis sinensis. 5.0% for Metagonimus vokogawai, 1.2% for Ascaris lumbricoides 1.7% for Trichiuris trichiura. 0.2% for Taenia sp. 3) The cyst positive rate of intestinal protozoa was 4.1% ; and 1.4% for Entamoeba coli, 1.9% for Giardia lamblia 0.7% for Entamoeba histolytica, 0.5% for Endolimax nana. 4) Most of samples were positive(85.3%) by single species. 10.7% by two species, 2.7% by three species and 1.3% by four species. 5) Infection rate of intestinal parasites among army soldiers decreased distinctly compared with previous data but it is revealed that the infection rate of Clonorchis sinensis among army soldiers in area of Nakdong river is still high in comparison with ever-reported data. 6) SAF fixatives used in this field survey during summertime was useful to conserve protozoan cyst and helminths ova. Also we could examine stool samples directly by formalin-ether sedimentation technique.