• 대한수의학회지
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• 제36권3호
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• pp.551-563
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• 1996

This study investigated the properties of primary cultured proximal tubule cells in hormonally defined(insulin, transferrin, and hydrocortisone), serum-free medium or 10% serum-supplemented medium. The growth rate of the primary cultured proximal tubule cells was lower in the hormonally defined, serum-free medium than in the 10% serum- supplemented medium(p < 0.05), while the activities of brush border marker enzymes, alkaline phosphatase(AP), leucine aminopeptidase(LAP), and y-glutamyl transpeptidase(${\gamma}$-GTP) were increased(p < 0.05). The activities of these enzymes, however, decreased with the lapse of incubation time to 50-70% after 6 days culture compared to those of the freshly-prepared proximal tubules. The enzymatic activities of the primary cultured proximal tubul cells on 6, 9, 12, and 15 days of culture were significantly increased in the hormonally defined, serum-free medium compared to the 10% serum-supplemented medium(p < 0.05). The functional differentiation of the primary culture was examined by observing multicellular domes of the confluent monolayer, which is indicative of transepithelial solute transport. The dome formation by the proximal tubule cultures occurred at a higher frequency in the hormonally defined, serum-free medium than in the 10% serum-supplemented medium(p < 0.05). Upon electron microscopic examination, an increased density of the brush border was observed in the hormonally defined, serum-free medium compared to the cells grown in 10% serum-supplemented medium. The activities of $Na^+$glucose cotransporter($^{14}C$-a-MG uptake), $Na^+$phosphate cotransportere($^{32}P$ uptake) and $Na^+$ transporter($^{22}Na^+$ uptake) in the brush border membrane, and of $Na^+/K^+$-ATPase($^{86}Rb$ uptake) in the basolateral membrane were significantly stimulated in the hormonally defined, serum-free medium than in 10% serum-supplemented medium(p < 0.05). In conclusion, the primary cultured proximal tubule cells grown in the hormonally defined, serum-free medium demonstrated a slower growth rate, but the functions of cell were enhanced.

• Journal of Pharmaceutical Investigation
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• 제26권3호
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• pp.175-185
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• 1996

To inhibit the enzymatic degradation of leucine enkephalin (Leu-Enk) and its synthetic analog. $[D-ala^2]$-leucine enkephalinamide (YAGFL), in the nasal, rectal and vaginal mucosal and serosal extracts of rabbits, effects of enzyme inhibitors such as amastatin (AM), puromycin (PM), thiorphan (TP), thimerosal (TM), EDTA, N-carboxymethyl-Phe-Leu (CPL), phenylethyl alcohol (PEA), phenylmercuric acetate (PMA), benzalkonium chloride (BC) and modified cyclodextrins, alone or in combination, were observed by assaying the pentapeptides staying intact during incubation. Mucosa extracts were prepared by exposing freshly-excised mucosal specimens mounted on Valia-Chien cells to isotonic phosphate buffer while stirring. The degradation of Leu-Enk and YAGFL followed the apparent first-order kinetics. The half-lives (mean) in the nasal, rectal and vaginal mucosal extracts were found to be 1.07, 0.33 and 1.14 hr for Leu-Enk, and 16.9, 6.2 and 6.8 hr for YAGFL, respectively. AM or PM, which is an aminopeptidase inhibitor, did not show a sufficient inhibition of Leu-Enk $(50\;{\mu}g/ml)$ degradation in all kinds of extracts. $Dimethyl-{\beta}-cyclodextrin\;(DM-{\beta}-CyD)$ decreased the degradation rate constants of Leu-Enk about 2 or 3 times, comparing with no additive. However, the use of mixed inhibitors of AM $(50\;{\mu}M)$/TM (0.25 mM)/EDTA (5 mM) resulted in a full stabilization of Leu-Enk by decreasing the degradation rate constants 67.3, 161.3 and 113.8 times far the nasal, rectal and vaginal mucosal extracts, respectively, comparing with no inhibitor. With mixed inhibitors, Leu-Enk remained intact more than 90% after 6 hr-incubation. In the stabilization of YAGFL, hM, TP or CPL alone showed little efffct, and some additives demonstrated a considerable inhibition of YAGFL degradation in the rank order of TM > BC > EDTA. However, the addition of mixed inhibitors such as TM (0.5 mM) and EDTA (5 mM) into the extracts protected YAGFL from the degradation by more than 85% even after 24 hr-incubation, suggesting almost complete inhibition of YAGFL degradation in the extract. On the other hand, $DM-{\beta}-CyD\;or\;hydroxypropyl-{\beta}-cyclodextrin$ (10%) were also found to retard enzymatic degradation rates of YAGFL markedly, and resulted in staying intact more than 80% of YAGFL in the nasal and vaginal mucosal extracts, and more than 60% in the rectal mucosal extract after 16 hr-incubation.

• Parasites, Hosts and Diseases
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• 제31권1호
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• pp.13-20
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• 1993

간흡충에 감염되었을 때 나타나는 조직병리학적 소견의 변화로는 담관 직경이 확장되고 담관벽이 비후되며, 담관 상피층에 선종성 증식과 배세포 화생이 관찰되었다. 치료 후에는 이러한 변화 중에서 화생이 소실되나 선종성 증식은 상당히 완화되어 잔존하고 담관벽의 비후는 지속된다. 이러한 형태학적인 변화는 선종성인 특징이 있어 어떠한 분비기능이 예상되었다. 이 연구에서는 특히 소장의 분비물이 담관 점막층에서 분비되는가를 확인하고자 하였다. 간흡충 피낭유충을 300개씩 8마리의 토끼에 감염시킨 후, 14주에 프라지관텔로 치료하여 구층 후 6개월 및 1년에 간을 적출하고, 파라핀 포매하여 절편을 만들어 분비물에 대하여 면역조직화학법을 시행하였다. Gastrln과 secretin은 정상토기의 간내 담관 및 감염된 담관에서 나타나지 않았다. Serotonin은 비감염 간 내 담관에서는 관찰되지 않았으나, 감염 대조군의 담관상퍼층에서 몇 개의 양성 세포가 관찰되었다. 그러나 치료 후 6개월에는 관찰되지 않았다. 또한 휜쥐에 100개씩 간흡충 피낭유충을 감염시키고 증식된 상피 층에서 소장 미소응모막 효소의 활성을 관찰한 바, alkalinephosphatase의 활성이 감염군에서 대조군과 같은 정도로 관찰되 었으나 sucrose, trehalase, lactate, leucine annnopeptidase의 활성은 나타나지 않았다. 이 결과를 통하여 간흡충 감염시에 증식된 담관상피에 소수의 serotonin 분비세포가 있음을 관찰하였고 다른 소장의 분비기능은 생기지 않음을 확인하였다. 이 serotonin을 포함한 세포는 비만세포로 추정된다.

• 한국균학회지
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• 제24권2호통권77호
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• pp.111-126
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• 1996

표고 Lentinus edodes의 균사체로부터 핵을 분리하여 사철느타리 Pleurotus florida 원형질체에 폴리에틸렌 글라이콜로 전이하여 속간(屬間) 핵전이체(核轉移體)를 16균주 얻었다. 주된 핵전이주는 합핵체(合核體) synkaryon 또는 이질핵체로 꺽쇠연결체 clamp connections가 없었다. 그러나 톱밥배지를 이용하여 일정한 저온상태에서 광을 조사하여 꺽쇠연결체를 가진 균사가 다시 생장하여 사철느타리와 유사한 자실체를 형성하였으나 갓색택은 다소 달랐다. 꺽쇠연결체 형성에 영향을 주는 주요한 요인으로는 광, 온도, 배지의 영양, 배지의 생리적 상태로 나타났다. 핵치환체(核置換體) reconstituted cell는 꺽쇠연결체를 가진 표고와 유사한 균총형태로 자실체도 표고와 거의 유사하였다. 핵융합체(核融合體) nuclear hybrid는 이질배수체(異質倍數體) heteroploid로 균총생장이 빠르고 benormyl 첨가배지에서 균총분리가 나타나며 꺽쇠연결체와 자실체를 형성하지 않았다. 동위효소 esterase, leucine aminopeptidase 분석결과 핵융합체는 전혀 새로운 벤드양상이었으나 합핵체는 사철느타리의 주된 밴드를 형성하면서 양친에 없는 다소의 새로운 밴드를 형성하여 구분되었다. PCR에 의한 RAPD 벤드의 크기는 0.25-4.0 Kb였으며 유전유사도 분석으로 5군으로 구분할 수 있었는데 표고와 핵치환체, 핵합체 p669, 사철느타리와 12 핵합체, 핵융합체 p674, 핵융합체 p678이었다. 합핵체의 담자포자로 2 핵전이체를 유전분석한 결과 원영양형(原營養型) prototroph과 영양요구형(營養要求型) riboflavine으로 분리되었는데 그 비는 1 : 1, 1 : 2였다.

• 한국미생물·생명공학회지
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• 제49권3호
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• pp.391-402
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• 2021

Earthworms play an important role in soil fertilization, interacting continually with microorganisms. This study aims to demonstrate the existence of beneficial microorganisms living in the earthworm's immune system, the coelomic fluid. To achieve this goal, a molecular identification technique was performed, using cytochrome c oxidase I (COI) barcoding to identify abundant endogenic earthworms inhabiting the temperate zone of Rabat, Morocco. Then, 16S rDNA and ITS sequencing techniques were adopted for bacteria and fungi, respectively. Biochemical analysis, showed the ability of bacteria to produce characteristic enzymes and utilize substrates. Qualitative screening of plant growth-promoting traits, including nitrogen fixation, phosphate and potassium solubilization, and indole acetic acid (IAA) production, was also performed. The result of mitochondrial COI barcoding allowed the identification of the earthworm species Aporrectodea molleri. Phenotypic and genotypic studies of the sixteen isolated bacteria and the two isolated fungi showed that they belong to the Pseudomonas, Aeromonas, Bacillus, Buttiauxella, Enterobacter, Pantoea, and Raoultella, and the Penicillium genera, respectively. Most of the isolated bacteria in the coelomic fluid showed the ability to produce β-glucosidase, β-glucosaminidase, Glutamyl-β-naphthylamidase, and aminopeptidase enzymes, utilizing substrates like aliphatic thiol, sorbitol, and fatty acid ester. Furthermore, three bacteria were able to fix nitrogen, solubilize phosphate and potassium, and produce IAA. This initial study demonstrated that despite the immune property of earthworms' coelomic fluid, it harbors beneficial microorganisms. Thus, the presence of resistant microorganisms in the earthworm's immune system highlights a possible selection process at the coelomic fluid level.