• Parasites, Hosts and Diseases
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• 제44권4호
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• pp.321-330
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• 2006

The pathogenic mechanism of granulomatous amebic encephalitis (GAE) and amebic keratitis (AK) by Acanthamoeba has yet to be clarified. Pretense has been recognized to play an important role in the pathogenesis of GAE and AK. In the present study, we have compared specific activity and cytopathic effects (CPE) of purified 33 kDa serine proteinases from Acanthamoeba strains with different degree of virulence (A. healyi OC-3A, A. lugdunensis KA/E2, and A. castelianii Neff). Trophozoites of the 3 strains revealed different degrees of CPE on human corneal epithelial (HCE) cells. The effect was remarkably reduced by adding phenylmethylsulfonylfluoride (PMSF), a serine proteinase inhibitor. This result indicated that PMSF-susceptible proteinase is the main component causing cytopathy to HCE cells by Acanthamoeba. The purified 33 kDa serine proteinase showed strong activity toward HCE cells and extracellular matrix proteins. The purified proteinase from OC-3A, the most virulent strain, demonstrated the highest enzyme activity compared to KA/E2, an ocular isolate, and Neff, a soil isolate. Polyclonal antibodies against the purified 33 kDa serine proteinase inhibit almost completely the proteolytic activity of culture supernatant of Acanthamoeba. In line with these results, the 33 kDa serine proteinase is suggested to play an important role in pathogenesis and to be the main component of virulence factor of Acanthamoeba.

• 한국안광학회지
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• 제9권2호
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• pp.233-239
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• 2004

대학생들의 소프트 콘택트렌즈 착용에 대한 실태 연구에 대한 결과는 다음과 같다. 1. 대게 콘택트렌즈 착용자들의 최초 연령은 19세 또는 20세이다. 그러나 여성에서 콘택트렌즈 착용의 최초 연령의 분포는 10대 초기에서 20대 초기까지 넓은 분포를 가진다. 2. 대게의 피검자에서 콘택트렌즈 착용자에 대한 시력 검사의 임상 테스트와 콘택트렌즈의 구입 장소는 안경원이다. 3. 콘택트렌즈 착용의 장점에 대해서 대게의 남성 피검자들은 스포츠를 위해서 사용되나, 대부분의 여성 피검자들은 미용을 위해서 사용한다. 4. 대게 피검자들은 콘택트렌즈 착용 후 부작용 경험은 충혈, 이물감, 그리고 안통 등 이다. 5. 대부분의 피검자들은 콘택트렌즈 착용에 의한 안질환의 경험은 결막염이다. 단지 일부 피검자들은 각막염을 경험 한다. 6. 소프트 콘택트렌즈 착용에 의한 부작용 후 콘택트렌즈 처리에서, 대부분의 피검자들은 이전 콘택트렌즈의 재사용을 하였으나, 일부 피검자들은 새로운 렌즈의 교체를 원하였고, 역시 일부 피검자들은 콘택트렌즈의 착용을 거절하였다.

• 대한약침학회지
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• 제10권1호통권22호
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• pp.79-84
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• 2007

Objective : This experimental study was performed to investigate the effect of Coptidis rhizoma extract compared with quantity on Staphylococcus epidermidis that induce keratitis. Methods : MIC was measured by dropping to 50${\mu}l$ according to density Coptidis rhizoma extract(100%, 10%, 1%, 0.1%) compared with quantity(40g, 80g, 160g). Anti-bacterial potency was measured by the size of inhibition zone with change of volume. Results : 1. MIC on Staphylococcus epidermidis in Coptidis rhizoma extract was showed anti-bacterial potency compared with quantity and density in 100% and 10% of all samples(40g, 80g, 160g). 2. MIC on Staphylococcus epidermidis in Coptidis rhizoma extract(40g, 80g, 160g) was showed anti-bacterial potency compared with quantity all samples($20{\mu}l$, $30{\mu}l$, $40{\mu}l$, $50{\mu}l$) in 100% density, but anti-bacterial potency of 80g, $50{\mu}l$ Coptidis rhizoma extract decreased compared with 40g, $50{\mu}l$. 3. MIC on Staphylococcus epidermidis in 40g Coptidis rhizoma extract was showed in $50{\mu}l$, $40{\mu}l$ of 10% density, 80g Coptidis rhizoma extract was showed in $50{\mu}l$ of 10% density, 160g Coptidis rhizoma extract was showed in $50{\mu}l$, $40{\mu}l$, $30{\mu}l$ of 10% density. Conclusions : Coptidis rhizoma extract was showed anti-bacterial potency compare with quantity and density. In herbal drug, anti-bacterial potency compare with quantity and density must be studied.

• 한국안광학회지
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• 제8권2호
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• pp.65-69
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• 2003

본 연구는 천연보존제인 자몽씨 추출물과 합성보존제인 $H_2O_2$를 사용하여 soft contact lens 착용시 각막염의 원인중 하나인 Gram negative bacteria인 Pseudomonas aeruginosa 대한 살균효과를 알아보았다. Pseudomonas aeruginosa는 4주간 배양하여 포낭 형태를 이루게 한 다음 $7{\times}10^6CFU/m{\ell}$의 현탁액에 soft contact lens를 오염시킨 후 천연보존제와 합성보존제의 살균 효과를 비교하였다. 현탁액에 담군 120분후 균의 생존률은 천연보존제는 $1{\times}10^3CFU/m{\ell}$ 합성보존제는 $0.5{\times}10^2CFU/m{\ell}$으로 나타나 유의한 차이는 없었다. 하지만 합성보존제의 경우 눈에 자극감이나 화학적 안 외상을 줄 수 있는 점을 고려하면 자몽씨 추출액과 같은 인체에 무독한 천연 보존제의 개발이 필요한 것으로 나타났다.

• Parasites, Hosts and Diseases
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• 제54권4호
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• pp.447-453
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• 2016

Acanthamoeba, a free-living amoeba, is widely distributed in the environment, water sources, soil, dust, and air. It can cause keratitis in contact lens wearers with poor hygiene and also fatal granulomatous amebic encephalitis (GAE) in immunocompromised hosts. The aim of this study was to gain some insights into the distribution and genotypes of the potentially pathogenic species of Acanthamoeba present in water sources in north of Iran. Total 43 Acanthamoeba species were isolated from 77 water samples taken from different water sources within the Mazandaran province in Northern Iran (Sari city and suburbs). Isolates were identified based on cyst and trophozoite morphological characteristics as well genetics. PCR fragments corresponding to the small-subunit 18S rRNA gene were sequenced for 20 of 43 positive isolates. The results revealed that 83.3% of sequenced isolates belonged to the T4 genotype and the rest belonged to the T2 genotype. Our results indicated that Acanthamoeba is widely distributed in Sari city. As the incidence in Iran of amoebic keratitis has increased in recent years, the exact estimation of the prevalence of this amoeba and its predominant genotype may play a crucial role in prevention of the disease. Sari city has several rivers, seashores, and natural recreational amenities, which attract visitors during the year. This is the first report of Acanthamoeba genotypes from water sources in Sari city, Mazandaran province of Iran, and the results suggest that more attention is needed to protect the visiting population and immunocompromised individuals.

• Parasites, Hosts and Diseases
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• 제49권1호
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• pp.1-8
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• 2011

The pathogenesis and pathophysiology of Acanthamoeba infections remain incompletely understood. Phospholipases are known to cleave phospholipids, suggesting their possible involvement in the host cell plasma membrane disruption leading to host cell penetration and lysis. The aims of the present study were to determine phospholipase activities in Acanthamoeba and to determine their roles in the pathogenesis of Acanthamoeba. Using an encephalitis isolate (T1 genotype), a keratitis isolate (T4 genotype), and an environmental isolate (T7 genotype), we demonstrated that Acanthamoeba exhibited phospholipase $A_2$ (PLA$_2$). and phospholipase D (PLD) activities in a spectrophotometry-based assay. Interestingly, the encephalitis isolates of Acanthamoeba exhibited higher phospholipase activities as compared with the keratitis isolates, but the environmental isolates exhibited the highest phospholipase activities. Moreover, Acanthamoeba isolates exhibited higher PLD activities compared with the PLA$_2$. Acanthamoeba exhibited optimal phospholipase activities at $37^{\circ}C$ and at neutral pH indicating their physiological relevance. The functional role of phospholipases was determined by in vitro assays using human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. We observed that a PLD-specific inhibitor, i.e., compound 48/80, partially inhibited Acanthamoeba encephalitis isolate cytotoxicity of the host cells, while PLA$_2$-specific inhibitor, i.e., cytidine 5'-diphosphocholine, had no effect on parasite-mediated HBMEC cytotoxicity. Overall, the T7 exhibited higher phospholipase activities as compared to the T4. In contract, the T7 exhibited minimal binding to, or cytotoxicity of, HBMEC.

• 한국어병학회지
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• 제17권2호
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• pp.83-90
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• 2004

제주도에서 양식되는 돌돔에서 저수온기에 체표에 출혈성 패혈증 혹은 진무름 및 안구백탁이 수반되며 폐사하는 증상이 지속적으로 발견되었다. 이러한 증상의 원인균으로 추정되는 세균을 병어의 체표 및 장기에서 순수분리하였고 형태학적, 배양적 생화학적 조사 및 16S rDNA sequencing 분석 결과 Pseudomonas anguilliseptica로 동정되었다. 본 균주의 병원성 유무를 확인하기 위하여 인위 감염시험을 실시하였고, 그 결과 시험구에서 21일만에 실험어 20마리 모두가 자연감염된 병어와 유사한 증상으로 폐사하였다. 분리균주의 생육 최적 온도는 $\25^circ{C}$였고 생육 최적 pH는 7-8사이로 좁은 범위를 보였다. 낮은 염분농도에서 생육능이 우수하였으며 3%의 염분이 첨가된 배지에서도 생육능이 양호하였다. 약제내성 검사에서는 doxycycline, chloramphenicol, ciprofloxacin, erythromycin, flumequine, nalidixic acid, norfloxacin, ofloxacin에 감수성이 높게 나타났으나 페니실린계의 항생제에 높은 내성을 나타내었다.

• Parasites, Hosts and Diseases
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• 제57권3호
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• pp.217-223
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• 2019

Acanthamoeba castellanii has ubiquitous distribution and causes primary acanthamoebic keratitis (AK). AK is a common disease in contact lens wearers and results in permanent visual impairment or blindness. In this study, we observed the cytopathic effect, in vitro cytotoxicity, and secretion pattern of cytokines in human corneal epithelial cells (HCECs) induced by A. castellanii trophozoites and/or cysts. Morphological observation revealed that panked dendritic HCECs co-cultured with amoeba cysts had changed into round shape and gradually died. Such changes were more severe in co-culture with cyst than those of co-cultivation with trophozoites. In vitro cytotoxicity assay revealed the highest cytotoxicity to HCECs in the co-culture system with amoeba cysts. A. castellanii induced the expression of $IL-1{\alpha}$, IL-6, IL-8, and CXCL1 in HCECs. Secreted levels of $IL-1{\alpha}$, IL-6, and IL-8 in HCECs co-cultured with both trophozoites and cysts were increased at an early incubation time (3 and 6 hr). These results suggested that cytopathic changes and pro-inflammatory cytokines release of HCECs in response to A. castellanii, especially amoebic cysts, are an important mechanism for AK development.

• 대한의생명과학회지
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• 제18권3호
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• pp.313-318
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• 2012

Acanthamoeba is an opportunistic pathogen known to cause granulomatous amoebic encephalitis and amebic keratitis. Acanthamoeba exhibits life cycle consisting of trophozoite and cyst, and the cyst is highly resistant to variable antibiotics and therapeutic agents. To understand the encystation mechanism of Acanthamoeba, the expression profiles of trophozoite and cyst were compared by gene ontology (GO) analysis. Ribosomal proteins and cytoskeletal proteins were highly expressed in trophozoite. In cyst, various protease, and signal transduction - and protein turnover - related proteins were highly expressed. These results correlated with eukaryotic orthologous groups (KOG) assignment and microarray analysis of Acanthamoeba trophozoite and cyst ESTs. The information of differential expression profiles of trophozoite and cyst would provide important clues for research on encystation mechanism of cyst forming protozoa including Acanthamoeba.

• 한방안이비인후피부과학회지
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• 제19권2호
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• pp.19-25
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• 2006

Objective : This experimental study was performed to investigate the effect of Soyum Herbal-acupuncture, Hwangryunhaedoktang & Coptidis rhizoma on Staphylococcus epidermidis that induce keratitis. Methods : MIC was measured by dropping to $50{\mu}l$ according to density Soyum Herbal-acupuncture, Hwangryunhaedoktang & Coptidis rhizoma(100%, 10%, 1%, 0.1%). Anti-bacterial potency was measured by the size of inhibition zone with change of volume. Results : 1. MIC on Staphylococcus epidermidis in Soyum Herbal-acupuncture dippear all sample. 2. MIC on Staphylococcus epidermidis in Hwangryunhaedoktang disappear all sample. 3. MIC on Staphylococcus epidermidis in Coptidis rhizoma was 100%, $50{\mu}l$ and anti-bacterial potency increase compare with quantity. Conclusions : The present author think that Soyum Herbal-acupuncture must be extracted a new method for anti-bacterial potency and Coptidis rhizoma was made Herbal-acupuncture for eye drops.