• 통합자연과학논문집
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• 제9권4호
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• pp.268-274
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• 2016

Filariasis causing nematode Brugia malayi is shown to harbor wolbachia bacteria as symbionts. The sequenced genome of the wolbachia endosymbiont from B.malayi (wBm) offers an unprecedented opportunity to identify new wolbachia drug targets. Hence the enzyme carbonic anhydrase from wolbachia endosymbiont of Brugia malayi (wBm) which is responsible for the reversible interconversion of carbon dioxide and water to bicarbonate and protons (or vice versa) is chosen as the drug target for filariasis. This enzyme is thought to play critical functions in bacteria by involving in various steps of their life cycle which are important for survival, The 3D structure of wBm carbonic anhydrase is predicted by selecting a suitable template using the similarity search tool, BLAST. The BLAST results shows a hexapeptide transferase family protein from Anaplasma phagocytophilum (PDB ID: 3IXC) having 77% similarity and 54% identity with wBm carbonic anhydrase. Hence the above enzyme is chosen as the template and the 3D structure of carbonic anhydrase is predicted by the tool Modeller9v7. Since the three dimensional structure of carbonic anhydrase from wolbachia endosymbiont of Brugia malayi has not yet solved, attempts were made to predict this protein. The predicted structure is validated and also molecular docking studies are carried out with the suitable inhibitors that have been solved experimentally.

• Parasites, Hosts and Diseases
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• 제51권6호
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• pp.645-650
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• 2013

A simple, rapid, and high-throughput method for detection and identification of Wuchereria bancrofti, Brugia malayi, Brugia pahangi, and Dirofilaria immitis in mosquito vectors and blood samples was developed using a real-time PCR combined with high-resolution melting (HRM) analysis. Amplicons of the 4 filarial species were generated from 5S rRNA and spliced leader sequences by the real-time PCR and their melting temperatures were determined by the HRM method. Melting of amplicons from W. bancrofti, B. malayi, D. immitis, and B. pahangi peaked at $81.5{\pm}0.2^{\circ}C$, $79.0{\pm}0.3^{\circ}C$, $76.8{\pm}0.1^{\circ}C$, and $79.9{\pm}0.1^{\circ}C$, respectively. This assay is relatively cheap since it does not require synthesis of hybridization probes. Its sensitivity and specificity were 100%. It is a rapid and technically simple approach, and an important tool for population surveys as well as molecular xenomonitoring of parasites in vectors.

• Parasites, Hosts and Diseases
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• 제41권1호
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• pp.69-73
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• 2003

Lymphatic filariasis due to Brugia malayi infection was endemic in several areas of South Korea. The infection was controlled, or disappeared, in most areas, with the exception of the remote southwestern islands of Jeonranam-do, including the Heugsan Islands. To discover its current situation, a small-scale survey was performed on the Heugsan islands in September 2000. A total of 378 people, 151 male and 227 female, living in 8 villages (6 on Daeheugsan-do, 1 on Daejang-do, and 1 on Yeongsan-do) were subjected to a night blood survey for microfilaremia, and physical examination for elephantiasis on the extremities. There were 6 (1.6%) microfilaria positive cases, all in females aged 57-72 years, and from only two villages of the Daeheugsan-do area. There were 4 patients with lower leg elephantiasis, but they showed no microfilaremia. The results show that a low-grade endemicity of filariasis remains on the Daeheugsan-do.

• Parasites, Hosts and Diseases
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• 제24권2호
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• pp.201-204
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• 1986

A study on the effect of diethylcarbamazine (DEC) (Supatonin) against Brugia malayi infection was conducted on Cheju Island in September 1965. A total of 182 persons living in a village of Aiwol Myun, Bukcheju-Gun was examined for microfilaraemia. Microscopic examination of smears of $20{\mu}l$ of blood revealed a microfilaria positivity rate of 28.5%. At the end of September 1965, 34 confirmed microfilaria positive cases were treated with DEC at a daily dosage of 5mg/kg body weight. A full course of 12 days of drug administration divided of two rounds for 6 days each was used. The first round of treatment was given under a strict supervision of the author in order to observe carefully side-effects of the drug. The second round of treatment was given in January 1966. The microfilaria density in $20{\mu}l$ of blood of those who received the drug was checked four times; before the treatment, during the first round of the treatment, 2 weeks and 4 months after the completion of the first round. The pre-treatment mean microfilaria density of 104.6 diminished to nearly zero (only two cases with one microfilaria respectively) 2 weeks after the first round and again slightly rose up to 0.5 four months after the first round. These results indicate that DEC (Supatonin) is highly effective to eliminate the microfilaria of B. malayi. However, severe side-effects, e.g. fever (average $38.6^{\circ}C$, maximum $39.7^{\circ}C$), headache, backache and seldom abdominal discomfort etc. were observed. There were two cases of withdrawal from the scheme due to refusal.

• Parasites, Hosts and Diseases
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• 제47권4호
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• pp.323-335
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• 2009

A successful experience of lymphatic filariasis control in the Republic of Korea is briefly reviewed. Filariasis in the Republic of Korea was exclusively caused by infection with Brugia malayi. Over the past several decades from the 1950s to 2006, many investigators exerted their efforts to detection, treatment, and follow-up of filariasis patients in endemic areas, and to control filariasis. Mass, combined with selective, treatments with diethylcarbamazine to microfilaria positive persons had been made them free from microfilaremia and contributed to significant decrease of the microfilarial density in previously endemic areas. Significant decrease of microfilaria positive cases in an area influenced eventually to the endemicity of filariasis in the relevant locality. Together with remarkable economic growth followed by improvement of environmental and personal hygiene and living standards, the factors stated above have contributed to blocking the transmission cycle of B. malayi and led to disappearance of this mosquito-borne ancient disease in the Republic of Korea.

• Parasites, Hosts and Diseases
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• 제58권6호
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• pp.627-634
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• 2020

Belitung district in Bangka-Belitung Province, Indonesia with a population of 0.27 million is endemic for Brugia malayi and 5 rounds of mass drug administration (MDA) were completed by 2010. Based on the results of 3 transmission assessment surveys (TAS), the district is declared as achieving elimination of lymphatic filariasis (LF) in 2017. The findings of an independent survey conducted by the National Institute of Health Research and Development (NIHRD) in the same year showed microfilaria (Mf) prevalence of 1.3% in this district. In 2019, NIHRD conducted microfilaria survey in 2 villages in Belitung district. Screening of 311 and 360 individuals in Lasar and Suak Gual villages showed Mf prevalence of 5.1% and 2.2% with mean Mf density of 120 and 354 mf/ml in the respective villages. Mf prevalence was significantly higher among farmers and fishermen compared to others and the gender specific difference was not significant. The results of a questionnaire based interview showed that 62.4% of the respondents reported to have participated in MDA in Lasar while it was 57.7% in Suak Gual village. About 42% of the Mf positive cases did not participate in MDA. Environmental surveys identified many swampy areas supporting the breeding of Mansonia vector species. Persistence of infection is evident and in the event of successful TAS3 it is necessary to monitor the situation and plan for focal MDA. Appropriate surveillance strategies including xenomonitoring in post-MDA situations need to be developed to prevent resurgence of infection. Possible role of animal reservoirs is discussed.

• Parasites, Hosts and Diseases
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• 제24권1호
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• pp.15-24
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• 1986

1985년 5월부터 동년 11월까지 6개월간 경북 내륙지역에 출현하는 문종류와 계절적 출현소장을 조사함과 아울러 매개문에서의 감염형 유충의 최근 감염상을 관찰하였다. 조사기간중에 채집된 문의 종류는 4속 9종이었으며, 기중 A. sinensis가 최우점종으로 전채집수의 84.7%를 차지하였다. 조사지역에서 A. sinensis를 처음으로 채집할 수 있는 시기는 5월 초순이었으며 이 기간중 기온은 $14.3~22.8^{\circ}C$, 습도는 53~90%였으며, 그 밀도는 1.0마리였다. 4. sinensis의 최대밀도 시기는 7월 중순에서 8월 초순사이였으며 그기간중 기온은 $21.5~30.6^{\circ}C$, 습도는 72~91%였으며 최대밀도는 316.0마리였다. A. sinensis의 야간 흡혈 활동상을 알아 보기 위해 7월 17~18일과 9월 7~8일 2회에 걸쳐 저녁 17시부터 그 다음날 아침 6시까지 1시간 간격으로 채집하였던 바 활동이 가장 활발한 시간은 7월에는 22시에서 23시사이, 9월에는 20시에서 21시사이였으며 아침 6시 이후에는 한마리도 채집할 수 없었다. A. sinensis 218마리를 부검하였던 바 이 가운데 사상충 유충을 전혀 검출할 수 없었다. 이상의 성적으로 미루어 보아 경북 내륙지역의 분포 모기중 A. sinensis가 우점종이며, 매개문에서 사상충의 감염형 유충은 전혀 검출할 수 없음을 알았다.

• Parasites, Hosts and Diseases
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• 제49권1호
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• pp.59-64
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• 2011

A survey of mosquitoes, including the vector status of Brugia malayi filariasis and their relative larval density, was conducted from 2002 to 2005 at several southern remote islands of Jeollanam-do (province), Gyeongsangnam-do, and Jeju-do, Korea, where filariasis was previously endemic. Overall, a total of 9 species belonging to 7 genera were collected. Ochlerotatus togoi (formerly known as Aedes togoi), Anopheles (Hyrcanus) group, and Culex pipiens were the predominant species captured at all areas. Oc. togoi larvae were most frequently collected at salinity levels < 0.5% during June and July, with densities decreasing sharply during the rainy season in August. The most likely explanation for the eradication of filariasis in these areas is suggested to be an aggressive treatment program executed during the 1970s and the 1990s. However, high prevalence of the vector mosquitoes may constitute a potential risk for reemerging of brugian filariasis in these areas.

• Archives of Pharmacal Research
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• 제19권6호
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• pp.475-479
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• 1996

Diethylcarbamazine (DEC, 1-diethylcarbamyl-4-methylpiperazine) is an antiparasitic piperazine derivative used in the treatment of lymphatic filariasis caused by Wuchereria bancrofti, Brugia malayi or grugia timori. DEC-N-oxide is a major metabolite in humans and has antifilarial activity. In carrying out pharmacokinetic studies, gas chromatographic analysis of DEC in plasma can be complicated by the presence of the metabolite, since the thermally unstable DEC-N-oxide is converted back to a material which coelutes with DEC under the conditions of the analysis. We now report a method to separate DEC-N-oxide from DEC in plasma using solid phase extraction with subsequent gas chromatographic analysis using a nitrogen specific detector. One-diethylcarbamyl-4-ethylpiperazine (E-DEC) was the internal standard. The standard curve of DEC was linear in the range of 10 to 200 ng/ml as described by Y=0.0350+0.0128X, $R^2=0.999$. The limit of quantitation was 4 ng/mL. Reproducibility at 10, 100 and 200 ng/mL concentration points of the standard curve gave coefficient variations of 6.1%, 7.8% and 1.6%, respectively. The recovery following solid phase extraction was 99.3% for DEC and 94.8% for the internal standard. This sensitive and specific analytical method is suitable for pharmacokinetic studies of DEC.

• Parasites, Hosts and Diseases
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• 제53권5호
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• pp.583-595
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• 2015

DEAD/DExH-box RNA helicases catalyze the folding and remodeling of RNA molecules in prokaryotic and eukaryotic cells, as well as in many viruses. They are characterized by the presence of the helicase domain with conserved motifs that are essential for ATP binding and hydrolysis, RNA interaction, and unwinding activities. Large families of DEAD/DExH-box proteins have been described in different organisms, and their role in all molecular processes involving RNA, from transcriptional regulation to mRNA decay, have been described. This review aims to summarize the current knowledge about DEAD/DExH-box proteins in selected protozoan and nematode parasites of medical importance worldwide, such as Plasmodium falciparum, Leishmania spp., Trypanosoma spp., Giardia lamblia, Entamoeba histolytica, and Brugia malayi. We discuss the functional characterization of several proteins in an attempt to understand better the molecular mechanisms involving RNA in these pathogens. The current data also highlight that DEAD/DExH-box RNA helicases might represent feasible drug targets due to their vital role in parasite growth and development.