• Parasites, Hosts and Diseases
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• 제57권5호
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• pp.537-541
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• 2019

Toxoplasma gondii infection induces parasite infiltration and apoptosis in the spleen. However, dose-dependent parasite infiltration, apoptosis, body weight alternations and survival in mice remain largely unknown. In this study, mice were intraperitoneally infected with 10, 30 or 100 tachyzoites of T. gondii, respectively. Parasite infiltration and apoptosis in the spleen were analyzed on days 3, 7, and 9 post-infection by immunohistochemistry and flow cytometry. Significantly higher levels of T. gondii infiltration and apoptosis in the spleen were found in 30 and 100 tachyzoites infected mice compared to 10 tachyzoites infected mice on days 7 and 9 post-infection. Although 30 and 100 tachyzoites infected mice showed significant body weight loss compared to 10 tachyzoites infected mice, all of the 100, 30, and 10 tachyzoites infected mice died by days 12, 15, and 17, each respectively. Interestingly, T. gondii infiltration in 10 tachyzoites infected mice were limited to capsule area of the spleen on day 9 post-infection. Several areas of parasite infiltrations were found in the 30 tachyzoites infected mice, where noticeable levels of splenic capsule de-adhesion occurred. These results indicated that parasite infiltration and apoptosis in the spleen, as well as body weight loss (survival) are closely correlated with infection dosage. The level of T. gondii infiltration and apoptosis in the spleen and splenic de-adhesion were dependent on the parasite dose.

• Parasites, Hosts and Diseases
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• 제58권5호
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• pp.577-581
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• 2020

A 22-year-old Thai man from the Northeast region presented with acute eye swelling, itching, and discharge on his left eye. He was suspected of having gnathostomiasis and treated with albendazole and prednisolone for 3 weeks. Nine months later, he was treated with high-dose oral prednisolone for the preliminary and differential diagnoses with thyroid-associated orbitopathy and lymphoma. He had been administered prednisolone intermittently over a few years. Then he developed a painless movable mass at the left upper eyelid and recurrent pseudotumor oculi was suspected. The surgical removal of the mass was performed. A white pseudosegmented worm revealed a definite diagnosis of ocular sparganosis by a plerocercoid larva. Molecular diagnosis of the causative species was made based on the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Proper technique of extraction and amplification of short fragments DNA from formalin-fixed paraffin-embedded tissue successfully identified parasite species. The result from the sequencing of the PCR-amplified cox1 fragments in this study showed 99.0% sequence homology to Spirometra ranarum. This is the first report of S. ranarum in Thailand.

• Journal of Plant Biology
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• 제21권1_4호
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• pp.39-44
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• 1978

Acid phosphatase activities were analyzed in $\mu\textrm{g}$ tissue samples from an angiosperm parasite (Cuscuta cephalanthi) and its host plant (Hedera helix) by a fluorometric microtechnique. The apex and the coiling portion of the parasite axis exhibited greater enzyme activies than other portions of the hypha. Acid phosphatase activity in the haustorium was 2-3 times that in the hyphal axis. The vascular bundles of the normal host exhibited the greatest enzyme activity. The acid phosphatase activity in the host infected by the parasite decreased to the activity level of the haustorium.

• Parasites, Hosts and Diseases
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• 제48권2호
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• pp.105-111
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• 2010

To understand the situation of water contamination with Cryptosporidium spp. and Giardia spp. in the northern region of Portugal, we have established a long-term program aimed at pinpointing the sources of surface water and environmental contamination, working with the water-supply industry. Here, we describe the results obtained with raw water samples collected in rivers of the 5 hydrographical basins. A total of 283 samples were analyzed using the Method 1623 EPA, USA. Genetic characterization was performed by PCR and sequencing of genes 18S rRNA of Cryptosporidium spp. and $\beta$-giardin of Giardia spp. Infectious stages of the protozoa were detected in 72.8% (206 of 283) of the water samples, with 15.2% (43 of 283) positive for Giardia duodenalis cysts, 9.5% (27 of 283) positive for Cryptosporidium spp. oocysts, and 48.1% (136 of 283) samples positive for both parasites. The most common zoonotic species found were G. duodenalis assemblages A-I, A-II, B, and E genotypes, and Cryptosporidium parvum, Cryptosporidium andersoni, Cryptosporidium hominis, and Cryptosporidium muris. These results suggest that cryptosporidiosis and giardiasis are important public health issues in northern Portugal. To the authors' knowledge, this is the first report evaluating the concentration of environmental stages of Cryptosporidium and Giardia in raw water samples in the northern region of Portugal.

• 한국항공우주학회지
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• 제39권4호
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• pp.332-340
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• 2011

스트랩다운 탐색기를 탑재한 유도탄의 경우, 비례항법 호밍유도를 위한 관성좌표계 기준 시선각속도 정보를 직접적으로 획득하지 못하기 때문에 유도탄의 자세정보와 탐색기의 지향각 정보를 활용하여 적절히 추정하여야 한다. 하지만, 시선각속도를 추정하는 방법에 따라 획득된 시선각속도 정보에 동체 자세각속도 정보가 포함되어 불필요한 피드백루프(Parasite Loop)가 형성되고, 이로 인해 유도성능이 감소하거나 전체 유도조종루프가 불안정하게 되는 현상(Parasite Effect)이 발생하기도 한다. 본 논문에서는 비례항법 호밍유도를 위한 시선각속도 정보 추정방법과 이에 따라 발생되는 Parasite Loop 원인을 살펴보며, Routh-Hurwitz 안정성 판별법을 이용하여 Parasite Effect를 최소화하는 방안을 제시하도록 한다. 또한 다양한 시뮬레이션을 통해 제안한 방법에 대해 검증하도록 한다.

• 한국가금학회지
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• 제28권2호
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• pp.107-123
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• 2001

• Parasites, Hosts and Diseases
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• 제38권4호
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• pp.275-277
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• 2000

The status of intestinal parasite infections was investigated in two rural villages (Chitrasar, Jerona) in Chitwan District, Nepal in 1999. Stool examination was performed with a total of 300 specimens from schoolchildren by formalin-ether sedinentation technique. The prevalence rate of intestinal parasite infections in the surveyed areas was 44.0%. The prevalence rate in Jerona was slightly higher than that in Chitrasar. The prevalence rate of intestinal parasite infections in female was slighly higher than that in male without statistically significant difference. Entamoeba coli was the most commonly found protozoan parasite (21.0%) followed by Giardia lamblia (13.7%) and others (5.3%). Hookworm was the most prevalent intestinal helminth (13.0%) followed by Trichuris trichiura (3.0%) and others (5.0%). forty-three specimens (14.3%) Showed mixed infections. It is necessary to implement large-scale treatment with anthelminthics, health education and sanitary improvement for intestinal parasite control in the surveyed areas.

• ALGAE
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• 제29권4호
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• pp.279-288
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• 2014

Red algal parasites are common within red algae and are mostly closely related to their hosts, but have a reduced habit. In the past, red algal parasites, due to their reduced morphology, have been given distinct generic names, even though they are often phylogenetically nested in their host's genus. This is a problem nomenclaturally for maintenance of a taxonomy based on monophyly. This study investigates the morphology, genetic variation and distribution of an undescribed red algal parasite growing on its host Rhodophyllis membranacea, widely distributed throughout New Zealand. Microscopy, molecular markers (plastid, mitochondrial, nuclear), and herbarium investigation were used to investigate this species. The parasite is widely distributed throughout New Zealand. All molecular markers clearly show that the parasite is almost identical to the host, even though morphologically quite distinct from members of the host genus. We believe that to maintain monophyly of Rhodophyllis the parasite should be described as a new species of Rhodophyllis, Rhodophyllis parasitica sp. nov. We also recommend that in order to maintain generic monophyly most red algal parasite genera should also be transferred to their host genus.

• Parasites, Hosts and Diseases
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• 제61권1호
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• pp.89-93
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• 2023

Parasite infection rates estimated by examining ancient coprolites can provide insights into parasitism in Joseon society. Using newly discovered Joseon period cases is essential to regularly update the parasite infection rates and reinforce the reliability of our previous estimations. In the present study, we investigated parasite infections in Joseon coprolites newly isolated from the cities of Euijeongbu, Gumi, and Wonju. We then updated the overall parasite infection rates of Joseon period samples (n= 30) as follows: 86.7% (26/30) for Trichuris trichiura, 56.7% (17/30) for Ascaris lumbricoides, 30.0% (9/30) for Clonorchis sinensis, and 30.0% (9/30) for Paragonimus westermani. The parasite infection rates in the Joseon society, estimated through coprolite examination, were very similar to those determined previously despite the addition of new cases to the existing data pool.

• 한국자연치유학회지
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• 제11권2호
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• pp.136-142
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• 2022

배경: 본 연구는 1970년 때부터 현재까지 우리나라의 기생충 감염률의 변화와 관리에 대한 고찰은 자연치유적 관점에서도 필요하다고 본다. 목적: 연구 목적은 감염률이 어떠한 방법에 따라서 감소율의 변화가 현재까지 진행되었는지를 고찰해보는 것이었다. 방법: 문헌 조사를 하였다. 결과: 우리나라는 1970년대까지는 기생충 감염률이 가장 높은 국가 중 하나였다. 감염률을 관리하기 위하여 1966년에는 기생충병 예방법을 제정하였고, 1969년부터 전국적인 기생충 관리 국가사업을 전체 학생을 대상으로 1년에 2회 전체 기생충 충란 양성자에 대한 치료를 1995년까지 수행하였다. 정부는 한국기생충박멸협회에 위탁하여 구충 박멸사업을 2년 간격으로 1971년~2012년까지 8차례를 전국 기생충감염 실태조사를 하였다. 그 결과로 1971년에는 전체 기생충 충란 양성률이 84.3%이었으나 2012년에는 2.6%로 감소하였다. 회충, 폐흡충, 조충 및 장내 원충류는 전국적으로 매우 감소하였다. 결론: 우리나라에서의 성공적인 기생충 관리는 국가적 경제성장력의 증진과 동시에 기생충박멸에 대한 사회적 합의와 개선된 전문적인 기생충 예방지침과 유효한 구충제 공급 등이 체계적으로 관리하여 성공적인 효과를 이루었다고 판단한다. 그리고 자연치유적 관점에서도 중요하다고 생각한다.