• Parasites, Hosts and Diseases
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• v.27 no.1
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• pp.57-66
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• 1989

A scanning electron microscopic study was performed to observe the tegumental ultrastructures of Paragonimus iloktuenensis according to its developmental stages. The metacercariae were obtained from the liver of the brackish water crab, Sesarma dehaani. Juvenile and adult p. iloktsuenensis were recovered from the experimental rats on 2, 4 and 8 weeks after infection. The findings were summarized as follows: 1. The encysted metacercariae were charaeteristically gourd-shape, with their whole body surface beset with numerous spade-shape spines. The Barge, type II sensory papillae (non-ciliated round swellings) were arranged along the rim of the oral and ventral suckers, 11~12 and 6~8 in numbers respectively, 2. Two-week old juvenile worms, recovered chieay from the liver of the experimental rats, were slender in body shape: with their ventral sucker near the anterior one-third level. The distribution of tegumental spines was less dense than in the encysted metacercariae. The spines were with 1~2 pointed tips and 3~.4 longitudinal splits. Numerous ciliated knob-like, type I papillae were observed in both sides of the oral sucker, and 6 large, type If papillae were arranged along the rim of the ventral sucker. 3. Four week old worms, recovered from the thoracic cavity and/or lung parenchyme of the experimental rats, were thicker than wide in body configuration, and their ventral sucker was located near the anterior one.fourth level. The tegumental spines at ventral surface were grouped, each group with 3~5 aggregated ones. The type I and type II papillae (small-sired) were distributed chiefly around the rim of two suckers. 4. Adult (eight-week old) worms, recovered from the capsules in the lung parenchyme, were very stout, and covered densely with bearfoot like spines. At dorsal surface, cobblestone-like cytoplasmic processes were well-developed, with many tegumental spines embedded in them. It was observed in this study that the tegument of p. iloktsuenensis continued to change and differentiate as the worms grew to be adults.

• Parasites, Hosts and Diseases
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• v.29 no.1
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• pp.21-30
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• 1991

An immunohistochemical study was performed to demonstrate comparative antigenicity of each body structure of the liver fluke, Clonorchis sinensis, such as the digestive tract, reproductive organs, excretory system, tegument and suckers. Indirect immunoperoxidase technique was applied, rising formalin-fixed and paraffin-embedded sections of C. sinensis as the antigen. Pooled cat sera obtained 10 weeks after an experimental infection with C. sinensis and peroxidase-conjugated goat anti-cat IgG were used as the primary and secondary antibodies, respectively. The intensity of immunohistochemical stain was very sensitive upon the titers of the primary and secondary antibodies, and their optimum dilutions were found to be 1:1,000∼1:2,000 and 1:1,000, respectively. The intestinal epithelial cells, intestinal content and excretory bladder showed strong positive coloring reactions even at lower titer (1 : 2,000) of the primary antibody, whereas the uterine wall and eggs, vitelline glands, and male reproductive organs showed only weak positive reactions despite an increase in the antibody titer (1:1,000). On the other hand, the suckers, tegument, subtegumental cells and other parenchyme portions did not reveal any positive immunoperoxidase reaction at the same antibody titers. From the above results, it is highly suggested that the most potent antigenicity of C. sinensis occur from their excretory-secretory substances originated from the digestive and excretory organs.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.263-269
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• 2021

Growth and fruit characteristics of 'Duke' highbush blueberry by mixture of different organic matters in soil were investigated. The soil acidity was 4.2 to 4.8, sawdust treatment was the highest, and peat soil and peatmoss treatments were similar. The organic matter content of the soil was 2.5% for sawdust and 4.1% for soil with peatmoss and peat soil. The soil hardness of all treatment was found to be about 1 ~ 5 kgf cm^-2 which was suitable for growing crops. The number of suckers and main stems were high in the order of peat soil, peatmoss, sawdust treatment. In addition, the blueberry plants in the peatmoss and peat soil treatments had thicker and longer suckers and more shoots than those in the sawdust treatment. Among the characteristics of fruit, there was no statistical difference between the organic materials treatment in weight, diameter, length, and hardness of fruit. However, the total soluble solid and fruit yield were high in the order of peat soil, peatmoss, sawdust treatment. Therefore, as a result of comprehensively reviewing the characteristics of growth and fruits according to the soil environment, it was determined that peatmoss could be replaced with peat soil for stable production in domestic blueberry cultivation.

• Parasites, Hosts and Diseases
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• v.56 no.1
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• pp.49-52
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• 2018

The family Thapariellidae has been reported in only 3 countries since 1990. The objective of this study was to identify Thapariella anastomusa metacercariae in snails in Thailand based on morphological traits using a light (LM) and a scanning electron microscope (SEM). A total of 94 Filopaludina snails were collected and identified as 50 F. martensi martensi and 44 F. doliaris. Metacercariae of T. anastomusa were recovered from the snails by the crushing method. The overall prevalence was 22.3% (21/94), and the mean intensity was 17.0 per snail. The prevalence in F. martensi martensi was 24.0% (12/50) and F. doliaris 20.5% (9/44) with the mean intensity of 18.8 and 14.8 per snail, respectively. SEM revealed traits such as a concave ventral body and well-developed oral and ventral suckers. This study represents the first report of T. anastomusa in South East Asia. While LM and SEM observations provide novel insights into T. anastomusa metacercarial morphology and life history, the trematode's life cycle remains unclear. To date, there has been no report of T. anastomusa causing infections in humans. However, the snails F. martensi martensi and F. doliaris carrying the infective stages of T. anastomosa are frequently consumed by Thai people. This consumption, particularly uncooked snails, may present a risk of Thapariella infections in humans.

• Parasites, Hosts and Diseases
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• v.45 no.3
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• pp.199-204
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• 2007

Metacercariae of Gynaecotyla squatarolae (Digenea: Microphallidae) were discovered from the shore crab, Macrophthalmus dilatatus, purchased at a market in a coastal town of Taean-Eup, Chungcheongnam-do, Republic of Korea. Their adult flukes were confirmed by experimental infection of rats. The metacercariae of G. squatarolae were elliptical ($391.1{\times}362.5{\mu}m$), and the excysted metacercariae had progenetic genital organs, including the ovary and testes. To obtain adult flukes, 6 Sprague-Dawley rats were fed 500 metacercariae each, and killed at days 2, 4, and 6 post-infection. The adult flukes were identified as G. squatarolae (Yamaguti, 1934) Yamaguti, 1939, based on morphological characters, including 2 ventral suckers (1 large and 1 small), a large genital atrium equipped with the cirrus and the metraterm, separated male and female genital pores, a transversely long cirrus pouch, and extensive vitelline follicles. In the present study, it has been first proven that the shore crab M. dilatatus is a second intermediate host for G. squatarolae in the Republic of Korea.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.1
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• pp.50-56
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• 1998

The complementary DNA (cDNA) of potato virus Y- vein necrosis strain (PVY-VN) replicase gene (Nlb) was transformed into tobacco (Nicotiana tabacum cv. Burley 21) plants. Out of 25 putative transformants regenerated, 3 were resistant to PVY-VN, one highly resistant plant with no symptom until seed harvest time and the other two with mild chlorotic spot symptoms at late stages after infection. No symptom was observed in the highly resistant plant, while mild vein necrotic symptoms were developed on suckers of the moderately resistant plants after seed harvest time, In the first generation (T1) via self fertilization, resistance to susceptibility frequency in transgenic plants from the highly resistant transformant was about 3 : 1, while it was lowered much (about 1:2 and 1:19) in T1 of the moderately resistant transformants. In the second generation (T2) of the highly resistant plant, resistance frequencies were similar to T1, but resistance levels varied greatly and appeared to be decreased. Key words : potato virus Y, viral replicate gene, transgenic tobacco plants, resistance.

• Parasites, Hosts and Diseases
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• v.59 no.3
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• pp.311-317
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• 2021

The present study reports a rare case of Taenia saginata infection, which was initially diagnosed as acute cholecystitis in a Tibetan patient at the Qinghai-Tibetan Plateau pastoral area, China. A 45-year-old female was initially diagnosed with acute cholecystitis at a hospital in China. She had a slight fever, weight loss and constipation and complained of pain in the upper abdomen and left back areas. Increase of monocyte, eosinophil and basophil levels were shown. Taenia sp. eggs were detected in a fecal examination. An adult tapeworm approximately 146 cm in length, whitish-yellow color, was collected from the patient after treatment with traditional Chinese medicine. The adult tapeworm had a scolex and proglottids with genital pores. The scolex was rectangular shape with 4 suckers and rostellum without hooklet. The cox1 gene sequence shared 99.5-99.8% homology with that of T. saginata from other regions in China. The patient was diagnosed finally infected with T. saginata by morphological and molecular charateristics.

• Parasites, Hosts and Diseases
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• v.59 no.1
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• pp.55-59
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• 2021

We intended to describe a case of cerebral coenurosis in a long-tailed goral, Naemorhedus caudatus, from Hwacheon-gun, Gangwon-do (Province), in the Korea. The goral, a 10-year-old male, was suffering from neurological symptoms, such as turning the circle to one side without lifting the head straight, and died at 30 days after admission to the wildlife medical rescue center in Chuncheon-si, Gangwon-do. A fluid-filled cyst was detected in the left cerebral hemisphere by computed tomography and magnetic resonance imaging. The cyst removed from the deceased goral was transparent, about 3×3 cm in size, contained a clear fluid and approximately 320 protoscolices invaginating from the internal germinal layer. The protoscolex had 4 suckers and a rostellum with 28 hooklets arranged in 2 rows. By the present study, a case of cerebral coenurosis was first confirmed in a long-tailed goral, N. caudatus, from Gangwon-do, in Korea. The residents frequently exposed in the sylvatic environment should be careful the accidental infections of zoonotic metacestode of Taenia multiceps, Coenurus cerebralis, in Korea.

• Parasites, Hosts and Diseases
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• v.38 no.4
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• pp.237-244
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• 2000

Although oncospheres of Taenia saginata asiatica can develop into cysticerci in immunodeficiency, immunosuppressed, and normal mice, no detailed information on the development features of these cysticerci from SCID mice is available. In the present study, the tumor-like cyst was found in the subcutaneous tissues of each of 10 SCID mice after 38-244 days inoculation with 39,000 oncospheres of T. s. asiatica. These cysts weighed 2.0-9.6 gm and were 1.5-4.3 cm in diameter. The number of cysticerci were collected from these cysts ranged from 125 to 1,794 and the cysticercus recovery rate from 0.3% to 4.6%. All cysticerci were viable with a diameter of 1-6 mm and 9 abnormal ones each with 2 evaginated protoscoleces were also found. The mean length and width of scolex, protoscolex, and bladder were $477{\;}{\times}{\;}558,{\;}756{\;}{\times}{\;}727,{\;}and{\;}1,586{\;}{\times}{\;}1,615{\;}$\mu\textrm{m}$, respectively. The diameters of suckers and rostellum were $220{\mu\textrm{m}}{\;}and{\;}70\mu\textrm{m}$, respectively All cysticerci had two rows of rostellar hooks. These findings suggest that the SCID mouse model can be employed as a tool for long-term maintenance of the biological materials for advanced studies of immunodiagnosis, vaccine development, and evaluation of cestocidal drugs which would be most benefit for the good health of the livestocks.

• Parasites, Hosts and Diseases
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• v.39 no.2
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• pp.85-118
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• 2001

Studies on Gymnophalloides seoi (Digenea: Gymnophallidae) and human infections are briefly reviewed. This minute intestinal fluke was first discovered from a Korean woman suffering from acute pancreatitis and gastrointestinal troubles. It was described as a new species by Lee, Chai and Hong in 1993. The southwestern coastal village where the patient resided was found to be a highly endemic area, and additional endemic areas have been identified. The parasite is very small, 0.33-0.50 mm long and 0.23-0.33 mm wide. and characterized by the presence of a ventral pit. The first intermediate host remains unknown, but the second intermediate host has been found to be the oyster Crassostrea gigas. Man and the Palearctic oystercatcher Haematopus ostralegus have been shown to be natural definitive hosts , and wading birds including the Dentish plover Charadrius alexandrinus are highly susceptible to experimental infection. Gerbils, hamsters, cats, and several strains of mice were also susceptible laboratory hosts. In experimentally infected mice, the parasites inhabit the small intestine, pinching and sucking the root of villi with their large oral suckers, but they did not invade beyond the mucosa in immunocompetent mice. However, they were found to invade the submucosa in immunosuppressed mice. Human G. seoi infections have been found in at least 25 localities; 23 islands on the Yellow Sea or the South Sea, and 2 western coastal villages. The highest Prevalence was found in a village on Aphaedo. Shinan-fun (49% e99 Positive rate) : other areas showed 0.8-25.3% prevalence. Infected people complained of variable degrees of gastrointestinal troubles and indigestion. The infection can be diagnosed by recovery of eggs in the feces; however, an expert is needed to identify the eggs. Praziquantel, 10mg/kg in single dose, is effective for treatment of human infections. Eating raw oysters in endemic areas should be avoided.