• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.431-438
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• 2000

To clarify the annual reproductive cycle in a rockfish, Sebastes schlegeli, monthly changes in gonadosomatic index (GSI), hepatosomatic index (HSI) and histological feature of gonads and plasma levels of sex steroid hormones ($estradiol-l7{\beta},\;17{\alpha},\;20{\beta}-dihydroxy-4-pregnen-3-one,\;testosterone\;and\;11-ketotestosterone$) were investigated. The annual reproductive cycle in females could be divided into 5 periods as follows: 1) recovery period (June to September): serum level of $estradiol-l7{\beta}$ increased gradually; 2) vitellogenesis period (Septemer to february) : vitellogenic oocytes were obsewed, GSI sustained high value, and serum level of $estradiol-l7{\beta}$ increased; 3) gestation period (February-April): developing larva showed in the ovary, and serum levels of $17{\alpha},\;20{\beta}-dihydroxy-4-pregnen-3-one$ and testosterone increased; 4) partrition period (April to May) : larva were delivered, and value of GSI and serum levels of hormones decreased rapidly; 5) resting period (May to June) : value of GSI and serum levels of $estradiol-l7{\beta}$ and testosterone remained low. The annual reproductive cycle in males could be divided into 6 periods; 1) early maturation period (April to June): value of GSI and serum levels of hormones incresed gradually, cyst of spermatogonia incresed in number, and a small number of cyst of spermatocyte was observed; 2) mid-maturation perid (June to September); value of GSI and serum levels of hormones increased, and germ cells in many cysts were undergoing active sperrnatogenesis; 3) late maturation period (September to November) : value of GSI and serum levels of hormones remained high and spermatozoa were released into the lumina of the seminal lobules; 3) spermatozoa dischaging period (Nobember to December) : the lumina of the seminal lobules were enlarged and filled with mature spermatozoa; 4) degeneration period (December to Februauy)i value of GSI decresed and cyst of spermatocyte were decresed in number; 5) resting period (December to April) : no histological changes of testes were observed, and value of GSI and serum levels of hormones remained low. In November, the lumina of the seminal lobules were filled with mature spermatozoa and sperm masses were present in the ovarian cavity. Thus, copulation in this species occurred in November and December.

• Korean Journal Plant Pathology
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• v.2 no.3
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• pp.199-206
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• 1986

Penetration level, female development and histological changes in infected root tissues were investigated following inoculation with different inoculum levels (110,440 and 1760 juveniles/plant) of Heterodera glycines (SCN) race 3 on susceptible 'Lee' and resistant 'Pickett' soybean cultivars. Penetration level was lower in Pickett at the higher inoculum levels but no differences were detected in Lee. However, the lower penetration level in the resistant soybean cultivar appeared not to be directly related to plant resistance (female maturation). The number of females recovered from Lee was lower at the highest inoculum level. The number of females maturing on Pickett was much less than that on Lee, showing that changes of SCN population is associated with the number of SCN maturing rather than nematode penetration. In Lee mono-infection sites (a single nematode per site) syncytia had dense cytoplasm and no central vacuoles. while multi-infected sites (many overlapping nematodes per site) had syncytia with a large central vacuole and many small vacuoles. Resistant responses in mono-and multi-infected root tissues of Pickett were delayed and rapid necrosis, respectively. The differences in tissue response are suggested as a mechanism that controls density-dependent population changes in resistant and/or susceptible soybean cultivars.

• 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.56 no.5
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• pp.429-435
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• 2018

Toxoplasma gondii is a ubiquitous protozoan parasite responsible for causing toxoplasmosis. Preventive measures for toxoplasmosis are currently lacking and as such, development of novel vaccines are of urgent need. In this study, we generated 2 virus-like particles (VLPs) vaccines expressing T. gondii rhoptry protein 4 (ROP4) or rhoptry protein 18 (ROP18) using influenza matrix protein (M1) as a core protein. Mice were intranasally immunized with VLPs vaccines and after the last immunization, mice were challenged with ME49 cysts. Protective efficacy was assessed and compared by determining serum antibody responses, body weight changes and the reduction of cyst counts in the brain. ROP18 VLPs-immunized mice induced greater levels of IgG and IgA antibody responses than those immunized with ROP4 VLPs. ROP18 VLPs immunization significantly reduced body weight loss and the number of brain cysts in mice compared to ROP4 VLPs post-challenge. These results indicate that T. gondii ROP18 VLPs elicited better protective efficacy than ROP4 VLPs, providing important insight into vaccine design strategy.

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.323-331
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• 2003

We performed this study to determine the late biological effect of gamma radiation and effect of Bu-Zhong-Yi-Qi-Tang (BZYQT), a prescription of traditional Oriental medicine, on radiation-induced late biological effect (survival, hematological change, carcinogenesis) of mice irradiated with 3 Gy of gamma-radiation. There were little difference in body weights between normal and irradiated mice. Survival rate were decreased in irradiated mice and the survival rate and mean survival time of the groups treated with BZYQT were far better than the irradiation control group. A significant elevation of total leukocyte or lymphocyte counts was seen at week 4 and 12 of the group treated with BZYQT. Stimulated recovery by the extract from BZYQT was also observed in thrombocyte. Main gross findings of irradiated mice were appeared as enlargement of spleen, thymus and liver, tumorous nodules of lung and cyst or mass of ovary. Microscopically, there were various findings including hematopoietic and lymphoid tumor, lung cancer, ovarian cancer and cancer of other lesions. BZYQT reduced the incidence of tumor development. Further studies are needed to characterize better the protective nature of ingredients and active compounds.

• Clinical and Experimental Pediatrics
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• v.61 no.1
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• pp.30-34
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• 2018

Congenital pulmonary airway malformation (CPAM), previously known as congenital cystic adenomatoid malformation, is a rare developmental lung abnormality associated with rhabdomyosarcoma, pleuropulmonary blastoma, and mucinous adenocarcinoma of the lung. We report an unusual case of a 10-day-old male newborn with a left lower lobe pulmonary cyst who underwent lobectomy, which revealed type II CPAM complicated by multifocal mucinous adenocarcinoma. KRAS sequencing revealed a somatic mutation in Codon12 ($GGT{\rightarrow}GAT$), suggesting the development of a mucinous adenocarcinoma in the background of mucinous metaplasia. Mucinous adenocarcinoma is the most common lung tumor associated with CPAM, but it generally occurs in older children and adults. Further, all cases in the literature are of type I CPAM. This case in a neonate indicates that malignant transformation can occur very early in type II CPAM.

• Parasites, Hosts and Diseases
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• v.55 no.5
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• pp.549-553
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• 2017

The information on mortality from echinococcosis is important not only for a better understanding of the severity of the disease, but also for evaluating the effectiveness of public health interventions. The aim of this research was to study the causes of mortality from echinococcosis. We have collected and analyzed the materials of 1,470 patients in 10 age - groups in the Republic of Armenia (from 2000 to 2016). To find out the causes of mortality from echinococcosis, we have analyzed the medical histories and protocols of postmortem examinations of 19 deaths from echinococcosis and 17 deaths due to other indirect causes not associated with the parasite. The average annual death rate from echinococcosis is 0.007 per 10,000 population, and the mortality is 1.29 (per 100 patients). The highest mortality occurs in people aged 70-79. Mortality from echinococcosis is also recorded among the unoperated children. The rupture of the parasitic cyst and hepatic insufficiency are major among the direct causes of mortality. Sometimes the hydatid cysts unrecognized during the life were first diagnosed at autopsy. Insufficient qualification of doctors in the field of helminthology, as well as the latent course of the disease or manifestation of minor symptoms in echinococcosis over a long period often led to medical errors. Further decline in mortality can be achieved by early diagnosis, timely hospitalization and treatment before the development of severe complications worsening the prognosis and outcomes of surgical intervention.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.3
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• pp.202-208
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• 2004

The spatio-temporal distribution of dinoflagellate resting cysts was investigated by palynological processing to understand the harmful algal bloom (HAB) potential in the sediment of the Saemangeun area in 2003. In total, thirty-two dinoflagellate species were identified, and their concentrations were in the range of $6-1,618\;cysts{\cdot}g^{-1}$ (dry weight). The concentrations of resting cysts were higher in the spring (26 species, $64-1,101\;cysts{\cdot}g^{-1})$ and summer (30 species, $81-1,618\;cysts{\cdot}g^{-1})$ than in the autumn (32 species, $6-1,150\;cysts{\cdot}g^{-1})$ and winter (24 species, $25-728\;cysts{\cdot}g^{-1}).$ The composition rate of the heterotrophic dinoflagellate species to the total, which is closely related to the eutrophication process, to ranged from 6 to $29\%$ in the study area. The most dominant species was toxic Alexandrium tamarense/catenella $(25\%)$ followed by Gonyaulax scrippsea $(9\%)$ and toxic Protoceratium reticulatum $(5\%).$ Given the high abundance of the toxigenic dinoflagellate species, the Saemangeun area is considered to have the great potential for HABs in the future.

• Development and Reproduction
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• v.25 no.3
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• pp.123-131
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• 2021

We report on the gonadal structure abnormality and intersexuality found from a survey regarding the reproductive potential of the rock bream, Oplegnathus fasciatus, along the southern coast of Korea. In total, 448 samples were collected for histological analysis (total length 27.5±6.8 cm; total weight 522.9±385.6 g). The sex ratio (F:M) was 1:0.46 (n=307:141), with 68.5% being females. The frequency of oocyte atresia and ovarian neoplasm in the females was 85.3% and 21.5%, respectively, and the frequency of testicular lobule and cyst deformation and testicular neoplasm in the males was 73.1% and 37.6%, respectively. The scale formation in the ovary and testis was approximately 2.0% for both sexes. The intersexuality was 42.2%, with the intersexuality among females being 49.5%, which was significantly higher than that of males (26.2%). Such findings indicate a negative impact on the reproductive output of the rock bream along the southern coast of Korea; however, a more detailed study is required to ascertain accurate causes.

• ALGAE
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• v.34 no.3
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• pp.199-216
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• 2019

Platysiphon verticillatus and Punctaria glacialis are synonymized by mainly on the basis of shared genes, nine identical sequences. Our hypothesis is that synonymy is erroneous. We posit the many differences of biological features between the two species, their ecological preferences, and occurrences do not support synonymy. Arcticophycus (nov. gen.) is described and contains the new combination Arcticophycus glacialis. Asexual, vegetative, life histories are proposed. Novel reproductive structures are described including previously unknown features of thallus development in the life history of both species. Discovery of the novel Platysiphon cyst, and dual sporangia types in Arcticophycus, is critical in establishing a probable strategy for survival through the Arctic winter for each annual species. Pl. verticillatus is erect, tubular, ovoid to circular in X sections, flaccid, non-parenchymatous, light brown, 10-15 cm high with distinctive photosynthetic hairs in clusters or whorled on the upper one third of the thallus. A. glacialis is erect, planar, robust, parenchymatous, dark brown and hairs absent. The Halosiphon clade is named, consisting of four genera: Halosiphon, Platysiphon, Arcticophycus, and Stschapovia. Occurrence of these genera is identified. Emended are the genus Platysiphon, the family Platysiphonaceae and the order Stschapoviales.