• Environmental Analysis Health and Toxicology
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• v.14 no.1_2
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• pp.55-63
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• 1999

Endocrine disrupting chemicals probably cause the cytological or/and morphological changes of germinal cells in gonad. Accordingly, this study was aimed to make sure that the effect of hormone-mimicking chemicals on gonad morphology such as decrease of germinal cells, inhibition of cellular maturation and change in the ratio of germinal cells in the different developmental phase can be observed by histopathological procedures and can be a useful bio-indicator for the evaluation of endocrine disruption by environmental chemicals. In this experiment, female Japanese medaka were exposured to quercetin, a phytoestrogen, at the concentration of 100 $\mu\textrm{g}$/L. quercetin showed the significant decrease in the number and rate of vitellogenic follicular oocytes in the treated group for 4 and 6 weeks. The weak development of yolk could be also observed. We could conclude that quercetin has anti-estrogenic or androgen-like potency by exerting the inhibition effect on oogenesis in fish female- gonad. From the result of this study, the applied methods and techniques can be evaluated to be a useful biomonitoring means for water pollution, expecting a good result of the subsequent study on apoptosis.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.890-893
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• 2001

Zeta potential measurement not only can provide surface information on colloidal biomaterials but more importantly can be used in bioprocess control and products quality control. In this study, zeta potentials for intracrystalline proteins of each layers from oyster shell prepared in 1mM NaCl at different pH were measured. Also, in forming calcite crystals with intracrystalline proteins as an additive extracted from oyster shell, the zeta potentials were measured. These studies were performed to verify the primary role of intracrystalline proteins in controlling the formation, morphological development and crystallography of the biocomposite.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.10a
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• pp.134-135
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• 2003

The insect cuticle undergoes drastic morphological alterations during postembryonic development and is an extracellular structure composed mainly of chitin and proteins that are synthesized and secreted by epidermal cells. Cuticle proteins, the major components of insect integument, are recently being focused as a model fur studying the mechanisms of gene regulation during molting and metamorphosis. (omitted)

• Development and Reproduction
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• v.1 no.2
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• pp.133-139
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• 1997

To study the function and structure of Golgi apparatus in the spermiogenesis of long-fingered bat (Miniopterus schreibersi fuliginosus), the testis obtained from adult bat was treated with the prolonged osmification or fixed with ferrocyanide reduced osmium. golgi apparatus was oval shape in early Golgi phase, and was composed of cortex and medullar enclosing acrosome in mid Golgi phase. The vesicles of crescent shape Golgi apparatus were closed or fused with small or large vesicles at the periphery of acrosome. Golgi apparatus moved behing the acrosome face in cap phase, but the Golgi apparatus was still active. According to this, Golgi apparatus appears to be involved in the formation of acrosome and sperm tail. Transfer of materials from Golgi to acrosme seems to be carried out not only by fusion of large vesicles with acrosomal vesicles but also by detachment of coated vesicle from various cisternae of Golgi fusing with acrosomal vesicle.

• Development and Reproduction
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• v.1 no.2
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• pp.125-132
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• 1997

To investigate the cadmium (Cd) toxicity on the testis, male rats were treated with 1, 2, 4 and 8 mg/kg of Cd by IP. According to histochemical studies, Cd-treated testis tissue showed death of spermatozoa, death of Sertoli cells, death of all the spermatogenic cells, and finally disappearance of basal lamina of seminiferous tubules with increasing doses, and showed decreased ground substances and Leydig cells, increased inflammatory cells and fibroblasts, and fibroblasts, and finally disappearance of ground substances and all the cells except fibroblasts within interstitial tissues with increasing doses. According to biochemical studies, two kinds of proteins, 25 and 45 kDa, were dramatically disappeared from the total protein of rat testis treated with Cd comparing to normal testis. The result of electrophoresis of total protein suggests that actin (45 kDa), presumed on its mmolecular weight and amount, in the testis-cells is the primary target of Cd poisoning. Although its exact mechanism is not clear, the disappearance of two proteins when testis is exposed to Cd should give some clues to understnad the mechanism of necrosis of testis tissue crumbling by heavy metal pollutant such as Cd.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.269-272
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• 2002

The technical development of nonwoven industries for past 30 years with economic growth has contributed to create new end-use covered the wide field of industries. Recently, new concept of textile technology has studied and developed for cost reduction of production and high added value of products. Whereas the structure of nonwovens produced by conventional production methods have various pore size, and it is not suitable to filtrate gas and small powder particles. (omitted)

• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.230-233
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• 1998

Acetic acid producing bacteria were isolated from deastringent persimmon vinegar and the major bacterium was identified using morphological and biochemical tests. Acetobacter sp. AH-1 was motile, gram negative rod with catalase positive and oxidase negative. The strain can grow up to 5 % ethanol and 2% NaCl as well as 25% glucose. Optimum temperature and pH for growth were 3$0^{\circ}C$ and 5.0, respectively. Volatile constituents of persimmon vinegar were analyzed by purge and trap sampling . Acetic acid adn alcohol were the largest volatile compounds quantitiatively in persimmon vinegar. Among alcohols, 20methyl-1-propanol, isoamyl alcohol and amyl alcohol were detected. Isovaleradehyde and benzaldehyde for aldehyde, isoamyl acteate, ethyl formate, propyl aceetate, and ethyl acetate for esters were likely to contribute to persimmon vivegar flavor.

• Development and Reproduction
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• v.17 no.2
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• pp.87-97
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• 2013

The seminiferous epithelium cycle and developmental stages of spermatids in Clethrionomys rufocanus were observed under a light microscope. The seminiferous epithelium cycle was divided into 8 stages. Type Ad spermatogonia appeared through all stages. Type Ap, In, and B spermatogonia appeared in stages I, II, III, and IV. In the first meiosis prophase, the leptotene spermatocytes appeared from stage V, the zygotene spermatocytes in stages I, VI, VII, VIII, the pachytene spermatocytes from stages II to VI, the diplotene spermatocytes in stage VII. The meiotic figures and interkinesis spermatocytes were observed in stage VIII. Developing spermatids were subdivided into 10 steps, based on the morphological characteristics such as the acrosome formation changes in spermatozoa, nucleus, cytoplasm, and spermiation changes. The C. rufocanus spermatocytogenesis and spermiogenesis results displayed similar results with Apodemus agrarius coreae and A. speciosus peninsulae. Considering all the results, the spermatogenesis may be useful information to analyze the differentiation of spermatogenic cells and the breeding season.

• Journal of Embryo Transfer
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• v.25 no.1
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• pp.85-87
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• 2010

A necropsy of a primiparous, 4-year-old, Himalayan tahr (Hemitragus jemlahicus) was performed in September 8, 2009. Typical appearances of ovaries, oviducts, uterine horns, cervix and caruncles were well shown. Five cervical folds were present in the cervix. Cervical opening can be reached in the length of less than 15 cm from the entrance of vagina. Development of two follicles was found in the left ovary even though breeding season of this species naturally starts in late November. The reproductive organs of a primiparous, 3-year-old, Corriedale sheep showed that differences in the length and morphological appearance of cervix exist between two species. Comparative understanding of reproductive systems in Himalayan tahr and Corriedale sheep could help advancing assisted reproductive technologies in feral goats.

• Journal of fish pathology
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• v.17 no.3
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• pp.179-189
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• 2004

Morphological structure and sporogenesis of myxosporean parasite, Parvicapsula anisocaudata from cultured olive flounder, Paralichthys olivaceus were examined by light and transmission electron microscopies. Numerous round early stages, spindle-shaped disporic or monosporic pseudoplasmodia, asymmetrical thin-walled mature spores were found inthe lumen of renal tubule and urinary bladder. Long pseudopodia or short projections from cytoplasm of pseudoplasmodia make the parasite attach firmly to host tissues. Spore development was mono- or disporous with no pansporoblast formation. Sporoplasmic cell was partially surrounded by two capsulogenic cells, and capsulogenic cells were enveloped by two flattened valvogenic cells. Capsulogenesis and valvogenesis followed general patterns seen in that of other myxosporean.