• Applied Microscopy
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• v.30 no.1
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• pp.89-100
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• 2000

We observed the salivary ducts of two species of snails, Achatina fulica and Incilaria fruhstoferi with an electron microscope, and obtained the following results. The intralobular and interlobular ducts of Achatina fulica assume the forms of round or ellipsoidal doughnuts. The boundaries between the endothelial cells are not clear. It is also found that the cytoplasm of the endothelial cells consists of the membrane infolded in interdigital form, and there are well -developed microvilli at the apical portion of the cytoplasm. On the other hand, the intralobular and interlobular ducts of Incilaria fruhtoferi consist of the irregular simple columnar epithelia. The high electron dense cytoplasm is filled with the irregular round granules. The microvilli at the apical portion of the cytoplasm are not so well-developed as those in Achatina fulica. In the salivary duct of Achatina fulica, the lumen has narrow and long tubular structure. The boundaries between the endothelial cells are not clear. The cytoplasm is full of many vacuoles and electron lucent granules. At the apical portion of the cytoplasm, lots of short and thin microvilli are found. The salivary duct of Incilaria fruhstorferi is wider ($65\times250{\mu}m$ in diameter) than that of Achatina fulica, and consists of endothelial cells of the same structures. At the apical portion of those endothelial cells, a lot of junction apparatus such as desmosomes are observed. The vessels in the salivary ducts of Achatina fulica and Incilaria fruhstoferi are observed mainly in the connective tissues between the salivary glands. The endothelial cell of the vessel has the irregular structure and looks dark due to the high electron density. These cells protrude their filopodia and phagocytosize foreign bodies.

• The Korean Journal of Malacology
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• v.12 no.2
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• pp.109-121
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• 1996

Histochemical experiment was carry out respectively to confirm the properties of the salis (Achatina fulica and Incilaria fruhstorferi). SDS-PAGE was carried out to compare and invertigate the distribution aspects of protein patterns between the two species. Five types(A, B, F, H and I)of gland cells with four neutral mucopolysaccharide cells and one acid mucopolysaccharide cells and one acid mucopolysaccharide cell were observed in acinous of Achatina fulica, while six types were observed in acinous of Incilaria fruhstorferi: ond acid mucopolysaccharide cell(type-A) and four neutral mucopolysaccharide cells(type-B, C, D and F) and one cell that acid mucopolysaccharide is only mimbrane that surrounded granule(type-E). The results are follows:The thpe-A fland cell is commonly observed between the two species. The type-A gland cell in Achatina fulica possesses a nucleus with a developed heterdchromatin, and the cytoplasm was filled with round granules. The granules were surrounded with an uncertain boundary mimbrane and confirmed with neutral mucopolysaccharides, but is confirmed acid mucopolysaccharide in Incilaria fruhstorferi.The type-B gland cell is obwerved in the two species, too. The type-B gland cell in Achatina fulica was round shaped, and included an evenly alrge nucleus. The uncleoplasm included granules that were confirmed in the neutral mucopolysaccharides of the two species. The type-C and D gland cells exist only in Incilaria fruhstorferi, nucleoplasm was well developed heterochromatins. The type-E gland cell appears in the acinous surrounded the salivary gland of Incilaria fruhstorferi. Thdse granules appear irregular irregular shape and size and the cytoplasm is formed in alveolar. The type-F gland cells are commonly observed in the salivary glands of the two species. They are similar with the type-B gland cell, but the granular shape is comparatively small and irregular, and possess the neutral mucos granules. The type-H gland cells are mainly seen in only Achatina, and in nucleus is a well developed heterochromatin. The cytoplasm is filled with round small granules with acid mucopolysaccharide for alcianophilia observed. The type-I cell was small cell with an irregular shape and only observed in the gland cells of Achatina fulica. The heterochromatins were developed in the nucleus and the granules are not observed in cytoplasm.Secretory ducts of saliva are composed of the interlobular duct and interlobar secretory duct. In Achatina fulica the interlobular duct consists of a simple cuboidal epithelium, while the endothelium of intralobar secretory duct of Incilaria fruhstorferi consists of a simple squamous epithelium and in the cytoplasm is filled with granules(type-G secretory cell). A SDS-PAGE was carried out to confirm that the protein band pattern consist of salivary gland. In conclusions, five more bands in Achatina fulica and three bands in Incilaria fruhstorferi were confirmed in MW<29 kDa. one main band coincides comparatively with both and is between 29-45 kDa. There are four main bands in Achatina fulica and two main bands in Incilaria fruhstorferi between 45-66.5 kDa respectively. The bands in Achatina fulica seem more complex than in incilaria fruhstorferi.

• The Korean Journal of Malacology
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• v.14 no.2
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• pp.75-83
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• 1998

아프리키 왕달팽이(Achatina fulica) 외투막(mantle edge) 내 근육 속의 신경근연접에 관한 미세구조 연구결과는 다음과 같았다. 신경근연접종말의 형태는 방추형이거나 불규칙형이었으며, 연접막과 근형질막상이 연접간극(synaptic cleft)의 넓이는 30mm 정도로 나타났다. 연접강속에는 전자밀도가 높은 둥근 과립(직경 100mm)과 중등도는 과립(직경 70mm)그리고 전자밀도가 낮은 소포(직경70mm)등 3종류가 관찰되었으며, 연접종말의 외측에는 0.2 - 0.4$\mu\textrm{m}$ 정도크기의 전자밀도가 높은 둥근 과립들이 존재하였다. 전자밀도가 중등도인 둥근 과립 중 일부는 연접막 밖으로 배출(exocytosis) 되었으며, 근형질막과 연접막이 합체되는 현상도 관찰되었다. 근형질(sarcoplasm)내에서 수축성단백질인 액틴과 미오신섬유의 배열은 불규칙하였으며, 세포질성 치밀체(cytoplasmic dense body)도 관찰되었다.

• Environmental Mutagens and Carcinogens
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• v.26 no.1
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• pp.20-24
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• 2006

An antimicrobial substance was purified from the giant snail body extract (Achatina fulica) using solid-phase extraction and separation on HPLC reversed-phase chromatography. The primary structure were determined by a combination of an automated amino acid sequence and MALDI-TOF Mass. Its molecular mass was found to be 1392.64 Da. This result was in excellent agrement with the theoretical molecular mass calculated from the amino acid sequence. purified peptide showed antimicrobial activity in vitro against Escherichia coli D31. This result indicate that giant snail whole body was potentially antimicrobial.

• Applied Microscopy
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• v.30 no.4
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• pp.367-376
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• 2000

The observation using an electron microscope shows that the maturation of the oocyte of African giant snail, Achatina fulica, proceeds over three stages. The oocyte of stage 1 is a small elliptic cell $(220\times400{\mu}m)$ whose light nucleoplasm contains two nucleoli. In its cytoplasm, a number of mitochondria, rough endoplasmic reticula, and ribosomes are found, while yolk granules are not. The nucleus of the oocyte of stage 2 is relatively large in comparison with the volume of cytoplasm, and contains one nucleolus. In the nuclear envelope comprising inner and outer double membrane, there are found a lot of nuclear pores for materials to pass through. A number of mitochondria, Golgi complex and lipid yolk granules appears in the cytoplasm, and proteinous yolk granules begin to form and mature in the vacuoles of various sizes ($0.8\sim3.0{\mu}m$ in diameter). The oocyte of stage 3 has an enlarged nucleolus. Material transportation through nuclear pore is not found any longer. The cytoplasm in this stage is filled with proteinous and lipid yolk granules. The microvilli are developed around the egg plasma membrane.

• Proceedings of the Malacological Society of Korea Conference
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• 1999.11a
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• pp.7-8
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• 1999

• Archives of Pharmacal Research
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• v.25 no.6
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• pp.889-894
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• 2002

Acharan sulfate (AS) is a glycosaminoglycan (GAG) prepared from the giant African snail, Achatina fulica. In this study, some biological activities of AS were evaluated on the basis of structural similarities to heparin/heparan sulfate and the biological functions of GAGs. We demonstrated that it exhibited strong immunostimulating activities as measured by carbon clearance test in mice and in vivo phagocytosis. It also exhibited a significant hypoglycemic activity in epinephrine (EP)-induced hyperglycemia as well as antifatigue effects by weight-loaded forced swimming test. And it showed hypolipidemic activities in cholesterol-rich mixture induced hyperlipidemia in rats. The above results indicate that AS has diverse biological activities and suggest therapeutically important target molecules.

• Journal of the Korean Wood Science and Technology
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• v.43 no.5
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• pp.628-640
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• 2015

Cellulase is the key enzyme in the use of cellulose-based biomaterials. Because of its structure, cellulose is difficult to be degraded by enzymes. In order to utilize cellulose-based biomaterials efficiently, evolutionary wisdom of how to use enzymes accurately and harmoniously in a biological system is needed, such as the cellulose digestive system in animals. In this study, the symbiotic bacteria from snails, Achatina fulica, were identified and their cellulase activity was evaluated. The 16S rRNA sequence analysis of 100 aerobic bacteria showed that they belonged to 9 genus and almost half of the bacteria were Lactococcus spp. Among 100 identified strains, only two Aeromonas sp. strains showed cellulase activity. Aeromonas sp. KMBS020 had both endo-${\beta}$-glucanase and ${\beta}$-glucosidase activities but Aeromonas sp. KMBS018 had ${\beta}$-glucosidase activity only. None of the 100 bacterial colonies had any cellobiohydrolase activity.

• Applied Microscopy
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• v.28 no.4
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• pp.513-525
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• 1998

The spermatogenetic process in the edible giant snail is similar to those in the other snails, except for the axoneme formation process. In this study, the axoneme formation process in the giant snail was mainly examined by means of electron microscopy. The tail portion of a spermatozoon is about $160{\mu}m$ long, and extends straight to the rear, surrounded by two large and long mitochondria in spiral forms. A number of glycogen particles $(40\sim70nm)$ are found in the swollen matrix of the mitochodria. The axoneme which composes the tail of a spermatozoon is surrounded by $7\sim10$ lamella-form fibrous sheaths of about $0.2{\mu}m$ in thickness. Most of the mature spermatozoa are found to be clustered into a group of $5\sim7$ ea in syncytial bridges formed by cytoplasmic processes. Sertoli cells contain glycogen particles, endoplasmic reticulum, a lot of mitochondria, and lipids in their cytoplasm. They protrude their filiform pseudopodia and phagocytize abnormal spermatids or spermaozoa.

• The Korean Journal of Malacology
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• v.15 no.1
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• pp.1-11
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• 1999

An immunohisochemical study on the cerebral ganglion of the African giant snail, Achatina fulica. was conducted by applying the AB/AY staining and the avidin-bovine-peroxidase complex staining methods. The followings are the results obtained throughout the study. The cerebral ganglion of Achatina fulica is an ellipsoidal body of 2 x 1 mm in size, which is connected by the cerebral commissure of 1 mm in diameter. The cross-section through the cerebral ganglion, shaped like a butterfly, is divided into the medio-dorsal parts, the latero-dorsal parts, the caudo-dorsal parts, and the lateral lobes. In the medio-dorsal and latero-dorsal parts, the LG cells and the DG cells are found mixed, although the LG cells are dominant. In lateral lobe, however, the Y cells are quite dominant, while the LG cells and the DG cells are seldom found. The LG cells are 20-70 $\mu\textrm{m}$ in sizes and circular or ellipsoidal in shapes. They are stained light green with the AB/AY. 1 - 3 nucleoli are found in karyolymph, where granular chromantins are evenly distributed. In cytoplasm, it is found that the secretory granules are evenly developed.