• 한국환경과학회지
• /
• 제22권3호
• /
• pp.371-378
• /
• 2013

After identifying species by collecting the suspended and attached algae mat inhabiting in the slow sand-filter, Spirogyra sp., Mougeotia sp. and Closterium sp. were main green algae and Synedra sp. was diatom algae. Among them green algae Spirogyra sp. was dominant species. A result of observing the life mode of apple snail for a month after introducing into the slow sand-filter, apple snail eggs were discovered on the filter walls 2 weeks after introducing, 4 weeks later lots of eggs were observed all of the slow sand-filter walls, it means there is no problem for apple snail to live in the slow sand-filter. The observation result for algae removal potential by introduced apple snail after 2 months later, slow sand-filter where apple snail were introduced, a few algal mat were observed. On the other hand, no introduced apple snail into the slow sand-filter, lots of suspended algal mats were formed in the water and attached algal mats on the sand surface as well, these algal mat induced much of operating problems.

• 한국유기농업학회지
• /
• 제8권2호
• /
• pp.79-87
• /
• 2000

This experiments was carried out to find the effect of different organic farming types, the Duck-pasture plot, the Pond-snail pasture plot andd control of the conventionalculture plot farming on the yield and its components of paddy rice. The results obtained are summarized as follows. Plant height an Tillering were significantly increase in the Duck-pasture plot. Panicle number pr hill, NO. of grain per spike and 1,000grain weight were significantly increase in the conventional culture plot. Yield pre 10a were 574.13kg at pond-snail pasture plot, 576.81kg at Duck-pasture plot and 579.04kg at conventional culture plot. From these results, it seems that the organic farming are useful and pasture of the Duck, Pond-snail for depression of the weed occurrence or increase of yield per 10a is effective as the environmental perservation farming.

• BMB Reports
• /
• 제50권12호
• /
• pp.599-600
• /
• 2017

Many studies have focused on the tumor suppressive role of $TGF-{\beta}$ signaling during the early stages of tumorigenesis by activating the target genes involved in cytostasis and apoptosis. We investigated the effects of $TGF-{\beta}$ inhibition on early tumorigenesis in the liver, by employing diverse inhibitory methods. Strikingly, $TGF-{\beta}$ inhibition consistently suppressed hepatic tumorigenesis that was induced either by activated RAS plus p53 downregulation or by the co-activation of RAS and TAZ signaling; this demonstrates the requirements for canonical $TGF-{\beta}$ signaling in tumorigenesis. Moreover, we found that Snail is the target gene of the $TGF-{\beta}$ signaling pathway that promotes hepatic carcinogenesis. The knockdown of Snail suppressed the early tumorigenesis in the liver, as did the $TGF-{\beta}$ inhibition, while the ectopic expression of Snail restored tumorigenesis that was suppressed by the $TGF-{\beta}$ inhibition. Our findings establish the oncogenic $TGF-{\beta}$-Smad-Snail signaling axis during the early tumorigenesis in the liver.

• 한국식품영양과학회지
• /
• 제23권3호
• /
• pp.453-458
• /
• 1994

체색이 다른 세종류(백색육, 황색육, 회색육)의 식용 달팽이(Giant snail, Achatine fulica)의 일반성분과 무기질을 정량하여 이의 식품학적 가능성을 예측하였으며, 효소를 이용한 단백소화율(in vitro protein digestibility), 단백효율비(C-PER, computed protein efficiency ratio) 및 typsin inibitor 함량을 측정하여 이의 단백질 품질을 평가하였다. 또한 전처리 및 가공조건을 달리한 달팽이 제품의 단백질 품질을 측정하여 바람직한 처리조건을 찾으려 했으며, 달팽이육 중에 다량 포함되어 있는 점액성 물질이 다른 단백질의 소화율에 미치는 영향도 아울러 실험하였다. 1. 식용왕달팽이의 가식부는 39% 정도로서 해산패류보다 10%정도 높았으며 가식부 100g당 11.5~13.7%의 단백질, 0.9~1.3%정도의 지질이 함유되어 있다. 무기질로서는 칼슘, 칼륨 및 마그네슘이 풍부하였고 특히 칼슘함량은 굴(oyster)에 비교하여 5~10배 높았다. 2. 아미노산의 함량과 그 조성은 백색육, 회색육, 황색육이 모두 비슷하였고, 주요 아미노산은 aspaltic acid, glutamic acid, proline과 glycine으로 총아미노산의 52.5%를 차지하였고 특히 필수아미노산 함량이 총아미노산의 45~46%를 차지하여 균형잡힌 단백질로 판별되었다. 3. 생달팽이육의 단백질 소화율은 76.6%(회색육)~81%(황색육과 백색육)였으며 단백효율비는 2.24(백색육)~2.36(황색육) 범위였으나, trypsin inhibitor함량은 체색에 따라 다양하였다(백색윤 22.7mg/g solid, 회색육 28.97mg/g solid 및 황색육 36.75mg/g solid). 4. 10% 식염수에 5분간 침지한 후 10분간 boiling한 달팽이육의 소화율은 생육에 비해 1.7%(백색육)~5.7%(회색육)로 증가하였고, trypsin inhibitor 함량은 12.62mg/g solid (백색육)과 16.40mg/g solid (회색육)로 크게 감소하였으며, C-PER은 가공조건에 따라 변동이 없었다. 5. 생달팽이육에 다량 함유된 점액성물질은 여러가지 단백질의 소화율 2% (ANRC casein)~11%(filefish protein)로 감소시켰다.

• 한국수산과학회지
• /
• 제36권5호
• /
• pp.454-457
• /
• 2003

A feeding trial was carried out to investigate the utilization of dietary soybean meal and wheat flour as substitutes for fish meal and alginate in different dietary types (powder, pellet and flake) for juvenile snail (Semisulcospira gottschei). After 10 weeks feeding trial, survival was not affected by formulation and type of diets (P>0.05), but weight gain was significantly affected by dietary formulation (P<0.001) and type (P<0.05). In the same dietary formulation, weight gain of the snail fed the flake type of diets was lower than that of the snail fed the powder or pellet types. However, the type of diet did not affect weight gain when snail fed diets containing $37\%$ soybean meal and $18\%$ alginate. The weight gain was lower in the snail fed diets containing $25\%$ fish meal compared with that of the snail for diets containing $33-37\%$ soybean meal at the same dietary type. When soybean meal was used as main protein source in diets, weight gain was not affected by dietary alginate $(0\;and\;18\%)$ and wheat flour $(36\;and\;58\%)$ contents. Crude protein and ash contents of whole body of the snail was not affected either by formulation or by type of diet. Moisture and crude lipid contents of the whole body were significantly affected by dietary formulation, but not by the type. These results indicate that $25\%$ fish meal could be replaced by $37\%$ soybean meal as dietary protein source, and pellet and powder could be desirable dietary type for the optimum growth of the snail.

• Parasites, Hosts and Diseases
• /
• 제56권3호
• /
• pp.247-257
• /
• 2018

The aim of this study was to conduct a freshwater snail survey in Mae Lao agricultural basin to assess the diversity with a focus on habitat types and their larval trematode infections. Snails were collected and examined in 14 sites of Mae Lao agricultural basin from August 2016 to October 2017. A total of 1,688 snail individuals were collected and classified into 7 families, 8 genera, and 12 species. Snail diversity and habitat types were higher in rice paddies than irrigation canals and streams. The most abundant species was Bithynia siamensis siamensis, representing 54.6% of the sample. Three species of snails act as first intermediate host were found with cercarial infections. They were Filopaludina sumatrensis polygramma, B. s. siamensis, and Melanoides tuberculata. The cercariae were categorized into 7 types; echinostome, monostome, gymnocephalous, virgulate, parapleurolophocercous, pleurolophocercous and megalurous cercariae. Parapleurolophocercous cercariae constituted the most common type of cercariae recovered, contributing 41.2% of all infections in snails. Echinostome metacercariae infections were found in 6 snail species with 7.6% prevalence. In addition, the metacercaria of avian trematode, Thapariella sp. were found in Filopaludina spp. snails and B. funiculata with a prevalence of 0.5%. This is the first report for Thapariella metacercariae in the snail host, B. funiculata, and also confirmed that viviparid and bithyniid snails act as the second intermediate hosts of this trematode. This work will provide new information on the distribution and intermediate host of trematode in this area.

• 생명과학회지
• /
• 제23권8호
• /
• pp.970-977
• /
• 2013

Epithelial-to-mesenchymal transition (EMT)는 embryogenesis에서 중요한 역할을 하며 tumor metastasis, invasion에도 관여함으로써 tumor progression 및 aggressiveness에 기여한다. EMT는 EMT hallmark인 epithelial E-cadherin의 발현 감소와 mesenchymal-like cell morphology를 획득함으로써 epithelial cell polarity를 잃어버리는 특징을 가지고 있다. $O_2{^-}$, $H_2O_2$, $OH^-$와 같은 활성산소가 EMT를 유도하는 것으로 알려져 있다. Snail이 E-cadherin의 발현을 억제함으로써 ROS에 의한 EMT에 관여하는 것으로 알려져 있으나, 그 기작은 완전히 밝혀져 있지 않다. 본 연구에서는, noninvasive breast tumor cell line인 MCF-7 세포에 Egr-1을 과발현시킨 후 그 영향을 조사하였다. Egr-1이 과발현되면, MCF-7 세포는 epithelial cell polarity를 잃고 spindle-shaped로 변화되므로, Egr-1이 EMT를 유도할 가능성이 대두되었다. 또한 Snail이 Egr-1에 의한 EMT에 관여함을 확인하였다. 나아가, 본 연구진은 Egr-1-Snail axis가 ROS에 의해 활성화 되고, ROS에 의한 EMT에서 중요한 역할을 함을 발견하였다.

• 대한지역사회영양학회지
• /
• 제11권5호
• /
• pp.650-660
• /
• 2006

Recently, according to increase in production of pond snails resulting from the widespread organic farming, organic farmers are showing a lot of interests in the promotion of consumption and extending the market of pond snails. This study was performed to suggest the process of product development of the ready-to-eat pond-snail Mandu as a health food, to show the results of market test of the pilot product, and to investigate the change of the sensory characteristics during storage periods. For the market test of pond-snail Mandu, the survey was developed and delivered to consumers. The questionnaire consisted of 3 parts such as respondents demographic characteristics, customer's perception of pond-snail Mandu before tasting, and customer's perception of that after tasting. And the market test was carried out with university students, welfare institution residents and apartment residents in the Seoul and Gyeonggi areas. As a result of the test, the most important purchasing factors were determined in the order of taste (49.5%), hygienic quality (12.5%), nutritional value (10%) and price (9%). And only 4.2% of respondents selected brand name as an important purchasing factor. After tasting pond-snail Mandu, consumers had suggested the better taste (t=6.986, p<0.000) and price (t=2.082, p<0.05) than those of before tasting. In response to favorable impression of pond-snail Mandu, 54.5% of total respondents evaluated positively. The favorable impressions came from iron-rich Mandu (27.6%), high protein and nutritious Mandu (24.4%), calcium-rich Mandu (17.9%), diet Mandu (13.3%), and delicious Mandu (12.5%) respectively. Sensory characteristics of pond-snail Mandu were evaluated by professional panels in terms of the softness of Mandu skin, chewiness, moistness, toothpacking, color, aroma, saltiness, and degree of plain, taste, and aftertaste. The evaluation of sensory characteristics on a 7-point scale, showed that softness of mandu skin (4.44) and aftertaste (4.11) got a low scores. The statistical difference of the tastes (p>0.05) was not founded by storage period of 7, 14, 21 and 28 days. Based on the result, the improvement of these characteristics are desired in developing the pond-snail Mandu. Research method applied to this study can be useful for developing a new product.

• BMB Reports
• /
• 제51권9호
• /
• pp.456-461
• /
• 2018

Chemoresistance is a major barrier to successful cisplatin-based chemotherapy for epithelial ovarian cancer (EOC), and emerging evidences suggest that microRNAs (miRNAs) are involved in the resistance. In this study, it was indicated that miR-363 downregulation was significantly correlated with EOC carcinogenesis and cisplatin resistance. Moreover, miR-363 overexpression could resensitise cisplatin-resistant EOC cells to cisplatin treatment both in vitro and in vivo. In addition, data revealed that EMT inducer Snail was significantly upregulated in cisplatin-resistant EOC cell lines and EOC patients and was a functional target of miR-363 in EOC cells. Furthermore, snail overexpression could significantly attenuate miR-363-suppressed cisplatin resistance of EOC cells, suggesting that miR-363-regulated cisplatin resistance is mediated by snail-induced EMT in EOC cells. Taken together, findings suggest that miR-363 may be a biomarker for predicting responsiveness to cisplatin-based chemotherapy and a potential therapeutic target in EOC.

• Fisheries and Aquatic Sciences
• /
• 제14권4호
• /
• pp.411-416
• /
• 2011

We investigated the nutritional status of the melania snail (Semisulcospira gottschei) using RNA/DNA ratios to evaluate the effect of feeding conditions (artificial versus natural) on the reaction times of the snails in a time course following starvation. In the short experiments (48 h), the RNA/DNA ratios of the artificial feeding groups were significantly higher than those of the natural groups. While two RNA/DNA ratio peaks were observed in the artificial food group during daytime, the natural food group showed a higher ratio at night. Under starvation conditions, the RNA content decreased whereas the DNA content was constant. The RNA/DNA ratios of the freshwater snail in both groups dramatically decreased after starvation and remained constant until the end of the experiment. We verified that the RNA/DNA ratio serves as an index of nutritional condition with respect to the effect of dietary differences. These results are important for understanding optimized aquaculture rearing conditions for this important commercial freshwater snail.