OBJECTIVETo explore a new technique to prevent the dispersal of Oncomelania hupensis snail through leading flood for irrigation by floodgate in irrigation schemes.

METHODSHydromechanical and biological were applied and to combine laboratory experiment with the field observation to form a new multidisciplinary regarding snail biological hydraulics and technical line. Findings including characteristics of hydraulics and biomechanics and move regulation etc. Physics parameter of snails were used to design and construct as well as to exam the effect of facilities and rebuilt floodgate which could prevent the snail dispersal.

RESULTSThrough five years efforts, the major achievements were found as: 1) the method in testing the special gravity of snail and snail eggs was determined. 2) the special gravity of snail was (1.8 +/- 0.01) g/cm(3) and special gravity snail eggs was (2.29 +/- 0.01) g/cm(3); the classification method and classified criterion of snail size were made based on geometrical characteristics of snail shell. Six special values indicating dropping and start speed of snail in running water were obtained; Five practical formula of snail dropping and start in water were established; threshold value and movement characteristics in water were observed and tested and move mechanism of snail dispersal in water was also clarified. Based on the findings from fundamental research, the facilities of "precipitation pool for snail" and "leading water from middle level of water body" that could prevent snail dispersal were designed and rebuilt in the endemic area. Through examination to these facilities, the rate of precipitating and blocking of snails reached 100%.

CONCLUSIONThe achievement of the study provided reliable theoretical basis for the rebuilt of floodgate and to development of models that could prevent the dispersal of snail effectively.

Agriculture ; Animals ; Disease Vectors ; Schistosomiasis ; prevention & control ; transmission ; Snails ; growth & development ; Specific Gravity

OBJECTIVETo investigate the epidemiological situation of cercarial trematodes infection in freshwater snails from different water resources in Chiang Mai province, Thailand.

METHODSThe snail specimens were collected from 13 districts of Chiang Mai province during April 2008 to February 2012. The prevalence of cercarial infection in snails was investigated using the crushing method. The drawing was done with the help of a camera lucida for the morphological study.

RESULTSA total of 2 479 snail individuals were collected and classified into 7 families, 11 genera, and 14 species, Among them, 8 snails species were found to be infected with an overall prevalence of 17.27% (428/2 479), which infected with nine groups of cercariae; gymnocephalous cercaria, strigea cercaria, megalurous cercaria, monostome cercaria, parapleurolophocercous cercaria (Haplorchis cercaria), pleurolophocercous cercaria, furcocercous cercaria (Transversotrema cercaria), xiphidiocercaria, and virgulate cercaria. The parapleurolophocercous cercaria was found to be the dominant type among the cercarial infection in the snails (64.25%).

CONCLUSIONSThe various species of snails found in the research location act as the intermediate hosts for the high prevalence of parasitic infection of many species of mammals. This work will provide new information on both the distribution and first intermediate host of trematodes.

Animals ; Cercaria ; growth & development ; isolation & purification ; Fresh Water ; Prevalence ; Snails ; parasitology ; Thailand ; epidemiology ; Trematoda ; growth & development ; isolation & purification

OBJECTIVETo research molluscicidal effect activity, active components and stable passage of endophyte JJ18 from Pseudolarix amabilis and examine the possibility for practical application.

METHODMolluscicidal effect test was performed according to the immersion test method suggested by WHO.

RESULTImmersion test with JJ18 broth showed that the active components were extracellular moiety of the broth and that 10% concentration solution could kill nearly 90% snail immersed after 72 h, the salified broth has favourable thermostabily and photostability and showed that JJ18 has stable passage and its active components concentrate in the extract of n-butanol.

CONCLUSIONThe metabolite of endophyte JJ18 has activity for molluscicidal effect and potential for application.

Animals ; Bacteria ; chemistry ; growth & development ; Bacterial Proteins ; pharmacology ; Molluscacides ; chemistry ; pharmacology ; Pinaceae ; microbiology ; Polysaccharides, Bacterial ; pharmacology ; Snails ; drug effects

OBJECTIVETo construct the life cycle of Angiostrongylus cantonensis (A.cantonensis) in laboratory condition.

METHODSSD rats were infected orally with the third-stage larvae of A.cantonensis collected from Jiangmen, Guangdong province. Six weeks after infection, the first-stage larvae were isolated from fresh feces of the rats by using Baermann funnel to infect 25 second-generation white jade snails raised in laboratory at the daily dose of 300 000 for 3 consecutive days. Three weeks later, the snails were dissected for counting the third-staged larvae of A.cantonensis, and those positive for A.cantonensis infection were fed directly to 10 fasting rats. The serum samples of the rats were then collected 2 weeks later for examination of specific antibodies using ELISA. The feces of the infected rats were examined microscopically after 6 weeks, and the brain, heart and lungs of the infected rats were dissected to observe the larvae at 3, 5, and 8 weeks, respectively.

RESULTSThe 3-stage larvae of A.cantonensis were found in the second-generation snails 3 weeks after infection. The positivity rate of serum specific antibodies was 100% in the 10 rats 2 weeks after feeding of the infected snails. The 1-stage larvae were detected in the feces of the rats 6 weeks after infection, and the fourth-stage larvae were found in the brain of the rats at 3 weeks, while adult worm and eggs were found in the heart and lungs of the infected rats at 5 and 8 weeks.

CONCLUSIONThe successful establishment of human colon carcinoma cell line with PRL-3 gene knock-down provide a basis for investigation of the role of PRL-3 gene in the metastasis of human colorectal carcinoma.

Angiostrongylus cantonensis ; growth & development ; physiology ; Animals ; Disease Vectors ; Larva ; growth & development ; physiology ; Life Cycle Stages ; Rats ; Rats, Sprague-Dawley ; Rodent Diseases ; parasitology ; Snails ; parasitology

We detected metacercariae of Echinostoma revolutum in Filopaludina sp. snails purchased from a local market in Nam Dinh Province for the first time in Vietnam. Adult flukes were harvested from experimentally infected hamsters at days 14 and 17 post-infection. The metacercariae were round, 170-190 microm (n=15) in diameter, with a cyst wall thickness of about 12 microm. A total of 37 collar spines were arranged around the head collar, and large excretory granules were seen in 2 canals of the excretory bladder. The 14-day old adult flukes were elongated, ventrally curved, and 5.0-7.2x0.8-1.3 mm (n=20). The head collar had a total of 37 collar spines arranged in 2 alternating rows, including 5 corner spines on each side. The cirrus sac contained a saccular seminal vesicle, a prostatic gland, and an unarmed cirrus. Two tandem testes were smooth or slightly lobed. Eggs were ovoid to elliptical, 110-118x70-75 microm. These morphological characters were similar to those of E. revolutum and E. jurini. We tentatively identified it as E. revolutum because the validity of E. jurini remains to be elucidated. The taxonomic relationship of E. revolutum and E. jurini is discussed.
Animals ; Cricetinae ; Echinostoma/anatomy & histology/classification/growth & development/*isolation & purification ; Echinostomiasis/*parasitology ; Female ; Metacercariae/anatomy & histology/classification/growth & development/isolation & purification ; Snails/*parasitology ; Vietnam

OBJECTIVETo analyze the relationship between the normalized difference vegetation index (NDVI) and the snail distribution in marshland of Jiangning county in Jiangsu province, and to explore the utility of Terra-MODIS image map in the small scale snail habitats surveillance.

METHODSNDVI were extracted from MODIS image by vector chart of the snail distribution using ArcView 8.1 and ERDAS 8.5 software. The relationship between NDVI and the snail distribution were Investigated using Bivariate correlations and stepwise linear regression.

RESULTSThe snail density on marshland was positively correlated with the mean NDVI in the first ten-day of May and the maximum NDVI (N(20max)) in the last ten-day of May. Incidence of pixel with the live snail on marshland was positively correlated with the mean NDVI (N(2mean)) in the first ten-day of May. An equation Y(1) = 0.009 47 x N(20max) (R(2) = 0.73), Y(2) = 0.018 6 x N(2mean) (R(2) = 0.906) was established.

CONCLUSIONThis study showed that the Terra-MODIS satellite images reflecting the status of the vegetation on marshland in Jiangning county could be applied to the study to supervise the snail habitat. The results suggested that MODIS images could be used to survey the small scale snail habitats on marshland.

Animals ; Breeding ; China ; epidemiology ; Ecology ; Environmental Monitoring ; Epidemiological Monitoring ; Humans ; Satellite Communications ; Schistosomiasis japonica ; epidemiology ; transmission ; Seasons ; Snails ; growth & development ; parasitology ; physiology

The small GTP-binding protein Rab25 is associated with tumor formation and progression. However, recent studies have shown discordant effects of Rab25 on cancer cell progression depending on cell lineage. In the present study, we elucidate the underlying mechanisms by which Rab25 induces cellular invasion. We demonstrate that Rab25 increases β1 integrin levels and subsequent activation of EGFR and upregulation of VEGF-A expression, leading to increased Snail expression, epithelial-to-mesenchymal transition and cancer cell invasiveness. Strikingly, we identify that Snail mediates Rab25-induced cancer cell invasiveness through fascin expression and that ectopic expression of Rab25 aggravates metastasis of ovarian cancer cells to the lung. We thus demonstrate a novel role of a β1 integrin/EGFR/VEGF-A/Snail signaling cascade in Rab25-induced cancer cell aggressiveness through induction of fascin expression, thus providing novel biomarkers and potential therapeutic targets for Rab25-expressing cancer cells.
Biomarkers ; Cell Lineage ; Ectopic Gene Expression ; GTP-Binding Proteins ; Lung ; Neoplasm Metastasis ; Ovarian Neoplasms ; Snails ; Up-Regulation ; Vascular Endothelial Growth Factor A

OBJECTIVETo explore the vegetation landscapes in marshland snail habitats using satellite image.

METHODSThe false-color composition image from band 2, 3 and 4 of LANDSAT ETM + images was classified in the ERDAS IMAGINE 8.5 to analyze the vegetation types in the marshland of Jiangning county, using the unsupervised classification. The efficiency of classification was evaluated by the transformed divergence. The overlaid layers of the classified vegetation image and the vector layer of snail habitats distribution were used to analyze the relationship between the snail distribution and the landscape types.

RESULTSThe land-cover of marshland in LANDSAT ETM234 image in Jiangning county could be classified into 10 types, including water, bare soil, sandy and other landscapes while the transformed divergence analysis showed that there were misclassified pixes between some types especially for the non-continuous types. The study indicated that through adding the NDVI image in the process of classification efficiency of classification and eliminate misclassification in the non-continuous type could be improved. Analysis on the overlaid layer of the vector of snail distribution and the classified image proved that the vegetation covers in marshland snail habitats in Jiangning mainly belonged to type 3, 5 and 6, that responded to the beach with sparse vegetation, exuberant weed and bulrush respectively. The density of snails in the bulrush was higher than that in other 2 landscapes.

CONCLUSIONThe vegetation type in the marshland snail habitats could be distinguished from the satellite image, which was helpful for the surveillance of snail habitat in marshland and for the prevention of schistosomiasis.

Animals ; Breeding ; China ; epidemiology ; Disease Vectors ; Ecology ; Environmental Monitoring ; Epidemiological Monitoring ; Humans ; Plants ; Satellite Communications ; instrumentation ; Schistosoma japonicum ; classification ; growth & development ; Schistosomiasis japonica ; epidemiology ; transmission ; Snails ; growth & development ; parasitology ; physiology

Fasciola hepatica is a trematode that causes zoonosis mainly in cattle and sheep and occasionally in humans. Fascioliasis has been reported in Korea; however, determining F. hepatica infection in snails has not been done recently. Thus, using PCR, we evaluated the prevalence of F. hepatica infection in snails at 4 large water-dropwort fields. Among 349 examined snails, F. hepatica-specific internal transcribed space 1 (ITS-1) and/or ITS-2 markers were detected in 12 snails and confirmed using sequence analysis. Morphologically, 213 of 349 collected snails were dextral shelled, which is the same aperture as the lymnaeid snail, the vectorial host for F. hepatica. Among the 12 F. hepatica-infected snails, 6 were known first intermediate hosts in Korea (Lymnaea viridis and L. ollula) and the remaining 6 (Lymnaea sp.) were potentially a new first intermediate host in Korea. It has been shown that the overall prevalence of the snails contaminated with F. hepatica in water-dropwort fields was 3.4%; however, the prevalence varied among the fields. This is the first study to estimate the prevalence of F. hepatica infection using the vectorial capacity of the snails in Korea.
Animals ; Base Sequence ; DNA, Helminth/chemistry/genetics ; DNA, Ribosomal Spacer/chemistry/genetics ; Fasciola hepatica/anatomy & histology/genetics/*isolation & purification ; Molecular Sequence Data ; Oenanthe/growth & development ; *Polymerase Chain Reaction ; Republic of Korea ; Sequence Analysis, DNA ; Snails/growth & development/*parasitology

PURPOSE: The biological function of long non-coding RNAs (lncRNAs) is only partially understood; therefore, in this study, we investigated the expression of the novel HOXA11 antisense (HOXA11as) lncRNA and its oncogenic role in serous ovarian cancer (SOC). MATERIALS AND METHODS: HOXA11as expression was examined in 129 SOC tissue samples by real time reverse transcription polymerase chain reaction. Clinicopathological factors and patient survival were compared between the high (n=27) and low HOXA11as expression group (n=102). To investigate the role of HOXA11as in cell proliferation, invasion, and migration, HOXA11as expression in ovarian cancer cells was knocked down using RNA interference. RESULTS: HOXA11as expression in cancer tissue was 77-fold higher than that of noncancerous tissue (p < 0.05). Higher HOXA11as expression was significantly correlated with histological grade (p=0.017) and preoperative cancer antigen 125 (p=0.048). HOXA11as overexpression in SOC cells led to increased cell proliferation, invasion, and migration. Moreover, HOXA11as was associated with the expression of genes involved in cell invasion, migration, and epithelial-mesenchymal transition (EMT), including vascular endothelial growth factor, matrix metalloproteinase 9 (MMP-9), B-catenin, E-cadherin, Snail, Twist, and vimentin. Multivariate analysis revealed that HOXA11as was a prognostic factor of progressive disease and mortality (hazard ratio [HR], 1.730; p=0.043 and HR, 2.170; p=0.033, respectively). Progression-free and overall survival were significantly shorter in patients with high HOXA11as expression. CONCLUSION: These findings highlight the clinical significance of HOXA11as to predicting the prognosis of SOC patients and suggest its potential in promoting tumor aggressiveness via regulation of vascular endothelial growth factor (VEGF), MMP-9, and EMT-related mechanisms.
Cadherins ; Cell Proliferation* ; Epithelial-Mesenchymal Transition ; Humans ; Matrix Metalloproteinase 9 ; Mortality ; Multivariate Analysis ; Ovarian Neoplasms* ; Polymerase Chain Reaction ; Prognosis* ; Reverse Transcription ; RNA Interference ; RNA, Long Noncoding* ; Snails ; Vascular Endothelial Growth Factor A ; Vimentin