Objective:To explore the effect of AIBL on Oncomelania hupensis,the intermediate snail host of Schistosoma japonicum.Methods:The enzyme histochemical profiles of cholineslerase, cytochrome oxidase,lactate dehydrogenas...Objective:To explore the effect of AIBL on Oncomelania hupensis,the intermediate snail host of Schistosoma japonicum.Methods:The enzyme histochemical profiles of cholineslerase, cytochrome oxidase,lactate dehydrogenase,nitric oxide synthase,and succinate dehydrogenase in the soft tissues of Oncomelania hupensis,the intermediate host snail of Schistosoma japonicum, were analyzed before and after treatment with the active ingredient of Buddleia lindleyana(AIBL), a potent and safe plant molluscicide.Results:Treatment with AIBL induced a notable decrease in the activities of the five enzymes(P【0.01).Conclusions:The results indicate that AIBL impairs the activities of the enzymes,thereby influencing the transfer of neurotransmitter and energy supply in Oncomelania hupensis and ultimately harming their various physiological functions, which are considered to cause death of the species.展开更多
Schistosomiasis is a parasitic disease mostly found in areas along the Changjiang River of China. The disease is spread solely through an intermediary named oncomelania, so its spread of schistosomiasis can be control...Schistosomiasis is a parasitic disease mostly found in areas along the Changjiang River of China. The disease is spread solely through an intermediary named oncomelania, so its spread of schistosomiasis can be controlled by properly designing water intakes which prevent oncomelania from entering farming land or residential areas. This paper reports a successful design process and a new oncomelania free intake device. The design of the new intake is based on a sound research program in which extensive experimental studies were carried out to gain knowledge of oncomelania eco hydraulic behavior and detailed flow field information through CFD simulation.展开更多
Climate change has been known to cause variations in the geographically suitable areas for the schistosome-transmitting Oncomelania hupensis(O.hupensis).The spread of snails not only depends on the degree of warming b...Climate change has been known to cause variations in the geographically suitable areas for the schistosome-transmitting Oncomelania hupensis(O.hupensis).The spread of snails not only depends on the degree of warming but also on the socioeconomic development of the next few decades.Shared socioeconomic pathways(SSPs)published by CMIP6 consider carbon emission pathways as well as influences of distinct types of social development and land use on the regional climate,providing the possibility to accurately evaluate the impact of socioeconomic development and climate variation on the spread of O.hupensis.This study employed SSP126,SSP245,SSP370,and SSP585 and the correlative approach to explore the impacts of climate change and socioeconomic development on the potential diffusion areas for O.hupensis in China.The results exhibited strong evidence that O.hupensis will spread in the north of the middle and lower reaches of the Yangtze River and disappear from a small part of its current southern habitat,whereas in Sichuan and Yunnan,O.hupensis may spread slightly to the southeast.The projection also demonstrated that fossil fuel-driven development(SSP585)will be more conducive to the spread of O.hupensis breeding sites in the 2030s,whereas the continuous increase in snail breeding habitats under the regional rivalry path(SSP370)may lead to great challenges in snail control in the long term(2020-2080).展开更多
Background:Schistosomiasis japonica is a chronic parasitic disease that seriously harms people's health.Oncomelonia hupensis is the only intermediate host of Schistosoma japonicum.Jhe micro-environmental factors s...Background:Schistosomiasis japonica is a chronic parasitic disease that seriously harms people's health.Oncomelonia hupensis is the only intermediate host of Schistosoma japonicum.Jhe micro-environmental factors surrounding the snail have a great impact on the survival,growth and reproduction of 0.hupensis,but there are few relevant systematic analyses until the present.This scoping review aims to identify and summarize the micro-environmental factors that greatly affect 0.hupensis,and to find gaps in research thus to provide directions for future in-depth studies.展开更多
Background:Control of snail intermediate hosts has been proved to be a fast and efficient approach for interrupting the transmission of schistosomiasis.Some plant extracts have shown obvious molluscicidal activity,and...Background:Control of snail intermediate hosts has been proved to be a fast and efficient approach for interrupting the transmission of schistosomiasis.Some plant extracts have shown obvious molluscicidal activity,and a new compound Luo-Wei,also named tea-seed distilled saponin(TDS),was developed based on the saponins extracted from Camellia oleifera seeds.We aimed to test the molluscicidal activity of 4%TDS against the intermediate host snails in China and Egypt,and evaluate its environmental safety to non-target organisms.Methods:In the laboratory,Oncomelania hupensis,Biomphalaria alexandrina and Bulinus truncatus were exposed to 4%TDS,and the median lethal concentration(LC5o)was estimated at 24,48 and 72 h.In the field,snail mortalities were assessed 1,2,3 and 7 d post-immersion with 2.5 g/m34%TDS and 1,3,7 and 15 d post-spraying with 5 g/m24%TDS.in addition,the acute toxicity of 4%TDS to Japanese quail(Coturnixjaponica),zebrafish(Brachydanio rerio)and freshwater shrimp(Macrobrachium nipponense)was assessed by estimations of LC5o or median lethal dose(LD5o).Results:In the laboratory,the LC5o values of 4%TDS for O.hupensis were 0.701,0.371 and 0.33 mg/L at 24,48 and 72 h,respectively,and 4%TDS showed a 0.33 mg/L 24 h LC5o against B.alexandrina,and a 1.396 mg/L 24 h LCs0 against B.truncatus.Across all study regions,the pooled mortalities of O.hupensis were 72,86,94 and 98%at 1,2,3 and 7 d,following field immersion of 4%TDS at a dose of 2.5 g/m3,and were 69,77,85 and 88%at 1,3,7 and 15 d,following field spraying at 5 g/m2,respectively.4%TDS had moderate toxicity to Japanese quail(7 d LD5o>60 mg/kg)and to shrimp(96 h LCs0=6.28 mg/L;95%CI:3.53-11.2 mg/L),whereas its toxicity to zebrafish was high(96 h LCso--0.15 mg/L;95%CI:0.14-0.17 mg/L).Conclusions:4%TDS is active against O.hupensis,B.alexandrina and B.truncatus under laboratory and field conditions,and it may be a candidate molluscicide of plant origin.展开更多
Background Oncomelania hupensis is the only intermediate host of Schistosoma japonicum and plays a decisive role in its transmission.The variation of water level greatly affects the reproduction and growth of snails.T...Background Oncomelania hupensis is the only intermediate host of Schistosoma japonicum and plays a decisive role in its transmission.The variation of water level greatly affects the reproduction and growth of snails.Therefore,in this paper,we analyze the variations of water level in the Poyang Lake region from 1993 to 2016 combined with satellite imagery to elucidate the evolution of the snail breeding environment.Methods By employing remote sensing data from 1993 to 2016(April–June and September–November),the vegetation area of Poyang Lake and the vegetation area at different elevations were extracted and calculated.Moreover,the average daily water level data from the four hydrological stations(Hukou station,Xingzi station,Tangyin station and Kangshan station)which represent the typical state of Poyang Lake were collected from 1993 to 2016.The variance of the monthly mean water level,inundation time and the average area were analyzed by variance to find a significance level ofα=0.05.Results According to hydrological data before and after 2003,the average water level after 2003 is significantly lower than that before 2003 in Poyang Lake.After 2003,the time of inundateing the snail breeding period was later in April to June than that before 2003,while the time of wate-falling stage in September to November moved forward after 2003 than before 2003.Of them,the lowest water level affecting the breeding and growing period of O.hupensis in the northern part of Poyang Lake decreased from 11 m to 9 m.After 2003,the expansion of meadow area in the north part of Poyang Lake was mainly concentrated in the elevation of 9–11 m,and the newly increased infested-meadow in the lake area was mainly concentrated in the north part of Poyang Lake.Conclusions By comparing the change of water level characteristics in different parts of the Poyang Lake area as well as changes in meadow area before and after 2003,it is found that the water level changes mainly affect the snail breeding area in the northern part of Poyang Lake.The results are helpful for improving scientific measures for snail control in Jiangxi Province.This approach could also be applicible to Dongting Lake area and other lake areas affected by water level changes and can bring significant guidance for snail control in lake areas.展开更多
To study the toxicity of extracts of Ginkgo biloba sarcotesta to Oncomelania hupensis,snails were exposed to 40% and 80% of 24 h LC 50 of the extract of Ginkgo bilba for 24 h,choline esterase(ChE),alanine aminotransfe...To study the toxicity of extracts of Ginkgo biloba sarcotesta to Oncomelania hupensis,snails were exposed to 40% and 80% of 24 h LC 50 of the extract of Ginkgo bilba for 24 h,choline esterase(ChE),alanine aminotransferase(ALT),alkaline phosphatase(ALP),lactate dehydrogenase(LDH),succino dehydrogenase(SDH),malic dehydrogenase(MDH)activities in cephalopodium and liver were determined by enzyme kinetic assay.Arecoline and niclosamide were used as reference molluscicides.The results showed that sarcotesta of Ginkgo biloba could inhibit ChE,ALT,ALP and MDH activities both in cephalopodium and liver;arecoline could inhibit ChE,ALP,SDH and MDH activities in cephalopodium and ChE,ALT,ALP,SDH and MDH activities in liver.Niclosamide had inhibitory effects upon ChE,ALT,ALP,SDH and MDH activities in cephalopodium,and ChE,ALT,ALP and SDH activities in liver.All three molluscicides did not inhibite LDH activity in cephalopodium and liver.These results indicate that lethal effects of extracts of sarcotesta of Ginkgo biloba are mediated via inhibition of MDH activitiy,and interference with the NADH respiratory chains.Inhibition of vital enzymic mechanisms causes snails to death.展开更多
文摘Objective:To explore the effect of AIBL on Oncomelania hupensis,the intermediate snail host of Schistosoma japonicum.Methods:The enzyme histochemical profiles of cholineslerase, cytochrome oxidase,lactate dehydrogenase,nitric oxide synthase,and succinate dehydrogenase in the soft tissues of Oncomelania hupensis,the intermediate host snail of Schistosoma japonicum, were analyzed before and after treatment with the active ingredient of Buddleia lindleyana(AIBL), a potent and safe plant molluscicide.Results:Treatment with AIBL induced a notable decrease in the activities of the five enzymes(P【0.01).Conclusions:The results indicate that AIBL impairs the activities of the enzymes,thereby influencing the transfer of neurotransmitter and energy supply in Oncomelania hupensis and ultimately harming their various physiological functions, which are considered to cause death of the species.
基金Acknowledgments The authors would like to thank the National Natural Science Foundation of China （grant No. 30471506, 30570322, 39670654, 30671818） and the Science and Technology Foundation of Forest （No. 2006BAD03AI 5） for providing funds to the research.
文摘Schistosomiasis is a parasitic disease mostly found in areas along the Changjiang River of China. The disease is spread solely through an intermediary named oncomelania, so its spread of schistosomiasis can be controlled by properly designing water intakes which prevent oncomelania from entering farming land or residential areas. This paper reports a successful design process and a new oncomelania free intake device. The design of the new intake is based on a sound research program in which extensive experimental studies were carried out to gain knowledge of oncomelania eco hydraulic behavior and detailed flow field information through CFD simulation.
基金supported by the Fifth Round of the Three-Year Public Health Action Plan of Shanghai(GWV-10.1-XK13)the National Natural Science Foundation of China(No.32161143036)the National Special Science and Technology Project for Major Infection Diseases of China(2016ZX10004222-004).
文摘Climate change has been known to cause variations in the geographically suitable areas for the schistosome-transmitting Oncomelania hupensis(O.hupensis).The spread of snails not only depends on the degree of warming but also on the socioeconomic development of the next few decades.Shared socioeconomic pathways(SSPs)published by CMIP6 consider carbon emission pathways as well as influences of distinct types of social development and land use on the regional climate,providing the possibility to accurately evaluate the impact of socioeconomic development and climate variation on the spread of O.hupensis.This study employed SSP126,SSP245,SSP370,and SSP585 and the correlative approach to explore the impacts of climate change and socioeconomic development on the potential diffusion areas for O.hupensis in China.The results exhibited strong evidence that O.hupensis will spread in the north of the middle and lower reaches of the Yangtze River and disappear from a small part of its current southern habitat,whereas in Sichuan and Yunnan,O.hupensis may spread slightly to the southeast.The projection also demonstrated that fossil fuel-driven development(SSP585)will be more conducive to the spread of O.hupensis breeding sites in the 2030s,whereas the continuous increase in snail breeding habitats under the regional rivalry path(SSP370)may lead to great challenges in snail control in the long term(2020-2080).
文摘Background:Schistosomiasis japonica is a chronic parasitic disease that seriously harms people's health.Oncomelonia hupensis is the only intermediate host of Schistosoma japonicum.Jhe micro-environmental factors surrounding the snail have a great impact on the survival,growth and reproduction of 0.hupensis,but there are few relevant systematic analyses until the present.This scoping review aims to identify and summarize the micro-environmental factors that greatly affect 0.hupensis,and to find gaps in research thus to provide directions for future in-depth studies.
基金the National Science and Technology Pillar Program(grant No.2009BAI78B07 and 2009BAI78B04)National S&T Major Program(grant No.2012ZX10004-220)+3 种基金Shanghai Science and Technology Committee(grant No.11XD1405400)Jjiangsu Provincial Health and Family Planning Commission(grant No.QNRC2016621 and H2018097)Wuxi Municipal Bureau of Science and Technology(grant No.CSE31N1730)Bill&Melinda Gates Foundation.
文摘Background:Control of snail intermediate hosts has been proved to be a fast and efficient approach for interrupting the transmission of schistosomiasis.Some plant extracts have shown obvious molluscicidal activity,and a new compound Luo-Wei,also named tea-seed distilled saponin(TDS),was developed based on the saponins extracted from Camellia oleifera seeds.We aimed to test the molluscicidal activity of 4%TDS against the intermediate host snails in China and Egypt,and evaluate its environmental safety to non-target organisms.Methods:In the laboratory,Oncomelania hupensis,Biomphalaria alexandrina and Bulinus truncatus were exposed to 4%TDS,and the median lethal concentration(LC5o)was estimated at 24,48 and 72 h.In the field,snail mortalities were assessed 1,2,3 and 7 d post-immersion with 2.5 g/m34%TDS and 1,3,7 and 15 d post-spraying with 5 g/m24%TDS.in addition,the acute toxicity of 4%TDS to Japanese quail(Coturnixjaponica),zebrafish(Brachydanio rerio)and freshwater shrimp(Macrobrachium nipponense)was assessed by estimations of LC5o or median lethal dose(LD5o).Results:In the laboratory,the LC5o values of 4%TDS for O.hupensis were 0.701,0.371 and 0.33 mg/L at 24,48 and 72 h,respectively,and 4%TDS showed a 0.33 mg/L 24 h LC5o against B.alexandrina,and a 1.396 mg/L 24 h LCs0 against B.truncatus.Across all study regions,the pooled mortalities of O.hupensis were 72,86,94 and 98%at 1,2,3 and 7 d,following field immersion of 4%TDS at a dose of 2.5 g/m3,and were 69,77,85 and 88%at 1,3,7 and 15 d,following field spraying at 5 g/m2,respectively.4%TDS had moderate toxicity to Japanese quail(7 d LD5o>60 mg/kg)and to shrimp(96 h LCs0=6.28 mg/L;95%CI:3.53-11.2 mg/L),whereas its toxicity to zebrafish was high(96 h LCso--0.15 mg/L;95%CI:0.14-0.17 mg/L).Conclusions:4%TDS is active against O.hupensis,B.alexandrina and B.truncatus under laboratory and field conditions,and it may be a candidate molluscicide of plant origin.
文摘Background Oncomelania hupensis is the only intermediate host of Schistosoma japonicum and plays a decisive role in its transmission.The variation of water level greatly affects the reproduction and growth of snails.Therefore,in this paper,we analyze the variations of water level in the Poyang Lake region from 1993 to 2016 combined with satellite imagery to elucidate the evolution of the snail breeding environment.Methods By employing remote sensing data from 1993 to 2016(April–June and September–November),the vegetation area of Poyang Lake and the vegetation area at different elevations were extracted and calculated.Moreover,the average daily water level data from the four hydrological stations(Hukou station,Xingzi station,Tangyin station and Kangshan station)which represent the typical state of Poyang Lake were collected from 1993 to 2016.The variance of the monthly mean water level,inundation time and the average area were analyzed by variance to find a significance level ofα=0.05.Results According to hydrological data before and after 2003,the average water level after 2003 is significantly lower than that before 2003 in Poyang Lake.After 2003,the time of inundateing the snail breeding period was later in April to June than that before 2003,while the time of wate-falling stage in September to November moved forward after 2003 than before 2003.Of them,the lowest water level affecting the breeding and growing period of O.hupensis in the northern part of Poyang Lake decreased from 11 m to 9 m.After 2003,the expansion of meadow area in the north part of Poyang Lake was mainly concentrated in the elevation of 9–11 m,and the newly increased infested-meadow in the lake area was mainly concentrated in the north part of Poyang Lake.Conclusions By comparing the change of water level characteristics in different parts of the Poyang Lake area as well as changes in meadow area before and after 2003,it is found that the water level changes mainly affect the snail breeding area in the northern part of Poyang Lake.The results are helpful for improving scientific measures for snail control in Jiangxi Province.This approach could also be applicible to Dongting Lake area and other lake areas affected by water level changes and can bring significant guidance for snail control in lake areas.
文摘To study the toxicity of extracts of Ginkgo biloba sarcotesta to Oncomelania hupensis,snails were exposed to 40% and 80% of 24 h LC 50 of the extract of Ginkgo bilba for 24 h,choline esterase(ChE),alanine aminotransferase(ALT),alkaline phosphatase(ALP),lactate dehydrogenase(LDH),succino dehydrogenase(SDH),malic dehydrogenase(MDH)activities in cephalopodium and liver were determined by enzyme kinetic assay.Arecoline and niclosamide were used as reference molluscicides.The results showed that sarcotesta of Ginkgo biloba could inhibit ChE,ALT,ALP and MDH activities both in cephalopodium and liver;arecoline could inhibit ChE,ALP,SDH and MDH activities in cephalopodium and ChE,ALT,ALP,SDH and MDH activities in liver.Niclosamide had inhibitory effects upon ChE,ALT,ALP,SDH and MDH activities in cephalopodium,and ChE,ALT,ALP and SDH activities in liver.All three molluscicides did not inhibite LDH activity in cephalopodium and liver.These results indicate that lethal effects of extracts of sarcotesta of Ginkgo biloba are mediated via inhibition of MDH activitiy,and interference with the NADH respiratory chains.Inhibition of vital enzymic mechanisms causes snails to death.
