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1.
Acta Trop ; 201: 105202, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31580848

RESUMO

Oncomelania hupensis plays a significant role in the transmission of schistosomiasis japonica, which remains a major public health concern in China. Understanding the biological characteristics of O. hupensis is a prerequisite for its control; however, there are currently no studies investigating the intestinal microbiota of the O. hupensis snail. This study aimed to profile the intestinal microbiome of O. hupensis across different ecological landscapes in mainland China. DNA was extracted from the intestines of the collected snails and the bacterial communities were detected using 454 pyrosequencing. A total of 3,799 operational taxonomic units (OTUs) were obtained, and Proteobacteria, Firmicutes, and Actinobacteria were identified as the dominant bacterial taxa at the phylum level. Bacillus and Lactococcus were the most common genera in samples obtained from the four ecological landscapes. Snail specimens were clustered into three clades according to microbial community diversity, and thirty-seven genera that contributed to differential microbiota distributions were identified. Co-occurrence network analysis indicated a symbiotic relationship for the intestinal microbiota of O. hupensis, and PICRUSt analysis predicted forty-one metabolic functions in all snail samples, including membrane transport, amino acid metabolism, carbohydrate metabolism, replication and repair, energy metabolism, as well as xenobiotics biodegradation and metabolism. These findings improve our understanding of bacterial ecology in the O. hupensis intestine; further studies will focus on the relationship between O. hupensis intestinal microbiota and the microbiota in their specific ecological environments.


Assuntos
Microbioma Gastrointestinal , Caramujos/microbiologia , Animais , Esquistossomose Japônica/transmissão
2.
Environ Monit Assess ; 192(1): 30, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31823074

RESUMO

The Gabcíkovo Water Project, a major construction of damming and canalizing on the upper part of the middle Danube, significantly changed hydrological regime of the Danube inland delta, destroyed or affected most of the 230 km2 of wetlands and directly disrupted the original and unique ecosystem along a 37 km long river stretch. The aim of this study was to describe the effect of the Gabcíkovo Waterworks on the taxonomical and functional structure of the molluscan assemblages in the Danube riparian floodplain forests. The results demonstrate that the Gabcíkovo Waterworks had a direct and long-lasting effect on the direction of the succession of terrestrial molluscan assemblages, especially in the area of the by-pass section. The changes in the soil moisture caused by the waterworks' operation led to significant changes in the species and functional composition of these assemblages. More specifically, however, the proportion of the generalists which prefer dry biotopes increased, while the number of moisture-demanding species decreased. Our results indicate that the current artificial flooding system cannot fully replace previous natural floods in the Danube inland delta, and it is also insufficient for restoration and preservation of the humidity conditions in the softwood floodplain forests which would be similar to the pre-operation period of the Gabcíkovo Waterworks.


Assuntos
Monitoramento Ambiental/métodos , Hidrologia/estatística & dados numéricos , Rios , Caramujos/fisiologia , Áreas Alagadas , Animais , Inundações/estatística & dados numéricos , Dinâmica Populacional , Solo/química
3.
Environ Monit Assess ; 191(11): 699, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31667650

RESUMO

Effects of industrial and municipal wastewaters on the freshwater snail, Lanistes carinatus, were evaluated. Concentrations of some chemicals in some effluents were greater than permissible limits promulgated internationally by various jurisdictions. Pesticides and polychlorinated biphenyls (PCBs) observed in tissues of snails collected during summer were greater than those measured in snails collected during winter. Catalase activities observed during autumn were greater than those observed during other seasons. Activities of catalase were greater at all sites near sources of contamination than in snails from the reference site (S6). Lactate dehydrogenase activity was also greater at all sites relative to the location designated as the reference (S6), at which activities did not exceed 8.10 U/L. Patterns of genomic DNA in snails, as determined by use of OPA-02 primer, were significantly different among sites. Location S1 (Belshay village) exhibited 11 bands, followed by S2 (El-Demer zone) and S5 (Rosetta branch) which exhibited 6 bands. In contrast, all sites exhibited greater numbers of bands when the OPA-08 primer was used. Thus, DNA fingerprinting, lactate dehydrogenase, and catalase offer useful biomarkers in ecotoxicology and risk assessment programs.


Assuntos
Monitoramento Ambiental , Compostos Orgânicos/toxicidade , Caramujos/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Catalase , Ecotoxicologia , Egito , Água Doce , Compostos Orgânicos/análise , Praguicidas , Bifenilos Policlorados , Estações do Ano , Poluentes Químicos da Água/análise
4.
Oecologia ; 191(4): 945-956, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31686229

RESUMO

Predicting the effects of predator diversity loss on food webs is challenging, because predators can both consume and induce behavioral responses in their prey (i.e., non-consumptive effects or NCEs). Studies manipulating predator diversity and investigating NCEs are rare, especially in marine systems. Recently, a severe outbreak of sea star wasting syndrome (SSWS) on the west coast of North America resulted in unprecedented declines of the sea star Pisaster ochraceus. We investigated the consequences of Pisaster loss on an abundant grazer, the black turban snail Tegula funebralis, through NCEs. We combined a laboratory experiment and field surveys to examine the importance of identity vs. diversity in a predator assemblage (Pisaster, crabs, and octopuses) on Tegula behavior, feeding, and growth. Laboratory and field results indicated that predator identity, not diversity, drives Tegula behavior and causes NCEs. Mesocosm treatments with Pisaster caused greater NCEs on Tegula than assemblages without Pisaster. Tegula's distribution in the field, which is driven primarily by anti-predator behavior, was strongly associated only with Pisaster abundance, and not with the abundance of crabs, octopuses, and other predatory sea stars (Leptasterias spp.). We conclude that Pisaster primarily drives Tegula vertical distribution and may be having strong NCEs on Tegula on northern California rocky shores. Furthermore, predator diversity in northern California does not provide functional redundancy, in terms of NCEs on Tegula, to buffer the system from Pisaster loss. Thus, predator-induced vertical distributions and grazing suppression may not be maintained in areas where Pisaster populations are reduced or slow to recover from SSWS.


Assuntos
Cadeia Alimentar , Comportamento Predatório , Animais , California , Caramujos , Estrelas-do-Mar
5.
Biochemistry (Mosc) ; 84(10): 1151-1165, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31694511

RESUMO

Uncouplers of oxidative phosphorylation in mitochondria, which have been essential in elucidating the basic principles of cell bioenergetics, have recently attracted a considerable interest as compounds with therapeutic, e.g., neuroprotective, properties. Here, we report the effect of mitofluorescein (mitoFluo), a new protonophoric uncoupler representing a conjugate of fluorescein with decyl(triphenyl)phosphonium, on the electrical activity of neurons from Lymnaea stagnalis. Incubation with mitoFluo in the dark led to a decrease in the absolute value of the resting membrane potential of the neurons and alterations in their spike activity, such as spike broadening, spike amplitude reduction, and increase in the spike frequency. Prolonged incubation at high (tens micromoles) mitoFluo concentrations resulted in complete suppression of neuronal electrical activity. The effect of mitoFluo on the neurons was qualitatively similar to that of the classical mitochondrial uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP) but manifested itself after much longer incubation and at higher concentrations. The distinctive feature of mitoFluo is its light-induced effect on the electrical activity of neurons. Changes in the parameters of the neuronal activity upon illumination in the presence of mitoFluo were similar to the light-induced effects of the well-known photosensitizer Rose Bengal, although less pronounced. It was suggested that the effects of mitoFluo on the electrical activity of neurons, both as a mitochondrial uncoupler and a photosensitizer, are mediated by the changes in the cytoplasmic calcium concentration.


Assuntos
Estimulação Elétrica , Fluoresceína/farmacologia , Corantes Fluorescentes/farmacologia , Neurônios/efeitos dos fármacos , Fotoquimioterapia , Prótons , Animais , Fluoresceína/química , Corantes Fluorescentes/química , Neurônios/metabolismo , Tanques , Caramujos
6.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(5): 459-462, 2019 Oct 12.
Artigo em Chinês | MEDLINE | ID: mdl-31713371

RESUMO

The construction of Yangtze River Economic Belt has been included in the national strategy of China, aiming to improve the economic level of the whole population, and to build a green ecological corridor with the joint development of economy, balance, ecology and equity. Yangtze River Economic Belt is the main area where schistosomiasis is endemic. During the economic construction, the prevention and control of schistosomiasis should be strictly carried out to facilitate the progress towards schistosomiasis elimination in China. In this paper, the endemic situation of schistosomiasis in Yangtze River Economic Belt areas and the possible impact on the schistosomiasis control were analyzed. In addition, a few suggestions were proposed for schistosomiasis control in Yangtze River Economic Belt areas.


Assuntos
Economia , Rios , Esquistossomose , Animais , China , Ecologia , Humanos , Esquistossomose/prevenção & controle , Caramujos
7.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(5): 463-467, 2019 Sep 27.
Artigo em Chinês | MEDLINE | ID: mdl-31713372

RESUMO

OBJECTIVE: To understand the situation of Schistosoma japonicum infections in wild animals in transmission-controlled schistosomiasis-endemic areas in Jiangxi Province, so as to provide scientific evidence for implementing precision control interventions and achieving the goal of transmission interruption and elimination of schistosomiasis. METHODS: Five endemic villages from Ruichang City and Pengze County that were heavily endemic for schistosomiasis in Jiangxi Province, were selected as the study villages. Wild animals like wild mice were captured, and the livers of wild animals were purchased from the snail habitats in the study villages for detection of S. japonicum infections. In the study villages, S. japonicum human infections were screened using indirect hemagglutination assay (IHA) followed by parasitological examinations with miracidial hatching test and Kato-Katz method, and the S. japonicum infection in livestock was tested using a miracidial hatching test with a plastic tube. In addition, snail survey was conducted in the study villages by means of systematic sampling combined with environmental sampling, and the S. japonicum infection in snails was detected using a loop-mediated isothermal amplification (LAMP) assay. RESULTS: A total of 240 liver specimens were sampled or purchased from 5 species of wild animals in the study villages, including wild mice, weasels, pigs, deer and rabbits. A total of 172 wild mice were captured, with a 2.91% rate of S. japonicum infection, and there was no S. japonicum infection detected in other wild animals. The prevalence of Capillaria hepatica infection was 12.21%, 1.96% and 12.50% in wild mice, deer and pigs, respectively. In addition, there was no S. japonicum infection found in either humans or livestock in the study villages, and the mean snail density varied from 0.13 to 0.80 snails/0.1 m2 in the study villages. LAMP assay detected S. japonicum infection in 2 tubes in a study village. CONCLUSIONS: The role of wild animals in schistosomiasis transmission and their potential risks can not be neglected in hilly schistosomiasis-endemic areas of Jiangsu Province after transmission control. Intensified surveillance and targeted control measures should be implemented to consolidate schistosomiasis control achievements.


Assuntos
Animais Selvagens , Schistosoma japonicum , Esquistossomose Japônica , Animais , Animais Selvagens/parasitologia , China/epidemiologia , Humanos , Fígado/parasitologia , Camundongos , Densidade Demográfica , Prevalência , Coelhos , Esquistossomose Japônica/epidemiologia , Esquistossomose Japônica/prevenção & controle , Caramujos/fisiologia , Inquéritos e Questionários , Suínos
8.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(5): 519-521, 2019 Oct 14.
Artigo em Chinês | MEDLINE | ID: mdl-31713383

RESUMO

OBJECTIVE: To understand the epidemic trend of schistosomiasis in China from 2010 to 2017 so as to provide the scientific evidence for schistosomiasis elimination. METHODS: The information of schistosomiasis control nationwide from 2010 to 2017 was collected, including the endemic of population, status of livestock control, and Oncomelania hupensis snail control. Microsoft Excel was applied for datum management and analysis. RESULTS: From 2010 to 2017, the epidemic of schistosomiasis in China dropped significantly. The decreasing amplitude of estimated number of patients nationwide was 88.46%. Seventy-one acute schistosomiasis patients were reported and 12.68% (9/71) of them were imported. The decreasing rate of cultivated cattle was 50.09%, and the accumulative number of schistosome-infected cattle was 17 239, and the average positive rate of stool examinations decreased from 1.04% to 0.000 22%. The area with snails nationwide was 373 596.18 to 363 068.95 hm2, and the new detected area with snails was 46.71 to 1 346.73 hm2. The area with schistosome-infected snails was 171.68 hm2 in 2012 and it was 9.25 hm2 in 2013. In 72 key monitoring points of 7 endemic provinces, there were 17 schistosome positive points of water body in 2010 and 6 points in 2016. There were some high risk-factors related to schistosomiasis transmission including schisto-some-infected cattle, dogs, and field rats, and the field stools, and the pasture in the area with snails in schistosomiasis monitoring points. CONCLUSIONS: The endemic status of schistosomiasis in China has dropped significantly, and the transmission level is very low. However, the infectious source and risk factors in the endemic environments have not be eliminated. Therefore, the infectious source control, health education, snail control, and transmission monitoring should be strengthened, so as to promote the progress of schistosomiasis elimination.


Assuntos
Doenças Endêmicas , Esquistossomose , Animais , Bovinos , China/epidemiologia , Cães , Doenças Endêmicas/estatística & dados numéricos , Fezes , Humanos , Ratos , Schistosoma , Esquistossomose/epidemiologia , Caramujos
9.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(5): 522-524, 2019 Aug 09.
Artigo em Chinês | MEDLINE | ID: mdl-31713384

RESUMO

OBJECTIVE: To understand the strategy of schistosomiasis elimination and its effects in Jinhu County, Jiangsu Province. METHODS: The data of schistosomiasis control in Jinhu County at different stages from 1970 to 2017 were collected and analyzed. RESULTS: From 1970 to 2017, there were three stages of schistosomiasis control, including transmission control, transmission interruption, and monitoring and elimination stages in Jinhu County. The main measures included Oncomelania hupensis snail control, infectious source control, and health education. A total of area of 290 691.78 hm2 was detected in Jinhu County, and the area with snails was 3 420.98 hm2. There were 8 729.37 hm2 area with snails was controlled. Since 2014, no O. hupensis snails were found. A total of 525 377 person-times were examined for schistosomiasis, with 2 815 schistosomiasis patients identified, and 2 844 person-times were treated by chemotherapy. In addition, 977 cases received the expand chemotherapy. Since 1990, no local schistosome-infected persons were found. In 2017, the awareness rate of schistosomiasis control knowledge and the correct rate of health behavior were increased by 54.59% and 14.23% respectively compared with those in 1992. CONCLUSIONS: The comprehensive schistosomiasis control measures implemented in Jinhu County at different periods have achieved remarkable outputs and accelerated the schistosomiasis elimination process. However, the precise control measures should be implemented in the future to consolidate the prevention and control achievements.


Assuntos
Erradicação de Doenças , Esquistossomose , Animais , Anti-Helmínticos/uso terapêutico , Conscientização , China , Erradicação de Doenças/métodos , Erradicação de Doenças/estatística & dados numéricos , Erradicação de Doenças/tendências , Comportamentos Relacionados com a Saúde , Humanos , Schistosoma/fisiologia , Esquistossomose/tratamento farmacológico , Esquistossomose/prevenção & controle , Caramujos/fisiologia
10.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(5): 535-537, 2019 Oct 16.
Artigo em Chinês | MEDLINE | ID: mdl-31713388

RESUMO

OBJECTIVE: To compare the effectiveness of snail control between immersion of molluscicides through tide diversion and mollusciciding by spraying in marshland areas. METHODS: Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion and spraying 26% suspension concentrate of metaldehyde and niclosamide alone were employed for snail control in two neighboring snail-breeding marshlands, and snails were surveyed before and after mollusciciding. The mortality of snails and the density of living snails were estimated. RESULTS: The density of living snails reduced by 72.19% and 100.00% 1 and 2 years after immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion, and 5.93% and 18.15% 1 and 2 years after spraying 26% suspension concentrate of metaldehyde and niclosamide alone. CONCLUSIONS: Immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion is significantly superior to spraying 26% suspension concentrate of metaldehyde and niclosamide along for snail control, and implementation of immersion of 26% suspension concentrate of metaldehyde and niclosamide through tide diversion for more than 2 successive years may achieve a higher snail control efficiency.


Assuntos
Moluscocidas , Niclosamida , Controle de Pragas , Caramujos , Animais , Imersão , Controle de Pragas/métodos , Inquéritos e Questionários , Suspensões , Ondas de Maré , Áreas Alagadas
11.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(5): 538-540, 2019 Jul 25.
Artigo em Chinês | MEDLINE | ID: mdl-31713389

RESUMO

OBJECTIVE: To understand the potential risk of schistosomiasis transmission in Xiuzhou District of Jiaxing City, so as to provide the scientific evidence for consolidating schistosomiasis control achievements. METHODS: Fixed and mobile surveillance sites were set up in Xiuzhou District of Jiaxing City from 2013 to 2015. Oncomelania hupensis snails was surveyed historical snail habitats, current snail habitats, and suspected snail habitats. The schistosome infections were identified using serological and parasitological testing among local residents and mobile populations. In addition, the survival and reproduction of snails imported into Xiuzhou District was observed, and the schistosome infection in wild reservoir hosts was detected. RESULTS: A total of 540.14 hm2 of settings were surveyed in Xiuzhou District, Jiaxing City from 2013 to 2015, and 1.65 hm2 of snail habitats were identified. The snail habitats were mainly located in dry lands, and no infected snails or importation of snails were found. During the period from 2013 to 2015, a total of 7 668 local residents and mobile populations were examined in Xiuzhou District, and no new local infections were detected; however, three imported schistosomiasis cases were identified. Field simulation experiment showed that the imported snails laid eggs and reproduced in Xiuzhou District, and no schistosome infections were found in wild animals. CONCLUSIONS: There are still residual Oncomelania snails and imported schistosomiasis patients in Xiuzhou District of Jiaxing City; therefore, the surveillance and management of local Oncomelania snails and imported schistosomiasis should be intensified to reduce the risk of schistosomiasis transmission.


Assuntos
Esquistossomose , Caramujos , Animais , China , Ecossistema , Humanos , Vigilância da População , Fatores de Risco , Schistosoma , Esquistossomose/transmissão , Caramujos/parasitologia , Caramujos/fisiologia , Inquéritos e Questionários
12.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(5): 541-542, 2019 Jul 31.
Artigo em Chinês | MEDLINE | ID: mdl-31713390

RESUMO

OBJECTIVE: To investigate the correlation between the source of Schistosoma japonicum infections and sociological factors among mobile populations in Haining City, so as to provide insights into the management of schistosomiasis among mobile populations in Haining City. METHODS: A total of 12 villages were randomly sampled from 8 townships and 4 subdistricts in Haining City. The mobile populations from schistosomiasis-endemic areas were detected for S. japonicum infections using serological tests. In addition, the awareness of schistosomiasis prevention and control knowledge was investigated using a questionnaire survey. RESULTS: A total of 1 019 mobile populations were investigated in 12 villages from Haining City, and 23 sero-positives were found, with a positive rate of 2.26%; however, no egg-positives were detected. Logistic regression analysis showed that the mobile populations with original occupations of aquaculture and husbandry were more likely to be sero-positive. The mobile populations had an overall low awareness rate of schistosomiasis prevention and control knowledge, and a higher rate was seen in sero-positive than in sero-negatives. CONCLUSIONS: The mobile populations with original occupations of aquaculture and husbandry were the key for the surveillance of source of S. japonicum infections. The health education should be intensified to improve the awareness of schistosomiasis prevention and control knowledge among mobile populations.


Assuntos
Esquistossomose Japônica , Esquistossomose , Animais , China/epidemiologia , Humanos , Dinâmica Populacional , Vigilância da População , Prevalência , Esquistossomose/epidemiologia , Caramujos , Fatores Sociológicos , Inquéritos e Questionários
13.
Zootaxa ; 4674(3): zootaxa.4674.3.1, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31716000

RESUMO

While Africa's lacustrine gastropod fauna, in particular of Lake Tanganyika, has received much attention, the continent's riverine malacofauna has long been neglected. Pseudocleopatra is a relatively poorly known paludomid gastropod genus with species found throughout the lower reaches of the West African Volta and Congo rivers. In the course of ongoing systematic revisions of African paludomids, we present here a morphometric analysis and revision of the recent species assigned to the genus, i.e., P. togoensis, P. voltana, P. dartevellei and P. bennikei, to improve taxonomic acuity for this group. We use available museum material for geometric morphometrics, multivariate ratio analysis and comparisons of radular and opercular characters. Our results demonstrate that the four recent species of Pseudocleopatra are clearly distinguishable on the basis of ratios of shell measurements as well as radular and opercular characters. Pseudocleopatra has generic-level synapomorphies including: concentric opercula with relatively large paucispiral nuclei, and rachidian radular teeth with usually 13-20 cusps. On the basis of this characterisation, the nominal species Cleopatra broecki is transferred to Pseudocleopatra. Additionally, the nominal taxon P. bennikei is synonymized with P. broecki n. comb. The phylogenetic relationships of Pseudocleopatra are currently unknown, but the observed tendency of some fossil taxa assigned to Pseudocleopatra towards thalassoidism, i.e., the resemblance to marine gastropods, has led to the hypothesis that some of the thalassoid endemics in Lake Tanganyika may have originated from or be related to Pseudocleopatra. Should this hypothesis be correct, which is in need of testing by molecular genetic methods when suitable samples become available, Pseudocleopatra may play a crucial role in understanding of the evolution of thalassoidism in African Paludomidae.


Assuntos
Fósseis , Caramujos , Animais , Congo , Filogenia , Tanzânia
14.
Zootaxa ; 4613(1): zootaxa.4613.1.4, 2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-31716426

RESUMO

Three species in the gastropod genus Calliostoma are confirmed as living in Deep-Water Coral (DWC) habitats in the NE Atlantic Ocean: Calliostoma bullatum (Philippi, 1844), C. maurolici (Seguenza, 1876) and C. leptophyma Dautzenberg Fischer, 1896. Up to now, C. bullatum was only known as fossil from Early to Mid-Pleistocene outcrops in DWC-related habitats in southern Italy; our study confirmed its living presence in DWC off Mauritania. A discussion is provided on the distribution of DWC-related calliostomatids in the NE Atlantic and the Mediterranean Sea from the Pleistocene to the present.


Assuntos
Antozoários , Gastrópodes , Animais , Oceano Atlântico , Ecossistema , Itália , Mauritânia , Mar Mediterrâneo , Caramujos , Água
15.
Zootaxa ; 4560(3): zootaxa.4560.3.8, 2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-31716572

RESUMO

The operculum morphology of neritid snails of genus Theodoxus Montfort, 1810 yields important species-specific taxonomic characters. This study is the first attempt to describe morphological differences in snails based on operculum shapes using a geometric morphometric approach. We examined the variability of opercular shapes between sexes and among populations and species based on 91 opercula of adult specimens belonging to six populations of three species of Theodoxus from the central Balkan and the southern border of the Pannonian plain. There are no sex-related differences in operculum shape and size in the studied species. The presence of shape variations influenced by size (allometry) was confirmed for T. danubialis (C. Pfeiffer, 1828) indicating that allometry could be a component of the morphological variation of this species. At the intraspecific level, phenotypic plasticity of operculum shape was found in T. danubialis and T. fluviatilis (Linnaeus, 1758). Of particular interest is the lack of morphological variability in the rare and endangered T. transversalis (C. Pfeiffer, 1828). At the species level a clear morphological distinction of T. fluviatilis from T. danubialis and T. transversalis was detected, confirming that the operculum with a rib could be used as a species-specific morphological character. The main morphological differences between species are an outwardly-stretched opercular/apophysal rib and a shortened tip of the opercular plate in T. fluviatilis, compared to the same structures in T. danubialis and T. transversalis.


Assuntos
Caramujos , Animais , Feminino , Masculino , Caracteres Sexuais
16.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(4): 368-373, 2019 Sep 25.
Artigo em Chinês | MEDLINE | ID: mdl-31612670

RESUMO

OBJECTIVE: To develop a method for designing schistosomiasis surveillance sites, so as to improve the efficiency and quality of schitsosomiasis surveillance. METHODS: By using the minimum spanning tree-based Spatial Kluster Analysis by Tree Edge Removal (SKATER) method, spatially constrained clustering was performed upon 31 historical schistosomiasis-endemic counties (districts) in Anhui Province. A surveillance site was selected from each cluster to evaluate the representativeness and surveillance efficiency of these cluster-based surveillance sites for the endemic situation of schistosomiassi in Anhui Province, and to compare the surveillance efficiency with local national schistosomiasis surveillance sites. RESULTS: There was no significant difference in the environmental factors between the cluster-based schistosomiasis surveillance sites and the whole region, showing a high homogeneity. If the same number of schistosomiasis surveillance sites was selected, there was no significant difference between the cluster-based surveillance sites and national schistosomiasis surveillance sites in the efficiency of the mean risk and long-term trend of schistosomiasis surveillance in Anhui Province; however, the cluster-based surveillance sites were superior to the national schistosomiasis surveillance sites for the prediction and estimation of the endemic situation of schistosomiasis in the unmonitored areas. CONCLUSIONS: The SKATER-based selection of schistosomiasis surveillance sites may better represent the endemic situation of schistosomiasis in Anhui Province, which may serve as an effective supplement for the conventional method of selecting schistosomiasis surveillance sites.


Assuntos
Métodos Epidemiológicos , Vigilância da População , Esquistossomose , Caramujos , Animais , China/epidemiologia , Análise por Conglomerados , Humanos , Vigilância da População/métodos , Schistosoma/fisiologia , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , Caramujos/parasitologia , Análise Espacial
17.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(4): 374-381, 2019 Sep 25.
Artigo em Chinês | MEDLINE | ID: mdl-31612671

RESUMO

OBJECTIVE: To investigate the spatial distribution of Oncomelania hupensis snail habitats at the administrative village scale in schistosomiasis-endemic areas of Hubei Province, so as to provide scientific bases for precise control of O. hupensis snails in the province. METHODS: Data regarding snail distribution at the village level in Hubei Province in 2017 were collected to create a spatial analysis database of snail distribution in Hubei Province. The spatial aggregations of O. hupensis distribution were analyzed using Moran's I index and Local Moran's I index. In addition, the distances from schistosomiasis-endemic villages to the Yangtze River were captured using the software ArcGIS 13.0, and their correlations with area of snail habitats were examined with the Spearman correlation method. RESULTS: O. hupensis snails were mainly distributed in 5 450 endemic villages from 63 counties of 13 cities in Hubei Province in 2017. The global spatial autocorrelation analysis showed spatial aggregations in the areas of historically accumulated snail habitats, current areas of snail habitats, areas of snail habitats outside the embankment and snail habitats inside the embankment (all Z Scores > 0, all P values < 0.05), and no spatial aggregation was seen in the areas of snail habitats in hilly areas (Z Score > 0, P > 0.05). There were four types of spatial distribution of historically accumulated areas of snail habitats, areas of current snail habitats, areas of snail habitats outside the embankment and snail habitats inside the embankment, including the high-high type (H-H type), high-low type (H-L type), low-high type (L-H type) and random distribution type, and a high percentage of the H-H type was found. There were 340, 125 and 110 endemic villages with the H-H type of areas of historically accumulated snail habitats, current areas of snail habitats and areas of snail habitats outside the embankment, and these villages were mainly concentrated in Wuhan and Jingzhou cities, with almost consistent spatial aggregation locations. There were 319 endemic villages with the H-H type of distribution of snail habitats inside the embankment, which were mainly distributed in Jingzhou, Xiaogan and Huangshi cities. In addition, the areas of historically accumulated snail habitats, current areas of snail habitats and areas of snail habitats outside the embankment negatively correlated with the distance from the endemic villages to the Yangtze River (r = -0.094, P < 0.01; r = -0.225, P < 0.01; r = -0.177, P < 0.01). CONCLUSIONS: The clustering areas of snail habitats along the Yangtze River Basin, notably the villages near the Yangtze River are key regions for snail monitoring and control in Hubei Province.


Assuntos
Distribuição Animal , Rios , Esquistossomose , Caramujos , Animais , China/epidemiologia , Ecossistema , Humanos , Rios/parasitologia , Schistosoma/fisiologia , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , Esquistossomose/transmissão , Caramujos/parasitologia , Caramujos/fisiologia , Análise Espacial
18.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(4): 410-413, 2019 Jul 29.
Artigo em Chinês | MEDLINE | ID: mdl-31612677

RESUMO

OBJECTIVE: To analyze the endemic sitaution of schistosomiasis based on geographic information system (GIS) in Wuhan City in 2017, so as to provide the reference for further schistosomiasis control activities. METHODS: According to the data of the annual report on the prevention and control of schistosomiasis in Wuhan City in 2017, the spatial database regarding the endemic situation of schistosomiasis was established and analyzed by ArcMap 10.2. RESULTS: The 593 schistosomiasis-endemic villages in Wuhan City were mainly located in the Yangtze River and its major tributaries. Kernel density analysis showed that the endemic villages of three regions with the highest density was located in the west of Caidian District (Zhuru Street), the east of Hannan District (Shamao Street) and the southwest corner of Xinzhou District (Yangluo Street). The sero-positive population was densely distributed in the West of Caidian District (Zhuru Street), which accounted for 34.23% of all seruo-positives in the city. There were 492 farming cattle fenced in Donggan Village in Hongbei Street of Caidian District. A higher density of the area with Oncomelania hupensis snails was located in the southwest region of Caidian District (Xiaosi Street), accounting for 31.22% of the total area with snails. In 2017, the re-emerging area with snails was 36.60 hm2. The high kernel density region with snails was located in Zhuru Street of Caidian District. The region with high density of living snails was located in the central region of Hannan District (Hongbei Production Brigade), the average density of living snails was 0.36 snails/0.1 m2. CONCLUSIONS: The endemic situation of schistosomiasis is at a low level in Wuhan City, and the spatial distribution is not uniform. In some local areas, the historical endemic situation of schistosomiasis is serious and the high risk factors are more concentrated. It is necessary to strengthen the surveillance of schistosomiasis.


Assuntos
Sistemas de Informação Geográfica , Esquistossomose , Animais , Anticorpos Anti-Helmínticos/sangue , China/epidemiologia , Doenças Endêmicas/estatística & dados numéricos , Humanos , Densidade Demográfica , Vigilância da População , Fatores de Risco , Esquistossomose/sangue , Esquistossomose/epidemiologia , Caramujos
19.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(4): 434-435, 2019 Sep 19.
Artigo em Chinês | MEDLINE | ID: mdl-31612683

RESUMO

OBJECTIVE: To analyze the surveillance data after schistosomiasis transmission interruption from 1985 to 2018, so as to provide scientific basis for the future prevention and control of schistosomiasis. METHODS: The data pertaining to snail survey, surveillance of schistosomiasis in humans and livestock, and health education were collected and analyzed in Songjiang District after schistosomiasis transmission interruption from 1985 to 2018. RESULTS: From 1985 to 2018, there were 8 townships, 68 villages and 1 462 settings with snails in Songjiang District, covering an area of 96.399 hm2. There were 4 townships and 59 villages with snails newly identified in previously schistosomiasis non-endemic areas, with emerging snail habitats of 60.161 hm2. A total of 26 148 snails were captured, and no infections were detected. The snail habitats were mainly distributed in the river course, ditches and farmlands, which accounted for 45.28%, 33.17% and 21.55% of total snail habitats, respectively. A total of 245 955 humans were subjected to the serological test, with a positive rate of 0.03%, and 37 humans were subjected to the parasitological test, with 3 positives detected. These three egg-positives were all imported chronic cases with schistosomiasis. A total of 9 109 livestock were detected using the serological test, and no infection was found. Most of the awareness rate of schistosomiasis control knowledge and the rate of correct behavior formation were over 80% in residents and students. CONCLUSIONS: The achievements of schistosomiasis control are consolidated in Songjiang District; however, there are still risk factors of schistosomiasis transmission, including residual snails, snail diffusion and importation of external source of infection. The future surveillance of schistosomiasis should focus on snails and sources of infection.


Assuntos
Esquistossomose , Caramujos , Animais , China/epidemiologia , Ecossistema , Humanos , Gado/parasitologia , Vigilância da População , Prevalência , Rios , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , Caramujos/parasitologia
20.
Results Probl Cell Differ ; 68: 155-182, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31598856

RESUMO

Sex determination and sexual development are highly diverse and controlled by mechanisms that are extremely labile. While dioecy (separate male and female functions) is the norm for most animals, hermaphroditism (both male and female functions within a single body) is phylogenetically widespread. Much of our current understanding of sexual development comes from a small number of model systems, limiting our ability to make broader conclusions about the evolution of sexual diversity. We present the calyptraeid gastropods as a model for the study of the evolution of sex determination in a sequentially hermaphroditic system. Calyptraeid gastropods, a group of sedentary, filter-feeding marine snails, are sequential hermaphrodites that change sex from male to female during their life span (protandry). This transition includes resorption of the penis and the elaboration of female genitalia, in addition to shifting from production of spermatocytes to oocytes. This transition is typically under environmental control and frequently mediated by social interactions. Males in contact with females delay sex change to transition at larger sizes, while isolated males transition more rapidly and at smaller sizes. This phenomenon has been known for over a century; however, the mechanisms that control the switch from male to female are poorly understood. We review here our current understanding of sexual development and sex determination in the calyptraeid gastropods and other molluscs, highlighting our current understanding of factors implicated in the timing of sex change and the potential mechanisms. We also consider the embryonic origins and earliest expression of the germ line and the effects of environmental contaminants on sexual development.


Assuntos
Organismos Hermafroditas/crescimento & desenvolvimento , Processos de Determinação Sexual , Caramujos/crescimento & desenvolvimento , Animais , Feminino , Masculino , Modelos Biológicos
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