Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 10.731
Filtrar
1.
Parasitol Int ; 86: 102469, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34534656

RESUMO

The metacercarial infections of door snails (Gastropoda: Clausiliidae) with unknown species of the genus Brachylaima (Trematoda: Brachylaimidae) have recently been reported in eastern Honshu and Kyushu, Japan. A large scale snail survey was carried out to clarify their taxonomic status. From the period of 2015 to 2020, a total of 1239 land snails (768 door snails and 471 others) were collected from 32 localities in Honshu, Shikoku, and Kyushu. The resulting trematode isolates were identified as Brachylaima sp. by mitochondrial DNA barcoding. The sporocysts were found only a few from Megalophaedusa sublunellata (Clausiliidae), Tauphaedusa subaculus (Clausiliidae), and Aegista trochula (Camaenidae), while the metacercariae were frequently detected from 14 species of Clausiliidae and 2 species of other families. Although Brachylaima sp. showed a broad range of intermediate hosts, door snails seem to be very important to drive the life cycle. The gravid adults of Brachylaima sp. was experimentally raised from metacercariae using immunosuppressed mice. Morphological, phylogenetical, and ecological considerations prompted us to propose Brachylaima phaedusae n. sp. for this unknown species. The definitive hosts of the new species are completely unknown. The wide geographic distribution and high genetic diversity of the new species suggest a possibility that the definitive host is ground-foraging birds, which prefer door snails.


Assuntos
Caramujos/parasitologia , Trematódeos/classificação , Animais , Código de Barras de DNA Taxonômico , DNA Mitocondrial/análise , Feminino , Japão , Camundongos Endogâmicos ICR , Trematódeos/anatomia & histologia , Trematódeos/genética
2.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 33(5): 445-451, 2021 Oct 27.
Artigo em Chinês | MEDLINE | ID: mdl-34791840

RESUMO

OBJECTIVE: To establish a deep learning-based visual model for intelligent recognition of Oncomelania hupensis, the intermediate host of Schistosoma japonicum, and evaluate the effects of different training strategies for O. hupensis image recognition. METHODS: A total of 2 614 datasets of O. hupensis snails and 4 similar snails were generated through field sampling and internet capture, and were divided into training sets and test sets. An intelligent recognition model was created based on deep learning, and was trained and tested. The precision, sensitivity, specificity, accuracy, F1 score and Youden index were calculated. In addition, the receiver operating characteristic (ROC) curve of the model for snail recognition was plotted to evaluate the effects of "new learning", "transfer learning" and "transfer learning + data enhancement" training strategies on the accuracy of the model for snail recognition. RESULTS: Under the "transfer learning + data enhancement" strategy, the precision, sensitivity, specificity, accuracy, Youden index and F1 score of the model were 90.10%, 91.00%, 97.50%, 96.20%, 88.50% and 90.51% for snail recognition, which were all higher than those under both "new learning" and "transfer learning" strategies. There were significant differences in the sensitivity, specificity and accuracy of the model for snail recognition under "new learning", "transfer learning" and "transfer learning + data enhancement" training strategies (all P values < 0.001). In addition, the area under the ROC curve of the model was highest (0.94) under the "transfer learning + dataenhancement" training strategy. CONCLUSIONS: This is the first visual model for intelligent recognition of O. hupensis based on deep learning, which shows a high accuracy for snail image recognition. The "transfer learning + data enhancement" training strategy is helpful to improve the accuracy of the model for snail recognition.


Assuntos
Aprendizado Profundo , Schistosoma japonicum , Animais , China , Caramujos
3.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 33(5): 457-463, 2021 Oct 27.
Artigo em Chinês | MEDLINE | ID: mdl-34791842

RESUMO

OBJECTIVE: To evaluate the impact of water pollutants, water levels and meteorological factors on the Oncomelania hupensis density in Eastern Dongting Lake regions, so as to provide insights into schistosomiasis control. METHODS: O. hupensis snails were surveyed using a systematic sampling method in snail-infested marshlands in Eastern Dongting Lake regions from 2007 to 2014, and data pertaining to water pollutants, water levels and meteorological factors were collected. The duration of submergence and the date of the start of submergence were calculated. The snail density and its influencing factors were descriptively analyzed, and a linear mixed model was generated to examine the impacts of variables on the snail density. In addition, smooth curves were fitted to investigate the relationship between snail density and variables. RESULTS: The snail density appeared a fluctuation in Eastern Dongting Lake regions during the period from 2007 to 2014, with the highest density on October, 2010 (52.79 snails/0.1 m2) and the lowest density on January 2009 (2.15 snails/0.1 m2). Linear mixed-model analysis showed that permanganate index, total phosphorus and the date of the start of submergence affected the snail density (t = 6.386, -2.920 and -3.892, all P values < 0.01). Smooth curve analysis revealed that the associations of the snail density with the permanganate index and total phosphorus appeared an approximately quadratic curve. After the end of April, the earlier date of the start of submergence resulted in a higher snail density. CONCLUSIONS: Permenganate index, total phosphorus and the date of the start of submergence affect the O. hupensis snail density in Eastern Dongting Lake regions.


Assuntos
Lagos , Esquistossomose , Animais , China , Caramujos , Água
4.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 33(5): 523-526, 2021 Jun 21.
Artigo em Chinês | MEDLINE | ID: mdl-34791853

RESUMO

Chengdu-Chongqing economic circle is centered on Chengdu City and Chongqing Municipality, with aims to build the "fourth growth pole" of China's economy. During this circle, elimination of schistosomiasis had been achieved in 82.5% of the endemic counties (districts) of Sichuan Province, and schistosomiasis is not historically endemic in Chongqing Municipality; however, there is still a risk of schistosmiasis transmission in Sichuan Province and Chongqing Municipality because the natural and social factors affecting schistosomiasis transmission have not been completely eliminated in these areas. Based on the endemic situation of schistosomiasis in Sichuan Province and Chongqing Municipality, we analyzed the opportunities and challenges of schistosomiasis control during the construction of Chengdu-Chongqing economic circle, and proposed the corresponding suggestions, so as to provide insights into the sustainable development of schistosomiasis control in the context of the Chengdu-Chongqing economic circle construction.


Assuntos
Esquistossomose , Caramujos , Animais , China/epidemiologia , Cidades , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , Fatores Sociais , Desenvolvimento Sustentável
5.
J Helminthol ; 95: e66, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34784987

RESUMO

Host-parasite coevolution may result in life-history changes in hosts that can limit the detrimental effects of parasitism. Fecundity compensation is one such life-history response, occurring when hosts increase their current reproductive output to make up for expected losses in future reproduction due to parasitic infection. However, the potential trade-offs between this increase in quantity and the quality of offspring have been relatively unexplored. This study uses the trematode, Schistosoma mansoni, and its snail intermediate host, Biomphalaria glabrata, to better understand how this host life-history response, fecundity compensation, impacts host reproduction. Measures of host reproductive output as well as offspring hatching success and survival were collected to assess the reproductive consequences of infection. Infected snails exhibited fecundity compensation by increasing the number of eggs laid and the overall probability of laying eggs compared to uninfected snails. Parental infection status did not play a significant role in hatching or offspring survival to maturity. Offspring from a later reproductive bout demonstrated a higher hatching success rate. Overall, the lack of an apparent trade-off between quantity and quality of offspring suggests that infected parental snails invest more resources towards reproduction not only to increase reproductive output, but also to maintain the fitness of their offspring, possibly at the expense of their own longevity.


Assuntos
Biomphalaria , Animais , Fertilidade , Interações Hospedeiro-Parasita , Reprodução , Schistosoma mansoni , Caramujos
6.
An Acad Bras Cienc ; 93(suppl 4): e20210078, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34706007

RESUMO

The objective of this study was to evaluate the possible relaxing effect of essential oils (EOs) (Aloysia triphylla and Lippia alba) and phytochemicals (citral and linalool) in the gastropod Pomacea canaliculata. Animals were exposed to compounds at the concentrations range of 25-750 µL L-1. Magnesium chloride (MgCl2, 10-50 g L-1) and control group (ethanol 6.75 mL L-1, highest concentration used for treatment dilution) were also tested. The EOs, citral and MgCl2 had no relaxing effect at the concentrations range tested, and citral caused aversive behavior (closure of the operculum) from 90 µL L-1. Exposure to linalool at 25, 50, 100, 200 and 400 µL L-1 relaxed 28, 76, 88, 96 and 100% of the animals, respectively. The concentrations of 25, 50 and 400 µL L-1 differed statistically from each other, while 100 and 200 µL L-1 were equal to 50 and 400 µL L-1. All animals recovered up to 40 min, except at of 400 µL L-1. Linalool is effective for relaxing P. canaliculata and can be useful in management techniques that require relaxation. However, further studies are needed to certify whether linalool is appropriate for maintaining animal welfare in invasive procedures that require total insensitivity.


Assuntos
Monoterpenos Acíclicos/farmacologia , Lippia , Caramujos/efeitos dos fármacos , Verbenaceae , Animais
7.
Environ Monit Assess ; 193(10): 690, 2021 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-34601695

RESUMO

The rapidly changing marine environmental chemistry associated with growing industrialisation, urban population expansion, and the unabated rise in atmospheric CO2 necessitates monitoring. Traditional approaches using metres, dataloggers, and buoys to monitor marine acidification have limited application in coastal oceans and intertidal zones subjected to direct wave action. The present study trialled a system to biomonitor coastal acidification (carbonate ion and pH) based on the dissolution of living gastropod shells. We extended on an approach that ranked shell erosion (SER) in Nerita chamaeleon (Nc) in environments where such erosion was found to correlate with exposure to acidified water. We assessed the spatial scale at which the Nc-SER marker could detect change in acidification along rocky shores, and whether snail body size affected this marker. We found that proportional and unique Nc-SERs not only varied between acidified and non-acidified reference shores at a coarse spatial scale (10 km), but also in predictable ways at fine scales (metres), vertically and horizontally within a shore. Differences between acidified and reference shores in the relationship for snail size and Nc-SER were accentuated by less weathered shells at reference localities, highlighting the value of including small, juvenile snails in monitoring protocols. Gastropod shells are shown to be useful for assessing point sources of acidification and the spatial area of affected coastal zones. This cost-effective and easy-to-use approach (potentially even by citizen-scientists) offers an early warning system of acidification of rocky shore ecosystems, where the deployment of instruments is precluded.


Assuntos
Ecossistema , Água do Mar , Animais , Monitoramento Ambiental , Concentração de Íons de Hidrogênio , Caramujos
8.
Environ Sci Technol ; 55(21): 14699-14709, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34677949

RESUMO

Herbicides are well known for unintended effects on freshwater periphyton communities. Large knowledge gaps, however, exist regarding indirect herbicide impacts on primary consumers through changes in the quality of periphyton as a food source (i.e., diet-related effects). To address this gap, the grazer Physella acuta (Gastropoda) was fed for 21 days with periphyton that grew for 15 days in the presence or absence of the herbicide diuron (8 µg/L) to quantify changes in the feeding rate, growth rate, and energy storage (neutral lipid fatty acids; NLFAs) of P. acuta. Periphyton biomass, cell viability, community structure, and FAs served as proxies for food quality that support a mechanistic interpretation of the grazers' responses. Diuron changed the algae periphyton community and fatty acid profiles, indicating alterations in the food quality, which could explain differences in the snails' feeding rate compared to the control. While the snails' growth rate was, despite an effect size of 55%, not statistically significantly changed, NLFA profiles of P. acuta were altered. These results indicate that herbicides can change the food quality of periphyton by shifts in the algae composition, which may affect the physiology of grazers.


Assuntos
Herbicidas , Perifíton , Animais , Biomassa , Diurona , Herbicidas/toxicidade , Caramujos
9.
Physiol Biochem Zool ; 94(6): 366-379, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34477491

RESUMO

AbstractTheoretical models about the relationship between food restriction and individual differences in risk-taking behavior (i.e., boldness) have led to conflicting predictions: some models predict that food restriction increases boldness, while other models predict that food restriction decreases boldness. This discrepancy may be partially attributable to an underappreciation for animals' complex physiological responses to food restriction. To understand the proximate mechanisms mediating state-dependent boldness, we used freshwater snails (Helisoma trivolvis) to examine the relationships among food availability, body condition, boldness (latency to reemerge from shell and exploration), and mRNA expression of three genes (adenosine monophosphate-activated protein kinase [AMPK], molluscan insulin-like peptide [MIP], and serotonin receptor [5-HT]) involved in maintaining energy homeostasis during periods of moderate food restriction. Latency to reemerge and exploratory behavior decreased over time, but fed snails were bolder than fasted snails, suggesting that food restriction reduces bold behavior. Although food restriction decreased body condition, there was not a relationship between body condition and latency to reemerge from shell. However, expression of MIP was positively correlated with latency to reemerge from shell. Furthermore, AMPK was positively correlated with MIP and negatively correlated with body condition and 5-HT. Therefore, individual differences in physiological responses to food restriction, not overall body condition per se, appear to be more closely associated with state-dependent bold behavior. Finally, snails that experienced a novel assay environment returned to their initial "shy" behavior, suggesting that habituation to the assay environment may contribute to snails expressing bolder behavior over time.


Assuntos
Comportamento Animal , Caramujos , Animais , Alimentos , Caramujos/genética
10.
Front Public Health ; 9: 680986, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34568251

RESUMO

The introduction of non-native species and deforestation are both important drivers of environmental change that can also facilitate the geographic spread of zoonotic pathogens and increase disease risk in humans. With ongoing trends in globalization and land-use conversions, introduced species and deforestation are ever more likely to pose threats to human health. Here, we used rat lungworm disease, an emerging zoonotic disease caused by Angiostrongylus cantonensis and maintained by invasive rats and snails, to explore how these two forms of environmental change can impact zoonotic disease risk. We used logistic regressions to examine the role of global trade in the introduction of A. cantonensis at a country level and used model estimates to predict the probability of introduction as a function of trade. We then used hurdle-based regression models to examine the association between deforestation and rat lungworm disease in two regions where A. cantonensis is already established: Hawaii and Thailand. At the global scale, we found the trade of horticultural products to be an important driver in the spread of A. cantonensis and that the majority of countries at high risk of future A. cantonensis introduction are islands. At country scales, we found deforestation to increase the per-capita risk of A. cantonensis exposure in Hawaii and Thailand. Our study provides a preliminary view of the associations between species introductions, deforestation, and risk of A. cantonensis exposure in people. Better understanding how these two widespread and overlapping forms of environmental change affect human health can inform international biosecurity protocols, invasive species management, and land-use policies.


Assuntos
Angiostrongylus cantonensis , Animais , Conservação dos Recursos Naturais , Hawaii/epidemiologia , Ratos , Caramujos , Zoonoses/epidemiologia
11.
Microbiome ; 9(1): 182, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34479645

RESUMO

BACKGROUND: Deep-sea animals in hydrothermal vents often form endosymbioses with chemosynthetic bacteria. Endosymbionts serve essential biochemical and ecological functions, but the prokaryotic viruses (phages) that determine their fate are unknown. RESULTS: We conducted metagenomic analysis of a deep-sea vent snail. We assembled four genome bins for Caudovirales phages that had developed dual endosymbiosis with sulphur-oxidising bacteria (SOB) and methane-oxidising bacteria (MOB). Clustered regularly interspaced short palindromic repeat (CRISPR) spacer mapping, genome comparison, and transcriptomic profiling revealed that phages Bin1, Bin2, and Bin4 infected SOB and MOB. The observation of prophages in the snail endosymbionts and expression of the phage integrase gene suggested the presence of lysogenic infection, and the expression of phage structural protein and lysozyme genes indicated active lytic infection. Furthermore, SOB and MOB appear to employ adaptive CRISPR-Cas systems to target phage DNA. Additional expressed defence systems, such as innate restriction-modification systems and dormancy-inducing toxin-antitoxin systems, may co-function and form multiple lines for anti-viral defence. To counter host defence, phages Bin1, Bin2, and Bin3 appear to have evolved anti-restriction mechanisms and expressed methyltransferase genes that potentially counterbalance host restriction activity. In addition, the high-level expression of the auxiliary metabolic genes narGH, which encode nitrate reductase subunits, may promote ATP production, thereby benefiting phage DNA packaging for replication. CONCLUSIONS: This study provides new insights into phage-bacteria interplay in intracellular environments of a deep-sea vent snail. Video Abstract.


Assuntos
Bacteriófagos , Animais , Bactérias/genética , Bacteriófagos/genética , Genômica , Proteômica , Caramujos , Transcriptoma/genética
12.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 33(4): 420-423, 2021 Aug 24.
Artigo em Chinês | MEDLINE | ID: mdl-34505453

RESUMO

OBJECTIVE: To analyze the surveillance data of schistosomiasis in Xiaogan City, Hubei Province from 2016 to 2020, so as to provide the scientific evidence for understanding the epidemiological changes of schistosomiasis and evaluating the schistosomiasis control strategy. METHODS: A total of 16 surveillance sites were selected in the schistosomiasis endemic foci of Xiaogan City from 2016 to 2020, where Schistosoma japonicum infections in humans, livestock and Oncomelania snails and the schistosomiasis transmission risk were monitored. The schistosomiasis surveillance results were descriptively analyzed. RESULTS: During the period from 2016 to 2020, there was no schistosomiasis emergency epidemic in Xiaogan City. A total of 660 sero-positive individuals were identified in Xiaogan City during the 5-year period, and the seroprevalence of S. japonicum infections reduced from 2.08% in 2016 to 0.97% in 2020. Higher seroprevalence of S. japonicum infections was detected in men than in women, and in individuals at ages of over 60 years than in those at other age groups; however, no egg-positives were detected in humans or livestock. The mean density of living snails was 0.05 to 0.06 snails/0.1 m2 during the 5-year period, and the occurrence of frames with snails increased from 2.99% in 2016 to 3.92% in 2020; however, no S. japonicum infection was found in snails. CONCLUSIONS: The endemic situation of schistosomiasis remarkably decreases in Xiaogan City during the period from 2016 through 2020. Further improvements of the sensitive and effective schistosomiasis surveillance system are required with an emphasis on the monitoring of the schistosomiasis transmission risk and management of floating populations.


Assuntos
Esquistossomose Japônica , Esquistossomose , Animais , China/epidemiologia , Doenças Endêmicas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , Esquistossomose Japônica/epidemiologia , Esquistossomose Japônica/prevenção & controle , Estudos Soroepidemiológicos , Caramujos
13.
Braz J Biol ; 83: e248420, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34495163

RESUMO

Very little is known about the malacofauna in district Swat of Khyber Pakhtunkhwa province, situated in the Northern part of Pakistan. The Swat valley possesses a variety of suitable environmental conditions, providing different types of habitats for both flora and fauna. Taken into consideration these points, the present study was conducted to explore the terrestrial snails diversity in agricultural and non-agricultural fields in the lower Swat valley. A total of 417 shells were collected from three sites: Kokarai, Kanju Township, and Deolai. Based on conchological features, three families: Bradybaenidae, Hygromiidae, and Zonitidae were identified using different terrestrial snail keys. In Kokarai and Deolai, shells of members of all the above-mentioned families were found from agricultural fields. In Kanju Township, shells of members of the family Bradybaenidae and Zonitidae were found. From these findings, it was concluded that district Swat possesses a significant malacofauna which was unexplored before and aided more to the existing literature on malacofauna. It also supports the idea that the agroecosystem is rich in species diversity. Further in-depth and extensive study is recommended to be carried out for a detailed taxonomy of the described terrestrial gastropod families.


Assuntos
Agricultura , Ecossistema , Animais , Humanos , Paquistão , Caramujos
14.
Dis Aquat Organ ; 146: 23-28, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34498607

RESUMO

The cockle Cerastoderma edule, a socioeconomically important bivalve of the northeast Atlantic, is host to several trematodes, including Himasthla elongata. In the life cycle of this trematode, cercariae (free-living stages) emerge from the first intermediate host, a snail, to infect cockles as second intermediate hosts. During their lifespan (less than 2 d), cercariae must ensure successful host-to-host transmission via the surrounding water and therefore are exposed to and impacted by different environmental conditions, including abiotic factors. Given that the light:dark cycle is one of the major drivers of behaviour in aquatic habitats, we aimed to determine the influence of light on cercariae and host behaviour based on 3 hypotheses. First, by having a benthic second intermediate host, these cercariae will display a photonegative orientation; second, and conversely, host behaviour will not be influenced by light; and third, cercariae infection success will be light-dependent. Results showed that cercariae display a photopositive orientation (first hypothesis rejected), displaying movements towards light. Host activity (evaluated by oxygen consumption) was similar among conditions, i.e. dark vs. light (second hypothesis accepted), but hosts acquired more parasites when experimentally infected in the dark (third hypothesis accepted). This light-dependent infection of the host is explained by a change of cercarial behaviour when exposed to light, decreasing their infection success. This study highlights that trematode responses to external conditions may be linked to successful life cycle completion rather than being altered by the host habitat. Light influence on cercarial behaviour resulted in increased infection success that may affect trematode population dynamics and their distributional range.


Assuntos
Bivalves , Cardiidae , Trematódeos , Infecções por Trematódeos , Animais , Cercárias , Interações Hospedeiro-Parasita , Caramujos , Infecções por Trematódeos/veterinária
15.
Environ Sci Pollut Res Int ; 28(43): 61841-61847, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34550517

RESUMO

In this study, CaO prepared by calcination treatment from abandoned Achatina fulica shell was used as a raw material, and the floral CaO/ZnO photocatalytic composite material was prepared through co-precipitation method. SEM study showed ZnO with spindle-like petals in the range of 500-1000 nm grown on the surface of CaO carrier. The mapping image shows that the base component of the floral structure is mainly CaO, which is because CaO is not only in the reaction as a carrier, but also creates an alkaline environment in the methanol system, which is advantageous for co-precipitation. UV-vis spectroscopy shows that the visible light absorption of composites has red shifts; besides, PL, EIS, and photocurrent test showed that the composites have stronger electronic hole separation capabilities. The visible light degradation test of rhodamine B showed that CaO/ZnO photocatalytic composite could degrade 90% of the pollutants in 25 min, superior to CaO and ZnO, exhibiting recyclability properties, which is a potential candidate with cost-effective and sustainable photocatalysts.


Assuntos
Óxido de Zinco , Animais , Catálise , Luz , Caramujos
16.
Bull Environ Contam Toxicol ; 107(5): 833-837, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34379140

RESUMO

The faucet snail, Bithynia tentaculata, is an invasive snail that facilitates outbreaks of waterfowl disease in the Upper Mississippi River of the United States. In response, there is interest in identifying strategies that mitigate its population and spread. In this study we assessed the effects of a copper (Cu) molluscicide, EarthTec® QZ, at three concentrations (0, 0.1 and 0.6 mg/L Cu) on adult B. tentaculata and a coexisting native species, Physa gyrina. We found that in the 0.6 mg/L Cu treatment, ~ 68% of B. tentaculata snails remained alive after a 4-day exposure whereas all P. gyrina snails died. In contrast, a majority of both snail species remained alive and active after 4 days in the control and 0.1 mg/L Cu treatments. Although B. tentaculata demonstrated higher survivorship, it bioaccumulated more Cu than P. gyrina. Additionally, examination of B. tentaculata individuals revealed that females tended to exhibit higher mortality than males.


Assuntos
Moluscocidas , Praguicidas , Animais , Cobre/toxicidade , Feminino , Humanos , Moluscocidas/toxicidade , Praguicidas/toxicidade , Rios , Caramujos
17.
Physiol Biochem Zool ; 94(6): 353-365, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34431748

RESUMO

AbstractThermal stress is a potentially important selective agent in intertidal marine habitats, but the role that thermal tolerance might play in local adaptation across shore height has been underexplored. Northwest Spain is home to two morphologically distinct ecotypes of the periwinkle Littorina saxatilis, separated by shore height and subject to substantial differences in thermal stress exposure. However, despite other biotic and abiotic drivers of ecotype segregation being well studied, their thermal tolerance has not been previously characterized. We investigated thermal tolerance across multiple life history stages by employing the thermal death time (TDT) approach to determine (i) whether the two ecotypes differ in thermal tolerance and (ii) how any differences vary with life history stage. Adults of the two ecotypes differed in their thermal tolerance in line with their shore position: the upper-shore ecotype, which experiences more extreme temperatures, exhibited greater endurance of thermal stress compared with the lower-shore ecotype. This difference was most pronounced at the highest temperatures tested. The proximate physiological basis for these differences is unknown but likely due to a multifarious interaction of traits affecting different parts of the TDT curve. Differences in tolerance between ecotypes were less pronounced in early life history stages but increased with ontogeny, suggesting partial divergence of this trait during development. Thermal tolerance could potentially play an important role in maintaining population divergence and genetic segregation between the two ecotypes, since the increased thermal sensitivity of the lower-shore ecotype may limit its dispersal onto the upper shore and so restrict gene flow.


Assuntos
Ecótipo , Caramujos , Animais , Ecossistema , Fluxo Gênico , Fenótipo
18.
Molecules ; 26(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34443296

RESUMO

In recent decades liposomes have been used in different field thanks to their ability to act as a vehicle for a wide range of biomolecules, their great versatility and their easy production. The aim of this study was to evaluate liposomes as a vehicle for the actives present in the HelixComplex (HC) snail mucus for topical delivery. Liposomes composed of a mixture of phosphatidylcholine, cholesterol and octadecylamine were prepared with and without HC (empty liposomes) and their biological efficacy was tested by evaluating cell viability and migration. HC-loaded liposomes (LHC) were stable throughout 60 days of observation, and showed interesting effects on wound healing reconstitution. In particular, we observed that 25 µg/mL LHC were already able to induce a higher cell monolayer reconstitution in comparison to the untreated samples and HC treated samples after only 4 h (28% versus 10% and 7%, p = 0.03 and p= 0.003, respectively). The effect was more evident at 24 h in comparison with the untreated control (54% versus 21.2% and 41.6%, p = 0.006 and p = NS, respectively). These results represent a preliminary, but promising, novelty in the delivery strategy of the actives present in the HelixComplex mucus.


Assuntos
Muco/química , Caramujos/química , Animais , Morte Celular , Linhagem Celular , Fibroblastos/citologia , Técnica de Fratura por Congelamento , Humanos , Lipídeos/análise , Lipossomos/ultraestrutura , Espectrofotometria Infravermelho , Cicatrização/efeitos dos fármacos
19.
Microb Pathog ; 159: 105120, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34358648

RESUMO

Diabetes and obesity have become the most popular metabolic diseases in the world. A large number of previous studies have shown that glucose and lipid metabolism disorder is an important risk factor and a main cause of diabetes and obesity. Schistosoma is a parasite transmitted by freshwater snails. It can induce a series of inflammatory and immune reactions after infecting the human body, causing schistosomiasis. However, in recent years, studies have found that Schistosoma infection or Schistosoma related products can improve or prevent some immune and inflammatory diseases, such as severe asthma, inflammatory bowel disease, diabetes and so on. Further experiments have also revealed that Schistosoma can promote the secretion of anti-inflammatory factors and regulate the glucose and lipid metabolism in the host body by polarizing immune cells such as T cells, B cells and dendritic cells (DCs). In this review, we summarize studies that investigated Schistosoma and Schistosoma-derived products and their relationship with glycolipid metabolism and related diseases, highlighting potential protective mechanisms.


Assuntos
Schistosoma , Esquistossomose , Animais , Glicolipídeos , Humanos , Metabolismo dos Lipídeos , Caramujos
20.
Braz J Biol ; 83: e246934, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34431912

RESUMO

Physids belong to Class Gastropoda; Phylum Mollusca have important position in food web and act as bio indicators, pests and intermediate host. Being resistant these are called cockroaches of malacology. Physid snails were collected from different water bodies of Faisalabad (Punjab) and were identified up to species using morphological markers. The morphometry of the specimens was carried out with the help of a digital Vernier caliper in millimeters (mm) using linear measurement of shell characters. Linear regression analysis of the AL/SW ratio vs AL and SL/SW ratio vs AL indicated that allometric growth exists only in Physa acuta when compared with P.gyrina and P. fontinalis. This study will lead to assess the status of the Physid species in Central Punjab. The Principal component analysis shows that the Component 1 (Shell Length) and component 2 (Shell Width) are the most prolific components and nearly 80 percent of the identification. The distance between P. acuta and P. fontinalis is 5.4699, P. acuta and P. gyrina is 7.6411, P. fontinalis and P. gyrina is 16.6080 showing that P. acuta resembles with P. fontinalis, and both these specimens donot resemble with P. gyrina. P.acuta is an invasive species and shows bioactivity making it a potent candidate for bioactive substances.


Assuntos
Espécies Introduzidas , Caramujos , Animais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA