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1.
J Sep Sci ; 43(1): 258-270, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31654552

RESUMO

Microfluidic chip electrophoresis has been widely employed for separation of various biochemical species owing to its advantages of low sample consumption, low cost, fast analysis, high throughput, and integration capability. In this article, we reviewed the development of four different modes of microfluidics-based electrophoresis technologies including capillary electrophoresis, gel electrophoresis, dielectrophoresis, and field (electric) flow fractionation. Coupling detection schemes on microfluidic electrophoresis platform were also reviewed such as optical, electrochemical, and mass spectrometry method. We further discussed the innovative applications of microfluidic electrophoresis for biomacromolecules (nucleic acids and proteins), biochemical small molecules (amino acids, metabolites, ions, etc.), and bioparticles (cells and pathogens) analysis. The future direction of microfluidic chip electrophoresis was predicted.

2.
Sci Rep ; 9(1): 18684, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31822723

RESUMO

The soil-water interfaces (SWI) in soil pores are hotspots for organic matter (OM) transformation. However, due to the heterogeneous and opaque nature of soil microenvironment, direct and continuous tracing of interfacial reactions, such as OM transformations and formation of organo-mineral associations, are rare. To investigate these processes, a new soil microarray technology (SoilChips) was developed and used. Homogeneous 800-µm-diameter SoilChips were constructed by depositing a dispersed Oxisol A horizon suspension on a patterned glass. Dissolved organic matter from the original soil was added on the SoilChips to mimic SWI processes. The effects of ammonium fertilization (90 mg N kg-1 soil) on chemical composition of SWIs were evaluated via X-ray photoelectron spectroscopy. Over 21 days, ammonium addition increased OM coatings at SWIs and modified the OM chemical structure with more alcoholic- and carboxylic-C compared to the unfertilized control. Molecular modeling of OM composition at SWIs showed that N fertilization mainly facilitated the microbial production of glucans. We demonstrated that N availability modifies the specific OM molecular processing and its immobilization on SWIs, thereby providing a direct insight into biogeochemical transformation of OM at micro-scale.

3.
Mar Pollut Bull ; 145: 118-125, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590767

RESUMO

The effects of short-term (7 days) experimental ocean acidification (-0.4 pH units) and warming (+5 °C) on anti-predator defenses of two sympatric Mytilus species from China, M. coruscus and M. edulis, in the presence and absence of predator cues were investigated. Results suggested species-specific independent negative effects of acidification and warming on the number and weight of byssal threads, the force of thread attachment, and total thread plaque area. Similar negative effects were observed for clustering behaviour, with acidification and warming independently increasing the number of solitary individuals and decreasing the percentage of mussels in clusters. Acidification effects on byssus were strongly exacerbated when predators were present. Ultimately, this study suggests that short-term exposure to experimental warming and acidification can negatively impact anti-predator defense strategies in mussels with potential ramifications for predator-prey interactions and ecological functioning in systems where mussel beds play a key ecological role.


Assuntos
Mytilus/fisiologia , Água do Mar/química , Temperatura , Animais , Comportamento Animal , China , Concentração de Íons de Hidrogênio , Mytilus/classificação , Especificidade da Espécie
4.
Quant Imaging Med Surg ; 9(5): 823-831, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31281778

RESUMO

Background: Digital pathology is experiencing an exponential period of growth catalyzed by advancements in imaging hardware and progresses in machine learning. The use of whole slide imaging (WSI) for digital pathology has recently been cleared for primary diagnosis in the US. The demand for using frozen section procedure for rapid identification of cancerous tissue during surgery is another driving force for the development of WSI. A conventional WSI system scans the tissue slide to different positions and acquires the digital images. In a typical implementation, a focus map is created prior to the scanning process, leading to significant overhead time and a necessity for high positional accuracy of the mechanical system. The resulting cost of WSI system is often prohibitive for frozen section procedure during surgery. Methods: We report a novel WSI scheme based on a programmable LED array for sample illumination. In between two regular brightfield image acquisitions, we acquire one additional image by turning on a red and a green LED for color multiplexed illumination. We then identify the translational shift of the red- and green-channel images by maximizing the image mutual information or cross-correlation. The resulting translational shift is used for dynamic focus correction in the scanning process. Since we track the differential focus during adjacent acquisitions, there is no positional repeatability requirement in our scheme. Results: We demonstrate a prototype WSI platform with a mean focusing error of ~0.3 microns. Different from previous implementations, this prototype platform requires no focus map surveying, no secondary camera or additional optics, and allows for continuous sample motion in the focus tracking process. Conclusions: A programmable LED array can be used for color-multiplexed single-shot autofocusing in WSI. The reported scheme may enable the development of cost-effective WSI platforms without positional repeatability requirement. It may also provide a turnkey solution for other high-content microscopy applications.

5.
Aquat Toxicol ; 212: 241-246, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31150951

RESUMO

Nowadays, eutrophication is a very popular environmental problem in numerous waters around the world. The main reason of eutrophication is the enrichment of the nutrient, which results in the excessive growth of phytoplankton and some of them are toxic and harmful. Fortunately, some studies have shown that some bivalves can filter the overgrown phytoplankton in water, which may alleviate water eutrophication. However, the physiological effects of toxic cyanobacteria on filter feeding animal have not been clarified very well. In this experiment, digestive enzyme activities in Hyriopsis cumingii exposed to different concentrations of the toxic Microcystis aeruginosa (0, 5 * 105 and 5 *106 cell ml-1) at two dissolved oxygen (DO) levels (6 and 2 mg l-1) for 14 days were investigated. Toxic M. aeruginosa significantly affected all digestive enzyme activities throughout the experiment. At high toxic M. aeruginosa concentration, the activities of cellulase, amylase and lipase in digestive gland and stomach were significantly increased (P<0.05). However, hypoxia reduced the activities of cellulase, amylase and lipase in digestive gland and stomach. Conflicting effects were observed between toxic M. aeruginosa and DO in most digestive enzyme activities during the exposure period. Therefore, it is not conducive for the digestion and absorption of M. aeruginosa in H. cumingii under hypoxic conditions. H. cumingii is tolerant to toxic M. aeruginosa and may remove toxic cyanobacteria from waters under normal DO conditions.


Assuntos
Bivalves/efeitos dos fármacos , Microcistinas/toxicidade , Microcystis/química , Anaerobiose/fisiologia , Animais , Bivalves/enzimologia , Bivalves/fisiologia , Ativação Enzimática/efeitos dos fármacos , Enzimas/metabolismo , Eutrofização , Oxigênio/metabolismo , Poluentes Químicos da Água/toxicidade
6.
Aquat Toxicol ; 212: 28-36, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31048143

RESUMO

Titanium dioxide nanoparticles (TiO2 NPs) are widely used in various products and inevitably released with different sizes and forms into aquatic environment. The purpose of this study was to assess the differential immune toxicity of TiO2 NPs with size difference on mussel hemocytes using flow cytometry (FCM) assays. Hemocyte parameters, including total hemocyte count (THC), hemocyte mortality (HM), phagocytosis activity (PA), lysosomal content (LC), esterase activity (EA), mitochondrial number (MN), mitochondrial membrane potential (MMP) and reactive oxygen species content (ROS) were evaluated in the mussels Mytilus coruscus exposed to two types of TiO2 NPs (25nm & 100nm: 0.1, 1, 10 mg/L, respectively). In general, size- and concentration-dependent toxicity was pronounced with 25nm-NP and highest concentration (10mg/L) being the most toxic. Alhough a slight recovery from the TiO2 exposure was observed, significant carry-over effects were still detected. These results highlight the importance of differential size effects of metal oxide NPs on toxicity mechanisms in aquatic animals.


Assuntos
Hemócitos/efeitos dos fármacos , Mytilus/efeitos dos fármacos , Nanopartículas/toxicidade , Tamanho da Partícula , Titânio/toxicidade , Análise de Variância , Animais , Contagem de Células , Esterases/metabolismo , Hemócitos/citologia , Lisossomos/efeitos dos fármacos , Nanopartículas/ultraestrutura , Análise de Componente Principal , Poluentes Químicos da Água/toxicidade
7.
Mar Environ Res ; 145: 73-80, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30833041

RESUMO

Transgenerational effects of multiple stressors on marine organisms are emerging environmental themes. We thus experimentally tested for transgenerational effects of seawater acidification and hypoxia on the early development traits of the mussel Mytilus edulis. Fertilization rate, embryo deformity rate, and larval shell length were negatively impacted by acidification, while hypoxia had little effect except for increasing deformity rates under control pH conditions. Offspring from low pH/O2 parents were less negatively affected by low pH/O2 conditions than offspring from control parents; however, low pH/O2 conditions still negatively affected developmental traits in offspring from acclimated parents compared to control seawater conditions. Our results demonstrate that experimental seawater acidification and hypoxia can adversely affect early developmental traits of M. edulis and that parental exposure can only partially alleviate these impacts. If experimental observations hold true in nature, it is unlikely that parental exposure will confer larval tolerance to ocean acidification for M. edulis.


Assuntos
Mytilus edulis , Animais , Dióxido de Carbono , Homeostase , Concentração de Íons de Hidrogênio , Hipóxia , Mytilus edulis/crescimento & desenvolvimento , Água do Mar
8.
Aquat Toxicol ; 203: 61-68, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30096478

RESUMO

With the development of industry and agriculture, the metal pollutants (e.g., Cu) are inevitably released into the aquatic environment. In addition, ocean acidification (OA) as a major environmental stress is affecting marine organisms. In this study, we investigated the hemocyte responses of the estuarine oyster Crassostrea rivularis exposed to six combinations of two pH levels (8.1 and 7.7) and three Cu concentrations (0, 10 and 50 µg/l) using flow cytometry in vitro and in vivo. In both experiments, Cu and low pH jointly affected the hemocyte parameters of oyster. High Cu exposure resulted in decreased total hemocyte count (THC), esterase activity (EA) and lysosomal content (LC) and increased hemocyte mortality (HM), phagocytosis activity (PA) and reactive oxygen species (ROS) production, especially under low pH conditions. The immune suppression of metal-exposure was more significant than low pH exposure with a 28-d experimental period in oysters. A slight recovery of the immune parameters was observed in THC, HM, PA, ROS and LC. During the depuration period, the modulatory effects of pH were still obvious. In addition, carry-over effects of high Cu and low pH were still observed. Overall, our results showed that copper and low pH weaken immune functions of hemocyte in oysters, with synergistic effects. This work provides new evidence of sublethal negative effects of metals on marine animals under global change scenarios, and copper likely leads to reduced fitness of oysters under low pH conditions.


Assuntos
Cobre/toxicidade , Crassostrea/metabolismo , Estuários , Hemócitos/metabolismo , Análise de Variância , Animais , Contagem de Células , Crassostrea/efeitos dos fármacos , Hemócitos/citologia , Hemócitos/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Análise de Componente Principal , Água do Mar , Poluentes Químicos da Água/toxicidade
9.
Front Physiol ; 9: 757, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29971017

RESUMO

In order to investigate the ecotoxicological effects of nano-ZnO particles and seawater acidification on marine bivalves, the thick shell mussels, Mytilus coruscus were subjected to joint treatments with different nano-ZnO concentrations (0 [control], 2.5 [medium] and 10 mg L-1 [high]) under two pH levels (7.7 [low]and 8.1 [control]) for 14 days. The results showed that respiration rate (RR), absorption efficiency (AE), clearance rate (CR), O:N ratio and scope for growth (SFG) were significantly reduced with nano-ZnO concentration increase, but ammonium excretion rate (ER) was increased. Low pH significantly reduced CR, RR, SFG, and O:N ratio of the mussels especially under high nano-ZnO conditions, and significantly increased ER. Principal component analysis (PCA) showed consistent relationships among most tested parameters, especially among SFG, RR, O:N ratio and CR under the normal pH and 0 nano-ZnO conditions. Therefore, seawater acidification and nano-ZnO interactively impact the ecophysiological responses of mussels and cause more severe effects when they appear concurrently.

10.
Sci Total Environ ; 640-641: 726-735, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-29879661

RESUMO

Increased production of engineered nanoparticles has raised extensive concern about the potential toxic effects on marine organisms living in estuarine and coastal environments. Meanwhile, salinity is one of the key environmental factors that may influence the physiological activities in flatfish species inhabiting in those waters due to fluctuations caused by freshwater input or rainfall. In this study, we investigated the oxidative stress and histopathological alteration of the juvenile Paralichthys olivaceus exposed to nano-TiO2 (1 and 10 mg L-1) under salinities of 10 and 30 psu for 4 days. In the gills, Na+-K+-ATPase activity significantly deceased after 4 days 10 psu exposure without nano-TiO2 compared with 1 day of acclimating the salinity from the normal salinity (30 psu) to 10 psu. Under this coastal salinity, low concentration (1 mg L-1) of nano-TiO2 exerted significant impacts. In the liver, the activities of superoxide dismutase, catalase, the levels of lipid peroxide and malondialdehyde increased with nano-TiO2 exposed under 30 psu. Such increase indicated an oxidative stress response. The result of the integrated biomarker responses showed that P. olivaceus can be adversely affected by high salinity and high concentration of nano-TiO2 for a short-term (4 days) exposure. The histological analysis revealed the accompanying severe damages for the gill filaments. Principal component analysis further showed that the oxidative stress was associated with the nano-TiO2 effect at normal salinity. These findings indicated that nano-TiO2 and normal salinity exert synergistic effects on juvenile P. olivaceus, and low salinity plays a protective role in its physiological state upon short-term exposure to nano-TiO2. The mechanism of salinity mediating the toxic effects of NPs on estuarine fish should be further considered.


Assuntos
Linguado/fisiologia , Nanopartículas/toxicidade , Salinidade , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Brânquias , Olea , Testes de Toxicidade
11.
Mar Environ Res ; 137: 49-59, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29503109

RESUMO

Biochemical responses of the mussel Mytilus coruscus exposed to different concentrations of titanium dioxide nanoparticles (nano-TiO2) (0, 2.5, 10 mg L-1) and two pH levels (pH 8.1 and pH 7.3) for 14 days. Mussel responses were also investigated after a 7 days recovery period (pH 8.1 and no nanoparticle). Exposure to nano-TiO2 led changes in antioxidant indexes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH)), biotransformation enzyme activity (GST) and malondialdehyde level (MDA) in gills and digestive glands. An increase in MDA level and a decrease in SOD and GSH activities were observed in gill of mussels exposed to 10 mg L-1 nano-TiO2. This effect was more severe in mussels kept at pH 7.3 as compared to pH 8.1. A different response was observed in the digestive gland as SOD, CAT and GSH levels increased in mussels exposed to nano-TiO2. These contrasting results in digestive glands and gills were only evident at high concentration of nano-TiO2 and low pH. A 7 days recovery period was not sufficient to fully restore SOD, GPx, GST, GSH and MDA levels to levels before exposure to nano-TiO2 and low pH. Overall, our results confirmed that seawater acidification modulates effects of nanoparticles in mussels, and that gills are more sensitive to these stressors as compared with digestive glands.


Assuntos
Mytilus/fisiologia , Nanopartículas/toxicidade , Estresse Oxidativo/fisiologia , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Brânquias , Água do Mar/química
12.
Front Physiol ; 9: 166, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29559924

RESUMO

With the release of large amounts of CO2, ocean acidification is intensifying and affecting aquatic organisms. In addition, salinity also plays an important role for marine organisms and fluctuates greatly in estuarine and coastal ecosystem, where ocean acidification frequently occurs. In present study, flow cytometry was used to investigate immune parameters of haemocytes in the thick shell mussel Mytilus coruscus exposed to different salinities (15, 25, and 35‰) and two pH levels (7.3 and 8.1). A 7-day in vivo and a 5-h in vitro experiments were performed. In both experiments, low pH had significant effects on all tested immune parameters. When exposed to decreased pH, total haemocyte count (THC), phagocytosis (Pha), esterase (Est), and lysosomal content (Lyso) were significantly decreased, whereas haemocyte mortality (HM) and reactive oxygen species (ROS) were increased. High salinity had no significant effects on the immune parameters of haemocytes as compared with low salinity. However, an interaction between pH and salinity was observed in both experiments for most tested haemocyte parameters. This study showed that high salinity, low salinity and low pH have negative and interactive effects on haemocytes of mussels. As a consequence, it can be expected that the combined effect of low pH and changed salinity will have more severe effects on mussel health than predicted by single exposure.

13.
Chemosphere ; 196: 182-195, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29304456

RESUMO

Increased production of engineered nanoparticles (NPs) has raised extensive concerns about the potential toxic effects on marine organisms. Extensive evidences documented the impact of ocean acidification (OA) on the physiology and fitness of bivalves. In the present study, we investigated the biochemical responses of the mussel Mytilus coruscus exposed to both nano-ZnO and low pH relevant for ocean acidification conditions for 14 d followed by a 7-d recovery period. Most biochemical indexes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), acid phosphatase (ACP) and alkaline phosphatase (ALP)) measured in gills and hemocytes were increased when the mussels were subject to low pH or high concentration of nano-ZnO, suggesting oxidative stress responses. No significant interactions between the two stressors were observed for most measured parameters. After a 1 week recovery period, low pH and nano-ZnO had less marked impact for SOD, GPx, ACP and ALP in hemocytes as compared to the end of the 14 d exposure. However, no recovery was observed in gills. Overall, our results suggest that both low pH and nano-ZnO induce an anti-oxidative response in Mytilus coruscus with gills being more sensitive than hemocytes.


Assuntos
Mytilus/fisiologia , Nanopartículas/toxicidade , Água do Mar/química , Óxido de Zinco/toxicidade , Animais , Antioxidantes/metabolismo , Catalase/metabolismo , Monitoramento Ambiental , Brânquias/metabolismo , Glutationa Peroxidase/metabolismo , Hemócitos/efeitos dos fármacos , Homeostase , Concentração de Íons de Hidrogênio , Mytilus/metabolismo , Oceanos e Mares , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Óxido de Zinco/metabolismo
14.
Sci Total Environ ; 624: 820-830, 2018 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-29274606

RESUMO

Flow cytometry was used to investigate the immune parameters of haemocytes in thick-shell mussel Mytilus coruscus exposed to different concentrations of ZnO nanoparticles (NPs) (0, 2.5, and 10mgl-1) at two pH levels (7.3 and 8.1) for 14days following a recovery period of 7days. ZnO NPs significantly affected all of the immune parameters throughout the experiment. At high ZnO NPs concentrations, total haemocyte counting, phagocytosis, esterase, and lysosomal content were significantly decreased whereas haemocyte mortality and reactive oxygen species (ROS) were increased. Although low pH also significantly influenced all of the immune parameters of the mussels, its effect was not as strong as that of ZnO NPs. Interactive effects were observed between pH and ZnO NPs in most haemocyte parameters during the exposure period. Although a slight recovery from the stress of ZnO NPs and pH was observed for all immune parameters, significant carry-over effects of low pH and ZnO NPs were still detected. This study revealed that high concentration of ZnO NPs and low pH exert negative and synergistic effects on mussels, and these effects remain even after the mussels are no longer exposed to such stressors.


Assuntos
Hemócitos/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Mytilus/imunologia , Água do Mar/química , Óxido de Zinco/toxicidade , Animais , Esterases/metabolismo , Concentração de Íons de Hidrogênio , Lisossomos , Mytilus/efeitos dos fármacos , Fagocitose , Espécies Reativas de Oxigênio/metabolismo
15.
Front Physiol ; 8: 145, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28337153

RESUMO

The rising anthropogenic atmospheric CO2 results in the reduction of seawater pH, namely ocean acidification (OA). In East China Sea, the largest coastal hypoxic zone was observed in the world. This region is also strongly impacted by ocean acidification as receiving much nutrient from Changjiang and Qiantangjiang, and organisms can experience great short-term natural variability of DO and pH in this area. In order to evaluate the defense responses of marine mussels under this scenario, the thick shell mussel Mytilus coruscus were exposed to three pH/pCO2 levels (7.3/2800 µatm, 7.7/1020 µatm, 8.1/376 µatm) at two dissolved oxygen concentrations (DO, 2.0, 6.0 mg L-1) for 72 h. Results showed that byssus thread parameters, such as the number, diameter, attachment strength and plaque area were reduced by low DO, and shell-closing strength was significantly weaker under both hypoxia and low pH conditions. Expression patterns of genes related to mussel byssus protein (MBP) were affected by hypoxia. Generally, hypoxia reduced MBP1 and MBP7 expressions, but increased MBP13 expression. In conclusion, both hypoxia and low pH induced negative effects on mussel defense responses, with hypoxia being the main driver of change. In addition, significant interactive effects between pH and DO were observed on shell-closing strength. Therefore, the adverse effects induced by hypoxia on the defense of mussels may be aggravated by low pH in the natural environments.

16.
Sci Rep ; 7: 40015, 2017 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-28054631

RESUMO

The increasing usage of nanoparticles has caused their considerable release into the aquatic environment. Meanwhile, anthropogenic CO2 emissions have caused a reduction of seawater pH. However, their combined effects on marine species have not been experimentally evaluated. This study estimated the physiological toxicity of nano-TiO2 in the mussel Mytilus coruscus under high pCO2 (2500-2600 µatm). We found that respiration rate (RR), food absorption efficiency (AE), clearance rate (CR), scope for growth (SFG) and O:N ratio were significantly reduced by nano-TiO2, whereas faecal organic weight rate and ammonia excretion rate (ER) were increased under nano-TiO2 conditions. High pCO2 exerted lower effects on CR, RR, ER and O:N ratio than nano-TiO2. Despite this, significant interactions of CO2-induced pH change and nano-TiO2 were found in RR, ER and O:N ratio. PCA showed close relationships among most test parameters, i.e., RR, CR, AE, SFG and O:N ratio. The normal physiological responses were strongly correlated to a positive SFG with normal pH and no/low nano-TiO2 conditions. Our results indicate that physiological functions of M. coruscus are more severely impaired by the combination of nano-TiO2 and high pCO2.


Assuntos
Dióxido de Carbono/metabolismo , Mytilus/efeitos dos fármacos , Mytilus/fisiologia , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Concentração de Íons de Hidrogênio , Taxa de Depuração Metabólica/efeitos dos fármacos , Metabolismo/efeitos dos fármacos , Mytilus/crescimento & desenvolvimento , Nitrogênio/metabolismo , Oxigênio/metabolismo , Respiração/efeitos dos fármacos
17.
Ecotoxicol Environ Saf ; 137: 94-102, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27915148

RESUMO

Ocean acidification (OA) and hypoxic events are increasing worldwide problems, their interactive effects have not been well clarified, although their co-occurrence is prevalent. The East China Sea (the Yangtze River estuary area) suffers from not only coastal hypoxia but also pH fluctuation, representing an ideal study site to explore the combined effect of OA and hypoxia on marine bivalves. We experimentally evaluated the antioxidant response of the mussel Mytilus coruscus exposed to three pH levels (8.1, 7.7 and 7.3) at two dissolved oxygen (DO) levels (2.0mgL-1 and 6.0mgL-1) for 72h. Activities of superoxide dismutase, catalase, glutathione peroxidase, acid phosphatase, and alkaline phosphatase and levels of malondialdehyde were measured in gills and hemolymph. All enzymatic activities in hemolymph and gills followed a similar pattern throughout the experiment duration. Generally, low DO showed greater effects on enzyme activities than elevated CO2. Significant interactions between DO, pH and time were only observed at superoxide dismutase and catalase in both tissues. PCA revealed positive relationships between most enzyme activities in both gills and hemolymph with the exception of alkaline phosphatase activity and the level of malondialdehyde in the hemolymph. Overall, our results suggested that decreased pH and low DO induced similar antioxidant responses in the hard shelled mussel, and showed an additive effect on most enzyme activities. The evaluation of multiple environmental stressors, a more realistic scenario than single ones, is crucial to predict the effect of future global changes on coastal species and our results supply some insights on the potential combined effects of reduced pH and DO on marine bivalves.


Assuntos
Antioxidantes/metabolismo , Mytilus/efeitos dos fármacos , Oxigênio/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Dióxido de Carbono/metabolismo , Catalase/metabolismo , China , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Glutationa Peroxidase/metabolismo , Hemolinfa/metabolismo , Concentração de Íons de Hidrogênio , Mytilus/enzimologia , Estresse Oxidativo , Superóxido Dismutase/metabolismo
18.
Aquat Toxicol ; 180: 1-10, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27642706

RESUMO

With increasing production from nanotechnology industries, nanomaterials are inevitably released into the aquatic environment, thereby posing a potential risk to aquatic organisms. Thus, concerns have been raised on the potential ecotoxicological effect of nanoparticle. Furthermore, the ecotoxicological consequences caused by the interaction of nanoparticles with other environmental stresses, such as seawater acidification on marine animals, have not been evaluated. In particular, whether acidification enhances the susceptibility to nanoparticles in bivalves needs to be evaluated. In the present study, we investigated the combined effects of low pH and nanoscale titanium dioxide (nano-TiO2) on some immune parameters of hemocytes in the mussel Mytilus coruscus by flow cytometry under six combinations of two pH values (7.3 and 8.1) and three nano-TiO2 concentrations (0, 2.5, and 10mgL-1) for 14 d. Afterward, the mussels were shifted to normal conditions without nano-TiO2 at pH 8.1 for 7 d further to test their recovery from the multiple stresses. Total hemocyte count (THC), phagocytosis (Pha), esterase (Est), and lysosomal content (Lyso) decreased under low pH and high nano-TiO2 concentration conditions, whereas hemocyte mortality (HM) and reactive oxygen species (ROS) increased with nano-TiO2 concentrations under low pH conditions. The interactive effects between pH and nano-TiO2 were observed at the latter part of the exposure experiment (7 and 14 d) in most hemocyte parameters. Nano-TiO2 influenced the immune functions of mussel more severely than low pH. Slight recovery from the combined stresses was observed for HM, THC, Pha, and Lyso, but significant carry-over effects of nano-TiO2 and low pH were still observed. This study demonstrated that both low pH and high concentration of nano-TiO2 had negative effects on mussels, and these effects still acted for some time even though the mussels were already out of such stressors.


Assuntos
Hemócitos/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Nanopartículas Metálicas/toxicidade , Mytilus/efeitos dos fármacos , Água do Mar/química , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Relação Dose-Resposta a Droga , Citometria de Fluxo , Hemócitos/imunologia , Mytilus/imunologia , Distribuição Aleatória , Estresse Fisiológico/fisiologia , Testes de Toxicidade
19.
Springerplus ; 5(1): 1246, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27536529

RESUMO

This study aims to evaluate the effects of adding salt to water on the physiological parameters of the blood parrot cichlid (Cichlasoma synspilum ♀ × Cichlasoma citrinellum ♂). The blood parrot cichlid is a popular species in the aquarium trade because of its behaviour and beauty. Salt is usually added to water during the culture or transportation of this fish. However, the manner by which the fish adjusts its physiological responses to salinity change is unclear. The effects of salinity on serum osmolality, immune-related enzyme activities, Na(+)-K(+)-ATPase activities in the gill, skin carotenoid content and oxygen consumption were analysed. Blood parrotfish individuals were transferred from freshwater to water with four salinity levels (0.16, 2.5, 5 and 7.5 ‰) for 168 h, and physiological responses were evaluated at 0, 6, 12, 24 and 168 h. Results showed no significant differences in serum acid phosphatase and alkaline phosphatase activities, skin carotenoid content and oxygen consumption rate among the different groups. However, the serum osmolality at 6 h was significantly elevated. Moreover, salinity increase stimulated superoxide dismutase (SOD) activity from 0 to 6 h. SOD activity increased from 6 to 24 h but significantly reduced at 168 h when the fish were exposed to salt water. The SOD activity in the salinity 2.5 ‰ group recovered the initial level, whereas those in the salinity 5 and 7.5 ‰ groups decreased to levels lower than the initial level. The gill Na(+)-K(+)-ATPase activity significantly declined with time and salinity increase. Thus, adding an appropriate amount of salt can save energy consumption during osmoregulation and temporarily enhance the antioxidant activity of blood parrotfish. However, this strategy is insufficient for long-term culture. Therefore, adding salt to water only provides short-term benefit to blood parrot cichlid during transportation.

20.
Mar Pollut Bull ; 108(1-2): 46-52, 2016 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-27207025

RESUMO

Hypoxia often intensifies with rising dissolved CO2, but the concurrent effects of hypoxia and acidification on bivalves are largely unknown. In this study, immune responses of hemocytes in the mussel Mytilus coruscus were examined under six combinations of pH (7.3, 7.7 and 8.1) and dissolved oxygen (DO) concentrations (2mgL(-1), 6mgL(-1)) for 72h. Generally, total hemocyte account, phagocytosis, esterase and lysosomal content were reduced under low DO and pH conditions, whereas hemocyte mortality and reactive oxygen species production increased under low DO and pH. Both hypoxia and low pH have negative effects on mussels, but the effects of pH are not as strong as DO. Moreover, significant interactions between DO and pH occurred. However, acidification generally doesn't aggravate the effects induced by hypoxia. Acidification and hypoxia may increase disease risk and impact the aquaculture of this species.


Assuntos
Hemócitos/efeitos dos fármacos , Hipóxia , Mytilus/efeitos dos fármacos , Água do Mar/química , Animais , Concentração de Íons de Hidrogênio
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