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1.
J Exp Zool B Mol Dev Evol ; 338(4): 215-224, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34855303

RESUMO

In this study, we have identified the entire complement of typical homeobox (Hox) genes (Lab, Pb, Dfd, Scr, Antp, Ubx, Abd-A, and Abd-B) in harpacticoid and calanoid copepods and compared them with the cyclopoid copepod Paracyclopina nana. The harpacticoid copepods Tigriopus japonicus and Tigriopus kingsejongensis have seven Hox genes (Lab, Dfd, Scr, Antp, Ubx, Abd-A, and Abd-B) and the Pb and Ftz genes are also present in the cyclopoid copepod P. nana. In the Hox gene cluster of the calanoid copepod Eurytemora affinis, all the Hox genes were present linearly in the genome but the Antp gene was duplicated. Of the three representative copepods, the P. nana Hox gene cluster was the most compact due to its small genome size. The Hox gene expression profile patterns in the three representative copepods were stage-specific. The Lab, Dfd, Scr, Pb, Ftz, and Hox3 genes showed a high expression in early developmental stages but Antp, Ubx, Abd-A, and Abd-B genes were mostly expressed in later developmental stages, implying that these Hox genes may be closely associated with the development of segment identity during early development.


Assuntos
Copépodes , Genes Homeobox , Animais , Copépodes/genética , Medicamentos de Ervas Chinesas , Chumbo/química , Família Multigênica
2.
Ecotoxicol Environ Saf ; 230: 113171, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34999339

RESUMO

Metal pollution provide a substantial challenge for environmental health. This study investigated the multigeneration effects of cadmium on populations of the copepod species Pseudodiaptomus annandalei, exposed to a sublethal concentration, 40 µg/L of cadmium (Cd), over 10 generations. At the end of each generation, copepod individuals were collected to estimate fecundity, bioaccumulation, and real time qPCR quantification of selected differentially expressed genes to evaluate Cd effects and sex-specific responses of copepods across multiple generations. Our results revealed a sex-specific accumulation of Cd integrating 10 successive generations. The concentration of Cd was significantly higher (p < 0.05) in males than in females. We also observed a generational increase in Cd accumulation. Fecundity increased, with the exception of the first generation, possibly as a compensation for a decrease of copepod population size under Cd exposure. Protein expression of copepods exposed to Cd occurred in a sex-specific manner. Hemerythrin was mostly up-regulated in both copepod sexes exposed to Cd with males having the highest expression levels, while heat shock protein 70 was mostly up-regulated in males and down-regulated in female copepods, both exposed to Cd. Although copepods are known to develop adaptive mechanisms to tolerate toxic chemicals, continuous exposure to metals could lead to the bioaccumulation of metals in their offspring through maternal transfer and direct uptake from the medium over several generations. As a consequence, increased metal concentrations in copepods could result in physiological damage, reducing their fitness, and possibly compromise copepod population structures. This study showed that mortality, life history traits and molecular responses of a copepod species provided important toxicological endpoints and bio-markers for environmental risk assessments. Environmental pressure resulting from continuous exposure to persistent pollutants like Cd, could have evolutionary significance. The tendency for copepods to selectively adapt to a toxic environment through modifications, could increase their chance of survival over a long term.

3.
Glob Chang Biol ; 26(11): 6413-6423, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32869344

RESUMO

Understanding how ecosystems will respond to climate changes requires unravelling the network of functional responses and feedbacks among biodiversity, physicochemical environments, and productivity. These ecosystem components not only change over time but also interact with each other. Therefore, investigation of individual relationships may give limited insights into their interdependencies and limit ability to predict future ecosystem states. We address this problem by analyzing long-term (16-39 years) time series data from 10 aquatic ecosystems and using convergent cross mapping (CCM) to quantify the causal networks linking phytoplankton species richness, biomass, and physicochemical factors. We determined that individual quantities (e.g., total species richness or nutrients) were not significant predictors of ecosystem stability (quantified as long-term fluctuation of phytoplankton biomass); rather, the integrated causal pathway in the ecosystem network, composed of the interactions among species richness, nutrient cycling, and phytoplankton biomass, was the best predictor of stability. Furthermore, systems that experienced stronger warming over time had both weakened causal interactions and larger fluctuations. Thus, rather than thinking in terms of separate factors, a more holistic network view, that causally links species richness and the other ecosystem components, is required to understand and predict climate impacts on the temporal stability of aquatic ecosystems.


Assuntos
Biodiversidade , Ecossistema , Biomassa , Mudança Climática , Fitoplâncton
4.
Proc Natl Acad Sci U S A ; 114(52): E11199-E11207, 2017 12 26.
Artigo em Inglês | MEDLINE | ID: mdl-29229858

RESUMO

Calanoid copepods are among the most abundant metazoans in the ocean and constitute a vital trophic link within marine food webs. They possess relatively narrow swimming capabilities, yet are capable of significant self-locomotion under strong hydrodynamic conditions. Here we provide evidence for an active adaptation that allows these small organisms to adjust their motility in response to background flow. We track simultaneously and in three dimensions the motion of flow tracers and planktonic copepods swimming freely at several intensities of quasi-homogeneous, isotropic turbulence. We show that copepods synchronize the frequency of their relocation jumps with the frequency of small-scale turbulence by performing frequent relocation jumps of low amplitude that seem unrelated to localized hydrodynamic signals. We develop a model of plankton motion in turbulence that shows excellent quantitative agreement with our measurements when turbulence is significant. We find that, compared with passive tracers, active motion enhances the diffusion of organisms at low turbulence intensity whereas it dampens diffusion at higher turbulence levels. The existence of frequent jumps in a motion that is otherwise dominated by turbulent transport allows for the possibility of active locomotion and hence to transition from being passively advected to being capable of controlling diffusion. This behavioral response provides zooplankton with the capability to retain the benefits of self-locomotion despite turbulence advection and may help these organisms to actively control their distribution in dynamic environments. Our study reveals an active adaptation that carries strong fitness advantages and provides a realistic model of plankton motion in turbulence.


Assuntos
Copépodes/fisiologia , Modelos Biológicos , Natação/fisiologia , Zooplâncton/fisiologia , Animais
5.
Ecotoxicol Environ Saf ; 204: 111048, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32758697

RESUMO

In this study, the whole transcriptome and sex-specific differential gene expression of the copepod Pseudodiaptomus annandalei exposed to cadmium (Cd) were investigated. P. annandalei were exposed to 40 µg/L Cd from the naupliar stage to male and female adults. High-throughput transcriptome sequencing (RNA-seq) was performed with copepod samples using an Illumina Hiseq™ 2000 platform. TransDecoder analysis found 32,625 putative open reading frame contigs. At p-values of <0.001, a total of 4756 differentially expressed genes (DEGs) (2216 up-regulated and 2540 down-regulated genes) were found in male copepods. Whereas a total of 2879 DEGs (2007 up-regulated and 872 down-regulated genes) were found in female copepods. A few selected cellular stress response genes, involved in xenobiotic metabolism, energy metabolism, growth, and development as a result of Cd exposure in the copepods were discussed. The study showed that most of these processes were changed in a sex-specific manner, accounting for the different sensitivities of male and female copepods. Results suggest and reinforce that sex is an important factor to be considered in ecotoxicogenomics.


Assuntos
Cádmio/toxicidade , Copépodes/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Copépodes/genética , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Masculino , Fatores Sexuais
6.
Microb Pathog ; 116: 113-119, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29339308

RESUMO

Bacterial infectious diseases are a main dangerous problem in Aquaculture farming. It causes multiple diseases in fish as well as in human being and it has considerable virulence potential. In this connection, the moot of study focus to discriminate bacterial isolates recovered from naturally diseased Labeo rohita fish and their virulent characteristics. Based on the ß-haemolysis factor, four isolates (KADR11, KADR12, KADR13 and KADR14) were selected for further delineation. These bacterial isolates showed high similarity with Providencia rettgeri, Aeromonas sp., Aeromonas sp. and Aeromonas enteropelogenes respectively, using partial 16S r-RNA gene amplification and biochemical characterizations were also supported. The further study investigates the virulence characteristics of isolates showed separation of outer membrane proteins (OMPs) and lipopolysaccharides (LPS) which appeared between 19_80 kDa and 20_100 kDa in SDS_PAGE analysis respectively. All the four strains were complete resistant (100%) to ß-lactam antibiotics. L. rohita were injected intraperitoneally with 0 (control), 2.0 × 104, 2.0 × 105, 2.0 × 106, 2.0 × 107 and 2.0 × 108 cells/fish of Providencia rettgeri KADR11, Aeromonas sp. KADR12, Aeromonas sp. KADR13 and Aeromonas enteropelogenes KADR14 for the determination of lethal dose 50 (LD50) values, which were 2.4 × 107, 4.1 × 105, 2.7 × 107 and 7.4 × 105 cells/fish respectively. The results indicated that isolated strains were possessed the high pathogenic potential for L. rohita.


Assuntos
Aeromonas/isolamento & purificação , Cyprinidae , Farmacorresistência Bacteriana , Infecções por Enterobacteriaceae/veterinária , Doenças dos Peixes/microbiologia , Providencia/isolamento & purificação , Fatores de Virulência/análise , Aeromonas/efeitos dos fármacos , Aeromonas/patogenicidade , Animais , Técnicas de Tipagem Bacteriana , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Infecções por Enterobacteriaceae/microbiologia , Água Doce , Dose Letal Mediana , Filogenia , Providencia/efeitos dos fármacos , Providencia/patogenicidade , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
7.
Fish Shellfish Immunol ; 70: 408-415, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28917486

RESUMO

The aim of the present study was to evaluate the dietary administration of Bacillus aerophilus KADR3 on enhancing the immunity and disease resistance against Aeromonas hydrophila infection in Labeo rohita. B. aerophilus culture supernatant exhibited antagonistic activity against fish pathogenic bacteria in an agar well diffusion assay. Four fish groups were fed with either of following diets containing different concentrations of B. aerophilus KADR3 (cfu g-1): 0 (control), 1 × 107 (DI), 1 × 108 (DII), and 1 × 109 (DIII) -cfu g-1. Various innate immune parameters were measured at - 3rd and 6th - week post-feeding. At the end of 6th week, fish were challenged intraperitoneally with A. hydrophila and survival percentage was recorded over 10 days post-challenge. Studied immunological parameters viz. serum lysozyme, phagocytosis, serum total protein, respiratory bursts, serum IgM levels, superoxide dismutase and alternative complement pathway activities were significantly enhanced (P < 0.05) in fish groups fed with B. aerophilus KADR3 supplemented diets, with the highest values were observed in DII (108 cfu g-1) fed group. Further, B. aerophilus supplementation at 108 cfu g-1 exhibited highest post-challenge survivability i.e. 72.83%, followed by DIII (64.19%) and DI (41.97%). Our results collectively suggest that B. aerophilus can potentially be used as probiotic strain in aquaculture to enhance the immunity and disease resistance with an optimal dietary supplementation of 108 cfu g-1.


Assuntos
Bacillus/química , Cyprinidae/imunologia , Resistência à Doença/efeitos dos fármacos , Doenças dos Peixes/imunologia , Imunidade Inata/efeitos dos fármacos , Probióticos/farmacologia , Aeromonas hydrophila/fisiologia , Ração Animal/análise , Animais , Dieta/veterinária , Infecções por Bactérias Gram-Negativas/imunologia , Probióticos/administração & dosagem , Distribuição Aleatória
8.
Ecotoxicology ; 26(9): 1227-1239, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28990129

RESUMO

This study determined the effect of cadmium (Cd) toxicity comparatively on two copepods, Eurytemora affinis (Poppe 1880) from a temperate region (Seine Estuary, France) and Pseudodiaptomus annandalei (Sewell 1919) from a subtropical region (Danshuei Estuary, Taiwan), according to their sex and reproductive stages. In addition, the effect of Cd to their life cycle traits was quantified. In the first experiment, both copepod sexes were exposed to 40, 80, 150, 220, and 360 µg/L of Cd and a control cultured in salinity 15, except that the temperature was 18 °C for E. affinis and 26 °C for P. annandalei. This allowed calculating median lethal concentration (LC50) of Cd after 96 h. This was 120.6 µg/L Cd for P. annandalei males which were almost twice as sensitive as P. annandalei females (LC50 = 239.5 µg/L Cd). For E. affinis females, the LC50 was 90.04 µg/L Cd, reflecting a 1.4 times higher sensitivity of females than of males (LC50 = 127.75 µg/L Cd). The males of both species were similarly sensitive; however, the E. affinis females were 2.7 times more sensitive than the P. annandalei females. We also compared the sensitivity of ovigerous females (OVF) and non-ovigerous females (NOF) of both species to Cd. Mortality was higher in NOF than in OVF of both copepod species in both the control and the 40 µg/L Cd treatment. Finally, the total population, fecundity and female morphology of both copepod species were estimated after exposing one generation cycle (nauplius to adult) to 40 µg/L Cd (for E. affinis) and 160 µg/L Cd (for P. annandalei). A significant decrease in cohort production, survival and clutch size but no significant difference in the prosome length of both copepod species exposed to Cd were detected. The ratio of OVF:NOF was high in both copepod species exposed to Cd. Cd toxicity did not significantly affect the M:F sex ratio and % OVF of E. affinis. However, the effect of Cd toxicity in P. annandalei was significant in the M:F sex ratio and was in favor of females and their reproductive activities due to an increase in % OVF. Moreover, there was a significant decrease in total production of P. annandalei due to high mortality in their nauplii and copepodid developmental stages. Toxicity to Cd appears to be affected by multiple factors including sex, reproductive life stage and species. The ecological implication of Cd toxicity on E. affinis and P. annandalei copepod ecology is more related to a skewed sex ratio, low egg production, reduced hatchability and reduced survival that affects the recruitment potential of the copepod nauplii resulting in a decreasing copepod population. Mortality, reproduction and population growth of model species may provide important bio-indicators for environmental risk assessment.


Assuntos
Cádmio/toxicidade , Copépodes/fisiologia , Estágios do Ciclo de Vida/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Copépodes/efeitos dos fármacos , Feminino , Masculino , Testes de Toxicidade
9.
Bull Environ Contam Toxicol ; 98(3): 392-399, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27864583

RESUMO

This study is focused on the removal, accumulation and degradation of three environmental ubiquitous polycyclic aromatic hydrocarbons (PAHs), phenanthrene (PHE), fluoranthene (FLA) and pyrene (PYR), by the marine alga Rhodomonas baltica enriched from the English Channel. After separation, purification and culture in several phases, R. baltica was exposed to PAH concentrations that are frequently encountered in the field in several anthropized environments. The results showed that R. baltica can grow under PAH stress, efficiently remove up to 70% of these compounds from the medium by 216 h of culture and selectively bioaccumulate PAHs by their hydrophobicity. Between PHE, FLA and PYR, phenanthrene was the compound with higher degradation rates throughout incubation. The equilibrium partitioning theoretical approach showed that physico-chemical partitioning, rather than active bioconcentration, was the major factor governing the bioaccumulation, outlying a potential application in decontamination processes for this species.


Assuntos
Biodegradação Ambiental , Fluorenos/análise , Phaeophyceae/metabolismo , Fenantrenos/análise , Pirenos/análise
10.
Tunis Med ; 95(5): 341-346, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-29509215

RESUMO

BACKGROUND: The objective of our study was to evaluate the predictors of repeat visits at Emergency Department (ED) in patients aged ≥ 65 years. METHODS: A prospective observational study was conducted over a month. Inclusion:  patients (age> = 65 year) seen in the ED and leaving the same day. The epidemiological and clinical characteristics at the first visit (index visit (IV)) were collected. The Identification of Senior At Risk (ISAR) score was used to assess our patients. The number of visits (n ≥ 2) to ED within 30 days of the IV was estimated by a phone contact. RESULTS: Inclusion of125 patients. Mean age = 76 +/- 7 years. The sex ratio was 0.85. Twenty five percent of our patients made repeat visits the following period. Univariate analysis identified: age> 75 years, mean ISAR score>2, history of renal failure, ED visit a month prior to the IV, hospitalization in the last 6 months, patients who depend on someone else help at home and those taking more than 3 medications daily. In multivariate analysis, ED visit a month prior to the IV, hospitalization in the last 6 months, and patients who depend on someone else help at home were independent factors of repeat visits to the ED. CONCLUSION:   Efforts to identify patients at high risk of repeat visits to the ED should be made.


Assuntos
Serviços Médicos de Emergência/estatística & dados numéricos , Serviço Hospitalar de Emergência/estatística & dados numéricos , Readmissão do Paciente/estatística & dados numéricos , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Prognóstico , Recidiva , Encaminhamento e Consulta/estatística & dados numéricos , Fatores de Risco , Tunísia/epidemiologia
11.
Tunis Med ; 95(12): 229-235, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29878290

RESUMO

BACKGROUND: Acute coronary syndrome without persistent ST segment elevation (NSTE-ACS) is a major public health problem. It has been the subject of numerous studies but little has been published from the emergency department (ED). OBJECTIVE: Describe the epidemiology, clinical features, management and prognosis of patients with NSTE-ACS presenting to ED. METHODS: Prospective, observational, over four years study (2011-2015). INCLUSION CRITERIA: patients (> 18 years of age) presenting consecutively to ED with the diagnosis of NSTE-ACS. Collection of epidemiological, clinical and therapeutic features. Calculation of ischemic risk (TIMI and GRACE) and bleeding risk (CRUSADE) score. Prognosis (death and ischemic events) was evaluated at six months.  Results: Inclusion of 390 patients. Mean age = 61 ± 11 years. Sex-ratio = 1.46. Cardio-vascular risk factors (%):  hypertension (60), Mellitus diabetes (47), dyslipidemia (29) and smoking (26).   The median TIMI and GRACE scores were equal to 3 and 112 respectively. The median CRUSADE score was 29. Electrocardiographic findings (%): ST segment depression (43), T wave depression (24) and no ischemic changes (26).Initial management in the ED (%):  anti-ischaemic agents (43), antiplatelet agents (Acetylsalicylic acid (90), Clopidogrel (70)) and anticoagulants (70). Coronary angiography was done in all patients: early in 71% of patients and elective in 29% of patients.Prognosis at 6 months (%): recurrence of angina (24), infraction (9) and mortality (5). CONCLUSION: Patients with NSTE-ACS are predominantly male. The main risk factors are hypertension, mellitus diabetes and dyslipidemia. The prognosis was good with a mortality rate of 5%.


Assuntos
Síndrome Coronariana Aguda/diagnóstico , Síndrome Coronariana Aguda/epidemiologia , Serviço Hospitalar de Emergência/estatística & dados numéricos , Síndrome Coronariana Aguda/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiografia Coronária , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Admissão do Paciente/estatística & dados numéricos , Prognóstico , Medição de Risco , Fatores de Risco , Infarto do Miocárdio com Supradesnível do Segmento ST/epidemiologia , Tunísia/epidemiologia
12.
Tunis Med ; 95(1): 45-52, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29327768

RESUMO

INTRODUCTION: Studies report that anaphylaxis was under-diagnosed in emergency department (ED) and emergency management was often in disagreement with international recommendations. AIM OF THE STUDY: The aim of this study was to describe the epidemiology, clinical features, management and outcome of patients with anaphylaxis presenting to an ED. METHODS: Prospective, observational study over four years (June 2010 to May 2014). INCLUSION CRITERIA: patients (> 14 years of age) presenting consecutively to the ED with the diagnosis of anaphylaxis. Collection of epidemiological, clinical and therapeutic parameters Results: During the study, 239 patients were enrolled. Mean age = 40±15 years. Sex-ratio=0.8.  History of anaphylaxis was reported in 40% of cases. Clinical features n (%): cutaneous features 229 (96), cardiovascular features 124 (52), respiratory features 127 (53), gastrointestinal features 48 (20) and neurologic features 4 (10). Most common allergens: drugs 62%, food 24% and insects 4%. No causes were apparent in 8% of cases. An anaphylactic shock was recorded in 73 patients (31%). Adrenaline was used in 83%of patients, intravenously in 31%.  Corticosteroids and histamine H1 antagonist were prescribed in 98 and 51% respectively. Biphasic reactions were reported in three patients. There was no death cases registered. CONCLUSION: Our results showed that the prevalence of anaphylaxis was low.This demonstrates that anaphylaxis is a situation which remains underestimated. It is therefore imperative to conduct prospective multicenter studies in emergency services for better determination of its impact and its risk factors.


Assuntos
Anafilaxia/epidemiologia , Anafilaxia/terapia , Emergências/epidemiologia , Serviços Médicos de Emergência , Adolescente , Adulto , Idoso , Anafilaxia/diagnóstico , Anafilaxia/patologia , Progressão da Doença , Serviços Médicos de Emergência/estatística & dados numéricos , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
13.
J Exp Zool B Mol Dev Evol ; 326(2): 105-9, 2016 03.
Artigo em Inglês | MEDLINE | ID: mdl-26833546

RESUMO

We report the first identification of the entire complement of the eight typical homeobox (hox) genes (lab, pb, Dfd, scr, antp, ubx, Abd-A, and Abd-B) and the ftz gene in a 192.8 kb region in the cyclopoid copepod Paracyclopina nana. A Hox3 gene ortholog was not present in the P. nana hox gene cluster, while the P. nana Dfd gene was transcribed in the opposite direction to the Daphnia pulex Dfd gene, but in the same direction as the Dfd genes of the fruit fly Drosophila melanogaster and red flour beetle Tribolium castaneum. The location of the lab and pb genes was switched in the P. nana hox cluster, while the order of the remaining hox genes was generally conserved with those of other arthropods. J. Exp. Zool. (Mol. Dev. Evol.) 9999B:XX-XX, 2016. © 2016 Wiley Periodicals, Inc.


Assuntos
Copépodes/metabolismo , Regulação da Expressão Gênica/fisiologia , Rearranjo Gênico , Proteínas de Homeodomínio/metabolismo , Animais , Sequência Conservada , Copépodes/genética , Variação Genética , Proteínas de Homeodomínio/genética , Família Multigênica , Especificidade da Espécie
14.
Environ Sci Technol ; 50(16): 8849-57, 2016 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-27438693

RESUMO

In this study, we evaluated accumulation and adverse effects of ingestion of microplastics in the monogonont rotifer (Brachionus koreanus). The dependence of microplastic toxicity on particle size was investigated by measuring several in vivo end points and studying the ingestion and egestion using 0.05-, 0.5-, and 6-µm nonfunctionalized polystyrene microbeads. To identify the defense mechanisms activated in response to microplastic exposure, the activities of several antioxidant-related enzymes and the phosphorylation status of mitogen-activated protein kinases (MAPKs) were determined. Exposure to polystyrene microbeads of all sizes led to significant size-dependent effects, including reduced growth rate, reduced fecundity, decreased lifespan and longer reproduction time. Rotifers exposed to 6-µm fluorescently labeled microbeads exhibited almost no fluorescence after 24 h, while rotifers exposed to 0.05- and 0.5-µm fluorescently labeled microbeads displayed fluorescence until 48 h, suggesting that 6-µm microbeads are more effectively egested from B. koreanus than 0.05- or 0.5-µm microbeads. This observation provides a potential explanation for our findings that microbead toxicity was size-dependent and smaller microbeads were more toxic. In vitro tests revealed that antioxidant-related enzymes and MAPK signaling pathways were significantly activated in response to microplastic exposure in a size-dependent manner.


Assuntos
Estresse Oxidativo , Rotíferos/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo
15.
Tunis Med ; 94(11): 674, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28994871

RESUMO

INTRODUCTION: The vitamin K antagonists (VKAs) are currently the most effective therapeutic class for the prevention of cerebrovascular eventsin atrial fibrillation (AF) patients. However, several studies showed an under-prescription of this therapy.The aim of the study was to assess the prescription of VKAs in non-valvular AF (NVAF) patients and factors influencing the non-prescription ofsuch treatment. METHODS: We conducted a prospective, observational study in an emergency department (ED). Patients with high thromboembolic risk NVAFand not receiving VKAs beforehand were included. Calculation of CHA2DS2-VASc and HAS-BLED scores was performed. An analytic study wasconducted in order to identify independent predictors of the under-prescription of VKAs. RESULTS: During study, 176 patients were enrolled, the mean age was 67±13 years and 66% were women. The mean CHA2DS2VASc andHASBLED scores were 2.88 ± 1.55 and 1.52 ± 1.05, respectively. Among our cohort, VKA was prescribed in 36% of cases. Age >70 years(OR=1.59, 95%CI[1.11-2.21],p<0.001), creatinine level ≥110 µmol/l (OR=2.54,95%CI[1.20-5.37],p=0.01) and aspirin use (OR =1.7,95%CI [1.08-2.67],p=0.02) were independently associated with under-prescription of VKAs. Bedside, the main causes reported by the emergency physicians(EP) were: factors related to patient characteristics (n=38,34%), factors related to emergency physician (n=62,55%), factors related to the patientenvironment (n=20,17%) and factors related to the drug (n=22,23%). CONCLUSIONS: Our results showed that the prescription of VKAs was low in ED. The reasons of VKA under-prescription are linked usually toseveral factors inherent to patient and to the adherence of EP to new recommendations.


Assuntos
Anticoagulantes/uso terapêutico , Fibrilação Atrial/complicações , Acidente Vascular Cerebral/prevenção & controle , Vitamina K/antagonistas & inibidores , Idoso , Idoso de 80 Anos ou mais , Serviço Hospitalar de Emergência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Acidente Vascular Cerebral/etiologia
16.
J Struct Biol ; 191(2): 224-35, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26057347

RESUMO

Pseudodiaptomus marinus copepods are small crustaceans living in estuarine areas endowed with exceptional swimming and adaptative performances. Since the external cuticle acts as an impermeable barrier for most dyes and molecular tools for labeling copepod proteins with fluorescent tags are not available, imaging cellular organelles in these organisms requires label free microscopy. Complementary nonlinear microscopy techniques have been used to investigate the structure and the response of their myofibrils to abrupt changes of temperature or/and salinity. In contrast with previous observations in vertebrates and invertebrates, the flavin autofluorescence which is a signature of mitochondria activity and the Coherent Anti-Stokes Raman Scattering (CARS) pattern assigned to T-tubules overlapped along myofibrils with the second harmonic generation (SHG) striated pattern generated by myosin tails in sarcomeric A bands. Temperature jumps from 18 to 4 °C or salinity jumps from 30 to 15 psu mostly affected flavin autofluorescence. Severe salinity jumps from 30 to 0 psu dismantled myofibril organization with major changes both in the SHG and CARS patterns. After a double stress (from 18 °C/30 psu to 4° C/0 psu) condensed and distended regions appeared within single myofibrils, with flavin autofluorescence bands located between sarcomeric A bands. These results shed light on the interactions between the different functional compartments which provide fast acting excitation-contraction coupling and adequate power supply in copepods muscles.


Assuntos
Copépodes/ultraestrutura , Miofibrilas/ultraestrutura , Imagem Óptica/métodos , Estresse Fisiológico , Animais , Copépodes/fisiologia , Miofibrilas/fisiologia , Sarcômeros/ultraestrutura , Temperatura
17.
Eur Phys J E Soft Matter ; 38(10): 108, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26490249

RESUMO

We consider Lagrangian velocity differences of zooplankters swimming in still water and in turbulence. Using cumulants, we quantify the intermittency properties of their motion recorded using three-dimensional particle tracking velocimetry. Copepods swimming in still water display an intermittent behaviour characterized by a high probability of small velocity increments, and by stretched exponential tails. Low values arise from their steady cruising behaviour while heavy tails result from frequent relocation jumps. In turbulence, we show that at short time scales, the intermittency signature of active copepods clearly differs from that of the underlying flow, and reflects the frequent relocation jumps displayed by these small animals. Despite these differences, we show that copepods swimming in still and turbulent flow belong to the same intermittency class that can be modelled by a log-stable model with non-analytical cumulant generating function. Intermittency in swimming behaviour and relocation jumps may enable copepods to display oriented, collective motion under strong hydrodynamic conditions and thus, may contribute to the formation of zooplankton patches in energetic environments.


Assuntos
Movimento , Zooplâncton/fisiologia , Animais , Copépodes/fisiologia , Hidrodinâmica
18.
Tunis Med ; 92(2): 147-53, 2014 Feb.
Artigo em Francês | MEDLINE | ID: mdl-24938237

RESUMO

BACKGROUND: Fibrinolysis during ST elevation myocardial infarction (STEMI) is feasible in the emergency departments (ED), and this reduces the delay from first medical contact to coronary reperfusion. The aim of the study is to: 1) Evaluate fibrinolysis with streptokinase (SK) in STEMI admitted to the ED. 2) identify clinical criteria predictive of fibrinolysis success. METHODS: prospective study (July 2008-March 2012). Inclusion of STEMI thrombolysed by SK. Fibrinolysis success was defined according to clinical and Electrocardiogram criteria. Multivariate study is used to identify the factors associated with thrombolysis success. RESULTS: Out of the 329 STEMI enrolled during the study period, 224 (68%) were thrombolysed. Mean age = 57 ± 11 years (20-86 years) sex ratio = 6. The average time chest pain - emergency admission was 195 ± 177 min (15 min to 12 hours). The 2/3 of patients had consulted during the first 3 hours. The average success rate of thrombolysis was 59% and reached 83% the first hour, 66% the second hour and 58.7% the third hour. In multivariate analysis, the three independent predictors factors of a fibrinolysis success were: active smoking, current treatment with beta blockers and the delay from onset chest pain to the ED visit less than 180 min. Conversely, diabetes was associated with fibrinolysis failure. Fibrinolysis got complicated by two intracerebral hemorrhages. Three patients had died in the ED. CONCLUSION: Two thirds of patients with STEMI have consulted 3 h after onset of chest pain. Fibrinolysis with streptokinase was effective in 59% of cases.


Assuntos
Tempo de Lise do Coágulo de Fibrina/métodos , Fibrinólise , Fibrinolíticos , Infarto do Miocárdio/diagnóstico , Estreptoquinase , Adulto , Idoso , Idoso de 80 Anos ou mais , Eletrocardiografia , Serviço Hospitalar de Emergência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Admissão do Paciente , Prognóstico , Adulto Jovem
19.
Sci Total Environ ; 943: 173574, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38823721

RESUMO

Mercury is a hazardous heavy metal that is distributed worldwide in aquatic ecosystems. Methylmercury (MeHg) poses significant toxicity risks to aquatic organisms, primarily through bioaccumulation and biomagnification, due to its strong affinity for protein thiol groups, which results in negative effects even at low concentrations. MeHg exposure can cause various physiological changes, oxidative stress, neurotoxicity, metabolic disorders, genetic damage, and immunotoxicity. To assess the risks of MeHg contamination in actual aquatic ecosystems, it is important to understand how MeHg interacts with environmental factors such as temperature, pH, dissolved organic matter, salinity, and other pollutants such as microplastics and organic compounds. Complex environmental conditions can cause potential toxicity, such as synergistic, antagonistic, and unchanged effects, of MeHg in aquatic organisms. This review focuses on demonstrating the toxic effects of single MeHg exposure and the interactive relationships between MeHg and surrounding environmental factors or pollutants on aquatic organisms. Our review also recommends further research on biological and molecular responses in aquatic organisms to better understand the potential toxicity of combinational exposure.


Assuntos
Organismos Aquáticos , Compostos de Metilmercúrio , Poluentes Químicos da Água , Compostos de Metilmercúrio/toxicidade , Organismos Aquáticos/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Monitoramento Ambiental
20.
Chemosphere ; 360: 142302, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38763394

RESUMO

Nickel compounds in dissolved form or as nanoparticles may affect planktonic invertebrates in marine ecosystems. Here, we assessed the physiological (naupliar mortality, egg production, egg hatching success) and molecular (quantitative gene expression) responses of the crustacean copepods Acartia clausi (indigenous Mediterranean species) and Acartia tonsa (model organism in ecotoxicology), to nickel nanoparticles (NiNPs) and nickel chloride (NiCl2), over time. We also measured NPs size and the temporal release of Ni ions in aqueous solution, through dynamic light scattering (DLS) and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. Nauplii of A. clausi were highly vulnerable to NiCl2 in the 48 h acute test, with an EC50 in the range of Ni concentrations measured in polluted waters. Females of both species exhibited a decreased egg production and hatching success after the 4-day exposure to NiNPs. Molecular responses in A. clausi incubated in NiNPs and NiCl2 showed a stronger up- or down-regulation, compared to A. tonsa, of genes associated with detoxification (phospholipid-hydroperoxide glutathione peroxidase, glutathione-S-transferase sigma), oxidative stress (superoxide dismutase), nervous system functioning (acetylcholinesterase), and oogenesis (vitellogenin). In conclusion, new information was here obtained on the effects of different forms of nickel on physiological and molecular responses of A. clausi, that could help to identify biomarker genes of exposure to be used as early-warning indicators. Our results also highlighted the need of employing indigenous copepod species to better evaluate the ecotoxicological impact of pollutants in different geographical area.


Assuntos
Copépodes , Nanopartículas Metálicas , Níquel , Poluentes Químicos da Água , Animais , Níquel/toxicidade , Copépodes/efeitos dos fármacos , Copépodes/fisiologia , Poluentes Químicos da Água/toxicidade , Nanopartículas Metálicas/toxicidade , Feminino , Estresse Oxidativo/efeitos dos fármacos
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