22,735 research outputs found

    Efeitos da sertralina no peixe-zebra (Danio rerio)

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    The increasing consumption of antidepressants has resulted in its presence in the aquatic environment. This fact has aroused concerns in the scientific community since these biologically active compounds can affect non-target organisms that have physiological systems regulated by these pharmaceuticals. Sertraline (SER) is an antidepressant belonging to the serotonin reuptake inhibitors class (SSRI) and has a high consumption rate. However, there is little knowledge about the toxicological effects of SER in aquatic systems. Thereby, in the Chapter 2 of the present work, a review of the available literature, published in the last five years, addressing levels of antidepressants and its metabolites in rivers, surface waters, tap water, and wastewater treatment plants, as well, the effects reported in fish and invertebrates. Overall, the available laboratory studies show that antidepressants can disrupt multiple biological processes in aquatic organisms, having a detrimental effect. Thus, this study aims to evaluate the short-term (0.1 up to 3000 ¬Ķg.L-1 ) and long-term (2 up to 1000√ó103 ng.L-1 ) effects of SER on zebrafish (Danio rerio) assessing different endpoints, such as development (e.g., mortality, spontaneous movements, equilibrium, abnormalities and heartbeat rate), biochemical markers associated with neurotransmission (acetylcholinesterase (AChE)), antioxidant defences (catalase (CAT), glutathione S-tranferases (GSTs)), energy metabolism (lactate dehydrogenase (LDH)) and behaviour (response to light/dark stimulus). Zebrafish embryos demonstrated sensitivity to SER concentrations during development (e.g., decreased spontaneous movements and increased/decreased heartbeat rate, depending on the exposed concentration). Regarding biochemical biomarkers assessed, in short-term exposure GSTs activity was significantly increased, and both in short- and long-term exposures the enzymatic activity of LDH was significantly increased. The responses to light/dark stimulus were generally decreased in short-term exposure, whereas the responses were increased in long-term exposure. These findings support further research on the long-term effects of antidepressants such as SER to aquatic biota and the development new methodologies to efficiently remove them from the environment.O consumo de antidepressivos tem vindo a aumentar, resultando na sua presen√ßa no meio aqu√°tico. Este facto tem suscitado preocupa√ß√Ķes na comunidade cient√≠fica, dado que estes compostos biologicamente ativos podem afetar organismos n√£o-alvo que apresentam sistemas fisiol√≥gicos regulados por estes f√°rmacos. A sertralina (SER) √© um antidepressivo pertencente √† classe dos inibidores seletivos da recapta√ß√£o de serotonina (SSRI), com uma elevada taxa de utiliza√ß√£o. No entanto, apesar do seu elevado consumo, a informa√ß√£o relativa aos seus efeitos t√≥xicos nos sistemas aqu√°ticos √© limitada. Deste modo, no Cap√≠tulo 2 deste trabalho, foi feita uma revis√£o da literatura dispon√≠vel, publicada nos √ļltimos cinco anos, referindo os n√≠veis de antidepressivos e seus metabolitos no ambiente aqu√°tico e, tamb√©m, os efeitos reportados em peixes e invertebrados. De uma maneira geral, os estudos laboratoriais dispon√≠veis mostraram que os antidepressivos podem alterar v√°rios processos biol√≥gicos nos organismos aqu√°ticos, tendo um efeito prejudicial. O presente trabalho tem como objetivo avaliar os efeitos agudos (0.1 a 3000 ¬Ķg.L-1 ) e cr√≥nicos (2 a 1000√ó103 ng.L-1 ) da SER no peixe-zebra (Danio rerio) avaliando-se diferentes par√Ęmetros, tais como desenvolvimento (como por exemplo, mortalidade, movimentos espont√Ęneos, equil√≠brio, anormalidades e batimento card√≠aco), biomarcadores bioqu√≠micos associados √† neurotransmiss√£o (acetilcolinesterase (AChE)), defesas antioxidantes (catalase (CAT) e glutationa S-transferases (GSTs)), metabolismo energ√©tico (lactato desidrogenase (LDH)) e comportamento (resposta a est√≠mulos de luz/escuro). Os embri√Ķes de peixezebra demonstraram sensibilidade √†s concentra√ß√Ķes de SER durante o desenvolvimento (por exemplo, diminui√ß√£o dos movimentos espont√Ęneos e aumento/diminui√ß√£o dos batimentos card√≠acos, dependendo da concentra√ß√£o exposta). Relativamente aos biomarcadores bioqu√≠micos avaliados, na exposi√ß√£o aguda a atividade enzim√°tica das GSTs aumentou significativamente e, tanto na exposi√ß√£o aguda como na exposi√ß√£o cr√≥nica, houve um aumento significativo da atividade enzim√°tica da LDH. As respostas aos est√≠mulos de luz/escuro estavam geralmente diminu√≠das na exposi√ß√£o aguda, enquanto na exposi√ß√£o cr√≥nica as respostas estavam elevadas. Estes resultados apoiam a necessidade de se realizarem mais estudos acerca dos efeitos dos antidepressivos a longo prazo, tais como a SER, na biota aqu√°tica e o desenvolvimento de novas tecnologias para os remover eficientemente do ambiente.Mestrado em Bioqu√≠mic

    Environmental surveillance for Salmonella Typhi as a tool to estimate the incidence of typhoid fever in low-income populations.

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    Background: The World Health Organisation recommends prioritised use of recently prequalified typhoid conjugate vaccines in countries with the highest incidence of typhoid fever. However, representative typhoid surveillance data are lacking in many low-income countries because of the costs and challenges of diagnostic clinical microbiology. Environmental surveillance (ES) of Salmonella Typhi in sewage and wastewater using molecular methods may offer a low-cost alternative, but its performance in comparison with clinical surveillance has not been assessed. Methods: We developed a harmonised protocol for typhoid ES and its implementation in communities in India and Malawi where it will be compared with findings from hospital-based surveillance for typhoid fever. The protocol includes methods for ES site selection based on geospatial analysis, grab and trap sample collection at sewage and wastewater sites, and laboratory methods for sample processing, concentration and quantitative polymerase chain reaction (PCR) to detect Salmonella Typhi. The optimal locations for ES sites based on digital elevation models and mapping of sewage and river networks are described for each community and their suitability confirmed through field investigation. We will compare the prevalence and abundance of Salmonella Typhi in ES samples collected each month over a 12-month period to the incidence of blood culture confirmed typhoid cases recorded at referral hospitals serving the study areas. Conclusions: If environmental detection of Salmonella Typhi correlates with the incidence of typhoid fever estimated through clinical surveillance, typhoid ES may be a powerful and low-cost tool to estimate the local burden of typhoid fever and support the introduction of typhoid conjugate vaccines. Typhoid ES could also allow the impact of vaccination to be assessed and rapidly identify circulation of drug resistant strains

    Ecological successions throughout the desiccation of Tirez lagoon (Spain) as an astrobiological time-analog for wet-to-dry transitions on Mars

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    Tirez was a small and seasonal endorheic athalassohaline lagoon that was located in central Spain. In recent years, the lagoon has totally dried out, offering for the first time the opportunity to analyze its desiccation process as a ‚Äútime-analog‚ÄĚ to similar events occurred in paleolakes with varying salinity during the wet-to-dry transition on early Mars. On the martian cratered highlands, an early period of water ponding within enclosed basins evolved to a complete desiccation of the lakes, leading to deposition of evaporitic sequences during the Noachian and into the Late Hesperian. As Tirez also underwent a process of desiccation, here we describe (i) the microbial ecology of Tirez when the lagoon was still active 20 years ago, with prokaryotes adapted to extreme saline conditions; (ii) the composition of the microbial community in the dried lake sediments today, in many case groups that thrive in sediments of extreme environments; and (iii) the molecular and isotopic analysis of the lipid biomarkers that can be recovered from the sediments today. We discuss the implications of these results to better understanding the ecology of possible Martian microbial communities during the wet-to-dry transition at the end of the Hesperian, and how they may inform about research strategies to search for possible biomarkers in Mars after all the water was los

    Effects of combined interventions to optimize recovery during high-intensity exercises in trained individuals

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    Background Team sports such as ice hockey offer the opportunity of recovery breaks between high-intensity work intervals. Strategies aiming to mitigate fatigue during intermittent physical activity are seldom investigated in combination, although several different mechanisms of action exist, which might be cumulative and therefore beneficial for athletes. This study examined the effects of seven combined recovery interventions (enhanced recovery package, ERP) on exercise capacity during intermittent high-intensity cycling. Methods Sixteen trained men (age: 24.8 ¬Ī 3.4 y; maximal power output: 5.0 ¬Ī 0.5 WÔĹ•kg-1) completed a repeated sprint exercise (RSE) protocol consisting of six 30-s cycling sprints with 3-min breaks between each sprint. The first sprint was always performed at a similar load, while sprints 2-6 were performed with the ergometer in cadence dependent mode (0.075 kgÔĹ•kg-1). During the breaks, the ERP, Placebo, or Control protocols were applied, all on different days. The ERP condition combined 1) 3-min ice gel packs to the neck; 2, 3) 5-s mouth rinsing of a 10% carbohydrate and caffeine (6 mgÔĹ•kg-1), 4) ingestion of 50 ml of a 6% carbohydrate solution, 5, 6) 30 s of all-out hyperventilation while breathing 100% O2 (hyperoxia); and finally, 7) potentiation maneuvers via performance of 3 half-squats at 75% of one maximal repetition. The placebo intervention masked the interventions except for the ice packs and potentiation maneuvers. Participants were told they were performing a simplified version with only the known beneficial interventions. Power output, heart rate, blood lactate concentration, rate of perceived exertion and gas exchange were compared between the ERP and Placebo conditions. Results Mean power output (W) was significantly higher for the ERP condition compared to Placebo (570 ¬Ī 74 W vs. 560 ¬Ī 71 W, t(15) = 4.603, P < 0.001, 95% CI diff = 5 ‚Äď 14 W, dz = 1.15). The rate of power decrement over sprints 2-6 was very similar between trials (ERP -14.2 W per sprint, 95% CI = -21.6 ‚Äď -6.8 W; Placebo -17.4 W per sprint, 95% CI = -24.7 ‚Äď -10.2 W per sprint, P = 0.407). Mean heart rate was higher (3 ¬Ī 4 bpm, P = 0.012) for the ERP compared to the Placebo condition, as was breathing frequency (2.4 ¬Ī 4.0 breathsÔĹ•min-1, P = 0.028) and respiratory exchange ratio (0.12 ¬Ī 0.06, P < 0.001). Oxygen uptake was 80 ¬Ī 109 mlÔĹ•min-1 (P = 0.013) lower for ERP. No differences were found with regards to the rate of perceived exertion or blood lactate concentration. Conclusion ERP optimized recovery when applied during the breaks of a high-intensity repeated sprint exercise and shows a small but consistent increase in mean power output. It is possible that the ERP prevented a loss of aerobic efficiency. A top-down approach when tailoring packages for individual athletes might overcome the issue of small improvements that are difficult to detect when strategies are tested in isolation

    The influence of different enzymatic preparations and skin contact time on aromatic profile of wines produced from autochthonous grape varieties Krstańć and ŇĹiŇĺak: Scientific paper

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    This study aimed to show aromatic profile of wines produced from two autochthonous grape cultivars Krstańć (K) and ŇĹiŇĺak (Z). During the wine production two enzymatic preparations (EP) Lallzyme cuvee blanc (CB) and Lallzyme enzymatic preparation ő≤ (EB) and different time of skin contact (4 and 8 h) were applied. Aromatic compounds were detected by GC/FID‚ÄďMS ana¬≠lysis. Significantly higher content of total detected aromatic compounds com¬≠pared to appropriate controls (168.54 and 161.72 mg L-1) was observed for K EB4h (176.33 mg L-1) and Z CB4h (177.29 mg L-1) wines. Skin contact and usage of EP mostly increased content of 2-phenylethyl and isoamyl alcohols. Wines from both varieties showed higher content of hexanoic and octanoic acids compared to the control. It is interesting to emphasize that content of esters that are responsible for fruity aroma of wine which is important for plea¬≠sant taste (isoamyl acetate ‚Äď banana, ethyl hexanoate ‚Äď ripe banana, 2-phe¬≠nyl¬≠ethyl acetate ‚Äď powerful fruity rose like) were increased in all samples com¬≠pared to the controls. The highest grades, after sensory evaluation, were obtained for K EB 8h (18.0 out of 20.0) and Z CB 8h (18.2 out of 20.0)

    EFFECTIVENESS OF OVINE FOLLICULAR FLUID AND EWE AGE ON IN VITRO NUCLEAR MATURATION AND EMBRYO EVOLUTION OF AWASSI EWES

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    Two experiments were conducted to study the efficiency of the ovine follicular fluid (OFF) and the age of ewe on in vitro nuclear maturation of Awassi sheep oocytes (Experiment 1) and the subsequent stages of early embryos and their quality (Experiment 2). The OFF has been added to the basic maturation medium (TCM-199) with three different levels (A: 0% (Control group), B:15%, C:25% and D:50%) while the ages of the ewes were determined into two main groups (> 2 and 1-2 year). In the first experiment, across the two age groups, matured oocytes in C solution achieved the highest (p=0.006) rates of metaphase-II (85.70 and 82.35 % respectively). In the second experiment, oocytes belonging to > 2 and 1-2-year ewe age groups (C Solution) achieved the highest (p=0.001) rates  of fertilization (23.17 and 30.73% respectively). Similar trend applies to the cleavage stage, the rates reached 35.14 and 41.27% respectively (p=0.01). No significant differences were noticed at the different stages of cleavage (2-4 cell, morula, and blastocyst). The resulting embryos of B (> 2-year ewe age group) and C solution (1-2-year age group) achieved the highest (p=0.04) rates of Type1 embryos (69.56 and 76.92% respectively). A significant difference was noticed in type2 embryos (p=0.02), embryos of the first and second age groups (Solution D) achieved the highest rates (46.15 and 33.33% respectively). It can be concluded that the adding of 25% OFF to the maturation media led to significant improvement in the rates of maturation, cleavage and type1 embryos of sheep oocytes

    Alterations to cerebral perfusion, metabolite profiles, and neuronal morphology in the hippocampus and cortex of male and female mice during chronic exposure to a high-salt diet

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    Excess dietary salt reduces resting cerebral blood flow (CBF) and vascular reactivity, which can limit the fueling of neuronal metabolism. It is hitherto unknown whether metabolic derangements induced by high-salt-diet (HSD) exposure during adulthood are reversed by reducing salt intake. In this study, male and female mice were fed an HSD from 9 to 16 months of age, followed by a normal-salt diet (ND) thereafter until 23 months of age. Controls were continuously fed either ND or HSD. CBF and metabolite profiles were determined longitudinally by arterial spin labeling magnetic resonance imaging and magnetic resonance spectroscopy, respectively. HSD reduced cortical and hippocampal CBF, which recovered after dietary salt normalization, and affected hippocampal but not cortical metabolite profiles. Compared to ND, HSD increased hippocampal glutamine and phosphocreatine levels and decreased creatine and choline levels. Dietary reversal only allowed recovery of glutamine levels. Histology analyses revealed that HSD reduced the dendritic arborization and spine density of cortical and hippocampal neurons, which were not recovered after dietary salt normalization. We conclude that sustained HSD exposure throughout adulthood causes permanent structural and metabolic alterations to the mouse brain that are not fully normalized by lowering dietary salt during aging

    Biochemical characterization and identification of ferulenol and embelin as potent inhibitors of malate:quinone oxidoreductase from Campylobacter jejuni

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    Campylobacter jejuni infection poses a serious global threat to public health. The increasing incidence and antibiotic resistance of this bacterial infection have necessitated the adoption of various strategies to curb this trend, primarily through developing new drugs with new mechanisms of action. The enzyme malate:quinone oxidoreductase (MQO) has been shown to be essential for the survival of several bacteria and parasites. MQO is a peripheral membrane protein that catalyses the oxidation of malate to oxaloacetate, a crucial step in the tricarboxylic acid cycle. In addition, MQO is involved in the reduction of the quinone pool in the electron transport chain and thus contributes to cellular bioenergetics. The enzyme is an attractive drug target as it is not conserved in mammals. As a preliminary step in assessing the potential application of MQO from C. jejuni (CjMQO) as a new drug target, we purified active recombinant CjMQO and conducted, for the first time, biochemical analyses of MQO from a pathogenic bacterium. Our study showed that ferulenol, a submicromolar mitochondrial MQO inhibitor, and embelin are nanomolar inhibitors of CjMQO. We showed that both inhibitors are mixed-type inhibitors versus malate and noncompetitive versus quinone, suggesting the existence of a third binding site to accommodate these inhibitors; indeed, such a trait appears to be conserved between mitochondrial and bacterial MQOs. Interestingly, ferulenol and embelin also inhibit the in vitro growth of C. jejuni, supporting the hypothesis that MQO is essential for C. jejuni survival and is therefore an important drug target
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