Ecotoxicological endpoints, are they useful tools to support ecological status assessment in strongly modified water bodies?

Although man-made reservoirs represent an important water supply source in countries where water scarcity has become a problem, little work has been done on the evaluation of their ecological status. Taking this in account, the general aim of this study was to assess the usefulness of ecotoxicological endpoints in the potential ecological status characterization of water reservoirs, with the purpose of their possible integration in evaluation programs developed under the Water Framework Directive (WFD). To achieve this purpose, a group of bioassays were selected to evaluate both water and sediment compartments at the Alqueva reservoir (the biggest from the Iberian Peninsula), with representative species from different taxonomic and functional groups: Vibrio fischeri, Thamnocephalus platyurus, Daphnia magna and Heterocypris incongruens. The ecotoxicological assessment showed that sublethal endpoints (e.g., luminescence, growth or reproduction), would be more useful and sensitive to identify toxicity patterns in this type of water body. In general, the results from this ecotoxicological toolbox agreed with the potential ecological status established according to the WFD, which indicates that the bioassays complement the ecological assessment. Furthermore, the use of an ecotoxicological approach can be extremely useful, especially in cases where the biotic indices are difficult to establish, such as in man-made reservoirs. However, when pollutant concentrations are very low, and/or when nutrients and organic matter concentrations are high, the two approaches do not fit, requiring further research to determine which organisms are more sensitive and the best biotic indices to use under those conditions.

Occurrence and potential risk of currently used pesticides in sediments of the Alqueva reservoir (Guadiana Basin).

The evaluation of sediments, concerning to pesticides, constitutes an important step for the understanding of the principal sources of contamination of the surface water. Hence, the purpose of this study was to evaluate for the first time the occurrence, distribution and risk of pesticides in sediments of the Alqueva reservoir, the largest reservoir in the Europe. For this purpose, the occurrence of 22 pesticides and some of their degradation products was determined in surficial sediments of the Alqueva reservoir. To assess the potential risk on ecosystem, the measured concentrations of pesticides were compared with regulatory and toxicological benchmarks. Of the 22 pesticides analysed, only 8 were detected. Diuron was the pesticide detected in greater concentration, followed by terbuthylazine and chlortoluron. The sediments most polluted by pesticides were from Lucefécit, constituted totally by fine particles (<0.063 mm) and with high values of organic matter, and are located nearby large agricultural fields. The risk assessment allowed us to conclude that the sediments from the Alqueva reservoir presented low risk, concerning to pesticides, for the various communities that integrate the aquatic ecosystems. However, some of the compounds detected present a high potential for bioaccumulation that may lead to their bioamplification in the trophic chain, reaching concentrations higher than their acceptable daily intake, putting, in this way the populations at risk.

Lysosomal membrane permeabilization and autophagy blockade contribute to photoreceptor cell death in a mouse model of retinitis pigmentosa.

Retinitis pigmentosa is a group of hereditary retinal dystrophies that normally result in photoreceptor cell death and vision loss both in animal models and in affected patients. The rd10 mouse, which carries a missense mutation in the Pde6b gene, has been used to characterize the underlying pathophysiology and develop therapies for this devastating and incurable disease. Here we show that increased photoreceptor cell death in the rd10 mouse retina is associated with calcium overload and calpain activation, both of which are observed before the appearance of signs of cell degeneration. These changes are accompanied by an increase in the activity of the lysosomal protease cathepsin B in the cytoplasm of photoreceptor cells, and a reduced colocalization of cathepsin B with lysosomal markers, suggesting that lysosomal membrane permeabilization occurs before the peak of cell death. Moreover, expression of the autophagosomal marker LC3-II (lipidated form of LC3) is reduced and autophagy flux is blocked in rd10 retinas before the onset of photoreceptor cell death. Interestingly, we found that cell death is increased by the induction of autophagy with rapamycin and inhibited by calpain and cathepsin inhibitors, both ex vivo and in vivo. Taken together, these data suggest that calpain-mediated lysosomal membrane permeabilization underlies the lysosomal dysfunction and downregulation of autophagy associated with photoreceptor cell death.

Risk assessment of pesticides detected in surface water of the Alqueva reservoir (Guadiana basin, southern of Portugal).

The purpose of this study was to evaluate the potential impact of the pesticides detected in the Alqueva reservoir (Guadiana Basin, South Iberian Peninsula) on the aquatic organisms belonging to this ecosystem. For this purpose, the occurrence and risk assessment of 25 pesticides and of a number of their degradation products were determined in the Alqueva surface waters. The areas (sampling stations) most polluted by pesticides were Sra. Ajuda, Lucefecit and Álamos in the northern and in the middle portions of the reservoir, respectively. The aquatic risk assessment revealed that from the various compounds analysed terbuthylazine, chlorfenvinphos and diazinon presented non-acceptable risk when maximum concentrations were used as the measured environmental concentrations (MEC). The locations that had more samples with risk quotients higher than 1 (high risk) were Sra. Ajuda followed by Lucefécit. The use of risk assessment allowed us to conclude that, despite that the pesticides' concentrations in the water column fulfil the European environmental quality standards, a number of the compounds show a high ecotoxicological risk for the aquatic organisms in the Alqueva ecosystem. The results thereby demonstrate that to have an efficient risk management process, the regulatory authorities of each country must consider an integrative chemical and ecotoxicological approach.

Spatial and temporal variability of the water and sediments quality in the Alqueva reservoir (Guadiana Basin; southern Portugal).

The purpose of this work was to evaluate the dynamic of the water quality from the Alqueva reservoir (Guadiana River Basin, Portugal) and identify the most important parameters that influence its ecological and chemical status. The results could indicate preventive and/or remediation actions that are necessary to improve its quality and status. Water and sediment samples were collected between 2011 and 2012, at five sampling stations, and analyzed for: (i) water - pH, temperature, dissolved oxygen, electrical conductivity, chloride, total phosphorus, total nitrogen, ammonium, nitrate, nitrite, biochemical and chemical oxygen demand, total Fe, Mn, and As; and (ii) sediments - pH, electrical conductivity, organic matter, total nitrogen, total phosphorus, major and trace elements. The results from the water column showed that the organic descriptors exceeded the Portuguese guideline values for water quality for multiple uses at most of the sampling stations. As for nutrients, Ajuda is the station where the concentrations of the total nitrogen and total phosphorus exceeded the guideline values in most months. Ammonium achieved concentrations above the allowed, during the study, in all locations. Trace elements were more abundant in the sediments, surpassing the maximum levels for the protection of aquatic life for As, Cd and Pb, at Alcarrache, Lucefécit and Álamos, respectively. The use of multivariate analysis showed that the major parameters that explained the water quality variability were the nutrients in the water column, and trace elements in the sediments. Comparing the results from this study with results obtained since 2006, we can observe an obvious increment of the organic descriptors and nutrients in the water body. Further, several parameters and observations indicate an increase of the eutrophication process. So, it is urgent to develop preventive actions and remediation processes to stop the degradation so as to improve the quality of the water in this reservoir.

Integrated environmental assessment of freshwater sediments: a chemical and ecotoxicological approach at the Alqueva reservoir.

In order to study the pollution of an aquatic ecosystem, it is necessary to analyze not only the levels of chemical pollutants in water, but also those accumulated in the sediment matrix, as well as to assess its ecotoxicological status. The Alqueva reservoir, the largest artificial lake in Europe, was chosen as case study as it constitutes the most important water supply source in southern Portugal. It is located in the Guadiana River Basin, in a semi-arid region with high levels of water scarcity and where agriculture is one of the main activities. The evaluation of sediments comprised: (1) physical and chemical analysis (grain size, pH, organic matter, nitrogen, phosphorus); (2) potentially toxic trace elements (Cu, As, Pb, Cr, Cd, Zn and Ni); and (3) ecotoxicological evaluation with Vibrio fischeri, Thamnocephalus platyurus, Daphnia magna, and Heterocypris incongruens. Total trace element concentrations indicated that As, Cd, and Pb surpassed the Canadian levels for the protection of aquatic life, in most of Alqueva's sites. The results of the toxicity assessment showed that some locations induced acute and chronic toxicity in the species used. Further, the H. incongruens was the most sensitive species as far as the contamination found in the sediment is concerned, followed by the bacteria V. fischeri. This integrative approach, together with the water column quality assessment, allowed a comprehensive evaluation of the environmental quality of this strongly modified water body and will allow the implementation of remediation strategies to obtain a good ecological potential as proposed in the Water Framework Directive.

[Clinical aspects and endoscopic management of gastrointestinal bleeding from Dieulafoy's lesion]. / Aspectos clínicos y tratamiento endoscópico de la hemorragia digestiva por lesión de Dieulafoy.

OBJECTIVE: the aim of the study was to assess the incidence, clinical presentation, location, and response to endoscopic therapy of gastrointestinal bleeding from Dieulafoy's lesion. MATERIAL AND METHOD: ALL consecutive episodes of gastrointestinal bleeding due to Dieulafoy's lesion seen between 2000 and 2006 were retrospectively reviewed. All main clinical and endoscopic data were collected: type and effectiveness of endoscopic therapy, rebleeding, complications, and mortality during hospitalization. RESULTS: WE found 41 patients, 26 males and 15 females, median age of 71.19 years. Dieulafoy's lesion accounted for 1.55% of all gastrointestinal bleeding episodes during the study period. The incidence of Dieulafoy's lesion was 2.2 cases/100.000 inhabitants/year. Active bleeding at endoscopy was present in 85.36%, and comorbidity in 92.68%. The stomach was the most frequent location (60.97%), followed by duodenum (29.26%). Endoscopic therapy achieved initial hemostasis in all cases. Three patients (7.31%) initially treated with epinephrine injection showed rebleeding and properly responded to a second session of endoscopic therapy. No surgery was needed. The mortality rate during hospitalization was 4.87%. CONCLUSIONS: Dieulafoy's lesion is an uncommon, but potentially severe cause of gastrointestinal bleeding. It may be found in any location within the gastrointestinal tract. Endoscopic therapy is effective and safe. Injected epinephrine alone is associated with a higher risk of rebleeding.

Aspectos clínicos y tratamiento endoscópico de la hemorragia digestiva por lesión de Dieulafoy / Clinical aspects and endoscopic management of gastrointestinal bleeding from Dieulafoy's lesion

Objetivo: conocer la incidencia, forma de presentación, localizacióny resultados del tratamiento endoscópico en la hemorragiadigestiva causada por lesión de Dieulafoy.Material y métodos: se revisaron de forma retrospectiva todoslos casos de hemorragia digestiva por lesión de Dieulafoy entrelos años 2000 y 2006. Se recogieron los principales datos clínicosy endoscópicos, tipo de tratamiento empleado, eficacia delmismo, recidiva, complicaciones y mortalidad durante el ingreso.Resultados: se encontraron 41 pacientes, 26 varones y 15mujeres, con edad media de 71,19 años. La lesión de Dieulafoyfue la causa del 1,55% de los casos de hemorragia digestiva agudaen el periodo estudiado. La incidencia de hemorragia digestivapor lesión de Dieulafoy fue de 2,2 casos por cada 100.000 habitantesy año. La mayoría de los pacientes presentaban hemorragiaactiva en el momento de la endoscopia (85,36%) y comorbilidad(92,68%). La localización más frecuente fue el estómago(60,97%), seguida del duodeno (29,26%). El tratamiento endoscópicologró la hemostasia inicial en el 100% de los casos. Trespacientes (7,31%) presentaron recidiva hemorrágica, todos elloshabían sido tratados inicialmente con esclerosis con adrenalina yrespondieron adecuadamente a un segundo tratamiento endoscópico.Ningún paciente precisó cirugía. La mortalidad durante elingreso fue del 4,87%.Conclusiones: la lesión de Dieulafoy es una causa poco frecuente,pero potencialmente grave, de hemorragia digestiva ypuede aparecer en cualquier punto del tracto gastrointestinal. Eltratamiento endoscópico es eficaz y presenta pocas complicaciones.La esclerosis única con adrenalina se asocia a un mayor riesgode recidiva hemorrágica

Objective: the aim of the study was to assess the incidence,clinical presentation, location, and response to endoscopic therapyof gastrointestinal bleeding from Dieulafoy’s lesion.Material and methods: all consecutive episodes of gastrointestinalbleeding due to Dieulafoy’s lesion seen between 2000 and2006 were retrospectively reviewed. All main clinical and endoscopicdata were collected: type and efectiveness of endoscopictherapy, rebleeding, complications, and mortality during hospitalization.Results: we found 41 patients, 26 males and 15 females, medianage of 71.19 years. Dieulafoy’s lesion accounted for 1.55%of all gastrointestinal bleeding episodes during the study period.The incidence of Dieulafoy’s lesion was 2.2 cases/100.000 inhabitants/year. Active bleeding at endoscopy was present in85.36%, and comorbidity in 92.68%. The stomach was the mostfrequent location (60.97%), followed by duodenum (29.26%). Endoscopictherapy achieved initial hemostasis in all cases. Threepatients (7.31%) initially treated with epinephrine injectionshowed rebleeding and properly responded to a second session ofendoscopic therapy. No surgery was needed. The mortality rateduring hospitalization was 4.87%.Conclusions: Dieulafoy’s lesion is an uncommon, but potentiallysevere cause of gastrointestinal bleeding. It may be found inany location within the gastrointestinal tract. Endoscopic therapyis effective and safe. Injected epinephrine alone is associated witha higher risk of rebleeding

[Droxicam-induced hepatitis. Description of 3 new cases and review of the literature]. / Hepatitis por droxicam. Descripción de tres nuevos casos y revisión de la literatura.

Three new cases of cholestatic hepatitis caused by droxicam are described, along with a revision of the other eight cases published to date. Itching, asthenia, and jaundice were the most common symptoms. Average age was 62.8 years (range: 45-82 years), and the median time of exposition was 22.7 days (range: 5-50 days). Biochemistry of the liver showed primarily cholestasis and in 4/11 cases hypereosinophilia. Two patients presented elevated levels of cholesterol and triglycerides which disappeared within the month. Clinical manifestations persisted in one patient for eight weeks after the cessation of treatment. The three patients presented in the present series presented alteration in the biochemistry of the liver two months after initiation. Liver biopsy in three patients showed centrozonal cholestasis associated with portal inflammatory activity and presence of granulomas consistent with toxic hepatitis.

Ascites adenosine deaminase activity is decreased in tuberculous ascites with low protein content.

The value of adenosine deaminase activity (ADA) in ascitic fluid was examined in 12 patients with confirmed peritoneal tuberculosis and compared with that of 96 patients with ascites of other different etiologies as an age-matched control group, to determine the diagnostic value of the ADA activity in tuberculous ascites. The mean adenosine deaminase activity (ADA) value in ascitic fluid of the tuberculous peritonitis group was 47.9 +/- 21.9 IU/L and in the control group 9.6 +/- 5 U/L (mean +/- SD); p less than 0.01. A different method than that usually reported in tuberculous peritonitis was used for ascites ADA estimation. The best sensitivity and specificity was obtained when greater than 32 U/L was used as a cutoff point. The ascites ADA activity correlated with the ascites total protein concentration in the tuberculosis group (r = 0.842). Our findings confirm other results and support the ADA activity determination in ascitic fluid as a useful noninvasive screening test in the diagnosis of peritoneal tuberculosis in endemic areas or in high risk patients. However, false-negative results may occur in those patients in which ascites total protein concentration is low.