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1.
Ecotoxicol Environ Saf ; 145: 420-430, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28772230

RESUMEN

Cyanobacterial blooms and cyanotoxins occur in freshwater lakes and reservoirs all over the world. Bacterial degradation of microcystins (MC), hepatotoxins produced by several cyanobacterial species, has also been broadly documented. However, information regarding MC biodegradation in European water bodies is very limited. In this paper, the occurrence and identification of MC biodegradation products was documented for 21 European lakes and reservoirs, many of which have well-documented cyanobacterial bloom histories. Varying cyanobacterial abundance and taxonomical composition were documented and MC producers were found in all the analysed samples. Planktothrix agardhii was the most common cyanobacterial species and it formed mass occurrences in four lakes. MC biodegradation was observed in 86% of the samples (18 out of 21), and four products of dmMC-LR decomposition were detected by HPLC and LC-MS methods. The two main products were cyclic dmMC-LR with modifications in the Arg-Asp-Leu region; additionally one product was recognized as the tetrapeptide Adda-Glu-Mdha-Ala. The composition of the detected products suggested a new biochemical pathway of MC degradation. The results confirmed the hypothesis that microcystin biodegradation is a common phenomenon in central European waters and that it may occur by a mechanism which is different from the one previously reported. Such a finding implies the necessity to develop a more accurate methodology for screening bacteria with MC biodegradation ability. Furthermore, it warrants new basic and applied studies on the characterization and utilization of new MC-degrading strains and biodegradation pathways.


Asunto(s)
Cianobacterias/aislamiento & purificación , Monitoreo del Ambiente/métodos , Agua Dulce/química , Microcistinas/análisis , Contaminantes Químicos del Agua/análisis , Biodegradación Ambiental , Cromatografía Líquida de Alta Presión , Eutrofización , Agua Dulce/microbiología , Espectrometría de Masas , Polonia
2.
Chemosphere ; 363: 142815, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38986786

RESUMEN

Continuous nitrate treatment is an innovative, nature-based and cost-effective restoration method that has been implemented in a small, hypereutrophic lake by redirecting the nitrate-rich waters of the lake's natural tributaries into its hypolimnion. The aim of this treatment is to increase the redox potential at the sediment-water interface in order to provide conditions for efficient phosphorus binding. To assess the effects of this treatment, studies of the physico-chemical and biological parameters of the lake waters were carried out before its application (PreNT - years 2005-2007), during its application (FullNT - 2008-July 2019), and in the period when installation was partly clogged (LimNT- August 2019-2021). The results show effective improvement of oxygenation of the hypolimnion during the treatment followed by a decrease of phosphorus concentration - a proxy of the reduced internal loading. Water quality gradually improved during the treatment. The periods of cyanobacterial blooms shortened in some years, and ceased in other years, and it was also manifested by the increase in the range of Secchi depth and a decrease in chlorophyll-a concentration. The share of eukaryotic algae in the phytoplankton increased. The method showed high resistance to disturbances in its functioning, because during two years of operation of one pipeline, only a slight deterioration of water quality was observed. This enables effective repair of the hypolimnion's supply of nitrates, without a sudden return to the pre-restoration state. Finally, the benefits and limitations of hypolimnetic nitrate treatment (with nitrate from natural sources) were discussed to facilitate the application of this method to other lakes.


Asunto(s)
Lagos , Nitratos , Fósforo , Lagos/química , Nitratos/análisis , Fósforo/análisis , Calidad del Agua , Contaminantes Químicos del Agua/análisis , Fitoplancton/efectos de los fármacos , Cianobacterias , Eutrofización , Clorofila A
3.
Environ Sci Pollut Res Int ; 25(15): 15245-15252, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29680888

RESUMEN

The occurrence of cyanobacteria in freshwaters attracts much attention due to its associated health threats and ecological implications. Yet data on the composition of cyanobacteria taxa and toxigenicity in some regions is still scarce. Here, we explored the occurrence of cyanobacteria and cyanotoxins in three locations in Ukraine (reservoir for Kasperivtsi Hydrothermal Power Plant and outflowing River Seret, and cooling pond of Khmelnytsky Atomic Power Plant) in summer 2017. Cyanobacteria were a dominant fraction at all stations. A number of potent-toxin producers were identified including Cylindrospermopsis raciborskii, Aphanizomenon gracile, Dolichospermum flos-aquae, and Planktothrix agardhii. Screening for the presence of dissolved and particulate content of microcystins (-LR, -YR, and -RR), cylindrospermopsin, and anatoxin-a yielded negative results. The studied waters displayed no toxicity in human platelets in vitro. Further toxicological and ecological studies are necessary to evaluate the potential presence of cyanotoxin producers in Ukraine.


Asunto(s)
Cianobacterias/aislamiento & purificación , Cylindrospermopsis/aislamiento & purificación , Monitoreo del Ambiente/métodos , Agua Dulce/microbiología , Centrales Eléctricas , Plaquetas/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Agua Dulce/química , Ríos/química , Ríos/microbiología , Estaciones del Año , Ucrania , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
4.
Toxins (Basel) ; 10(4)2018 04 13.
Artículo en Inglés | MEDLINE | ID: mdl-29652856

RESUMEN

Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.


Asunto(s)
Toxinas Bacterianas/análisis , Cianobacterias , Lagos/microbiología , Microcistinas/análisis , Tropanos/análisis , Uracilo/análogos & derivados , Contaminantes del Agua/análisis , Alcaloides , Cambio Climático , Toxinas de Cianobacterias , Monitoreo del Ambiente , Europa (Continente) , Temperatura , Uracilo/análisis
5.
Eur J Gastroenterol Hepatol ; 28(10): 1223-8, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27455079

RESUMEN

INTRODUCTION: Most patients with malignant biliary obstruction are suited only for palliation by endoscopic drainage with plastic stents (PS) or self-expandable metal stents (SEMS). OBJECTIVE: To compare the clinical outcome and costs of biliary stenting with SEMS and PS in patients with malignant biliary strictures. PATIENTS AND METHODS: A total of 114 patients with malignant jaundice who underwent 376 endoscopic retrograde biliary drainage (ERBD) were studied. RESULTS: ERBD with the placement of PS was performed in 80 patients, with one-step SEMS in 20 patients and two-step SEMS in 14 patients. Significantly fewer ERBD interventions were performed in patients with one-step SEMS than PS or the two-step SEMS technique (2.0±1.12 vs. 3.1±1.7 or 5.7±2.1, respectively, P<0.0001). The median hospitalization duration per procedure was similar for the three groups of patients. The patients' survival time was the longest in the two-step SEMS group in comparison with the one-step SEMS and PS groups (596±270 vs. 276±141 or 208±219 days, P<0.001). Overall median time to recurrent biliary obstruction was 89.3±159 days for PS and 120.6±101 days for SEMS (P=0.01). The total cost of hospitalization with ERBD was higher for two-step SEMS than for one-step SEMS or PS (1448±312, 1152±135 and 977±156&OV0556;, P<0.0001). However, the estimated annual cost of medical care for one-step SEMS was higher than that for the two-step SEMS or PS groups (4618, 4079, and 3995&OV0556;, respectively). CONCLUSION: Biliary decompression by SEMS is associated with longer patency and reduced number of auxiliary procedures; however, repeated PS insertions still remain the most cost-effective strategy.


Asunto(s)
Colangiopancreatografia Retrógrada Endoscópica/economía , Colangiopancreatografia Retrógrada Endoscópica/instrumentación , Colestasis/economía , Colestasis/terapia , Descompresión Quirúrgica/economía , Descompresión Quirúrgica/instrumentación , Drenaje/economía , Drenaje/instrumentación , Costos de Hospital , Metales/economía , Plásticos/economía , Stents/economía , Adulto , Anciano , Anciano de 80 o más Años , Colangiopancreatografia Retrógrada Endoscópica/efectos adversos , Colangiopancreatografia Retrógrada Endoscópica/mortalidad , Colestasis/diagnóstico por imagen , Colestasis/mortalidad , Constricción Patológica , Ahorro de Costo , Análisis Costo-Beneficio , Descompresión Quirúrgica/efectos adversos , Descompresión Quirúrgica/mortalidad , Drenaje/efectos adversos , Drenaje/mortalidad , Femenino , Humanos , Tiempo de Internación/economía , Masculino , Persona de Mediana Edad , Polonia , Diseño de Prótesis , Recurrencia , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento
6.
Int J Antimicrob Agents ; 26(3): 230-4, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16122912

RESUMEN

The resistance of Helicobacter pylori to antimicrobials, known to be increasing in many countries, is an important factor compromising the efficacy of eradication therapy. Therefore, our study aimed at analysing the current susceptibility status of H. pylori in Poland. A total of 337 H. pylori isolates were cultured from children (N=179) and adults (N=158) from various regions of the country from January 2001 to December 2004. All strains were susceptible to amoxicillin and tetracycline. The overall resistance to clarithromycin (CL) was 28%, but there were significant differences between the centres (ranging from 0% to 33%) and between child and adult isolates (28% versus 15%, respectively; P=0.01) for primary a resistance. Altogether, 46% of H. pylori isolates were resistant to metronidazole (MTZ) and 20% of isolates were simultaneously resistant to CL and MTZ.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Infecciones por Helicobacter/microbiología , Helicobacter pylori/efectos de los fármacos , Adulto , Amoxicilina/farmacología , Niño , Claritromicina/farmacología , Helicobacter pylori/aislamiento & purificación , Humanos , Metronidazol/farmacología , Pruebas de Sensibilidad Microbiana , Polonia , Tetraciclina/farmacología
7.
Prz Gastroenterol ; 10(1): 47-50, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25960815

RESUMEN

We present a 22-year-old male who developed a severe erosive oesophagitis extending to the pharynx and oral cavity without obvious risk factors. Endoscopic image suggested viral aetiology that could not be confirmed by routine serological diagnostics of infections with cytomegalovirus, Epstein-Barr virus, and Herpes simplex virus. The histopathological evaluation also gave no definite clues to the aetiology of the inflammation. Treatment with acyclovir was ineffective, but gancyclovir therapy caused spectacular clinical improvement and healing of erosions. Two months later the patient presented febrile diarrhoea that was a symptom of ileocecal Crohn's disease proven by endoscopy, enterography, and histopathology. It is the first report of severe viral oesophagitis preceding clinical manifestation of Crohn's disease. This observation warrants further study towards the viral aetiology of oral, pharyngeal, and oesophageal erosions, frequently associated with Crohn's disease.

8.
World J Gastroenterol ; 20(14): 4102-5, 2014 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-24744602

RESUMEN

Cystic hepatic neoplasms are rare tumors, and are classified into two separate entities: mucinous cystic neoplasms (MCNs) and intraductal papillary mucinous neoplasms of the bile duct (IPMN-B). We report the case of a 56-year-old woman who presented with abdominal pain and jaundice due to the presence of a large hepatic multilocular cystic tumor associated with an intraductal tumor. Partial hepatectomy with resection of extrahepatic bile ducts demonstrated an intrahepatic MCN and an intraductal IPMN-B. This is the first report of the simultaneous occurrence of these two histologically distinct entities in the liver.


Asunto(s)
Neoplasias de los Conductos Biliares/complicaciones , Neoplasias de los Conductos Biliares/patología , Carcinoma Papilar/patología , Neoplasias Hepáticas/complicaciones , Neoplasias Hepáticas/patología , Neoplasias Primarias Múltiples/patología , Conductos Biliares Extrahepáticos/patología , Conductos Biliares Intrahepáticos/patología , Carcinoma Papilar/complicaciones , Colangiopancreatografia Retrógrada Endoscópica , Femenino , Humanos , Pruebas de Función Hepática , Imagen por Resonancia Magnética , Persona de Mediana Edad , Neoplasias Primarias Múltiples/diagnóstico , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
9.
Prz Gastroenterol ; 9(3): 168-71, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25097715

RESUMEN

Pancreatic mesenchymal neoplasms are very rare pancreatic tumours. One of them is pancreatic lipoma, often diagnosed incidentally. We herein report a case of a large lipoma of the pancreatic head, diagnosed by computed tomography and magnetic resonance imaging and confirmed by ultrasound-guided fine needle biopsy (FNA) biopsy. Regarding its benign character, silent clinical course and excellent prognosis of invasive surgical removal was avoided. We propose here the diagnostic and therapeutic management of these rare pancreatic tumours. Computed tomography is the most accurate method to diagnose pancreatic lipoma. Nevertheless large tumours may need confirmation by FNA in differential diagnosis of liposarcoma.

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