Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Eur Rev Med Pharmacol Sci ; 28(8): 3036-3040, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38708461

RESUMEN

OBJECTIVE: The primary aim of this study was to explore the involvement of cervical discopathy in the development of non-cyclic mastalgia by employing cervical magnetic resonance imaging (MRI). PATIENTS AND METHODS: A total of 407 patients were included in the study. Individualized management plans were developed for each patient. Pathological findings in MRI results were assessed by specialists in physical therapy and neurosurgery, and appropriate treatment was administered. Visual assessments of patients were conducted. The Analog Scale (VAS) scoring system was used at the initial presentation, and patients were evaluated at 1 and 3 months following the treatment. RESULTS: In the MRI examinations of the patients included in the study, simultaneous cervical disc protrusion was observed in 29% (n: 124) of those with annular bulging. Comparing the VAS scores of patients before treatment, at the 1st and at the 3rd month showed a significant decrease in mastalgia pain (p < 0.001). CONCLUSIONS: The diagnosis of cervical discopathy holds significant importance in the treatment of mastalgia patients. Therefore, clinicians should keep the cervical spine in mind as a potential contributing factor to mastalgia.


Asunto(s)
Vértebras Cervicales , Imagen por Resonancia Magnética , Mastodinia , Humanos , Femenino , Vértebras Cervicales/diagnóstico por imagen , Persona de Mediana Edad , Masculino , Adulto , Mastodinia/diagnóstico , Dimensión del Dolor , Degeneración del Disco Intervertebral/diagnóstico por imagen , Degeneración del Disco Intervertebral/diagnóstico , Desplazamiento del Disco Intervertebral/diagnóstico por imagen , Desplazamiento del Disco Intervertebral/diagnóstico , Anciano
2.
Folia Biol (Praha) ; 67(5-6): 163-173, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35439849

RESUMEN

Glucose is both the favourite carbon and energy source and acts as a hormone that plays a regulating role in many biological processes. Calorie restriction extends the lifespan in many organisms, including Schizosaccharomyces pombe, while uptake of high glucose leads to undesired results, such as diabetes and aging. In this study, sequence analysis of Schizosaccharomyces pombe ird5 and ird11 mutants was performed using next-generation sequencing techniques and a total of 20 different mutations were detected. ird11 is resistant to oxidative stress without calorie restriction, whereas ird5 displays an adaptive response against oxidative stress. We selected nine candidate mutations located in the non-coding (6) and coding (3) region among a total of 20 different mutations. The nine candidate mutations, which are thought to be responsible for ird5 and ird11 mutant phenotypes, were investigated via forward and backward mutations by using various cloning techniques. The results of this study provide report-like information that will contribute to understanding the relationship between glucose sensing/ signalling and oxidative stress response components.


Asunto(s)
Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Glucosa , Estrés Oxidativo/genética , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Transducción de Señal
3.
Sci Adv ; 5(4): eaav4310, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-31001586

RESUMEN

Anaerobic ammonium oxidation (anammox) is a major process in the biogeochemical nitrogen cycle in which nitrite and ammonium are converted to dinitrogen gas and water through the highly reactive intermediate hydrazine. So far, it is unknown how anammox organisms convert the toxic hydrazine into nitrogen and harvest the extremely low potential electrons (-750 mV) released in this process. We report the crystal structure and cryo electron microscopy structures of the responsible enzyme, hydrazine dehydrogenase, which is a 1.7 MDa multiprotein complex containing an extended electron transfer network of 192 heme groups spanning the entire complex. This unique molecular arrangement suggests a way in which the protein stores and releases the electrons obtained from hydrazine conversion, the final step in the globally important anammox process.


Asunto(s)
Proteínas Bacterianas/química , Hemo/química , Oxidorreductasas/química , Proteínas Bacterianas/metabolismo , Sitios de Unión , Dominio Catalítico , Microscopía por Crioelectrón , Cristalografía por Rayos X , Transporte de Electrón , Bacterias Gramnegativas/enzimología , Oxidorreductasas/metabolismo , Estructura Cuaternaria de Proteína
4.
Adv Microb Physiol ; 68: 219-352, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27134025

RESUMEN

Electron transport phosphorylation is the central mechanism for most prokaryotic species to harvest energy released in the respiration of their substrates as ATP. Microorganisms have evolved incredible variations on this principle, most of these we perhaps do not know, considering that only a fraction of the microbial richness is known. Besides these variations, microbial species may show substantial versatility in using respiratory systems. In connection herewith, regulatory mechanisms control the expression of these respiratory enzyme systems and their assembly at the translational and posttranslational levels, to optimally accommodate changes in the supply of their energy substrates. Here, we present an overview of methods and techniques from the field of proteomics to explore bacterial electron transfer chains and their regulation at levels ranging from the whole organism down to the Ångstrom scales of protein structures. From the survey of the literature on this subject, it is concluded that proteomics, indeed, has substantially contributed to our comprehending of bacterial respiratory mechanisms, often in elegant combinations with genetic and biochemical approaches. However, we also note that advanced proteomics offers a wealth of opportunities, which have not been exploited at all, or at best underexploited in hypothesis-driving and hypothesis-driven research on bacterial bioenergetics. Examples obtained from the related area of mitochondrial oxidative phosphorylation research, where the application of advanced proteomics is more common, may illustrate these opportunities.


Asunto(s)
Bacterias/metabolismo , Complejo II de Transporte de Electrones/ultraestructura , Complejo I de Transporte de Electrón/ultraestructura , Proteómica/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Espectrometría de Masas en Tándem/métodos , Adenosina Trifosfato/metabolismo , Transporte de Electrón , Oxidación-Reducción , Fosforilación Oxidativa , Estrés Oxidativo/fisiología , Oxígeno/metabolismo , Fosforilación/fisiología , Procesamiento Proteico-Postraduccional/fisiología
5.
Water Res ; 73: 323-31, 2015 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-25697694

RESUMEN

Anaerobic nitrogen removal technologies offer advantages in terms of energy and cost savings over conventional nitrification-denitrification systems. A mathematical model was constructed to evaluate the influence of process operation on the coexistence of nitrite dependent anaerobic methane oxidizing bacteria (n-damo) and anaerobic ammonium oxidizing bacteria (anammox) in a single granule. The nitrite and methane affinity constants of n-damo bacteria were measured experimentally. The biomass yield of n-damo bacteria was derived from experimental data and a thermodynamic state analysis. Through simulations, it was found that the possible survival of n-damo besides anammox bacteria was sensitive to the nitrite/ammonium influent ratio. If ammonium was supplied in excess, n-damo bacteria were outcompeted. At low biomass concentration, n-damo bacteria lost the competition against anammox bacteria. When the biomass loading closely matched the biomass concentration needed for full nutrient removal, strong substrate competition occurred resulting in oscillating removal rates. The simulation results further reveal that smaller granules enabled higher simultaneous ammonium and methane removal efficiencies. The implementation of simultaneous anaerobic methane and ammonium removal will decrease greenhouse gas emissions, but an economic analysis showed that adding anaerobic methane removal to a partial nitritation/anammox process may increase the aeration costs with over 20%. Finally, some considerations were given regarding the practical implementation of the process.


Asunto(s)
Compuestos de Amonio/metabolismo , Bacterias Anaerobias/metabolismo , Metano/metabolismo , Nitritos/metabolismo , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos , Anaerobiosis , Biomasa , Reactores Biológicos , Modelos Teóricos , Oxidación-Reducción
6.
Environ Technol ; 36(9-12): 1167-77, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25411102

RESUMEN

Autotrophic nitrogen removal in the mainstream wastewater treatment process is suggested to be a prerequisite of energy autarkic wastewater treatment plants (WWTP). Whilst the application of anammox-related technologies in the side-stream is at present state of the art, the feasibility of this energy-efficient process at mainstream conditions is still under development. Lower operating temperature and ammonium concentration, together with required high nitrogen removal efficiency, represent the main challenges to face in order to reach this appealing new frontier of the wastewater treatment field. In this study, we report the evaluation of the process in a plug-flow granular sludge-based pilot-scale reactor (4 m3) continuously fed with the actual effluent of the A-stage of the WWTP of Dokhaven, Rotterdam. The one-stage partial nitritation-anammox system was operated for more than 10 months at 19±1°C. Observed average N-removal and ammonium conversion rates were comparable or higher than those of conventional N-removal systems, with 182±46 and 315±33 mg-N L(-1) d(-1), respectively. Biochemical oxygen demand was also oxidized in the system with an average removal efficiency of 90%. Heterotrophic biomass grew preferentially in flocs and was efficiently washed out of the system. Throughout the experimentation, the main bottleneck was the nitritation process that resulted in nitrite-limiting conditions for the anammox conversion. Anammox bacteria were able to grow under mainstream WWTP conditions and new granules were formed and efficiently retained in the system.


Asunto(s)
Compuestos de Amonio/química , Reactores Biológicos , Nitrógeno/aislamiento & purificación , Aguas Residuales/química , Purificación del Agua , Anaerobiosis , Procesos Autotróficos , Biomasa , Estudios de Factibilidad , Oxidación-Reducción , Proyectos Piloto
7.
Water Res ; 66: 111-121, 2014 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-25201335

RESUMEN

Autotrophic nitrogen removal in the main stream appears as a prerequisite for the implementation of energy autarchic wastewater treatment plants. To investigate autotrophic nitrogen removal a lab-scale gas-lift sequencing batch reactor with granular sludge was operated for more than 500 days. The reactor was operated at temperatures between 20 and 10 °C on autotrophic medium with ammonium (60 and 160 mg-N L(-1)) as only nitrogen compound at an HRT of 0.23-0.3 d. The dissolved oxygen (DO) concentration was shown to be an effective control parameter for the suppression of the undesired nitratation process. DO control guaranteed the effective suppression of the nitratation both at 20 and 15 °C, allowing nitrogen removal rates of 0.4 g-NTot L(-1) d(-1) at nitrogen removal efficiencies of 85-75%. Prolonged operation at 10 °C caused a slow but unrestrainable decrease in anammox activity and process efficiency. This study represents a proof of concept for the application of the autotrophic nitrogen removal in a single reactor with granular sludge at main stream conditions.


Asunto(s)
Nitrógeno/metabolismo , Aguas del Alcantarillado/microbiología , Reactores Biológicos/microbiología , Frío , Eliminación de Residuos Líquidos , Aguas Residuales/microbiología , Purificación del Agua/métodos
8.
Environ Microbiol ; 12(12): 3264-71, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20649643

RESUMEN

Soil denitrification is a major source of nitrous oxide emission that causes ozone depletion and global warming. Low soil pH influences the relative amount of N2O produced and consumed by denitrification. Furthermore, denitrification is strongly inhibited in pure cultures of denitrifying microorganisms below pH 5. Soils, however, have been shown to denitrify at pH values as low as pH 3. Here we used a continuous bioreactor to investigate the possibility of significant denitrification at low pH under controlled conditions with soil microorganisms and naturally available electron donors. Significant NO3⁻ and N2O reduction were observed for 3 months without the addition of any external electron donor. Batch incubations with the enriched biomass showed that low pH as well as low electron donor availability promoted the relative abundance of N2O as denitrification end-product. Molecular analysis of the enriched biomass revealed that a Rhodanobacter-like bacterium dominated the community in 16S rRNA gene libraries as well as in FISH microscopy during the highest denitrification activity in the reactor. We conclude that denitrification at pH 4 with natural electron donors is possible and that a Rhodanobacter species may be one of the microorganisms involved in acidic denitrification in soils.


Asunto(s)
Desnitrificación , Óxido Nitroso/metabolismo , Microbiología del Suelo , Suelo/química , Xanthomonadaceae/metabolismo , Reactores Biológicos , Concentración de Iones de Hidrógeno , Nitrógeno/metabolismo , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Xanthomonadaceae/genética
10.
Biochem Soc Trans ; 34(Pt 1): 174-8, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16417514

RESUMEN

In the anaerobic ammonium oxidation (anammox) process, ammonia is oxidized with nitrite as primary electron acceptor under strictly anoxic conditions. The reaction is catalysed by a specialized group of planctomycete-like bacteria. These anammox bacteria use a complex reaction mechanism involving hydrazine as an intermediate. The reactions are assumed to be carried out in a unique prokaryotic organelle, the anammoxosome. This organelle is surrounded by ladderane lipids, which make the organelle nearly impermeable to hydrazine and protons. The localization of the major anammox protein, hydrazine oxidoreductase, was determined via immunogold labelling to be inside the anammoxosome. The anammox bacteria have been detected in many marine and freshwater ecosystems and were estimated to contribute up to 50% of oceanic nitrogen loss. Furthermore, the anammox process is currently implemented in water treatment for the low-cost removal of ammonia from high-strength waste streams. Recent findings suggested that the anammox bacteria may also use organic acids to convert nitrate and nitrite into dinitrogen gas when ammonia is in short supply.


Asunto(s)
Bacterias Anaerobias/metabolismo , Compuestos de Amonio Cuaternario/metabolismo , Ácidos/química , Ácidos/metabolismo , Anaerobiosis , Bacterias Anaerobias/citología , Biopelículas , Hidrazinas/metabolismo
11.
Biochem Soc Trans ; 33(Pt 1): 119-23, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15667281

RESUMEN

The obligately anaerobic ammonium oxidation (anammox) reaction with nitrite as primary electron acceptor is catalysed by the planctomycete-like bacteria Brocadia anammoxidans, Kuenenia stuttgartiensis and Scalindua sorokinii. The anammox bacteria use a complex reaction mechanism involving hydrazine as an intermediate. They have a unique prokaryotic organelle, the anammoxosome, surrounded by ladderane lipids, which exclusively contains the hydrazine oxidoreductase as the major protein to combine nitrite and ammonia in a one-to-one fashion. In addition to the peculiar microbiology, anammox was shown to be very important in the oceanic nitrogen cycle, and proved to be a very good alternative for treatment of high-strength nitrogenous waste streams. With the assembly of the K. stuttgartiensis genome at Genoscope, Evry, France, the anammox reaction has entered the genomic and proteomic era, enabling the elucidation of many intriguing aspects of this fascinating microbial process.


Asunto(s)
Compuestos de Amonio Cuaternario/metabolismo , Anaerobiosis , Oxidación-Reducción
12.
Toxicol Lett ; 85(1): 9-15, 1996 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8619262

RESUMEN

Biochemical and histopathological parameters of the ovarian function were observed to assess the toxic effect of low dose of atrazine, an s-triazine herbicide, in female pigs (gilts) undergoing intensive breeding. Female pigs (cross-bred between Swedish and German landrace) received 2 mg atrazine kg-1 body wt. in feed daily during 19 days of the oestrous cycle. The last treatment day corresponded to day -3 of the onset of the next expected oestrus. Blood samples were collected 3 times daily at 3-h intervals on the first 5 post-treatment days. Serum 17 beta-oestradiol (17 beta-E) and progesterone (P) concentrations were determined. A significantly higher (P < 0.05 and P < 0.001, respectively) serum 17 beta-E concentration was recorded 48 and 24 h before the onset of the next expected oestrus in atrazine-treated pigs, as compared to intact pigs. The onset of the next expected oestrus failed to occur, but no other adverse clinical reactions associated with the treatment were recorded. Histopathological examination of the ovaries of treated pigs indicated multiple ovarian follicular cysts and persistence of corpus luteum. Biochemical and histopathological findings showed that subacute exposure of female pigs to low dose of atrazine prolonged their oestrous cycle.


Asunto(s)
Atrazina/toxicidad , Estradiol/sangre , Herbicidas/toxicidad , Quistes Ováricos/veterinaria , Progesterona/sangre , Enfermedades de los Porcinos/inducido químicamente , Administración Oral , Animales , Atrazina/administración & dosificación , Cuerpo Lúteo/patología , Estro/efectos de los fármacos , Femenino , Herbicidas/administración & dosificación , Quistes Ováricos/inducido químicamente , Quistes Ováricos/patología , Folículo Ovárico/patología , Porcinos , Enfermedades de los Porcinos/patología
13.
Bull Environ Contam Toxicol ; 56(2): 225-30, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8720093

RESUMEN

Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) a s-triazine herbicide, has been widely used in Croatian agriculture. Due to atrazine extensive use and its biodegradation in nature within at least one year (Klassen and Kodoum 1979), atrazine residues are found in ground, surface, drain and drinking water (Vidacek et al. 1994; Gojmerac et al. 1994). Groundwater downgradient from atrazine treated fields may show seasonal concentration peaks which could exceed the safe level (Wehtje et al. 1983). Therefore, the use of atrazine includes permanent control of its residues in water, particularly in relation to its use as a herbicidal chemical and groundwater contamination (Graham 1991). Furthermore, the presence of atrazine in the environment and its possible ingestion via the water, food and feed chain, may present a risk for the animal and human health. The analysis of atrazine residues in soil can be performed by either colorimetry or high performance liquid chromatography (HPLC) (Vickrey et al. 1980), and in water, soil and food by immunoassay in comparison with HPLC or gas chromatography/mass spectrometry (GS-MS) (Bushway et al. 1988; Bushway et al. 1989; Bushway et al. 1992; Thurman et al. 1990). We describe the use of enzyme-linked immunosorbent assay (ELISA) for one-year seasonal monitoring of atrazine residues in drinking water from two differently situated pig-breeding farms (agricultural and industrial areas) in Croatia. Results obtained by ELISA were compared to those produced by HPLC.


Asunto(s)
Agricultura , Atrazina/análisis , Herbicidas/análisis , Estaciones del Año , Porcinos , Contaminantes Químicos del Agua/análisis , Abastecimiento de Agua/análisis , Crianza de Animales Domésticos , Animales , Cromatografía Líquida de Alta Presión , Croacia , Ensayo de Inmunoadsorción Enzimática , Industrias
14.
J Appl Toxicol ; 15(3): 233-6, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-7560745

RESUMEN

Biochemical and histopathological parameters of the hepatic function were used to quantify the hepatotoxic effects of atrazine in female pigs (gilts) undergoing intensive breeding. Female pigs (cross-bred Swedish and German landrace) received 2 mg atrazine kg-1 body wt. in feed daily during 19 days of the oestrous cycle. The last treatment day corresponded to day -3 of the onset of the next expected oestrus. Blood samples were collected three times daily at 3-h intervals on the first four post-treatment days. Serum activities of gamma-glutamyltransferase (GGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (AP) were determined. Serum activity of GGT was significantly increased throughout the four post-treatment days. In comparison with the control values, a slight but not significant decrease was observed in the serum activities of ALT, AST and AP. Histopathological examination of the liver of exposed pigs showed mild centrolobular parenchymatous degeneration. Interstitial connective tissue proliferation resulted in narrow and irregular bile canaliculi.


Asunto(s)
Atrazina/toxicidad , Hígado/efectos de los fármacos , Alanina Transaminasa/sangre , Fosfatasa Alcalina/sangre , Animales , Aspartato Aminotransferasas/sangre , Atrazina/administración & dosificación , Bilis/metabolismo , Tejido Conectivo/patología , Estro , Femenino , Hígado/patología , Hígado/fisiología , Pruebas de Función Hepática , Espectrofotometría Ultravioleta , Porcinos , gamma-Glutamiltransferasa/sangre
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...