Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 101
Filtrar
1.
J Orthop Surg Res ; 18(1): 967, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-38098039

RESUMEN

BACKGROUND: Eccentric muscle contraction can cause muscle damage, which reduces the efficiency of exercise. Previous evidence suggested that Sodium salicylate (SS) could improve the repair of aged muscle. This study intends to investigate whether SS can impact skeletal muscle damage caused by eccentric exercise. METHODS: Eccentric treadmill exercise was performed to induce muscle damage in mice. Plasma levels of muscle damage markers were estimated. RT-qPCR was employed for detecting mRNA levels of proinflammatory mediators in murine gastrocnemius muscle. Immunofluorescence staining of laminin/DAPI was utilized for quantifying centrally nucleated myofibers in the gastrocnemius muscle. Western blotting was implemented to examine protein levels of mitsugumin 53 (MG53), matrix metalloproteinase (MMP)-2/9, and NF-κB signaling-related markers. RESULTS: SS administration reduced muscle damage marker production in the plasma and decreased the levels of proinflammatory mediators, MG53 and MMP-2/9 in mice after exercise. SS alleviated the severity of muscle damage in the gastrocnemius of mice after eccentric exercise. SS blocked NF-κB signaling pathway in the gastrocnemius muscle. CONCLUSION: SS administration ameliorates skeletal muscle damage caused by eccentric exercise in the mouse model.


Asunto(s)
FN-kappa B , Salicilato de Sodio , Ratones , Animales , FN-kappa B/metabolismo , Salicilato de Sodio/farmacología , Salicilato de Sodio/metabolismo , Transducción de Señal , Músculo Esquelético/metabolismo , Contracción Muscular/fisiología , Proteínas de la Membrana/metabolismo
2.
Sci Rep ; 13(1): 10045, 2023 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-37344526

RESUMEN

Unintended side effects linked to the antineoplastic drug cisplatin are a major drawback in its clinical application. The underlying source of these side effects include the generation of reactive oxygen species which are toxic and damaging to tissues and organs. In the present study the anti-inflammatory and antioxidant potential of sodium salicylate was assessed against cisplatin-induced hepatotoxicity in albino rats. Sodium salicylate was used as a model drug and loading into hollow structured porous silica using ultrasound-assisted sol-gel method to produce a nanoemulsion. Transmission Electron Microscopy and Dynamic Light scattering analysis were employed to assess the structural properties and stability of this model. Liver function was assessed by measuring biomarkers including ALT, AST & GGT and oxidant/antioxidant markers including MDA, NO, PON, GSH, MCP1 & AVP in serum or liver tissue. Additionally, blood leukocyte DNA damage was evaluated. Cisplatin significantly altered the normal levels of all biomarkers confirming its hepatotoxic effects. In contrast, treatment with sodium salicylate-loaded silica nanoemulsion significantly restored the levels of these markers. The finding suggests the protective effects of this model drug in preventing cisplatin-induced hepatotoxicity, and therefore may have implications in attenuating cisplatin-induced hepatotoxicity.


Asunto(s)
Antineoplásicos , Enfermedad Hepática Inducida por Sustancias y Drogas , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Nanopartículas , Ratas , Animales , Cisplatino/toxicidad , Antioxidantes/farmacología , Antioxidantes/metabolismo , Salicilato de Sodio/metabolismo , Salicilato de Sodio/farmacología , Estrés Oxidativo , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Antineoplásicos/toxicidad , Hígado/metabolismo , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/metabolismo , Biomarcadores/metabolismo
3.
Mol Metab ; 56: 101425, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34954383

RESUMEN

INTRODUCTION: High-fat diet (HFD)-induced obesity impairs clearance of cholesterol through the Reverse Cholesterol Transport (RCT) pathway, with downregulation in hepatic expression of cholesterol and bile acid transporters, namely ABCG5/8 and ABCB11, and reduced high-density lipoprotein (HDL) cholesterol efflux capacity (CEC). In the current study, we hypothesized that the development of hepatosteatosis, secondary to adipose-tissue dysfunction, contributes to obesity-impaired RCT and that such effects could be mitigated using the anti-inflammatory drug sodium salicylate (NaS). MATERIALS AND METHODS: C57BL/6J mice, fed HFD ± NaS or low-fat diet (LFD) for 24 weeks, underwent glucose and insulin tolerance testing. The 3H-cholesterol movement from macrophage-to-feces was assessed in vivo. HDL-CEC was determined ex vivo. Cytokine secretion from adipose-derived stromal vascular fraction (SVF) cells was measured ex vivo. Liver and HDL proteins were determined by mass spectrometry and analyzed using Ingenuity Pathway Analysis. RESULTS: NaS delayed HFD-induced weight gain, abrogated priming of pro-IL-1ß in SVFs, attenuated insulin resistance, and prevented steatohepatitis (ectopic fat accumulation in the liver). Prevention of hepatosteatosis coincided with increased expression of PPAR-alpha/beta-oxidation proteins with NaS and reduced expression of LXR/RXR-induced proteins including apolipoproteins. The latter effects were mirrored within the HDL proteome in circulation. Despite remarkable protection shown against steatosis, HFD-induced hypercholesterolemia and repression of the liver-to-bile cholesterol transporter, ABCG5/8, could not be rescued with NaS. DISCUSSIONS AND CONCLUSIONS: The cardiometabolic health benefits of NaS may be attributed to the reprogramming of hepatic metabolic pathways to increase fatty acid utilization in the settings of nutritional overabundance. Reduced hepatic cholesterol levels, coupled with reduced LXR/RXR-induced proteins, may underlie the lack of rescue of ABCG5/8 expression with NaS. This remarkable protection against HFD-induced hepatosteatosis did not translate to improvements in cholesterol homeostasis.


Asunto(s)
Obesidad , Salicilato de Sodio , Animales , Colesterol/metabolismo , Hígado/metabolismo , Redes y Vías Metabólicas , Ratones , Ratones Endogámicos C57BL , Obesidad/metabolismo , Salicilato de Sodio/metabolismo , Salicilato de Sodio/farmacología
4.
Microbiology (Reading) ; 162(5): 764-776, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-26944926

RESUMEN

The cellular proteolytic machinery orchestrates protein turnover and regulates several key biological processes. This study addresses the roles of Lon, a major ATP-dependent protease, in modulating the responses of Escherichia coli strain MG1655 to low and high amounts of sodium salicyclate (NaSal), a widely used clinically relevant analgesic. NaSal affects several bacterial responses, including growth and resistance to multiple antibiotics. The loss of lon reduces growth in response to high, but not low, amounts of NaSal. From amongst a panel of Lon substrates, MarA was identified to be the downstream target of Lon. Thus, stabilization of MarA in the absence of lon lowers growth of the strain in the presence of higher amounts of NaSal. The steady-state transcript levels of marA and its target genes, acrA, acrB and tolC, are higher in the Δlon strain compared with the WT strain. Consequently, the resistance to antibiotics, e.g. tetracycline and nalidixic acid, is enhanced in Δlon in a marA-dependent manner. Furthermore, the target genes of MarA, i.e. acrB and tolC, are responsible for NaSal-mediated antibiotic resistance. Studies using atomic force microscopy demonstrated that ciprofloxacin led to greater cell filamentation, which is lower in the Δlon strain due to higher levels of MarA. Overall, this study delineates the roles of Lon protease, its substrate MarA and downstream targets of MarA, e.g. acrB and tolC, during NaSal-mediated growth reduction and antibiotic resistance. The implications of these observations in the adaptation of E. coli under different environmental conditions are discussed.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Farmacorresistencia Bacteriana Múltiple/genética , Proteínas de Escherichia coli/metabolismo , Escherichia coli/crecimiento & desarrollo , Proteasa La/metabolismo , Salicilato de Sodio/farmacología , Antibacterianos/farmacología , Proteínas de la Membrana Bacteriana Externa/genética , Ciprofloxacina/farmacología , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Lipoproteínas/genética , Proteínas de Transporte de Membrana/genética , Pruebas de Sensibilidad Microbiana , Microscopía de Fuerza Atómica , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Ácido Nalidíxico/farmacología , Proteasa La/genética , Salicilato de Sodio/metabolismo , Tetraciclina/farmacología , Resistencia a la Tetraciclina/genética
5.
Biotechnol Lett ; 37(8): 1693-701, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25836371

RESUMEN

OBJECTIVES: To evaluate sodium salicylate (NaSA) as an elicitor of rosmarinic acid (RA) and phenolic diterpenes, carnosol (C) and carnosic acid (CA) production, in a culture of Salvia officinalis shoots. RESULTS: In sage shoots grown in vitro, 28 polyphenolic compounds (phenolic acids, flavonoids, and phenolic diterpenes) were identified. In shoots treated for 1 week with increasing NaSA concentrations, the content of C increased from 2.3 in control to 5.7 mg g(-1) DW in shoots treated with 500 µM NaSA. In shoots that were recovered on basal medium for 3 weeks, the maximal amount of C (14 mg/g(-1) DW) was with 150 µM NaSA treatment. In treated and recovered shoots, the increase in C was accompanied with a decrease in CA, resulting in 1.9-fold increase in the C/CA ratio. Accumulation of RA was not affected by the NaSA treatment. However, elicitation by NaSA was accompanied with growth retardation. CONCLUSIONS: NaSA can improve C production in sage shoot culture, probably by stimulating the conversion of CA to C.


Asunto(s)
Abietanos/metabolismo , Cinamatos/metabolismo , Depsidos/metabolismo , Brotes de la Planta/efectos de los fármacos , Salvia officinalis/efectos de los fármacos , Salicilato de Sodio/metabolismo , Medios de Cultivo/química , Desarrollo de la Planta/efectos de los fármacos , Brotes de la Planta/crecimiento & desarrollo , Brotes de la Planta/metabolismo , Salvia officinalis/crecimiento & desarrollo , Salvia officinalis/metabolismo , Ácido Rosmarínico
6.
J Bacteriol ; 195(15): 3341-51, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23687277

RESUMEN

The Escherichia coli regulator MarR represses the multiple-antibiotic resistance operon marRAB and responds to phenolic compounds, including sodium salicylate, which inhibit its activity. Crystals obtained in the presence of a high concentration of salicylate indicated two possible salicylate sites, SAL-A and SAL-B. However, it was unclear whether these sites were physiologically significant or were simply a result of the crystallization conditions. A study carried out on MarR homologue MTH313 suggested the presence of a salicylate binding site buried at the interface between the dimerization and the DNA-binding domains. Interestingly, the authors of the study indicated a similar pocket conserved in the MarR structure. Since no mutagenesis analysis had been performed to test which amino acids were essential in salicylate binding, we examined the role of residues that could potentially interact with salicylate. We demonstrated that mutations in residues shown as interacting with salicylate at SAL-A and SAL-B in the MarR-salicylate structure had no effect on salicylate binding, indicating that these sites were not the physiological regulatory sites. However, some of these residues (P57, R86, M74, and R77) were important for DNA binding. Furthermore, mutations in residues R16, D26, and K44 significantly reduced binding to both salicylate and 2,4-dinitrophenol, while a mutation in residue H19 impaired the binding to 2,4-dinitrophenol only. These findings indicate, as for MTH313, the presence of a ligand binding pocket located between the dimerization and DNA binding domains.


Asunto(s)
Antibacterianos/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Salicilato de Sodio/metabolismo , 2,4-Dinitrofenol/metabolismo , Sitios de Unión , Análisis Mutacional de ADN , ADN Bacteriano/metabolismo , Modelos Moleculares , Unión Proteica , Conformación Proteica , Multimerización de Proteína , Estructura Terciaria de Proteína
7.
Rev. fitoter ; 11(1): 61-75, jul. 2011. ilus, tab
Artículo en Español | IBECS | ID: ibc-91572

RESUMEN

Se presentan aspectos etnomédicos, farmacológicos, fotoquímicos e históricos de la utilidad medicinal de algunos sauces (Salix), árboles que habitan en zonas templadas y lugares húmedos, que ya eran recomendades por Hipócrates y Dioscórides como remedio para el dolor, aliviar la fiebre y diferentes enfermedades. En la Edad Medica, y según la teoría de las señales (signos, o signaturas) , se consideran que podían ser empleados contra las fiebres intermitentes, el reumatismo, los resfriados, la fiebre, la gripe y los dolores articulares. Actualmente son empleados con esas mismas y otras finalidades en Fitoterapia y en la medicina tradicional de numerosas culturas. Contienen salicósidos (glucósido-fenoles), como la salicina (su principio activo), de donde se aisló el ácido salicílico, después obtenido en forma sintética y con el que se fabrica el medicamento llamado Aspirina, que tiene gran diversidad de aplicaciones medicinales (AU)


Ethnomedical, pharmacological, phytochemical, toxicological, historical aspects of the medicinal utility of some species willows (Salix), trees that inhabit tempered zones and humid places are presented. Hippocrates and Dioscorides already recommended their se to relief pain, a s a fever remedy and in the treatment of different malaises. In the Middle-Age, and according with the theory of the signals (signs, or signatures), they were considered against the intermittent fevers, rheumatism, flu, fever, and articulation pains. Actually is used with the same and other purposes in the traditional medicine of different cultures. The tree elaborates salicosides (phenol, glycosides), like salicine (their active principle), of where the salicylic acid was isolated, later obtained in synthetic form, and which the Aspirin drug was made of that has a great diversity of medicinal uses (AU)


Asunto(s)
Humanos , Masculino , Femenino , Plantas Medicinales , Extractos Vegetales/uso terapéutico , Salix , Salicilato de Sodio/uso terapéutico , Aspirina/uso terapéutico , Fitoterapia/métodos , Fitoterapia , Salix/metabolismo , Salicilato de Sodio/metabolismo , Salicilato de Sodio/farmacología
8.
Am J Physiol Cell Physiol ; 297(2): C290-8, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19515900

RESUMEN

Prestin is a membrane protein expressed in the outer hair cells (OHCs) in the cochlea that is essential for hearing. This unique motor protein transduces a change in membrane potential into a considerable mechanical force, which leads to a cell length change in the OHC. The nonlinear capacitance in cells expressing prestin is recognized to reflect the voltage-dependent conformational change of prestin, of which its precise nature remains unknown. In the present work, we aimed to detect the conformational changes of prestin by a fluorescence resonance energy transfer (FRET)-based technique. We heterologously expressed prestin labeled with fluorophores at the COOH- or NH(2)-terminus in human embryonic kidney-293T cells, and monitored FRET changes on depolarization-inducing high KCl application. We detected a significant decrease in intersubunit FRET both between the COOH-termini and between the COOH- and NH(2)-termini. A similar FRET decrease was observed when membrane potential was directly and precisely controlled by simultaneous patch clamp. Changes in FRET were suppressed by either of two treatments known to abolish nonlinear capacitance, V499G/Y501H mutation and sodium salicylate. Our results are consistent with significant movements in the COOH-terminal domain of prestin upon change in membrane potential, providing the first dynamic information on its molecular rearrangements.


Asunto(s)
Proteínas de Transporte de Anión/química , Proteínas de Transporte de Anión/metabolismo , Transferencia Resonante de Energía de Fluorescencia/métodos , Proteínas de Transporte de Anión/genética , Antiinflamatorios no Esteroideos/metabolismo , Línea Celular , Células Ciliadas Auditivas Externas/metabolismo , Humanos , Potenciales de la Membrana/fisiología , Técnicas de Placa-Clamp , Subunidades de Proteína/química , Subunidades de Proteína/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Salicilato de Sodio/metabolismo , Transportadores de Sulfato
9.
Biochemistry ; 48(10): 2099-108, 2009 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-19166356

RESUMEN

While a rich collection of bacterium-like regulating proteins has been identified in the archaeal genome, few of them have been studied at the molecular level. In this study, we characterized the ligand and DNA binding properties of a putative regulator ST1710 from the archaeon Sulfolobus tokodaii. ST1710 is homologous to the multiple-antibiotic resistance repressor (MarR) family bacterial regulators. The protein consists of a ligand binding site, partially overlapping with a winged helix-turn-helix DNA binding site. We characterized the interactions between ST1710 and three ligands, salicylate, carbonyl cyanide m-chlorophenylhydrazone (CCCP), and ethidium, which bind to bacterial MarRs. The binding affinities of the ligands for ST1710 were comparable to their affinities for the bacterial MarRs. The ligand binding was temperature sensitive and caused conformational changes in ST1710. To investigate the effect of ligand binding on the interaction between ST1710 and DNA, we fluorescently labeled a 47mer dsDNA (ST1) containing a putative ST1710 recognition site and determined the dissociation constant between ST1 and ST1710 using the fluorescence polarization method. The binding affinity almost doubled from 10 degrees C (Kd = 618 +/- 34 nM) to 30 degreesC (Kd = 334 +/- 15 nM), and again from 30 to 50 degrees C (Kd = 189 +/- 9 nM). This result suggests that under the natural living condition (80 degrees C) of S. tokodaii, the binding affinity might increase even further. The presence of CCCP and salicylate suppressed ST1710-ST1 interaction, indicating that ST1710 functioned as a repressor.


Asunto(s)
Proteínas Arqueales/metabolismo , ADN/química , Ligandos , Proteínas Represoras/metabolismo , Proteínas Arqueales/genética , Carbonil Cianuro m-Clorofenil Hidrazona/análogos & derivados , Carbonil Cianuro m-Clorofenil Hidrazona/química , Carbonil Cianuro m-Clorofenil Hidrazona/metabolismo , Carbonil Cianuro m-Clorofenil Hidrazona/farmacología , Dicroismo Circular , ADN/metabolismo , Etidio/química , Etidio/metabolismo , Polarización de Fluorescencia , Modelos Moleculares , Unión Proteica/efectos de los fármacos , Unión Proteica/genética , Conformación Proteica/efectos de los fármacos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Represoras/genética , Salicilato de Sodio/química , Salicilato de Sodio/metabolismo , Salicilato de Sodio/farmacología , Espectrometría de Fluorescencia , Sulfolobus/genética , Temperatura
10.
Prostaglandins Other Lipid Mediat ; 83(3): 175-81, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17481552

RESUMEN

Cyclooxygenase-2 (COX-2) overexpression is associated with cancer. One potential mechanism is DNA damage caused by COX-2 derived oxidants. Since DNA in proliferating cells is highly vulnerable to oxidative damage and mutation, we propose that COX-2 transactivation by exogenous stimuli is suppressed in proliferating cells compared to quiescent cells. In this review, we provide evidence for reduced COX-2 transcriptional expression in response to phorbol esters (PMA), lipopolysaccharide (LPS), interleukin-1beta (IL-1beta) and tumor necrosis factor alpha (TNFalpha). Our results show that COX-2 transcription in proliferating fibroblasts is suppressed by a small molecular weight compound produced by proliferating cells. By contrast, COX-2 expression in response to exogenous stimuli is robust in quiescent cells. The quiescent cells in human body may play a primary role in mounting response to exogenous stimuli. Salicylate inhibits COX-2 transcriptional activation in quiescent cells but not in serum-driven proliferating cells by blocking C/EBPbeta DNA binding. These studies suggest that COX-2 expressions in quiescent and proliferating cells are regulated by different mechanisms. Further investigations into their transcriptional control mechanisms will have great impact on the fundamental understanding of the division of cell functions between quiescent and proliferating cells and the design of novel therapeutic strategies.


Asunto(s)
Ciclooxigenasa 2/metabolismo , Fibroblastos/metabolismo , Regulación Enzimológica de la Expresión Génica , Animales , Proliferación Celular/efectos de los fármacos , Medios de Cultivo Condicionados/química , Medios de Cultivo Condicionados/farmacología , Ciclooxigenasa 2/genética , Fibroblastos/efectos de los fármacos , Fibroblastos/enzimología , Fibroblastos/fisiología , Humanos , Interleucina-1beta/farmacología , Lipopolisacáridos/farmacología , Salicilato de Sodio/metabolismo , Salicilato de Sodio/farmacología , Acetato de Tetradecanoilforbol/análogos & derivados , Acetato de Tetradecanoilforbol/farmacología , Transcripción Genética/efectos de los fármacos , Activación Transcripcional , Factor de Necrosis Tumoral alfa/farmacología
11.
Water Res ; 40(19): 3517-26, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17011016

RESUMEN

A polypropylene (PP) hollow fiber membrane contactor was used as a reactor to enhance the biodegradation of equimolar phenol and sodium salicylate (SA) by Pseudomonas putida CCRC 14365 at 30 degrees C and pH 7. Experiments were performed at a fixed initial cell density of 0.025 g/L and in the total substrate level range 5.32-63.8 mM. The degradation experiments by free cells were also studied for comparison. With pristine hydrophobic fibers, the degradation of SA was started only after phenol was completely consumed. Substrate inhibitory effect was avoided due to sufficiently low substrate levels in the cell medium; however, the biodegradation was time consuming. With ethanol-wetted fibers, both substrates were completely degraded much faster than the use of pristine fibers. Although the wetted fibers were unable to prevent movement of substrates through the pores, biofilm formed on the outer surfaces of the fibers could enhance the tolerance limit of substrate toxicity. This greatly extended the treatment range to high-level substrate mixtures, as long as the water was nearly neutral and free of concentrated inorganic salts.


Asunto(s)
Reactores Biológicos , Membranas Artificiales , Fenol/metabolismo , Pseudomonas putida/metabolismo , Salicilato de Sodio/metabolismo , Biodegradación Ambiental , Etanol/química , Interacciones Hidrofóbicas e Hidrofílicas , Fenol/química , Polipropilenos/química , Porosidad , Pseudomonas putida/crecimiento & desarrollo , Sensibilidad y Especificidad , Salicilato de Sodio/química , Propiedades de Superficie , Factores de Tiempo , Agua/química , Humectabilidad
12.
J Hazard Mater ; 138(1): 125-32, 2006 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-16806688

RESUMEN

The biodegradation of single phenol and sodium salicylate (SA) and their binary mixtures in water by free Pseudomonas putida (P. putida) CCRC 14365 was experimentally studied at 30 degrees C and pH 7. The initial concentration of the cells, adapted with either phenol or SA, was maintained at 0.025 g/L. Single substrate experiments were performed in the substrate level range 0.53-3.18 mM. The Haldane model has shown that phenol was biodegraded more quickly (mu(max)=0.245 h(-1)) than SA (0.137 h(-1)) under the ranges studied, and SA had a more inhibitory effect on cell growth (K(I)=5.21 mM) than phenol (12.6 mM) at low substrate levels even by SA-adapted cells. Binary substrate experiments were carried out at two fixed total substrate levels of 1.06 and 3.18 mM, with a varying molar concentration ratio of 0.33-3.0. The presence of a small amount of phenol to SA could significantly enhance the biodegradation of SA, particularly when the phenol-adapted cells were employed. On the other hand, the addition of a small amount of SA to phenol would retard the biodegradation of phenol, especially at higher total substrate levels (3.18 mM).


Asunto(s)
Fenoles/metabolismo , Pseudomonas putida/metabolismo , Salicilato de Sodio/metabolismo , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/metabolismo , Purificación del Agua/métodos , Biodegradación Ambiental , Concentración de Iones de Hidrógeno , Residuos Industriales , Cinética
13.
Hear Res ; 193(1-2): 68-74, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15219321

RESUMEN

To investigate the effects of the tinnitus inducer, sodium salicylate, on voltage-gated sodium channels, we studied freshly dissociated inferior colliculus neurons of rats by the whole-cell voltage clamp method. Salicylate blocked sodium channels in concentration-dependent manner (0.1-10 mM), and the IC50 value of salicylate was estimated to be 1.43 mM after application. The sodium conductance-voltage curve did not shift along the voltage axis with salicylate application. In contrast, the steady-state sodium channel inactivation curve was shifted by about 9 mV in the hyperpolarizing direction. In addition, salicylate delayed the sodium channel recovery from inactivation by increasing the slow time constant. It was concluded that salicylate bound to the resting and inactivated sodium channels to cause blocking, with a higher affinity for the latter state. Our results suggest that salicylate causes a concentration-dependent blockade of voltage-gated sodium channels and shifts the inactivation curve to more hyperpolarized potentials, which could be related to the mechanism of salicylate-induced tinnitus.


Asunto(s)
Colículos Inferiores/fisiología , Activación del Canal Iónico , Neuronas/fisiología , Bloqueadores de los Canales de Sodio/farmacología , Canales de Sodio/efectos de los fármacos , Canales de Sodio/metabolismo , Salicilato de Sodio/farmacología , Animales , Relación Dosis-Respuesta a Droga , Electrofisiología , Femenino , Colículos Inferiores/citología , Colículos Inferiores/metabolismo , Cinética , Masculino , Neuronas/metabolismo , Concentración Osmolar , Técnicas de Placa-Clamp , Ratas , Ratas Wistar , Bloqueadores de los Canales de Sodio/administración & dosificación , Bloqueadores de los Canales de Sodio/metabolismo , Salicilato de Sodio/administración & dosificación , Salicilato de Sodio/metabolismo
15.
Microbiology (Reading) ; 149(Pt 12): 3437-3447, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14663077

RESUMEN

PepN and its homologues are involved in the ATP-independent steps (downstream processing) during cytosolic protein degradation. To obtain insights into the contribution of PepN to the peptidase activity in Escherichia coli, the hydrolysis of a selection of endopeptidase and exopeptidase substrates was studied in extracts of wild-type strains and two pepN mutants, 9218 and DH5alphaDeltapepN. Hydrolysis of three of the seven endopeptidase substrates tested was reduced in both pepN mutants. Similar studies revealed that hydrolysis of 10 of 14 exopeptidase substrates studied was greatly reduced in both pepN mutants. This decreased ability to cleave these substrates is pepN-specific as there is no reduction in the ability to hydrolyse exopeptidase substrates in E. coli mutants lacking other peptidases, pepA, pepB or pepE. PepN overexpression complemented the hydrolysis of the affected exopeptidase substrates. These results suggest that PepN is responsible for the majority of aminopeptidase activity in E. coli. Further in vitro studies with purified PepN revealed a preference to cleave basic and small amino acids as aminopeptidase substrates. Kinetic characterization revealed the aminopeptidase cleavage preference of E. coli PepN to be Arg>Ala>Lys>Gly. Finally, it was shown that PepN is a negative regulator of the sodium-salicylate-induced stress in E. coli, demonstrating a physiological role for this aminoendopeptidase under some stress conditions.


Asunto(s)
Aminopeptidasas/metabolismo , Proteínas Bacterianas/metabolismo , Escherichia coli/enzimología , Secuencia de Aminoácidos , Aminopeptidasas/genética , Proteínas Bacterianas/genética , Secuencia de Bases , ADN Bacteriano/genética , Escherichia coli/genética , Hidrólisis , Cinética , Mutación , Salicilato de Sodio/metabolismo , Especificidad por Sustrato
16.
Int Endod J ; 36(10): 674-81, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-14511224

RESUMEN

AIM: To investigate the facilitative role of iontophoresis in drug delivery through intact and caries-affected dentine into the pulp. METHODOLOGY: Forty-eight intact dentine or caries-affected dentine discs were prepared from freshly extracted human third molars. The hydraulic conductance was measured before and after the experiments. Drug diffusion with and without iontophoresis (0.05 mA, 10 min) was evaluated using a split-chamber device. The enamel side chamber was filled with metronidazole (MN), sodium salicylate (SS) or naproxen sodium (NA), while the pulpal side was circulated with phosphate buffered saline (PBS) and pressurized (15 cmH2O). Samples were collected after 1 h. Drug concentrations of the pulpal side solution were determined using a spectrophotometer. Then, electrical impedance of each dentine disc was measured. Finally, the dentine disc surfaces were observed by scanning electron microscopy. RESULTS: Drug diffusion was significantly influenced by iontophoresis, caries-induced changes in dentine and the drugs used (three-way anova, P < 0.05). The diffusion of all the drugs through caries-affected dentine was significantly less than that through intact dentine (independent t-test, P < 0.05). Also, iontophoresis facilitated the diffusion of all the drugs through intact and caries-affected dentine. The drug diffusion of SS was significantly higher than MN and NA (one-way anova, P < 0.05), independent of iontophoresis. CONCLUSIONS: Presence of dental caries may inhibit drug diffusion through dentine into the pulp. However, iontophoresis could enhance the delivery of ionized drugs through both intact and caries-affected dentine.


Asunto(s)
Caries Dental/metabolismo , Dentina/metabolismo , Sistemas de Liberación de Medicamentos , Iontoforesis , Adulto , Análisis de Varianza , Antiinfecciosos/metabolismo , Antiinflamatorios no Esteroideos/metabolismo , Esmalte Dental/metabolismo , Pulpa Dental/metabolismo , Difusión , Impedancia Eléctrica , Humanos , Análisis por Apareamiento , Metronidazol/metabolismo , Microscopía Electrónica de Rastreo , Naproxeno/metabolismo , Salicilato de Sodio/metabolismo , Espectrofotometría , Factores de Tiempo
17.
Eur J Biochem ; 270(16): 3461-8, 2003 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12899704

RESUMEN

As heat shock proteins (Hsps) are involved in protecting cells and also in the pathophysiology of diseases such as inflammation, cancer and neurodegenerative disorders, modulators of Hsp expression in mammalian cells would seem to be useful for the treatment of various diseases. In this study, we isolated mammalian cell lines for screening of Hsp modulators; mouse C3H10T1/2 cells stably transfected with a plasmid containing the mouse Hsp105 or human Hsp70B promoter upstream of a luciferase or beta-galactosidase reporter gene, respectively. Using these cells, we examined the effect of sodium salicylate (SA), which may induce the transcription of hsp genes, on stress response in mammalian cells. When these cells were treated with SA for 1 h at 37 degrees C, both promoter activities were up-regulated by SA at concentrations of more than 45 mm. The activation of heat shock factor and the subsequent accumulation of Hsp105alpha and Hsp70 were detected in cells treated with SA at concentrations of more than 20 and 45 mm, respectively. Furthermore, SA induced resistance against a subsequent lethal stress. These findings suggested that SA is a potent hsp inducer, and may be used to protect cells against deleterious stressors.


Asunto(s)
Proteínas de Choque Térmico/metabolismo , Salicilato de Sodio/metabolismo , Animales , Calor , Ratones
18.
Biomaterials ; 24(20): 3571-83, 2003 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12809786

RESUMEN

The effect of the addition of small molecular weight anhydride oligomers to polymer microspheres was evaluated and increased bioadhesion of the composite was demonstrated. Blends of low molecular weight anhydride oligomers with thermoplastic poly(fumaric-co-sebacic anhydride) [p(FASA)] and polycaprolactone were examined. The effects of anhydride oligomers on polymer microsphere degradation, crystallinity, and surface morphology were also explored. The results demonstrated that fumaric anhydride oligomer remained within polymer microspheres for several hours after exposure to phosphate buffer, formed a homogenous crystalline blend, increased bioadhesion as measured on rat intestine, and enhanced drug delivery in vitro as measured by the everted sac technique.


Asunto(s)
Anhídridos/metabolismo , Materiales Biocompatibles/metabolismo , Sistemas de Liberación de Medicamentos , Microesferas , Polímeros/metabolismo , Anhídridos/química , Animales , Materiales Biocompatibles/química , Fumaratos/química , Fumaratos/metabolismo , Concentración de Iones de Hidrógeno , Técnicas In Vitro , Yeyuno/citología , Yeyuno/metabolismo , Microscopía Electrónica de Rastreo , Peso Molecular , Moco/química , Polímeros/química , Ratas , Salicilato de Sodio/metabolismo , Propiedades de Superficie , Temperatura , Adherencias Tisulares , Agua/química
19.
Appl Environ Microbiol ; 69(2): 1290-4, 2003 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12571060

RESUMEN

Sodium salicylate and ammonium sulfate were applied to leaf surfaces along with suspensions of the biological control agents Pseudomonas syringae Cit7(pNAH7), which catabolizes salicylate, and Cit7, which does not catabolize salicylate, to determine whether enhanced biological control of bacterial speck of tomato could be achieved. Foliar amendment with salicylate alone significantly enhanced the population size and the efficacy of Cit7(pNAH7), but not of Cit7, on tomato leaves. Application of ammonium sulfate alone did not result in enhanced population size or biological control efficacy of either Cit7(pNAH7) or Cit7; however, when foliar amendments with both sodium salicylate and ammonium sulfate were applied, a trend toward further increases in population size and biological control efficacy of Cit7(pNAH7) was observed. This study demonstrates the potential of using a selective carbon source to improve the efficacy of a bacterial biological control agent in the control of a bacterial plant disease and supports previous conclusions that the growth of P. syringae in the phyllosphere is primarily carbon limited and secondarily nitrogen limited.


Asunto(s)
Control Biológico de Vectores , Enfermedades de las Plantas/microbiología , Pseudomonas/crecimiento & desarrollo , Pseudomonas/patogenicidad , Solanum lycopersicum/microbiología , Sulfato de Amonio/metabolismo , Recuento de Colonia Microbiana , Hojas de la Planta/microbiología , Salicilato de Sodio/metabolismo
20.
Acta Microbiol Pol ; 52(4): 395-404, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-15095927

RESUMEN

New Planococcus sp. strain S5 able to grow on salicylate or benzoate as sole carbon source was isolated from activated sludge adapted to sodium salicylate degradation. S5 was determined to be a strictly aerobic, gram-positive, catalase positive, oxidase negative, non-motile, non-spore forming coccus. The strain harboured a plasmid, named pLS5. The S5 strain when grown on salicylate expressed both catechol 1,2-dioxygenase and catechol 2,3-dioxygenase activities and degraded this substrate by both the ortho and meta pathways while grown on benzoate expressed only catechol 1,2-dioxygenase activity. Curing of the plasmid from the strain showed that plasmid pLS5 was involved in salicylate degradation by the meta pathway.


Asunto(s)
Dioxigenasas , Cocos Grampositivos/aislamiento & purificación , Aguas del Alcantarillado/microbiología , Salicilato de Sodio/metabolismo , Benzoatos/metabolismo , Catecol 1,2-Dioxigenasa , Catecol 2,3-Dioxigenasa , ADN Bacteriano/química , ADN Bacteriano/genética , Cocos Grampositivos/genética , Cocos Grampositivos/metabolismo , Oxigenasas/metabolismo , Plásmidos/genética , Reacción en Cadena de la Polimerasa
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...