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2.
Food Chem Toxicol ; 59: 153-9, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23743120

RESUMEN

AIM OF THE STUDY: Korean red ginseng is one of the best selling dietary supplements and its individual constituents enhance renal function. Acute renal failure (ARF) is a predisposing complication of diabetes mellitus as a result of combination drug therapy. The combination of antibiotic-antidiabetic drugs can entail toxicities and drug interactions because of the antibiotic resistance in patients with severe bacterial infection. Currently, gentamicin-metformin combination therapy is commonly prescribed for treating bacterial infections and diabetes, even though both drugs are mainly excreted via the kidney. Thus, this study was designed to investigate whether a Korean red ginseng extract (KRG) prevents renal impairment and pharmacokinetic changes by metformin in rats with renal failure induced by gentamicin. MATERIALS AND METHODS: The in vivo pharmacokinetics and in vitro hepatic/intestinal metabolism of metformin were assessed using control (CON), control with Korean red ginseng extract (KRG-CON), acute renal failure induced by gentamicin (ARF), and ARF with Korean red ginseng (KRG-ARF) rats. RESULTS AND CONCLUSIONS: Pharmacokinetic changes of metformin did not occur in KRG-ARF rats because KRG reduce the renal accumulation of gentamicin compared to ARF rats. Thus, KRG seemed to prevent acute renal failure induced by gentamicin treatment.


Asunto(s)
Lesión Renal Aguda/prevención & control , Gentamicinas/farmacocinética , Metformina/farmacocinética , Panax/química , Extractos Vegetales/uso terapéutico , Raíces de Plantas/química , Sustancias Protectoras/uso terapéutico , Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/metabolismo , Lesión Renal Aguda/fisiopatología , Animales , Antibacterianos/efectos adversos , Antibacterianos/antagonistas & inhibidores , Antibacterianos/metabolismo , Antibacterianos/farmacocinética , Interacciones Farmacológicas , Gentamicinas/efectos adversos , Gentamicinas/antagonistas & inhibidores , Gentamicinas/metabolismo , Ginsenósidos/administración & dosificación , Ginsenósidos/análisis , Ginsenósidos/farmacología , Ginsenósidos/uso terapéutico , Hipoglucemiantes/efectos adversos , Hipoglucemiantes/sangre , Hipoglucemiantes/metabolismo , Hipoglucemiantes/farmacocinética , Mucosa Intestinal/metabolismo , Intestinos/efectos de los fármacos , Riñón/efectos de los fármacos , Riñón/fisiopatología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/fisiopatología , Masculino , Metformina/efectos adversos , Metformina/sangre , Metformina/metabolismo , Microsomas/efectos de los fármacos , Microsomas/metabolismo , Fitoterapia , Extractos Vegetales/química , Extractos Vegetales/farmacología , Sustancias Protectoras/química , Sustancias Protectoras/farmacología , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Distribución Tisular/efectos de los fármacos
3.
Science ; 339(6124): 1213-6, 2013 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-23471410

RESUMEN

Bactericidal antibiotics kill by modulating their respective targets. This traditional view has been challenged by studies that propose an alternative, unified mechanism of killing, whereby toxic reactive oxygen species (ROS) are produced in the presence of antibiotics. We found no correlation between an individual cell's probability of survival in the presence of antibiotic and its level of ROS. An ROS quencher, thiourea, protected cells from antibiotics present at low concentrations, but the effect was observed under anaerobic conditions as well. There was essentially no difference in survival of bacteria treated with various antibiotics under aerobic or anaerobic conditions. This suggests that ROS do not play a role in killing of bacterial pathogens by antibiotics.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Escherichia coli/efectos de los fármacos , Fluoroquinolonas/farmacología , Norfloxacino/farmacología , Especies Reactivas de Oxígeno/metabolismo , Anaerobiosis , Antibacterianos/antagonistas & inhibidores , Escherichia coli/metabolismo , Fluoroquinolonas/antagonistas & inhibidores , Norfloxacino/antagonistas & inhibidores , Estrés Oxidativo , Tiourea/farmacología
4.
Neuroscience ; 242: 1-10, 2013 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-23523747

RESUMEN

OBJECTIVE: Glutamate transporter-1 (GLT-1) maintains low concentrations of extracellular glutamate by removing glutamate from the extracellular space. It is controversial, however, whether upregulation of GLT-1 is neuroprotective under all ischemic/hypoxic conditions. Recently, a neuroprotective effect of preconditioning with a ß-lactam antibiotic ceftriaxone (CTX) that increases expression of GLT-1 has been reported in animal models of focal ischemia. On the other hand, it is said that CTX does not play a neuroprotective role in an in vitro study. Thus, we examined the effect of CTX on ischemic injury in a rat model of two-vein occlusion (2VO). This model mimics venous ischemia during, e.g. tumor surgery, a clinical situation that is best suitable for pretreatment with CTX. METHODS: CTX (100mg/kg, 200mg/kg per day) or vehicle (0.9% NaCl) was intraperitoneally injected into Wistar rats for 5days before venous ischemia (n=57). Then, animals were prepared for occlusion of two adjacent cortical veins (2VO) by photothrombosis with rose bengal that was followed by KCl-induced cortical spreading depression (CSD). Infarct volume was evaluated with hematoxylin and eosin (H&E) staining 2days after venous occlusion. [(3)H]MK-801, [(3)H]AMPA and [(3)H]Muscimol ligand binding were examined autoradiographically in additional two groups without 2VO (n=5/group). Animals were injected either with NaCl (vehicle) or CTX 200mg/kg for 5days in order to evaluate whether NMDA, AMPA and GABAA ligand binding densities were affected. RESULTS: CTX pretreatment reduced infarct volume compared to vehicle pretreatment (p<0.05). The effect of CTX pretreatment was attenuated by administration of the GLT-1 inhibitor, dihydrokainate (DHK) 30min before 2VO. CTX had no effect on the number of spontaneous spreading depressions after 2VO. Analysis of quantitative receptor autoradiography showed no statistically significant difference between rats after administration with CTX compared to control rats. CONCLUSIONS: Pretreatment with CTX has neuroprotective potential without effect on NMDA, AMPA and GABAA receptor density and spontaneous spreading depression. This effect can be abolished by GLT-1 inhibition, indicating that upregulation of GLT-1 is an important mechanism for neuroprotective action in penumbra-like conditions, e.g. if neurosurgeons plan to occlude cerebral veins during tumor surgery.


Asunto(s)
Antibacterianos/uso terapéutico , Isquemia Encefálica/patología , Isquemia Encefálica/prevención & control , Ceftriaxona/farmacología , Depresión de Propagación Cortical/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Animales , Antibacterianos/antagonistas & inhibidores , Antibacterianos/farmacología , Isquemia Encefálica/inducido químicamente , Isquemia Encefálica/metabolismo , Ceftriaxona/antagonistas & inhibidores , Infarto Cerebral/tratamiento farmacológico , Infarto Cerebral/patología , Interacciones Farmacológicas , Transportador 2 de Aminoácidos Excitadores/antagonistas & inhibidores , Ácido Kaínico/análogos & derivados , Ácido Kaínico/farmacología , Masculino , Cloruro de Potasio/farmacología , Ratas , Receptores AMPA/metabolismo , Receptores de GABA-A/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo
7.
Otol Neurotol ; 34(2): 353-9, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23444481

RESUMEN

HYPOTHESIS: The "in-bone" method of culturing utricles described here is a reliable and atraumatic technique for culturing mature mouse hair cells and studying hair cell death and protection. BACKGROUND: The current in vitro technique for studying hair cells of the mature mouse utricle involves removal from the temporal bone and free floating culture in media. This technique can be problematic because of variability in the preservation of the sensory epithelium and a steep learning curve that results in injury of the sensory epithelium in less experienced hands. We present a new atraumatic technique of culturing the utricle in situ within the temporal bone. METHODS: Leaving the temporal bone largely intact, a window is opened in the bony vestibule overlying the mouse utricle. The entire temporal bone is then placed into culture media. Utricles were cultured in situ for several days with minimal damage to the epithelium. The utricles are then fixed in situ, removed from the temporal bone, and processed. A standardized aminoglycoside-induced hair cell damage protocol was developed. RESULTS: Mature mouse utricles maintained hair cell numbers for 3 days in culture. Exposure to neomycin resulted in significant dose-dependent hair cell toxicity (p < 0.0001, 1-way analysis of variance). Exposure to the protective drug tacrine resulted in significant protection against neomycin (p < 0.05, 3-way analysis of variance). CONCLUSION: The "in-bone" technique is a reliable and atraumatic method for culturing mature mouse utricles and studying hair cell death and protection. It is easily mastered and can make in vitro study of hair cells accessible to more research groups.


Asunto(s)
Técnicas de Cultivo de Órganos/métodos , Sáculo y Utrículo/fisiología , Animales , Antibacterianos/antagonistas & inhibidores , Antibacterianos/farmacología , Antibacterianos/toxicidad , Recuento de Células , Muerte Celular/efectos de los fármacos , Medios de Cultivo , Relación Dosis-Respuesta a Droga , Células Ciliadas Auditivas/patología , Enfermedades del Laberinto/inducido químicamente , Enfermedades del Laberinto/patología , Enfermedades del Laberinto/prevención & control , Masculino , Ratones , Ratones Endogámicos CBA , Microscopía Confocal , Microscopía Electrónica de Rastreo , Neomicina/antagonistas & inhibidores , Neomicina/toxicidad , Nootrópicos/uso terapéutico , Ofloxacino/farmacología , Tacrina/uso terapéutico , Hueso Temporal/fisiología
8.
Reprod Toxicol ; 36: 71-7, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23261820

RESUMEN

Triclosan (TCS), an antibacterial, has been shown to be an endocrine disruptor in the rat. We reported previously that TCS potentiated the estrogenic effect of ethinyl estradiol (EE) on uterine growth in rats exposed to EE and TCS in the uterotrophic assay, whereas TCS alone had no effect. To further characterize this potentiation, we evaluated the effect of co-exposure with lower doses of EE that are comparable to the concentrations in hormone replacement regimens and began to assess the mechanisms by which this potentiation occurs. Changes in uterine weight, epithelial cell growth, and estrogen-sensitive gene expression were assessed. TCS expectedly enhanced the uterotrophic response to EE, however at significantly lower doses of EE. Similarly, TCS increased the EE-induced stimulation of epithelial cell height following cotreatment. Cotreatment also enhanced the estrogen-induced change in gene expression, which was reversed with an ER antagonist. Furthermore, the TCS-induced potentiation was independent of ER activation, as no effects were observed in the ER TA assay.


Asunto(s)
Disruptores Endocrinos/toxicidad , Estrógenos/agonistas , Etinilestradiol/agonistas , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Lesiones Precancerosas/inducido químicamente , Triclosán/toxicidad , Útero/efectos de los fármacos , Animales , Antibacterianos/administración & dosificación , Antibacterianos/antagonistas & inhibidores , Antibacterianos/toxicidad , Forma de la Célula/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Disruptores Endocrinos/administración & dosificación , Disruptores Endocrinos/química , Antagonistas de Estrógenos/farmacología , Antagonistas de Estrógenos/uso terapéutico , Terapia de Reemplazo de Estrógeno/efectos adversos , Estrógenos/administración & dosificación , Estrógenos/efectos adversos , Estrógenos/farmacología , Etinilestradiol/efectos adversos , Etinilestradiol/antagonistas & inhibidores , Etinilestradiol/farmacología , Femenino , Tamaño de los Órganos/efectos de los fármacos , Lesiones Precancerosas/metabolismo , Lesiones Precancerosas/patología , Lesiones Precancerosas/prevención & control , Distribución Aleatoria , Ratas , Receptores de Estrógenos/agonistas , Receptores de Estrógenos/antagonistas & inhibidores , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Triclosán/administración & dosificación , Triclosán/antagonistas & inhibidores , Útero/crecimiento & desarrollo , Útero/metabolismo , Útero/patología , Destete
9.
Clin Infect Dis ; 56(6): 790-7, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23223586

RESUMEN

BACKGROUND: Antimicrobial removal devices in blood culture media are designed to remove antibiotics from the blood culture solution, thereby facilitating bacterial growth. How well these devices function clinically has not been established. METHODS: All blood drawn for culture from adult inpatients and emergency department visitors in a level I trauma center was placed in paired BACTEC Plus and BacT/Alert FAN culture media and studied simultaneously, consecutively, and prospectively between 1 February and 30 September 2011. All cultures were processed per standard laboratory protocols. RESULTS: Of 9395 total cultures collected, 1219 (13%) were positive, 831 were included, and 524 (33%) contained pathogens. BACTEC had a 4.5-hour faster detection time (P < .0001), and isolated exclusively 182 of 524 (35%; P < .001) pathogens, 136 of 345 (39%) of the gram-positive cocci (P < .001), 48 of 175 (27%; P = .02) of the gram-negative rods, 101 of 195 (52%) of Staphylococcus aureus (P < .001), and 59 of 120 (49%; P = .004) septic events. If active antibiotics had been dosed 0-4 or 4-48 hours prior to culture collection, the odds of that culture growing in BACTEC were 4.8- and 5.2-fold greater, respectively, than of growing in BacT/Alert (P < .0001). Both were equivalent in the recovery of yeast and when no antimicrobials were dosed. CONCLUSIONS: BACTEC media has faster time to detection and increased bacterial recovery over the BacT/Alert media in the following categories: overall growth, pathogens, septic events, gram-positive cocci, gram-negative rods, Staphylococcus aureus, and cultures where antimicrobials were dosed up to 48 hours before culture collection.


Asunto(s)
Antibacterianos/antagonistas & inhibidores , Antibacterianos/uso terapéutico , Bacteriemia/diagnóstico , Bacterias/aislamiento & purificación , Técnicas Bacteriológicas/métodos , Medios de Cultivo/química , Adulto , Humanos , Sensibilidad y Especificidad , Factores de Tiempo
10.
Antimicrob Agents Chemother ; 56(11): 6048-50, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22948880

RESUMEN

Perturbation of hydroxyl radical accumulation by subinhibitory concentrations of 2,2'-bipyridyl plus thiourea protects Escherichia coli from being killed by 3 lethal antimicrobial classes. Here, we show that 2,2'-bipyridyl plus thiourea delays and/or reduces antimicrobial killing of Staphylococcus aureus by daptomycin, moxifloxacin, and oxacillin. While the protective effect of 2,2'-bipyridyl plus thiourea varied among strains and compounds, the data support the hypothesis that hydroxyl radical enhances antimicrobial lethality.


Asunto(s)
Antibacterianos/farmacología , Compuestos Aza/farmacología , Daptomicina/farmacología , Oxacilina/farmacología , Quinolinas/farmacología , Especies Reactivas de Oxígeno/metabolismo , Staphylococcus aureus/efectos de los fármacos , 2,2'-Dipiridil/farmacología , Antibacterianos/antagonistas & inhibidores , Compuestos Aza/antagonistas & inhibidores , Daptomicina/antagonistas & inhibidores , Fluoroquinolonas , Pruebas de Sensibilidad Microbiana , Moxifloxacino , Oxacilina/antagonistas & inhibidores , Quinolinas/antagonistas & inhibidores , Especies Reactivas de Oxígeno/antagonistas & inhibidores , Staphylococcus aureus/crecimiento & desarrollo , Tiourea/farmacología , Factores de Tiempo
11.
Indian J Med Res ; 136(2): 237-41, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22960890

RESUMEN

BACKGROUND & OBJECTIVES: AmpC ß-lactamases are clinically significant since these confer resistance to cephalosporins in the oxyimino group, 7-α methoxycephalosporins and are not affected by available ß-lactamase inhibitors. In this study we looked for both extended spectrum ß-lactamases (ESBL) and AmpC ß-lactamases in Klebsiella pneumoniae clinical isolates. METHODS: One hundred consecutive, non-duplicate clinical isolates of K. pneumoniae collected over a period of one year (June 2008 - June 2009) were included in the study. An antibiotic susceptibility method was used with 10 antibiotics for Gram-negative infections which helped in screening for ESBL and AmpC ß-lactamases and also in confirmation of ESBL production. The detection of AmpC ß-lactamases was done based on screening and confirmatory tests. For screening, disc diffusion zones of cefoxitin <18 mm was taken as cefoxitin resistant. All cefoxitin resistant isolates were tested further by AmpC disk test and modified three dimensional test. Multiplex-PCR was performed for screening the presence of plasmid-mediated AmpC genes. RESULTS: Of the 100 isolates of K. pneumoniae studied, 48 were resistant to cefoxitin on screening. AmpC disk test was positive in 32 (32%) isolates. This was also confirmed with modified three dimensional test. Indentation indicating strong AmpC producer was observed in 25 isolates whereas little distortion (weak AmpC) was observed in 7 isolates. ESBL detection was confirmed by a modification of double disk synergy test in 56 isolates. Cefepime was the best cephalosporin in synergy with tazobactam for detecting ESBL production in isolates co-producing AmpC ß-lactamases. The subsets of isolates phenotypically AmpC ß-lactamase positive were subjected to amplification of six different families of AmpC gene using multiplex PCR. The sequence analysis revealed 12 CMY-2 and eight DHA-1 types. INTERPRETATION & CONCLUSIONS: Tazobactam was the best ß-lactamase inhibitor for detecting ESBL in presence of AmpC ß-lactamase as this is a very poor inducer of AmpC gene. Amongst cephalosporins, cefepime was the best cephalosporin in detecting ESBL in presence of AmpC ß-lactamase as it is least hydrolyzed by AmpC enzymes. Cefepime-tazobactam combination disk test would be a simple and best method in detection of ESBLs in Enterobacteriaceae co-producing AmpC ß-lactamase in the routine diagnostic microbiology laboratories.


Asunto(s)
Proteínas Bacterianas , Cefalosporinas/administración & dosificación , Infección Hospitalaria , Klebsiella pneumoniae , beta-Lactamasas , Antibacterianos/administración & dosificación , Antibacterianos/antagonistas & inhibidores , Proteínas Bacterianas/antagonistas & inhibidores , Proteínas Bacterianas/aislamiento & purificación , Proteínas Bacterianas/metabolismo , Cefepima , Infección Hospitalaria/diagnóstico , Infección Hospitalaria/enzimología , Infección Hospitalaria/microbiología , Farmacorresistencia Bacteriana , Humanos , India , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/aislamiento & purificación , Klebsiella pneumoniae/patogenicidad , Pruebas de Sensibilidad Microbiana/métodos , Ácido Penicilánico/análogos & derivados , Tazobactam , Inhibidores de beta-Lactamasas , beta-Lactamasas/aislamiento & purificación , beta-Lactamasas/metabolismo
12.
Hear Res ; 294(1-2): 153-65, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22967486

RESUMEN

Loss of mechanosensory hair cells in the inner ear accounts for many hearing loss and balance disorders. Several beneficial pharmaceutical drugs cause hair cell death as a side effect. These include aminoglycoside antibiotics, such as neomycin, kanamycin and gentamicin, and several cancer chemotherapy drugs, such as cisplatin. Discovering new compounds that protect mammalian hair cells from toxic insults is experimentally difficult because of the inaccessibility of the inner ear. We used the zebrafish lateral line sensory system as an in vivo screening platform to survey a library of FDA-approved pharmaceuticals for compounds that protect hair cells from neomycin, gentamicin, kanamycin and cisplatin. Ten compounds were identified that provide protection from at least two of the four toxins. The resulting compounds fall into several drug classes, including serotonin and dopamine-modulating drugs, adrenergic receptor ligands, and estrogen receptor modulators. The protective compounds show different effects against the different toxins, supporting the idea that each toxin causes hair cell death by distinct, but partially overlapping, mechanisms. Furthermore, some compounds from the same drug classes had different protective properties, suggesting that they might not prevent hair cell death by their known target mechanisms. Some protective compounds blocked gentamicin uptake into hair cells, suggesting that they may block mechanotransduction or other routes of entry. The protective compounds identified in our screen will provide a starting point for studies in mammals as well as further research discovering the cellular signaling pathways that trigger hair cell death.


Asunto(s)
Aminoglicósidos/antagonistas & inhibidores , Cisplatino/antagonistas & inhibidores , Células Ciliadas Auditivas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Aminoglicósidos/toxicidad , Animales , Antibacterianos/antagonistas & inhibidores , Antibacterianos/toxicidad , Antineoplásicos/antagonistas & inhibidores , Antineoplásicos/toxicidad , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Cisplatino/toxicidad , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Interacciones Farmacológicas , Gentamicinas/antagonistas & inhibidores , Gentamicinas/toxicidad , Células Ciliadas Auditivas/patología , Humanos , Kanamicina/antagonistas & inhibidores , Kanamicina/toxicidad , Sistema de la Línea Lateral/efectos de los fármacos , Sistema de la Línea Lateral/patología , Mecanotransducción Celular/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Neomicina/antagonistas & inhibidores , Neomicina/toxicidad , Moduladores Selectivos de los Receptores de Estrógeno/farmacología , Pez Cebra
13.
J Endod ; 38(9): 1275-8, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22892750

RESUMEN

INTRODUCTION: Newer antibacterial alternatives such as chitosan nanoparticles (CSnps) and photodynamic therapy (PDT) have been investigated to achieve effective root canal disinfection. The current study aims to assess the effect of various tissue inhibitors such as dentin, dentin matrix, pulp tissue, bacterial lipopolysaccharides (LPSs), and bovine serum albumin (BSA) on the antibacterial activity of CSnps and PDT. METHODS: The antibacterial effect of CSnps and PDT using photosensitizers, rose bengal (RB), and methylene blue (MB) were tested on planktonic Enterococcus faecalis American Type Culture Collection 29212 with or without pretreatment using different tissue inhibitors for an hour. Bacterial survival was assessed after 1, 8, and 24 hours of incubation with CSnps and after PDT using RB and MB. RESULTS: Pulp and BSA inhibited the antibacterial effect of CSnps significantly (P < .05). The antibacterial effect of CSnps was not affected by dentin, dentin matrix, or LPSs. The antibacterial activity of PDT using MB and RB was inhibited in a decreasing order by dentin matrix, BSA, pulp, dentin, and LPSs (P < .05). The effect of tissue inhibitors was higher in the case of PDT with RB. Depending on the antibacterial mechanism of CSnps and PDT, different inhibitory patterns were observed with different tissue inhibitors. CONCLUSIONS: The tissue inhibitors existing within the root canal affected the antibacterial activity of CSnps and PDT at varying degrees. Further research is required to enhance their antimicrobial efficacy in an endodontic environment.


Asunto(s)
Antibacterianos/farmacología , Materiales Biocompatibles/farmacología , Quitosano/farmacología , Enterococcus faecalis/efectos de los fármacos , Nanopartículas , Fotoquimioterapia/métodos , Animales , Antibacterianos/antagonistas & inhibidores , Bovinos , Quitosano/antagonistas & inhibidores , Pulpa Dental/fisiología , Dentina/fisiología , Escherichia coli , Proteínas de la Matriz Extracelular/farmacología , Humanos , Lipopolisacáridos/farmacología , Azul de Metileno/farmacología , Viabilidad Microbiana/efectos de los fármacos , Fármacos Fotosensibilizantes/farmacología , Rosa Bengala/farmacología , Albúmina Sérica/farmacología , Temperatura , Factores de Tiempo
14.
Chemosphere ; 89(5): 563-8, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22717161

RESUMEN

Pollution by heavy metals has become one of the most important problems in marine coastal areas as a consequence of anthropogenic inputs. Among metal contaminants, zinc, being considered not very toxic, is sometimes released into the sea in appreciable quantities and its concentration is loosely regulated. In this work we analyzed the effects of a high zinc concentration on the sea urchin Paracentrotus lividus immune system. In particular, after 24 h of zinc treatment, we evaluated coelomocytes morphology and composition as well as the zinc influence on some humoral parameters such as hemolysis, lysozyme-like activity and antibacterial activity on Vibrio alginolyticus. Our results evidenced that the presence of zinc affected both cellular and acellular components of the sea urchin immune system. The P. lividus coelomocytes changed in morphology and number; moreover, the amebocytes changed from a petaloid to a filipodial-like shape and the red spherula cells increased in number. Among the considered humoral effectors lysozyme-like activity and antibacterial activity on V. alginolyticus decreased in short-term to zinc treatment. The modifications in the sea urchin immunological competence might give an early indication of disease susceptibility thus suggesting to consider the examined defence mechanisms as potential biological indicators of metal pollution.


Asunto(s)
Inmunocompetencia/efectos de los fármacos , Erizos de Mar/efectos de los fármacos , Erizos de Mar/inmunología , Contaminantes Químicos del Agua/toxicidad , Zinc/toxicidad , Animales , Antibacterianos/antagonistas & inhibidores , Antibacterianos/farmacología , Susceptibilidad a Enfermedades/inmunología , Hemólisis/efectos de los fármacos , Muramidasa/metabolismo , Erizos de Mar/citología , Erizos de Mar/embriología , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/inmunología , Vibrio alginolyticus/efectos de los fármacos
15.
J Antimicrob Chemother ; 67(9): 2143-51, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22615298

RESUMEN

OBJECTIVES: Polyanionic polymers, including lipoteichoic acid and wall teichoic acid, are important determinants of the charged character of the staphylococcal cell wall. This study was designed to investigate the extent to which teichoic acid contributes to protection from anionic azo dyes and to identify barriers to drug penetration for development of new antibiotics for multidrug-resistant Staphylococcus aureus infection. METHODS: We studied antimicrobial activity of azo dyes against S. aureus strains with or without inhibition of teichoic acid in vitro and in vivo. RESULTS: We observed that inhibition of wall teichoic acid expression resulted in an ∼1000-fold increase in susceptibility to azo dyes such as Congo red, reducing its MIC from >1024 to <4 mg/L. Sensitization occurred when the first step in the wall teichoic acid pathway, catalysed by TarO, was inhibited either by mutation or by chemical inhibition. In contrast, genetic blockade of lipoteichoic acid biosynthesis did not confer Congo red susceptibility. Based on this finding, combination therapy was tested using the highly synergistic combination of Congo red plus tunicamycin at sub-MIC concentrations (to inhibit wall teichoic acid biosynthesis). The combination rescued Caenorhabditis elegans from a lethal challenge of S. aureus. CONCLUSIONS: Our studies show that wall teichoic acid confers protection to S. aureus from anionic azo dyes and related compounds, and its inhibition raises the prospect of development of new combination therapies based on this inhibition.


Asunto(s)
Antibacterianos/antagonistas & inhibidores , Compuestos Azo/antagonistas & inhibidores , Pared Celular/química , Pared Celular/efectos de los fármacos , Staphylococcus aureus/química , Staphylococcus aureus/efectos de los fármacos , Ácidos Teicoicos/metabolismo , Antibacterianos/metabolismo , Antibacterianos/toxicidad , Compuestos Azo/metabolismo , Compuestos Azo/toxicidad , Rojo Congo/metabolismo , Rojo Congo/toxicidad , Humanos , Pruebas de Sensibilidad Microbiana
16.
Ann Biol Clin (Paris) ; 70(2): 117-40, 2012.
Artículo en Francés | MEDLINE | ID: mdl-22484524

RESUMEN

Since 1980, the prescription of new semi-synthetic molecules of third generation cephalosporins changed the course of modern medicine. However, the acquired resistance against these antibiotics was rapidly developed with the production of extended spectrum ß-lactamases (ESBL) (TEM and SHV types) disseminated mainly by nosocomial Klebsiella pneumoniae clones. Since around 2000, we are facing a watershed in ESBL epidemiology because of the widespread of the CTX-M enzymes among Escherichia coli isolates in community as well as in hospitals. The dissemination of these new ESBL in community within a commensal bacterium is a threat for the public health. The risk is to be in front of an uncontrollable resistance existing everywhere. It is the purpose of this review to focus, in particular, on the changing epidemiology and the spread of ESBL(s) and to provide updated data on definition, classification and laboratory detection of ESBL(s) that will help to control this resistance.


Asunto(s)
Antibacterianos/clasificación , Farmacorresistencia Bacteriana Múltiple/genética , beta-Lactamasas/fisiología , Antibacterianos/antagonistas & inhibidores , Antibacterianos/metabolismo , Técnicas de Tipificación Bacteriana , Enterobacter/clasificación , Enterobacter/enzimología , Enterobacter/genética , Infecciones por Enterobacteriaceae/epidemiología , Infecciones por Enterobacteriaceae/microbiología , Geografía , Humanos , Infecciones por Klebsiella/diagnóstico , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/genética , Pruebas de Sensibilidad Microbiana/métodos , Técnicas de Diagnóstico Molecular , Polimorfismo Genético/fisiología , beta-Lactamasas/clasificación , beta-Lactamasas/genética , beta-Lactamasas/metabolismo
17.
Eur J Oral Sci ; 120(2): 132-9, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22409219

RESUMEN

Green tea is a popular drink throughout the world, and it contains various components, including the green tea polyphenol (-)-epigallocatechin gallate (EGCG). Tea interacts with saliva upon entering the mouth, so the interaction between saliva and EGCG interested us, especially with respect to EGCG-protein binding. SDS-PAGE revealed that several salivary proteins were precipitated after adding EGCG to saliva. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) peptide mass fingerprinting indicated that the major proteins precipitated by EGCG were alpha-amylase, S100, and cystatins. Surface plasmon resonance revealed that EGCG bound to alpha-amylase at dissociation constant (K(d)) = 2.74 × 10(-6) M, suggesting that EGCG interacts with salivary proteins with a relatively strong affinity. In addition, EGCG inhibited the activity of alpha-amylase by non-competitive inhibition, indicating that EGCG is effective at inhibiting the formation of fermentable carbohydrates involved in caries formation. Interestingly, alpha-amylase reduced the antimicrobial activity of EGCG against the periodontal bacterium Aggregatibacter actinomycetemcomitans. Therefore, we considered that EGCG-salivary protein interactions might have both protective and detrimental effects with respect to oral health.


Asunto(s)
Catequina/análogos & derivados , Caries Dental/prevención & control , Proteínas y Péptidos Salivales/metabolismo , , alfa-Amilasas/análisis , Adulto , Aggregatibacter actinomycetemcomitans/efectos de los fármacos , Antibacterianos/antagonistas & inhibidores , Catequina/metabolismo , Catequina/farmacología , Cistatinas/antagonistas & inhibidores , Carbohidratos de la Dieta/antagonistas & inhibidores , Femenino , Humanos , Masculino , Persona de Mediana Edad , Unión Proteica , Proteoma/análisis , Saliva/enzimología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Té/química , Adulto Joven , alfa-Amilasas/antagonistas & inhibidores
18.
Arch. Soc. Esp. Oftalmol ; 87(3): 72-78, mar. 2012. tab, graf
Artículo en Español | IBECS | ID: ibc-101338

RESUMEN

Objetivo: Determinar la susceptibilidad antibiótica de la bacterias obtenidas en cultivos de infecciones oculares en la Fundación Oftalmológica de Santander - Clínica Carlos Ardila Lulle (FOSCAL). Materiales y métodos: Estudio descriptivo retrospectivo de una serie de registros de cultivos de muestras de superficie ocular y líquidos intraoculares del laboratorio OCULAB-FOSCAL en Floridablanca (Colombia) realizados entre enero y diciembre de 2007. Se realizó antibiograma por el método de Kirby-Bauer con sensi-discos impregnados de concentraciones determinadas de antibiótico. Resultados: Se recogieron un total de 352 muestras de los cuales 160 fueron de conjuntiva, 150 fueron de córnea y 42 de líquidos intraoculares. Se recuperó más de un microorganismo en el 45,65% del total de las muestras. El 78,7 y el 18,4% de las bacterias identificadas correspondieron a Gram positivos y a Gram negativos, respectivamente. El 6,3, 8,9, 33,2 y 35,6% de las bacterias Gram positivas fueron resistentes a gatifloxacino, moxifloxacino, ciprofloxacino y levofloxacino, respectivamente. El 7,4, 16,7, 16,7 y 25,9% de las bacterias Gram negativas fueron resistentes a gatifloxacino, moxifloxacino, ciprofloxacino y levofloxacino, respectivamente. La resistencia bacteriana global (tanto Gram positivos como Gram negativos) a moxifloxacino fue del 10,15% y a gatifloxacino del 6,46%, siendo esta diferencia estadísticamente significativa (p<0,05)(AU)


Conclusiones: En nuestro estudio, se evidenció el desarrollo de resistencia bacteriana en muestras oculares incluso con las fluoroquinolonas de cuarta generación. Sin embargo se encontraron menores niveles de resistencia para las fluoroquinolonas de cuarta generación que para las de tercera y segunda generación, especialmente entre Gram positivos. Gatifloxacino mostró menores niveles de resistencia que la moxifloxacino. La interpretación de esta superioridad debe, sin embargo, hacerse con cuidado en el campo clínico, ya que se deben tener en cuenta otros factores como la penetración tisular y la actividad in vivo(AU)


Objective: To determine the antibiotic susceptibility of bacteria recovered from cultures of ocular infections in the Fundación Oftalmológica de Santander - Clínica Carlos Ardila Lulle (FOSCAL). Materials and methods: Retrospective descriptive study of a series of registries of cultures of samples from ocular surfaces and intraocular fluids from the OCULAB-FOSCAL laboratory in Floridablanca (Colombia) made between January and December of 2007. Antibiotic sensitivity screening by the method of Kirby-Bauer with impregnated Sensi-Discs™ of determined antibiotic concentrations was performed. Results: A total of 352 samples were studied: 160 from conjunctiva, 150 from cornea and 42 from intraocular fluids. Of the total of the samples more than one microorganism was recovered 45.65% of the samples. Gram positive and Gram negative bacteria were identified in 78.7 and 18.4%, respectively. Resistance to gatifloxacin, moxifloxacin, ciprofloxacin and levofloxacin was observed in 6.3, 8.9, 33.2 and 35.6%, respectively, of Gram positive bacteria. Resistance to gatifloxacin, moxifloxacin, ciprofloxacin and levofloxacin was also observed in 7.4, 16.7, 16.7%and 25.9%, respectively, of Gram negative bacteria. The overall bacterial resistance (Gram positive and Gram negative) to moxifloxacin was 10.15%, and to gatifloxacin it was 6.46%, being which showed a statistically significant difference (P<.05). Conclusions: In our study the development of bacterial resistance to fourth generation fluoroquinolones was demonstrated in ocular samples. However, lower levels of resistance to fourth generation fluoroquinolones compared with that of third and second generation were found, particularly to Gram positive. Gatifloxacin showed lower resistance levels than moxifloxacin. Nevertheless, interpretation of this superiority must be made with caution in the clinical field, since other factors, like tissue penetration and in vivo activity, must be taken into account(AU)


Asunto(s)
Humanos , Antibacterianos/uso terapéutico , Bacterias , Antibacterianos/antagonistas & inhibidores , Oftalmopatías/microbiología , Oftalmopatías/terapia , Pruebas de Sensibilidad Microbiana/clasificación , Antibacterianos/administración & dosificación , Antibacterianos/análisis , Antibacterianos/farmacología , Bacterias/clasificación , Bacterias/patogenicidad , Medios de Cultivo/análisis , Medios de Cultivo/clasificación , Medios de Cultivo/farmacología , Medios de Cultivo/farmacocinética , Pruebas de Sensibilidad Microbiana/estadística & datos numéricos
19.
Curr Microbiol ; 64(5): 457-62, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22349957

RESUMEN

In the present study, we investigated the possible involvement of oxidative stress in ciprofloxacin-induced cytotoxicity against several reference bacteria including Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, and clinical isolate of methicillin-resistant Staphylococcus aureus (MRSA). Oxidative stress was assessed by measurement of hydrogen peroxide generation using a FACScan flow cytometer. The antibacterial activity of ciprofloxacin was assessed using the disk diffusion method and by measuring the minimum inhibitory concentration (MIC). Ciprofloxacin induced a dose-dependent antibacterial activity against all bacteria where the highest tested concentration was 100 ug/ml. Results revealed that E. coli cells were highly sensitive to ciprofloxacin (MIC = 0.21 µg/mL ± 0.087), P. aeruginosa and S. aureus cells were intermediately sensitive (MIC = 5.40 µg/mL ± 0.14; MIC = 3.42 µg/mL ± 0.377, respectively), and MRSA cells were highly resistant (MIC = 16.76 µg/mL ± 2.1). Pretreatment of E. coli cells with either vitamin E or vitamin C has significantly protected cells against ciprofloxacin-induced cytotoxicity. These results indicate the possible antagonistic properties for vitamins C or E when they are used concurrently with ciprofloxacin.


Asunto(s)
Antibacterianos/antagonistas & inhibidores , Ácido Ascórbico/farmacología , Bacterias/efectos de los fármacos , Infecciones Bacterianas/microbiología , Ciprofloxacina/antagonistas & inhibidores , Vitamina E/farmacología , Antibacterianos/farmacología , Ácido Ascórbico/antagonistas & inhibidores , Bacterias/aislamiento & purificación , Ciprofloxacina/farmacología , Antagonismo de Drogas , Humanos , Pruebas de Sensibilidad Microbiana , Vitamina E/antagonistas & inhibidores
20.
Cardiovasc Toxicol ; 12(1): 1-9, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21938493

RESUMEN

Probenecid was initially developed with the goal of reducing the renal excretion of antibiotics, specifically penicillin. It is still used for its uricosuric properties in the treatment in gout, but its clinical relevance has sharply fallen and is rarely used today for either. Interestingly, throughout the last 60 years, there have been a host of apparently unrelated studies using probenecid in the clinical and basic research arena, including its potential use in the diagnosis and treatment of depression and its use to prevent fura-2 leakage in calcium transient studies. Recently, it has been shown that it is also an agonist of the Transient Receptor Potential Vanilloid 2 channel. Due to its unique action and new findings implicating TRPV channels in physiology and in disease, probenecid may have a new future as a research tool, and perhaps as a clinical agent in the neurology and cardiology fields. We review the history of probenecid in this paper and its potential future uses.


Asunto(s)
Probenecid/farmacocinética , Probenecid/uso terapéutico , Uricosúricos/farmacocinética , Uricosúricos/uso terapéutico , Animales , Antibacterianos/antagonistas & inhibidores , Antibacterianos/farmacocinética , Depresión/tratamiento farmacológico , Depresión/metabolismo , Fura-2/metabolismo , Gota/tratamiento farmacológico , Gota/metabolismo , Humanos , Probenecid/química , Canales Catiónicos TRPV/fisiología , Uricosúricos/química
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