RESUMEN
The discovery of Streptomyces-produced streptomycin founded the age of tuberculosis therapy. Despite the subsequent development of a curative regimen for this disease, tuberculosis remains a worldwide problem, and the emergence of multidrug-resistant Mycobacterium tuberculosis has prioritized the need for new drugs. Here we show that new optimized derivatives from Streptomyces-derived griselimycin are highly active against M. tuberculosis, both in vitro and in vivo, by inhibiting the DNA polymerase sliding clamp DnaN. We discovered that resistance to griselimycins, occurring at very low frequency, is associated with amplification of a chromosomal segment containing dnaN, as well as the ori site. Our results demonstrate that griselimycins have high translational potential for tuberculosis treatment, validate DnaN as an antimicrobial target, and capture the process of antibiotic pressure-induced gene amplification.
Asunto(s)
Antituberculosos/farmacología , Proteínas Bacterianas/antagonistas & inhibidores , Terapia Molecular Dirigida , Mycobacterium tuberculosis/efectos de los fármacos , Péptidos Cíclicos/farmacología , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Animales , Antituberculosos/química , Antituberculosos/uso terapéutico , Línea Celular Tumoral , Cristalografía por Rayos X , ADN Polimerasa Dirigida por ADN , Modelos Animales de Enfermedad , Diseño de Fármacos , Humanos , Ratones , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Mycobacterium smegmatis/efectos de los fármacos , Mycobacterium smegmatis/enzimología , Mycobacterium tuberculosis/enzimología , Péptidos Cíclicos/química , Péptidos Cíclicos/uso terapéutico , Estructura Secundaria de Proteína , Streptomyces/química , Streptomyces/efectos de los fármacos , Streptomyces/metabolismo , Tuberculosis Resistente a Múltiples Medicamentos/microbiologíaRESUMEN
PURPOSE: The aim of this study was to evaluate the 6-month effect of a single automated thermodynamic treatment (LipiFlow) and implications of meibomian gland atrophy on treatment efficacy 6 months after application. METHODS: We analyzed the data of 26 subjects with meibomian gland dysfunction before and 6 months after treatment. Investigated parameters included subjective symptoms, lipid layer thickness, meibomian gland assessment, tear osmolarity, corneal and conjunctival staining, lid margin parallel conjunctival folds, Schirmer test values, bulbar redness, tear meniscus height, meibomian gland atrophy, and noninvasive tear break-up time. RESULTS: Subjective symptoms (mean Ocular Surface Disease Index, 42 ± 19 to 33 ± 21; P = 0.004, mean Standard Patient Evaluation of Eye Dryness 16 ± 7 to 12 ± 7; P = 0.0001), lipid layer thickness (44.0 ± 15.6 to 51.3 ± 20.4; P = 0.014), number of expressible glands (2.9 ± 1.6 to 6.4 ± 4.6; P < 0.0001), lid margin parallel conjunctival folds (2.3 ± 1.0 to 2.0 ± 0.9; P = 0.04), and bulbar redness (1.4 ± 0.5 to 1.2 ± 0.5; P = 0.0001) were all improved 6 months after treatment. Symptomatic improvement was higher in patients with less severe meibomian gland atrophy compared with patients with more dropout at treatment. There was no change of meibomian gland atrophy 6 months after treatment. CONCLUSIONS: In summary, the results showed that a single thermodynamic treatment is effective in the treatment of meibomian gland dysfunction and that the effects last for at least 6 months. We suggest performing meibography in every patient before treatment for better prediction of therapeutic effects.
Asunto(s)
Síndromes de Ojo Seco/terapia , Enfermedades de los Párpados/terapia , Hipertermia Inducida/métodos , Glándulas Tarsales , Adulto , Anciano , Atrofia , Estudios Cruzados , Método Doble Ciego , Síndromes de Ojo Seco/fisiopatología , Enfermedades de los Párpados/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Lípidos/análisis , Masculino , Glándulas Tarsales/diagnóstico por imagen , Glándulas Tarsales/patología , Persona de Mediana Edad , Concentración Osmolar , Radiografía , Lágrimas/química , Lágrimas/fisiologíaRESUMEN
PURPOSE: To compare the effectiveness of a single LipiFlow(®) treatment with combined lid warming and massage in patients with meibomian gland dysfunction (MGD). METHODS: In this prospective, randomized, crossover, observer-masked clinical trial, subjects were randomized to receive either a single 12-min LipiFlow-LipiFlow Thermal Pulsation (LTP) system treatment or to perform combined twice-daily lid warming and massage for 3 months. All subjects were examined before, and 1 and 3 months after initiation of treatments. Investigated parameters included subjective symptoms, lipid layer thickness, meibomian gland assessment, tear break-up time, tear osmolarity, corneal and conjunctival staining, Schirmer test values, and tear meniscus height. RESULTS: A total of 31 subjects completed the 3-month follow-up. At 1 and 3 months, patients in the LipiFlow treatment group had a significant reduction in Ocular Surface Disease Index (OSDI) scores compared with those in the lid-margin hygiene group. Both treatments produced a significant improvement in expressible meibomian glands compared to the baseline parameters, but no significant difference was noted between the two groups. The other investigated objective parameters did not show a significant difference. CONCLUSION: Results of our study show that a single LipiFlow treatment is as least as effective as a 3-month, twice-daily lid margin hygiene regimen for MGD. However, the present study was observer-masked only, and therefore a placebo effect may have confounded any improvements in subjective symptoms and other parameters in both groups.
Asunto(s)
Síndromes de Ojo Seco/terapia , Enfermedades de los Párpados/terapia , Hipertermia Inducida/métodos , Masaje/métodos , Glándulas Tarsales/fisiopatología , Adulto , Anciano , Estudios Cruzados , Síndromes de Ojo Seco/fisiopatología , Enfermedades de los Párpados/fisiopatología , Párpados/fisiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Método Simple Ciego , Lágrimas/fisiología , Resultado del Tratamiento , Adulto JovenRESUMEN
OBJECTIVE: Although an increased distractibility is one of the behavioral criteria of Attention Deficit Hyperactivity Disorder (ADHD), there is little empirical evidence that children with ADHD are in fact more distractible than their normal peers. METHODS: We recorded event-related potentials (ERPs) to distracting novel sounds (novels) and standard sounds, (standards) while children performed a visual two-choice reaction time task. Twenty-five children with ADHD were compared with eighteen normal controls (aged 8-12 years). RESULTS: Children with ADHD showed a larger early P3a (150-250 ms), both in response to the standard and in response to the novel. The late phase of the P3a had a larger amplitude in the ADHD group in the 250-300 ms window compared to the control group, which was only present in response to the novel. Interestingly, the novel reduced the errors of omission in the ADHD group to a greater extent than in the normal control group. CONCLUSIONS: Although children with ADHD show an increased orienting response to novels, this distracting information can enhance their performance temporarily, possibly by increasing their arousal to an optimal level, as indicated by the reduced omission rate. SIGNIFICANCE: These data indicate that distraction is not always distracting in children with ADHD and that distraction can also have beneficial effects.