Eye drop Self-medication: Comparative Questionnaire-based study of two Latin American cities.

A broad spectrum of ocular symptoms are treated by self-medication with commercial eye-drops.  This behavior threatens individuals' visual health. In Latin America, evidence is poor. Objective:  To  detect,  characterize  and  compare  patterns  of  ophthalmic  self-medication  between  Córdoba (Argentina) and Barranquilla (Colombia).Design:  Analytic, cross-sectional and comparative population-based study. Setting: Two private tertiary care ophthalmology centers from Córdoba, Argentina, and Barranquilla, Colombia.Participants:  Patients 18 years of age or older who consulted for the first time in this two institutions duringAugust-November 2009, were included. A number of 570 patients were enrrolled.Methods:  Data collected through a semi-structured questionnaire. Main outcome measure: To determine thefrequency of self-medication with eyedrops on a specific population of two cities in Latin America.Results:  Comparable  rates  of  ocular  self-medication  were  found  (25.6%  and  25.7%  for  Cordoba  and Barranquilla, respectively). The percentage of men and women who self-medicated was not significantly different between both samples. The major source of eye drops recommendation in the Argentineans patients was the pharmacist (31%); while the social source was predominant in Colombian individuals (53%). In Cordoba, the most frequently used product was a non-steroidal anti-inflammatory drop in combination with a vasoconstrictive agent (32%); while in Barranquilla, antibiotic eye drops were preferred (33%). Self-medication was higher between the ages of 31 and 50 years old in Argentinean citizens (28%) and between 18 to 31 years old in the Colombiancommunity (39%). This habit was found mostly in patients who completed university studies in Cordoba (33%); in Barranquilla, individuals with lower educational level practice more this behavior (36%).Conclusion:  In both populations, patients commonly treat ocular conditions by self-medicating. Currently, anincreasing number of eye drops are obtainable without prescription and a high percentage of self-medicated patients in both samples ignore the possible side effects of the used medication.Fil: Marquez, Gabriel. Fundación VER; ArgentinaFil: Hildegard Piñeros-Heilbron. Fundación Oftalmológica del Caribe; ColombiaFil: Sanchez, Victoria M.. Fundación VER; ArgentinaFil: Torres, Victor Eduardo Roque. Fundación VER; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad. Universidad Nacional de Córdoba. Centro de Investigaciones y Estudios sobre Cultura y Sociedad; ArgentinaFil: Gramajo, Ana L.. Fundación VER; ArgentinaFil: Juarez, Claudio P.. Fundación VER; Argentina. Fundación Oftalmológica del Caribe; ColombiaFil: Peña, Fernando. Fundación Oftalmológica del Caribe; ColombiaFil: Luna, José D.. Fundación VER; Argentin

Delayed Corneal Epithelial Healing after Intravitreal Bevacizumab: A Clinical and Experimental Study

Purpose: To report corneal epithelial defects (CEDs) and delayed epithelial healing after intravitreal bevacizumab (IVB) injection and to describe delayed corneal epithelial healing with topical administration of bevacizumab in an experimental rabbit model. Methods: A retrospective chart review was performed on 850 eyes of 850 patients with neovascular eye disease and diabetic macular edema who had received 1.25 to 2.5 mg IVB. In the experimental arm of the study, photorefractive keratectomy was used to create a 3 mm CED in the right eyes of 18 New Zealand rabbits which were then randomized to three equal groups. All rabbits received topical antibiotics, additionally those in group A received topical bevacizumab and animals in group B were treated with topical corticosteroids. The rate of epithelial healing was assessed at different time points using slitlamp photography. Results: In the clinical study, seven eyes of seven subjects developed CEDs the day after IVB injection. All of these eyes had preexisting corneal edema. The healing period ranged from 3 to 38 days (average 11 days) despite appropriate medical management. In the experimental study, topical bevacizumab and corticosteroids both significantly hindered corneal epithelial healing at 12 and 24 hours. Conclusion: Bevacizumab was demonstrated to cause CEDs in clinical settings. Moreover, corneal epithelial healing was delayed by topical application of bevacizumab, in the experimental model. These short-term results suggest that corneal edema may be considered as a risk factor for epithelial defects after IVB

Memantine, Simvastatin, and Epicatechin Inhibit 7-Ketocholesterol-induced Apoptosis in Retinal Pigment Epithelial Cells But Not Neurosensory Retinal Cells In Vitro

Purpose: 7-ketocholesterol (7kCh), a natural byproduct of oxidation in lipoprotein deposits, is implicated in the pathogenesis of diabetic retinopathy and age-related macular degeneration (AMD). This study was performed to investigate whether several clinical drugs can inhibit 7kCh-induced caspase activation and mitigate its apoptotic effects on retinal cells in vitro. Method: Two populations of retinal cells, human retinal pigment epithelial cells (ARPE-19) and rat neuroretinal cells (R28), were exposed to 7kCh in the presence of the following inhibitors: Z-VAD-FMK (pan-caspase inhibitor), simvastatin, memantine, epicatechin, and Z-IETD-FMK (caspase-8 inhibitor) or Z-ATAD-FMK (caspase-12 inhibitor). Caspase-3/7, -8, and -12 activity levels were measured by fluorochrome caspase assays to quantify cell death. IncuCyte live-cell microscopic images were obtained to quantify cell counts. Results: Exposure to 7kCh for 24 hours significantly increased caspase activities for both ARPE-19 and R28 cells (P < 0.05). In ARPE cells, pretreatment with various drugs had significantly lower caspase-3/7, -8, and -12 activities, reported in % change in mean signal intensity (msi): Z-VAD-FMK (48% decrease, P < 0.01), memantine (decreased 47.8% at 1 μM, P = 0.0039 and 81.9% at 1 mM, P < 0.001), simvastatin (decreased 85.3% at 0.01 μM, P < 0.001 and 84.8% at 0.05 μM , P < 0.001) or epicatechin (83.6% decrease, P < 0.05), Z-IETD-FMK (68.1% decrease, P < 0.01), and Z-ATAD-FMK (47.7% decrease, P = 0.0017). In contrast, R28 cells exposed to 7kCh continued to have elevated caspase- 3/7, -8, and -12 activities (between 25.7% decrease and 17.5% increase in msi, P > 0.05) regardless of the pretreatment. Conclusion: Several current drugs protect ARPE-19 cells but not R28 cells from 7kChinduced apoptosis, suggesting that a multiple-drug approach is needed to protect both cells types in various retinal diseases

Novel Two-Component Systems Implied in Antibiotic Production in Streptomyces coelicolor

The abundance of two-component systems (TCSs) in Streptomyces coelicolor A3(2) genome indicates their importance in the physiology of this soil bacteria. Currently, several TCSs have been related to antibiotic regulation, and the purpose in this study was the characterization of five TCSs, selected by sequence homology with the well-known absA1A2 system, that could also be associated with this important process. Null mutants of the five TCSs were obtained and two mutants (ΔSCO1744/1745 and ΔSCO4596/4597/4598) showed significant differences in both antibiotic production and morphological differentiation, and have been renamed as abr (antibiotic regulator). No detectable changes in antibiotic production were found in the mutants in the systems that include the ORFs SCO3638/3639, SCO3640/3641 and SCO2165/2166 in any of the culture conditions assayed. The system SCO1744/1745 (AbrA1/A2) was involved in negative regulation of antibiotic production, and acted also as a negative regulator of the morphological differentiation. By contrast, the system SCO4596/4597/4598 (AbrC1/C2/C3), composed of two histidine kinases and one response regulator, had positive effects on both morphological development and antibiotic production. Microarray analyses of the ΔabrC1/C2/C3 and wild-type transcriptomes revealed downregulation of actII-ORF4 and cdaR genes, the actinorhodin and calcium-dependent antibiotic pathway-specific regulators respectively. These results demonstrated the involvement of these new two-component systems in antibiotic production and morphological differentiation by different approaches. One is a pleiotropic negative regulator: abrA1/A2. The other one is a positive regulator composed of three elements, two histidine kinases and one response regulator: abrC1/C2/C3

Interferometría Landau-Zener-Stuckelberg en qubits superconductores : efectos del acoplamiento sistema-reservorio.

En 1982 los físicos Paul Benio y Richard Feymann (independientemente) propusieron por primera vez la idea de que un sistema cuántico puede ser utilizado en computación. Ambas ideas se basan en que si la unidad indivisible de información clasica es el bit (un objeto que puede tener dos valores 0 o 1) entonces la correspondiente unidad de información cuántica es el bit cuántico o "quantum bit" ( 'qubit'). Con lo cual la idea basica de funcionamiento es: se coloca una serie de qubits en un estado inicial determinado, se aplica una operación unitaria U (equivalente a una compuerta lógica cuántica), se deja evolucionar al sistema y luego se mide. La medición realizada es la salida de la computadora cuántica. A partir de estas ideas sugieron diversos candidatos para ser usados como qubits para: almacenamiento, manipulación y transmisión de información cuántica. Paralelamente, el estudio de fenomenos cuánticos a escala mascroscópica y los desarrollos tecnológicos permitieron el uso de nanosistemas superconductores como qubits. En los cuales es posible manipular el estado cuántico del sistema mediante la aplicación y medición de variables mascroscópicas (como voltajes, corrientes y flujos magnéticos en el dispositivo), útil para la construcción de una compuerta lógica cuántica. Entre los posibles candidatos superconductores tenemos el qubit de flujo. Este dispositivo consiste en una espira superconductora con una serie de junturas del tipo superconductor-aislante-superconductor. El funcionamiento se basa, sin entrar en detalles, en la posibilidad de manipular el estado cuántico superconductor mediante la aplicación de un campo magnetico externo: el flujo encerrado en la espira modica las fases de la función de onda del sistema, generando fenómenos de interferencia cuántica. Una de las grandes ventajas es la posibilidad de determinar su estado cuántico mediante la medición de la corriente en la espira: los signos de la corriente permite identicar los estados del sistema. En este trabajo se presenta una breve descripción de dichos nanosistemas a fin de determinar su dinámica. Partimos modelando al qubit de flujo como un sistema simplicado de dos niveles, forzado por un campo magnético periódico en el tiempo. De esta manera se manipula el estado del qubit modicando las probabilidades de encontrar al sistema en uno de los dos estados, es decir: se elige un estado inicial, se aplica el campo externo y se analiza su evolución. En base a este modelo, calculamos numericamente dichas probabilidades para tiempos finitos y para el caso estacionario, en el cual se deja evolucionar al sistema lo suciente hasta alcanzar un estado final independientemente de su preparación inicial. Por otra parte se enfatizó el estudio del qubit de flujo en contacto con el ambiente que lo rodea, con el objetivo de poder comparar nuestros resultados numéricos con mediciones experimentales. Para ello se analiza como afectan las fluctuaciones del mundo externo a la dinámica del sistema, considerando diferentes fuentes de ruido. Luego se estudio los efectos de extender el sistema a N niveles, en particular se trabaj o con N = 4. De esta manera, se busca poder identicar las fuentes de ruido para poder disminuirlas, y con ello evitar la pérdida de información del sistema

Interferometría Landau-Zener-Stuckelberg en qubits superconductores : modelado de sistemas fuera del equilibrio, entrelazamiento cuántico, y simuladores cuánticos

En la presente tesis, estudiamos la dinámica de qubits superconductores (SC) en presencia de campos armónicos fuertes, centrándonos principalmente en el análisis de los efectos del ruido, la generación de entrelazamiento, y su aplicación como simuladores cuánticos. En primer lugar, consideramos los efectos del ruido ambiente y analizamos su comportamiento a diferentes escalas de tiempo. En este contexto, usamos la ecuación maestra en la aproximación de Floquet-Markov para el análisis de la interformetría Landau-Zener-Stuckelberg calculada a tiempo finito. Se encontró que la presencia de resonancias multifotónicas simétricas y antisimétricas en el estado estacionario revela la naturaleza del ruido. Adicionalmente, analizamos la posibilidad de manipular entrelazamiento a través de campos periódicos externos para los casos de disipación despreciable y en presencia de un reservorio térmico. Para el caso de entrelazamiento de un sistema de dos qubits acoplados y controlados por un flujo ac-magnético externo, se presentan extensivos resultados numéricos y analíticos, usándose la concurrencia como medida de entrelazamiento. De esta manera, se estudió un nuevo mecanismo para la creación de entrelazamiento en el estado estacionario, el cual puede ser manipulado en función de la amplitud del campo externo. Finalmente, hemos implementado experimentalmente un simulador cuántico para estudiar efectos mesoscópicos, mediante el uso de dispersi ón coherente en el cruce evitado de un sistema de dos qubits-SC, proporcionándose a su vez un análisis teórico de los resultados experimentales. Los eventos de dispersi ón son implementados controladamente como transiciones Landau-Zener generadas al conducir múltiple veces el qubit a través de de una cruce evitado. Estos resultados demuestran como un sistema bien controlado, consistente de un qubit conducido externamente, puede ser usado para estudiar efectos mesoscópicos complejos

Stenotrophomonas Maltophilia Endophthalmitis Caused by Surgical Equipment Contamination: an Emerging Nosocomial Infection

Purpose: We report three cases of Stenotrophomonas maltophilia endophthalmitis after uneventful extracapsular cataract extraction with intraocular lens implantation-related to surgical equipment contamination. Case report: All patients developed acute, culture-positive endophthalmitis in a period ranging from 2 to 13 days. Cultures from vitreous tap, as well as those obtained from the hand-piece of the irrigation-aspiration system, revealed S. maltophilia as the causing infectious agent. All patients received intravitreal antibiotic treatment as initial therapy, nevertheless, visual disturbance continued to be present, hence pars plana vitrectomy was required. Conclusion: Contamination of surgical-reusable equipment should be considered in addition to the well-known risk factors associated with development of endophthalmitis by S. maltophilia