99 research outputs found
In vitro effect photodynamic therapy with differents photosensitizers on cariogenic microorganisms
Background
Antimicrobial photodynamic therapy has been proposed as an alternative to suppress subgingival species. This results from the balance among Streptococcus sanguis, Streptococcus mutans and Candida albicans in the dental biofilm. Not all the photosensitizers have the same photodynamic effect against the different microorganims. The objective of this study is to compare in vitro the photodynamic effect of methylene blue (MB), rose Bengal (RB) and curcumin (CUR) in combination with white light on the cariogenic microorganism S. mutans, S. sanguis and C. albicans.
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Results
Photodynamic therapy with MB, RB and CUR inhibited 6 log 10 the growth of both bacteria but at different concentrations: 0.31–0.62 μg/ml and 0.62–1.25 μg/ml RB were needed to photoinactivate S. mutans and S. sanguis, respectively; 1.25–2.5 μg/ml MB for both species; whereas higher CUR concentrations (80–160 μg/ml and 160–320 μg/ml) were required to obtain the same reduction in S. mutans and S. sanguis viability respectively. The minimal fungicidal concentration of MB for 5 log10 CFU reduction (4.5 McFarland) was 80–160 μg/ml, whereas for RB it ranged between 320 and 640 μg/ml. For CUR, even the maximum studied concentration (1280 μg/ml) did not reach that inhibition. Incubation time had no effect in all experiments.
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Conclusions
Photodynamic therapy with RB, MB and CUR and white light is effective in killing S. mutans and S. sanguis strains, although MB and RB are more efficient than CUR. C. albicans required higher concentrations of all photosensitizers to obtain a fungicidal effect, being MB the most efficient and CUR ineffective.España, Ministerio de Ciencia e Innovación CTQ2013-48767-C3-2-
Determinantes socioeconómicos y próximos de la mortalidad de niños menores de cinco años en el Perú (2015-2018)
The objective of this study is to find the socioeconomic and proximate determinants of mortality in children under five years of age in Peru. To this end, the study focuses on the theoretical approach of Mosley and Chen (1984) and employs the econometric methodology of the Cox semi-parametric and proportional hazards model and the Kaplan and Meier non-parametric model. With regard to socioeconomic determinants, the results show that the mother’s years of education, the household economic status, and the mother’s health coverage significantly reduce the risk of death for children under the age of five. Likewise, the mother’s years of education has a significant interaction effect with the household socioeconomic level and access to health service coverage, which influence child survival. As for the proximal determinants, the mother’s age, birth intervals, birth order, and health facilities all predict the risk of death for children under five years of age.El objetivo del estudio fue encontrar los determinantes socioeconómicos y próximos de la mortalidad de niños menores de cinco años en el Perú. Con tal propósito el estudio se centra en el enfoque teórico de Mosley y Chen (1984), y en la metodología econométrica de los modelos de duración semi paramétrica de riesgos proporcionales de Cox y no paramétrica de Kaplan y Meier. En lo referente a los determinantes socioeconómicos, los resultados muestran que los años de educación de la madre, el estatus económico del hogar y las coberturas de salud de la madre disminuyen significativamente el riesgo de muerte de los niños menores de cinco años. Asimismo, los años de educación de la madre tienen un efecto interactivo significativo con el nivel socioeconómico del hogar y el acceso a la cobertura de servicio de salud para influir sobre la supervivencia infantil. En cuanto a los determinantes próximos, la edad de la madre, los intervalos entre naci-mientos, el orden de nacimiento de los hijos, y las instalaciones sanitarias predicen el riesgo de muerte de los niños menores de cinco años
In vitro effect photodynamic therapy with differents photosensitizers on cariogenic microorganisms
Background: Antimicrobial photodynamic therapy has been proposed as an alternative to suppress subgingival species. This results from the balance among Streptococcus sanguis, Streptococcus mutans and Candida albicans in the dental biofilm. Not all the photosensitizers have the same photodynamic effect against the different microorganims. The objective of this study is to compare in vitro the photodynamic effect of methylene blue (MB), rose Bengal (RB) and curcumin (CUR) in combination with white light on the cariogenic microorganism S. mutans, S. sanguis and C. albicans. Results: Photodynamic therapy with MB, RB and CUR inhibited 6 log 10 the growth of both bacteria but at different concentrations: 0.31-0.62 µg/ml and 0.62-1.25 µg/ml RB were needed to photoinactivate S. mutans and S. sanguis, respectively//1.25-2.5 µg/ml MB for both species//whereas higher CUR concentrations (80-160 µg/ml and 160-320 µg/ml) were required to obtain the same reduction in S. mutans and S. sanguis viability respectively. The minimal fungicidal concentration of MB for 5 log10 CFU reduction (4.5 McFarland) was 80-160 µg/ml, whereas for RB it ranged between 320 and 640 µg/ml. For CUR, even the maximum studied concentration (1280 µg/ml) did not reach that inhibition. Incubation time had no effect in all experiments. Conclusions: Photodynamic therapy with RB, MB and CUR and white light is effective in killing S. mutans and S. sanguis strains, although MB and RB are more efficient than CUR. C. albicans required higher concentrations of all photosensitizers to obtain a fungicidal effect, being MB the most efficient and CUR ineffective
On the nature of the extragalactic number counts in the K-band
We investigate the causes of the different shape of the -band number
counts when compared to other bands, analyzing in detail the presence of a
change in the slope around . We present a near-infrared imaging
survey, conducted at the 3.5m telescope of the Calar Alto Spanish-German
Astronomical Center (CAHA), covering two separated fields centered on the HFDN
and the Groth field, with a total combined area of deg to a
depth of (,Vega). We derive luminosity functions from the
observed -band in the redshift range [0.25-1.25], that are combined with
data from the references in multiple bands and redshifts, to build up the
-band number count distribution. We find that the overall shape of the
number counts can be grouped into three regimes: the classic Euclidean slope
regime () at bright magnitudes; a transition regime at
intermediate magnitudes, dominated by galaxies at the redshift that
maximizes the product ; and an
dominated regime at faint magnitudes, where the slope asymptotically approaches
-0.4(+1) controlled by post- galaxies. The slope of the
-band number counts presents an averaged decrement of in the range
(). The rate of change in the slope is
highly sensitive to cosmic variance effects. The decreasing trend is the
consequence of a prominent decrease of the characteristic density
( from to ) and an almost flat
evolution of (1 compatible with
in the same redshift range).Comment: 18 pages, 22 figures, Accepted by Astronomy & Astrophysic
Convertir el Trabajo de Fin de Asignatura (TFA) en aportación de calidad al conocimiento social
Depto. de Filología ClásicaFac. de FilologíaFALSEsubmitte
Evaluation of the neuroprotective efficacy of the gramine derivative ITH12657 against NMDA-induced excitotoxicity in the rat retina
PurposeThe aim of this study was to investigate, the neuroprotective effects of a new Gramine derivative named: ITH12657, in a model of retinal excitotoxicity induced by intravitreal injection of NMDA.MethodsAdult Sprague Dawley rats received an intravitreal injection of 100 mM NMDA in their left eye and were treated daily with subcutaneous injections of ITH12657 or vehicle. The best dose–response, therapeutic window study, and optimal treatment duration of ITH12657 were studied. Based on the best survival of Brn3a + RGCs obtained from the above-mentioned studies, the protective effects of ITH12657 were studied in vivo (retinal thickness and full-field Electroretinography), and ex vivo by quantifying the surviving population of Brn3a + RGCs, αRGCs and their subtypes α-ONsRGCs, α-ONtRGCs, and α-OFFRGCs.ResultsAdministration of 10 mg/kg ITH12657, starting 12 h before NMDA injection and dispensed for 3 days, resulted in the best significant protection of Brn3a + RGCs against NMDA-induced excitotoxicity. In vivo, ITH12657-treated rats showed significant preservation of retinal thickness and functional protection against NMDA-induced retinal excitotoxicity. Ex vivo results showed that ITH12657 afforded a significant protection against NMDA-induced excitotoxicity for the populations of Brn3a + RGC, αRGC, and αONs-RGC, but not for the population of αOFF-RGC, while the population of α-ONtRGC was fully resistant to NMDA-induced excitotoxicity.ConclusionSubcutaneous administration of ITH12657 at 10 mg/kg, initiated 12 h before NMDA-induced retinal injury and continued for 3 days, resulted in the best protection of Brn3a + RGCs, αRGC, and αONs-RGC against excitotoxicity-induced RGC death. The population of αOFF-RGCs was extremely sensitive while α-ONtRGCs were fully resistant to NMDA-induced excitotoxicity
Bactericidal Effect of Photodynamic Therapy, Alone or in Combination with Mupirocin or Linezolid, on Staphylococcus aureus
Antibiotic treatments frequently fail due to the development of antibiotic resistance, underscoring the need for new treatment strategies. Antimicrobial photodynamic therapy (aPDT) could constitute an alternative therapy. In bacterial suspensions of Staphylococcus aureus, which is commonly implicated in cutaneous and mucosal infections, we evaluated the in vitro efficacy of aPDT, using the photosensitizing agents rose bengal (RB) or methylene blue (MB), alone or combined with the antibiotics mupirocin (MU) or linezolid (LN). RB or MB, at concentrations ranging from 0.03 to 10 μg/ml, were added to S. aureus ATCC 29213 suspensions containing >108 cells/ml, in the absence or presence of MU or LN (1 or 10 μg/ml). Suspensions were irradiated with a white metal halide (λ 420–700 nm) or light-emitting diode lamp (λ 515 and λ 625 nm), and the number of viable bacteria quantified by counting colony-forming units (CFU) on blood agar. Addition of either antibiotic had no significant effect on the number of CFU/ml. By contrast, RB-aPDT and MB-aPDT effectively inactivated S. aureus, as evidenced by a 6 log10 reduction in bacterial growth. In the presence of MU or LN, the same 6 log10 reduction was observed in response to aPDT, but was achieved using significantly lower concentrations of the photosensitizers RB or MB. In conclusion, the combination of MU or LN and RB/MB-aPDT appears to exert a synergistic bactericidal effect against S. aureus in vitro
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