Comparación de Latanoprostene bunod 0,024 % y Latanoprost 0,005 % en glaucoma de ángulo abierto e hipertensión ocular

Introducción: El glaucoma es la principal causa de ceguera irreversible en el mundo. La prevalencia mundial de glaucoma en personas de 40 a 80 años se estima en un 3,5 %. Objetivo: Comparar el efecto reductor de la PIO de Latanoprostene bunod (LBN) al 0,024% con Latanoprost al 0,005 % en sujetos con glaucoma de ángulo abierto (GAA) o hipertensión ocular (HTO). Metodología: Ensayo observacional de estudio de cohorte prospectivo. Resultados: Fue realizado en 28 pacientes (56 ojos) quienes fueron aleatorizados en 2 grupos paralelos (28 ojos por grupo), el grupo Latanoprost y el grupo LBN. En el grupo LBN la media de la PIO antes del tratamiento fue de 25,3 ± 6,6 mmHg y la media de la PIO luego de 1 mes de tratamiento fue de 16,5 ± 4,9 mmHg (p<0,05). En el grupo Latanoprost la media de la PIO antes del tratamiento fue de 23,6 ± 3,6 mmHg y la media de la PIO luego de 1 mes de tratamiento con Latanoprost al 0,005% fue de 15,3 ± 2,4 mmHg (p<0,05). Sin embargo, al comparar las PIOs luego de 1 mes de tratamiento con LBN 0,024% y Latanoprost 0,005% se objetiva que la diferencia en reducción de la presión intraocular entre estos dos fármacos no fue significativa (p= 0,238). Discusión: Las prostaglandinas tópicas, con su potente efecto hipotensor ocular son una importante opción de tratamiento para el glaucoma. La reducción de la PIO es la esperada con ambos medicamentos, sin embargo, no existen diferencias significativas entre ambas luego de 1 mes de uso. Con respecto a los efectos secundarios, en el grupo LBN se encontró más efectos adversos oculares.

Introduction: Glaucoma is the main cause of irreversible blindness worldwide. The global prevalence of glaucoma in people aged 40 to 80 years is estimated at 3.5%. Objective: To compare the intraocular pressure (IOP) lowering effect of 0.024% Latanoprostene bunod (LBN) with 0.005% Latanoprost in subjects with open-angle glaucoma (OAG) or ocular hypertension (OHT). Methods: Observational trial of prospective cohort study. Results: It was performed in 28 patients (56 eyes) who were randomized into 2 parallel groups (28 eyes per group), the Latanoprost group and the Latanoprostene bunod (LBN) group. In the LBN group, the mean intraocular pressure before treatment was 25.3 ± 6.6 mmHg and the mean intraocular pressure after 1 month of treatment was 16.5 ± 4.9 mmHg (p<0,05). In the Latanoprost group, the mean intraocular pressure before treatment was 23.6 ± 3.6 mmHg and the mean intraocular pressure after 1 month of treatment with 0.005% Latanoprost was 15.3 ± 2.4 mmHg (p<0,05). However, when comparing the IOPs to the 1-month treatment with Latanoprostene bunod 0.024% and Latanoprost 0.005%, it is observed, through ANOVA, that the difference in intraocular pressure reduction between these two drugs is not significant (p= 0,238). Discussion: Topical prostaglandins, with their potent ocular hypotensive effect (resulting from increased uveoscleral outflow), are an important treatment option for glaucoma. The IOP reduction is as expected with both drugs, however, there are no significant differences between the two. In the LBN group, more drug-related ocular adverse effects were found after 1 month of use.

Aqueous Emulsion Droplets Stabilized by Lipid Vesicles as Microcompartments for Biomimetic Mineralization.

Mineral deposition within living cells relies on control over the distribution and availability of precursors as well as the location and rates of nucleation and growth. This control is provided in large part by biomolecular chelators, which bind precursors and regulate their availability, and compartmentalization within specialized mineralizing vesicles. Biomimetic mineralization in self-assembled lipid vesicles is an attractive means of studying the mineralization process, but has proven challenging due to vesicle heterogeneity in lamellarity, contents, and size across a population, difficulties encapsulating high and uniform precursor concentrations, and the need to transport reagents across an intact lipid bilayer membrane. Here, we report the use of liposome-stabilized all-aqueous emulsion droplets as simple artificial mineralizing vesicles (AMVs). These biomimetic microreactors allow the entry of precursors while retaining a protein catalyst by equilibrium partitioning between internal and external polymer-rich phases. Small molecule chelators with intermediate binding affinity were employed to control Ca(2+) availability during CaCO3 mineralization, providing protection against liposome aggregation while allowing CaCO3 formation. Mineral deposition was limited to the AMV interior, due to localized production of CO3(2-) by compartmentalized urease. Particle formation was uniform across the entire population of AMVs, with multiple submicrometer amorphous CaCO3 particles produced in each one. The all-aqueous emulsion-based approach to biomimetic giant mineral deposition vesicles introduced here should be adaptable for enzyme-catalyzed synthesis of a wide variety of materials, by varying the metal ion, enzyme, and/or chelator.

Bioreactor droplets from liposome-stabilized all-aqueous emulsions.

Artificial bioreactors are desirable for in vitro biochemical studies and as protocells. A key challenge is maintaining a favourable internal environment while allowing substrate entry and product departure. We show that semipermeable, size-controlled bioreactors with aqueous, macromolecularly crowded interiors can be assembled by liposome stabilization of an all-aqueous emulsion. Dextran-rich aqueous droplets are dispersed in a continuous polyethylene glycol (PEG)-rich aqueous phase, with coalescence inhibited by adsorbed ~130-nm diameter liposomes. Fluorescence recovery after photobleaching and dynamic light scattering data indicate that the liposomes, which are PEGylated and negatively charged, remain intact at the interface for extended time. Inter-droplet repulsion provides electrostatic stabilization of the emulsion, with droplet coalescence prevented even for submonolayer interfacial coatings. RNA and DNA can enter and exit aqueous droplets by diffusion, with final concentrations dictated by partitioning. The capacity to serve as microscale bioreactors is established by demonstrating a ribozyme cleavage reaction within the liposome-coated droplets.

Biocatalyzed mineralization in an aqueous two-phase system: effect of background polymers and enzyme partitioning.

The formation of minerals in living organisms occurs in crowded microenvironments generated by the organization of soft matter. Here, we used a biphasic aqueous polymer medium to mimic the macromolecular crowding and compartmentalization of intracellular environments. Mineralization was performed in an aqueous two-phase system (ATPS) containing two nonionic polymers, poly(ethylene glycol) (PEG, 8 kDa) and dextran (Dx, 10 kDa). The enzyme urease was used to catalyze CaCO3 formation by hydrolyzing urea to produce CO3 2-, which reacted with Ca2+ already present in solution. Urease partitioning into the Dx-rich phase provided a mechanism for localizing the hydrolysis reaction, which consequently restricted mineral formation to this phase, despite the initially equal concentration of Ca2+ in both phases. Spatially confined mineralization was quantified by sampling the phases during bulk reactions and also directly observed in microscale systems by optical microscopy. Decreasing the volume of the Dx-rich phase relative to that of the PEG-rich phase significantly enhanced the local urease concentration in the Dx-rich phase, increasing local reaction rates. The PEG and Dx polymers, though present at up to 30 wt% in the ATPS, did not strongly influence the morphology of CaCO3(s) observed. However, addition of ovalbumin (1.5 wt%) caused marked changes in crystal morphology. The PEG/dextran ATPS reaction medium captured several key aspects of the biological environment including macromolecular crowding, localized reagent production via enzymatic activity, and reaction compartmentalization while not precluding the use of structure-directing additives such as proteins.

Spectrophotometric determination of aqueous cyanide using a revised phenolphthalin method.

This paper focuses on a revision of the phenolphthalin method for cyanide analysis, with the intent of producing a robust and sensitive spectrophotometric method. Limitations of the phenolphthalin chemistry were overcome by the addition of EDTA to the reagent. The revised reagent was found to have suitably fast kinetics, a linear dynamic range of 0.01-3.0 ppm cyanide, and a detection limit of 5 ppb. The method was tested for interferences and applied to the determination of cyanide in environmental waters.