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Introducción: A finales de 2019 se detectaron en Wuhan los primeros casos de una neumonía identificada por una nueva cepa de coronavirus reconocido como SARS-CoV-2, y la enfermedad que causa se denominó COVID-19, cuya propagación es más probable que ocurra cuando hay un contacto cercano (a 2 metros o menos) con una persona infectada. Es por ello que se hace necesario en cada uno de los servicios, en particular en Oftalmología, establecer las medidas al respecto. Objetivo: Relacionar las medidas higiénico sanitarias a cumplimentar en los servicios de Oftalmología y proponer las que deben de aplicarse en Cuba. Material y método: Se realiza la revisión de las publicaciones sobre la COVID-19, las características del coronavirus SARS-CoV-2, suformas de propagación, las manifestaciones clínico-epidemiológicas de la enfermedad, que incluyeron libro de prevención contra esta y el protocolo de actuación del Ministerio de Salud Pública, las propuestas de varios países e instituciones para las actividades post-COVID y la participación en el Seminario Internacional de Seguridad, Salud y Trabajo y la COVID-19, auspiciado por la Organización Panamericana de la Salud. Resultados: Establecimiento de las medidas higiénico sanitarias a cumplimentar en los servicios de Oftalmología, teniendo en cuenta las características de estos servicios y las principales regulaciones higiénico-sanitarias nacionales e internacionales ante esta pandemia. Introduction: At the end of 2019, the first cases of pneumonia identified by a new strain of coronavirus recognized as SARS-CoV-2 were detected in Wuhan, and the disease it causes was called COVID19, the spread of which is more likely to occur when there is close contact (2 meters or less) with an infected person. That is why it is necessary in each of the services, in particular in Ophthalmology, to establish the measures in this regard. Objective: To relate the hygienic-sanitary measures to be completed in the Ophthalmology services and propose those that should be applied in Cuba. Material and method: A review of the publications on COVID-19, the characteristics of the SARS-CoV-2 coronavirus, its forms of spread, the clinical-epidemiological manifestations of the disease is carried out, which included a prevention book against it and the action protocol of the Ministry of Public Health, the proposals of various countries and institutions for post-covid activities and participation in the International Seminar on Safety, Health, and Work and COVID-19, sponsored by the Pan American Health Organization. Results: Establishment of sanitary hygiene measures to be completed in Ophthalmology services, taking into account the characteristics of these services and the main national and international hygiene-sanitary regulations in the face of this pandemic.

Filariasis is a tropical disease caused by the parasitic nematodes Wuchereria bancrofti and Brugia malayi. Known inhibitors of dihydrofolate reductase (DHFR) have been previously shown to kill Brugia malayi nematodes and to inhibit Brugia malayi DHFR (BmDHFR) at nanomolar concentrations. These data suggest that BmDHFR is a potential target for the treatment of filariasis. Here, protocols for cloning, expression and purification of Wuchereria bancrofti DHFR (WbDHFR) were developed. The Uniprot entry J9F199-1 predicts a 172 amino acid protein for WbDHFR but alignment of this sequence to the previously described BmDHFR shows that this WbDHFR sequence lacks a crucial, conserved 13 amino acid loop. The presence of the loop in WbDHFR is supported by a noncanonical splicing event and the loop sequence was therefore included in the gene design. Subsequently, the KM for dihydrofolate (3.7 ± 2 μM), kcat (7.4 ± 0.6 s-1), and pH dependence of activity were determined. IC50 values of methotrexate, trimethoprim, pyrimethamine, raltitrexed, aminopterin, (-)-epicatechin gallate, (-)-epicatechin, and vitexin were measured for WbDHFR and BmDHFR. Methotrexate and structurally related aminopterin were found to be effective inhibitors of WbDHFR, with an KI of 1.2 ± 0.2 nM and 2.1 ± 0.5 nM, respectively, suggesting that repurposing of known antifolate compound may be an effective strategy to treating filariasis. Most compounds showed similar inhibition profiles toward both enzymes, suggesting that the two enzymes have important similarities in their active site environments and can be targeted with the same compound, once a successful inhibitor is identified.

(-)-Epigallocatechin 3-O-gallate (EGCG) a molecule found in green tea and known for a plethora of bioactive properties is an inhibitor of heat shock protein 90 (HSP90), a protein of interest as a target for cancer and neuroprotection. Determination of the spectral properties of EGCG fluorescence in environments similar to those of binding sites found in proteins provides an important tool to directly study protein-EGCG interactions. The goal of this study is to examine the spectral properties of EGCG fluorescence in an aqueous buffer (AB) at pH=7.0, acetonitrile (AN) (a polar aprotic solvent), dimethylsulfoxide (DMSO) (a polar aprotic solvent), and ethanol (EtOH) (a polar protic solvent). We demonstrate that EGCG is a highly fluorescent molecule when excited at approximately 275 nm with emission maxima between 350 and 400 nm depending on solvent. Another smaller excitation peak was found when EGCG is excited at approximately 235 nm with maximum emission between 340 and 400 nm. We found that the fluorescence intensity (FI) of EGCG in AB at pH=7.0 is significantly quenched, and that it is about 85 times higher in an aprotic solvent DMSO. The Stokes shifts of EGCG fluorescence were determined by solvent polarity. In addition, while the emission maxima of EGCG fluorescence in AB, DMSO, and EtOH follow the Lippert-Mataga equation, its fluorescence in AN points to non-specific solvent effects on EGCG fluorescence. We conclude that significant solvent-dependent changes in both fluorescence intensity and fluorescence emission shifts can be effectively used to distinguish EGCG in aqueous solutions from EGCG in environments of different polarity, and, thus, can be used to study specific EGCG binding to protein binding sites where the environment is often different from aqueous in terms of polarity.