S-nitrosocaptopril nanoparticles as nitric oxide-liberating and transnitrosylating anti-infective technology.

Nitric oxide (NO), an essential agent of the innate immune system, exhibits multi-mechanistic antimicrobial activity. Previously, NO-releasing nanoparticles (NO-np) demonstrated increased antimicrobial activity when combined with glutathione (GSH) due to formation of S-nitrosoglutathione (GSNO), a transnitrosylating agent. To capitalize on this finding, we incorporated the thiol-containing ACE-inhibitor, captopril, with NO-np to form SNO-CAP-np, nanoparticles that both release NO and form S-nitrosocaptopril. In the presence of GSH, SNO-CAP-np demonstrated increased transnitrosylation activity compared to NO-np, as exhibited by increased GSNO formation. Escherichia coli and methicillin-resistant Staphylococcus aureus were highly susceptible to SNO-CAP-np in a dose-dependent fashion, with E. coli being most susceptible, and SNO-CAP-np were nontoxic in zebrafish embryos at translatable concentrations. Given SNO-CAP-np's increased transnitrosylation activity and increased E. coli susceptibility compared to NO-np, transnitrosylation rather than free NO is likely responsible for overcoming E. coli's resistance mechanisms and ultimately killing the pathogen. FROM THE CLINICAL EDITOR: This team of authors incorporated the thiol-containing ACE-inhibitor, captopril, into a nitric oxide releasing nanoparticle system, generating nanoparticles that both release NO and form S-nitrosocaptopril, with pronounced toxic effects on MRSA and E. coli in the presented model system.

A Morphometric Study of the Pars Plana of the Ciliary Body in Human Cadaver Eyes.

This study aimed to determine the pars plana length in postmortem human eyes using advanced morphometric techniques and correlate demographics to ocular metrics such as age, sex, ethnicity, and axial length. Between February and July 2005, we conducted a cross-sectional observational study on 46 human cadaver eyes deemed unsuitable for transplant by the SBO Eye Bank. The morphometric analysis was performed on projected images using a surgical microscope and a video-microscopy system with a 20.5:1 correction factor. The pars plana length was measured three times per quadrant, with the final value being the mean of these measurements. Of the 46 eyes collected, 9 were unsuitable for the study due to technical constraints in conducting intraocular measurements. Overall, the average axial length was 25.20 mm. The average pars plana length was 3.8 mm in all quadrants, with no measurements below 2.8 mm or above 4.9 mm. There were no statistically significant variations across quadrants or with age, sex, axial length, or laterality. Accurately defining the pars plana dimensions is crucial for safely accessing the posterior segment of the eye and minimizing complications during intraocular procedures, such as intravitreal injections and vitreoretinal surgeries.