Determining the Location of the Fovea Centralis Via En-Face SLO and Cross-Sectional OCT Imaging in Patients Without Retinal Pathology.

Purpose: The purpose was to establish the position of the fovea centralis to the optic nerve via en-face, near-infrared spectral domain optical coherence tomography (NIR-OCT) in healthy patients. This may shed light on physiological variability and be used for studying subtle cases of foveal ectopia in macular pathology and after retinal detachment.

Methods: SD-OCT data of 890 healthy eyes were retrospectively analyzed.

Predictors of Universal Catheter Failure in Transradial Coronary Angiography.

Background: Use of a universal diagnostic catheter may decrease procedural time and catheter-exchange related spasm when compared with a dual-catheter strategy. The aim of this study was to identify preprocedural predictors of failure to complete a coronary angiogram with a universal catheter alone.

Methods: Consecutive patients (n = 782) who underwent a right transradial/transulnar coronary angiogram with a single operator were retrospectively reviewed.

Arsenic trioxide targets MTHFD1 and SUMO-dependent nuclear de novo thymidylate biosynthesis.

Arsenic exposure increases risk for cancers and is teratogenic in animal models. Here we demonstrate that small ubiquitin-like modifier (SUMO)- and folate-dependent nuclear de novo thymidylate (dTMP) biosynthesis is a sensitive target of arsenic trioxide (AsO), leading to uracil misincorporation into DNA and genome instability. Methylenetetrahydrofolate dehydrogenase 1 (MTHFD1) and serine hydroxymethyltransferase (SHMT) generate 5,10-methylenetetrahydrofolate for de novo dTMP biosynthesis and translocate to the nucleus during S-phase, where they form a multienzyme complex with thymidylate synthase (TYMS) and dihydrofolate reductase (DHFR), as well as the components of the DNA replication machinery.

Nuclear enrichment of folate cofactors and methylenetetrahydrofolate dehydrogenase 1 (MTHFD1) protect de novo thymidylate biosynthesis during folate deficiency.

Folate-mediated one-carbon metabolism is a metabolic network of interconnected pathways that is required for the de novo synthesis of three of the four DNA bases and the remethylation of homocysteine to methionine. Previous studies have indicated that the thymidylate synthesis and homocysteine remethylation pathways compete for a limiting pool of methylenetetrahydrofolate cofactors and that thymidylate biosynthesis is preserved in folate deficiency at the expense of homocysteine remethylation, but the mechanisms are unknown. Recently, it was shown that thymidylate synthesis occurs in the nucleus, whereas homocysteine remethylation occurs in the cytosol.