on behalf of the J-RHYTHM Registry Investigators* Background--To clarify the influence of hypertension and blood pressure (BP) control on thromboembolism and major hemorrhage in patients with nonvalvular atrial fibrillation, a post hoc analysis of the J-RHYTHM Registry was performed.

One of the two main photoproducts in bilirubin metabolism during phototherapy in neonatal hyperbilirubinaemia is (EZ)-cyclobilirubin. However, it has not yet been possible to come to a final conclusion as to its chemical structure, despite the fact that much effort has been expended on the problem. The present paper demonstrates that (EZ)-cyclobilirubin is formed by the intramolecular cyclization of the C-3-vinyl group with the position at C-7 rather than at C-6, without delta-lactone-ring formation. The evidence comes from 13C-n.m.r. spectra, which indicate that an oxygen-bound quaternary carbon atom is not present, and from 1H-n.m.r. spectra, which indicate that the orientation of the methyl group at C-2 is equatorial; these findings are supported by mass spectra. The existence of both an epimeric relationship at C-7 between (EE)- and (EZ)-cyclobilirubins A and B and of steric isomers of the hydrogen atom and methyl group at C-2 is supported by the fact that the methyl-group protons at C-2 and C-7 are observed as a paired signal in 1H-n.m.r. spectra, and that new signals at C-7, C-2 and C-3 beta appear in 13C-n.m.r. spectra, that mass spectra of (EZ)-cyclobilirubins A and B are extremely similar and that, furthermore, thermal interconversion between (EE)- and (EZ)-cyclobilirubins A and B is observed.

A kinetic study of the photochemical and thermal conversion of photoisomers, especialy peaks 0 and 3 [(EE)-bilirubin IX alpha and (EZ)- and (ZE)-bilirubin IX alpha], under anaerobic conditions, was performed by using reversed-phase high-pressure liquid chromatography. Peaks 0 and 3 are spontaneously, photochemically and thermally converted. Short-term photoirradiation of bilirubin gives a mixture containing not only the geometric isomers (EE)-, (EZ)- and (ZE)-bilirubin IX alpha, but also peak 2, (EZ)-cyclobilirubin IX alpha. On prolonged irradiation, cyclization and 15Z leads to 15E isomerization lead to gradual accumulation of two pairs of photoproducts: (EZ)-cyclobilirubin IX alpha A and B and (EE)-cyclobilirubin IX alpha A and B.

Background Blood pressure (BP) variability has reportedly been a risk factor for various clinical events. To clarify the influence of BP visit‐to‐visit variability on adverse events in patients with nonvalvular atrial fibrillation, a post hoc analysis of the J‐RHYTHM Registry was performed. Methods and Results Of 7406 outpatients with nonvalvular atrial fibrillation from 158 institutions, 7226 (age, 69.7±9.9 years; men, 70.7%), in whom BP was measured 4 times or more (14.6±5.0 times) during the 2‐year follow‐up period or until occurrence of an event, constituted the study group. SD and coefficient of variation of BP values were calculated as BP variability. Thromboembolism, major hemorrhage, and all‐cause death occurred in 110 (1.5%), 121 (1.7%), and 168 (2.3%) patients, respectively. When patients were divided into quartiles of systolic BP‐SD (<8.20, 8.20–10.49, 10.50–13.19, and ≥13.20 mm Hg), hazard ratios (HRs) for all adverse events were significantly high in the highest quartile compared with the lowest quartile (HR, 2.00, 95% CI, 1.15–3.49, P =0.015 for thromboembolism; HR, 2.60, 95% CI, 1.36–4.97, P =0.004 for major hemorrhage; and HR, 1.85, 95% CI, 1.11–3.07, P =0.018 for all‐cause death) after adjusting for components of the CHA 2 DS 2 ‐VASc score, warfarin and antiplatelet use, atrial fibrillation type, BP measurement times, and others. These findings were consistent when BP‐coefficient of variation was used instead of BP‐SD. Conclusions Systolic BP visit‐to‐visit variability was significantly associated with all adverse events in patients with nonvalvular atrial fibrillation. Further studies are needed to clarify the causality between BP variability and adverse outcomes in patients with nonvalvular atrial fibrillation. Registration URL: https://www.umin.ac.jp/ctr/ ; Unique Identifier: UMIN000001569.

On cycled exposure of Gunn rats to total darkness and low and high illumination, biliary excretion rates of (EZ)- and (ZE)-bilirubin and (EZ)-cyclobilirubin increased up to approx. 10-fold from the mean basal values of 1.2 and 0.2 microgram/h to the mean maximum values of 25.2 and 4.2 micrograms/h respectively, and at the same time those of (EE)-bilirubin and (EE)-cyclobilirubin also increased, but at very much lower rates than those of the first-mentioned two. During the low illumination only (EZ)- and (ZE)-bilirubin and (EZ)-cyclobilirubin appeared in the urine; during the high illumination (EE)-bilirubin and (EE)-cyclobilirubin also appeared, showing a similar excretion pattern to that observed in the bile, but the total urinary excretion rates were lower than the total biliary excretion rates. The serum bilirubin concentrations fell gradually to lower values, accompanied by an increment in (EZ)- and (ZE)-bilirubin, but (EZ)-cyclobilirubin was not detected. It is concluded that during phototherapy the predominant pathway for the removal of bilirubin from the body in the Gunn rat is by biliary excretion of the geometric photoisomers (EZ)- and (ZE)-bilirubin, derived from Z----E isomerization, and the structural photoisomer (EZ)-cyclobilirubin, formed from intramolecular endo-vinyl cyclization.