Non-interventional Management of Asymptomatic Diminutive Choledocholithiasis Versus Endoscopic Extraction in Consecutive Patients.

BACKGROUND: Current guidelines recommend treating choledocholithiasis, regardless of symptoms or stone size, with endoscopic retrograde cholangiopancreatography (ERCP). However, asymptomatic choledocholithiasis, discovered incidentally on imaging, may carry a higher risk of ERCP-related adverse events, and some asymptomatic and diminutive stones may not cause biliary adverse events during extended follow-up. Therefore, we aimed to clarify the best treatment strategies for asymptomatic choledocholithiasis based on stone size. METHODS: We retrospectively identified patients with incidental imaging-found asymptomatic diminutive (≤ 4 mm) or non-diminutive (> 4 mm) choledocholithiasis and divided them into two groups: those who did not undergo ERCP and were treated when complications arose (on-demand group) and those who underwent ERCP before being symptomatic (intervention group). Adverse events were defined as any biliary or pancreatic complication related to ERCP or arising during observation or after intervention. The primary outcome was the adjusted overall adverse event-free survival using the propensity score-based matching weights method comparing the two groups of stone size. RESULTS: Among 148 patients identified (median follow-up period, 969 days), 68 had diminutive stones and 80 had non-diminutive stones. Of the 68 patients with diminutive stones, 51 were in the on-demand group and 17 in the intervention group. The overall adjusted adverse event-free survival was significantly higher in the on-demand group for diminutive stones (97.4% and 70.1%, respectively, at 3 years; p = 0.01). DISCUSSION: Patients with incidental imaging-detected asymptomatic diminutive choledocholithiasis may benefit from clinical observation, pursuing ERCP when symptoms develop.

Differential mechanisms for the inhibition of human cytochrome P450 1A2 by apigenin and genistein.

The inhibitory effects of flavonoids on the human cytochrome P450 1A2 (CYP1A2) were examined. Among flavonoids tested, galangin, kaempferol, chrysin, and apigenin were potent inhibitors. Although apigenin belonging to flavones and genistein belonging to isoflavones are similar in the chemical structures, the inhibitory potencies for CYP1A2 were distinguished markedly between these two flavonoids. In computer-docking simulation, apigenin interacted with the same mode of cocrystallized alpha-naphthoflavone in the active site of CYP1A2, and then the B ring of apigenin was placed close to the heme iron of the enzyme with a single orientation. In contrast, the docked genistein conformation showed two different binding modes, and the A ring of genistein was oriented to the heme iron of CYP1A2. Furthermore, the binding free energy of apigenin was lower than that of genistein. These results demonstrate a possible mechanism that causes the differential inhibitory potencies of apigenin and genistein for CYP1A2.