Inter-ethnic differences in valve morphology, valvular dysfunction, and aortopathy between Asian and European patients with bicuspid aortic valve.

Background: Transcatheter aortic valve replacement (TAVR) has been shown safe and feasible in patients with bicuspid aortic valve (BAV) morphology. Evaluation of inter-ethnic differences in valve morphology and function and aortic root dimensions in patients with BAV is important for the worldwide spread of this therapy in this subgroup of patients. Comparisons between large European and Asian cohorts of patients with BAV have not been performed, and potential differences between populations may have important implications for TAVR. Aim: The present study evaluated the differences in valve morphology and function and aortic root dimensions between two large cohorts of European and Asian patients with BAV. Methods and results: Aortic valve morphology was defined on transthoracic echocardiography according to the number of commissures and raphe: type 0 = no raphe and two commissures, type 1 = one raphe and two commissures, type 2 = two raphes and one commissure. Aortic stenosis and regurgitation were graded according to current recommendations. For this study, aortic root dimensions were manually measured on transthoracic echocardiograms at the level of the aortic annulus, sinus of Valsalva (SOV), sinotubular junction (STJ), and ascending aorta (AA). Of 1427 patients with BAV (45.2 ± 18.1 years, 71.9% men), 794 (55.6%) were Europeans and 633 (44.4%) were Asians. The groups were comparable in age and proportion of male sex. Asians had higher prevalence of type 1 BAV with raphe between right and non-coronary cusps than Europeans (19.7% vs. 13.6%, respectively; P < 0.001), whereas the Europeans had higher prevalence of type 0 BAV (two commissures, no raphe) than Asians (14.5% vs. 6.8%, respectively; P < 0.001). The prevalence of moderate and severe aortic regurgitation was higher in Europeans than Asians (44.2% vs. 26.8%, respectively; P < 0.001) whereas there were no differences in BAV with normal function or aortic stenosis. After adjusting for demographics, comorbidities, and valve function, the dimensions of the aortic annulus [mean difference 1.17 mm/m2, 95% confidence interval (CI) 0.96-1.39], SOV (mean difference 1.86 mm/m2, 95% CI 1.47-2.24), STJ (mean difference 0.52 mm/m2, 95% CI 0.14-0.90) and AA (mean difference 1.05 mm/m2, 95% CI 0.57-1.52) were significantly larger among Asians compared with Europeans. Conclusions: This large multicentre registry reports for the first time that Asians with BAV showed more frequently type 1 BAV (with fusion between right and non-coronary cusp) and have larger aortic dimensions than Europeans. These findings have important implications for prosthesis type and size selection for TAVR.

Cyclopenta[b]benzofuran and Secodammarane Derivatives from the Stems of Aglaia stellatopilosa.

Four new 2,3-secodammarane triterpenoids, stellatonins A-D (3-6), together with a new 3,4-secodammarane triterpenoid, stellatonin E (7), and the known silvestrol (1), 5‴-episilvestrol (2), and ß-sitosterol, were isolated from a methanol extract of the stems of Aglaia stellatopilosa through bioassay-guided fractionation. The structures of the new compounds were elucidated using spectroscopic and chemical methods. The compounds were evaluated for their cytotoxic activity against three human cancer cell lines and for their antimicrobial activity using a microtiter plate assay against a panel of Gram-positive and Gram-negative bacteria and fungi.

Nuclear export of NBN is required for normal cellular responses to radiation.

Nijmegen breakage syndrome arises from hypomorphic mutations in the NBN gene encoding nibrin, a component of the MRE11/RAD50/nibrin (MRN) complex. In mammalian cells, the MRN complex localizes to the nucleus, where it plays multiple roles in the cellular response to DNA double-strand breaks. In the current study, sequences in mouse nibrin required to direct the nuclear localization of the MRN complex were identified by site-specific mutagenesis. Unexpectedly, nibrin was found to contain both nuclear localizing signal (NLS) sequences and a nuclear export signal (NES) sequence whose functions were confirmed by mutagenesis. Both nuclear import and export sequences were active in vivo. Disruption of either the NLS or NES sequences of nibrin significantly altered the cellular distribution of nibrin and Mre11 and impaired survival after exposure to ionizing radiation. Mutation of the NES sequence in nibrin slowed the turnover of phosphorylated nibrin after irradiation, indicating that nuclear export of nibrin may function, in part, to downregulate posttranslationally modified MRN complex components after DNA damage responses are complete.