Taxane diterpenoids from the stem bark of Taxus mairei.

Three new 11(15-->1)-abeo-taxanes, taxumairols U-W (1-3), have been isolated from extracts of the stem bark of Formosan Taxus mairei. The structures of 1-3 were identified as 5alpha,7beta,9alpha,13alpha,20-pentaacetoxy-2alpha,10beta,15-trihydroxy-11(15-->1)-abeo-taxene, 5alpha,7beta,9alpha,20-tetraacetoxy-2alpha,10beta,13alpha,15-tetrahydroxy-11(15-->1)-abeo-taxene, and 2alpha,4alpha,7beta,10beta-tetraacetoxy-5beta,20-epoxy-9alpha,13alpha,15-trihydroxy-11(15-->1)-abeo-taxene, respectively, on the basis of 2D NMR techniques including COSY, HSQC, HMBC, and NOESY experiments as well as chemical reactions of compounds 1-3 to give 4 (5alpha,7beta,9alpha,10beta,13alpha,20-hexaacetoxy-2alpha,15-dihydroxy-11(15-->1)-abeo-taxene) and 5 (4alpha,7beta,10beta-triacetoxy-9alpha,13alpha-dibenzoxy-5beta,20-epoxy-2alpha,15-dihydroxy-11(15-->1)-abeo-taxene), which are also novel taxane derivatives. Taxumairols U (1) and V (2) exhibited significant cytotoxicities against human hepatoma tumor cells, while taxumairol W (3) was inactive.

Apoplectic optochiasmal syndrome due to intrinsic cavernous hemangioma. Case report.

A 42-year-old man suffered from acute evolving visual loss after drinking alcohol. Consecutive visual field changes suggested a mass within the left optic nerve extending its compression across the chiasm and encroaching on the left optic tract. Computed tomography scanning and magnetic resonance imaging confirmed the presence of an overt hemorrhage, a real apoplectic event of cavernous hemangioma. Cavernous hemangiomas located within the intracranial optic nerve are few. Occult hemorrhage within the confines of the intrinsic vascular tumor resulted in acute visual changes in most reported cases. Overt hemorrhage with blood extravasation beyond the original confines of the intrinsic optochiasmal tumor are rarely reported in the literature. Herein, we report one such case. The clinical course and the predisposing factors are also discussed.

RUBIDIUM, a program for computer-aided assignment of two-dimensional NMR spectra of polypeptides.

Taking advantage of the rule-based expert system technology, a program named RUBIDIUM (Rule-Based Identification In 2D NMR Spectrum) was developed to accomplish the automatic 1H NMR resonance assignments of polypeptides. Besides noise elimination and peak selection capabilities, RUBIDIUM detects the cross-peak patterns of amino acid residues in the COSY spectrum, assigning these patterns to amino acid types, performing sequential assignments using combined COSY/NOESY spectra, and finally, achieving the total assignment of the 1H NMR spectrum.

Hemodynamic effects of hydralazine in mitral valve prolapse with regurgitation.

Vasodilators cause the earlier occurrence of click and prolong the duration of regurgitation murmur in mitral valve prolapse (MVP), meanwhile, they also decrease the intensity of murmur. To investigate the net effects of vasodilators on mitral regurgitation (MR) caused by MVP, we studied the hemodynamic responses to intravenous hydralazine in 10 patients with MVP and associated MR. The results showed that hydralazine reduced systemic vascular resistance by 28% (1705 +/- 307 to 1223 +/- 227 dyne-sec-cm5 p less than 0.001) and produced a 30% increase in cardiac output (4.4 +/- 0.7 to 5.7 +/- 0.7 l/min, p less than 0.001). The forward stroke volume increased by 18% (56 +/- 12 to 66 +/- 11 ml, p less than 0.001), while regurgitant stroke volume fell by 14% (46 +/- 22 to 40 +/- 23 ml, p less than 0.05), with a resultant slight fall in pulmonary capillary wedge v wave (13 +/- 5 to 11 +/- 3 mmHg, p = 0.05). We thus suggest that hydralazine has beneficial hemodynamic effects on MVP with regurgitation, and may be effective in the treatment of these patients.