12 research outputs found
Lymphoepithelioma-like carcinoma of the vulva, an underrecognized entity? Case report with a single inguinal micrometastasis detected by sentinel node technique
This report describes an unusual EBV-negative lymphoepithelioma-like carcinoma of the vulva in a 73-year-old patient. The lesion was localised at the right minor labium and was resected by partial vulvectomy. A synchronous sentinel lymph node biopsy revealed a single micrometastasis in the right inguinal region, which prompted local radiotherapy. Follow-up nine months later showed only slight vulvar atrophy, without signs of local recurrence or distant metastases
Synthesis of Hypoxanthine, Guanine, and 6-Thiopurine Nucleosides of 6-Deoxy-D-allofuranose
Hypoxanthine, guanine, and 6-thiopurine nucleosides of 6-deoxy-D-allofuranose have been prepared as potential antitumor agents. Thus, reaction of 6-deoxy-|8-D-allofuranosyl bromide (1) with the trimethylsilyl derivatives of hypoxanthine and guanine afforded mixtures of the 9- and the 7-substituted bases, which were separated and deblocked with ammonia to give 9-(6âČ-deoxy-|9-D-allofuranosyl)hypoxanthine (6), 7-(6âČ-deoxy-ÎČ-D-allofuranosyl)hypoxanthine (7), 9-(6âČ-deoxy-/3-D-allofuranosyl)guanine (8), and 7-(6âČ-deoxy-/3-D-allofuranosyl)guanine (9). The two nucleosides with the purine joined at the N-9 position, namely, 6 and 8, are easily distinguished from the other two nucleosides (7 and 9), having N-7 junctions, by their NMR spectra. Reaction of 1 with the trimethylsilyl derivative of 6-chloropurine afforded 10, which upon treatment with thiourea and deblocking gave 9-(6âČ-deoxy-/3-D-allofuranosyl)-6-thiopurine (12). The hypoxanthine and guanine nucleosides showed no inhibition of mouse leukemia L1210 when tested in vivo, but the thiopurine nucleoside 12 showed strong inhibition of growth of L1210 both in vivo and in vitro. Compound 7 strongly inhibited purine nucleoside phosphorylase (KI = 8.8 X 10-5 M), while compounds 8, 9, 6, and 12 were inactive. © 1983, American Chemical Society. All rights reserved
The Effect of Uniaxial Stress on the Spectrum of a Neutron-Coloured Sapphire Studied by Spectral Hole Burning
Cyclotrimerisation of Acetylene to Benzene Over Single Crystal Palladium and Gold/Palladium Surfaces and Over Supported Palladium Catalysts
Kinetic and spectroscopic studies of ethyne cyclisation to benzene over Pd and Pd/Au yield detailed information about the reaction mechanism. The existence of a critical ethyne coverage threshold for reaction is dramatically demonstrated by experiments using coadsorbed NO which compresses the reactant surface phase without itself participating in the reaction. Results obtained from both single crystal model systems and supported Pd catalysts clearly show that C4H4 is the crucial surface intermediate in the cyclisation reaction. Data obtained with well characterised Pd/Au single crystal systems reveal the sensitivity of this reaction to the electronic structure, atomic composition and morphology of the metal surface.</p