To improve current angiogenic gene therapy with a vascular endothelial growth factor (VEGF)-encoding plasmid (Baumgartner et al. Circulation 1998; 97: 1114-23 [1]; Kusumanto et al. Fifth Annual Meeting of the American Society of Gene Therapy, Boston, 2002, Abstr. 621 [2]), we have generated a combination plasmid, encoding the VEGF gene and the thymidine phosphorylase (TP, also known as platelet-derived endothelial growth factor (PD-ECGF) or gliostatin (GLS)) gene: phVEGF165-TP.MB. Upon transfection in COS-7 cells both gene products were expressed and functional as shown by Western blots, ELISAs and bioassays. Culture supernatants of COS-7 cells transfected with this plasmid were able to induce endothelial proliferation. In an in vitro angiogenesis assay with recombinant proteins, TP was able to increase VEGF-induced tube formation. The phVEGF165-TP.MB plasmid is therefore a promising candidate for in vivo angiogenesis studies.
We have developed a routine capillary gas-chromatographic profiling method for simultaneous quantitative determination of the tert-butyldimethylsilyl derivatives of homovanillic acid, vanilmandelic acid, 3-methoxy-4-hydroxyphenylethylene glycol, and 3,4-dihydroxyphenylacetic acid and the estimation of 5-hydroxyindole-3-acetic acid in urine. The method is useful for diagnosis and followup of patients with functional tumors characterized by increased urinary excretion of metabolites originating from the metabolism of tyrosine and tryptophan--e.g., neuroblastoma, pheochromocytoma, carcinoid, and melanoma. It may also be applicable in pharmacokinetic studies of administered aromatic amino acids (parkinsonism, mental diseases, loading tests) and for diagnosis and followup of patients with inborn errors of metabolism that are characterized by organic aciduria (for instance, tyrosyluria and phenylketonuria).
SUMMARYThe preparation of CD -labelled 3-methoxytyramine, normetanephrine and metanephrine from their parent catecholamines is described. The syntheses include N-maleylation, 0-methylation by dimethylsulfate-D6, removal of the protecting group by acid hydrolysis and partial purification of the reaction product. Examples of the use of the deuterium labelled 0-methylated catecholamine metabolites as internal standards for the ammonia chemical ionisation mass fragmentographic determination of their naturally occurring analogs in urine, are given.
3Key Words: CD -labelled-3-0-methylated catecholamine metabolites; mass 3 fragmentography .
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