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991.
C Guertner BJ Krause H Klepzig G Herrmann S Lelbach EK Vockert A Hartmann FD Maul TW Kranert E Mutschler 《Canadian Metallurgical Quarterly》1995,22(5):443-452
Cardiac transplantation entails surgical disruption of the sympathetic nerve fibres from their somata, resulting in sympathetic denervation. In order to investigate the occurrence of sympathetic re-innervation, neurotransmitter scintigraphy using the norepinephrine analogue iodine-123 metaiodobenzylguanidine (MIBG) was performed in 15 patients 2-69 months after transplantation. In addition, norepinephrine content and immunohistochemical reactions of antibodies to Schwann cell-associated S100 protein, to neuron-specific enolase (NSE) and to norepinephrine were examined in 34 endomyocardial biopsies of 29 patients 1-88 months after transplantation. Anterobasal 123I-MIBG uptake indicating partial sympathetic re-innervation could be shown in 40% of the scintigraphically investigated patients 37-69 months after transplantation. In immunohistochemical studies 83% of the patients investigated 1-72 months after transplantation showed nerve fibres in their biopsies but not positive reaction to norepinephrine. Significant norepinephrine content indicating re-innervation could not be detected in any biopsy. It was concluded that in spite of the lack of norepinephrine content there seemed to be immunohistological and scintigraphic evidence of sympathetic re-innervation. An explanation for this contradictory finding may be the reduced or missing norepinephrine storage ability compared to the restored uptake ability of regenerated sympathetic nerve fibres. 相似文献
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RE Shefer BJ Hughey RE Klinkowstein MJ Welch CS Dence 《Canadian Metallurgical Quarterly》1994,21(7):977-986
The recent development of low energy accelerators for positron emission tomography has necessitated the development of new targets for 13N production. 12C(d,n)13N reaction yields in graphite at low deuteron beam energies (0.8-3.2 MeV) are presented and a new technique for the in situ extraction of 13N activity from solid graphite and subsequent conversion to [13N] ammonia is described. The target is windowless and is reusable for multiple isotope production runs. This technique utilizes radio frequency induction heating to rapidly heat the graphite to combustion temperatures in an O2 gas stream. The conversion of activity induced in the target to [13N] ammonia in under 10 min with an overall decay-corrected efficiency of 45% is reported. 相似文献
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DH Boschelli Z Wu SR Klutchko HD Showalter JM Hamby GH Lu TC Major TK Dahring B Batley RL Panek J Keiser BG Hartl AJ Kraker WD Klohs BJ Roberts S Patmore WL Elliott R Steinkampf LA Bradford H Hallak AM Doherty 《Canadian Metallurgical Quarterly》1998,41(22):4365-4377
Screening of a compound library led to the identification of 2-amino-6-(2,6-dichlorophenyl)-8-methylpyrido[2,3-d]pyrimidine (1) as a inhibitor of the platelet-derived growth factor receptor (PDGFr), fibroblast growth factor receptor (FGFr), and c-src tyrosine kinases (TKs). Replacement of the primary amino group at C-2 of 1 with a 4-(N,N-diethylaminoethoxy)phenylamino group yielded 2a, which had greatly increased activity against all three TKs. In the present work, variation of the aromatic group at C-6 and of the alkyl group at N-8 of the pyrido[2,3-d]pyrimidine core provided several analogues that retained potency, including derivatives that were biased toward inhibition of the TK activity of PDGFr. Analogues of 2a with a 3-thiophene or an unsubstituted phenyl group at C-6 were the most potent inhibitors. Compound 54, which had IC50 values of 31, 88, and 31 nM against PDGFr, FGFr, and c-src TK activity, respectively, was active in a variety of PDGF-dependent cellular assays and blocked the in vivo growth of three PDGF-dependent tumor lines. 相似文献