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C Fernandes

Publications and source records attributed to C Fernandes.

62 records · Page 4Linked to original sources
PubMedDate not supplied

Dramatic effect of the tridentate ligand on the stability of 99mTC "3 + 1" oxo complexes bearing arylpiperazine derivatives.

Mixed-ligand model complexes of general formula [(99m)Tc(O)(kappa(3)-PNX)(kappa(1)-SPh))] [X = O (1a), S (2a)] were prepared in a one-step procedure from [(99m)TcO(4)(-)] using stannous chloride as reducing agent. Stability studies and challenge experiments with glutathione showed that complex 2a presented promising features for pursuing animal studies. The activity in the brain (% dose injected/organ) at 5 min (0.14% +/- 0.03) and 120 min (0.11% +/- 0.02) pi encouraged the synthesis of several mixed-ligand "3 + 1" oxo complexes of general formula [M(O)(kappa(3)-PNS)(kappa(1)-SL))] (M = (99m)Tc, 3a-6a, Re, 3-6), in which the tridentate ligand is the heterofunctionalized phosphine 2-(diphenylphosphanyl)-N-(2-thioethyl)benzamide (PNS) and the co-ligands are different arylpiperazine derivatives (HSL1-HSL4). The (99m)Tc complexes have been characterized by comparison of their retention times in the HPLC chromatogram (gamma-detection) with the retention times of the analogous Re complexes (UV detection at 254 nm). The (99m)Tc complexes, obtained with radiochemical purity higher than 95%, after HPLC purification, are stable in saline, 0.01 M PBS (pH 7.4), rat plasma (4 h, 37 degrees C), and glutathione (10 mM solutions, 2h, 37 degrees C). Binding affinity and selectivity for 5-HT(1A) receptors (relative to the 5-HT(2A) receptor) were determined, complex 5 demonstrating the best values (IC(50) for the 5-HT(1A) 2.35 +/- 0.02 nM; competitor 5-HT(2A) 372 +/- 11 nM). Biodistribution and stability studies in mice indicated a preferred hepatobiliary excretion, a high in vivo stability, but a poor brain uptake.

Animals↗
PubMedDate not supplied

Synchronic signet ring carcinoma and adenocarcinoma complicating extensive and long-standing ulcerative colitis.

We report the case of a 38 year-old woman with extensive ulcerative colitis (UC) for 9 years that had consistently been under close endoscopic surveillance. She had had two previous severe attacks requiring hospital admission, with good response to intravenous steroids. In the last relapse, a total colonoscopy demonstrated extensive lesions of UC throughout the entire colon. Multiple biopsies taken every 3 cm revealed only low-grade dysplasia and lesions characteristic of UC. Due to medical therapy failure, the patient was submitted for proctocolectomy. Pathological examination of the resected specimen showed a signet ring carcinoma and a synchronic adenocarcinoma in the sigmoid colon, both undetected by colonoscopy and biopsies. The issue of surveillance in patients with extensive and long-standing UC is discussed.

Adenocarcinoma↗