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The research on the change of antibacterial activity due to the introduction of a nitro group in the benzene nucleus linked at the heterocyclic nitrogen of N-phenylsulfanilamidopyrazoles is continued with the preparation of 1-(2'-nitrophenyl)-4-sulfanilamidopyrazole (IIa: -NO2 in 2'; R=-H), 1-(3'-nitrophenyl)-4-sulfanilamidopyrazole (IIb: -NO2 in 3'; R=-H) and 1-(4'-nitrophenyl)-4-sulfanilamidopyrazole (IIc: -NO2 in 4'; R=-H). By analogy with the results obtained for the derivatives of 4-sulfanilamidopyrazole (I) previously prepared, enhancement of the bacteriostatic activity in vitro against S. aureus and E. coli, have been observed in almost all the cases, especially with 1-(3-nitrophenyl)-4-sulfanilamidopyrazole (IIb).

A monoclonal antibody to carcinoembryonic antigen (CEA) (F023C5), belonging to IgG1 class, was obtained by cell fusion technique. Preliminary screening on different tissues was performed with immunoperoxidase staining, which showed good specificity of the antibody for gastric and colorectal carcinomas. F(ab')2 fragments were subsequently prepared and labeled with 131I and 111In. After immunoreactivity check the radiopharmaceuticals were injected intravenously. Sixteen patients with 22 primary or secondary localizations of colorectal carcinoma were studied following the recommendations of the ethical Committee of the Istituto Nazionale Tumori, Milan, Italy. Serial scans were performed after injection of the two radioactive reagents. In vivo pharmacokinetics of the compound was studied. Radioactivity level in surgical specimens was measured, and immunostaining was performed. All tumors were found to express the antigen. Eleven out of 12 tumor localizations of the gastrointestinal tract and three out of ten liver metastases were imaged. Specificity of tumor uptake was assessed by simultaneous injection of an irrelevant antibody.

Several monoclonal antibodies (MAbs), reactive with tumor-associated antigens, selectively persist on tumor sites in vivo for many days. If biotinylated, such highly specific tags on tumor cells could become targets for radioactive avidin, administered after suitable intervals. The proposed strategy is based on a number of assumptions concerning the ability of avidin to preserve its biological properties in heterologous in vivo environments, on its lack of toxicity and on its biodistribution. A preliminary study has been carried out in rabbits, using biotinylated nitrocellulose and polystyrene targets. The results of this study indicate that in rabbits 1) avidin can be administered i.v. and i.p. without adverse reactions, 2) it does not show any preferential localization, 3) it is eliminated with a biological half-life of 24 hr, 4) its biological properties are not impaired by in vivo conditions, since it accumulates at biotinylated targets only, 5) CEA-bearing targets can be biotinylated in vivo by biotin-labelled anti-CEA MAbs and 6) the biotin-avidin chain can be further extended in vivo since bound avidin is still able to bind biotinylated radioactive proteins.

Atherosclerotic lesions can be detected by several methods, such as angiography, B-mode ultrasonography, computed tomography and magnetic resonance. Radioisotopic techniques, recently introduced by using radiolabelled platelets and LDL (low-density lipoproteins), can give more informations about the "metabolic activity" of atherosclerotic lesions. The aim of this study was to detect atherosclerotic lesions in 7 hyperlipemic patients using autologous apo-B containing lipoproteins labelled with 131I in order to evaluate different functional patterns of these lesions. Carotid and femoral accumulations of this radiocompound were detected in the majority of patients. The method appears promising for evaluating the "in vivo" relationships between lipoproteins, which are involved in the pathogenesis of atherosclerosis, and the vessel wall.

A report is given of the variations in bacteriostatic activity on introduction of a hydrophilic group, the hydroxyl group (-OH), at positions 2',3' and 4' of the phenyl group linked to the heterocyclic nitrogen os 1-phenyl-5-sulfanilamidopyrazole (I: R = -H) and of 1-phenyl-3-methyl-5-sulfanilamidopyrazole (II: R = -H). The substances prepared for this purpose: 1-(hydroxyphenyl)-5-sulfanilamidopyrazoles (Ia)(Ib))(Ic)(-OH at 2', 3',4') and 1-(hydroxyphenyl)-3-methyl-5-sulfanilamidopyrazoles (IIa)(IIb)(IIc)(-OH at 2',3'4') in vitro tests of bacteriostatic activity against strains of S. aureus and E. coli gave the following results: See journal for results.