[en] Human placental β-hexosaminidase A was labeled with ¹²⁵iodine to high specific activity with the retention of conformational integrity as judged by the retention of enzymatic activity. The oligosaccharide structure also appeared to be intact since the labeled enzyme was cleared from the circulation of the rat with a half-life identical to that of the unlabeled enzyme and an excess of unlabeled enzyme effectively blocked the clearance of the labelled form. Furthermore, the pattern of inhibition of clearance of the native and labeled enzymes by asialofetuin and mannans was identical. The useful and mild procedure for labeling enzymes may be of general importance in the preparation of enzymes for metabolic studies in normal animals and animal models of genetic lysosomal storage disorders. (Auth.)

[en] The labelling technics have been a big support for the advances reached in Biology Research. The use of radioisotopes has been essential for these technics, but alternative nonradioactive labelling technics have developped during the last few years. These nonradioactive technics are as sensitive and accurate as the radioactive ones, but without irradiation risk. This article report presents a short review about both types of technics, explaining their basis, making comparisons between them and discussing about the advantages and disadvantages associated to them

[en] This volume contains the typescript texts of six plenary lectures plus short (ca. 2 pp) versions of a very large number of papers from the Second International Symposium, held in Kansas City in 1985; author and subject indexes

[en] The juvenoid analog 2-(4-(ethoxycarbamato)ethoxy)benzyl)-1-cyclohexane ethylene acetal (W 328) was labelled with ³H in the benzyl position by the CESG method. ³H-NMR revealed the stereoselectivity of the labelling. The results are compared with data published in the literature and discussed in the terms of stereoelectronic requirements. (author) 2 figs., 7 refs

[en] At the - Departement d'Ingenierie et d'etudes de proteines (Deip) of the CEA more than seventy researchers are working hard to understand the function of proteins. For that they use the molecular labelling technique (F.M.)

No abstract available

No abstract available

[en] The synthesis of two novel radiolabelled estrogen derivatives, [¹²⁵I](E)-3-methoxy-17α-iodovinylestra-1,3,5(10),6-tetraen-17β-ol (E[¹²⁵I]IVDE) and [¹²⁵I](Z)-3-methoxy-17α-iodovinylestra-1,3,5(10),6-tetraen-17β-ol (Z[¹²⁵I]IVDE), was carried out aiming to study the influence of the introduction of a C6-C7 double bond on the biological properties of the estradiol molecule. 3-Methoxyestra-1,3,5(10),6-tetraen-17-one was synthesised starting from a suitably protected estrone and subsequently converted into the 17α-ethynyl derivative. The radioiodinated derivatives were stereoselectively formed by radioiododestannylation of the corresponding tributylstannyl precursors. The biodistribution of the novel [¹²⁵I]iodovinylestradiol derivatives was evaluated in immature female mice. Biological data indicated that the Z-isomer, owing to its higher in vivo uptake by the target tissue, has the preferable configuration for further development of similar compounds for estrogen receptor detection.

[en] Coordination chemistry of technetium 99 applied to biology and medicine. Rational conceptualisation of new photon emitter probes for in vivo investigations with technetium 99m (on the tracer scale) requires the coordination chemistry of ponderable technetium 99 isotope. Physicochemical and structural studies carried out on technetium 99 complex models enable us to identify predictive parameters involved in radiopharmaceutical in vivo tropism (specificity) for the target bodies. In addition, this work leads to the development and control of a new technetium complexation protocol under physiological conditions (pH ∼ 7.4 and T < 45 deg. C) in order to label bio-vectors without denaturing them. (author)

[en] α-Cyano-3-phenoxybenzyl 2, 2, 3, 3-tetramethylcyclopropanecarboxylate (fenpropathrin), a new potent synthetic pyrethroid, was labelled with carbon-14 at the cyclopropyl group for studies on its metabolism in mammals, fishes, plants and soils. Condensation of potassium cyanide-¹⁴C (2) with 1,3-diphenyl-2-thiourea (3) in the presence of basic lead carbonate gave 1-cyano-¹⁴C-N,N'-diphenylformamidine (4). Reduction of 4 followed by hydrolysis with barium hydroxide afforded glycine-2-¹⁴C (6). Esterification of 6 with ethanol in the presence of anhydrous hydrogen chloride gave ethyl glycinate-2-¹⁴C hydrochloride (7). Diazotization of 7 followed by condensation with 2, 3-dimethyl-2-butene yielded ethyl 2, 2, 3, 3-tetramethylcyclopropane-1-¹⁴C-carboxylate (8). Hydrolysis of 8 gave 2, 2, 3, 3-tetramethylcyclopropane-1-¹⁴C-carboxylic acid (9), which was esterified with α-cyano-3-phenoxybenzyl bromide (10) to afford fenpropathrin(cyclopropyl-1-¹⁴C) (1) in 13 % yield from 2. (author)