111In–L–LDL and 153Gd–L–LDL as radiotracers for detection of AR4‐2J rat pancreatic tumors

Pancreatic cancer has an extremely poor prognosis, due, in part, to lack of methods for early diagnosis. The present study was designed to evaluate the potential of labeling low‐density lipoprotein (LDL) with a radionuclide using a lipid chelating agent, bis(stearylamide) of diethylenetriaminepentaacetic acid (L), to detect pancreatic tumors by gamma‐scintigraphy. Previous studies indicated that the difficulty of visualization of pancreatic tumors was due to their poor vascularization. This study compares the ability of two radiotracers, ¹¹¹In–L–LDL and ¹⁵³Gd–L–LDL to target highly vascularized rat pancreatic tumors (AR4‐2J) implanted in nude mice. Biodistribution studies showed that the tumor uptake of ¹¹¹In–L–LDL and ¹⁵³Gd–L–LDL tracers was twofold and fivefold higher respectively than with the controls (¹¹¹In citrate and ¹⁵³Gd citrate respectively). These tracers would thus be suitable for scintigraphic imaging. We show here that LDL could be employed as a delivery system for tracers such as ¹¹¹In or ¹⁵³Gd when these two radionuclides are complexed by a lipid‐chelating anchor, and that ¹¹¹In–L–LDL and ¹⁵³Gd–L–LDL enabled better visualization of the pancreatic tumor tissues, with a better result with ¹⁵³Gd–L–LDL. Copyright © 2004 John Wiley & Sons, Ltd.     

Non planéité de cyclopenténones substituées analyse conformationnelle par résonance magnétique nucléaire

The stereochemistry of substituted cyclopent-2-en-1-ones was studied by NMR. The existence of non-planar rings is indicated and conformational analysis, based principally upon examination of the coupling constants enables the conformational population to be estimated; trans dihalogeno derivatives, for example, occur predominantly in the diaxial form.     

Application d'un detecteur a semi-conducteur a l'analyse systematique de l'aluminium

Résumé Après une irradiation neutronique de 7 jours dans un flux de 3·10¹² n·cm⁻²·sec⁻¹, une trentaine d'éléments peuvent être dosés sans séparation chimique dans des échantillons d'aluminium de diverses provenances. Les modalités de mesure et de calcul des radioactivités sont précisées et nous indiquons les limites de détection obtenues. Elles sont comprises entre 5·10⁻² et 5·10⁻⁶ μg/g selon les éléments recherchés. Pour certains d'entre eux (Fe, Zn, Zr) ces limites peuvent être améliorées par une séparation chimique simple.     

Far U.V. absorption spectra of manganese halides between 20 and 67 eV.

The absorption spectra of evaporated thin films of MnF₂, MnCl₂, MnBr₂ have been measured in the energy range 20–67 eV. The onset of the absorption of 3p Mn²⁺ is about 50 eV. At lower energies, the structures may be attributed to transitions from 2s F^-, 4s Br^- and 3d Mn²⁺ levels.     

Non-equivalence Magnetique en Resonance Nucleaire—IV. Influence de Plusieurs Types de Dissymetries sur les Deplacements Chimiques et les Couplages Relatifs a des Systemes ?O?CH2?CH3 et ?S?CH2?CH3

Magnetic non-equivalence of methylenic protons in A? CH₂? CH₃ groups were studied for several types of compounds. Results are compared with respect (1) to the nature of heteroatom A:A = O and A = S and (2) to the structure of the local dissymmetry element: asymmetric carbon, ketal group and allenic system. Influence of substitution is discussed in relation to conformational problems. Furthermore a variation of the methylene geminal coupling constant with substituents of carbon α to OEt is observed.     

Analysis of the ν3 band of 12CH3D at 7.6 μm

The previously reported (J. Mol. Spectrosc.68, 195–222 (1977)) study of the CH₃D spectrum occurring at 1033–1270 cm^?1 which was mainly concerned with the ν₆ fundamental has now been extended to cover the region 1270–1420 cm^?1. In all, 342 transitions belonging to the ν₃ band are now assigned. Both the ν₃ and ν₆ bands are processed simultaneously taking into account of the Coriolis interaction between them, and the fitting of all the experimental data led to 21 significant spectroscopic constants for the states v₆= 1 and v₃ = 1 of CH₃D.     

Edge-forwarding index of star graphs and other Cayley graphs

We present a technique for building, in some Cayley graphs, a routing for which the load of every edge is almost the same. This technique enables us to find the edge-forwarding index of star graphs and complete-transposition graphs.     

Synthése de la pyrido[4,3-e]-as-triazine

This communication describes the synthesis of a new heterocycle, pyrido[4,3-c]-as-triazine, its 3-methyl derivative, and their nmr spectral data.