Synthesis and biological evaluation of <Superscript>99m</Superscript>Tc labeled aryl piperazine derivatives as cerebral radiotracers

The aim of this study is to develop cerebral radiotracers for central nervous system receptors imaging. The synthesis, characterization and biological evaluation of two aryl piperazine ^99mTc-radiocomplexes based on the piano stool motif [CpM(CO₃)] (Cp = cyclopentadienyl, M = ^99mTc/Re) is reported. The ^99mTc-radiocomplexes were obtained quickly (time < 5 min) with high radiochemical yields. The ^99mTc-radiocomplexes characterized by high performance liquid chromatography comparison with the rhenium surrogates have both a suitable lipophilicity and are able to cross the blood brain barrier with 0.43 ± 0.05 and 1.96 ± 0.06% ID/g of brain uptake, at 10 min post injection.     

Convenient synthesis of substituted benzo[e][1,2,4]- or [d][1,2,6]oxadiazepines,benzo[f][1,3,5]triazocines from N-aryliminoesters

We report herein a short and efficient synthesis of benz[e][1,2,4]- or [d][1,2,6]oxadiazepines and benzo[f][1,3,5]triazocines from easily prepared N-aryl iminoesters. The strategy involves a bis-nucleophile reagent (hydroxylamine or guanidine) that promotes a one-step ring closure from the starting functionalized iminoesters.     

On the Diffusion in a Lattice Gas Model: Group-Theoretic Approach

Motivated by some recent results concerning the model of a noninteracting one-dimensional lattice gas with an order preservation of particles where multiple occupancy of the sites is not excluded, we give new symmetries and new reductions of the corresponding continuum nonlinear partial differential equation. Closed-form analytic solutions are found.     

Solvent selection in ultrasonic-assisted emulsification microextraction: Comparison between high- and low-density solvents by means of novel type of extraction vessel

There are numerous published reports about dispersive liquid phase microextraction of the wide range of substances, however, till now no broadly accepted systematic and purpose oriented selection of extraction solvent has been proposed. Most works deal with the optimization of available solvents without adequate pre-consideration of properness. In this study, it is tried to compare the performances of low- and high-density solvents at the same conditions by means of novel type of extraction vessel with head and bottom conical shape. Extraction efficiencies of seven basic pharmaceutical compounds using eighteen common organic solvents were studied in this work. It was much easier to work with high-density solvents and they mostly showed better performances. This work shows that although exact predicting the performance of the solvents is multifaceted case but the pre-consideration of initial selection of solvents with attention to the physiochemical properties of the desired analytes is feasible and promising. Finally, the practicality of the method for extraction from urine and plasma samples was investigated.     

Nandrolone decanoate increases the volume but not the length of the proximal and distal convoluted tubules of the mouse kidney

Anabolic androgenic steroids are widely used by athletes for increasing their muscle mass. These drugs are also used by some patients with chronic renal disease. But the effect of these drugs on the renal structure has received less attention. To investigate which parts of the kidney are affected by these drugs, mice kidneys were studied stereologically after injection of nandrolone decanoate (ND), an anabolic androgenic steroid. The treated group received nandrolone decanoate intraperitoneally (solved in olive oil) in doses of 3mg/kg of body weight and administered in one, two and three doses, respectively, in the first, second and third week of treatment. The mice in the control group received an olive oil solution. One week after the last injection, the mice were anaesthetized and their kidney removed. The analysis of data revealed that the weight of kidney was increased approximately 30% (p < or = 0.006) and its volume increased approximately 25% (p < or = 0.02) in ND treated mice in comparison with the control group. The volume of the cortex increased in ND treated animals approximately 44% (p < or = 0.006). Proximal convoluted tubules (PCT) and distal convoluted tubules (DCT) volume increased approximately 25% (p < or = 0.02) and approximately 68% (p < or = 0.02) in ND treated mice. The volume of glomeruli, other ducts, connective tissues, vessels and the length of PCT, DCT, collecting and Henle's ducts and vessels did not show significant differences. CONCLUSION: ND can increase the volume of the renal cortex and its two main parts, i.e. PCT and DCT in mice.     

An improved electrochemical method for the synthesis of some benzofuran derivatives

Electrochemical oxidation of catechol and some 3-substituted catechols (1a--c) has been studied in the presence of 2-chloro-5,5-dimethyl-1,3-cyclohexanedione (3) in aqueous solution using cyclic voltammetry and controlled-potential coulometry. The results indicate that the quinones derived from catechols (1a--c) participate in a Michael addition reaction with 2-chloro-5,5-dimethyl-1,3-cyclohexanedione (3) with consumption of only two electrons per molecule of (1a--c) to from the corresponding benzoforans (10a--c). The electrochemical synthesis of benzofurans has been successfully performed at a carbon rod electrode and in an undivided cell with high yields and purity.     

Multigrid solution of the Poisson—Boltzmann equation

A multigrid method is presented for the numerical solution of the linearized Poisson–Boltzmann equation arising in molecular biophysics. The equation is discretized with the finite volume method, and the numerical solution of the discrete equations is accomplished with multiple grid techniques originally developed for twodimensional interface problems occurring in reactor physics. A detailed analysis of the resulting method is presented for several computer architectures, including comparisons to diagonally scaled CG, ICCG, vectorized ICCG and MICCG, and to SOR provided with an optimal relaxation parameter. Our results indicate that the multigrid method is superior to the preconditioned CG methods and SOR and that the advantage of multigrid grows with the problem size. © 1993 John Wiley & Sons, Inc.