[Pharmacokinetics of rectal absorption of amodiaquine in rabbits]. / Az amodiaquin rektális felszívódásának farmakokinetikai vizsgálata.

Experimental investigations were made in rabbits to examine the rectal absorption of antimalarial amodiaquine [AQ]. To calculate the pharmacokinetic parameters AQ was administered orally (20 mg/kg) and rectally (20 mg/kg) to the animals and the blood concentrations of the drug were controlled during a time interval of 120 hours with help of spectrofluorometric method. The pharmacokinetic analysis was performed by use of two-compartment open model system. Time-concentration curves were fitted to the data in experiments by computer program (MEDUSA) and the kinetic parameters were given in the Tables 1. and 2. It was established that rectally administered AQ resorbed not only from solution but from suppository, too. The bioavailability of the rectal preparations relating to the oral dosage form was 63.35% and 68.70%, respectively. The most appropriate drug delivery system for rectal application had been selected previously.

TEM-tomography of FAU-zeolite crystals containing Pt-clusters.

A method for preparing ultrathin sections (- 20 nm) of inorganic solids has been developed using ultramicrotomy of resin-embedded crystal fragments. Undamaged crystals, oriented along a crystallographic direction, could be imaged with transmission electron microscopy (TEM) at a resolution better than 0.5 nm. The true internal structure of the crystals could be investigated by imaging the second in a series of at least three consecutive ultrathin sections. Such TEM-tomography proved that Pt-ion exchanged FAU zeolite crystals, after reduction and oxidation, are occupied internally and randomly of large platinum clusters mainly in the {111-twin planes. TEM-tomography could be useful in man made nanostructures like semiconductors, epitaxial thin films, hard metal coatings, ceramics, catalysts, and biomaterials.

Behavioral observations and measurements of aerial pheromone in a mating disruption trial against pea mothCydia nigricana F. (Lepidoptera, Tortricidae).

Synthetic sex pheromone of the pea mothCydia nigricana. (E,E)-8,10-dodecadien-1-yl acetate (E8,E10-12 : Ac), was applied in a 3-ha pea field at a rate of 17 g/ha, in two different dispenser formulations. Aerial concentrations within pea canopy, as determined by a field electroantennogram (EAG) apparatus, were 2 and 3 ng/m(3) in the two dispenser treatments. The validity of the EAG measurements was corroborated by sampling of field air, followed by gas chromatographic quantification ofE8,E10-12 : Ac. Males were attracted to fresh dispensers releasingE8,E10-12 : Ac plus less than 2% of the antagonisticE, Z; Z, E; andZ, Z isomers. Two days after placement, the proportion of these isomers had increased to 6%. Males were then no longer attracted to the dispensers, but were observed to fly out of the treated field. Male attraction to calling females was almost entirely suppressed, and attraction to traps baited with synthetic pheromone was significantly reduced. Larval infestation in the pheromone-treated field was 2%, compared to 36% in a control field.

Purification of proteins by the use of hydrophobic zeolite Y.

Hydrophobic zeolite Y can be used as a fast and efficient and inexpensive matrix in the purification of proteins from crude extracts. Preferably the zeolite can be used in the first purification step, replacing the commonly used precipitation techniques with (NH4)2SO4 or ethanol. The time required for the zeolite prefractionation was a few hours compared to the much more time consuming precipitation procedure which demands centrifugation and subsequent dialysis. Proteins can be absorbed on the zeolite either in order to remove undesired proteins or to be subsequently eluted from the zeolite in order to achieve purification and concentration. Removal of undesired proteins is exemplified by the purification of horseradish peroxidase from a crude extract. The zeolite procedure enhanced the specific activity five times and provided a yield similar to that which was obtained by the use of standard procedures, (NH4)2SO4 fractionation and ion-exchange chromatography. Binding and subsequent elution of proteins from the zeolite is exemplified by the purification of monoclonal antibodies from hybridoma culture supernatants. Proteins were desorbed from the zeolite by the use of polyethylene glycol 600 and this procedure yielded a purification factor of 5.

DNA packing in chromatine, a manifestation of the Bonnet transformation.

The packing of DNA is described using the formalism of differential geometry. Winding of the DNA double helix around the histone 2-5 octamer forming a nucleosome and the condensation of the so-formed bead-on-a-string chromatine aided by histone 1 is interpreted as two consecutive isometric, i.e. Bonnet, transformations. The DNA double helix can be approximated to a helicoid which can be transformed isometrically to a catenoid, an approximation of the nucleosome. Owing to the organization of the histone octamer the extended chromatine takes a helicoidal shape allowing a second Bonnet transformation to consummate the condensation into a chromatine fibre.