On the relationship between children's perspective taking in complex scenes and their spatial drawing ability.

Depicting space and volume in drawings is challenging for young children in particular. It has been assumed that several cognitive skills may contribute to children's drawing. In the present study, we investigated the relationship between perspective-taking skills in complex scenes and the spatial characteristics in drawings of 5- to 9-year-olds (N= 121).

The expression, affinity purification and characterization of recombinant Pseudomonas exotoxin 40 (PE40) secreted from Escherichia coli.

Procedures have been devised for producing high yields of purified recombinant PE40, a protein important for the development of the anti-AIDS therapeutic, sCD4-PE40. PE40 is a truncated form of the bacterial toxin, Pseudomonas exotoxin A; it lacks the cell-binding domain, but retains domains II and III that are involved in membrane translocation and inhibition of protein synthesis in eukaryotic cells. Expression vectors in Escherichia coli encoding PE40 synthesized the product as a soluble protein under control of the T7 promoter.

Common surface epitope of Bartonella bacilliformis and Chlamydia psittaci.

A serosurvey revealed intense cross-reactivity between Bartonella bacilliformis and Chlamydia psittaci. One of the cross-reacting Bartonella antigens was identified as lipopolysaccharide which reacted with Bartonella as well as with Chlamydia serum antibodies. A monoclonal Bartonella antibody bound to Bartonella lipopolysaccharide as well as to the surfaces of Bartonella bacilliformis and Chlamydia psittaci.

Determination of 2-(4-isobutylphenyl)propionic acid in bulk drug and compressed tablets by reversed-phase high-performance liquid chromatography.

A reversed-phase liquid chromatographic method was developed for 2-(4-isobutylphenyl)propionic acid (IBPP) in bulk drug and compressed tablets containing 100-600 mg of drug per tablet. The chromatographic system consists of a microparticulate octadecylsilica column and a mobile phase of aqueous acetonitrile buffered with chloroacetic acid. Whole tablets are disintegrated, and the IBPP dissolved in a solution of the internal standard in mobile phase.

Analysis of steroids in bulk pharmaceuticals by liquid chromatography with light-scattering detection.

A detector for liquid chromatography based on light-scattering was evaluated to determine its application to pharmaceutical analysis. It performed adequately as a mass detector in liquid-solid chromatography of steroids, since response factors were equal to within 20%. The detection limit was approximately 0.

Determination of minoxidil in bulk drug and pharmaceutical formulations by ion-pairing high-performance liquid chromatography.

An ion-pairing liquid chromatographic method with UV detection is described for the determination of minoxidil in bulk drug, compressed tablet, and topical solution formulations. The chromatographic system consists of a microparticulate octadecylsilica column and a mobile phase composed of sodium dioctylsulfosuccinate in aqueous methanol (pH 3). The bulk drug and the topical solution samples are prepared by the dissolution of the drug in internal standard solution.

Reversed-phase high-performance liquid chromatography of catecholamines and their congeners with simple acids as ion-pairing reagents.

We have investigated the value of various common acids as ion-pairing reagents for high-efficiency separations of catecholamines and their metabolites in reversed-phase high-performance liquid chromatography. The retention of norepinephrine, alpha-methylnorepinephrine, dopamine, alpha-methyldopamine, L-dopa, alpha-methyldopa, dihydroxybenzylamine, epinephrine, carbidopa and DOPAC was measured in mobile phases composed of nitric, sulfuric, acetic and trichloroacetic acids at pH 2-5 and anion concentrations ranging from 5-500 mM. The solute capacity ratios were dependent on the hydrophobicity and concentration of the ion-pairing reagent and the pH of the mobile phase.