High-performance liquid chromatographic enantioseparation of bicyclic 1,3-amino alcohols.

Different high-performance liquid chromatographic methods were developed for the separation and identification of enantiomers of diendo- and diexo-3-aminobicyclo[2.2.1]heptane-2-methanol and diendo- and diexo-3-amino-bicyclo[2.2.1]hept-5-ene-2-methanol derivatives. Direct separation was carried out on a naphthylethyl carbamate-derivatized beta-cyclodextrin (Cyclobond I 2000 SN) stationary phase, which was used in the polar-organic mode. This allowed the simultaneous separation of stereoisomers of alcohol and ester analogs of the bicyclic 1,3-amino alcohols. Alternatively, the derivatization of amino alcohols on the amino group with 1-fluoro-2,4-dinitrophenyl-5-L-alanine amide produced diastereomers which were separable with high resolution (Rs>5-10) on a LiChrospher RP-18 stationary phase. The order of elution of the enantiomers was determined by both direct and indirect methods.

[The cerebral cortex blood supply in calves in relation to the cerebrocortical necrosis syndrome]. / Krevní zásobení mozkové kury telete ve vztahu k syndromu cerebrokortikální nekrózy (CCN).

A number of methods (postmortal injection with China ink-gelatine, plastic substances, preparation, corrosive casts, angiography) were tested to study the supply of blood to the cerebrum with special regard to blood neopallia. The study was performed on 19 calves of the Bohemian Spotted breed and on crossbreeds from the late foetal period until the age of four months post natum. The cerebral arteries have a relatively high plasticity. The anastomotic system undergoes its morphological, functional and topographic differentiation in the central and peripheral region. Some data on a. ethmoidalis interna, a. communicans rostralis and a. marginalis are corrected and a. cerebri rostralis media and a. meningea rostralis are given a new description. The distribution areas of cortex arteries whose contact regions correspond with the location of lesions in CCN-affected calves are delimited. The obtained results are of substantial importance for the study and understanding of the pathogenesis of changes in cases of the occurrence of the so-called bovine CCN syndrome, which is gaining urgency mainly in large stocks.