High-field 13C solid-state NMR studies of stream humic and fulvic acids with fast magic-angle spinning

Standard samples of stream humic and fulvic acids have been studied by high-resolution 13C solid-state NMR. The spectra have been recorded at a high (9.4 T) magnetic field using 1H-13C cross-polarization (CP) and proton high-power decoupling (HPDEC) with fast (up to 15 kHz) magic-angle spinning (MAS). The widths of the spectral lines decrease with increasing spinning rate. This is probably due to the overlap of spinning sidebands with resonances at low speeds and to a more effective averaging of anisotropic broadening at high speeds. However, fast MAS modulates the CP signal intensities, making quantitative analysis very difficult.

Case report: cyclosporin A-induced neurotoxicity

Acute encephalopathy is a recognized toxic effect of Cyclosporin A (CsA) in organ transplantation recipients. A 16-year-old girl presented with acute encephalopathy 2 weeks after CsA and methylprednisolone medication for idiopathic uveitis. Magnetic resonance imaging showed cortical and white matter occipital changes, which were not visible 2 months later. With expanding indication for CsA use, an increasing number of neurotoxic cases are to be expected.

Subtyping of alkylated human orosomucoid: evidence for a duplicated gene, ORM1*F2S

Isoelectric focusing of human orosomucoid (ORM) was studied following different sample treatment. It is shown that: (i) alkylation with iodoacetamide leads to a drastic change in the isoelectric point (pI) of both ORM1 F2 and ORM2 A gene products and greatly improves the discrimination between ORM1 F1 and ORM1 F2; (ii) previous reduction of the molecule with dithiothreitol partially inhibits the pI transitions with resultant artifactual ORM1 F1F2S patterns that correspond in most cases to F2S phenotypes. With the technique now described, the persistence of three ORM1 gene products was found in only one individual and the segregation analysis is consistent with the existence of a rare ORM1*F2S haplotype.

Separation of human alloalbumin variants by isoelectric focusing

A technique for the separation of human alloalbumin variants by means of isoelectric focusing in the presence of 8M urea and 60 mM L-serine is described. The potential usefulness of this technique in the detection and classification of genetic heterogeneity at the albumin locus is demonstrated by the differentiation of three human alloalbumin variants of European origin.

Gene dosage evidence for the regional assignment of GPT (glutamate-pyruvate transaminase; E.C. 2.6.1.2) locus to 8q24.2----8qter

The results of a study on the expression of GPT (glutamate-pyruvate transaminase; E.C. 2.6.1.2) in a child with a partial trisomy of chromosomes 8 and 14 are presented. A gene dosage effect supporting the regional assignment of the GPT locus to 8q24.2----8qter is demonstrated.

Formal genetics of esterase D (EC 3.1.1.1): evidence for a sex-phenotype association

The formal genetics of esterase D (EC 3.1.1.1) was studied in family data and mother/child pairs. A general agreement with mendelian expectations was found. However, a significant sex-phenotype association was detected in families from northwestern Portugal as well as in mother/child pairs and family data from southwestern Germany.