The 11th nerve syndrome. Accessory nerve palsy or adhesive capsulitis?

The 11th nerve syndrome classically involves the majority of patients undergoing neck dissections even when the accessory nerve is preserved. A preliminary analysis of our data of 31 of 44 patients who underwent neck dissections from a prospective study showed numerous findings of shoulder disability that are not attributable to accessory nerve palsy but are well described by the syndrome of adhesive capsulitis of the glenohumeral joint. At 1 month postoperatively, although accessory nerve palsy symptoms were common, adhesive capsulitis symptoms were significant.

Catalytic properties of the human cytochrome P450 2E1 produced by cDNA expression in mammalian cells.

A full-length cDNA encoding human cytochrome P450 2E1 was expressed in mammalian cell lines using the vaccinia virus expression system. Immunoblot analysis showed that the expressed protein reacted with a polyclonal antibody against rat 2E1 and comigrated with P450 2E1 from human liver microsomes. P450 2E1 expressed in Hep G2 cells, a human cell line which contains both cytochrome b5 and NADPH:P450 oxidoreductase, was able to metabolize several known P450 2E1 substrates: N-nitrosodimethylamine (NDMA), N-nitrosomethylbenzylamine (NMBzA), p-nitrophenol, phenol, and acetaminophen.

Primary structure, chromosomal localization, and functional expression of a voltage-gated sodium channel from human brain.

A cDNA library derived from human cerebral cortex was screened for the presence of sodium channel alpha subunit-specific clones. Ligation of three overlapping clones generated a full-length cDNA clone, HBA, that provided the complete nucleotide sequence coding for a protein of 2005 amino acids. The predicted structure suggests four homologous repeats and exhibits greatest homology and structural similarity to the rat brain sodium channel II.

Nature of N-nitrosodimethylamine demethylase and its inhibitors.

The present study was undertaken to examine the nature of the low Km (KmI) form of rat liver microsomal N-nitrosodimethylamine demethylase (NDMAd) and its inhibition by organic compounds which are commonly present in the assay mixture. Using radiometric and colorimetric assay methods with an NADPH-generating system consisting of 0.4 mM NADP, 10 mM glucose-6-phosphate, and glucose-6-phosphate dehydrogenase (0.

Monoclonal antibodies to ethanol-induced rat liver cytochrome P-450 that metabolizes aniline and nitrosamines.

Hybridomas were prepared from mouse myeloma cells and spleen cells derived from female BALB/c mice that had been immunized with a partially purified ethanol-induced rat liver cytochrome P-450 (P-450et). Monoclonal antibodies (MAbs) produced by the hybridomas were screened for binding to P-450et with a radioimmunoassay. Thirty-one independent hybrid clones produced MAbs that had a high affinity for P-450et.

Metabolism and activation of N-nitrosodimethylamine by hamster and rat microsomes: comparative study with weanling and adult animals.

It has been reported that hamster liver preparations are more effective for the metabolic activation of N-nitrosodimethylamine (NDMA) to a mutagen than rat liver preparations. The enzymatic basis for this phenomenon, however, has not been clearly elucidated. The present study was undertaken to examine the enzymology of NDMA metabolism by different hepatic subcellular fractions prepared from hamsters and rats of two different ages, and to investigate the correlation between the metabolism and the activation of NDMA to a mutagen for Chinese hamster V79 cells.

Enzymatic mechanisms in the metabolic activation of N-nitrosodialkylamines.

The metabolism of several N-nitrosodialkylamines was studied using rat liver microsomes and purified cytochrome P450 isozymes in a reconstituted monooxygenase system. With purified acetone/ethanol-inducible cytochrome P450 (P450ac), high N-nitrosodimethylamine (NDMA) demethylase activity was observed. Cytochrome b5 was also involved in NDMA metabolism by decreasing the Km of NDMA demethylase.

Acetone-inducible cytochrome P-450: purification, catalytic activity, and interaction with cytochrome b5.

A procedure was developed for the purification of an acetone-inducible form of cytochrome P-450 (P-450ac) to electrophoretical homogeneity from liver microsomes of acetone-treated rats. The P-450ac preparation containing 16.0 to 16.

Metabolism of nitrosamines by cytochrome P-450 isozymes.

Results are presented to show that N-nitrosodimethylamine demethylase is P-450 mediated and N-nitrosodimethylamine is efficiently metabolized by specific P-450 isozymes inducible by a group of new inducers. The P-450-mediated N-nitrosodimethylamine demethylase also responds differently to inhibitors when activities are compared with those of classical monooxygenase systems.