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Biomedical subjects

A A Fisher

Publications and source records attributed to A A Fisher.

At least 19 recordsLinked to original sources

Molecular cloning and characterization of the constitutive bovine aortic endothelial cell nitric oxide synthase.

The constitutive endothelial cell nitric oxide synthase (NOS) importantly regulates vascular homeostasis. To gain understanding of this enzyme, a pEF BOS cDNA library of 5 x 10(5) clones was prepared from bovine aortic endothelial cells (BAEC) and screened with a 2.8-kb cDNA BamHI fragment of rat brain NOS. Clone pBOS13 was found to express NO synthase activity when transfected into COS-7 cells. Sequence analysis revealed sequences compatible with binding domains for calcium/calmodulin, flavin mononucleotide, flavin adenine nucleotide and NADPH. The deduced amino acid sequence revealed a protein with a relative mol mass of 133,286, which is 58% homologous to the rat cerebellar NOS and 51% homologous to the mouse macrophage NOS. The amino-terminal portion of the protein exhibits several characteristics peculiar to the endothelial cell NOS. These include a proline-rich region and several potential sites for proline-directed phosphorylation as well as a potential substrate site for acyl transferase. Northern hybridization to mRNA from cultured BAEC revealed an abundant 4.8-kb message, which was not increased by coincubation with tumor necrosis factor alpha, but was markedly increased by exposure to shear stress for 24 h. The unique features of the endothelial cell NO synthase, particularly in the amino terminal portion of the molecule, may provide for novel regulatory influences of enzyme activity and localization.

Amino Acid Oxidoreductases

[The rheology of the gastric mucus and the secretory activity of the main gastric glands in patients with duodenal peptic ulcer].

A study of 150 patients with ulcer and 38 healthy persons revealed that duodenal ulcer is characterized not only by an increase of the acid- and pepsin-secretory gastric function but also by a reduction of the resilient-viscous properties of the native parietal mucus. Complex determination of acid and pepsin secretion, rheological properties of the gastric mucus is of high diagnostic and prognostic importance.

Adolescent