Biomedical subjects

J O Freitas Júnior

Publications and source records attributed to J O Freitas Júnior.

4 recordsLinked to original sources

PubMed1999

Cutting balloon angioplasty for intrastent restenosis treatment.

We describe here two patients with angiographic diagnosis of intrastent restenosis and regional myocardial ischemia. One stent restenosis was located in a native coronary artery and the other in a vein graft. Both were treated with cutting balloon angioplasty (CBA), inflated at low pressures. Angiographic success was obtained and both patients were discharged in the day after the procedure. Cutting balloon angioplasty using low inflation pressures achieved important luminal gains, in these two cases of intrastent restenosis. Further studies are necessary before the effectiveness of this procedure can be precisely defined.

Adult↗

PubMed1996

Basic aminopeptidase from rabbit kidney: purification and partial characterization.

The aminopeptidase activity of a homogenate of rabbit kidney treated with Triton X-100 was measured using L-aminoacyl-2-naphthylamides (AA-NA). After gradient elution ion-exchange chromatography, four peaks of aminopeptidase activity were eluted. The enzyme eluted at 450 microS containing 33.5% of the activity towards Arg-NA was applied to a Superdex 75 column and presented only one protein band on 10% SDS-polyacrylamide gel electrophoresis. This enzyme has an apparent molecular mass of 78 kDa, is five-fold activated by 0.15 M NaCl and the highest Vmax/KM ratio was obtained with Arg-NA. Enzyme activity was inhibited 100% by 0.13 mM sodium p-hydroxymercuribenzoate, 20% by 0.75 mM EDTA and 100% by 0.66 mM o-phenanthroline. Puromycin and bestatin behaved like competitive inhibitors with a Ki of 0.60 mM and 5.0 microM and 5.0 microM, respectively.

2-Naphthylamine↗

PubMed1992

Inhibition of aminopeptidase activity by aromatic and other cyclic compounds.

The effect of 2-naphthylamine, p-nitroaniline, o-phenanthroline, sodium deoxycholate and hydrocortisone succinate on the activity of human urine aminopeptidase, rat kidney methionyl and arginyl aminopeptidase, soybean and Enterolobium contortisiliquum seed aminopeptidase was studied using aminoacyl-2-naphthylamide and L-Leu-p-nitroanilide as substrates. Ki values ranged from 10 microM to 2.7 mM. On the basis of Ki and Km values, and catalytic efficiency for each enzyme, it is clear that the aminopeptidases from human urine and from soybean seed should be assayed with both substrates, whereas L-Leu-p-nitroaniline is a more appropriate substrate for the rat kidney aminopeptidases. Sodium deoxycholate is a better inhibitor than hydrocortisone succinate. Non-competitive inhibition was observed in all cases except for E. contortisiliquum seed aminopeptidase.

Aminopeptidases↗

PubMed1991

Methionyl aminopeptidase from rat liver: distribution of the membrane-bound subcellular enzyme.

The selective distribution of methionyl aminopeptidase (MAP) among rat liver mitochondria (heavy and light) and microsomes is reported. Several properties of MAP from the three subcellular fractions showed that the enzyme is a typical aminopeptidase able to remove N-terminal methionine from oligopeptides and methionyl-2-naphthylamide but not from Met-Ala-Ser. MAP is a membrane-bound enzyme sensitive to SH-group oxidants and inhibitable by L-methionine but not by usual arylaminopeptidase inhibitors. It is suggested that, MAP may play an important role during protein synthesis in rat liver.

Amino Acid Sequence↗