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Biomedical subjects

A C de Castro

Publications and source records attributed to A C de Castro.

7 recordsLinked to original sources
PubMed2001

Expression of the major heat shock proteins DnaK and GroEL in Streptococcus pyogenes: a comparison to Enterococcus faecalis and Staphylococcus aureus.

One of the outstanding problems in the field of heat shock response has been to elucidate the mechanism underlying the induction of heat shock proteins (HSPs). In this work, we initiate an analysis of the expression of heat shock groEL and dnaK genes and their promoters in S. pyogenes. The synthesis of total cellular proteins was studied upon transfer of a log-phase culture from 37 degrees C to 42 degrees C by performing 5-min pulse-labeling experiments with (35)S-Met. The heat shock responses in the pathogenic Gram-positive cocci, Enterococcus faecalis and Staphylococcus aureus, were also analyzed.

Bacterial Proteins↗
PubMed2000

Preliminary assessment of heavy metal levels in Mytella falcata (Bivalvia, Mytilidae) from Bacanga River estuary, São Luís, state of Maranhão, northeastern Brazil.

The concentrations of Cu, Zn, Pb, and Cd were determined in the mussel Mytella falcata from the Bacanga River estuary, in order to evaluate the potential role of domestic effluents released "in natura" on the quality of the estuarine environment with consequences to shellfish resources. Cu concentrations ranged from 5.2 mg.g-1 to 13.1 mg.g-1, while Zn concentrations ranged from 49.1 mg.g-1 to 76.3 mg.g-1. Pb and Cd showed concentrations lower than 2 mg.g-1. The results showed low concentrations of Cu, Pb and Cd in the filter-feeding Mytella falcata in the study area in comparison with the maximum values stablished to foods by the Brazilian Government (Decree Law No 55,871). Finally, Zn presented slightly higher values than the maximum ones stablished by the Brazilian government.

Animals↗
PubMed1995

Surgical correction of aortic disease using intraluminal, crimped bovine pericardial graft.

We propose the use of a crimped bovine pericardial graft joined to a rigid and grooved ring for the treatment of aortic dissections and aneurysms. This device was developed to support common tubular vascular prostheses of any material, length, diameter, or form, transforming them into intraluminal ones during the surgical procedure. During March 1989 to May 1994, 74 patients underwent an operation on the aorta in which this intraluminal ring, prepared from a tubular prosthesis of bovine pericardium, was used. Twenty-seven patients had an acute type A aortic dissection, 6 had an acute type B aortic dissection, 10 had annuloaortic ectasia, 6 had a descending aortic aneurysm, 3 had a thoracoabdominal aneurysm, and 22 had an abdominal aneurysm. The global mortality rate of 10.8% in the immediate postoperative period cannot be related to the surgical technique or the type of prosthesis used. We conclude from our findings that this modification of the sutureless intraluminal graft, which allows it to be used to replace diseased segments of the aorta, affords the quickest and simplest means of repair and is attended by the least likelihood of anastomotic complications.

Adult↗
PubMed1990

Correlation between growth in antibiotic-medium and hemolytic activity of group C and G streptococci.

The effect of a subminimal inhibitory concentration of penicillin on the production of bound and free hemolysins by streptococci was examined using sheep red blood cells. A marked decrease of a group C cell-free and bound activities was observed with penicillin at a concentration of 1/3 of the MIC whereas an increase was observed with those of a group G strain. Potassium ferricyanide and anti-streptolysin O (group A streptococcus) were strongly inhibitory for the free activities of both strains. The cell-bound activities were stimulated by addition of RNA during bacterial growth in control cultures and also in drug-containing media.

Animals↗