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Biomedical subjects

R Macruz

Publications and source records attributed to R Macruz.

At least 37 records · Page 2Linked to original sources
PubMed1985

Laser surgery in enclosed spaces: a review.

We describe the results of experiments carried out in the arteries of dogs, rabbits, guinea pigs, and humans, normal or atheromatous, calcified, or not, with the application of the argon and CO2 laser, in vitro or in vivo, directly or indirectly. Similarly, we present the results of laser effects when radiation is delivered through a special catheter with the purpose of producing aortic insufficiency, opening pulmonary valvular stenosis, desobstructing carotid and coronary obstruction induced in dogs as well as atheromatous obstructions in human amputated legs. Arterial wall perforation was present in 50% of all cases. We suggest four options in order to diminish this adverse result: (1) the use of coherent optical bundles which will allow the proper guiding of the laser beam, (2) the construction of a special catheter for proper handling of the laser-carrying fiber, (3) a combination of optical and computer programs which will aid to identify calcified regions, and (4) the use of dyes which will be strongly and selectively absorbed by the atheromas and which will thus allow their destruction at low laser powers.

Animals↗
PubMed1985

Rabies virus in different segments of brain and spinal cord of naturally and experimentally infected dogs.

In order to determine the presence of rabies virus in different segments of Central nervous system (CNS) of rabid animals, 31 naturally infected dogs and 6 experimentally injected ones by masseter inoculation were studied by means of Fluorescent Antibody (FA) technique and mouse intracerebral inoculation (MI) test. In the naturally infected group, the positivity by FA technique was 100.0% for the segments of Ammon's horn, cerebellum, bulb and for cervical, lumbar and sacral cord and 96.7%; for thoracic cord. Mouse inoculation test of corresponding materials was 100.0% positive for Ammon's horn, cerebellum, bulb and lumbar cord; 96.7% for cervical cord; and 93.5% for sacral cord. All examined segments of experimentally infected animals were 100.0% positive for both FA and MI tests. No clear-cut relationship could be found between the site of virus inoculation and the presence of the virus in the spinal cord. The results presented in this paper corroborate previous suggestions for the use of the spinal cord as one of the alternative laboratory diagnostic specimens for the canine rabies diagnosis.

Animals↗
PubMed1984

Hemodynamic determinants of coronary constriction in human myocardial bridges.

To study the physiopathology of myocardial bridges, we assessed the degree of systolic coronary artery constriction (%SC) in different hemodynamic situations in six patients submitted for coronary angiograms. There was an increase of %SC (p less than 0.05) with sodium nitroprusside (NP), no modification during fast atrial stimulation (AS), and a decrease (p less than 0.05) during noradrenaline infusion (Nor). Hemodynamic studies indicate an inverse relation (p less than 0.05) between %SC and systolic and diastolic aortic pressure and left ventricular dP/dt. There was no correlation between changes in %SC and changes in Vmax or heart rate. Thus we conclude that changes in systemic arterial pressure and coronary perfusion pressure may significantly affect the degree of severity of myocardial bridges, possibly through an influence upon intraluminal coronary pressure and an intramyocardial tension relationship.

Adult↗
PubMed1983

Vascular anastomosis by argon laser beam.

Twenty-four mongrel dogs, weighing 13 to 24 kg, were used to study the effectiveness of anastomosis by Argon Laser beam. After anesthesia, intubation and controlled ventilation, they were submitted to three types of vascular anastomoses: saphenous vein intercarotid artery bypass; left mammary artery/left anterior descending coronary artery bypass; and veno-venous anastomosis. In all groups, 0.8 to 1.5 watts of Argon Laser power were applied for a total time of 90 to 300 seconds. The lower power was for veno-venous anastomoses and the greater was applied for arterial anastomoses. The mean values of resistance of the laser anastomosis to pressure-induced repture were 730 mm Hg in the immediate postoperative study, but increased to 2,500 mm Hg 30 days after surgery. No signs of occlusion were demonstrated at the anastomotic sites by the angiographic and anatomopathological studies performed.

Journal Article↗