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Biomedical subjects

A Ramirez

Publications and source records attributed to A Ramirez.

At least 109 records · Page 6Linked to original sources
PubMed1976

Effect of intracisternal phentolamine on cerebral blood flow after subarachnoid injection of blood.

The hydrogen clearance method was used to measure total and focal cerebral blood flow (CBF) in the monkey before and for 5 hours after a simulated subarachnoid hemorrhage (SAH). Some monkeys also received 0.2 to 1.0 mg/kg phentolamine intracisternally 3 hours after SAH. Results show that SAH did not change cerebrovascular resistance, but as cerebral perfusion pressure decreased, CBF fell transiently. Phentolamine injected intracisternally 3 hours after SAH produced a significant fall in arterial blood pressure; cerebrovascular resistance did not change but CBF decreased significantly. These data indicate that intracisternal phentolamine cannot be considered potentially useful to treat ischemic encephalopathy after SAH.

Animals↗
PubMed1976

Double-blind evaluation of intradiscal chymopapain for herniated lumbar discs. Early results.

The authors report 66 patients with signs, symptoms, and a myelographic abnormality of herniated lumbar disc, who were not responsive to conservative treatment. The discs were injected at random with either chymopapain or a placebo. Neither patient nor surgeon knew which agent was used until after the results had been tabulated. Unless early laminectomy was necessary for intractable pain, all patients were followed for 2 months or more. There was no statistically significant difference in incidence or quality of improvement between the two groups: chymopapain was successful in 58% while placebo was successful in 49% (p = 0.15). Early results from this study indicate that most, if not all, of the putative effectiveness of chemonucleolysis probably derives from a placebo effect.

Adult↗
PubMed1970

Hemodynamic effects of pneumonia. II. Expansion of plasma volume.

Previous work has demonstrated that approximately one-third of patients with pneumonia have a hypodynamic circulatory response. This response is characterized by an abnormally wide arteriovenous oxygen difference, a low cardiac output, increased peripheral resistance, and an increased hematocrit. This state was found to abate in convalescence. In an attempt to elucidate the pathogenesis of this hypodynamic state, nine additional patients were studied hemodynamically during the acute phase of pneumonia before and during acute expansion of blood volume by low molecular weight dextran (seven patients) or normal saline (two patients). Five patients were restudied before and during acute blood volume expansion in convalescence. Three patients with pneumonia had a normal arteriovenous oxygen difference (< 5.5 vol%), and six patients were hypodynamic in that their arteriovenous oxygen differences were greater than 5.5 vol%. With expansion of blood volume in the acute phase of pneumonia, all patients showed an increase in cardiac output, a decrease in arteriovenous oxygen difference, and a decrease in peripheral vascular resistance; however, the percentage change in the hypodynamic patients was not as great as occurred in the patients with normal hemodynamics nor as great as occurred when restudied in convalescence. Likewise, all patients had a normal or near normal hemodynamic profile in convalescence. In addition, ventricular function in the acute phase of pneumonia was depressed. The findings suggest that the hypodynamic state associated with acute pneumonia is due to depressed myocardial contractility to which relative hypovolemia may contribute.

Acute Disease↗