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Biomedical subjects

D Ortega

Publications and source records attributed to D Ortega.

At least 55 records · Page 3Linked to original sources
PubMed1988

[Function of the right ventricle in interauricular communication in adults].

This study was designed prospectively to analyze the influence of age and operation on right ventricular function in atrial septal defect; 17 patients were studied by means of radionuclide studies performed immediately before and approximately 6 months (5,8 +/- 2,3) after surgery. The pulmonary/systemic flow ratio (Qp/Qs) was determined by first pass technique, and right ventricular ejection fraction and peak filling rate were determined by equilibrium ventriculography. In addition, all patients had preoperative catheterization. According to age, patients were divided in group I (less than 35 years) and group II (greater than or equal to 35 years). Preoperatively, patients in group I, in comparison to group II, had better ejection fraction (48 +/- 8 vs 36 +/- 7; p less than 0.01), and better peak filling rate (3.7 +/- 0.9 vs 2.6 +/- 0.7; p less than 0.01), while Qp/Qs were not significantly different (2.5 +/- 0.8 vs 3.0 +/- 1.6) and pulmonary vascular resistances were less elevated (69 +/- 32 vs157 +/- 95 dynes/sec/cm-5; p less than 0.01). After surgery, right ventricular function did not significatively change in relation to preoperative data in both groups (ejection fraction: 44 +/- 13 and 34 +/- 5, respectively; peak filling rate: 3.3 +/- 1.4 and 2.1 +/- 0.6). We conclude that in atrial septal defect indexes of systolic and diastolic right ventricular function deteriorate with age, these changes being associated with a slight increase in pulmonary vascular resistance without changes of Qp/Qs; right ventricular dysfunction does not tend to improve postoperatively.

Adolescent↗
PubMed1986

Risk of myocardium adjacent to infarcted myocardium: electrocardiographic, metabolic and scintigraphic evidence within the first week of acute myocardial infarction.

Atrial pacing was carried out within 5 days of an uncomplicated acute myocardial infarction (AMI) in 28 patients to detect the existence of a menaced area. A positive pacing response (at least 1.0 mm of ST-segment shift) was observed in 23 patients (82%, group I), whereas pacing results were negative in 5 (18%, group II). Pacing-induced electrocardiographic changes involved the leads affected by AMI in patients with transmural necrosis. A well-defined thallium-201 redistribution, mostly localized near or within the AMI site, was present in 10 patients from group I (43%), in 1 from group II (20%), and in 1 of 12 comparable patients (8%) in whom pacing was not performed. During pacing, abnormal lactate metabolism was observed in 11 of 17 patients from group I (65%) and in 0 of 5 from group II (0%). A 90% or greater coronary stenosis of at least 1 artery was found in 19 of 23 patients from group I (83%) and in 1 of 5 from group II (20%); 2- to 3-vessel disease (more than 70% diameter stenosis) was present in 14 patients from group I (61%) and 1 from group II (20%). During a 15-month follow-up (range 9 to 25), effort angina developed in 9 patients from group I (39%) and in none from group II. No deaths or reinfarctions occurred in either group. Thus, very early after a first AMI, most patients have a jeopardized periinfarction area that is usually associated with a critical coronary stenosis and that heralds effort angina in a significant proportion of them.

Adult↗
PubMed1986

Amelioration of adriamycin-induced cardiotoxicity in rabbits by prenylamine and vitamins A and E.

The cardioprotective potentials of prenylamine (a calcium antagonist) and of a combination of vitamins A and E (a singlet oxygen quencher and a free radical scavenger, respectively) were evaluated in rabbits given chronically large doses of Adriamycin (ADM) (10.8 mg/kg body weight for 9 to 11 weeks). Among ADM-treated rabbits, 8 of 10 showed post-treatment ECG changes; in rabbits treated with ADM and prenylamine, changes were found in a smaller number (5 of 10); and in animals treated with ADM and vitamins A and E, the incidence was only one in six (p less than 0.05). Heart homogenates from ADM-treated rabbits showed an increased hydroperoxide-initiated chemiluminescence (expressed as cpm/mg protein X 10(-3)) of 77 +/- 4 compared to control animals (52 +/- 1) (p less than 0.01). Prenylamine administration did not alter hydroperoxide-initiated chemiluminescence in ADM-treated rabbits, whereas treatment with a combination of vitamins A and E showed a significant decrease in hydroperoxide-initiated chemiluminescence in control (40 +/- 2) and ADM-treated rabbits (42 +/- 1). Microscopically, myocardial fibers had mild to severe hydropic vacuolization of sarcoplasm, which led to progressive myocytolysis. A total of 103 +/- 13 damaged fibers were detected over 700 counted fibers. Myocardial damage was lowered to 47 +/- 16 by administration of prenylamine and to 28 +/- 8 by administration of vitamins A and E. It is suggested that ADM leads to myocardial lipid peroxidation (ameliorated by vitamins A and E) with membrane damage and to an increase in calcium permeability, the latter being counteracted by prenylamine.

Animals↗
PubMed1981

[Control of gastric acidity with cimetidine given as premedication before general anesthesia: efficacy and tolerance].

Cimetidine 400 mg was administered intramuscularly 60 minutes before the beginning of general anaesthesia. The double blind experiment was conducted on 84 patients divided in two groups: cimetidine and control. There was no difference in gastric fluid volume between the two groups during general anaesthesia, but acid secretion decreased significantly in the cimetidine group. Values of pH lower than 2.5 were observed in 33.3 per cent at induction and 34 per cent at recovery in the control group against 14.6 per cent and 0 per cent in the cimetidine group. Clinical tolerance to cimetidine was studied in 100 patients during operation. Cimetidine did not alter pharmacological action of usual anaesthetics. There were no significant changes in cardiovascular and electrocardiographic data.

Anesthesia, General↗
PubMed1980

The diagnosis of Cushing's syndrome using 131I-19-iodocholesterol uptake and adrenal imaging.

Uptake measurements and visualization of the adrenal glands were performed using 131I-19-iodocholesterol in ten healthy subjects and fourteen patient suffering from Cushing's syndrome (nine hyperplasias and five adenomas). The normal range in healthy subjects (average uptake value +/- 2 SD) is 0.12-0.27% for both adrenals. In patients with Cushing's syndrome the uptake values ranged from 0.321 to 1.497%. Normal bilateral images were obtained in all the healthy subjects as well as in eight of the patients with hyperplasia, whilst the remaining patient with hyperplasia showed distinctly enlarged glands. In contrast, an image of the diseased side only was obtained in patients with adrenal adenomas. We conclude that radiocholesterol studies in Cushing's syndrome allow confirmation of the diagnosis, definition of the pathophysiologic type of disease and lateralization of adrenal adenomas.

19-Iodocholesterol↗
PubMed1980

[Cimetidine in pre-anaesthetic premedication. Intra-operative clinical tolerance (author's transl)].

Intra-operative clinical tolerance of cimetidine was studied in 100 patients undergoing abdominal surgery. Cimetidine (400 mg) was administered one hour before operation intramuscularly. Cimetidine did not alter pharmacological action of usual anesthetics. Recovery was quieter. There was no significant changes in cardiovascular and electrocardiographic datas. These results are in accordance with previous prospectives works. However, heart rate seems to decrease three hours after cimetidine injection. Such bradycardias as well as blood pressure drop have been recently published by various authors in retrospective studies, and may be explained by an action of cimitidine on cardiac H2 receptors.

Cimetidine↗
PubMedDate not supplied

[Factors associated with postoperative mortality following gastric adenocarcinoma surgery at the Edgardo Rebagliati Martins Hospital].

OBJECTIVES: This study is a retrospective, descriptive and observational evaluation aimed at defining the factors associated with postoperative mortality due to gastric adenocarcinoma and evaluating postoperative morbidity at the Edgardo Rebagliati Martins Hospital. METHODS: The study included 282 patients, which had undergone surgery between January 1, 1996 and December 31, 1999 and the evaluation involved filiation, background, tumor location, Bormann and Early Cancer classifications, histological classification, number of resected lymphatic nodes, extragastric compromise, type of surgery and reconstruction, TNM classification, clinical stage and medical and surgical complications. RESULTS: Patients were divided in two groups: Survivors (n=251) and deceased (n=31) evidencing 31.56% morbidity and 10.99% mortality. The factors associated with mortality were: age, hypertension (AHT), cardiopathy, tumor location in the stomach, extragastric compromise of the liver, T3 and T4 tumors, N1, distant metastases, clinical stage IV, pneumonia and other surgical complications. CONCLUSIONS: These results lead us to conclude that proper preoperative staging of the disease is necessary and so is special care with patients suffering of hypertension, diabetes and cardiopathy.Finally, we consider it pertinent to bear in mind the postoperative complications, for proper management of them.

Adenocarcinoma↗