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Biomedical subjects

S De Castro

Publications and source records attributed to S De Castro.

At least 55 records · Page 3Linked to original sources
PubMed1992

[Modification of the sympatho-vagal interaction in mitral valve prolapse syndrome. Evaluation of heart rate variability by spectrum analysis].

To determine whether clinical manifestations in patients with mitral valve prolapse (MVP) are associated with altered sympatho-vagal tone, 46 patients (mean age 27 +/- 6, range 20-45 years; 18 males and 28 females) were studied by power spectrum analysis of RR variability. Patients were divided in 2 groups, according to echocardiographic criteria: Group A: 11 patients with classical MVP; Group B: 35 patients with non classical MVP. These patients were compared with 30 healthy subjects (Group C) well matched for age, body surface area and heart rate. Our findings indicate that at rest there is a significant difference in the high-frequency component between Group A and Group C. Similarly, during the increase in sympathetic activity induced by 70 degrees head-up tilt all groups showed an increase in the low-frequency component, that was more evident in Group A. The data generated from our laboratory suggest that mitral regurgitation (Group A) is a probable cause of vagal tone increase and that there is an adaptive long-term mechanism towards sympathetic conditions. In addition, probably the normalization, demonstrable by the effect of sympathetic activity in tilt, can mask a dysfunction that may be differently evoked.

Adult↗
PubMed1991

[Noninvasive evaluation of left ventricular function in alcoholics before and after suspension of ethanol abuse].

It is known that chronic alcoholism causes morphological changes of the myocardium before the development of a specific dilated cardiomyopathy. We studied a group of chronic alcoholics, with normal arterial pressure and without clinical evidence of liver cirrhosis, to evaluate left ventricular function, both before and after withdrawal of ethanol. A M-B mode echo recording of the left ventricle and left ventricular inflow Doppler velocimetry with carotid pulse tracing was performed in each patient within 24 hours of the last alcohol consumption and after a period of abstinence at least 3 weeks. We analysed parameters of left ventricular systolic and diastolic functions, in comparison with a group of normal subjects well matched for age, body surface area and heart rate. The results showed that, in the group of alcoholics, a cardiac hypertrophy exists with increased left ventricular mass and normal parameters of left systolic ventricular function, but with altered ratio PEP/LVET. This last result is the consequence of an abnormal left diastolic ventricular function, as demonstrated from the analysis of the Doppler indexes of left ventricular filling (lower ratio E/A). Left ventricular inflow Doppler velocimetry showed different results in alcoholics and control subjects in the early diastolic flow velocity peak (61 +/- 12 vs 84 +/- 8) and in the peak flow velocity in the atrial contraction phase (62 +/- 10 vs 40 +/- 5.6). We have not observed any change of the echocardiographic parameters after the short period of alcohol withdrawal. We advance the hypothesis that there is an altered diastolic function depending, not only on the hypertrophy of the myocardium, but also on the myocardial interstitial involvement caused by ethanol.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Intracavitary cardiac metastasis of osteosarcoma: echocardiographic aspects].

Osteosarcoma is a malignancy whose various sites of metastasis greatly modify its ultimate prognosis. In this study we present a case of a 15 years old girl affected by osteosarcoma of the left femur with cardiac metastasis in the right ventricular cavity. The echocardiogram made it possible the in vivo diagnosis. It is recommended that an echocardiographic study is performed routinely in patients affected by osteosarcoma.

Adolescent↗
PubMed1987

Early experience with Telehealth during sport activities.

In order to verify the usefulness of a system designed to provide participants of sport competitions with a cardiological emergency service, the authors utilized a cardiotelephone apparatus during a "24-hour Marathon race" in which 1008 subjects took part. In 18 cases, an ECG was transmitted owing to various symptoms after exertion. One case of pseudoischaemia and one of complete A-V block were registered. The authors emphasize the importance of a telephone ECG transmission system as a special aid able to cut down the intervention time without moving the patients.

Adolescent↗
PubMed1985

Androgen receptor content in cytosol from non-tumoral human kidney and its relation to steroid hormone environment.

The content of cytoplasmic androgen receptors (Bmax) was analyzed in non-tumoral renal tissue of 12 men and 15 postmenopausal women using a synthetic androgen (methyltrienolone) as ligand and a method of dextran-coated charcoal. The Bmax in both sexes was compared, establishing correlations between it and circulating levels of testosterone, dehydroepiandrosterone sulfate, androstenedione, and estradiol to find out the possible influence of the hormonal environment on androgen receptors in the human kidney. No differences in Bmax were observed between males (46.3 +/- 24 fmol/g of tissue) and females (45.4 +/- 26 fmol/g), in spite of the significantly greater (p less than 0.01) levels of circulating testosterone in the former group. No significant linear correlations existed between any of the steroids analyzed and the Bmax. These results demonstrate the existence of androgenic receptors in non-tumoral human kidney and indicate that its content is not regulated by circulating levels of testosterone. The concentrations of the principal extratesticular androgens and estradiol do not seem to have a quantitative influence on these androphilic proteins either.

Adult↗
PubMed1980

Liver iron storage in Spanish aging population.

Liver samples were collected at autopsy from 70 aged (33 males and 37 females) and 22 young (13 males and nine females) individuals. The liver iron stores of young males (327.00 +/- 50.57 micrograms/g) (mean +/- SEM) are higher than young females (143.48 +/- 32.94 micrograms/g; P < 0.02). There is no difference between the values found for old males (301.72 +/- 31.70 microgram/g) and old females (258.61 +/- 24.14 micrograms/g) or between young and old males. The incidence of low iron stores (less than 50 microgram/g) in males and females of the aged group is similar to that found in the group of young males. It is concluded that in the aged Spanish population studied iron stores are not diminished.

Adult↗
PubMed1979

Metabolism of red blood cells in chronic renal failure. I. Glycolytic enzyme levels.

This paper starts a series on red blood cell (RBC) metabolism in patients with chronic renal failure (CRF). The glycolytic enzyme levels and in vitro half-lives of these patients' RBCs were determined. A number of enzymes (hexokinase, glucose-6-phosphate isomerase, fructose-6-phosphate kinase, aldolase, glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase) showed higher activities than in normal control RBCs. Other enzyme activities were normal. These results were discussed and several possible mechanisms considered. We favour the point of view of a shortened life span of the RBCs in CRF, making the most unstable enzymes of the glycolytic sequence appear increase as compared with normal controls.

Adolescent↗
PubMed1979

Pharmacokinetics of Amikacin (BB-K8) in patients with normal or impaired renal function.

The pharmacokinetics of Amikacin (BB-K8) were determined after a single i.v. injection of 7.8 mg of the antibiotic/kg of body weight. It was administered to 10 patients with normal renal function and 19 patients with varying degrees of renal impairment. The elimination of Amikacin from plasma was seen to follow the course of an open two-compartment model system. From patients with normal renal function, values for the following pharmacokinetic parameters were obtained: alpha = 4.219 hr-1; beta = 0.292 hr-1; K12 = 2.218 hr-1; K21 = 0.859 hr-1; K13 = 1.432 hr-1; Vc = 3.125 1; Vp = 8.068 1 and Vdss = 11.193 1. As the relationship K12/K21 is greater than 1, it may be seen that there is a tendency for the antibiotic to accumulate in the peripheric compartment. Impaired renal function significantly diminishes the values recorded for alpha, beta, K12, K21, K13. Distribution volumes are significantly increased in patients with renal impairment. A linear relationship between the K13 of Amikacin and creatinine clearance is demonstrated. Adjustment of Amikacin dosage, according to the individual degree of renal impairment, may be obtained by spacing out the injections.

Adolescent↗