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Biomedical subjects

V López

Publications and source records attributed to V López.

At least 37 records · Page 2Linked to original sources
PubMed1997

Balance between oxidative damage and proliferative potential in an experimental rat model of CCl4-induced cirrhosis: protective role of adenosine administration.

Oxidative stress and its consequent lipid peroxidation (LP) exert harmful effects, which have been currently involved in the generation of carbon tetrachloride-induced cirrhosis. However, the recent report that "physiological" LP can be associated with liver regeneration (LR) makes it necessary to discriminate between oxidative stress-induced and LR-associated LP. In rats rendered cirrhotic by continuous CCl4 administration for 4 weeks, moderate cell necrosis and fine fatty infiltration were found. The histological abnormalities were accompanied by increased LP, mainly accounted for by the microsomal and cytosolic fractions and evidence of oxidative stress (decreased hepatic glutathione content and changes in xanthine oxidase and pentose phosphate pathway activities). After 8 weeks, a micronodular cirrhosis developed, but oxidative stress was greatly attenuated, only persisting in the enhanced LP confined to microsomes. Simultaneous administration of adenosine, a reliable hepatoprotector that readily prevents the onset of liver fibrosis, was able to block the oxidative stress induced by the long-term CCl4 treatment but elicited a selective subcellular distribution of increased LP, similar to that found during LR. The adenosine-induced changes in liver LP (mainly in the nuclear fraction) correlated with an increased activity of thymidine kinase. Therefore, data suggest that adenosine-mediated preservation of energy availability and mitochondrial function could participate in preventing the onset of oxidative stress in cirrhotic rats. The latter could induce a successful liver recovery, curtailing the sequence of events leading to fibrogenesis.

Adenosine↗
PubMed1997

Employee and public responses to simulated violations of no-smoking regulations in Spain.

OBJECTIVES: This study evaluated compliance with regulations prohibiting smoking in public places by using a new method of smoking simulation. METHODS: Sites in Sabadell, Spain, were visited by observers who lit a cigarette, simulating the act of smoking, and noted the placement and content of signs indicating smoking restrictions. RESULTS: A warning was given in only 17% of sites. A significant association was observed between the presence of signs banning smoking and the elicitation of a warning from people present. CONCLUSIONS: Simulating the violation of smoking restrictions may be used as an efficient method of assessing enforcement of the prohibition of public smoking.

Humans↗
PubMed1997

[Follow-up study of the evolution of the quantitative EEG in intraventricular infusion of nerve growth factor in an aged baboon].

The animal model of aged monkeys is a good homologue of Alzheimer's disease in humans, in which it has been shown that there is disproportionate slowing of the EEG when compared with healthy subjects paired for age. This is found both on the conventional EEG and quantitatively. In the latter, relative energy has been the measurement most commonly used for diagnosis and follow-up with various treatments. The follow-up parameters evaluated in this study were: absolute and relative energy of the quantitative EEG (EEGq) obtained in an aged (39 year old) baboon (Papio hamadryas) before and after infusion of intraventricular nerve growth factor (NGF). These findings were compared with those of a young animal (6 year old) of the same species, treated in the same way. Since the animals were first anaesthetized with ketamine and diacepam so as to be able to carry out the study, we used a cerebral function analyzer which allowed us to ascertain that the changes found on analysis of the EEGq were not due to the depth of anaesthesia. The analyzer evaluated the tendencies of amplitude and frequency of the EEG, which is a method widely used for the indirect evaluation of the level of anaesthesia.

Aging↗
PubMed1996

Hepatic and erythrocytic glutathione peroxidase activity in liver diseases.

Hepatic and erythrocytic glutathione peroxidase activity, together with malondialdehyde levels, were determined as indicators of peroxidation in 83 patients from whom liver biopsies had been taken for diagnostic purposes. On histological study, the patients were classified into groups as minimal changes (including normal liver), steatosis, alcoholic hepatitis, hepatic cirrhosis, light to moderately active chronic hepatitis, and severe chronic active hepatitis. The glutathione peroxidase activity in erythrocytes showed no significant changes in any liver disease group. In the hepatic study, an increased activity was observed in steatosis with respect to the minimal changes group, this increased activity induced by the toxic agent in the initial stages of the alcoholic hepatic disease declining as the hepatic damage progressed. There was a negative correlation between the levels of hepatic malondialdehyde and hepatic glutathione peroxidase in subjects with minimal changes. This suggested the existence of an oxidative equilibrium in this group. This equilibrium is broken in the liver disease groups as was manifest in a positive correlation between malondialdehyde and glutathione peroxidase activity.

Erythrocytes↗
PubMed1996

[A new classification of lower infarcts with important prognostic significance].

BACKGROUND: The initial therapy of acute myocardial infarction is often determined by the electrocardiogram. OBJECTIVE: To evaluate a classification of inferior myocardial infarctions according to the first electrocardiogram. DESIGN AND SETTING: Prospective study in a coronary care unit. PATIENTS: 116 patients admitted due to a first acute myocardial infarction of the inferior wall. METHODS: "Type 1" electrocardiogram was defined as ST segment elevation without distortion of the QRS. Patients were considered "type 2" when, besides ST segment elevation, they presented a distortion of the terminal portion of the QRS complex in two inferior leads. MAIN RESULTS: Twenty-nine patients (25%) were considered "type 2". These patients were older and had worse Killip class than "type 1". The mortality rate was 1.2% in "type 1", and 24.1% in "type 2" (p = 0.0002). After multivariate analysis, which included Killip class, age, smoking, type of electrocardiogram and fibrinolysis, the type of electrocardiogram remained significantly predictive of death (p = 0.014). CONCLUSIONS: We conclude that "type 2" electrocardiogram is an independent predictor of adverse outcome in inferior infarctions. Further investigation is needed concerning its implications in the clinical management of these patients, although reperfusion therapy is warranted.

Adult↗
PubMed1995

Androstenedione metabolism in the indifferent stage of bovine gonad development.

Suspensions of cells obtained from genital ridges and gonads of bovine embryos of 1.0-3.4 cm in crown-rump (C-R) length were used for studies of the metabolism of radiolabeled exogenous steroid precursor. Tritiated androstenedione was employed as precursor and the final products of their metabolism were evaluated after separation by thin-layer chromatography. Genetic sex was determined by the karyotype of hepatocytes from the same embryos. The extent of conversion of tritiated androstenedione was higher in cells from male embryos than cells from female embryos. Furthermore, androstenedione was metabolized mainly to testosterone in male embryos. By contrast, cells obtained from female embryos transformed androstenedione to estrone and 17 beta-estradiol. The onset of this activity was observed at 1.8 cm in C-R length in males and at 2.2 cm in C-R length in females. In all cases, after the onset, the metabolic activity increased in relation to the age of the embryos. These data show that in the bovine embryo gonad, the activity of aromatase and 17 beta-hydroxysteroid dehydrogenase are present when the morphological differentiation of the gonadal sex has not yet been established.

Androstenedione↗
PubMed1995

[Age is the independent prognostic factor in acute myocardial infarct. The clinical course of infarct in the elderly patient].

We analyze the influence of age in the evolution of patients with acute myocardial infarction admitted to our Coronary Care Unit throughout two years (1990 and 1991). All 542 patients admitted during this period were classified in three groups: 299 less than 65 year old (group A), 170 between 65 and 74 year old (group B), and 73 with 75 year old or more (group C). Aged patients had a worse clinical condition, with significantly more previous heart failure, diabetes or hypertension, and the Killip's class was worse in group C than in group B, and worse in this than in group A (p = 0.00000). The mortality rate was 6.7% in group A, 12.9% in group B, and 31.5% group C (p = 0.00000). After a multivariate analysis, only three factors were significantly associated to prognosis: previous stroke, Killip's class, and group of age. Fibrinolytic therapy and coronary arteriography were less frequent with old people (p = 0.00000 and p = 0.00000 respectively). We conclude that age is an independent factor of prognosis during myocardial infarction. Old people have a worse clinical condition and the treatment is less aggressive than in young people.

Age Factors↗
PubMed1995

[The prognosis for elderly patients admitted to a coronary unit for myocardial infarct: the changes over a decade].

INTRODUCTION AND AIM: New therapies have been added that improve prognosis of patients with myocardial infarction. Our purpose was to know if elderly patients reach benefit from these therapeutic changes. METHODS: We have analyzed the clinical data of 227 patients older than 70 who were admitted in our coronary care unit: 78 admitted in 1980-81 and 14 admitted in 1990-91. RESULTS: Although differences were not significant, in 1990-91 there were more women (36% versus 28%), less smoking (24% versus 33%), more patients with previous infarction (19% versus 12%), more hypertension (53% versus 43%), less anterior infarcts (38% versus 45%) more non Q infarcts (11% versus 1%), and less bundle branch block (21% versus 31%). In 1990-91, pacemakers were used less often (13% versus 27%, p = 0.03), thrombolytic therapy was given to 16 patients (10.7%), and the mortality rate was a little inferior (22% versus 30%, not significant). Female sex, not being a smoker, Killip class and bundle branch block were significantly related to mortality. After a multivariate analysis in which these factors we included, the date of admission resulted an independent predictor of mortality, with an odds ratio of 1990-91 to 1980-81 of 0.43 (p = 0.039). CONCLUSIONS: The management of patients older than 70 with myocardial infarction has improved, with a significantly lesser risk of dead after multivariate analysis, despite that thrombolysis has been scarcely applied.

Aged↗
PubMed1994

Outcome of patients with diabetes and unstable angina. A subgroup analysis in the Spanish Multicentre Trial of trifusal in unstable angina. Grupo de Estudio del Trifusal en la Angina Inestable.

We analyzed the clinical characteristics of the 58 diabetic and 218 nondiabetic patients enrolled in the Spanish multicentre trial of trifusal in unstable angina. After 6 months of follow-up, 25 suffered from myocardial infarction or death, 10 of which were diabetics (17.2%) and 15 nondiabetics (6.9%) (P = 0.0146). This difference remained significant after multivariate analysis. We conclude that diabetes is an independent predictor of adverse outcome in patients with medically treated unstable angina.

Aged↗
PubMed1994

Transient myocardial injury after elective electrical cardioversion.

A patient with recent myocardial infarction underwent elective direct current countershock because of atrial fibrillation. After several shocks, the ST segments were strikingly raised throughout the precordial leads, which disappeared with the administration of a perfusion of nitroglycerin. This case is evidence that electrical cardioversion can cause myocardial damage.

Aged↗
PubMed1993

Steroid metabolism in the cortex and the medulla of the early fetal bovine ovary.

Suspensions of cells obtained from the cortex and the medulla of the ovary of early bovine fetuses of 4-10 cm in crown-rump (C-R) length were used for studies of the metabolism of radiolabeled exogenous steroid precursors. Tritiated dehydroepiandrosterone, androstenedione, and testosterone were employed as precursors and their metabolic products were evaluated after separation by thin-layer chromatography. The extent of conversion of tritiated dehydroepiandrosterone to androstenedione was higher in cells from medulla than in those from the cortex. Androstenedione was metabolized mainly to estrone, and the percent of transformation was similar in the cortex and the medulla, but the rate of formation of 17 beta-estradiol was higher in the medulla than in the cortex. Furthermore, cells obtained from the cortex and the medulla aromatized testosterone to 17 beta-estradiol at a similar rate. In all cases, the percent of transformation was higher in ovaries from fetuses of 4.0 cm in C-R length than those from fetuses of 9.0-10.0 cm in C-R length. These data suggest that, in the bovine fetal ovary, the activity of 3 beta-hydroxysteroid dehydrogenase/isomerase and 17 beta-hydroxysteroid dehydrogenase predominates in the medulla, whereas aromatase activity is similar in the cortex and the medulla of the early fetal bovine ovary.

Androstenedione↗
PubMed1992

Coronary arterial disease in patients with severe isolated aortic stenosis.

We reviewed the prevalence of coronary arterial disease in a consecutive series of 117 patients with severe isolated aortic stenosis. Coronary arterial disease was present in 18 of 48 patients with typical angina, in 10 of 38 patients with atypical angina, and in 4 of 31 patients without angina. We suggest that absence of angina is not enough to omit coronary arteriography in the evaluation of severe aortic stenosis.

Aged↗
PubMed1992

Prevention of myocardial infarction by nitroglycerin plus intravenous beta-blockers.

Seven patients with ongoing angina with ST-segment elevation, refractory to oral nifedipine and intravenous nitroglycerin, were treated by adding intravenous beta-blockers. Chest pain resolved in all of them in a few minutes, and myocardial infarction did not develop in 5 patients. We recommend this approach for patients to whom thrombolytics are contraindicated or have been very recently administered, although further investigation is needed to extend its application more widely. It does not preclude the use of other therapies, if considered necessary.

Adrenergic beta-Antagonists↗
PubMed1991

Thrombolytic therapy soon after left heart catheterization--is it safe?

Puncture of a femoral artery for left heart catheterization is considered a relative contraindication for thrombolytic therapy for some days. We treated 9 patients with systemic thrombolysis who had undergone left heart catheterization in the previous hours. Four patients developed a large hematoma, but only 1 required transfusion. We suggest that thrombolytic therapy can be administered soon after left heart catheterization by the femoral approach, provided that continuous care can be taken over the puncture site.

Adult↗
PubMed1991

Inequalities in health in intensive care patients.

In order to study the possible association between socioeconomic status (SES) and critical care mortality, we examined a cohort of 847 patients over 14 years of age, as they were consecutively admitted to three general intensive care units (ICUs). The patients with low SES (social classes IV and V according to the British Registrar General's classification) were older (62.0 v 58.5 years old, p less than 0.0001) and showed a higher ICU mortality (odds ratio (OR) = 1.61, p = 0.0204) and severity of illness on admission (mean Simplified Acute Physiology Score [SAPS] 9.9 vs 8.7, p = 0.0002) than patients with high SES (social classes I-III). The initial severity of illness differential was detected both in patients admitted from the emergency area and in patients admitted from the general hospitalization ward, suggesting the existence of some kind of preselection procedure related to the SES of the patient. The stepwise logistic regression analysis identified as independent predictive variables of ICU mortality therapeutic effort (measured with the Therapeutic Intervention Scoring System [TISS]), SAPS score, age and hospital, but not SES. The TISS/SAPS ratio according to origin of patients (emergency/general wards) was comparable in the high and low SES. We conclude that there is an inverse relationship between SES and ICU mortality. The mortality excess in the low SES patients is largely accounted for by the covariates of the low SES (especially their high age and severity of illness on admission). There is no evidence of a different relative therapeutic effort according to the SES.

Adolescent↗