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Biomedical subjects

A Villar

Publications and source records attributed to A Villar.

At least 91 records · Page 5Linked to original sources
PubMed1991

[Contrast echocardiography in the diagnosis of severe hypoxemia associated with liver cirrhosis].

Severe hypoxemia is an uncommon feature of hepatic cirrhosis. Its major cause are intrapulmonary arteriovenous shunts, both due to direct arteriovenous communications and abnormally dilated pulmonary capillaries. In the present study, a case of cirrhosis associated with severe hypoxemia is reported. Contrast echocardiography showed pulmonary arteriovenous shunts, and low values of mixed venous blood (15% or less were obtained with the method of 100% oxygen breathing). These data suggest that the basic mechanism of hypoxemia, in this case, were capillary dilatations rather than true pulmonary arteriovenous anastomoses. The pathophysiological mechanisms of hypoxemia in cirrhosis are discussed, with emphasis on the present relevance of echocardiography for a full evaluation of these patients, particularly when liver transplantation is contemplated.

Aged↗
PubMed1991

Effects of khellin on contractile responses and 45Ca2+ movements in rat isolated aorta.

The effects of khellin on contractile responses and 45Ca2+ flux have been studied in rat isolated aortae. Khellin (10(-5)-3.2 x 10(-4) M) produced a concentration-dependent inhibition of noradrenaline (10(-6) M) and high K+ (80 mM)-induced contractions. At 3.2 x 10(-4) M, khellin increased cAMP levels and reduced 45Ca2+ influx in resting tissues and in tissues stimulated by noradrenaline (10(-5) M) and high K+ without affecting basal 45Ca2+ efflux or noradrenaline induced 45Ca2+ efflux. It is concluded that in rat isolated aorta, khellin caused a non-specific inhibition of Ca2+ influx but may also exhibit intracellular actions, thus decreasing the availability of Ca2+ required for activation. One or more of these mechanisms may be related to an increase in intracellular cAMP levels.

Animals↗
PubMed1991

[Correlation of plasma lipids and microproteinuria in diabetes mellitus].

Microproteinuria is an early sign of clinical diabetic nephropathy, and it also has the power to predict cardiovascular mortality in both types of diabetes. In order to investigate this last aspect, we have analyzed serum lipids in diabetes type I and II (128 male patients) with or without microproteinuria [determined using MICRAL/TEST (Boerhinguer M)]. The results revealed the following: hypertriglycerinemia and a low HDL-Cholesterol level in insulin dependent diabetes mellitus together with hypercholesterolemia in non insulin dependent diabetes mellitus. It seems that both microproteinuria as well as hyperlipidemiain diabetes mellitus reflect a generalizes vascular lesion.

Adult↗
PubMed1991

[Primary Sjogren's syndrome in men: evolution to acute lymphoblastic leukemia].

A clinical case of a 55-year-old man with syndrome of primary Sjögren, seronegative, normoglobulinemic and normocomplementary with 7 years of evolution, which developed acute lymphoblastic leukemia, having suffered recurrent lympho-adenopathy and paresthetic meralgia as previous clinical signs, is presented. Clinical, serological and immunologic characteristics of this syndrome are reviewed, highlighting its rare appearance among men. While appearance of malignant lymphoproliferation disorders is well known, evolution to acute or chronic myeloid leukemia is very rare and so far, an acute lymphoblastic leukemia as the one presented in this study has never been described.

HLA Antigens↗
PubMed1990

[The indications for benzodiazepines in the treatment of insomnia].

We interviewed 219 patients with a questionnaire to evaluate the prevalence of insomnia, and to assess whether benzodiazepine therapy was correctly indicated. Insomnia was present in 86 patients (39%), being initial in more than one half. Thirty-two of the patients with insomnia were receiving benzodiazepines (37%), 24 of whom (75%) had been treated for more than one year. The drug was incorrectly indicated in 18 (56%), in most cases because it was inappropriate for the type of the patient's insomnia. In six of these patients (33%), incorrect indication was related with self-medication. The benzodiazepine was incorrectly indicated in all the patients with diurnal oversedation. We emphasize the frequency of incorrect indications of these drugs, and we insist on the need that general practitioners have of a better knowledge of the pharmacokinetics of each drug, which is the basis for a correct indication.

Adult↗
PubMed1990

Effect of beta-sitosterol-3-beta-D-glucoside on insulin secretion in vivo in diabetic rats and in vitro in isolated rat islets of Langerhans.

Beta-Sitosterol-3-beta-D-glucoside (1) has been reported to be the active antidiabetic agent of Centaurea seridis L. var. maritima. The present study examines the effect of oral administration of this compound on plasma insulin and glucose levels in streptozotocin-induced diabetic rats and its influence on insulin release from isolated rat islets. The results indicate that 1 did not change insulin and glucose levels in rats with severe diabetes. 1 stimulated insulin release from isolated rat islets in the presence of a non-stimulatory glucose concentration but did not increase the insulin releasing capacity of glucose (16 mmol/l). These data suggest that 1 exerts its action on intact pancreatic beta-cells by stimulating insulin secretion.

Animals↗
PubMed1989

[Hemorrhagic syndrome associated with a factor VIII:C inhibitor in a patient with lymphoma].

Acquired hemophilia (idiopathic or secondary) is an uncommon clinical condition. A 70-year-old male had a severe hemorrhagic disorder, and an IgG inhibitor of the factor VIII:C was detected in plasma. During the acute phase he was treated with packed red blood cells, frozen fresh plasma and polyvalent immunoglobulins. The hemorrhagic features subsided but the circulating anticoagulant persisted. The administration of an activated prothrombin complex permitted to make the diagnosis of the underlying disease, a highly malignant T type lymphoma. During the treatment with corticosteroids and polychemotherapy the inhibitor activity disappeared.

Aged↗
PubMed1989

Lyme myocarditis diagnosed by indium-111-antimyosin antibody scintigraphy.

We report a new case of Lyme disease with cardiac manifestations, which has been possible to follow during the long period of 12 years. We have detected the usual ECG abnormalities, and concentric hypertrophic myocardiopathy, by echocardiography. The acute myocarditis was demonstrated by 111In-antimyosin scintigraphy, which showed global myocardial uptake of the tracer, constituting the first report, to our knowledge, of Lyme myocarditis diagnosed by this method.

Adult↗
PubMed1989

A review of natural products and plants as potential antidiabetic drugs.

The present paper reviews the active, natural principles and crude extracts of plants which have been experimentally studied for hypoglycemic activity in the last ten years. Phytoconstituents with known structures have been classified in appropriate chemical groups and the active crude extracts have been listed alphabetically according to genus. Data are reported on their pharmacological activity, mechanism of action, toxicity and other properties.

Animals↗
PubMed1989

Inhibitory effects of Santolina chamaecyparissus extracts against spasmogen agonists.

Several extracts of Santolina chamaecyparissus ssp. squarrosa antagonized in a concentration-dependent way the contractions of rat duodenum, guinea-pig ileum, rat vas deferens and rat uterus as induced by acetylcholine, histamine, noradrenaline, oxytocin and serotonin. Polar extracts were less active than apolar extracts, and it was necessary to assay the former at higher concentrations. Only the lyophilized aqueous extract produced a slight hypotensive effect when given intravenously at 150 mg/kg to urethananesthetized rats.

Animals↗
PubMed1989

Oral idarubicin in measurable gastric cancer.

Seventeen patients with advanced gastric adenocarcinoma, previously untreated with chemotherapy, have been included in a Phase II study with idarubicin (IDA), 15 mg/m2/day, orally, for three consecutive days every 3 weeks. All cases had measurable disease. Sixteen of 17 patients are evaluable for response. Complete or partial responses were not observed. Two patients had partial response less than 50%, one patient no change, and the remaining 13 patients disease progression. The median leukocytes and platelets nadir was 3600 and 186,000/mm3, respectively. Gastrointestinal toxicity was mild. The median total cumulative dose of IDA was 90 mg/m2 (range 45-180 mg/m2). Clinical cardiac toxicity was not observed. IDA, at the dose and by the route used, is not active in gastric cancer.

Adenocarcinoma↗
PubMed1989

Relaxant actions of khellin on vascular smooth muscle.

To clarify the mechanism of the vasodilatory action of khellin on calcium, we have investigated its relaxant action on base line and on K+ and noradrenaline-induced contractile tensions in rat aorta smooth muscle and on spontaneous contractile activity of rat portal vein. Khellin relaxed both of these preparations with a similar potency, which suggests a non-specific inhibition of calcium flux, without any difference related to the specific calcium channels. We have also studied the capacity of khellin to interfere with the loading and release mechanisms of caffeine and noradrenaline-sensitive calcium stores in Ca-free medium. Khellin's Ca2+ loading reduction may be related with its capacity to inhibit calcium influx. Khellin applied during Ca2+ release also caused relaxation. We propose that this drug may enhance calcium extrusion or sequestration rather than the calcium release mechanism. These actions on calcium influx and intracellular mobilization can contribute to its vasorelaxant action.

Animals↗