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Biomedical subjects

J Duarte

Publications and source records attributed to J Duarte.

At least 19 recordsLinked to original sources
PubMed1992

Effects of aminophylline on contractions and 45Ca uptake in isolated rat vascular smooth muscle.

1. Aminophylline inhibited the contractions induced in rat isolated aorta by high K and noradrenaline (NA) as well as the transient contraction induced by NA in Ca-free media and suppressed the spontaneous myogenic activity in portal vein segments. 2. Aminophylline had no significant effects on 45Ca influx in resting aorta but inhibited 45Ca influx stimulated by high K or NA. 3. It is concluded that aminophylline inhibited Ca entry through voltage- and receptor-operated channels and NA-induced Ca release from intracellular stores. A part of the vascular inhibitory effects of aminophylline may be mediated by a cAMP-dependent mechanism.

Aminophylline↗
PubMed1991

First clinical implantation of the BCM 3.5 ventricular assist device (VAD).

We report on the first human implantation of the BCM 3.5 ventricular assist device in a 46-year-old man suffering from terminal stage cardiomyopathy. The circulatory support was used as a bridge to heart transplantation. The patient was in cardiogenic shock and was on assisted circulation for 18 days after which he underwent cardiac transplantation. While receiving support from the ventricular assist device, the patient's condition improved remarkably and 50 days after transplantation he was discharged from hospital. We give a detailed description of the surgical technique, with special emphasis on the procedures for air extraction. We describe the evolution of the hemodynamic status before and after implantation. Final inspection of the device and cannulae after removal showed no thrombi and only small fibrin deposits in the membrane-wall junction.

Cardiomyopathy, Dilated↗
PubMed1991

Vasodilator effect of olive leaf.

We studied the importance of the smooth vascular muscle endothelium in the vasodilator action of the decoction of olive (Olea europaea) leaf. The decoction caused relaxation of isolated rat aorta preparations both in the presence (IC50 1.12 +/- 0.33 mg/ml) and in the absence (IC50 1.67 +/- 0.16 mg/ml) of endothelium. The results indicate that the relaxant activity of the lyophilized decoction is independent of the integrity of the vascular endothelium. We also showed that oleuropeoside is a component responsible for vasodilator activity but, from the results, it seems likely that at least one other principle is to be found in the olive leaf which is either a vasodilator itself or else potentiates the relaxant effect of oleuropeoside.

Animals↗
PubMed1991

Effects of flecainide on isolated vascular smooth muscles of rat.

1. The inhibitory effects of flecainide were studied on contractile responses in rat isolated aortae and caudal artery and on spontaneous mechanical activity in portal vein segments. 2. In rat isolated aorta flecainide, 10(-6) M-5 x 10(-4) M, inhibited in a dose-dependent manner the contractile responses induced by high K (80 mM) and noradrenaline (NA, 10(-5) M). These inhibitory actions were observed when flecainide was added before or after the induced contractions and were similar in aortae with or without endothelium. 3. Contractile responses induced by addition of Ca to Ca-free high-K solution were also dose-dependently inhibited by flecainide (IC50 = 2.5 +/- 0.3 x 10(-5) M). Moreover, flecainide inhibited the contractile responses elicited by NA in rings incubated in Ca-free solution. 4. Flecainide also inhibited the spontaneous mechanical activity in portal vein segments (IC50 = 6.5 +/- 0.9 x 10(-5) M). 5. Flecainide, 10(-4) M, inhibited 45Ca uptake stimulated by high K or NA without altering 45Ca uptake in resting aortae. 6. These results indicated that in rat isolated aortae, caudal arteries and portal veins, flecainide inhibited Ca entry through voltage-operated channels and NA-induced Ca uptake as well as Ca release from intracellular stores, thus decreasing the availability of intracellular free Ca required for vascular smooth muscle contraction.

Animals↗
PubMed1990

Vascular reactivity in chronic Goldblatt two kidney-one clip hypertensive rats.

We studied the possible contribution of increased vascular reactivity in the chronic phase of Goldblatt two kidney-one clip hypertension. Vascular reactivity was evaluated in aortic strips from hypertensive rats (16 weeks after inducing hypertension) and age-matched control rats. The findings were: a) increased sensitivity to vasopressin in the aortic tissue of hypertensive rats, b) a similar response to angiotensin II, noradrenaline and KCl in hypertensive and control rats, and c) reduced maximal response to angiotensin II compared with other vasoconstrictors in both groups of rats. These results suggest a possible role for vasopressin in the chronic phase of this model of hypertension.

Angiotensin II↗
PubMed1989

Blood biochemistry values of sheep (Ovis aries ligeriensis).

1. Analysis of biochemical parameters were carried out on material pooled from 30 female sheep (Ovis aries ligeriensis). 2. The values determined were for the common metabolites and enzymes utilized for specific studies in general metabolism (urea, glucose, cholesterol, lipids, bilirubin, uric acid, creatinine, alkaline phosphatase, GOT, GPT, LDH, LAP, CGT, CK and amylase). 3. Results of these studies were compared with values from normal human adults. 4. The differences obtained in human and sheep ranges can be explained by the different physiology of the two species. 5. This study gives values for the sheep as an experimental animal in biomedical research.

Animals↗
PubMed1989

[Internal urethrotomy under direct vision. Review of 183 operations].

The authors report on their experience with the Sachse urethrotomy procedure performed in 125 patients from 1981-1987, with a minimum follow-up of 12 months and a maximum of 6 years. The etiology was iatrogenic in 46%, trauma in 25%, and inflammatory in 33%. Stricture was frequently localized in the bulbous urethra (63%). Local anesthesia was the most widely used particularly during the latter stage of this period. The authors prefer to use Sylastic-type catheters left indwelling for a short period of time. Their recurrence rate was 15%. Although most of the patients (67%) required one procedure, urethrotomy had to be repeated up to three times (3%) in several patients. Good results were achieved in 57%, fair in 32%, and poor in 11%.

Follow-Up Studies↗
PubMed1987

Epidemic outbreak of Serratia marcescens infection in a cardiac surgery unit.

Between 2 February and 16 April 1985, an outbreak of Serratia marcescens infection involving 10 male patients occurred in a cardiac surgery unit. All the patients had surgical wound infection, five also had osteomyelitis (four sternal, one costal), and another had peritonitis secondary to peritoneal dialysis. Three patients had concomitant bacteremia. All Serratia strains isolated produced a cherry-red pigment, and all had the same biochemical and antibiotic susceptibility pattern. An intensive search for the origin of the outbreak was initially unsuccessful, and it proved impossible to isolate S. marcescens from cultures of numerous samples taken from hospital personnel and from the environment. The fact that all patients were male and had been shaved for surgery by the same team of barbers led us to investigate the shaving procedures. We finally isolated a strain of pigmented S. marcescens, corresponding to that involved in the outbreak, from samples taken from the hands and equipment of the barbers. After suitable action had been taken, the epidemic terminated.

Barbering↗
PubMed1986

Fracture of the Carpentier-Edwards ring in tricuspid position: a report of three cases.

Three cases of fracture of a Carpentier-Edwards ring in tricuspid position are presented. In all three cases the shape of the ring was shown to be abnormal by roentgenogram examination; there was an abrupt bend in the middle portion of each ring. At the time of operation, fracture of the ring skeleton at this midpoint was found in all three instances. Roentgenogram examination seems to be a reliable method of diagnosing this uncommon entity, and tricuspid valve replacement is required for its correction.

Adult↗
PubMed1985

Left atrial ball thrombus.

The existence of a freely-floating thrombus in the left auricle is a rare finding in mitral pathology. Diagnosis by two-dimensional echocardiography has been described by various authors (1, 2, 3). In our case echocardiographic diagnosis of auricular thrombus was not possible at the beginning, given the bad ultrasonic window. Only when the thrombus floated freely in the left auricle it was detected in the region of the mitral valve, in spite of the bad ultrasound window.

Aortic Valve Insufficiency↗
PubMedDate not supplied

[Radial nerve injury caused by external compression during the dissection of the internal mammary artery in coronary surgery].

Injury of the radial nerve produced by external compression during dissection of the internal mammary artery during surgery of ischemic heart disease, is an infrequent event. The use of sternal retractors with only one rod may be the cause of these lesions. We report two cases of radial nerve paralysis produced as a consequence of external compression induced by a sternal retractor during dissection of the internal mammary artery. In the first case the patient showed loss of power of the external muscles of the left forearm and a clear flexion of the left hand. The second patient presented loss of power of the left hand and impossibility to extend the carpus and fingers. In both cases the lesion was reversible.

Equipment Design↗
PubMedDate not supplied

Acute renal failure associated with cardiac surgery.

We present the incidence, management and outcome of acute renal failure (ARF) in children who underwent cardiac surgery. Fourteen (9%) from a total of 156 children developed ARF in our hospital in a 3-year period. Patients were aged 2 days to 15 years. Prerenal failure was present in 6 and renal type in the remaining 8 children. Peritoneal dialysis treatment was utilized in 58% of patients. Neurologic and respiratory complications were present. Mortality rate was 58% and related to underlying pathology and to complications in other organs. The management of these patients must be by competent personnel preferably trained in pediatrics.

Acute Kidney Injury↗