Biomedical subjects
Publications and source records attributed to J Salazar.
The association of tetralogy of Fallot with absent pulmonary valve and aortic stenosis is extremely rare. In this report the prenatal diagnosis of this anomaly was made in a 28-year-old woman at 31 weeks' gestation.
Work in our lab demonstrated that the early post-operative course of discordant hepatic and renal xenotransplantation is complicated by a pulmonary injury. The aim of this study was to characterize the nature of this injury, as well as to determine whether endothelin-1 (ET-1) and inducible-nitric oxide synthase (iNOS) are present in this form of pulmonary injury. Dog-to-pig orthotopic liver and kidney xenografts were performed. Pulmonary artery pressures were monitored throughout all procedures. The lungs were stained with monoclonal antibodies for ET-1, endothelin converting enzyme-1, and iNOS. The lungs from pig recipients of hepatic or renal xenografts were compared to lungs from untreated pigs. Pulmonary artery pressures were elevated in recipients of liver xenografts when the suprahepatic caval cross clamp was placed and continued to rise to systolic levels following unclamping. The mean pulmonary artery pressures in recipients of renal and hepatic xenografts rose significantly following revascularization. Pathology in lungs from kidney and liver recipients was similar, showing congestion with peribronchial and septal edema, with diffuse adhesion of PMN to alveolar endothelium. ET-1, endothelin converting enzyme-1 (ECE-1), and iNOS staining was widespread and intense in alveolar and pulmonary arterial endothelium. Discordant xenotransplantation of livers and kidneys is associated with a significant early pulmonary injury that is associated with early PMN infiltration and expression of ET-1 and iNOS.
We report a fetus of 35 weeks gestation in which a continuous flow was detected in the lower portion of the right atrium with a peak velocity of 0.8 m/s. After delivery the echo-doppler study showed a dilated coronary sinus in the long axis parasternal view, and a bilateral superior vena cava in the short axis suprasternal notch view. Comments about the cause of this anomalous continuous flow are discussed.
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Sixty-one children with insulin-dependent diabetes mellitus and twenty-three healthy subjects were investigated. The patients with diabetes mellitus aged 4 to 20 years (13.4 +/- 4.0) had had diabetes for 1 to 16 years (6.4 +/- 3.5). There were no cardiovascular risk factor other than diabetes. Patients received no medication other than insulin. The following echocardiographic and Doppler parameters of the left ventricle were analyzed in both groups: systolic and diastolic dimensions, systolic time intervals, fractional shortening, mean velocity of circumferential fiber shortening, percent relaxation of the left ventricular posterior wall at 50% of diastole, peak velocity of early (E) and late atrial (A) mitral flow. E/A ratio, deceleration of the E-wave, and the isovolumetric relaxation time. None of the parameters were significantly different between the groups. There was no relation observed between duration of diabetes and any of the parameters analyzed. It is concluded that there is not echocardiographic data to support the concept of diabetic cardiomyopathy in adolescents with type I (insulin-dependent) diabetes mellitus.
AIM: To study the influence of nitric oxide on renal function. DESIGN: Nitric oxide synthesis was inhibited and the effects on renal parameters were determined. METHODS: Nitric oxide synthesis was progressively blocked by the intravenous administration of increasing doses of NG-nitro-arginine methylester (L-NAME) and then (c)GMP was administered. RESULTS: The blockade of nitric oxide synthesis first induced a marked fall in urinary sodium excretion, and later, a sustained increase in mean arterial pressure. These effects were reversed by 8-bromide cGMP. Nitric oxide-dependent cGMP formation was higher in the inner medulla than in any other part of the renal parenchyma, and the inhibition of nitric oxide synthesis significantly decreased both pressure- and volume expansion-induced natriuresis. CONCLUSIONS: Both the natriuretic and vasodilator tone maintained by nitric oxide are ultimately due to the production of cGMP. Nitric oxide-induced formation of cGMP appears to be the major factor that links changes in renal medullary circulation to those of sodium excretion. Sufficient inhibition of nitric oxide synthesis to decrease sodium excretion without altering blood pressure induces volume-dependent hypertension because blood pressure is elevated by an increased sodium intake.
Two asymptomatic children with an atypical continuous murmur and a clinical diagnosis of coronary artery fistula are reported. Cross-sectional and Doppler echocardiography led to the diagnosis of a right coronary artery-right ventricule fistula in both cases, which was confirmed by coronary angiography. Surgical closure of the fistula was realized without complications.
Clinical evaluation of a 13 1/2-year-old male revealed a 4.4-cm leg length discrepancy and a small penis with a normal endocrine evaluation. Cytogenetic analysis of peripheral blood lymphocytes and skin fibroblasts derived from the back showed 45,X/46,XY mosaicism with similar percentages of 45,X cells, 36% and 30% respectively. However, two separate skin fibroblast cultures derived from the thigh and calf of the short (right) leg showed significant lack of Y-bearing cells with 100% and 80% 45,X, respectively. In contrast, skin biopsies of the thigh and calf of the normal (left) leg both showed 100% 46,XY. Similar evidence for differences in the percentages of Y-bearing cells in the left versus right leg fibroblast cultures was obtained using densitometric scanning of dot blots following DNA hybridization with a Y-specific probe at the DYZ4 locus. Asymmetric limb growth in cases of X/XY lymphocyte mosaicism warrants further cytogenetic investigation to substantiate possible genotype-phenotype correlations which may help uncover the fundamental growth deficiency in Turner syndrome.
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A six-year-old girl with an atypical continuous precordial murmur, was suspected of having a coronary arteriovenous fistula. A markedly dilated right coronary artery was revealed by two-dimensional echocardiography. The pulsed Doppler examination showed a diastolic retrograde flow in the ascending aorta, with a normal flow in the left ventricular outflow tract. With the sample volume in the right ventricle a continuous turbulent flow was observed. Color flow mapping showed a turbulent, systolic-diastolic flow in the right ventricle. The fistula was confirmed by cardiac catheterization.
A case of double outlet left ventricle with pulmonary atresia is reported. The hypoplasia of the left ventricule produced by the almost total absence of its trabecular zone has not been previously reported.
We have used a preliminary formulation of a bioadhesive in an experimental model of epikeratoplasty in rabbits. The adhesive, termed mussel adhesive protein (MAP), is a repeating decapeptide polymer that is the natural adhesive substance produced by the common blue mussel (Mytilus edulis) and is used here in conjunction with an enzymatic cross-linking agent. This study marked the first in vivo use of this material in adhering ophthalmic tissue planes. We used a simplified epikeratoplasty technique highlighted by freehand dissection of donor lenticules and host keratotomies. Approximately 10 microL of a combination of MAP and the cross-linking agent was applied directly to the host cornea and the donor lenticules were secured into the keratotomies using eight interrupted 10-0 nylon sutures. All of the sutures were removed 72 hours postoperatively. Eleven of the 15 animals retained their epikeratoplasty lenticules throughout the entire postoperative period. Four animals had initially intact lenticules that sloughed within the first postoperative week; this sloughing, we believe, was attributable to difficulties in tucking irregularly thickened lenticule edges into the keratotomy. In control animals that had lenticules secured with sutures alone, suture removal at 72 hours consistently produced immediate lenticule sloughing. Clinical examinations and histopathologic studies disclosed no untoward effects of the adhesive on the donor or host corneal tissue. We believe that this preliminary study indicates a potential adjunctive role for MAP in epikeratoplasty.
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We present our clinical experience and the results of surgical management with 25 cavernomas of the CNS, treated in our hospital in the last 10 years. The location of the lesion assessed by clinical and CT scan examinations, proved to be the most significative factor determining the prognosis of cavernomas of the CNS, after surgical removal. The symptoms started in most of the cases in the third decade of life. 19 cases were located in the cerebral hemispheres and produced three well defined clinical syndromes: Irritative syndrome (seizures) present in 70% of the cases. Space-occupying lesion syndrome (20%) and haemorrhagic syndrome (10%). The remaining six cases were located within the basal ganglia, brainstem, pineal region, cerebellum and spinal cord, showing a progressive course. CT scan studies were performed on 24 cases. The characteristic image of a cavernoma is represented by a moderately hyperdense nodule with discreet contrast uptake. Calcification was observed in and around the lesions in 33% of the cases. Perilesional hypodensities suggestive of brain tissue atrophy were noted in 22% of the CT scans. On the other hand, 12% of cerebral hemisphere cavernomas showed atypical CT scan images that suggested an erroneous diagnosis of cystic gliomas. Radical surgical removal was performed in all cases. The postoperative results varied according to the location of the lesions.(ABSTRACT TRUNCATED AT 250 WORDS)
The authors present their clinical and surgical experience with 18 posterior fossa cholesteatomas, including three cases with atypical CT scan appearances that corresponded to calcification, haemorrhage or malignant change into an epidermoid carcinoma, respectively.
The experiences with a series of 9 patients with syringomyelia treated by syringosubarachnoid shunt (SSS) are presented. All of the cases were evaluated by myelography, CT scan or MNR. The cases showed satisfactory results which consisted in stabilization of the symptoms (55%) or clinical improvement (44%). These results should be continuously evaluated, due to the short follow-up period and to the variable natural history of the illness. Treatment by SSS is a technique of low morbidity. It is recommended for patients with syringomyelia without significant descent of the tonsils or in those cases where posterior fossa operations have failed to obtain good results.
Escape from the sodium-retaining effects of aldosterone (ALDO) is thought to occur as a result of natriuretic compensatory mechanisms triggered by extracellular fluid volume expansion. The purpose of the present study was to determine whether increases in plasma levels of atrial natriuretic peptide occur during ALDO escape in conscious dogs (n = 6) maintained on a fixed sodium intake (60 meq/day). Infusion of ALDO at a rate of 15 micrograms X kg-1 X day-1 for 6 days decreased sodium excretion (UNaV) from 59.1 +/- 4.0 to 36.2 +/- 5.7 meq/day on day 1, and then UNaV gradually returned to control levels by day 5 of ALDO infusion. Net cumulative sodium balance progressively increased during ALDO infusion, reaching a peak value of 88.8 +/- 21.3 meq/day on day 5. Mean arterial pressure increased from 85 +/- 3 to 95 +/- 4 mmHg, and plasma renin activity decreased from 1.32 +/- 0.27 to 0.32 +/- 0.07 ng angiotensin (ANG) I X ml-1 X h-1 during ALDO infusion. Plasma levels of atrial natriuretic peptide averaged 67.5 +/- 8.9 pg/ml during control and increased to a peak value of 120 +/- 18 pg/ml by day 4 of ALDO infusion. Three to four days after ALDO infusion was stopped, plasma levels of atrial natriuretic peptide averaged 46 +/- 5 and 50 +/- 6 pg/ml, respectively. In summary, escape from the sodium-retaining effects of ALDO is associated with significant increases in the circulatory levels of atrial natriuretic peptide.
The vein of Galen malformation is a rarely recognized cause of congestive heart failure in the newborn. This report describes a newborn who developed severe cardiac failure in the second week of life. An aneurysm of the vein of Galen was noted on the computerized tomography scan, confirming the clinical diagnosis of cerebral arteriovenous fistula. The vascular abnormality was well shown by cerebral arteriography. At the age of four weeks, surgery was carried out by clipping the afferent arteries. The patient is non a three years old infant with moderate developmental delay and hypotonia.