PubMed Health⌕ Search

Biomedical subjects

J Sandoval

Publications and source records attributed to J Sandoval.

At least 55 records · Page 3Linked to original sources
PubMed1986

Effect of hydralazine on intrapulmonary shunt.

We compared the acute effects of bilateral arteriovenous may be related to levels of PvO2. The hydralazine-associated (p less than .05) decrease in resistance. Mixed venous oxygen fistulas to those of hydralazine infusion on hemodynamics and pulmonary gas exchange in dogs with pulmonary edema induced by administration of oleic acid. Oleic acid significantly (p less than .01) increased intrapulmonary shunt (Qsp/Qt) and pulmonary and systemic vascular resistance, and reduced cardiac output. Once the lesion stabilized, both opening the fistula and infusing hydralazine produced a similar and significant (p less than .01) increase in cardiac output, and a significant (p less than .05) decrease in resistance. Mixed venous oxygen tension (PvO2) closely followed the changes in cardiac output; however, PaO2 did not change. Qsp/Qt significantly (p less than .01) increased with the fistulas open and with hydralazine infusion. Closure of the fistulas or bleeding the animal at the end of the experiment reversed the changes in cardiac output and Qsp/Qt. The comparable increases in cardiac output and Qsp/Qt produced by opening the fistulas or infusing hydralazine may be related to levels of PvO2. The hydralazine-associated PvO2 increase indicates that this drug increased oxygen transport to the tissues even as Qsp/Qt became larger.

Animals↗
PubMed1986

Comparative scanning electron-microscopic study of the lingual papillae in two species of domestic mammals (Equus caballus and Bos taurus). 1. Gustatory Papillae.

The morphological characteristics of bovine and equine gustatory lingual papillae are compared by scanning electron microscopy. The fungiform papillae in the cow have a shape that corresponds to their name, while in the horse, they almost do not emerge from the surface of the tongue. These papillae show taste pores in both species. The vallate papillae, four times larger in the horse than in the cow, show a complex organization of papillae and secondary grooves in the horse. In the cow, they occur single and are surrounded by a thick annular pad of lingual mucosa. Taste pores have been observed in the vallate papillae of both species, whereas in the foliate papillae, they are present only in the horse. A characteristic distribution of stratified scales and channeled tracts is observed on the surface of all gustatory papillae in both species. The possible functional importance of each type of gustatory papilla is discussed on the basis of their morphostructural features.

Animals↗
PubMed1985

Increased cardiac output increases shunt: role of pulmonary edema and perfusion.

In low-pressure pulmonary edema increased cardiac output (QT) increases shunt (Qs/QT); we tested whether the mechanism is an increase in extravascular lung water in turn mediated by the accompanying increase in microvascular pressure. In six pentobarbital sodium-anesthetized dogs ventilated with O2 we administered oleic acid into the right atrium. From base line to 2 h post-oleic acid we measured concurrent significant increases in Qs/QT (6-29%, O2 technique) and extravascular thermal volume (ETV, 2.6-7.1 ml/g dry intravascular blood-free lung wt, thermal-green dye indicator technique) that were stable by 90 min. Then, bilateral femoral arteriovenous fistulas were opened and closed in 30-min periods to cause reversible increases in QT and associated Qs/QT. When fistulas were open the time-averaged QT increased from 5.1 to 6.9 min (P less than 0.05), the simultaneous Qs/QT rose from 30.7 to 38.4% (P less than 0.05), but ETV did not increase. We conclude that increasing lung edema does not account for our rise in Qs/QT when QT increased.

Animals↗
PubMed1985

Hemodynamic effect of hydralazine in interstitial lung disease patients with cor pulmonale. Immediate and short-term evaluation at rest and during exercise.

Hydralazine was administered short-term to 13 patients who had stable interstitial lung disease (ILD), pulmonary arterial hypertension (PAH); mean pulmonary arterial pressure ( [PAP]=26 +/- 9 mm Hg), and cor pulmonale (CP). All patients were studied at rest and during exercise. After intravenous hydralazine at rest, there were statistically significant increases in cardiac index (CI) (p less than 0.001), arterial oxygen saturation (SaO2) (p less than 0.01), and mixed venous saturation (S-vO2) (p less than 0.01). Pulmonary vascular resistance (Rp) (p less than 0.005) and systemic resistance (Rs) decreased (p less than 0.001), and PAP did not change. During exercise, PAP did not change; however, CI (p less than 0.01), PaO2 (p less than 0.001), and S-vO2 (p less than 0.01) increased further. The increase in Rp was significantly reduced (p less than 0.01). After continuation of oral hydralazine therapy in 12 patients for 7 days, PAP at rest was not statistically different from control; Rp and Rs remained decreased (p less than 0.001). The same results were found for CI, PaO2, S-vO2, and Rs during exercise. Although PAP did not change from control values, the drug significantly reduced the increase in Rp (p less than 0.005). Vasodilator therapy with hydralazine could be useful in patients with stable ILD who have inflammation with minimal to moderate fibrosis and PAH and might be used as an adjunct to conventional therapy for ILD and CP.

Administration, Oral↗
PubMed1983

Independent influence of blood flow rate and mixed venous PO2 on shunt fraction.

We have tested the independent and combined effects of changes in mixed venous PO2 (PvO2) and blood flow (QT) on shunt fraction (Qs/QT) in isolated blood-perfused canine left lower lobes with edema. The lobes were ventilated with pure O2. Inflow (Pi) and outflow (Po) pressures always exceeded lobar alveolar pressure. PvO2 was varied by means of a clinical bubble oxygenator with appropriate mixtures of O2 and N2. QT was varied by changes in Pi and Po with care not to produce changes in lobar weight. Changes in QT did not influence Qs/QT. Increasing PvO2 from 40 +/- 6 to 88.4 +/- 40 Torr at constant QT significantly increased Qs/QT from 5.5 +/- 2.0 to 15.6 +/- 7.0%. Combined increases in QT and PvO2 from 66.4 +/- 2.7 to 135.6 +/- 21.5 ml/min and from 38.8 +/- 1.3 to 61.8 +/- 2.2 Torr, respectively, also produced a significant increase in Qs/QT from 7.33 +/- 2.27 to 15.43 +/- 4.45%. However, this combined change was explained exclusively by changes in PvO2. We therefore concluded that, under the conditions of our experiment, changes in PvO2 influence Qs/QT, and this may account for apparent dependence of Qs/QT on cardiac output in pulmonary edema.

Animals↗
PubMed1983

Peripheral airways obstruction in idiopathic pulmonary artery hypertension (primary).

The mechanical properties of the lung were studied in ten nonsmokers with idiopathic pulmonary artery hypertension (IPAH) (mean pulmonary artery pressure 65.7 +/- 30 mm Hg). In the routine lung test, residual volume was found to be abnormal (greater than 120 percent of the predicted) in seven patients, and measured airway resistance was normal in eight out of the ten patients. A decreased FEF 75-85 percent, abnormal values for the helium-air flow ratios and increased closing capacities were documented in eight of ten patients in whom lung elastic recoil was normal (six of ten) or increased (four of ten). These features suggest peripheral airways obstruction (PAO) which was also supported by histopathologic findings in three cases (one biopsy and two necropsies). The observed changes in lung compliance could be related to the behavior of the coupling of the air-space and vascular compartments. The etiology of PAO in IPAH patients is not known, but our results indicate that both the peripheral airways and the pulmonary circulation are affected. The knowledge of PAO in IPAH patients could help to better understand the observed V/Q inequality in this entity.

Adolescent↗
PubMed1983

Natural history of chagasic cardiopathy in Chile. Follow-up of 71 cases after 4 years.

As part of study of Chagasic cardiopathy in Chile we report a follow-up study of 100 cardiopathic patients from two endemic areas who had been diagnosed 4 years earlier during an epidemiological and clinical survey. The follow-up consisted of a clinical, serological and electrocardiographic examination, and a continuous ECG recording for 60 min to detect possible arrhythmias. From the original 100 cases, three had died: one of a gastric cancer and the other two due to probable chagasic cardiopathy. Twenty-six had migrated to other areas and were lost to our study. From the remaining 71 patients, 48 were asymptomatic and 23 had complaints including palpitations, dyspnoea and Stokes-Adams crisis. In most cases, seropositivity by indirect haemagglutination did not change, but in six cases the titres decreased, becoming negative in three of them. Xeno-diagnosis was positive in 19.3% of seropositive patients. The ECG had returned to normal in 18 cases (17%) but showed a higher degree of blockades in others, three of which reached complete A-V block. The 60 min ECG was very important as it showed alterations in 93% of the cases, revealing arrhythmias that the ECG alone did not show. This work demonstrates that chagasic cardiopathy in Chile is a slow, progressive disease, that attacks the heart as a whole, but with special damage to the conducting tissues.

Adult↗
PubMed1982

The role of hydralazine therapy for pulmonary arterial hypertension of unknown cause.

Hydralazine was administered acutely to 12 patients who had pulmonary arterial hypertension of unknown cause. All of the patients were studied at rest and nine during exercise. On the basis of hydralazine response at rest, the patients were divided in two groups. In six patients (group A), pulmonary arteriolar resistance (Rp) decreased from 8.4 +/- 1.4 to 4.8 +/- 1.4 U/m2 (p less than 0.001), cardiac index (CI) increased from 3.47 +/- 0.3 to 5.86 +/- 0.5 1/min/m2 (p less than 0.005) and systemic resistance (Rs) decreased from 25 +/- 4 to 14 +/- 2 U/m2 (p less than 0.01). The Rp/Rs ratio did not change significantly after hydralazine (0.32 +/- 0.03 vs 0.33 +/- 0.07, NS). In the other six patients (group B), Rs decreased from 25 +/- 2 to 17.0 +/- 1 U/m2 (p less than 0.01), but the other variables did not change significantly. Our results suggest that the pulmonary vasodilatory effect of hydralazine caused a marked reduction in right ventricular afterload in group A. In group B, a marked systemic vasodilatory effect occurred and right ventricular afterload was not reduced. On the basis of the previous hemodynamic response, only group A patients were treated with oral hydralazine (50 mg every 6 hours). Hemodynamic measurements were repeated 48 hours after hydralazine, both at rest and during exercise, as well as 8 months later in five of the six patients in whom the beneficial hemodynamic effects persisted. These data suggest that hydralazine can reduce Rp in selected patients (pulmonary arterial pressure less than 60 mm Hg, Rp less than 15 U/m2 and Rp/Rs ratio less than 0.7) with pulmonary hypertension of unknown cause.

Administration, Oral↗
PubMed1982

Behavior of the pulmonary circulation in chronic obstructive pulmonary disease. Pathogenesis of pulmonary arterial hypertension at an attitude of 2,240 meters.

The hemodynamics of the pulmonary circulation were examined in 28 patients with severe and stable chronic obstructive pulmonary disease (COPD) who were born and raised at high altitude (2,240 meters) (COPD-A). All patients had mean pulmonary pressures (PAP) greater than 16 mmHg. We observed: (1) a low correlation between pulmonary arterial diastolic pressure (PAd) and arterial oxygen saturation (r = 0.38, p less than 0.05); (2) similar PAP in patients with COPD living at sea level (COPD-S) and patients with COPD-A (COPD-S, 32 +/- 7 mmHg; COPD-A, 27.5 +/- 11 mmHg; p = NS), despite more unsaturation in patients with COPD-A (COPD-S, 84.6 +/- 6%; COPD-A, 77.5 +/- 9%; p less than 0.05) and similar arterial pH; (3) lower levels of PAP in COPD-A (COPD-S, 51.7 +/- 10 mmHg; COPD-A, 33.6 +/- 12 mmHg; p less than 0.001) for the same degree of unsaturation (COPD-S, 71 +/- 6%; COPD-A, 71 +/- 8%; p = NS) and a lower arterial pH in COPD-S (COPD-S, 7.34 +/- 0.03; COPD-A, 7.39 +/- 0.04; p less than 0.01). We conclude that pulmonary hypertension caused by chronic alveolar hypoxia is present in COPD-A, but it seems to be decreased when compared with that observed in COPD-S.

Adult↗
PubMed1982

The role of isoproterenol in the preoperative evaluation of high-pressure, high-resistance ventricular septal defect.

The experience we describe derives from the short-term administration of isoproterenol in 15 patients with ventricular septal defect (VSD) and severe pulmonary artery hypertension (PAH). For the whole study group, mean pulmonary artery pressure (PAP) was 68.5 +/- 2.6 mm Hg, pulmonary vascular resistance (Rp) was 11.6 +/- 0.9 U/m2, pulmonary vascular resistance/systemic vascular resistance ratio (Rp/Rs) was 0.9 +/- 0.03, and the pulmonary vascular gradient (PAd-PWP) was 45 +/- 3.5 mm Hg. Infusions of isoproterenol decreased PAP, Rp, Rp/Rs ratio, and PAd-PWP an average of 10.2 mm Hg, 2.88 U/m2, 0.13 and 6.6 mm Hg, respectively, for the whole group (P less than 0.001). On the basis of isoproterenol response, the patients could be divided into two groups: A (n = 4) and B (n = 11). In group A, the PAP decreased from 61.7 +/- 1 to 45 +/- 4 mm Hg, the Rp from 8.9 +/- 0.3 to 4.62 +/- 0.5 U/m2, the Rp/Rs from 0.84 +/- 0.02 to 0.55 +/- .05, and the PAd-PWP from 34.5 +/- 0.9 to 24 +/- 2 mm Hg (mean +/- 1 SE). In group B a less significant change in these measurements was observed. Group A patients underwent VSD repair, and the mean average postoperative decrease in PAP was 31 mm Hg (P less than 0.001). Our findings suggest that in patients with VSD and severe PAH, in whom surgical treatment is controversial, a trial with isoproterenol should be routinely attempted. If the preceding hemodynamic parameters improve significantly, the VSD repair should be performed.

Adolescent↗
PubMed1981

Format effects in two teacher rating scales of hyperactivity.

The object of this study was to investigate the effect of differences in format on the precision of teacher ratings and thus on the reliability and validity of two teacher rating scales of children's hyperactive behavior. Teachers (N = 242) rated a sample of children in their classrooms using rating scales assessing similar attributes with different formats. For a sub-sample the rating scales were readministered after 2 weeks. The results indicated that improvement can be made in the precision of teacher ratings that may be reflected in improved reliability and validity.

Attention Deficit Disorder with Hyperactivity↗
PubMed1981

Extrinsic allergic alveolitis caused by pigeon breeding at a high altitude (2,240 meters). Hemodynamic behavior of pulmonary circulation.

The hemodynamic characteristics of the pulmonary circulation were examined in 10 patients with proved extrinsic allergic alveolitis caused by pigeons (EAA-P) raised at a high altitude. All patients had lung biopsies that showed an interstitial inflammatory response with vascular lesions. At rest, all patients had mean pulmonary pressures (PAP) greater than 16 mmHg; the average PAP was 22 +/- 12 mmHg for the whole group. Pulmonary vascular resistance was high and the mean for the whole group was 225 +/- 25 d.s.cm-5. The pulmonary artery diastolic-pulmonary wedge pressure (PAd-PWP) difference was elevated and averaged 8.5 +/- 2 mmHg. All patients were hypoxemic with elevated AaDO2. With exercise, both PAP and PAd-PWP increased abnormally. While breathing oxygen (FIO2, 99.6%) PAP decreased an average of 7 mmHg (p less than 0.05) and PAd-PWP decreased an average of 5 mmHg (p less than 0.05) without a significant change in PWP. The calculated compliance of the elastic pulmonary arteries in EAA-P was not different from that in normal subjects. Alveolar hypoxia produced mainly by EAA-P and presumably enhanced by living at a high altitude appeared to be the factors in the genesis of pulmonary hypertension, because pulmonary artery diastolic pressure and PAd-PWP difference were correlated with arterial oxygen saturation.

Adult↗