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Biomedical subjects

J Salas

Publications and source records attributed to J Salas.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Detection of residual ischemia after acute anterior myocardial infarction using Thallium-201 SPECT].

OBJECTIVES: To assess the utility of single photon emission computed tomography (SPECT) with Thallium-201 after anterior myocardial infarction at predischarge time in the detection of; a) the prevalence of isotopic redistribution in the infarct area or at a distance; b) the correlation between peri-infarction ischemia and the angiographic state of the infarct-related artery, and c) the correlation between ischemia at a distance and the presence of multivessel disease. MATERIAL AND METHOD: Seventy-three survivors of an uncomplicated anterior myocardial infarction, 67 men and 7 women, with a mean age of 56 +/- 9 years (34-70 range), underwent T1-SPECT after stress test (62 exercise test and 11 pharmacological Dipyridamole test) as well as coronarographic studies before discharge. Peri-infarction ischemia was defined as redistribution presence in the distribution territory of the left anterior descending artery (LAD) and was assessed in a semi-quantitative way scoring both stress and rest images that allowed the calculation of a redistribution index R (Stress Score-Rest Score/Stress Score). Ischemia at a distance was defined as redistribution presence in the territories of circumflex and right coronary arteries as assessed both by visual analysis (VA) and bull's eye polar maps (BE) or by washout imaging (WO). RESULTS: Peri-infarction ischemia (R > 0) was found in 48 (65.7%) patients; 43 with and 5 without significant residual lesions in the LAD and the absence of peri-infarction ischemia (R = 0) was found in 25 (34.3%) patients, 19 with and 6 without significant residual lesions in the LAD. Sensitivity and specificity for multivessel disease detection by ischemia at a distance was 64% and 85% respectively, for VA; 60% and 77% for BE; and 95% and 65% for WO. Combinations of different analytical methods (multiparametric approach) showed a decrease in sensitivity but improved specificity and positive predictive value: 60%, 90% and 75%, respectively, for BE & WO; 44%, 90% and 69% for VA & BE and 60%, 92% and 79% for VA & WO. CONCLUSIONS: TI-SPECT imaging is a useful diagnostic method to detect both peri-infarction ischemia and ischemia at a distance at predischarge time following anterior myocardial infarction. Redistribution presence in the non infarct-area shows a fair sensitivity and a high positive predictive value to detect residual multivessel disease.

Adult↗
PubMed1996

[Follow-up of left ventricular systolic function in the first year following previous infarction].

OBJECTIVES: To follow the left ventricular systolic function changes as assessed by global and regional ejection fraction during the first year of evolution after anterior myocardial infarction, as well as to analyse how the most relevant clinical and angio-graphic parameters influence them. MATERIALS AND METHODS: Sixty-six consecutive patients with a first infarction of anterior location, completed 1 year of follow-up with radionuclide ventriculography, T1-SPECT after exercise or dypiridamole and cardiac catheterization before discharge; radionuclide ventriculography was repeated 6 and 12 months later. Twenty-five patients underwent revascularization procedures at the time of predischarge, 16 using successful percutaneous angioplasty of the left anterior descending artery and 9 using aorto-coronary graft surgery. Dilated patients were controlled, from an angiographic point, of view 6 months after PTCA. RESULTS: Predischarge global EF (42.9 +/- 12.6) increased significantly between the 6-month (46.9 +/- 12.8; p < 0.001) and 12-month (47.6 +/- 12; p < 0.001) studies. Differences in these two last studies were minor and had no statistical significance. A significant increase was present in revascularized or medically treated patients; i.e. those who underwent thrombolytic therapy or conventional treatment at admittance as well as mono or multivessel disease patients. No significant differences were detected in the mean ejection fraction in patients without residual stenosis in the infarct-related artery (48.1 +/- 13.3 vs 50 +/- 12.6; NS) or those presenting a pre-discharge ejection fraction > or = 45% (53.5 +/- 7.5 vs 55.1 +/- 3.3; NS). Among different variables tested, predischarge global ejection fraction (negative coefficient) and, to a lesser extent, percutaneous angioplasty were independent predictors of a significant increase of ejection fraction during follow-up. Changes from predischarge to 12 month study were significant in the regional ejection fraction in the anteroseptal (33.1 +/- 14.7 vs 40.1 +/- 13.3; p < 0.001), inferoseptal (34.6 +/- 15.8 vs 42 +/- 16.9; p < 0.001), apical (46.3 +/- 19.1 vs 50.8 +/- 19.7; p < 0.01), antero-medial (50.6 +/- 22.4 vs 56.6 +/- 24.3; p < 0.01) and anteroapical (51.6 +/- 23.5 vs 58 +/- 27.5; p < 0.01) segments. In the anterobasal segment, regional ejection fraction only showed a statistical tendency to increase during follow-up and changes in inferior and lateral segments, distal to the infarcted area, were minor and without statistical significance. The most distinct infarct-related segments, antero- and inferoseptal, showed significant increases in the main group of patients, revascularized or nonrevascularized, undergoing thrombolitic or conventional therapy, with single or multivessel disease. Only patients without residual stenosis of the infarct-related artery (the left descending anterior) disclosed negligible or negative changes without statistical significance. Percutaneously dilated patients showed the highest increase of the infarct-related segments regional ejection fraction. In multivessel disease, the infarct-related segments regional ejection fraction did not increase significantly in surgically treated patients, conversely to those who underwent medical therapy. CONCLUSIONS: Global and regional ejection fraction of the infarcted area increased significantly during the first year after anterior myocardial infarction, mainly prior to six months patients with significant residual stenosis of the artery related to the infarct. Recovery is present both in patients who underwent thrombolysis or conventional treatment at admittance and revascularization or medical treatment before discharge and is inversely correlated to the predischarge global ejection fraction value. This evolution suggests that a significant amount of stunned myocardium is still present before discharge.

Adult↗
PubMed1995

Perineural spread of cutaneous squamous cell carcinoma manifesting as ptosis and ophthalmoplegia (orbital apex syndrome).

This paper reports two cases of orbital apex syndrome. The most salient clinical signs, ophthalmoplegia and eyelid ptosis, arose from perineural spread of facial squamous cell carcinomas that were previously excised with tumour-free surgical margins and exhibited no signs of local or other regional recurrence. The interest of these two cases lies in the fairly rare occurrence of this type of tumour spread and the highly aggressive nature of the tumour, unequivocal diagnosis of which usually arrives too late for a surgical solution. Awareness of the possibility of such perineural spread may allow the clinician to establish an early diagnosis and thus undertake radical surgery, thereby increasing the likelihood of success in combination with postoperative radiotherapy.

Aged↗
PubMed1995

Reversal of digital clubbing after lung transplantation.

Digital clubbing is a common sign in a variety of lung diseases. Although its pathogenesis remains unclear, it is known that the degree of clubbing might vary and even disappear, particularly when the underlying disease is a malignant neoplasm that has been removed. By contrast, because of the short expectancy of life in patients with pulmonary fibrosis, it is unusual to observe regression of clubbing. In this work, we report a case of reversible clubbing after lung transplantation.

Adult↗
PubMed1994

Influence of mutation in human apolipoprotein A-1 gene promoter on plasma LDL cholesterol response to dietary fat.

The plasma lipid response to changes in dietary fat and cholesterol can vary between individuals. At present, responders cannot be identified in advance. An adenine to guanine (A-->G) mutation in the promoter of the apolipoprotein A1 gene (apoA-1) has been suggested as affecting plasma high-density lipoprotein cholesterol. In 50 young men we examined the effect of the same mutation on the responses of both high and low density lipoprotein cholesterol to low-fat diet. The frequency for the A allele was 0.14. Subjects were fed a low-fat diet for 25 days, followed by a diet rich in monounsaturated fatty acid (MUFA, 22% out of 40% fat) for 28 days and lipoproteins were measured at the end of each diet. There were no differences in initial total cholesterol between subjects with the G/G mutation (170 mg/dL: 100 mg/dL = 2.59 mmol/L) and the G/A mutation (169 mg/dL) genotypes. After consumption of the high monounsaturated fat diet, significant increases were noted in plasma LDL cholesterol (10 mg/dL, p = 0.035) in the G/A subjects but not in the G/G subjects (1 mg/dL, p = 0.996). These differences showed that a significant diet-gene interaction (p = 0.015) existed. No differences were observed on HDL cholesterol between groups. Plasma low-density lipoprotein cholesterol responsiveness to diet may be explained by variation at the apoA-I gene locus.

Adult↗
PubMed1994

A retrospective analysis of tissue-fixed immunoreactants from skin biopsies maintained in Michel's medium.

656 skin biopsies with positive direct immunofluorescence from the UK and overseas were studied over a 2-year period. The length of time biopsies had remained in Michel's medium at pH 7.0 in various diseases (pemphigoid, pemphigus, linear IgA disease, epidermolysis bullosa acquisita, lupus erythematosus, vasculitis, amyloid, lichen planus and dermatitis herpetiformis) was analysed. We concluded that direct immunofluorescence remained positive at 6 months and that Michel's medium is a reliable long-term maintenance medium for skin biopsies.

Autoimmune Diseases↗
PubMed1993

Leucine metabolism at graded amino acid intakes in children receiving parenteral nutrition.

To assess the response of protein turnover to graded levels of amino acid (AA) intakes, leucine kinetics were determined in six 8- to 16-yr-old patients in a stable nutritional status receiving home parenteral nutrition (PN) for short-bowel syndrome or intestinal pseudo-obstruction syndrome. Although daily energy intake was kept constant at 68.7 +/- 13 kcal/kg lean body mass (LBM) with 25.4 +/- 3.6% lipid, patients were given, for three consecutive 7-day periods, 0.7, 1.5, or 2.5 g AA.kg LBM-1.day-1, with the order of the regimens being randomized. On day 7 of each period, a 4-h infusion of L-[1-13C]leucine was performed during intravenous feeding; plasma [13C]ketoisocaproate and expired 13CO2 enrichments were used to assess whole body leucine turnover (Ra), oxidation rate (Ox), nonoxidative disposal [an estimate of protein synthesis (S)], and leucine derived from protein breakdown (B). Urine collection (24 h) was performed for determination of nitrogen excretion. Results indicate a dose-dependent rise in plasma leucine concentration, Ra, and Ox but no significant change in B. There was a significant increase of S (P = 0.04 analysis of variance) with increased AA intakes as well as net leucine balance (P = 0.02). Results are consistent with improved leucine balance, when leucine intake increases, despite increased leucine oxidation. The net protein gain observed with higher AA intakes may suggest a beneficial effect for children receiving long-term PN.

Adolescent↗
PubMed1993

Mortality in Mexican patients with chronic pigeon breeder's lung compared with those with usual interstitial pneumonia.

The clinical course of chronic pigeon breeder's lung (CPBL) is unknown, especially in comparison with usual interstitial pneumonia (UIP). We studied a cohort of 125 consecutive patients with interstitial lung diseases, including 78 patients with CPBL (74 biopsied) and 47 patients with UIP in the lung biopsy. Patients with UIP were divided into 17 without bird exposure (UIP) and 30 with bird exposure (UIP + BE). All patients were treated with corticosteroids and followed for 33 +/- 23 months. The best predictors of mortality (Cox proportional hazards model) were age > 44 yr, with a relative risk (RR) of 2.5 and 95% confidence interval (CI) of 1.4 to 4.7, masculine gender (RR 4.0, CI 2.1 to 7.6), x-ray honeycombing (RR 7.0, CI 3.8 to 12.7), and severity of fibrosis in the lung biopsy (RR 4.8, CI 2.3 to 9.7). Survival in CPBL 5 yr after diagnosis was 0.71 (SEM 0.08) and in UIP was 0.23 (SEM 0.08), with no statistical difference between UIP + BE and UIP. After adjusting for severity of fibrosis and honeycombing, however, the correlation of diagnosis with survival disappeared. In conclusion, mortality in CPBL is considerable, but lower than in UIP. Lung fibrosis and honeycombing seem to be a final common pathway for the ILD. Adjusting for them, the effect of diagnosis in survival is not significant.

Adult↗
PubMed1993

Pulmonary arterial hypertension and cor pulmonale associated with chronic domestic woodsmoke inhalation.

We describe the clinical, radiologic, functional, and pulmonary hemodynamic characteristics of a group of 30 nonsmoking patients with a lung disease that may be related to intense, long-standing indoor wood-smoke exposure. The endoscopic and some of the pathologic findings are also presented. Intense and prolonged wood-smoke inhalation may produce a chronic pulmonary disease that is similar in many aspects to other forms of inorganic dust-exposure interstitial lung disease. It affects mostly country women in their 60s, and severe dyspnea and cough are the outstanding complaints. The chest roentgenograms show a diffuse, bilateral, reticulonodular pattern, combined with normalized or hyperinflated lungs, as well as indirect signs of pulmonary arterial hypertension (PAH). On the pulmonary function test the patients show a mixed restrictive-obstructive pattern with severe hypoxemia and variable degrees of hypercapnia. Endoscopic findings are those of acute and chronic bronchitis and intense anthracotic staining of the airways appears to be quite characteristic. Fibrous and inflammatory focal thickening of the alveolar septa as well as diffuse parenchymal anthracotic deposits are the most prominent pathologic findings, although inflammatory changes of the bronchial epithelium are also present. The patients had severe PAH in which, as in other chronic lung diseases, chronic alveolar hypoxia may play the main pathogenetic role. However, PAH in wood-smoke inhalation-associated lung disease (WSIALD) appears to be more severe than in other forms of interstitial lung disease and tobacco-related COPD. The patients we studied are a selected group and they may represent one end of the spectrum of the WSIALD.

Blood Pressure↗
PubMed1993

[Malignant vasovagal syncope: its diagnosis and therapeutic trial based on the orthostatism test (the tilt-table test)].

Seventy consecutive patients with recurrent unexplained syncope were evaluated by use of an up-right tilt-table test for 45 minutes (with or without an infusion of isoproterenol) in an attempt to reproduce symptoms. There were 42 males and 28 females with a mean age of 49 +/- 20 years (range 7-86), and with a mean symptoms duration of 35.2 +/- 16 months. All the patients underwent clinical examination which includes cardiological and neurological evaluation. Some tilt positive patients received therapy with either transdermal scopolamine, metoprolol or clonidine, the efficacy of which was evaluated by another tilt-table test. Syncope occurred in sixteen patients (22.9%), during the baseline tilt associated with hypotension (2 patients), bradycardia-asystolia (3 patients), or both (11 patients). In 11 patients with normal baseline tilt test, isoproterenol infusion was used appearing 4 new cases of abnormal response. Some patients who had positive test results, eventually became tilt-table negative by therapy (5 out of 8 patients treated with scopolamine, 5 out of 6 patients with metoprolol, and 3 out of 5 patients with clonidine). Time before syncope during tilt-test was increased with therapy, being of 45 min in normalized cases, and increasing from 11.9 +/- 16 basal to 34.4 +/- 17 min with scopolamine (p < 0.05), to 40 +/- 12 min with metoprolol (p < 0.05) and to 33.7 +/- 16.7 min with clonidine (p = NS). We conclude that upright tilt-table alone or combined with isoproterenol infusion is an useful test in the diagnosis of vasovagal syncope and in the evaluation of therapy.

Adolescent↗
PubMed1992

Role of the host cell nucleus in the replication of African swine fever virus DNA.

An examination by autoradiography of African swine fever virus-infected alveolar macrophages pulse labeled with [3H]thymidine showed that, at early times of viral DNA replication, the grains were localized exclusively in the nucleus in 20% of the cells, while in 45% the label was found in the cytoplasm. In the remaining 35%, newly synthesized DNA was detected in both the nucleus and the cytoplasm. At later times, the percentage of cells with grains in the nucleus decreased considerably. Pulse-chase experiments indicated that the DNA synthesized in the nucleus is then transported to the cytoplasm. The presence of virus-specific DNA sequences in the nucleus was confirmed by in situ hybridization of infected macrophages. Similar hybridization experiments with African swine fever virus-infected VERO cells followed by confocal microscopy also indicated the existence of a nuclear stage in the localization of the viral DNA. These results suggest a mechanism for African swine fever virus DNA replication with an initial stage in the nucleus followed by a cytoplasmic phase. Specific nuclear forms associated with the hybridization signal have been observed in African swine fever virus-infected macrophages and VERO cells. The nuclear forms seen in macrophages are consistent with a mechanism for the egress of the viral DNA from the nucleus that involves initial budding at the nuclear membrane.

African Swine Fever Virus↗
PubMed1992

Absorption of Intralipid and interferences from nutrients infused into the peritoneal cavity of the rat.

We studied the peritoneal absorption and elimination of Intralipid after its intraperitoneal and intravenous infusion into rats, by means of a two-compartment model. Follow-up measurements of the plasma triglyceride rate were made. The peritoneal absorption of Intralipid gives the following absorption and elimination constants: Ka (absorption constant from the peritoneal cavity) is 0.106 +/- 0.08 h-1; Ke (elimination constant from the blood stream) is 0.0440 +/- 08 h-1; and BAa (absolute bioavailability) is 84.5 +/- 0.08% 8 hours after infusion. These results show that the intraperitoneal absorption of Intralipid is high and progressive during the first 8 hours, thus supplying the daily caloric needs of the animal through the administration of a single bolus administration, and the plasma triglyceride clearance is faster than the intraperitoneal absorption after the first 6 hours, thus avoiding dangerous overloads. We also studied the behavior of different combinations of glucose, amino acids, and fats infused into the peritoneal cavity of rats in order to observe possible interferences with the absorption of these nutrients. Two microcuries of radioactive L-glucose-1-C14 with 5 mL of 5% D-glucose, with 5 mL of 3.5% amino-acid solution, or with 5 mL of 20% fat emulsion were infused intraperitoneally into three different groups of animals. Slight differences of plasma radioactivity were registered among these three groups 1 hour after infusion. Likewise, small differences of plasma radioactivity were observed between the animals receiving an infusion of 1 microCi of five L-amino-acids-U-C14 diluted with 5 mL of 3.5% amino-acid solution, with 5 mL of 5% glucose solution, or with 5 mL of 20% fat emulsion 4 and 6 hours after infusion. No differences in the plasma triglyceride rates were observed between those groups of animals infused with 5 mL of 20% Intralipid plus 5 mL of glucose solution or with 20% Intralipid plus 3.5% amino-acid solution compared with the group receiving only 5 mL of 20% Intralipid. The infusion of fats does not seem to interfere with that of other substrates, possibly because of the different absorption route (lymphatic for fats and capillary vessels for amino acids and glucose solutions), but further research is needed to reach conclusive results. Perhaps the prolonged administration of fat, together with other substrates, produces precipitates and other galenic problems that hinder absorptive mechanisms of the preparations.

Absorption↗
PubMed1992

Prevalence of high hematocrits in patients with interstitial lung disease in Mexico City.

Erythrocytosis, a known response to chronic hypoxemia, is considered infrequent in interstitial lung diseases. We studied the prevalence of high hematocrit (Hct) values and the relationship between Hct and SaO2 in 79 patients with chronic pigeon breeder's lung (PBL) and 34 with idiopathic pulmonary fibrosis (IPF), all of whom lived in the Mexico City metropolitan area (2,240 m above sea level). Lung biopsy was performed in 31 patients with IPF and 71 with PBL. We analyzed only one simultaneous measurement of Hct and SaO2 per patient (usually the initial measurement) before treatment. No additional cause for anemia or erythrocytosis was detected. Forty-eight percent of the patients with PBL (38/79) and 62 percent of those with IPF (21/34) had high Hct values (greater than 2 SD above mean values for Mexico City); in 14 (12.3 percent) of the 113 patients (nine with PBL and five with IPF), the Hct was above 60 percent. The Hct and SaO2 values displayed a poor correlation for the whole group: Hct = 65.7-0.16(SaO2), r = 0.24, p = 0.012. The correlation between Hct and SaO2 was nonsignificant if patients were separated by diagnosis. For an SaO2 of less than 80 percent, the slope of SaO2 vs Hct was zero. Half of our patients with PBL and IPF had Hct values that were high for the altitude. In most cases, Hct responses fell within the confidence limits reported as normal at high altitudes. We found a poor relationship between Hct and awake SaO2.

Altitude↗
PubMed1992

The influence of nutrient intake on the biochemical parameters of iron status in a healthy paediatric Mediterranean population.

A random sample of 302 children, aged between 6 months and 15 years, of a healthy Mediterranean population were studied. Abnormal values of biochemical parameters of iron status were frequently found. In the 0.5-2 year group, erythrocyte protoporphyrin values were abnormal in 13.5% of subjects, serum ferritin in 9.7%, transferrin saturation capacity in 75.3%, mean red cell volume in 4.1% and haemoglobin in 9.7%. Comparing nutritional intake (24 h dietary recall over 3 days) between individuals at low and high values of biochemical iron status some significant differences were found in each age group but in no case with regard to heme iron intake. In the overall age-adjusted study population, the nutritional intake had a low but significant explanatory capacity of the variance of the measured biochemical iron status parameters (between 1.1% for transferrin saturation capacity and 4.5% for serum ferritin) and a non-significant capacity in those children younger than 3 years. In conclusion, although the dietary pattern in our area favours a good iron bioavailability, in our population the nutritional intake was shown to have a limited relationship with the parameters of biochemical iron status parameters. These data suggest that, in healthy children, abnormal biochemical iron status parameters may be related to factors other than nutritional intake.

Adolescent↗