Publications by authors named "Chavez A"

Ischemic stroke constitute a mayor cause of morbidity and mortality in the adult population, particularly in the elderly. Heart disease may predispose to ischemic stroke, especially in the presence of transient or permanent precipitating factors such as atrial fibrillation. To elucidate the role of heart disease in predisposing to ischemic stroke we studied the clinical and non invasive cardiac profile (EKG, 2D-Echo, Holter) of 186 consecutive patients, 91 of them embolic (GI) and 96 non embolic (lacunar, atherothrombotic, others) (GII), as determined by brain CT scan and thorough clinical evaluation.

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To determine the prevalence and causes of anemia in rural Mexico, blood samples and longitudinal dietary data were collected from 187 women, some pregnant and then lactating, and from 72 men. Blood was used to measure anemia, mean cell volume, and plasma ferritin, folate and vitamin B-12. Anemia was found in 33% of the men, 54% of nonpregnant, nonlactating women, 35% of pregnant women and 41% of lactating women, and varied by season.

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An endobronchial tumor, resected from a 77-year-old man, had an endometrioid histologic pattern consistent with fetal adenocarcinoma. A distinctive feature of the neoplasm was prominent neuroendocrine differentiation, including single, discrete neuroendocrine cells; aggregates of neuroendocrine cells resembling miniature carcinoid tumors; and a single focus of undifferentiated small cell carcinoma. Immunohistochemical staining of neuroendocrine cells revealed the presence of neuron-specific enolase, chromogranin, somatostatin, insulin, and serotonin.

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The renin/angiotensin system (RAS) is a tonic anti-drop regulator of arterial blood pressure in many teleosts. In trout, angiotensin II (ANG II) has no direct constrictor effect on large arteries or veins and the identity of specific cardiovascular pressor effectors is unknown. Potential targets of angiotensin activation were examined in the present experiments using perfused organs and isolated tissues from the rainbow trout Oncorhynchus mykiss.

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This research was carried out in a sample of 96 adults from a rural community undergoing a socioeconomical transition with the aim of evaluating their risk of atherosclerosis. Total cholesterol, HDL, LDL and triglycerides levels were measured in blood and a simplified food intake questionnaire was applied. A sample of 116 middle class urban subjects of similar age and sex were studied to compare the data.

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Cerebrovascular accidents (CVA) constitute a major cause of adult cardiac cardiovascular mortality in Chile. From July 87 to August 89 we prospectively studied 300 patients with CVA utilizing a multidisciplinary approach. Besides clinical evaluation this included brain CT scan (48 hrs), glucidic and lipid profile.

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Predictors of attained size at 30 mo and growth rate between 18 and 30 mo (eg, diet, maternal size, morbidity, age at weaning, and selected environmental factors) were investigated by using longitudinal data from 67 Mexican children aged 18-30 mo. These children were small because of growth stunting in early infancy. Between 18 and 30 mo they grew on average at the 50th percentile of National Center for Health Statistics references values for weight, and the 25th for length.

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The purpose of this study was to define the risk factors for systemic embolism in patients with recently diagnosed paroxysmal atrial fibrillation. We therefore studied 63 consecutive patients with symptomatic nonvalvular paroxysmal atrial fibrillation and performed a clinical and noninvasive cardiac, peripheral vascular, and neurologic evaluation that included two-dimensional echocardiography, 24-hour Holter monitoring, and computed tomographic brain scan. Patients with predisposing clinical conditions for systemic embolism (valvular heart or coronary artery disease) or paroxysmal atrial fibrillation (sick sinus disease, preexcitation, or thyroid dysfunction) were excluded.

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The purpose of this study was to compare the effect of nutritional intake during tooth-crown formation on the subsequent development of linear enamel hypoplasias (LEHs) in Mexican nonsupplemented (control) adolescents (n = 42) and adolescents who had received daily nutritional supplements since birth (n = 42). The proportion of individuals with LEHs was nearly two-fold greater (74.4%; 95% CI 64.

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The aim of comparative research in social epidemiology is to determine how risk factors for disease may vary within and between sociocultural and ethnic groups and in relation to outcomes. This aim assumes that measurement equivalence within and between social groups can be established, an assumption usually left untested. A model is presented here for deriving cross-culturally valid measures that are also intraculturally sensitive.

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Large household size is widely regarded as a risk factor for malnutrition in developing countries, particularly for infants and young children. This study examines the extent to which household size is related to nutritional status in school-age children in the Solis Valley in highland Mexico. The relationships of food intake, anthropometric measures, and household size are assessed in a sample of 110 children (7-9 years of age), who were followed longitudinally for a minimum of one year as part of the Collaborative Research Support Program on Food Intake and Human Function.

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Blood conservation.

Semin Thorac Cardiovasc Surg

October 1990

The importance of blood conservation to minimize homologous blood use after cardiac surgery is well-accepted. The most successful programs to this end are the products of an integrated approach to blood conservation that begins with preoperative patient screening and carries through the postoperative period. Salvage and reinfusion of shed blood both intra- and postoperatively are important components of any such program.

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Ketanserin, a serotonergic S2-receptor antagonist, was used in a prospective study in nine hypertensive patients with ECG criteria of left ventricular hypertrophy (LVH). Echocardiographic measurement with M mode was made after 1 month of placebo, and after 3, 6, and 12 months of ketanserin treatment as monotherapy at a mean dose of 31 mg bid. Ketanserin treatment decreased mean left ventricular mass by 9.

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Rosner et al. presented a simple, easily implemented modelling method for retaining time order relationships in analyses of longitudinal data when successive measures are correlated. Evaluation of time order is particularly useful in epidemiologic studies concerned with exposure to potentially toxic substances and subsequent outcome, but may also have use in more traditional growth studies that relate intake to subsequent development.

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Recent literature provides evidence that Non-Q wave myocardial infarction (Non-Q MI) has a different intrahospital course and prognosis than Q-wave myocardial infarction (Q-MI). We evaluated clinical and laboratory characteristics, complications and therapeutic requirements of 557 consecutive patients, 440 with Q-MI and 117 with Non-Q MI. Risk factors for coronary artery disease did not differ among groups.

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An outpatient study of 125 children with acute invasive diarrhea was conducted at the Hospital Infantil de Mexico Federico Gomez. Through a single-blind randomization, we compared the efficacy of furazolidone, 7.5 mg/kg/day (49 patients), with trimethoprim-sulfamethoxazole (TMP-SMX), 8 mg/40 mg/kg/day (52 patients), each given for 5 days.

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Body weight at calving, degree of tick load (Boophilus microplus), rectal temperature, respiratory frequency and heart rate were evaluated and correlated to reproductive efficiency in 63 F1 Brown Swiss x Nellore milked animals reared in the tropical region of Peru. Cows were bred by free natural service, and first ovulation was estimated by progesterone measurements. The physiological parameters were registered at morning milking (04.

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Mitral valve prolapse is an increasingly common etiology among patients presenting for mitral valve surgery. From 1985 through 1987, a total of 457 patients underwent surgery for pure mitral regurgitation. Of these, 304 (67%) had underlying mitral prolapse, 57 (12%) had rheumatic valvulitis, 36 (8%) had underlying ischemic disease, and 22 (5%) had bacterial endocarditis.

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Records of 520 patients who underwent mitral valve operations were reviewed to determine the pathophysiology, etiology, anatomy of the valve lesion and use of valvuloplasty techniques. Pure mitral regurgitation, present in 269 patients (52%), was the most common lesion while rheumatic valvulitis, seen in 286 patients (55%), was the most common etiology. Degenerative lesions were found in 168 patients, 33% of the total and 63% of the pure mitral regurgitation group.

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Limbic cholinergic activity is critically involved in the retention of learned aversions tasks. The purpose of these experiments was to assess the role of cholinergic mechanisms of the dorsal hippocampus in the acquisition of both odor and potentiated odor aversions through taste aversion. Cholinergic activity was increased by physostigmine (Phys).

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Enamel hypoplasias, deficiencies in enamel thickness resulting from disturbances during the secretory phase of enamel development, are generally believed to result from nonspecific metabolic and nutritional disruptions. However, data are scare on the prevalence and chronological distributions. of hypoplasias in populations experiencing mild to moderate malnutrition.

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