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Biomedical subjects

M Vargas

Publications and source records attributed to M Vargas.

At least 109 records · Page 6Linked to original sources
PubMed1987

Schistosomiasis mansoni in the Dominican Republic; prevalence and intensity in the city of Higuey by coprological and serological methods.

The prevalence and intensity of infection with Schistosoma mansoni were determined in a sample of the population of the city of Higuey, Dominican Republic. The quantitative formol-ether stool sedimentation technique of Ritchie, as modified by Knight et al., was performed on stools from 1,025 (65.5%) of 1,563 individuals greater than 1 year old. The highest prevalence rates (21.4%) were observed in women 25-29 years old and in men 15-19 years old (20%). The maximum fecal egg count was in the 15- to 19-year age group, with a geometric mean of 30 eggs/g feces among men and 15.8 eggs/g feces in men and women. The overall prevalence of S. mansoni-infection was 11.8% with a geometric mean excretion of 8.8 eggs/g feces. In addition, the circumoval precipitin test was carried out on 639 sera and 110 (17.2%) were positive, increasing the prevalence in all age groups. Examination of Biomphalaria glabrata snails collected in early 1986 showed 7.8% to be positive for S. mansoni cercariae. Despite the moderate prevalence rates and the low intensity of infection among the human population, we consider Higuey to be an important focus of schistosomiasis in the Dominican Republic. The sensitive coprological and serodiagnostic techniques we employed have helped to identify the age- and sex-specific groups most deserving of treatment in order to reduce transmission of infection and disease prevalence.

Adolescent↗
PubMed1978

An apparent outbreak of rickettsial illness in Costa Rica, 1974.

A focal outbreak of highly fatal disease occurred in eastern Costa Rica in 1974. No rickettsial spotted fevers have previously been reported in Costa Rica. Nevertheless, the available evidence points to an unidentified rickettsial pathogen, probably of the spotted fever group, as the agent responsible for this outbreak.

Adolescent↗
PubMed1976

Toxic amoebic colitis and amoebic colon perforation in children: An improved prognosis.

Fourteen children were treated for complications of severe colonic amebiasis. Seven had colon perforation; seven had toxic amoebic colitis. Those with perforation underwent colon resection limited to the perforation and adjacent abnormal colon. Those having toxic amoebic colitis without perforation were managed by temporary ileostomy. Vigorous general supportive treatment for endotoxic shopck and amebiasis was given pre and postoperatively. Careful barium enema examinations proved safe and effective in diagnosis and follow-up. Ten patients survived (72%), five from each group.

Barium Sulfate↗
PubMedDate not supplied

Electrophysiological characterization of murine myocardial ischemia and infarction.

BACKGROUND: Genetically altered mice will provide important insights into a wide variety of processes in cardiovascular physiology underlying myocardial infarction (MI). Comprehensive and accurate analyses of cardiac function in murine models require implementation of the most appropriate techniques and experimental protocols. OBJECTIVE: In this study we present in vivo, whole-animal techniques and experimental protocols for detailed electrophysiological characterization in a mouse model of myocardial ischemia and infarction. METHODS: FVB mice underwent open-chest surgery for ligation of the left anterior descending coronary artery or sham-operation. By means of echocardiographic imaging, electrocardiography, intracardiac electrophysiology study, and conscious telemetric ECG recording for heart rate variability (HRV) analysis, we evaluated ischemic and post-infarct cardiovascular morphology and function in mice. RESULTS: Coronary artery ligation resulted in antero-apical infarction of the left ventricular wall. MI mice showed decreased cardiac function by echocardiography, infarct-typical pattern on ECG, and increased arrhythmia vulnerability during electrophysiological study. Electrophysiological properties were determined comprehensively, but were not altered significantly as a consequence of MI. Autonomic nervous system function, measured by indices of HRV, did not appear altered in mice during ischemia or infarction. CONCLUSIONS: Cardiac conduction, refractoriness, and heart rate variability appear to remain preserved in a murine model of myocardial ischemia and infarction. Myocardial infarction may increase vulnerability to inducible ventricular tachycardia and atrial fibrillation, similarly to EPS findings in humans. These data may be of value as a reference for comparison with mutant murine models necessitating ischemia or scar to elicit an identifiable phenotype. The limitations of directly extrapolating murine cardiac electrophysiology data to conditions in humans need to be considered.

Animals↗
PubMedDate not supplied

Transesophageal echocardiographic diagnosis of cardiac rupture.

Cardiac rupture is a difficult pre-mortem diagnosis to make and is equally difficult to manage. Transesophageal echocardiography may be useful in expediting the diagnosis and in the management of cardiac rupture related to myocardial infarction.

Aged↗
PubMedDate not supplied

Growth and adiposity of term infants fed whey-predominant or casein-predominant formulas or human milk.

Growth, estimated composition of weight gained, and stool patterns of term infants who were fed either a whey-predominant formula or a casein-predominant formula in a random design and of breast-fed infants were compared. All infants (N = 111) were healthy, singleton products of uncomplicated pregnancies. Birth weights and other anthropometric measures in the first few days of life were not different among the three feeding groups. Formula or breast milk was the infants' principal source of energy from birth to age 16 weeks. Average energy intakes of formula-fed infants and change of intakes with age were similar in both groups at all ages. Feeding groups were not significantly different at any age in weight, length, weight or length gain, head circumference, skinfold measurements, upper arm fat area and muscle area, or estimated total body fat. Stools of infants on the whey-predominant formula differed from both the breast-fed and casein-predominant formula groups.

Adipose Tissue↗