Ichthyofauna diversity of Taperoá II reservoir, semi-arid region of Paraíba, Brazil.

To determine the fish species present in Taperoá II Reservoir, and their relevance to the local economy, this research aimed to evaluate the composition, abundance, degree of dominance and constancy of species, along with diversity, richness, evenness and similarity indices in a tropical semi-arid fish assemblage, during one year. Six 24 hour-long samplings were carried out between October 2005 and October 2006 using cast, seine and gillnets. The 889 collected individuals belonged to 11 species from 9 families. Temporal variation was observed in the capture frequency of different species, and a significant negative correlation between precipitation and number of individuals was also observed. Among the recorded families, Characidae showed a higher frequency of occurrence (38.4%), mostly due to Astyanax bimaculatus (Linnaeus, 1758) and A. fasciatus (Cuvier, 1819). Eight species were categorised as constant, two as accessory and one as accidental. Diversity index values were intermediate with low fluctuation throughout the study period, and no correlation with precipitation or water volume. However, the greatest diversity value was recorded in March 2006, when the peak of the precipitation was recorded. Evenness values showed a similar trend to the diversity index.

Influence of left ventricular hypertrophy on detection of coronary artery disease using exercise echocardiography.

OBJECTIVES: This study examined the influence of left ventricular hypertrophy on the accuracy of exercise electrocardiography and echocardiography for detection of coronary artery disease. BACKGROUND: Electrocardiographic repolarization abnormalities caused by left ventricular hypertrophy compromise the diagnostic accuracy of exercise electrocardiography but not of exercise echocardiography. The relative merits of these investigations are less well defined in patients with hypertrophy but without electrocardiographic (ECG) changes. METHODS: We prospectively evaluated 147 consecutive patients without prior myocardial infarction undergoing both exercise echocardiography and coronary arteriography. Coronary stenoses > 50% diameter were present in 62 patients (42%). Positive test results were defined by a new or worsening wall motion abnormality or > 0.1 mV of ST depression. Echocardiographic left ventricular hypertrophy (mass > 131 g/m2 in men, > 100 g/m2 in women) was identified in 68 patients. A subgroup with clinically suspected hypertrophy was defined according to the presence of ECG evidence of hypertrophy, hypertension or aortic stenosis. RESULTS: The overall sensitivity of exercise echocardiography exceeded that of exercise electrocardiography (71% vs. 54%, p = 0.06). Echocardiographic hypertrophy had no significant effect on the sensitivity of either test. The specificity of exercise echocardiography exceeded that of exercise electrocardiography (91 vs. 74%, p = 0.01). In patients with hypertrophy, the specificity of exercise echocardiography exceeded that of exercise electrocardiography (95% vs. 69%, p < 0.01), whereas among patients without hypertrophy, the specificities (respectively, 87% and 78%) were more comparable. The accuracy of exercise echocardiography exceeded that of the exercise ECG in the overall group (82% vs. 65%, p = 0.002) and in patients with hypertrophy (85% vs. 60%, p = 0.004), but this difference was less prominent in patients without hypertrophy (80% vs. 69%, p = NS). In patients with clinically suspected hypertrophy, exercise echocardiography demonstrated a higher sensitivity, specificity and accuracy than exercise electrocardiography. The cost incurred in the identification of coronary disease was least with a strategy involving use of the exercise echocardiogram instead of routine exercise testing in patients with known or clinically suspected left ventricular hypertrophy. CONCLUSIONS: Exercise echocardiography is more accurate than exercise electrocardiography for the detection of coronary artery disease in patients with known or clinically suspected left ventricular hypertrophy.

Detection of fibrous strands on prosthetic mitral valves with transesophageal echocardiography: another potential embolic source.

Patients with prosthetic mitral valves (MVR) have an increased incidence of cardiac embolic events, but the causes of these emboli have not been determined. Fibrous strands, detected by transesophageal echocardiography (TEE) on the left atrial side of MVRs, may be embolic precursors in these patients. However, the incidence and clinical significance of these strands are unknown. We reviewed the charts of 76 consecutive patients with MVRs who underwent a total of 83 TEE studies between January 1991 and January 1992. Of the 83 studies, 39 (47%) were of bioprostheses and 44 (53%) were of mechanical prostheses. Strands were found in 15 studies (18%) and were significantly more common in mechanical prostheses (32% vs 3%; p < 0.001). Embolic events occurred in 53% of patients with strands compared with only 18% of those without (p < 0.01). Strands were not associated with left atrial spontaneous echo contrast, left atrial thrombi, infection, prosthetic stenosis, severity of regurgitation, or left ventricular function. No physical evidence of these strands was found in the one native and three prosthetic valves examined visually during the study at the time of surgery. The data support the hypothesis that TEE evidence of strands is associated with a higher incidence of embolic events and indicate the potential for formation of intracardiac emboli on MVRs.

Left atrial tamponade: diagnosis by transesophageal echocardiography.

A 60-year-old white man became hypotensive and dyspneic 3 days after right pneumonectomy for bronchogenic carcinoma. Transthoracic echocardiography was nondiagnostic because of technical difficulty. Transesophageal echocardiography demonstrated a loculated posterior pericardial effusion with isolated diastolic left atrial collapse. The hemodynamic disturbance resolved after drainage of the effusion. Transesophageal echocardiography plays a valuable role in the diagnosis of postoperative cardiac tamponade.

Elimination of glucose interference and improved precision in a continuous-flow analysis for inulin.

A modified fermentation procedure based on one described by Homer Smith in his textbook was used to eliminate glucose interference in the automated detrmination of inulin. The manifold of Fjeldbo and Stamey [J. Lab. Clin. Med. 72, 353 (1968)] was modified to enable us to insert the fermentation procedure without sacrificing precision in continuous-flow analysis for inulin. Analytical recoveries of inulin from plasma and urine with the modified manifold were 100.1 +/- 0.8% (SD) and 99.9 +/- 1.6%. Corresponding recoveries of inulin from specimens of plasma and urine containing 5 g of glucose per liter and treated with yeast were 99.6 +/- 1.5% and 100.0 +/- 1.6%.