Clinical and hemodynamic determinants of left ventricular dimensions

This study was designed to quantitate the influence of 20 clinical, hemodynamic, and volume determinants of left ventricular (LV) structure. Systemic hemodynamics, intravascular volume, and LV echocardiographic measurements were collected in a heterogeneous population of 171 patients. Stepwise multiple-regression analysis indicated that body weight and body-surface area were the most powerful determinants of LV chamber size, wall thickness, and muscle mass. Age, a pressure independent determinant of myocardial mass, had no influence on chamber size or LV function. Arterial pressure correlated best with the relative wall thickness and chamber volume. Intravascular volume was a major discriminator for chamber volume, LV mass, and velocity of circumferential fiber shortening. It is concluded that body weight, arterial pressure, intravascular volume, and age are each independent determinants of the LV dimension. Systolic pressure most closely correlated with relative wall thickness and thereby is the best predictor of degree of concentric LV hypertrophy

Characterization of macrofauna associated with articulated calcareous algae (Corallinaceae, rhodophyta) occurring in a hydrodynamic gradient on the espírito santo state coast, brazil

The aims of this study were to characterize the macrofauna associated with the articulated calcareous algae occurring on a hydrodynamic gradient off the Vitória metropolitan area, Espírito Santo State, Brazil, and to describe its temporal distribution. Physicochemical variables were measured in situ, and samples of sediment, water and phytal were taken from three sites along the coast in August and November 2005 (winter and spring, respectively) and in February and May 2006 (summer and fall, respectively). Twenty random samples were taken from the rocky surface in the lower midlittoral zone at each site, each season. Six species of articulated algae harboring 9,651 animal specimens distributed among 189 taxa were collected. The dominant taxonomic groups were Mollusca, Polychaeta and Crustacea. The main patterns revealed by statistical analysis related to differences in the abundance and richness at the sample sites, as well as to the correlation between the physicochemical variables and community distance matrices, indicating the importance of the physicochemical variables in the differentiation of the communities. Results also indicated that the variable which most influenced the physicochemical and community properties was the hydrodynamic character of the sites: a high level of hydrodynamism resulting in the calcareous algae´s sheltering a lower abundance and diversity of animal species than a lower level one.Os objetivos deste estudo foram caracterizar a macrofauna associada às algas calcárias articuladas num gradiente de hidrodinamismo no litoral da região metropolitana de Vitória, Espírito Santo, Brasil, e descrever a distribuição temporal. Variáveis fisicoquímicas foram medidas in situ, e amostras do sedimento, água e fital foram feitas em três pontos amostrais do litoral em agosto e novembro de 2005 (inverno e primavera, respectivamente) e fevereiro e maio de 2006 (verão e outono, respectivamente). Em cada ponto, e por estação do ano, foram obtidas 20 amostras aleatórias da superfície do costão rochoso na região do mediolitoral inferior. Seis espécies de algas calcárias articuladas foram coletadas e abrigaram 9.651 espécimes animais distribuídos em 189 táxons. Os grupos taxonômicos dominantes foram Mollusca, Polychaeta e Crustacea. Os principais padrões revelados pelas análises estatísticas foram diferenças na abundância e riqueza entre os pontos amostrais e correlação entre as variáveis fisicoquímicas e a comunidade, indicando que os parâmetros fisicoquímicos foram importantes para a caracterização destas. Os resultados indicaram ainda que a variável que mais influenciou as propriedades fisicoquímicas e da comunidade foi o grau de hidrodinamismo: locais com hidrodinamismo elevado permitem que algas calcárias abriguem uma menor abundância e diversidade de espécies animais do que locais com hidrodinamismo elevado

Brazilian coral reefs in a period of global change: A synthesis

Abstract Brazilian coral reefs form structures significantly different from the well-known reef models, as follows: (i) they have a growth form of mushroom-shaped coral pinnacles called "chapeirões", (ii) they are built by a low diversity coral fauna rich in endemic species, most of them relic forms dating back to the Tertiary, and (iii) the nearshore bank reefs are surrounded by siliciclastic sediments. The reefs are distributed in the following four major sectors along the Brazilian coast: the northern, the northeastern and the eastern regions, and the oceanic islands, but certain isolated coral species can be found in warmer waters in embayments of the southern region. There are different types of bank reefs, fringing reefs, isolated "chapeirões" and an atoll present along the Brazilian coast. Corals, milleporids and coralline algae build the rigid frame of the reefs. The areas in which the major coral reefs occur correspond to regions in which nearby urban centers are experiencing accelerated growth, and tourism development is rapidly increasing. The major human effects on the reef ecosystem are mostly associated with the increased sedimentation due to the removal of the Atlantic rainforest and the discharge of industrial and urban effluents. The effects of the warming of oceanic waters that had previously affected several reef areas with high intensity coral bleaching had not shown, by the time of the 2010 event, any episodes of mass coral mortality on Brazilian reefs

Stable red cell mass despite contracted plasma volume in men with essential hypertension

Red blood cell mass, plasma volume, and renal and systemic hemodynamic measurements were evaluated in 24 normotensive men (group 1), 45 men with mild essential hypertension (group 2), and 43 men with moderate to severe essential hypertension (group 3). Despite significant hemodynamic differences between the groups and although plasma volume was contracted, the increased hematocrit in the third group of patients was not explained by an increase in red blood cell mass. Because this was the case in all groups it demonstrates that the increased hematocrit in patients with more severe essential hypertension is solely attributable to the contracted plasma volume

Immediate hemodynamic effects of a new calcium-channel blocking agent (nitrendipine) in essential hypertension

The immediate hemodynamic effects of a new calcium-channel blocking agent nitrendipine were studied in 12 patients with mild established essential hypertension. According to the response to mean arterial pressure, patients were classified into responders (decrease >10 mm Hg, 7 patients) and nonresponders (≤10 mm Hg, 5 patients). The decrease in arterial pressure in responders was associated with a significant (

Diurnal variation of blood pressure in elderly patients with essential hypertension

Twenty-one elderly patients with essential hypertension, all over 65 years of age, were subjected to automated noninvasive 24-hour blood pressure measurement. Readings were obtained every 7.5 minutes throughout the day. The data were analyzed with respect to: correlation between office and ambulatory pressure measurements; possible differences in the circadian blood pressure pattern; and the existence of hypertensive or atherosclerotic cardiovascular complications. In all patients, the office systolic pressures ere significantly highwer than the ambulatory daytime pressures; diastolic pressures were similar. At night, two patterns of blood pressure emerged. In one there was a further fall in both systolic and diastolic pressures and normotensive levels, whereas the other pattern revealed no change in diastolic pressure, although systolic pressure increased significantly to similar levels as measured in the office. The prevalence of hypertensive or atherosclerotic cardiovascular complications in the patients with the first pattern was significantly less than in the group of patients with the second pattern (chi square,