Morphological and hematological studies of Trypanosoma spp. infecting ornamental armored catfish from Guamá River-PA, Brazil

A total of 281 specimens of freshwater armored ornamental fish species (Leporacanthicus galaxias, Lasiancistrus saetiger, Cochliodon sp., Hypostomus sp., Pseudacanthicus spinosus, Ancistrus sp. and Rineloricaria cf. lanceolata) were captured at the hydrological basin of Guamá River, Pará, Brazil. The infection by Trypanosoma spp. was inspected. The morphological and morphometric characterization of the parasites and the hematological parameters were determined. Leporacanthicus galaxias and Pseudacanthicus spinosus presented 100% infection prevalence, and the other species showed a variable prevalence of infection. The parasites showed clearly different morphotypes and dimensions, and probably belong to different species. The hematological response to the infection varied with the host. Cochliodon sp. showed no differences between infected and not infected fish. In other species several modifications on some hematological parameters were found, but apparently without causing disease. It is emphasized the possibility of introduction of the parasites in new environments due to the artificial movements of these ornamental fish

The novel organic mononitrate NDHP attenuates hypertension and endothelial dysfunction in hypertensive rats

Rationale: Development and progression of cardiovascular diseases, including hypertension, are often associated with impaired nitric oxide synthase (NOS) function and nitric oxide (NO) deficiency. Current treatment strategies to restore NO bioavailability with organic nitrates are hampered by undesirable side effects and development of tolerance. In this study, we evaluated NO release capability and cardiovascular effects of the newly synthesized organic nitrate 1, 3-bis (hexyloxy) propan-2-yl nitrate (NDHP). Methods: A combination of in vitro and in vivo approaches was utilized to assess acute effects of NDHP on NO release, vascular reactivity and blood pressure. The therapeutic value of chronic NDHP treatment was assessed in an experimental model of angiotensin II-induced hypertension in combination with NOS inhibition. Results: NDHP mediates NO formation in both cell-free system and small resistance arteries, a process which is catalyzed by xanthine oxidoreductase. NDHP-induced vasorelaxation is endothelium independent and mediated by NO release and modulation of potassium channels. Reduction of blood pressure following acute intravenous infusion of NDHP was more pronounced in hypertensive rats (two-kidney-one-clip model) than in normotensive sham-operated rats. Toxicological tests did not reveal any harmful effects following treatment with high doses of NDHP. Finally, chronic treatment with NDHP significantly attenuated the development of hypertension and endothelial dysfunction in rats with chronic NOS inhibition and angiotensin II infusion. Conclusion: Acute treatment with the novel organic nitrate NDHP increases NO formation, which is associated with vasorelaxation and a significant reduction of blood pressure in hypertensive animals. Chronic NDHP treatment attenuates the progression of hypertension and endothelial dysfunction, suggesting a potential for therapeutic applications in cardiovascular disease

The Brazilian Global Atmospheric Model (BAM): Performance for Tropical Rainfall Forecasting and Sensitivity to Convective Scheme and Horizontal Resolution

Abstract This article describes the main features of the Brazilian Global Atmospheric Model (BAM), analyses of its performance for tropical rainfall forecasting, and its sensitivity to convective scheme and horizontal resolution. BAM is the new global atmospheric model of the Center for Weather Forecasting and Climate Research [Centro de Previsão de Tempo e Estudos Climáticos (CPTEC)], which includes a new dynamical core and state-of-the-art parameterization schemes. BAM’s dynamical core incorporates a monotonic two-time-level semi-Lagrangian scheme, which is carried out completely on the model grid for the tridimensional transport of moisture, microphysical prognostic variables, and tracers. The performance of the quantitative precipitation forecasts (QPFs) from two convective schemes, the Grell–Dévényi (GD) scheme and its modified version (GDM), and two different horizontal resolutions are evaluated against the daily TRMM Multisatellite Precipitation Analysis over different tropical regions. Three main results are 1) the QPF skill was improved substantially with GDM in comparison to GD; 2) the increase in the horizontal resolution without any ad hoc tuning improves the variance of precipitation over continents with complex orography, such as Africa and South America, whereas over oceans there are no significant differences; and 3) the systematic errors (dry or wet biases) remain virtually unchanged for 5-day forecasts. Despite improvements in the tropical precipitation forecasts, especially over southeastern Brazil, dry biases over the Amazon and La Plata remain in BAM. Improving the precipitation forecasts over these regions remains a challenge for the future development of the model to be used not only for numerical weather prediction over South America but also for global climate simulations