We studied with morphological tools the effects of different doses of Losartan upon the cardiovascular remodeling in nitric oxide deficient rats. At 15 weeks of age, thirty Wistar rats were separated in six groups: control (C), L-NAME (LN), and four groups were LN was given plus Losartan at different doses (1, 5, 20 and 40 mg/kg/day). The L-NAME was given for 9 weeks, the Losartan administration starting on the 2nd week of experiment. We studied the heart, thoracic aorta and superior mesenteric artery with light microscopy and stereology. The blood pressure (BP) increased since the first week of L-NAME administration, the Losartan treatment at doses of 20 and 40 mg/kg/day was efficient to reduce BP after the 7th week of treatment. The cardiac adverse remodeling in the LN group was characterized by intense interstitial fibrosis, impairment of the myocardial microvascularization, cardiomyocyte hypertrophy and consequent loss of cardiomyocytes. The aortic wall structure (density per area of smooth muscle cell nuclei and surface density of lamellae), and the superior mesenteric artery media/lumen ratio were also strongly affected by L-NAME administration. Only in the dose equal or higher than 20 mg/kg/day Losartan showed beneficial effects treating these alterations. In conclusion, both the heart and the arterial wall of NO deficient rats suffer a marked adverse remodeling process that is efficiently treated by a dose-dependent Losartan administration. The efficiency of Losartan treatment in this model of NO synthesis blockade correlates with the hypotensor effect of the drug mainly in the high dose treatment

Se estudiaron con herramientas morfológicas, los efectos de diferentes dosis de Losartan sobre el remodelamiento cardiovascular, en ratas deficientes en óxido nítrico. 30 ratas Wistar, con 15 semanas de edad, fueron separadas en 6 grupos. control (C), L-NAME (LN), y 4 grupos en que administró LN junto con Losartan, en diferentes dosis (1, 5, 20 y 40 mg/kg/dia). El L-NAME fue administrado durante 9 semanas y la administración de Losartan se inició en la segunda semana de experimentación. Se estudiaron el corazón, la parte torácica de la aorta y la arteria mesentérica craneal, con microscopía de luz y estereología. La presión arterial (PA) aumentó desde la primera semana de administración de L-NAME. El tratamiento con Losartan, en las dosis de 20 y 40 mg/kg/día, fue eficiente para reducir la PA después de la séptima semana de tratamiento. El remodelamiento cardiaco adverso en el grupo LN se caracterizó por intensa fibrosis intersticial, disminución de la microvascularización miocárdica e hipertrofia y consecuente pérdida de cardiomiocitos. La estructura de la pared de la aorta (densidad por área de núcleos de células musculares lisas y densidad de superficie de lamelas), y la relación media/luz de la arteria mesentérica craneal, también fueron muy alteradas por la administración de L-NAME. Sólo en una dosis igual o mayor que 20 mg/kg/día, el Losartan tuvo efecto benéfico tratando estas alteraciones. En conclusión, tanto el corazón como la pared arterial de ratas deficientes en óxido nítrico, presentan un proceso de remodelamiento acentuado, y éste es eficientemente tratado con Losartan en diferentes dosis. La eficiencia del tratamiento con Losartan en el modelo de bloqueo de la síntesis de óxido nítrico se correlaciona con el efecto hipotensor de la droga, principalmente en las dosis más elevadas

Avaliar diferentes métodos radiológicos no diagnóstico de corpos estranhos (CEs) de madeira. MÉTODOS: Foram utilizados 11 frangos adultos. Realizou-se lesão perfurante, em cada sobrecoxa do animal. Em um dos lados, foi introduzida e deixada uma farpa de madeira e, na sobrecoxa contralateral, esse mesmo objeto foi introduzido e retirado (Grupo Controle). Após sete dias, os animais foram mortos e tiveram seus membros retirados para avaliação por radiografia simples (RS), ultra-sonografia (US), tomografia computadorizada (TC) e ressonância magnética (RM). Cada exame foi avaliado, independentemente, por dois radiologistas experientes. RESULTADOS: A sensibilidade foi 13,6% para RS, 63,3% para US, 59,1% para RM e 72,7% para TC, com especificidades de 100%, 100%, 95,5% e 95,5%, respectivamente. O valor preditivo positivo foi de 100% para RS e US, de 95% para TC e de 93,8% para RM, enquanto o valor preditivo negativo foi de 53,7%, 73,7%, 78,3% e 70,1%, respectivamente. A acurácia foi de 84,1%, para TC, de 81,8% para US, de 77,3% para RM e de 56,8% para RS. Comprovou-se, histologicamente, presença de reação inflamatória em todas as sobrecoxas que continham CE. CONCLUSÃO: RS apresenta pequena utilidade na detecção radiológica de CE de madeira em frango, devendo-se optar pelo emprego de US e TC, seguido por RM.

PURPOSE: To determine the usefulness of different radiological methods in the diagnoses of wooden foreign bodies (FB). METHODS: Eleven adult chickens were used. Each thigh received a puncture wound and in one of them a wooden splinter was introduced and left in place while in the contralateral it was introduced and removed (control group). After 7 days the animals where killed and the legs removed to be analyzed with conventional radiography (CR), ultrasonography (US), magnetic resonance and computed tomography. The results were viewed by 2 independent senior radiologists. RESULTS: Sensitivity was: CR - 13.6%; US - 63.6%; MR - 59.1%; and CT - 72.7%, with specificity of 100%, 100%, 95.5%, and 95.5%, respectively. The positive predictive value for CR and US was 100%, 95% for CT 95% and 93.8% for MR. CT had a negative predictive value of 78.3%, while US, MR, and CR had 73.7%, 70.1%, and 53.7%, respectively. The accuracy for CT was 84.1%, followed by US - 81.8%, RM - 77.3%, and CR - 56.8%. Inflammatory reaction was histologically demonstrated in all thighs containing FB. CONCLUSION: CR showed a poor performance to detect wooden FB in chickens, while US and CT seem to be the best option, followed by RM.