Histological changes of vascular clipping in Wistar rats.

Background: During aneurysm microsurgery, the aneurysmal sac is excluded from circulation by placing one or more clips at the base of the aneurysm. In some cases of complex aneurysms or subarachnoid hemorrhage history, transient clipping before definitive clipping is necessary. The closing force of the transient clip is less than the permanent clip; however, it is sufficient to stop circulation to the aneurysmal sac. The aim of the following work is to analyze and describe histological changes caused by transient and permanent clipping of the abdominal aorta in Wistar-type rats, to study the correlation between the closing force of the clip and the time, it remains on the vascular tissue structures. Methods: Six groups were formed, with 10 rats each, whereby temporary clipping of the abdominal aorta was performed with subsequent sampling of the site where the vascular clip was placed. The groups were: control and temporary clipping with: 2, 5, 10, and 15 and permanent clipping with 5 min. Results: Resection samples of the 3 µm thick aorta were obtained through the routine histological technique and special histochemical techniques (Masson's Trichrome and orcein) from the six groups. Transmural changes were found from Group II-VI. Conclusion: There is a vascular histological effect after both transient and permanent clipping. The sum of time and strength of the clip induce vascular changes visible at 5 min.

Oxidative stress markers and thrombomodulin plasma levels in women with early and late severe preeclampsia.

BACKGROUND: Preeclampsia (PE) is a pregnancy disease associated with oxidative stress and endothelial dysfunction. It can be classified according to the severity and onset-time of clinical symptoms (early PE:<34 weeks, late PE:≥34 weeks). METHODS: We evaluated markers of oxidative stress (thiobarbituric acid reactive substances-TBARs and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)-MTT) and endothelial lesion (thrombomodulin-TM) in early (N = 24) and late severe PE(N = 22) and normotensive pregnant women(N = 26). RESULTS: MTT levels were higher in early sPE than in normotensive pregnancy (P = 0.03). No difference was found comparing late sPE versus normotensive pregnancy, and early sPE versus late sPE. TM levels were higher in early sPE comparing to late sPE women (P = 0.05), but no difference was found between early or late sPE versus normotensive groups. TBARs levels did not differ significantly among the three groups. These data suggest that endothelial lesion and the antioxidant status are more pronounced in early sPE. Moreover, lipid peroxidation might be an early event in PE, stimulating a compensatory antioxidant defense later in pregnancy. CONCLUSIONS: Longitudinal studies involving pregnant women with risk factors for PE development and including other methods for oxidative stress and endothelial lesion determination should be conducted in order to better evaluate the role of these processes in PE pathogenesis.

De la miocardiopatía chagásica a la miocardiopatía isquémica no aterosclerótica. Lesión endotelial: alteraciones de la microcirculación en la enfermedad de Chagas-Mazza / Da cardiomiopatia chagásica à cardiomiopatia isquêmica não aterosclerótica. Lesão endotelial: alterações da microcirculação na doença de Chagas-Mazza / From chagasic cardiomyopathy to non-atherosclerotic ischemic cardiomyopathy. Endothelial injury: alterations of the microcirculation in the disease of Chagas-Mazza

Diversos trabajos demostrarían que los pacientes con patología chagásica crónica presentan anormalidades en la vasomoción coronaria microvascular y epicárdica por disfunción del endotelio vascular. Provocada la alteración endotelial, aumentarían la reactividad plaquetaria y la interacción plaqueta-célula endotelial, produciéndose modificaciones en las proteínas estructurales, disturbios bioquímicos en la transducción de señales con cambios en la proliferación y función celular y respuestas inflamatorias. Una vez establecida la lesión en la microcirculación, la isquemia produciría miocitolisis, reemplazando el tejido cardíaco por fibrosis. La importancia clínica de estos hallazgos radicaría en relacionarlos con los síntomas de angina referidos por los pacientes y en su contribución hacia el avance a la miocardiopatía chagásica crónica, de los pacientes que posean esta anormalidad de la vasomoción en el período crónico sin patología demostrada.

Several studies would show that patients with chronic chagasic pathology have abnormalities in microvascular and epicardial coronary vasomotion due to vascular endothelial dysfunction. Once the endothelial alteration is provoked, the platelet reactivity and endothelial-platelet-cell interaction would increase, resulting in modifications in structural proteins, biochemical disturbances in signal transduction with changes in cell proliferation and function, and inflammatory responses. Once the lesion in the microcirculation was established, ischemia would produce myocytolysis, replacing the cardiac tissue with fibrosis. The clinical importance of these findings is the relationship with the symptoms of angina reported by patients and their contribution to the progression to chronic chagasic cardiomyopathy of patients who have this abnormality of vasomotion in the chronic period without demonstrated pathology.

Vários estudos mostrariam que os pacientes com patologia chagásica crônica têm anormalidades na vasomoção coronariana microvascular e epicárdica devido à disfunção endotelial vascular. Uma vez que a alteração endotelialé provocada, a reatividade plaquetária e a interação endotelial plaqueta-célula aumentariam, resultando em modificações nas proteínas estruturais, distúrbios bioquímicos na transdução de sinal com alterações na proliferação e função celular e respostas inflamatórias. Uma vez que a lesão na microcirculação foi estabelecida, a isquemia produziria miocitólise, substituindo o tecido cardíaco por fibrose. A importância clínica desses achados é sua relação com os sintomas de angina relatados pelos pacientes e sua contribuição para a progressão da cardiomiopatia chagásica crônica de pacientes que apresentam esta anormalidade na vasomoção no período crônico sem patologia demonstrada.