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ObjectiveTo explore the change of renal cortical perfusion in rabbits by microbubbles-enhanced ultrasound cavitation.MethodsTotally 20 New Zealand rabbits were randomly divided into four groups, 5 rabbits in each group. SonoVue was injected via the ear vein at a dose of 0.1 ml/kg. The renal perfusion imaging 30 s modeling was made. Under the mode of contrast enhancement, the rabbit kidneys irradiated with different mechanical indexs (MI) were 0.6 (MI 0.6 group) , 0.75 (MI 0.75 group) , 1.1 (MI 1.1 group) and 1.3 (MI 1.3 group) for 60 s, 15 min respectively. After the irradiation and conventional ultrasound contrast was made again, the renal perfusion imaging was mad. The time-intensity curves (TIC) were analyzed obtained from the following parameters: the slope rate of ascending curve (A) , the slope rate of descending curve (α) , area under the curve (AUC) , time to peak (TTP) , and derived peak intensity (DPI) . One-way ANOVA and LSD-t were used to analyze all experimental data.ResultsCompared with the MI 0.6 group, the MI 1.1 group and the MI1.3 group, the A, α were less than MI 0.6 group, the AUC, DPI, TTP were greater than MI 0.6 group, and the differences were statistically signiifcant (MI 1.1 groupvs MI 0.6 group:t=3.13, 5.31, 4.25, 4.53, 5.72, allP<0.05; MI 1.3 groupvs MI 0.6 group:t=3.67, 6.23, 4.47, 5.48, 6.86, allP<0.05). Compared with the MI 0.75 group, the MI 1.1 group and the MI 1.3 group, the α were less than MI 0.75 group, the AUC, DPI, TTP were greater than MI 0.75 group, and the differences were statistically signiifcant (MI 1.1 groupvs MI 0.75 group:t=6.02, 4.36, 4.85, 5.83, allP<0.05; MI 1.3 groupvs MI 0.75 group:t=6.19, 4.51, 5.73, 6.97, allP<0.05); the MI 1.1 group and the MI 1.3 group, the A were less than MI 0.75 group, and the difference were not statistically signiifcant. The MI 1.1 group and the MI 1.3 group, the MI 0.6 and the MI 0.75 group, and the difference were not statistically signiifcant.ConclusionsTo the change of hemodynamic of the rabbits renal cortical perfusion in the microbubbles-enhanced ultrasound cavitation contrast agent can be observed. Along with the mechanical index increased renal cortical perfusion flow stasis and the perfusion on of slowed in rabbit, may cause renal damage, the TIC curve displayed further changes.
RESUMO
Objective To reproduce an experimental model of blast injury to dog brain simulating the mechanism of primary effect of the blast wave of explosive weapons.Methods A spherical explosive with explosive energy of 1gTNT was used to detonate at different distances(9mm,13mm)from the right temple to produce blast injury to the dog brain.The changes in physiological index before or after detonating and the surviving time after injury were recorded.The changes in the behavior of the wounded animals and characteristics of pathological changes in the brain were observed.Results Respiratory arrest,hypotension,and decreased heart rate were observed after wounding.All animals survived longer than 6 hours after the explosion injury.Obvious subdural hematoma and sub-arachnoid hemorrhage occurred frequently.Traumatic conditions of the brain were different in the two groups.Conclusions The animal model reproduced in this experiment simulates that produced by blast wave of explosive weapons.It is reproducible,easy to handle,and can be used in experimental study of blast injury to the brain.