Objective To explore the value of the diagnosis of middle cerebral artery (MCA) stenosis with transcranial Doppler ultrasound (TCD). Methods The clinical data in patients with ischemic cerebrovascular disease examined with digital subtract angiography (DSA)and TCD were analyzed retrospectively. DSA was used as a gold standard to analyze the sensitivity and specificity of the diagnosis of MCA stenosis with TCD. The normal and TCD blood flow velocity with different degrees of stenosis were compared. The best cut-off point of the TCD blood flow velocity of MCA at different degree of stenosis was calculated. Results DSA confirmed that 103 patients had MCA stenosis or occlusion, in which 12 were mild stenosis, 22 were moderate stenosis, 40 were severe stenosis, and 39 were occlusion. Compared to DSA, the sensitivity of TCD in detection of moderate and severe MCA stenosis or occlusion was 78. 8%, the specificity was 96. 0%, and the accuracy was 93. 0%, the missed diagnosis rate was 21. 2%, and the misdiagnosis rate was 4. 0%. As to the blood flow velocity, there was no significant difference between the mild stenosis and normal groups; while there was significant difference between the moderate stenosis and normal groups (P ＜0. 001). In addition, there was no significant difference in blood flow velocity between the moderate stenosis and severe stenosis groups. Determining the cut-off value of the best peak systolic velocity of the moderate stenosis was 163. 5 cm/s, while the best cut-off value of the mean velocity was 108. 5 cm/s. Conclusions TCD has certain advantages in the diagnosis of the MCA stenosis or occlusion, and it can be used as a safe and inexpensive screening means before DSA examination.

Objective To establish the rabbit brain death model,and observe the change of kidney function and morphology in the brain death rabbits,fully evaluate the possibility of transplantation surgery carried out with brain death donor kidney.Method 40 male healthy New Zealand rabbits were randomly divided into sham group (n =20) and brain death group (n =20),and each group further was divided into four groups according to 2,4,6 and 8 h after brain death groups.At the end of the experiment,the blood samples and kidney tissues were collected.The level of blood urea nitrogen(BUN),serum creatinine (Cr) and the apoptosis of kidney cells were determined by automatic biochemistry analyzer and TUNEL method,respectively.The morphology changes of liver were detected by HE staining.Result Although BUN values were with no obviously alteration (P＞0.05) within 8 h after brain death,the renal Cr levels in the states of 2,4 and 8 h (P＜0.05) brain death were found significantly increased compared with shamed groups.The denaturalization in the epithelial cells of renal tubule,glomerulus atrophygradually,swelling and vacuolation of epithelial cells,edema in the interstitium and inflammatory cell infiltration and partly occlusion in proximal convoluted tubule gradually emerged in the brain dead groups.The inflammatory factor intercellular adhesion molecule (ICMA) and the apoptosis index in brain dead groups increased in a time dependent manner but the expressions of protective factor HSP70 conducted a contrary tendency.Conclusin Brain death could lead to the damage of kidney function and morphology and this injury aggravated in a time dependent manner.The alterations might be relevant to the production of inflammatory factors.Within 8 h after brain death there were obvious changes in the kidney function and morphology,which provide experimental basis for the rational use of brain death donor kidney transplantation.