Transthoracic Doppler echocardiography (TTDE) allows noninvasive flow measurement in the distal left anterior descending artery (LAD). The feasibility of detecting coronary flow by contrast-enhanced TTDE with second harmonic technique was assessed, the coronary flow velocity reserve (CFVR) was evaluated in comparison to intracoronary Doppler flow (ICD) analysis and the CFVR after PTCA in LAD was investigated. In 77 (96%) of 80 patients, CFVR was successfully determined with intravenous adenosine infusion. Doppler signal quality was evaluated in the first 46 patients by use of intravenous Levovist infusion and second harmonic technique. The Doppler flow was not visible in 1 patient only. CFVR determined from TTDE (2.77±0.65) was correlated closely with those from ICD (2.88±0.78) measurements (y=0.73x+0.67,r=0.87,P<0.001). In conclusion, TTDE is a feasible method and provides reliable data on CFVR which can be used for followup after PTCA.
To explore the relationship between β-amyloid (Aβ) and the pathogenesis of Alzheimer disease (AD), after injection of β-amyloid into the rat brain, the apoptosis of nerve cells and acetylcholine (Ach) content in rat hippocampus were examined by employing TUNEL technique and base hydroxylamine colorimetry respectively. The influence of age and glucocorticoid on the neurotoxic effect of Aβ was also analyzed. Aβ peptide could strongly induce the apoptosis of neurons in hippocampus, cortex and striate body (P<0.05 orP<0.01). In addition, the senility and glucocorticoid pre-treatment could enhance the toxic effect of Aβ(P<0.05 orP<0.01). It is concluded that Aβ may play an important role in the pathogenesis of Alzheimer disease via its induction of apoptosis of neurons and by decreasing the content of the Ach.