ABSTRACT
ve To compare the effects of coronary-artery-bypass (CAB) surgery with and without cardiopulmonary bypass(CPB) on hemodynamics and the function of the grafts. Methods Thirty-five patients undergoing elective CAB surgery were studied. CAB was performed either with hypothermic CPB (n = 15) or without CPB(off-pump, n = 20) . The patients were premedicated with intramuscular pethidine 50 mg and scopolamine O.3mg. Anesthesia was induced with intravenous midazolam 5-15mg, fentanyl 5-20?g?kg and pancuronium 0.1 mg?kg-1 or pipecuronium 0.1 mg?kg-1 and maintained with iv infusion of fentanyl 6-10?g?kg-1, propofol 2-4mg?kg-1?h-1 and intermittent boluses of pancuronium, midazolam supplemented with 1%-1.5% isoflurane inhalation. In off-pump group naso-pharyngeal T?was maintained at 37.2℃ during operation. The amount of heparin used was equal to about one-third of amount used during CPB and ACT was maintained above 250 seconds. MAP was maintained at 70-90 mm Hg. While blood vessel was being grafted onto the coronary arteries heart rate was maintained at 60-80 bpm, otherwise esmolol 10-20mg was given iv every 5 min until it was satisfactorily controlled. In CPB group, during CPB naso-pharyngeal T?was maintained at 32℃-34℃, MAP at 50-70 mm Hg and blood gases and electrolytes within normal range. Right radial artery was cannulated and 7.5F Swan-Ganz catheter was inserted via internal jugular vein into pulmonary artery for hemodynamic monitoring and blood gas analysis. ECG, SpO2 were continuously monitored during operation. At the end of operation in patients with internal mammary artery used as graft, the flow rate of grafts was measured with 3mm Doppler probe.Results (1) After CAB cardiac index (CT) increased significantly in off-pump group(P0.05) . (3) There was no significant difference in the blood flow of artery graft and myocardial oxygen delivery (MDO2), and consumption ( MVO2) as well as MDO2/MVO2 between the two groups. Conclusions Off-pump CAB surgery has less effects on hemodynamics but systemic and myocardial oxygen delivery and consumption are similar between the two groups.
ABSTRACT
Cells of BT_(325), a human glioblastoma cell line, were treated with 0.5% Triton X-100 and immunostained with a monoclonal antibody to vimentin and antiserum to glial fibrillary acidic protein (GFAP), and followed by fluorescence labeled secondary antibody. After observation with fluorescence microscope the cells were dehydrated in increasing grades of ethanol and then critical point-dried. The carbon-platinum coating replicas of cytoskeleton were observed by transmission electron microscopy. The morphology of whole cytoskeleton as well as the arrangement of microtubules, microfilaments and intermediate filaments were clearly observed by this technique. It was observed that the diameter of intermediate filaments highly increased in the cells stained with the monoclonal antibody to vimentin. In the samples stained with anti-GFAP intermediate filaments were decorated in some cells but undecorated in other cells. The results indicates that all BT_(325) cells express vimentin, but only a fraction of the cells express GFAP. It was also observed that if the cells were fixed with formaldehyde before immunostaing with the monoclonal antibody to vimentin, the diameter of the intermediate filaments only slightly increased. However, the diameter of the intermediate filaments highly increaed in the cells stained firstly with the monoclonal antibody to vimentin and followed by formaldehyde fixation. This result is in accord with that of our previous immunofluorescence study. It indicates that formaldehyde fixation may "mask" certain epitopes on vimentin molecules.