AIM: To investigate changes of calcitonin gene-related peptide(CGRP) in myocardial stunning rats. METHODS: Rat in vivo myocardial stunning model was used. CGRP content in plasma and myocardium were determined by radioimmunoassay. RESULTS: Plasma level of CGRP increased significantly ( P

Objective: To prepare monoclonal antibodies (McAb) with cardiac troponin I (cTnI) which was purified from fresh human cardiac muscle within 6 h. Methods: (1) Extraction and purification of human cTnI: cTnI was purified by high salt extraction, saltless precipitation, 65℃ treatment, ammonium sulfate fractionation and DEAE-cellulose chromatography, etc. (2) Preparation of anti human cTnI McAb: The purified cTnI was injected into the spleen of BALB/c mice. The cTnI-primed spleen cells were fused with Sp2/0 myoloma cell. The McAbs anti human cTnI were obtained by screening with indirect ELISA and 3 times clone. (3)The identification of anti cTnI McAb. Results: Five hybridoma cell lines, named 3A7，3A11，3D2，3F10 and 1H9 were developed, which could secret McAb stably. The 5 McAbs all were demonstrated to be IgG2a by double gel diffusion test. The number of hybridoma chromosomes was between 92 to 110 and the chromosomes were mainly telocentric. Five kinds of ascites had no cross-reaction to LDH，CK，CK-MB ，AST and cardiac troponin T(cTnT), and their titers were between 3.2×10-6 to 1.6×10-7. Conclusion: 3D2，3F10 and 3A7,3A11,1H9 react to different epitopes of cTnI.

Objective To evaluate the initial experience of intracoronary stenting in patients with acute myocardial infarction (AMI) in our hospital.Methods Ballon-expansion stents were deployed in 18 patients (male: 15, female 3, aged between 38-72 years old) with AMI after emergency PTCA. The major indications for intracoronary stenting in our present study include: 1) acute reocclusion or high risk of reocclusion due to intimal dissection; 2) severe residual stenosis (≥50% diameter stenosis) after repeat balloon dilation; and 3) obvious elastic recoil failed to response to repeat intracoronary nitroglycerin infusion. The dilating pressure for stent implantation was 12-18 atm with a dilating time of 10-30 sec. Patients were heparized during catheter maneuvers and were medicated with Ticlopidine (250 mg, twice daily) for 3 months and aspirin (250 mg, once daily) after stenting.Results 1) Coronary angiography (CAG) showed that all patients (n=18) had a single-vessel total occlusion (left anterior decending 9, right coronary artery 8, and left circuflex 1) before emergency PTCA and was successfully restored to TIMI 3 grade blood flow after intracoronary stenting (13 with Nir stent, 1 with Jonson and Jonson stent, and 4 with Cordis stent). 2) Minor residual intracoronary thrombosis was presented in 5 of 18 patients after PTCA, and it was totally disppeared after stenting; 3) One patient with inferior infarction developed Ⅲ degree atrioventricular blockade (AVB) and temporary pacemaker was introduced. This patient died of cardiac tamponade 6 h after stenting due to right ventricular perforation by electrode. No cardiac death, recurrent angina and reinfarction occurred during the 4-16 months follow-up peroid in the other 17 patients; 4) No angiographically restenois was found in all the 3 patients who had a secondary conronary angiography 4 weeks after stenting. 5) Left ventricular ejection fraction (LVEF) determined with Doppler echocardiography 4 weeks after stenting tended to be improved but failed to reach significant difference as compared to the basal LVEF (43.27%±8.43% vs 40.58%±7.23%, P>0.05, n=17) measured within 24 h after the onset of chest pain.Conclusions These results suggest that intracoronary stenting is a highly effective strategy in prevention or treatment of acute reocclusion after emergency PTCA in AMI. Minor residual intracoronary thrombosis after balloon dilation was not a contraindication for stent implantation.

Pulsatile blood flow plays an important role in maintaining normal vascular endothelial function. Quantitative measurement of pulsatility of artery blood pressure and blood flow in dogs and effects of enhanced external counterpulsation (EECP) on the pulsatility were taken in this study. Common carotid artery blood pressure and blood flow were measured in 6 beagle dogs that had suffered from an acute myocardial infarction 6 weeks before. A 6F tip transducer catheter was inserted into the right common carotid artery to measure blood pressure, and blood flow was measured in the left common carotid artery by an electromagnetic blood flow probe under anesthesia before and during EECP. Blood pulse pressure, pulsatility index (ratio of peak pressure to end diastolic pressure) and standard deviation of blood pressure were calculated to evaluate the pulsatility of arterial blood pressure. Blood pulse flow, pulsatility index (ratio of peak flow to trough flow) and standard deviation of blood flow were calculated to evaluate the pulsatility of blood flow. Mean vascular resistance (MVR) was calculated as MVR = mean blood pressure/mean blood flow. Blood pulse pressure, pulsatility index and standard deviation of blood pressure were elevated from 30 +/- 9 mmHg, 1.26 +/- 0.05 and 8.7 +/- 2.5 mmHg to 43 +/- 8 mmHg (P < 0.05), 1.54 +/- 0.13 and 12.4 +/- 2.0 mmHg (P < 0.05) before and during EECP, respectively. Blood pulse flow, pulsatility index and standard deviation of blood flow were elevated from 317 +/- 48 ml/min, 2.85 +/- 0.21 and 96 +/- 21 ml/min to 447 +/- 88 ml/min, 4.56 +/- 0.90 and 131 +/- 39 ml/min before and during EECP (P < 0.05). MVR was decreased from 578 +/- 72 before EECP to 476 +/- 85 Wood units during EECP(P < 0.05). These data demonstrate that EECP gives an elevation of pulsatility to blood pressure and blood flow, thus it may lead to the decrease of vascular resistance.
Animals ; Blood Pressure ; Carotid Arteries ; physiology ; Counterpulsation ; Dogs ; Hemodynamics ; Pulsatile Flow ; Regional Blood Flow ; Vascular Resistance

Pulsatile blood flow plays an important role in maintaining normal vascular endothelial function. Quantitative measurement of pulsatility of human arterial blood pressure and the influence of enhanced external counterpulsation (EECP) on the pulsatility were investigated in this study. Eight healthy young male volunteers aged 22 to 35 were included. A 4F tip transducer catheter was inserted under local anaesthesia into the radial artery up to the aortic arch. Intraarterial blood pressure was recorded before and during EECP. Blood pulse pressure, pulsatility index (ratio of peak pressure to end diastolic pressure) and standard deviation of blood pressure in 5 cardiac cycle was calculated to evaluate the pulsatility of arterial blood pressure. The results showed that blood pulse pressure, pulsatility index and standard deviation of blood pressure were elevated from 47 +/- 5 mmHg, 1.64 +/- 0.11 and 13.6 +/- 1.5 mmHg to 77 +/- 3 mmHg, 2.46 +/- 0.25 and 19.3 +/- 2.2 mmHg before and during EECP respectively (P < 0.05). Decreasing of systolic pressure and increasing of diastolic pressure during counterpulsation were also observed. EECP gives an elevation of pulsatility to human blood pressure.
Adult ; Blood Pressure ; physiology ; Blood Pressure Determination ; Counterpulsation ; Humans ; Male ; Pulsatile Flow

In the early 1990's, emergency percutaneous transluminal coronary angioplasty (PTCA) has been proven to be the best strategy for acute myocardial infarction (AMI). It has not only resulted in a higher vascular recanalization, but has also further reduced mortality and morbidity, and has greatly improved life quality of patients with AMI.Objective To investigate the effect of emergency PTCA in AMI.Methods Emergency PTCA was performed in 52 AMI patients (male: 43, female: 9) from October 1993 to December 1997 in our hospital. The patients were aged between 31-89 years (±s, 53.7±8.2). Among them, 25 had anterior infarction, 27 inferior infarction. Angiographically infarct-related vessels were left anterior descending artery (LAD) in 27 cases, right coronary artery (RCA) in 22, and left circumflex artery (LCx) in 3. The mean time from the onset of chest pain was 6.12±5.13 h (2-12 h). Primary PTCA (balloon angioplasty without previous thrombolytic therapy) was performed in 34 cases, and rescue PTCA (balloon angioplasty after previous thrombolytic therapy that had failed to restore blood flow) in 15 cases, and immediate PTCA ( balloon angioplasty after previous successful thrombolysis but with severe residual stenosis and reoccurring angina pectoris) in 3 cases. Only the infarct-related vessels was dilated during emergency PTCA which is similarto conventional balloon angioplasty. All patients were given aspirin of 250 mg/d and were heparinized during the first 3-5 days after PTCA. Ticlopidine (250 mg, twice daily) was also given for 3 months if patients had experienced intracoronary stenting.Results Emergency PTCA was successfully performed in 48 of 52 patients (33/34 in primary PTCA, 12/15 in rescue PTCA, and 3/3 in immediate PTCA) which accounts for the initial success rate of 92%. Intracoronary stents were implanted in 18 of the 48 patients due to the presence of different vessel complications. PTCA was failed in 4 patients (3 occurred in rescue PTCA, 1 occurred in primary PTCA). Among the patients, one died of acute pulmonary edema during the rescue PTCA procedure, one had acute reocclusion after rescue PTCA and died of acute pump failure within 24 h. Guiding wire failed to put through lesions in the other 2 patients. Mass intracoronary thrombosis was present in 5 of 34 patients after primary PTCA despite the restoration of TIMI 3 grade blood flow in the distal segment. The residual thrombosis disappeared after urokinase (500 000-1 500 000 IU) was infused into the culprit coronary.Conclusions Clinical studies have suggested that emergency PTCA is more effective in early reperfusion than that of thrombolysis in AMI. Though emergency PTCA is highly effective, but the initial success rate is lower than that of conventional PTCA with a higher complication and mortality. Thus it should be only steadily introduced into AMI.