[Different patterns of abnormalities in exercise 201TI myocardial scintigraphy and their mechanisms].

OBJECTIVE: To categorize the patterns of abnormalities in exercise (201)TI myocardial scintigraphy and explore the mechanisms. METHODS: Exercise (201)TI myocardial scintigraphy was performed in 203 patients with clinically suspected coronary artery disease, including 74 normotensive patients, 78 hypertensive patients without left ventricle hypertrophy (LVH) and 51 hypertensive patients with LVH. All the patients underwent coronary angiography one month before or after (201)TI myocardial scintigraphy, and the patterns of abnormal findings were categorized as segmental, non-segmental and mixed patterns. Patients with abnormal (201)TI myocardial perfusion and normal coronary angiographic findings were followed up. RESULTS: In hypertensive patients without and with LVH, the ratios of abnormal perfusion in segmental, non-segmental and mixed types were 52/60 and 32/58, 4/60 and 9/58, and 4/60 and 17/58, respectively. The ratios of normal coronary angiography in the 3 types were 17/84, 13/13 and 10/21, respectively. Among the 40 patients followed up, 5 with segmental abnormality and 2 with mixed abnormalities developed large coronary artery disease, which was found in none of the patients with segmental abnormality. CONCLUSIONS: In hypertensive patients with and without LVH, segmental perfusion abnormalities may be attributed to the anatomic and functional stenosis of the large coronary arteries, and the non-segmental abnormal perfusion might be only possible with coronary microvascular diseases.

[Association of platelet endothelial cell adhesion molecule-1 gene polymorphism with coronary heart disease].

OBJECTIVE: To investigate the association of Leu125Val and Ser563Asn polymorphism of the gene encoding platelet endothelial cell adhesion molecule-1(PECAM-1) with coronary heart disease. METHODS: This study included 156 patients with the diagnoses of coronary heart disease (CHD) and coronary lesions derived from electrocardiography, myocardial enzyme analysis and coronary angiography as the CHD group, and another 75 in-patients admitted within the same period who showed no signs of CHD in the above examinations constituted the control group. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was employed to examine the missense polymorphism of PECAM-1gene in the position of Leu125Val and Ser563Asn. RESULTS: There were significant differences between CHD and control group in terms of the allele frequencies and genotype distributions of PECAM-1 gene, and the differences were especially conspicuous in the allele frequencies of 125Val and 563Asn (P<0.05) and genotype distributions of 125Val/Val and 563Asn/Asn. CONCLUSION: PECAM-1 gene polymorphism 1 may be a genetic risk factor for coronary heart disease.

[Protective effects of preconditioning phlebotomy against myocardial ischemia-reperfusion injury in rat].

OBJECTIVE: To investigate the protective effect of preconditioning phlebotomy against ischemia-reperfusion injury and the role of calcitonin gene-related peptide (CGRP) in this protection mechanism. METHODS: Sixty SD rats were randomly assigned in equal number into control, phlebotomy, and CGRP polyclonal antibody (PcAb) groups, all of which were subjected to 30 min regional ischemic followed by two-hour reperfusion, initiated 15 min after phlebotomy in the latter 2 groups. The rats in CGRP PcAb group were given the antibody (2.5 mg/kg) before phlebotomy. After the operations, plasma CGRP level was determined in 8 rats from each group by radioimmunoassay, and the infarct size (IS) by nitro blue tetrazolium, represented as percentage of the area at risk (AAR). RESULTS: The mean plasma CGRP level was significantly increased in phlebotomy group compared with the levels in control and PcAb groups (F=12.4, P=0.032-0.005), and a significant reduction in IS (F=52.4, P<0.001) and IS/AAR (F=43.7, P<0.001) occurred in phlebotomy group. CONCLUSION: Preconditioning phlebotomy has obvious cardioprotective effect against ischemia-reperfusion injury, in the mechanism of which CGRP may play a role.

[Association between aldosterone synthase gene polymorphism and hypertrophic cardiomyopathy].

OBJECTIVE: To investigate the relationship between aldosterone synthase (CYP11B2) gene polymorphism and hypertrophic cardiomyopathy (HCM). METHODS: Fifteen HCM patients and 18 healthy subjects were enrolled in this study. Peripheral blood samples were collected from these subjects to exact genome DNA. PCR and Hae III restriction endonuclease digestion were employed to study -344C/T polymorphism of CYP11B2 gene. RESULTS: CYP11B2 gene showed a significant difference in CT genotype distribution in HCM groups as compared with that in the control groups (P<0.05). CONCLUSION: CT genotype of CYP11B2 gene may be one of factors responsible for the pathogenesis of HCM in a proportion of patients.

Thallium-201 myocardial scintigraphy in hypertensive patients with and without left ventricular hypertrophy: a clinical study.

OBJECTIVE: To evaluate the myocardial perfusion in hypertensive patients with and without left ventricular hypertrophy using thallium-201 (201TI) myocardial scintigraphy and explore the mechanism that causes the perfusion abnormalities. METHODS: Thallium-201 myocardial scintigraphy was performed in 85 patients with clinically suspected coronary artery disease to assess the myocardial perfusion status. For patients with myocardial perfusion abnormalities as indicated by the scintigraphy, coronary angiography was ordered within 1 month. RESULTS: The incidence of 201TI myocardial perfusion abnormalities in hypertensive patients with ventricular hypertrophy (85.7%) was significantly higher than that in the normotensive (39.3%, P<0.01) and hypertensive patients not complicated with hypertrophy (61.2%, P<0.05). The semiquantitative score was higher in the hypertensive patients with hypertrophy than in the normotensive (P<0.01) and hypertensive patients without hypertrophy (P<0.05). More hypertensive patients with hypertrophy (9/18) had normal results of coronary angiography than the normotensive (0/13, P=0.044) and hypertensive patients without hypertrophy did (3/19, P<0.05). CONCLUSIONS: A higher rate of 201TI perfusion abnormalities occurs in the hypertensive patients with ventricular hypertrophy, which may be attributed to the pathological changes in the major coronary vessels and to the coronary microvascular diseases as well.

A Method of the Simultaneous Purification of Cardiac Troponin T and I.

A method of the simultaneous purification of cardiac troponin T (cTnT) and troponin I (cTnI) from human cardiac left ventricular muscle have been developed. Five mg cTnT and 10.2 mg of cTnI were obtained from 100 mg of cardiac muscle. The purity of cTnT and cTnI could reach to 97.6% and 97.2% respectively. Their immunoactivity and specificity have been identified by ELISA method.