Mao Huan-yuan

HLA-DRB1 gene polymorphism in patients with dilated cardiomyopathy

SummaryTo probe into the genetic background and immunopathogenesis of dilated cardiomyopathy (DCM), HLA-DRBl gene polymorphism in 68 patients with DCM and 175 normal control subjects were analyzed by using the polymerase chain reaction/sequence specific primer (PCR/SSP) techniques. It was found that the frequencies of HLA-DRBl * 15 and HLA-DRBl * 03 alleles were significantly lower in DCM patients than those in normal controls (14.71% vs 29.71% and 4.41% vs 15.43%, respectively), the relative risks (RR) in the DCM patients being 0.41 and 0.25, respectively, allP>0.05. However, the frequencies of HLA-DRBl 11 and HLA-DRB1* 12 alleles were significantly higher in the DCM patients than in controls (29.4% vs 12.00% and 36. 76% vs 12. 57%, respectively) with the RR in the DCM patients being 3.06 and 4.04, respectively, allP>0. 01. These findings further demonstrated that-immunogenetics might play a predominant pathogenetic role in partial DCM patients.

Echocardiographic study of Marfan’s syndrome

SummaryBased on an echocardiographic study of a series of 52 patients with Marian’s syndrome, we found that the echocardiographic characteristic of Marfan’s syndrome was marked dilatation of aortic root with or without mitral valve prolapse. 48 cases (92.3%) in this series were found to have aortic root enlargement, 11 of which were associated with mitral valve prolapse. This finding suggested that marked dilatation of aortic root should be an important diagnostic picture of Marfan’s syndrome. Echocardiogram enhanced significantly the detection rate of cardiovascular defects, so it is helpful in observation of outstanding family tendency toward involvement of different organ-systems in different families in Marfan’s syndrome.

Possible association of HLA-DRB1 gene with the autoantibody against myocardial mitochondria ADP/ATP carrier in dilated cardiomyopathy.

SummaryTo probe the genetic background and immunopathogenesis of dilated cardiomyopathy (DCM) 77 patients with DCM, HLA-DRB1 gene polymorphism were analyzed by using the polymerase chain reaction/sequence specific primer (PCR/SSP) technique and autoantibody against myocardial mitochondria ADP/ATP carrier were examined by using the Immunoblot analysis. The frequency of HLA-DRB1*0901 allele was significantly higher in DCM patients in which autoantibody against ADP/ATP carrier of myocardial mitochondria is positive in contrast with those in which the autoantibody is negative (25.46% vs 3.45%,P<0.05), the relative risk (RR) being 9.56. The other frequencies of HLA-DRB1 alleles have no significant difference in the antibody positive group and negative group. It is possible that a subset of DCM patients may exist in which autoimmunity is associated with genetic factors.

Effect of dauricine on redistribution of Glycoprotein IV in platelet membrane of patients with mitral stenosis

OBJECTIVE To investigate the effect of dauricine on the irreversible platelet aggregability of patients with mitral stenosis (MS). METHODS Glycoprotein IV (GP IV) and thrombospondin (TSP) levels on the membrane surface of the stationary platelet or platelet activated by thrombin (0.05 U/ml, 0.1 U/ml, 0.5 U/ml, 1.0 U/ml) in 16 patients with MS were measured with flow cytometric method and compared with those of the healthy (14 cases). RESULTS The GP IV level of stationary platelet, the GP IV and TSP levels of activated platelet in MS patients were higher than those in the healthy significantly (P < 0.01), while the TSP level of stationary platelet was not different between the patients and the healthy (P > 0.05). The GP IV redistribution on the activated platelet surface was apparently inhibited by dauricine (50 mumol/L, P < 0.05, P < 0.01) and the release of TSP from intracellular alpha-granules was inhibited by dauricine only in the activated platelets induced by thrombin of low concentration (0.05 U/ml and 0.1 U/ml, P < 0.05, P < 0.01), inhibiting effect was not found in those activated with high concentration of thrombin. CONCLUSION The activity and reactivity to thrombin of platelets increased in MS patients, and dauricine was able to reduce the occurrence of the irreversible platelet aggregation in MS patients.

Clinical observation of haemodynamic effects of rhomotoxin in hypertensive patients

SummaryThe haemodynamic changes of 30 hypertensive patients treated with rhomotoxin were studied with mechanocardiogram. Both PEPI and PEP/LVET were apparently increased in our patients, indicating that the myocardial compliance of the hypertensive patients was reduced and their cardiac function was abnormal to a certain extent. Rhomotoxin reduced the cardiac afterload by lowering the blood pressure (from 192±26/114±14 to 143±25/88±11 mmHg) and slowing the heart rate (from 76±13 to 58±10 beats/min) significantly. Its effects on cardiac phases were mainly to shorten QA2I, LVETI and PEPI and to prolong SFW, while other parameters such as PEP/LVET, A/EO, EF and Vcf were unchanged. Thus, as the blood pressure of the hypertensive patients was lowered to a significant therapeutic level by rhomotoxin, the left ventricular ejection would be enhanced without depressing myocardial contraction and its pump function. Furthermore, the myocardial oxygen consumption was markedly reduced (P < 0.001), thus rhomotoxin would help to improve the cardiac function in hypertensive patients.

Acute toxicity of rhomotoxin in animals

SummaryThe LD50 of rhomotoxin in mice was 0.522 mg/kg i.p. In dogs, its effective antihypertensive dose was 3.5µg/kg i.v. By 6 times the above dose, arrhythmias and changes of T wave occurred in most dogs, however, all these changes would disappear promptly and spontaneously. By 20 times the dose, death occurred in some dogs. By 30 times the dose, ventricular fibrillation occurred which resulted in death of all the animals. Rhomotoxin in effective antihypertensive dose decreased the contractility of the heart muscle slightly and temporarily, but it had no significant effect on respiration. Large dose (35 µg/kg) of rhomotoxin seemed to have no remarkable influence upon the functions of the liver and kidney in rabbits, nor did it do any significant damage to the heart, liver and kidney in pathological studies.

Distribution and excretion of3H-rhomotoxin in mice

SummaryThe distribution and excretion of intravenous injected3H-rhomotoxin was studied in mice. The radioactivity of3H-rhomotoxin was found to be high in gall bladder, liver and kidney, lower in thyroid gland, adrenal gland, heart and lungs, and lowest in brain. 52.4% of the drug was excreted in urine and feces within 6 h. Rhomotoxin was bound to plasma protein (60 % at 30 min) and to some extent to liver and kidney tissue.

Subacute toxicity of rhomotoxin in rabbits.

It has been proved by clinical and pharmacological studies that rhomotoxin has a rapid prominent antihypertensive effect, as well as a negative chronotropic effecttl-BJ. Acute toxici ty test indicated that rhomotoxin does not effect evidently l iver and kidney function in rabbits, nor did it cause any significant damage to the heart , l iver a,:d kidney in pathological studies ETj. The experiments wi th mice, investigating d_istribution and excretion of 3H-rhomotox in , have demonstrated that maintenance time of the drug in the body is short E81. For the purpose of furnishipg clinical practice wi th necessary informat ion, this article aims at detecting if a relatively longterm administrat ion of rhomotoxin will cause any morphological or functional changes in different organs of the rabbits studied.

EPSSb: A new M-mode echocardiographic index for evaluating left ventricular function in patients with myocardial infarction

SummaryM-mode echocardiograms were studied in 40 patients with myocardial infarction. The results we obtained indicate that both EPSSa and EPSSb are very valuable indices for evaluating LV function in patients with myocardial infarction. Accuracy of EPSSb attained in this study is identical with that of EPSSa, and, in addition, the measurement of the former is simpler. Therefore, we recommend to use EPSSb instead of EPSSa in clinical practice

Two-dimensional echocardiographic diagnosis of postinfarction ventricular aneurysms

SummaryA comparative study of two-dimensional echocardiography with ECG was performed in 52 patients with myocardial infarction. Based on Sun’s ECG criteria for diagnosing ventricular aneurysm, the sensitivity of two-dimensional echocardiography (2-DE) to diagnosing ventricular aneurysm was found to be 73% and the specificity, 98 %. This article proposes the following 2-DE criteria for diagnosing ventricular aneurysm: (l) a localized bulge of the ventricular chamber throughout the cardiac cycle, (2) akinesia or paradoxical motion of the bulging ventricular wall. 2-DE can not only define the site of ventricular aneurysm but also furnish information on the size of ventricular aneurysm, the motion situation of the ventricular wall and left ventricular function, etc. Therefore, 2-DE is more valuable for diagnosing ventricular aneurysm than ECG.