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Biomedical subjects

X S Cheng

Publications and source records attributed to X S Cheng.

At least 19 recordsLinked to original sources
PubMed1999

Role of superoxide anion in the pathogenesis of cytokine-induced myocardial dysfunction in dogs in vivo.

OBJECTIVE: Although studies in vitro have implicated oxygen-derived free radicals as possible mediators of inflammatory cytokine-induced cell injury, the role of the radicals in the cytokine-induced myocardial dysfunction in vivo remains unclear. The present study was designed to address this point in our novel canine model of cytokine-induced myocardial dysfunction in vivo. METHODS: Studies were performed in mongrel dogs, in which microspheres (MS, 15 microns in diameter) with and without interleukin-1 beta (IL-1 beta) were injected into the left main coronary artery (control and IL-1 beta group). Left ventricular ejection fraction (LVEF) was evaluated by echocardiography for 1 week. RESULTS: Immediately after the intracoronary injection of MS (10(6)/kg), LVEF equally decreased to approximately 30% in both the control and IL-1 beta group. While LVEF rapidly recovered within 2 days in the control group, it remained depressed in the IL-1 beta group until day 7 (p < 0.0001 vs. control group). Pretreatment with OPC-6535 (an inhibitor of superoxide production) before (2 mg/kg i.v.) and 1 and 2 days after IL-1 beta MS application (1 mg/kg i.v.) prevented the IL-1 beta-induced myocardial dysfunction. Superoxide production in the myocardium was significantly higher in the IL-1 beta group than in the control group at day 2 (p < 0.01), and OPC-6535 significantly suppressed the IL-1 beta-induced superoxide production (p < 0.01). An HPLC assay showed that nitrotyrosine, a marker of the formation of peroxynitrite by superoxide anion and nitric oxide, was present in the myocardium treated with IL-1 beta but not in that with control MS. OPC-6535 abolished the IL-1 beta-induced formation of myocardial nitrotyrosine. CONCLUSION: These results indicate that superoxide anion and the resultant formation of peroxynitrite may substantially be involved in the pathogenesis of the cytokine-induced myocardial dysfunction in dogs in vivo.

Analysis of Variance↗
PubMed1998

Inhibition of adhesion molecules markedly ameliorates cytokine-induced sustained myocardial dysfunction in dogs in vivo.

Adhesion molecules are key molecules for inflammatory cardiovascular diseases and are known to be up-regulated by inflammatory cytokines. However, the role of adhesion molecules in the cytokine-induced myocardial dysfunction in vivo remains unclear. This role was examined in our novel canine model, in which chronic treatment of the heart with IL-1 beta-bound microspheres (MS), but not control MS, causes sustained myocardial dysfunction in vivo. The expression of P-selectin (mRNA and immunoreactivity) was more prominent in the IL-1 beta group than in the control group (treated with control MS alone) after MS injection. The extent of neutrophil infiltration and myocardial myeloperoxidase (MPO) activity were significantly increased in the IL-1 beta group (P < 0.01). Pre-treatment with SLeX-OS (a novel oligosaccharide analog of sialyl LewisX) or PB1.3 (a monoclonal antibody to P-selectin) prevented the myocardial dysfunction and significantly suppressed the neutrophil infiltration and the increase in myocardial MPO activity induced by IL-1 beta (P < 0.01 each). These results indicate that adhesion molecules play an important role in the pathogenesis of the cytokine-induced sustained myocardial dysfunction in dogs in vivo.

Animals↗
PubMed1997

[The preliminary results of prevention and treatment in the population of patients with COPD and cor pulmonale].

UNLABELLED: This paper tends to evaluate the effects of comprehensive prevention and treatment in COPD and cor pulmonale in the communities. A Randomized cohort with stratified design was undertaken in the rural areas with hundred thousand population in Beijing municipality, Lianning and Hubei Provinces, from spring 1992 to spring 1995. RESULTS: (1) the rates to all stratified populations under management were 85.6% among those with high risk, 87.8% among COPD and 83.6% among cor pulmonale, respectively. (2) The levels of KAB were raised more significantly in most intervention group than in control group which up +9.6% to +33.6% and -5.8% to +32.6%, respectively. (3) Comparisons between the two groups revealed: 1. Number of cigarette smokers who smoked more than before increased (20.1% vs 17.8%) but with no statistical significance. 2. The rate of smoking cessation went higher (15.5% vs. 11.3%, P < 0.01). 3. New high risk subjects were reduced (2.8% vs 3.9%, P < 0.01). 4. Number of new cor pulmonale patients decreased (19.9% vs 22.6%, P > 0.05) and mortality rate lowered (4.34% vs 4.78%, P > 0.05). CONCLUSION: preliminary results indicates that the active intervention is effective in reducing COPD and cor pulmonale among population at high risk in communities. However, it is necessary to point out that COPD and cor pulmonale are both having chronic nature which calls for patient and continuous efforts.

Adolescent↗
PubMed1993

[Analysis of the misdiagnoses of obliterative pulmonary hypertension].

In order to reduce the misdiagnostic rate of obliterative pulmonary hypertension (OPH), the clinical data was analysed of 126 cases of OPH, including 83 cases of unexplained pulmonary hypertension (UPH) and 43 cases of thromboembolic pulmonary hypertension (TEPH). The results showed that the misdiagnostic rate of UPH and TEPH was 93.98% and 79.07% respectively, with a total misdiagnostic rate of 88.89%. UPH was frequently misdiagnosed as congenital heart disease (63.86%), valvular heart disease (13.5%) and coronary heart disease (9.64%). TEPH was usually misdiagnosed as cardiomyopathy (37.21%), coronary heart disease (18.61%), and valvular heart disease (18.61%). The possible causes of misdiagnosis were discussed.

Adolescent↗
PubMed1992

[Perfusion lung scan in unexplained pulmonary hypertension].

Thirty-two patients were diagnosed as unexplained pulmonary hypertension by clinical history, physical examination, hemodynamics, pulmonary angiography and perfusion lung scanning. The findings of pulmonary scans in twenty patients (62.5%) showed patchy heterogeneous perfusion defects, which suggested chronic silent pulmonary thromboembolism (CSPT) and in twelve cases (37.5%) demonstrated normal or equally diffuse radionuclide scattering due to primary pulmonary hypertension (PPH). This result corresponded with the pathological data in some of the relevant references. Pulmonary perfusion scan is a noninvasive, safe and simple procedure for determining whether CSPT or PPH is the causative factor in patients with unexplained pulmonary hypertension.

Adolescent↗
PubMed1992

[An analysis of 21 cases of idiopathic dilatation of the pulmonary artery].

Idiopathic dilatation of the pulmonary artery (IDPA) is a disease which, generally speaking, does not need treatment. But a correct differential diagnosis is of great importance. 21 cases of IDPA were reported. The clinical data showed that 66.67% of the patients were asymptomatic and all the patients had normal respiratory and cardiovascular functions. 10% of the cases had had a history of more than 20 years. The results showed that IDPA was a benign anomaly and most of its symptoms were iatrogenic. It was usually misdiagnosed as pulmonary stenosis (42.86%), atrial septal defect (38.10%), pulmonary hypertension (28.57%), and so on. Careful chest X-ray, ECG and UCG examinations are useful for the differential diagnosis, but a clinical diagnosis should be based on the normal result of right heart catheterization.

Adolescent↗
PubMed1991

Association between high grade ventricular arrhythmia and extent of left ventricular hypertrophy in hypertrophic cardiomyopathy.

The association between the extent of left ventricular (LV) hypertrophy and severity of ventricular or atrial arrhythmias are examined. Two-dimensional echocardiography and 24-h Holter electrocardiography monitoring were performed in 60 patients with hypertrophic cardiomyopathy (HCM). According to the distribution of the LV hypertrophy, the patients were divided into three groups: 1. Apical hypertrophy (APH), 2. Septal hypertrophy, and 3. Extensive hypertrophy. Ventricular arrhythmias were found in 82% of the patients and supraventricular arrhythmias were detected in 70% of the patients. Lown grade III and IV arrhythmias occurred significantly more frequently in patients with extensive than with septal hypertrophy. Lown grade III to IV arrhythmias did not occur in patients with APH. Present results show a significant association between the extent of LV hypertrophy and the severity of ventricular arrhythmias in HCM.

Adult↗
PubMed1989

Chronic mountain sickness in Tibet.

A clinical syndrome identical to the chronic mountain sickness of the Andes occurs commonly in Lhasa, Tibet. It affects, almost exclusively, the immigrant Han population and develops after an average of 15 years' residence at high altitude. The early symptoms are attributable to polycythaemia--headache, dizziness, loss of memory and fatigue being prominent. In the later stages of the disease, dyspnoea and peripheral oedema develop. Haemodynamic investigations show pulmonary hypertension with a normal cardiac output and dilatation of the right ventricle in the long-established case. Respiratory gas studies provide evidence of alveolar underventilation and ventilation: perfusion inhomogeneity. Both clinical and investigatory data suggest that the earlier stages of the disease are dominated by polycythaemia, while cardiopulmonary involvement increases with the duration of the disease. The disease is rare in women and uncommon in Tibetans. Cigarette smoking appears to be a contributory factor.

Adult↗
PubMed1988

Subacute infantile mountain sickness.

A description is given of a disease of infants occurring in Lhasa, Tibet at an altitude of 3600 m. Typically if affects infants who have been born at low altitude and subsequently brought to residue in Lhasa, and it is usually fatal within a few weeks or months. There is extreme medial hypertrophy of muscular pulmonary arteries and muscularization of pulmonary arterioles, together with dilatation of the pulmonary trunk and massive hypertrophy and dilatation of the right ventricle. The disease is distinct from acute or chronic mountain sickness and appears to be the human counterpart of 'brisket disease' in cattle.

Altitude Sickness↗