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M X Shi

Publications and source records attributed to M X Shi.

6 recordsLinked to original sources
PubMed1994

The dynamic change of plasma endothelin-1 during the perioperative period in patients with rheumatic valvular disease and secondary pulmonary hypertension.

The arterial plasma endothelin-1 concentration was substantially more elevated in 15 patients with rheumatic valvular disease and secondary pulmonary hypertension than in healthy volunteers (3.66 +/- 2.20 versus 1.17 +/- 0.38 pg/ml, mean +/- standard deviation; p < 0.01). The preoperative plasma endothelin-1 level was highly correlated with the pulmonary hemodynamics: pulmonary artery systolic pressure (r = 0.94, p < 0.001), pulmonary artery mean pressure (r = 0.86, p < 0.001), pulmonary capillary wedge pressure (r = 0.82, p < 0.001), and pulmonary vascular resistance (r = 0.63, p < 0.02). After valve replacement, the plasma endothelin-1 concentration declined substantially and the pulmonary hemodynamics improved markedly. Two weeks after the operation, the plasma endothelin-1 level in patients (1.26 +/- 0.45 pg/ml, mean +/- standard deviation) was not statistically different from that in the healthy volunteers. The plasma endothelin-1 concentration continuously increased during the course of cardiopulmonary bypass and peaked after cessation of bypass. The peak plasma endothelin-1 level (13.49 +/- 4.60 pg/ml, mean +/- standard deviation) positively correlated with the bypass time (r = 0.64, p < 0.02) and negatively correlated with the urine volume during bypass (r = -0.69, p < 0.01). We conclude that (1) increased plasma endothelin-1 might be implicated in the pathogenesis of secondary pulmonary hypertension caused by rheumatic valvular disease and (2) markedly elevated plasma endothelin-1 concentrations might be associated with the mechanism of cardiac or renal dysfunction after prolonged cardiopulmonary bypass.

Adult↗
PubMed1994

[Hamartoma of the lung: an analysis of 24 cases].

Hamartoma is one of the most common benign tumors in the lung, and most of the lung hamartomas are located in the parenchyma. This report reviews 24 cases with this kind of tumor. The male-female ratio was 1.4:1 and the mean age 46.4 years. Sixteen patients of the 24 were asymptomatic, while in the remainder cases chest pain or distress, cough, short breath or hemoptysis were presented. Lung hamartoma is usually composed of cartilage, fat, smooth muscle and respiratory epithelium. X-ray findings of the parenchymal type in these cases were characterized by a round or oval sharply outlined mass, but only one with a mass in the shape of a dumbbell. 33% cases showed calcification. In 19 cases the mass was < 3.0 cm diameter (79%) and in 17 it was located in the superficial edge of the lung. The diagnosis was confirmed in only 6 cases preoperatively. The other cases were misdiagnosed as lung cancer, tuberculoma, metastatic tumors of the lung, etc. Enucleation or wedge resection is desirable for this kind of tumor.

Adult↗
PubMed1990

The role of tachykinins in air ventilation-induced bronchoconstriction in postmortem guinea pigs.

To investigate the relationship between tachykinins and air ventilation-induced airway constriction after heart ligation, 26 guinea pigs were divided into three groups: Group 1, control (n = 15); Group 2, tachykinin depletion via pretreatment with capsaicin (n = 7); and Group 3, isocapnic ventilation (n = 4). To examine the age effect, the first two groups were further separated into two subgroups: young (n = 12) and mature (n = 10). Animals were anesthetized with pentobarbital, sternotomized and artificially ventilated with room air or with 5% CO2 gas mixture. Before (baseline) and after heart ligation, tidal volume and transpulmonary pressure (Ptp) were recorded during ventilation, and the maximal expiratory flow-volume curve was periodically obtained. Minimal volume (lung volume at Ptp = 0) was determined by neon dilution. Within 30 min after heart ligation in the control group, air ventilation significantly decreased dynamic compliance, vital capacity, peak maximal expiratory flow, maximal expiratory flow at 50% total lung capacity, and forced expiratory volume in 0.2 sec. Tachykinin depletion significantly prevented, whereas isocapnic (5% CO2) ventilation failed to alter, the above changes. Young and mature subgroups showed similar results. Our data indicate that air ventilation after heart ligation induced severe airway constriction and that this bronchoconstriction can be prevented by tachykinin depletion.

Animals↗