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C P Cheng

Publications and source records attributed to C P Cheng.

66 records · Page 4Linked to original sources

Response of the left ventricular end-systolic pressure-volume relation in conscious dogs to a wide range of contractile states.

We assessed the linearity and slope of the left ventricular end-systolic pressure (PES)-volume (VES) relation over a wide range of contractile states in conscious dogs. The animals were instrumented to determine left ventricular volume from ultrasonic left ventricular internal dimensions and measure left ventricular pressure with a micromanometer. Studies were performed 1-2 weeks after instrumentation while the animals were conscious. Contractile state was increased by incremental infusion of dobutamine (0, 2, 4, 6, and 8 micrograms/kg/min i.v.) and decreased by verapamil (10 mg i.v.) given after autonomic blockade. The 44 +/- 11 mm Hg (mean +/- SD) portion of the PES-VES relation generated by bicaval occlusion demonstrated a slight but consistent nonlinearity, apparent as a concavity toward the volume axis. This nonlinearity, present at all inotropic states, did not prevent the PES-VES relation from being well approximated by a straight line (r = 0.984 +/- 0.020, SEE = 2.1 +/- 1.4 mm Hg); furthermore, the slope of the PES-VES line provided a sensitive index of contractile state, progressively increasing with incremental doses of dobutamine and decreasing in response to verapamil. The volume-axis intercept of the linear approximation of the PES-VES relation was 2.9 +/- 3.3 ml less (p less than 0.05) than the volume-axis intercept of the nonlinear quadratic fit. Thus, the linear PES-VES relation, whose slope is sensitive to a wide variety of inotropic states, is a reasonable and useful description of the left ventricle in the range of PES-VES points that can be produced by bicaval occlusion in the conscious dog. However, linear extrapolation of the relation beyond the range of data points may not be accurate.

Animals↗

Endotoxin shock and tumour necrosis factor release in mannoheptulose-treated mice.

Administration of mannoheptulose partially protected mice infected with Listeria monocytogenes against the lethal effect of a subsequent endotoxin challenge. The ability of these animals to produce tumour necrosis factor was however unaffected. Mannoheptulose was observed to reverse the hypoglycaemic effect of endotoxin, possibly through inhibition of insulin secretion. The therapeutic significance of these observations is discussed.

Animals↗

Effect of anti-inflammatory drugs on the production of tumour necrosis factor and lipopolysaccharide induced-mortality in mice.

Mice injected with viable Listeria monocytogenes or powdered Corynebacterium parvum and challenged with endotoxin released tumour necrosis factor (TNF) into the blood. However, the rate of mortality from endotoxin shock was high. Administration of the non-steroidal anti-inflammatory drugs acetylsalicylate, indomethacin and phenylbutazone protected the animals against the lethal effect of endotoxin without affecting the ability of animals to produce TNF. The significance of these observations are discussed.

Animals↗

Haemodynamic changes in adrenaline-induced acute massive lung oedema.

During the production of adrenaline-induced acute massive lung oedema in the dog, plumonary arterial, pulmonary venous, systemic arterial, and bronchial arterial blood pressures all increase markedly. Pulmonary arterial and venous blood flows fall steeply after initial transient rises. Systemic arterial blood flow also declines, with or without an initial transient increase. The bronchial arterial blood flow shows an initial fall followed by a rise of late onset. The main determinant for the pathogenesis of adrenaline-induced lung oedema is apparently the enormously increased hydrostatic pressure in the pulmonary vascular bed.

Animals↗

Adrenaline-induced acute massive pulmonary oedema in the dog.

Pericardiotomy followed by intravenous injection of adrenaline (1 mg/kg body weight) provides a reliable method for the production of acute massive lung oedema in the dog. The lung wet weight: heart wet weight ratio is found to be the best assessment of the degree of lung oedema. A ratio greater than two represents massive lung oedema.

Animals↗

Characterization of group D1 non-typhoid Salmonella isolates by serotyping and pulsed field gel electrophoresis.

Non-typhoid salmonella infection is not uncommon in immunocompetent patients in Taiwan. Bacterial factors may play an important role in the pathogenesis of such infections. In a previous study, Salmonella group D1 was found to have the tendency to cause bacteremia with a higher frequency than other serotypes. In the present study, we prospectively collected 94 Salmonella group D1 isolates for serotyping and molecular typing. Salmonella panama and Salmonella dublin seemed more invasive than other serotypes. Pulsed field gel electrophoresis was also done to characterize of Salmonella enteritidis and Salmonella dublin. PFGE type "a" of Salmonella dublin appeared to be more invasive than the other two PFGE types. All six Salmonella dublin isolates were Vi antigen negative. Further study using a larger number of isolates is needed to identify the tendency to invade blood stream of Salmonella dublin and Salmonella panama.

Adult↗