Koullis F. Pitsillides

Learn More
BACKGROUND Acupuncture is reported to reduce myocardial ischemia, arrhythmias, and hypertension. To investigate the physiological mechanisms underlying these observations, a model of reflex-induced, reversible myocardial ischemia was developed to test the effects of median nerve stimulation as a surrogate for electroacupuncture. METHODS AND RESULTS(More)
Biotelemetry provides high-quality data in awake, free-ranging animals without the effects of anesthesia and surgery. Although many biological parameters can be measured using biotelemetry, simultaneous telemetric measurements of pressure and flow have not been available. The objective of this study was to evaluate simultaneous measurements of blood flow,(More)
Acupuncture and electroacupuncture (EA) have been used in traditional Chinese medicine to treat a wide range of diseases and conditions, including angina pectoris and myocardial infarction. In a feline model of reflex-induced reversible myocardial ischemia, electrical stimulation of the median nerves to mimic EA (Neiguan acupoint) significantly improved(More)
The objective of this study was to evaluate a novel fully implantable radio-based blood flow biotelemetry system which allows simultaneously measurement of blood flow on two channels and temperature on one channel, in fish. These are the first recordings of blood flow from free-swimming fish, showing that the system is capable of recording blood flow in the(More)
The effects of thermoregulatory behaviours on gut blood flow in white sturgeon Acipenser transmontanus before and after feeding was studied using a blood flow biotelemetry system in combination with a temperature preference chamber. This is the first study to look at cardiovascular responses to feeding in white sturgeon, and also the first time behavioural(More)
BACKGROUND Myocardial ischemia is considered to be a possible stimulus for development of the coronary collateral circulation. We therefore hypothesized that chronic reduction of myocardial oxygen demand to lessen ischemia would attenuate coronary collateral development over an 8-week period using left circumflex coronary artery (LCx) ameroid-induced(More)
A three-channel biotelemetry system has been designed and implemented for use in a chronically instrumented animal model of cardiovascular disease. A dual-channel ultrasonic transit-time micrometer allows monitoring of left-ventricular wall motion for the regions perfused by the left circumflex and left anterior descending coronary arteries. A third channel(More)
Abdominal ischemia activates ischemically sensitive sympathetic visceral afferents and evokes reflex excitation of the cardiovascular system. These afferents respond to ischemic metabolites, including lactic acid, bradykinin, prostaglandins, and reactive oxygen species. Severe hypoxemia also has been shown to activate these afferents. It is not known,(More)
How blood flow and pressure to the giraffe's brain are regulated when drinking remains debated. We measured simultaneous blood flow, pressure, and cross-sectional area in the carotid artery and jugular vein of five anesthetized and spontaneously breathing giraffes. The giraffes were suspended in the upright position so that we could lower the head. In the(More)
We have developed an ultrasonic instrument that can measure absolute regional myocardial wall motion throughout the cardiac cycle using a single epicardial piezoelectric transducer. The methods in place currently that utilize ultrasound to measure myocardial wall thickness are the transit-time sonomicrometer (TTS) and, more recently, the Doppler echo(More)