Influence of comorbidities and medication use on tilt table test outcome in elderly patients.

Background: The tilt table test (TTT) is a useful diagnostic tool in people with unexplained syncope, dizziness, and falls. However, preexisting comorbidities and medications affecting hemodynamic response might affect TTT outcome (i.e.

Unprovoked and glyceryl trinitrate-provoked head-up tilt table test is safe in older people: a review of 10 years' experience.

Objectives: To test the safety of the head-up tilt test (HUT) in older adults.

Design: Direct observation and measurements.

Setting: Tests performed in a quiet room with dim lighting in a laboratory setting.

Nitric oxide-synthesising neurons in the central subnucleus of the nucleus tractus solitarius provide a major innervation of the rostral nucleus ambiguus in the rabbit.

We describe an intramedullary nitric oxide synthase (NOS) neural pathway that projects from the nucleus tractus solitarius (NTS) to the rostral nucleus ambiguus (NA) in the rabbit. With the use of NADPH diaphorase histochemistry and NOS immunohistochemistry, a compact group of NOS-positive perikarya was identified in the central subnucleus of the NTS dorsomedial to the tractus solitarius and rostral to the obex. A dense network of NOS terminals was seen in the rostral NA.

Fos-determined distribution of neurons activated during the Bezold-Jarisch reflex in the medulla oblongata in conscious rabbits and rats.

Experiments were performed in unanaesthetized rabbits and rats to investigate the distribution, within the medulla oblongata, of neurons activated during the Bezold-Jarisch reflex. Repeated intravenous injections of phenylbiguanide evoked depressor and bradycardic responses in both rabbits and rats. Fos-positive neurons were present in the nucleus tractus solitarius and in the caudal ventrolateral medulla oblongata.