Orthostatic hypotension and paroxysmal hypertension in humans with high spinal cord injury.

The spinal cord is essential for normal autonomic nervous system regulation of the cardiovascular system as the preganglionic neurons controlling the heart and blood vessels originate in the thoracolumbar spinal segments. The site and extent of a spinal cord injury determine the degree of autonomic involvement in cardiovascular dysfunction after the injury. After complete cervical cord lesions the entire sympathetic outflow is separated from cerebral control; this may cause orthostatic hypotension.

Differences in the association between type 2 diabetes and impaired microvascular function among Europeans and African Caribbeans.

Aims/hypothesis: Diabetes is associated with microvascular damage in all populations, but diabetic patients of Black African descent (African Caribbeans) have a greater risk of vascular target organ damage than would be anticipated for any given blood pressure level. We investigated whether this may be due to differences in the microvasculature.

Materials And Methods: To assess the maximum hyperaemic response to heating and the post-ischaemic response, Laser Doppler fluximetry was performed on 51 and 100 Europeans, and on 66 and 88 African Caribbeans with and without diabetes, respectively.

Heat-provoked skin vasodilatation in innervated and denervated trunk dermatomes in human spinal cord injury.

Study Design: Cross-sectional, observational, controlled study.

Objective: High spinal cord injury (SCI) results in disruption of sympathetic vasomotor control. Vasodilatation as a response to local heating is a biphasic mechanism: the first phase (neurogenic) is mediated by the axon-reflex and is modulated by activity of sympathetic nerves.

Ethnic differences in skin microvascular function and their relation to cardiac target-organ damage.

Background: People of Black African descent have increased risks of vascular target-organ damage not explained by greater blood pressures.

Objective: To study ethnic differences in the microvasculature.

Design And Methods: Flow (flux) in microcirculatory skin vessels was assessed using laser Doppler fluximetry in 181 Afro-Caribbean and European men and women aged 40-65 years from the general population in London, UK.

The use of recombinant human B-type natriuretic peptide (nesiritide) in the management of acute decompensated heart failure.

Nesiritide is a synthetic human B-type natriuretic factor that has a balanced arterial and venous dilator effect, with natriuretic, diuretic, anti-aldosterone and antisympathetic action. It was launched in the US for the treatment of acute decompensated heart failure (ADHF) in August 2001 and, recently, in Switzerland and Israel. It has been demonstrated to provide more rapid and sustained haemodynamic stabilisation than glyceryl trinitrate and significant symptomatic improvement vs.

The effects of water ingestion on orthostatic hypotension in two groups of chronic autonomic failure: multiple system atrophy and pure autonomic failure.

Background: Oral ingestion of water increases seated blood pressure in patients with chronic autonomic failure by mechanisms that remain unclear. As orthostatic hypotension is common in chronic autonomic failure, and is not always adequately controlled by medication, the potential benefits of water ingestion on standing blood pressure were studied in two types of autonomic failure: multiple system atrophy (MSA), in which the lesion is central and pre-ganglionic, and pure autonomic failure (PAF), in which the lesion is post-ganglionic.

Methods: In 14 patients with autonomic failure (seven PAF and seven MSA) standing blood pressure and heart rate were measured before, and 15 and 35 minutes after ingestion of 480 ml distilled water.

Role of autonomic evaluation in the diagnosis and management of syncope.

There are many causes of syncope that include neurological (autonomic and non-autonomic), cardiac and psychiatric causes, amongst others. Disorders of the autonomic nervous system, either intermittent or fixed, are increasingly recognised as contributing to a large proportion of syncope. However, the majority of guidelines focus on cardiological and neurological evaluation in these disorders.

Water drinking in the management of orthostatic intolerance due to orthostatic hypotension, vasovagal syncope and the postural tachycardia syndrome.

Water drinking recently has been shown to raise blood pressure in normal subjects and in patients with autonomic failure who have orthostatic hypotension. However, in normal young subjects, ingestion of approximately 500 ml has no pressor effect; but in older subjects there is an increase in blood pressure. An even greater rise in blood pressure occurs in cases with autonomic failure.

Ethnic differences in vascular stiffness and relations to hypertensive target organ damage.

Objective: People of Black African descent have greater risks of hypertensive target organ damage than would be anticipated for given levels of blood pressure. Arterial stiffness may further account for ethnic differences in risk.

Design: Cross-sectional study.

Pressor effect of water instilled via a gastrostomy tube in pure autonomic failure.

Background: The oral ingestion of water increases seated blood pressure in chronic autonomic failure although the mechanisms of this effect remain unclear. Recent studies in normal subjects suggest that oropharyngeal stimulation during swallowing may be of greater importance in causing a rise in blood pressure (BP) than the gastric effects of water. We therefore assessed the haemodynamic effects of water instilled directly into the stomach via a gastrostomy tube in pure autonomic failure (PAF).

Preventing food allergy.

In this review, we examine the critical periods of immune development and how these might be modified to prevent food allergy. The relevant dietary intervention studies, roles of microorganisms and their products, and other strategies are critically analyzed. Additionally, we highlight the potential importance of different routes of allergic sensitization and the role of oral tolerance induction in the pathogenesis and prevention of food allergy.