Dave Singer

Learn More
20 patients with mild hypertension (average supine blood pressure without treatment, 164/101 mm Hg) reduced their salt intake to 50 mmol (3 g) per day for a month. They then entered a 3 month double-blind randomised crossover study of three levels of sodium intake: 200, 100, and 50 mmol per day. Blood pressure was significantly reduced on the middle and(More)
We recently showed that rarefaction of skin capillaries in the dorsum of the fingers of patients with essential hypertension is due to the structural (anatomic) absence of capillaries rather than functional nonperfusion. It is not known whether this rarefaction is primary (ie, antedates the onset of hypertension) or secondary (ie, as a consequence of(More)
A reduction in the density of capillaries (rarefaction) is known to occur in many tissues in patients with essential hypertension. This rarefaction may play a role in increasing peripheral resistance. However, the mechanism underlying this capillary rarefaction is not understood. The aim of this study was to assess the extent of structural versus functional(More)
1.BNP and ANP are important research indices of severity of heart failure. However, uncertainty regarding the stability of these peptides at room temperature has limited their use to assess cardiac function in routine clinical practice. 2. We assessed the stability of BNP and ANP in blood samples left for 2 h or 2 days at room temperature compared with(More)
A moderate reduction in salt intake lowers blood pressure in individuals with hypertension and improves blood pressure control in those taking a converting enzyme inhibitor. However, it is unclear how effective reduction of salt intake is compared with addition of other drugs, in particular, thiazide diuretics. We directly compared the separate effects on(More)
1. We have developed a radioimmunoassay for the measurement of immunoreactive brain natriuretic peptide (1-32) in human plasma. Simultaneous measurements of atrial natriuretic peptide have also been carried out to allow for direct comparison between circulating brain natriuretic peptide and atrial natriuretic peptide. Plasma levels of immunoreactive brain(More)
OBJECTIVE The aim was to examine the influence of cardiopulmonary bypass on brain natriuretic peptide (BNP) and on hormones of importance in the control of sodium and water balance and blood volume. METHODS Nine patients (mean age 4 years, range 2-9) undergoing cardiac surgery were studied. Blood samples were taken before, during, and up to 24 h after(More)
1. Hormones involved in cardiovascular regulation are influenced by drug treatment. It is therefore difficult to study endocrine mechanisms in heart failure as most patients are already on treatment by the time they reach hospital. 2. We studied nine hospital in-patients before and after treatment of acute New York Heart Association class IV heart failure.(More)
BACKGROUND Rarefaction of skin capillaries in people with intermittent borderline essential hypertension suggests a primary or an early abnormality that may antedate the onset of sustained hypertension. OBJECTIVE To compare skin capillary density in subjects with and without a family history of essential hypertension. SUBJECTS 21 normotensive(More)
OBJECTIVE To compare measurement of left ventricular mass (LVM) by M-mode echocardiography and magnetic resonance imaging (MRI) in hypertensive subjects. DESIGN A prospective study. SUBJECTS Twenty-four untreated hypertensive patients [19 men and five women, aged 51 +/- 2 (mean +/- SEM) years, supine blood pressure 159/101 +/- 3/1 mmHg]. SETTING The(More)