St Bartholomew's Hospital

About: St Bartholomew's Hospital is a healthcare organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Cancer. The organization has 11054 authors who have published 13229 publications receiving 501102 citations. The organization is also known as: St. Bartholomew's Hospital & The Royal Hospital of St Bartholomew.

The composition of body tissues. (II) Fetus to young adult

Abstract: The composition of body tissues is a function of the age, nutrition, state of health and physical activity of the individual. In this paper, the effects of age on the composition of healthy tissues are reviewed. Eleven soft tissues (adipose tissue, blood--whole, brain--whole, heart, kidney, liver, lung, muscle--skeletal, placenta, skin and spleen) and cortical bone are considered. Elemental compositions, mass and electron densities are tabulated for the tissues, as a function of age, from fetus to young adult. Although the compositions given here are predominantly for healthy tissues, reported changes because of dietary influences are briefly discussed.

Somatostatin infusion lowers plasma ghrelin without reducing appetite in adults with Prader-Willi syndrome.

Abstract: Prader-Willi syndrome (PWS) is characterized by life-threatening childhood-onset hyperphagia, obesity and, uniquely, high plasma levels of ghrelin, the orexigenic gastric hormone. Somatostatin suppresses ghrelin secretion in normal subjects. We therefore examined the effect of somatostatin on plasma ghrelin and appetite in four male PWS adults fasted overnight in a double-blind, placebo-controlled, randomized cross-over study. Subjects received an intravenous infusion of somatostatin (250 microg/hr) or saline for 300 min, and had blood samples taken every 30 min for measurement of plasma ghrelin and PYY3-36 (anorexigenic intestinal hormone) by radio-immunoassay, and glucose. Appetite was measured by counting sandwiches eaten over a 60 min free food access period from +120 min. Despite somatostatin lowering fasting plasma ghrelin by 60 +/- 2% (P = 0.04) to levels seen in non-PWS men, there was no associated reduction in food intake (105 +/- 9% of food intake during saline infusion, P = 0.6). Somatostatin also lowered plasma PYY levels by 45 +/- 16% (P = 0.04), and produced post-prandial hyperglycemia (P = 0.04). We conclude that either hyperghrelinemia may not contribute to hyperphagia in PWS adults, or perhaps concomitant reductions in anorexigenic gastrointestinal hormones by somatostatin counteracted any anorexigenic effect of lowering orexigenic ghrelin. Somatostatin analogues may therefore not be an effective therapy for obesity in PWS. Larger chronic studies with long-acting somatostatin analogues will be needed to determine their benefits and risks in treating PWS obesity.

Impaired Nitric Oxide-Mediated Vasodilatation and Total Body Nitric Oxide Production in Healthy Old Age

Abstract: 1. Basal release of nitric oxide from the vascular endothelium maintains a constant vasodilating tone. Impaired nitric oxide-mediated vasodilatation has been described in hypertension and atheromatous disease. Circulatory diseases account for considerable morbidity and almost half of all deaths in people over the age of 75 years. 2. We have therefore compared nitric oxide-dependent vasorelaxation in 12 healthy elderly subjects with 12 young volunteers matched for blood pressure, cholesterol and glucose, using forearm occlusion venous plethysmography combined with brachial artery infusions of the nitric oxide synthase inhibitor, NG-monomethyl-L-arginine (L-NMMA; 1, 2 and 4 mumol/min) with noradrenaline (60, 120 and 240 pmol/min) as a control vasoconstrictor. We also measured urinary nitrate excretion after a controlled 48 h low nitrate diet as an index of total body nitric oxide production and correlated these changes with forearm blood flow responses to L-NMMA and noradrenaline in both groups. 3. The mean age and blood pressure of the elderly subjects was 76 (range 66-82) years and 132/76 (SEM 4/3) mmHg respectively, while in the young these were 27 (20-35) years and 131/72 (4/3) mmHg respectively. L-NMMA and noradrenaline produced dose-dependent reductions in forearm blood flow in both groups. L-NMMA (4 mumol/min) produced less vasoconstriction in the elderly than in the young (-37.7 +/- 2.6 versus -48.3 +/- 4.2%; P = 0.017). The mean slope of the L-NMMA dose-response curves in the elderly was significantly less than the younger group (-35.2 +/- 3.1 versus -63.7 +/- 10.6; P = 0.041). Noradrenaline, 240 pmol/min, also produced less vasoconstriction in the elderly compared with the young (-22.8 +/- 2.9 versus -35.3 +/- 5.0%; P = 0.029) although the slopes of the dose-response curves did not differ significantly. 4. Urinary nitrate adjusted for creatinine clearance was also significantly higher in the younger group (460.6 +/- 97.7 versus 205.9 +/- 64.8 mumol/day; P = 0.042) and showed a significant correlation with the percentage change in forearm blood flow in response to the maximum dose of L-NMMA (r = 0.5, P = 0.046). 5. We conclude that nitric oxide-mediated vasodilatation in the forearm vascular bed is diminished in old age and this reflects a more generalized reduction in nitric oxide production (as measured by urinary nitrate) in the circulation of older people. The blunted response to noradrenaline points to a more generalized reduction in vascular reactivity in the elderly.

Concerted activation of two potential proto-oncogenes in carcinomas induced by mouse mammary tumour virus.

Abstract: Concerted activation of two potential proto-oncogenes in carcinomas induced by mouse mammary tumour virus