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.

A survey on intron and exon lengths

Abstract: The lengths of introns and exons in various parts of genes of vertebrates, insects, plants and fungi are tabulated. Differences between the various groups of organisms are apparent. The results are discussed and support the idea that, generally speaking, introns were present in primitive genomes, though in some cases they may have been inserted into pre-existing genes.

Involvement of nitric oxide in the reflex relaxation of the stomach to accommodate food or fluid

Abstract: The fundus of the guinea-pig stomach actively dilates in response to low increases in intragastric pressure. This physiological response, now called adaptive relaxation, accommodates the intake of liquid or food. It is independent of external innervation, resistant to ganglion blockade, but reflex in origin. The nerves involved are neither adrenergic nor cholinergic in nature. Non-adrenergic, non-cholinergic (NANC) nerves have now been recognized in many parts of the gastrointestinal tract and have recently been linked with release of nitric oxide (NO) on electrical stimulation. Here we show that adaptive relaxation in isolated stomach of the guinea pig is mediated by a NANC neurotransmitter substance indistinguishable from NO derived from L-arginine. This is substantiated by inhibition of adaptive relaxation by NG-monomethyl-L-arginine or N omega-nitro-L-arginine methyl ester, both inhibitors of NO synthesis, and by methylene blue, an inhibitor of soluble guanylate cyclase. There are two distinct neuronal pathways signalling NO-dependent adaptive relaxation, as evidenced by tetrodotoxin sensitivity. The first is a local reflex arc, the afferent fibres of which sense changes in intragastric pressure. The second is stimulated by an agonist for ganglionic nicotinic receptors. Thus, the functional significance of NO release from NANC nerves in the stomach is to bring about adaptive relaxation through a reflex response to increases in intragastric pressure.