Analysis of arterial intimal hyperplasia: review and hypothesis

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: Despite a prodigious investment of funds, we cannot treat or prevent arteriosclerosis and restenosis, particularly its major pathology, arterial intimal hyperplasia. A cornerstone question lies behind all approaches to the disease: what causes the pathology? Hypothesis: I argue that the question itself is misplaced because it implies that intimal hyperplasia is a novel pathological phenomenon caused by new mechanisms. A simple inquiry into arterial morphology shows the opposite is true. The normal multi-layer cellular organization of the tunica intima is identical to that of diseased hyperplasia; it is the standard arterial system design in all placentals at least as large as rabbits, including humans. Formed initially as one-layer endothelium lining, this phenotype can either be maintained or differentiate into a normal multi-layer cellular lining, so striking in its resemblance to diseased hyperplasia that we have to name it "benign intimal hyperplasia". However, normal or "benign " intimal hyperplasia, although microscopically identical to pathology, is a controllable phenotype that rarely compromises blood supply. It is remarkable that each human heart has coronary arteries in which a single-layer endothelium differentiates earl

Great Britain: the intertidal and underwater archaeology of Britain’s submerged landscapes

The submerged landscapes around Great Britain are extensive and would have offered productive territory for hunting, gathering, exploitation of aquatic and marine resources, and—in the final stages of postglacial sea-level rise—opportunities for agriculture. They would also have provided land connections to continental Europe and opportunities for communication by sea travel along now-submerged palaeocoastlines and river estuaries. Most of the archaeological material has been discovered in intertidal or shallow water conditions, but there are also discoveries in deeper water, with dates ranging from earliest human presence nearly one million years ago up to the establishment of modern sea level. Some later material is present where coastlines have continued to sink in more recent millennia. Intertidal sites are especially well represented because of relatively large tidal ranges and shallow offshore gradients on many coastlines. These are often associated with remains of submerged forests, which are periodically exposed at low tide and then covered up again by movements of sand. Some of the most distinctive intertidal finds are the human and animal footprints preserved in intertidal sediments in many locations, especially at Goldcliff East. The earliest, at Happisburgh, are dated between 0.78 and 1 Ma. Fully submerged sites include the Mesolithic site of Bouldnor Cliff with its worked timbers, and the Middle Stone Age artefacts from offshore aggregate Area 240 along with well-preserved ice age fauna and environmental indicators. Pioneering work using oil industry seismic records has produced detailed reconstructions of the submerged landscape, and this is being followed up by new work involving targeted acoustic survey and coring of sediments

Highlights of the DNA cutters:a short history of the restriction enzymes

In the early 1950’s, ‘host-controlled variation in bacterial viruses’ was reported as a non-hereditary phenomenon: one cycle of viral growth on certain bacterial hosts affected the ability of progeny virus to grow on other hosts by either restricting or enlarging their host range. Unlike mutation, this change was reversible, and one cycle of growth in the previous host returned the virus to its original form. These simple observations heralded the discovery of the endonuclease and methyltransferase activities of what are now termed Type I, II, III and IV DNA restriction-modification systems. The Type II restriction enzymes (e.g. EcoRI) gave rise to recombinant DNA technology that has transformed molecular biology and medicine. This review traces the discovery of restriction enzymes and their continuing impact on molecular biology and medicine