Opera Occulta

With a mixture of pride and humility I began to turn the pages of the great leather-backed volumes which enclose the early Dissertations of the Royal Medical Society. It was something to be done with care, for the pages are brittle and cachetic. The regular, flowing, almost copper-plate writing is only s lightly faded and is eminently legible. We, who can achieve immaculate script only through the medium of machinery, might pause and consider the scholarship of our predecessors who wrote Greek, Latin or English with artists’ hands

The Use of Controls in the Assessment of Clinical Evidence

The prize-winning essay from the B.M.A. Essay Competition for Provisionally Registered General Practitioners. 1961. The essay is abridged.The incorporation of standards or controls into clinical experimentation has become, over the past decade, a widely accepted practice. So much so that there is a danger that the medical profession in general may become uncritical of the practical and, more important, the ethical problems involved. The subject should be under constant review.Are controls really necessary? How best can they be employed? How is the resulting evidence to be assessed? Under what circumstances can the use of controls be justified on ethical grounds

Mapping and Prediction of Coal Workers’ Pneumoconiosis with Bioavailable Iron Content in the Bituminous Coals

Based on the first National Study of Coal Workers’ Pneumoconiosis (CWP) and the U.S. Geological Survey database of coal quality, we show that the prevalence of CWP in seven coal mine regions correlates with levels of bioavailable iron (BAI) in the coals from that particular region (correlation coefficient r = 0.94, p < 0.0015). CWP prevalence is also correlated with contents of pyritic sulfur (r = 0.91, p < 0.0048) or total iron (r = 0.85, p < 0.016) but not with coal rank (r = 0.59, p < 0.16) or silica (r = 0.28, p < 0.54). BAI was calculated using our model, taking into account chemical interactions of pyrite, sulfuric acid, calcite, and total iron. That is, iron present in coals can become bioavailable by pyrite oxidation, which produces ferrous sulfate and sulfuric acid. Calcite is the major component in coals that neutralizes the available acid and inhibits iron’s bioavailability. Therefore, levels of BAI in the coals are determined by the available amounts of acid after neutralization of calcite and the amount of total iron in the coals. Using the linear fit of CWP prevalence and the calculated BAI in the seven coal mine regions, we have derived and mapped the pneumoconiotic potencies of 7,000 coal samples. Our studies indicate that levels of BAI in the coals may be used to predict coal’s toxicity, even before large-scale mining

Res Medica, Autumn 1961, Volume 3, Number 1

TABLE OF CONTENTSPERFUSION: Professor W.A. MackeyABDOMINAL CRISES 1: I.S.R. Sinclair, F.R.C.S.FIBRINOLYSIS AND OCCLUSIVE VASCULAR DISEASE: J.D. Cash, B.Sc., M.B., CH.B.RES MEDICATHE UNBORN CHILD: Professor C.S. RussellTHE USE OF CONTROLS IN THE ASSESSMENT OF CLINICAL EVIDENCE: C.V. Ruckley, M.B., CH.B."THE SLIMY MUD OF WORDS":H.C. Drysdale, M.B., CH.B.THE HARVEIAN ORATION, 1961: Dr. J.K. Slater, O.B.E., M.D.MELANCHOLIA: E.B. Ritson, M.B., CH.B

Res Medica, Spring 1958, Volume 1, Number 2

TABLE OF CONTENTSTHE ROYAL MEDICAL SOCIETY TO-DAYTHE CONCEPTUAL BASIS OF MODERN SURGERY: Professor John Bruce, C.B.E., T.D., P. R.C.S.E., F.A.C.S. (HONS.)SOME PATHOLOGICAL ASPECTS OF DISSECTING ANEURYSM: M. J.MacLeanCHANGING FASHIONS IN DIABETES: Professor D. M. Dunlop, B.A., M.D., F. R.C. P. F. , F.R.C.P.OPERA OCCULTA: C. Vaughan RuckleySOME ASPECTS OF NUTRITIONAL AND TOXIC LIVER INJURY: A. W. DellipianiSIR JAMES YOUNG SIMPSON: William L.FordTHE AETIOLOGY OF DISSEMINATED SCLEROSIS: J. G. TurnbullHAZARDS OF RADIATION: Andrew Gun

Length of carotid stenosis predicts peri-procedural stroke or death and restenosis in patients randomized to endovascular treatment or endarterectomy.

BACKGROUND: The anatomy of carotid stenosis may influence the outcome of endovascular treatment or carotid endarterectomy. Whether anatomy favors one treatment over the other in terms of safety or efficacy has not been investigated in randomized trials. METHODS: In 414 patients with mostly symptomatic carotid stenosis randomized to endovascular treatment (angioplasty or stenting; n = 213) or carotid endarterectomy (n = 211) in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS), the degree and length of stenosis and plaque surface irregularity were assessed on baseline intraarterial angiography. Outcome measures were stroke or death occurring between randomization and 30 days after treatment, and ipsilateral stroke and restenosis ≥50% during follow-up. RESULTS: Carotid stenosis longer than 0.65 times the common carotid artery diameter was associated with increased risk of peri-procedural stroke or death after both endovascular treatment [odds ratio 2.79 (1.17-6.65), P = 0.02] and carotid endarterectomy [2.43 (1.03-5.73), P = 0.04], and with increased long-term risk of restenosis in endovascular treatment [hazard ratio 1.68 (1.12-2.53), P = 0.01]. The excess in restenosis after endovascular treatment compared with carotid endarterectomy was significantly greater in patients with long stenosis than with short stenosis at baseline (interaction P = 0.003). Results remained significant after multivariate adjustment. No associations were found for degree of stenosis and plaque surface. CONCLUSIONS: Increasing stenosis length is an independent risk factor for peri-procedural stroke or death in endovascular treatment and carotid endarterectomy, without favoring one treatment over the other. However, the excess restenosis rate after endovascular treatment compared with carotid endarterectomy increases with longer stenosis at baseline. Stenosis length merits further investigation in carotid revascularisation trials