Before introducing the first panel of pathogenesis experts I want to discuss a figure (Fig. 1) which you may find helpful when considering the complex problems connected with the development of atherosclerosis. This figure attempts to present, in a simplified form, the major components of the pathogenesis of atherosclerosis starting, first of all, with the concept, now based on abundant evidence, that one of the critical factors in the development of this disease is a sustained increase in the concentration of circulating low density lipoprotein. The second point of the illustration is that platelet sticking and/or a tendency toward clotting may help open the endothelium to increased migration of lipids and/or formed elements of the blood into the intima or even the media. The third line indicates that other factors such as hypertension, anoxia and various circulating toxins may also increase endothelial permeability with or without platelet sticking.

The purpose of the study was to determine whether Infrared imaging could play a role in the detection of previous blunt force injury after resolution of skin changes were no longer visible to the human eye. Investigations were performed using an adapted digital camera and the same standard Nikon camera body to photograph the bruises of ten volunteer adult subjects. The same lens was fitted to each camera body and each bruise was photographed until it was no longer possible to identify it with the naked eye. The results of photographing subjects over 6 months demonstrated that the median time the bruises persisted in both groups was approximately between 18 and 19 days. There was no statistically significant difference between groups of bruises photographed with both the infrared digital camera that had been adapted to capture only infrared light, and with the standard camera which had the same lens fitted to it. The two groups of photographs of bruises imaged at the same time with the two cameras were not significantly different with regard to what skin changes could be detected. The use of the near infrared spectrum, with wavelengths that are longer than the human eye can detect, did not reveal significant evidence of bruising after it had faded from view to both the human eye and to a standard camera.

This work was inspired by a recent case of child abuse where the question of the age of the bruises on the body was raised. The first part of this paper reviews published work on bruises. It illustrates the paucity of work in this field and the absence of studies of the colour changes in bruises of human skin with time. The second part of this paper consists of our own study of the appearance of bruises. The aim was to identify the colour changes which occur in bruises and over what time-scale, in order to determine whether bruises can be aged by appearance. A total of 369 photographs were obtained of bruises aged <6 h and up to 21 days old, in 89 subjects aged 10–100 years. It was found that the development of a yellow colour was the most significant change (subjects aged <65, P < 0.001; subjects aged ≥65 years, P < 0.001). The development of a yellow colour occurred significantly faster in subjects aged < 65 years. (P < 0.001). The appearance of a blue and purple/black colour was of lesser significance. The appearance of a red colour did not alter significantly with time. From this study it was only possible to conclude that a bruise with a yellow colour was more than 18 h old.

Fat embolism is a condition that is underdiagnosed clinically and at autopsy. This paper reviews the causes and pathogenesis of the condition and indicates possible modes of therapy.

PROCEIDINOS OF TH4E BIOCHEMICAL SOC12TY 41 p containing 1 % of Pb.However, it was found that the catalytic activity of pure CuO was greater than that of CuO containing Pb.The lower activity of the catalyst containing Pb may be due to the blocking of the pores by the deposition of Pb, which forms a diffusion barrier preventing the reacting substances fromn reaching the active catalyst surface.

Groups of 5–8 baboons were fed either a control or hypercholesterolaemic diet for 6 months. During the last 90 days, each group was given 5 i.v. injections of bovine serum albumin (BSA) at 16 day intervals or control injections of saline. Only those animals which were both hypercholesterolaemic and injected with BSA developed aortic and coronary atherosclerosis.

The phospholipid classes of total plasma and of α- and β-lipoproteins, in baboons given control and atherogenic diets, have been studied using the techniques of electrochromatography (ECG), thin-layer chromatography (TLC) and gas-liquid chromatography (GLC).

In rabbits fed an atherogenic semi-synthetic diet, the following were found: in the aortic wall, decreased cholesterol esterase and increased lipase and phospholipase A activities, no changes in malate and lactate dehydrogenase activities, enhanced incorporation of free fatty acid into cholesterol esters, and increased accumulation of mainly esterified and also free cholesterol; increase in plasma cholesterol and serum phospholipase A activity but no change in liver phospholipase A and serum and liver lipase activities.

Regression mechanism of Ethyl 2-(p-chlorophenoxy) isobutyrate (CPI B) in the arterial wall was studied for elucidation in terms of fatty acid-compositional change in cholesterol-fed rabbits. The following evidence was obtained: (1) The amount of cholesterol and cholesteryl ester in the atheromatous aorta were reduced after CPIB treatment. (2) CPIB resulted in a significant increase in the ratio of linoleate to oleate in both the arterial wall and serum after withdrawal of the cholesterol diet. It is suggested that there is a preferential hydrolysis of linoleate-rich cholesteryl ester in both the arterial wall and the serum.

DURING investigations into the population dynamics of the European wild rabbit (Oryctolagus cuniculus L.) on the island of Skokholm, Pembrokeshire, an abnormal condition of adipose tissue was observed. The condition is apparently unknown in rabbits elsewhere, except on the adjacent island of Skomer, and is hitherto undescribed.

1. The object of the experiment was to investigate the detailed carcass composition, and the fatty acid composition of the depot fat, of pigs fed from 10 Ib. to almost 200 lb. live weight on semi-synthetic isocaloric diets containing no fat, saturated fat (beef tallow) and unsaturated fat (maize oil).2. The carcasses of seven litter-mate Large White x Essex hogs, two from each semi-synthetic diet and one from a natural diet were dissected into their individual muscles, bones, fat depots and remainder.

Thrombosis of the cardiovascular system, and myocardial and renal infarction can be produced in the rat by feeding hypercholesterolaemic diets containing butter, cholesterol, cholic acid and thiouracil. This experimental system has been studied from the nutritional, blood coagulation and biochemical aspects.

Hypercholesterolaemia and atherosclerosis can be produced in rabbits by feeding a semi-synthetic diet containing 20 % beef fat without added cholesterol. Atromid fed at a level of 0.3 % w/w in the diet will significantly reduce plasma cholesterol levels in such animals, but has no effect on the severity of the atherosclerotic lesions.

The early atherosclerotic lesion of man is described and compared with that seen in naturally occurring disease in animals and in the experimental animal. A prototype lesion composed of collagen, elastin, mucopolysaccharide and some lipid is common to all and suggests that the early atherosclerotic lesion in man and animals begins as a repair to injury the cause of which is unknown.