Bruce Warren

Calcification of the aortic valve: its progression and grading.

Summary Three hundred and seventy four aortic valves which had been surgically removed over the past five years were studied by routine histology. Most patients were male and over the age of 60 years. There were 3.7% bicuspid valves, 16% valves with evidence of past rheumatic fever and 2.1% with endocarditis. A range of pathological lesions was seen including calcification, chondroid and osseous metaplasia, neovascularization, inflammation and cholesterol deposition. A common lesion was a progressive dystrophic calcification of the valve cusps. This was studied and graded in relationship to the concomitant structural damage. There has been no previously published grading system for this type of pathological change in the aortic valve. Our criteria for the four grades of aortic valve lesion are described. Most patients were found to have lesions of Grades 3 and 4.

Calcified deposit formation in intimal thickenings of the human aorta

The formation of calcified deposits in intimal thickenings of human aorta was studied by electron microscopy. Microzones of calcification were detected in about 20% of fatty streaks and were located predominantly in the deep musculoelastic layer of the intima. Calcified deposits formed only on previously existing structures including extracellular vesicles and unesterified cholesterol. Calcified deposits in the musculoelastic layer of the intima localised inside altered elastin fibres, but initiating the calcification of of elastin required the prior accumulation of cholesterol esters inside elastin fibres. Co-localization of calcified deposits and elastin fibres was followed by destruction of elastin. The present study suggests that at an early stage of development is atherosclerotic lesions, calcified deposits are formed by a physicochemical process which is not strongly controlled by the intimal cells. The recognition of calcified deposits in intimal thickenings support the hypothesis that a subset of fatty streaks might progress to fibrous plaques in human atherosclerosis.

A practical approach to the diagnosis of renal disease by biopsy

&NA; The pathologist has an important role in the diagnosis and monitoring of renal disease. However, for optimal useful information to be derived from renal biopsy specimens, certain guidelines must be adhered to and these are enunciated here. The 3 avenues of observation of renal biopsies viz. light microscopy, immunofluorescence and electron microscopy, all have important roles to play and give differing data which informs the diagnosis for the renal biopsy report. The relative emphasis on each of these modalities of investigation will vary depending upon the situation in which the renal biopsy is performed. The methods used here have been shown to be effective in practice over a period of 20 yrs. Although there may be variations in methodology from centre to centre, the general background aims and principles remain the same. The emphasis in this paper has been on common practical aspects of renal biopsies. Much of the practical information concerning renal biopsies, which is brought together here, is otherwise scattered and not readily available. The aim of this article is to allow the reader to understand the rationale for the steps that are involved in renal biopsy diagnosis.

Neurocysticercosis: a report of four cases

&NA; Cysticercosis is an uncommon disease in Australia. Only 4 cases of neurocysticercosis were found in our hospital with an active neurosurgical service over a 10 yr period. All 4 cases were migrants, 3 from South America and one from Cyprus. Epilepsy, aseptic meningitis and raised intracranial pressure were the common symptoms. Although the cerebral lesions were seen on CT scans, misinterpretation of the X-ray appearances readily occurs and the diagnosis can only be confirmed by histopathological examination of tissues. The pathological features are described including electron microscopy of one case. The cysticercus has a unique ultrastructure which is most helpful in establishing the diagnosis in cases where tissue sample is small and light microscopy is difficult. Neurocysticercosis can masquerade as a glioma or other space occupying lesion or aseptic meningitis. This condition should be considered in obscure neurological syndromes in migrants from affected regions of the world.

The scanning electron microscopy of scolices in a case of hydatid cyst from human liver

&NA; The scanning electron microscopic (SEM) features of hydatid scolices from a case of hydatid disease of the liver are described. The scolex when fully everted has a double circle of hooklets which occupy a large area of the parasite. The hooklets are inserted into the rostellum with one row of hooklets overlapping the other. Each hooklet is about 20 to 40 um long, has a basic round structure sharp at the distal end and broadens as it curves towards the point of insertion at the rostellum, where 2 blunt projections correspond to the 2 annular bundles of muscle fibres at the orifice of the scolex. The function of the hooklets is not fully understood but they are possibly used for anchorage and/or for the purpose of propulsion in a fluid medium by the act of invagination and evagination of the hooklets.

Photography of immunofluorescence results in renal biopsies.

&NA;Abbreviations: IF, immunofluorescence.

Renal granulomatous angiitis — a case report

&NA; A case of non‐necrotizing granulomatous angiitis without significant glomerular pathology is described in a 61 yr‐old female. The characteristic lesion consists of periarterial inflammation comprizing a mixed population of mononuclear cells with prominent giant cell formation. There is no evidence of immunoglobulin, complement or fibrin deposition. It is concluded that this represents an unusual variant of polyarteritis nodosa which is apparently controlled by steroid therapy.