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Biomedical subjects

K J Donald

Publications and source records attributed to K J Donald.

At least 37 records · Page 2Linked to original sources
PubMed1976

Necropsy as a control of death certification: some unexpected findings.

A comparison of death certificates and necropsy findings in a group of premenopausal women suggests that a number of diseases are either underdiagnosed in life. Atypical cases of intracerebral haemorrhage are frequently misdiagnosed. These occur in the frontal, temporal or parietal lobes in non-hypertensive women and may be suitable for surgical treatment. Their aetiology remains obscure. Pulmonary embolus is habitually underdiagnosed in premenopausal women and myocardial infarcts appear to be overdiagnosed. The study reemphasizes that death certificates are inaccurate and that low necropsy rates render accurate statistics of diseases in the community difficult ot obtain.

Adult↗
PubMed1976

An ultrastructural study of the pathogenesis of tissue injury in limited Wegener's granulomatosis.

Intravascular lysis of leucocytes was an early event in the process of tissue injury in a patient with limited Wegener's granulomatosis. This lysis, with consequent liberation of free organelles into the circulation, was followed by platelet aggregation and fibrin deposition in vessels with intact endothelial cells. Necrosis of endothelial cells also occurred early in the tissue injury. Complete obstruction of vessel lumina, with necrosis of their walls and of alveolar pneumocytes, followed. The alveolar spaces filled with fibrin and cell debris, and macrophages and fibroblasts migrated into these areas. The ultrastructural findings offer a rationale for current therapy. Cyclophosphamide therapy led to improvement in the clinical state, pulmonary function and histological changes.

Capillaries↗
PubMed1975

The relative roles of platelets and macrophages in clearing particles from the blood; the value of carbon clearance as a measure of reticuloendothelial phagocytosis.

The correlation between detailed kinetic studies and ultrastructural localisation of particles during carbon clearance in normal animals illustrates that single order kinetics are not always obtained and phagocytosis is not always the major clearing process. During the early stages of clearance adherence of particles to platelets and to macrophage surfaces without immediate phagocytosis, as well as aggregation of particles within the blood are important controlling factors in the usual light absorbance techniques used to measure rates of clearance. The importance of the various processes involved varies depending upon the dose of carbon used and the time for which clearance is followed. The ultrastructural studies suggest an early constant rate of phagocytosis by Kupffer cells despite wide changes in dose of particles. At doses of 1 or 2 mg/100 g body weight of colloidal carbon the ultrastructural evidence shows that phagocytosis is the major early clearing process while at doses of 8 mg/100 g body weight and above the other processes are more important in the early clearance. Most clearance studies in the literature do not provide sufficient information to be certain that phagocytosis is the major process involved and such information can only be provided by detailed kinetic studies correlated with ultrastructural localisation of the particles. Many previous studies have used doses of colloidal carbon which invoke a major degree of the clearance processes other than phagocytosis and such studies are often based on a limited number of samples taken over a period when phagocytosis is not the only rate-controlling factor. Particle clearance studies should at least provide information concerning the possible role of platelets before the rates are considered to be measures of phagocytic function.

Animals↗
PubMed1975

Alveolar capillary basement membrane lesions in Goodpasture's syndrome and idiopathic pulmonary hemosiderosis.

An ultrastructural study of lung distinguised between lesions of the alveolar capillary basement membrane in a case of Good pasture's syndrome and in three cases of idiopathic pulmonary hemosiderosis. In Goodpasture's syndrome, diffuse vascular injury with wide endothelial gaps, diffusely fragmented basement membranes and an electron dense layer on the basement membrane was found. In idiopathic pulmonary hemosiderosis, focal ruptures of the basement membrane were associated with hydropic changes in pneumocytes and, although fibroblasts were not seen, collagen deposition occurred within the basement membrane. immunofluorescent studies failed to show deposition of immunoglobulins G (IgG), A (IgA), M (IgM) or C3 in the lung in either disease. The ultrastructural lesions appear to separate these clinically similar entities.

Adolescent↗
PubMed1975

The effect of a tubercle lipid adjuvant on the distribution of injected foreign red blood cells.

Increased localization occured of injected foreign red cells in the spleen and lungs of animals treated with a tubercle bacillary lipid adjuvant given intravenously. The distribution changes varied depending upon the time interval between injections of the adjuvant and the foreign red cells. These changes offer an explanation of the augmentation of haemolysins and haemagglutinins previously shown for the lipid.

Adjuvants, Immunologic↗
PubMed1973

The mechanism of renal glomerular capillary retention of carbon in disseminated intravascular coagulation.

In rabbits, when renal glomerular capillary thrombosis was induced by an infusion of thrombin, injected colloidal carbon particles localized within glomeruli. When administered after the thrombin had been infused, carbon was attached to the surface of fibrin deposits. Carbon also attached to platelets within capillaries containing fibrin, but not to leukocytes or endothelial cells. If administered simultaneously with thrombin, the carbon was incorporated into the developing mass of fibrin. These observations demonstrate that disseminated intravascular coagulation leads to the deposition of colloidal materials from the circulating blood in regions remote from reticuloendothelial organs, and illustrate a nonimmunologic mechanism whereby foreign particles and abnormal proteins might be trapped within the renal microcirculation.

Aminocaproates↗