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Biomedical subjects

J E Pettit

Publications and source records attributed to J E Pettit.

10 recordsLinked to original sources
PubMed1979

Transitional myeloproliferative disorder.

Eleven patients have been observed with clinical features of both polycythaemia vera and myelofibrosis. Detailed follow-up and repeated haematological and isotopic investigations, including the assessment of erythropoietic distribution by 52Fe scanning, over a 10 year period, have indicated that patients who initially present with this syndrome may remain in a steady state for several years and that this transitional syndrome does not necessarily imply an active or irreversible transformation into classical myelofibrosis. Therapy with iron, folic acid, alkylating agents, splenectomy or splenic irradiation may reduce the extramedullary component of myeloproliferation and allow occasional patients to revert to more classical polycythaemia vera. Radioactive phosphorus (32P) therapy may be inappropriate in polycythaemic patients with dominant extramedullary erythropoiesis, as this form of therapy has a preferential medullary action and may selectively encourage extramedullary myeloproliferation.

Adult↗
PubMed1978

Polycythaemia vera-transformation to myelofibrosis and subsequent reversal.

A woman aged 67 who developed polycythaemia vera 21 years ago has been seen regularly since the diagnosis was first made. She was treated initially with pyrimethamine and then for 10 years by repeated venesections. After a 4 year period when her myeloproliferative disease was considered to be transitional a complete transformation to myelofibrosis occurred. She was treated by splenic irradiation and later with alkylating agents in an attempt to give her symptomatic relief from massive splenomegaly. Repeated and massive haemorrhage from gastro-oesophageal varices was treated initially by percutaneous transhepatic sclerosis of the gastro-oesophageal collateral vessels. A subsequent dacron mesocaval jump graft operation was successful in preventing further haematemesis and melaena. During the last year transformation back to polycythaemia vera has occurred. The evolution of her myeloproliferative disease has been fully documented by detailed blood counting, bone marrow aspirates and trephine biopsies, blood volume studies and other radioisotope investigations including the quantitation of functional erythropoietic tissue with 52Fe.

Aged↗
PubMed1978

Hepatic iron clearance from serum in treated hemochromatosis.

Hepatic iron uptake from transferrin has been studied in 7 patients with treated hemochromatosis. When compared with a control group with similar serum iron and transferrin saturation the hemochromatotics had a significantly higher 4-hr iron uptake value. Uptake in the precirrhotic and cirrhotic hemochromatotics was not significantly different, suggesting the existence of a cellular abnormality of hepatic iron metabolism in this disease. The results provide an explanation for the development of siderosis in some patients with idiopathic hemochromatosis and a normal serum iron concentration.

Adult↗
PubMed1977

The measurement of spleen perfusion in man: a non-invasive method using the ratio between Rubidium-81 and its decay product Krypton-81m.

A non-invasive method has been developed for measuring spleen perfusion in man. This involves recording the gamma-ray energy spectra over the spleen following the localisation of Rubidium-81 within the organ by injecting intravenously labelled heat denatured red cells. The spectra are analysed to provide the ratio of Rubidium-81 to its radioactive decay product Krypton-81 m. This ratio is dependent on the rate of perfusion through the organ. The difficulties encountered in applying this steady state method for monitoring tissue perfusion are illustrated and practical means for their solution presented. The results of applying this method to patients with various splenic disorders are presented and compared with those obtained by other workers using different monitoring techniques.

Humans↗
PubMed1977

Adult Niemann-Pick disease: its relationship to the syndrome of the sea-blue histiocyte.

Three unrelated female patients with adult Niemann-Pick disease are described. All the patients had reduced coagulation factors and involvement of the marrow, liver, spleen and lungs. Two patients were shown to have abnormal platelet function; two patients also had pingueculas and a late onset of a menarche. Foam cells and sea-blue histiocytes were seen in the marrow and livers in all three patients, in the spleen in two patients in the lymph nodes in one patient. The clinical presentation, the histologic appearance, the histochemical staining reactions, the lipid analysis and the ultrastructure were all consistent with a diagnosis of adult Niemann-Pick disease. On the basis of these observations, it is clear that adult Niemann-Pick disease is a cause of the syndrome of the sea-blue histiocyte. The existence of the syndrome of the sea-blue histiocyte as a separate entity is also questioned.

Adolescent↗
PubMed1977

Spleen function.

Explore the source record for details and available documents.

Atrophy↗
PubMed1976

Streptokinase in central retinal vein occlusion: a controlled clinical trial.

Forty patients with central retinal vein occlusion were allocated at random either to a treatment group given streptokinase followed by anticoagulatns or to a control group given no specific treatment. The two groups, which were each of 20 patients, were broadly similar in respect of clinical and laboratory values and similar in their initial visual acuity. At follow-up ("final" vision) the visual acuity in the treated group was significantly better than in the untreated group. Only one treated patient developed thrombotic glaucoma compared with four controls. Streptokinase may, however, have been responsible for vitreous haemorrhage (and permanent loss of vision) in three patients and hence probably has only a limited role in the treatment of central retinal vein occlusion.

Adult↗
PubMed1976

Quantitative studies of splenic erythropoiesis in polycythaemia vera and myelofibrosis.

A quantitative scanning method employing cyclotron-produced 52Fe has been developed to assess splenic erythropoiesis in patients with myeloproliferative disorders. In 12 patients with myelofibrosis splenic uptake of 52Fe was from 5.0% to 48% of the injected dose. Although a single patient with classical polycythaemia vera had a minor uptake of 2.8% of six other patients with this diagnosis showed no concentration of isotope in the splenic area. The fraction of 52Fe in the spleen of four patients with 'transitional' myeloproliferative disorders characterized by a high red cell mass, hypercellular bone marrow and a leucoerythroblastic blood film varied from 5% to 41%. No clear relationship was noted between the degree of splenic erythropoiesis as defined by this technique and the level of haemoglobin, the degree of splenomegaly, the effectiveness of erythropoiesis of traditional 59Fe surface counting. If splenectomy is considered in patients with myelofibrosis splenic 52Fe quantitation will provide more precise data on the contribution of splenic erythropoiesis than 59Fe surface counting alone.

Erythropoiesis↗