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Biomedical subjects

J R Mann

Publications and source records attributed to J R Mann.

At least 163 records · Page 9Linked to original sources
PubMed1975

Anaemic crisis in sickle cell disease.

Sixteen episodes of acute anaemia necessitating urgent blood transfusion have been investigated in 13 children with sickle cell anaemia. In five out of seven episodes there was evidence of increased haemolysis while in 10 out of 16 episodes a profound fall in reticulocyte count indicated marrow erythroid cell failure. Cold agglutinins active at room temperature were detected in 13 episodes, and anti-I specificity was demonstrated in 11. Warmed blood of homologous ABO and Rhesus groups was administered without complication despite difficulty with cross-matching. The exacerbation of anaemia was not due to folate lack, glucose-6-phosphate dehydrogenase deficiency or splenic sequestration, and an infectious agent appeared responsible. The degree of anaemia in homozygous sickle cell disease is usually constant during asymptomatic periods. An episode of sudden profound anaemia (anaemic crisis) may, however, result from marrow hypoplasia, an exacerbation of haemolysis, splenic sequestration, or folate deficiency.

Acute Disease↗
PubMed1974

Coagulation fibrinolysis in sickle-cell disease.

A study of fibrinolytic activity in sickle-cell patients during asymptomatic periods has shown a normal fibrinolytic response to exercise and local heat to the arm. During vasoocclusive crises there was no significant decrease in fibrinolytic activity. These results contrast with earlier reports of decreased fibrinolysis during crisis and a suggestion that fibrinolytic activators might be of value in preventing vasoocclusive episodes. Patients in painful crisis showed a significant rise in fibrinogen concentration and fall in platelet count. The former may contribute to localized vascular sludging by increasing whole-blood viscosity, while the latter probably results from local trapping of platelets in areas of sickling or from subsequent splenic sequestration of damaged platelets. There was no evidence of disseminated, as opposed to localized, intravascular coagulation during crisis.

Adolescent↗
PubMed1971

Lysosomal enzyme cytochemistry in acute leukaemia.

A cytochemical study of the lysosomal enzyme beta-glucuronidase in 60 cases of acute leukaemia has shown a qualitative difference in the cytoplasmic distribution of the enzyme between blast cells of the lymphoid and myeloid cell series. This difference provides a useful additional method for cytochemical classification of cell type and is superior in this respect to the other lysosomal enzymes studied (aryl sulphatase and acid phosphatase). The beta-glucuronidase reaction is recommended in those cases of acute leukaemia in which the periodic acid-Schiff reaction is negative or equivocal.

Acid Phosphatase↗