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The sideroblastic anaemias
ABSTRACTS OF A N N U A L S C I E N T I F I C M E E T I N G
1968
157
families. These family studies provided evidence to support a dominant mode of inheritance, with a variable expressivity of the trait causing a number of individuals to show no clinical signs of photosensitivity and only mild biochemical abnormalities, namely, small increases in erythrocyte or faecal prophyrin levels. Some of the many unanswered questions regarding erythropoietic protoporphyria were discussed, including the nature of the metabolic defect. It is likely that the accumulation of protoporphyrin is due to overproduction rather than to a block in the pathway of haem synthesis. Proposed studies in this field were outlined. The mechanism by which overproduction could arise from a constitutive operator mutation via increased enzyme synthesis was explained. The possible mechanism of production of the photosensitive skin reaction in erythropoietic protoporphyria was also discussed. FACTORS INFLUENCING THE SIGNIFICANCE OF ALCOHOL CONCENTRATIONS I N AUTOPSY BLOOD SAMPLES
PLUECKHAHN, V. The Geelong Hospital, Victoria
Certain basic information must be known about any autopsy blood sample before an assessment can be made of the significance of any alcohol concentration present. Changes may occur in the alcohol concentration of blood samples during storage and these changes and their significancehave been studied carefully in samples taken from the living. Similar studies concerning blood samples taken at autopsy are few and incomplete. The author has shown that significant blood-alcohol concentrations may be generated in autopsy blood samples during their storage at room temperature under conditions generally acceptable as satisfactory for their storage. A QUANTITATIVE DETERMINATION OF SPLENIC IRON CONTENT I N THALASSAEMIA MAJOR
ANDERSON, G.
Royal Children’s Hospital, Melbourne, Victoria
Using an atomic absorption analyser, a quantitative estimation was performed of the iron content of spleens removed from nine children with thalassaemia major, five with hereditary spherocytosis, one with sickle-cell anaemia, three with ITP and one with asthma. When expressed as mg./100 g. wet tissue the concentration of iron in the ITP spleens proved to be compatible with the results quoted by previous observers for normal adult spleens, but for the hereditary spherocytosis and sickle-cell anaemia spleens values were two to four times the normal and for the thalassaemic spleens three to ten times the normal, the total mass of iron in the largest thalassaemic spleen being more than 100 times normal. By comparing the total mass of iron given in the form of blood transfusions to the thalassaemic children with the mass of iron in their spleens, it was shown that the spleen plays a relatively small role as an organ of iron storage in this disease. THE SI D EROB LASTlC ANAEMIAS
RUSH,B.
St. Vincent’s Hospital, Melbourne, Victoria
The definition and classification of the sideroblastic anaemias was discussed. Clinical and laboratory details of three patients were given, each patient representing one aspect of these anaemias. The first patient passed from a phase of refractory anaemia with bone marrow sideroblastosis to frank acute leukaemia. The second patient’s sideroblastic anaemia was associated with lead poisoning from an unusual source. The third patient’s sideroblastic anaemia was responsive to pyridoxine. Possible abnormalities in haem synthesis leading to marrow sideroblast formation were mentioned, but it was concluded that insufficient evidence was yet available to justify any firm statement concerning the pathogenesis of the sideroblastic anaemias. A RAPID PLASMINOGEN ASSAY METHOD
HANDLEY, D. A. Institute of Medical and Veterinary Science, Adelaide, South Australia The method is based on the rate of lysis of human fibrinogen (adsorbed with charcoal to reduce plasminogen content) by streptokinase-activated plasminogen. Inhibitors of plasminogen activation are excluded
1968
157
families. These family studies provided evidence to support a dominant mode of inheritance, with a variable expressivity of the trait causing a number of individuals to show no clinical signs of photosensitivity and only mild biochemical abnormalities, namely, small increases in erythrocyte or faecal prophyrin levels. Some of the many unanswered questions regarding erythropoietic protoporphyria were discussed, including the nature of the metabolic defect. It is likely that the accumulation of protoporphyrin is due to overproduction rather than to a block in the pathway of haem synthesis. Proposed studies in this field were outlined. The mechanism by which overproduction could arise from a constitutive operator mutation via increased enzyme synthesis was explained. The possible mechanism of production of the photosensitive skin reaction in erythropoietic protoporphyria was also discussed. FACTORS INFLUENCING THE SIGNIFICANCE OF ALCOHOL CONCENTRATIONS I N AUTOPSY BLOOD SAMPLES
PLUECKHAHN, V. The Geelong Hospital, Victoria
Certain basic information must be known about any autopsy blood sample before an assessment can be made of the significance of any alcohol concentration present. Changes may occur in the alcohol concentration of blood samples during storage and these changes and their significancehave been studied carefully in samples taken from the living. Similar studies concerning blood samples taken at autopsy are few and incomplete. The author has shown that significant blood-alcohol concentrations may be generated in autopsy blood samples during their storage at room temperature under conditions generally acceptable as satisfactory for their storage. A QUANTITATIVE DETERMINATION OF SPLENIC IRON CONTENT I N THALASSAEMIA MAJOR
ANDERSON, G.
Royal Children’s Hospital, Melbourne, Victoria
Using an atomic absorption analyser, a quantitative estimation was performed of the iron content of spleens removed from nine children with thalassaemia major, five with hereditary spherocytosis, one with sickle-cell anaemia, three with ITP and one with asthma. When expressed as mg./100 g. wet tissue the concentration of iron in the ITP spleens proved to be compatible with the results quoted by previous observers for normal adult spleens, but for the hereditary spherocytosis and sickle-cell anaemia spleens values were two to four times the normal and for the thalassaemic spleens three to ten times the normal, the total mass of iron in the largest thalassaemic spleen being more than 100 times normal. By comparing the total mass of iron given in the form of blood transfusions to the thalassaemic children with the mass of iron in their spleens, it was shown that the spleen plays a relatively small role as an organ of iron storage in this disease. THE SI D EROB LASTlC ANAEMIAS
RUSH,B.
St. Vincent’s Hospital, Melbourne, Victoria
The definition and classification of the sideroblastic anaemias was discussed. Clinical and laboratory details of three patients were given, each patient representing one aspect of these anaemias. The first patient passed from a phase of refractory anaemia with bone marrow sideroblastosis to frank acute leukaemia. The second patient’s sideroblastic anaemia was associated with lead poisoning from an unusual source. The third patient’s sideroblastic anaemia was responsive to pyridoxine. Possible abnormalities in haem synthesis leading to marrow sideroblast formation were mentioned, but it was concluded that insufficient evidence was yet available to justify any firm statement concerning the pathogenesis of the sideroblastic anaemias. A RAPID PLASMINOGEN ASSAY METHOD
HANDLEY, D. A. Institute of Medical and Veterinary Science, Adelaide, South Australia The method is based on the rate of lysis of human fibrinogen (adsorbed with charcoal to reduce plasminogen content) by streptokinase-activated plasminogen. Inhibitors of plasminogen activation are excluded