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Biomedical subjects

A Jacobs

Publications and source records attributed to A Jacobs.

At least 361 records · Page 20Linked to original sources
PubMed1975

Accumulation of storage iron in patients treated for iron-deficiency anaemia.

The repletion of iron stores after treatment was studied in 38 patients with uncomplicated iron-deficiency anaemia. The serum ferritin concentration rose significantly when oral treatment was continued for two months after the attainment of a normal haemoglobin concentration. Patients treated with a total-dose infusion of iron dextran had thehighest final serum levels, which were significantly greater than in patients given Ferro-Gradumet. Oral ferrous sulphate was almost as effective as parenteral iron in producing iron stores.

Administration, Oral↗
PubMed1975

Serum ferritin in acute leukaemia at presentation and during remission.

In patients with acute myeloblastic leukaemia the mean serum ferritin concentration showed a twenty-five-fold increase compared with normal people, and in children with acute lymphoblastic leukaemia (A.L.L.) there was a thirteen-fold increase. The high concentration of circulating ferritin seemed to be related to increased synthesis by leukaemic cells. The return of serum concentrations to normal in A.L.L. patients after successful chemotherapy suggested that ferritin concentration may be a useful index of active disease and may help in prognosis.

Adolescent↗
PubMed1975

The characteristics of ferritin from human tissues, serum and blood cells.

1. The properties of ferritin in serum have been compared with those of ferritin from a number of tissues including blood cells. On anion-exchange chromatography with DEAE-Sephadex, the behaviour of human heart ferritin is different from that of liver, kidney or spleen ferritin. Reticulocyte ferritin appears to have similar characteristics to heart ferritin. 2. Serum ferritin from normal subjects and patients with various degrees of iron load, leukaemia or liver disease all have a much lower affinity for the anion-exchange column that any tissue ferritin, suggesting a difference in isoelectric point. The elution point of serum ferritin from patients with acute myeloblastic leukaemia is significantly different from normal. 3. Density gradient centrifugation in sucrose showed that ferritin in leucocyte extracts and partially purified ferritin from the serum of two patients with iron overload behaved as apoferritin rather than the iron-rich protein. 4. The results suggest that ferritin is modified during its entry into the plasma and that even in cases of iron overload the iron content of serum ferritin may be low. The findings are of importance in considering the origin of plasma ferritin, the clearance of ferritin from plasma and its role in iron metabolism.

Animals↗
PubMed1975

Ferrokinetics and erythropoiesis in man: the measurement of effective erythropoiesis, ineffective erythropoiesis and red cell lifespan using 59Fe.

Existing ferrokinetic methods do not provide a direct and quantitative measurement of effective and ineffective red cell production. A new method is described for calculating the daily uptake of iron by maturing red cells and the mean red cell lifespan. Ineffective erythropoiesis and non-erythroid iron turnover are also measured. The method involves standard laboratory techniques but the analysis requires access to a computer. The preliminary results suggest that it will be a clinically useful tool for the investigation of erythroid disorders.

Anemia↗
PubMed1975

Ferritin synthesis in lymphocytes, polymorphs and monocytes.

A rapid two-stage method has been devised for the separation of different leucocyte populations from human blood. Different cell types can be obtained in an undamaged state and with little contamination. Ferritin and total protein synthesis has been determined by measuring [14C]leucine incorporation in culture media which contain varying amounts of added ferric iron or desferrioxamine. Both ferritin and total protein synthesis is greater in monocytes than in lymphocytes or polymorphs when the basal medium is used. Only monocytes show a consistent increase in ferritin production due to iron stimulation. Ferritin synthesis by monocytes, polymorphs and lymphocytes is inhibited in the presence of desferrioxamine.

Cell Separation↗
PubMed1975

Iron absorption in normal subjects and patients with idiopathic haemochromatosis: relationship with serum ferritin concentration.

In 52 normal subjects there was an inverse relationship between serum ferritin concentration and iron absorption. In 21 measurements in 15 patients with idiopathic haemochromatosis there was a similar inverse relationship but absorption was higher in relation to iron stores at all levels. Haemochromatotic patients with normal serum ferritin levels had abnormally high values for desferrioxamine chelatable iron and there was no correlation between chelatable iron and iron absorption.

Adult↗
PubMed1975

The effect of iron stores on iron absorption in the rat: the possible role of circulating ferritin.

Iron absorption in man is inversely related to body iron stores and serum ferritin concentration. A negative correlation between intestinal iron absorption and the amount of storage iron in the body has been confirmed in the rat and the hypothesis that absorption may be regulated through the mediation of ferritin has been tested. There was no difference in mucosal iron uptake or absorption between rats undergoing a jugular infusion of ferritin and those infused with saline despite a hundredfold difference in circulating ferritin concentration.

Animals↗
PubMed1975

The use of Chang cells cultured in vitro for the investigation of cellular iron metabolism.

Chang cells have been used as a stable model system for the study of cellular iron metabolism. Iron uptake and the stimulation of ferritin synthesis have been studied together with iron incorporation into the ferritin molecule. About 25-30% of the iron taken up by the cells is found in a soluble, non-haem, non-ferritin form which can be chelated by a number of compounds. Ferritin synthesis is inhibited by the presence of desferrioxamine but not by zinc ions.

Cell Line↗
PubMed1975

Iron metabolism, sickle cell disease, and response to cyanate.

In an attempt to understand the variability of the hematologic response to oral sodium cyanate, iron metabolism was studied in a group of 39 patients with sickel cell disease. Eleven of the 39 patients were found to have no stainable iron in the marrow despite the fact that patients with sickle cell disease are generally considered to have hemosiderosis. The mean per cent saturation and total iron-binding capacity were in the low-normal range in sickle cell patients whether or not stainable iron was present in the bone marrow aspirate. Serum ferritin concentrations, on the other hand, were found to be high in both groups (greater than 500 mu g/liter) when compared to controls (60 mu g/liter). The high serum ferritin levels denoted significant total-body iron deposition which may be unavailable for normal metabolic processes. One patient with no stainable iron in the bone marrow aspirate did respond to iron therapy alone with an increase in hemoglobin concentration. Serum ceruloplasmin levels were also found to be high in sickle cell disease patients. The ability to respond to oral cyanate therapy was correlated with the amount of stainable iron in the bone marrow aspirate. These studies emphasize the necessity of a reevaluation of iron metabolism in the pathophysiology and treatment of sickle cell disease.

Administration, Oral↗
PubMed1975

The effects of iron deficiency on rat liver enzymes.

The effect of iron deficiency on a number or iron containing enzymes in rat liver has been examined. In addition, 6-phosphogluconate dehydrogenase and glucose 6-phosphate dehydrogenase have been assayed. Of the mitochondrial electron transport reactions only succinate-cytochrome C reductase activity was decreased in iron deficient animals. Microsomal reductase enzymes associated with the NADPH-oxidase system were also markedly decreased although cytochrome P450 concentrations were unaffected. Both 6-phosphogluconate dehydrogenase and glucose 6-phosphate dehydrogenase were reduced in young iron deficient rats but the former had returned to control levels at the age of 14 weeks.

Age Factors↗