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Biomedical subjects

S R Lynch

Publications and source records attributed to S R Lynch.

At least 73 records · Page 4Linked to original sources

Pure red cell aplasia.

The presentation and clinical course of pure red cell aplasia in 5 patients are described. In 3 of them no concomitant diseases were present, in 1 the condition was associated with the presence of a thymoma, and the remaining patient was suffering from a lymphocytic lymphoma. Pregnancy led to a recurrence of the disorder in 2 patients. The fact that 4 of the patients exhibited unequivocal evidence of other auto-immune disturbances adds further support to the concept that pure red cell aplasia itself has an auto-immune basis.

Adolescent↗

Acute blastic transformation in patients with chronic granulocytic leukaemia and myelofibrosis.

A retrospective study of 21 patients with acute transformation of chronic granulocytic leukaemia (CGL) and myelofibrosis was undertaken. The patients were divided into 3 groups according to whether transformation had occurred in pre-existing CGL (11 patients), myelofibrosis (6 patients) or in patients who presented with acute leukaemia and significant marrow fibrosis--acute myelofibrosis (4 patients). In an attempt to investigate some recent reports that during the acute blastic crisis there is conversion to the haemopoietic stem cell, the morphology of the blast cell and the response to therapy were assessed. The blast cell morphology was reviewed in 17 of the 21 patients studied. Three patients had blast cells which morphologically resembled lymphoblasts. The mortality in these patients was similar to that in patients in whom the blast cell morphology was myeloblastic. The response to treatment in the acute phase was poor. However, some patients who received therapy with thioguanine, daunorubicin, cytosine arabinoside, methotrexate, prednisone, cyclophosphamide and vincristine (TRAMPCO) appeared to do better. in most patients, splenectomy was performed for advanced diseases. Acute blastic transformation supervened within 4 months in 3 of 4 patients with CGL who underwent splenectomy. In 3 of 5 patients with myelofibrosis, splenectomy was followed by an increase of primitive cells in the peripheral blood and rapid liver enlargement. Although they had improved symptomatically the patients died within 10 months of the splenectomy. The indications for and timing of splenectomy remain controversial.

Acute Disease↗

Factor VIII and factor-VIII-related antigen in multiple myelomatosis and related conditions.

Factor VIII and factor-VIII-related antigen (FVIIIRA) were estimated in 19 patients with paraproteinaemia. The FVIIIRA levels were above the normal range in 12 cases with II of these showing an abnormal FVIII/FVIIIRA ratio. The patients could be subdivied into three groups according to their FVIIIRA levels: normal levels, levels greater than normal but less than 200%, greater than 200%. This subdivision correlated with the degree of bone involvement as assessed by radiological skeletal survey.

Adult↗

Patterns of food iron absorption in iron-deficient white and indian subjects and in venesected haemochromatotic patients.

The absorption of radioactive iron from a solution of ferrous ascorbate, and from a standard meal containing intrinsically labelled haemoglobin and wheat, was measured in 12 Indian housewives, 18 white hospital patients and 12 subjects with idiopathic haemochromatosis. Eight of the latter had been fully treated by multiple venesections, so that their serum ferritin concentrations were below 25 mug/1. Since the serum ferritin concentrations of the housewives and the hospital patients were comparable, their body iron stores were considered to be depleted to a similar degree. There were no significant differences between the absorptions of ferrous ascorbate or of the haem iron in the standard meal by each group, but the housewives and the hospital patients absorbed significantly less of the non-haem food iron. The mean non-haem food iron absorptions were 36.4%, 5.8% and 18.9% for the treated haemochromatotic subjects, the Indian housewives and the white hospital patients respectively. The discrepancies between the absorptions of the different forms of food iron were highlighted by calculating the ratios between them. The mean non-haem: haem food iron absorption ratio for the group of treated haemochromatotic subjects was 0.98, and for the Indian housewives only 0.18. The white hospital patients did not form a homogenous population: the ratios of the five males and three of the females were greater than 1.0, whereas those of the remaining 10 females were less than 0.5. The results of this study suggest that mal-absorption of non-haem iron from a meal containing bread, presumably due to a defect at the luminal level, may be an important factor in the pathogenesis of iron deficiency in some subjects. The abnormality appears to be particularly prevalent among Indian women living in Durban.

Adolescent↗

Serum beta-lipoprotein and other specific protein concentrations in patients with immunocytoma.

Serum beta-lipoprotein and other specific protein concentrations were measured in 56 patients suffering from multiple myelomatosis, "benign" paraproteinaemia or Waldenström's macroglobulinaemia and in 56 control subjects. The mean level of B-lipoprotein in untreated patients with multiple myelomatosis and macroglobulinaemia was significantly lower than that of the controls. Patients who responded to chemotherapy showed a rapid return to normal of the beta-lipoprotein concentration, while the level remained unchanged in most of those who did not.

Aged↗

Studies on the fortification of cane sugar with iron and ascorbic acid.

1. The feasibility of improving iron nutrition by fortifying cane sugar with Fe and ascorbic acid was studied. 2. It was found to be possible to add a number of Fe salts together with ascorbic acid to sugar without affecting its appearance or storage properties. 3. The absorption of Fe from fortified sugar eaten with maize-meal porridge or made into jam or biscuits was measured in ninety-four volunteer multiparous Indian women using the 59-Fe erythrocyte utlization method. 4. The absorption of Fe from sugar fortified with ascorbic acid and ferrous sulphate and eaten with maize-meal porridge was increased about twofold in the ratio, ascorbic acid:Fe was 10:1 by weight. If the ratio was increased to 20:2, Fe absorption was increased a further threefold. 5. Sugar fortified with soluble Fe salts, including FeSO4.7H2O, discoloured both tea and coffee; sugar fortified with ferric orthophosphate did not have this effect. 6. Fe from FePO4.H2O was poorly absorbed when added with sugar to maize-meal porridge, and also when added with adequate quantities of ascorbic acid. This form of Fe was absorbed much less well than was the intrinsic Fe present in the maize. 7. When sugar fortified with FePO4.H2O and ascorbic acid was added to maize-meal porridge before cooling or was made into jam there was a several-fold increase in the amount of Fe absorbed.

Adult↗

The effect of tea on iron absorption.

The effect of tea on iron absorption was studied in human volunteers. Absorption from solutions of FeCl3 and FeSO4, bread, a meal of rice with potato and onion soup, and uncooked haemoglobin was inhibited whether ascorbic acid was present or not. No inhibition was noted if the haemoglobin was cooked. The effect on the absorption of non-haem iron was ascribed to the formation of insoluble iron tannate complexes. Drinking tannin-containing beverages such as tea with meals may contribute to the pathogenesis of iron deficiency if the diet consists largely of vegetable foodstuffs.

Adult↗

The mechanism of the inhibition of iron absorption by tea.

Previous human studies have shown that drinking tea during meals significantly inhibits the absorption of both food iron and medicinal iron. This study provides evidence from experiments with rats that the tannins in the tea are responsible for the inhibition, probably by forming non-absorbable complexes with the iron within the intestinal lumen. The molar ratio of tannin: iron is dependent on the pH, being 1:1 at pH 2,0 2:1 at pH 5,5 and 3:1 at pH 8,0. Since tannins are present in many vegetable foods the formation of such complexes may be a factor in the poor availability for absorption of much food iron.

Chemical Phenomena↗