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Biomedical subjects

D M Flynn

Publications and source records attributed to D M Flynn.

At least 55 records · Page 3Linked to original sources
PubMed1979

Improvement in iron status and liver function in patients with transfusional iron overload with long-term subcutaneous desferrioxamine.

Subcutaneous desferrioxamine (2--4 g over 12 h) was administered 6 nights each week to 34 patients with transfusional iron overloads who continued to receive regular blood-transfusions. All 34 patients showed a fall in serum-ferritin after 5 to 12 months. In some patients serum-ferritin fell almost to normal. Liver function improved in all the patients, serum-aspartate-transaminase levels fell in all 17 patients tested, and liver-iron fell in 5 of 6 patients tested. These studies show that body-iron stores can be substantially reduced, to normal or near normal levels, by long-term subcutaneous desferrioxamine in patients with transfusional iron overload despite the need for continued blood-transfusion. They also show that removal of iron is accompanied by improved organ function.

Adolescent↗
PubMed1977

Outbreak of necrotising enterocolitis caused by Clostridium butyricum.

12 hospital-born babies had necrotising enterocolitis, of varying severity, within six weeks, 5 of them within ten days. The usually described predisposing causes were absent in most, though no baby was exclusively breast -fed. Evidence of the presence of Clostridium butyricum was found in the blood of 9 out of 10 babies examined. Cl. butyricum is probably a primary, not a secondary invader.

Clostridium↗
PubMed1977

Effect of dose, time, and ascorbate on iron excretion after subcutaneous desferrioxamine.

The effect of 12 and 24 h continuous subcutaneous infusion of desferrioxamine (D.F.) on urinary iron excretion was compared in 13 patients with beta-thalassaemia major and 1 with congenital sideroblastic anaemia, all of whom were receiving regular blood-transfusions. 750 mg D.F. given over a 12 h period, gave a mean total (30 h) iron excretion of 17-5 mg, which was not statistically different from the mean iron excretion of 21-5 mg when the same dose was delivered over 24 h. 1500 mg D.F. gave a mean urinary iron excretion of 28-1 mg with a 12 h infusion, which was significantly less than the mean iron excretion of 39-6 mg with 24 h infusion. The 1500 mg dose gave a significant increase in iron excretion compared with the 750 mg dose when given by either 12 h or 24 h infusion. 7 of 8 patients, given D.F. over a 12 h period, had increased iron excretion when the dose was increased from 750 to 2000 mg. When the dose was increased to 4000 mg, however, the effect on iron excretion was variable. On the other hand, ascorbic-acid therapy was invariably associated with increased iron excretion after subcutaneous D.F. In twelve studies at different dose levels of D.F., ascorbate therapy was associated with increased iron excretion ranging from 24 to 245%. It is concluded that in most patients with transfusional iron overload subcutaneous D.F over a 12 h period, at a dose ranging from 2 to 4 g daily with ascorbic-acid saturation, is at present the most satisfactory method of removing excess iron.

Administration, Oral↗
PubMed1976

Subcutaneous infusion and intramuscular injection of desferrioxamine in patients with transfusional iron overload.

The effects of intramuscular injection and subcutaneous infusion of desferrioxamine (D.F.) on urinary iron excretion were compared in eleven patients with thalassaemia major and one with congenital sideroblastic anaemia who were being maintained on regular blood-transfusions. Total (48-hour) urinary iron excretion ranged from 3-3 to 40-3 mg (mean 16-3 mg) in nine patients who received 750 mg D.F. intramuscularly before transfusion and from 3-9 to 32-3 mg (mean 11-9 mg) in ten patients who received D.F. by the same route after transfusion. In all 9 patients studied before transfusion, continuous subcutaneous infusion of 750 mg D.F. over 24 hours increased iron excretion by 61-5 to 135-8% (mean 101+/-25-4 S.D.%) compared with intramuscular injection of a similar dose. In the 10 patients studied after transfusion, the iron excretion produced by continuous subcutaneous infusion was from 18-9 to 213% (mean 128+/-74-3%) more than that produced by a single intramuscular injection of D.F. When the subcutaneous dose over 24 hours was increased to 1500 mg in six patients, 48-hour iron excretion ranged from 29-2 to 81-2 mg (mean 52-4 mg) and was increased by 80-2--794% (mean 429%) compared with the excretion when 750 mg was given by intramuscular injection. It is concluded that continuous subcutaneous infusion of D.F. produces more iron excretion in patients with iron overload than intramuscular injection. Providing a suitable portable pump can be carried by the patients, continuous subcutaneous infusion of desferrioxamine may prove a valuable means of preventing or treating iron overload in anaemic patients maintained on regular transfusions.

Adolescent↗
PubMed1976

Hormonal changes in thalassaemia major.

Patients with severe thalassaemia major suffer endocrine and other abnormalities before their eventual death from iron overload due to repeated blood transfusions. The endocrine status of 31 thalassaemic patients aged 2-5 to 23 years was investigated. Exact data were available on the rate and duration of blood transfusion in all of them and in many the liver iron concentration was also known. Although the patients were euthyroid, the mean serum thyroxine level was significantly lower, and the mean thyrotrophic hormone level significantly higher, compared with the values found in normal children. Forty oral glucose tolerance tests with simultaneous insulin levels were performed in 19 children, of whom 5 developed symptomatic diabetes and one had impaired tolerance. Previous tests on all 6 patients were available and some showed raised insulin levels possibly due to insulin resistance. 2 patients had clinical hypoparathyroidism and are described. The parathyroid hormone levels determined by radioimmunoassay in 25 patients were below the mean for the age group in all and outside the reference range in 16. Nonfasting plasma calcium levels were not reduced. Puberty was delayed in some patients. Concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) measured in urine from 7 girls and 5 boys showed considerable variation. In the boys there was an overall tendency for FSH and LH excretion to be low with regard to age, but with respect to puberty rating FSH exretions were normal or low and LH normal or raised. The girls showed a tendency for LH but not FSH excretion to be raised in relation to puberty rating. The severity of the endocrine changes was related to the degree of iron loading and is discussed in relation to previous work in which the iron loading has rarely been accurately indicated nor parathyroid status assessed.

Adolescent↗
PubMed1975

Transfusional iron overload: the relationship between tissue iron concentration and hepatic fibrosis in thalassaemia.

The interrelationships between liver iron concentration, the duration of iron-loading, and hepatic fibrosis, assessed morphometrically, have been studied in 32 specimens of liver obtained from 19 heavily transfused patients with thalassaemia major whose age ranged from 4 to 19 yr. Similar observations were made in a matched group of thalassaemic patients treated with long-term chelation therapy. The degree of liver damage ranged from very slight increase in fibrous tissue to severe fibrosis and cirrhosis. The severity of the fibrosis was closely correlated both with liver iron concentration and with age. While the relationship between fibrosis and age was linear, both the severity and the rate of fibrosis were exponentially related to liver iron concentration, damage accelerating as liver iron concentration exceeded 3 per cent, dry weight. By producing a modest but significant reduction in liver iron concentration chelation therapy resulted in a disproportionate but predictable retardation in the progression of the fibrosis. The factors affecting the distribution of iron between parenchymal and reticuloendothelial cells were also examined. In general stainable iron was uniformly distributed between parenchymal and reticuloendothelial cells from the early stages of iron-loading. Parenchymal siderosis was relatively heavier in splenectomised patients and in patients with liver iron concentrations above 3 per cent, dry weight than in non-splenectomised patients or patients with liver iron levels of less than 3 per cent, dry weight, but this did not affect the severity of the fibrosis. The relevance of these findings to the traditional concepts of the pathology of transfusional siderosis is discussed.

Adolescent↗
PubMed1974

Long-term chelation therapy in thalassaemia major: effect on liver iron concentration, liver histology, and clinical progress.

A prospective trial of continuous chelation therapy in children with homozygous thalassaemia on a high transfusion regimen was started in April 1966. The effect of treatment on iron concentration in the liver and on hepatic histology was examined in 49 biopsy specimens obtained from nine chelator-treated patients and nine control patients between April 1966 and April 1973.Chelation therapy was associated with a significant reduction in liver iron concentration, and by the end of the trial the values for the two groups showed no overlap. A similar difference was seen in the amount of hepatic fibrosis, which showed little or no change in the chelator-treated patients but was progressive in the controls.No major clinical differences were seen, probably because both groups included several older children who were heavily loaded with iron at the start of the trial. Among the younger patients, however, puberty was delayed in four of five controls but in only one of four chelator-treated children. Prepubertal growth rate was significantly greater in the chelator-treated patients than in the controls.

Biopsy↗
PubMed1974

Serum ferritin in children with thalassaemia regularly transfused.

A controlled trial of continuous chelation therapy in regularly transfused children with homozygous beta-thalassaemia has been in progress at the Hospital for Sick Children since April 1966. In the sixth and seventh years of the trial the effect of this treatment on iron overload has been assessed by estimating serum ferritin levels and liver iron concentrations in both chelator-treated and control groups. When compared with non-chelated controls, results of both these estimations were invariably lower in the chelated group. However, all the results in both groups were very high, and fell within the ranges observed in untreated idiopathic haemochromatosis. A close correlation was found between serum ferritin levels and liver iron concentrations in these children, indicating that serum ferritin is a valuable alternative to liver iron concentration in the assessment of visceral iron overload, even when massive tissue siderosis is present.

Blood Transfusion↗
PubMed1972

A comparison of descending arotic and "arterialized" capillary blood in the sick newborn.

Comparison was made of 53 "arterialized" capillary (heel prick) samples with descending aortic blood in 26 babies, of whom 24 were less than one week old and 18 had R.D.S."Arterialized" capillary blood is an accurate and practical means of assessing aortic blood pH and Pco(2) over a range of 6.69 to 7.54 and 18 to 94 mm. Hg respectively."Arterialized" capillary sampling is a reliable means of assessing descending aortic Po(2) when the "arterialized" capillary value is less than 60 mm. Hg.When higher than 60 mm. Hg the "arterialized" capillary oxygen tension may be considerably less than that of the blood in the descending aorta, hence the "arterialized" capillary blood oxygen tension method is unreliable in estimating systemic oxygenation when the descending aortic oxygen tension is more than 60 mm. Hg.

Asphyxia Neonatorum↗