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Biomedical subjects

J M Rattenbury

Publications and source records attributed to J M Rattenbury.

At least 19 recordsLinked to original sources
PubMed1992

Homozygous acute intermittent porphyria: compound heterozygosity for adjacent base transitions in the same codon of the porphobilinogen deaminase gene.

A sister and brother with severe porphobilinogen (PBG) deaminase deficiency are described. Each of their parents carries a different mutation for acute intermittent porphyria and the children are homozygous for the PBG-deaminase deficiency that causes this disorder. Both are compound heterozygotes for adjacent base transitions in the same codon in exon 10 of the PBG deaminase gene.

Base Sequence↗
PubMed1990

D(+)-glyceric aciduria: etiology and clinical consequences.

A family comprising mother, father, and five children is described. Four of the children were found to excrete massive amounts of D(+)-glyceric acid in their urine. This was verified by gas chromatography-mass spectrometry and the configuration determined by capillary gas chromatography of O-acetylated menthyl esters. The excretion ranged from 10.8 to 19.9 mmol/24 h. The remaining child and the parents showed no evidence of this unusual metabolite. The virtual absence of clinical manifestations in this family was particularly interesting. Only two of the children showed any clinical abnormality and this was limited to mild microcephaly and speech delay; the other two children found to excrete large amounts of D(+)-glycerate were healthy and developmentally normal at 7 y and 9 y of age. There was a marked increase in the excretion rate of D(+)-glycerate in response to both oral fructose and serine loading. These results are consistent with a deficiency of D(+)-glycerate kinase and indicate the potentially benign nature of this disorder.

Administration, Oral↗
PubMed1990

Establishment of an external quality-assessment scheme for amino acid analyses: results from assays of samples distributed during two years.

Ten different samples of lyophilized plasma and two of liquid urine were distributed during two years to 26 laboratories performing quantitative amino acid analyses in a scheme designed to provide external quality assessment. After each distribution, statistical summaries and performance scores based on delta standard deviations and percentage biases from the all-laboratory trimmed means were returned to participants, who also received annual performance summaries based on their accumulated results. Coefficients of variation calculated from returns across all the samples ranged from 13% for glycine to 65% for methionine. Automated ion-exchange amino acid analyzers with ninhydrin detection appeared to perform better than other methods, although there was no clearly superior method and no model of analyzer clearly outperformed the others. These exercises demonstrate that there is room for improvement in the performance of quantitative amino acid analyses and that individual expertise may be more important in maintaining good performance than the choice of method or analyzer.

Amino Acids↗
PubMed1989

Identification of the cause of separation (creaming) of lipid emulsions in intravenous infusion.

Over a 2-month period, white deposits were found in infusion sets delivering parenteral nutrition mixtures that included a lipid emulsion. When components of the infusion were mixed in the laboratory, separation (creaming) of the emulsion could be demonstrated, and this enabled us to predict the concentrations of the prescribed infusates that were likely to cream. Further investigations showed that creaming occurred when the lipid emulsion was mixed with heparin and calcium ions at concentrations above 1 U/ml and 1 mumol/ml, respectively.

Calcium↗
PubMed1989

Urinary excretion of 3-methylhistidine, creatinine and total nitrogen by Kenyan children during acute measles and after recovery.

The urinary excretion of 3-methylhistidine (3MH), creatinine and total nitrogen was measured during the course of energy balance studies on 20 black Kenyan children. Studies were carried out over 24 h during an acute attack of measles with a second (control) study after recovery, and complete urinary collections were obtained on 14 ill and 18 recovered children. The nutritional status was assessed by anthropometry, and energy intake was determined by duplicate diet analysis. Twelve out of 13 acutely ill and 6 out of 17 recovered children were in negative energy balance. No effect on the rate of excretion of 3MH or of creatinine attributable to differences in nutritional status, of energy intake or to infection was observed. The linear relationship between the excretion rate of all three metabolites and body weight which was observed in recovered children was absent during acute infection. Nitrogen excretion was correlated (P less than 0.05) with the level of energy intake. The linear relationship between the rate of excretion of 3MH and creatinine and of 3MH and nitrogen was significantly closer in recovered than in ill children. The simultaneous effects of infection, underfeeding (and oliguria) on the rate of excretion of protein metabolites may be complex and contradictory. Our results suggest that the excretion of 3MH, creatinine and nitrogen is sustained during infection accompanied by negative energy balance. Disruption during infection of the relationship between the excretion of all three metabolites and body weight, and between 3MH and the other two metabolites suggests perturbation in protein metabolism at this time.

Child, Preschool↗
PubMed1988

Transient neonatal galactosaemia.

A 4 week old infant who failed to thrive was found to have galactose in his urine. Plasma galactose concentration was grossly raised (4.48 mmol/l; reference range less than 0.24 mmol/l) but red cell transferase and epimerase activities were normal. He improved when dietary lactose was excluded. Clinical and biochemical tolerance to galactose was evident by 7 months of age.

Galactose↗
PubMed1988

Acceptance of domiciliary theophylline monitoring using dried blood spots.

Filter paper cards incorporating dried blood spots for the measurement of theophylline concentrations were returned by 62 out of 100 asthmatic children sent kits with instructions for their collection. Analysis of the blood spots showed that 37 (61%) of the children who returned them had less than therapeutic blood theophylline concentrations, in 21 (34%) they were therapeutic, and in three (5%) they were potentially toxic. The results indicate that most asthmatic children would comply with requests for home monitoring of theophylline concentrations, and that only one third of children receiving theophylline achieved blood concentrations and that only one third of children receiving theophylline achieved blood concentrations within the therapeutic range.

Adolescent↗
PubMed1988

Screening tests for glycosaminoglycans in urine: experience from regional interlaboratory surveys.

Three urine samples were distributed to laboratories in the Trent and Yorkshire regions to assess their ability to detect glycosaminoglycans. Satisfactory results were obtained for samples from patients with Hunter's and Morquio's diseases but six of 14 laboratories reporting a result for a Sanfilippo sample missed the abnormality. Replies to a subsequent questionnaire showed that unsuccessful laboratories were not using recommended screening methods, that they lacked experience in testing for these diseases, and that rationalisation of such screening services may be indicated.

Child↗
PubMed1988

Measurement of theophylline in dried blood spots by spectrophotometric enzyme immunoassay.

A widely-used enzyme immunoassay for the measurement of theophylline in plasma (EMIT) has been adapted for use with dried blood spots. Potential interference from haemoglobin in eluates of the spots was avoided by autoclaving them prior to analysis. The method was investigated in terms of the recovery of theophylline added to samples, precision, and the correlation of results in DBS with those in plasma samples. The recoveries of some other drugs from eluates of autoclaved DBS were also investigated.

Adolescent↗
PubMed1987

Clodronate in the medical management of hyperparathyroidism.

The skeletal manifestations of hyperparathyroidism are due to the stimulation of osteoclast-mediated bone resorption by high circulating concentrations of parathyroid hormone (PTH). Since diphosphonates inhibit PTH-mediated bone resorption, we assessed the effects of clodronate in 42 patients with hypercalcaemia and increased bone resorption due to primary hyperparathyroidism (20 patients), secondary hyperparathyroidism in chronic renal failure (12 patients on haemodialysis replacement therapy) and tertiary hyperparathyroidism following successful renal transplantation (10 patients). Clodronate (0.8-1.6 g daily by mouth or 300 mg given as an intravenous infusion following five consecutive dialysis treatments) significantly decreased serum calcium and biochemical indices of bone resorption in the three groups studied. In primary and tertiary hyperparathyroidism, serum calcium values remained above the upper limit of the reference range despite suppression of bone resorption due to the unopposed effect of PTH on renal tubular reabsorption of calcium. Prolonged treatment (3 months) was associated with a partial recurrence of hypercalcaemia in 8 of 12 patients with primary hyperparathyroidism despite continued effects on bone resorption, possibly due to a secondary decrease in bone formation. These studies indicate that clodronate is capable of suppressing PTH-mediated bone resorption in disorders of parathyroid secretion and may prove to be a useful adjunct in their medical management.

Administration, Oral↗