Biomedical subjects
Publications and source records attributed to J N Mount.
Immunoturbidimetric assays for measuring the apolipoproteins A1 and B using the Cobas Bio centrifugal analyser are described. The methods were specific, offered good sensitivity (less than 0.05 g/l) and intrabatch variability, with coefficients of variation between 2.4% and 3.5%, and were cost effective. Reference ranges were calculated for a group of civil servants, aged 35 to 55 years.
Galactosaemia has been suggested as a contributory factor in the pathogenesis of some presenile and senile cataracts. To assess whether galactosaemia plays any part in the development of atopic cataracts a galactose tolerance test was carried out in eight atopic dermatitis patients whose cataracts had appeared between the ages of 12 and 39 years. In seven patients a normal result was obtained and in one the result was just above normal. Impaired galactose tolerance appears to have no role in the pathogenesis of atopic cataract.
Explore the source record for details and available documents.
Adaptation of coenzyme stimulation assays for the nutritional assessment of thiamine, riboflavin and pyridoxine on the Cobas Bio centrifugal analyser are described. Whole blood was collected into acid-citrate dextrose, which preserves the erythrocytes, prior to assay for several days. Washed erythrocytes stored at -70 degrees C and subsequently thawed, showed altered enzyme activities. The methods offer improved precision over existing procedures and take advantage of the high throughput capabilities of the instrumentation.
Disease activity was assessed clinically and erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), orosomucoid, alpha 1-antitrypsin (alpha 1AT) and alpha 2-macroglobulin (alpha 2M) were measured in 65 patients with ankylosing spondylitis (AS). Positive correlations were found between ESR and the acute phase proteins (APP), CRP, orosomucoid and alpha 1AT, but none of these variables correlated with the clinical assessment of activity. No relationship was demonstrated between the protease inhibitor, alpha 2M and clinical activity, ESR or any of the APP. While the treatment of AS remains predominantly symptomatic, routine management of patients should continue to be founded on the clinical assessment of disease activity rather than on laboratory indices of inflammation.
Partial deficiencies of the enzymes of galactose metabolism can be associated with cataract, both directly and through maternal effects during pregnancy on enzymatically normal children. However, the associations are modest, variable and not obviously expressing cause and effect. We have recorded ophthalmological and biochemical observations including oral galactose tolerance on families with established enzyme deficiencies and/or cataracts, including possible effects during pregnancy. With the partial disorders a simple relationship between the extent of biochemical abnormality and the risk of cataract is not apparent and the association may be substantially coincidental. Cataract is common, and the attractive possibility that expression is significantly due to heterozygous or lesser deficiency of the enzymes of galactose metabolism, amenable to early dietary control of children or mothers at risk, is on present evidence not well supported.
Minor and major deficiencies of enzymes affecting galactose metabolism may be associated with cataracts of early onset. Results are presented for 10 such families with minor enzymatic disorders. Expression of the major disorders probably involves galactitol accumulation and osmotic lens damage but this mechanism is not obviously associated with minor disorders. The observed incidence of minor incomplete enzymatic disorders of galactose metabolism in families with an incidence of cataracts of early onset may be at least partly incidental.
Cataracts may arise in association with various major and minor disorders restricting galactose metabolism, and the risk is broadly associated with the degree of galactose intolerance. A family is described in which a girl presented at the age of 7 3/4 years with cataracts, galactosuria, and partial deficiencies of the enzymes galactokinase and galactose-1-phosphate uridyl transferase. Galactose intolerance as determined by an oral test was impaired and fluctuated with variation in activity of the above galactose enzymes. Minor defects were also present in the parents and a maternal half-brother. The child has a compound disorder of galactose metabolism differing from those previously described. Assessment of galactose tolerance may be useful in the investigation of families with an incidence of cataract.
Explore the source record for details and available documents.
We describe a procedure for estimating mannitol concentrations in biological fluids. Samples are mixed with internal standard solution (alpha-methylglucose), deproteinized if necessary, desalted, and dried. Specimens are then derivatized by adding pyridine/bis(trimethylsilyl)acetamide/trimethylchlorosilane and heating at 60 degrees C for 30 min. Samples are chromatographed on a 275-cm column of 10% OV-17, operated at 190 degrees C, and quantitated by peak-height measurement. The technique is linear, accurate, precise, sensitive, and free from interference. It has been used to measure mannitol in plasma, urine, and bile.
A method is described for the quantitative estimation of clinically important monosaccharides in plasma or whole blood by direct densitometry of chromatographically-separated zones on silica gel layers. Simple modifications of technique originally introduced to improve the reproducibility of paper chromatography have now been adapted for thin layers. The present method is based on peak height measurement with an internal marker correction. Galactose, fructose, D-xylose, and 3-O-methyl glucose can be estimated in addition to glucose, either singly or in combination, within three or four hours, using an initial sample volume of 0.5 ml. With reasonable experience and skill a coefficient of variation of 3 to 6%, depending on sugar concentration, can be achieved without replication, and the limit of sensitivity is about 0.05 mmol/l. When the performance was compared with an automated glucose oxidase/peroxidase system for glucose and the recovery for the other monosaccharides was calculated, the results were satisfactory.
Explore the source record for details and available documents.