Biomedical subjects

D Deam

Publications and source records attributed to D Deam.

6 recordsLinked to original sources

PubMed1992

Comparison of two commonly used standard IVGTTs.

OBJECTIVE: To compare the magnitude and reproducibility of the FPIR measured during two different IVGTT protocols in nondiabetic subjects. RESEARCH DESIGN AND METHODS: Nine control subjects each had two pairs of IVGTTs with either a 4-min infusion of 0.5 g/kg glucose or a 1-min infusion of 0.3 g/kg glucose. Blood glucose and serum insulin were measured before and 1, 2, 3, 5, and 10 min after completion of the glucose infusion. The FPIR was measured with either 1 + 3-, 2 + 3 + 5-, or 1 + 3 + 5-min serum insulins, areas under the insulin curve (0-5 or 0-10 min), or the ratio of serum insulin to blood glucose area. RESULTS: The FPIR was higher in eight of nine subjects with the short-infusion test, but the within-subject variation of the two methods was identical. Reproducibility was not significantly improved with an integrated insulin area or insulin-to-glucose ratio measurement. CONCLUSIONS: Reproducibility of the FPIR measured during IVGTT is not significantly affected by the duration of the glucose infusion. However, the magnitude of the difference in FPIR observed between the two protocols highlights the need for standardization of the methodology if the IVGTT is to be used in studies of the preclinical stage of IDDM.

Adult↗

PubMed1991

Comparison of four methods for free thyroxin.

We performed a limited evaluation of four free thyroxin (FT4) reagent kits: the Amerlex-M (AFT4), the Amerlite (LFT4), the MagicLite (MFT4), and the GammaCoat two-step RIA (GFT4). FT4 was measured in specimens from 201 subjects: 19 healthy controls, 14 patients who were thyrotoxic, 13 who were hypothyroid, 59 who had a past history of thyroid disease, seven with thyroxin autoantibodies, seven who were taking amiodarone, and 82 who had no clinical indication of thyroid hormone abnormality. Of these 201 subjects, 78 had a low serum albumin (less than 35 g/L) and 27 had severe nonthyroidal illness. We also investigated 60 pregnant subjects. We found no correlation between thyroxin-binding globulin (TBG) and FT4 in any of the assays, and only the AFT4 method showed a significant correlation with albumin concentrations. The presence of autoantibodies to thyroxin affected the results of all methods except the GFT4 method. All methods showed a decrease in mean FT4 values in late pregnancy. Correlation of patients' clinical state and FT4 results suggested that the reference ranges published by the manufacturers need to be modified for our laboratory.

Adolescent↗

PubMed1990

Cerebrospinal fluid biochemistry in the diagnosis of multiple sclerosis.

The Poser criteria for diagnosing multiple sclerosis (MS) includes clinical, paraclinical and laboratory information. We studied the influence of cerebrospinal fluid (CSF) biochemistry results on the categorisation of patients with suspected MS. A retrospective study was made of 138 patients who had CSF samples sent over a 1 year period to the laboratory for examination for oligoclonal bands. Using the Poser criteria, 23 patients were diagnosed as having definite MS and one patient as probable MS. Cerebrospinal fluid biochemistry upgraded the categorisation from probable to definite MS in 16 of these 24 patients (66%). In this study, we found oligoclonal bands to be more sensitive in the diagnosis of MS (96%) than either the concentration of IgG in the CSF (43.5%) or the IgG expressed as a percentage of the total protein in the CSF (71%). We conclude that CSF biochemistry is a valuable investigation in the evaluation of patients with suspected MS.

Adolescent↗

PubMed1989

Alpha-1-antitrypsin in liver disease.

Low alpha-1-antitrypsin (AAT) levels are known to be associated with liver disease. As AAT is also synthesised in the liver, we investigated whether liver disease itself may result in low AAT levels. AAT was measured in plasma from 100 patients with various liver diseases including hepatitis, cirrhosis, jaundice and liver failure. Twenty-eight patients had increased AAT values (greater than 3.1 g/L), 70 had normal AAT values (between 1.5 and 3.1 g/L) and 2 had decreased AAT levels (less than 1.5 g/L). The 2 patients with low AAT levels were found to be of the PiMZ phenotype. There was no significant correlation between any of the standard 'liver function tests' and the AAT level. Our findings suggest that in liver disease AAT levels are usually normal or increased. Low levels are uncommon and the possibility of an abnormal AAT phenotype being associated with the liver disease should be examined.

Adolescent↗

PubMed1987

Anomalous thyrotropin values.

We studied problems associated with use of an "ultrasensitive" thyrotropin (TSH, thyroid-stimulating hormone) assay for diagnosis of hyperthyroidism. Of 955 TSH assays performed in our laboratory during four months, 135 gave TSH values less than 0.1 milli-int. unit/L. We noted low TSH values at all concentrations of free thyroxin (FT4) in plasma. Nine of 13 patients with a normal or low FT4 and no obvious endocrine explanation for a low TSH were elderly and ill. This raises questions about the pituitary function in such patients. Twenty-seven patients who had high FT4 and non-suppressed TSH were clinically euthyroid, 20 of them being on treatment with thyroxin or amiodarone. Low TSH values in a hospital environment do not always indicate hyperthyroidism, although a normal value for TSH probably indicates euthyroidism.

Acute Disease↗

PubMed1987

Cholinesterase assay automated in the Cobas-Bio centrifugal analyzer.

We describe a method for measuring plasma cholinesterase (EC 3.1.1.8) and dibucaine and fluoride numbers by using the Cobas-Bio. Benzoyl choline chloride is used as substrate. Reaction conditions are the same as in the corresponding manual method. The reaction is stopped with physostigmine. Choline oxidase (EC 1.1.3.17) is coupled with 4-aminoantipyrene. In the presence of peroxidase (EC 1.11.1.7), the 2-hydroxy-3,5-dichlorobenzenesulfonate indicator reaction gives a red product, measured at 505 nm. The analyzer is used in the "Multi Run" mode, with plasma cholinesterase and dibucaine and fluoride inhibition concurrently measured for eight samples. Coefficients of correlation between the manual and present method for plasma cholinesterase and dibucaine and fluoride numbers in 40 patients of various phenotypes were 0.843, 0.923, and 0.717, respectively. The inter-batch CV for each of the three assays was 2% to 3%.

Autoanalysis↗