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Biomedical subjects

S P Harrison

Publications and source records attributed to S P Harrison.

13 recordsLinked to original sources
PubMed1992

Characterisation of Rhizobium isolates by amplification of DNA polymorphisms using random primers.

The use of single random primers, selected in the absence of target sequence information, has been shown to be effective in producing DNA amplifications that provide fingerprints which are unique to individual organisms. DNA amplification by random priming was applied to the DNA from isolates of Rhizobium leguminosarum biovar trifolii. Amplification products were produced using a number of primers, and the resulting fingerprints allowed strain differentiation. However, the effectiveness of primers was dependent upon length and GC content. It was also possible to amplify DNA directly from cells in culture and in nodule tissue. Lysis of these cells was achieved simply through heat applied in the initial DNA denaturation stage of the thermal reaction. The ability to produce varied amplification patterns from different Rhizobium isolates, especially directly from nodules, gives this method potential for use in examining genetic structures and relationships in Rhizobium populations.

Base Sequence↗
PubMed1991

Insulin modulation of acute-phase protein production in a human hepatoma cell line.

Insulin is widely used as a growth factor in hepatocyte culture but its effect on the production of acute-phase proteins has not been studied. By measuring four positive (fibrinogen, alpha 1-antitrypsin, alpha 1-acid glycoprotein, and alpha 1-antichymotrypsin) and four negative (albumin, prealbumin, transferrin, and retinol binding protein) acute-phase proteins produced by the Hep G2 hepatoma cell line, we have shown that insulin is an important modulator of acute-phase protein production. Our data show that insulin is able to inhibit the synthesis of prealbumin, transferrin, and fibrinogen. The results also show a complex interaction between insulin, interleukin 6, and glucocorticoids because insulin is able to inhibit the dexamethasone induction of alpha 1-antichymotrypsin, and in the presence of interleukin 6, dexamethasone is able to regulate the production of fibrinogen and prealbumin. The regulatory role of insulin in fibrinogen production was confirmed by pulse chase labeling followed by immunoprecipitation and fluorography.

Acute-Phase Proteins↗
PubMed1991

Assessment of protein intake in early progressive renal disease.

Mean protein intake in a 4-day dietary survey of 34 patients with early renal disease was 1.2 +/- 0.27 g/kg ideal body weight daily. Nine subjects were taking over twice the recommended minimum intake. An increased protein intake was associated with a greater phosphate and sodium intake and an increased excretion of urea, phosphate, and sodium. Daily intake fluctuated markedly during the study (coefficient of variance 22.5 +/- 10.9%). Protein catabolic rate calculated from urea excretion correlated with protein intake, r = 0.60. Mean difference between the two estimates was 0.04 +/- 0.28 g/kg per day. It is proposed that if urea excretion exceeds 4.5 mmol/kg per day in a single collection (protein catabolic rate 0.98 g/kg per day), serial measurements should be made to determine protein intake more accurately and give dietary advice.

Adult↗
PubMed1989

Three direct spectrophotometric methods for determination of total bilirubin in neonatal and adult serum, adapted to the Technicon RA-1000 analyzer.

We adapted three bichromatic spectrophotometric methods for determining total bilirubin in serum, for use with the Technicon RA-1000 analyzer. The borate buffer (BOR) of Hertz et al. (Scand J Clin Invest 1974;33:215-30), the caffeine buffer (CAF) of Vink et al. (Clin Chem 1988;34:67-70), and the combined borate-caffeine buffer (B-C) of Franzini and Cattozzo (Clin Chem 1987;33:597-9) were compared. All methods required only 10 microL of serum, were precise (between-batch CVs less than 4.2%, analyte range 64-310 mumol/L), linear to 1000 mumol/L, and insensitive to interference from hemoglobin to 5 g/L. Lipemia, carotene, and methemalbumin interfered positively with each method but insignificantly unless in supranormal concentrations. Only the BOR method was sensitive to protein matrix effect. Neonates' results obtained with all three methods compared well with a Jendrassik-Gróf-based technique. However, samples from adults with cholestasis were overestimated, particularly by the CAF method, but the BOR and B-C methods would be suitable for "stat" bilirubin analysis in these samples.

Adult↗
PubMed1988

Evaluation of the Technicon Chem-1.

We evaluated the performance of 15 colorimetric and three ion-selective electrode assays in the Technicon Chem-1 serum analyzer and briefly assessed the suitability of plasma and urine for analysis in the system. Within- and between-batch precision, accuracy, correlation, and linearity of all methods was acceptable but some assays, notably those for bicarbonate and creatinine, were susceptible to interferences. Except for the total bilirubin and lactate dehydrogenase assays, plasma can be assayed successfully in the instrument. Urine samples can also be assayed but specimens for phosphate analysis must be diluted in a polyvinylpyrrolidone solution before analysis, and the calcium method is sensitive to variations in urinary pH.

Autoanalysis↗