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Biomedical subjects

T Harvey

Publications and source records attributed to T Harvey.

8 recordsLinked to original sources
PubMed1992

A new approach to the management of Broviac catheter infection.

Infection continues to be a major complication of the use of indwelling venous catheters. In an attempt to avoid removal of the catheter and to minimize the systemic side-effects of antibiotics, the potential value of in-situ treatment of confirmed Broviac catheter infection was assessed in carefully selected patients attending an oncology unit. Fourteen episodes from 11 children were included in the study. A variety of organisms were encountered. Infective episodes were divided into two categories: (a) those occurring in patients with negative peripheral blood cultures and neutrophil count greater than 1.5 x 10(9) l-1 which were treated only by local instillation of heparinized antibiotic 8-hourly for 7-14 days (N = 8); (b) those occurring simultaneously with positive peripheral blood culture (or peripheral blood culture not performed) regardless of neutrophil count, or infection restricted to Broviac catheter but with a neutrophil count of less than 1.5 x 10(9) l-1; these were treated, with one exception, as above with the addition of systemic antibiotics (N = 6). Treatment was successful in 100% of infective episodes with negative cultures achieved between 5 and 12 days. Catheters remained in use a mean of 118 days following treatment of infection. This approach has obvious advantages but requires careful patient selection and monitoring. It prolongs the catheter life, obviates the need for systemic antibiotics for a local infection, and with appropriate instruction to parents and family practitioner, treatment may be administered on an outpatient basis.

Adolescent↗
PubMed1991

Conformation of sarafotoxin-6b in aqueous solution determined by NMR spectroscopy and distance geometry.

The solution structure of sarafotoxin-6b in water has been determined using high-resolution NMR spectroscopy. 127 proton-proton distance measurements and three phi dihedral angle constraints derived from NMR spectra were used to calculate the solution structure using a combination of distance geometry and restrained molecular dynamics. The major structural feature of the resulting family of five structures was a right-handed alpha-helix extending from K9 to Q17. In contrast, the C-terminal region of the peptide appears not to adopt a preferred conformation in aqueous solution. The present structure is compared with those previously determined for endothelin peptides in non-aqueous solvents.

Amino Acid Sequence↗
PubMed1985

Relation of gene expression (allotypes) of the fourth component of complement to insulin dependent diabetes and its microangiopathic complications.

About a quarter of insulin dependent diabetics have low concentrations of the fourth component of complement (C4), and a low concentration of C4 is associated with diabetic microangiopathy. The variability of the expression of the C4 gene was compared in insulin dependent diabetics with and without microangiopathy and controls. Of the two genes coding for C4, the A gene (C4A) was not expressed--that is, C4A null--in 16 (13%) of the 126 insulin dependent diabetics compared with none of the 93 controls (p less than 0.001), and all these 16 subjects had low concentrations of C4. Lack of expression of the other C4 gene (C4B) was not associated with insulin dependent diabetes, but a rare variant, C4B3, was significantly increased in the diabetics (21/126; 17%) compared with the controls (none) (p less than 0.001). The prevalence of C4B3 was also increased in the diabetics with complications when compared with those without (14/50 (28%) v 7/76 (9%), p less than 0.01). Low plasma C4 concentrations in insulin dependent diabetics are at least partly due to variation in the expression of the C4 gene. The association of the rare C4B3 variant with microangiopathy suggests a genetic component of its aetiology.

Adolescent↗
PubMed1985

On the brain of a scientist: Albert Einstein.

Neuron:glial ratios were determined in specific regions of Albert Einstein's cerebral cortex to compare with samples from 11 human male cortices. Cell counts were made on either 6- or 20-micron sections from areas 9 and 39 from each hemisphere. All sections were stained with the Klüver-Barrera stain to differentiate neurons from glia, both astrocytes and oligodendrocytes. Cell counts were made under oil immersion from the crown of the gyrus to the white matter by following a red line drawn on the coverslip. The average number of neurons and glial cells was determined per microscopic field. The results of the analysis suggest that in left area 39, the neuronal: glial ratio for the Einstein brain is significantly smaller than the mean for the control population (t = 2.62, df 9, p less than 0.05, two-tailed). Einstein's brain did not differ significantly in the neuronal:glial ratio from the controls in any of the other three areas studied.

Aged↗
PubMed1977

Hypocalcemic effect of aminoglycoside antibiotics in the dairy cow.

The effect of the parenteral administration of aminoglycoside antibiotics on the blood calcium concentration in dairy cows was investigated. Gentamicin was tested in vitro in blood drawn from cows, dihydrostreptomycin was tested in nonlactating cows and neomycin was tested in postpartum cows. The total and bound calcium fractions were significantly reduced by all three antibiotics. No change occurred in the unbound calcium fractions. Caution is advised in the use of these drugs in postpartum cows, especially those with a history of milk fever.

Aminoglycosides↗