PubMed Health⌕ Search

Biomedical subjects

E M Duke

Publications and source records attributed to E M Duke.

4 recordsLinked to original sources
PubMed1991

Towards time-resolved diffraction studies with glycogen phosphorylase.

Laue diffraction with high intensity, broad-spectrum synchrotron radiation sources allows three-dimensional data sets on protein crystals to be recorded in seconds or milliseconds and opens the way for time-resolved studies on dynamic events in crystals. This chapter briefly reviews the field and describes progress towards time-resolved studies with glycogen phosphorylase. Methods for the synchronization of the start of reaction with the start of data collection have been developed for the phosphorolytic reaction of glycogen phosphorylase. The compound 3,5-dinitrophenylphosphate is photolabile, yielding Pi and the by-product, 3,5-dinitrophenol, which is non-reactive with the enzyme. Spectroscopic studies show that the compound has good quantum yield and that photolysis is rapid (greater than 1000 s-1). Release of the dinitrophenylate anion, following a pulse of light from a xenon flash lamp, has been monitored with a diode array spectrophotometer specially adapted for measurements on crystals. In a laboratory X-ray experiment with crystals of glycogen phosphorylase b, release of Pi and formation of the enzyme-product complex have been demonstrated. The way is now open for Laue diffraction studies on the catalytic reaction in the crystal.

Crystallography↗
PubMed1985

Thyroid dysfunction in Down's syndrome.

One hundred and sixteen children with Down's syndrome, living in the community, were examined for clinical or laboratory evidence of thyroid dysfunction. Three were hypothyroid and one was hyperthyroid. Twenty eight (29%) had thyroid autoantibodies. Autoimmune conditions were present in first or second degree relatives of 35 (30%) of the children, and in 17 (15%) this was a thyroid disorder. The families of normal control children also showed a 30% incidence of overt autoimmune conditions, and 19 (16%) families showed overt thyroid disease.

Adolescent↗
PubMed1984

Carrier detection in the testicular feminisation syndrome: deficient 5 alpha-dihydrotestosterone binding in cultured skin fibroblasts from the mothers of patients with complete androgen insensitivity.

Specific binding of 5 alpha-dihydrotestosterone (androgen receptor activity) could not be detected in cultured genital skin fibroblasts (GSF) from two patients with complete androgen insensitivity (CAI). In GSF from the mother of one patient, androgen receptor activity (8.5 fmol/mg cell protein) was reduced in comparison with controls (34.0 +/- 10.1 (SD) fmol/mg protein n = 15). These results favour X linked inheritance of CAI and X inactivation at the androgen receptor locus. Androgen receptors were not detected in GSF of the second mother. It appears that female carriers of CAI could be detected by decreased 5 alpha-dihydrotestosterone binding in GSF. Androgen receptor activity was also undetectable in non-genital skin fibroblasts (NGSF) from the second mother and two further CAI patients. However, in 1 in 10 control NGSF lines androgen receptor activity was at the lower limit of assay sensitivity (1 to 2 fmol/mg protein) demonstrating that NGSF may not be reliable for family studies of androgen receptor deficiency.

Adult↗