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Biomedical subjects

A J Davison

Publications and source records attributed to A J Davison.

126 records · Page 7Linked to original sources
PubMed1978

Recombinants between herpes simplex virus types 1 and 2: analyses of genome structures and expression of immediate early polypeptides.

Recombinants between temperature-sensitive mutants of herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) were constructed. Using restriction endonucleases, we analyzed the genome composition of 17 intertypic recombinants and detected crossovers in every region of the genome. The virion DNA of one recombinant appeared to be largely "frozen" in two of the four possible genome arrangements of HSV. Knowledge of the genome structures of recombinants enabled us to physically map immediate early polypeptides. We present evidence that the immediate early polypeptide Vmw IE 110 of HSV-1 and its functionally equivalent polypeptide, Vmw IE 118, of HSV-2 may map in the repetitive sequences bounding the long unique region of HSV.

DNA Restriction Enzymes↗
PubMed1976

A comparison of three health status indicators.

Interest in health status indicators has produced measures of widely varying applicability. We were interested in the use of such indices to establish mean recovery curves for groups of similar patients undergoing acute hospital treatment. A longitudinal study relating resource usage to these recovery curves had been intended but there were difficulties in finding suitable indicators. Firstly, two published indicators relying on patient interviews were tested for consistency. Poor correlations were found among those scorers unfamiliar with the patients and it seems unlikely that these indicators could be used in a routine system. Different parts of the indices presented difficulties to the different professions involved in scoring, and a multidisciplinary approach may be needed in assessing full health. The indicators tested included no assessment of prognosis. Those parts of the indices which had produced significant correlations were retained in subsequent work and were supplemented by further measures designed to overcome the earlier difficulties. A new trial of this indicator was undertaken where staff, familiar with the patients, scored data recorded by the Problem Oriented Medical Record system. This produced improved correlations but some problems remain.

Disability Evaluation↗
PubMedDate not supplied

Benign parotid adenomas: a review of the Princess Margaret Hospital experience.

BACKGROUND: The morbidity of treating benign parotid tumors is an important issue because the majority of patients are young. We therefore undertook this study to evaluate the outcome for these patients treated at the Princess Margaret Hospital. METHODS: A retrospective review was conducted on all patients registered with benign parotid tumors between 1970 and 1987. RESULTS: Seventy-six patients were included in this review; postoperative radiotherapy (XRT) was administered to 55 patients. Median follow-up time was 12.5 years. Postoperative XRT was particularly important for patients with recurrent disease. The risk of both temporary and permanent facial nerve paralyses increased with each operation. No patients in this study developed a malignancy. CONCLUSIONS: We recommend that all patients with benign parotid tumors be treated with a complete parotidectomy with preservation of the facial nerve. Consideration to postoperative XRT should be given to patients in whom there was tumor spillage, residual disease, or recurrences.

Adenoma↗
PubMedDate not supplied

Among a range of transition metals and ligands vanadium.desferroxamine excels in accelerating reactivity of ferrocytochrome c toward molecular oxygen.

Despite early knowledge of the requirement for metals in the reactions of ferrocytochrome c with oxygen, the relative effectiveness of metals and the factors that modulate effectiveness remain unknown. We have compared the catalytic power of five metals and report the effects of pH and ligand on their effectiveness as catalysts. Catalysis by metal ions was greatest at higher pH, where the rate of aerobic oxidation was lowest. Iron (Fe2+), copper (Cu2+), vanadium(V) (V(V)), manganese (Mn2+), and aluminum (Al3+) were tested in combination with EDTA, ADP, histidine, or desferrioxamine (Des) at pH 2.6, 3.2, and 4.0. At pH 2.6, only vanadium(V) increased the initial rate of the oxidation of ferrocytochrome c (by 6.2-fold). At pH 4.0, however, all the metals markedly stimulated the oxidation of cytochrome c. The order of effectiveness was V(V).Des >> Cu.ADP2+ > Fe.EDTA2+ > Mn.Des2+ > Al.EDTA3+ (where the stated ligand represents the most stimulating one for a given metal). At pH 3.2 the metal complexes had intermediate effects, with vanadium again being the most effective. The preeminence of vanadium among the metals is novel. Where the heme crevice is closed (pH 4), transition metal ions mediated almost all of the reduction of oxygen, while at the lowest pH (2.6) transition metal ions were largely unnecessary. Vanadium(V) was the most active of the metals at all values of pH and the only metal to accelerate the oxidation of ferrocytochrome c at pH 2.6. Understanding of the range of biological actions of vanadium will not be complete without a knowledge of its redox reactivity within the components of biological systems.

Adenosine Diphosphate↗