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Biomedical subjects

J G Taylor

Publications and source records attributed to J G Taylor.

12 recordsLinked to original sources

Accessory olfactory learning.

Learning in the accessory olfactory bulb is modelled mathematically by means of a set of coupled oscillator equations to describe the ongoing activity. The modification of this activity by experience is shown to lead to a change of the transfer function of the AOB as an input-output device. This leads both to a test of the model and a means of discovering how the later stages of the brain may use the AOB output. Our discussion is limited to a specific form of learning in the mouse, but may have more general applicability.

Animals

Synovectomy of the elbow in rheumatoid arthritis: the place of excision of the head of the radius.

The results of thirty synovectomies of the elbow for rheumatoid arthritis are reported. Satisfactory relief of pain was obtained in twenty-seven elbows and the range of movement was improved in twenty-one. The classical operation includes excision of the radial head but in this series approximately half the radial heads were conserved with comparable results. The results of synovectomy do not significantly deteriorate with time up to ten years and the operation can be done with good results, especially in respect of relief of pain, even in elbows with relatively advanced rheumatoid disease. Radiographic assessment is not of much help in evaluating the results of the operation, but is essential in selection of elbows for synovectomy.

Adolescent

A comparison of the Freeman-Swanson (ICLH) and Walldius prostheses in total knee replacement.

Seventy-five Freeman-Swanson (ICLH) Mark I total knee replacements, all performed in one orthopaedic unit between 1972 and 1975, were independently reviewed. The fifty-eight surviving patients, with sixty-eight arthroplasties, have been interviewed and examined and the clinical records of the deceased patients inspected. Sixty arthroplasties (80 per cent) were successful and fifteen failed (20 per cent). There were no disasters. Twenty (33.8 per cent) of the successful arthroplasties were excellent. It is expected that modification of the prosthesis and improved instrumentation will increase this percentage of excellent results and reduce the failure rate.

Adult

Diabetic dimorphism according to acetylator status.

Two groups of diabetics and 19 normal controls had their rate of acetylation of sulphadimidine measured. Among 47 patients with maturity onset diabetes the 29 fast acetylators were older at diagnosis and, at a given glucose concentration, had a higher pretreatment fasting insulin concentration than slow acetylators. They also had a larger first-phase insulin secretion in response to intravenous glucose both before and after one month's dietary treatment. The greatest difference between fast and slow acetylators was in the first-phase secretion of insulin after a month's treatment. The proportion of fast acetylators among the second group of diabetics, who had been admitted to improve their glucose concentrations or for treatment of tissue damage, was similar to that among the normal controls (50% and 47% respectively). The data seem to indicate that diabetics are fast acetylators unexpectedly often, but it is not clear whether the dimorphism according to acetylator status produces a differential risk of neuropathy or of any other type of diabetic tissue damage.

Acetylation

Experience with knee synovectomy in Norwich, 1964-1973.

Thirty-six patients (43 knees) who underwent anterior synovectomy for rheumatoid disease between 1964 and 1973 have been personaly reviewed. The notes and X-rays of a further seven patients (10 knees) have been examined. Twenty-five per cent of the knees were failures at the time of review, but only two were failures from the outset. The indications for the operation and also the contraindications are described and evaluated. It is concluded that: 1. In the rheumatoid knee, anterior synovectomy is a pain relieving operation. 2. The indications are wider than classically stated, and can include knees with full thickness cartilage destruction, and flexion deformities up to 20 degrees. 3. The majority of knees fail because of secondary degenerative change, and this is manifested by pain rather than stiffness. 4. Postoperative manipulation does not prejudice the final result. 5. Associated popliteal cysts (five in this series) can be cured by anterior synovectomy.

Adolescent

The amino acid sequence of Neurospora NADP-specific glutamate dehydrogenase. The tryptic peptides.

The NADP-specific glutamate dehydrogenase of Neurospora crassa was digested with trypsin, and peptides accounting for 441 out of the 452 residues of the polypeptide chain were isolated and substantially sequenced. Additional experimental detail has been deposited as Supplementary Publication SUP 50052 (11 pages) with the British Library (Lending Division), Boston Spa, Wetherby, W. Yorkshire LS23 7BQ, U.K., from whom copies may be obtained under the terms given in Biochem J. (1975) 145, 5.

Amides

The irreversible binding of acetylcholine mustard to muscarinic receptors in intestinal smooth muscle of the guinea-pig.

1. Acetylcholine mustard (N-2-chloroethyl-N-methyl-2-acetoxyethylamine), a potent muscarinic agonist, binds virtually irreversibly to muscarinic receptors in longitudinal muscle strips from guinea-pig small intesting, as shown by the inhibition of the binding of E13-H]-propylbenzilycholine mustard ([3-H-PrBCM), an affinity label for the muscarinin receptor. 2. A value for the apparent binding affinity of acetylcholine mustard and a value for the rate constant for the receptor alkylation reaction have been deduced from the rate of onset of the inhibition of [3-H]-PrBCM binding. 3. The kinetic constants obtained may refer largely to the interaction between acetylcholine mustard and the desensitized receptor. 4. At high concentrations acetylcholine mustard practically abolishes the contractile response to carbachol. At the concentrations acetylcholine mustard appears to have multiple actions on the tissue.

Acetylcholine

The Walldius hinge arthroplasty.

Eighty-three Walldius arthroplasties, performed by one surgeon as salvage operation on the knee joint between 1966 and 1972, were independently reviewed. The fifty-seven living patients with sixty-seven arthroplasties were interviewed and examined and the clinical records of the deceased patients were inspected. Sixty-seven arthroplasties (81 per cent) were successful and sixteen failed (19 per cent). Acrylic cement was used to secure the prosthesis on eight occasions only. There were two primary infections (2-4 per cent) and two delayed (2-4 per cent). Major loosening occurred in three arthroplasties (3-6 per cent). Minor loosening was compatible with a good result. Arthrodesis was successful on the two occasions on which it became necessary to remove the implant. There were no disasters. On the basis of these results it is considered that the Walldius arthroplasty can justifiably be offered as an alternative to primary arthrodesis of the knee.

Adolescent