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Biomedical subjects

R Wilkinson

Publications and source records attributed to R Wilkinson.

At least 415 records · Page 23Linked to original sources

Immunosuppression with polyunsaturated fatty acids in renal transplantation.

A double-blind controlled trial has been undertaken to assess the value of a preparation containing polyunsaturated fatty acids (PUFA) in human cadaveric renal transplantation. Eighty-nine patients were studied and followed for 6 months after transplantation. Forty-four took the PUFA preparation and 45 the placebo (oleic acid). Other immunosuppression was standardised. Functional graft survival was significantly better in the PUFA group than in those taking the placebo during the first 3 to 4 months post-transplant. At 6 months, however, although the difference between the groups persisted, it was no longer statistically significant. Complications were equally distributed between the groups.

Adult↗

Addison's disease with renal microangiopathy and renal failure (a new syndrome).

A syndrome comprising Addison's disease, renal microangiopathy and renal failure is described in two patients. The renal lesions manifested despite corticosteroid replacement therapy and were characterized by glomerular damage and thrombo-microangiopathic changes in afferent arterioles and intralobular arteries. Both patients died as a result of their renal disease.

Addison Disease↗

Cramps, thirst and hypertension in hemodialysis patients -- the influence of dialyzate sodium concentration.

The effect of increasing dialyzate sodium concentration from 130 to 136 mmoles/l on the incidence of muscle cramps in patients on regular dialysis treatment is assessed. This change was found to be effective in markedly reducing the incidence of cramp at the cost of a slight rise in the complaint of thirst. Mean arterial pressure rose slightly but significantly and exchangeable sodium was increased to levels comparable to those measured during 1969, when with twice weekly dialysis hypertension was a problem. It is concluded that dialyzate sodium concentration may with benefit be increased to 136 mmoles/l, provided that blood pressure is carefully monitored.

Blood Pressure↗

Actions of growth hormone-release inhibiting hormone (somatostatin) on the renin aldosterone system.

Administration of growth hormone-release inhibiting hormone (GH-RIH, somatostatin), as a 90 minute infusion (10 mug/min), to 3 healthy young men under conditons of active renin secretion acheived by pretreatment with furosemide (80 mg daily for 5 days), caused a mean 30% fall in plasma renin activity, which returned to basal levels immediately after stopping the GH-RIH infusion. Plasma aldosterone levels were not affected during the course of this experiment.

Adult↗

The effect of recurrent early homograft rejection on subsequent patient and renal graft survival.

The effect of recurrent early homograft rejection on subsequent patient and renal graft survival. Two hundred renal transplants performed in Newcastle between 1968 and 1974 and followed up for at least 6 months are reviewed. There was a significant fall ingraft survival at 1 year in those patients who suffered a rejection episode during the first two months post-transplant and this fall became greater with each successive rejection episode. The rise in patient mortality with increasing numbers of rejections showed a similar trend but was less (40-50% at 1 year in those suffering 3 or 4 rejection episodes) and did not reach statistical significance beyond the first episode. We, therefore, conclude that in patients not suitable for home dialysis and in whom, because of uncommon tissue type, a second transplant is not likely to be offered under prevailing conditions of kidney donor shortage, it is justifiable to treat third and fourth rejections occurring during the first two months.

Acute Disease↗

A comparison of short and long haemodialysis.

Two groups of patients treated by short (Milan) and long (Newcastle) haemodialysis were compared for incidence of symptoms and biochemical control. Short dialysis corrected urea and creatinine as well but control of potassium and phosphate were similar. The only apparent penalties to be paid by short dialysis patients were a higher incidence of itching, tingling or numbness, impairment of vibratory sense and difficulty in controlling blood pressure. The short dialysis group had higher haemoglobin and less dyspnoea, muscle weakness and dizziness after dialysis.

Adult↗

Effects of time zone changes on performance and physiology of airline personnel.

This study is the second of a series of experiments describing the effects of time zone changes on the performance and menstrual cycle changes in a group of 16 female airline personnel. Four groups of four subjects each spent 4 d in the isolation unit of the University of Manchester. One group acted as control; the other three groups were subjected to two 8-h retardations in time, representing Westerly flight. All groups were required to complete an identical battery of workload tasks. In addition, the effects of a therapeutic preparation (mepiprazole hydochloride) were studied in a double-blind experiment. The results of the study confirmed previous experiments in that there was impaired performance in individuals subjected to time zone changes when work was carried out in local time, but the results were difficult to compare with those obtained in Easterly shifts. The therapeutic agent appeared to have little influence on the effect of time zone changes upon subjects, although they reported favourably on its use.

Adult↗

Methylation of rat liver mitochondrial deoxyribonucleic acid by chemical carcinogens and associated alterations in physical properties.

The formation of 7-methylguanine in rat liver mitochondrial DNA following the administration of the powerful carcinogen, dimethylnitrosamine, and the weak carcinogen, methyl methanesulphonate was measured and compared to the alkylation of nuclear DNA by these agents. At all doses tested mitochondrial DNA was alkylated more extensively than nuclear DNA by dimethylnitrosamine but both types of cellular DNA were alkylated to about the same extent by methyl methanesulphonate. The physical structure of rat liver mitochondrial DNA isolated from animals treated with these agents was investigated by electrophoresis in agarose gels and by isopycnic centrifugation in CsCl gradients. These procedures carried out in the presence of ethidium bromide, an intercalating dye, separate closed circular forms of mitochondrial DNA from open circular molecules (containing a single-strand break) and linear molecules. Administration of dimethylnitrosamine produced a considerable decrease in the amount of mitochondrial DNA which could be isolated in the closed circular form and at higher doses of dimethylnitrosamine no closed circular mitochondrial DNA could be found. Methyl methanesulphonate was less effective at reducing the amount of closed circular mitochondrial DNA. One explantation of these results is that dimethylnitrosamine leads to strand breaks in mitochondrial DNA and the possible use of this system to investigate carcinogen-induced breaks in DNA is discussed.

Animals↗

Variation in the temporal characteristics of the vocalizations of bullfinches, Pyrrhula pyrrhula.

Temporal characteristics of the vocalizations of bullfinches were investigated. The calls produced by experimentally isolated bullfinches were subjected to sonagraphic analysis. Within individual, between individual, and local variation in these calls was demonstrated. Several categories of calls were described, of which those termed "sequence calls" contained the greatest amount of information on which individual recognition could be based. Contact calls were individually distinctive in terms of their duration but with the exception of those produced by one female these lacked the structural complexity and information content of the sequence calls.

Animal Communication↗

Effect of correction of metabolic acidosis on bone mineralisation rates in patients with renal osteomalacia.

The role of metabolic acidosis in the genesis of renal osteomalacia was investigated by studying bone mineralisation and resorption rates with a combined isotope and balance technique in six patients, before and after the administration of alkali. Correction of blood pH was achieved in five cases and was associated with a significant rise in the bone mineralisation rates and a significant positive trend in the calcium balances. It is suggested that acidosis contributes to the pathogenesis of osteomalacia in renal failure by slowing skeletal mineralisation, possibly by inhibiting bone alkaline phosphatase.

Acidosis↗