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Biomedical subjects

J Walton

Publications and source records attributed to J Walton.

At least 19 recordsLinked to original sources
PubMed1991

Surgical management of the thoracic outlet compression syndrome.

There is some disagreement about whether the first rib should be excised in the presence of a cervical rib for the relief of the thoracic outlet compression syndrome (TOCS). Over a 14-year period (1975-1988) 58 patients have undergone surgery for TOCS. Forty-four patients (76 per cent) had vascular symptoms, 28 (48 per cent) with a neurological component; 11 (19 per cent) had only neurological symptoms. Thirty-six patients (62 per cent) had the first rib excised; 19 (33 per cent) had a cervical rib excised; two (3 per cent) had a division of fibrous bands; and one patient had a large transverse process resected. Follow-up details were available on 53 patients (91 per cent). Overall 38 (72 per cent) were cured of their symptoms, 11 (21 per cent) had a significant improvement, and four (8 per cent) showed no improvement. There was no significant difference between the results following excision of a cervical rib or of a first rib in terms of relief of symptoms. In patients with TOCS who have a cervical rib, excision of the cervical rib alone without excision of the first rib would appear to be an appropriate treatment.

Adolescent↗
PubMed1991

Growth rates of subclinical abdominal aortic aneurysms--implications for review and rescreening programmes.

One hundred and six patients with abdominal aortic aneurysms (AAAs) of 2.5 to 3.9 cm in anteroposterior diameter were reexamined by ultrasound every 6 months for up to 3 years after diagnosis. Annual growth rates were 0.11 cm +/- 0.03 (mean +/- SE) for AAAs 2.5 to 2.9 cm and 0.29 cm +/- 0.08 for AAAs 3.5 to 3.9 cm (P = 0.002). In 73 patients (69%) the annual rate of increase in diameter was 0.2 cm or less and only 12 aneurysms (11%) grew at more than 0.5 cm per annum. We conclude that: (1) for AAAs less than 4.0 cm diameter remeasurement more often than every 6 months is unnecessary; (2) interval screening (rescreening) for AAAs more frequently than 5 yearly is unlikely to detect sufficient clinically significant aneurysms to be worthwhile.

Aorta, Abdominal↗
PubMed1991

Regulation of prostaglandin synthesis in the human amnion.

An increase in prostaglandin synthesis by intrauterine tissues may be responsible for labour initiation and/or maintenance in humans. In all studies to date, the amnion is the intrauterine tissue whose prostaglandin output consistently increases with the onset of labour. This may be due, in part, to acute activation of the phospholipases A2 and C and to an increase in the specific activity of prostaglandin H synthase (PGHS). A number of factors exist in amniotic fluid, the fetal membranes, the decidua and the placenta that can increase PGHS specific activity. Some of these factors may increase PGHS enzyme activity by gene expression and protein synthesis. Preliminary evidence is presented that suggests the hypothesis that PGHS specific activity increases before the onset of labour rather than as a consequence of labour initiation, and that idiopathic preterm labour may frequently be associated with increased PGHS activity. Hence, activation of PGHS gene expression and/or protein synthesis may be causal for term and preterm labour.

Amnion↗
PubMed1990

Brachial artery damage following cardiac catheterisation. When to re-explore.

Cardiac catheterisation is frequently performed in modern medical practice and the brachial artery is frequently used. The brachial and forearm systolic pressures were measured by Doppler ultrasound at rest and after hand exercise for 60 s in 75 patients undergoing catheterisation. These objective measurements, together with a history of forearm claudication during the one minute of exercise and clinical examination of the radial pulse were repeated again at 1 hour, 1 week and 3 months. Changes in the forearm/brachial pressure index (PI) at rest and a fall in forearm pressure after exercise were compared with the pre-catheterisation values. Sixteen per cent of patients suffered claudication of the forearm during the one minute hand exercise immediately after catheterisation. Of those seen at 3 months, 12% had persistent claudication and all had a markedly reduced PI measured following catheterisation. Conversely, at 1 [corrected] hour after catheterisation, the radial pulse was weak or absent in 20% and 33% were abnormal on Doppler studies and not all had symptoms. It emerges that to avoid claudicating forearms at 3 months, re-exploration, one hour after brachial catheterisation is indicated in some cases. We are inclined to base this upon the 16% who had forearm claudication after one minute of exercise and who also had absent or reduced radial [corrected] pulse and abnormal Doppler studies. Conversely to base the need for re-exploration upon a reduction or absence of the radial pulse [corrected] (20%) on Doppler studies (33%) would lead to an unnecessarily high rate of re-exploration just after the procedure.

Arterial Occlusive Diseases↗
PubMed1990

A community detection program for abdominal aortic aneurysm.

This study aimed to discover the prevalence of undiagnosed abdominal aortic aneurysm in the community in men aged sixty-five to seventy-four. All 1,392 men in this age group registered with twenty general medical practitioners were invited for free health screening at hospital and 746 attended. The abdominal aorta was imaged by ultrasound and its anteroposterior diameter measured. An abdominal aortic aneurysm was present in 6.3% and the aneurysm was 4.0 cm or more in diameter in 2%.

Aged↗
PubMed1989

Restoration of memory following septo-hippocampal grafts: a possible treatment for Alzheimer's disease.

The present paper outlines the reasons for the current interest in work on septo-hippocampal grafts. It examines the role of cholinergic dysfunction in the memory deficits associated with Alzheimer's disease, the effects of hippocampal lesions on memory in infra-human animals, and the anatomy of the hippocampus. Methodological aspects of neural grafting are then examined, including the source, nature and site of the graft. A review of the tasks employed to determine functional recovery following septo-hippocampal grafts suggests that although recovery is evident its nature is unclear. An experiment is described which suggests that grafts from embryonic septum bring about recovery of working memory in rats. Different bases of the recovery of function are discussed, including the role of the graft in eliciting release of trophic factors from the host brain; the possibility that the graft acts by providing a pool of neurotransmitter; and finally that the graft may replace the damaged circuitry of the host. Some problems of the grafting procedure are outlined. It is concluded that grafting may provide a viable treatment technique in the absence of other forms of treatment for Alzheimer's disease.

Alzheimer Disease↗
PubMed1989

How fast do very small abdominal aortic aneurysms grow?

Fifty patients with abdominal aortic aneurysms from 2.5 to 5.0 cm in anteroposterior diameter (median 3.1 cm, mean +/- S.E. 3.3 +/- 0.1 cm) were initially offered non-operative treatment. Two patients have subsequently undergone successful elective aneurysm resection because of increase in aneurysm size, and a third has died. The median annual growth rate of the aneurysm has been 0.22 cm and 77.8% increased in size between 6 monthly ultrasound examination. For aneurysms less than 4.0 cm the maximum 6 monthly increment in diameter was 0.7 cm. Even the smallest abdominal aortic aneurysms usually progressively increase in size and 6 monthly ultrasound remeasurement of aneurysm diameter is an essential component of non-operative management.

Aged↗
PubMed1988

Oxford screening programme for abdominal aortic aneurysm in men aged 65 to 74 years.

824 men aged 65 to 74 were invited for ultrasound screening of the aorta and 426 (51.7%) attended. An abdominal aortic aneurysm was discovered in 23 (5.4%), and in 10 (2.3%) the aneurysm was 4.0 cm or more in diameter. 2 other patients had a common iliac artery aneurysm. The 36 men who had objective evidence of occlusive arterial disease of the lower limbs were twice as likely to be tobacco smokers and accounted for 5 (20%) of the aneurysms discovered. Extension of this screening programme to England and Wales could be expected to identify 52,500 men with an abdominal aortic aneurysm. If elective surgical replacement of the aneurysm were to be accepted by 60% of those with aneurysms 4 cm or more in diameter, 6000 unnecessary deaths from aortic aneurysm rupture could be prevented.

Aged↗
PubMed1988

Clumsy children.

Explore the source record for details and available documents.

Child↗
PubMed1988

Ca2+-ATPase deficiency in a patient with an exertional muscle pain syndrome.

31P Magnetic resonance spectroscopy studies were carried out in vivo on skeletal muscle of a patient with verapamil-responsive, chronic, progressive post-exertional muscle pain. A sister suffered from a similar complaint. The results showed that the muscle: (1) decreased its high energy phosphate content more rapidly than normal during exercise, indicating either increased utilisation or decreased production of ATP; (2) acidified more rapidly than normal during exercise suggesting an increased glycolytic rate; (3) continued in some studies to acidify markedly during the first minute after exercise, indicating that glycolysis remained active into the recovery period; (4) had phosphocreatine and ADP recovery rates consistent with normal rates of oxidative phosphorylation. On the basis of these results, it was proposed that the patient suffers from a defect in Ca2+ handling in the muscle. Subsequently, direct measurement of Ca2+-ATPase activity in the sarcoplasmic reticulum fraction from a muscle biopsy sample showed that the activity of this enzyme was reduced by about 90%.

Adult↗