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Biomedical subjects

B K Wignall

Publications and source records attributed to B K Wignall.

10 recordsLinked to original sources
PubMed1994

Collateral ventilation and gas exchange in emphysema.

Resistance to collateral flow of gas is high in the normal human lung but may be lower in emphysema. However, the contribution of collateral ventilation to gas exchange in emphysema remains unclear. This study evaluates the role and magnitude of collateral ventilation between bronchopulmonary segments in six patients with clinical, functional, and computed tomographic evidence of emphysema, compared with our previous findings in 12 normal subjects. To assess collateral flow, a balloon-tipped catheter with a lumen that opened distal to the balloon was inflated in segmental bronchi during fiberoptic bronchoscopy. Respiratory gas tensions were sampled by mass spectrometer from beyond the occlusion via the catheter lumen. Subjects breathed air until occlusion was established and then switched to 79% helium/21% oxygen. The rate of rise of helium concentration was measured within occluded segments and used as an index of collateral ventilation. The mean (+/- SEM) rate of rise of helium concentration was ten times greater in emphysema patients (9.5 +/- 2.7%/min) compared with normal subjects (0.8 +/- 0.3%/min) (p = 0.009). The mean PO2 within occluded segments was similar in normal subjects and emphysema patients: 45.4 +/- 1.8 mm Hg and 44.8 +/- 3.6 mm Hg, respectively. Mean PCO2 within occluded segments was lower in patients (40.1 +/- 1.9 mm Hg) than in normal subjects (46.4 +/- 1.3 mm Hg), probably due to higher regional ventilation-perfusion ratios in emphysema patients rather than collateral ventilation. In emphysema patients there was a positive correlation between rate of rise of helium concentration and final PO2 within an occluded segment (r = 0.73; p = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1982

Mortality of female gas mask assemblers.

A 30-year follow-up study of the mortality of 500 women employed in manufacturing gas masks during the second world war showed a pronounced excess of deaths from mesothelioma and lung cancer. Although these women were subject only to short periods of exposure, greater excesses were found for those exposed for between one and five years than for those exposed for under one year. Even in the latter group, however, five deaths from lung cancer and four deaths from mesothelioma were recorded compared with 1.5 deaths and 0.1 deaths expected (p approximately equal to 0.02). An excess of deaths from cancer of the ovary was also found, and this appeared to be related to exposure to asbestos.

Adult↗
PubMed1980

The chest X-ray in quadriplegia: a review of 119 patients.

Chest X-rays of 119 quadriplegic patients were reviewed. The unusual findings were rib erosions and ossification of the coracoclavicular ligaments. It is suggested that pressure from the scapula is likely to be responsible for the erosions but the cause of ossification in the ligaments remains conjectural.

Adult↗
PubMed1980

Rationalising abdominal radiography in the accident and emergency department.

A retrospective analysis is presented of 100 consecutive patients attending an accident department and referred for abdominal radiography. In general the reasons for requesting supine films appeared sound. Five per cent of referrals were for haematemesis which is not a valid reason for plain radiography. An erect abdominal film as a routine request is indicated only in suspected intestinal obstruction (4% in this series), but 83% of patients were referred for both erect and supine films. If haematemesis were excluded as a reason for X-ray referral, and if erect films were limited to suspected intestinal obstruction, 95% of the patients would still have been referred for radiography, but almost half the abdominal films would not have been required. This would have reduced film wastage, workload and more important, gonadal irradiation.

Adolescent↗
PubMed1980

The consequences of exposure to asbestos dust in a wartime gas-mask factory.

This further study of wartime gas-mask workers who were exposed to asbestos dust has shown that among those who worked with crocidolite there is a considerable excess of cases of mesothelioma, a more modest excess of bronchial carcinoma, but no excess of any other type of malignant disease. A dose-response relationship is established in the mesothelioma and bronchial carcinoma patients. It is not possible to base any conclusions on the limited data available for the small number of people exposed to chrysotile for a maximum period of five months. We believe that the identification and measurement of fibres in autoptic lung tissue from patients with accurately known occupational histories of asbestos dust exposure is useful, and a similar study on a population exclusively exposed to chrysotile would be of considerable interest.

Asbestos↗
PubMed1977

Pneumoperitoneum: the misleading double wall sign.

Both sides of the gut wall seen on a plain film of the abdomen is regarded as evidence of free air in the peritoneal cavity. However, this appearance may be precisely simulated when two loops of distended intestine lie in contact with each other. In vitro studies and clinical examples emphasise the necessity of exercising caution when making the diagnosis of pneumoperitoneum on this sign alone.

Abdomen, Acute↗
PubMed1977

The radiology of nasal injuries: problems of interpretation and clinical relevance.

Films of 50 normal patients and 50 dry skulls were examined to detect lines which might stimulate a nasal fracture. These were visible on the occipito-mental view but on the lateral view any line which reaches the anterior cortex must be regarded as a fracture. The results of an analysis of 100 patients with trauma to the nasal bone are also presented. It is concluded that radiography of the nasal bone is an unnecessary examination unless requested by the E.N.T. surgeon, and this will in any case occur infrequently.

Fractures, Bone↗