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Biomedical subjects

L J Clancy

Publications and source records attributed to L J Clancy.

8 recordsLinked to original sources

The pathogenicity of Mycobacterium tuberculosis during chemotherapy.

We used the guinea pig as an experimental model to investigate the pathogenicity of Mycobacterium tuberculosis. Sputum samples were injected subcutaneously into guinea pigs and the animals were killed and an autopsy performed after eight weeks. The likelihood of the sputum samples producing tuberculosis in the guinea pig was related to culture positivity rather than to duration of chemotherapy. This study does not support the belief that a change in pathogenicity occurs during treatment of pulmonary tuberculosis.

Animals

Cellulitis in complicated pneumococcal pneumonia.

Serious complications of pneumococcal pneumonia have become uncommon. This has been attributed to decline in pneumococcal infection (van Roy et al. 1971; Foy et al. 1975), but in this country it is more likely to be due to effective antibiotic therapy. We report a case of pneumococcal pneumonia with severe complications (including a very unusual one) which probably arose through antibiotic failure.

Aged

Effect of intravenous infusion of salbutamol on ventilatory response to carbon dioxide and hypoxia and on heart rate and plasma potassium in normal men.

Intravenous infusion of salbutamol 10 mug/min in seven healthy subjects significantly increased their ventilatory responses to inhaled CO2 in both hypoxia and hyperoxia. These changes in chemical control of breathing are unlikely to be significant when the drug is used in severe asthma but may benefit patients with acute exacerbations of chronic ventilatory failure. The infusion also increased heart rate, which was most pronounced when hypoxia was combined with hypercapnia. The infusion produced an average fall in plasma potassium from 3-99 to 3-10 mmol/l, which was associated with an increase in plasma glucose and serum insulin, suggesting that this arose from a shift of potassium from the extracellular to the intracellular space. Routine monitoring of plasma potassium and the electrocardiogram is indicated when an intravenous salbutamol infusion is used to treat severe asthma as the drug may predispose to cardiac dysrhythmias.

Adult

Arterial blood gas tensions, hydrogen ion, and electroencephalogram during sleep in patients with chronic ventilatory failure.

We have studied arterial PO2, PCO2, and hydrogen ion and electroencephalogram during sleep in 10 patients with stable severe chronic respiratory failure. As a group the patients slept badly. Sleep was associated with a worsening of hypoxia and no significant change in PCO2 and H+. Two patients were restudied, receiving oxygen therapy overnight. Both had improved sleep but one, who had an intact hypoxic drive to breathing, developed marked hypercapnia and acidosis when his PO2 was restored to normal during sleep; the other, who had no hypoxic drive to breathing, developed no more hypercapnia or acidosis during sleep when breathing oxygen than when breathing air. Oxygen therapy may improve sleep disturbance in these patients, but its effect on the drive to breathing during sleep should be considered if severe hypercapnia and acidosis are to be avoided.

Carbon Dioxide

Arterial catecholamines in hypoxic exercise in man.

1. We measured the minute ventilation and arterial blood catecholamine concentrations in four normal men standing and at two levels of moderate treadmill exercise breathing 14% oxygen or air. 2. Minute ventilation was significantly higher during hypoxic exercise than during normoxic exercise at an oxygen uptake of 1500 ml/min. 3. Arterial plasma noradrenaline during hypoxic exercise at an oxygen uptake of 1500 ml/min was significantly greater than at rest. 4. Arterial plasma noradrenaline during normoxic exercise at an oxygen uptake of 1500 ml/min was not elevated above the resting concentration. 5. The results are compatible with the suggestion that increased concentrations of arterial plasma noradrenaline contribute to the hypoxic potentiation of the respiratory response to moderate exercise.

Adult