In the present study, we examined the independent and combined effects of an inspiratory muscle warm-up and inspiratory muscle training on intermittent running to exhaustion. Twelve males were recruited to undertake four experimental trials. Two trials (Trials 1 and 2) preceded either a 4-week training period of 1 × 30 breaths twice daily at 50% (experimental group) or 15% (control group) maximal inspiratory mouth pressure (PImax). A further two trials (Trials 3 and 4) were performed after the 4 weeks. Trials 2 and 4 were preceded by a warm-up: 2 × 30 breaths at 40% PImax. Pre-training PImax and distance covered increased (P < 0.05) similarly between groups after the warm-up (~11% and ~5-7% PImax and distance covered, respectively). After training, PImax increased by 20 ± 6.1% (P < 0.01; d = 3.6) and 26.7 ± 6.3% (P < 0.01; d = 3.1) when training and warm-up were combined in the experimental group. Distance covered increased after training in the experimental group by 12 ± 4.9% (P < 0.01; d = 3.6) and 14.9 ± 4.5% (P < 0.01; d = 2.3) when training and warm-up interventions were combined. In conclusion, inspiratory muscle training and inspiratory muscle warm-up can both increase running distance independently, but the greatest increase is observed when they are combined.

Fifty-eight patients with chronic asthma in whom airflow obstruction was relieved by bronchodilator aerosols but not by oral corticosteroids were compared with 58 other chronic asthmatics who responded equally well to both treatments. The two groups were matched for age and sex. The only significant clinical differences between the two groups were that in the "corticosteroidresistant" patients there was a more frequent family history of asthma and a longer duration of symptoms. Resistant patients also had a relatively lower peak expiratory flow rate in the morning than later in the day and a greater degree of bronchial reactivity to methacholine. Such features, however, may not be specific criteria of corticosteroid resistance since they were also observed in untreated asthmatics who subsequently responded well to corticosteroids. The failure of prednisolone to inhibit a monocyte-mediated bronchial reaction may explain why some chronic asthmatics do not respond to corticosteroids.Patients with corticosteroid-resistant asthma should be recognised at an early stage so that regular treatment with oral corticosteroids may be withdrawn. Failure to do this results in needless exposure to the risk of developing serious side effects.

This paper reviews work carried out at the National Engineering Laboratory, UK., related to pressure drop flow patterns and phase distribution on the shell-side of segmentally baffled shell-and-tube heat exchangers. The experimental work reported was carried out using air/water mixtures in model exchangers of rectangular cross section with tube nests containing approximately 40 tubes. Data were obtained on crossflow pressure drop and on the pressure drop attributable to the windows. In certain configurations the void fraction and flow pattern maps were obtained. The geometric conditions examined related to configurations appropriate to operation as condensers and boilers. Correlations for pressure drop and void fraction were developed and flow pattern maps obtained.

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