Using a photometric method of measuring ciliary beat frequency, the effect of temperature on ciliary activity was investigated. A linear increase in ciliary beat frequency between 19 degrees and 32 degrees C was found. Between 32 degrees and 40 degrees a plateau was reached in which temperature did not significantly affect frequency and above 40 degrees C the frequency began to decline. It is concluded that nasal cilia are not critically dependent upon temperature in the range 32 degrees and 40 degrees C, the temperature range in which this tissue normally operates.
19 diabetic patients taking various doses of chlorpropamide were studied throughout a normal day. Plasma chlorpropamide levels were related to the daily dose of the drug and were relatively constant throughout the day. Blood glucose concentration was highest and the plasma insulin concentration lowest in patients taking the largest dose of chlorpropamide. Patients on a small daily dose of chlorpropamide were well controlled and had higher than normal insulin levels. --12 patients were restudied 10 days after stopping chlorpropamide. Although diabetic control deteriorated in all patients, plasma insulin concentration did not change significantly. This suggests that the long-term hypoglycaemic action of chlorpropamide is not dependent on an effect on the concentration of insulin in peripheral venous blood.
Patients with nasal polyposis complain of nasal blockage and rhinorrhoea, which may be due to impaired mucociliary clearance. The saccharine clearance time and ciliary beat frequency of samples of ciliated epithelium from patients with nasal polyps was measured. We also studied the effect of fluid from the oedematous stroma of nasal polyps and of histamine and prostaglandin (PG) D2, E2 and F2 alpha on the cilia from normal individuals. Polyp fluid was found to increase ciliary beat frequency. Histamine and PGD2 had no effect, but PGE2 and PGF2 alpha both increased ciliary beat frequency and so may cause the ciliostimulatory effect of polyp fluid. The saccharine clearance time was prolonged in three of nine patients, but ciliary beat frequency was only slightly reduced in one of these. Thus, where mucociliary clearance is reduced, it is likely to be due to abnormalities of mucus rather than impaired ciliary activity.
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