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R J Sapsford

Publications and source records attributed to R J Sapsford.

5 recordsLinked to original sources
PubMed1992

The effects of salmeterol and salbutamol on ciliary beat frequency of cultured human bronchial epithelial cells, in vitro.

Studies investigating mechanisms of mucociliary clearance have suggested that beta 2-adrenergic agents may significantly influence ciliary activity of epithelial cells and therefore play a vital role in the maintenance of functional integrity of the airways. We have cultured human bronchial epithelial cells, from surgical explants and investigated the effects of salbutamol and salmeterol, in a time- and dose-dependent manner, on the ciliary beat frequency (CBF) of these cells. Prior to and at several times after exposure to either salbutamol (10(-8) to 10(-3) M) or salmeterol (10(-8) to 10(-4) M), the epithelial cells were monitored for CBF and on the basis of data obtained from these studies, the effect of 10(-6) M propranolol was investigated in the presence of optimal concentrations of salbutamol and salmeterol. Salbutamol was optimally active at a concentration of 10(-4) M and caused a transient but significant increase in the CBF from baseline level of 8.6 +/- 0.4 to 9.6 +/- 0.5 Hz (P < 0.05), after 2 h incubation. In contrast, salmeterol was maximally active at a concentration of 10(-6) M and caused a significantly rapid and prolonged increase in CBF from a baseline value of 9.2 +/- 0.4 to 10.9 +/- 0.6 Hz (P < 0.02) and 10.6 +/- 0.8 Hz (P < 0.05) after 15 min and 24 h incubation, respectively. Propranolol (10(-6) M) abrogated the salbutamol- but not the salmeterol-induced increases in CBF.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1992

The effect of human eosinophils on cultured human nasal epithelial cell activity and the influence of nedocromil sodium in vitro.

Although there is increasing evidence of a pathogenic role for eosinophils in the airway epithelium, there is little direct evidence which demonstrates that eosinophils influence epithelial cell activity in humans. We have cultured human nasal epithelial cells in vitro and studied the effect of isolated human eosinophils on the ciliary beat frequency (CBF) and cell membrane integrity of these cells after incubation in the absence or presence of 0.1 microM phorbol 12-myristate 13-acetate (PMA) or 0.1 mg/ml opsonized latex beads and the absence or presence of 10(-5) M nedocromil sodium. CBF was monitored by an analogue contrast-enhancement technique, and cell damage was assessed by release of 51Cr from the cells. Cell cultures were also assessed for the percentage of eosinophil cationic protein (ECP) released into the medium at the end of incubation. Neither 0.1 microM PMA, 0.1 mg/ml opsonized latex beads, 10(-5) M nedocromil sodium, nor eosinophils alone altered the CBF of the epithelial cells. PMA-stimulated eosinophils, however, attenuated the CBF significantly, from 10.2 +/- 0.3 to 8.8 +/- 0.4 Hz (P less than 0.05) after 15 h of incubation. Similarly, opsonized latex bead-stimulated eosinophils led to a significant attenuation of CBF from 9.2 +/- 0.3 to 8.4 +/- 0.3 Hz (P less than 0.05), 6.9 +/- 0.5 Hz (P less than 0.001), and 7.5 +/- 0.3 Hz (P less than 0.001) after 2, 15, and 24 h of incubation, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1990

Culture and comparison of human bronchial and nasal epithelial cells in vitro.

Human nasal and bronchial epithelial cells were cultured in vitro and compared morphologically and functionally. Morphologic assessment by both light and electron microscope and indirect immunoperoxidase staining techniques confirmed the identity of the two cell types as being epithelial. Light microscopy of confluent cultures revealed tightly packed cell monolayers, whilst electron microscopy showed that cells were linked by tight junctions. Estimation of cell size by planimetry found these cells to have a mean width of 10.6 +/- 1.1 microns for nasal cells and a mean width of 10.2 +/- 1.0 microns for bronchial cells. A high proportion of both the nasal and the bronchial cells exhibited features of the mature ciliated cell types, and constituted between 50 and 76% of the total cells at the earlier stages of culture although this decreased to between 16 and 23% of the total by 4 weeks in culture. The ciliary beat frequencies of the nasal and bronchial cells were found to be similar at 10.8 +/- 0.7 Hz and 11.8 +/- 2.3 Hz, respectively. The cilial beat on adjacent cells was synchronous, suggesting the presence of intercellular communication between the neighbouring cells. These studies demonstrated that there was little difference between the cultured nasal and bronchial epithelial cells with respect to either their morphology or ciliary activity.

Bronchi↗
PubMed1979

Lactase degradation by human enteric bacteria.

Twelve non-pathogenic bacteria and two yeast strains isolated from the duodenal aspirate or mucosa of five children with diarrhoea were tested for their ability to degrade non-human lactase in vitro. Both yeast strains and eleven of the bacterial strains significantly reduced lactase activity. A similar action on human lactase could be a cause of lactose intolerance.

Bacteria↗