Biomedical subjects

H Kyle

Publications and source records attributed to H Kyle.

7 recordsLinked to original sources

PubMed1996

PEG--percutaneous endoscopic gastrostomy.

Percutaneous Endoscopic Gastrostomy is simply a plastic tube, placed in the stomach and passed through both the wall of the stomach and abdomen with the aid of a gastroscope, therefore avoiding the need for a laparotomy to form a gastrostomy. Egeberg proposed surgical gastrostomy in 1837. This was not carried out successfully until 1876 by Verneuil. The procedure, however, requires laparotomy and anaesthesia with its associated risks. The first gastrostomy without the need for a laparotomy is reported to have been performed in 1979 by Gauderer and Ponsky at Case Western Reserve University School of Medicine, Cleveland, USA. In 1980 they described the technique. Since then a variety of kits with which to perform the procedure have become available. PEG can be used for long term enteral nutrition or as an intermediate stage between Total Parentral Nutrition (TPN) and normal feeding. An important requirement is a successfully accomplished gastroscopy.

Enteral Nutrition↗

PubMed1990

Control of pH of airway surface liquid of the ferret trachea in vitro.

We measured the pH of airway surface liquid (ASL) secreted by the ferret trachea in vitro by using a catheter-tipped pH electrode implanted in a collecting cannula close to the airway epithelium. Mucus secretion was promoted by methacholine (0.02 mmol/l) in the organ bath. The pH of the ASL was 6.85 +/- 0.03 (SE) compared with a bath value of 7.39 +/- 0.01, when the bath was bubbled with 5.65% CO2. Changing the bath CO2 from 0 to 20.93% CO2 altered the bath pH from 8.06 to 6.96, but the ASL pH only varied from 6.92 to 6.85. This homeostasis of ASL pH was not the result of the buffering powers of the ASL, because ex situ buffer curves for secreted ASL were similar to those for Krebs-Henseleit solution. Changing the luminal CO2 content by blowing gases through the trachea changed ASL pH by values similar to that ex situ. However, when external organ bath CO2 was changed, the luminal CO2 changes were proportionately far smaller. Measurement of rates of diffusion of CO2 across the tracheal wall indicated that this was not a limiting factor in the results. Similarly, measurement of metabolic rate CO2 production in the tracheal lumen indicated that this did not significantly affect the results. We conclude that the pH of ASL is significantly on the acid side of the pH or interstitial fluid and plasma and that it is maintained relatively constant despite large changes in external pH.

Animals↗

PubMed1989

Electrolyte and other chemical concentrations in tracheal airway surface liquid and mucus.

With the ferret in vitro tracheal preparation, we measured the electrolyte and chemical composition of airway surface liquid (ASL) under control conditions and when drugs were added to promote submucosal gland secretion and to change epithelial ion transport. Control ASL was hyperosmolar (342 +/- 2.8 mosmol/kg) compared with ferret plasma and surrounding buffer. Higher values were also found for sodium (167 +/- 1.7 mmol/l), potassium (9.0 +/- 0.05 mmol/l), total calcium (3.46 +/- 0.11 mmol/l), and ionized calcium (2.55 +/- 0.18 mmol/l). pH was lower (7.12 +/- 0.03) than in plasma or buffer. Addition of methacholine to the surrounding buffer increased flow of ASL and potential difference across the mucosa and lowered pH, calcium, sodium, and chloride concentrations. Potassium concentration was increased. Phenylephrine increased flow and decreased calcium concentrations. Salbutamol (albuterol) had no effect on flow but decreased pH and increased calcium and potassium concentrations. Histamine increased flow and calcium concentrations and decreased pH. These changes are presumably due to changes in gland secretion and epithelial transport. Methacholine and phenylephrine increased the sugar content of the secretions, the changes with phenylephrine being larger. Thus resting ASL is hyperosmolar and relatively acid, with high cation contents, and administration of drugs changes its composition by actions on submucosal glands and epithelium.

Animals↗

PubMed1988

Comparison of mucus flow rate, radiolabelled glycoprotein output and smooth muscle contraction in the ferret trachea in vitro.

1. The concentration-response curves for rate of mucus output, labelled-glycoprotein output and smooth muscle contraction in response to methacholine, phenylephrine and salbutamol were determined in the ferret trachea in vitro. 2. The potencies of methacholine and phenylephrine are both in order: smooth muscle contraction, glycoprotein output, rate of mucus output. 3. At lower concentrations methacholine is more potent than is phenylephrine on smooth muscle contraction, glycoprotein output and rate of mucus output. 4. Concentration-response curves for salbutamol show very little change in rate of mucus output but a large increase in glycoprotein output. 5. It is concluded that the glycoprotein output induced by salbutamol may come from a source different from those induced by methacholine and phenylephrine.

Albuterol↗

PubMed1987

The effects of peptides and mediators on mucus secretion rate and smooth muscle tone in the ferret trachea.

The effects of a number of peptides and mediators were measured on the secretion rate of tracheal mucus and tracheal smooth muscle tone in the ferret in vitro whole trachea. The comparison of secretion rate and smooth muscle tone, measured simultaneously in the same preparation, shows that there are wide differences in sensitivity between the two systems; there appears to be no relationship between mucus volume output and smooth muscle contraction. The comparison of mucus secretion rate and glycoprotein output in other models and species to these drugs in the same concentrations indicates that there may be mucus glycoprotein output without an increase in volume output.

Animals↗

PubMed1987

Mucus secretion by tracheas of ferret and dog.

Mucus secretion, stimulated by nerve excitation or drugs, was measured from the ferret trachea in vitro by two methods: from the whole trachea, and compared with the volume of submucosal glands estimated from histological sections; and from mounted segments of trachea, by displacement of tantalum dust applied to the epithelium and compared with changes in tissue volume estimated by probing the epithelial surface between hillocks. Maximal secretion rates (2-3 microliters X min-1 X cm-2) with tracheal segments were 5-6 times greater per unit area than those with the whole trachea. During secretion the tissue shrank by a volume close to that of the secretion. Similar experiments with the hillock method and dog trachea in vivo gave variable results. Although the ferret submucosal glands can secrete 0.7-5.4 times their volume per minute, any change in tracheal resistance to airflow would be rather small.

Animals↗

PubMed1986

Quantitation of the secretory cells of the ferret tracheobronchial tree.

The tracheal epithelium of the ferret has few goblet cells while sero-mucous submucosal glands are present in large numbers throughout the length of the trachea and bronchi. The epithelium consists mainly of ciliated cells and of dark cytoplasmic non-ciliated cells that sometimes contain secretory granules. Any 'respiratory tract fluid' secreted into the ferret trachea is probably mainly glandular in origin. The epithelium contains neutrophils and a few mast cells and eosinophils. Nerve fibres are virtually absent from the epithelium, and this may be associated with a lack of the cough reflex from the ferret trachea. From a morphological point of view, the ferret trachea may well make a good model for the study of submucosal gland secretions.

Animals↗