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Biomedical subjects

C Marriott

Publications and source records attributed to C Marriott.

At least 91 records · Page 5Linked to original sources
PubMed1981

Membrane damage by bile salts: the protective function of phospholipids.

The direct toxicity of sodium deoxycholate (SDC) and lysophosphatidylcholine (LPC) to biological membranes was assessed by measurement of goldfish overturn time. When phosphatidylcholine (PC) was incorporated into the aqueous media, the toxicity of both SDC and LPC was reduced, as indicated by increased overturn time. Fish were also pretreated for various times in media containing (a) 1 mM SDC and (b) 1 mM SDC with 1 mM PC. Subsequent transfer to solution, 100 mg litre-1 quinalbarbitone sodium showed that reciprocal overturn times for fish treated using method (a) increased linearly with duration of pretreatment up to a limiting value, obtained after 20 min exposure; 40 min exposure to 1 mM SDC was directly toxic. Fish pretreated using regimen (b) survived longer when challenged with barbiturate, and the reciprocal overturn times were a linear function of time of pretreatment up to at least 40 min. PC also provided protection against membrane damage caused by the synthetic surfactant sodium dodecyl sulphate. Mixed micelle formation between PC and surfactant is thought to account for the protective effects. The results are of significance in the consideration of reflux hypothesis for the aetiology of gastric ulceration and also the possible formulation of drug delivery systems intended to enhance absorption whilst minimizing gastrointestinal damage.

Absorption↗
PubMed1981

Isolation and partial characterization of a rheologically active glycoprotein fraction from pooled human sputum.

A rheologically active mucin fraction was isolated from pooled sputum and was shown to be free of any major protein contaminants. The procedure used allows the isolation to be carried out by a batch process so that sufficient material is available for extensive biochemical and biophysical studies. Because the separation was carried out using sputum, the purified material should prove suitable for the evaluation of drugs used in chronic obstructive airway disease. This paper describes the separation process in detail and the partial biochemical characterization of the mucin fraction.

Amino Acids↗
PubMed1981

The viscoelastic nature of mucus secretion.

The viscoelastic properties of mucus have been described together with the methods which can be used to evaluate such a rheologically complex system. Methods which do not take into account the viscoelastic nature of mucus have been criticized and it is concluded that only creep or oscillatory tests yield significant correlations with mucociliary clearance rates.

Animals↗
PubMed1980

The effect of mucolytic agents on the rheologic and transport properties of canine tracheal mucus.

The effect of several sulfhydryl and other agents on the rheologic and mucociliary transport properties of a model secretion, reconstituted canine tracheal mucus, was investigated. The mucus was obtained via the canine tracheal pouch. Rheologic properties were determined by mirorheometry, and the ciliary transport rate was determined using the frog palate technique. It was found that N-acetyl cysteine decreased the elastic modulus, leading to improved mucociliary transport at concentrations such that the mucin did not precipitate. S-carboxymethyl cysteine had no effect on either mucus properties or mucociliary transport rate, and its reported effectiveness in vivo must be due to some mechanism other than solubilization of mucin. Similar results were found with other blocked sulfhydryl compounds. Urea and potassium iodide to decrease mucus elasticity, but are harmful to cilia at the concentrations needed.

Acetylcysteine↗