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Biomedical subjects

D E Gunson

Publications and source records attributed to D E Gunson.

28 records · Page 2Linked to original sources
PubMed1979

The role of allergy in chronic pulmonary disease of horses.

Twenty-five horses with chronic pulmonary disease were skin tested with allergenic extracts of 24 molds, 4 thermophilic actinomyces, barn dust, hay dust, soya-bean mill dust, and grain mill dust. The results were compared with those obtained on 25 normal horses. Between the 2 groups of horses, there was a highly significant difference in positive skin test results at 30 minutes and 4 hours.

Acremonium↗
PubMed1979

Collagen in normal and abnormal tissues.

Despite being a very widespread protein, collagen is an unusual molecule possessing a great tensile strength conferred by a rope-like structure and intermolecular crosslinks. Our current knowledge of the biosynthesis of collagen is providing some insights into certain diseases of connective tissue and is also helping us to understand the healing processes of wounds and diseased tissues.

Animals↗
PubMed1977

Branchial cyst in a heifer.

A branchial cyst in a heifer was removed surgically. Diagnosis was based on clinical signs, analysis of cyst contents, and histologic examination of the cyst wall. Biochemically, the cyst fluid resembled a transudate. The cyst lining consisted of nonciliated, pseudostratified columnar epithelium and pigmented, keratinized, stratified squamous epithelium. The embryologic origin was thought to be endoderm of the 2nd pharyngeal pouch and adjacent ectoderm.

Animals↗
PubMed1977

Anaphylactoid purpura in a horse.

An 8-year-old gelding with a long-standing, streptococcal respiratory infection developed dyspnoea and colic. Laparotomy disclosed numerous, discrete, hemorrhagic, thick areas of necrosis throughout the intestinal tract. At postmortem examination similar lesions were seen in the laryngeal mucosa and in many skeletal muscles. Microscopically these lesions had massive necrosis and hemorrhage with a leucocytoclastic vasculitis in adjacent tissue. This condition resembled anaphylactoid purpura (Henoch-Schönlein disease) in man. Fungal infection was ruled out by special stains which failed to show fungal elements.

Animals↗
PubMed1976

Rat parietal yolk sac basement membrane. An investigation of the antigenic determinants using a radioimmunoassay.

Previous studies have shown that there is microscopic and biochemical evidence that rat parietal yolk sac synthesizes basement membrane (type IV) collagen; this study shows that a radioimmunoassay may be used for the detection of type IV collagen in such biosynthetic systems. Rat parietal yolk sacs incubated in medium containing (14C) proline either with or without alphaalpha-dipyridyl produced either unhydroxylated or hydroxylated (14C)collagen. The immunological reactivity of these two preparations was investigated using antibodies to bovine type IV collagen in a radioimmunoassay which demonstrated that the hydroxylated (14C)collagen preparation had a considerably higher level of antigenicity than the unhydroxylated (14C)collagen. Hydroxylated rat type IV (14C)collagen which had been reduced and alkylated was intermediate in antigenicity between hydroxylated and unhydroxylated material. These findings suggest that there are antigenic determinants which depend upon hydroxylation of the collagen molecule, and others dependent upon intact disulphide bonds. In addition, various levels of pepsin extracted unlabelled calf anterior lens capsule collagen caused inhibition of antibody binding to (14C)collagen. Rat type IV (14C)collagen which had been digested with collagenase was inactive in the radioimmunoassay, while pepsin digestion caused no reduction in antigenicity. These findings suggest that the antiserum is directed towards the collagenous part of the molecule and may be a useful tool in the detection of biosynthesized basement membrane collagen.

Alkylation↗
PubMed1976

The role of hydroxylation of proline in the antigenicity of basement membrane collagen.

Rabbit antibodies to bovine basement membrane collagen were used to compare the antigenic determinants of rat parietal yolk sac basement membrane [14C]procollagen with [14C]protocollagen. Basement membrane [14C]protocollagen was found to be less antigenic than basement membrane [14C]procollagen. Hydroxylation of basement membrane [14C]protocollagen, either intracellularly or in vitro with protocollagen prolyl hydroxylase, resulted in restoration of antigenicity. The difference in antigenicity observed between basement membrane [14C]procollagen and basement membrane [14C]protocollagen appeared to depend primarily upon the presence of hydroxyproline in the collagen molecule. Glucosylgalactosylhydroxylysine was found to be unimportant for antigenicity.

Animals↗
PubMed1976

The use of the radioimmunoassay in the characterization of antibodies to basement membrane collagen.

This study describes the use of the radioimmunoassay for the characterization of antibodies to basement membrane (type IV) collagen from bovine anterior lens capsule. The immunogen was extracted from calf anterior lens capsules by limited pepsin digestion and injected into rabbits. The antisera were characterized using gel diffusion, haemagglutination and the radioimmunoassay in which 125I-labelled types I, II, III, and IV bovine collagen were employed. In the direct radioimmunoassay there was no reaction with either native or denatured types I, II or III bovine collagen, whereas there were high titres towards both native and denatured type IV bovine collagen. Radioimmune inhibition studies using unlabelled types I, II, III and IV bovine collagen, collagenase digested and repepsinized type IV collagen showed that there was marked inhibition by either native, denatured or repepsinized type IV collagen, and slight inhibition by native type I collagen; native type II and type III, denatured types I, II and III, and collagenase digested type IV collagen had no inhibitory effects.

Amino Acids↗