Fifty three individual gastric aspirations were eluted on Bio-gel PI50. Improved methods of separation and analysis provided a tolerably pure non-retarded fraction. The carbohydrate component showed a basic structure common to all glycoproteins comsposing the non-retarded fraction. It showed the following quantitative relationship: Galactose : Glucosamine : Galactosamine

Gel chromatography on Sephadex G150 or Bio-gel P150 resolved the gastric secretions into three fractions. The non-retarded fraction contained 70–90% of the total carbohydrate eluted in the three fractions. The gastric secretions before gel filtration and the non-retarded fraction contained the same carbohydrate residues and the three carbohydrate components, galactose, glucosamine and galactosamine, in the same quantitative proportions. The amino-acid composition of the non-retarded fraction showed marked similarities and characteristic quantitative relationships. Threonine and serine were found to constitute 45–50% of the total aminoacid content. The analytical data, ultracentrifugation and light scattering studies suggest that the non-retarded fraction is composed of macromolecules which have a common basic composition but which are polydisperse with reference to their charged end groups, fucose and size.

1. The sugars and amino sugars of hydrolysates of gastric secretion were determined by gas-liquid chromatography. 2. All the gastric aspirations examined showed on hydrolysis the presence of fucose, galactose, mannose, glucose, galactosamine, glucosamine, N-acetylneuraminic acid and sulphate. 3. Galactose and glucosamine were always found in equimolar amounts, but the galactose/galactosamine ratio in different aspirations was 2:1, 3:1, 4:1 or 5:1. Repeated gastric aspirations of each subject examined showed constant ratios of these carbohydrate components. 4. Fucose and sialic acid appear to be related to glucosamine and galactosamine respectively. 5. The carbohydrate components of extracts from the mucous glands of the body mucosa and antrum did not differ from those of gastric secretion.

The chemical composition and function of gastrointestinal mucus Despite the long period in which gastroenterologists have been interested in mucus, few exact data and little precise information on this substance have been, until recently, available, due mainly to the lack of reliable procedures to isolate the components of mucus in a tolerably pure state, to determine their composition, and to study their structure. The unique rheological properties of mucus, such as gelation, film formation, adhesiveness, and non-Newtonian viscosity, are intimately related to the chemical composition and structure of its components and the forces which mould them into the elaborately organized three-dimensional structure of mucus. It is also reasonable to suggest that the physical properties are intimately associated with the biological function of mucus. It follows, therefore, that a rational understanding of the function of mucus has to be based on a thorough knowledge of the composition and structure of this substance. Electrophoresis and ion exchange methods used so successfully in the study of proteins were not helpful in separating and purifying the components of mucus. The biocolloids which constitute mucus do not lend themselves easily to electrophoresis. The concentration at which the initial band has to be applied to the paper is so high that the glycoprotein is itself a gel-like structure forming a visco-elastic network and therefore is not easily and uniformly manoeuvred by electrophoretic forces. Ion exchange resins are also unsuitable, as will be shown later. The absence of exact quantitative methods to determine each of the carbohydrate components of mucus add to the difficulties. The commonly used methods involve non-specific colour reactions with various phenols in concentrated sulphuric acid but do not distinguish between the monosaccharides and are of limited use in estimating each sugar residue of the carbohydrate moiety of the components of gastric mucus. Recent technical advances, especially the use of gas-liquid chromatography, to determine the sugar residues of complex mixtures, provide methods which, for the first time, have made possible the isolation of the components of mucus and their detailed study. Gas-liquid chromatography is based on the work of Sweeley6, and the method and technical details have already been reported.. The exact quantitative estimation of micrograms of each carbohydrate residue of the mucus is well within the reach of this method, and has made possible the determination of each sugar and amino sugar of hydrolysates of single, small (5 ml) gastric aspirates. A preliminary investigation was designed to find means of disrupting the structure of mucus but retaining its components intact, and of selecting a fractionation procedure which would isolate the liquefied mucus into its components. A suspension of mucus in a saturated solution of calcium chloride or 8 M urea was shown to liquify the mucus, and liquefied mucus, when eluted on a gel column, was resolved into well separated com

EDITORIAL COMMENT In this histological study of surgical specimens it has been shown that duodenal ulcer is associated with mild inflammation and gastric ulcer with marked changes and degeneration with metaplasia.Very few detailed descriptions of the antrum are available in the literature, yet the importance of this organ has been stressed by many writers in the past (Konjetzny, 1928;Faber, 1935;Hebbel, 1943; Magnus, 1954;Dean and Mason, 1964; and others). An attempt has been made in this laboratory to study the gastric antrum in normal stomachs and in duodenal and gastric ulcer in greater detail. METHODSOne hundred and thirty specimens were examined. Seventy-five of these were surgical specimens from cases of duodenal ulcer and 40 from cases of gastric ulcer. Sixteen were from post-mortem specimens removed within a few hours of death, in which as far as could be ascertained, there was no question of gastrointestinal disease. The surgical specimens were opened immediately after operation by cutting along the greater curvature and they were pinned out with care on cork mats. They were formalin fixed immediately. The specimens with duodenal ulcer had a cuff of duodenum some 5 cm. in width. The amount of duodenum in gastric ulcer specimens was much reduced, but all the specimens showed an intact sphincter. The proximal portion of the specimen consisted of gastric mucosa.After fixation, the specimens were photographed. The size of the photograph was exactly the same as the size of the stomach. A tracing was made from the photograph onto thin paper. The whole of the specimen was cut into longitudinal strips 1-Ij cm. broad. Transverse cuts were then made through the strips at three places, the result being 30-40 shorter pieces measuring approximately 6 cm. in length. A plan of these cut strips was made on the tracing from the stomach. The strips were numbered and these numbers entered on the plan. The strips were then processed, blocked in wax, and sectioned on a sledge microtome. The boundary between the antrum and the body mucosa was studied and mapped out and the surface area of the antrum measured with a planimeter. This procedure enabled us to study thoroughly all of the gastric mucosa and get acquainted with the whole of its cellular topography.The stains used in this study were haematoxylin and eosin and Zimmerman's stain using the method described by Marks and Drysdale (1957); also 30 specimens were stained with Van Gieson stain. The Zimmerman stain was used to show up well the parietal, peptic, and mucous cells. The Van Gieson stain was used to show the increase in fibrous tissue in the mucosa and submucosa. RESULTS CLASSIFICATION OF THE INFLAMMATORY CHANGES Theinflammatory changes in the antral mucosa were classified as follows: 1 Changes showing inflammatory reaction and no destruction of pyloric glands, and according to severity, divided into grades Al and A2 (Figs. 1 and 2); 2 changes resulting in damage and destruction of the pyloric glands with increasing amounts of intestinalization. The final stage s...