Expression of the VLA family of integrins in human intestine

The distribution of cells expressing the integrins VLA-1 to 6 in human intestine was examined by alkaline phosphatase immunohistochemistry using monoclonal antibodies specific for the individual alpha-chains of the VLA heterodimer. VLA-2,3, and 6 were expressed on all epithelial cells in the small and large bowel. VLA-1 was expressed on crypt cells in the small and large bowel, but was only weakly expressed or was absent on villus epithelial cells in the small bowel and colonic surface epithelial cells. All epithelia were negative for VLA-4 and VLA-5. Intraepithelial lymphocytes were VLA-1+ and VLA-4+. VLA-1,3, and 5 were expressed uniformly by muscularis propria, muscularis mucosae, pericrypt cells, and smooth muscle fibres within the villi. By contrast, VLA-2 and 4 were present only in pericrypt cells and fibres within the villi; they were absent from the muscularis mucosae. VLA-1,3,5, and 6 were expressed by endothelium. Staining of muscle fibres and endothelium in the lamina propria made it difficult to determine the extent of VLA expression on lamina propria lymphocytes. However, VLA-1+ cells with lymphoid morphology were only rarely seen. All mononuclear cells in the lamina propria were VLA-4+.

Incidence of the circadian rhythm of the excretion pattern on acetate absorption and metabolism in the rabbit hind-gut

Acetate absorption in the hind-gut of anaesthetized rabbits was evaluated by measuring variations in the concentration of acetate in caecocolonic loops and in arterial and venous plasma. In vivo metabolism in gut and liver tissues was studied using [1-14C]acetate. Interrelations between acetate absorption and metabolism and both phases of the excretory cycle of the rabbit were examined. The disappearance rate from the caecocolonic loop was quantitatively significant. The gut tissue metabolized acetate, and the intensity of utilization varied with the segment studied; the distal position of the large intestine showed by far the highest uptake of short-chain fatty acids (SCFAs). In addition, acetate absorption, like its metabolism in the hind-gut and liver tissues, differed in intensity according to the phase of the excretory cycle, i.e., both mechanisms were enhanced during hard faeces production. Radioactivity was found in free amino acids, organic acids and sugars. Irrespective of the location in the gut and the excretion pattern, acetate was rapidly converted into glutamate and aspartate; these nutrients were subsequently diverted towards either oxidative metabolism or biosyntheses (non essential free amino acids, proteins).

Extracellular deposit of the cationic proteins ECP and EPX in tissue infiltrations of eosinophils related to tissue damage

In a series of eosinophil inflammatory states affecting various organs (heart, gut, bladder and skin) we performed an immunohistochemical study of the eosinophil cationic proteins ECP and EPX. A strong correlation was noted between the liberation of ECP and EPX and tissue necrosis in all organs. In most cases ECP and EPX were found on the same location. However, one case indicated a possible differential release. Extracellular ECP and EPX were revealed concurrently with the two polyclonal antibodies and the monoclonal EG2 antibody. The latter binds to both ECP and EPX, but only during secretion. Since EG2 does not differentiate between ECP and EPX, but only during secretion. Since EG2 does not differentiate between EXP and EPX, it is for the first time demonstrated that both cationic proteins are correlated to tissue damage. The chymotrypsin-like cationic protein (CCP), related to neutrophils, showed a low correlation with the eosinophil cationic proteins in cases of tissue damage. The hypothesis is put forward that the release of eosinophil granule proteins and especially ECP results in a non-specific tissue damage.

Structurally distinctive vasoactive intestinal peptides from rat basophilic leukemia cells

Peptides recognized by rabbit antibodies to vasoactive intestinal peptide (VIP) were extracted from diisopropyl fluorophosphate-treated rat basophilic leukemia (RBL) cells and resolved by filtration on Sephadex G-25 in 50 mM acetic acid. The immunoreactive VIPs of RBL cells eluted from Sephadex G-25 at 35-41%, 53-60%, and 69-73% bed volume, but not at 63-68% as for the neuropeptide VIP1-28. The two forms of immunoreactive VIP larger than VIP1-28 reacted with antibodies to both VIP1-9 and VIP10-28, but the smallest was bound only by antibodies to VIP10-28. The smallest immunoreactive VIP was purified by ion-exchange and reverse-phase high-performance liquid chromatography, and the amino acid sequence was determined to be that of VIP10-28 with asparagine-free acid at the carboxyl terminus rather than the amide of VIP neuropeptide. Challenge of RBL cells with 1 microM ionophore A23187 at 37 degrees C released VIP10-28 rapidly to a mean of 75% at 5 min and 77% at 30 min. The VIP generated and released by mast cells thus consists of a mixture of peptides that all differ structurally from the neuropeptide VIP.

Expression of brush border calmodulin-binding proteins during human small and large bowel differentiation

The expression and immunocytochemical localization of three brush border cytoskeletal calmodulin-binding proteins, caldesmon, fodrin, and the 110 kDa subunit of the 110 kDa calmodulin complex, have been studied in human intestinal epithelial cells as a function of their ontogenic differentiation. At immature stages (fetal week 8), caldesmon and fodrin were present in undifferentiated intestinal epithelial cells. However, no 110 kDa protein was detectable except a 135 kDa immunoreactive species. The 110 kDa form appeared at week 12, when microvilli differentiate, and became prominent at week 14 simultaneously with the disappearance of the 135 kDa species. Finally at week 14, the calmodulin-binding protein pattern was identical to that found in adults. Immunocytochemical experiments revealed that at week 8, antibodies to caldesmon and fodrin gave a fluorescence lining at the periphery of the cells, whereas the 110 kDa immunoreactive species was hardly detectable. Then, as early as week 12 of gestation, with the three antisera, a bright fluorescence lined the apex of the cells, as in adults. In the colon, the events were delayed. This study demonstrates that the developmental pattern of the three calmodulin-binding proteins investigated, caldesmon, fodrin and the 110 kDa subunit, parallels the temporal differentiation of human intestinal brush borders and the proximo-distal morphological intestinal maturation.

[Localization of glycoconjugates in tissues of mammals revealed by means of labeled lectins]

Histochemical peculiarities on binding of castor-oil plant, soybean and lentil lectins with tissues of the mucous membrane in the stomach, small and large intestine have been studied in the human being, rat, mouse, as well as the lectins mentioned and the maize agglutinin with the nervous tissue of the rat cerebral tissue. The reactions are carried out with nonfixed cryostat and deparaffinized histological slices. Lectins labelled with horseradish peroxidase are used. Certain specific peculiarities and differences concerning the lectin binding with tissues of the organs studied are determined. Predominant binding is noted of the soybean lectin with parietal and mucin-producing cells of the stomach, with epitheliocytes of the duodenal glands, with the brush border of the epithelial cells of the intestinal villi. The lentil and castor-oil plant lectins make contours of the basal membrane epithelium in the stomach and intestine. The lentil lectin also reacts with the germinative centers of the stomach lymphatic nodules and the castor-oil plant agglutinin--with the brush border of the small intestine epitheliocytes. The lectins used are predominantly bound with neurons of the subcortical formations of the rat brain and cerebral cortex. By means of labelled lectins of lentil, soybean, and castor-oil plant it is possible to reveal certain modifications of the rat small intestine glycoconjugates produced by means of the immortelle extract.

Immunohistochemical distribution of hepatic fatty acid-binding protein in rat and human alimentary tract

Tissues from rat and human alimentary tract were immunostained with rabbit antibodies to fatty acid-binding protein (FABP) isolated from rat liver, since the precise immunohistochemical localization of the protein in gut has not been determined. The results obtained indicated that FABP immunoreactivity was found almost exclusively in intestinal absorptive cells, the sole exception being its presence in the cytoplasm of a few goblet cells. In small bowel, FABP-positive cells were most often found in the upper and middle segments, and less frequently in the lower to terminal portion. Immunoreactive cells were also found in large bowel of rat and human, but with differing patterns of distribution. In rat, positive cells were found mainly in the lower portion of the large intestine, whereas in human positive cells were present in all portions. Immunoreactive cells were detected in rat and human cecum, in the upper half of human rectum, and in human vermiform appendix. No such cells were found in esophageal and nonmetaplastic gastric mucosa or in pancreatic tissue, whereas they were present in great numbers in metaplastic gastric mucosa. The results of this study therefore suggest that FABP is a useful marker for research into the physiology or pathology of absorptive cells in the gastrointestinal tracts of both species.

Histochemistry of mucins of pig intestinal secretory epithelial cells before and after weaning

Two histochemical staining techniques, Alcian blue/PAS and high-iron-diamine/Alcian blue, which differentiated neutral from sulphated and sialylated acid mucins were applied to sections of duodenum, ileum, caecum, colon and rectum from pigs aged one day, 3 weeks and 10 weeks. In each age group, sulphated-acid mucins predominated at all sites, particularly in the large intestine. In both the small and the large intestine, non-sulphated mucins occurred mainly at the bases of the crypts. Neutral mucins occurred in a few goblet cells in crypts and villi, either alone or together with acid mucins; neutral mucins increased away from the bases of the crypts. No changes were noted in the caecum, colon or rectum of pigs one, two, 5 or 13 days after weaning onto a diet containing soya protein. In the small intestine, there was a transient increase in the numbers of goblet cells in the crypts and villi, a relative increase in sulphated and a decrease in non-sulphated acid mucins and a change in the distribution of sulphated mucins in the crypts. No change in proportions of neutral and acid mucins was detected.

A histochemical study of the mucins in the digestive tract of the chicken

Little is known about the distribution of glycoproteins in the digestive tube of birds. In the present study, the localization and distribution of mucins in the digestive tract of the chicken are reported. Sialo- and sulpho-mucins were widely distributed throughout the chicken digestive tube. Some of the mucous cells of the proximal segment of the proventriculus presented neutral glycoproteins; in the medial segment, surface cells containing only sialo-mucins were observed. Surface cells of the gizzard contained both sialo- and sulpho-mucins while PAS-positive material was localized in the lumen of the glands. 2 types of mucous cells were observed in the small intestine; 1 type contained only sialo-mucins and the other contained both sialo- and sulpho-mucins. In the large intestine and caecum, both types of acid mucins were present in the mucous cells. In conclusion, the distribution of glycoproteins in the chicken reported in the present study show marked differences with that reported in other avian species.

The mono- and difucosyl blood group B glycosphingolipids of rat large intestine differ in type of core saccharide

Two blood group B-active glycosphingolipids were isolated from rat large intestine and characterized by mass spectrometry, proton NMR spectroscopy and methylation analysis. The following structures were concluded: Gal alpha 1----3(Fuc alpha 1----2)Gal beta 1----3GlcNAc beta 1----3Gal beta 1----4Glc beta 1----1Cer and Gal alpha 1----3(Fuc alpha 1----2)Gal beta 1----4(Fuc alpha 1----3)GlcNAc beta 1----3Gal beta 1----4Glc beta 1----1Cer. The two glycolipids thus differ in their core saccharides (type 1 and type 2 chain, respectively) and therefore must have different pathways for biosynthesis.

Lectin reactivity in human large bowel

The affinity of six lectins (Arachis hypogaea, Concanavalin A, Bandeiraea simplicifolia I. Dolichus biflorus, Triticum vulgaris and Lotus tetragonolobus) was studied in 10 normal human large intestines. The results showed that each lectin had its own characteristic staining pattern. They differed in their affinity for different cellular components, local distribution within crypts and regional distribution between right (ascending colon) and left (rectum) segments of the large bowel. Arachis hypogaea stained predominantly the supranuclear golgi cisternae and Concanavalin A the cytoplasm. Triticum vulgaris stained preferentially the mucin of the well differentiated cells of the upper crypt while Lotus tetragonolobus characteristically stained the glycocalyx and apical portion of the less differentiated basal cells of the lower crypt. Goblet-cell mucin of the ascending colon had greater affinity for Bandeiraea simplicifolia I and that of the rectum for Triticum vulgaris. Lotus tetragonolobus stained more frequently and extensively the goblet-cell mucin of the upper crypts of the ascending colon than that of the rectum. The goblet cell mucins of the upper crypts were consistently stained in both the right and left segments of the large bowel by Dolichus biflorus while the mucins of the less differentiated cells of the lower crypts were less consistently stained in the ascending colon.

Morphological and histochemical changes in intestinal mucosa in the reserpine-treated rat model of cystic fibrosis

The present investigation was undertaken to determine whether or not there are histochemical and morphological changes in the intestine of the chronically reserpine-treated rat, an animal model of cystic fibrosis. Male Sprague-Dawley rats were given seven daily intraperitoneal injections of reserpine at dosages of 0.5 (n = 6) or 1.0 mg/kg body weight (n = 6). Control groups consisted of parfed solvent-injected (n = 6), solvent-injected (n = 4), and saline-injected animals (n = 4). Light microscopic histochemical procedures and morphological assessments were performed on sections of "Swiss rolls" of small and large intestine. Chronic reserpine treatment caused an increase in the sulfation of goblet cell mucin in the small intestine without accompanying morphological change; these findings resemble those reported in cystic fibrosis. No qualitative differences in mucin were found in the large intestine but there was an increased number of goblet cells in the surface epithelium and retention of mucus within these cells. Similar although less marked changes were noted in the parfed controls suggesting that those observed in the treated groups may be due, in part, to the reserpine-induced anorexia. The resemblance between the changes in the small intestine of the reserpine-treated rat and those observed in CF patients supports the contention that the chronically reserpine-treated rat is suitable as a model of cystic fibrosis.

Distribution of the 10,000 molecular weight calcium binding protein along the small and large intestine of man

The distribution of the 10,000 molecular weight calcium binding protein along the human small and large intestine was studied using an enzyme linked immunoadsorbent assay. Small intestinal mucosal samples were obtained from the duodenal bulb, the second and third part of the duodenum and at about 50 cm intervals from jejunum and ileum of five whole small intestines of necro-kidney donors. Mucosal samples of caecum, colon ascendens, and transversum were also investigated. The amount of calcium binding protein per milligram of cytosolic protein increased throughout duodenum to reach the maximum in the proximal segment of jejunum and then declined steadily to nearly undetectable levels in ileum. In the colon no 10,000 molecular weight CaBP was detectable. The distribution of CaBP along the small and large intestine of man is thus parallel to the efficiency of the active calcium absorption of human intestine.

Elevation of the large bowel histamine concentration by aminoguanidine induced diamine oxidase inhibition

In inflammatory diseases of the large bowel a reduced diamine oxidase activity was found which may be related to a reduced oxidative degradation of histamine. An experimental inhibition of diamine oxidase could therefore influence the large bowel histamine concentration. The diamine oxidase inhibitor aminoguanidine was administered to rats in a single dose of 100 mg/kg orally, i.v., or i.p. A rapid increase of the concentration of the drug in the large bowel was measured (half-life = 2-5 h). During chronic amino-guanidine administration (3 times/week, 100 mg/kg orally) the large bowel histamine increased by 30% on average. This may be sufficient for a proliferative stimulus of the intestinal mucosa. Previous reports of an increase of body weight of animals and of patients under aminoguanidine treatment could not be confirmed by our study.

Distribution of enteroglucagon- and polypeptide YY-immunoreactive cells in the gastrointestinal tract of the white-belly opossum (Didelphis albiventris)

Several segments of the gastrointestinal tract of the white-belly opossum Didelphis albiventris were investigated immunocytochemically for the occurrence of polypeptide YY (PYY) and enteroglucagon (GLU). PYY- and GLU-immunoreactive cells were observed in the lower part of the ileum, cecum and colon. These cells were seen to emit cytoplasmic basal processes to the neighbouring cells with a number of them reaching the glandular lumen via apical cytoplasmic process. GLU-immunoreactive cells were also present in the oxyntic mucosae and in the pancreatic duct. Staining of consecutive sections for the two polypeptides, respectively, revealed the coexistence of immunoreactivity for PYY and GLU in the same cell type.

Glycosphingolipid patterns of the gastrointestinal tract and feces of germ-free and conventional rats

Acid and non-acid glycosphingolipids of stomach, small and large intestine, and stimulated feces of germ-free and conventional rats of the same stain have been isolated and characterized. The glycosphingolipid patterns of the intestinal organs were chemically and immunologically very similar between the two groups of rats and relatively unaffected by the presence of an intestinal microbial flora. The major exception was the presence of hematoside with N-glycoloylneuraminic acid (NeuGc) (NeuGc alpha 2----3Gal beta 1----4Glc beta 1----1Cer) in the stomach of conventional rats not found in the stomach of germ-free animals. Glycosphingolipids of stimulated feces of germ-free animals were derived from epithelial cells mainly of the small intestine and showed no signs of degradation. Glycosphingolipids of feces of conventional rats completely retained the pattern of blood group A-, B-, and H-active glycolipids as found in sterile feces but contained less of hematoside and more of lactosylceramide. This effect was probably due to degradation by bacteria, as demonstrated in vitro with the production of lactosylceramide after treatment of the isolated acid glycolipids of sterile feces with neuraminidase from Clostridium perfringens. The amount of total non-acid glycosphingolipids per dry weight was similar for stomach, was 50% higher for small intestine, and 300% higher for large intestine of germ-free animals compared to conventional animals. Due to the presence of large amounts of mucins the dry sterile feces contained 12% less non-acid glycolipids than conventional feces. However, calculated per rat per day the germ-free animal excreted more of non-acid glycosphingolipids (1.8 and 1.2 mg, respectively).

Mucosubstance histochemistry of the normal mucosa and carcinoma of the large intestine. Galactose oxidase-Schiff reaction and lectin stainings

Thirty-four cases of carcinoma of the human large intestine were studied employing a battery of histochemical techniques to identify and characterize mucosubstances, including galactose oxidase-Schiff (GOS) reaction and stainings with horseradish peroxidase-labeled lectins. The results disclosed that the goblet cell-type mucin (GCM) of the left colon differed from that of the right colon in containing 8-O-acetylated N-acetylneuraminic acid (NANA) more abundantly and 8-O-acetylated NANA-(alpha Fuc)-beta Gal type terminal structures. The right colonic GCM, on the other hand, was shown to contain alpha Fuc-beta Gal type predominantly. Surface coat-type mucin (SCM) showed consistent histochemical reactivities regardless of the sites in the large intestine. The transitional mucosa surrounding carcinoma tissues characteristically revealed decreased sulfation and neuraminidase-induced GOS reactivity, suggesting the presence of NANA-beta Gal type terminals. The carcinoma tissues resembled the transitional mucosa in showing neuraminidase-induced GOS reactivity, but differed from the latter in possessing intense UEA-I reactivity. The present study indicated that the refined histochemical techniques recently developed were quite useful for understanding the histochemical reactivities correlating with sugar structures.

Bile acids in deermice lacking liver alcohol dehydrogenase

Liver alcohol dehydrogenase (EC 1.1.1.1) is believed to catalyze the oxidation of 26-hydroxylated intermediates in the biosynthesis of bile acids from cholesterol. We have therefore analyzed the composition and size of the bile acid pool in deer-mice genetically lacking alcohol dehydrogenase. Cholic acid was found to be the major primary bile acid accompanied by small amounts of chenodeoxycholic acid. Variable amounts of secondary bile acids were also present, mainly deoxycholic acid and 3 alpha, 12 alpha-dihydroxy-7-oxo-5 beta-cholanoic acid. The same bile acids were found in animals with normal levels of alcohol dehydrogenase. The pool of bile acids in the gallbladder, small intestine and large intestine varied between 4.2 and 8.4 mumol in four animals lacking alcohol dehydrogenase and between 6.0 and 8.4 mumol in four control animals. Ethanol did not influence pool size or composition of bile acids in the animal studied. It is concluded that alcohol dehydrogenase is not obligatory for normal bile acid biosynthesis.

[Hepatoma 27 cells and the epithelium of the large intestine in rats contain the identical set of prekeratin proteins]

It has been shown by means of the immunoblot technique in combination with monoclonal antibodies and peptide mapping that hepatocytes, hepatoma 27 cells, and rat colon enterocytes exhibit a common prekeratin protein with a molecular weight of 49 kD (PK49). This protein and vimentin, a protein contained by intermediate filaments of mesenchymal cells, share at least one antigenic determinant. The generally accepted procedure for prekeratin purification leads to a more or less pronounced degradation of PK49. The degree of degradation is dependent on the type of the tissue extracted. High heterogenicity of prekeratin polypeptides described elsewhere might be due partly to such a degradation process. In addition to PK49, hepatoma 27 cells, absorbing, goblet and proliferating cells of the colon demonstrated three more prekeratin proteins: two major (PK55 and PK40) and one minor (PK53). Monoclonal antibodies not reacting with PK49 do not recognize PK55, PK53 and PK40. PK55, PK49 and PK40 of hepatoma 27 are identical to the appropriate proteins of the colonic epithelium as judged by peptide mapping. Thus, the cells of the hepatocyte origin are able to synthesize the same prekeratins as the colonic epithelium.

Analysis of sialic acids in bovine intestinal mucins

Molecular species of sialic acids released by mild acid hydrolysis from mucins of bovine small and large intestine were characterized by two dimensional thin-layer chromatography and gas chromatography-mass spectrometry. The small and large intestinal mucins contained both N-acetyl- and N-glycolylneuraminic acid. Although O-acetylated derivatives were not detectable in the small intestinal mucin, 9-O-acetyl-N-glycolylneuraminic acid was demonstrated in the large intestinal mucin by thin-layer chromatography and its structure was confirmed by mass spectrometry. Moreover, the presence of three kinds of O-acetyl-N-acetylneuraminic acid and five kinds of O-acetyl-N-glycolylneuraminic acid in the large intestinal mucin was suggested by thin-layer chromatography and mass chromatography. The limited distribution of O-acetylated neuraminic acids suggests that their derivatives are only produced in the mucous glands of the large intestine.

A histochemical study of fibronectin (FN) of the large intestine by the immunoperoxidase technique

Histochemical studies of fibronectin in cancer and adenoma of the large intestine were conducted by the immunoperoxidase technique. The fibronectin immunohistochemical reaction was present in frozen sections, whereas it was obviously suppressed in the formalin-fixed sections. In the normal mucosa of the large intestine, the reaction was strong in the basement membrane of epithelial cells and weaker around the interstitial cells of the lamina propria mucosa. The reaction in cancer tissues was negative in the basal part of the gland, while the interstitial connective tissue was strongly positive for fibronectin. In adenoma, there was a correlation between the intensity of the fibronectin reaction and the degree of epithelial cell atypism; that is, in a gland with severe atypism the reaction was very weak or absent, while in a gland with mild atypism a weak reaction still persisted. It is concluded that this technique will serve as a useful supplementary technique for the purpose of studying the biological role of fibronectin, and that the fibronectin reaction has a close relationship with malignancy and with cellular atypism of the epithelium of the large intestine.

A comparative study of the normal histochemical and proliferative properties of the large intestine in ICR/Ha and C57Bl/Ha mice

The histochemical staining, labeling index and incorporation of [3H] thymidine [TdR] in large intestinal epithelium were compared in four anatomically distinct segments from ICR/Ha and C57Bl/Ha mice. This comparison was done because the incidence of 1,2-dimethylhydrazine (DMH)-induced carcinomas is different for different anatomic segments as well as for the two strains. Within each strain, the amount of [3H] TdR incorporated into mucosal DNA was found to vary less than 20% at each anatomic site of the large intestine. However, there were site-specific differences in the depth of the proliferative populations within the crypts. In autoradiograms from both strains, the crypts of the proximal colon showed maximal [3H] TdR labeling of nuclei in mid-crypt cells, some of which contained mucin. In contrast, the distal colon and rectum were characterized by maximal nuclear labeling in a population of undifferentiated cells near the base of each crypt. In distal ICR/Ha colon, the proportion of labeled nuclei at each crypt depth corresponded to the [3H] TdR labeling of DNA that had been isolated from frozen sections cut sequentially. As visualized with alcian blue-periodic acid Schiff (AB-PAS) and high iron diamine-alcian blue (HID-AB) stains, the epithelial mucin showed site-specific differences, but the differences between the two strains of mice were not remarkable. In contrast to the human and rat large intestine, the acidic mucin in the mouse large intestine was predominantly sialomucin. However in the cecum and mid-distal colon, there was a predominance of sulfomucin. In the various anatomic segments of both strains, the histochemical staining, labeling index and incorporation of [3H]TdR were remarkably similar considering the large differences in susceptibility to chemically-induced neoplastic change.

Demonstration of basic human-brain-specific proteins by the BASO-DALT system

We used the BASODALT system (Cell 12: 1133--1142, 1977) of high-resolution two-dimensional gel electrophoresis to resolve proteins in extracts of human brain and, for comparison, those in nine other human organs. At least 180 protein-staining spots are visible on a BASODALT electrophoretogram of water-soluble human brain proteins. By electrophoresing extracts of different human organs, separately and mixed with brain extract, we could detect 14 basic spots that appear to be present in brain in concentrations at least 20-fold those in any other organ. Measurement of these new basic brain-predominant proteins may provide useful diagnostic information in neurological disorders.

Inhibition of disaccharide digestion in rat intestine by the alpha-glucosidase inhibitor acarbose (BAY g 5421)

Administration of the alpha-glucosidase inhibitor, acarbose (BAY g 5421), to rats together with a sucrose load results in a marked retardation of sucrose digestion. The carbohydrate content of the small intestine is dose dependently increased; the time needed for the absorption is doubled. In the large intestine significant amounts of carbohydrate can be found only after administration of high doses of acarbose (2-4 mg/kg p.o.). In oral sucrose and maltose loading tests the blood glucose increase is dose dependently reduced by acarbose (ED50, 1 or 12 mg/kg, respectively). In perfused jejunal loops of rats, acarbose inhibits the absorption of sucrose (4 g/l) and maltose (1 and 2 g/l), the IC50 values being 3.2, 36, and 57 micrograms/ml, respectively. The data indicate that acarbose effectively inhibits sucrose digestion. It is 10-20 times less effective with maltose as a substrate. Slight malabsorption is induced by acarbose only in doses higher than the ED50.

Purified glial fibrillary acidic protein and desmin are distinct intermediate filament proteins exhibiting similar properties

Glial fibrillary acidic (GFA) protein and desmin were purified from bovine brain and large intestine, respectively, and used in a comparison of the major protein components of two classes of intermediate filaments, the glial and smooth muscle filaments. The proteins are similar in size, charge, and amino acid composition, but clearly distinct. By sodium dodecyl sulfate-gel electrophoresis, GFA protein is about 5,000 daltons smaller than desmin. GFA protein is composed of three isoelectric variants which are all slightly more basic than the two variants observed for desmin. One-dimensional peptide mapping following limited proteolysis under denaturing conditions or following cyanogen bromide cleavage demonstrates that the proteins are not closely related in primary structure. Assembly-disassembly experiments reveal that the proteins share solubility properties and that negatively stained preparations of in vitro polymerized filaments are very similar. Limited proteolysis under native conditions demonstrates substructural similarities; comparative peptide mapping following digestion with chymotrypsin and trypsin suggests related core polypeptides of about 37,000 and 21,000 daltons. We conclude that GFA protein and desmin are distinct with respect to primary structure, but probably represent two of the more closely related classes of intermediate filament proteins.

Glycolipids of rat large intestine. Characterization of a novel blood group B-active tetraglycosylceramide absent from small intestine

A novel blood group B-active tetraglycosylceramide has been isolated from rat large intestine. It is probably present only in the epithelial cells. Although the compound was not obtained pure, the structure was conclusively established by mass spectrometry, proton NMR spectroscopy and degradative studies to be Galp alpha 1 leads to 3Galp(2 comes from 1 alpha Fucp)beta 1 leads to 4Glcp beta 1 leads to 1Cer. The ceramide was composed of mainly trihydroxy long-chain base (18:0) and non-hydroxy fatty acids (16:0-24:0). The glycolipid was absent from small intestine.

Intestinl fragility during ochratoxicosis and aflatoxicosis in broiler chickens

Graded concentrations of dietary ochratoxin (0, 0.5, 1.0, 2.0, 4.0, and 8.0 microgram/g) and aflatoxin (0, 0.625, 1.25, 2.5, 5.0, and 10.0 microgram/g) were fed to broiler chicks from hatching to 3 weeks of age. The breaking strength of the large intestines was decreased significantly (P < 0.05) by ochratoxin (2, 4, and 8 microgram/g), but not by aflatoxin. This fragility was accompanied by an increase in the weight of the large intestine relative to body weight of birds fed ochratoxin (4.0 and 8.0 microgram/g), whereas aflatoxin had no significant (P < 0.05) effect on this parameter. Lipid content of the large intestine was decreased significantly (P < 0.05) by aflatoxin (10.0 microgram/g) and increased by ochratoxin (8.0 microgram/g). Microscopic examination of cross sections of large intestines stained for collagen gave the impression of a great decrease in collagen content of birds fed ochratoxin, but not aflatoxin. The radial length of the collagenous longitudinal folds of the large intestine was decreased significantly (P < 0.05) by ochratoxin (2.0, 4.0, and 8.0 microgram/g). These observations, plus a field case characterized by intestinal ruptures causing carcass condemnations on the processing line and by the occurrence of aflatoxin and ochratoxin in the chicken feed, suggest a novel way in which mycotoxins cause economic loss to agriculture.

Magnesium absorption from leafy vegetables intrinsically labeled with the stable isotope 26Mg

Five leafy vegetables were grown in nutrient solutions in which the natural magnesium was replaced by the stable isotope, 26Mg. They were fed to rats in a test meal together with the extrinsic tracer 28Mg: a) to determine to what extent the instrinsic tracer (26Mg) was exchangeable with extrinsic 28Mg during the digestion and absorption processes, and b) measure the relative Mg availability from the different vegetables. The two tracers, 26Mg and 28Mg, were close to 100% exchangeable, as judged by the ratio of 26Mg/28Mg in the livers. Mean relative Mg absorption from the various vegetables ranged from 108 to 118% of the Mg absorbed from a standard test meal containing MgSO4. There were no statistically significant differences between the rates of Mg absorption from the five vegetables although two of the vegetables tested contained oxalate. The usefulness of stable 26Mg as a tracer in Mg bioavailability tests is discussed.

[Effect of dysentery endotoxin on the histamine and serotonin concentration in the mucosa of the small intestine]

An increase in histamine content and a decrease in serotonin concentration occurred in mucosa of mouse large intestine in dynamics of dysenteric intoxication. The content of serotonin was more dependent on the endotoxin dose and duration of its action of these biogenic amines in normal state was altered under the pathological conditions. The impairments in metabolism of biogenic amines in response to dysenteric intoxication were reduced after administration of tryptophane and pyridoxine suggesting the reversibility of these impairments.

Distribution and metabolism of ingested NO3- and NO2- in germfree and conventional-flora rats

Germfree and conventional-flora Sprague-Dawley rats were fed sodium nitrate or sodium nitrite in their drinking water (1,000 microgram/ml), and various organs, tissues, and sections of the intestinal tract were assayed for nitrate (NO3-) and nitrite (NO2-) by a spectrophotometric method. When fed NO3-, germfree rats had chemically detectable levels of NO3- (only) in the stomach, small intestine, cecum, and colon. Conventional-flora rats fed NO3- had both NO3- and NO2- in the stomach, but only NO3- in the small intestine and colon. When fed NO2-, germfree rats had both NO3- and NO2- in the entire gastrointestinal tract. Conventional-flora rats fed NO2- had both ions in the stomach and small intestine, but only NO3- in the large intestine. Conventional-flora rats fed NO3- or NO2- had lower amounts of these ions in the gastrointestinal tract than comparably fed germfree rats. Control (non-NO3- or NO2--fed) germfree and conventional-flora rats had trace amounts of NO3- (only) in their stomachs and bladders. These results, in conjunction with various in vitro studies with intestinal contents, suggest that NO3- or NO2- reduction is a function of the normal bacterial flora, whereas NO2- oxidation is attributable to the mammalian host. In addition, the distribution of these ions after their ingestion appears more widespread in the body than previously thought.

Cyclic adenosine 3', 5' monophosphate: a possible indicator of premalignant changes in the large bowel

Cyclic adenosine 3', 5' monophosphate (cyclic-AMP) has been estimated in mucosal biopsy samples removed from the descending colon and rectum at endoscopy to investigate the possibility of using this substance for monitoring pre-malignant changes in the large bowel. Four groups of patients have been studied: those with normal large bowel and rectal mucosa; those with non-malignant inflammatory bowel disease; those with an adenomatous polyp in the descending colon or sigmoid colon; and those with a rectal adenocarcinoma. No difference was found in the cyclic-AMP content of 'normal' rectal mucosa, 'normal' colonic mucosa, 'diseased' colonic mucosa, carcinomas, and uninvolved mucosa adjacent to the polyps. Less cyclic-AMP was found in the polyps than in adjacent uninvolved mucosa. Conversely, more cyclic-AMP was found in the carcinomas than in adjacent uninvolved mucosa. It is concluded that although cyclic-AMP may be a very useful parameter for delineating the extent of the disease in individual patients, it is not a suitable biochemical marker for the screening of neoplastic changes in the large bowel in the population as a whole.

Prenatal intestinal histology and histochemistry in the goat

The mucosa of the small and large intestine of goat fetuses exhibited villi which had disappeared after the 32.5-cm curved crown rump (CVR) stage. At places, the stratified epithelial lining persisted among the normal columnar epithelium with goblet cells. The concentration of goblet cells increased with age, while the thickness of the epithelium decreased. The crypts of Lieberkühn were tortuous at the base. Brunner's glands appeared at the 14.2-cm CVR stage. Peyer's patches appeared at the 24.5-cm CVR stage in the ileum. The muscularis mucosae differentiated in the large intestine in group II (16.2- to 24.5-cm CVR length) and progressed caudocranially. The striated border of the intestinal epithelium presented with alkaline phosphatase activity; this border and the goblet cells also stained for mucin. Glycogen was demonstrable in the epithelium with greater concentrations in the duodenum and jejunum in group I (11.5- to 14.6-cm CVR length), and in the ileum and large intestine in group III (30.8- to 39.5-cm CVR length).

A new histochemical technique of use in the interpretation and diagnosis of adenocarcinoma and villous lesions in the large intestine

The periodic acid-thionin Schiff/potassium hydroxide/periodic acid-Schiff (PAT/KOH/PAS) procedure has been used to investigate the histochemical staining characteristics of the mucins found in adenocarcinoma and villous lesions of the large intestine. The 46 blocks examined represented 58 lesions from 37 patients, all of whom had had resections for carcinoma of the colon. tin sharp contrast to normal colon, none of the adenocarcinomas stained red with the PAT/KOH/PAS. With two exceptions the poorly and moderately differentiated adenocarcinomas stained blue, whereas of the well differentiated lesions half were blue and half purple. The malignant villous lesions demonstrated the same trends, although a larger percentage were purple. None of the benign lesions stained blue. It is suggested that malignancy in the colon is accompanied by an increase in blue staining in the PAT/KOH/PAS technique and that such staining may be of value in the interpretation of highly atypical adenoma where it might identify the onset of malignancy. This change in staining indicates a distinct alteration in the chemistry of the mucins which we interpret as a reduction in the degree of side chain O-acylation of their constituent sialic acids.

Fatty acids and long-chain bases of gangliosides of human gastrointestinal mucosa

The fatty acid and long-chain base composition of five major gangliosides from human stomach and small and large intestine mucosa were analyzed with gas chromatography. All the gangliosides greatly resembled each other in the fatty acid pattern. The main fatty acids were C16:0, C18:0, C22:0 and C24:1. No hydroxy fatty acids could be detected. In all the gangliosides 4-sphingenine was the predominant long-chain base (70-75%). About 15% of the long-chain bases had 20 carbon atoms in their chain. No trihydroxy long-chain bases could be detected.

Fermentative digestion of food in the colobus monkey, Colobus, polykomos

Fermentation of leafy food occurs in the enlarged saccus gastricus of the colobus monkey with the formation of volatile fatty acid, as in the rumen of ruminant animals. About half of the digestible organic matter and cellulose of the diet is digested in this way.

[Determination of carcinoembryonic antigen (CEA) in patients with tumors of the large intestine. Experience with a new radioimmunoassay (author's transl)]

Specimens from 93 patients with histologically confirmed tumors of the large bowel (53 single, 40 sequential determinations) were investigated by a new CEA radioimmunoassay (double antibody method, direct serum determination). Of the single and preoperative sequential determinations 37-40% were normal (below 2.5 ng/ml), one third was intermediately elevated (2.6-15 ng/ml) and 26-28% were highly pathological leveled (over 15 ng/ml). Following operation, cases with local or regionally confined tumor showed significantly more normal or normalizing CEA levels within 1-6 weeks (17/27), whereas patients with overt metastases developed more pathological or increasingly pathological levels (8/11).

Gangliosides of the human gastrointestinal mucosa

Gangliosides of the human alimentary mucosa were purified and analysed with thin-layer chromatography and gas chromatography. The content of ganglioside neuraminic acid was 0.16 mumol/g dry weight in the stomach, 0.07 mumol/g dry weight in the small intestine and 0.11 mumol/g dry weight in the large intestine. Mono- and disialosylhemosides were the major gangliosides, on a molar basis 68% of the total found in the stomach and 44% of the total in the small and large intestine. Considerable amounts of more complex gangliosides were found, especially in the small and large intestine, in which the molar content of tri- and tetraglycosylgangliosides containing galactosamine made up 38% of the total. Two glucosamine-containing gangliosides were also found, the probable structures of which were mono- and disialotetraglycosylceramide. The presence of the latter is reported for the first time.

A histochemical method of differentiating lower gastrointestinal tract mucin from other mucins in primary or metastatic tumours

Epithelial mucins of the normal terminal ileum, caecum, colon, and rectum of man are unique in that they alone exhibit staining following the periodate-borohydride/KOH/PAS technique. Application of this technique enables one to differentiate those mucin-producting metastases arising from adenocarcinoma of the lower gastrointestinal tract from those arising elsewhere, and may occasionally be useful in determining the site of the primary tumour when it is in doubt. Furthermore, it was found to be especially useful in distinguishing between primary adenocarcinoma of the lung and metastases in the lung from adenocarcinoma of the lower gastrointestinal tract.

Characteristics of mesenteric lymph node cells homing to gut-associated lymphoid tissue in syngeneic mice

A subpopulation of cells in murine mesenteric lymph nodes, about 15% of those synthesizing DNA at any given time, homes specifically to the gut and mesenteric nodes of syngeneic recipients within 1 day of i.v. transfer. In contrast, cells from Oeyer's patches or peripheral lymph nodes do not. A large proportion of the B blasts which home to the small intestine has surface Ig, but lacks complement receptors. Thy-1-positive T blasts home to the gut to a lesser extent than B blasts. However, it is probable that equal fractions of B and T blasts home to mesenteric nodes. Homing is not affected by measures calculated to interfere with the combination of cell surface IgA and secretory component.

Distribution and metabolism of 3H-2,5,2',5'-tetrachlorobiphenyl in rats

Distribution and metabolism of an isomeric polychlorinated biphenyl were determined in rats. Over 70% of a single dose of 3H-2,5,2',5'-tetrachlorobiphenyl was excreted in the feces and another 13% in the urine during a 14-day period. Adipose tissue, blood, skin, and liver were found to contain low levels of the compound. Over 90% of the excreted tritiated compound was found to be metabolized, the major metabolite being identified as 3-OH-2,5,2',5'-tetrachlorobiphenyl. All of the unmetabolized 2,5,2',5'-tetrachlorobiphenyl was eliminated by the alimentary route.

The histochemical interpretation of the complex results of methylation upon gastrointestinal tract mucins, with special reference to the periodic acid-Schiff reactivity

The histochemical use of methylation has complex results; particularly in respect of the periodic acid-Schiff reaction, these are analyzed and discussed. Methods are described which allow the separate study of the following effects: (a) the removal of the KOH/periodic acid-Schiff effect; (b) removal of sialic acid from a potential vicinal diol; and (c) the removal of O-sulfate ester from a potential vicinal diol. The use of the Smith degradation technique, in addition to the above, also allows inferences to be drawn in respect of the structure of the mucins (glycoproteins) being investigated.

The histochemical demonstration of O-acylated sialic acid in gastrointestinal mucins. Their association with the potassium hydroxide-periodic acid-schiff effect

O-Acylated sialic acids have been demonstrated histochemically in the epithelial mucins of the lower end of the gastrointestinal tract. The potassium hydroxide-periodic acid-Schiff effect has been shown to be due, in most areas, to the presence of these O-acyl esters on the polyhydroxy side chains of sialic acid. The esters have been shown to hinder the removal of the sialic acids by either neuraminidase or acid hydrolysis unless tissues were pretreated with alcoholic potassium hydroxide. It is suggested that substitution at the C4 position is responsible for their neuraminidase resistance.