Glycoconjugates of the cecal intestinal epithelium of the chick before and after hatching: histochemical study performed with peroxidase-conjugated lectins]

A battery of seven different horseradish peroxidase-labelled lectins (PNA, ConA, DBA, SBA, LTA, WGA and UEA I) was used to study the distribution and changes of carbohydrate moieties of glycoconjugates in the caecal epithelium (proximal and distal tracts) of the chick embryo and of the 3 days old chicken. The chief results showed that: 1. The appearance of some sugar residues was earlier observed at the epithelium of the distal tract than the proximal one (Tab. 2). 2. The presence of sialic acid was detected only after hatching (Fig. 4, Tab. 2). 3. During the embryonic caecal development enterocytes and goblet cells were characterized by the presence of the same sugar residues (Tab. 2). 4. By a quantitative point of view, differences in sugar residues content between the epithelium of the proximal and distal tract were observed. The epithelial cells of the distal tract were generally characterized by an higher content of saccharide moieties (Tab. 2). 5. At the end of the incubation period and after hatching enterocytes and goblet cells showed differences in content of some sugar residues (Fig. 1-3, Fig. 5-8, Tab. 2).     

Pathological effects of Echinostoma caproni (Trematoda) in the domestic chick

Domestic chicks experimentally infected with Echinostoma caproni for 2 weeks showed a dilated ileum, unkempt feathers, watery diarrhoea, and weight loss. The ileum from infected and control chicks was fixed in 10% neutral buffered formalin, and prepared as 10 microns paraffin sections stained in haematoxylin and eosin, Papanicolau, periodic acid-Schiff, picro-ponceau, and alcian blue. The infected ileum showed atrophic villi, hypertrophied circular musculature with collagen-like fibres and haemorrhagic zones. The brush borders of epithelial cells and goblet cells were absent in the mucosa of the infected ileum. Worms in contact with host mucosa showed tissue plugs in the suckers. The cephalic spines of worms abraded the host mucosa.     

Susceptibility of 1- and 3-Day-Old Chicks to Infection with the Coccidium, Eimeria acervulina

SYNOPSIS. One-day-old chicks were less susceptible to experimental infection with E. acervidina than were 3-day-old chicks. Chicks fed intact oocysts when 3 days old produced 5.3, 6.7, and 42.7 times as many oocysts and had more extensive lesions than did those fed a similar number of oocysts when 1 day old. When oocyst suspensions that contained both liberated sporocysts and intact oocysts were administered, chicks infected when 3 days old produced only 1.8, 1.3, and 2.6 times as many oocysts as did those infected when 1 day old.
Examination of gizzard and intestinal contents of chicks killed 2–1½ hr after receiving massive numbers of intact oocysts showed that only a few sporocysts were liberated from oocysts in the gizzard of 1-day-old chicks, whereas more were liberated in the gizzard of 3-day-old chicks. Very few sporozoites were found in the duodenum of the 1-day-old chicks. but there was a linear increase in the percentages in samples from lower levels of the small intestine. In 3-day-old chicks, excystation in the duodenum was high and, instead of increasing, remained at about the same level in the jejunum.
The far smaller number of liberated sporocysts in the gizzards of 1-day-old chicks is attributed to less musculature and an incompletely developed grinding surface The delayed excystation of sporozoites in the intestine of 1-day-old chicks is thought to be due to suboptimal concentrations of trypsin and/or other pancreatic enzymes effecting excystation.
The lighter infections observed in 1-day-old chicks, as compared to those in chicks 3 days old, are attributed to (a) a smaller number of liberated sporocysts leaving the gizzard, (b) delayed excystation in the intestine, and (c) less opportunity for sporozoites to penetrate epithelial cells.     

Lectin binding in the ovary of the chick embryo and newborn.

The content, distribution and changes of the glycoconjugates sugar residues in the ovaries of chick embryos, from the 8th day of incubation to hatching and in 1-day old chick, were investigated. For this purpose, a battery of seven HRP-conjugated lectins was used (DBA, SBA, PNA, ConA, WGA, LTA and UEA I). Our data showed that SBA was a marker of the most immature oogonia in the ovarian cortex and medulla. The reactivity with ConA appeared to characterize the cells immediately prior to as well as during the meiotic division, as demonstrated by the presence of alpha-D-mannose at the "Balbiani bodies" in the oogonia of the ovarian cortex. The detection of Con A and SBA reactivity corresponded to maturative stages of the early oogonia in different cortical zones of the chick ovary. Our data also revealed that PNA seemed to be a marker of the degenerating oogonia located in the ovarian medulla. Moreover, PNA binding was a characteristic finding in the endothelial cells of the vessels located in the compact portion of the medulla in the left ovary, from the 8th to the 21st day of incubation and after hatching; PNA reactivity was only seen from the 16th day onwards in the endothelial cells of the cortex. During the whole considered period of incubation and after hatching, reactivity with UEAI, LTA and DBA was never detected.     

Intestinal endocrine cells of chicks around the time of hatching

Summary The duodenum of 16-day Black Australorp chick embryos, and the duodenum, ileum, large intestine and caeca of 18-day embryos and of chicks within 30 h of hatching, have been studied by electron microscopy. Cells were found with secretory granules resembling those in mammalian EC, S, A-like, EG and D cells (terminology of Solcia et al., 1973), and were on this basis tentatively identified accordingly. The distribution and frequency of the chick cells in different parts of the tract correspond well to the situation in mammals.Supported by grants from the Senate Research Committee of the University of the Witwatersrand, JohannesburgThe author gratefully acknowledges the help of Professors E. Solcia and N. Ferreira     

Lectin histochemistry of mucus-secreting cells in the calf bulbourethral gland.

The bulbourethral glands of 2-month-old calves were studied by means of lectin histochemical methods. The lectin-binding sites for each considered lectin can be divided into three groups according to their zonal topography. In the first group including PNA, MPA, RCAI, SBA and BPA binding sites were seen in most of the secreting tubules and end pieces. In the second group (WGA, GSI, DBA, UEAI and Con A) the reactive cells were limited to a reduced number of tubuloalveolar units generally located at the periphery of the gland. The third group was composed of two lectins, GSII and LTA for which the bulbourethral parenchyma was unreactive. These findings can be related to the glandular activity of the calf bulbourethral gland except for restricted peripheral areas with an appearing functional differentiation. This duality in the histochemical nature of glycoconjugates was compared with previous results obtained in other groups of mammals.     

Trichinella spiralis: enteric mucin-related response to experimental infection in conventional and SPF pigs

Duodenal and jejunal responses to infection with Trichinella spiralis were compared in weaned piglets with a "normal dirty" vs. a "clean SPF" gut flora. Histochemical staining of neutral, acidic, sialylated, and sulphated residues was used to assess biosynthetic responses in mucin-secreting goblet cells. Peanut and Ulex lectins were also used to assess responses within the intestinal glycocalyx. Histomorphometric analysis was undertaken to evaluate the distribution and staining patterns of goblet cells in villi and crypts. Our analysis showed that stored mucin within goblet cells increased more in the infected conventional animals than in the infected SPF group. This was accompanied by changes in the pattern of sulphation and sialylation in the duodenum and jejunum. The thickness of the glycocalyx was increased in both duodenum and jejunum in both infected groups. However, this effect was greater for the infected SPF animals than the infected conventional animals. No significant differences were observed between uninfected conventional and uninfected SPF pigs.     

Progesterone receptor is constitutively expressed in chicken intestinal mesothelium and smooth muscle

We have previously shown that progesterone receptor (PR) is expressed in the mesothelium of the chick oviduct and ovary and in the smooth muscle cells of the oviduct and the bursa of Fabricius. Here, we investigated the presence of PR in different parts of the peritoneum and abdominal organs using an immunohistochemical staining based on monoclonal antibodies against chicken PR. In 4-week-old sexually immature chicks, PR expression was located in the mesothelial cells of different parts of the peritoneum, in a thin layer of muscle cells of the ileum and throughout the muscle tissue of the colon and cloaca. In chicks of the same age treated with estrogen, PR was demonstrated similarly in the peritoneum and in the smooth muscle cells of the ileum, colon and cloaca. Using 25-week-old mature chickens, PR was also detected in identical tissues. Immunoblotting of the cloacal cytosol revealed the B form, but no A form of PR, both of which were found in the oviduct samples. Muscle cells of the duodenum and jejunum were not found to contain PR. Estrogen treatment was not needed to stimulate the production of PR in any of the tissues examined. We therefore conclude that the B form of PR is constitutively expressed in the mesothelial cells in different parts of the peritoneum and also in the smooth muscle cells of the ileum, colon and cloaca.     

THE GUT FLORA OF THE CHICK. II. THE ESTABLISHMENT OF THE FLORA

SUMMARY: Viable counts were made in three media of material from the crop, gizzard, duodenum, ileum and caeca of chicks. Groups of birds 2, 4, 7, 10, 13, 16 and 30 days old were studied. The results showed that a balanced gut flora is established one day after feeding. An indication of the actual development of the flora was obtained in chicks 4 hr after feeding. The relationship between the flora at different ages and that in newly-hatched chicks before feeding is discussed.     

Lectin binding in the human foetal testis

In the present study we have investigated the oligosaccharidic content of the glycoconjugates within the human foetal testis starting from its earliest differentiation phase (8, 10 and 12 weeks of gestation). To this purpose we have used a battery of six horseradish peroxidase-labelled lectins (SBA, PNA, WGA, UEAI, LTA and ConA). We have obtained a complete distributional map of the sugar residues of the glycoconjugates in the coelomic mesothelium, tunica albuginea, pre-Sertoli cells, pre-gonocytes, Leydig cells, basement membrane of the sex cords, interstitial tissue, mastocytes and endothelial cells of the capillary vessels. Since the beginning of the testis differentiation phase the cells of the coelomic mesothelium showed a large amount of sugar residues. In the pre-Sertoli cells and in the pre-gonocytes a role played as structural molecules by some oligosaccharides could be hypothesized. D-galactose-(beta1-->3)-N-acetyl-D-galactosamine, sialic acid, N-acetyl-D-glucosamine and alpha-D-mannose could be involved in inducing and maintaining the cellular activity of the Leydig cells.     

Bacteria isolated from the duodenum, ileum, and cecum of young chicks.

Facultatively anaerobic and strictly anaerobic bacteria colonizing the intestinal tracts of 14-day-old chicks fed a corn-based diet were enumerated, isolated, and identified. Colony counts from anaerobic roll tubes (rumen fluid medium) or aerobic plates (brain heart infusion agar) recovered from homogenates of the duodenum, upper and lower ileum, and cecum varied appreciably among samples from individual birds. Anaerobic and aerobic counts from the duodenum and ileum were similar. Anaerobic counts were highest from the cecum (0.7 X 10(11) to 1.6 X 10(11)/g of dry tissue) and exceeded aerobic plate counts by a factor of at least 10(2). Facultatively anaerobic groups (Streptococcus, Staphylococcus, Lactobacillus, and Escherichia coli) comprised the predominant flora of the duodenum and ileum, although large numbers of anaerobes (9 to 39% of the small intestine isolates), represented by species of Eubacterium, Propionibacterium, Clostridium, Gemmiger, and Fusobacterium, were also recovered. Strict anaerobes (anaerobic gram-positive cocci, Eubacterium, Clostridium Gemmiger, Fusobacterium, and Bacteriodes) made up nearly the entire microbial population of the cecum. Scanning electron microscopy of the intestinal epithelia of chicks revealed populations of microbes on the duodenal, ileal, and cecal mucosal surfaces.     

Histochemical features of the Muscovy duck small intestine during development

We demonstrated for the first time the distribution and morphology of argyrophil and of goblet cells in the mucosa of the small intestine of the Muscovy duck during development using the Grimelius silver staining and alcian blue/periodic acid-Schiff (AB/PAS) staining technique. The argyrophil cells distribution was variable over the length of the small intestine from embryonic day 24 (24E) to post-hatching day 13 (13d). In the villi most argyrophil cells belonged to the open-type, while in the crypts they belonged to the closed-type. In the duodenum the density of argyrophil cells was highest at hatching, while in the jejunum and in the ileum the highest density value was at hatching and 13d. AB/PAS-positive goblet cells appeared on the villi and crypts of the duodenum and jejunum at 30E, and in the ileum at hatching. The density of AB/PAS-positive cells was the highest in the three segments at hatching. The AB-positive cells, compared with the PAS-positive cells, predominated in villi and crypts of the three segments, moreover the rate of AB-positive cells to PAS-positive cells significantly decreased from 30E to 9d. An increase in argyrophil and goblet cells number during the later incubation and at hatching, could indicate the small intestine in that period is being prepared to face a new diet.     

Oocyte and zygote zona pellucida lectin binding in BALB/cBy and C57BL/6By mice and their F1 hybrids

Zona pellucida intact oocytes and zygotes from two inbred strains of mice (BALB/cByEss and C57BL/6ByEss) and their F1 hybrids were reacted with a lectin panel (ConA, WGA, sWGA, PNA, UEA I, LTA, BSB4, DBA, PHA-P, LPA, and LFA). No major differences were observed between groups of mice for the majority of the lectin binding patterns. However, oocytes from BALB/cByEss and the F1 (C57BL/6ByxBALB/cBy) gave identical binding patterns for PNA. Following fertilization BALB/cByEss and the F1 (C57BL/6ByxBALB/cBy) bound UEAI and LTA more strongly, but the other two groups of mice demonstrated identical weaker binding of UEAI and LTA. These results indicate the possible influence of the paternal genotype on zona pellucida formation.     

Developmentally regulated lectins from chick muscle, brain, and liver have similar chemical and immunological properties

Developmentally regulated lectins in extracts from brain, liver and muscle of 16-day-old chick embryos and liver of 7-day-old chicks have been purified by affinity chromatography. The purified preparations from the different tissues were indistinguishable in molecular weight and isoelectric point. The lectins could also not be distinguished when tested as antigens with antiserum raised against highly purified muscle lectin. This apparent identity was indicated both in double gel diffusion tests and by determination of the antibody-mediated inhibition of hemagglutination activity of the various lectins. Thiodigalactoside and lactose were potent inhibitors of the lectins from all sources. Galactose was a less potent inhibitor, especially with preparations from embryonic liver. After isoelectric focusing of these purified preparations, they all showed reduced and equivalent galactose sensitivity. Since the lectins from the different tissues appear identical, there is presently no basis to infer that they impart qualitative uniqueness to these tissues during differentiation.     

泽陆蛙消化道组织学观察

采用解剖学和组织学的方法对泽陆蛙消化道各部分的形态和组织学结构进行了观察。泽陆蛙的消化道分为口腔、咽、食道、胃、十二指肠、回肠和大肠。各管壁都由黏膜层、黏膜下层、肌层和外膜组成。食道黏膜层有皱褶和纤毛,无杯状细胞;胃黏膜层有杯状细胞和胃腺,黏膜下层有血管分布;小肠具绒毛、杯状细胞和肠腺,大肠皱褶少,杯状细胞也少。     

Regional differences in the appearance of adult-type glycosphingolipids in the small intestine of inbred rats at weaning time

The small intestine of 15- to 33-day-old rats was cut into four segments: duodenum, proximal jejunum, distal jejunum, and ileum. Neutral glycosphingolipids and gangliosides were purified from each segment and analyzed by thin-layer chromatography in order to study the developmental appearance of adult-type glycolipids at each level of the small intestine. Type 1 A-6 glycolipid was first detected in the ileum at 15 days and subsequently in the jejunum and duodenum at 19 days of age. N-Glycolylneuraminic acid was expressed first in the ileum at 17 days, then in the proximal jejunum at 21 days, but only after 29 days in the duodenum. In each region, 6-8 days were required between first detection and full expression of N-glycolylneuraminic acid. The presence of 2-hydroxylated fatty acids in glucosylceramide was found first in the ileum at 19 days, 2-3 days before appearing in the duodenum and proximal jejunum. A period of 2-3 days was necessary to reach full adult-type level of 2-hydroxylated fatty acids in glucosylceramide. These results show that adult-type glycolipids appear earlier in the distal than in the proximal region of the rat small intestine, and that different glycolipids appear at different times and at different rates. The finding that the biochemical differentiation of the whole small intestine expands over a period of 3 days to 2 weeks, depending on the region and the glycolipid, before being fully completed indicates that, in addition to the time lag observed between the distal and the proximal region, the new cells arising from the crypt of Lieberkhün after 15 days of age are not at once fully differentiated.     

Histochemical characteristics of mucins in the small intestine. A comparative study of normal mucosa, benign epithelial tumours and carcinoma

Synopsis The histochemical properties of the mucins in seven benign epithelial tumours and 15 carcinomas distributed along the duodenum, jejunum and ileum were investigated and compared with normal controls. This study reveals that (a) goblet cells in normal small intestine contain neutral and sialomucins but no sulphated material; (b) the proportion of the different types of mucins in the goblet cells vary along the crypts and villi with an increasing amount of sialomucins towards the villus top; (c) mucin composition also changes from duodenum to ileum particularly in the proportions of sialic acid types and in the presence of traces of sulphomucins in the ileal mucosa close to the ileo-caecal valve, suggesting a gradual transition through the small intestine to the colon; (d) benign tumours show the same mucin pattern as normal mucosa; (e) the mucosa adjacent to carcinoma shows increasing amounts of sialomucins and sulphomucins; (f) carcinomas present a variety of mucin patterns, and thus the study of mucins seems to be of no value in differentiating tumours of the small intestine from those elsewhere in the gastrointestinal tract. A working hypothesis based on the Unitary Theory of the origin of the intestinal epithelial cells is proposed to explain the variations in glycoprotein synthesis with cell differentiation and carcinogenesis.     

Fluorochrome-coupled lectins reveal distinct cellular domains in human epidermis

The distribution of saccharide moieties in human interfollicular epidermis was studied with fluorochrome-coupled lectins. In frozen sections Concanavalin A (Con A), Lens culinaris agglutinin (LCA), Ricinus communis agglutinin I (RCAI), and wheat germ agglutinin (WGA) stained intensively both dermis and viable epidermal cell layers, whereas peanut agglutinin (PNA) bound only to living epidermal cell layers. Ulex europaeus agglutinin I (UEAI) bound to dermal endothelial cells and upper cell layers of the epidermis but left the basal cell layer unstained. Dolichos biflorus agglutinin (DBA) bound only to basal epidermal cells, whereas both soybean agglutinin (SBA) and Helix pomatia agglutinin (HPA) showed strong binding to the spinous and granular cell layers. On routinely processed paraffin sections, a distinctly different staining pattern was seen with many lectins, and to reveal the binding of some lectins a pretreatment with protease was required. All keratin-positive cells in human epidermal cell suspensions, obtained with the suction blister method, bound PNA, whereas only a fraction of the keratinocytes bound either DBA or UEAI. Such a difference in lectin binding pattern was also seen in epidermal cell cultures both immediately after attachment and in organized cell colonies. This suggests that in addition to basal cells, more differentiated epidermal cells from the spinous cell layer are also able to adhere and spread in culture conditions. Gel electrophoretic analysis of the lectin-binding glycoproteins in detergent extracts of metabolically labeled primary keratinocyte cultures revealed that the lectins recognized both distinct and shared glycoproteins. A much different lectin binding pattern was seen in embryonic human skin: fetal epidermis did not show any binding of DBA, whereas UEAI showed diffuse binding to all cell layers but gave a bright staining of dermal endothelial cells. This was in contrast to staining results obtained with a monoclonal cytokeratin antibody, which showed the presence of a distinct basal cell layer in fetal epidermis also. The results indicate that expression of saccharide moieties in human epidermal keratinocytes is related to the stage of cellular differentiation, different cell layers expressing different terminal saccharide moieties. The results also suggest that the emergence of a mature cell surface glycoconjugate pattern in human epidermis is preceded by the acquisition of cell layer-specific, differential keratin expression.     

Distribution,pharmacological characterization and function of the 18 kDa translocator protein in rat small intestine

Background information. The TSPO (18 kDa translocator protein) is a mitochondrial transmembrane protein involved in cholesterol transport in organs that synthesize steroids and bile salts. Different natural and synthetic high‐affinity TSPO ligands have been characterized through their ability to stimulate cholesterol transport, but also to stimulate other physiological functions including cell proliferation, apoptosis and calcium‐dependent transepithelial ion secretion. Here, we investigate the localization and functions of TSPO in the small intestine. Results. TSPO was present in enterocyte mitochondria but not in rat intestinal goblet cells. Enterocyte cytoplasm also contained the endogenous TSPO ligand, polypeptide DBI (diazepam‐binding inhibitor). Whereas intestinal TSPO had high affinity for the synthetic ligand PK 11195, the pharmacological profile of TSPO in the duodenum was distinct from the jejunum and ileum. Specifically, benzodiazepine Ro5‐4864 and protoporphyrin IX showed 5–13‐fold lower affinity for duodenal TSPO. The mRNA and protein ratios of TSPO to other mitochondrial membrane proteins VDAC (voltage‐dependent anion channel) and ANT (adenine nucleotide transporter) were significantly different. PK 11195 stimulated calcium‐dependent chloride secretion in the duodenum and calcium‐dependent chloride absorption in the ileum, but did not affect jejunum ion transport. Conclusions. The functional differences in subpopulations of TSPO in different regions of the intestine could be related to structural organization of mitochondrial protein complexes that mediate the ability of TSPO to modulate either chloride secretion or absorption in the duodenum and ileum respectively.