Distal Part Of Colon Research Articles

Transplantation of intestinal organoids into a mouse model of colitis.

Intestinal organoids are fundamental in vitro tools that have enabled new research opportunities in intestinal stem cell research. Organoids can also be transplanted in vivo, which enables them to probe stem cell potential and be used for disease modeling and as a preclinical tool in regenerative medicine. Here we describe in detail how to orthotopically transplant epithelial organoids into the colon of recipient mice. In this assay, epithelial injury is initiated at the distal part of colon by the administration of dextran sulfate sodium, and organoids are infused into the luminal space via the anus. The infused organoids subsequently attach to the injured region and rebuild a donor-derived epithelium. The steps for cell infusion can be completed in 10 min. The assay has been applied successfully to organoids derived from both wild-type and genetically altered epithelial cells from adult colonic and small intestinal epithelium, as well as fetal small intestine. This is a versatile protocol, providing the technical basis for transplantation following alternative colonic injury models. It has been used previously for functional assays to probe cellular potential, and formed the basis for the first in-human clinical trial using colonic organoid transplantation therapy for intractable cases of ulcerative colitis.

КІЛЬКІСНИЙ ТА ЯКІСНИЙ СКЛАД МІКРОБІОТИ ДИСТАЛЬНОГО ВІДДІЛУ ТОВСТОЇ КИШКИ ЩУРІВ У РІЗНІ ТЕРМІНИ ЕКСПЕРИМЕНТАЛЬНОГО 6-OHDA-ВИКЛИКАНОГО ПАРКІНСОНІЗМУ (ПІЛОТНІ ДОСЛІДЖЕННЯ)

n the aspect of the existence of the gut brain axis are considered quantitative changes of the distal part of colon's microbiota (Mb) under conditions of experimental parkinsonism. Studies were done on laboratory non-linear male rats (140–160 g, n = 7). Parkinsonism was modeled by onesided destruction of the dopaminergic neurons of a compact part of the substantia nigra of brain, causing by stereotaxic microinjections 12 mg neurotoxin 6-OHDA (Sigma-Aldrich, Germany) in the left lateral ascending bundle. Changes in the quantitative Mb composition were determined bacteriologically by sowing 10-fold dilutions of fecal biopsy on differential diagnostic media (HiMedia, India) in 1, 1.5, 2 months after induced parkinsonism. Research has been shown that within the fecal Mb of rats, within 2 months from the beginning of the experiment, significant changes were detected only for E.coli. The amount of lac(+) E.coli increased from 1,5 months to 2 folds (from lg 4,65 ± 0,80 CFU/g to lg 6,08 ± 0,70 CFU/g (1,5 months), after 2 months – from lg 4.39±0.55 CFU/g to lg 6.24±1.26 CFU/g. At the same time, the amount of E.coli lac(-) decreased by 2-3 folds. The number of the genus Bifidobacterium and Lactobacillus remained within the control values. After 2 months after induced parkinsonism, there was a tendency to increase the number of Clostridium species. These results suggest minor microbiota changes of 6-OHDA-induced parkinsonism in rats. These results are preliminary and require more detailed study.

Mango (Mangifera indica cv. Azucar) antiinflammatory and chemopreventive role during colorectal carcinogenesis

Chemopreventive activities of natural compounds result in the modulation of several pathways and molecular targets. It is common to find effective potential candidates for cancer chemoprevention with anti-inflammatory properties. Mango (Mangifera indica cv. Azucar) has shown anticarcinogenic effects and it is a source of bioactive compounds. This study evaluated the effects of mango on Aberrant Crypt Foci formation and inflammatory biomarkers after initiation of colon carcinogenesis in AOM-treated mice. Ripped mango pulp (Mangifera indica cv. Azucar) composition was identified by HPLC. Azoxymethane-treated mice received the fruit (0.3% w/v) for eight weeks and the distal part of colon was collected and stained with methylene blue to look for aberrant crypt foci (ACF); scrapped mucosal cells were processed for prostaglandin E2 detection by ELISA; and blood levels of pro-inflammatory cytokines ( interleukin 1-Beta, tumor necrosis factor-alpha, interleukin 6) were also assessed by ELISA. Student’s t.test was used for the comparisons between mango treated and untreated groups. ACF formation was reduced by 67.5% and prostaglandin E2 levels were also reduced in mice which ingested the fruit. Cytokines levels were unchanged by mango consumption. In the chromatography were identified phenolic acids and Beta-carotene. Mango pulp showed chemopreventive effects through the reduction of ACF formation, by means of blocking hyperproliferation which is correlated with decreasing levels of PGE2.

Distribution and Characterisation of Goblet Cells in the Large Intestine of Ostriches during the Pre- and Post-Hatch Period.

The role of goblet cell secretion, containing mucopolysaccharides, in the formation of a protective barrier of intestinal mucosa and transportation of the intestinal content has been described quite extensively. However, information on the quality composition of mucopolysaccharides and its changes in the intestinal tract of ostrich chicks, especially in the large intestinal segments, is unavailable. In the current study, ostrich embryos/chicks (n=6/36) of both sexes were used shortly before hatching and during the first months of the post-hatch period. Tissues for histology were taken from the large intestine: the medium segments of the caecum, proximal and distal parts of colon. By using histochemical reactions, the differentiation of goblet cells as well as chemical composition of mucopolysaccharides was carried out. The cells contained acid (AB+), neutral (PAS+) and mixed (AB/PAS+) mucopolysaccharides. The number of goblet cells in the large intestine per unit area of mucosa increased towards the cloaca, and it was the highest in the distal part of the colon. The qualitative goblet cell composition in different large intestinal parts was different in all ages. In the caecum, goblet cells containing acid and mixed mucopolysaccharides dominate post-hatch, whereas in the colon, goblet cells containing acid mucopolysaccharides predominated. The most rapid changes in the qualitative goblet cell composition occur during the first week post-hatch when in all the intestinal segments the proportion of cells containing acid mucopolysaccharides continuously increased.

Effect of dietary fibre and protein sources on contractility and morphometry of pig colon

The aim of the study was to investigate the effects of feeding two fibre and two protein sources, differing in rate of fermentation and digestion, on motility and morphology of pig colon. Pigs of 15.1 ± 0.9 kg of BW were fed during 21 days with diets containing potato fibre (PF) or cellulose (CEL) in combination with potato protein concentrate (PPC) or casein (CAS). After slaughter, tissue samples of proximal (C25), middle (C50) and distal (C75) part of the colon were taken for analysis of in vitro mechanical activity and of histological parameters. Spontaneous activity, responses to acetylcholine (ACh), electrical field stimulation (EFS), responses to short chain fatty acids (SCFA) and relaxation induced by single administration of isoproterenol were recorded. Crypt depth and myenteron thickness were measured. The amplitude of spontaneous contractions of colon segments was similar in all groups. In neither colon segment, responses to EFS, SCFA and relaxation induced by isoproterenol were not affected by the sources of fibre and protein. Response to ACh was significantly enhanced in C25 in pigs fed CAS as compared with PPC. The effects of type of dietary fibre and dietary protein on colon morphology differed between the segments and parameters under study. The effect of fibre was not found in C50. The effect of fibre type on colon morphology was of greater magnitude than that of protein but in some parameters interactive effects could be traced. The results suggest that effects of type of dietary fibre and protein on colonic morphology depend on the part of the colon. Fibre and protein sources do not affect motility in middle and distal parts of colon, but protein source affects muscular contractions in proximal colon, assayed in vitro.

Bifidobacterium lactis Bb-12 and Lactobacillus salivarius UCC500 Modify Carboxylic Acid Formation in the Hindgut of Rats Given Pectin, Inulin, and Lactitol

The effect of Bifidobacterium lactis (Bb-12) and Lactobacillus salivarius (UCC500) on the formation of carboxylic acids (CAs) was studied in the hindgut of rats fed pectin, inulin of low solubility, and lactitol. When the pectin diet was supplemented with Bb-12, the formation of CAs was larger throughout the colon of rats, due to increased formation of acetic acid (P < 0.01) and, in the distal part of the colon, also because of propionic and butyric acids (P < 0.01). In rats fed pectin and UCC500, there was a shift in the formation of CAs from the cecum to the distal colon. Thus, the cecal pool of CAs in the rats was lower (P < 0.05), whereas the concentration of CAs in the distal part of colon was larger (P < 0.01) than without this strain. Concerning the slowly fermentable inulin, there was a greater formation of CAs in the cecum (P < 0.05) of rats, especially propionic acid, and a lower formation in the distal part of the colon (P < 0.01) when the diets were supplemented with Bb-12, whereas UCC500 had no effect except for a lower proportion of acetic acid in the distal part of the colon (P < 0.001). In rats fed lactitol and Bb-12, the concentration of CAs was lower in the distal part of colon (P < 0.001) than without this strain, whereas the cecal pool of CAs was greater in rats supplemented with UCC500 (P < 0.001). We conclude that the probiotic bacteria affect the amount, the pattern, and the site of release of CAs in the hindgut of rats, but the combination of pre- and probiotics is of great importance for the outcome.

The development of colon innervation in trisomy 16 mice and Hirschsprung's disease.

To study the colon innervation of trisomy 16 mouse, an animal model for Down's syndrome, and the expression of protein gene product 9.5 (PGP 9.5) in the stenosed segment of colon in Hirschsprung's disease (HD). Trisomy 16 mouse breeding;cytogenetic analysis of trisomy 16 mice; and PG P9.5 immunohistochemistry of colons of trisomy 16 mice and HD were carried out. Compared with their normal littermates, the nervous system of colon in trisomy 16 mice was abnormally developed. There existed developmental delay of muscular plexuses of colon, no submucosal plexus was found in the colon, and there was 5mm aganglionic bowel aparting from the anus in trisomy 16 mice. The mesentery nerve fibers were as well developed as shown in their normal littermates. Abundant proliferation of PGP 9.5 positive nerve fibers was revealed in the stenosed segment of HD colon. Trisomy 16 mice could serve as an animal model for Hirschsprung's disease for aganglionic bowel in the distal part of colon. Abundant proliferation of PGP 9.5 positive fibers resulted from extrinsic nerve compensation, since no ganglionic cells were observed in the stenosed segment of the colon in HD. HD has a genetic tendency.

Absorption of sodium, potassium and water in the colon of the Norway lemming Lemmus lemmus (L.)

Abstract 1. The colon of the lemming has a proximal part forming a post-caecal spiral, and a distal section with three loopes, “parallelschlinge.” 2. The distal part of colon possess mechanisms that effectively absorb water, potassium and sodium, but the larger amount of sodium is absorbed in the post-caecal spiral. 3. In the present communication it is suggested that the water absorption in the colon can be solute linked, but also that anisosmotic conditions between the colon tissue and the feces may participate in water absorption.