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Experimental Stomatology
Published in Samuel Dreizen, Barnet M. Levy, Handbook of Experimental Stomatology, 2020
Samuel Dreizen, Barnet M. Levy
The deficient animals had shallow ulcers on the dorsum and undersurface of the tongue, lips, pharynx, and gingiva. There were superficial microscopic ulcerations in the GI tract where the intestinal villi were thickened, blunted, widened, swollen, occasionally fused, and always heavily infiltrated with acute and chronic inflammatory cells. Mucosal integrity of the control animals was protected by inclusion of daily supplements of folic acid. The major defect in folic acid deficiency at the cellular level is impaired production of DNA expressed as inefficient mitosis, increase in cellular stroma, and asynchronism between protein synthesis and cell division. Marmosets deprived of folic acid had an exceedingly high incidence of oral infections. These were most severe in the animals that were also given injections of methotrexate. The marked propensity to oral infections was attributed to the breakdown in tissue barriers to infection and to the immunosuppression resulting from deficiency-induced leukopenia (Figure 5B).
Gastrointestinal Lymphatics
Published in Waldemar L. Olszewski, Lymph Stasis: Pathophysiology, Diagnosis and Treatment, 2019
The characteristic structure of the mammalian small intestinal mucosa is the villus. There is considerable interspecies variation in its morphology: rat villi are flattened leaf-shaped structures while rabbit villi are tongue-shaped. Cat and dog villi are finger-shaped, the cat villi being more slender. Human villi show great variation in structure with short and long fingers, tongue shapes, and broad villus ridges, suggesting fusion of adjacent finger-shaped villi. The structure of intestinal villi and the morphology of their microcirculation has recently been reviewed by Casley-Smith and Gannon.24
Macromolecular Absorption From The Digestive Tract In Young Vertebrates
Published in Károly Baintner, Intestinal Absorption of Macromolecules and Immune Transmission from Mother to Young, 2019
In the fish, intestinal villi are substituted by mucosal folds. Fish larvae are stomachless; in the family Cyprinidae even the adults are lacking stomach. Several species, mostly herbivorous fishes, have ceca.
Radioprotective effect of mistletoe extract on intestinal toxicity: in vivo study using adult zebrafish
Published in International Journal of Radiation Biology, 2023
Sunmin Park, Suhyun Kim, Soonil Koun, Hae-Chul Park, Won Sup Yoon, Chai Hong Rim
The main endpoints of the study were survival and degree of deformation of the intestinal villi. After irradiation, zebrafish were screened and scored daily for activity and survival. We aimed to sacrifice the fish 10 d post-irradiation; however, they were sacrificed after 7 d post-irradiation if the activity was significantly reduced. Isolated intestines were fixed in 4% paraformaldehyde and sectioned into 4-mm slices to histologically observe the intestine. Hematoxylin and eosin (H&E) staining was used to observe intestinal structures. All stained images were obtained using a slide scanner (3DHISTECH/Pannoramic scan2). The post-irradiated deformity of intestinal villi was graded as normal (N), no deformity of villi; light (L), cracks in the villi outlines, and the shortening of the villi within 30%; moderate (M), a significant portion of villi shortened in the range of 30–50%; significant (S), a significant portion of villi shortened by more than 70%, or there was a part where the basal layer was exposed, or the basic structure of the villi, including goblet cells and fibrovascular cores was disrupted. Since there could be subjectivity issues in determining the degree of villus deformity, three researchers (CHR, SMP, and SHK) evaluated it independently. Differences in the evaluation were resolved through discussion and reevaluation.
Effect of adding Dunaliella algae to fish diet on lead acetate toxicity and gene expression in the liver of Nile tilapia
Published in Toxin Reviews, 2021
Sabreen Ezzat Fadl, Nagwan El-Habashi, Doaa Mohammed Gad, Walaa Mohammed Elkassas, Zizy Ibrahim Elbialy, Doaa Hosny Abdelhady, Sayed Mohammed Hegazi
On the other hand, Dunaliella-supplemented group (group D) showed normal hepatopancreas (Figure 4(a)), spleen (MMCs size was less than that exposed to lead acetate and contained other cells than those of MM cells) (Figure 4(b)), stomach and intestine were normal and the intestinal villi were elongated (Figure 4(c)). Dunaliella supplemented and exposed to 5 mg lead acetate/liter group (group D5) revealed mild congestion, mild to moderate vacuolation of hepatocytes (Figure 4(a1)) and focal mild necrosis of hepatocytes. Spleen showed normal lymphocytic cells population and a mild increase in MMCs size and congestion (Figure 4(b1)), which were less than those observed in 5 mg lead acetate/liter-exposed group (group C5). Normal stomach and intestine were noticed except for mild necrosis at the tips of the intestinal villi in few sections (Figure 4(c1)). Dunaliella supplemented and exposed to 10 mg lead acetate/liter group (group D10) revealed mild congestion, moderate vacuolation of the hepatocytes, and mild nuclear pyknosis. Few sections showed focal perivascular heterophils infiltrations and loss of the normal architecture (Figure 4(a2)). Spleen showed normal lymphocytic cells population and mild congestion and MMCs were of normal size (Figure 4(b2)). The stomach and intestine were almost normal except for mild necrosis of the gastric mucosa and atrophy of the gastric glands (Figure 4(c2)).
Gut microbiota: what is its place in pharmacology?
Published in Expert Review of Clinical Pharmacology, 2019
Aleksandra Tarasiuk, Jakub Fichna
In the stomach, which is lined with a single layer of squamous epithelium, its cells are responsible for the secretion of hydrochloric acid, digestive enzymes, and mucus. In the small intestine, a thick type of epithelium is present – single-layer cubic or columnar, constituting a natural protective barrier. It performs both secretory and transport functions, related to the absorption of many substances. The epithelial surface in the small intestine is characterized by the presence of numerous cavities and folds, formed by glands, crypts, and villi, which is an expression of the adaptation of this part of the GI tract to the function performed. The epithelium of the intestinal villi consists of capillary epithelial cells. It is formed by single tentacles, so-called microvilli that also increase its surface. Under the epithelium of the villi, in the middle of the lamina propria, a network of lymph vessels is located. Enterocytes are alternated with intestinal goblet cells secreting mucus. The core of the intestinal villi consists of cylindrical, straight cavities that extend to the muscular layer but are not penetrating. At the bottom of the crypts there are stem cells, and above them, Paneth cells, secreting antibacterial lysozyme. The epithelium located above the lymphoid cells of the intestine, in which Peyer’s patches are present, is a characteristic area of the intestine due to the microcavities and microfold cells located there. The main role of these cells is both the recovery of shortened or irregular villi or pits, as well as the transport of microorganisms from the intestinal lumen to deeper epithelial layers.