共查询到20条相似文献，搜索用时 15 毫秒
1.
M. J. L. Kik J. M. V. M. Mouwen J. F. J. G. Koninkx J. E. van Dijk M. H. van der Hage 《The Veterinary quarterly》2013,33(2):108-115
Summary The literature concerning the effects of plant lectins on the small intestinal epithelium is reviewed. It appears that after oral intake, intact plant lectins can reach the small intestinal lumen. Their binding to the mucosal surface evokes an increased synthesis of glycoproteins and a degeneration of the intestinal epithelium. The epithelial alterations may result in hyperregenerative villus atrophy and endogenous nitrogen loss. These changes ultimately can lead to less efficient feed conversion, diminished growth, scouring, wasting and death. The possible significance of plant lectins in digestive disturbances in farm animals is suggested. 相似文献
2.
Chin K Onishi S Yuji M Inamoto T Qi WM Yamamoto K Warita K Yokoyama T Hoshi N Kitagawa H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(2):193-199
Our previous study clarified that the apical regions of both the follicle-associated epithelium (FAE) of Peyer's patches and the intestinal villi are the only adhesion sites of indigenous bacteria in rat jejuno-ileum. To survey the ligands against bacterial lectins, sugar expression patterns on epithelial cells were lectin-histochemically investigated using 21 lectins in the jejuno-ileal Peyer's patches of rats. As a result, (D-glcNAc)(2-4), detected by Solanum tuberosum (STL) and by Lycopersicon esculentum (LEL), and beta-D-gal(1-3)-D-galNAc detected by Peanut agglutinin (PNA), were strongly expressed on the brush borders of the apical regions of the FAE and the intestinal villi. On the other hand, neither sugar was expressed on the brush borders of the basal regions of both FAE and intestinal villi. The positive intensities for the lectins correlated with the progression of epithelial apoptosis in the FAE and in the intestinal villi. Moreover, the double staining with lectin histochemical method and the in situ nick end-labeling method could simultaneously detect the strong expression of both sugars and nuclear DNA fragmentation in epithelial cells at the late apoptotic stage. Other sugar expression patterns in the intestinal villi were similar with those in the FAE. There were no lectins specific for M cells in the FAE. From these findings, the possible sugars of ligands against some indigenous bacterial lectins, expressing specially on the apoptotic epithelial cells, might be narrowed down in rat jejuno-ileum. 相似文献
3.
Lectin binding to small intestinal goblet cells of newborn, suckling, and weaned pigs 总被引：4，自引：0，他引：4
Lectin binding of small intestinal goblet cells was examined in newborn, suckling, and weaned pigs. Sections of duodenum, proximal portion of the jejunum, distal portion of the jejunum, and ileum were embedded in a hydrophilic acrylic resin and treated with each of the following lectins: Canavalia ensiformis, Ricinus communis I, Glycine max, Ulex europaeus I, and Triticum vulgaris. Percentages of goblet cells binding each lectin were calculated within intestinal regions. Differences in lectin-binding affinity were detected among pigs of various ages and among various intestinal regions within pig age groups. 相似文献
4.
Various pathogens gain access to the intestinal wall via specialized cells, the M cells, found among the follicle-associated epithelial cells overlying the domes of the Peyer's patches. The present study was undertaken to examine the uptake of live Mycobacterium avium subsp. paratuberculosis in the distal small intestine of goat kids. Following laparotomy, distal small intestinal segments of five goats were ligated and injected with bacterial suspension. After 1 hour, the intestinal segments were excised and fixed for light and electron microscopic studies. M. a. paratuberculosis organisms were observed by transmission electron microscopy at locations in the intestinal wall, suggesting transcellular transportation through the M cells. The organisms were present both in the cytoplasm of the M cells and in the cytoplasm of intraepithelial leukocytes found in M-cell pockets. Intercellular bacteria between M cells were occasionally seen. Bacteria were not observed in association with the absorptive epithelium. This study indicates that in goat kids, M. a. paratuberculosis enters the intestinal wall primarily through the M cells in the follicle-associated epithelium of the Peyer's patches. 相似文献
5.
The literature on the glycocalyx of small intestinal epithelium is reviewed. The structure, general and barrier functions, synthesis, and degradation of the glycocalyx, and pathobiological aspects of the glycocalyx in relation to its barrier function are mentioned. Topics for future research are indicated. 相似文献
6.
F Toofanian 《Research in veterinary science》1976,21(3):349-353
Histological changes in the small intestine of 85 ovine fetuses were studied, with particular reference to the mucosa. In 24-day-old fetuses the endoderm of the intestine consisted of a single layer of epithelium. By the 26th day the epithelium was flattened and stratified. The first evidence of rudimentary villus formation was noted in 39-day-old fetuses. Intestinal glands were first observed at 56 days. Other mucosal structures were present by 101 days. At birth the intestinal mucosa was fully mature. 相似文献
7.
K H Wille 《Anatomia, histologia, embryologia》1992,21(3):271-284
The first lysosomes appear in the stratified embryonic intestinal epithelium during its transition into the simple columnar form. This occurs concurrently with the initial villogenesis. Lysosomes situated basally in the epithelium are presumably the precursor of the first giant lysosomes in the lower small intestine of rodents. Immediately after establishment of the simple configuration a special form of secondary lysosomes can be observed, i.e. glycogenosomes, in the ephemerally existing huge glycogen containing areas. During subsequent fetal intestinal development one observes two events in the epithelial cells, which are the same in principle but differ in one essential point, while they exhibit partially impressive structures. On the one hand there are autophagic degenerative lysosomal processes in the villous epithelium until birth, that lead to a surface without villi in the large intestine, where they occur particularly frequently. On the other hand giant lysosomes originate perinatally in the lower small intestine as well as in the caecum and colon ascendens, in which protein molecules, which were transported by a system of inframicrovillar membranes, are lysosomally degraded, which can be defined as a heterophagic event. 相似文献
8.
本研究旨在获得体外培养状态下的猪小肠上皮细胞,研究猪小肠上皮细胞与大豆凝集素的结合情况.选取新生未哺乳健康仔猪,取小肠组织对小肠上皮细胞进行分离培养,并进行纯化.纯化后的细胞以角蛋白抗体-8为—抗进行细胞免疫化学试验鉴定,鉴定后的猪小肠上皮细胞以FITC-SBA为探针进行细胞凝集素荧光标记化学试验,对猪小肠上皮细胞大豆凝集素结合位点进行标记.结果表明:试验分离纯化的细胞经角蛋白抗体-8鉴定为阳性,所分离纯化的细胞为猪小肠上皮细胞,经检测其纯度达90％以上,猪小肠上皮细胞FITC-SBA标记结果为阳性.体外培养的猪小肠上皮细胞表面存在大量的大豆凝集素结合位点,进一步明确了猪小肠上皮细胞是大豆凝集素结合的主要细胞类型之一,为单胃动物大豆凝集索抗营养机制研究提供理论依据. 相似文献
9.
Sigurdardóttir OG Bakke-McKellep AM Djønne B Evensen O 《Comparative immunology, microbiology and infectious diseases》2005,28(3):223-230
The main lesions of paratuberculosis in ruminants are in the small intestine. Previous studies have shown that the bacterium enters the small intestine through M cells found in the follicle-associated epithelium lining the domes of the Peyer's patches. The everted sleeve method, devised for the in vitro study of intestinal absorption, was used in this study to investigate the uptake of Mycobacterium avium subsp. paratuberculosis in goat intestine. Everted small intestinal sleeves of goat kids, prepared from areas with and without Peyer's patches, were incubated for 60 min in 3H-labeled bacterial solution. The results of this study imply that the bacteria can enter the intestinal mucosa of the jejunum, both in areas with and without Peyer's patches. These findings indicate, therefore, that M. avium subsp. paratuberculosis bacteria not only enter through M cells but also through enterocytes. 相似文献
10.
Intraluminal digestive enzymes were shown to bind to chick intestinal epithelial surface (glycocalyx). Affinity of the intestinal epithelium for the enzymes decreased in the order, lipase > amylase > protease. The plant hemagglutinins, Con A, phytohemagglutinin, pokeweed mitogen and raw soybean effectively released lipase and amylase from the glycocalyx. Based on specific inhibition of binding by sugars, such as fucose and N-acetylated sugars, lipase and amylase appeared to be bound to blood group antigen-like sugar moieties on the glycocalyx of the microvilli. 相似文献
11.
H Gelberg H Whiteley G Ballard J Scott M Kuhlenschmidt 《American journal of veterinary research》1992,53(10):1873-1880
A variety of biotinylated lectins was applied to formalin-fixed intestinal sections from isolator-reared pigs ranging in age from newborn through 12 weeks. Lectin binding to brush borders of villus enterocytes, crypt enterocytes, and dome epithelium, and lectin reactivity within goblet cells and Brunner's glands was semiquantified by microscopy and was used to estimate temporal changes in complex carbohydrates of enteric epithelium. Although variability in binding scores often was observed among pigs of the same age, several general patterns of lectin binding were detected. Dolichos biflorus and Ulex europaeus lectins had increasing binding to brush border membranes as pigs aged. The Dolichos biflorus, however, had decreased binding at the 12-week time point. Neuraminidase-treated Arachis hypogaea and Triticum vulgaris were associated with high mean binding scores at all time points. Canavalia ensiformis bound, with high mean score at all time points, to villus but not to crypt enterocytes. Arachis hypogaea was associated with variable but often high binding scores, regardless of pig age. Succinylated wheat germ agglutinin bound more to crypt than to villus enterocytes. Goblet cells were generally less reactive than were corresponding villi and crypts. Dome epithelium reactivity varied with the lectin used, whereas Brunner's glands reacted with all lectins tested. We conclude that age and regional variations in lectin binding may reflect differences in intestinal function and differentiation. Because complex carbohydrates may act as cell surface receptors for a variety of enteric pathogens, our results indicate that these differences may be partially responsible for age and anatomic differences in susceptibility or resistance to enteric disease. 相似文献
12.
Pohlmeyer I Jörns J Schumacher U Van Damme EJ Peumans WJ Pfüller U Neumann U 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2005,52(3):138-146
Carbohydrates on epithelial cell surfaces play an important role as attachment sites for different microorganisms like bacteria, viruses and protozoa. To obtain more information about the distribution of carbohydrates on the luminal surface along the intestine, lectin histochemical studies on different gut segments of chicks of different age groups were carried out using a panel of 13 lectins with specificities for Man, Glc, Gal, GalNAc, GlcNAc or GlcNAc oligosaccharides and Sia. Furthermore, we tried to find out whether previously reported specificities of certain lectins for M cells (membranous or multifold cells) in the bursa of Fabricius (BF) can be observed also on M cells of the intestine. As a result we were able to demonstrate binding of all lectins employed in these studies in all investigated gut segments. In some cases, the application of the same lectin led to varying staining intensities of the same histological structures in different age-groups (e.g. staining of the brush border with WGA, LEA, MAA or Conarva) or different gut segments (e.g. staining of goblet cells with CMA II, LEA and MPA). Hence, terminal carbohydrate residues of glycoconjugates on the intestinal epithelium vary depending on age and organ site. As glycoconjugates can act as attachment sites for microorganisms, these differences in the distribution of sugar residues may be one explanation for the site-specificity of certain pathogens. Furthermore, the binding of lectins to the follicle-associated epithelium (FAE) of the BF differs from that to the FAE of the intestine again stressing the site specificity of lectin binding. Thus, up to now no universal M-cell marker along the chicken intestine exists. 相似文献
13.
Nicarbazin is an anticoccidial drug, used mainly in birds, which can also be used in rabbits. It has been shown to produce several effects, such as inhibition of growth and feed efficiency in poultry. The aim of the present work was to determine whether nicarbazin alters intestinal absorption of sugar. Results obtained show that nicarbazin decreases D-galactose accumulation in the jejunal tissue and increases mucosal to serosal transepithelial fluxes of this sugar, in both cases in a dose-dependent way. Furthermore, nicarbazin seems not to modify the sugar diffusion across the intestinal epithelium. The drug also stimulates the sugar uptake in brush border and basolateral membrane vesicles. The results suggest that in rabbits nicarbazin increases sugar intestinal absorption mediated by carriers. 相似文献
14.
Moxley RA 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2004,5(1):15-33
Cattle are a major reservoir of Escherichia coli 0157:H7, an important zoonotic pathogen that causes hemorrhagic colitis and hemolytic uremic syndrome (HUS). Colonization of cattle occurs predominantly in the large intestine, and may especially target follicle-associated epithelium (FAE) in the terminal rectum. Bacterial colonization involves induction of attaching-effacing (A/E) lesions, mediated by type III secreted proteins and an outer membrane protein called intimin. ToxB, encoded on plasmid pO157, contributes to adherence of E. coli O157:H7 through promotion of the production and/or secretion of type III secreted proteins. Production of type III secreted proteins and intestinal colonization appear to involve quorum-sensing mechanisms. In the human host, E. coli O157:H7 may have a preference for FAE in the distal small intestine. The H7 flagellum induces production of chemokines such as interleukin 8, and neutrophilic infiltration of the intestinal mucosa, which in turn may enhance Shiga toxin (Stx) uptake across the intestinal epithelium. Both Stx and cytokine responses play critical roles in the induction of the vascular lesions that underlie hemorrhagic colitis and HUS. In cattle, Stx binds to intestinal crypt cells and submucosal lymphocytes but not vascular endothelium. The role played by Stx in cattle may be to suppress mucosal immunity, yet enhance other effects that promote intestinal colonization. 相似文献
15.
A 130-week-old male Royal College of Surgeons rat kept as a non-treated animal in a long-term animal study presented with a mass in the hepatic portal region that adhered to a dilated common bile duct and the duodenum. Histopathologically, the solitary mass showed expansive growth with no apparent compression and continued to dilate the common bile duct, which had a hyperplastic epithelium with intestinal metaplasia. The mass mainly consisted of small to large dilated and/or tortuous ducts with abundant dense connective tissue and many inflammatory cells. The single-layer lining epithelium of the duct changed from cuboidal to columnar. Immunohistochemically, the lining cells were positive for cytokeratin 7, cytokeratin 19, and OV-6, which are bile duct markers. Based on the pathological characteristics, the rat was diagnosed as spontaneous cholangiofibrosis adjacent to a dilated common bile duct with intestinal metaplasia. 相似文献
16.
J R Snyder 《Veterinary Clinics of North America: Equine Practice》1989,5(2):247-270
Intestinal edema, luminal distention, and ischemia are common pathologic processes involved in producing the intestinal damage found during surgical exploration for acute abdominal disorders in the horse. The severity of intestinal edema depends on the degree of altered intravascular forces and changes in capillary permeability. Capillary hydrostatic pressure rises as the less pliable venules and veins become occluded during intestinal obstruction. Concurrently, the production of various endogenous products that damage the vascular wall leads to increases in capillary permeability and protein exudation, causing fluid movement into the interstitium and consequent tissue edema. The information presently available indicates that luminal distention does not produce the morphologic damage observed during natural conditions. However, slight intestinal edema was observed with experimental distention of the equine small intestine. Although the effects of increased luminal pressure appear minor, in the overall scheme of intestine damage, many processes are occurring together, and the luminal distention may be additive in the production of intestinal damage. The intestinal damage occurring during natural obstructions is most likely related to both the severity of the ischemia and the subsequent reperfusion injury. Experimentally, an ischemic insult produces a consistent sequence of mucosal alterations to both the equine small and large intestine. Severity of ischemia may be the limiting factor in determining the clinical outcome in cases in which the ischemic insult is irreversible; however, if the intestinal tissue survives the ischemia, the reperfusion injury may substantially increase the damage, producing an irreversible injury. The proposed mechanisms responsible for the reperfusion injury include the presence of highly reactive cytotoxic oxygen radicals. The intestinal epithelium and vascular endothelium are both capable of producing these unstable compounds. Secondly, the influx and activation of neutrophils may also release oxygen radicals. During experimental ischemia, neutrophils gradually move to the affected area; however, during reperfusion their numbers dramatically increase and may play a significant role in producing intestinal damage. Therapy for intestinal damage involves first determining the viability of the affected intestine. All nonviable bowel should be resected and viable intestine anastomosed. The care and maintenance of intestine of questionable viability are presently based on therapy in humans and experimental information concerning the pathophysiologic mechanisms of intestinal ischemia.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
17.
Schleig PM Buergelt CD Davis JK Williams E Monif GR Davidson MK 《Veterinary microbiology》2005,108(3-4):271-279
Mycobacterium avium spp. paratuberculosis (MAP) causes chronic granulomatous inflammation of the intestinal tract in many species of animals, but the mechanisms of disease are poorly understood. Attachment of bacteria to epithelial cells is a critical step in pathogenesis of many mucosal diseases. The goal of these studies was to develop an in vitro method to study attachment of MAP to bovine intestinal epithelial cells. Short-term, bovine intestinal organ cultures were used to show a significant difference in the ability of radiolabelled MAP strains to attach to intestinal epithelium. We found significant differences in the ability of different strains of MAP to attach, but there were no differences in attachment among different regions of the intestinal tract. Examination of acid fast stained tissue sections of organ cultures demonstrated that organisms were located adjacent to mucosal epithelium or within goblet cells. Coating of the organisms with fibronectin, which has been shown to be involved in attachment of many mycobacteria, including MAP, affected the attachment of the MAP strains in different ways, but did not affect the overall attachment of the organisms to different regions of the gastrointestinal tract. This organ culture method should also prove useful for defining the molecular mechanisms of attachment and interactions of MAP with intestinal epithelium. 相似文献
18.
糖基化修饰是生命体中最重要的一种蛋白质翻译后修饰之一，对生命体起着非常重要的作用。糖蛋白上的糖基可以作为凝集素的结合位点，因此凝集素可以用来鉴别和分析糖链结构，作为糖基化分析方法如质谱法的重要补充。本试验旨在建立和优化研究猪肠道糖基化修饰的荧光凝集素免疫组化方法，并应用该方法研究猪不同肠段糖基化修饰的差异以及断奶对仔猪肠道糖基化修饰的影响。结果表明：①荧光凝集素免疫组化方法最适条件为：切片脱蜡后，封闭切片30 min，采用5 μg/mL FITC标记植物凝集素（FITC-Lectin）室温孵育1 h，以含有DAPI的封片剂进行封片。该方法具有灵敏度高、特异性好以及定量更为多元化的特点。②生长猪回肠和结肠中糖基化修饰模式不同，回肠主要以岩藻糖、N-乙酰葡萄糖胺为主，而结肠中主要以N-乙酰葡萄糖胺、岩藻糖和甘露糖为主。除甘露糖分布在非杯状细胞的肠上皮细胞和固有层外，岩藻糖和N-乙酰葡萄糖胺主要分布在肠绒毛表面和杯状细胞中。③22~28日龄仔猪回肠中N-乙酰葡萄糖胺的含量随着仔猪日龄的增加而增加（P<0.05），断奶显著降低了28日龄仔猪回肠中N-乙酰葡萄糖胺的含量（P<0.05）。综上所述，本研究成功建立猪肠道糖基化修饰的研究方法，并通过此方法发现仔猪回肠中N-乙酰葡萄糖胺可作为肠道屏障功能完善的标志之一。 相似文献
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20.
We investigated the ability of a high virulence (STR 357) and a low virulence (STR 598) strain of Streptococcus gallolyticus to attach to the intestinal tract of pigeons. For that purpose, first of all, two groups of six pigeons were anesthetized and ligatures were placed at the beginning of duodenum, jejunum, ileum, and colon. The obtained intestinal loops of the birds of the first and second group were injected with S. gallolyticus strains STR 357 and STR 598, respectively. At 15, 30, and 60 min postinoculation, two pigeons of each group were euthanatized and the various intestinal loops were sampled for histologic, immunohistochemical, and electron microscopic examination. Both the high and low virulence strains were able to adhere to the intestinal mucosa. Indeed, all samples dearly showed numerous coccal-shaped bacteria that stained positively with S. gallolyticus antiserum and were lining up against the intestinal epithelium. Likewise, on electron microscopic examination, cocci were seen in the mucus covering the intestinal epithelium. Second, the association of S. gallyticus strains of differing virulence with the intestinal tissue was determined quantitatively. Experiments were performed as described above. The number of S. gallolyticus bacteria that adhered to the intestinal epithelium was determined by plating out 10-fold serial dilutions of the segments. No significant differences in the number of adhered bacteria were found between the strains of high and low virulence. 相似文献