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Obstructive jaundice alters LFA-1alpha expression in rat small intestine

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Abstract

Translocation of bacteria and endotoxtin has long been documented in obstructive jaundice, and altered intestinal barrier function is considered to be one of the important mechanisms for this phenomenon. The regulation of gastrointestinal mucosal response to injury is thus of important clinical as well as biological relevance. Integrins play a critical role in enterocyte migration, which is essential to mucosal healing. This study is designed to evaluate the integrins status in obstructive jaundice. Male Sprague-Dawley rats (N = 37) were randomized to three groups. Group 1 (N = 12) underwent common bile duct ligation (CBDL), group 2 (N = 12) underwent common bile duct ligation with oral glutamine administration (CBDL + G), and group 3 (N = 13) underwent a sham operation (sham control). After seven days, segments of proximal jejunum and distal ileum were harvested, and cell surface immunohistochemical expression of LFA-1alpha and VLA-6 were evaluated and recorded. The staining intensities were graded on a scale of 0-4. Comparisons among the three groups were performed. There was no significant difference in VLA-6 staining on small intestine among the three groups (P > 0.05). There was also no significant difference in LFA-1alpha staining the on jejunum between group 1 (CBDL) and group 3 (sham control) (P > 0.05). However, the LFA-1alpha staining on the ileum in group 1 (CBDL) significantly decreased when compared with group 3 (sham control) (P = 0.008). With oral glutamine administration (0.2 g/kg body weight, once daily), LFA-1alpha staining on the ileum was significantly restored in group 2 (CBDL + G). In conclusion, obstructive jaundice for one week down-regulates LFA-1alpha expression on rat ileum. With oral glutamine administration, such down-regulation of LFA-1alpha expression on rat ileum can be restored. Such a phenomenon is intriguing and deserves further evaluation and elucidation.

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... By using sterile techniques, a mid-line incision was made, the common bile duct was identified, double ligated with 5-0 silk and divided between the two ligatures212223242526 . In shamoperated animals, the common bile duct was freed from the surrounding soft tissue without ligation and transection. ...
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The use of avidin-biotin interaction in immunoenzymatic techniques provides a simple and sensitive method to localize antigens in formalin-fixed tissues. Among the several staining procedures available, the ABC method, which involves an application of biotin-labeled secondary antibody followed by the addition of avidin-biotin-peroxidase complex, gives a superior result when compared to the unlabeled antibody method. The availability of biotin-binding sites in the complex is created by the incubation of a relative excess of avidin with biotin-labeled peroxidase. During formation of the complex, avidin acts as a bridge between biotin-labeled peroxidase molecules; and biotin-labeled peroxidase molecules, which contains several biotin moieties, serve as a link between the avidin molecules. Consequently, a "lattice" complex containing several peroxidase molecules is likely formed. Binding of this complex to the biotin moieties associated with secondary antibody results in a high staining intensity.
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Freeze fracture replicas of the plasma membrane and tight junctions of epithelial cells of the terminal ileum from 10 patients with Crohn's disease involving the small bowel and from the terminal ileum of two patients without inflammatory bowel disease were studied to determine if significant morphological variations could be documented. Samples of diseased tissue were taken from: 1) macroscopically normal ileal resection margins, 2) pinpoint aphthoid ulcers, 3) small 5 mm ulcers, 4) cobblestone mucosa. Samples of ileal mucosa from the proximal margin of ileocolic resections for carcinoma of the right colon were identically processed and served as controls. Control specimens showed normal villus structures lined by absorptive and goblet cells linked to adjacent cells by four to seven tight junction strands, arranged as an anastomosing network of fibrils oriented perpendicularly to the long axis of the cell. Crohn's disease specimens taken from the cobblestone area displayed the greatest degree of tight junction disorganization. Tight junctions commonly formed bizarre patterns, were fragmented, and often showed misalignment in a direction parallel to the cell axis. Specimens taken from areas 2 and 3 displayed a less severe form of tight junction rearrangement. Junctional strand fragmentations, as well as areas of plasma membrane lacking strands, were apparent. The resection margins had minor irregularities in junctional structure in some, but not all, cases. The predominant alteration in those cases which showed change was varying degrees of strand fragmentation. We postulate that the tight junction abnormalities of epithelial cells from the terminal ileum of patients with Crohn's disease may contribute to a disturbance in barrier functions.
Article
Fifteen clinical and laboratory parameters in 155 consecutive patients having bile duct surgery over a 3 year period were analyzed in an effort to define the factors associated with a poor outcome and to define the subpopulation of patients at greatest risk. Ten of the 15 parameters evaluated were found to correlate significantly (p < 0.05) with hospital mortality. Five or more risk factors correlated significantly with mortality (p < 0.0001) and with postoperative renal failure, bacteremia and upper gastrointestinal hemorrhage (p < 0.005). This risk-factor analysis has the advantages of providing information rapidly and employing only clinical observations and readily available laboratory tests. Patients with five or more risk factors should be considered for preoperative percutaneous transhepatic decompression.
Article
It is now established that certain nutrients have a significant effect on cellular metabolism and growth, tissue repair and regeneration, and modulation of host defences. So far, however, potential clinical benefits have been difficult to demonstrate. Nevertheless, the use of nutrients in combinations seems to have promise and may be associated with a reduction in infectious complications and length of hospital stay. Nutritional pharmacology in the future may be able to improve tumour response to chemotherapy and may minimize the metabolic effect of cachexia.
Article
Epithelial cells of the intestine seem to act as antigen-presenting cells to surrounding lymphoid tissue and may be crucial to maintain the pool of peripheral T lymphocytes. The scope of this study was to carry out an immunophenotypic and ultramicroscopic analysis of purified human enterocytes to elucidate their role as antigen-presenting cells, in the immune responses in the gut-associated lymphoid tissue. A method has been developed to obtain purified and viable human enterocyte populations, later labeled with relevant monoclonal antibodies directed to leukocyte antigens and subjected to cytofluorometric analysis. Phenotypic analysis revealed the presence of markers common to "classical" antigen-presenting cells (CD14, CD35, CD39, CD43, CD63 and CD64), reinforcing the idea that enterocytes may act as such. Moreover, several integrins (CD11b, CD11c, CD18, CD41a, CD61 and CD29) were also found. CD25 (IL-2 receptor alpha chain) and CD28, characteristic of T cells, were detected on the surface of these cells; this latter finding rises the possibility that enterocytes could be activated by IL-2 and/or via CD28 through binding to its ligands CD80 or CD86. Finally, the presence of CD21, CD32, CD35 and CD64 that may bind immune complexes via Fc or C3, suggests their participation in the metabolism of immune complexes. Furthermore, the finding of a Birbeck's-like granule in the cytoplasm of the cells, shows that enterocytes contain an ultramicroscopic feature previously thought to be characteristic of Langerhans' cells, an antigen-presenting cell. The phenotype detected on the surface of enterocytes, along with their ultramicroscopic characteristics, suggests that they may play an important role in the immune responses elicited in the gut, presenting antigens to surrounding lymphoid cells, and establishing cognate interactions with them.
Article
Background: There is a high incidence of perioperative morbidity and mortality in patients with obstructive jaundice. The absence of bile in the gastrointestinal tract promotes bacterial overgrowth and the increased translocation of bacteria and endotoxin to the liver which has been postulated to inhibit Kupffer cell function in these patients. But, biliary tract obstruction can directly damage liver cells and thus alter their function. Thus, we hypothesized that obstructive jaundice alone alters Kupffer cell function independent of the effects of bacterial translocation. This study was designed to evaluate the contribution of bacterial translocation to the altered Kupffer cell function observed in patients with obstructive jaundice. Methods: Sprague-Dawley rats were randomized to three groups of six animals each. Group 1 underwent common bile duct ligation with intestinal bile salt replacement (sodium taurocholate 100 mg/kg/day) via gastrostomy and an implantable osmotic pump (CBDL + bile salts), Group 2 underwent common bile duct ligation with normal saline replacement (CBDL + saline), and Group 3 underwent a sham operation (sham control). After 7 days, tissue and blood were collected for bacterial translocation and biochemical analyses. Examination of cultured Kupffer cell function included measuring the phagocytosis of heat-killed Candida albicans and endotoxin (LPS)-induced TNFalpha and nitric oxide production. Results: While bacterial translocation and cecal bacterial counts were significantly increased in the CBDL + saline group, these parameters were both reduced to control levels following intestinal bile salt replacement (CBDL + bile salts). Altered Kupffer cell function, as measured by the increased phagocytosis of C. albicans and LPS-induced NO production, and decreased LPS-induced TNFalpha production were observed in all animals with obstructive jaundice regardless of bile salt replacement. Conclusion: Kupffer cell function appears to be differentially affected by obstructive jaundice and these altered functions can occur independent of bacterial translocation.
Article
There is a high incidence of perioperative morbidity and mortality in patients with obstructive jaundice due to sepsis. Tumor necrosis factor-a (TNF-alpha) is considered a crucial mediator in inducing and processing the inflammatory cascade. We hypothesize that obstructive jaundice leads to an increased endotoxin-induced TNF-alpha production and that intestinal bile acid replacement can prevent this phenomenon. Sprague-Dawley rats were randomized to three groups of 12 animals each. Group 1 underwent common bile duct ligation (CBDL) with oral intestinal bile acid (deoxycholic acid 5 mg/100 g body weight/3 times daily) replacement (CBDL + bile acid); group 2 underwent common bile duct ligation with the same amount of normal saline replacement orally (CBDL + saline); and group 3 underwent a sham operation (sham control). After 2 days, endotoxin was given to the animals, and after 90 minutes, tissues (liver and lung) and blood were collected for checking the TNF-alpha levels and biochemical analyses. Comparisons among these three groups were performed and recorded. While serum and tissue (liver and lung) TNF-alpha levels of group 2 (CBDL + saline) were significantly increased after endotoxin challenge, these elevations were reduced to control levels (sham control) following oral replacement of intestinal bile acid (CBDL + bile acid). Obstructive jaundice leads to an increased endotoxin-induced TNF-alpha production and intestinal bile acid replacement can inhibit this phenomenon.
P1: ZBU pp692J-ddas-467461 DDAS
  • Sheen-Chen Et
  • Al
P1: ZBU pp692J-ddas-467461 DDAS.cls May 9, 2003 13:41 SHEEN-CHEN ET AL
Obstructive jaundice promotes bacterial translocation from the gut
  • Ea Deitch
  • K Sitting
  • R Berg
  • Rd Spegaw
New perspectives in cell adhesion: RGD and integrins
  • E Ruoslshti
  • Md Pierschbacher