| 1. |
|
|
| 2. |
- Melgar, S, et al.
(författare)
-
Cytolytic capabilities of lamina propria and intraepithelial lymphocytes in normal and chronically inflamed human intestine
- 2004
-
Ingår i: Scandinavian Journal of Immunology. - : Wiley. - 0300-9475 .- 1365-3083. ; 60:1-2, s. 167-177
-
Tidskriftsartikel (refereegranskat)abstract
- Cell-mediated lymphocyte cytotoxicity in ileum and colon of patients with ulcerative colitis (UC), Crohn's disease (CD) and controls was investigated. Frequencies of cells expressing perforin and Fas-ligand (FasL) were determined by immunomorphometry. mRNA expression of perforin, granzyme B and FasL in T cells and subsets was assayed by reverse transcriptase-polymerase chain reaction. Cytotoxicity of intraepithelial and lamina propria lymphocytes was analysed without ex vivo activation in three functional assays: (1) anti-CD3-dependent T-cell receptor (TCR)-/CD3-mediated redirected cytotoxicity, (2) Fas-/FasL-mediated TCR-/CD3-independent cytotoxicity and (3) natural killer (NK) cell cytotoxicity. Inflammation in ileum of CD patients caused increased frequency of perforin-expressing cells and enhanced perforin-dependent TCR-/CD3-mediated cytotoxicity. In contrast, lymphocytes in the inflamed colon of UC or Crohn's colitis patients did not display this cytotoxicity nor did lymphocytes of normal colon. Normal colon lymphocytes showed spontaneous Fas-/FasL-mediated cytotoxicity. This activity was retained but not enhanced in inflamed UC colon. In contrast, a significant increase of FasL-expressing cells was seen in situ. Inflammation did not induce NK cell activity in colonic lymphocytes. Intestinal lymphocytes comprise effectors active in two different cytolytic processes. 'Classical' cytotoxic T lymphocytes in small intestine and lymphocytes executing TCR-/CD3-independent FasL-/Fas-mediated killing of unknown biological role present throughout the intestinal mucosa. Ongoing normal cytolytic processes seem to be enhanced by chronic inflammation.
|
|
| 3. |
|
|
| 4. |
- Danielsson, Ravi, et al.
(författare)
-
Quantification, of photosystem I and II in different parts of the thylakoid membrane from spinach
- 2004
-
Ingår i: Biochimica et Biophysica Acta - Bioenergetics. - : Elsevier BV. - 0005-2728. ; 1608:1, s. 53-61
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract: Electron paramagnetic resonance (EPR) was used to quantify Photosystem I (PSI) and PSII in vesicles originating from a series of well-defined but different domains of the thylakoid membrane in spinach prepared by non-detergent techniques. Thylakoids from spinach were fragmented by sonication and separated by aqueous polymer two-phase partitioning into vesicles originating from grana and stroma lamellae. The grana vesicles were further sonicated and separated into two vesicle preparations originating from the grana margins and the appressed domains of grana (the grana core), respectively. PSI and PSII were determined in the same samples from the maximal size of the EPR signal from P700(+) and Y-D(.), respectively. The following PSI/PSII ratios were found: thylakoids, 1.13; grana vesicles, 0.43; grana core, 0.25; grana margins, 1.28; stroma lamellae 3.10. In a sub-fraction of the stroma lamellae, denoted Y-100, PSI was highly enriched and the PSI/PSII ratio was 13. The antenna size of the respective photosystems was calculated from the experimental data and the assumption that a PSII center in the stroma lamellae (PSIIbeta) has an antenna size of 100 Ch1. This gave the following results: PSI in grana margins (PSIalpha) 300, PSI (PSIbeta) in stroma lamellae 214, PSII in grana core (PSIIalpha) 280. The results suggest that PSI in grana margins have two additional light-harvesting complex 11 (LHCII) trimers per reaction center compared to PSI in stroma lamellae, and that PSII in grana has four LHCII trimers per monomer compared to PSII in stroma lamellae. Calculation of the total chlorophyll associated with PSI and PSII, respectively, suggests that more chlorophyll (about 10%) is associated with PSI than with PSII. (C) 2003 Elsevier B.V. All rights reserved.
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- El-Salhy, M, et al.
(författare)
-
Neuroendocrine peptide levels in the gastrointestinal tract of mice after unilateral cervical vagotomy
- 2000
-
Ingår i: Regulatory Peptides. - 0167-0115 .- 1873-1686. ; 88:1-3, s. 15-20
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of left and right unilateral cervical vagotomy on the content of several neuroendocrine peptides were studied in different parts of the murine gastrointestinal tract, known to receive vagal innervation. The neuroendocrine peptides investigated were secretin, gastric inhibitory peptide (GIP), gastrin, motilin, peptide YY (PYY), somatostatin, substance P, VIP, neurotensin, neuropeptide Y (NPY), and galanin. The neuroendocrine peptide concentration was affected after both left and right vagotomy, and that the changes in the concentrations of the neuroendocrine peptide levels occurred in all the gastrointestinal segments investigated, namely antrum, small and large intestine. However, these changes varied, depending on which side was vagotomized and the interval after vagotomy. It is concluded that the vagus nerve had an important impact on the neuroendocrine system in the murine gut. It is suggested, furthermore that the contradictory results obtained earlier on the effect of vagotomy on the gastrointestinal peptides may depend on differences in the vagotomy methods used and on differences in observation time after vagotomy.
|
|
| 9. |
|
|
| 10. |
- Fahlgren, Anna, et al.
(författare)
-
β-Defensin-3 and -4 in intestinal epithelial cells display increased mRNA expression in ulcerative colitis
- 2004
-
Ingår i: Clinical and Experimental Immunology. - Oxford : Blackwell Publishing. - 0009-9104 .- 1365-2249. ; 137:2, s. 379-385
-
Tidskriftsartikel (refereegranskat)abstract
- mRNA expression of two recently described human beta-defensins (hBD-3 and hBD-4) in epithelial cells of normal small and large intestine and the impact of chronic intestinal inflammation on their expression levels was investigated. Intestinal specimens from patients with ulcerative colitis (UC), Crohn's disease (CD) and controls with no history of inflammatory bowel disease were studied. hBD-3 and hBD-4 mRNAs were determined in freshly isolated epithelial cells by real-time quantitative reverse transcription-polymerase chain reaction (QRT-PCR) and by in situ hybridization. The effect of proinflammatory cytokines on hBD-3 and hBD-4 mRNA expression in colon carcinoma cells was also investigated. Purified epithelial cells of normal small and large intestine expressed both hBD-3 and hBD-4 mRNA, with higher expression levels of hBD-3 mRNA. In situ hybridization revealed higher levels of mRNA expression in the crypt- compared to the villus/luminal-compartment. Interferon (IFN)-gamma, but not tumour necrosis factor (TNF)-alpha or IL-1beta, augmented hBD-3 mRNA expression. None of these agents stimulated hBD-4 expression. Colonic epithelial cells from patients with UC displayed a significant increase in hBD-3 and hBD-4 mRNA compared to epithelial cells of controls. In contrast, small intestinal epithelial cells from CD patients did not show increased expression levels compared to the corresponding control cells. Moreover, Crohn's colitis did not show increased expression of hBD-4 mRNA, while the data are inconclusive for hBD-3 mRNA. We conclude that the chronic inflammatory reaction induced in the colon of UC patients enhances hBD-3 and hBD-4 mRNA expression in the epithelium, whereas in CD this is less evident.
|
|
