| 1. |
- Bjursten, Malin, 1976, et al.
(författare)
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Long-term treatment with anti-alpha 4 integrin antibodies aggravates colitis in G alpha i2-deficient mice.
- 2005
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Ingår i: European journal of immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 35:8, s. 2274-83
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Tidskriftsartikel (refereegranskat)abstract
- Targeted deletion of the heterotrimeric G protein, Galphai2, in mice induces lethal colitis closely resembling ulcerative colitis. In chronic colitis, migration of circulating leukocytes into the intestinal mucosa is partially dependent on alpha4 integrins. In previous studies, short-term administration of anti-alpha4 integrin antibodies has been shown to attenuate intestinal inflammation, and here we elucidate the effect of long-term administration of anti-alpha4 integrin antibodies on colitis in Galphai2(-/- )mice. Long-term blockade of alpha4 integrin significantly increased the severity of colitis in Galphai2(-/-) mice. The inflammation was confined to the colon, associated with increased cancer in situ, destruction of crypt architecture, and increased production of IL-1beta, TNF-alpha and IFN-gamma. Blockade of alpha4 integrin reduced the recruitment of activated T cells to the small intestine. In strong contrast, there were significantly higher numbers of activated T cells in the colonic lamina propria and epithelium, most probably due to in situ proliferation. Furthermore, treatment with alpha4 integrin antibodies induced decreased levels of total IgA and IgG in sera, whereas total IgM levels were unchanged. These new findings may have implications in the understanding of the progression of chronic intestinal inflammation.
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| 2. |
- Bjursten, Malin, 1976, et al.
(författare)
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Transfer of colitis by Galphai2-deficient T lymphocytes: impact of subpopulations and tissue origin.
- 2005
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Ingår i: Inflammatory bowel diseases. - 1078-0998. ; 11:11, s. 997-1005
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Tidskriftsartikel (refereegranskat)abstract
- To elucidate the potential cell population(s) involved in the induction of colitis in inhibitory G protein Galphai2(-/-) mice, Galphai2-deficient or competent bone marrow or splenic and mesenteric lymph node (MLN) T cells were transferred into immunodeficient mice. The mice were followed up to 23 weeks after transfer, recording changes in body weight. Colitis was graded on hematoxylin and eosin-stained colonic tissue, and production of serum interleukin-18 and colon-derived interferon-gamma was measured using ELISA. After adoptive transfer of Galphai2(-/-) bone marrow, severe colitis developed in irradiated wild type recipients, whereas irradiated Galphai2(-/-) mice increased their life span more than 3 times after transfer of wild type bone marrow, accompanied by significant amelioration of colitis. Neither purified Galphai2(-/-) CD4(+), nor CD8(+) splenic or MLN-derived T cells could induce colitis in recombination-activating gene V(RAG) 2(-/-) recipient mice, whereas transfer of splenic Galphai2(-/-) CD3(+) T cells induced severe colitis. In contrast, transfer of Galphai2(-/-) CD3(+) T cells from the MLN caused only minor histopathological changes in the intestinal mucosa. Finally, serum levels of interleukin-18 and interferon-gamma production from colonic tissue cultures correlated well with disease severity. Our results show that bone marrow transplantation can prolong the life of Galphai2(-/-) mice and ameliorate intestinal inflammation. Splenic CD4(+) or CD8(+) T cells on their own were poor inducers of colitis, whereas the combination of both was highly involved in the induction of intestinal inflammation. Furthermore, we show that the tissue origin of CD3(+) T cells is critical for their potency to induce colitis.
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| 3. |
- Dahlgren, Eva, et al.
(författare)
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Sertoli-Leydig cell tumour in a postmenopausal woman showing all facets of the insulin resistance syndrome (IRS)
- 2005
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Ingår i: Ups J Med Sci. - 0300-9734. ; 110:3, s. 233-6
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Tidskriftsartikel (refereegranskat)abstract
- Sertoli-Leydig cell tumours are rare sex stromal tumours with an incidence of < 0.5% of all ovarian tumours. Most frequently this tumour occurs in young women with a history of amenorrhoea, hirsutism and lowered pitch. Here, we report on a woman with IRS, postmenopausal virilization and increased testosterone levels due to a Sertoli-Leydig cell tumour. This is the first case to suggest an association between IRS and Sertoli-Leydig cell tumours. Furthermore, we highlight the difficulties in detecting this ovarian tumour with sonography.
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| 4. |
- Elgbratt, Kristina, 1969, et al.
(författare)
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Aberrant T-cell ontogeny and defective thymocyte and colonic T-cell chemotactic migration in colitis-prone Galphai2-deficient mice
- 2007
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Ingår i: Immunology. - : Wiley. - 0019-2805 .- 1365-2567. ; 122:2, s. 199-209
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Tidskriftsartikel (refereegranskat)abstract
- Galphai2-deficient mice, which spontaneously develop colitis, have previously been reported to have an increased frequency of mature, single positive thymocytes compared to wild-type mice. In this study we further characterized the intrathymic changes in these mice before and during overt colitis. Even before the onset of colitis, Galphai2(-/-) thymi weighed less and contained fewer thymocytes, and this was exacerbated with colitis development. Whereas precolitic Galphai2(-/-) mice had unchanged thymocyte density compared to Galphai2(+/-) mice of the same age, this was significantly decreased in mice with colitis. Thymic atrophy in Galphai2(-/-) mice involved mainly the cortex. Using a five-stage phenotypic characterization of thymocyte maturation based on expression of CD4, CD8, TCRalphabeta, CD69 and CD62L, we found that both precolitic and colitic Galphai2(-/-) mice had significantly increased frequencies of mature single-positive CD4(+) and CD8(+) medullary thymocytes, and significantly reduced frequencies and total numbers of immature CD4(+) CD8(+) double-positive thymocytes compared to Galphai2(+/-) mice. Furthermore, cortical and transitional precolitic Galphai2(-/-) thymocytes showed significantly reduced chemotactic migration towards CXCL12, and a trend towards reduced migration to CCL25, compared to wild-type thymocytes, a feature even more pronounced in colitic mice. This impaired chemotactic migration of Galphai2(-/-) thymocytes could not be reversed by increased chemokine concentrations. Galphai2(-/-) thymocytes also showed reduced expression of the CCL25 receptor CCR9, but not CXCR4, the receptor, for CXCL12. Finally, wild-type colonic lamina propria lymphocytes migrated in response to CXCL12, but not CCL25 and, as with thymocytes, the chemokine responsiveness was significantly reduced in Galphai2(-/-) mucosal lymphocytes.
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| 5. |
- Fredin, Maria Fritsch, 1970, et al.
(författare)
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The application and relevance of ex vivo culture systems for assessment of IBD treatment in murine models of colitis
- 2008
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Ingår i: Pharmacological Research. - : Elsevier BV. - 1043-6618 .- 1096-1186. ; 58:3-4, s. 222-231
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the relevance of mouse ex vivo cultures as a first screening model for new therapeutic agents of Inflammatory Bowel Disease (IBD). Two murine models (dextran sodium sulphate (DSS)-induced colitis and Gαi2-deficient mice) and two anti-inflammatory agents (methyl-prednisolone and the proteasome inhibitor MG132) were evaluated. The in vivo effects of methyl-prednisolone were assessed in both models. Ex vivo colonic tissue from both mouse models were cultured in the presence or absence of the drugs and TaqMan Low-Density arrays were used to assess the regulation of inflammatory genes before and after drug treatment. Colitis induced a similar inflammatory gene profile in both mouse models in in vivo studies and in ex vivo cultures. The differences encountered reflected the different phases of colitis in the models, e.g. innate cytokine/chemokine profile in the DSS model and T cell related markers in Gαi2-deficient mice. After steroid treatment, a similar pattern of genes was suppressed in the two mouse models. We confirmed the suppression of inflammatory gene expression for IL-1β, IL-6 and iNOS in ex vivo and in vivo colons from both mouse models by quantitative RT-PCR. Importantly, the inflammatory responses in the murine ex vivo culture system reflected the in vivo response in the inflamed colonic tissue as assessed by changes in inflammatory gene expression, suggesting that the murine culture system can be used for validation of future IBD therapies.
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| 6. |
- Odin, Elisabeth, 1955, et al.
(författare)
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Expression and clinical significance of methylenetetrahydrofolate reductase in patients with colorectal cancer
- 2006
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Ingår i: Clin Colorectal Cancer. - 1533-0028. ; 5:5, s. 344-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim of the study was to investigate the influence of methylenetetrahydrofolate reductase (MTHFR) gene expression levels and MTHFR polymorphism C677T on the outcome of patients with colorectal cancer (CRC). Furthermore, we wanted to evaluate the interaction between MTHFR and thymidylate synthase (TS) and folylpolyglutamate synthase (FPGS) and to investigate the impact of folate concentration on patients with CRC with different MTHFR genotypes. PATIENTS AND METHODS: The frequency of MTHFR polymorphism C677T was determined (n = 147), and gene expression levels of MTHFR, TS, and FPGS were quantified with real-time polymerase chain reaction (n = 157). Reduced folates in tissue were measured with a binding assay (n = 40). RESULTS: We observed a significantly lower concentration of tetrahydrofolate (THF) in patients with CT or TT genotypes compared with patients having the CC genotype. Twenty-six patients with Dukes A to C tumors who had not been subjected to chemotherapy relapsed. Out of these, 18 had CT or TT genotypes, and only 8 had the CC genotype (P = 0.045). Furthermore, 75 patients did not relapse, and out of these, 35 had CT or TT genotypes, and 40 had the CC genotype. The relative gene expression level of MTHFR in patients subgrouped by CC and CT or TT genotypes was significantly lower in carcinomas compared with adjacent mucosa (P < 0.0001 and P < 0.0001, respectively). A significant difference in MTHFR expression level was also observed according to MTHFR genotype in the tumor but not in adjacent mucosa. The MTHFR gene expression level in mucosa was a prognostic parameter independent of the clinicopathologic factors with regard to survival for patients with MTHFR C677T mutation. CONCLUSION: Our results showed that it is possible to identify patients with CRC with a higher risk for relapse. Furthermore, patients with a mutant genotype in combination with low MTHFR expression have a poor clinical outcome.
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| 7. |
- Solberg, Anna, 1961, et al.
(författare)
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Progress of tissue injury in appendicitis involves the serine proteases uPA and PAI-1.
- 2009
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Ingår i: Scandinavian journal of gastroenterology. - : Informa UK Limited. - 1502-7708 .- 0036-5521. ; 44:5, s. 579-84
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Serine proteases and the matrix metalloproteinases (MMPs) are key factors in the proteolytic cascade and participate in extracellular matrix (ECM) degradation. Fibrinolytic activators and inhibitors may have an effect on inflammatory cells, thereby modulating the inflammatory response. It is reasonable to assume that they may be implicated in the tissue injury in acute appendicitis that subsequently leads to appendix perforation. The purpose of this study was to investigate the expression and distribution of urokinase-type plasminogen activator (uPA) and plasminogen-activator inhibitor type 1 (PAI-1) in appendicitis. MATERIAL AND METHODS: Expression of uPA and expression of PAI-1 were measured in tissue specimens from patients with appendicitis (n=30) and in control specimens (n=9), using the quantitative ELISA technique. Distribution of enzymes was studied with immunohistochemistry. The uPA and PAI-1 levels in the subgroups of appendicitis and controls were compared. RESULTS: The overall expressions of uPA and PAI-1 were greater in appendicitis than in control specimens (p <0.001 and p<0.0001, respectively). Expressions of uPA and PAI-1 in phlegmonous (n=15), gangrenous (n=6) and perforated appendicitis (n=9) were all higher than those in controls (n=9), (p<0.01). Moreover, the PAI-1 level was elevated in perforated appendicitis compared with phlegmonous appendicitis (p<0.01). uPA staining was observed in connection with vascular endothelial cells and the serosa stained intensely in specimens from perforated appendicitis. CONCLUSIONS: The expression of uPA and especially the over-expression of PAI-1 seem to correlate to the progression of local inflammatory response in acute appendicitis.
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| 8. |
- Wettergren, Yvonne, 1957, et al.
(författare)
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Low expression of reduced folate carrier-1 and folylpolyglutamate synthase correlates with lack of a deleted in colorectal carcinoma mRNA splice variant in normal-appearing mucosa of colorectal carcinoma patients
- 2005
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Ingår i: Cancer Detect Prev. - : Elsevier BV. - 0361-090X .- 1525-1500. ; 29:4, s. 348-55
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cellular folate deficiency leads to DNA strand breaks, mutations, and aberrant methylation and might be a risk factor for colorectal cancer (CRC). The putative tumor suppressor gene deleted in colorectal carcinoma (DCC) is one of several genes the expression of which seems to be affected by the folate concentration at the tissue level. Decreased expression of DCC may be caused by LOH or hypermethylation, i.e. by events that might be linked to folate deficiency. The purpose of this study was to analyze if the folate level and the gene expression levels of reduced folate carrier (RFC-1) and folylpolyglutamate synthase (FPGS) had impact on the expression of DCC splice variants. METHODS: Quantification of RFC-1 and FPGS expression in mucosa of 53 CRC patients was performed using real-time PCR whereas DCC splicing variants were detected by automated capillary gel electrophoresis. Total reduced folate concentration was measured with the FdUMP-binding assay (n = 22). RESULTS: Significantly higher expression levels of RFC-1 (p = 0.026) and FPGS (p = 0.05) were found in mucosa expressing the splice variant DCC342 compared to mucosa that did not. Furthermore, multivariate analysis showed that RFC-1 and FPGS (r = 0.49, p = 0.01) as well as folate and RFC-1 (r = 0.56, p = 0.023) were correlated only in mucosa expressing DCC342. CONCLUSIONS: In conclusion, the present study points to a potential influence of folates in regulating DCC expression at multiple levels involving post-transcriptional pathways. The results may provide a basis for a detailed investigation of molecular mechanisms involved in folate regulation of DCC expression.
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| 9. |
- Willén, Roger, 1939, et al.
(författare)
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Prophylactic surgery for patients with longstanding ulcerative colitis. Which option? Histopathological and clinical implications.
- 2007
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Ingår i: Upsala journal of medical sciences. - 2000-1967 .- 0300-9734. ; 112:1, s. 49-60
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Tidskriftsartikel (refereegranskat)abstract
- Patients with longstanding chronic ulcerative proctocolitis are at risk to develop colorectal cancer Conflicting views as regards surveillance, the indications for surgery and type of preventive procedure exist. For permanent prevention of cancer development complete removal of all potential malignant colorectal mucosa has to be done. Panprocto-colectomy with a conventional ileostomy or continent ileostomy removing all colorectal mucosa should therefore eliminate further risks of colorectal cancer. Colectomy and ileorectal anastomosis is a controversial issue. While many surgeons today are reluctant to use the technique, emphasising the persistent cancer risk, others consider the operation a viable alternative when used on a selective basis. The long-term risk of cancer in the rectal stump is the main strong argument . In restorative proctocolectomy, i.e. proctocolectomy with construction of an ileopouch anal anastomosis residual rectal mucosa is left behind irrespective of technique used and is therefore at risk for cancer development. Quite a few cancers have been reported to occur in these patients but controversy exists as regards the origin of these tumours but the risk for cancer development is very low. Biopsies from ileal pouches demonstrate various histopathological changes from nearly normal mucosa, to inflammation and atrophy, inflammatory cell changes, dysplasia as well as development of carcinoma. Grading of type and atypia is a challenge to reproduce and requires the participation of experienced gastrointestinal histopathologists.
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