| 1. |
- Anand, S, et al.
(författare)
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Divergence of Hoxc8 early enhancer parallels diverged axial morphologies between mammals and fishes
- 2003
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Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 100:26, s. 15666-15669
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Tidskriftsartikel (refereegranskat)abstract
- There is considerable interest in understanding how cis-regulatory modifications drive morphological changes across species. Because developmental regulatory genes, including Hox genes, are remarkably conserved, their noncoding regulatory regions are likely sources for variations. Modifications of Hox cis-regulatory elements have potential to alter Hox gene expression and, hence, axial morphologies. In vertebrates, differences in the axial levels of Hox gene expression correlate with differences in the number and relative position of thoracic vertebrae. Variation in cis-regulatory elements of Hox genes can be identified by comparative sequence and reporter gene analyses in transgenic mouse embryos. Using these approaches, we show a remarkable divergence of the Hoxc8 early enhancers between mammals and fishes representing diverse axial morphologies. Extensive restructuring of the Hoxc8 early enhancer including nucleotide substitutions, inversion, and divergence result in distinct patterns of reporter gene expression along the embryonic axis. Our results provide an evolutionary perspective on how the enhancer elements are engineered and support the hypothesis that remodeling of Hox regulatory elements in different species has played a significant role in generating morphological diversity.
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| 2. |
- Vallbo, Christina, 1964, et al.
(författare)
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The expression of thrombospondin-1 in benign prostatic hyperplasia and prostatic intraepithelial neoplasia is decreased in prostate cancer.
- 2004
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Ingår i: BJU Int. - : Wiley. ; 93:9, s. 1339-1343
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE To evaluate the immunohistochemical expression of thrombospondin (TSP), a potent inhibitor of angiogenesis, in human benign prostatic hyperplasia (BPH) and prostate cancer. MATERIALS AND METHODS The expression of TSP-1, TSP-2 and CD36 receptor was assessed in 73 tissue specimens using immunohistochemistry; specimens were from 32 patients with BPH, seven with prostatic intraepithelial neoplasia (PIN) and 34 with cancer. RESULTS Immunohistochemistry showed that all 39 patients with BPH and PIN had TSP-1-positive glands. In contrast, none of the 34 patients with cancer had positive TSP-1 staining in the cancer tissue. All 73 patients were positive for TSP receptor CD36 and negative for TSP-2. CONCLUSIONS TSP is expressed in BPH, down-regulated in PIN and absent in prostate cancer tissue. This may indicate that TSP is important in prostate cancer progression. Further studies are needed to understand the significance of these findings for the malignant transformation of the prostate gland.
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| 3. |
- Wang, Xin, et al.
(författare)
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Development of high-grade lymphoma in Helicobacter pylori-infected C57BL/6mice
- 2000
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Ingår i: APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. - : Wiley. - 1600-0463. ; 108:7-8, s. 503-508
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori infection is associated with chronic gastritis, peptic ulcer disease, gastric adenocarcinoma and MALT lymphoma. Mice with H. pylori infection develop severe gastritis and atrophic changes in their stomachs after 6 months. We followed H. pylori -infected animals for 13 months to find out whether dysplasia, carcinoma or lymphoma developed. Six-week-old C57BL/6 mice were infected with the CagA-positive and VacA-positive H. pylori mouse-passaged strain 119/95, fed a low antioxidant diet, and kept in microisolated cages. Histopathological changes were examined after 13 months' infection. All H. pylori -inoculated mice (n=5) developed a gastric squamous papilloma with nagging of the lamina muscularis after 13 months. Three out of five animals developed high-grade B-cell lymphoma derived from a MALT lymphoma at the squamous-corpus border with manifestations also in the liver, spleen and kidney. There was a suspicion of local gastric lymphoma in the two remaining mice but with no significant changes in the liver, spleen or kidney. The normal control mice showed no pathological changes in any of these organs. It is concluded that this mouse model with infection by the CagA-positive, vac-toxin-producing H. pylori strain 119/95 is suitable for use in the study of lymphoma development and also development of squamous cell papilloma with proliferative features.
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