| 1. |
- Falk, Kristina, 1972, et al.
(författare)
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Antifibrinolytic proCPU is present in the peritoneal cavity during surgery.
- 2003
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Ingår i: Scandinavian journal of clinical and laboratory investigation. - 0036-5513. ; 63:4, s. 287-96
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Tidskriftsartikel (refereegranskat)abstract
- The fibrinolytic capacity of the peritoneum plays a pivotal role in peritoneal wound healing. During surgery the balance between fibrin deposition and degradation is tilted towards deposition, leading to the formation of adhesions. In blood, carboxypeptidase U (CPU) stabilizes clots by retarding fibrinolysis. The purpose of this study was to investigate whether the more stable zymogen, proCPU, is also present in the peritoneal cavity and, if so, to examine its origin. Levels of proCPU were measured in plasma and serosal peritoneal fluid collected during surgery. Peritoneal biopsies were stained for proCPU. Two-dimensional gel electrophoresis was performed to study the protein composition of the serosal fluid compared to plasma and Western blotting to identify differences in glycosylation of proCPU, indicating possible different cellular origin. Cultured human mesothelial cells were examined for proCPU production under normal conditions and conditions mimicking surgery. We found comparable and correlating levels of proCPU in serosal fluid and plasma. ProCPU was also found where fibrin covered the injured peritoneal surface. A protein composition very similar in serosal fluid and plasma was shown by two-dimensional gel electrophoresis, and the proCPU pattern did not indicate a different origin. No proCPU production was found in cultured mesothelial cells. This is the first study to report on the presence of proCPU in the peritoneal cavity, which seems to be the result of plasma oozing out during the inflammatory reaction to the surgical trauma. This is likely to be important for the balance between fibrin deposition and degradation and thereby in the formation of postoperative adhesions.
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| 2. |
- Falk, Peter, 1962, et al.
(författare)
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Studies of TGF-beta(1-3) in serosal fluid during abdominal surgery and their effect on in vitro human mesothelial cell proliferation.
- 2009
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Ingår i: The Journal of surgical research. - : Elsevier BV. - 1095-8673 .- 0022-4804. ; 154:2, s. 312-6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Increased transforming growth factor-beta (TGF-beta) levels are associated with fibrosis, affected cell proliferation, and postsurgical adhesion development, but the knowledge regarding TGF-beta response to the surgical trauma is limited. This study investigated TGF-beta(1-3) isoforms and fibrinolytical factors in peritoneal serosal fluid during abdominal surgery, together with the in vitro effect of TGF-beta(1-3) on human mesothelial cell proliferation. MATERIALS AND METHODS: Total as well as biologically active TGF-beta(1-3) and fibrinolytic factors: t-PA, uPA, and PAI-1 were measured in serosal fluid and plasma from 23 patients undergoing colorectal cancer surgery. In vitro proliferation of human primary mesothelial cell cultures upon TGF-beta(1-3) stimulation was also investigated. RESULTS: Total TGF-beta1 and TGF-beta2 levels were similar in serosal fluid and plasma while active fractions were increased in serosal fluid. In contrast, total fraction of TGF-beta3 was higher in serosal fluid compared with plasma, while levels of active fractions did not differ. Plasminogen activators (t-PA, uPA) were elevated while the inhibitor (PAI-1) was decreased in serosal fluid compared with plasma. The in vitro mesothelial cell proliferation studies revealed that high TGF-beta(1-3) concentrations decreased cell proliferation, while lower concentrations of TGF-beta1 increased mesothelial cell proliferation. CONCLUSIONS: This human study shows increased active TGF-beta levels in peritoneal serosal fluid, compared with plasma, during abdominal surgery and that TGF-beta1 at physiological concentrations increased human mesothelial cell proliferation in vitro. TGF-beta cytokines may be involved in postsurgical adhesion formation.
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| 3. |
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| 4. |
- Solberg, Anna, 1961, et al.
(författare)
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A local imbalance between MMP and TIMP may have an implication on the severity and course of appendicitis.
- 2008
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Ingår i: International journal of colorectal disease. - : Springer Science and Business Media LLC. - 0179-1958 .- 1432-1262. ; 23:6, s. 611-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Matrix metalloproteinases (MMPs) and the tissue inhibitors of MMPs (TIMPs) have been demonstrated to be involved in inflammatory conditions in the intestine. The purpose of this study was to investigate whether the alterations of the MMP/TIMP balance might reflect the course of the inflammatory process in acute appendicitis and if the expression and localisation of MMPs and TIMP is variable in the various clinical manifestations of appendicitis. MATERIALS AND METHODS: The study comprises 40 patients (26 men and 14 women) having emergency appendectomy and a control group constituting of 10 patients (5 men and 5 women) having a hemicolectomy for other reasons. MMP and TIMP expressions were assessed and compared in tissue specimens from phlegmonous (n = 15), gangrenous (n = 7), perforated appendicitis (n = 11) and controls with noninflamed appendices (n = 10) by means of enzyme-linked immunosorbent assay technique. Localisation of the enzymes was performed by immunohistochemistry. RESULTS: MMP-1 was significantly higher in gangrenous and perforated appendicitis compared with phlegmonous appendicitis and controls (p < 0.05) while MMP-2 was significantly lower in gangrenous appendicitis compared with phlegmonous appendicitis and controls. MMP-2 was also lower in perforated appendicitis when compared with controls (p < 0.01). Elevated expression of MMP-9 was demonstrated in all groups of appendicitis compared with the controls (p < 0.001). CONCLUSIONS: MMP-9 is the most abundantly expressed MMP of those investigated in inflamed appendix. We postulate that a local imbalance between MMP-9 and TIMP-1 may trigger a perforation. These results suggest that MMPs might be useful as biomarkers of appendices prone to perforation.
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| 5. |
- Solberg, Anna, 1961, et al.
(författare)
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Local and systemic expressions of MMP-9, TIMP-1 and PAI-1 in patients undergoing surgery for clinically suspected appendicitis.
- 2012
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Ingår i: European surgical research. Europäische chirurgische Forschung. Recherches chirurgicales européennes. - : S. Karger AG. - 1421-9921. ; 48:2, s. 99-105
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Tidskriftsartikel (refereegranskat)abstract
- To examine, compare and correlate the expressions of matrix metalloproteinase 9 (MMP-9), tissue inhibitor of metalloproteinase 1 (TIMP-1) and plasminogen activator inhibitor type 1 (PAI-1) in appendiceal tissue and pre- and postoperative blood samples in patients undergoing surgery for clinically suspected appendicitis.
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| 6. |
- 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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| 7. |
- Solberg, Anna, 1961, et al.
(författare)
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Tissue Proteolysis in Appendicitis with Perforation
- 2011
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Ingår i: Journal of Surgical Research. - : Elsevier BV. - 0022-4804 .- 1095-8673. ; 169:2, s. 194-201
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Matrix metalloproteinases (MMPs) and serine proteases are able to degrade the extracellular matrix (ECM) and modulate immune responses in the gastrointestinal tract. The purpose of this study was to investigate local proteolysis in perforated appendicitis and its association with the appendix perforation. MATERIALS AND METHODS: Biopsies were taken at the sites of perforation (n = 15) and with a gradually increased distance from it. The expression and distribution of MMP-1, -2, and -9, the tissue inhibitor of metalloproteinases type (TIMP-1), plasminogen activator inhibitor type1 (PAI-1), and urokinase plasminogen activator (uPA) were measured by ELISA. The distribution of MMP-9, TIMP-1, uPA, and PAI-1 in perforated, nonperforated, and uninflamed appendix was investigated by immunohistochemistry with monoclonal antibody technique. RESULTS: MMP-1 expression was highest close to the perforation and was gradually decreased in biopsies in more distal locations (P < 0.01). MMP-9 showed a similar pattern being highest at the sites of perforation (P < 0.05), while MMP-2 expression showed a trend in the opposite direction without statistically significance. The expression of TIMP-1 trended lower at the sites of perforation. PAI-1 was highest at the sites of perforation (P < 0.01) and the uPA expression was similarly elevated close to and at the perforation. CONCLUSIONS: These data indicate a key role of MMP in the pathogenesis of appendix perforation. A local imbalance between MMP-9 and the inhibitor TIMP-1 could potentially contribute to the tissue injury leading to an appendix perforation. The overexpression of PAI-1 at the sites of perforation may also contribute to tissue damage.
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| 8. |
- Ding, Feng, 1970, et al.
(författare)
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Graphitic encapsulation of catalyst particles in carbon nanotube production
- 2006
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-5207 .- 1520-6106. ; 110:15, s. 7666-7670
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Tidskriftsartikel (refereegranskat)abstract
- A new model is proposed for the encapsulation of catalyst metal particles by graphite layers that are obtained, for example, in low-temperature chemical vapor deposition production of carbon nanotubes (CNTs). In this model graphite layers are primarily formed from the dissolved carbon atoms in the metal-carbide particle when the particle cools. This mechanism is in good agreement with molecular dynamics simulations (which show that precipitated carbon atoms preferentially form graphite sheets instead of CNTs at low temperatures) and experimental results (e.g., encapsulated metal particles are found in low-temperature zones and CNTs in high-temperature regions of production apparatus, very small catalyst particles are generally not encapsulated, and the ratio of the number of graphitic layers to the diameter of the catalyst particle is typically 0.25 nm(-1)).
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| 9. |
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| 10. |
- Falk, Lena, 1956
(författare)
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SiAlON Microstructures
- 2008
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Ingår i: J. Ceram. Soc. Japan. ; 116:6, s. 685-687
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Tidskriftsartikel (refereegranskat)
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