| 1. |
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| 2. |
- Bodin, Aase Katarina, 1977, et al.
(författare)
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CELL 11-Cells like cellulose scaffolds
- 2008
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Ingår i: Abstracts of Papers of the American Chemical Society. - 0065-7727. ; 235:APR 6
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Bodin, Aase Katarina, 1977, et al.
(författare)
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Influence of cultivation conditions on mechanical and morphological properties of bacterial cellulose tubes
- 2007
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Ingår i: Biotechnology and Bioengineering. - : Wiley. - 0006-3592 .- 1097-0290. ; 97:2, s. 425-434
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Tidskriftsartikel (refereegranskat)abstract
- Bacterial cellulose (BC) was deposited in tubular form by fermenting Acetobacter xylinum on top of silicone tubes as an oxygenated support and by blowing different concns. of oxygen, i.e., 21% (air), 35%, 50%, and 100%. Mech. properties such as burst pressure and tensile properties were evaluated for all tubes. The burst pressure of the tubes increased with an increase in oxygen ratio and reached a top value of 880 mmHg at 100% oxygen. The Young's modulus was approx. 5 MPa for all tubes, irresp. of the oxygen ratio. The elongation to break decreased from 30% to 10-20% when the oxygen ratio was increased. The morphol. of the tubes was characterized by SEM (SEM). All tubes had an even inner side and a more porous outer side. The cross section indicated that the tubes are composed of layers and that the amt. of layers and the yield of cellulose increased with an increase in oxygen ratio. We propose that an internal vessel wall with high d. is required for the tube to sustain a certain pressure. An increase in wall thickness by an increase in oxygen ratio might explain the increasing burst pressure with increasing oxygen ratio. The fermn. method used renders it possible to produce branched tubes, tubes with unlimited length and inner diams. Endothelial cells (ECs) were grown onto the lumen of the tubes. The cells formed a confluent layer after 7 days. The tubes potential as a vascular graft is currently under investigation in a large animal model at the Center of Vascular Engineering, Sahlgrenska University Hospital, Gothenburg.
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| 4. |
- Bodin, Aase Katarina, 1977, et al.
(författare)
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Modification of nanocellulose with a xyloglucan-RGD conjugate enhances adhesion and proliferation of endothelial cells: implications for tissue engineering.
- 2007
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Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1526-4602 .- 1525-7797. ; 8:12, s. 3697-3704
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes a novel method for introducing the RGD cell adhesion peptide to enhance cell adhesion onto bacterial cellulose (BC). BC and cotton linters as reference were modified with xyloglucan (XG) and xyloglugan bearing a GRGDS pentapeptide. The adsorptions followed Langmuir adsorption behavior, where both XGs probably decorate the cellulose surfaces as a monolayer. The adsorption maximum of the XGs reached around 180 mg/g on BC and only about three times as much on cotton linters. The adsorption was verified with colorimetric methods. The specific surface area of BC measured with XG and XG-GRGDS was about 200 m (2)/g and was almost three times less for cotton linters, 60 m (2)/g. The difference in the amounts of XGs adsorbed might be explained by the swollen network of bacterial cellulose and a more exposed and accessible bulk as compared to cotton linters. The nanocellulose material was modified homogeneously throughout the material, as seen by the z-scan in confocal microscopy. Moreover, the modification in the water phase, in comparison with organic solvents, was clearly advantageous for preserving the morphology, as observed with SEM. The modification slightly increased the wettability, which might explain the decrease in or undetectable adsorption of adhesive protein shown by QCM-D. Initial cell studies showed that adhesion of human endothelial cells is enhanced when the BC hydrogel is modified with XG-GRGDS. QCM-D studies further revealed that the cell enhancement is due to the presence of the RGD epitope on XG and not to a nonspecific adsorption of fibronectin from cell culture medium. Optimization and proliferation studies of human endothelial cells onto bacterial cellulose modified with XG-GRGDS are currently being carried out at the Vascular Engineering Center, Sahlgrenska University Hospital, Gothenburg.
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| 5. |
- Bäckdahl, Henrik, 1977, et al.
(författare)
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Engineering microporosity in bacterial cellulose scaffolds
- 2008
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Ingår i: Journal of tissue engineering and regenerative medicine. - : Hindawi Limited. - 1932-6254 .- 1932-7005. ; 2:6, s. 320-330
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Tidskriftsartikel (refereegranskat)abstract
- The scaffold is an essential component in tissue engineering. A novel method to prepare threedimensional (3D) nanofibril network scaffolds with controlled microporosity has been developed. By placing paraffin wax and starch particles of various sizes in a growing culture of Acetobacter xylinum, bacterial cellulose scaffolds of different morphologies and interconnectivity were prepared. Paraffin particles were incorporated throughout the scaffold, while starch particles were found only in the outermost area of the resulting scaffold. The porogens were successfully removed after culture with bacteria and no residues were detected with electron spectroscopy for chemical analysis (ESCA) or Fourier transform infra-red spectroscopy (FT-IR). Resulting scaffolds were seeded with smooth muscle cells (SMCs) and investigated using histology and organ bath techniques. SMC were selected as the cell type since the main purpose of the resulting scaffolds is for tissue engineered blood vessels. SMCs attached to and proliferated on and partly into the scaffolds. Copyright © 2008 John Wiley & Sons, Ltd.
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| 6. |
- Bäckdahl, Henrik, 1977, et al.
(författare)
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Mechanical properties of bacterial cellulose and interactions with smooth muscle cells
- 2006
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Ingår i: Biomaterials. - : Elsevier BV. - 0142-9612 .- 1878-5905. ; 27:9, s. 2141-2149
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Tidskriftsartikel (refereegranskat)abstract
- Tissue engineered blood vessels (TEBV) represent an attractive approach for overcoming reconstructive problems associated with vascular diseases by providing small calibre vascular grafts. The aim of this study has been to evaluate a novel biomaterial, bacterial cellulose (BC), as a potential scaffold for TEBV. The morphology of the BC pellicle grown in static culture was investigated with SEM. Mechanical properties of BC were measured in Krebs solution and compared with the properties of porcine carotid arteries and ePTFE grafts. Attachment, proliferation and ingrowth of human smooth muscle cells (SMC) on the BC were analysed in vitro. The BC pellicle had an asymmetric structure composed of a fine network of nanofibrils similar to a collagen network. The shape of the stress-strain response of BC is reminiscent of the stress-strain response of the carotid artery, most probably due to the similarity in architecture of the nanofibrill networks. SMC adhered to and proliferated on the BC pellicle; an ingrowth of up to 40 microm was seen after 2 weeks of culture. BC exhibit attractive properties for use in future TEBV.
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| 7. |
- Bäckdahl, Henrik, 1977, et al.
(författare)
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Observations on bacterial cellulose tube formation for application as vascular graft
- 2011
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Ingår i: Materials Science and Engineering C. - : Elsevier BV. - 0928-4931 .- 1873-0191. ; 31:1, s. 14-21
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Tidskriftsartikel (refereegranskat)abstract
- Nanocellulose (bacterial cellulose, BC), such as that produced by Acetobacter xylinum, has shown promising results as a replacement material for small diameter vascular grafts. The surface morphology of the lumen and mechanical properties of such tubes are crucial for their performance. The growth of a BC tube in a vertical fermentation bioreactor using silicone tubing for support and as an oxygen delivery membrane has not been studied in detail previously. Oxygen concentration and the number of bacteria added influence the production of the BC tubes. A dense and smooth luminal surface was formed after 4 days on a 3 mm silicone support. The bacteria were found to be in high concentration close to the silicon support and decreased in number further away. In the region with a high bacteria concentration, dense thin layers of BC were formed since the bacteria moved close together in this region. The presented observations were summarized in a theoretical model of BC tube growth.
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| 8. |
- Delle, M., et al.
(författare)
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Preserved pelvic circulation after stent-graft treatment of complex aortoiliac artery aneurysms: a new approach
- 2005
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Ingår i: Journal of endovascular therapy. - 1526-6028. ; 12:2, s. 189-95
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To describe an endovascular technique that allows stent-graft treatment of aortoiliac aneurysmal disease affecting both common iliac arteries (CIA), with maintenance of pelvic circulation on one side. TECHNIQUE: For patients with aortoiliac aneurysms, both common femoral arteries (CFA) were surgically exposed. One internal iliac artery (IIA) was initially embolized with coils. A bifurcated stent-graft main body was deployed with the proximal end just below the renal arteries. On the ipsilateral side, the stent-graft limb was extended 3 cm beyond the orifice of the embolized IIA into the external iliac artery (EIA) using stent-graft limb extenders. On the contralateral side, the stent-graft limb was deployed so that the distal end was 10 to 15 mm proximal to the patent IIA orifice. Via a left brachial artery access, the IIA was catheterized, and stent-grafts were deployed from the distal end of the contralateral AAA stent-graft limb into the IIA. A femorofemoral crossover graft provided circulation to the leg ipsilateral to the IIA stent-graft, and the EIA on the same side was ligated. The technique can also be modified to treat isolated bilateral CIA aneurysms. CONCLUSIONS: By extending the distal aspect of the stent-graft into an IIA, bilateral CIA aneurysms can be excluded while preserving pelvic circulation on one side.
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| 9. |
- Eriksson, Bengt I., 1946, et al.
(författare)
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Prevention of deep-vein thrombosis and pulmonary embolism after total hip replacement. Comparison of low-molecular-weight heparin and unfractionated heparin.
- 1991
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Ingår i: The Journal of bone and joint surgery. American volume. - 0021-9355. ; 73:4, s. 484-93
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Tidskriftsartikel (refereegranskat)abstract
- In a prospective, randomized, double-blind study, the efficacy and safety of a low-molecular-weight heparin were compared with those of unfractionated sodium heparin (standard heparin) in 136 patients who had elective total hip replacement. The patients received subcutaneous injection of either 5000 international units of low-molecular-weight heparin once daily or 5000 international units of standard heparin three times a day. Treatment with low-molecular-weight heparin began twelve hours before the operation, and treatment with standard heparin began two hours preoperatively; both regimens were continued for ten days. Twelve days postoperatively, bilateral ascending phlebography was performed in 122 patients, sixty-three in the treatment group that received low-molecular-weight heparin and fifty-nine in the treatment group that received standard heparin. Pulmonary scintigraphy was performed in 127 patients. Deep-vein thrombosis was diagnosed in forty-four patients: nineteen (30 per cent) of the sixty-three who received low-molecular-weight heparin and twenty-five (42 per cent) of the fifty-nine who received standard heparin. All but four patients, two from each treatment group, were asymptomatic. The difference in the total rate of thrombosis in the two groups was not significant (p = 0.189). However, thrombosis occurred in the thigh in only six (10 per cent) of the patients who received low-molecular-weight heparin but in eighteen (31 per cent) of those who received standard heparin, a significant difference (p = 0.011). Pulmonary embolism was detected in twenty-seven patients: eight (12.3 per cent) of those who received low-molecular-weight heparin and nineteen (30.6 per cent) of those who received standard heparin. Only three patients had clinical signs of embolism. Pulmonary embolism was significantly more frequent in the group that received standard heparin (p = 0.016). Total loss of blood and the total amount of blood that was transfused were significantly reduced in the patients who received low-molecular-weight heparin compared with those who received standard heparin. Prophylaxis was not discontinued because of hemorrhage in any patient. The efficacy of low-molecular-weight heparin was superior to that of standard heparin in the prevention of femoral thrombosis and pulmonary embolism, although the over-all incidence of deep-vein thrombosis was not statistically different.(ABSTRACT TRUNCATED AT 400 WORDS)
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| 10. |
- Esguerra, Maricris, 1981, et al.
(författare)
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Intravital fluorescent microscopic evaluation of bacterial cellulose as scaffold for vascular grafts.
- 2010
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Ingår i: Journal of biomedical materials research. Part A. - : Wiley. - 1552-4965 .- 1549-3296. ; 93:1, s. 140-9
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Tidskriftsartikel (refereegranskat)abstract
- Although commonly used synthetic vascular grafts perform satisfactorily in large caliber blood vessels, they are prone to thrombosis in small diameter vessels. Therefore, small vessels might benefit from tissue engineered vascular grafts. This study evaluated bacterial cellulose (BC) as a potential biomaterial for biosynthetic blood vessels. We implanted the dorsal skinfold chambers in three groups of Syrian golden hamsters with BC (experimental group), polyglycolic acid, or expanded polytetrafluorethylene (control groups). Following implantation, we used intravital fluorescence microscopy, histology, and immunohistochemistry to analyze the biocompatibility, neovascularization, and incorporation of each material over a time period of 2 weeks. Biocompatibility was good in all groups, as indicated by the absence of leukocyte activation upon implantation. All groups displayed angiogenic response in the host tissue, but that response was highest in the polyglycolic acid group. Histology revealed vascularized granulation tissue surrounding all three biomaterials, with many proliferating cells and a lack of apoptotic cell death 2 weeks after implantation. In conclusion, BC offers good biocompatibility and material incorporation compared with commonly used materials in vascular surgery. Thus, BC represents a promising new biomaterial for tissue engineering of vascular grafts.
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| 11. |
- Fink, Helen, 1978, et al.
(författare)
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An in vitro study of blood compatibility of vascular grafts made of bacterial cellulose in comparison with conventionally-used graft materials
- 2011
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Ingår i: Journal of Biomedical Materials Research - Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 97A:1, s. 52-58
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Tidskriftsartikel (refereegranskat)abstract
- In this study we analyzed the blood compatibility of bacterial cellulose (BC) as a new biosynthetic material for use as a vascular graft. As reference materials we used expanded polytetrafluoroethylene (ePTFE) and poly(ethylene terephthalate) (PET) vascular grafts. These materials are in clinical use today. Tubes with inner diameters of both 4 (not PET) and 6 mm were tested. Heparin-coated PVC tubes (hepPVC) were used as a negative control. Platelet consumption and thrombin-antithrombin complex (TAT) were used as parameters of coagulation and for complement activation, sC3a and sC5b-9 were used. The investigated parameters were measured after 1-h exposure to freshly drawn human blood supplemented with a low dose of heparin in a Chandler loop system. The results showed that BC exhibits no significant difference in platelet consumption, as compared with PET 16 mm), ePTFE and hepPVC. The PET material consumed more platelets than any of the other materials. The TAT generation for 4 mm tubes was not significantly different between BC and the other materials. For 6 mm tubes, however, differences were observed between hepPVC and PET (p < 0.0001); BC and hepPVC (p = 0.0016); ePTFE and PET (p < 0.0001); BC and ePTFE (p = 0.0029); BC and PET (p = 0.0141). Surprisingly, considering the low platelet consumption, the complement activation parameters (sC3a and sC5b-9) were much higher for BC, as compared with the other materials for both 4 and 6 mm tubes.
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| 12. |
- Fink, Helen, 1978, et al.
(författare)
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Bacterial cellulose modified with xyloglucan bearing the adhesion peptide RGD promotes endothelial cell adhesion and metabolism--a promising modification for vascular grafts.
- 2011
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Ingår i: Journal of tissue engineering and regenerative medicine. - : Hindawi Limited. - 1932-7005 .- 1932-6254. ; 5:6, s. 454-63
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Tidskriftsartikel (refereegranskat)abstract
- Today, biomaterials such as polytetrafluorethylene (ePTFE) are used clinically as prosthetic grafts for vascular surgery of large vessels (>5 mm). In small diameter vessels, however, their performance is poor due to early thrombosis. Bacterial-derived cellulose (BC) is a new promising material as a replacement for blood vessels. This material is highly biocompatible in vivo but shows poor cell adhesion. In the native blood vessel, the endothelium creates a smooth non-thrombogenic surface. In order to sustain cell adhesion, BC has to be modified. With a novel xyloglucan (XG) glycoconjugate method, it is possible to introduce the cell adhesion peptide RGD (Arg-Gly-Asp) onto bacterial cellulose. The advantage of the XG-technique is that it is an easy one-step procedure carried out in water and it does not weaken or alter the fiber structure of the hydrogel. In this study, BC was modified with XG and XGRGD to asses primary human vascular endothelial cell adhesion, proliferation, and metabolism as compared with unmodified BC. This XG-RGD-modification significantly increased cell adhesion and the metabolism of seeded primary endothelial cells as compared with unmodified BC whereas the proliferation rate was affected only to some extent. The introduction of an RGD-peptide to the BC surface further resulted in enhanced cell spreading with more pronounced stress fiber formation and mature phenotype. This makes BC together with the XG-method a promising material for synthetic grafts in vascular surgery and cardiovascular research.
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| 13. |
- Fink, Helen, 1978, et al.
(författare)
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Real-time measurements of coagulation on bacterial cellulose and conventional vascular graft materials.
- 2010
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Ingår i: Acta biomaterialia. - : Elsevier BV. - 1878-7568 .- 1742-7061. ; 6:3, s. 1125-30
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Tidskriftsartikel (refereegranskat)abstract
- The search for a functional, small diameter (<5mm) vascular graft has been ongoing for over 30 years, but yet there is no consistently reliable synthetic graft. The primary mechanisms of graft failure are intimal hyperplasia, poor blood flow and surface thrombogenicity. Bacterial cellulose (BC) became therefore a proposed new biosynthetic vascular graft material. Since conventional methods are not suited for coagulation measurements on BC, we have adapted the automated calibrated thrombin generation method for measurements of biomaterial-induced coagulation of BC as compared with clinically used graft materials i.e., expanded poly(tetrafluoroethylene) (ePTFE) and poly(ethyleneterephtalat) (PET). We have also visualized the coagulation propagation at the material surfaces. Thrombin generation experiments revealed dramatic differences between the materials tested. Both ePTFE and BC were found to generate longer lag times and ttpeak values than PET. Most importantly, BC was found to generate the lowest "peak", indicating a slower coagulation process at the surface. These results are also supported by the measurements of factor XIIa generation and analysis of surface coagulation times, which were detected in the following increasing order (mean + or - SD): PET (27 + or - 8 min)
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| 14. |
- Fogelstrand, Per, 1971, et al.
(författare)
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External collar inhibits balloon-induced intimal hyperplasia in rabbits.
- 2002
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Ingår i: Journal of vascular research. - 1018-1172. ; 39:4, s. 361-7
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Tidskriftsartikel (refereegranskat)abstract
- Intimal hyperplasia is a common complication following vascular interventions. To understand the underlying pathophysiology, the focus has mainly been on the intima and media. The adventitia has been less investigated, although adventitial hyperplasia is seen together with intimal hyperplasia. If the adventitial response is an important part of the process, the adventitia might be a target to inhibit intimal hyperplasia. In the present study we investigated whether an external collar attenuating the adventitial thickness could inhibit a balloon-induced intimal hyperplasia. The common carotid artery was injured in rabbits (n = 6) with a 3-french balloon catheter. The mid portion of the injured artery was encircled with a silicone collar (diameter = 2.0 mm). After 14 days the balloon-induced neointima was reduced by 54 +/- 6.3% underneath the collar. The adventitial and medial thickenings were also attenuated (36 +/- 8.7 and 44 +/- 4.3%, respectively). This study demonstrates that intimal hyperplasia following balloon injury can be inhibited with an external collar. This supports the idea of the adventitia as a potential target to inhibit intimal hyperplasia.
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| 15. |
- Helenius, Gisela, 1973, et al.
(författare)
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Effect of shear stress on the expression of coagulation and fibrinolytic factors in both smooth muscle and endothelial cells in a co-culture model.
- 2008
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Ingår i: European surgical research. Europ?ische chirurgische Forschung. Recherches chirurgicales europ?ennes. - : S. Karger AG. - 1421-9921 .- 0014-312X. ; 40:4, s. 325-32
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Tidskriftsartikel (refereegranskat)abstract
- Blood vessels are subjected to forces due to the flow. Endothelial cells (EC) are recipients, cross-talk with smooth muscle cells (SMC), and regulate physiology. It was hypothesized that both EC and SMC respond to shear stress, which alters the expression of factors in coagulation and fibrinolysis. METHODS: A co-culture of human saphenous vein EC (HSVEC) and human saphenous vein SMC (HSVSMC) was exposed to shear, following which the cells were separated. Gene expression of tissue factor, thrombomodulin (TM), plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA) were analyzed with real-time RT-PCR. Protein expression was studied with ELISA. In HSVEC, the expression of PAI-1 (x2.1), tPA (x1.8), uPA (x1.6), tissue factor (x2.5) and TM (x1.9) was upregulated after 4 h of shear compared to controls. After 24 h of shear, expression was still upregulated in tPA (x2.3) and TM (x1.6). In HSVSMC, change in expression of PAI-1 (x2.1) was present after 4 h and in uPA (x2.1), and TM (x0.4) after 24 h. Both HSVEC and HSVSMC responded to shear, which led to altered expression of coagulation and fibrinolytic factors. This indicates that SMC, and interactions between EC and SMC, are more important in the regulation of vascular wall hemostasis than earlier studies have reported.
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| 16. |
- Helenius, Gisela, 1973, et al.
(författare)
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Expression of fibrinolytic and coagulation factors in cocultured human endothelial and smooth muscle cells
- 2004
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Ingår i: Tissue engineering. - 1076-3279. ; 10:3-4, s. 353-60
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Tidskriftsartikel (refereegranskat)abstract
- Interactions between endothelial cells and smooth muscle cells are interesting from a tissue-engineering point of view. We have developed a coculture system that allows direct contact between these two cell types. The fibrinolytic factors PAI-1, tPA, and uPA and the coagulation factor TF, were studied at the gene level by RT-PCR and at the protein level by ELISA. Significant changes of all studied factors were seen at the gene level in cocultured endothelial cells. tPA and TF were upregulated 4- and 7-fold, respectively, and PAI-1 and uPA were downregulated 4- and 1.5-fold, respectively, compared with single-cultured controls. In cocultured smooth muscle cells alterations of PAI-1 and TF were significant, with a 1.5-fold upregulation of PAI-1 and a 2.5-fold downregulation of TF. Results at the protein level mirrored the gene expression results. These findings indicate that cocultured endothelial cells are rendered both hypercoagulative and hyperfibrinolytic.
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| 17. |
- Helenius, Gisela, 1973, et al.
(författare)
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In vivo biocompatibility of bacterial cellulose
- 2006
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Ingår i: Journal of biomedical materials research. - : Wiley. - 1549-3296 .- 1552-4965. ; 76:2, s. 431-8
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Tidskriftsartikel (refereegranskat)abstract
- The biocompatibility of a scaffold for tissue engineered constructs is essential for the outcome. Bacterial cellulose (BC) consists of completely pure cellulose nanofibrils synthesized by Acetobacter xylinum. BC has high mechanical strength and can be shaped into three-dimensional structures. Cellulose-based materials induce negligible foreign body and inflammatory responses and are considered as biocompatible. The in vivo biocompatibility of BC has never been evaluated systematically. Thus, in the development of tissue engineered constructs with a BC scaffold, it is necessary to evaluate the in vivo biocompatibility. BC was implanted subcutaneously in rats for 1, 4, and 12 weeks. The implants were evaluated in aspects of chronic inflammation, foreign body responses, cell ingrowth, and angiogenesis, using histology, immunohistochemistry, and electron microscopy. There were no macroscopic signs of inflammation around the implants. There were no microscopic signs of inflammation either (i.e., a high number of small cells around the implants or the blood vessels). No fibrotic capsule or giant cells were present. Fibroblasts infiltrated BC, which was well integrated into the host tissue, and did not elicit any chronic inflammatory reactions. The biocompatibility of BC is good and the material has potential to be used as a scaffold in tissue engineering.
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| 18. |
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| 19. |
- Heydarkhan-Hagvall, Sepideh, 1969, et al.
(författare)
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DNA microarray study on gene expression profiles in co-cultured endothelial and smooth muscle cells in response to 4- and 24-h shear stress
- 2006
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Ingår i: Molecular and cellular biochemistry. - : Springer Science and Business Media LLC. - 0300-8177 .- 1573-4919. ; 281:1-2, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- Shear stress, a major hemodynamic force acting on the vessel wall, plays an important role in physiological processes such as cell growth, differentiation, remodelling, metabolism, morphology, and gene expression. We investigated the effect of shear stress on gene expression profiles in co-cultured vascular endothelial cells (ECs) and smooth muscle cells (SMCs). Human aortic ECs were cultured as a confluent monolayer on top of confluent human aortic SMCs, and the EC side of the co-culture was exposed to a laminar shear stress of 12 dyn/cm(2) for 4 or 24 h. After shearing, the ECs and SMCs were separated and RNA was extracted from the cells. The RNA samples were labelled and hybridized with cDNA array slides that contained 8694 genes. Statistical analysis showed that shear stress caused the differential expression (p < or = 0.05) of a total of 1151 genes in ECs and SMCs. In the co-cultured ECs, shear stress caused the up-regulation of 403 genes and down-regulation of 470. In the co-cultured SMCs, shear stress caused the up-regulation of 152 genes and down-regulation of 126 genes. These results provide new information on the gene expression profile and its potential functional consequences in co-cultured ECs and SMCs exposed to a physiological level of laminar shear stress. Although the effects of shear stress on gene expression in monocultured and co-cultured EC are generally similar, the response of some genes to shear stress is opposite between these two types of culture (e.g., ICAM-1 is up-regulated in monoculture and down-regulated in co-culture), which strongly indicates that EC-SMC interactions affect EC responses to shear stress.
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| 20. |
- Heydarkhan-Hagvall, Sepideh, 1969, et al.
(författare)
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Production of extracellular matrix components in tissue-engineered blood vessels
- 2006
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Ingår i: Tissue engineering. - : Mary Ann Liebert Inc. - 1076-3279 .- 1557-8690. ; 12:4, s. 831-42
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Tidskriftsartikel (refereegranskat)abstract
- Morphology and compliance of tissue-engineered blood vessels (TEBV) are dependent on the culture period and production of extracellular matrix (ECM) components in order to increase the strength of the developing tissue. The aim of the present study was to evaluate the potential of TEBVs to produce an ECM similar to native arteries and veins. Human smooth muscle cells (SMC) were seeded onto the poly(glycolic acid) (PGA) scaffold and placed in bioreactors filled with DMEM supplemented with growth factors. After 6 weeks, the vessels were harvested from the bioreactors and seeded with human endothelial cells at the lumen for another 3 days. Then, the TEBVs were harvested for RNA and protein isolation for further RT-PCR and Western blot. TEBVs had a similar macroscopic appearance to that of native vessels with no visible evidence of the original PGA. Histological and immunohistochemical analyses indicated the presence of high cell density and development of a highly organized structure of ECM. After 6 weeks of culture, there were significantly lower gene expression of SMC-specific markers, such as alpha-actin, caldesmon, and vimentin, and proteoglycans, such as biglycan, decorin, and versican, and other ECM components, such as collagen I and elastin, in TEBVs, with and without pulsatile conditions, compared to that of native arteries. Gene expression of fibronectin was significantly lower in TEBVs grown during pulsatile conditions compared to that of native arteries. No difference was observed in TEBVs grown during non-pulsatile conditions. The presence of alpha-actin, collagen I, decorin, and fibronectin at protein level was demonstrated in TEBVs with and without pulsatile conditions after 6 weeks and in native veins and arteries as well. How this deviation translates into mechanical properties remains to be explored.
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| 21. |
- Ivarsson, Marie-Louise, 1956, et al.
(författare)
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Characterization and fibrinolytic properties of mesothelial cells isolated from peritoneal lavage.
- 1998
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Ingår i: Scandinavian journal of clinical and laboratory investigation. - 0036-5513. ; 58:3, s. 195-203
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Tidskriftsartikel (refereegranskat)abstract
- Human peritoneal mesothelial cells were harvested from patients undergoing open or laparoscopic surgery for non-septic conditions using three different approaches: (1) from a peritoneal biopsy, (2) from peritoneal fluid, and (3) from lavage fluid collected from peritoneal cavity. When these different methods were compared, cells derived from peritoneal fluid or lavage were more likely to result in established cultures than those obtained from biopsies. The cells displayed morphological, immunohistochemical and ultrastructural characteristics of mesothelial cells. The cultured mesothelial cells produced tissue type plasminogen activator (t-PA), urokinase plasminogen activator (uPA), and plasminogen activator inhibitor type-1 and type-2 (PAI-1 and PAI-2) during unstimulated conditions. Treatment with the proinflammatory mediators LPS and TNF-alpha resulted in an overall decreased fibrinolytic capacity with a decrease in the release of t-PA and an increase in plasminogen activator inhibitors PAI-1 and PAI-2. TNF-alpha had a more profound effect than LPS, especially on the release of t-PA. This may be an important mechanism by which inflammatory mediators disrupt the fibrin degradation. In conclusion, peritoneal lavage is a convenient and reproducible source of mesothelial cells for culture.
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| 22. |
- Jeppsson, B, et al.
(författare)
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Kirurgi.
- 2010
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Bok (övrigt vetenskapligt/konstnärligt)
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| 23. |
- Jeppsson, B, et al.
(författare)
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Kirurgi.
- 2005
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Bok (övrigt vetenskapligt/konstnärligt)
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| 24. |
- Jern, Christina, 1962, et al.
(författare)
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Changes of plasma coagulation and fibrinolysis in response to mental stress.
- 1989
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Ingår i: Thrombosis and haemostasis. - 0340-6245. ; 62:2, s. 767-71
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Tidskriftsartikel (refereegranskat)abstract
- To study the effects of standardized mental stress (arithmetic and the Stroop color word test) on plasma coagulation and fibrinolysis, blood samples were obtained before, during, and after 20 minutes of mental stress from 10 healthy, non-smoking young males aged 22 to 30 years. Reactions were compared with those observed during physical exercise and infusion of adrenaline. Both von Willebrand factor antigen and factor VIII coagulant activity increased significantly in response to mental stress (95 +/- 28 vs 123 +/- 56%; p less than 0.05 and 125 +/- 54 vs 217 +/- 170%; p less than 0.05, respectively). There was also a significant increase of factor VII coagulant activity (86 +/- 31 vs 108 +/- 51%; p less than 0.05). Furthermore, mental stress caused an activation of the fibrinolytic system with an elevation of tissue plasminogen activator activity and tissue plasminogen activator antigen (0.80 +/- 0.48 vs 1.23 +/- 0.96 IU/ml; p = 0.076 and 4.38 +/- 1.87 vs 5.78 +/- 2.58 IU/ml; p less than 0.01). Fibrinogen concentration increased during stress (1.95 +/- 0.29 vs 2.11 +/- 0.27 g/l; p less than 0.05). Similar but more pronounced responses were observed during exercise and adrenaline infusion. Parallel to the increases in coagulation and fibrinolytic factors there were significant increases in heart rate, and systolic and diastolic blood pressure. It is concluded that mental stress has significant effects on plasma coagulation and fibrinolysis, and that it could thus affect important risk factors for cardiovascular disease.
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| 25. |
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| 26. |
- Lönn, Lars, 1956, et al.
(författare)
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Prospective randomized study comparing ultrasound-guided thrombin injection to compression in the treatment of femoral pseudoaneurysms
- 2004
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Ingår i: J Endovasc Ther. - 1526-6028. ; 11:5, s. 570-6
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To compare in a randomized prospective study the treatment of femoral pseudoaneurysms with ultrasound-guided thrombin injection versus ultrasound-guided compression. METHODS: Thirty consecutive patients (22 men; mean age 67+/-8 years, range 53-82) with iatrogenic femoral pseudoaneurysms were randomized to treatment with either ultrasound-guided compression (n=15) or injection of bovine thrombin (n=15). The primary outcome measure was thrombosis of the pseudoaneurysm within 24 hours. Secondary outcome measures were complications and hospitalization time (LOS). RESULTS: Thrombosis within 24 hours was achieved in 15 (100%) patients given thrombin versus 2 (13%) in the compression group (p<0.001). Of 13 pseudoaneurysms failing the initial compression treatment, 7 were retreated, 4 successfully. Thus, only 6 (40%) lesions were thrombosed within 48 hours after 1 or 2 compression sessions. The other 9 cases were successfully treated with thrombin injection. LOS was 2.8+/-1.5 days and 3.5+/-2.4 days in the thrombin and compression groups, respectively (p>0.05). No complications were noted in either group. CONCLUSIONS: Ultrasound-guided thrombin injection induces a fast, effective, and safe thrombosis of postcatheterization pseudoaneurysms. The technique is clearly superior to compression treatment and is recommended as the therapy of choice.
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| 27. |
- Lönn, Lars, 1956, et al.
(författare)
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Should blunt arterial trauma to the extremities be treated with endovascular techniques?
- 2005
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Ingår i: The Journal of trauma. - 0022-5282. ; 59:5, s. 1224-7
-
Tidskriftsartikel (refereegranskat)abstract
- Endovascular techniques are making progress in most aspects of vascular disease. Penetrating or blunt trauma to large arteries can in many cases be managed elegantly with endovascular techniques. However when it comes to arterial trauma of the extremities things are more complicated. There are no reports hitherto in the literature on endovascular treatment of blunt injuries to the arteries of the extremities. In the present report we describe two cases of blunt trauma to the brachial artery treated with balloon angioplasty (PTA) to fixate the dissected intima to the vessel wall. The "glueing" was effective in giving a long lasting patency.We anticipate that there may be a role, though limited, for using PTA as a means of "glueing" the intima. More advanced techniques such as insertion of stents or stent-grafts in traumatized extremity arteries would rarely be indicated.
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| 28. |
- Malm, Carl Johan, et al.
(författare)
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Small calibre biosynthetic bacterial cellulose blood vessels: 13-months patency in a sheep model.
- 2012
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Ingår i: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1651-2006 .- 1401-7431. ; 46:1, s. 57-62
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract Objectives. Many patients in need of bypass surgery lack graft material and current synthetic alternatives have poor performance. A 4 mm vascular graft composed of bacterial cellulose (BC) was developed and tested in pilot study in a large animal model. Design. BC is a biopolymer made by the bacteria acetobacter xylinum. BC grafts (n = 16) with 4 cm length and 4 mm internal diameter were implanted bilaterally in the carotid arteries of eight sheep. No long-term antithrombotic therapy was administered. Patency was assessed with ultrasound. Histology, immunohistochemistry, and electron microscopy were performed after explantation. Results. Fifty percent of the grafts occluded within two weeks. One animal died with patent grafts after 14 days. In the three remaining animals 5/6 grafts were patent after nine months. Two animals were followed 13 months after implantation with 3/4 grafts patent at explantation. All patent grafts had confluent endothelial-like cells. Conclusions. Biosynthetic small calibre vascular grafts made from BC can be patent for up to 13 months in sheep carotid arteries. BC is a potential material for small calibre grafts but patency in animal models needs to be improved before clinical studies can be planned.
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| 29. |
- Risberg, Bo, 1941, et al.
(författare)
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Management of aneurysm sac hygroma
- 2004
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Ingår i: Journal of endovascular therapy. - : International Society of Endovascular Specialists. - 1526-6028 .- 1545-1550. ; 11:2, s. 191-5
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To document the management strategies and outcome of patients diagnosed with sac hygroma following open or endovascular abdominal aortic aneurysm (AAA) repair. METHODS: Seven men (median 68 years, range 43-79) with previous open (n=3) or endovascular (n=4) AAA repairs and increasing aneurysm diameters documented on spiral computed tomography (CT) were diagnosed with sac hygroma based on the lack of a demonstrable endoleak on CT imaging; the presence of a gelatinous, clear fluid in the sac; and a nonpulsatile sac pressure that was about one third of the systemic blood pressure. The patients were followed at regular intervals with spiral CT and percutaneous CT-guided translumbar intrasac pressure measurements. Surgical interventions were performed for sac diameter increase >5 mm or expansion-related pain. Blood samples and fluid aspirated from the sac were analyzed to detect activation of the coagulation and fibrinolytic systems. RESULTS: Over a median 21.5-month follow-up, open fenestration with resection of the aneurysm wall or open tight wrapping of the wall around the graft in 4 patients did not prevent hygroma reoccurrence, nor did repeated punctures with aspiration of fluid in the other 3 patients. Aneurysm diameters remained unchanged during the observation period. CONCLUSIONS: Only symptomatic hygromas need be treated, but the treatment of choice remains to be established, since puncture, fenestration, or resection of the sac do not seem to be adequate.
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| 30. |
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| 31. |
- Risberg, Bo, 1941, et al.
(författare)
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[Thoracic and abdominal aorta aneurysms demand an experienced team work] : Aneurysm i bröst- och bukaorta kräver vältrimmat lagarbete.
- 2004
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Ingår i: Läkartidningen. - 0023-7205. ; 101:19
-
Tidskriftsartikel (refereegranskat)abstract
- Patients with combined aneurysms in the thoracic and abdominal aorta need to be treated at experienced centres. These complicated aneurysms are today treated with various combinations of open and/or endovascular techniques. The complexity of the interventions is associated with high morbidity and mortality. By forming a structured organisation for care of these patients a better outcome can be expected. In this article we present the approach taken in Göteborg to meet these challenges.
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| 32. |
- Rydholm, H E, 1958, et al.
(författare)
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Thrombin signal transduction of the fibrinolytic system in human adult venous endothelium in vitro.
- 1998
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Ingår i: Scandinavian journal of clinical and laboratory investigation. - 0036-5513. ; 58:4, s. 347-52
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Tidskriftsartikel (refereegranskat)abstract
- Thrombin can regulate the-fibrinolytic system by increasing the endothelial production of both tissue plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1). The thrombin receptor transducts signals through the GTP-binding protein system, the classical pathway being the Galpha q-protein. The purpose of the present study was to examine the roles of Galpha i-protein and tyrosine kinases in the thrombin signal transduction of t-PA and PAI-1 production from human adult vein endothelial cells (HAVEC). t-PA and PAI-1 antigen were analysed in conditioned medium from cultured HAVEC after 16 h incubation. Data are expressed as percentages of basal release (100%), means +/- 95% confidence intervals. Thrombin increased t-PA and PAI-1 production (234 +/- 42% and 211 +/- 42%, respectively). Pertussis toxin (PTX) (inhibiting Galpha i-pathway) reduced basal PAI-1 (66 +/- 8%), but had only a weak influence on basal t-PA production. Pertussis toxin and genistein (inhibiting tyrosine kinase) significantly reduced the thrombin induction of both t-PA and PAI-1 (PTX: 142 +/- 23% and 146 +/- 19%, respectively, genistein: 156 +/- 42% and 76 +/- 24%, respectively). The present study demonstrated that thrombin can increase the production of t-PA and PAI-1 by transducting signals through the Galpha i and tyrosine kinase pathway, in addition to the Galpha q/protein kinase C pathway as has been found previously.
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| 33. |
- Tjärnström, Johan, 1957, et al.
(författare)
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Effects of hyperbaric oxygen on expression of fibrinolytic factors of human endothelium in a simulated ischaemia/reperfusion situation.
- 2001
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Ingår i: Scandinavian journal of clinical and laboratory investigation. - 0036-5513. ; 61:7, s. 539-45
-
Tidskriftsartikel (refereegranskat)abstract
- Treatment with hyperbaric oxygen (HBO2) is controversial when treating disorders other than decompression sickness. Still, HBO2 is a treatment modality that has gained recognition in certain situations of ischaemia reperfusion. However, not much is known about its effect on the endothelial cells. Based on earlier studies, the hypothesis was that HBO2 treatment stimulates the release of fibrinolytic factors. The aim of the study was to investigate the effect of HBO2 treatment on cultured endothelial cells in a simulated ischaemia-reperfusion model.
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| 34. |
- Volkmann, E, et al.
(författare)
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Effect of varicose vein surgery on venous reflux scoring and plethysmographic assessment of venous function.
- 2008
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Ingår i: European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery. - : Elsevier BV. - 1532-2165. ; 36:6, s. 731-7
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Colour duplex ultrasonography (CDU) is widely recommended before varicose vein surgery, combined with quantification of venous reflux by plethysmography where required. This study assessed venous haemodynamics before and after varicose vein surgery by venous outflow plethysmography (VOP), venous reflux plethysmography (VRP) and by adoption of a modified segmental venous reflux score (VRS). The effect of wearing one or two class I medical compression stockings was also assessed. The aim of the study was to identify parameters which reflect the outcome of treatment using medical compression stockings or surgical intervention. METHODS: 24 legs of 21 patients with superficial vein incompetence of clinical grade C(2-4a) (CEAP) were assessed before and a mean of 8 S.D. 4 months after superficial vein surgery. Investigations were CDU, as well as VOP and VRP using mercury in rubber gauges fitted either around the calf or the forefoot. Venous reflux was semi-quantitatively graded by CDU in relation to the actual vein diameter and transformed into a VRS with respect to the number of involved serial vein segments. The venous reflux rates were measured in standing patients after knee bending before and after application of one or two superimposed compression stockings (class I). RESULTS: According to VRP, one compression stocking reduced the maximum venous reflux rates (VR(max)) by about 30% which was comparable with the effect of surgery on VR(max). Two superimposed compression stockings were almost twice as effective and diminished VR(max) pre- and post operatively by around 60%. Varicose surgery reduced the maximum venous outflow rates significantly (pre-op: 166 S.D. 77 ml/min x 100 ml tissue, post op: 120 S.D. 34) and improved VRS (pre-op median 5.0 IQR: 4.5-5.5, post-op median 0.5 IQR: 0-1.0). Surgery had no effect on venous refilling time or venous reflux rates when measured without compression stockings. CONCLUSION: Venous reflux assessed by plethysmography was moderated by the use of compression stockings pre-operatively but did not reflect the outcome of surgical treatment of superficial venous reflux. Increased venous volume and venous outflow were restored to the levels of normal contralateral limbs by surgery. The VRS decreased considerably following surgery, reflecting the effect of surgical treatment on the number of incompetent venous segments. Changes in this parameter did not correlate with any of the plethysmographic measurements.
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| 35. |
- Wadenvik, Hans, 1955, et al.
(författare)
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Splenic platelet kinetics and platelet production after major reconstructive vascular surgery.
- 1988
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Ingår i: Acta medica Scandinavica. - 0001-6101. ; 223:2, s. 147-52
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Tidskriftsartikel (refereegranskat)abstract
- By using 111In-labelled platelets and dynamic gamma camera scintigraphy, platelet production rate and intrasplenic platelet kinetics were determined in 13 patients at 1 and 4 months after aortic reconstructive vascular surgery with implantation of dacron prostheses. A significant decrease in platelet production rate and venous platelet count was recorded over time after surgery. Irrespective of whether the exchangeable splenic platelet pool was estimated from initial recovery of platelet-bound radioactivity or from compartmental analysis, the size of this pool was significantly lower at the first study; a change in intrasplenic platelet transit time accounted for the observed difference. Platelet mean life-span increased over time after surgery but the difference between the duplicate studies was not statistically significant. It can be concluded that there is a reduction of platelet production rate and venous platelet count over time after major reconstructive vascular surgery. The early postoperative elevation in the platelet count is mainly the result of an increased platelet production and to a lesser degree due to redistribution of platelets between the splenic platelet pool and general circulation.
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| 36. |
- Wann-Hansson, Christine, et al.
(författare)
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A comparison of the Nottingham Health Profile and Short Form 36 Health Survey in patients with chronic lower limb ischaemia in a longitudinal perspective
- 2004
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Ingår i: Health and quality of life outcomes. - : Springer Science and Business Media LLC. - 1477-7525. ; 2
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Different generic quality of life instruments such as the Nottingham Health Profile (NHP) and the Short Form 36 Health Survey (SF-36) have revealed conflicting results in patients with chronic lower limb ischaemia in psychometric attributes in short-term evaluations. The aim of this study was to compare the NHP and the SF-36 regarding internal consistency reliability, validity, responsiveness and suitability as outcome measures in patients with lower limb ischaemia in a longitudinal perspective. METHODS: 48 patients with intermittent claudication and 42 with critical ischaemia were included. Assessment was made before and one year after revascularization using comparable domains of the NHP and the SF-36 questionnaires. RESULTS: The SF-36 was less skewed and more homogeneous than the NHP. There was an average convergent validity in three of the five comparable domains one year postoperatively. The SF-36 showed a higher internal consistency except for social functioning one-year postoperatively and was more responsive in detecting changes over time in patients with intermittent claudication. The NHP was more sensitive in discriminating among levels of ischaemia regarding pain and more able to detect changes in the critical ischaemia group. CONCLUSION: Both SF-36 and NHP have acceptable degrees of reliability for group-level comparisons, convergent and construct validity one year postoperatively. Nevertheless, the SF-36 has superior psychometric properties and was more suitable in patients with intermittent claudication. The NHP however, discriminated better among severity of ischaemia and was more responsive in patients with critical ischaemia.
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| 37. |
- Wann-Hansson, Christine, et al.
(författare)
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Health-related quality of life after revascularization for peripheral arterial occlusive disease: long-term follow-up
- 2005
-
Ingår i: Journal of advanced nursing. - : Wiley. - 0309-2402 .- 1365-2648. ; 51:3, s. 227-35
-
Tidskriftsartikel (refereegranskat)abstract
- AIM: This paper reports a study to measure quality of life, before and after revascularization, in patients with intermittent claudication and critical limb ischaemia from a long-term perspective. BACKGROUND: Patients with peripheral arterial occlusive disease have a number of problems which affect their quality of life and a successful revascularization results in immediate improvements in quality of life. However, knowledge of the durability of the improvements is sparse. Therefore, research on the outcomes of treatment and nursing care should investigate the long-term effects on quality of life and daily activities. METHODS: A quasi-experimental longitudinal follow-up study was conducted with 80 patients with intermittent claudication and 62 with critical ischaemia. Assessment with the Nottingham Health Profile was made before revascularization and 6 months, 12 months and up to 4 years afterwards. The data were collected between 1995 and 2000. RESULTS: Quality of life was improved 6 and 12 months after revascularization in patients with intermittent claudication in energy, pain, emotional reactions and physical mobility, while those with critical limb ischaemia also had improvements in pain and sleep. The improvement in pain was particularly evident for both groups and remained significantly improved up to 4 years after revascularization. Patients with critical limb ischaemia, however, deteriorated significantly with regard to physical mobility between 12 months and 4 years. Being a woman and belonging to the critical ischaemia group was significantly associated with high total Nottingham Health Profile score. Thus, patients with intermittent claudication had more durable benefits from revascularization than those with critical limb ischaemia. However, both groups had less pain than at baseline after 4 years. CONCLUSION: The degree to which quality of life was durable over time seems to depend on the severity of the disease and gender. Patients with critical limb ischaemia were older, had more other diseases and a lower quality of life than patients with intermittent claudication, which confirmed that patients with critical limb ischaemia need more ongoing nursing support to maintain independence in daily life a long time after revascularization.
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| 38. |
- Örtenwall, Per, 1951, et al.
(författare)
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Endothelial cell seeding reduces thrombogenicity of Dacron grafts in humans.
- 1990
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Ingår i: Journal of vascular surgery. - 0741-5214. ; 11:3, s. 403-10
-
Tidskriftsartikel (refereegranskat)abstract
- Vascular prostheses in humans do not endothelialize spontaneously. In the present study we explored the feasibility of seeding autologous endothelial cells into prostheses implanted in patients undergoing reconstruction of the infrarenal aorta. In 22 patients one limb of an aortic Dacron bifurcation prosthesis was seeded with autologous endothelial cells harvested from the distal portion of the saphenous vein. The other limb was sham-seeded with culture medium only. The effect of seeding was studied by use of indium 111 radiolabeled platelets and external gamma camera scanning at 1, 4, and 12 months after surgery. No complications ascribable to the seeding procedure were seen. During the first year after surgery a gradual decrease in platelet accumulation occurred over the whole vascular prosthesis. At all time points studied the seeded graft limbs exhibited significantly less deposition of radiolabeled platelets than did control limbs. The observed difference in platelet accumulation on autologous endothelial seeding-treated graft segments merits further investigation of this technique in humans.
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| 39. |
- Örtenwall, Per, 1951, et al.
(författare)
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Reduced platelet deposition on seeded versus unseeded segments of expanded polytetrafluoroethylene grafts: clinical observations after a 6-month follow-up.
- 1989
-
Ingår i: Journal of vascular surgery. - 0741-5214. ; 10:4, s. 374-80
-
Tidskriftsartikel (refereegranskat)abstract
- The concept of autologous endothelial cell seeding has proved successful in animal models with respect to decrease of graft thrombogenicity and increase in patency. In the present study, application of this method in humans was explored. In 23 patients, random halves of expanded polytetrafluoroethylene grafts, used for lower limb arterial reconstructions, were seeded with endothelial cells at a seeding density of 3500 cells/cm2. These cells were derived from the saphenous vein by enzymatic harvesting. The other half was sham seeded with culture medium. Graft thrombogenicity was estimated by measuring platelet deposition on graft surface 1 and 6 months after surgery, with indium 111-labeled platelets and external gamma-camera imaging. Seeded graft segments accumulated significantly (p less than 0.03) fewer platelets at all imaging times. It is concluded that seeding of expanded polytetrafluoroethylene vascular grafts in humans reduces graft surface thrombogenicity. The clinical implications of this remain to be demonstrated.
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| 40. |
- Örtenwall, Per, 1951, et al.
(författare)
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Reduction in deposition of indium 111-labeled platelets after autologous endothelial cell seeding of Dacron aortic bifurcation grafts in humans: a preliminary report.
- 1987
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Ingår i: Journal of vascular surgery. - : Elsevier BV. - 0741-5214. ; 6:1, s. 17-25
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Tidskriftsartikel (refereegranskat)abstract
- Autologous endothelial seeding (AES) of vascular prostheses in dogs increases thrombus-free surface and improves prosthetic prostacyclin production, patency, and the ability to withstand hematogenous challenge with bacteria. No such information is available in human subjects. In the present study one limb of an aortic Dacron bifurcation prosthesis was seeded with autologous endothelial cells (ECs) harvested from the distal portion of the saphenous vein by enzymatic treatment. The deposition of indium 111-labeled platelets on the vascular prostheses was studied 1 and 4 months after operation. In seven of nine patients seeding resulted in decreased accumulation of radiolabeled platelets compared with sham-seeded control limbs (p less than 0.04), when studied 1 month after surgery. A decrease in platelet accumulation occurred over the whole prosthesis between 1 and 4 months, and no significant difference was noted at 4 months between seeded and nonseeded graft limbs. Although the seeding density was very low (440 ECs/cm2), the observed difference in platelet accumulation for AES-treated graft limbs in the early postoperative course merits further investigation of this technique in human beings.
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