| 1. |
- Eriksson, Jesper, et al.
(författare)
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Temporal patterns of organ dysfunction after severe trauma
- 2021
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Ingår i: Critical Care. - : Springer Nature. - 1364-8535 .- 1466-609X. ; 25:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Understanding temporal patterns of organ dysfunction (OD) may aid early recognition of complications after trauma and assist timing and modality of treatment strategies. Our aim was to analyse and characterise temporal patterns of OD in intensive care unit-admitted trauma patients. Methods We used group-based trajectory modelling to identify temporal trajectories of OD after trauma. Modelling was based on the joint development of all six subdomains comprising the sequential organ failure assessment score measured daily during the first two weeks post trauma. Further, the time for trajectories to stabilise and transition to final group assignments were evaluated. Results Six-hundred and sixty patients were included in the final model. Median age was 40 years, and median ISS was 26 (IQR 17-38). We identified five distinct trajectories of OD. Group 1, mild OD (n = 300), median ISS of 20 (IQR 14-27), had an early resolution of OD and a low mortality. Group 2, moderate OD (n = 135), and group 3, severe OD (n = 87), were fairly similar in admission characteristics and initial OD but differed in subsequent OD trajectories, the latter experiencing an extended course and higher mortality. In group 3, 56% of the patients developed sepsis as compared with 19% in group 2. Group 4, extreme OD (n = 40), received most blood transfusions, had the highest proportion of shock at admission and a median ISS of 41 (IQR 29-50). They experienced significant and sustained OD affecting all organ systems and a 28-day mortality of 30%. Group 5, traumatic brain injury with OD (n = 98), had the highest mortality of 35% and the shortest time to death for non-survivors, median 3.5 (IQR 2.4-4.8) days. Groups 1 and 5 reached their final group assignment early, > 80% of the patients within 48 h. In contrast, groups 2 and 3 had a prolonged time to final group assignment. Conclusions We identified five distinct trajectories of OD after severe trauma during the first two weeks post-trauma. Our findings underline the heterogeneous course after trauma and describe some potentially important clinical insights that are suggested by the groupings and temporal trajectories.
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| 2. |
- Jenndahl, L., et al.
(författare)
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Personalized tissue-engineered arteries as vascular graft transplants : A safety study in sheep
- 2022
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Ingår i: Regenerative Therapy. - : Japanese Society of Regenerative Medicine. - 2352-3204. ; 21, s. 331-341
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Tidskriftsartikel (refereegranskat)abstract
- Patients with cardiovascular disease often need replacement or bypass of a diseased blood vessel. With disadvantages of both autologous blood vessels and synthetic grafts, tissue engineering is emerging as a promising alternative of advanced therapy medicinal products for individualized blood vessels. By reconditioning of a decellularized blood vessel with the recipient's own peripheral blood, we have been able to prevent rejection without using immunosuppressants and prime grafts for efficient recellularization in vivo. Recently, decellularized veins reconditioned with autologous peripheral blood were shown to be safe and functional in a porcine in vivo study as a potential alternative for vein grafting. In this study, personalized tissue engineered arteries (P-TEA) were developed using the same methodology and evaluated for safety in a sheep in vivo model of carotid artery transplantation. Five personalized arteries were transplanted to carotid arteries and analyzed for safety and patency as well as with histology after four months in vivo. All grafts were fully patent without any occlusion or stenosis. The tissue was well cellularized with a continuous endothelial cell layer covering the luminal surface, revascularized adventitia with capillaries and no sign of rejection or infection. In summary, the results indicate that P-TEA is safe to use and has potential as clinical grafts.
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| 3. |
- Stenlund, Patrik, et al.
(författare)
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Effect of load on the bone around bone-anchored amputation prostheses
- 2017
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Ingår i: Journal of Orthopaedic Research. - : Wiley. - 0736-0266 .- 1554-527X. ; 35:5, s. 1113-1122
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Tidskriftsartikel (refereegranskat)abstract
- Osseointegrated transfemoral amputation prostheses have proven successful as an alternative method to the conventional socket-type prostheses. The method improves prosthetic use and thus increases the demands imposed on the bone-implant system. The hypothesis of the present study was that the loads applied to the bone-anchored implant system of amputees would result in locations of high stress and strain transfer to the bone tissue and thus contribute to complications such as unfavourable bone remodeling and/or elevated inflammatory response and/or compromised sealing function at the tissue-abutment interface. In the study, site-specific loading measurements were made on amputees and used as input data in finite element analyses to predict the stress and strain distribution in the bone tissue. Furthermore, a tissue sample retrieved from a patient undergoing implant revision was characterized in order to evaluate the long-term tissue response around the abutment. Within the limit of the evaluated bone properties in the present experiments, it is concluded that the loads applied to the implant system may compromise the sealing function between the bone and the abutment, contributing to resorption of the bone in direct contact with the abutment at the most distal end. This was supported by observations in the retrieved clinical sample of bone resorption and the formation of a soft tissue lining along the abutment interface. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1113–1122, 2017.
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| 4. |
- Håkansson, Joakim, 1975, et al.
(författare)
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Changes in ion-channels in the dorsal root ganglion after exposure to autologous nucleus pulposus and TNF. A rat experimental study
- 2024
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Ingår i: Journal of Orthopaedics. - : Reed Elsevier India Pvt. Ltd.. - 0972-978X .- 2589-9082. ; 47, s. 23-27
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: It is known that contact of nucleus pulposus with the dorsal root ganglion may induce changes in nerve conduction and pain behavior. It has also been suggested that the behavioristic changes are caused by changes in voltage-gated ion channels, which in turn have been upregulated by TNF. Such upregulations have previously been shown for NaV 1.8 and NaV 1.9. In this investigation, we expanded the number of studied ion channels after the application of nucleus pulposus or TNF. Methods: Following removal of the left L4-5 fact joint, a disc puncture was performed and the dorsal root ganglion was exposed to nucleus pulposus (n = 5) and TNF (n = 5). Operated rats without disc puncture served as sham (n = 5) and 5 non-operated (naïve) rats were included. After 24 h, the DRGs were harvested and analyzed by quantitative PCR on validated pre-spotted primer plates displaying genes for 90 voltage-gated ion channels. Results: It was evident that the changes in operated animals were separate from the naïve rats. It was also apparent that gene expression changes in rats with nucleus pulposus or TNF application showed similar trends and were also separated from sham-operated animals. Conclusion: The application of nucleus pulposus and TNF onto the DRG in rats induces comparable changes in gene expression of several ion channels. Since the changes induced by TNF and NP are similar, one might also suspect that TNF mediates the NP-induced changes. However, such a mechanism needs further investigation.
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| 5. |
- Håkansson, Joakim, 1975, et al.
(författare)
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Individualized tissue-engineered veins as vascular grafts: A proof of concept study in pig
- 2021
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Ingår i: Journal of Tissue Engineering and Regenerative Medicine. - : Hindawi Limited. - 1932-6254 .- 1932-7005. ; 15:10, s. 818-830
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Tidskriftsartikel (refereegranskat)abstract
- Personalized tissue engineered vascular grafts are a promising advanced therapy medicinal product alternative to autologous or synthetic vascular grafts utilized in blood vessel bypass or replacement surgery. We hypothesized that an individualized tissue engineered vein (P-TEV) would make the body recognize the transplanted blood vessel as autologous, decrease the risk of rejection and thereby avoid lifelong treatment with immune suppressant medication as is standard with allogenic organ transplantation. To individualize blood vessels, we decellularized vena cava from six deceased donor pigs and tested them for cellular removal and histological integrity. A solution with peripheral blood from the recipient pigs was used for individualized reconditioning in a perfusion bioreactor for seven days prior to transplantation. To evaluate safety and functionality of the individualized vascular graft in vivo, we transplanted reconditioned porcine vena cava into six pigs and analyzed histology and patency of the graft at different time points, with three pigs at the final endpoint 4-5 weeks after surgery. Our results showed that the P-TEV was fully patent in all animals, did not induce any occlusion or stenosis formation and we did not find any signs of rejection. The P-TEV showed rapid recellularization in vivo with the luminal surface covered with endothelial cells. In summary, the results indicate that P-TEV is functional and have potential for use as clinical transplant grafts.
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| 6. |
- Kuna, Vijay Kumar, 1987, et al.
(författare)
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Significantly accelerated wound healing of full-thickness skin using a novel composite gel of porcine acellular dermal matrix and human peripheral blood cells
- 2017
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Ingår i: Cell Transplantation. - : Cognizant Communication Corporation. - 0963-6897 .- 1555-3892. ; 26:2, s. 293-307
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we report the fabrication of a novel composite gel from decellularized gal-gal-knockout porcine skin and human peripheral blood mononuclear cells (hPBMC) for full-thickness skin wound healing. Decellularized skin extracellular matrix (ECM) powder was prepared via chemical treatment, freeze-drying and homogenization. The powder was mixed with culture medium containing hyaluronic acid to generate a pig skin gel (PSG). The effect of the gel in regeneration of full-thickness wound was studied in nude mice. We found significantly accelerated wound closure already on day 15 in animals treated with PSG only or PSG+hPBMC as compared to untreated and hyaluronic acid treated controls (p<0.05). Addition of the hPBMC to the gel resulted in marked increase of host blood vessels as well as the presence of human blood vessels. At day 25, histologically, the wounds in animals treated with PSG only or PSG+hPBMC were completely closed as compared to controls. Thus, the gel facilitated generation of new skin with well arranged epidermal cells and restored bilayer structure of the epidermis and dermis. These results suggest that porcine skin ECM gel together with human cells may be a novel and promising biomaterial for medical applications especially for patients with acute and chronic skin wounds.
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| 7. |
- 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
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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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| 8. |
- Methe, Ketaki, et al.
(författare)
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An alternative approach to decellularize whole porcine heart
- 2014
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Ingår i: BioResearch Open Access. - : Mary Ann Liebert Inc. - 2164-7844 .- 2164-7860. ; 3:6, s. 327-338
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Tidskriftsartikel (refereegranskat)abstract
- Scaffold characteristics are decisive for repopulating the acellular tissue with cells. A method to produce such a scaffold from intact organ requires a customized decellularization protocol. Here, we have decellularized whole, intact porcine hearts by serial perfusion and agitation of hypotonic solution, an ionic detergent (4% sodium deoxycholate), and a nonionic detergent (1% Triton X-100). The resultant matrix was characterized for its degree of decellularization, morphological and functional integrity. The protocol used resulted in extensive decellularization of the cardiac tissue, but the cytoskeletal elements (contractile apparatus) of cardiomyocytes remained largely unaffected by the procedure although their membranous organelles were completely absent. Further, several residual angiogenic growth factors were found to be present in the decellularized tissue.
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| 9. |
- Olausson, Michael, 1956, et al.
(författare)
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In vivo application of tissue-engineered veins using autologous peripheral whole blood: A proof of concept study
- 2014
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Ingår i: EBioMedicine. - : Elsevier BV. - 2352-3964. ; 1:1, s. 72-79
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Tidskriftsartikel (refereegranskat)abstract
- Vascular diseases are increasing health problems affecting >25 million individuals in westernized societies. Such patients could benefit fromtransplantation of tissue-engineered vascular grafts using autologous cells. One challenge that has limited this development is the need for cell isolation, and risks associated with ex vivo expanded stem cells. Herewe demonstrate a novel approach to generate transplantable vascular grafts using decellularized allogeneic vascular scaffolds, repopulatedwith peripheralwhole blood (PWB) in vitro in a bioreactor. Circulating, VEGFR-2+/CD45+ and a smaller fraction of VEGFR-2+/CD14+ cells contributed to repopulation of the graft. SEMmicrographs showed flat cells on the luminal surface of the grafts consistentwith endothelial cells. For clinical validation, two autologous PWBtissue-engineered vein conduits were prepared and successfully used for bypass procedures in two pediatric patients. These results provide a proof of principle for the generation of transplantable vascular grafts using a simple autologous blood sample, making it clinically feasible globally.
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| 10. |
- Patil, Pradeep B, 1982, et al.
(författare)
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Recellularization of acellular human small intestine using bone marrow stem cells.
- 2013
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Ingår i: Stem cells translational medicine. - : Oxford University Press (OUP). - 2157-6564 .- 2157-6580. ; 2:4, s. 307-15
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Tidskriftsartikel (refereegranskat)abstract
- We aimed to produce an acellular human tissue scaffold with a view to test the possibility of recellularization with bone marrow stem cells to produce a tissue-engineered small intestine (TESI). Human small-bowel specimens (n = 5) were obtained from cadaveric organ donors and treated sequentially with 6% dimethyl sulfoxide in hypotonic buffer, 1% Triton X-100, and DNase. Each small intestine (SI) piece (6 cm) was recellularized with EPCAM+ and CD133+ allogeneic bone marrow stem cells. Histological and molecular analysis demonstrated that after decellularization, all cellular components and nuclear material were removed. Our analysis also showed that the decellularized human SI tissue retained its histoarchitecture with intact villi and major structural proteins. Protein films of common extracellular matrix constituents (collagen I, laminin, and fibronectin) were found in abundance. Furthermore, several residual angiogenic factors were found in the decellularized SI. Following recellularization, we found viable mucin-positive goblet cells, CK18+ epithelial cells in villi adjacent to a muscularis mucosa with α-actin+ smooth muscle cells, and a high repopulation of blood vessels with CD31+ endothelial cells. Our results show that in the future, such a TESI would be ideal for clinical purposes, because it can be derived from the recipient's own immunocompatible bone marrow cells, thus avoiding the use of immunosuppression.
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