| 1. |
- Fransen, Jian, et al.
(författare)
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Surveillance of antibiotic susceptibility in a Swedish Burn Center 1994-2012
- 2016
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Ingår i: Burns. - : Elsevier BV. - 0305-4179 .- 1879-1409. ; 42:6, s. 1295-1303
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Tidskriftsartikel (refereegranskat)abstract
- Patients with burn trauma are at risk for infections caused by antibiotic resistant bacteria (ABR) with subsequent increase in morbidity and mortality. As part of the Swedish strategic program against antibiotic resistance in intensive care (ICU-Strama), we have surveyed the distribution of species and ABR in isolates from patients admitted to a Swedish burn center at Linkoping University Hospital from 1994 through 2012. In an international comparison Strama has been successful in reducing the antibiotic consumption among animals and humans in primary care. The aim of this study was to investigate the antibiotic consumption pressure and resistance rates in a Swedish burn unit. Methods: Microbiology data, total body surface area (TBSA), patient days, and mortality were collected from a hospital database for all patients admitted to the Burn Center at the University Hospital of Linkoping from April 1994 through December 2012. Results: A total of 1570 patients were admitted with a mean annual admission rate of 83 patients (range: 57-152). 15,006 microbiology cultures (approximately 10 per patient) were collected during the study period and of these 4531 were positive (approximately 3 per patient). The annual mean total body surface area (TBSA) was 13.4% (range 9.5-18.5) with an annual mortality rate of 5.4% (range 1-8%). The MRSA incidence was 1.7% (15/866) which corresponds to an MRSA incidence of 0.34/1000 admission days (TAD). Corresponding figures were for Escherichia coli resistant to 3rd generation cephalosporins (ESBL phenotype) 8% (13/170) and 0.3/TAD, Klebsiella spp. ESBL phenotype 5% (6/134) and 0.14/TAD, carbapenem resistant Pseudomonas aeruginosa 26% (56/209) and 1.28/TAD, and carbapenem resistant Acinetobacter spp. 3% (2/64) and 0.04/TAD. Conclusions: Our results show a sustained low risk for MRSA and high, although not increasing, risk for carbapenem resistant P. aeruginosa.
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| 2. |
- Garvin, Stina, et al.
(författare)
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Estradiol increases VEGF in human breast studied by whole-tissue culture.
- 2006
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Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 325:2, s. 245-51
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Tidskriftsartikel (refereegranskat)abstract
- Sex steroid exposure constitutes a risk factor for breast cancer, but little is known about the effects of sex steroids on the normal breast, largely because of the lack of convenient models. We have developed a method of culturing normal breast tissue ex vivo. We have applied this method to investigate the effects of estradiol and progesterone on the key angiogenic mediator, vascular endothelial growth factor (VEGF), in the breast. Whole breast tissue was obtained from routine reduction mammoplasty. Tissue biopsies were cultured in vitro for 1-3 weeks, and the expression of luminal cytokeratin 18 was determined by immunohistochemistry. As an application, tissue biopsies were treated in vitro for 1 week with or without estradiol or estradiol and progesterone. Estrogen receptor, progesterone receptor, and Ki-67 were analyzed, and VEGF levels were examined by quantitative immunoassay and immunohistochemistry. Whole breast tissue was cultured ex vivo for 1 week with preserved morphology. Increased detachment of the luminal epithelium was observed after 2 weeks. Estradiol increased extracellular levels of VEGF in normal breast tissue biopsy medium. The addition of progesterone had neither stimulatory nor inhibitory effects on secreted VEGF. The method of whole breast tissue culturing thus provide a means by which to explore the biology of normal breast tissue. Our results suggest that estradiol exerts pro-angiogenic effects in normal breast by increasing levels of biologically active VEGF.
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| 3. |
- Garvin, Stina, et al.
(författare)
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Estradiol increases VEGF in normal human breast studied by whole-tissue culture
- 2006
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Ingår i: Cell Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 325:2, s. 245-251
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Tidskriftsartikel (refereegranskat)abstract
- Sex steroid exposure constitutes a risk factor for breast cancer, but little is known about the effects of sex steroids on the normal breast, largely because of the lack of convenient models. We have developed a method of culturing normal breast tissue ex vivo. We have applied this method to investigate the effects of estradiol and progesterone on the key angiogenic mediator, vascular endothelial growth factor (VEGF), in the breast. Whole breast tissue was obtained from routine reduction mammoplasty. Tissue biopsies were cultured in vitro for 1–3 weeks, and the expression of luminal cytokeratin 18 was determined by immunohistochemistry. As an application, tissue biopsies were treated in vitro for 1 week with or without estradiol or estradiol and progesterone. Estrogen receptor, progesterone receptor, and Ki–67 were analyzed, and VEGF levels were examined by quantitative immunoassay and immunohistochemistry. Whole breast tissue was cultured ex vivo for 1 week with preserved morphology. Increased detachment of the luminal epithelium was observed after 2 weeks. Estradiol increased extracellular levels of VEGF in normal breast tissue biopsy medium. The addition of progesterone had neither stimulatory nor inhibitory effects on secreted VEGF. The method of whole breast tissue culturing thus provide a means by which to explore the biology of normal breast tissue. Our results suggest that estradiol exerts pro-angiogenic effects in normal breast by increasing levels of biologically active VEGF.
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| 4. |
- Heyland, Daren K., et al.
(författare)
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A Randomized Trial of Enteral Glutamine for Treatment of Burn Injuries
- 2022
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Ingår i: New England Journal of Medicine. - : Massachusetts Medical Society. - 0028-4793 .- 1533-4406. ; 387:11, s. 1001-1010
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUNDGlutamine is thought to have beneficial effects on the metabolic and stress response to severe injury. Clinical trials involving patients with burns and other critically ill patients have shown conflicting results regarding the benefits and risks of glutamine supplementation.METHODSIn a double-blind, randomized, placebo-controlled trial, we assigned patients with deep second-or third-degree burns (affecting >= 10% to >= 20% of total body-surface area, depending on age) within 72 hours after hospital admission to receive 0.5 g per kilogram of body weight per day of enterally delivered glutamine or placebo. Trial agents were given every 4 hours through a feeding tube or three or four times a day by mouth until 7 days after the last skin grafting procedure, discharge from the acute care unit, or 3 months after admission, whichever came first. The primary outcome was the time to discharge alive from the hospital, with data censored at 90 days. We calculated subdistribution hazard ratios for discharge alive, which took into account death as a competing risk.RESULTS A total of 1209 patients with severe burns (mean burn size, 33% of total body-surface area) underwent randomization, and 1200 were included in the analysis (596 patients in the glutamine group and 604 in the placebo group). The median time to discharge alive from the hospital was 40 days (interquartile range, 24 to 87) in the glutamine group and 38 days (interquartile range, 22 to 75) in the placebo group (subdistribution hazard ratio for discharge alive, 0.91; 95% confidence interval [CI], 0.80 to 1.04; P = 0.17). Mortality at 6 months was 17.2% in the glutamine group and 16.2% in the placebo group (hazard ratio for death, 1.06; 95% CI, 0.80 to 1.41). No substantial between-group differences in serious adverse events were observed.CONCLUSIONSIn patients with severe burns, supplemental glutamine did not reduce the time to discharge alive from the hospital.
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| 5. |
- Huss, Fredrik R.M., et al.
(författare)
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Adipose tissue processed for lipoinjection shows increased cellular survival in vitro when tissue engineering principles are applied : Culture techniques and survival of fat
- 2002
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Ingår i: Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery. - 0284-4311 .- 1651-2073. ; 36:3, s. 166-171
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Tidskriftsartikel (refereegranskat)abstract
- Correcting soft tissue defects by autologous fat grafting is a routine procedure in plastic surgery. Its efficacy and safety has been discussed extensively and several techniques of lipoinjection have been developed. However, one is bound to overcorrect by 30%-70% or need to repeat the procedure because of resorption of the transplant. The reasons are that many of the transplanted cells are already differentiated, and also that there is no nutritional support to the inner cell layers when they are transplanted as fragments. By culturing autologous adipocytes one can ensure that only non-differentiated, but committed, preadipocytes are transplanted and the procedure can be done in a way that ensures optimal nutritional support for the cells. In the present study we have compared our cell culture technique with two common clinical ways of processing liposuction material and found that (pre)adipocytes survive and proliferate significantly better in cell culture.
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| 6. |
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| 7. |
- Huss, Fredrik R.M. 1971-
(författare)
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In vitro and in vivo studies of tissue engineering in reconstructive plastic surgery
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- To correct, improve, and maintain tissues, and their functions, are common denominators in tissue engineering and reconstructive plastic surgery. This can be achieved by using autolo-gous tissues as in flaps or transplants. However, often autologous tissue is not useable. This is one of the reasons for the increasing interest among plastic surgeons for tissue engineering, and it has led to fruitful cross-fertilizations between the fields. Tissue engineering is defined as an interdisciplinary field that applies the principles of engineering and life sciences for development of biologic substitutes designed to maintain, restore, or improve tissue functions. These methods have already dramatically improved the possibilities to treat a number of medical conditions, and can arbitrarily be divided into two main principles:> Methods where autologous cells are cultured in vitro and transplanted by means of a cell suspension, a graft, or in a 3-D biodegradable matrix as carrier.> Methods where the tissue of interest is stimulated and given the right prerequisites to regenerate the tissue in vivo/situ with the assistance of implantation of specially designed materials, or application of substances that regulate cell functions - guided tissue regeneration.We have shown that human mammary epithelial cells and adipocytes could be isolated from tissue biopsies and that the cells kept their proliferative ability. When co-cultured in a 3-D matrix, patterns of ductal structures of epithelial cells embedded in clusters of adipocytes, mimicking the in vivo architecture of human breast tissue, were seen. This indicated that human autologous breast tissue can be regenerated in vitro.The adipose tissue is also generally used to correct soft tissue defects e.g. by autologous fat transplantation. Alas 30-70% of the transplanted fat is commonly resorbed. Preadipocytes are believed to be hardier and also able to replicate, and hence, are probably more useful for fat transplantation. We showed that by using cell culture techniques, significantly more pre-adipocytes could survive and proliferate in vitro compared to two clinically used techniques of fat graft handling. Theoretically, a biopsy of fat could generate enough preadipocytes to seed a biodegradable matrix that is implanted to correct a defect. The cells in the matrix will replicate at a rate that parallels the vascular development, the matrix subsequently degrades and the cell-matrix complex is replaced by regenerated, vascularized adipose tissue.We further evaluated different biodegradable scaffolds usable for tissue engineering of soft tissues. A macroporous gelatin sphere showed several appealing characteristics. A number of primary human ecto- and mesodermal cells were proven to thrive on the gelatin spheres when cultured in spinner flasks. As the spheres are biodegradable, it follows that the cells can be cultured and expanded on the same substrate that functions as a transplantation vehicle and scaffold for tissue engineering of soft tissues.To evaluate the in vivo behavior of cells and gelatin spheres, an animal study was performed where human fibroblasts and preadipocytes were cultured on the spheres and injected intra-dermally. Cell-seeded spheres were compared with injections of empty spheres and cell suspensions. The pre-seeded spheres showed a near complete regeneration of the soft tissues with neoangiogenesis. Some tissue regeneration was seen also in the ‘naked’ spheres but no effect was shown by cell injections.In a human pilot-study, intradermally injected spheres were compared with hyaluronan. Volume-stability was inferior to hyaluronan but a near complete regeneration of the dermis was proven, indicating that the volume-effect is permanent in contrast to hyaluronan which eventually will be resorbed. Further studies are needed to fully evaluate the effect of the macroporous gelatin spheres, with or without cellular pre-seeding, as a matrix for guided tissue regeneration. However, we believe that the prospect to use these spheres as an injectable, 3D, biodegradable matrix will greatly enhance our possibilities to regenerate tissues through guided tissue regeneration.
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| 8. |
- Huss, Fredrik R.M., et al.
(författare)
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Macroporous gelatine spheres as culture substrate, transplantation vehicle, and biodegradable scaffold for guided regeneration of soft tissues. : In vivo study in nude mice
- 2007
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Ingår i: Journal of Plastic, Reconstructive, and Aesthetic Surgery. - : Elsevier BV. - 1748-6815 .- 1878-0539. ; 60:5, s. 543-555
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Tidskriftsartikel (refereegranskat)abstract
- In the course of development of a new type of filler for the correction of small defects in soft tissues we studied macroporous gelatine spheres as culture substrate, transplantation vehicle, and biodegradable scaffold for guided regeneration of soft tissues in vivo. We injected intradermally in nude mice gelatine spheres that had either been preseeded with human fibroblasts or preadipocytes, or left unseeded. We compared the extent of regenerated tissue with that found after injections of saline or single-cell suspensions of human fibroblasts or preadipocytes. Routine histological examinations and immunohistochemical staining for von Willebrand factor (indicating neoangiogenesis) were made after 7, 21, and 56 days. Injected saline or single-cell suspensions had no effect. However, a quick and thorough tissue regeneration with developing neoangiogenesis was elicited by the gelatine spheres and the effect of spheres preseeded with preadipocytes surpassed the effect of spheres preseeded with fibroblasts, which in turn surpassed the effect of unseeded gelatine spheres. We suggest that minor soft tissue defects such as wrinkles or creases can be corrected by injection of naked macroporous gelatine spheres, whereas larger defects are best corrected by injection of macroporous gelatine spheres preseeded with fibroblasts, or preadipocytes, or both.
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| 9. |
- Huss, Fredrik R.M., et al.
(författare)
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Mammary epithelial cell and adipocyte co-culture in a 3-D matrix : The first step towards tissue-engineered human breast tissue
- 2001
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Ingår i: Cells Tissues Organs. - : S. Karger AG. - 1422-6405 .- 1422-6421. ; 169:4, s. 361-367
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Tidskriftsartikel (refereegranskat)abstract
- Reconstruction of the female breast after cancer surgery is a demanding task where the methods used today suffer from several disadvantages. In the present study we have investigated the possibility to use tissue engineering methods to regenerate human autologous breast tissue. Human mammary epithelial cells and preadipocytes were derived from breast tissue biopsies from healthy women undergoing reduction mammoplasty, and the two celltypes were co-cultured with conventional cell culture methods as well as in 3-D matrices. The study shows that it is possible to harvest both human mammary epithelial cells and preadipocytes in a single session, propagate several subcultures, and that the cells maintain a normal intercellular distribution and growth-pattern when co-cultured in a 3-D collagen gel. We propose that growth and formation of a tissue closely resembling normal human breast tissue be readily obtained in the described in vitro cell culture set-up using basic tissue engineering principles. This concept may be of great importance in the development of new methods for reconstruction of the human breast.
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| 10. |
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