| 1. |
- Angelidis, Ioannis K, et al.
(författare)
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Tissue Engineering of Flexor Tendons: The Effect of a Tissue Bioreactor on Adipoderived Stem Cell-Seeded and Fibroblast-Seeded Tendon Constructs
- 2010
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Ingår i: JOURNAL OF HAND SURGERY-AMERICAN VOLUME. - : Elsevier Science B.V., Amsterdam. - 0363-5023. ; 35A:9, s. 1466-1472
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Tissue-engineered flexor tendons could eventually be used for reconstruction of large tendon defects. The goal of this project was to examine the effect of a tissue bioreactor on the biomechanical properties of tendon constructs seeded with adipoderived stem cells (ASCs) and fibroblasts (Fs). Methods Rabbit rear paw flexor tendons were acellularized and seeded with ASCs or Fs. A custom bioreactor applied a cyclic mechanical load of 1.25 N at 1 cycle/minute for 5 days onto the tendon constructs. Three additional groups were used as controls: fresh tendons and tendons reseeded with either ASCs or Fs that were not exposed to the bioreactor treatment and were left in stationary incubation for 5 days. We compared the ultimate tensile stress (UTS) and elastic modulus (EM) of bioreactor-treated tendons with the unloaded control tendons and fresh tendons. Comparison across groups was assessed using one-way analysis of variance with the significance level set at pandlt;.05. Pairwise comparison between the samples was determined by using the Tukey test. Results The UTS and EM values of bioreactor-treated tendons that were exposed to cyclic load were significantly higher than those of unloaded control tendons. Acellularized tendon constructs that were reseeded with ASCs and exposed to a cyclic load had a UTS of 66.76 MPa and an EM of 906.68 MPa; their unloaded equivalents had a UTS of 47.90 MPa and an EM of 715.57 MPa. Similar trends were found in the fibroblast-seeded tendon constructs that were exposed to the bioreactor treatment. The bioreactor-treated tendons approached the UTS and EM values of fresh tendons. Histologically, we found that cells reoriented themselves parallel to the direction of strain in response to cyclic strain. Conclusions The application of cyclic strain on seeded tendon constructs that were treated with the bioreactor helped achieve a UTS and an EM comparable with those of fresh tendons. Bioreactor pretreatment and alternative cell lines, such as ASCs and Fs, might therefore contribute to the in vitro production of strong tendon material.
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| 2. |
- Antepohl, Wolfram, et al.
(författare)
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Interleukin-8 is elevated in cerebrospinal fluid following high-voltage electrical injury with late-onset paraplegia suggesting neuronal damage at the microlevel as causative factor
- 2010
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Ingår i: Burns. - : Pergamon Press. - 0305-4179 .- 1879-1409. ; 36:3, s. e7-e9
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Tidskriftsartikel (refereegranskat)abstract
- The patient, a 31-year-old male, sustained an electric burn injury (16 kV, AC/DC) while working with electric power lines. He was acutely admitted to a national burn center in Southeast Sweden, where burns equalling 29% of the total body surface area were noted. The burns were located at the front of the abdomen, upper arms bilaterally, and the left hip region, and the lesions were estimated to be mainly of the dermal type, what was believed initially to be caused mainly by an electric flash. There were no obvious entry or exit sites of the electric current. However, myoglobin in plasma was elevated as a sign of muscular degradation, suggesting that at least some current had passed through the tissues. According to the paramedic report there was an episode of a few minutes of unconsciousness immediately after the injury, but the patient was fully awake and alert on admission. There was no concomitant trauma.
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| 3. |
- Bergkvist, Max, 1976-
(författare)
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Studies on Polarised Light Spectroscopy
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis project focuses on measurements of dermal microcirculation during vascular provocations with polarised light spectroscopy. This is done with a non-invasive method commercially available as Tissue viability imaging (TiVi) which measures concentration and oxygenation of red blood cells in the papillary dermis. Three studies were done with human subjects and one with an animal model, to validate and compare the TiVi technique with laser Doppler flowmetry, which is an established method of measuring dermal microcirculation.The TiVi consists of a digital camera with polarisation filters in front of the flash and lens, with software for analysis of the picture. When taking a picture with the TiVi, the polarised light that is reflected on the skin surface is absorbed by the second filter over the lens (which is perpendicular to the first filter) but a portion of light penetrates the surface of the skin and is scattered when it is reflected on tissue components. This makes the light depolarised, passes the second filter, and produces a picture for analysis. The red blood cell (RBC) has a distinct absorption pattern that differs between red and green colour compared to melanin and other components of tissue. This difference is used by the software that calculates differences in each picture element and produces a measure of output which is proportional to the concentration of red blood cells. The oxygenation of RBC can also be calculated, as there is a difference in absorption depending on oxygen state.The first paper takes up possible sources of error such as ambient light, and the angle and distance of the camera. The main experiment was to investigate how the local heating reaction is detected with TiVi compared to LDF.In the second paper arterial and venous stasis are examined in healthy subjects with TiVi.The Third paper is an animal study where skin flaps were raised on pigs, and the vascular pedicle is isolated to enable control of inflow and outflow of blood.The measurements were made during partial venous, total venous, and total arterial occlusion. The TiVi recorded changes in the concentration of RBC, oxygenation and heterogeneity and the results were compared with those of laser Doppler flowmetry.In the fourth paper oxygenation and deoxygenation of RBC: s was studied. Studies were made on the forearms of healthy subjects who were exposed to arterial and venous occlusion. Simultaneous measurements were made with TiVi and Enhanced perfusion and oxygen saturation or EPOS, which is a new device that combines laser Doppler flowmetry and diffuse reflectance spectroscopy in one probe.With TiVi, one can measure RBC concentration and oxygenation in the area of an entire picture or in one or multiple user defined regions of interest (ROI). Methods such as laser Doppler flowmetry makes single point measurements, which is a potential source of error both because of the heterogeneity of the microcirculation, and that the circulation be insufficient in the margins of the investigated area. TiVi has been able to measure venous stasis more accurately than laser Doppler flowmetry, and venous stasis is the more common reason for flaps to fail.The TiVi is an accurate way to measure the concentration of RBC and trends in oxygenation of the dermal microcirculation. It has interesting possible applications for microvascular and dermatological research, monitoring of flaps, and diagnosis of peripheral vascular disease. Future clinical studies are needed as well as development of the user interface.
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| 4. |
- Chatzikokkinou, P., et al.
(författare)
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Spontaneous endometriosis in an umbilical skin lesion
- 2009
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Ingår i: Acta Dermatovenerologica Alpina, Pannonica et Adriatica. - 1318-4458. ; 18:3, s. 126-130
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Tidskriftsartikel (refereegranskat)abstract
- Cutaneous endometriosis of the umbilicus is an unusual condition with unclear pathogenetic mechanisms that might be mistaken for a malignant condition. A 46-year-old woman presented with a cutaneous black mass in the umbilicus. The lesion was removed surgically and histological analyses revealed that it consisted of endometrial tissue. There was no recurrence at 18-month follow-up. Endometriosis of the umbilicus is a rare condition and the pathogenesis is not completely elucidated. According to one theory, intraperitoneal endometrial tissue is translocated during endoscopic surgery or other surgical procedures that involve the umbilicus. However, in this case there was no history of abdominal wall surgery. We conclude that endometriosis is important to consider in cases of unclear skin lesions of the umbilicus, even in cases with no previous abdominal surgery. Moreover, umbilical endometriosis of the skin can have different appearances that resemble malignant tumors, and radical surgery with histology is therefore indicated.
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| 5. |
- Elmasry, Moustafa, et al.
(författare)
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Scald management protocols - outcome differences in two different time periods using different treatment strategies.
- 2016
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Ingår i: Annals of burns and fire disasters. - : Mediterranean Council for Burns and Fire Disasters. - 1592-9558. ; 29:2, s. 139-143
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Tidskriftsartikel (refereegranskat)abstract
- Over the years the treatment of scalds in our centre has changed, moving more towards the use of biological dressings (xenografts). Management of scalds with mid dermal or deep dermal injuries differs among centers using different types of dressings, and recently biological membrane dressings were recommended for this type of injury. Here we describe differences in treatment outcome in different periods of time. All patients with scalds who presented to the Linkoping Burn Centre during two periods, early (1997-98) and later (2010-12) were included. Data were collected in the unit database and analyzed retrospectively. A lower proportion of autograft operations was found in the later period, falling from 32% to 19%. Hospital stay was shorter in the later period (3.5 days shorter, p=0.01) and adjusted duration of hospital stay/TBSA% was shorter (1.2 to 0.7, p=0.07). The two study groups were similar in most of the studied variables: we could not report any significant differences regarding outcome except for unadjusted duration of hospital stay. Further studies are required to investigate functional and aesthetic outcome differences between the treatment modalities.
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| 6. |
- Elmasry, Moustafa, et al.
(författare)
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Staged excisions of moderate-sized burns compared with total excision with immediate autograft : an evaluation of two strategies.
- 2017
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Ingår i: International journal of burns and trauma. - : E-Century Publishing Corporation. - 2160-2026. ; 7:1, s. 6-11
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Different surgical techniques have evolved since excision and autografting became the treatment of choice for deep burns in the 1970s. The treatment plan at the Burn Center, Linköping University Hospital, Sweden, has shifted from single-stage excision and immediate autografting to staged excisions and temporary cover with xenografts before autografting. The aim of this study was to find out if the change in policy resulted in extended duration of hospital stay/total body surface area burned (LOS/TBSA%).METHODS: Retrospective clinical cohort including surgically-managed patients with burns of 15%-60% TBSA% within each treatment group. The first had early full excisions of deep dermal and full thickness burns and immediate autografts (1997-98), excision and immediate autograft group) and the second had staged excisions before final autografts using xenografts for temporary cover (2010-11, staged excision group).RESULTS: The study included 57 patients with deep dermal and full-thickness burns, 28 of whom had excision and immediate autografting, and 29 of whom had staged excisions with xenografting before final autografting. Adjusted (LOS/TBSA%) was close to 1, and did not differ between groups. Mean operating time for the staged excision group was shorter and the excised area/operation was smaller. The total operating time/TBSA% did not differ between groups.CONCLUSION: Staged excisions with temporary cover did not affect adjusted LOS/TBSA% or total operating time. Staged excisions may be thought to be more expensive because of the cost of covering the wound between stages, but this needs to be further investigated as do the factors that predict long term outcome.
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| 7. |
- Elmasry, Moustafa, et al.
(författare)
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Temporary coverage of burns with a xenograft and sequential excision, compared with total early excision and autograft
- 2016
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Ingår i: Annals of burns and fire disasters. - : Mediterranean Council for Burns and Fire Disasters. - 1592-9558. ; 29:3, s. 196-201
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Tidskriftsartikel (refereegranskat)abstract
- During the 80s and 90s, early and total excision of full thickness burns followed by immediate autograft was the most common treatment, with repeated excision and grafting, mostly for failed grafts. It was hypothesized, therefore, that delayed coverage with an autograft preceded by a temporary xenograft after early and sequential smaller excisions would lead to a better wound bed with fewer failed grafts, a smaller donor site, and possibly also a shorter duration of stay in hospital. We carried out a case control study with retrospective analysis from our National Burn Centre registry for the period 1997-2011. Patients who had been managed with early total excision and autograft were compared with those who had had sequential smaller excisions covered with temporary xenografts until the burn was ready for the final autograft. The sequential excision and xenograft group (n=42) required one-third fewer autografts than patients in the total excision and autograft group (n=45), who needed more than one operation (p<0.001). We could not detect any differences in duration of stay in hospital / total body surface area burned% (duration of stay/TBSA%) (2.0 and 1.8) (p=0.83). The two groups showed no major differences in terms of adjusted duration of stay, but our findings suggest that doing early, smaller, sequential excisions using a xenograft for temporary cover can result in shorter operating times, saving us the trouble of making big excisions. However, costs tended to be higher when the burns were > 25% TBSA.
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| 8. |
- Elmasry, Moustafa, et al.
(författare)
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Treatment of Children With Scalds by Xenografts: Report From a Swedish Burn Centre
- 2016
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Ingår i: Journal of Burn Care & Research. - : LIPPINCOTT WILLIAMS & WILKINS. - 1559-047X .- 1559-0488. ; 37:6, s. E586-E591
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Tidskriftsartikel (refereegranskat)abstract
- Scalds are the most common type of burn in children, and one way to treat them is with xenografts with no topical antimicrobials in line with the recommendations of a recent review. However, this treatment has not been examined in detail. Our aim was to describe the treatment of such children when biological dressings (xenografts) were used without local antimicrobials. We reviewed the medical records of all children admitted to a Swedish National Burn Centre during the period 2010-2012 with scalds who were treated with xenografts. Percentage TBSA injured, age, length of hospital stay, number of operations, antibiotics given, duration of antibiotic treatment, and pain score during the first 3 days, application of xenografts, and clinical notes of wound infection were recorded. We studied 67 children, (43 of whom were boys), with a median (interquartile range [IQR]) age of 1 (1-2) year and median (IQR) TBSA% 6.2 (4-11). Twenty children (30%) required operation. Twelve (18%) developed a wound infection, 29 (43%) had other infections, and 26 (39%) were free from infection. The median (IQR) duration of systemic antibiotics was 10 (6-13) days. On the day that the xenografts were applied 10 of the children had a Face, Legs, Activity, Cry, and Consolability (FLACC) score between 3 and 7, and during the following 2 days, only four children scored in this range. The remaining 57 children had scores amp;lt;3 on the day that xenografts were applied and on the following 2 days. Median (IQR) length of stay/TBSA% was 0.7 (0.4-1.0). Treatment with xenografts was associated with median length of stay/TBSA% amp;lt; 1 and low pain scores. Despite a high rate of prescription of systemic antibiotics, most were for reasons other than wound infection.
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| 9. |
- Farnebo, Simon, et al.
(författare)
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Hyperaemic changes in forearm skin perfusion and RBC concentration after increasing occlusion times
- 2010
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Ingår i: MICROVASCULAR RESEARCH. - : Elsevier Science B.V., Amsterdam. - 0026-2862. ; 80:3, s. 412-416
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Tidskriftsartikel (refereegranskat)abstract
- Tissue occlusion and the hyperaemic response upon reperfusion can be used as a tool to assess microvascular function in various vascular diseases. Currently, laser Doppler flowmetry (LDF) is applied most often to measure hyperaemic responses. In this study, we have applied tissue viability imaging (TiVi) and LDF to measure the change in red blood cell concentration and perfusion in the skin after occlusions of the forearm with increasing duration. We have found that there is a strong correlation between the changes in perfusion and red blood cell (RBC) concentration during post-occlusive hyperaemia (perfusion: r = 0.80; RBC concentration: r = 0.94). This correlation increases with longer occlusion durations (1, 5 and 10 min). Furthermore, for both perfusion and RBC concentration, the maximum responses (perfusion: r(2) = 0.59; RBC concentration: r(2) = 0.78) and the recovery times (perfusion: r(2) = 0.62; RBC concentration: r(2) = 0.91) increase linearly with the duration of the occlusion. Maximum responses and recovery times were more reproducible for RBC concentration (as measured with TiVi) than for perfusion (as measured with LDF). These results show that perfusion and RBC concentration are related during post-occlusive hyperaemia and that TiVi can be used as a tool in the assessment of hyperaemic responses that has advantages in terms of reproducibility, sensitivity and ease of use.
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| 10. |
- Frew, Quentin, et al.
(författare)
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Betulin wound gel accelerated healing of superficial partial thickness burns : Results of a randomized, intra-individually controlled, phase III trial with 12-months follow-up
- 2019
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Ingår i: Burns. - : Elsevier. - 0305-4179 .- 1879-1409. ; 45:4, s. 876-890
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Acceleration of wound healing promises advantages for patients and caregivers in reducing the burden of disease, avoiding complications such as wound infections, and improving the long-term outcome. However, medicines that can accelerate wound healing are lacking. The objective of this open, blindly evaluated, randomized, multicenter phase III study was to compare intra-individually the efficacy and tolerability of Oleogel-S10 with fatty gauze dressing versus Octenilin (R) wound gel with fatty gauze dressing in accelerating the healing of superficial partial thickness burn wounds. Methods: Acute superficial partial thickness burn wounds in adults caused by fire, heat burn or scalding were divided into 2 halves and randomly assigned to treatment with Oleogel-S10 or Octenilin (R) wound gel. Photos for observer-blinded analysis of wound healing were taken at each wound dressing change. Percentages of reepithelialization were assessed at defined intervals. Efficacy and tolerability were evaluated based on a 5-point Likert scale. Results: Of 61 patients that were enrolled, 57 received the allocated intervention and 48 completed treatment. The percentage of patients with earlier wound healing was significantly higher for Oleogel-S10 (85.7%, n=30) compared to Octenilin (R) wound gel (14.3%, n= 5, p <0.0001). The mean intra-individual difference in time to wound closure was -1.0 day in favour of Oleogel-S10 (-1.4, -0.6; 95% CI, p <0.0001). Most investigators (87.0%) and patients (84.8%) evaluated the efficacy of Oleogel-S10 to be 'better' or 'much better' than that of Octenilin (R) wound gel. Long-term outcome 3 months and 12 months post injury was improved in some patients. Conclusions: Oleogel-S10 (Episalvan) significantly accelerated the healing of superficial partial thickness burn wounds. It was safe and well tolerated. (C) 2018 Elsevier Ltd and ISBI. All rights reserved.
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