Surveillance of antibiotic susceptibility in a Swedish Burn Center 1994-2012.

UNLABELLED: 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 Linköping 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 Linköping 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 3(rd) 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.

Use of macroporous gelatine spheres as a biodegradable scaffold for guided tissue regeneration of healthy dermis in humans: an in vivo study.

If a biodegradable scaffold is applied, the dermis can be regenerated by guided tissue regeneration. Scaffolds can stimulate in-growth of cells from the surroundings that migrate into them and start to produce autologous extracellular matrix as the scaffold is degraded. Several materials are available, but most of them are in the form of sheets and need to be laid on an open wound surface. A number of injectable fillers have been developed to correct soft-tissue defects. However, none of these has been used for guided tissue regeneration. We present a new technique that could possibly be used to correct dermal defects by using macroporous gelatine spheres as a biodegradable scaffold for guided tissue regeneration. In eight healthy volunteers, intradermal injections of macroporous gelatine spheres were compared with injections of saline and hyaluronic acid (Restylane). Full-thickness skin biopsy specimens of the implants and surrounding tissue were removed 2, 8, 12 and 26 weeks after injection, and the (immuno)histological results were analysed. The Restylane merely occupied space. It shattered the dermal tissue and compressed collagen fibres and cells at the interface between the implant and the dermis. No regeneration of tissue was found with this material at any time. The macroporous gelatine spheres were populated with fibroblasts already after 2 weeks. After 8 weeks the spheres were completely populated by fibroblasts producing dermal tissue. After 12 and 26 weeks, the gelatine spheres had been more or less completely resorbed and replaced by vascularised neodermis. There were no signs of capsular formation, rejection or adverse events in any subject. Further in vivo studies in humans are needed to evaluate the effect of the macroporous spheres fully as a matrix for guided tissue regeneration with and without cellular pre-seeding. However, the results of this study indicate the possibility of using macroporous gelatine spheres as an injectable, three-dimensional, degradable matrix for guided tissue regeneration.

A Novel Concept for Treating Large Necrotizing Fasciitis Wounds With Bilayer Dermal Matrix, Split-thickness Skin Grafts, and Negative Pressure Wound Therapy.

Treatment of necrotizing fasciitis (NF) includes radical surgical debridement often resulting in large wounds that need to be closed with methods including split-thickness skin grafts (STSG), local flaps, or guided tissue regeneration procedures. In this case report, a 45 year-old Caucasian male was surgically treated for a benign left groin hernia, developed NF, and was transferred to the authors' burn unit. The wound was treated initially with wide debridement and with a brief delay before finally closing the wound. A collagen matrix such as Integra® Dermal Regeneration Template (Integra LifeSciences, Plainsboro, NJ) in combination with STSG and negative pressure wound treatment, can provide fast recovery resulting in pliable, functional skin..

Macroporous gelatine spheres as culture substrate, transplantation vehicle, and biodegradable scaffold for guided regeneration of soft tissues. In vivo study in nude mice.

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.

Burns in Sweden: an analysis of 24,538 cases during the period 1987-2004.

Burn care is always progressing, but there is little epidemiological information giving a clear picture of the current number of treated burns in Sweden. This study was conducted to provide an update of patients admitted to hospital with burns in Sweden. Data were obtained for all patients who were admitted to hospitals with a primary or secondary diagnosis of burns (ICD-9/10 codes) from 1 January 1987 to 31 December 2004; 24,538 patients were found. Most of the patients were male (69%), giving a male:female ratio of 2.23:1. Children in the age-group 0-4 years old predominated, and accounted for 27% of the study material. The median length of stay was 3 days. Throughout the period 740 patients (3%) died of their burns. Significant reductions in mortality, incidence, and length of stay were seen during the study, which correlates well with other studies. However, most of the reductions were in the younger age-groups. Men accounted for the improved mortality, as female mortality did not change significantly. We think that the improvement in results among patients admitted to hospital after burns is a combination of preventive measures, improved treatment protocols, and an expanding strategy by which burned patients are treated as outpatients.

Estradiol increases VEGF in human breast studied by whole-tissue culture.

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.

Buses as fire hazards: a Swedish problem only? Suggestions for fire-prevention measures.

In Sweden, approximately 6% of all human transportation is made via buses. The Swedish Board of Accident Investigation and the Swedish Rescue Services Agency have pointed out repeatedly that buses are potential fire and burn hazards, not only when involved in collisions but also in other circumstances. The number of fire incidents is increasing, especially in newer buses. In conjunction with the Swedish Rescue Services Agency, we examined some of the recent bus fires in Sweden. We did not find any casualties, but the results of our study suggest that casualties as a result of bus fires are imminent unless preventive measures are taken. We also studied experiences from previous bus fires and suggest preventive measures.

Adipose tissue processed for lipoinjection shows increased cellular survival in vitro when tissue engineering principles are applied.

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.