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Insulin-like growth factor-I (IGF-I) and keratinocyte growth factor (KGF) cDNA gene transfer individually improves dermal and epidermal regeneration. The aim of the present study was to determine whether the combination of IGF-I plus KGF cDNA further improves wound healing and by which mechanisms these changes occur. Rats received an acute wound and were divided into four groups to receive weekly subcutaneous injections of liposomes plus Lac Z cDNA, liposomes plus IGF-I cDNA, liposomes plus KGF cDNA, or liposomes plus IGF-I/KGF cDNA. Planimetry, immunological assays, histological and immunohistochemical techniques were used to determine IGF-I, KGF, platelet-derived growth factor, fibroblast growth factor (FGF), transforming growth factor-β and vascular endothelial growth factor (VEGF) expression and different types of collagen (I, III and IV). IGF-I, KGF and their combination cDNA treatment significantly (P<0.05) accelerated re-epithelization, increased IGF-I, KGF, FGF, VEGF and collagen type IV expression, while it had no effect on collagen type I and III expression. The combination of IGF-I plus KGF cDNA increased (P<0.05) neovascularization and VEGF expression when compared to IGF-I cDNA, KGF cDNA groups and controls. In conclusion, exogenous administration of liposomal IGF-I plus KGF cDNA enhanced dermal and epidermal regeneration which is due to increased neovascularization.Gene Therapy (2007) 14, 1235–1242; doi:10.1038/sj.gt.3302972; published online 31 May 2007 [ABSTRACT FROM AUTHOR]

Liposomal gene transfer is an effective therapeutic approach to improve dermal and epidermal regeneration. The purpose of the present study was to define whether the biological or chemical structure of a liposome influences cellular and biological regeneration in the skin, and to determine by which mechanisms possible changes occur. Rats were inflicted a full-excision acute wound and divided into three groups to receive weekly subcutaneous injections of DMRIE liposomes plus the Lac Z gene, or DOTAP/Chol liposomes plus the Lac Z gene, or saline. Planimetry, immunological assays, histological and immunohistochemical techniques were used to determine cellular responses after gene transfer, protein expression, dermal and epidermal regeneration. DOTAP/Chol increased IGF-I and KGF protein concentration and caused concomitant cellular responses, for example, by increasing IGFBP-3, P<0.05. DOTAP/Chol liposomes improved epidermal regeneration by exhibiting the most rapid area and linear wound re-epithelization compared to DMRIE or control, P<0.001. DOTAP/Chol and DMRIE exerted promitogenic and antiapoptotic effects on basal keratinocytes, P<0.05. Dermal regeneration was improved in DOTAP/Chol-treated animals by an increased collagen deposition and morphology, P<0.001. DOTAP/Chol liposomes increased vascular endothelial growth factor concentrations and thus neovascularization when compared with DMRIE and saline, P<0.001. In the present study, we showed that different liposomes have different effects on intracellular and biological responses based on its chemical and molecular structure. For gene transfer in acute wounds, the administration of DOTAP/Chol liposomes appears to be beneficial.Gene Therapy (2005) 12, 1718–1724. doi:10.1038/sj.gt.3302582; published online 7 July 2005 [ABSTRACT FROM AUTHOR]

Recent studies have confirmed that weedy Amaranthus species are capable of interspecific hybridization, and such hybridization may foster the evolution of herbicide resistance. However, the extent to which hybridization among these species occurs in nature is unknown. The purpose of this study was to determine the frequency under field conditions at which A. hybridus, a monoecious and predominantly self-pollinated species, would be pollinated by A. tuberculatus, a dioecious species. To do this, parents carrying different alleles at the ALS locus, which encodes a herbicide target site, were used. Male A. tuberculatus parents were homozygous for a dominant herbicide-insensitive allele, while A. hybridus parents were homozygous for a sensitive form. Hybrid progeny therefore could be detected via herbicide selection. Mean hybridization frequencies between 0.4 and 2.3%were obtained, depending on the proximity between parents (P=0.02). The robustness of the hybrid selection assay was verified using a molecular marker and DNA content analyses. Using these techniques, more than 99%of the progeny that survived the herbicide were confirmed to be hybrids. Frequencies obtained in this study were many times higher than the generally expected rate of mutation. Therefore, even minimal fertility in hybrid progeny would support the view that hybridization could play a role in adaptive evolution of weedy Amaranthus species.Heredity (2005) 94, 64-70. doi:10.1038/sj.hdy.6800563 Published online 18 August 2004 [ABSTRACT FROM AUTHOR]

Liposomal gene transfer is an effective therapeutic approach for the treatment of several pathophysiologic states. The purpose of the present study was to define whether gene transfer of multiple genes is a feasible approach and whether this approach would be more effective than the single transfer of cDNA. Rats were inflicted an acute wound and divided into four groups to receive weekly subcutaneous injections of liposomes plus the Lac-Z gene (0.22 μg, vehicle), or liposomes plus the insulin like-growth factor-I (IGF-I)cDNA (2.2 μg) and Lac Z gene (0.22 μg), or liposomes plus the keratinocyte growth factor (KGF) cDNA (2.2 μg) and Lac Z gene (0.22 μg), or liposomes plus the IGF-I/KGF cDNA (2.2 μg) and Lac Z gene (0.22 μg). Planimetry, immunological assays, histological and immunohistochemical techniques were used to determine molecular mechanisms after gene transfer, protein expression, dermal and epidermal regeneration. IGF-I/KGF cDNA transfer increased IGF-I and KGF protein concentration and caused concomitant cellular responses, for example,by increasing IGFBP-3, P<0.05. IGF-I/KGF cDNA gene transfer improved epidermal regeneration by exhibiting the most rapid area and linear wound re-epithelization by almost 250% compared to control and each growth factor given individually, P<0.001, which was probably due to promitogenic and antiapoptotic effects on basal keratinocytes when compared to controls, P<0.001. Dermal regeneration was improved in IGF-I/KGF cDNA-treated animals by an increased collagen deposition and morphology when compared with vehicle, IGF-I and KGF, P<0.001. IGF-I/KGF cDNA increased VEGF concentrations and thus neovascularization when compared with vehicle, IGF-I and KGF, P<0.001. In the present study, we showed that exogenous gene transfer of multiple cDNA sequences have an additive effect on intracellular and biological responses when compared to the same gene administered as a single cDNA sequence. Our findings demonstrate that gene therapy with multiple genes is feasible, and that the gene transfer of multiple genes can enhance and accelerate physiologic and biological effects. [ABSTRACT FROM AUTHOR]

Fluoroaluminate is a G-protein activator, it stimulates osteoblastic cells in culture, and is a bone-forming agent in vivo. To elucidate the mechanisms of G-protein-mediated action of fluoroaluminate in osteoblasts, we studied protein tyrosine phosphorylation in the preosteoblastic cell line MC3T3-E1. Fluoroaluminate, lysophosphatidic acid (LPA; an agonist for G-protein-coupled receptor), or adhesion to type I collagen all stimulated phosphorylation of a similar set of proteins, including p130, p120, p110 (previously identified as proline-rich tyrosine kinase 2, Pyk2), and p70. The phosphorylation of these proteins was sensitive to an Src inhibitor, but not to a Gi-protein inactivator, pertussis toxin. By purification/mass spectrometry and by immunodepletion, p130 protein was identified as p130 Cas (Crk-associated protein), a Src substrate and a protein involved in signaling by cell-adhesion receptors, integrins. Phosphorylation of immunoprecipitated p130 Cas increased upon stimulation with fluoroaluminate and with agonists of G-protein-coupled receptors, but not with growth factors. By immunodepletion, the p120 protein was identified as focal adhesion kinase, Fak. The addition of fluoroaluminate during cell attachment to type I collagen further stimulated phosphorylation of p130 Cas and of Fak. Simultaneously, fluoroaluminate increased the number of attached MC3T3-E1 cells and their spreading. These novel aspects of fluoroaluminate action in cell culture may be important for the bone-forming action of fluoroaluminate in vivo. [ABSTRACT FROM AUTHOR]

Exogenous insulin-like growth factor-I (IGF-I) is known to improve the pathophysiology of a thermal injury, however, deleterious side-effects have limited its utility. Cholesterol-containing cationic liposomes that encapsulate complementary DNA (cDNA) are nonviral carriers used for in vivo gene transfection. We propose that liposome IGF-I gene transfer will accelerate wound healing in burned rats and attenuate deleterious side-effects associated with high levels of IGF-I. To test this hypothesis IGF-I gene constructs, encapsulated in liposomes, were studied for their efficacy in modulating the thermal injury response. Thirty adult male Sprague–Dawley rats were given a 60% TBSA scald burn and randomly divided into three groups to receive weekly subcutaneous injections of liposomes plus the lacZ gene coding for β-galactosidase, liposomes plus cDNA for IGF-I and β-galactosidase or liposomes plus the rhIGF-I protein. Body weights and wound healing were measured. Muscle and liver dry/wet weights and IGF-I concentrations in serum, skin and liver were measured by radioimmunoassay. Transfection was confirmed by histochemical staining for β-galactosidase. Rats receiving the IGF-I cDNA constructs exhibited the most rapid wound re-epithelialization and greatest increase in body weight and gastrocnemius muscle protein content (P < 0.05). local igf-i protein concentrations in the skin were higher when compared to liposomes containing only the lacz gene (p < 0.05) transfection was apparent in the cytoplasm of myofibroblasts, endothelial cells and macrophages of the granulation tissue. liposomes containing the igf-i gene constructs proved effective in preventing muscle protein wasting and preserving total body weight after a severe thermal injury. [ABSTRACT FROM AUTHOR]

Introduction. Hepatic failure is one of the important features of septic multiorgan dysfunction. Previous studies have shown that, in septic rats, heat stress (HS) has a protective effect on bile acid transporters in hepatocyte membranes. This study investigates the influence of HS on hepatocyte membrane proteins, including the transporters oatp and mrp2, during endotoxemia. Methods. Endotoxemia in rats was induced by intraperitoneal injection of Escherichia coli Lipopolysaccharide (LPS), while control rats received saline. Half of each group was exposed to HS, 2 h prior to LPS or saline injection, by external warming to 42°C for 10 min and half of each group was exposed to ambient temperature 2 h prior to LPS or saline injection. Membrane fractions were extracted 0, 6,12, 24, 36, 72, and 108 h after LPS or saline treatment. Extracted proteins were separated using 2D gel electrophoresis. The most dominant spots were analyzed by MALDI-TOF. Transporter proteins, oatp and mrp2, were investigated by Western and Northern blot analysis. Results. The majority of the spots developed 24 h after injection. Membrane proteins, Wnt 13, ribosomal protein L14, VLCAD, BHMT, andHIT-40, were found only in HS-LPS. Protein profiles of the groups receiving either HS, LPS, or HS-LPS returned to normal after 72 h. Western blot analysis of oatp and mrp2 showed a down regulation only in the LPS group. Additionally, mRNA of oatp and mrp2 were prolonged down regulated only in the LPS group. Conclusion. We propose that, during endotoxemia, HS is an important stimulus in modulating and protecting the hepatic membrane proteins, which are involved in metabolism and protein synthesis. [Copyright &y& Elsevier]

Burn injury is a severe form of trauma affecting more than 2 million people in North America each year. Burn trauma is not a single pathophysiological event but a devastating injury that causes structural and functional deficits in numerous organ systems. Due to its complexity and the involvement of multiple organs, in vitro experiments cannot capture this complexity nor address the pathophysiology. In the past two decades, a number of burn animal models have been developed to replicate the various aspects of burn injury, to elucidate the pathophysiology, and to explore potential treatment interventions. Understanding the advantages and limitations of these animal models is essential for the design and development of treatments that are clinically relevant to humans. This review aims to highlight the common animal models of burn injury in order to provide investigators with a better understanding of the benefits and limitations of these models for translational applications. While many animal models of burn exist, we limit our discussion to the skin healing of mouse, rat, and pig. Additionally, we briefly explain hypermetabolic characteristics of burn injury and the animal model utilized to study this phenomena. Finally, we discuss the economic costs associated with each of these models in order to guide decisions of choosing the appropriate animal model for burn research. [ABSTRACT FROM AUTHOR]

Objectives: The objective of this study is to identify what burn survivors and front-line staff indicate would improve satisfaction with burn dressings, and the ranking of importance of different burn dressing characteristics. These findings will guide the development of future dressings to meet these needs.Methods: Burn survivors (including the person injured and their family) and front-line burn healthcare providers completed a questionnaire on the importance given to different burn dressing characteristics (non-stick, absorbent, able to wear for a long time, flexible, easy to put on, easy to take off, antimicrobial, and non-bulky), and about the adequacy of pain management during dressing changes.Results: A total of 99 individuals filled out the questionnaire (31 caregivers/survivors and 68 front-line burn healthcare providers). The most important dressing characteristics by both groups were "non-stick" and "fights infection". There was a significant difference between burn survivors and front-line burn healthcare providers pertaining to adequacy of pain management during dressing change. Adequate pain management was reported by 59% of burn survivors, which was significantly higher than that reported by the 25% front-line burn healthcare providers (p=0.002).Conclusions: Our study suggests that burn survivors and front-line burn providers have similar views on what constitutes an ideal dressing. A significantly proportion of caregiver/survivors felt that pain associated with dressing changes is being adequately managed despite healthcare providers' perception. [ABSTRACT FROM AUTHOR]

HYPOTHESIS:Obesity influences metabolism and increases the incidence of clinical complications and worsens outcomes in pediatric burn patients.DESIGN:Retrospective, single-center study.SUBJECTS:In all, 592 severely burned pediatric patients who had burns covering more than 30% of the total body surface area and who were treated between 2001 and 2008 were enrolled in this study. Patients were divided into 85th percentile (n=277) and normal (n=315) weight groups based on body mass index (BMI) percentiles.RESULTS:Patients stratified below (normal) and 85th percentile had similar age, gender distribution and total burn size. No significant differences were detected in the incidence of sepsis (11% for obese vs 10% for normal), the incidence of multiple organ failure (MOF) (21% for obese and 16% for normal) or mortality (11% for obese vs 8% for normal). Compared with the normal group, the 85th percentile group had low levels of constitutive proteins (α2macroglobulin and Apolipoprotein A1) (P<0.05 for both) as well as high levels of triglycerides and the acute-phase protein, C-reactive protein (P<0.05 for both) up to 60 days after injury. Patients 85th percentile showed a significant higher loss of bone mineral density and lipolysis compared with normal individuals. Stepwise logistic regression analysis revealed that BMI had a positive predictive value towards the maximum DENVER2 score, an index of organ failure (P<0.001).CONCLUSIONS:BMI85th percentile altered the post-burn acute phase and catabolic response but did not increase the incidence of sepsis, MOF or mortality in pediatric burn patients. Our results suggest that impaired metabolism and an altered inflammatory response already exists in patients starting at the 85th percentile BMI. [ABSTRACT FROM AUTHOR]

Liposomal gene transfer effectively enhances dermal and epidermal regeneration in burned rodents. To advance this treatment to clinical studies, we investigated the efficacy of liposomal gene transfer in a clinically relevant porcine wound model. Mimicking the clinical scenario, six female Yorkshire pigs (40–50 kg) received up to 12 burns of 50 cm2 area that were fully excised and covered with skin autograft meshed at 4:1 ratio 24 h post-burn. Animals received control injections (empty liposomes), liposomes (DMRIE-C) containing 1 mg LacZ-cDNA, or liposomes (DMRIE-C) with 1 mg of platelet-derived growth factor (PDGF)-cDNA, or the naked PDGF gene. Serial biopsies were taken from different wound sites at multiple time points up to 12 days post-wounding. Transfection efficacy and transfection rate of LacZ and localization of β-gal were determined by immunohistochemical and immunofluorescent techniques. RT-PCR and multiplex protein analysis (ELISA) were used to measure levels of growth factor mRNA transcribed and growth factor protein translated. Wound re-epithelialization and graft adhesion was evaluated using planimetric analysis and clinical scores. We found that peak transfection of liposomal β-galactosidase occurred on day 2, with a fluorescence increase of 154% to baseline (P<0.001). Transfection intensity dropped to 115% above baseline on day 4 (P<0.001) and 109% on day 7. Immunohistochemistry showed a maximum transfection rate of 34% of cells in wound tissue. Gene transfer of liposomal PDGF-cDNA resulted in increased PDGF-mRNA and protein expression on days 2 and 4, and accelerated wound re-epithlialization as well as graft adhesion on day 9 (P<0.05). In this study, we showed that liposomal cDNA gene transfer is possible in a porcine wound model, and by using PDGF-cDNA we further showed that dermal and epidermal regeneration can be improved. These data indicate that liposomal gene transfer can be a new therapeutic approach to improve wound healing in humans. [ABSTRACT FROM AUTHOR]

A letter to the editor in response to the article "Major psychological complications and decreased health-related quality of life among survivors of Stevens-Johnson syndrome and toxic epidermal necrolysis," that was published in a previous issue of the journal is presented.

Gene therapy was traditionally considered a treatment modality for patients with congenital defects of key metabolic functions or late-stage malignancies. The realization that gene therapy applications were much vaster has opened up endless opportunities for therapeutic genetic manipulations, especially in the skin and external wounds. Cutaneous wound healing is a complicated, multistep process with numerous mediators that act in a network of activation and inhibition processes. Gene delivery in this environment poses a particular challenge. Numerous models of gene delivery have been developed, including naked DNA application, viral transfection, high-pressure injection, liposomal delivery, and more. Of the various methods for gene transfer, cationic cholesterol-containing liposomal constructs are emerging as a method with great potential for non-viral gene transfer in the wound. This article aims to review the research on gene therapy in wound healing and possible future directions in this exciting field.Gene Therapy (2007) 14, 1–10. doi:10.1038/sj.gt.3302837; published online 24 August 2006 [ABSTRACT FROM AUTHOR]