Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
1.
Burns ; 43(8): 1673-1681, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29089204

RESUMEN

BACKGROUND: Prolonged operative time and intraoperative hypothermia are known to have deleterious effects on surgical outcomes. Although millions of burn injuries undergo operative treatment globally every year, there remains a paucity of evidence to guide perioperative practice in burn surgery. This study evaluated associations between hypothermia and operative time on post-operative complications in acute burn surgery. METHOD: A historical cohort study from January 1, 2006 to October 31, 2015 was completed at an American Burn Association verified burn centre. 1111 consecutive patients undergoing acute burn surgery were included, and 2171 surgeries were analyzed. Primary outcomes included post-operative complications, defined a priori as either infectious or noninfectious. Statistical analysis was undertaken using a modified Poisson model for relative risk, adjusted for total body surface area, inhalation injury, co-morbidities, substance abuse, and age. RESULTS: The mean operative time was 4.4h (SD 3.7-4.7h; range 0.58-11h), and 18.6% of patients became hypothermic intra-operatively. Operative time was independently associated with the incidence of hypothermia (p<0.05), and both infectious (RR1.5; 1.2-1.9, p<0.0004) and non-infectious complications (RR2.3; 1.3-4.1, p<0.0066). In patients with major burns (TBSA≥20%), hypothermia predisposed to infectious (RR1.3; 1.1-1.5, p<0.0017) and non-infectious complications (RR1.7; 1.2-2.5; p<0.0049). Risk stratification revealed that hypothermic patients with major burns undergoing prolonged surgery had an increased risk of both infectious (RR1.4; 1.1-1.7, p<0.0068) and non-infectious complications (RR1.8; 1.1-3.0, p<0.0132) when compared with those without these risk factors. CONCLUSIONS: Patients who undergo prolonged surgeries and become hypothermic are more likely to develop complications. We therefore advocate for diligent adherence to strategies to prevent hypothermia and recommend limiting operative time in clinical circumstances where intraoperative measures are unlikely to adequately prevent hypothermia.


Asunto(s)
Quemaduras/cirugía , Hipotermia/epidemiología , Tempo Operativo , Complicaciones Posoperatorias/epidemiología , Enfermedad Aguda , Adulto , Anciano , Quemaduras/complicaciones , Femenino , Humanos , Hipotermia/etiología , Incidencia , Masculino , Persona de Mediana Edad , Periodo Perioperatorio/estadística & datos numéricos , Distribución de Poisson , Complicaciones Posoperatorias/etiología , Factores de Riesgo , Infección de la Herida Quirúrgica/epidemiología , Adulto Joven
2.
Cell Mol Life Sci ; 71(17): 3241-55, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24714880

RESUMEN

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.


Asunto(s)
Experimentación Animal , Quemaduras , Modelos Animales , Animales , Animales de Laboratorio , Tamaño Corporal , Quemaduras/metabolismo , Quemaduras/patología , Quemaduras/fisiopatología , Quemaduras/terapia , Costos y Análisis de Costo , Metabolismo Energético , Ratones , Conejos , Ratas , Investigación/economía , Investigación/tendencias , Piel/patología , Lesión por Inhalación de Humo/patología , Lesión por Inhalación de Humo/fisiopatología , Especificidad de la Especie , Porcinos , Cicatrización de Heridas/fisiología
3.
Int J Obes (Lond) ; 36(4): 485-90, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22143622

RESUMEN

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.


Asunto(s)
Quemaduras/complicaciones , Insuficiencia Multiorgánica/etiología , Obesidad/complicaciones , Sepsis/etiología , Índice de Masa Corporal , Densidad Ósea , Quemaduras/metabolismo , Quemaduras/mortalidad , Proteína C-Reactiva/metabolismo , Niño , Femenino , Humanos , Masculino , Insuficiencia Multiorgánica/metabolismo , Insuficiencia Multiorgánica/mortalidad , Obesidad/metabolismo , Obesidad/mortalidad , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Factores de Riesgo , Sepsis/metabolismo , Sepsis/mortalidad , Síndrome de Respuesta Inflamatoria Sistémica/etiología , Triglicéridos/sangre
4.
Gene Ther ; 17(6): 770-8, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20376099

RESUMEN

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 cm(2) 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 beta-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 beta-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.


Asunto(s)
Quemaduras/terapia , Técnicas de Transferencia de Gen , Liposomas , Factor de Crecimiento Derivado de Plaquetas/genética , Trasplante de Piel/métodos , Piel/lesiones , Animales , Epidermis , Femenino , Modelos Animales , Regeneración , Porcinos , Transfección , Cicatrización de Heridas/genética
5.
Gene Ther ; 14(16): 1235-42, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17538636

RESUMEN

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-beta 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.


Asunto(s)
ADN Complementario/administración & dosificación , Factor 7 de Crecimiento de Fibroblastos/genética , Terapia Genética/métodos , Factor I del Crecimiento Similar a la Insulina/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Cicatrización de Heridas , Animales , Colágeno Tipo I/metabolismo , Colágeno Tipo III/metabolismo , Colágeno Tipo IV/metabolismo , Dermis/citología , Dermis/metabolismo , Células Epidérmicas , Epidermis/metabolismo , Factores de Crecimiento de Fibroblastos/metabolismo , Regulación de la Expresión Génica , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Liposomas , Masculino , Neovascularización Fisiológica , Factor de Crecimiento Derivado de Plaquetas/metabolismo , Ratas , Ratas Sprague-Dawley , Factor de Crecimiento Transformador beta/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética
6.
Novartis Found Symp ; 280: 238-48; discussion 248-51, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17380798

RESUMEN

A significant proportion of the mortality and morbidity of severe burns is attributable to the ensuing hypermetabolic response that typically lasts for at least 9-12 months post-injury. This is associated with impaired wound healing, increased infection risks, erosion of lean body mass, hampered rehabilitation and delayed reintegration of burn survivors into society. The endocrine status is markedly altered during this period with an initial and then sustained increase in proinflammatory 'stress' hormones such as cortisol and other glucocorticoids, and catecholamines including epinephrine and norepinephrine by the adrenal medulla and cortex. These hormones exert catabolic effects leading to muscle wasting, the intensity of which depends upon the percentage of total body surface area (TBSA) involved, as well as the time elapsed since initial injury. Pharmacological and non-pharmacological strategies may be used to reverse the catabolic effect of thermal injury. Of these, beta-adrenergic blockade with propranolol has been the most efficacious anti-catabolic therapy in the treatment of burns. The underlying mechanism of action of propranolol is still unclear, however its effect appears to occur due to an increased protein synthesis in the face of a persistent protein breakdown and reduced peripheral lipolysis. This article aims to review the current understanding of catecholamines in postburn muscle wasting and focuses on the clinical and metabolic effects of beta-blockade in severe burns.


Asunto(s)
Antagonistas Adrenérgicos beta/uso terapéutico , Quemaduras/tratamiento farmacológico , Propranolol/uso terapéutico , Animales , Humanos
7.
Gene Ther ; 14(1): 1-10, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16929353

RESUMEN

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.


Asunto(s)
Terapia Genética/métodos , Péptidos y Proteínas de Señalización Intercelular/genética , Cicatrización de Heridas , Heridas y Lesiones/terapia , Animales , Quemaduras/metabolismo , Quemaduras/terapia , ADN/administración & dosificación , Electroporación , Terapia Genética/tendencias , Vectores Genéticos/administración & dosificación , Humanos , Péptidos y Proteínas de Señalización Intercelular/fisiología , Liposomas/administración & dosificación , Piel/lesiones , Piel/metabolismo , Transfección/métodos , Virus/genética , Cicatrización de Heridas/genética , Heridas y Lesiones/metabolismo
8.
Gene Ther ; 12(23): 1718-24, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16034455

RESUMEN

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.


Asunto(s)
Colesterol/administración & dosificación , Terapia Genética/métodos , Sustancias de Crecimiento/genética , Liposomas/administración & dosificación , Cicatrización de Heridas , Heridas y Lesiones/terapia , Animales , Apoptosis , Proliferación Celular , Colágeno/análisis , Colágeno/metabolismo , Células Epiteliales/metabolismo , Ácidos Grasos Monoinsaturados/administración & dosificación , Ácidos Grasos Monoinsaturados/química , Factor 7 de Crecimiento de Fibroblastos/análisis , Técnicas de Transferencia de Gen , Sustancias de Crecimiento/metabolismo , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/análisis , Factor I del Crecimiento Similar a la Insulina/análisis , Lípidos/administración & dosificación , Lípidos/química , Liposomas/química , Masculino , Peso Molecular , Neovascularización Fisiológica , Factor de Crecimiento Derivado de Plaquetas/análisis , Conformación Proteica , Compuestos de Amonio Cuaternario/administración & dosificación , Compuestos de Amonio Cuaternario/química , Ratas , Ratas Sprague-Dawley , Factor A de Crecimiento Endotelial Vascular/análisis , Heridas y Lesiones/metabolismo
10.
Zentralbl Chir ; 129 Suppl 1: S129-32, 2004 May.
Artículo en Alemán | MEDLINE | ID: mdl-15168310

RESUMEN

In 1920 Braun described a technique of skin grafting particularly designed for areas where shearing forces, high pressure and extensive secretion cause repetitive loss of conventionally transplanted skin. During the last 10 years we successfully used this technique when impaired wound healing was encountered due to various reasons. Clinical examples of application and results are presented. By combining this technique with vacuum therapy, formation of granulation tissue can be accelerated, thereby resulting in successful transplantation of problematic and therapy resistant wounds.


Asunto(s)
Desbridamiento/instrumentación , Apósitos Oclusivos , Trasplante de Piel/instrumentación , Técnicas de Sutura/instrumentación , Heridas y Lesiones/cirugía , Adulto , Anciano , Quemaduras/cirugía , Pie Diabético/cirugía , Diseño de Equipo , Femenino , Estudios de Seguimiento , Humanos , Úlcera de la Pierna/cirugía , Masculino , Microcomputadores , Persona de Mediana Edad , Úlcera por Presión/cirugía , Reoperación/instrumentación , Cirugía Asistida por Computador/instrumentación , Vacio , Úlcera Varicosa/cirugía , Cicatrización de Heridas/fisiología
11.
J Surg Res ; 117(2): 202-7, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15047124

RESUMEN

BACKGROUND: The purpose of the current study was to characterize and compare an autologous thrombocyte gel containing several blood components with a commercially available glue. MATERIALS AND METHODS: Twenty-five volunteers had blood drawn, and lab values, characteristics of the platelet-enriched plasma (PRP), thrombocyte aggregation, electron microscopic examinations, and the breaking strength were determined and compared to a commercial glue. RESULTS: Overall 65% of the total thrombocytes could be isolated from the volunteers and an enrichment of 300% with an autotransfusion device could be achieved. Thrombocyte aggregation as a marker for thrombocyte function decreased from 92% in patients to 71% in the PRP. The autologous glue demonstrated a significant reduced breaking strength (0,76 N/cm(3)) compared to the commercial glue (7.42 N/cm(2)), P < 0.05. The decrease in breaking strength could be correlated with the thrombocyte concentration, P < 0.05. CONCLUSIONS: In the present study we have shown that an autologous platelet-enriched plasma cannot be used as a glue in the common sense to seal stitches or prosthesis. Platelet gels, however, have a high concentration of platelets that release the bioactive proteins and growth factors are necessary to initiate and accelerate tissue repair and enhance dermal and epidermal regeneration. To evaluate the possible clinical implication prospective, randomized studies should be performed to examine the effect of autologous plasma platelet-enriched plasma on wound healing.


Asunto(s)
Plaquetas , Transfusión de Sangre Autóloga , Adhesivo de Tejido de Fibrina/química , Adhesivo de Tejido de Fibrina/farmacología , Separación Celular , Fibrina/ultraestructura , Geles , Humanos , Microscopía Electrónica , Agregación Plaquetaria/efectos de los fármacos , Recuento de Plaquetas , Resistencia a la Tracción
12.
Gene Ther ; 11(10): 847-55, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-14961069

RESUMEN

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 microg, vehicle), or liposomes plus the insulin like-growth factor-I (IGF-I)cDNA (2.2 microg) and Lac Z gene (0.22 microg), or liposomes plus the keratinocyte growth factor (KGF) cDNA (2.2 microg) and Lac Z gene (0.22 microg), or liposomes plus the IGF-I/KGF cDNA (2.2 microg) and Lac Z gene (0.22 microg). 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.


Asunto(s)
Técnicas de Transferencia de Gen , Sustancias de Crecimiento/genética , Piel/lesiones , Animales , Apoptosis/genética , División Celular/genética , Colágeno/metabolismo , ADN Complementario/genética , Células Epiteliales/patología , Estudios de Factibilidad , Sustancias de Crecimiento/metabolismo , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/genética , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Liposomas , Masculino , Neovascularización Fisiológica , Ratas , Ratas Sprague-Dawley , Piel/irrigación sanguínea , Piel/metabolismo , Piel/patología , Transfección , Cicatrización de Heridas , beta-Galactosidasa/genética
14.
Gene Ther ; 9(16): 1065-74, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12140734

RESUMEN

Keratinocyte growth factor (KGF) stimulates epithelial cell differentiation and proliferation, which are of major importance for wound healing. Local protein administration, however, has been shown to be ineffective due to enzymes and proteases in the wound fluid. We hypothesized that delivering KGF as a non-viral liposomal cDNA gene complex is a new approach that would effectively enhance dermal and epidermal regeneration. Twenty-two rats were given an acute wound and divided into two groups to receive weekly subcutaneous injections of liposomes plus the LacZ gene (0.2 microg, vehicle), or liposomes plus the KGF cDNA (2.2 microg) and LacZ cDNA (0.2 microg). Transfection was confirmed by histochemical assays for beta-galactosidase. Planimetry, histological and immunohistochemical techniques were used to determine protein expression, dermal and epidermal regeneration. Transfection and subsequent KGF expression was found in diving cells in the granulation tissue. Epidermal regeneration was improved by 170% in rats receiving the KGF cDNA constructs by exhibiting the most rapid area and linear wound re-epithelialization, P < 0.0001. KGF improved epidermal cell net balance by increasing skin cell proliferation and decreasing skin cell apoptosis, P < 0.0001. Dermal regeneration was further improved in KGF cDNA treated animals by an increased collagen deposition and morphology, P < 0.0001. KGF cDNA increased neo-vascularization and concomitant VEGF concentrations when compared with vehicle, P < 0.01. KGF cDNA did not only stimulate epithelial cells, but also mesenchymal cells through increases in IGF-I concentration, P < 0.005. Liposomes containing the KGF cDNA gene constructs were effective in improving epidermal and dermal regeneration. KGF gene transfer to acute wounds may represent a new therapeutic strategy to enhance wound healing.


Asunto(s)
Quemaduras/terapia , Factores de Crecimiento de Fibroblastos/genética , Técnicas de Transferencia de Gen , Terapia Genética/métodos , Cicatrización de Heridas , Animales , Apoptosis , Quemaduras/metabolismo , Quemaduras/patología , División Celular , Colágeno/metabolismo , ADN Complementario/administración & dosificación , Epidermis/fisiología , Factor 7 de Crecimiento de Fibroblastos , Factores de Crecimiento de Fibroblastos/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Liposomas , Masculino , Ratas , Ratas Sprague-Dawley , Regeneración , Piel/patología , Fenómenos Fisiológicos de la Piel , Transfección
15.
Arch Surg ; 136(11): 1301-6, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11695977

RESUMEN

HYPOTHESIS: Characteristic of the hypermetabolic response to a thermal injury is the massive protein catabolism and compromised structure and function of essential organs. Nutrition has been suggested to affect protein metabolism and clinical outcome after a severe injury but published studies show controversial data. The purpose of this study was to determine the effect of enriched nutritional support during the postburn hypermetabolic state on protein metabolism in serum, liver, muscle, and skin. SETTING: Laboratory. INTERVENTION: Twenty-two rats were given burns covering 60% of their total body surface area and randomized to receive either standard rat chow (control) or a diet high in vitamins, protein, amino acids, and omega3 fatty acids. MAIN OUTCOME MEASURES: Five weeks after injury, body weight, serum, muscle, and hepatic protein content, insulin-like growth factor I concentration, and wound healing (reepithelization) were determined. RESULTS: Rats receiving the enriched diet showed a gradual improvement in body weight 1, 2, 3, 4, and 5 weeks postburn compared with controls (P< .001). Diet-fed rats demonstrated higher protein and insulin-like growth factor 1 content in serum, muscle, and liver 5 weeks after trauma (P< .001). Serum protein, albumin, and transferrin levels were significantly increased in rats receiving the diet compared with control rats (P< .001). Reepithelization was accelerated in rats receiving the enriched diet 4 (diet-fed, mean +/- SD, 23% +/- 1% vs controls, 17% +/- 1%; P< .001) and 5 (diet-fed, 24% +/- 1% vs controls, 18% +/- 1%; P< .001) weeks postburn compared with control rats. CONCLUSIONS: Nutritional intervention high in protein, vitamins, amino acids, and omega3 fatty acids improves protein net balance during the hypermetabolic response to thermal injury. Compromised organ function and structure and clinical outcome during the hypermetabolic response may be improved.


Asunto(s)
Quemaduras/metabolismo , Quemaduras/terapia , Alimentos Fortificados , Fenómenos Fisiológicos de la Nutrición , Proteínas/metabolismo , Animales , Factor I del Crecimiento Similar a la Insulina/análisis , Hígado/química , Masculino , Músculo Esquelético/química , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Cicatrización de Heridas
16.
Shock ; 16(5): 373-9, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11699076

RESUMEN

After a severe trauma, such as a cutaneous thermal injury, an increase in hepatocyte apoptosis has been associated with hepatocyte damage and impairment in hepatic function. Insulinlike growth factor-I (IGF-I) exerts antiapoptotic effects in several organs, thus improving organ homeostasis. The purpose of the present study was to determine whether IGF-I in combination with its principle binding protein-3 (BP-3) attenuates liver damage after a burn and whether this attenuation is through signals of the apoptotic-proliferative axis of hepatocytes. Sprague-Dawley rats (56 males) received a 60% total body surface area third-degree scald burn and were randomly divided to receive either rhlGF-I/BP3 (10 mg/kg/day s.c.) or saline (control). Serum aspartate transaminase (AST) and nitric oxide (NO), and hepatocyte proliferation and apoptosis, were measured on postburn days 1, 2, 5, and 7. Hepatic interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) mRNA and hepatic nuclear-factor kappa B (NF-kappa B) were determined at 1 and 2 days postburn. IGF-I/BP-3 decreased serum AST and increased serum NO at 1, 2, and 5 days after burn when compared with controls (P < 0.05). IGF-I/BP-3 increased hepatocyte proliferation on the first day after burn and decreased hepatocyte apoptosis at day 7 postburn when compared with controls (P < 0.05). IGF-I/BP-3 decreased hepatic IL-1 beta and TNF-alpha mRNA 1 day after burn (P < 0.05). IGF-I/BP-3 further increased hepatic NF-kappa B concentration 1 and 2 days postburn when compared with controls (P < 0.05). Recombinant hIGF-I in combination with its principle binding protein conserves hepatic homeostasis, which is associated with a transient increase in hepatocyte proliferation and decrease in hepatocyte apoptosis possibly through NO and hepatic NF-kappa B.


Asunto(s)
Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/farmacología , Factor I del Crecimiento Similar a la Insulina/farmacología , Hígado/lesiones , Hígado/metabolismo , Heridas y Lesiones/metabolismo , Animales , Apoptosis , Aspartato Aminotransferasas , Quemaduras/patología , Quemaduras/fisiopatología , División Celular/efectos de los fármacos , Hepatocitos/patología , Homeostasis/efectos de los fármacos , Etiquetado Corte-Fin in Situ , Hígado/patología , Masculino , FN-kappa B/metabolismo , Óxido Nítrico/sangre , Ratas , Ratas Sprague-Dawley
17.
Shock ; 16(5): 380-2, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11699077

RESUMEN

A severe thermal injury is commonly associated with immune suppression and increased susceptibility to sepsis, frequently leading to multiple organ failure. Transforming growth factor-beta (TGF-beta) is a potent immunosuppressive cytokine involved in complications associated with major trauma. Interleukin- 4 (IL-4) is thought to synergize the immunosuppressive activity of TGF-beta by promoting naive lymphocytes to differentiate and generate TGF-beta secreting cells. This study examines the alterations in serum levels of TGF-beta and IL-4 after a thermal injury. Male Sprague-Dawley rats (300-400 g) were anesthetized and received a 50% total body surface area full-thickness scald burn followed by fluid resuscitation and analgesia. Control rats were given the same treatment, but were immersed in water at room temperature. Rats were sacrificed from 1 h to 8 days after injury. Blood samples were collected aseptically from the inferior caval vein. Serum levels of TGF-beta and IL-4 were measured by enzyme linked immunosorbent assay. Rats in the control and thermal injury groups showed similar increases in serum TGF-beta 1 h after injury. A progressive increase in serum TGF-beta was observed in burned animals compared to control animals starting on day 3 and continued through day 8 (P < 0.01). Serum IL-4 levels in control and thermally injured animals remained undetectable (< 15.6 pg/mL) throughout the experiment. Thermal injury induces a significant increase in serum TGF-beta, which may contribute to post-burn immunosuppression with an increased susceptibility to sepsis.


Asunto(s)
Quemaduras/sangre , Factor de Crecimiento Transformador beta/sangre , Animales , Biomarcadores/sangre , Ensayo de Inmunoadsorción Enzimática , Masculino , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
18.
J Trauma ; 51(4): 736-9, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11586168

RESUMEN

BACKGROUND: Trauma induces hypermetabolic responses that are characterized by the mobilization of all available substrates. The marked increase of peripheral lipolysis after a burn can lead to the development of fatty liver, which has been associated with immunodepression and increased mortality. METHODS: All autopsies of pediatric burn patients between January 1988 and January 1998 were reviewed. Patient demographics, hospital course, cause of death, and hepatic and septic macroscopic and microscopic findings were recorded. RESULTS: Thirty-seven pediatric patients (4 +/- 1 years old) were included in the study. The mean burn size was 69% +/- 5% total body surface area burned. Eighty percent of the patients presented with fatty infiltration of the liver. Liver weight/body weight ratio was 77 +/- 5 gm/kg, representing 2.1 times the liver weight of age- and sex-matched controls (p < 0.001). Patients with severe fatty infiltration of the liver had a higher incidence of sepsis (p < 0.001). CONCLUSION: Fatty infiltration of the liver is a common condition in fatal burns. Severe fatty infiltration of the liver is associated with an increased incidence of sepsis, although a causative effect could not be found. It is notable that fatty infiltration of the liver occurred in the complete absence of parenteral nutrition.


Asunto(s)
Quemaduras/complicaciones , Hígado Graso/epidemiología , Hígado Graso/patología , Preescolar , Hígado Graso/etiología , Femenino , Humanos , Incidencia , Modelos Lineales , Masculino , Necrosis , Factores de Riesgo , Sepsis/epidemiología , Texas/epidemiología , Factores de Tiempo
19.
Burns ; 27(5): 439-45, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11451595

RESUMEN

Infection is still one of the leading causes of morbidity and mortality in severely burned patients. Evidence suggests that many of the responsible organisms are endogenous. Systemic antibiotic prophylaxis is not effective, and produces resistant strains of microorganisms. SDD has been postulated to be beneficial for controlling and decreasing infections in critically ill patients. Its efficacy in severely burned patients, however, remains controversial. In order to analyze the efficacy of selective decontamination of the digestive (SDD) tract, to decrease the bacterial colonization of the aerodigestive tract and burn wounds, and the incidence of septic complications in severely burned children, 23 pediatric patients affected of severe burns were prospectively randomized in a double-blinded study. Eleven patients received SDD (Polymyxin E, Tobramycin, and Amphotericin B), and 12 placebo. Demographics, hospital course, microbiology results, complications, infectious episodes, and serum levels of IL-1beta, IL-6, IL-10, and TNF-alpha were compared to determine the efficacy of SDD. Colonization rates to the wound, sputum, nasogastric aspirates, and feces were similar. Pneumonia, sepsis and other complications had similar incidence in both groups. Serum levels of all cytokines studied were also comparable, suggesting a similar inflammatory status in all patients, regardless of the treatment received. Patients in the SDD group, however, had a significantly higher incidence of diarrhea (P=0.003). We can conclude that selective decontamination of the digestive tract with Polymixin E, Tobramycin and Amphotericin B is not effective to decrease bacterial colonization and infectious episodes in severely burned pediatric patients.


Asunto(s)
Bacteriemia/tratamiento farmacológico , Quemaduras/complicaciones , Enfermedades del Sistema Digestivo/tratamiento farmacológico , Enfermedades del Sistema Digestivo/microbiología , Quimioterapia Combinada/uso terapéutico , Anfotericina B/administración & dosificación , Análisis de Varianza , Bacteriemia/mortalidad , Bacteriemia/prevención & control , Quemaduras/diagnóstico , Quemaduras/mortalidad , Niño , Infección Hospitalaria/prevención & control , Citocinas/análisis , Citocinas/efectos de los fármacos , Enfermedades del Sistema Digestivo/prevención & control , Método Doble Ciego , Ensayo de Inmunoadsorción Enzimática , Femenino , Estudios de Seguimiento , Humanos , Puntaje de Gravedad del Traumatismo , Intubación Gastrointestinal , Modelos Lineales , Masculino , Polimixinas/administración & dosificación , Probabilidad , Estudios Prospectivos , Valores de Referencia , Tasa de Supervivencia , Tobramicina/administración & dosificación , Resultado del Tratamiento
20.
Burns ; 27(5): 447-52, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11451596

RESUMEN

Delays in growth are commonly observed in children who have sustained a severe cutaneous burn. The reasons for this growth delay are not completely known, but in adults, plasma growth hormone (GH) levels have been shown to decrease after thermal injury. If this is also the case in severely burned children, the low GH levels may contribute to their chronic growth delay. We propose that treatment with rhGH may prevent this burn-induced growth delay. Height velocities were measured for up to 2 years after injury in 38 burned children (age 7+/-1 years) with a 64+/-2% total burn surface area (TBSA) burn and a 59+/-3% third-degree burn who received 0.2 mg/kg/day rhGH during hospitalization. These height velocities were compared to 41 burned children (age 8+/-1 years) with a 64+/-3% TBSA burn and a 60+/-3% TBSA third-degree burn who were treated similarly but did not receive rhGH. Height velocities and height percentiles were compared to standard height velocity and percentile nomograms of unburned children. To determine the effect of rhGH on energy requirements, resting energy expenditures (REE) were measured by indirect calorimetry and compared to values calculated from the Harris-Benedict equation. All data are presented as mean+/-S.E.M. No differences in average height percentile could be shown between those receiving GH and controls at admission and 6 months after burn. There was, however, a significant difference (P<0.05) in height velocity during the first 2 years after burn between GH (47th+/-6 percentile) and controls (32nd+/-5 percentile). For rhGH-treated children, the REE was elevated by 34+/-4% versus 35+/-5% for controls. Recombinant human GH, given during acute hospitalization, maintained growth in severely burned children who would otherwise experience a significant growth delay. Treatment with rhGH did not atttenuate their elevated REE.


Asunto(s)
Estatura/efectos de los fármacos , Quemaduras/tratamiento farmacológico , Quemaduras/fisiopatología , Metabolismo Energético/efectos de los fármacos , Hormona de Crecimiento Humana/administración & dosificación , Adolescente , Quemaduras/diagnóstico , Niño , Desarrollo Infantil/fisiología , Preescolar , Esquema de Medicación , Femenino , Estudios de Seguimiento , Humanos , Inyecciones Subcutáneas , Puntaje de Gravedad del Traumatismo , Masculino , Probabilidad , Valores de Referencia , Estadísticas no Paramétricas , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA