Gene expression profiles of giant hairy naevi

BACKGROUND

Congenital neomelanocytic naevi appear in nearly 1% of newborns. Giant hairy naevi (GHN) are uncommon lesions covering large areas of the body. They are of concern because they have the potential to transform into malignant melanomas.

AIMS

To describe gene expression profiles of GHN and nearby normal skin from patients with GHN and normal control skin (from patients with cleft lip/palate).

METHODS

Tissues from three patients with GHN and two normal controls were studied for differences in gene expression profiles. Total RNA was isolated from normal skin near the hairy naevus, GHN, and skin from normal controls. The RNA samples were subjected to probe labelling, hybridisation to chips, and image acquisition according to the standard Affymetrix protocol.

RESULTS

There were 227 genes affected across all samples, as determined by DNA microarray analysis. There was increased expression of 22 genes in GHN compared with nearby normal skin. Decreased expression was noted in 73 genes. In addition, there was increased expression of 36 genes in normal skin near GHN compared with normal control skin, and decreased expression of five genes. Categories of genes affected were those encoding structural proteins, proteins related to developmental processes, cell death associated proteins, transcription factors, growth factors, stress response modulators, and collagen associated proteins. Changes in mRNA expression were checked by reverse transcription polymerase chain reaction.

CONCLUSIONS

Genetic profiles of GHN may provide insight into their pathogenesis, including their potential for malignant transformation. Such information may be useful in improving the understanding and management of these lesions.

Increased liver weights in severely burned children: comparison of ultrasound and autopsy measurements

Hepatomegaly is a common finding at autopsy in severely burned children surviving less than 6 months. This study validates a reliable ultrasound method which can be used to identify changes in liver size in severely burned children during acute hospitalization. Thirty-eight children, age 0.5-17 years with burns covering over 40% of their total surface area were studied at autopsy. Liver weight was measured at autopsy and compared to predicted liver weight for age and height. Eighteen had liver size measured by ultrasound within 10 days of death while five had ultrasound liver measures after death just prior to autopsy. All burned children who survived 7 days or more (n = 33) had liver weights at autopsy that were greater than predicted for age and height while all 23 livers measured by ultrasound were greater than predicted. Autopsy weights correlated well with weights estimated by ultrasound, R = 0.824. At autopsy, those who survived 7 days or more had enlarged livers ranging from 142 to 406% of their predicted normal age and height. Common histologic findings include large and small-droplet fat deposits, and cholestasis. The degree of these histologic abnormalities correlated with the increase in liver weight, R = 0.652. Ultrasound is a valid, noninvasive method for measuring liver weight changes in severely burned children during acute hospitalization. Ninety-five percent of the severely burned children from this institute had significant hepatomegaly identified at autopsy.

IGF-I/BP-3 administration preserves hepatic homeostasis after thermal injury which is associated with increases in no and hepatic NF-kappa B

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.

Serum TGF-beta in thermally injured rats

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.

Nutritional intervention high in vitamins, protein, amino acids, and omega3 fatty acids improves protein metabolism during the hypermetabolic state after thermal injury

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.

Possibilities of non-viral gene transfer to improve cutaneous wound healing

Enhancement of dermal and epidermal regeneration represents a crucial goal for the treatment of acute, e.g. burn and trauma wounds, and chronic wounds, e.g. diabetic, autoimmune, arterial and venous wounds. Studies defining molecular mechanisms of the complex cascade of wound healing have shown that growth factors represent a new therapeutic strategy. The clinical application of growth factors in the form of proteins has been shown to be of little benefit. Therefore new delivery systems and therapeutic strategies needed to be developed to improve dermal and epidermal regeneration, one of which is gene therapy. For successful gene delivery the selection of an appropriate vector has been shown to be paramount. Because Retroviruses, Adenoviruses and Adeno-Associated Viruses can cause immunologic reactions and mutations, non-viral delivery systems for gene therapy, such as liposomal gene transfer appear advantageous over viral gene therapy. This review discusses the success, potential and limitations of non-viral gene transfer to improve regeneration of dermal and epidermal structures.

Liposomal IGF-1 gene transfer modulates pro- and anti-inflammatory cytokine mRNA expression in the burn wound

The use of systemic IGF-1 has been shown to attenuate the postburn hypermetabolic response and improve burn wound healing. Local IGF-1 gene therapy, however, promotes re-epithelialization in the burn wound without the side-effects associated with systemic delivery. We tested the hypothesis that these beneficial effects are due to changes in local cytokine production. Adult male Sprague-Dawley rats received a 40% total body surface area full-thickness scald burn and randomly received a subcutaneous injection at the burn wound margin of saline or cationic liposomes containing a IGF-1 cDNA construct. Animals were killed at 1, 4, 7 and 10 days after burn trauma. Skin biopsies at the wound border were harvested for total RNA extraction. Cytokine mRNA expression was determined using a multi-probe RNase protection assay. Data are presented as means +/- s.e.m. Statistical analysis used the unpaired t-test or Mann-Whitney test where appropriate. Significance was accepted at P < 0.05. Treatment of the burn wound with liposomal IGF-1-cDNA transfer decreased IL-1beta mRNA levels on day 10 after burn trauma from five-fold burn-induced increases compared with sham-treated rats, to near the control values present in unburned skin samples. Similarly, there was an eight-fold increase in TNF-alpha mRNA expression on postburn day 10 that was abrogated by IGF-1 gene therapy. Local IGF-1 gene transfer attenuates the mRNA expression of the inflammatory cytokines IL-1beta and TNF-alpha in the burn wound. This change may improve burn wound healing by decreasing prolonged local inflammation.

The effect of short-term growth hormone treatment on growth and energy expenditure in burned children

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.

Effect of varying burn sizes and ambient temperature on the hypermetabolic rate in thermally injured rats

BACKGROUND

Small animals with scald covering 50% of their total body surface area (TBSA) have been used to study the hypermetabolic burn response. In the 50% TBSA burn rat model, the area of normal skin that is available for animal instrumentation is restricted and the mortality rate has been high. The purpose of this study was to determine whether a smaller burn size can induce a similar hypermetabolic response with mortality rates lower than those of the 50% TBSA model.

METHODS

Rats were randomly divided into four groups to receive a 0% (sham nonburned), 30%, 40%, or 50% TBSA third-degree scald burn. The hypermetabolic response was determined by measuring changes in body weight and oxygen consumption at ambient temperatures of 21, 26, and 31 degrees C for each burn size. Weight measurements were made daily while oxygen consumption was measured 7, 11, and 14 days after thermal injury.

RESULTS

All thermally injured rats lost body weight; however, there were no significant differences between the 30, 40, and 50% TBSA burn groups. Burn induced a hypermetabolic response as indicated by an increase in oxygen consumption from 130 to 200% that of sham nonburned rats. No significant difference in oxygen consumption could be shown over the study period between the three burn sizes at different ambient temperatures. Mortality was 0% in the sham and 30% group, 10% for the 40% group, and 50% for the 50% TBSA burn group.

CONCLUSIONS

From our study we conclude that a burn size covering 30% of the TBSA induces the same hypermetabolic response as a 50% TBSA burn.

Surfactant phosphatidylcholine in thermally injured pigs

OBJECTIVE

To investigate the effect of a thermal injury on pulmonary surfactant phosphatidylcholine kinetics.

DESIGN

Random, controlled study.

SETTING

University research laboratory.

SUBJECTS

Yorkshire swine (n = 8) with and without a 40% total body surface area burn.

INTERVENTIONS

A new isotope tracer methodology was used to quantify surfactant phosphatidylcholine kinetics. Four days after burn, [1,2-13C2]acetate and [U-(13)C16]palmitate were infused continuously for 8 hrs to quantify surfactant phosphatidylcholine synthesis, secretion, recycling, and irreversible loss.

MEASUREMENTS AND MAIN RESULTS

The total surfactant phosphatidylcholine pool size was reduced from the control value of 2.65 +/- 0.05 to 1.61 +/- 0.08 micromol/g wet lung in burned animals (p <.05), as was the proportional contribution of palmitate to lung surfactant phosphatidylcholine composition. This reduction was associated with a significant decrease in lung dynamic compliance from the control value of 66 +/- 6 to 55 +/- 6 mL/cm H2O for burned pigs (p <.05). The most prominent response of lung phosphatidylcholine kinetics was a decrease in the total lung phosphatidylcholine synthesis from a control value of 12.7 +/- 1.2 to 5.5 +/- 0.3 nmol phosphatidylcholine-bound palmitate x hr(-1) x g of wet lung(-1) in burned animals (p<.05).

CONCLUSIONS

Pulmonary phosphatidylcholine content and palmitate composition decrease after burn injury because of a decrease in the rate of phosphatidylcholine synthesis. These responses likely contribute to impaired lung compliance.

Cell proliferation, apoptosis, NF-kappaB expression, enzyme, protein, and weight changes in livers of burned rats

Thermal injury has been shown to alter gut epithelium and heart myocyte homeostasis by inducing programmed cell death. The effect of thermal injury on hepatocyte apoptosis and proliferation, however, has not been established. The purpose of this study was to determine whether a large thermal injury increases liver cell apoptosis and proliferation and whether these changes were associated with alterations in hepatic nuclear factor kappaB (NF-kappaB) expression and changes in liver enzymes and amount of protein. Sprague-Dawley rats received a 40% total body surface area scald burn or sham burn. Rats were killed and livers were harvested at 1, 2, 5, and 7 days after burn. Liver cell apoptosis was determined by terminal deoxyuridine nick end labeling (TUNEL) assay and cell proliferation by immunohistochemistry for proliferating cell nuclear antigen. Hepatic NF-kappaB expression was determined by Western blot, and total hepatic protein content was determined by protein assay. Protein concentration decreased after burn compared with sham controls (P < 0.05). Liver cell apoptosis, proliferation, and NF-kappaB expression in hepatocytes increased in burned rats compared with controls (P < 0.05). It was concluded that thermal injury induces hepatic cell apoptosis and proliferation associated with an increase in hepatic NF-kappaB expression and a decrease in hepatic protein concentration.

Chest radiographic appearances in severely burned adults. A comparison of early radiographic and extravascular lung thermal volume changes

Chest radiographs (CXRs) have previously been used as a diagnostic tool to detect changes in lung water. In this study CXR changes in severely burned adults, in the absence of an inhalation injury, preceded detectable increases in extravascular lung thermal volume (ELTV) by 3 to 5 days. The hypothesis that early CXR density changes in burned patients have an infectious cause, not related to changes in ELTV, was tested. Blood cultures, CXRs, and ELTV were evaluated during the first 15 days after injury in severely burned adults who had no identified inhalation injury. Chest radiographs were scored daily on a 1 to 5 scale, with 1 = normal, 2 = peribronchial cuffing, 3 = mild interstitial infiltrates, 4 = severe interstitial infiltrates, and 5 = alveolar infiltrates. In all patients, except those who were septic, increases in their CXR density scores correlated well with increases in ELTV. The ELTV/CXR score ratios for septic burn patients on days 1 to 6 postburn was 1.7 +/- 0.2 compared with 4.2 +/- 0.4, (means +/- SEM) for nonseptic (P < .001), whereas the ELTV/CXR score ratios for septic and nonseptic patients, 7 to 15 days postburn, were 3.8 +/- 0.4 and 3.4 +/- 0.5, respectively. We suggest that before any measurable change in ELTV early increases in CXR density scores in burned patients without a concomitant inhalation injury are caused by intraalveolar pneumonitis or hyaline membrane atelectasis and not increased ELTV.

Palm computer demonstrates a fast and accurate means of burn data collection

Manual biomedical data collection and entry of the data into a personal computer is time-consuming and can be prone to errors. The purpose of this study was to compare data entry into a hand-held computer versus hand written data followed by entry of the data into a personal computer. A Palm (3Com Palm IIIx, Santa, Clara, Calif) computer with a custom menu-driven program was used for the entry and retrieval of burn-related variables. These variables were also used to create an identical sheet that was filled in by hand. Identical data were retrieved twice from 110 charts 48 hours apart and then used to create an Excel (Microsoft, Redmond, Wash) spreadsheet. One time data were recorded by the Palm entry method, and the other time the data were handwritten. The method of retrieval was alternated between the Palm system and handwritten system every 10 charts. The total time required to log data and to generate an Excel spreadsheet was recorded and used as a study endpoint. The total time for the Palm method of data collection and downloading to a personal computer was 23% faster than hand recording with the personal computer entry method (P < 0.05), and 58% fewer errors were generated with the Palm method.) The Palm is a faster and more accurate means of data collection than a handwritten technique.

Glucose effects on lung surfactant kinetics in conscious pigs

The primary goal of this study was to investigate the effects of glucose infusion on surfactant phosphatidylcholine (PC) metabolic kinetics in the lungs. A new stable isotope tracer model was used in which [1,2-(13)C(2)]acetate and uniformly labeled [U-(13)C(16)]palmitate were infused in 12 normal overnight-fasted pigs to quantify lung surfactant kinetics with or without glucose infusion (24 mg. kg(-1). min(-1)). With glucose infusion, the rate of surfactant PC incorporation from de novo synthesized palmitate increased from the control value of 2.1 +/- 0.2 to 15.5 +/- 1.9 nmol PC-bound palmitate. h(-1). g wet lung(-1) (P < 0.05), whereas the incorporation rate from plasma preformed palmitate decreased from the control value of 20.9 +/- 1.9 to 11.6 +/- 1.1 nmol palmitate. h(-1). g wet lung(-1) (P < 0.05). The palmitate composition in lamellar body surfactant PC increased from the control value of 61.7 +/- 2.1% to 75.9 +/- 0.6% (P < 0.05). The surfactant PC secretion rate decreased from the control value of 239.0 +/- 26.1 to 81.9 +/- 5.3 nmol PC-bound palmitate. h(-1). g wet lung(-1) (P < 0.05). We conclude that, whereas surfactant secretion was inhibited by glucose infusion, neither total surfactant PC synthesis nor the surfactant PC pool size was significantly affected due to an increased reliance on de novo synthesized fatty acids.

Biobrane improves wound healing in burned children without increased risk of infection

A synthetic bilaminar membrane used as a skin substitute (Biobrane) has been shown to decrease pain and hospitalization in superficial second-degree burns. Despite these benefits, it has not been utilized universally, particularly in young children, due to a perceived increase in related infections. We propose that when this synthetic membrane is applied to superficial scald burns <25% of the total body surface area (TBSA), decreased healing times are expected without increased risk of infection. Between 1994-1999, 89 children treated within 48 h after receiving superficial partial thickness scald burns covering 5-25% TBSA with no indication of infection were seen at our hospital. Forty-one were assigned randomly to receive treatment with the skin substitute Biobrane and 48 to receive conservative treatment with topical antimicrobials and dressing changes. Comparisons of treatment were made between groups for length of hospitalization, wound healing times, and infectious complications. Children treated with Biobrane or topical antimicrobials were similar in age, race, sex, %TBSA burned, and location of burn. Those receiving Biobrane had shorter hospitalizations and healing times, which was significant for both infants and toddlers and older children. Treatment groups were not different in the use of systemic antibiotics or readmissions for infectious complications. Biobrane was removed in 5.9% of cases for non-adherence. The application of Biobrane within 48 h of superficial burns provides for shorter hospitalizations and faster healing times in children of all ages without increased risk of infection.

Early fluid resuscitation improves outcomes in severely burned children

BACKGROUND

Recent evidence suggests that timely fluid resuscitation can significantly reduce multiorgan failure and mortality in thermally injured children. In this study, children who received fluid resuscitation within 2 h of a thermal injury were compared with children in which fluid resuscitation was delayed by 2-12 h. We hypothesized that fluid resuscitation given within 2 h of a thermal injury attenuates renal failure, cardiac arrest, cardiac arrest deaths, incidence of sepsis, and overall mortality.

METHODS

A retrospective chart review was made on 133 children admitted to our institute from 1982 to 1999 with scald or flame burns covering more than 50% of their body surface area. Comparisons between early (< 2 h of injury) or delayed (> or = 2 h of injury) fluid resuscitation were made in children experiencing renal failure, sepsis, non-survivors with cardiac arrest requiring pulmonary and advanced life support, and overall mortality. Comparisons were made using the chi2-test with Yates' continuity correction and joint binomial confidence intervals using the Bonferroni correction.

RESULTS

The incidence of sepsis, renal failure, non-survivors with cardiac arrest, and overall mortality was significantly higher in burned children receiving fluid resuscitation that was delayed by 2 h or more compared with those receiving fluid resuscitation within 2 h of thermal injury (P < 0.001).

CONCLUSIONS

Data suggest that fluid resuscitation, given within 2 h of a thermal injury, may be one of the most important steps in the prevention of multi-organ failure and mortality.

Ibuprofen modulates tissue perfusion in partial-thickness burns

INTRODUCTION

The anti-inflammatory and anticoagulant effects of ibuprofen and heparin may enhance skin perfusion in cutaneous scald burns. To test this hypothesis, skin perfusion and edema formation in scald burned rabbit ears were measured.

METHOD

Eighteen rabbits (3.5-4.5 kg) received partial-thickness scald burns to one ear and then were given normal saline, n = 6, 20 mg/kg ibuprofen, n = 6, or 700 IU/kg heparin, n = 6. Skin perfusion, blood flow and edema formation in the burned ear were measured with laser Doppler, ultrasound flowmeter and skin calipers, respectively. Statistical analysis was performed using repeated measures ANOVA with post hoc Scheffe's test for comparison between groups.

RESULTS

Blood flow to the scald burned ear increased 10-15 times that of baseline with tissue perfusion increasing by 70% within 0.5 h compared to pre-burn. Ibuprofen maintained the elevated tissue perfusion for 5 h while the heparin and saline groups showed decreases to 95 and 35% of pre-burn values, respectively. The heparin and ibuprofen groups demonstrated significant increases in ear perfusion at 4 and 5 h postburn. Ibuprofen also showed a significant difference within the first hour postburn, p<0.01. Wet to dry weight ratios in burned ear tissue were greater in rabbits receiving saline or heparin compared to ibuprofen at 3.6+/-0.2 and 2.9+/-0.3 vs. 2.1+/-0.1, respectively (p<0.001).

CONCLUSION

Ibuprofen increases tissue perfusion and reduces edema formation in scald burned rabbit ears.

Recombinant human growth hormone treatment in pediatric burn patients and its role during the hepatic acute phase response

OBJECTIVE

Recombinant human growth hormone (rHGH) has been shown to increase mortality in adult trauma patients; however, little has been reported on its side effects in children. The acute phase response has been suggested to be a contributing factor to trauma mortality. Therefore, the purpose of this study was to examine the effects of exogenous rHGH on the acute phase response in pediatric bum patients.

DESIGN

Prospective, randomized, double-blind study.

SETTING

Shriners Hospital for Children.

PATIENTS

Thermally injured pediatric patients, ranging in age from 0.1 to 16 yrs.

INTERVENTIONS

Twenty-eight thermally injured children received either 0.2 mg/kg/day of rHGH or saline (placebo) within 3 days of admission and for at least 25 days.

MEASUREMENTS AND MAIN RESULTS

Measurements were patient demographics, incidence of sepsis, inhalation injury, mortality, serum constitutive proteins, acute phase proteins, proinflammatory cytokines and insulin-like growth factor-I (IGF-I), insulin-like growth factor binding protein (IGFBP)-1, and IGFBP-3. No differences could be demonstrated in age, gender, burn size, incidence in sepsis (20% vs. 26%), inhalation injury (46% vs. 27%), or mortality (8% vs. 7%) between those receiving rHGH or placebo. Serum IGF-I and IGFBP-3 increased with rHGH treatment, whereas serum IGFBP-1 decreased compared with placebo (p < .05). Burned children treated with rHGH required significantly less albumin substitution to maintain normal levels compared with placebo (p < .05). Those receiving rHGH demonstrated a decrease in serum C-reactive protein and serum amyloid-A and an increase in serum retinol-binding protein compared with placebo (p < .05). rHGH decreased serum tumor necrosis factor-alpha and interleukin (IL)-1beta, whereas no changes were found for serum IL-1alpha, IL-6, and IL-10 compared with placebo (p < .05). Free fatty acids were elevated in burned children who received rHGH (p < .05).

CONCLUSION

Data indicate that rHGH does not increase mortality. rHGH decreased acute phase proteins, tumor necrosis factor-alpha, and IL-1beta, which is associated with increases in constitutive hepatic proteins and IGF-I.

Early release of third-degree eyelid burns prevents eye injury

Burns to the eyelids occur in more than 20 percent of flame injuries and can lead to ocular damage and even blindness. Burn wound contracture can cause ectropion of the eyelid, resulting in exposure keratitis, corneal ulcers, and conjunctivitis. At our hospital, early eyelid release and grafting has made a significant difference in the long-term outcomes of third-degree eyelid burns; however, the question of just how early eyelid release and grafting should take place is an unresolved issue. Fifty-seven children with third-degree eyelid burns were reviewed; 17 had eyelid release within 7 days of receiving eyelid burns and 40 had a delay in eyelid release of more than 7 days after injury. Analysis was by chi-square with the Yates continuity correction or Fisher's exact test when appropriate. Corneal ulcers developed in 2 of 17 of the early eyelid release of third-degree burns, compared with 25 of 40 delayed releases (p = 0.001), exposure keratitis in 3 of 17 early releases, and 30 of 40 in delayed release (p = 0.000); conjunctivitis was identified in 1 of 17 early releases and 14 of 40 delayed eyelid releases (p = 0.025). Release of eyelid burns within 7 days of injury can prevent the development of exposure keratitis, progressive conjunctivitis, corneal ulceration, and the need for corneal surgery. We suggest that early release and grafting should be the treatment of choice for children and young adults with third-degree burns to the eyelids.

Insulin-like growth factor I in combination with insulin-like growth factor binding protein 3 affects the hepatic acute phase response and hepatic morphology in thermally injured rats

OBJECTIVE

To modulate the hepatic acute phase response after a thermal injury by the administration of insulin-like growth factor I (IGF-I) in combination with its principal binding protein 3 (IGFBP-3).

SUMMARY BACKGROUND DATA

The hepatic acute phase response is a cascade of events initiated to restore homeostasis after trauma; however, a prolonged response contributes to multiorgan failure, hypermetabolism, complications, and death. Although IGF-1 has been shown to improve cell recovery and play a major role in liver regeneration, its effect on the hepatic acute phase response is not known.

METHODS

Sprague-Dawley rats (56 males) received a 60% total body surface area third-degree scald burn and were randomly divided to receive either rhIGF-I/BP-3 (10 mg/kg/day given subcutaneously) or saline (control). Rats were killed on postburn days 1, 2, 5, and 7 and serum glucose, electrolytes, acute phase reactant proteins, tumor necrosis factor alpha, interleukin 1 beta, interleukin 6, and rat and human serum IGF-I and IGFBP-3 were measured. Hepatic protein concentrations, hepatocyte proliferation, and hepatocyte apoptosis were determined.

RESULTS

No hypoglycemia or electrolyte imbalance could be shown in rats receiving the growth factor complex compared with saline. rhIGF-I/BP-3 increased serum protein on postburn days 2 and 7, albumin on days 5 and 7, and transferrin on days 1, 5, and 7, and decreased haptoglobin and alpha1-acid glycoprotein on postburn days 5 and 7 compared with controls. IGF-I/ BP-3 had no effect on type II acute phase proteins. Rats receiving IGF-I/BP-3 had lower serum levels of interleukin 1 beta and tumor necrosis factor alpha on the first day after burn compared with controls, whereas serum levels of interleukin 6 did not change. rhIGF-I/BP-3 significantly increased total liver protein content on postburn days 1, 2, 5, and 7 compared with controls. IGF-I/BP-3 increased hepatocyte proliferation and decreased hepatocyte apoptosis versus controls.

CONCLUSION

In combination with its principal binding protein, rhIGF-I decreases the proinflammatory cytokines interleukin 1 beta and tumor necrosis factor alpha, followed by a decrease in type I acute phase proteins. IGF-I/BP-3 had no effect on interleukin 6 and type II acute phase proteins. Decreases in acute phase protein and proinflammatory cytokine synthesis were associated with increases in constitutive hepatic proteins, total liver protein content, and hepatocyte proliferation. IGF-I/BP-3 attenuates the hypermetabolic response after thermal injury and may improve the clinical outcome.

Hepatocyte growth factor modulates the hepatic acute-phase response in thermally injured rats

OBJECTIVE

Hepatocyte growth factor (HGF) has been shown to modulate the acute-phase response in vitro. The specific in vivo role of HGF in this multifactorial response, however, remains unknown. This study examines the effects of exogenous HGF on the acute-phase response in thermally injured rats.

DESIGN

Prospective, randomized, laboratory study.

SETTINGS

Shriners Hospital for Children and University of Texas Medical Branch laboratories.

SUBJECTS

Fifty-six male Sprague-Dawley rats (weight range, 300-325 g).

INTERVENTION

Animals received a 60% total body surface area third-degree scald burn and were randomly divided to receive either 400 microg/kg/day i.v. HGF or saline (control).

MEASUREMENTS AND MAIN RESULTS

Serum acute-phase proteins, cytokines, and insulin-like growth factor (IGF)-I concentrations, as well as liver weight, protein and triglyceride content, IGF-I concentrations, and cytokine gene expression were measured 1, 2, 5, or 7 days after burn. Serum albumin was increased on days 2, 5, and 7 after burn, and transferrin was increased on day 7 after burn in HGF-treated rats compared with controls (p<.05). HGF increased alpha2-macroglobulin concentrations on postburn days 2, 5, and 7 compared with controls (p<.05). Serum interleukin-6 and tumor necrosis factor-alpha were significantly higher within 2 days of burn in rats treated with HGF (p<.05). HGF increased the hepatic gene expression of tumor necrosis factor-alpha compared with controls (p<.05). Serum IGF-I decreased in rats receiving HGF 1, 2, and 5 days after burn, whereas liver IGF-I concentrations were higher on days 1 and 7 after burn compared with controls (p<.05). Hepatic protein concentrations were higher in the HGF group compared with controls on postburn days 1, 2, and 7, with a concomitant increase in total liver weight (p<.05). HGF exerted a strong mitogenic effect on hepatocytes 1 and 2 days after thermal injury compared with controls (p<.05).

CONCLUSIONS

These findings suggest that HGF modulates the acute-phase response in vivo after burn and causes changes in liver morphology.

Biodistribution and feasibility of non-viral IGF-I gene transfers in thermally injured skin

Gene therapy using cationic liposomes containing cDNA is a relatively new approach with great potential; however, little is known about the mechanisms of dermal gene transfer, its biodistribution, systemic transfection, and cellular uptake. This study identifies mechanisms, transfection rates, and biodistribution of liposomal gene transfers in the skin of thermally injured rats using cDNA gene constructs coding for insulin-like growth factor-I (IGF-I) and Lac Z. Male Sprague-Dawley rats (350 to 375 g) were given a 60% total body surface area full-thickness scald burn that was followed by weekly subcutaneous injections of normal saline (control, n = 10), liposomes plus 0.2 microg Lac Z cDNA construct driven by a cytomegalovirus (CMV) promoter (vehicle, n = 10), or liposomes containing 2.2 microg cDNA coding for IGF-I plus 0.2 microg Lac Z cDNA construct driven by a CMV promoter (IGF-I cDNA, n = 10). Gene transfection was determined by histochemical and luminescent beta-galactosidase assays of blood, skin, liver, spleen, and kidney. Transcription of IGF-I cDNA to IGF-I mRNA was determined in skin cells by Northern blot analyses. Levels of IGF-I protein in blood, skin, liver, spleen, and kidney were measured by radioimmunoassay. The biological activity of the translated IGF-I was evaluated by the mitogenic activity in dermal cells and the rate of re-epithelization. Gene transfection was observed only in skin cells. The expression of IGF-I mRNA increased in skin cells of burned rats receiving liposomes containing the IGF-I cDNA construct compared with liposomes without the construct or normal saline. IGF-I protein levels in the skin of rats receiving the IGF-I cDNA was 176 +/- 4 ng/ml compared with 105 +/- 6 ng/ml for liposomes alone or 90 +/-3 ng/ml for saline (p < 0.05). The translated IGF-I protein was found biologically active in the skin by increasing skin cell proliferation and accelerating re-epithelization 33 days after thermal injury (p < 0.05). No systemic transfection could be detected. Skin cells transfected with liposomes encapsulating the IGF-I cDNA constructs increased the expression of IGF-I mRNA transcript and the expression of a biologically active IGF-I protein. Liposomes containing the cDNA coding for IGF-I present an effective approach to gene therapy in the skin.

Long-term outcomes of burned children after in-hospital cardiac arrest

OBJECTIVE

Cardiopulmonary resuscitation (CPR) in severely burned patients experiencing cardiac arrest (CA) has been considered by some as futile. The objective of this article is to report predisposing factors and the outcomes of burned children experiencing in-hospital CA at our institution.

DESIGN

The records of 595 children admitted from 1985 to 1998 with burns covering >35% of their total body surface area were reviewed. Thirty-four children receiving CPR after in-hospital CA were studied for predisposing factors and long-term outcomes.

SETTING AND PATIENTS

Shriners Burns Hospital. Burned children of both genders, 0.5-19 yrs of age, who experienced in-hospital CA and received CPR.

INTERVENTION

Standard burn care and CPR.

MEASUREMENTS AND MAIN RESULTS

Predisposing factors of CA, mortality, and long-term outcomes were measured. The incidence of CA in burned children with burns on >35% total body surface area was 5.7%. No significant difference in age or burn size could be shown between long-term CA survivors (n = 17) and nonsurvivors (n = 17). CPR was successful (defined as survival for at least 1 day after CA) in 22 of 34 children (65%), with 17 of the 22 survivors (77%) experiencing long-term survival, currently from 2-14 yrs. Significant predisposing factors of CA were sepsis, identified in 53% of the nonsurvivors vs. 12% of the survivors (p<.05), and delayed fluid resuscitation (>2 hrs after burn injury), identified in 82% of the nonsurvivors vs. 6% of the survivors (p<.001). There was only one morbid long-term survivor. This survivor was diagnosed as having anoxic brain injury with persistent neurologic deficiencies.

CONCLUSION

In this study, 50% of the burned children experiencing CA are long-term survivors. We suggest that all burned children with CA should be afforded cardiopulmonary resuscitation.

Insulinlike growth factor I plus insulinlike growth factor binding protein 3 attenuates the proinflammatory acute phase response in severely burned children

OBJECTIVE

To determine the effect of insulinlike growth factor I (IGF-I) in combination with its principal binding protein (IGFBP-3) on the hepatic acute phase response in severely burned children.

SUMMARY BACKGROUND DATA

The hepatic acute phase response is a cascade of events initiated to restore homeostasis after trauma. A prolonged response, however, may contribute to multiple organ failure, hypermetabolism, complications, and death.

METHODS

Twenty-two children with a mean total body surface area (TBSA) burn of 57 +/- 3% were given a continuous infusion of 1 to 4 mg/kg/day IGF-I/BP-3 for 5 days after wound excision and grafting. Eight children with a TBSA burn of 54 +/- 4% were given saline as controls. Before and 5 days after excision and grafting, blood samples were taken for serum hepatic constitutive protein, acute phase protein, and proinflammatory cytokine analysis.

RESULTS

Serum IGF-I levels in burned children given the IGF-I/BP-3 complex increased from 113 +/- 15 to 458 +/- 40 ng/mL and IGFBP-3 levels increased from 1.8 +/- 0.2 to 3.1 +/- 0.3 ng/mL. Levels of serum constitutive hepatic proteins (prealbumin, retinol-binding protein, and transferrin) increased with IGF-I/BP-3, whereas levels of type I acute phase proteins (C-reactive protein, alpha1-acid glycoprotein, and complement C-3) decreased when compared with controls. The complex had no effect on type II acute phase proteins. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) levels decreased with IGF-I/BP-3 compared with controls, with no effect on interleukin-6.

CONCLUSION

Severely burned children receiving IGF-I/BP-3 showed a decrease in IL-1beta and TNF-alpha followed by a decrease in type I acute phase proteins that was associated with a concomitant increase in constitutive hepatic proteins. Attenuating the proinflammatory acute phase with IGF-1/BP-3 response may prevent multiple organ failure and improve clinical outcomes after thermal injury without any detectable adverse side effects.

Effect of growth hormone on growth delay in burned children: a 3-year follow-up study

Children with severe burns benefit from acute therapy with recombinant human growth hormone by maintaining their original stature after injury. This effect is particularly apparent in children injured outside growth-spurt years.

Attenuation of the acute-phase response in thermally injured rats by cholesterol-containing cationic liposomes used as a delivery system for gene therapy

HYPOTHESIS

Cholesterol-containing cationic liposomes alone modulate the acute-phase response and cytokine expression in thermally injured rats and are an effective delivery system for gene therapy in trauma.

SETTING

Laboratory.

INTERVENTION

Fifty-six adult male Sprague-Dawley rats with a full-thickness scald burn covering 60% of total body surface area were randomly divided into 2 groups to receive either intravenous injections of cholesterol-containing cationic liposomes or saline (control).

MAIN OUTCOME MEASURES

Body weights, muscle and liver dry-wet weights, serum levels of constitutive hepatic proteins, acute-phase protein levels, and cytokine levels were determined at 1, 2, 5, and 7 days after thermal injury.

RESULTS

Rats receiving cholesterol-containing cationic liposomes had less body weight loss, increased serum transferrin levels, and decreased serum alpha1-acid glycoprotein levels when compared with controls (P<.05). Serum interleukin 1beta and tumor necrosis factor alpha levels were decreased in rats receiving liposomes at 1 and 2 days after burn compared with controls (P<.05).

CONCLUSIONS

These results suggest that cholesterol-containing cationic liposomes alone may have a beneficial effect in modulating the hypermetabolic response after burn injury by decreasing type 1 acute-phase proteins and the expression of the proinflammatory cytokines interleukin 1beta and tumor necrosis factor alpha. Therefore, cholesterol-containing cationic liposomes appear to be suitable as a delivery system for gene therapy in trauma.

Effect of multiple gene transfers of insulinlike growth factor I complementary DNA gene constructs in rats after thermal injury

HYPOTHESIS

Multiple subcutaneous injections of cholesterol-containing cationic liposomes encapsulating the complementary DNA (cDNA) gene for insulinlike growth factor I (IGF-I) increase the rate of transfected skin cells and result in increased IGF-I protein levels in the skin with subsequent improvement in wound healing when compared with a single injection.

SETTING

Laboratory.

INTERVENTION

Twenty-four adult male Sprague-Dawley rats (350-375 g) received a full-thickness scald burn on 60% of their body surface. These rats were randomly divided to receive either 1 injection of liposomes containing 2.2 microg-cytomegalovirus-driven cDNA coding for IGF-I and 0.2 microg of the Lac Z gene cDNA construct, or 2 injections of liposomes containing 2.2 microg cytomegalovirus-driven cDNA coding for IGF-I and 0.2 microg of the Lac Z gene cDNA construct.

MAIN OUTCOME MEASURES

Transfection rates and IGF-I protein levels in the skin and physiological responses to the IGF-I gene therapy, evaluated from changes in body weight, protein content in serum and liver, and the rate of burn wound healing.

RESULTS

There was a significant decrease in transfection rate and IGF-I protein expression distal from the injection site in animals receiving 1 injection, as compared with a consistent increase in rats receiving multiple injections. Multiple injections improved the response to thermal trauma by increasing the extent of the healed burn wound 33 days after thermal injury (single injection, 31% +/- 1% vs multiple injections, 38% +/- 2%), total serum protein (single injection, 52 +/- 0.5 g/L vs multiple injections, 55 +/- 0.6 g/L), and total liver protein (single injection, 82.0 +/- 0.3 mg/mL vs multiple injections, 91.0 +/- 3.8 mg/mL), P<.05.

CONCLUSIONS

Gene transfer rates can be increased by multiple injections of liposomes encapsulating IGF-I cDNA constructs. Increased transfer results in greater IGF-I protein skin concentrations, accelerated wound healing, and increased serum and liver protein concentrations. The clinical relevance of these findings is that liposomal gene constructs should be applied in well-defined distances to improve gene transfer in the skin, and thus clinical outcome after thermal injury.

Lung surfactant kinetics in conscious pigs

The primary goal of this study was to determine the contributions of plasma free fatty acids (FFA) and de novo synthesized fatty acids (FA) to lung surfactant phosphatidylcholine (PC) synthesis. A new stable isotope tracer model was developed in which [1, 2-(13)C(2)]acetate and uniformly labeled [U-(13)C(16)]palmitate were infused in nine normal overnight fasted pigs to quantify surfactant kinetics in the basal state and during low-dose glucose infusion (2 mg. kg(-1). min(-1)). There was no effect of glucose; therefore, all data were pooled. The surfactant PC-bound palmitate incorporation rate from plasma palmitate was 20.9 +/- 1.9 nmol palmitate. h(-1). g wet lung(-1), compared with the rate of 2.1 +/- 0.3 nmol palmitate. h(-1). g wet lung(-1) from de novo synthesized palmitate. The PC-bound palmitate secretion rate from the lamellar body pool to the alveolar surface pool was 239 +/- 26 nmol palmitate. h(-1). g wet lung(-1). Approximately 90% of the secreted PC recycled back to the lamellar bodies for reutilization. We conclude that plasma is the primary contributor of FA for surfactant PC synthesis under the conditions of this experiment.

IGF-I gene transfer in thermally injured rats

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 beta-galactosidase, liposomes plus cDNA for IGF-I and beta-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 beta-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.

Recombinant human growth hormone alters acute phase reactant proteins, cytokine expression, and liver morphology in burned rats

BACKGROUND

The effects of exogenous recombinant human growth hormone (rhGH) on hepatic acute phase reactant proteins, cytokine expression, and liver morphology were studied in thermally injured rats to define whether rhGH alters the acute phase response.

MATERIALS AND METHODS

Sprague-Dawley rats (56 males) receiving a 60% TBSA third-degree scald burn were randomly divided into two groups to receive either 2.5 mg/kg/day sc rhGH or saline. Rats were sacrificed on Postburn Days 1, 2, 5, and 7. Serum acute phase reactant proteins and cytokines TNF-alpha, IL-1alpha, IL-1beta, and IL-6 were measured. Hepatocyte proliferation, hepatic cytokine gene expression, and liver protein concentrations were determined.

RESULTS

Recombinant hGH increased serum albumin on Days 5 and 7 after burn (P < 0.05). Serum haptoglobin and alpha1-acid glycoprotein levels decreased at 2, 5, and 7 days after burn compared to saline (P < 0.05). In rats treated with rhGH, serum IL-1beta decreased 1 day postburn, while serum TNF-alpha increased 5 days after burn compared to saline (P < 0.05). Serum IL-6 and IL-1alpha did not change. Hepatic RNA levels for TNF-alpha were significantly elevated on Day 1 postburn compared to saline (P < 0. 05). Hepatic protein content increased on Days 2, 5, and 7 postburn compared to saline (P < 0.05). Hepatocyte proliferation in rhGH-treated rats increased on Day 5 after burn (P < 0.05).

CONCLUSION

Data indicate that rhGH alters the hepatic acute phase response by decreasing type I acute phase proteins and modulating IL-1-like cytokine expression. These changes are associated with increased hepatocyte mitosis and serum and total liver protein concentrations.

Electrical injuries: a 30-year review

INTRODUCTION

Electrical injuries currently remain a world-wide problem. This study determines whether electrical injuries at our institution have changed in the past 30 years, and identifies electrical burn complications and any high-risk groups.

METHODS

From 1967 to 1997, 185 children admitted to our institute were identified with electrical burns. Fifty-five percent of these electrical burns occurred from 1987 to 1997.

RESULTS

During the last 10 years of this study, 43% of the electrical injuries (n = 44) were from low voltage (120-240 V) and 57% (n = 58) from high voltage (>1,000 V). In 17 children, serious low-voltage burns were identified as oral commissure burns. These were treated conservatively with one to two reconstructive procedures within 2 years. High-voltage injuries were mainly identified in male children (age 11 to 18 years). Thirty-three percent of high-voltage burns required amputation, 29% had deep muscle involvement, and 24% required either escharotomy or fasciotomy. No mortalities were reported.

CONCLUSION

Although the incidence of low-voltage burns is currently on a steady decline, high-voltage injuries remain a problem, particularly in adolescent males.

Growth hormone attenuates tumor necrosis factor alpha in burned children

BACKGROUND

Recombinant human growth hormone (rhGH) has been shown to favorably modulate the acute-phase response and may improve the clinical outcome.

OBJECTIVE

To examine whether rhGH attenuates the elevated tumor necrosis factor alpha (TNF-alpha) levels that correlate with increased multiorgan failure and mortality in burned adults and children.

DESIGN

Twenty children with burns of greater than 40% of the total body surface area were randomly divided into 2 groups to receive placebo (n = 10) or rhGH, 0.2 mg/kg per day intramuscularly (n = 10).

SETTING

Pediatric burn hospital.

MAIN OUTCOME MEASURE

Serum TNF-alpha levels by enzyme-linked immunoassay at baseline (day 0) and at 21 and 42 days after injury. For statistical analysis, we used the Kruskal-Wallis and Friedman tests.

RESULTS

No significant differences in age (mean +/- SD, 6.2+/-1.6 vs 5.0+/-1.2 years) or percentage of total body surface area burn (mean +/- SD, 65.1%+/-8.2% vs 57.1%+/-5.2%) could be shown between the groups given rhGH and placebo. Baseline TNF-alpha levels were elevated from reference values in both groups. Twenty-one and 42 days after rhGH administration, serum TNF-alpha levels were significantly decreased from those at baseline (P<.05). No significant decrease in TNF-alpha levels was observed in the placebo group (P = .5).

CONCLUSIONS

Recombinant human growth hormone significantly lowers serum TNF-alpha levels after burn injury. This is consistent with the beneficial effect that rhGH has on the acute-phase response.

Acute renal dysfunction in severely burned adults

BACKGROUND

Factors contributing to mortality in burned children with acute renal failure have been identified; however, they have not been identified in thermally injured adults.

METHODS

The records of 1,404 acutely burned adults admitted to the Blocker Burn Unit were reviewed. Seventy-six patients with acute renal dysfunction and burns covering more than 30% of their total body surface area with a full-thickness component greater than 10% total body surface area were identified. These patients were divided into those admitted from 1981 through 1989 (n = 35) and those admitted from 1990 to 1998 (n = 41).

RESULTS

No significant differences could be shown in the incidence of acute renal dysfunction (5.4 vs. 5.1%) or mortality (88 vs. 87%) for the two time periods, respectively. Sixty-seven percent of the survivors were younger than 40 years of age, compared with only 25% of nonsurvivors (p < 0.02); sepsis was identified in 44 and 96% of survivors and nonsurvivors, respectively (p < 0.001). Fluid resuscitation was delayed in survivors by 1.7+/-1.0 hours compared with 4.4+/-2.1 hours in nonsurvivors (p < 0.001).

CONCLUSION

early fluid resuscitation and the prevention of sepsis may reduce the incidence of acute renal dysfunction and mortality in burned adults.

Growth hormone treatment in pediatric burns: a safe therapeutic approach

OBJECTIVE

To determine the safety and efficacy of recombinant human growth hormone (rhGH) in the treatment of children who are severely burned.

SUMMARY BACKGROUND DATA

During the last decade, we have used recombinant human growth hormone (rhGH; 0.2 mg/kg/day s.q.) to successfully treat 130 children with more than 40% total body surface area (TBSA) burns to enhance wound healing and decrease protein loss. A significant increase in the mortality of adult patients in the intensive care unit who were given rhGH has recently been reported in two large European trials which questions the therapeutic safety of rhGH.

METHODS

The records of 263 children who were burned were reviewed. Patients receiving either rhGH at 0.2 mg/kg/day subcutaneously as part of a randomized clinical trial (n = 48) or therapeutically (n = 82) were compared with randomized placebo-administered controls (n = 54), contiguous matched controls (n = 48), and matched patients admitted after August 1997, after which no patients were treated with rhGH (n = 31). Morbidity and mortality, which might be altered by rhGH therapy, were considered with specific attention to organ function or failure, infection, hemodynamics, and calcium, phosphorous, and albumin balance.

RESULTS

A 2% mortality was observed in both rhGH and saline placebo groups in the controlled studies, with no differences in septic complications, organ dysfunction, or heart rate pressure product identified. In addition, no difference in mortality could be shown for those given rhGH therapeutically versus their controls. No patient deaths were attributed to rhGH in autopsies reviewed by observers blinded to treatment. Hyperglycemic episodes and exogenous insulin requirements were higher among rhGH recipients, whereas exogenous albumin requirements and the development of hypocalcemia was reduced.

CONCLUSIONS

Data indicate that rhGH used in the treatment of children who were severely burned is safe and efficacious.

Recombinant human growth hormone modulates Th1 and Th2 cytokine response in burned mice

OBJECTIVE

To determine whether growth hormone (GH) influences the production of type 1 T-helper (Th1) and type 2 T-helper (Th2) cytokine responses after burn.

SUMMARY BACKGROUND DATA

GH has been shown to influence immunoregulation. The authors previously reported improved mortality in burned mice treated with GH after infection with herpesvirus. Other work has shown that impaired immunity after burn was characterized by conversion of Th cell populations from Th1 cells to Th2 cells, suggesting an increased susceptibility of patients with burns to infection.

METHODS

The production of Th1 and Th2 cytokine from isolated splenic lymphocytes taken from GH-treated burned mice was measured.

RESULTS

At 1 and 11 days after burn, Th1 cytokine production by splenic lymphocytes from burned mice treated with GH was greater than in mice receiving saline. In fact, Th1 cytokine production was greater than that of nonburned mice. In addition, the production of Th2 cytokines was decreased.

CONCLUSIONS

Results suggest that the Th1/Th2 response is altered after burn, and this can be reversed with GH. GH, therefore, may improve resistance to infection in patients with burns.

Mortality in burned children with acute renal failure

BACKGROUND

During the past 13 years, mortality from acute renal failure in burned children has been on the decline.

OBJECTIVE

To determine which new burn therapies contributed to the decrease in mortality.

DESIGN

The medical records of burned children admitted from February 1966 to January 1997 were reviewed, and the outcome of changes in the treatment of burned children were compared.

PATIENTS AND METHODS

Sixty children with acute renal failure were identified. These children were divided into those admitted from 1966 to 1983 (n=24) and those admitted from 1984 to 1997 (n=36). They were compared with matched control subjects from the same period without renal failure. Values are presented as means+/-SEMs. Statistical analysis was by the Student t test or chi2 analysis.

RESULTS

Mortality rates in burned children with acute renal failure decreased from 100% before 1983 to 56% after 1984 (P<.001). The time between a burn injury and the initiation of intravenous fluid resuscitation was 8.6+/-1.7 hours before 1983 compared with 3.0+/-0.5 hours after 1984 (P<.005). The time between a burn injury and complete early wound excision decreased from 228+/-37 hours before 1983 to 40+/-7 hours after 1984 (P<.001). The incidence of sepsis decreased from 71% to 44% in these periods (P<.05). After 1984, survivors had a shorter time delay for fluid resuscitation than nonsurvivors (1.7+/-0.5 hours vs 4.8+/-0.9 hours; P<.005) and a lower incidence of sepsis (19% vs 60%; P<.05). From 1984 to 1997, burned children with acute renal failure who did not require dialysis had significantly shorter delays for fluid resuscitation (2.2+/-0.5 hours vs 4.4+/-0.9 hours) and complete wound excision (29+/-6 hours vs 49+/-7 hours) compared with those requiring dialysis (P<.05 for both).

CONCLUSION

Early adequate fluid resuscitation, early wound excision, and better infection control may reduce mortality in burned children with acute renal failure.

Growth hormone improves the resistance of thermally injured mice infected with herpes simplex virus type 1

BACKGROUND

Growth hormone (GH) has been shown to promote wound healing and to improve protein metabolism in burned patients. Through immunomodulation, GH has also protected rats infected with Salmonella typhimurium and mice infected with Escherichia coli. In spite of advances in the management of patient care for those with thermal injuries, high mortality rates of burned patients as a result of infections are of special concern. An improvement in the resistance of burned patients to certain infections will make the beneficial role of GH very clear. In this study, therefore, the immunomodulating effects of recombinant human GH (rhGH) in thermally injured mice exposed to opportunistic herpesvirus infections were investigated.

METHODS

(1) Burned mice, exposed to herpes simplex virus type 1 (HSV-1), were treated subcutaneously with rhGH (4 mg/kg) and observed for 21 days to determine the protective antiviral effect of rhGH. (2) Because of reports describing a lack of interferon-gamma (IFN-gamma) responsiveness in burned mice, the IFN-gamma-producing ability of the splenic mononuclear cells (SMNC) from burned mice treated with rhGH was examined. (3) Because the generation of burn-associated suppressor macrophages that can inhibit the IFN-gamma production by SMNC has been previously described, the suppressor cell activities of macrophages from burned mice treated with rhGH were examined.

RESULTS

After exposure to lethal amounts of HSV-1, mice treated with rhGH displayed a reduced mortality rate compared with control mice treated with saline. SMNC from burned mice treated with rhGH produced IFN-gamma, whereas this cytokine was not produced by SMNC from burned mice treated with saline. Also, an inhibition of the generation of burn-associated suppressor macrophages was displayed in burned mice treated with rhGH.

CONCLUSION

Exogenous administration of rhGH caused an improvement in the resistance of burned mice to HSV-1 infection. In burned mice treated with rhGH, the impaired IFN-gamma responsiveness was restored and the generation of burn-associated suppressor macrophages was inhibited. IFN-gamma, a typical antiviral cytokine induced by rhGH through the regulation of the suppressor macrophage generation, may therefore play a role in the protection of burned mice infected with a lethal amount of HSV-1.

Effects of insulin on wound healing

BACKGROUND

Insulin plus glucose, given for 7 days to hypermetabolic burn patients, has been shown to stimulate limb protein anabolism. We hypothesized that insulin plus glucose given to burn patients would also stimulate wound healing.

METHODS

Six patients with burns >40% total body surface area were randomized to receive insulin or placebo in a crossover study during the healing of their first and second donor sites. Insulin treatment was titrated at 25 to 49 U/h to achieve a plasma insulin level of 400 to 900 microU/mL for 7 days. Patients receiving insulin received dextrose 50 at 20 to 50 mL/h, titrated to maintain euglycemia. Donor-site biopsies were taken at 7 days and evaluated by three observers blinded to the treatment.

RESULTS

The mean (+/-SD) donor-site healing time was reduced from 6.5 +/- 1.0 days with placebo to 4.7 +/- 1.2 days during insulin infusion (p < 0.05). Laminin showed intense staining along the basal lamina and blood vessels. Collagen type IV staining also increased after insulin therapy compared with placebo.

CONCLUSION

Data indicate that high doses of insulin and glucose can be safely administered to massively burned patients to improve wound matrix formation.

Prolonged use of propranolol safely decreases cardiac work in burned children

Propranolol has been shown to be effective for as long as 5 days in massively burned children to reduce heart rate and cardiac work. This article describes the use of propranolol given for 10 days to burned children to test whether the drug remains effective and safe in reducing heart rate and cardiac work for longer periods. We prospectively studied 22 children, 1 to 10 years of age with burns covering > or = 40% of their total body surface area. These children were treated with 0.5 to 1.0 mg/kg propranolol given orally or intravenously every 8 hours for 10 days. In both septic and nonseptic patients, propranolol significantly decreased their daily average heart rate (between 10% and 13%, p < 0.05) and rate-pressure product (between 10% and 16%, p < 0.05) compared with their 24-hour mean before propranolol treatment. No significant change in mean arterial blood pressure, or plasma urea nitrogen creatinine or glucose levels could be shown. No hypotension, hypothermia, azotemia, hyperglycemia or hypoglycemia, arrhythmia, bronchospasm, or peripheral ischemia was noted during or after treatment. Whereas propranolol lowered heart rate more per milligram per kilogram body weight when given intravenously, both routes were safe and effective. From these data, we conclude that propranolol can be given to decrease the work of the heart safely and effectively for > or = 10 days.

Mortality determinants in massive pediatric burns. An analysis of 103 children with > or = 80% TBSA burns (> or = 70% full-thickness)

OBJECTIVE

Survivors and nonsurvivors among 103 consecutive pediatric patients with massive burns were compared in an effort to define the predictors of mortality in massively burned children.

SUMMARY BACKGROUND DATA

Predictors of mortality in burns that are used commonly are age, burn size, and inhalation injury. In the past, burns over 80% of the body surface area that are mostly full-thickness often were considered fatal, especially in children and in the elderly. In the past 15 years, advances in burn treatment have increased rates of survival in those patients treated at specialized burn centers. The purpose of this study was to document the extent of improvement and to define the current predictors of mortality to further focus burn care.

METHODS

Beginning in 1982, 103 children ages 6 months to 17 years with burns covering at least 80% of the body surface (70% full-thickness), were treated in the authors' institution by early excision and grafting and have been observed to determine outcome. The authors divided collected independent variables from the time of injury into temporally related groups and analyzed the data sequentially and cumulatively through univariate statistics and through pooled, cross-sectional multivariate logistic regression to determine which variables predict the probability of mortality.

RESULTS

The mortality rate for this series of massively burned children was 33%. Lower age, larger burn size, presence of inhalation injury, delayed intravenous access, lower admission hematocrit, lower base deficit on admission, higher serum osmolarity at arrival to the authors' hospital, sepsis, inotropic support requirement, platelet count < 20,000, and ventilator dependency during the hospital course significantly predict increased mortality.

CONCLUSIONS

The authors conclude that mortality has decreased in massively burned children to the extent that nearly all patients should be considered as candidates for survival, regardless of age, burn size, presence of inhalation injury, delay in resuscitation, or laboratory values on initial presentation. During the course of hospitalization, the development of sepsis and multiorgan failure is a harbinger of poor outcome, but the authors have encountered futile cases only rarely. The authors found that those patients who are most apt to die are the very young, those with limited donor sites, those who have inhalation injury, those with delays in resuscitation, and those with burn-associated sepsis or multiorgan failure.

Growth hormone improves immune function and survival in burned mice infected with herpes simplex virus type 1

Recombinant human growth hormone (rhGH) is often used clinically for the treatment of burned patients to promote wound healing and to improve protein metabolism. Recently, the immunomodulatory activity of GH has been described, but it remains unclear whether immune abnormalities associated with burn are improved by rhGH administration. To determine the immunoregulatory activities of rhGH in thermal injury, the survival of burned mice infected with herpes simplex virus type 1 (HSV-1), along with interferon-gamma (IFN-gamma) production by splenic mononuclear cells (SMNCs), and generation of cytostatic macrophages in burned mice were examined after exogenous administration of rhGH. Data showed that the mortality after HSV-1 infection was improved in burned mice treated with a 4-mg/kg dose of rhGH every other day for five doses. Also, the decreased IFN-gamma response of SMNCs from burned mice improved with rhGH therapy. Further, cytostatic macrophages were generated in burned mice treated with rhGH, whereas these macrophages were not demonstrated in burned mice treated with saline. These results indicate that rhGH can improve immune function in burned mice, specifically improving survival in HSV-1 infection, boltering IFN-gamma production by SMNCs, and increasing production of cytostatic macrophages.

Combined insulin-like growth factor-1 and growth hormone improves weight loss and wound healing in burned rats

The anabolic effects of growth hormone (GH) in burned patients appear to act both directly and through insulin-like growth factor-1 (IGF-1). We, therefore, hypothesize that exogenous GH plus IGF-1 will attenuate increases in metabolism and lean muscle wasting while promoting wound healing.

MATERIALS AND METHODS

Rats, each weighing 440-470 g, were given a 35% total body surface area, full-thickness scald burn and divided into four groups to receive placebo (burned controls), bovine GH (2.5 mg/kg/day), IGF-1 (2.0 mg/kg/day), or bovine GH plus rhIGF-1 (2.5 + 2.0 mg/kg/day), respectively, for 8 weeks.

RESULTS

Total body weight gain after 8 weeks averaged 110 g for GH plus IGF-1 compared with gains of 49 and 11 g for GH or IGF-1 alone, respectively. Burned controls lost 24 g. Metabolic rates were significantly reduced in all groups receiving growth hormones. Gastrocnemius muscle dry weight was significantly increased in those receiving GH plus IGF-1 compared with GH and IGF-1 alone or burned controls (p < .01).

CONCLUSIONS

Data show that GH plus IGF-1 synergistically increased lean muscle weight, total body weight, and was more effective in re-epithelialization of the burn wound than either GH or IGF-1 alone.

Growth hormone and IGF-I therapy in the hypercatabolic patient

The use of exogenous GH to increase its circulating concentration, may benefit critically ill patients by increasing their nitrogen retention and promoting the wound healing process. GH also changes protein production in wounds, causes higher levels of insulin and changes substrate utilization. Its effects are anabolic, diabetogenic and lipolytic, acting through both direct and indirect mechanisms. The effects on carbohydrate and fat metabolism are directly mediated through specific GH receptors, while its effect on protein is mediated through IGF-I. Its effects on IGF-I production and the induction of IGF binding proteins are currently being studied in an effort to better understand the mechanism of GH actions during stress.

Beta-blockade lowers peripheral lipolysis in burn patients receiving growth hormone. Rate of hepatic very low density lipoprotein triglyceride secretion remains unchanged

OBJECTIVE

The purpose of this study was to determine the effect of propranolol on peripheral lipolysis in massively burned children during treatment with recombinant human growth hormone (rhGH), and to ascertain whether decreased free fatty acid availability for re-esterification would alter the hepatic rate of secretion of triglycerides (TGs) bound to very low density lipoproteins (VLDLs).

BACKGROUND

Fatty liver occurs in severely burned patients, often resulting in a twofold increase in liver size. This could be the result of an imbalance between increased provision of free fatty acids from peripheral lipolysis, coupled with no increase in fat oxidation, and insufficient rate of secretion of TGs from the liver.

METHODS

In a cross-over study, six burned children were treated with either rhGH or rhGH plus propranolol. On the sixth day of treatment, isotopic tracer infusions were conducted to determine the rate of release of free fatty acid (Ra FFA) from peripheral tissue and the rate of secretion of VLDL-bound TGs by the liver.

RESULTS

Exogenous rhGH increased Ra FFA in children with large third-degree burns. Propranolol decreased Ra FFA, but the rate of secretion of fatty acids in the form of VLDL-TG from the liver was maintained. Plasma FFA, as opposed to fatty acids newly synthesized in the liver, were the primary precursors for hepatic triglyceride synthesis.

CONCLUSIONS

The administration of propranolol to burned children receiving rhGH is safe, has salutary cardiovascular effects, decreases the release of FFA from adipose tissue and increases the efficiency of the liver in secreting fatty acids as VLDL TGs.

Growth hormone treatment for burned children

Several growth hormones show promise in the treatment of burn injuries, particularly for paediatric patients. Animal studies and clinical trials indicate that growth hormones help modulate the devastating effects of the hypermetabolic response to burn injury and improve wound healing. Recombinant human growth hormone (rhGH) has been shown to reduce loss of body weight, stimulate protein synthesis, increase epithelial cell proliferation, and accelerate wound healing. Accelerated wound closure reduces the risk of infection, shortens hospital stay, and lowers overall medical costs. Current investigations are in progress to determine the effects of rhGH on anabolic growth arrests experienced by paediatric burn survivors.

Characterization of growth hormone enhanced donor site healing in patients with large cutaneous burns

BACKGROUND

Human growth hormone is an anabolic agent that attenuates injury-induced catabolism and stimulates protein synthesis. Recombinant human growth hormone (rhGH) administered therapeutically to patients with massive burns has been shown to increase the rate of skin graft donor site healing. It has been postulated that growth hormone affects wound healing and tissue repair by stimulating the production of insulin-like growth factor-1 (IGF-1) by the liver to increase circulating IGF-1 concentrations. The mechanism by which it improves wound healing, however, remains in question. The authors hypothesize that rhGH up-regulates IGF-1 receptors and IGF-1 levels both systemically and locally in the wound site to stimulate cell mitosis and increase synthesis of laminin, collagen types IV and VII, and cytokeratin. This hypothesis was tested in nine patients with burns covering > 40% of total body surface area.

OBJECTIVE

The authors assessed the efficacy of rhGH in promoting several major building materials in the donor site of patients with massive burns.

METHODS

Ten massively burned patients with full-thickness burns covering more than 40% of total body surface area were participants in a placebo-controlled prospective study to determine the efficacy of 0.2 mg/kg/day rhGH on donor site wound healing and to identify some of the major components involved in wound healing and its integrity.

RESULTS

Donor sites in burn patients receiving rhGH showed an increased coverage by the basal lamina of 26% for placebo to 68% coverage of the dermal-epidermal junction. Insulin-like growth factor-1 receptors and laminin, types IV and VII collagen, and cytokeratin-14 all increased significantly. Healing times of the donor sites were significantly decreased compared with patients receiving placebo.

CONCLUSION

Results indicate that growth hormone or its secondary mediators may directly stimulate the cells of the epidermis and dermis during wound healing to produce the structural proteins and other components needed to rebuild the junctional structures.

Beneficial wound healing and metabolic effects of clenbuterol in burned and nonburned rats

Clenbuterol is known to increase muscle mass in nonburned and burn-injured subjects. The effects of clenbuterol on wound healing and the postburn response were examined in both nutritionally matched and free-feeding groups of rats. Rats received either a sham or 30% total body surface area scald burn and then a dorsal incision. Clenbuterol (2 mg/kg/day) was administered subcutaneously via a miniosmotic pump. The burn injury resulted in a sustained non-temperature-dependent hypermetabolism that was not altered by clenbuterol. Clenbuterol induced muscle anabolism and body growth in sham and burned-injured animals. Treated sham animals demonstrated increased wound breaking strength. Matched nutritional intake attenuated the body weight gain, although muscle anabolism was still evident in treated animals. Clenbuterol elevated RNA concentration in the tibialis muscle and reduced it in the liver. There was no statistical difference in wound strength when nutritional intake was matched. Clenbuterol's actions appear to be dependent on substrate availability. Clenbuterol may prove beneficial in patients with severe prolonged catabolic state, such as that associated with burn injury, by promoting protein anabolism and enhancing wound healing.

Superoxide dismutase and leupeptin prevent delayed reperfusion injury in the rat small intestine during burn shock

Delayed fluid resuscitation during burn shock is thought to compromise the integrity of gut mucosa and allow enteric bacteria to cross the luminal wall and infect other sterile organ systems. Superoxide dismutase, a free-oxygen radical scavenger; leupeptin, a protease inhibitor; and verapamil, a calcium channel blocker, were studied to evaluate their efficacy in maintaining cellular integrity in the gut of thermally burned rats whose fluid resuscitation had been delayed. Fifty male rats weighting 280 to 320 gm were given a full-thickness scald burn covering 50% total body surface area. Ten received early fluid resuscitation beginning half an hour after burn, and 40 received fluid resuscitation delayed by 6 hours. Those receiving delayed resuscitation were given superoxide dismutase (n = 10), leupeptin (n = 10), verapamil (n = 10), or a placebo of normal saline solution (n = 10) at the time of fluid resuscitation. Ileal mucosa samples were harvested, and adenosine triphosphate, diphosphate, and monophosphate were measured. Adenosine triphosphate, total nucleotides, and energy charge potential were significantly lower in the placebo group without therapy compared with those of the early resuscitation group. Superoxide dismutase and leupeptin therapy prevented this drop in cellular energy. Total water content was significantly increased in the placebo group compared with that of the early resuscitation group; superoxide dismutase was able to prevent this increase. Data indicate that intestinal reperfusion injury in burned rats can be effectively modulated with superoxide dismutase or leupeptin therapy.

Lipolysis in burned patients is stimulated by the beta 2-receptor for catecholamines

OBJECTIVE

To determine if the cardiovascular effects of excessive catecholamines could be selectively blocked in severely burned patients without adversely affecting protein or fat kinetics.

DESIGN

Prospective cohort study.

SETTING

A large tertiary care referral center in Galveston, Tex.

PATIENTS

Sixteen patients with greater than 40% body surface area burns.

INTERVENTIONS

Patients were randomly selected to receive propranolol hydrochloride, a nonselective beta 1- and beta 2-blocker, or metoprolol tartrate, a selective beta 1-blocker.

MAIN OUTCOME MEASURES

Heart rate; rate-pressure product; rate of appearance of urea, glucose, and leucine; and leucine oxidation were measured before and after selective or nonselective beta-adrenergic blockade.

RESULTS

Propranolol and metoprolol caused a significant decrease in heart rate, from a mean (+/- SD) of 143 +/- 15 to 115 +/- 11 and from 147 +/- 17 to 120 +/- 9 beats per minute, respectively, during the 5-day study period. Neither the rate of appearance of urea nor the rate of urea production were significantly altered by propranolol or metoprolol therapy. Only propranolol produced a significant decrease (P < .05) in the rate of appearance of glycerol, from a mean (+/- SD) of 5.54 +/- 0.62 to 3.07 +/- 0.7 mumol/kg per minute. The rate of appearance of leucine, used as an index of total body protein catabolism, was not significantly altered by either beta-blocker.

CONCLUSIONS

Selective beta 1-adrenergic blockade did not reduce lipolysis; however, a beta 1- and beta 2-adrenergic blockade significantly reduced lipolysis. Thus, the increased lipolysis, characteristic of severely burned patients, is caused by stimulation of the beta 2-adrenergic receptors for catecholamines.