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.

Use of previously burned skin as random cutaneous local flaps in pediatric burn reconstruction.

Reconstruction after post-burn scarring remains a challenge. It is especially true in the severely burned patient, who normally presents with a paucity of donor sites. Healed skin from areas that had been burned and skin from grafted areas (termed as previously burned skin) have been occasionally used as flaps, but their safety is still in debate. We studied all patients undergoing burn reconstruction with normal skin flaps and previously burned skin flaps in the same operative procedure between April 1998 and October 1998 to determine the safety of flaps including burned and healed tissues. Patients served as their own controls. Three hundred and fifty-three local flaps were studied in 74 patients. These included 238 previously burned skin flaps and 115 normal skin flaps. There were no differences in complication rates between groups and only one previously burned skin flap suffered from complete necrosis. The use of local previously burned skin as flaps in burn reconstruction is safe. Reconstruction with flaps should be considered as first choice in burn reconstruction regardless of the quality of the local tissue.

3D numerical reconstruction of the hyperthermia induced temperature distribution in human sarcomas using DE-MRI measured tissue perfusion: validation against non-invasive MR temperature measurements.

Essential to the success of optimized thermal treatment during hyperthermia is accurate modelling. Advection of energy due to blood perfusion significantly affects the temperature. Without accurate estimates of the magnitude of the local tissue blood perfusion, accurate estimates of the temperature distribution can not be made. It is shown here that the blood mass flow rate per unit volume of tissue in the Pennes' bio-heat equation can be modelled using a relative perfusion index (RPI) determined with dynamic-enhanced magnetic resonance imaging (DE-MRI). Temperature distributions in two patients treated with hyperthermia at Duke University Medical Center for high-grade leg tissue sarcomas are modelled, and the resultant temperatures are compared to measured temperatures using a non-invasive MR thermometry technique. Significant correlations are found between the DE-MRI perfusion images, the MR temperature images, and the numerical simulation of the temperature field. The correlation between DE-MRI measured values and advective heat loss in tissue is used to scale the perfusion distribution, thereby allowing the continuum model to account for the local thermal impact of vasculature in the tumour. Large vessels in tumour and neighbouring healthy tissue need to be taken into account in order to accurately describe the complete temperature distribution.

Cadaveric allograft discards as a result of positive skin cultures.

INTRODUCTION: The availability of cadaveric allograft is often limited by potentially pathogenic microbial organisms. Little data exists on cadaveric allograft discard rates related to positive microbiology. The purpose of this retrospective review was to determine the cadaveric allograft discard rates related positive microbiology and the subsequent breakdown of those organisms involved. METHODS: From January 1995 to June 1997, 1112 donors were screened and procured after informed consent had been obtained. The procedures used were in accordance with American Association of Tissue Banks (AATB) standards and guidelines. The number of discards due to positive skin cultures was reviewed and analyzed for type of microbial organism. RESULTS: Fifty-four donors (4.9%) were discarded due to positive skin cultures. Methicillin resistant Staphylococcus epidermidis, (MRSE), was the most predominant organism (22.2%), followed by gram negative rods as a group (18.5%), with Aspergillus species being the least predominant isolate. CONCLUSION: Despite the strict adherence to AATB protocol, microbial contamination of cadaveric allograft skin does not reach zero. It is not surprising that S. epidermidis was the predominant isolate, since skin is one of its common habitats. Continued vigilance in microbial testing remains paramount to ensure the quality of the allograft.

Cadaver donor discards secondary to serology.

The use of cadaveric skin has made a major impact in the survival of patients experiencing major thermal injury. However, the availability of cadaveric skin is often limited by potentially pathogenic organisms. Very little data exists as to why cadaveric skin from donors who have been previously screened was discarded. From March 1994 to March 1996, 813 donors were referred to our tissue bank. All donors were reviewed for the cause of death, history and physical, and social history. One hundred fifty-three donors screened were discarded. Sixty-one donors of this group were discarded because of positive serologies. The following are the percentages of the specific positive serologies: hepatitis B core antibody, 52.3%; hepatitis B surface antigen, 18.1%; hepatitis C virus antibody, 14.3%; human immunodeficiency virus antibody, 4.9%; human T lymphocyte virus antibody, 4.9% and syphilis, 5.5%. Retrospectively, all donor screening questionnaires were reviewed for possible indicators in relation to positive serologic testing. Current screening methods, although excellent in social screening, still fail to identify a significant number of donors who may have positive serologies because of hepatitis, human immunodeficiency virus, human T lymphocyte virus, or syphilis. As the field of tissue banking continues to evolve, the focus will need to be directed toward better screening mechanisms in order to decrease our current discard rates after donors have been approved through the screening process.

Reconstruction of the pediatric burned hand.

It is clear that reconstruction of pediatric hand burns is a complicated task (Fig. 8), and attention to details during the acute phase of injury may be surgeons' greatest ally in subsequent functional rehabilitation of the hand. Reducing edema, maintaining digital circulation, limiting inflammation, and mobilizing the limb early are key parameters to assure return of function during the acute phase of injury. Although children may present with neglected contractures at a later date, even grade IV contractures can be surgically approached with hopes of improving hand function. Loss of the thumb in children with very large total body surface area burns can be approached reliably by lengthening of the thumb using first-to-second metacarpal transfers, as described by Littler. Although electrical injuries represent only a small fraction of patients admitted to our hospitals, children who present with viable insensate hands can have reliable sensory return more than 1 year after injury using nonvascularized cable nerve grafts if soft tissue coverage is adequate. As surgical procedures continue to evolve in delayed reconstruction of the hand, one would expect children to show better results than those seen in adult patients. A more aggressive surgical approach, with increased optimism, therefore is required when addressing children with complex hand burns requiring reconstruction.

Elevated interleukin-6 expression in keloid fibroblasts.

Keloids are characterized by a net accumulation of collagen. To date, the role of growth factors and various cytokines in the pathogenesis of these lesions has not been fully characterized. Interleukin-6 (IL-6) is an important immunoregulatory cytokine that has been implicated in a number of fibrotic autoimmune diseases such as scleroderma, interstitial nephritis, and pulmonary interstitial fibrosis. However, the role of IL-6 in the development of keloids has yet to be defined. This study demonstrates increased expression of the IL-6 gene in fibroblasts isolated from patients with keloids when compared with control fibroblasts using the ribonuclease protection assay. Subsequent detection of increased levels of IL-6 secretion by keloid fibroblasts is also demonstrated under unstimulated and stimulated conditions using serum and interferon gamma (IFN-gamma) (unstimulated: 0.3694 + 0.2499 pg/cell vs 0.0662 + 0.0786 pg/cell, P = 0.0137; serum: 1.066 + 0.513 pg/cell vs 0.233 + 0.231 pg/cell, P = 0.0027; serum and IFN-gamma: 1.286 + 0.395 pg/cell vs 0.244 + 0.199 pg/cell, P < 0.0001). These results suggest that IL-6 may play a significant role in the pathogenesis of keloids.

Altered interleukin-6 expression in fibroblasts from hypertrophic burn scars.

Hypertrophic burn scars (HBSs) are characterized by a net accumulation of collagen. The role of growth factors and various cytokines in the pathogenesis of these lesions has not been fully characterized. Interleukin-6 (IL-6) is an important immunoregulatory cytokine that can affect fibroblast function. This study showed increased expression of the IL-6 gene in fibroblasts isolated from patients with HBSs compared with control fibroblasts when the ribonuclease protection assay was used. A subsequent increase in unstimulated and stimulated IL-6 secretion was noted in HBS fibroblasts compared with normal control fibroblasts (unstimulated, 0.3627+/-0.2017 pg/cell vs 0.0662+/-0.0786 pg/cell, P = .0054; serum, 0.770+/-0.523 pg/cell vs 0.233+/-0.231 pg/cell, P = .0381; serum and interferon-gamma, 0.912+/-0.650 pg/cell and 0.244+/-0.199 pg/cell, P = .0327). These results are further evidence of the role of inflammatory cytokines in the development of HBSs.

Infestations and chronic infections in foreign pediatric patients with burns: is there a role for specific protocols?

Infestations by parasites such as Mycobacterium tuberculosis and other viral infections are common in third world countries. Consequently, the admission of a significant number of foreign patients to burn centers in the United States may pose new problems, not only for inpatients but also for health care workers. To document infestations in patients from third world countries and to determine the need for specific protocols, we studied 62 consecutive foreign patients admitted to our pediatric burn reconstruction service between July 1997 and December 1998. All patients were evaluated with chest X-ray, hemogram with differential count, clinical and laboratory nutritional assessment, and skin test for tuberculosis, and stool samples were evaluated for ova and parasites. No pathologic findings were seen on chest radiographs. Only 1 patient had a positive skin test for tuberculosis, as a result of previous bacille Calmette-Guérin vaccine. Yet, 10 patients (16%) had positive stool cultures for ova and parasites that contained 29 isolates. The most frequently identified organism was Blastocystis hominis. All amoebas identified were nonpathogenic according to Centers for Disease Control criteria. Ascaris lumbricoides and 1 case of cysticercosis were found. None of the patients with parasites had clinical manifestations of parasitosis or chronic infections. However, parasite infestations had a positive correlation with eosinophilia, altered nutritional status, and altered mean corpuscular hemoglobin concentration, as defined by multiple linear regression. Although foreign patients admitted to burn centers from third world countries have a low rate of infestations, patients at risk can be identified by laboratory findings and studies of nutritional status. Simple hand washing prevents the spread of disease and protects health providers.

Are your thoughts of facial pressure transparent?

Facial burns present many psychological and rehabilitation challenges. Many of our patients with facial burns who are children and adolescents have expressed that they prefer to wear the transparent face mask instead of the Jobst hood (Beiersdorf Jobst Inc, Charlotte, NC) with an underlying silicone face pad. However, questions have been raised about the consistency and amount of pressure provided by the transparent face mask. Pressure was measured under the customized transparent face mask, under the customized silicone face pad with a Jobst hood, and under the customized Jobst hood to ascertain pressure differences for a single patient. No significant difference in pressure was observed between the transparent facemask and the silicone face pad with a Jobst hood. We recommend the use of the transparent face mask on patients with severe facial burns who may require pressure to improve the appearance of their scars.

Dural reconstruction of a class IV calvarial burn with decellularized human dermis.

Calvarial burns involving the brain (Class IV) are reported to be rare. They represent a treatment challenge. Wound coverage can be accomplished with serial debridement of bone and grafting over granulating tissue, local flaps and free tissue transfer. The former techniques are often not feasible in the young infant. We present a successful case of a six-week-old female patient affected of full thickness burns involving the skull and brain. The bone, dura mater and superficial brain were debrided and the defect covered with AlloDerm and split thickness grafts. The area engrafted completely and no complications or CSF leak occurred. An acellular human allogeneic dermis (AlloDerm) can be successfully used to replace dura mater in burn patients.

Cadaveric skin allograft-associated cytomegalovirus transmission in a mouse model of thermal injury.

As a routine procedure to provide temporary coverage for burn wounds, cadaveric skin allografts have been used in patients with massive thermal injuries. In this study, CMV infection associated with skin grafting was investigated. Graft-associated CMV transmission was shown in a mouse model of thermal injury. Skins from mice 100 days after a nonlethal dose of murine CMV (MCMV) infection contained MCMV DNA and mRNA, although the virus was not isolated from these murine skins. When these skins were grafted to burned mice, the marked growth of MCMV was demonstrated in salivary glands. No viral growth was shown in the salivary glands of unburned mice or CMV sero(+) mice after grafting with these skins. When severe combined immunodeficient beige (SCID-beige) mice were used as recipients for CMV sero(+) skins, all mice died within 30 days after the grafting. Only 1 PFU/mouse of MCMV was shown to be 1 LD(50) in SCID-beige mice, while a 50% mortality rate was shown in normal unburned mice infected with 5 x 10(5) PFU/mouse of MCMV. This indicates that a very small amount of CMV contained in skins is sufficient to induce CMV infection in immunocompromised hosts. On the other hand, human CMV (HCMV) DNA and mRNA were detected by PCR analysis in 55% (DNA) and 33% (mRNA) of cadaveric skins, although the isolation of HCMV from cadaveric skin homogenates was not achieved in tissue cultures. CMV sero(-) patients with severe burn injuries may have a high risk for CMV infection associated with allografts of cadaveric skins.

Cellulitis associated with burn scars: a retrospective review.

This retrospective study evaluated 55 patients with burn scar cellulitis who required hospital readmission from January 1977 to July 1994. The overall incidence of burn scar cellulitis was 1.6%, and it was highest among patients who had undergone fascial excision (17.1%) as compared to those who had undergone tangential excisions (1.5%), or those who received nonoperative therapies (0.7%). Also, the use of meshed graft 4:1 for wound coverage exhibited a higher incidence of scar cellulitis (17.1%) as compared to the use of 2:1 meshed graft (1.1%). Methicillin-sensitive Staphylococcus aureus was the most common offending organism (69%), so it was concluded that all patients should be treated initially with antibiotics having methicillin-sensitive staphylococcal coverage. The lower extremity was involved 80% of the time, and the most commonly affected age group was 11 to 15 years. All patients were healthy and displayed no vascular, immunologic, or neurologic compromise at the time of readmission.

Increased physiological dead space/tidal volume ratio during exercise in burned children.

Exercise testing enables the simultaneous evaluation of the cardiovascular and respiratory systems' ability to perform gas exchange. The physiological responses to exercise have not been previously reported in the postburn child. This investigation was designed to evaluate residual cardiopulmonary impairment in patients convalescing from severe burns. Spirometry, lung volumes and exercise stress testing were completed on 40 children with a mean time postburn injury of 2.6 +/- 1.9 years and mean burn size of 44 +/- 22 per cent TBSA. Respiratory variables studied during exercise included expired volume, tidal volume and respiratory rate, and physiological dead space/tidal volume (VD/VT) ratios. Stress testing revealed an increased VD/VT ratio consistent with uneven ventilation-perfusion relationships. The data indicate that patients who survive thermal injury may not regain normal cardiopulmonary homeostasis.

Cytoprotection of human dermal fibroblasts against silver sulfadiazine using recombinant growth factors.

Topical antimicrobial agents, silver sulfadiazine (SSD) and mafenide acetate (MA), have been associated with delayed wound healing. Previous in vitro studies with human dermal fibroblasts (HDF) have shown progressive cellular cytotoxicity with increasing concentrations of SSD and MA. However, preexposure of HDF to epidermal growth factor, basic fibroblast growth factor, or platelet-derived growth factor has resulted in cytoprotection of HDF against 0.01 and 0.03% concentrations of SSD as determined by phase-contrast microscopy (PCM), hemocytometer cell counts, and total cellular protein content. PCM, however, showed slower destruction of HDF at the 0.05% concentration of SSD. These data suggest that cells activated by growth factors either take up less SSD or are more resistant to the direct cytotoxic effects of this drug.

Reconstructive management of patients with greater than 80 per cent TBSA burns.

With improving acute burn care, greater numbers of patients are surviving large burns. Meshed skin grafts or cultured epithelial autografts are often required to achieve rapid wound closure, even in areas such as the hands or face. This, plus the lack of suitable donor tissue for reconstruction, is mandating a change in reconstructive principles. Twenty-eight patients surviving > or = 80 per cent TBSA full skin thickness burns were evaluated using two specially devised instruments (Inventory of Potential Reconstructive Needs; Donor Tissue Surveillance). A total of 564 reconstructive needs were identified in the 28 patients, an average of 20.1 per patient. There were 265 defects in the head and neck, 143 in the upper extremities, and 156 in the torso/lower extremities. The injured anatomical units most frequently identified were the hand (74), trunk (60), nose/nasolabial fold (48), mouth (46), ankle/foot (42), neck (31) and check (28). The Donor Tissue Surveillance form revealed that the necessary donor tissue was frequently not available, and when available, was often of poor quality. These facts require a different set of priorities for reconstruction of the massively burned patient. No longer can a simple stepwise plan of active function, passive function, and aesthetic needs be followed. The patient and family desires must be combined with a realistic outlook by the entire burn team to determine the most judicious and efficient use of available donor tissue to meet the reconstructive needs.

Temperature changes during exercise stress testing in children with burns.

It has been postulated that because of the extensive destruction of the skin and appendages after thermal injury, the thermoregulatory control mechanism would be impaired, and these patients would be intolerant to prolonged work. Preview studies demonstrate evidence that during work in a hot climate, patients with an extensively healed burn react with an excessive rise in body temperature. This study was designed to investigate the thermoregulatory response to exercise in pediatric patients with burns and to study changes in body temperature during exercise testing. Cardiopulmonary stress tests were completed in 32 children with a mean postburn time of 2.3 +/- 1.5 years and a mean burn size of 44% +/- 23% total body surface area. Exercise variables included expired volume, tidal volume, respiratory rate, tidal/dead space rate, heart rate, and work stage achieved. Temperature monitoring included external auditory canal temperature, burn scar, and normal skin temperature. Values were measured at baseline during and at maximum exercise. Our data indicate all patients reached the same endurance level regardless of the size of the total body surface area burn. Additionally, in a temperature-controlled environment, adequate heat dissipation in children with burns can be maintained during exercise testing without an excessive rise in body temperature.

Sleep disorders in children after burn injury.

Eighty-two children and adolescents between the ages of 30 months and 20 years (mean, 11.8 years) who were admitted to one of two pediatric burn units with a mean initial burn injury of 43.8% total body surface area and a mean age at time of injury of 4.2 years were studied 1 year or more after burn injury (mean, 7.3 years). Subjects were found to have profound at-home sleep disorders, which were manifested as nightmares in 30 subjects (37%), bed-wetting in 20 (24%), and sleep-walking in 6 (18%). Dream content related to normal childhood topics in 45 patients (55%), burn injury in 6 (7%), and burn treatment in 5 (6%). No relationship exists between age at time of burn, length of time after burn injury, cause of burn injury, family history of nightmares, or patient history of bed-wetting and the incidence of nightmares. Daytime naps were reported in 50 subjects (63%), although 46 (mean age, 11.7 years) were well beyond the normal age for napping.

Reconstruction of foot burn contractures in children.

Burn scar contractures of the foot cause significant morbidity. We reviewed 68 children in regard to number and rates of burn scar contracture recurrence, surgical techniques, and functional and aesthetic results. Two surgical techniques of foot burn scar contracture release have been used. Originally, an incision over the metatarsal heads perpendicular to the line of the metatarsals, which releases the longitudinal arch of the foot was used. More recently, additional releasing incisions parallel to the plane of the metatarsals to release the transverse metatarsal arch have been used. The time between burn injury and primary burn scar contracture release was 4.18 +/- 0.76 years, and the time until the first recurrence was 3.44 +/- 0.46 years. With release of only the longitudinal arch, recurrence of burn scar contractures occurred in 3.5 +/- 0.41 years and in 4.29 +/- 1.27 years in six patients who also received release of the transverse arch. Wound closure at the time of acute burn with split-thickness skin graft expansion ratios of 1:2 and 1:4 had burn scar contractures that required release in 4.21 +/- 0.70 and 2.29 +/- 0.52 years, respectively.