The availability of allograft skin for large scale medical emergencies in the United States.

Mass injury events present a unique medical challenge. Effective communications and coordination of resources including trained personnel as well as supplies and equipment are critical in these emergent situations. In the U.

Acellular human dermis promotes cultured keratinocyte engraftment.

In full-thickness skin injury, loss of dermis may result in compromised wound repair, including contracture, hypertrophic scarring, and wound breakdown. This report examines the effect of an acellular dermal matrix on in vivo skin repair. Human keratinocytes cultured onto a synthetic hydrophilic dressing were applied with (N = 9) and without (N = 11) an acellular dermal matrix to full-thickness skin defects on athymic mice.

Burn injury results in decreased gastric acid production in the acute shock period.

Gastrointestinal complications including acute stress ulcerations occur after burn injury. The causes of acute gastric derangements are multiple, and tissue ischemia in the acute period of burn shock may promote breakdown of the gastric mucosal protective barrier. We compared gastric pH in mice after 25% total body surface area, full-thickness murine burn injury with that in unburned control animals.

Effects of high-dose vitamin C administration on bacterial translocation and lung neutrophil sequestration in burned mice.

Severe burn injury produces shock and induces acute gastrointestinal derangements that may disrupt mucosal integrity and facilitate bacterial translocation (BT) to mesenteric lymph nodes, accompanied by endotoxemia. Antioxidant treatments may be beneficial after shock by acting as scavenger agents for highly reactive oxygen intermediates. We studied the effects of high dosages of vitamin C, a water-soluble antioxidant, on the incidence of BT and on levels of lung myeloperoxidase in burned mice.

Effects of small-volume bolus treatment with intravenous normal saline and 7.5 per cent saline in combination with 6 per cent dextran-40 on metabolic acidosis and survival in burned mice.

Standard murine burn models include the administration of intraperitoneal (i.p.) saline solutions which are intended to resuscitate the animals during subsequent burn shock.

Ultrastructural features of composite skin cultures grafted onto athymic mice.

Skin substitutes composed of cultured keratinocytes with or without a dermal substrate are now being used in the treatment of burns and other cutaneous wounds. Composite skin cultures (Graftskin, LSE), consisting of epidermal keratinocytes seeded on a fibroblast-containing collagen matrix and maintained at the air-liquid interface, develop a well differentiated epidermis in vitro with many of the morphological and biochemical features of intact skin. Basement membrane-associated antigens, developing hemidesmosomes and short segments of lamina densa are present at the dermal-epidermal junction in vitro, although the LSE lacks a continuous basement membrane.

Current trends in the use of allograft skin for patients with burns and reflections on the future of skin banking in the United States.

Cadaveric allograft skin can play a critical role in the care of patients with massive burns. It is difficult, however, to estimate current use and levels of enthusiasm for allograft skin in the United States. We report on a survey of 40 skin banks and 140 United States burn center medical directors as listed in the American Burn Association's Directory of Burn Care Resources for North America 1991-1992.

Evaluation of Graftskin composite grafts on full-thickness wounds on athymic mice.

We used a living bilayered cultured skin replacement to close full-thickness wound defects on the dorsum of athymic mice. The skin replacement is composed of human fibroblasts that condense a bovine collagen lattice; the lattice is then seeded with cultured human keratinocytes. The collagen lattice with fibroblasts serves as a dermal template, and the overlying human keratinocytes form the epidermal component of this composite skin replacement.

Development of a temporary living skin replacement composed of human neonatal fibroblasts cultured in Biobrane, a synthetic dressing material.

Background: Preferred coverings for excised burn wounds when sufficient autograft skin is not available are fresh or cryopreserved cadaveric skin. Problems with supply, preservation, immune rejection, and potential infection transmission accompanying the use of allograft skin underscore the need for effective alternative temporary skin replacements.

Methods: We cultured human neonatal fibroblasts (HF) for 4 to 6 weeks in nylon mesh of Biobrane, a synthetic dressing consisting of a thin layer of silicone bonded to nylon mesh.

Reduction of bacterial translocation and intestinal structural alterations by heparin in a murine burn injury model.

Burn injury produces acute gastrointestinal (GI) derangements that may predispose the burn victim to bacterial translocation (BT). We studied the effects of heparin on gastrointestinal (GI) anatomic alterations and BT after 25% and 32% total body surface area (TBSA), full-thickness murine burn injuries. Heparin (100 U/kg) was administered with 1 mL of normal saline (NS) resuscitation solution immediately postburn and 4 hours and 18 hours postburn in volumes of 0.

Effects of fluid resuscitation, burn eschar excision, and blockade of afferent pain responses on bacterial translocation and acid-base balance after murine burn injury.

We tested effects of fluid resuscitation, early burn excision/grafting, and blockade of afferent stimuli from the burn wound on bacterial translocation and acid-base balance after murine burn injury. Burn excisions were performed with patients either 15 minutes or 2 hours after burn injury under anesthesia, and excised wounds were immediately closed with murine allograft skin. Twenty-four hours after 25% total body surface area (TBSA) burn injury and 48 hours after 32% TBSA injury, mesenteric lymph nodes were cultured.

Composite grafts of human keratinocytes grown on a polyglactin mesh-cultured fibroblast dermal substitute function as a bilayer skin replacement in full-thickness wounds on athymic mice.

We have developed and tested in athymic mice a new, cultured, dermal-epidermal graft composed of two human cell types coupled with a biodegradable dermal scaffold. Cultured, proliferating human keratinocytes (HK) were applied to the surface of a living dermal tissue replacement that is composed of human fibroblasts cultured on a polyglactin mesh. After 4 to 6 days of coculture, proliferating HKs achieved confluency on the surface of the living dermal tissue replacement.

Effect of corticotropin releasing factor on acid-base alterations and bacterial translocation in a murine model of thermal injury.

Corticotropin-releasing factor (CRF) is a 41 amino acid polypeptide produced by the hypothalamus which has been shown to decrease inflammation and tissue oedema when administered following burns, cold and acid injuries in some animal models, and to increase mesenteric blood flow. We determined whether systemic administration of CRF to burned mice would decrease metabolic acidosis and protect the gastrointestinal (GI) tract from ischaemic injury leading to bacterial translocation (BT). Synthetic CRF was administered by intraperitoneal injection in doses of 20 and 200 micrograms/kg to mice immediately following 25 and 32 per cent TBSA burn injuries; the doses were repeated at 8 and 16 h postburn.

Development of a device for measuring adherence of skin grafts to the wound surface.

Adherence of a biological graft to the wound surface is the most important factor influencing the ultimate success of graft viability. A machine has been developed to test the adherence of biological graft materials to a substrate such as a wound surface. The peeling mode, which yields reproducible quantitative measurements of adherence, is a standard method for testing adhesives.

Evaluation of a biodegradable matrix containing cultured human fibroblasts as a dermal replacement beneath meshed skin grafts on athymic mice.

Meshed, expanded split-thickness skin grafts (MSTSG) frequently achieve poor results when used to cover full-thickness wounds. Poor cosmetic and functional results occur in part because the epithelium that grows across the skin graft interstices lacks a dermis. We used a living dermal replacement composed of either polyglycolic acid (PGA) or polyglactin-910 (PGL) mesh containing confluent, cultured human fibroblasts.

Microbial contamination in allografted wound beds in patients with burns.

Microbial wound contamination has been recognized as a cause of autograft skin graft failure. Human cadaver allograft is believed to decrease or control microbial wound contamination, and by its adherence to the wound bed, to indicate a sufficiently low microbial count to allow successful application of autograft. Suboptimal "take" of more fragile cultured skin grafts after removal of adherent allograft led us to reexamine the microbial population of these wound beds.

Cyclosporine A for prolonging allograft survival in patients with massive burns.

Cyclosporine A (CsA) immunosuppression was used in three patients with massive burns to prolong skin allograft survival. Cyclosporine A kinetic studies in patients with burns revealed markedly accelerated blood clearance and high variability in drug absorption when compared with studies in renal transplantation patients. Doses required to maintain therapeutic levels varied widely.

Reversal of diabetic somatic neuropathy by whole-pancreas transplantation.

To answer the crucial question regarding reversibility of diabetic somatic neuropathy by whole-pancreas transplantation, metabolic studies and electron microscopic morphometry of the sciatic and testicular nerves were performed monthly for 2 years in three groups of highly inbred rats: (1) NC, 47 nondiabetic controls; (2) DC, 90 untreated alloxan-induced diabetic controls; and (3) DT, 230 diabetic rats given syngeneic pancreaticoduodenal transplants 6, 9, 12, 15, 18, and 21 months after induction of diabetes mellitus (DM). Six diabetic nerve lesions were quantitated by a "blind" protocol: (1) loss of myelinated axons, (2) intraaxonal glycogen deposits, (3) axons with glycogen deposits, (4) demyelinated axons, (5) degenerating axons, and (6) loss of intact axoglial junctions in paranodal terminal myelin loops. In the DT group, testicular nerve specimens were obtained just before transplantation and at death so that each animal served as its own control.

Effect of pancreas transplantation on diabetic somatic neuropathy.

To determine whether pancreas transplantation is capable of preventing diabetic somatic neuropathy, metabolic studies and electron microscopic morphometry of the sciatic nerve were performed monthly for 2 years in four groups of highly inbred rats: (1) NC-28 nondiabetic controls; (2) DC-82 untreated alloxan-diabetic controls; (3) WPT-122 diabetic rats that received a syngeneic whole-pancreas transplant; and (4) IT-90 diabetic rats that received intraportal injections of 1500 to 2000 syngeneic pancreatic islets. Five diabetic nerve lesions were quantitated by a "blind" protocol: intra-axonal glycogen deposits, axons with glycogen deposits, demyelinated axons, intact axoglial junctions in paranodal terminal myelin loops, and basal lamina thickness of vasa nervorum. Untreated diabetic control animals had significant and progressive increases in all five nerve lesions compared to nondiabetic controls (p less than 0.

Comparison of the metabolic control of diabetes achieved by whole pancreas transplantation and pancreatic islet transplantation in rats.

To compare the long-term effectiveness of whole pancreas transplantation and pancreatic islet transplantation in controlling the metabolic disorders of alloxan diabetes, metabolic studies were performed monthly for 2 years in 4 groups of highly inbred rats: (1) NC-116 nondiabetic controls; (2) DC-273 untreated alloxan-diabetic controls; (3) PDT-182 rats that received syngeneic pancreaticoduodenal transplants shortly after induction of diabetes with alloxan; and (4) IT-92 rats that received an intraportal injection of at least 1500, but usually 2000, syngeneic pancreatic islets shortly after induction of diabetes with alloxan. Whole pancreas transplantation maintained strict metabolic control throughout the 2 years of study. In group PDT, hyperglycemia was abolished; plasma glucose concentration was maintained tightly within the normal range; markedly depressed plasma insulin levels were raised to above normal; glucose tolerance tests had insulin levels above normal and glucose levels that increased less and declined more rapidly than normal; and body weight gain and growth approached normal.

Comparison of whole pancreas and pancreatic islet transplantation in controlling nephropathy and metabolic disorders of diabetes.

To compare the long-term effectiveness of whole pancreas transplantation and pancreatic islet transplantation in controlling the metabolic disorders and preventing the kidney lesions of alloxan diabetes, metabolic and morphologic studies were performed in four groups of rats: (1) NC-116 nondiabetic controls; (2) DC-273 untreated alloxan-diabetic controls; (3) PDT-182 rats that received syngeneic pancreaticoduodenal transplants not long after induction of diabetes with alloxan; and (4) IT-92 rats that received an intraportal injection of at least 1500 and usually 2000 syngeneic pancreatic islets soon after induction of diabetes with alloxan. Each month for 24 months after diabetes was well established, body weight and plasma concentrations of glucose and insulin were measured, and five lesions were scored by light microscopy in 50 glomeruli and related tubules in each kidney by a "blind" protocol: glomerular basement membrane thickening, mesangial enlargement, Bowman's capsule thickening, Armanni-Ebstein lesions of the tubules, and tubular protein casts. There were progressive and highly significant increases in the incidence and severity of all five kidney lesions in the diabetic control rats compared with the nondiabetic control rats.

Lifelong reversal of the metabolic abnormalities of advanced diabetes in rats by whole-pancreas transplantation.

Evidence suggests that metabolic abnormalities are responsible for the widespread microvascular complications of insulin-dependent diabetes mellitus (IDDM). Interest in endocrine pancreas replacement therapy, including pancreas transplantation, is based on the hope that such treatment will reverse the complications of IDDM by providing more precise metabolic control than conventional therapy. To determine if whole pancreas transplantation is capable of reversing well-established metabolic abnormalities of diabetes mellitus (DM) and maintaining strict metabolic control for life, we performed monthly metabolic studies for 2 years in 141 nondiabetic control rats, 273 diabetic control rats with alloxan-induced DM, and 267 diabetic rats that received syngeneic whole pancreaticoduodenal transplants 6, 9, 12, 15, 18, and 21 months after induction of DM with alloxan.

Reversal of mesangial enlargement in rats with long-standing diabetes by whole pancreas transplantation.

An important unanswered question about clinical use of pancreas transplantation is: can pancreas transplants reverse or, at least, stabilize well-established lesions of insulin-dependent diabetes mellitus (IDDM)? To answer this question, we performed whole pancreas transplantations in 190 highly inbred rats 6, 9, 12, 15, 18, and 21 mo after induction of diabetes mellitus (DM) with alloxan. We then studied the effect on renal mesangial enlargement (ME) for 24 mo after onset of DM by a quantitative morphologic technique in which camera lucida tracings of the mesangium were made at X 1250 and were analyzed using an electronic planimeter connected to a calculator/computer. A pretransplant kidney biopsy was obtained so that the rats served as their own controls.