Unburned Skin Research Articles

Feeding gastrostomy for the severely burned patient.

Twenty-two patients underwent feeding gastrostomy. Their ages ranged from 17 to 76 years. Their burn injuries were extensive, ranging from 31% to 88% total body surface area, with a mean of 60%. Nine gastrostomies were done through intact unburned skin, 12 were done through the burn wound itself, and one was done through a split-thickness skin graft donor site. No evidence of intraperitoneal or wound infection was observed. No intraoperative and only three postoperative complications were encountered. One patient had a wound dehiscence while in the hospital. Following discharge from the hospital, two other patients manifested incisional hernias. Initially, we were reluctant to consider this operative procedure for our patients because of anticipated intra-abdominal and wound complications. In view of our experience thus far, however, we are now more confident of the procedure.

Characterization of the immunosuppressive effect of burned tissue in an animal model

The immunosuppressive effect of burned tissue was studied using a mouse burn model. To evaluate the immunologic status an in vivo measure of cell-mediated immunity (CMI) involving contact sensitization of mice by painting the skin with dinitrofluorobenzene was used; mice were challenged 5 days later by painting the ear with the same antigen. Ear swelling in response to antigenic challenge was used as a quantitative measure of CMI; diminution in ear swelling in treatment mice compared to sensitized, unburned control mice indicated the degree of immunosuppression. A full-thickness steam burn covering 20% body surface ares (BSA) was profoundly immunosuppressive as reflected by ear swelling of 45 to 60% of that found in normal mice; partial thickness burns and burns of 10% BSA extent were not significantly immunosuppressive. Transfer into unburned mice of burned skin equivalent in size to a 20% BSA burn eschar resulted in marked immunosuppression, but transfer of smaller amounts of burned skin, or of larger amounts of unburned skin and normal and burned liver tissue, did not produce immunosuppression. Mice receiving a very high-temperature (300°C), dry burn were only slightly more suppressed than mice receiving a standard steam burn. Normal immunity was preserved in burned mice which received daily application of cerium nitrate to the wound for 7 days, but application of other topical agents commonly used in burn treatment did not preserve immunity. Postburn immunosuppression thus appears related quantitatively to toxic factors in burned skin, and these toxic factors can be abrogated in burned mice by the topical application of cerium nitrate.

Evaluation of the burn wound with perfusion fluorometry.

Determination of depth of burn injury using vital dyes has been unsatisfactory. The present study evaluated the ability of the fiberoptic perfusion fluorometer to assess the depth of burn in the early postburn period. Sixty-three burns were examined with the fluorometer after intravenous administration of sodium fluorescein. The fluorescein kinetics were monitored for 1 hour within the first 48 hours and again between the third and sixth days postburn. The rate of fluorescein uptake and burn wound fluorescence was determined and compared to that of normal unburned skin. Depth of burn was confirmed by biopsy and healing characteristics. Fluorometric analysis during both study periods consistently distinguished between partial-thickness and full-thickness burns. Partial-thickness burns uniformly exhibited fluorescence within 10 minutes; full-thickness burns showed nil fluorescence. None of the patients experienced a change in skin color or complications from the small dose of fluorescein given.

Linoleic acid in hypertrophic scars

The relative proportions of the five major fatty acids present in the epidermal polar lipids isolated by swabbing the surface of the skin over hypertrophic scars were compared with the relative proportions observed in normal skin. This comparison necessitates taking the ‘normal’ sample from unburned skin in an anatomically equivalent area on the patient investigated. When pairs of samples obtained at random from 25 patients attending a pressure therapy clinic with scars of widely differing maturity were analysed, 16 of the 27 sample pairs showed lower levels of essential fatty acid (linoleic acid, C18 : 2) in phospholipids from over the scarred area compared with the ‘area-matched’ control normal sample. There did not appear to be any scar-age-related variation in essential fatty acid content. The results suggest that the pathogenesis of hypertrophic scar formation does not necessarily involve a simple overall deficiency of linoleate but that there are considerable differences in the lipid content of epidermis over hypertrophic scars and that of normal skin.

Depressed reflex vasomotor control of the burn wound.

Total leg blood flow was measured by venous occlusion plethysmography in five normals and 14 burned patients before and after 30 min of external heating. Leg surface temperatures were held constant, but rectal temperatures increased on the average of 0.4 to 0.5 degrees C in all subjects following this heat load. Leg blood flow increased by 56.0% in the controls, 63.2% in five patients with essentially no leg burn (mean burn size = 1.5% leg surface), and 9.6% in nine patients with major leg injuries (mean burn size 55% leg surface). Failure of reflex vasodilatation in the burned leg was evident up to 107 days postinjury even when the wound was well-healed. All subjects sweated freely from the unburned skin. In two patients, where arm and leg blood flows were measured simultaneously, flow to the uninjured arm increased while that to the injured leg remained unchanged. This lack of reflex vasodilatation in the burned limbs suggests either that wound vessels are denervated or that they are so dilated in the basal state that further dilatation is limited. The bulk of this and other data would support the denervation concept. This physical or chemical denervation could occur at the time of injury, be localised to the area of the wound, and result in loss of both neurogenic vasoconstrictor tone and active reflex vasodilatation.

Cold-water treatment of scald injury and inhibition of histamine-mediated burn edema

Using the hairless mouse ear burn model we have studied the effects of immediate short-term cold-water treatment (CWT) of a moderate scald injury (54°C water for 20 sec) to intact skin using 8–10°C water for 5 min. CWT following scald injury caused brief periods of arteriolar vasomotion and shortened the duration of postburn venular dilation by about 50% as compared to untreated burns. CWT significantly ( P < 0.05) reduced edema formation of the burned ear for only the first 2 hr after injury as compared to untreated burns. Significant delayed remote edema formation normally observed in abdominal and unburned (contralateral) ear skin after untreated ear scald injury was abolished after CWT to the burned ear. Chemical inhibition of remote burn edema, comparable to that achieved with CWT, was produced by cimetidine pretreatment or histamine depletion prior to injury. CWT also significantly decreased tissue histamine loss of the burned ear after scald injury Ultrastructural demonstration of increased vacuole formations in capillary and venular endothelial cells in edematous, unburned ear skin 2 hr after untreated scald injury suggested the presence of histamine-mediated remote burn edema formation. Predominant pathophysiologic mechanisms of CWT in local and remote burn edema inhibition and perhaps burn shock protection were suggested as: (1) decreased vascular response with a shortened duration of postburn venular dilation, and, most importantly, (2) the inhibition of local and systemic histamine release from thermally injured tissues.

Chemical Debridement of Burns

Experiments were conducted using non-enzymatic chemical agents (with emphasis on certain mercaptans), alone, in conjunction with enzymatic agents and/or other nonenzymatic chemicals for debridement of burns. Both in vitro (rats, pigs, humans) and in vivo (rats, pigs) tests were carried out. N-acetylcysteine, penicillamine and cysteine ethyl ester in low to moderate concentrations accelerate the debriding action of bromelain (an enzymatic preparation from pineapple stems) and in higher concentrations, N-acetylcysteine and penicillamine (cysteine ethyl ester was not tested) cause ready separation of the burn eschar from the underlying tissue before solubilization of the eschar is complete (rat) or has occurred (pig). Debridement of 3 degree burns of rats is complete within 4-6 hours; the take of immediately applied syngeneic skin grafts is complete and permanent. This is first time rapid debridement of 3 degree burns permitting immediate successful skin grafting has been accomplished with known defined chemicals. In pigs there is softening of the 3 degree burn eschar by N-acetylcysteine but little, if any, dissolution of the eschar. However, mechanical separation of the eschar from the underlying tissue is accomplished readily with a wooden throat stick with no bleeding. There is a change in color of the superficial layer of the underlying subcutaneous tissue from yellow-light brown to dark brown-black. The debrided areas begin to granulate promptly. The healing of deep dermal burns of pigs is hastened by the application of N-acetylcysteine for a day (beginning 24 hours after burning) while the healing of moderately deep dermal burns is not modified. Unburned skin is not damaged. There is no apparent systemic toxicity associated with the use of N-acetylcysteine for debridement of 10-15% b.s.a. 3 degree burns of rats or 15-20% b.s.a. 3 degree burns of pigs. Major emphasis has been on N-acetylcysteine because of the potential adverse secondary effect of penicillamine and cysteine ethyl ester; N-acetylcysteine is readily metabolized. The use of a keratolytic agent prior to the application of N-acetylcysteine hastens the latter's action. Sulfamylon and sulfadiazine can be used with N-acetylcysteine without interfering with its debriding action. The effects of the mercaptans are likely due largely to their ability to depolymerize connective tissue proteoglycans and proteins, especially at the interface between living and dead tissue.

Effect of methylprednisolone on oedema formation after a major burn

The mechanism of oedema formation distant from a burn site is only partially explained by an increase in capillary permeability. It has been demonstrated in quantitative terms that after a major burn, there is a large number of white blood cells (WBCs) stuck to the walls of venules in the distant microcirculation. Theoretical calculations predict a corresponding increase in post-capillary resistance, suggesting that WBC-sticking is partly responsible for oedema formation. In an attempt to discover whether the theoretical calculations persisted in vivo , the number of sticking WBCs in the mesenteric microvasculature of rats was determined at various times up to 48 h after a full-thickness scald burn to the back. The quantitative oedema formed was assessed by the wet weight/dry weight technique in burned skin, unburned skin, skeletal muscle and lung tissue. Half of the rats received methylprednisolone sodium succinate prior to burning to determine its effect on WBC-sticking and oedema formation. Conclusions from the experiment showed that a 30 per cent body surface, full-thickness burn results in significant increase in WBC-sticking in mesenteric microcirculation in animals. Pretreatment with systemic methylprednisolone sodium succinate decreased the magnitude of this change. Pretreatment with methylprednisolone was not effective in reducing oedema formation to statistically significant levels, although pretreated animals consistently showed less oedema formation than those which were untreated. Correlation between the number of adherent WBCs in the mesenteric microvasculature and the quantity of oedema formed could not be demonstrated in this model.

Use of the Y-Body for Identification Of Skin Source On A Successfully Grafted Burn Patient

The use of the interphase male Y-body (fluorescent Y chromosome segment) technique with cryostat sections of both fresh and frozen-stored skin biopsies is described. A female burn patient appeared to retain her donor homografts, thereby negating the need for autografts. Since a retained homograft of this sort challenged our understanding of immunologic barriers, we applied the Y-body technique to cutaneous biopsies obtained from the patient's burn area that had been homografted with skin from a male donor, as well as control biopsies from the patient's unburned skin and normal control male and female skin. Based on clinical and cytogenetic observations, it was concluded that the most reasonable explanation for this case was that the regenerating tissue at the graft site was that of the recipient and not that of the originally grafted male skin.

The blister and the second degree burn in guinea pigs: the effect of exposure.

A reproducible partial-thickness burn was inflicted on 100 albino guinea pigs. With the blister intact, the evaporative water loss from the burn surface was essentially the same as from normal unburned skin. When the blister was removed, the rate of water loss was initially more than 100 times normal, and it remained 20 to 50 times the normal rate throughout the first week. This high rate of water loss was associated with an increasing depth of wound destruction (from dehydration) and a thickening of the overlying crust. Microscopic examination showed that previously viable dermis was incorporated in this crust. The depth of dermal loss was negligible when the blister was left intact, and improved healing resulted. We believe it is important to leave burn blisters intact, whenever possible.

Chemical debridement of burns.

The development of effective, non-toxic (local and systemic) methods for the rapid chemical (enzymatic and non-enzymatic) debridement of third degree burns would dramatically reduce the morbidity and mortality of severely burned patients. Sepsis is still the major cause of death of patients with extensive deep burns. The removal of the devitalized tissue, without damage to unburned skin or skin only partially injured by burning, and in ways which would permit immediate (or very prompt) skin grafting, would lessen substantially the problems of sepsis, speed convalescence and the return of these individuals to society as effective human beings, and would decrease deaths. The usefulness and limitations of surgical excision for patients with extensive third degree burns are discussed. Chemical debridement lends itself to complementary use with surgical excision and has the potential advantage over surgical excision in not requiring anesthesia or a formal surgical operation. The authors' work with the chemical debridement of burns, in particular the use of Bromelain, indicates that this approach will likely achieve clinical usefulness. The experimental studies indicate that rapid controlled debridement, with minimal local and systemic toxicity, is possible, and that effective chemotherapeutic agents may be combined with the Bromelain without either interfering with the actions of the other. The authors believe that rapid (hours) debridement accomplished by the combined use of chemical debriding and chemotherapeutic agents will obviate the possibility of any increase in infection, caused by the use of chemical agents for debridement, as reported for Paraenzyme(21) and Travase.(39,48) It is possible that the short term use of systemic antibiotics begun just before and continued during, and for a short time after, the rapid chemical debridement may prove useful for the prevention of infection, as appears to be the case for abdominal operations of the clean-contaminated and contaminated types.

Urinary hydroxyproline: source of increase after thermal burns.

SummaryThe collagen hydroxyproline (hypro) from burned skin, unburned intact skin, and carcass of thermally burned rats has been studied. The statistically significant decrease in burned skin hypro 8 and 16 days after burn suggests that the major source of urinary peptide hypro early after burns is from degradation of thermally denatured skin collagen. The finding of a new layer of hypro-rich connective tissue under the burn site on Day 16 suggests that later elevations of urinary hypro may result from breakdown products of newly synthesized collagen as well as degradation of collagen at the burn site.

Initial changes in burns: tissue changes in burned and unburned skin of rhesus monkeys

Initial changes in burns: tissue changes in burned and unburned skin of rhesus monkeys

Oxygen consumption in skin of experimentally burned rats.

Burns of approximately 15% of body area were inflicted on three series of white male rats. Time-temperature combinations were employed which produced leasions resembling a superficial second degree, a deep second degree and a third degree burn respectively.Oxygen consumption was measured by Warburg technique in burned and unburned skin at intervals of one hour, one week and two weeks post-burn.In a small number of animals oxygen consumption was studied in superficial parts of skin. In most animals deep parts (including some dermal tissue and panniculus carnousus) were examined by the same technique. Oxygen consumption was higher in the deep parts of skin.In the deep parts oxygen consumption one hour postburn was depressed sharply in the deep second degree burn (90°C for 5 sec) and zero in the third degree (90°C for 20 sec). However, it was increased in the superficial second (70°C for 5 sec). This may be due to qualitative changes caused by increased vascularity or to changes in the tissue mediated by pro...

Early burn wound changes

(1) There is a rapid and significant increase in water content of skin after standardized immersion burns in rats. This reaches a peak of 75 per cent above unburned skin values at 30 minutes, 90 per cent of this increase having been accomplished in the first 5 minutes. (2) There is a parallel increase in solid content after burning, reaching 64 per cent above control values at 30 minutes. (3) Tissue albumin content doubles in the immediate postburn period without subsequent later increase. (4) Red cell content of burn tissue increases rapidly, reaching a maximum of 520 per cent above unburned tissue values at 10 minutes, slowly declining thereafter. (5) The increase in tissue plasma and red cell content after burning is not enough to account for more than a small fraction of the increases in either water or solids. (6) Other factors must be responsible for the change in water content. Increased tissue osmolality secondary to the thermal injury might well be the primary factor in the early development of burn wound edema. (7) The source of increased tissue solids is not apparent.

Successful Control of Burn-Wound Sepsis

Over the past three years, the use of a topical antibacterial burn cream has resulted in the successful control of burn-wound sepsis. This pathological state, which is characterized by the proliferation and penetration of 100,000 (10⁵) or more microorganisms per gram of tissue, with extensive, active lymphatic invasion and may or may not be associated with generalized sepsis and widespread organ involvement, was the cause of death in 60% of patients dying at this unit prior to 1964. Histologically, this progression is characterized by bacterial invasion through the dermis into the subcutaneous tissue and may produce a typical<i>Pseudomonas</i>vasculitis with perivascular bacterial proliferation and invasion with thrombosis. The clinical manifestations of this disease are those of degeneration of the granulation tissue in areas of third-degree burn with violaceous, sharply demarcated wound edges, embolic ecthyma in unburned skin and tissues, ileus with abdominal distention, hypothermia, and leukopenia. Such bacterial

The use of unburned skin from burned animals as homografts with the adjunctive use of convalescent burn serum

The use of unburned skin from burned animals as homografts with the adjunctive use of convalescent burn serum

The use of unburned skin from burned animals as homografts with the adjunctive use of convalescent burn serum

Summary No experimental evidence has been found to support the belief that unburned skin homografts from unburned animals survive longer if applied to other burned animals. The adjunctive use of convalescent burn serum in no way altered the rejection of these homografts. There appears to be no clinical relationship between the homograft reaction and postburn immunologic changes.

Davidson tannic acid treatment of burns: Ten year results

The original paper of Davidson recommending tannic acid for burns outlined a treatment that has been changed but little in ten years' time. We believe that the spray method of 5 per cent tannic acid is the most convenient way of application. Any discussion that might arise as to the correctness of his statement of the theory of toxemia of burns should not be allowed to confuse the issue, as such tremendous improvement in the results has been reported. We should like to emphasize again as Davidson did the great importance of instituting immediately the best known and accepted means for the prevention of shock or the treatment of it, if present, when the patient is admitted. The ideal treatment must exclude all confusion and excitement in the room. Every effort to obtain the patient's confidence should be made, at the same time allaying apprehension. Sedatives, preferably morphine or codein, should be given at once as this is so effective in quieting fear. We believe that the room should be kept very warm, 90 ° or over. The foot of the bed should be elevated. First intravenous salt solution should be given and then transfusions of blood, after grouping has been determined. The technique of the preparation for and the application of tannic acid is here given as we practice it. Our method of procedure in the treatment of a burn case is as follows: 1. 1. Morphine or codein should be given at once. 2. 2. The grime of work is removed without undue scrubbing, using ether or benzine. 3. 3. The surrounding unburned skin area is thoroughly cleaned with soap and water. 4. 4. The blisters are widely opened under careful aseptic technique, using sterile instruments and sterile gloves, and the loose areas of skin are removed. The extent of the debridement and scrubbing must depend on the patient's condition. Too much manipulation may aggravate or produce shock. 5. 5. The patient is placed in bed on sterile sheets. 6. 6. The burned area is sprayed with a 5 per cent aqueous solution of tannic acid every fifteen minutes until a dark mahogany colored coagulum is obtained. This usually requires from ten to eighteen hours. 7. 7. A cradle to support the bed covers is placed over the patient. 8. 8. Sufficient electric lights are introduced between the covers to provide a temperature of 90 °. In addition to providing heat, the lights also aid in the drying process and therefore hasten the tanning. 9. 9. The greatest care is taken in the handling of these patients in their rooms and so far as technique is concerned one must treat them exactly as one would treat a surgical incision. 10. 10. The coagulum is allowed to remain in place until it frees itself and curls up at the edges as healing takes place, at which point it is cut away. 11. 11. Should serum collect underneath, as may occur when there has been complete destruction, or should infected fluid cause its loosening, the coagulum should be removed sufficiently to allow drainage and treatment. 12. 12. The denuded areas which are left after loosening and removal of the coagulum has taken place, should be immediately prepared and early skin grafting carried out. 13. 13. As soon as possible, after healing has taken place, physiotherapy should be instituted to increase function, if indicated. 14. 14. Should contractures occur in spite of all efforts to prevent them, plastic operations must be carried out to restore function.

Substitution of bromide and iodine for chlorine in the separation of cerium from the other cerium earths

We have previously demonstrated that CD34⁺ CD31⁺ immature myeloid cells (IMC) appearing in burn patients suppress antimicrobial peptide production by cultured human skin keratinocytes. In the present study, the effect of glycyrrhizin (GL) on the peptide production by unburned patient skin (skin removed for the auto-grafting surgery) transwell-cultured with CD34⁺ CD31⁺ IMC was examined. Using a lineage cell depletion kit and flow cytometry, CD34⁺ CD31⁺ IMC were isolated from peripheral blood of burn patients. Unburned patient skin tissues (4 x 4 mm) were transwell-cultured with various numbers of IMC for 1 to 7 days in the presence or absence of GL (Minophagen Pharmaceutical Co., Ltd., Tokyo, Japan). Culture fluids obtained were assayed for human β-defensin-1 (HBD-1) by ELISA. In the results, 1-5 ng/ml of HBD-1 were produced by unburned patient skin tissues 2 to 7 days after cultivation. When skin tissues were transwell-cultured with 1 x 10⁴ cells/ml of IMC syngeneic to the skin donors, 86% of HBD-1 production was suppressed. However, HBD-1 was produced by unburned patient skin tissues transwell-cultured with syngeneic IMC and GL. Similarly, HBD-1 was produced by unburned skin tissues transwell-cultured with allogeneic IMC and GL. These results indicate that GL is inhibitory on the IMC suppressor cell activity in HBD-1 production by unburned patient skin tissues.