ISSN:0273-8481    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

We studied the effect of the oral administration of a water-soluble antioxidant solution containing ascorbic acid, glutathione, and a precursor for glutathione synthesis, N-Acetyl-Lcysteine, on liver antioxidant activity, liver cell energetics, and mortality' in rats in response to a 20% third-degree burn injury challenged 5 days later with an intraperitoneal injection of 30 mg/kg endotoxin. Rats with burns were fluid-resuscitated with subcutaneous Ringer's lactate solution according to the Parkland formula (4 cc/kg/%burn). Rats challenged with endotoxin 5 days after burn were given an additional 100 ml/kg of subcutaneous Ringer's lactate solution immediately after the injection of endotoxin. A group of rats with burns challenged with endotoxin 5 days after burn were given an oral antioxidant solution beginning after burn injury. Liver cell energetics were measured as tissue energy charge potential (ECP), adenosine triphosphate (ATP) content, and total adenine nucleotides. The levels of endogenous liver glutathione, catalase, vitamin C, and vitamin £ were measured to monitor antioxidant status. We found that burn injury alone did not produce any mortality over the 6-day period despite a 35% decrease in liver energy charge potential resulting from a decrease in ATP, a 34% decrease in liver catalase activity, and a 20% decrease in liver vitamin C. It was interesting that glutathione increased and vitamin E remained unchanged. We found that endotoxin injury combined with burn injury produced a 61% mortality rate with a 63% decrease in liver energy charge potential, again resulting from a decrease in ATP, a 74% decrease in liver catalase activity, a 16% decrease in vitamin C, and a 29% decrease in vitamin E. Glutathione was significantly decreased compared with burn alone. We compared the liver antioxidant status of survivors with that of nonsurvivors who were killed when appearing moribund and found that glutathione was decreased by 51% and vitamin C by 73% in nonsurvivors over that in survivors, whereas catalase and vitamin E levels were comparable between the two groups. The oral administration of the antioxidants prevented mortality and the decrease in antioxidant activity and attenuated the decrease in energy charge potential.We conclude that a 20% burn produces a modest decrease in liver energy charge potential and antioxidant defenses without producing mortality. The addition of endotoxin further decreases liver antioxidant defenses, liver energy charge potential, and markedly increases mortality. Antioxidants, given post-burn, restored antioxidant defenses, attenuated the altered cell energetics, and prevented mortality, indicating oxidants to be the cause of mortality. This data also suggests that a critical value of decreases in antioxidant defenses and ATP exists, resulting in mortality.

ISSN:0273-8481    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

In vivo longitudinal (T1) and transverse (T2) relaxation times of hepatic intracellular and extracellular sodium were studied in rats with sham burn or burn injury with 23NaNMR spectroscopy and shift reagent. Burn injury decreases hepatic extracellular sodium content by 17% compared with sham burn, whereas it increases the percent of the fast T2component of extracellular sodium, suggesting an increase in the fraction of bound Na±sites in the extracellular space. It is interesting that the relaxation characteristics of intracellular sodium remained unchanged despite a 57% increase in intracellular sodium content, suggesting the increase in intracellular free sodium is matched by either a proportional increase in intracellular bound sodium or an uncovering of ordered domain sites that can preferentially orient rapidly exchanging sodium ions. This study also demonstrated that spin lattice (T1) relaxation rates or the percent contribution of the fast/slow T2components of the combined intracellular/extracellular23Na signal (before the infusion of shift reagent) may also be sensitive to changes in intracellular sodium levels during pathologic changes.

ISSN:0273-8481    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Pressure-controlled ventilation is used to treat smoke inhalation injury to achieve adequate oxygenation and ventilation at lower peak inspiratory pressures. A portable pressure controlled time-cycled transport ventilator permits this modality to be used in the field. We have examined the safety and efficacy of this ventilator for aeromedical transfer of thermally injured patients. Burn flight teams transported 146 intubated patients with thermal injury to the U.S. Army Burn Center widi this system. The average extent of burn injury was 40.45% total body surface area with an average full-thickness injury of 25.29% total body surface area. The transport ventilator was used for 57 rotary wing and 89 fixed wing missions. The study group was transported a total of 86,889 miles without in-flight morbidity, mortality, or failure of ventilation. Arterial blood gas analysis at conclusion of flight demonstrated an arterial pH ≥7.35 in 85% of the patients, an arterial partial pressure of carbon dioxide ≤45 torr in 97%, and an arterial partial pressure of oxygen ≥70 torr in 99%. Pressure-controlled ventilation performed by an experienced transport team with this ventilator is safe and effective for the long-range aeromedical transfer of intubated patients with burns.

ISSN:0273-8481    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

This study systematically examined the effect of varying continuous-wave carbon dioxide laser scanning parameters on the resultant tissue effects. The effects of varying scanning speed, laser power, and laser beam diameter were assessed. Residual thermal damage at the center of the crater was approximately 120 µm independent of dwell time and laser irradiance. However, thermal damage zones along the sides of the ablation crater increased as laser dwell times exceeded 50 msec. This study demonstrates that under appropriate conditions a scanned continuous-wave carbon dioxide laser can ablate tissue with a zone of residual thermal injury less than 200 (µm, making it useful for cutaneous surgery and the debridement of burn wounds before skin grafting is performed.

ISSN:0273-8481    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Extended trauma causes a failure of T-lymphocyte function due to suppressed interleukin-2 synthesis; however, the role of IL-2 receptor, especially its soluble form (sIL-2R), needs to be further evaluated. It was the objective of the study to assess the kinetics of sIL-2R within different settings of trauma and to define its clinical value and possible predictive role. Three groups of patients with trauma were included in the study. Groups 1 and 2 consisted of multiply injured patients (injury severity score 35 ± 4 and 32 ± 4, respectively); burned patients formed group 3 (injury severity score 38 ± 9). Serum samples were collected at the site of the accident (group 1) and during the posttrauma course in the hospital (group 2, daily; group 3, weekly) and sIL-2R was measured in these samples. sIL-2R was within the normal range in groups 1 and 2, but was significantly increased in group 3. There was no correlation between serum concentrations of this mediator and susceptibility to infectious complications or outcome.

ISSN:0273-8481    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

The clinical take rates of cultured keratinocyte autografts are poor on a full-thickness wound unless a dermal bed is provided. Even under these circumstances two important problems are the time delay in growing autografts and die fragility of the grafts. A laser-perforated hyaluronic acid membrane delivery system allows grafting at early confluence without requiring dispase digestion to release grafts from their culture dishes. We designed this study to investigate the influence of this membrane on clinical take rates in an established porcine kerato-dermal grafting model. The study demonstrated a significant reduction in take as a result of halving die keratinocyte seeding density onto the membrane. The take rates, however, of grafts grown on the membrane at half or full conventional seeding density and transplanted to a dermal wound bed were comparable, if not better, than those of keratinocyte sheet grafts.

ISSN:0273-8481    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

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 die 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 ≥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, bodi 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 ≥10 days.

ISSN:0273-8481    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Donor allograft skin preserved in 85% glycerol is used as a temporary coverage for large burn wounds. Glycerol treatment does not affect the structural integrity of the skin; cells are well preserved but dead. However, cells expressing major histocompatibility class II molecules can still be observed. In this study we investigated the mechanism underlying the clinical observation that glycerol-treated alloskin will be destroyed but after a prolonged period. We compared the in vitro immunogenicity of untreated and 85% glycerol-treated human skin cells. Human purified blood T cells did not proliferate when cultured with allogeneic treated skin cells, whereas untreated cells induced a distinct response. A moderate response was measured after adding T cells and viable antigen presenting cells, such as monocytes, to the allogeneic treated skin cells. However, the response on untreated skin cells was much higher. These results favor the suggestion that after transplantation of glycerol preserved skin is performed, an inflammatory process mediated by infiltrating host monocytes occurs rather than a rejection process mediated by T cells.

ISSN:0273-8481    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Facial mutilation after an assault with chemicals is rarely discussed in the literature even though it is a devastating injury that occurs worldwide and is not prohibited or punished by special laws. It is our purpose to describe the devastating outcome of facial mutilation after an assault with chemicals and to draw attention to this injury as a worldwide problem. We studied fifteen patients who sustained facial mutilation with chemicals. The common story was that the patient's spouse was the perpetrator, that sulfuric acid was used, and that the deed occurred after marital or financial discord. All victims were disfigured severely and most became reclusive and rarely left their homes. Six patients (40%) had total bilateral blindness and one suffered partial loss of vision. Lower eyelid ectropion (14), microstomia (12), cervical flexion contracture (10), ear deformity (8), and nostril stenosis (6) were common. Few of the perpetrators were prosecuted. We reviewed the literature and found that the problem has been described all over the world, and that the outcome is similar to that which we described. The problem deserves worldwide recognition and attention.

ISSN:0273-8481    

出版商:OVID    

年代:1997

数据来源: OVID