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Publications (10)19.91 Total impact

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    ABSTRACT: Delayed gastric emptying is common following severe large cutaneous burns; however, the mechanisms of burn-induced delayed gastric emptying remain unknown. The aim of this study was to explore the possible involvement of hyperglycemia and cyclooxygenase-2 receptors in the burn-induced gastric dysrhythmias. Gastric slow waves and gastric emptying were assessed in rats 6 h following sham or burn injury. Animals were randomized to one sham-burn and seven burn groups: untreated; two groups of saline treated (control); insulin treated (5 IU/kg); cyclooxygenase-2 inhibitor treated (10 mg/kg); ghrelin treated (2 nmol/rat); and gastric electrical stimulation treated. It was found that 1) severe burn injury impaired gastric slow waves postprandially and delayed gastric emptying; 2) the impairment in gastric slow waves included a decrease in the slow-wave frequency and in the percentage of normal slow waves, and an increase in the percentage of bradygastria (P = 0.001, 0.01, and 0.01, respectively vs. preburn values). None of the gastric slow-wave parameters was significantly correlated with gastric emptying; 3) cyclooxygenase-2 inhibitor normalized burn-induced delayed gastric emptying (P = 0.3 vs. sham-burn), but not gastric dysrhythmias (P < 0.002 vs. sham), whereas insulin normalized both gastric emptying (P = 0.4 vs. sham-burn) and gastric dysrhythmias (P = 0.3 vs. sham-burn); 4) both gastric electrical stimulation and ghrelin accelerated burn-induced delayed gastric emptying (P = 0.002 and 0.04, respectively, vs. untreated burn). In conclusion, hyperglycemia alters gastric slow-wave activity and delayed gastric emptying, while cyclooxygenase-2 inhibition delays gastric emptying without altering gastric slow-wave activity.
    AJP Regulatory Integrative and Comparative Physiology 07/2010; 299(1):R298-305. · 3.28 Impact Factor
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    ABSTRACT: In the aftermath of a mass disaster, standard care methods for treatment of burn injury will often not be available for all victims. A method of fluid resuscitation for burns that has largely been forgotten by contemporary burn experts is enteral resuscitation. We identified 12 studies with over 700 patients treated with enteral resuscitation, defined as drinking or gastric infusion of salt solutions, from the literature. These studies suggest that enteral resuscitation can be an effective treatment for burn shock under conditions in which the standard IV therapy is unavailable or delayed, such as in mass disasters and combat casualties. Enteral resuscitation of burn shock was effective in patients with moderate (10-40% TBSA) and in some patients with more severe injuries. The data suggests that some hypovolemic burn and trauma patients can be treated exclusively with enteral resuscitation, and others might benefit from enteral resuscitation as an initial alternative and a supplement to IV therapy. A complication of enteral resuscitation was vomiting, which occurred less in children and much less when therapy was initiated within the first postburn hour. Enteral resuscitation is contra-indicated when the patient is in "peripheral circulatory collapse". The optimal enteral solution and regimen has not yet been defined, nor has its efficacy been tested against modern IV resuscitation. The oldest studies used glucose-free solutions of buffered isotonic and hypotonic saline. Studies that are more recent show benefit of adding glucose to electrolyte solutions similar to those used in the treatment of cholera. If IV therapy for mass casualty care is delayed due to logistical constraints, enteral resuscitation should be considered.
    Eplasty 01/2010; 10.
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    ABSTRACT: Gastrointestinal (GI) ileus is a common complication after severe burns. Selective cyclooxygenase-2 inhibitors (COX-2i) improved post-operative ileus, but its effect on burn-induced GI dysmotility is unknown. Our aim was to test whether a COX-2i improves gastric emptying (GE) and small bowel transit (SBT) after burn. Experiment on GE: rats were anesthetized and randomized into sham/scald burn, treated/untreated with COX-2i. Six hours after burn, rats received a phenol red meal and were sacrificed 30 min later. Gastric emptying was determined based on the percentage of phenol red recovered in harvested stomachs. Experiment on SBT: rats received a duodenostomy and were scald/sham burned 5 days later. Six hours after burn, rats received a phenol red meal through the duodenostomy catheter and were sacrificed 100 min later. Geometric center (GC) was calculated for SBT. GE was decreased significantly in burned vs. sham animals (p<0.001). SBT was significantly impaired in burned vs. sham animals (p<0.001). The COX-2i improved GE in the burn rats but not GE in the control rats or SBT in the burn rats. COX-2i improves burn-induced delayed GE, suggesting the mediation of the latter via the prostaglandin pathway.
    Burns: journal of the International Society for Burn Injuries 05/2009; 35(8):1180-4. · 1.95 Impact Factor
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    ABSTRACT: A retrospective analysis of all pediatric patients admitted for acute burn treatment during a 7-year period was conducted to examine patients who underwent femoral artery catheterization and discuss the associated complications and treatment options. The total number of femoral artery catheterizations performed, nature of vascular complications, treatment rendered, and patient outcome were reviewed. Of the 1800 acute burn pediatric patients treated during our study period (1996-2002), 234 patients underwent a total of 745 femoral artery catheterizations. There was a 1.9% incidence of significant complications as a result of catheterization, including problems during catheter insertion, diminished distal arterial pulses following catheter placement and catheter malfunction. Eight patients (3.4%) developed occlusion or spasm of the femoral artery evidenced by loss of distal pulses. Of these, three required thrombectomy and the other five were treated nonsurgically with immediate catheter removal and systemic heparinization. Both groups showed similar overall outcome with return of distal pulses and absence of distal limb or tissue loss. Our findings indicate that femoral artery catheterization in pediatric burn patients is associated with a low occurrence of vascular complications. The majority of patients with acute distal limb ischemic symptoms can be managed nonoperatively with immediate removal of the catheter and systemic heparinization.
    Journal of burn care & research: official publication of the American Burn Association 05/2009; 30(3):432-6. · 1.54 Impact Factor
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    ABSTRACT: Delayed gastrointestinal transit is common in patients with severe burn. Ghrelin is a potent prokinetic peptide. We aimed at testing the effect of ghrelin on burn-induced delayed gastrointestinal transit in rats. Gastric emptying (GE), intestinal transit (IT), and colonic transit (CT) studies were performed in male Sprague-Dawley rats. Rats were randomized into two main groups as follows: sham injury and ghrelin-treated burn injury with doses of 0, 2, 5, and 10 nmol/rat ip 6 h after burn. Sham/burn injury was induced under anesthesia. Rats received a phenol red meal 20 min following ghrelin injection. Based on the most effective ghrelin dose, 1 mg/kg sc atropine was given 30 min before the ghrelin in one group of rats for each study. The rats in each group were killed 30-90 min later; their stomachs, intestines, and colons were harvested immediately, and the amount of phenol red recovered was measured. Percentage of gastric emptying (GE%) and geometric center for IT and CT were calculated. We found 1) severe cutaneous burn injury significantly delayed GE, IT, and CT compared with sham injury (P < 0.05); 2) ghrelin normalized both GE and IT, but not the CT; 3) the most effective dose of ghrelin was 2 nmol/rat; and 4) atropine blocked the prokinetic effects of ghrelin on GE% and IT. In conclusion, ghrelin normalizes burn-induced delayed GE and IT but has no effect on CT in rats. The prokinetic effects of ghrelin are exerted via the cholinergic pathway. Ghrelin may have a therapeutic potential for burn patients with delayed upper gastrointestinal transit.
    AJP Regulatory Integrative and Comparative Physiology 02/2007; 292(1):R253-7. · 3.28 Impact Factor
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    ABSTRACT: A severe burn leads to hypermetabolism and catabolism resulting in compromised function and structure of essential organs. The massive release of cytokines is implicated in this hypermetabolic response. The aim of the present study was to compare cytokine expression profiles from severely burned children without signs of infections or inhalation injury (n = 19) to the cytokine profiles from normal, noninfected, nonburned children (n = 14). The Bio-Plex suspension array system was used to measure the concentration of 17 cytokines. The expression of proinflammatory and anti-inflammatory cytokines was maximal during the first week after thermal injury. Significant increases were measured for 15 mediators during the first week after thermal injury: interleukin (IL) 1beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12 p70, IL-13, IL-17, interferon gamma, monocyte chemoattractant protein 1, macrophage inflammatory protein 1beta, and granulocyte colony-stimulating factor (P < 0.05). Granulocyte-macrophage colony-stimulating factor was significantly increased during the second week after burn (P < 0.05). Within 5 weeks, the serum concentrations of most cytokines decreased, approaching normal levels. When compared with the cytokine levels measured in normal children, a total of 16 cytokines were significantly altered (P < 0.05). After severe burn, a specific cytokine expression profile is observed in patients without complications such as inhalation injury or sepsis. The cytokine concentrations decrease during 5 weeks after burn but remain elevated over nonburned values. Furthermore, the elevation in most serum cytokine levels during the first week after burn may indicate a potential window of opportunity for therapeutic intervention.
    Shock 07/2006; 26(1):13-9. · 2.61 Impact Factor
  • Journal of Burn Care & Research - J BURN CARE RES. 01/2006; 27.
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    ABSTRACT: Enteral resuscitation could provide a means to resuscitate burn shock when intravenous (IV) therapy is unavailable, such as in mass disasters. We evaluated the extent of intestinal absorption and resuscitative effects of World Health Organization Oral Rehydration Solution after a 40% TBSA burn in anesthetized swine compared with the IV infusion of lactated Ringer's infused by Parkland formula. Plasma volume (PV) was measured using indocyanine green dye dilution. Intestinal absorption was assessed using phenol red as a nonabsorbable marker. Changes in hematocrit, hemodynamics, and measured PV showed equivalent resuscitative effects of enteral and IV resuscitation. The duodenal fluid absorption rate started at 77 +/- 32 ml/hr per meter of intestine during the first hour and increased to 296 +/- 40 ml/hr during the fourth hour of resuscitation, with a total of 93 +/- 2% of World Health Organization Oral Rehydration Solution infused into the intestine being absorbed. Intestinal absorption rates after burn injury are sufficient to resuscitate a 40% TBSA burn.
    Journal of burn care & research: official publication of the American Burn Association 01/2006; 27(6):819-25. · 1.54 Impact Factor
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    H SALLAM, H OLIVEIRA, JDZ CHEN
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    ABSTRACT: Introduction: Severe burn injury is known to delay gastric emptying in both animals and humans; however no data are available on its effect on gastric myoelectrical activity (GMA). We aimed at studying the effect of burn injury on GMA as it might contribute to burn-induced delayed gastric emptying. Methods: Surgical implantation of a pair of cardiac pacemaker wires onto the stomach serosa was carried out in 20 adult male Sprague-Dawley rats. Following recovery, GMA was recorded for 30 min in both fasting and fed conditions. The following day, rats received a sham or a 3rd degree scald burn injury under anesthesia. Proper fluid resuscitation and analgesia were given to all animals. Six hours after sham/burn injury, GMA was recorded for 30 min again in both fasting and fed conditions. A methylcellulose meal was mixed with phenol red (marker), so that the percentage of gastric emptying could be calculated based on the amount of phenol red recovered from the stomach. GMA parameters were computed using previously validated spectral analysis software developed in our laboratory, including dominant frequency/power and percentages of normal slow waves, bradygastria, tachygastria and arrhythmia. The normal slow wave frequency range was 4–6 cycles per min (cpm) in rats, while ≤4 cpm and ≥6 cpm were considered bradygastria and tachygastria respectively. Arrhythmia was established if the slow wave frequency had no specific range. Results: 1) None of GMA parameters showed any statistical differences in the fasting condition after burn (p > 0.05). 2) Significant changes in GMA with burn were only observed postprandially, including: a decrease in dominant frequency (4.5 ± 0.2 vs. 5.1 ± 0.2, p = 0.002) and in the percentage of normal slow waves (67.2 ± 7.3 vs. 84.5 ± 4.1, p = 0.02) and an increase in the percentage of bradygastria (24.7 ± 6.8 vs. 9 ± 3.9, p = 0.02). 3) The percentage of gastric emptying was decreased after burn to 40.3 ± 6.5 vs. 77 ± 3.2 in previously obtained controls (p = 0.0003); however, it did not correlate significantly to any of GMA parameters before or after burn, whether in fasting or in fed conditions (p > 0.05). Conclusion: Severe burn injury impairs both GMA and gastric emptying in rats. However, these alterations are not correlated with each other, suggesting that gastric dysrhythmia is a manifestation of burn rather than the cause of burn-induced delayed gastric emptying.
    Neurogastroenterology and Motility 01/2006; 18(6):489-489. · 2.94 Impact Factor
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    ABSTRACT: The hypercatabolism after massive pediatric burns has been effectively treated with recombinant human growth hormone, an anabolic agent that stimulates protein synthesis and abrogates growth arrest. While experimental studies have shown increased potential for fibrosis induced by growth hormone therapy, adverse effects on human scars have not been investigated. Our aim was to evaluate hypertrophic scar formation in 62 patients randomized to receive injections of 0.05 mg/kg/day of recombinant human growth hormone or placebo, from discharge until 1 year after burn. Scar scales were used to evaluate scar-severity at discharge, 6, 9, 12, and 18-24 months after burn, by three observers blinded to treatment. Computer-assisted planimetry allowed quantification of percentage of hypertrophic scar formation. Types I and III collagens were localized and quantified in scars and normal skin of patients from both groups, using immunohistochemistry with confocal laser microscopy analysis. Insulin-like growth factor-1 blood levels helped assess compliance. Statistical analysis showed that scar hypertrophy significantly increased from 6 to 12 months after injury in both groups, while decreasing at 18-24 months postburn. Types I and III collagens were statistically increased in the reticular layer of scars from both groups when compared to paired normal skin. Insulin-like growth factor-1 was significantly increased in the recombinant human growth factor-treated group. No differences were seen when recombinant human growth factor and control groups were compared using the scar scales, planimetry, or immunohistochemistry. We concluded that recombinant human growth hormone therapy did not adversely affect scar formation and should not contraindicate the administration of recombinant human growth hormone as a therapeutic approach to severely burned children.
    Wound Repair and Regeneration 01/2004; 12(4):404-11. · 2.76 Impact Factor