Effects of a caspase and a calpain inhibitor on resting energy expenditures in normal and hypermetabolic rats: a pilot study.

Several diseases induce hypermetabolism, which is characterized by increases in resting energy expenditures (REE) and whole body protein loss. Exaggerated protein degradation is thought to be the driving force underlying this response. The effects of caspase and calpain inhibitors on REE in physiological and hypermetabolic conditions, however, are unknown. Thus, we studied whether MDL28170 (calpain inhibitor) or z-VAD-fmk (caspase inhibitor) affect REE under physiological conditions and during hypermetabolism post-burn. Rats were treated five times weekly and observed for 6 weeks. Treatment was started 2 h (early) or 48 h (late) after burn. In normal rats, MDL28170 transiently increased REE to 130 % of normal during week 2-4. z-VAD-fmk reduced REE by 20-25 % throughout the observation period. Within 14 days after burns, REE increased to 130+/-5 %. Whereas MDL28170/early treatment did not affect REE, MDL28170/late transiently increased REE to 180+/-10 % of normal by week 4 post-burn. In contrast, with z-VAD-fmk/early REE remained between 90-110 % of normal post-burn. z-VAD-fmk/late did not affect burn-induced increases in REE. These data suggest that caspase cascades contribute to the development of hypermetabolism and that burn-induced hypermetabolism can be pharmacologically modulated. Our data point towards caspase cascades as possible therapeutic targets to attenuate hypermetabolism after burns, and possibly in other catabolic disease processes.

Elevated endocan levels and its association with clinical severity in Stevens-Johnson Syndrome and toxic epidermal necrolysis.

AIM: The aim of this study was to determine the levels of endocan and other biomarkers of inflammation in the systemic circulation of three groups of patients: 1) biopsy confirmed Stevens Johnson Syndrome, Toxic Epidermal Necrolysis (SJS/TEN) subjects; 2) patients with allergic skin reactions but biopsy negative for SJS/TEN; and 3) normal controls. Besides, this paper aims to investigate the association of endocan levels with the extent of the skin lesions, the presence of purpura, and the degree of acute renal insufficiency, as well as to investigate endocan as a marker of clinical severity by correlating endocan levels with the SCORTEN results (a prognositic score for SJS/TEN). METHODS: Sixteen patients over the age of 18 years who were referred to Loyola University Medical Center with severe allergic skin reactions were recruited over a two-year period from May 2012 to May 2014. A diagnosis of SJS or TEN was confirmed in 7 subjects by skin biopsy. Citrated plasma samples were assayed for endocan, tumor necrosis factor-α (TNFα), vascular endothelial growth factor (VEGF), and C-reactive protein (CRP). The differences between SJS/TEN subjects, biopsy negative subjects, and normal controls (N.=23) were explored using ANOVA and Tukey's post-hoc test. Associations with other clinical variables were identified using linear and logistic regression. RESULTS: Biopsy positive SJS/TEN subjects and biopsy negative subjects had higher endocan levels than normal controls (SJS/TEN: 3.01 ng/mL [IQR: 2.15-8.11]; biopsy negative: 3.96 ng/mL [IQR: 1.54-4.85]; normal controls: 1.79 ng/mL [IQR: 1.67-1.98]; ANOVA P=0.0038). Endocan levels were more strongly associated with SCORTEN in SJS/TEN subjects than in biopsy negative subjects (R2 SJS/TEN=0.5110; biopsy negative=0.0317). SJS/TEN subjects exhibited significantly higher levels of TNF-α compared to normal controls (P=0.0267). The TNF-α levels were significantly lower compared to biopsy negative subjects (P=0.0052). VEGF levels were also elevated among SJS/TEN and biopsy negative subjects compared to normal controls (SJS/TEN: 12.04 pg/mL: [IQR: 7.64-52.7]; biopsy negative: 10.54 pg/mL [IQR: 4.17-6.46]; normal controls: 4.94 pg/mL [IQR: 4.17-6.46]; ANOVA P<0.0001). There was no significant difference in VEGF levels between SJS/TEN and biopsy negative subjects (P=0.7110). Similarly, CRP levels were elevated among SJS/TEN patients and biopsy negative subjects compared to normal controls (SJS/TEN: 32.09 µg/mL [IQR: 31.49-52.08]; biopsy negative: 83.38 µg/mL [IQR: 44.74-145.38]; healthy normal: 1.08 µg/mL [IQR: 0.73-2.03]; ANOVA P<0.0001). There was no significant difference in CRP levels between SJS/TEN and biopsy negative subjects (P=0.2416). CONCLUSION: To our knowledge, this is the first study to evaluate enodcan, a marker of endothelial dysfunction, in the systemic circulation of SJS/TEN patients. Elevated endocan levels were more strongly associated with disease severity among SJS/TEN subjects than among less severe allergic reactions with skin involvement.

Proteasomes in lungs from organ donors and patients with end-stage pulmonary diseases.

Proteasomes appear to be involved in the pathophysiology of various acute and chronic lung diseases. Information on the human lung proteasome in health and disease, however, is sparse. Therefore, we studied whether end-stage pulmonary diseases are associated with alterations in lung 20S/26S proteasome content, activity and 20S subunit composition. Biopsies were obtained from donor lungs (n=7) and explanted lungs from patients undergoing lung transplantation because of end stage chronic obstructive pulmonary disease (COPD; n=7), idiopathic pulmonary fibrosis (IPF, n=7) and pulmonary sarcoidosis (n=5). 20S/26S proteasomes in lung extracts were quantified by ELISA, chymotrypsin-like proteasome peptidase activities measured and 20S proteasome beta subunits analyzed by Western blot. As compared with donor lungs, proteasome content was increased in IPF and sarcoidosis, but not in COPD. The relative distribution of free 20S and 26S proteasomes was similar; 20S proteasome was predominant in all extracts. Proteasome peptidase activities in donor and diseased lungs were indistinguishable. All extracts contained a mixed composition of inducible 20S beta immuno-subunits and their constitutive counterparts; a disease associated distribution could not be identified. A higher content of lung proteasomes in IPF and pulmonary sarcoidosis may contribute to the pathophysiology of human fibrotic lung diseases.

Peripheral blood mononuclear cell-derived erythroid progenitors and erythroblasts are decreased in burn patients.

Patients with large burns suffer from anemia of critical illness. Administration of exogenous erythropoietin is ineffective, and transfusion remains the only effective treatment. We have previously shown that erythroid precursors are decreased 1 week after burn in an animal model. Therefore, we have used a two-phase liquid culture system to quantify peripheral blood mononuclear cell (PBMC) compartment-derived erythroid progenitors (EPs) in burn patients. Institutional review board approval and informed consent were obtained. Blood samples were collected at 1 to 30 days after burn, with a mean TBSA of 37.7 ± 15.8% (n = 10; 90% men; age, 46.0 ± 18 years). Four healthy volunteers served as controls. PBMCs were isolated by Ficoll-Hypaque density-gradient centrifugation and were placed in serum-free expansion medium containing cyclosporine A (1 ng/ml), granulocyte macrophage colony-stimulating factor (20 ng/ml), stem cell factor (30 ng/ml), and interleukin-3 (5 ng/ml; phase I). On day 7, cells were reseeded in serum-free expansion medium containing erythropoietin (1 U/ml), holotransferrin (0.3 mg/ml), and stem cell factor (10 ng/ml; phase II). Aliquots from the phase II culture system on day 6 were incubated with anti-CD71, CD235a, and CD36. EPs (CD71 CD36) and erythroblast subpopulations (colony-forming unit erythroids, Proerythroblasts, and intermediate erythroblasts) were identified based on the expressions of CD71 and CD235a by flow cytometry, calculated per million expanded cells, and expressed as a percentage of controls. Total EPs were significantly decreased by days 28 to 31 after the burn (19%; P < .05). Among the erythroblast subpopulations, colony-forming unit erythroids (11%; P < .004) and proerythroblasts (24%; P < .05), were decreased significantly by days 28 to 31 after the burn. PBMCs of burn patients can be used to study impaired erythropoiesis and anemia of critical illness.

Burn Education Awareness Recognition and Support (BEARS): a community-based juvenile firesetters assessment and treatment program.

In response to the continued staggering statistics of fires set by juveniles and the devastating personal and property costs that are associated with these fires, the Burn and Shock Trauma Institute of Loyola University Medical Center, in collaboration with the State Fire Marshal's Office; the Illinois Fire Safety Alliance; and representatives from the firefighting community, law enforcement, emergency medicine and mental health, came together to create the Burn Education Awareness Recognition and Support Program. Through financial grant support from the International Association of Firefighters, the Illinois Fire Safety Alliance, and other private donations, the Burn Education Awareness Recognition and Support Program is able to provide a free resource to anyone who is concerned about a child playing with fire. Specially trained firefighters assess each child using the tool developed by the Federal Emergency Management Agency. In 2002, we assessed 42 children; 29 of those children were referred through the courts. So far, none of the children treated in our program have returned to fire-setting behaviors.

What are the primary concerns of recently graduated surgeons and how do they differ from those of the residency training years?

HYPOTHESIS: Graduated surgeons have differences in concerns when comparisons are made between fellows and practicing surgeons, practicing surgeons and residents, and male and female surgeons. DESIGN AND SETTING: A survey was distributed to surgeons who graduated from 17 New England residency programs from 1993 to 1996, consisting of 9 demographic questions and 33 items coded on a Likert-type scale (with scores from 1 [least concerning] to 5 [most concerning]). PARTICIPANTS: Surgical fellows and practicing surgeons recently graduated from general surgical residency programs in New England who had participated in a previous study as residents. INTERVENTION: Distribution and completion of the survey. MAIN OUTCOME MEASURE: Personal and career-oriented concerns of recently graduated surgical residents. RESULTS: Personal issues continue to rank high for graduated residents, but the areas of greatest concern became more financially and career oriented. The top concerns of fellows were personal finances (mean score, 3.2), child rearing (mean score, 3.1), salary (mean score, 3.1), postponing family plans (mean score, 3.0), availability of role models (mean score, 2.9), and number of work hours (mean score, 2.8). The top concerns of practicing surgeons were salary (mean score, 3.2), personal finances (mean score, 3.1), number of referrals (mean score, 3.0), support for research (mean score, 2.7), child rearing (mean score, 2.7), and availability of role models (mean score, 2.7). Differences existed between men and women for child rearing, initiating personal relationships, maintaining personal relationships, maternity leave, and promotional advancement. Women were more concerned than men. CONCLUSIONS: Assistance with career planning and job selection during the residency years should be enhanced to diminish the concerns about financial issues and the availability of role models after graduation. Many of the concerns among male and female graduates are still reflective of larger societal expectations, but some, such as promotional advancement, may be attenuated through guidance and mentoring of residents before job selection.

Modulation of macrophage recruitment into wounds by monocyte chemoattractant protein-1.

Previous studies suggest that normal wound repair requires the regulated production of monocyte and macrophage chemoattractants. The current study examines the role of monocyte chemoattractant protein-1 (MCP-1) in coordinating monocyte recruitment into sites of injury. MCP-1 protein was detected in both incisional and excisional murine wounds, with a peak concentration occurring slightly before maximum macrophage infiltration. Compared to wounds treated with control antibody, wounds treated with a neutralizing monoclonal anti-MCP-1 antibody contained significantly fewer macrophages (8.2 +/- 0.9 vs. 14 +/- 1.7 macrophages per high power field, p < 0.05). Conversely, the addition of recombinant MCP-1 to wounds resulted in a substantial increase in the number of macrophages (107% to 124% increase over untreated wounds, p < 0.01). Because macrophages promote wound healing, the effect of recombinant MCP-1 on the wound healing process was examined. Incisional wounds (n = 12) were either left untreated or treated with vehicle alone, 5 ng recombinant MCP-1 in vehicle, or 50 ng recombinant MCP-1 in vehicle. Wound disruption strength was determined on days 7, 14, 21, and 28 for each group. Wounds treated with MCP-1 exhibited a slight increase in wound disruption strength at nearly all time points but this increase did not reach statistical significance. Addition of 100 ng of MCP-1 to excisional wounds did not have any significant effect on wound reepithelialization. Taken together, the results show that MCP-1 is produced within wounds at physiologic concentrations, and is an important positive regulator of macrophage recruitment into sites of injury. Addition of exogenous MCP-1 to wounds of normal mice yields only modest enhancement of the repair process.

A multicenter clinical trial to evaluate the topical hemostatic efficacy of fibrin sealant in burn patients.

Current surgical management of deep partial-thickness and full-thickness burn wounds involves early excision and grafting. Blood loss during these procedures can be profound, thus prompting the use of topical hemostatic agents to control and minimize hemorrhage during grafting. The primary endpoint of this multicenter trial was to evaluate the efficacy of fibrin sealant as a topical hemostatic agent during skin grafting. The secondary endpoint was to obtain data to support the existing safety profile of a human fibrin sealant (FS) in participating patients as indicated by the type, severity, and frequency of any adverse events within the 24-hour postoperative period. A multicenter prospective, open label, Phase III multicenter, randomized, comparative clinical trial evaluated the use of fibrin sealant in burn patients undergoing skin graft procedures. Each patient served as his or her own control in this randomized, unblinded study of the effect on time to hemostasis in donor sites treated with the investigational FS product. At operation, 1 contiguous donor skin harvest site was bisected into 2 equal halves, 1 of which was then randomly selected and treated with fibrin sealant. At the end of the fibrin sealant application, the time to hemostasis in each of the donor site halves was identified by the operating surgeon and recorded by the research coordinator. The use of any other topical hemostatic agents was prohibited. A significant difference (P < .001) was demonstrated in the mean time to hemostasis between the fibrin sealant treated donor sites when compared painwise to the control sites. The significant difference was consistent across the 6 participating study centers. There were no adverse events associated with the use of fibrin sealant. The investigational FS product was shown to be efficacious, because it significantly decreases the time to hemostasis at the donor skin harvest site in patients undergoing skin grafting and was noted not to cause any adverse reactions.

The expression of cyclooxygenase and the production of prostaglandin E2 in neutrophils after burn injury and infection.

Recent studies have demonstrated that neutrophils have the capacity to produce a variety of cytokines after stimulation. The synthesis and release of prostaglandin E2 (PGE2) via the cyclooxygenase (COX) pathway has been reported to occur in activated neutrophils. In the present study, we sought to determine the status of COX protein synthesis and PGE2 production in murine neutrophils after burn injury. The effect of burn injury on neutrophil COX and PGE2 response to infection or lipopolysaccharide (LPS) was also examined. Peritoneal neutrophils were obtained from BDF1 mice at 4, 18, 24, and 36 hours after a 15% TBSA full-thickness scald burn or sham burn. We found that neutrophils from healthy mice express a low level of COX-2 protein. Neutrophil COX-2 protein expression in burn animals was significantly increased at 4 hours and dramatically decreased at 36 hours after burn injury. Animals 36 hours after burn and topically infected with Pseudomonas Aeruginosa had neutrophil COX-2 expression almost identical to burn injury only. Neutrophils harvested from healthy mice cocultured with LPS (1 microg/ml) had a marked induction of COX-2 protein. Neutrophils 24 hours after burn were unresponsive to LPS-stimulated COX-2 enhancement. COX-1 protein was strongly expressed constitutively and not affected further by burn injury or LPS. The production of PGE2 corresponded with the changes in COX-2 expression for all groups of mice. Our data suggested that neutrophils express both COX-1 and COX-2 and produce PGE2. The effects of burn injury on neutrophil COX-2 protein synthesis and PGE2 production suggest that after burn there is a time-dependent response. Insights into not only the global cellular response to injury and infection but also temporal nature of the response are important in the development of the therapeutic treatment strategies for burn patients.

Norepinephrine modulates myelopoiesis after experimental thermal injury with sepsis.

OBJECTIVE: To determine whether thermal injury and sepsis cause an increase in bone marrow norepinephrine release and whether such a release influences bone marrow monocytopoiesis. SUMMARY BACKGROUND DATA: The authors previously demonstrated enhanced bone marrow monocytopoiesis after burn with sepsis. They also showed that physiologic stress and bacterial challenge without injury could lead to a dynamic release of norepinephrine from the bone marrow compartment. In this study, they sought to determine the potential cause-and-effect relationship of bone marrow norepinephrine release on increased monocytopoiesis after burn sepsis. METHODS: Norepinephrine release from bone marrow was determined by traditional pulse-chase methods. Tissue and bone marrow norepinephrine content was ablated by chemical sympathectomy with 6-hydroxydopamine treatment. Clonogenic potential in response to colony-stimulating factors was determined in total nucleated bone marrow cells. Dual color flow cytometry was used to document the distribution pattern of monocyte progenitors. RESULTS: Burn sepsis induced increased norepinephrine release in bone marrow, spleen, and heart. Colony-forming assays demonstrated an increase in responsive colonies, which was significantly attenuated when norepinephrine content was reduced in animals before burn sepsis. Flow cytometric analysis of early and late monocyte progenitors showed a significantly altered distribution profile of monocyte progenitors in norepinephrine-depleted mice compared with norepinephrine-intact mice. Abrogation of bone marrow norepinephrine content resulted in a 62% survival rate in burn septic mice compared with no survivors in norepinephrine-intact mice. CONCLUSIONS: These data suggest that enhanced bone marrow norepinephrine release after burn sepsis may play a role in bone marrow monocytopoiesis, thus contributing to the sustenance of inflammation.

The impact of antithrombin (H) concentrate infusions on pulmonary function in the acute phase of thermal injury.

BACKGROUND: Pulmonary complications occur frequently after thermal injury. OBJECTIVE: This open pilot study was performed as an initial assessment of the safety and efficacy of antithrombin H [AT(H)] concentrate in ameliorating the respiratory morbidity during the acute phase of injury. MATERIALS & METHODS: Thirty-two patients were eligible for the study; of these, nine opted for treatment with q8 h [AT(H)]. The mean daily peak values of pulmonary parameters such as PaO(2)/FiO(2) ratio, and RAW scores were computed for days 1-8. RESULTS: Control and AT(H)-treated patients were similar in age, % total burn surface area, inhalation injury, and mortality. Forty-three percent of the burn controls, and 23% of the AT(H)-treated patients had pneumonia, p<0.01. The median hospital stay for both groups was 42 days; however, the median number of ventilatory days for burn controls was 23 days vs 10 days for AT(H)-treated patients. The AT(H)-treated patients had admission AT plasma levels of 46+/-14% vs 49+/-18% in burn controls, (normal=100+/-20%). The AT plasma level was maintained at 120+/-24% in the AT(H)-treated patients vs 50+/-15% in the burn control group for the first four days following the acute injury, p<0.002. Thrombate(R) concentrate infusions were, in general, well tolerated by patients. The median dose was 97 u/kg/dose q8 h. Compared to burn controls, AT(H)-treated patients had higher PaO(2)/FiO(2) ratios between days 4-6, p<0.01. In comparing these two groups with and without inhalation, airway resistance (assessed by the RAW score) was significantly lower in the AT(H)-treated group with inhalation compared to the burn controls with inhalation on days 2 and 6, p<0.02. CONCLUSIONS: With a trend toward decreased airway resistance during AT(H) concentrate infusions, and increased oxygenation, AT(H)-treated patients had significantly fewer episodes of pneumonia compared to controls. AT(H) concentrates may modify the impact of thrombin on acute inflammation, and improve respiratory function in the acute phase of thermal injury.

Myeloid commitment shifts toward monocytopoiesis after thermal injury and sepsis.

OBJECTIVE: To demonstrate enhanced bone marrow monocytopoiesis in response to thermal injury and sepsis and to provide a mechanism for this observation. SUMMARY BACKGROUND DATA: Although monocyte activation and the resultant dysregulated cytokine production are now the accepted hallmarks of systemic inflammatory response syndrome, no information is available on the status of bone marrow monocyte production under injury conditions; neither has the balance between the two arms of myelopoiesis (monocytopoiesis and granulocytopoiesis) been delineated. METHODS: Peripheral blood absolute neutrophil and monocyte counts were determined 72 hours after the initial injury in sham, burn, and burn sepsis mice. Colony-forming potential in response to colony-stimulating factors (granulocyte, macrophage, and granulocyte/macrophage) was determined in both total nucleated and monocyte progenitor enriched bone marrow cells. Dual color flow cytometry was used to document the distribution pattern of monocyte progenitors. Macrophage colony-stimulating factor receptor density in monocyte progenitors was assessed by 125I macrophage colony-stimulating factor binding assay. RESULTS: Burn sepsis induced circulating monocytosis and granulocytopenia. Colony-forming assays demonstrated an increase in the growth potential of monocyte progenitors and a significant decrease in granulocyte progenitors after burn and burn sepsis. Flow cytometric analysis of early (ER-MP12) and late (ER-MP20) monocyte progenitors showed an increase in monocyte lineage growth in burn sepsis. Radioligand binding assay demonstrated an increase in macrophage colony-stimulating factor receptor expression in monocyte progenitors in burn sepsis. CONCLUSIONS: The data validate the premise that enhanced monocytopoiesis in thermal injury and sepsis results from an imbalance in myelopoiesis that is driven by the increased expression of macrophage colony-stimulating factor receptor.

Bone marrow stem cell and progenitor response to injury.

Hematopoietic stem cells represent a long term reservoir of cells to populate blood with multiple formed cells. These hematopoietic stem cells proliferate and mature into lymphoid, erythroid, and myeloid precursor cells, with the balance of these cell populations modulated by major thermal injury, with or without sepsis. Recent studies indicate that thermal injury shifts this balance to favor the monocyte/macrophage lineage at the expense of neutrophil production. The mechanisms for these changes are now being elucidated with the results of clinical importance, because understanding the dynamics of the different precursor pools could be used to identify patients at greater risk for systemic inflammatory sequelae following major thermal injury.

Role of neutrophils in burn-induced microvascular injury in the intestine.

The present study evaluated burn-induced vascular permeability alterations of rat small intestine in vivo and assessed the effect of neutrophil depletion in burn-injured rats on the altered intestinal microvascular permeability. 125I-labeled bovine serum albumin (125I-BSA) was injected intravenously, and its leakage from circulation into the intestinal tissue was determined by measuring tissue counts of 125I-BSA. Compared with sham, vascular albumin permeability increased 1.7-fold on day 1 post-burn and 3.0-fold on day 3 post-burn in ileum. In the jejunum, albumin permeability increased 1.8- and 2.5-fold on day 1 and day 3 post-burn, respectively. Intestinal tissue edema, determined as increases in tissue water contents, was noted in both intestinal segments on day 1 post-burn; no further increase in edema was found on day 3 post-burn. Neutrophil depletion before burn injury prevented the vascular leakage of albumin and edema in the ileum and jejunum on day 1 post-burn. On day 3 post-burn, the effect of prior neutrophil depletion on vascular permeability was less marked, and edema formation was not affected at all. These findings indicate that an absence of neutrophils prevents the loss of intestinal vascular barrier properties only in the initial periods after burns.

Neutrophil depletion in rats reduces burn-injury induced intestinal bacterial translocation.

OBJECTIVE: To determine whether neutrophil depletion could eradicate intestinal bacterial translocation in bum-injured rats. DESIGN: Prospective, randomized, controlled study. SETTING: University research laboratory. SUBJECTS: Adult male Sprague-Dawley rats. INTERVENTIONS: The rats were intravenously administered a rabbit anti-rat neutrophil antibody causing profound neutropenia and subjected to a 30% total body surface area scald burn. MEASUREMENTS AND MAIN RESULTS: The depletion of neutrophils from the intestine was assessed via measurements of myeloperoxidase (MPO) activity in the intestinal homogenates. In addition, the presence of activated/extravasated neutrophils in intact intestines was determined via immunohistochemical localization of neutrophil nicotinamide adenine dinucleotide phosphate (NADPH) oxidase component protein p47phox. Bacterial translocation was measured using agar cultures and by determining Escherichia coli beta-galactosidase gene via polymerase chain reaction/Southern blot analyses of mesenteric lymph node and spleen, liver, lung, and blood. MPO measurements demonstrated a six-fold increase above the control value in the intestinal tissue in rats on day 1 postburn. The presence of activated neutrophils (expression of p47phox protein) was also markedly increased in the intestines of these rats. The increased MPO activity and p47phox expression accompanied a translocation of indigenous E. coli into the mesenteric lymph node without a spread to other organs. The administration of anti-neutrophil antibody to burn animals prevented an increase in MPO activity and bacterial translocation. CONCLUSION: These studies indicate that enhanced intestinal bacterial translocation caused by burn injury could be related to the increased infiltration of activated neutrophils into the intestinal tissue after bum. The release of neutrophil products such as superoxide anion may effect intestinal tissue damage leading to bacterial translocation of indigenous E. coli.

hsp70, hsp32, and grp78 are increased in thermally injured skin with and without antithrombin(human) concentrate infusion.

An acquired deficiency of antithrombin (AT), an anti-inflammatory protein, develops in patients with thermal injuries. Skin thermotolerance is regulated by heat shock protein (hsp) genes. hsp70, hsp32, hsp27, and glucose-regulated protein78 (grp78) were studied in burned and unburned human skin to determine whether correction of the AT deficiency modulated the intensity of expression of these proteins. Fifty-four human skin samples were prepared by Western blot analysis: 11 unburned and 22 burned control skin samples and 7 unburned and 14 burned skin samples from patients treated with AT(Human), or AT(H). The intensity of hsp32 expression in burned AT(H)-treated skin (P < .001) and in burned control skin (P < .01) was significantly increased compared with unburned control skin. The intensity of expression of hsp70 was statistically significant in burned AT(H)-treated skin compared with unburned control skin (P < .02), as was that of grp78 (P < .01). Thermally injured skin with or without AT(H) treatment had an increased expression of hsp70, hsp32, and grp78 compared with unburned control skin.

How well do third-year medical students learn key objectives in a case-based surgical lecture series?

Faculty members were asked to list major and minor concepts of their case-based session presented during the 12-week 3rd-year surgical clerkship. After each session, students were queried to list the key concepts presented. Data were collected from two groups: one at the end of an academic year and a second at the beginning of the next academic year. Faculty members listed a median of 10 major and 15 minor concepts. The mean number of matched major concepts ranged from 0.2 to 4, and from 0.2 to 3.4 for minor concepts. In a comparative analysis, the end-of-the-year students listed a higher number of matched concepts for 17 of the 20 sessions than the beginning of the year students (8 sessions reached statistical significance, P < 0.05). The current case-based teaching method is not effective in emphasizing key concepts to students. Reformatting cases to better align with key concepts may be one solution to enhance a student's ability to grasp key concepts. Students at the end of the academic year outperformed those at the beginning of the year. This additional variable needs to be considered by faculty and incorporated into their teaching techniques.

Prostaglandin E2 receptor antagonist (SC-19220) treatment restores the balance to bone marrow myelopoiesis after burn sepsis.

BACKGROUND: Although prostaglandin E2 (PGE2) has been shown to be immunosuppressive, its role in the development of specific bone marrow myeloid lineages after thermal injury and sepsis has yet to be elucidated. The purpose of this study was to demonstrate that alterations in bone marrow progenitor proliferation favoring monocytopoiesis in burn sepsis can be restored by blocking the cellular interactions of PGE2. METHODS: A murine model of burn sepsis with and without treatment with SC-19220, a PGE2 receptor antagonist, was used to determine peripheral monocyte and neutrophil counts as well as the colony forming potential of colony-stimulating factor responsive bone marrow progenitors. RESULTS: Burn sepsis augmented the growth of the early colony-forming unit granulocyte-macrophage and monocyte progenitors and the number of circulating monocytes, whereas granulocyte progenitors and circulating neutrophils demonstrated an opposite response. Treatment with SC-19220 nearly reversed these alterations. CONCLUSION: These data indicate that abrogating PGE2's actions during burn sepsis can restore the balance in bone marrow granulocyte and monocyte production, further consolidating the pivotal role PGE2 plays in the pathogenesis of burn sepsis.

Neutrophil depletion prevents intestinal mucosal permeability alterations in burn-injured rats.

Cutaneous thermal injury increases intestinal mucosal permeability. The mechanisms of this functional disturbance are not fully understood. We investigated whether accumulation of neutrophils in the intestine contributes to the increase in mucosal permeability. Labeled and unlabeled lactulose and mannitol were infused into a segment of rat ileum or jejunum. Blood concentrations of [(3)H]lactulose and [(14)C]mannitol were measured after 30, 60, and 90 min. On day 1 postburn, lactulose permeability increased fourfold in the ileum and twofold in the jejunum compared with sham-burned rats; mannitol permeability increased twofold in the ileum and 1. 5-fold in the jejunum. A greater increase in permeability occurred on day 3 postburn in the ileum, but not in the jejunum. The depletion of neutrophils in burned rats prevented the increase in permeability in both segments on day 1 postburn. Histological studies of intestines from burned, with or without neutrophil depletion, and sham-burned rats showed similar morphology. However, numerous neutrophils were found in the extravascular compartment in day 1 postburn, but not in neutrophil-depleted and sham-burned rats. These findings support the concept that the burn-induced increase in mucosal permeability is produced during the accumulation of neutrophils in the intestine and can be abrogated by the depletion of neutrophils.