摘要:

BackgroundInfection and multiple organ failure remain the principal causes of late mortality after trauma despite advances in the resuscitation of injured patients. Because a better understanding of postinjury leukocyte trafficking is essential to the development of possible therapeutic measures aimed at preventing these complications, we have performed a study of one factor in the early posttrauma endothelial adhesion behavior of monocytes, lymphocytes, and neutrophils: their cell surface expression of L-selectin (CD62L). We have also studied the plasma levels of soluble L-selectin in these patients.Methodsor=to 16), 17 with moderate (ISS = 9-15), and 8 with minor (ISS < 9) trauma. Cell surface L-selectin was measured on leukocyte subsets by staining with specific fluorescent-labeled monoclonal antibodies to CD62L and using flow cytometry. Both the percentage of cells expressing the molecule and the mean channel fluorescence were measured. Levels of soluble L-selectin were measured in the plasma, sampled concurrently, by enzyme-linked immunosorbent assay.ResultsMonocytes, lymphocytes, and neutrophils all showed an early increase in cell surface L-selectin expression as measured by mean channel fluorescence (p < 0.0001, p < 0.001, and p < 0.0001, respectively), and this persisted in later samples taken at a median 20 hours after injury (p < 0.0001, p < 0.0001, and p < 0.01). Only monocytes showed an increased percentage of cells expressing the molecule in the early phase (p < 0.02), and this remained in the later phase (p < 0.001). Monocytes also showed a further significant increase in mean channel fluorescence (p < 0.02) between the two periods. No significant changes in levels of plasma soluble L-selectin were found at either stage.ConclusionAn increase in the expression of L-selectin on each of three leukocyte populations has been demonstrated in the early phase after trauma. This would tend to promote rolling behavior of leukocytes and increase their contact with the vascular endothelium. There were marked differences in the later responses of the three populations, which may represent differential control of their behavior.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Hypertonic saline (HS) reduces hemorrhage-induced lung injury by suppressing the neutrophil oxidative burst and reducing lung neutrophil influx. This study investigated whether this is caused by the effects of HS on endothelial adhesion molecule expression, the production of chemoattractants in the lung, or a direct effect of HS on neutrophil selectin expression.MethodsBALB/c mice were made to hemorrhage to 40 mm Hg for 1 hour and resuscitated with shed blood and either 4 mL/kg 7.5% HS or two times the shed blood volume of lactated Ringer's solution (LRS). Neutrophil L selectin expression was determined by flow cytometry, total neutrophil counts were obtained by differential staining, and pulmonary endothelial P and E selectin expression was evaluated by immunohistochemistry. Chemoattractants in lung lavages were determined with a modified Boyden chamber migration assay.ResultsChemotactic activity of lavage fluid of HS-treated animals was not significantly different from that of LRS-treated animals, and endothelial P and E selectin expression was not altered by HS resuscitation. Neutrophils of HS-treated animals, however, expressed significantly less L selectin than those of LRS-treated mice. Concomitantly, circulating neutrophil counts of LRS-treated animals were significantly decreased compared with those of HS-treated mice.ConclusionHS had little effect on endothelial selectin expression and chemoattractant production in the lung. HS significantly decreased neutrophil L selectin expression, however. This suggests that HS resuscitation may reduce lung injury by preventing neutrophil L selectin expression and endothelial adhesion.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundT-cell response to trauma has been assessed primarily by sampling peripheral blood lymphocytes. We hypothesized that lymphocytes residing in tissue and traveling through lymph vessels are more likely to be activated by tissue injury and hemorrhage-induced hypoperfusion. We compared peripheral blood T-cell response with tissue or lymph T-cell response in an ovine model of multiple injury.MethodsAnesthetized adult sheep instrumented with a chronic prefemoral lymph fistula were subjected to lower-extremity fractures, fixed-volume hemorrhage, resuscitation, and fracture stabilization. Peripheral blood and tissue T-cell receptor expression was determined at baseline and after injury.ResultsAt baseline, we found significant differences in the expression of CD4, CD8, and L selectin between peripheral blood T cells and tissue T cells. After trauma, the percentage of tissue T cells expressing CD8 decreased from 19 +/- 9 to 14 +/- 5 (p < 0.05) and the percentage expressing gamma delta-TcR receptors decreased from 12 +/- 4 to 7 +/- 2 (p < 0.05). T-cell phenotype composition in peripheral blood was not affected by trauma.ConclusionPeripheral blood T-cell composition differs from tissue T-cell composition before and after trauma. Trauma produced changes in tissue T-cell phenotypes but not in peripheral blood T-cell phenotypes.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundProstaglandin E2(PGE2) is a major contributor to the production and maintenance of immunosuppression after overwhelming injury, leading to increased infectious morbidity and mortality in trauma patients. Elucidation of the cellular pathways involved in PGE2production could lead to potential therapeutic interventions. The purpose of this study was to determine the role of cyclooxygenase II (COX-2) in PGE2production by MO and to investigate the cellular mechanism of COX-2 gene activation.MethodsMouse macrophages (MO), RAW 264.7, were exposed to Escherichia coli lipopolysaccharide (LPS) in the presence of cyclooxygenase inhibitors (ibuprofen or NS398). COX-1 and COX-2 mRNA expression and PGE2production were measured by Northern blot assay and enzyme-linked immunosorbent assay, respectively. Nuclear factor kappa B (NF kappa B) activity was measured by electrophoretic mobility shift assay. To elucidate the role of NF kappa B in LPS-induced COX-2 gene activation, MO were exposed to LPS in the presence of an NF kappa B inhibitor, TPCK.ResultsLPS increased MO COX-2 mRNA expression but had no effect on COX-1 mRNA expression. Both ibuprofen and NS398 inhibited COX-2 mRNA as well as PGE2production by LPS-stimulated MO. In addition, LPS-induced NF kappa B activity was attenuated by these agents. Inhibition of NF kappa B with TPCK reduced COX-2 but not COX-1 gene expression and decreased PGE2production by LPS-stimulated MO.ConclusionOur data indicate that COX-2 gene expression by LPS-stimulated MO is dependent on NF kappa B. Cyclooxygenase inhibitors reduced PGE2production by inhibiting both COX-2 mRNA expression and preventing NF kappa B activation.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundFull-thickness (FT) and cultured keratinocyte (CK) allografts have been used as temporary skin replacements in patients with massive burns, but these grafts are ultimately rejected after restoration of host immunocompetence. Genetic engineering has permitted the creation of knockout (KO) mice deficient in class I or class II major histocompatibility antigens. This study examines the immunogenicity of such grafts to determine if these genetically modified keratinocytes could be used for permanent wound coverage.MethodsHost sensitization to alloantigen was assessed by second-set rejection. CBA mice (n = 111) were primed with flank grafts consisting of FT and CK allografts from normal C57BL/6 donors, FT and CK class I KO allografts, FT and CK class II KO allografts, and CK autografts. Three weeks later, hosts were challenged with normal tail allografts and observed for second-set rejection. Median graft survival was analyzed by chi squared and Wilcoxon rank tests. In the second experiment, cytotoxic T lymphocytes (CTLs) were harvested from CBA mice (n = 28) 3 weeks after flank grafting. CTL effectors were tested on radiolabeled targets at various ratios in a51Cr release assay. Dilution curves of CTL activity were compared by analysis of variance.ResultsHosts primed with CK or FT allografts demonstrated accelerated rejection of second-set tail grafts compared with hosts covered with CBA autografts. CK knockout grafts were less immunogenic than FT knockout skin; class II KO allografts were considerably less immunogenic than class I KO allografts. CTL activity against the knockout CK allografts was negligible compared with that of hosts primed with normal allografts or FT knockout allografts.ConclusionAlthough full-thickness knockout skin retains substantial immunogenicity, cultured keratinocytes deficient in class II antigens fail to prime for accelerated second-set rejection and do not elicit a CTL response in the graft recipient. This lack of immunogenicity may permit the indefinite survival of allogeneic knockout keratinocytes in patients requiring massive wound excision and coverage.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

ObjectivesTo describe our experience with the use of limited peak inspiratory pressure (PIP), volume-controlled ventilation, and permissive hypercapnia in patients with severe pulmonary blast injury.MethodsPatients with pulmonary blast injury were ventilated using volume-controlled, synchronized intermittent mandatory ventilation. Whenever PIP exceeded 40 cm H2O, the tidal volume was decreased to maintain PIP at less than 40 cm H2O. Whenever the arterial pH fell below 7.2, the ventilator rate was increased in increments of 2 breaths per minute until the arterial pH rose to 7.25.ResultsBetween 1994 and 1996, 17 patients with severe pulmonary blast injury (10 from enclosed space explosions and seven from open space ones), requiring mechanical ventilatory support were admitted to our intensive care unit. Four patients developed increasing PaCO2levels (to 93 +/- 12 mm Hg) associated with the reduction in arterial pH that was corrected by increasing the ventilator rate. There was evidence of ventilator-induced pulmonary barotrauma. Of the 17 patients, 15 patients (88%) survived.ConclusionsLimited PIP in a volume-controlled ventilation is a useful and safe mode of mechanical ventilation in patients with pulmonary blast injury.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundThe literature on early management of gunshot wounds (GSWs) to the face is scant, with only six series reported in the English-language literature in the last 12 years. In the current study, we present a large series from a busy trauma center in an effort to identify early diagnostic and therapeutic problems and recommend management guidelines.MethodsRetrospective analysis was done for all GSWs of the face during a 4-year period. Data were obtained from the Trauma Registry and Trauma Patient Summary hard copies.ResultsDuring the study period, there were 4,139 admissions for GSWs, with 247 (6%) involving the face. An associated brain trauma was found in 42 patients (17.0%), and cervical spine fracture was found in 20 patients (8.1%) with GSWs to the face. In 43 patients (17.4%), there was a need for emergency airway control because of local hematoma or edema. Angiography was performed in 70 patients (28.3%) for evaluation of a large hematoma or continuous bleeding, and in 10 of these patients successful embolization of bleeders was achieved. No patient required operative control of bleeding from facial structures. Overall, only 96 patients (38.9%) underwent operation for soft-tissue repair or reduction of facial bone fractures. There were 36 deaths (14.5%) from severe brain injury or severe bleeding from associated chest or abdominal injuries. No death occurred in isolated GSWs to the face.ConclusionMost civilian GSWs can safely be managed nonoperatively. Airway control is required in a significant number of patients and should be established very early. Bleeding from the face is best controlled angiographically. The brain and cervical spine should be aggressively assessed radiologically because of the high incidence of associated trauma.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundNational guidelines recommend that patients with Glasgow Coma Scale (GCS) scores of less than 14 be triaged to trauma centers. We hypothesized that the motor component of the GCS (GCSM) would be equally sensitive as the total GCS in head injury triage.MethodsA 2-year retrospective review of 3,235 injured adults transported directly to a Level I trauma center.Results3.ConclusionGCSM is equivalent to GCS for prehospital triage, and in view of its simplicity it should replace the GCS in triage schemes.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

BackgroundIn the assessment of blunt abdominal trauma, the reliability of ultrasonography (US) in identifying individual organ injuries remains uncertain, in spite of its usefulness in detecting hemoperitoneum. This study was designed to evaluate the overall diagnostic value of US, including identification of individual organ injuries.MethodsThe accuracy of US in the detection of intra-abdominal injuries and the identification of individual organ injuries was evaluated in 1,239 patients seen during a 15-year period. Accuracy was based on detection of intraperitoneal fluid, free air, or irregular parenchymal lesions.ResultsFor the detection of injuries, US was 94.6% sensitive, 95.1% specific, and 94.9% accurate. Individual organ injuries were identified with sensitivities of 92.4, 90.0, 92.2, 71.4, and 34.7% for the liver, spleen, kidneys, pancreas, and intestine, respectively.ConclusionUS is reliable for the detection of injuries and the identification of solid-organ injuries despite its poor sensitivity for intestinal injuries.

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0022-5282    

出版商:OVID    

年代:1998

数据来源: OVID