摘要:

Interferon-gamma (IFN-γ) has been demonstrated to improve outcome following localized infection and hemorrhagic shock in experimental studies. We sought to determine the effects of IFN-γ in a clinically relevant murine model of intra-abdominal polymicrobial sepsis. Fifty male BDF1mice, each weighing 23–28 g, underwent cecal ligation and puncture (CLP) followed by administration of subcutaneous injections of IFN-γ 100–22,500 U or vehicle control immediately post-CLP and then daily. In a second set of experiments, 60 mice underwent daily injections of vehicle control or 100 U IFN-γ 24, 48, or 72 hours prior to CLP. Interferon-gamma administered following CLP led to increased mortality and earlier deaths in a dose-dependent fashion (p< 0.05). Interferon-gamma given 24, 48, or 72 hours prior to CLP resulted in no demonstrable benefit when compared with animals that did not receive IFN-γ (p= 0.14,p= 0.94, andp= 0.97, respectively). While IFN-γ has been reported to be of value in selected clinical situations by improving resistance to infection, it may not be capable of conferring protection following surgery or trauma with intra-abdominal sepsis, and in fact may be detrimental.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

BackgroundBecause of in vivo limitations, the mechanisms underlying the process of bacterial translocation are poorly understood. Thus, an in vitro model system to study the translocation process was developed.MethodsTransformed human colonic carcinoma (Caco-2) intestinal cells were grown as a polarized monolayer on semi-permeable membranes contained in the upper compartment of a two-compartment system. Once the Caco-2 monolayer had reached confluence, the ability of six different species of bacteria to translocate across the monolayer was tested using a dose-response curve of bacteria (102, 104, or 105) organisms.ResultsAt inocula of 104or 105but not 102organisms, bacteria crossed the monolayer. Bacterial passage across the monolayer was bacterial species specific, with gram-negative enterics being the best, gram-positive aerobes being intermediate translocators, and strict anaerobes being the poorest translocators.ConclusionThe results of this study indicate that bacteria translocate across the Caco-2 monolayer in a dose-dependent and species-related fashion and support the use of this in vitro epithelial cell culture system as a model for studying bacterial transport.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Smoke inhalation (SI) affects the homogeneity of lung perfusion possibly by increasing alveolar surface tension. Anesthetized dogs (n = 8) were ventilated with a tracheal divider and a dual ventilator. One lung (left or right) was exposed to 5 minutes of SI while the other remained on room air. Total pulmonary blood flow (cardiac output) was measured by thermal dilution and left lung blood flow was measured with an ultrasonic flow probe. Since SI is associated with elevation of alveolar surface tension (AST), we studied a second group of dogs (n = 6) in which AST was increased in one lung with aerosolized dioctyl sodium sulfosuccinate (OT). The OT elevates AST without otherwise damaging the lung. Unilateral SI resulted in systemic hypoxemia (Pao2fell from 91 ± 6 to 55 ± 4 mm Hg) and increased venous admixture (9 ± 2% to 29 ± 4%) both of which remained different from baseline values (p< 0.05) for 2 hours. Blood flow to the smoke exposed lung increased gradually and became significantly larger than that to the contralateral normal lung 2 hours following inhalation (smoke lung = 64% ± 6% and normal lung = 36% ± 6% of total blood flow). Following smoke exposure, pulmonary vascular resistance (PVR) increased with time in the unexposed normal lung (baseline = 8.7 ± 1.4; 2 hours post smoke = 22.6 ± 7.9 mm Hg/L/min,p< 0.05); PVR did not change in the smoke injured lung. Unilateral OT inhalation increased AST and caused atelectasis and hypoxemia (Pao2fell from 89 ± 14 to 65 ± 6 mm Hg), but did not change blood flow distribution significantly. Both smoke and OT increased lung water as evidenced by an increase in lung wet weight to dry weight ratio (W/D) (5.8 ± 0.3 and 7.5 ± 0.8, respectively,p< 0.05) compared with the normal contralateral lung (4.9 ± 0.2 W/D). Increased AST (OT aerosol) did not alter blood flow to either lung suggesting that blood flow redistribution following smoke inhalation was not caused by alterations in surface tension. We speculate that smoke inhalation impairs vascular reactivity and promotes release of vasoactive substances. These substances cause constriction of vessels in the normal but not the smoke damaged lung.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Plasma levels of interleukin 1β (IL-1β), tumor necrosis factor alpha (TNFα), interleukin 6 (IL-6), and markers of protein metabolism were determined in 12 burn patients throughout the healing period (day 2 to 21 post-injury) to determine the pattern of variations in plasma cytokine concentration. To establish the relationship between cytokine production and the nutritional status a wide range of severity standpoints (burn surface area ranging from 9% to 82%) was chosen. Interleukin 6 levels were increased in all patients throughout the study period; maximum concentrations (615 ± 198 pg/mL) were reached on day 4 and correlated (p< 0.01) with the extent of burn injury. Tumor necrosis factor alpha levels were also elevated; they were significantly higher on day 7 in the patients who developed sepsis than in the other patients (67 ± 21 pg/mL vs. 20 ± 7 pg/mL;p< 0.05) but did not correlate with the extent of burn injury. Interleukin 1β was rarely detected. Cortisolemia on day 7 was inversely correlated with levels of TNFα but not with those of IL-6. Interleukin 6 levels correlated positively with protein turnover (phenylalaninemia) and catabolism (3-methylhistidine/creatinine ratio) and negatively with levels of fibronectin and transthyretin. Our data indicate that the systemic cytokine response to burn injury is mainly represented by IL-6. These data also support the hypothesis that IL-6 is a key mediator of the variations in protein metabolism following burn injury.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Two catalytically active proteases, dipeptidyl peptidase IV (DP IV) and aminopeptidase (AP), not previously reported as present in burn wound exudates, have been identified by substrate specificity and susceptibility to known enzyme inhibitors. The ratio of the two enzymes in exudates is significantly different from the ratio in plasma collected from the same patient during the same time interval, suggesting that measurement of exudate components may be more significant than plasma activities in evaluating local conditions in the wound. A number of biologically significant substances are DP IV substrates, and the list can be considerably extended by the sequential action of AP and DP IV. Some polypeptides are converted to their biologically active form by DP IV action, while others are degraded to inactive forms. Either action generates X-Pro dipeptides, which have a demonstrably beneficial effect on wound healing. Although not resolved by molecular sizing or anion exchange chromatography, DP IV and AP in a burn wound exudate were purified by affinity chromatography.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Ambient temperature-induced hypothermia noted in trauma patients is frequently accompanied by a bleeding diathesis despite “laboratory normal” coagulation values. To document this impression, the following experiment was conducted. Coagulation studies and platelet function studies were performed in ten minipigs during induced whole body hypothermia (40°C to 34°C) and rewarming. Cooling was achieved in 2 to 3 hours and rewarming took 4 to 5 hours. In addition, similar coagulation and platelet function studies were conducted on plasma samples from the same animals that were cooled and then rewarmed in a water bath. Platelet counts and function as measured by Sonoclot analysis and aggregation did not decrease significantly with hypothermia in either model. Plasma cooled in a water bath demonstrated abnormal PT and aPTT (p< 0.001). Whole body hypothermia demonstrated abnormal bleeding time and PT (p< 0.001). Ambient temperature-induced hypothermia produced significant coagulation defects in a porcine model. Some of the coagulation defects were most pronounced during rewarming.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Although numerous studies have reported the use of intraoperative blood salvage in elective spine, cardiac, and vascular surgery, very few have assessed its efficiency during emergency surgery after spine trauma. We therefore retrospectively analyzed 238 cases of patients with spine trauma who had emergency surgery. Three variables were significantly associated with the risk of perioperative blood transfusion: thoracolumbar spine injury, a preoperative hematocrit < 35%, and an Injury Severity Score > 20. Among the 118 patients who received blood transfusions, 53 benefitted from intraoperative blood salvage using the Cell-Saver apparatus (Cell-Saver group) and 65 did not (control group). The Cell-Saver enabled a 47% reduction in homologous blood requirements (743 ± 1191 mL vs. 1403 ± 1453 mL,p<0.008) and a 45% reduction in the number of patients who received homologous blood (45% vs. 82%,p<0.001). Between these two groups, no significant differences were observed in the evolution of hematocrit, platelet count, and hemostasis values, but a slight increase in postoperative blood loss was noted in the Cell-Saver group (465 ± 383 mL vs. 301 ± 292 mL,p<0.01). In conclusion, the efficiency of intraoperative blood salvage in emergency surgery for spine trauma is high and similar to that previously reported in elective spine surgery. The cost-effectiveness of this technique may be improved by appropriate selection of the patient.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

We prospectively evaluated the patterns of pulmonary structural and functional changes in 100 consecutive surgical intensive care unit trauma patients who had (1) emergent major surgery, (2) a pelvic fracture, or (3) two or more major long bone fractures. For each patient, arterial blood gas measurements (ABGs), central venous pressure (CVP), pulmonary capillary occlusion pressure (PAOP), thoracic compliance, arterial oxygen tension/fraction of inspired oxygen (PAo2/Fio2), pulmonary venous admixture (Qs/Qt), and portable chest roentgenograms were sequentially tracked. The senior staff radiologist interpreted all chest roentgenograms. Pulmonary infiltration was quantitated in each of six fields using a scale ranging from 0 to 4, with 0 being no infiltration and 4 being the maximum. Adult respiratory distress syndrome (ARDS) was defined as follows: Qs/Qt > 20%, PAo2/Fio2< 250 or both; dependence on mechanical ventilation for life support for >24 hours; PAOP or CVP or both <20 mm Hg; and thoracic compliance <50 mL/cm H2O. Time zero (T0) the time of onset of ARDS, was defined as the time these criteria were met. Eighty-three of 100 study group patients had penetrating injuries, and 17 were admitted with blunt trauma. Fifty-one of 100 patients developed ARDS: 36 of 51 died. Only 4 of 49 (8%) patients without ARDS died. The injured lungs of patients with and without ARDS had similar amounts of infiltration over most measured time intervals. The noninjured lungs of the ARDS patients, however, had significantly greater infiltration than those without ARDS at T0and over subsequent time intervals. Before T0, the total infiltration of the injured lungs was significantly greater than that for the noninjured lungs in both the ARDS and nonARDS patient groups (4.5 ± 0.6 vs. 0.7 ± 0.2 and 2.4 ± 0.4 vs. 0.4 ± 0.3, respectively). The infiltration in the injured and noninjured lungs in both groups converged at T0and remained similar for several days. We conclude that pulmonary infiltration develops simultaneously with lung dysfunction in trauma patients with evolving ARDS. Densities associated with ARDS are first visible in the upper and middle lung fields.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

The aim of this study was to search for early inflammatory mediators in severely traumatized patients that could predict the occurrence of adult respiratory distress syndrome (ARDS). We measured sequential plasma levels of tumor necrosis factor (TNF), interleukin 1 (IL-1), interleukin 6 (IL-6), interleukin 8 (IL-8), complement fragment C3a, and endotoxin. In addition, we measured sequentially the values of hemodynamics, oxygen transport, and pulmonary function. The temporal patterns seen in the patients who developed ARDS were compared with those who did not. In the patients who developed ARDS, the first observed findings were low cardiac index (Cl) and oxygen delivery (DO2) followed by progressive increases in IL-6, IL-8 and C3a levels, worsening of pulmonary function, and increases in hemodynamic values. The maximum values of IL-6, IL-8, and C3a occurred after the onset of ARDS. In the patients who did not develop ARDS, initial oxygen transport values were not low, the levels of IL-6, IL-8, and C3a decreased rapidly from their initial peaks, and there were no further increases in hemodynamic values. In both ARDS and nonARDS patients, no measurable quantities of TNF, IL-1, or endotoxin were found. We concluded that none of the mediators we measured reached their peaks before the onset of ARDS and none were found to be predictive of posttraumatic ARDS. However, these and other mediators may augment or intensify the development of ARDS.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID

摘要:

Thirty-five patients with traumatic patellar tendon ruptures treated with primary repair and with a neutralization wire were retrospectively reviewed. All the ruptures occurred in acute trauma; 12 of the patients (34%) had multiple injuries, and 19 had open wounds around the kinee joints. The diagnostic clues included a high-riding patella by palpation or seen on roentgenograms, hemarthrosis, a palpable gap over the tendon, and inability of patients of extend the knee actively. Using the criteria of Siwek and Rao, at follow-up 57% of outcomes were rated as excellent; 28.6% as good; and 14.2% as unsatisfactory. None of the 35 patients had a rerupture of the tendon. We conclude that primary repair with a neutralization wire can be a treatment of choice for traumatic patellar tendon ruptures.

ISSN:0022-5282    

出版商:OVID    

年代:1994

数据来源: OVID