Search PubMed⌕ Search

Biomedical subjects

E E Moore

Publications and source records attributed to E E Moore.

At least 109 records · Page 6Linked to original sources

Critical analysis of two decades of experience with postinjury emergency department thoracotomy in a regional trauma center.

BACKGROUND: Despite numerous studies, no clear consensus exists for the optimal use of emergency department thoracotomy (EDT). As such, we have continued to critically review our experience with EDT during the last 23 years to clarify indications for EDT and evaluate its cost-effectiveness. METHODS: This was a retrospective review of 950 EDTs performed at our regional Level I trauma center during the last 23 years. Cost-benefit ratios were calculated using standardized models. RESULTS: In 23 years, 950 patients underwent postinjury thoracotomy. We were able to obtain the complete medical records for 868 patients (91%). Overall survival was 4.4%, with 3.9% surviving functionally intact. All survivors of blunt trauma had either palpable pulse or recorded blood pressure in the field. Blunt trauma functional survival when field vital signs were present was 2.5%. Of note, 26.5% of our functional survivors sustained penetrating injuries and had no pulse or blood pressure in the field. Stab wounds to the chest and gunshot wounds to the abdomen were the two mechanisms of injury most likely to be survived. The benefit-charge ratio was strongly in favor of performing EDT at 5.6:1; it was 1.8:1 if adjusted for the cost of maintaining all neurologically injured survivors throughout their lifetime. CONCLUSION: EDT is efficacious and cost-effective for select patient populations. We suggest a key clinical pathway for the use of EDT that would reduce the number of procedures by at least 32% without changing the number of neurologically intact survivors.

Adolescent↗

Multiple organ failure can be predicted as early as 12 hours after injury.

BACKGROUND: The failure of therapies aimed at modulating systemic inflammatory response syndrome and decreasing multiple organ failure (MOF) has been attributed in part to the inability to identify early the population at risk. Our objective, therefore, was to develop predictive models for MOF at admission and at 12, 24 and 48 hours after injury. METHODS: Logistic regression models were derived in a data set with 411 adult trauma patients using indicators of tissue injury, shock, host factors, and the Acute Physiology Score-Acute Physiology and Chronic Health Evaluation III (APS-APACHE III). RESULTS: MOF was diagnosed in 78 patients (19%). Injury Severity Score, platelet count, and age emerged as predictors in all models. Transfused blood, inotropes, and lactate were significant predictors at 12, 24, and 48 hours, but not at admission. The APS-APACHE III emerged only in the 0- to 48-hour model and offered minimal improvement in predictive power. Good predictive power was achieved at 12 hours after injury. CONCLUSION: Postinjury MOF can be predicted as early as 12 hours after injury. The APS-APACHE III added little to the predictive power of tissue injury, shock and host factors.

APACHE↗

Prostaglandin E1 attenuates cytotoxic mechanisms of primed neutrophils.

In a recent clinical trial, liposomal prostaglandin E1 (PGE1) improved oxygenation, increased compliance, and decreased ventilator dependency in patients with adult respiratory distress syndrome (ARDS), thus renewing interest in PGE1 as a potential modulator of inflammation. The neutrophil (PMN) is believed to play a key role in the development of ARDS. Consequently, we investigated the effects of PGE1 on three components of the neutrophil inflammatory response: reactive oxygen species (ROS) generation, protease release, and surface expression of adhesion molecules. Human neutrophils were incubated with PGE1 and then primed with platelet-activating factor (PAF) and activation with N-formyl-methionyl-leucylphenylalanine (fMLP). PGE1 at a dose range of (10[-8] to 10[-5] M) attenuated primed/activated (PAF/fMLP) PMN superoxide anion generation and elastase release. In contrast, PGE1 doses > or =10[-5] M were required to attenuate PAF-stimulated neutrophil upregulation of CD11b/CD18 adhesion molecules. PGE1 also diminished the duration of the PAF-induced cytosolic calcium (Ca2+) flux. Our results suggest that plasma levels of PGE1 attained in patients with ARDS may attenuate ROS and protease neutrophil cytotoxicity but may not effectively block PMN-endothelial cell (EC) adhesion. This attenuation may occur through abrogation of the Ca2+ influx.

Alprostadil↗

ICAM-1-CD18 interaction mediates neutrophil cytotoxicity through protease release.

Interaction of the beta2-integrin complex on the polymorphonuclear neutrophil (PMN) with intercellular adhesion molecule-1 (ICAM-1) has been implicated in PMN-mediated cytotoxicity. This study examined interaction of the CD11a, CD11b, and CD18 subunits of the beta2-integrin with ICAM-1, transfected into Chinese hamster ovarian (CHO) cells to avoid effects of other adhesion molecules. Incubation of quiescent PMNs with wild-type and ICAM-1-transfected CHO cells produced nominal cell lysis. Similarly, when phorbol myristate acetate (PMA)-activated PMNs were incubated with wild-type CHO cells, minimal cytotoxicity was produced. However, when ICAM-1-transfected CHO cells were incubated with PMA-activated PMNs, 40% cell lysis occurred. Blockade with a monoclonal antibody (MAb) to ICAM-1 or MAbs to CD11a, CD11b, or CD18 reduced PMN-mediated cytotoxicity to baseline. To examine the role of adhesion in cytotoxicity, we studied beta2-integrin-mediated PMN adhesion to ICAM-1-transfected CHO cells and found that MAbs for CD11a, CD11b, and CD18 all abrogated PMN cytotoxicity despite disparate effects on adhesion. To assess the role of CD18, beta2-integrin subunits were cross-linked, and CD18 alone mediated protease release. Moreover, ICAM-1 was immunoprecipitated from transfected CHO cells and incubated with PMNs. This soluble ICAM-1 provoked elastase release, similar to PMA, which could be inhibited by MAbs to CD18 but not MAbs to other beta2-integrin subunits. In addition, coincubation with protease inhibitors eglin C and AAPVCK reduced PMN-mediated cytotoxicity to control levels. Finally, ICAM-1-transfected CHO cells were exposed to activated PMNs from a patient with chronic granulomatous disease that caused significant cell lysis, equivalent to that of PMNs from normal donors. Collectively, these data suggest that ICAM-1 provokes PMN-mediated cytotoxicity via CD18-mediated protease release.

Animals↗

The derivation and characterization of stromal cell lines from the bone marrow of p53-/- mice: new insights into osteoblast and adipocyte differentiation.

We have derived a series of clonal cell lines from the bone marrow of p53-/- mice that represent different stages of osteoblast and adipocyte differentiation. All cell lines show indefinite growth potential (>300 population doublings) and have generation times of 12-20 h. These cell lines have been grouped into three categories. The least mature clones are heterogeneous and appear to contain a subpopulation of stem cells, which can spontaneously generate foci that contain either adipocytes or mineralizing osteoblasts. The second category of clones are homogeneous and clearly correspond to mature osteoblasts because they express high levels of the anticipated osteoblastic markers in a stable fashion and cannot differentiate into adipocytes even in the presence of inducers. The clones in the third category are the most unique. Initially they appeared to correspond to mature osteoblasts because they express alkaline phosphatase in a homogeneous manner, secrete type I collagen, show a significant cyclic adenosine monophosphate response to parathyroid hormone, secrete osteocalcin, and mineralize extensively after only 4-7 days. However, in contrast to the mature osteoblasts, these clones can be induced to undergo massive adipocyte differentiation, and this differentiation is accompanied by the complete loss of expression of all osteoblastic markers except alkaline phosphatase. These observations indicate that some cells that have acquired all of the characteristics of mature osteoblasts can be diverted to the adipocyte pathway. Further characterization of these clones may be particularly relevant to osteoporotic conditions where increased adipocyte formation appears to occur at the expense of osteoblast formation.

Adipocytes↗

p38 mitogen-activated protein kinase inhibition attenuates intercellular adhesion molecule-1 up-regulation on human pulmonary microvascular endothelial cells.

BACKGROUND: Increased expression of pulmonary endothelial intercellular adhesion molecule-1 (ICAM-1) is obligatory to neutrophil adherence culminating in adult respiratory distress syndrome (ARDS). The p38 mitogen-activated protein kinases (MAPKs) have been established as crucial in leukocyte proinflammatory signaling, but their role in the endothelial cells remains ill defined. We hypothesized that p38 MAPK activity is integral to ICAM-1 up-regulation on pulmonary endothelium. METHODS: Human pulmonary microvascular endothelial cells (HMVECs) were grown to confluence and pretreated with either the tyrosine phosphorylation inhibitor herbimycin A (1 mumol/L or the p38 MAPK inhibitor SB 203580 (10(-7) to 10(-5) mol /L) for 6 hours. ICAM-1 expression was quantified by flow cytometry. Data expressed as mean fluorescence intensity. Western blotting was used to show p38 MAPK activity after stimulation with lipopolysaccharide (LOS) or tumor necrosis factor-alpha (TNF-alpha). RESULTS: Tyrosine phosphorylation inhibition with herbimycin A attenuated both LPS and TNF-alpha stimulated ICAM-1 up-regulation. Similarly, specific inhibition of p38 MAPK attenuated both LPS (10(-6) to 10(-5) mol/L SB203580) and TNF-alpha (10(-7) to 10(-5) mol/L SB203580) stimulated expression of ICAM-1 on HMVECs. Both LPS and TNF-alpha induced activation of p38 in HMVECs. CONCLUSIONS: Signaling through p 38 MAPKs contributes to LP and TNF-alpha stimulated ICAM-1 surface expression on HMVECs. Thus p38 MAPKs appear integral to both neutrophil and endothelial cell proinflammatory signaling and may be a potential therapeutic target in the treatment of ARDS.

Calcium-Calmodulin-Dependent Protein Kinases↗

Beta-adrenergic stimulation down-regulates neutrophil priming for superoxide generation, but not elastase release.

Platelet-activating factor (PAF) concordantly primes neutrophils (PMNs) for superoxide generation and elastase release. beta-Adrenergic stimulation of PMNs enhances cAMP-dependent protein kinase A (PKA) activity and has been shown to inhibit PAF-mediated NADPH-oxidase activity. PMN superoxide generation is thought to play a predominate microbicidal role, whereas elastase is known to mediate untoward PMN-endothelial interactions. We hypothesized that beta-adrenergic neutrophil stimulation has disparate effects on PAF-mediated PMN superoxide generation versus elastase release. Human PMNs were isolated using a standard Ficoll/Hypaque gradient. PMNs were then primed with PAF (200 nM) and activated with fMLP (1 microM). Subsets of PMNs were pretreated for 5 min with a beta agonist (10(-4) M isoprotereno) or an adenylate cyclase agonist (10(-5) M forskolin). Superoxide generation was determined by superoxide dismutase inhibitive cytochrome c reduction. Elastase activity was measured by the cleavage of n-methoxylsuccinyl-A-A-P-V-p-nitroanilide. Pretreatment with isoproterenol and forskolin yielded superoxide generation of 3.2 +/- 0.6 and 3.1 +/- 1.2 nmole/2.5 x 10(5) PMN/min compared to 9.0 +/- 0.6 nmole/2.5 x 10(5) PMN/min for PAF/fMLP alone, whereas isoproterenol and forskolin did not significantly affect PAF-mediated neutrophil elastase release, 22.4 +/- 5.3 and 24.0 +/- 3.6%, respectively, compared to 39.4 +/- 9.1% for PAF/fMLP alone. Disparate PMN signal transduction for superoxide generation versus elastase release may explain the SICU clinical paradox, in which patients are both susceptible to infection and vulnerable to PMN-mediated multiple organ failure.

Adrenergic beta-Agonists↗

Level of consciousness and memory during the intracarotid sodium amobarbital procedure.

Controversy exists regarding differential effects on consciousness of left/right cerebral inactivation via intracarotid amobarbital. Further, the effects of level of consciousness (LOC) on memory during the intracarotid sodium amobarbital procedure (IAP) are unclear. A modified version of the Glasgow Coma Scale altered to avoid the confounding effects of aphasia was employed to assess LOC in 97 patients during the IAP. A greater impairment in LOC occurred with left cerebral inactivation. Memory was more impaired following left hemisphere injections as well as from injections contralateral to seizure focus. Memory was correlated with LOC, and this effect was more prominent for right hemisphere injections and for injections ipsilateral to seizure focus. These findings support differential cerebral roles in consciousness and demonstrate that IAP memory performance may be affected by the patient's LOC.

Adolescent↗

Base deficit after major trauma directly relates to neutrophil CD11b expression: a proposed mechanism of shock-induced organ injury.

OBJECTIVE: To determine whether expression of neutrophil integrin receptors is related to the degree of post-traumatic shock. DESIGN: Data were collected prospectively on patients with major trauma admitted to the surgical intensive care unit. SETTING: Denver General Hospital, Colorado. PATIENTS AND PARTICIPANTS: 17 severely injured adults. MEASUREMENTS AND RESULTS: The mean fluorescence intensity and per cent positive of neutrophil integrin receptors CD11 b, CD18 and CD11 a, and systolic blood pressure, blood transfusion, lactate and base deficit as indices of shock. CD11 b expression on circulating neutrophils was increased 6 and 12 h after trauma. After correcting for the other shock indices, base deficit predicted CD11 b expression at 12 h. CD11 b expression was negatively correlated with the circulating neutrophil count. CONCLUSIONS: The degree of metabolic acidosis after trauma correlates directly with CD11 b receptor expression on circulating neutrophils. This relation may be the mechanism whereby post-traumatic shock results in neutrophil sequestration and neutrophil-mediated organ injury and failure.

Acidosis↗

Selective management of penetrating neck trauma based on cervical level of injury.

BACKGROUND: Selective surgical exploration of penetrating neck wounds is now the standard of care, but the safety and cost effectiveness of selective diagnostic testing remains controversial. We herein review our 18-year prospective evaluation of a progressively selective approach. PATIENTS AND METHODS: Since 1979, 312 patients sustained penetrating trauma to the anterior neck; 75% were stabbed and 24% were shot. Zone I was penetrated in 13%, zone II in 67%, and zone III in 20%. RESULTS: In all, 105 (34%) of the patients had early exploration (16% were nontherapeutic). Of the 207 (66%) observed, 1 (0.5%) required delayed exploration. Length of stay was 8.0 days following exploration, 5.1 days following negative exploration, and 1.5 days following observation. In the last 6 years, 40% have had adjunctive testing: 69% of zone I, 15% of zone II, and 50% of zone III injuries. CONCLUSION: Selective management of penetrating neck injuries is safe and does not mandate routine diagnostic testing for asymptomatic patients with injuries in zones II and III.

Humans↗

Prospective characterization and selective management of the abdominal compartment syndrome.

BACKGROUND: The abdominal compartment syndrome (ACS) is now recognized as a frequent confounder of surgical critical care following major trauma; however, few prospective data exist concerning its characterization, evolution, and response to decompression. METHODS: Acutely injured patients with an injury severity scale (ISS) score >15 requiring emergent laparotomy and intensive care unit (ICU) admission were prospectively evaluated for the development of ACS. The syndrome was defined as an intra-abdominal pressure (IAP) >20 mm Hg complicated by one of the following: peak airway pressure (PAP) >40 cm H2O, oxygen delivery index (DO2I) <600 mL O2/min/m2, or urine output (UO) <0.5 mL/kg/hr. Physiologic response to decompression was similarly documented prospectively. RESULTS: Over a 14-month period ending December 1995, 21 (14%) of 145 patients (ISS >15) requiring laparotomy and admitted to our surgical ICU developed ACS; mean age was 39 +/- 9 years; injury mechanism was blunt in 60%; ISS 26 +/- 6. At initial laparotomy, 67% underwent abdominal packing (57% for major liver injuries). Mean IAP was 27 +/- 2.3 mm Hg, and time from laparotomy to decompression was 27 +/- 4 hours; 24% were planned whereas the remaining were prompted by deteriorating organ function as defined above (cardiopulmonary in 43%; renal in 19%; both renal and cardiopulmonary in 14%). Following decompression, there was an increase in cardiac index, oxygen delivery, urine output, and static compliance while there was a decrease in pulmonary capillary wedge pressure, systemic vascular resistance, and peak airway pressure. CONCLUSIONS: The abdominal compartment syndrome occurs in a significant number of severely injured patients, and it develops quickly (27 +/- 4 hours). Cardiopulmonary deterioration is the most frequent reason prompting decompression. Timely decompression of the ACS results in improvements in cardiopulmonary and renal function. These data support the use of the proposed ACS grading system for selective management of the syndrome.

Abdomen↗

Nitric oxide attenuates platelet-activating factor priming for elastase release in human neutrophils via a cyclic guanosine monophosphate-dependent pathway.

BACKGROUND: Nitric oxide (NO) has proven benefits in treating adult respiratory distress syndrome (ARDS). The protective mechanism remains unclear, but cyclic guanosine monophosphate (cGMP)-dependent signal transduction pathways have been suggested. Our laboratory has implicated polymorphonuclear neutrophil (PMN) priming and subsequent activation in the pathogenesis of postinjury ARDS and has shown that NO inhibits superoxide anion production from activated PMNs. More recently, the pivotal role of elastase in PMN-mediated tissue injury has been emphasized. Consequently, our study hypothesis was that NO attenuates platelet-activating factor (PAF) priming for elastase release through a cGMP-dependent pathway in human PMNs. METHODS: PMNs isolated from human volunteers were preincubated with the NO donor 3-morpholinosydnonimine hydrochloride (SIN-1; 10(-6) to 10(-2) mol/L), cGMP (10(-3) mol/L), or the cell-permeable cGMP analog dibutyryl-cGMP (10(-3) mol/L) for 10 minutes. The cells were then primed with platelet-activating factor (PAF) 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine (200 nmol/L), which was followed by N-formyl-methionyl-leucyl-phenylalanine (fMLP) activation (1 mumol/L). Elastase release was measured by the cleavage of N-methoxysuccinyl-Ala-Ala-Pro-Val p-nitroanilide (AAPV-pNA). RESULTS: NO (through SIN-1) significantly attenuated elastase release from PAF-primed PMNs in a dose-dependent manner. Cell-permeable dibutyryl-cGMP attenuated PMN elastase release similar to NO, but cGMP (not cell-permeable) had no effect. CONCLUSIONS: NO attenuates elastase release from PAF-primed PMNs through an intracellular cGMP-dependent signal transduction pathway. These findings may partially explain the beneficial effects of NO in the treatment of postinjury ARDS and add to our knowledge of the complex intracellular pathways involved in NO/PMN interactions.

Adult↗

Adaptive and maladaptive mechanisms of cellular priming.

OBJECTIVE: The mechanisms of cellular priming resulting in both adaptive and maladaptive responses to subsequent injury and strategies for manipulating this priming to constructive therapeutic advantage are explored. BACKGROUND DATA: A cell is prepared or educated by an initial insult (priming stimulus). Investigations in both laboratory animals and humans indicate that cells, organs, and perhaps even whole patients respond differently to a proximal second insult ("second hit") by virtue of this prior environmental history. The opportunity to achieve the primed state appears to be conserved across almost all cell types. The initial stimulus transmits a message to the cellular machinery that influences the cell's response to a subsequent challenge. This response may result in an exaggerated inflammatory response in the case of the neutrophil (an often maladaptive process) or an improved tolerance to injury by the myocyte (adaptive response). Our global hypothesis is that cellular priming is a conserved, receptor-dependent process that invokes common intracellular targets across multiple cell types. We further postulate that these targets create a language based on the transient phosphorylation and dephosphorylation of intracellular enzymes that is therapeutically accessible. CONCLUSIONS: Priming is a conserved, receptor-dependent process transduced by means of intracellular targets across multiple cell types. The potential therapeutic strategies outlined involve the receptor-mediated manipulation of cellular events. These events are transmitted through an intracellular language that instructs the cell regarding its behavior in response to subsequent stimulation. Understanding these intracellular events represents a realistic goal of priming and preconditioning biology and will likely lead to clinical control of the primed state.

Adaptation, Physiological↗

Neutrophils mediate pulmonary vasomotor dysfunction in endotoxin-induced acute lung injury.

BACKGROUND: The major hemodynamic feature of endotoxin (ETX)-induced acute lung injury is pulmonary hypertension secondary to increased pulmonary vascular resistance. Endotoxin causes dysfunction of pulmonary vasorelaxation, which is associated with increased lung neutrophil accumulation. We hypothesized that neutrophils mediate the dysfunction of cGMP-mediated pulmonary vasorelaxation in acute lung injury. In a rat model of ETX-induced lung injury, our purpose was to determine the effect of neutrophil depletion on the following mechanisms of pulmonary vasomotor control: endothelium-dependent cGMP-mediated relaxation (response to acetylcholine) and endothelium-independent relaxation (response to sodium nitroprusside). METHODS: Rats were studied 6 hours after ETX (20 mg/kg). Neutropenia (< 75 neutrophils/microL) was induced with anti-neutrophil serum 24 hours before ETX. Saline injected rats were controls. Dose-response curves to acetylcholine and sodium nitroprusside were generated in isolated pulmonary artery rings preconstricted with phenylephrine (n = 10 rings/5 rats per group). Lungs were harvested (n = 4 rats/group) and lung neutrophil accumulation was assessed with a myeloperoxidase assay. RESULTS: Endothelium-dependent and -independent cGMP-mediated pulmonary vasorelaxation was dysfunctional in ETX-induced ALI. Neutrophil depletion prevented lung neutrophil accumulation and attenuated pulmonary vasomotor dysfunction after endotoxin. CONCLUSIONS: These data suggest that neutrophils contribute to pulmonary endothelium and smooth muscle dysfunction in acute lung injury induced by endotoxemia.

Acetylcholine↗

Evidence for early supply independent mitochondrial dysfunction in patients developing multiple organ failure after trauma.

OBJECTIVE: To determine whether early supply independent mitochondrial oxidative dysfunction occurs in trauma patients who develop multiple organ failure (MOF). DESIGN: Prospective focused observational trial. METHODS: High-risk patients were aggressively resuscitated while being continuously monitored by near infrared spectroscopy. Near infrared spectroscopy monitoring strips allow for a direct comparison of changes in tissue oxyhemoglobin levels (HbO2), which reflect local oxygen supply, and cytochrome a,a3 redox, which reflects mitochondrial oxygen consumption. Under normal conditions, HbO2 and a,a3 redox are tightly coupled. On the other hand, decoupled HbO2 and a,a3 redox is a sign of mitochondrial oxidative dysfunction. Outcomes included MOF, oxygen delivery, oxygen consumption, lactate, and the presence of decoupled HbO2 and a,a3 redox. RESULTS: Twenty-four high-risk patients were studied; nine (38%) developed MOF. At 12 hours of resuscitation, MOF and non-MOF patients did not have statistically different oxygen delivery and oxygen consumption, but lactate levels were significantly higher in MOF patients. Additionally, HBO2 and a,a3 redox were decoupled in eight (89%) MOF patients compared with two (13%) non-MOF patients (p < 0.05). CONCLUSION: Severely injured trauma patients who develop MOF preferentially display evidence of mitochondrial oxidative dysfunction early in the course of their resuscitation despite early goal-oriented maximization of oxygen delivery.

Adolescent↗

Predicting life-threatening coagulopathy in the massively transfused trauma patient: hypothermia and acidoses revisited.

BACKGROUND: Recalcitrant coagulopathy "the bloody vicious cycle," produces the majority of deaths after torso trauma. A model predicting this life-threatening complication may facilitate clinical decision-making. METHODS: We prospectively analyzed patients > 15 years old who received a massive transfusion (> 10 units of packed red blood cells (PRBC)/24 h) over a 2-year period. Excluding massive head injuries and pre-existing disease, the 58 study patients had a mean age = 35.4 years, Injury Severity Score (ISS) = 30.6, and PRBC = 24.2 units/24 h. RESULTS: Defined as prothrombin time of two times that of normal laboratory controls and partial thromboplastin time as two times that of normal laboratory controls, 27 patients (47%) developed life-threatening coagulopathy. Using a multiple logistic regression model, the four significant risk factors (with odds ratio) were (1) pH < 7.10 (12.3), (2) temperature < 34 degrees C (8.7), (3) ISS > 25 (7.7), and (4) systolic blood pressure < 70 mm Hg (5.8). The conditional probability of developing coagulopathy was ISS > 25 + systolic blood pressure < 70 mm Hg = 39%, ISS > 25 + temperature < 34 degrees C = 49%, ISS > 25 + pH < 7.10 = 49%; with all four risk factors the incidence was 98%. CONCLUSION: Postinjury life-threatening coagulopathy in the seriously injured requiring massive transfusion is predicted by persistent hypothermia and progressive metabolic acidosis.

Abdominal Injuries↗