摘要:

This prospective clinical study was conducted to determine whether S 100 B is a reliable serum marker for traumatic brain injury (TBI) with and without multiple trauma. Fifty-five trauma patients (Injury Severity Score [ISS] ≥24 and Glasgow Coma Score [GCS] ≤8) were classified by radiography, computer tomography, ultrasound, and neurology as TBI without multiple trauma (n = 23), TBI with multiple trauma (n = 23), or multiple trauma without TBI (n = 9). S 100 B was measured initially after trauma and daily for a maximum of 21 days. Both survivors and nonsurvivors had markedly increased S 100 B initially. All survivors returned to normal or moderately increased S 100 B levels within the first 48 h after trauma. In contrast, all nonsurvivors of isolated TBI had S 100 B values that either increased consistently or dropped and then increased again 48 h after the initial increase after trauma. There was no relationship between localization, extent, or severity of TBI and S 100 B. According to receiver operating characteristic curve analysis and calculation of the area under the curve (AUC), S 100 B is equally accurate for mortality prediction at 24, 48, and 72 h after trauma and is most accurate >84 h after trauma. Sensitivity/specificity for mortality prediction are more accurate in TBI without multiple trauma (AUC 0.802–0.971) than in TBI with multiple trauma (AUC 0.693–0.783). Thus, though S 100 B may be a reliable marker of brain damage in TBI without multiple trauma 24 h after trauma and thereafter, it appears to be less reliable in TBI with multiple trauma.

ISSN:1073-2322    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

TNFR-1 (p55) and Fas share a death domain which is critical for apoptosis signaling whereas TNFR-p55 and TNFR-2 (p75) can activate NF-&kgr;B leading to anti-apoptotic proteins expression such as A1. The purpose of this study was to elucidate the role(s) of TNFR-p55 and TNFR-p75 in Fas-mediated neutrophil apoptosis and A1 expression in a mouse model of endotoxemia. Gene knockout (KO) (p55−/−, p75−/−, p55−/−/p75−/−) or wild type (WT) mice were injectedi.p.with saline or LPS (4 &mgr;g/g) followed by collecting peripheral blood after 24 h. Neutrophil apoptosis was assessed by propidium iodide staining using two-color flow cytometry with granulocyte-specific Gr1-FITC after 6-h whole blood culture with or without Fas agonist Jo2 (300 ng/ml) in the presence or absence of cycloheximide (CHX, 30 &mgr;g/ml). Membrane-associated receptors (Fas, TNFR-p55 and TNFR-p75) and cytoplasmic A1 expression of freshly isolated neutrophils were assessed by one-color flow cytometry and western blotting respectively. Compared with the group-WT/Sal, Jo2 induced apoptosis only in the presence of CHX (J+C). J+C-induced apoptosis was significantly lower in the group-p55−/−/Sal and p55−/−/p75−/−/Sal but not in the group-p75−/−/Sal. J+C-induced apoptosis was inhibited similarly in all the LPS-injected WT and KO mice. Strong A1 expression was also induced similarly in all the LPS-injected WT and KO mice. Fas and TNFR-p55 expression was normal and TNFR-p75 was significantly increased in all the LPS-injected WT and KO mice although absence of the appropriate surface receptors was confirmed in the KO mice. We conclude that p55 normally plays a proapoptotic role, but p75 appears to play a minimal role in Fas-mediated neutrophil apoptosis. During endotoxin-induced systemic inflammation, both TNFR-p55 and TNFR-p75 appear to be of minimal importance for modulation of Fas-mediated apoptosis and associated A1 protein expression despite normal Fas/TNFR-p55 and increased TNFR-p75 expression in neutrophils.

ISSN:1073-2322    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Hemorrhage-induced vascular hyporeactivity to norepinephrine (NE) and the possible effector roles of nitric oxide (NO) and endothelin (ET) were investigated in different vascular beds of rats. Under urethane anesthesia, rats (n = 7 per group) were hemorrhaged to a mean arterial pressure (MAP) of 50 mm Hg for 60 min. A group of rats was pretreated with either NG-nitro-L-arginine methyl ester (10 mg/kg), an NO synthase inhibitor, or PD142893 (0.1 mg/kg), an ET receptor antagonist 15 min before the end of the hypotensive period. Operated, euvolemic rats served as controls. The responses of MAP and the blood flow of the superior mesenteric (SMA), celiac (CA), left renal (LRA), and left femoral arteries (LFA) to NE (3 &mgr;g/kg, i.v.) were measured at baseline (prehemorrhage), at the end of the hypotensive period (0 h), and at 1, 2, and 4 h after the end of the hypotensive period. The pressor responses to NE on MAP at 0, 1, 2, and 4 h in the 60-min hemorrhage groups were reduced to 45.9%, 37.8%, 29.2%, 18.4% of baseline pressor response, respectively. At these same times, the fall in blood flow in response to NE in SMA, CA, LRA, and LFA was significantly blunted (P< 0.01). This loss of responsiveness in CA and LFA was more severe than in SMA and LRA (P< 0.05–P< 0.01). Pretreatment with L-NAME or PD142893 significantly improved the pressor response of MAP and the blood flow responses of the four arteries to NE (P< 0.01). Hypotension at 50 mm Hg for 60 min resulted in an apparent loss of vascular reactivity to NE, and the four vasculatures studies were not affected to the same extent. In addition, NO and ET appear to contribute to the loss of vascular reactivity in different vasculatures in hemorrhagic shock.

ISSN:1073-2322    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

We investigated, in a well-established canine model of human sepsis, the effects of two different techniques of sympathetic blockade during bacterial peritonitis on pain relief, hemodynamics, and survival rate. Twenty-two purpose-bred beagles (12–28 months old, weighing 10–12 kg) were studied. Fourteen animals received an epidural infusion of bupivicaine and morphine, and the other eight received either a celiac plexus block (n = 4) or a sham block (n = 4). Eighteen of the 22 animals received an intraperitoneal challenge ofEscherichia coli(1–10 × 109CFU kg−1body weight). At comparable doses of intraperitoneal-implantedE. coli(2.5–5 × 109CFU kg−1body weight), the addition of sympathetic blockade produced a synergistic decrease in survival times (P= 0.002) and mean left ventricular ejection fraction (P= 0.008), and increase in creatinine levels (P= 0.02). There was also a significant increase in tumor necrosis factor (TNF) levels (P= 0.004) and decrease in blood endotoxin clearance (P= 0.006) associated with sympathetic blockade during sepsis. The celiac plexus-blocked animals had no improvement in pain scores, and subjectively looked clinically worse than animals with sepsis without a celiac plexus block. In contrast, the epidural block was effective in blocking the pain and discomfort associated with low lethality doses of intraperitoneal bacteria reflected by no increase in pain scores compared with animals not receiving bacterial challenge. This study shows that during severe bacterial peritonitis, maintenance of sympathetic tone irrespective of pain relief provided is necessary for clearance of bacterial toxins, control of proinflammatory mediator release, hemodynamic stability, and survival.

ISSN:1073-2322    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

The final common pathway involved in the cardiovascular alterations of septic shock is incompletely defined. The opening of KATPchannels is associated with vasorelaxation and alterations in cardiac contractility. This event may be triggered during septic shock by increased nitric oxide (NO) production, by a decreased intracellular content of ATP, or by a change in the transmembrane electrical potential. In the present study, we assessed the effects of glibenclamide, an agent that blocks the opening of KATPchannelsin vitro,on the contractile response of rat aortic rings to norepinephrine, andin vivoin anesthetized dogs, with or without exposure toEscherichia coliendotoxin.In vitro,glibenclamide decreased the contractile response to norepinephrine in the presence of endotoxin, provided that the endothelium was intact.In vivo,administration of 0.15 mg/kg increased systemic vascular resistance (SVR) in the absence of endotoxin only, and increased myocardial performance. A higher dose of 1 mg/kg increased SVR and decreased myocardial performance, both during endotoxic shock and in control conditions. Renal and mesenteric blood flows decreased, but the respective fractional flows were unchanged. Oxygen delivery decreased in both experimental conditions, but oxygen consumption decreased only in control conditions. Thein vitroobservations suggest that the opening of KATPchannels is involved in the regulation of vascular tone during endotoxemia, via an endothelium-dependent mechanism. As different effects of glibenclamide were observedin vivo,the importance of the opening of KATPchannels in endotoxic shock may be limited.

ISSN:1073-2322    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Intestinal epithelial barrier function is impaired after the exposure of enterocytes to proinflammatory cytokines. The mechanism(s) responsible for this phenomenon remain incompletely understood. We used cultured monolayers of Caco-2 enterocyte-like cells to characterize the effect of cytomix, a mixture of interferon-&ggr;, tumor necrosis factor-&agr;, and interleukin-1&bgr;, on the expression and localization of several tight junctions proteins. Cells were stimulated with cytomix in the presence or absence of 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), an NO· scavenger. Some cells were treated with (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl) amino]diazen-1-ium-1,2-diolate] (DETA-NONOate), an NO· donor. Tight junction protein expression was measured in cellular extracts by Western blotting and localized in cells using immunofluorescence. Steady-state mRNA levels were determined using semi-quantitative reverse-transcription polymerase chain reaction. Incubation of cells with DETA-NONOate or cytomix decreased epithelial barrier function, decreased expression of ZO-1 mRNA, decreased expression of ZO-1, ZO-3, and occludin protein, and increased expression of claudin-1 protein. The effects of cytomix on barrier function and tight junction protein expression were modulated by cPTIO. Cytomix caused incorrect subcellular localization of ZO-1, occludin, and claudin-1, and this was modulated by co-incubation with cPTIO. DETA-NONOate caused similar protein mislocalization as observed with cytomix. The effectiveness of cPTIO in maintaining tight junction protein expression and correct subcellular localization was less apparent at early time points (12 h) compared with later points, suggesting an NO·-independent effect of cytokines on barrier function. Thus, cytomix appears to increase the permeability of Caco-2 monolayers through NO·-dependent and -independent mechanisms that are associated with changes in the expression and/or targeting of proteins involved in tight junction function.

ISSN:1073-2322    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Tyrosine phosphorylation plays a critical role in signal transduction pathways in immune cells. Laser scanning cytometer (LSC), a newly developed microscope-based cytofluorometer, may overcome shortcomings of Western blotting and flow cytometry in the detection of intracellular signaling transduction. The aims of this study were to visualize and quantitate intracellular phosphotyrosine in the peritoneal cells harvested from diet-restricted mice by LSC. In addition, using LSC, we identified the main cell type with activated tyrosine phosphorylation in response to an inflammatory stimulus and we investigated the intracellular distribution of tyrosine phosphorylation within the peritoneal macrophages. Mice were assigned to thead libitumand diet-restricted, i.e., 75% restricted food intake, groups. After 7 days of pair feeding, the peritoneal cells were harvested. Tyrosine phosphorylation in the harvested cells with eitherN-formyl-methionyl-leucyle-phenylalanine (fMLP) or lipopolysaccharide (LPS) stimulation was examined using LSC. Tyrosine phosphorylation of peritoneal cells from the diet-restricted group was significantly higher than that from thead libitumgroup, regardless of stimulation. Stimulation of peritoneal cells with either fMLP or LPS significantly increased tyrosine phosphorylation in thead libitumgroup, but not in the diet-restricted group. The relocation feature of LSC revealed that the cells with distinct tyrosine phosphorylation were macrophages. Topographic analysis demonstrated that phosphotyrosine was localized mainly in the cytoplasm of these cells. In summary, LSC revealed that tyrosine phosphorylation is mainly in the cytoplasm of the peritoneal macrophages and is deranged by diet restriction. LSC is a powerful tool for the study of intracellular signaling transduction.

ISSN:1073-2322    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Severe sepsis is accompanied by a profound depression of myocardial contractility. Leukocyte adhesion with subsequent local excess nitric oxide and reactive oxygen species production play major roles for this deleterious effect. We hypothesized that 3-deazaadenosine (c3Ado), an adenosine analogue with anti-inflammatory properties, prevents endotoxin-induced myocardial dysfunction. Wistar rats (8 per group) were treated withEscherichia colilipopolysaccharide (LPS, 1 mg/kg, i.p., strain 0111:B4) ± c3Ado (10 mg/kg, i.p.) 8 h before their hearts were harvested for isolated perfusion, histochemical analysis, or electrophoretic mobility shift assay. LPS induced a marked depression of left ventricular contractility. Immunohistochemistry revealed an upregulation of the adhesion molecules VCAM-1, ICAM-1, and P-selectin within the postcapillary venules. c3Ado inhibited VCAM-1 and ICAM-1 upregulation, but not P-selectin, and prevented cardiodepression. Electrophoretic mobility shift assay revealed inactivation of the transcription factor nuclear factor-&kgr;B and immunohistochemical staining for gp91phox, ED1, and CD11b demonstrated that c3Ado prevented local recruitment of monocytes and polymorph nuclear neutrophils to the myocardium. Accordingly, significantly fewer leukocytes producing nitric oxide or reactive oxygen species accumulated within the myocardium. Intravital microscopy of intestinal venules confirmed that LPS-induced adhesion of leukocytes was prevented by c3Ado. Additionally, c3Ado prevented LPS-induced elevation of serum tumor necrosis factor-&agr; levels. Our results imply that c3Ado may prove to have clinical relevance for inflammatory disease processes.

ISSN:1073-2322    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Preadministration of antioxidants such as pyrrolidine dithiocarbamate (PDTC) and phenylN-tert-butyl nitrone (PBN) protects animals from lethality in sepsis models. However, the requirement of preadministration greatly diminishes the clinical significance of these studies. Although the synthetic antioxidant PBN has been shown to effectively protect rodents from lethality in endotoxemia (lipopolysaccharide [LPS] model), preliminary screening indicates that pre- or postadministration of PBN does not protect in the rat cecal ligation and puncture (CLP) model. We show in this report that in a rat CLP model, the administration of PBN (150 mg/kg, 30 min after CLP) followed by the antibiotic imipenem (IMP; 10 mg/kg, 1 h after CLP) significantly increased survival compared with other single treatment groups. Previously, we have shown that PBN's protection in a rat LPS model is mediated by the overproduction of the anti-inflammatory cytokine interleukin (IL)-10. We show in this study that the increase in survival found in the PBN + IMP-treated group was abrogated by immunoneutralization with anti-IL-10 antibody, indicating that endogenous IL-10 is an effective protective factor. Plasma LPS levels were shown to be elevated after imipenem treatment, and the increased LPS level could have assisted to overproduce endogenous IL-10, as in the case of the PBN-treated LPS model. Statistical analysis indicated that the increase of IL-10 in PBN + IMP-treated group at early time period has significant association to the improvement of survival.

ISSN:1073-2322    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Candida albicansis a pleomorphic fungus with budding yeast and filamentous forms, and is a frequent cause of complicating infections in patients who are postsurgical, in shock, and have trauma. Many cases of systemic candidiasis are thought to originate from the intestine, but it is unclear if the filament or the yeast is the more invasive form. BecauseC. albicansis relatively noninvasive and because mesenteric ischemia is thought to facilitate extraintestinal microbial dissemination, wild-typeC. albicansCAF2 and mutant HLC54 (defective in filament formation) were orally inoculated into antibiotic-treated mice that were housed exclusively in room air, or were intermittently exposed to 10% oxygen for 1-h intervals. Both strains ofC. albicanscolonized the cecum in similar numbers (approximately 106.7/g).C. albicanstranslocation to the draining mesenteric lymph nodes was not detected in mice inoculated with CAF2 (normoxic or hypoxic) or in normoxic mice inoculated with HLC54, but was detected in 33% (P< 0.01) of hypoxic mice inoculated with HLC54. Using Caco-2 and HT-29 enterocytes cultivated on plastic dishes and pretreated for 48 h in 10% oxygen, adherence ofC. albicansHLC54 was decreased compared with wild-type CAF2, and hypoxia had no noticeable effect on adherence of either CAF2 or HLC54. Using enterocytes cultivated on permeable 8-&mgr;m filters, transepithelial migration ofC. albicansCAF2 and HLC54 appeared similar. Thus,C. albicansHLC54 (defective in filament formation) was more invasive in hypoxic mice compared with wild-type CAF2, and host factors (e.g., mesenteric ischemia) rather than an innate ability to interact with enterocytes might play a more important role in extraintestinal dissemination ofC. albicansyeast forms.

ISSN:1073-2322    

出版商:OVID    

年代:2003

数据来源: OVID