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Biomedical subjects

E Abraham

Publications and source records attributed to E Abraham.

At least 55 records · Page 3Linked to original sources
PubMed1999

HMG-1 as a late mediator of endotoxin lethality in mice.

Endotoxin, a constituent of Gram-negative bacteria, stimulates macrophages to release large quantities of tumor necrosis factor (TNF) and interleukin-1 (IL-1), which can precipitate tissue injury and lethal shock (endotoxemia). Antagonists of TNF and IL-1 have shown limited efficacy in clinical trials, possibly because these cytokines are early mediators in pathogenesis. Here a potential late mediator of lethality is identified and characterized in a mouse model. High mobility group-1 (HMG-1) protein was found to be released by cultured macrophages more than 8 hours after stimulation with endotoxin, TNF, or IL-1. Mice showed increased serum levels of HMG-1 from 8 to 32 hours after endotoxin exposure. Delayed administration of antibodies to HMG-1 attenuated endotoxin lethality in mice, and administration of HMG-1 itself was lethal. Septic patients who succumbed to infection had increased serum HMG-1 levels, suggesting that this protein warrants investigation as a therapeutic target.

Animals↗
PubMed1999

Neutrophil apoptosis in the lung after hemorrhage or endotoxemia: apoptosis and migration are independent of IL-1beta.

Hemorrhage and endotoxemia are associated with neutrophil accumulation in the lungs and the development of acute inflammatory lung injury. Because alterations in the rate of apoptosis may affect the number and function of neutrophils in the lungs, we determined the percentage of neutrophils undergoing apoptosis in the lungs of control, hemorrhaged, or endotoxemic mice. In control mice, 18.5 +/- 1.2% of pulmonary neutrophils were apoptotic. The proportion of apoptotic neutrophils in the lungs was significantly decreased 1 h after hemorrhage (6.5 +/- 1.6%, P < 0.01 compared to control) or endotoxemia (7.0 +/- 0.9%, P < 0.01 compared to control). Between 1 and 24 h after endotoxemia or hemorrhage, the proportion of apoptotic neutrophils in the lung remained significantly depressed compared to that in control, unmanipulated mice. By 48 h, the proportion of apoptotic neutrophils returned to baseline levels in the lungs of hemorrhaged (21.4 +/- 1.4%) or endotoxemic (16.4 +/- 1. 6%) mice. Lung neutrophil IL-1beta mRNA was significantly increased from that of control mice [i.e., 0.12 +/- 0.06 relative absorbance units (RAU)] 1 h after hemorrhage (5.19 +/- 0.068 RAU, P < 0.05 compared to control) or endotoxemia (8.90 +/- 1.53 RAU, P < 0.01 compared to control). In IL-1beta-deficient mice, there was no significant difference in lung neutrophil apoptosis or neutrophil entry into the lung after hemorrhage or endotoxemia compared to wild-type mice. Our results show that apoptosis among lung neutrophils is decreased for more than 24 h after hemorrhage or endotoxemia. Although IL-1beta expression is increased in lung neutrophils under these conditions, IL-1beta is not responsible for either the influx of neutrophils into the lung or the reduction of apoptosis in neutrophil populations after hemorrhage or endotoxemia.

Animals↗
PubMed1999

Osteosarcoma of the sella.

Primary osteosarcoma of the skull is rare. Osteosarcoma arising from the sellar region is extremely uncommon. The case of a 38-year-old man with osteosarcoma of the sella is described, and the literature is reviewed. The patient was treated with surgery followed by aggressive chemotherapy and radiotherapy. Currently he is in remission at 12 months.

Adult↗
PubMed1999

Microbiologic findings and correlations with serum tumor necrosis factor-alpha in patients with severe sepsis and septic shock.

To understand the microbiology of sepsis and its relationship with tumor necrosis factor (TNF)-alpha, 444 septic patients were studied in a phase II clinical trial. In total, 270 (61%) 444 of episodes were microbiologically documented. The most common isolates were Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae. In some patients, obligate anaerobes were isolated in pure culture. Data on baseline TNF-alpha (n=409) showed that the geometric mean TNF-alpha concentrations in patients with severe sepsis and in those with late shock were 41 pg/mL (range, 5-3310) and 58 pg/mL (range, 5-1870), respectively. Patients with a positive culture had significantly higher TNF-alpha levels (65.9 vs. 29.2 pg/mL, P=.0001). Patients with a pure gram-negative infection had significantly higher TNF-alpha levels than those with a pure gram-positive or mixed infection, especially in the late shock group (142.6, 64.0, and 52.8 pg/mL, respectively, P=.004). These results provide further support for the concept that patients with sepsis are a heterogeneous group that require more precise definition.

Adolescent↗
PubMed1999

Liposomal prostaglandin E1 (TLC C-53) in acute respiratory distress syndrome: a controlled, randomized, double-blind, multicenter clinical trial. TLC C-53 ARDS Study Group.

OBJECTIVE: To evaluate the safety and efficacy of an intravenous liposomal dispersion of prostaglandin E1 as TLC C-53 in the treatment of patients with acute respiratory distress syndrome (ARDS). DESIGN: Randomized, prospective, multicenter, double-blind, placebo-controlled, phase III clinical trial. SETTING: Forty-seven community and university-affiliated hospitals in the United States. PATIENTS: A total of 350 patients with ARDS were enrolled in this clinical trial. INTERVENTION: Patients were prospectively randomized in a 1:1 ratio to receive either liposomal prostaglandin E1 or placebo. The study drug was infused intravenously for 60 mins every 6 hrs for 7 days starting with a dosage of 0.15 microg/kg/hr. The dose was increased every 12 hrs until the maximal dose (3.6 microg/kg/hr) was attained or intolerance to further increases developed. Patients received standard aggressive medical/surgical care during the infusion period. OUTCOME MEASURES: The primary outcome measure was the time it took to wean the patient from the ventilator. Secondary end points included time to improvement of the PaO2/FIO2 ratio (defined as first PaO2/FIO2 > 300 mm Hg), day 28 mortality, ventilator dependence at day 8, changes in PaO2/FIO2, incidence of and time to development/resolution of organ failure other than ARDS. RESULTS: A total of 348 patients could be evaluated for efficacy. The distribution of variables at baseline describing gender, lung injury scores, Acute Physiology and Chronic Health Evaluation II scores, PaO2/FIO2, pulmonary compliance, and time from onset of ARDS or from institution of mechanical ventilation to the first dose of study drug was similar among patients in the liposomal prostaglandin E1 (n = 177) and the placebo (n = 171) treatment arms. There was no significant difference in the number of days to the discontinuation of ventilation in the liposomal prostaglandin E1 group compared with the placebo group (median number of days to off mechanical ventilation, 16.9 in patients receiving liposomal prostaglandin E1 and 19.6 in those administered placebo; p = .94). Similarly, mortality at day 28 was not significantly different in the two groups (day 28 mortality, 57 of 176 (32%) in the liposomal prostaglandin E1 group and 50 of 170 (29%) in patients receiving placebo; p = .55). In contrast, treatment with liposomal prostaglandin E1 was associated with a significantly shorter time to reach a PaO2/FIO2 ratio of >300 mm Hg (median number of days to reaching a PaO2/FIO2 ratio >300 mm Hg: 9.8 days in the liposomal prostaglandin E1 group and 13.7 days in patients receiving the placebo; p = .02). Among the subgroups examined, time to off mechanical ventilation was significantly reduced in patients who received at least 85% of a full dose (i.e., > 45.9 microg/kg) of liposomal prostaglandin E1 (median number of days to discontinuation of ventilation, 10.3 in the liposomal prostaglandin E1 group and 16.3 days in patients receiving placebo; p = .05). The overall incidence of serious adverse events was not significantly different in the liposomal prostaglandin E1 (40%) or placebo-treated (37%) groups. Drug-related adverse events of all kinds were reported in 69% of the patients receiving liposomal prostaglandin E1 compared with 33% of the placebo group, with hypotension and hypoxia (occurring in 52% and 24% of the liposomal prostaglandin E1-treated patients, respectively, and 17% and 5% of the placebo-treated patients, respectively) being noted most frequently. CONCLUSIONS: In the intent-to-treat population of patients with ARDS, treatment with liposomal prostaglandin E1 accelerated improvement in indexes of oxygenation but did not decrease the duration of mechanical ventilation and did not improve day 28 survival.

Adult↗
PubMed1999

Pharmacokinetics of a clarithromycin suspension administered via nasogastric tube to seriously ill patients.

The pharmacokinetics of clarithromycin and its 14-(R)-hydroxylated metabolite were studied on two separate occasions after nasogastric administration of 500 mg of a clarithromycin suspension to 16 seriously ill adults in an intensive care unit. The clarithromycin suspension appeared to be adequately absorbed, and the pharmacokinetics of neither clarithromycin nor 14-(R)-hydroxyclarithromycin differed significantly between the two dosing periods. No substantial differences in pharmacokinetics were observed compared to previously published studies of other adult populations. Minimal intrapatient variability of pharmacokinetic parameters was observed in these seriously ill patients.

Adult↗
PubMed1999

Effects of endogenous and exogenous catecholamines on LPS-induced neutrophil trafficking and activation.

Endotoxemia produces elevations in catecholamine levels in the pulmonary and systemic circulation as well as rapid increases in neutrophil number and proinflammatory cytokine expression in the lungs. In the present experiments, we examined the effects of endogenous and exogenous adrenergic stimulation on endotoxin-induced lung neutrophil accumulation and activation. Levels of interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, and macrophage inflammatory protein (MIP)-2 mRNAs were increased in lung neutrophils from endotoxemic mice compared with those present in lung neutrophils from control mice or in peripheral blood neutrophils from endotoxemic or control mice. Treatment with the beta-adrenergic antagonist propranolol before endotoxin administration did not affect trafficking of neutrophils to the lungs or the expression of IL-1beta, TNF-alpha, or MIP-2 by lung neutrophils. Administration of the alpha-adrenergic antagonist phentolamine before endotoxemia did not alter lung neutrophil accumulation as measured by myeloperoxidase (MPO) levels but did result in significant increases in IL-1beta, TNF-alpha, and MIP-2 mRNA expression by lung neutrophils compared with endotoxemia alone. Administration of the alpha1-adrenergic agonist phenylephrine before endotoxin did not affect trafficking of neutrophils to the lungs but was associated with significantly increased expression of TNF-alpha and MIP-2 mRNAs by lung neutrophils compared with that found after endotoxin alone. In contrast, treatment with the alpha2-adrenergic agonist UK-14304 prevented endotoxin-induced increases in lung MPO and lung neutrophil cytokine mRNA levels. The suppressive effects of UK-14304 on endotoxin-induced increases in lung MPO were not affected by administration of the nitric oxide synthase inhibitor N-nitro-L-arginine methyl ester. These data demonstrate that the initial accumulation and activation of neutrophils in the lungs after endotoxemia can be significantly diminished by alpha2-adrenergic stimulation. Therapy with alpha2-adrenergic agents may have a role in modulating inflammatory pulmonary processes associated with sepsis-induced acute lung injury.

Adrenergic alpha-Agonists↗
PubMed1999

Effects of lisofylline on hyperoxia-induced lung injury.

Lisofylline [1-(5R-hydroxyhexyl)-3,7-dimethylxanthine] decreases lipid peroxidation in vitro and in vivo suppresses proinflammatory cytokine expression in models of lung injury due to sepsis, blood loss, and oxidative damage. In the present experiments, we used a murine hyperoxia model to examine the effects of lisofylline on the activation of nuclear transcriptional regulatory factors [nuclear factor-kappaB and cAMP response element binding protein (CREB)], the expression of proinflammatory cytokines in the lungs, and the circulating levels of oxidized free fatty acids as well as on hyperoxia-induced lung injury and mortality. Treatment with lisofylline inhibited hyperoxia-associated increases in tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 in the lungs as well as decreased the levels of hyperoxia-induced serum-oxidized free fatty acids. Although hyperoxic exposure produced activation of both nuclear factor-kappaB and CREB in lung cell populations, only CREB activation was reduced in the mice treated with lisofylline. Lisofylline diminished hyperoxia-associated increases in lung wet-to-dry weight ratios and improved survival in animals exposed to hyperoxia. These results suggest that lisofylline ameliorates hyperoxia-induced lung injury and mortality through inhibiting CREB activation, membrane oxidation, and proinflammatory cytokine expression in the lungs.

Animals↗
PubMed1999

Impact of immunomodulating therapy on morbidity in patients with severe sepsis.

We assessed the impact, over a 28-d period, of therapy with the tumor necrosis factor (TNF) neutralizing receptor fusion protein (p55-IgG) on the incidence of end-organ failures in patients with severe sepsis or early septic shock in a subgroup of 165 patients recruited into a randomized, multicenter clinical trial to receive placebo (n = 78) or a single infusion of p55-IgG, 0.083 mg/kg (n = 87). At study entry, distribution of organ dysfunctions and other baseline characteristics were similar for the two study groups. Treatment with p55-IgG was associated with a trend toward reduced 28-d mortality (p = 0.07), a decreased incidence of new organ dysfunctions (relative risk [RR], 0.57; 95% confidence interval [95% CI] 0.29 to 1.10, p = 0.10), and a decreased overall incidence-density of organ failures (RR 0.65; 95% CI 0.60 to 0.71, p = 0.0001). Patients treated with p55-IgG had more organ failure-free days after study entry than those who received placebo. Average intensive care unit (ICU) stay was 2.6 d shorter (95% CI 0.2 to 5.0) for patients who received p55-IgG than for those who received placebo. For those patients who survived, this difference was 4.1 d (95% CI 1.6 to 6.6). Duration of ventilatory support was 3.2 d shorter (95% CI 0.1 to 6.3) among 28-d survivors who received p55-IgG, compared with placebo. In conclusion, in the population of septic patients studied, treatment with p55-IgG was associated with a trend toward shorter need for mechanical ventilatory support, a decreased length of stay (LOS), and a decreased incidence and duration of organ failure.

APACHE↗
PubMed1998

Double-blind randomised controlled trial of monoclonal antibody to human tumour necrosis factor in treatment of septic shock. NORASEPT II Study Group.

BACKGROUND: Despite the availability of potent antibiotics and intensive care, mortality rates from septic shock are 40-70%. We assessed the safety and efficacy of murine monoclonal antibody to human tumour necrosis factor alpha (TNF alpha MAb) in the treatment of septic shock. METHODS: In a randomised, multicentre, double-blind, placebo-controlled clinical trial in 105 hospitals in the USA and Canada, we randomly assigned 1879 patients a single infusion of 7.5 mg/kg TNF alpha MAb (n=949) or placebo (0.25% human serum albumin n=930). Our main outcome measurement was the rate of all-cause mortality at 28 days. FINDINGS: 382 (40.3%) of 948 patients who received TNF alpha MAb and 398 (42.8%) of 930 who received placebo had died at 28 days (95% CI -0.02 to 0.07, p=0.27). We found no association between therapy with TNF alpha MAb and increased rapidity in reversal of initial shock or prevention of subsequent shock. Similarly, baseline plasma interleukin-6 concentrations of more than 1000 pg/mL or detectable circulating TNF concentrations were not associated with improvement in survival after TNF alpha MAb therapy. Coagulopathy but not other organ or system failures, was significantly decreased in the TNF alpha MAb group compared with placebo (day 7, p<0.001; day 28, p=0.005). Serious adverse events were reported in 55.2% of patients given placebo and 54.1% in the TNF alpha MAb group. INTERPRETATION: We did not find an improvement in survival after septic shock with TNF alpha MAb. Therapy not solely dependent on TNF alpha blockade may be required to improve survival.

Adult↗
PubMed1998

Neutrophils are major contributors to intraparenchymal lung IL-1 beta expression after hemorrhage and endotoxemia.

Acute lung injury and the acute respiratory distress syndrome (ARDS) are significant causes of morbidity and mortality following sepsis and hemorrhage. Increased IL-1beta production in the lung is important in the development of acute inflammatory lung injury. Although neutrophils are an important component of the inflammatory response that characterizes acute lung injury, there is little information to suggest that they are capable of initiating cytokine-mediated immune responses in the lung. To explore the role of neutrophils in the early stages of acute lung injury, we examined IL-1beta production by mouse lung neutrophils after hemorrhage and endotoxemia. There was a significant increase in IL-1beta expression among intraparenchymal pulmonary neutrophil/mononuclear cells (IPNMC) 1 h after hemorrhage or endotoxemia. IL-1beta was detected only in a neutrophil-rich fraction of the IPNMC, but not in T and B lymphocytes positively selected from the IPNMC. Cyclophosphamide (CTX)-treated neutropenic mice expressed significantly less IL-1beta in IPNMC after hemorrhage or endotoxemia compared with CTX-untreated controls. Immunohistochemical analysis of lung sections from mice after hemorrhage or endotoxemia revealed IL-1beta expression in infiltrating neutrophils. These data indicate that IL-1beta-producing neutrophils traffic to the lungs rapidly in response to hemorrhage or endotoxemia and support the concept that proinflammatory cytokine production by lung neutrophils may contribute to the development of lung injury after blood loss and sepsis.

Animals↗