Interactions between CBP, NF-kappaB, and CREB in the lungs after hemorrhage and endotoxemia

The transcriptional regulatory factor nuclear factor (NF)-kappaB has a central role in modulating expression of proinflammatory mediators that are important in acute lung injury. In vitro studies have shown that competition between NF-kappaB and cAMP response element binding protein (CREB) for binding to the coactivator CREB-binding protein (CBP) is important in regulating transcriptional activity of these factors. In the present study, we examined in vivo interactions between CBP, CREB, and NF-kappaB in hemorrhage- or endotoxemia-induced acute lung injury. Association of CBP with CREB or the p65 subunit of NF-kappaB increased in the lungs after hemorrhage or endotoxemia. Inhibition of xanthine oxidase before hemorrhage, but not before endotoxemia, decreased p65-CBP interactions while increasing those between CREB and CBP. These alterations in CREB-CBP and p65-CBP interactions were functionally significant because xanthine oxidase inhibition before hemorrhage resulted in increased expression of the CREB-dependent gene c-Fos and decreased expression of macrophage inflammatory protein-2, a NF-kappaB-dependent gene. The present results show that the coactivator CBP has an important role in modulating transcription in vivo under clinically relevant pathophysiological conditions.

Effects of propofol containing EDTA on mineral metabolism in medical ICU patients with pulmonary dysfunction

OBJECTIVE

To determine whether the addition of disodium edetate (EDTA) to propofol significantly alters mineral metabolism, adverse events, and outcome in critically ill medical patients with acute pulmonary dysfunction.

DESIGN

Multicentre, double-randomised, double-blind, comparative trial.

SETTING

Medical intensive care units of 5 health centres.

PATIENTS

A total of 85 haemodynamically stable men and women aged 18-81 years who had pulmonary dysfunction or adult respiratory distress syndrome as a primary diagnosis or complication and who were expected to require at least 48 hours of sedation and mechanical ventilation.

INTERVENTIONS

Patients were randomised to receive propofol with or without EDTA and then to 1 of 2 sedation levels: light (Modified Ramsay Sedation Scale [MRSS] score of 2 to 3) or deep (MRSS score of 4 to 5). Propofol was administered by continuous infusion at an initial rate of 5 microg/kg per min and titrated as needed.

MEASUREMENTS AND RESULTS

Approximately 63 % of patients had a high severity of illness as indicated by an Acute Physiology and Chronic Health Evaluation II score > or = 19. As expected, these patients had a higher mortality rate but did not require a higher dose of propofol or propofol with EDTA. Extensive evaluation of cation homeostasis showed that ionised calcium and magnesium concentrations remained remarkably stable during treatment. Total calcium concentration was low as a result of hypoalbuminemia. Parathyroid hormone (PTH) concentration was elevated in both study groups at baseline, on day 4, and at the end of sedation. There were no significant differences in electrolyte levels and no progression to renal dysfunction. There were also no significant differences in haemodynamic or adverse-event profiles. Treatment-related adverse events occurred in 5 patients in each group; 4 of these (in 3 patients receiving propofol and 1 patient receiving propofol with EDTA) were considered serious. Because a large percentage of patients experienced a change in sedation level, no analyses were performed using sedation level.

CONCLUSIONS

The addition of EDTA to propofol does not alter calcium and magnesium homeostasis in critically ill patients with acute pulmonary dysfunction. The reason for the elevation in PTH concentrations in such patients is not known.

Extracellular superoxide dismutase attenuates lung injury after hemorrhage

Reperfusion of the lung after hemorrhage generates free radicals such as superoxide (O(2)(.)) that may injure the lung; however, the relative importance of intracellular versus extracellular free radicals is unclear. The superoxide dismutases (SOD) are the primary enzymatic method to reduce superoxide. We examined whether lung-specific overexpression of extracellular superoxide dismutase (EC-SOD) would attenuate hemorrhage-induced lung injury. Wild-type mice and mice overexpressing the human EC-SOD gene with a lung-specific promoter were hemorrhaged by removing 30% of blood volume. After hemorrhage, the lung wet to dry weight ratios increased from 5.4 +/- 0.11 in unmanipulated control mice to 6.3 +/- 0.16 in wild-type mice, but to only 5.60 +/- 0.17 in the EC-SOD transgenic mice (p < 0.05 compared with hemorrhaged wild-type). Hemorrhage-induced lipid peroxidation, as assessed by lung F(2) isoprostanes, was lower in the EC-SOD transgenic mice (3.4 +/- 0.3 microg/lung) compared with wild-type mice (1.9 +/- 0.2 microg/lung; p < 0.05). Compared with wild-type, EC-SOD transgenic mice had attenuated the hemorrhage-induced increase in both pulmonary nuclear factor kappa B (NK-kappaB) activation (relative absorbance 1.1 +/- 0.2 for EC-SOD transgenic versus 2.5 +/- 0.1 for wild-type; p < 0.05) and myeloperoxidase activity (5.1 +/- 0.87 units/g for EC-SOD transgenic versus 11.3 +/- 1.8 units/g for wild-type; p < 0.01). Thus, overexpression of pulmonary EC-SOD in the mouse lung attenuates lung injury after hemorrhage.

Cadherins as predictive markers of nodal metastasis in breast cancer

Adhesion molecules, particularly cadherins play a pivotal role in cancer invasion and metastasis. Because the therapeutic management of tumors with and without nodal metastasis differs considerably, our idea was to identify tumors with metastatic potential. We studied the expression of E-cadherin and P-cadherin immunohistochemically in 51 cases of breast cancer that included 29 node-negative and 22 node-positive cases. Expression of the cadherins was mainly membranous, with cytoplasmic staining in a few lesions. Both E-cadherin and P-cadherin showed significant down-regulation of their expression in node-positive tumors in comparison to node-negative tumors. Logistic regression analysis revealed that the positive expression of E-cadherin and P-cadherin showed low odds ratios of 0.1 and 0.2, respectively, and were statistically significant. On multivariate analysis, both the cadherins were found to be of independent prognostic value. This suggests that cadherin expression could be a marker of nodal metastasis. An observation of interest was that the expression of E-cadherin and P-cadherin were highly correlated (correlation coefficient = 0.5873), which requires further evaluation for confirmation of a common regulatory pathway that could be activated in the early onset of nodal metastasis.

Lenercept (p55 tumor necrosis factor receptor fusion protein) in severe sepsis and early septic shock: a randomized, double-blind, placebo-controlled, multicenter phase III trial with 1,342 patients

OBJECTIVE

Phase III study to confirm a trend observed in a previous phase II study showing that a single dose of lenercept, human recombinant p55 tumor necrosis factor receptor-immunoglobulin G1 (TNFR55-IgG1) fusion protein, decreased mortality in patients with severe sepsis or early septic shock.

DESIGN

Multicenter, double-blind, phase III, placebo-controlled, randomized study.

SETTING

A total of 108 community and university-affiliated hospitals in the United States (60), Canada (6) and Europe (42).

PATIENTS

A total of 1,342 patients were recruited who fulfilled the entry criteria within the 12-hr period preceding the study drug administration.

INTERVENTION

After randomization, an intravenous dose of 0.125 mg/kg lenercept or placebo was given. The patient was monitored for up to 28 days, during which standard diagnostic, supportive, and therapeutic care was provided.

MEASUREMENTS AND MAIN RESULTS

The primary outcome measure was 28-day all-cause mortality. Baseline characteristics were as follows: a total of 1,342 patients were randomized; 662 received lenercept and 680 received placebo. The mean age was 60.5 yrs (range, 17-96 yrs); 39% were female; 65% had medical admissions, 8% had scheduled surgical admissions, and 27% had unscheduled surgical admissions; 73% had severe sepsis without shock, and 27% had severe sepsis with early septic shock. Lenercept and placebo groups were similar at baseline with respect to demographic characteristics, simplified acute physiology score II-predicted mortality, profiles of clinical site of infection and microbiological documentation, number of dysfunctioning organs, and interleukin-6 (IL-6) plasma concentration. Lenercept pharmacokinetics were similar in severe sepsis and early septic shock patients. Tumor necrosis factor was bound in a stable manner to lenercept as reflected by the accumulation of total serum tumor necrosis factor alpha concentrations. There were 369 deaths, 177 on lenercept (27% mortality) and 192 on placebo (28% mortality). A one-sided Cochran-Armitage test, stratified by geographic region and baseline, predicted 28-day all-cause mortality (simplified acute physiology score II), gave a p value of .141 (one-sided). Lenercept treatment had no effect on incidence or resolution of organ dysfunctions. There was no evidence that lenercept was detrimental in the overall population.

CONCLUSION

Lenercept had no significant effect on mortality in the study population.

Prevention of influenza and pneumococcal pneumonia in Canadian long-term care facilities: how are we doing?

BACKGROUND

Influenza and pneumococcal pneumonia are serious health problems among elderly people and a major cause of death in long-term care facilities. We describe the results of serial surveys of vaccination coverage and influenza outbreak management in Canadian long-term care facilities over the last decade.

METHODS

Cross-sectional surveys consisting of questionnaires mailed to all Canadian residential long-term care facilities for elderly people in 1991 and to a random sample of respondents in 1995 and 1999.

RESULTS

The response rates were 83% (430/515) in 1995 and 75% (380/506) in 1999. In 1999 the mean reported rates of influenza vaccination were 83% among residents and 35% among staff, and the mean rate of pneumococcal vaccination among residents was 71%; all 3 rates were significantly higher than those in 1991. The rates were also higher in facilities with an infection control practitioner than in those without such an individual (88% v. 82% for influenza vaccination among residents [p < 0.001], 42% v. 35% for influenza vaccination among staff [p = 0.008] and 75% v. 63% for pneumococcal vaccination among residents [p < 0.001]). Obtaining consent for vaccination on admission to the facility was associated with higher influenza and pneumococcal vaccination rates among residents (p = 0.04 and p < 0.001 respectively). Facilities with higher influenza vaccination rates among residents and staff reported lower rates of influenza outbreaks (p = 0.08 and 0.03 respectively). Despite recommendations from the National Advisory Committee on Immunization, only 50% of the facilities had policies for amantadine prophylaxis during influenza A outbreaks. Amantadine was judged effective in controlling 76% of the influenza A outbreaks and was discontinued because of side effects in 3% of the residents.

INTERPRETATION

Influenza and pneumococcal vaccination rates among residents and staff in Canadian long-term care facilities have increased over the last decade but remain suboptimal. Vaccination of residents and staff against influenza is associated with a reduced risk of influenza outbreaks. Amantadine is effective in controlling influenza outbreaks in long-term care facilities.

Activation of extracellular signal-regulated kinases, NF-kappa B, and cyclic adenosine 5'-monophosphate response element-binding protein in lung neutrophils occurs by differing mechanisms after hemorrhage or endotoxemia

Acute lung injury is frequently associated with sepsis or blood loss and is characterized by a proinflammatory response and infiltration of activated neutrophils into the lungs. Hemorrhage or endotoxemia result in activation of cAMP response element-binding protein (CREB) and NF-kappa B in lung neutrophils as well as increased expression of proinflammatory cytokines, such as TNF-alpha and macrophage-inflammatory peptide-2, by these cells. Activation of the extracellular regulated kinase (ERK) pathway occurs in stress responses and is involved in CREB activation. In the present experiments, hemorrhage or endotoxemia produced increased activation of mitogen-activated protein kinase kinase (MEK)1/2 and ERK2 (p42), but not of ERK1 (p44), in lung neutrophils. ERK1, ERK2, and MEK1/2 were not activated in peripheral blood neutrophils after hemorrhage or endotoxemia. Inhibition of xanthine oxidase led to further increase in the activation of MEK1/2 and ERK2 in lung neutrophils after hemorrhage, but not after endotoxemia. Alpha-adrenergic blockade before hemorrhage resulted in increased activation in lung neutrophils of MEK1/2, ERK1, ERK2, and CREB, but decreased activation of NF-kappa B. In contrast, alpha-adrenergic blockade before endotoxemia was associated with decreased activation of MEK1/2, ERK2, and CREB, but increased activation of NF-kappa B. Beta-adrenergic blockade before hemorrhage did not alter MEK1/2 or ERK1 activation in lung neutrophils, but decreased activation of ERK2 and CREB, while increasing activation of NF-kappa B. Beta-adrenergic inhibition before endotoxemia did not affect activation of MEK1/2, ERK1, ERK2, CREB, or NF-kappa B. These data indicate that the pathways leading to lung neutrophil activation after hemorrhage are different from those induced by endotoxemia.

Neutrophils as early immunologic effectors in hemorrhage- or endotoxemia-induced acute lung injury

Acute lung injury is characterized by accumulation of neutrophils in the lungs, accompanied by the development of interstitial edema and an intense inflammatory response. To assess the role of neutrophils as early immune effectors in hemorrhage- or endotoxemia-induced lung injury, mice were made neutropenic with cyclophosphamide or anti-neutrophil antibodies. Endotoxemia- or hemorrhage-induced lung edema was significantly reduced in neutropenic animals. Activation of the transcriptional regulatory factor nuclear factor-kappaB after hemorrhage or endotoxemia was diminished in the lungs of neutropenic mice compared with nonneutropenic controls. Hemorrhage or endotoxemia was followed by increases in pulmonary mRNA and protein levels for interleukin-1beta (IL-1beta), macrophage inflammatory protein-2 (MIP-2), and tumor necrosis factor-alpha (TNF-alpha). Endotoxin-induced increases in proinflammatory cytokine expression were greater than those found after hemorrhage. The amounts of mRNA or protein for IL-1beta, MIP-2, and TNF-alpha were significantly lower after hemorrhage in the lungs of neutropenic versus nonneutropenic mice. Neutropenia was associated with significant reductions in IL-1beta and MIP-2 but not in TNF-alpha expression in the lungs after endotoxemia. These experiments show that neutrophils play a central role in initiating acute inflammatory responses and causing injury in the lungs after hemorrhage or endotoxemia.

HMG-1 as a mediator of acute lung inflammation

Acute inflammatory lung injury is often a delayed complication of critical illness and is associated with increased mortality. High mobility group-1 (HMG-1) protein, in addition to its role as a transcriptional regulatory factor, has recently been identified as a late mediator of endotoxin lethality. In the present studies, HMG-1 given intratracheally produced acute inflammatory injury to the lungs, with neutrophil accumulation, the development of lung edema, and increased pulmonary production of IL-1beta, TNF-alpha, and macrophage-inflammatory protein-2. In endotoxin-induced acute lung inflammation, administration of anti-HMG-1 Abs either before or after endotoxin exposure decreased the migration of neutrophils to the lungs as well as lung edema. These protective effects of anti-HMG-1 were specific, because pulmonary levels of IL-1beta, TNF-alpha, or macrophage-inflammatory protein-2 were not decreased after therapy with anti-HMG-1. Together, these findings indicate that HMG-1 is a distal mediator of acute inflammatory lung injury.

Tissue factor inhibition and clinical trial results of tissue factor pathway inhibitor in sepsis

Tissue factor mediated pathways leading to microvascular thromboses and endothelial activation appear to play an important role in the development of multiple organ failure associated with severe sepsis. Tissue factor pathway inhibitor (TFPI) is an endogenous inhibitor of tissue factor associated coagulation cascades. In experimental models of severe sepsis, treatment with TFPI results in significant reduction in mortality. Similarly, a recently completed Phase II 210-patient study comparing placebo and infusions of TFPI showed trends toward a relative reduction in day 28 all-cause mortality in TFPI treated patients. These data suggest that coagulation cascades involving tissue factor contribute to organ dysfunction in critically ill septic patients. TFPI may be a useful therapy in improving outcome of severe sepsis.

Thirty years of clinical trials in acute respiratory distress syndrome

OBJECTIVE

To systematically review clinical trials in acute respiratory distress syndrome (ARDS).

DATA SOURCES

Computerized bibliographic search of published research and citation review of relevant articles.

STUDY SELECTION

All clinical trials of therapies for ARDS were reviewed. Therapies that have been compared in prospective, randomized trials were the focus of this analysis.

DATA EXTRACTION

Data on population, interventions, and outcomes were obtained by review. Studies were graded for quality of scientific evidence.

MAIN RESULTS

Lung protective ventilator strategy is supported by improved outcome in a single large, prospective trial and a second smaller trial. Other therapies for ARDS, including noninvasive positive pressure ventilation, inverse ratio ventilation, fluid restriction, inhaled nitric oxide, almitrine, prostacyclin, liquid ventilation, surfactant, and immune-modulating therapies, cannot be recommended at this time. Results of small trials using corticosteroids in late ARDS support the need for confirmatory large clinical trials.

CONCLUSIONS

Lung protective ventilator strategy is the first therapy found to improve outcome in ARDS. Trials of prone ventilation and fluid restriction in ARDS and corticosteroids in late ARDS support the need for large, prospective, randomized trials.

Pressure controlled Esmarch bandage used as a tourniquet

The objective of this paper is to investigate the manual wrapping techniques of Esmarch bandages used as tourniquets by physicians and to study the controllability of their induced pressure. The properties of the Esmarch bandage were first tested using two cylinders to allow uniform stretching of the bandage and to control the elastic exercusion and pressure reading. The pressure was measured using a load cell and a DPSI electronic strain/stress/pressure indicator device. The placement of the load cell sensor was found to yield constant values when measured along the lateral direction normal to the tension directional field of the cylinder. The results also show that the pressure increases at a rate 3 to 4 times the initial pressure when the bandage is stretched after each wrap rather than over the total length initially. The measurements over a plaster foot showed different pressure readings but exhibited a linear relationship in all three wraps performed. The method also shows a linear relationship between the elastic deformation and the number of wraps necessary to achieve a certain degree of mmHg.

Real-time two-dimensional imaging in scattering media by use of a femtosecond Cr(4+):forsterite laser

An original femtosecond Cr(4+):forsterite laser source associated with a nonlinear optical correlator was used for imaging through scattering media with 1220-nm light. The system, which operates as an ultrafast optical gate by sum-frequency generation in a nonlinear crystal, was able to detect the light reflected from a resolution chart hidden in a turbid medium, at an attenuation of as much as 15 mean free paths. When the object was illuminated with a collimated beam, real-time two-dimensional images were obtained, with a maximum transverse resolution of ~20 microm.

Expression of interleukin-18 in the lung after endotoxemia or hemorrhage-induced acute lung injury

Hemorrhage and endotoxemia are important risk factors for the development of acute lung injury. Interleukin (IL)-18 is a recently described cytokine released in its mature, active form after pro-IL-18 is cleaved by the IL-1 converting enzyme (ICE). IL-18 has multiple immunomodulating properties, including induction of interferon-gamma (IFN-gamma), IL-1beta, tumor necrosis factor-alpha, and intercellular adhesion molecule-1. To examine the possible involvement of IL-18 in acute lung injury, we examined its expression, as well as that of IFN-gamma, IL-12, and ICE, using murine hemorrhage or endotoxemia models. The amounts of IL-18 messenger RNA (mRNA) increased in the lung after hemorrhage or endotoxemia. However, only endotoxemia was associated with elevations in lung and plasma concentrations of IL-18 protein. ICE expression was increased in the lungs after endotoxemia but not after hemorrhage. Although IFN-gamma expression increased in the lungs after hemorrhage or endotoxemia, elevations in lung IL-12 mRNA levels were found only after endotoxemia. These results indicate that hemorrhage and endotoxemia induce different patterns of immunomodulatory cytokine expression in the lungs. In particular, differences in the expression of ICE after hemorrhage or endotoxemia may affect generation of the active forms of downstream cytokines, including IL-18. IFN-gamma expression in the lungs after hemorrhage appears to occur through a pathway independent of IL-12 and IL-18. IL-18 may play a role in modulating the development of acute lung injury after endotoxemia but not after hemorrhage.

Early renal ischemia, with or without reperfusion, activates NFkappaB and increases TNF-alpha bioactivity in the kidney

PURPOSE

Acute tubular necrosis (ATN) and the ensuing renal failure induced by ischemia and reperfusion injury (I/R) remain a major cause of morbidity and mortality among patients in the intensive care unit. Although it is well established that exogenous tumor necrosis factor-alpha (TNF) induces renal injury, it remains unknown whether ischemia and/or reperfusion activates the signaling mechanisms required for renal TNF production. We hypothesized that ischemia and/or reperfusion would activate the oxidant sensitive TNF transcription factor, nuclear factor kappa B (NFkappaB), and thereby lead to renal TNF production.

MATERIALS AND METHODS

Male Sprague-Dawley rats were anesthetized with sodium pentobarbital, after which various periods of renal ischemia, with or without reperfusion, were induced in rats. At different time intervals, kidneys were harvested and NFkappaB activation (electrophoretic mobility shift assay), TNF mRNA content (RT-PCR), and TNF bioactivity (WEHI-164 cell clone cytotoxicity assay) were determined.

RESULTS

Results indicate that 15 minutes of ischemia alone activates NFkappaB, whereas peak activation occurred at 30 minutes of ischemia alone. NFkappaB remained activated through 60 minutes reperfusion. Thirty minutes of ischemia is required to induce renal TNF mRNA production; however, renal TNF protein expression and bioactivity peaked following 1 hour of ischemia and 2 hours reperfusion.

CONCLUSIONS

These results are the initial demonstration that renal ischemia, with or without reperfusion, activates the TNF transcription factor NFkappaB and increases TNF bioactivity in the kidney.

GABAergic involvement in motor effects of an adenosine A(2A) receptor agonist in mice

Adenosine A(2A) agonists are known to induce catalepsy and inhibit dopamine mediated motor hyperactivity. An antagonistic interaction between adenosine A(2A) and dopamine D(2) receptors is known to regulate GABA-mediated neurotransmission in striatopallidal neurons. Stimulation of adenosine A(2A) and dopamine D(2) receptors has been shown to increase and inhibit GABA release respectively in pallidal GABAergic neurons. However, the role of GABAergic neurotransmission in the motor effects of adenosine A(2A) receptors is not yet known. Therefore in the present study the effect of GABAergic agents on adenosine A(2A) receptor agonist (NECA- or CGS 21680) induced catalepsy and inhibition of amphetamine elicited motor hyperactivity was examined. Pretreatment with GABA, the GABA(A) agonist muscimol or the GABA(B) agonist baclofen potentiated whereas the GABA(A) antagonist bicuculline attenuated NECA- or CGS 21680-induced catalepsy. However, the GABA(B) antagonists phaclophen and delta-aminovaleric acid had no effect. Administration of NECA or CGS 21680 not only reduced spontaneous locomotor activity but also antagonized amphetamine elicited motor hyperactivity. These effects of NECA and CGS 21680 were potentiated by GABA or muscimol and antagonized by bicuculline. These findings provide behavioral evidence for the role of GABA in the motor effects of adenosine A(2A) receptor agonists. Activation of adenosine A(2A) receptors increases GABA release which could reduce dopaminergic tone and induce catalepsy or inhibit amphetamine mediated motor hyperactivity.

Early renal ischemia, with or without reperfusion, activates NFkappaB and increases TNF-alpha bioactivity in the kidney

PURPOSE

Acute tubular necrosis (ATN) and the ensuing renal failure induced by ischemia and reperfusion injury (I/R) remain a major cause of morbidity and mortality among patients in the intensive care unit. Although it is well established that exogenous tumor necrosis factor-alpha (TNF) induces renal injury, it remains unknown whether ischemia and/or reperfusion activates the signaling mechanisms required for renal TNF production. We hypothesized that ischemia and/or reperfusion would activate the oxidant sensitive TNF transcription factor, nuclear factor kappa B (NFkappaB), and thereby lead to renal TNF production.

MATERIALS AND METHODS

Male Sprague-Dawley rats were anesthetized with sodium pentobarbital, after which various periods of renal ischemia, with or without reperfusion, were induced in rats. At different time intervals, kidneys were harvested and NFkappaB activation (electrophoretic mobility shift assay), TNF mRNA content (RT-PCR), and TNF bioactivity (WEHI-164 cell clone cytotoxicity assay) were determined.

RESULTS

Results indicate that 15 minutes of ischemia alone activates NFkappaB, whereas peak activation occurred at 30 minutes of ischemia alone. NFkappaB remained activated through 60 minutes reperfusion. Thirty minutes of ischemia is required to induce renal TNF mRNA production; however, renal TNF protein expression and bioactivity peaked following 1 hour of ischemia and 2 hours reperfusion.

CONCLUSIONS

These results are the initial demonstration that renal ischemia, with or without reperfusion, activates the TNF transcription factor NFkappaB and increases TNF bioactivity in the kidney.

NF-kappaB activation

Binding sites for the transcriptional regulatory factor nuclear factor kappa B (NF-kappaB) are present in the promoter regions of many of the proinflammatory cytokines and immunoregulatory mediators important in inducing acute inflammatory responses associated with critical illnesses. Because increased activation of NF-kappaB leads to enhanced expression of these proinflammatory mediators, NF-kappaB activation may be a central event in the development of multiple organ dysfunction associated with infection, blood loss, and ischemia-reperfusion injury. NF-kappaB is normally retained in the cytoplasm through its association with the inhibitory molecule I kappaB. Phosphorylation, ubiquination, and proteolysis of I kappaB allows NF-kappaB to translocate to the nucleus and induce transcription, once associated with the transcriptional cofactor CBP. The transcriptional activity of NF-kappaB can be regulated at multiple steps, including the amount of I kappaB present, NF-kappaB subunit composition, and competition for CBP binding. Because of the central role that NF-kappaB occupies in modulating immunoregulatory responses, further understanding of its regulation will be important in designing future therapies able to prevent or minimize acute inflammatory injury associated with critical illness.

NF-kappaB regulatory mechanisms in alveolar macrophages from patients with acute respiratory distress syndrome

Activation of the nuclear regulatory factor NF-kappaB occurs in the lungs of patients with the acute respiratory distress syndrome (ARDS) and may contribute to the increased expression of immunoregulatory cytokines and other proinflammatory mediators in this setting. Because of the important role that NF-kappaB activation appears to play in the development of acute lung injury, we examined cytoplasmic and nuclear NF-kapppaB counterregulatory mechanisms, involving IkappaB proteins, in alveolar macrophages obtained from 7 control patients without lung injury and 11 patients with established ARDS. Cytoplasmic levels of the NF-kappaB subunits p50, p65, and c-Rel were significantly decreased in alveolar macrophages from patients with ARDS, consistent with enhanced migration of liberated NF-kappaB dimers from the cytoplasm to the nucleus. Cytoplasmic and nuclear levels of IkappaBalpha were not significantly altered in alveolar macrophages from patients with established ARDS, compared with controls. In contrast, nuclear levels of Bcl-3 were significantly decreased in patients with ARDS compared with controls (P = 0.02). No IkappaBgamma, IkappaBbeta, or p105 proteins were detected in the cytoplasm of alveolar macrophages from control patients or patients with ARDS. The presence of activated NF-kappaB in alveolar macrophages from patients with established ARDS implies the presence of an ongoing stimulus for NF-kappaB activation. In this setting, appropriate counterregulatory mechanisms to normalize nuclear levels of NF-kappaB and to suppress NF-kappaB-mediated transcription, such as increased cytoplasmic and nuclear IkappaBalpha levels or decreased Bcl-3 levels, appeared to be induced. Nevertheless, even though counterregulatory mechanisms to NF-kappaB activation are activated in lung macrophages of patients with ARDS, NF-kappaB remains activated. These results suggest that fundamental abnormalities in transcriptional mechanisms involving NF-kappaB and important in the inflammatory response occur in the lungs of patients with ARDS.

Early findings from a community-based, cluster-randomized, controlled oral cancer screening trial in Kerala, India. The Trivandrum Oral Cancer Screening Study Group

BACKGROUND

Oral cancer satisfies the criteria for a suitable disease for screening, and oral visual inspection is a suitable test for oral cancer screening. The efficacy of screening in reducing mortality from oral cancer has not yet been evaluated. The authors describe a cluster-randomized, controlled oral cancer screening trial in southern India and its early results.

METHODS

Apparently healthy subjects age 35 years or older in 13 clusters called panchayaths were randomized to either an intervention group (n = 7) or a control group (n = 6). Subjects in the intervention group will receive 3 rounds of screening consisting of oral visual inspection by trained health workers at 3-year intervals. The first round of screening was carried out between October 1995 and May 1998. Participants were visited in their homes and interviewed for sociodemographic details, tobacco-smoking and alcohol-drinking habits, and personal medical history. Those with tobacco or alcohol habits were advised to stop those habits. Subjects in the intervention group were offered screening, and those with lesions suggestive of oral leukoplakia, submucous fibrosis, or oral cancer were referred for examination by physicians. Confirmed leukoplakias were excised whenever possible, others were kept on follow-up, and those with confirmed oral cancers were referred for treatment. Data on oral cancer incidence, stage distribution, survival, and mortality in the study groups are obtained by record linkage with the Trivandrum population-based cancer registry and municipal death registration systems.

RESULTS

There were 59,894 eligible subjects in the intervention group and 54,707 in the control group; 31.4% of the former group reported no tobacco or alcohol habits, compared with 44.1% of the latter. The distribution of age, education, occupation, income, and socioeconomic status were similar in the two groups. Of 3585 subjects in the intervention group referred, 52.4% were examined by physicians; 36 subjects with oral cancers and 1310 with oral precancers were diagnosed. Of the 63 oral cancers recorded in the cancer registry, 47 were in the intervention group and 16 were in the control group, yielding incidence rates of 56.1 and 20.3 per 100,000 person-years in the intervention and control groups, respectively. The program sensitivity for detection of oral cancer was 76.6% and the specificity 76.2%; the positive predictive value was 1.0% for oral cancer. In the intervention group, 72.3% of the cases were in Stages I-II, as opposed to 12.5% in the control group. The 3-year case fatality rates were 14.9% (7 of 47 patients) in the intervention group and 56.3% (9 of 16 patients) in the control group.

CONCLUSIONS

Though compliance with referral for confirmatory examination in the first round was lower than the 70% anticipated, intermediate end points, such as stage at diagnosis and case fatality, indicate that the trial is making fairly satisfactory progress.

Consensus conference definitions for sepsis, septic shock, acute lung injury, and acute respiratory distress syndrome: time for a reevaluation

Definitions for sepsis, septic shock, acute lung injury (ALI), and acute respiratory distress syndrome (ARDS) were developed by consensus conferences with the goal of achieving standardization of terminology and improved homogeneity of patient populations in clinical studies. Although such definitions have been useful in epidemiologic investigations, the criteria specified by the consensus conferences are broad and insufficiently specific to address the problem of heterogeneous mechanisms leading to clinical syndromes. An important challenge is to progress from clinical syndromes, as presently defined, to more specific entities that are delineated by alterations in specific immunologic or biochemical pathways. Such mechanistic definitions will provide more homogeneous groups of patients who can be identified at early stages of their clinical course. This approach encourages focused investigation of pathways leading to organ system dysfunction and death and, also, provides an efficient framework for the development of new therapies useful in critically ill patients.

Germline transformation of the silkworm Bombyx mori L. using a piggyBac transposon-derived vector

We have developed a system for stable germline transformation in the silkworm Bombyx mori L. using piggyBac, a transposon discovered in the lepidopteran Trichoplusia ni. The transformation constructs consist of the piggyBac inverted terminal repeats flanking a fusion of the B. mori cytoplasmic actin gene BmA3 promoter and the green fluorescent protein (GFP). A nonautonomous helper plasmid encodes the piggyBac transposase. The reporter gene construct was coinjected into preblastoderm eggs of two strains of B. mori. Approximately 2% of the individuals in the G1 broods expressed GFP. DNA analyses of GFP-positive G1 silkworms revealed that multiple independent insertions occurred frequently. The transgene was stably transferred to the next generation through normal Mendelian inheritance. The presence of the inverted terminal repeats of piggyBac and the characteristic TTAA sequence at the borders of all the analyzed inserts confirmed that transformation resulted from precise transposition events. This efficient method of stable gene transfer in a lepidopteran insect opens the way for promising basic research and biotechnological applications.