Effect of simulated patient death on emergency worker's anxiety: a cluster randomized trial.

OBJECTIVE: Simulation-based teaching offers promising and diverse teaching possibilities. We aim to assess whether the death of the manikin increased anxiety amongst learner compared to similar simulation-based course where the manikin stays alive. METHODS: We conducted a cluster randomized study amongst multidisciplinary teams of emergency workers. Teams of physicians, nurses, and healthcare assistants were randomly assigned to participate in a simulation-based course where the simulated patient died (death group) or not (life group). We assessed anxiety at 1 month after the teaching using Spielberger STAI-state anxiety questionnaire. We compared reduction of anxiety when facing a life-threatening situation in both groups. RESULTS: We included 25 teams for a total of 129 participants. We analysed 63 participants in the death group and 57 in the life group. Baseline characteristics were similar in both groups, including baseline anxiety (STAI-state score 39.6 (7.8) in the death group vs 38.6 (7.1) in the life group). We report a significant reduction in both groups 1 month after the training: 6.6 (7.8) vs 6 (8.0), mean difference 0.5 (-2.4; 3.4). At 3 months, we report a significant greater reduction of anxiety in the death group (mean difference 4 [0.1; 7.9]). CONCLUSION: We observed in our sample that unexpected simulated patient death did not increase anxiety amongst multidisciplinary emergency workers.

[Autoimmune hepatitis triggered by nitrofurantoin: A rare drug-induced toxicity]. / Hépatite auto-immune induite par la nitrofurantoïne : une complication rare à connaître.

INTRODUCTION: Nitrofurantoin is a commonly used drug which can have liver and pulmonary adverse effects. Among hepatic nitrofurantoin-induced adverse effects, autoimmune hepatitis is a rare complication which must not be mistaken as a toxic hepatitis. CASE REPORT: We report an 86-year-old woman who presented with acute hepatitis after a 3-month course of nitrofurantoin administration for urinary tract infections. She reported a previous hepatitis after treatment by nitrofurantoin twenty years before. Biological analysis showed polyclonal hypergammaglobulinemia, positive test for antinuclear antibodies and smooth muscle antibodies. Finally, liver histology showed lymphocytic infiltration, marked necrotic and inflammatory activity consistent with the diagnosis of autoimmune hepatitis. Nitrofurantoin was discontinued. Outcome of autoimmune hepatitis was good with corticosteroids and azathioprine but two months later, the patient died from a refractory global heart failure. CONCLUSION: Nitrofurantoin-induced autoimmune hepatitis is a severe condition which must be systematically discussed in patients taking nitrofurantoin who present with acute hepatitis. Hypergammaglobulinemia is an easily obtained blood marker, which can suggest this diagnosis. Treatment relies on nitrofurantoin eviction, corticosteroids and sometimes azathioprine. Outcome is usually favorable.

The agreement between abnormal venous lactate and arterial lactate in the ED: a retrospective chart review.

INTRODUCTION: The evidence for prognostication using lactate is often based on arterial lactate (AL). Arterial sampling is painful and difficult, and carries risks. Studies comparing peripheral venous lactate (PVL) with AL showed little difference but predominantly included patients with normal lactate. The objective of this study was to measure agreement between PVL and AL in patients with elevated venous lactate. METHODS: This is a retrospective cross-sectional study. INCLUSION CRITERIA: ED patients age≥16, attending from October 2010 to June 2011 inclusive, with PVL≥2.0 mmol/L and AL taken within 1 hour. EXCLUSION CRITERIA: intravenous fluid prior to or between initial venous and arterial sampling. Primary endpoint: agreement between PVL and AL defined as mean difference±95% limits of agreement (LOA). The misclassification rate was assessed. RESULTS: N=232. VL median 3.50 mmol/L, range 2.00 to 15.00 mmol/L. AL median 2.45 mmol/L, range 1.0 to 13.2 mmol/L. The mean difference±SD between PVL and AL for all patients was 1.06±1.30 mmol/L (95%LOA -1.53 to 3.66 mmol/L). Using a cut-off of 2 mmol/L and 4 mmol/L, 36.2% and 17.9% of patients respectively were incorrectly classified as having elevated lactate. CONCLUSION: We report greater bias between VL and AL with broader LOA than previously documented. This may partly be due to the fact that we studied only patients with abnormal venous values, for whom close agreement would confer greatest clinical significance. The agreement between abnormal PVL and AL is poor and the high rate of misclassification may suggest that PVL is not a good substitute for AL if the venous lactate is abnormal.

Pulmonary Embolism Rule-out Criteria vs D-dimer testing in low-risk patients for pulmonary embolism: a retrospective study.

STUDY OBJECTIVES: The Pulmonary Embolism Rule-out Criteria (PERC) score has shown excellent negative predictive value; however, its use in the European population with high prevalence of PE is controversial. In Europe, PERC is not part of routine practice. For low-risk patients, guidelines recommend D-dimer testing, followed if positive by imaging study. We aimed to study the rate of diagnosis of PE after D-dimer testing in PERC-negative patients that could have been discharged if PERC was applied. METHOD: This was a multicenter retrospective study in Paris, France. We included all patients with a suspicion of PE who had D-dimer testing in the emergency department, low pre-test probability, and a negative PERC score (that was retrospectively calculated). Patients with insufficient record to calculate PERC score were excluded. The primary end point was the rate of PE diagnosis before discharge in this population. Secondary end points included rate of invasive imaging studies and subsequent adverse events. RESULTS: We screened 4301 patients who had D-dimer testing, 1070 of whom were PERC negative and could be analyzed. The mean age was 35 years and 46% were men. D-dimer was positive (>500 ng/L) in 167 (16%) of them; CTPA or V/Q scan was performed in 153 (14%) cases. PE was confirmed in 5 cases (total rate 0.5%, 95% confidence interval 0.1%-1.1%). Fifteen patients (1%) experienced non-severe adverse events. CONCLUSION: D-dimer testing in PERC-negative patients led to a diagnosis of PE in 0.5% of them, with 15% of patients undergoing unnecessary irradiative imaging studies.

Immunohematotoxicity studies with combinations of dapsone and zidovudine.

We investigated the immunohematoxicities of the antiparasitic drug dapsone (DDS) and the antiretroviral drug zidovudine (ZDV, AZT) given alone or in combination in BALB/c mice. DDS is used for prophylaxis and treatment of Pneumocystis carinii infection in AIDS patients. We examined the impact of concurrent administration of these drugs on the immune and hematopoietic systems because DDS causes hematotoxicity and ZDV therapy results in bone marrow toxicity. Daily oral administration of DDS at 25 and 50 mg/kg for 28 days caused a slight anemia, marked methemoglobinemia, reticulocytosis, and a moderate leukopenia (P < 0.01 for all parameters) but had no discernible effect on platelet count. In DDS-treated mice, the proliferative response of splenic T cells to concanavalin A was > or = 35% higher than that manifested by splenocytes from vehicle-treated control mice. ZDV at 240 and 480 mg/kg was not immunosuppressive but caused low-grade macrocytic anemia, thrombocytosis, and neutropenia; these effects were drug dose-dependent and statistically significant (P < 0.01). Concurrent administration of DDS and ZDV augmented the severity of ZDV-mediated macrocytic anemia, and 7 of 12 (58%) mice did not survive treatment with the high doses of DDS and ZDV (50 and 480 mg/kg, respectively). On the other hand, co-administration of ZDV mitigated DDS-induced methemoglobinemia and the DDS-associated elevation in lymphoproliferative response. These data suggest interaction between DDS and ZDV in mice and indicate a need for caution in using DDS as long-term therapy in AIDS patients receiving ZDV.

In vitro investigation of host resistance to Toxoplasma gondii infection in microglia of BALB/c and CBA/Ca mice.

Toxoplasmic encephalitis (TE) is a life-threatening disease of immunocompromised individuals and has increased in prevalence as a consequence of AIDS. TE has been modeled in inbred mice, with CBA/Ca mice being susceptible and BALB/c mice resistant to the development of TE. To better understand the innate mechanisms in the brain that play a role in resistance to TE, nitric oxide (NO)-dependent and NO-independent mechanisms were examined in microglia from BALB/c and CBA/Ca mice and correlated with the ability of these cells to inhibit Toxoplasma gondii replication. These parameters were measured 48 h after stimulation with lipopolysaccharide (LPS) gamma interferon (IFN-gamma), tumor necrosis factor alpha (TNF-alpha), or combinations of these inducers in T. gondii-infected microglia isolated from newborn mice. CBA/Ca microglia consistently produced less NO than did BALB/c microglia after stimulation with LPS or with IFN-gamma plus TNF-alpha, and they inhibited T. gondii replication significantly less than did BALB/c microglia. Cells of both strains treated with IFN-gamma alone significantly inhibited uracil incorporation by T. gondii, and N(G)-monomethyl-L-arginine (NMMA) treatment did not reverse this effect. In cells treated with IFN-gamma in combination with other inducers, NMMA treatment resulted in only partial recovery of T. gondii replication. This IFN-gamma-dependent inhibition of replication was not due to generation of reactive oxygen species or to increased tryptophan degradation. These data suggest that NO production and an IFN-gamma-dependent mechanism contribute to the inhibition of T. gondii replication after in vitro stimulation with IFN-gamma plus TNF-alpha or with LPS. Differences in NO production but not in IFN-gamma-dependent inhibition of T. gondii replication were observed between CBA/Ca and BALB/c microglia.

Oral treatment with trimethoprim-sulfamethoxazole and zidovudine suppresses murine accessory cell-dependent immune responses.

Trimethoprim-sulfamethoxazole (TMP-SMX), commonly used for prophylaxis of Pneumocystis carinii pneumonia (PCP) in AIDS patients, often produces a high incidence of treatment-limiting reactions. We investigated the effect of oral administration of TMP-SMX alone or in combination with the antiretroviral drug zidovudine (ZDV) on hematopoiesis and cellular immunity in BALB/c mice. Daily treatment for 28 days with TMP-SMX (160:800 mg/kg) had no effect on hematopoiesis or the ex vivo proliferative response of splenic T lymphocytes to allogeneic tumor cells (EL-4) or to concanavalin A (ConA), or that of splenic B cells to lipopolysaccharide (LPS). ZDV at 240 mg/kg/day was not immunosuppressive but caused a mild macrocytic anemia. Combined treatment produced severe pancytopenia, a significant drop in splenic cellularity, and a 61% decrease in the percentage of splenic macrophages. The percentage of splenic CD3+ lymphocytes increased 150% in the TMP-SMX + ZDV group, but the ratios of T-cell subsets and the frequency of B cells remained unchanged. Combined drug treatment did not impair the proliferative response of B cells to LPS or that of T cells to EL-4 cells. In concert with the reduction in the percentage of macrophages, the proliferative response of T lymphocytes to ConA decreased significantly. Optimal ConA-induced T-cell proliferation requires the participation of accessory cells (AC) (e.g., macrophages); EL-4 cells are able to function as AC. These data indicate that ZDV synergizes with TMP-SMX, causing severe hematotoxicity and suppressing AC-dependent immune function, and suggest that this therapeutic regimen may contribute to the immune deterioration in AIDS patients.

Vaccination with a recombinant vaccinia vaccine containing the B7-1 co-stimulatory molecule causes no significant toxicity and enhances T cell-mediated cytotoxicity.

B7-1 is a co-stimulatory molecule that provides a second signal for T-cell activation. Several studies have demonstrated that vaccination with a vector containing genes encoding B7-1 and an antigen appears to be efficacious at promoting immune responsiveness to the antigen. To evaluate the safety of such a protocol and determine the effect of the B7-1 vector on immune responsiveness, female C57BL/6 mice were administered Wyeth wild-type vaccinia virus (V-WT) or V-WT containing the gene for B7-1 (rV-B7-1) as a single s. c. injection or 3 monthly s.c. injections. Immunologic parameters were evaluated in half of the mice and general toxicity in the other half. Immunologic end points included determination of splenic lymphocyte phenotypes, mitogen-induced T- and B-cell proliferation, T-cell proliferation in response to alloantigens, cell-mediated cytotoxicity (CMC), natural killer cell activity and serum anti-nuclear antibody (ANA) titers. No significant signs of general toxicity were noted. The primary immunologic effect was an increase in the ability of spleen cells to lyse allogeneic targets and to proliferate in response to allogeneic stimulation. Numbers of splenic CD8(+) cells were also increased. These effects were more pronounced after 3 vaccinations than after a single vaccination. Minimal differences in ANA were observed between mice immunized with V-WT and rV-B7-1. In addition, no serum antibodies against B7-1 were detected in any mice. The data suggest that vaccination with rV-B7-1 augments CMC with minimal toxicity.

Pyrimethamine impairs host resistance to infection with Listeria monocytogenes in BALB/c mice.

Increased mortality has been observed when HIV-infected patients were treated with pyrimethamine (Pyr) as prophylaxis for toxoplasmic encephalitis, suggesting that Pyr might possess immunosuppressive activity. To analyze this in an animal model, immune function was assessed in BALB/c mice using a battery of in vivo and ex vivo assays and an in vivo model of host resistance to Listeria monocytogenes infection. Treatment for 30 days with 60 mg/kg Pyr decreased circulating white blood cell and lymphocyte counts but not neutrophil, red blood cell, or platelet counts or hemoglobin levels. Splenic B cell percentages and lipopolysaccharide-induced B cell proliferation decreased significantly after treatment with 60 mg/kg Pyr, as did levels of anti-keyhole limpet hemocyanin (KLH) IgM in serum 7 days after immunization with KLH. Anti-KLH IgG levels 14 days after immunization were not affected. Percentages of splenic T cells and macrophages and T cell proliferation in the presence of concanavalin A or allogeneic cells were not decreased by Pyr treatment. An ex vivo assay of T-cell-mediated cytotoxicity was also unaffected. When host resistance to L. monocytogenes infection was assessed, dramatic increases in mortality were observed in Pyr-treated compared to control mice. Increased numbers of L. monocytogenes organisms were observed in liver and spleen of Pyr-treated mice, compared to controls. The reduction in Listeria resistance, which is T cell mediated, contrasts with the fact that no significant changes in T-cell-mediated immunity were observed. It is possible that Pyr affects parameters of innate immunity, which were not monitored in this study.

TNF-alpha differentially regulates Ia antigen expression and macrophage tumoricidal activity in two murine macrophage cell lines.

We have assessed tumor necrosis factor-alpha (TNF-alpha) production and its autocrine effects on activation in two murine macrophage cell lines which have distinct responses to the activation stimuli interferon-gamma (IFN-gamma) and bacterial lipopolysaccharide (LPS), and compared these responses to those observed in thioglycollate-elicited peritoneal macrophages. IFN-gamma induced TNF-alpha production in RAW 264.7 cells and this induction was regulated at the transcriptional level. IFN-gamma did not stimulate TNF-alpha production in either WEHI-3 cells or peritoneal macrophages, although MHC class II antigen expression was induced. LPS stimulated TNF-alpha production in the RAW 264.7 cell line and peritoneal macrophages; however, no TNF-alpha was detected in WEHI-3 cells activated with LPS. We also assessed the ability of endogenous TNF-alpha to serve as an autocrine regulator of two aspects of IFN-gamma-mediated macrophage activation, namely, induction of antibody-independent tumoricidal activity and induction of MHC class II antigen expression. These studies revealed that TNF-alpha could act synergistically or antagonistically with IFN-gamma in the regulation of these two functions, depending on both the macrophage population used and the function assessed. The results of our experiments suggest that the mechanism of induction of TNF-alpha production by IFN-gamma or LPS, and the ultimate autocrine contribution of such TNF-alpha to a given activation response, is dependent on the activated macrophage target population under analysis. The WEHI-3 and RAW 264.7 cell lines provide a model system for comparative exploration of the mechanistic basis of this differential regulation.

Polymorphisms in the tumor necrosis factor alpha (TNF-alpha) gene correlate with murine resistance to development of toxoplasmic encephalitis and with levels of TNF-alpha mRNA in infected brain tissue.

Murine resistance to development of toxoplasmic encephalitis (TE) has recently been mapped to the D region of the major histocompatibility complex (H-2). Since the gene for tumor necrosis factor alpha (TNF-alpha) is located 5' of the D region and TNF-alpha has been implicated as playing a role in neurological diseases, we were interested in determining the relationship of TNF-alpha production to TE resistance. We have demonstrated that resistance to TE in inbred mice can be correlated with specific restriction fragment length polymorphisms and microsatellite variants in the TNF-alpha gene. Mice that are susceptible to TE express elevated levels of TNF-alpha mRNA in brain tissue 6 wk after infection with the ME49 strain of Toxoplasma gondii. Resistant mice and all mice that are uninfected show no detectable TNF-alpha mRNA expression in brain tissue. Differences in the TNF-alpha gene between susceptible and resistant mice have been localized to the first intron, the promoter, and the 3' end of the TNF-alpha gene. These data implicate differences in regulation of TNF-alpha production in brain tissue as contributing to differences in susceptibility to development of TE.

cis-acting sequences required for class II gene regulation by interferon gamma and tumor necrosis factor alpha in a murine macrophage cell line.

In this report, we have demonstrated that IFN-gamma and TNF-alpha increase expression of both the I-A and I-E region gene products on the surface of the myelomonocytic cell line WEHI-3, and that they mediate this increase via an increase in A alpha transcription. Constructs containing 5' deletion mutations of the A alpha promoter attached to the bacterial chloramphenicol acetyl transferase gene were used to delineate the minimum 5' flanking sequences required for promoter activity, and for inducibility by IFN-gamma and TNF-alpha. Approximately 115 bp of 5' sequences are required for minimum induction by IFN-gamma or TNF-alpha when the cytokines are present separately. This includes the three conserved promoter elements, the X, Y, and H boxes. Nested linker-scanner mutations demonstrated that additional regions were also critical for optimal induction by IFN-gamma or TNF-alpha. These include the kappa B-like enhancer and a TNF-alpha-specific sequence that we have tentatively called the T box. The T box sequence was also found in the promoter regions of the human HLA-DQ alpha and rat RT1.B alpha genes. Although the entire T box sequence element was not found in the other mouse class II genes, all class II alpha genes contained the SV40 core enhancer element in the regions included by the T box. Mouse class II beta genes appear to contain neither the T box nor the core enhancer element in this region, suggesting differential regulation of class II alpha and beta genes by TNF-alpha.

Reduced blood flow in the transverse sinus visualized by ultra low field magnetic resonance imaging.

With an ultra low field magnetic resonance imager (ULF-MRI) operating at 0.02 Tesla we describe a case of increased signal intensity from the transverse and sigmoid sinuses of the brain. A comparison with radionuclide angiography and skull computer tomography is made. The difficulties in differentiating low blood flow and venous thrombosis is also discussed.

Coordinate induction of Ia alpha, beta, and Ii mRNA in a macrophage cell line.

We demonstrated a tightly coordinated timing in the appearance of mRNA for the four class II (Ia) MHC chains, A alpha, A beta, E alpha, and E beta, and the Ia-associated invariant chain in a murine macrophage cell line after the addition of immune interferon (IFN-gamma) or of IFN-gamma-containing supernatants from Con A-stimulated spleen cells. The marked increase in mRNA levels for these molecules at approximately 8 hr after IFN-gamma addition contrasts sharply with the earlier, more gradual kinetics observed for class I (H-2) and beta 2-microglobulin mRNA. The difference in kinetics of IFN-gamma induction of class I and class II mRNA suggests differential regulation of the expression of Ia and H-2 antigens. The long lag period preceding detection of Ia mRNA raises the possibility that IFN-gamma may not directly mediate the increase in mRNA expression, but may act through an additional cellular intermediate.

Depression of natural killer activity and mitogen responsiveness in mice treated with pristane.

In BALB/c mice, the injection of pristane resulted in a severe decrease in splenic T and B cell proliferative responses to mitogens and in a depression of natural killer (NK) activity. The effects of T and B cells, which persisted for at least 5 mo, were mediated by different mechanisms. T cell responsiveness to PHA dropped significantly below control levels 1 wk after the first of three monthly pristane injections, whereas B cell proliferation in response to LPS did not decrease until 4 wk after the first injection. The removal of plastic-adherent suppressor cells completely restored T cell proliferative capacity, but had no effect on B cells. NK activity against YAC-1 tumor targets was reduced 1 mo after the first pristane injection and remained depressed for at least 3 mo. This depression was not mediated by plastic-adherent suppressor cells. Spleen cell NK activity from pristane-treated mice could not be augmented by the interferon inducer Poly I:C to the same extent as that of control mice. This suggests an effect of pristane on either pre-NK cells or on cells that regulate NK activity.