Sandra M. Schneider

The deadenylating nuclease (DAN) is involved in poly(A) tail removal during the meiotic maturation of Xenopus oocytes

Exonucleolytic degradation of the poly(A) tail is often the first step in the decay of eukaryotic mRNAs and is also used to silence certain maternal mRNAs translationally during oocyte maturation and early embryonic development. We previously described the purification of a poly(A)‐specific 3′‐exoribonuclease (deadenylating nuclease, DAN) from mammalian tissue. Here, the isolation and functional characterization of cDNA clones encoding human DAN is reported. Recombinant DAN overexpressed in Escherichia coli has properties similar to those of the authentic protein. The amino acid sequence of DAN shows homology to the RNase D family of 3′‐exonucleases. DAN appears to be localized in both the nucleus and the cytoplasm. It is not stably associated with polysomes or ribosomal subunits. Xenopus oocytes contain nuclear and cytoplasmic DAN isoforms, both of which are closely related to the human DAN. Anti‐DAN antibody microinjected into oocytes inhibits default deadenylation during progesterone‐induced maturation. Ectopic expression of human DAN in enucleated oocytes rescues maturation‐specific deadenylation, indicating that amphibian and mammalian DANs are functionally equivalent.

JNK phosphorylation relieves HDAC3‐dependent suppression of the transcriptional activity of c‐Jun

The AP‐1 transcription factor c‐Jun is a prototypical nuclear effector of the JNK signal transduction pathway. The integrity of JNK phosphorylation sites at serines 63/73 and at threonines 91/93 in c‐Jun is essential for signal‐dependent target gene activation. We show that c‐Jun phosphorylation mediates dissociation of an inhibitory complex, which is associated with histone deacetylase 3 (HDAC3). The subsequent events that ultimately cause increased mRNA synthesis are independent of c‐Jun phosphorylation and its interaction with JNK. These findings provide an ‘activation by de‐repression’ model as an explanation for the stimulatory function of JNK on c‐Jun.

TCDD induces c-jun expression via a novel Ah (dioxin) receptor-mediated p38-MAPK-dependent pathway

The aryl hydrocarbon receptor (AhR) has a fundamental role during postnatal liver development and is essential for mediating dioxin toxicity. However, the genetic programs mediating, both, the toxic and physiological effects downstream of the transcription factor AhR are in major parts unknown. We have identified the proto-oncogene c-jun as a novel target gene of AhR. Induction of c-jun depends on activation of p38–mitogen-activated protein kinase (MAPK) by an AhR-dependent mechanism. None of the kinases that are known to phosphorylate p38-MAPK is activated by AhR. Neither the dephosphorylation rate of p38–MAPK is reduced. Furthermore, increased p38–MAPK phosphorylation in response to dioxins does not require ongoing transcription. These findings establish activating ‘cross-talk’ with MAPK signaling as a novel principle of AhR action, which is apparently independent of the AhRs function as a DNA-binding transcriptional activator.

DNA damage induces downregulation of histone gene expression through the G1 checkpoint pathway

Activation of the G1 checkpoint following DNA damage leads to inhibition of cyclin E–Cdk2 and subsequent G1 arrest in higher eucaryotes. Little, however, is known about the molecular events downstream of cyclin E–Cdk2 inhibition. Here we show that, in addition to the inhibition of DNA synthesis, ionizing radiation induces downregulation of histone mRNA levels in mammalian cells. This downregulation occurs at the level of transcription and requires functional p53 and p21CIP1/WAF1 proteins. We demonstrate that DNA damage induced by ionizing radiation results in the suppression of phosphorylation of NPAT, an in vivo substrate of cyclin E–Cdk2 kinase and an essential regulator of histone gene transcription, and its dissociation from histone gene clusters in a p53/p21‐dependent manner. Inhibition of Cdk2 activity by specific inhibitors in the absence of DNA damage similarly disperses NPAT from histone gene clusters and represses histone gene expression. Our results thus suggest that inhibition of Cdk2 activity following DNA damage results in the downregulation of histone gene transcription through dissociation of NPAT from histone gene clusters.

Teaching Emergency Medicine Residents Evidence-Based Critical Appraisal Skills: A Controlled Trial

STUDY OBJECTIVES To compare the performance of an evidence-based medicine (EBM) approach and a traditional approach to teaching critical appraisal skills to emergency medicine residents. METHODS This was a prospective, case-controlled trial of 32 emergency medicine residents (16 control and 16 intervention). Intervention residents were exposed to a monthly, 1-hour journal club using an EBM approach to critical appraisal over the course of 1 year. Control residents were exposed to a traditional, unstructured journal club, also monthly. Both groups were given a factitious article to evaluate in an essay format before and after the 12-month study period. The Wilcoxon rank sum test was used to compare mean improvement in test scores for each group. RESULTS The mean improvement in test scores was 1.80 for the control group and 1.53 for the intervention group; these values were not significantly different (P =.90). The difference in mean change in test score between the 2 groups was.27 points. CONCLUSION Compared with a traditional approach, an EBM approach to teaching critical appraisal did not appear to improve the critical appraisal skills of emergency medicine residents. However, because of the small number of subjects studied, small differences in critical appraisal skill improvement cannot be ruled out.

Medical and nursing staff highly value clinical pharmacists in the emergency department

Despite the potential impact that emergency pharmacist (EPh) programmes could have on medication safety and quality of care in the emergency department (ED), very few programmes exist. This descriptive survey study aimed to assess staff perceptions of an EPh programme. A random sample of medical and nursing staff in an academic medical centre ED with a dedicated EPh programme received a 26-item survey (82% return rate). 99% of respondents felt the EPh improves quality of care, 96% feel they are an integral part of the team, and 93% had consulted the EPh at least a few times during their last five shifts. Staff felt that the EPh should be available for consults, attend resuscitations, and check orders. This study reinforced the value of many specific duties of the EPh programme and found that doctors and nurses overwhelmingly favour the presence of an EPh in the ED, frequently seek their advice, and feel they improve quality of care. Staff acceptance is clearly not a barrier to implementation of this programme.

High-dose methylprednisolone as initial therapy in patients with acute bronchospasm

The use of steroids in treating acute respiratory obstruction is still controversial. In this double-blind controlled trial, we decided to examine the beneficial effects of a single large dose of methylprednisolone (MSSP), using objective criteria. In the emergency setting, methylprednisolone (30 mg/kg) has been shown to decrease the need for hospital admission in patients with acute bronchospasm. No difference in this improvement was seen among patients in the steroid-dependent or non-steroid-dependent populations. Based on our findings, we suggest that the early use of single-dose steroid therapy is appropriate treatment for patients with acute bronchospastic attacks.

A study of the workforce in emergency medicine: 2007

INTRODUCTION This study was undertaken to describe the current status of the emergency medicine workforce in the United States. METHODS Surveys were distributed in 2008 to 2619 emergency department (ED) medical directors and nurse managers in hospitals in the 2006 American Hospital Association database. RESULTS Among ED medical directors, 713 responded, for a 27.2% response rate. Currently, 65% of practicing emergency physicians are board certified by the American Board of Emergency Medicine or the American Osteopathic Board of Emergency Medicine. Among those leaving the practice, the most common reasons cited for departure include geographic relocation (46%) and better pay (29%). Approximately 12% of the ED physician workforce is expected to retire in the next 5 years. Among nurse managers, 548 responded, for a 21% response rate. Many nurses (46%) have an associate degree as their highest level of education, 28% have a BSN, and 3% have a graduate degree (MSN or higher). Geographic relocation (44%) is the leading reason for changing employment. Emergency department annual volumes have increased by 49% since 1997, with a mean ED volume of 32 281 in 2007. The average reported ED length of stay is 158 minutes from registration to discharge and 208 minutes from registration to admission. Emergency department spent an average of 49 hours per month in ambulance diversion in 2007. Boarding is common practice, with an average of 318 hours of patient boarding per month. CONCLUSIONS In the past 10 years, the number of practicing emergency physicians has grown to more than 42 000. The number of board-certified emergency physicians has increased. The number of annual ED visits has risen significantly.

A Consensus Parameter for the Evaluation and Management of Angioedema in the Emergency Department

Despite its relatively common occurrence and life-threatening potential, the management of angioedema in the emergency department (ED) is lacking in terms of a structured approach. It is paramount to distinguish the different etiologies of angioedema from one another and more specifically differentiate histaminergic-mediated angioedema from bradykinin-mediated angioedema, especially in lieu of the more novel treatments that have recently become available for bradykinin-mediated angioedema. With this background in mind, this consensus parameter for the evaluation and management of angioedema attempts to provide a working framework for emergency physicians (EPs) in approaching the patient with angioedema in terms of diagnosis and management in the ED. This consensus parameter was developed from a collaborative effort among a group of EPs and leading allergists with expertise in angioedema. After rigorous debate, review of the literature, and expert opinion, the following consensus guideline document was created. The document has been endorsed by the American College of Allergy, Asthma & Immunology (ACAAI) and the Society for Academic Emergency Medicine (SAEM).

Critical cardiac transport: Air versus ground?

The helicopter transport of acute cardiac patients has become increasingly common, although no study has examined solely the effect of such transport on outcome in this subset of patients. A combined air and ground critical care transport service provided the opportunity for a direct comparison of patients with acute cardiac conditions (myocardial infarction or unstable angina) transported either by our helicopter or by a specially equipped critical care ground vehicle. Both air and ground components were similarly equipped in terms of personnel and medical equipment. Seventy-eight (27 ground, 51 air) transport cases were studied. Both patient groups were comparable in terms of age, sex, Killip classification, and diagnosis. Serious untoward events, defined as arrhythmias, chest pain, hypotension, bradycardia, seizures, and cardiac arrest, occurred in 41% of air transports and 7.5% of ground transports (P less than .002). The overall incidence of untoward events was also significantly greater with air transports (25/51, or 49%) than with the ground vehicle (4/27, or 15%; P less than .005). The reasons for these differences are unknown.