Impact of an antimicrobial stewardship programme to optimize antimicrobial use for outpatients at an emergency department.

BACKGROUND: Antimicrobial stewardship programmes (ASPs) have been effective in optimizing antibiotic use for inpatients. However, an emergency department's fast-paced clinical setting can be challenging for a successful ASP. AIM: In April 2015, an ASP was implemented in our emergency department and we aimed to determine its impact on antimicrobial use for outpatients. METHODS: This was a single-centre study comparing the quality of antibiotic prescriptions between a one-year period before ASP implementation (November 2012 to October 2013) and a one-year period after its implementation (June 2015 to May 2016). For each period, antimicrobial prescriptions for all adult outpatients (hospitalized for <24h) were evaluated by an infectious disease specialist and an emergency department physician to assess compliance with local prescribing guidelines. Inappropriate prescriptions were then classified. FINDINGS: Before and after ASP, 34,671 and 35,925 consultations were registered at our emergency department, of which 25,470 and 26,208 were outpatients. Antimicrobials were prescribed in 769 (3.0%) and 580 (2.2%) consultations, respectively (P < 0.0001). There were 484 (62.9%) and 271 (46.7%) (P < 0.0001) instances of non-compliance with guidelines before and after ASP implementation. Non-compliance included unnecessary antimicrobial prescriptions, 197 (25.6%) vs 101 (17.4%) (P<0.0005); inappropriate spectrum, 108 (14.0%) vs 54 (9.3%) (P=0.008); excessive treatment duration, 87 (11.3%) vs 53 (9.1%) (P>0.05); and inappropriate choices, 11 (1.4%) vs 15 (2.6%) (P>0.05). CONCLUSION: The implementation of an ASP markedly decreased the number of unnecessary antimicrobial prescriptions, but had little impact on most other aspects of inappropriate prescribing.

Community-acquired Clostridium difficile infections in emergency departments.

OBJECTIVE: Clostridium difficile infection (CDI) has become an emerging infectious disease, especially in community settings. Little data is available on its frequency and characteristics in France. We aimed to describe CDI case patients consulting at the emergency department and to compare community-acquired and nosocomial CDIs. PATIENTS AND METHODS: We conducted a multicenter retrospective study over a three-year period of community-acquired and nosocomial CDI case patients seen at the emergency department and compared their characteristics. RESULTS: A total of 2055 patients consulted for diarrhea during the study period and had a stool culture performed: 66 (3.2%) presented with a CDI, of which 28 were community-acquired and 26 were nosocomial. Community-acquired CDI patients had a mean age of 57.7years (18-91), with a sex-ratio of 0.65. At least one risk factor was observed in 24 patients (85.7%), of whom 22 (78.6%) had been prescribed a previous antimicrobial treatment. Diabetes mellitus and renal failure were more frequently observed in patients presenting with nosocomial CDI. They required fluid replacement and needed be to re-hospitalized more often than community-acquired patients. CONCLUSION: Community-acquired CDIs in the emergency department account for approximately 1.4% of patients presenting with diarrhea. One risk factor is present in 85.7% of cases. In our study, their presentation and outcome seemed less severe than nosocomial CDIs.

Evaluating antibiotic therapies prescribed to adult patients in the emergency department.

OBJECTIVES: The proper use of antibiotics is a public health priority to preserve their effectiveness. Little data is available on outpatient antibiotic prescriptions, especially in the emergency department. We aimed to assess the quality of outpatient antibiotic prescriptions in our hospital. PATIENTS AND METHODS: Retrospective monocentric study of antibiotic prescriptions written to adult patients managed at the emergency department without hospitalization (November 15th, 2012-November 15th, 2013). Prescriptions were evaluated by an infectious disease specialist and an emergency physician on the basis of local recommendations compiled from national and international guidelines. RESULTS: A total of 760 prescriptions were reviewed. The most frequent indications were urinary tract infections (n=263; 34.6%), cutaneous infections (n=198; 26.05%), respiratory tract infections (n=101; 13.28%), and ENT infections (n=62; 8.15%). The most frequently prescribed antibiotics were fluoroquinolones (n=314; 40.83%) and amoxicillin-clavulanic acid (n=245; 31.85%). Overall, 455 prescriptions (59.86%) did not comply with guidelines. The main reasons for inadequacy were the absence of an indication for antibiotic therapy (n=197; 40.7%), an inadequate spectrum of activity, i.e. too broad, (n=95; 19.62%), and excessive treatment duration (n=87; 17.97%). Rates of inadequate prescriptions were 82.26% for ENT infections, 71.2% for cutaneous infections, 46.53% for respiratory tract infections, and 38.4% for urinary tract infections. CONCLUSION: Antibiotic prescriptions written to outpatients in the emergency department are often inadequate. Enhancing prescribers' training and handing out guidelines is therefore necessary. The quality of these prescriptions should then be re-assessed.

HSV-2 meningoencephalitis in an immunocompetent young man: what is the pathogenesis and what is the treatment?

Herpes simplex encephalitis is rarely caused by herpes simplex virus type 2 (HSV-2) after the neonatal period. The pathogenesis of HSV-2 encephalitis is not known and its treatment has not been discussed. We report a case of mild meningoencephalitis secondary to HSV-2 primary infection after sexual risk behaviour in a healthy young man. The diagnosis was established upon clinical, biological and electroencephalographic criteria. Aciclovir treatment led to rapid clinical improvement. This case highlights HSV-2 as a rare cause of meningoencephalitis, and questions the management of this rare manifestation of HSV-2 infection.

CDK/CK1 inhibitors roscovitine and CR8 downregulate amplified MYCN in neuroblastoma cells.

To understand the mechanisms of action of (R)-roscovitine and (S)-CR8, two related pharmacological inhibitors of cyclin-dependent kinases (CDKs), we applied a variety of '-omics' techniques to the human neuroblastoma SH-SY5Y and IMR32 cell lines: (1) kinase interaction assays, (2) affinity competition on immobilized broad-spectrum kinase inhibitors, (3) affinity chromatography on immobilized (R)-roscovitine and (S)-CR8, (4) whole genome transcriptomics analysis and specific quantitative PCR studies, (5) global quantitative proteomics approach and western blot analysis of selected proteins. Altogether, the results show that the major direct targets of these two molecules belong to the CDKs (1,2,5,7,9,12), DYRKs, CLKs and CK1s families. By inhibiting CDK7, CDK9 and CDK12, these inhibitors transiently reduce RNA polymerase 2 activity, which results in downregulation of a large set of genes. Global transcriptomics and proteomics analysis converge to a central role of MYC transcription factors downregulation. Indeed, CDK inhibitors trigger rapid and massive downregulation of MYCN expression in MYCN-amplified neuroblastoma cells as well as in nude mice xenografted IMR32 cells. Inhibition of casein kinase 1 may also contribute to the antitumoral activity of (R)-roscovitine and (S)-CR8. This dual mechanism of action may be crucial in the use of these kinase inhibitors for the treatment of MYC-dependent cancers, in particular neuroblastoma where MYCN amplification is a strong predictor factor for high-risk disease.

Identification of an ataxia telangiectasia-mutated protein mediated surveillance system to regulate Bcl-2 overexpression.

Bcl-2 can both promote and attenuate tumorigenesis. Although the former function is relatively well characterized, the mechanism of the latter remains elusive. We report here that enforced Bcl-2 expression in MCF7 cells stabilizes p53, induces phosphorylation of p53 serine 15 (p53pSer15) and inhibits MCF7 cell growth. Consistent with p53 Ser15 being a target of ataxia telangiectasia mutated protein(ATM)/ATR (ATM- and rad3-related) in the DNA damage response, Bcl-2 activates ATM by inducing ATM Ser1981 phosphorylation, which is accompanied with the phosphorylaton of two additional ATM substrates, Chk2 Thr68 and H2AX Ser139. Downregulation of ATM using a specific small interference RNA fragment (ATMRNAi) abolished Bcl-2-induced p53pSer15 and Bcl-2-mediated growth inhibition of MCF7 cells. Ectopic expression of a dominant-negative p53 mutant, p53175H, partially rescued this growth inhibition. Taken together, these observations demonstrate the contribution of ATM-p53 function to Bcl-2-mediated inhibition of MCF7 cell growth, indicating an ATM-mediated surveillance system for regulating Bcl-2 overexpression. Consistent with this concept, we found that MCF7 cells express Bcl-2 heterogeneously with 34.5% of cells being Bcl-2 negative. In general, Bcl-2-positive MCF7 cells proliferate slower than those of Bcl-2 negative. Thus, we provide evidence suggesting that activation of ATM suppresses Bcl-2-induced tumorigenesis, and that attenuation of ATM function may be an important event in breast cancer progression.

Mutant p53 cooperates with ETS and selectively up-regulates human MDR1 not MRP1.

The most frequently expressed drug resistance genes, MDR1 and MRP1, occur in human tumors with mutant p53. However, it was unknown if mutant p53 transcriptionally regulated both MDR1 and MRP1. We demonstrated that mutant p53 did not activate either the MRP1 promoter or the endogenous gene. In contrast, mutant p53 strongly up-regulated the MDR1 promoter and expression of the endogenous MDR1 gene. Notably, cells that expressed either a transcriptionally inactive mutant p53 or the empty vector showed no endogenous MDR1 up-regulation. Transcriptional activation of the MDR1 promoter by mutant p53 required an Ets binding site, and mutant p53 and Ets-1 synergistically activated MDR1 transcription. Biochemical analysis revealed that Ets-1 interacted exclusively with mutant p53s in vivo but not with wild-type p53. These findings are the first to demonstrate the induction of endogenous MDR1 by mutant p53 and provide insight into the mechanism.

Caspase 8 is deleted or silenced preferentially in childhood neuroblastomas with amplification of MYCN.

Caspase 8 is a cysteine protease regulated in both a death-receptor-dependent and -independent manner during apoptosis. Here, we report that the gene for caspase 8 is frequently inactivated in neuroblastoma, a childhood tumor of the peripheral nervous system. The gene is silenced through DNA methylation as well as through gene deletion. Complete inactivation of CASP8 occurred almost exclusively in neuroblastomas with amplification of the oncogene MYCN. Caspase 8-null neuroblastoma cells were resistant to death receptor- and doxorubicin-mediated apoptosis, deficits that were corrected by programmed expression of the enzyme. Thus, caspase 8 acts as a tumor suppressor in neuroblastomas with amplification of MYCN.

Cycloheximide-induced T-cell death is mediated by a Fas-associated death domain-dependent mechanism.

Cycloheximide (CHX) can contribute to apoptotic processes, either in conjunction with another agent (e.g. tumor necrosis factor-alpha) or on its own. However, the basis of this CHX-induced apoptosis has not been clearly established. In this study, the molecular mechanisms of CHX-induced cell death were examined in two different human T-cell lines. In T-cells undergoing CHX-induced apoptosis (Jurkat), but not in T-cells resistant to the effects of CHX (CEM C7), caspase-8 and caspase-3 were activated. However, the Fas ligand was not expressed in Jurkat cells either before or after treatment with CHX, suggesting that the activation of these caspases does not involve the Fas receptor. To determine whether CHX-induced apoptosis was mediated by a Fas-associated death domain (FADD)-dependent mechanism, a FADD-DN protein was expressed in cells prior to CHX treatment. Its expression effectively inhibited CHX-induced cell death, suggesting that CHX-mediated apoptosis primarily involves a FADD-dependent mechanism. Since CHX treatment did not result in the induction of Fas or FasL, and neutralizing anti-Fas and anti-tumor necrosis factor receptor-1 antibodies did not block CHX-mediated apoptosis, these results may also indicate that FADD functions in a receptor-independent manner. Surprisingly, death effector filaments containing FADD and caspase-8 were observed during CHX treatment of Jurkat, Jurkat-FADD-DN, and CEM C7 cells, suggesting that their formation may be necessary, but not sufficient, for cell death.

Structure and chromosome localization of the human CASP8 gene.

The human CASP8 gene, whose product is also known as caspase 8 and FLICE, encodes an interleukin-1beta converting enzyme (ICE)-related cysteine protease that is activated by the engagement of several different death receptors. Caspase 8 is immediately recruited to the Fas receptor once it oligomerizes, and its protease activity is crucial for the apoptotic response generated by the resulting death-inducing signaling complex (DISC). We report here that the CASP8 gene contains at least 11 exons spanning approximately 30kb on human chromosome band 2q33-34. This region of human chromosome 2 was previously reported as the location of the CASP10 gene, whose product is closely related to caspase 8. Chromosome 2 band q33-34 is also involved in tumorigenesis, with loss of heterogeneity (LOH) being reported in a number of tumors. We also report EcoRI and HindIII polymorphisms that may prove to be useful in disease analysis. Both caspases 8 and 10 contain long pro-domains with duplicated death effector domains (DEDs), as well as their corresponding cysteine protease catalytic domains. Thus, it appears that CASP8 and CASP10 have evolved by tandem gene duplication, much like the CASP1, CASP4 and CASP5 gene cluster on human chromosome 11q22.2-22.3.

Duplication of a genomic region containing the Cdc2L1-2 and MMP21-22 genes on human chromosome 1p36.3 and their linkage to D1Z2.

Cdc2L1 and Cdc2L2 span approximately 140 kb on human chromosome 1p36.3. The products of the Cdc2L genes encode almost identical protein kinases, the PITSLRE kinases, which have functions that may be relevant to the regulation of transcription/splicing and apoptotic signaling. These genes are deleted/translocated in neuroblastomas with MYCN gene amplification, a subset of malignant melanomas, and in a newly delineated deletion syndrome. Here we report that the p36.3 region of human chromosome 1 consists of two identical genomic regions, each of which contain a Cdc2L gene linked to a metalloprotease (MMP) gene in a tail-to-tail configuration. This duplicated genomic region is also linked tightly to D1Z2, a genetic marker containing a highly polymorphic VNTR (variable number tandem repeat) consisting of an unusual 40-bp reiterated sequence. Thus, these genes and the polymorphic marker D1Z2 are organized as follows: telomere-D1Z2-5'-MMP22-3'-3'-Cdc2L2-5'-5'-Cdc2L1 -3'- 3'-MMP21-5'-centromere. Remarkably, the introns and exons of Cdc2L1 and Cdc2L2, as well as their flanking regions, are essentially identical. A total of 15 amino acid differences, 12 nonconservative and 3 conservative, can be found in the 773-786 amino acids specified by the various products of the Cdc2L genes. Two separate promoter/5' untranslated (UT) regions, CpG1 and CpG2, are identical to a reported previously methylated genomic CpG sequence and are used to express >20 different Cdc2L transcripts from the two genes. The expression of CpG2 transcripts from Cdc2L1 and Cdc2L2 is tissue/cell-line specific. CpG1 transcripts are expressed ubiquitously from both genes, with perhaps some bias towards the expression of CpG1 Cdc2L1 mRNAs in certain hematopoietic cells.

Isolation and characterization of two novel metalloproteinase genes linked to the Cdc2L locus on human chromosome 1p36.3.

The terminal end of the short arm of human chromosome 1, 1p36.3, is frequently deleted in a number of tumors and is believed to be the location of multiple tumor suppressor genes. Thus far, a bona fide tumor suppressor gene from this region has not been identified. The isolation and characterization of new 1p36 genes is, therefore, of some interest. Two novel matrix metalloproteinase genes, MMP21 and MMP22, have been identified in the Cdc2L1-2 locus, which spans approximately 120 kb on 1p36.3. These genes encode novel metalloproteinases that contain prepro, catalytic, cysteine-rich, interleukin-1 receptor-related, and proline-rich domains. Their catalytic domains are most closely related to stromelysin-3 and contain the consensus HEXXH zinc-binding region required for enzyme activation, while their cysteine-rich domains appear to be related to a number of human, mouse, and Caenorhabditis elegans metalloproteinase sequences. Of some possible interest is the absence of a highly conserved cysteine residue in the proenzyme domain, the so-called "cysteine switch," which has been shown to be involved in the autocatalytic activation of many metalloproteinases. The MMP genes are located less than 1 kb from the 3' regions of Cdc2L1 and Cdc2L2, suggesting that the MMP and Cdc2L genes are part of a larger region that has been duplicated. Finally, the MMP21/22 genes express multiple mRNAs, some of which are derived by alternative splicing, in a tissue-specific manner.

Duplication of the DR3 gene on human chromosome 1p36 and its deletion in human neuroblastoma.

The human DR3 gene, whose product is also known as Wsl-1/APO-3/TRAMP/LARD, encodes a tumor necrosis factor-related receptor that is expressed primarily on the surface of thymocytes and lymphocytes. DR3 is capable of inducing both NF-kappa B activation and apoptosis when overexpressed in mammalian cells, although its ligand has not yet been identified. We report here that the DR3 gene locus is tandemly duplicated on human chromosome band 1p36.2-p36.3 and that these genes are hemizygously deleted and/or translocated to another chromosome in neuroblastoma (NB) cell lines with amplified MYCN. Duplication of at least a portion of the DR3 gene, including the extracellular and transmembrane regions but not the cytoplasmic domain, was demonstrated by both fluorescence in situ hybridization and genomic Southern blotting. In most NB cell lines, both the DR3 and the DR3L sequences are simultaneously deleted and/or translocated to another chromosome. Finally, DR3/ Wsl-1 protein expression is quite variable among these NB cell lines, with very low or undetectable levels in 7 of 17 NB cell lines.

Structure and gene expression of avian cyclin D2.

Avian cyclin D2 (Cyl D2)-encoding cDNA clones were isolated from a chicken UG9 T-cell lambda gt10 library. Sequence analysis revealed a high degree of sequence conservation with both the mouse and human Cyl D2, and somewhat lower similarity with the mouse and human Cyl D1 and D3. The homology is highest between species in the Cyl-box domain which is well conserved among human, mouse and chicken. A single 6.0-kb CYL2 mRNA is produced in both avian B- and T-cells, as expected.

Structure and expression of chicken protein kinase PITSLRE-encoding genes.

The human PITSLRE protein kinases (PK), members of the p34cdc2 kinase family named according to the single amino acid (aa) code of an important (PSTAIRE) regulatory region [Meyerson et al., EMBO J. 11 (1992) 2909-2917], are candidate tumor suppressor gene(s) localized to human chromosome 1p36.2 and a syntenic region of mouse chromosome 4 [Lahti et al., Nature Genet. 7 (1994) 370-375; Mock et al., Mammal. Genome 5 (1994) 191-192]. At least ten isoforms of this PK family are expressed from three duplicated and tandemly linked genes in humans [Xiang et al., J. Biol. Chem. 269 (1994) 15786-15794]. We have now isolated two different species of PITSLRE PK cDNAs from chicken that encode identical polypeptides, but are clearly expressed from different genes, based on nucleotide (nt) differences. Isolation of one of the corresponding chicken PITSLRE PK genes confirms that only one of the two species of PITSLRE mRNA is expressed from this gene. Comparison of the predicted avian PITSLRE PK aa sequence to human and mouse sequences shows a high degree of sequence identity (> 91%). Like humans, the PITSLRE PK genes in chickens must be closely linked, based on fluorescent in situ hybridization (FISH) localization of these genes to a single chicken microchromosome. PITSLRE PK mRNAs are expressed in two avian B- and T-cell lines. These results suggest that the PITSLRE PK gene family has been well conserved evolutionarily, that the gene duplication observed in humans is not a recent event, and that expression of redundant PITSLRE mRNAs is observed in different vertebrate species.

Hydroxyurea-induced synchrony of DNA replication in the Kinetoplastida.

We have developed a reliable and reproducible method to induce synchrony of the DNA synthetic cycle in the Kinetoplastida. The method involves treatment of cultures with 20 mM hydroxyurea (HU) and fetal bovine serum. Both stationary-phase and exponential-phase cultures can be synchronized. However, in the case of exponential-phase cultures the population doubling time and rate of DNA synthesis of the population influenced the time of exposure to HU. The treatment of kinetoplastids with 20 mM HU did not adversely affect the cells as judged by oxygen consumption, RNA, and protein content. We postulate that the requirement for high HU levels, which would be toxic to vertebrate cells, may be due to a lower affinity of kinetoplastid ribonucleotide reductase, the target enzyme for HU. Some of the kinetoplastids are pathogens of man and his food chain. Consequently, the development of a reliable technique for synchronization of the kinetoplastids should not only permit a detailed analysis of their cellular and molecular biology but provide a means to collect and characterize biochemical and immunochemical substances relevant to the infectious process.

Alterations in the PITSLRE protein kinase gene complex on chromosome 1p36 in childhood neuroblastoma.

p58cdc2L1, a protein kinase implicated in apoptotic signaling, is one of eight separate kinases encoded by three tandemly duplicated and linked genes, which we have termed PITSLRE A, B and C. One allele of this complex on chromosome 1 was either deleted or translocated in each of 18 neuroblastoma cell lines with cytogenetically apparent 1p alterations. A protein encoded by this locus, PITSLRE gamma 1, was absent in three of the lines and a smaller, apparently truncated, PITSLRE polypeptide was found in another line. These findings identify a novel gene complex on chromosome 1 that encodes a protein kinase subfamily. We suggest that the PITSLRE locus may harbour one or more tumour suppressor genes affected by chromosome 1p36 modifications in neuroblastoma.

Molecular cloning and expression of alternatively spliced PITSLRE protein kinase isoforms.

Minimal ectopic expression of the p58GTA protein kinase results in a provocative phenotype involving cell cycle delay, mitotic catastrophe, and decreased cell viability. In addition, this kinase is well conserved evolutionarily, ubiquitously expressed, and its genes map to a position on human chromosome 1 frequently deleted in the late stages of tumorigenesis. Here we report that the p58GTA protein kinase is a member of a larger subfamily of proteins. The mRNAs encoding these proteins are generated by alternative splicing from multiple duplicated genes. These isoforms range in size from 50 to 110 kDa. Divergence between the alternatively spliced isoforms is localized to the amino-terminal region of the molecule. The entire p58GTA open reading frame is conserved in most of these p58GTA isoforms. The predicted sequences of the larger isoforms encode bipartite nuclear localization signal sequences and extensive polyglutamic acid domains. Antibodies to the p58GTA isoform were used to confirm the presence of the alternatively spliced isoforms in different cell types as well as identify two additional isoforms that appear to arise from a separate gene(s). Cellular fractionation studies indicate that one of the isoforms is found only in the nucleus, and the remainder are found in both the cytoplasm and the nucleus. Expression and localization of some p58GTA isoforms suggest that they may have specialized cellular functions. Because of the large number of isoforms generated from multiple genes we propose naming these kinases PITSLRE alpha 1, alpha 2-1, alpha 2-2, alpha 2-3 alpha 2-4, beta 1, beta 2-1, and beta 2-2 based on the conserved sequence of the PSTAIRE box unique to p34cdc2 kinases and the gene from which they are transcribed.

Effect of caffeine and isobutyl-methyl-xanthine on production of binucleate cells and on post-replicative repair.

Caffeine (CAF) but not 3-isobutyl 1-methyl-xanthine (IBMX) displayed a strong DNA anti-repair effect in G2 prophase, as estimated by the frequency of abnormal chromosomes in anaphase-telophase found shortly after treatment. IBMX is more effective than CAF in inhibiting cytokinesis, while the binucleate cells formed by a short treatment with any of these two xanthines have similar cycle kinetics.

Beta 1-4-galactosyltransferase gene expression is regulated during entry into the cell cycle and during the cell cycle.

Mammalian glycosyltransferases have been implicated in a wide variety of functions besides N-linked glycosylation, including developmental processes. For this reason, we studied the effects of cell cycle and entry into the cell cycle on beta 1-4-galactosyltransferase gene expression. In this study we report that beta 1-4-galactosyltransferase (GalTase) gene expression is, indeed, regulated during the normal cell cycle, peaking during late G1-, S, and early G2 phase of the cell cycle. In addition, GalTase gene expression is regulated in a manner that resembles other "early response" genes such as jun and fos upon reentry into the cell cycle from quiescence. Finally, we show that the GalTase gene is differentially expressed during murine embryogenesis and in terminally differentiated adult tissues. It is most abundant in testis, followed by skeletal muscle and spleen. The reasons for this pattern of differential expression in adult tissues are unknown. These studies should provide important new information regarding GalTase gene expression, its regulation, and its potential link to other developmental functions.