Increase in consumption of alcohol-based hand rub in German acute care hospitals over a 12 year period.

BACKGROUND: Hand hygiene plays a crucial role in the transmission of pathogens and the prevention of healthcare-associated infections. In 2007, a voluntary national electronic surveillance tool for the documentation of consumption of alcohol-based hand rub (AHC) was introduced as a surrogate for hand hygiene compliance (HAND-KISS) and for the provision of benchmark data as feedback. The aim of the study was to determine the trend in alcohol-based hand rub consumption between 2007 and 2018. MATERIALS AND METHODS: In this cohort study, AHC and patient days (PD) were documented on every ward in participating hospitals by trained local staff. Data was collected and validated in HAND-KISS. Intensive care units (ICU), intermediate care units (IMC), and regular wards (RW) that provided data during the study period between 2007 until 2018 were included into the study. RESULTS: In 2018, 75.2% of acute care hospitals in Germany (n = 1.460) participated. On ICUs (n = 1998) mean AHC increased 1.74 fold (95%CI 1.71, 1.76; p < .0001) from 79.2 ml/PD to 137.4 ml/PD. On IMCs (n = 475) AHC increased 1.69 fold (95%CI 1.60, 1.79; p < .0001) from 41.4 ml/PD to 70.6 ml /PD..On RWs (n = 14,857) AHC was 19.0 ml/PD in 2007 and increased 1.71 fold (95%CI 1.70, 1.73; p < .0001) to 32.6 ml/PD in 2018. CONCLUSIONS: AHC in German hospitals increased on all types of wards during the past 12 years. Surveillance of AHC is widely established in German hospitals. Large differences among medical specialties exist and warrant further investigation.

Hand Rub Consumption Has Almost Doubled in 132 German Hospitals Over 9 Years.

Annual surveillance data (2007-2015), collected continuously in 132 German hospitals, was evaluated for development of alcohol-based hand-rub consumption (AHC) as a surrogate parameter for hand hygiene adherence. Overall, the median increase in AHC was 94%. The increases over 9 years were significant in all units and quartiles of AHC at baseline. Infect Control Hosp Epidemiol 2017;38:870-872.

Freshly frozen E18 rat cortical cells can generate functional neural networks after standard cryopreservation and thawing procedures.

Primary dissociated brain tissue from rodents is widely used in a variety of different scientific methods to investigate cellular processes in vitro. Often, for this purpose cell cultures need to be generated just on time, requiring extensive animal lab infrastructure. We show here that cryopreservation and thawing of dissociated tissue from rat cerebral cortex at embryonic day 18 is feasible without affecting its ability to form functional neuronal networks in vitro. Vitality of fresh and re-thawed cortical cells was comparable, assessed by CellTiter-Blue-assay, CytoTox-ONE assay, immunocytochemical characterization and in vitro neuronal network activity recordings on microelectrode arrays. These findings suggest that planning and execution of experiments might be considerably facilitated by using cryo-preserved neurons instead of acutely dissociated neural cultures due to fewer logistical issues with regard to animal breeding and pregnancy timed preparations.

Species-dependent differences of embryonic stem cell-derived neural stem cells after Interferon gamma treatment.

Pluripotent stem cell (pSC)-derived, neural stem cells (NSCs) are actually extensively explored in the field of neuroregeneration and to clarify disease mechanisms or model neurological diseases in vitro. Regarding the latter, proliferation and differentiation of pSC-derived NSCs are investigated under the influence of a variety of different substances among them key players of inflammation. However, results generated on a murine genetic background are not always representative for the human situation which increasingly leads to the application of human cell culture systems derived from human pSCs. We investigated here, if the recently described interferon gamma (IFNγ)-induced dysregulated neural phenotype characterized by simultaneous expression of glial and neuronal markers on murine NSCs (Walter et al., 2011, 2012) can also be found on a human genetic background. For this purpose, we performed experiments with human embryonic stem cell-derived NSCs. We could show that the IFNγ-induced dysregulated neural phenotype cannot be induced in human NSCs. This difference occurs, although typical genes like signal transducers and activators of transcription 1 (Stat 1) or interferon regulatory factor 9 (IRF-9) are similarly regulated by IFNγ in both, murine and human populations. These results illustrate that fundamental differences between murine and human neural populations exist in vitro, independent of anatomical system-related properties.

Interferon gamma and sonic hedgehog signaling are required to dysregulate murine neural stem/precursor cells.

BACKGROUND: The pro-inflammatory cytokine interferon gamma (IFNγ), a key player in various neurological diseases, was recently shown to induce a dysregulated phenotype in neural stem/precursor cells (NSPCs) that is characterized by the simultaneous expression of glial and neuronal markers and irregular electrophysiological properties. Thus far, the mechanisms of this phenomenon have remained unclear. METHODOLOGY/PRINCIPAL FINDINGS: To determine if binding of the signal transducers and activators of transcription (Stat 1) to the sonic hedgehog (SHH) promoter is important for this phenomenon to occur, chromatin immunoprecipitation and pharmacological inhibition studies were performed. We report here that the activation of both the Stat 1 and SHH pathways is necessary to elicit the dysregulated phenotype. CONCLUSIONS/SIGNIFICANCE: Thus, blocking these pathways might preserve functional differentiation of NSPCs under inflammatory conditions leading to more effective regeneration.

Flavin mononucleotide-based fluorescent proteins function in mammalian cells without oxygen requirement.

Usage of the enhanced green fluorescent protein (eGFP) in living mammalian cells is limited to aerobic conditions due to requirement of oxygen during chromophore formation. Since many diseases or disease models are associated with acute or chronic hypoxia, eGFP-labeling of structures of interest in experimental studies might be unreliable leading to biased results. Thus, a chromophore yielding a stable fluorescence under hypoxic conditions is desirable. The fluorescence of flavin mononucleotide (FMN)-based fluorescent proteins (FbFPs) does not require molecular oxygen. Recently, the advantages of FbFPs for several bacterial strains and yeasts were described, specifically, their usage as a real time fluorescence marker in bacterial expression studies and their ability of chromophore formation under anaerobic conditions. Our objective was to verify if FbFPs also function in mammalian cells in order to potentially broaden the repertoire of chromophores with ones that can reliably be used in mammalian studies under hypoxic conditions. In the present study, we demonstrate for the first time, that FbFPs can be expressed in different mammalian cells, among them murine neural stem cells during proliferative and differentiated stages. Fluorescence intensities were comparable to eGFP. In contrast to eGFP, the FbFP fluorescence did not decrease when cells were exposed to defined hypoxic conditions neither in proliferating nor in differentiated cells. Thus, FbFPs can be regarded as an alternative to eGFP in studies that target cellular structures which are exposed to hypoxic conditions.

Ammonium chloride influences in vitro-neuronal network activity.

UNLABELLED: The objective of the present work is to image functional alterations in hepatic encephalopathy (HE) by ammonia-induced changes of in vitro-neuronal network activity and to identify counteracting strategies. Synchronous bursting behavior of rat cortical cells which is the result of synaptic interaction of excitatory and inhibitory neurons was recorded in vitro on microelectrode arrays (MEAs) after ammonium chloride exposure. In order to test the involvement of astrocytic glutamine metabolism and N-methyl-d-aspartic acid- (NMDA-) receptor function in the observed ammonia-induced network dysregulation and to identify potentially protective strategies, we investigated effects of the glutamine synthetase (GS) inhibitor methionine-sulfoximine (MSO) and the NMDA-receptor antagonist DL-2-Amino-5-phosphono-pentanoic acid (AP-5), respectively. We observed a characteristic ammonia-induced increase of global network activity while network synchrony was suppressed. The increase of global activity, but not the suppression of network synchrony was prevented by inhibiting GS. However, blocking NMDA-receptors prevented both, network excitation and desynchronization. CONCLUSIONS: 1. The observed desynchronization of in vitro-neuronal network activity after ammonium chloride treatment might reflect global neuronal network changes in HE in vivo and suggests the MEA technology as a valuable tool for measuring changes of neuronal connectivity in vitro. 2. Astrocytic glutamine metabolism might be involved in increased global network activity, but not in the suppression of network synchrony. 3. Overactivation of NMDA-receptors might underlie both, the ammonia-induced increase of activity and suppression of network synchrony, suggesting that NMDA-receptor function is involved in HE and that their blockage might be protective. 4. Measuring neuronal network activity in vitro by the MEA technology might help to describe functionally protective measures in HE.

A new role for interferon gamma in neural stem/precursor cell dysregulation.

BACKGROUND: The identification of factors that compromise neurogenesis is aimed at improving stem cell-based approaches in the field of regenerative medicine. Interferon gamma (IFNγ) is a main pro-inflammatory cytokine and up-regulated during several neurological diseases. IFNγ is generally thought to beneficially enhance neurogenesis from fetal or adult neural stem/precursor cells (NSPCs). RESULTS: We now provide direct evidence to the contrary that IFNγ induces a dysfunctional stage in a substantial portion of NSPC-derived progeny in vitro characterized by simultaneous expression of glial fibrillary acid protein (GFAP) and neuronal markers, an abnormal gene expression and a functional phenotype neither typical for neurons nor for mature astrocytes. Dysfunctional development of NSPCs under the influence of IFNγ was finally demonstrated by applying the microelectrode array technology. IFNγ exposure of NSPCs during an initial 7-day proliferation period prevented the subsequent adequate differentiation and formation of functional neuronal networks. CONCLUSIONS: Our results show that immunocytochemical analyses of NSPC-derived progeny are not necessarily indicating the correct cellular phenotype specifically under inflammatory conditions and that simultaneous expression of neuronal and glial markers rather point to cellular dysregulation. We hypothesize that inhibiting the impact of IFNγ on NSPCs during neurological diseases might contribute to effective neurogenesis and regeneration.

Neural precursor cells as a novel target for interferon-beta.

The immunomodulating agent interferon-beta (IFNbeta) is administered therapeutically in several autoimmune diseases and endogenously released by immune cells during diverse infections. As in recent years a variety of pro- and anti-inflammatory substances were shown to influence significantly neural precursor cells that are implicated in a variety of regenerative mechanisms but also in tumor growth, we studied a possible effect of IFNbeta on neural precursor cells derived from murine embryonic day 14 neurospheres. First, we demonstrated that interferon type-I receptors are expressed on neural precursor cells and that these cells respond to IFNbeta treatment by up-regulating IFNbeta inducible genes including Myxovirus 1 and viperin. Furthermore, we could show for the first time that IFNbeta treatment significantly inhibited the proliferation of neural precursor cells possibly through induction of p21, a cyclin-dependent kinase inhibitor. IFNbeta did not exert cytotoxic or neuroprotective effects and we could not see effects on the differentiation of neural precursor cells into total amounts of neurons, astrocytes or oligodendrocytes. However, we found that IFNbeta markedly diminished neurite outgrowth and neuronal maturation of neural precursor-derived neurons.