Multidisciplinary neurosurgical rounds incorporating antimicrobial stewardship. Are they of benefit?

Background: In an era of increasing antimicrobial resistance, appropriate antimicrobials are essential to optimise patient outcomes. In 2017, antimicrobial use prevalence (AMU) on the two neurosurgical wards in our tertiary teaching hospital varied from 23% on ward A to 33% on ward B with 67% and 100% 'appropriate' prescriptions, respectively. In July 2018, a weekly antimicrobial stewardship multidisciplinary round led by a senior neurosurgery registrar commenced, attended by the antimicrobial stewardship team (AST). Research question: This report evaluates whether a multi-disciplinary approach on neurosurgical prescribing was beneficial, specifically in reducing AMU. Materials and methods: The following data was collected on AST rounds for 30 weeks in total from August 2018 to July 2019: number of patients on antimicrobials, appropriateness and stewardship actions. A questionnaire was distributed to neurosurgical doctors on two occasions to canvass opinions and attitudes on antimicrobial prescribing. Results: 1716 prescriptions were reviewed (mean 57.2 per week). Of these 321 (18.7%) included antimicrobial prescriptions; 200 on ward A (19.8%), and 121 on ward B (17%), representing a decrease in AMU from 2017. The majority of antimicrobial prescriptions, 271 (84.4%) were deemed appropriate. Stewardship actions were taken in 215 (67%) prescriptions.Fifteen questionnaires were completed by neurosurgical doctors. The majority, 87%, stated the AST round was helpful overall. 93% indicated that informal training on the AST round was a source of education in antibiotic prescribing. Discussion and conclusion: The weekly AST round provided a timely opportunity for multidisciplinary discussion, implementation of antimicrobial stewardship actions and opportunistic antimicrobial stewardship education.

Correction: The induction of core pluripotency master regulators in cancers defines poor clinical outcomes and treatment resistance.

The original version of this article contained an error in Fig. 5a where the colours of the labels representing the Hinge and LBD of the AR were incorrect and did not match the corresponding exons. The corrected version of this Figure now appears in the article. The conclusions of this paper were not affected. The authors apologise for this error and any confusion caused.

The induction of core pluripotency master regulators in cancers defines poor clinical outcomes and treatment resistance.

Stem cell characteristics have been associated with treatment resistance and poor prognosis across many cancer types. The ability to induce and regulate the pathways that sustain these characteristic hallmarks of lethal cancers in a novel in vitro model would greatly enhance our understanding of cancer progression and treatment resistance. In this work, we present such a model, based simply on applying standard pluripotency/embryonic stem cell media alone. Core pluripotency stem cell master regulators (OCT4, SOX2 and NANOG) along with epithelial-mesenchymal transition (EMT) markers (Snail, Slug, vimentin and N-cadherin) were induced in human prostate, breast, lung, bladder, colorectal, and renal cancer cells. RNA sequencing revealed pathways activated by pluripotency inducing culture that were shared across all cancers examined. These pathways highlight a potential core mechanism of treatment resistance. With a focus on prostate cancer, the culture-based induction of core pluripotent stem cell regulators was shown to promote survival in castrate conditions-mimicking first line treatment resistance with hormonal therapies. This acquired phenotype was shown to be mediated through the upregulation of iodothyronine deiodinase DIO2, a critical modulator of the thyroid hormone signalling pathway. Subsequent inhibition of DIO2 was shown to supress expression of prostate specific antigen, the cardinal clinical biomarker of prostate cancer progression and highlighted a novel target for clinical translation in this otherwise fatal disease. This study identifies a new and widely accessible simple preclinical model to recreate and explore underpinning pathways of lethal disease and treatment resistance.

Food for thought. Malnutrition risk associated with increased risk of healthcare-associated infection.

BACKGROUND: Infection and malnutrition are interconnected. UK and Irish guidelines recommend the Malnutrition Universal Screening Tool (MUST) for nutritional risk screening. Patients with a MUST score of ≥2 are considered at high risk of malnutrition and referral for nutritional assessment is recommended. AIM: To explore the association between healthcare-associated infection (HCAI) and the MUST score categories of patients. METHODS: This was a cross-sectional study in May 2017 on ten representative wards in our institution. Patient demographics, MUST score, presence of medical devices, HCAI and antimicrobial use were collected. FINDINGS: Of 240 patients, the HCAI prevalence was 10.4% (N = 25) and 26% (N = 63) were at high risk of malnutrition (MUST score ≥2). Patients with HCAI were more likely to have had surgery (odds ratio (OR): 5.5; confidence interval (CI): 2.1-14.3; P < 0.001), a central vascular catheter (OR: 10.0; CI: 3.6-27.2; P < 0.001), or a urinary catheter in situ (OR: 7.5; CI: 2.8-20.0; P < 0.001), and to have a high risk of malnutrition (OR: 4.3; CI: 1.7-11.2; P < 0.001). A higher MUST score remained a significant predictor of a patient having HCAI on multivariate regression analysis (CI: 0.2-0.6; P < 0.001). CONCLUSION: Patients at risk of malnutrition when assessed with the MUST were more likely to have HCAI. However, prospective studies are required to investigate the temporal association between MUST and HCAI and which interventions best address malnutrition risk and HCAI reduction in different settings.

The potential contribution of 16S ribosomal RNA polymerase chain reaction to antimicrobial stewardship in culture-negative infection.

Empiric broad-spectrum antimicrobial therapy frequently results in culture-negative specimens making rationalization of therapy difficult. We retrospectively reviewed 16S rRNA polymerase chain reaction (PCR) results from 78 specimens in 60 patients. 16S rRNA was detected in 28 (47%) patients with de-escalation of therapy in five (21%). Microbial DNA was not detected in 32 (53%) patients with antimicrobials discontinued in two (8%). Neurosurgical patients had a higher proportion of positive results (53% vs 34%) and treatment rationalizations (17% vs 12%). In specific patient groups, 16s rRNA PCR is a useful antimicrobial stewardship tool for targeting antimicrobial therapy.

Evaluation of fixed and variable hospital costs due to Clostridium difficile infection: institutional incentives and directions for future research.

BACKGROUND: Economic analysis of Clostridium difficile infection (CDI) should consider the incentives facing institutional decision-makers. To avoid overstating the financial benefits of infection prevention, fixed and variable costs should be distinguished. AIM: To quantify CDI fixed and variable costs in a tertiary referral hospital during August 2015. METHODS: A micro-costing analysis estimated CDI costs per patient, including the additional costs of a CDI outbreak. Resource use was quantified after review of patient charts, pharmacy data, administrative resource input, and records of salary and cleaning/decontamination expenditure. FINDINGS: The incremental cost of CDI was €75,680 (mean: €5,820 per patient) with key cost drivers being cleaning, pharmaceuticals, and length of stay (LOS). Additional LOS ranged from 1.75 to 22.55 days. For seven patients involved in a CDI outbreak, excluding the value of the 58 lost bed-days (€34,585); costs were 30% higher (€7,589 per patient). Therefore, total spending on CDI was €88,062 (mean: €6,773 across all patients). Potential savings from variable costs were €1,026 (17%) or €1,768 (26%) if outbreak costs were included. Investment in an antimicrobial pharmacist would require 47 CDI cases to be prevented annually. Prevention of 5%, 10% and 20% CDI would reduce attributable costs by €4,403, €8,806 and €17,612. Increasing the incremental LOS attributable to CDI to seven days per patient would have increased costs to €7,478 or €8,431 (if outbreak costs were included). CONCLUSION: As much CDI costs are fixed, potential savings from infection prevention are limited. Future analysis must consider more effectively this distinction and its impact on institutional decision-making.

The RNA-binding and adaptor protein Sam68 modulates signal-dependent splicing and transcriptional activity of the androgen receptor.

The RNA-binding protein Sam68 has been reported to be up-regulated in clinical cases of prostate cancer (PCa), where it is thought to contribute to cell proliferation and survival. Consistent with this, we observed over-expression of Sam68 in a panel of clinical prostate tumours as compared with benign controls. Since Sam68 is implicated in a number of signalling pathways, we reasoned that its role in PCa may involve modulation of the androgen receptor (AR) signalling cascade, which drives the onset and progression of PCa. We found that Sam68 interacts with the AR in vivo in LNCaP cells, and is dynamically recruited to androgen response elements within the promoter region of the prostate-specific antigen (PSA) gene. Based on its known functions and nuclear location, Sam68 might either: (a) co-regulate AR-dependent transcription positively or negatively; or (b) modulate AR-dependent alternative splicing by enhancing incorporation of a Sam68-responsive exon transcribed under the control of an androgen-responsive promoter. We tested these possibilities using functional assays. Both wild-type Sam68 protein and the Sam68(V229F) mutant, which is impaired in RNA binding, functioned as a ligand-dependent AR co-activator on an androgen-regulated reporter gene. In contrast, splicing of a Sam68-responsive variable exon, transcribed under control of an androgen-responsive promoter, was strongly repressed in the presence of AR and androgens. This splicing inhibition was reversed by ectopic expression of Sam68 but enhanced by Sam68(V229F). These results demonstrate that Sam68 has separable effects on AR-regulated transcriptional activity and alternative splicing, both of which may affect PCa phenotypes.

Tip60 is a co-activator specific for class I nuclear hormone receptors.

The nuclear hormone receptor superfamily is composed of a group of hormone-dependent transcription factors that play prominent roles in homeostatic events in vertebrates. A prerequisite for steroid hormone receptor activity is the binding of co-activator molecules to the activation function-2 domain of the receptor. The LXXLL motif/nuclear receptor box, contained within a number of co-activator molecules, mediates the interaction with nuclear hormone receptors. Tip60 (Tat-interactive protein 60 kDa), previously shown to bind to and enhance androgen receptor (AR)-mediated transactivation, contains a single nuclear receptor box at its extreme C terminus. We demonstrate that unlike members of the p160 co-activator family that interact predominantly with the N terminus of the AR in an LXXLL motif-independent manner, the LXXLL motif of Tip60 is required and is sufficient for AR interaction. Furthermore, by using the mammalian two-hybrid system and transient transfection experiments, we show that Tip60 preferentially interacts with and up-regulates class I nuclear receptors, suggesting that Tip60 is a steroid hormone receptor-specific co-activator. We conclude that Tip60 may specifically regulate a subset of nuclear hormone receptors, giving an indication to how regulated nuclear receptor activation can be achieved.

Androgen receptor nuclear translocation is facilitated by the f-actin cross-linking protein filamin.

The human androgen receptor (hAR) is a ligand-dependent transcription factor responsible for the development of the male phenotype. The mechanism whereby nuclear translocation of the hAR is induced by its natural ligand 5alpha-dihydrotestosterone is a phenomenon not fully understood. The two-hybrid interaction trap assay has been used to isolate proteins that interact with the hAR in an attempt to identify molecules involved in hAR transactivation and movement. We have identified the actin-binding protein filamin, a 280-kDa component of the cytoskeleton, as an hAR interacting protein. This interaction is ligand independent but is enhanced in its presence. The functional significance of this interaction was analyzed using a cell line deficient in filamin via transient expression of a green fluorescent protein-hAR chimera. In filamin-deficient cells this revealed that hAR remained cytoplasmic even after prolonged exposure to synthetic ligand. Nuclear shuttling was restored when this cell line regained wild-type expression of filamin. These data suggest a novel role for filamin, implicating it as an important molecule in AR movement from the cytoplasm to the nucleus.

Tip60 is a nuclear hormone receptor coactivator.

The androgen receptor (AR) is a member of the nuclear hormone receptor superfamily. Recent work in this field has been focused upon defining the mechanisms of transcriptional control exacted by members of this superfamily. Using a COOH-terminal region of the human AR in a yeast two-hybrid screen, we have identified Tip60 as an AR-interacting protein. In this report, we show that Tip60, which was originally identified as a coactivator for the human immunodeficiency virus TAT protein, can enhance AR-mediated transactivation in a ligand-dependent manner in LNCaP and COS-1 cell lines. In addition, our experiments show that Tip60 can also enhance transactivation through the estrogen receptor and progesterone receptor in a ligand-dependent manner; thus identifying Tip60 as a nuclear hormone receptor coactivator. Our studies also demonstrate that Tip60 co-immunoprecipitates with the full-length AR in vitro and that, in our system, Tip60 enhances transactivation to levels observed with the coactivators steroid receptor coactivator 1, p300, and CREB-binding protein. The importance of such proteins in enhancing nuclear hormone receptor-mediated transcriptional activation is widely accepted, and this work suggests that Tip60 may have an equally important role to play.

Identification of patient-controlled analgesia overdoses in hospitalized patients: a computerized method of monitoring adverse events.

OBJECTIVE: To describe and validate a computer-based quality assurance method that detects narcotic overdoses associated with patient-controlled analgesia (PCA) use. SETTING: Two acute care teaching hospitals. PATIENTS: 4669 patients who received PCA. INTERVENTIONS: The following patient lists were obtained during a two-year period from both hospital information systems: those who received PCA and (1) received naloxone, a narcotic antagonist, (2) were transferred to an intensive care unit, (3) had a cardiac or respiratory arrest, or (4) died. Possible overdoses were defined as patients who appeared on the PCA list and one of the other lists. Charts were reviewed if the patient's name appeared on the PCA and one of the other lists. Patients were judged to have experienced a narcotic overdose if there was an immediate improvement in blood pressure, respiratory rate, or mental status after the administration of naloxone. RESULTS: The search strategy identified 294 possible overdoses in 1499 patients who received PCA. Ten charts were unavailable for review. An actual overdose occurred in 11 patients. The accuracy of the new method was compared with that of the hospitals' present reporting methods. Eleven overdoses were identified by the computer search, but only 6 overdoses were identified in incident and adverse drug reaction reports. CONCLUSIONS: The systematic computer search identified almost twice as many adverse incidents than were reported by the traditional hospital methods.

Structure-biodegradability relationships in pyrethroid insecticides.

The metabolism of 20 pyrethroids has been examined to evaluate the contribution of detoxification in their selective action between insects and mammals. The studies utilized living houseflies, mice, or rats, or esterase and oxidase systems derived from these organisms. Pyrethroid-hydrolyzing esterases cleave the primary alcohol trans-substituted-cyclopropanecarboxylates much faster than the corresponding cis-isomers but are ineffective in hydrolyzing secondary alcohol esters. Microsomal enzymes oxidize the (+)-trans-chrysanthemate moiety at the trans-methyl group of the isobutenyl substituent and at one of the gem-dimethyl groups whereas the (+)-cis-isomer is attacked at either of the isobutenyl methyl groups. Products isomerized at C3 of the cyclopropane are also detected but only after ester cleavage and oxidation of an isobutenyl methyl group. Each alcohol moiety has its own unique sites for oxidation involving pentadienyl, allyl, benzylic methylene, and aromatic substituents. An enhancement of insecticidal activity is expected on replacement of the biodegradable groupings with substituents relatively resistant to metabolism but this may also increase the mammalian toxicity.