Assessment of the effectiveness of weight-adjusted antibiotic administration, for reduced duration, in surgical prophylaxis of primary hip and knee arthroplasty

BACKGROUND

Prophylactic antibiotics have significantly led to a reduction in the risk of post-operative surgical site infections (SSI) in orthopaedic surgery. The aim of using antibiotics for this purpose is to achieve serum and tissue drug levels that exceed, for the duration of the operation, the minimum inhibitory concentration of the likely organisms that are encountered. Prophylactic antibiotics reduce the rate of SSIs in lower limb arthroplasty from between 4% and 8% to between 1% and 3%. Controversy, however, still surrounds the optimal frequency and dosing of antibiotic administration.

AIM

To evaluate the impact of introduction of a weight-adjusted antibiotic prophylaxis regime, combined with a reduction in the duration of administration of post-operative antibiotics on SSI incidence during the 2 years following primary elective total hip and knee arthroplasty.

METHODS

Following ethical approval, patients undergoing primary total hip arthroplasty (THA)/total knee arthroplasty (TKA) with the old regime (OR) of a preoperative dose [cefazolin 2 g intravenously (IV)], and two subsequent doses (2 h and 8 h), were compared to those after a change to a new regime (NR) of a weight-adjusted preoperative dose (cefazolin 2 g IV for patients < 120 kg; cefazolin 3g IV for patients > 120 kg) and a post-operative dose at 2 h. The primary outcome in both groups was SSI rates during the 2 years post-operatively.

RESULTS

A total of n = 1273 operations (THA n = 534, TKA n = 739) were performed in n = 1264 patients. There was no statistically significant difference in the rate of deep (OR 0.74% (5/675) vs NR 0.50% (3/598); fishers exact test P = 0.72), nor superficial SSIs (OR 2.07% (14/675) vs NR 1.50% (9/598); chi-squared test P = 0.44) at 2 years post-operatively. With propensity score weighting and an interrupted time series analysis, there was also no difference in SSI rates between both groups [RR 0.88 (95%CI 0.61 to 1.30) P = 0.46].

CONCLUSION

A weight-adjusted regime, with a reduction in number of post-operative doses had no adverse impact on SSI incidence in this population.

Evaluating a pilot, structured, face-to-face, antimicrobial stewardship, prospective audit-and-feedback program in emergency general surgery service in a community hospital

Background

Prospective audit and feedback (PAF) is an established practice in critical care settings but not in surgical populations. We pilot-tested a structured face-to-face PAF program for our acute-care surgery (ACS) service.

Methods

This was a mixed-methods study. For the quantitative analysis, the structured PAF period was from August 1, 2017, to April 30, 2019. The ad hoc PAF period was from May 1, 2019, to January 31, 2021. Interrupted time-series segmented negative binomial regression analysis was used to evaluate change in antimicrobial usage measured in days of therapy per 1,000 patient days for all systemic and targeted antimicrobials. Secondary outcomes included C. difficile infections, length of stay and readmission within 30 days. Each secondary outcome was analyzed using a logistic regression or negative binomial regression model. For the qualitative analyses, all ACS surgeons and trainees from November 23, 2015, to April 30, 2019, were invited to participate in an email-based anonymous survey developed using implementation science principles. Responses were measured using counts.

Results

In total, 776 ACS patients were included in the structured PAF period and 783 patients were included in the in ad hoc PAF period. No significant changes in level or trend for antimicrobial usage were detected for all and targeted antimicrobials. Similarly, no significant differences were detected for secondary outcomes. The survey response rate was 25% (n = 10). Moreover, 50% agreed that PAF provided them with skills to use antimicrobials more judiciously, and 80% agreed that PAF improved the quality of antimicrobial treatment for their patients.

Conclusion

Structured PAF showed clinical outcomes similar to ad hoc PAF. Structured PAF was well received and was perceived as beneficial by surgical staff.

[Aloin inhibits gastric cancer cell proliferation and migration by suppressing the STAT3/HMGB1 signaling pathway]

OBJECTIVE

To investigate the molecular mechanism underlying the inhibitory effect of aloin on the proliferation and migration of gastric cancer cells.

METHODS

Human gastric cancer MGC-803 cells treated with 100, 200 and 300 μg/mL aloin were examined for changes in cell viability, proliferation and migration abilities using CCK-8, EdU and Transwell assays. HMGB1 mRNA level in the cells was detected with RT-qPCR, and the protein expressions of HMGB1, cyclin B1, cyclin E1, E-cadherin, MMP-2, MMP-9 and p-STAT3 were determined using Western blotting. JASPAR database was used to predict the binding of STAT3 to HMGB1 promoter. In a BALB/c-Nu mouse model bearing subcutaneous MGC-803 cell xenograft, the effect of intraperitoneal injection of aloin (50 mg/kg) on tumor growth was observed. The protein expressions of HMGB1, cyclin B1, cyclin E1, E-cadherin, MMP-2, MMP-9 and p-STAT3 in the tumor tissue was examined using Western blotting, and tumor metastasis in the liver and lung tissues was detected using HE staining.

RESULTS

Treatment with aloin concentration-dependently inhibited the viability of MGC-803 cells (P < 0.05), significantly reduced the number of EdU-positive cells (P < 0.01), and attenuated the migration ability of the cells (P < 0.01). Aloin treatment dose-dependently down-regulated HMGB1 mRNA expression (P < 0.01), lowered the protein expressions of HMGB1, cyclin B1, cyclin E1, MMP-2, MMP-9 and p-STAT3, and up-regulated E-cadherin expression in MGC-803 cells. Prediction based on JASPAR database suggested that STAT3 could bind to the promoter region of HMGB1. In the tumor-bearing mice, aloin treatment significantly reduced the tumor size and weight (P < 0.01), lowered the protein expressions of cyclin B1, cyclin E1, MMP-2, MMP-9, HMGB1 and p-STAT3 and increased the expression of E-cadherin in the tumor tissue (P < 0.01).

CONCLUSION

Aloin attenuates the proliferation and migration of gastric cancer cells by inhibiting the STAT3/HMGB1 signaling pathway.

Impact of extended-infusion piperacillin-tazobactam in a Canadian community hospital

BACKGROUND

Studies have demonstrated improved clinical outcomes with extended infusion (EI) piperacillin/tazobactam (TZP) compared to standard infusion (SI). However, there is less evidence on its benefits in noncritically-ill patients. Hospital-wide EI TZP was implemented at our site on February 21, 2012. Our objectives were to compare clinical, safety and economic outcomes between EI and SI TZP.

METHODS

A retrospective cohort study of all adult patients who received EI TZP (3.375 g IV q8h infused over 4 hours and SI TZP for ≥ 48 hours during 3 years pre-and postimplementation was conducted. The primary study outcome was 14-day mortality while secondary outcomes included length of hospital stay (LOS), nursing plus pharmacy cost, occurrence of Clostridioides difficile infection, readmission within 30 days and change in Pseudomonas aeruginosa minimum inhibitory concentration (MIC) distribution for TZP. The primary outcome and binary secondary outcomes were analyzed using a logistic regression model. LOS was examined using time to event analysis. Cost was examined using linear regression modelling.

RESULTS

Overall, 2034 patients received EI TZP and 1364 patients received SI TZP. EI TZP was associated with lower odds of mortality (OR 0.76, 95% CI 0.63-0.91), lower odds of C. difficile infection (OR 0.59, 95% CI 0.41-0.84) and 8% lower cost (estimate 0.92, 95% CI 0.87-0.98) compared to SI TZP.

CONCLUSIONS

Hospital-wide implementation of EI TZP was associated with lower odds of 14-day mortality and incidence of C. difficile infection with cost savings at our institution.

A dynamical graph-based feature extraction approach to enhance mental task classification in brain-computer interfaces

Graph theoretic approaches in analyzing spatiotemporal dynamics of brain activities are under-studied but could be very promising directions in developing effective brain-computer interfaces (BCIs). Many existing BCI systems use electroencephalogram (EEG) signals to record and decode human neural activities noninvasively. Often, however, the features extracted from the EEG signals ignore the topological information hidden in the EEG temporal dynamics. Moreover, existing graph theoretic approaches are mostly used to reveal the topological patterns of brain functional networks based on synchronization between signals from distinctive spatial regions, instead of interdependence between states at different timestamps. In this study, we present a robust fold-wise hyperparameter optimization framework utilizing a series of conventional graph-based measurements combined with spectral graph features and investigate its discriminative performance on classification of a designed mental task in 6 participants with amyotrophic lateral sclerosis (ALS). Across all of our participants, we reached an average accuracy of 71.1%±4.5% for mental task classification by combining the global graph-based measurements and the spectral graph features, higher than the conventional non-graph based feature performance (67.1%±7.5%). Compared to using either one of the graphic features (66.3%±6.5% for the eigenvalues and 65.9%±5.2% for the global graph features), our feature combination strategy shows considerable improvement in both accuracy and robustness performance. Our results indicate the feasibility and advantage of the presented fold-wise optimization framework utilizing graph-based features in BCI systems targeted at end-users.

[Epigenetic regulation mechanism: roles in enamel formation and developmental defects of enamel]

Enamel formation is a series of complex physiological processes, which are regulated by critical genes spatially and temporally. These processes involve multiple developmental stages covering ages and are prone to suffer signal interference or gene mutations, ultimately leading to developmental defects of enamel (DDE). Epigenetic modifications have important regulatory roles in gene expression during enarnel development. New technologies including high-throughput sequencing, chromatin immunoprecipitation sequencing (ChIP-seq), and DNA methylation chip are emerging in recent years, making it possible to establish genome-wide epigenetic modification profiles during developmental processes. The regulatory role of epigenetic modification with spatio-temporal pattern, such as DNA methylation, histone modification and non-coding RNA, has significantly expanded our understanding of the regulatory network of enamel formation, providing a new theoretical basis of clinical management and intervention strategy for DDE. The present review briefly describes the enamel formation process of human beings' teeth as well as rodent incisors and summarizes the dynamic characteristics of epigenetic modification during enamel formation. The functions of epigenetic modification in enamel formation and DDE are also emphatically discussed.

1772. Evaluating the Impact of a Pilot Structured Antimicrobial Stewardship Prospective Audit and Feedback Program in Emergency General Surgery in a Community Hospital

Background

The benefits of prospective audit and feedback (PAF) are established in critical care settings but not in the surgical population. We piloted once-weekly structured face-to-face PAF with the Acute Care Surgery (ACS) Service surgeon(s) and compared outcomes to usual care which comprised of ad-hoc PAF on targeted antimicrobials once or twice weekly with recommendations made to ACS surgeon(s) using written or verbal methods.

Methods

Interrupted time series segmented negative binomial regression analysis was used to evaluate the change in the primary outcome of antimicrobial usage measured in Days of Therapy/1000 patient days (DOT/1000-PD) for all systemic and targeted antimicrobials ordered by the ACS team. The structured PAF period was from August 1, 2017- April 30, 2019 while the ad-hoc PAF period was from May 1, 2019-January 31, 2021. Targeted antimicrobials included 3rd generation cephalosporins, piperacillin/tazobactam, carbapenems and clindamycin. Secondary outcomes included C. difficile infections, length of stay and readmission within 30 days. The first two secondary outcomes were analyzed using a logistic regression model while a negative binomial regression model was used to evaluate readmission within 30 days.

Results

There were 776 ACS patients in the structured PAF period with 783 patients in the ad-hoc PAF period. = No significant changes in level or trend of the primary outcome of DOT/1000-PD in both periods was found for all and targeted antimicrobials. However, there was a trend to small reduction in DOT/1000-PD of 0.9% per month (rate ratio 1.0, CI 0.99-1.02) for all antimicrobials and 0.3% per month (rate ratio 1.0, CI 0.98-1.03) for targeted antimicrobials in the ad-hoc PAF period. Similarly, there were no significant differences with respect to any of the secondary outcomes. There was a trend of 10% increase in length of stay (rate ratio 1.07, CI 0.98-1.17) and 13% reduction in 30-day readmission (OR 0.87, CI 0.56-1.35) in the ad-hoc PAF period.

Conclusion

Structured PAF showed similar clinical outcomes to ad-hoc PAF for the Acute Care Surgery Service at our institution. Other antimicrobial stewardship interventions can be explored to better support judicious antimicrobial use in General Surgery.

Disclosures

All Authors: No reported disclosures.

Trends in hospital antibiotic utilization during the coronavirus disease 2019 (COVID-19) pandemic: A multicenter interrupted time-series analysis

OBJECTIVE

To describe the evolution of respiratory antibiotic prescribing during the coronavirus disease 2019 (COVID-19) pandemic across 3 large hospitals that maintained antimicrobial stewardship services throughout the pandemic.

DESIGN

Retrospective interrupted time-series analysis.

SETTING

A multicenter study was conducted including medical and intensive care units (ICUs) from 3 hospitals within a Canadian epicenter for COVID-19.

METHODS

Interrupted time-series analysis was used to analyze rates of respiratory antibiotic utilization measured in days of therapy per 1,000 patient days (DOT/1,000 PD) in medical units and ICUs. Each of the first 3 waves of the pandemic were compared to the baseline.

RESULTS

Within the medical units, use of respiratory antibiotics increased during the first wave of the pandemic (rate ratio [RR], 1.76; 95% CI, 1.38-2.25) but returned to the baseline in waves 2 and 3 despite more COVID-19 admissions. In ICU, the use of respiratory antibiotics increased in wave 1 (RR, 1.30; 95% CI, 1.16-1.46) and wave 2 of the pandemic (RR, 1.21; 95% CI, 1.11-1.33) and returned to the baseline in the third wave, which had the most COVID-19 admissions.

CONCLUSIONS

After an initial surge in respiratory antibiotic prescribing, we observed the normalization of prescribing trends at 3 large hospitals throughout the COVID-19 pandemic. This trend may have been due to the timely generation of new research and guidelines developed with frontline clinicians, allowing for the active application of new research to clinical practice.

Approach to Strabismus

Strabismus is characterized by a misalignment of the eyes.  A thorough history and physical examination should be performed by clinicians when strabismus is suspected. The Hirschberg, cover, cover-uncover, and alternate prism cover tests are commonly used to identify and diagnose strabismus. Strabismus usually requires a referral to an ophthalmologist. Treatment of strabismus involves eye patches, cycloplegic drops, prescription glasses, and surgery. Strabismus can result in vision loss due to amblyopia and may also cause double vision, psychosocial concerns, and impaired depth perception.  

Evaluation of different antimicrobial stewardship models at a rehabilitation hospital: An interrupted time series (ITS) study

OBJECTIVE

To evaluate different prospective audit-and-feedback models on antimicrobial prescribing at a rehabilitation hospital.

DESIGN

Retrospective interrupted time series (ITS) and qualitative methods.

SETTING

A 178-bed rehabilitation hospital within an academic health sciences center.

METHODS

ITS analysis was used to analyze monthly days of therapy (DOT) per 1,000 patient days (PD) and monthly urine cultures ordered per 1,000 PD. We compared 2 sequential intervention periods to the baseline: (1) a period when a dedicated antimicrobial stewardship (AMS) pharmacist performed prospective audit and feedback and provided urine culture education followed by (2) a period when ward pharmacists performing audit and feedback. We conducted an electronic survey with physicians and semistructured interviews with pharmacists, respectively.

RESULTS

Audit and feedback conducted by an AMS pharmacist resulted in a 24.3% relative reduction in total DOT per 1,000 PD (incidence rate ratio [IRR], 0.76; 95% confidence interval [CI], 0.58-0.99; P = .04), whereas we detected no difference between ward pharmacist audit and feedback and the baseline (IRR, 1.20; 95% CI, 0.53-2.70; P = .65). We detected no statistically significant change in monthly urine-culture orders between the AMS pharmacist period and the baseline (level coefficient, 0.81; 95% CI, 0.65-1.01; P = .07). Compared to baseline, the ward pharmacist period showed a statistically significant increase in urine-culture ordering over time (slope coefficient, 1.04; 95% CI, 1.01-1.08; P = .02). The barrier most identified by pharmacists was insufficient time.

CONCLUSIONS

Audit and feedback conducted by an AMS pharmacist in a rehabilitation hospital was associated with decreased antimicrobial use.

Approach to Strabismus

Strabismus is characterized by a misalignment of the eyes.  A thorough history and physical examination should be performed by clinicians when strabismus is suspected. The Hirschberg, cover, cover-uncover, and alternate prism cover tests are commonly used to identify and diagnose strabismus. Strabismus usually requires a referral to an ophthalmologist. Treatment of strabismus involves eye patches, cycloplegic drops, prescription glasses, and surgery. Strabismus can result in vision loss due to amblyopia and may also cause double vision, psychosocial concerns, and impaired depth perception.  

Symptomatic and Asymptomatic Chronic Carotid Artery Occlusion on High-Resolution MR Vessel Wall Imaging

BACKGROUND AND PURPOSE

Chronic carotid artery occlusion remains a poorly understood risk factor for subsequent stroke, and potential revascularization is dependent on understanding the anatomy and nature of the occlusion. Luminal imaging cannot assess the nature of an occlusion, so the internal structure of the occlusion must be inferred. The present study examines the signal characteristics of symptomatic and asymptomatic carotid occlusion that may point to management differentiation.

MATERIALS AND METHODS

We prospectively recruited patients who were diagnosed with chronic carotid artery occlusion defined as longer than 4 weeks and confirmed by DSA. All patients underwent high-resolution MR vessel wall imaging examinations after enrollment. Baseline characteristics, vessel wall imaging features, and DSA features were collected and evaluated. The vessel wall imaging features included segment involvement, signal intensity, contrast enhancement, and vessel wall thickness. The symptomatic and asymptomatic chronic carotid artery occlusions were compared.

RESULTS

A total of 44 patients with 48 lesions were included in this study from February 2020 to December 2020. Of the 48 lesions, 35 (72.9%) were symptomatic and 13 (27.1%) were asymptomatic. There was no difference in baseline and DSA features. On vessel wall imaging, C1 and C2 were the most commonly involved segments (91.7% and 68.8%, respectively). Compared with symptomatic lesions, asymptomatic lesions were more often isointense (69.2%) in the distal segment (P = .03). Both groups had diffuse wall thickening (80% and 100%).

CONCLUSIONS

Signal characteristics between those with symptomatic and asymptomatic carotid artery occlusions differ in a statistically significant fashion, indicating a different structure of the occlusion.

MDA5 attenuate autophagy in chicken embryo fibroblasts infected with IBDV

1. The role of melanoma differentiation-associated protein 5 (MDA5) in infectious bursal disease virus (IBDV)-induced autophagy was studied in chicken embryos.2. Chicken embryo fibroblasts (CEF) were used as the research model and small interfering RNA (siRNA), western blot, indirect enzyme-linked immunosorbent assay (ELISA), real-time fluorescence quantitative polymerase chain reaction (PCR) and transmission electron microscopy were used to detect autophagy, IBDV replication, CEF damage, and activation of both MDA5 and its signalling pathway.3. The results showed that CEF infected with IBDV activated the intracellular MDA5 signalling pathway and caused autophagy via inactivation of the AKT/mTOR pathway. While autophagy promotes IBDV proliferation, MDA5 weakens IBDV-induced CEF autophagy thus inhibiting IBDV replication and protecting CEF cells.4. The results indicated that chMDA5 can be activated by IBDV and attenuate CEF autophagy caused by IBDV infection, thereby inhibiting IBDV replication. This study provided a foundation for further exploring the relationship between viruses, autophagy and the pathogenic mechanism of the MDA5 pathway involved in IBDV.

Bisphenol A Exposure Disrupts Enamel Formation via EZH2-Mediated H3K27me3

Enamel formation is a serial and complex biological process, during which related genes are expressed progressively in a spatiotemporal manner. This process is vulnerable to environmental cues, resulting in developmental defects of enamel (DDE). However, how environmental factors are biologically integrated during enamel formation is still poorly understood. Here, we investigated the mechanism of DDE elicited by a model endocrine-disrupting chemical, bisphenol A (BPA), in mouse incisors. We show that BPA exposure leads to DDE in mouse incisors, as well as excessive proliferation in dental epithelial stem/progenitor cells. Western blotting, chromatin immunoprecipitation sequencing, and immunofluorescence staining revealed that this effect was accompanied by upregulation of a repressive mark, H3K27me3, in the labial cervical loop of mouse incisors. Perturbation of H3K27me3 methyltransferase EZH2 repressed the level of H3K27me3 and partially attenuated the excessive proliferation in dental epithelial stem/progenitor cells and DDE induced by BPA exposure. Overall, our results demonstrate the essential role of repressive histone modification H3K27me3 in DDE elicited by exposure to an endocrine-disrupting chemical.

Prevalence and antimicrobial resistance of Salmonellaisolates from goose farms in Northeast China

BACKGROUND

Salmonella is one of the most important enteric pathogenic bacteria that threatened poultry health.

AIMS

This study aimed to investigate the prevalence and antimicrobial resistance of Salmonella isolates in goose farms.

METHODS

A total of 244 cloacal swabs were collected from goose farms to detect Salmonella in Northeast China. Antimicrobial susceptibility, and resistance gene distribution of Salmonella isolates were investigated.

RESULTS

Twenty-one Salmonella isolates were identified. Overall prevalence of Salmonella in the present study was 8.6%. Among the Salmonella isolates, the highest resistance frequencies belonged to amoxicillin (AMX) (85.7%), tetracycline (TET) and trimethoprim/sulfamethoxazole (SXT) (81%), followed by chloramphenicol (CHL) (76.2%), florfenicol (FLO) (71.4%), kanamycin (KAN) (47.6%), and gentamycin (GEN) (38.1%). Meanwhile, only 4.8% of the isolates were resistant to ciprofloxacin (CIP) and cefotaxime (CTX). None of the isolates was resistant to cefoperazone (CFP) and colistin B (CLB). Twenty isolates (95%) were simultaneously resistant to at least two antimicrobials. Ten resistance genes were detected among which the bla _TEM-1, cmlA, aac(6')-Ib-cr, sul1, sul2, sul3, and mcr-1.1 were the most prevalent, and presented in all 21 isolates followed by tetB (20/21), qnrB (19/21), and floR (15/21).

CONCLUSION

Results indicated that Salmonella isolates from goose farms in Northeast China exhibited multi-drug resistance (MDR), harboring multiple antimicrobial resistance genes. Our results will be useful to design prevention and therapeutic strategies against Salmonella infection in goose farms.

A randomized controlled trial protocol assessing the effectiveness, safety and cost-effectiveness of methotrexate vs. ciclosporin in the treatment of severe atopic eczema in children: the TREatment of severe Atopic eczema Trial (TREAT)

BACKGROUND

Oral systemic immunomodulatory medication is regularly used off-licence in children with severe atopic eczema. However, there is no firm evidence regarding the effectiveness, safety, cost-effectiveness and impact on quality of life from an adequately powered randomized controlled trial (RCT) using systemic medication in children.

OBJECTIVES

To assess whether there is a difference in the speed of onset, effectiveness, side-effect profile and reduction in flares post-treatment between ciclosporin (CyA) and methotrexate (MTX), and also the cost-effectiveness of the drugs. Treatment impact on quality of life will also be examined in addition to whether FLG genotype influences treatment response. In addition, the trial studies the immune-metabolic effects of CyA and MTX.

METHODS

Multicentre, parallel group, assessor-blind, pragmatic RCT of 36 weeks' duration with a 24-week follow-up period. In total, 102 children aged 2-16 years with moderate-to-severe atopic eczema, unresponsive to topical treatment will be randomized (1 : 1) to receive MTX (0·4 mg kg^-1 per week) or CyA (4 mg kg^-1 per day).

RESULTS

The trial has two primary outcomes: change from baseline to 12 weeks in Objective Severity Scoring of Atopic Dermatitis (o-SCORAD) and time to first significant flare following treatment cessation.

CONCLUSIONS

This trial addresses important therapeutic questions, highlighted in systematic reviews and treatment guidelines for atopic eczema. The trial design is pragmatic to reflect current clinical practice.

The impact of vancomycin trough concentrations on outcomes in non-deep seated infections: a retrospective cohort study

Background

Guidelines recommending vancomycin trough concentrations > 10 mg/L in non-deep seated infections are based on expert opinion. The objective of this study was to evaluate patients with non-deep seated infections treated with short-course vancomycin to determine whether there were differences in outcomes with trough concentrations of ≤10 mg/L (low) versus > 10 mg/L (high).

Methods

A retrospective cohort study of patients hospitalized between March 10, 2010 and December 31, 2015 who received ≤14 days of vancomycin to treat a non-deep seated infection and had at least one steady state trough concentration was completed. Patient data for the low versus high trough cohorts were compared using appropriate statistical tests and binary logistic regression was used to identify factors associated with clinical outcome.

Results

Of 2098 patients screened, 103 (5%) met inclusion criteria. Baseline characteristics between cohorts were not different. Clinical cure was not different between the low (42/48 [88%]) and high trough (48/55 [87%]) cohorts (p > 0.99) and vancomycin trough concentration was not associated with clinical outcome (p = 0.973). More patients in the high trough group had dosing changes (7/48 [15%] vs. 22/55 [40%], p = 0.0046), with approximately three times more dose adjustments per patient (0.17 vs. 0.55, p = 0.0193). No signal for increased vancomycin resistance associated with vancomycin troughs was identified.

Conclusions:

No difference in clinical or microbiological outcomes based on vancomycin trough concentrations were observed in patients with non-deep seated infections treated with vancomycin for ≤14 days. Targeting higher vancomycin trough concentrations of > 10 mg/L may be associated with increased workload with no corresponding benefit in clinical or microbiological outcomes in these patients.

Interpretation of liver stiffness measurement-based approach for the monitoring of hepatitis B patients with antiviral therapy: A 2-year prospective study

Liver biopsy is not routinely performed in treated chronic hepatitis B. Liver stiffness measurement has been validated for noninvasive liver fibrosis assessment in pretreatment chronic hepatitis B but has not been assessed for fibrosis monitoring during antiviral therapy. Liver stiffness was systemically monitored by Fibroscan^® every 6 months in a cohort of patients with hepatitis B receiving antiviral therapy and compared with liver biopsies at baseline and week 104. A total of 534 hepatitis B e antigen-positive treatment-naive patients receiving telbivudine-based therapy with qualified liver stiffness measurement at baseline and week 104 were analyzed, 164 of which had adequate paired liver biopsies. Liver stiffness decreased rapidly (-2.2 kPa/24 weeks) in parallel with alanine aminotransferase (ALT) from 8.6 (2.6-49.5) kPa at baseline to 6.1 (2.2-37.4) kPa at week 24. Interestingly, liver stiffness decreased slowly (-0.3 kPa/24 weeks) but continually from week 24 to week 104 (6.1 vs 5.3 kPa, P < .001) while ALT levels remained stable within the normal range. More importantly, liver stiffness declined significantly irrespective of baseline ALT levels and liver necroinflammation grades. From baseline to week 104, the proportion of patients with no or mild fibrosis (Ishak, 0-2) increased from 74.4% (122/164) to 93.9% (154/164). Multivariate analysis revealed that percentage decline of 52-week liver stiffness from baseline was independently associated with 104-week liver fibrosis regression (odds ratio, 3.742; P = .016). Early decline of 52-week liver stiffness from baseline may reflect the remission of both liver inflammation and fibrosis and was predictive of 104-week fibrosis regression in treated patients with chronic hepatitis B.

The incidence of military training-related injuries in Chinese new recruits: a systematic review and meta-analysis

INTRODUCTION

Training-related injuries are the main reason for disability, long-term rehabilitation, functional impairment and premature discharge from military service. The aim of this study was to identify the incidence of injuries in the training of Chinese new recruits via a systematic review of the literature.

METHOD

A systematic review and meta-analysis was conducted to evaluate the combined incidence of military training-related injuries in Chinese new recruits. The electronic databases of full-text journals were searched, and the Loney criteria were used to assess the quality of eligible articles. Summary estimates were obtained using random-effects models. Subgroup analyses and publication bias tests were performed.

RESULTS

Fifty-five eligible articles representing 109 611 Chinese new recruits met the inclusion criteria, of which 21 253 recruits were clinically diagnosed with military training-related injuries. The combined incidence of military training-related injuries in Chinese new recruits was found to be 21.04%.

CONCLUSIONS

An increased incidence of training injuries was found in more recent years, underscoring the need for further research on the risk factors associated with their causation.

Bivalent Histone Codes on WNT5A during Odontogenic Differentiation

Lineage-committed differentiation is an essential biological program during odontogenesis, which is tightly regulated by lineage-specific genes. Some of these genes are modified by colocalization of H3K4me3 and H3K27me3 marks at promoter regions in progenitors. These modifications, named "bivalent domains," maintain genes in a poised state and then resolve for later activation or repression during differentiation. Wnt5a has been reported to promote odontogenic differentiation in dental mesenchyme. However, relatively little is known about the epigenetic modulations on Wnt5a activation during tooth development. Here, we investigated the spatiotemporal patterns of H3K4me3 and H3K27me3 marks in developing mouse molars. Associated H3K4me3 methylases (mixed-lineage leukemia [MLL] complex) and H3K27me3 demethylases (JMJD3 and UTX) were dynamically expressed between early and late bell stage of human tooth germs and in cultured human dental papilla cells (hDPCs) during odontogenic induction. Poised WNT5A gene was marked by bivalent domains containing repressive marks (H3K27me3) and active marks (H3K4me3) on promoters. The bivalent domains tended to resolve during inducted differentiation, with removal of the H3K27me3 mark in a JMJD3-dependent manner. When JMJD3 was knocked down in cultured hDPCs, odontogenic differentiation was suppressed. The depletion of JMJD3 epigenetically repressed WNT5A activation by increased H3K27me3 marks. In addition, JMJD3 could physically interact with ASH2L, a component of the MLL complex, to form a coactivator complex, cooperatively modulating H3K4me3 marks on WNT5A promoters. Overall, our study reveals that transcription activities of WNT5A were epigenetically regulated by the negotiated balance between H3K27me3 and H3K4me3 marks and tightly mediated by JMJD3 and MLL coactivator complex, ultimately modulating odontogenic commitment during dental mesenchymal cell differentiation.

Energy transfer channels and turbulence cascade in Vlasov-Maxwell turbulence

Analysis of the Vlasov-Maxwell equations from the perspective of turbulence cascade clarifies the role of electromagnetic work, and reveals the importance of the pressure-strain relation in generating internal energy. Particle-in-cell simulation demonstrates the relative importance of the several energy exchange terms, indicating that the traceless pressure-strain interaction "Pi-D" is of particular importance for both electrons and protons. The Pi-D interaction and the second tensor invariants of the strain are highly localized in similar spatial regions, indicating that energy transfer occurs preferentially in coherent structures. The collisionless turbulence cascade may be fruitfully explored by study of these energy transfer channels, in addition to examining transfer across spatial scales.

Characterization of Extensive Microstructural Variations Associated with Punctate White Matter Lesions in Preterm Neonates

BACKGROUND AND PURPOSE

Punctate white matter lesions are common in preterm neonates. Neurodevelopmental outcomes of the neonates are related to the degree of extension. This study aimed to characterize the extent of microstructural variations for different punctate white matter lesion grades.

MATERIALS AND METHODS

Preterm neonates with punctate white matter lesions were divided into 3 grades (from mild to severe: grades I-III). DTI-derived fractional anisotropy, axial diffusivity, and radial diffusivity between patients with punctate white matter lesions and controls were compared with Tract-Based Spatial Statistics and tract-quantification methods.

RESULTS

Thirty-three preterm neonates with punctate white matter lesions and 33 matched controls were enrolled. There were 15, 9, and 9 patients, respectively, in grades I, II, and III. Punctate white matter lesions were mainly located in white matter adjacent to the lateral ventricles, especially regions lateral to the trigone, posterior horns, and centrum semiovale and/or corona radiata. Extensive microstructural changes were observed in neonates with grade III punctate white matter lesions, while no significant changes in DTI metrics were found for grades I and II. A pattern of increased axial diffusivity, increased radial diffusivity, and reduced/unchanged fractional anisotropy was found in regions adjacent to punctate white matter lesion sites seen on T1WI and T2WI. Unchanged axial diffusivity, increased radial diffusivity, and reduced/unchanged fractional anisotropy were observed in regions distant from punctate white matter lesion sites.

CONCLUSIONS

White matter microstructural variations were different across punctate white matter lesion grades. Extensive change patterns varied according to the distance to the lesion sites in neonates with severe punctate white matter lesions. These findings may help in determining the outcomes of punctate white matter lesions and selecting treatment strategies.

Influencing antiemetic prescribing practices and funding changes through evidence-based guidelines

31

Background: In 2013 Cancer Care Ontario released updated antiemetic recommendations supporting the use of aprepitant-based combinations as 1st line therapy for highly emetogenic and 2nd line therapy for moderately emetogenic chemotherapy and discouraging the prolonged use of 5-HT3 antagonists. In 2014 changes were made in the Ontario drug formulary to align public funding to those recommendations. The impact of the changes in guidance and public funding on prescribing practices are now being analyzed. Methods: Using the Ontario Drug Benefit (ODB) database, data was extracted to analyze the prescribing practices of aprepitant, granisetron and ondansetron for chemotherapy-induced emesis between the pre-funding period (November 2013 to September 2014) and post-funding period (October 2014 to July 2015). Results: Prior to funding changes, an average of 197 prescriptions/month of aprepitant were billed to the ODB program totaling $22,422. After funding, an average of 1,165 prescriptions/month of aprepitant were billed totaling $132,145. This represented a 490% increase in utilization. The combined 5-HT3 receptor antagonists prescriptions/month billed during the respective time periods were 5,592 ($405,604) and 5,536 ($402,628). This represented a 1% decrease in utilization. Conclusions: There was a significant increase in aprepitant utilization and total expenditure to the ODB program indicating strong uptake of the triple-drug recommendation for highly emetogenic regimens. However, there was minimal change in prescribing practices related to the 5-HT3 receptor antagonists, indicating a reluctance to decrease utilization. Further work is necessary to discourage the prolonged use of 5-HT3 receptor antagonists.

E-selectin expression induced by Porphyromonas gingivalis in human endothelial cells via nucleotide-binding oligomerization domain-like receptors and Toll-like receptors

Porphyromonas gingivalis, an important periodontal pathogen, has been proved to actively invade cells, induce endothelial cell activation, and promote development of atherosclerosis. Innate immune surveillance, which includes the activity of nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) and Toll-like receptors (TLRs), are essential for the control of microbial infections; however, the roles of receptor families in P. gingivalis infections remain unclear. Here, we examined the roles of NLRs and TLRs in endothelial cell activation caused by P. gingivalis. Live P. gingivalis and whole cell sonicates were used to stimulate endothelial cells, and both showed upregulation of E-selectin as well as NOD1, NOD2, and TLR2. In addition, silencing of these genes in endothelial cells infected with P. gingivalis led to a reduction in E-selectin expression. Porphyromonas gingivalis also induced nuclear factor-κB (NF-κB) and P38 mitogen-activated protein kinase (MAPK) activity in endothelial cells, whereas small interfering RNA targeting NOD1 significantly reduced these signals. Moreover, inhibition of either NOD2 or TLR2 inhibited NF-κB significantly, but had only a weak inhibitory effect on P38 MAPK signaling. Direct inhibition of NF-κB and P38 MAPK significantly attenuated E-selectin expression induced by P. gingivalis in endothelial cells. Taken together, these findings suggest that NOD1, NOD2, and TLR2 play important, non-redundant roles in endothelial cell activation following P. gingivalis infection.

Anisotropy in solar wind plasma turbulence

A review of spectral anisotropy and variance anisotropy for solar wind fluctuations is given, with the discussion covering inertial range and dissipation range scales. For the inertial range, theory, simulations and observations are more or less in accord, in that fluctuation energy is found to be primarily in modes with quasi-perpendicular wavevectors (relative to a suitably defined mean magnetic field), and also that most of the fluctuation energy is in the vector components transverse to the mean field. Energy transfer in the parallel direction and the energy levels in the parallel components are both relatively weak. In the dissipation range, observations indicate that variance anisotropy tends to decrease towards isotropic levels as the electron gyroradius is approached; spectral anisotropy results are mixed. Evidence for and against wave interpretations and turbulence interpretations of these features will be discussed. We also present new simulation results concerning evolution of variance anisotropy for different classes of initial conditions, each with typical background solar wind parameters.

Intermittent Dissipation and Heating in 3D Kinetic Plasma Turbulence

High resolution, fully kinetic, three dimensional (3D) simulation of collisionless plasma turbulence shows the development of turbulence characterized by sheetlike current density structures spanning a range of scales. The nonlinear evolution is initialized with a long wavelength isotropic spectrum of fluctuations having polarizations transverse to an imposed mean magnetic field. We present evidence that these current sheet structures are sites for heating and dissipation, and that stronger currents signify higher dissipation rates. The analyses focus on quantities such as J·E, electron, and proton temperatures, and conditional averages of these quantities based on local electric current density. Evidently, kinetic scale plasma, like magnetohydrodynamics, becomes intermittent due to current sheet formation, leading to the expectation that heating and dissipation in astrophysical and space plasmas may be highly nonuniform. Comparison with previous results from 2D kinetic simulations, as well as high frequency solar wind observational data, are discussed.

Crosstalk between miR-34a and Notch Signaling Promotes Differentiation in Apical Papilla Stem Cells (SCAPs)

Stem cells from the apical papilla (SCAPs) are important for the formation and regeneration of root dentin. Here, we examined the expression of Notch signaling components in SCAPs and investigated crosstalk between microRNA miR-34aand Notch signaling during cell differentiation. We found that human SCAPs express NOTCH2, NOTCH3, JAG2, DLL3, and HES1, and we tested the relationship between Notch signaling and both cell differentiation and miR-34a expression. NOTCH activation in SCAPs inhibited cell differentiation and up-regulated the expression of miR-34a, whereas miR-34a inhibited Notch signaling in SCAPs by directly targeting the 3'UTR of NOTCH2 and HES1 mRNA and suppressing the expression of NOTCH2, N2ICD, and HES1. DSPP, RUNX2, OSX, and OCN expression was consequently up-regulated. Thus, Notch signaling in human SCAPs plays a vital role in maintenance of these cells. miR-34a interacts with Notch signaling and promotes both odontogenic and osteogenic differentiation of SCAPs.

Von Kármán energy decay and heating of protons and electrons in a kinetic turbulent plasma

Decay in time of undriven weakly collisional kinetic plasma turbulence in systems large compared to the ion kinetic scales is investigated using fully electromagnetic particle-in-cell simulations initiated with transverse flow and magnetic disturbances, constant density, and a strong guide field. The observed energy decay is consistent with the von Kármán hypothesis of similarity decay, in a formulation adapted to magnetohydrodyamics. Kinetic dissipation occurs at small scales, but the overall rate is apparently controlled by large scale dynamics. At small turbulence amplitudes the electrons are preferentially heated. At larger amplitudes proton heating is the dominant effect. In the solar wind and corona the protons are typically hotter, suggesting that these natural systems are in the large amplitude turbulence regime.

Efficacy and safety of continuous 4-year telbivudine treatment in patients with chronic hepatitis B

In the phase-III GLOBE/015 studies, telbivudine demonstrated superior efficacy vs lamivudine during 2-year treatment in HBeAg-positive and HBeAg-negative chronic hepatitis B (CHB). After completion, 847 patients had an option to continue telbivudine treatment for further 2 years. A total of 596 (70%) of telbivudine-treated patients, who were serum HBV DNA positive or negative and without genotypic resistance to telbivudine at the end of the GLOBE/015 trials, were enrolled into a further 2-year extension study. A group of 502 patients completed 4 years of continuous telbivudine treatment and were included in the telbivudine per-protocol population. Amongst 293 HBeAg-positive patients, 76.2% had undetectable serum HBV DNA and 86.0% had normal serum ALT at the end of 4 years. Notably, the cumulative rate of HBeAg seroconversion was 53.2%. Amongst 209 HBeAg-negative patients, 86.4% had undetectable HBV DNA and 89.6% had normal serum ALT. In patients who had discontinued telbivudine treatment due to HBeAg seroconversion, the HBeAg response was durable in 82% of patients (median 111 weeks of off-treatment follow-up). The cumulative 4-year resistance rate was 10.6% for HBeAg-positive and 10.0% for HBeAg-negative patients. Most adverse events were mild or moderate in severity and transient. Renal function measured by estimated glomerular filtration rate (eGFR) increased by 14.9 mL/min/1.73 m(2) (16.6%) from baseline to 4 years (P < 0.0001). In conclusion, in HBeAg-positive and HBeAg-negative CHB patients without resistance after 2 years, two additional years of telbivudine treatment continued to provide effective viral suppression with a favourable safety profile. Moreover, telbivudine achieved 53% of HBeAg seroconversion in HBeAg-positive patients.

Intermittent dissipation at kinetic scales in collisionless plasma turbulence

High resolution kinetic simulations of collisionless plasma driven by shear show the development of turbulence characterized by dynamic coherent sheetlike current density structures spanning a range of scales down to electron scales. We present evidence that these structures are sites for heating and dissipation, and that stronger current structures signify higher dissipation rates. Evidently, kinetic scale plasma, like magnetohydrodynamics, becomes intermittent due to current sheet formation, leading to the expectation that heating and dissipation in astrophysical and space plasmas may be highly nonuniform and patchy.

3 distinct regions of chromosome-6 are targets of loss of heterozygosity in human ovarian carcinomas

We performed mapping studies of allelic deletions on chromosome 6 in 52 ovarian carcinomas using 20 polymorphic markers assigned to various regions of both chromosomal arms. Loss of heterozygosity was seen in 28 (55%) tumors. The allelic losses, however, did not involve the whole chromosome in 18 of those tumors, allowing further localization of the targeted chromosomal region(s). Three different chromosomal regions appeared involved based on the distribution of partial deletions, 2 on the long arm and one on the short arm. One of the 2 regions on the long arm was confined to band 6q27 whereas the other was between the Arg1 and estrogen receptor loci. The targeted region on the short arm was bounded by the D6S89 and D6S248 loci. These results suggest the presence of at least 3 different tumor suppressor genes important for the control of ovarian tumorigenesis on chromosome 6.

Overexpression of activin A inhibits growth, induces apoptosis, and suppresses tumorigenicity in an androgen-sensitive human prostate cancer cell line LNCaP

The effects of overexpression of activin A in the androgen-sensitive human prostate cancer cell line LNCaP were studied. A full-length cDNA of activin beta A coding region was inserted into a eukaryotic expression vector and transfected into the LNCaP cells. Overexpression of activin BA significantly inhibited growth of this cell line. An increased death rate was also noted in these activin-overproducing cells, which was believed to be due to apoptosis as manifested by morphological change, DNA laddering, and FAGS analysis. The expression of bcl-2 was suppressed and the expression of c-myc was stimulated in these cells. In addition, the efficiency of soft agar colony formation and the tumorigenicity in the nude mice were suppressed for the activin producing LNCaP cells.

Intermittency and local heating in the solar wind

Evidence for nonuniform heating in the solar wind plasma near current sheets dynamically generated by magnetohydrodynamic (MHD) turbulence is obtained using measurements from the ACE spacecraft. These coherent structures only constitute 19% of the data, but contribute 50% of the total plasma internal energy. Intermittent heating manifests as elevations in proton temperature near current sheets, resulting in regional heating and temperature enhancements extending over several hours. The number density of non-Gaussian structures is found to be proportional to the mean proton temperature and solar wind speed. These results suggest magnetofluid turbulence drives intermittent dissipation through a hierarchy of coherent structures, which collectively could be a significant source of coronal and solar wind heating.

Anisotropic third-moment estimates of the energy cascade in solar wind turbulence using multispacecraft data

The first direct determination of the inertial range energy cascade rate, using an anisotropic form of Yaglom's law for magnetohydrodynamic turbulence, is obtained in the solar wind with multispacecraft measurements. The two-point mixed third-order structure functions of Elsässer fluctuations are integrated over a sphere in magnetic field-aligned coordinates, and the result is consistent with a linear scaling. Therefore, volume integrated heating and cascade rates are obtained that, unlike previous studies, make only limited assumptions about the underlying spectral geometry of solar wind turbulence. These results confirm the turbulent nature of magnetic and velocity field fluctuations in the low frequency limit, and could supply the energy necessary to account for the nonadiabatic heating of the solar wind.