Electromagnetic Actuation System for Focused Capturing of Magnetic Particles With a Half of Static Saddle Potential Energy Configuration

Targeted drug delivery using magnetic particles (MPs) and external magnets for focusing them at the diseased regions, called magnetic drug targeting (MDT), is a next-generation therapeutic method that is being continually improved. However, most existing magnetic systems cannot focus MPs in the targeted region due to there not being enough magnetic capturing force and absence of schemes to generate localized high magnetic field at the wall of the target region. This paper suggests a novel scheme to utilize half of a static saddle potential energy configuration generated using four electromagnets that not only enhances the pushing magnetic forces but also simultaneously generates pushing and attracting forces in the desired direction to help focus spherical MPs on the wall of the target region. Furthermore, by changing amplitudes or directions of the currents, the focal point in the target region can be changed. Through extensive simulations and in vitro experiments, we demonstrate that half of a static saddle magnetic potential energy configuration can be successfully utilized to attract and focus MPs at the wall of a target region.

Inhibitory effect of alpha-lipoic acid on mitochondrial dysfunction and interleukin-8 expression in interleukin-1beta-stimulated ataxia teleangiectasia fibroblasts

Ataxia telangiectasia (A-T) is an inherited neurodegenerative disease caused by mutation in the ataxia telangiectasia mutated (ATM) gene, leading to loss of function in the encoded protein ATM. Because ATM functions to reduce oxidative stress by up-regulating antioxidant enzymes, oxidative stress is a prevalent A-T phenotype and a mediator of the inflammation that drives A-T pathology. Reactive oxygen species (ROS) levels and the expression of pro-inflammatory cytokine interleukin-8 (IL-8) were higher in A-T cells than in normal cells. ROS are related to mitochondrial dysfunction and activation of nuclear factor kappa B (NF-κB) to induce IL-8 expression. Alpha-lipoic acid (α-LA), a naturally occurring thiol compound, shows an antioxidant effect in various cells. This study is aimed to determine if α-LA confers protection against NF-κB activation, IL-8 expression, and mitochondrial dysfunction in A-T cells which are exposed to the inflammatory cytokine IL-1β. A-T fibroblasts were treated with or without α-LA. The levels of intracellular and mitochondrial ROS, mRNA and protein levels of IL-8, mitochondrial membrane potential (MMP), ATP levels, and DNA binding activity of NF-κB were determined. As a result, IL-1β increased NF-κB activation, IL-8 expression, intracellular and mitochondrial ROS levels, but decreased MMP and ATP level in A-T cells. Pretreatment of A-T cells with α-LA inhibited IL-1β-induced activation of NF-κB, IL-8 expression, and mitochondrial dysfunction by reducing ROS levels. In conclusion, supplementation with α-LA may be beneficial for reducing the oxidative stress-induced mitochondrial dysfunction and IL-8 production associated with A-T.

AB1121 IMPLEMENTING HIGH VALUE CARE IN INPATIENT ANTINUCLEAR ANTIBODY TESTING

Background:

Antinuclear Antibody (ANA) testing forms the basis on which many rheumatological diseases are subsequently diagnosed. ANA testing quantifies the dilution of plasma to produce the titer and staining pattern and this can be a part of an ANA order set that reflexively cascades to sub-serology if positive. Studies have shown that a low titer ANA may potentially translate into an erroneous diagnosis: if one estimates a 1 percent prevalence of ANA associated disease in the general population then 30% of those individuals would have a false positive result of ANA detected at 1:40 titer [1]. We theorized that there is no need for several methods to coexist within a single inpatient hospital setting especially since diagnostic value of staining patterns alone is limited.

Objectives:

To compare the utility and yield of “ANA screening reflex to profile” (ARP) and “ANA reflex to titer” (ART) order sets in the inpatient setting of a community tertiary care hospital. We aim to identify the appropriateness of the ANA testing ordered including cost-effectiveness of ordering ARP over ART in order to implement the identified quality measures towards improving utilization of ANA testing.

Methods:

We identified all inpatient ANA reflex testing orders performed at Community Regional Medical Center, Fresno, California completed between 11/2018 till 07/2019. This included ART and ARP orders with 6 sub-serologies: SSA, SSB, dsDNA, Smith, Scl-70 and U1RNP. A Health Information Management report was generated which included patient’s age, gender, length of hospital stay, dates of testing ordered, principal diagnosis and type of ANA testing ordered. Descriptive statistics were computed and analyzed.

Results:

We reviewed a total of 1,012 ANA lab orders performed between 11/01/2018 until 07/30/2019 performed on 700 patients. According to the laboratory standard using Immunofluorescence Assay, an ANA titer starting from 1:40 is reported as positive. Out of the 1,012 tests, 334 tests were positive i.e. 33%. The ART order by itself contributed to 29.9% of the positive testing while ARP formed 70% of the positive testing. 56 of the 910 ARP (6%) performed had one or more sub-serology antibody positive while in 178 ARP orders (20%) only the ANA titer was positive with negative serology. The most common sub-serology antibody noted positive was dsDNA forming 54% of the positive serology results. Multiple testing was noted with 218 orders of ARP and ART being ordered on the same patient within the same week, which shows 21.5% of ANA lab orders were repetitive. Length of stay was noted to be more than 3 days for 89% of the patients who had repetitive testing, majority of those tests (99%) on the same day by the same medical provider. It cost $5.0 for an ART order that resulted negative and $5.0 for an ARP panel that resulted negative. It cost $10.0 for those patients who had both ART and ARP ordered with negative results. A positive ART result added $12.0 additional to the cost of each positive ANA profile ($67.36) when both tests were ordered together.

Conclusion:

Our study findings reflect the need for using higher yield ANA testing that has been standardized. It demonstrated that physicians ordering the testing were not familiar with the ART vs. ARP, and the laboratory orders needed to be re-structured. We removed the ART from the inpatient Electronic Medical Record i.e. Epic system so that only the ARP order remained. This would prevent repetitive testing and reduce healthcare costs through reduction by at least $12.0 per positive ANA result and may also translate into reduced length of hospital stay. We were able to add Centromere Antibody (Ab) to the ANA profile sub serologies to standardize it further as it is an important part of Scleroderma diagnosis.

References:

[1]Range of antinuclear antibodies in “healthy” individuals. AU, Tan EM, et al. Arthritis Rheum. 1997; 40(9):1601

Disclosure of Interests:

None declared

1026. Ertapenem Use During Antibiotic Stewardship Interventions in Community Hospitals

Background

Antimicrobial stewardship programs (ASP) promote the judicious use of antimicrobials to reduce antimicrobial resistance and improve patient outcomes. In our institution, we identified the overutilization of ertapenem and implemented several interventions to decrease its usage. The objective of this study was to assess the impact of these interventions on ertapenem use, rates of surgical site infection (SSI), carbapenem-resistant Enterobacteriaceae (CRE), and hospital-onset Clostridioides difficile infection.

Methods

This was a retrospective study conducted in 3 community hospitals in Iowa and Illinois using surveillance of anonymized antibiotic and infection control data from 2015 to 2018. Target ASP interventions included a daily retrospective review of ertapenem use, alternative alerts to providers through electronic health records (EHR), carbapenem restriction to infectious disease (ID) providers, and educational meetings with high-use provider groups. The primary outcome was the usage trend of ertapenem, and secondary outcomes were rates of SSI, CRE, and hospital-onset C. difficile infection. Interrupted time series analysis was performed to assess changes in the rates over the study period.

Results

An overall significant reduction in ertapenem use was observed in all 3-community hospitals from 2015 to 2018. Ertapenem days of therapy adjusted for case-mix index per 1000 patient-days was 11.2 in 2015 and 2.05 in 2018. Two breakpoints were identified; the addition of an ID trained pharmacist to the ASP (10/2016) and educational meetings with colorectal surgeons (5/2017). No significant difference was seen for hospital-onset C. difficile infection, SSI, or CRE. Purchase costs decreased for ertapenem by 81% in 2018 compared with 2015(P < 0.001).

Conclusion

Adding an ID trained pharmacist to an ASP decreased usage of ertapenem. The majority of ertapenem use was for surgical prophylaxis, and our data suggested that educational meetings with a high-usage group were effective. Surgical site infection rates did not increase when narrower spectrum surgical prophylaxis was used. Overall hospital-acquired C. difficile rate was unchanged, possibly due to alternative antibiotic use. Our study suggests ASP interventions can be cost saving.

Disclosures

All authors: No reported disclosures.

P6419Machine learning in critical care: the role of diabetes and age in acute coronary syndromes

Background

Patients with diabetes and non-ST elevation acute coronary syndrome (NSTE-ACS) have an increased risk of mortality and adverse outcomes following percutaneous coronary intervention (PCI).

Purpose

We aimed to investigate the impact of early, within 24 hours PCI compared with only routine medical treatment on clinical outcomes in a large international cohort of patients with NSTE-ACS and diabetes.

Methods

We identified 1,250 patients with diabetes and NSTE-ACS from a registry-based population between October 2010 and April 2016. The primary endpoint was 30-day all-cause mortality. The secondary endpoint was the composite outcome of 30-day all-cause mortality and left ventricular dysfunction (ejection fraction <40%). We undertook analyses to explore the heterogeneity of treatment effects using meta-classification (MC) algorithms followed by propensity score matching and inverse-probability-of-treatment weighting (IPTW) from a landmark of 24 hours from hospitalization.

Results

Of 1,250 NSTE-ACS first-day survivors with diabetes (median age 67 years; 59%, men), 470 (37.6%) received early PCI and 780 routine medical treatment. The overall 30-day all-cause mortality rates were higher in the routine medical treatment than the early PCI group (6.3% vs. 2.5%). The prediction results of the MC algorithms accounted for only one interaction term that was statistically significant: age ≥65 years. After propensity-matched analysis as well as IPTW, early PCI was associated with reduced 30-day all-cause mortality in the older age (OR: 0.35; 95% CI: 0.14 to 0.92 and 0.43; 95% CI: 0.21 to 0.86, respectively), whereas younger age had no association with the primary endpoint. Similar results were also obtained for the secondary endpoint.

Conclusions

Among patients with diabetes hospitalized for NSTE-ACS, an early, within 24 hours, PCI strategy is associated with reduced odds of 30-day mortality only for patients aged 65 years or over. MC algorithms provide accurate identification of treatment effect modifiers.

Effects of Vibrotactile Biofeedback Coding Schemes on Gait Symmetry Training of Individuals With Stroke

Variations in biofeedback coding schemes for postural control, in recent research, have shown significant differences in performance outcomes due to variations in coding schemes. However, the application of vibrotactile biofeedback coding schemes to gait symmetry training is not well explored. In this paper, we devised various vibrotactile biofeedback modes and identified their efficacy during gait symmetry training of individuals suffering from hemiparesis due to stroke. These modes are composed of variations in vibration type (on-time or intensity), and relation type (proportional or inversely-proportional) with the error in symmetry ratio. Eight individuals with stroke participated in walking trials. From dependent t-tests on the collected data, we found improved achievement of temporal gait symmetry while utilizing all the provided biofeedback modes compared to no biofeedback (P < 0.001). Furthermore, two-way repeated measures ANOVA revealed statistically significant difference in symmetry ratio for main effect of vibration type (P-value = 0.016, partial eta squared = 0.585). The participants performed better with modes of biofeedback with varying vibration on-times. Furthermore, participants showed better performance when the biofeedback varied proportionally with the error. These findings suggest that biofeedback coding schemes may have a significant effect on the performance of gait training.

CT features of extrahepatic arterioportal fistula in two cats

Two cats presented with large volume ascites and the cause was suspected to be portal hypertension. On contrast CT they both showed enhancement of the main portal vein during the arterial phase and an anomalous connection between the celiac artery and extrahepatic portal vasculature, prompting a diagnosis of extrahepatic arterioportal fistula. An extrahepatic arterioportal fistula is a connection between any artery and the portal vein outside the liver and, to our knowledge, this is the first report in cats.