Predicting posttraumatic epilepsy using admission electroencephalography after severe traumatic brain injury

OBJECTIVE

Posttraumatic epilepsy (PTE) develops in as many as one third of severe traumatic brain injury (TBI) patients, often years after injury. Analysis of early electroencephalographic (EEG) features, by both standardized visual interpretation (viEEG) and quantitative EEG (qEEG) analysis, may aid early identification of patients at high risk for PTE.

METHODS

We performed a case-control study using a prospective database of severe TBI patients treated at a single center from 2011 to 2018. We identified patients who survived 2 years postinjury and matched patients with PTE to those without using age and admission Glasgow Coma Scale score. A neuropsychologist recorded outcomes at 1 year using the Expanded Glasgow Outcomes Scale (GOSE). All patients underwent continuous EEG for 3-5 days. A board-certified epileptologist, blinded to outcomes, described viEEG features using standardized descriptions. We extracted 14 qEEG features from an early 5-min epoch, described them using qualitative statistics, then developed two multivariable models to predict long-term risk of PTE (random forest and logistic regression).

RESULTS

We identified 27 patients with and 35 without PTE. GOSE scores were similar at 1 year (p = .93). The median time to onset of PTE was 7.2 months posttrauma (interquartile range = 2.2-22.2 months). None of the viEEG features was different between the groups. On qEEG, the PTE cohort had higher spectral power in the delta frequencies, more power variance in the delta and theta frequencies, and higher peak envelope (all p < .01). Using random forest, combining qEEG and clinical features produced an area under the curve of .76. Using logistic regression, increases in the delta:theta power ratio (odds ratio [OR] = 1.3, p < .01) and peak envelope (OR = 1.1, p < .01) predicted risk for PTE.

SIGNIFICANCE

In a cohort of severe TBI patients, acute phase EEG features may predict PTE. Predictive models, as applied to this study, may help identify patients at high risk for PTE, assist early clinical management, and guide patient selection for clinical trials.

43 REDUCED KIDNEY FUNCTION IS ASSOCIATED WITH POORER GLOBAL AND DOMAIN-SPECIFIC COGNITIVE PERFORMANCE IN COMMUNITY-DWELLING OLDER ADULTS

Background

Chronic Kidney Disease (CKD) is an important risk factor in the development of cognitive impairment. However, the association between reduced estimated Glomerular Filtration Rate (eGFR) and performance on domain-specific cognitive and neuropsychological assessments is less clear and may represent an important target in the promotion of optimal brain health in older adults.

Methods

Participants from the Trinity, Ulster and Department of Agriculture cohort study underwent detailed assessment of cognitive and neuropsychological function using the Mini-Mental State Examination (MMSE), Frontal Assessment Battery (FAB) and Repeatable Battery for Assessment of Neuropsychological Status (RBANS). Mixed-effects Poisson and linear regression was used to assess the relationship between eGFR strata and cognitive/neuropsychological test performance.

Results

4,887 participants were included (73.94 ± 8.25 years; 67.7% female). Reduced eGFR was associated with poorer performance on all three cognitive assessments, most pronounced in those with eGFR &lt;45 mL/mL/1.73m2 (IRR: 1.19; 95% CI: 1.09, 1.29; p &lt; 0.001 for MMSE/IRR: 1.14; 95% CI 1.04, 1.24; p &lt; 0.001 for the FAB/β: -3.23; 95% CI -5.18, −1.30; p = 0.001 for RBANS, fully adjusted). Reduced eGFR was associated with poorer performance on immediate memory, visual–spatial and attention RBANS domains. Associations were strongest in the youngest old (&lt;70 years) with no association observed in those aged &gt;80 years.

Conclusion

Reduced kidney function was associated with poorer global and domain-specific function in community-dwelling older adults. Associations were strongest for those with eGFR &lt;45 mL/min/1.73m2 and the youngest-old, suggesting that this group may be most at risk and may benefit from potential preventative interventions.

Identification of IgG1 isotype phosphorylcholine antibodies for the treatment of inflammatory cardiovascular diseases

BACKGROUND

Phosphorylcholine (PC) is an important pro-inflammatory damage-associated molecular pattern. Previous data have shown that natural IgM anti-PC protects against cardiovascular disease. We aimed to develop a monoclonal PC IgG antibody with anti-inflammatory and anti-atherosclerotic properties.

METHODS

Using various techniques PC antibodies were validated and optimized. In vivo testing was performed in a femoral artery cuff model in ApoE3*Leiden mice. Safety studies are performed in rats and cynomolgus monkeys.

RESULTS

A chimeric anti-PC (PC-mAb(T15), consisting of a human IgG1 Fc and a mouse T15/E06 Fab) was produced, and this was shown to bind specifically to epitopes in human atherosclerotic tissues. The cuff model results in rapid induction of inflammatory genes and altered expression of genes associated with ER stress and choline metabolism in the lesions. Treatment with PC-mAb(T15) reduced accelerated atherosclerosis via reduced expression of endoplasmic reticulum stress markers and CCL2 production. Recombinant anti-PC Fab fragments were identified by phage display and cloned into fully human IgG1 backbones creating a human monoclonal IgG1 anti-PC (PC-mAbs) that specifically bind PC, apoptotic cells and oxLDL. Based on preventing macrophage oxLDL uptake and CCL2 production, four monoclonal PC-mAbs were selected, which to various extent reduced vascular inflammation and lesion development. Additional optimization and validation of two PC-mAb antibodies resulted in selection of PC-mAb X19-A05, which inhibited accelerated atherosclerosis. Clinical grade production of this antibody (ATH3G10) significantly attenuated vascular inflammation and accelerated atherosclerosis and was tolerated in safety studies in rats and cynomolgus monkeys.

CONCLUSIONS

Chimeric anti-PCs can prevent accelerated atherosclerosis by inhibiting vascular inflammation directly and through reduced macrophage oxLDL uptake resulting in decreased lesions. PC-mAb represents a novel strategy for cardiovascular disease prevention.

488. SARS-CoV-2 Preparedness among Community Hospitals in Southeastern United States

Background

The SARS-CoV-2 pandemic has placed a tremendous strain on the U.S. healthcare system leading to personal protective equipment (PPE) and resource shortages. Hospitals have developed contingency and crisis capacity strategies to optimize the use of resources, but, to date, community hospital preparedness has not been described.

Methods

We performed a cross-sectional survey of infection preventionists in 60 community hospitals within the Duke Infection Control Outreach Network between April 22 and May 7, 2020 using Qualtrics. The survey included 13 questions related to resource availability, crisis capacity strategies and approaches to testing.

Results

We received 50 responses during the study period with a response rate of 83%. Community hospitals reported varying degrees of PPE shortages (Table 1); 80% of community hospitals were implementing strategies to extend and reuse N95 respirators, Powered Air-Purifying Respirators, face shields and face masks. Over 70% of facilities reported reprocessing N95 respirators (Figure 1). Almost all facilities reported universal masking at time of this survey with 90% performing daily employee screening at point of entry. Additionally, 8% of facilities restarted elective procedures at the time of this survey, but only 54% of facilities reported that they were performing preoperative testing for SARS-CoV-2. Thirty-seven percent of facilities performed one SARS-CoV-2 test before discharging an asymptomatic patient to skilled nursing facility, while 43% of facilities performed 2 tests.

Table 1- Supply of Personal Protective Equipment and other resources in 50 community hospitals in southeastern United States

Figure 1: Different methods of reprocessing N95 respirators by 50 community hospitals in southeastern United States

Conclusion

Our findings reveal differences in resource availability, crisis capacity strategies and testing approaches used by community hospitals in preparation for the SARS-COV-2 pandemic. Lack of harmonization in approaches may be in part due to differences in state guidelines and decentralized federal approach to SARS-CoV-2 preparedness.

Disclosures

All Authors: No reported disclosures

Modeling Stripe Formation on Growing Zebrafish Tailfins

As zebrafish develop, black and gold stripes form across their skin due to the interactions of brightly colored pigment cells. These characteristic patterns emerge on the growing fish body, as well as on the anal and caudal fins. While wild-type stripes form parallel to a horizontal marker on the body, patterns on the tailfin gradually extend distally outward. Interestingly, several mutations lead to altered body patterns without affecting fin stripes. Through an exploratory modeling approach, our goal is to help better understand these differences between body and fin patterns. By adapting a prior agent-based model of cell interactions on the fish body, we present an in silico study of stripe development on tailfins. Our main result is a demonstration that two cell types can produce stripes on the caudal fin. We highlight several ways that bone rays, growth, and the body-fin interface may be involved in patterning, and we raise questions for future work related to pattern robustness.

Characterizing Brain Connectivity From Human Electrocorticography Recordings With Unobserved Inputs During Epileptic Seizures

Epilepsy is a neurological disorder characterized by the sudden occurrence of unprovoked seizures. There is extensive evidence of significantly altered brain connectivity during seizure periods in the human brain. Research on analyzing human brain functional connectivity during epileptic seizures has been limited predominantly to the use of the correlation method. However, spurious connectivity can be measured between two brain regions without having direct connection or interaction between them. Correlations can be due to the apparent interactions of the two brain regions resulting from common input from a third region, which may or may not be observed. Hence, researchers have recently proposed a sparse-plus-latent-regularized precision matrix (SLRPM) when there are unobserved or latent regions interacting with the observed regions. The SLRPM method yields partial correlations of the conditional statistics of the observed regions given the latent regions, thus identifying observed regions that are conditionally independent of both the observed and latent regions. We evaluate the performance of the methods using a spring-mass artificial network and assuming that some nodes cannot be observed, thus constituting the latent variables in the example. Several cases have been considered, including both sparse and dense connections, short-range and long-range connections, and a varying number of latent variables. The SLRPM method is then applied to estimate brain connectivity during epileptic seizures from human ECoG recordings. Seventy-four clinical seizures from five patients, all having complex partial epilepsy, were analyzed using SLRPM, and brain connectivity was quantified using modularity index, clustering coefficient, and eigenvector centrality. Furthermore, using a measure of latent inputs estimated by the SLRPM method, it was possible to automatically detect 72 of the 74 seizures with four false positives and find six seizures that were not marked manually.

Prediction of depression and anxiety via patient-assessed tremor severity, not physician-reported motor symptom severity, in patients with Parkinson’s disease or essential tremor who have undergone deep brain stimulation

OBJECTIVE

Deep brain stimulation (DBS) is an effective therapy for movement disorders such as idiopathic Parkinson’s disease (PD) and essential tremor (ET). However, some patients who demonstrate benefit on objective motor function tests do not experience postoperative improvement in depression or anxiety, 2 important components of quality of life (QOL). Thus, to examine other possible explanations for the lack of a post-DBS correlation between improved objective motor function and decreased depression or anxiety, the authors investigated whether patient perceptions of motor symptom severity might contribute to disease-associated depression and anxiety.

METHODS

The authors performed a retrospective chart review of PD and ET patients who had undergone DBS at the Cleveland Clinic in the period from 2009 to 2013. Patient demographics, diagnosis (PD, ET), motor symptom severity, and QOL measures (Primary Care Evaluation of Mental Disorders 9-item Patient Health Questionnaire [PHQ-9] for depression, Generalized Anxiety Disorder 7-item Scale [GAD-7], and patient-assessed tremor scores) were collected at 4 time points: preoperatively, postoperatively, 1-year follow-up, and 2-year follow-up. Multivariable prediction models with solutions for fixed effects were constructed to assess the correlation of predictor variables with PHQ-9 and GAD-7 scores. Predictor variables included age, sex, visit time, diagnosis (PD vs ET), patient-assessed tremor, physician-reported tremor, Unified Parkinson’s Disease Rating Scale part III (UPDRS-III) score, and patient-assessed tremor over time.

RESULTS

Seventy PD patients and 17 ET patients were included in this analysis. Mean postoperative and 1-year follow-up UPDRS-III and physician-reported tremor scores were significantly decreased compared with preoperative scores (p < 0.0001). Two-year follow-up physician-reported tremor was also significantly decreased from preoperative scores (p < 0.0001). Only a diagnosis of PD (p = 0.0047) and the patient-assessed tremor rating (p < 0.0001) were significantly predictive of depression. A greater time since surgery, in general, significantly decreased anxiety scores (p < 0.0001) except when a worsening of patient-assessed tremor was reported over the same time period (p < 0.0013).

CONCLUSIONS

Patient-assessed tremor severity alone was predictive of depression in PD and ET following DBS. This finding suggests that a patient’s perception of illness plays a greater role in depression than objective physical disability regardless of the time since surgical intervention. In addition, while anxiety may be attenuated by DBS, patient-assessed return of tremor over time can increase anxiety, highlighting the importance of long-term follow-up for behavioral health features in chronic neurological disorders. Together, these data suggest that the patient experience of motor symptoms plays a role in depression and anxiety—a finding that warrants consideration when evaluating, treating, and following movement disorder patients who are candidates for DBS.

855. Impact of FDA Black Box Warning on Fluoroquinolone and Alternative Antibiotic Use in Southeastern US Hospitals

Background

Many antimicrobial stewardship programs have set goals to reduce the use of fluoroquinolones because of risks of causing C. difficile and other adverse safety events. The US Food and Drug Administration issued a black box label warning for fluoroquinolones in June 2016 recommending avoidance of this class for treatment of uncomplicated infections.

Methods

We performed a retrospective cohort study of antimicrobial use (AU) data in 29 southeastern United States hospitals from 2013 to 2017. An interrupted time series approach with segmented negative binomial regression modeling was used to estimate the longitudinal trend and effect of the FDA safety announcement on AU rates. Fluoroquinolone and alternative antibiotic agent use rates were measured as days of therapy (DOT) per 1,000 patient days. Alternative antibiotics were analyzed individually or in groups (e.g., community-onset agent group included ceftriaxone, cefotaxime, and ertapenem).

Results

Hospital AU data for the 60-month period included a total of 6,685,950 patient days; 8 to 29 hospitals contributed AU data to estimates each month. FQ use rates declined at a consistent rate of approximately 1 DOT/1,000 patient days per month resulting in an overall 10% decrease prior to the FDA warning. A significant drop in FQ use rates occurred at the time of the announcement (P = 0.002), but there was no significant change in trend [rate ratio (RR) 0.89, 95% CI 0.79–1.01, P = 0.07, Figure 1]. Alternative antibiotic use significantly increased for the following antibiotic groups after the warning: community-onset agents (RR 1.24, 95% CI 1.11–1.38), atypical agents (RR 1.40, 95% CI 1.19–1.66), and third-generation cephalosporins (RR 1.54, 95% CI 1.19–1.65). Antipseudomonal β-lactam use remained stable (RR 0.96, 95% CI 0.88–1.05, P = 0.3).

Conclusion

Fluoroquinolone use was declining in our network prior to the FDA announcement and continued to decline after 2016. This is likely due to stewardship activities focusing on quinolone-sparing treatment guidelines. AU shifted away from FQ toward third-generation cephalosporins and atypical agents.

Disclosures

All authors: No reported disclosures.

2121. Shifting Surgical Site Infection Denominators and Implication on NHSN Reporting

Background

Per National Healthcare Safety Network (NHSN) rules, when multiple procedures are performed during a single operation, the operation is counted in the surgical site infection (SSI) denominator of each NHSN surgical procedure category. SSIs, however, are counted only in the highest-ranking procedure category. These rules result in procedures that are ineligible to have an associated SSI being counted in SSI denominators.

Methods

We analyzed 3 years (January 1, 2015–December 31, 2017) of laminectomy and rectal surgery SSI data from hospitals in the Duke Infection Control Outreach Network (DICON) that used ICD procedure codes to assign denominators per NHSN definitions. We compared SSI rates using two different denominators: NHSN denominators vs. reduced denominators that counted only primary laminectomy and rectal surgery procedures. We calculated rate ratios (RR) to compare the NHSN and adjusted SSI rates for each procedure for all hospitals that reported at least 1 SSI.

Results

Eleven hospitals reported 87 infections following 17,247 laminectomy procedures. The overall SSI rate increased by 44% when only primary procedures were counted in the denominator (RR 1.44); but individual hospital RR ranged from 1.10 to 2.20 (Table 1). 5 hospitals reported seven SSIs following 740 rectal procedures. The overall SSI rate increased by 143% when only primary procedures were counted in the denominator (RR 2.43), but individual hospital RR ranged from 2.00 to 5.00 (Table 1).

Conclusion

NHSN’s method for calculating SSI denominators underestimates true SSI rate. The current method particularly impacts procedures that are frequently performed in conjunction with higher-ranking NHSN procedures. Counting only primary procedures in procedure category denominators would provide higher, more accurate SSI rates.

Disclosures

All authors: No reported disclosures.

1251. Contaminated Sinks May be an Environmental Source for Serial Transmission of Carbapenem-Resistant Enterobacteriaceae (CRE) to ICU Patients

Background

We performed an investigation after noting an increase in hospital-onset (HO) KPC-producing Enterobacteriaceae (KPC-E) infections in patients admitted to a tertiary referral hospital in North Carolina.

Methods

We defined pre-outbreak (January 1, 2017–June 30, 2017), outbreak (July 1, 2017–October 31, 2017), and post-outbreak (November 1, 2017–March 31, 2018) phases. A clinical case was defined as any positive clinical culture for KPC-E. HO was defined as a positive clinical or surveillance culture collected on hospital day ≥3. Patients were mapped in space and time to inform targeted environmental sampling. Whole-genome sequencing (WGS) was performed on selected KPC K. pneumoniae environmental and patient isolates to determine relatedness.

In October 2017, a CRE prevention bundle was implemented that included daily communication of CRE patient movement, increased audits/feedback of HCW compliance with hand hygiene, enhanced cleaning and disinfection in CRE rooms and high-risk units with bleach and UVC disinfection, and weekly rectal surveillance screens in four adult ICUs.

Results

0.67 clinical cases of KPC-E per month were observed during the pre-outbreak period compared with 3.75 clinical cases of KPC-E per month during the outbreak period. K. pneumoniae was the most common species (Figure 1). Mapping of patients revealed probable direct and indirect transmission between patients in multiple hospital units (Figure 2). three patients who were non-sequentially admitted to the same ICU room over a 12-week span acquired KPC K. pneumoniae (Figure 2). Environmental cultures from the in-room sink drain and P-trap grew KPC K. pneumoniae that was related to the patient isolates by WGS; the sink was removed. Although no additional clinical cases of KPC-E occurred after full implementation of the bundle and sink removal, we continued to observe acquisition of KPC-E rectal colonization in all four ICUs (Figure 3).

Conclusion

We describe a multispecies outbreak of KPC-E that was mitigated through evidence-based CRE control measures and removal of a colonized sink. However, ongoing low-level presumed transmission of KPC points to persistent environmental sources. Additional study is needed to understand the prevalence of CRE in hospital sinks, factors that drive drain colonization, and contribution of CRE in a sink to nosocomial transmission.

Disclosures

All authors: No reported disclosures.

1141. Microbial Assessment of Healthcare-Associated Pathogens on Various Environmental Sites in Patient Rooms After Terminal Room Disinfection

Background

Hospital room environmental surfaces can be contaminated with healthcare-associated pathogens even if terminal room cleaning/disinfection is implemented. We examined the microbiological burden on hospital room environmental sites after standard or enhanced terminal room disinfection.

Methods

Microbial data from the Benefits of Enhanced Terminal Room Disinfection Study were utilized. All patient rooms were randomly assigned to standard disinfection (Quaternary ammonium [Quat]) or an enhanced disinfection (Quat/ultraviolet light [UV-C], Bleach, or Bleach/UV-C). Microbiological samples were obtained using Rodac plates (25 cm²/plate) from 8 of 10 hospital room sites, including bed rail, over-bed table, supply/medicine cart, chair, side counter, linen hamper lid, sink, toilet seat, shower floor, and bathroom floor. The number of colony forming units (CFU) of four target epidemiologically important pathogens (EIP), including multidrug-resistant Acinetobacter, Clostridium difficile, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci, was counted. A total of 3,680 samples from 736 environmental sites in all 92 patient rooms (21 standard rooms and 71 enhanced rooms) were analyzed.

Results

Overall, the frequency of all environmental sites positive for EIP was 11% (84/736) in all rooms, 21% (36/168) in standard rooms, and 8% (48/568) in enhanced rooms (P < 0.001) (Figure 1). Environmental sites, other than the toilet seat, in standard rooms were likely to be more frequently contaminated with EIP than in enhanced rooms (P = 0.013 for overbed table, P = 0.010 for bed rail, and P > 0.05 for other sites each). Mean CFU of EIP per room was 19.2 in all rooms, 60.8 in standard rooms, and 6.9 in enhanced rooms (P = 0.006) (Figure 2). All sites in standard rooms tended to have higher mean counts than in enhanced rooms (P = 0.001 for overbed table, P = 0.001 for bed rail, P = 0.012 for side counter, and P > 0.05 for other sites each).

Conclusion

Our results demonstrate that an enhanced terminal room disinfection reduced microbial burden of healthcare-associated pathogens on environmental sites better than standard room disinfection. Environmental hygiene of touchable surfaces after terminal room cleaning using Quat needs to be improved.

Disclosures

W. Rutala, PDI: Consultant and Speaker’s Bureau, Consulting fee and Speaker honorarium. D. Weber, PDI: Consultant, Consulting fee.

Barrow Innovation Center Case Series: Early Clinical Experience with Novel Surgical Instrument Used To Prevent Intraoperative Spinal Cord Injuries

OBJECTIVE

The Barrow Innovation Center comprises an educational program in medical innovation that enables residents to identify problems in patient care and rapidly develop and implement solutions to these problems. Residents involved in this program noted an elevated risk of iatrogenic spinal cord injury during posterior cervical and thoracic procedures. The objective of this study was to describe this complication, and a novel solution was developed through a new innovation training program.

METHODS

A case report demonstrates the risk of iatrogenic spinal cord injury during posterior cervical decompression and fusion. Solutions to this problem were developed at the innovation center via an iterative process of prototype creation, cadaveric testing, and redesign. Patent law students who partnered with the center wrote and filed a provisional patent protecting the novel prototype designs.

RESULTS

The concept of a protective shield for the spinal cord was developed, and within only 6 weeks the devices were provisionally patented and used in the operating room. This device was named the Myeloshield. Initial clinical experience indicates that the Myeloshield can be used without impeding the flow of surgery and has the potential to prevent iatrogenic spinal cord injury; this experience is presented through 2 case reports demonstrating the use of Myeloshields in the operating room.

CONCLUSIONS

This report demonstrates how programs like the Barrow Innovation Center can provide neurosurgery residents with a unique educational experience in medical device innovation and intellectual property development and can serve as an avenue of surgical quality improvement and problem solving.

The Effect of National Healthcare Safety Network (NHSN) Rebaselining on Community Hospital SIRs

Background

The NHSN recently updated risk adjustment models and “rebaselined” Standardized Infection Ratios (SIRs) for healthcare-associated infections. The CDC expected that hospital SIRs would generally increase. However, the impact of rebaselining on individual hospitals’ SIRs was unknown. Accordingly, we assessed the impact of rebaselining on SIRs in a network of community hospitals.

Methods

We analyzed 2016 SIR data for CAUTI, MRSA LabID events, CDI LabID events, colon SSIs (COLO), and abdominal hysterectomy SSIs (HYST) from 38 hospitals in the Duke Infection Control Outreach Network (DICON). SIRs calculated using the old and new baselines were compared. Wilcoxon signed rank test was performed to determine whether hospitals’ SIRs changed significantly following rebaselining. Hospitals were ranked by SIR for each metric, and change in rank following rebaselining was determined. Meaningful change in rank was defined as increase or decrease by ≥4 places (greater than a decile). Hospitals that did not have an SIR calculated for a given metric were excluded from that metric’s analysis.

Results

Median hospital SIRs for CAUTI and CDI increased significantly after rebaselining (0.587 vs 0.307, P &lt; 0.001; and 0.825 vs 0.783, p = 0.04, respectively). Median MRSA SIRs increased (0.903 vs 0.797, P = 0.5), and COLO and HYST SIRs decreased (0.457 vs 0.586, P = 0.1; and 0 vs 0.489, P = 0.4); however, these changes were not statistically significant (Figure 1). For all metrics, a minority of hospitals had meaningful change in SIR rank following rebaselining (Figure 2).

Conclusion

SIRs increased following rebaselining for CAUTI and CDI but did not change significantly for MRSA, COLO, or HYST. The majority of hospitals’ SIR rank did not change meaningfully following rebaselining.

Disclosures

D. Sexton, Centers for Disease Control and Prevention: Grant Investigator, Grant recipient; Centers for Disease Control and Prevention Foundation: Grant Investigator, Grant recipient; UpToDate: Collaborator, Royalty Recipient

Outcomes of Subdural Grid Electrode Monitoring in the Stereoelectroencephalography Era

BACKGROUND

Subdural grid (SDG) electrodes have been the gold standard of invasive monitoring in medically refractory epilepsy; however, in some centers, application of SDGs has been reduced by the progressive application of stereoelectroencephalography (SEEG). This study reviews the efficacy of SDG electrode monitoring after the incorporation of the SEEG methodology at our institution.

METHODS

We retrospectively reviewed 102 patients undergoing intracranial monitoring via SDG electrodes during the years 2010-2013 at our institution. The series includes all patients who underwent SDG placement after the incorporation of SEEG in our extraoperative invasive monitoring armamentarium.

RESULTS

Average patient age was 29.9 years old; the series included 31 pediatric patients. There were 49 male patients and 53 female patients. The mean length of follow-up was 21.5 months. The epileptogenic zone was localized in 99 (97%) patients. Surgical resection was performed in 84 patients, and 70% experienced Engel class I freedom from seizures.

CONCLUSIONS

Invasive monitoring via SDG electrodes continues to be an efficacious option for select patients with medically refractory epilepsy, mainly when the hypothetical epileptogenic zone is anatomically restricted to superficial cortical areas and in close relation with eloquent cortex. This is the first report of epilepsy outcomes after SDG monitoring at a center that also performs SEEG monitoring. Our results suggest a complementary benefit of performing both techniques at 1 institution.

The preventability of ventilator-associated events. The CDC Prevention Epicenters Wake Up and Breathe Collaborative

RATIONALE

The CDC introduced ventilator-associated event (VAE) definitions in January 2013. Little is known about VAE prevention. We hypothesized that daily, coordinated spontaneous awakening trials (SATs) and spontaneous breathing trials (SBTs) might prevent VAEs.

OBJECTIVES

To assess the preventability of VAEs.

METHODS

We nested a multicenter quality improvement collaborative within a prospective study of VAE surveillance among 20 intensive care units between November 2011 and May 2013. Twelve units joined the collaborative and implemented an opt-out protocol for nurses and respiratory therapists to perform paired daily SATs and SBTs. The remaining eight units conducted surveillance alone. We measured temporal trends in VAEs using generalized mixed effects regression models adjusted for patient-level unit, age, sex, reason for intubation, Sequential Organ Failure Assessment score, and comorbidity index.

MEASUREMENTS AND MAIN RESULTS

We tracked 5,164 consecutive episodes of mechanical ventilation: 3,425 in collaborative units and 1,739 in surveillance-only units. Within collaborative units, significant increases in SATs, SBTs, and percentage of SBTs performed without sedation were mirrored by significant decreases in duration of mechanical ventilation and hospital length-of-stay. There was no change in VAE risk per ventilator day but significant decreases in VAE risk per episode of mechanical ventilation (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.42-0.97) and infection-related ventilator-associated complications (OR, 0.35; 95% CI, 0.17-0.71) but not pneumonias (OR, 0.51; 95% CI, 0.19-1.3). Within surveillance-only units, there were no significant changes in SAT, SBT, or VAE rates.

CONCLUSIONS

Enhanced performance of paired, daily SATs and SBTs is associated with lower VAE rates. Clinical trial registered with www.clinicaltrials.gov (NCT 01583413).

Lithium in patients with amyotrophic lateral sclerosis (LiCALS): a phase 3 multicentre, randomised, double-blind, placebo-controlled trial

Background

Lithium has neuroprotective effects in cell and animal models of amyotrophic lateral sclerosis (ALS), and a small pilot study in patients with ALS showed a significant effect of lithium on survival. We aimed to assess whether lithium improves survival in patients with ALS.

Methods

The lithium carbonate in amyotrophic lateral sclerosis (LiCALS) trial is a randomised, double-blind, placebo-controlled trial of oral lithium taken daily for 18 months in patients with ALS. Patients aged at least 18 years who had ALS according to the revised El Escorial criteria, had disease duration between 6 and 36 months, and were taking riluzole were recruited from ten centres in the UK. Patients were randomly assigned (1:1) to receive either lithium or matched placebo tablets. Randomisation was via an online system done at the level of the individual by block randomisation with randomly varying block sizes, stratified by study centre and site of disease onset (limb or bulbar). All patients and assessing study personnel were masked to treatment assignment. The primary endpoint was the rate of survival at 18 months and was analysed by intention to treat. This study is registered with Eudract, number 2008-006891-31.

Findings

Between May 26, 2009, and Nov 10, 2011, 243 patients were screened, 214 of whom were randomly assigned to receive lithium (107 patients) or placebo (107 patients). Two patients discontinued treatment and one died before the target therapeutic lithium concentration could be achieved. 63 (59%) of 107 patients in the placebo group and 54 (50%) of 107 patients in the lithium group were alive at 18 months. The survival functions did not differ significantly between groups (Mantel-Cox log-rank χ² on 1 df=1·64; p=0·20). After adjusting for study centre and site of onset using logistic regression, the relative odds of survival at 18 months (lithium vs placebo) was 0·71 (95% CI 0·40–1·24). 56 patients in the placebo group and 61 in the lithium group had at least one serious adverse event.

Interpretation

We found no evidence of benefit of lithium on survival in patients with ALS, but nor were there safety concerns, which had been identified in previous studies with less conventional designs. This finding emphasises the importance of pursuing adequately powered trials with clear endpoints when testing new treatments.

Funding

The Motor Neurone Disease Association of Great Britain and Northern Ireland.

Role of plasma kallikrein-kinin system activation in synovial recruitment of endothelial progenitor cells in experimental arthritis

OBJECTIVE

To examine whether activation of the plasma kallikrein-kinin system (KKS) mediates synovial recruitment of endothelial progenitor cells (EPCs) in arthritis.

METHODS

EPCs were isolated from Lewis rat bone marrow, and expression of progenitor cell-lineage markers and functional properties were characterized. EPCs were injected intravenously into Lewis rats with arthritis, and their recruitment and formation of de novo blood vessels in inflamed synovium were evaluated. The role of plasma KKS was examined using a plasma kallikrein inhibitor (EPI-KAL2) and an antikallikrein antibody (13G11). A transendothelial migration assay was used to determine the role of bradykinin and its receptor in EPC mobilization.

RESULTS

EPCs from Lewis rats exhibited a strong capacity to form tubes and vacuoles and expressed increased levels of bradykinin type 2 receptor (B2R) and progenitor cell markers CD34 and Sca-1. In Lewis rats with arthritis, EPCs were recruited into inflamed synovium at the acute phase of disease and formed de novo blood vessels. Inhibition of plasma kallikrein by EPI-KAL2 and 13G11 significantly suppressed synovial recruitment of EPCs and hyperproliferation of synovial cells. Bradykinin stimulated transendothelial migration of EPCs in a concentration-dependent manner. This was mediated by B2R, as demonstrated by the finding that knockdown of B2R with silencing RNA completely blocked bradykinin-stimulated transendothelial migration. Moreover, bradykinin selectively up-regulated expression of the homing receptor CXCR4 in EPCs.

CONCLUSION

These observations demonstrate a novel role of plasma KKS activation in the synovial recruitment of EPCs in arthritis, acting via kallikrein activation and B2R-dependent mechanisms. B2R might be involved in the mobilization of EPCs via up-regulation of CXCR4.

Opening- or closing-wedged high tibial osteotomy: a meta-analysis of clinical and radiological outcomes

High tibial osteotomy (HTO) has been advocated for the treatment of isolated medial compartment osteoarthritis of the knee. Debate remains over the superiority of performing a medial opening-wedge or lateral closing-wedge HTO. The purpose of this study was to compare the clinical and radiological outcomes, and complications of patients following opening-wedge compared to closing-wedge HTO. A systematic review was undertaken of published and unpublished literature databases from their inception to May 2010. Twelve papers reporting nine clinical trials were found to be suitable for meta-analysis comparing 324 opening-wedge HTOs to 318 closing-wedge HTOs. There was no difference in the incidence of infection, deep vein thrombosis, peroneal nerve palsy, non-union or revision to knee arthroplasty (p>0.05). There was however a significantly greater posterior tibial slope and mean angle of correction, reduced patellar height and hip-knee-ankle angle following opening-wedge HTO (p<0.05). No significant difference was found for any clinical outcome including pain, functional score or complications (p>0.05).

Molecular characterization of Rickettsia rickettsii infecting dogs and people in North Carolina

Rocky Mountain spotted fever (RMST) is an important cause of morbidity and mortality in people and dogs in the United States. Disease manifestations are strikingly similar in both species, and illness in dogs can precede illness in people. R. rickettsii has been identified as a Select Agent by the CDC as a Category C priority pathogen by the National Institute of Allergic and Infectious Diseases because it is amenable to use as a bioterror agent. The clinical and temporal relationship of naturally occurring diseases in dogs and people suggests that dogs could serve as sentinels for natural infection and bioterrorist attacks using this organism. Recognizing genetic modifications in naturally occurring disease agents in order to distinguish them from intentionally released agents are priorities put forth by the NIAID. To determine whether the rickettsiae naturally infecting dogs is the same as those that infect persons in a given geographical region, we characterized rickettsial isolates obtained from three dogs and two persons diagnosed with RMSF in North Carolina. Portions of three genes (ompA, rrs, and gltA) amplified by PCR were cloned and sequenced or directly sequenced. Reactions were run in duplicate in forward and reverse directions. Gene sequences were aligned with known sequences deposited in GenBank and with each other. Sequences of the 5' region of the ompA gene were 100% homologous with a tick strain (Bitterroot) of R. rickettsii for all five isolates. Sequences of the rrs gene were 99.8 99.9% homologous with a tick strain (Sawtooth) of R. rickettsii. rrs gene sequences from one dog and the two persons was identical. Sequences of one dog isolate differed from these by one base pair. Sequences from another dog isolate differed by two base pairs. Sequences of the gltA gene are pending. This confirms on a molecular level that R. rickettsii causing naturally occurring RMSF in dogs in North Carolina is highly homologous to R. rickettsii that causes the disease in people in the same region. Sequence data will be deposited in GenBank, thereby providing genetic information regarding naturally occurring R. rickettsii.

A distinct strategy to generate high-affinity peptide binders to receptor tyrosine kinases

We describe a novel and general way of generating high affinity peptide (HAP) binders to receptor tyrosine kinases (RTKs), using a multi-step process comprising phage-display selection, identification of peptide pairs suitable for hetero-dimerization (non-competitive and synergistic) and chemical synthesis of heterodimers. Using this strategy, we generated HAPs with K(D)s below 1 nM for VEGF receptor-2 (VEGFR-2) and c-Met. VEGFR-2 HAPs bound significantly better (6- to 500-fold) than either of the individual peptides that were used for heterodimer synthesis. Most significantly, HAPs were much better (150- to 800-fold) competitors than monomers of the natural ligand (VEGF) in various competitive binding and functional assays. In addition, we also found the binding of HAPs to be less sensitive to serum than their component peptides. We believe that this method may be applied to any protein for generating high affinity peptide (HAP) binders.

Uncertainty in predictions of the climate response to rising levels of greenhouse gases

The range of possibilities for future climate evolution needs to be taken into account when planning climate change mitigation and adaptation strategies. This requires ensembles of multi-decadal simulations to assess both chaotic climate variability and model response uncertainty. Statistical estimates of model response uncertainty, based on observations of recent climate change, admit climate sensitivities--defined as the equilibrium response of global mean temperature to doubling levels of atmospheric carbon dioxide--substantially greater than 5 K. But such strong responses are not used in ranges for future climate change because they have not been seen in general circulation models. Here we present results from the 'climateprediction.net' experiment, the first multi-thousand-member grand ensemble of simulations using a general circulation model and thereby explicitly resolving regional details. We find model versions as realistic as other state-of-the-art climate models but with climate sensitivities ranging from less than 2 K to more than 11 K. Models with such extreme sensitivities are critical for the study of the full range of possible responses of the climate system to rising greenhouse gas levels, and for assessing the risks associated with specific targets for stabilizing these levels.

Staphylococcus aureus pericardial abscess in a patient with liver cirrhosis: case report

Pericardial abscess is a rare complication of Staphylococcus aureus bacteremia. We report the case of a 40-year-old man with hepatitis C and liver cirrhosis who presented with high-grade fever and chest pain. Transthoracic echocardiography showed a pericardial mass and computed tomographic scanning and transesophageal echocardiography confirmed the presence of a loculated fluid collection. His illness persisted despite i.v. antibiotics and video-assisted thoracoscopic drainage. The patient was cured after surgical drainage and pericardiectomy.

Proteomic analysis of a developmentally regulated secretory vesicle

Secretion of spore coat proteins from the prespore secretory vesicles (PSVs) in Dictyostelium discoideum is a signal mediated event that underlies terminal cell differentiation, and represents an important case of developmentally regulated secretion. In order to study the biochemical mechanisms that govern the regulated fusion of the PSVs with the plasma membrane and the subsequent secretion of their cargo, we purified this organelle from prespore cells. Analysis of protein extracts of highly purified PSVs indicated that, in addition to the cargo of structural spore coat proteins, many more proteins are associated with the PSVs. Their identification is paramount to the understanding of the mechanism of regulated secretion in this system. In this study we have taken the first comprehensive proteomic approach to the analysis of an entire, previously uncharacterized, organelle, with the goal of identifying the major proteins associated with the PSVs. We show that in addition to the structural spore coat proteins, the PSVs contain the enzymes needed for proper spore coat assembly (thioredoxin 2 and 3), regulatory proteins which we predict receive and transduce the developmental signal for secretion (rab7 GTPase, PI-3 kinase, NDP kinase and the calcium binding proteins calfumirin-1 and calreticulin) as well as proteins that interact with the cytoskeleton to mediate movement of the PSVs to the plasma membrane (actin binding proteins coactosin and profilin 1). In addition, the results suggest that proteins can play multiple roles in the cell, and that protein function can be dictated in part by subcellular localization. The identification of the PSV proteins is allowing us to develop testable hypotheses about the roles of these proteins within the functional context of developmentally regulated secretion.

Strategy for protein isoform identification from expressed sequence tags and its application to peptide mass fingerprinting

Expressed Sequence Tags (ESTs) are an invaluable resource for protein identification and characterisation in proteomics. They allow proteins to be identified in the absence of genome sequence data. When EST sequences are used for protein identification, they are usually first processed into contigs to reduce redundancy and generate longer sequences from the overlapping ESTs. However, the process of generating contigs may accidentally group biologically meaningful isoforms together. Here we report means of discovering isoforms in EST sequences and how to use this information in the framework of protein identification and characterisation with peptide mass fingerprinting. We illustrate our strategies with examples from the dbEST database as well as protein isoforms from two-dimensional polyacrylamide gels.

Human mitogen-activated protein kinase kinase 4 as a candidate tumor suppressor

Mitogen-activated protein kinases function in signal transduction pathways that are involved in controlling key cellular processes in many organisms. A mammalian member of this kinase family, MKK4/JNKK1/SEK1, has been reported to link upstream MEKK1 to downstream stress-activated protein kinase/JNK1 and p38 mitogen-activated protein kinase. This mitogen-activated protein kinase pathway has been implicated in the signal transduction of cytokine- and stress-induced apoptosis in a variety of cell types. Here, we report that two human tumor cell lines, derived from pancreatic carcinoma and lung carcinoma, harbor homozygous deletions that eliminate coding portions of the MKK4 locus at 17p, located approximately 10 cM centromeric of p53. In addition, in a set of 88 human cancer cell lines prescreened for loss of heterozygosity, we detected two nonsense and three missense sequence variants of MKK4 in cancer cell lines derived from human pancreatic, breast, colon, and testis cells. In vitro biochemical assays revealed that, when stimulated by MEKK1, four of the five altered MKK4 proteins lacked the ability to phosphorylate stress-activated protein kinase. Thus, the incidence of coding mutations of MKK4 in the set of cell lines is 6 of 213 (approximately 3%). These findings suggest that MKK4 may function as a suppressor of tumorigenesis or metastasis in certain types of cells.

Correlates of the quality of life of adults with severe or profound mental retardation

To ensure quality of services for individuals with mental retardation/developmental disability, professionals must measure consumer outcomes related to lifestyle. In this study variables contributing to quality of life for 60 adults with severe or profound disabilities who resided in ICF/MR community-based homes for 4 to 5 persons were examined. Using the Quality of Life Index, we studied interrelations among personal lifestyle characteristics of adults and community-home program characteristics with quality of life factors. The R2 effect size (.571) involving total scores on the Quality of Life Index as the criterion variable was large and statistically significant.

Localization of SMAD5 and its evaluation as a candidate myeloid tumor suppressor

Acquired interstitial or complete losses of chromosome 5 are recurring anomalies associated with preleukemic myelodysplasia and acute myelogenous leukemia with a poor prognosis. Previous studies have delineated a potential myeloid tumor suppressor locus to a <2.4-Mb interval between the genes for IL9 and EGR1 on 5q31. In this report, we have localized the SMAD5 gene, a homologue of the tumor suppressor genes SMAD4/DPC-4 and SMAD2/JV18.1, to the minimal myeloid tumor suppressor locus and characterized its open reading frame and genomic organization. SMAD5 transcripts are readily detectable in hematolymphoid tissues and leukemic blasts. Absence of intragenic mutations in the remaining SMAD5 allele of leukemic patients and multiple solid tumor cell lines prescreened for loss of heterozygosity suggests that SMAD5 may not be a common target of somatic inactivation in malignancy.