MAP9/MAPH-9 supports axonemal microtubule doublets and modulates motor movement

Microtubule doublets (MTDs) comprise an incomplete microtubule (B-tubule) attached to the side of a complete cylindrical microtubule. These compound microtubules are conserved in cilia across the tree of life; however, the mechanisms by which MTDs form and are maintained in vivo remain poorly understood. Here, we identify microtubule-associated protein 9 (MAP9) as an MTD-associated protein. We demonstrate that C. elegans MAPH-9, a MAP9 homolog, is present during MTD assembly and localizes exclusively to MTDs, a preference that is in part mediated by tubulin polyglutamylation. We find that loss of MAPH-9 causes ultrastructural MTD defects, including shortened and/or squashed B-tubules with reduced numbers of protofilaments, dysregulated axonemal motor velocity, and perturbed cilia function. Because we find that the mammalian ortholog MAP9 localizes to axonemes in cultured mammalian cells and mouse tissues, we propose that MAP9/MAPH-9 plays a conserved role in regulating ciliary motors and supporting the structure of axonemal MTDs.

Translating Animal Models of Ischemic Stroke to the Human Condition

Ischemic stroke is a leading cause of death and disability. However, very few neuroprotective agents have shown promise for treatment of ischemic stroke in clinical trials, despite showing efficacy in many successful preclinical studies. This may be attributed, at least in part, to the incongruency between experimental animal stroke models used in preclinical studies and the manifestation of ischemic stroke in humans. Most often the human population selected for clinical trials are more diverse than the experimental model used in a preclinical study. For successful translation, it is critical to develop clinical trial designs that match the experimental animal model used in the preclinical study. This review aims to provide a comprehensive summary of commonly used animal models with clear correlates between rodent models used to study ischemic stroke and the clinical stroke pathologies with which they most closely align. By improving the correlation between preclinical studies and clinical trials, new neuroprotective agents and stroke therapies may be more accurately and efficiently identified.

Assisted Reproductive Technology Treatment Outcomes in Women With Liver Disease

INTRODUCTION

There is a need for evidence-based counseling for women with chronic liver disease (LD) who may experience impaired fertility. Currently, the literature on assisted reproductive technology (ART) treatment in women with LD has been limited to a single European case series. We evaluated ART treatment outcomes in patients with LD and compared with controls.

METHODS

The retrospective study evaluated women with and without LD who had normal ovarian reserve and underwent ART treatment in a high-volume fertility practice from 2002 to 2021.

RESULTS

We identified 295 women with LD (mean age 37.8 ± 5.2 years) who underwent 1,033 ART treatment cycles; of these women, 115 underwent 186 in vitro fertilization (IVF) cycles. Six women (2.0%) had cirrhosis, 8 (2.7%) were postliver transplantation, and 281 (95.3%) had chronic LD, with viral hepatitis (B and C) being the most prevalent. In the subgroup who underwent IVF and embryo biopsy, the median fibrosis-4 score was 0.81 (0.58-1.03), and there were no statistically significant differences in response to controlled ovarian stimulation, embryo fertilization rate, or ploidy outcome in patients with LD compared with controls. In those who subsequently underwent a single thawed euploid embryo transfer to achieve pregnancy, there were no statistically significant differences in rates of clinical pregnancy, clinical pregnancy loss, or live birth in patients with LD compared with controls.

DISCUSSION

To the best of our knowledge, this study is the largest to date to evaluate IVF efficacy in women with LD. Our study demonstrates that patients with LD have similar ART treatment outcomes compared with those without LD.

Strain-induced dark exciton generation in rippled monolayer MoS2

Recently, it has been revealed that dark excitons play a significant role in optically controlled information processing due to their much longer radiative lifetimes than those of bright ones. For the realizable implementation of the features, it is important to understand and manipulate conditions in which dark excitons could exist. We adopt strain-engineered rippling as a new parameter for the modification of the electronic structure of monolayer MoS₂ and demonstrate the efficient conversion of bright to dark excitons via a first-principles study. For rippled monolayer MoS₂ above a strain of ∼6.8%, we show that the spin order of the conduction band is reversed and the spin forbidden dark exciton then goes below the bright one.

Abstract WMP19: When Minutes Count: Addition Of Stroke Transfer Coordinator

The treatment of hyper acute ischemic stroke is time critical, requiring a coordinated team response. It is common among primary and comprehensive stroke centers to have a “stroke alert” process, activating physicians, laboratory, radiology, and nursing support. In our center, the stroke alert included activation of a stroke program coordinator during day hours to assist with data gathering and time tracking. A clinical nurse expert would attend stroke alerts as able to on nightshift. At times, there were gaps when no personnel were available, and data was backtracked. In 2021, the use of Viz.AI was implemented. The Viz app allows streamlined communication amongst the treatment team (MD, ED Charge, Bed Capacity, etc.). Information including COVID status, time of Contrast given, imaging studies, and family contact information are exchanged prior to the patient’s arrival. Six Stroke Transfer Coordinators (STC) were hired, whose primary focus was attending stroke alerts, monitoring CT scans through the Viz app, and facilitating the transfer of patients with Large Vessel Occlusion (LVO) for thrombectomy treatment.

Methods: This is a single center retrospective cohort study. Basic demographic data, presence of LVO, time of last known well, time of imaging, time of transfer acceptance, NIHSS, and thrombolysis prior to transfer were recorded. Door-in-door out, door-to-angiogram, and door-to-groin puncture times were also collected. We compared and analyzed data from 12 months prior to implementation of the STC (August 2020-July 2021) to the 12 months post-implementation (August 2021 to July 2022).

Results: Total number of Stroke Alerts (SA) in the pre-STC time period was 1479, with 136 thrombectomy alert. Post-TSC the total number of SA was 1306, with 179 thrombectomy alerts. The mean door-to-intervention time pre-STC was 24 minutes (median=25 minutes). Post implementation of the STC, the mean door-to-intervention time was 17 minutes (median= 12 minutes).

Conclusions: STC’s improved the door-to-intervention time by mean of 7 minutes (median= 13 minutes). When every minute counts in re-establishing brain perfusion, this improvement may lead to better patient outcomes. Further study is necessary.

Paradoxical Cerebral Air Embolism after Cardiac Ablation in Williams-Beuren Syndrome: A Clinico-Pathological Correlation

Non-traumatic neurological deterioration is a medical emergency that may arise from diverse causes, to include cerebral infarction or intracranial hemorrhage, meningoencephalitis, seizure, hypoxic-ischemic or toxic/metabolic encephalopathy, poisoning, or drug intoxication. We describe the abrupt onset of neurological deterioration in a 53-year-old man with Williams-Beuren syndrome, a sporadically occurring genetic disorder caused by chromosomal microdeletion at 7q11.23. The clinical phenotype of Williams-Beuren syndrome is suggested by distinctive elfin facies, limited intellect, unique personality features, growth abnormalities, and endocrinopathies. The causative microdeletion of chromosomal material will frequently involve loss of the elastin gene, ELN, with resulting arteriopathy, supravalvular aortic stenosis, non-ischemic cardiopathy, and atrial fibrillation. Our patient sustained acute neurological decline within one month after undergoing a cardiac ablative procedure to convert atrial fibrillation to sinus rhythm. We present our findings in the setting of a clinico-pathological correlation, in which we reveal the cause of the abrupt neurological deterioration and discuss how our patient was affected by an uncommon stroke disorder.

Abstract P692: This is Your Brain on Drugs: The Burden and Severity of Stroke Related to Substance Use and Infective Endocarditis

Background: Substance abuse is a major health crisis in the US, with approximately 20 million people suffering from substance use disorders (SUD). The rate of opioid-related overdose deaths in Kentucky has climbrf from 1.3 per 100,000 persons in 1999 to a staggering 23.6 in 2016. SUD is a risk factor for infectious endocarditis (IE), an important cause of stroke in young patients. We previously reported that SUD in stroke is associated with poorer admission NIH stroke scales and longer lengths of stay (LOS) compared to patients without SUD.

Objective: To describe the burden of stroke due to endocarditis in a regional population within Kentucky, and to compare outcomes of stroke in patients with SUD with or without evidence of IE.

Methods: This is a single center, retrospective chart review of patients with SUD and stroke. Subjects included adults age > 18 years, who received the diagnosis of acute stroke, and were identified as an illicit drug user based on either urine drug testing or provided history in the medical record, admitted between October 2015 and May 2019. Data elements collected included length of stay (LOS), admission/discharge NIH stroke scale scores, drug use history, laboratory data, discharge modified Rankin Scores, intracerebral hemorrhage (ICH) scores, and discharge status.

Results: We identified 197 (M=157, 74.6%) SUD/IE-, and 116 (M=81, 69.8%) SUD/IE+ stroke cases. SUD+/IE+ cases were younger with a mean age of 36.53 +/- 8.94, as compared to SUD+/IE-, mean age of 54.94 +/-12.01 (p<0.0001). Ischemic stroke was more common than ICH in both groups. While admission NIHSS scores were similar in the two groups, SUD+/IE+ patients had longer lengths of stay (29.60 +/-25.73 days vs. 11.65 +/-16.95, p<0.0001), and experienced greater mortality, with 38 deaths (32.8% SUD+/IE+) as compared to 20 (10.2%) in the SUD+/IE- group, p<0.0001. An additional 16 (13.8%) patients IE+ were discharged to hospice, compared to 8 (4.1%) in the IE- group, p=0.003.

Conclusion: Within our regional population, there is a high burden of SUD-related infective endocarditis and stroke, which is associated with poorer outcomes and increased mortality. Further study is warranted to examine the socioeconomic factors influencing SUD in our population to reduce overall disease burden.

Abstract P583: Comparison of FAST-S to BEFAST-S for Pediatric Stroke: A Comprehensive Stroke Center Retrospective Analysis

Objective: To assess the demographic characteristics and presenting symptoms in a cohort of pediatric patients with ischemic stroke and develop a tool to improve recognition of ischemic stroke at the institution and in the community.

Methods: We conducted a retrospective review of children aged 1 month to 18 years with radiologically confirmed ischemic stroke admitted to the University of Kentucky between January 2013 and June 2020. Characteristics such as age, sex, and diagnosis were recorded. The FAST (Face, Arms, Speech) and BEFAST (Balance, Eyes, Face, Arms, Speech) mnemonics were applied to all patients. We then applied the FAST-S tool and used the novel BEFAST-S. FAST-S adds new onset seizure to the previously validated tool.

Results: For the study period, we identified 158 cases. Most patients were ≥ 3 years of age (n=113) and most were male (n=96). About one third (31%, n=50) of presentations concerning for stroke had diagnosed ischemic stroke at time of discharge; the majority were ≥ 3 years of age (n=31). Strokes were commonly associated with trauma (24%, n=12) and infection (22%, n=11). Common mimics for stroke included seizure in the absence of stroke (30%, n=33), migraine (18%, n=20), and conversion disorder (13%, n=14). FAST and BEFAST each identified the same 30 patients as having ischemic stroke (60%), with 26 patients being ≥ 3 years of age. Inclusion of new onset seizures (FAST-S/BEFAST-S) correctly identified one additional patient ≥ 3 years of age (87%, n=27) and nine additional patients under 3 (n=19, 78% versus n=4, 21%). New onset seizure reduced the number of missed strokes regardless of age from 40% (n=20) to 16% (n=8).

Conclusions: Although BEFAST improves the sensitivity of identification of ischemic strokes in adults, it did not identify additional strokes beyond FAST in our pediatric population. Inclusion of new onset seizure in addition to either FAST or BEFAST, however, reduced the number of missed strokes by at least half, particularly in children < 3 years of age. Thus, education of FAST-S or BEFAST-S may be useful for providers and emergency services.

Dual Resonant Sum Frequency Generations from Two-Dimensional Materials

We propose dual resonant optical sum frequency generation (SFG), where the two most singular resonances could be selected, and report for the monolayer (1L-) WSe₂ when one (ω₁) of two excitation pulses is resonant to A exciton and their sum frequency (ω₁ + ω₂) to D exciton. The dual resonant SFG confirms that, under an irradiation of ω₁ and ω₂ pulses with the same fluence of ∼1.4 × 10¹⁰ W/m², its signal intensity could be enhanced about 20 times higher than the resonant SHG (i.e., 2ω₁ to the D excitonic absorption). Further, the dual resonant SFG intensity of 1L-WSe₂ is found to be 1 order of magnitude higher than the single resonant SFG intensity of 1L-WS₂ under the same condition of two-pulse irradiation. Finally, observations of the dual resonant SFG are thoroughly examined using real-time time-dependent density functional theory (rt-TDDFT), and the relevant nonlinear optical characteristics are scrutinized using the Greenwood-Kubo formalism.

Abstract TP136: A Retrospective Study of Moyamoya in a Unique, Primarily Caucasian Southern US Population

Background: Moyamoya (MM) is an uncommon cerebrovascular disease characterized by bilateral, progressive stenosis and occlusion at the terminal portion of the internal carotid arteries around the circle of Willis. MM has a higher prevalence in East Asian population; however, an increasing number of cases of MM are being reported in the US and may reflect a different entity often termed moyamoya syndrome (MMS). A study from 2005 to 2008, reported a 4-fold increase in the prevalence of MM in the US. In this study, we sought to describe the clinical features of patients diagnosed with MMS in a unique, primarily Caucasian Southern US population.

Materials and Methods: We performed a retrospective chart review of patients evaluated at our institution from August 2012 to December 2018. Data collected included age, sex, ethnicity, comorbid medical conditions, and laboratory values.

Results: Seventy-seven patients with MM were included (52 female and 25 male), average age at time of diagnosis was 42 for females and 48 for males. 81% were Caucasian while 17% were African American, and 3% were Asian. Hypertension was the most common comorbidity affecting these individuals (60%), with hyperlipidemia being the second most common (36%). Autoimmune disorders affected about 22% of this population. The average BMI of females and males was 35 and 29, respectively. Lipid analysis showed similarity in profiles between males and females, and no significant trends were appreciated respective to BMI and age. Interestingly, 85% of individuals had an elevation of sedimentation rate (ESR), Factor VIII, or C - reactive protein (CRP) at the time of diagnosis.

Conclusions: Women are affected in a 2:1 ratio as compared to men; which is a consistent trend reported in other studies. Hypertension remains the most common comorbidity affecting these individuals. Though the etiology of MMS remains unclear, various autoimmune disorders have been reported in small case series. While ESR, factor VIII activity, and CRP are non-specific markers of inflammation, the high prevalence of these markers in this population further support an autoimmune or immunological component in MM. Additional prospective studies are needed to further elucidate this relationship.

Abstract TP151: Box Checking for Comprehensive Stroke Care Metrics of Depression Screening: Does It Actually Equate to Better Treatment

Objective: One in three stroke patients develop depression following the event. The exact cause of post stroke depression has been debated but may be due to brain injury resulting from stroke and psychological factors. We aimed to 1) Discover frequency of patients suffering from depressive symptoms post-stroke 2) Ascertain whether occurrence of post-stroke depression plays a role in adherence to follow up appointment 3) Determine the frequency of antidepressant treatment post-stroke and 4) Identify location of stroke most commonly associated with depression.

Methods: We conducted a single institution, retrospective chart review of patients ≥18 years, discharged with ischemic stroke from October2017 - March2018. Variables such as age, sex, location of stroke, discharge PHQ9 score, depression treatment and follow up appointment adherence were determined.

Results: In our cohort of 200 patients (48.5% M, 51.5% F), 28 (14.0%) had pre-existing diagnosis of depression. The mean PHQ9 on discharge was 5.32±5.16 (n=145, deficits too severe to obtain PHQ9 in 55 subjects), with 66 (45.5%) of patients having PHQ9 ≥5 at discharge, indicating at least mild depressive symptoms. While there was no difference in discharge NIHSS or modified Rankin scores, females were twice as likely to experience at least mild depressive symptoms post-stroke as compared to males (66.7% vs 33.3%, p=0.002). Only 19 patients with PHQ9≥5 at discharge were started or continued on antidepressants. On subgroup analysis of patients with PHQ9 ≥5 (n=66), the three most common locations of stroke, in descending order were right parietal (20, 30.3%), left subcortical (14, 21.2%) and right frontal (13, 19.6%). No association was found between discharge PHQ9 score and follow up appointment adherence.

Conclusion: Discharge PHQ9 scores irrespective of treatment do not play a predictive role in follow up appointment adherence. Females were more likely than males to experience post stroke depression; and while depressive symptoms are common, patients were unlikely to be prescribed antidepressant therapy. The most common location of stroke associated with depression was right parietal lobe. Such patients should be assessed closely for symptoms of depression with standardized screening tools.

Abstract WP220: Can’t Breathe, Can’t See, Can’t Think: Chronic Obstructive Pulmonary Disease Increases the Risk of Posterior Reversible Encephalopathy Syndrome

Introduction: Several theories exist regarding the pathogenesis of posterior reversible encephalopathy syndrome (PRES). One theory suggests that PRES occurs when systemic blood pressure exceeds the upper limit of cerebral autoregulation. Endothelial dysfunction has been proposed as an alternative pathogenesis to account for PRES outside the setting of acute hypertension. This mechanism has been implicated in other conditions associated with PRES including autoimmune diseases, cytotoxic medications, sepsis, and eclampsia. The purpose of this study was to determine if COPD, a disease known to cause endothelial dysfunction, has a causative association with the development of PRES.

Methods: A single center retrospective, age-matched, case-control study was performed from January 2013 to June 2019 comparing patients discharged with a primary diagnosis of PRES to a control group with acute ischemic stroke. Demographics, medical comorbidities, initial blood pressure, and clinical outcomes were compared between the two groups. For categorical variables, p-values were calculated using χ2 and Fisher’s exact tests. For continuous variables, p-values were calculated using two-sample t-tests. The effect of COPD and acute hypoxic respiratory failure on PRES status was investigated using multivariate logistic regression.

Results: A total of 94 PRES subjects and 109 control subjects were included for analysis. Mean age did not differ between the two groups; however, the PRES group was more likely to be female (78.7% vs. 49.5%, p<0.001). COPD was present in 26.6% (n=25) of cases and 11% (n= 12) of controls (odds ratio 4.12, p=0.003). Occurrence of hypertension did not differ significantly between the two groups (78.0% vs 86.2%). Among patients with PRES in the setting of COPD (n=25), 60% (n=16) did not meet criteria for hypertensive emergency. Controlling for hypertensive emergency status in a multivariate logistic regression analysis, patients with COPD were 3.21 times more likely to develop PRES (p= 0.004).

Conclusions: To our knowledge, very few reports of PRES in the setting of COPD have been described in the literature and no association of PRES and COPD has been defined to date. Our data support the role of COPD as a risk factor in the development of PRES.

P6561Diagnostic yield of implantable loop recorders: a comparison of arrhythmia nurse specialists versus clinicians

Background

Implantable loop recorders (ILR) are recommended in guidelines to determine symptom-rhythm correlation. Arrhythmia Nurse Specialists (ANS) play a critical role in the assessment of such patients. Their effectiveness at risk stratification for ILR implantation is unknown. The ESC 2018 Syncope guidelines recommend more research in this field.

Aim

To evaluate the diagnostic yield of consecutive ILR implants at a tertiary centre over a 2year period and compare ANS versus Clinicians.

Methods

A retrospective study of all patients undergoing ILR implant between April 2016 and April 2018. Data collected included baseline patient demographics, referral source and management changes made by ILR findings.

Results

305 patients had an ILR; median age was 71yrs (interquartile range 52–81), 55% male. Median follow-up time was 15months. Referrals were from general cardiology (GC) = 98 (32%), electrophysiology (EP) = 105 (34%), and ANS-led syncope clinic = 102 (34%). Indications for ILR implant were syncope = 203 (65.9%), palpitation = 21 (6.9%), pre-syncope = 16 (5.2%), cryptogenic stroke = 35 (11.5%) and others 7 (8.9%) (falls, channelopathies). Of the entire cohort, 102 (34.0%) experienced arrhythmias recorded on the ILR that resulted in a change of management. This included: pacemaker implant = 49 (16.1%), complex-device implant = 7 (2.3%), AF=28 (9.2%), SVT=14 (4.6%), VT=1 (0.3%). Of those with a syncope indication (n=203), findings on ILR altered management in 73patients (36.0%) over a median follow-up of 18months; a pacing indication in this syncope group was present in 44 (21.9%) patients (median time to diagnosis: 2.7 months) with 24 receiving a pacemaker indication within 3 months of ILR insertion. ANS had a higher pacemaker implant rate. Overall, an ILR resulted in a diagnostic yield of 34.1% (n=104). Specialist nurse referral resulted in an overall greater trend towards change of management in 38.2% of patients compared with GC (32.7%) and EP (31.0%) (p=0.593 nurse vs. consultant).

Conclusion

The overall diagnostic yield of ILR insertion was 34% in our study. ANS had a trend towards a greater diagnostic yield compared with clinicians, and significantly more pacemaker indications. Our data suggests that ANS patient selection for ILR insertion are at least comparable to clinicians.

Anomalous Electron Dynamics Induced through the Valley Magnetic Domain: A Pathway to Valleytronic Current Processing

An interplay between an applied strain and the Berry curvature reconstruction in the uniaxially strained monolayer MoS₂ is explored that leads to the unbalanced Berry curvatures centered at K and -K points and, eventually, the valley magnetization under an external electric field. This is shown to explain a recent experimental observation of the valley magnetoelectric effect and develop a novel concept of the valley magnetic domain (VMD), i.e., a real-space homogeneous distribution of the valley magnetization. A realization of VMD guarantees a sufficient number of stable valley-polarized carriers, one of the most essential prerequisites of the valleytronics. Furthermore, we discover the anomalous electron dynamics through the VMD activation and achieve a manipulation of the anomalous transverse current perpendicular to the electric field, directly accessible to the signal processing [for instance, the current modulation under the VMD (i.e., the VMD wall) moving and the terahertz current rectification under the VMD switching]. This suggests a concept of VMD for use in providing new physical insight into the valleytronic functionality and its manipulation as a key ingredient of potential device applications.

Abstract TP345: Early Mobilization Following Recombinant Tissue Plasminogen Activator Administration and/or Mechanical Thrombectomy Reduces Length of Stay

Background: Nearly 800,000 strokes occur each year in the United States and are a leading cause of disability. They result in an annual financial burden of roughly $34 billion, which includes hospitalization and rehabilitation thereafter. Despite this cost, data regarding appropriate timing of mobilization follow administration of intravenous recombinant tissue plasminogen activator (rt-PA) is lacking. As value-based payment models drive systems to reduce length of stay (LOS) and cost of care, early mobilization following rt-PA provides a means to achieve those ends in addition to potentially improving outcomes.

Methods: We conducted a retrospective case-control study including all acute ischemic stroke (AIS) patients admitted to a tertiary academic hospital stroke service from November 2017 to July 2018 who received IV rt-PA locally or by drip and ship, and/or underwent mechanical thrombectomy. The control group includes AIS patients from November 2017 to April 1, 2018. Per protocol, controls (Group 1) were maintained on bedrest for 24 hours after receiving IV rt-PA. Beginning April 2, 2018, a total of 88 (Group 2) patients were managed with early mobility protocols stratifying patients for early mobilization based on NIHSS score, presence of severe aphasia, whether they underwent thrombectomy, and their clinical stability.

Results: Among Group 1 (n=109), the mean time from rt-PA bolus to PT/OT assessment was 38 hours 55 minutes, and the average LOS was six days. With delays removed (PT/OT unable to assess due to intubation/sedation), mean time from bolus to assessment was 33 hours 25 minutes (n=101) and average LOS was five days. Following implementation of early mobility protocols in Group 2 (n=81 treated with IV rt-PA), patients had a mean time from bolus to PT/OT assessment of 22 hours 29 minutes, with an average LOS of 4.42 days. With delays removed, mean time from bolus to assessment was 18 hours 10 minutes, with an average LOS of 3.66 days. No adverse events were seen related to early mobilization in Group 2.

Conclusions: These data suggest that early mobilization following IV thrombolysis is safe and results in decreased time to PT/OT evaluation with subsequent reduction in length of stay. Further study is needed to evaluate for potential impacts on outcome.

Abstract TP379: Antithrombotic Bridging in Patients With Acute Ischemic Stroke and Atrial Fibrillation

Introduction: Atrial fibrillation (AF) is the most common cardiac arrhythmia, with a prevalence of 5.9% in those over age 65. AF increases stroke risk 5-fold, causing 1 in 6 acute ischemic strokes (AIS). Stroke from AF carries a higher early mortality and poorer functional outcome, and a risk of recurrent AIS, when compared to ischemic stroke patients in sinus rhythm, of approximately 5% in the first 2-4 weeks. The CHADS2 score is used to estimate stroke risk of non-valvular AF. Anticoagulation is recommended for a score of > 2 unless contraindicated. Controversy exists regarding whether AF patients with AIS should receive parenteral anticoagulation or antiplatelet therapy as a bridging method to oral anticoagulation.

Methods: We conducted a single center retrospective chart review of patients admitted between 6/2011 and 3/2014, with diagnosis of AIS and AF (n=354), as part of quality improvement. Bleeding complications related to bridging therapy and incidence of recurrent stroke were reviewed.

Results: Complications were seen in 24 (13.3%) patients receiving parenteral bridging anticoagulation (n=180, 50.8%), including 14 intracranial and 14 extracranial bleeding events (7.7% each). Multiple bleeding complications were seen in 2.2% (n=4). Bleeding complications were seen in 5.5% (n=9) of patients receiving antiplatelet bridging (n=161, 45.4%), with 4.3% intracranial (n=7) and 1.2% extracranial (n=2) bleeding events. None had more than one bleeding complication. Relative risk for bleeding complications with parenteral anticoagulation versus antiplatelet bridging was 2.38 (CI 1.1426 to 4.9793, p=0.02). Thirteen patients (3.6%) received no bridging and had no bleeding complications. Two patients of 354 (0.5%) had recurrent ischemic events, one each in the parenteral anticoagulation and antiplatelet groups.

Conclusions: Preliminary data does not support bridging with parenteral anticoagulation in AIS and AF due to higher incidence of bleeding complications and low incidence of recurrent AIS. These findings may be related to the limited number of patients included in this study. A future goal is to increase the number of patients reviewed to strengthen the validity of these results.

Suicidality in a 27-year-old Male with Obsessive Compulsive Disorder

This is a case report of a 27-year-old male with obsessive compulsive disorder (OCD) and anxiety who presented to a community hospital with suicidality. OCD is a rare psychiatric disorder characterized by recurrent and intrusive thoughts or obsessions and/or repetitive behaviors aimed at alleviating these thoughts known as compulsions. Management of this condition includes comprehensive evaluation of comorbidities and suicidality along with pharmacotherapy and a specific form of cognitive behavioral therapy (CBT) called exposure and response prevention (EX/RP or ERP). This unique case report highlights the necessity of a thorough and individualized approach to treatment for each patient in order to maximize the outcomes of care.

Effects of halogens on European air-quality

Halogens (Cl, Br) have a profound influence on stratospheric ozone (O₃). They (Cl, Br and I) have recently also been shown to impact the troposphere, notably by reducing the mixing ratios of O₃ and OH. Their potential for impacting regional air-quality is less well understood. We explore the impact of halogens on regional pollutants (focussing on O₃) with the European grid of the GEOS-Chem model (0.25° × 0.3125°). It has recently been updated to include a representation of halogen chemistry. We focus on the summer of 2015 during the ICOZA campaign at the Weybourne Atmospheric Observatory on the North Sea coast of the UK. Comparisons between these observations together with those from the UK air-quality network show that the model has some skill in representing the mixing ratios/concentration of pollutants during this period. Although the model has some success in simulating the Weybourne ClNO₂ observations, it significantly underestimates ClNO₂ observations reported at inland locations. It also underestimates mixing ratios of IO, OIO, I₂ and BrO, but this may reflect the coastal nature of these observations. Model simulations, with and without halogens, highlight the processes by which halogens can impact O₃. Throughout the domain O₃ mixing ratios are reduced by halogens. In northern Europe this is due to a change in the background O₃ advected into the region, whereas in southern Europe this is due to local chemistry driven by Mediterranean emissions. The proportion of hourly O₃ above 50 nmol mol^-1 in Europe is reduced from 46% to 18% by halogens. ClNO₂ from N₂O₅ uptake onto sea-salt leads to increases in O₃ mixing ratio, but these are smaller than the decreases caused by the bromine and iodine. 12% of ethane and 16% of acetone within the boundary layer is oxidised by Cl. Aerosol response to halogens is complex with small (∼10%) reductions in PM_2.5 in most locations. A lack of observational constraints coupled to large uncertainties in emissions and chemical processing of halogens make these conclusions tentative at best. However, the results here point to the potential for halogen chemistry to influence air quality policy in Europe and other parts of the world.

Schottky barrier tuning of the single-layer MoS2 on magnetic metal substrates through vacancy defects and hydrogenation

For the practical device application of the two-dimensional semiconducting MoS₂, it is a critical issue to manipulate the electronic and magnetic properties locally at its contact to the metal electrode. For the tuning of those properties, we have proposed the vacancy-defective 1L-MoS₂ or the hydrogenated 1L-MoS₂ at the metal [Co(0001) or Ni(111)] contacts and performed first-principles electronic structure calculations. By controlling the atomic vacancy defects and the hydrogen coverages, we investigate the Schottky barrier heights and charge and spin transfers at the interface. Our findings provide a physical insight into the practical device design using the two-dimensional MoS₂.

Two-dimensional semiconductors ZrNCl and HfNCl: Stability, electric transport, and thermoelectric properties

Searching for novel two-dimensional (2D) semiconducting materials is a challenging issue. We investigate novel 2D semiconductors ZrNCl and HfNCl which would be isolated to single layers from van der Waals layered bulk materials, i.e., ternary transition-metal nitride halides. Their isolations are unquestionably supported through an investigation of their cleavage energies as well as their thermodynamic stability based on the ab initio molecular dynamics and phonon dispersion calculations. Strain engineering is found to be available for both single-layer (1L) ZrNCl and 1L-HfNCl, where a transition from an indirect to direct band gap is attained under a tensile strain. It is also found that 1L-ZrNCl has an excellent electron mobility of about 1.2 × 10³ cm² V⁻¹ s⁻¹, which is significantly higher than that of 1L-MoS₂. Lastly, it is indicated that these systems have good thermoelectric properties, i.e., high Seebeck coefficient and high power factor. With these findings, 1L-ZrNCl and 1L-HfNCl would be novel promising 2D materials for a wide range of optoelectronic and thermoelectric applications.

Theory and simulation of micropolar fluid dynamics

This paper reviews the fundamentals of micropolar fluid dynamics (MFD), and proposes a numerical scheme integrating Chorin’s projection method and time-centred split method (TCSM) for solving unsteady forms of MFD equations. It has been known that Navier–Stokes equations are incapable of explaining the phenomena at micro and nano scales. On the contrary, MFD can naturally pick up the physical phenomena at micro and nano scales owingto its additional degrees of freedom for gyration. In this study, the analytical and exact solutions of Couette and Hagen–Poiseuille flow are provided. Though this study is limited to the steady flow cases, the unsteady term in the MFD has been taken into account. This present work initiates the development of a general-purpose code of computational micropolar fluid dynamics (CMFD). The discretization scheme in space is demonstrated with nearly second-order accuracy on multiple meshes.

New Method to Determine the Schottky Barrier in Few-Layer Black Phosphorus Metal Contacts

Schottky barrier height and carrier polarity are seminal concepts for a practical device application of the interface between semiconductor and metal electrode. Investigation of those concepts is usually made by a conventional method such as the Schottky-Mott rule, incorporating the metal work function and semiconductor electron affinity, or the Fermi level pinning effect, resulting from the metal-induced gap states. Both manners are, however, basically applied to the bulk semiconductor metal contacts. To explore few-layer black phosphorus metal contacts far from the realm of bulk, we propose a new method to determine the Schottky barrier by scrutinizing the layer-by-layer phosphorus electronic structure from the first-principles calculation combined with the state-of-the-art band unfolding technique. In this study, using the new method, we calculate the Schottky barrier height and determine the contact polarity of Ti, Sc, and Al metal contacts to few-layer (mono-, bi-, tri-, and quadlayer) black phosphorus. This gives a significant physical insight toward the utmost layer-by-layer manipulation of electronic properties of few-layer semiconductor metal contacts.

Contribution of Secreted NADase and Streptolysin O to the Pathogenesis of Epidemic Serotype M1 Streptococcus pyogenes Infections

Streptococcus pyogenes secretes many toxins that facilitate human colonization, invasion, and dissemination. NADase (SPN) and streptolysin O (SLO) are two toxins that play important roles in pathogenesis. We previously showed that increased production of SPN and SLO in epidemic serotype M1 and M89 S. pyogenes strains is associated with rapid intercontinental spread and enhanced virulence. The biological functions of SPN and SLO have been extensively studied using eukaryotic cell lines, but the relative contribution of each of these two toxins to pathogenesis of epidemic M1 or M89 strains remains unexplored. Herein, using a genetically representative epidemic M1 strain and a panel of isogenic mutant derivative strains, we evaluated the relative contributions of SPN and SLO toxins to virulence in mouse models of necrotizing myositis, bacteremia, and skin and soft tissue infection. We found that isogenic mutants lacking SPN, SLO, and both toxins are equally impaired in ability to cause necrotizing myositis. In addition, mutants lacking either SPN or SLO are significantly attenuated in the bacteremia and soft tissue infection models, and the mutant strain lacking production of both toxins is further attenuated. The mutant strain lacking both SPN and SLO production is severely attenuated in ability to resist killing by human polymorphonuclear leukocytes. We conclude that both SPN and SLO contribute significantly to S. pyogenes pathogenesis in these virulence assays.

Recent Internet Use and Associations with Clinical Outcomes among Patients Entering Addiction Treatment Involved in a Web-Delivered Psychosocial Intervention Study

The acceptability and clinical impact of a web-based intervention among patients entering addiction treatment who lack recent internet access are unclear. This secondary analysis of a national multisite treatment study (NIDA Clinical Trials Network-0044) assessed for acceptability and clinical impact of a web-based psychosocial intervention among participants enrolling in community-based, outpatient addiction treatment programs. Participants were randomly assigned to 12 weeks of a web-based therapeutic education system (TES) based on the community reinforcement approach plus contingency management versus treatment as usual (TAU). Demographic and clinical characteristics, and treatment outcomes were compared among participants with recent internet access in the 90 days preceding enrollment (N = 374) and without internet access (N = 133). Primary outcome variables included (1) acceptability of TES (i.e., module completion; acceptability of web-based intervention) and (2) clinical impact (i.e., self-reported abstinence confirmed by urine drug/breath alcohol tests; retention measured as time to dropout). Internet use was common (74 %) and was more likely among younger (18-49 years old) participants and those who completed high school (p < .001). Participants randomized to TES (n = 255) without baseline internet access rated the acceptability of TES modules significantly higher than those with internet access (t = 2.49, df = 218, p = .01). There was a near significant interaction between treatment, baseline abstinence, and internet access on time to dropout (χ ²(1) = 3.8089, p = .051). TES was associated with better retention among participants not abstinent at baseline who had internet access (X ²(1) = 6.69, p = .01). These findings demonstrate high acceptability of this web-based intervention among participants that lacked recent internet access.

Caenorhabditis elegans glutamylating enzymes function redundantly in male mating

Microtubule glutamylation is an important modulator of microtubule function and has been implicated in the regulation of centriole stability, neuronal outgrowth and cilia motility. Glutamylation of the microtubules is catalyzed by a family of tubulin tyrosine ligase-like (TTLL) enzymes. Analysis of individual TTLL enzymes has led to an understanding of their specific functions, but how activities of the TTLL enzymes are coordinated to spatially and temporally regulate glutamylation remains relatively unexplored. We have undertaken an analysis of the glutamylating TTLL enzymes in C. elegans. We find that although all five TTLL enzymes are expressed in the embryo and adult worm, loss of individual enzymes does not perturb microtubule function in embryonic cell divisions. Moreover, normal dye-filling, osmotic avoidance and male mating behavior indicate the presence of functional amphid cilia and male-specific neurons. A ttll-4(tm3310); ttll-11(tm4059); ttll-5(tm3360) triple mutant, however, shows reduced male mating efficiency due to a defect in the response step, suggesting that these three enzymes function redundantly, and that glutamylation is required for proper function of the male-specific neurons.

Summary: Although mutations in individual microtubule glutamylating enzymes do not disrupt essential microtubule functions in C. elegans, combining mutations in three enzymes uncovers a redundant function for glutamylation in male mating.

Advanced Practice Provider Utilization in the Neurocritical Care Unit

This article discusses the role of advanced practice providers (APPs) in the interprofessional team management of patients with critical neurologic illnesses and how this role has evolved through the years. There is increasing demand for these types of practitioners, formerly termed midlevel providers. Furthermore, the use of APPs appears to have a positive impact on patient satisfaction, reduced costs, and reduced length of stays.

Rectifying the Optical-Field-Induced Current in Dielectrics: Petahertz Diode

Investigating a theoretical model of the optical-field-induced current in dielectrics driven by strong few-cycle laser pulses, we propose an asymmetric conducting of the current by forming a heterojunction made of two distinct dielectrics with a low hole mass (m_{h}^{*}≪m_{e}^{*}) and low electron mass (m_{e}^{*}≪m_{h}^{*}), respectively. This proposition introduces the novel concept of a petahertz (10^{15}  Hz) diode to rectify the current in the petahertz domain, which should be a key ingredient for the electric signal manipulation of future light-wave electronics. Further, we suggest the candidate dielectrics for the heterojunction.

Abstract W P124: Atherosclerosis Of The Circle Of Willis Is Strongly Associated With Downstream Cerebral Amyloid Angiopathy In Parenchymal Arterioles And Capillaries: Possible Mechanism For Atherosclerosis-related Intracranial Hemorrhage

Introduction: Atherosclerosis is highly associated with risk for intracranial hemorrhage. Presumed mechanisms include artery to artery embolization, arteriolar disruption by small vessel atherosclerosis, aberrant angiogenesis in poorly perfused vascular beds, and possible involvement of downstream cerebral amyloid angiopathy (CAA). Direct associations between atherosclerosis and downstream CAA have been not been supported in most studies, however these results may be confounded by the distinction between highly prevalent meningeal CAA and less frequent parenchymal CAA.

Hypothesis: We hypothesized that large vessel intracranial atherosclerosis would be associated with downstream parenchymal, but not meningeal (supplied by extracranial circulation), CAA.

Methods: Data were derived from the University of Kentucky brain bank (n=741). Atherosclerosis of the circle of Willis was graded on semiquantitative scale (1=0-25% occlusion; 2=25-50% occlusion; 3=50-75% occlusion; 4=75-100% occlusion). Cases were divided into those with absent (with or without meningeal CAA; n=493) and those with parenchymal CAA (n=248). Standard descriptive and comparative statistics were used for the analysis.

Results: Atherosclerosis in the circle of Willis was highly associated with parenchymal (p<0.001), but not meningeal CAA.

Conclusions: The strong association seen between severity of atherosclerosis and parenchymal CAA suggests possible shared pathogenesis or perhaps causal development of CAA by high grade atherosclerosis. Further studies exploring this association in animal models would be helpful in clarifying this complex relationship.

Abstract T MP111: Cerebral Amyloid Angiopathy Is Associated With Arteriolar Sclerosis And Microinfarcts, But Not Overt Ischemic Stroke Or Hemorrhage In A Large Autopsy Series

Introduction: Cerebral amyloid angiopathy (CAA) has been associated with various types of cerebrovascular pathology independent of Alzheimer’s disease (AD), including atherosclerosis, arteriosclerosis, ischemic and hemorrhagic infarction. Available studies have frequently produced conflicting results in regards to specific cerebrovascular associations, likely due to confounds of subject selection biases, small sample sizes, and incomplete pathologic analyses. The present study represents one of the largest and most comprehensive clinical-pathologic series to date focused on examining clinical, genetic, and pathologic associations in CAA.

Hypothesis: As CAA represents a vasculopathy of the small arterioles and capillaries, we hypothesized that cerebrovascular associations with CAA would include small vessel pathologies and microinfarcts rather than large or medium vessel pathologies.

Methods: Cases were derived from the University of Kentucky brain bank (n=741). Vascular pathology was graded on semiquantitative scale or as present/absent. Cases were grouped by presence (n=414) or absence of CAA (n=327). Standard descriptive and comparative statistics were used for the analysis.

Results: ApoE status (p<0.001), but not age, was associated with CAA. Cases with and without CAA did not differ in regards to large vessel or lacunar ischemic stroke, hemorrhagic stroke, hippocampal sclerosis, or circle of Willis atherosclerosis. A significant increase in arteriolar sclerosis (p<0.001) and microinfarct burden (p<0.01) was seen in the CAA-positive group.

Conclusions: CAA across the cognitive continuum, appears independent of age, and is a significant contributor to small vessel ischemic changes that may have a profound effect on brain health, including risk for stroke and cognitive impairment. Comprehensive treatment strategies for small vessel ischemic disease need to acknowledge and potentially address the role of CAA as therapeutic treatments for this unique vasculopathy become available in the future.

Communication challenges in complex medical environments

The provision of health care is becoming increasingly complex and can involve multiple providers and care setting transitions, particularly as the population is living longer, and often with chronic disease. The Electronic Health Record (EHR) was intended to provide a comprehensive documentation of a patient's health-related information; however, health care systems often function in isolation with EHRs that are unique only to that system. The EHR may also limit face-to-face communication between treating physicians within the same system. It is only with diligent effort that changes in medical management plans are conveyed among providers. When multiple providers are involved in a patient's care, physician-to-patient communication may also suffer, which can impact patient satisfaction and outcome. This article describes a scenario in which several lapses in communication occurred, and it outlines other common pitfalls while providing possible solutions for improving communication across the health care spectrum.

A phase I/IIa study on intra-articular injection of holmium-166-chitosan complex for the treatment of knee synovitis of rheumatoid arthritis

Previous animal studies have established that the intra-articular injection of holmium-166-chitosan complex (DW-166HC) causes effective necrosis of the inflamed synovium with litle leakage of radioactivity from the injected joint. Based on these findings, we conducted a phase I/IIa study to examine the biodistribution of DW-166HC and to assess the safety of DW-166HC for the treatment of knee synovitis in patients with rheumatoid arthritis (RA). A total of 16 patients [1 man, 15 women; median age 49 (range 36-65) years] who had RA knee synovitis refractory to disease-modifying anti-rheumatic drug treatments of > 3 months' duration were randomly assigned to three treatment groups with different radiation doses of DW-166HC: 370 MBq (n = 6), 555 MBq (n = 5) and 740 MBq (n = 5). In each treatment group, blood and urine radioactivity were analysed by beta counter and biodistribution of the injected DW-166HC was evaluated using a gamma scan camera. Clinical assessment was done according to three variables (evaluation method): knee joint pain (visual analogue scale), range of motion (goniometry) and joint swelling (circumference of knee joint). The duration of follow-up observation was 3 months. Following the intra-articular injection of DW-166HC, the blood radioactivity was little changed from the baseline measurement and the accumulated radioactivity excreted in urine was minimal. Gamma scan study indicated that most of the injected radiochemical was localized within the injected joint cavity, and the extra-articular leakage was negligible at 24 h after the injection: brain, 0.3%; lung, 0.6%; abdomen, 0.7%; and pelvis, 0.8%. Major adverse events were transient post-injection knee joint pain and swelling. These results suggest that DW-166HC might be a safe agent for radiation synovectomy, particularly for the treatment of knee synovitis of RA, and further trials in a larger patient population are warranted to evaluate the therapeutic efficacy of DW-166HC.

Abstract T P296: Diagnostic Testing in Acute Stroke Patients- The Weekend Waiting Game

Background: Inpatient hospital stays contribute considerable costs to our total healthcare expenditures in the US. Increased lengths of stay can lead to increased costs. At the University of Kentucky, there appears to be delays in care in patients admitted over the weekend compared to those who are admitted during weekdays, due to availability of certain testing, such as MRI and transthoracic echocardiogram. This may lead to delays in delivering appropriate care, increase in length of stay, and possibly costs.

Methods: We retrospectively reviewed charts for patients admitted to the University of Kentucky Chandler Medical Center between September to November 2012. Patients were divided into two groups based on the day of the week tests were ordered. Group 1 included patients on whom MRI or echocardiogram was ordered between Monday through Thursday. Group 2 included patients on whom tests were ordered Friday through Sunday. Results were compared using the two sample t-test.

Results: A total of 275 MRIs were performed on stroke patients. For Group 1 (n=168) procedures, mean time to completion was 13.2 hours +/- SD 12.6. For Group 2 (n=97), the mean time to completion was 20.7 hours +/- SD 19.5 (p=.002). A total of 272 echocardiograms were performed. For group 1 (n=171), mean time to completion was 17.4 hours +/- SD 11.2. For Group 2 (n=97), the mean time to completion was 33.4 hours +/- SD 21.6, (p<.0001).

Conclusion: There was a 57% increase in the time needed to complete MRI and 92% increase in the time needed to complete echocardiogram when it was ordered on the weekend. This represents a significant delay in care and may impact lengths of stay. The hiring of additional MRI and echocardiogram technicians could reduce delays in patient care and lengths of stay. This in turn may reduce costs for both patients and the system.

Effects of eplerenone on the activation of matrix metalloproteinase-2 stimulated by high glucose and interleukin-1β in human cardiac fibroblasts

The aim of this study was to determine the influence of high glucose (HG) and interleukin (IL)-1β on human cardiac fibroblast (HCF) functions, and to evaluate the effects of eplerenone in these responses. HCFs were cultured in normal or HG media in the absence or presence of IL-1β and/or eplerenone. We assessed matrix metalloproteinase-2 (MMP-2) activity in the supernatant by in-gel zymography, and determined mRNA expression levels of MMP-2 and tissue inhibitor of metalloproteinase-2 (TIMP-2) by reverse transcription-polymerase chain reaction. Equimolar D-mannitol was used as an osmotic control. HG stimulated MMP-2 activity and promoted MMP-2 mRNA synthesis. Increased effects were also observed in equimolar D-mannitol treatments, but these effects were weaker compared to those of glucose. The combination of HG and IL-1β resulted in a 2-fold increase in MMP-2 activity and mRNA expression compared with HG or IL-1β alone. Increases in HG- or IL-1β-induced MMP-2 activity and mRNA expression were blocked by eplerenone. Neither HG nor IL-1β affected TIMP-2 mRNA expression. HG increased MMP-2 activity by regulation of MMP- 2 mRNA expression in HCFs through osmotic and non-osmotic pathways. Synergistic effects of IL-1β added to HG media on MMP-2 activity and mRNA expression were observed in HCFs. Eplerenone normalized the effect of MMP-2 activity and HG- or IL-1β-induced expression in HCFs.

Model for the attosecond resonant photoemission of copper dichloride: evidence for high-order Fano resonances and a time-domain core-hole clock

We present a model of the attosecond resonant dynamics of valence electron photoemission and MMM Auger electron emission in copper dichloride. At τ(h)≫1/ω(IR) (where τ(h) is the core-hole relaxation time and ω(IR) is the energy of the infrared probe field), high-order Fano sideband resonances on both sides of the original (zeroth-order) resonance are found in the energy domain on the time scale of τ(h). This is confirmed by a coherent π rotation of the relative phase between the photoelectron and Auger electron at each resonance, due to the subfemtosecond quantum correlation. We also find a core-hole clock, the asymmetry factor q of the first-order Fano sideband resonance, which can directly trace the core-hole relaxation in the time domain.

Specialty and Associate Specialist doctors: still the dependable backbone of genitourinary medicine

Workforce planning is an inexact science. Specialty and Associate Specialist (SAS) doctors are rarely included in workforce analyses. Past studies have shown that SAS doctors are significant contributors to the work in genitourinary (GU) medicine clinics. This survey confirms the large amount of clinical work undertaken by SAS doctors. It appears that 51% of SAS doctors in GU plan to retire in the next 15 years and it is uncertain what effect the 2008 SAS contract will have on SAS recruitment. This information should be taken into consideration in future GUM workforce planning.

Controlling ferromagnetic easy axis in a layered MoS2 single crystal

We report the effective methods to induce weak ferromagnetism in pristine MoS2 persisting up to room temperature with the improved transport property, which would lead to new spintronics devices. The hydrogenation of MoS2 by heating at 300 °C for 1 h leads to the easy axis out of plane, while the irradiation of proton with a dose of 1 × 10(13) P/cm(2) leads to the easy axis in plane. The theoretical modeling supports such magnetic easy axes.

Multiannual observations of acetone, methanol, and acetaldehyde in remote tropical atlantic air: implications for atmospheric OVOC budgets and oxidative capacity

Oxygenated volatile organic compounds (OVOCs) in the atmosphere are precursors to peroxy acetyl nitrate (PAN), affect the tropospheric ozone budget, and in the remote marine environment represent a significant sink of the hydroxyl radical (OH). The sparse observational database for these compounds, particularly in the tropics, contributes to a high uncertainty in their emissions and atmospheric significance. Here, we show measurements of acetone, methanol, and acetaldehyde in the tropical remote marine boundary layer made between October 2006 and September 2011 at the Cape Verde Atmospheric Observatory (CVAO) (16.85° N, 24.87° W). Mean mixing ratios of acetone, methanol, and acetaldehyde were 546 ± 295 pptv, 742 ± 419 pptv, and 428 ± 190 pptv, respectively, averaged from approximately hourly values over this five-year period. The CAM-Chem global chemical transport model reproduced annual average acetone concentrations well (21% overestimation) but underestimated levels by a factor of 2 in autumn and overestimated concentrations in winter. Annual average concentrations of acetaldehyde were underestimated by a factor of 10, rising to a factor of 40 in summer, and methanol was underestimated on average by a factor of 2, peaking to over a factor of 4 in spring. The model predicted summer minima in acetaldehyde and acetone, which were not apparent in the observations. CAM-Chem was adapted to include a two-way sea-air flux parametrization based on seawater measurements made in the Atlantic Ocean, and the resultant fluxes suggest that the tropical Atlantic region is a net sink for acetone but a net source for methanol and acetaldehyde. Inclusion of the ocean fluxes resulted in good model simulations of monthly averaged methanol levels although still with a 3-fold underestimation in acetaldehyde. Wintertime acetone levels were better simulated, but the observed autumn levels were more severely underestimated than in the standard model. We suggest that the latter may be caused by underestimated terrestrial biogenic African primary and/or secondary OVOC sources by the model. The model underestimation of acetaldehyde concentrations all year round implies a consistent significant missing source, potentially from secondary chemistry of higher alkanes produced biogenically from plants or from the ocean. We estimate that low model bias in OVOC abundances in the remote tropical marine atmosphere may result in up to 8% underestimation of the global methane lifetime due to missing model OH reactivity. Underestimation of acetaldehyde concentrations is responsible for the bulk (∼70%) of this missing reactivity.

Use of the Penumbra system 054 plus low dose thrombolytic infusion for multifocal venous sinus thrombosis. A report of two cases

Multifocal cerebral venous sinus thrombosis (CVST) has a high mortality rate especially when patients present with stupor or coma. Medical treatment including anticoagulation raises concerns about the associated high risk of intracerebral hemorrhage. Treatment of multifocal CVST with mechanical thrombectomy devices and local tPA infusion have previously been reported. However, these devices may have technical limitations. Success of the new-generation aspiration thrombectomy device like the Penumbra system has been reported in few cases of isolated CVST without the use of chemical thrombolysis. We describe two cases in which mechanical thrombectomy were used in conjunction with intra-sinus tPA infusion. Both cases were complicated and failed initial anticoagulation. Penumbra 054 was used in both cases. The Penumbra 054 is a novel device that has a bigger lumen which provides compatibility with other microcatheters, if additional therapies are required. The larger internal diameter of this catheter also allows for stronger thrombo-aspiration, potentially effecting more rapid sinus recanalization. Both cases showed remarkable clinical recovery without any major complications. This is the first reported simultaneous use of the Penumbra system 054 along with tPA infusion. New devices such as the Penumbra system may offer additional therapeutic options in the treatment of multifocal CVST.

Impairments to the GH-IGF-I axis in hSOD1G93A mice give insight into possible mechanisms of GH dysregulation in patients with amyotrophic lateral sclerosis

GH deficiency has been found in subjects with amyotrophic lateral sclerosis (ALS). Disrupted endocrine function could contribute to the progressive muscle loss and hypermetabolism seen in ALS. It is not possible to study all the elements of the GH-IGF-I axis in ALS patients. Consequently, it remains unclear whether dysfunctional GH secretion contributes to disease pathogenesis and why GH and IGF-I directed treatment strategies are ineffective in human ALS. The hSOD1(G93A) transgenic mouse model is useful for the detailed investigation of the pathogenesis of ALS. We report that symptomatic male hSOD1(G93A) transgenic mice exhibit a deficiency in GH secretion similar to that seen in human ALS. Further characterization of the GH-IGF-I axis in hSOD1(G93A) mice reveals central and peripheral abnormalities that are not found in wild-type age-matched controls. Specifically, we observe aberrant endogenous pulsatile GH secretion, reduced pituitary GH content, and decreased circulating levels of IGF-I, indicating global GH deficiency in hSOD1(G93A) mice. Furthermore, a reduction in the expression of the IGF-I receptor α-subunit in skeletal muscle and lumbar spinal cords of hSOD1(G93A) mice suggests impaired IGF-I signaling within these tissues. This is the first account of disrupted GH secretion in a transgenic mouse model of ALS. These observations are essential for the development of effective GH and IGF-I targeted therapies in ALS.

The atmospheric chemistry of trace gases and particulate matter emitted by different land uses in Borneo

We report measurements of atmospheric composition over a tropical rainforest and over a nearby oil palm plantation in Sabah, Borneo. The primary vegetation in each of the two landscapes emits very different amounts and kinds of volatile organic compounds (VOCs), resulting in distinctive VOC fingerprints in the atmospheric boundary layer for both landscapes. VOCs over the Borneo rainforest are dominated by isoprene and its oxidation products, with a significant additional contribution from monoterpenes. Rather than consuming the main atmospheric oxidant, OH, these high concentrations of VOCs appear to maintain OH, as has been observed previously over Amazonia. The boundary-layer characteristics and mixing ratios of VOCs observed over the Borneo rainforest are different to those measured previously over Amazonia. Compared with the Bornean rainforest, air over the oil palm plantation contains much more isoprene, monoterpenes are relatively less important, and the flower scent, estragole, is prominent. Concentrations of nitrogen oxides are greater above the agro-industrial oil palm landscape than over the rainforest, and this leads to changes in some secondary pollutant mixing ratios (but not, currently, differences in ozone). Secondary organic aerosol over both landscapes shows a significant contribution from isoprene. Primary biological aerosol dominates the super-micrometre aerosol over the rainforest and is likely to be sensitive to land-use change, since the fungal source of the bioaerosol is closely linked to above-ground biodiversity.

The impact of local surface changes in Borneo on atmospheric composition at wider spatial scales: coastal processes, land-use change and air quality

We present results from the OP3 campaign in Sabah during 2008 that allow us to study the impact of local emission changes over Borneo on atmospheric composition at the regional and wider scale. OP3 constituent data provide an important constraint on model performance. Treatment of boundary layer processes is highlighted as an important area of model uncertainty. Model studies of land-use change confirm earlier work, indicating that further changes to intensive oil palm agriculture in South East Asia, and the tropics in general, could have important impacts on air quality, with the biggest factor being the concomitant changes in NO(x) emissions. With the model scenarios used here, local increases in ozone of around 50 per cent could occur. We also report measurements of short-lived brominated compounds around Sabah suggesting that oceanic (and, especially, coastal) emission sources dominate locally. The concentration of bromine in short-lived halocarbons measured at the surface during OP3 amounted to about 7 ppt, setting an upper limit on the amount of these species that can reach the lower stratosphere.

Abstract 3763: Impact Of Race And Ethnicity On Stroke Risk Factors And Care: Echocardiographic Risk Stratification And Discharge Disposition

Background: Hispanic Americans (HA) and African Americans (AA) are known to have greater incidence of stroke and may have more severe deficits than non-Hispanic whites (NHW). AA and HA are known to have higher incidences of hypertension compared to NHW. Little has been published on the use of echocardiography to determine racial and ethnic distribution of risk factors Recently published information indicates that while minorities have equal access to rehabilitative services, minorities with stroke have longer hospital stays and poorer functional outcomes compared to NHW, leading to potential increased healthcare needs post-discharge.

Hypothesis: We hypothesize that HA and AA are more likely than NHW to have evidence of hypertensive pathology on echocardiographic evaluation. We further hypothesize that HA, due to social and cultural differences, are more likely to discharge home and less likely than AA and NHW to utilize skilled nursing facilities (SNF) or long term acute care facilities (LTAC).

Methods: We conducted a retrospective chart review of patients at a single institution with a diagnosis of TIA, ischemic or hemorrhagic stroke admitted from January 2004 to January 2007 (N=1480). Demographic information, co-morbid conditions, diagnostic test results, and information regarding discharge were collected. We used descriptive statistics to characterize the groups, and association between ethnicity and echocardiogram evaluation and discharge disposition was tested by Chi-square analysis.

Results: TTE and TEE were used equally across ethnic groups. AA had more evidence of hypertensive pathology on echocardiographic imaging compared to NHW and HA (95% vs. 43% and 40%, respectively, p<.001). Unexpectedly, HA were more likely to have potential embolic sources found on echocardiographic studies compared to NHW or AA (68% vs. 38% and 44% respectively, p<.001). HA were less likely to discharge to SNF or LTAC compared to NHW or AA (2% vs. 7% for both NHW and AA, p<.001). There was no difference in the likelihood of discharge to SNF or LTAC between AA and NHW.

Conclusions: HA have more embolic sources as a potential cause for stroke compared to either NHW or AA. This may have impact on the diagnostic utilization of TTE and TEE. Hypertensive echochardiographic changes are common in AA, emphasizing the need for primary prevention. HA are more likely to discharge home, rather than to a SNF or LTAC facility. This finding may indicate a need for additional home care services and education regarding home care of stroke patients for this population.

Influence of aerobic cycle exercise training on patellar tendon cross-sectional area in older women

Nine to 12 weeks of resistance exercise training in young individuals induces quadriceps muscle (∼6%) and region-specific patellar tendon (4-6%) hypertrophy. However, 12 weeks of resistance exercise training (∼1 h total exercise time) in older individuals (60-78 years) induces quadriceps muscle hypertrophy (9%) without impacting patellar tendon size. The current study examined if a different loading paradigm using cycle exercise would promote patellar tendon hypertrophy or alter the internal tendon properties, measured with magnetic resonance imaging signal intensity, in older individuals. Nine women (70 ± 2 years) completed 12 weeks of aerobic upright cycle exercise training (∼28 h total exercise time). Aerobic exercise training increased (P < 0.05) quadriceps muscle size (11 ± 2%) and VO2max (30 ± 9%). Mean patellar tendon cross-sectional area (CSA) (2 ± 1%) and signal intensity (-1 ± 2%) were unchanged (P > 0.05) over the 12 weeks of training. Region-specific CSA was unchanged (P > 0.05) at the proximal (-1 ± 3%) and mid regions (2 ± 2%) of the tendon but tended (P = 0.069) to increase at the distal region (5 ± 3%). Region-specific signal intensity differed along the tendon but was unchanged (P > 0.05) with training. Although more studies are needed, exercise-induced patellar tendon hypertrophy, compared with skeletal muscle, appears to be attenuated in older individuals, while the loading pattern associated with aerobic exercise seems to have more impact than resistance exercise in promoting patellar tendon hypertrophy.

Neuroanatomic basis of amnestic MCI differs in patients with and without Parkinson disease

OBJECTIVE

To explore the neuroanatomic basis of amnestic mild cognitive impairment (aMCI) in patients with Parkinson disease (PD; aMCI-PD(+)) and without PD (aMCI-PD(-)).

METHODS

A total of 119 patients with aMCI (aMCI-PD(-), n = 78, and aMCI-PD(+), n = 41) underwent T1-weighted MRI, and the image data were analyzed using voxel-based morphometry.

RESULTS

No significant differences in demographic characteristics or general cognition were found between patients with aMCI-PD(-) and aMCI-PD(+). Comparisons of neuropsychological tests between groups revealed that patients with aMCI-PD(-) had lower scores in delayed verbal and visual recognition memory, whereas visuospatial dysfunction was more severe in patients with aMCI-PD(+). Gray matter (GM) density in the right temporal and posterior cingular cortices was significantly lower in the aMCI-PD(-) group compared with controls. In contrast, GM density in the aMCI-PD(+) group was significantly lower in the precuneus and left prefrontal and primary motor areas relative to controls. A direct comparison between groups showed that decreased GM density in aMCI-PD(-) relative to aMCI-PD(+) was localized in the right temporal and anterior prefrontal areas, whereas decreased GM density in aMCI-PD(+) relative to aMCI-PD(-) was involved in the bilateral precuneus, left primary motor, and right parietal areas. Memory decline was correlated with temporal area atrophy in aMCI-PD(-) and with posterior cingulate cortex atrophy in aMCI-PD(+).

CONCLUSIONS

Our data suggest that different neuroanatomic systems underlie memory dysfunction in patients with aMCI-PD(-) and aMCI-PD(+).

An unusual testicular lump

A 32-year-old British Asian man presented with what appeared clinically and on ultrasound to be a testicular tumour. However, syphilis serology, histology and detection of Treponema pallidum DNA by polymerase chain reaction confirmed that the lesion was a gumma. Without routine syphilis serology, the correct diagnosis may have been missed.

Immunosuppression during influenza virus infection

The effects of a live attenuated influenza vaccine and subsequent challenge with virulent influenza virus on the delayed hypersensitivity skin test, and the in vitro response of lymphocytes were evaluated. Volunteers were skin tested before and after administration of vaccine or placebo and challenge with PPD (a purified protein derivative of Mycobacterium tuberculosis), candida, mumps, and trichophytin, and their lymphocytes were tested for [(3)H]thymidine uptake in response to phytohemagglutin. Of eight volunteers who showed evidence of viral replication after administration of the attenuated vaccine, four had a significant diminution in their skin test response, whereas 8 of 13 volunteers infected with virulent influenza virus showed a diminution. Of the 21 volunteers who were infected with either attenuated or virulent influenza virus, 12 showed suppression of their phytohemagglutin response. None of the volunteers who were given placebo vaccine, or who showed no evidence for viral replication after immunization or challenge, had a suppression of their skin test or phytohemagglutin responses. Although most of the infected volunteers demonstrated suppression of their T-cell function, there was no evidence of a similar suppression of B-cell function.