Diffusion-Weighted Imaging Fluid-Attenuated Inversion Recovery Mismatch on Portable, Low-Field Magnetic Resonance Imaging Among Acute Stroke Patients

OBJECTIVE

For stroke patients with unknown time of onset, mismatch between diffusion-weighted imaging (DWI) and fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) can guide thrombolytic intervention. However, access to MRI for hyperacute stroke is limited. Here, we sought to evaluate whether a portable, low-field (LF)-MRI scanner can identify DWI-FLAIR mismatch in acute ischemic stroke.

METHODS

Eligible patients with a diagnosis of acute ischemic stroke underwent LF-MRI acquisition on a 0.064-T scanner within 24 h of last known well. Qualitative and quantitative metrics were evaluated. Two trained assessors determined the visibility of stroke lesions on LF-FLAIR. An image coregistration pipeline was developed, and the LF-FLAIR signal intensity ratio (SIR) was derived.

RESULTS

The study included 71 patients aged 71 ± 14 years and a National Institutes of Health Stroke Scale of 6 (interquartile range 3-14). The interobserver agreement for identifying visible FLAIR hyperintensities was high (κ = 0.85, 95% CI 0.70-0.99). Visual DWI-FLAIR mismatch had a 60% sensitivity and 82% specificity for stroke patients <4.5 h, with a negative predictive value of 93%. LF-FLAIR SIR had a mean value of 1.18 ± 0.18 <4.5 h, 1.24 ± 0.39 4.5-6 h, and 1.40 ± 0.23 >6 h of stroke onset. The optimal cut-point for LF-FLAIR SIR was 1.15, with 85% sensitivity and 70% specificity. A cut-point of 6.6 h was established for a FLAIR SIR <1.15, with an 89% sensitivity and 62% specificity.

INTERPRETATION

A 0.064-T portable LF-MRI can identify DWI-FLAIR mismatch among patients with acute ischemic stroke. Future research is needed to prospectively validate thresholds and evaluate a role of LF-MRI in guiding thrombolysis among stroke patients with uncertain time of onset. ANN NEUROL 2024.

Considering Adverse Effects of Common Antihypertensive Medications in the ED

PURPOSE OF REVIEW

To evaluate the adverse effects of common antihypertensive agents utilized or encountered in the Emergency Department.

RECENT FINDINGS

All categories of antihypertensive agents may manifest adverse effects, inclusive of adverse drug reactions (ADRs), drug-to-drug interactions, or accidental overdose. Adverse effects, and specifically ADRs, may be stratified into the organ systems affected, might require specific time-sensitive interventions, could pose particular risks to vulnerable populations, and may result in significant morbidity, and potential mortality. Adverse effects of common antihypertensive agents may be encountered in the ED, necessitating that ED systems of care are poised to prevent, recognize, and intervene when adverse effects arise.

Aging dysregulates neutrophil extracellular trap formation in response to HIV in blood and genital tissues

Women acquire HIV through sexual transmission, with increasing incidence in women >50 years old. Identifying protective mechanisms in the female genital tract (FGT) is important to prevent HIV-acquisition in women as they age. Human genital and blood neutrophils inactivate HIV by releasing neutrophil extracellular traps (NETs), an innate protective mechanism against HIV-infection. However, how NET formation is triggered by HIV in different tissues and whether this mechanism is affected by aging remain unknown. We demonstrate that the mechanisms that trigger NET release in response to HIV are different in blood and genital tissues, and that NET release decreases with aging. In blood neutrophils, HIV stimulation independently activated calcium pathways and endosomal TLR8, but aging reduced calcium responses, resulting in delayed NET release. In contrast, calcium responses were absent in genital neutrophils and NET release was triggered preferentially through TLR8 activation, but aging impaired this pathway. HIV induced NET formation through non-lytic pathways in blood and FGT neutrophils, except for a small subset of NETs that incorporated annexin V and lactoferrin predominantly in blood, suggesting proinflammatory and lytic NET release. Our findings demonstrate that blood neutrophils cannot model genital neutrophil responses which has important implications to understanding protection against HIV acquisition.

Aging modifies endometrial dendritic cell function and unconventional double negative T cells in the human genital mucosa

BACKGROUND

Immune function in the genital mucosa balances reproduction with protection against pathogens. As women age, genital infections, and gynecological cancer risk increase, however, the mechanisms that regulate cell-mediated immune protection in the female genital tract and how they change with aging remain poorly understood. Unconventional double negative (DN) T cells (TCRαβ + CD4-CD8-) are thought to play important roles in reproduction in mice but have yet to be characterized in the human female genital tract. Using genital tissues from women (27-77 years old), here we investigated the impact of aging on the induction, distribution, and function of DN T cells throughout the female genital tract.

RESULTS

We discovered a novel site-specific regulation of dendritic cells (DCs) and unconventional DN T cells in the genital tract that changes with age. Human genital DCs, particularly CD1a + DCs, induced proliferation of DN T cells in a TFGβ dependent manner. Importantly, induction of DN T cell proliferation, as well as specific changes in cytokine production, was enhanced in DCs from older women, indicating subset-specific regulation of DC function with increasing age. In human genital tissues, DN T cells represented a discrete T cell subset with distinct phenotypical and transcriptional profiles compared to CD4 + and CD8 + T cells. Single-cell RNA and oligo-tag antibody sequencing studies revealed that DN T cells represented a heterogeneous population with unique homeostatic, regulatory, cytotoxic, and antiviral functions. DN T cells showed relative to CD4 + and CD8 + T cells, enhanced expression of inhibitory checkpoint molecules and genes related to immune regulatory as well as innate-like anti-viral pathways. Flow cytometry analysis demonstrated that DN T cells express tissue residency markers and intracellular content of cytotoxic molecules. Interestingly, we demonstrate age-dependent and site-dependent redistribution and functional changes of genital DN T cells, with increased cytotoxic potential of endometrial DN T cells, but decreased cytotoxicity in the ectocervix as women age, with implications for reproductive failure and enhanced susceptibility to infections respectively.

CONCLUSIONS

Our deep characterization of DN T cell induction and function in the female genital tract provides novel mechanistic avenues to improve reproductive outcomes, protection against infections and gynecological cancers as women age.

Diagnosis, Workup, Risk Reduction of Transient Ischemic Attack in the Emergency Department Setting: A Scientific Statement From the American Heart Association

At least 240 000 individuals experience a transient ischemic attack each year in the United States. Transient ischemic attack is a strong predictor of subsequent stroke. The 90-day stroke risk after transient ischemic attack can be as high as 17.8%, with almost half occurring within 2 days of the index event. Diagnosing transient ischemic attack can also be challenging given the transitory nature of symptoms, often reassuring neurological examination at the time of evaluation, and lack of confirmatory testing. Limited resources, such as imaging availability and access to specialists, can further exacerbate this challenge. This scientific statement focuses on the correct clinical diagnosis, risk assessment, and management decisions of patients with suspected transient ischemic attack. Identification of high-risk patients can be achieved through use of comprehensive protocols incorporating acute phase imaging of both the brain and cerebral vasculature, thoughtful use of risk stratification scales, and ancillary testing with the ultimate goal of determining who can be safely discharged home from the emergency department versus admitted to the hospital. We discuss various methods for rapid yet comprehensive evaluations, keeping resource-limited sites in mind. In addition, we discuss strategies for secondary prevention of future cerebrovascular events using maximal medical therapy and patient education.

Aging beyond menopause selectively decreases CD8+ T cell numbers but enhances cytotoxic activity in the human endometrium

BACKGROUND

Regulation of endometrial (EM) CD8+ T cells, which provide protection through cell-mediated cytotoxicity, is essential for successful reproduction, and protection against sexually transmitted infections and potential tumors. We have previously demonstrated that EM CD8+ T cell cytotoxicity is suppressed directly and indirectly by sex hormones and enhanced after menopause. What remains unclear is whether CD8+ T cell protection and the contribution of tissue-resident (CD103+) and non-resident (CD103-) T cell populations in the EM change as women age following menopause.

RESULTS

Using hysterectomy EM tissues, we found that EM CD8+ T cell numbers declined significantly in the years following menopause. Despite an overall decline in CD8+ T cells, cytotoxic activity per cell for both CD103- and CD103 + CD8+ T cells increased with age. Investigation of the underlying mechanisms responsible for cytotoxicity indicated that the percentage of total granzyme A and granzyme B positive CD8+ T cells, but not perforin, increased significantly after menopause and remained high and constant as women aged. Additionally, baseline TNFα production by EM CD8+ T cells increased significantly in the years following menopause, and estradiol suppressed TNFα secretion. Moreover, in response to PMA activation, TNFα and IFNγ were significantly up-regulated, and CD103-CD8+ T cells up-regulation of TNFα, IFNγ and IL-6 increased as women aged.

CONCLUSIONS

Understanding the underlying factors involved in regulating cell-mediated protection of the EM by CD8+ T cells will contribute to the foundation of information essential for developing therapeutic tools to protect women against gynecological cancers and infections as they age.

Abstract WMP59: Trends And Predictors Of Delay In Hospital Presentation After Symptom Onset Among Ischemic Stroke Patients: A Single-center Study

Background: Delivery of acute ischemic stroke therapies is contingent on the duration from last known normal (LKN) to emergency department arrival time (EDAT).

Methods: We studied patients presenting to Yale-New Haven Hospital from 2010-2020 who met these criteria 1) ischemic stroke, 2) age ≥ 18, 3) not transferred from another hospital, and 4) stroke symptom onset prior to hospital presentation. The outcome was LKN to EDAT dichotomized at 4.5 hours. Temporal trends were assessed by linear regression. Covariates analyzed for association with later arrival were: age, gender, race, ethnicity, median household income < $50,000 by ZIP, arrival means, and NIHSS. We built a multivariable logistic regression model by stepwise selection with variables significant at p-value < 0.05).

Results: We included 5,242 ischemic stroke patients; 1,964 (37.5%) presented early (<4.5 hrs). Patients presenting early decreased from 47.2% to 32.3% over time (p<0.01, Figure 1 ) and downward slope was steeper among non-White patients. Compared to early presenters, late presenters were more likely younger (median 72 vs 74 years; p<0.001), of non-White race (35.3% vs 26.8%, p<0.001), of Hispanic ethnicity (8.2% vs 6.2%, p=0.010), have a median household income < $50,000 (27.0% vs 21.2%, p=<0.001), arrive by means other than emergency medical services (EMS) (66.4% vs 85.8%, p<0.001), and have an NIHSS < 4 (57.5% vs 41.6%, p<0.001). In a multivariable model, non-White race (OR 1.4, 95% C.I. 1.2-1.7), arrival by means other than EMS (OR 2.4, 95% C.I. 1.9-3.0), and NIHSS < 4 (OR 1.6, 95% C.I. 1.3-1.9) were significant, independent predictors of presenting later.

Conclusion: Frequency of ischemic stroke patients presenting beyond 4.5 hrs increased from 2010 to 2020. Non-White race, arriving by means other than EMS, and minor stroke symptoms were linked with delay in presentation. Further study is necessary to identify and target barriers to timely hospital presentation among ischemic stroke patients.

Abstract WP111: Deployment Of Portable, Bedside, Low-field Magnetic Resonance Imaging In The Emergency Department To Evaluate Patients With Acute Stroke

Background and Aims: MRI is critical for diagnosing acute stroke and guiding candidate selection for potential reperfusion therapy. However, rapid stroke evaluation using MRI is often dissuaded by the time required for patients to travel to access-controlled, high-field (1.5-3T) systems. Advances in low-field MRI enable the acquisition of clinically valuable images at the bedside. We report neuroimaging in patients presenting to the Emergency Department (ED) with stroke symptoms using a low-field portable MRI (pMRI) device.

Methods: A 64mT pMRI device was deployed in the Yale-New Haven Hospital ED from August 2020 to July 2021. Patients presenting as a “Stroke Code” or “Intracranial Hemorrhage Alert” with no MRI contraindications were scanned. Exams were performed at the bedside, in the vicinity of ED room equipment. Research staff acquired imaging via tablet, with images available immediately after acquisition. Sequences obtained and axial scan times (in minutes) included T1-weighted imaging (4:54), T2-weighted imaging (7:03), fluid-attenuated inversion recovery imaging (9:31), and diffusion-weighed imaging with apparent diffusion coefficient mapping (9:04). Patients’ demographic information, hours from the time of patients' last known normal (LKN) to time of scan, and discharge diagnoses (determined from final imaging interpretation) were assessed.

Results: pMRI exams were obtained on 54 patients (28 females, 51.9%; median age 71 years, 20-98 years). Discharge diagnoses included ischemic stroke (42.6%) no intracranial abnormality (31.5%), intraparenchymal hemorrhage (7.4%), atherosclerosis (7.4%), tumor (5.6%), subdural hematoma (3.7%), and intraventricular hemorrhage (1.9%). Patient LKN times ranged from 2 to 144 hours (median of 12 hours; 3 patients with no LKN excluded). The pMRI did not interfere with ED equipment and no significant adverse events occurred.

Conclusion: We report the use of a pMRI for bedside neuroimaging in the ED. This approach suggests that pMRI may be viable for supporting rapid diagnosis and treatment candidate selection in patients presenting with stroke symptoms to the ED.

Medroxyprogesterone acetate inhibits wound closure of human endometrial epithelial cells and stromal fibroblasts in vitro

Mucosal integrity in the endometrium is essential for immune protection. Since breaches or injury to the epithelial barrier exposes underlying tissue and is hypothesized to increase infection risk, we determined whether endogenous progesterone or three exogenous progestins (medroxyprogesterone acetate (MPA), norethindrone (NET), and levonorgestrel (LNG)) used by women as contraceptives interfere with wound closure of endometrial epithelial cells and fibroblasts in vitro. Progesterone and LNG had no inhibitory effect on wound closure by either epithelial cells or fibroblasts. MPA significantly impaired wound closure in both cell types and delayed the reestablishment of transepithelial resistance by epithelial cells. In contrast to MPA, NET selectively decreased wound closure by stromal fibroblasts but not epithelial cells. Following epithelial injury, MPA but not LNG or NET, blocked the injury-induced upregulation of HBD2, a broad-spectrum antimicrobial implicated in wound healing, but had no effect on the secretion of RANTES, CCL20 and SDF-1α. This study demonstrates that, unlike progesterone and LNG, MPA and NET may interfere with wound closure following injury in the endometrium, potentially conferring a higher risk of pathogen transmission. Our findings highlight the importance of evaluating progestins for their impact on wound repair at mucosal surfaces.

Sex Hormones and Aging Modulate Interferon Lambda 1 Production and Signaling by Human Uterine Epithelial Cells and Fibroblasts

Estradiol (E2) and progesterone (P) have potent effects on immune function in the human uterine endometrium which is essential for creating an environment conducive for successful reproduction. Type III/lambda (λ) interferons (IFN) are implicated in immune defense of the placenta against viral pathogens, which occurs against the backdrop of high E2 and P levels. However, the effect of E2 and P in modulating the expression and function of IFNλ1 in the non-pregnant human uterine endometrium is unknown. We generated purified in vitro cultures of human uterine epithelial cells and stromal fibroblast cells recovered from hysterectomy specimens. Poly (I:C), a viral dsRNA mimic, potently increased secretion of IFNλ1 by both epithelial cells and fibroblasts. The secretion of IFNλ1 by epithelial cells significantly increased with increasing age following poly (I:C) stimulation. Stimulation of either cell type with E2 (5x10-8M) or P (1x10-7M) had no effect on expression or secretion of IFNλ1 either alone or in the presence of poly (I:C). E2 suppressed the IFNλ1-induced upregulation of the antiviral IFN-stimulated genes (ISGs) MxA, OAS2 and ISG15 in epithelial cells, but not fibroblasts. Estrogen receptor alpha (ERα) blockade using Raloxifene indicated that E2 mediated its inhibitory effects on ISG expression via ERα. In contrast to E2, P potentiated the upregulation of ISG15 in response to IFNλ1 but had no effect on MxA and OAS2 in epithelial cells. Our results demonstrate that the effects of E2 and P on IFNλ1-induced ISGs are cell-type specific. E2-mediated suppression, and selective P-mediated stimulation, of IFNλ1-induced ISG expression in uterine epithelial cells suggest that the effects of IFNλ1 varies with menstrual cycle stage, pregnancy, and menopausal status. The suppressive effect of E2 could be a potential mechanism by which ascending pathogens from the lower reproductive tract can infect the pregnant and non-pregnant endometrium.

Sepsis Fluid Metric Compliance and its Impact on Outcomes of Patients with Congestive Heart Failure, End-Stage Renal Disease or Obesity

BACKGROUND

Emergency physicians express concern administering a 30-cc/kg fluid bolus to septic shock patients with pre-existing congestive heart failure (CHF), end-stage renal disease (ESRD), or obesity, due to the perceived risk of precipitating a fluid overload state.

OBJECTIVE

Our aim was to determine whether there is a difference in fluid administration to septic shock patients with these pre-existing conditions in the emergency department (ED). Secondary objectives focused on whether compliance impacts mortality, need for intubation, and length of stay.

METHODS

We conducted a retrospective chart review of 470,558 ED patient encounters at a single urban academic center during a 5-year period.

RESULTS

Of 847 patients with septic shock, 308 (36.36%) had no pre-existing condition and 199 (23.49%), 17 (2.01%), and 154 (18.18%) had the single pre-existing condition of CHF, ESRD, and obesity, respectively, and 169 (19.95%) had multiple pre-existing conditions. Weight-based fluid compliance was achieved in 460 patients (54.31%). There was a lower likelihood of compliance among patients with CHF (adjusted odds ratio [aOR] 0.35; 95% confidence interval [CI] 0.24-0.52; p < 0.001), ESRD (aOR 0.11, 95% CI 0.04-0.32; p < 0.001), and obesity (aOR 0.29, 95% CI 0.19-0.44; p < 0.001) compared with patients with no pre-existing conditions. Compliance decreased further in patients with multiple pre-existing conditions (aOR 0.49, 95% CI 0.33-0.72; p < 0.001). Compliance was not associated with mortality in patients with CHF and ESRD, but was protective in patients with obesity and those with no pre-existing conditions.

CONCLUSIONS

Septic shock patients with pre-existing CHF, ESRD, or obesity are less likely to achieve compliance with a 30-cc/kg weight-based fluid goal compared with those without these pre-existing conditions.

The impact of aging on innate and adaptive immunity in the human female genital tract

Mucosal tissues in the human female reproductive tract (FRT) are primary sites for both gynecological cancers and infections by a spectrum of sexually transmitted pathogens, including human immunodeficiency virus (HIV), that compromise women's health. While the regulation of innate and adaptive immune protection in the FRT by hormonal cyclic changes across the menstrual cycle and pregnancy are being intensely studied, little to nothing is known about the alterations in mucosal immune protection that occur throughout the FRT as women age following menopause. The immune system in the FRT has two key functions: defense against pathogens and reproduction. After menopause, natural reproductive function ends, and therefore, two overlapping processes contribute to alterations in immune protection in aging women: menopause and immunosenescence. The goal of this review is to summarize the multiple immune changes that occur in the FRT with aging, including the impact on the function of epithelial cells, immune cells, and stromal fibroblasts. These studies indicate that major aspects of innate and adaptive immunity in the FRT are compromised in a site‐specific manner in the FRT as women age. Further, at some FRT sites, immunological compensation occurs. Overall, alterations in mucosal immune protection contribute to the increased risk of sexually transmitted infections (STI), urogenital infections, and gynecological cancers. Further studies are essential to provide a foundation for the development of novel therapeutic interventions to restore immune protection and reverse conditions that threaten women's lives as they age.

Endometrial Cancer Suppresses CD8+ T Cell-Mediated Cytotoxicity in Postmenopausal Women

Endometrial cancer is the most common gynecological cancer. To investigate how it suppresses host immune function, we isolated CD8+ T cells from endometrial endometroid carcinomas and adjacent non-cancerous endometrium and determined if the tumor environment regulates cytotoxic capacity. Endometrial carcinomas had increased numbers of CD8+ T cells compared to adjacent non-cancerous endometrium. Tumor CD8+ T cells expressed significantly less granzyme A (GZA), B (GZB), and PD-1 than those in adjacent non-cancerous tissues and also had significantly lower cytotoxic killing of allogeneic target cells. CD103-CD8+ T cells, but not CD103+CD8+ T cells, from both adjacent and tumor tissue were primarily responsible for killing of allogeneic target cells. Secretions recovered from endometrial carcinoma tissues suppressed CD8+ cytotoxic killing and lowered perforin, GZB and PD-1 expression relative to non-tumor CD8+ T cells. Furthermore, tumor secretions contained significantly higher levels of immunosuppressive cytokines including TGFβ than non-tumor tissues. Thus, the tumor microenvironment suppresses cytotoxic killing by CD8+ T cells via the secretion of immunosuppressive cytokines leading to decreased expression of intracellular cytolytic molecules. These studies demonstrate the complexity of CD8+ T cell regulation within the endometrial tumor microenvironment and provide a foundation of information essential for the development of therapeutic strategies for gynecological cancers.

Drip-and-ship versus mothership for endovascular treatment of acute stroke: A comparative effectiveness analysis

BACKGROUND

Triage for suspected acute stroke has two main options: (1) transport to the closest primary stroke center (PSC) and then to the nearest comprehensive stroke center (CSC) (Drip-and-Ship) or (2) transport the patient to the nearest CSC, bypassing a closer PSC (mothership). The purpose was to evaluate the effectiveness of drip-and-ship versus mothership models for acute stroke patients.

METHODS

A Markov decision-analytic model was constructed. All model parameters were derived from recent medical literature. Our target population was adult patient with sudden onset of acute stroke within 8 h of onset over a one-year horizon. The primary outcome was quantified in terms of quality-adjusted-life-years (QALYs).

RESULTS

The base case scenario show that the drip-and-ship strategy has a slightly higher expected health benefit, 0.591 QALY, as compared to 0.586 QALY in the mothership strategy when the time to PSC is 30 min and to CSC is 65 min, although the difference in health benefit becomes minimal as the time to PSC increases towards 60 min. Multiple sensitivity analyses show that when both PSC and CSC are far from place of onset (>1.5 h away), drip-and-ship becomes the better strategy. Mothership strategy is favored by smaller difference between distances to PSC and CSC, shorter transfer time from PSC to CSC, and longer delay in reperfusion in CSC for transferred patients. Drip-and-ship is favored by the reverse.

CONCLUSION

Drip-and-ship has a slightly higher utility than mothership. This study assesses the complex issue of prehospital triage of acute stroke patients and can provide a framework for real-world data input.

Care of the Patient With Acute Ischemic Stroke (Prehospital and Acute Phase of Care): Update to the 2009 Comprehensive Nursing Care Scientific Statement: A Scientific Statement From the American Heart Association

The year 2020 was the year of the nurse, celebrating nurse scholarship, innovation, and leadership by promoting scientific nursing research, improving nursing practice, advancing nursing education, and providing leadership to influence health policy. As architects of stroke care, neuroscience nurses play a vital role in collaborating and coordinating care between multiple health professionals. Nurses improve accessibility and equity through telestroke, emergency medical services, and mobile stroke units and are integral to implementing education strategies by advocating and ensuring that patients and caregivers receive stroke education while safely transitioning through the health care system and to home. Stroke care is increasingly complex in the new reperfusion era, requiring nurses to participate in continuing education while attaining levels of competency in both the acute and recovery care process. Advanced practice nurses are taking the lead in many organizations, serving as prehospital providers on mobile stroke units, participating as members of the stroke response team, and directing stroke care protocols in the emergency department. This scientific statement is an update to the 2009 "Comprehensive Overview of Nursing and Interdisciplinary Care of the Acute Ischemic Stroke Patient." The aim is to provide a comprehensive review of the scientific evidence on nursing care in the prehospital and hyperacute emergency hospital setting, arming nurses with the necessary tools to provide evidenced-based high-quality care.

Abstract MP36: Blood Pressure Reductions in the Hyperacute Phase of Large Vessel Occlusion Ischemic Stroke Are Associated With Infarct Progression and Poor Functional Outcome

Introduction: Decreases in blood pressure (BP) during endovascular therapy (EVT) have been associated with infarct progression and worse outcome after large vessel occlusion (LVO) stroke. However, BP trajectories in the hyperacute phase prior to EVT have not been well characterized. We used high-frequency BP and hemodynamic monitoring to study the timing of BP reductions during the hyperacute period of stroke and evaluated their relation to infarct progression and functional outcome.

Methods: We prospectively enrolled patients with anterior circulation LVO stroke undergoing EVT. BP and cardiac hemodynamic variables were recorded every 20 seconds from ER admission until the end of EVT using non-invasive finger plethysmography. Patients underwent initial CT perfusion imaging and a follow-up MRI at 24 hours to calculate infarct growth. The following hemodynamic parameters were defined as exposure variables: the difference between admission MAP and lowest MAP (ΔMAP), MAP drop> 20% from admission, MAP<70 mmHg, and SBP<140 mmHg. Functional outcome was measured with the modified Rankin Scale (mRS) at 90 days. Core associations between BP reductions and outcomes were studied using linear regression and logistic regression models.

Results: 45 patients underwent continuous BP monitoring (age 72±17; 58% female; NIHSS 13±6). Aggregated time series data revealed a marked BP reduction around the time of imaging from which patients recovered (mean SBP 33 mmHg, duration 18 min). A sustained decrease in BP was observed after groin puncture without return to baseline BP levels. A linear regression analysis revealed a 13ml infarct growth for every 10 mmHg reduction in ΔMAP (p=0.054). Patients were divided into two groups based on median ΔMAP = 29. Those with ΔMAP ≤29 had better functional outcome at 90 days (34.78% vs. 9.09%, p = 0.038).

Conclusion: Marked and frequently iatrogenic BP reductions occur around the time of initial imaging and may present a potential target for therapeutic intervention. Decrease in blood pressure before reperfusion may increase the risk of infarct progression and poor functional outcome. Changes in cardiac hemodynamic variables throughout the acute stroke period suggest a potential role for fluid resuscitation for hemodynamic optimization.

Abstract 33: Qualitative Description of Ischemic Stroke Appearance on Low-Field, Point-Of-Care Magnetic Resonance Imaging

Background and Aims: Advances in low-field MRI have enabled image acquisition at the point-of-care (POC). We aim to characterize ischemic lesions in low-field, POC MRI and assess its relationship with stroke severity in ischemic stroke patients.

Methods: We performed POC MRI exams on ischemic stroke patients. T2-weighted (T2W), fluid-attenuated inversion recovery (FLAIR), and diffusion-weighted imaging (DWI) exams were acquired with a 64mT, portable bedside MRI system. Three raters computed signal intensity ratios (SIR) for each sequence. For every slice showing an infarct, an SIR was generated by dividing the mean signal intensity of the lesion by the mean signal intensity of the contralateral hemisphere. Infarct volumes were obtained by multiplying the lesion area of each slice by the slice thickness (5mm) and summing the cross-sectional areas. Volumes were correlated with National Institutes of Health Stroke Scale (NIHSS) scores at the time of scan.

Results: We studied 18 ischemic stroke patients (50% women; ages 30-95 years). Two patients were studied at two and three serial timepoints, respectively. POC exams were obtained 2.7 ± 2.2 days after symptom onset. A total of 18 T2W, 17 FLAIR, and 18 DWI exams were obtained. Three exams (1 T2W; 1 FLAIR; 1 DWI) were excluded due to motion degradation. High field MRI exams (19 ± 16 hours from POC exams) demonstrated ischemic infarcts in 15 of the 18 patients. All POC T2W and FLAIR exams revealed infarcts in these patients, and 14 of the 17 DWI exams showed infarcts. Ischemic infarcts were seen as hyperintense lesions (SIR: T2W = 1.19 ± 0.10, FLAIR = 1.15 ± 0.08, DWI = 1.36 ± 0.17). Infarct volume significantly correlated with NIHSS scores (T2W: r = 0.71, p < 0.01; FLAIR: r = 0.65, p < 0.05; DWI: r = 0.65, p < 0.05).

Conclusions: These preliminary data suggest that low-field, POC MRI may be useful in the clinical evaluation of ischemic stroke. Further work in larger cohorts is needed to elucidate the appearance of infarction on low-field imaging.

Direct and Indirect endocrine-mediated suppression of human endometrial CD8+T cell cytotoxicity

Regulation of endometrial (EM) CD8+T cells is essential for successful reproduction and protection against pathogens. Suppression of CD8+T cells is necessary for a tolerogenic environment that promotes implantation and pregnancy. However, the mechanisms regulating this process remain unclear. Sex hormones are known to control immune responses directly on immune cells and indirectly through the tissue environment. When the actions of estradiol (E2), progesterone (P) and TGFβ on EM CD8+T cells were evaluated, cytotoxic activity, perforin and granzymes were directly suppressed by E2 and TGFβ but not P. Moreover, incubation of polarized EM epithelial cells with P, but not E2, increased TGFβ secretion. These findings suggest that E2 acts directly on CD8+T cell to suppress cytotoxic activity while P acts indirectly through induction of TGFβ production. Understanding the mechanisms involved in regulating endometrial CD8+T cells is essential for optimizing reproductive success and developing protective strategies against genital infections and gynecological cancers.

Crisis Resource Management and High-Performing Teams in Hyperacute Stroke Care

BACKGROUND AND PURPOSE

Management of stroke patients in the acute setting is a high-stakes task with several challenges including the need for rapid assessment and treatment, maintenance of high-performing team dynamics, management of cognitive load affecting providers, and factors impacting team communication. Crisis resource management (CRM) provides a framework to tackle these challenges and is well established in other resuscitative disciplines. The current Coronavirus Disease 2019 (COVID-19) pandemic has exposed a potential quality gap in emergency preparedness and the ability to adapt to emergency scenarios in real time.

METHODS

Available resources in the literature in other disciplines and expert consensus were used to identify key elements of CRM as they apply to acute stroke management.

RESULTS

We outline essential ingredients of CRM as a means to mitigate nontechnical challenges providers face during acute stroke care. These strategies include situational awareness, triage and prioritization, mitigation of cognitive load, team member role clarity, communication, and debriefing. Incorporation of CRM along with simulation is an established tool in other resuscitative disciplines and can be incorporated into acute stroke care.

CONCLUSIONS

As stroke care processes evolve during these trying times, the importance of consistent, safe, and efficacious care facilitated by CRM principles offers a unique avenue to alleviate human factors and support high-performing teams.

Stroke Code Presentations, Interventions, and Outcomes Before and During the COVID-19 Pandemic

Supplemental Digital Content is available in the text.

Background:

Anecdotal reports suggest fewer patients with stroke symptoms are presenting to hospitals during the coronavirus disease 2019 (COVID-19) pandemic. We quantify trends in stroke code calls and treatments at 3 Connecticut hospitals during the local emergence of COVID-19 and examine patient characteristics and stroke process measures at a Comprehensive Stroke Center (CSC) before and during the pandemic.

Methods:

Stroke code activity was analyzed from January 1 to April 28, 2020, and corresponding dates in 2019. Piecewise linear regression and spline models identified when stroke codes in 2020 began to decline and when they fell below 2019 levels. Patient-level data were analyzed in February versus March and April 2020 at the CSC to identify differences in patient characteristics during the pandemic.

Results:

A total of 822 stroke codes were activated at 3 hospitals from January 1 to April 28, 2020. The number of stroke codes/wk decreased by 12.8/wk from February 18 to March 16 (P=0.0360) with nadir of 39.6% of expected stroke codes called from March 10 to 16 (30% decrease in total stroke codes during the pandemic weeks in 2020 versus 2019). There was no commensurate increase in within-network telestroke utilization. Compared with before the pandemic (n=167), pandemic-epoch stroke code patients at the CSC (n=211) were more likely to have histories of hypertension, dyslipidemia, coronary artery disease, and substance abuse; no or public health insurance; lower median household income; and to live in the CSC city (P<0.05). There was no difference in age, sex, race/ethnicity, stroke severity, time to presentation, door-to-needle/door-to-reperfusion times, or discharge modified Rankin Scale.

Conclusions:

Hospital presentation for stroke-like symptoms decreased during the COVID-19 pandemic, without differences in stroke severity or early outcomes. Individuals living outside of the CSC city were less likely to present for stroke codes at the CSC during the pandemic. Public health initiatives to increase awareness of presenting for non-COVID-19 medical emergencies such as stroke during the pandemic are critical.

Pandemic Guidance for Stroke Centers Aiding COVID-19 Treatment Teams

The coronavirus disease 2019 (COVID-19) pandemic has in some regions overwhelmed the capacity and staffing needs of healthcare systems, necessitating the provision of resources and staff from different disciplines to aid COVID treatment teams. Stroke centers have multidisciplinary clinical and procedural expertise to support COVID treatment teams. Staff safety and patient safety are essential, as are open lines of communication between stroke center leaders and hospital leadership in a pandemic where policies and procedures can change or evolve rapidly. Support needs to be allocated in a way that allows for the continued operation of a fully capable stroke center, with the ability to adjust if stroke center volume or staff attrition requires.

Differential Cytotoxic Function of Resident and Non-resident CD8+ T Cells in the Human Female Reproductive Tract Before and After Menopause

The functional characterization and regulation of tissue resident and non-resident CD8+ T cells in the human female reproductive tract (FRT) as women age remains a gap in our knowledge. Here we characterized the cytotoxic activity and granular contents of CD8+ T cells from the FRT in pre- and postmenopausal women. We found that under steady-state conditions, CD8+ T cells from endometrium (EM), endocervix and ectocervix displayed direct cytotoxic activity, and that cytotoxicity increased in the EM after menopause. Cytotoxic activity was sensitive to suppression by TGFβ exclusively in the EM, and sensitivity to TGFβ was reduced after menopause. Under steady-state conditions, cytotoxic activity (measured as direct killing activity), cytotoxic potential (measured as content of cytotoxic molecules) and proliferation are enhanced in non-resident CD8+ (CD103−) T cells compared to tissue resident (CD103+) T cells. Upon activation, CD103+ T cells displayed greater degranulation compared to CD103− T cells, however the granular content of perforin, granzyme A (GZA) or granzyme B (GZB) was significantly lower. After menopause, degranulation significantly increased, and granular release switched from predominantly GZB in premenopausal to GZA in postmenopausal women. Postmenopausal changes affected both CD103+ and CD103− subpopulations. Finally, CD103+ T cells displayed reduced proliferation compared to CD103− T cells, but after proliferation, cytotoxic molecules were similar in each population. Our results highlight the complexity of regulation of cytotoxic function in the FRT before and after menopause, and are relevant to the development of protective strategies against genital infections and gynecological cancers as women age.

Stroke Center Certification and Performance: A Longitudinal Analysis of the Northeast Cerebrovascular Consortium Region

Background: The NorthEast Cerebrovascular Consortium (NECC) was established in 2006 to improve stroke-systems-of-care models. Methods: This study evaluates the increase in stroke quality over time in NECC and Non-NECC regions, defined as the change in proportion of hospitals over time who received State or National Primary/Comprehensive Stroke Center (PSC/CSC) certification, participated in a national quality program (Get-With-The-Guidelines-Stroke (GWTG-S)), or received GWTG-S Performance Achievement Awards (PAA) from 2005-2013. Analysis of trends was performed (Cochran-Armitage/Cochran-Mantel-Haenszel tests; Generalized-Estimating Equations). As an exploratory analysis eight NECC region Departments of Health (DOH) were surveyed regarding perceptions of the NECC. Results: During the study period, there were 433.1 ± 10.2 vs 3986.4 ± 187.7 hospitals per year in the NECC vs non-NECC regions. Rate of growth per year increased in both groups for each measure but to a greater degree in the NECC vs Non-NECC regions: PSC/CSC (5.4%/yr vs 3.2%/yr), GWTG-S participation (5.0%/yr vs 2.9%/yr), and PAAs (5.2%/yr vs 2.1%/yr), with state-based certification growth also being higher in the NECC region (4.2%/yr vs 0.4%/yr; all comparisons p < 0.0001). After adjusting for year, significantly more NECC hospitals had PSC/CSC certification, GWTG-S participation, and GWTG-S PAAs than non-NECC sites (all analyses p < 0.0001). One hundred percent of NECC region DOHs were aware of the NECC and involved in functions, 87.5% indicated the NECC provided beneficial assistance. Conclusions: There has been a higher rate of growth of state certification contrasted to national PSC/CSC certification, and a higher rate of growth of participation and achievement in GWTG-S in the northeast region compared to other US regions.

IL-27 Expression and Responsiveness in Human Uterine Epithelial Cells and Fibroblasts In Vitro and the Role of Estradiol

Interleukin (IL)-27 is a pleiotropic cytokine that regulates multiple aspects of innate and adaptive immunity, but whose role in immune protection of the female reproductive tract is unknown. Although not constitutively expressed by human uterine epithelial cells and fibroblasts in culture, IL-27 secretion was upregulated after treatment with the viral ligand poly (I:C) in a type I interferon (IFN)-dependent manner, with higher levels measured in fibroblasts than epithelial cells. Estradiol increased poly (I:C)-induced IL-27 production by fibroblasts, but not epithelial cells. While both cell types expressed the IL-27 receptor, only fibroblasts responded to recombinant IL-27 with increased expression of the antiviral genes, APOBEC3G (apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G) and MxA, and the tryptophan-catabolizing enzyme, indoleamine 2,3-dioxygenase (IDO). Estradiol inhibited IL-27-mediated induction of IDO in fibroblasts through estrogen receptor alpha, but had no effect on APOBEC3G. IL-27 pretreatment also potentiated poly (I:C) upregulation of the antiviral genes, OAS2 and APOBEC3G, in fibroblasts. Thus, IL-27 is part of the antiviral response by uterine cells against potential pathogens. The effect of estradiol on IL-27 production and sensitivity by fibroblasts demonstrates a selective hormone action on individual cell types in the uterus and suggests that IL-27 may have differential effects during the menstrual cycle.

Is There a Neurologist in the House? A Summary of the Current State of Neurovascular Rotations for Emergency Medicine Residents

OBJECTIVES

Neurovascular and neurocritical care emergencies constitute a leading cause of morbidity/mortality. There has been great evolution in this field, including but not limited to extended time-window therapeutic interventions for acute ischemic stroke. The intent of this article is to evaluate the goals and future direction of clinical rotations in neurovascular and neurocritical care for emergency medicine (EM) residents.

METHODS

A panel of 13 board-certified emergency physicians from the Society for Academic Emergency Medicine (SAEM) neurologic emergencies interest group (IG) convened in response to a call for publications-three with fellowship training/board certification in stroke and/or neurocritical care; five with advanced research degrees; three who have been authors on national practice guidelines; and six who have held clinical duties within neurology, neurosurgery, or neurocritical care. A mixed-methods analysis was performed including a review of the literature, a survey of Council of Emergency Medicine Residency Directors (CORD) residency leaders/faculty and SAEM neuro-IG members, and a consensus review by this panel of select neurology rotations provided by IG faculty.

RESULTS

Thirteen articles for residency neurovascular education were identified: three studies on curriculum, three studies evaluating knowledge, and seven studies evaluating knowledge after an educational intervention. Intervention outcomes included the ability to recognize and manage acute strokes, manage intracerebral hemorrhage, calculate National Institutes of Health Stroke Scale (NIHSS), and interpret images. In the survey sent to CORD residency leaders and neuro-IG faculty, response was obtained from 48 programs. A total of 52.1% indicated having a required rotation (6.2% general neurology, 2% stroke service, 18.8% neurologic intensive care unit, 2% neurosurgery, 22.9% on a combination of services). The majority of programs with required rotations have a combination rotation (residents rotate through multiple services) and evaluations were positive.

CONCLUSIONS

Variability exists in the availability of neurovascular/neurocritical care rotations for EM trainees. Dedicated clinical time in neurologic education was beneficial to participants. Given recent advancements in the field, augmentation of EM residency training in this area merits strong consideration.

Estradiol-regulated innate antiviral responses of human endometrial stromal fibroblasts

PROBLEM

The contribution of fibroblasts to innate immune protection of the human female reproductive tract (FRT) against viral pathogens is relatively unknown.

METHOD OF STUDY

Endometrial (EM), endocervical (Cx) and ectocervical (ECx) fibroblasts were isolated from hysterectomy patients and grown in vitro. Fibroblasts were treated with the viral mimic poly (I:C) in the presence or absence of the sex hormone estradiol (E₂ ), with gene expression measured by real-time RT-PCR and protein secretion by ELISA.

RESULTS

Poly (I:C) induced the expression of the interferon-stimulated genes (ISG) MxA, OAS2 and APOBEC3G, and the cytokines MCP-1, IL-8, IL-6, CCL20, IFNβ and RANTES by fibroblasts from all three sites. ISG upregulation was dependent upon Type I IFN signaling. E₂ inhibited the poly (I:C)-induced upregulation of MxA and OAS2 in EM fibroblasts, but not Cx or ECx fibroblasts. E₂ upregulated SDF-1α by EM fibroblasts but had no effect on secretion of other cytokines either alone or in the presence of poly (I:C). Conditioned media (CM) from poly (I:C)-treated or E₂ -treated fibroblasts significantly reduced HIV infection of CD4+ T cells.

CONCLUSION

Stromal fibroblasts represent a level of innate immune protection against viral pathogens in the FRT beyond that seen with epithelial cells and immune cells. Our findings indicate that fibroblasts FRT are selectively responsive to E₂ , capable of initiating an antiviral response against viral pathogens and may play a role in preventing HIV infection of CD4+ T cells.

Neutrophil extracellular traps prevent HIV infection in the female genital tract

Women acquire human immunodeficiency virus (HIV) mainly through sexual intercourse. However, low transmission rates per sexual act indicate that local immune mechanisms contribute to HIV prevention. Neutrophils represent 10-20% of the genital immune cells in healthy women. Neutrophils mediate mucosal protection against bacterial and fungal pathogens through different mechanisms, including the release of neutrophil extracellular traps (NETs). NETs are DNA fragments associated with antimicrobial granular proteins. Despite neutrophil abundance and central contributions to innate immunity in the genital tract, their role in protection against HIV acquisition is unknown. We found that stimulation of human genital neutrophils with HIV viral-like particles (HIV-VLPs) induced NET release within minutes of viral exposure, through reactive oxygen species-independent mechanisms that resulted in immediate entrapment of HIV-VLPs. Incubation of infectious HIV with pre-formed genital NETs prevented infection of susceptible cells through irreversible viral inactivation. HIV inactivation by NETs from genital neutrophils could represent a previously unrecognized form of mucosal protection against HIV acquisition.

Poly (I:C) and LPS induce distinct immune responses by ovarian stromal fibroblasts

Despite its anatomical location, the ovary is a site of pathogen exposure in the human female reproductive tract (FRT). However, the role of ovarian stromal fibroblasts in immune protection is unclear. We generated a population of ovarian stromal fibroblasts derived from normal human ovaries that expressed the pattern recognition receptors TLR3, TLR4, RIG-I, & MDA5. Poly (I:C) and LPS, respective mimics of viral and bacterial infections, selectively upregulated antiviral gene expression and secretion of chemokines and antimicrobials. Poly (I:C) exclusively stimulated the expression of interferon (IFN) β, IFNλ1, and the IFN-stimulated gene OAS2. Poly (I:C) also significantly increased secretion of elafin, CCL20, and RANTES, but had no effect on SDF-1α. In contrast, LPS had no effect on IFN or ISG expression but significantly increased secretion of RANTES and SDF-1α. Secretions from poly (I:C)-treated fibroblasts had both greater anti-HIV activity and induced higher levels of CD4 + T cell chemotaxis than those from LPS-treated cells. Our studies demonstrate a potential key role for ovarian fibroblasts in innate immune protection against incoming pathogens in the normal ovary.

Aging impacts CD103+ CD8+ T cell presence and induction by dendritic cells in the genital tract

As women age, susceptibility to systemic and genital infections increases. Tissue-resident memory T cells (TRMs) are CD103⁺ CD8⁺ long-lived lymphocytes that provide critical mucosal immune protection. Mucosal dendritic cells (DCs) are known to induce CD103 expression on CD8⁺ T cells. While CD103⁺ CD8⁺ T cells are found throughout the female reproductive tract (FRT), the extent to which aging impacts their presence and induction by DCs remains unknown. Using hysterectomy tissues, we found that endometrial CD103⁺ CD8⁺ T cells were increased in postmenopausal compared to premenopausal women. Endometrial DCs from postmenopausal women were significantly more effective at inducing CD103 expression on allogeneic naïve CD8⁺ T cells than DCs from premenopausal women; CD103 upregulation was mediated through membrane-bound TGFβ signaling. In contrast, cervical CD103⁺ T cells and DC numbers declined in postmenopausal women with age. Decreases in DCs correlated with decreased CD103⁺ T cells in endocervix, but not ectocervix. Our findings demonstrate a previously unrecognized compartmentalization of TRMs in the FRT of postmenopausal women, with loss of TRMs and DCs in the cervix with aging, and increased TRMs and DC induction capacity in the endometrium. These findings are relevant to understanding immune protection in the FRT and to the design of vaccines for women of all ages.

Isolation of Dendritic Cells from the Human Female Reproductive Tract for Phenotypical and Functional Studies

The characterization of the human dendritic cells (DCs) resident in mucosal tissues is challenging due to the difficulty in obtaining samples, and the low numbers of DCs present per tissue. Yet, as the phenotype and function of DCs is modified by the tissue environment, it is necessary to analyze tissue resident DC populations, since blood derived DCs incompletely reflect the complexities of DCs in tissues. Here we present a protocol to isolate DCs from the human female reproductive tract (FRT) using hysterectomy specimens that allows both phenotypical and functional analyses. The protocol consists of tissue digestion to generate a single cell mixed cell suspension, followed by positive magnetic bead selection. Our tissue digestion protocol does not cleave surface markers, which allows phenotypical and functional analysis of DCs in the steady state, without overnight incubation or cell activation. This protocol can be adapted for the isolation of other immune cell types or isolation of DCs from other tissues.

Evaluation of a novel 5-group classification system of sepsis by vasopressor use and initial serum lactate in the emergency department

Prognostication in sepsis is limited by disease heterogeneity, and measures to risk-stratify patients in the proximal phases of care lack simplicity and accuracy. Hyperlactatemia and vasopressor dependence are easily identifiable risk factors for poor outcomes. This study compares incidence and hospital outcomes in sepsis based on initial serum lactate level and vasopressor use in the emergency department (ED). In a retrospective analysis of a prospectively identified dual-center ED registry, patients with sepsis were categorized by ED vasopressor use and initial serum lactate level. Vasopressor-dependent patients were categorized as dysoxic shock (lactate >4.0 mmol/L) and vasoplegic shock (≤4.0 mmol/L). Patients not requiring vasopressors were categorized as cryptic shock major (lactate >4.0 mmol/L), cryptic shock minor (>2.0 and ≤4.0 mmol/L), and sepsis without lactate elevation (≤2.0 mmol/L). Of 446 patients included, 4.9% (n = 22) presented in dysoxic shock, 11.7% (n = 52) in vasoplegic shock, 12.1% (n = 54) in cryptic shock major, 30.9% (n = 138) in cryptic shock minor, and 40.4% (n = 180) in sepsis without lactate elevation. Group mortality rates at 28 days were 50.0, 21.1, 18.5, 12.3, and 7.2%, respectively. After adjusting for potential confounders, odds ratios for mortality at 28 days were 15.1 for dysoxic shock, 3.6 for vasoplegic shock, 3.8 for cryptic shock major, and 1.9 for cryptic shock minor, when compared to sepsis without lactate elevation. Lactate elevation is associated with increased mortality in both vasopressor dependent and normotensive infected patients presenting to the emergency department (ED). Cryptic shock mortality (normotension + lactate >4 mmol/L) is equivalent to vasoplegic shock mortality (vasopressor requirement + lactate <4 mmol/L) in our population. The odds of normotensive, infected patients decompensating is three to fourfold higher with hyperlactemia. The proposed Sepsis-3 definitions exclude an entire group of high-risk ED patients. A simple classification in the ED by vasopressor requirement and initial lactate level may identify high-risk subgroups of sepsis. This study may inform prognostication and triage decisions in the proximal phases of care.

Hormonal Contraceptives Differentially Suppress TFV and TAF Inhibition of HIV Infection and TFV-DP in Blood and Genital Tract CD4+ T cells

HIV prevention research is focused on combining antiretrovirals (ARV) and progestin contraceptives to prevent HIV infection and pregnancy. The possibility that progestins compromise ARV anti-HIV activity prompted us to evaluate the effects of progestins on tenofovir (TFV) and TFV-alafenamide (TAF) on HIV infection and intracellular TFV-diphosphate (TFV-DP) concentrations in blood and genital CD4+ T cells. Following incubation of blood CD4+ T cells with TFV or TAF, Medroxyprogesterone acetate (MPA), but not Levonorgestrel, Norethisterone or progesterone, suppressed the anti-HIV effect of TFV by reducing intracellular TFV-DP, but had no effect on TAF inhibition of infection or TFV-DP. In contrast, with genital CD4+ T cells, MPA suppressed TAF inhibition of HIV infection and lowered of TFV-DP concentrations without affecting TFV protection. These findings demonstrate that MPA selectively compromises TFV and TAF protection in blood and genital CD4+ T cells and suggests that MPA may decrease ARV protection in individuals who use ARV intermittently for prevention.

Volume of Plasma Expansion and Functional Outcomes in Stroke

BACKGROUND

Plasma expansion in acute ischemic stroke has potential to improve cerebral perfusion, but the long-term effects on functional outcome are mixed in prior trials. The goal of this study was to evaluate how the magnitude of plasma expansion affects neurological recovery in acute stroke.

METHODS

This was a secondary analysis of data from the Albumin in Acute Stroke Part 2 trial investigating the relationship between the magnitude of overall intravenous volume infusion (crystalloid and colloid) to clinical outcome. The data were inclusive of 841 patients with a mean age of 64 years and a median National Institutes of Health Stroke Scale (NIHSS) of 11. In a multivariable-adjusted logistic regression model, this analysis tested the volume of plasma expansion over the first 48 h of hospitalization as a predictor of favorable outcome, defined as either a modified Rankin Scale score of 0 or 1 or a NIHSS score of 0 or 1 at 90 days. This model included all study patients, irrespective of albumin or isotonic saline treatment.

RESULTS

Patients that received higher volumes of plasma expansion more frequently had large vessel ischemic stroke and higher NIHSS scores. The multivariable-adjusted model revealed that there was decreased odds of a favorable outcome for every 250 ml additional volume plasma expansion over the first 48 h (OR 0.91, 95 % CI, 0.88-0.94).

CONCLUSIONS

The present study demonstrates an association between greater volume of plasma expansion and worse neurological recovery.

Sex as a Biological Variable in Emergency Medicine Research and Clinical Practice: A Brief Narrative Review

The National Institutes of Health recently highlighted the significant role of sex as a biological variable (SABV) in research design, outcome and reproducibility, mandating that this variable be accounted for in all its funded research studies. This move has resulted in a rapidly increasing body of literature on SABV with important implications for changing the clinical practice of emergency medicine (EM). Translation of this new knowledge to the bedside requires an understanding of how sex-based research will ultimately impact patient care. We use three case-based scenarios in acute myocardial infarction, acute ischemic stroke and important considerations in pharmacologic therapy administration to highlight available data on SABV in evidence-based research to provide the EM community with an important foundation for future integration of patient sex in the delivery of emergency care as gaps in research are filled.

Chlamydia trachomatis regulates innate immune barrier integrity and mediates cytokine and antimicrobial responses in human uterine ECC-1 epithelial cells

PROBLEM

Chlamydia trachomatis infection is the most common sexually transmitted bacterial infection worldwide and known to increase the risk for HIV acquisition. Few studies have investigated how infection of epithelial cells compromises barrier integrity and antimicrobial response.

METHOD OF STUDY

ECC-1 cells, a human uterine epithelial cell line, were treated with live and heat-killed C. trachomatis. Epithelial barrier integrity measured as transepithelial resistance (TER), chemokines antimicrobial levels, and antimicrobial mRNA expression was measured by ELISA and Real-time RT-PCR.

RESULTS

Epithelial barrier integrity was compromised when cells were infected with live, but not with heat-killed, C. trachomatis. IL-8 secretion by ECC-1 cells increased in response to live and heat-killed C. trachomatis, while MCP-1, HBD2 and trappin2/elafin secretion decreased with live C. trachomatis.

CONCLUSION

Live C. trachomatis suppresses ECC-1 innate immune responses by compromising the barrier integrity, inhibiting secretion of MCP-1, HBD2, and trappin-2/elafin. Differential responses between live and heat-killed Chlamydia indicate which immune responses are dependent on ECC-1 infection rather than the extracellular presence of Chlamydia.

Characterization of immune cells and infection by HIV in human ovarian tissues

PROBLEM

New HIV infections in women are predominantly spread through sexual intercourse. Recent non-human primate studies demonstrated that simian immunodeficiency virus (SIV) deposited in the vagina infected immune cells in the ovary. Whether immune cells in the human ovary are susceptible to HIV infection is unknown.

METHOD OF STUDY

Immune cells were isolated from ovaries and characterized by flow cytometry. Cells were exposed to HIV for 2 hours. HIV infection was measured by flow cytometry and p24 secretion following 6 days in culture.

RESULTS

CD4⁺ T cells and CD14⁺ cells are present in the ovary and susceptible to infection by HIV-BaL. Among the CD45⁺ cells present, 30% were CD3⁺ T cells (with similar proportions of CD4⁺ or CD8⁺ T cells), and 7%-10% were CD14⁺ cells. Both CD4⁺ T cells and CD14⁺ cells were productively infected and supported replication.

CONCLUSION

Immune cells in the ovary are potential targets for HIV infection.

Dendritic cells from the human female reproductive tract rapidly capture and respond to HIV

Dendritic cells (DCs) throughout the female reproductive tract (FRT) were examined for phenotype, HIV capture ability and innate anti-HIV responses. Two main CD11c⁺ DC subsets were identified: CD11b⁺ and CD11b^low DCs. CD11b⁺CD14⁺ DCs were the most abundant throughout the tract. A majority of CD11c⁺CD14⁺ cells corresponded to CD1c⁺ myeloid DCs, whereas the rest lacked CD1c and CD163 expression (macrophage marker) and may represent monocyte-derived cells. In addition, we identified CD103⁺ DCs, located exclusively in the endometrium, whereas DC-SIGN⁺ DCs were broadly distributed throughout the FRT. Following exposure to GFP-labeled HIV particles, CD14⁺ DC-SIGN⁺ as well as CD14⁺ DC-SIGN^- cells captured virus, with ∼30% of these cells representing CD1c⁺ myeloid DCs. CD103⁺ DCs lacked HIV capture ability. Exposure of FRT DCs to HIV induced secretion of CCL2, CCR5 ligands, interleukin (IL)-8, elafin, and secretory leukocyte peptidase inhibitor (SLPI) within 3 h of exposure, whereas classical pro-inflammatory molecules did not change and interferon-α2 and IL-10 were undetectable. Furthermore, elafin and SLPI upregulation, but not CCL5, were suppressed by estradiol pre-treatment. Our results suggest that specific DC subsets in the FRT have the potential for capture and dissemination of HIV, exert antiviral responses and likely contribute to the recruitment of HIV-target cells through the secretion of innate immune molecules.

Abstract 116: Minorities, Women, and Stroke Belters Left Behind in t-PA Use Despite Quality Improvement Efforts

Introduction: We aimed to describe factors associated with IV tPA use over time, including geography, hospital-related factors, and quality improvement efforts.

Methods: Acute ischemic stroke (AIS) discharges with available hospital identifiers (2005 to 2011) in the National Inpatient Sample (NIS) were identified using ICD9 codes 433.X1, 434.X1, and 436. IV tPA use was determined using procedure code 9910 and code V4588 for drip and ship patients; patient/hospital characteristics were obtained from the NIS. Stroke center designation and Get With The Guidelines (GWTG) performance award data were publicly available. Logistic regression using patient characteristics only was followed by the addition of hospital characteristics, then state characteristics (Table). Adjusted odds ratios (aOR) with 95% CI were reported.

Results: There were 563,087 AIS; median age 74 (IQR 62 – 83), 14.9% Black, and 53.3% female. Overall, 3.76% (n=21,172) received IV tPA. In the fully adjusted model (Table), patients that were Black, Hispanic, or female were less likely to receive IV tPA, while those with private insurance were more likely to receive IV tPA. Each subsequent year, patients were 11% more likely to receive IV tPA (aOR 1.11, 95%CI 1.09-1.13). Patients discharged from designated stroke centers, GWTG hospitals with silver or gold awards, or hospitals that were teaching, large, or urban were more likely to receive IV tPA compared to patients discharged from small, critical access, or rural hospitals. Patients discharged in stroke belt states were less likely to receive IV tPA.

Conclusions: Treatment of AIS with tPA is increasing over time. Discharge from GWTG hospitals with performance achievement awards, stroke centers, or teaching, large, or urban hospitals increased this likelihood. Patients who were black, Hispanic, female, or in the stroke belt were less likely to receive tPA. Further efforts are needed to address these performance gaps.

The impact of pregnancy on anti-HIV activity of cervicovaginal secretions

BACKGROUND

Mucosal immunity of the female genital tract plays a critical role in defense against sexually transmitted infections like HIV. Pregnancy is associated with both structural and immunologic alterations in the genital mucosa, but the impact of these changes on its ability to suppress HIV infection is unknown. Current epidemiologic data are conflicting as to whether pregnancy increases the risk of HIV acquisition.

OBJECTIVE

The purpose of this study was to define the association between antimicrobial peptides and chemokines in cervicovaginal secretions and in vitro HIV infectivity among pregnant and nonpregnant women.

STUDY DESIGN

Forty pregnant and 37 nonpregnant women were enrolled in a prospective longitudinal cohort study at a single tertiary care women's hospital in Providence, RI. Cervicovaginal lavage was performed at each study visit. For pregnant women, study visits occurred once per trimester, and there was an optional postpartum visit. For nonpregnant women, study visits occurred across a single cycle that was timed to occur in the proliferative, ovulatory, and secretory phases based on the presumption of a regular menstrual cycle. The impact of cervicovaginal lavage on HIV infectivity was evaluated using a TZM-bl assay and compared between pregnant and nonpregnant women for each visit. The previously validated TZM-bl assay, which uses a luciferase reporting gene to indicate HIV infection of TZM-bl cells, was measured with a luminometer with higher relative light units that indicate greater levels of in vitro HIV infection. Immune mediators were measured with a multiplex bead assay. HIV infectivity and median concentration of each mediator were compared between pregnant and nonpregnant groups with the Wilcoxon rank sum test.

RESULTS

Cervicovaginal fluid from pregnant and nonpregnant women significantly decreased HIV infectivity in both groups compared with positive control (virus only; P<.01), but infectivity was not different between groups (P≥.44). During the second and third trimesters, pregnant women experienced suppression of several cervicovaginal immune mediators that included human beta defensin-2; lactoferrin; macrophage inflammatory protein-3α; regulated on activation, normally T-cell expressed and secreted; and stromal cell-derived factor-1 (all P≤.05). The antimicrobial peptide elafin was significantly correlated with HIV infectivity in both groups across all visits, except at the postpartum visit in the pregnant group (n=16). Secretory leukocyte protease inhibitor also was correlated significantly with infectivity across all visits, but in nonpregnant women only (P≤.03).

CONCLUSION

Cervicovaginal secretions from both pregnant and nonpregnant women contain immune mediators that are associated with HIV infectivity in an in vitro assay; however, infectivity was not different between pregnant and nonpregnant groups. If pregnant women are at increased risk for HIV infection, it is unlikely to be mediated by alterations in the effectiveness of these protective secretions.

Menopausal status influences the expression of programmed death (PD)-1 and its ligand PD-L1 on immune cells from the human female reproductive tract

PROBLEM

The programmed death 1 (PD-1)/PD-L1 pathway regulates peripheral tolerance, immune responses, and is up-regulated in chronic viral infections, including HIV infection. However, expression of PD-1/PD-L1 on immune cells from the human female reproductive tract (FRT) and possible regulation by menopause and sex hormones are poorly understood.

METHOD OF STUDY

PD-1/PD-L1 expression was analyzed on CD4(+) and CD8(+) T cells, CD163(+) macrophages, and CD11c(+) dendritic cells (DC) from endometrium (EM), endocervix (CX) and ectocervix (ECX). Expression after hormone treatment in culture was also evaluated.

RESULTS

PD-1 and PD-L1 were constitutively expressed on CD4(+) and CD8(+) T cells from the FRT. PD-L1(+) CD4(+) T cells were increased in CX compared to EM and ECX, while no differences were found for PD-1 or between CD8(+) T cells from different sites. Macrophages and DCs constitutively expressed PD-L1, but not PD-1, with no differences observed between FRT sites. Pre-menopausal FRT tissues showed increased PD-L1 expression on CD8(+) T cells, but decreased expression on DCs when compared to post-menopausal women. In vitro estradiol treatment up-regulated PD-L1 expression specifically on CD8(+) T cells from CX, but had no effect on PD-1/PD-L1 expression on the other cell types.

CONCLUSION

Our results suggest that PD-L1 may be involved in the differential regulation of FRT immune responses between pre-menopausal and post-menopausal women.

Missed Ischemic Stroke Diagnosis in the Emergency Department by Emergency Medicine and Neurology Services

BACKGROUND AND PURPOSE

The failure to recognize an ischemic stroke in the emergency department is a missed opportunity for acute interventions and for prompt treatment with secondary prevention therapy. Our study examined the diagnosis of acute ischemic stroke in the emergency department of an academic teaching hospital and a large community hospital.

METHODS

A retrospective chart review was performed from February 2013 to February 2014.

RESULTS

A total of 465 patients with ischemic stroke were included in the analysis; 280 patients from the academic hospital and 185 patients from the community hospital. One hundred three strokes were initially misdiagnosed that is 22% of the included strokes at the combined centers. Fifty-five of these were missed at the academic hospital (22%) [corrected] and 48 were at the community hospital (26%, P=0.11). Thirty-three percent of missed cases presented within a 3-hour time window for recombinant tissue-type plasminogen activator eligibility. An additional 11% presented between 3 and 6 hours of symptom onset for endovascular consideration. Symptoms independently associated with greater odds of a missed stroke diagnosis were nausea/vomiting (odds ratio, 4.02; 95% confidence interval, 1.60-10.1), dizziness (odds ratio, 1.99; 95% confidence interval, 1.03-3.84), and a positive stroke history (odds ratio, 2.40; 95% confidence interval, 1.30-4.42). Thirty-seven percent of posterior strokes were initially misdiagnosed compared with 16% of anterior strokes (P<0.001).

CONCLUSIONS

Atypical symptoms associated with posterior circulation strokes lead to misdiagnoses. This was true at both an academic center and a large community hospital. Future studies need to focus on the evaluation of identification systems and tools in the emergency department to improve the accuracy of stroke diagnosis.