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771 result(s) for "Mullen, Michael T."
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TGF-β1 modulates microglial phenotype and promotes recovery after intracerebral hemorrhage
Intracerebral hemorrhage (ICH) is a devastating form of stroke that results from the rupture of a blood vessel in the brain, leading to a mass of blood within the brain parenchyma. The injury causes a rapid inflammatory reaction that includes activation of the tissue-resident microglia and recruitment of blood-derived macrophages and other leukocytes. In this work, we investigated the specific responses of microglia following ICH with the aim of identifying pathways that may aid in recovery after brain injury. We used longitudinal transcriptional profiling of microglia in a murine model to determine the phenotype of microglia during the acute and resolution phases of ICH in vivo and found increases in TGF-β1 pathway activation during the resolution phase. We then confirmed that TGF-β1 treatment modulated inflammatory profiles of microglia in vitro. Moreover, TGF-β1 treatment following ICH decreased microglial Il6 gene expression in vivo and improved functional outcomes in the murine model. Finally, we observed that patients with early increases in plasma TGF-β1 concentrations had better outcomes 90 days after ICH, confirming the role of TGF-β1 in functional recovery from ICH. Taken together, our data show that TGF-β1 modulates microglia-mediated neuroinflammation after ICH and promotes functional recovery, suggesting that TGF-β1 may be a therapeutic target for acute brain injury.
Case report: Blood-transfusion induced posterior reversible encephalopathy syndrome
Posterior reversible encephalopathy syndrome (PRES) is an increasingly recognized clinical entity associated with a variety of medical conditions. It is commonly considered in the presentation of uncontrolled, severe hypertension. However, more recently, it has been described in the setting of blood transfusion, particularly in those with chronic anemia, even in the absence of severe hypertension. We describe a patient who presented to the emergency department 12 days after large blood transfusion for severe, chronic anemia with headache, vision loss, expressive aphasia and a change in mental status, with only mild blood pressure elevation, who was ultimately diagnosed with PRES and refractory non-convulsive status epilepticus. Emergency physicians are often the first to initiate blood transfusion for those with a low hemoglobin. Therefore, it is prudent to proceed with caution in transfusing those with chronic anemia. It is also important for the emergency physician to keep PRES on the differential for those presenting with a neurologic complaint after correction of their chronic anemia, even in the absence of severe hypertension.
Factors associated with door-in-door-out times in large vessel occlusion stroke patients undergoing endovascular therapy
In the management of large vessel occlusion stroke (LVOS), patients are frequently evaluated first at a non-endovascular stroke center and later transferred to an endovascular stroke center (ESC) for endovascular treatment (EVT). The door-in-door-out time (DIDO) is frequently used as a benchmark for transferring hospitals though there is no universally accepted nor evidenced-based DIDO time. The goal of this study was to identify factors affecting DIDO times in LVOS patients who ultimately underwent EVT. The Optimizing Prehospital Use of Stroke Systems of Care-Reacting to Changing Paradigms (OPUS-REACH) registry is comprised of all LVOS patients who underwent EVT at one of nine endovascular centers in the Northeast United States between 2015 and 2020. We queried the registry for all patients who were transferred from a non-ESC to one of the nine ESCs for EVT. Univariate analysis was performed using t-tests to obtain a p value. A priori, we defined a p value of <0.05 as significant. Multiple logistic regression was conducted to determine the association of variables to estimate an odds ratio. 511 patients were included in the final analysis. The mean DIDO times for all patients was 137.8 min. Vascular imaging and treatment at a non-certified stroke center were associated with longer DIDO times by 23 and 14 min, respectively. On multivariate analyses, the acquisition of vascular imaging was associated with 16 additional minutes spent at the non-ESC while presentation to a non-stroke certified hospital was associated with 20 additional minutes spent at the transferring hospital. The administration of intravenous thrombolysis (IVT) was associated with 15 min less spent at the non-ESC. Vascular imaging and non-stroke certified stroke centers were associated with longer DIDO times. Non-ESCs should integrate vascular imaging into their workflow as feasible to reduce DIDO times. Further work examining other details regarding the transfer process such as transfer via ground or air, could help further identify opportunities to improve DIDO times.
Early Inflammatory Cytokine Expression in Cerebrospinal Fluid of Patients with Spontaneous Intraventricular Hemorrhage
We investigated cerebrospinal fluid (CSF) expression of inflammatory cytokines and their relationship with spontaneous intracerebral and intraventricular hemorrhage (ICH, IVH) and perihematomal edema (PHE) volumes in patients with acute IVH. Twenty-eight adults with IVH requiring external ventricular drainage for obstructive hydrocephalus had cerebrospinal fluid (CSF) collected for up to 10 days and had levels of interleukin-1α (IL-1α), IL-1β, IL-6, IL-8, IL-10, tumor necrosis factor-α (TNFα), and C-C motif chemokine ligand CCL2 measured using enzyme-linked immunosorbent assay. Median [IQR] ICH and IVH volumes at baseline (T0) were 19.8 [5.8–48.8] and 14.3 [5.3–38] mL respectively. Mean levels of IL-1β, IL-6, IL-10, TNF-α, and CCL2 peaked early compared to day 9–10 (p < 0.05) and decreased across subsequent time periods. Levels of IL-1β, IL-6, IL-8, IL-10, and CCL2 had positive correlations with IVH volume at days 3–8 whereas positive correlations with ICH volume occurred earlier at day 1–2. Significant correlations were found with PHE volume for IL-6, IL-10 and CCL2 at day 1–2 and with relative PHE at days 7–8 or 9–10 for IL-1β, IL-6, IL-8, and IL-10. Time trends of CSF cytokines support experimental data suggesting association of cerebral inflammatory responses with ICH/IVH severity. Pro-inflammatory markers are potential targets for injury reduction.
A Shorter Door-In-Door-Out Time Is Associated with Improved Outcome in Large Vessel Occlusion Stroke
Introduction: Endovascular thrombectomy (EVT) significantly improves outcomes in large vessel occlusion stroke (LVOS). When a patient with a LVOS arrives at a hospital that does not perform EVT, emergent transfer to an endovascular stroke center (ESC) is required. Our objective was to determine the association between door-in-door-out time (DIDO) and 90-day outcomes in patients undergoing EVT.Methods: We conducted an analysis of the Optimizing Prehospital Stroke Systems of Care-Reacting to Changing Paradigms (OPUS-REACH) registry of 2,400 LVOS patients treated at nine ESCs in the United States. We examined the association between DIDO times and 90-day outcomes as measured by the modified Rankin scale.Results: A total of 435 patients were included in the final analysis. The mean DIDO time for patients with good outcomes was 17 minute shorter than patients with poor outcomes (122 minutes [min] vs 139 min, P = 0.04). Absolute DIDO cutoff times of ≤60 min, ≤90 min, or ≤120 min were not associated with improved functional outcomes (46.4 vs 32.3%, P = 0.12; 38.6 vs 30.6%, P = 0.10; and 36.4 vs 28.9%, P = 0.10, respectively). This held true for patients with hyperacute strokes of less than four-hour onset. Lower baseline National Institutes of Health Stroke Scale (NIHSS) score (11.9 vs 18.2, P =<.001) and younger age (62.5 vs 74.9 years (P < .001) were associated with improved outcomes. On multiple regression analysis, age (odds ratio [OR] 1.71, 95% confidence interval [CI] 1.45–2.02) and baseline NIHSS score (OR 1.67, 95% CI 1.42–1.98) were associated with improved outcomes while DIDO time was not associated with better outcome (OR 1.13, 95% CI 0.99–1.30).Conclusion:Although the DIDO time was shorter for patients with a good outcome, this was non-significant in multiple regression analysis. Receipt of intravenous thrombolysis and time to EVT were not associated with better outcomes, while male gender, lower age, arrival by private vehicle, and lower NIHSS score portended better outcomes. No absolute DIDO-time cutoff or modifiable factor was associated with improved outcomes for LVOS. This study underscores the need to streamline DIDO times but not to set an artificial DIDO time benchmark to meet.
Blood flow response to orthostatic challenge identifies signatures of the failure of static cerebral autoregulation in patients with cerebrovascular disease
Background The cortical microvascular cerebral blood flow response (CBF) to different changes in head-of-bed (HOB) position has been shown to be altered in acute ischemic stroke (AIS) by diffuse correlation spectroscopy (DCS) technique. However, the relationship between these relative ΔCBF changes and associated systemic blood pressure changes has not been studied, even though blood pressure is a major driver of cerebral blood flow. Methods Transcranial DCS data from four studies measuring bilateral frontal microvascular cerebral blood flow in healthy controls ( n  = 15), patients with asymptomatic severe internal carotid artery stenosis (ICA, n  = 27), and patients with acute ischemic stroke (AIS, n  = 72) were aggregated. DCS-measured CBF was measured in response to a short head-of-bed (HOB) position manipulation protocol (supine/elevated/supine, 5 min at each position). In a sub-group (AIS, n  = 26; ICA, n  = 14; control, n  = 15), mean arterial pressure (MAP) was measured dynamically during the protocol. Results After elevated positioning, DCS CBF returned to baseline supine values in controls ( p  = 0.890) but not in patients with AIS (9.6% [6.0,13.3], mean 95% CI, p  < 0.001) or ICA stenosis (8.6% [3.1,14.0], p  = 0.003)). MAP in AIS patients did not return to baseline values (2.6 mmHg [0.5, 4.7], p  = 0.018), but in ICA stenosis patients and controls did. Instead ipsilesional but not contralesional CBF was correlated with MAP (AIS 6.0%/mmHg [− 2.4,14.3], p  = 0.038; ICA stenosis 11.0%/mmHg [2.4,19.5], p  < 0.001). Conclusions The observed associations between ipsilateral CBF and MAP suggest that short HOB position changes may elicit deficits in cerebral autoregulation in cerebrovascular disorders. Additional research is required to further characterize this phenomenon.
Delay in hospital presentation is the main reason large vessel occlusion stroke patients do not receive intravenous thrombolysis
Intravenous thrombolysis (IVT) and endovascular therapy (EVT) are the mainstays of treatment for large vessel occlusion stroke (LVOS). Prior studies have examined why patients have not received IVT, the most cited reasons being last‐known‐well (LKW) to hospital arrival of >4.5 hours and minor/resolving stroke symptoms. Given that LVOS patients typically present moderate‐to‐severe neurologic deficits, these patients should be easier to identify and treat than patients with minor strokes. This investigation explores why IVT was not administered to a cohort of LVOS patients who underwent EVT. This is an analysis of the Optimizing the Use of Prehospital Stroke Systems of Care (OPUS‐REACH) registry, which contains patients from 9 endovascular centers who underwent EVT between 2015 and 2020. The exposure of interest was the receipt of intravenous thrombolysis. Descriptive summary statistics are presented as means and SDs for continuous variables and as frequencies with percentages for categorical variables. Two‐sample t tests were used to compare continuous variables and the chi‐square test was used to compare categorical variables between those who received IVT and those who did not receive EVT. Two thousand forty‐three patients were included and 60% did not receive IVT. The most common reason for withholding IVT was LKW to arrival of >4.5 (57.2%). The second most common contraindication was oral anticoagulation (15.5%). On multivariable analysis, 2 factors were associated with not receiving IVT: increasing age (odds ratio [OR] 0.86; 95% confidence interval [CI] 0.78–0.93) and increasing time from LKW‐to hospital arrival (OR 0.45 95% CI 0.46–0.49). Like prior studies, the most frequent reason for exclusion from IVT was a LKW to hospital presentation of >4.5 hours; the second reason was anticoagulation. Efforts must be made to increase awareness of the time‐sensitive nature of IVT and evaluate the safety of IVT in patients on oral anticoagulants.
Quality of life after stroke in Pakistan
Background There is very little information about the quality of life (QOL) of stroke survivors in LMIC countries with underdeveloped non communicable health infrastructures, who bear two thirds of the global stroke burden. Methodology We used a sequential mix methods approach. First, a quantitative analytical cross-sectional study was conducted on 700 participants, who constituted 350 stroke survivor and their caregiver dyads. QOL of stroke survivor was assessed via Stroke Specific Quality of Life Scale (SSQOLS) whereas QOL of caregivers was assessed through RAND-36. In addition; we assessed complications, psychosocial and functional disability of stroke survivors. Following this quantitative survey, caregivers were qualitatively interviewed to uncover contextually relevant themes that would evade quantitative surveys. Multiple linear regression technique was applied to report adjusted β-coefficients with 95% C.I. Results The QOL study was conducted from January 2014 till June 2014, in two large private and public centers . At each center, 175 dyads were interviewed to ensure representativeness. Median age of stroke survivors was 59(17) years, 68% were male, 60% reported depression and 70% suffered post-stroke complications. The mean SSQOLS score was 164.18 ± 32.30. In the final model severe functional disability [adjβ -33.77(-52.44, -15.22)], depression [adjβ-23.74(-30.61,-16.82)], hospital admissions [adjβ-5.51(-9.23,-1.92)] and severe neurologic pain [adjβ -12.41(-20.10,-4.77)] negatively impacted QOL of stroke survivors ( P < 0.01 ). For caregivers, mean age was 39.18 ± 13.44 years, 51% were female and 34% reported high stress levels. Complementary qualitative study revealed that primary caregivers were depressed, frustrated, isolated and also disappointed by health services. Conclusion The QOL of Stroke survivors as reported by SSQOLS score was better than compared to those reported from other LMIC settings. However, Qualitative triangulation revealed that younger caregivers felt isolated, depressed, overwhelmed and were providing care at great personal cost. There is a need to develop cost effective holistic home support interventions to improve lives of the survivor dyad as a unit. Trial registration NCT02351778 (Registered as Observational Study).
Combination Therapy of Losartan and Fisetin Reduces Senescence and Enhances Osteogenesis in Human Bone Marrow–Derived Mesenchymal Stem Cells
Bone marrow–derived mesenchymal stem cells (BM‐MSCs) are well established for their osteogenic potential but are prone to senescence with aging or in vitro expansion. Drug treatments that reduce cellular senescence may enhance the regenerative capacity of BM‐MSCs. This study investigates the effects of losartan and fisetin, both separately and in combination, on cellular senescence and osteogenesis. Human BM‐MSCs were exposed to low and high concentrations of each drug for 24 h. Our findings showed that high‐dose losartan exhibited cytotoxicity, focusing subsequent analyses on the low doses. Both low‐dose losartan and fisetin effectively mitigated cellular senescence, with combined treatment showing synergistic effects in reducing senescence markers. From these initial findings, subsequent experiments utilized low doses of both compounds to evaluate their effect on differentiation capacity. Our multimodal approach, incorporating flow cytometry, senescence‐associated heterochromatin foci (SAHF) immunohistochemistry, senescence‐associated secretory phenotype (SASP) quantification, and differentiation potential assays, revealed that the combination of 23.6 μM of losartan and 50 μM of fisetin was optimal for reducing cellular senescence and enhancing osteogenesis in BM‐MSCs. These results support potential therapeutic strategies to counteract age‐related declines in bone health and improve healing. By targeting cellular senescence while promoting osteogenesis, losartan and fisetin offer promising avenues for future research aimed at enhancing the regenerative capacity of BM‐MSCs in the context of musculoskeletal regenerative medicine.
The Effect of Telemedicine on Access to Acute Stroke Care in Texas: The Story of Age Inequalities
Background. Ischemic stroke is a time sensitive disease with the effectiveness of treatment decreasing over time. Treatment is more likely to occur at Primary Stroke Centers (PSC); thus rapid access to acute stroke care through stand-alone PSCs or telemedicine (TM) is vital for all Americans. The objective of this study is to determine if disparities exist in access to PSCs or the extended access to acute stroke care provided by TM. Methods. Data from the US Census Bureau and the 2010 Neilson Claritas Demographic Estimation Program, American Hospital Association annual survey, and The Joint Commission list of PSCs and survey response data for all hospitals in the state of Texas were used. Results. Over 64% of block groups had 60-minute ground access to acute stroke care. The odds of a block group having 60-minute access to acute stroke care decreased with age, despite adjustment for sex, race, ethnicity, socioeconomic status, urbanization, and total population. Conclusion. Our survey of Texas hospitals found that as the median age of a block group increased, the odds of having access to acute stroke care decreased.