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Sickle cell disease (SCD) is a life-limiting multisystem disease primarily affecting individuals of African and Latinx descent. Its most common complication is painful vaso-occlusive episodes (VOEs), which is also the most common reason individuals with SCD seek care in the emergency department (ED). National guidelines recommend the use of standardized approaches to pain management in the ED, preferably using pain management plans tailored to each patient. However, no standard approach to developing these plans exists. This article describes the development of an opioid calculator to help SCD clinicians create individualized plans to better manage acute painful VOE in the ED setting., (Copyright © 2024 The Joint Commission. Published by Elsevier Inc. All rights reserved.)

Abstract: Fifty years ago, people with sickle cell disease (SCD) were discouraged from becoming pregnant, but now, most should be supported if they choose to pursue a pregnancy. They and their providers, however, should be aware of the physiological changes of pregnancy that aggravate SCD and pregnancy's unique maternal and fetal challenges. Maternal problems can arise from chronic underlying organ dysfunction such as renal disease or pulmonary hypertension; from acute complications of SCD such as acute anemia, vaso-occlusive crises, and acute chest syndrome; and/or from pregnancy-related complications such as preeclampsia, sepsis, severe anemia, thromboembolism, and the need for cesarean delivery. Fetal problems include alloimmunization, opioid exposure, fetal growth restriction, preterm delivery, and stillbirth. Before and during pregnancy, in addition to the assessment and care that every pregnant patient should receive, patients with SCD should be evaluated and treated by a multidisciplinary team with respect to their unique maternal and fetal issues., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Abstract: Cell-surface exposure of phosphatidylserine (PS) is essential for phagocytic clearance and blood clotting. Although a calcium-activated phospholipid scramblase (CaPLSase) has long been proposed to mediate PS exposure in red blood cells (RBCs), its identity, activation mechanism, and role in RBC biology and disease remain elusive. Here, we demonstrate that TMEM16F, the long-sought-after RBC CaPLSase, is activated by calcium influx through the mechanosensitive channel PIEZO1 in RBCs. PIEZO1-TMEM16F functional coupling is enhanced in RBCs from individuals with hereditary xerocytosis (HX), an RBC disorder caused by PIEZO1 gain-of-function channelopathy. Enhanced PIEZO1-TMEM16F coupling leads to an increased propensity to expose PS, which may serve as a key risk factor for HX clinical manifestations including anemia, splenomegaly, and postsplenectomy thrombosis. Spider toxin GsMTx-4 and antigout medication benzbromarone inhibit PIEZO1, preventing force-induced echinocytosis, hemolysis, and PS exposure in HX RBCs. Our study thus reveals an activation mechanism of TMEM16F CaPLSase and its pathophysiological function in HX, providing insights into potential treatment., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Objectives: Painful vaso-occlusive episodes (VOE) are the most common reason for emergency department (ED) visits experienced by patients with sickle cell disease (SCD). The National Heart, Lung and Blood Institute (NHLBI) evidence-based recommendations for VOE treatment are based primarily on expert opinion. In this randomized controlled trial (RCT), we will compare changes in pain scores between patients randomized to a patient-specific analgesic protocol versus those randomized to a weight-based analgesic protocol, as recommended by the NHLBI guidelines., Methods: We report the rationale and design of a multi-site, phase III, single-blinded, RCT to be conducted in six EDs in the United States. Eligible participants will be randomized after providing consent, anticipating 50% of those randomized would have an ED visit during the enrollment period. A total of 230 participants with one VOE ED visit provides sufficient power to detect a clinically significant difference in pain score reductions of 14 between groups with 0.05 type I error. Uniquely, this trial randomizes participants in a larger population than the study population, given the impossibility of consenting and randomizing participants during emergencies. The primary endpoint is the change in pain scores in the ED from time of placement in treatment area to time of disposition (hospitalization, discharged home, or assigned to observation status) or a maximum treatment duration of 6 hours. Additional outcomes include hospitalizations and ED visits seven days post enrollment, side effects, and safety assessments., Conclusions: The COMPARE-VOE study design will provide high-level evidence to support the NHLBI VOE treatment guidelines., (Copyright © 2020 Elsevier Inc. All rights reserved.)

This review highlights the concepts, recent applications and limitations of High Throughput Screening (HTS) flow cytometry-based efflux inhibitory assays. This platform has been employed in mammalian and yeast efflux systems leading to the identification of small molecules with transporter inhibitory capabilities. This technology offers the possibility of substrate multiplexing and may promote novel strategies targeting microbial efflux systems. This platform can generate a comprehensive dataset that may support efforts to map the interface between chemistry and transporter biology in a variety of pathogenic systems.

ATP binding cassette (ABC) transmembrane efflux pumps such as P-glycoprotein (ABCB1), multidrug resistance protein 1 (ABCC1), and breast cancer resistance protein (ABCG2) play an important role in anticancer drug resistance. A large number of structurally and functionally diverse compounds act as substrates or modulators of these pumps. In vitro assessment of the affinity of drug candidates for multidrug resistance proteins is central to predict in vivo pharmacokinetics and drug-drug interactions. The objective of this study was to identify and characterize new substrates for these transporters. As part of a collaborative project with Life Technologies, 102 fluorescent probes were investigated in a flow cytometric screen of ABC transporters. The primary screen compared substrate efflux activity in parental cell lines with their corresponding highly expressing resistant counterparts. The fluorescent compound library included a range of excitation/emission profiles and required dual laser excitation as well as multiple fluorescence detection channels. A total of 31 substrates with active efflux in one or more pumps and practical fluorescence response ranges were identified and tested for interaction with eight known inhibitors. This screening approach provides an efficient tool for identification and characterization of new fluorescent substrates for ABCB1, ABCC1, and ABCG2., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The most common form of neurologic injury in sickle cell anemia (SCA) is silent cerebral infarction (SCI). In the Silent Cerebral Infarct Multi-Center Clinical Trial, we sought to identify risk factors associated with SCI. In this cross-sectional study, we evaluated the clinical history and baseline laboratory values and performed magnetic resonance imaging of the brain in participants with SCA (HbSS or HbSβ° thalassemia) between the ages of 5 and 15 years with no history of overt stroke or seizures. Neuroradiology and neurology committees adjudicated the presence of SCI. SCIs were diagnosed in 30.8% (251 of 814) participants who completed all evaluations and had valid data on all prespecified demographic and clinical covariates. The mean age of the participants was 9.1 years, with 413 males (50.7%). In a multivariable logistic regression analysis, lower baseline hemoglobin concentration (P < .001), higher baseline systolic blood pressure (P = .018), and male sex (P = .030) were statistically significantly associated with an increased risk of an SCI. Hemoglobin concentration and systolic blood pressure are risk factors for SCI in children with SCA and may be therapeutic targets for decreasing the risk of SCI. This study is registered at www.clinicaltrials.gov as #NCT00072761.

Objective: Children with sickle cell disease (SCD) often receive care in the emergency department (ED), but the urgency of these frequent visits is not well understood. This study examined ED use by children with SCD by comparing the urgency of ED visits among children with SCD, asthma, and diabetes mellitus., Methods: We conducted a retrospective cohort study of Maryland ED visits for SCD, diabetes, or asthma from 2000 to 2004. ED visits resulting in hospital admission were deemed urgent. The urgency of ED visits not resulting in admission was determined using 2 methodologies: evaluation and management (E/M) coding and resource utilization. Multivariable logistic regression models were used to compare the likelihood of admission or urgent, treat-and-release ED visits across the 3 chronic conditions., Results: Nearly half (45%) of ED visits with a primary diagnosis of SCD resulted in admission, which was substantially higher than the 12% seen for asthma (adjusted odds ratio [AOR] 6.9, 95% confidence interval [CI], 6.4-7.4) and comparable to that seen for diabetes (41%). ED visits associated with primary diagnoses of SCD (AOR 5.9, 95% CI, 5.3-6.5) and diabetes (AOR 6.6, 95% CI, 6.0-7.3) were more likely than those associated with asthma to result in either admission or a discharge of higher urgency, as measured by E/M coding. These relationships persisted among repeat ED visitors, for visits with any diagnosis (ie, primary or nonprimary) of SCD, diabetes, and asthma, and when evaluated using the resource utilization method., Conclusions: Similar to visits by children with diabetes, ED visits by children with SCD are substantially more likely than those by children with asthma to be of high urgency., (Copyright © 2011 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.)

Influenza causes excess morbidity in sickle cell disease (SCD). H1N1 pandemic influenza has been severe in children. To compare H1N1 with seasonal influenza in SCD (patients younger than 22), we reviewed medical records (1993-2009). We identified 123 cases of laboratory-confirmed influenza (94 seasonal, 29 H1N1). Those with seasonal influenza were younger (median 4.4 vs 8.7 years old, P = .006) and had less asthma (24% vs 56%, P = .002). Those with H1N1 influenza more often had acute chest syndrome (ACS; 34% vs 13%, P = .01) and required intensive care (17% vs 3%, P = .02), including mechanical ventilation (10% vs 0%, P = .02). In multivariate analysis, older age (odds ratio [OR] 1.1 per year, P = .04) and H1N1 influenza (OR 3.0, P = .04) were associated with ACS, and older age (OR 1.1 per year, P = .02) and prior ACS (OR 3.3 per episode in last year, P < .006) with intensive care. Influenza, especially H1N1, causes critical illness in SCD and should be prevented.

Clinical experts have expressed concern about underutilization of sickle cell disease (SCD) therapies, including hydroxyurea, prophylactic antibiotics, iron chelation, bone marrow transplantation, pain management during vaso-occlusive crisis, and receipt of routine ambulatory health care. We synthesized studies that identified barriers to and interventions to improve appropriate use of these therapies. Of the 48 studies included in our review, 35 identified therapeutic barriers or facilitators, and 13 evaluated interventions to improve use of therapies. Consistently identified barriers to appropriate pain management were negative provider attitudes and lack of provider knowledge. Four of 9 pain management interventions improved direct measures of pain management quality, while 5 improved indirect measures. One intervention improved receipt of routine ambulatory care. We concluded that interventions to improve pain management in SCD can be effective and should address providers' negative attitudes and knowledge and that more intervention studies are needed to improve receipt of recommended SCD therapies.

As part of an ongoing effort to develop new antiviral nucleoside analogs, our interest was drawn to N(1)-aryl purines as a novel structural class and potential scaffold for drug discovery. Herein, we describe the synthesis of N(1)-3-fluorophenyl-inosine (FPI) and N(1)-3-fluorophenyl-hypoxanthine (FP-Hx) and their antiviral activity against hantaviruses. The EC(50) for FPI and FP-Hx were 94 and 234microM, respectively, against Hantaan virus. FPI was not toxic to mammalian cells at concentrations that exhibited antiviral activity. Analysis of its metabolism revealed a low conversion of FPI in Vero E6 or human cells to a 5'-triphosphate, and it was a poor substrate for human purine nucleoside phosphorylase. Further, the compound did not alter GTP levels indicating FPI does not inhibit inosine monophosphate dehydrogenase. With respect to the virus, FPI did not decrease viral RNA levels or increase the mutation frequency of the viral RNA. This suggests that the antiviral activity of FPI might be solely due to the interaction of FPI or its metabolites with viral or host proteins involved in post-replication events that would affect the levels of infectious virus released. Synthesis of other compounds structurally similar to FPI is warranted to identify more potent agents that selectively abrogate production of infectious virus.

Overt stroke, clinically "silent" cerebral infarct, and neurocognitive impairment are frequent complications of sickle cell anemia (SCA). Current imaging techniques have limited sensitivity and specificity to identify children at risk for neurocognitive impairment. We prospectively evaluated 24 children with SCA with a neurologic exam, complete blood count, transcranial Doppler ultrasound (TCD), measurement of intelligence quotient (IQ), and magnetic resonance imaging (MRI) with measurement of cerebral blood flow (CBF) using continuous arterial spin-labeling (CASL) MRI. Average CBF to gray matter was 112 +/- 36 mL/100 g/min. We identified a strong inverse relationship between performance IQ and CBF (-1.5 points per 10 mL/100 g/min increase in CBF, P = .013). Elevated steady-state white blood cell count (> or = 14 x 10(9)/L [14,000/microL]) was associated with lower full scale IQ (86 +/- 9 vs 99 +/- 10, P = .005). CASL MRI may identify children with neurocognitive impairment, before damage is evident by structural MRI or TCD.