Search

Background Ceftazidime-avibactam (caz-avi), a novel β-lactam/β-lactamase inhibitor, is commonly utilized for carbapenem-resistant gram-negative infections (CR-GNI). However, the benefits vs risks of combining caz-avi with other agents are unclear. Methods In this retrospective cohort study, inpatients with CR-GNI treated with caz-avi were identified at 9 U.S. hospitals. The impact of caz-avi monotherapy (MT) or combination therapy (CT; i.e., any concomitant use of gram-negative-active antibiotics) was studied using logistic regression, controlling for baseline patient and hospital factors. The primary outcome was in-hospital mortality or discharge to hospice (death), and secondary outcomes were length of stay (LOS), resolution of infectious signs and symptoms (clinical response), 90-day recurrent infection and future caz-avi–resistant organism. An adjusted odds ratio (aOR) with 95% confidence interval (CI) was used to assess the primary and secondary outcomes. Results 328/499 (65.7%) patients received caz-avi as targeted therapy for a CR-GNI. Overall patients treated with MT and CT were similar at baseline and had comparable baseline demographics although patients treated with CT were more likely to be in the ICU and receive a concomitant empiric in vitro-concordant antibiotic (table 1). The most common organism was Klebsiella spp. (44.6%) followed by Pseudomonas aeruginosa (27.7%) (table 2). Concomitant gram-negative agents are shown in table 3. Overall, 92 (28.1%) patients died and CT (vs MT) displayed similar adjusted mortality risk (27.7% vs 28.7%; aOR [95%CI]: 0.67 [0.34-1.33]) and LOS (19 [9, 37] and 20 [9, 42.5] days). CT (vs MT) was associated with greater odds of clinical response (aOR: 2.25 [95%CI:1.15-4.41]). Among survivors, similar rates of 90-day recurrent infection (50/154 (32.5%) were observed in CT vs 18/82 (22.0%) in MT group (p=0.09) and 5 (2.19%) patients had future infection with a caz-avi–resistant pathogen (3 in CT and 2 in MT group). Conclusion Compared to patients with CR-GNI treated with caz-avi alone, those who received CT including caz-avy had similar survival and LOS but higher clinical response. The role of CT in the era of novel antibiotics warrants additional study. Disclosures Helen W. Boucher, MD, American Society of Microbiology: Honoraria|Elsevier: Honoraria|Sanford Guide: Honoraria.

We present our experience with transcatheter vascular occlusion using 0.035-inch hydrogel expandable coils, which has been reported only in a few cases in the pediatric cardiology fields.This study is a retrospective analysis of all patients who underwent transcatheter embolization with 0.035-inch hydrogel coils at the Department of Pediatrics, Okayama University Hospital, between October 2018 and September 2020.Twenty patients with a median age of 5.1 years (0.05-26.0 years) and a median weight of 13.8 kg (3.0-56.8 kg) were included. A total of fifty-four 0.035-inch hydrogel coils, including 35 Azur 35 and nineteen Azur CX 35 coils (Terumo, Tokyo, Japan), were successfully deployed in 22 target vessels. The target vessels consisted of 10 aortopulmonary collaterals, 8 veno-venous collaterals, and 4 pulmonary arteriovenous malformations. We achieved technical success in all the target vessels. In total, the mean target vessel diameter was 4.4 mm, the mean number of 0.035-inch hydrogel coils was 2.5 per vessel. The mean device to vessel ratio was 1.6 for the anchor coil and 1.2 for the additional coil. Post-implantation angiograms revealed that the primary occlusion rate was 18/22 (82%). There were no periprocedural complications.The 0.035-inch hydrogel expandable coils are effective and safe in patients with congenital heart disease and vascular anomalies. These occlusion devices could be valuable options for interventional pediatric cardiologists.

A survey of acute-care hospitals found that rapid molecular diagnostic tests (RMDTs) have been widely adopted. Although many hospitals use their antimicrobial stewardship team and/or guidelines to help clinicians interpret results and optimize treatment, opportunities to more fully achieve the potential benefits of RMDTs remain.

Background: In recent years, several rapid molecular diagnostic tests (RMDTs) for infectious diseases diagnostics, such as bloodstream infections (BSIs), have become available for clinical use. The extent to which RMDTs have been adopted and how the results of these tests have been incorporated into clinical care are currently unknown. Methods: We surveyed members of the Society for Healthcare Epidemiology of America Research Network to characterize utilization of RMDT in hospitals and antimicrobial stewardship program (ASP) involvement in result communication and interpretation. The survey was administered using Qualtrics software, and data were analyzed using Stata and Excel software. Results: Overall, 57 responses were received (response rate, 59%), and 72% were from academic hospitals; 50 hospitals (88%) used at least 1 RMDT for BSI (Fig. 1). The factors most commonly reported to have been important in the decision to adopt RMDT were improvements in antimicrobial usage (82%), clinical outcomes (74%), and laboratory efficiency (52%). Among 7 hospitals that did not use RMDT for BSI, the most common reason was cost of new technology. In 50 hospitals with RMDT for BSI, 54% provided written guidelines for optimization or de-escalation of antimicrobials based upon RMDT results. In 40 hospitals (80%), microbiology laboratories directly notified a healthcare worker of the RMDT results: 70% provided results to a physician, nurse practitioner, or physician assistant; 48% to the ASP team; and 33% to a nurse. Furthermore, 11 hospitals (22%) had neither guidelines nor ASP intervention. In addition, 24 hospitals (48%) reported performing postimplementation evaluation of RMDT impact. Reported findings included reduction in time to antibiotic de-escalation (75%), reduction in length of stay (25%), improved laboratory efficiency (20%), and reduction in mortality and overall costs (12%). Among the 47 hospitals with both RMDT and ASP, 79% reported that the ASP team routinely reviewed blood culture RMDT results, and 53.2% used clinical decision support software to do so. Finally, 53 hospitals (93%) used 1 or more RMDT for non–bloodstream infections (Fig. 1). Fewer than half of hospitals provided written guidelines to assist clinicians in interpreting these RMDT results. Conclusions: RMDTs have been widely adopted by participating hospitals and are associated with positive self-reported clinical, logistic, and financial outcomes. However, nearly 1 in 4 hospitals did not have guidelines or ASP interventions to assist clinicians with optimization of antimicrobial prescribing based on RMDT results for BSI. Also, most hospitals did not have guidelines for RMDT results for non-BSI. These findings suggest that opportunities exist to further enhance the potential benefits of RMDT.Funding: NoneDisclosures: None

Background: Early de-escalation of antibiotics in sepsis may be safe and effective. In our study, we performed a retrospective chart review of patients admitted to a large municipal hospital who were treated for severe sepsis or septic shock to compare outcomes in patients who experienced early de-escalation (DEG) with outcomes of those who did not (NDG).Methods: The observational study was conducted at Bellevue Hospital Center (an 850-bed municipal hospital affiliated with New York University School of Medicine, New York, NY). Patients admitted from January 1 to December 31, 2015, who were treated for severe sepsis or septic shock during any time of their hospital stay were reviewed for the study. De-escalation was defined as narrowing or discontinuation of 1 or more antimicrobial therapies < 3 days after sepsis onset. Results: Overall, 277 patients were included (DEG, 90 patients, 32%; NDG, 187 patients, 68%). The groups were similar in terms of sex, comorbidities, length of stay, and severity of illness: septic shock (47% DEG vs 49% NDG; P = .693) and ICU stay (27% DEG vs 32% NDG; P = .406). DEG patients were slightly older than NDG patients: (DEG age, 63+16 years vs NDE age, 58+16 years; P = .028). There was no difference in hospital mortality (8% DEG vs 12% NDE; P = .257). Nearly half of the patients in both groups (46% DEG and 47% NDG) had no causative microorganisms identified using conventional microbiology culture. The common sources of primary infection were respiratory, urinary tract, and gastrointestinal infections, and these were not different between groups. Also, 69% of DEG patients and 79% of NDG patients received antibiotics for >7 days (P = .002). Empiric intravenous vancomycin was initiated in 83% in DEG patients and 74% in NDG patients at sepsis diagnosis. Although organisms covered by intravenous vancomycin were isolated from only 17% of patients in DEG and 23% in NDG, vancomycin was continued for >5 days in 34% of DEG patients and 50.3% of NDG patients (P < .001). 60% of patients in DEG and 61% in NDG were seen by infectious diseases specialists (ID). Patients with infectious diseases consultations had significantly more comorbidities, were more frequently in the ICU, had higher MDRO isolation and longer hospital stays, but they were still de-escalated without a difference in mortality. Conclusions: Microbiology data did not contribute to early de-escalation of antibiotics in this study. This finding may be related to the high percentage of negative culture and unavailability of rapid molecular diagnostic tests. Shorter duration of antibiotics (including vancomycin) was not associated with worse outcome in these severely ill patients.Funding: NoneDisclosures: None

Background:Pulmonary vein stenosis (PVS) is a condition with challenging treatment and leads to severe cardiac failure and pulmonary hypertension. Despite aggressive surgical or catheter-based intervention, the prognosis of PVS is unsatisfactory. This study aimed to assess the prognosis and to establish appropriate treatment strategies.Methods:We retrospectively reviewed endovascular treatments for PVS (2001–2017) from the clinical database at the Okayama University Hospital.Results:A total of 24 patients underwent PVS associated with total anomalous pulmonary venous connection and 7 patients underwent isolated congenital PVS. In total, 53 stenotic pulmonary veins were subjected to endovascular treatments; 40 of them were stented by hybrid (29) and percutaneous procedures (11) (bare-metal stent, n = 34; drug-eluting stent, n = 9). Stent size of hybrid stenting was larger than percutaneous stenting. Median follow-up duration from the onset of PVS was 24 months (4–134 months). Survival rate was 71 and 49% at 1 and 5 years, respectively. There was no statistically significant difference between stent placement and survival; however, patients who underwent bare-metal stent implantation had statistically better survival than those who underwent drug-eluting stent implantation or balloon angioplasty. Early onset of stenosis, timing of stenting, and small vessel diameter of pulmonary vein before stenting were considered as risk factors for in-stent restenosis. Freedom from re-intervention was 50 and 26% at 1 and 2 years.Conclusions:To improve survival and stent patency, implantation of large stent is important. However, re-intervention after stenting is also significant to obtain good outcome.

Determining the causative etiology of culture-negative endocarditis can be challenging. We performed next-generation sequencing of plasma microbial cell-free DNA to facilitate rapid diagnosis and genotyping of Coxiella burnetii in a patient with culture-negative endocarditis of a prosthetic pulmonary valve, enabling early targeted treatment prior to valve replacement surgery.

Rationale: Patients with single ventricle physiology are at high risk of mortality resulting from ventricular dysfunction. The preliminary results of the phase 1 trial showed that cardiosphere-derived cells (CDCs) may be effective against congenital heart failure. Objective: To determine whether intracoronary delivery of autologous CDCs improves cardiac function in patients with single ventricle physiology. Methods and Results: We conducted a phase 2 randomized controlled study to assign in a 1:1 ratio 41 patients who had single ventricle physiology undergoing stage 2 or 3 palliation to receive intracoronary infusion of CDCs 4 to 9 weeks after surgery or staged reconstruction alone (study A). The primary outcome measure was to assess improvement in cardiac function at 3-month follow-up. Four months after palliation, controls had an alternative option to receive late CDC infusion on request (study B). Secondary outcomes included ventricular function, heart failure status, somatic growth, and health-related quality of life after a 12-month observation. At 3 months, the absolute changes in ventricular function were significantly greater in the CDC-treated group than in the controls (+6.4% [SD, 5.5] versus +1.3% [SD, 3.7]; P =0.003). In study B, a late CDC infusion in 17 controls increased the ventricular function at 3 months compared with that at baseline (38.8% [SD, 7.7] versus 34.8% [SD, 7.4]; P P P P P P =0.014) relative to baseline. Conclusions: Intracoronary infusion of CDCs after staged palliation favorably affected cardiac function by reverse remodeling in patients with single ventricle physiology. This impact may improve heart failure status, somatic growth, and quality of life in patients and reduce parenting stress for their families. Clinical Trial Registration: URL: http://www.clinicaltrials.gov . Unique identifier: NCT01829750.

Asians have specific characteristics of hypertension (HTN) and its relationship with cardiovascular disease. The morning surge in blood pressure (BP) in Asians is more extended, and the association slope between higher BP and the risk for cardiovascular events is steeper in this population than in whites. Thus, 24-hour BP control including at night and in the morning is especially important for Asian patients with HTN. There are 3 components of “perfect 24-hour BP control”: the 24-hour BP level, adequate dipping of nocturnal BP (dipper type), and adequate BP variability such as the morning BP surge. The morning BP-guided approach using home BP monitoring (HBPM) is the first step toward perfect 24-hour BP control. After controlling morning HTN, nocturnal HTN is the second target. We have been developing HBPM that can measure nocturnal BP. First, we developed a semiautomatic HBPM device with the function of automatic fixed-interval BP measurement during sleep. In the J-HOP (Japan Morning Surge Home Blood Pressure) study, the largest nationwide home BP cohort, we successfully measured nocturnal home BP using this device with data memory, 3 times during sleep (2, 3, and 4 am), and found that nocturnal home BP is significantly correlated with organ damage independently of office and morning BP values. The second advance was the development of trigger nocturnal BP (TNP) monitoring with an added trigger function that initiates BP measurements when oxygen desaturation falls below a variable threshold continuously monitored by pulse oximetry. TNP can detect the specific nocturnal BP surges triggered by hypoxic episodes in patients with sleep apnea syndrome. We also added the lowest heart rate-trigger function to TNP to detect the “basal nocturnal BP,” which is determined by the circulating volume and structural cardiovascular system without any increase in sympathetic tonus. This double TNP is a novel concept for evaluating the pathogenic pressor mechanism of nocturnal BP. These data are now collected using an information and communication technology (ICT)-based monitoring system. The BP variability includes different time-phase variability from the shortest beat-by-beat, positional, diurnal, day-by-day, visit-to-visit, seasonal, and the longest yearly changes. The synergistic resonance of each type of BP variability would produce great dynamic BP surges, which trigger cardiovascular events. Thus, in the future, the management of HTN based on the simultaneous assessment of the resonance of all of the BP variability phenotypes using a wearable “surge” BP monitoring device with an ICT-based data analysis system will contribute to the ultimate individualized medication for cardiovascular disease.

Although cardiosphere-derived cells (CDCs) improve cardiac function and outcomes in patients with single ventricle physiology, little is known about their safety and therapeutic benefit in children with dilated cardiomyopathy (DCM). We aimed to determine the safety and efficacy of CDCs in a porcine model of DCM and translate the preclinical results into this patient population. A swine model of DCM using intracoronary injection of microspheres created cardiac dysfunction. Forty pigs were randomized as preclinical validation of the delivery method and CDC doses, and CDC-secreted exosome (CDCex)-mediated cardiac repair was analyzed. A phase 1 safety cohort enrolled five pediatric patients with DCM and reduced ejection fraction to receive CDC infusion. The primary endpoint was to assess safety, and the secondary outcome measure was change in cardiac function. Improved cardiac function and reduced myocardial fibrosis were noted in animals treated with CDCs compared with placebo. These functional benefits were mediated via CDCex that were highly enriched with proangiogenic and cardioprotective microRNAs (miRNAs), whereas isolated CDCex did not recapitulate these reparative effects. One-year follow-up of safety lead-in stage was completed with favorable profile and preliminary efficacy outcomes. Increased CDCex-derived miR-146a-5p expression was associated with the reduction in myocardial fibrosis via suppression of proinflammatory cytokines and transcripts. Collectively, intracoronary CDC administration is safe and improves cardiac function through CDCex in a porcine model of DCM. The safety lead-in results in patients provide a translational framework for further studies of randomized trials and CDCex-derived miRNAs as potential paracrine mediators underlying this therapeutic strategy.

Determining the causative etiology of culture-negative endocarditis can be challenging. We performed next-generation sequencing of plasma microbial cell-free DNA to facilitate rapid diagnosis and genotyping of Coxiella burnetii in a patient with culture-negative endocarditis of a prosthetic pulmonary valve, enabling early targeted treatment prior to valve replacement surgery.

Rationale: Hypoplastic left heart syndrome (HLHS) remains a lethal congenital cardiac defect. Recent studies have suggested that intracoronary administration of autologous cardiosphere-derived cells (CDCs) may improve ventricular function. Objective: The aim of this study was to test whether intracoronary delivery of CDCs is feasible and safe in patients with hypoplastic left heart syndrome. Methods and Results: Between January 5, 2011, and January 16, 2012, 14 patients (1.8±1.5 years) were prospectively assigned to receive intracoronary infusion of autologous CDCs 33.4±8.1 days after staged procedures (n=7), followed by 7 controls with standard palliation alone. The primary end point was to assess the safety, and the secondary end point included the preliminary efficacy to verify the right ventricular ejection fraction improvements between baseline and 3 months. Manufacturing and intracoronary delivery of CDCs were feasible, and no serious adverse events were reported within the 18-month follow-up. Patients treated with CDCs showed right ventricular ejection fraction improvement from baseline to 3-month follow-up (46.9%±4.6% to 52.1%±2.4%; P =0.008). Compared with controls at 18 months, cardiac MRI analysis of CDC-treated patients showed a higher right ventricular ejection fraction (31.5%±6.8% versus 40.4%±7.6%; P =0.049), improved somatic growth ( P =0.0005), reduced heart failure status ( P =0.003), and lower incidence of coil occlusion for collaterals ( P =0.007). Conclusions: Intracoronary infusion of autologous CDCs seems to be feasible and safe in children with hypoplastic left heart syndrome after staged surgery. Large phase 2 trials are warranted to examine the potential effects of cardiac function improvements and the long-term benefits of clinical outcomes. Clinical Trial Registration: URL: http://www.clinicaltrials.gov . Unique identifier: NCT01273857.

The solubilization abilities of various kinds of surfactants are clarified through a systematic solubilization study. Naphthalene and octafluoronaphthalene have similar molecular structures and can be used as solubilizates in hydrocarbon and fluorocarbon surfactant systems. The solubilizaton quantities are measured for typical anionic, cationic, and cationic gemini surfactants with different alkyl chain lengths (nine hydrocarbon and six fluorocarbon surfactants). The maximum solubilization quantities of naphthalene and octafluoronaphthalene in aqueous solutions of hydrocarbon or fluorocarbon surfactant are measured as a function of surfactant concentration at 318.2 K. There are four solubilization systems regarding hydrocarbons and fluorocarbons. Judging from the molar solubilization ratio (MSR), naphthalene is solubilized most in typical gemini surfactant solution (12-2-12), whereas hardly any naphthalene is solubilized in fluorocarbon surfactants. On the other hand, the maximum MSR of octafluoronaphthalene is found for the gemini type of fluorocarbon surfactant, whereas the minimum value is recorded in the C9H19COONa system. Therefore, gemini surfactants reveal excellent solubilization abilities in homogeneous combination systems. The solubilization stability can be analyzed by estimating the Gibbs free energy change (ΔG°) for the transfer of solubilizate molecules to the aggregate phase. The largest negative value of ΔG° is estimated to be −34.8 kJ mol−1 for the homogeneous system of octafluoronaphthalene and the gemini-type fluorocarbon surfactant, whereas smaller values are obtained for the heterogeneous systems of naphthalene and fluorocarbon surfactants. These results indicate that fluorocarbon surfactants are not generally suitable for the solubilization of naphthalene.

Background Identification of Coxiella burnetii, the etiologic agent of Q Fever, in culture-negative endocarditis (CNE) remains challenging, and strain-level information is typically unavailable through conventional testing. We used a novel next-generation sequencing (NGS) assay on plasma cell-free DNA to facilitate rapid diagnosis and genotyping in a patient with C. burnetii CNE. Methods NGS was performed on plasma by Karius, Inc. (Redwood City, California). Human reads were removed and remaining sequences were aligned to a curated database of over 1,000 pathogens. Organisms present above a predefined significance threshold were reported. For C. burnetti strain-typing, alignments to different Coxiella strains in the pathogen database were compared by BLAST bit-score to determine the most closely related strain to the infecting organism. C. burnetii genotype group was also determined by in silico analysis of polymorphic ORF deletion markers known to distinguish groups I–VI. Results Twenty-nine-year-old male with history of Tetralogy of Fallot, multiple pulmonary valve replacement (PVR), and 18 months of intermittent fever and night sweats were admitted. Relevant history included travel in South and South East Asia, the use of a LivaNova 3T Heater-Cooler device during surgery (i.e., at risk for Mycobacterium chimaera), and drinking unpasteurized milk. Cardiac CT showed 2 pulmonary opacities concerning for septic emboli and echocardiography showed echodensity on pulmonic valve. Blood cultures were negative. NGS detected C. burnetii within 48 hours of sample receipt. On the basis of these results, hydroxychloroquine and doxycycline were initiated with symptomatic improvement. Strain-typing demonstrated highest relatedness to the CbuK_Q154 (group IV) strain typically seen in North America. Genotype group was independently confirmed by inference of a pattern of ORF deletion most similar to group IV (and highly related group VII). Serologic testing for C. burnetii confirmed the diagnosis. After 4 weeks of antibiotics, the patient underwent successful PVR with graft exchange. Conclusion NGS testing aided in diagnosis of C. burnetii CNE, enabling early targeted antimicrobial therapy. It also allowed inference of strain-level information, supporting further investigations regarding epidemiologic origins of this pathogen. Disclosures S. Dalai, Karius, Inc.: Consultant, Consulting fee. S. Venkatasubrahmanyam, Karius, Inc.: Employee, Salary.

Objective We sought to evaluate the efficacy of balloon angioplasty (BA) for severely desaturated patients due to a stenotic right ventricle (RV) to pulmonary artery (PA) shunt following modified Norwood procedure. Methods Of 87 patients who underwent a Norwood procedure with the RV-PA shunt between February 1998 through March 2010, 22 (25%) patients underwent BA. The efficacy of BA was assessed by angiographic measurement of the changes in the internal diameters of the stenotic portions of the shunt, changes in arterial saturation and clinical outcomes. Results BA was performed for stenotic RV-PA shunts following stage I palliation (n = 17, 77%), or those placed as an additional blood source (n = 5, 23%, 3 patients awaiting biventricular repair, 2 patients following stage II palliation). The location of the BA was at the distal anastomosis in 12 (54.5%), proximal anastomosis in 21 (95.4%) and in the mid-portion of the shunt in 11 (50%) cases. The diameters of these three shunt portions were measured from the anteriorposterior and lateral angiographic images, increasing significantly after BA (p < 0.0001) in all. Arterial saturation significantly improved after BA in all cases (66.5 +/- 4.3% to 79.4 +/- 3.4%, p < 0.0001). Freedom from reintervention was 100%. All patients underwent subsequent elective planned surgery at an appropriate age with no mortality. Conclusions A BA-alone strategy for a stenotic RV-PA shunt was effective for all three shunt portions, minimizing shunt-related premature surgical intervention.

During murine embryogenesis, the Ets factor Erg is highly expressed in endothelial cells of the developing vasculature and in articular chondrocytes of developing bone. We identified seven isoforms for the mouse Erg gene. Four share a common translational start site encoded by exon 3 (Ex3) and are enriched in chondrocytes. The other three have a separate translational start site encoded by Ex4 and are enriched in endothelial cells. Homozygous ErgΔEx3/ΔEx3 knockout mice are viable, fertile and do not display any overt phenotype. By contrast, homozygous ErgΔEx4/ΔEx4 knockout mice are embryonic lethal, which is associated with a marked reduction in endocardial-mesenchymal transformation (EnMT) during cardiac valve morphogenesis. We show that Erg is required for the maintenance of the core EnMT regulatory factors that include Snail1 and Snail2 by binding to their promoter and intronic regions.

E26 transformation-specific sequence (ETS) factors are a family of transcription factors that share a highly conserved DNA-binding domain. The name ETS originates from a sequence that was detected in an avian erythroblastosis virus, E26, where it formed a transforming gene together with Δgag and c-myb.1,2 There are ~25–30 ETS family members in a variety of species from drosophila to man. ETS factors are involved in regulating a wide variety of biological processes including normal development and differentiation.3 As proto-oncogenes they have also been implicated in the pathogenesis of several different types of cancer.4,5 The epithelium-specific ETS transcription factor-1 (ESE-1) was originally identified as an epithelial-restricted ETS factor.6 Under noninflammatory conditions, ESE-1 is only expressed in cells of epithelial origin. However, in response to inflammatory stimuli such as endotoxin or proinflammatory cytokines including interleukin-1β (IL-1β) or tumor necrosis factor-α (TNF-α), this transcription factor is highly induced in cultured primary endothelial cells or vascular smooth muscle cells (VSMCs).7 In a mouse model of endotoxemia, ESE-1 is rapidly induced in the endothelium and first medial layer of VSMC of the mouse aorta.7 Target genes regulated by ESE-1 include nitric oxide synthase 2 (NOS2) and cyclooxygenase 2 (COX2).7,8 ESE-1 has also recently been shown to function in the regulation of TNF-α-mediated expression of angiopoietin-1 in the setting of inflammatory arthritis.9 The transcriptional activity of ESE-1 can be positively and negatively modified by its interaction with other proteins. Whereas binding of ESE-1 to CBP and p300 is associated with an increase in the transcriptional activity of ESE-1, interaction with Ku proteins represses ESE-1 function.10 ETS factors have also been shown to play an important role in angiotensin II (Ang II)–mediated vascular inflammation and remodeling. In particular, we have previously shown that the prototypic member of the ETS family, Ets-1, is a critical transcriptional mediator of Ang II–mediated vascular inflammatory responses.11 The participation of other selected ETS factors in vascular inflammation was recently reviewed.12 However, the role of ESE-1 in Ang II–mediated vascular inflammation and remodeling has not previously been explored. The primary purpose of this study was to determine whether ESE-1 expression is similarly induced in vivo, in the vasculature, in response to Ang II stimulation, and secondarily to determine whether or not ESE-1 plays an important modulatory role by positively or negatively regulating vascular inflammatory responses to Ang II.

Objective— MicroRNA plays important roles in vascular biology, but the regulation of endothelial-specific microRNA is not well characterized. MicroRNA-126 (miR-126) is highly expressed in endothelial cells, and it regulates angiogenesis and vascular inflammation. Here we show that the transcription factors Ets-1 and Ets-2 regulate miR-126 expression. Methods and Results— A genomic region between −71 and −100 bp upstream of the miR-126 transcriptional start site is critical for transactivation of the gene containing miR-126. This genomic region contains a potential Ets binding site. Mutations within the Ets binding site block transactivation, and Ets-1 and Ets-2 interact with this critical genomic region. Knockdown of endogenous Ets-1 and Ets-2 decreases miR-126 expression. Finally, knockdown of miR-126 alters regulation of an Ets-1 target gene. Conclusion— Taken together, these data show that the transcription factors Ets-1 and Ets-2 play a key role in controlling the expression of miR-126 and suggest that miR-126 may mediate some of their vascular effects.

Nuclear proteins have essential roles in cell proliferation and differentiation. We have developed a yeast selection system-the nuclear transportation trap (NTT)-to identify genes encoding nuclear transport signals. Both unknown and previously identified nuclear localization signals were identified from a human fetal brain cDNA library. The majority (75%) of the unknown proteins examined were exclusively localized to the nucleus in COS-7 cells. We propose that NTT is an efficient method for isolating cDNAs that encode nuclear targeted proteins that can be applied to the retrieval of novel nuclear proteins and to annotate gene function.

ETS-related gene (ERG) is a member of the ETS transcription factor family. Our previous studies have shown that ERG expression is highly enriched in endothelial cells (EC) both in vitro and in vivo. ERG expression is markedly repressed in response to inflammatory stimuli. It has been shown that ERG is a positive regulator of several EC-restricted genes including VE-cadherin, endoglin, and von Willebrand factor, and a negative regulator of other genes such as interleukin (IL)-8 and intercellular adhesion molecule (ICAM)-1. In this study we have identified a novel role for ERG in the regulation of EC barrier function. ERG knockdown results in marked increases in EC permeability. This is associated with a significant increase of stress fiber and gap formation in EC. Furthermore, we identify CLDN5 as a downstream target of ERG in EC. Thus, our results suggest that ERG plays a pivotal role in regulating EC barrier function and that this effect is mediated in part through its regulation of CLDN5 gene expression.

Background The molecular mechanisms that govern stem cell differentiation along the endothelial lineage remain largely unknown. Ets related gene (ERG) has recently been shown to participate in the transcriptional regulation of a number of endothelial specific genes including VE-cadherin (CD144), endoglin, and von Willebrand's Factor (vWF). The specific role of the ETS factor ERG during endothelial differentiation has not been evaluated. Results ERG expression and function were evaluated during the differentiation of embryonic stem cells into embryoid bodies (EB). The results of our study demonstrate that ERG is first expressed in a subpopulation of vascular endothelial growth factor receptor 2 (VEGF-R2) expressing cells that also express VE-cadherin. During ES cell differentiation, ERG expression remains restricted to cells of the endothelial lineage that eventually coalesce into primitive vascular structures within embryoid bodies. ERG also exhibits an endothelial cell (EC)-restricted pattern during embryogenesis. To further define the role of ERG during ES cell differentiation, we used a knockdown strategy to inhibit ERG expression. Delivery of three independent shRNA led to 70-85% reductions in ERG expression during ES cell differentiation compared to no change with control shRNA. ERG knockdown was associated with a marked reduction in the number of ECs, the expression of EC-restricted genes, and the formation of vascular structures. Conclusion The ETS factor ERG appears to be a critical regulator of EC differentiation.

ERG (Ets-related gene) is an ETS transcription factor that has recently been shown to regulate a number of endothelial cell (EC)-restricted genes including VE-cadherin, von Willebrand factor, endoglin, and intercellular adhesion molecule-2. Our preliminary data demonstrate that unlike other ETS factors, ERG exhibits a highly EC-restricted pattern of expression in cultured primary cells and several adult mouse tissues including the heart, lung, and brain. In response to inflammatory stimuli, such as tumor necrosis factor-α, we observed a marked reduction of ERG expression in ECs. To further define the role of ERG in the regulation of normal EC function, we used RNA interference to knock down ERG. Microarray analysis of RNA derived from ERG small interfering RNA– or tumor necrosis factor-α–treated human umbilical vein (HUV)ECs revealed significant overlap ( P

In Alzheimer's disease the major pathological feature observed is the progressive deposition of insoluble senile amyloid plaques within the cerebral cortex. The major component of these plaques is amyloid beta (Aβ), a 39-43 residue peptide. This peptide can be present as monomers with soluble disordered structure, which change conformation into partially folded intermediates and further assemble to form dimers, trimers, oligomers, protofibrils and larger fibrils. Earlier studies have suggested that neurotoxicity of the disease lies not in the insoluble fibrils but in the formation of soluble oligomers, which impair and alter neurotransmision. Thus, the solution conformation of Aβ is of significant interest for understanding the molecular mechanism of Aβ fibrillogenesis. In the present study we have investigated the process of fibril formation in the 25 residue Aβ(10-35) which has a similar fibril structure as Aβ40 and Aβ42. In addition, Aβ(10-35) contains the central hydrophobic cluster (residues 17-21) suspected to initiate folding.We have employed fluorescence, circular dichroism (CD) and time-dependent UVRR spectroscopic methods to explore the fibril formation process in vitro. Thioflavin-T induced fluorescence and CD studies indicate a conformational transition from an unfolded to β-sheet structure. UVRR studies conducted with 215 nm and 230 nm excitation facilitate characterization of the two phenylalanine and one tyrosine residues in the peptide, respectively. It is observed that formation of soluble Aβ oligomers is accompanied by a decrease in the intensities of the Phe vibrational mode, v8a (1606 cm-1) and the Tyr vibrational mode, v8a (1617 cm-1) over a 150 min incubation period. These results indicate that fibril formation proceeds via phenylalanine and tyrosine π-stacking interactions, which stabilize parallel β-sheets and reduce solvent exposure. Based on these results we have proposed a probable mechanism of fibril formation in Aβ(10-35).

not Available.