Wnt signaling positively regulates endothelial cell fate specification in the Fli1a-positive progenitor population via Lef1.

During vertebrate embryogenesis, vascular endothelial cells (ECs) and primitive erythrocytes become specified within close proximity in the posterior lateral plate mesoderm (LPM) from a common progenitor. However, the signaling cascades regulating the specification into either lineage remain largely elusive. Here, we analyze the contribution of ß-catenin dependent Wnt signaling to EC and erythrocyte specification during zebrafish embryogenesis. We generated novel ß-catenin dependent Wnt signaling reporters which, by using destabilized fluorophores (Venus-Pest, dGFP), specifically allow us to detect Wnt signaling responses in narrow time windows as well as in spatially restricted domains, defined by Cre recombinase expression (Tg(axin2BAC:Venus-Pest)mu288; Tg(14TCF:loxP-STOP-loxP-dGFP)mu202). We therefore can detect ß-catenin dependent Wnt signaling activity in a subset of the Fli1a-positive progenitor population. Additionally, we show that mesodermal Wnt3a-mediated signaling via the transcription factor Lef1 positively regulates EC specification (defined by kdrl expression) at the expense of primitive erythrocyte specification (defined by gata1 expression) in zebrafish embryos. Using mesoderm derived from human embryonic stem cells, we identified the same principle of Wnt signaling dependent EC specification in conjunction with auto-upregulation of LEF1. Our data indicate a novel role of ß-catenin dependent Wnt signaling in regulating EC specification during vasculogenesis.

Rheumatic heart disease in Timor-Leste school students: an echocardiography-based prevalence study.

OBJECTIVES: To determine the prevalence of rheumatic heart disease (RHD) in school-aged children and young people in Timor-Leste. DESIGN: Prospective cross-sectional survey. Echocardiography was performed by Australian cardiologists to determine the presence of RHD. Demographic data were also collected. Patients in whom RHD was detected were entered into a register to allow monitoring of adherence to secondary prophylaxis; the first dose of benzathine penicillin G (BPG) was administered on the day of screening. SETTING: Schools in urban (Dili) and rural (Ermera) Timor-Leste. PARTICIPANTS: School students aged 5-20 years. OUTCOME MEASURES: Definite and borderline RHD, as defined by World Heart Federation echocardiographic criteria. RESULTS: 1365 participants were screened; their median age was 11 years (IQR, 9-14 years), and 53% were girls. The estimated prevalence of definite RHD was 18.3 cases per 1000 population (95% CI, 12.3-27.0 per 1000), and of definite or borderline RHD 35.2 per 1000 (95% CI, 26.5-46.4 per 1000). Definite (adjusted odds ratio [aOR], 3.5; 95% CI, 1.3-9.4) and definite or borderline RHD (aOR, 2.7; 95% CI, 1.4-5.2) were more prevalent among girls than boys. Eleven children (0.8%) had congenital heart disease. Of the 25 children in whom definite RHD was identified, 21 (84%) received education and a first dose of BPG on the day of screening; all 25 have since received education about primary care for RHD and have commenced penicillin prophylaxis. CONCLUSIONS: The rates of RHD in Timor-Leste are among the highest in the world, and prevalence is higher among girls than boys. Community engagement is essential for ensuring follow-up and the effective delivery of secondary prophylaxis.

Isolation of circulating endothelial cells provides tool to determine endothelial cell senescence in blood samples.

Circulating endothelial cells (CEC) are arising as biomarkers for vascular diseases. However, whether they can be utilized as markers of endothelial cell (EC) senescence in vivo remains unknown. Here, we present a protocol to isolate circulating endothelial cells for a characterization of their senescent signature. Further, we characterize different models of EC senescence induction in vitro and show similar patterns of senescence being upregulated in CECs of aged patients as compared to young volunteers. Replication-(ageing), etoposide-(DNA damage) and angiotensin II-(ROS) induced senescence models showed the expected cell morphology and proliferation-reduction effects. Expression of senescence-associated secretory phenotype markers was specifically upregulated in replication-induced EC senescence. All models showed reduced telomere lengths and induction of the INK4a/ARF locus. Additional p14ARF-p21 pathway activation was observed in replication- and etoposide-induced EC senescence. Next, we established a combined magnetic activated- and fluorescence activated cell sorting (MACS-FACS) based protocol for CEC isolation. Interestingly, CECs isolated from aged volunteers showed similar senescence marker patterns as replication- and etoposide-induced senescence models. Here, we provide first proof of senescence in human blood derived circulating endothelial cells. These results hint towards an exciting future of using CECs as mirror cells for in vivo endothelial cell senescence, of particular interest in the context of endothelial dysfunction and cardiovascular diseases.

Physical therapy in the Emergency Department: A prospective cohort study from an Alternatives to Opioids program.

Objective: Musculoskeletal pain complaints are common in the emergency department (ED). The objective of this study was to determine the impact of physical therapy (PT) in the ED on pain and ED return. Methods: A prospective cohort study was performed with those presenting to the ED or Urgent Care at a single academic center for musculoskeletal pain between November 2020 and December 2022. All patients were referred to outpatient PT. During business hours, PT was available to begin treatment in the ED. Long-term follow-up was performed using the electronic health records. Statistical analyses included descriptive and non-parametric pairwise comparisons, Fisher's exact test, and multiple logistic regression. Results: A total of 974 patients were included in the study with 553 completing optional surveys. Back pain was most common. Pain was reduced at ED discharge for all patients, but pain was significantly improved if patients saw PT in the ED. Patients in the ED were less likely to keep their outpatient PT appointments than others, but importantly, patients who saw PT in the ED were less likely to return to the ED for the same complaint up to 1 year later. Those who kept PT appointments were likely to establish or maintain healthcare outside emergency services later. Conclusions: Initiating PT in this ED reduces pain at ED discharge. However, patients who utilized PT were more likely to later utilize health care resources outside of emergency services. Those who saw PT in this ED were less likely to return to the ED for the same complaint up to 1 year later.

Empagliflozin prevents neointima formation by impairing smooth muscle cell proliferation and accelerating endothelial regeneration.

Background: Empagliflozin, an inhibitor of the sodium glucose co-transporter 2 (SGLT2) and developed as an anti-diabetic agent exerts additional beneficial effects on heart failure outcomes. However, the effect of empagliflozin on vascular cell function and vascular remodeling processes remains largely elusive. Methods/Results: Immunocytochemistry and immunoblotting revealed SGLT2 to be expressed in human smooth muscle (SMC) and endothelial cells (EC) as well as in murine femoral arteries. In vitro, empagliflozin reduced serum-induced proliferation and migration of human diabetic and non-diabetic SMCs in a dose-dependent manner. In contrast, empagliflozin significantly increased the cell count and migration capacity of human diabetic ECs, but not of human non-diabetic ECs. In vivo, application of empagliflozin resulted in a reduced number of proliferating neointimal cells in response to femoral artery wire-injury in C57BL/6J mice and prevented neointima formation. Comparable effects were observed in a streptozocin-induced diabetic model of apolipoprotein E-/- mice. Conclusive to the in vitro-results, re-endothelialization was not significantly affected in C57BL/6 mice, but improved in diabetic mice after treatment with empagliflozin assessed by Evan's Blue staining 3 days after electric denudation of the carotid artery. Ribonucleic acid (RNA) sequencing (RNA-seq) of human SMCs identified the vasoactive peptide apelin to be decisively regulated in response to empagliflozin treatment. Recombinant apelin mimicked the in vitro-effects of empagliflozin in ECs and SMCs. Conclusion: Empagliflozin significantly reduces serum-induced proliferation and migration of SMCs in vitro and prevents neointima formation in vivo, while augmenting EC proliferation in vitro and re-endothelialization in vivo after vascular injury. These data document the functional impact of empagliflozin on vascular human SMCs and ECs and vascular remodeling in mice for the first time.

Long-term Experience with Rapid Screening for Platelet Bacterial Contamination in a High-volume Transfusion Service.

Bacterial sepsis after platelet transfusion is a major cause of transfusion-transmitted infections in the US. The Food and Drug Administration (FDA) recommends performing quality control for platelet bacterial detection on days 4 and 5 before platelet transfusion. We assessed the feasibility of implementing the Pan Genera Detection (PGD) test, an FDA-approved immunoassay for platelet bacterial detection, for the primary and secondary bacterial screening of platelet units in a high-volume setting. Records were reviewed from January 2010 through December 2015. All apheresis platelets underwent primary screening by using culture methods. Additional screening with the PGD test was performed daily until February 2013, when PGD testing of apheresis platelets was performed at the start of storage day 5. In April 2015, PGD testing of apheresis platelet products was performed at the start of storage day 4. Post-storage pooled whole blood-derived platelets were screened by using the PGD test on the day of use. During the 6-year study period, 16,839 PGD tests were performed. If the PGD test was reactive, repeat PGD testing was performed. In cases of repeat reactivity, units were quarantined and cultured. Initially, 42 (0.25%) tests were reactive; 26/42 (61.91%) were repeatedly reactive and resulted in an overall PGD repeat reactivity rate of 0.15%. Only one sample grew coagulase-negative Staphylococcus No transfusion-transmitted infections were reported. The PGD bacterial detection assay was feasible and efficient in our high-volume transfusion service.

Characteristics of thawed pooled cryoprecipitate stored at refrigerated temperature for 24 hours.

BACKGROUND: The need for thawed cryoprecipitate is growing. However, according to current guidelines, the shelf-life of pooled thawed cryoprecipitate at room temperature is limited because of possible bacterial contamination and loss of clotting factor activity. Here we assessed microbial growth and retention of clotting activity in cryoprecipitate stored at 4 °C after thawing to see whether its shelf life could be safely extended. MATERIALS AND METHODS: Pooled thawed cryoprecipitate units (n=10) were maintained at room temperature for 6 hours and then placed at 1-6 °C for 18 hours after thawing. We examined the cryoprecipitate pools for fibrinogen, factor VIII, and von Willebrand factor activity at the following time points: 0 hours (immediately after thawing), after 6 hours at room temperature, and after 24 hours at 1-6 °C. A 5-mL aliquot from each pool was collected for aerobic and anaerobic bacterial cultures at the 24-hour time point. RESULTS: Mean fibrinogen concentration and von Willebrand factor activity were similar at each time point, but factor VIII activity decreased significantly over the storage period. Bacterial growth was not detected in any cultured pooled sample. DISCUSSION: Extended storing of thawed cryoprecipitate at 1-6 °C does not appear to increase the risk of bacterial contamination or affect coagulation factor activity.

Scabies and impetigo in Timor-Leste: A school screening study in two districts.

INTRODUCTION: Scabies and impetigo are common and important skin conditions which are often neglected in developing countries. Limited data have been published on the prevalence of scabies and impetigo in Timor-Leste. Sequelae including cellulitis, bacteraemia, nephritis, acute rheumatic fever and rheumatic heart disease contribute significantly to the burden of disease. METHODS: School students were recruited from schools in Dili (urban) and Ermera (rural) in Timor-Leste for an epidemiological study in October 2016. A standard questionnaire was used to record demographics, anthropometry and skin examination results. Impetigo and scabies were diagnosed based on clinical examination of exposed surfaces, and clinical photographs were reviewed for correlation by an infectious diseases paediatrician. Prevalence of scabies and impetigo were calculated and binary risk factor associations were described using relative risks and 95% confidence intervals. Adjusted odds ratios were calculated using logistic regression multivariate analysis. Continuous variables were analysed for associations using the Mann-Whitney Rank Sum test. RESULTS: The study enrolled 1396 students; median age 11 years (interquartile range (IQR) 9-15). The prevalence of scabies was 22.4% (95% CI 20.2-24.7%) and active impetigo 9.7% (95% CI 8.3-11.4%); 68.2% of students had evidence of either active or healed impetigo. Students in Ermera were more likely than those in Dili to have scabies (prevalence 32.0% vs 5.2%, aOR 8.1 (95% CI 5.2-12.4), p<0.01). There was no difference in the prevalence of active impetigo between urban and rural sites. More than a third of participants were moderately or severely underweight. Stunting was markedly more common in the rural district of Ermera. CONCLUSION: Scabies and impetigo are common in Timor-Leste, with very high prevalence of scabies in the rural district of Ermera. Improvements in prevention and treatment are needed, with prioritised activities in the rural areas where prevalence is highest.

Sonic hedgehog-dependent activation of adventitial fibroblasts promotes neointima formation.

AIMS: Adventitial cells have been suggested to contribute to neointima formation, but the functional relevance and the responsible signalling pathways are largely unknown. Sonic hedgehog (Shh) is a regulator of vasculogenesis and promotes angiogenesis in the adult. METHODS AND RESULTS: Here we show that proliferation of vascular smooth muscle cells (SMC) after wire-induced injury in C57BL/6 mice is preceded by proliferation of adventitial fibroblasts. Simultaneously, the expression of Shh and its downstream signalling protein smoothened (SMO) were robustly increased within injured arteries. In vitro, combined stimulation with Shh and platelet-derived growth factor (PDGF)-BB strongly induced proliferation and migration of human adventitial fibroblasts. The supernatant of these activated fibroblasts contained high levels of interleukin-6 and -8 and strongly induced proliferation and migration of SMC. Inhibition of SMO selectively prevented fibroblast proliferation, cytokine release, and paracrine SMC activation. Mechanistically, we found that PDGF-BB activates protein kinase A in fibroblasts and thereby induces trafficking of SMO to the plasma membrane, where it can be activated by Shh. In vivo, SMO-inhibition significantly prevented the proliferation of adventitial fibroblasts and neointima formation following wire-induced injury. CONCLUSIONS: The initial activation of adventitial fibroblasts is essential for the subsequent proliferation of SMC and neointima formation. We identified SMO-dependent Shh signalling as a specific process for the activation of adventitial fibroblasts.