Effect of Various Toothpaste Tablets on Gloss and Surface Roughness of Resin-based Composite Materials

OBJECTIVES

To evaluate the effect of various toothpaste tablets on gloss and surface roughness of resin-based composite.

METHODS AND MATERIALS

Sixty-four resin-based composite specimens were divided into four groups of 16 specimens each. Gloss and roughness were measured before and after simulated brushing with three types of toothpaste tablets and one conventional toothpaste: CT: Chewtab Toothpaste Tablets; AT: Anticavity Toothpaste Tablets; HC: Charcoal Toothpaste Tablets; CP: Cavity Protection toothpaste. The Kruskal- Wallis procedure was performed to compare the differences by groups. Post-hoc comparisons were conducted with Bonferroni corrections (α=0.05).

RESULTS

There was a significant drop in gloss for all groups. CT and AT maintained the highest gloss with means of 81.6 GU and 74.1 GU, respectively. The lowest gloss of 24.5 GU was observed for HC. There was a significant increase in roughness for all groups except for CT. CT had the lowest roughness with a mean of 0.034 μm, while HC had the highest roughness with a mean of 0.074 μm. There was a significant correlation between post-brushing gloss and post-brushing roughness (p<0.001, r=-0.884).

CONCLUSION

Chewtab Toothpaste Tablets had the least effect on gloss and roughness, while Charcoal Toothpaste Tablets had the most negative effect on the surface properties of resin-based composites.

Passivation effect on Cd0.95Mn0.05Te0.98Se0.02 radiation detection performance

CdTe-based detectors have the problem of Te-rich surface layers caused by Br etching, which is one of fabrication steps. Te-rich layer acts as a trapping center and serves as an additional source of charge carriers, thereby degrading transport property of charge carriers and enriching leakage current on surface of detector. To solve this problem, we introduced sodium hypochlorite (NaOCl) as a passivant, and investigated its effect on Cd0.95Mn0.05Te0.98Se0.02 (CMTS), by analyzing chemical state of surface and its performance. After passivation with NaOCl, the results of X-ray photoelectron spectroscopy (XPS) shows the formation of tellurium oxide and elimination of water on CMTS surface, and CMTS presented enhanced performance with Am-241 radioisotope. Consequently, it is demonstrated that the passivation with NaOCl reduces leakage current, compensates defect, and elevates transport of charge carriers, thereby decreasing charge loss of carriers and improving performance of CMTS detector.

The Pathogenesis of Systemic Sclerosis: The Origin of Fibrosis and Interlink with Vasculopathy and Autoimmunity

Systemic sclerosis (SSc) is an autoimmune disease associated with increased mortality and poor morbidity, impairing the quality of life in patients. Whilst we know that SSc affects multiple organs via vasculopathy, inflammation, and fibrosis, its exact pathophysiology remains elusive. Microvascular injury and vasculopathy are the initial pathological features of the disease. Clinically, the vasculopathy in SSc is manifested as Raynaud's phenomenon (reversible vasospasm in reaction to the cold or emotional stress) and digital ulcers due to ischemic injury. There are several reports that medications for vasculopathy, such as bosentan and soluble guanylate cyclase (sGC) modulators, improve not only vasculopathy but also dermal fibrosis, suggesting that vasculopathy is important in SSc. Although vasculopathy is an important initial step of the pathogenesis for SSc, it is still unclear how vasculopathy is related to inflammation and fibrosis. In this review, we focused on the clinical evidence for vasculopathy, the major cellular players for the pathogenesis, including pericytes, adipocytes, endothelial cells (ECs), and myofibroblasts, and their signaling pathway to elucidate the relationship among vasculopathy, inflammation, and fibrosis in SSc.

Association of body mass index, metabolic health status and clinical outcomes in acute myocardial infarction patients: a national registry-based study

Introduction

Obesity is an important risk factor for acute myocardial infarction (AMI), but the interplay between metabolic health and obesity on AMI mortality has been controversial. In this study, we aimed to elucidate the risk of short- and long-term all-cause mortality by obesity and metabolic health in AMI patients using data from a multi-ethnic national AMI registry.

Methods

A total of 73,382 AMI patients from the national Singapore Myocardial Infarction Registry (SMIR) were included. These patients were classified into four groups based on the presence or absence of metabolic diseases, diabetes mellitus, hyperlipidaemia, and hypertension, and obesity: (1) metabolically-healthy-normal-weight (MHN); (2) metabolically-healthy-obese (MHO); (3) metabolically-unhealthy-normal-weight (MUN); and (4) metabolically-unhealthy-obese (MUO).

Results

MHO patients had reduced unadjusted risk of all-cause in-hospital, 30-day, 1-year, 2-year, and 5-year mortality following the initial MI event. However, after adjusting for potential confounders, the protective effect from MHO on post-AMI mortality was lost. Furthermore, there was no reduced risk of recurrent MI or stroke within 1-year from onset of AMI by the MHO status. However, the risk of 1-year mortality was higher in female and Malay AMI patients with MHO compared to MHN even after adjusting for confounders.

Conclusion

In AMI patients with or without metabolic diseases, the presence of obesity did not affect mortality. The exception to this finding were female and Malay MHO who had worse long-term AMI mortality outcomes when compared to MHN suggesting that the presence of obesity in female and Malay patients may confer worsened outcomes.

Comparison of the modified Singapore myocardial infarction registry risk score with GRACE 2.0 in predicting 1-year acute myocardial infarction outcomes

Risk stratification plays a key role in identifying acute myocardial infarction (AMI) patients at higher risk of mortality. However, current AMI risk scores such as the Global Registry of Acute Coronary Events (GRACE) score were derived from predominantly Caucasian populations and may not be applicable to Asian populations. We previously developed an AMI risk score from the national-level Singapore Myocardial Infarction Registry (SMIR) confined to ST-segment elevation myocardial infarction (STEMI) patients and did not include non-STEMI (NSTEMI) patients. Here, we derived a modified SMIR risk score for both STEMI and NSTEMI patients and compared its performance to the GRACE 2.0 score for predicting 1-year all-cause mortality in our multi-ethnic population. The most significant predictor of 1-year all-cause mortality in our population using the GRACE 2.0 score was cardiopulmonary resuscitation on admission (adjusted hazards ratio [HR] 6.50), while the most significant predictor using the SMIR score was age 80–89 years (adjusted HR 7.78). Although the variables used in the GRACE 2.0 score and SMIR score were not exactly the same, the c-statistics for 1-year all-cause mortality were similar between the two scores (GRACE 2.0 0.841 and SMIR 0.865). In conclusion, we have shown that in a multi-ethnic Asian AMI population undergoing PCI, the SMIR score performed as well as the GRACE 2.0 score.

Sine oculis homeobox homolog 1 plays a critical role in pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal disease with limited treatment options. The role of the developmental transcription factor Sine oculis homeobox homolog 1 (SIX1) in the pathophysiology of lung fibrosis is not known. IPF lung tissue samples and IPF-derived alveolar type II cells (AT2) showed a significant increase in SIX1 mRNA and protein levels, and the SIX1 transcriptional coactivators EYA1 and EYA2 were elevated. Six1 was also upregulated in bleomycin-treated (BLM-treated) mice and in a model of spontaneous lung fibrosis driven by deletion of Telomeric Repeat Binding Factor 1 (Trf1) in AT2 cells. Conditional deletion of Six1 in AT2 cells prevented or halted BLM-induced lung fibrosis, as measured by a significant reduction in histological burden of fibrosis, reduced fibrotic mediator expression, and improved lung function. These effects were associated with increased macrophage migration inhibitory factor (MIF) in lung epithelial cells in vivo following SIX1 overexpression in BLM-induced fibrosis. A MIF promoter-driven luciferase assay demonstrated direct binding of Six1 to the 5'-TCAGG-3' consensus sequence of the MIF promoter, identifying a likely mechanism of SIX1-driven MIF expression in the pathogenesis of lung fibrosis and providing a potentially novel pathway for targeting in IPF therapy.

Comparison of Mortality Outcomes in Acute Myocardial Infarction Patients With or Without Standard Modifiable Cardiovascular Risk Factors

Background

Acute myocardial infarction (AMI) cases have decreased in part due to the advent of targeted therapies for standard modifiable cardiovascular disease risk factors (SMuRF). Recent studies have reported that ST-elevation myocardial infarction (STEMI) patients without SMuRF (termed “SMuRF-less”) may be increasing in prevalence and have worse outcomes than “SMuRF-positive” patients. As these studies have been limited to STEMI and comprised mainly Caucasian cohorts, we investigated the changes in the prevalence and mortality of both SMuRF-less STEMI and non-STEMI (NSTEMI) patients in a multiethnic Asian population.

Methods

We evaluated 23,922 STEMI and 62,631 NSTEMI patients from a national multiethnic registry. Short-term cardiovascular and all-cause mortalities in SMuRF-less patients were compared to SMuRF-positive patients.

Results

The proportions of SMuRF-less STEMI but not of NSTEMI have increased over the years. In hospitals, all-cause and cardiovascular mortality and 1-year cardiovascular mortality were significantly higher in SMuRF-less STEMI after adjustment for age, creatinine, and hemoglobin. However, this difference did not remain after adjusting for anterior infarction, cardiopulmonary resuscitation (CPR), and Killip class. There were no differences in mortality in SMuRF-less NSTEMI. In contrast to Chinese and Malay patients, SMuRF-less patients of South Asian descent had a two-fold higher risk of in-hospital all-cause mortality even after adjusting for features of increased disease severity.

Conclusion

SMuRF-less patients had an increased risk of mortality with STEMI, suggesting that there may be unidentified nonstandard risk factors predisposing SMuRF-less patients to a worse prognosis. This group of patients may benefit from more intensive secondary prevention strategies to improve clinical outcomes.

Optimal glucose, HbA1c, glucose-HbA1c ratio and stress-hyperglycaemia ratio cut-off values for predicting 1-year mortality in diabetic and non-diabetic acute myocardial infarction patients

Background

Stress-induced hyperglycaemia at time of hospital admission has been linked to worse prognosis following acute myocardial infarction (AMI). In addition to glucose, other glucose-related indices, such as HbA1c, glucose-HbA1c ratio (GHR), and stress-hyperglycaemia ratio (SHR) are potential predictors of clinical outcomes following AMI. However, the optimal blood glucose, HbA1c, GHR, and SHR cut-off values for predicting adverse outcomes post-AMI are unknown. As such, we determined the optimal blood glucose, HbA1c, GHR, and SHR cut-off values for predicting 1-year all cause mortality in diabetic and non-diabetic ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) patients.

Methods

We undertook a national, registry-based study of patients with AMI from January 2008 to December 2015. We determined the optimal blood glucose, HbA1c, GHR, and SHR cut-off values using the Youden’s formula for 1-year all-cause mortality. We subsequently analyzed the sensitivity, specificity, positive and negative predictive values of the cut-off values in the diabetic and non-diabetic subgroups, stratified by the type of AMI.

Results

There were 5841 STEMI and 4105 NSTEMI in the study. In STEMI patients, glucose, GHR, and SHR were independent predictors of 1-year all-cause mortality [glucose: OR 2.19 (95% CI 1.74–2.76); GHR: OR 2.28 (95% CI 1.80–2.89); SHR: OR 2.20 (95% CI 1.73–2.79)]. However, in NSTEMI patients, glucose and HbA1c were independently associated with 1-year all-cause mortality [glucose: OR 1.38 (95% CI 1.01–1.90); HbA1c: OR 2.11 (95% CI 1.15–3.88)]. In diabetic STEMI patients, SHR performed the best in terms of area-under-the-curve (AUC) analysis (glucose: AUC 63.3%, 95% CI 59.5–67.2; GHR 68.8% 95% CI 64.8–72.8; SHR: AUC 69.3%, 95% CI 65.4–73.2). However, in non-diabetic STEMI patients, glucose, GHR, and SHR performed equally well (glucose: AUC 72.0%, 95% CI 67.7–76.3; GHR 71.9% 95% CI 67.7–76.2; SHR: AUC 71.7%, 95% CI 67.4–76.0). In NSTEMI patients, glucose performed better than HbA1c for both diabetic and non-diabetic patients in AUC analysis (For diabetic, glucose: AUC 52.8%, 95% CI 48.1–57.6; HbA1c: AUC 42.5%, 95% CI 37.6–47. For non-diabetic, glucose: AUC 62.0%, 95% CI 54.1–70.0; HbA1c: AUC 51.1%, 95% CI 43.3–58.9). The optimal cut-off values for glucose, GHR, and SHR in STEMI patients were 15.0 mmol/L, 2.11, and 1.68 for diabetic and 10.6 mmol/L, 1.72, and 1.51 for non-diabetic patients respectively. For NSTEMI patients, the optimal glucose values were 10.7 mmol/L for diabetic and 8.1 mmol/L for non-diabetic patients.

Conclusions

SHR was the most consistent independent predictor of 1-year all-cause mortality in both diabetic and non-diabetic STEMI, whereas glucose was the best predictor in NSTEMI patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01395-3.

Ca2+-dependent protein acyltransferase DHHC21 controls activation of CD4+ T cells

Despite the recognized significance of reversible protein lipidation (S-acylation) for T cell receptor signal transduction, the enzymatic control of this post-translational modification in T cells remains poorly understood. Here, we demonstrate that DHHC21 (also known as ZDHHC21), a member of the DHHC family of mammalian protein acyltransferases, mediates T cell receptor-induced S-acylation of proximal T cell signaling proteins. Using Zdhhc21dep mice, which express a functionally deficient version of DHHC21, we show that DHHC21 is a Ca2+/calmodulin-dependent enzyme critical for activation of naïve CD4+ T cells in response to T cell receptor stimulation. We find that disruption of the Ca2+/calmodulin-binding domain of DHHC21 does not affect thymic T cell development but prevents differentiation of peripheral CD4+ T cells into Th1, Th2 and Th17 effector T helper lineages. Our findings identify DHHC21 as an essential component of the T cell receptor signaling machinery and define a new role for protein acyltransferases in regulation of T cell-mediated immunity.

Fast-ion Dα spectroscopy diagnostic at KSTAR

A fast-ion Dα (FIDA) diagnostics system was installed for core and edge measurements on KSTAR. This system has two tangential FIDA arrays that cover both blue- and redshifted Dα lines (cold: 656.09 nm) in active views along the neutral beam 1 A centerline. The spectral band is 647-662.5 nm, and it covers the Doppler shift of the emission from the maximum energy of the neutral beam (100 keV). A curved filter strip with a motorized stage adequately prevents saturation of the electron multiplying charge-coupled device signal by the cold Dα line from the plasma edge. From comparisons of the measured spectra and FIDASIM modeling code, the FIDA spectra are well matched quantitatively. Moreover, the first measurements show that the FIDA radiance agrees with the neutron rate in the time trace during external heating and perturbation. In addition, responses are observed in the core FIDA radiance during the edge-localized mode cycle.

Association between smoking status and outcomes in myocardial infarction patients undergoing percutaneous coronary intervention

Smoking is one of the leading risk factors for cardiovascular diseases, including ischemic heart disease and hypertension. However, in acute myocardial infarction (AMI) patients, smoking has been associated with better clinical outcomes, a phenomenon termed the “smoker’s paradox.” Given the known detrimental effects of smoking on the cardiovascular system, it has been proposed that the beneficial effect of smoking on outcomes is due to age differences between smokers and non-smokers and is therefore a smoker’s pseudoparadox. The aim of this study was to evaluate the association between smoking status and clinical outcomes in ST-segment elevation (STEMI) and non-STEMI (NSTEMI) patients treated by percutaneous coronary intervention (PCI), using a national multi-ethnic Asian registry. In unadjusted analyses, current smokers had better clinical outcomes following STEMI and NSTEMI. However, after adjusting for age, the protective effect of smoking was lost, confirming a smoker’s pseudoparadox. Interestingly, although current smokers had increased risk for recurrent MI within 1 year after PCI in both STEMI and NSTEMI patients, there was no increase in mortality. In summary, we confirm the existence of a smoker’s pseudoparadox in a multi-ethnic Asian cohort of STEMI and NSTEMI patients and report increased risk of recurrent MI, but not mortality, in smokers.

MicroRNA-98 reduces nerve growth factor expression in nicotine-induced airway remodeling

Evolving evidence suggests that nicotine may contribute to impaired asthma control by stimulating expression of nerve growth factor (NGF), a neurotrophin associated with airway remodeling and airway hyperresponsiveness. We explored the hypothesis that nicotine increases NGF by reducing lung fibroblast (LF) microRNA-98 (miR-98) and PPARγ levels, thus promoting airway remodeling. Levels of NGF, miR-98, PPARγ, fibronectin 1 (FN1), endothelin-1 (EDN1, herein referred to as ET-1), and collagen (COL1A1 and COL3A1) were measured in human LFs isolated from smoking donors, in mouse primary LFs exposed to nicotine (50 μg/ml), and in whole lung homogenates from mice chronically exposed to nicotine (100 μg/ml) in the drinking water. In selected studies, these pathways were manipulated in LFs with miR-98 inhibitor (anti-miR-98), miR-98 overexpression (miR-98 mimic), or the PPARγ agonist rosiglitazone. Compared with unexposed controls, nicotine increased NGF, FN1, ET-1, COL1A1, and COL3A1 expression in human and mouse LFs and mouse lung homogenates. In contrast, nicotine reduced miR-98 levels in LFs in vitro and in lung homogenates in vivo Treatment with anti-miR-98 alone was sufficient to recapitulate increases in NGF, FN1, and ET-1, whereas treatment with a miR-98 mimic significantly suppressed luciferase expression in cells transfected with a luciferase reporter linked to the putative seed sequence in the NGF 3'UTR and also abrogated nicotine-induced increases in NGF, FN1, and ET-1 in LFs. Similarly, rosiglitazone increased miR-98 and reversed nicotine-induced increases in NGF, FN1, and ET-1. Taken together, these findings demonstrate that nicotine-induced increases in NGF and other markers of airway remodeling are negatively regulated by miR-98.

Mitochondrial Fission Mediated Cigarette Smoke-induced Pulmonary Endothelial Injury

Cigarette smoke (CS) exposure increases the risk for acute respiratory distress syndrome in humans and promotes alveolar-capillary barrier permeability and acute lung injury in animal models. However, the underlying mechanisms are not well understood. Mitochondrial fusion and fission are essential for mitochondrial homeostasis in health and disease. In this study, we hypothesized that CS caused endothelial injury via an imbalance of mitochondrial fusion and fission and resultant mitochondrial oxidative stress and dysfunction. We noted that CS altered mitochondrial morphology by shortening mitochondrial networks and causing perinuclear accumulation of damaged mitochondria in primary rat lung microvascular endothelial cells. We also found that CS increased mitochondrial fission likely by decreasing Drp1-S637 and increasing FIS1, Drp1-S616 phosphorylation, mitochondrial translocation, and tetramerization and reduced mitochondrial fusion likely by decreasing Mfn2 in lung microvascular endothelial cells and mouse lungs. CS also caused aberrant mitophagy, increased mitochondrial oxidative stress, and reduced mitochondrial respiration. An inhibitor of mitochondrial fission and a mitochondria-specific antioxidant prevented CS-induced increased endothelial barrier dysfunction and apoptosis. Our data suggest that excessive mitochondrial fission and resultant oxidative stress are essential mediators of CS-induced endothelial injury and that inhibition of mitochondrial fission and mitochondria-specific antioxidants may be useful therapeutic strategies for CS-induced endothelial injury and associated pulmonary diseases.

Downregulation of CFIm25 amplifies dermal fibrosis through alternative polyadenylation

This study implicates the key regulator of alternative polyadenylation, CFIm25 in dermal fibrosis and in systemic sclerosis (scleroderma) pathogenesis. CFIm25 downregulation promotes the expression of profibrotic factors, exaggerates bleomycin-induced skin fibrosis, while CFIm25 restoration attenuates skin fibrosis.

Systemic sclerosis (SSc; scleroderma) is a multisystem fibrotic disease. The mammalian cleavage factor I 25-kD subunit (CFIm25; encoded by NUDT21) is a key regulator of alternative polyadenylation, and its depletion causes predominantly 3′UTR shortening through loss of stimulation of distal polyadenylation sites. A shortened 3′UTR will often lack microRNA target sites, resulting in increased mRNA translation due to evasion of microRNA-mediated repression. Herein, we report that CFlm25 is downregulated in SSc skin, primary dermal fibroblasts, and two murine models of dermal fibrosis. Knockdown of CFIm25 in normal skin fibroblasts is sufficient to promote the 3′UTR shortening of key TGFβ-regulated fibrotic genes and enhance their protein expression. Moreover, several of these fibrotic transcripts show 3′UTR shortening in SSc skin. Finally, mice with CFIm25 deletion in fibroblasts show exaggerated skin fibrosis upon bleomycin treatment, and CFIm25 restoration attenuates bleomycin-induced skin fibrosis. Overall, our data link this novel RNA-processing mechanism to dermal fibrosis and SSc pathogenesis.

Demonstration of a ring-FEL as an EUV lithography tool

This paper presents the required structure and function of a ring-FEL as a radiation source for extreme ultraviolet radiation lithography (EUVL). A 100 m-long straight section that conducts an extremely low emittance beam from a fourth-generation storage ring can increase the average power at 13.5 nm wavelength to up to 1 kW without degrading the beam in the rest of the ring. Here, simulation results for a ring-FEL as a EUVL source are described.

Sustained adenosine exposure causes endothelial mitochondrial dysfunction via equilibrative nucleoside transporters

Adenosine is a potent signaling molecule that has paradoxical effects on lung diseases. We have previously demonstrated that sustained adenosine exposure by inhibition of adenosine degradation impairs lung endothelial barrier integrity and causes intrinsic apoptosis through equilibrative nucleoside transporter_1/2-mediated intracellular adenosine signaling. In this study, we further demonstrated that sustained adenosine exposure increased mitochondrial reactive oxygen species and reduced mitochondrial respiration via equilibrative nucleoside transporter_1/2, but not via adenosine receptor-mediated signaling. We have previously shown that sustained adenosine exposure activates p38 and c-Jun N-terminal kinases in mitochondria. Here, we show that activation of p38 and JNK partially contributed to sustained adenosine-induced mitochondrial reactive oxygen species production. We also found that sustained adenosine exposure promoted mitochondrial fission and increased mitophagy. Finally, mitochondria-targeted antioxidants prevented sustained adenosine exposure-induced mitochondrial fission and improved cell survival. Our results suggest that inhibition of equilibrative nucleoside transporter_1/2 and mitochondria-targeted antioxidants may be potential therapeutic approaches for lung diseases associated with sustained elevated adenosine.

A166 ANALYSIS OF SYMPTOMS, DIAGNOSTIC PATTERNS, AND CANADIAN PROVIDER PERSPECTIVE OF ACUTE HEPATIC PORPHYRIA

Background

Acute hepatic porphyria (AHP) is a family of rare genetic diseases, the most common being acute intermittent porphyria (AIP). AHP results from enzyme deficiencies involved in haem synthesis, leading to accumulation of neurotoxic haem intermediates, aminolaevulinic acid (ALA) and porphobilinogen (PBG), causing potentially life-threatening attacks and chronic symptoms. Patients afflicted by AHP often remain without a proper diagnosis for up to 15 years due to lack of awareness and testing. First-line diagnostic biochemical tests include measuring spot urinary ALA and PBG as both are elevated in the majority of AHP patients.

Aims

The study aimed to describe physicians experience diagnosing AHP and characterize patients globally, including Canada.

Methods

Physicians (n=175) who actively managed AHP patients (with and without recurrent attacks) in the preceding year were recruited from 9/2017–10/2017 to complete an online survey collecting information on demographics, familiarity with AHP and diagnostic tests, perspective on symptoms important to diagnosis, referral patterns, and treatment preferences. Physicians also completed a chart review of 546 patients and reported anonymized data on demographics, medical history, attacks, and symptoms. Data was analysed using descriptive statistics.

Results

Canadian physicians (n=15) practiced a mean of 19.7 years, 67% worked in community settings, and 53% were gastroenterologists. Symptoms informing AHP diagnosis included fatigue (93%), sensory loss (87%), mental confusion (87%), Abdominal pain (80%), red/dark urine (80%), vomiting (73%). AHP diagnostic tests considered informative for diagnosis included urinary ALA (87%) and PBG (80%); however, several non-specific tests were also commonly considered informative of AHP. Chronic symptoms reported included fatigue (75%), nausea/vomiting (70%), weakness (66%), pain (58%), anxiety (54%), diarrhea (41%), constipation (40%). Canadian physicians reported a mean of 58% AHP patients they manage being initially misdiagnosed. Global patients (n=546) were aged 40 years (mean), female (52%), with AIP (83%). Canadian patients (n=38) were aged 41 years (mean), female (61%), with AIP (78%). Patients had mean of 3.4 attacks and 1.6 hospitalizations in the past year.

Conclusions

This study highlights the challenges diagnosing AHP due to non-specificity of symptoms and limited understanding of diagnostic procedures. Due to the frequent presentation of gastrointestinal symptoms, AHP should be included in gastroenterologists’ differential diagnosis of patients presenting with non-specific abdominal pain. Among patients diagnosed with AHP, both acute attacks and chronic symptoms were reported, implicating both in the disease.

Funding Agencies

Alnylam Pharmaceuticals

P3466Cardiac output in end-stage liver disease increases with the severity of liver dysfunction

Background

End-stage liver disease is associated with significant systemic and haemodynamic alterations that affect cardiac function. Cirrhotic cardiomyopathy remains an ill-defined entity among cardiologists. Understanding the complex interplay between liver dysfunction and cardiac function can lead to a better understanding of the compensatory mechanisms of the heart in liver failure.

Purpose

To investigate whether severity of liver disease affects baseline cardiac output in a large contemporary cohort of patients undergoing liver transplant work-up.

Methods

Consecutive patients that underwent pre-liver transplant (LT) workup between 2010–2017 were included. All patients underwent a resting echocardiogram. Cardiac output (CO) was prospectively recorded at baseline by pulsed-wave Doppler examination of the left ventricular outflow tract from the apical window and systemic vascular resistance (SVR) was calculated as 80 x (mean arterial pressure (MAP)/CO). Severity of liver disease was characterized by the model of end-stage liver disease (MELD) and Child-Pugh scores.

Results

560 patients were included (mean age 57.5±7.7, 74.8% male). Mean MELD score was 19±7 and Child-Pugh Score was 9±3. There was an inverse linear relationship between the severity of liver disease by the MELD score and baseline SVR (rho 0.40, P<0.001). As SVR reduced, there was also a significant rise in baseline CO with a strong inverse correlation between the two variables (rho 0.86, p<0.001). There was a significant linear correlation between the severity of liver disease and baseline CO with both the scores (MELD Score rho 0.42, p<0.001; Child Pugh rho 0.44, p<0.001) (Figure).

Baseline CO in LT Patients by Severity

Conclusions

Baseline CO increased with the severity of liver dysfunction due to a reduced afterload. A higher resting CO may lead to patients encroaching on their cardiac reserve at rest. This provides a pathophysiological insight suggesting a limited role for beta-blockers, particularly in patients with advanced liver cirrhosis.

P3465Inducible left ventricular outflow tract obstruction is associated with a higher incidence of perioperative cardiac arrest in liver transplantation

Background

Inducible left ventricular outflow tract obstruction (LVOTO) is not infrequently encountered in liver transplant (LT) candidates undergoing cardiac workup. While the impact of LVOTO on adverse cardiovascular haemodynamics is well reported, it is unclear whether it predisposes to perioperative cardiovascular complications following LT.

Purpose

To investigate the effect of inducible left ventricular outflow tract obstruction on perioperative cardiovascular complications in a modern cohort of liver transplant patients.

Methods

Consecutive patients undergoing dobutamine stress echocardiography (DSE) were evaluated from a quaternary LT centre between 2010 and 2017. Inducible LVOTO was defined as LVOT gradient ≥36mmHg. Perioperative major adverse cardiovascular events (MACE) at 30 days and all-cause death were recorded from a prospectively maintained transplantation database and augmented by electronic medical record review.

Results

We evaluated 560 patients who underwent DSE as part of a workup for LT. Of these, 319 progressed to transplant. Inducible LVOTO was observed in 68 patients (21.3%). A higher baseline cardiac output (7.7 L/min vs 7.0 L/min, p=0.002) predicted for development of inducible LVOTO. Seventy-seven patients (4.1%) experienced a MACE including five deaths, 19 cases of heart failure, 11 cardiac arrests, 10 acute coronary syndromes and 46 cases of arrhythmias (VT/AF). Overall MACE occurred in 17/68 patients (25.0%) with LVOTO and 60/251 patients (23.9%) without LVOTO (p=0.85). However, there was a significantly increased risk of resuscitated perioperative cardiac arrest in patients with LVOTO (7.4% vs 2.4%, p=0.04). Patients with LVOTO also required significantly greater volumes of fluid intra-operatively (8.37L vs. 6.71L, p=0.043).

Cardiac Arrest in LT Patients with LVOTO

Conclusions

Inducible LVOTO is a frequent finding occurring in 21.3% of LT candidates. Despite higher intraoperative fluid resuscitation, LVOTO increased the risk of a perioperative cardiac arrest. Further studies are required to confirm these findings and to assess whether patients with LVOTO undergoing liver transplantation may benefit from heightened perioperative surveillance.

Transforming growth factor β1 alters the 3'-UTR of mRNA to promote lung fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic disease characterized by the pathological remodeling of air sacs as a result of excessive accumulation of extracellular matrix (ECM) proteins, but the mechanism governing the robust protein expression is poorly understood. Our recent findings demonstrate that alternative polyadenylation (APA) caused by NUDT21 reduction is important for the increased expression of fibrotic mediators and ECM proteins in lung fibroblasts by shortening the 3'-untranslated regions (3'-UTRs) of mRNAs and stabilizing their transcripts, therefore activating pathological signaling pathways. Despite the importance of NUDT21 reduction in the regulation of fibrosis, the underlying mechanisms for the depletion are unknown. We demonstrate here that NUDT21 is depleted by TGFβ1. We found that miR203, which is increased in IPF, was induced by TGFβ1 to target the NUDT21 3'-UTR, thus depleting NUDT21 in human and mouse lung fibroblasts. TGFβ1-mediated NUDT21 reduction was attenuated by the miR203 inhibitor antagomiR203 in fibroblasts. TGFβ1 transgenic mice revealed that TGFβ1 down-regulates NUDT21 in fibroblasts in vivo Furthermore, TGFβ1 promoted differential APA of fibrotic genes, including FGF14, RICTOR, TMOD2, and UCP5, in association with increased protein expression. This unique differential APA signature was also observed in IPF fibroblasts. Altogether, our results identified TGFβ1 as an APA regulator through NUDT21 depletion amplifying pulmonary fibrosis.

Comprehensive characterization of circular RNAs in ~ 1000 human cancer cell lines

BACKGROUND

Human cancer cell lines are fundamental models for cancer research and therapeutic strategy development. However, there is no characterization of circular RNAs (circRNAs) in a large number of cancer cell lines.

METHODS

Here, we apply four circRNA identification algorithms to heuristically characterize the expression landscape of circRNAs across ~ 1000 human cancer cell lines from CCLE polyA-enriched RNA-seq data. By using integrative analysis and experimental approaches, we explore the expression landscape, biogenesis, functional consequences, and drug response of circRNAs across different cancer lineages.

RESULTS

We revealed highly lineage-specific expression patterns of circRNAs, suggesting that circRNAs may be powerful diagnostic and/or prognostic markers in cancer treatment. We also identified key genes involved in circRNA biogenesis and confirmed that TGF-β signaling may promote biogenesis of circRNAs. Strikingly, we showed that clinically actionable genes are more likely to generate circRNAs, potentially due to the enrichment of RNA-binding protein (RBP) binding sites. Among these, circMYC can promote cell proliferation. We observed strong association between the expression of circRNAs and the response to drugs, especially those targeting chromatin histone acetylation. Finally, we developed a user-friendly data portal, CircRNAs in cancer cell lines (CircRiC, https://hanlab.uth.edu/cRic ), to benefit the biomedical research community.

CONCLUSIONS

Our study provides the characterization of circRNAs in cancer cell lines and explored the potential mechanism of circRNA biogenesis as well as its therapeutic implications. We also provide a data portal to facilitate the related biomedical researches.

Airflow limitation and survival after surgery for non-small cell lung cancer: Results from a systematic review and lung cancer screening trial (NLST-ACRIN sub-study)

OBJECTIVE

Lung cancer remains the single greatest cause of cancer mortality where surgery for early stage non-small cell lung cancer achieves the greatest survival. While there is growing optimism for better outcomes with screening using annual computed tomography, the impact of co-existing airflow limitation on survival remains unknown. To compare survival in non-small cell lung cancer patients undergoing surgery stratified according to the presence or absence of pre-surgery airflow limitation.

MATERIALS AND METHODS

We undertook a systematic literature search of non-screen lung cancer that encompassed studies reported between January 1946 and January 2017. Full-text articles were identified following eligibility scoring, with data extracted and analysed using a standardised analytical method (PRISMA). The results of this systematic review in non-screen lung cancers were compared to real-world results from a lung cancer screening cohort (N = 10,054), where outcomes following surgery could be compared after stratification according to pre-surgery airflow limitation.

RESULTS

In the systematic review, 6899 subjects were included from 10 studies; 7 were retrospective, 3 were prospective. Overall survival was 950 (44%) in 2144 people with COPD and 2597 (55%) from 4755 controls (unadjusted P value <0.001). However, the overall meta-analysed random effects odds ratio for overall survival (N = 10) and 5-year survival (N = 4) comparing those with and without COPD was 0.91 (95% CI = 0.84-1.00) and 0.99 (95% CI = 0.79-1.24) respectively. There were no signs of significant heterogeneity (I² = 19.1%, P = 0.27) nor publication bias as assessed by funnel plot and Egger's test (P = 0.19). In the lung cancer screening sub-study of 10,054 screening participants we found no difference in 5-year survival in those with and without airflow limitation (84% and 81% respectively, P = 0.64).

CONCLUSION

Survival after surgery for non-small cell lung cancer is comparable between those with and without spirometry evidence of airflow limitation. This finding was replicated in lung cancer diagnosed during screening.

Cleavage factor 25 deregulation contributes to pulmonary fibrosis through alternative polyadenylation

Idiopathic pulmonary fibrosis (IPF) is a chronic and deadly disease with a poor prognosis and few treatment options. Pathological remodeling of the extracellular matrix (ECM) by myofibroblasts is a key factor that drives disease pathogenesis, although the underlying mechanisms remain unknown. Alternative polyadenylation (APA) has recently been shown to play a major role in cellular responses to stress by driving the expression of fibrotic factors and ECMs through altering microRNA sensitivity, but a connection to IPF has not been established. Here, we demonstrate that CFIm25, a global regulator of APA, is down-regulated in the lungs of patients with IPF and mice with pulmonary fibrosis, with its expression selectively reduced in alpha-smooth muscle actin (α-SMA) positive fibroblasts. Following the knockdown of CFIm25 in normal human lung fibroblasts, we identified 808 genes with shortened 3'UTRs, including those involved in the transforming growth factor-β signaling pathway, the Wnt signaling pathway, and cancer pathways. The expression of key pro-fibrotic factors can be suppressed by CFIm25 overexpression in IPF fibroblasts. Finally, we demonstrate that deletion of CFIm25 in fibroblasts or myofibroblast precursors using either the Col1a1 or the Foxd1 promoter enhances pulmonary fibrosis after bleomycin exposure in mice. Taken together, our results identified CFIm25 down-regulation as a novel mechanism to elevate pro-fibrotic gene expression in pulmonary fibrosis.