Live-cell biosensors based on the fluorescence lifetime of environment-sensing dyes

In this work, we examine the use of environment-sensitive fluorescent dyes in fluorescence lifetime imaging microscopy (FLIM) biosensors. We screened merocyanine dyes to find an optimal combination of environment-induced lifetime changes, photostability, and brightness at wavelengths suitable for live-cell imaging. FLIM was used to monitor a biosensor reporting conformational changes of endogenous Cdc42 in living cells. The ability to quantify activity using phasor analysis of a single fluorophore (e.g., rather than ratio imaging) eliminated potential artifacts. We leveraged these properties to determine specific concentrations of activated Cdc42 across the cell.

Increased Risk of Developing Systemic Lupus Erythematosus and Rheumatoid Arthritis in Patients with Primary Sjögren's Syndrome-A Secondary Cohort Analysis of Nationwide, Population-Based Claims Data

BACKGROUND

This retrospective cohort study aimed to examine the risk of developing systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) in patients with primary Sjögren's syndrome (pSS) compared to controls using data from a nationwide health claims database.

METHODS

Four distinct cohorts of patients with newly diagnosed pSS were established using Taiwan's National Health Insurance Research Database. Cohorts I and II were created to evaluate the risk of developing SLE and RA, respectively. Cohorts III and IV were assembled similarly to Cohorts I and II but employed a stricter definition, based on catastrophic illness certificate (CIC) status, for identifying patients with pSS. Comparison cohorts of patients without pSS were formed by frequency matching for sex, 5-year age interval, and index year. Incident rate ratios (IRR) for SLE or RA development were determined using Poisson regression models.

RESULTS

Patients with pSS, selected from just outpatient visits or with additional CIC status showed a significantly higher risk of developing SLE or RA compared with the controls. When stratified by age group or sex, the risk of developing SLE was notably higher in the young age group (adjusted IRR 47.24, p = 0.002) and women (adjusted IRR 7.63, p = 0.003) among patients with pSS. In addition, both men and women with pSS, irrespective of age, showed a significantly elevated risk of developing RA.

CONCLUSIONS

Patients with pSS exhibited an elevated risk of developing SLE and RA. Rheumatologists should carefully monitor patients with pSS for potential SLE and RA development.

Increased frequency of hospital admissions with active systemic lupus erythematosus disease activity defined by two different disease activity indices: A cohort study

The objective of this cohort study was to evaluate the association between the frequency of hospital admissions and disease activity, as defined by two different disease activity measurements: the Systemic Lupus Erythematosus Disease Activity Score (SLE-DAS) and the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K), in adult patients with systemic lupus erythematosus (SLEs). Patients with SLE were recruited from the rheumatology outpatient department of a regional hospital in southern Taiwan. SLE-DAS and SLEDAI-2K were used to define SLE disease activity and the cause of hospital admissions was identified by a rheumatologist based on medical records. A generalized linear model (GLM) with gamma distribution and log-linked function was used to analyze variables associated with the frequency of admission. The mean frequency of hospitalization was 0.34 times per year for all-cause and 0.21 times per year for SLE-related admission. Multivariate GLM analysis showed that moderate/severe SLE disease activity defined by SLE-DAS was associated with an increased frequency of all-cause and SLE-related hospital admissions while adjusting for other covariates. Moderate/severe SLE disease activity defined by SLEDAI-2K was only significantly associated with an increased frequency of all-cause hospitalization. When steroid dosage was included in the model, moderate/severe SLE disease activity defined by the SLE-DAS remained significantly associated with SLE-related hospital admissions (p = 0.032). In conclusion, disease activity defined by the SLE-DAS, but not SLEDAI-2K was associated with an increased frequency of SLE-related hospitalization. Steroid dosage, a lower educational level, and smoking were associated with an increased frequency of hospital admissions, whereas underweight and alcohol use were associated with a decreased frequency of hospital admissions. Rheumatologists should promptly control SLE disease activity of their patients, provide them with adequate health education, and maintain steroid doses to as low as possible to reduce the risk of hospital admissions.

Increased dental visits in patients with rheumatoid arthritis: a secondary cohort analysis of population based claims data

OBJECTIVE

To study the utilization of dental care in patients with rheumatoid arthritis (RA) and compare the incidence of common dental disorders in patients with and without RA.

METHODS

This data used in this study was from the population-based Taiwan's National Health Insurance Research Database. We identified 1337 patients with newly diagnosed RA between January 2000 and December 2012. We also identified 13,370 individual without a diagnosis of RA using frequency matching on 5-year age intervals, sex, and index year. Patients with a diagnosis of primary Sjögren's syndrome were excluded. Dental disorders were identified using respective ICD-9-CM codes confirmed by dentists. The incidence and incidence rate ratio [IRR] of each dental disorders were calculated using Poisson regression.

RESULTS

Compared with the comparison cohort, the prevalence of dentist visits in the RA cohort were significantly higher (70.3% vs. 66.7%, p = 0.008) and the frequency of dentist visits in the RA cohort were also significantly higher (median 2.67 vs. 1.78 per year, p < 0.001). In addition, the incidence of visits for dental caries (adjusted IRR 1.16, p < 0.001), pulpitis (adjusted IRR 1.12, p = 0.044), gingivitis (adjusted IRR 1.13, p = 0.027), periodontitis (adjusted IRR 1.13, p = 0.004), and oral ulcer (adjusted IRR 1.24, p = 0.003) were higher in patients with RA.

CONCLUSIONS

An elevated prevalence and frequency of dental visits were associated with patients with RA. In addition, elevated incidence of dental disorders, including dental caries, pulpitis, gingivitis, periodontitis, and oral ulceration, were observed. Oral health should be accessed regularly in patients with RA.

Increased Risk of Common Orthopedic Surgeries for Patients with Rheumatic Diseases in Taiwan

Background and Objectives: Rheumatic diseases, including rheumatoid arthritis, ankylosing spondylitis, psoriasis, and systemic lupus erythematosus (SLE), are characterized by chronic arthritis or spondyloarthritis, which can lead to joint and spine destruction. Our previous studies showed that the risk of common orthopedic surgeries, including total knee replacement (TKR), total hip replacement (THR), or spine surgery, was increased in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE. The aim of this review was to summarize the risk of TKR, THR, cervical spine, and lumbar spine surgery on the basis of studies conducted using data from Taiwan’s National Health Insurance Research Database (NHIRD). Materials and Methods: The risk of TKR, THR, cervical spine surgery, and lumbar spine surgery in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE was summarized from the results of our previous studies and unpublished findings based on NHIRD data. Results: Patients with rheumatoid arthritis and psoriasis and men with ankylosing spondylitis showed an increased risk of TKR. Patients with rheumatoid arthritis, ankylosing spondylitis, and women with SLE showed an increased risk of receiving THR. Only patients with ankylosing spondylitis had an increased risk of cervical spine surgery, and patients with rheumatoid arthritis or ankylosing spondylitis showed an increased risk of lumbar spine surgery. Although the risk of THR, TKR, or spine surgery in these patients has declined in the era of biologics use, direct evidence for the effects of biologics agents is not yet available. Conclusions: There was an increased risk of common orthopedic surgery in patients with rheumatoid arthritis, ankylosing spondylitis, psoriasis, and SLE. Clinicians should be vigilant to reduce the increased risk of TKR and THR in young and middle-aged patients with rheumatoid arthritis, THR in young patients with ankylosing spondylitis, and young female patients with SLE, as well as cervical spine surgery in young patients with ankylosing spondylitis.

Patterns of Outpatient Phecodes Predating the Diagnosis of Systemic Lupus Erythematosus in Taiwanese Women

Shortening the time to diagnosis and initiating early treatment are imperative to improve outcomes in patients with systemic lupus erythematosus (SLE). The aim of this case-control study, based on the data from the Taiwan’s National Health Insurance Research Database (NHIRD), was to investigate the patterns of diagnoses of disease phenotypes in female patients with SLE up to eight years prior to its definitive diagnosis. The 547 cases were selected from the 2000–2012 NHIRD catastrophic illness datafile and frequency-matched with 2188 controls. The primary diagnosis based on the first ICD-9-CM code for each outpatient visit was converted to Phecodes. Separate regression models, based on least absolute shrinkage and selection operator (lasso) regularization, with seven different lag periods from 1–2 to 7–8 years, were conducted. Results showed that SLE was associated with 46 disease phenotypes in a lag period of 2–3 years, but fewer in other lag periods. A number of SLE-associated disease phenotypes, such as primary thrombocytopenia, thyroid diseases, Raynaud’s syndrome, renal disease, and several infectious diseases, occurred mainly in the first few years prior to SLE diagnosis. In conclusion, SLE should be suspected when the disease phenotypes identified in the present study occurred concomitantly.

Association of Clinical Manifestations of Systemic Lupus Erythematosus and Complementary Therapy Use in Taiwanese Female Patients: A Cross-Sectional Study

Background and Objectives: Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease that affects predominantly women in the childbearing years. Patients may seek complementary therapies to manage their health and to reduce symptoms. However, to our knowledge, no studies have explored the association between clinical manifestations of SLE and complementary therapies. Therefore, this study aimed to investigate the association of complementary therapies with common clinical manifestations in Taiwanese female patients with SLE. Materials and Methods: A cross-sectional study was conducted at a regional teaching hospital in southern Taiwan. Outpatients from the rheumatology clinic who met the inclusion criteria were consecutively recruited. Demographic data, clinical manifestations of SLE, and types of complementary therapy use were determined using paper-based questionnaire. Multiple logistic regression analyses were conducted to investigate the use of complementary therapies associated with clinical manifestations of SLE. Results: Of the 317 female patients with SLE, 60.9% were 40 years or older. The five SLE clinical manifestations with the highest prevalence were Raynaud’s phenomenon (61.2%), photosensitivity (50.2%), Sjögren’s syndrome (28.4%), arthralgia and arthritis (22.1%), and renal involvement (14.5%). Multiple logistic regression analyses revealed that Raynaud’s phenomenon was significantly associated with fitness walking or strolling (adjusted odds ratio [aOR] 1.77; p = 0.027) and fish oil supplements (aOR 3.55, p < 0.001). Photosensitivity was significantly and inversely associated with the use of probiotics (aOR 0.49; p = 0.019). Renal involvement was significantly associated with the use of probiotics (aOR 2.43; p = 0.026) and visit to the Chinese medicine department in a hospital (aOR 3.14, p = 0.026). Conclusions: We found that different clinical manifestations of SLE were associated with the use of different complementary therapies. Health care providers should have up-to-date knowledge of common complementary therapies and be ready to provide evidence-based advice to patients with SLE.

Risk of Spine Surgery in Patients with Rheumatoid Arthritis: A Secondary Cohort Analysis of a Nationwide, Population-Based Health Claim Database

Background and Objectives: To study the risk of spine surgery, including cervical and lumbar spine surgeries in patients with rheumatoid arthritis (RA) compared with those without a diagnosis of RA. Materials and Methods: This is a secondary data analysis using population-based health claim data. We identified newly diagnosed adult patients with RA between January 2000 and December 2012, according to the International Classification of Diseases, Ninth revision, clinical modification code 714.0 from Taiwan’s National Health Insurance Research Database. Using data frequency-matched by 10-year age intervals, sex and index year with the RA cohort at a ratio of 5:1, we assembled a comparison cohort. All patients were followed until the study outcomes occurred (overall spine surgery, cervical spine surgery, or lumbar spine surgery) or the end of follow-up. Adjusted incidence rate ratios (aIRR) were calculated using Poisson regression analysis with age group, socioeconomic status, geographical region, and osteoporosis included as potential confounders. Results: We identified 1287 patients with RA and 6435 patients without RA. The incidence of overall spine surgery (aIRR = 2.13, 95% confidence interval (CI) = 1.49–3.04) and lumbar spine surgery (aIRR = 2.14, 95% CI = 1.46–3.15) were all significantly higher in the RA cohort. Moreover, females over 45 years of age were particularly at risk for lumbar spine surgery. In RA patients, older age and the combination with the diagnosis of osteoporosis had an elevated risk for overall and lumbar spine surgery. Conclusion: Patients with RA had an increased risk of receiving spine surgery. Physicians should be vigilant for possible spinal problems in women and older patients with RA.

Factors associated with intimacy in female Taiwanese patients with systemic lupus erythematosus: a cross-sectional study

OBJECTIVE

The aim of this study was to investigate the association of demographic factors, clinical manifestations and disease activity of systemic lupus erythematosus (SLE) with intimate relationships in female patients with SLE.

DESIGN

This was a cross-sectional study based on questionnaires.

SETTING

This study was conducted at a regional teaching hospital in southern Taiwan from April to September 2019.

PARTICIPANTS

Adult patients with SLE recruited from the outpatient rheumatology clinics of the study hospital.

PRIMARY OUTCOME MEASURE

Disease-specific quality of life assessed using the Lupus Quality of Life questionnaire (LupusQoL).

RESULTS

A total of 243 female patients with SLE were enrolled. The results of the multiple linear regression analysis indicated that the independent factors associated with a higher score in the intimate relationships domain of the LupusQoL included the age group under 40 years (p=0.001), education level of college or above (p=0.005), being employed (p<0.001), a better self-reported health status (p=0.012) and a lower SLE-Disease Activity Score (SLE-DAS) score (p=0.010). In addition, the intimate relationships domain was significantly and independently associated physical health (p=0.001), fatigue (p=0.006) and burden to others (p=0.002) domains of the LupusQoL.

CONCLUSIONS

Physicians should be vigilant regarding the intimate relationships aspect of the health-related quality of life in female patients with SLE, especially in those who are older, unemployed, have a low educational level, poor self-reported health status, higher SLE-DAS, fatigue, and feeling of burden to others.

Increased risk of hospital admissions in patients with active systemic lupus erythematosus (SLE) classified according to two different SLE disease activity indices: a prospective cohort study

OBJECTIVES

The aim of this prospective cohort study was to investigate the risk of hospital admissions within one year in patients with active systemic lupus erythematosus (SLE), classified according to the Systemic Lupus Erythematosus Disease Activity Score (SLE-DAS) or the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K).

METHODS

This study was conducted in adult patients with SLE recruited from the rheumatology outpatient department in a regional hospital in southern Taiwan. SLE disease activity was measured with SLE-DAS and SLEDAI-2K. The computerised patient record database was accessed to identify patients' hospital admissions. Cox regression analyses were used to estimate the hazard ratio (HR) for all-cause and SLE-related hospital admission in SLE patients classified by SLE-DAS and SLEDAI-2K.

RESULTS

A total of 326 adult patients with SLE completed this study. All-cause and SLE-related hospital admissions within one year occurred in 17.5% and 12.6% of the patients, respectively. Results of the Cox regression analysis indicated that SLE patients with moderate/severe disease activity classified by the SLE-DAS (HR=2.43, p=0.005) but not moderate/severe disease activity classified by the SLEDAI-2K (HR=1.84, p=0.057) was significantly associated with the risk of SLE-related admissions. However, only moderate/severe disease activity classified by the SLE-DAS was significantly associated with the risk of all-cause admissions (HR=1.94, p=0.016). When steroid dosage was considered, only the steroid dosage was significantly associated all-cause and SLE-related admissions.

CONCLUSIONS

In this study, SLE disease activity classified by SLE-DAS was significantly associated with an increased risk for both all-cause and SLE-related hospital admissions. Rheumatologists should be vigilant for increased risk of hospital admissions in patients with moderate/high SLE disease activity as classified by SLE-DAS.

Factors associated with the use of complementary therapies in Taiwanese patients with systemic lupus erythematosus: a cross-sectional study

Background

This study aimed to investigate the prevalence of and the factors associated with the regular use of complementary therapies for Taiwanese patients with systemic lupus erythematosus (SLE).

Methods

In this cross-sectional study, 351 patients with SLE were consecutively recruited from a regional hospital in southern Taiwan from April to August 2019. Demographic and clinical information, including the use of different types of complementary therapies, was ascertained using a self-constructed questionnaire. Disease-specific quality of life was measured using the Lupus Quality of Life (LupusQoL) questionnaire. SLE disease activity was assessed using the rheumatologist-scored Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2 K). Factors associated with the regular use of complementary therapies were evaluated using multiple logistic regression analyses.

Results

Of the 351 patients with SLE, 90.3% were female, and 60.1% were ≥ 40 years of age. The prevalence of the regular use of any type of complementary therapy was 85.5%. The five most popular types of complementary therapy used were (1) fitness walking or strolling, (2) Buddhist prayer or attending temple, (3) vitamin consumption, (4) calcium supplementation, and (5) fish oil supplementation. Multiple logistic regression analyses revealed that the significant and independent factors associated with the regular use of complementary therapies in patients with SLE were age ≥ 40 years (adjusted odds ratio [aOR] 2.76, p = 0.013), nonoverweight or nonobesity (aOR 0.29, p = 0.004), engagement in vigorous exercise in the past year (aOR 4.62, p = 0.002), a lower SLEDAI-2 K score (aOR 0.90, p = 0.029), and a lower score in the physical health domain of the LupusQoL (aOR 0.57, p = 0.001).

Conclusions

A high prevalence of complementary therapy use in Taiwanese patients with SLE was observed. Rheumatologists should routinely ask patients about their use of supplements to minimize the risk of interaction with medical therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03416-w.

Association between clinical phenotypes of dermatomyositis and polymyositis with myositis-specific antibodies and overlap systemic autoimmune diseases

The aim of this study was to evaluate the association between clinical phenotypes of dermatomyositis (DM) and polymyositis (PM) with myositis-specific antibodies (MSAs), and overlap diagnosis of systemic autoimmune diseases.This cross-sectional study was conducted on 67 patients with DM and 27 patients with PM recruited from a regional hospital in southern Taiwan. Clinical phenotypes of DM and PM were assessed and MSAs were measured using a commercial line blot assay. The association of clinical phenotypes of DM and PM with MSAs and overlap diagnosis of systemic autoimmune diseases was performed using univariate and multiple logistic regression analyses.Clinically, patients with DM and PM and overlap diagnosis of systemic sclerosis were associated with a higher risk of interstitial lung diseases (ILDs) (odds ratio [OR] = 6.73; P = .048), Raynaud phenomenon (OR = 7.30; P = .034), and malignancy (OR = 350.77; P = .013). The risk of malignancy was also associated with older age (OR 1.31; P = .012), and male patients were associated with a higher risk of fever. For MSAs, anti-aminoacyl-tRNA synthetase antibodies were associated with ILD, antinuclear antibody were associated with a lower risk of arthritis, anti-transcription intermediary factor 1-gamma antibodies were associated with milder symptoms of muscle weakness, anti-Ku antibodies were associated with overlap diagnosis of systemic lupus erythematosus, and anti-Ro52 antibodies were associated with the development of Raynaud phenomenon and Sjögren syndrome.MSAs and overlap diagnosis of systemic sclerosis were significantly associated with clinical phenotypes of DM and PM. Physicians should be vigilant for malignancy in older DM and PM patients with overlap diagnosis of systeic sclerosis. The possibility of developing ILD in patients with overlap diagnosis of systemic sclerosis or serum positivity of anti-aminoacyl-tRNA synthetase antibodies should be considered.

Reactivation of hepatitis B virus infection in patients with rheumatoid arthritis receiving tofacitinib

OBJECTIVES

The aim of this study was to investigate hepatitis B virus (HBV) reactivation in patients with rheumatoid arthritis (RA) receiving tofacitinib.

METHOD

This was a retrospective study performed in a regional teaching hospital in southern Taiwan. During January 2017 and December 2020, patients with a clinician-confirmed diagnosis of RA using tofacitinib for at least 3 months were enrolled. Serum HBV DNA levels and serum alanine aminotransferase were followed up around every 3 to 6 months to assess HBV reactivation.

RESULTS

A total of 98 patients with RA were enrolled, and eight were hepatitis B surface antigen positive (HBsAg+) (8.1%), 64 were HBsAg-negative (HBsAg-)/hepatitis B core antibody positive (HBcAb+) (65.3%). In the HBsAg+ patients, two patients received antiviral prophylaxis, and none of them had HBV reactivation or hepatitis flare-up. The HBV reactivation rate was 33.3% (2/6) in the HBsAg+ RA patient without antiviral prophylaxis. Among the HBsAg-/HBcAb+ patients, the HBV reactivation rate was 3.1% (2/64). The incidence rate of HBV reactivation was 153.8 per 1000 person-years for overall HBsAg+ patients and 250 per 1000 person-years after excluding patients receiving antiviral prophylaxis. The incidence rate was 11.2 per 1000 person-years for HBsAg-/HBcAb+ patients with RA receiving tofacitinib.

CONCLUSION

Tofacitinib could induce HBV reactivation in both HBsAg+ and HBsAg-/HBcAb+ RA patients. HBsAg+ patients receiving tofacitinib have a high incidence rate of HBV reactivation, which could be prevented by antiviral prophylaxis. Although the risk of reactivation is low in HBsAg-/HBcAb+ patients, closely monitoring HBV DNA and alanine aminotransferase should be suggested.

A Comparison of the Correlation of Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) and Systemic Lupus Erythematosus Disease Activity Score (SLE-DAS) with Health-Related Quality of Life

Background and Aim: The aim of this study was to compare the correlation of a recently developed systemic lupus erythematosus disease activity score (SLE-DAS) with the SLE disease activity index 2000 (SLEDAI-2K) with the Lupus Quality of Life questionnaire (LupusQoL) in Taiwanese patients with SLE. Methods: A cross-sectional study was conducted in a regional teaching hospital in Taiwan from April to August 2019. Adult patients with a clinician-confirmed diagnosis of SLE based on the 1997 American College of Rheumatology revised criteria or the 2012 Systemic Lupus International Collaborating Clinics Classification Criteria were recruited. SLE disease activity was measured with both SLEDAI-2K and SLE-DAS. Disease-specific quality of life was assessed using the LupusQoL. Results: Of the 333 patients with SLE in this study, 90.4% were female and 40% were between the ages of 20 and 39 years. The median SLEDAI-2K score was 4.00 (interquartile range [IQR] 2.00–7.50) and the median SLE-DAS score was 2.08 (IQR 1.12–8.24) in our patients with SLE. After adjusting for sex and age intervals, both SLEDAI-2k and SLE-DAS were significantly and inversely associated with all eight domains of LupusQoL. The magnitudes of the mean absolute error, root mean square error, Akaike Information Criterion, Bayesian Information Criterion, and coefficient of determination were comparable between SLEDAI-2K and SLE-DAS. Conclusions: There were no clear differences in the use of SLE-DAS over SLEDAI-2K in assessing HRQoL in patients with SLE. We suggest that, in this aspect, both SLEDAI-2K and SLE-DAS are effective tools for measuring disease activity in patients with SLE.

Increased Incidence of Total Knee Replacement Surgery in Patients With Psoriasis: A Secondary Cohort Analysis of a Nationwide, Population-Based Health Claims Database

Patients with rheumatic diseases, such as rheumatoid arthritis, ankylosing spondylitis, and systemic lupus erythematosus, have increased risk of receiving total knee replacement surgery or total hip replacement surgery. We speculated that psoriasis could also attack the joints of the knees and hips, leading to an increased risk of receiving total knee replacement surgery or total hip replacement surgery. The aim of this study was to investigate the risk of total knee replacement or total hip replacement surgery in patients with psoriasis using a nationwide, population-based health claims database in Taiwan. Using the Taiwan's National Health Insurance Research Database, we identified 10,819 patients with psoriasis between 2000 and 2012. A comparison cohort consisting of five patients without psoriasis for each patient with psoriasis was assembled, based on frequency matching for sex, 10-year age interval, and index year. Both groups were followed until a diagnosis of the study outcomes (total knee replacement or total hip replacement surgery) or the end of the follow-up period. Incidence rate ratios (IRRs) for the outcome variables were calculated using multiple Poisson regression models. Female patients with psoriasis exhibited a significantly higher incidence of receiving total knee replacement surgery [adjusted IRR = 1.44, p = 0.014)]. Analyses stratified by age groups showed that the risk of receiving total knee replacement surgery was significantly higher older (adjusted IRR = 1.31, p = 0.047) patients with psoriasis. There were no significant differences in the risk of receiving total hip replacement surgery in patients with psoriasis compared with controls, either with or without stratification by sex or age groups. In conclusion, patients with psoriasis were associated with an increased risk of receiving total knee. Clinicians should be vigilant in assessing the presence of arthritis in these patients, and initiate strategies to delay or prevent the need for joint replacement.

Risk of dental malocclusion in children with upper respiratory tract disorders: A case-control study of a nationwide, population-based health claim database

OBJECTIVES

The aim of this study was to evaluate the association between different upper respiratory tract disorders and severe dental malocclusion in pediatric patients.

METHODS

Newly diagnosed patients (N = 773) with dental malocclusion aged 8-18 years and controls (N = 3865) were identified from the health claim records of the Longitudinal Health Insurance Database 2000 of Taiwan's National Health Insurance Research Database. Controls were frequency matched to the cases by sex, age group, and index year. Univariate and multiple logistic regression analyses were used to evaluate the association between severe dental malocclusion and six common upper respiratory tract disorders, including acute sinusitis, allergic rhinitis, chronic sinusitis, nasal septum deviation, nasal polyps, and hypertrophy of tonsil and adenoids.

RESULTS

The risk of severe dental malocclusion was significantly elevated in pediatric patients with three upper respiratory tract disorders, including acute sinusitis (adjusted odds ratio [aOR] = 1.66, 95% confidence interval [95% CI] 1.39-1.99), allergic rhinitis (aOR = 1.64, 95% CI 1.34-2.02), and chronic sinusitis (aOR = 2.01, 95% CI 1.27-3.19). When all the six upper respiratory tract disorders were simultaneously included in the multiple logistic regression analysis, acute sinusitis (aOR = 1.48, p < 0.001) and allergic rhinitis (aOR = 1.34, p < 0.010) were significantly and independently associated with an increased risk of severe dental malocclusion.

CONCLUSIONS

Findings from this nationwide, population-based case-control study indicated that acute sinusitis and allergic rhinitis were independently and significantly associated with an increased risk of severe dental malocclusion in pediatric patients. Pediatricians should remain vigilant for the risk of dental malocclusion in their patients with these disorders.

Modestly Elevated Serum Procalcitonin Levels in Patients with Rheumatoid Arthritis Free of Active Infection

Background and objectives: To investigate the serum procalcitonin (PCT) levels among patients with rheumatoid arthritis (RA) without active infection compared with healthy controls and to understand the relationship of PCT with RA disease activity, and treatment received by patients. Materials and Methods: Patients aged 20 years and above with clinician-confirmed diagnosis of RA and healthy volunteers were included during regular outpatient visits, and those with active infection symptoms and signs were excluded. RA disease activity was measured using the Disease Activity Score-28 for Rheumatoid Arthritis with erythrocyte sedimentation rate (DAS28-ESR). Medications received by the patients were also recorded. Results: A total of 623 patients with RA and 87 healthy subjects were recruited in this study. The mean PCT were significantly higher in patients with RA (6.90 ± 11.81 × 10⁻³ ng/mL) compared with healthy controls (1.70 ± 6.12 × 10⁻³ ng/mL) (p < 0.001) and the difference remained statistically significant after adjusting for age and sex. In addition, multiple linear regression analysis showed that a lower rank-transformed PCT serum level was significantly correlated with the use of biologics (p = 0.017) and a high DAS28-ESR score (p = 0.028) in patients with RA. Conclusion: Patients with RA have a significantly higher serum PCT levels compared with healthy controls. The use of biologics and an active RA disease activity were associated with a lower level of PCT in patients with RA. Further investigation is required to determine the optimal cutoff value of PCT among patients with RA and its association with disease activity and biologic usage.

Increased risk of developing dental diseases in patients with primary Sjögren's syndrome-A secondary cohort analysis of population-based claims data

Background

Although it is known that patients with primary Sjögren’s syndrome (pSS) have impaired dental conditions, incidence rates and incidence rate ratios of various dental diseases in these patients are not clear. The aim of this study was to investigate the frequency and prevalence of dental diseases in patients with pSS, and to evaluate the risk of common dental diseases in these patients.

Methods

A population-based retrospective cohort study was conducted using the data from the Taiwan's National Health Insurance Research Database. A total of 709 patients with newly diagnosed pSS between 2000 and 2012 were identified to form the pSS cohort. A comparison cohort of patients without pSS was assembled based on frequency matching for sex, 5-year age interval, and index year at a ratio of 10:1. All participants were followed until the end of the follow-up period or when the outcome of interest occurred. The incidence of dental caries, pulpitis, gingivitis, periodontitis, oral ulceration, and stomatitis were calculated using multiple Poisson regression models.

Results

A significantly higher prevalence (74.6% vs. 63.0%, P = 0.001) and frequency (median 5.37 vs. 1.45 per year, P < 0.001) dental visits were observed in patients with pSS compared with patients in the comparison cohort. The risk of dental caries (adjusted incidence rate ratio [aIRR] 1.64, P < 0.001), pulpitis (aIRR 1.42, P < 0.001), gingivitis (aIRR 1.43, P < 0.001), periodontitis (aIRR 1.44, P < 0.001), oral ulceration (aIRR 1.98, P < 0.001), and stomatitis (aIRR 2.06, P < 0.001) were significantly higher in patients with pSS.

Conclusions

In this nationwide, population-based cohort study, a higher prevalence and frequency of dental visits were found in patients with pSS. Patients with PSS had increased risk of six most common dental disorders, including dental caries, pulpitis, gingivitis, periodontitis, oral ulceration, and stomatitis. Rheumatologists should remain vigilant for the dental health of patients with pSS.

Infection control measures of a Taiwanese hospital to confront the COVID-19 pandemic

The World Health Organization announced the coronavirus disease 2019 (COVID-19) outbreak a pandemic on 12 March 2020. Although being in proximity to China, the original epicenter of the COVID-19 outbreak, Taiwan has maintained a low number of COVID-19 cases despite its close social ties and heavy traffic between Taiwan and China. Containment strategies executed by the Taiwanese government have attracted global attention. Similarly, in-hospital settings, high alertness and swift responses to the changing outbreak situation are necessary to ensure hospital staff members' safety so they can continue to save patients' lives. Herein, we present infection control measures that can be adopted in hospital settings that were executed in a Taiwanese hospital to confront the COVID-19 pandemic, including emergency preparedness and responses from the hospital administration, education, surveillance, patient flow arrangement, the partition of hospital zones, and the prevention of a systemic shutdown by using the "divided cabin, divided flow" strategy. The measures implemented by a Taiwan hospital during the COVID-19 pandemic may not be universally applicable in every hospital. Nonetheless, the presented infection control methods have been practically executed and can be referenced or modified to fit each hospital's unique condition.

Risks of ophthalmic disorders in patients with systemic lupus erythematosus - a secondary cohort analysis of population-based claims data

Background

Systemic lupus erythematosus (SLE) can directly affect various part of the ocular system, but there was no comprehensive analysis of ophthalmic disorders of patients with SLE using population-based data. The aim of this study was to investigate the frequency and prevalence of ophthalmic disorders for ophthalmologist visits in adult patients with SLE and to evaluate the risk of dry eye syndrome, cataracts, glaucoma, episcleritis and scleritis, and retinal vascular occlusion in these patients.

Methods

The Taiwan’s National Health Insurance Research Database was used to assemble a SLE cohort consisting of newly diagnosed SLE between 2000 and 2012. A comparison cohort was also sampled from the same database and it consisted of 10 patients without SLE for each patient with SLE, based on frequency matching for sex, five-year age interval, and index year. Both cohorts were followed until either the study outcomes have occurred or the end of the follow-up period.

Results

Patients with SLE (n = 521) exhibited a significantly higher prevalence (68.1% vs. 60.5%, P = 0.001) and frequency (median 5.51 vs. 1.71 per 10 years, P <  0.001) for outpatient ophthalmologist visits compared with patients without SLE. The risk of dry eye syndrome (adjusted incidence rate ratio [IRR] 4.45, P <  0.001), cataracts (adjusted IRR 3.18, P <  0.001), and glaucoma (adjusted IRR 2.23, P = 0.002) were significantly higher in patients with SLE. In addition, the risk of several SLE related ophthalmic disorders, including episcleritis and scleritis (adjusted IRR 6.11, P <  0.001) and retinal vascular occlusion (adjusted IRR 3.81, P = 0.023) were significantly higher in patients with SLE.

Conclusions

The increased risk of dry eye syndrome, cataracts, glaucoma, episcleritis and scleritis, and retinal vascular occlusion in patients with SLE deserves vigilance.

Predicting the Risk of Ischemic Stroke among Patients with Rheumatoid Arthritis Using a Simplified RA-CHADSV Score Based on the CHA2DS2-VASc Score

Background and Objectives: The aim of this retrospective cohort study was to develop a new score (RA-CHADSV) (rheumatoid arthritis - congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke/transient ischemic attack/thromboembolism, and vascular disease), modified from the CHA₂DS₂-VASc score (congestive heart failure, hypertension, age ≥75 years (doubled), diabetes mellitus, stroke/transient ischemic attack (doubled), vascular disease, age 65–74 years, and female), in predicting the risk of ischemic stroke in rheumatoid arthritis (RA) patients without atrial fibrillation (AF). Materials and Methods: Using the Taiwan’s National Health Insurance Research Database, 592 patients with RA diagnosed between 2000 and 2002 were identified and followed until first occurrence of ischemic stroke or the last available date in the database. Incidence rate ratios (IRR) of ischemic stroke for the CHA₂DS₂-VASc score were calculated using Poisson regression models. A new prediction score RA-CHADSV was developed using multiple logistic regression analysis with bootstrap validation. Results: The area under the receiver operating characteristic curve of the newly developed RA-CHADSV score and the CHA₂DS₂-VASc score were 0.73 (95% confidence interval (CI) 0.64–0.82) and 0.70 (95% CI 0.61–0.79), respectively. The RA-CHADSV score was significantly associated with a higher ischemic stroke incidence in the patients who scored ≥1 (adjusted IRR 7.39, p < 0.001). Conclusions: A simplified RA-CHADSV score, with comparable efficiency as the CHA₂DS₂-VASc score, but easier to use clinically was developed for predicting the risk of ischemic stroke among non-AF RA patients.

Green's functions for unsymmetric composite laminates with inclusions

It is known that the stretching and bending deformations will be coupled together for the unsymmetric composite laminates under in-plane force and/or out-of-plane bending moment. Although Green's functions for unsymmetric composite laminates with elliptical elastic inclusions have been obtained by using Stroh-like formalism around 10 years ago, due to the ignoring of inconsistent rigid body movements of matrix and inclusion, the existing solution may lead to displacement discontinuity across the interface between matrix and inclusion. Due to the multi-valued characteristics of complex logarithmic functions appeared in Green's functions, special attention should be made on the proper selection of branch cuts of mapped variables. To solve these problems, in this study, the existing Green's functions are corrected and a simple way to correctly evaluate the mapped complex variable logarithmic functions is suggested. Moreover, to apply the obtained solutions to boundary element method, we also derive the explicit closed-form solution for Green's function of deflection. Since the continuity conditions along the interface have been satisfied in Green's functions, no meshes are required along the interface, which will save a lot of computational time and the results are much more accurate than any other numerical methods.

An Investigation of the Side Effects, Patient Feedback, and Physiological Changes Associated with Direct-Acting Antiviral Therapy for Hepatitis C

Background: Hepatitis C virus (HCV) infection is one of the major causes of liver cirrhosis and hepatocellular carcinoma globally. The advent of direct-acting antivirals (DAAs) with high cure rates provides an opportunity to reduce the rising HCV disease burden. However, few studies have explored the side effects and physiological benefits of DAA therapy in rural areas. The aim of this study was to investigate the subjective reports of discomfort, patient feedback about the course of treatment, and physiological changes after DAA treatment in HCV patients. Methods: A descriptive, prospective, comparative cohort study was conducted from January to August 2019 in western coastal Yunlin County, Taiwan. Data regarding demographic characteristics, subjective discomfort levels, and physiological responses were collected through face to face interviews and from medical records by a cooperating hospital. Results: Six-hundred-and-twenty-three participants with an active HCV infection were identified; 555 (89.1%) had completed treatment, and sustained virologic response was achieved in 99.6% (n = 553). The mean age was 64.9 (standard deviation = 13.1) years, and 35% of patients experienced discomfort during DAA treatment, including fatigue, itching, and dizziness. After three months of treatment, physiological markers, including body weight (p < 0.001), waist circumference (p < 0.05), blood pressure (p < 0.001), alanine aminotransferase (p < 0.001), and aspartate aminotransferase (p < 0.001), had significantly improved. Almost all participants provided positive feedback about the treatment experience and reported manageable side effects. Conclusions: The findings showed that, in an endemic rural area, DAA treatment had a high cure rate and improved physiological markers with few discomforts. These results can be used to reduce the barriers HCV patients face in adopting new medications.

Risk of post-contrast acute kidney injury in emergency department patients with sepsis

INTRODUCTION

Although computed tomography (CT) is a useful tool for exploring occult infection in patients with sepsis in the emergency department, the potential nephrotoxicity of contrast media is a major concern. Our study aimed to investigate the association between use of contrast-enhanced CT and the risks of acute kidney injury and other adverse outcomes in patients with sepsis.

METHODS

In total, 587 patients with sepsis who underwent CT scan (enhanced CT group: 105, non-enhanced CT group: 482) from January 2012 to December 2016 at a tertiary referral centre were enrolled in this retrospective analysis, and propensity score matching was performed to minimise the selection bias. The length of stay, incidences of acute kidney injury and emergent dialysis, and short-term mortality were compared between the two groups.

RESULTS

Compared with patients in the non-enhanced CT group, patients in the contrast-enhanced CT group did not have increased risks of acute kidney injury (odds ratio [OR]=1.38, 95% confidence interval [CI]=0.55-3.43; P=0.489), emergent dialysis (OR=1.31, 95% CI=0.47-3.68; P=0.602), or short-term mortality (OR=0.90, 95% CI=0.48-1.69; P=0.751). In addition, there was no significant difference in the median length of hospital stay between survivors in the two groups (20 vs 19 days, P=0.742).

CONCLUSIONS

Intravenous contrast administration during CT scanning was not associated with prolonged length of hospital stay in patients with sepsis in an emergency setting. Moreover, the use of contrast-enhanced CT was not associated with increased risks of acute kidney injury, emergent dialysis, or short-term mortality.

Genetic toxicology in silico protocol

In silico toxicology (IST) approaches to rapidly assess chemical hazard, and usage of such methods is increasing in all applications but especially for regulatory submissions, such as for assessing chemicals under REACH as well as the ICH M7 guideline for drug impurities. There are a number of obstacles to performing an IST assessment, including uncertainty in how such an assessment and associated expert review should be performed or what is fit for purpose, as well as a lack of confidence that the results will be accepted by colleagues, collaborators and regulatory authorities. To address this, a project to develop a series of IST protocols for different hazard endpoints has been initiated and this paper describes the genetic toxicity in silico (GIST) protocol. The protocol outlines a hazard assessment framework including key effects/mechanisms and their relationships to endpoints such as gene mutation and clastogenicity. IST models and data are reviewed that support the assessment of these effects/mechanisms along with defined approaches for combining the information and evaluating the confidence in the assessment. This protocol has been developed through a consortium of toxicologists, computational scientists, and regulatory scientists across several industries to support the implementation and acceptance of in silico approaches.

Limited Chemical Structural Diversity Found to Modulate Thyroid Hormone Receptor in the Tox21 Chemical Library

BACKGROUND

Thyroid hormone receptors (TRs) are critical endocrine receptors that regulate a multitude of processes in adult and developing organisms, and thyroid hormone disruption is of high concern for neurodevelopmental and reproductive toxicities in particular. To date, only a small number of chemical classes have been identified as possible TR modulators, and the receptors appear highly selective with respect to the ligand structural diversity. Thus, the question of whether TRs are an important screening target for protection of human and wildlife health remains.

OBJECTIVE

Our goal was to evaluate the hypothesis that there is limited structural diversity among environmentally relevant chemicals capable of modulating TR activity via the collaborative interagency Tox21 project.

METHODS

We screened the Tox21 chemical library (8,305 unique structures) in a quantitative high-throughput, cell-based reporter gene assay for TR agonist or antagonist activity. Active compounds were further characterized using additional orthogonal assays, including mammalian one-hybrid assays, coactivator recruitment assays, and a high-throughput, fluorescent imaging, nuclear receptor translocation assay.

RESULTS

Known agonist reference chemicals were readily identified in the TR transactivation assay, but only a single novel, direct agonist was found, the pharmaceutical betamipron. Indirect activation of TR through activation of its heterodimer partner, the retinoid-X-receptor (RXR), was also readily detected by confirmation in an RXR agonist assay. Identifying antagonists with high confidence was a challenge with the presence of significant confounding cytotoxicity and other, non-TR-specific mechanisms common to the transactivation assays. Only three pharmaceuticals-mefenamic acid, diclazuril, and risarestat-were confirmed as antagonists.

DISCUSSION

The results support limited structural diversity for direct ligand effects on TR and imply that other potential target sites in the thyroid hormone axis should be a greater priority for bioactivity screening for thyroid axis disruptors. https://doi.org/10.1289/EHP5314.

Prevention of Postdental Procedure Bacteremia: A Network Meta-analysis

Postdental procedure bacteremia is common and troublesome. The comparative efficacy of multiple prophylactic interventions is unclear. We compared the efficacy of interventions for the prevention of postdental procedure bacteremia. We conducted a review of ClinicalKey, Cochrane CENTRAL, Embase, ProQuest, PubMed, ScienceDirect, Web of Science, and ClinicalTrials.gov from inception to December 4, 2018. Randomized controlled trials that evaluated prophylactic interventions for the prevention of postdental procedure bacteremia were eligible. The primary outcome was the incidence of postdental procedure bacteremia. A total of 24 trials were included with 2,147 participants. Our network meta-analysis demonstrated that intravenous administration of 1,000/200 mg of amoxicillin/clavulanate provided the least incidence of postdental procedure bacteremia among all the prophylactic interventions (odds ratio = 0.03, 95% CI = 0.00 to 0.63) as compared with the placebo/controls. Oral 3 g of amoxicillin had the least incidence of postdental procedure bacteremia among all oral or topical forms of prophylactic interventions (odds ratio = 0.10, 95% CI = 0.02 to 0.44) as compared with the placebo/controls. No serious adverse events, such as anaphylactic shock, mortality, and the development of antibiotic-resistant bacteria, were reported. None of the included subjects were of high risk of infectious endocarditis. Our network meta-analysis demonstrates that intravenous amoxicillin/clavulanate and oral amoxicillin might be the best prophylactic interventions in preventing postdental procedure bacteremia among all the oral/topical forms of interventions for the overall populations.

Risk of joint replacement surgery in Taiwanese female adults with systemic lupus erythematosus: a population-based cohort study

BACKGROUND

Female patients with systemic lupus erythematosus (SLE) are prone to have musculoskeletal system involvement, which could lead to joint damage. However, few studies have assessed the incidence of arthroplasty in female patients with SLE. The aim of this study was to investigate the risk of total hip replacement surgery and total knee replacement surgery in patients with SLE.

METHODS

We identified 577 female patients with newly diagnosed SLE between 2000 and 2012 using the Taiwan's National Health Insurance Research Database. A comparison cohort was constructed with female patients without SLE in a ratio of 5:1, based on frequency matching for 10-year age interval, and index year, for each patient with SLE. Both cohorts were followed until a diagnosis of the study outcomes or the end of the follow-up period.

RESULTS

Female patients with SLE showed a significantly higher incidence of receiving total hip replacement surgery (adjusted incidence rate ratio [aIRR] 6.47; P < 0.001), but not total knee replacement surgery (aIRR 1.81; P = 0.227). Moreover, age-group stratified analyses indicated a high incidence for receiving total hip replacement surgery among young female patients with SLE (aIRR 7.70; P = 0.001).

CONCLUSION

Young female patients with SLE had a high risk of receiving total hip replacement surgery, but not total knee replacement surgery.

Construction and application of (Q)SAR models to predict chemical-induced in vitro chromosome aberrations

In drug development, genetic toxicology studies are conducted using in vitro and in vivo assays to identify potential mutagenic and clastogenic effects, as outlined in the International Council for Harmonisation (ICH) S2 regulatory guideline. (Quantitative) structure-activity relationship ((Q)SAR) models that predict assay outcomes can be used as an early screen to prioritize pharmaceutical candidates, or later during product development to evaluate safety when experimental data are unavailable or inconclusive. In the current study, two commercial QSAR platforms were used to build models for in vitro chromosomal aberrations in Chinese hamster lung (CHL) and Chinese hamster ovary (CHO) cells. Cross-validated CHL model predictive performance showed sensitivity of 80 and 82%, and negative predictivity of 75 and 76% based on 875 training set compounds. For CHO, sensitivity of 61 and 67% and negative predictivity of 68 and 74% was achieved based on 817 training set compounds. The predictive performance of structural alerts in a commercial expert rule-based SAR software was also investigated and showed positive predictivity of 48-100% for selected alerts. Case studies examining incorrectly-predicted compounds, non-DNA-reactive clastogens, and recently-approved pharmaceuticals are presented, exploring how an investigational approach using similarity searching and expert knowledge can improve upon individual (Q)SAR predictions of the clastogenicity of drugs.

Abstract 3868: Development of a high-throughput screening co-culture angiogenesis assay system using hTERT immortalized primary cells

Angiogenesis is a multi-step physiological process which is involved in a large number of normal and disease state processes; In vitro angiogenesis models provide useful tools to study these processes, one of which is the analysis of tubule formation. Tubules formed in co-culture assays composed of both endothelial and stroma-producing cells were significantly more heterogeneous and more closely resembled capillaries than mono cell culture models utilizing only endothelial cells to generate tubules in an extracellular matrix. Current co-culture models using primary cells have donor variability and inconsistent results due to lot-to-lot variation. In this study, we established an in vitro co-culture model system consisting of an assay-ready mixture of an aortic endothelial cell line TeloHAEC-GFP and an hTERT immortalized adipose-derived mesenchymal stem cell line in a specially formulated medium containing VEGF supplement. Both cell lines were immortalized by hTERT alone and have been well-characterized; showing that the cells retain the most important characteristic of their primary counterparts. The new co-culture system forms functional tubular structures in less than 7 days, additionally, the hTERT-MSC cells which surround the tubular structures have undergone transformation indicated by elevated positive αSMA staining, indicating that the system has physiological relevance. Notably, our results showed the co-culture system has minimal lot-to-lot variation indicated by the treatment of three lots with the anti-cancer drug, ramucirumab. More importantly, the tubular formation efficiency is reduced or blocked by well-known anti-cancer drugs such as sunitinib and bevacizumab. We also tested four HIF-1 inhibitors identified in previous high-throughput screens and found that those compounds inhibited tubule formation in the co-culture system. These results suggest that the co-culture system can mimic the hypoxic environment in solid tumors. Previously the authors optimized the system for 384-well performance and here we report further optimization of the system into a 1536-well high-throughput format and a shortening of the assay time frame to 3 days. Using this format, we evaluated 2816 drugs from The National Center for Advancing Translational Sciences (NCATS) Pharmaceutical Collection (NPC), and 35 potent inhibitors (IC50 ≤1 μM) were identified. Moreover, many known angiogenesis inhibitors were identified, such as topotecan, docetaxel, and bortezomib. Several potential novel angiogenesis inhibitors were also identified from this study. Among the inhibitors, some compounds were proven to be involved in the hypoxia-inducible factor-1α and the nuclear factor-kappa B pathways. These results demonstrate that the co-culture model described in this report provides a consistent and robust in vitro system for antiangiogenic drug screening.

Citation Format: Chaozhong Zou, Shuaizhang LI, Chia-Wen Hsu, Menghang Xia, Metewo S. Enuameh. Development of a high-throughput screening co-culture angiogenesis assay system using hTERT immortalized primary cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3868.

In silico toxicology protocols

The present publication surveys several applications of in silico (i.e., computational) toxicology approaches across different industries and institutions. It highlights the need to develop standardized protocols when conducting toxicity-related predictions. This contribution articulates the information needed for protocols to support in silico predictions for major toxicological endpoints of concern (e.g., genetic toxicity, carcinogenicity, acute toxicity, reproductive toxicity, developmental toxicity) across several industries and regulatory bodies. Such novel in silico toxicology (IST) protocols, when fully developed and implemented, will ensure in silico toxicological assessments are performed and evaluated in a consistent, reproducible, and well-documented manner across industries and regulatory bodies to support wider uptake and acceptance of the approaches. The development of IST protocols is an initiative developed through a collaboration among an international consortium to reflect the state-of-the-art in in silico toxicology for hazard identification and characterization. A general outline for describing the development of such protocols is included and it is based on in silico predictions and/or available experimental data for a defined series of relevant toxicological effects or mechanisms. The publication presents a novel approach for determining the reliability of in silico predictions alongside experimental data. In addition, we discuss how to determine the level of confidence in the assessment based on the relevance and reliability of the information.

Gas hydrate dissociation off Svalbard induced by isostatic rebound rather than global warming

Methane seepage from the upper continental slopes of Western Svalbard has previously been attributed to gas hydrate dissociation induced by anthropogenic warming of ambient bottom waters. Here we show that sediment cores drilled off Prins Karls Foreland contain freshwater from dissociating hydrates. However, our modeling indicates that the observed pore water freshening began around 8 ka BP when the rate of isostatic uplift outpaced eustatic sea-level rise. The resultant local shallowing and lowering of hydrostatic pressure forced gas hydrate dissociation and dissolved chloride depletions consistent with our geochemical analysis. Hence, we propose that hydrate dissociation was triggered by postglacial isostatic rebound rather than anthropogenic warming. Furthermore, we show that methane fluxes from dissociating hydrates were considerably smaller than present methane seepage rates implying that gas hydrates were not a major source of methane to the oceans, but rather acted as a dynamic seal, regulating methane release from deep geological reservoirs.

Methane seepage from continental slopes has been attributed to gas hydrate dissociation induced by anthropogenic bottom water warming. Here, the authors show that hydrates dissociated before the Anthropocene when the isostatic rebound induced by deglaciation of the Arctic ice sheet outpaced eustatic sea-level rise.

Traumatic Dissections of Bilateral Internal carotid Artery with Aneurysms Formation

Carotid artery dissection is an unusual complication of blunt neck trauma with high mortality and severe neurological deficits. Traumatic bilateral dissections and dissecting aneurysms are extremely rare. A 17-year-old male presented to our emergency department with sudden onset of right hemiparesis and aphasia. Initial computed tomography scan of head and neck showed no remarkable finding. On the second day, a magnetic resonance angiography of head and neck demonstrated bilateral extracranial internal carotid artery dissections. The diagnosis of traumatic carotid artery dissection for emergency physicians is difficult because of the absence or delayed onset in symptomatology. Magnetic resonance angiography is currently considered as an appropriate initial diagnostic tool for carotid artery injury. In clinical practice, early diagnosis by keeping a high index of suspicions is required by emergency physicians.

Identification of Angiogenesis Inhibitors Using a Co-culture Cell Model in a High-Content and High-Throughput Screening Platform

Angiogenesis is an important hallmark of cancer, contributing to tumor formation and metastasis. In vitro angiogenesis models for analyzing tube formation serve as useful tools to study these processes. However, current in vitro co-culture models using primary cells have limitations in usefulness and consistency. Therefore, in the present study, an in vitro co-culture assay system was optimized in a 1536-well format for high-throughput screening using human telomerase reverse transcriptase (hTERT)–immortalized mesenchymal stem cells and aortic endothelial cells. The National Center for Advancing Translational Sciences (NCATS) Pharmaceutical Collection (NPC) library containing 2816 drugs was evaluated using the in vitro co-culture assay. From the screen, 35 potent inhibitors (IC₅₀ ≤1 µM) were identified, followed by 15 weaker inhibitors (IC₅₀ 1–50 µM). Moreover, many known angiogenesis inhibitors were identified, such as topotecan, docetaxel, and bortezomib. Several potential novel angiogenesis inhibitors were also identified from this study, including thimerosal and podofilox. Among the inhibitors, some compounds were proved to be involved in the hypoxia-inducible factor-1α (HIF-1α) and the nuclear factor-kappa B (NF-κB) pathways. The co-culture model developed by using hTERT-immortalized cell lines described in this report provides a consistent and robust in vitro system for antiangiogenic drug screening.

Abstract 792: Development of high-throughput cell-based co-culture angiogenesis assay system using hTERT immortalized cells

Angiogenesis is a multi-step physiological process which is involved in a large number of normal and disease state processes; In vitro angiogenesis models provide very useful tools to study these processes, one of which is the analysis of tubule formation. Tubules formed in co-culture assays were significantly more heterogeneous and more closely resembled capillaries than Matrigel® tubules. Current co-culture models using primary cells have donor variability, and inconsistent results due to lot to lot variation. In this study, we established an in vitro co-culture model system consisting of an assay ready mixture of an aortic endothelial cell line TeloHAEC-GFP (hTERT immortalized human aortic endothelial cell line) and a hTERT immortalized adipose-derived mesenchymal stem cell line (hTERT-MSCs) in a specially formulated medium containing VEGF supplement (Angio-Ready™ Angiogenesis Assay System). Both cell lines were immortalized by hTERT (human telomerase reverse transcriptase) alone and have been well-characterized showing that the cells retain the most important characteristic of their parental counterparts. The new co-culture system forms functional tubular structures in less than 7 days, and in addition, the hTERT-MSC cells which surround the tubular structures have undergone transformation indicated by elevated positive αSMA staining (a marker of smooth muscle cells), indicating that the system has physiological relevance. Notably, our results showed the co-culture system has minimal lot-to-lot variation indicated by the treatment of three lots with the anti-cancer drug, Ramucirumab (Cyramza®), which also targets the VEGF pathway. Next, we tested the new system with compounds that impact angiogenesis, results demonstrated that the angiogenesis system responds positively to elevated doses of VEGF and negatively to increasing concentrations of suramin; more importantly, the tubular formation efficiency is reduced or blocked by well-known anti-cancer drugs such as Sunitinib (SUTENT®) and Bevacizumab (Avastin®), both of which target the VEGF pathway. Finally, we used the Angio-Ready™ system validated 4 HIF-1(hypoxia inducible factors-1) inhibitors which have anti-angiogenic properties identified by high-throughput screening methods; data showed the results of the new system match with other screening methods including a system screening time as short as 3 days. Therefore, the co-culture model developed by using hTERT-immortalized cell lines described in this report provide a consistent and robust in vitro system for studying cardiovascular biology, drug screening and tissue engineering.

Citation Format: CHAOZHONG ZOU, Chia-Wen Hsu, Menghang Xia, Metewo S Enuameh. Development of high-throughput cell-based co-culture angiogenesis assay system using hTERT immortalized cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 792. doi:10.1158/1538-7445.AM2017-792

Identification of approved and investigational drugs that inhibit hypoxia-inducible factor-1 signaling

One of the requirements for tumor development is blood supply, most often driven by hypoxia-induced angiogenesis. Hypoxia induces the stabilization of hypoxia-inducible factor-1 alpha (HIF-1α), which induces expression of an angiogenic factor, vascular endothelial growth factor (VEGF). The purpose of this study is to validate a new screening platform combined with orthogonal assays to rapidly identify HIF-1 inhibitors and to evaluate the effectiveness of approved drugs on modulating HIF-1 signaling. We generated an endogenous HIF-1α-NanoLuc luciferase reporter allele in the human HCT116 colon cancer cell line using genome editing and screened a panel of small interfering RNAs (siRNAs) to 960 druggable targets and approximately 2,500 drugs on a quantitative high-throughput screening (qHTS) platform. Selected compounds were further investigated with secondary assays to confirm their anti-HIF activity and to study their mode of action. The qHTS assay identified over 300 drugs that inhibited HIF-1α-NanoLuc expression. The siRNA screening results supported the effectiveness of several target-specific inhibitors. Moreover, the identified HIF-1 inhibitors, such as mycophenolate mofetil, niclosamide, and trametinib, were able to suppress cancer cell proliferation and angiogenesis. Our study indicates that blocking the mitogen-activated protein kinase (MAPK) and phosphoinositol 3-kinase (PI3K) pathways effectively inhibits hypoxia-induced HIF-1α accumulation and HIF-1α transactivation and that proteasome inhibitors induce accumulation and decrease transcriptional activity of HIF-1α. These findings underline the importance of developing a battery of robust assay platforms and confirmation studies that focus on endogenous protein targets so that only relevant and reliable data will be taken into pre-clinical and clinical studies.

Differential modulation of FXR activity by chlorophacinone and ivermectin analogs

Chemicals that alter normal function of farnesoid X receptor (FXR) have been shown to affect the homeostasis of bile acids, glucose, and lipids. Several structural classes of environmental chemicals and drugs that modulated FXR transactivation were previously identified by quantitative high-throughput screening (qHTS) of the Tox21 10K chemical collection. In the present study, we validated the FXR antagonist activity of selected structural classes, including avermectin anthelmintics, dihydropyridine calcium channel blockers, 1,3-indandione rodenticides, and pyrethroid pesticides, using in vitro assay and quantitative structural-activity relationship (QSAR) analysis approaches. (Z)-Guggulsterone, chlorophacinone, ivermectin, and their analogs were profiled for their ability to alter CDCA-mediated FXR binding using a panel of 154 coregulator motifs and to induce or inhibit transactivation and coactivator recruitment activities of constitutive androstane receptor (CAR), liver X receptor alpha (LXRα), or pregnane X receptor (PXR). Our results showed that chlorophacinone and ivermectin had distinct modes of action (MOA) in modulating FXR-coregulator interactions and compound selectivity against the four aforementioned functionally-relevant nuclear receptors. These findings collectively provide mechanistic insights regarding compound activities against FXR and possible explanations for in vivo toxicological observations of chlorophacinone, ivermectin, and their analogs.

Abstract 356: Development and characterization of an in vitro co-culture angiogenesis assay system using hTERT immortalized cells for high throughput drug screening

Angiogenesis is a multi-step physiological process which is involved in a large number of normal and disease state processes; In vitro angiogenesis models provide very useful tools to study these processes, one of which is the analysis of tubule formation. Tubules formed in co-culture assays were significantly more heterogeneous and more closely resembled capillaries than Matrigel® tubules. Current co-culture models using primary cells have donor variability, and inconsistent results due to lot to lot variation. In this study, we established an in vitro co-culture model system consisting of an assay ready mixture of an aortic endothelial cell line TeloHAEC-GFP (hTERT immortalized human aortic endothelial cell line) and a hTERT immortalized adipose-derived mesenchymal stem cell line hTERT-MSC in a common specially formulated medium, the AngioReady™angiogenesis medium with VEGF supplement. Both cell lines were immortalized by hTERT (human telomerase reverse transcriptase) alone and have been well-characterized showing that the cells retain the most important characteristic of their parental counterparts. The new co-culture system forms functional tubular structures in less than 7 days, and in addition, the hTERT-MSC cells which surround the tubular structures have undergone transformation indicated by elevated positive αSMA staining (a marker of smooth muscle cells),indicating that the system has physiological relevance. Next, we tested the new system with compounds that impact angiogenesis, results demonstrated that the angiogenesis system responds positively to elevated doses of VEGF and negatively to increasing concentrations of suramin; more importantly, the tubular formation efficiency is reduced or blocked by well-known cancer drugs such as Sunitinib (SUTENT®) and Bevacizumab (Avastin®), both of which target the VEGF pathway. Notably, our results showed the co-culture system has minimal lot-to-lot variation indicated by the treatment of three lots of the Angio-ready™ system with the cancer drug, Ramucirumab (Cyramza®), which also targets the VEGF pathway. Finally, we used the Angio-ready™ system validated 4 HIF-1(hypoxia inducible factors-1) inhibitors which have anti-angiogenic properties identified by high-throughput screening methods; data showed the results of the new system match with other screening methods, what's more, Angio-ready™ system screening time can be as short as 3 days. Therefore, the co-culture models developed by using hTERT-immortalized cell lines described in this report provide a consistent and robust in vitro system for studying cardiovascular biology, drug screening and tissue engineering.

Citation Format: Chaozhong Zou, Chia-Wen Hsu, Chengkang Zhang, Isabela Oliva, Metewo S. Enuameh. Development and characterization of an in vitro co-culture angiogenesis assay system using hTERT immortalized cells for high throughput drug screening. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 356.

Efficient, designable, and broad-bandwidth optical extinction via aspect-ratio-tailored silver nanodisks

Subwavelength resonators, ranging from single atoms to metallic nanoparticles, typically exhibit a narrow-bandwidth response to optical excitations. We computationally design and experimentally synthesize tailored distributions of silver nanodisks to extinguish light over broad and varied frequency windows. We show that metallic nanodisks are 2-10x more efficient in absorbing and scattering light than common structures, and can approach fundamental limits to broadband scattering for subwavelength particles. We measure broadband extinction per volume that closely approaches theoretical predictions over three representative visible-range wavelength windows, confirming the high efficiency of nanodisks and demonstrating the collective power of computational design and experimental precision for developing new photonics technologies.

Pre-Dialysis Visits to a Nephrology Department and Major Cardiovascular Events in Patients Undergoing Dialysis

Background and Objectives

Pre-dialysis care by a nephrology out-patient department (OPD) may affect the outcomes of patients who ultimately undergo maintenance dialysis. This study examined the effect of pre-dialysis care by a nephrology OPD on the incidence of one-year major cardiovascular events after initiation of dialysis.

Design, Setting Participants, & Measurements

The study consisted of Taiwanese patients with chronic kidney disease (CKD) who commenced dialysis from 2006 to 2008. The number of nephrology OPD visits during the critical care period (within 6 months of initiation of dialysis) and the early care period (6–36 months before initiation of dialysis) were analyzed. The primary outcome measure was one-year major cardiovascular events.

Results

A total of 1191 CKD patients who initiated dialysis from 2006 to 2008 were included. Binary logistic regression showed that patients with ≧3 visits during the critical care period and those with ≧11 visits during the early care period had fewer composite major cardiovascular events than those with 0 visits. Patients with early referral are less likely to experience composite major cardiovascular events than those with late referral, with aOR 0.574 (95% CI = 0.43–0.77, P<0.001). Patients with both ≧3 visits during critical care period and ≧11 visits during early care period were less likely to experience composite major cardiovascular events (aOR = 0.25, 95% CI = 0.16–0.39, P < 0.001).

Conclusions

Patients with adequate pre-dialysis nephrology OPD visits, not just early referral, may had fewer one-year composite major cardiovascular events after initiation of dialysis. This information may be important to medical care providers and public health policy makers in their efforts to improve the well-being of CKD patients.

Ratiometric Imaging Using a Single Dye Enables Simultaneous Visualization of Rac1 and Cdc42 Activation

Biosensors that report endogenous protein activity in vivo can be based on environment-sensing fluorescent dyes. The dyes can be attached to reagents that bind selectively to a specific conformation of the targeted protein, such that binding leads to a fluorescence change. Dyes that are sufficiently bright for use at low, nonperturbing intracellular concentrations typically undergo changes in intensity rather than the shifts in excitation or emission maxima that would enable precise quantitation through ratiometric imaging. We report here mero199, an environment-sensing dye that undergoes a 33 nm solvent-dependent shift in excitation. The dye was used to generate a ratiometric biosensor of Cdc42 (CRIB199) without the need for additional fluorophores. CRIB199 was used in the same cell with a FRET sensor of Rac1 activation to simultaneously observe Cdc42 and Rac1 activity in cellular protrusions, indicating that Rac1 but not Cdc42 activity was reduced during tail retraction, and specific protrusions had reduced Cdc42 activity. A novel program (EdgeProps) used to correlate localized activation with cell edge dynamics indicated that Rac1 was specifically reduced during retraction.

Identification of HDAC Inhibitors Using a Cell-Based HDAC I/II Assay

Histone deacetylases (HDACs) are a class of epigenetic enzymes that regulate gene expression by histone deacetylation. Altered HDAC function has been linked to cancer and neurodegenerative diseases, making HDACs popular therapeutic targets. In this study, we describe a screening approach for identification of compounds that inhibit endogenous class I and II HDACs. A homogeneous, luminogenic HDAC I/II assay was optimized in a 1536-well plate format in several human cancer cell lines, including HCT116 and human neural stem cells. The assay confirmed 37 known HDAC inhibitors from two libraries of known epigenetics-active compounds. Using the assay, we identified a group of potential HDAC inhibitors by screening the National Center for Advancing Translational Sciences (NCATS) Pharmaceutical Collection of 2527 small-molecule drugs. The selected compounds showed similar HDAC I/II inhibitory potency and efficacy values in both HCT116 and neural stem cells. Several previously unidentified HDAC inhibitors were further evaluated and profiled for their selectivity against a panel of 10 HDAC I/II isoforms using fluorogenic HDAC biochemical assays. In summary, our results show that several novel HDAC inhibitors, including nafamostat and piceatannol, have been identified using the HDAC I/II cell-based assay, and multiple cell types have been validated for high-throughput screening of large chemical libraries.

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: focus on the cancer hallmark of tumor angiogenesis

One of the important 'hallmarks' of cancer is angiogenesis, which is the process of formation of new blood vessels that are necessary for tumor expansion, invasion and metastasis. Under normal physiological conditions, angiogenesis is well balanced and controlled by endogenous proangiogenic factors and antiangiogenic factors. However, factors produced by cancer cells, cancer stem cells and other cell types in the tumor stroma can disrupt the balance so that the tumor microenvironment favors tumor angiogenesis. These factors include vascular endothelial growth factor, endothelial tissue factor and other membrane bound receptors that mediate multiple intracellular signaling pathways that contribute to tumor angiogenesis. Though environmental exposures to certain chemicals have been found to initiate and promote tumor development, the role of these exposures (particularly to low doses of multiple substances), is largely unknown in relation to tumor angiogenesis. This review summarizes the evidence of the role of environmental chemical bioactivity and exposure in tumor angiogenesis and carcinogenesis. We identify a number of ubiquitous (prototypical) chemicals with disruptive potential that may warrant further investigation given their selectivity for high-throughput screening assay targets associated with proangiogenic pathways. We also consider the cross-hallmark relationships of a number of important angiogenic pathway targets with other cancer hallmarks and we make recommendations for future research. Understanding of the role of low-dose exposure of chemicals with disruptive potential could help us refine our approach to cancer risk assessment, and may ultimately aid in preventing cancer by reducing or eliminating exposures to synergistic mixtures of chemicals with carcinogenic potential.

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead

Low-dose exposures to common environmental chemicals that are deemed safe individually may be combining to instigate carcinogenesis, thereby contributing to the incidence of cancer. This risk may be overlooked by current regulatory practices and needs to be vigorously investigated.

Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety ‘Mode of Action’ framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology.

Patients with knee osteoarthritis undergoing total knee arthroplasty have a lower risk of subsequent severe cardiovascular events: propensity score and instrumental variable analysis

Objective

This population-based study investigated the subsequent cardiovascular risk of patients with knee osteoarthritis underwent total knee arthroplasty in Taiwan.

Materials and methods

This was a population-based follow-up study of 22931 patients diagnosed with knee osteoarthritis between 2008 and 2011. Each patient was followed for 3 years or until death. Treatment was dichotomized into conservative treatment and TKA. The association between TKA and cardiovascular disease (CVD) events was analyzed using propensity score analysis and instrumental variable analysis and two-stage least-squares regression model.

Results

Patients with knee osteoarthritis who underwent TKA had a lower 3-year cumulative risk of stroke and acute myocardial infarction (AMI). After adjusting for measured risk and confounding factors, propensity score showed a 0.56 fold (adjusted OR = 0.56; 95% CI, 0.51–0.61; p<0.001) risk for CVD in those with TKA. Use of instrumental variable analysis for adjusting measured and unmeasured factors and two-stage least squares regression model revealed that the average treatment effect of TKA was statistically associated with a decreased 7% risk of CVD events (95% CI, 0.2%–13.6%).

Conclusion

Our study revealed that patients with knee osteoarthritis who underwent TKA had a lower risk of suffering from a future severe cardiovascular event. This benefit may be attributed to an improvement in physical activity, reduction of psychosocial stress, and/or a decreased use of NSAIDs as a result of having undergone TKA.