Engineering a Smart Nanofluidic Sensor for High-Performance Peroxynitrite Sensing through a Spirocyclic Ring Open/Close Reaction Strategy

Peroxynitrite (ONOO^-) is an important reactive oxygen/nitrogen species that participates in a range of physiological and pathological processes by modulating ion flux through biological channels. Inspired by a ONOO^--regulated K⁺ channel in vivo, herein, we describe the construction of a smart ONOO^--driven nanosensor using a spirocyclic ring open/close reaction approach. The prepared nanosensor possessed a prominent ONOO^- selectivity and sensitivity and rapid response (∼90 s) owing to the specific reaction between ONOO^- and ligands on the nanosensor surface with a high ion rectification ratio (∼10) and ion gating ratio (∼4). Moreover, this nanosensor system also exhibits excellent stability and recyclability. Thus, these results will provide a new direction for the design of nanochannel-based sensors for future practical and biological applications.

Controllable structural tailoring for enhanced ∼2 µm emission in heavily Tm3+-doped germanate glasses

Heavily Tm³⁺-doped glass fibers are urgently desired for ∼2µm single-frequency fiber lasers and high-repetition-rate mode-locked fiber lasers. Here the structure of glass networks was tuned through controlling the numbers of non-bridging oxygens and bridging oxygens by adjusting the composition of the glasses, hence increasing the Tm³⁺ doping concentration of germanate glasses. The increased flexibility of the glass networks favors the distribution of Tm³⁺ ions to decrease fluorescence quenching, which was confirmed by the experimental and theoretical results. A heavily Tm³⁺ (9.8×10²⁰ions/cm³)-doped germanate glass was successfully fabricated without quenching by tuning the components of the glass. To the best of our knowledge, the Tm³⁺ ion doping concentration is the highest reported level in Tm³⁺-doped glasses and fibers. The results suggest that the heavily Tm³⁺-doped germanate glass is highly promising for fabricating ∼2µm glass fibers with high gain per unit length.

Lower plasma melatonin levels predict worse long-term survival in pulmonary arterial hypertension

Background

Exogenous melatonin has been reported to be beneficial in the treatment of pulmonary hypertension (PH) in animal models. Multiple mechanisms may be involved, with melatonin exerting anti-oxidant and anti-inflammatory effects, as well as inducing vasodilation and cardio-protection. However, endogenous levels of melatonin in treatment-naïve pulmonary arterial hypertension (PAH) patients and their clinical significance are still unknown.

Methods and results

Plasma levels of endogenous melatonin were measured by liquid chromatography-tandem mass spectrometry in treatment-naïve PAH patients (n=43) and healthy controls (n=111). Melatonin levels were higher in PAH patients when compared with controls (Median 118.9 [IQR 109.3–147.7] versus 108.0 [102.3–115.2] pM, P<0.001) (Figure 1A). The overall mortality was 26% (11/43) during a median long-term follow-up of 42 [IQR: 32–58] months. When PAH patients were stratified into 4 groups according to the quartiles of melatonin levels, the mortality from below 1st quartile to above 4th quartile was 55% (6/11), 10% (1/10), 0% (0/12), and 40% (4/10), respectively (Figure 1B). Kaplan-Meier analysis further showed that patients with melatonin levels below the 1st quartile (<109.3 pM) had a worse long-term survival than patients with melatonin levels above the 1st quartile (Mean survival times were 46 [95% CI: 30–65] versus 68 [58–77] months, Log-rank, p=0.026) (Figure 1C).

Conclusion

Endogenous melatonin levels were increased in treatment-naïve PAH patients, and lower levels of melatonin were associated with worse long-term survival in patient with PAH, however, whether exogenous melatonin supplements may be effective as a therapeutic strategy in human PAH remains to be established.

Figure 1

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): This work was supported by the China Scholarship Council (201606230252) as well as the Netherlands CardioVascular Research Initiative: an initiative with support of the Dutch Heart Foundation (CVON2014-11, RECONNECT), and German Center for Cardiovascular Research (DZHK81Z0600207). Instrumentation support was received from AB Sciex, ltd. for LC-MS/MS analyses performed in this study.

Different tryptophan-kynurenine metabolism profiles in human pulmonary arterial hypertension and animal models of pulmonary hypertension

Background

De novo NAD+ synthesis through the tryptophan-kynurenine (TK) metabolism was recognized as an important pathway in improving mitochondrial function and survival of injury or apoptotic cells, which are key processes involved in the pathogenesis of pulmonary arterial hypertension (PAH). Although abnormal TK metabolism has been reported in human PAH, the difference between human and animal models of pulmonary hypertension (PH) are currently unknown.

Objective

Determine and compare TK metabolism profiles in plasma from human PAH and 3 animal models of PH.

Methods

Human plasma was collected from treatment naïve patients with PAH (n=43) and healthy controls (n=111). Animal plasma was collected from 3 animal models of PH and corresponding controls, including monocrotaline (MCT) induced PH in rat (n=7, control n=6), Sugen + hypoxia (SuHx) induced PH in rat (n=5, control n=6), and pulmonary vein banding (PVB) induced PH in swine (n=7, control n=6). TK metabolites were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Results

TK metabolism was altered in the plasma from of PAH compared to healthy controls (Figure 1A). Lower tryptophan (0.8 fold vs Control, p<0.0001), maintained 3-hydroxyanthranilic acid, and higher kynurenine, 3-hydroxykynurenine, anthranilic acid, and quinolinic acid (1.5, 2.6, 2.0, 2.6 fold vs Control, respectively, p all<0.0001) were seen in the plasma from human PAH. In the rat SuHx-PH model, kynurenine (0.7 fold, p<0.01) and quinolinic acid (0.5 fold, p<0.001) were lower, while 3-hydroxyanthranilic acid (4.3 fold, p<0.001) was higher in PH compared to control (Figure 1B). However, the TK metabolism was unaltered in MCT-PH model in rat (Figure 1C), and PVB-PH model in swine (Figure 1D).

Conclusions

TK metabolism was altered in the plasma from human PAH. The TK metabolism profiles were different among 3 animal models of PH, but did not mimic the profile in human PAH. Further research is required to determine the mechanism(s) behind the abnormal TK metabolism in human PAH as well as whether these mechanisms relate to disease onset or progression.

Figure 1

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): This work was supported by the China Scholarship Council (201606230252) as well as the Netherlands CardioVascular Research Initiative: an initiative with support of the Dutch Heart Foundation (CVON2014-11, RECONNECT), and German Center for Cardiovascular Research (DZHK81Z0600207). Instrumentation support was received from AB Sciex, ltd. for LC-MS/MS analyses performed in this study.

Construction of a Smart Nanofluidic Sensor through a Redox Reaction Strategy for High-Performance Carbon Monoxide Sensing

Carbon monoxide (CO), an important gas signaling molecule, demonstrated various physiological and pathological functions by regulating the ion flux of biological channels. Herein, inspired by the CO-regulated K⁺ channel in vivo, we propose a smart CO-responsive nanosensor through the redox reaction strategy. Such nanosensor demonstrated an outstanding CO specificity and selectivity with high ion rectification (∼9) as well as excellent stability and recyclability. Therefore, these results will provide a new direction for the design of nanochannel-based sensors for future practical and biological applications.

[Clinicopathological features and prognosis of gastrointestinal stromal tumor with PDGFRA-D842V mutation]

Objective: Platelet-derived growth factor alpha (PDGFRA) mutations are respectively rare in gastrointestinal stromal tumors (GIST). Most GIST with PDGFRA exon 18 mutations including D842V mutation are highly resistant to imatinib. The treatment of GIST harboring PDGFRA primary drug-resistant mutation is a major challenge. This article aims to investigate clinicopathologic features of GIST with PDGFRA-D842V mutation and the efficacy of comprehensive treatment, providing a reference for clinical practice. Methods: A retrospective cohort study was conducted to collect the clinicopathological and follow-up data of patients with GIST harboring PDGFRA mutation who were diagnosed and treated in the GIST Clinic of Renji Hospital from January 2005 to May 2020. According to the mutation site, the enrolled patients were divided into D842V mutation group and non-D842V mutation group. The differences of clinicopathologic characteristics between the two groups were compared. Furthermore, overall survival and prognostic factors were analyzed. Results: A total of 71 patients with PDGFRA-mutant GIST were included in this study, including 47 cases of D842V mutation (66.2%) and 24 cases of non-D842V mutation (33.8%). There were 28 male patients and 19 female patients in D842V mutation group, with a median age of 60 (36-82) years. There were 16 male patients and 8 female patients in non-D842V mutation group, with a median age of 62 (30-81) years. There were no significant differences in age, gender, primary location, surgical procedure, tumor size, mitotic count, expression of CD117 and DOG1, Ki-67 proliferation index and modified NIH grade between the two groups (all P>0.05). The positive rate of CD34 was 89.4% (42/47) and 62.5% (15/24) in the D842V mutation group and the non-D842V mutation group, respectively, with a statistically significant difference (χ(2)=5.644, P=0.018). Among all the cases, 66 cases underwent R0 resection without preoperative treatment; two cases underwent emergency operation with R1 resection because of tumor rupture; 2 cases were not operated after the pathological and mutation types were confirmed by biopsy (one case received avapritinib treatment and obtain partial remission). One case was diagnosed as wild-type GIST per needle biopsy in another institute, and underwent R0 resection after preoperative imatinib treatment for 6 months. After surgery, 5 high-risk GIST patients with D842V mutation and 5 high-risk GIST patients with non-D842V mutation were treated with imatinib for more than one year. The median follow-up time was 37 (1-153) months. As of the last follow-up among the patients who received R0 resection, 4 patients with D842V mutation had relapse, of whom 1 was in the period of imatinib administration, and the 3-year relapse-free survival rate was 94.2%; none of the patients with non-D842V mutation had relapse. There was no statistically significant difference in relapse-free surivval between two groups (P=0.233). Univariate analysis revealed that mitotic count (P=0.002), Ki-67 proliferation index (P<0.001) and modified NIH grade (P=0.025) were the factors associated with relapse-free survival of patients with D842V mutation after R0 resection (all P<0.05). However, the above factros were not testified as independant prognostic facors in multivariate Cox analysis (all P<0.05). Conclusion: Clinicopathologic features and the efficacy of radical resection in patients with PDGFRA-D842V mutation are similar to those in patients with non-D842V mutation.

Diagnostic value of combined nucleic acid and antibody detection in suspected COVID-19 cases

OBJECTIVES

Nucleic acid testing is the gold standard method for the diagnosis of coronavirus disease 2019 (COVID-19); however, large numbers of false-negative results have been reported. In this study, nucleic acid detection and antibody detection (IgG and IgM) were combined to improve the testing accuracy of patients with suspected COVID-19.

STUDY DESIGN

The positive rate of nucleic acid detection and antibody detection (IgG and IgM) were compared in suspected COVID-19 patients.

METHODS

A total of 71 patients with suspected COVID-19 were selected to participate in this study, which included a retrospective analysis of clinical features, imaging examination, laboratory biochemical examination and nucleic acid detection and specific antibody (IgM and IgG) detection.

RESULTS

The majority of participants with suspected COVID-19 presented with fever (67.61%) and cough (54.93%), and the imaging results showed multiple small patches and ground-glass opacity in both lungs, with less common infiltration and consolidation opacity (23.94%). Routine blood tests were mostly normal (69.01%), although only a few patients had lymphopenia (4.23%) or leucopenia (12.68%). There was no statistical difference in the double-positive rate between nucleic acid detection (46.48%) and specific antibody (IgG and IgM) detection (42.25%) (P = 0.612), both of which were also poorly consistent with each other (kappa = 0.231). The positive rate of combined nucleic acid detection and antibody detection (63.38%) was significantly increased, compared with that of nucleic acid detection (46.48%) and that of specific antibody (IgG and IgM) detection (42.25%), and the differences were statistically significant (P = 0.043 and P = 0.012, respectively).

CONCLUSIONS

Nucleic acid detection and specific antibody (IgG and IgM) detection had similar positive rates, and their combination could improve the positive rate of COVID-19 detection, which is of great significance for diagnosis and epidemic control.

AB0727 WORK OUTCOMES AND ASSOCIATED FACTORS IN ANKYLOSING SPONDYLITIS PATIENTS IN CHINA

Background:

Poorer work productivity due to pain and functional impairment is commonly seen in ankylosing spondylitis (AS) patients, which may contribute to huge social economic burden. However, data about work outcomes and associated factors in Chinese AS patients were barely reported.

Objectives:

To assess work outcomes and identify factors associated with poor work productivity in patients with AS in China.

Methods:

A cross-sectional study was conducted in China. Adult patients (aged ≥ 18 years) fulfilled the 1984 New York modified criteria of AS were enrolled from rheumatology center from Jan 2017 to Aug 2017. All participants completed questionnaires about socio-demographic characteristics, disease characteristics, quality of life and the Work productivity and activity impairment questionnaire in AS (WPAI:SpA) to accesses the impact of chronic health conditions on job performance and productivity. Factors associated with work outcomes were evaluated.

Results:

A total of 91 patients with AS were included: 87.8% males, 78.02% employed, mean age and disease duration of 30 and 10 years respectively. The mean (SD) activity impairment of all patients was 48.57% (22.02%). For patients with employed work, mean (SD) absenteeism, presenteeism and work productivity loss were 10.22% (19.44%), 43.86% (22.48%) and 47.92% (25.81%) respectively. In multivariable analysis, activity impairment was associated with Bath Ankylosing Spondylitis Functional Index (BASFI) (P<0.01) and Ankylosing Spondylitis Quality of Life (ASQoL) (P<0.01). Absenteeism was associated with disease duration (P=0.03). Presenteeism was associated with disease duration (P=0.04), BASFI (P<0.01) and ASQoL (P<0.01). Work productivity loss was associated with BASFI (P<0.01) and ASQoL (P<0.01).

Conclusion:

Longer disease duration, reduced physical function and poorer quality of life are associated with reduced work productivity in Chinese AS patients.

References:

[1]Boonen A, van der Heijde D, Landewe R, Spoorenberg A, Schouten H, Rutten-van Molken M, et al. Work status and productivity costs due to ankylosing spondylitis: comparison of three European countries. Annals of the rheumatic diseases. 2002;61(5):429-37.

[2]Martindale J, Shukla R, Goodacre J. The impact of ankylosing spondylitis/axial spondyloarthritis on work productivity. Best Pract Res Clin Rheumatol. 2015;29(3):512-23.

[3]Castillo-Ortiz JD, Ramiro S, Landewe R, van der Heijde D, Dougados M, van den Bosch F, et al. Work Outcome in Patients With Ankylosing Spondylitis: Results From a 12-Year Followup of an International Study. Arthritis Care Res (Hoboken). 2016;68(4):544-52.

[4]Sag S, Nas K, Sag MS, Tekeoglu I, Kamanli A. Relationship of work disability between the disease activity, depression and quality of life in patients with ankylosing spondylitis. J Back Musculoskelet Rehabil. 2018;31(3):499-505.

[5]Goh Y, Kwan YH, Leung YY, Fong W, Cheung PP. A cross-sectional study on factors associated with poor work outcomes in patients with axial spondyloarthritis in Singapore. Int J Rheum Dis. 2019;22(11):2001-8.

Disclosure of Interests:

None declared

FRI0590 BIOMARKERS OF HEMODYNAMIC SEVERITY OF SYSTEMIC-SCLEROSIS ASSOCIATED PULMONARY ARTERIAL HYPERTENSION BY SERUM PROTEOME ANALYSIS

Objectives:

To investigate alterations in the serum proteome of patients with systemic sclerosis (SSc)-associated pulmonary hypertension (PAH), to identify proteins that correlated with hemodynamic severity and to determine their possible pathogenic role.

Methods:

Patients were included if they fulfilled the following criteria: diagnosis of limited cutaneous SSc, no extensive interstitial lung disease (ILD), and no treatment with PAH-specific therapy. Patients were classified as cases if they had a definitive diagnosis of PAH confirmed by right heart catheterization (RHC) and a serum sample collected on the same day as RHC. They were classified as controls if they had no sign suggestive of PAH on echocardiography.

Results:

In a first exploratory step, serum expression of 1129 proteins was assessed in 15 cases and 16 controls by a high-throughput proteomic assay (SOMAscan). We identified 53 proteins differentially expressed between the 2 groups. Among these 53 candidates, only 2 correlated significantly with pulmonary vascular resistance (PVR): chemerin (p=0.01,ρ=0.62) and SET nuclear proto-oncogen (SET) (p=0.01,ρ=0.62).

To validate these results, serum levels of chemerin and SET were measured by ELISA assay in 25 additional cases and 19 additional controls. Chemerin levels were confirmed to be significantly higher in cases (p=0.01) and correlated with PVR (p=0.01,ρ=0.46).

In a second step, to study the potential pathophysiological role of chemerin, we performed confocal immunofluorescence analyses on explanted lungs of healthy controls, SSc-ILD without PAH and SSc-PAH patients. Chemerin receptor, CMKLR1, was significantly increased on SSc-ILD and SSc-PAH pulmonary artery smooth muscle cells (PA-SMC).

We then tested the effect of chemerin on PA-SMC proliferation by stimulating PA-SMCs from idiopathic pulmonary arterial hypertension (iPAH) patients with serum from SSc patients with and without PH, in the presence or absence of a CMKLR1 inhibitor. PA-SMCs from iPAH were confirmed to have higher mRNA expression of CMKLR1 than controls (p=0.03). Serum from SSc-PH patients induced a significantly higher PA-SMC proliferation (p=0.005) than serum from controls. This difference was no longer significant (p=0.69) when adding the CMKLR1 inhibitor α–NETA.

Conclusion:

Chemerin is a surrogate biomarker for PVR in SSc-PAH. Increased chemerin and its receptor, CMKLR1, contribute to the SSc-PAH pathogenesis by inducing PA-SMC proliferation.

Acknowledgments:

None

Disclosure of Interests:

Sebastien SANGES: None declared, Lisa Rice: None declared, Ly Tu: None declared, Jean-Luc Cracowski Grant/research support from: JL Cracowski received grants from United Therapeutic, Bioprojet and Topadur, David Montani Grant/research support from: Dr. MONTANI reports grants and personal fees from Actelion, grants and personal fees from Bayer, personal fees from GSK, personal fees from Pfizer, personal fees from MSD, personal fees from Chiesi, outside the submitted work, Julio Mantero: None declared, Camille Ternynck: None declared, Guillemette Marot: None declared, Eric Hachlla: None declared, David Launay Grant/research support from: Dr. Launay reports personal fees from Actelion, grants and personal fees from Takeda, grants and personal fees from CSL Behring, outside the submitted work., Marc Humbert Grant/research support from: Dr. Humbert reports personal fees from Actelion, grants and personal fees from Bayer, grants and personal fees from GSK, personal fees from Merck, from United Therapeutics, personal fees from Acceleron, outside the submitted work., Christophe Guignabert: None declared, Robert Lafyatis Grant/research support from: RL holds research grants from Formation, Elpidera and Kiniksa., Consultant of: R.L. has served as a consultant for Bristol Myers Squibb, Boehringer-Mannheim, Merck, Magenta and Genentech/Roche,

[Application of imatinib plasma concentration monitoring in the whole process management of gastrointestinal stromal tumor patients]

Objective: To investigate the significance of monitoring imatinib mesylate (IM) plasma concentrations in patients with gastrointestinal stromal tumor (GIST). Methods: A retrospective descriptive study was carried out. Inclusion criteria: (1) patients with GIST confirmed by postoperative pathology or puncture pathology receiving maintenance therapy of IM; (2) administration of same dose of IM for at least 4 weeks (achieving steady - state plasma concentration). Patients who had severe organ dysfunction, received IM generics, or received IM simultaneously with other drugs significantly affecting IM pharmacokinetic were excluded. A total of 185 patients at the GIST Clinic of Renji Hospital, Shanghai Jiaotong University School of Medicine from August 2018 to May 2019 were enrolled, including 114 males (61.6%) and 71 females (38.4%) with a median age of 60 years old (range, 30-89 years), and 63 advanced cases. Patients receiving preoperative or postoperative adjuvant therapy were given IM 400 mg QD; patients with KIT exon 9 mutation or with disease progression during IM 400 mg QD treatment were given IM 600 mg QD. If the patient had adverse reactions such as myelosuppression during the medication, IM would be reduced or given BID per day. The peripheral venous blood was collected (22 to 24 hours after the last dose for patients who took IM QD and 2 hours before the first dose per day for those who took IM BID). IM plasma concentration was measured through high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). Correlation analysis between IM plasma concentration results and clinical data was performed using linear regression analysis. Results: A total of 241 stable blood samples of IM plasma concentration from 185 patients were finally collected. The IM plasma concentrations were significantly different between the doses of 300 mg/d and 400 mg/d [(942.4±433.5) μg/L vs. (1340.0±500.1) μg/L, t=6.317, P<0.001], and between 400 mg/d and 600 mg/d [(1340.0±500.1) μg/L vs. (2188.0±875.5) μg/L, t=3.557, P=0.004]. Among the blood samples of 57 patients receiving IM 300 mg/d, the IM plasma concentration of the advanced patients was significantly lower than that of the non-advanced patients [(795.6±225.8) μg/L vs. (992.2±484.4) μg/L, t=2.088, P=0.042]. Among the 137 blood samples of patients receiving IM 400 mg/d, the IM plasma concentration was higher in patients aged >60 years than those aged ≤60 years [(1461.0±595.3) μg/L vs. (1240.0±380.9) μg/L, t=2.528, P=0.013] and the IM plasma concentration of cases with diarrhea was significantly lower than that of those without diarrhea [(745.8±249.6) μg/L vs. (1382.0±486.9) μg/L, t=6.794, P<0.001]. Gender, primary location, surgical procedure, mutated gene, mutation type, or time of administration was associated with IM plasma concentration no matter in patients taking IM doses of 400 mg/d or 300 mg/d (all P>0.05). Regression analysis showed that body mass (P=0.004 and P=0.019), body mass index (P=0.016 and P=0.042), and body surface area (P=0.007 and P=0.028) were all negatively correlated with IM plasma concentrations in patients taking IM doses of 300 mg/d and 400 mg/d. Within the 137 patients who received a fixed oral dose of 400 mg/d IM, 17 patients received oral 200 mg BID, whose IM plasma drug concentration was not significantly different compared with that of 120 patients who received 400 mg IM QD [(1488.0±408.3) μg/L vs. (1319.0±509.7) μg/L, t=1.307, P=0.193]. Conclusions: Monitoring IM plasma concentration is significant throughout the whole process of management of GIST patients receiving IM treatment. In particular, regular monitoring IM plasma concentration and developing appropriate treatment strategies can bring better therapeutic benefits for patients with low doses, diarrhea, advanced condition and older age.

[Investigation and analysis of thyroid function of medical occupational population in a tertiary-A hospital in Nanjing]

Objective: To evaluate the effect of low-dose of ionizing radiation on thyroid function of medical occupational group with long-term exposure, furthermore, to analyze the relationship between the thyroid hormones and the risk factors, such as exposure length, department and comulative radiation dose. Ultimately, providing the scientific basis for setting the ionizing radiation protection standards. Methods: The population who engaged radiodiagnosis and radiotherapy in a tertiary-A hospital was set up as occupational exposure, and the administrative staffs in a company were considered as control. According to the inclusion and exclusion criteria, 161 medical professionals and 159 administrative staffs as the research object.We figured out the basic information and general condition of the groups by face-to-face questionnaire survey, calculated the annual comulative radiation dose through local center for disease control and prevention, By means of the thyroid hormone testing, we analyzed the thyroid hormone levels with different population, occupational exposure factors. Applying Epidata、Excel in data management. All the data was analyzed by statistical software package Stata12.0. Descriptive statistics, single factor analysis of variance and other statistical methods were used for data analysis. Test standard: α=0.05、P<0.05 statistical significant. Results: Age, sex and seniority were proportionality between exposure and control groups. The dosages of occupational population exposure to ionizing radiation were about 1/10 of national permit value, belonging to low-dose exposure. The T(3), FT(3) level of the exposure group was decreased than the control group (P<0.001). especially the FT(3) level has statitical discrepancy among groups with different exposure length (P<0.05). Conclusion: Long-term exposure to low-dose ionizing radiatiom can induce the thyroid damage of medical occupational population, which should be broader concerned.

[New insights in the pathogenesis of pulmonary arterial hypertension]

Pulmonary arterial hypertension (PAH) is a severe and incurable cardiopulmonary disorder. Research from the past 10 years illustrates the complex and multifactorial aspects of PAH pathophysiology. Furthermore, latest advances in the field have led to a better understanding of the key components underlying this inadequate accumulation of pulmonary vascular cells within the pulmonary arterial walls, leading to pulmonary vascular remodelling. Among the underlying molecular and cellular mechanisms, pulmonary endothelial dysfunction, alterations of the inter-cell communications within the pulmonary arterial walls as well as defects of the inflammatory component and the loss of BMPRII activity play critical roles in the pathogenesis of the disease.

[Effect of aspirin on breast cancer stem cells and stemness of breast cancer]

Objective: To explore the effect of aspirin on the stemness of breast cancer cells and apoptosis induction of breast cancer stem cells. Methods: The 4T1 cells cultured with stem cell culture medium were screened, and immunofluorescence technique, flow cytometry and tumor-forming experiment in vivo were applied to test stem cell characteristics of the tumor spheres. After dealt with aspirin, the apoptosis rate of 4T1 stem cells was analyzed by flow cytometry. The 4T1 cells were cultured in vitro and treated with aspirin, then flow cytometry analysis was used to detect the expression of aldehydedehy drogenase1 (ALDH1), and the expression of stemness genes was tested by Western blot . Then, after culturing the cells with medium containing basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), B27 and N2, the ability of sphere-forming was observed and recorded by microscopy. In vivo BALB/c mice inoculated with 4T1 stem cells were randomly divided into the control group, 10 mg/kg, 30 mg/kg and 100 mg/kg aspirin groups. After 10 days, the mice were dealt with aspirin or NS for 15 days, then the tumor growth was observed and recorded. Results: The ratio of ALDH1 positive cells was up to 78.55%, and 4T1 tumor sphere had a postive expression of ALDH1 and sex determining region Y-box 2 (SOX2). In vivo tumorigenesis abilities of tumor sphere with 1×10(2) 4T1 stem cells could be 75%, while the ratio of normal cells was zero. The ratio of Aspirin-induced apoptosis of 4T1 stem cells at early stage and and late stage increased from 0.36% to 21.61%, and from 4.21% to 21.38%, respectively. Flow cytometry and Western blot assay results indicated that aspirin could reduce the expression of ALDH1, SOX2, octamer-binding transcription factor 4 (OCT4) and NANOG in 4T1 cells. Sphere-forming experiments results showed that aspirin could inhibit sphere forming ability of breast cancer cells. In vivo, aspirin inhibited the growth of tumors with a dose-dependent manner. Conclusion: Aspirin could induce apoptosis of cancer stem cells and reduce stemness of breast cancer, and thus play a growth-inhibiting action on breast cancer.

[Effect of low-dose ionizing radiation exposure on thyroid function in a medical occupational population]

Objective: We evaluated the effect of low-dose of ionizing radiation on thyroid function of medical occupational group with long-term exposure; furthermore; we analyzed the relationship between the thyroid hormones and the risk factors; such as exposure length; department. Ultimately; providing the scientific basis for setting the ionizing radiation protection standards. Methods: The population who engaged radiodiagnosis and radiotherapy in a tertiary-A hospital were set up as occupational exposure; 724 medical professionals as the research object. We figured out the basic information and general condition of the groups by face-to-face questionnaire survey; By means of the thyroid hormone testing; we analyzed the thyroid hormone levels with different population; occupational exposure factors. Then; obtained the prevalence of thyroid nodules by the thyroid ultrasound. Besides; we used the logistic regression model to analyze the risk factors related to thyroid nodule. Applying Epidata、Excel in data management. All the data was analyzed by statistical software package Stata12.0. Descriptive statistics; single factor analysis of variance and other statistical methods were used for data analysis. Test standard: α=0.05、P<0.05 statistical significant. Results: 1. Based on the work experience; we divided the study population into four groups; such as 1-9; 10-19; 20-29; and>30 years. The difference of the TSH level among the four groups was statistically significant (P<0.05) . 2. The multiple logistic regression showed that sex and seniority were the independent risk factors for the abnormal rate of thyroid nodules. Conclusion: Long-term exposure to low-dose ionizing radiatiom could induce the thyroid damage of medical occupational population; which should be broader concerned.

The motility of esophageal sphincters during liquid and solid bolus swallows: a multicenter normative value study of high-resolution manometry in China

BACKGROUND

It is gradually accepted that solid bolus swallow needs to be added to the procedure of manometry. The motility differences in the upper esophageal sphincter (UES) and lower esophageal sphincter (LES) were not well described. Sierra Scientific Instruments solid-state high-resolution manometry (HRM) system, the most popular HRM system in China, lacks the Chinese normative values for both liquid and solid bolus swallow parameters.

METHODS

The esophageal HRM data of 88 healthy volunteers were analyzed. The parameters of both sphincters in resting stage were summarized and those during solid and liquid swallows were compared.

KEY RESULTS

Normative HRM values of sphincter parameters in solid and liquid bolus swallows in China were established. The UES residual pressure of solid bolus swallows was lower than that of liquid bolus (0.3±5.5 mm Hg vs 4.8±5.9 mm Hg, P=.000). The time parameters of UES relaxation between two types of bolus swallows were similar. In solid bolus swallows, the intrabolus pressure (IBP) (13.8±5.1 mm Hg vs 10.9±5.7 mm Hg, P=.000) and LES relaxation time (11.0±2.1 seconds vs 8.7±1.3 seconds, P=.000) were higher. The 4-second integrated relaxation pressure between both bolus swallows was similar.

CONCLUSIONS & INFERENCES

The function of the UES and LES between solid and liquid bolus swallows is different. Chinese HRM parameters are different from the Chicago Classification (http://www.chictr.org.cn, Number ChiCTR-EOC-15007147).

Magnetic Susceptibility from Quantitative Susceptibility Mapping Can Differentiate New Enhancing from Nonenhancing Multiple Sclerosis Lesions without Gadolinium Injection

BACKGROUND AND PURPOSE

Magnetic susceptibility values of multiple sclerosis lesions increase as they change from gadolinium-enhancing to nonenhancing. Can susceptibility values measured on quantitative susceptibility mapping without gadolinium injection be used to identify the status of lesion enhancement in surveillance MR imaging used to monitor patients with MS?

MATERIALS AND METHODS

In patients who had prior MR imaging and quantitative susceptibility mapping in a current MR imaging, new T2-weighted lesions were evaluated for enhancement on conventional T1-weighted imaging with gadolinium, and their susceptibility values were measured on quantitative susceptibility mapping. Receiver operating characteristic analysis was used to assess the diagnostic accuracy of using quantitative susceptibility mapping in distinguishing new gadolinium-enhancing from new nonenhancing lesions. A generalized estimating equation was used to assess differences in susceptibility values among lesion types.

RESULTS

In 54 patients, we identified 86 of 133 new lesions that were gadolinium-enhancing and had relative susceptibility values significantly lower than those of nonenhancing lesions (β = -17.2; 95% CI, -20.2 to -14.2; P < .0001). Using susceptibility values to discriminate enhancing from nonenhancing lesions, we performed receiver operating characteristic analysis and found that the area under the curve was 0.95 (95% CI, 0.92-0.99). Sensitivity was measured at 88.4%, and specificity, at 91.5%, with a cutoff value of 11.2 parts per billion for quantitative susceptibility mapping-measured susceptibility.

CONCLUSIONS

During routine MR imaging monitoring to detect new MS lesion activity, quantitative susceptibility mapping can be used without gadolinium injection for accurate identification of the BBB leakage status in new T2WI lesions.