Efficacy evaluation of Mongolian medical warm acupuncture for sciatica caused by lumbar disc herniation: a randomized, controlled, single-blind clinical trial

OBJECTIVE

This study aimed to evaluate the short-term and long-term efficacy of Mongolian medical warm acupuncture for sciatica caused by lumbar disc herniation (LDH).

PATIENTS AND METHODS

The patients diagnosed with sciatica caused by LDH were randomly divided into the warm acupuncture of the Mongolian medicine group (n = 42, warm acupuncture treatment), the sham acupuncture group (n = 38, sham acupuncture using blunt-tipped needles) and the conventional drug group (n = 40, ibuprofen sustained release capsule). All patients were treated for 4 weeks and followed up for 8 weeks. The visual analog scale for leg pain (VAS-LP), Mongolian medicine indicators (efficacy indicators), VAS for waist pain (VAS-WP) and the Mos 36-item short form health survey (SF-36) score were analyzed at baseline, after two-week treatment, after four-week treatment, at four-week follow-up and at eight-week follow-up.

RESULTS

Warm acupuncture treatment significantly decreased the VAS-LP and VAS-WP scores of patients at treatment and follow-up (p < 0.05), and pain was improved compared to the conventional drug group and sham acupuncture group. The total effective rate was markedly higher in the warm acupuncture of the Mongolian medicine group compared with the conventional drug group at 8-week follow-up (p < 0.05), but sham acupuncture treatment resulted in no evident improvement in the Mongolian medicine indicators. Additionally, at treatment and follow-up, warm acupuncture of the Mongolian medicine group showed a significant increase in the physical function, physical role, body pain, and emotional and mental health role scores of the SF-36 survey compared with the sham acupuncture groups.

CONCLUSIONS

Mongolian medical warm acupuncture effectively relieves leg and waist pain and improves the total therapeutic effect and the quality of daily life for patients with sciatica caused by LDH, with significant long-term efficacy. Our study provides a basis for warm acupuncture in the treatment of sciatica caused by LDH. Chinese Clinical Trial Registry ID: ChiCTR- INR-15007413.

Multiplex Bioanalytical Methods for Comprehensive Characterization and Quantification of the Unique Complementarity-Determining-Region Deamidation of MEDI7247, an Anti-ASCT2 Pyrrolobenzodiazepine Antibody-Drug Conjugate

Deamidation, a common post-translational modification, may impact multiple physiochemical properties of a therapeutic protein. MEDI7247, a pyrrolobenzodiazepine (PBD) antibody-drug conjugate (ADC), contains a unique deamidation site, N102, located within the complementarity-determining region (CDR), impacting the affinity of MEDI7247 to its target. Therefore, it was necessary to monitor MEDI7247 deamidation status in vivo. Due to the low dose, a sensitive absolute quantification method using immunocapture coupled with liquid chromatography-tandem mass spectrometry (LBA-LC-MS/MS) was developed and qualified. We characterized the isomerization via Electron-Activated Dissociation (EAD), revealing that deamidation resulted in iso-aspartic acid. The absolute quantification of deamidation requires careful assay optimization in order not to perturb the balance of the deamidated and nondeamidated forms. Moreover, the selection of capture reagents essential for the correct quantitative assessment of deamidation was evaluated. The final assay was qualified with 50 ng/mL LLOQ for ADC for total and nondeamidated antibody quantification, with qualitative monitoring of the deamidated antibody. The impact of deamidation on the pharmacokinetic characteristics of MEDI7247 from clinical trial NCT03106428 was analyzed, revealing a gradual reduction in the nondeamidated form of MEDI7247 in vivo. Careful quantitative biotransformation analyses of complex biotherapeutic conjugates help us understand changes in product PTMs after administration, thus providing a more complete view of in vivo pharmacology.

Multiplex Hybrid Antigen-Capture LC-MRM Quantification in Sera and Nasal Lining Fluid of AZD7442, a SARS-CoV-2-Targeting Antibody Combination

AZD7442 (tixagevimab [AZD8895]/cilgavimab [AZD1061]) is a monoclonal antibody (mAb) combination in development for the prevention and treatment of coronavirus disease 2019. Traditionally, bioanalysis of mAbs is performed using ligand binding assays (LBAs), which offer sensitivity, robustness, and ease of implementation. However, LBAs frequently require generation of critical reagents that typically take several months. Instead, we developed a highly sensitive (5 ng/mL limit of quantification) method using a hybrid LBA-liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) approach for quantification of the two codosed antibodies in serum and nasal lining fluid (NLF), a rare matrix. The method was optimized by careful selection of multiple reaction monitoring, capture reagents, magnetic beads, chromatographic conditions, evaluations of selectivity, and matrix effect. The final assay used viral spike protein receptor-binding domain as capture reagent and signature proteotypic peptides from the complementarity-determining region of each mAb for detection. In contrast to other methods of similar/superior sensitivity, our approach did not require multidimensional separations and can be operated in an analytical flow regime, ensuring high throughput and robustness required for clinical analysis at scale. The sensitivity of this method significantly exceeds typical sensitivity of ∼100 ng/mL for analytical flow 1D LBA-LC-MS/MS methods for large macromolecules, such as antibodies. Furthermore, infection and vaccination status did not impact method performance, ensuring method robustness and applicability to a broad patient population. This report demonstrated the general applicability of the hybrid LBA-LC-MS/MS approach to platform quantification of antibodies with high sensitivity and reproducibility, with specialized extension to matrices of increasing interest, such as NLF.

[International multi-center evaluation of a rapid antigen test based on gold immunochromatographic assay for detection of severe acute respiratory syndrome coronavirus 2]

Objective: The gold immunochromatographic assay for detection of SARS-CoV-2 antigen was evaluated by international multi-center clinical trial. Methods: A total of 1 855 clinical parallel samples with valid test results (for nucleic acid and antigen tests, respectively) were collected from nine countries, including Germany, the United Kingdom, Ukraine, France, India, Thailand, Malaysia, the United States of America and Brazil, with sampling period from January 3 to September 22, 2021. These samples were detected by SARS-CoV-2 antigen test kit (colloidal gold immunochromatography assay) and nucleic acid detection kit (real-time fluorescent quantitative reverse transcription polymerase chain reaction). Positive coincidence rates [(number of antigen-positive cases/nucleic acid-positive cases)×100%], negative coincidence rates [(number of antigen-negative cases/nucleic acid-negative cases)×100%], total coincidence rates [(number of cases with consistent results for both antigen and nucleic acid detection/number of total cases) ×100%], as well as Kappa values were calculated. The differences of the above indictors among different countries were evaluated by the coefficient of variation. The detection rates of the antigen test for samples with different cycle threshold values (Ct values) for the nucleic acid detection, different characteristics and different mutant strains were analyzed. Results: For all samples, the positive, negative, and total coincidence rate between the antigen test and nucleic acid assay was 90.8% (569/627), 99.7% (1 224/1 228) and 96.7% (1 793/1 855), respectively, and the consistency coefficient Kappa value was 0.924. Among these countries, the coefficient of variation for positive coincidence rates (except for Malaysia with a lot of samples with Ct value>30), negative coincidence rates (except for France without negative samples) and total coincidence rates (except for France) was 6%,<1%, and 6%, respectively. When Ct values were less than 25, the detection rates of antigen test were 83.3%-100% for each countries (the coefficient of variation was 6%); the total detection rate and the coefficient of variation was 93.4% (428/458) and 5%, respectively, for asymptomatic infected persons and cases within 7 days post onset of symptoms; the total detection rate for various SARS-CoV-2 mutant strains was 97.5% (119/122); and it showed negative results for samples from cases infected with other viruses, including influenza A virus subtype H1N1, influenza B virus, respiratory syncytial virus subgroups A and B, coxsackievirus 16, human metapneumovirus, parainfluenza virus types 1 and 4, Epstein-Barr virus and adenovirus. Conclusion: The SARS-CoV-2 antigen test kit showed excellent authenticity, and there were few differences for its indictors among nine countries, therefore it can meet the needs of large-scale early screening of SARS-CoV-2 infection.

[International multi-center evaluation of a rapid antigen test based on gold immunochromatographic assay for detection of severe acute respiratory syndrome coronavirus 2]

Objective: The gold immunochromatographic assay for detection of SARS-CoV-2 antigen was evaluated by international multi-center clinical trial. Methods: A total of 1 855 clinical parallel samples with valid test results (for nucleic acid and antigen tests, respectively) were collected from nine countries, including Germany, the United Kingdom, Ukraine, France, India, Thailand, Malaysia, the United States of America and Brazil, with sampling period from January 3, 2021 to September 22, 2021. These samples were detected by SARS-CoV-2 antigen test kit (colloidal gold immunochromatography assay) and nucleic acid detection kit (real-time fluorescent quantitative reverse transcription polymerase chain reaction). Positive coincidence rates [(number of antigen-positive cases/nucleic acid-positive cases)×100%], negative coincidence rates [(number of antigen-negative cases/nucleic acid-negative cases)×100%], total coincidence rates [(number of cases with consistent results for both antigen and nucleic acid detection/number of total cases) ×100%], as well as Kappa values were calculated. The differences of the above indictors among different countries were evaluated by the coefficient of variation. The detection rates of the antigen test for samples with different cycle threshold values (Ct values) for the nucleic acid detection, different characteristics and different mutant strains were analyzed. Results: For all samples, the positive, negative, and total coincidence rate between the antigen test and nucleic acid assay was 90.8% (569/627), 99.7% (1 224/1 228) and 96.7% (1 793/1 855), respectively, and the consistency coefficient Kappa value was 0.924. Among these countries, the coefficient of variation for positive coincidence rates (except for Malaysia with a lot of samples with Ct value>30), negative coincidence rates (except for France without negative samples) and total coincidence rates (except for France) was 6%,<1%, and 6%, respectively. When Ct values were less than 25, the detection rates of antigen test were 83.3%-100% for each countries (the coefficient of variation was 6%); The total detection rate and the coefficient of variation was 93.4% (428/458) and 5%, respectively, for asymptomatic infected persons and cases within 7 days post onset of symptoms; the total detection rate for various SARS-CoV-2 mutant strains was 97.5% (119/122); and it showed negative results for samples from cases infected with other viruses, including influenza A virus subtype H1N1, influenza B virus, respiratory syncytial virus subgroups A and B, coxsackievirus 16, human metapneumovirus, parainfluenza virus types 1 and 4, Epstein-Barr virus and adenovirus. Conclusion: The SARS-CoV-2 antigen test kit showed excellent authenticity, and there were few differences for its indictors among nine countries, therefore it can meet the needs of large-scale early screening of SARS-CoV-2 infection.

AB0711 The Impact of Anemia on Systemic Organ Damage in Systemic Sclerosis

Background

Systemic sclerosis (SSc) is a systemic autoimmune disease with multiple organ damage. Scleroderma Clinical Trials Consortium (SCTC) has developed the Damage Index (DI) in SSc to quantify organ damage in SSc[1]. Anemia has been implicated as an independent prognosis factor for mortality and organ complications in systemic sclerosis (SSc), while the relationship between anemia and the weighted organ damage index has not been reported.

Objectives

To determine the degree and feature of organ damage in SSc patients with or without anemia in a population of patients from Peking University Third Hospital SSc cohort (PKUTH-SSc).

Methods

Patients were recruited from PKUTH-SSc between January, 2010 and December, 2021. The diagnosis of anemia was based on the reduced hemoglobin (Hb) concentrations (<120g/L for female and <135g/L for male). The demographics, clinical characteristics, laboratory parameters, autoantibodies medication and SCTC-DI were collected. Student‘s t-test and Chi-square were used.

Results

As shown in Table 1, a total of 155 patients were enrolled in PKUTH-SSc cohort, 70 (45.2%) patients developed anemia, older and lower BMI than non-anemia patients. The inflammatory indices, ESR and CRP, were higher in anemia patients, indicating anemia was more common in patients with active disease. Consistent with the result that the positive rate of anti-SSA and anti-SSB antibody was higher in anemia patient, the sicca symptoms were also reported in nearly half of anemia patients. In anemia patients, the Gastrointestinal system related damage, Oesophageal dysmotility, Pseudo-obstruction and weight loss, and renal damage were more frequently discovered. Moreover, anemia patients were more likely to develop moderate to high organ damage risk, demonstrating the necessary of regular organ damage follow-up for anemia patients.

Table 1.

Clinical parameters and SCTC-DI of SSc patients with or without anemia

AnemiaN=72Non-anemiaN=83p valueAge at baseline (years)54.43±1.8849.64±1.320.034*BMI (kg/m2) (meanyear20.49±0.4022.46±0.39<0.001*ESR32.48±3.0616.67±1.83<0.001CRP1.20±0.220.64±0.110.014*Anti-SSA22 (31.4%)13 (15.3%)0.017*Anti-SSB8 (11.4%)1 (1.2%)0.018*Musculoskeletal and skin2.22±.22u1.11±.11u<0.001*Sicca symptoms31 (44.3%)22 (25.9%)0.016*Vascular0.67±.67u0.59±.59u0.628Gastrointestinal2.09±.09r1.31±.31r<0.001*Oesophageal dysmotility27 (38.6%)18 (21.2%)0.018*Pseudo-obstruction5 (7.1%)0 (0.0%)0.017*BMI<18.5 kg/m2 or weight loss >10% in the last 12 months40 (57.1%)31 (36.5%)0.010*Respiratory2.24±.24i1.59±.59i0.132Cardiovascular0.94±.94i0.66±.66i0.468Renal0.21±.21l0.00±.00l0.027*History of SRC4 (5.7%)0 (0.0%)0.040*SCTC-DI8.37±.37-5.25±.25-<0.001*Moderate to high damage score48 (68.6%)31 (36.5%)<0.001*

Conclusion

Anemia is associated with distinct organ damage behaviors and higher disease progression risk in SSc. Specifically Sicca symptoms and gastrointestinal, renal system were more common in SSc patients with anemia.

References

[1]Ferdowsi N, Huq M, Stevens W, et al. Development and validation of the Scleroderma Clinical Trials Consortium Damage Index (SCTC-DI): a novel instrument to quantify organ damage in systemic sclerosis [published correction appears in Ann Rheum Dis. 2019 Aug;78(8):e88]. Ann Rheum Dis. 2019;78(6):807-816. doi:10.1136/annrheumdis-2018-214764

Disclosure of Interests

None declared

Bioanalytical Methods and Strategic Perspectives Addressing the Rising Complexity of Novel Bioconjugates and Delivery Routes for Biotherapeutics

In recent years, an increase in the discovery and development of biotherapeutics employing new modalities, such as bioconjugates or novel routes of delivery, has created bioanalytical challenges. The inherent complexity of conjugated molecular structures means that quantification of the bioconjugate and its multiple components is critical for preclinical/clinical studies to inform drug discovery and development. Moreover, bioconjugates involve additional multifactorial complexity because of the potential for in vivo catabolism and biotransformation, which may require thorough investigations in multiple biological matrices. Furthermore, excipients that enhance absorption are frequently evaluated and employed for the development of oral and inhaled biotherapeutics. Risk-benefit assessments are required for novel or existing excipients that utilize dosages above previously approved levels. Bioanalytical methods that can measure both excipients and potential drug metabolites in biological matrices are highly relevant to these emerging bioanalysis challenges. We discuss the bioanalytical strategies for analyzing bioconjugates such as antibody-drug conjugates and antibody-oligonucleotide conjugates and review recent advances in bioanalytical methods for the quantification and characterization of novel bioconjugates. We also discuss bioanalytical considerations for both biotherapeutics and excipients through novel administration routes and review analyses in various biological matrices, from the extensively studied serum or plasma to tissue biopsy in the context of preclinical and clinical studies from both technical and regulatory perspectives.

Differences in levels of phosphatidylinositols in healthy and stable Coronary Artery Disease subjects revealed by HILIC-MRM method with SERRF normalization

Quantification of endogenous biomarkers in clinical studies requires careful evaluation of a number of assay performance parameters. Comparisons of absolute values from several clinical studies can enable retrospective analyses further elucidating the biology of a given biomarker across various study populations. We characterized the performance of a highly multiplex bioanalytical method for quantification of phosphatidylinositols (PI). Hydrophilic interaction chromatography (HILIC) and multiple reaction monitoring (MRM) were employed for targeted multiplex quantification. Odd-chain PI species that are not normally present in human plasma were utilized as surrogate analytes (SA) to assess various assay performance parameters and establish a definitive dynamic linear range for PI lipids. To correct for batch effects, Systematic Error Removal using Random Forest (SERRF) normalization algorithm was employed and used to bridge raw values between two clinical studies, enabling quantitative comparison of their absolute values. A high throughput method was developed, qualified, transferred to an automation platform and applied to sample testing in two clinical trials in healthy volunteers (NCT03001297) and stable Coronary Artery Disease (CAD, NCT03351738) subjects. The method demonstrated acceptable precision and accuracy (±30%) over linear range of 1-1000 nM for SA and 8-fold dilutional linearity for endogenous PI. We determined that mean-adjusted average QC performed best for normalization using SERRF. The comparison of two studies revealed that healthy subject levels of PI are consistently higher across PI species compared to CAD subjects identifying a potential lipid biomarker to be explored in future studies.

POS0437 IMPROVEMENTS IN PATIENT-REPORTED OUTCOMES IN RHEUMATOID ARTHRITIS PATIENTS TREATED WITH GOLIMUMAB: SUB-ANALYSIS OF ASIAN PATIENTS ENROLLED IN PHASE-3 CLINICAL TRIALS

Background:

Clinical efficacy and safety of Tumour Necrosis Factor-alpha inhibitor golimumab (GLM) for patients with rheumatoid arthritis (RA) and inadequate response to methotrexate (MTX) were studied in phase-3 clinical trials. A greater proportion of patients treated with GLM 50 mg every 4 weeks (q4w) achieved improvement in clinical signs and symptoms, measured by American College of Rheumatology 20% improvement (ACR20) response and patient-reported outcomes (PROs) when compared with placebo (PBO) at Weeks 14 and 24.

Objectives:

To assess PROs in RA patients from Asia treated with GLM in phase-3 trials.

Methods:

Post-hoc PRO (Health Assessment Questionnaire [HAQ], Short-Form 36 [SF-36] physical component score [PCS] and mental component score [MCS], pain, and work productivity) sub-analysis of RA patients from China (including Taiwan region) and South Korea with inadequate response to MTX randomized to subcutaneous GLM 50 mg + MTX or PBO + MTX from 2 clinical trials (GO-FORWARD, NCT01248780).

Clinically meaningful improvement was defined as improvement of ≥0.25 point in HAQ or ≥5 points in SF-36 PCS and MCS. Nominal p-values were used for descriptive and exploratory purposes.

Results:

At Week 24, MTX-experienced patients from Asia treated with GLM + MTX demonstrated improvements versus PBO + MTX in all PROs analyzed. Pooled patients from Asia on GLM + MTX had greater improvements at Week 24 in all measures of PROs than patients with PBO + MTX, and the improvements are comparable to all other regions (Table 1). Greater proportions of RA patients from Asia in GLM group than PBO achieved clinically meaningful improvement in HAQ, SF-36 PCS, and SF-36 MCS (Figure 1).

Conclusion:

MTX-experienced RA patients from Asia treated with GLM demonstrated improved PROs after 24 weeks. The pooled results were comparable with patients enrolled from all other regions and demonstrated clinical meaningful improvements in HAQ, SF-36 PCS, and SF-36 MCS.

Table 1.

Summary of Improvement from Baseline in HAQ-DI, HRQoL, Pain, and Work Productivity at Week 24: Randomized Patients in RA Studies Pooled for Regions Outside Asia and Randomized Patients from Asia

MTX experienced from AsiaPooled RA in All Other RegionsPlacebo + MTX(N=152)GLM50 mg + MTX(N=146)DifferencePlacebo + MTX(N=107)GLM50 mg + MTX(N=74)DifferenceMean (SD)Mean (SD)Mean (SE)Nominal p-valueMean (SD)Mean (SD)Mean (SE)Nominalp-valueHAQ-DI-0.13 (0.670)0.28 (0.575)0.41 (0.072)<.0010.18 (0.596)0.48 (0.540)0.30 (0.087)<.001SF-36 PCS-0.57 (7.011)4.73 (7.034)5.30 (0.814)<.0014.77 (8.343)*8.67 (8.862)3.90 (1.299)0.003SF-36 MCS-1.89 (11.866)1.87 (10.833)3.76 (1.318)0.0051.31 (9.440)*3.80 (10.969)2.50 (1.533)0.105Pain VAS-0.00 (2.437)1.46 (2.940)1.46 (0.312)<.0010.76 (2.776)2.72 (2.586)1.96 (0.408)<.001Productivity VAS0.17 (2.601)1.74 (2.599)1.57 (0.301)<.0011.09 (2.976)2.38 (2.889)1.28 (0.445)0.004

GLM, golimumab; HAQ-DI, health assessment questionnaire disability index; HRQoL, health-related quality of life; MTX, methotrexate; RA, rheumatoid arthritis; SD, standard deviation; SE, standard error; SF-36 MCS, short-form 36 mental component score; SF-36 PCS, short-form 36 physical component score; VAS, visual analogue scale

*N=105

Figure 1.

Proportion of Patients with Clinical Meaningful Improvements in HAQ and HRQoL: Randomised Subjects from China, Taiwan and Korea

Disclosure of Interests:

Wen-Chan Tsai Consultant of: Pfizer, AbbVie, Roche, and Eli Lilly, Rong Mu: None declared, Chang-Hee Suh: None declared, Daniel Furtner Shareholder of: Johnson & Johnson, Employee of: Johnson & Johnson Pte. Ltd., Kim Hung Lo Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development, LLC, Yiying Zhou Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development, LLC, Elizabeth C Hsia Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development, LLC

POS1439 A MULTI-PREDICTOR MODEL TO PREDICT RISK OF SCLERODERMA RENAL CRISIS IN SYSTEMIC SCLEROSIS

Background:

Scleroderma renal crisis (SRC) is a life-threatening syndrome. The early identification of patients at risk is essential for timely treatment to improve the outcome[1].

Objectives:

We aimed to provide a personalized tool to predict risk of SRC in systemic sclerosis (SSc).

Methods:

We tried to set up a SRC prediction model based on the PKUPH-SSc cohort of 302 SSc patients. The least absolute shrinkage and selection operator (Lasso) regression was used to optimize disease features. Multivariable logistic regression analysis was applied to build a SRC prediction model incorporating the features of SSc selected in the Lasso regression. Then, a multi-predictor nomogram combining clinical characteristics was constructed and evaluated by discrimination and calibration.

Results:

A multi-predictor nomogram for evaluating the risk of SRC was successfully developed. In the nomogram, four easily available predictors were contained including disease duration <2 years, cardiac involvement, anemia and corticosteroid >15mg/d exposure. The nomogram displayed good discrimination with an area under the curve (AUC) of 0.843 (95% CI: 0.797-0.882) and good calibration.

Conclusion:

The multi-predictor nomogram for SRC could be reliably and conveniently used to predict the individual risk of SRC in SSc patients, and be a step towards more personalized medicine.

References:

[1]Woodworth TG, Suliman YA, Li W, Furst DE, Clements P (2016) Scleroderma renal crisis and renal involvement in systemic sclerosis. Nat Rev Nephrol 12 (11):678-91.

Disclosure of Interests:

None declared

AB0095 EXPRESSION AND PATHOGENIC ROLES OF INTEGRIN FAMILY GENE IN SYSTEMIC SCLEROSIS

Background:

Emerging evidence have shown that some integrin members are associated with inflammation and fibrosis in systemic sclerosis (SSc) patients[1-2]. However, the expression patterns and pathogenic significance of the whole integrin family in SSc are still unclear.

Objectives:

This study aimed at evaluating the integrin family gene expression in skin lesion from SSc patients and exploring its potential pathogenic mechanism.

Methods:

We utilized the public datasets of SSc skin tissue from Gene Expression Omnibus (GEO) database to analyze the expression and clinical significance of integrin family genes in SSc. In addition, functional enrichment and pathway analysis were also conducted.

Results:

Compared with healthy controls, ITGA5, ITGA7, ITGA8, ITGB2, ITGB5, ITGAE and ITGB3BP were abnormally overexpressed in the skin of SSc. Further analysis indicated that ITGA5, ITGA7, ITGA8, ITGB2 and ITGB5 were positively correlated with modified Rodnan skin thickness score (mRSS), while ITGAE and ITGB3BP were negatively correlated with mRSS in SSc. Increased ITGB5 expression was associated with positive of anti-centromere antibody (ACA). Functional enrichment and pathway analysis showed that integrin members had multiple functions in SSc. Among them, ITGA5, ITGB2 and ITGB5 might synergistically promote SSc through affecting extracellular matrix (ECM) turn over, ECM-receptor interaction, focal adhesion and leukocyte trans-endothelial migration. ITGA5 and ITGB5 also affected angiogenesis and endothelial cell function. In addition, ITGA5 was uniquely enriched for actin organization, ITGB5 was uniquely enriched for TGF-β signaling, and ITGB2 was uniquely associated with immune cells activation.

Conclusion:

Our results implied that integrins, especially ITGA5, ITGB5, ITGB2 participated in the process of inflammation, vasculopathy and fibrosis in SSc. Together, they might render important therapeutic targets for SSc.

References:

[1]Brown M, O’Reilly S. The immunopathogenesis of fibrosis in systemic sclerosis. Clin Exp Immunol. 2019;195(3):310-321.

[2]Gerber, E.E., et al., Integrin-modulating therapy prevents fibrosis and autoimmunity in mouse models of scleroderma. Nature, 2013. 503(7474): p. 126-30.

Disclosure of Interests:

None declared

AB0831 FREQUENCY OF RENAL CRISIS IN PATIENTS WITH SYSTEMIC SCLEROSIS: NEW DATA FROM A CHINESE COHORT AND A SYSTEMIC REVIEW WITH META-ANALYSIS

Background:

Scleroderma renal crisis (SRC) is a rare but life-threatening complication in SSc, which defined as malignant hypertension and progressive renal failure [1]. Previous reports of the prevalence for scleroderma renal crisis (SRC) show variable outcomes.

Objectives:

We aim to find out the prevalence for SRC in Chinese, and conduct a meta-analysis to assess the prevalence of SRC in worldwide and investigate possible factors of variability.

Methods:

We evaluated the prevalence for SRC and compared the clinical characteristics in SSc patients with or without SRC. A systematic review on the prevalence of SRC was carried out in PubMed, Embase and Cochrane. Meta-analysis was performed using available data on the prevalence for SRC.

Results:

302 patients were enrolled in PKUPH-SSc cohort and the prevalence of SRC was 4.97%. In our cohort, SRC was found in 3.60% limited cutaneous SSc (lcSSc) and 7.75% diffused cutaneous SSc (dcSSc) patients. Twenty-nine studies including a total population of 22686 SSc patients were analyzed in the meta-analysis. The overall pooled prevalence of SRC was 4.0%, but heterogeneity among the studies was substantial (I2=86.1%, P <0.00001). Meta-regression revealed that subtype of SSc and geographic factors partially explained this heterogeneity. Sub-group analyses demonstrated that the prevalence of SRC in dcSSc and lcSSc were 9.0% and 2.0%. The SRC prevalence in SSc was 3.0% in Asia, 5.0% in Europe, and 3.0% in North America, respectively.

Conclusion:

Data on our new cohort showed the prevalence of SRC was around 5% in China, and meta-analysis confirmed that the prevalence of SRC varies among centers. The marked heterogeneity of SRC prevalence was partially explained by subtype of SSc and geographic origin of patients.

References:

[1]Woodworth TG, Suliman YA, Li W, Furst DE, Clements P (2016) Scleroderma renal crisis and renal involvement in systemic sclerosis. Nat Rev Nephrol 12 (11):678-91.

Disclosure of Interests:

None declared

Characterization of Antibody-Drug Conjugate Pharmacokinetics and in Vivo Biotransformation Using Quantitative Intact LC-HRMS and Surrogate Analyte LC-MRM

Antibody-drug conjugates (ADCs) pose challenges to bioanalysis because of their inherently intricate structures and potential for very complex catabolism. Common bioanalysis strategy is to measure the concentration of ADCs and Total Antibody (Ab) as well as deconjugated warhead in circulation. The ADCs and the Total Ab can be quantified with ligand binding assays (LBA) or with hybrid immunocapture-liquid chromatography coupled with multiple reaction monitoring mass spectrometry (LBA-LC-MRM). With the LBA-LC-MRM approach, a surrogate analyte, often the signature peptide, and released warhead can be used for the quantification of the Total Ab and ADCs, respectively. Recent advances in analytical instrumentation, especially the development of high resolution mass spectrometers (HRMS), have enabled characterization and quantification of intact macromolecules such as ADCs. The LBA-LC-HRMS approach employs immunocapture, followed by chromatographic separation at the macromolecule level and detection of the intact analyte. We developed an intact quantification method with 1-10 μg/mL linear dynamic range using 25 μL of plasma sample volume. This method was qualified for the measurement of naked monoclonal antibody (mAb), a site-specific cysteine-conjugated ADC with drug to antibody ratio ∼2 (DAR2) and a site-nonspecific cysteine-conjugated ADC (DAR8) in rat plasma. Samples from a rat pharmacokinetic (PK) study were analyzed with both methods. For the naked mAb, the results from both assays matched well. For ADCs, new species were observed from the LBA-HRMS method. The results demonstrated that potential biotransformation of the ADC was unveiled using the intact quantification approach while not being observed with traditional LBA-LC-MRM approach. Our work demonstrated an application of novel intact quantification by supporting animal PK studies. Moreover, our results suggest that the intact quantification method can provide novel perspectives on ADC in vivo characterization and quantification, which can benefit future drug candidate optimization as well as the immunogenicity impact evaluation and safety assessment.

SAT0647-HPR DEVELOP A MACHINE LEARNING MODEL AND ALGORITHM BASED ON SMART SYSTEM OF DISEASE MANAGEMENT (SSDM) BIG DATA FOR RA FLARE PREDICTION

Background:

Flare, relapse from status of treat-to-target (T2T, DAS28<=3.2), is hard predicted. We try to make it predictable by applying machine learning to a database from smart system of disease management (SSDM). SSDM is an interactive mobile disease management APPs.

Objectives:

To develop and validate machine learning algorithms for flare prediction in RA.

Methods:

Patients were trained using SSDM and input their data, including demographic, comorbidities (COMBs), lab test, medications and monthly self-assessments, including DAS28, HAQ, SF-36, Hospital Anxiety and Depression Scale (HADS). The data was uploaded to cloud and synchronized to the mobile of authorized rheumatologists. The COMBs were by ICD-9, and medications were listed as cDMARDs, Bio (BioDMARDs), NSAIDs, Steroid, FS (food supplements), MC (medicine for COMBs), TCM (Traditional Chinese Medicine), and combinations.

Results:

From Jan of 2015 to Jan of 2020, 8811 RA patients, 85% female and 15% male, used to reach T2T. 4556 were flare-free and 4255 suffering at least one flare. The average 160 attributes were extracted from each flare-free patient at time of reaching T2T, and each flare patients at time of 3 months before the flare. Patients were randomly assigned as model setup (training) group (70%) and validation (testing) group30%.

For training, data were processed using Python with statistical analyses in R. In R, random forests were implemented. Logistic regression via glm in base R. The random forest comprises a set of decision trees. “Splits” in the decision trees reflect binary (i.e., yes/no) respect to attributors. Bootstrapping was used to assess, quantify, and adjust for model optimism. Model performance was evaluated using AUC, precision and recall metrics. Brier scores for accuracy of probabilistic predictions ranged from 0 to 1 (0 is perfect discrimination).

The testing showed model performance for prediction windows are 0.78 for AUC (95% CI), 0.71 for Recall (sensitivity), 0.195 for Brier score, and 0.68 for precision (true positive 893, false positive 417, false negative 367, true negative 966).

Based on weighing in the random forest, the top 10 pro-flare attributes were CRP, swollen joint count (SJC), tender joint count (TJC), HAQ, DAS28, morning stiffness, gout, MCTD, OA, duration; while top 10 anti-flare attributes were cDMARDs+Bio, cDMARDs+steroid+NSAIDs, stable on HAQ, on morning stiffness, on SJC, medicine on COMBs, cDMARDs+TCM, stable on TJC, on ESR, income at 100-200k (Fig.1). The top weighing COMBs for pro-flaring were gout (0.81), MRD (0.75), OA (0.56), AS (0.48). The monotherapies with either Bio or NSAIDs, or steroid, or TCM was pro-flare; while with cDMARDs was anti-flare (-0.21).

Figure 1.

Conclusion:

The attempt to develop a machine learning algorithm for RA flare prediction is successful. The discrimination was acceptable. The attributes of both pro-flare and anti-flare are identified, which may inspire the proactive intervention.

Acknowledgments:

SSDM was developed by Shanghai Gothic Internet Technology Co., Ltd.

Disclosure of Interests:

None declared

T cell vaccination in systemic lupus erythematosus with autologous activated T cells

Systemic lupus erythematosus (SLE) is an autoreactive T cell mediated autoimmune disease. Immunization with inactivated autoreactive T cells may induce idiotype anti-idiotypic reaction to deplete specific subsets of autoreactive T cells involved in SLE. Six SLE patients unsuitable or refused to use immunosuppressants were treated with T cell vaccination. Their clinical manifestations and laboratory parameters including mixed lymphocyte reactions were evaluated. Autoreactive T cell clones were derived from peripheral blood mononuclear cells of the patients and 1 × 107 irradiated T cells were inoculated subcutaneously at 0, two, six and eight weeks, respectively. The enrolled patients were followed up for 32-40 months at an interval of three to six months. The clinical characteristics and laboratory abnormalities improved after inoculation without increasing the dose of corticosteroids and immunosuppressants in most patients. SLE disease activity index (SLEDAI) scores decreased. Proliferative responses against the T cell vaccine were observed in four of six patients. At the time of this report, the six patients remain in clinical remission. No significant side effect from the vaccination was noticed during the follow-up period. The results of this pilot study indicate that T cell vaccination is a safe and effective treatment in SLE.

Probing plasmons in three dimensions by combining complementary spectroscopies in a scanning transmission electron microscope

The nanoscale optical response of surface plasmons in three-dimensional metallic nanostructures plays an important role in many nanotechnology applications, where precise spatial and spectral characteristics of plasmonic elements control device performance. Electron energy loss spectroscopy (EELS) and cathodoluminescence (CL) within a scanning transmission electron microscope have proven to be valuable tools for studying plasmonics at the nanoscale. Each technique has been used separately, producing three-dimensional reconstructions through tomography, often aided by simulations for complete characterization. Here we demonstrate that the complementary nature of the two techniques, namely that EELS probes beam-induced electronic excitations while CL probes radiative decay, allows us to directly obtain a spatially- and spectrally-resolved picture of the plasmonic characteristics of nanostructures in three dimensions. The approach enables nanoparticle-by-nanoparticle plasmonic analysis in three dimensions to aid in the design of diverse nanoplasmonic applications.

OsMYB511 encodes a MYB domain transcription activator early regulated by abiotic stress in rice

The MYB-domain proteins exist universally across diverse organisms and regulate numerous processes during the plant life cycle. In the present research, a full-length MYB gene OsMYB511 was identified from rice seedlings through microarray data. Induction of OsMYB511 by cold stress was dramatic in japonica cultivar Jiucaiqing as compared to indica IR26. In addition to cold, OsMYB511 was also markedly induced by osmotic stress, high temperature, and exogenous ABA, suggesting that OsMYB511 is a multiple-stress responsive gene in rice. Tissue-specific expression analysis indicated that OsMYB511 was highly expressed in rice panicles at earlier development stage. Interestingly, OsMYB511 expression is fully subjected to circadian rhythm regulation. The subcellular localization and yeast hybrid assay suggested that OsMYB511 is nucleus-localized transcription activator. Deletion analysis suggested that trans-activation activity of OsMYB511 relied on its C-terminus. Co-expression analysis revealed additional 2 MYB genes co-expressed with OsMYB511, implying that these MYB genes might coordinately regulate stress responses in rice.

Clinical and laboratory profiles of rhupus syndrome in a Chinese population: a single-centre study of 51 patients

OBJECTIVE

The objective of this paper is to clarify the demographic, clinical and serologic characteristics of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) overlap syndrome, known as 'rhupus syndrome'.

METHODS

Between 1995 and 2012, 51 patients were classified as having rhupus among 3733 consecutive SLE patients. Rhupus was defined as a condition involving an overlap of RA and SLE features meeting the respective criteria of the American College of Rheumatology. The clinical and laboratory parameters of patients with rhupus syndrome were compared with those of 230 RA patients and 120 unselected SLE patients.

RESULTS

The age at the onset of rhupus was significantly younger than that of RA (p < 0.05), but similar to that of SLE. The initial manifestation was arthritis in 84.3% (43/51) of rhupus patients. Symptoms of SLE manifested after an average of 9.2 years. SLE was the initial diagnosis in 7.8% (four of 51) of patients, whereas both diseases developed simultaneously in 7.8% of the patients. SLE-associated manifestations were mild in rhupus syndrome, particularly neurologic disorders. Haematopoietic involvement was the most prominent systemic manifestation in rhupus patients.

CONCLUSION

Rhupus syndrome constitutes a subgroup of patients with distinct demographic, clinical and immunological characteristics. RA typically presents first, and less-severe SLE-associated damage is apparent.

Research potential of multi-lineage chicken amniotic mesenchymal stem cells

Amniotic mesenchymal stem cells (AMSCs) express octamer binding transcription factor 4 (Oct-4), which is necessary for maintaining the undifferentiated state of pluripotent stem cells. AMSCs also express CD29, CD44 and vimentin, which are specific markers of mesenchymal cells. We studied the biological characteristics and potential for cell therapy of AMSCs derived from 8-day-old chicken embryos. We induced the AMSCs to differentiate into adipocytes, osteoblasts and myocardial cells and used immunofluorescence, reverse transcription-polymerase chain reaction (RT-PCR) assays to detect the expressions of specific markers of AMSCs and differentiated cells. To assess the differentiation capacity of AMSCs, passage four cells were induced to differentiate into adipocytes, osteoblasts and myocardial cells. These results suggested that AMSCs isolated from chicken embryos exhibited the characteristics of multipotent stem cells. AMSCs, therefore, may be potential candidates for cellular transplantation therapy and tissue engineering.

Optical and Structural Characterization of Zinc Implanted Silica Under Various Thermal Treatments

Zinc ion implanted silica with controlled thermal annealing has been investigated. Low temperature optical measurements indicate the presence of Zn clusters in the as-implanted silica. Optical spectra of the annealed sample under a reducing environment suggest Zn cluster and Zn metal colloid formation. The absorption peak at ∼5.3 eV may be due to the surface plasma absorption of Zn metal colloids in silica. The oxidized samples (10 and 6 x 1016 ions/cm2) show an absorption peak at ∼4.3 and ∼4.8 eV, respectively and imply ZnO quantum dot formation. The blueshift in exciton absorption can be attributed to the quantum confinement effects.

Selective Purcell enhancement of defect emission in ZnO thin films

A zinc interstitial defect present but unobservable in ZnO thin films annealed at 500 °C in oxygen or in atmosphere was selectively detected by interaction of the film with an Ag surface-plasmon polariton. The time-dependent differential reflectivity of the ZnO near the ZnO/MgO interface exhibited a subpicosecond decay followed by a several nanosecond recovery, consistent with the Purcell-enhanced Zn interstitial luminescence seen in Ag-ZnO heterostructures. Heterostructures annealed at other temperatures showed significantly greater band-edge photoluminescence and no evidence of the Zn interstitial defect.

Subclinical hypothyroidism and its association with lupus nephritis: a case control study in a large cohort of Chinese systemic lupus erythematosus patients

The aim of this study was to evaluate the prevalence of thyroid diseases in Chinese systemic lupus erythematosus (SLE) patients and the relevance of subclinical hypothyroidism (SCH) with lupus nephritis (LN). A large cohort of 1006 SLE patients was retrospectively analyzed. The prevalence of autoimmune thyroid disease was 2.78%, clinical hypothyroidism 1.69%, subclinical hypothyroidism 10.04%, central hypothyroidism 1.29%, hyperthyroidism 1.19%, euthyroid sick syndrome (ESS) 9.54%, and nodules 1.09%, respectively. Compared with the prevalence of thyroid abnormalities in the general Chinese population (0.91–6.05%), SCH was much higher (10.04%) in this study. In addition, SCH was more frequent in patients with LN (13.4%) than those without LN (7.3%, p = 0.001). Case control study was performed to explore the relative risk factors of SCH. In multiple logistic regression models, 24 h urine protein and estimated glomerular filtration rate (eGFR) were retained as independent correlates of SCH after adjusting for demographic variables, risk factors, and other potential confounders. The results of the present study suggest that SCH is a common complication in SLE patients, and closely related with LN.

Nanocrystals and Quantum Dots Formed by High-Dose Ion Implantation

Ion implantation and thermal annealing have been used to produce a wide range of nanocrystals and quantum dots in amorphous (SiO2) and crystalline (AI2O3) matrices. Nanocrystals of metals (Au), elemental semiconductors (Si and Ge), and even compound semiconductors (SiGe, CdSe, CdS) have been produced. In amophous matrices, the nanocrystals are randomly oriented, but in crystalline matrices they are three dimensionally aligned. Evidence for photoluminescence and quantum confinement effects are presented.

Silicon Quantum Dots in Silica

Silicon ions were implanted into fused silica substrates at doses of 1×1021, 2×1021, 5×1021, and 1×1022 ions/cm3. The implanted substrates were annealed at 1100°C for one hour in a reducing atmosphere (95% Ar+5% H2). Optical absorption spectra recorded after the annealing treatment showed absorption onsets at 3.86, 3.73, 2.86 and 2.52 eV for substrates implanted with 1×1021, 2×1021, 5×1021, and 1×1022 ions/cm3, respectively. Static photoluminescence (PL) measurements indicated red emission between 1.72 and 1.61 nm with a slightly increasing red shift with ion dose. Time resolved PL at room temperature revealed slow (∼50 μs) and fast (×20 μs) lifetimes which increased with decreasing temperature. TEM studies showed that the particle size increased with increasing ion dose. Typical particle sizes ranged between 2 and 5 nm indicating quantum confinement of the exciton, which can account for the blue shift in the absorption edge with decreasing ion dose. However, the maxima in the PL spectra for all ion doses are relatively independent of the ion dose and are strongly shifted from the absorption spectra. This suggests that radiative recombination occurs from a common luminescent center, possibly a surface or interfacial state in thexs SiOx, layer surrounding the nanocrystal.

Increased short circuit current in organic photovoltaic using high-surface area electrode based on ZnO nanowires decorated with CdTe quantum dots

A photosensitized high-surface area transparent electrode has been employed to increase the short circuit current of a photovoltaic device with a blend of poly(3-hexylthiophene) (P3HT) and (6,6)-phenyl C61 butyric acid methyl ester (PCBM) as the active layer. This is achieved by directly growing ZnO nanowires on indium tin oxide (ITO) film via a physical vapor method. The nanowire surface is then decorated with CdTe quantum dots by pulsed electron-beam deposition (PED). The nanowires alone provided a 20-fold increase in the short circuit current under visible light illumination. This was further increased by a factor of approximately 1.5 by the photosensitization effect of CdTe, which has an optical absorption of up to 820 nm.

Enhancement of ZnO photoluminescence by localized and propagating surface plasmons

Insulating spacer layers of MgO were used to identify the enhancement mechanisms of the ZnO band-edge and visible luminescence in ZnO-MgO-Ag and ZnO-MgO-Au multilayers. Purcell enhancement of the ZnO band-edge emission by both Ag and Au surface plasmon polaritons is confirmed by demonstrating that the exponential decay of this emission as a function of increasing MgO thickness is consistent with the Ag and Au SPP evanescent decay lengths. Local surface plasmons excited in Ag and Au nanoparticles and rough films are also shown to enhance the ZnO visible donor-acceptor-pair photoluminescence by dipole-dipole scattering, again with an appropriate dependence on the thickness of the MgO spacer layer. We also confirm that both Ag and Au nanoparticles enhance the ZnO band-edge emission by charge transfer when the MgO spacer layer is absent.

Photoluminescence of ZnO nanocrystals embedded in BaF2 matrices by magnetron sputtering

This paper describes ZnO nanocrystals embedded in BaF2 matrices by the magnetron sputtering method in an attempt to use fluoride as a shell layer to embed ZnO nanocrystals core. BaF2 is a wide-band gap material, and can confine carriers in the ZnO films. As a result, the exciton emission intensity should be enhanced. The sample was annealed at 773 K, and X-ray diffraction (XRD) results showed that ZnO nanocrystals with wurtzite structure were embedded in BaF2 matrices. Raman-scattering spectra also confirmed the formation of ZnO nanoparticles. Abnormal longitudinal-optical (LO) phonon-dominant multiphonon Raman scattering was observed in the sample. Room-temperature photoluminescence (PL) spectra showed an ultraviolet emission peak at 374 nm. The origin of the ultraviolet emission is discussed here with the help of temperature-dependent PL spectra. The ultraviolet emission band was a mixture of free exciton and bound exciton recombination observed in the low temperature PL spectra (at 77 K). Abnormal temperature dependence of ultraviolet near-band-edge emission-integrated intensity of the sample was observed. The band tail state was observed in the absorption spectra, illustrating that the impurity-related defects were caused by the shell of the BaF2 grain layer. For comparison, ZnO films on BaF2 substrates were also fabricated by the magnetron sputtering method, and the same measurement methods were used.

Impact of famine during pregnancy and infancy on health in adulthood

The objectives of the present study are (i) To examine the association between fetal nutritional status and overweight and obesity in adulthood and (ii) to provide the evidence for formulating a strategy to prevent low birth weight. With data from the 2002 Nationwide Nutrition and Health Survey, the body mass indexes (BMIs) of rural residents born during the famine years of 1959, 1960, 1961 were compared with those born in 1964. The health consequence of famine on the adulthood BMI was evident in women; the mean BMIs of the women were significantly higher in the three famine groups than that in the control group born in 1964 (P < 0.01). After adjustment for regional differences within China, the prevalences of overweight in women were significantly higher in the three famine groups (P < 0.01) and of obesity in the 1959 and 1960 groups. (P < 0.01). Such differences were not found in men. The higher risks of overweight and obesity in women were caused by malnutrition in fetal life. A strategy for preventing low birth weight should be formulated by the government to prevent chronic disease in adulthood.

Structural, optical, and magnetic properties of Mn-doped ZnO thin film

The Zn(1-x)Mn(x)O (x = 0, 0.16, and 0.25) thin films were grown on fused quartz substrates by reactive magnetron cosputtering. X-ray-diffraction measurement revealed that all the films were single phase and had wurtzite structure with c-axis orientation. As Mn concentration increased in the Zn(1-x)Mn(x)O films, the c-axis lattice constant and band-gap energy increased gradually. In Raman-scattering studies, an additional Mn-related vibration mode appeared at 520 cm(-1). E(2H) phonon line of Zn(1-x)Mn(x)O alloy was broadened asymmetrically and redshifted as a result of microscopic structural disorder induced by Mn(2+) random substitution. The Zn(0.84)Mn(0.16)O film exhibited a ferromagnetic characteristic with a Curie temperature of approximately 62 K. However, with increasing Mn concentration to 25 at. %, ferromagnetism disappeared due to the enhanced antiferromagnetic superexchange interactions between neighboring Mn(2+) ions.

Surface-enhanced Raman spectroscopy using silver-coated porous glass-ceramic substrates

Surface-enhanced Raman scattering (SERS) has been studied using a silver-coated porous glass-ceramic material as a new type of substrate. The porous glass-ceramic is in the CaO-TiO2-P2O5 system prepared by controlled crystallization and subsequent chemical leaching of the dense glass-ceramic, leaving a solid skeleton with pores ranging in size from 50 nm to submicrometer. Silver was coated on the surface of the porous glass-ceramic by radio frequency (RF) sputtering or e-beam evaporation in vacuum. SERS spectra of excellent quality were obtained from several dyes and carboxylic acid molecules, including rhodamine 6G, crystal violet, isonicotinic acid, and benzoic acid, using this new substrate. This new substrate showed a good compatibility with these molecules. The porous glass ceramic with a nanometer-structured surface accommodated both test molecules and silver film. The absorbed molecules were therefore better interfaced with silver for surface-enhanced Raman scattering.

N,O-Dilithio-2-(N-methylamino)ethanol: An Intramolecular Mixed Aggregate

Density functional theory and infrared spectroscopy were used to determine the structure of N,O-dilithio-2-(N-methylamino)ethanol, a mixed intramolecular aggregate. The calculations indicated that the cyclic form of this compound is more stable than the open form, and that conclusion is consistent with the infrared spectra. The solid-state spectra showed lower Li-N and Li-O vibrational frequencies than were calculated for the gas phase, which is consistent with coordination of lithium to electronegative atoms on adjacent molecules in the solid state.

Structure, Bonding, and Solvation of Dilithiodiamines

Computational methods were used to determine the structure of dilithiodiamines and the effects of solvation by ethereal solvents. Solvation was examined by the use of microsolvation with explicit dimethyl ether or THF ligands and by the combined use of microsolvation and the IEFPCM continuum solvent model. It was determined that each of the compounds studied exists exclusively as a bridged intramolecular dimer, both in the gas phase and in solution. Thermodynamic properties were calculated at 200 and 298 K to estimate the effect of temperature on the cyclization energies. Infrared spectroscopy was used to confirm the proposed intramolecular dimer structures.

Validation of biomarkers in humans exposed to benzene: urine metabolites

BACKGROUND

The present study was conducted among Chinese workers employed in glue- and shoe-making factories who had an average daily personal benzene exposure of 31+/-26 ppm (mean+/-SD). The metabolites monitored were S-phenylmercapturic acid (S-PMA), trans, trans-muconic acid (t,t-MA), hydroquinone (HQ), catechol (CAT), 1,2, 4-trihydroxybenzene (benzene triol, BT), and phenol.

METHODS

S-PMA, t,t-MA, HQ, CAT, and BT were quantified by HPLC-tandem mass spectrometry. Phenol was measured by GC-MS.

RESULTS

Levels of benzene metabolites (except BT) measured in urine samples collected from exposed workers at the end of workshift were significantly higher than those measured in unexposed subjects (P < 0.0001). The large increases in urinary metabolites from before to after work strongly correlated with benzene exposure. Concentrations of these metabolites in urine samples collected from exposed workers before work were also significantly higher than those from unexposed subjects. The half-lives of S-PMA, t,t-MA, HQ, CAT, and phenol were estimated from a time course study to be 12.8, 13.7, 12.7, 15.0, and 16.3 h, respectively.

CONCLUSIONS

All metabolites, except BT, are good markers for benzene exposure at the observed levels; however, due to their high background, HQ, CAT, and phenol may not distinguish unexposed subjects from workers exposed to benzene at low ambient levels. S-PMA and t,t-MA are the most sensitive markers for low level benzene exposure.

Self-aggregation of DNA oligomers with XGG trinucleotide repeats: kinetic and atomic force microscopy measurements

Turbidity measurements via absorbance monitoring at 320 nm were employed to obtain autocatalytic-like kinetic profiles of K+-induced aggregate formation of d(XGG)4 and some related oligomers, where X = A, C, G, and T. At least 1 M KCl is needed to observe the turbidity-measurable aggregation at pH 8, and the relative propensity for aggregate formation is shown to follow the order d(GGG)4 > d(AGG)4 approximately d(TGG)4 >> d(CGG)4. The presence of Mg2+ greatly facilitates and dramatically reduces the amount of K+ required to initiate aggregation and significantly enhances the thermal stabilities of the aggregates. Replacement of K+ by Na+ fails to induce a similar phenomenon. The Psi-type CD characteristics of aggregates are strongly dependent on the sequence and ionic conditions. Despite their ease of aggregate formation, oligomers with AGG trinucleotide repeats fail to exhibit Psi-CD formation. The propensity for aggregation is greatly affected by the chain length, with oligomers of four repeats being most facile. Appending X base at the 3' end of d(GGXGGXGGXGG) appears to provide a greater hindrance to aggregation than at the 5' end. Atomic force microscopic images support some of these findings and reveal the morphologies of these aggregates. The presence of MgCl2 in solutions appears to considerably elongate the K+-induced aggregates.

[Expression of IL-1 mRNA and its correlation with astrocytes and NOS-positive neurons in rat spinal cord following sciatic nerve injury]

OBJECTIVE

To study expression of Interleukin 1 (IL-1) and its correlation with astrocytes and nitric-oxide synthase (NOS)-positive neurons in rat spinal cord following sciatic nerve transection.

METHODS

Using RT-PCR and immunohistochemistry methods.

RESULTS

The experiments showed that IL-1 expression appeared with a low frequency at 3 days after the axontomy, while it could be markedly detectable on post-lesioned day 7 and 14. In normal controls and the spinal fragments without being involved in the injury, no signal of IL-1 mRNA expression was detected with the same condition. At 7 days after nerve injury, the lesioned side of spinal cord began to show strong glial fibrillary acidic protein (GFAP) immunoreactive astrocytes and induction of NOS in the motoneurons that are normally NOS-negative. Up to 21 days after operation, GFAP staining showed star-shaped astrocytes closely resembling the typical appearance of fibrous astrocytes and GFAP-immunoreactive profiles were often seen surrounding NOS-positive neurons. Analysis of the time course of IL-1 mRNA expression, appearance of NOS-positive neurons and changes of reactive astrocytes suggested a close relationship between them.

CONCLUSIONS

IL-1, NO might function as important mediators between injured motoneurons and astrocytes.