The chromatin remodeler ERCC6 and the histone chaperone NAP1 are involved in apurinic/apyrimidinic endonuclease-mediated DNA repair.

During base excision repair (BER), the apurinic or apyrimidinic (AP) site serves as an intermediate product following base excision. In plants, APE-redox protein (ARP) represents the major AP site of cleavage activity. Despite the well-established understanding that the nucleosomal structure acts as a barrier to various DNA-templated processes, the regulatory mechanisms underlying BER at the chromatin level remain elusive, especially in plants. In this study, we identified plant chromatin remodeler Excision Repair Cross-Complementing protein group 6 (ERCC6) and histone chaperone Nucleosome Assembly Protein 1 (NAP1) as interacting proteins with ARP. The catalytic ATPase domain of ERCC6 facilitates its interaction with both ARP and NAP1. Additionally, ERCC6 and NAP1 synergistically contribute to nucleosome sliding and exposure of hindered endonuclease cleavage sites. Loss-of-function mutations in Arabidopsis (Arabidopsis thaliana) ERCC6 or NAP1 resulted in arp-dependent plant hypersensitivity to 5-fluorouracil, a toxic agent inducing BER, and the accumulation of AP sites. Furthermore, similar protein interactions are also found in yeast cells, suggesting a conserved recruitment mechanism employed by the AP endonuclease to overcome chromatin barriers during BER progression.

Spatial-Temporal Mapping Reveals the Golgi as the Major Processing Site for the Pathogenic Swedish APP Mutation: Familial APP Mutant Shifts the Major APP Processing Site.

Alzheimer's disease is associated with increased levels of amyloid beta (Aß) generated by sequential intracellular cleavage of amyloid precursor protein (APP) by membrane-bound secretases. However, the spatial and temporal APP cleavage events along the trafficking pathways are poorly defined. Here, we use the Retention Using Selective Hooks (RUSH) to compare in real time the anterograde trafficking and temporal cleavage events of wild-type APP (APPwt) with the pathogenic Swedish APP (APPswe) and the disease-protective Icelandic APP (APPice). The analyses revealed differences in the trafficking profiles and processing between APPwt and the APP familial mutations. While APPwt was predominantly processed by the ß-secretase, BACE1, following Golgi transport to the early endosomes, the transit of APPswe through the Golgi was prolonged and associated with enhanced amyloidogenic APP processing and Aß secretion. A 20°C block in cargo exit from the Golgi confirmed ß- and γ-secretase processing of APPswe in the Golgi. Inhibition of the ß-secretase, BACE1, restored APPswe anterograde trafficking profile to that of APPwt. APPice was transported rapidly through the Golgi to the early endosomes with low levels of Aß production. This study has revealed different intracellular locations for the preferential cleavage of APPwt and APPswe and Aß production, and the Golgi as the major processing site for APPswe, findings relevant to understand the molecular basis of Alzheimer's disease.

Abscisic acid root-to-shoot translocation by transporter AtABCG25 mediates stomatal movements in Arabidopsis.

The phytohormone abscisic acid (ABA) plays a central role in regulating stomatal movements under drought conditions. The root-derived peptide CLAVATA3/EMBRYO SURROUNDING REGION-RELATED 25 (CLE25) moves from the root to shoot for activating ABA biosynthesis under drought conditions. However, the root-to-shoot translocation of root-derived ABA and its regulation of stomatal movements in the shoot remain to be clarified. Here, we reveal that the ABA transporter ATP-binding cassette subfamily G member 25 (AtABCG25) mediates root-to-shoot translocation of ABA and ABA-glucosyl ester (ABA-GE) in Arabidopsis (Arabidopsis thaliana). Isotope-labeled ABA tracer experiments and hormone quantification in xylem sap showed that the root-to-shoot translocation of ABA and ABA-GE was substantially impaired in the atabcg25 mutant under nondrought and drought conditions. However, the contents of ABA and ABA-GE in the leaves were lower in the atabcg25 mutant than in the wild type (WT) under nondrought but similar under drought conditions. Consistently, the stomatal closure was suppressed in the atabcg25 mutant under nondrought but not under drought conditions. The transporter activity assays showed that AtABCG25 directly exported ABA and ABA-GE in planta and in yeast (Saccharomyces cerevisiae) cells. Thus, we proposed a working model in which root-derived ABA transported by AtABCG25 via xylem mediates stomatal movements in the shoot under nondrought conditions but might exhibit little effect on stomatal movements under drought conditions. These findings extend the functions of AtABCG25 and provide insights into the long-distance translocation of ABA and its role in stomatal movements.

Quasi-Solid-State All-V2O5 Battery.

Solid-state symmetrical battery represents a promising paradigm for future battery technology. However, its development is hindered by the deficiency of high-performance bipolar electrodes and compatible solid electrolytes. Herein, a quasi-solid-state all-V2O5 battery constructed by a binder-free carbon fabric-V2O5 nanowires@graphene (CVOG) bipolar electrode and a softly cross-linked polyethylene oxide-based solid polymer electrolyte (SPE) is reported. The synergetic effect of nano-structuring of V2O5, hierarchical conductive network, and graphene wrapping endows the CVOG electrode with boosted reaction kinetics and suppressed vanadium dissolution. The cathodic and anodic reactions of CVOG are decoupled by electrochemical analysis, conceiving the feasibility of constructing all-V2O5 full battery. In manifesting the solid-state all-V2O5 battery, the robust and elastic SPE exhibits high ionic conductivity, tight/self-adaptable electrolyte-electrode contact, and a low charge-transfer barrier. The resultant solid-state full battery exhibits a high reversible capacity of 158 mAh g-1 at 0.1 C, good capacity retention of over 61% from 0.1 C to 2 C, and remarkable cycling stability of 77% capacity retention after 1000 cycles at 1 C, which surpass other solid-state symmetrical batteries. Hence, this work provides a practice of high-performance solid-state batteries with symmetrical configuration and is constructive for next-generation battery technology.

Characterization and optimization of 5´ untranslated region containing poly-adenine tracts in Kluyveromyces marxianus using machine-learning model.

BACKGROUND: The 5´ untranslated region (5´ UTR) plays a key role in regulating translation efficiency and mRNA stability, making it a favored target in genetic engineering and synthetic biology. A common feature found in the 5´ UTR is the poly-adenine (poly(A)) tract. However, the effect of 5´ UTR poly(A) on protein production remains controversial. Machine-learning models are powerful tools for explaining the complex contributions of features, but models incorporating features of 5´ UTR poly(A) are currently lacking. Thus, our goal is to construct such a model, using natural 5´ UTRs from Kluyveromyces marxianus, a promising cell factory for producing heterologous proteins. RESULTS: We constructed a mini-library consisting of 207 5´ UTRs harboring poly(A) and 34 5´ UTRs without poly(A) from K. marxianus. The effects of each 5´ UTR on the production of a GFP reporter were evaluated individually in vivo, and the resulting protein abundance spanned an approximately 450-fold range throughout. The data were used to train a multi-layer perceptron neural network (MLP-NN) model that incorporated the length and position of poly(A) as features. The model exhibited good performance in predicting protein abundance (average R2 = 0.7290). The model suggests that the length of poly(A) is negatively correlated with protein production, whereas poly(A) located between 10 and 30 nt upstream of the start codon (AUG) exhibits a weak positive effect on protein abundance. Using the model as guidance, the deletion or reduction of poly(A) upstream of 30 nt preceding AUG tended to improve the production of GFP and a feruloyl esterase. Deletions of poly(A) showed inconsistent effects on mRNA levels, suggesting that poly(A) represses protein production either with or without reducing mRNA levels. CONCLUSION: The effects of poly(A) on protein production depend on its length and position. Integrating poly(A) features into machine-learning models improves simulation accuracy. Deleting or reducing poly(A) upstream of 30 nt preceding AUG tends to enhance protein production. This optimization strategy can be applied to enhance the yield of K. marxianus and other microbial cell factories.

Machine learning models for abstract screening task - A systematic literature review application for health economics and outcome research.

OBJECTIVE: Systematic literature reviews (SLRs) are critical for life-science research. However, the manual selection and retrieval of relevant publications can be a time-consuming process. This study aims to (1) develop two disease-specific annotated corpora, one for human papillomavirus (HPV) associated diseases and the other for pneumococcal-associated pediatric diseases (PAPD), and (2) optimize machine- and deep-learning models to facilitate automation of the SLR abstract screening. METHODS: This study constructed two disease-specific SLR screening corpora for HPV and PAPD, which contained citation metadata and corresponding abstracts. Performance was evaluated using precision, recall, accuracy, and F1-score of multiple combinations of machine- and deep-learning algorithms and features such as keywords and MeSH terms. RESULTS AND CONCLUSIONS: The HPV corpus contained 1697 entries, with 538 relevant and 1159 irrelevant articles. The PAPD corpus included 2865 entries, with 711 relevant and 2154 irrelevant articles. Adding additional features beyond title and abstract improved the performance (measured in Accuracy) of machine learning models by 3% for HPV corpus and 2% for PAPD corpus. Transformer-based deep learning models that consistently outperformed conventional machine learning algorithms, highlighting the strength of domain-specific pre-trained language models for SLR abstract screening. This study provides a foundation for the development of more intelligent SLR systems.

Role of hydrocolloid dressing in preventing face pressure ulcers from non-invasive ventilation and facilitating postoperative wound healing in maxillofacial surgery: A meta-analysis.

Facial pressure ulcers from non-invasive ventilation (NIV) and challenges in wound healing post-maxillofacial surgery are significant concerns in clinical care. This meta-analysis aimed to evaluate the effectiveness of hydrocolloid dressings in these contexts. From a pool of 1135 articles, 8 studies met the inclusion criteria. Hydrocolloid dressings demonstrated a significant reduction in facial pressure ulcers for NIV patients, with lower REEDA scores 1-week postapplication (standardized mean difference [SMD] = -16.7, 95% confidence interval [CI]: -24.26 to -9.15, p < 0.01). In maxillofacial surgery, patients treated with hydrocolloid dressings exhibited improved wound healing and reduced scar formation, evidenced by lower Manchester Scar Scale scores 3 months post-surgery (SMD = -15.46, 95% CI: -20.28 to -10.64, p < 0.01). These findings suggest that hydrocolloid dressings are effective in both preventing NIV-related facial pressure ulcers and enhancing wound healing in maxillofacial surgery.

Low risk of erectile dysfunction after nontransecting bulbar urethroplasty for urethral stricture: a systematic review and meta-analysis.

BACKGROUND: Sexual function after urethroplasty may be a concern for patients, but there are still some controversies regarding the consequences of nontransecting bulbar urethroplasty (ntBU) in terms of erectile dysfunction (ED). AIM: This meta-analysis aimed to compare the efficacy and safety of ntBU with that of transecting bulbar urethroplasty (tBU). METHODS: The PubMed, Web of Science, Cochrane, and Embase databases were searched and reviewed up to October 31, 2022. Quality evaluation was performed using the Newcastle-Ottawa scale system and Cochrane tools for the nonrandomized and randomized studies, respectively. Baseline characteristics, preoperative information, and postoperative outcomes were collected. OUTCOMES: Outcomes included success rate, ED, overall complication, and maximum urinary flow. RESULTS: Thirteen studies comprising 1683 patients met the inclusion criteria, with 596 and 1087 patients undergoing ntBU and tBU, respectively. The results revealed that compared with the tBU group, the patients who underwent ntBU had a significantly lower incidence of ED, while there were no significant differences in the other perioperative outcomes. In subgroup analysis, the nontransecting anastomotic urethroplasty group had a lower incidence of ED than excision and primary anastomosis, and other perioperative outcomes were similar between the 2 groups. CLINICAL IMPLICATIONS: The results of the study may help clinicians choose procedures that protect sexual function in the treatment of urethral stricture. STRENGTHS AND LIMITATIONS: The strength of this study is that it is, to our knowledge, the first meta-analysis to evaluate the efficacy and safety of ntBU. A limitation is that most of the included studies were retrospective cohort studies. CONCLUSION: ntBU preserves the high efficacy of its transecting counterpart while reducing postoperative ED.

18F-Labeled o­aminopyridyl alkynyl radioligands targeting colony-stimulating factor 1 receptor for neuroinflammation imaging.

We report the design, synthesis and evaluation of five o­aminopyridyl alkynyl derivatives as colony-stimulating factor 1 receptor (CSF-1R) ligands. Compounds 4 and 5 with the fluoroethoxy group at the meta- or para-position of the phenyl ring possessed nanomolar inhibitory potency against CSF-1R with IC50 values of 7.6 nM and 2.3 nM, respectively. Radioligands [18F]4 and [18F]5 were obtained in radiochemical yields of 17.2 ± 5.3% (n = 5, decay-corrected) and 14.0 ± 4.3% (n = 4, decay-corrected), with radiochemical purity of > 99% and molar activity of 9-12 GBq/µmol (n = 5) and 6-8 GBq/µmol (n = 4), respectively. In biodistribution studies, radioligands [18F]4 and [18F]5 showed moderate brain uptake in male ICR mice with 1.52 ± 0.15 and 0.91 ± 0.07% ID/g, respectively, at 15 min. Metabolic stability studies in mouse brain revealed that [18F]4 exhibited high stability while [18F]5 suffered from low stability. Higher accumulation of [18F]4 in the brain of lipopolysaccharide (LPS)-treated mice was observed, and further pretreatment of BLZ945 or CPPC led to remarkable reduction, indicating specific binding of [18F]4 to CSF-1R.

Embedded ultra-high stability flexible transparent conductive films based on exfoliated graphene-silver nanowires-colorless polyimide.

Transparent conductive films with high stability were prepared by embedding silver nanowires in colorless polyimide and adding a protective layer of exfoliated graphene. The films exhibit great light transmission and conductivity with a sheet resistance of 22 Ω sq-1at transmittance of 83%. Due to its special embedded structure, the conductive layer can withstand several peeling experiments without falling off. In addition, the most outstanding advantage is the ultra-high stability of the films, including high mechanical robustness, strong chemical corrosion resistance and high operating voltage capacity. The organic light-emitting diode devices prepared based on this transparent conductive electrode exhibit comparable efficiency to indium tin oxide (ITO) based devices, withC.E.max= 2.78 cd A-1,P-1.E.max= 1.89 lm W-1,EQEmax= 0.89%. Moreover, the efficiencies were even higher than that of ITO devices when the operating voltage of the device exceeds 5 V. The above performances show that the transparent conductive electrode based on this structure has high potential for application in organic electronic devices.

Establishment of an animal model of ejaculatory duct obstruction.

This study aimed to establish animal models with different degrees of ejaculatory duct obstruction. Forty-eight male rats aged 14-15 weeks were randomly divided into three groups (n = 16): control, complete ejaculatory duct obstruction (tied around the lower seminal vesicle gland and ductus deferens with a 2-0 silk ligature), and partial ejaculatory duct obstruction (padded with a wire guide). Mortality, complications, seminal vesicle morphology and histopathology were compared in the three groups at 4 and 8 weeks postoperatively. In the complete ejaculatory duct obstruction group, seminal vesicle weight decreased gradually with increased obstruction time compared with those of the control group (p < 0.05); moreover, stone-like material was occasionally observed. In the partial ejaculatory duct obstruction group, there was an increase followed by a decrease in seminal vesicle weight in the postoperative period compared with that of the control group (p < 0.05). Histopathological lesions of seminal vesicles were observed in the complete and partial ejaculatory duct obstruction groups (8 weeks postoperatively). We successfully established animal models of complete and partial ejaculatory duct obstruction, which provide an easy-to-use tool for studying seminal vesicle changes after ejaculatory duct obstruction.

SDFnT-Based Parameter Estimation for OFDM Radar Systems with Intercarrier Interference.

The orthogonal frequency division multiplexing (OFDM) radar suffers from severe performance degradation in range-velocity estimation in high mobility scenarios. In this paper, a novel intercarrier interference (ICI)-free parameter estimation method for OFDM radar is proposed. By employing a scale discrete Fresnel transform (SDFnT), the OFDM radar signals are converted to the scale Fresnel domain, and the orthogonality of subcarriers can be recovered with the optimal scale factor. Furthermore, due to the compatibility of the SDFnT and the discrete Fourier Transform (DFT), the proposed method has low computational complexity and high feasibility for OFDM radar implementation. Simulation results show that the proposed SDFnT-based scheme effectively eliminates the ICI effect for single and multiple targets and achieves high accuracy delay-Doppler estimation for OFDM radar systems in circumstances of high velocity and low SNR with consistency and robustness.

An Anti-Turbulence Self-Alignment Method for SINS under Unknown Latitude Conditions.

For the alignment problem of strapdown inertial navigation system (SINS) under the complex environment of unknown latitude, angular oscillation interference, and line interference, the ant colony simulated annealing algorithm of gravity vector optimization is proposed to obtain the gravity apparent motion vector optimization equation, and the polynomial fitting method is proposed to simultaneously perform latitude estimation and self-alignment in combination with the alignment principle of SINS. Simulations and experiments show that the proposed method has more robust anti-interference capability than the traditional interference-based alignment method, the latitude estimation accuracy is improved by six times, the self-alignment yaw angle error RMSE value after obtaining the latitude is within 0.7°, and the roll angle and pitch angle error values are within 0.1°.

microRNAs: Key Players in Plant Response to Metal Toxicity.

Environmental metal pollution is a common problem threatening sustainable and safe crop production. Heavy metals (HMs) cause toxicity by targeting key molecules and life processes in plant cells. Plants counteract excess metals in the environment by enhancing defense responses, such as metal chelation, isolation to vacuoles, regulating metal intake through transporters, and strengthening antioxidant mechanisms. In recent years, microRNAs (miRNAs), as a small non-coding RNA, have become the central regulator of a variety of abiotic stresses, including HMs. With the introduction of the latest technologies such as next-generation sequencing (NGS), more and more miRNAs have been widely recognized in several plants due to their diverse roles. Metal-regulated miRNAs and their target genes are part of a complex regulatory network. Known miRNAs coordinate plant responses to metal stress through antioxidant functions, root growth, hormone signals, transcription factors (TF), and metal transporters. This article reviews the research progress of miRNAs in the stress response of plants to the accumulation of HMs, such as Cu, Cd, Hg, Cr, and Al, and the toxicity of heavy metal ions.

Serum neurofilament light chain and glial fibrillary acidic protein in AQP4-IgG-seropositive neuromyelitis optica spectrum disorders and multiple sclerosis: A cohort study.

We investigated the serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) levels in a cohort of Chinese patients with neuromyelitis optica spectrum disorders (NMOSD) and multiple sclerosis (MS) in relation to clinical disease course and treatment. sNfL and sGFAP levels were determined by ultrasensitive single molecule array (Simoa) assay in patients with NMOSD (n = 102) and MS (n = 98) and healthy controls (HCs; n = 84). Notably, 13 patients with NMOSD and 27 patients with MS were enrolled in the 1-year follow-up cohort. Levels were compared with data such as clinical course, disease duration, Expanded Disability Status Scale (EDSS) score, and lesions on MRI. Higher levels of sNfL and sGFAP were found in subjects with NMOSD and MS than in HCs (sNfL, median 12.11, 17.5 vs. 8.88 pg/ml, p < .05; sGFAP, median 130.2, 160.4 vs. 80.01 pg/ml, p < .05). Moreover, sNfL levels were higher in the relapse phase of MS than in the relapse phase of NMOSD (30.02 vs. 14.57 pg/ml, p < .05); sGFAP levels were higher in the remission phase of MS than in the remission phase of NMOSD (159.8 vs. 124.5 pg/ml, p < .01). A higher sGFAP/sNfL quotient at relapse differentiated NMOSD from MS. Multivariate analyses indicated that sGFAP levels were associated with the EDSS score in NMOSD (p < .05). At the 1-year follow-up, sNfL and sGFAP levels were both decreased in NMOSD patients in remission, while only sNfL levels were decreased in MS patients in remission. sGFAP and sNfL are potential blood biomarkers for diagnosing and monitoring NMOSD and MS.

Whole-exome sequencing reveals the major genetic factors contributing to neuromyelitis optica spectrum disorder in Chinese patients with aquaporin 4-IgG seropositivity.

BACKGROUND AND OBJECTIVE: Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease. Although genetic factors are involved in its pathogenesis, limited evidence is available in this area. The aim of the present study was to identify the major genetic factors contributing to NMOSD in Chinese patients with aquaporin 4 (AQP4)-IgG seropositivity. METHODS: Whole-exome sequencing (WES) was performed on 228 Chinese NMOSD patients seropositive for AQP4-IgG and 1400 healthy controls in Guangzhou, South China. Human leukocyte antigen (HLA) sequencing was also utilized. Genotype model and haplotype, gene burden, and enrichment analyses were conducted. RESULTS: A significant region of the HLA composition is on chromosome 6, and great variation was observed in DQB1, DQA2 and DQA1. HLA sequencing confirmed that the most significant allele was HLA-DQB1*05:02 (p < 0.01, odds ratio [OR] 3.73). The genotype model analysis revealed that HLA-DQB1*05:02 was significantly associated with NMOSD in the additive effect model and dominant effect model (p < 0.05). The proportion of haplotype "HLA-DQB1*05:02-DRB1*15:01" was significantly greater in the NMOSD patients than the controls, at 8.42% and 1.23%, respectively (p < 0.001, OR 7.39). The gene burden analysis demonstrated that loss-of-function mutations in NOP16 were more common in the NMOSD patients (11.84%) than the controls (5.71%; p < 0.001, OR 2.22). The IgG1-G390R variant was significantly more common in NMOSD, and the rate of the T allele was 0.605 in patients and 0.345 in the controls (p < 0.01, OR 2.92). The enrichment analysis indicated that most of the genetic factors were mainly correlated with nervous and immune processes. CONCLUSIONS: Human leukocyte antigen is highly correlated with NMOSD. NOP16 and IgG1-G390R play important roles in disease susceptibility.

Male patients with neuromyelitis optica spectrum disorders: different clinical characteristics and worse steroid treatment response.

BACKGROUND: Clinical data on male neuromyelitis optica spectrum (NMO) patients remain limited to date. OBJECTIVE: To analyze clinical characteristics, therapeutic responses, and outcomes in Chinese male NMOSD patients. METHODS: We retrospectively assessed clinical, demographic, treatment, and outcome data of male patients with NMOSD. RESULTS: We identified 52 male patients among 471 NMOSD patients. Male patients had more frequent optic neuritis (ON) attacks and less frequent myelitis than female patients. No-remission rates of high-dose intravenous steroid therapy were higher in male patients than in female patients. CONCLUSION: Male NMOSD patients had different clinical characteristics and worse response to high-dose intravenous steroid therapy than female patients.

Simplification in the Acquisition and Analysis of Fluorescence Decays Acquired with Polarized Emission for Time-Resolved Fluorescence Anisotropy Measurements.

This study introduces a global fluorescence decay analysis that substantially simplifies the acquisition and analysis of time-resolved fluorescence decays acquired with a vertically polarized excitation and vertically (IVV(t)) and horizontally (IVH(t)) polarized emission for time-resolved fluorescence anisotropy (TRFA) measurements. TRFA measurements were conducted whereby the IVV(t) and IVH(t) fluorescence decays of a series of oligoquinolines labeled at one end with an oligo(phenylenevinylene) dye (OPV-Qn with n = 4, 7, 17, 24, 33) were acquired according to the standard protocol that is currently accepted in the scientific literature which involves toggling the emission polarizer before fitting linear combinations of the IVV(t) and IVH(t) decays or acquiring the IVV(t) and IVH(t) decays with static polarizers before fitting them globally. The rotational time (ϕ) and initial anisotropy (r0) retrieved from these analyses were identical within experimental error regardless of whether the decays were acquired with toggling or static polarizers and fitted according to the standard protocol or globally. These experimental results were further supported by retrieving the parameters used to generate mono-, bi-, and tri-exponential TRFAs from the global analysis of simulated IVV(t) and IVH(t) fluorescence decays which were found to match perfectly the values that were inputted. Together, these experiments and simulations demonstrated that the parameters describing any type of TRFA can be extracted directly from the analysis of the IVV(t) and IVH(t) fluorescence decays acquired with a standard time-resolved fluorometer, a substantial simplification compared to the protocols currently in place to determine the TRFA.

Myelin oligodendrocyte glycoprotein-associated disorders are associated with HLA subtypes in a Chinese paediatric-onset cohort.

OBJECTIVE: Myelin oligodendrocyte glycoprotein-associated disorders (MOGADs) are a rare new neurological autoimmune disease with unclear pathogenesis. Since a linkage of the disease to the human leucocyte antigen (HLA) has not been shown, we here investigated whether MOGAD is associated with the HLA locus. METHODS: HLA genotypes of 95 patients with MOGADs, assessed between 2016 and 2018 from three academic centres, were compared with 481 healthy Chinese Han individuals. Patients with MOGADs included 51 paediatric-onset and 44 adult-onset cases. All patients were seropositive for IgG targeting the myelin oligodendrocyte glycoprotein (MOG). RESULTS: Paediatric-onset MOGAD was associated with the DQB1*05:02-DRB1*16:02 alleles (OR=2.43; OR=3.28) or haplotype (OR=2.84) of HLA class II genes. The prevalence of these genotypes in patients with paediatric-onset MOGAD was significantly higher than healthy controls (padj=0.0154; padj=0.0221; padj=0.0331). By contrast, adult-onset MOGAD was not associated with any HLA genotype. Clinically, patients with the DQB1*05:02-DRB1*16:02 haplotype exhibited significantly higher expanded disability status scale scores at onset (p=0.004) and were more likely to undergo a disease relapse (p=0.030). HLA-peptide binding prediction algorithms and computational docking analysis provided supporting evidence for the close relationship between the MOG peptide subunit and DQB1*05:02 allele. In vitro results indicated that site-specific mutations of the predicted target sequence reduced the antigen-antibody binding, especially in the paediatric-onset group with DQB1*05:02 allele. CONCLUSIONS: This study demonstrates a possible association between specific HLA class II alleles and paediatric-onset MOGAD, providing evidence for the conjecture that different aetiology and pathogenesis likely underlie paediatric-onset and adult-onset cases of MOGAD.

Impurity profiling of alfentanil hydrochloride by liquid chromatography/quadrupole time-of-flight high-resolution mass spectrometric techniques for drug enforcement.

RATIONALE: Fentanyl and its analogues play important roles in the hospital and clinic setting as anesthetics. However, illicitly manufactured fentanyl as well as the new psychoactive substances (NPS) account for 30% of all deaths in the United States. Since fentanyl derivatives and NPS are designed to produce similar effects, their related substances are similar or even have the same active groups. A comprehensive analysis of the related substances of alfentanil hydrochloride can provide a basis for the identification and supervision of fentanyl derivatives and NPS. METHODS: A liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (LC/QTOF-MS/MS) method was developed for the separation and characterization of related substances in alfentanil hydrochloride. Degradation studies were conducted according to the ICH-prescribed stress conditions. The compounds were identified mainly through positive electrospray ionization QTOF high-resolution mass spectrometric measurements of the accurate masses of the precursor and product ions and their calculated elemental compositions. Their formation mechanisms were also discussed. RESULTS: Seventeen related substances were detected in alfentanil hydrochloride and its stressed samples. Among them, nine were process-related substances and the other eight were degradation products. The stress study results demonstrated that alfentanil hydrochloride was unstable under acid, alkaline, and oxidative stress conditions, while relatively stable under dry photolytic and thermal stress conditions. Alfentanil hydrochloride was most susceptible for degradation at the N-phenylpropanamide and piperidine sites. CONCLUSIONS: Process-related alfentanil hydrochloride compounds are useful for determination of synthetic routes and entangling of fentanyl analogues. The stress study results can provide a sound scientific basis for the waste water monitoring of alfentanil. These results are important for routine quality control in the manufacturing and storage of alfentanil hydrochloride, as well as for drug enforcement of fentanyl and its analogues.