Rice Husk Silica Liquid Enhances Autophagy and Reduces Overactive Immune Responses via TLR-7 Signaling in Lupus-Prone Models.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder characterized by widespread inflammation and multi-organ damage. Toll-like receptor 7 (TLR-7) and autophagy have been implicated in SLE pathogenesis. Rice husk silica liquid (RHSL) has shown potential for modulating inflammatory responses, but its effects on SLE have not been thoroughly investigated. This study aims to evaluate the impact of RHSL on immune responses and autophagy in cell culture experiments, focusing on its effects on TLR-7 signaling, cytokine production, and autophagy modulation. RAW264.7 cells and human peripheral blood mononuclear cells (PBMCs) from healthy donors and SLE patients were used. Cells were stimulated with LPS or TLR-7 agonists and treated with RHSL. Cell viability was assessed, and cytokine levels (TNF-α and IL-6) were measured by ELISA. Autophagy-related proteins (LC3II, ATG5-ATG12) were analyzed by Western blotting. The effect of autophagy inhibition was studied using 3-methyladenine (3-MA). A concentration of 100 µg/mL RHSL did not affect cell viability but significantly reduced the TNF-α production in TLR-7 agonist-stimulated RAW264.7 cells (compared to TLR-7 alone, 3.41 ± 0.54 vs. 6.72 ± 0.07 folds) and PBMCs (compared to TLR-7 alone, 0.97 ± 0.19 vs. 1.40 ± 0.33 folds). RHSL enhanced autophagy, as evidenced by increased LC3II (4.35 ± 1.08 folds) and ATG5-ATG12 (7.07 ± 1.30 folds) conjugation in both RAW264.7 cells and SLE patient-derived PBMCs. The reduction in TNF-α production by RHSL was attenuated by 3-MA, indicating that autophagy plays a role in this process. RHSL also inhibited the translocation of phosphorylated NF-κB into the nucleus, suggesting a mechanism for its anti-inflammatory effects. RHSL exhibits potential as an immunomodulatory agent in SLE by enhancing autophagy and modulating TLR-7 signaling pathways. These findings suggest that RHSL could offer therapeutic benefits for managing inflammatory responses in SLE and warrant further investigation into its clinical applications.

Genetic diversity, biofilm formation, and Vancomycin resistance of clinical Clostridium innocuum isolates.

BACKGROUND: Clostridium innocuum, previously considered a commensal microbe, is a spore-forming anaerobic bacterium. C. innocuum displays inherent resistance to vancomycin and is associated with extra-intestinal infections, antibiotic-associated diarrhea, and inflammatory bowel disease. This study seeks to establish a multilocus sequence typing (MLST) scheme to explore the correlation between C. innocuum genotyping and its potential pathogenic phenotypes. METHODS: Fifty-two C. innocuum isolates from Linkou Chang Gung Memorial Hospital (CGMH) in Taiwan and 60 sequence-available C. innocuum isolates from the National Center for Biotechnolgy Information Genome Database were included. The concentrated sequence of housekeeping genes in C. innocuum was determined by amplicon sequencing and used for MLST and phylogenetic analyses. The biofilm production activity of the C. innocuum isolates was determined by crystal violet staining. RESULTS: Of the 112 C. innocuum isolates, 58 sequence types were identified. Maximum likelihood estimation categorized 52 CGMH isolates into two phylogenetic clades. These isolates were found to be biofilm producers, with isolates in clade I exhibiting significantly higher biofilm production than isolates in clade II. The sub-inhibitory concentration of vancomycin seemed to minimally influence biofilm production by C. innocuum isolates. Nevertheless, C. innocuum embedded in the biofilm structure demonstrated resistance to vancomycin treatments at a concentration greater than 256 µg/mL. CONCLUSIONS: This study suggests that a specific genetic clade of C. innocuum produces a substantial amount of biofilm. Furthermore, this phenotype assists C. innocuum in resisting high concentrations of vancomycin, which may potentially play undefined roles in C. innocuum pathogenesis.

Plasma cytokines pattern as a prognostic marker for esophageal squamous cell carcinoma via unsupervised clustering analyses.

INTRODUCTION: Cytokines such as Tumor necrosis factor-alpha (TNF-α), Interleukin 6 (IL6), Interferon-gamma (IFN-γ), Interleukin 17-alpha (IL17-α), and Interleukin 33 (IL33), play critical roles in immune responses, and may impact cancer prognosis in future. However, few studies have simultaneously explored the prognostic impact of these cytokines for cancer. In this study, we aim to apply the unsupervised clustering analysis to approach the correlation between the expression of these cytokines and the subsequent prognosis of patients with esophageal squamous cell carcinoma. METHODS: A robust clustering algorithm was used, the Gaussian Mixture Method, through the mclust R package to group patients based on the expression of their cytokines in plasma or tumors. The 324 NTU patients were grouped into 4 clusters, and the 179 GSE53625 patients were grouped into 3 clusters based on expression in plasma and tumors, respectively. Five- and three-year overall survival (OS) and progression free survival (PFS) curves of each cluster were compared. Univariate and multivariate Cox regression analyses were also performed. RESULTS: We successfully distinguished the multimodal distribution of cytokines through GMM clustering, and discovered the relationship between cytokines and clinical outcomes. We observed that NTU-G3 and NTU-G4 subgroups showed most variation in 5-, 3-year OS, and 5-, 3-year PFS with NTU-G3 being associated with poorer prognosis compared to NTU-G4 (P = 0.016, 0.0052, 0.0575, and 0.0168, respectively). NTU-G3 was characterized with higher TNF-α (median = 3.855, N=78) and lower IL33 (median = 0.000, N = 78), while NTU-G4 showed lower TNF-α (median = 1.76, N = 51) and higher IL33 (median = 1.070, N = 51). The difference was statistically significant for TNF-α and IL33, with P = 0.002 and P <0.0001, respectively. A multivariate Cox-regression analysis revealed that GMM clustering and T/N stage were independent factors for prognosis, suggesting that the prognosis might be dependent on these cytokines. CONCLUSIONS: Our data suggest that expression patterns of IL33 and TNF-α in plasma might serve as a convenient marker to predict the prognosis of ESCC in the future.

Neonatal gut microbiota profile and the association with retinopathy of prematurity in preterm infants.

BACKGROUND: To explore the role of gut microbiota in preterm infants at high risk of developing retinopathy of prematurity (ROP). METHODS: Preterm infants with gestational age (GA) < 32 weeks and/or birth weight (BW) < 1500 g born between 2020 and 2021 were prospectively enrolled. Their faecal samples were collected and analysed at different postnatal ages of life using 16S rRNA gene sequencing on the Miseq platform. The main outcome measures were the microbial diversity, taxonomy, relative abundance, bacterial predicted functional analysis, and their associations with different ROP groups. Subgroup analyses were performed by matching their GA and BW across different ROP groups. RESULTS: A total of 268 stool samples were collected from 110 preterm infants, including 13 with type 1 ROP, 44 with type 2 or mild ROP, and 53 without ROP. Type 1 ROP showed no significant difference in microbial diversity up to 8 postnatal weeks (p = 0.057), while type 2 and no ROP groups displayed increased diversity (p = 0.0015 and p = 0.049, respectively). Bifidobacterium genera was notably less abundant in type 1 ROP group at first postnatal week (p = 0.022) and remained low in subsequent weeks. Predicted functional analysis revealed enriched pathways in membrane transport, carbohydrate metabolism, amino acid metabolism, and replication and repair. CONCLUSIONS: Reduced gut microbial diversity may be associated with ROP development in high-risk preterm infants. Further research is needed to comprehend how early-life Bifidobacterium reduction affects metabolism and how targeting microbiome may help for ROP prevention and management.

Long-Term Immunogenicity Study of an Aluminum Phosphate-Adjuvanted Inactivated Enterovirus A71 Vaccine in Children: An Extension to a Phase 2 Study.

Enterovirus A71 (EV-A71) causes hand, foot, and mouth disease in infants and children with potential for fatal complications such as encephalitis and acute flaccid myelitis. This study examined the long-term immunity conferred by EV71vac, an inactivated EV-A71 vaccine adjuvanted with aluminum phosphate, in children from the age of 2 months to <6 years, for up to 5 years after the first immunization. A total of 227 participants between 2 months and <6 years of age who had previously received either EV71vac or placebo in the phase two clinical study were enrolled. Subjects were divided into age groups: 2 years to <6 years (Group 2b), 6 months to <2 years (Group 2c), and 2 months to <6 months (Group 2d). At Year 5, the neutralizing antibody titers against the B4 subgenotype remained high at 621.38 to 978.20, 841.40 to 1159.93, and 477.71 to 745.07 for Groups 2b, 2c, and 2d, respectively. Cross-neutralizing titers at Year 5 remained high against B5 and C4a subgenotypes, respectively. No long-term safety issues were reported. Our study provides novel insights into the long-term immunity conferred by EV71vac in children aged from two months to six years, particularly in those who received EV71vac between two and six months of age.

Evaluation of Vaccine Strategies among Healthcare Workers during COVID-19 Omicron Outbreak in Taiwan.

BACKGROUND/OBJECTIVES: This study aimed to assess the reactogenicity and immunogenicity of various SARS-CoV-2 vaccines and compare their protective effects against COVID-19 among healthcare workers (HCWs) during the Omicron outbreak in Taiwan. METHODS: Conducted from March 2021 to July 2023, this prospective observational study included healthy HCWs without prior COVID-19 immunization. Participants chose between adenovirus-vectored (AstraZeneca), mRNA (Moderna, BioNTech-Pfizer), and protein-based (Medigen, Novavax) vaccines. Blood samples were taken at multiple points to measure neutralizing antibody (nAb) titers, and adverse events (AEs) were recorded via questionnaires. RESULTS: Of 710 HCWs, 668 (94.1%) completed three doses, and 290 (40.8%) received a fourth dose during the Omicron outbreak. AEs were more common with AstraZeneca and Moderna vaccines, while Medigen caused fewer AEs. Initial nAb titers were highest with Moderna but waned over time regardless of the vaccine. Booster doses significantly increased nAb titers, with the highest levels observed in Moderna BA1 recipients. The fourth dose significantly reduced COVID-19 incidence, with Moderna BA1 being the most effective. CONCLUSIONS: Regular booster doses, especially with mRNA and adjuvant-protein vaccines, effectively enhance nAb levels and reduce infection rates, providing critical protection for frontline HCWs during variant outbreaks.

RAGE participates in the intracellular transport of Campylobacter jejuni cytolethal distending toxin.

BACKGROUND: Cytolethal distending toxin (CDT) belongs to the genotoxin family and is closely related to Campylobacter jejuni-associated gastroenteritis. We recently reported that CDT triggers the danger-associated molecular pattern (DAMP) signaling to exert deleterious effects on host cells. However, how CDT traffics in cells and the mechanism of CDT intoxication remain to be elucidated. METHODS: Recombinant CDT subunits (CdtA, CdtB, and CdtC) were purified, and their activity was characterized in gastrointestinal cells. Molecular approaches and image tracking were employed to analyze the delivery of CDT in host cells. RESULTS: In this study, we found that CDT interacts with the receptor of advanced glycation end products (RAGE) and high mobility group box 1 (HMGB1) to enter the cells. Our results further showed that CdtB transport in cells through the dynamin-dependent endocytic pathway and lysosome is involved in this process. Conversely, blockage of RAGE signaling resulted in a reduction in CDT-arrested cell cycles, indicating that RAGE is involved in CDT intracellular transport and its subsequent pathogenesis. CONCLUSION: Our results demonstrate that RAGE is important for CDT trafficking in the cells. These findings expand our understanding of important issues related to host cell intoxication by C. jejuni CDT.

Benzaldehyde stimulates autophagy via the sonic hedgehog signaling pathway in mouse brain astrocytes after treatment with Angiostrongylus cantonensis excretory-secretory products.

Autophagy is a vital cellular process responsible for digesting various cytoplasmic organelles. This process plays a crucial role in maintaining cell survival and homeostasis, especially under conditions that cause nutrient deficiency, cellular damage, and oxidative stress. Neuroangiostrongyliasis is an infection caused by the parasitic nematode Angiostrongylus cantonensis and is considered as an emerging disease in many parts of the world. However, effective therapeutic strategies for neuroangiostrongyliasis still need to be further developed. In this study, we investigated the effects of benzaldehyde treatment on autophagy and sonic hedgehog (Shh) signaling in A. cantonensis-infected mice and its mechanisms. First, we found autophagosome generation in the central nervous system after A. cantonensis infection. Next, benzaldehyde combined with albendazole treatment reduced eosinophilic meningitis and upregulated the expression of Shh signaling- and autophagy-related molecules in A. cantonensis-infected mouse brains. In vitro experiments demonstrated that benzaldehyde could induce autophagy via the Shh signaling pathway in A. cantonensis excretory-secretory products (ESPs)-treated mouse astrocytes. Finally, benzaldehyde treatment also decreased lipid droplet accumulation and increased cholesterol production by activating the Shh pathway after ESPs treatment. In conclusion, these findings suggested that benzaldehyde treatment could alleviate brain damage by stimulating autophagy generation through the Shh signaling pathway.

Worldwide SARS-CoV-2 Omicron variant infection: Emerging sub-variants and future vaccination perspectives.

The coronavirus disease 2019 (COVID-19) pandemic has sparked widespread concern globally, particularly with the Omicron variant and its sub-lineages emerging as the predominant cause of infection for nearly two years. Taiwan's successful containment of COVID-19, underscored by broad vaccine coverage, the utilization of anti-viral therapeutics, and timely response strategies, has resulted in reduced excess mortality. Moreover, there is a crucial need for a phased exit strategy, balancing efforts to curtail disease transmission with the mitigation of socioeconomic impacts from rigorous measures. In this review, we examined the evolution and the epidemiological landscape of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sub-variants in Taiwan as well as other countries of the world. We also critically evaluated the effectiveness of COVID-19 vaccines against various SARS-CoV-2 variants. Additionally, we addressed the advantages of heterologous immunization strategies, fluctuations in neutralizing antibody titers, and complexities in establishing protective correlates among swiftly mutating viral variants.

Advanced Glycation End-Products Acting as Immunomodulators for Chronic Inflammation, Inflammaging and Carcinogenesis in Patients with Diabetes and Immune-Related Diseases.

Increased production of advanced glycation end products (AGEs) among reducing sugars (glucose, fructose, galactose, or ribose) and amino acids/proteins via non-enzymatic Maillard reaction can be found in lifestyle-related disease (LSRD), metabolic syndrome (MetS), and obesity and immune-related diseases. Increased serum levels of AGEs may induce aging, diabetic complications, cardiovascular diseases (CVD), neurodegenerative diseases (NDD), cancer, and inflamm-aging (inflammation with immunosenescence). The Maillard reaction can also occur among reducing sugars and lipoproteins or DNAs to alter their structure and induce immunogenicity/genotoxicity for carcinogenesis. AGEs, as danger-associated molecular pattern molecules (DAMPs), operate via binding to receptor for AGE (RAGE) or other scavenger receptors on cell surface to activate PI3K-Akt-, P38-MAPK-, ERK1/2-JNK-, and MyD88-induced NF-κB signaling pathways to mediate various pathological effects. Recently, the concept of "inflamm-aging" became more defined, and we have unveiled some interesting findings in relation to it. The purpose of the present review is to dissect the potential molecular basis of inflamm-aging in patients with diabetes and immune-mediated diseases caused by different AGEs.

Comparative Efficacy of Fecal Microbiota Transplantation in Treating Refractory or Recurrent Clostridioides difficile Infection among Patients with and without Inflammatory Bowel Disease: A Retrospective Cohort Study.

Clostridioides difficile infection (CDI) worsens inflammatory bowel disease (IBD) prognosis. While fecal microbiota transplantation (FMT) is effective for refractory or recurrent CDI (rrCDI), comparative success rates between IBD and non-IBD patients are scarce. This study addresses this gap. A retrospective cohort study was conducted at Chang Gung Memorial Hospital from April 2019 to October 2023. Patients receiving FMT for rrCDI were categorized into IBD and non-IBD groups. Baseline characteristics and outcomes were compared at one month and one year, with successful FMT defined as the resolution of diarrhea without CDI recurrence. The study included 88 patients: 30 with IBD and 58 without IBD. The IBD group was younger, with fewer comorbidities. Success rates at one month were similar between groups (IBD: 80.0% vs. non-IBD: 78.9%, p = 0.908), as were negative toxin tests (IBD: 83.3% vs. non-IBD: 63.8%, p = 0.174). One-year success rates (IBD: 70.0% vs. non-IBD: 67.6%, p = 0.857) and eradication rates (IBD: 94.4% vs. non-IBD: 73.9%, p = 0.112) were also similar. Poor bowel preparation predicted FMT failure at one month (OR = 0.23, p = 0.019). No safety issues were reported. FMT is a safe, effective treatment for rrCDI, demonstrating similar success rates in patients with and without IBD.

Substitutions in the nonactive site of the passenger domain on the activity of Haemophilus influenzae immunoglobulin A1 protease.

Immunoglobulin A1 (IgA1) protease is a critical virulence factor of Haemophilus influenzae that facilitates bacterial mucosal infection. This study investigates the effect of iga gene polymorphism on the enzymatic activity of H. influenzae IgA1 protease. The IgA1 protease activity was examined in the H. influenzae Rd KW20 strain and 51 isolates. Genetic variations in iga and deduced amino acid substitutions affecting IgA1 protease activity were assessed. Machine learning tools and functional complementation assays were used to analyze the effects of identified substitutions on the stability and activity of IgA1 protease, respectively. All 51 isolates exhibited similar iga expression levels. No igaB expression was detected. According to comparisons with the reference Rd KW20 strain, four substitutions in the protease domain, 26 in the nonprotease passenger domain, and two in the ß-barrel domain were associated with the change in IgA1 protease activity. No substitutions in the catalytic site of IgA1 protease were observed. Logistic regression, receiver operating characteristic curves, Venn diagrams, and protein stability analyses revealed that the substitutions Asn352Lys, Pro353Ala, Lys356Asn, Gln916Lys, and Gly917Ser, which were located in the nonactive site of the passenger domain, were associated with decreases in IgA1 protease activity and stability, whereas Asn914Lys was associated with an increase in these events. Functional complementation assays revealed that the Asn914Lys substitution increased IgA1 protease activity in the Rd KW20 strain. This study identified substitutions in the nonactive site of the passenger domain that affect both the activity and stability of H. influenzae IgA1 protease.

Directed Self-Assembly of Polystyrene-Block-Polyhedral Oligomeric Silsesquioxane Monolayer by Nano-Trench for Nanopatterning.

This work pioneers to combine fast self-assembly of polyhedral oligomeric silsesquioxanes (POSS) nanocage-based giant surfactants with high etching contrast and directed self-assembly for reliable long-range lateral order to create well-aligned sub-10 nm line nanopatterns via reactive ion etching (RIE). Polystyrene-block-oligo(dimethylsiloxane) substituted POSS (PS-b-oDMS7POSS) with seven oligo(dimethylsiloxane) at the corners of the POSS nanocage and one polystyrene (PS) tail is designed and synthesized as a giant surfactant with self-assembly behaviors like block copolymer (BCP). In contrast to BCP, oDMS7POSS gives a volume-persistent "nanoatom" particle with higher mobility for fast self-assembly and higher segregation strength with PS for smaller feature size. By taking advantage of directed self-assembly using nano-trench fabricated by electron beam lithography, well-ordered nanostructured monolayer with well-aligned parallel oDMS7POSS cylinders can be formed by confined self-assembly within the nano-trench. With the optimization of the RIE treatment using O2 as an etchant, the high etching contrast from the oDMS7POSS and PS gives the formation of well-defined line nanopatterns with sub-10 nm critical dimension that can serve as a mask for pattern transfer in lithography. These results demonstrate a cost-effective approach for nanopatterning by utilizing a creatively designed giant surfactant with sub-10 nm feature size and excellent etching contrast for modern lithographic applications.

Antimicrobial efficacy and amino acid substitutions associated with susceptibility to the tellurium compound AS101 against Haemophilus influenzae and Haemophilus parainfluenzae.

The tellurite toxicity in Haemophilus influenzae and H. parainfluenzae remains unclear. To understand the potential of tellurite as a therapeutic option for these bacteria, we investigated the antimicrobial efficacy of AS101, a tellurium compound, against H. influenzae and H. parainfluenzae and the molecular basis of their differences in AS101 susceptibility. Through broth microdilution, we examined the minimum inhibitory concentration (MIC) of AS101 in 51 H. influenzae and 28 H. parainfluenzae isolates. Whole-genome sequencing was performed on the H. influenzae isolates to identify genetic variations associated with AS101 susceptibility. The MICs of AS101 were ≦ 4, 16-32, and ≧ 64 µg/mL in 9 (17.6%), 12 (23.5%), and 30 (58.8%) H. influenzae isolates, respectively, whereas ≦ 0.5 µg/mL in all H. parainfluenzae isolates, including multidrug-resistant isolates. Time-killing kinetic assay and scanning electron microscopy revealed the in vitro bactericidal activity of AS101 against H. parainfluenzae. Forty variations in nine tellurite resistance-related genes were associated with AS101 susceptibility. Logistic regression, receiver operator characteristic curve analysis, Venn diagram, and protein sequence alignment indicated that Val195Ile substitution in TerC, Ser93Gly in Gor (glutathione reductase), Pro44Ala/Ala50Pro in NapB (nitrate reductase), Val307Leu in TehA (tellurite resistance protein), Cys105Arg in CysK (cysteine synthase), and Thr364Ser in Csd (Cysteine desulfurase) were strongly associated with reduced AS101 susceptibility, whereas Ser155Pro in TehA with increased AS101 susceptibility. In conclusions, the antimicrobial efficacy of AS101 is high against H. parainfluenzae but low against H. influenzae. Genetic variations and corresponding protein changes relevant to AS101 non-susceptibility in H. influenzae were identified.

Sequential Self-Assembly of Polystyrene-block-Polydimethylsiloxane for 3D Nanopatterning via Solvent Annealing.

This study aims to develop a strategy for the fabrication of multilayer nanopatterns through sequential self-assembly of lamella-forming polystyrene-block-polydimethylsiloxane (PS-b-PDMS) block copolymer (BCP) from solvent annealing. By simply tuning the solvent selectivity, a variety of self-assembled BCP thin-film morphologies, including hexagonal perforated lamellae (HPL), parallel cylinders, and spheres, can be obtained from single-composition PS-b-PDMS. By taking advantage of reactive ion etching (RIE), topographic SiO2 monoliths with well-ordered arrays of hexagonally packed holes, parallel lines, and hexagonally packed dots can be formed. Subsequently, hole-on-dot and line-on-hole hierarchical textures can be created through a layer-by-layer process with RIE treatment as evidenced experimentally and confirmed theoretically. The results demonstrated the feasibility of creating three-dimensional (3D) nanopatterning from the sequential self-assembly of single-composition PS-b-PDMS via solvent annealing, providing an appealing process for nano-MEMS manufacturing based on BCP lithography.

Risk of rituximab-induced hepatitis B flare after antiviral discontinuation in rheumatic patients with chronic hepatitis B virus.

OBJECTVES: Among immunosuppressants, rituximab is most strongly associated with the risk of hepatitis B virus (HBV) reactivation in chronic HBV individuals. Current guidelines recommending antiviral prophylaxis for these patients on rituximab are predominantly based on studies in oncology. However, limited data existed for the precise risk of HBV flares, effectiveness and optimal duration of antiviral prophylaxis in rituximab-treated rheumatic patients, whose immune status and treatment regimen differ significantly from those of oncology patients. Therefore, we aimed to assess the incidence and clinical outcome of HBV reactivation in HBsAg-positive patients receiving rituximab for various autoimmune diseases who discontinue the antiviral agents. METHODS: A retrospective analysis was performed on 95 hepatitis B surface antigen (HBsAg)-positive patients treated with rituximab for autoimmune diseases in a single centre in Taiwan. HBV related hepatitis, defined as alanine aminotransferase (ALT) more than 3 times of baseline level and concurrent HBV reactivation, after anti-viral discontinuation, was the primary endpoint. Factors associated with HBV hepatitis flare and off-antiviral hepatitis flare were also analysed. RESULTS: With nucleos(t)ide analogues (NA) prophylaxis, no hepatitis flares occurred. However, without prophylaxis, 59% had flare (24.5 per 100 person-years) and 8% experienced liver decompensation. Concurrent steroid use was a dose-dependent risk factor for flare. After NA discontinuation, rituximab "retreatment" led to flares in 75% of cases and liver decompensation in 63% of patients. Stopping NAs within one-year post-rituximab, even without further rituximab treatment, resulted in a 38% flare rate. CONCLUSIONS: This study offers the direct evidence for the necessity of universal antiviral prophylaxis in rheumatic patients with chronic HBV receiving rituximab. After NA discontinuation, rituximab "retreatment" led to even higher flare rate and worse outcome. Patients who completed rituximab treatment should also keep antiviral agents for at least one more year to prevent hepatitis flare.

Agalactosyl IgG induces liver fibrogenesis via Fc gamma receptor 3a on human hepatic stellate cells.

The relevance of aberrant serum IgG N-glycosylation in liver fibrosis has been identified; however, its causal effect remains unclear. Because hepatic stellate cells (HSCs) contribute substantially to liver fibrosis, we investigated whether and through which mechanisms IgG N-glycosylation affects the fibrogenic properties of HSCs. Analysis of serum IgG1 N-glycome from 151 patients with chronic hepatitis B or liver cirrhosis revealed a positive correlation between Ishak fibrosis grading and IgG1 with agalactosyl N-glycoforms on the crystallizable fragment (Fc). Fc gamma receptor (FcγR) IIIa was observed in cultured human HSCs and HSCs in human liver tissues, and levels of FcγRIIIa in HSCs correlated with the severity of liver fibrosis. Additionally, agalactosyl IgG treatment caused HSCs to have a fibroblast-like morphology, enhanced migration and invasion capabilities, and enhanced expression of the FcγRIIIa downstream tyrosine-protein kinase SYK. Furthermore, agalactosyl IgG treatment increased fibrogenic factors in HSCs, including transforming growth factor (TGF)-ß1, total collagen, platelet-derived growth factor subunit B and its receptors, pro-collagen I-α1, α-smooth muscle actin, and matrix metalloproteinase 9. These effects were more pronounced in HSCs that stably expressed FCGR3A and were reduced in FCGR3A knockout cells. Agalactosyl IgG and TGF-ß1 each increased FCGR3A in HSCs. Furthermore, serum TGF-ß1 concentrations in patients were positively correlated with agalactosyl IgG1 levels and liver fibrosis severity, indicating a positive feedback loop involving agalactosyl IgG, HSC-FcγRIIIa, and TGF-ß1. In conclusion, agalactosyl IgG promotes fibrogenic characteristics in HSCs through FcγRIIIa. © 2024 The Pathological Society of Great Britain and Ireland.

Membranome-based identification of amino acid substitution in Haemophilus influenzae multidrug efflux pump HmrM for reduced chloramphenicol susceptibility.

A decreased chloramphenicol susceptibility in Haemophilus influenzae is commonly caused by the activity of chloramphenicol acetyltransferases (CATs). However, the involvement of membrane proteins in chloramphenicol susceptibility in H. influenzae remains unclear. In this study, chloramphenicol susceptibility testing, whole-genome sequencing, and analyses of membrane-related genes were performed in 51 H. influenzae isolates. Functional complementation assays and structure-based protein analyses were conducted to assess the effect of proteins with sequence substitutions on the minimum inhibitory concentration (MIC) of chloramphenicol in CAT-negative H. influenzae isolates. Six isolates were resistant to chloramphenicol and positive for type A-2 CATs. Of these isolates, A3256 had a similar level of CAT activity but a higher chloramphenicol MIC relative to the other resistant isolates; it also had 163 specific variations in 58 membrane genes. Regarding the CAT-negative isolates, logistic regression and receiver operator characteristic curve analyses revealed that 48T > G (Asn16Lys), 85 C > T (Leu29Phe), and 88 C > A (Leu30Ile) in HI_0898 (emrA), and 86T > G (Phe29Cys) and 141T > A (Ser47Arg) in HI_1177 (artM) were associated with enhanced chloramphenicol susceptibility, whereas 997G > A (Val333Ile) in HI_1612 (hmrM) was associated with reduced chloramphenicol susceptibility. Furthermore, the chloramphenicol MIC was lower in the CAT-negative isolates with EmrA-Leu29Phe/Leu30Ile or ArtM-Ser47Arg substitution and higher in those with HmrM-Val333Ile substitution, relative to their counterparts. The Val333Ile substitution was associated with enhanced HmrM protein stability and flexibility and increased chloramphenicol MICs in CAT-negative H. influenzae isolates. In conclusion, the substitution in H. influenzae multidrug efflux pump HmrM associated with reduced chloramphenicol susceptibility was characterised.

Clinical characteristics of SARS-CoV-2 Omicron BA.2 infection and its impact on pediatric emergency care in northern Taiwan.

BACKGROUND: The SARS-CoV-2 Omicron BA.2 outbreak started in Taiwan in April 2022. The pandemic posed a challenge to pediatric emergency departments (PEDs) because of increased PED visits and diverse clinical presentations. METHODS: We analyzed the clinical characteristics and impact of the Omicron BA.2 pandemic in patients who visited our PED from April 2022 to July 2022. The data from the Alpha variant pandemic during the same period in 2021 were compared with these findings. RESULTS: Overall, 10,878 children were enrolled, and 7047 (64.8%) children were positive for SARS-CoV-2 infection. They had a mean ± SD age of 5.3 ± 4.1 years. The rates of patients with Pediatric Taiwan Triage and Acuity Scale (Ped-TTAS) level 1 (most urgent) (12.3%) and level 2 (27.6%) increased. More children were triaged as most urgent during the Omicron BA.2 pandemic than during the Alpha variant pandemic (p < 0.001). Patients with SARS-CoV-2 infection were likely to present with high fever, croup, dyspnea, febrile seizures, headache, dizziness, and myalgia (all p < 0.001). Four hundred and eleven (5.8%) patients were admitted; 25 (0.4%) patients needed intensive care, including 11 (44.0%) with encephalopathy or encephalitis. Three (0.04%) patients died due to fulminant encephalitis, encephalitis with septic shock, and respiratory failure. CONCLUSIONS: The number of PED visits and the Ped-TTAS level of disease severity significantly increased during the SARS-CoV-2 Omicron BA.2 outbreak. The most common symptom was fever, and high fever was more common in patients with SARS-CoV-2 Omicron BA.2 infection. The rates of patients with croup and febrile seizures also increased.

Functional Analysis of the Major Pilin Proteins of Type IV Pili in Streptococcus sanguinis CGMH010.

The pil gene cluster for Type IV pilus (Tfp) biosynthesis is commonly present and highly conserved in Streptococcus sanguinis. Nevertheless, Tfp-mediated twitching motility is less common among strains, and the factors determining twitching activity are not fully understood. Here, we analyzed the functions of three major pilin proteins (PilA1, PilA2, and PilA3) in the assembly and activity of Tfp in motile S. sanguinis CGMH010. Using various recombinant pilA deletion strains, we found that Tfp composed of different PilA proteins varied morphologically and functionally. Among the three PilA proteins, PilA1 was most critical in the assembly of twitching-active Tfp, and recombinant strains expressing motility generated more structured biofilms under constant shearing forces compared to the non-motile recombinant strains. Although PilA1 and PilA3 shared 94% identity, PilA3 could not compensate for the loss of PilA1, suggesting that the nature of PilA proteins plays an essential role in twitching activity. The single deletion of individual pilA genes had little effect on the invasion of host endothelia by S. sanguinis CGMH010. In contrast, the deletion of all three pilA genes or pilT, encoding the retraction ATPase, abolished Tfp-mediated invasion. Tfp- and PilT-dependent invasion were also detected in the non-motile S. sanguinis SK36, and thus, the retraction of Tfp, but not active twitching, was found to be essential for invasion.