Norditerpenoid alkaloids from Aconitum refractum var. circinatum as autophagy inducers.

A total of twenty-two diterpenoid alkaloids, including ten unprecedented ones, namely refractines C-L, were isolated from the roots of Aconitum refractum (Finet et Gagnep.) Hand.-Mazz. Refractine C was the first example of a natural diterpenoid alkaloid wherein C-19 is linked to N position by an oxaziridine ring. Refractine L was a rare glycosidic diterpenoid alkaloid with fructofuranoside. Most of the isolated compounds obtained from a previous study were screened for their anti-inflammatory and myocardial protective activities. The autophagy-inducing effects of some of these compounds on RAW 264.7 cells were evaluated by assessing the expression of microtubule-associated protein 1 light chain 3 (LC3-II/LC3-I). Results revealed that some compounds exerted varying levels of inhibitory effects on the proliferative activity of RAW 264.7 cells.

Short-term postoperative bacteriobilia or fungibilia in liver transplantation patients with donation after circulatory death allografts associated with a longer hospital stay: A single-center retrospective observational study in China.

BACKGROUND: Normal bile is sterile. Studies have shown that cholangitis after liver transplantation (LT) was associated with a relatively poor prognosis. It remains unclear whether the bacteriobilia or fungibilia impact the patient outcomes in LT recipients, especially with donation after circulatory death (DCD) allografts, which was correlated with a higher risk of allograft failure. METHODS: This retrospective study included 139 LT recipients of DCD grafts from 2019 to 2021. All patients were divided into two groups according to the presence or absence of bacteriobilia or fungibilia. The prevalence and microbial spectrum of postoperative bacteriobilia or fungibilia and its possible association with outcomes, especially hospital stay were analyzed. RESULTS: Totally 135 and 171 organisms were isolated at weeks 1 and 2, respectively. Among all patients included in this analysis, 83 (59.7%) developed bacteriobilia or fungibilia within 2 weeks post-transplantation. The occurrence of bacteriobilia or fungibilia (ß = 7.43, 95% CI: 0.02 to 14.82, P = 0.049), particularly the detection of Pseudomonas (ß = 18.84, 95% CI: 6.51 to 31.07, P = 0.003) within 2 weeks post-transplantation was associated with a longer hospital stay. However, it did not affect the graft and patient survival. CONCLUSIONS: The occurrence of bacteriobilia or fungibilia, particularly Pseudomonas within 2 weeks post-transplantation, could influence the recovery of liver function and was associated with prolonged hospital stay but not the graft and patient survival.

Mated-Atom Nanozymes with Efficient Assisted NAD+ Replenishment for Skin Regeneration.

Excessive accumulation of reduced nicotinamide adenine dinucleotide (NADH) within biological organisms is closely associated with many diseases. It remains a challenge to efficiently convert superfluous and detrimental NADH to NAD+. NADH oxidase (NOX) is a crucial oxidoreductase that catalyzes the oxidation of NADH to NAD+. Herein, M1M2 (Mi=V/Mn/Fe/Co/Cu/Mo/Rh/Ru/Pd, i = 1 or 2) mated-atom nanozymes (MANs) are designed by mimicking natural enzymes with polymetallic active centers. Excitingly, RhCo MAN possesses excellent and sustainable NOX-like activity, with Km-NADH (16.11 µM) being lower than that of NOX-mimics reported so far. Thus, RhCo MAN can significantly promote the regeneration of NAD+ and regulate macrophage polarization toward the M2 phenotype through down-regulation of TLR4 expression, which may help to recover skin regeneration. However, RhRu MAN with peroxidase-like activity and RhMn MAN with superoxide dismutase-like activity exhibit little modulating effects on eczema. This work provides a new strategy to inhibit skin inflammation and promote skin regeneration.

High-sensitivity fiber optic graphene resonant accelerometer.

This study proposes a high-sensitivity resonant graphene accelerometer based on a pressure-induced sensing mechanism. The accelerometer design encompasses an optical fiber and a vacuum-sealed graphene resonator affixed to a silicon sensitive film, incorporating a proof mass. This indirect sensing mechanism effectively mitigates the vibration mode aliasing of graphene and the proof mass while ensuring a minimal energy loss in the operating resonator. The mechanical vibration of graphene is excited and detected through an all-fiber optical system. Notably, the proposed sensor demonstrates a sensitivity of 34.3 kHz/g within the range of 0-3.5 g, which is eight times higher than comparable accelerometers utilizing a proof mass on a graphene membrane. This work exhibits a novel, to the best of our knowledge, approach to an acceleration measurement using 2D resonators, exhibiting distinct advantages in terms of compact size and heightened sensitivity.

Stability of tryptophan-containing LOs in flaxseed oil and their response towards γ-tocopherol.

Linusorbs (LOs), significantly influence oil quality and sensory properties of flaxseed oil. Trp-containing LOs exhibit distinct oxidative behavior when γ-tocopherol (γ-T) is present. Polar fractions of crude flaxseed oil were stripped via silica absorption, and reintroduced (LO and γ-T) separately into the oil matrix to investigate their interaction during storage. Compared with crude oil, LOs account for 18.49% reduction of p-anisidine value, while LOs with γ-T contributed to most of the endogenous antioxidant effect in crude oil. γ-T was found to suppress oxidation of Trp-containing LO at early stage (Met form), while facilitate oxidation while at their mid-stage (MetO form, Methionine sulfoxide). In vitro oxidation shows that CLD more likely cleaved into peptide fragments, while few products retain intact ring structures. LC-MS/MS analysis and silicon simulation revealed proximity between MetO and Trp residues, facilitating inter- or intra-molecular reactions and ring structure rupture. Remarkably, the presence of γ-T facilitate these phenomena.

[The experience on the construction of the cluster prevention and control system for COVID-19 infection in designated hospitals during the period of "Category B infectious disease treated as Category A"].

The COVID-19 epidemic has spread to the whole world for three years and has had a serious impact on human life, health and economic activities. China's epidemic prevention and control has gone through the following stages: emergency unconventional stage, emergency normalization stage, and the transitional stage from the emergency normalization to the "Category B infectious disease treated as Category B" normalization, and achieved a major and decisive victory. The designated hospitals for prevention and control of COVID-19 epidemic in Tianjin has successfully completed its tasks in all stages of epidemic prevention and control, and has accumulated valuable experience. This article summarizes the experience of constructing a hospital infection prevention and control system during the "Category B infectious disease treated as Category A" period in designated hospital. The experience is summarized as the "Cluster" hospital infection prevention and control system, namely "three rings" outside, middle and inside, "three districts" of green, orange and red, "three things" before, during and after the event, "two-day pre-purification" and "two-director system", and "one zone" management. In emergency situations, we adopt a simplified version of the cluster hospital infection prevention and control system. In emergency situations, a simplified version of the "Cluster" hospital infection prevention and control system can be adopted. This system has the following characteristics: firstly, the system emphasizes the characteristics of "cluster" and the overall management of key measures to avoid any shortcomings. The second, it emphasizes the transformation of infection control concepts to maximize the safety of medical services through infection control. The third, it emphasizes the optimization of the process. The prevention and control measures should be comprehensive and focused, while also preventing excessive use. The measures emphasize the use of the least resources to achieve the best infection control effect. The fourth, it emphasizes the quality control work of infection control, pays attention to the importance of the process, and advocates the concept of "system slimming, process fattening". Fifthly, it emphasizes that the future development depends on artificial intelligence, in order to improve the quality and efficiency of prevention and control to the greatest extent. Sixth, hospitals need to strengthen continuous training and retraining. We utilize diverse training methods, including artificial intelligence, to ensure that infection control policies and procedures are simple. We have established an evaluation and feedback mechanism to ensure that medical personnel are in an emergency state at all times.

A Girl with PRRT2 Mutation Presenting with Benign Familial Infantile Seizures Followed by Autistic Regression.

Benign familial infantile seizure (BFIS) is an autosomal dominant infantile-onset epilepsy syndrome with a typically benign prognosis. It is commonly associated with heterozygous mutations of the PRRT2 gene located on chromosome 16p11.2. The frameshift heterozygous mutation (c.649dupC, p.Arg217Profs∗8) in PRRT2 is responsible for the majority of BFIS cases. In this report, we present a rare case of a girl with a confirmed clinical and genetic diagnosis of BFIS due to a frameshift heterozygous mutation in PRRT2 (c.649dupC). She exhibited typical neurodevelopment until 15 months of age, followed by an unexpected severe autistic regression. In addition to BFIS, PRRT2 mutations are also associated with paroxysmal kinesigenic dyskinesia (PKD) and infantile convulsions and paroxysmal choreoathetosis (ICCA), indicating a complex genotype-phenotype heterogeneity in PRRT2 mutations. This clinical observation highlights the possibility that BFIS patients with PRRT2 mutations may not always have a benign neurodevelopmental prognosis, emphasizing the need for long-term clinical follow-up.

Why Do We Not Wear Masks Anymore during the COVID-19 Wave? Vaccination Precludes the Adoption of Personal Non-Pharmaceutical Interventions: A Quantitative Study of Taiwanese Residents.

Background and Objectives: This study examined whether the decline in people's adoption of personal NPIs (e.g., mask wearing) results from the preclusion by vaccination. This study also incorporates the concepts of risk perception and the risk-as-feelings model to elucidate the possible mechanisms behind this preclusion. Materials and Methods: Two cross-sectional surveys (N = 462 in Survey 1 and N = 505 in Survey 2) were administered before and during the first outbreak of COVID-19 in Taiwan. The survey items were designed to measure participants' perceived severity of COVID-19, worry about COVID-19, intention to adopt personal NPIs, and attitudes toward COVID-19 vaccines. Utilizing the risk perception framework, we conducted multigroup SEM (Structural Equation Modeling) to construct the optimal structural model for both samples. Results and Conclusions: The multigroup SEM results showed that worry (i.e., the emotional component of risk perception) fully mediates the influence of the perceived severity of COVID-19 (i.e., the cognitive component of risk perception) on the intention to adopt NPIs in both surveys [z = 4.03, p < 0.001 for Survey 1 and z = 2.49, p < 0.050 for Survey 2]. Before the outbreak (i.e., Survey 1), people's attitudes toward COVID-19 vaccines showed no significant association with their worry about COVID-19 [z = 0.66, p = 0.508]. However, in Survey 2, following the real outbreak of COVID-19, people's attitudes toward COVID-19 vaccines negatively predicts their worry about COVID-19 [z = -4.31, p < 0.001], indirectly resulting in a negative effect on their intention to adopt personal NPIs. This suggests the occurrence of the Peltzman effect. That is, vaccination fosters a sense of safety, subsequently diminishing alertness to COVID-19, and thus reducing the intention to adopt personal NPIs.

3D-printed microfluidic device for high-throughput production of lipid nanoparticles incorporating SARS-CoV-2 spike protein mRNA.

Lipid nanoparticles (LNPs) are drug carriers for protecting nucleic acids for cellular delivery. The first mRNA vaccines authorized by the United States Food and Drug Administration are the mRNA-1273 (Moderna) and BNT162b (BioNTech/Pfizer) vaccines against coronavirus disease 2019 (COVID-19). We designed a 3D printed Omnidirectional Sheath-flow Enabled Microfluidics (OSEM) device for producing mRNA-loaded LNPs that closely resemble the Moderna vaccine: we used the same lipid formulations to encapsulate mRNA encoding SARS-CoV-2 spike protein. The OSEM device is made of durable methacrylate-based materials that can support flow rates in the mL min-1 range and was fabricated by stereolithography (SLA), incorporating readily adaptable interfaces using commercial fluidic connectors. Two key features of the OSEM device are: 1) a 4-way hydrodynamic flow focusing region and 2) a staggered herringbone mixer (SHM). Superior to conventional planar fluid junctions, the 4-way sheath flow channel generates an evenly focused, circular center flow that facilitates the formation of LNPs with low polydispersity. Downstream, fluid mixing in the SHM is intensified by incorporating a zig-zag fluidic pathway to deliver high mRNA encapsulation efficiency. We characterized the mRNA-loaded LNPs produced in the OSEM device and showed that the enhanced 3D microfluidic structures enable a 5-fold higher throughput production rate (60 mL min-1) of LNPs compared to commercial multi-thousand-dollar micromixers. The device produced LNPs of diameter less than 90 nm, with low polydispersity (2-8%) and high mRNA encapsulation efficiency (>90%). The 3D-printed device provides a cost-effective and easily prepared solution for high-throughput LNP production.

Probing Thermal Transport on a Suspended Ti3C2Tx MXene Film via a Photothermally Actuated Resonator.

Two-dimensional (2D) Ti3C2Tx MXene materials show great potential in electrochemical and flexible sensors due to their high electrical conductivity, good chemical stability, and special delaminated structure. However, their thermal properties were rarely studied, which remarkably affect the stability and safety of various devices. Here, we fabricated a suspended MXene drum resonator photothermally driven by a sinusoidally modulated laser, measured the thermal time constant by demodulating the thermomechanical motion, and then calculated the thermal conductivity and thermal diffusivity of the MXene film. Experiments show the thermal conductivity of the film increases from 3.10 to 3.58 W/m·K while the thermal diffusivity from 1.06 × 10-6 to 1.22 × 10-6 m2/s when temperature increases from 300 to 360 K. We also confirm the film thermal conductivity is mainly contributed by phonon transport rather than electron transport. Furthermore, the relationship between the mechanical and thermal properties of the MXene films was disclosed. The thermal conductivity decreases when film strain increases, caused by enhanced phonon scattering and softening of high-frequency phonons. The measurements provide a noninvasive method to analyze the thermal characteristics of suspended MXene films, which can be further extended to the thermal properties of other 2D materials.

Clinical Outcomes of Tooth- and Implant-Supported Restorations Performed in a University-based Undergraduate Program after 13-15 Years.

AIMS: To assess the clinical concept of patient treatment with fixed tooth- and implant-supported restorations in a university-based undergraduate program after 13 - 15 years. METHODS: Thirty patients (mean age 56 years) who had received multiple tooth- and implant-supported restorations were recalled after 13-15 years. The clinical assessment comprised of biological and technical parameters as well as patient satisfaction. Data were analyzed descriptively and the 13-15-year survival rates for tooth- and implant-supported single crowns and fixed dental prostheses were calculated. RESULTS: The survival rate of tooth-supported restorations amounted to 88.3% (single crowns) and 69.6% (fixed dental prostheses); in implants it reached 100% for all types of reconstructions. Overall, 92.4% of all reconstructions were free of technical complications. The most common technical complication was chipping of the veneering ceramic (tooth-supported restorations: 5.5%; implant-supported restorations: 13-15.9%) regardless of the material used. At teeth, increased probing depth ≥5mm was the most frequent biological complication (22.8%), followed by endodontic complications of root-canal treated teeth (14%) and loss of vitality at abutment teeth (8.2%). Peri-implantitis was diagnosed in 10.2% of implants. CONCLUSION: Results of this study indicate that the clinical concept implemented in the undergraduate program and performed by undergraduate students works well. The clinical outcomes are similar to those reported in the literature. In general, the majority of biological complications occurrs in reconstructed teeth, whereas implant-supported restorations are more prone to technical complications.

A novel lncRNA LOC105613571 binding with BDNF in pituitary promotes gonadotropin secretion by AKT/ERK-mTOR pathway in sheep associated with prolificacy.

The pituitary is a vital endocrine organ for synthesis and secretion of gonadotropic hormones (FSH and LH), and the gonadotropin showed fluctuations in animals with different fecundity. Long non-coding RNAs (lncRNAs) have been identified as regulatory factors for the reproductive process. However, the profiles of lncRNAs and their roles involved in sheep fecundity remains unclear. In this study, we performed RNA-sequencing for the sheep pituitary gland associated with different fecundity, and identified a novel candidate lncRNA LOC105613571 targeting BDNF related to gonadotropin secretion. Our results showed that expression of lncRNA LOC105613571 and BDNF could be significantly upregulated by GnRH stimulation in sheep pituitary cells in vitro. Notably, either lncRNA LOC105613571 or BDNF silencing inhibited cell proliferation while promoted cell apoptosis. Moreover, lncRNA LOC105613571 knockdown could also downregulate gonadotropin secretion via inactivation AKT, ERK and mTOR pathway. In addition, co-treatment with GnRH stimulation and lncRNA LOC105613571 or BDNF knockdown showed the opposite effect on sheep pituitary cells in vitro. In summary, BDNF-binding lncRNA LOC105613571 in sheep regulates pituitary cell proliferation and gonadotropin secretion via the AKT/ERK-mTOR pathway, providing new ideas for the molecular mechanisms of pituitary functions.

The oral health landscape in Singapore: A commentary on key features, challenges and future policies.

Over the last decade, Singapore has grappled with substantial healthcare challenges, chiefly a bourgeoning aging population and a mounting burden of chronic diseases. The oral health landscape has also changed, with the Ministry of Health placing a greater focus on a life-course approach supported by policies that facilitate Singaporeans to receive dental care appropriately and affordably. A pivotal oral health policy is the National Dental Strategy, a comprehensive framework governing dental services in the public sector. This strategy encompasses aspects such as financing, workforce management, and capacity considerations. To facilitate affordability and accessibility to dental services in the public sector, the government extends subsidies to reduce out-of-pocket costs. Those attending private dental clinics also benefit from the Community Health Assist Scheme, introduced in 2012, which alleviates treatment costs for enrolled Singaporeans. Furthermore, additional age-banded subsidies have been introduced for older Singaporeans born before 1960, enhancing financial support when accessing dental services in both private and public sectors. In 2019, a national adult oral health survey was commissioned to gauge the oral health status of Singaporeans aged 21 and above. The findings reported 34.8% having untreated dental caries, and 15.7% and 41.2% experiencing moderate and severe periodontitis, respectively. While over half (53.9%) of respondents visited the dentist at least annually, about 60% of eligible individuals did not utilize their government dental subsidies. In response, the Ministry of Health is committed to strengthening oral disease prevention, integrating oral health into general healthcare services, expanding dental financing schemes to enhance service utilization, improving the quality and transparency of dental care, and leveraging advancements in tele-dentistry and other modes of dental services. It is imperative to adapt Singapore's oral health policies and service delivery models to meet the evolving needs of the population and ensure a sustainable, equitable and resilient oral healthcare system.

A novel intronic variant in ROBO3 associated with horizontal gaze palsy with progressive scoliosis: case report and literature review.

Horizontal gaze palsy with progressive scoliosis (HGPPS) is a rare, autosomal recessive inherited disorder caused by mutations in ROBO3 gene. The clinical features of HGPPS include horizontal gaze palsy, progressive scoliosis, other oculomotor abnormalities such as strabismus and nystagmus. Whole-exome sequencing (WES) is used to diagnose rare Mendelian disorders, when routine standard tests have failed to make a formal pathological diagnosis. However, WES may identify variants of uncertain significance (VUS) that may add further ambiguity to the diagnosis. We report the case of a 4-year-old boy with horizontal gaze palsy, progressive scoliosis, microcephaly, and mild developmental delay. WES identified an intronic VUS in ROBO3 gene. We performed minigene splicing functional analysis to confirm the pathogenicity of this VUS. This report illustrates that WES data analysis with supportive functional analysis provides an effective approach to improve the diagnostic yield for unsolved clinical cases. This case also highlights the phenotypic heterogeneity in patients with HGPPS.

Structural basis of peptide secretion for Quorum sensing by ComA.

Quorum sensing (QS) is a crucial regulatory mechanism controlling bacterial signalling and holds promise for novel therapies against antimicrobial resistance. In Gram-positive bacteria, such as Streptococcus pneumoniae, ComA is a conserved efflux pump responsible for the maturation and secretion of peptide signals, including the competence-stimulating peptide (CSP), yet its structure and function remain unclear. Here, we functionally characterize ComA as an ABC transporter with high ATP affinity and determined its cryo-EM structures in the presence or absence of CSP or nucleotides. Our findings reveal a network of strong electrostatic interactions unique to ComA at the intracellular gate, a putative binding pocket for two CSP molecules, and negatively charged residues facilitating CSP translocation. Mutations of these residues affect ComA's peptidase activity in-vitro and prevent CSP export in-vivo. We demonstrate that ATP-Mg2+ triggers the outward-facing conformation of ComA for CSP release, rather than ATP alone. Our study provides molecular insights into the QS signal peptide secretion, highlighting potential targets for QS-targeting drugs.

Ultrasensitive Acoustic Detection Using an Enlarged Fabry-Perot Cavity with a Graphene Diaphragm.

For exerting high sensitivity of ultrathin graphene to detection deformation, an enlarged backing air cavity (EBC) structure is developed to further enhance the mechanical sensitivity (SM) of a graphene-based Fabry-Perot (F-P) acoustic sensor. COMSOL acoustic field simulation on the air cavity size-dependent SM confirms the optimal length and radius of the EBC of 0.2 and 1.5 mm, respectively, with the maximum simulation SM of 26.16 nm/Pa@1 kHz. Acoustic experiments further demonstrate that the frequency response of the fabricated graphene-based F-P acoustic sensor after the use of the EBC is enhanced by 5.73-79.33 times in the range of 0.5-18 kHz, compared with the conventional one without the EBC. Especially the maximum SM is up to 187.32 nm/Pa@16 kHz, which is at least 17% higher than the SM values ranging from 1.1 to 160 nm/Pa in previously reported F-P acoustic sensors using various diaphragm materials. More acoustic characteristics are examined to highlight various merits of the EBC structure, including a signal-to-noise ratio (SNR) of 60-75 dB@0.5-18 kHz, a time stability of less than ±1.3% for 90 min, a detection resolution of 0.01 Hz, and a high-fidelity speech detection with a cross-correlation coefficient of greater than 0.9, thereby revealing its high-performance weak acoustic sensing and speech recognition applications.

Association Between Adult Antibiotic Use, Microbial Dysbiosis and Atopic Conditions - A Systematic Review.

Background: Strong associations between early antibiotic exposure and increased risk of childhood allergies have been established. Antibiotics have the potential to induce microbial dysbiosis that may be linked to allergic conditions. This review examines the limited available evidence on the associations between adult antibiotic use, microbial dysbiosis and atopic conditions. Methods: A systematic literature search was conducted using PubMed and Embase for relevant studies, published between 01-01-2000 and 08-17-2022. We searched for associations between antibiotic use, microbial dysbiosis, and allergic conditions in adults, defined as over 13 years of age for the purposes of this review. Results: Twenty-one studies were analyzed, with the inclusion of four narrative reviews as scarce relevant literature was found when stricter selection criteria were employed. Relevant studies predominantly focused on asthma. Significant microbial differences were observed in most measures between healthy subjects and subjects with allergic conditions. However, no system-wise and strain-wise associations were evident. Notably, at the phyla level, the Bacillota and Pseudomonadota phyla were associated with asthmatics, while the Actinobacteria phylum was linked to healthy controls. Asthmatics tends to reflect upregulation in the Bacillota and Pseudomonadota phyla in both airway and gut microbiomes. Conclusion: No compelling evidence could be found between adult antibiotic exposure, consequent microbial dysbiosis, and allergic conditions in adults. Our review is limited by scarce literature and therefore remains inconclusive. However, potential implications of antibiotic use impacting on allergic conditions justify additional research and heightened pharmacovigilance in this area.

Measurement of Thermal Stress by X-ray Nano-Diffraction in (111)-Oriented Nanotwinned Cu Bumps for Cu/SiO2 Hybrid Joints.

X-ray nanodiffraction was used to measure the thermal stress of 10 µm nanotwinned Cu bumps in Cu/SiO2 hybrid structures at -55 °C, 27 °C, 100 °C, 150 °C, and 200 °C. Bonding can be achieved without externally applied compression. The X-ray beam size is about 100 nm in diameter. The Cu bump is dominated by (111) oriented nano-twins. Before the hybrid bonding, the thermal stress in Cu bumps is compressive and remains compressive after bonding. The average stress in the bonded Cu joint at 200 °C is as large as -169.1 MPa. In addition, using the strain data measured at various temperatures, one can calculate the effective thermal expansion coefficient (CTE) for the 10 µm Cu bumps confined by the SiO2 dielectrics. This study reports a useful approach on measuring the strain and stress in oriented metal bumps confined by SiO2 dielectrics. The results also provide a deeper understanding on the mechanism of hybrid bonding without externally applied compression.

Rewiring the pneumococcal capsule pathway for investigating glycosyltransferase specificity and genetic glycoengineering.

Virtually all living cells are covered with glycans. Their structures are primarily controlled by the specificities of glycosyltransferases (GTs). GTs typically adopt one of the three folds, namely, GT-A, GT-B, and GT-C. However, what defines their specificities remain poorly understood. Here, we developed a genetic glycoengineering platform by reprogramming the capsular polysaccharide pathways in Streptococcus pneumoniae to interrogate GT specificity and manipulate glycan structures. Our findings suggest that the central cleft of GT-B enzymes is important for determining acceptor specificity. The constraint of the glycoengineering platform was partially alleviated when the specificity of the precursor transporter was reduced, indicating that the transporter contributes to the overall fidelity of glycan synthesis. We also modified the pneumococcal capsule to produce several medically important mammalian glycans, as well as demonstrated the importance of regiochemistry in a glycosidic linkage on binding lung epithelial cells. Our work provided mechanistic insights into GT specificity and an approach for investigating glycan functions.

Identification of an immunodominant IgE epitope of Der f 40, a novel allergen of Dermatophagoides farinae.

Background: House dust mites (HDMs), including Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f) species, represent a major source of inhalant allergens that induce IgE-mediated anaphylactic reactions. HDM allergen identification is important to the diagnosis and treatment of allergic diseases. Here, we report the identification of a novel HDM allergen, which we suggest naming Der f 40, and its immunodominant IgE epitopes. Methods: The recombinant protein Der f 40 was expressed using a pET prokaryotic expression system and purified with Ni-NTA resins. IgE binding activity was evaluated by IgE-western blot, dot-blot, and ELISA. Mast cell activation testing was performed to assess the cellular effects of IgE binding in mouse bone marrow derived mast cells (BMMCs) expressing human FcεRI. IgE binding assays were performed with truncated and hybrid Der f 40 protein molecules to find immunodominant IgE epitopes. Results: A 106-amino acid (aa) recombinant Der f Group 40 protein (rDer f 40) was obtained (GenBank accession No. XP_046915420.1) as thiredoxin-like protein. Der f 40 was shown to bind IgE from HDM allergic serum in vitro (9.68%; 12/124 in IgE-ELISA), and shown to promote the release of ß-hexosaminidase from BMMCs dose-dependently when administered with HDM allergic sera. The Der f Group 40 protein was named Der f 40 and listed in the World Health Organization and International Union of Immunological Societies (WHO/IUIS) Allergen Nomenclature Sub-committee. IgE binding assays with Der f 40-based truncated and hybrid proteins indicated that IgE binding epitopes are likely located in the C-terminal region and dependent on conformational structure. The 76-106-aa region of C-terminus was identified as an immunodominant IgE epitope of Der f 40. Conclusion: A novel HDM allergen with robust IgE binding activity was identified and named Der f 40. An immunodominant IgE epitope of Der f 40 with conformational dependency was identified in the C-terminus (aa 76-106). These findings provide new information that may be useful in the development of diagnostic and therapeutic agents for HDM allergy.