Engineering of Halide Methyltransferase BxHMT through Dynamic Cross-correlation Network Analysis

Halide methyltransferases (HMTs) provide an effective way to regenerate S-adenosyl methionine (SAM) from S-adenosyl homocysteine and reactive electrophiles such as methyl iodide (MeI) or methyl toluene sulfonate (MeOTs). Compared with MeI, the cost-effective unnatural substrate MeOTs can be accessible directly from cheap and abundant alcohols, but shows only limited reactivity in SAM production. Herein, we developed a dynamic cross-correlation network analysis (DCCNA) strategy for quickly identifying hot spots influencing the enzyme's catalytic efficiency, and applied it to the evolution of HMT from Paraburkholderia xenovorans. Finally, the optimal mutant, M4 (V55T/C125S/L127T/L129P), exhibited remarkable improvements, with a specific activity of 4.08 U/mg towards MeOTs, representing an 82-fold increase compared to the wild-type (WT). Notably, M4 also demonstrated a positive impact on the catalytic ability with other methyl donors. The structural mechanism behind the enhanced enzyme activity was uncovered by molecular dynamics simulations. Our work not only contributes promising biocatalyst for the regeneration of SAM, but also offers a strategy for efficient enzyme engineering.

Predictive effect of net water uptake on futile recanalisation in patients with acute large-vessel occlusion stroke

AIM

To determine whether net water uptake (NWU) based on automated software evaluation could predict futile recanalisation in patients with acute anterior circulation large-vessel occlusion (LVO).

MATERIALS AND METHODS

Patients with acute anterior circulation LVO undergoing mechanical thrombectomy in Jinling Hospital were evaluated retrospectively. NWU and other baseline data were evaluated by performing univariate and multivariate analyses. The primary endpoint was 90-day modified Rankin scale score ≥3. A nomogram to predict poor clinical outcomes was developed based on multivariate logistic regression analysis.

RESULTS

Overall, 135 patients who underwent thrombectomy with a TICI grade ≥2b were enrolled. In multivariate logistic regression analysis, the following factors were identified as independent predictors of futile recanalisation: age (odds ratio [OR]: 1.055, 95 % confidence interval [CI]: 1.004-1.110, p=0.035), female (OR: 0.289, 95 % CI: 0.098-0.850, p=0.024), hypertension (OR: 3.182, 95 % CI: 1.160-8.728, p=0.025), high blood glucose level (OR: 1.36, 95 % CI: 1.087-1.701, p=0.007), admission National Institutes of Health Stroke Scale score (OR: 1.082, 95 % CI: 1.003-1.168, p=0.043), and NWU (OR: 1.312, 95 % CI: 1.038-1.659, p=0.023).

CONCLUSIONS

NWU based on Alberta Stroke Program Early Computed Tomography (CT) Score (ASPECTS) could be used to predict the occurrence of futile recanalisation in patients with acute anterior circulation LVO ischaemic stroke.

Distribution and characteristics of bacteria on the hand during oropharyngeal swab collection: Which handwashing points are affected?

AIMS

To identify the contaminated areas of the hand collection and analyse the distribution characteristics of bacteria in the hand after swab collection.

DESIGN

This study used a cross-sectional design.

METHODS

A cross-sectional study sampling 50 pairs of hands (sampling hand and auxiliary hand) of healthcare workers was performed. Ten samples were collected from each participant. The optimal hand hygiene rates and bacterial colony counts of the whole hand and different hand sections without hand hygiene were identified as the primary outcomes.

RESULTS

The optimal hand hygiene rates of the sampling hand and auxiliary hand were 88.8% (222/250) and 91.6% (229/250), respectively. The lowest optimal hand hygiene rates for the sampling hand and the auxiliary hand were both on the dorsal side of the finger and the dorsum of the hand (86.0%, 86.0% vs. 90.0%, 86.0%); the optimal hand hygiene rates for both sites of the sampling hand were 86.0% (43/50), and the optimal hand hygiene rates for the auxiliary hand were 90.0% (45/50) and 86.0% (43/50). The bacteria colony counts did not differ between the sampling hands and auxiliary hand.

CONCLUSIONS

The dorsal side of the finger and dorsum of the hand were the most likely to be contaminated during oropharyngeal swab collection. Therefore, it is essential to pay extra attention to hand hygiene care of these two sites during the collection process to minimize the risk of cross-contamination.

REPORTING METHOD

The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines were adopted in this study.

Design of target specific peptide inhibitors using generative deep learning and molecular dynamics simulations

We introduce a computational approach for the design of target-specific peptides. Our method integrates a Gated Recurrent Unit-based Variational Autoencoder with Rosetta FlexPepDock for peptide sequence generation and binding affinity assessment. Subsequently, molecular dynamics simulations are employed to narrow down the selection of peptides for experimental assays. We apply this computational strategy to design peptide inhibitors that specifically target β-catenin and NF-κB essential modulator. Among the twelve β-catenin inhibitors, six exhibit improved binding affinity compared to the parent peptide. Notably, the best C-terminal peptide binds β-catenin with an IC50 of 0.010 ± 0.06 μM, which is 15-fold better than the parent peptide. For NF-κB essential modulator, two of the four tested peptides display substantially enhanced binding compared to the parent peptide. Collectively, this study underscores the successful integration of deep learning and structure-based modeling and simulation for target specific peptide design.

Global trends in coronary artery disease and artificial intelligence relevant studies: a bibliometric analysis

OBJECTIVE

Coronary artery disease (CAD) is a major global cause of death, greatly affecting life expectancy and quality of life for populations. With the advent of artificial intelligence (AI), there is new hope for accurately managing CAD. While recent studies have shown remarkable progress in AI and CAD research, there is a gap in comprehensive bibliometric analysis in this field. Therefore, this study aims to provide a thorough analysis of trends and hotspots in AI and CAD-related research utilizing bibliometrics.

MATERIALS AND METHODS

Publications on AI and CAD relevant research from 2009 to 2023 were searched through the WoS core database (WoSCC). CiteSpace, VOSviewer and Excel 365 were used to conduct the bibliometric analysis.

RESULTS

The bibliometric analysis included 1,248 publications, indicating a steady increase in AI and CAD-related publications annually. The United States of America (USA), China, and Germany were identified as the most influential countries in this field. Research institutions such as Cedars Sinai Med Ctr, Med Univ South Carolina, Harvard Med Sch and Capital Med Univ were the main contributors to research production. FRONT CARDIOVASC MED is the top-ranked journal, while J AM COLL CARDIOL emerged as the most cited journal. Schoepf, U. Joseph, Slomka, Piotr J., Berman, Daniel S. and Dey, Damini were the most prolific authors, while U. Rajendra Acharya was the most frequently co-cited author. Research related to the AI calculation of coronary flow reserve fraction and coronary artery calcification, based on coronary CT to identify CAD and cardiovascular risk, was a key research topic in this field. The potential link between cardiovascular risk stratification and radiomics is currently at the forefront of the field.

CONCLUSIONS

This study is the first to use a bibliometric approach to visualize and analyze AI and CAD-related research. The findings provide insights into recent research trends and hotspots in the field and can serve as a reference for scholars to identify critical issues in this field.

A risk model based on the tumor microenvironment to predict survival and immunotherapy efficacy for ovarian cancer

OBJECTIVE

Based on the interactions between immune components in the tumor microenvironment and ovarian cancer (OC) cells, immunotherapies have been demonstrated to be effective in dramatically increasing survival rates. This study aimed to identify landmark genes, develop a prognostic risk model, and explore its relevance to the efficacy of immunotherapy.

MATERIALS AND METHODS

A risk model was built based on the immune- and stromal-related genes, which were extracted from the OC gene expression data of "The Cancer Genome Atlas" (TCGA) database. Survival analysis and receiver operating characteristic (ROC) analysis were then conducted through the model's risk score pattern, which was established depending on the TCGA training cohort and verified based on the internal TCGA cohort and external "Gene Expression Omnibus" (GEO) datasets. Furthermore, the immune-related characteristics and prognostic values of the risk model were evaluated.

RESULTS

The prognostic risk model for ovarian cancer demonstrated excellent performance in predicting survival rates, as validated in both the TCGA and GEO databases. The model showed significant associations with 17 functional immune cells, 17 immune checkpoints, PD-1, and several immune pathways, suggesting its potential to enhance the efficacy of immunotherapy in OC.

CONCLUSIONS

The risk model developed in this study has the potential to serve as a prognostic marker for OC, enabling the development of personalized immunotherapy protocols and providing a theoretical basis for novel combinations of immunotherapeutic approaches.

[Predictive value of aMAP risk score for early recurrence of small hepatocellular carcinoma after microwave ablation]

Objective: To explore the value of the aMAP risk score (age, male, albumin-bilirubin, and platelets) to predict early recurrence within one year after microwave ablation in patients with small hepatocellular carcinoma. Methods: This was a retrospective study that enrolled 142 patients diagnosed with hepatocellular carcinoma who were treated with microwave ablation in the Department of Hepatology Unit of Nanfang Hospital, Southern Medical University from July 2016 to July 2021. The cohort enrolled 121 male and 21 female patients, including 110 patients that were <60 years old. All the patients were followed-up after microwave ablation to evaluate residual tumor and recurrence of tumor by computed tomography or magnetic resonance imaging. The observation indices mainly included general data and imaging data of patients. Using the X-tile tools, patients were divided into two groups: a high aMAP score group and a low aMAP score group. Multivariate Cox regression analysis was conducted for comparison of independent risk factors. Results: Multivariate Cox regression showed that high aMAP score, maximum tumor diameter >20 mm, and high AFP were the independent risk factors of early recurrence (all P<0.05). Kaplan-Meier survival curves showed that the median recurrence-free survival was 25.5 months in the low aMAP score group and 6.1 months in the high aMAP score group (P=0.001). Conclusions: The aMAP score could predict the early recurrence within 1 year of small hepatocellular carcinoma after microwave ablation. Patients with high aMAP score should undergo rigorous postoperative follow-up evaluations..

[The association between cortical venous outflow and futile recanalization in patients with acute ischemic stroke due to large vessel occlusion in the anterior circulation]

Objective: To explore the association of baseline venous outflow (VO) profile with futile recanalization in patients with acute ischemic stroke due to large vessel occlusion in the anterior circulation. Methods: The clinical and imaging data of patients presented with large vessel occlusion in the anterior circulation and underwent emergency endovascular treatment at Huashan Hospital from March 2015 to December 2021 were retrospectively included in the study. All patients were assessed by the National Institutes of Health Stroke Scale (NIHSS) at baseline.Baseline VO profile was determined by a 0-6 semi-quantitative scoring system which assessed opacification of the ipsilateral superficial middle cerebral vein, vein of Labbé and vein of Trolard on single-phase CT angiography (CTA) images. A 90-day telephone follow-up was performed and functional outcome was evaluated by 90 d modified Rankin scale (mRS). Successful recanalization of the occluded artery, defined as final modified Thrombolysis in Cerebral Infarction scale (mTICI) 2b-3, was considered to be futile if patients failed to achieve functional independence (90 d mRS 0-2). Univariate analysis and receiver operating characteristic (ROC) curve analysis were used to explore the optimal cutoff predicting functional indendence. The associations between cortical VO in ischemic area and futile recanalization were evaluated using binary logistic regression analysis and backward linear regression based on Akaike information criterion (AIC). Results: A total of 150 patients met the inclusion criteria, with 92 males (61.3%) and 58 females (38.7%). The median age [M(Q1, Q3)]was 71 (61, 78) years and the median baseline National Institute of Health Stroke Scale (NIHSS) score [M(Q1, Q3)]was 15 (11, 18). Univariate logistic regression analysis showed that baseline VO was associated with 90-day functional independence (OR=1.587, 95%CI: 1.185-2.1873). After classifying VO into two categories based on the receiver operating characteristic (ROC) curve, VO≥4 showed an independent association with functional independence (OR=5.133, 95%CI: 1.530-9.361) after adjusting for age, baseline glucose, NIHSS score, baseline infarct core volume, modified Tan (mTan) score, hypoperfusion intensity ratio (HIR), etiological classification, recanalization, presence of any hemorrhagic transformation and final infarct volume. Futile recanalization was observed in 44 (48.4%) of the 91 patients who achieved successful recanalization. Stepwise logistic regression revealed that VO≥4 was an independent protective factor for futile recanalization (OR=0.234, 95%CI: 0.054-0.878). Moreover, in patients with mTICI 2c-3, VO≥4 showed a stronger association with futile recanalization (OR=0.018, 95%CI: 0-0.255). Conclusion: A favorable VO profile at onset protects against futile recanalization in patients with large vessel occlusion in the anterior circulation, and provides a simple and feasible auxiliary method for predicting the prognosis of endovascular therapy in such patients.

Repression of ferroptotic cell death by mitochondrial calcium signaling

The uptake of Ca2+ into and extrusion of calcium from the mitochondrial matrix, regulated by the mitochondrial Ca2+ uniporter (MCU), is a fundamental biological process that has crucial impacts on cellular metabolism, signaling, growth and survival. Herein, we report that the embryonic lethality of Mcu-deficient mice is fully rescued by orally supplementing ferroptosis inhibitor lipophilic antioxidant vitamin E and ubiquinol. Mechanistically, we found MCU promotes acetyl-CoA-mediated GPX4 acetylation at K90 residue, and K90R mutation impaired the GPX4 enzymatic activity, a step that is crucial for ferroptosis. Structural analysis supports the possibility that GPX4 K90R mutation alters the conformational state of the molecule, resulting in disruption of a salt bridge formation with D23, which was confirmed by mutagenesis studies. Finally, we report that deletion of MCU in cancer cells caused a marked reduction in tumor growth in multiple cancer models. In summary, our study provides a first direct link between mitochondrial calcium level and sustained GPX4 enzymatic activity to regulate ferroptosis, which consequently protects cancer cells from ferroptosis.

The Cytotoxic Cardiac Glycoside (-)-Cryptanoside A from the Stems of Cryptolepis dubia and Its Molecular Targets

A cardiac glycoside epoxide, (-)-cryptanoside A (1), was isolated from the stems of Cryptolepis dubia collected in Laos, for which the complete structure was confirmed by analysis of its spectroscopic and single-crystal X-ray diffraction data, using copper radiation at a low temperature. This cardiac glycoside epoxide exhibited potent cytotoxicity against several human cancer cell lines tested, including HT-29 colon, MDA-MB-231 breast, OVCAR3 and OVCAR5 ovarian cancer, and MDA-MB-435 melanoma cells, with the IC50 values found to be in the range 0.1-0.5 μM, which is comparable with that observed for digoxin. However, it exhibited less potent activity (IC50 1.1 μM) against FT194 benign/nonmalignant human fallopian tube secretory epithelial cells when compared with digoxin (IC50 0.16 μM), indicating its more selective activity toward human cancer versus benign/nonmalignant cells. (-)-Cryptanoside A (1) also inhibited Na+/K+-ATPase activity and increased the expression of Akt and the p65 subunit of NF-κB but did not show any effects on the expression of PI3K. A molecular docking profile showed that (-)-cryptanoside A (1) binds to Na+/K+-ATPase, and thus 1 may directly target Na+/K+-ATPase to mediate its cancer cell cytotoxicity.

The Mechanism of the Anti-Cardiac Hypertrophy Effect of Glycyrrhizic Acid Is Related to Reducing STIM1-Dependent Store-Operated Calcium Entry

We explored the anti-cardiac hypertrophy mechanism of glycyrrhizic acid from the perspective of calcium regulation under pathological conditions. For this purpose, we used a rat model of myocardial hypertrophy induced by pressure overload. The effect of glycyrrhizic acid on BP was measured non-invasively with a sphygmomanometer and recorded in PC. In rats with modeled cardiac hypertrophy, the effect of GA on expression of type 1 matrix interaction molecules was determined in horizontal tissues and cultured cardiomyocytes of the left ventricle. The laser confocal microscopy and calcium ion probe Fluo-4 AM were used to assess the effect of glycyrrhizic acid on stromal interaction molecule 1 (STIM1)-dependent store-operated calcium entry in cultured cardiomyocytes derived from the hypertrophic myocardium. Glycyrrhizic acid exerted the anti-hypertrophic effect in rats with hypertrophic myocardium by down-regulating STIM1 protein expression and reducing the intensity of STIM1-dependent store-operated calcium entry.

Exploring the effect of novel 6 moments on hand hygiene compliance among hospital cleaning staff members: a quasi-experimental study

My 5 moments (M5M) was used less frequently among cleaning staff members, suggesting that a poor compliance score in this group may not indicate deficient handwashing. This quasi-experimental study compared hand hygiene compliance (HHC), hand hygiene (HH) moments, and HH time distribution in the control group (no HH intervention; n = 21), case group 1 (normal M5M intervention; n = 26), case group 2 (extensive novel six moments (NSM) training; n = 24), and case group 3 (refined NSM training; n = 18). The intervention's effect was evaluated after 3 months. The HHC gap among the four groups gradually increased in the second intervention month (control group, 31.43%; case group 1, 38.74%; case group 2, 40.19%; case group 3, 52.21%; p < 0.05). After the intervention period, the HHC of case groups 2 and 3 improved significantly from the baseline (23.85% vs. 59.22%, 27.41% vs. 83.62%, respectively; p < 0.05). 'After transferring medical waste from the site' had the highest HHC in case group 3, 90.72% (95% confidence interval, 0.1926-0.3967). HH peak hours were from 6 AM to 9 AM and 2 PM to 3 PM. The study showed that the implementation of an NSM practice can serve as an HHC monitoring indicator and direct relevant training interventions to improve HH among hospital cleaning staff.

[Visceral leishmaniasis in Xinjiang Uygur Autonomous Region during the COVID-19 pandemic: a case report]

OBJECTIVE

To perform an epidemiological investigation on a case of visceral leishmaniasis reported from Shule County, Kashi Prefecture, Xinjiang Uygur Autonomous Region in 2021, so as to provide insights into differential diagnosis of visceral leishmaniasis during the COVID-19 pandemic.

METHODS

The epidemiological history of this case was collected, and the case was diagnosed for Leishmania infection with the immunochromatographic (rK39) strip test, bone marrow smear microscopy and PCR assay.

RESULTS

The patient had typical clinical symptoms of leishmaniasis, including irregular fever, hepatosplenomeg- aly, low serum albumin and elevated globulin. Bone marrow smear microscopy identified L. donovani amastigotes, and both rK39 strip test and PCR assay were positive, while the case was tested negative for SARS-CoV-2. COVID-19 was therefore excluded and visceral leishmaniasis was diagnosed. Standard full-dose treatment with sodium stibogluconate was given, and no Leishmania was found on blood smears during the reexamination. No recurrence was found during the followup after discharge for hospital.

CONCLUSIONS

During the COVID-19 pandemic, it is recommended to increase the perception of differential diagnosis of visceral leishmaniasis among first-contact doctors, and reinforce the capability of differential diagnosis and health education of visceral leishmaniasis among medical and healthcare institutions at all levels, to prevent missed diagnosis and misdiagnosis of visceral leishmaniasis.

Ultra-high-resolution observations of persistent null-point reconnection in the solar corona

Magnetic reconnection is a key mechanism involved in solar eruptions and is also a prime possibility to heat the low corona to millions of degrees. Here, we present ultra-high-resolution extreme ultraviolet observations of persistent null-point reconnection in the corona at a scale of about 390 km over one hour observations of the Extreme-Ultraviolet Imager on board Solar Orbiter spacecraft. The observations show formation of a null-point configuration above a minor positive polarity embedded within a region of dominant negative polarity near a sunspot. The gentle phase of the persistent null-point reconnection is evidenced by sustained point-like high-temperature plasma (about 10 MK) near the null-point and constant outflow blobs not only along the outer spine but also along the fan surface. The blobs appear at a higher frequency than previously observed with an average velocity of about 80 km s^-1 and life-times of about 40 s. The null-point reconnection also occurs explosively but only for 4 minutes, its coupling with a mini-filament eruption generates a spiral jet. These results suggest that magnetic reconnection, at previously unresolved scales, proceeds continually in a gentle and/or explosive way to persistently transfer mass and energy to the overlying corona.

Abstract 3110: Design, synthesis, and biological evaluation of transducin β-like protein 1 (TBL1) degraders

Transducin β-like protein 1 (TBL1) is an essential scaffold protein that participates in multiple critical signaling pathways, such as the Wnt/β-catenin pathway, where it protects β-catenin from ubiquitination and proteasomal degradation. Only one compound, BC-2059 (tegavivint, Iterion Therapeutics), has been reported to promote apoptosis by disrupting the TBL1/β-catenin interactions and show promising therapeutic effects in Wnt-driven cancers, such as colorectal cancer, breast cancer, and leukemia. However, recent studies showed that TBL1 modulates Wnt-regulated genes in a β-catenin-independent manner in diffuse large B-cell lymphoma (DLBCL). Although the involvement of β-catenin is still under debate, TBL1’s engagement in the antitumor effects of BC-2059 is certain and critical. In this study, we aimed to develop proof-of-concept BC-2059-based TBL1 selective degraders against DLBCL using the Proteolysis Targeting Chimeras (PROTACs) strategy and use them as chemical probes to investigate TBL1-related pathways in DLBCL. Two series (N- and O-linked) of BC-2059-based PROTACs were synthesized, and their cytotoxicity and protein degradation profiles were tested in cellular assays. Several compounds showed low micromolar to nanomolar cytotoxic activity. The TBL1 degradation of these PROTACs is currently underway. In the meantime, we modeled the ternary complex formation by developing a workflow where two binary complexes and a library of PROTACs having varied linker lengths/chemical compositions were modeled by PRosettaC. The protein-protein interactions of the generated ternary complexes were analyzed by Rosetta and the interactions between the linkers and the protein were calculated by Autodock 4. The results suggested that short linkers (8-14 heavy atoms) are more suitable for N-linked series degraders in terms of PROTAC-induced ternary complex formation, while long linkers (&gt;18 heavy atoms) are preferable for O-linked series.

Citation Format: Rui Yang, Lapo Alinari, Pui-kai (Tom) Li, Xiaolin Cheng. Design, synthesis, and biological evaluation of transducin β-like protein 1 (TBL1) degraders [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3110.

Cholesterol-Amino-Phosphate (CAP) Derived Lipid Nanoparticles for Delivery of Self-Amplifying RNA and Restoration of Spermatogenesis in Infertile Mice

Male infertility caused by genetic mutations is an important type of infertility. Currently, there is no reliable method in the clinic to address this medical need. The emergence of mRNA therapy provides a possible strategy for restoring mutant genes in the reproductive system. However, effective delivery of mRNA to spermatocytes remains a formidable challenge. Here a series of cholesterol-amino-phosphate (CAP) lipids are reported by integrating three bioactive moieties into a geometric structure, which is favorable for mRNA delivery. The results demonstrate that CAP-derived lipid nanoparticles (CAP LNPs) can deliver RNA including traditional mRNA and self-amplifying RNA (saRNA) encoding DNA Meiotic Recombinase 1 (Dmc1) protein in spermatocytes and treat male infertility caused by the Dmc1 gene mutation. Notably, the delivery efficiency of CAP LNPs is significantly higher than that of the MC3 and ALC-0315 LNPs, which is consistent with the design of CAP molecules. More importantly, a single injection of CAP LNPs-saRNA can produce Dmc1 protein for an extended period, which restores the spermatogenesis in the Dmc1 gene knockout mouse model. Overall, this study proves the concept of LNPs for the delivery of mRNA to spermatocytes, which provides a unique method to probe male infertility caused by the genetic mutation.

[Research advances on invasive fungal infections after burns]

Invasive fungal infection (IFI) is one of the serious complications in burn patients. The gradual development and application of broad-spectrum antibiotics in recent years has led to a serious dysbiosis of the flora, while the widespread prophylactic use of antifungal drugs has led to an increasing number of drug-resistant fungi. The clinical treatment of IFI is difficult and the prognosis is poor. The mortality of burn patients caused by IFI is increasing year by year. This paper reviews the epidemiologic characteristics, related risk factors, diagnostic methods, and treatment progress of IFI after burns, aiming to provide new ideas and reference for the prevention and treatment of IFI after burns.

Molecular Dynamics Refinement of Open State Serotonin 5-HT3A Receptor Structures

Pentameric ligand-gated ion channels play an important role in mediating fast neurotransmissions. As a member of this receptor family, cation-selective 5-HT₃ receptors are a clinical target for treating nausea and vomiting associated with chemotherapy and radiation therapy (Thompson and Lummis, 2006). Multiple cryo-electron microscopy (cryo-EM) structures of 5-HT₃ receptors have been determined in distinct functional states (e.g., open, closed, etc.) (Basak et al., 2018; Basak et al., 2018; Polovinkin et al., 2018; Zhang et al., 2015). However, recent work has shown that the transmembrane pores of the open 5-HT₃ receptor structures rapidly collapse and become artificially asymmetric in molecular dynamics (MD) simulations. To avoid this hydrophobic collapse, Dämgen and Biggin developed an equilibration protocol that led to a stable open state structure of the glycine receptor in MD simulations (Dämgen and Biggin, 2020). However, the protocol failed to yield open-like structures of the 5-HT₃ receptor in our simulations. Here, we present a refined equilibration protocol that involves the rearrangement of the transmembrane helices to achieve stable open state structures of the 5-HT₃ receptor that allow both water and ion permeation through the channel. Notably, channel gating is mediated through collective movement of the transmembrane helices, involving not only pore lining M2 helices but also their cross-talk with the adjacent M1 and M3 helices. Thus, the successful application of our refined equilibration protocol underscores the importance of the conformational coupling between the transmembrane helices in stabilizing open-like structures of the 5-HT₃ receptor.

Voltage controlled shutter regulates channel size and motion direction of protein aperture as durable nano-electric rectifier-----An opinion in biomimetic nanoaperture

In optical devices such as camera or microscope, an aperture is used to regulate light intensity for imaging. Here we report the discovery and construction of a durable bio-aperture at nanometerscale that can regulate current at the pico-ampere scale. The nano-aperture is made of 12 identical protein subunits that form a 3.6-nm channel with a shutter and "one-way traffic" property. This shutter responds to electrical potential differences across the aperture and can be turned off for double stranded DNA translocation. This voltage enables directional control, and three-step regulation for opening and closing. The nano-aperture was constructed in vitro and purified into homogeneity. The aperture was stable at pH2-12, and a temperature of -85C-60C. When an electrical potential was held, three reproducible discrete steps of current flowing through the channel were recorded. Each step reduced 32% of the channel dimension evident by the reduction of the measured current flowing through the aperture. The current change is due to the change of the resistance of aperture size. The transition between these three distinct steps and the direction of the current was controlled via the polarity of the voltage applied across the aperture. When the C-terminal of the aperture was fused to an antigen, the antibody and antigen interaction resulted in a 32% reduction of the channel size. This phenomenon was used for disease diagnosis since the incubation of the antigen-nano-aperture with a specific cancer antibody resulted in a change of 32% of current. The purified truncated cone-shape aperture automatically self-assembled efficiently into a sheet of the tetragonal array via head-to-tail self-interaction. The nano-aperture discovery with a controllable shutter, discrete-step current regulation, formation of tetragonal sheet, and one-way current traffic provides a nanoscale electrical circuit rectifier for nanodevices and disease diagnosis.

Structural and dynamic effects of paraoxon binding to human acetylcholinesterase by X-ray crystallography and inelastic neutron scattering

Organophosphorus (OP) compounds, including nerve agents and some pesticides, covalently bind to the catalytic serine of human acetylcholinesterase (hAChE), thereby inhibiting acetylcholine hydrolysis necessary for efficient neurotransmission. Oxime antidotes can reactivate the OP-conjugated hAChE, but reactivation efficiency can be low for pesticides, such as paraoxon (POX). Understanding structural and dynamic determinants of OP inhibition and reactivation can provide insights to design improved reactivators. Here, X-ray structures of hAChE with unaged POX, with POX and oximes MMB4 and RS170B, and with MMB4 are reported. A significant conformational distortion of the acyl loop was observed upon POX binding, being partially restored to the native conformation by oximes. Neutron vibrational spectroscopy combined with molecular dynamics simulations showed that picosecond vibrational dynamics of the acyl loop soften in the ∼20-50 cm-1 frequency range. The acyl loop structural perturbations may be correlated with its picosecond vibrational dynamics to yield more comprehensive template for structure-based reactivator design.

Electrostatic Contributions to the Binding Free Energy of Nicotine to the Acetylcholine Binding Protein

Biomolecular binding relies on specific attractive interactions between two partner molecules, including electrostatics, dispersion, hydrophobicity, and solvation. Assessing the contributions of electrostatic interactions to binding is key to the understanding of ligand binding mechanisms and the design of improved biomolecular binders. For example, nicotine is a well-known agonist of nicotinic acetylcholine receptors (nAChRs), but the molecular mechanisms for the differential action of nicotine on brain and muscle nAChRs remain elusive. In this work, we have chosen the acetylcholine binding protein (AChBP) in complex with nicotine as a model system to interrogate the electrostatic contributions to nicotine binding. Our absolute binding free energy simulations confirm that nicotine binds AChBP predominantly in its protonated (charged) form. By comparing energetic contributions from decomposed interactions for either neutral or charged nicotine, our calculations shed light on the nature of the binding of nicotine to the AChBP. The preferred binding of charged nicotine over neutral nicotine originates from its stronger electrostatic interactions with AChBP, a cation-π interaction to a tryptophan residue and a hydrogen bond between nicotine and the backbone carbonyl of the tryptophan, whereas the major force driving the binding process appears to be van der Waals interactions. The various nonelectrostatic terms can also indirectly modulate the electrostatic interactions through fine-tuning the binding pose of the ligand in the binding site, providing an explanation of why the binding specificity of nicotine to the brain versus muscle nAChRs is driven by electrostatic interaction, given that the immediate binding site residues, including the key tryptophan residue, are identical in the two receptors.

Nanomaterials-Mediated Co-Stimulation of Toll-Like Receptors and CD40 for Antitumor Immunity

Toll-like receptors (TLRs) and CD40-related signaling pathways represent critical bridges between innate and adaptive immune responses. Here, an immunotherapy regimen that enables co-stimulation of TLR7/8- and CD40-mediated pathways is developed. TLR7/8 agonist resiquimod (R848) derived amino lipids, RAL1 and RAL2, are synthesized and formulated into RAL-derived lipid nanoparticles (RAL-LNPs). The RAL2-LNPs show efficient CD40 mRNA delivery to DCs both in vitro (90.8 ± 2.7%) and in vivo (61.3 ± 16.4%). When combined with agonistic anti-CD40 antibody, this approach can produce effective antitumor activities in mouse melanoma tumor models, thereby suppressing tumor growth, prolonging mouse survival, and establishing antitumor memory immunity. Overall, RAL2-LNPs provide a novel platform toward cancer immunotherapy by integrating innate and adaptive immunity.

Refinement of SARS-CoV-2 envelope protein structure in a native-like environment by molecular dynamics simulations

COVID-19 has become an unprecedented threat to human health. The SARS-CoV-2 envelope (E) protein plays a critical role in the viral maturation process and pathogenesis. Despite intensive investigation, its structure in physiological conditions remains mysterious: no high-resolution full-length structure is available and only an NMR structure of the transmembrane (TM) region has been determined. Here, we present a refined E protein structure, using molecular dynamics (MD) simulations to investigate its structure and dynamics in a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayer system. Our initial homology model based upon the SARS-CoV E protein structure is shown to be unstable in the lipid bilayer, and the H3 helices tend to move away from the membrane center to the membrane-water interface. A more stable model was developed by replacing all H3 helices with the fully equilibrated H3 structure sampled in the MD simulations. This refined model exhibited more favorable contacts with lipids and water than the original homology model and induced local membrane curvature, decreasing local lipid order. Interestingly, the pore radius profiles showed that the channel in both homology and refined models remained in a closed state throughout the simulations. We also demonstrated the utility of this structure to develop anti-SARS-CoV-2 drugs by docking a library of FDA-approved, investigational, and experimental drugs to the refined E protein structure, identifying 20 potential channel blockers. This highlights the power of MD simulations to refine low-resolution structures of membrane proteins in a native-like membrane environment, shedding light on the structural features of the E protein and providing a platform for the development of novel antiviral treatments.

[Construction of prediction model combined dual-energy CT quantitative parameters and conventional CT features for assessing the Ki-67 expression levels in invasive breast cancer]

Objective: To develop a model combined with dual-energy CT quantitative parameters and conventional CT features for evaluating the expression level of Ki-67 in invasive breast cancer. Methods: A total of 191 patients with histologically confirmed invasive breast cancer in Lishui Central Hospital from March 2019 to December 2020, were retrospectively enrolled, all of them were females, aged from 25 to 77 (53.2±11.3) years. All patients underwent preoperative non-contrast chest and contrast-enhanced Dual energy CT scans, and the normalized iodine concentration (NIC) of lesions on arterial and venous phase, spectral curve slope (λ_HU), and normalized effective atomic number (nZ_eff) were measured and calculated, and their conventional CT characteristics were assessed. According to the results of immunohistochemistry (IHC), the patients were divided into Ki-67 high expression group (n=129 patients) and low expression group (n=62 patients) level. The differences in clinical data, conventional CT characteristics and dual-energy CT quantitative parameters between the two groups were analyzed. The receiver operating characteristic curve (ROC) curve was conducted to assess the efficacy of each individual model and joint model in evaluating Ki-67 expression levels, and the area under the curve (AUC), sensitivity, specificity, and accuracy were calculated, respectively. Results: In the analysis of CT features, the longest diameter, shape and enhancement pattern of the tumor were significantly difference between the two groups (all P<0.05). The NIC, nZ_eff on the arterial phase and NIC, nZ_eff and λ_HU [M(Q₁,Q₃)] on the venous phase were higher in the high Ki-67 expression group compared to the low expression group [0.13 (0.12, 0.16) vs 0.11 (0.08, 0.14), 0.71 (0.70, 0.75) vs 0.70 (0.67, 0.72), 0.40 (0.32, 0.48) vs 0.23 (0.17, 0.32), 3.10 (2.58, 3.63) vs 2.86 (2.19, 3.48), 0.88 (0.85, 0.92) vs 0.85 (0.84, 0.86), all P<0.05]. The logistic regression model, which integrated significant conventional CT features and dual-energy CT quantitative parameters, demonstrated the highest diagnostic performance for assessing Ki-67 expression levels, with an AUC of 0.924, sensitivity of 88.37%, specificity of 83.87%, and accuracy of 86.91%; the AUC of the dual-energy CT parameter model was 0.908, sensitivity of 82.17%, specificity of 88.71%, and accuracy of 84.29%. Though the diagnostic efficacy was no significant difference (P=0.238), both models showed superior to the conventional CT feature model (all P<0.001). Conclusion: A dual-energy CT quantitative parameter combined with a conventional CT feature model was successfully constructed, which has a good evaluation performance on the expression level of Ki-67 in invasive breast cancer.

Circulating myeloid-derived suppressors cells correlate with clinicopathological characteristics and outcomes undergoing neoadjuvant chemoimmunotherapy in non-small cell lung cancer

PURPOSE

Myeloid-derived suppressors cells (MDSCs) are heterogeneous immunosuppressive cells, closely related to the development, efficacy and prognosis in various tumors. The relationship between clinicopathological characteristics, efficacy of neoadjuvant chemoimmunotherapy (NCIO) and circulating MDSCs in patients with non-small cell lung cancer (NSCLC) was investigated in this study.

METHODS

This study analyzed the clinical data of patients diagnosed at Department of Thoracic Surgery, Beijing Chest Hospital from November 2020 to August 2021. MDSCs and T cells subgroups were measured in fresh peripheral blood mononuclear cells(PBMCs) at baseline. Flow cytometry was used to detect MDSCs and T cells subgroups.

RESULTS

A total of 78 patients with NSCLC and 20 patients with benign nodule underwent direct surgery. 23 patients with NSCLC scheduled to accept NCIO before surgery. NSCLC had elevated levels of total MDSCs, PMN-MDSCs and M-MDSCs compared to patients with benign nodule. MDSCs subgroups were correlated to the pTNM stage in NSCLC patients. The frequency of total MDSCs were moderately positively correlated with regulatory T cells (Tregs)(r = 0.3597, P < 0.01) and negatively correlated with CD4 + T cells(r = 0.2714, P < 0.05). The baseline levels of total MDSCs, PMN-MDSCs and Tregs in pCR patients were significantly decreased than those of non-pCR patients (P < 0.05).

CONCLUSION

Circulating MDSCs were increased in NSCLC patients. MDSC subgroups were related to pTNM stage in NSCLC patients. Total MDSCs were positively correlated with Tregs levels and negatively correlated with CD4 + T cells in peripheral blood. The level of MDSCs and Tregs in peripheral blood may have potential value in predicting pathological response in NSCLC.

[Role and mechanism of Vγ4 T cells in impaired wound healing of rapamycin-induced full-thickness skin defects in mice]

Objective: To investigate the role and mechanism of Vγ4 T cells in impaired wound healing of rapamycin-induced full-thickness skin defects in mice. Methods: The experimental research methods were applied. Eighty-six C57BL/6J male mice (hereinafter briefly referred to as wild-type mice) aged 8-12 weeks were selected for the following experiments. Vγ4 T cells were isolated from axillary lymph nodes of five wild-type mice for the following experiments. Intraperitoneal injection of rapamycin for 42 mice was performed to establish rapamycin-treated mice model for the following experiments. Eighteen wild-type mice were divided into normal control group without any treatment, trauma only group, and trauma+CC chemokine ligand 20 (CCL20) inhibitor group according to the random number table (the same grouping method below), with 6 mice in each group. The full-thickness skin defect wound was made on the back of mice in the latter two groups (the same wound model below), and mice in trauma+CCL20 inhibitor group were continuously injected subcutaneously with CCL20 inhibitor at the wound edge for 3 days after injury. Another 6 rapamycin-treated mice were used to establish wound model as rapamycin+trauma group. On post injury day (PID) 3, the epidermal cells of the skin tissue around the wound of each trauma mice were extracted by enzyme digestion, and the percentage of Vγ4 T cells in the epidermal cells was detected by flow cytometry. In normal control group, the epidermal cells of the normal skin tissue in the back of mice were taken at the appropriate time point for detection as above. Five wild-type mice were used to establish wound models. On PID 3, the epidermal cells were extracted from the skin tissue around the wound. The cell populations were divided into Vγ4 T cells, Vγ3 T cells, and γδ negative cells by fluorescence-activated cell sorter, which were set as Vγ4 T cell group, Vγ3 T cell group, and γδ negative cell group (with cells in each group being mixed with B16 mouse melanoma cells), respectively. B16 mouse melanoma cells were used as melanoma cell control group. The expression of interleukin-22 (IL-22) mRNA in cells of each group was detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR), with the number of samples being 6. Thirty rapamycin-treated mice were used to establish wound models, which were divided into Vγ4 T cell only group and Vγ4 T cell+IL-22 inhibitor group performed with corresponding injections and rapamycin control group injected with phosphate buffer solution (PBS) immediately after injury, with 10 mice in each group. Another 10 wild-type mice were taken to establish wound models and injected with PBS as wild-type control group. Mice in each group were injected continuously for 6 days. The percentage of wound area of mice in the four groups was calculated on PID 1, 2, 3, 4, 5, and 6 after injection on the same day. Six wild-type mice and 6 rapamycin-treated mice were taken respectively to establish wound models as wild-type group and rapamycin group. On PID 3, the mRNA and protein expressions of IL-22 and CCL20 in the peri-wound epidermis tissue of mice in the two groups were detected by real-time fluorescence quantitative RT-PCR and Western blotting, respectively. The Vγ4 T cells were divided into normal control group without any treatment and rapamycin-treated rapamycin group. After being cultured for 24 hours, the mRNA and protein expressions of IL-22 of cells in the two groups were detected by real-time fluorescence quantitative RT-PCR and Western blotting, respectively, with the number of samples being 6. Data were statistically analyzed with independent sample t test, analysis of variance for repeated measurement, one-way analysis of variance, Bonferroni method, Kruskal-Wallis H test, and Wilcoxon rank sum test. Results: The percentage of Vγ4 T cells in the epidermal cells of the skin tissue around the wound of mice in trauma only group on PID 3 was 0.66% (0.52%, 0.81%), which was significantly higher than 0.09% (0.04%, 0.14%) in the epidermal cells of the normal skin tissue of mice in normal control group (Z=4.31, P<0.01). The percentages of Vγ4 T cells in the epidermal cells of the skin tissue around the wound of mice in rapamycin+trauma group and trauma+CCL20 inhibitor group on PID 3 were 0.25% (0.16%, 0.37%) and 0.24% (0.17%, 0.35%), respectively, which were significantly lower than that in trauma only group (with Z values of 2.27 and 2.25, respectively, P<0.05). The mRNA expression level of IL-22 of cells in Vγ4 T cell group was significantly higher than that in Vγ3 T cell group, γδ negative cell group, and melanoma cell control group (with Z values of 2.96, 2.45, and 3.41, respectively, P<0.05 or P<0.01). Compared with that in wild-type control group, the percentage of wound area of mice in rapamycin control group increased significantly on PID 1-6 (P<0.01), the percentage of wound area of mice in Vγ4 T cell+IL-22 inhibitor group increased significantly on PID 1 and PID 3-6 (P<0.05 or P<0.01). Compared with that in rapamycin control group, the percentage of wound area of mice in Vγ4 T cell only group decreased significantly on PID 1-6 (P<0.05 or P<0.01). Compared with that in Vγ4 T cell only group, the percentage of wound area of mice in Vγ4 T cell+IL-22 inhibitor group increased significantly on PID 3-6 (P<0.05 or P<0.01). On PID 3, compared with those in wild-type group, the expression levels of IL-22 protein and mRNA (with t values of -7.82 and -5.04, respectively, P<0.01) and CCL20 protein and mRNA (with t values of -7.12 and -5.73, respectively, P<0.01) were decreased significantly in the peri-wound epidermis tissue of mice in rapamycin group. After being cultured for 24 hours, the expression levels of IL-22 protein and mRNA in Vγ4 T cells in rapamycin group were significantly lower than those in normal control group (with t values of -7.75 and -6.04, respectively, P<0.01). Conclusions: In mice with full-thickness skin defects, rapamycin may impair the CCL20 chemotactic system by inhibiting the expression of CCL20, leading to a decrease in the recruitment of Vγ4 T cells to the epidermis, and at the same time inhibit the secretion of IL-22 by Vγ4 T cells, thereby slowing the wound healing rate.

[Consensus of experts on the medical risk prevention for the patients with cardiovascular diseases during dental treatment (2022 edition)]

With the aging process of population in the society, the prevalence of cardiovascular diseases (CVD) in China is increasing continuously and the number of dental patients with CVD is increasing gradually too. Due to the lack of guidelines for dental patients with CVD in our country, how to implement standardized preoperative evaluation and perioperative risk prevention remains a problem to be solved for dentists at present. The present expert consensus was reached by combining the clinical experiences of the expert group of the Fifth General Dentistry Special Committee, Chinese Stomatological Association and respiratory and cardiology experts in diagnosis and treatment for CVD patients, and by systematically summarizing the relevant international guidelines and literature regarding the relationship between CVD and oral diseases and the diagnosis and treatment of dental patients with heart failure, hypertension and antithrombotic therapy. The consensus aims to provide, for the dental clinicians, the criteria on diagnosis and treatment of CVD in dental patients in China so as to reduce the risk and complications, and finally to improve the treatment levels of dental patients with CVD in China.

Ammonia stimulates SCAP/Insig dissociation and SREBP-1 activation to promote lipogenesis and tumour growth

Tumorigenesis is associated with elevated glucose and glutamine consumption, but how cancer cells can sense their levels to activate lipid synthesis is unknown. Here, we reveal that ammonia, released from glutamine, promotes lipogenesis via activation of sterol regulatory element-binding proteins (SREBPs), endoplasmic reticulum-bound transcription factors that play a central role in lipid metabolism. Ammonia activates the dissociation of glucose-regulated, N-glycosylated SREBP-cleavage-activating protein (SCAP) from insulin-inducible gene protein (Insig), an endoplasmic reticulum-retention protein, leading to SREBP translocation and lipogenic gene expression. Notably, 25-hydroxycholesterol blocks ammonia to access its binding site on SCAP. Mutating aspartate D428 to alanine prevents ammonia binding to SCAP, abolishes SREBP-1 activation and suppresses tumour growth. Our study characterizes the unknown role, opposite to sterols, of ammonia as a key activator that stimulates SCAP-Insig dissociation and SREBP-1 activation to promote tumour growth and demonstrates that SCAP is a critical sensor of glutamine, glucose and sterol levels to precisely control lipid synthesis.

[Pretreatment evaluation of 18F-FDG PET-CT in extranodal NK/T-cell lymphoma]

Objective: To investigate the clinical value of pretreatment ¹⁸F-fluorodeoxy glucose positron emission tomography/computed tomography (¹⁸F-FDG PET-CT) in extranodal NK/T-cell lymphoma. Methods: Eighty-one patients with pathologically confirmed extranodal NK/T-cell lymphoma and pretreatment with PET-CT scan in Cancer Hospital, Chinese Academy of Medical Sciences from August 2006 to December 2017 were enrolled in the study. The clinical, follow-up and imaging data were analyzed retrospectively. The relationship between maximum standard uptake value (SUV_max) and prognosis were evaluated by Mann-Whitney U test and Spearman rank correlation analysis. Results: Among the 81 patients, 98.8% (80/81) were upper aerodigestive tract (UAT) involved. Lesions at extra-UAT sites were detected in 7 cases, involving parotid gland (n=1), breast (n=1), spleen (n=1), pancreas (n=1), skin and subcutaneous soft tissue (n=1), muscle (n=1), lung (n=2) and bone (n=3). Lymph node involvement were demonstrated in 33 cases. All of the lesions had increased uptake of PET, the median SUV_max was 8.6. PET-CT changed staging in 15 cases, and 12 cases were adjusted treatment methods. 21 cases were changed radiotherapy target because of PET-CT. The 1-, 2-year progression-free survival (PFS) rates were 88.7% and 80.3% while 1-, 2-year overall survival (OS) rates were 97.2% and 94.4% respectively. The median SUV_max of patients with local lymph nodes involvement was significantly higher than those without local lymph nodes involvement (P=0.007). The SUV_max was positively associated with Ann Arbor stage (r=0.366, P=0.001), lactate dehydrogenase (r=0.308, P=0.005) and Ki-67 level (r=0.270, P=0.017). The SUV_max was inversely associated with lymphocyte count (r=-0.324, P=0.003) and hemoglobin content (r=-0.225, P=0.043). Conclusions: Extranodal NK/T-cell lymphoma predominantly occurs in extra-nodal organs, mainly in the upper respiratory and gastrointestinal tracts, with marked FDG-addiction. Compared with conventional imaging, ¹⁸F-FDG PET-CT is sensitive and comprehensive in detecting extra-nodal NK/T-cell lymphoma involvement, assisting in accurate clinical staging and treatment planning. Pretreatment SUV_max is potential for prognosis evaluation since it is correlated with prognostic factors.

Dual Functions of MDP Monomer with De- and Remineralizing Ability

Methacryloyloxydecyl dihydrogen phosphate (MDP) has been speculated to induce mineralization, but there has been no convincing evidence of its ability to induce intrafibrillar mineralization. Polymers play a critical role in biomimetic mineralization as stabilizers/inducers of amorphous precursors. Hence, MDP-induced biomimetic mineralization without polymer additives has not been fully verified or elucidated. By combining 3-dimensional stochastic optical reconstruction microscopy, surface zeta potentials, contact angle measurements, inductively coupled plasma-optical emission spectroscopy, transmission electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy with circular dichroism, we show that amphiphilic MDP can not only demineralize dentin by releasing protons as an acidic functional monomer but also infiltrate collagen fibrils (including dentin collagen), unwind the triple helical structure by breaking hydrogen bonds, and finally immobilize within collagen. MDP-bound collagen functions as a huge collagenous phosphoprotein (HCPP), in contrast to chemical phosphorylation modifications. HCPP can induce biomimetic mineralization itself without polymer additives by alternatively attracting calcium and phosphate through electrostatic attraction. Therefore, we herein propose the dual functions of amphiphilic MDP monomer with de- and remineralizing ability. MDP in the free state can demineralize dentin substrates by releasing protons, whereas MDP in the collagen-bound state as HCPP can induce intrafibrillar mineralization. The dual functions of MDP monomer with de- and remineralization properties might create a new epoch in adhesive dentistry and preventive dentistry.

[Investigating the effects of Modified Sijunzi Decoction on the diversity of intestinal microflora of severe scald rabbits based on 16S ribosomal RNA high-throughput sequencing]

Objective: To investigate the effects of Modified Sijunzi Decoction on the diversity of intestinal microflora of in severe scald rabbits based on 16S ribosomal RNA (16S rRNA) high-throughput sequencing. Methods: The experimental research method was adopted. Ninety Japanese big-ear rabbits regardless gender, aged 6 to 8 months, were randomly divided into normal control group, scald alone group, scald+low-dose group, scald+medium-dose group, and scald+high-dose group, with 18 rabbits in each group. The rabbits in normal control group were free to eat and drink, and the rabbits in scald alone group, scald+low-dose group, scald+medium-dose group, and scald+high-dose group were intragastrically administered normal saline, 0.2 g/mL Modified Sijunzi Decoction, 1.0 g/mL Modified Sijunzi Decoction, and 5.0 g/mL Modified Sijunzi Decoction, respectively for 7 days after sustaining full-thickness scalding of 30% total body surface area. On the 1st, 3rd, and 7th day after grouping, the levels of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-10 in ileal mucosa tissue of rabbits in each group were determined by enzyme-linked immunosorbent assay, and the number of samples in each group at each time point was 6. According to the above experimental results, another 9 rabbits were selected and divided into normal control group, scald alone group and scald+medium-dose group, with 3 rabbits in each group. The grouping and treatment methods of rabbits in each group were the same as before. On the 7th day after grouping, the V3, V4 region of 16S rRNA of ileum mucosa of rabbits in three groups were sequenced by high-throughput sequencing technology. The number of quality bacteria was counted by QIME software. The classifications of phylum, class, order, family and genus of microflora were analyzed by RDP Classifier software. The α diversity (Ace, Chao1, Simpson, and Shannon indexes) and β diversity were analyzed by Illumina MiSeq sequencing technology, and the number of experiment samples in each group was 3. Data were statistically analyzed with analysis for variance of factorial design, SNK test, and Bonferroni correction. Results: Compared with that in normal control group, the levels of TNF-α of ileal mucosa tissue of rabbits in scald alone group, scald+low-dose group, and scald+high-dose group on the 1st, 3rd, and 7th day after grouping and scald+medium-dose group on the 1st and 3rd day after grouping were all significantly increased (P<0.01), the levels of IL-1β in ileal mucosa tissue of rabbits in scald alone group, scald+low-dose group, scald+medium-dose group and scald+high-dose group on the 1st, 3rd, and 7th day after grouping were all significantly increased (P<0.05 or P<0.01), and the levels of IL-10 in ileal mucosa tissue of rabbits in scald alone group, scald+low-dose group, scald+medium-dose group, and scald+high-dose group on the 1st, 3rd, and 7th day after grouping were all significantly decreased (P<0.01). Compared with that in scald alone group, the levels of TNF-α in ileal mucosa tissue of rabbits in scald+low-dose group, scald+medium-dose group, and scald+high-dose group on the 3rd and 7th day after grouping, and scald+medium-dose group on the 1st day after grouping were all significantly decreased (P<0.01), and the levels of IL-1β in ileal mucosa tissue of rabbits in scald+low-dose group, scald+medium-dose group, and scald+high-dose group on the 3rd and 7th day after grouping and scald+medium-dose group on the 1st day after grouping were all significantly decreased (P<0.01), and the levels of IL-10 in ileal mucosa tissue of rabbits in scald+low-dose group on the 7th day after grouping and scald+medium-dose group on the 1st, 3rd, and 7th day after grouping and scald+high-dose group on the 3rd and 7th day after grouping were all significantly increased (P<0.05 or P<0.01). Compared with that in scald+low-dose group, the levels of TNF-α in ileal mucosa tissue of rabbits in medium-dose scald alone group on the 1st, 3rd, and 7th day after grouping and in high-dose scald alone group on the 3rd and 7th day after grouping were significantly decreased (P<0.01), and the levels of IL-1β in ileal mucosa tissue of rabbits in medium-dose scald alone group on the 1st, 3rd, and 7th day after grouping and in high-dose scald alone group on the 3rd and 7th day after grouping were all significantly decreased (P<0.05 or P<0.01), and the levels of IL-10 in ileal mucosa tissue of rabbits in scald+medium-dose group on the 1st, 3rd, and 7th day after grouping and in scald+high-dose group on the 7th day after grouping were all significantly increased (P<0.05 or P<0.01). Compared with that in scald medium-dose group, the levels of TNF-α in ileal mucosa tissue of rabbits in scald+high-dose group on the 1st, 3rd, and 7th day after grouping were all significantly increased (P<0.01), and the levels of IL-10 in ileal mucosa tissue of rabbits in scald+high-dose group on the 1st, 3rd, and 7th day after grouping were all significantly decreased (P<0.01), and the levels of IL-1β in ileal mucosa tissue of rabbits in scald+high-dose group on the 7th day after grouping was significantly decreased (P<0.01). Compared with that on the 1st day after grouping, the levels of TNF-α in ileal mucosa tissue of rabbits in scald alone group on the 3rd and 7th day after grouping and in normal control group on the 3rd day after grouping were all significantly increased (P<0.05 or P<0.01), and the levels of IL-1β in ileal mucosa tissue of rabbits in scald alone group both on the 3rd and 7th day after grouping were significantly increased (P<0.01), and the levels of IL-10 in ileal mucosa tissue of rabbits in both scald+low-dose group and scald+high-dose group on the 7th day after grouping and scald+medium-dose group both on the 3rd and 7th day after grouping were significantly increased (P<0.05 or P<0.01), and the levels of TNF-α in ileal mucosa tissue of rabbits in scald+high-dose group on the 3rd and 7th day after grouping and in scald+medium-dose group on the 7th day after grouping were all significantly decreased (P<0.05 or P<0.01), and the level of IL-1β in ileal mucosa tissue of rabbits in scald+medium-dose group on the 7th day after grouping was significantly decreased (P<0.01), and the level of IL-10 in ileal mucosa tissue of rabbits in scald alone group on the 7th day after grouping was significantly decreased (P<0.01). Compared with that on the 3rd day after grouping, the levels of TNF-α and IL-1β in ileal mucosa tissue of rabbits in scald alone group and the levels of IL-10 in ileal mucosa tissue of rabbits in normal control group, scald+low-dose group, scald+medium-dose group, and scald+high-dose group on the 7th day after grouping were all significantly increased (P<0.05 or P<0.01); and the levels of TNF-α in ileal mucosa tissue of rabbits in scald+low-dose group, scald+medium-dose group, and scald+high-dose group on the 7th day after grouping were all significantly decreased (P<0.05), and the levels of IL-1β in ileal mucosa tissue of rabbits both in scald+medium-dose group and scald+high-dose group on the 7th day after grouping were significantly decreased (P<0.05 or P<0.01), and the levels of IL-10 in ileal mucosa tissue of rabbits in scald alone group on the 7th day after grouping was significantly decreased (P<0.01). On the 7th day after grouping, the high-quality sequences obtained from the microflora in ileum mucosa of rabbits in normal control group, scald alone group, and scald+medium-dose group were 96 023, 107 365, and 95 921, respectively. At the classification level of phylum, class, order, family, and genus of the microflora in ileum mucosa of rabbits in three groups were all Bacteroidetes and Firmicutes, Clostridium and Bacteroidetes, Clostridium and Bacteroidetes, Rumenobacteriaceae and Clostridium and Bacteroideaceae, Clostridium and Bacteroidetes and rumen bacteria mainly, while the percentage of microflora in each group was different. There were no significant differences in Ace, Chao1, Simpson, Shannon indices (P>0.05), and no obvious difference in β diversity of microflora in ileal mucosa tissue of rabbits among three groups. Conclusions: After severe scalding, the inflammatory response of rabbit ileal mucosa tissue is obvious and increased in a time-dependent manner. Modified Sijunzi Decoction can reduce inflammation with optimal therapeutic concentration of 1.0 g/mL. The technology of high-throughput sequencing can reflect the structural composition of the intestinal microflora accurately. The ileal microflora of the severe scald rabbit can be regulated by the administration of Modified Sijunzi Decoction.

Treponema denticola Induces Alzheimer-Like Tau Hyperphosphorylation by Activating Hippocampal Neuroinflammation in Mice

Alzheimer's disease (AD) is the most common type of dementia. Tau hyperphosphorylation and amyloid β (Aβ) deposition are the key pathological hallmarks of AD. Recent studies have shown that periodontitis is a significant risk factor for AD. The periodontal pathogen Porphyromonas gingivalis and its virulence factors have been shown to initiate and promote the hallmark pathologies and behavioral symptoms of AD. A possible link between Treponema denticola, another main periodontal pathogen, and AD has been reported. However, the role of T. denticola in AD pathogenesis is still unclear, and whether T. denticola and P. gingivalis exert a synergistic effect to promote AD development needs to be further studied. In this study, we investigated whether oral infection with T. denticola caused tau hyperphosphorylation in the hippocampi of mice and explored the underlying mechanisms. Orally administered T. denticola induced alveolar bone resorption, colonized brain tissues, and increased the activity of the phosphokinase GSK3β by activating neuroinflammation in the hippocampus, thus promoting the hyperphosphorylation of the tau protein at Ser396, Thr181, and Thr231 in mice. An in vitro study with BV2 and N2a cell models of T. denticola invasion also verified the role of this pathogen in tau phosphorylation. T. denticola and P. gingivalis were not found to exert a synergistic effect on tau phosphorylation. In summary, these findings provide new insight into the important role of T. denticola in AD pathogenesis, providing biological connections between periodontal diseases and AD.

Effects of radial stress on piezoelectric ceramic tubes and transducers

Static analysis is performed for fiber windings to quantitatively control the radial stress at the outer radius of the piezoelectric ceramic tube. The radial stress is verified both experimentally and theoretically, and the dependence of the resonant and material properties of the piezoelectric ceramic tubes on the radial stress is clarified. The resonance frequencies and dielectric loss remain relatively stable, but the relative permittivity and the short circuit elastic constant decrease with the radial stress. The variations of the increased bandwidth and decreased electromechanical coupling coefficient (k₃₁), piezoelectric constant (d₃₁ and g₃₁), and mechanical quality factor (Q_m) are associated with the height-to-radius ratio. The properties of three cylindrical transducers applied with various radial stress show similar change tendencies, and a difference of 0.34 MPa radial stress results in a variation of approximately 13 in the bandwidth, 14 in Q_m, 15 in k₃₁, d₃₁, and g₃₁, and 16 in the amplitude of the first pulse. These results suggest that the consistency of the radial stress is essential, and it should be relatively small. These findings guide the design and preparation of the enhanced transducer.

In Vitro and In Vivo Inhibition of MATE1 by Tyrosine Kinase Inhibitors

The membrane transport of many cationic prescription drugs depends on facilitated transport by organic cation transporters of which several members, including OCT2 (SLC22A2), are sensitive to inhibition by select tyrosine kinase inhibitors (TKIs). We hypothesized that TKIs may differentially interact with the renal transporter MATE1 (SLC47A1) and influence the elimination and toxicity of the MATE1 substrate oxaliplatin. Interactions with FDA-approved TKIs were evaluated in transfected HEK293 cells, and in vivo pharmacokinetic studies were performed in wild-type, MATE1-deficient, and OCT2/MATE1-deficient mice. Of 57 TKIs evaluated, 37 potently inhibited MATE1 function by >80% through a non-competitive, reversible, substrate-independent mechanism. The urinary excretion of oxaliplatin was reduced by about 2-fold in mice with a deficiency of MATE1 or both OCT2 and MATE1 (p < 0.05), without impacting markers of acute renal injury. In addition, genetic or pharmacological inhibition of MATE1 did not significantly alter plasma levels of oxaliplatin, suggesting that MATE1 inhibitors are unlikely to influence the safety or drug-drug interaction liability of oxaliplatin-based chemotherapy.

[Analysis of the effect of microwave ablation in the treatment of small liver cancer]

Objective: To explore the clinical effect of microwave ablation in the treatment of early small liver cancer (≤3 cm). Methods: 103 cases with small liver cancer (tumor number < 3 and maximum tumor diameter < 3 cm) who underwent microwave ablation from November 2016 to November 2018 were retrospectively collected. The rate of residual lesions, recurrence rate one-year after the operation, and surgical complications were observed and grouped according to tumor size (< 2 cm and≥2 cm group) and tumor numbers (solitary and 2 ~ 3 lesion groups). The therapeutic effects of each group were compared and analyzed. Results: The tumor residual rate and one-year recurrence rate of small liver cancer after microwave ablation were 11.7% and 35.0%, respectively. The post-ablation syndrome incidence rate was 52.4%, with no serious adverse events. Compared with tumors < 2 cm, patients with≥2 cm had a higher postoperative residual rate (χ(2) = 7.651, P = 0.006), and the one-year recurrence rate of more solitary nodular tumors was lower (χ(2) = 10.125, P = 0.001). Conclusion: Microwave ablation is a safe and effective treatment for early small liver cancer, and it is more effective for small solitary nodules (< 2 cm).