A chimeric adenovirus-vectored vaccine based on Beta spike and Delta RBD confers a broad-spectrum neutralization against Omicron-included SARS-CoV-2 variants

Urgent research into innovative severe acute respiratory coronavirus-2 (SARS-CoV-2) vaccines that may successfully prevent various emerging emerged variants, particularly the Omicron variant and its subvariants, is necessary. Here, we designed a chimeric adenovirus-vectored vaccine named Ad5-Beta/Delta. This vaccine was created by incorporating the receptor-binding domain from the Delta variant, which has the L452R and T478K mutations, into the complete spike protein of the Beta variant. Both intramuscular (IM) and intranasal (IN) vaccination with Ad5-Beta/Deta vaccine induced robust broad-spectrum neutralization against Omicron BA.5-included variants. IN immunization with Ad5-Beta/Delta vaccine exhibited superior mucosal immunity, manifested by higher secretory IgA antibodies and more tissue-resident memory T cells (TRM) in respiratory tract. The combination of IM and IN delivery of the Ad5-Beta/Delta vaccine was capable of synergically eliciting stronger systemic and mucosal immune responses. Furthermore, the Ad5-Beta/Delta vaccination demonstrated more effective boosting implications after two dosages of mRNA or subunit recombinant protein vaccine, indicating its capacity for utilization as a booster shot in the heterologous vaccination. These outcomes quantified Ad5-Beta/Delta vaccine as a favorable vaccine can provide protective immunity versus SARS-CoV-2 pre-Omicron variants of concern and BA.5-included Omicron subvariants.

[Semiparametric analysis of nonparametric proportional hazards models with mixed dependent censored data]

OBJECTIVE

To construct a nonparametric proportional hazards (PH) model for mixed informative interval-censored failure time data for predicting the risks in heart transplantation surgeries.

METHODS

Based on the complexity of mixed informative interval-censored failure time data, we considered the interdependent relationship between failure time process and observation time process, constructed a nonparametric proportional hazards (PH) model to describe the nonlinear relationship between the risk factors and heart transplant surgery risks and proposed a two-step sieve estimation maximum likelihood algorithm. An estimation equation was established to estimate frailty variables using the observation process model. Ⅰ-spline and B-spline were used to approximate the unknown baseline hazard function and nonparametric function, respectively, to obtain the working likelihood function in the sieve space. The partial derivative of the model parameters was used to obtain the scoring equation. The maximum likelihood estimation of the parameters was obtained by solving the scoring equation, and a function curve of the impact of risk factors on the risk of heart transplantation surgery was drawn.

RESULTS

Simulation experiment suggested that the estimated values obtained by the proposed method were consistent and asymptotically effective under various settings with good fitting effects. Analysis of heart transplant surgery data showed that the donor's age had a positive linear relationship with the surgical risk. The impact of the recipient's age at disease onset increased at first and then stabilized, but increased against at an older age. The donor-recipient age difference had a positive linear relationship with the surgical risk of heart transplantation.

CONCLUSION

The nonparametric PH model established in this study can be used for predicting the risks in heart transplantation surgery and exploring the functional relationship between the surgery risks and the risk factors.

The severity of addiction mediates loneliness and cortical volume in internet gaming disorder

Internet gaming disorder (IGD) subjects reported higher loneliness scores than healthy controls. However, the neural correlates underlying the association between loneliness and IGD remain unclear. Thus, the aim of this study was to explore the relationship between loneliness, online gaming addiction and brain structure. In the current study, structural MRI data were acquired from 84 IGD subjects and 103 matched recreational game users (RGUs). We assessed and compared their addiction severity, loneliness scores, and cortical volumes and analyzed the correlations among these values. Significant correlations were found between loneliness scores and brain volumes in the postcentral cortex, the medial orbitofrontal cortex, the rostral anterior cingulate cortex, and the temporal cortex. In addition, the addiction severity scores partly mediated the relationship between loneliness score and cortical volume in IGD. The results showed that participants with extreme loneliness had significant correlations with brain regions responsible for executive control, social threat surveillance and avoidance. More importantly, the severity of addiction mediates loneliness and cortical volume. The findings shed new insight into the neural mechanisms of loneliness and IGD and have implications for potential treatment.

China Alzheimer's Disease and Neurodegenerative Disorder Research (CANDOR) -A Prospective Cohort Study for Alzheimer's Disease and Vascular Cognitive Impairment

BACKGROUND

Alzheimer's disease (AD) and vascular cognitive impairment (VCI) are the two main causes of dementia. AD and VCI share similar symptoms of cognitive decline and may be attributable to similar risk factors. Establishing a prospective cohort to compare VCI and AD would help to understand vascular risk factors related to dementia.

OBJECTIVES

China Alzheimer's disease and Neurodegenerative Disorder Research (CANDOR) study is a prospective multicenter cohort study. It aims to study the similarities and differences between AD and post stroke cognitive impairment (PSCI) in neuroimaging changes, disease progression, and multiple omics studies.

DESIGN

This is an ongoing study. From July 31, 2019, to August 1, 2022, we recruited 1449 participants with ages between 40 and 100 years. The cohort included three groups: AD group, PSCI group, and normal cognitive (NC) group. Data were collected in face-to-face interviews at baseline, and will be followed up every year for 4 years. The PSCI group had additional follow-ups at 3-month and 6-month after enrollment. Brain Magnetic Resonance Imaging (MRI) included high-resolution sequences for intracranial arteries. Cognitive assessments and follow-up information will be prospectively collected. Biological specimens including blood and urine at baseline were collected and tested.

PARTICIPANTS

The targeted sample size of PSCI group was 500, AD group with 600 and NC group with 2000. There were 1449 participants enrolled. Include 508 participants were in NC group, 387 in AD group and 554 in PSCI group.

MEASUREMENTS

Demographics, clinical parameters, and medical examinations were collected and performed. Cognitive assessment was performed to assess all cognitive domains including memory, language, executive function, and orientation function.

CONCLUSIONS

The CANDOR study is a prospective cohort study. Data from this cohort provide us an opportunity to investigate the contribution of vascular factors to dementia pathogenesis.

[Clonal hematopoiesis and its evolution of myeloproliferative neoplasms]

The mutations of myeloproliferative neoplasma (MPN) mainly include driver mutations and non-driver mutations. The driver mutations mainly include JAK2 mutations, CALR mutations and MPL mutations and non-driver mutations mainly include ASXL1, DNMT3A, TET2, SF3B1, EZH2, TP53, SRSF2, USAF1, etc. Driver and non-driver mutations and their clonal evolution affect the thrombosis and disease transformation of MPN. Clonal hematopoiesis of MPN can occur decades before diagnosis, even in the fetal stage. After the emergence of clonal hematopoiesis, until the emergence and progression of MPN, gene mutation order, inflammation, interferon therapy affect the disease phenotype and clonal hematopoiesis of MPN. Although great progress has been made in the understanding of MPN clonal hematopoiesis and its evolution with the development of next-generation sequencing, there are still many limitations. In this study, we mainly discuss gene mutations of MPN and their influences on the thrombosis, leukemia and fibrosis transformation, and the influencing factors of clonal evolution, aiming to summarize the influence of clonal hematopoiesis and its evolution on the complications, prognosis and survival of MPN.

Development of a bispecific nanobody conjugate broadly neutralizes diverse SARS-CoV-2 variants and structural basis for its broad neutralization

The continuous emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with increased transmissibility and profound immune-escape capacity makes it an urgent need to develop broad-spectrum therapeutics. Nanobodies have recently attracted extensive attentions due to their excellent biochemical and binding properties. Here, we report two high-affinity nanobodies (Nb-015 and Nb-021) that target non-overlapping epitopes in SARS-CoV-2 S-RBD. Both nanobodies could efficiently neutralize diverse viruses of SARS-CoV-2. The neutralizing mechanisms for the two nanobodies are further delineated by high-resolution nanobody/S-RBD complex structures. In addition, an Fc-based tetravalent nanobody format is constructed by combining Nb-015 and Nb-021. The resultant nanobody conjugate, designated as Nb-X2-Fc, exhibits significantly enhanced breadth and potency against all-tested SARS-CoV-2 variants, including Omicron sub-lineages. These data demonstrate that Nb-X2-Fc could serve as an effective drug candidate for the treatment of SARS-CoV-2 infection, deserving further in-vivo evaluations in the future.

Structural and functional basis of low-affinity SAM/SAH-binding in the conserved MTase of the multi-segmented Alongshan virus distantly related to canonical unsegmented flaviviruses

Alongshan virus (ALSV), a newly discovered member of unclassified Flaviviridae family, is able to infect humans. ALSV has a multi-segmented genome organization and is evolutionarily distant from canonical mono-segmented flaviviruses. The virus-encoded methyltransferase (MTase) plays an important role in viral replication. Here we show that ALSV MTase readily binds S-adenosyl-L-methionine (SAM) and S-adenosyl-L-homocysteine (SAH) but exhibits significantly lower affinities than canonical flaviviral MTases. Structures of ALSV MTase in the free and SAM/SAH-bound forms reveal that the viral enzyme possesses a unique loop-element lining side-wall of the SAM/SAH-binding pocket. While the equivalent loop in flaviviral MTases half-covers SAM/SAH, contributing multiple hydrogen-bond interactions; the pocket-lining loop of ALSV MTase is of short-length and high-flexibility, devoid of any physical contacts with SAM/SAH. Subsequent mutagenesis data further corroborate such structural difference affecting SAM/SAH-binding. Finally, we also report the structure of ALSV MTase bound with sinefungin, an SAM-analogue MTase inhibitor. These data have delineated the basis for the low-affinity interaction between ALSV MTase and SAM/SAH and should inform on antiviral drug design.

The Feasibility of Level Ib Sparing Intensity Modulated Radiation Therapy in Nasopharyngeal Carcinoma Patients with High-Risk Factors: Based on International Guideline

PURPOSE/OBJECTIVE(S)

In spite of the rarity of level Ib recurrence after intensity-modulated radiation therapy, the International Guideline (IG) provides the risk factors for prophylactic coverage. In practice, however, there are significant differences between institutions. The purpose of this study is to examine the feasibility of sparing level Ib IMRT in NPC patients with high-risk factors based on IG.

MATERIALS/METHODS

From January 2014 to October 2017, newly-diagnostic, non-metastatic NPC patients in our center were retrospectively reviewed. According to the risk factors of prophylactic level Ib coverage in patients with negative level Ib recommended by IG, the characteristics of pre-treatment MRI were analyzed. Four high-risk factors were identified: a. involvement of the structures that drain to level Ib as first echelon (FES), including anterior half of nasal cavity, oral cavity, b. involvement of submandibular gland (SMG), c. with radiologic extranodal extension (rENE) in level II LNs, or d. maximal axial diameter (MAD)≧2 cm in level II LNs. Patients with risk factors were divided into Cohort A (with risk factors a), Cohort B (with risk factor b, but without a), and Cohort C (only with risk factors c and/or d). Recurrence rates of level Ib and regional relapse-free survival (RRFS) rates were evaluated in different cohorts.

RESULTS

A total of 961 patients were finally included. Thirty-six cases (3.7%) presented with radiologically positive level Ib metastasis. For the other patients with negative Ib LNs, there were 18, 65, 421, and 444 cases classified as FES involvement, SMG involvement, level II LNs with rENE, and level II nodal with MAD ≧2 cm. Excluding overlap, a total of 571 patients with risk factors were divided into three groups: Cohort A (n = 18), Cohort B (n = 49) and Cohort C (n = 504). Nine patients (9/961, 0.94%) developed level Ib recurrence. Except for 1 patient with positive Ib LNs at diagnosis, 2 did not meet any of the risk factors, while the other six (6/9, 66.7%) met at least one risk factor. The rate of recurrence at neck level Ib was highest in Cohort A (11.1%, 2/18; Ib-sparing group: 0/10, 0.0% vs Ib-covering group: 2/8, 25.0%; P = 0.183). In Cohort B, no cases were found with level Ib recurrence (0.0%, 0/49). In Cohort C, the rates were rare (0.8%, 4/504) in both groups (0.7%, 2/276 vs 0.9%, 2/228; P > 0.999). Among the three Cohorts, there were no significant differences in 5-year RRFS between two groups, which were 90.0% vs 62.5% (p = 0.248), 90.9% vs 92.0% (p = 0.905), and 92.6% vs 90.1% (p = 0.445), respectively. Among patients with high-risk factors, the incidence of grade 3-4 late dry mouth symptom was higher in the level Ib-covering group (3.1% vs 7.5%, P = 0.033).

CONCLUSION

Level Ib sparing appears safe and feasible for NPC patients with negative level Ib LNs, even if combined with risk factors: SMG involvement, and/or level II with rENE, and/or level II MAD ≧2 cm. Level Ib-sparing irradiation reduces dry mouth symptoms compared with level Ib-irradiation.

Unique T-cell Sub-Population Shifts after SBPT and Nivolumab in Platinum Refractory HNC: Biomarker Correlates from ROR1771

PURPOSE/OBJECTIVE(S)

ROR1771 was a clinical trial investigating the use of stereotactic body proton radiotherapy (SBPT) and nivolumab in recurrent platinum refractory head and neck squamous cell carcinoma (HNSCC). The planned analysis of T-cell subpopulation and biomarker response is herein presented.

MATERIALS/METHODS

Patients with metastatic histologically confirmed HNSCC from any primary site received 2 cycles of nivolumab followed by SBPT to 1-2 selected target lesion(s) (hilar/lung: 8 of 12 patients), followed by maintenance nivolumab. Peripheral blood mononuclear cells were isolated pre-/post-treatment. Flow cytometry identified T-cell subpopulations. Single Cell 5' Gene Expression (GEX) and V(D)J T Cell Receptor libraries were prepared using Single Cell Immune Profiling. Seurat (v4.1.1) was used to identify cell type clusters, and differential expression post-filtration was evaluated using the Wilcoxon Rank Sum test.

RESULTS

A total of 12 patients were eligible for analysis, with one alive at time of analysis, 52 months from start of treatment. Median overall survival here was 12.5 months vs. 7.5-months on CheckMate 141. SBPT ranged from 35-50 Gy. Sequential changes in T-cell populations from baseline were noted with initiation of nivolumab, driving decrease in tumor-reactive (TTR; CD11ahighPD1+CD8+), central memory (TCM; CCR7+CD45RA-), and effector T-cells (TEF; CCR7-CD45RA-). TTR and TCM increased following SBPT, with greatest increase (3.5x TTR and 5.2x TCM) in the surviving patient. An average of 68 genes with significant differential expression between timepoints (p<0.0001) demonstrated RNA gene expression changes across all cell subtypes, including ribosomal (RPL and RPS) genes, ACTB, FTL, MALAT1, and others. This averaged 113 genes across all timepoints in the surviving patient, with peak following nivolumab induction. On T-cell receptor (TCR) analysis of this patient, the predominant clonotype diversity changed substantially following nivolumab. Following SBPT, clonotype diversity again changed to include a milieu seen neither at baseline nor with nivolumab alone. These TCRs persisted for approximately 2 weeks following SBPT before returning to resemble the nivolumab-induced TCR diversity alone, coinciding with disease recurrence.

CONCLUSION

ROR1771 demonstrated overall survival favorably comparable to CheckMate 141. Biomarker analysis of peripheral blood samples demonstrated significant shifts in T-cell subpopulations and underlying gene expression to nivolumab and then to SBPT administration. SBPT to a target lesion changed TCR clonotypes within the peripheral blood beyond those seen with nivolumab administration, with fading of these TCR clonotypes coinciding with recurrence. SBPT in combination with nivolumab may drive systemic immunologic change above that induced by nivolumab alone and warrants further investigation.

Cryo-EM structures of human GPR34 enable the identification of selective antagonists

GPR34 is a functional G-protein-coupled receptor of Lysophosphatidylserine (LysoPS), and has pathogenic roles in numerous diseases, yet remains poorly targeted. We herein report a cryo-electron microscopy (cryo-EM) structure of GPR34 bound with LysoPS (18:1) and Gi protein, revealing a unique ligand recognition mode with the negatively charged head group of LysoPS occupying a polar cavity formed by TM3, 6 and 7, and the hydrophobic tail of LysoPS residing in a lateral open hydrophobic groove formed by TM3-5. Virtual screening and subsequent structural optimization led to the identification of a highly potent and selective antagonist (YL-365). Design of fusion proteins allowed successful determination of the challenging cryo-EM structure of the inactive GPR34 complexed with YL-365, which revealed the competitive binding of YL-365 in a portion of the orthosteric binding pocket of GPR34 and the antagonist-binding-induced allostery in the receptor, implicating the inhibition mechanism of YL-365. Moreover, YL-365 displayed excellent activity in a neuropathic pain model without obvious toxicity. Collectively, this study offers mechanistic insights into the endogenous agonist recognition and antagonist inhibition of GPR34, and provides proof of concept that targeting GPR34 represents a promising strategy for disease treatment.

Lipid-Polymer Hybrid Nanoparticles with Both PD-L1 Knockdown and Mild Photothermal Effect for Tumor Photothermal Immunotherapy

In developing countries, the incidence of colorectal cancer (CRC) is on the rise. The combination of programmed cell death ligand-1 (PD-L1) siRNA (siPD-L1) and mild photothermal therapy (PTT) is a promising strategy for CRC treatment. In this study, dopamine-modified polyethylenimine (PEI) was prepared to fabricate an IR780 and siPD-L1 codelivery lipid-polymer hybrid nanoparticle (lip@PSD-siP) for the photothermal immunotherapy of CRC. The modification of dopamine can significantly reduce the cytotoxicity of PEI. lip@PSD-siP can be effectively taken up by CT26 cells and successfully escaped from lysosomes after entering the cells for 4 h. After CT26 cells were transfected with lip@PSD-siP, the PD-L1 positive cell rate decreased by 82.4%, and its PD-L1 knockdown effect was significantly stronger than the positive control Lipo3000-siP. In vivo studies showed that lip@PSD-siP-mediated mild PTT and efficient PD-L1 knockdown exhibited primary and distal tumor inhibition, metastasis delay, and rechallenged tumor inhibition. The treatment with lip@PSD-siP significantly promoted the maturation of dendritic cells in lymph nodes. The amount of T cell infiltration in the tumor tissues increased significantly, and the frequency of CD8+ T cells and CD4+ T cells was significantly higher than that of other groups. The percentage of immunosuppressive regulatory cells (Tregs) in the tumor tissue on the treatment side decreased by 88% compared to the PBS group, and the proportion of CD8+CD69+ T cells in the distal tumor tissue was 2.8 times that of the PBS group. The memory T cells of mice in the long-term antitumor model were analyzed. The results showed that after treatment with lip@PSD-siP, the frequency of effector memory T cells (Tem cells) significantly increased, suggesting the formation of immune memory.

Cryo-EM structure of the nucleocapsid-like assembly of respiratory syncytial virus

Respiratory syncytial virus (RSV) is a nonsegmented, negative strand RNA virus that has caused severe lower respiratory tract infections of high mortality rates in infants and the elderly, yet no effective vaccine or antiviral therapy is available. The RSV genome encodes the nucleoprotein (N) that forms helical assembly to encapsulate and protect the RNA genome from degradation, and to serve as a template for transcription and replication. Previous crystal structure revealed a decameric ring architecture of N in complex with the cellular RNA (N-RNA) of 70 nucleotides (70-nt), whereas cryo-ET reconstruction revealed a low-resolution left-handed filament, in which the crystal monomer structure was docked with the helical symmetry applied to simulate a nucleocapsid-like assembly of RSV. However, the molecular details of RSV nucleocapsid assembly remain unknown, which continue to limit our complete understanding of the critical interactions involved in the nucleocapsid and antiviral development that may target this essential process during the viral life cycle. Here we resolve the near-atomic cryo-EM structure of RSV N-RNA that represents roughly one turn of the helical assembly that unveils critical interaction interfaces of RSV nucleocapsid and may facilitate development of RSV antiviral therapy.

[Association between volatile organic compounds and mortality risk of stroke]

Objective: To investigate the effect of volatile organic compounds (VOCs) exposure in the atmosphere on the risk of daily death from stroke in Guangzhou. Methods: Daily average concentrations of twelve atmospheric VOCs, meteorological factors, and daily deaths for stroke and its subtypes (including ischemic and hemorrhagic stroke) in Guangzhou from 2020 to 2021 were collected. The time-series Poisson generalized additive model was established to analyze the relationship between daily average concentrations of atmospheric VOCs and daily mortality from a stroke on different lag days. The season, gender, and age group further performed stratification analysis. Results: Toluene and n-pentane were associated with a higher mortality risk from stroke and its subtypes. For each interquartile range (IQR) increment in toluene concentration at lag0- 1 days, the RRs for mortality from stroke and hemorrhagic stroke were 1.060 (95%CI: 1.036-1.085) and 1.071 (95%CI: 1.030-1.113), respectively. For each IQR increment in n-pentane concentration, the RR for mortality from ischemic stroke was 1.064 (95%CI: 1.030-1.099). The effect estimates of VOCs may be higher during the cold season and among women and people aged ≥75 years. For each IQR increment in toluene concentration, the RRs for mortality risk of stroke in the cold season and women were 1.099 (95%CI: 1.056-1.143) and 1.085 (95%CI: 1.050-1.120), respectively. For n-pentane, the RR for death risk of stroke in people aged ≥75 years old was 1.072 (95%CI: 1.036-1.109). Results of sensitivity analysis showed that the effect estimates fluctuated less when PM2.5 and O3 were separately introduced for the two-pollutant model, as well as changing the degrees of freedom for covariates. Conclusions: This study suggests that VOCs may be an independent risk factor for daily mortality from stroke. Moreover, Toluene presented the most significant health impact.

Development and validation of a multiphase CT radiomics nomogram for the preoperative prediction of lymphovascular invasion in patients with gastric cancer

AIM

To develop a nomogram to predict lymphovascular invasion (LVI) in gastric cancer by integrating multiphase computed tomography (CT) radiomics and clinical risk factors.

MATERIALS AND METHODS

One hundred and seventy-two gastric cancer patients (121 training and 51 validation) with preoperative contrast-enhanced CT images and clinicopathological data were collected retrospectively. The clinical risk factors were selected by univariate and multivariate regression analysis. Radiomic features were extracted and selected from the arterial phase (AP), venous phase (VP), and delayed phase (DP) CT images of each patient. Clinical risk factors, radiomic features, and integration of both were used to develop the clinical model, radiomic models, and nomogram, respectively.

RESULTS

Radiomic features from AP (n=6), VP (n=6), DP (n=7) CT images and three selected clinical risk factors were used for model development. The nomogram showed better performance than the AP, VP, DP, and clinical models in the training and validation datasets, providing areas under the curves (AUCs) of 0.890 (95% CI: 0.820-0.940) and 0.885 (95% CI:0.765-0.957), respectively. All models indicated good calibration, and decision curve analysis proved that the net benefit of the nomogram was superior to that of the clinical and radiomic models throughout the vast majority of the threshold probabilities.

CONCLUSIONS

The nomogram integrating multiphase CT radiomics and clinical risk factors showed favourable performance in predicting LVI of gastric cancer, which may benefit clinical practice.

[Analysis of curative effect and short-term survival rate of plasma exchange and double plasma molecular adsorption combined with half-volume plasma exchange in the treatment of liver failure]

Objective: To investigate how plasma exchange (PE) and double plasma molecular adsorption combined with half-volume plasma exchange (DPMAS + half-volume PE) affect the curative effect and short-term survival rate in liver failure. Methods: Data from 181 cases of liver failure caused by different etiologies from January 1, 2017 to September 31, 2020, were selected. Patients were divided into a PE treatment alone group and a DPMAS + half-dose PE treatment group. The laboratory indicators with different models of artificial liver before and after treatment and the survival rates of 7, 14, 28, and 90 days after discharge were observed in the two groups. Measurement data were analyzed by t-tests and rank sum tests. Categorical data were analyzed by χ (2) test. Results: Non-biological artificial liver therapy with different models improved the liver and coagulation function in the two groups of patients with liver failure (P < 0.05 in PTA% intra-group). The coagulation function was significantly improved in the PE treatment alone group compared with that in the DPMAS + half-dose PE group [PT after treatment: (20.15 ± 0.88) s in the PE treatment alone group, (23.43 ± 1.02) s, t = -2.44, P = 0.016 in the DPMAS+half-dose PE group; PTA: 44.72% ± 1.75% in the PE treatment alone group, 35.62% ± 2.25%, t = 3.215 P = 0.002 in the DPMAS + half-dose PE group]. Bilirubin levels were significantly decreased in the DPMAS+half-dose PE group compared to the PE treatment alone group [total bilirubin after treatment: (255.30 ± 15.64) μmol/L in the PE treatment alone group, (205.46 ± 9.03) μmol/L, t = 2.74, P = 0.07 in the DPMAS + half-dose PE group; direct bilirubin after treatment: (114.74 ± 7.11) μmol/L in the PE treatment alone group, (55.33 ± 3.18) μmol/L, t = 7.54, P < 0.001) in the DPMAS + half-dose PE group]. However, there was no significant effect on leukocytes and neutrophils after treatment with different models of artificial liver (P > 0.05) in the two groups, and platelets decreased after treatment, with no statistically significant difference between the groups (t = -0.15, P = 0.882). The inflammatory indexes of the two groups improved after treatment with different models of artificial liver (P < 0.05], and the 28 and 90 d survival rates were higher in the DPMAS+half-dose PE group than those of the PE treatment alone group (28 d: 60.3% vs. 75.0%, χ (2) = 4.315, P = 0.038; 90 d: 56.2% vs. 72.5%. χ (2) = 10.355 P < 0.001). DPMAS + half-dose PE group plasma saving was 1385 ml compared with PE treatment alone group (Z = -7.608, P < 0.05). Conclusion: Both DPMAS+half-dose PE and PE treatment alone have a certain curative effect on patients with liver failure. In DPMAS+half-dose PE, the 28-day survival rate is superior to PE treatment alone, and it saves plasma consumption and minimizes blood use in clinic.

[Analysis of clinicopathological features of 18 cases of hepatic angiosarcoma]

Objective: To investigate the clinicopathological features, treatment, and prognosis of hepatic angiosarcoma. Methods: Clinicopathological data and prognostic conditions of 18 cases with hepatic angiosarcoma were collected retrospectively. The recurrence-free survival rate and overall survival rate were calculated by the Kaplan-Meier method. A Cox regression analysis was used to explore the survival-related risk factors. Results: There were 12 male and 6 female patients, with an average age of 57 (37 ~ 70) years. The tumor's average diameter was 8.40 (2.00 ~ 18.00) cm. Seven cases had multiple tumors, while two cases had large vessel tumor thrombuses. Microscopically, the tumor tissues were irregularly anastomosed, with vascular lacunar or solid bundle-like weaving, and the tissue morphology mimicked capillary hemangioma, cavernous hemangioma, or angioepithelioma, while tumor cells were spindle-shaped or epithelioid, lined with hobnails in the lumen, or formed papillary structures in the lumen. The proportion of highly, moderately, and poorly differentiated tumors was 4:8:6, with six cases having clear tumor boundaries, eight having microvascular tumor thrombi, and sixteen having blood lake formation. Different levels of expression of CD31, CD34, erythroblast transformation-specific related genes, and Fli-1 markers were demonstrated in all of the cases. Four cases had a P53 mutation, and six cases had Ki-67 > 10%. During the follow-up period of 0.23-114.20 months, the five-year recurrence-free survival rate and overall survival rate were 16.7% and 37.2%, respectively. Cox regression multivariate analysis showed that preoperative symptoms and multiple tumors were significant risk factors for recurrence-free survival, while preoperative symptoms and Ki-67 > 10% were significant risk factors for overall survival. Conclusion: Hepatic angiosarcoma is a rare hepatic mesenchymal tumor with high malignancy and a poor prognosis. Pathological morphology and immunohistochemical marker combinations are needed for a definite diagnosis. However, the complexity of angiosarcomas' histological and cytological conformations and the overlap of pathological features with benign vascular tumors, sarcomas, and carcinomas pose difficulties in the differential diagnosis. Thus, the only effective ways to prolong survival are early detection and radical surgical resection.

[Value of Improved Mayo Endoscopic Score for evaluating treatment efficacy for active ulcerative colitis]

OBJECTIVE

To assess the value of Improved Mayo Endoscopic Score (IMES) for evaluation of treatment efficacy for active ulcerative colitis (UC).

METHODS

We retrospectively analyzed the clinical and endoscopic data of 103 patients diagnosed with active UC in Beijing Tsinghua Changgung Hospital from January, 2015 to December, 2020. The severity of endoscopic lesions was determined by Mayo Endoscopic Score and the Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and the area of the endoscopic lesions was evaluated based on the Montreal classification system. The IMES was established by combining the MES with the Montreal classification.

RESULTS

Univariate analysis suggested that young patients (<40 years old), patients with extensive disease type (E3), patients with high endoscopic scores (MES=3, UCEIS>4, and IMES>4), and patients receiving advanced drug therapy (with systemic hormones, immunosuppressants, immunomodulators, and biological agents, etc.) had lower clinical and endoscopic remission rates. COX survival analysis showed that IMES≤4 was an independent risk factor for clinical and endoscopic remission. ROC curve indicated that the predictive value of IMSE≤4 for clinical and endoscopic remission (AUC=0.7793 and 0.7095, respectively; P<0.01) was better than that of Montreal (AUC=0.7357 and 0.6847, respectively; P<0.01), MES=2 (AUC=0.6671 and 0.5929, respectively; P<0.01), and UCEIS≤4 (AUC=0.6823 and 0.6459, respectively; P<0.01); IMES=5 had a better predictive value for patients with active UC undergoing colectomy tham E3 and MES=3.

CONCLUSION

IMES has good value in evaluating treatment efficacy for active UC.

Enhancement of blue and ultraviolet components in PCF-based supercontinuum generation through inter-modal dispersive-wave radiation

Broadband supercontinuum (SC) light sources generated through nonlinear effects in solid-core photonic crystal fibers (PCFs) have been widely used in spectroscopy, metrology, and microscopy, leading to great application successes. The short-wavelength extension of such SC sources, a longstanding challenge, has been the subject of intensive study over the past two decades. However, the exact mechanism of blue and ultraviolet light generation, especially for some resonance spectral peaks in the short-wavelength regime, is not yet fully understood. Here, we demonstrate that the effect of inter-modal dispersive-wave radiation, which results from phase matching between pump pulses at the fundamental optical mode and packets of linear waves at some higher-order modes (HOMs) propagating in the PCF core, might be one of the critical mechanisms that can result in some resonance spectral components with wavelengths much shorter than that of the pump light. We observed in an experiment that several spectral peaks resided in the blue and ultraviolet regimes of the SC spectrum, whose central wavelengths can be tuned by varying the PCF-core diameter. These experimental results can be interpreted well using the inter-modal phase-matching theory, providing some useful insights into the SC generation process.

Structural basis of BAM-mediated outer membrane β-barrel protein assembly

The outer membrane structure is common in Gram-negative bacteria, mitochondria and chloroplasts, and contains outer membrane β-barrel proteins (OMPs) that are essential interchange portals of materials1-3. All known OMPs share the antiparallel β-strand topology4, implicating a common evolutionary origin and conserved folding mechanism. Models have been proposed for bacterial β-barrel assembly machinery (BAM) to initiate OMP folding5,6; however, mechanisms by which BAM proceeds to complete OMP assembly remain unclear. Here we report intermediate structures of BAM assembling an OMP substrate, EspP, demonstrating sequential conformational dynamics of BAM during the late stages of OMP assembly, which is further supported by molecular dynamics simulations. Mutagenic in vitro and in vivo assembly assays reveal functional residues of BamA and EspP for barrel hybridization, closure and release. Our work provides novel insights into the common mechanism of OMP assembly.

[Exploration of making removable partial denture by digital technology]

To explore the digital manufacturing process of distal extension removable partial denture. From November 2021 to December 2022, 12 patients (7 males and 5 females) with free-ending situation were selected from the Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University. Three-dimensional model of the relationship between alveolar ridge and jaw position was obtained by intraoral scanning technique. After routine design, manufacturing and try-in of metal framework for removable partial denture, the metal framework was located in the mouth and scanned again to obtain the composite model of dentition, alveolar ridge and metal framework. The free-end modified model is obtained by merging the digital model of free-end alveolar ridge with the virtual model with the metal framework. The three-dimensional model of artificial dentition, and base plate was designed on the free-end modified model, and the resin model were made by digital milling technology. The removable partial denture was made by accurately positioning the artificial dentition and base plate, bonding metal framework with injection resin, grinding and polishing the artificial dentition and resin base. Compared with the design data after clinical trial, the results showed that there was an error of 0.4-1.0 mm and an error of 0.03-0.10 mm in the connection between the resin base of artificial dentition and the connecting rod of the in-place bolt and the connection between artificial dentition and resin base. After denturen delivery, only 2 patients needed grinding adjustment in follow-up visit due to tenderness, and the rest patients did not find any discomfort. The digital fabrication process of removable partial denture used in this study can basically solve the problems of digital fabrication of free-end modified model and assembly of artificial dentition with resin base and metal framework.

Dexmedetomidine-mediated neuroprotection against sevoflurane-induced brain development abnormality in fetal mice brain

OBJECTIVE

Brain development is susceptible to external influences during the gestation period so the neurotoxicity of anesthetics has gained a lot of attention. We aimed to investigate the neurotoxicity of sevoflurane to fetal mice brain as well as the neuroprotective effects of dexmedetomidine.

MATERIALS AND METHODS

Pregnant mice were treated with 2.5% sevoflurane for 6 hours. The changes in fetal brain development were assayed with immunofluorescence and western blot. The pregnant mice were intraperitoneally injected with dexmedetomidine or vehicle from gestation day (G) 12.5 to G15.5.

RESULTS

Our results showed maternal sevoflurane exposure could not only inhibit neurogenesis but also lead to precocious generation of astrocytes in fetal mice brains. The fetal mice brain of sevoflurane group exhibited a significant inhibition in the activity of Wnt signaling and the expression of CyclinD1, Ngn2. Chronic dexmedetomidine administration could minimize the negative effects caused by sevoflurane by activating the Wnt signaling pathway.

CONCLUSIONS

This study has uncovered a Wnt signaling-related mechanism of the neurotoxicity of sevoflurane and confirmed the neuroprotective effect of dexmedetomidine, which could provide pre-clinical evidence for clinical decision-making.

High Electron Mobility Hot-Exciton Induced Delayed Fluorescent Organic Semiconductors

The development of high mobility emissive organic semiconductors is of great significance for the fabrication of miniaturized optoelectronic devices, such as organic light emitting transistors. However, great challenge exists in designing key materials, especially those who integrates triplet exciton utilization ability. Herein, dinaphthylanthracene diimides (DNADIs), with 2,6-extended anthracene donor, and 3'- or 4'-substituted naphthalene monoimide acceptors were designed and synthesized. By introducing acceptor-donor-acceptor structure, both materials show high electron mobility. Moreover, by fine-tuning of substitution sites, good integration with high solid state photoluminescence quantum yield of 26 %, high electron mobility of 0.02 cm²  V^-1  s^-1 , and the feature of hot-exciton induced delayed fluorescence were obtained in 4'-DNADI. This work opens a new avenue for developing high electron mobility emissive organic semiconductors with efficient utilization of triplet excitons.

Deficient dynamics of prefrontal-striatal and striatal-default mode network (DMN) neural circuits in internet gaming disorder

BACKGROUND

Studies have proven that individuals with internet gaming disorder (IGD) show impaired cognitive control over game craving; however, the neural mechanism underlying this process remains unclear. Accordingly, the present study aimed to investigate the dynamic features of brain functional networks of individuals with IGD during rest, which have barely been understood until now.

METHODS

Resting-state fMRI data were collected from 333 subjects (123 subjects with IGD (males/females: 73/50) and 210 healthy controls (males/females: 135/75)). First, the data-driven methodology, named co-activation pattern analysis, was applied to investigate the dynamic features of nucleus accumbens (the core region involved in craving/reward processing and addiction)-centered brain networks in IGD. Further, machine learning analysis was conducted to investigate the prediction effect of the dynamic features on participants' addiction severity.

RESULTS

Compared to controls, subjects in the IGD group showed decreased resilience, betweenness centrality and occurrence in the prefrontal-striatal neural circuit, and decreased in-degree in the striatal-default mode network (DMN) circuit. Moreover, these decreased dynamic features could significantly predict participants' addiction severity.

LIMITATIONS

The causal relationship between IGD and the abnormal dynamic features cannot be identified in this study. All the subjects were university students.

CONCLUSIONS

The present results revealed the underlying brain networks of uncontrollable craving and game-seeking behaviors in individuals with IGD during rest. The decreased dynamics of the prefrontal-striatal and striatal-DMN neural circuits might be potential biomarkers for predicting the addiction severity of IGD and potential targets for effective interventions to reduce game craving of this disorder.

[Impact of interventional therapy on top of standard drug therapy on left ventricular structure and function in HFrEF patients complicating with middle aortic syndrome caused by Takayasu arteritis]

Objective: To evaluate the impact of interventional therapy on top of drug therapy on cardiac function and structure in heart failure with reduced ejection fraction (HFrEF) patients complicating with middle aortic syndrome caused by Takayasu arteritis (TA-MAS). Methods: It was a retrospective longitudinal study. The data of patients with TA-MAS and HFrEF, who received interventional therapy on top of drug therapy in Fuwai Hospital from January 2010 to September 2020, were collected and analyzed. Baseline clinical data (including demographic data, basic treatment, etc.) were collected through the electronic medical record system. Changes of indexes such as New York Heart Association (NYHA) classification, N-terminal pro-brain natriuretic peptide (NT-proBNP), left ventricular end diastolic diameter (LVEDD), left ventricular ejection fraction (LVEF), left ventricular mass index (LVMI) before and after therapy were analyzed. Results: A total of 10 patients were collected. There were 8 females in this patient cohort, age was (18.4±5.0) years and onset age was (15.3±5.0) years. All 10 patients received standard heart failure medication therapy in addition to hormone and/or immunosuppressive anti-inflammatory therapy, but cardiac function was not improved, so aortic balloon dilatation and/or aortic stenting were performed in these patients. The median follow-up was 3.3(1.3, 5.6) years. On the third day after interventional therapy, the clinical symptoms of the 10 patients were significantly improved, NYHA classfication was restored from preoperative Ⅲ/Ⅳ to Ⅱ at 6 months post intervention(P<0.05). Compared with preoperation, NT-proBNP (P=0.028), LVEDD (P=0.011) and LVMI (P=0.019) were significantly decreased, LVEF was significantly increased (P<0.001) at 6 months after operation. Compared with preoperation, NT-proBNP (P=0.016), LVEDD (P=0.023) and LVMI (P=0.043) remained decreased, LVEF remained increased (P<0.001) at 1 year after operation. Conclusion: Results from short and medium term follow-up show that interventional therapy on top of heart failure drug therpay can effectively improve left cardiac function and attenuate cardiac remodeling in patients with TA-MAS comorbid with HFrEF.

The unbalanced behavioral activation and inhibition system sensitivity in internet gaming disorder: Evidence from resting-state Granger causal connectivity analysis

BACKGROUND

Patients with behavioral or substance addiction show an unbalanced behavioral activation system (BAS) and behavioral inhibition system (BIS) sensitivity. However, the relationship between internet gaming disorder (IGD) and BAS/BIS is obscure and the neurobiological mechanism underlying this relationship remains unclear.

METHODS

We recruited 154 IGDs and 229 recreational game users (RGUs) in the current study. First, we explored the relationship between BAS/BIS and IGD. Second, subjects were subdivided into subgroups by BAS/BIS sensitivity. Third, whole-brain Granger causal connectivity (GCC) of striatum and amygdala subdivisions was estimated for the subgroup. Fourth, mediation analysis was performed to explore the role of connectivity in the relationship between IGD and BAS/BIS sensitivity.

RESULTS

We found the IGD group scored higher than the RGU on BIS and BASf (fun-seeking) sensitivity. Then, we identified 4 (2*2) subgroups: low/high risk of IGD with low/high BAS/BIS sensitivity groups. Two-way ANCOVA main results of interaction effects showed that in the high BAS/BIS group, the RGU exhibited increased strength in the GCC from the left putamen to the right cuneus, and the IGD exhibited decreased strength in the GCC from the right medial frontal gyrus to the caudate, from the left superior frontal gyrus to the centromedial amygdala, and from the right superior parietal lobule to the left laterobasal amygdala. Moreover, the GCC from the centromedial amygdala to the middle frontal gyrus mediated the directional relationship between BIS and IAT (Young's internet addiction test) scores.

CONCLUSIONS

The IGD individuals exhibited higher BIS and BAS-fun seeking sensitivity. Moreover, IGD with unbalanced BAS/BIS sensitivity exhibited alternative connectivity patterns involving amygdala and striatum subdivisions. These findings suggest a neurobiological mechanism for an alternation between IGD and RGU with different BAS/BIS sensitivity.

[Risk factors analysis on high-risk behaviors of drowning among students in Shufu county, Kashgar area, Xinjiang Uygur Autonomous Region]

Objective: To understand the incidence and risk factors of high-risk drowning behaviors among primary and middle school students in Shufu county, Kashgar area, Xinjiang Uygur Autonomous Region, and provide a theoretical basis for the development of drowning prevention policies and intervention measures. Methods: Cluster random sampling method was adopted in Bulakesu and Uppal of Shufu county. A total of 28 primaries and 2 middle schools were selected, and questionnaires surveyed all the students in grades 1-8. Results: A total of 14 543 questionnaires were sent out. 23.9% of primary and secondary school students had experienced high-risk drowning behavior in the past 12 months. Higher swimming level, introversion, intense curiosity, poor relationship with classmates, poor relationship with family, and open water near the school and open water near home were the risk factors of high-risk drowning behaviors. Conclusions: More attention should be paid to the psychology and high-risk behaviors of primary and middle school students, and the education of drowning knowledge and skills should be strengthened. Meanwhile, schools and communities should pay attention to the management and intervention of open water.

Predicting the severity of internet gaming disorder with resting-state brain features: A multi-voxel pattern analysis

BACKGROUND

Internet gaming disorder (IGD) has become a worldwide mental health concern; however, the neural mechanism underlying this disorder remains unclear. Multivoxel pattern analysis (MVPA), a newly developed data-driven approach, can be used to investigate the neural features of IGD based on massive neural data.

METHODS

Resting-state fMRI data from four hundred and two participants with varying levels of IGD severity were recruited. Regional homogeneity (ReHo) and the amplitude of low-frequency fluctuation (ALFF) were calculated and subsequently decoded by applying MVPA. The highly weighted regions in both predictive models were selected as regions of interest for further graph theory and Granger causality analysis (GCA) to explore how they affect IGD severity.

RESULTS

The results revealed that the neural patterns of ReHo and ALFF can independently and significantly predict IGD severity. The highly weighted regions that contributed to both predictive models were the right precentral gyrus and left postcentral gyrus. Moreover, topological properties of the right precentral gyrus were significantly correlated with IGD severity; further GCA revealed effective connectivity from the right precentral gyrus to left precentral gyrus and dorsal anterior cingulate cortex, both of which were significantly associated with IGD severity.

CONCLUSIONS

The present study demonstrated that IGD has distinctive neural patterns, and this pattern could be found by machine learning. In addition, the neural features in the right precentral gyrus play a key role in predicting IGD severity. The current study revealed the neural features of IGD and provided a potential target for IGD interventions using brain modulation.

[Health-adjusted life expectancy in residents in Guangzhou, 2010-2019]

Objective: To analyze the spatiotemporal distribution of life expectancy (LE) and health-adjusted life expectancy (HALE) in Guangzhou from 2010 to 2019, and quantize the comprehensive impact of different causes and sequelae on health. Methods: The LE, HALE, and cause-excluded health adjusted life expectancy (CEHALE) were estimated using cause-of-death surveillance datasets from Guangzhou Municipal Center for Disease Control and Prevention from 2010 to 2019 and open data from the Global Burden of Disease Study. Joinpoint log-linear regression model was used to analyze the temporal trend and described spatial distribution. Results: In 2019, the LE in residents in Guangzhou was 82.9 years (80.1 years in men and 85.9 years in women), and the HALE was 75.6 years (74.0 years in men and 77.3 years in women). Compared with the urban fringe, the central urban area had higher LE and HALE, and the differences between LE and HALE were small. The LE and HALE in Guangzhou showed an increasing trend from 2010 to 2019. The LE increased by 2.8 years (AAPC=0.4, 95%CI: 0.3-0.4), with the increase of 2.8 years in men and 2.9 years in women. The HALE increased by 2.4 years (AAPC=0.3, 95%CI: 0.3-0.4), with the increase of 2.5 years in men and 2.2 years in women. The median healthy life lost due to communicable, maternal, neonatal, and nutritional diseases was 6.2 years (AAPC=-4.2, 95%CI: -5.3--3.1), while the median healthy life lost due to non-communicable diseases was 14.7 years (AAPC=1.6, 95%CI: 0.9-2.3), the median healthy life expectancy reduced by injury was 6.3 years (AAPC=-3.5, 95%CI: -4.5--2.6). Musculoskeletal disorders, skin and subcutaneous diseases, cardiovascular diseases, nutritional deficiencies, diabetes and kidney diseases were the top five diseases causing healthy life expectancy loss. Conclusion: The LE and HALE in residents in Guangzhou increased steadily from 2010 to 2019, but the quality of life in the urban fringe was lower than that of the central urban area. Non-communicable diseases were the leading causes of healthy life expectancy loss. Health policies and prevention measures should be developed according to area specific characteristics, and social medical resources should be rationally allocated to key diseases to reduce their disease burden.

[Phenotypes and genotypes of 78 patients with propionic acidemia]

Objective: Propionic acidemia is a rare inherited metabolic disorder caused by propionyl CoA carboxylase (PCC) deficiency. This study aims to analyze the clinical characteristics and gene variations of Chinese patients with propionic acidemia, and to explore the correlation between clinical phenotypes and genotypes. Methods: Single-center, retrospective and observational study. Seventy-eight patients of propionic acidemia (46 males and 32 females) from 20 provinces and autonomous regions were admitted from January 2007 to April 2022. Their age of initial diagnosis ranged from 7 days to 15 years. The clinical manifestations, biochemical and metabolic abnormalities, genetic variations, diagnosis, treatment and outcome were studied. Chi-Square test or Mann-Whitney U test were used for statistical analysis. Results: Among 78 cases, 6 (7.7%) were identified by newborn screening; 72 (92.3%) were clinically diagnosed after onset, and the age of onset was 2 hours after birth to 15 years old; 32 cases had early-onset disease and 40 cases had late-onset disease. The initial manifestations included lethargy, hypotonia, vomiting, feeding difficulties, developmental delay, epilepsy, and coma. Among the 74 cases who accepted gene analysis, 35 (47.3%) had PCCA variants and 39 (52.7%) had PCCB variants. A total of 39 PCCA variants and 32 PCCB variants were detected, among which c.2002G>A and c.229C>T in PCCA and c.838dupC and c.1087T>C in PCCB were the most common variants in this cohort. The variants c.1228C>T and c.1283C>T in PCCB may be related to early-onset type. The variants c.838dupC, c.1127G>T and c.1316A>G in PCCB, and c.2002G>A in PCCA may be related to late-onset disease. Six patients detected by newborn screening and treated at asymptomatic stage developed normal. The clinically diagnosed 72 cases had varied complications. 10 (12.8%) cases of them died. 62 patients improved after metabolic therapy by L-carnitine and diet. Six patients received liver transplantation because of recurrent metabolic crisis. Their clinical symptoms were markedly improved. Conclusion: The clinical manifestations of propionic acidemia are complex and lack of specificity. Newborn screening and high-risk screening are keys for early treatment and better outcome. The correlation between the genotype and phenotype of propionic acidemia is unclear, but certain variants may be associated with early-onset or late-onset propionic acidemia.

Uncovering lipopolysaccharide regulation in bacteria via the critical lipid binding tunnel of YciS/YciM

Gram-negative bacteria contain an asymmetric outer membrane, in which the outer leaflet is composed of lipopolysaccharide (LPS). LPS, a drug target of polymyxin, plays an essential role in drug resistance, biofilm formation, and pathogenesis. An important inner membrane protein, YciM, may be responsible for the regulation of LPS biosynthesis and transport. Here, we report the crystal structure of YciM from Salmonella typhimurium in a complex with a non-specifically bond molecule, an ethylene glycol, which identified a tunnel that could bind lipids. Our in vitro assays showed that YciM could bind lipid molecules with affinity in the micromolar range, while mutagenic and functional studies confirmed that lipid-binding residues are critical for the function of YciM. Additionally, our data also showed that YciM accurately regulates LPS biosynthesis and transport with YciS, which could help to better understand the regulation mechanism of LPS.

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Identifying a critical lipid binding tunnel of YciS/YciM

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The lipid binding tunnel could bind lipid molecules

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Mutants of lipid binding tunnel inhibit cell growth severely

An engineered 5-helix bundle derived from SARS-CoV-2 S2 pre-binds sarbecoviral spike at both serological- and endosomal-pH to inhibit virus entry

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and related sarbecoviruses enter host cells by receptor-recognition and membrane-fusion. An indispensable step in fusion is the formation of 6-helix bundle by viral spike heptad repeats 1 and 2 (HR1 and HR2). Here, we report the construction of 5-helix bundle (5HB) proteins for virus infection inhibition. The optimal construct inhibits SARS-CoV-2 pseudovirus entry with sub-micromolar IC50. Unlike HR2-based peptides that cannot bind spike in the pre-fusion conformation, 5HB features with the capability of binding to pre-fusion spike. Furthermore, 5HB binds viral HR2 at both serological- and endosomal-pH, highlighting its entry-inhibition capacity when SARS-CoV-2 enters via either cell membrane fusion or endosomal route. Finally, we show that 5HB could neutralize S-mediated entry of the predominant SARS-CoV-2 variants and a wide spectrum of sarbecoviruses. These data provide proof-of-concept evidence that 5HB might be developed for the prevention and treatment of SARS-CoV-2 and other emerging sarbecovirus infections.

[Two cases of herpes simplex keratitis after trans-epithelial photorefractive keratectomy]

We herein report 2 cases of herpes simplex keratitis after trans-epithelial photorefractive keratectomy. Patients' medical histories, symptoms, signs, clinical examination results, diagnosis and treatment were showed in detail. Following precision diagnosis and medical intervention, including topical and systemic antiviral treatmented for 1 to 2 weeks. The two patients were cured with full reepithelialization without corneal scar.

A Potent Neutralizing Nanobody Targeting the Spike Receptor-Binding Domain of SARS-CoV-2 and the Structural Basis of Its Intimate Binding

The continuous spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) around the world has raised unprecedented challenges to the human society. Antibodies and nanobodies possessing neutralization activity represent promising drug candidates. In this study, we report the identification and characterization of a potent SARS-CoV-2 neutralizing nanobody that targets the viral spike receptor-binding domain (S-RBD). The nanobody, termed as Nb-007, engages SARS-CoV-2 S-RBD with the two-digit picomolar binding affinity and shows outstanding virus entry-inhibition activity. The complex structure of Nb-007 bound to SARS-CoV-2 S-RBD reveals an epitope that is partially overlapping with the binding site for the human receptor of angiotensin-converting enzyme 2 (ACE2). The nanobody therefore exerts neutralization by competing with ACE2 for S-RBD binding, which is further ascertained by our in-vitro biochemical analyses. Finally, we also show that Nb-007 reserves promising, though compromised, neutralization activity against the currently-circulating Delta variant and that fusion of the nanobody with Fc dramatically increases its entry-inhibition capacity. Taken together, these data have paved the way of developing Nb-007 as a drug-reserve for potential treatment of SARS-CoV-2 related diseases.

Histones released by NETosis enhance the infectivity of SARS-CoV-2 by bridging the spike protein subunit 2 and sialic acid on host cells

Neutrophil extracellular traps (NETs) can capture and kill viruses, such as influenza viruses, human immunodeficiency virus (HIV), and respiratory syncytial virus (RSV), thus contributing to host defense. Contrary to our expectation, we show here that the histones released by NETosis enhance the infectivity of SARS-CoV-2, as found by using live SARS-CoV-2 and two pseudovirus systems as well as a mouse model. The histone H3 or H4 selectively binds to subunit 2 of the spike (S) protein, as shown by a biochemical binding assay, surface plasmon resonance and binding energy calculation as well as the construction of a mutant S protein by replacing four acidic amino acids. Sialic acid on the host cell surface is the key molecule to which histones bridge subunit 2 of the S protein. Moreover, histones enhance cell–cell fusion. Finally, treatment with an inhibitor of NETosis, histone H3 or H4, or sialic acid notably affected the levels of sgRNA copies and the number of apoptotic cells in a mouse model. These findings suggest that SARS-CoV-2 could hijack histones from neutrophil NETosis to promote its host cell attachment and entry process and may be important in exploring pathogenesis and possible strategies to develop new effective therapies for COVID-19.

Menopausal hormone therapy: what are the problems in the perception of Chinese physicians?

OBJECTIVE

This study aimed to investigate Chinese physicians' perception and attitudes toward menopausal hormone therapy (MHT).

METHODS

This nationwide online survey was conducted in China. Physicians registered in the WeChat groups of the Gynecological Endocrinology Committee of China's Maternal and Child Health Care Association received a message invitation to complete this anonymous online survey from April 2020 to July 2020. Physicians' knowledge of and attitudes toward MHT were surveyed.

RESULTS

In total, 4672 questionnaires were submitted; only completed questionnaires could be submitted. The message was sent to 6021 doctors, so the response rate was 77.6%. Overall, 77.9-92.9% of physicians knew the common indications and contraindications to MHT. Additionally, 90.6%, 85.4%, 80.7% and 37.5% of physicians thought that MHT would increase the risk of venous thrombosis, breast cancer, endometrial cancer and weight gain, respectively. In total, 58.1% of the physicians mistakenly believed that a sex hormone test was one of the necessary examinations to reassess MHT prescription during follow-up visits. We found that 68.5% of physicians would consider using MHT themselves or recommend MHT to their partners in the future, and 11.4% were currently using MHT.

CONCLUSIONS

Most Chinese physicians have basic knowledge of MHT. Their misunderstandings about MHT mainly centered on the risks of endometrial cancer, weight gain and the necessary examinations during follow-up visits. These misunderstandings need to be clarified in future professional training programs.

[Research advances on signaling pathways affecting sweat gland development and their involvement in the reconstitution of sweat adenoid cells in vitro]

The damage of sweat glands in patients with extensive deep burns results in the loss of thermoregulation, which seriously affects the quality of life of patients. At present, there are many researches on the repair of sweat gland function, but the mechanism of human sweat gland development has not been fully clarified. More and more studies have shown that the cascaded pathways of Wnt/β-catenin, ecto- dysplasin A/ectodysplasin A receptor/nuclear factor-κB, sonic hedgehog, and forkhead box transcription factor jointly affect the development of sweat glands, and it has been reported that the cascaded signaling pathways can be used to achieve the reconstruction of sweat adenoid cells in vitro. This article reviews the signaling pathways that affect the development of sweat glands and their involvement in the reconstruction of sweat adenoid cells in vitro.

[Epidemiological characteristics of three local epidemics of COVID-19 in Guangzhou]

Objective: To understand the epidemiological characteristics of three local COVID-19 epidemics in Guangzhou and provide reference for optimizing strategies and measures of COVID-19 prevention and control. Methods: The data of local COVID-19 cases in Guangzhou reported as of June 18, 2021 were collected from National Notifiable Disease Report System of China. The software Excel 2019 and SPSS 22.0 were applied for data cleaning and statistical analysis. Results: A total of 726 COVID-19 cases were reported in the three local epidemics in Guangzhou. In the epidemic associated with the outbreak of COVID-19 in Hubei province, 366 cases were reported. Most cases were female (51.6%, 189/366), aged 18-65 years (81.4%, 298/366), jobless/unemployed (32.2%, 118/366) and retired persons (20.2%,74/366). The initial symptoms of most cases were fever (71.6%, 250/349) and cough (60.7%, 212/349). In the epidemic associated with the imported COVID-19 cases from Africa, 207 cases were reported. Most cases were aged 18-40 years (72.9%, 151/207), male (69.6%, 144/207), and engaged in commercial services (62.3%,129/207). The initial symptoms of most cases were no obvious discomfort (55.6%, 15/27) and cough (37.0%, 10/27). In the epidemic associated with Delta variant of SARS-CoV-2, 153 cases were reported, in which women accounted for 58.8% (90/153), most cases were over 41 years old (64.7%,99/153), and retired persons accounted for the highest proportion (32.0%,49/153). The initial symptoms of most cases were cough (32.9%, 48/146) and no obvious discomfort (28.1%, 41/146). The household secondary attack rates of the three local epidemics were 11.2%, 5.7% and 11.5%, respectively. The median (P₂₅, P₇₅) of incubation periods were 6.5 (4.0,10.8) d, 4.0 (2.5, 6.0) d and 4.0 (3.0,5.0) d. The serial intervals median (P₂₅, P₇₅) were 4.0 (3.0, 8.0) d, 4.0 (2.5, 6.0) d and 3.0 (2.0,5.0) d. There were significant differences in gender, age, occupation, initial symptoms, household secondary attack rate and incubation period among the three local COVID-19 epidemics (all P<0.05). In the proportion of the case finding way, passive detection in patient treatment were mainly 44.3%(162/366) in the epidemic associated with the outbreak of COVID-19 in Hubei province,but active community case screening [58.5% (121/207) and 27.5% (24/153)] and close contact management in imported case were mostly [33.3% (69/207) and 67.3% (103/153)] in the epidemic associated with the imported COVID-19 cases from Africa and with Delta variant of SARS-CoV-2, respectively. Conclusions: Due to the different sources of infection, strain types and prevention and control strategies, the epidemiological characteristics of the three local COVID-19 epidemics in Guangzhou differed in demographics, clinical symptoms, transmission routes and case finding, which suggested that it is necessary to improve the key population and common symptom monitoring in the routine prevention and control of COVID-19 to prevent the reemerge of the epidemic.