Characterizing fitness and immune escape of SARS-CoV-2 EG.5 sublineage using elderly serum and nasal organoid

SARS-CoV-2 Omicron variant has evolved into sublineages. Here, we compared the neutralization susceptibility and viral fitness of EG.5.1 and XBB.1.9.1. Serum neutralization antibody titer against EG.5.1 was 1.71-fold lower than that for XBB.1.9.1. However, there was no significant difference in virus replication between EG.5.1 and XBB.1.9.1 in human nasal organoids and TMPRSS2/ACE2 over-expressing A549 cells. No significant difference was observed in competitive fitness and cytokine/chemokine response between EG.5.1 and XBB.1.9.1. Both EG.5.1 and XBB.1.9.1 replicated more robustly in the nasal organoid from a younger adult than that from an older adult. Our findings suggest that enhanced immune escape contributes to the dominance of EG.5.1 over earlier sublineages. The combination of population serum susceptibility testing and viral fitness evaluation with nasal organoids may hold promise in risk assessment of upcoming variants. Utilization of serum specimens and nasal organoid derived from older adults provides a targeted risk assessment for this vulnerable population.

[A case of nontuberculous mycobacterium presenting as a mass and atelectasis with mediastinal and hilar lymph node enlargement]

With the development of testing technology, the diagnosis of nontuberculous mycobacterium (NTM) lung disease has gradually increased in recent years. Because the clinical characteristics of NTM are not typical, and its imaging manifestations are diverse and nonspecific, missed diagnosis and misdiagnosis are common. Etiological investigation is necessary for diagnosis. Conventional etiological investigations are very limited for the diagnosis of NTM. We reported a case of NTM lung disease presenting with a mass and atelectasis with mediastinal and hilar lymph node enlargement that resembled malignant tumors. The literature on this condition was reviewed to improve the clinician's understanding and broaden clinical thinking.

[A multicenter prospective study on early identification of refractory Mycoplasma pneumoniae pneumonia in children]

Objective: To explore potential predictors of refractory Mycoplasma pneumoniae pneumonia (RMPP) in early stage. Methods: The prospective multicenter study was conducted in Zhejiang, China from May 1st, 2019 to January 31st, 2020. A total of 1 428 patients with fever >48 hours to <120 hours were studied. Their clinical data and oral pharyngeal swab samples were collected; Mycoplasma pneumoniae DNA in pharyngeal swab specimens was detected. Patients with positive Mycoplasma pneumoniae DNA results underwent a series of tests, including chest X-ray, complete blood count, C-reactive protein, lactate dehydrogenase (LDH), and procalcitonin. According to the occurrence of RMPP, the patients were divided into two groups, RMPP group and general Mycoplasma pneumoniae pneumonia (GMPP) group. Measurement data between the 2 groups were compared using Mann-Whitney U test. Logistic regression analyses were used to examine the associations between clinical data and RMPP. Receiver operating characteristic (ROC) curves were used to analyse the power of the markers for predicting RMPP. Results: A total of 1 428 patients finished the study, with 801 boys and 627 girls, aged 4.3 (2.7, 6.3) years. Mycoplasma pneumoniae DNA was positive in 534 cases (37.4%), of whom 446 cases (83.5%) were diagnosed with Mycoplasma pneumoniae pneumonia, including 251 boys and 195 girls, aged 5.2 (3.3, 6.9) years. Macrolides-resistant variation was positive in 410 cases (91.9%). Fifty-five cases were with RMPP, 391 cases with GMPP. The peak body temperature before the first visit and LDH levels in RMPP patients were higher than that in GMPP patients (39.6 (39.1, 40.0) vs. 39.2 (38.9, 39.7) ℃, 333 (279, 392) vs. 311 (259, 359) U/L, both P<0.05). Logistic regression showed the prediction probability π=exp (-29.7+0.667×Peak body temperature (℃)+0.004×LDH (U/L))/(1+exp (-29.7+0.667×Peak body temperature (℃)+0.004 × LDH (U/L))), the cut-off value to predict RMPP was 0.12, with a consensus of probability forecast of 0.89, sensitivity of 0.89, and specificity of 0.67; and the area under ROC curve was 0.682 (95%CI 0.593-0.771, P<0.01). Conclusion: In MPP patients with fever over 48 to <120 hours, a prediction probability π of RMPP can be calculated based on the peak body temperature and LDH level before the first visit, which can facilitate early identification of RMPP.

[A prospective study of association between physical activity and ischemic stroke in adults]

Objective: To explore the prospective associations between physical activity and incident ischemic stroke in adults. Methods: Data of China Kadoorie Biobank study in Tongxiang of Zhejiang were used. After excluding participants with cancers, strokes, heart diseases and diabetes at baseline study, a total of 53 916 participants aged 30-79 years were included in the final analysis. The participants were divided into 5 groups according to the quintiles of their physical activity level. Cox proportional hazard regression models was used to calculate the hazard ratios (HR) for the analysis on the association between baseline physical activity level and risk for ischemic stroke. Results: The total physical activity level in the participants was (30.63±15.25) metabolic equivalent (MET)-h/d, and it was higher in men [(31.04±15.48) MET-h/d] than that in women [(30.33±15.07) MET-h/d] (P<0.001). In 595 526 person-years of the follow-up (average 11.4 years), a total of 1 138 men and 1 082 women were newly diagnosed with ischemic stroke. Compared to participants with the lowest physical activity level (<16.17 MET-h/d), after adjusting for socio-demographic factors, lifestyle, BMI, waist circumference, and SBP, the HRs for the risk for ischemic stroke in those with moderate low physical activity level (16.17-24.94 MET-h/d), moderate physical activity level (24.95-35.63 MET-h/d), moderate high physical activity level (35.64-43.86 MET-h/d) and the highest physical activity level (≥43.87 MET-h/d) were 0.93 (95%CI: 0.83-1.04), 0.87 (95%CI: 0.76-0.98), 0.82 (95%CI: 0.71-0.95) and 0.76 (95%CI: 0.64-0.89), respectively. Conclusion: Improving physical activity level has an effect on reducing the risk for ischemic stroke.

Correlation study between bone metabolic markers, bone mineral density, and sarcopenia

OBJECTIVE

To investigate the correlation between bone metabolism markers, bone mineral density (BMD), and sarcopenia.

METHODS

A total of 331 consecutive patients aged ≥ 60 years who were hospitalized between November 2020 and December 2021 were enrolled. Participants were divided into sarcopenia and non-sarcopenia groups according to the Asian Working Group on Sarcopenia criteria (AWGS, 2019). The clinical data, bone metabolism markers (β-CTX, N-MID, and TP1NP), and BMD were compared between the two groups.

RESULTS

Age, β-CTX, and N-MID of the sarcopenia group were higher than those of the non-sarcopenia group (P < 0.05), but the BMD T values were lower than those of the non-sarcopenia group (P < 0.05). Binary logistic regression analysis showed that increased femoral neck BMD (FNBMD) was a protective factor for sarcopenia, while increased β-CTX was a risk factor. Pearson/Spearman correlation analysis showed that the diagnostic indices of sarcopenia were positively correlated with FNBMD and negatively correlated with β-CTX and N-MID. Multiple linear regression analysis revealed that BMI and FNBMD significantly positively affected muscle strength and appendicular skeletal muscle mass (ASM). The FNBMD significantly positively affected physical performance, while β-CTX significantly negatively affected muscle strength, ASM, and physical performance.

CONCLUSION

Increased FNBMD may be a protective factor against sarcopenia, and increased β-CTX may be a risk factor. The FNBMD significantly positively affected the diagnostic indices of sarcopenia, while β-CTX significantly negatively affected them. BMD and bone metabolism marker levels may be considered in early screening for sarcopenia.

[Technical specification for orthodontic transmission straight wire technique]

Malocclusion is an oral disease with a high prevalence. The goal of orthodontic treatment is health, aesthetics, function and stability. The transmission straight wire appliance and technique is an innovative orthodontic system with independent intellectual property rights invented by Professor Jiuxiang Lin's team based on decades of clinical experience, which provides a new solution for the non-surgical correction of skeletal malocclusions, especially class Ⅲ malocclusion, and it is also a good carrier for the implementation of the concept of healthy orthodontics. Due to the lack of guidelines, how to implement standardized application of transmission straight wire technique remains a problem to be solved. This technical specification was formed by combining the guidance from Professor Jiuxiang Lin and joint revision by a number of authoritative experts from the Orthodontic Special Committee, Chinese Stomatological Association, with reference to relevant literatures, and combined with abundant clinical experience of many experts. This specification aims to provide reference to standardize the clinical application of transmission straight wire technique, so as to reduce the risk and complications, and finally to improve the clinical application level of this technique.

[Differential expression and implication of m6A methylation in mice with experimental myocardial infarction]

Objective: To define differentially expressed N6-adenylate methylation (m6A) genes in the myocardial tissue of mice with myocardial infarction (MI) and explore its potential impact on the pathological process of MI. Methods: The random number table method was used to divide the eighteen SPF C57BL/6J male mice aged from 8 to 10 weeks into MI group (MI group, n=9) and control group (control group, n=9). Modified m6A genes from the myocardial tissue were detected via methylated RNA immunoprecipitation with the next generation sequencing (MeRIP-seq). We explored methylation modified characteristics, verified mRNA expression and m6A modified level by bioinformatics analysis, qPCR and MeRIP-qPCR. Results: The Heatmap revealed that 901 differentially modified m6A genes between MI and control group, of which 537 genes were upregulated, and 364 genes were downregulated. The principal component analysis affirmed that two groups could be distinguished significantly in terms of m6A gene modification. The characteristic sequence of m6A modification was GGACU and mainly concentrated in the coding sequence. According to the conjoint analysis with RNA-seq and MeRIP-seq, 119 genes expressed simultaneous m6A modification difference and mRNA expression difference. The Venn diagram exhibited the positive and negative correlation between m6A modification and mRNA expression. Besides, the GO enrichment analysis indicated that the genes with m6A differential modification in MI group were mainly involved in heart development and other processes. qPCR verified that Gbp6 was up-regulated, while Dnaja1 and Dnajb1 were down-regulated. MeRIP-qPCR revealed that the m6A modification level of Hspa1b was downregulated. Conclusion: Myocardial infarction induces differential modification of m6A in the mice model. In addition, the genes with m6A modification may be affected by methylation related enzymes, thus participating the pathogenesis of MI by regulating apoptosis and inflammation.

Determination of seroprevalence and kinetics of humoral response using mpox virus A29 protein

BACKGROUND

Mpox virus (MPXV), previously known as monkeypox virus, has spread globally in 2022. An accurate and convenient antibody test is essential for the determination of seroprevalence and for studying immune response after natural infection or vaccination. Most seroprevalence or vaccine studies used either live MPXV (or vaccinia virus [VACV]) or inactivated MPXV (or VACV) culture lysate for serological assays, but MPXV culture can only be performed in biosafety level 3 (BSL-3) facilities. Here, we developed and evaluated an enzyme immunoassay (EIA) based on the MPXV A29 surface envelope protein.

METHODS

We compared the specificity of the MPXV A29, VACV A27, and VACV lysate EIA using serum specimens collected prior to the global spread of MPXV. Next, we performed these EIAs for serum specimens collected from two mpox patients and an MVA-BN vaccine recipient. We also assessed the kinetics of plasmblast and MPXV A29-specific B-cell response.

RESULTS

Using sera collected from different age groups in Hong Kong, we found that most individuals, including those born before 1981 who have received the smallpox vaccine, tested negative using the MPXV A29 protein. MPXV A29-specific antibody could be detected in the serum of mpox patients and an MVA-BN recipient. In a mpox patient, the frequency of plasmablast and MPXV A29-specific B cell peaked on day 8 post-symptom onset and gradually decreased. Finally, we demonstrated that antibodies against the A29 protein can be used for immunofluorescence staining of MPXV-infected cells.

CONCLUSIONS

MPXV A29 protein is suitable for studying the immune response against MPXV infection.

Humoral and cellular immunity against different SARS-CoV-2 variants in patients with chronic kidney disease

Chronic kidney disease (CKD) patients are at higher risk of severe COVID-19. Humoral and cellular immunity from prior infection or vaccination are important for protection, but the neutralizing antibody (nAb) response against SARS-CoV-2 variants is impaired. We investigated the variant-specific nAb and T cell immunity among CKD patients. Adult CKD patients were recruited between August and October 2022. nAb against the SARS-CoV-2 (ancestral strains and four Omicron sublineages) and T cell response were measured using the live virus neutralization assay and interferon-gamma release assay (IGRA). The correlation between nAb/T-cell response and subsequent infection after recruitment were also determined. Among the 88 recruited patients, 95.5% had prior infection or had completed the primary vaccine series. However, only 77.3% had detectable nAb against at least one SARS-CoV-2 strains, 59.1% tested positive in IGRA, and 52.3% had detectable nAb and tested positive in the IGRA. The nAb geometic mean titers (GMTs) against XBB.1, BA.5 and BA.2.3.20 were significantly lower than those against BA.2 and ancestral strain. Prior SARS-CoV-2 infection was associated with elevated nAb and T cell response. More kidney transplant recipients (KTRs) showed absent nAb and T cell response (36.8% vs. 10.1%), despite a higher prevalence of vaccine booster in this population (94.7% vs. 50.7%). Lower levels of nAb titer and T cell response were significantly associated with subsequent infection. A considerable proportion of CKD patients, especially KTRs, showed absence of humoral and cellular protective immunity against SARS-CoV-2. Strategies to improve immunogenicity in this population are urgently needed.

[Determination of 14 volatile organic compounds in urine by headspace gas chromatography-mass spectrometry]

Objective: To establish a automatic headspace gas chromatography-mass spectrometry (HS/GC-MS) method for the determination of 14 volatile organic compounds in urine. Methods: In September 2022, 10 ml urine sample was taken into a 20 ml headspace bottle, balanced for 30 min at 65 ℃, and then detected by HS/GC-MS and quantified by external standard method. Results: The 14 volatile organic compounds showed good linearity at 0.2-8.0 μg/L and 0.1-4.0 μg/L, with correlation coefficients ranging from 0.9956-0.9999. The recoveries were 79.8%-113.1% with relative standard deviations 0.05%-0.27% when three different concentration levels were added. Detection limit was 0.03-0.05 μg/L. Conclusion: The method is simple and convenient, and the recovery and precision meet the requirements. It can be used for the determination of common volatile organic compounds in urine.

[Effects of the anterolateral thigh chimeric perforator flaps in repairing complex wounds of foot and ankle]

Objective: To investigate the effects of anterolateral thigh chimeric perforator flap in repairing complex wounds of foot and ankle. Methods: A retrospective observational study was conducted. From May 2018 to June 2022, 23 patients who met the inclusion criteria were admitted to the First Affiliated Hospital of Air Force Medical University to repair complex wounds of foot and ankle with anterolateral thigh chimeric perforator flaps, including 15 males and 8 females, aged from 20 to 66 years. The wounds were all accompanied by bone exposure and defects, and were complicated with varying degrees of infection. All patients underwent debridement and continuous vacuum sealing drainage treatment for 1 week in stage Ⅰ, with the skin and soft tissue defect area after debridement being 10 cm×5 cm to 22 cm×7 cm. In stage Ⅱ, the anterolateral thigh chimeric perforator flap was used to cover the defective wound, of which the muscle flap was used to fill the deep invalid cavity of the ankle joint or cover bone and internal fixation exposures, and the skin flap was used to cover the superficial wound, with the area of the skin flap ranging from 11 cm×6 cm to 23 cm×8 cm, and the area of the muscle flap ranging from 4.0 cm×2.5 cm to 8.0 cm×5.0 cm. The survival of the flap was observed after operation. During follow-up, the color, texture, appearance, and complications of the flap were observed, the function of ankle joint and its range of dorsiflexion motion and plantar flexion motion were measured, and the scar hyperplasia and muscular hernia in donor area were observed. Results: Ecchymosis and epidermal necrosis occurred at the tip of the flap in 1 patient on 5 days after operation and healed after dressing change for 1 week; the other flaps of patients survived successfully. After 6 to 40 months of follow-up, the color, texture, and shape of flaps were good, but 1 patient was not satisfied with the shape of the flap because of flap swelling; the ankle joint movement was basically normal, the dorsiflexion motion was 15-30°, and the plantar flexion motion was 20-45°; the scar hyperplasia in the donor area of the flap was not obvious, and no muscular hernia occurred. Conclusions: The anterolateral thigh chimeric perforator flap can effectively fill the deep invalid cavity of ankle joint and cover the superficial wound at the same time, with minimal damage to the donor site. So it is an ideal flap for repairing the complex wounds of foot and ankle.

[Analysis on the secondary attack rates of SARS-CoV-2 Omicron variant and the associated factors]

Objective: To evaluate the secondary attack rates of the SARS-CoV-2 Omicron variant and the associated factors. Methods: A total of 328 primary cases and 40 146 close contacts of the SARS-CoV-2 Omicron variant routinely detected in local areas of Jiangsu Province from February to April 2022 were selected in this study, and those with positive nucleic acid test results during 7 days of centralized isolation medical observation were defined as secondary cases. The demographic information and clinical characteristics were collected, and the secondary attack rate (SAR) and the associated factors were analyzed by using a multivariate logistic regression model. Results: A total of 1 285 secondary cases of close contacts were reported from 328 primary cases, with a SAR of 3.2% (95%CI: 3.0%-3.4%). Among the 328 primary cases, males accounted for 61.9% (203 cases), with the median age (Q1, Q3) of 38.5 (27, 51) years old. Among the 1 285 secondary cases, males accounted for 59.1% (759 cases), with the median age (Q1, Q3) of 34 (17, 52) years old. The multivariate logistic regression model showed that the higher SAR was observed in the primary male cases (OR=1.632, 95%CI: 1.418-1.877), younger than 20 years old (OR=1.766, 95%CI: 1.506-2.072),≥60 years old (OR=1.869, 95%CI: 1.476-2.365), infected with the BA.2 strain branch (OR=2.906, 95%CI: 2.388-3.537), the confirmed common cases (OR=2.572, 95%CI: 2.036-3.249), and confirmed mild cases (OR=1.717, 95%CI: 1.486-1.985). Meanwhile, the higher SAR was observed in the close contacts younger than 20 years old (OR=2.604, 95%CI: 2.250-3.015),≥60 years old (OR=1.287, 95%CI: 1.052-1.573) and exposure for co-residence (OR=27.854, 95%CI: 23.470-33.057). Conclusion: The sex and age of the primary case of the Omicron variant, the branch of the infected strain, case severity of the primary case, as well as the age and contact mode of close contacts are the associated factors of SAR.

Role and Modality of Combining Radiotherapy with Immunotherapy in Stage III-IV Unresectable Small Cell Lung Cancer

PURPOSE/OBJECTIVE(S)

The combination of radiotherapy and immunotherapy was rarely reported in the management of small cell lung cancer (SCLC). We retrospectively assessed the role and modality of this combination in Stage III-IV unresectable SCLC.

MATERIALS/METHODS

Patients with stage III and IV SCLC were enrolled according to AJCC 8th edition. Both efficacy and safety of immunotherapy combined with radiotherapy were evaluated. Thereinto, patients received first-line chemo-immunotherapy and sequential thoracic consolidation radiotherapy (TCRT) were further evaluated. Survival and descriptive analyses were performed.

RESULTS

Between January 1, 2019 and December 31, 2021, 51 patients were included in our analysis. Median follow-up was 28.0 months (95% CI 22.8-33.2). Patients received radiotherapy in treatment course had a prolonged 2-year overall survival (OS). And in the first-line immunotherapy cohort of 27 patients, the addition of TCRT significantly improved 2y-OS (72.22% vs. 13.89%, p = 0.0048), 2y-locoregional recurrence free survival (LRRFS) (90.00% vs 48.00%, p = 0.011), and 2y-distance progression free survival (DPFS) (66.67% vs. 16.67%, p = 0.039). Subgroup analyses showed that TCRT rendered superior outcomes regardless of brain metastases. Dose-escalation (45 Gy/15f) and earlier radiotherapy seemed to improve the benefit. Of 70.37% (19/27) patients experienced disease progression in the TCRT evaluation cohort, 63.16% (12/19) patients failed in brain. A tendency toward better OS and superior brain metastases free survival (BMFS) were observed after receiving prophylactic cranial irradiation (PCI). Finally, the most common grade 2 or higher toxic effects were pneumonitis in all patients (11.76% of immune-related vs. 7.84% of radiation related).

CONCLUSION

Earlier addition of TCRT to immunotherapy could significantly improve survival and extracranial control for stage IIIA-IVB unresectable SCLC patients, with no increased risk of adverse events. In the era of immunotherapy, PCI may still be a recommended strategy. Further investigation is warranted.

[Relationship between orthodontic treatment and root resorption]

As one of the common complications of orthodontic treatment, external apical root resorption (EARR) often occurs during orthodontic treatment. This paper systematically elaborates the degree classification of EARR and the biological mechanism of root resorption in orthodontic treatment. At the same time, orthodontic root resorption is caused by a variety of factors. They are not only affected by genetic and environmental factors, but also by great individual differences. This paper summarizes the factors influencing the root resorption of orthodontic teeth and the prognosis of root resorption. This paper also provides some suggestions for the prevention and treatment of root resorption in the process of orthodontics, in order to provide guidance and help for the clinical work of orthodontists.

The viral fitness and intrinsic pathogenicity of dominant SARS-CoV-2 Omicron sublineages BA.1, BA.2, and BA.5

BACKGROUND

Among the Omicron sublineages that have emerged, BA.1, BA.2, BA.5, and their related sublineages have resulted in the largest number of infections. While recent studies demonstrated that all Omicron sublineages robustly escape neutralizing antibody response, it remains unclear on whether these Omicron sublineages share any pattern of evolutionary trajectory on their replication efficiency and intrinsic pathogenicity along the respiratory tract.

METHODS

We compared the virological features, replication capacity of dominant Omicron sublineages BA.1, BA.2 and BA.5 in the human nasal epithelium, and characterized their pathogenicity in K18-hACE2, A129, young C57BL/6, and aged C57BL/6 mice.

FINDINGS

We found that BA.5 replicated most robustly, followed by BA.2 and BA.1, in the differentiated human nasal epithelium. Consistently, BA.5 infection resulted in higher viral gene copies, infectious viral titres and more abundant viral antigen expression in the nasal turbinates of the infected K18-hACE2 transgenic mice. In contrast, the Omicron sublineages are continuously attenuated in lungs of infected K18-hACE2 and C57BL/6 mice, leading to decreased pathogenicity. Nevertheless, lung manifestations remain severe in Omicron sublineages-infected A129 and aged C57BL/6 mice.

INTERPRETATION

Our results suggested that the Omicron sublineages might be gaining intrinsic replication fitness in the upper respiratory tract, therefore highlighting the importance of global surveillance of the emergence of hyper-transmissive Omicron sublineages. On the contrary, replication and intrinsic pathogenicity of Omicron is suggested to be further attenuated in the lower respiratory tract. Effective vaccination and other precautions should be in place to prevent severe infections in the immunocompromised populations at risk.

FUNDING

A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.

Broad-spectrum humanized monoclonal neutralizing antibody against SARS-CoV-2 variants, including the Omicron variant

Introduction

Therapeutic monoclonal antibodies (mAbs) against the SARS-CoV-2 spike protein have been shown to improve the outcome of severe COVID-19 patients in clinical trials. However, novel variants with spike protein mutations can render many currently available mAbs ineffective.

Methods

We produced mAbs by using hybridoma cells that generated from mice immunized with spike protein trimer and receptor binding domain (RBD). The panel of mAbs were screened for binding and neutralizing activity against different SARS-CoV-2 variants. The in vivo effectiveness of WKS13 was evaluated in a hamster model.

Results

Out of 960 clones, we identified 18 mAbs that could bind spike protein. Ten of the mAbs could attach to RBD, among which five had neutralizing activity against the ancestral strain and could block the binding between the spike protein and human ACE2. One of these mAbs, WKS13, had broad neutralizing activity against all Variants of Concern (VOCs), including the Omicron variant. Both murine or humanized versions of WKS13 could reduce the lung viral load in hamsters infected with the Delta variant.

Conclusions

Our data showed that broad-spectrum high potency mAbs can be produced from immunized mice, which can be used in humans after humanization of the Fc region. Our method represents a versatile and rapid strategy for generating therapeutic mAbs for upcoming novel variants.

Rational design of a booster vaccine against COVID-19 based on antigenic distance

Current COVID-19 vaccines are highly effective against symptomatic disease, but repeated booster doses using vaccines based on the ancestral strain offer limited additional protection against SARS-CoV-2 variants of concern (VOCs). To address this, we used antigenic distance to in silico select optimized booster vaccine seed strains effective against both current and future VOCs. Our model suggests that a SARS-CoV-1-based booster vaccine has the potential to cover a broader range of VOCs. Candidate vaccines including the spike protein from ancestral SARS-CoV-2, Delta, Omicron (BA.1), SARS-CoV-1, or MERS-CoV were experimentally evaluated in mice following two doses of the BNT162b2 vaccine. The SARS-CoV-1-based booster vaccine outperformed other candidates in terms of neutralizing antibody breadth and duration, as well as protective activity against Omicron (BA.2) challenge. This study suggests a unique strategy for selecting booster vaccines based on antigenic distance, which may be useful in designing future booster vaccines as new SARS-CoV-2 variants emerge.

[Research progress of biomaterials in promoting wound vascularization]

Promoting rapid and good vascularization is still a great challenge for the research and development of biomaterials for wound repair. Current studies have shown that wound vascularization is closely related to the pores, components, and channels of biomaterials. Although the research and development of new medical functional materials have made rapid progress in recent years, and gratifying achievements have been made in the reconstruction of skin barrier function, regulation of wound microenvironment, and antibacterial and anti-inflammatory effects, etc., the problem of rapid wound vascularization has not been solved. This paper introduces the process of wound vascularization, the strategy of biomaterials promoting wound vascularization, the construction of biomaterials promoting wound vascularization based on three-dimensional printing technology, and the influence of nanotechnology on wound vascularization, in order to provide new enlightenment for research and development of wound repair materials with rapid vascularization in the future.

Andrographolide Liquisolid using Porous-Starch as the Adsorbent with Enhanced Oral Bioavailability in Rats

Andrographolide (AGL) is the major component of Andrographispaniculata. The poor water solubility and low dissolution strongly affect its oral absorption. Liquisolid technology has been used to improve its dissolution and oral bioavailability. Liquisolid powders of AGL (AGL-LS-PSG) were obtained by firstly dissolving AGL in the mixture of NMP, PEG 6000 and Soluplus®, and solidified by absorption of the blend in porous starch. Angle of repose, Carr index and Hauser ratio presented good powder fluidity and compressibility characteristics of AGL-LS-PSG. The results of optical microscopic observation, PXRD and DSC analysis indicated that AGL has been completely adsorbed in porous starch granules and existed in an amorphous or molecularly dispersing state. AGL-LS-PSG can obviously increase the drug dissolution rate compared to commercial guttate pills and raw drug. In vivo pharmacokinetic behavior of AGL-LS-PSG was investigated following a single oral administration to rats. The C_max (0.37 ± 0.06 μg mL^-1) and AUC_0-2h (13.55 ± 2.67 μg h mL^-1) of AGL-LS-PSG were evidently increased compared to commercial guttate pills (C_max = 0.30 ± 0.21 μg mL^-1, AUC_0-2h = 9.88 ± 3.57 μg h mL^-1). This study indicated great potential of liquisolid technology in effectively improving the dissolution and bioavailability of AGL.

Effect of vaccine booster, vaccine type, and hybrid immunity on humoral and cellular immunity against SARS-CoV-2 ancestral strain and Omicron variant sublineages BA.2 and BA.5 among older adults with comorbidities: a cross sectional study

BACKGROUND

Vaccination reduces COVID-19-related hospitalization among older adults. However, how SARS-CoV-2 infection and vaccine regimens affect vaccine-elicited immunity remain unclear.

METHODS

This is a cross-sectional study recruiting adults aged ≥70 years with comorbidities in Hong Kong. Demographic and clinical information were collected using a questionnaire. Neutralizing antibody (nAb) titers (against ancestral and Omicron strains) and SARS-CoV-2-specific T cell response were analyzed according to infection and vaccination status. Multivariable regression analysis was performed to assess the associations of BNT162b2 and booster doses with higher nAb titers, with adjustment for comorbidities.

FINDINGS

In July 2022, 101 patients were recruited, of whom 25 (24%) had previous infection. Overall, the geometric mean titer (GMT) of BA.5 nAb was 2.8-fold lower than that against BA.2 (P < 0.0001). The ancestral strain and BA.2 titers were higher for the 3-4-dose-BNT162 group than the 2-dose-BNT162b2 group. Non-infected individuals in the 3-4-dose-CoronaVac group had a more robust T cell response than the 2-dose-CoronaVac group (P = 0.0181), but there was no significant difference between the 2-dose-BNT162b2 and 3-4-dose-BNT162b groups. Patients who had heterologous CoronaVac-BNT162b2 prime-boost regimen had 3.22-fold higher BA.5 nAb titers than those who were primed/boosted with CoronaVac (P = 0.0207). Patients with hybrid immunity had higher Omicron nAb titers than those with vaccine-only immunity. Multivariable analysis showed that BNT162b2 and booster doses were independently associated with higher ancestral strain nAb titers.

INTERPRETATION

Our data support the use of booster doses for older adults with or without prior infection. Non-infected individuals primed with CoronaVac will benefit from heterologous mRNA vaccine booster.

FUNDING

Richard and Carol Yu, May Tam Mak Mei Yin, The Shaw Foundation Hong Kong, Michael Tong, Marina Lee, Government Consultancy Service (See acknowledgements for full list).

[Follow-up study on the relationship between changes in waist circumference and body weight and changes in blood pressure levels among high cardiovascular risk population]

Objective: To investigate the relationship between changes in waist circumference, body weight, and blood pressure change in a high cardiovascular risk population and to provide a theoretical basis and reference for the prevention and treatment of hypertension and cardiovascular disease. Methods: A total of 12 931 patients with a high risk of cardiovascular disease participating in the follow-up survey in 2016 were selected as the study subjects, and their long-term follow-up data from 2017 to 2019 were included in the analysis. Statistical analysis was performed using a t-test, χ² test, and generalized estimation equation (GEE). Results: Increased waist circumference, body weight, and BMI were associated with a higher risk of elevated blood pressure in people at high risk of cardiovascular disease. Waist circumference, weight, and BMI were reduced when blood pressure levels were lower. SBP and DBP increased by 0.200 (95%CI: 0.164-0.236) mmHg and 0.085 (95%CI: 0.066-0.105) mmHg for each 1 cm increase of waist circumference. SBP increased by 0.355 (95%CI: 0.289-0.421) mmHg and DBP increased by 0.182 (95%CI: 0.144-0.220) mmHg for each 1 kg increase in body weight. For each 1 kg/m² increase in BMI, SBP increased by 1.100 (95%CI: 1.194-1.258) mmHg, and DBP increased by 0.365 (95%CI: 0.273-0.456) mmHg. Compared with urban residents, SBP changes more with waist circumference and body weight, and DBP changes more with waist circumference in high-risk cardiovascular disease groups (all P for interaction <0.05). SBP with waist circumference and BMI and DBP with BMI was greater in participants without hypertension than in those with hypertension (all P for interaction <0.05). Conclusion: There is a positive linear correlation between the changes in waist circumference, body weight, and BMI and the changes in blood pressure in a high-risk cardiovascular disease population.

SARS-CoV-2 Omicron variant shows less efficient replication and fusion activity when compared with Delta variant in TMPRSS2-expressed cells

The novel SARS-CoV-2 Omicron variant (B.1.1.529), first found in early November 2021, has sparked considerable global concern and it has >50 mutations, many of which are known to affect transmissibility or cause immune escape. In this study, we sought to investigate the virological characteristics of the Omicron variant and compared it with the Delta variant which has dominated the world since mid-2021. Omicron variant replicated more slowly than the Delta variant in transmembrane serine protease 2 (TMPRSS2)-overexpressing VeroE6 (VeroE6/TMPRSS2) cells. Notably, the Delta variant replicated well in Calu3 cell line which has robust TMPRSS2 expression, while the Omicron variant replicated poorly in this cell line. Competition assay showed that Delta variant outcompeted Omicron variant in VeroE6/TMPRSS2 and Calu3 cells. To confirm the difference in entry pathway between the Omicron and Delta variants, we assessed the antiviral effect of bafilomycin A1, chloroquine (inhibiting endocytic pathway), and camostat (inhibiting TMPRSS2 pathway). Camostat potently inhibited the Delta variant but not the Omicron variant, while bafilomycin A1 and chloroquine could inhibit both Omicron and Delta variants. Moreover, the Omicron variant also showed weaker cell-cell fusion activity when compared with Delta variant in VeroE6/TMPRSS2 cells. Collectively, our results suggest that Omicron variant infection is not enhanced by TMPRSS2 but is largely mediated via the endocytic pathway. The difference in entry pathway between Omicron and Delta variants may have an implication on the clinical manifestations or disease severity.

[MRI features of lymphoepithelioma-like intrahepatic cholangiocarcinoma]

Objective: To investigate the MRI manifestations of lymphoepithelioma-like intrahep cholangiocarcinoma (LEL-ICC). Methods: MR images of 26 cases with LEL-ICC confirmed pathologically at Zhongshan Hospital Affiliated with Fudan University between March 2011 and March 2021 were retrospectively analyzed. The number, location, size, morphology, edges of lesions, non-scan signal intensity, cystic necrosis, enhancement mode, peak, and capsule, vascular invasion, lymph node metastasis, and other MR images were included for analysis. The apparent diffusion coefficient (ADC) value of the lesion and the surrounding normal liver parenchyma were measured. A paired-sample t-test was used to statistically analyze the measurement data. Results: All 26 cases of LEL-ICC had solitary lesions. Mass-type LEL-ICC was the most common [n=23, lesion size (4.02±2.32) cm] with distribution along the bile duct [n=3, lesion size (7.23±1.40 cm)]. Among the 23 lesions of mass type LEL-ICC, most of the lesions were close to the liver capsule (n=20), round (n=22), clearly bordered (n=13), and cystic necrosis (n=22). In the three lesions of LEL-ICC distributed along the bile duct, most of them were close to the liver capsule (n=2), irregular (n=3), blurred edges (n=3), and cystic necrosis (n=3). All 26 lesions showed a low/slightly low signal on T₁WI, a high/slightly high signal on T₂WI, and a slightly high or high signal on DWI. Three lesions showed fast-in and fast-out enhancement modes, and 23 lesions showed continuous enhancement. Twenty-five lesions showed peak enhancement in the arterial phase, and one lesion appeared in the delayed phase. The ADC value of 26 lesions and adjacent normal liver parenchyma was (1.112±0.274)×10^-3 mm²/s and (1.482±0.346)×10^-3 mm²/s, respectively, and the both had a statistically significant difference (P<0.05). Conclusion: Certain manifestations of LEL-ICC in magnetic resonance imaging are advantageous for diagnosis and differential diagnosis.

[Mendelian randomization and its application in periodontitis]

Mendelian randomization is a causal inference method using genetic variations as instrumental variables, which skillfully takes advantages of the distributive randomness and timing priority of genetic variation, effectively avoiding confounding biases and reverse causalities in traditional observational researches. It has become a research hotspot in recent years. As a complex inflammatory disease, periodontitis is associated with many factors, but the cognitions about these associations are mostly based on traditional observational studies, lacking strong evidences to infer the causality. In order to bring up new research ideas in the periodontal field, this article mainly reviewed Mendelian randomization and its research progress in periodontitis.

[Association between self-reported gingival bleeding and prevalent hypertension among adults in a cross-sectional study in Zhejiang province]

Objective: To explore the association between self-reported gingival bleeding and prevalent hypertension among adults in Zhejiang with a cross-sectional study. Methods: After excluding participants with self-reported, physician-diagnosed heart diseases, stroke, diabetes, cancer, and those who never or rarely brush their teeth at baseline study, 48 625 participants aged 30-79 in the China Kadoorie Biobank (CKB) study from Tongxiang, Zhejiang were included for the final analysis. Three multivariable logistic regression models were used to estimate the odds ratios (ORs) for the associations of self-reported gingival bleeding with prevalent hypertension. Results: The mean age of women was (51.2±9.2) years, and 42.9% of participants had prevalent hypertension. The percentage of self-reported frequent gingival bleeding was 6.56% (95%CI: 6.38%-6.75%), significantly higher among women (8.08%, 95%CI: 7.82%-8.35%) than among men (4.36%, 95%CI: 4.12%-4.60%) (P<0.001). After adjusting for socio-demographic factors, behavioral lifestyle, sleep duration, BMI, waist circumference, snoring, in comparison with men whose gingivae never or rarely bleed while brushing teeth, the odds ratio (95%CI) of hypertension for those with occasional, and frequent gingival bleeding were 1.04 (0.96-1.12) and 1.18 (1.02-1.37), respectively (trend P =0.038). The corresponding figures for women were 0.96 (0.91-1.02) and 0.95 (0.86-1.05), respectively (trend P=0.344). Conclusion: Frequent gingival bleeding was positively associated with prevalent hypertension among men.

SARS-CoV-2 IgG seropositivity after the severe Omicron wave of COVID-19 in Hong Kong

The Omicron variant has led to a major fifth wave of COVID-19 in Hong Kong between January and May 2022. Here, we used seroprevalence to estimate the combined incidence of vaccination and SARS-CoV-2 infection, including subclinical infection which were not diagnosed at the acute stage. The overall seropositive rate of IgG against receptor binding domain (anti-RBD IgG) increased from 52.2% in December 2021 to 89.3% in May 2022. The level of anti-RBD IgG was lowest in the 0-9 and ≥80 year-old age groups in May 2022. The seropositive rate of antibody against ORF8, which reflects the rate of prior infection, was 23.4% in May 2022. Our data suggest that although most individuals were either vaccinated or infected after the fifth wave, children and older adults remain most vulnerable. Public health measures should target these vulnerable age groups in order to ameliorate the healthcare consequences of upcoming waves.

Contribution of low population immunity to the severe Omicron BA.2 outbreak in Hong Kong

Monitoring population protective immunity against SARS-CoV-2 variants is critical for risk assessment. We hypothesize that Hong Kong's explosive Omicron BA.2 outbreak in early 2022 could be explained by low herd immunity. Our seroprevalence study using sera collected from January to December 2021 shows a very low prevalence of neutralizing antibodies (NAb) against ancestral virus among older adults. The age group-specific prevalence of NAb generally correlates with the vaccination uptake rate, but older adults have a much lower NAb seropositive rate than vaccination uptake rate. For all age groups, the seroprevalence of NAb against Omicron variant is much lower than that against the ancestral virus. Our study suggests that this BA.2 outbreak and the exceptionally high case-fatality rate in the ≥80 year-old age group (9.2%) could be attributed to the lack of protective immunity in the population, especially among the vulnerable older adults, and that ongoing sero-surveillance is essential.

[Advances in circadian rhythms in oral maxillofacial tissues and oral-related diseases]

Circadian rhythm is an internal autonomous timing mechanism formed by the body in response to changes of external environment. It participates in the regulations of various physiological activities, affecting the formation and outcome of various diseases in the human body. This paper summarizes the changes of local tissue rhythms in common disease states, such as oral and maxillofacial malformations, inflammation and malignant tumors. The importance of circadian clock system to the activities of oral and maxillofacial tissues are dialectically analyzed, mainly on the mechanisms of action in maintaining oral health and in affecting the processes of common oral diseases and oral-related systemic diseases. At the same time, chronological therapy and new strategies of prevention and treatment for oral-related diseases based on the changes in tissue rhythm are summarized and prospected to provide new ideas for maintaining oral and systemic health.

[Consensus of experts on the oral health management and medical risk prevention for the patients with chronic airway diseases (2022 edition)]

Today, there is greater awareness on the association between oral diseases and respiration diseases after the outbreak of COVID-19. However, confusion regarding the oral health management and medical risk prevention for patients with chronic airway diseases has been remained among dental clinicians. Therefore, the dental experts of the Fifth General Dentistry Special Committee, Chinese Stomatological Association, combined with the experts of respiratory and critical care medicine, undertook the formation of consensus on the oral health management of patients with chronic airway diseases in order to help dental clinicians to evaluate medical risks and make better treatment decision in clinical practice. In the present consensus report, the relationship of oral diseases and chronic airway diseases, the oral health management and the treatment recommendations of patients with chronic airway diseases are provided.

[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.

Boosting of serum neutralizing activity against the Omicron variant among recovered COVID-19 patients by BNT162b2 and CoronaVac vaccines

Background

SARS-CoV-2 Omicron variant evades immunity from past infection or vaccination and is associated with a greater risk of reinfection among recovered COVID-19 patients. We assessed the serum neutralizing antibody (NAb) activity against Omicron variant (Omicron NAb) among recovered COVID-19 patients with or without vaccination.

Methods

In this prospective cohort study with 135 recovered COVID-19 patients, we determined the serum NAb titers against ancestral virus or variants using a live virus NAb assay. We used the receiver operating characteristic analysis to determine the optimal cutoff for a commercially-available surrogate NAb assay.

Findings

Among recovered COVID-19 patients, the serum live virus geometric mean Omicron NAb titer was statistically significantly higher among BNT162b2 recipients compared to non-vaccinated individuals (85.4 vs 5.6,P < 0.0001). The Omicron seropositive rates in live virus NAb test (NAb titer ≥10) were statistically significantly higher among BNT162b2 (90.6% [29/32];P < 0.0001) or CoronaVac (36.7% [11/30]; P = 0.0115) recipients when compared with non-vaccinated individuals (12.3% [9/73]). Subgroup analysis of CoronaVac recipients showed that the Omicron seropositive rates were higher among individuals with two doses than those with one dose (85.7% vs 21.7%; P = 0.0045). For the surrogate NAb assay, a cutoff of 109.1 AU/ml, which is 7.3-fold higher than the manufacturer's recommended cutoff, could achieve a sensitivity and specificity of 89.5% and 89.8%, respectively, in detecting Omicron NAb.

Interpretation

Among individuals with prior COVID-19, one dose of BNT162b2 or two doses of CoronaVac could induce detectable serum Omicron NAb. Our result would be particularly important for guiding vaccine policies in countries with COVID-19 vaccine shortage.

Funding

Health and Medical Research Fund, Richard and Carol Yu, Michael Tong (see acknowledgments for full list).

[Magnetic resonance imaging analysis on the effect of marathon on the dynamic changes of morphological characteristics of patellar tendon in amateur marathon runners after half marathon]

Objective: To explore the dynamic changes of morphological characteristics of patellar tendon (PT) in amateur athletes after a half-marathon using magnetic resonance imaging. Methods: A total of 19 male amateur marathon runners with 38 knee joints,aged from 26 to 53(41.5±7.9) years, running for 3 to 18 years, with a weekly running volume of 30-90 km and a monthly running volume of 100-300 km were enrolled and underwent 1.5T MRI scan before the half-marathon, within 3 hours after running and 3 days after running. Ten healthy male volunteers with 20 knee joints, who had never participated in marathon and exercised (including but not limited to running) per week for less than 150 minutes were recruited as the control group, aged from 26 to 54 (39.4±9.1) years. Firstly, the PT signal was qualitatively assessed on fat-suppressed proton density-weighted imaging (fs-PDWI) sequence to observe the presence of patellar tendinitis. Then, the length, proximal, middle and distal cross-sectional area (CSA), and volume of PT were measured using the post-processing tool ITK-SNAP, and the data were standardized. The independent sample t-test was used for comparing. One-way repeated measures analysis of variance was used to analyze the morphological changes of PT before and after half-marathon running. Results: The incidence of asymptomatic patellar tendinitis in amateur marathon runners was 26.3% (5/19). No significant MR signal changes of PT were observed in all runners after running. The proximal CSA in runners group was larger than that in controls [(4.20±0.62) mm²/kg^3/4 vs (3.63±0.57) mm²/kg^3/4, P<0.05], and there was no significant difference in length, medium and distal CSA and volume(all P>0.05). The length, proximal and distal CSA and volume of PT in runners group increased at 3 h after running [(47.35±3.22) mm vs (46.83±3.35) mm; (102.52±13.03) mm² vs (98.98±13.14) mm²; (108.67±15.72) mm² vs (100.27±14.37) mm²; (4 020.36±514.38) mm³ vs (3 826.57±499.23) mm³, all P<0.05]. There was no significant difference between before running and 3 days after running(all P>0.05). The middle CSA were not significantly different among different periods(all P>0.05). Conclusion: Marathon has effect on the normal PT morphology in male amateur marathon runners, showing an increase in proximal CSA. A half-marathon will cause reversible changes in PT length, regional CSA and volume.

[Diffusion tensor imaging in quantitative evaluation on thigh muscle of male amateur marathon runners after running a half marathon]

Objective: To investigate the effect of half marathon on thigh muscle in male amateur marathon runners by diffusion tensor imaging (DTI). Methods: A total of 17 male amateur marathon runners aged from 27 to 57 (43.7±2.8) years were recruited from May to August 2020 in Hangzhou, Zhejiang Province. MRI examination of bilateral thigh muscles were performed before and 3 h, 3 d and 7 d after a half marathon. The fractional anisotropy (FA) values was obtained by DTI sequence. The FA values of rectus femoris, intermedius femoris, medial femoris, lateral femoris, biceps femoris longus, semitendinosus, semimembranosus, adductor magnus and adductor longus were measured on the horizontal axis of bilateral thigh muscles. Friedman M test was used to compare the changes of FA values of each muscle at each time point before and after running, and pairwise comparison of FA values of statistically significant muscles at 3 h, 3 d and 7 d after running was performed. Results: The overall FA value of thigh muscle group [M (Q₁, Q₃)] at 3 h after running was decreased compared to before running [0.24 (0.20, 0.28) to 0.25 (0.21, 0.29), P<0.001], and there was no significant difference between baseline values at 3 d and 7 d after running (all P>0.05). FA values of vastus intermedius, vastus medialis, semimembranosus and adductor magnus at 3 h after running were lower than those before running [(0.19 (0.18, 0.22) vs 0.21 (0.19, 0.24), 0.19 (0.17, 0.20) vs 0.21 (0.18, 0.23), 0.26 (0.24), 0.29) vs 0.27 (0.15, 0.30) and 0.20 (0.19, 0.22) vs 0.21 (0.20, 0.23), both P<0.05], and there was no statistical significance between 3 d and 7 d after running and those before running (all P>0.05). FA value of vastus lateralis muscle at 3 h after running decreased compared with that before running, but the difference was not statistically significant (P>0.05). FA value began to increase at 7 d after running, and the difference was statistically significant [0.24 (0.21, 0.27) vs 0.23 (0.19, 0.25), P = 0.002]. FA value of rectus femoris muscle at 3 h after running decreased compared with that before running, but the difference was not statistically significant (P>0.05), and began to increase at 3 d after running and the difference was statistically significant [0.29 (0.26, 0.34) vs 0.26 (0.23, 0.29), P=0.006]. FA value of adductor longus muscle increased at 3 h after running, but the difference was not statistically significant (P>0.05). FA value continued to increase at 3 d and 7 d after running, and the difference was statistically significant [0.23 (0.21, 0.25) vs 0.22 (0.19, 0.24), 0.23 (0.21, 0.26) vs 0.22 (0.19, 0.24), all P<0.05]. Conclusions: The change of FA value of thigh muscle after half marathon is reversible. At 3 h after half marathon, FA values of femoris intermedius, femoris medialis, semimembranosus muscle and adductor magnus muscle of amateur marathon runners decreased most obviously, which may be the dominant muscle group during running.

Probable Animal-to-Human Transmission of SARS-CoV-2 Delta Variant AY.127 Causing a Pet Shop-Related COVID-19 Outbreak in Hong Kong

Background

SARS-CoV-2 can infect human and other mammals, including hamsters. Syrian (Mesocricetus auratus) and dwarf (Phodopus sp.) hamsters are susceptible to SARS-CoV-2 infection in the laboratory setting. However, pet shop-related COVID-19 outbreaks have not been reported.

Methods

We conducted an investigation of a pet shop-related COVID-19 outbreak due to Delta variant AY.127 involving at least three patients in Hong Kong. We tested samples collected from the patients, environment, and hamsters linked to this outbreak and performed whole genome sequencing analysis of the RT-PCR-positive samples.

Results

The patients included a pet shop keeper (Patient 1), a female customer of the pet shop (Patient 2), and the husband of Patient 2 (Patient 3). Investigation showed that 17.2% (5/29) and 25.5% (13/51) environmental specimens collected from the pet shop and its related warehouse, respectively, tested positive for SARS-CoV-2 RNA by RT-PCR. Among euthanized hamsters randomly collected from the storehouse, 3% (3/100) tested positive for SARS-CoV-2 RNA by RT-PCR and seropositive for anti-SARS-CoV-2 antibody by ELISA. Whole genome analysis showed that although all genomes from the outbreak belonged to the Delta variant AY.127, there were at least 3 nucleotide differences among the genomes from different patients and the hamster cages. Genomic analysis suggests that multiple strains have emerged within the hamster population, and these different strains have likely transmitted to human either via direct contact or via the environment.

Conclusions

Our study demonstrated probable hamster-to-human transmission of SARS-CoV-2. As pet trading is common around the world, this can represent a route of international spread of this pandemic virus.

Interferon-gamma inhibits influenza A virus cellular attachment by reducing sialic acid cluster size

The mucosal antiviral role of type I and III interferon in influenza virus infection is well established. However, much less is known about the antiviral mechanism of type II interferon (interferon-gamma). Here, we revealed an antiviral mechanism of interferon-gamma by inhibiting influenza A virus (IAV) attachment. By direct stochastic optical reconstruction microscopy, confocal microscopy, and flow cytometry, we have shown that interferon-gamma reduced the size of α-2,3 and α-2,6-linked sialic acid clusters, without changing the sialic acid or epidermal growth factor receptor expression levels, or the sialic acid density within cluster on the cell surface of A549 cells. Reversing the effect of interferon-gamma on sialic acid clustering by jasplakinolide reverted the cluster size, improved IAV attachment and replication. Our findings showed the importance of sialic acid clustering in IAV attachment and infection. We also demonstrated the interference of sialic acid clustering as an anti-IAV mechanism of IFN-gamma for IAV infection.

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IFN-γ inhibits IAV replication

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IFN-γ reduces IAV attachment and infection by reducing sialic acid cluster size

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Reduction of sialic acid cluster size partially depends on F-actin depolymerization

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Higher sialic acid expression level does not correlate with increase IAV attachment

Omicron variant susceptibility to neutralizing antibodies induced in children by natural SARS-CoV-2 infection or COVID-19 vaccine

The novel SARS-CoV-2 Omicron variant may increase the risk of re-infection and vaccine breakthrough infections as it possesses key mutations in the spike protein that affect neutralizing antibody response. Most studies on neutralization susceptibility were conducted using specimens from adult COVID-19 patients or vaccine recipients. However, since the paediatric population has an antibody response to SARS-CoV-2 infection that is distinct from the adult population, it is critical to assess the neutralization susceptibility of pediatric serum specimens. This study compared the neutralization susceptibility of serum specimens collected from 49 individuals of <18 years old, including 34 adolescent BNT162b2 (Pfizer-BioNTech) vaccine recipients, and 15 recovered COVID-19 patients aged between 2 and 17. We demonstrated that only 38.2% of BNT162b2 vaccine recipients and 26.7% of recovered COVID-19 patients had their serum neutralization titre at or above the detection threshold in our live virus microneutralization assay. Furthermore, the neutralizing antibody titer against the Omicron variant was substantially lower than those against the ancestral virus or the Beta variant. Our results suggest that vaccine recipients and COVID-19 patients in the pediatric age group will likely be more susceptible to vaccine breakthrough infections or reinfections due to the Omicron variant than previous variants.

[Epidemiological characteristics and influencing factors for high risk cardiovascular disease population in Jiangsu province]

Objective: To investigate the detection types and aggregation of high-risk population of cardiovascular disease (CVD) in Jiangsu province and the related influencing factors to provide reference for the prevention and control of cardiovascular disease. Methods: A total of 120 211 participants were included in the investigation. Information was collected by questionnaire based survey, physical examination and biochemical tests. χ² test and multivariate logistic regression were used for statistical analysis. Results: The detection rate of CVD high risk was 25.03%. The detection rates were 19.01%, 4.85%, 3.18% and 5.31% for hypertension, dyslipidemia, cardiovascular history and WHO assessed risk ≥20% types, respectively. Male, rural, old age, low education level, low family income, drinking, waist circumference exceeding standard, overweight and obesity were risk factors of CVD (all P<0.01). The composition ratios of aggregation of 1, 2 and ≥3 high risk types of CVD were 74.01%, 22.91% and 3.08%, respectively. With the increase of aggregation types, the correlation strength increased with age, rural residents, education level and annual family income. Conclusion: Targeted measures should be carried out according to different influencing factors for the prevention and control of CVD in Jiangsu province in order to achieve the maximum prevention and control effect with the minimum cost.

Neutralization of Severe Acute Respiratory Syndrome Coronavirus 2 Omicron Variant by Sera From BNT162b2 or CoronaVac Vaccine Recipients

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron variant, designated as a variant of concern by the World Health Organization, carries numerous spike mutations that are known to evade neutralizing antibodies elicited by coronavirus disease 2019 (COVID-19) vaccines. A deeper understanding of the susceptibility of omicron variant to vaccine-induced neutralizing antibodies is urgently needed for risk assessment.

METHODS

Omicron variant strains HKU691 and HKU344-R346K were isolated from patients using TMPRSS2-overexpressing VeroE6 cells. Whole genome sequence was determined using nanopore sequencing. Neutralization susceptibility of ancestral lineage A virus and the omicron, delta and beta variants to sera from 25 BNT162b2 and 25 CoronaVac vaccine recipients was determined using a live virus microneutralization assay.

RESULTS

The omicron variant strain HKU344-R346K has an additional spike R346K mutation, which is present in 8.5% of strains deposited in the GISAID database. Only 20% and 24% of BNT162b2 recipients had detectable neutralizing antibody against the omicron variant HKU691 and HKU344-R346K, respectively, whereas none of the CoronaVac recipients had detectable neutralizing antibody titer against either omicron isolate. For BNT162b2 recipients, the geometric mean neutralization antibody titers (GMTs) of the omicron variant isolates (5.43 and 6.42) were 35.7-39.9-fold lower than that of the ancestral virus (229.4), and the GMTs of both omicron variant isolates were significantly lower than those of the beta and delta variants. There was no significant difference in the GMTs between HKU691 and HKU344-R346K.

CONCLUSIONS

Omicron variant escapes neutralizing antibodies elicited by BNT162b2 or CoronaVac. The additional R346K mutation did not affect the neutralization susceptibility. Our data suggest that the omicron variant may be associated with lower COVID-19 vaccine effectiveness.

Correlation between Commercial Anti-RBD IgG Titer and Neutralization Titer against SARS-CoV-2 Beta Variant

Objectives: The emergence of SARS-CoV-2 variants of concern (VOCs) have diminished the effectiveness of vaccines and are associated with a rebound in the number of COVID-19 cases globally. These variants contain mutations at the spike (S) protein receptor binding site (RBD), which affect antibody binding. Current commercially available antibody assays were developed before the VOCs emerged. It is unclear whether the levels of these commercially available antibody assays can predict the neutralizing antibody titers against the VOCs. In this study, we sought to determine the correlation between the binding antibody concentration and microneutralization antibody titer against the beta variant. Methods: This study included 58 COVID-19 patients. The concentrations of IgG against the SARS-CoV-2 spike protein RBD and nucleocapsid (N) protein were measured using the Abbott SARS-CoV-2 IgG II Quant assay and the SARS-CoV-2 IgG assay, respectively. The neutralization antibody titer against the wild type lineage A SARS-CoV-2 and against the beta variant (B.1.351) was determined using a conventional live virus neutralization test. Results: The geometric mean MN titer (GMT) against the beta variant was significantly lower than that against the wild type lineage A virus (5.6 vs. 47.3, p < 0.0001). The anti-RBD IgG had a better correlation with the neutralizing antibody titer than that of the anti-N IgG assay against the wild type lineage A virus (Spearman rho, 0.5901 vs. 0.3827). However, the correlation between the anti-RBD or the anti-N IgG and the MN titer against the beta variant was poor. Conclusions: Currently available commercial antibody assays may not predict the level of neutralizing antibodies against the variants. A new generation of antibody tests specific for variants are required.

[Analysis on the expression profile of circRNAs in hypertrophic myocardium mice]

Objective: To explore the differential expression of circRNAs and their potential impact on the pathophysiological process in cardiac hypertrophy. Methods: Six SPF C57BL/6J male mice, aged 8 to 10 weeks, were randomly divided into transverse aortic constriction (TAC) group (n=3) or sham operation(sham) group (n=3) according to random number table method. TAC mouse model was used to induce cardiac hypertrophy. Four weeks after surgery, high-throughput sequencing analysis was performed to detect differentially expressed circRNA in left myocardial tissues of mice between TAC group and sham group, and principal component analysis of circRNA was performed by R language software. Enrichment analysis was performed by GO and KEGG databases to predict the basic functions of differentially expressed circRNA-derived genes and their biological pathways. The differentially expressed circRNAs in the sequencing results were verified by real-time fluorescence quantitative polymerase chain reaction. Cytoscape software was used to construct circRNA-microRNA (miRNA) network maps to predict their interactions by combining differentially expressed circRNA and TargetScan predicted miRNA sites. Results: Principal component analysis was performed on 4 580 circRNAs detected from 6 samples of mice in TAC group and sham group. The results of R language software indicated that the variance contribution rate of the first 3 principal components, namely the first, second and third principal components, was 91.01%, 3.19% and 2.01%, respectively, and the cumulative variance contribution rate of the 3 components was 96.21%. Among the differentially expressed circRNAs, 6 (19%) were up-regulated and 25 (81%) were down-regulated in the TAC group. GO analysis showed that differentially expressed circRNA was closely related to the occurrence and development of cardiac hypertrophy, and KEGG pathway analysis suggested that downregulated circRNA expression was involved in the regulation of actin cytoskeleton. Fifteen out of the 31 differentially expressed circRNAs were selected for real-time fluorescence quantitative polymerase chain reaction verification, and the results showed that 8 circRNAs were consistent with sequencing results. circRNA-miRNA co-expression network analysis results showed that chr11:65218529-65233184-interacts with mmu-miRNA-30e-3p and mmu-miRNA-30a-3p. Conclusions The differential expression of circRNA in hypertrophic myocardium mice is evidenced in TAC mouse model. circRNA may interact with the corresponding miRNA to influence the occurrence and development of cardiac hypertrophy through autophagy-related cellular hypertrophy pathway or apoptosis-related pathological phenotypes.

[Association between occupational hazard exposures and small airway function among middle-aged and elderly people]

Objective: To investigate the association between occupational hazard exposures and small airway function among middle-aged and elderly people. Methods: From July to December in 2015, a multistage cluster random sampling method was used to select 3 600 residents aged 40 years old and above from 6 chronic obstructive pulmonary disease surveillance points in Jiangsu province. A cross-sectional survey was conducted to collect relevant information. Multivariable linear regression model was performed to determine the relationship between occupational hazard exposures and small airway function. Results: A total of 3 347 participants were included in the final analysis, and 44.6% of participants had been exposed to occupational hazard exposures. Compared with participants without the exposure history of occupational hazards, the significantly lower post-bronchodilator FEF_50%, FEF_75% and MMEF levels were observed in those with the exposure history of occupational hazards (β=-82.74, -55.43 and -91.57, respectively). Post-bronchodilator FEF_75% and MMEF (β=-51.78 and -79.47, respectively) in the participants with the exposure history of occupational dust and post-bronchodilator FEF_50%, FEF_75% and MMEF (β=-96.84, -32.87 and -75.72, respectively) in the participants with the exposure history of occupational harmful gas all showed a lower level. Post-bronchodilator FEF_75% was negatively associated with occupational hazard exposures in males (β_male=-91.65 vs. β_female=-27.21, P for interaction=0.022). Conclusions: The small airway function is worse in the middle-aged and elderly population with the exposure history of occupational hazards, and it is more significant in the male population.