Longitudinal single cell atlas identifies complex temporal relationship between type I interferon response and COVID-19 severity

Due to the paucity of longitudinal molecular studies of COVID-19, particularly those covering the early stages of infection (Days 1-8 symptom onset), our understanding of host response over the disease course is limited. We perform longitudinal single cell RNA-seq on 286 blood samples from 108 age- and sex-matched COVID-19 patients, including 73 with early samples. We examine discrete cell subtypes and continuous cell states longitudinally, and we identify upregulation of type I IFN-stimulated genes (ISGs) as the predominant early signature of subsequent worsening of symptoms, which we validate in an independent cohort and corroborate by plasma markers. However, ISG expression is dynamic in progressors, spiking early and then rapidly receding to the level of severity-matched non-progressors. In contrast, cross-sectional analysis shows that ISG expression is deficient and IFN suppressors such as SOCS3 are upregulated in severe and critical COVID-19. We validate the latter in four independent cohorts, and SOCS3 inhibition reduces SARS-CoV-2 replication in vitro. In summary, we identify complexity in type I IFN response to COVID-19, as well as a potential avenue for host-directed therapy.

Predictors of left ventricular mass and coronary artery calcium phenotypes

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National Medical Research Council, Ministry of Health, Singapore and the Lee Foundation

Background

Left ventricular (LV) mass and coronary artery calcium score (CACS) are both independent predictors of cardiovascular risk. There is paucity of data on the interplay of risk factors on LV mass in the presence or absence of subclinical coronary atherosclerosis.

Purpose

The objective of this present study was to explore the relationship of risk factors to indexed LV mass and CACS in a healthy Southeast-Asian population.

Methods

This study recruited volunteers with no known cardiovascular disease. LV mass, measured by cardiovascular magnetic resonance, was indexed to body surface area (LVMI), and CACS determined by non-contrast CT scanning. Blood pressure (BP) was measured via both office and ambulatory monitoring, and physical activity assessed through wearable devices. Analysis of LVMI was stratified into high, normal and low defined as more than one standard deviation away from the mean for each sex, with inter-group differences evaluated using chi-squared or ANOVA statistical tests. Subjects in each LVMI group were further subdivided by the presence and absence of coronary calcification (total 6 subgroups; LVMI/CACS phenotypes).

Results

A total of 880 subjects were included, including 428 males and 452 females. There was no significant difference in prevalence of coronary calcification across the LVMI groups for males, while females with high LVMI had significantly greater proportion of positive CACS (p = 0.036). Higher LVMI was observed in younger male subjects, but not in females.

In both sexes, body mass index was positively associated with LVMI (p = 0.004 for males, p = 0.037 for females), but not CACS. Waist circumference was associated with higher LVMI in males only.

Greater amounts of weekly self-reported exercise (p = 0.006) and daily calories burned (p = 0.022) were associated with increased LVMI for males only. However, wearable-derived measures of daily physical activity and step counts did not significantly affect LVMI or LVMI/CACS phenotypes in both sexes.

BP was a strong predictor of LVMI in both sexes regardless of office or ambulatory readings, in both day and night-time. The association was also observed with LVMI/CACS phenotypes: higher systolic or diastolic BP was significantly associated with positive CACS across all risk groups. Notably, subjects with low LVMI and positive CACS were normotensive (office BP 129/82 for males, 123/77 for females).

Higher HDL cholesterol levels correlated to absence of coronary calcification in males only (p = 0.010). In females, lower levels of total (p = 0.001) and LDL (p = 0.005) cholesterol were associated with absence of coronary calcification across all LVMI categories.

Conclusion

Only BP was strongly associated with LVMI and LVMI/CACS phenotypes in both sexes. There appears to be no correlation between physical activity and LVMI/CACS phenotypes. There is a need for causative studies to better evaluate the varying influence of risk factors on LVMI and CACS.

Machine learning accurately quantifies epicardial adipose tissue from non-contrast CT images in coronary artery disease

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Industry Alignment Fund – Pre-positioning Programme

Background

Epicardial adipose tissue (EAT) is the visceral fat deposit within the pericardium that surrounds the heart and the coronary arteries. EAT volume measured from non-contrast CT (NCCT) has been demonstrated to be significantly associated with adverse cardiovascular risk,1 particularly in patients with coronary artery disease.2 However, routine measurement of EAT volume is still challenging in clinical practice, as it is a tedious manual process and prone to human error.

Purpose

We aimed to develop a fully automated AI toolkit (i.e., AI EAT) for the quantification of EAT from routine NCCT scans and assess its performance in reference to clinical ground truth.

Methods

This is a multicenter study which performs CT scans in 5000 Asian Admixture patients (APOLLO study NCT05509010). In the current stage of this study, NCCT data analysis were conducted in 551 patients with 26,037 images. AI EAT was developed via a novel deep learning framework using an ensemble region-based UNet. The region-based UNet uses 2 component UNet models to perform segmentation of pericardium at the apex region and non-apex region (middle and basal). EAT volume was obtained by automated thresholding of the voxels (-190 to -30 Hounsfield Unit) within the pericardium (Figure 1). The network was trained in 501 patients with 23,712 NCCT images and tested in 50 patients with 2,325 NCCT images. The performance of AI EAT was evaluated with respect to clinical ground truth using Dice similarity coefficient (DSC), Pearson correlation, and Bland-Altman analysis.

Results

The AI EAT quantification process took less than 10 seconds per subject, compared with 20-30 minutes for expert readers. Compared to clinical ground truth, our AI EAT achieved a DSC of 0.96±0.01 and 0.91±0.02 for pericardium and EAT segmentations, respectively. There was strong agreement between the AI EAT and clinical ground truth in deriving the EAT volume (r=0.99, P<0.001) with minimal error of 7±5%.

Conclusion

End-to-end deep learning system accurately quantifies epicardial adipose tissue in standard NCCT images without manual segmentation.

Conserved longitudinal alterations of anti-S-protein IgG subclasses in disease progression in initial ancestral Wuhan and vaccine breakthrough Delta infections

INTRODUCTION

COVID-19 has a wide disease spectrum ranging from asymptomatic to severe. While humoral immune responses are critical in preventing infection, the immune mechanisms leading to severe disease, and the identification of biomarkers of disease progression and/or resolution of the infection remains to be determined.

METHODS

Plasma samples were obtained from infections during the initial wave of ancestral wildtype SARS-CoV-2 and from vaccine breakthrough infections during the wave of Delta variant, up to six months post infection. The spike-specific antibody profiles were compared across different severity groups and timepoints.

RESULTS

We found an association between spike-specific IgM, IgA and IgG and disease severity in unvaccinated infected individuals. In addition to strong IgG1 and IgG3 response, patients with severe disease develop a robust IgG2 and IgG4 response. A comparison of the ratio of IgG1 and IgG3 to IgG2 and IgG4 showed that disease progression is associated with a smaller ratio in both the initial wave of WT and the vaccine breakthrough Delta infections. Time-course analysis revealed that smaller (IgG1 and IgG3)/(IgG2 and IgG4) ratio is associated with disease progression, while the reverse associates with clinical recovery.

DISCUSSION

While each IgG subclass is associated with disease severity, the balance within the four IgG subclasses may affect disease outcome. Acute disease progression or infection resolution is associated with a specific immunological phenotype that is conserved in both the initial wave of WT and the vaccine breakthrough Delta infections.

[Effects of celastrol on autophagy and endoplasmic reticulum stress-mediated apoptosis in a mouse model of nonalcoholic fatty liver disease]

Objective: To investigate the effect of celastrol (CEL) on autophagy and endoplasmic reticulum stress-mediated apoptosis in a mouse model of nonalcoholic fatty liver disease (NAFLD). Methods: Eighteen male C57BL/6J mice were randomly divided into normal control (NC, n=6), high-fat diet (HFD, n=6) and celastrol group (HFD+CEL, n=6). The normal control group was fed with regular diet, and the high-fat diet and celastrol group were fed with high-fat diet for 12 weeks. After successful modeling, celastrol group were injected with 100 μg⋅kg^-1⋅d^-1 celastrol intraperitoneally for 4 weeks, and NC and HFD group were injected intraperitoneally with the same doses of normal saline. Serum concentrations of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) were measured in mouse after 4-weeks of intervention. HE and Oil Red O staining were used to observe the pathomorphological changes and lipid droplet deposition in mouse liver, and the findings were scored according to NAFLD activity score (NAS). Western blot was used to detect the expression levels of liver microtubule associated protein 1 light chain 3 (LC3), P62, glucose-regulated protein 78 (GRP78), protein kinase R-like endoplasmic reticulum kinase (PERK), phosphorylated PERK (p-PERK), activated transcription factor 4 (ATF4), C/EBP homologous protein (CHOP), cleaved Caspase-3(cleaved caspase-3), B-cell lymphoma-2 (Bcl-2) and Bcl-2 related X protein (Bax).TUNEL staining was used to observe the apoptosis of hepatocytes. One-way analysis of variance was used for the intergroup comparison. Results: Serum levels of ALT (68.71±8.57) U/L, AST (209.63±28.64) U/L, TG (0.97±0.14) mmol/L, TC (4.12±0.64) mmol/L, and LDL -C (0.40±0.06) mmol/L were lower in celastrol group mouse than HFD group [(110.19±10.79) U/L, (399.72±73.47) U/L, (1.44±0.13) mmol/L, (5.65±0.54) mmol /L, (0.61±0.07) mmol/L] (P<0.05); while the serum HDL-C level (1.29±0.17) mmol/L was higher in celastrol than HFD group (0.72±0.13) mmol/L (P<0.05). HE and Oil Red O staining showed that lipid deposition and intralobular inflammation were apparent in the liver tissue of HFD group mouse, and the NAS score was significantly increased, while the hepatocyte steatosis and intralobular inflammation were alleviated after celastrol intervention, and the NAS score was decreased significantly (P<0.05). Compared with HFD group, the ratio of LC3II/I was significantly increased in the liver of celastrol group mouse, and the P62 was significantly decreased (P<0.05). Meanwhile, the expression level of GRP78, p-PERK/PERK , ATF4, and CHOP was significantly lower in celastrol than HFD group (P<0.05). In addition, the expressions of cleaved caspase-3 and Bax were significantly lower in celastrol than HFD group, and the expression of Bcl-2 was significantly increased (P<0.05). At the same time, the apoptosis rate of hepatocytes was also significantly lower in celastrol than HFD group (P<0.05). Conclusion: Celastrol can effectively alleviate the lipid deposition, protect hepatocytes and delay the progression of non-alcoholic fatty liver disease in mouse liver with non-alcoholic fatty liver disease. In addition, its mechanism of action may be related to the induction of autophagy, inhibition of endoplasmic reticulum stress PERK/ATF4/CHOP pathway and its mediated apoptosis.

Prevalence and distribution of coronary artery calcium in a southeast asian cohort

Funding Acknowledgements

Type of funding sources: None.

Background

The coronary artery calcium score (CACS) independently predicts the risk of cardiovascular disease and major adverse cardiovascular events. While previous studies have demonstrated regional and ethnic differences in coronary calcification, the distribution of CACS in Southeast Asian (SEA) adults has not been investigated.

Purpose

The aim of this study was to determine CACS distribution in a SEA cohort living in Singapore.

Methods

This study involved 4945 asymptomatic patients who underwent CT coronary angiography and calcium scoring as part of screening for cardiovascular disease. Similar to the MESA study, patients with diabetes were analyzed separately due an increased prevalence of coronary calcification. A nonparametric analytical approach was used to determine CACS distribution stratified by age, gender and ethnicity.

Results

A positive CACS was seen in 43.7% of the overall SEA cohort with a higher prevalence in males (45.2%) than females (36.7%). The onset and burden of coronary calcification was also earlier and more severe in male subjects. There were no significant differences in CACS distribution amongst the three major ethnic groups in our study (p = 0.177). The presence of coronary calcification (CACS &gt;0) was associated with increasing age, male gender and hypertension. Ethnicity, dyslipidemia, smoking and a family history of coronary artery disease did not significantly affect the presence of CACS.

Conclusions

This study provides a reference CACS distribution in an asymptomatic SEA population. There were no significant differences in CACS distribution amongst the three major ethnic groups living in Singapore.

Decreased memory B cells frequencies in COVID-19 Delta variant vaccine breakthrough infection

The SARS‐CoV‐2 Delta (B.1.617.2) variant is capable of infecting vaccinated persons. An open question remains as to whether deficiencies in specific vaccine‐elicited immune responses result in susceptibility to vaccine breakthrough infection. We investigated 55 vaccine breakthrough infection cases (mostly Delta) in Singapore, comparing them against 86 vaccinated close contacts who did not contract infection. Vaccine breakthrough cases showed lower memory B cell frequencies against SARS‐CoV‐2 receptor‐binding domain (RBD). Compared to plasma antibodies, antibodies secreted by memory B cells retained a higher fraction of neutralizing properties against the Delta variant. Inflammatory cytokines including IL‐1β and TNF were lower in vaccine breakthrough infections than primary infection of similar disease severity, underscoring the usefulness of vaccination in preventing inflammation. This report highlights the importance of memory B cells against vaccine breakthrough and suggests that lower memory B cell levels may be a correlate of risk for Delta vaccine breakthrough infection.

Data-Driven Analysis of COVID-19 Reveals Persistent Immune Abnormalities in Convalescent Severe Individuals

Severe SARS-CoV-2 infection can trigger uncontrolled innate and adaptive immune responses, which are commonly associated with lymphopenia and increased neutrophil counts. However, whether the immune abnormalities observed in mild to severely infected patients persist into convalescence remains unclear. Herein, comparisons were drawn between the immune responses of COVID-19 infected and convalescent adults. Strikingly, survivors of severe COVID-19 had decreased proportions of NKT and Vδ2 T cells, and increased proportions of low-density neutrophils, IgA+/CD86+/CD123+ non-classical monocytes and hyperactivated HLADR+CD38+ CD8+ T cells, and elevated levels of pro-inflammatory cytokines such as hepatocyte growth factor and vascular endothelial growth factor A, long after virus clearance. Our study suggests potential immune correlates of "long COVID-19", and defines key cells and cytokines that delineate true and quasi-convalescent states.

Resistance of SARS-CoV-2 variants to neutralization by convalescent plasma from early COVID-19 outbreak in Singapore

The rapid spreading of SARS-CoV-2 variants B.1.1.7 originated from the United Kingdom and B.1.351 from South Africa has contributed to the second wave of COVID-19 cases in the respective countries and also around the world. In this study, we employed advanced biochemical and virological methodologies to evaluate the impact of Spike mutations of these strains on the degree of protection afforded by humoral immune responses following natural infection of the ancestral SARS-CoV-2 strain during the early stages of the outbreak. We found that antibody-mediated neutralization activity was partially reduced for B.1.1.7 variant and significantly attenuated for the B.1.351 strain. We also found that mutations outside the receptor-binding domain (RBD) can strongly influence antibody binding and neutralization, cautioning the use of solely RBD mutations in evaluating vaccine efficacy. These findings highlight an urgent need to develop new SARS-CoV-2 vaccines that are not based exclusively on the ancestral SARS-CoV-2 Spike gene sequence.

[Research progress on the effect of selective autophagy receptor p62 on fibrotic diseases]

Selective autophagy keeps cell homeostasis by degrading aggregated proteins, damaged or over-abundant organelles, and other cytoplasmic substances. The maintenance of its normal function needs to ensure that the autophagy receptor can effectively recognize and isolate undegraded substances. As an important autophagy receptor protein, p62 participates in the process of selective autophagy by mediating multiple signaling pathways. Fibrosis is a pathological feature of most chronic inflammatory diseases. When fibrosis develops for a long time, it will cause substantial scar formation and eventually lead to cell dysfunction and organ failure. The accumulation, overexpression and ectopic expression of p62 can aggravate the occurrence and development of lung, liver and kidney fibrosis diseases. Therefore, it is very critical to explore the effect of selective autophagy receptor p62 on fibrotic diseases.

[The study of the impact by atractylenolide-1 on inflammatory cytokine, autophagy and apoptosis in alveolar macrophages of silicosis patients]

Objective: To explore the effect of atractylenolide-1 (ATL-Ⅰ) on alveolar macrophages in silicosis patients. Methods: In December 2019, 12 male silicosis patients treated in Beidaihe Sanatorium for Chinese Coal Miners from July to September 2019 were selected by random sampling. Their alveolar macrophages were collected and divided into control group, ATL-Ⅰ group (100 μmol/L) and dimethyl sulfoxide (DMSO) group (100 μmol/L) . The exprossion levels of inflammatory factor interleukin-1β (IL-1β) , interleukin-6 (IL-6) , tumor necrosis factor α (TNF-α) were detected by enzyme-linked immunosorbent assay. The expression levels of autophagy associated protein microtubule associated protein light chain 3 (LC3) , autophagy substrate protein p62, lysosome associated membrane protein 2 (LAMP2) , apoptosis associated protein Cleaved caspase-3, nuclear factor kappa B (NF-κB) and its phosphorylated form (p-NF-κB) were detected by Western blot. Results: Compared with the control group and DMSO group, the expression levels of IL-1β, IL-6, TNF-α in alveolar macrophages decreased significantly in the ATL-Ⅰ group (P<0.05) , and the expression levels of p-NF-κB, the ratio of LC3-Ⅱ/LC3-Ⅰ also decreased significantly in the ATL-Ⅰ group (P<0.05) . However, the expression levels of NF-κB, LAMP2, p62 and Cleaved caspase-3 in the ATL-Ⅰ group were not statistically different from those in the control group and DMSO group (P>0.05) . There was no statistically significant differences in the expression of the above indexes between the control group and DMSO group (P>0.05) . Conclusion: ATL-Ⅰ may reduce the release of inflammatory factors from alveolar macrophages and inhibit the activity of autophagy in silicosis patients, but it may not reduce the level of apoptosis.

A systematic review of factors influencing attitudes towards and intention to use the long-distance caregiving technologies for older adults

PURPOSE

Long-distance caregiving (LDC) technologies play a significant role in enabling distant care and facilitating living-alone older adults to keep socially connected. However, there is scarce research exploring the older adults' attitudes towards and intention to use such technologies. This paper is based on a systematic review of existing literature to explore the multifarious factors influencing independent community-living older adults' attitudes towards and intention to use LDC technologies.

METHODS

Articles published in English between 2006 and 2020 were reviewed by searching electronic databases of PubMed, ProQuest, EBSCOhost. The inclusion criteria were limited to quantitative, qualitative, or mixed-methods studies that involved: 1) distant caregiving; 2) older adults aged 60 years or above, who were living alone or with only their spouse in the community (even though the samples might also involve other non-older adults); 3) technologies including ICT-based devices, systems, or programs enabling data transmission were used; 4), intention to use or behavioral usage in regard to the technologies were reported or discussed.

RESULTS

In total, 41 out of 8674 articles were included. Both determinants and moderators of affecting the use of the ICT-based LDC technologies were identified with theoretical guidance. To summarize, there are personal factors involved, such as personality, concerns regarding security and privacy, health conditions, requisite knowledge, financial conditions, and influence from significant others, encompassing formal and informal caregivers; and factors related to the devices, in terms of their user-friendliness and functionality.

CONCLUSION

This review highlights the importance of striking a good balance between functionality and privacy concerns, besides considering the direct and indirect cost to users. LDC technology education should be promoted at the societal level to facilitate older adults' better understanding of the device utilities by enhancing their technological literacy. Implications for various stakeholders to cope with the challenges of an aging population are also discussed.

Differential Cytokine Responses in Hospitalized COVID-19 Patients Limit Efficacy of Remdesivir

A significant proportion of COVID-19 patients will progress to critical illness requiring invasive mechanical ventilation. This accentuates the need for a therapy that can reduce the severity of COVID-19. Clinical trials have shown the effectiveness of remdesivir in shortening recovery time and decreasing progression to respiratory failure and mechanical ventilation. However, some studies have highlighted its lack of efficacy in patients on high-flow oxygen and mechanical ventilation. This study uncovers some underlying immune response differences between responders and non-responders to remdesivir treatment. Immunological analyses revealed an upregulation of tissue repair factors BDNF, PDGF-BB and PIGF-1, as well as an increase in ratio of Th2-associated cytokine IL-4 to Th1-associated cytokine IFN-γ. Serological profiling of IgG subclasses corroborated this observation, with significantly higher magnitude of increase in Th2-associated IgG2 and IgG4 responses. These findings help to identify the mechanisms of immune regulation accompanying successful remdesivir treatment in severe COVID-19 patients.

Convalescent COVID-19 patients are susceptible to endothelial dysfunction due to persistent immune activation

Numerous reports of vascular events after an initial recovery from COVID-19 form our impetus to investigate the impact of COVID-19 on vascular health of recovered patients. We found elevated levels of circulating endothelial cells (CECs), a biomarker of vascular injury, in COVID-19 convalescents compared to healthy controls. In particular, those with pre-existing conditions (e.g., hypertension, diabetes) had more pronounced endothelial activation hallmarks than non-COVID-19 patients with matched cardiovascular risk. Several proinflammatory and activated T lymphocyte-associated cytokines sustained from acute infection to recovery phase, which correlated positively with CEC measures, implicating cytokine-driven endothelial dysfunction. Notably, we found higher frequency of effector T cells in our COVID-19 convalescents compared to healthy controls. The activation markers detected on CECs mapped to counter receptors found primarily on cytotoxic CD8⁺ T cells, raising the possibility of cytotoxic effector cells targeting activated endothelial cells. Clinical trials in preventive therapy for post-COVID-19 vascular complications may be needed.

ABO-Incompatible Living-Donor Kidney Transplantation in a Developing Country: A Multicenter Experience in Malaysia

Malaysia has a low deceased-donor donation rate and has not embarked on a paired kidney exchange program; therefore, ABO-incompatible and HLA-incompatible transplantation remain the main contributor to the sustainability of the national kidney transplantation (KT) program. There were 26 cases of ABO-incompatible KTs performed from 2011 to 2018 in 3 major transplant centers, namely, Hospital Kuala Lumpur, University Malaya Medical Centre, and Prince Court Medical Centre. We collected perioperative and follow-up data through June 2019. The desensitization protocol varies and is center specific: the localized Japanese protocol and Swedish protocol with a target anti-A/B isoagglutinin titer of 16 or 32 on the day of transplant. The induction and tacrolimus-based maintenance protocol was nearly identical. The median follow-up time was 62.3 months (interquartile range, 37.0-79.7). Fifteen subjects had the highest predesensitization anti-A/B titer of ≥32 (57.7%). The acute cellular rejection and antibody-mediated rejection incidence were 12.5% (3 cases) and 8.3% (2 cases), respectively. Patient, graft, and death-censored graft survival rates were 96.2%, 92.3%, and 96.0%, respectively, 1 year post-living-donor KT (LDKT) and 96.2%, 87.2%, and 90.7%, respectively, 5 years post-LDKT. Our experience shows that ABO-incompatible LDKT using a suitable desensitization technique could be a safe and feasible choice for LDKT even with varied desensitization regimens for recipients with relatively high baseline isoagglutinin titers.

Sensitive detection of total anti-Spike antibodies and isotype switching in asymptomatic and symptomatic individuals with COVID-19

Early detection of infection is crucial to limit the spread of coronavirus disease 2019 (COVID-19). Here we develop a flow cytometry-based assay to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein antibodies in individuals with COVID-19. The assay detects specific immunoglobulin M (IgM), IgA, and IgG in individuals with COVID-19 and also acquisition of all IgG subclasses, with IgG1 being the most dominant. The antibody response is significantly higher at a later stage of infection. Furthermore, asymptomatic individuals with COVID-19 also develop specific IgM, IgA, and IgG, with IgG1 being the most dominant subclass. Although the antibody levels are lower in asymptomatic infection, the assay is highly sensitive and detects 97% of asymptomatic infections. These findings demonstrate that the assay can be used for serological analysis of symptomatic and asymptomatic infections, which may otherwise remain undetected.

Flow cytometry assay detects specific antibodies in symptomatic individuals with COVID-19

Asymptomatic individuals with COVID-19 also develop specific antibodies

IgG1 is the dominant IgG subclass in symptomatic and asymptomatic individuals

The assay is highly sensitive and detects 97% of asymptomatic infections

[The clinical characteristics of 89 cases of non-tuberculous mycobacterium pulmonary disease complicated with tracheobronchial lesions]

Objective: To explore the clinical characteristics of non-tuberculous mycobacterium(NTM) pulmonary disease complicated with tracheobronchial lesions. Methods: From January 2014 to December 2018, there were 1 006 patients who were admitted to Guangzhou Chest Hospital for the first time and received examination by bronchoscopy. A total of 89 patients with complete data were selected, including 40 males and 49 females, aged 20 to 85 years, with 46 patients (52%) aged 60 years or older. The clinical symptoms and signs of the patients were analyzed with chest imaging, bronchoscopy and pathological examination results. Comparisons between groups were made by Chi-square test and t test. Results: The number of patients with NTM complicated with tracheobronchial lesions accounted for 8.9%(89/1 006) of those hospitalized with NTM and received bronchoscopy during the same period. Clinical symptoms included cough and sputum (89/89), different degrees of hemoptysis or blood sputum (52/89), and shortness of breath (50/89). Chest CT showed that 72 cases (72/89, 81%) had lung lesions involving more than 3 lung fields, and 83 cases (93%) had bronchiectasis and 63 cases (63/89, 71%) with cavities. Pulmonary atelectasis was shown in 45 cases (45/89, 51%). By bronchoscopy, 39 cases (39/89, 44%) were diagnosed as tuberculous lesions involving bilateral upper bronchi, while lesions of the right lower bronchus was found in 27 cases (27/89, 30%).The percentage of patients with multilobar bronchial involvement was 50.6%(45/89). The morphological characteristics of the bronchial lesions included scar stenosis or atresia in 63 cases (63/89, 71%), hyperemia and edema in 46 cases (46/89, 52%), and multiple types of lesions in 48 cases (48/89, 54%). Conclusions: Patients with NTM lung disease complicated with tracheobronchial inflammatory lesions did not have specific manifestations clinically. Lung lesions are extensive, often accompanied by bronchiectasis and cavity formation. Endoscopic changes were mostly manifested as multilobar tracheobronchial involvement characterized by scar stenosis, congestion and edema, mainly involving bilateral upper bronchi and the right lower bronchus.

A Cost-Effective Alternative for Lateral Femoral Wall Perforation in Anterior Cruciate Ligament (ACL) Reconstruction: A Case Report

Lateral femoral wall perforation is a rare intra-operative complication in anterior cruciate ligament (ACL) reconstruction surgery. However, it can be challenging to manage if it occurs. We share our experience on lateral femoral wall perforation managed by a large fragment washer. A 25-year-old man with right ACL injury presented with knee instability despite physiotherapy. Anterior drawer test (ADT) and Lachman test were grade 3, glide on pivot shift was positive. During ACL reconstruction, the lateral femoral wall was perforated. Due to unavailability of the rescue endobutton and budget constraint, we passed the endobutton through a washer and allowed it to sit on the washer over the lateral femoral wall. ADT and Lachman test on post-operative 6, 12 and 24 weeks were grade 1, with a negative pivot shift test. Lysholm knee score improved from 69 pre-operatively to 98 post-operatively. Conventionally, lateral femoral wall perforation can be managed by rescue endobutton, or screw and washer post technique. As this complication is rare, the rescue endobutton may not be available at all times, and the cost of the implant is also another important factor to consider. A washer can be used as an alternative technique to manage lateral femoral wall perforation in ACL reconstruction as it is not only cost-effective but also provides stable fixation with good functional outcome.

Two linear epitopes on the SARS-CoV-2 spike protein that elicit neutralising antibodies in COVID-19 patients

Given the ongoing SARS-CoV-2 pandemic, identification of immunogenic targets against the coronavirus spike glycoprotein will provide crucial advances towards the development of sensitive diagnostic tools and potential vaccine candidate targets. In this study, using pools of overlapping linear B-cell peptides, we report two IgG immunodominant regions on SARS-CoV-2 spike glycoprotein that are recognised by sera from COVID-19 convalescent patients. Notably, one is specific to SARS-CoV-2, which is located in close proximity to the receptor binding domain. The other region, which is localised at the fusion peptide, could potentially function as a pan-SARS target. Functionally, antibody depletion assays demonstrate that antibodies targeting these immunodominant regions significantly alter virus neutralisation capacities. Taken together, identification and validation of these neutralising B-cell epitopes will provide insights towards the design of diagnostics and vaccine candidates against this high priority coronavirus.

[Treatment of postprandial discomfort syndrome in the elderly: a multi-centered prospective randomized controlled clinical study]

Objective: To evaluate the efficacy and safety of Oryz-Aspergillus enzyme and pancreatin tablets (Combizym(®)) in the treatment of postprandial distress syndrome (PDS) in the elderly, compared with gastrointestinal motility drugs. Methods: A prospective randomized controlled trial was designed and registered in the China Clinical Trials Registry (ChiCTR-IPR-16008185). The elderly patients with PDS were randomly divided into three groups, including Mosapride group with Mosapride citrate tablets 5 mg 3 times per day for 2 weeks; Combizym(®) group with Combizym tablets 244 mg 3 times per day for 2 weeks; combined treatment group with both drugs and same doses for 2 weeks. The modified Nepean dyspepsia index (NDSI) score, discomfort intensity score and PDS score were calculated on patients before treatment, at the end of first and second week of treatment, as well as 4 weeks after treatment finished, respectively. Adverse effects were evaluated. Results: A total of 323 patients from 16 tertiary hospitals in China were enrolled in this study. Among them, 105 patients were in Mosapride group, 109 in Combizym(®) group and 109 in combined treatment group. There were 148 males (45.8%) and 175 females (54.2%) with median age 71.4±9.0 years (60-100 years). Baseline characteristics of three groups were comparable. After treatment, the NDSI scores in three groups all decreased significantly (P<0.001), while they were similar between groups (P>0.05). The discomfort intensity score and PDS score in three groups showed a significant reduction after treatment (P<0.001), especially in the combined treatment group. Compared with Mosapride group, the scores in Combizym(®) group decreased significantly after one or two weeks [discomfort intensity score: after one week, 4.0(2.5, 8.0) vs. 6.0(3.0, 10.0); after two weeks, 3.0(0.0, 5.0) vs. 4.0(2.0, 6.0); all P<0.05. PDS score: after one week, 6.0(3.0, 9.0) vs. 7.0(3.5, 10.5); after two weeks, 3.0(0.0, 5.0) vs. 4.0(2.0, 7.0); all P<0.05]. The efficacy rate in all patients after first week of treatment was over 15.0%. The efficacy rates after two weeks were 55.2%, 68.8% and 73.4% in Mosapride group, Combizym(®) group and combined treatment group, respectively. After two week treatment, the efficacy rates in Combizym(®) group (P=0.041) and combined group (P=0.006) were higher than that of Mosapride group. The recurrence rate of Mosapride group was 9.5%, which was significantly higher than that of Combizym(®) group (1.8%, P<0.05) and combined treatment group (1.8%, P<0.05). There were no serious adverse effects in the three groups. Conclusions: The efficacy of Oryz-Aspergillus enzyme and pancreatin tablets is comparable with that of Mosapride in elderly PDS patients, with fewer adverse effects and low recurrence rate. Combination regimen indicates better efficacy than that of Oryz-Aspergillus enzyme and pancreatin tablets or Mosapride alone.

Decreased expression of SorCS1 in colorectal cancer: An independent predictor of poor prognosis

Previously, we identified that sortilin related VPS10 domain containing receptor 1 (SorCS1) was hypermethylated in colorectal cancer (CRC) tissues. Here, we aimed to investigate the association between CRC and SorCS1. DNA methylation was determined by methylation-specific polymerase chain reaction (MSP) or quantitative real-time methylation analysis (MethyLight). Colorectal cancer tissue specimens from 239 patients that had undergone surgical treatment were evaluated using immunohistochemistry (IHC) analysis for the expression of SorCS1 and correlated with clinicopathological variables and prognosis. We found that SorCS1 was hypermethylated in CRC cell lines and 67.5% (27/40) CRC tumor tissues. The loss of SorCS1 mRNA (p<0.001) and protein expression (p=0.033) were highly correlated with promoter methylation. In addition, SorCS1 expression was significantly increased in younger patients (p=0.006), low CEA level (p<0.001) and pT1-2 stage (p=0.005). Survival analysis revealed that decreased expression of SorCS1 was an independent factor for predicting the increased risk of recurrence (p=0.024) and poor overall survival (p=0.006). Subgroup analysis for CEA level, pT and pN classifications showed that SorCS1 retained its stratified significance only in patients with low CEA level, pT3-4 tumors and pN1-2 lymph node status. Our findings suggest that SorCS1 is epigenetically inactivated in a substantial fraction of CRC, and its expression may be a promising prognostic factor in CRC patients.