A receptor-binding domain-based nanoparticle vaccine elicits durable neutralizing antibody responses against SARS-CoV-2 and variants of concern

Numerous vaccines have been developed to address the current COVID-19 pandemic, but safety, cross-neutralizing efficacy, and long-term protectivity of currently approved vaccines are still important issues. In this study, we developed a subunit vaccine, ASD254, by using a nanoparticle vaccine platform to encapsulate the SARS-CoV-2 spike receptor-binding domain (RBD) protein. As compared with the aluminum-adjuvant RBD vaccine, ASD254 induced higher titers of RBD-specific antibodies and generated 10- to 30-fold more neutralizing antibodies. Mice vaccinated with ASD254 showed protective immune responses against SARS-CoV-2 challenge, with undetectable infectious viral loads and reduced typical lesions in lung. Besides, neutralizing antibodies in vaccinated mice lasted for at least one year and were effective against various SARS-CoV-2 variants of concern, including B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.617.2 (Delta), and B.1.1.529 (Omicron). Furthermore, particle size, polydispersity index, and zeta-potential of ASD254 remained stable after 8-month storage at 4°C. Thus, ASD254 is a promising nanoparticle vaccine with good immunogenicity and stability to be developed as an effective vaccine option in controlling upcoming waves of COVID-19.

Development of AAV-delivered broadly neutralizing anti-human ACE2 antibodies against SARS-CoV-2 variants

The ongoing evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), resulting in the emergence of new variants that are resistant to existing vaccines and therapeutic antibodies, has raised the need for novel strategies to combat the persistent global COVID-19 epidemic. In this study, a monoclonal anti-human angiotensin-converting enzyme 2 (hACE2) antibody, ch2H2, was isolated and humanized to block the viral receptor-binding domain (RBD) binding to hACE2, the major entry receptor of SARS-CoV-2. This antibody targets the RBD-binding site on the N terminus of hACE2 and has a high binding affinity to outcompete the RBD. In vitro, ch2H2 antibody showed potent inhibitory activity against multiple SARS-CoV-2 variants, including the most antigenically drifted and immune-evading variant Omicron. In vivo, adeno-associated virus (AAV)-mediated delivery enabled a sustained expression of monoclonal antibody (mAb) ch2H2, generating a high concentration of antibodies in mice. A single administration of AAV-delivered mAb ch2H2 significantly reduced viral RNA load and infectious virions and mitigated pulmonary pathological changes in mice challenged with SARS-CoV-2 Omicron BA.5 subvariant. Collectively, the results suggest that AAV-delivered hACE2-blocking antibody provides a promising approach for developing broad-spectrum antivirals against SARS-CoV-2 and potentially other hACE2-dependent pathogens that may emerge in the future.

Human ACE2 protein is a molecular switch controlling the mode of SARS-CoV-2 transmission

BACKGROUND

Human angiotensin-converting enzyme 2 (hACE2) is the receptor mediating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. hACE2 expression is low in the lungs and is upregulated after SARS-CoV-2 infection. How such a hACE2-limited pulmonary environment supports efficient virus transmission and how dynamic hACE2 expression affects SARS-CoV-2 infection are unclear.

METHODS

We generated stable cell lines with different expression levels of hACE2 to evaluate how the hACE2 expression level can affect SARS-CoV-2 transmission.

RESULTS

We demonstrated that the hACE2 expression level controls the mode of SARS-CoV-2 transmission. The hACE2-limited cells have an advantage for SARS-CoV-2 shedding, which leads to cell-free transmission. By contrast, enhanced hACE2 expression facilitates the SARS-CoV-2 cell-to-cell transmission. Furthermore, this cell-to-cell transmission is likely facilitated by hACE2-containing vesicles, which accommodate numerous SARS-CoV-2 virions and transport them to neighboring cells through intercellular extensions.

CONCLUSIONS

This hACE2-mediated switch between cell-free and cell-to-cell transmission routes provides SARS-CoV-2 with advantages for either viral spread or evasion of humoral immunity, thereby contributing to the COVID-19 pandemic and pathogenesis.

Natural fucoidans inhibit coronaviruses by targeting viral spike protein and host cell furin

Fucoidans are a class of long chain sulfated polysaccharides and have multiple biological functions. Herein, four natural fucoidans extracted from Fucus vesiculosus, F. serratus, Laminaria japonica and Undaria pinnatifida, were tested for their HCoV-OC43 inhibition and found to demonstrate EC50 values ranging from 0.15 to 0.61 µg/mL. That from U. pinnatifida exhibited the most potent anti-HCoV-OC43 activity with an EC50 value of 0.15 ± 0.02 µg/mL, a potency largely independent of its sulfate content. Comparison of the gene expression profiles of fucoidan-treated and untreated cells infected with HCoV-OC43 revealed that fucoidan treatment effectively diminished HCoV-OC43 gene expressions associated with induced chemokines, cytokines and viral activities. Further studies using a highly fucoidan-resistant HCoV-OC43 determined that fucoidan inhibited HCoV-OC43 infection via interfering with viral entry and led to the identification of the specific site on the N-terminal region of spike protein, that located adjacent to the host cell receptor binding domain, targeted by the virus. Furthermore, in a SARS-CoV-2 pseudovirus neutralization assay, fucoidan also blocked SARS-CoV-2 entry. In vitro and in vivo, fucoidan decreased SARS-CoV-2 viral loads and inhibited viral infection in Calu-3 or Vero E6 cells and SARS-CoV-2 infected hamsters, respectively. Fucoidan was also found to inhibit furin activity, and reported furin inhibitors were found to inhibit viral infection by wild type HCoV-OC43 or SARS-CoV-2. Accordingly, we conclude that fucoidans inhibit coronaviral infection by targeting viral spike protein and host cell furin to interfere with viral entry.

Optimization and Improvement of qPCR Detection Sensitivity of SARS-CoV-2 in Saliva

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been a major public health threat globally, especially during the beginning of the pandemic in 2020. Reverse transcription-quantitative PCR (RT-qPCR) is utilized for viral RNA detection as part of control measures to limit the spread of COVID-19. Collecting nasopharyngeal swabs for RT-qPCR is a routine diagnostic method for COVID-19 in clinical settings, but its large-scale implementation is hindered by a shortage of trained health professionals. Despite concerns over its sensitivity, saliva has been suggested as a practical alternative sampling approach to the nasopharyngeal swab for viral RNA detection. In this study, we spiked saliva from healthy donors with inactivated SARS-CoV-2 from an international standard to evaluate the effect of saliva on viral RNA detection. On average, the saliva increased the cycle threshold (CT) values of the SARS-CoV-2 RNA samples by 2.64 compared to the viral RNA in viral transport medium. Despite substantial variation among different donors in the effect of saliva on RNA quantification, the outcome of the RT-qPCR diagnosis was largely unaffected for viral RNA samples with CT values of <35 (1.55 log10 IU/mL). The saliva-treated viral RNA remained stable for up to 6 h at room temperature and 24 h at 4°C. Further supplementing protease and RNase inhibitors improved the detection of viral RNA in the saliva samples. Our data provide practical information on the storage conditions of saliva samples and suggest optimized sampling procedures for SARS-CoV-2 diagnosis. IMPORTANCE The primary method for detection of SARS-CoV-2 is using nasopharyngeal swabs, but a shortage of trained health professionals has hindered its large-scale implementation. Saliva-based nucleic acid detection is a widely adopted alternative, due to its convenience and minimally invasive nature, but the detection limit and direct impact of saliva on viral RNA remain poorly understood. To address this gap in knowledge, we used a WHO international standard to evaluate the effect of saliva on SARS-CoV-2 RNA detection. We describe the detection profile of saliva-treated SARS-CoV-2 samples under different storage temperatures and incubation periods. We also found that adding protease and RNase inhibitors could improve viral RNA detection in saliva. Our research provides practical recommendations for the optimal storage conditions and sampling procedures for saliva-based testing, which can improve the efficiency of COVID-19 testing and enhance public health responses to the pandemic.

Longitudinal Neutralizing Antibody Responses after SARS-CoV-2 Infection: A Convalescent Cohort Study in Taiwan

Background

Understanding the neutralizing antibody (NAb) titer against COVID-19 over time is important to provide information for vaccine implementation. The longitudinal NAb titer over one year after SARS-CoV-2 infection is still unclear. The purposes of this study are to evaluate the duration of the neutralizing NAb titers in COVID-19 convalescents and factors associated with the titer positive duration.

Methods

A cohort study followed COVID-19 individuals diagnosed between 2020 and 2021 May 15th from the COVID-19 database from the Taiwan Centers for Disease Control. We analyzed NAb titers from convalescent SARS-CoV-2 individuals. We used generalized estimating equations (GEE) and a Cox regression model to summarize the factors associated with NAb titers against COVID-19 decaying in the vaccine-free population.

Results

A total of 203 convalescent subjects with 297 analytic samples were followed for a period of up to 588 days. Our study suggests that convalescent COVID-19 in individuals after more than a year and four months pertains to only 25% of positive titers. The GEE model indicates that longer follow-up duration was associated with a significantly lower NAb titer. The Cox regression model indicated the disease severity with advanced condition was associated with maintaining NAb titers (adjusted hazard ratio: 2.08, 95% CI: 1.12–3.61) and that non-smoking also was associated with maintaining NAb titers (adjusted hazard ratio: 1.69, 95% CI: 1.08–2.64).

Conclusions

Neutralizing antibody titers diminished after more than a year. The antibody titer response against SARS-CoV-2 in naturally convalescent individuals provides a reference for vaccinations.

Upregulation of PD-L1 by SARS-CoV-2 promotes immune evasion

Patients with severe COVID-19 often suffer from lymphopenia, which is linked to T-cell sequestration, cytokine storm, and mortality. However, it remains largely unknown how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces lymphopenia. Here, we studied the transcriptomic profile and epigenomic alterations involved in cytokine production by SARS-CoV-2-infected cells. We adopted a reverse time-order gene coexpression network approach to analyze time-series RNA-sequencing data, revealing epigenetic modifications at the late stage of viral egress. Furthermore, we identified SARS-CoV-2-activated nuclear factor-κB (NF-κB) and interferon regulatory factor 1 (IRF1) pathways contributing to viral infection and COVID-19 severity through epigenetic analysis of H3K4me3 chromatin immunoprecipitation sequencing. Cross-referencing our transcriptomic and epigenomic data sets revealed that coupling NF-κB and IRF1 pathways mediate programmed death ligand-1 (PD-L1) immunosuppressive programs. Interestingly, we observed higher PD-L1 expression in Omicron-infected cells than SARS-CoV-2 infected cells. Blocking PD-L1 at an early stage of virally-infected AAV-hACE2 mice significantly recovered lymphocyte counts and lowered inflammatory cytokine levels. Our findings indicate that targeting the SARS-CoV-2-mediated NF-κB and IRF1-PD-L1 axis may represent an alternative strategy to reduce COVID-19 severity.

A booster dose of Delta × Omicron hybrid mRNA vaccine produced broadly neutralizing antibody against Omicron and other SARS-CoV-2 variants

BACKGROUND

With the continuous emergence of new SARS-CoV-2 variants that feature increased transmission and immune escape, there is an urgent demand for a better vaccine design that will provide broader neutralizing efficacy.

METHODS

We report an mRNA-based vaccine using an engineered "hybrid" receptor binding domain (RBD) that contains all 16 point-mutations shown in the currently prevailing Omicron and Delta variants.

RESULTS

A booster dose of hybrid vaccine in mice previously immunized with wild-type RBD vaccine induced high titers of broadly neutralizing antibodies against all tested SARS-CoV-2 variants of concern (VOCs). In naïve mice, hybrid vaccine generated strong Omicron-specific neutralizing antibodies as well as low but significant titers against other VOCs. Hybrid vaccine also elicited CD8+/IFN-γ+ T cell responses against a conserved T cell epitope present in wild type and all VOCs.

CONCLUSIONS

These results demonstrate that inclusion of different antigenic mutations from various SARS-CoV-2 variants is a feasible approach to develop cross-protective vaccines.

A multitope SARS-COV-2 vaccine provides long-lasting B cell and T cell immunity against Delta and Omicron variants

Background

The Delta and Omicron variants of SARS-CoV-2 are currently responsible for breakthrough infections due to waning immunity. We report phase I/II trial results of UB-612, a multitope subunit vaccine containing S1-RBD-sFc protein and rationally designed promiscuous peptides representing sarbecovirus conserved helper T cell and cytotoxic T lymphocyte epitopes on the nucleocapsid (N), membrane (M), and spike (S2) proteins.

Method

We conducted a phase I primary 2-dose (28 days apart) trial of 10, 30, or 100 μg UB-612 in 60 healthy young adults 20 to 55 years old, and 50 of them were boosted with 100 μg of UB-612 approximately 7 to 9 months after the second dose. A separate placebo-controlled and randomized phase II study was conducted with 2 doses of 100 μg of UB-612 (n = 3,875, 18–85 years old). We evaluated interim safety and immunogenicity of phase I until 14 days after the third (booster) dose and of phase II until 28 days after the second dose.

Results

No vaccine-related serious adverse events were recorded. The most common solicited adverse events were injection site pain and fatigue, mostly mild and transient. In both trials, UB-612 elicited respective neutralizing antibody titers similar to a panel of human convalescent sera. The most striking findings were long-lasting virus-neutralizing antibodies and broad T cell immunity against SARS-CoV-2 variants of concern (VoCs), including Delta and Omicron, and a strong booster-recalled memory immunity with high cross-reactive neutralizing titers against the Delta and Omicron VoCs.

Conclusion

UB-612 has presented a favorable safety profile, potent booster effect against VoCs, and long-lasting B and broad T cell immunity that warrants further development for both primary immunization and heterologous boosting of other COVID-19 vaccines.

Trial Registration

ClinicalTrials.gov: NCT04545749, NCT04773067, and NCT04967742.

Funding

UBI Asia, Vaxxinity Inc., and Taiwan Centers for Disease Control, Ministry of Health and Welfare.

NK cell receptor and ligand composition influences the clearance of SARS-CoV-2

To explore how the immune system controls clearance of SARS-CoV-2, we used a single-cell, mass cytometry-based proteomics platform to profile the immune systems of 21 patients who had recovered from SARS-CoV-2 infection without need for admission to an intensive care unit or for mechanical ventilation. We focused on receptors involved in interactions between immune cells and virus-infected cells. We found that the diversity of receptor repertoires on natural killer (NK) cells was negatively correlated with the viral clearance rate. In addition, NK subsets expressing the receptor DNAM1 were increased in patients who more rapidly recovered from infection. Ex vivo functional studies revealed that NK subpopulations with high DNAM1 expression had cytolytic activities in response to target cell stimulation. We also found that SARS-CoV-2 infection induced the expression of CD155 and nectin-4, ligands of DNAM1 and its paired coinhibitory receptor TIGIT, which counterbalanced the cytolytic activities of NK cells. Collectively, our results link the cytolytic immune responses of NK cells to the clearance of SARS-CoV-2 and show that the DNAM1 pathway modulates host-pathogen interactions during SARS-CoV-2 infection.

Structure-guided antibody cocktail for prevention and treatment of COVID-19

Development of effective therapeutics for mitigating the COVID-19 pandemic is a pressing global need. Neutralizing antibodies are known to be effective antivirals, as they can be rapidly deployed to prevent disease progression and can accelerate patient recovery without the need for fully developed host immunity. Here, we report the generation and characterization of a series of chimeric antibodies against the receptor-binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. Some of these antibodies exhibit exceptionally potent neutralization activities in vitro and in vivo, and the most potent of our antibodies target three distinct non-overlapping epitopes within the RBD. Cryo-electron microscopy analyses of two highly potent antibodies in complex with the SARS-CoV-2 spike protein suggested they may be particularly useful when combined in a cocktail therapy. The efficacy of this antibody cocktail was confirmed in SARS-CoV-2-infected mouse and hamster models as prophylactic and post-infection treatments. With the emergence of more contagious variants of SARS-CoV-2, cocktail antibody therapies hold great promise to control disease and prevent drug resistance.

Effective approaches to mitigate the COVID-19 pandemic are a pressing global need. One promising strategy is to combine neutralizing antibodies that can reduce viral load to prevent disease progression and accelerate patient recovery. However, the current supply of therapeutic antibodies for COVID-19 is insufficient to fill the enormous demand, and escape mutants may compromise the utility of existing drugs. Thus, there is an urgent worldwide need to develop highly potent neutralizing antibody cocktails. We generated a series of chimeric antibodies against the receptor-binding domain (RBD) of SARS-CoV-2 spike protein, which potently neutralize authentic SARS-CoV-2 infection according to the plaque reduction neutralization test (PRNT) and pseudovirus-based inhibition assay. These antibodies can be classified into three distinct groups based on their targets within the receptor-binding motif. Cryo-electron microscopy structural analyses of two representative receptor-binding domain-chimeric antibodies in complex with the SARS-CoV-2 spike protein further revealed two sets of non-overlapping epitopes, suggesting the potential for their combination in a therapeutic antibody cocktail. The prophylactic and therapeutic effects of these antibodies and their combination were demonstrated in SARS-CoV-2-infected mouse and hamster models. Thus, our potent neutralizing antibody cocktail has strong potential for development as an effective therapeutic drug to prevent and treat SARS-CoV-2 infection.

Hyperglycosylated spike of SARS-CoV-2 gamma variant induces breast cancer metastasis

SARS-CoV-2 exploits the host cellular machinery for virus replication leading to the acute syndrome of coronavirus disease 2019 (COVID-19). Growing evidence suggests SARS-CoV-2 also exacerbates many chronic diseases, including cancers. As mutations on the spike protein (S) emerged as dominant variants that reduce vaccine efficacy, little is known about the relation between SARS-CoV-2 virus variants and cancers. Compared to the SARS-CoV-2 wild-type, the Gamma variant contains two additional NXT/S glycosylation motifs on the S protein. The hyperglycosylated S of Gamma variant is more stable, resulting in more significant epithelial-mesenchymal transition (EMT) potential. SARS-CoV-2 infection promoted NF-κB signaling activation and p65 nuclear translocation, inducing Snail expression. Pharmacologic inhibition of NF-κB activity by nature food compound, I3C suppressed viral replication and Gamma variant-mediated breast cancer metastasis, indicating that NF-κB inhibition can reduce chronic disease in COVID-19 patients. Our study revealed that the Gamma variant of SARS-CoV-2 activates NF-κB and, in turn, triggers the pro-survival function for cancer progression.

Safety and immunogenicity of CpG 1018 and aluminium hydroxide-adjuvanted SARS-CoV-2 S-2P protein vaccine MVC-COV1901: interim results of a large-scale, double-blind, randomised, placebo-controlled phase 2 trial in Taiwan

Background

MVC-COV1901, a recombinant protein vaccine containing pre-fusion-stabilised spike protein S-2P adjuvanted with CpG 1018 and aluminium hydroxide, has been shown to be well tolerated with a good safety profile in healthy adults aged 20–49 years in a phase 1 trial, and provided a good cellular and humoral immune responses. We present the interim safety, tolerability, and immunogenicity results of a phase 2 clinical trial of the MVC-COV1901 vaccine in Taiwan.

Methods

This is a large-scale, double-blind, randomised, placebo-controlled phase 2 trial done at ten medical centres and one regional hospital in Taiwan. Individuals aged 20 years or older who were generally healthy or had stable pre-existing medical conditions were eligible for enrolment. Exclusion criteria included (but were not limited to) travel overseas within 14 days of screening, intention to travel overseas within 6 months of the screening visit, and the absence of prespecified medical conditions, including immunosuppressive illness, a history of autoimmune disease, malignancy with risk to recur, a bleeding disorder, uncontrolled HIV infection, uncontrolled hepatitis B and C virus infections, SARS-CoV-1 or SARS-CoV-2 infections, an allergy to any vaccine, or a serious medical condition that could interfere with the study. Study participants were randomly assigned (6:1) to receive two doses of either MVC-COV1901 or placebo, administered via intramuscular injection on day 1 and day 29. MVC-COV1901 contained 15 μg of S-2P protein adjuvanted with 750 μg CpG 1018 and 375 μg aluminium hydroxide in a 0·5 mL aqueous solution, and the placebo contained the same volume of saline. Randomisation was done centrally by use of an interactive web response system, stratified by age (≥20 to <65 years and ≥65 years). Participants and investigators were masked to group assignment. The primary outcomes were to evaluate the safety, tolerability, and immunogenicity of MVC-COV1901 from day 1 (the day of the first dose) to day 57 (28 days after the second dose). Safety was assessed in all participants who received at least one dose. Immunogenicity was assessed by measuring geometric mean titres (GMTs) and seroconversion rates of neutralising antibody and antigen-specific IgG in the per-protocol population. This study is registered with ClinicalTrials.gov, NCT04695652.

Findings

Of 4173 individuals screened between Dec 30, 2020, and April 2, 2021, 3854 were enrolled and randomly assigned: 3304 to the MVC-COV1901 group and 550 to the placebo group. A total of 3844 participants (3295 in the MVC-COV1901 group and 549 in the placebo group) were included in the safety analysis set, and 1053 participants (903 and 150) had received both doses and were included in the per-protocol immunogenicity analysis set. From the start of this phase 2 trial to the time of interim analysis, no vaccine-related serious adverse events were recorded. The most common solicited adverse events in all study participants were pain at the injection site (2346 [71·2%] of 3295 in the MVC-COV1901 group and 128 [23·3%] of 549 in the placebo group), and malaise or fatigue (1186 [36·0%] and 163 [29·7%]). Fever was rarely reported (23 [0·7%] and two [0·4%]). At 28 days after the second dose of MVC-COV1901, the wild-type SARS-CoV-2 neutralising antibody GMT was 662·3 (95% CI 628·7–697·8; 408·5 IU/mL), the GMT ratio (geometric mean fold increase in titres at day 57 vs baseline) was 163·2 (155·0–171·9), and the seroconversion rate was 99·8% (95% CI 99·2–100·0).

Interpretation

MVC-COV1901 has a good safety profile and elicits promising immunogenicity responses. These data support MVC-COV1901 to enter phase 3 efficacy trials.

Funding

Medigen Vaccine Biologics and Taiwan Centres for Disease Control, Ministry of Health and Welfare.

Vaccinia virus-based vaccines confer protective immunity against SARS-CoV-2 virus in Syrian hamsters

COVID-19 in humans is caused by Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that belongs to the beta family of coronaviruses. SARS-CoV-2 causes severe respiratory illness in 10-15% of infected individuals and mortality in 2-3%. Vaccines are urgently needed to prevent infection and to contain viral spread. Although several mRNA- and adenovirus-based vaccines are highly effective, their dependence on the "cold chain" transportation makes global vaccination a difficult task. In this context, a stable lyophilized vaccine may present certain advantages. Accordingly, establishing additional vaccine platforms remains vital to tackle SARS-CoV-2 and any future variants that may arise. Vaccinia virus (VACV) has been used to eradicate smallpox disease, and several attenuated viral strains with enhanced safety for human applications have been developed. We have generated two candidate SARS-CoV-2 vaccines based on two vaccinia viral strains, MVA and v-NY, that express full-length SARS-CoV-2 spike protein. Whereas MVA is growth-restricted in mammalian cells, the v-NY strain is replication-competent. We demonstrate that both candidate recombinant vaccines induce high titers of neutralizing antibodies in C57BL/6 mice vaccinated according to prime-boost regimens. Furthermore, our vaccination regimens generated TH1-biased immune responses in mice. Most importantly, prime-boost vaccination of a Syrian hamster infection model with MVA-S and v-NY-S protected the hamsters against SARS-CoV-2 infection, supporting that these two vaccines are promising candidates for future development. Finally, our vaccination regimens generated neutralizing antibodies that partially cross-neutralized SARS-CoV-2 variants of concern.

Remdesivir and Cyclosporine Synergistically Inhibit the Human Coronaviruses OC43 and SARS-CoV-2

Remdesivir, a prodrug targeting RNA-dependent-RNA-polymerase, and cyclosporine, a calcineurin inhibitor, individually exerted inhibitory activity against human coronavirus OC43 (HCoV-OC43) in HCT-8 and MRC-5 cells at EC₅₀ values of 96 ± 34 ∼ 85 ± 23 nM and 2,920 ± 364 ∼ 4,419 ± 490 nM, respectively. When combined, these two drugs synergistically inhibited HCoV-OC43 in both HCT-8 and MRC-5 cells assayed by immunofluorescence assay (IFA). Remdesivir and cyclosporine also separately reduced IL-6 production induced by HCoV-OC43 in human lung fibroblasts MRC-5 cells with EC₅₀ values of 224 ± 53 nM and 1,292 ± 352 nM, respectively; and synergistically reduced it when combined. Similar trends were observed for SARS-CoV-2, which were 1) separately inhibited by remdesivir and cyclosporine with respective EC₅₀ values of 3,962 ± 303 nM and 7,213 ± 143 nM by IFA, and 291 ± 91 nM and 6,767 ± 1,827 nM by a plaque-formation assay; and 2) synergistically inhibited by their combination, again by IFA and plaque-formation assay. Collectively, these results suggest that the combination of remdesivir and cyclosporine merits further study as a possible treatment for COVID-19 complexed with a cytokine storm.

Small Structural Proteins E and M Render the SARS-CoV-2 Pseudovirus More Infectious and Reveal the Phenotype of Natural Viral Variants

The SARS-CoV-2 pseudovirus is a commonly used strategy that mimics certain biological functions of the authentic virus by relying on biological legitimacy at the molecular level. Despite the fact that spike (S), envelope (E), and membrane (M) proteins together wrap up the SARS-CoV-2 virion, most of the reported pseudotype viruses consist of only the S protein. Here, we report that the presence of E and M increased the virion infectivity by promoting the S protein priming. The S, E, and M (SEM)-coated pseudovirion is spherical, containing crown-like spikes on the surface. Both S and SEM pseudoviruses packaged the same amounts of viral RNA, but the SEM virus bound more efficiently to cells stably expressing the viral receptor human angiotensin-converting enzyme II (hACE2) and became more infectious. Using this SEM pseudovirus, we examined the infectivity and antigenic properties of the natural SARS-CoV-2 variants. We showed that some variants have higher infectivity than the original virus and that some render the neutralizing plasma with lower potency. These studies thus revealed possible mechanisms of the dissemination advantage of these variants. Hence, the SEM pseudovirion provides a useful tool to evaluate the viral infectivity and capability of convalescent sera in neutralizing specific SARS-CoV-2 S dominant variants.

P–522 Cervical secretion methylation profile is associated with the success of frozen-thawed embryo transfer - a proof-of-concept study

Study question

Is cervical secretion gene methylation profile different between receptive and non-receptive endometrium and associated with implantation outcome in frozen-embryo transfer (FET) cycle?

Summary answer

The combination of candidate genes methylation profiles obtained from cervical secretion showed significant associations with pregnancy outcomes.

What is known already

Implantation failure remains a black box in reproductive medicine, and the exact mechanism of how endometrial receptivity is regulated is still unknown. Epigenetic modifications play a role in the gene expression pattern and may alter the endometrial receptivity in the human endometrium. Cervical secretion containing various implantation-related cytokines, and the gene methylation change can be used as a non-invasive molecular source that reflects the endometrium condition.

Study design, size, duration

In this retrospective case-control study, sixty-two women who entered the FET cycle (30 pregnant and 32 non-pregnant women) were enrolled.

Participants/materials, setting, methods

Cervical secretion was collected before embryo transfer from women enrolled in multicenter university-affiliated reproductive units. The DNA methylation status of six candidate genes was measured using quantitative methylation-specific PCR (qMSP). The correlation between methylation change and the pregnancy outcome was analyzed.

Main results and the role of chance

The candidate genes were selected from that associated with implantation with literature review and the original genome-wide DNA methylation data from NCBI GEO DataSets (GSE90060) which processed using bioinformatics analysis. Six candidate genes whose CpG-level methylation analysis with β-value statistically higher in receptive endometrium than in a pre-receptive endometrium were selected. All six candidate genes showed different degrees of correlation with the pregnancy outcomes. Among them, PRKAG2 methylation changes showed the highest correlation with the pregnancy outcome. A logistic regression model was used to evaluate the performance of a single gene or a combination of genes for implantation prediction. The results showed a statistically significant association between the methylation status of a combination of genes (PRKAG2, KRS1, HAND2) and the pregnancy outcome (p = 0.008), resulting in an optimal AUC of 0.7 (95% CI: 0.57 - 0.81) for implantation prediction.

Limitations, reasons for caution

The results obtained from a relatively small cohort size. A larger study and further comprehensive methylome investigations are warranted.

Wider implications of the findings: This study is the first proof-of-concept study that cervical secretion methylation profile is associated with implantation outcome in a FET cycle, and showed potential as a non-invasive method for implantation prediction.

Trial registration number

non applicable

Epithelial-mesenchymal transition induced by SARS-CoV-2 required transcriptional upregulation of Snail

The engagement of human angiotensin-converting enzyme 2 (hACE2) and SARS-CoV-2 spike protein facilitate virus spread. Thus far, ACE2 and TMPRSS2 expression is correlated with the epithelial-mesenchymal transition (EMT) gene signature in lung cancer. However, the mechanism for SARS-CoV-2-induced EMT has not been thoroughly explored. Here, we showed that SARS-CoV-2 induces EMT phenotypic change and stemness in breast cancer cell model and subsequently identified Snail as a modulator for this regulation. The in-depth analysis identifies the spike protein (S), but not envelope (E), nucleocapsid (N), or membrane protein (M), of SARS-CoV-2 induces EMT marker changes. Suppression of Snail expression in these cells abrogates S protein-induced invasion, migration, stemness, and lung metastasis, suggesting that Snail is required for SARS-CoV-2-mediated aggressive phenotype in cancer. This study reveals an important oncogenic role of SARS-CoV-2 in triggering breast cancer metastasis through Snail upregulation.

Correction: Multi-targeting of functional cysteines in multiple conserved SARS-CoV-2 domains by clinically safe Zn-ejectors

[This corrects the article DOI: 10.1039/D0SC02646H.].

CpG-adjuvanted stable prefusion SARS-CoV-2 spike protein protected hamsters from SARS-CoV-2 challenge

The COVID-19 pandemic presents an unprecedented challenge to global public health. Rapid development and deployment of safe and effective vaccines are imperative to control the pandemic. In the current study, we applied our adjuvanted stable prefusion SARS-CoV-2 spike (S-2P)-based vaccine, MVC-COV1901, to hamster models to demonstrate immunogenicity and protection from virus challenge. Golden Syrian hamsters immunized intramuscularly with two injections of 1 µg or 5 µg of S-2P adjuvanted with CpG 1018 and aluminum hydroxide (alum) were challenged intranasally with SARS-CoV-2. Prior to virus challenge, the vaccine induced high levels of neutralizing antibodies with 10,000-fold higher IgG level and an average of 50-fold higher pseudovirus neutralizing titers in either dose groups than vehicle or adjuvant control groups. Six days after infection, vaccinated hamsters did not display any weight loss associated with infection and had significantly reduced lung pathology and most importantly, lung viral load levels were reduced to lower than detection limit compared to unvaccinated animals. Vaccination with either 1 μg or 5 μg of adjuvanted S-2P produced comparable immunogenicity and protection from infection. This study builds upon our previous results to support the clinical development of MVC-COV1901 as a safe, highly immunogenic, and protective COVID-19 vaccine.

Novel Naturally Occurring Mutations of Enterovirus 71 Associated With Disease Severity

Infection with the re-emerging enterovirus 71 (EV-A71) is associated with a wide range of disease severity, including herpangina, encephalitis, and cardiopulmonary failure. At present, there is no FDA-approved therapeutics for EV-A71. Early diagnosis for the high-risk children is the key to successful patient care. We examined viral genome sequences at the 5′ untranslated region (UTR) and the capsid protein VP1 from 36 mild and 27 severe cases. We identified five EV-A71 mutations associated with severe diseases, including (1) the 5′ UTR mutations C580U, A707G, C709U; (2) a VP1 alanine-to-threonine mutation at position 280 (280T), and (3) a VP1 glutamic acid-to-(non-glutamic acid) at position 145 [145(non-E)]. SCARB2 is a known entry receptor for EV-A71. Based on a recent cryoEM structure of the EV-A71-SCARB2 binding complex, VP1-280T is near the binding interface between the VP1-VP2 complex and its entry receptor SCARB2. A de novo created hydrogen bonding between the mutant VP1-280T and the VP2-139T, could help strengthen a web-like interaction structure of the VP1-VP2 complex. A stabilized loop turn of VP2, once in contact with SCARB2, can enhance interaction with the host SCARB2 receptor for viral entry. Our findings here could facilitate early detection of severe cases infected with EV-A71 in clinical medicine. In addition, it opens up the opportunity of functional studies via infectious cDNA cloning, site-directed mutagenesis, and animal models in the future.

Inhibition of SARS-CoV-2 by Highly Potent Broad-Spectrum Anti-Coronaviral Tylophorine-Based Derivatives

Tylophorine-based compounds and natural cardiotonic steroids (cardenolides and bufadienolides) are two classes of transmissible gastroenteritis coronavirus inhibitors, targeting viral RNA and host cell factors, respectively. We tested both types of compounds against two types of coronaviruses, to compare and contrast their antiviral properties, and with view to their further therapeutic development. Examples of both types of compounds potently inhibited the replication of both feline infectious peritonitis virus and human coronavirus OC43 with EC₅₀ values of up to 8 and 16 nM, respectively. Strikingly, the tylophorine-based compounds tested inhibited viral yields of HCoV-OC43 to a much greater extent (7-8 log magnitudes of p.f.u./ml) than the cardiotonic steroids (about 2-3 log magnitudes of p.f.u./ml), as determined by end point assays. Based on these results, three tylophorine-based compounds were further examined for their anti-viral activities on two other human coronaviruses, HCoV-229E and SARS-CoV-2. These three tylophorine-based compounds inhibited HCoV-229E with EC₅₀ values of up to 6.5 nM, inhibited viral yields of HCoV-229E by 6-7 log magnitudes of p.f.u./ml, and were also found to inhibit SARS-CoV-2 with EC₅₀ values of up to 2.5-14 nM. In conclusion, tylophorine-based compounds are potent, broad-spectrum inhibitors of coronaviruses including SARS-CoV-2, and could be used for the treatment of COVID-19.

A traditional Chinese medicine formula NRICM101 to target COVID-19 through multiple pathways: A bedside-to-bench study

COVID-19 is a global pandemic, with over 50 million confirmed cases and 1.2 million deaths as of November 11, 2020. No therapies or vaccines so far are recommended to treat or prevent the new coronavirus. A novel traditional Chinese medicine formula, Taiwan Chingguan Yihau (NRICM101), has been administered to patients with COVID-19 in Taiwan since April 2020. Its clinical outcomes and pharmacology have been evaluated. Among 33 patients with confirmed COVID-19 admitted in two medical centers, those (n = 12) who were older, sicker, with more co-existing conditions and showing no improvement after 21 days of hospitalization were given NRICM101. They achieved 3 consecutive negative results within a median of 9 days and reported no adverse events. Pharmacological assays demonstrated the effects of the formula in inhibiting the spike protein/ACE2 interaction, 3CL protease activity, viral plaque formation, and production of cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α. This bedside-to-bench study suggests that NRICM101 may disrupt disease progression through its antiviral and anti-inflammatory properties, offering promise as a multi-target agent for the prevention and treatment of COVID-19.

Hypoxia and therapeutic treatment of EV-A71 with an immune modulator TLR7 agonist in a new immunocompetent mouse model

Background

Enterovirus 71 (EV71 or EV-A71) was first identified in California about half a century ago. In recent years, outbreaks of EV-A71 were prevalent worldwide, including Taiwan, Malaysia, Singapore, Japan, and China. Between 2008 and 2011, China alone reported 1894 deaths associated with EV-A71 infection. In mild cases, EV-A71 can cause herpangina and hand-foot-and-mouth disease (HFMD). However, in severe cases, it could cause neurological disorders, including meningitis and encephalitis. Cardiopulmonary failure is common among hospitalized children with EV-A71 infection. No effective FDA-approved therapeutics against EV-A71 are clinically available.

Methods

We report the establishment of an immunocompetent wild type strain 129 (wt-129) mouse model, which can be cross-species infected with human EV-A71 clinical isolates via an intraperitoneal route.

Results

One intriguing disease phenotype of this new model is the development of characteristic “White-Jade” patches in the muscle, which lost sporadically the normal pink color of uninfected muscle. Viral VP1 protein and massive leukocyte infiltration were detected in muscles with or without white-jades. We demonstrated further that hypoxia is a general phenomenon associated with white-jades in both immunocompetent and immunodeficient mouse models. Therefore, hypoxia appears to be a feature intrinsic to EV-A71 infection, irrespective of its host’s immunogenetic background. To date, no effective treatment for EV-A71 is available. Here, using this new wt-129 mouse model, we showed that timely treatment with compound R837 (a TLR7 immune modulator) via oral or intraperitoneal routes, rescued the hypoxia, limb paralysis, and death at a high therapeutic efficacy.

Conclusions

In this new immunocompetent mouse 129 model, we observed an unexpected white-jade phenotype and its associated hypoxia. The successful treatment with TLR7 immune modulators via an oral route, provide us a new research direction for EV-A71 basic science and translational research. It remains an open issue whether R837 or its related compounds, will be a promising drug candidate in clinical trials in EV-A71 endemic or epidemic areas in the future.

Imaging Validation of Drug-Eluting Beads Transarterial Chemoembolization of Hepatocellular Carcinomas in Living Donor Liver Transplantation

OBJECTIVE

The aim of this study is to determine whether post-transarterial chemoembolization imaging (computed tomography or magnetic resonance imaging) could accurately predict the tumors' necrosis on pathologic specimens.

BACKGROUND

Transarterial chemoembolization with drug-eluting beads has been proven to be an effective way to bridge patients with hepatocellular carcinomas to liver transplantation.

MATERIALS AND METHODS

From September 2012 to June 2017, 59 patients with a total of 78 hepatocellular carcinomas, who received transarterial chemoembolization with drug-eluting beads before liver transplantation in Kaohsiung Chang Gung Memorial Hospital, were included in the study. All patients and hepatocellular carcinomas have pre-transarterial chemoembolization and post-transarterial chemoembolization images (computed tomography or magnetic resonance imaging) and pathological findings for correlation. Tumor response was evaluated according to modified Response Evaluation Criteria in Solid Tumors. The ranges of necrotic percentage are 100%, 91-99%, 51-90%, and <50%.

RESULTS

The accuracy rate between the imaging and pathology correlation was 40% for computed tomography and 42% for magnetic resonance imaging. The recurrent rate of the complete respond group is 11.5%, the partial respond group is 16.0%, and the stationary group is 28.6%.

CONCLUSION

Computed tomography and magnetic resonance imaging sensitivity is not satisfactory for microscopic evaluation of residual tumors after transarterial chemoembolization with drug-eluting beads. However, survival is good after liver transplantation no matter what the microscopic findings were.

[Role and mechanism of hydrogen sulfide in cigarette smoke induced chronic obstructive pulmonary disease related pulmonary vascular remodeling in rats]

Objective: To investigate the role and mechanism of hydrogen sulfide (H2S) in rats with chronic obstructive pulmonary disease (COPD) related pulmonary vascular remodeling. Methods: Twenty four healthy male Sprague-Dawley rats were randomly divided into 4 groups: control group, cigarette smoke (CS) group, CS+ Sodium hydrosulfide (NaHS) group and CS+ DL-propargylglycine (PPG) group. Rats in control group were fed normally and breathed clear air, and for the rest groups, passive cigarette smoke inhalation method were adopted to establish COPD model. After 8 weeks, the rats in corresponding groups were treated by NaHS or PPG. After 16 weeks, the markers of pulmonary vascular remodeling in all groups were measured. Proliferation marker proliferative cell nuclear antigen (PCNA) and oxidative stress marker 3-neurotrophin (3-NT) in all groups were measured by immunohistochemistry (IHC). Results: Compared with control group, the airway resistance was increased (0.859±0.283 vs 0.578±0.088, P<0.05) and the pathological scores was much higher in CS group, which suggested that the COPD model was successful. The degree of small resistance pulmonary artery medial wall thickness and full vascular muscularization of CS group were much higher (0.54±0.20 vs 0.37±0.12, 0.39±0.08; 0.61±0.16 vs 0.20±0.12, 0.34±0.13, all P<0.01)than control group and CS+ NaHS group, there was no significant difference between CS+ PPG group and CS group. In accordance with the results of morphometric analysis, the proliferation marker PCNA was more in CS group when compared with control group and CS+ NaHS group (0.27±0.08 vs 0.12±0.06, 0.14±0.06, both P<0.05), there was no significant difference between CS+ PPG group and CS group. Furthermore, the IHC also showed that 3-NT significantly increased in CS group compared with control group and CS+ NaHS group (0.26±0.08 vs 0.18±0.04, 0.19±0.06, both P<0.01), there was no significant difference between CS+ PPG group and CS group as well. In addition, the small resistance pulmonary artery medial wall thickness had strong correlation with the expression level of oxidative stress marker 3-NT (r=0.906, P<0.001). Conclusion: H2S significantly attenuates cigarette smoke induced COPD related pulmonary vascular remodeling, which could be related to its ability to decrease oxidative stress.

A new animal model containing human SCARB2 and lacking stat-1 is highly susceptible to EV71

Enterovirus 71 (EV71) is a major threat to children worldwide. Children infected with EV71 could develop subclinical infection and hand-foot-and -mouth disease (HFMD). In severe cases, patients could develop encephalitis, paralysis, pulmonary edema, and death. A more user-friendly and robust animal model is essential to investigating EV71 pathogenesis. Here, we established a hybrid (hSCARB2(+/+)/stat-1(-/-)) mouse strain from crossbreeding SCARB2 transgenic and stat-1 KO mice, and compared the susceptibilities to EV71 infection and pathogenesis between parental and hybrid mice. Virus-encoded VP1 protein can be detected in the streaking nerve fibers in brain and spinal cord. This hybrid mouse strain at 2-week-old age can still be infected with different genotypes of EV71 at 1000-fold lower titer via an ip route. Infected hybrid mice developed earlier onset of CNS disease, paralysis, and death at a higher incidence. These advantages of this novel model meet the urgent need from the scientific community in basic and preclinical research in therapeutics and pathogenesis.

Providing instrumental social support is more beneficial to reduce mortality risk among the elderly with low educational level in Taiwan: a 12-year follow-up national longitudinal study

BACKGROUND

To evaluate whether the effects of providing or receiving social support are more beneficial to reduce mortality risk among the elderly with different educational levels.

METHODS

In this long-term prospective cohort study, data were retrieved from the Taiwan Longitudinal Study on Aging. This study was initiated from 1996 until 2007. The complete data from 1492 males and 1177 females aged ≥67 years were retrieved. Participants received financial, instrumental, and emotional support, and they actively provided instrumental and emotional support to others and involved in social engagement. Education attainment was divided into two levels: high and low. The low education level included illiterate and elementary school. The high education level included junior high school to senior high school and above college. Cox regression analysis was used to examine the association between providing or receiving social support on mortality with different educational levels.

RESULTS

The average age of the participants in 1996 was 73.0 (IQR=8.0) years, and the median survival following years (1996-2007) of participants was 10.3 (IQR=6.7) years. Most participants were low educational level including illiterate (39.3%) and elementary school (41.2%). Participants with high educational level tend to be younger and more male significantly. On the contrary, participants with low educational level tend to have significant more poor income, more depression, more cognition impairment, more with IADL and ADL disability than high educational level. Most participants received instrumental support from others (95.5%) and also provided emotional support to others (97.7%). Providing instrumental support can reduce 17% of mortality risk among the elderly with a low level of education after adjusting several covariates [Hazard ratio (HR) = 0.83; 95% confidence interval (CI) = 0.70-0.99; p = 0.036].

CONCLUSIONS

Providing instrumental social support to others confer benefits to the giver and prolong life expectancy among the elderly with low educational levels.

Outcomes after surgery in patients with previous stroke

BACKGROUND

Limited information is available on the association between a medical history of stroke and postoperative outcomes. This study investigated the outcomes following non-neurological surgery in patients with previous stroke.

METHODS

Using Taiwan's National Health Insurance Research Database, a nationwide cohort study was conducted of patients who underwent non-neurological surgery between 2008 and 2010 with a medical history of stroke in the 24-month period before operation. Patients who had non-neurological surgeries without previous stroke were selected as controls by the propensity score-matched pair method. Thirty-day postoperative complications and in-hospital mortality were compared between the two groups.

RESULTS

Some 1 426 795 adults underwent major inpatient non-neurological surgery, of whom 45 420 had a medical history of previous stroke. Patients with previous stroke who underwent surgery had an increased risk of postoperative pneumonia, septicaemia, acute renal failure, acute myocardial infarction, pulmonary embolism and 30-day in-hospital mortality (adjusted rate ratio (RR) 1·79, 95 per cent c.i. 1·61 to 1·99). Compared with controls, patients with previous stroke due to intracerebral haemorrhage (RR 3·41, 2·97 to 3·91), and those who were treated in intensive care (RR 2·55, 2·24 to 2·90) or underwent neurosurgery (RR 2·49, 2·12 to 2·92), had an increased 30-day in-hospital mortality rate. Postoperative mortality also increased with stroke-related co-morbidities, and with stroke 1-6 months before surgery (RR 3·31, 2·91 to 3·75).

CONCLUSION

Patients with previous stroke had a higher risk of adverse postoperative outcomes; their 30-day in-hospital mortality rate was nearly twice that of patients without previous stroke.

Density-driven spontaneous streak segregation patterns in a thin rotating drum

Granular mixtures may segregate because of external driving forces, which play an important role in industry and geophysics. We investigate experimentally the mechanism of density-driven spontaneous streak segregation patterns in a thin rotating drum. We find that a spontaneous streak segregation pattern can occur in such a system, which we call a D-system. A phase diagram identifies three segregation pattern regimes in this study: the mixing regime, the core segregation regime, and the streak segregation regime.

The acoustic radiation force impulse elastography evaluation of liver fibrosis in posttransplantation dysfunction of living donor liver transplantation

BACKGROUND

The acoustic radiation force impulse elastography (ARFI) is a new technology of elastography integrated into B-mode ultrasonography. It has been a reliable method to evaluate liver fibrosis of chronic liver disease in recent years, but less applied in the posttransplantation liver. The aim of the study was to evaluate liver fibrosis by the ARFI with correlation of pathological stages in living donor liver transplantation (LDLT).

MATERIALS AND METHODS

From August 2010 to August 2012, there were 57 LDLT patients with liver biopsy (LB) due to posttransplantation dysfunction; all patients also received posttransplantation ARFI liver stiffness measurement (LSM) after transplantation for liver fibrosis staging. The ARFI elastography was performed using a Siemens Acuson S2000 ultrasound system with 4V1 transducers (Acusion, Siemens Medical Systems Co. Ltd. Erlangen, Germany). The ARFI LSM value was presented by shear wave velocity (SWV, m/s). The fibrosis staging as F0 to F4 was in accordance with the Metavir scoring system.

RESULTS

A total of 57 patients had both posttransplantation LB and effective ARFI fibrosis staging for correlation. The ARFI LSM value increased with severity of liver fibrosis and had significant linear correlation with the results of histological fibrosis staging. The ARFI LSM sensitivities (Se), specificities (Sp), and cutoff values based on receiver-operator characteristic curve were F0: 0.75 m/s (Se: 93.8%, Sp: 4%), F1: 1.06 m/s (Se: 95.5%, Sp: 25.7%), F2: 1.81 m/s (Se: 50%, Sp: 83.6%) and F3: 2.33 m/s (Se: 100%, Sp: 92.9%). Predictive value of ARFI LSM reported a significant difference between early fibrosis stage (F0-F1) and advanced fibrosis stage (F ≧ 2) (P < .05).

CONCLUSION

In this study, ARFI demonstrated a strong linear correlation and severity of liver fibrosis with LB pathologic staging. ARFI can be an alternative and compensatory method for frequent LB in the posttransplantation liver.

Postoperative adverse outcomes after non-hepatic surgery in patients with liver cirrhosis

BACKGROUND

Postoperative adverse outcomes in patients with liver cirrhosis are not completely understood. This study evaluated the association between liver cirrhosis and adverse outcomes after non-hepatic surgery.

METHODS

Reimbursement claims were used to identify patients with preoperative liver cirrhosis who underwent non-hepatic surgery from 2004 to 2007. Control patients without cirrhosis were matched by age, sex, type of surgery and anaesthesia. The adjusted odds ratios (ORs) and 95 per cent confidence intervals (c.i.) of postoperative adverse events associated with liver cirrhosis were analysed by multivariable logistic regression.

RESULTS

Thirty-day mortality rates among 24 282 patients with cirrhosis and 97 128 control patients were 1·2 per cent (299 deaths) and 0·7 per cent (635 deaths) respectively. Liver cirrhosis was associated with postoperative 30-day mortality (OR 1·88, 95 per cent c.i. 1·63 to 2·16), acute renal failure (OR 1·52, 1·34 to 1·74), septicaemia (OR 1·42, 1·33 to 1·51) and intensive care unit admission (OR 1·39, 1·33 to 1·45). Postoperative mortality increased in patients who had liver cirrhosis with viral hepatitis (OR 2·87, 1·55 to 5·30), alcohol dependence syndrome (OR 3·74, 2·64 to 5·31), jaundice (OR 5·47, 3·77 to 7·93), ascites (OR 5·85, 4·62 to 7·41), gastrointestinal haemorrhage (OR 3·01, 2·33 to 3·90) and hepatic coma (OR 5·11, 3·79 to 6·87).

CONCLUSION

Patients with liver cirrhosis had increased mortality and complications after non-hepatic surgery, particularly those with cirrhosis-related clinical indicators.

Adverse postoperative outcomes in surgical patients with immune thrombocytopenia

Background

Patients with immune thrombocytopenia (ITP) are likely to have various medical co-morbidities, yet their global features regarding adverse postoperative outcomes and use of medical resources when undergoing major surgery are unknown. The objective of this study was to validate whether ITP is an independent risk factor for adverse postoperative outcomes, and to explore the potential clinical predictors of outcomes after major surgery among patients with ITP.

Methods

A retrospective population-based cohort study was conducted using Taiwan's National Health Insurance Research Database, controlling for preoperative co-morbidities by means of multiple logistic regression. Major postoperative complication and mortality rates, and in-hospital medical costs were analysed.

Results

The study included 11 085 surgical patients with ITP and 44 340 controls without ITP matched for sex, age, and type of surgery and anaesthesia. Surgical patients with ITP had a higher risk of postoperative death (odds ratio (OR) 1·89, 95 per cent confidence interval 1·57 to 2·27), and overall postoperative complications (OR 1·47, 1·39 to 1·56), and increased hospital stay (OR 1·90, 1·80 to 2·01), admission to the intensive care unit (OR 1·73, 1·63 to 1·83) and medical costs (OR 1·89, 1·79 to 1·99). Amount of preoperative platelet and/or red blood cell transfusion, emergency visits and admission to hospital for ITP care were identified as risk factors for adverse postoperative outcomes.

Conclusion

Patients with ITP undergoing surgery are at increased risk of adverse perioperative events, particularly if blood or blood product transfusion are required preoperatively, or the procedure is done as an emergency.

Using mass spectrometry to detect buffalo salivary odorant-binding protein and its post-translational modifications

A large number of mammalian odorant-binding proteins, which are lipocalins, have been studied. These proteins participate in peri-receptor events by selecting and carrying odorant molecules. The present study aimed at identifying the buffalo salivary odorant-binding protein (sOBP), and to determine its post-translational modification using mass spectrometry. The buffalo salivary 21  kDa protein was initially separated adopting sodium dodecyl sulfate-polyacrylamide gel electrophoresis and it was identified as sOBP with high statistical reliability using liquid chromatography/tandem mass spectrometry (LC/MS/MS) and SEQUEST, for the first time. Further, the post-translationally modified peptides were screened adopting MS/MS. A total of four post-translational modifications, namely glycation at lysine-(59), hydroxylation at lysine-(134), ubiquitination at lysine-(121), and dihydroxylation in lysine-(108), were recorded. Moreover, these modifications have not been identified in buffalo salivary odorant-binding protein.

Granular dynamics of a slurry in a rotating drum

We study the effects of interstitial fluid viscosity on the rates of dynamical processes in a thin rotating drum half-filled with monodisperse glass beads. The rotating speed is fixed at the rolling regime such that a continuously flowing layer of beads persists at the free surface. While the characteristic speed of a bead in the flowing layer decreases with the fluid viscosity μ, the mixing rate of the beads is found to increase with μ. These findings are consistent to a simple model related to the thickness of the flowing layer. In addition, our results indicate a possible transition from the inertial limit regime to the viscous limit regime (reported previously by S. Courrech du Pont [Phys. Rev. Lett. 90, 044301 (2003)]) when the Stokes number is reduced.

Dose reconstruction for residents living in buildings with moderate and minor 60Co contamination in rebar

Previously, we have reconstructed cohort dependent individual doses for residents living in rebar buildings of high 60Co contamination. These reconstructions were carried out using intensively collected TLD data on exposure rates at locations of 1 m height and 1 m x 1 m intersections. The present work deals with dose reconstructions for residents living in rebar buildings of moderate and minor 60Co contamination. Since only limited data on exposure rates from survey meters were available, dose reconstructions were based on these data using interpolations. To utilize such data, we examined them with respect to all factors that influenced the dose uncertainties. The interpolated results were given in terms of contour plots (isodose curves) and compared with corresponding results derived from TLD data and Monte Carlo simulations. The comparison revealed that survey meter data could be used to provide reasonable and conservative estimates of residential doses. By applying the cohort-dependent room occupancy factor and the site-dependent area occupancy factor, we reconstructed cohort dependent individual doses and associated uncertainties. Results of dose reconstructions for all residents living in contaminated rebar buildings were provided to the Atomic Energy Council and health authorities for epidemiologic and medical uses.

Laser-induced reorientation effect and ripple structure in dye-doped liquid-crystal films

The effects of light-induced reorientation on a homeotropical dye-doped liquid crystal (DDLC) cell are discussed. The photoexcited azo dye Methyl Red (MR) is diffused and adsorbed onto the substrate, thus forming a ripple structure. The adsorbed dye and the laser-induced ripple structure then reorient the liquid-crystal molecules and induce a holographic grating. Initially, the liquid-crystal directors are reoriented primarily by the adsorbed dye. However, given a sufficiently large ripple groove amplitude, the torque imposed by the ripple grooves overcomes that which is due to the adsorbed dyes, and the liquid crystals are realigned along the groove direction.

Dynamic studies of holographic gratings in dye-doped liquid-crystal films

The dynamic behavior of a holographic grating induced in a homeotropically aligned dye-doped liquid-crystal film is investigated. In the presence of an applied dc voltage, photoexcited azo dyes induce a photorefractive grating and then diffuse and are adsorbed onto cell substrates. The reorientation of liquid crystals as a result of adsorbed dyes leads to a phase grating that is phase shifted 90 degrees from the photorefractive grating. Competition of these two gratings induces two-beam coupling of the writing beams, initially transferring energy from beam 1 to beam 2 and then, after a pause, from beam 2 to beam 1.

The hetero Diels-Alder reactions of masked o-benzoquinones with nitroso compounds

The first examples of hetero Diels-Alder reaction of masked o-benzoquinones with nitroso dienophiles leading to novel and highly functionalized heterocycles, which are potential intermediates for nitrogenous natural products are reported.

Study on the secondary structure of protein in amide I band from human colon cancer tissue by Fourier-transform infrared spectroscopy

BACKGROUND

Fourier-transform infrared spectroscopy (FT-IR) is a powerful tool for study of the secondary conformation of intact protein in biological tissues and for diagnosis of disease states. The purpose of this study is to utilize FT-IR as a diagnostic tool to estimate the secondary structure of amide I in normal and cancer tissue of human colon.

METHODS

Pairs of tissue samples from colon cancer and histologically normal mucosa tissue 5-10 cm from the tumor were obtained from a patient who underwent partial colectomy. In the present study we investigated the changes in the secondary structure of amide I of normal and malignant human colon tissue using FT-IR microspectroscopy with attenuated total reflectance. Secondary-derivative analysis relative to the original and curve-fitting analysis infrared spectra were also carried out.

RESULTS

The conformational changes of the secondary structure of protein in normal and cancerous human colon tissue were (1) the composition of alpha-helixes increased in human cancerous colon tissue (15.30%) compared to normal colon tissue (11.72%); (2) beta-sheets which were 46.8% in healthy tissue decreased to 30.71% in cancer tissue; (3) beta-turns increased from 26.28% in normal tissue to 38.48% in cancer tissue; and (4) the composition of random coils was not significantly different between normal tissue (15.12%) and cancer tissue (15.51%).

CONCLUSION

Our data demonstrate that protein in colon cancer displays abnormal FT-IR spectra. The conformational changes of the secondary structure of this protein in terms of alpha-helixes, beta-sheets and beta-turns were observed in normal and cancerous tissue from the same individual were compared.

Processing of DNase domain during translocation of colicin E7 across the membrane of Escherichia coli

Translocation of colicin across the membrane of sensitive cells has been studied extensively. However, processing of the toxicity domain of colicin during translocation has been the subject of much controversy. To investigate the final translocation product of colicin across the membrane of Escherichia coli, an endogenously expressed His-tagged Im7 protein was constructed to detect any translocation product containing the DNase domain traversed the inner membrane into cytoplasm of the E. coli cells. As a result, a final processed DNase domain of ColE7 was identified in the intracellular space of the cells treated with Col-Im complex. In the presence of periplasmic extracts, in vitro processing of DNase domain of ColE7 was also observed. These results suggest that the processing of ColE7 has occurred for translocation of the DNase-type colicin across the membrane and the process is probably taking place in the periplasmic space of the membrane.

Low tibial osteotomy for moderate ankle arthritis

Low tibial osteotomy is one of the significant advances of ankle reconstruction techniques that has been made recently in an effort to halt arthritis in its early stages and leave fusion as the last, not the only, alternative treatment of ankle arthritis. From 1989 to 1995, we performed 18 low tibial osteotomies which included 6 cases of post-traumatic arthritis and 12 cases of degenerative arthritis. The ages of the 7 male and 11 female patients ranged from 18 to 78 years with an average of 41.9 years. The follow-up period lasted a mean of 47.7 months, ranging from 25 to 82 months. The average functional score changed from 49.6 pre-operatively to 88.5 at the last follow up, and showed yearly improvement. Complications included one case of late infection and two cases of implant failure, none of which led to nonunion. The indication for low tibial osteotomy is the intermediate stage of moderate ankle arthritis with a medial joint lesion and intact lateral facet. Using pressure redistribution on the joint surface, this procedure is an alternative treatment for ankle arthritis which may save an arthritic ankle from the fate of fusion or at least postpone fusion surgery.

Fast optical recording in dye-doped polymer-dispersed liquid-crystal films

We describe a fast optical recording material based on a dye-doped polymer-dispersed liquid-crystal film. A holographic grating is written in this film with a single Q -switched Nd:YAG laser pulse that has a duration of ~6 ns . Such a grating is due to the reorientation effect of the liquid-crystal molecules through interaction with the photoinduced adsorption of the doped azo dyes. Experimental results indicate that the grating thus formed is permanent but electrically switchable.

The first total synthesis of (+/-)-eremopetasidione

[figure: see text] The total synthesis of racemic eremopetasidione, a norsesquiterpenoid, has been achieved in nine steps and 30% overall yield starting from creosol (5). Diels-Alder reaction of masked o-benzoquinone 6 and ethyl vinyl ketone and Cope rearrangement of 2-silyloxy-1,5-dienone 3 are the key steps.

Highly functionalized Bicyclo[2.2.2]octenone-fused [60]fullerenes from masked o-benzoquinones and C(60)

[reaction: see text] The Diels-Alder reactions of masked o-benzoquinones (MOBs) with [60]fullerene, affording novel and highly functionalized bicyclo[2.2. 2]octenone-fused [60]fullerene derivatives, are described.

Landmarks in burn prevention

The objective of this paper is to highlight landmarks in burn prevention. Novel strategies in the areas of law and regulation, environmental and consumer product design, and educational programs are identified and discussed. Notwithstanding marked reductions in burn morbidity and mortality, especially in economically developed countries, burn injuries remain an important public health concern throughout the world. More, and more effective, burn prevention programs coupled with renewed efforts to reduce the social and environmental correlates of burn injuries (poverty, overcrowding, family stress, and educational deficits) are needed to further reduce burn incidence and its long-term sequelae.

One-pot stereoselective synthesis of tricyclic bislactones from 2-pyrones and 2-methoxyfuran

[reaction: see text] A one-pot synthesis of the title compounds via highly chemo-, regio-, and stereoselective Diels-Alder reactions of 2-pyrones with 2-methoxyfuran is described.