Efficient cross-protection against serotype 4/8a fowl adenoviruses (FAdVs): recombinant FAdV-4 with FAdV-8a Fiber

IMPORTANCE

Epidemiological data reveal that FAdV-4 and FAdV-8a are the dominant serotypes of FAdVs in the poultry industry in China. Although three commercial inactivated vaccines against FAdV-4 have been licensed in China, the bivalent vaccine against both FAdV-4 and FAdV-8a is not available. Here, we used CRISPR-Cas9 and Cre-LoxP system to generate a recombinant virus FAdV4-F/8a-rF2 expressing the Fiber of FAdV-8a. Notably, FAdV4-F/8a-rF2 was highly attenuated and could provide efficient protection against both FAdV-4 and FAdV-8a in the chicken infection model, highlighting the applaudable application of FAdV4-F/8a-rF2 as a novel live-attenuated bivalent vaccine against the diseases caused by the infection of FAdV-4 and FAdV-8a.

Identification of key residues of B cell epitopes in hemagglutinin of H6 influenza A virus

IMPORTANCE

Since the escape immunity of influenza A viruses (IAVs) is mainly caused by the continuous antigenic variations in HA, the identification of key antigenic epitopes is crucial for better understanding of the escape immunity and vaccine development for IAVs. The antigenic sites of several HA subtypes, including H1, H3, H5, and H9, have been well characterized, whereas those of H6 subtype are poorly understood. Here, we mapped nine key residues of antigenic epitopes in H6 through escape mutants using a panel of MAbs. Moreover, MAbs 4C2 and 6E3, targeting 140 and 89 residues, respectively, could protect mice against lethal challenge of MA E-Teal/417. These key residues of antigenic epitopes identified here provide the molecular targets for further elucidating the antigenic evolution of H6 and better preparing the vaccine against H6 IAV.

Clinical Outcomes of Sidewall/Parametrial Simultaneous Integrated Boost for Patients with Cervical Cancer

PURPOSE/OBJECTIVE(S)

In the treatment of cervical cancer, simultaneous integrated boost (SIB) is a common technique to deliver increased dose to gross disease in the para-aortic and pelvic nodal basins. However, SIB to the pelvic sidewall/parametria is not well characterized in the literature. We hypothesized that sidewall simultaneous integrated boost (SIB) in the treatment of cervical cancer is associated with acceptable levels of toxicity.

MATERIALS/METHODS

From 1/2009-12/2018, patients who received concurrent chemoradiation with external beam radiation therapy, utilizing a sidewall SIB technique, followed by low dose rate or high dose rate brachytherapy treatment were retrospectively identified. Sidewall SIB was defined as treatment at 2.1-2.4Gy/fraction to the parametria-usually performed for those with disease width >4cm at time of treatment start. Acute and late toxicity grading was defined by the Common Terminology Criteria for Adverse Events Version 5.0. Overall survival (OS), local control, progression-free survival (PFS), and toxicity were analyzed utilizing the Kaplan Meier method. Potential associations between cumulative D2cc for bladder and rectum and time to toxicity were investigated using Cox regression.

RESULTS

Fifty-six patients with IB2-IVB cervical cancer treated with sidewall SIB were identified, with a median follow up of 7.0 years (95% CI: 6.3, 8.3). Patients had a median age of 43 years (range: 26-68); 2 (3.6%) had FIGO stage I, 7 (12.5%) stage II, 46 (82.1%) stage III, and 1 (1.8%) stage IV disease. A majority had squamous cell histology (83.9%). Nearly all patients (96.4%) received concurrent cisplatin chemotherapy. Rates of acute grade ≥3 gastrointestinal (GI), genitourinary (GU), vaginal, and hematologic toxicity were 1.8%, 1.8%, 0%, and 15.9% respectively. Rates of late grade ≥3 GI, GU, and vaginal toxicity were 11.3%, 18.5%, and 11.1% respectively. OS and local control rates at five years were 0.61 (95% CI: 0.46, 0.73) and 0.95 (95% CI: 0.84, 0.98), respectively. Median PFS was 7.8 years (95% CI: 2.4, Not reached). Cumulative D2cc bladder was not significantly associated with time to Grade 2 or greater (HR 1.04, p = 0.33) or Grade 3 or greater (HR 1.02; p = 0.64) GU toxicity. Cumulative D2cc rectum was not significantly associated with time to Grade 2 or greater (HR 1.06, p = 0.06) or Grade 3 or greater (HR 1.08; p = 0.09) GI toxicity.

CONCLUSION

Sidewall SIB is a feasible technique for dose escalation in the treatment of cervical cancer with rates of acute and late toxicity consistent with other reports.

Intracranial Control with Combined Dual Immune-Checkpoint Blockade and SRS for Melanoma and NSCLC Brain Metastases

PURPOSE/OBJECTIVE(S)

It is unknown whether the use of dual immune-checkpoint inhibition (D-ICI) combined with stereotactic radiosurgery (SRS) affects local control of brain metastases (BMs). We sought to characterize the efficacy of SRS and D-ICI in patients with BMs in a large, single-institution cohort.

MATERIALS/METHODS

Patients with melanoma and non-small cell lung cancer (NSCLC) BMs treated with SRS from January 1, 2016 to August 1, 2022 were evaluated. Patients were stratified by treatment with D-ICI versus single ICI (S-ICI). Concurrent ICI was defined as ICI given within four weeks of SRS. Local recurrence (LR), intracranial progression (IP), and overall survival (OS) were estimated using competing risk and Kaplan-Meier analyses. IP included both local and distant intracranial recurrence.

RESULTS

One thousand seven hundred four SRS-treated BMs from 288 patients met inclusion criteria. 55% of patients were symptomatic from their BMs at presentation. Median age, KPS, number of lesions, and SRS courses were 64 (Q1Q3:56-70.5), 90 (80-90), 2 (1-4), and 1 (1-2), respectively. One hundred twenty-eight (44%) melanoma and 160 (56%) NSCLC patients were included. 82 (28.5%), 129 (44.8%), and 77 (26.7%) patients were treated with D-ICI, S-ICI, or SRS alone. Median SRS dose, fractions, and PTV were 20 (Q1Q3:20-25), 1 (1-5), and 0.3cc3 (0.1-1.2). The median follow-up was 14.3 months. One hundred twenty-seven (7.45%) BMs recurred post-SRS and the median time to LR was 4.8 months (Q1Q3:3.0-9.2). On competing risk analysis, LR was significantly reduced with D-ICI (HR: 0.452, p = 0.0024), but not with S-ICI (HR: 0.693, p = 0.0596) compared to SRS alone. The 1-year LR was 3.77% (95% CI = 2.19-6.00), 6.8% (5.19-8.70), and 8.96% (6.48-11.93) with D-ICI, S-ICI, and SRS alone. The median time to IP was 4.1 months (Q1Q3 = 2.9-9.5). On competing risk analysis, IP was significantly reduced with D-ICI (HR = 0.638, p = 0.031), but not with S-ICI (HR = 0.756, p = 0.106) compared to SRS alone. 1-year IP was 40.05% (95% CI = 29.14-50.70), 51.86% (42.78-60.19), and 58.49% (46.30-68.84) with D-ICI, S-ICI, and SRS alone. Concurrent delivery of D-ICI and SRS significantly reduced IP (HR = 0.463, p = 0.0071), whereas other combinations of timing and ICI did not reach significance. Median OS was 11.9 months after SRS. On Kaplan Meier analysis, OS was significantly improved with D-ICI (HR = 0.616, 95% CI = 0.412-0.923, p = 0.019), but not with S-ICI (HR = 0.877, 95% CI = 0.633-1.217, p = 0.433) compared to SRS alone. Hospitalizations (p = 0.021) and immune-related adverse events (irAEs) (p<0.001) were increased with D-ICI. Any grade radiation necrosis (RN) was also increased with D-ICI (p = 0.013), but neurologic adverse events were comparable across cohorts (p = 0.572).

CONCLUSION

D-ICI combined with SRS was associated with improved local control, intracranial control, and overall survival compared to SRS alone, whereas S-ICI was not associated with an improvement in these outcomes. However, D-ICI was also associated with increased risks of irAEs and RN.

Identification of novel B cell epitopes in Fiber-2 protein of duck adenovirus 3 and their application

Duck adenovirus 3 (DAdV-3), a newly emerged duck adenovirus, has resulted in significant economic losses to the duck industry across China since 2014. However, little is known about the B cell epitopes in major antigen of DAdV-3 and the serological approach for detection of DAdV-3 is not available. In this study, four monoclonal antibodies (mAbs) specific to Fiber-2 protein of DAdV-3 were first generated and designated as 2G10, 3D9, 5E6, and 6B12. Indirect immunofluorescence assay (IFA) showed that all of the mAbs reacted with the Fiber-2. Moreover, mAbs 2G10, 5E6, and 6B12 demonstrated good activity with Fiber-2 in Western blot. Notably, the Fiber-2 could be immunoprecipitated efficiently by mAb 3D9. Epitope mapping revealed that mAbs 2G10, 3D9, 5E6, and 6B12 recognized 397-429aa, 463-481aa, 67-99aa, and 1-66aa of Fiber-2, respectively. Besides, a novel sandwich ELISA for efficient detection of DAdV-3 was developed based on mAb 3D9 and horseradish peroxidase (HRP) conjugated mAb 3D9. The sandwich ELISA only reacted with DAdV-3 but not with other duck-associated viruses. The limit of detection of the ELISA was 6.25 × 10³ TCID₅₀/mL. Overall, the mAbs generated laid the foundation for elucidating the critical role of Fiber-2 in mediating infection and pathogenesis, and the sandwich ELISA approach established here provided efficient and rapid serological diagnostic tool for DAdV-3.

An efficient double-fluorescence approach for generating fiber-2-edited recombinant serotype 4 fowl adenovirus expressing foreign gene

Recently, the infection of serotype 4 fowl adenovirus (FAdV-4) in chicken flocks has become endemic in China, which greatly threatens the sustainable development of poultry industry. The development of recombinant FAdV-4 expressing foreign genes is an efficient strategy for controlling both FAdV-4 and other important poultry pathogens. Previous reverse genetic technique for generating the recombinant fowl adenovirus is generally inefficient. In this study, a recombinant FAdV-4 expressing enhanced green fluorescence protein (EGFP), FA4-EGFP, was used as a template virus and directly edited fiber-2 gene to develop an efficient double-fluorescence approach to generate recombinant FAdV-4 through CRISPR/Cas9 and Cre-Loxp system. Moreover, using this strategy, a recombinant virus FAdV4-HA(H9) stably expressing the HA gene of H9N2 influenza virus was generated. Chicken infection study revealed that the recombinant virus FAdV4-HA(H9) was attenuated, and could induce haemagglutination inhibition (HI) titer against H9N2 influenza virus at early time points and inhibit the viral replication in oropharynx. All these demonstrate that the novel strategy for constructing recombinant FAdV-4 expressing foreign genes developed here paves the way for rapidly developing attenuated FAdV-4-based recombinant vaccines for fighting the diseases caused by both FAdV-4 and other pathogens.

A novel recombinant serotype 4 fowl adenovirus expressing fiber-2 protein of duck adenovirus 3

Recently, the highly pathogenic serotype 4 fowl adenovirus (FAdV-4) and duck adenovirus 3 (DAdV-3) were outbroken and widespread, causing substantial economic losses to the duck industry. Therefore, there is an urgent need to generate a recombinant genetic engineering vaccine candidate against both FAdV-4 and DAdV-3. In this study, a novel recombinant FAdV-4 expressing the Fiber-2 protein of DAdV-3, designated as rFAdV-4-Fiber-2/DAdV-3, was generated based on CRISPR/Cas9 and Cre-LoxP systems. Indirect immunofluorescence assay (IFA) and western blot (WB) showed that the Fiber-2 protein of DAdV-3 in rFAdV-4-Fiber-2/DAdV-3 was expressed successfully. Moreover, the growth curve revealed that rFAdV-4-Fiber-2/DAdV-3 replicated efficiently in LMH cells and even showed a stronger replication ability compared to the wild type FAdV-4. The generation of the recombinant rFAdV-4-Fiber-2/DAdV-3 provides a potential vaccine candidate against both FAdV-4 and DAdV-3.

A novel mAb broadly neutralizes SARS-CoV-2 VOCs in vitro and in vivo, including the Omicron variants

Novel immune escape variants have emerged as SARS-CoV-2 continues to spread worldwide. Many of the variants cause breakthrough infections in vaccinated populations, posing great challenges to current antiviral strategies targeting the immunodominance of the receptor-binding domain within the spike protein. Here, we found that a novel broadly neutralizing monoclonal antibody (mAb), G5, provided efficient protection against SARS-CoV-2 variants of concern (VOCs) in vitro and in vivo. A single dose of mAb G5 could significantly inhibit the viral burden in mice challenged with the mouse-adapted SARS-CoV-2 or SARS-CoV-2 Omicron BA.1 variant, as well as the body weight loss and cytokine release induced by mouse-adapted SARS-CoV-2. The refined epitope recognized by mAb G5 was identified as ₁₁₄₈ FKEELDKYF₁₁₅₆ in the stem helix of subunit S2. In addition, a human-mouse chimeric mAb was generated based on the VH and VL genes of mAb G5. Our study provides a broad antibody drug candidate against SARS-CoV-2 VOCs and reveals a novel target for developing pan-SARS-CoV-2 vaccines. This article is protected by copyright. All rights reserved.

HISMD: A Novel Immune Subtyping System for HNSCC

Immune subtyping is an important way to reveal immune heterogeneity, which may contribute to the diversity of the progression and treatment in head and neck squamous cell carcinoma (HNSCC). However, reported immune subtypes mainly focus on levels of immune infiltration and are mostly based on a mono-omics profile. This study aimed to identify a comprehensive immune subtype for HNSCC via multi-omics clustering and build a novel subtype prediction system for clinical application. Data were obtained from The Cancer Genome Atlas database and our independent multicenter cohort. Multi-omics clustering was performed to identify 3 clusters of 499 patients in The Cancer Genome Atlas based on immune-related gene expression and somatic mutations. The immune characteristics and biological features of the obtained clusters were revealed by bioinformatics, and 3 immune subtypes were identified: 1) adaptive immune activation subtype predominantly enriched in T cells, 2) innate immune activation subtype predominantly enriched in macrophages, and 3) immune desert subtype. Subsequently, the clinical implications of each subtype were analyzed per clinical epidemiology. We found that adaptive immune activation showed better survival outcomes and had a similar response to chemotherapy with innate immune activation, whereas immune desert might be relatively resistant to chemotherapy. Moreover, a subtype prediction system was developed by deep learning with whole slide images and named HISMD: HNSCC Immune Subtypes via Multi-omics and Deep Learning. We endowed HISMD with interpretability through image-based key feature extraction. The clinical implications, biological significances, and predictive stability of HISMD were successfully verified by using our independent multicenter cohort data set. In summary, this study revealed the immune heterogeneity of HNSCC and obtained a novel, highly accurate, and interpretable immune subtyping prediction system. For clinical implementation in the future, additional validation and utility studies are warranted.

A peptide-based ELISA for detection of antibodies against novel goose astrovirus type 1

Goose gout disease is a high morbidity and mortality disease caused by novel serotype 1 goose astrovirus (GAstV-1), which has resulted in huge economic loss to the goose industry of China. However, few diagnostic methods have been developed for serological surveillance of GAstV-1. In our previous study, several novel B cell epitopes were identified in the ORF2 protein of GAstV-1. In this study, one novel peptide of 627-646 aa in the ORF2 recognized by monoclonal antibody (mAb) 6C6 was used as an antigen to develop an efficient peptide-based ELISA (pELISA) for detection of antibodies against GAstV-1. Specificity analysis showed that the pELISA only reacted with sera against GAstV-1, but not with sera against other pathogens tested. The sensitivity of the pELISA in detecting positive sera was higher than that of the IFA (Indirect immunofluorescence assay). The coefficients of variation (CV) of the intra-assay and inter-assay were both < 10%, indicating that the reproducibility of pELISA was good. For detection of clinical samples, the pELISA had 87.5% concordance with the IFA. Our data demonstrate that the pELISA generated here provides an accurate, rapid, and economical method for the detection antibodies against GAstV-1 for serological surveillance.

Fiber-1 of serotype 4 fowl adenovirus mediates superinfection resistance against serotype 8b fowl adenovirus

In recent years, hepatitis-hydropericardium syndrome (HHS) and inclusion body hepatitis (IBH) caused by serotype 4 fowl adenovirus (FAdV-4) and serotype 8b fowl adenovirus (FAdV-8b), respectively, are widely prevalent in China, causing huge economic losses to the poultry industry. Numerous studies have revealed the mechanism of the infection and pathogenesis of FAdV-4. However, little is known about the mechanism of infection with FAdV-8b. Among the major structural proteins of fowl adenoviruses, fiber is characterized by the ability to recognize and bind to cellular receptors to mediate the infection of host cells. In this study, through superinfection resistance analysis and an interfering assay, we found that Fiber-1 of FAdV-4, rather than hexon, penton, and fiber of FAdV-8b, conferred efficient superinfection resistance against the infection FAdV-8b in LMH cells. Moreover, truncation analysis depicted that the shaft and knob domains of FAdV-4 Fiber-1 were responsible for the inhibition. However, knockout of the coxsackie and adenovirus receptor (CAR) in LMH cells inhibited the replication of FAdV-8b only at early time points, indicating that CAR might not be the key cell receptor for FAdV-8b. Overall, our findings give novel insights into the infection mechanism of FAdV-8b and provide a new target for the prevention and control of both FAdV-4 and FAdV-8b.

Mouse adaptation of H6 avian influenza viruses and their molecular characteristics

H6 avian influenza viruses (AIVs) not only continue to circulate in both domestic poultry and wild waterfowl, but also have occasionally caused spillovers infections in pigs and humans, posing a potential threat to public health. However, the molecular mechanism of H6 AIV adaptation to mammals remains largely unknown. In this study, two mouse-adapted (MA) H6 AIV strains, named as MA E-Teal/417 and MA GWF-Goose/740, were generated through blind passages in BALB/c mice. The two MA H6 strains replicated more efficiently and showed higher virulence than the corresponding wild type (WT) H6 strains in mice. Genome sequencing revealed that MA E-Teal/417 and MA GWF-Goose/740 carried six amino acid mutations (PB2-T224A/E627K, HA-G124R, NA-F167L/Y356H and M1-M92R), and four amino acid mutations (PB1-K577E, PA-T97I/D514E and HA-T276K), respectively, when compared to the corresponding WT virus. Receptor binding assay showed MA E-Teal/417 had stronger binding activity to α-2,3 SA than WT E-Teal/417. Moreover, the polymerase activity analysis found the RNP polymerase activity of both MA H6 viruses was significantly higher than that of the corresponding WT virus in 293T cells. All these demonstrate that H6 AIV can acquire limit amino acid substitutions to adapt to mammals and increase virulence, highlighting the significance of monitoring such mutations of H6 AIV in the field for alarming the potential of its cross-transmission and pathogenesis in mammals.

Research Note: A novel peptide-based ELISA for efficient detection of antibody against chicken infectious anemia virus

Chicken infectious anemia virus (CIAV) is the pathogen of chicken infectious anemia. Currently, due to the lack of effective diagnostics technology and prevention approach, CIAV has spread globally and caused huge economic losses to poultry industry. In this study, a novel peptide-based ELISA (pELISA) for efficient detection of antibody against CIAV was developed. The peptide (25CRLRRRYKFRHRRRQRYRRRAF45) used in pELISA was highly conserved in VP1 protein of different CIAV isolates. The specificity and reproducibility showed that the pELISA only reacted with sera against CIAV, not with sera against other pathogens tested, and the CV of the intra-/inter-assay of the pELISA was 6.8 to 9.22%. Moreover, the comparison assay using 56 clinical samples showed that the positive rate of the pELISA and the commercial ELISA kit (IDEXX) was 85.7 and 80.4%, respectively. The pELISA generated here provides a rapid and efficient serological detection method for diagnosis of CIAV infection and evaluation of the efficacy of CIAV vaccination.

Phylogeography and Biological Characterizations of H12 Influenza A Viruses

Influenza A virus (IAV) is widespread in wild bird reservoirs. Sixteen hemagglutinin subtypes are associated with wild waterfowl hosts; some subtypes are isolated infrequently, one of which is H12 IAV. In this study, we detected three H12 IAVs from Anascrecca and Anas formosa in Poyang Lake, China, in 2018, one of which was isolated. Phylogenetic analysis revealed that the genome sequences of the three H12 viruses belonged to the Eurasian lineage, except for PA genes and one NP gene, which belonged to the North American lineage. The growth kinetics showed that the H12 isolate grew better in A549 than MDCK cells. Moreover, although the H12 isolate cannot efficiently replicate in BALB/c mice, it can bind to both α-2,6 sialic acid (SA) and α-2,SA-linked receptors. In addition, we examined the phylodynamics of H12 viruses by Bayesian phylogeographic analysis. The results show that two major transmission routes of H12 IAVs were from Asia to Oceania and from Europe to South America, and Anas and Arenaria genera were the major hosts of the viral transmission. Our findings help us better understand the evolution of H12 IAV and highlight the need for the continued surveillance of IAVs circulating in wild birds.

Novel monoclonal antibodies against Fiber-1 of duck adenovirus 3 and their B cell epitopes

Recently, the outbreak of the infection of Duck adenovirus 3 (DAdV-3) characterized by swelling and hemorrhagic liver and kidney has caused huge economic losses to duck industry since 2014 in China. To date, the B cell epitopes in the Fiber-1 protein and the underlying infection mechanism of DAdV-3 have not been investigated. In this study, the recombinant Fiber-1 protein was first expressed in E. coli and six novel monoclonal antibodies (mAbs) against Fiber-1 were generated, designated as 1D8, 1E6, 3G6, 4G1, 4G2, and 6F10, respectively. Moreover, mAbs 3G6 and 6F10 could efficiently immunoprecipitate the Fiber-1 in LMH cells infected with DAdV-3 or transfected with pcDNA3.1-Fiber-1. Notably, mAbs 3G6 and 4G2 also showed certain neutralizing activity against DAdV-3 infection in vitro. Epitopes mapping revealed that the B cell epitope recognized by 6F10, 3G6, 4G1, 1D8, 4G2, and 1E6 was located in 34-66aa, 67-99aa, 64-296aa, 297-329aa, 330-362aa, and 363-395aa, respectively. Sequence alignments further found that the six epitopes recognized by these mAbs were highly conserved among different DAdV-3 isolates. The generated mAbs specific to Fiber-1 and their defined epitopes provide powerful tools for establishing rapid and efficient diagnostics for the detection of DAdV-3 and pave the way for further studying on the critical role of Fiber-1 in mediating the infection of DAdV-3.

An Efficient and Rapid Assay for Detecting Neutralizing Antibodies Against Serotype 4 Fowl Adenovirus

Currently, the outbreak of serotype 4 fowl adenovirus (FAdV-4) has spread worldwide and caused tremendous economic loss to the poultry industry. Although inactivated vaccines have been licensed against FAdV-4 in China, a rapid and efficient serological method for measuring the titer of neutralizing antibodies (NAbs) specific for FAdV-4 post-infection or vaccination is rarely reported. Classical virus neutralization test (VNT) is superior in sensitivity and specificity for detecting NAbs but is either time-consuming or laborious. In this study, a recombinant virus FA4-EGFP expressing EGFP-fiber-2 fusion protein, rather than wild type (WT) FAdV-4 was used to develop a novel VNT for detecting FAdV-4 NAbs. Specificity analysis showed that the approach only reacted with the sera against FAdV-4, not with the sera against other avian pathogens tested. The novel VNT was effective in the detection of NAbs against FAdV-4 in sera from both experimentally infected and clinically vaccinated chickens, and had good linear correlation with the classical VNT. Moreover, the novel VNT not only significantly simplifies the procedure for detection of NAbs, but also shortens the timeline to 24 h in comparison with the classical VNT with 3-4 d. All these data demonstrate that the FA4-EGFP based VNT developed here provides an efficient diagnostic method for monitoring the immunological state of the vaccination or diagnosing the clinical infection of FAdV-4 in a quick and funding-saving manner.

FAdV-4 without Fiber-2 Is a Highly Attenuated and Protective Vaccine Candidate

Hepatitis-hydropericardium syndrome (HHS) caused by the highly pathogenic fowl adenovirus serotype 4 (FAdV-4) has resulted in huge economic losses to the poultry industry globally. The fiber-2 gene, as a major virulence determiner, is also an important vaccine target against FAdV-4. In this study, we used a CRISPR/Cas9-based homology-dependent recombinant technique to replace the fiber-2 gene with egfp and generate a novel recombinant virus, designated FAdV4-EGFP-rF2. Although FAdV4-EGFP-rF2 showed low replication ability compared to the wild-type FAdV-4 in LMH cells, FAdV4-EGFP-rF2 could effectively replicate in LMH-F2 cells with the expression of Fiber-2. Moreover, FAdV4-EGFP-rF2 was not only highly attenuated in chickens, but also could provide efficient protection against a lethal challenge of FAdV-4. Moreover, FAdV4-EGFP-rF2 without fiber-2 could induce neutralizing antibodies at the same level as FA4-EGFP with fiber-2. These results clearly demonstrate that although fiber-2 affects the viral replication and pathogenesis of FAdV-4, it is not necessary for virus replication and induction of neutralizing antibodies; these findings provide novel insights into the roles of fiber-2 and highlight fiber-2 as an insertion site for generating live-attenuated FAdV-4 vaccines against FAdV-4 and other pathogens. IMPORTANCE Among all serotypes of fowl adenovirus, serotypes FAdV-1, FAdV-4, and FAdV-10 are unique members with two fiber genes (fiber-1 and fiber-2). Recent studies reveal that Fiber-1, not Fiber-2, directly triggers viral infection of FAdV-4, whereas Fiber-2, but not Fiber-1, has been identified as the major virulence determiner and an efficient protective immunogen for subunit vaccines. Here, we replaced fiber-2 with egfp to generate a novel recombinant virus, designated FAdV4-EGFP-rF2. In vitro and in vivo studies on FAdV4-EGFP-rF2 revealed that fiber-2 was not necessary for either virus replication or efficient protection for FAdV-4; these results not only provide a novel live-attenuated vaccine candidate against HHS, but also give new ideas for generating a FAdV-4 based vaccine vector against other pathogens.

A Novel Recombinant FAdV-4 Virus with Fiber of FAdV-8b Provides Efficient Protection against Both FAdV-4 and FAdV-8b

Since 2015, the outbreaks of hydropericardium-hepatitis syndrome (HHS) and inclusion body hepatitis (IBH) caused by the highly pathogenic serotype 4 fowl adenovirus (FAdV-4) and serotype 8 fowl adenovirus (FAdV-8), respectively, have caused huge economic losses to the poultry industry. Although several vaccines have been developed to control HHS or IBH, a recombinant genetic engineering vaccine against both FAdV-4 and FAdV-8 has not been reported. In this study, recombinant FAdV-4 expressing the fiber of FAdV-8b, designated as FA4-F8b, expressing fiber of FAdV-8b was generated by the CRISPR-Cas9 and homologous recombinant techniques. Infection studies in vitro and in vivo revealed that the FA4-F8b replicated efficiently in LMH cells and was also highly pathogenic to 2-week-old SPF chickens. Moreover, the inoculation of inactivated the FA4-F8b in chickens could not only induce highly neutralizing antibodies, but also provide efficient protection against both FAdV-4 and FAdV-8b. All these demonstrate that the inactivated recombinant FA4-F8b generated here can act as a vaccine candidate to control HHS and IBH, and FAdV-4 can be an efficient vaccine vector to deliver foreign antigens.

Isolation and Molecular Characteristics of a Novel Recombinant Avian Orthoreovirus From Chickens in China

In recent years, the emergence of avian orthoreovirus (ARV) has caused significant losses to the poultry industry worldwide. In this study, a novel ARV isolate, designated as AHZJ19, was isolated and identified from domestic chicken with viral arthritis syndrome in China. AHZJ19 can cause typical syncytial cytopathic effect in the chicken hepatocellular carcinoma cell line, LMH. High-throughput sequencing using Illumina technology revealed that the genome size of AHZJ19 is about 23,230 bp, which codes 12 major proteins. Phylogenetic tree analysis found that AHZJ19 was possibly originated from a recombination among Hungarian strains, North American strains, and Chinese strains based on the sequences of the 12 proteins. Notably, the σC protein of AHZJ19 shared only about 50% homology with that of the vaccine strains S1133 and 1733, which also significantly differed from other reported Chinese ARV strains. The isolation and molecular characteristics of AHZJ19 provided novel insights into the molecular epidemiology of ARV and laid the foundation for developing efficient strategies for control of ARV in China.

A Novel Fiber-1-Edited and Highly Attenuated Recombinant Serotype 4 Fowl Adenovirus Confers Efficient Protection Against Lethal Challenge

Currently, a fatal disease of hepatitis-hydropericardium syndrome (HHS) caused by serotype 4 fowl adenovirus (FAdV-4) has spread worldwide and resulted in tremendous economic losses to the poultry industry. Various vaccines against FAdV-4 were developed to control the disease; however, few live-attenuated vaccines were available. In this study, we targeted the N-terminal of fiber-1 and rescued a recombinant virus FAdV4-RFP_F1 expressing the fusion protein of RFP and Fiber-1 based on the CRISPR/Cas9 technique. In vitro studies showed that FAdV4-RFP_F1 replicated slower than the wild type FAdV-4, but the peak viral titer of FAdV4-RFP_F1 could still reach 10^7.0 TCID₅₀/ml with high stability in LMH cells. Animal studies found that FAdV4-RFP_F1 not only was highly attenuated to the 2-week-old SPF chickens, but could also provide efficient protection against lethal challenge of FAdV-4. All these demonstrate that the recombinant virus FAdV4-RFP_F1 could be as an efficient live-attenuated vaccine candidate for FAdV-4, and the N-terminal of fiber-1 could be as a potential insertion site for expressing foreign genes to develop FAdV-4-based vaccine.

Aetiology of tinea capitis in China: A multicentre prospective study

BACKGROUND

Tinea capitis is still common in developing countries, such as China. Its pathogen spectrum varies across regions and changes over time.

OBJECTIVES

This study aimed to clarify the current epidemiological characteristics and pathogen spectrum of tinea capitis in China.

METHODS

A multicentre, prospective descriptive study involving 29 tertiary hospitals in China was conducted. From August 2019 to July 2020, 611 patients with tinea capitis were enrolled. Data concerning demography, risk factors and fungal tests were collected. The pathogens were further identified by morphology or molecular sequencing when necessary in the central laboratory.

RESULTS

Among all enrolled patients, 74.1% of the cases were 2- to 8-year-olds. The children with tinea capitis were mainly boys (56.2%) and more likely to have an animal contact history (57.4% vs. 35.3%, P = 0.012) and zoophilic dermatophyte infection (73.5%). The adults were mainly females (83.3%) and more likely to have anthropophilic agent infection (53.5%). The most common pathogen was zoophilic Microsporum canis (354, 65.2%), followed by anthropophilic Trichophyton violaceum (74, 13.6%). In contrast to the eastern, western and northeastern regions where zoophilic M. canis predominated, anthropophilic T. violaceum predominated in central China (69.2%, P < 0.0001), where the patients had the most tinea at other sites (20.3%) and dermatophytosis contact (25.9%) with the least animal contact (38.8%). Microsporum ferrugineum was the most common anthropophilic agent in the western area, especially in Xinjiang Province.

CONCLUSIONS

Boys aged approximately 5 years were mainly affected. Dermatologists are advised to pay more attention to the different transmission routes and pathogen spectra in different age groups from different regions.

A Cross-Reactive Monoclonal Antibody Against Neuraminidases of Both H9N2 and H3N2 Influenza Viruses Shows Protection in Mice Challenging Models

Neuraminidases (NAs) of H9N2 avian influenza virus (AIV) and H3N2 human seasonal influenza virus (HSIV) share similar antigenic structures. However, there are few reports on epitopes shared by these two NAs. We previously reported a monoclonal antibody (mAb) 1G8 against the NA of H9N2 AIV with neuraminidase inhibition (NI) ability. In this study, 1G8 was shown to cross-react with and inhibit the NA of H3N2 HSIV. In a passive transfer experiment, 1G8 provided protection to mice challenged with rescued H1N2 viruses carrying H9N2 NA or H3N2 NA. Mutation at amino acid position 199 was also selected and proved to be crucial for H3N2 HSIV to escape from mAb 1G8. Moreover, we found that residue 199 contributed to inducing broad protective antibodies without the influence of the N-linked glycosylation at amino acid position 200 in NAs. Residues as residue 199, which are not shielded by glycosylation modification, would form ideal epitopes for developing universal vaccine and protective antibodies.

Characterization of Subtype H6 Avian Influenza A Viruses Isolated From Wild Birds in Poyang Lake, China

Subtype H6 avian influenza A viruses (IAVs) are enzootic and genetically diverse in both domestic poultry and wild waterfowl and may cause spillovers in both pigs and humans. Thus, it is important to understand the genetic diversity of H6 IAVs in birds and their zoonotic potential. Compared with that in domestic poultry, the genetic diversity of H6 viruses in wild birds in China has not been well-understood. In this study, five H6 viruses were isolated from wild birds in Poyang Lake, China, and genetic analyses showed that these isolates are clustered into four genotypes associated with reassortments among avian IAVs from domestic poultry and wild birds in China and those from Eurasia and North America and that these viruses exhibited distinct phenotypes in growth kinetics analyses with avian and mammalian cells lines and in mouse challenge experiments. Of interest is that two H6 isolates from the Eurasian teal replicated effectively in the mouse lung without prior adaptation, whereas the other three did not. Our study suggested that there are variations in the mammalian viral replication efficiency phenotypic among genetically diverse H6 IAVs in wild birds and that both intra- and inter-continental movements of IAVs through wild bird migration may facilitate the emergence of novel H6 IAV reassortants with the potential for replicating in mammals, including humans. Continued surveillance to monitor the diversity of H6 IAVs in wild birds is necessary to increase our understanding of the natural history of IAVs.

[Effect of splenectomy on the risk of hepatocellular carcinoma development among patients with liver cirrhosis and portal hypertension: a multi-institutional cohort study]

Objective: To identify whether splenectomy for treatment of hypersplenism has any impact on development of hepatocellular carcinoma(HCC) among patients with liver cirrhosis and hepatitis. Methods: Patients who underwent splenectomy for hypersplenism secondary to liver cirrhosis and portal hypertension between January 2008 and December 2012 were included from seven hospitals in China, whereas patients receiving medication treatments for liver cirrhosis and portal hypertension (non-splenectomy) at the same time period among the seven hospitals were included as control groups. In the splenectomy group, all the patients received open or laparoscopic splenectomy with or without pericardial devascularization. In contrast, patients in the control group were treated conservatively for liver cirrhosis and portal hypertension with medicines (non-splenectomy) with no invasive treatments, such as transjugular intrahepatic portosystemic shunt, splenectomy or liver transplantation before HCC development. All the patients were routinely screened for HCC development with abdominal ultrasound, liver function and alpha-fetoprotein every 3 to 6 months. To minimize the selection bias, propensity score matching (PSM) was used to match the baseline data of patients among splenectomy versus non-splenectomy groups. The Kaplan-Meier method was used to calculate the overall survival and cumulative incidence of HCC development, and the Log-rank test was used to compare the survival or disease rates between the two groups. Univariate and Cox proportional hazard regression models were used to analyze the potential risk factors associated with development of HCC. Results: A total of 871 patients with liver cirrhosis and hypertension were included synchronously from 7 tertiary hospitals. Among them, 407 patients had a history of splenectomy for hypersplenism (splenectomy group), whereas 464 patients who received medical treatment but not splenectomy (non-splenectomy group). After PSM,233 pairs of patients were matched in adjusted cohorts. The cumulative incidence of HCC diagnosis at 1,3,5 and 7 years were 1%,6%,7% and 15% in the splenectomy group, which was significantly lower than 1%,6%,15% and 23% in the non-splenectomy group (HR=0.53,95%CI:0.31 to 0.91,P=0.028). On multivariable analysis, splenectomy was independently associated with decreased risk of HCC development (HR=0.55,95%CI:0.32 to 0.95,P=0.031). The cumulative survival rates of all the patients at 1,3,5,and 7 years were 100%,97%,91%,86% in the splenectomy group,which was similar with that of 100%,97%,92%,84% in the non-splenectomy group (P=0.899). In total,49 patients (12.0%) among splenectomy group and 75 patients (16.2%) in non-splenectomy group developed HCC during the study period, respectively. Compared to patients in non-splenectomy group, patients who developed HCC after splenectomy were unlikely to receive curative resection for HCC (12.2% vs. 33.3%,χ²=7.029, P=0.008). Conclusion: Splenectomy for treatment of hypersplenism may decrease the risk of HCC development among patients with liver cirrhosis and portal hypertension.

Identification of key residues involved in the neuraminidase antigenic variation of H9N2 influenza virus

Influenza A H9N2 virus causes economic loss to the poultry industry and has likely contributed to the genesis of H5N1 and H7N9 viruses. The neuraminidase (NA) of H9N2 virus, like haemagglutinin, is under antibody selective pressure and may undergo antigenic change; however, its antigenic structure remains to be elucidated. In this study, we used monoclonal antibodies (mAbs) to probe the H9N2 viral NA residues that are key for antibody binding/inhibition. These mAbs fell into three groups based on their binding/inhibition of the NA of H9N2 viruses isolated during 1999–2019: group I only bounded the NA of the early 2000 H9N2 viruses but possessed no neutralizing ability, group II bounded and inhibited the NA of H9N2 viruses isolated before 2012, and group III reacted with most or all tested H9N2 viruses. We showed that NA residue 356 is key for the recognition by group I mAbs, residues 344, 368, 369, and 400 are key for the binding/inhibition of NA by group II antibodies, whereas residues 248, 253, and the 125/296 combination are key for neutralizing antibodies in group III. Our findings highlighted NA antigenic change of the circulating H9N2 viruses, and provided data for a more complete picture of the antigenic structure of H9N2 viral NA.

Development of colloidal gold-based test strip for rapid detection of serotype 4 fowl adenovirus

The outbreaks of hepatitis-hydropericardium syndrome (HPS) caused by serotype 4 fowl adenovirus (FAdV-4) have spread from broilers to laying hens, breeders, geese and Cherry Valley duck, resulting in high economic losses to the poultry industry globally. In this study, a rapid colloidal gold test strip for detection of FAdV-4 was developed by using two monoclonal antibodies (mAbs) against the Fiber-2 of FAdV-4. Specificity analysis revealed that the test strip only reacted with FAdV-4, but not with other pathogens including different serotypes of fowl adenovirus and other avian pathogens tested. The limit of the detection (LOD) of the strip could reach as low as 0.1 μg/0.1 mL of GST-Fiber-2 protein and 1 × 10⁵ TCID₅₀/0.1 mL of FAdV-4, respectively. Moreover, the test strip could be efficiently applied in detecting tissue samples from diseased chickens with HPS. Comparison analysis further revealed that the test strip showed good compatibility with PCR assay for detection of virus isolates and clinical samples. In conclusion, our test strip provides an efficient on-site diagnostic method in a quick and convenient manner for detection of FAdV-4, especially in resource-limited areas.

An efficient peptide-based ELISA for differentiating fowl adenovirus 4-infected chickens from vaccinated chickens

Fowl adenovirus serotype 4 (FAdV4), the causative agent of hepatitis-hydropericardium syndrome (HPS), has caused major economic losses to the poultry industry worldwide. Although inactivated vaccines have been deployed widely against FAdV4, a DIVA (differentiating infected from vaccinated animals) test specific for FAdV4 has not been available. We synthesized an immunogenic peptide, corresponding to regions 66-88 aa of the 22K nonstructural protein of FAdV4, and used the peptide as coating antigen to develop an indirect ELISA for a DIVA test specific to FAdV4. Specificity analysis showed that the ELISA only reacted with sera against FAdV4, and not with sera against other pathogens tested. Moreover, the ELISA could effectively differentiate FAdV4-infected chickens from vaccinated chickens. In a test of sera from experimentally infected chickens, the ELISA had 95% and 85% concordance with an indirect immunofluorescence assay (indirect IFA) and a commercial ELISA, respectively, and the concordance was 80.5% between the ELISA and the indirect IFA in detecting clinical infection samples. Our peptide-based ELISA provides an efficient DIVA test for FAdV4 in clinical samples.

124 Perceived Quality of End-Of-Life Communication Provided by Healthcare Professionals Among Frail Older Chinese Patients

Introduction

Better communications among the patient, their family, and healthcare providers can enable a shared understanding on patient’s end-of-life (EOL) care preferences. Discussion about death-related issue however has been thought to be taboo among Chinese people. This study aims to explore perceived quality of EOL communication provided by healthcare professionals (HCPs) among frail older Chinese patients.

Method

Frail older patients were recruited from a medical ward of a public hospital for a randomized controlled trial of the effectiveness of a nurse-led advance care planning. Participants completed a baseline questionnaire including the 7-item Quality of Communication (QOC) Questionnaire which measures perceived quality of EOL communication provided by HCPs (0 “The worst or none happened” to 10 “The best”). Bivariate analyses examined associated factors of QOC.

Results

Between December 2018 and January 2020, 105 participants were recruited and have completed the QOC. Their mean age was 80 years old (SD = 7.1), and 74% (n = 78) reported had received some formal education. A total of 95 participants (91%) responded “0” to all the 7 items in QOC (poor QOC group). For individual QOC item, all participants scored “0” in 4 items, 99 scored “0” in Item 1 “Talking about details if you got sicker”, 104 scored “0” in Item 2 “Talking about how long you might have to live”, and 101 scored “0” in Item 7 “Respecting your spiritual or religious beliefs”. Participants with “0” score in QOC reported a significant lower mean level in certainty regarding decision-making in EOL preferences (1.2 ± 1.6 vs. 2.3 ± 1.8, p = 0.039).

Conclusion

Occurrence of talking about EOL care with frail older Chinese patients by HCPs was rare, and the quality of EOL communication associated with decision-making certainty regarding EOL preferences. Training of initiation of EOL discussions and improve communication skills for HCPs is essential. Funding: RGC, HKSAR, China (PolyU14162617H).

A novel fiber-2-edited live attenuated vaccine candidate against the highly pathogenic serotype 4 fowl adenovirus

Recently, the outbreaks of hydropericardium-hepatitis syndrome (HHS) caused by the highly pathogenic fowl adenovirus serotype 4 (FAdV-4) have resulted in huge economic losses to the poultry industry globally. Although several inactivated or subunit vaccines have been developed against FAdV-4, live-attenuated vaccines for FAdV-4 are rarely reported. In this study, a recombinant virus FA4-EGFP expressing EGFP-Fiber-2 fusion protein was generated by the CRISPR/Cas9 technique. Although FA4-EGFP shows slightly lower replication ability than the wild type (WT) FAdV-4, FA4-EGFP was significantly attenuated in vivo compared with the WT FAdV-4. Chickens infected with FA4-EGFP did not show any clinical signs, and all survived to 14 day post-infection (dpi), whereas those infected with FAdV-4 showed severe clinical signs with HHS and all died at 4 dpi. Besides, the inoculation of FA4-EGFP in chickens provided efficient protection against lethal challenge with FAdV-4. Compared with an inactivated vaccine, FA4-EGFP induced neutralizing antibodies with higher titers earlier. All these data not only provide a live-attenuated vaccine candidate against the highly pathogenic FAdV-4 but also give a potential insertion site for developing FAdV-4-based vaccine vectors for delivering foreign antigens.

Domain in Fiber-2 interacted with KPNA3/4 significantly affects the replication and pathogenicity of the highly pathogenic FAdV-4

The outbreaks of hepatitis-hydropericardium syndrome (HPS) caused by the highly pathogenic serotype 4 fowl adenovirus (FAdV-4) have caused a huge economic loss to the poultry industry globally since 2013. Although the Fiber-2 has been identified as a key virulent related factor for FAdV-4, little is known about its molecular basis. In this study, we identified the efficient interaction of the Fiber-2 with the karyopherin alpha 3/4 (KPNA3/4) protein via its N-terminus of 1–40aa. The analysis of the overexpression and knockout of KPNA3/4 showed that KPNA3/4 could efficiently assist the replication of FAdV-4. Moreover, a fiber-2-edited virus FAV-4_Del with a deletion of 7–40aa in Fiber-2 was rescued through the CRISPR-Cas9 technique. In comparison with the wild type FAdV-4, FAV-4_Del was highly attenuated in vitro and in vivo. Notably, the inoculation of FAV-4_Del in chickens could provide full protection against the lethal challenge with the wild type FAdV-4. All these findings not only give novel insights into the molecular basis for the pathogenesis of Fiber-2 but also provide efficient targets for developing antiviral strategies and live-attenuated vaccine candidates against the highly pathogenic FAdV-4.

A Peptide-Based Enzyme-Linked Immunosorbent Assay for Detecting Antibodies Against Avian Infectious Bronchitis Virus

Infectious bronchitis virus (IBV) causes substantial loss to the poultry industry despite extensive vaccination. Assessing the antibody response is important for the development and evaluation of effective vaccines. We have developed an enzyme-linked immunosorbent assay (ELISA) for the detection of IBV-specific antibodies, using a synthetic peptide based on a conserved sequence in the IBV spike protein. This peptide-based ELISA (pELISA) specifically detects antibodies to different genotypes of IBV but not antibodies against other common chicken viruses. This assay could detect IBV-specific antibody response on as early as day 7 postinfection. In the testing with field serum samples collected from chickens administered with IBV vaccines, the sensitivity, specificity, and accuracy of pELISA were 98.30, 94.12, and 98.8%, respectively, relative to indirect immunofluorescence assay. Our data demonstrate that the pELISA is of value for the detection of IBV antibody and the evaluation of IBV vaccines.

Generation of a recombinant chickenized monoclonal antibody against the neuraminidase of H9N2 avian influenza virus

We previously reported a monoclonal antibody (mAb), 1G8, against the neuraminidase (NA) of H9N2 avian influenza virus (AIV) with significant NA inhibitory activity. To generate a recombinant chickenized mAb (RCmAb) against the NA of H9N2 AIV for passive immunization in poultry, the gene of the fragment of antigen binding (Fab) of mAb 1G8 was cloned and fused with the fragment crystallizable (Fc) gene of chicken IgY. The RCmAb 1G8 was expressed in COS-1 cells and could be detected in cell culture supernatant. The results of NA inhibitory activity tests of the RCmAb 1G8 in an enzyme-linked lectin assay (ELLA) and a microneutralization (MN) assay showed that the RCmAb 1G8 maintained significant NA inhibitory activity and neutralizing ability. This is the first chickenized antibody against AIV, which would be a good candidate for passive immunization in poultry.

[Analysis of treatment response and prognostic factors of T-LBL patients treated with pediatric-like ALL therapy following HSCT]

目的

探讨经急性淋巴细胞白血病（ALL）儿童方案治疗达到完全缓解（CR）和部分缓解（PR）的T淋巴母细胞淋巴瘤（T-LBL）患者应用造血干细胞移植巩固治疗的疗效及预后因素。

方法

收集2013年1月至2017年1月于唐都医院血液病中心接受治疗的T-LBL患者的临床资料，将达到CR或PR的患者纳入研究，进行回顾性分析。

结果

①48例患者接受了ALL儿童方案治疗，经2个疗程的诱导化疗后39例达CR，9例达PR。其中接受自体造血干细胞移植（auto-HSCT）者14例，接受异基因造血干细胞移植（allo-HSCT）者7例，21例患者移植后造血功能均顺利重建。②中位随访时间31（9～16）个月。3年总生存（OS）率为61.0%（95% CI 53.7%～68.3%），3年无进展生存（PFS）率为54.8%（95% CI 47.1%～62.2%）。③移植组和未移植组3年OS率分别为84.7%和42.8%（P＝0.006），两组3年PFS率分别为75.4%和38.9%（P＝0.004）。④auto-HSCT组与allo-HSCT组患者的OS率、PFS率差异均无统计学意义（P值分别为0.320、0.597）。⑤骨髓侵犯、未接受造血干细胞移植是影响患者长期预后的独立危险因素［ HR＝5.804（95% CI 1.140～29.549），P＝0.034；HR＝5.871（95% CI 1.711～20.140），P＝0.005］。

结论

ALL儿童方案化疗序贯造血干细胞移植治疗T-LBL疗效确切，安全性好。auto-HSCT与allo-HSCT患者的OS率及PFS率差异均无统计学意义。骨髓侵犯、未接受造血干细胞移植是影响T-LBL患者长期预后的独立危险因素。

[Surveillance of Oncomelania hupensis distribution and water levels in Gaoyou sections of the eastern route project of the South-to-North Water Diversion Project following operation of the project]

OBJECTIVE

To understand the distribution of Oncomelania hupensis snails and changes of water levels in Gaoyou sections of the Li Canal following the operation of the eastern route project of the South-to-North Water Diversion Project.

METHODS

The Oncomelania snails were monitored in the river banks and water bodies of Gaoyou sections of the Li Canal by means of systematic sampling combined with environmental sampling as well as collection of the floaters from 2014 to 2019, and the water levels were collected in Gaoyou sections of the Li Canal at the typical hydrological year before the operation of the eastern route project of the South-to-North Water Diversion Project and during the period between 2016 and 2019.

RESULTS

A total area of 235.42 hm² were investigated and a total of 75.8 kg floaters were collected in Gaoyou sections of the Li Canal from 2014 to 2019; however, no snails were found. The water level in Gaoyou sections of the Li Canal was predominantly high in the flood season and low in the dry season before the operation of the eastern route project of the South-to-North Water Diversion Project, and the water level was elevated in the dry season and relatively low in the flood season after the operation of the project.

CONCLUSIONS

Following the operation of the eastern route project of the South-to-North Water Diversion Project, the original river bank that is characterized by "land in winter and water in summer" has changed in Gaoyou sections of the Li Canal, which is not favorable for snail breeding.

An efficient fiber-based ELISA for detection of antibody against fowl adenovirus serotypes 7 and 8

An outbreak of inclusion body hepatitis caused by fowl adenovirus serotype 8 (FAdV-8) has caused significant economic losses in the poultry industry worldwide. However, a rapid serology test kit specific to FAdV-8 is not available to date. We developed a fiber-based ELISA using the purified GST-fiber of FAdV-8 as coating antigen to measure antibodies against FAdV-8. Specificity analysis showed that our ELISA could react with sera against FAdV-7, -8a, and -8b, but not with sera against the other pathogens tested. Moreover, detection of positive sera with our ELISA had 83% and 94% agreement with an indirect immunofluorescence assay (IFA) and a commercial ELISA from BioChek, respectively. Our ELISA was also effective in the detection of antibodies against FAdV-8 in sera from both experimentally infected and clinically vaccinated chickens. Our FAdV-8 fiber-based ELISA can be a valuable tool to specifically and sensitively detect antibodies against FAdV-7 and/or -8 in infected or vaccinated chickens.

Retirement planning: the perceptions of pre-retirement nurses within different hospitals in China

AIM

This study explored the perceptions of senior Chinese nurses working in different hospital types, about retirement planning; and compared the results from two hospitals.

BACKGROUND

A recent review indicates that nurses with inadequate retirement planning could be faced with a retirement crisis. In China, hospitals are classified into different levels, and salaries, job satisfaction and the turnover of nurses varies among these levels. These factors may also influence nurses' perceptions of retirement planning.

METHODS

In a descriptive, qualitative design, 27 semi-structured individual interviews were conducted with nurses who were between 50 and 60 years old and recruited from two hospitals in China from April to September 2018. The interviews were transcribed and analysed thematically.

FINDINGS

Four main themes emerged from the interviews, namely, the understanding of pre-retirement nurses of retirement planning, the attitudes of pre-retirement nurses towards retirement planning, factors influencing nurses' retirement planning and the retirement planning activity of nurses. Most nurses participating in this study did not know much about retirement planning, but they all agreed on its importance. We identified the influencing factors of retirement planning and several differences regarding the perceptions of nurses about retirement planning in different hospitals.

CONCLUSION

In this cohort of nurses, planning for a good retirement was thought to be important; however, their readiness for retirement and the influences around planning for retirement were varied in type and scope.

IMPLICATIONS FOR POLICY

Governments and employing hospitals should develop reasonable measures and policies to support nurses in their understanding of the benefits of retirement planning and help them to prepare for retirement. Information about retirement planning should be made available and options for planning explained. Any systematic hurdles to retirement planning should be mitigated or eliminated.

Maternally-Derived Antibodies Protect against Challenge with Highly Pathogenic Avian Influenza Virus of the H7N3 Subtype

Vaccination of hens against influenza leads to the transfer of protective maternally-derived antibodies (MDA) to hatchlings. However, little is known about the transfer of H7N3 vaccine-induced MDA. Here, we evaluated transfer, duration, and protective effect of MDA in chickens against H7N3 HPAIV. To generate chickens with MDA (MDA (+)), 15-week-old White Leghorn hens were vaccinated and boosted twice with an inactivated H7N3 low pathogenic avian influenza virus vaccine, adjuvanted with Montanide ISA 71 VG. One week after the final boost, eggs were hatched. Eggs from non-vaccinated hens were hatched for chickens without MDA (MDA (-)). Both MDA (+) and MDA (-) hatchlings were monitored weekly for antibody levels. Anti-HA MDA were detected by hemagglutination inhibition assay mostly until day 7 post-hatch. However, anti-nucleoprotein MDA were still detected three weeks post-hatch. Three weeks post-hatch, chickens were challenged with 106 EID50/bird of Mexican-origin H7N3 HPAIV. Interestingly, while 0% of the MDA (-) chickens survived the challenge, 95% of the MDA (+) chickens survived. Furthermore, virus shedding was significantly reduced by day 5 post-challenge in the MDA (+) group. In conclusion, MDA confers partial protection against mortality upon challenge with H7N3 HPAIV, as far as three weeks post-hatch, even in the absence of detectable anti-HA antibodies, and reduce virus shedding after challenge.

A Single Mutation N166D in Hemagglutinin Affects Antigenicity and Pathogenesis of H9N2 Avian Influenza Virus

Some immune escape mutants of H9N2 virus and the corresponding mutations in hemagglutinin (HA) have been documented, but little is known about the impact of a single mutation on the antigenicity and pathogenesis of H9N2. In this study, seven critical sites in HA associated with the antigenicity were identified and the effects of a HA mutation (N166D) derived from a H9N2 escape mutant (m3F2) were investigated. Although N166D did not significantly affect viral replication in Madin–Darby canine kidney (MDCK) cells and viral shedding in the larynx and cloaca of chicken, N166D attenuated the pathogenesis of the virus in mice. Compared to the rescued RgPR8-H9_166D, RgPR8-H9_166N caused greater body weight loss and higher viral titers in the lungs of the infected mice. Moreover, hemagglutination inhibition (HI) assay for the sera from the chickens infected with wild type H9N2 and mutant m3F2 showed that N166D mutation could result in weak antibody response in chickens. Considering the field strains of H9N2 with N166D mutation are frequently isolated in the countries with H9N2 vaccination, the findings that the single mutation in HA, N166D, affected both the antigenicity and pathogenesis of H9N2 highlight the significance of surveillance on such mutation that may contribute to the failure of H9N2 vaccination in the field.

Two novel monoclonal antibodies against fiber-1 protein of FAdV-4 and their application in detection of FAdV-4/10

BACKGROUND

Recently, serotype 4 fowl adenovirus (FAdV-4) has spread widely and caused huge economic loss to poultry industry. However, little is known about the molecular pathogenesis of FAdV-4. Fiber protein is thought to be vital for its infection and pathogenesis.

RESULTS

Two novel monoclonal antibodies (mAbs) targeting the fiber-1 protein of FAdV-4 were generated, designated as mAb 3B5 and 6H9 respectively. Indirect immunofluorescence assay (IFA) showed that both mAbs only reacted with the FAdV-4 and FAdV-10, not with other serotypes including FAdV-1, FAdV-5, FAdV-6, FAdV-7, FAdV-8 and FAdV-9 tested. Although both mAbs did not recognize the linear epitopes, they could efficiently immunoprecipitate the fiber-1 protein in LMH cells either infected with FAdV-4 or transfected with pcDNA3.1-Fiber-1. Moreover, mAb 3B5 as a capture antibody and HRP-conjugated mAb 6H9 as a detection antibody, a novel sandwich ELISA for efficient detection of FAdV-4 was generated. The limit of detection of the ELISA could reach to 1000 TCID₅₀/ml of FAdV-4 and the ELISA could be efficiently applied to detect FAdV-4 in the clinical samples.

CONCLUSION

The two mAbs specific targeting fiber-1 generated here would pave the way for further studying on the role of fiber-1 in the infection and pathogenesis of FAdV-4, and the established mAb based sandwich ELISA would provide an efficient diagnostics tool for detection of FAdV-4/10.

[Efficacy and safety study of microsurgical varicocelectomy in the treatment of non-obstructive azoospermia with varicocele]

Objective: To discuss the efficacy and safety of subinguinal microsurgical varicocelectomy in the treatment of non-obstructive azoospermia (NOA) with varicocele. Methods: The clinical data of 141 patients with NOA and varicocele who underwent subinguinal microsurgical varicocelectomy from March 2015 to June 2017 in Shanghai General Hospital was collected.One hundred and ten patients suffered from varicocele on the left side, 1 on the right side, and the rest (30 cases) were bilateral varicocele. Grade Ⅰ varicocele were found on 7 sides (the right and left side was count respectively), grade Ⅱ on 121 sides, and grade Ⅲ on 43 sides. Sperm analysis, pregnancy rate and complications were recorded after at least 6 months since operation. Results: Eleven cases were lost during the follow-up. Eighteen of the remaining 130 NOA patients processed successful sperm retrieval in post-operative semen analysis (18/130, 13.8%). Six couples(6/130, 4.6%) succeeded in natural pregnancy. Five couples (5/130, 3.8%)underwent successful pregnancy following with intracytoplasmic sperm injection(ICSI). Twenty-six out of the remaining 112 patients underwent the micro dissection testicular sperm extraction (micro-TESE), and 4 patients got a successful sperm retrieval (4/26, 15.4%). Among them, 2 couples had successful pregnancy with ICSI. Totally 2 cases of postoperative infection of incision were found. Conclusions: Microsurgical varicocelectomy had a beneficial effect on sperm quality of patients suffered from NOA with varicocele to some extent, even leading to unassisted pregnancy or avoiding micro-TESE before ICSI. Microsurgical varicocelectomy could be applied in the treatment of NOA with varicocele.

A novel linear epitope crossing Group 1 and Group 2 influenza A viruses located in the helix A of HA2 derived from H7N9

In this research, four monoclonal antibodies (mAbs) were first generated as an immunogen by using the GST fusion protein that carries the fusion peptide and helix A derived from H7N9 influenza A virus (IAV). These mAbs could react with HA of H7N9, H3N2, and H9N2 with neutralizing activity. A novel linear epitope recognized by these mAbs was identified by peptide-based ELISA, and this epitope was located in TAADYKSTQSAIDQITGKLN at the C terminus of the helix A of H7N9. 3 A11, which is one of the four mAbs, could efficiently recognize the corresponding epitopes derived from H9, H7, H5, H3, and H1. Analysis of sera against the corresponding epitope from different HAs revealed that the C terminus of helix A in H9, H7, and H3 possessed dominant B cell epitopes that cross both Group 1 and Group 2 IAV, whereas the C terminus of helix A in H5 possessed only dominant B cell epitopes that cross subtypes in Group 1 virus. All these results demonstrated that the linear epitope identified in the helix A of H7N9 could be a novel target for developing broad-spectrum influenza diagnostics or vaccine candidates.

Functional Outcome after Treatment of Aggressive Tumours in the Distal Radius: Comparison between Reconstruction using Proximal Fibular Graft and Wrist Fusion

Introduction: Restoration of a functional hand is the ultimate goal following a distal radius tumour resection. The early outcomes of mobile wrist reconstruction are satisfactory; however, long-term results are unpredictable due to late wrist instability and degenerative arthritis. Our aim is to compare mobile wrist reconstruction with wrist fusion (pan-carpal fusion) in our cohort of patients.

Materials and Methods: A retrospective cohort study was performed for functional outcomes of all patients who underwent resection for distal radius tumour and treated with either fusion or reconstruction of the wrist in a single institution from years 2000-2013 with a minimum of three years follow-up.

Results: Eleven patients were included in the study, six of whom had wrist reconstruction with proximal fibula graft and the remaining five wrist fusion, with a mean follow-up of 6.3 years. The mean Musculoskeletal Tumour Society (MSTS) score was 82.78%, ranging from 70% to 93.3%. Average grip strength compared to the normal contralateral hand was 60.0% for total wrist fusion, which was better than wrist reconstruction with 58.07%. There was no difference in the functional outcome between fusion and mobile reconstruction in our study. Osteoarthritis changes and subluxation of the wrist joint were the most common findings in the long-term follow-up for this group.

Conclusion: There was no difference in the functional outcome of the long-term follow-up between the two groups.

Homologous and heterologous protection against influenza B virus following live attenuated influenza virus (LAIV) immunization

Influenza B virus (IBV) is considered a major human pathogen, responsible for seasonal epidemics of acute respiratory illness. Two antigenically distinct IBV hemagglutinin (HA) lineages co-circulate worldwide with limited antigenic cross-reactivity between each other. Licensed seasonal influenza vaccines are available as inactivated, recombinant, or live attenuated influenza virus (LAIV) vaccines. Although LAIV vaccines mimic a natural infection that is thought to provide better cross-protection than inactivated vaccines, the former are not currently recommended by the CDC for use in the US due to the sub-optimal efficacy. In order to improve LAIV vaccines and following the footsteps of similar work performed by our laboratory using influenza A viruses, we sought to develop an IBV LAIV vaccine. Thus, we created an IBV LAIV using a two-strategy combination that incorporates temperature sensitive (ts) mutations and an epitope tag in the PB1 gene segment. Such modifications resulted in a LAIV candidate with ts characteristics in vitro. We assessed vaccine safety following intranasal immunization and found that IBV LAIV displayed an attenuated (att) phenotype in vivo with virus replication restricted to the upper respiratory tract. Immunization experiments further showed that a single dose of IBV LAIV candidate conferred sterilizing immunity against lethal homologous challenge. Single immunization with IBV LAIV also provided complete protection against heterologous challenge as evidenced by reduced weight loss and lung viral titers. The ability of LAIV to induce cross-protective immune responses may have important implications for the development of universal influenza vaccine approaches.

[Premature outflow tract ventricular contraction combined with complete bundle branch block: the characteristic electrocardiographic and ablation target potential features]

Objective: To explore the characteristics of electrocardiogram(ECG) and target potential features of premature ventricular contraction (PVC) in patients with complete left/right bundle branch block (CL/RBBB) and compare with those without CL/RBBB. Methods: A retrospective analysis was done in 8 outflow tract PVC patients with CL/RBBB, who successfully underwent radiofrequency ablation from August 2009 to June 2017. According to the bundle branch block chamber, patients were divided into the complete right bundle branch block (CRBBB) group (n=4) and the complete left bundle branch block (CLBBB) group (n=4). The control group were those who successfully underwent ablation at the same position as the above two groups but without CL/RBBB. The characteristics of ECG and target potential features were compared among groups. Results: One case in the CRBBB group was successfully ablated in the great cardiac vein with precordial R/S>1 transition at V(1) and one case in the CLBBB group was successfully ablated in the right coronary cusp with precordial R/S>1 transition at V(2), while other 6 cases were all with precordial R/S>1 transition at lead V(4). Precordial R/S>1 transition was not later than sinus rhythm (SR) in the CLBBB group. No statistical difference was found in the QRS complex duration between SR and PVC in the CL/RBBB patients [(134.38±23.80)ms vs (156.75±25.93)ms, P>0.05], while statistical difference was shown in the control group [(92.63±5.76)ms vs (140.25±15.97)ms, P<0.05]. Conclusion: Bundle branch block can lead to misjudgment of PVC origin with CL/RBBB during sinus rhythm, thus the origin chamber of the PVC should be determined according to the mapping and ablation result.