Immunogenicity and protection of a variant nanoparticle vaccine that confers broad neutralization against SARS-CoV-2 variants

SARS-CoV-2 variants have emerged with elevated transmission and a higher risk of infection for vaccinated individuals. We demonstrate that a recombinant prefusion-stabilized spike (rS) protein vaccine based on Beta/B.1.351 (rS-Beta) produces a robust anamnestic response in baboons against SARS-CoV-2 variants when given as a booster one year after immunization with NVX-CoV2373. Additionally, rS-Beta is highly immunogenic in mice and produces neutralizing antibodies against WA1/2020, Beta/B.1.351, and Omicron/BA.1. Mice vaccinated with two doses of Novavax prototype NVX-CoV2373 (rS-WU1) or rS-Beta alone, in combination, or heterologous prime-boost, are protected from challenge. Virus titer is undetectable in lungs in all vaccinated mice, and Th1-skewed cellular responses are observed. We tested sera from a panel of variant spike protein vaccines and find broad neutralization and inhibition of spike:ACE2 binding from the rS-Beta and rS-Delta vaccines against a variety of variants including Omicron. This study demonstrates that rS-Beta vaccine alone or in combination with rS-WU1 induces antibody-and cell-mediated responses that are protective against challenge with SARS-CoV-2 variants and offers broader neutralizing capacity than a rS-WU1 prime/boost regimen alone. Together, these nonhuman primate and murine data suggest a Beta variant booster dose could elicit a broad immune response to fight new and future SARS-CoV-2 variants.

[China guideline for the screening, early detection and early treatment of gastric cancer (2022, Beijing)]

Gastric cancer (GC) is a major digestive tract malignancy in China, which seriously threatens the health of Chinese population. A large number of researches have demons-trated that screening, early detection and early treatment are effective in reducing the incidence and mortality of GC. The development of the guideline for GC screening, early detection and early treatment in line with epidemic characteristics of GC in China will greatly promote the homogeneity and standardization, and improve the effect of GC screening. This guideline was commissioned by the Bureau of Disease Control and Prevention of the National Health Commission. The National Cancer Center of China initiated and convened a working group comprising multidisciplinary experts. Following the World Health Organization Handbook for Guideline Development, this guideline combined the most up-to-date evidence of GC screening, China's national conditions, and practical experience in cancer screening. This guideline provided evidence-based recommendations with respect to the screening population, technology and procedure management, aiming to improve the effect of GC screening and provide scientific evidence for the GC prevention and control in China.

[China guideline for the screening, early detection and early treatment of esophageal cancer (2022, Beijing)]

Esophageal cancer (EC) is a major digestive tract malignancy in China, which seriously threatens the health of Chinese population. A large number of researches have demonstrated that screening and early detection are effective in reducing the incidence and mortality of EC. The development of the guideline for EC screening and early detection in line with epidemic characteristics of EC in China will greatly promote the homogeneity and standardization, and improve the effect of EC screening. This guideline was commissioned by the Bureau of Disease Control and Prevention of the National Health Commission. The National Cancer Center of China initiated and convened a working group comprising multidisciplinary experts. Following the World Health Organization Handbook for Guideline Development, this guideline combined the most up-to-date evidence of EC screening, China's national conditions, and practical experience in cancer screening. This guideline provided evidence-based recommendations with respect to the screening population, technology and procedure management, aiming to improve the effect of EC screening and provide scientific evidence for the EC prevention and control in China.

[QUADAS-C-A tool for assessing risk of bias regarding Quality Assessment of Diagnostic Accuracy Studies-Comparative]

This paper introduced the Quality Assessment of Diagnostic Accuracy Studies-Comparative (QUADAS-C), illustrated the comparison with the QUADAS-2, and using QUADAS-C together with QUADAS-2 to present QUADAS-C results through systematic reviews. Like the domain for QUADAS-2, QUADAS-C retained four domains, including patient selection, index test, reference standard, flow, and timing, and comprised additional questions for each QUADAS-2 part. Unlike the QUADAS-2 tool, the starting question of each domain for QUADAS-C was designed to summarize the risk of biased information captured by QUADAS-2. QUADAS-C only dealt with the risk of bias but did not include the part of concerns regarding applicability. The answers to signaling questions for each domain of QUADAS-C would lead to a 'low''high' or 'unclear' risk of biased judgment for the original study.

[Development of a Ranking Tool for Scientificity, Transparency and Applicability of Clinical Practice Guidelines]

Objective: To address the limitations of existing methods and tools for evaluating clinical practice guidelines, we aimed to develop a comprehensive instrument focusing on the three main dimensions of guideline development: scientificity, transparency, applicability. We will use it to rank the guidelines according to the scores. We abbreviated it as STAR, and its reliability, validity and usability were also tested. Methods: A multidisciplinary expert working group was set up, including methodologists, statisticians, journal editors, medical professionals, and others. Scoping review, Delphi methods and hierarchical analysis were used to determine the final checklist of STAR. Results: The new instrument contained 11 domains and 39 items. Intrinsic reliability of each domain was indicated by Cronbach's α coefficient, with a average value of 0.646. The Cohen's kappa coefficients for methodological evaluators and clinical evaluators were 0.783 and 0.618. The overall content validity index was 0.905. The R2 for the criterion validity analysis was 0.76. The average score for usability of the items was 4.6, and the mean time spent to evaluate each guideline was 20 minutes. Conclusion: The instrument has good reliability, validity and evaluating efficiency, and can be used for evaluating and ranking guidelines more comprehensively.

[China guideline for the screening and early detection of prostate cancer (2022, Beijing)]

Prostate cancer (PC) is one of the malignant tumors of the genitourinary system that occurs more often in elderly men. Screening, early diagnosis, and treatment of the PC high risk population are essential to improve the cure rate of PC. The development of the guideline for PC screening and early detection in line with epidemic characteristics of PC in China will greatly promote the homogeneity and quality of PC screening. This guideline was commissioned by the Bureau of Disease Control and Prevention of the National Health Commission. The National Cancer Center of China initiated and convened a working group comprising multidisciplinary experts. This guideline strictly followed the World Health Organization Handbook for Guideline Development and combined the most up-to-date evidence of PC screening, China's national conditions, and practical experience in cancer screening. A total of fifteen detailed evidence-based recommendations were provided with respect to the screening population, technology, procedure management, and quality control in the process of PC screening. This guideline aimed to standardize the practice of PC screening and improve the effectiveness and efficiency of PC prevention and control in China.

A comparison of the reproductive performance in primiparous sows following two timed artificial insemination protocols

Timed artificial insemination (TAI) is an efficient reproductive technology in batch farrowing production that aids management in pig farms. However, the effect of TAI on the reproduction performance is still controversial. This study aimed to evaluate the effects of two TAI protocols on the reproductive performance of primiparous sows. A total of 332 weaned sows were randomly allocated into three treatments. Sows assigned to Control (n = 110) were untreated and inseminated on each day in oestrus after weaning. Sows assigned to eG-TAI (n = 112) received equine chorionic gonadotropin (eCG) 24 h after weaning and gonadotropin-releasing hormone (Gonadorelin: GnRH) at oestrus, and were inseminated at 8 and 32 h later if oestrus at 0800, or 16 and 40 h later if oestrus at 1600. Sows assigned to 2e-TAI (n = 110) received eCG and GnRH 24 h and 96 h after weaning, respectively, and were inseminated 16 and 40 h after GnRH administration. Sows showing oestrus at GnRH administration or 64 h after were inseminated immediately, for a total of three inseminations. Ultrasonographic evaluations were performed to determine the follicular diameter and time of ovulation. Most sows in the 2e-TAI and eG-TAI groups ovulated 0-48 h after the GnRH injection. Our results indicated that oestrus rate within seven days after weaning in the experimental groups was higher, and weaning-to-oestrus interval was shorter than in the control group (99.3 h vs 113.5 h, P < 0.05). The breeding and farrowing rates in the experimental groups were significantly higher than in the control group (P < 0.05), while the numbers of total born, live-born and stillborn were not different among the three groups (Control: 12.7, 11.6 and 1.1; 2e-TAI: 12.4, 11.3 and 1.0; eG-TAI: 12.0, 11.4 and 0.4, respectively). These results indicated that TAI could ensure a high farrowing rate in primiparous sows under batch farrowing management.

Fab and Fc contribute to maximal protection against SARS-CoV-2 following NVX-CoV2373 subunit vaccine with Matrix-M vaccination

Recently approved vaccines have shown remarkable efficacy in limiting SARS-CoV-2-associated disease. However, with the variety of vaccines, immunization strategies, and waning antibody titers, defining the correlates of immunity across a spectrum of antibody titers is urgently required. Thus, we profiled the humoral immune response in a cohort of non-human primates immunized with a recombinant SARS-CoV-2 spike glycoprotein (NVX-CoV2373) at two doses, administered as a single- or two-dose regimen. Both antigen dose and boosting significantly altered neutralization titers and Fc-effector profiles, driving unique vaccine-induced antibody fingerprints. Combined differences in antibody effector functions and neutralization were associated with distinct levels of protection in the upper and lower respiratory tract. Moreover, NVX-CoV2373 elicited antibodies that functionally targeted emerging SARS-CoV-2 variants. Collectively, the data presented here suggest that a single dose may prevent disease via combined Fc/Fab functions but that two doses may be essential to block further transmission of SARS-CoV-2 and emerging variants.

[Analysis of pathogen monitoring results of infectious diarrhea in Beijing Traditional Chinese Medicine Hospital Affiliated to Capital Medical University from 2016 to 2019]

Objective: to analyze the distribution characteristics of major enteropathogens in infectious diarrhea cases attending the intestinal outpatient clinic of Beijing Traditional Chinese medicine hospital, Capital Medical University. Methods: From 2016 to 2019, 588 fecal samples of patients with infectious diarrhea in Beijing Hospital of traditional Chinese Medicine Affiliated to Capital Medical University were collected for microbial isolation, culture, identification and pathogen gene detection. Using VITEK 2 compact full-automatic microbial identification/drug sensitivity analysis system to identify the bacteria isolated from the culture; using serum agglutination test to classify the pure colonies; using multiple fluorescence quantitative PCR amplification technology to detect the gene amplification of the samples. Results: In 2016-2019, the total physical examination rate of pathogen was 39.796%. The top three pathogen were diarrhea Escherichia coli (21.769%, n=128), Salmonella (5.782%, n=34), Vibrio (4.762%, n=28). The difference of positive rates of different pathogens in four years was statistically significant (P=0.021), and the peak of incidence was from July to September. The positive rate of norovirus was 5.612% (n=33), and the highest incidence occurred in May. Conclusion: The pathogen of infectious diarrhea patients in Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University from April to October 2016-2019 is mainly diarrhea Escherichia coli, and the pathogen type of norovirus is GⅡ genome.

[Predictive value of lactate concentration combined with lactate clearance rate in the prognosis of neonatal septic shock]

Objective: To investigate the predictive value of lactate concentration within 1 h after admission combined with lactate clearance rate (LC) at 6 h after fluid resuscitation in prognosis of neonatal septic shock. Methods: In this retrospective study, 58 newborns with septic shock admitted to the Neonatal Intensive Care Unit of Xi'an Children's Hospital,Xi'an Jiao Tong University from June 2016 to March 2020 were enrolled. According to the mortality within 60 days after admission,which was also set as the end point, the patients were divided into death group and survival group. The general demographic data and clinical variables including blood cell counts, procalcitonin, C-reactive protein, D-dimer, serum creatinine, and lactate concentration within 1 h after admission (Lac1) and at 6 h after fluid resuscitation (Lac2) were collected. The differences in the clinical variables between the survival and death group were compared by independent sample t test or Rank-Sum test, and the risk factors of poor prognosis were analyzed by binary Logistic regression. The predictive values of these risk factors were tested by receiver operating characteristic (ROC) curve. Furthermore, the cut-off of the risk factors were used to analyze the accumulative survival rate by Kaplan-Meier curve. Results: A total of 58 neonates were enrolled, among whom 24 survived and 34 died within 60 days after admission. The rate of premature rupture of membranes in the death group was higher than that in the survival group (41% (14/34) vs.13%(3/24), P=0.021). There were also significant differences in infection site, pathogenic characteristics, total fluid volume of resuscitation, vasoactive drug index, rate and complications of mechanical ventilation between the two groups (all P<0.05). The levels of Lac1, Lac2, procalcitonin, D-dimer and serum creatinine in the death group were higher than those in the survival group ((12±6) vs. (7±4) mmol/L, (14±6) vs. (4±2) mmol/L, (59±23) vs.(24±14) ng/L, (24±11) vs.(11±6) mg/L, (167±31) vs.(92±23) μmol/L, t=3.549, 3.112, 3.859, 4.499, 3.288, all P<0.05). While the blood pressure and LC at 6 h after fluid resuscitation were lower than those in the survival group ((41±12) vs. (52±5) mmHg (1 mmHg=0.133 kPa), t =4.230;-16 (-40, 20) % vs. 40 (18, 70) %, Z= 3.558, all P<0.05). Binary Logistic regression analysis showed that LC was negatively associated with the risk of death in neonates with septic shock (odds ratio (OR) and 95% confidence interval (CI): 0.679 (0.662-0.999), P<0.05), while Lac1 was the risk factor and positively associated with the risk of death (OR and 95% CI: 1.203 (0.965-1.500), P<0.05). Furthermore, the predictive values of LC, Lac1 and the combination of these two variables in the prognosis of neonatal septic shock were analyzed by ROC curve analysis, and the area under the curve (AUC) were 0.699, 0.875, 0.965, respectively, with the sensitivity of 83.32%, 89.65% and 94.31%, and the specificity of 72.52%, 77.18% and 88.76%, respectively. According to the cut-off value of Lac1, the newborns with Lac1>4 mmol/L had significantly lower accumulative survival rate than those with Lac1≤4 mmol/L by Kaplan-Meier analysis (21% (8/38) vs. 80% (16/20), χ²=54.520, P<0.05). According to the cut-off value of LC, the newborns with LC ≤ 10% had significantly lower accumulative survival rate than those with LC>10% by Kaplan-Meier analysis (19% (6/32) vs. 69% (18/26), χ²=14.140, P<0.05). Conclusion: The combination of lactate concentration and lactate clearance rate have an optimal predictive value in the prognosis of neonatal septic shock.

[China guideline for the screening and early detection of female breast cancer(2021, Beijing)]

Breast cancer is the commonest malignant tumor among Chinese females, ranking first in terms of incidence of female cancers. Commissioned by the Disease Prevention and Control Bureau of National Health Commission of the People's Republic of China, the National Cancer Center formulated the Guideline for Screening and Early Diagnosis and Treatment of Female Breast Cancer in China according to WHO Handbook for Guideline Development. The methods on Cochrane China were referred to for the formulation of the system evaluation procedures. The GRADE methods for assessment, formulation and evaluation were adopted for the classification of evidence quality and recommendation strength, and the items were reported according to Reporting Items for Practice Guidelines in Healthcare. Based on the results of evaluation, the guideline gives evidence-based recommendations for the appropriate population and technical procedures for breast cancer screening and early diagnosis and treatment after comprehensive consideration of China's national conditions, the advantages and disadvantages of the evidence, the quality of the evidence, the economic cost of screening, the feedback of multidisciplinary clinical research respondents, and in-person expert consensus. It is aimed at regulating the practices of female breast cancer screening and early diagnosis and treatment and enhancing the effectiveness of the prevention and control of female breast cancer in China.

[China guideline for the screening and early detection of lung cancer(2021, Beijing)]

In China, the malignant tumor with the highest incidence and motality is lung cancer (LC). As screening and early detection and treatment are effective in reducing LC mortality, formulating a guideline in line with China's national conditions for the screening and early detection and treatment of LC will greatly promote the homogeneity and accuracy of LC screening, and result in an improvement of the effectiveness of LC screening. Commissioned and directed by the Disease Prevention and Control Bureau of the National Health Commission of the People's Republic of China, the guidline was initiated by the National Cancer Center of China and formulated with joint effort by experts from different disciplines. Following the principles and methods in WHO Handbook for Guideline Development, the guidline integrates the latest development in LC screening and early diagnosis and treatment worldwide while fully considering China's national conditions and practical experience in LC screening. It provides detailed evidence-based recommendations for different aspects of LC screening, such as the targeted population, the technologies and the procedures, to regulate the practices of LC screening and early diagnosis and treatment and enhance the effectiveness of the prevention and control of LC in China.

Collaboration between the Fab and Fc contribute to maximal protection against SARS-CoV-2 following NVX-CoV2373 subunit vaccine with Matrix-M™ vaccination

Recently approved vaccines have already shown remarkable protection in limiting SARS-CoV-2 associated disease. However, immunologic mechanism(s) of protection, as well as how boosting alters immunity to wildtype and newly emerging strains, remain incompletely understood. Here we deeply profiled the humoral immune response in a cohort of non-human primates immunized with a stable recombinant full-length SARS-CoV-2 spike (S) glycoprotein (NVX-CoV2373) at two dose levels, administered as a single or two-dose regimen with a saponin-based adjuvant Matrix-M™. While antigen dose had some effect on Fc-effector profiles, both antigen dose and boosting significantly altered overall titers, neutralization and Fc-effector profiles, driving unique vaccine-induced antibody fingerprints. Combined differences in antibody effector functions and neutralization were strongly associated with distinct levels of protection in the upper and lower respiratory tract, pointing to the presence of combined, but distinct, compartment-specific neutralization and Fc-mechanisms as key determinants of protective immunity against infection. Moreover, NVX-CoV2373 elicited antibodies functionally target emerging SARS-CoV-2 variants, collectively pointing to the critical collaborative role for Fab and Fc in driving maximal protection against SARS-CoV-2. Collectively, the data presented here suggest that a single dose may prevent disease, but that two doses may be essential to block further transmission of SARS-CoV-2 and emerging variants.

Collaboration between the Fab and Fc contribute to maximal protection against SARS-CoV-2 in nonhuman primates following NVX-CoV2373 subunit vaccine with Matrix-M™ vaccination

Recently approved vaccines have already shown remarkable protection in limiting SARS-CoV-2 associated disease. However, immunologic mechanism(s) of protection, as well as how boosting alters immunity to wildtype and newly emerging strains, remain incompletely understood. Here we deeply profiled the humoral immune response in a cohort of non-human primates immunized with a stable recombinant full-length SARS-CoV-2 spike (S) glycoprotein (NVX-CoV2373) at two dose levels, administered as a single or two-dose regimen with a saponin-based adjuvant Matrix-M™. While antigen dose had some effect on Fc-effector profiles, both antigen dose and boosting significantly altered overall titers, neutralization and Fc-effector profiles, driving unique vaccine-induced antibody fingerprints. Combined differences in antibody effector functions and neutralization were strongly associated with distinct levels of protection in the upper and lower respiratory tract, pointing to the presence of combined, but distinct, compartment-specific neutralization and Fc-mechanisms as key determinants of protective immunity against infection. Moreover, NVX-CoV2373 elicited antibodies functionally target emerging SARS-CoV-2 variants, collectively pointing to the critical collaborative role for Fab and Fc in driving maximal protection against SARS-CoV-2. Collectively, the data presented here suggest that a single dose may prevent disease, but that two doses may be essential to block further transmission of SARS-CoV-2 and emerging variants.

HIGHLIGHTS

NVX-CoV2373 subunit vaccine elicits receptor blocking, virus neutralizing antibodies, and Fc-effector functional antibodies.The vaccine protects against respiratory tract infection and virus shedding in non-human primates (NHPs).Both neutralizing and Fc-effector functions contribute to protection, potentially through different mechanisms in the upper and lower respiratory tract.Both macaque and human vaccine-induced antibodies exhibit altered Fc-receptor binding to emerging mutants.

SARS-CoV-2 spike glycoprotein vaccine candidate NVX-CoV2373 immunogenicity in baboons and protection in mice

The COVID-19 pandemic continues to spread throughout the world with an urgent need for a safe and protective vaccine to effectuate herd protection and control the spread of SARS-CoV-2. Here, we report the development of a SARS-CoV-2 subunit vaccine (NVX-CoV2373) from the full-length spike (S) protein that is stable in the prefusion conformation. NVX-CoV2373 S form 27.2-nm nanoparticles that are thermostable and bind with high affinity to the human angiotensin-converting enzyme 2 (hACE2) receptor. In mice, low-dose NVX-CoV2373 with saponin-based Matrix-M adjuvant elicit high titer anti-S IgG that blocks hACE2 receptor binding, neutralize virus, and protects against SARS-CoV-2 challenge with no evidence of vaccine-associated enhanced respiratory disease. NVX-CoV2373 also elicits multifunctional CD4⁺ and CD8⁺ T cells, CD4⁺ follicular helper T cells (Tfh), and antigen-specific germinal center (GC) B cells in the spleen. In baboons, low-dose levels of NVX-CoV2373 with Matrix-M was also highly immunogenic and elicited high titer anti-S antibodies and functional antibodies that block S-protein binding to hACE2 and neutralize virus infection and antigen-specific T cells. These results support the ongoing phase 1/2 clinical evaluation of the safety and immunogenicity of NVX-CoV2373 with Matrix-M (NCT04368988).

SARS-CoV-2 spike glycoprotein vaccine candidate NVX-CoV2373 immunogenicity in baboons and protection in mice

The COVID-19 pandemic continues to spread throughout the world with an urgent need for a safe and protective vaccine to effectuate herd protection and control the spread of SARS-CoV-2. Here, we report the development of a SARS-CoV-2 subunit vaccine (NVX-CoV2373) from the full-length spike (S) protein that is stable in the prefusion conformation. NVX-CoV2373 S form 27.2-nm nanoparticles that are thermostable and bind with high affinity to the human angiotensin-converting enzyme 2 (hACE2) receptor. In mice, low-dose NVX-CoV2373 with saponin-based Matrix-M adjuvant elicit high titer anti-S IgG that blocks hACE2 receptor binding, neutralize virus, and protects against SARS-CoV-2 challenge with no evidence of vaccine-associated enhanced respiratory disease. NVX-CoV2373 also elicits multifunctional CD4⁺ and CD8⁺ T cells, CD4⁺ follicular helper T cells (Tfh), and antigen-specific germinal center (GC) B cells in the spleen. In baboons, low-dose levels of NVX-CoV2373 with Matrix-M was also highly immunogenic and elicited high titer anti-S antibodies and functional antibodies that block S-protein binding to hACE2 and neutralize virus infection and antigen-specific T cells. These results support the ongoing phase 1/2 clinical evaluation of the safety and immunogenicity of NVX-CoV2373 with Matrix-M (NCT04368988).

Structural analysis of full-length SARS-CoV-2 spike protein from an advanced vaccine candidate

Vaccine efforts to combat the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for the current coronavirus disease 2019 (COVID-19) pandemic, are focused on SARS-CoV-2 spike glycoprotein, the primary target for neutralizing antibodies. We performed cryo-election microscopy and site-specific glycan analysis of one of the leading subunit vaccine candidates from Novavax, which is based on a full-length spike protein formulated in polysorbate 80 detergent. Our studies reveal a stable prefusion conformation of the spike immunogen with slight differences in the S1 subunit compared with published spike ectodomain structures. We also observed interactions between the spike trimers, allowing formation of higher-order spike complexes. This study confirms the structural integrity of the full-length spike protein immunogen and provides a basis for interpreting immune responses to this multivalent nanoparticle immunogen.

NVX-CoV2373 vaccine protects cynomolgus macaque upper and lower airways against SARS-CoV-2 challenge

There is an urgent need for a safe and protective vaccine to control the global spread of SARS-CoV-2 and prevent COVID-19. Here, we report the immunogenicity and protective efficacy of a SARS-CoV-2 subunit vaccine (NVX-CoV2373) produced from the full-length SARS-CoV-2 spike (S) glycoprotein stabilized in the prefusion conformation. Cynomolgus macaques (Macaca fascicularis) immunized with NVX-CoV2373 and the saponin-based Matrix-M™ adjuvant induced anti-S antibody that was neutralizing and blocked binding to the human angiotensin-converting enzyme 2 (hACE2) receptor. Following intranasal and intratracheal challenge with SARS-CoV-2, immunized macaques were protected against upper and lower infection and pulmonary disease. These results support ongoing phase 1/2 clinical studies of the safety and immunogenicity of NVX-CoV2327 vaccine (NCT04368988).

NVX-CoV2373 vaccine protects cynomolgus macaque upper and lower airways against SARS-CoV-2 challenge

There is an urgent need for a safe and protective vaccine to control the global spread of SARS-CoV-2 and prevent COVID-19. Here, we report the immunogenicity and protective efficacy of a SARS-CoV-2 subunit vaccine (NVX-CoV2373) produced from the full-length SARS-CoV-2 spike (S) glycoprotein stabilized in the prefusion conformation. Cynomolgus macaques (Macaca fascicularis) immunized with NVX-CoV2373 and the saponin-based Matrix-M™ adjuvant induced anti-S antibody that was neutralizing and blocked binding to the human angiotensin-converting enzyme 2 (hACE2) receptor. Following intranasal and intratracheal challenge with SARS-CoV-2, immunized macaques were protected against upper and lower infection and pulmonary disease. These results support ongoing phase 1/2 clinical studies of the safety and immunogenicity of NVX-CoV2327 vaccine (NCT04368988).

Flexible RSV Prefusogenic Fusion Glycoprotein Exposes Multiple Neutralizing Epitopes that May Collectively Contribute to Protective Immunity

Human respiratory syncytial virus (RSV) is a cause of lower respiratory tract infection in infants, young children, and older adults. There is no licensed vaccine and prophylactic treatment options are limited. The RSV fusion (F) glycoprotein is a target of host immunity and thus a focus for vaccine development. F-trimers are metastable and undergo significant rearrangements from the prefusion to a stable postfusion structure with neutralizing epitopes on intermediate structures. We hypothesize that vaccine strategies that recapitulate the breathable F quaternary structure, and provide accessibility of B-cells to epitopes on intermediate conformations, may collectively contribute to protective immunity, while rigid prefusion F structures restrict access to key protective epitopes. To test this hypothesis, we used the near full-length prefusogenic F as a backbone to construct three prefusion F variants with substitutions in the hydrophobic head cavity: (1) disulfide bond mutant (DS), (2) space filling hydrophobic amino acid substitutions (Cav1), and (3) DS, Cav1 double mutant (DS-Cav1). In this study, we compared the immunogenicity of prefusogenic F to prefusion F variants in two animal models. Native prefusogenic F was significantly more immunogenic, producing high titer antibodies to prefusogenic, prefusion, and postfusion F structures, while animals immunized with DS or DS-Cav1 produced antibodies to prefusion F. Importantly, prefusogenic F elicited antibodies that target neutralizing epitopes including prefusion-specific site zero (Ø) and V and conformation-independent neutralizing sites II and IV. Immunization with DS or DS-Cav1 elicited antibodies primarily to prefusion-specific sites Ø and V with little or no antibodies to other key neutralizing sites. Animals immunized with prefusogenic F also had significantly higher levels of antibodies that cross-neutralized RSV A and B subtypes, while immunization with DS or DS-Cav1 produced antibodies primarily to the A subtype. We conclude that breathable trimeric vaccines that closely mimic the native F-structure, and incorporate strategies for B-cell accessibility to protective epitopes, are important considerations for vaccine design. F structures locked in a single conformation restrict access to neutralizing epitopes that may collectively contribute to destabilizing F-trimers important for broad protection. These results also have implications for vaccine strategies targeting other type 1 integral membrane proteins.

[The current situation of occupational burnout and its influencing factors among orphan child care workers in Nanjing]

Objective: To explore the status of job burnout of nurses for orphans and disabled children in Nanjing and its influencing factors, so as to provide reference for promoting the mental health of nurses for orphans and disabled children. Methods: From February to May, 2017, a cross-sectional survey was conducted among 236 nurses working in social welfare institutions for orphans and disabled children in Nanjing, using Occupational Stress Indicator (OSI) and Maslach Burnout Inventory (MBI) . It investigated the status of job burnout among nurses of orphans and disabled children, logistic regression analysis was used to explore the effect of occupational stress on the incidence of job burnout of nurses for orphans and disabled children. Results: The results showed that the incidence of job burnout was 67.37% (159/236) , the incidence of job burnout was negatively correlated with behavioral characteristics and family support, the incidence of emotional exhaustion was positively correlated with task control and job monotony (P<0.05) , and negatively correlated with role ambiguity and job satisfaction (P<0.05) . The incidence of depersonalization was negatively correlated with job monotony and peer support (P<0.05) . Conclusion: The nurses of orphans and disabled children have serious job burnout. Occupational stress factors, personality characteristics and relieving factors have influence on the incidence of job burnout.

Structural analysis of full-length SARS-CoV-2 spike protein from an advanced vaccine candidate

Vaccine efforts against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for the current COVID-19 pandemic are focused on SARS-CoV-2 spike glycoprotein, the primary target for neutralizing antibodies. Here, we performed cryo-EM and site-specific glycan analysis of one of the leading subunit vaccine candidates from Novavax based on a full-length spike protein formulated in polysorbate 80 (PS 80) detergent. Our studies reveal a stable prefusion conformation of the spike immunogen with slight differences in the S1 subunit compared to published spike ectodomain structures. Interestingly, we also observed novel interactions between the spike trimers allowing formation of higher order spike complexes. This study confirms the structural integrity of the full-length spike protein immunogen and provides a basis for interpreting immune responses to this multivalent nanoparticle immunogen.

[Study on occupational stress response of orphans and disabled children care workers in Nanjing]

Objective: To explore the status quo of occupational stress and its influencing factors of nursing staff for orphaned and disabled children in Nanjing, and to put forward measures for adverse reactions to occupational stress, so as to ensure the psychological health of this occupational population. Methods: From February to May 2017, 236 nursing assistants for orphans and disabled children in Nanjing social welfare home were selected by cluster sampling method. The occupational stress index(occupational stress indictor, OSI) was used to investigate occupational stress response and occupational stress factors. Partial correlation and multiple linear regression were used for statistical analysis. Results: The scores of job satisfaction, mental health and depressive symptoms in occupational stress reaction were (43. 99±6. 83) , (36. 09±4. 59) and (17. 31±2. 44) re- spectively. In terms of job satisfaction, work monotony, logic and compound change were the contributing fac- tors (P<0. 05) , task strategy and task control were negative factors (P<0. 05) ; on mental health, opportunities were raised and participation in decision-making Self-esteem, technology utilization, environmental control, time management, task strategy and support of colleagues as contributing factors (P<0. 05) , ambition and role conflicts as negative factors (P<0. 05) ; on depression, work input, participation Decision-making, promotion opportunities and behavioral characteristics were protective factors (P<0. 05 ) . Conclusion: Occupational stress among caregivers of orphans and disabled children cannot be ignored. Occupational stress reaction is serious. Occupational stress factors should be reduced and individual stress coping ability should be enhanced.

[Analysis of the pregnancy outcomes in pregnant women with COVID-19 in Hubei Province]

Objective: To study the effect of COVID-19 on pregnancy outcomes and neonatal prognosis in Hubei Province. Method: s A retrospective comparison of the pregnancy outcomes was done between 16 women with COVID-19 and 45 women without COVID-19. Also, the results of laboratory tests, imaging examinations, and the 2019 novel coronavirus (2019-nCoV) nucleic acid test were performed in 10 cases of neonatal delivered from women with COVID-19. Result: s (1) Of the 16 pregnant women with COVID-19, 15 cases were ordinary type and 1 case was severe type. No one has progressed to critical pneumonia.The delivery method of the two groups was cesarean section, and the gestational age were (38.7±1.4) and (37.9±1.6) weeks,there was no significant difference between the two groups (P>0.05). Also, there wee no significant differences in the intraoperative blood loss and birth weight of the newborn between the two groups (all P>0.05). (2) Ten cases of neonates delivered from pregnant women with COVID-19 were collected. The 2019-nCoV nucleic acid test were all negative.There were no significant differences in fetal distress, meconium-stained amniotic fluid, preterm birth, and neonatal asphyxia between the two groups (all P>0.05).(3) In the treatment of uterine contraction fatigue, carbetocin or carboprost tromethamine was used more in cesarean section for pregnant women with COVID-19 (1.3±0.6), compared with Non-COVID-19 group (0.5±0.7),the difference was statistically significant (P=0.001). Conclusions: If there is an indication for obstetric surgery or critical illness of COVID-19 in pregnant women, timely termination of pregnancy will not increase the risk of premature birth and asphyxia of the newborn, but it is beneficial to the treatment and rehabilitation of maternal pneumonia. Preventive use of long-acting uterotonic agents could reduce the incidence of postpartum hemorrhage during surgery. 2019-nCoV infection has not been found in neonates delivered from pregnant women with COVID-19.

Influenza Hemagglutinin Nanoparticle Vaccine Elicits Broadly Neutralizing Antibodies against Structurally Distinct Domains of H3N2 HA

Influenza vaccine effectiveness varies annually due to the fast evolving seasonal influenza A(H3N2) strain and egg-derived mutations—both of which can cause a mismatch between the vaccine and circulating strains. To address these limitations, we have developed a hemagglutinin (HA)-based protein-detergent nanoparticle influenza vaccine (NIV) with a saponin-based Matrix-M™ adjuvant. In a phase 1 clinical trial of older adults, the vaccine demonstrated broadly cross-reactive A(H3N2) HA antibody responses. Two broadly neutralizing monoclonal antibodies derived from NIV-immunized mice were characterized by transmission electron microscopy (TEM), antibody competition assays, fluorescence-activated cell sorting (FACS) analysis, and protein–protein docking. These antibodies recognize two conserved regions of the head domain, namely the receptor binding site and the vestigial esterase subdomain, thus demonstrating the potential for an HA subunit vaccine to elicit antibodies targeting structurally and antigenically distinct but conserved sites. Antibody competition studies with sera from the phase 1 trial in older adults confirmed that humans also make antibodies to these two head domains and against the highly conserved stem domain. This data supports the potential of an adjuvanted recombinant HA nanoparticle vaccine to induce broadly protective immunity and improved vaccine efficacy.

Maternal immunization with RSV fusion glycoprotein vaccine and substantial protection of neonatal baboons against respiratory syncytial virus pulmonary challenge

Globally, human respiratory syncytial virus (RSV) is a major cause of severe lower respiratory infection in infants and young children. There are no licensed vaccines despite the high worldwide disease burden. RSV fusion (F) glycoprotein vaccine is the most advanced candidate for maternal immunization. In this report, a baboon maternal immunization model was used to assess the immunogenicity and protection of infants against pulmonary challenge with human RSV/A. Vaccination in the third trimester produced high anti-RSV F IgG titers and virus-neutralizing antibodies. Infants born to immunized females had high levels of serum RSV antibodies that were comparable to maternal levels at birth and persisted for over 50 days with a half-life of 14-24 days. Furthermore, infants from immunized females and challenged with RSV/A were healthy, developed less severe disease, and had only mild pulmonary inflammatory changes whereas infants born to non-vaccinated females developed more severe disease with marked to moderate interstitial pneumonia, pulmonary edema, and bronchiolar obstruction. These results support the further development of the RSV F vaccine for maternal immunization.

Evaluation of transcutaneous immunization as a delivery route for an enterotoxigenic E. coli adhesin-based vaccine with CfaE, the colonization factor antigen 1 (CFA/I) tip adhesin

dscCfaE is a recombinant form of the CFA/I tip adhesin CfaE, expressed by a large proportion of enterotoxigenic E. coli (ETEC). It is highly immunogenic by the intranasal route in mice and Aotus nancymaae, protective against challenge with CFA/I+ ETEC in an A. nancymaae challenge model, and antibodies to dscCfaE passively protect against CFA/I+ ETEC challenge in human volunteers. Here, we show that transcutaneous immunization (TCI) with dscCfaE in mice resulted in strong anti-CfaE IgG serum responses, with a clear dose-response effect. Co-administration with heat-labile enterotoxin (LT) resulted in enhanced immune responses over those elicited by dscCfaE alone and strong anti-LT antibody responses. The highest dose of dscCfaE administered transcutaneously with LT elicited strong HAI titers, a surrogate for the neutralization of intestinal adhesion. Fecal anti-adhesin IgG and IgA antibody responses were also induced. These findings support the feasibility of TCI for the application of an adhesin-toxin based ETEC vaccine.

Influence of miR-520e-mediated MAPK signalling pathway on HBV replication and regulation of hepatocellular carcinoma cells via targeting EphA2

We determined the role of miR-520e in the replication of hepatitis B virus (HBV) and the growth of hepatocellular carcinoma (HCC) cells. MiR-520e and EPH receptor A2 (EphA2) in HBV-positive HCC tissues and cells were detected, and we studied the impact of miR-520e and the EphA2 receptor in cellular and murine HBV replication models. We find that MiR-520e was upregulated and EphA2 was downregulated in HBV-positive HCC tissues and cells. MiR-520e was decreased in Huh7-X and HepG2-X cells in which HBx was stably expressed, but was dose-dependently elevated after interfering with HBx. Additionally, miR-520e mimic and si-EphA2 groups were reduced in association with increases in HBV DNA content, HBsAg and HBeAg levels, cell proliferation and were enhanced in the expressions of EphA2, p-p38MAPK/p38MAPK, phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2)/ERK1/2 and cell apoptosis. Furthermore, si-EphA2 reversed the promotion effect of miR-520e inhibitor on HBV replication and tumour cell growth. Upregulating miR-520e in rAAV8-1.3HBV-infected mouse resulted in reduced EphA2 in liver tissues and HBV DNA content in serum. We find that MiR-520e was decreased in HBV-positive HCC, while overexpression of miR-520e blocked p38MAPK and ERK1/2 signalling pathways by an inhibitory effect on EphA2 and ultimately reduced HBV replication and inhibited tumour cell growth. These data indicate a role for miR-520e in the regulation of HBV replication.

Structure basis of neutralization by a novel site II/IV antibody against respiratory syncytial virus fusion protein

Globally, human respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infections in newborns, young children, and the elderly for which there is no vaccine. The RSV fusion (F) glycoprotein is a major target for vaccine development. Here, we describe a novel monoclonal antibody (designated as R4.C6) that recognizes both pre-fusion and post-fusion RSV F, and binds with nanomole affinity to a unique neutralizing site comprised of antigenic sites II and IV on the globular head. A 3.9 Å-resolution structure of RSV F-R4.C6 Fab complex was obtained by single particle cryo-electron microscopy and 3D reconstruction. The structure unraveled detailed interactions of R4.C6 with antigenic site II on one protomer and site IV on a neighboring protomer of post-fusion RSV F protein. These findings significantly further our understanding of the antigenic complexity of the F protein and provide new insights into RSV vaccine design.

[Quantitative three-dimensional methodology based on intraoral scan to assess the soft tissue contour alterations following single immediate implant and immediate provisionalization in maxillary central incisor: a 1-year prospective study]

Objective: To establish a quantitative three-dimensional method based on intraoral scan and apply it to evaluation of the facial soft tissue contour alterations following single immediate implant and immediate provisionalization (IIPP) in central incisor via intraoral scanning. Methods: This study was a prospective clinical study. The trial was conducted at Department of Implantology, Peking University School and Hospital of Stomatology, from January 2016 to September 2017. Twenty-nine eligible consecutive patients (15 women, 14 men) with a mean age of (34.3±12.0) were included and received immediate replacement of the failure maxillary single central incisor. A screw-retained immediate restoration was delivered for each patient. At 6-month follow-up, impression was taken and a screw-retained permanent restoration was performed for each patient. The anterior maxillary region was scanned by an intraoral scanning system at pre-surgery and 1-year follow-up. The Standard Tessellation Language (STL) files were output to a dedicated software and superimposed. Mid-facial recession and gingival zenith symmetry at 1-year follow-up were measured in the digital models. Three-dimensional configurations of the contour change volume were calculated and reconstructed for visual analysis. Furthermore, the following parameters were used to analyze the reconstructed volume: mean contour change in thickness (△d), mesio-distal width (D(W)), coronal-apical height (D(H)), contour change at 0, 1, 2, 3, 4, 5 mm apical to the free gingival margin on the implant site. Results: Twenty-seven out of twenty-nine enrolled patients were finally available for analysis. At 1-year follow-up, the mid-facial mucosa level at implant site was (0.23±0.39) mm apical to the gingival zenith of the contralateral tooth. In general, a contour collapse was found in every patient. △d, D(W) and D(H) of the collapsed volume were (0.62±0.22), (11.03±1.74) and (6.82±1.52) mm, respectively. Contour change at 0, 1, 2, 3, 4, 5 mm apical to the free gingival margin on the implant site were (0.54±0.48), (0.87±0.62), (1.03±0.46), (0.96±0.52), (0.90±0.52), (0.89±0.57) mm. Conclusions: The described quantitative measurement based on intraoral scan can be an effective method for assessment of soft tissue contour changes. At 1 year following single IIPP treatment in maxillary incisor, free gingival margin is stable, with only mild recession. The mean level of the facial soft tissue contour collapse is 0.62 mm.

[Multimodal analgesic analgesia in patients with obstructive sleep apnea hypopnea syndrome with multiple planar surgery]

Objective:To observe the value of multimodal analgesia in patients with OSAHS undergoing multiplanar surgery.Method: A total number of 90 patients with obstructive sleep apnea hypopnea syndrome with tongue hypertrophy or hyperplasia of the root lymphoid tissue were collected. All patients underwent improved uvulatopharyngeal angioplasty (H-UPPP) and tongue root partial resection, or simultaneous tongue ablation at the same time, and they were randomly divided into two groups,45 patients in each group.In multi-modal analgesic group, the parrixibub sodium 40 mg were given intravenously 0.5 h before surgery, and oxygen budesonide aerosol inhalation therapy was given after surgery.Besides,sodium aescinate 10 mg was given intravenously 24, 48, 72 h after surgery,respectively.The control group did not do the above treatment. Both groups received 40 mg paradoxes sodium hydrostatic Bid for 4 days.To perform VAS on two groups of patients, uvula swelling time and first time to eat were recorded，and the symptoms of postoperative nausea and vomiting were observed.Result: The general conditions of the two groups of patients, including age, sex, body mass index, intraoperative blood loss, and operative time, were not statistically significant(all of the P>0.05). The scores of 24, 48, 72, 96 h VAS in multi-mode analgesic group were lower than those in control group after the operation of multi-mode analgesia, and the difference was statistically significant（P<0.05）.The duration of the swelling time of the uvula in the multi-mode analgesic group was significantly shorter than that in the control group, and the difference was statistically significant (5.44±0.88) d compared with (7.68±0.89) d (t=12.01, P<0.01);(30.1±7.3)h compared with (36.5±7.0) h,(t=4.25, P<0.01). Conclusion: Multi-mode analgesia is effective for OSAHS patients after multi-planar surgery. It effectively reduces postoperative pain, shortened postoperative swelling time, and improves the surgical compliance and safety.

[Analysis of olfactory dysfunction after endoscopic and microscopic endonasal transsphenoidal surgery for pituitary adenoma]

Objective:To analyze the clinical data of patients with olfactory dysfunction after endoscopic or microscopic endonasal transsphenoidal approach,and to screen out the possible related factors,to guide clinical diagnosis and treatment,and to improve the patients' quality of life.Method:In the retrospective study,we analyze patients' data,and follow up them with telephone,records the olfactory levels before and after surgery. In the prospective study,five odors were applied to test the olfactory function before the surgery,then one week,3 weeks and 6 weeks after that. The results were statistically analyzed.Result:In the retrospective study,olfactory dysfunction occurred in 67.74%,47.37%in MTS group and ETS group. The olfactory disorder had no significant difference (P>0.05) among MTS group and ETS group after surgery. And the analysis of factors showed no significant difference. In the prospective study,there is significant difference between the preoperative results and postoperative results about the operative side and nonoperative side in ETS group and MTS group (P<0.05). In all results,there is no significant difference between operative side and nonoperative side in ETS group and MTS group (P>0.05).Conclusion:There is olfactory dysfunction after transsphenoidal surgery to resect pituitary adenomas. To prepare the nasal condition well preoperatively,protect the nasal structure intraoperatively and aplicate appropriate treatment postoperatively may reduce the incidence of olfactory disorder.

Exogenous substances regulate silkworm fat body protein synthesis through MAPK and PI3K/Akt signaling pathways

Insect fat body is an important intermediate metabolic organ that plays an important role in protein metabolism and detoxification. In order to study the effects of TiO₂ NPs and phoxim on fat body protein synthesis through MAPK and PI3K/Akt signaling pathways in silkworms, we determined the effects of TiO₂ NPs and phoxim, alone and in combination, on fat body protein content of silkworms, analyzed the gene expression profile of the fat body, and verified the expression of characteristic genes. We found that TiO₂ NPs and phoxim alone increased the total protein content of the fat body, and up-regulated MAPK and PI3K/Akt signaling pathway genes. TiO₂ NPs up-regulated the expression of two growth and development-related genes-insulin-like peptide and neuropeptide receptor B-by 5.17 and 3.89-fold, respectively. Phoxim up-regulated the expression of detoxification genes-P450, GST, and CarE2. Pretreatment with TiO₂ NPs could reduce phoxim-increased total protein content and up-regulated MAPK and PI3K/Akt signaling pathway genes and detoxification genes; the activities of detoxification enzymes were consistent with the gene expression pattern. Our results showed that MAPK and PI3K/Akt signaling pathways both regulate fat body protein synthesis in silkworms, but the target proteins induced to express were different under different inducing factors. Our finding may provide a reference for investigating the mechanism of protein synthesis regulation through MAPK and PI3K/Akt signaling pathways.

[Effect of Six1,TGF-β,VEGF-C that promoting tumor lymphangiogenesis in human laryngeal carcinoma xenografts in nude mice]

Objective:To research the effect of Six1,TGF-β,VEGF-C that promoting tumor lymphangiogenesis in human laryngeal carcinoma xenografts in nude mice. Method:Technology of RNA interference was used for silencing Six1 and TGF-β genes expression in laryngeal squamous cell, preparation Six1-targeting and TGF-β-targeting siRNA for transfecting into laryngeal squamous cell carcinoma, sieve out positive clone cell and amplify. Preparing bearing cancer mice, the mice were divided into five groups, group A (untransfected),group B(empty vector), group C(Six1-siRNA),group D(TGF-β-siRNA),group E(Six1+TGF-β-siRNA). 6-12mm when the tumor has grown, the mice were sacrificed by cervical. The size of each tumor and metastasis were observed and recorded.The protein expression of Six1,TGF-β and VEGF-C was determined by immunohistochemistry and Western blot.The mRNA of Six1,TGF-β and VEGF-C was determined by RT-PCR. Result:The average tumor volume and the number of metastasis cases in group B have no statistically significant compared with group A. The average tumor volume in group C, group D and group E has no significantly reduced, but there is a clear reduction of the number of metastasis cases compared with group A. The average tumor volume and number of metastasis cases in group E has no significantly reduced compared with group C and group D. Both protein and mRNA expression of Six1, TGF-β and VEGF-C in group B had no significant difference compared with group A. In group C, group D and group E,both protein and mRNA expression of VEGF-C was decreased,difference has statistically significant compared with group A. Both protein and mRNA expression of VEGF-C in group E had no significant difference compared with group C and group D. Conclusion:Both Six1 and TGF-β can mediate tumor lymphangiogenesis and lymph node metastasis by mediate the expression of VEGF-C. Suggest that Six1,TGF-β might be a potential therapeutic target for preventing lymph node metastasis of tumor.

[The efficiency of different biliary cannulation in endoscopic retrograde cholangiopancreatography: a meta-analysis]

Objective: To compare the success rates of wire-guided biliary cannulation (WGC) and conventional cannulation (CC) and their effect on the outcome of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). Methods: All randomized controlled trials (RCTs) were collected by searching CNKI, WanFang Data, CBM, PubMed, Embase and Cochrane Library.The assessment of methodological quality and data extraction of the included studies were performed independently by two reviewers. Meta-analysis was conducted with RevMan 5.2 software. Results: Ten RCTs, with a total of 3 262 patients enrolled, were retrieved.Meta-analysis demonstrated that WGC had a higher success rate(RR=1.04, 95%CI 1.01-1.06, P<0.01)and a lower risk of PEP after cannulation (RR=0.54, 95%CI 0.41-0.71, P<0.01). The main reason for the lower risk of PEP was due to lower proportion of mild PEP patients after WGC(RR=0.52, 95%CI 0.36-0.73, P<0.01), while the incidence of modest and severe PEP was comparable in the two groups(modest group: RR=0.84, 95%CI 0.43-1.64, P=0.61; severe group: RR=0.53, 95%CI 0.22-1.31, P=0.17). Conclusion: WGC may increase the success rate of cannulation and reduce the incidence of PEP because of less complications of mild PEP.

Effects of TiO2 nanoparticles on nutrition metabolism in silkworm fat body

Silkworm (Bombyx mori) is an important economic insect with a fat body that plays a crucial role in the storage and transfer of nutrients. It is also known that TiO₂ nanoparticles (NPs) can improve feed efficiency and promote silk protein synthesis in the silkworm. In this study, we profiled gene expression in the silkworm fat body after TiO₂ NP treatment, validated the major RNA-seq findings, and determined the contents of trehalose and triglyceride, the activity of lipase, and the amount of total proteins. RNA-seq analysis revealed that TiO₂ NP treatment caused significant expression changes in 341 genes (P≤0.01), 138 of which were upregulated while the other 203 were downregulated. The expression levels of two target genes in the insulin signaling pathway and two protein metabolism-related target genes, three lipid metabolism-associated target genes, two carbohydrate metabolism related target genes and expression levels of seven heat shock protein genes were increased, and that of threonine dehydratase gene and fatty acid transport protein gene were decreased. The RNA-seq results of 16 genes were validated by quantitative real-time PCR. The lipase activity, content of trehalose, and amount of total proteins were elevated by 3.86-fold, 1.34-fold, and 1.21-fold, respectively, and the content of triglyceride was decreased by 0.94-fold after TiO₂ NP treatment. These results indicated that TiO₂ NPs activated the insulin signaling pathway, promoted the metabolism of protein, fat, and carbohydrate, and improved nutrition metabolism. Our study provides new support for the understanding of the beneficial effect of TiO₂ NPs on silkworm nutrient metabolism.

Summary: Our study indicates that TiO₂ nanoparticles promote nutrient metabolism in the fat body of silkworms, and provide a reference for studies investigating the biological function of TiO₂ nanoparticles.

Mechanisms of TiO2 NPs-induced phoxim metabolism in silkworm (Bombyx mori) fat body

Silkworm is an important economic insect. Abuse of organophosphorus pesticides in recent years often leads to poisoning of silkworms, which significantly affects sericulture development by reducing silk production. Previous studies have shown that TiO2 NPs can effectively mitigate the damages caused by organophosphorus pesticides in silk glands and nerve tissues. The fat body is an important metabolic detoxification organ of silkworms, but it is unknown whether TiO2 NPs affect pesticide metabolism in fat body. In this study, we characterized the transcription of antioxidant genes and enzyme activity in fat body after TiO2 NPs and phoxim treatments using transcriptome sequencing, real-time PCR, and enzyme activity assay. Transcriptome sequencing detected 10 720, 10 641, 10 403, and 10 489 genes for control group, TiO2 NPs group, phoxim group, and TiO2 NPs+phoxim group, respectively. The TiO2 NPs+phoxim group had 705 genes with significantly differential expression (FDR<0.001), among which the antioxidant genes thioredoxin reductase 1 and glutathione S-transferase omega 3 were significantly upregulated. In phoxim group, the expression levels of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase delta (GSTd), and thioredoxin peroxidase (TPx) were increased by 1.365 -fold, 1.335 -fold, 1.642 -fold, and 1.765 -fold, respectively. The level changes of SOD, CAT, GSTd, and TPx were validated by real time PCR. The contents of reactive oxygen species (ROS), malondialdehyde (MDA), and hydrogen peroxide (H2O2) were increased by 1.598 -fold, 1.946 -fold, and 1.506 -fold, respectively, indicating that TiO2 NPs treatment can relieve phoxim-induced oxidative stress. To clarify the mechanism of TiO2 NPs's effect, the transcription levels of P450 gene family were measured for the TiO2 NPs+phoxim group; the expression levels of CYP4M5, CYP6AB4, CYP6A8, and CYP9G3 were elevated by 2.784 -fold, 3.047 -fold, 2.254 -fold, and 4.253 -fold, respectively, suggesting that high expression of P450 family genes can enhance the metabolism of phoxim in the fat body. The results of this study indicated that TiO2 NPs treatment promoted the transcriptional expression of the P450 family genes to improve the fat body's ability to metabolize phoxim and reduce phoxim-induced oxidative stress. This may be the main mechanism of TiO2 NPs' mitigation of phoxim-induced damages in the fat body.

Effects of mutations on the structure and function of silkworm type 1 acetylcholinesterase

AChE is the target of organophosphate (OP) and carbamate (CB) pesticides, and mutations in the gene can significantly reduce insects' sensitivity to these pesticides. Bombyx mori is highly sensitive to pesticides. To investigate the effects of mutations on AChE1 structure and function, we used a prokaryotic system to express B.mori wild type AChE1 (wAChE1) and mutant AChE1 (mAChE1) in this study. Active AChE1 proteins were obtained after refolding and purification, and wAChE1 and mAChE1 had similar activities. After incubation with 10(-6)M physostigmine and 10(-3)mg/mL phoxim, the remaining enzyme activity of mAChE1 was 4.42% and 8.86% higher than that of wAChE1's, respectively. Three-dimensional analysis of mutation AChE1 (mAChE1) revealed that the Ser and Ala side chains extended toward the central part of S285 with distances of just 2.80Å and 3.68Å, respectively, which changed the spatial structure of the active center and reduced its sensitivity to pesticides. These results indicated that the mutations altered the 3D structure of AChE1, which may affect the binding of physostigmine and phoxim to the serine residue at the active center, leading to reduced sensitivity. Our study helps understand the relationship between AChE1 mutations and pesticide resistance and provides a new direction for the cultivation of new pesticide-resistant varieties of B.mori.

A novel fusion protein containing the receptor binding domains of C. difficile toxin A and toxin B elicits protective immunity against lethal toxin and spore challenge in preclinical efficacy models

Antibodies targeting the Clostridium difficile toxin A and toxin B confer protective immunity to C. difficile associated disease in animal models and provided protection against recurrent C. difficile disease in human subjects. These antibodies are directed against the receptor binding domains (RBD) located in the carboxy-terminal portion of both toxins and inhibit binding of the toxins to their receptors. We have constructed a recombinant fusion protein containing portions of the RBD from both toxin A and toxin B and expressed it in Escherichia coli. The fusion protein induced high levels of serum antibodies to both toxins A and B capable of neutralizing toxin activity both in vitro and in vivo. In a hamster C. difficile infection model, immunization with the fusion protein reduced disease severity and conferred significant protection against a lethal dose of C. difficile spores. Our studies demonstrate the potential of the fusion protein as a vaccine that could provide protection from C. difficile disease in humans.

The effects of laparoscopic vs. open gastric bypass for morbid obesity: a systematic review and meta-analysis of randomized controlled trials

The aim of this meta-analysis was to assess the effects of laparoscopic vs. open gastric bypass for morbid obesity. A systematic review of the literature was undertaken to assess randomized controlled trials on laparoscopic and open gastric bypass for morbid obesity. Six randomized controlled trials involving a total of 422 patients were included. There were 214 patients in the laparoscopic group and 208 patients in the open group separately. Compared with open surgery, laparoscopic surgery for morbid obesity could significantly shorten hospital stays (WMD=-1.11 d, 95% confidence interval [CI][-1.65, -0.56]). However, laparoscopic surgery for morbid obesity showed higher re-operation (RR=4.82, 95% CI [1.29, 17.98]) and longer surgical time (WMD=28.00 min, 95% CI [7.84, 48.16]). There were no statistical differences in complication (RR=0.84, 95% CI [0.64, 1.10]) and weight loss (WMD=1.00 kg m(-2), 95% CI [-0.79, 2.79]). The effects of laparoscopic and open gastric bypass for morbid obesity were basically the same except that laparoscopic had a shorter hospital stay and open surgery had a rate of fewer re-operations and shorter surgical time. Further high-quality, long follow-up period randomized controlled trials should be carried out to provide more reliable evidence.

Capecitabine/oxaliplatin as first-line treatment for metastatic colorectal cancer: a meta-analysis

OBJECTIVE

A meta-analysis of randomized controlled trials (RCT) was carried out to determine the efficacy and safety of capecitabine plus oxaliplatin (CAPOX) or fluorouracil plus oxaliplatin (FUOX) as first-line treatment for metastatic colorectal cancer (MCRC).

METHOD

A literature search was conducted of the Cochrane Controlled Trials Register Databases, Medline, Embase, ISI databases and Chinese Biomedical Literature Database without exclusion of material published in any language. RCTs conducted between 1998 and 2008 of CAPOX compared with FUOX regimens were considered for inclusion. Statistical analyses were carried out using RevMan software.

RESULTS

Ten RCTs were included, involving 3208 patients. The meta-analysis showed that there were no statistically significant differences in tumour response rate (RR, 0.93; 95% CI, 0.87-1.01; P = 0.09), progression-free survival (PFS) (RR, 0.98; 95% CI, 0.94-1.01; P = 0.19), and overall survival (OS) (RR, 1.02; 95% CI, 0.97-1.07; P = 0.47) between CAPOX and FUOX regimen. However, symptoms of thrombocytopenia and hand-foot syndrome (HFS) were increased in the CAPOX regimen (RR, 1.89; 95% CI, 1.33-2.69; P = 0.0004 and RR, 3.40; 95% CI, 2.25-5.15; P < 0.00001 respectively), while neutropenia and leucopenia occurred more frequently in the FUOX regimen (RR, 0.29; 95% CI, 0.15-0.55; P = 0.0002 and RR, 0.41; 95% CI, 0.18-0.95; P = 0.04 respectively).

CONCLUSION

CAPOX was equivalent to FUOX in terms of tumour response rate, progression-free survival (PFS), and OS in first-line treatment for patients with MCRC, which may be considered as standard first-line treatment in patients with MCRC.

Bioengineered skin in diabetic foot ulcers

OBJECTIVE

Bioengineered skin (BS) has been shown to play an important role in the treatment of diabetic foot ulcers (DFUs). Whether BS in the therapy of DFU can improve the outcomes still remains uncertain. We performed a quantitative meta-analysis of available randomized controlled trials to determine the effectiveness and safety of BS in the treatment of patients with DFUs.

DESIGN AND METHODS

Comprehensive search strategies of various electronic databases were used for this study to evaluate the effectiveness and safety between BS and conventional treatment (CT) in patients with DFU, and only randomized controlled trials were adopted in our review. Search terms included 'bioengineered skin', 'tissue-engineering skin', 'human-tissue graft', 'human-skin device', 'living-skin equivalent' and 'diabetic foot', 'diabetic ulcer', 'diabetic wound'. Analysis outcomes included complete wound closure, complications, ulcer recurrence and adverse severe events (ASEs).

RESULTS

Seven randomized controlled trials on BS vs. CT were included, and 880 participants met inclusion criteria. Pooled analysis showed a significant effectiveness and safety advantages for BS treatment compared to CT for patients with DFUs. In analysis of complications, only statistically significant difference of infection was noted. And no included trials reported ASEs related to these treatments.

CONCLUSIONS

Based on the meta-analysis, patients with DFUs may benefit from the BS because of its high effectiveness and safety and reduced risk for infections in comparison to CT.

rtE218G, a novel hepatitis B virus mutation with resistance to adefovir dipivoxil in patients with chronic hepatitis B

Antiviral therapy is a potentially successful approach for the treatment of patients with Hepatitis B virus (HBV) infection. One antiviral agent is the nucleoside analogue adefovir dipivoxil (ADV). Its efficiency is compromised by the emergence of drug-resistant HBV mutants. Although three major ADV-resistant mutations of HBV are known, rtA181T/V and rtN236T, HBV mutations associated with ADV resistance have not been fully identified. We analyzed DNA sequences that covered a 244 base pair region of the HBV polymerase gene from patients with clinical manifestations of ADV resistance. A novel pattern of amino acid substitutions in HBV polymerase was detected in 26 out of 86 patients. This mutant exhibited a substitution of glycine for glutamic acid at residue 218 (rtE218G). Transient transfection of the HBV replication-competent construct including the rtE218G mutation was performed in HepG2 cells in order to determine the relevance of this mutation to ADV resistance. Phenotypic analyses demonstrated that the rtE218G mutation could independently confer resistance to ADV in vitro, with a 50% inhibitory concentration (IC(50)) 5.5-fold higher than wild-type HBV. RtE218G-mutated HBV also showed a decreased replication capacity in vitro, equal to 87% of wild-type HBV. The present study showed that the rtE218G mutation may be a novel ADV-resistant mutation. Further work will focus on resistance surveillance and cross-resistance analyses, and the molecular mechanisms involved.

Induction with and without antithymocyte globulin combined with cyclosporine/tacrolimus-based immunosuppression in renal transplantation: a meta-analysis of randomized controlled trials

OBJECTIVE

The objective of this study was to conduct a meta-analysis of randomized controlled trials (RCT) to compare the effectiveness and safety of induction with and without antithymocyte globulin (ATG) combined with cyclosporine/tacrolimus-based immunosuppression in renal transplantation.

METHODS

Trials were identified through a computerized literature search of PubMed, EMBASE, Cochrane controlled trials register, Cochrane Renal Group Specialized Register of RCTs, and Chinese Biomedical database. Two independent reviewers assessed trials for eligibility and quality, and then extracted data. Data were extracted for patient and graft survival, acute rejection, the incidence of Banff, cytomegalovirus (CMV) infection, leukopenia, and thrombocytopenia. Dichotomous outcomes were reported as relative risk (RR) with 95% confidence intervals (CI).

RESULTS

Four RCTs (892 patients) were identified. The data showed that induction with ATG was more beneficial than no induction with ATG to reduce the incidence of chronic rejection (RR 0.70; 95% CI, 0.57-0.84) and acute rejection within 6 months (RR 0.68; 95% CI, 0.49-0.96) and at 12 months (RR 0.67; 95% CI, 0.50-0.89) as well as Banff II episodes (RR 0.53; 95% CI, 0.30-0.91), but increased the incidences of CMV infection (RR 1.61; 95% CI, 1.27-2.04) and leukopenia (RR 3.88; 95% CI, 2.80-5.38) and thrombocytopenia (RR 2.92; 95% CI, 1.77-4.04). There was no statistical difference between patient or graft survival rates at 6 and 12 months, as well as the incidences of Banff III or Banff I after transplantation.

CONCLUSION

Based on available data induction with ATG was more efficient to reduce the rate of acute rejection episodes and chronic rejection responses after renal transplantation, but was associated with increased side effects, particularly CMV infections. It is important to provide the most benefit for an individual patient.

[Establishment of method collecting peripheral blood hematopoietic stem/progenitor cells from infants]

The aim of this study was to explore a safe method collecting peripheral blood stem/progenitor cell (PBSPC) from the infants of body weight less than 20 kg by using the COBE Spectra Blood Cell Separator through Auto-PBSC procedure. After washing tube by normal saline, one unit of irradiated RBC was infused into the apheresis set. When the collection terminated, only the concentrated RBC in the apheresis set was returned to the infant. The peripheral mononuclear cells (PBMNCs) and CD34+ cells were counted, the cell viability was determined. The results showed that 13 PBSPC collections were carried out successfully from 7 infants of body weight<20 kg. The average count of MNCs was 4.44x10(8)/kg [(3.46-6.45)x10(8)/kg], the CD34+ count was 2.20x10(6)/kg [(1.34-3.79)x10(6)/kg] and the cell viability was 98.45% (97%-100%) respectively. The vital signs of all the infants went smoothly during collection of PBSPCs. In conclusion, with the aid of COBE Spectra blood cell separator and other measures, the collection of PBSPCs from infants of body weight<20 kg is safe and effective, the PBMNCs containing enough PBSPC can be harvested for transplantation.

Steroid Withdrawal Increases Risk of Acute Rejection but Reduces Infection: A Meta-Analysis of 1681 Cases in Renal Transplantation

OBJECTIVE

To evaluate the safety of steroid withdrawal in renal transplantation recipients.

METHODS

These following databases were searched: Medline (1966 to September 2005), OVID (1966 to 2004), Embase (1984 to 2004), Cochrane library (issue 4, 2005), Highwire (1849 to September 2005), American Transplant Congress (2005), Chinese Biomedicine database (CBM 1994 to 2005). The safety was measured by the following factors: patient and graft survival, acute rejection, chronic rejection, infection, serum creatinine. We performed meta-analysis by using Revman 4.2.7.

RESULTS

Nine randomized clinical trials were identified to have a steroid withdrawal and a steroid continuing group. They included 1681 patients: 845 with steroid withdrawal and 836 with continuing steroid. The risk of acute rejection after steroid withdrawal was two times higher than steroid-continuing group (RR 2.05; 95% confidence interval [CI]: 1.54, 2.72; P < .00001), while the incidence of opportunistic infection and urinary tract infection of steroid withdrawal group were lower than the control group (RR 0.80; 95%CI 0.64, 1.00; P = .05 vs RR 0.74; 95%CI, 0.60, 0.92; P = .004, respectively). The graft and patient survivals, chronic rejection, and serum creatinine were similar to the steroid continuing group.

CONCLUSION

Steroid withdrawal can significantly increase the risk of acute rejection episodes, but reduces the incidence of infection to a certain extent. To prophylaxis against serious infection, steroid withdrawal is worth considering using a sufficient immunosuppressive regimen. The key point is to balance the benefit and harm for the individual recipient.