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1.
PeerJ Comput Sci ; 10: e1973, 2024.
Article in English | MEDLINE | ID: mdl-38660177

ABSTRACT

This research presents the development of a cutting-edge real-time multilingual speech recognition and speaker diarization system that leverages OpenAI's Whisper model. The system specifically addresses the challenges of automatic speech recognition (ASR) and speaker diarization (SD) in dynamic, multispeaker environments, with a focus on accurately processing Mandarin speech with Taiwanese accents and managing frequent speaker switches. Traditional speech recognition systems often fall short in such complex multilingual and multispeaker contexts, particularly in SD. This study, therefore, integrates advanced speech recognition with speaker diarization techniques optimized for real-time applications. These optimizations include handling model outputs efficiently and incorporating speaker embedding technology. The system was evaluated using data from Taiwanese talk shows and political commentary programs, featuring 46 diverse speakers. The results showed a promising word diarization error rate (WDER) of 2.68% in two-speaker scenarios and 11.65% in three-speaker scenarios, with an overall WDER of 6.96%. This performance is comparable to that of non-real-time baseline models, highlighting the system's ability to adapt to various complex conversational dynamics, a significant advancement in the field of real-time multilingual speech processing.

2.
Neural Netw ; 175: 106284, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38593560

ABSTRACT

Anomalous object detection (AOD) in medical images aims to recognize the anomalous lesions, and is crucial for early clinical diagnosis of various cancers. However, it is a difficult task because of two reasons: (1) the diversity of the anomalous lesions and (2) the ambiguity of the boundary between anomalous lesions and their normal surroundings. Unlike existing single-modality AOD models based on deterministic mapping, we constructed a probabilistic and deterministic AOD model. Specifically, we designed an uncertainty-aware prototype learning framework, which considers the diversity and ambiguity of anomalous lesions. A prototypical learning transformer (Pformer) is established to extract and store the prototype features of different anomalous lesions. Moreover, Bayesian neural uncertainty quantizer, a probabilistic model, is designed to model the distributions over the outputs of the model to measure the uncertainty of the model's detection results for each pixel. Essentially, the uncertainty of the model's anomaly detection result for a pixel can reflect the anomalous ambiguity of this pixel. Furthermore, an uncertainty-guided reasoning transformer (Uformer) is devised to employ the anomalous ambiguity, encouraging the proposed model to focus on pixels with high uncertainty. Notably, prototypical representations stored in Pformer are also utilized in anomaly reasoning that enables the model to perceive diversities of the anomalous objects. Extensive experiments on five benchmark datasets demonstrate the superiority of our proposed method. The source code will be available in github.com/umchaohuang/UPformer.


Subject(s)
Bayes Theorem , Uncertainty , Humans , Neural Networks, Computer , Image Processing, Computer-Assisted/methods , Machine Learning , Algorithms , Image Interpretation, Computer-Assisted/methods
3.
Int J Older People Nurs ; 19(2): e12605, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38374792

ABSTRACT

BACKGROUND: Health-related quality of life (HRQOL) is unequal between countries and regions, and the emphasis on HRQOL of populations of low-income countries and regions is unprecedented. OBJECTIVES: To examine the association between family health and HRQOL among middle-aged and older adults in rural China, and determine whether this association differs by age, gender and chronic disease subgroup. METHODS: Cross-sectional survey carried out from July to September 2021. The participants were 1059 people aged 46 and over living in rural China. We used the European Quality of Life Five Dimension Five Level (EQ-5D-5L) and Family Health Scale-Short Form (FHS-SF) to assess health-related quality of life (HRQOL) and family health, respectively. RESULTS: The mean EQ-VAS was 75.66, the mean EQ index score was 0.92, and the mean FHS was 37.90 in rural middle-aged and older adults. After Bonferroni correction, generalised linear regression models showed that FHS was significantly associated with the EQ-VAS (ß = 0.829; 95% confidence interval [CI]: 0.660 to 0.997; p < .001) and the EQ index score (ß = 0.003; 95%CI: 0.001 to 0.004; p < .001). Binary logistic regression models showed that FHS was associated with three dimensions of HRQOL (mobility, self-care and usual activities) (p < .01). Based on subgroup analyses, the effect of FHS on EQ-VAS and the EQ index score was significant in three subgroups after Bonferroni correction (p < .01), but the association between FHS and the dimensions of HRQOL differed by age, gender and chronic disease group (p > .01). CONCLUSIONS: This study is the first to explore that family health and its dimensions are significant positive predictors of HRQOL among middle-aged and older adults in rural China. Family-based measures may have more potential and value because better family health significantly improves HRQOL. IMPLICATIONS FOR PRACTICE: In the health strategy, the government and primary health care workers should include family health as an indicator and assess it before and after the implementation of the strategy.


Subject(s)
Family Health , Quality of Life , Humans , Middle Aged , Aged , Cross-Sectional Studies , China , Chronic Disease , Surveys and Questionnaires , Health Status
4.
Front Pharmacol ; 14: 1072917, 2023.
Article in English | MEDLINE | ID: mdl-36925637

ABSTRACT

Background: Over-the-counter (OTC) drugs facilitates residents self-medication. However, inappropriate self-medications have become a serious problem in China and even all over the world. Objectives: To make an investigation on the current status of Chinese residents' self-medication behaviors and important considerations, and to explore the factors related to the considerations of drug efficacy and safety. Design: A quantitative, cross-sectional study. Methods: Multi-stage sampling was used to conduct a cross-sectional investigation in China 22 provinces, 5 autonomous regions and 4 municipalities directly under the Central Government. State that an interviewer-administrated questionnaire, was used for data collection. The questionnaire that was used in the investigation included demographic sociological characteristics, health literacy scale-short form (HLS-SF), the 10-item Big Five Inventory (BFI-10), the EuroQol-5D visual analogue scale (EQ-5D VAS), self-medication status and important considerations when self-medicating. Descriptive statistics were performed, and the Chi-square test was used for univariate analysis. Log-binomial regression was used for multivariate analysis on whether residents regard drug efficacy or safety as an important consideration. Results: 9256 respondents were included in the data analysis. The self-medication rate of Chinese adults was as high as 99.1%. Paracetamol and other analgesics were the most common types of OTC medication that respondents purchased, followed by vitamins/minerals. Medical staff recommendations, drug safety and efficacy were the top three important considerations. The residents in the east, central and western regions who consider safety is 63.5%, 61.5%, and 66.8% respectively. The proportion of curative effect was 60.2%, 55.7%, and 61.4% respectively. Log-binomial regression showed that western respondents, retired people, those who mainly used ways including basic medical insurance for employees, commercial medical insurance, free medical treatment to cover their medical cost, respondents with high neuroticism, high health literacy were more likely to consider drug safety as an important factor (p < 0.05). Eastern respondents, employed, main way of medical expenses borne was Out-of-pocket Payment, those with chronic disease were more likely to consider drug efficacy as an important factor (p < 0.05). Female, respondents with high levels of agreeableness, conscientiousness, openness, and self-rated health status were more likely to regard both drug safety and efficacy as important considerations (p < 0.05). Conclusion: Self-medication is practiced by most Chinese adults. Whether Chinese adults take drug efficacy or safety as an important consideration is related to their demographic and sociological characteristics, Big Five personality characteristics, health literacy and self-assessed health status. There is a need to strengthen the management of OTC drugs and public education about self-medication.

5.
Front Public Health ; 10: 1036299, 2022.
Article in English | MEDLINE | ID: mdl-36518576

ABSTRACT

Background: Home first-aid kits can play an important role when residents are injured, suddenly become seriously ill or suffer from disasters. Purpose: To explore the home first-aid kit preparedness of Chinese residents and the relationship between demographic sociological characteristics, self-efficacy, Big Five personality, health literacy and home first-aid kit preparation behavior. Methods: A cross-sectional study was conducted. Information was collected through a self-designed questionnaire consisting of sociological characteristics, the New General Self-Efficacy Scale (NGSES), the Health Literacy Scale Short-Form (HLS-SF12), and the 10-item short version of Big Five Inventory (BFI-10). Rank sum test, Chi-square test, and logistic regression were used to explore the relationship between independent variables and home first-aid kit preparation behavior. Results: A total of 9,344 respondents were included, and 2,156 (23.07%) prepared home first-aid kits. Among the respondents who had prepared their home first-aid kits, disinfection supplies (85.20%), medical masks (84.51%), commonly used drugs (82.79%) were the most frequently available. The respondents whose geographic area was Central and Western China, permanent residence in the urban area, secondary education or above, monthly income of 3,000 RMB or above, health care cost-bearing method mainly resident health insurance, high subgroup of self-efficacy, high subgroup of health care dimension in health literacy, and whose openness and conscientiousness was high subgroup were more likely to prepare home first-aid kits (P < 0.05). Conclusion: The preparation rate for home first-aid kits in China is less than a quarter. The public's home first-aid kit preparation behavior is related to demographic characteristics, self-efficacy, health literacy, and the openness of the Big Five personality. A multi-level linked national emergency literacy education system should be established to enhance the residents' attention to home first-aid kits and improve the residents' ability to prevent emergencies.


Subject(s)
Health Literacy , Cross-Sectional Studies , China , Surveys and Questionnaires , Personality
6.
BMC Bioinformatics ; 23(1): 411, 2022 Oct 03.
Article in English | MEDLINE | ID: mdl-36192681

ABSTRACT

BACKGROUND: Biological age (BA) has been recognized as a more accurate indicator of aging than chronological age (CA). However, the current limitations include: insufficient attention to the incompleteness of medical data for constructing BA; Lack of machine learning-based BA (ML-BA) on the Chinese population; Neglect of the influence of model overfitting degree on the stability of the association results. METHODS AND RESULTS: Based on the medical examination data of the Chinese population (45-90 years), we first evaluated the most suitable missing interpolation method, then constructed 14 ML-BAs based on biomarkers, and finally explored the associations between ML-BAs and health statuses (healthy risk indicators and disease). We found that round-robin linear regression interpolation performed best, while AutoEncoder showed the highest interpolation stability. We further illustrated the potential overfitting problem in ML-BAs, which affected the stability of ML-Bas' associations with health statuses. We then proposed a composite ML-BA based on the Stacking method with a simple meta-model (STK-BA), which overcame the overfitting problem, and associated more strongly with CA (r = 0.66, P < 0.001), healthy risk indicators, disease counts, and six types of disease. CONCLUSION: We provided an improved aging measurement method for middle-aged and elderly groups in China, which can more stably capture aging characteristics other than CA, supporting the emerging application potential of machine learning in aging research.


Subject(s)
Aging , Models, Biological , Aged , Biomarkers , Data Mining , Humans , Machine Learning , Middle Aged
7.
Shanghai Kou Qiang Yi Xue ; 31(2): 189-192, 2022 Apr.
Article in Chinese | MEDLINE | ID: mdl-36110078

ABSTRACT

PURPOSE: To assess the prevalence of oral manifestations in a group of allogenic liver, kidney or haematopoietic stem cell transplantation recipients and patients, and analyze the possible oral manifestations associated with the use of 4 immunosuppressive drugs. METHODS: One hundred and eighteen patients submitted to liver, kidney and hematopoietic stem cell transplantation who used tacrolimus, sirolimus,cyclosporine or mycophenolate mofetil were enrolled. Through a questionnaire survey and oral examination, their oral manifestations were recorded, and the possible statistical associations with immunosuppressive drugs were analyzed using SPSS 21.0 software package. RESULTS: The prevalence of oral lichenoid lesions and cheilitis for the group of patients using tacrolimus after transplantation was significantly lower than the group of patients who did not used the agent(P<0.01). The prevalence of oral lichenoid lesions for the group of patients who used cyclosporine was significantly higher than the group of patients who did not used the drug(P<0.05), and the prevalence of cheilitis for the group of patients who used cyclosporine was significantly higher than the group of patients who did not used the drug(P<0.01). The prevalence of oral lichenoid lesions and cheilitis for the group of patients who used tacrolimus was significantly lower than the group of patients who used cyclosporine(P<0.01). The group of patients who used mycophenolate mofetil after transplantation had a significantly lower prevalence of dry mouth than the group of patients who did not used the drug(P<0.01). The prevalence of oral manifestations in patients with sirolimus after transplantation was not significantly reduced. CONCLUSIONS: The use of tacrolimus improved the symptoms of oral lichenoid lesions and cheilitis and the effect was better than cyclosporine after transplantation. The use of mycophenolate mofetil improved dry mouth after organ transplantation.


Subject(s)
Cheilitis , Immunosuppressive Agents , Organ Transplantation , Xerostomia , Cheilitis/prevention & control , Cyclosporine/therapeutic use , Humans , Immunosuppressive Agents/therapeutic use , Mycophenolic Acid/therapeutic use , Sirolimus , Tacrolimus/therapeutic use , Xerostomia/prevention & control
8.
Chin Med J (Engl) ; 135(4): 426-432, 2021 Nov 10.
Article in English | MEDLINE | ID: mdl-34759214

ABSTRACT

BACKGROUND: Contrast-enhanced ultrasound (CEUS) can detect lesions hidden in inflammatory regions and find necrosis or areas of severe fibrosis within the lesion. This retrospective study aimed to compare the diagnostic accuracy of solid pancreatic lesions using percutaneous ultrasound (US)-guided fine-needle aspiration (FNA) with or without CEUS assessment. METHODS: Clinical, imaging, and pathologic data of 181 patients from January 2014 to December 2018 in Pecking Union Medical College Hospital, with solid pancreatic masses who underwent percutaneous US-FNA and ThinPrep cytologic test were retrospectively evaluated. Patients were divided into CEUS and US groups according to whether CEUS was performed before the biopsy. According to FNA cytology diagnoses, we combined non-diagnostic, neoplastic, and negative cases into a negative category. The positive category included malignant, suspicious, and atypical cases. The final diagnosis was confirmed by pathology or clinical and radiological follow-up for at least 12 months. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of US-FNA were evaluated between the two groups. RESULTS: This study enrolled 107 male and 74 female patients (average age: 60 years). There were 58 cases in the US group and 123 cases in the CEUS group. No statistically significant differences in age, gender, or lesion size were found between the two groups. The diagnostic accuracy of the CEUS group was 95.1% (117/123), which was higher than the 86.2% (50/58) observed in the US group (P = 0.036). The sensitivity, specificity, PPV, and NPV of the CEUS group were increased by 7.5%, 16.7%, 3.4%, and 18.8%, respectively, compared with the US group. However, the differences of the two groups were not statistically significant. CONCLUSIONS: Compared with the conventional US, the use of CEUS could improve the biopsy accuracy and avoid the need for a repeat biopsy, especially for some complicated FNA cases.


Subject(s)
Pancreatic Neoplasms , Biopsy, Fine-Needle/methods , Female , Humans , Male , Middle Aged , Pancreatic Neoplasms/diagnostic imaging , Pancreatic Neoplasms/pathology , Retrospective Studies , Sensitivity and Specificity , Ultrasonography, Interventional/methods
9.
Infect Dis Poverty ; 10(1): 21, 2021 Mar 01.
Article in English | MEDLINE | ID: mdl-33648606

ABSTRACT

BACKGROUND: Considering the widespread of coronavirus disease 2019 (COVID-19) pandemic in the world, it is important to understand the spatiotemporal development of the pandemic. In this study, we aimed to visualize time-associated alterations of COVID-19 in the context of continents and countries. METHODS: Using COVID-19 case and death data from February to December 2020 offered by Johns Hopkins University, we generated time-associated balloon charts with multiple epidemiological indicators including crude case fatality rate (CFR), morbidity, mortality and the total number of cases, to compare the progression of the pandemic within a specific period across regions and countries, integrating seven related dimensions together. The area chart is used to supplement the display of the balloon chart in daily new COVID-19 case changes in UN geographic regions over time. Javascript and Vega-Lite were chosen for programming and mapping COVID-19 data in browsers for visualization. RESULTS: From February 1st to December 20th 2020, the COVID-19 pandemic spread across UN subregions in the chronological order. It was first reported in East Asia, and then became noticeable in Europe (South, West and North), North America, East Europe and West Asia, Central and South America, Southern Africa, Caribbean, South Asia, North Africa, Southeast Asia and Oceania, causing several waves of epidemics in different regions. Since October, the balloons of Europe, North America and West Asia have been rising rapidly, reaching a dramatically high morbidity level ranging from 200 to 500/10 000 by December, suggesting an emerging winter wave of COVID-19 which was much bigger than the previous ones. By late December 2020, some European and American countries displayed a leading mortality as high as or over 100/100 000, represented by Belgium, Czechia, Spain, France, Italy, UK, Hungary, Bulgaria, Peru, USA, Argentina, Brazil, Chile and Mexico. The mortality of Iran was the highest in Asia (over 60/100 000), and that of South Africa topped in Africa (40/100 000). In the last 15 days, the CFRs of most countries were at low levels of less than 5%, while Mexico had exceptional high CFR close to 10%. CONCLUSIONS: We creatively used visualization integrating 7-dimensional epidemiologic and spatiotemporal indicators to assess the progression of COVID-19 pandemic in terms of transmissibility and severity. Such methodology allows public health workers and policy makers to understand the epidemics comparatively and flexibly.


Subject(s)
COVID-19/epidemiology , Public Health Surveillance/methods , Computer Graphics , Global Health/statistics & numerical data , Humans , Pandemics/statistics & numerical data , Spatio-Temporal Analysis
13.
Cell Cycle ; 18(8): 898-913, 2019 04.
Article in English | MEDLINE | ID: mdl-30975033

ABSTRACT

Besides TopBP1, ETAA1 has been identified more recently as an activator of the ATR-ATRIP complex in human cells. We have examined the role of ETAA1 in the Xenopus egg-extract system, which has been instrumental in the study of ATR-ATRIP. Depletion of ETAA1 from egg extracts did not noticeably reduce the activation of ATR-ATRIP in response to replication stress, as monitored by the ATR-dependent phosphorylation of Chk1 and RPA. Moreover, lack of ETAA1 did not appear to affect DNA replication during an unperturbed S-phase. Significantly, we find that TopBP1 is considerably more abundant than ETAA1 in egg extracts. We proceeded to show that ETAA1 could support the activation of ATR-ATRIP in response to replication stress if we increased its concentration in egg extracts by adding extra full-length recombinant ETAA1. Thus, TopBP1 appears to be the predominant activator of ATR-ATRIP in response to replication stress in this system. We have also explored the biochemical mechanism by which ETAA1 activates ATR-ATRIP. We have developed an in vitro system in which full-length recombinant ETAA1 supports activation of ATR-ATRIP in the presence of defined components. We find that binding of ETAA1 to RPA associated with single-stranded DNA (ssDNA) greatly stimulates its ability to activate ATR-ATRIP. Thus, RPA-coated ssDNA serves as a direct positive effector in the ETAA1-mediated activation of ATR-ATRIP.


Subject(s)
Antigens, Surface/metabolism , DNA, Single-Stranded/metabolism , Replication Protein A/metabolism , Adaptor Proteins, Signal Transducing/metabolism , Animals , Antibodies/immunology , Antigens, Surface/immunology , Ataxia Telangiectasia Mutated Proteins/metabolism , Checkpoint Kinase 1/metabolism , Chromatin/metabolism , DNA Replication/immunology , DNA-Binding Proteins/metabolism , Phosphorylation/immunology , Protein Binding , Recombinant Proteins/metabolism , S Phase/immunology , Xenopus , Xenopus Proteins/metabolism
14.
Chin Med J (Engl) ; 129(23): 2816-2823, 2016 12 05.
Article in English | MEDLINE | ID: mdl-27900995

ABSTRACT

BACKGROUND: Nowadays, social media tools such as short message service, Twitter, video, and web-based systems are more and more used in clinical follow-up, making clinical follow-up much more time- and cost-effective than ever before. However, as the most popular social media in China, little is known about the utility of smartphone WeChat application in follow-up. In this study, we aimed to investigate the feasibility and superiority of WeChat application in clinical follow-up. METHODS: A total of 108 patients diagnosed with head and neck tumor were randomized to WeChat follow-up (WFU) group or telephone follow-up (TFU) group for 6-month follow-up. The follow-ups were delivered by WeChat or telephone at 2 weeks, 1, 2, 3, and 6 months to the patients after being discharged. The study measurements were time consumption for follow-up delivery, total economic cost, lost-to-follow-up rate, and overall satisfaction for the follow-up method. RESULTS: Time consumption in WFU group for each patient (23.36 ± 6.16 min) was significantly shorter than that in TFU group (42.89 ± 7.15 min) (P < 0.001); total economic cost in WFU group (RMB 90 Yuan) was much lower than that in TFU group (RMB 196 Yuan). Lost-to-follow-up rate in the WFU group was 7.02% (4/57) compared with TFU group, 9.80% (5/51), while no significance was observed (95% confidence interval [CI]: 0.176-2.740; P = 0.732). The overall satisfaction rate in WFU group was 94.34% (50/53) compared with 80.43% (37/46) in TFU group (95% CI: 0.057-0.067; P = 0.034). CONCLUSIONS: The smartphone WeChat application was found to be a viable option for follow-up in discharged patients with head and neck tumors. WFU was time-effective, cost-effective, and convenient in communication. This doctor-led follow-up model has the potential to establish a good physician-patient relationship by enhancing dynamic communications and providing individual health instructions. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR-IOR-15007498; http://www.chictr.org.cn/ showproj.aspx?proj=12613.


Subject(s)
Aftercare/economics , Aftercare/methods , Head and Neck Neoplasms , Patient Discharge/economics , Patient Discharge/statistics & numerical data , Smartphone , Social Media , Adult , Aged , Female , Humans , Male , Middle Aged , Telephone , Young Adult
15.
J Virol ; 89(12): 6196-208, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25833050

ABSTRACT

UNLABELLED: Human enterovirus 71 (EV71) and coxsackievirus A16 (CVA16) are the two major causative agents for hand-foot-and-mouth disease (HFMD). Previously, we demonstrated that a virus-like particle (VLP) for EV71 produced from Saccharomyces cerevisiae is a potential vaccine candidate against EV71 infection, and an EV71/CVA16 chimeric VLP can elicit protective immune responses against both virus infections. Here, we presented the crystal structures of both VLPs, showing that both the linear and conformational neutralization epitopes identified in EV71 are mostly preserved on both VLPs. The replacement of only 4 residues in the VP1 GH loop converted strongly negatively charged surface patches formed by portions of the SP70 epitope in EV71 VLP into a relatively neutral surface in the chimeric VLP, which likely accounted for the additional neutralization capability of the chimeric VLP against CVA16 infection. Such local variations in the amino acid sequences and the surface charge potential are also present in different types of polioviruses. In comparison to EV71 VLP, the chimeric VLP exhibits structural changes at the local site of amino acid replacement and the surface loops of all capsid proteins. This is consistent with the observation that the VP1 GH loop located near the pseudo-3-fold junction is involved in extensive interactions with other capsid regions. Furthermore, portions of VP0 and VP1 in EV71 VLP are at least transiently exposed, revealing the structural flexibility of the VLP. Together, our structural analysis provided insights into the structural basis of enterovirus neutralization and novel vaccine design against HFMD and other enterovirus-associated diseases. IMPORTANCE: Our previous studies demonstrated that the enterovirus 71 (EV71) virus-like particle (VLP) produced from yeast is a vaccine candidate against EV71 infection and that a chimeric EV71/coxsackievirus A16 (CVA16) VLP with the replacement of 4 amino acids in the VP1 GH loop can confer protection against both EV71 and CVA16 infections. This study reported the crystal structures of both the EV71 VLP and the chimeric EV71/CVA16 VLP and revealed that the major neutralization epitopes of EV71 are mostly preserved in both VLPs. In addition, the mutated VP1 GH loop in the chimeric VLP is well exposed on the particle surface and exhibits a surface charge potential different from that contributed by the original VP1 GH loop in EV71 VLP. Together, this study provided insights into the structural basis of enterovirus neutralization and evidence that the yeast-produced VLPs can be developed into novel vaccines against hand-foot-and-mouth disease (HFMD) and other enterovirus-associated diseases.


Subject(s)
Hand, Foot and Mouth Disease/prevention & control , Vaccines, Virus-Like Particle/isolation & purification , Viral Vaccines/isolation & purification , Amino Acid Sequence , Crystallography, X-Ray , Enterovirus/chemistry , Enterovirus/genetics , Enterovirus/immunology , Enterovirus A, Human/chemistry , Enterovirus A, Human/genetics , Enterovirus A, Human/immunology , Epitopes/chemistry , Epitopes/immunology , Humans , Models, Molecular , Molecular Sequence Data , Protein Conformation , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Sequence Alignment , Vaccines, Synthetic/chemistry , Vaccines, Synthetic/immunology , Vaccines, Synthetic/isolation & purification , Vaccines, Virus-Like Particle/chemistry , Vaccines, Virus-Like Particle/immunology , Viral Vaccines/chemistry , Viral Vaccines/immunology
16.
J Biol Chem ; 290(6): 3198-208, 2015 Feb 06.
Article in English | MEDLINE | ID: mdl-25492868

ABSTRACT

Hand-foot-and-mouth disease (HFMD) remains a major health concern in the Asia-Pacific regions, and its major causative agents include human enterovirus 71 (EV71) and coxsackievirus A16. A desirable vaccine against HFMD would be multivalent and able to elicit protective responses against multiple HFMD causative agents. Previously, we have demonstrated that a thermostable recombinant EV71 vaccine candidate can be produced by the insertion of a foreign peptide into the BC loop of VP1 without affecting viral replication. Here we present crystal structures of two different naturally occurring empty particles, one from a clinical C4 strain EV71 and the other from its recombinant virus containing an insertion in the VP1 BC loop. Crystal structure analysis demonstrated that the inserted foreign peptide is well exposed on the particle surface without significant structural changes in the capsid. Importantly, such insertions do not seem to affect the virus uncoating process as illustrated by the conformational similarity between an uncoating intermediate of another recombinant virus and that of EV71. Especially, at least 18 residues from the N terminus of VP1 are transiently externalized. Altogether, our study provides insights into vaccine development against HFMD.


Subject(s)
Capsid/chemistry , Enterovirus A, Human/chemistry , Vaccines, Virus-Like Particle/chemistry , Amino Acid Sequence , Capsid/ultrastructure , Crystallography, X-Ray , Enterovirus A, Human/genetics , Enterovirus A, Human/immunology , Molecular Sequence Data
17.
J Virol ; 88(6): 3114-26, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24352461

ABSTRACT

UNLABELLED: Human enterovirus 71 (EV71) is the major causative agent of severe hand-foot-and-mouth diseases (HFMD) in young children, and structural characterization of EV71 during its life cycle can aid in the development of therapeutics against HFMD. Here, we present the atomic structures of the full virion and an uncoating intermediate of a clinical EV71 C4 strain to illustrate the structural changes in the full virion that lead to the formation of the uncoating intermediate prepared for RNA release. Although the VP1 N-terminal regions observed to penetrate through the junction channel at the quasi-3-fold axis in the uncoating intermediate of coxsackievirus A16 were not observed in the EV71 uncoating intermediate, drastic conformational changes occur in this region, as has been observed in all capsid proteins. Additionally, the RNA genome interacts with the N-terminal extensions of VP1 and residues 32 to 36 of VP3, both of which are situated at the bottom of the junction. These observations highlight the importance of the junction for genome release. Furthermore, EV71 uncoating is associated with apparent rearrangements and expansion around the 2- and 5-fold axes without obvious changes around the 3-fold axes. Therefore, these structures enabled the identification of hot spots for capsid rearrangements, which led to the hypothesis that the protomer interface near the junction and the 2-fold axis permits the opening of large channels for the exit of polypeptides and viral RNA, which is an uncoating mechanism that is likely conserved in enteroviruses. IMPORTANCE: Human enterovirus 71 (EV71) is the major causative agent of severe hand-foot-and-mouth diseases (HFMD) in young children. EV71 contains an RNA genome protected by an icosahedral capsid shell. Uncoating is essential in EV71 life cycle, which is characterized by conformational changes in the capsid to facilitate RNA release into host cell. Here we present the atomic structures of the full virion and an uncoating intermediate of a clinical C4 strain of EV71. Structural analysis revealed drastic conformational changes associated with uncoating in all the capsid proteins near the junction at the quasi-3-fold axis and protein-RNA interactions at the bottom of the junction in the uncoating intermediate. Significant capsid rearrangements also occur at the icosahedral 2- and 5-fold axes but not at the 3-fold axis. Taking the results together, we hypothesize that the junction and nearby areas are hot spots for capsid breaches for the exit of polypeptides and viral RNA during uncoating.


Subject(s)
Capsid/chemistry , Enterovirus A, Human/chemistry , Hand, Foot and Mouth Disease/virology , Capsid/metabolism , Capsid Proteins/chemistry , Capsid Proteins/genetics , Capsid Proteins/metabolism , Crystallization , Enterovirus A, Human/genetics , Enterovirus A, Human/metabolism , Humans , Models, Molecular
18.
Proc Natl Acad Sci U S A ; 110(19): 7619-24, 2013 May 07.
Article in English | MEDLINE | ID: mdl-23589862

ABSTRACT

The development of vaccines against infectious diseases represents one of the most important contributions to medical science. However, vaccine-preventable diseases still cause millions of deaths each year due to the thermal instability and poor efficacy of vaccines. Using the human enterovirus type 71 vaccine strain as a model, we suggest a combined, rational design approach to improve the thermostability and immunogenicity of live vaccines by self-biomineralization. The biomimetic nucleating peptides are rationally integrated onto the capsid of enterovirus type 71 by reverse genetics so that calcium phosphate mineralization can be biologically induced onto vaccine surfaces under physiological conditions, generating a mineral exterior. This engineered self-biomineralized virus was characterized in detail for its unique structural, virological, and chemical properties. Analogous to many exteriors, the mineral coating confers some new properties on enclosed vaccines. The self-biomineralized vaccine can be stored at 26 °C for more than 9 d and at 37 °C for approximately 1 wk. Both in vitro and in vivo experiments demonstrate that this engineered vaccine can be used efficiently after heat treatment or ambient temperature storage, which reduces the dependence on a cold chain. Such a combination of genetic technology and biomineralization provides an economic solution for current vaccination programs, especially in developing countries that lack expensive refrigeration infrastructures.


Subject(s)
Enterovirus A, Human/genetics , Genetic Engineering/methods , Peptides/chemistry , Protein Engineering/methods , Viral Vaccines/chemistry , Animals , Chlorocebus aethiops , Enterovirus A, Human/immunology , Humans , Immunization , Mice , Mice, Inbred BALB C , Temperature , Vero Cells , Viral Vaccines/immunology
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