Factors affecting the compliance of hepatocellular carcinoma screening among high-risk populations: A systematic review and meta-analysis.

BACKGROUND: Hepatocellular carcinoma (HCC) is the sixth most common cancer worldwide and the third leading cause of cancer mortality. HCC has high morbidity, high mortality, and low survival rates. Screening is one of the most significant methods of lowering incidence and death while also increasing survival. OBJECTIVES: The aim of this study was to identify the facilitators and barriers to participation in HCC screening among high-risk populations. METHODS: A comprehensive and systematic search was undertaken in PubMed, Web of Science, MEDLINE, EMBACE, EBSCOhost and the Cochrane Library. A combination of synonyms of the keywords including HCC, screening, factors and adherence were used for searching. Studies addressing the facilitators and barriers to HCC screening compliance in at-risk individuals were included. Data were synthesized using Review Manager version 5.4. A random/fixed effects model meta-analysis was performed to estimate the pooled data and expressed with odds ratio (OR) and 95% confidence interval (CI). RESULTS: A total of seven articles met the inclusion criteria. Qualitative (n = 1) and quantitative (n = 6) studies using various types of surgery were conducted. The most commonly mentioned barriers were insufficient knowledge and awareness of HCC screening, unawareness of the necessity for early detection of HCC and lack of physician recommendation. A meta-analysis of seven studies showed that individuals with a family history of HCC increased screening uptake by nearly three times (OR: 2.69, 95% CI: 1.93, 3.75). Other most frequently reported facilitators include age, education level, and perceived risk et al. CONCLUSIONS: Many barriers to HCC screening were found. Meanwhile, this review points out that improving the awareness of high-risk populations toward HCC screening is expected to enhance compliance, thereby promoting early diagnosis of liver cancer, reducing mortality, and alleviating the burden of HCC.

Knowledge and belief of fecal occult blood screening: A systematic review.

INTRODUCTION: Colorectal cancer (CRC) is associated with a high incidence and mortality rate. Fecal occult blood test (FOBT) is effective in the prevention of CRC. OBJECTIVE: This study aimed to assess knowledge and beliefs regarding FOBT-based screening. METHODS: This study used PubMed, Cochrane Library, MEDLINE Complete, and Web of Science to search for articles. Original full-text studies in English language focusing on knowledge and beliefs of FOBT screening were included. RESULTS: A total of 32 articles were included. This study indicated that the population in most studies had inadequate knowledge and lacked beliefs toward FOBT-based screening. Most of the extracted studies showed that less than half of the participants had heard of FOBT-based screening. Six studies showed that less than 50% of participants had knowledge of FOBT age. Three studies found that less than 40% of participants were aware of the screening interval. Some participants perceived the benefits of FOBT-based screening, while others perceived many barriers to the test. CONCLUSION: Participants' knowledge and belief in FOBT-based screening were insufficient. This review highlights the importance of educational programs to increase knowledge and beliefs regarding FOBT-based screening. It is important to include FOBT-based screening in the health care system to promote the secondary prevention of CRC.

Potential for elimination of SAR-CoV-2 through vaccination as inspired by elimination of multiple influenza viruses through natural pandemics or mass vaccination.

The ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by the novel virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has claimed many lives worldwide. To combat the pandemic, multiple types of vaccines are under development with unprecedented rapidity. Theoretically, future vaccination against COVID-19 may fall into long-term costly guerrilla warfare between SARS-CoV-2 and humans. Elimination of SARS-CoV-2 through vaccination to avoid the potential long-term costly guerrilla warfare, if possible, is highly desired and worth intensive consideration. Human influenza pandemics emerging in 1957, 1968, and 2009 established strong global herd immunity and led to the elimination of three human influenza viruses, which circulated worldwide for years before the pandemics. Moreover, both clade 7.2 of subtype H5 highly pathogenic avian influenza virus and subtype H7N9 avian influenza virus circulated in poultry in China for years, and they have been virtually eliminated through mass vaccination in recent years. These facts suggest that the rapid establishment of global herd immunity through mass vaccination using an appropriate vaccine could eliminate SARS-CoV-2. The coming 2 years are a golden time for elimination through vaccination, which requires tremendous national and international collaboration. This review also prioritizes the efficacy of vaccines for COVID-19 and elucidates the importance of the development of more live vaccines for COVID-19.

CARsomes inhibit airway allergic inflammation in mice by inducing antigen-specific Th2 cell apoptosis.

BACKGROUND: Skewed T helper (Th)2 response plays a crucial role in the pathogenesis of allergic diseases. The therapeutic efficacy for allergic diseases is unsatisfactory currently. This study aims to regulate the skewed Th2 response with CARsomes. METHODS: The CARsome consisted of an epitope of Dermatophagoides farina-1 (Derf1), a segment of the anti-DEC205 antibody, the scFv, and an open reading frame of perforin. This fusion protein binds to DEC205 molecule on the surface of exosomes derived from dendritic cells (DC). The effects of CARsome on inducing antigen (Ag)-specific Th2 cell apoptosis were assessed both in vivo and in vitro. RESULTS: Exposure to CARsomes in the culture induced Ag-specific Th2 cell apoptosis. Injection of CARsomes through the vein puncture also induced Ag-specific Th2 cell apoptosis in the lungs of sensitized mice. CARsomes could induce Ag-specific regulatory T cells. Administration of CARsomes efficiently inhibited experimental allergic airway inflammation. CONCLUSIONS: The CARsomes can inhibit allergic airway inflammation by inducing Ag-specific Th2 cell apoptosis and induce Ag-specific regulatory T cells. The data suggest that CARsomes have the translational potential to be used to treat allergic airway inflammation.

Thrombospondin-1 (TSP1)-producing B cells restore antigen (Ag)-specific immune tolerance in an allergic environment.

Restoration of the antigen (Ag)-specific immune tolerance in an allergic environment is refractory. B cells are involved in immune regulation. Whether B cells facilitate the generation of Ag-specific immune tolerance in an allergic environment requires further investigation. This paper aims to elucidate the mechanism by which B cells restore the Ag-specific immune tolerance in an allergic environment. In this study, a B cell-deficient mouse model was created by injecting an anti-CD20 antibody. The frequency of tolerogenic dendritic cell (TolDC) was assessed by flow cytometry. The levels of cytokines were determined by enzyme-linked immunosorbent assay. The expression of thrombospondin-1 (TSP1) was assessed by quantitative real-time RT-PCR, Western blotting, and methylation-specific PCR. The results showed that B cells were required in the generation of the TGF-ß-producing TolDCs in mice. B cell-derived TSP1 converted the latent TGF-ß to the active TGF-ß in DCs, which generated TGF-ß-producing TolDCs. Exposure to IL-13 inhibited the expression of TSP1 in B cells by enhancing the TSP1 gene DNA methylation. Treating food allergy mice with Ag-specific immunotherapy and IL-13 antagonists restored the generation of TolDCs and enhanced the effect of specific immunotherapy. In conclusion, B cells play a critical role in the restoration of specific immune tolerance in an allergic environment. Blocking IL-13 in an allergic environment facilitated the generation of TolDCs and enhanced the therapeutic effect of immunotherapy.

Interventions to Improve Endoscopic Screening Adherence of Cancer in High-Risk Populations: A Scoping Review.

Background: Colorectal, and gastric cancers have the second, and fourth mortality rates worldwide, respectively. Endoscopic screening is a crucial diagnostic tool for colorectal, and gastric cancers. Effective interventions can improve adherence to endoscopic screening in high-risk populations, which is important for cancer prevention and mortality reduction. This study aimed to identify interventions that could improve adherence to endoscopic screening for cancer in high-risk populations. Methods: Combination keywords including colorectal cancer, gastric cancer, screening adherence, and interventions were used to search for articles in PubMed, Web of Science, Cochrane Library, and MEDLINE Complete. The review methodology was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-SCR). Results: A total of 12 articles were included in this review: 9 randomized controlled trials(RCT) and 3 quasi-experimental studies(QEDs). Among the extracted studies, 11 were about colorectal cancer, and 1 was about gastric cancer. Most studies used lecture-based or Information Technology-based health education interventions. Narrative interventions have proven to be novel and effective approaches for promoting adherence to endoscopic screening. Health education interventions included cancer epidemiology, cancer risk factors, warning symptoms, and screening methods. Conclusion: All interventions involved were effective in increasing individual knowledge of cancer-related endoscopic screening, willingness to undergo screening, and screening behaviors. These findings provide a reference for designing endoscopy-related cancer screening interventions.

What is the general Chinese public's awareness of and attitudes towards Helicobacter pylori screening and associated health behaviours? A cross-sectional study.

OBJECTIVE: To evaluate the general population's awareness of and attitudes toward Helicobacter pylori (HP) screening and health behaviours. DESIGN: Cross-sectional study. SETTING: Hengyang, Hunan Province, China. PARTICIPANTS: Using stratified cluster random sampling, a pretested structured questionnaire was used to interview members of the general population aged ≥18 years. PRIMARY AND SECONDARY OUTCOME MEASURES: Knowledge of and attitudes toward HP screening and associated health behaviours, sociodemographic factors associated with HP knowledge, and screening behaviours. RESULTS: This study featured 1042 participants. The average knowledge score was 11 (QL=4, QU=20, range 0-29). Approximately 68.9% of the participants said they had heard of HP, but 67.5% had never had an HP test. The most common reasons for not undergoing screening were 'no symptoms' (55.7%) and 'lack of knowledge regarding the benefits of the test' (21.1%). Independent factors related to knowledge included age, education level, occupation, HP infection, frequency of drinking unboiled water (p<0.05). Factors independently associated with screening behaviour included occupation, average monthly income, presence/absence of indigestion, stomach discomfort or pain, and/or stomach disease and knowledge score (p<0.05). Overall, 941 (90.3%) participants never used anti-HP toothpaste, and 442 (40.5%) never used serving spoons or chopsticks. The risk factors for HP infection included eating out and eating in groups (p<0.05). CONCLUSION: In China, the general population has poor knowledge of HP, but most people have a positive attitude towards HP screening. Being asymptomatic and lacking knowledge about testing were the main reasons for reluctance to be screened. These results highlight the urgent need for educational activities to raise awareness, enhance screening rates for HP, and encourage people to adopt a healthy lifestyle.

Literature review and report of three cases of Dubin-Johnson syndrome related to ABCC2 gene mutations in children.

OBJECTIVE: The aim of the present study was to analyze the clinical features of Dubin-Johnson syndrome (DJS) related to ABCC2 gene mutations in children and to review the relevant literature to improve understanding of this type of genetic disease and reduce misdiagnosis. METHODS: Three children with clinically suspected DJS who were treated at Beijing Children's Hospital of Capital Medical University between 2017 and 2020 were enrolled in the study. The target genes were captured and sequenced using GenCap target gene capture technology and a new generation of high-throughput sequencing technology (Beijing Mykino Company). The clinical and genetic characteristics were analyzed and summarized. RESULTS: Two of the cases were female and one was male. All three cases were in early infancy and in good general health. Case 1 was complicated with unilateral hypertrophy, Case 2 was complicated with pneumonia, anemia, myocardial injury, and bilateral inguinal hernia, and Case 3 was complicated with patent foramen ovale and a ventricular septal defect. In all three cases, total bilirubin was elevated, with the main increase being in direct bilirubin (DBIL) and varying degrees of elevated alanine aminotransferase (ALT), γ-glutamyl transferase (GGT), and total bile (TBA). Genetic testing indicated that there were seven gene mutations in ABCC2, two mutation sites of which had not been reported previously. CONCLUSION: The clinical manifestations of DJS are non-specific and are mainly characterized by elevated DBIL. Some children might have different degrees of hepatic function abnormality and cholestasis. Due to the lack of serological markers, the diagnosis of DJS is difficult, but genetic testing, along with the formation of pedigree analysis and verification, could be used for accurate diagnosis. Novel mutations might enrich the spectrum of ABCC2 gene mutation.

Chlorinated effluent organic matter causes higher toxicity than chlorinated natural organic matter by inducing more intracellular reactive oxygen species.

During unplanned indirect potable reuse, treated wastewater that contains effluent organic matter (EOM) enters the drinking water source, resulting in different toxicity from natural organic matter (NOM) in surface water during chlorination. This study found that, during chlorination, EOM formed more total organic halogen (TOX) and highly toxic nitrogenous disinfection byproducts (DBPs) like dichloroacetonitrile and trichloronitromethane than NOM did. Oxidative stress including both reactive oxygen species (ROS) and reactive nitrogen species (RNS) in Chinese hamster ovary (CHO) cells substantially increased when exposed to chlorinated EOM and chlorinated NOM. The excessive ROS damaged biological macromolecules including DNA, RNA to form 8-hydroxy-(deoxy)guanosine and proteins to form protein carbonyls. Impaired macromolecule further triggered cell cycle arrest at the S and G2 phases, led to cell apoptosis and eventual necrosis. Cytotoxicity and genotoxicity of chlorinated EOM were both higher than those of chlorinated NOM. Adding the blocker L-buthionine-sulfoximine of intracellular antioxidant glutathione demonstrating that oxidative stress might be responsible for toxicity. ROS was further identified to be the main cause of toxicity induction. These findings highlight the risk from chlorinated EOM in the case of unplanned indirect potable reuse, because it showed higher level of cytotoxicity and genotoxicity than chlorinated NOM via inducing more ROS in mammalian cells.

[Clinical efficacy and safety of acupuncture combined with western medicine in treatment of children with abdominal Henoch-Schonlein purpura with spleen-stomach damp-heat syndrome].

OBJECTIVE: To investigate the clinical effect of acupuncture combined with western medicine in the treatment of children with abdominal Henoch-Schonlein purpura with spleen-stomach damp-heat syndrome. METHODS: A total of 60 children with abdominal Henoch-Schonlein purpura with spleen-stomach damp-heat syndrome were randomly divided into treatment group and control group, with 30 patients in each group. The patients in the control group were given Hydroprednisone 2 mg•kg-1•d-1, and in addition to the treatment in the control group, those in the treatment group were given acupuncture at Tianshu (ST25), Neiguan (PC6), Zusanli (ST36), Zhongwan (CV12), Qihai (CV6), and Sanyinjiao (SP6) once a day, with a needle retaining time of 15 minutes. Both groups were treated for 7 days. The scores of abdominal pain, hematochezia, hematemesis, vomiting, poor appetite, abdominal distension, purpura, occult blood in stool, and abdominal ultrasound were determined before and after treatment, and the time to the disappearance of abdominal pain was observed. Clinical outcome was evaluated. RESULTS: The treatment group had a significantly higher effective rate than the control group ［96.7% (29/30) vs 80.0% (24/30), P<0.05］. Both groups had significant reductions in the scores of abdominal pain, hematochezia, hematemesis, poor appetite, abdominal distension, purpura, occult blood and abdominal ultrasound and the total score after treatment (P<0.05), and compared with the control group after treatment, the treatment group had significantly lower scores of abdominal pain, poor appetite, abdominal distension, and abdominal ultrasound and total score (P<0.05). The treatment group had a significantly shorter time to disappea-rance of abdominal pain than the control group (P<0.05). CONCLUSION: Acupuncture combined with western medicine has a better clinical effect than western medicine alone in the treatment of abdominal Henoch-Schonlein purpura with spleen-stomach damp-heat syndrome and can significantly improve clinical symptoms and signs and shorten the time to disappearance of abdominal pain.

Panorama phylogenetic diversity and distribution of type A influenza viruses based on their six internal gene sequences.

BACKGROUND: Type A influenza viruses are important pathogens of humans, birds, pigs, horses and some marine mammals. The viruses have evolved into multiple complicated subtypes, lineages and sublineages. Recently, the phylogenetic diversity of type A influenza viruses from a whole view has been described based on the viral external HA and NA gene sequences, but remains unclear in terms of their six internal genes (PB2, PB1, PA, NP, MP and NS). METHODS: In this report, 2798 representative sequences of the six viral internal genes were selected from GenBank using the web servers in NCBI Influenza Virus Resource. Then, the phylogenetic relationships among the representative sequences were calculated using the software tools MEGA 4.1 and RAxML 7.0.4. Lineages and sublineages were classified mainly according to topology of the phylogenetic trees and distribution of the viruses in hosts, regions and time. RESULTS: The panorama phylogenetic trees of the six internal genes of type A influenza viruses were constructed. Lineages and sublineages within the type based on the six internal genes were classified and designated by a tentative universal numerical nomenclature system. The diversity of influenza viruses circulating in different regions, periods, and hosts based on the panorama trees was analyzed. CONCLUSION: This study presents the first whole views to the phylogenetic diversity and distribution of type A influenza viruses based on their six internal genes. It also proposes a tentative universal nomenclature system for the viral lineages and sublineages. These can be a candidate framework to generalize the history and explore the future of the viruses, and will facilitate future scientific communications on the phylogenetic diversity and evolution of the viruses. In addition, it provides a novel phylogenetic view (i.e. the whole view) to recognize the viruses including the origin of the pandemic A(H1N1) influenza viruses.

Effect of bromide on the formation of disinfection by-products during wastewater chlorination.

The effect of bromide ion on the formation and speciation of trihalomethanes (THMs) and haloacetic acids (HAAs) during the chlorination of biologically treated wastewaters was investigated. The experimental results showed that the formation of total THMs and total HAAs during chlorine disinfection increased with increasing bromide levels in wastewater. The formation of CHBr(3) increased nearly linearly with increasing bromide ion levels, while CHCl(2)Br and CHClBr(2) increased with increasing bromide concentration from 0 to 3.2 mg L(-1) and thereafter remained constant or slightly decreased. Increasing initial bromide levels up to 12.8mgL(-1) resulted in sharp decrease of the concentration of CHCl(3) and chloro- HAAs. The mixed bromochloro- HAAs and bromo-only species replaced chloro- HAAs as the dominated species of HAA with increasing bromide levels. The distribution of monohalogenated, dihalogenated and trihalogenated species of HAAs in chlorinated wastewater at high concentration of bromide (>2 mg L(-1)) is different from that of drinking/natural water. The values of the bromine incorporation factors, n (Br) and n' (Br), increased with increasing bromide concentration and remained constant or slightly decreased with increasing contact time under the studied range of bromide ion concentrations during chlorination. Moreover, the bromine incorporation into THMs was higher than that of HAAs with bromide levels ranging from 1.0 to 12.8 mg L(-1), indicating the dissimilar formation mechanisms of THMs and HAAs involving bromide.

A survey of human cases of H5N1 avian influenza reported by the WHO before June 2006 for infection control.

H5N1 avian influenza has been widely spreading in fowls in the Eastern Hemisphere and caused hundreds of severe human cases. Here, the information of the 224 human cases of H5N1 avian influenza reported by the World Health Organization before June 2006 were surveyed and analyzed. The results suggested that human infections escalated in the past 3 years, and control of animal H5N1 influenza, avoidance of high-risk behaviors, and proper disposal of diseased or dead fowls are vital for the prevention of the human infections. Age distribution of the human cases demonstrated that older people are more immune to the infection, possibly because of the cross protectivity induced by their previous infections with human influenza A viruses. This survey also suggested that live vaccines against human influenza may be of utility in the prevention of the avian influenza virus infections in humans, and new preventive measures should be considered for the control of animal H5N1 influenza epidemics, which are likely more serious than indicated by official reports.

A survey of human cases of H5N1 avian influenza reported by the WHO before June 2006 for infection control.

H5N1 avian influenza has been widely spreading in fowl in the Eastern Hemisphere and has caused hundreds of severe human cases. Here, information regarding the 224 human cases of H5N1 avian influenza reported by the World Health Organization (WHO) before June 2006 were surveyed and analyzed. The results suggested that human infections escalated in the past 3 years and that control of animal H5N1 influenza, avoidance of high-risk behaviors, and proper disposal of diseased or dead fowl are vital for the prevention of human infections. Age distribution of the human cases demonstrated that older people are more immune to the infection, possibly because of the cross protectivity induced by their previous infection with human influenza A viruses. This survey also suggested that live vaccines against human influenza may be of utility in the prevention of avian influenza virus infection in humans and that new preventive measures should be considered for the control of animal H5N1 influenza epidemics, which are likely more numerous than indicated by official reports.

Determination of haloacetic acids in hospital effluent after chlorination by ion chromatography.

The ion chromatography combined solid phase extraction (SPE) method was developed for the analysis of low concentration haloacetic acids (HAAs), a class of disinfection by-products formed from chlorination of hospital wastewater. The monitored HAAs included monochloroacetic acid, monobromoacetic acid, dichloroacetic acid, dibromoacetic acid and trichloroacetic acid. The method employed a sodium hydroxide eluent at a flow rate of 0.8 ml/min, electrolytically generated gradients, and suppressed conductivity detection. To analyze the HAAs in real hospital wastewater samples, C18 pretreatment cartridge was utilized to reduce samples' turbidity. Preconcentration with SPE and matrix elimination with treatment cartridges were investigated and found to be able to obtain acceptable detection limits. Linearity, repeatability and detection limits of the above method were evaluated. The detection limits of monobromoacetic acid and dibromoacetic acid were 2.61 microg/L and 1.30 microg/L, respectively, and the other three acids are ranging from 0.48 to 0.82 microg/L under 25-fold preconcentration. When the above optimization procedure was applied to three hospital wastewater samples with different treatment processes in Tianjin, it was found that the dichloroacetic acid was the major compound, and the growth ratios of the HAAs after disinfection by sodium hypochlorite were 91.28%, 63.61% and 79.50%, respectively.

Characterization of trihalomethane, haloacetic acid, and haloacetonitrile precursors in a seawater reverse osmosis system.

Seawater reverse osmosis (SWRO) has been extensively applied to replenish the limited freshwater resources. One concern of such technology is the formation of disinfection by-products (DBPs) during the pre-chlorination process. For the SWRO tested in this study, the concentrations of trihalomethanes (THMs), haloacetic acids (HAAs), and haloacetonitriles (HANs) increased by 35.1, 23.7 and 4.9µg/L, respectively, after a seawater sample (with UV254/DOC of 3.7L/mg·m and Br- of 50.9mg/L) was pre-chlorinated (1-2mg-Cl2/L). The dissolved organic matter (DOM) with molecular weight (MW) <1kDa dominated the formation of total THMs, HAAs and HANs. To further investigate DBPs precursors in the seawater, the DOM with MW<1kDa was fractionated to hydrophobic acids (HOA), hydrophobic bases (HOB), hydrophobic neutrals (HON), and hydrophilic substances (HIS). The excitation emission matrix fluorescence spectra analysis showed that most aromatic protein and fulvic acid of the DOM with MW<1kDa were present in the HON and HIS fractions. The HON fraction was the dominant precursor to form THMs and HAAs, while HIS controlled the formation of HANs. Furthermore, bromo - DBPs dominated the total DBPs yields after the chlorination of HIS fraction.

[Formation of Brominated Disinfection By-products in Low Temperature Multi-effect Distillation (LT-MED) Process for Seawater Desalination].

Changes in water quality and brominated disinfection by-products (Br-DBPs) during a low temperature multi-effect distillation (LT-MED) process for seawater desalination were investigated. The concentrations of bromide ion and specific ultraviolet absorbance (SUVA) in the seawater (i.e. the influent of LT-MED) were 54.6 mg·L-1 and 1.7 L·(mg·m)-1, respectively. The tryptophan-like aromatic protein, fulvic acid-like and soluble microbial by-product-like organics dominated the fluorescent dissolved organic matter (DOM) in the seawater. After the NaClO pre-chlorination in the LT-MED process, the concentrations of DBPs in the seawater were significantly increased, especially Br-DBPs, and Bromoform(CHBr3) accounted for 100% of total trihalomethanes (THMs), Bromoacetic acid (C2H3BrO2) and dibromoacetic acid (C2H2Br2O2) accounted for 31.9% and 68.1%, respectively of total haloacetic acids (HAAs), while 4-Bromophenol (C6H5BrO) accounted for 100% of total halogenated phenols (HPs). The formation of THMs, HAAs and HPs was not detected in the finishing water produced by the LT-MED desalination process, but these substances were retained in the concentrated brine, of which THMs, HAAs and HPs were 56.9, 35.0 and 0.1 µg·L-1.

A comparative indirect ELISA for the detection of henipavirus antibodies based on a recombinant nucleocapsid protein expressed in Escherichia coli.

The indirect ELISA is a simple and useful method for detection of pathogen-specific antibodies in animal sera. However, non-specific or background binding is often a problem, especially when recombinant proteins from Escherichia coli are used. In this study, a comparative indirect ELISA in which the total reactivity and the background binding were determined simultaneously on the same ELISA plate was reported. The background was determined by incubation of the test sera with excess free antigen to block specific binding. The sample was considered positive only when its total reactivity reading was higher than a pre-determined cut-off value and the ratio of the total reactivity to the background reading was more than 2.0. Using this approach, an antibody assay for henipaviruses using a recombinant Nipah virus nucleocapsid protein expressed in E. coli was developed. A total of 919 negative serum samples were tested in this assay and the specificity was 95.8%. In addition, eight positive experimental serum samples all tested positive. The use of recombinant protein as the ELISA antigen, instead of inactivated virus antigens, will be of significant advantage for countries where there is no facility of Biosafety level 4 to handle this group of zoonotic viruses.

A stable and differentiable RNA positive control for reverse transcription-polymerase chain reaction.

Most RNA positive controls currently used for monitoring the quality of RT-PCR assays have some disadvantages, such as instability, inability to monitor the quality of the relevant primers and/or causing indifferentiable false positives. To avoid these disadvantages, a simple method to prepare stable and differentiable RNA positive controls is now demonstrated with a real-time RT-PCR assay for the detection of Nipah virus (NiV). A DNA sequence which was shorter than its counterpart in the NiV genome and contained the binding sites of the primers of the RT-PCR assay was designed, synthesized and inserted into a vector, and then amplified by PCR with two vector-specific primers both of which contained a T7 promoter at the 5' terminal. The RNA positive control was the dsRNA in vitro transcribed from the PCR amplicons flanked by two T7 promoters. The RNA positive control was stable and able to monitor the quality of the whole concerned RT-PCR assay. False positives caused by contaminations of the RNA positive control or its amplicons could be easily identified because the amplicons of the RNA positive control were obviously shorter than those of real positive samples. Thus, the RNA positive control reported in this study avoided some common disadvantages of current RNA positive controls.