[Show abstract][Hide abstract] ABSTRACT: DNA vaccines are simple to produce and can generate strong cellular and humoral immune response, making them attractive vaccine candidates. However, a major shortcoming of DNA vaccines is their poor immunogenicity when administered intramuscularly. Transcutaneous immunization (TCI) via microneedles is a promising alternative delivery route to enhance the vaccination efficacy. A novel dissolving microneedle array (DMA)-based TCI system loaded with cationic liposomes encapsulated with hepatitis B DNA vaccine and adjuvant CpG ODN was developed and characterized. The pGFP expression in mouse skin using DMA was imaged over time. In vivo immunity tests in mice were performed to observe the capability of DMA to induce immune response after delivery of DNA. The results showed that pGFP could be delivered into skin by DMA and expressed in skin. Further, the amount of expressed GFP was likely to peak at day 4. The immunity tests showed that the DMA-based DNA vaccination could induce effective immune response. CpG ODN significantly improved the immune response. The cationic liposomes could further improve the immunogenicity of DNA vaccine. In conclusion, the novel DMA-based TCI system can effectively deliver hepatitis B DNA vaccine into skin, and induce effective immune response.
Full-text · Article · Dec 2015 · Procedia in Vaccinology
[Show abstract][Hide abstract] ABSTRACT: Tick-borne encephalitis virus (TBEV) is a leading cause of human neurological infection in many parts of Europe and Asia. Although several TBEV isolates have been reported, current understanding of the biological characteristics of a Chinese strain is limited. In this study, a Far-Eastern strain of TBEV designated WH2012 was isolated in northern China. Its genome has been sequenced and found to be closely related to other Chinese TBEV isolates. Human cell lines of neural origin exposed to WH2012 showed cytopathic effects and WH2012 replicated most efficiently in human neuroblastoma cells SK-N-SH. In addition, WH2012 possessed a pathogenic potential in the mouse model, characterized by inducing a complete paralysis in the hindlimbs with a fatal outcome. We herein describe the first data regarding biological properties of TBEV from China. This study may help future research on pathogenic mechanisms of the neurological disease induced by TBEV infection in China.
[Show abstract][Hide abstract] ABSTRACT: Background:
We conducted a systematic review and meta-analysis to determine the association between serum lipid levels and suicidality, as evidence from previous studies has been inconsistent.
We identified relevant studies by searching Medline, Web of Science, EMBASE, and the Cochrane Database of Systematic Reviews (1980 to Dec. 5, 2014). Studies assessing the association between serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and/or triglycerides (TG) levels and suicidality were included. We used a random-effects model to take into account heterogeneity among studies.
We included 65 studies with a total of 510 392 participants in our analysis. Compared with the nonsuicidal patients, suicidal patients had significantly lower serum TC (weighted mean difference [WMD] -22.35, 95% confidence interval [CI] -27.95 to -16.75), LDL-C (WMD -19.56, 95% CI -26.13 to -12.99) and TG (WMD -23.40, 95% CI -32.38 to -14.42) levels, while compared with the healthy controls, suicidal patients had significantly lower TC (WMD -24.75, 95% CI -27.71 to -21.78), HDL-C (WMD -1.75, 95% CI -3.01 to -0.48) and LDL-C (WMD -3.85, 95% CI -7.45 to -0.26) levels. Furthermore, compared with the highest serum TC level category, a lower serum TC level was associated with a 112% (95% CI 40%-220%) higher risk of suicidality, including a 123% (95% CI 24%-302%) higher risk of suicide attempt and an 85% (95 CI 7%-221%) higher risk of suicide completion. The cut-off values for low and high serum TC level were in compliance with the categories reported in the original studies.
A major limitation of our study is the potential heterogeneity in most of the analyses. In addition, the suicidal behaviour was examined using different scales or methods across studies, which may further explain heterogeneity among the studies.
We identified an inverse association between serum lipid levels and suicidality. More mechanistic studies are needed to further explain this association.
Preview · Article · Oct 2015 · Journal of psychiatry & neuroscience: JPN
[Show abstract][Hide abstract] ABSTRACT: Studies that investigated the association between socio-economic position (SEP) and obesity in children suggest inconsistent results. The aim of this study is to summarize and quantify the current evidence on SEP and risks of overweight and obesity in children aged 0-15 years. Relevant studies published between 1990 to Sep 4, 2014 were searched in Medline, Web of Science, Embase, and the Cochrane Database of Systematic Reviews. Risk estimates from individual studies were pooled using random-effects models, according to lowest vs the highest SEP category. A total of 62 articles were included in the meta-analysis. The odds of both overweight risk and obesity risk were higher in the children with lowest SEP than in those with highest SEP (OR, 1.10, 95% CI: 1.03-1.17, and OR, 1.41, 95% CI: 1.29-1.55, respectively). Sub-group analyses showed that the inverse relationships between SEP and childhood overweight and obesity were only found in high-income countries and in more economic developed areas. In conclusion, our study suggests that children with lower SEP had higher risks of overweight and obesity, and the increased risks were independent of the income levels of countries.
[Show abstract][Hide abstract] ABSTRACT: Objective To develop an anti-hepatitis E virus (anti-HEV) IgG chemiluminescence assay kit and assess its clinical application. Methods The HEV recombinant antigen was used as coating antigen, horseradish peroxidase (HRP)-conjugated monoclonal anti-human IgG as the secondary antibody, and the luminol chemiluminescent reaction system as a substrate. The sensitivity, specificity, precision and other technical indicators of the kit were evaluated using the HEV national reference product, and a contrast experiment was conducted on 1012 serum samples by the kit developed in this research and a commercialized anti-HEV IgG chemiluminescence assay kit. Results The sensitivity, specificity, precision and stability of all the three batches of kit reached national standard. In the detection of 1012 clinical serum samples, the positive coincidence rate of both kits was 97.4%, the negative coincidence rate was 99.4%, and the total coincidence rate reached 98.4%. Conclusion An anti-HEV IgG chemiluminescence assay kit has been successfully developed. The kit is of high sensitivity and specificity, easy to operate. It is applicable to the clinical diagnosis and epidemiological survey of HEV infection.
No preview · Article · May 2015 · Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology
[Show abstract][Hide abstract] ABSTRACT: Unlabelled:
BACKGROUND AND RATIONALE FOR THE STUDY: To investigate thyroid function in patients with acute-on-chronic liver failure (ACLF) caused by hepatitis B virus infection and to determine whether thyroid hormone levels can be used as prognostic markers for assessing severity and prognosis of ACLF patients. We enrolled 75 patients with ACLF and70 patients with chronic hepatitis B (CHB). Continual serum samples were collected during hospitalization from the ACLF patients. The serum thyroid hormone levels (triiodothyronine [T3], thyroxine [T4], free (F)-T3, FT4, and thyroid stimulation hormone [TSH]) were measured by chemiluminescence. The Model for End-stage Liver Disease (MELD) score was used to assess severity.
ACLF patients showed significantly (p < 0.001) lower values of serum T3, T4, FT3/FT4 and TSH than CHB patients. The T3, T4, and TSH levels in ACLF patients were negatively correlated with the MELD score (T3: r = -0.495, p < 0.001; T4: r = -0.281, p < 0.001; TSH: r = -0.498, p < 0.001), suggesting that serum thyroid hormone levels reflect disease severity. At 1 year, 31 patients died. The T3 (p = 0.016), T4 (p = 0.008), and TSH (p = 0.003) levels in non-survivors were significantly lower than in survivors. The serum TSH level was a significant factor for predicting mortality in ACLF patients (optimal cutoff value = 0.38 IU/mL). The cumulative survival rate was decreased significantly when the serum TSH level was < 0.38 IU/mL (39.2%, p < 0.001).
Serum TSH level may be a useful indicator for assessing severity and prognosis in ACLF patients.
No preview · Article · Mar 2015 · Annals of hepatology: official journal of the Mexican Association of Hepatology
[Show abstract][Hide abstract] ABSTRACT: To understand the incidence and death patterns of viral hepatitis in China and provide evidence for the prevention and control of viral hepatitis.
The analysis was conducted on the incidence and death data of viral hepatitis published by National Health and Family Planning Commission during 2004-2013.
The incidences of viral hepatitis in Guizhou,Yunnan, Tibet, Gansu, Qinghai,Ningxia and Xinjiang provinces (autonomous region) were high. The major forms were hepatitis B (80.63/100 000) and hepatitis C (9.68/100 000), accounting for 80.90% and 9.25% of the total reported viral hepatitis cases respectively. The incidences of hepatitis A and unidentified hepatitis decreased and the incidence of hepatitis B, C and E increased during this period. During the 10 years, 10 008 deaths caused by viral hepatitis were reported (1 001 deaths per year). The reported deaths caused by hepatitis A, hepatitis E and unidentified hepatitis decreased during this period. The reported deaths caused by hepatitis B were in a downward trend, but the constituent in total cases remained high. The reported deaths caused by hepatitis C were in an upward trend.
During 2004-2013, the overall incidence of viral hepatitis showed no downward trend in China. The incidence of hepatitis B remained high, and the incidence of hepatitis C showed an obvious upward trend. The overall death rate and case fatality rate of viral hepatitis showed a downward trend, but hepatitis B remained the main cause of viral hepatitis related death, and the death caused by hepatitis C was in increase. Hepatitis B and hepatitis C are the major targets in the prevention and treatment of viral hepatitis in China, and the 7 western provinces (autonomous region) with high incidences are the key regions of the prevention and control.
No preview · Article · Feb 2015 · Zhonghua liu xing bing xue za zhi = Zhonghua liuxingbingxue zazhi
[Show abstract][Hide abstract] ABSTRACT: Abstract DNA vaccines are simple to produce and can generate strong cellular and humoral immune response, making them attractive vaccine candidates. However, a major shortcoming of DNA vaccines is their poor immunogenicity when administered intramuscularly. Transcutaneous immunization (TCI) via microneedles is a promising alternative delivery route to enhance the vaccination efficacy. A novel dissolving microneedle array (DMA)-based TCI system loaded with cationic liposomes encapsulated with hepatitis B DNA vaccine and adjuvant CpG ODN was developed and characterized. The pGFP expression in mouse skin using DMA was imaged over time. In vivo immunity tests in mice were performed to observe the capability of DMA to induce immune response after delivery of DNA. The results showed that pGFP could be delivered into skin by DMA and expressed in skin. Further, the amount of expressed GFP was likely to peak at day 4. The immunity tests showed that the DMA-based DNA vaccination could induce effective immune response. CpG ODN significantly improved the immune response and achieved the shift of immune type from predominate Th2 type to a balance Th1/Th2 type. The cationic liposomes could further improve the immunogenicity of DNA vaccine. In conclusion, the novel DMA-based TCI system can effectively deliver hepatitis B DNA vaccine into skin, inducing effective immune response and change the immune type by adjuvant CpG ODN.
[Show abstract][Hide abstract] ABSTRACT: We systematically reviewed the association of omega-3 fatty acids intake with the incidence of dementia and Alzheimer's disease (AD) in this meta-analysis of prospective cohort studies, as evidence from previous studies suggests inconsistent results.Methods
We identified relevant studies by searching PubMed, EmBase, and Web of Science databases up to June 2013. Prospective cohort studies reporting on associations of dietary intake of long-chain omega-3 fatty acids or fish with the incidence of dementia and AD were eligible.ResultsComparing the highest to lowest category of long-chain omega-3 fatty acids intake and fish intake, the pooled relative risks (RRs) for dementia were 0.97 (95% CI 0.85–1.10) and 0.84 (95% CI 0.71–1.01), respectively. Evidence synthesis for AD risk did not show a statistically significant association with long-chain omega-3 fatty acids intake (RR = 0.89, 95% CI 0.74–1.08). However, a higher intake of fish was associated with a 36% (95% CI 8–56%) lower risk of AD. Dose–response meta-analysis showed that an increment of 100 g per week of fish intake was associated with an 11% lower risk of AD (RR = 0.89, 95% CI 0.79–0.99). There was limited evidence of heterogeneity across studies or within subgroups.ConclusionA higher intake of fish was associated with a lower risk of AD. However, there was no statistical evidence for similar inverse association between long-chain omega-3 fatty acids intake and risk of dementia or AD, nor was there inverse association between fish intake and risk of dementia.
No preview · Article · Nov 2014 · Neuroscience & Biobehavioral Reviews
[Show abstract][Hide abstract] ABSTRACT: Our objective is to develop a rapid and sensitive assay based on magnetic beads to detect the concentration of influenza H3N2. The possibility of using variable domain heavy-chain antibodies (nanobody) as diagnostic tools for influenza H3N2 was investigated. A healthy camel was immunized with inactivated influenza H3N2. A nanobody library of 8 × 10(8) clones was constructed and phage displayed. After three successive biopanning steps, H3N2-specific nanobodies were successfully isolated, expressed in Escherichia coli, and purified. Sequence analysis of the nanobodies revealed that we possessed four classes of nanobodies against H3N2. Two nanobodies were further used to prepare our rapid diagnostic kit. Biotinylated nanobody was effectively immobilized onto the surface of streptavidin magnetic beads. The modified magnetic beads with nanobody capture specifically influenza H3N2 and can still be recognized by nanobodies conjugated to horseradish peroxidase (HRP) conjugates. Under optimized conditions, the present immunoassay exhibited a relatively high sensitive detection with a limit of 50 ng/mL. In conclusion, by combining magnetic beads with specific nanobodies, this assay provides a promising influenza detection assay to develop a potential rapid, sensitive, and low-cost diagnostic tool to screen for influenza infections.
Preview · Article · Sep 2014 · Nanoscale Research Letters
[Show abstract][Hide abstract] ABSTRACT: SUMMARY To evaluate the presence of a new type of reovirus (designated R4) in humans, we determined the prevalence of specific antibodies using a neutralization assay and ELISA. The sera from 97 healthy people and 219 patients in our hospital with measles, hand-foot-and-mouth disease, liver diseases, and diarrhoea were investigated. Although the study population was limited, our data suggested that R4 is widespread in the human population. A significantly higher level of R4-specific antibody in patients than in healthy people is worthy of consideration, since it poses a risk for aggravation of the extant illness by the reovirus.
No preview · Article · Dec 2013 · Epidemiology and Infection
[Show abstract][Hide abstract] ABSTRACT: In this study, we investigated humoral and cellular immune responses in mice to DNA vaccines containing individual S or M genes of a new type of reovirus (nRV) isolate from a severe acute respiratory syndrome (SARS) patient in Beijing, China. Mice were immunized intramuscularly (i.m.) with 100 μg of S1, S2, S3, S4, M1, M2, and M3 DNA vaccine each 4 times in 2-week intervals and assayed for humoral IgG, IgG1, IgG2, and IgG2b antibodies by ELISA and for cellular immune response, particularly IFN-γ induction by ELISpot assay. Moreover, CD4+ and CD8+ T cell levels in peripheral blood mononuclear cells were assayed by flow cytometry. We found that all DNA vaccines induced IgG antibodies, predominantly of the IgG2a class and S3 DNA vaccine was the strongest inducer. M2 and S3 DNA vaccines elicited Th1- and Th2-based immune responses, respectively, while S1 and M3 DNA vaccines induced a mixed Th1/Th2 response. M1, S2, and S4 DNA vaccines were poorly immunogenic. To our knowledge, this is the first report characterizing mammalian reovirus DNA vaccines applied to a mouse model. Keywords: reovirus; DNA vaccine; SARS; mouse; immunogenicity.
[Show abstract][Hide abstract] ABSTRACT: Enteroviruses can frequently target the human central nervous system to induce a variety of neurological diseases. Although enteroviruses are highly cytolytic, emerging evidence has showed that these viruses can establish persistent infections both in vivo and in vitro. Here, we investigated the susceptibility of three human brain cell lines CCF-STTG1, T98G and SK-N-SH to the infection of three enterovirus serotypes Coxsackievirus B3 (CVB3), Enterovirus 71 and Coxsackievirus A9. Persistent infection was observed in CVB3 infected CCF-STTG1 as evidenced by prolonged detection of infectious virions, viral RNA, and viral antigens. Of note, infected CCF-STTG1 cells expressed non-functional canonical viral receptors, coxsackievirus-adenovirus receptor and decay-accelerating factor, while removal of cell surface chondroitin sulfate from CCF-STTG1 inhibited the replication of CVB3, suggesting that receptor usage was one of the major limiting factors in CVB3 persistence. In addition, CVB3 curtailed the induction of IFN-β in infected CCF-STTG1 cells, which likely contributed to the initiation of persistence. Furthermore, proinflammatory chemokines and cytokines such as VCAM-1, IL-8 and IL-6, were up-regulated in CVB3 infected CCF-STTG1 and human progenitor-derived astrocytes. Our data together demonstrate the potential of CCF-STTG1 as a novel cell model for studying CVB3-CNS interactions, providing the basis toward a better understanding of CVB3-induced chronic neuropathogenesis.
Full-text · Article · Sep 2013 · Journal of Virology
[Show abstract][Hide abstract] ABSTRACT: Vibrio parahaemolyticus AphA and OpaR are the two master quorum sensing (QS) regulators that are abundantly expressed at low cell density (LCD) and high cell density (HCD), respectively, with a feature of reciprocally gradient production of them with transition between LCD and HCD. The type VI secretion system 2 (T6SS2) gene cluster can be assigned into three putative operons, namely VPA1027-1024, VPA1043-1028, and VPA1044-1046. T6SS2 contributes to adhesion of V. parahaemolyticus to host cells.
OpaR box-like sequences were found within the upstream promoter regions of all the above three operons, while none of AphA box-like elements could be identified for them. The subsequent primer extension, LacZ fusion, electrophoretic mobility shift, and DNase I footprinting assays disclosed that OpaR bound to the promoter regions of these three operons to stimulate their transcription, while AphA negatively regulated their transcription most likely through acting on OpaR. This regulation led to a gradient increase of T6SS2 transcription with transition from LCD to HCD.
V. parahaemolyticus OpaR and AphA positively and negatively regulate T6SS2 expression, respectively, leading to a gradient elevation of T6SS2 expression with transition from LCD to HCD. T6SS2 genes are thus assigned as the QS regulon members in V. parahaemolyticus.
[Show abstract][Hide abstract] ABSTRACT: Vibrio parahaemolyticus AphA and OpaR are the two master regulators of quorum sensing (QS) that are abundantly produced and operate at low cell density (LCD) and high cell density (HCD), respectively, with an outcome of reciprocally gradient production of these two proteins with transition between LCD and HCD. The cpsQ-mfpABC gene cluster is transcribed as two operons cpsQ-mfpABC and mfpABC in V. parahaemolyticus. MfpABC is a putative membrane fusion transporter that contributes to biofilm development. CpsQ is a c-di-GMP-binding regulator that activates the expression of capsular polysaccharide genes and mfpABC and, thus, induces biofilm development. As shown in this study, OpaR and AphA bind to the promoter region of mfpABC to enhance and repress its transcription, respectively. In contrast, the positive and negative regulation of cpsQ-mfpABC by AphA and OpaR, respectively, achieves probably through acting of AphA or OpaR on additional unknown regulator(s) of cpsQ-mfpABC. The transcriptional levels of cpsQ-mfpABC and mfpABC enhance gradually with transition from LCD to HCD due to the above reciprocal regulatory action of OpaR and AphA. Data presented here present a novel paradigm of combined action of the two master QS regulators in controlling expression of the QS regulon members.
No preview · Article · Jul 2013 · International journal of food microbiology
[Show abstract][Hide abstract] ABSTRACT: Infections with bacterial or fungal biofilms have emerged as a major public heath concern because biofilm-growing cells are highly resistant to both antibiotics and host immune defenses. This review focuses on the progress in understanding the mechanisms of biofilm-specific antimicrobial resistance and in developing innovative therapeutic measures based on novel antibiofilm agents.
No preview · Article · Jul 2013 · Future Microbiology