140 research outputs found
A Compound Fuzzy Disturbance Observer Based on Sliding Modes and Its Application on Flight Simulator
A compound fuzzy disturbance observer based on sliding modes is developed, and its application on flight simulator is presented. Fuzzy disturbance observer (FDO) is an effective method in nonlinear control. However, traditional FDO is confined to monitor dynamic disturbance, and the frequency bandwidth of the system is restricted. Sliding mode control (SMC) compensates the high-frequency component of disturbance while it is limited by the chattering phenomenon. The proposed method uses the sliding mode technique to deal with the uncompensated dynamic equivalent disturbance. The switching gain of sliding mode control designed according to the error of disturbance estimation is a small value. Therefore, the proposal also helps to decrease the chattering. The validity of the proposal method is confirmed by experiments on flight simulator
Antibodies from women urogenitally infected with C. trachomatis predominantly recognized the plasmid protein pgp3 in a conformation-dependent manner
<p>Abstract</p> <p>Background</p> <p><it>C. trachomatis </it>organisms carry a cryptic plasmid that encodes 8 open reading frames designated as pORF1 to 8. It is not clear whether all 8 pORFs are expressed during <it>C. trachomatis </it>infection in humans and information on the functionality of the plasmid proteins is also very limited.</p> <p>Results</p> <p>When antibodies from women urogenitally infected with <it>C. trachomatis </it>were reacted with the plasmid proteins, all 8 pORFs were positively recognized by one or more human antibody samples with the recognition of pORF5 protein (known as pgp3) by most antibodies and with the highest titers. The antibody recognition of the pORFs was blocked by <it>C. trachomatis</it>-infected HeLa but not normal HeLa cell lysates. The pgp3 fusion protein-purified human IgG detected the endogenous pgp3 in the cytosol of <it>C. trachomatis</it>-infected cells with an intracellular distribution pattern similar to that of CPAF, a chlamydial genome-encoded protease factor. However, the human antibodies no longer recognized pgp3 but maintained recognition of CPAF when both antigens were linearized or heat-denatured. The pgp3 conformation is likely maintained by the C-terminal 75% amino acid sequence since further deletion blocked the binding by the human antibodies and two conformation-dependent mouse monoclonal antibodies.</p> <p>Conclusion</p> <p>The plasmid-encoded 8 proteins are both expressed and immunogenic with pgp3 as the most immunodominant antigen during chlamydial infection in humans. More importantly, the human anti-pgp3 antibodies are highly conformation-dependent. These observations have provided important information for further understanding the function of the plasmid-encoded proteins and exploring the utility of pgp3 in chlamydial diagnosis and vaccination.</p
Increasing a Robust Antigen-Specific Cytotoxic T Lymphocyte Response by FMDV DNA Vaccination with IL-9 Expressing Construct
Various chemokines and cytokines as adjuvants can be used to improve efficacy of DNA vaccination. In this study, we sought to investigate if a DNA construct expressing IL-9 (designed as proV-IL9) as a molecular adjuvant enhance antigen specific immune responses elicited by the pcD-VP1 DNA vaccination. Mice immunized with pcD-VP1 combined with proV-IL9 developed a strong humoral response. In addition, the coinoculation induced significant higher level of antigen-specific cell proliferation and cytotoxic response. This agreed well with higher expression level of IFN-Ξ³ and perforin in CD8+ T cells, but not with IL-17 in these T cells. The results indicate that IL-9 induces the development of IFN-Ξ³-producing CD8+ T cells (Tc1), but not the IL-17-producing CD8+ T cells (Tc17). Up-regulated expressions of BCL-2 and BCL-XL were exhibited in these Tc1 cells, suggesting that IL-9 may trigger antiapoptosis mechanism in these cells. Together, these results demonstrated that IL-9 used as molecular adjuvant could enhance the immunogenicity of DNA vaccination, in augmenting humoral and cellular responses and particularly promoting Tc1 activations. Thus, the IL-9 may be utilized as a potent Tc1 adjuvant for DNA vaccines
Use of Praziquantel as an Adjuvant Enhances Protection and Tc-17 Responses to Killed H5N1 Virus Vaccine in Mice
BACKGROUND: H5N1 is a highly pathogenic influenza A virus, which can cause severe illness or even death in humans. Although the widely used killed vaccines are able to provide some protection against infection via neutralizing antibodies, cytotoxic T-lymphocyte responses that are thought to eradicate viral infections are lacking. METHODOLOGY/PRINCIPAL FINDINGS: Aiming to promote cytotoxic responses against H5N1 infection, we extended our previous finding that praziquantel (PZQ) can act as an adjuvant to induce IL-17-producing CD8(+) T cells (Tc17). We found that a single immunization of 57BL/6 mice with killed viral vaccine plus PZQ induced antigen-specific Tc17 cells, some of which also secreted IFN-Ξ³. The induced Tc17 had cytolytic activities. Induction of these cells was impaired in CD8 knockout (KO) or IFN-Ξ³ KO mice, and was even lower in IL-17 KO mice. Importantly, the inoculation of killed vaccine with PZQ significantly reduced virus loads in the lung tissues and prolonged survival. Protection against H5N1 virus infection was obtained by adoptively transferring PZQ-primed wild type CD8(+) T cells and this was more effective than transfer of activated IFN-Ξ³ KO or IL-17 KO CD8(+) T cells. CONCLUSIONS/SIGNIFICANCE: Our results demonstrated that adding PZQ to killed H5N1 vaccine could promote broad Tc17-mediated cytotoxic T lymphocyte activity, resulting in improved control of highly pathogenic avian influenza virus infection
Praziquantel Facilitates IFN-Ξ³-Producing CD8+ T Cells (Tc1) and IL-17-Producing CD8+ T Cells (Tc17) Responses to DNA Vaccination in Mice
BACKGROUND: CD8(+) cytotoxic T lymphocytes (CTLs) are crucial for eliminating hepatitis B virus (HBV) infected cells. DNA vaccination, a novel therapeutic strategy for chronic virus infection, has been shown to induce CTL responses. However, accumulated data have shown that CTLs could not be effectively induced by HBV DNA vaccination. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that praziquantel (PZQ), an anti-schistoma drug, could act as an adjuvant to overcome the lack of potent CTL responses by HBV DNA vaccination in mice. PZQ in combination with HBV DNA vaccination augmented the induction of CD8(+) T cell-dependent and HBV-specific delayed hypersensitivity responses (DTH) in C57BL/6 mice. Furthermore, the induced CD8(+) T cells consisted of both Tc1 and Tc17 subtypes. By using IFN-Ξ³ knockout (KO) mice and IL-17 KO mice, both cytokines were found to be involved in the DTH. The relevance of these findings to HBV immunization was established in HBsAg transgenic mice, in which PZQ also augmented the induction of HBV-specific Tc1 and Tc17 cells and resulted in reduction of HBsAg positive hepatocytes. Adoptive transfer experiments further showed that PZQ-primed CD8(+) T cells from wild type mice, but not the counterpart from IFN-Ξ³ KO or IL-17 KO mice, resulted in elimination of HBsAg positive hepatocytes. CONCLUSIONS/SIGNIFICANCE: Our results suggest that PZQ is an effective adjuvant to facilitate Tc1 and Tc17 responses to HBV DNA vaccination, inducing broad CD8(+) T cell-based immunotherapy that breaks tolerance to HBsAg
Association between triglyceride glucose index and breast cancer in 142,184 Chinese adults: findings from the REACTION study
BackgroundThe triglyceride glucose (TyG) index has been associated with an increased risk in breast cancer. However, this association remains unclear among the Chinese population. This study aimed to investigate whether the TyG index is associated with the risk of prevalent breast cancer in Chinese women.MethodsThis cross-sectional study included 142,184 women from the REACTION (Risk Evaluation of Cancers in Chinese Diabetic Individuals: A Longitudinal) Study, which recruited adults aged 40 years or older from 25 centers across mainland China between 2011 and 2012. The TyG index was calculated according to the formula: Ln (fasting triglycerides [mg/dL] Γ fasting glucose [mg/dL]/2). Multivariable-adjusted logistic regression models were used to evaluate odds ratios (ORs) and 95% confidence intervals (CIs) regarding the associations between the TyG index and breast cancer.ResultsMultivariable-adjusted logistic regression analysis showed that compared with the lowest quartile of the TyG index, the highest quartile of the TyG index was significantly associated with an increased risk of prevalent breast cancer, with an OR (95% CI) of 1.61 (1.19β2.17). In the stratified analysis, the association of each 1 SD increase in the TyG index with risk of prevalent breast cancer was more dominant in individuals with menarche at age 13β17, those who were postmenopausal, those with a history of breastfeeding, and those who had two to four children, with the ORs (95% CIs) of 1.35 (1.09β1.68), 1.27 (1.05β1.54), 1.26 (1.05β1.52), and 1.32 (1.08β1.62), respectively. Moreover, among those without discernible insulin resistance (homeostatic model assessment-insulin resistance [HOMA-IR] β₯2.5), hyperglycemia and dyslipidemia, each 1 SD increase in the TyG index was associated with a 1.36-fold increase in breast cancer risk, with an OR (95% CI) of 2.36 (1.44β3.87).ConclusionThe TyG index is significantly associated with the prevalent breast cancer risk among middle-aged and elderly Chinese women
Modification effect of changes in cardiometabolic traits in association between kidney stones and cardiovascular events
BackgroundsWhether longitudinal changes in metabolic status influence the effect of kidney stones on cardiovascular disease (CVD) remains unclarified. We investigated the modification effect of status changes in metabolic syndrome (MetS) in the association of kidney stones with risk of incident CVD events.MethodsWe performed a prospective association and interaction study in a nationwide cohort including 129,172 participants aged β₯ 40 years without CVDs at baseline and followed up for an average of 3.8 years. Kidney stones information was collected by using a questionnaire and validated by medical records. The repeated biochemical measurements were performed to ascertain the metabolic status at both baseline and follow-up.Results4,017 incident total CVDs, 1,413 coronary heart diseases (CHDs) and 2,682 strokes were documented and ascertained during follow-up. Kidney stones presence was significantly associated with 44%, 70% and 31% higher risk of CVDs, CHDs and stroke, respectively. The stratified analysis showed significant associations were found in the incident and sustained MetS patients, while no significant associations were found in the non-MetS at both baseline and follow-up subjects or the MetS remission ones, especially in women. For the change status of each single component of the MetS, though the trends were not always the same, the associations with CVD were consistently significant in those with sustained metabolic disorders, except for the sustained high blood glucose group, while the associations were consistently significant in those with incident metabolic disorders except for the incident blood pressure group. We also found a significant association of kidney stone and CVD or CHD risk in the remain normal glucose or triglycerides groups; while the associations were consistently significant in those with incident metabolic disorders except for the incident blood pressure group. We also found a significant association of kidney stone and CVD or CHD risk in the remain normal glucose or triglycerides groups.ConclusionsA history of kidney stones in women with newly developed MetS or long-standing MetS associated with increased risk of CVD. The mechanisms link kidney stones and CVD risk in the metabolic and non-metabolic pathways were warranted for further studies
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