Discovery of FO-4-15, a novel 1,2,4-oxadiazole derivative, ameliorates cognitive impairments in 3×Tg mice by activating the mGluR1/CaMKIIα pathway.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder characterized by cognitive impairments. Despite the limited efficacy of current treatments for AD, the 1,2,4-oxadiazole structure has garnered significant attention in medicinal chemistry due to its potential impact on mGluR1 and its association with AD therapy. In this study, a series of novel 1,2,4-oxadiazole derivatives were designed, synthesized, and evaluated for the neuroprotective effects in human neuroblastoma (SH-SY5Y) cells. Among all the derivatives tested, FO-4-15 (5f) existed the lowest cytotoxicity and the highest protective effect against H2O2. Based on these in vitro results, FO-4-15 was administered to 3×Tg mice and significantly improved the cognitive impairments of the AD mice. Pathological analysis showed that FO-4-15 significantly reduced Aß accumulation, Tau hyper-phosphorylation, and synaptic impairments in the 3×Tg mice. Dysfunction of the CaMKIIα/Fos signaling pathway in 3×Tg mice was found to be restored by FO-4-15 and the necessity of the CaMKIIα/Fos for FO-4-15 was subsequently confirmed by the use of a CaMKIIα inhibitor in vitro. Beyond that, mGluR1 was identified to be a potential target of FO-4-15, and the interaction of FO-4-15 and mGluR1 was displayed by Ca2+ flow increase, molecular docking, and interaction energy analysis. The target of FO-4-15 was further confirmed in vitro by JNJ16259685, a nonselective inhibitor of mGluR1. These findings suggest that FO-4-15 may hold promise as a potential treatment for Alzheimer's disease.

SARS-CoV-2 nucleocapsid protein enhances the level of mitochondrial reactive oxygen species.

Coronavirus disease 2019 (COVID-19) pathogenesis is influenced by reactive oxygen species (ROS). Nevertheless, the precise mechanisms implicated remain poorly understood. The nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the main driver for this condition, is a structural protein indispensable for viral replication and assembly, and its role in ROS production has not been reported. This study shows that SARS-CoV-2 N protein expression enhances mitochondrial ROS level. Bulk RNA-sequencing suggests of aberrant redox state of the electron transport chain. Accordingly, this protein hinders ATP production but simultaneously augments the activity of complexes I and III, and most mitochondrially encoded complex I and III proteins are upregulated by it. Mechanistically, N protein of SARS-CoV-2 shows significant mitochondrial localization. It interacts with mitochondrial transcription components and stabilizes them. Moreover, it also impairs the activity of antioxidant enzymes with or without detectable interaction.

FAT10 Silencing Prevents Liver Fibrosis through Regulating SIRT1 Expression in Hepatic Stellate Cells.

Background and objectives: Hepatic stellate cell (HSC) activation is the cardinal factor due to the accumulation of extracellular matrix proteins during the development of liver fibrosis. The aim of the present study was to find new targets for developing drugs to treat liver fibrosis, by screening the key genes involved in the activation of hepatic stellate cells. Methods: Differentially expressed genes were identified through TCGA database. RT-PCR, immunohistochemistry (IHC) assay, western blot, and ELISA were performed to evaluate the expression levels of FAT10 and fibrotic molecules. In vitro experiments were conducted to investigate the signaling pathways and biological functions of FAT10 in LX-2 cell lines. Results: In the present study, expression profiles obtained from the Gene Expression Omnibus (GEO) were used to explore the different genes expression between HSCs treated with or without carbon tetrachloride (CCl4). Human leukocyte antigen (HLA)-F adjacent transcript 10 (FAT10) was selected for further investigations. In animal model of carbon tetrachloride-induced liver fibrosis, the expression of FAT10 on activated HSCs is upregulated. In vitro, silencing FAT10 reduced TGF-ß1-induced ECM activation and accumulation in LX-2 cells, and also suppressed the inflammatory response of LX-2 cells. Further Transwell results suggested that knockdown of FAT10 could inhibit TGF-ß1-induced LX-2 cell migration and invasion. Mechanistically, FAT10 promotes its fibrotic activity through regulating sirtuin 1 (SIRT1), with a concomitant activation of ECM. Conclusions: These findings indicated an unexpected role of FAT10 in liver fibrosis development, suggesting that silencing FAT10 might represent a new strategy for the treatment of fibrotic liver diseases.

Evaluation of Roadside LiDAR-Based and Vision-Based Multi-Model All-Traffic Trajectory Data.

Trajectory data has gained increasing attention in the transportation industry due to its capability of providing valuable spatiotemporal information. Recent advancements have introduced a new type of multi-model all-traffic trajectory data which provides high-frequency trajectories of various road users, including vehicles, pedestrians, and bicyclists. This data offers enhanced accuracy, higher frequency, and full detection penetration, making it ideal for microscopic traffic analysis. In this study, we compare and evaluate trajectory data collected from two prevalent roadside sensors: LiDAR and camera (computer vision). The comparison is conducted at the same intersection and over the same time period. Our findings reveal that current LiDAR-based trajectory data exhibits a broader detection range and is less affected by poor lighting conditions compared to computer vision-based data. Both sensors demonstrate acceptable performance for volume counting during daylight hours, but LiDAR-based data maintains more consistent accuracy at night, particularly in pedestrian counting. Furthermore, our analysis demonstrates that, after applying smoothing techniques, both LiDAR and computer vision systems accurately measure vehicle speeds, while vision-based data show greater fluctuations in pedestrian speed measurements. Overall, this study provides insights into the advantages and disadvantages of LiDAR-based and computer vision-based trajectory data, serving as a valuable reference for researchers, engineers, and other trajectory data users in selecting the most appropriate sensor for their specific needs.

Abelson tyrosine kinase controls BCR signalling and B-cell differentiation by promoting B-cell metabolism.

As a nonreceptor tyrosine kinase, Abelson tyrosine kinase (c-Abl) was first studied in chronic myelogenous leukaemia, and its role in lymphocytes has been well characterised. c-Abl is involved in B-cell development and CD19-associated B-cell antigen receptor (BCR) signalling. Although c-Abl regulates different metabolic pathways, the role of c-Abl is still unknown in B-cell metabolism. In this study, B-cell-specific c-Abl knockout (KO) mice (Mb1Cre+/- c-Ablfl/fl ) were used to investigate how c-Abl regulates B-cell metabolism and BCR signalling. We found that the levels of activation positive BCR signalling proximal molecules, phosphorylated spleen tyrosine kinase (pSYK) and phosphorylated Bruton tyrosine kinase (pBTK), were decreased, while the level of key negative regulator, phosphorylated SH2-containing inositol phosphatase 1 (pSHIP1), was increased in Mb1Cre+/- c-Ablfl/fl mice. Furthermore, we found c-Abl deficiency weakened the B-cell spreading, formation of BCR signalosomes, and the polymerisation of actin during BCR activation, and also impaired the differentiation of germinal center (GC) B-cells both in quiescent condition and after immunisation. Moreover, B-cell mitochondrial respiration and the expression of B-cell metabolism-regulating molecules were downregulated in c-Abl deficiency mice. Overall, c-Abl, which involved in actin remodelling and B-cell metabolism, positively regulates BCR signalling and promotes GC differentiation.

Cepharanthine sensitizes human triple negative breast cancer cells to chemotherapeutic agent epirubicin via inducing cofilin oxidation-mediated mitochondrial fission and apoptosis.

Inhibition of autophagy has been accepted as a promising therapeutic strategy in cancer, but its clinical application is hindered by lack of effective and specific autophagy inhibitors. We previously identified cepharanthine (CEP) as a novel autophagy inhibitor, which inhibited autophagy/mitophagy through blockage of autophagosome-lysosome fusion in human breast cancer cells. In this study we investigated whether and how inhibition of autophagy/mitophagy by cepharanthine affected the efficacy of chemotherapeutic agent epirubicin in triple negative breast cancer (TNBC) cells in vitro and in vivo. In human breast cancer MDA-MB-231 and BT549 cells, application of CEP (2 µM) greatly enhanced cepharanthine-induced inhibition on cell viability and colony formation. CEP interacted with epirubicin synergistically to induce apoptosis in TNBC cells via the mitochondrial pathway. We demonstrated that co-administration of CEP and epirubicin induced mitochondrial fission in MDA-MB-231 cells, and the production of mitochondrial superoxide was correlated with mitochondrial fission and apoptosis induced by the combination. Moreover, we revealed that co-administration of CEP and epirubicin markedly increased the generation of mitochondrial superoxide, resulting in oxidation of the actin-remodeling protein cofilin, which promoted formation of an intramolecular disulfide bridge between Cys39 and Cys80 as well as Ser3 dephosphorylation, leading to mitochondria translocation of cofilin, thus causing mitochondrial fission and apoptosis. Finally, in mice bearing MDA-MB-231 cell xenografts, co-administration of CEP (12 mg/kg, ip, once every other day for 36 days) greatly enhanced the therapeutic efficacy of epirubicin (2 mg/kg) as compared with administration of either drug alone. Taken together, our results implicate that a combination of cepharanthine with chemotherapeutic agents could represent a novel therapeutic strategy for the treatment of breast cancer.

Purinergic P2X7 Receptor Mediates the Elimination of Trichinella spiralis by Activating NF-κB/NLRP3/IL-1ß Pathway in Macrophages.

Trichinellosis is one of most neglected foodborne zoonoses worldwide. During Trichinella spiralis infection, the intestinal immune response is the first line of defense and plays a vital role in the host's resistance. Previous studies indicate that purinergic P2X7 receptor (P2X7R) and pyrin domain-containing protein 3 (NLRP3) inflammasome are involved in the intestinal immune response in T. spiralis infection. However, the precise role of P2X7R and its effect on NLRP3 remains largely underdetermined. In this study, we aimed to investigate the role of P2X7R in the activation of NLRP3 in macrophages during the intestinal immune response against T. spiralis We found that T. spiralis infection upregulated expression of P2X7R and activation of NLRP3 in macrophages in mice. In vivo, P2X7R deficiency resulted in increased intestinal adult and muscle larval burdens, along with decreased expression of NLRP3/interleukin-1ß (IL-1ß) in macrophages from the infected mice with T. spiralis In In vitro experiments, P2X7R blockade inhibited activation of NLRP3/IL-1ß via NF-κB and thus reduced the capacity of macrophages to kill newborn larvae of T. spiralis These results indicate that P2X7R mediates the elimination of T. spiralis by activating the NF-κB/NLRP3/IL-1ß pathway in macrophages. Our findings contribute to the understanding of the intestinal immune mechanism of T. spiralis infection.

Exosomes from activated hepatic stellate cells contain GLUT1 and PKM2: a role for exosomes in metabolic switch of liver nonparenchymal cells.

The mechanism of exosomes derived from activated hepatic stellate cells (HSCs) involved in liver fibrosis is poorly understood. We previously reported that hypoxia-inducible factor 1 (Hif-1) regulated HSC activation, and, therefore, we investigated in current work whether Hif-1 regulates exosome secretion and the metabolic switch of HSCs, thus affecting the metabolism of liver nonparenchymal cells. In this study, the characteristics of exosomes from HSCs were assessed via electron microscopy, Western blot analysis, and acetylcholinesterase activity. Confocal microscopy was used to measure the uptake of exosomes by quiescent HSCs, Kupffer cells (KCs), and liver sinusoidal endothelial cells (LSECs). Hif-1α was inhibited via 2-ME or specific small interfering RNAs to investigate its role in exosomes derived from HSCs. It was determined that glucose transporter 1 and pyruvate kinase M2 were increasingly expressed in fibrotic liver samples, cell lysates, and exosomes derived from activated HSCs. Exosomes released from HSCs were associated with activation and glucose uptake of HSCs. Delivery of exosomes from activated HSCs induced glycolysis of quiescent HSCs, KCs, and LSECs. Disruption of Hif-1 expression suppressed the glycolysis effect delivered by exosomes. Conclusively, our results demonstrated that exosomes secreted by activated HSCs affect the metabolic switch of liver nonparenchymal cells via delivery of glycolysis-related proteins. These findings represent a novel mechanism that contributes to liver fibrosis and has significant implications for new diagnosis and treatment of liver diseases.-Wan, L., Xia, T., Du, Y., Liu, J., Xie, Y., Zhang, Y., Guan, F., Wu, J., Wang, X., Shi, C. Exosomes from activated hepatic stellate cells contain GLUT1 and PKM2: a role for exosomes in metabolic switch of liver nonparenchymal cells.

ApoE deficiency promotes hepatic pathology by aggravating Th17/Treg imbalance in murine schistosomiasis japonica.

AIMS: The Schistosoma japonicum (S japonicum)-infected ApoE gene deficiency (ApoE-/- ) mice were used to determine effect of ApoE on hepatic immunopathology. METHODS: Murine activities and appetite, body weight, and ratio of liver weight to its body weight (Hepatic mass index, HMI) were observed. Worm load and liver egg burden were evaluated as the infection intensity. Number and size of liver egg granulomas and serum levels of alanine aminotransferase (ALT) were investigated. We analysed hepatic fibrosis by markers of fibrosis in tissue, detected hepatic Th17 and Treg frequency by flow cytometry, and measured hepatic expressions of RORγt, Foxp3, IL-17A and TGF-ß1 via qPCR. Lipid metabolism was determined by serum levels of cholesterol (TC) and triglyceride (TG) as well as hepatic Oil red O staining. RESULTS: In the infected ApoE-/- mice, the increased infection intensity aggravated the hepatic immunopathology (evidenced by increased HMI, elevated egg granulomas and increased ALT levels) and fibrosis (increased hepatic collagen deposition). ApoE deficiency resulted in significantly elevated ratio of hepatic Th17/Treg and higher serum levels of TC and TG, along with higher level of hepatic Oil red O staining. CONCLUSIONS: ApoE deficiency promotes hepatic pathology and fibrosis by exacerbating Th17/Treg imbalance and altering lipid metabolism in murine schistosomiasis japonica.

Transparency and AIE tunable supramolecular polymer hydrogel acts as TEA-HCl vapor controlled smart optical material.

Stimuli-responsive optical materials attract lots of attention due to their broad applications. Herein, a novel smart stimuli-responsive supramolecular polymer was successfully constructed using a simple tripodal quaternary ammonium-based gelator (TH). The TH self-assembles into a supramolecular polymer hydrogel (TH-G) and shows aggregation-induced emission (AIE) properties. Interestingly, the transparency and fluorescence of the TH-G xerogel film (TH-GF) could be reversibly regulated by use of triethylamine (TEA) and hydrochloric acid (HCl) vapor. When alternately fumed with TEA and HCl vapor, the optical transmittance of the TH-GF was changed from 8.9% to 92.7%. Meanwhile, the fluorescence of the TH-G shows an "ON/OFF" switch. The reversible switching of the transparency and the fluorescence of the TH-GF is attributed to the assembly and disassembly of the supramolecular polymer TH-G. Based on these stimuli-response properties, the TH-GF could act as an optical material and shows potential applications as smart windows or fluorescent display material controlled by TEA and HCl vapor.

Co-infection of malaria and HIV infection in severely undernourished children in the Democratic Republic of the Congo: a cross-sectional study.

PURPOSE: This study aims to determine the prevalence of malaria and HIV seropositivity among children with undernutrition in the Democratic Republic of the Congo. METHODS: A cross-sectional study of undernourished children aged between 12 and 60 months in Kalembe-Lembe hospital was carried out. Blood samples were collected for the analyses of malaria parasite, haemoglobin and haematocrit levels. HIV serostatus was determined with rapid HIV antibody tests and enzyme-linked immunosorbent assay. Logistic regression analyses were used to identify clinical predictors of HIV seropositivity. RESULTS: Of 225 children, 88.9% had malaria; the parasite loads were 16 000 para per µL (38.0%); 24 400 para per µL (56.8%), P < 0.001 and malaria and associated HIV infection accounted for 29.2%. In children aged >12 months, HIV seroprevalence was 29.3%; 86.0% had undernutrition and malaria, 6.8% had undernutrition and HIV and 4.3% had undernutrition, HIV and malaria (P < 0.001). The occurrence of at least three or more symptoms was highly specific (96.4-100.0%) for HIV seropositivity (P < 0.05). The overall mortality rate was 18.4%, higher in children with malaria and HIV (39.6% vs 12.2%, P < 0.001) and those with lower weight gain (4.3 vs 7.5 g kg-1 day-1, P < 0.001). CONCLUSIONS: There was high prevalence of malaria and HIV and mortality among severely undernourished children with malaria and HIV.

A Comprehensive Evaluation Method of Sensor Selection for PHM Based on Grey Clustering.

Sensor selection plays an essential and fundamental role in prognostics and health management technology, and it is closely related to fault diagnosis, life prediction, and health assessment. The existing methods of sensor selection do not have an evaluation standard, which leads to different selection results. It is not helpful for the selection and layout of sensors. This paper proposes a comprehensive evaluation method of sensor selection for prognostics and health management (PHM) based on grey clustering. The described approach divides sensors into three grey classes, and defines and quantifies three grey indexes based on a dependency matrix. After a brief introduction to the whitening weight function, we propose a combination weight considering the objective data and subjective tendency to improve the effectiveness of the selection result. Finally, the clustering result of sensors is obtained by analyzing the clustering coefficient, which is calculated based on the grey clustering theory. The proposed approach is illustrated by an electronic control system, in which the effectiveness of different methods of sensor selection is compared. The result shows that the technique can give a convincing analysis result by evaluating the selection results of different methods, and is also very helpful for adjusting sensors to provide a more precise result. This approach can be utilized in sensor selection and evaluation for prognostics and health management.

Prelamin A overexpression promotes detrusor calcification/aging in urinary incontinence via prelamin A accumulation.

Urinary incontinence (UI) is known as a distressing condition particularly among older adults, and negatively associated with health-related quality of life in both males and females. Prelamin A accumulation has been found in all progeroid laminopathies and is obviously linked to cell and organism aging. Therefore, this study was expected to investigate the effect of prelamin A on detrusor on UI. Prelamin A expression in clinical and animal samples was detected. To investigate the degree of prelamin A accumulation and detrusor calcification/aging, the detrusor cells were subcultured separately into low and high passage. The low-passage subculture cells were treated with transfection of overexpressed prelamin A plasmid, and transfection of overexpressed prelamin A plasmid and application of farnesyl transferase inhibitor (FTIs) H-9279, respectively. Zmpste24, Icmt and lamin A/C expression were detected to explore how prelamin A affected detrusor calcification/aging. Prelamin A was overexpressed in aged detrusor cells, indicating prelamin A expression was positively related to the age of subjects. The degree of prelamin A accumulation and detrusor calcification/aging was higher in aged rats and high passage subculture cells. Zmpste24, Icmt and lamin A/C were poorly expressed in cells transfected with overexpressed prelamin A, as well as cell proliferation activity decreased and calcium deposition and apoptotic rate increased. Furthermore, we also found that the effect of overexpressed prelamin A was lost when cells were treated with H-9279. These findings provide evidence that prelamin A overexpression impairs degradation of its farnesylated form, thus causing prelamin A accumulation which induces detrusor calcification/aging in UI.

CKLF1 Aggravates Focal Cerebral Ischemia Injury at Early Stage Partly by Modulating Microglia/Macrophage Toward M1 Polarization Through CCR4.

CKLF1 is a chemokine with increased expression in ischemic brain, and targeting CKLF1 has shown therapeutic effects in cerebral ischemia model. Microglia/macrophage polarization is a mechanism involved in poststroke injury expansion. Considering the quick and obvious response of CKLF1 and expeditious evolution of stroke lesions, we focused on the effects of CKLF1 on microglial/macrophage polarization at early stage of ischemic stroke (IS). The present study is to investigate the CKLF1-mediated expression of microglia/macrophage phenotypes in vitro and in vivo, discussing the involved pathway. Primary microglia culture was used in vitro, and mice transient middle cerebral artery occlusion (MCAO) model was adopted to mimic IS. CKLF1 was added to the primary microglia for 24 h, and we found that CKLF1 modulated primary microglia skew toward M1 phenotype. In mice transient IS model, CKLF1 was stereotactically microinjected to the lateral ventricle of ischemic hemisphere. CKLF1 aggravated ischemic injury, accompanied by promoting microglia/macrophage toward M1 phenotypic polarization. Increased expression of pro-inflammatory cytokines and decreased expression of anti-inflammatory cytokines were observed in mice subjected to cerebral ischemia and administrated with CKLF1. CKLF1-/- mice were used to confirm the effects of CKLF1. CKLF1-/- mice showed lighter cerebral damage and decreased M1 phenotype of microglia/macrophage compared with the WT control subjected to cerebral ischemia. Moreover, NF-κB activation enhancement was detected in CKLF1 treatment group. Our results demonstrated that CKLF1 is an important mediator that skewing microglia/macrophage toward M1 phenotype at early stage of cerebral ischemic injury, which further deteriorates followed inflammatory response, contributing to early expansion of cerebral ischemia injury. Targeting CKLF1 may be a novel way for IS therapy.

A novel bis-component AIE smart gel with high selectivity and sensitivity to detect CN-, Fe3+ and H2PO4.

A novel bis-component AIE-gel TG was facilely constructed from two "easy-to-synthesize" tripodal gelators by a simple host-guest self-assembly process. Interestingly, the TG shows strong aggregation-induced emission (AIE) and could be used for highly efficient and sensitive detection and separation of ions (CN-, Fe3+ and H2PO4-). The LODs (limits of lowest detection) of TG for CN-, Fe3+ and H2PO4- are in the range of 4.93 × 10-9-7.80 × 10-8 M. Meanwhile, the xerogel of TG could adsorb and separate Fe3+ from aqueous solutions, and the adsorption rate is 96%. In addition, a thin film based on the TG could act as a convenient test kit for the detection of CN- and Fe3+. What is more, the TG-Fe film could not only be used as an erasable secure fluorescent display material, but also as a convenient reversible H2PO4- test kit.

A novel AIE-based supramolecular polymer gel serves as an ultrasensitive detection and efficient separation material for multiple heavy metal ions.

Recently, ultrasensitive stimuli-responsive materials have received extensive attention due to their high sensitivity and wide applications. Herein, we report a novel approach to design ultrasensitive responsive materials by rationally introducing the aggregation-induced emission (AIE) effect into supramolecular polymer gels. According to this approach, by rationally introducing self-assembly moieties and a fluorophore, the obtained gelator DNS can act as an AIEgen; it showed strong AIE after aggregating into the supramolecular polymer gel GDNS. More interestingly, because the aggregation of DNS led to amplification of the detective signal, the AIE-based supramolecular polymer gel GDNS could ultrasensitively detect the heavy metal ions Hg2+, Cu2+, and Fe3+ by a signal amplification mechanism; the lowest detection limits reached 10-11 M. In addition, the xerogel of GDNS could adsorb and separate Hg2+, Cu2+, and Fe3+ from aqueous solution with favourable adsorption properties, and the adsorption rates ranged from 94.70% to 99.37%. Furthermore, the gel GDNS could act as a convenient test kit for Hg2+, Cu2+, and Fe3+ as well as a smart fluorescent display material.

Influence of blood glucose level on the prognosis of patients with diabetes mellitus complicated with ischemic stroke.

We carried out this meta-analysis for the aim of exploring the influence of diabetes mellitus (DM) on the prognosis of patients with ischemic stroke. Relevant studies were identified using computerized databases supplemented with manual search strategies. The included studies were strictly followed the inclusion and exclusion criteria. Case-control studies which related to the influence of DM on the prognosis of patients with ischemic stroke were selected. Statistical analyses were implemented with the STATA version 12.0 statistical software. Our current meta-analysis initially retrieved 253 studies (227 in Chinese and 26 in English), 13 studies (6 in English and 7 in Chinese) were eventually incorporated in this meta-analysis. These 13 case-control studies included 8463 patients altogether (3249 patients with DM complicated with ischemic stroke and 5214 patients with ischemic stroke). The results of this meta-analysis manifested that there was a significant difference of the blood glucose level at 48 h after stroke between patients with DM complicated with ischemic stroke and patients with ischemic stroke (standard mean difference [SMD] =1.27, 95% confidence interval [CI] =0.02-2.51, P = 0.047); however, the effectiveness, fatality, and the National Institutes of Health Stroke Scale (NIHSS) score in patients with DM complicated with ischemic stroke, and patients with ischemic stroke had no significant difference (effectiveness: risk ratio [RR] = 0.88, 95% CI = 0.75-1.03, P = 0.121; fatality: RR = 1.29, 95% CI = 0.97-1.71, P = 0.081; NIHSS score: SMD = -0.14, 95% CI = -1.56-1.28, P = 0.849). The current evidence suggests that there is statistical difference of the blood glucose level at 48 h after stroke between patients with DM complicated with ischemic stroke and patients with ischemic stroke, but there is no statistical difference of prognostic indicators between patients in two groups. Thus, our study provides certain clinical value.

[Establishment of Magnetic Affinity Enzyme Linked Immunoassay Based on Schistosoma japonicum Recombinant Antigen Sj26 and Its Application in Detection of Serum Antibody with Low Intensity of Infection].

Objective: To develop the magnetic affinity enzyme-linked immunoassay (MEIA) using recombinant glutathione-S-transferase of Schistosoma japonicum with a relative molecular weight of 26 000（rSj26-MEIA） for antibody detection under low intensity infection. Methods: The recombinant plasmid pET28a-Sj26 was transformed into Escherichia coli strain BL21, and 0.6 mmol/L isopropyl ß-D-1-thiogalactopyranoside （IPTG） was used to induce its expression. The expression products were purified by Ni2+ （nickel sulfate） affinity chromatography, SDS-PAGE and Western blotting were performed to examine the expression of rSj26. The purified rSj26 was coupled to magnetic beads as capture antigen and the reaction conditions were optimized to establish the rSj26-MEIA method. The method was then used to analyze 58 serum samples from patients with low-intensity S. japonicum infection, 30 serum samples from non-endemic areas as a negative control, and 6 serum samples from patients with paragonimus infection. Results were compared with those obtained with ELISA. Results: The concentration of purified rSj26 was 2.5 mg/ml. The rSj26 had a relative molecular weight of 27 000 and was expressed mainly in the soluble form as revealed by SDS-PAGE. It could be recognized by rabbit and murine sera infected with S. japonicum as shown by Western blotting. Optimization of rSj26-MEIA revealed that use of 0.2 mg magnetic beads loaded with 10 µg rSj26 and serum sample dilution at 1 ∶ 100 yielded the highest ratio of the mean A550 of positive serum to the mean A550 of negative sample (P/N)（3.97）. For serum samples from patients with low-intensity S. japonicum infection, rSj26-MEIA and rSj26-ELISA both resulted in a positive detection rate of 24.14%（14/58）, and P/N values of 3.61 and 2.56. In addition, Pearson's correlation analysis revealed positive correlation between A550 values detected by rSj26-MEIA and by rSj26-ELISA（r=0.658, P<0.01）. Further, no positive reaction was found in the 6 serum samples from patients with paragonimus infection and in the 30 serum samples from non-endemic areas, either by rSj26-MEIA or by rSj26-ELISA. Conclusion: rSj26-MEIA may be used as a new technique for detection of serum antibody against S. japonicum infection with low intensity.