Schistosomiasis remains an important zoonotic parasitic disease, and hepatic fibrosis is a major cause of chronic pathology following Schistosoma japonicum infection. In schistosomiasis, hepatic fibrosis is the major cause of severe pathological damage. However, during the long-term co-evolution and coexistence between Schistosoma parasites and their hosts, the parasite can modulate the host hepatic fibrotic process through extracellular vesicle (EV)-mediated cross-species communication. In this study, we identified an EV-derived microRNA from Schistosoma japonicum, sja-miR-2a-3p, that suppresses hepatic pathology in the host. Using transwell co-culture and EV-isolation experiments, we confirmed that the helminth-specific sja-miR-2a-3p could be transferred to hepatic stellate cells (HSCs) via EVs. Bioinformatic and dual-luciferase assays revealed that host BCL2, a major anti-apoptotic gene, is a direct target of sja-miR-2a-3p. In vitro, sja-miR-2a-3p overexpression suppressed HSC proliferation and migration and induced mitochondrial dysfunction, caspase-3/-7/-9 activation, and apoptosis. In vivo, administration of sja-miR-2a-3p agomir to S. japonicum-infected mice significantly downregulated hepatic BCL2 expression, enhanced HSC apoptosis, alleviated granuloma formation, collagen deposition, and inflammation. Collectively, our findings reveal that schistosome EV-delivered sja-miR-2a-3p attenuates liver fibrosis by promoting mitochondrial apoptosis and functionally suppressing HSC activation. This study supports sja-miR-2a-3p as a candidate antifibrotic molecule.

Schistosoma japonicum develops efficiently in BALB/c mice but poorly in less-permissive Wistar rats. Previous studies showed that parasites from Wistar rats display higher apoptotic activity, while sja-miR-2a-3p is more highly expressed in Wistar rat-derived schistosomula. This study examined whether sja-miR-2a-3p is associated with apoptosis-related responses in S. japonicum. Published small RNA-seq datasets were reanalyzed to assess sja-miR-2a-3p expression during worm development and in schistosomula from BALB/c mice and Wistar rats. Regional expression of sja-miR-2a-3p was examined in dissected male and female worms. Predicted targets were subjected to enrichment analysis. Adult paired worms were cultured in vitro and treated with sja-miR-2a-3p mimics, inhibitor, or corresponding negative controls. miRNA expression, egg output, apoptosis-related gene expression and TUNEL signals were evaluated. sja-miR-2a-3p was expressed from 14 to 28 days post infection and was higher in Wistar rat-derived schistosomula than in BALB/c mouse-derived schistosomula. In adult worms, sja-miR-2a-3p was enriched in the male testis/posterior region and female vitellaria. Target enrichment suggested involvement in stimulus response, growth, biological regulation, homeostasis and signaling pathways. Mimic treatment increased sja-miR-2a-3p levels and upregulated multiple apoptosis-associated genes, including sjaAIF, sjaAPAF, sjaBAX, sjaCASP3, sjaCASP9, sjaCYC and sjaTNFR. TUNEL staining further showed increased apoptotic signals after sja-miR-2a-3p overexpression. sja-miR-2a-3p is a tissue-biased miRNA linked to apoptosis-related responses in S. japonicum. These findings suggest that elevated sja-miR-2a-3p may contribute to the increased apoptotic state of parasites developing in less-permissive hosts.

Although schistosome eggs are widely recognized as the principal drivers of hepatic granulomatous inflammation and fibrosis, the independent effects of adult worms may be masked by strong egg antigen-mediated responses. This study aimed to investigate whether adult Schistosoma japonicum worms alter the miRNA expression profile of hepatic stellate cells and to explore the potential relevance of these changes to liver fibrosis and hepatocellular carcinoma-related processes. A non-contact Transwell co-culture system was established using paired Schistosoma japonicum worms or male worms and hepatic stellate cells. Male worms were additionally included to further assess worm-derived effects independent of egg production-related influences. Untreated hepatic stellate cells served as controls. Total RNA was extracted for miRNA sequencing, and differentially expressed miRNAs were identified. Target gene prediction, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, and validation using The Cancer Genome Atlas database were subsequently performed. Both paired worms and male worms significantly altered the miRNA expression profile of hepatic stellate cells. Several differentially expressed miRNAs were identified, among which hsa-miR-103a-3p showed relatively stable changes. Pathway enrichment analysis suggested that the potential target genes of hsa-miR-103a-3p were mainly enriched in AMP-activated protein kinase, mechanistic target of rapamycin, tumor necrosis factor, insulin signaling, and cellular senescence pathways. Further analysis using The Cancer Genome Atlas database showed that hsa-miR-103a-3p had diagnostic value in hepatocellular carcinoma and was associated with alpha-fetoprotein level, albumin level, Ishak fibrosis score, pathological stage, histological type, and tumor status. These findings suggest that adult S. japonicum worms may alter the miRNA expression profile of hepatic stellate cells, and that hsa-miR-103a-3p may be associated with fibrogenic responses and may have potential relevance to hepatocellular carcinoma-related processes. However, this inference is based on correlative TCGA data and does not imply a causal role in schistosomiasis-associated hepatocarcinogenesis.

Background: Fascioliasis, caused by Fasciola species, is a significant public health concern affecting over 250 million people globally and causing annual economic losses exceeding USD 6 billion. The sole FDA-approved treatment, triclabendazole (TCZ), faces increasing resistance due to extensive use, highlighting the urgent need for alternative therapeutic targets. A promising candidate is thioredoxin glutathione reductase (TGR), a multifunctional enzyme unique to platyhelminths, essential for redox balance and parasite survival. Methods: This study investigated the antioxidant and enzymatic activities of recombinant Fasciola gigantica TGR (FgTGR), its localization within the parasite, and its inhibition by furoxan derivatives. FgTGRsec (FgTGR containing selenocysteine) was expressed and purified, and its enzymatic activities, including thioredoxin reductase (TrxR), glutathione reductase (GR), and glutaredoxin (Grx), were characterized. Results: Immunolocalization studies revealed FgTGR’s presence in critical tissues, underscoring its functional significance. Antioxidant assays demonstrated the protein’s role in protecting against oxidative damage. Inhibition assays with furoxan derivatives identified potential inhibitors targeting TGR activity. Sequence and phylogenetic analyses showed FgTGR’s evolutionary conservation among trematodes, confirming its potential as a drug target. Conclusions: The study’s findings establish FgTGR as a critical enzyme for parasite survival and a promising target for developing novel therapeutics. These results pave the way for the further screening and optimization of TGR inhibitors, offering a strategic approach to overcoming TCZ resistance and improving fascioliasis control.

Schistosomiasis, a neglected tropical disease, remains a pressing global health challenge, hindering progress toward achievement of the Sustainable Development Goals (SDGs) in endemic regions. Despite advances in control strategies, including preventive chemotherapy and integrated measures, the elimination of schistosomiasis remains an elusive goal. Current understanding of schistosomiasis pathogenesis has largely focused on egg-induced pathology, while the contributions of schistosome worms to disease progression are relatively underexplored. The objective of this article is to highlight the critical, yet overlooked, role of schistosome worms in disease progression and to advocate for a broader research focus on their direct impact on host pathology and efforts towards disease elimination. Single-sex schistosome infections, which may occur in low-transmission areas, deserve greater attention as they evade traditional egg-based diagnostics. These infections also provide a valuable model to explore the direct contributions of worms to host pathology. Recent studies suggest that schistosome worms, via their excretory-secretory products (ESPs), contribute to liver inflammation, fibrosis, and immune modulation independent of egg deposition. Understanding the interactions between worms and hosts is essential for elucidating their role in disease progression. Furthermore, the potential similarities between schistosome ESPs and those of carcinogenic trematodes highlight the need for further investigation into their long-term impact on host health and schistosomiasis pathology. Expanding the focus of schistosomiasis research to include the role of schistosome worms is essential for advancing diagnostic and therapeutic strategies. By incorporating single-sex infection models and targeting worm-derived molecules, it is possible to uncover the overlooked aspects of schistosomiasis pathogenesis, improve diagnostic accuracy, and support global elimination efforts, thereby contributing to the realization of the SDGs.

Schistosoma japonicum is a dioecious parasite that requires constant pairing between male and female worms for female maturation and egg production. MicroRNAs (miRNAs) play crucial roles in regulating various biological processes, including parasite development and host-pathogen interactions, but their functions in schistosomes remain largely unexplored. This study aimed to investigate the differentially expressed miRNAs (DEMs) between mated male (MM) and single-sex male (SM) worms to gain insights into their regulatory roles in schistosome reproduction. Total RNA was extracted from 28-day-old MM and SM worms, followed by small RNA sequencing to identify DEMs. Bioinformatics analyses were used to predict the biological functions of DEM target genes. Comparative analysis with previously published miRNA datasets helped identify potentially significant miRNAs. Quantitative PCR (qPCR) validated the expression of selected miRNAs and mRNA levels of some target genes. A total of 20 DEMs were identified, with 9 upregulated in MM worms and 11 in SM worms. These DEMs may regulate processes such as intracellular transport, RNA processing, and cellular homeostasis. The study provides novel insights into the biological differences between SM and MM worms, suggesting that these miRNAs could be key regulators of parasite development and host adaptation, with potential diagnostic and therapeutic applications in schistosomiasis.

Schistosomiasis, a neglected tropical disease caused by Schistosoma species, remains a significant global health issue. One of its severe complications is liver fibrosis. The role of schistosome worms in liver fibrosis has been largely understudied, with most research focusing on the effects of schistosome eggs. This study investigates the direct impact of Schistosoma japonicum worms on liver fibrosis and explores the potential molecular mechanisms, particularly the role of microRNAs (miRNAs) secreted by the worms. RNA sequencing and small RNA sequencing were employed to investigate the effects of S. japonicum worms on hepatic stellate cells (HSCs) within a Transwell co-culture system. Bioinformatic tools were utilized to predict target genes for identified S. japonicum-derived miRNAs. A mouse model was used, encompassing both bisexual and single-sex male worm infections. Immunohistochemistry and fluorescence in situ hybridization revealed that S. japonicum infection significantly upregulated fibrosis-related proteins in liver tissues, particularly in the periportal regions in the single-sex male infection group. RNA-seq analysis indicated that schistosome worms could influence the gene expression profiles of HSCs, with significant enrichment in collagen organization and fibrosis-related signaling pathways. miRNA profiling identified several Sj-miRNAs, including sja-miR-277, which was shown to inhibit HSC proliferation and activation in vitro. Co-localization of sja-miR-277 with the HSC activation marker α-SMA in liver sections confirmed the involvement of worm-derived miRNAs in HSC activation. Overall, these findings provide novel insights into the role of worm-derived molecules in schistosome-induced liver fibrosis and highlight potential targets for therapeutic intervention.

Schistosomiasis remains a significant public health concern, with Schistosoma japonicum infection endemic in certain regions of Asia. Praziquantel (PZQ), primarily known as an effective therapeutic agent, has recently shown potential as a prophylactic measure against delayed S. japonicum infections. This study investigated the preventive efficacy of PZQ pretreatment at varying cercarial infection intensities and determined the parasite developmental stages targeted by the pretreatment in a mouse model. Results demonstrated that PZQ pretreatment significantly reduced both worm burdens and liver egg counts at low (10 and 20 cercariae) and high (100 cercariae) infection intensities, with reductions in worm burdens ranging from approximately 48% to 60% and liver egg counts by 47% to 73% compared to control groups (p < 0.05). Further analysis revealed that the mortality of parasites in PZQ-pretreated mice predominantly occurred during the juvenile schistosomula stages, particularly in worms younger than 15 days post-infection. These findings provide critical evidence supporting the application of PZQ pretreatment as a practical prophylactic measure to prevent S. japonicum infections, particularly in populations and animals frequently exposed to contaminated water in endemic areas.

Schistosomiasis has been recognized as the second most prevalent parasitic disease worldwide, following malaria. Schistosome eggs can persist for extended periods within host hepatic tissues, leading to hepatic fibrosis primarily through the activation of hepatic stellate cells (HSCs). However, the mechanisms by which egg-secreted products modulate the activation of HSCs remain incompletely elucidated. In this study, purified Schistosoma japonicum (S. japonicum) eggs (Egg group) or corresponding unused medium (Control group) were placed in the upper chamber of a Transwell system, with HSCs cultured in the lower chamber. Following co-culture, HSCs surface proteins were eluted and subsequently analyzed by mass spectrometry. Protein identities were determined by matching spectral data against both human and schistosome protein databases. A total of 88 schistosome proteins, including both S. japonicum-specific and non-specific proteins, were identified in the Egg group. Bioinformatic analyses suggested that HSCs were exposed to egg-derived secretory proteins, indicating potential molecular interactions between schistosome eggs and host cells. Furthermore, RNA-sequencing was performed on HSCs following co-culture, resulting in the identification of 634 differentially expressed genes (DEGs), of which 454 were upregulated and 180 were downregulated. Functional enrichment analyses revealed significant involvement of these DEGs in fibrosis- and inflammation-related pathways. Collectively, this study provides novel evidence that S. japonicum eggs may remotely modulate the transcriptional profiles of HSCs via secreted bioactive molecules, thus offering a theoretical foundation for identifying potential therapeutic targets in hepatic fibrosis.

Schistosoma japonicum, a parasitic flatworm, exhibits the special biological phenomenon of male-female pairing, essential for the reproductive maturation and egg production of female worms. MicroRNAs (miRNAs) are known to regulate female reproductive development, yet the roles of individual miRNAs in schistosome reproduction remain poorly defined. Among them, the conserved let-7 family, identified in S. japonicum as early as 2008, has not been explored for its specific biological functions. Expression profiling of sja-let-7 was first conducted across multiple datasets and validated through qPCR. Bioinformatic tools were used to predict sja-let-7 target genes, and fluorescence in situ hybridization (FISH) was employed to determine sja-let-7 localization in reproductive organs. Functional studies involving sja-let-7 modulation through mimics and inhibitors in vitro, and agomir and antagomir treatments in vivo, were conducted to evaluate its impact on female reproductive development, target gene regulation, and egg production. Results showed that sja-let-7 demonstrated prominent localization in the Mehlis' gland, ovaries, and vitellaria of female. Sjcdc23, a potential target gene of sja-let-7, was implicated to play a potential role in reproductive processes of schistosomes. Overexpression or inhibition of sja-let-7 significantly impaired egg production and quality in vitro. In vivo experiments demonstrated disrupted vitellaria development and reduced egg production in agomir-treated worms, while antagomir treatment also decreased egg production, suggesting that sja-let-7 is crucial for female reproductive development and egg-laying capacity, providing novel insights into miRNA-mediated regulatory mechanisms in parasitic helminths.

Liver fibrosis, a critical precursor to hepatocellular carcinoma (HCC), results from chronic liver injury and significantly contributes to HCC progression. Schistosomiasis, a neglected tropical disease, is known to cause liver fibrosis; however, this process can be modulated by schistosome-derived miRNAs. Previous studies from our laboratory have demonstrated that Schistosoma japonicum extracellular vesicles (EVs) deliver sja-let-7 to hepatic stellate cells, leading to the inhibition of Col1α2 expression and alleviation of liver fibrosis. Given the well-documented antifibrotic and antiproliferative properties of the let-7 miRNA family, this study aims to preliminarily investigate the effects of the sja-let-7/Col1α2 axis on BALB/c mice and HCC cell line SNU387, providing a basis for the potential application of parasite-derived molecules in HCC therapy. In the present study, schistosome-induced fibrosis datasets were analyzed to identify the role of Col1α2 in extracellular matrix organization. Pan-cancer analysis revealed that Col1α2 is upregulated in various cancers, including HCC, with significant associations with immune cell infiltration and clinical parameters, highlighting its diagnostic importance. Functional assays demonstrated that transfection with sja-let-7 mimics significantly reduced Col1α2 expression, inhibited HCC cell proliferation, migration, and colony formation. These findings suggest that sja-let-7, by targeting Col1α2, has the potential to serve as a therapeutic agent in HCC treatment. This study indicates the pivotal role of Col1α2 in liver fibrosis and HCC, and the promising therapeutic application of helminth-derived miRNAs.

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Schistosomiasis, caused by Schistosoma japonicum, continues to pose a major public health threat in East Asia, with an estimated 71 million people at risk of infection. Domestic animals, especially buffaloes and goats, serve as important reservoir hosts, facilitating the transmission of the parasite to humans. While praziquantel (PZQ) is the first-line treatment for schistosomiasis due to its broad-spectrum efficacy against adult schistosomes, its prophylactic potential is less explored. This study aimed to evaluate the efficacy of PZQ in preventing S. japonicum infection in buffaloes and goats via assessing worm burden, worm size, hematological changes, and immune modulation. In the present study, buffaloes and goats were pretreated with PZQ at various doses (7–25 mg/kg body weight), followed by infection with S. japonicum cercariae. The results showed significant reductions in total worm burden and female worm burden, with one oral administration at 13 mg/kg for buffaloes and one injection at 25 mg/kg for goats offering the most robust protection. Worm length was also significantly reduced in both buffaloes and goats, indicating that PZQ not only prevented infection in this study but also inhibited worm growth. Furthermore, PZQ pretreatment modulated immune responses, as evidenced by increased levels of nitric oxide (NO) and interleukin-2 (IL-2) in buffaloes and Lym% in goats. These findings suggest that PZQ has significant prophylactic potential in livestock, offering a practical solution for reducing schistosome transmission from animals to humans in endemic regions. Additionally, this study indicates that PZQ pretreatment does not contribute to resistance development, as newly established infections are effectively cleared during the initial treatment window.

Schistosomiasis is a fatal zoonotic parasitic disease that also threatens human health. The main pathological features of schistosomiasis are granulomatous inflammation and subsequent liver fibrosis, which is a complex, chronic, and progressive disease. Extracellular vesicles (EVs) derived from schistosome eggs are broadly involved in host-parasite communication and act as important contributors to schistosome-induced liver fibrosis. However, it remains unclear whether substances secreted by the EVs of Schistosoma japonicum, a long-term parasitic “partner” in the hepatic portal vein of the host, also participate in liver fibrosis. Here, we report that EVs derived from S. japonicum worms attenuated liver fibrosis by delivering sja-let-7 into hepatic stellate cells (HSCs). Mechanistically, activation of HSCs was reduced by targeting collagen type I alpha 2 chain (Col1α2) and downregulation of the TGF-β/Smad signaling pathway both in vivo and in vitro. Overall, these results contribute to further understanding of the molecular mechanisms underlying host-parasite interactions and identified the sja-let-7/Col1α2/TGF-β/Smad axis as a potential target for treatment of schistosomiasis-related liver fibrosis.

The prevalence and infectious intensity of schistosomiasis japonica has decreased significantly in China in the past few decades. However, more accurate and sensitive diagnostic methods are urgently required for the further control, surveillance, and final elimination of the disease. In this study, we assessed the diagnostic efficacy of a real-time fluorescence quantitative PCR (qPCR) method and recombinase polymerase amplification (RPA) combined with a lateral-flow dipstick (LFD) assay for detecting early infections of Schistosoma japonicum and different infection intensities. The sensitivity of the qPCR at 40 days post-infection (dpi) was 100% (8/8) in mice infected with 40 cercariae, which was higher than in mice infected with 10 cercariae (90%, 9/10) or five cercariae (77.8%, 7/9). The results of the RPA–LFD assays were similar, with sensitivities of 55.6% (5/9), 80% (8/10), and 100% (8/8) in mice infected with 5, 10, and 40 cercariae, respectively. In goats, both the qPCR and RPA–LFD assays showed 100% (8/8) sensitivity at 56 dpi. In the early detection of S. japonicum infection in mice and goats with qPCR, the first peak in positivity appeared at 3–4 dpi, when the positivity rate exceeded 40%, even in the low infection, intensity mice. In the RPA–LFD assays, positive results first peaked at 4–5 dpi in the mice, and the positivity rate was 37.5% in the goats at 1 dpi. In conclusion, neither of the molecular methods produced exceptional results for the early diagnosis of S. japonicum infection. However, they were useful methods for the regular diagnosis of schistosomiasis in mice and goats.

As-cast alloys generally require additional processing steps before optimal strength-ductility combinations can be achieved, thereby impeding the progress of manufacturing high-performance metallic products by direct casting. Here we report a novel low-cost FeNi0.9Cr0.5Al0.4 high entropy alloy with unique fibrous heterogeneous solidification microstructure, i.e., fibers-like face-centered-cubic soft phases that are enveloped in nano-sized ordered body-centered-cubic hard shells. This fibrous microstructure is thought to be responsible for the notable mechanical properties, which includes a yield strength of ∼670 MPa and an ultimate tensile strength of ∼1196 MPa, together with a uniform elongation of ∼21.1% at room temperature. Experimental results confirm the suggestion that the combination of a high strength and good ductility can be attributed to the hetero-deformation induced hardening mechanism generated from the soft-fiber and hard-shell interface. The cost-effectiveness of this as-cast FeNi0.9Cr0.5Al0.4 alloy with its unique fibrous structure and outstanding tensile properties renders it an ideal candidate for structural applications.

Schistosomiasis is a neglected tropical disease that affects humans and animals in tropical and subtropical regions worldwide. Schistosome eggs are responsible for the pathogenesis and transmission of schistosomiasis, thus reducing egg production is vital for prevention and control of schistosomiasis. However, the mechanisms underlying schistosome reproduction remain unclear. Annexin proteins (ANXs) are involved in the physiological and pathological functions of schistosomes, but the specific regulatory mechanisms and roles of ANX A13 in the development of Schistosoma japonicum and host–parasite interactions remain poorly understood. Therefore, in this study, the expression profiles of SjANX A13 at different life cycle stages of S . japonicum were assessed using quantitative PCR. In addition, the expression profiles of the homolog in S. mansoni were analyzed in reference to public datasets. The results of RNA interference showed that knockdown of SjANX A13 significantly affected the development and egg production of female worms in vivo. The results of an immune protection assay showed that recombinant SjANX A13 increased production of immunoglobulin G-specific antibodies. Finally, co-culture of S. japonicum exosomes with LX-2 cells using a transwell system demonstrated that SjANX A13 is involved in host–parasite interactions via exosomes. Collectively, these results will help to clarify the roles of SjANX A13 in the development of S. japonicum and host–parasite interactions as a potential vaccine candidate.

高州油茶Camellia gauchowensis是华南区域主栽油茶品种之一.探讨核算其林分固碳释氧和增湿降温能力,旨在为其生态功能综合评价提供数据参考.文章以揭阳市内高州油茶成林为研究对象,采用光合仪测定其光合蒸腾参数;利用积分法测算其单位叶面积固碳量、释氧量、增湿量和降温量;结合叶面积指数核算其单位林地面积固碳量、释氧量、增湿量和降温量;运用环境效益评价法估算揭阳市内现有高州油茶林生态效益.结果表明高州油茶单位叶面积固碳量、释氧量、增湿量和降温量存在明显的季节差异,固碳释氧能力夏季高于冬季,全年季节变化由大到小依次为9 月、7 月、1 月、3 月和 11 月,其单位叶面积日平均固碳量和释氧量分别为 6.777 g·m-2·d-1、4.929 g·m-2·d-1;增湿降温作用夏季明显,全年季节变化由大到小依次为 7 月、9 月、11 月、1 月和 3 月,分别为 1 090.073 g·m-2·d-1 和 0.210℃;高州油茶单位林地面积日平均固碳量、释氧量、增湿量和降温量分别为 18.841 g·m-2·d-1、13.702 g·m-2·d-1、3 030.402 g·m-2·d-1、0.585℃.揭阳市现有高州油茶林面积为 1 400 hm2,其全年固碳量、释氧量、增湿量和降温量分别为6.07 万t、4.41 万t、975.79 万t、1.88×109℃.揭阳市全年固碳释氧及增湿降温计量获得的总货币效益为5.68 亿元.由此可见,高州油茶具有良好的生态功能效益.

获取化学品的生物积累性数据是评价其生态及健康风险的前提.基于机器学习算法的模型已被用于生物积累性预测,填补相关数据空缺.但已有预测模型仅针对单一终点,忽略了不同终点间的内在联系.基于多任务学习算法的模型,有望实现多个生物积累参数的同时预测.本研究采用反向传播(back-propagation,BP)神经网络机器学习算法,基于分子Dragon描述符和4种分子指纹,建立了可同时预测化学品鱼体生物富集因子(BCF)和生物放大因子(BMF)的多任务模型,并与单任务模型进行了比较.结果表明,多任务模型的拟合效果、稳健性和预测能力均优于单任务模型.采用Dragon描述符作为输入的多任务模型表现最好,其训练集的决定系数(R2)、均方根误差(RMSE)和平均绝对误差(MAE)分别为0.925～0.964、0.168～0.247和0.133;验证集的 R2、RMSE 和 MAE 分别为 0.771～0.894、0.176～0.213 和 0.168～0.176;10 折交叉验证系数(Q2cv)为 0.785～0.867.基于验证集与训练集分子间的谷本相似度表征了模型应用域.本研究所建模型可有效填补化学品生物积累性数据,为化学品生物积累性及风险评价提供技术支持.

The prevalence of schistosomiasis japonica in China is now characterized by a low epidemic rate and low-intensity infections. Some diagnostic methods with high sensitivity and specificity are urgently needed to better monitor this disease in the current situation. In this study, the detection efficacy of a real-time fluorescent quantitative PCR (qPCR) assay was assessed for schistosomiasis japonica in mice, and before and after treatment with praziquantel (PZQ). Our results showed that the sensitivity of the qPCR was 99.3% (152/153, 95% CI: 96.41-99.98%) and its specificity was 100% (77/77, 95% CI: 95.32-100%) in mice infected with different numbers of Schistosoma japonicum. After the oral administration of PZQ, mice infected with 10 cercariae or 40 cercariae were all Schistosoma japonicum-negative 6 weeks after treatment. However, the negativity rates on a soluble egg antigen (SEA)-based enzyme-linked immunosorbent assay (ELISA) were only 34.8% (8/23, 10 cercariae group) and 6.7% (1/15, 40 cercariae group) at the sixth week after PZQ treatment. These results demonstrated that the qPCR method had good sensitivity and specificity, and suggested that its sensitivity correlated with the infection intensity in mice. Moreover, this method had better potential utility for evaluating the treatment efficacy of PZQ in schistosome-infected mice than SEA-based ELISA.