1.Development and preliminary evaluation of a fluorescence RPA assay for the rapid detection of Necator americanus
LIANG Jiarui ; XU Bin ; HU Wei ; LI Mengru ; YANG Shuo ; ZHENG Bin
China Tropical Medicine 2023;23(7):681-
Abstract: Objective To establish a rapid detection assay based on fluorescence recombinase polymerase amplification (RPA) targeting Necator americanus eggs, and to evaluate its efficacy, providing technical support for rapid detection of Necator americanus in fecal samples. Methods The fluorescence RPA primers and probe were designed based on the cox1 gene of Necator americanus and then screened the optimal combination to develop the assay. The genomic DNA of Necator americanus eggs was diluted to 7 concentration gradients including 100 pg/µL, 10 pg/µL, 1 pg/µL, 100 fg/µL, 10 fg/µL, 1 fg/µL, 0.1 fg/µL, to determine the detection limit of the assay. The specificity of the assay was demonstrated by detected genomic DNA from Schistosoma japonicum, Ascaris lumbricoides, Clonorchis sinensis and Fasciola hepatica. A total of 44 fecal samples were collected and DNA extraction was performed, and the modified Kato-Katz method, semi-nest PCR method, and fluorescent RPA method were simultaneously used for detection to evaluate the sensitivity and specificity. Results The established fluorescence RPA assay can specifically amplify a fragment of 194 bp of the Necator americanus cox1 gene within 20 min, with a detection limit of 10 fg/µL. There was no cross-reactivity with Schistosoma japonicum, Ascaris lumbricoides, Clonorchis sinensis, Fasciola hepatica after specificity validation. In 44 fecal samples, 27 positive samples were detected by the fluorescence RPA assay, and 26 positive samples were detected by both the Kato-Katz and the semi-nested PCR. The fluorescence curve of sample number 1 was slightly higher than the negative control in the later stage of the reaction, but did not show a similar trend to the positive control, and was therefore judged to be a suspected negative sample. Compared with the Kato-Katz method and the semi-nest PCR method, The sensitivity of the fluorescent RPA method were 100.00% and the specificity were 94.44%, and the consistency of the detection results was good (Kappa=0.953>0.75). Conclusions The assay based on the fluorescence RPA is an efficient, sensitive and specific technique for detecting Necator americanus and it can be applied for surveillance and early warning of hookworm infection.
2.Establishment and evaluation of a LAMP-CRISPR-based nucleic acid detection method for Schistosoma japonicum
LI Mengru ; QIN Zhiqiang ; YIN Kun ; LIANG Jiarui ; YANG Shuo ; ZHENG Bin
China Tropical Medicine 2023;23(7):686-
Abstract: Objective To establish a sensitive and specific nucleic acid detection method for Schistosoma japonicum based on loop-mediated isothermal amplification (LAMP) and clustered regularly interspaced short palindromic repeats (CRISPR) technology. Methods The LAMP primers, gRNA and ssDNA probe that target Schistosoma japonicum SjR2 genes were designed according to the principles of LAMP and CRISPR. The LAMP-CRISPR reaction system was established and optimized. The sensitivity and specificity of the method were evaluated against the ten-fold serial dilutions of plasmid containing SjR2 target sequences, as well as genomic DNA at different stages of Schistosoma japonicum and other parasites, including Fasciola hepatica, Schistosoma mansoni, Taenia saginata, Clonorchis sinensis, Ascaris lumbricoides, Necator americanus, Paragonimus westermani, and Echinococcus granulosus. Additionally, 15 schistosome-infected snail and 30 uninfected samples were tested by LAMP-CRISPR and LAMP methods, respectively, to evaluate the potential of this method for screening for infected snails. Results The developed LAMP-CRISPR method was able to specifically amplify and detect the SjR2 gene of S. japonicum. The optimal reaction temperature was 37 ℃, and the optimal reaction concentrations were both 40 nmol/L for gRNA and Cas12a protein. No cross-reaction was observed with genomic DNA from other parasites such as F. hepatica. The detection limit of the method was 10 copies/μL when testing 10-fold dilutions of recombinant plasmids as a template. Furthermore, the LAMP-CRISPR method was able to accurately detect genomic DNA from S. japonicum at various stages of development, including eggs, cercariae, schistosomula, juvenile worms, and adult worms. The results of testing 45 snail samples showed no significant difference between the LAMP-CRISPR and LAMP methods for detecting infected snails (χ2=0.05, P>0.05). The sensitivity and specificity of the LAMP-CRISPR method were 100.00% (15/15) and 96.67% (29/30), respectively, compared to the gold standard, while the sensitivity and specificity of the LAMP method were 100.00% (15/15) and 93.33% (28/30), respectively. Conclusions This established LAMP-CRISPR detection method presented good sensitivity, specificity and reliability, making it a promising tool for rapid detection and risk monitoring of S. japonicum.
3.The osteoclastic activity in apical distal region of molar mesial roots affects orthodontic tooth movement and root resorption in rats
Zheng WENHAO ; Lu XIAOFENG ; Chen GUANGJIN ; Shen YUFENG ; Huang XIAOFEI ; Peng JINFENG ; Wang JIAJIA ; Yin YING ; Song WENCHENG ; Xie MENGRU ; Yu SHAOLING ; Chen LILI
International Journal of Oral Science 2024;16(2):322-332
The utilization of optimal orthodontic force is crucial to prevent undesirable side effects and ensure efficient tooth movement during orthodontic treatment.However,the sensitivity of existing detection techniques is not sufficient,and the criteria for evaluating optimal force have not been yet established.Here,by employing 3D finite element analysis methodology,we found that the apical distal region(A-D region)of mesial roots is particularly sensitive to orthodontic force in rats.Tartrate-resistant acidic phosphatase(TRAP)-positive osteoclasts began accumulating in the A-D region under the force of 40 grams(g),leading to alveolar bone resorption and tooth movement.When the force reached 80 g,TRAP-positive osteoclasts started appearing on the root surface in the A-D region.Additionally,micro-computed tomography revealed a significant root resorption at 80 g.Notably,the A-D region was identified as a major contributor to whole root resorption.It was determined that 40 g is the minimum effective force for tooth movement with minimal side effects according to the analysis of tooth movement,inclination,and hyalinization.These findings suggest that the A-D region with its changes on the root surface is an important consideration and sensitive indicator when evaluating orthodontic forces for a rat model.Collectively,our investigations into this region would aid in offering valuable implications for preventing and minimizing root resorption during patients'orthodontic treatment.
4.Study on the correlation between prognosis of patients with chronic hepatitis B under interferon treatment and polymorphism of both calcitonin gene related peptide and receptor activity modifying protein 1
Li ZHANG ; Lin ZHOU ; Xia GAO ; Xuran ZHENG ; Mengru YANG ; Ning ZHANG ; Gang YANG ; Wenxuan LIU
Chinese Journal of Epidemiology 2020;41(6):924-928
Objective:To analyze the association of two single-nucleotide polymorphisms (SNP) [Calcitonin gene related peptide (CGRP) rs155209 and receptor activity modifying protein 1 (RAMP1) rs3754701] and the prognosis of chronic hepatitis B patients who were under interferon therapy.Methods:A total of 317 patients and their anticoagulant blood samples were collected in this study. The SNPs in the CGRP and region RAMP1 were genotyped using matrix-assisted laser desorption/ionization time of flight mass spectrometry. Logistic regression method was used to assess the results from different phenotypic outcomes between cases and controls, after adjusted for sex and age in co-dominant, dominant and recessive genetic models.Results:Data from this study clearly demonstrated the relevance of CGRP rs155209 and RAMP1 rs3754701 with DNA response and ALT response. RAMP1 rs3754701T was strongly associated with both DNA response and ALT response ( OR=2.277, 95 %CI: 1.386-3.741, P=0.001; OR=1.694, 95 %CI: 1.073-2.675, P=0.024). However, CGRP rs155209C was less prone to DNA response and ALT response ( OR=0.150, 95 %CI: 0.083-0.271, P<0.001; OR=0.583, 95 %CI: 0.367-0.925, P=0.022). Conclusions:Results from our study suggested that both RAMP1 rs3754701 and CGRP rs155209 were associated with the prognosis of patients under interferon therapy in Han population, from the northern parts of China while RAMP1 rs3754701T was a protective factor for both ALT response and DNA response, but CGRP rs155209C carriers were less prone to DNA and ALT responses.
5.Progress in research and application of risk assessment methods for imported malaria in China
Shuo YANG ; Hanyin YANG ; Shuning YAN ; Jiarui LIANG ; Mengru LI ; Bin ZHENG ; Zhigui XIA ; Shang XIA
Chinese Journal of Epidemiology 2023;44(11):1820-1824
With the gradual resumption of international travel, cross-border population movement has become frequent again, risk assessment of imported malaria has important public health significance to maintain malaria elimination status in China. Currently, risk index system construction method, risk index method, mathematical model method, and infectivity-receptivity- vulnerability method are mainly used in imported malaria risk assessment in China. This paper summarizes the common evaluation methods in the risk assessment of imported malaria research in China to provide references for the further research.
6.Construction and practice of the theory of “turbid toxin pathogenesis” and related prevention and treatment strategies for hepatic encephalopathy in traditional Chinese medicine/Zhuang medicine
Zhipeng WU ; Yuqin ZHANG ; Chun YAO ; Minggang WANG ; Na WANG ; Mengru PENG ; Ningfang MO ; Yaqing ZHENG ; Rongzhen ZHANG ; Dewen MAO
Journal of Clinical Hepatology 2025;41(2):370-374
Hepatic encephalopathy is a difficult and critical disease with rapid progression and limited treatment methods in the field of liver disease, and it is urgently needed to make breakthroughs in its pathogenesis. Selection of appropriate prevention and treatment strategies is of great importance in delaying disease progression and reducing the incidence and mortality rates. This article reviews the theory of “turbid toxin pathogenesis” and related prevention and treatment strategies for hepatic encephalopathy in traditional Chinese medicine/Zhuang medicine, proposes a new theory of “turbid toxin pathogenesis”, analyzes the scientific connotations of “turbid”, “toxin”, and the theory of “turbid toxin pathogenesis”, and constructs the “four-step” prevention and treatment strategies for hepatic encephalopathy, thereby establishing the new clinical prevention and treatment regimen for hepatic encephalopathy represented by “four prescriptions and two techniques” and clarifying the effect mechanism and biological basis of core prescriptions and techniques in the prevention and treatment of hepatic encephalopathy, in order to provide a reference for the prevention and treatment of hepatic encephalopathy.
7.Application of CRISPR/Cas systems in the nucleic acid detection of pathogens: a review
Mengru LI ; Zhiqiang QIN ; Kun YIN ; Bin ZHENG
Chinese Journal of Schistosomiasis Control 2023;35(1):98-103
Rapid, sensitive and specific detection tools are critical for the prevention and control of infectious diseases. The in vitro nucleic acid amplification assays, including polymerase chain reaction and isothermal amplification technology, have been widely used for the detection of pathogens. Recently, nucleic acid detection-based on clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) have been developed, which are rapid, highly sensitive, highly specific, and portable. This review describes the classification and principle of CRISPR/Cas systems and their applications in pathogen detection, and discusses the prospects of CRISPR/Cas systems.
8.Natural compounds modulate the autophagy with potential implication of stroke.
Anil AHSAN ; Mengru LIU ; Yanrong ZHENG ; Wenping YAN ; Lin PAN ; Yue LI ; Shijia MA ; Xingxian ZHANG ; Ming CAO ; Zhanxun WU ; Weiwei HU ; Zhong CHEN ; Xiangnan ZHANG
Acta Pharmaceutica Sinica B 2021;11(7):1708-1720
Stroke is considered a leading cause of mortality and neurological disability, which puts a huge burden on individuals and the community. To date, effective therapy for stroke has been limited by its complex pathological mechanisms. Autophagy refers to an intracellular degrading process with the involvement of lysosomes. Autophagy plays a critical role in maintaining the homeostasis and survival of cells by eliminating damaged or non-essential cellular constituents. Increasing evidence support that autophagy protects neuronal cells from ischemic injury. However, under certain circumstances, autophagy activation induces cell death and aggravates ischemic brain injury. Diverse naturally derived compounds have been found to modulate autophagy and exert neuroprotection against stroke. In the present work, we have reviewed recent advances in naturally derived compounds that regulate autophagy and discussed their potential application in stroke treatment.
9.Spatiotemporal Dynamics of the Molecular Expression Pattern and Intercellular Interactions in the Glial Scar Response to Spinal Cord Injury.
Leilei GONG ; Yun GU ; Xiaoxiao HAN ; Chengcheng LUAN ; Chang LIU ; Xinghui WANG ; Yufeng SUN ; Mengru ZHENG ; Mengya FANG ; Shuhai YANG ; Lai XU ; Hualin SUN ; Bin YU ; Xiaosong GU ; Songlin ZHOU
Neuroscience Bulletin 2023;39(2):213-244
Nerve regeneration in adult mammalian spinal cord is poor because of the lack of intrinsic regeneration of neurons and extrinsic factors - the glial scar is triggered by injury and inhibits or promotes regeneration. Recent technological advances in spatial transcriptomics (ST) provide a unique opportunity to decipher most genes systematically throughout scar formation, which remains poorly understood. Here, we first constructed the tissue-wide gene expression patterns of mouse spinal cords over the course of scar formation using ST after spinal cord injury from 32 samples. Locally, we profiled gene expression gradients from the leading edge to the core of the scar areas to further understand the scar microenvironment, such as neurotransmitter disorders, activation of the pro-inflammatory response, neurotoxic saturated lipids, angiogenesis, obstructed axon extension, and extracellular structure re-organization. In addition, we described 21 cell transcriptional states during scar formation and delineated the origins, functional diversity, and possible trajectories of subpopulations of fibroblasts, glia, and immune cells. Specifically, we found some regulators in special cell types, such as Thbs1 and Col1a2 in macrophages, CD36 and Postn in fibroblasts, Plxnb2 and Nxpe3 in microglia, Clu in astrocytes, and CD74 in oligodendrocytes. Furthermore, salvianolic acid B, a blood-brain barrier permeation and CD36 inhibitor, was administered after surgery and found to remedy fibrosis. Subsequently, we described the extent of the scar boundary and profiled the bidirectional ligand-receptor interactions at the neighboring cluster boundary, contributing to maintain scar architecture during gliosis and fibrosis, and found that GPR37L1_PSAP, and GPR37_PSAP were the most significant gene-pairs among microglia, fibroblasts, and astrocytes. Last, we quantified the fraction of scar-resident cells and proposed four possible phases of scar formation: macrophage infiltration, proliferation and differentiation of scar-resident cells, scar emergence, and scar stationary. Together, these profiles delineated the spatial heterogeneity of the scar, confirmed the previous concepts about scar architecture, provided some new clues for scar formation, and served as a valuable resource for the treatment of central nervous system injury.
Mice
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Animals
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Gliosis/pathology*
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Cicatrix/pathology*
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Spinal Cord Injuries
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Astrocytes/metabolism*
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Spinal Cord/pathology*
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Fibrosis
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Mammals
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Receptors, G-Protein-Coupled