[Objective]To investigate the protective effect of overexpressed miRNA-200a&c on Angiostrongylus cantonensis-induced demyelinating optic neuritis in Balb/c mice.[Methods]SPF-grade Balb/c mice(2-3 weeks old)were divided into four groups:a normal group,and three A.cantonensis-infected groups at 7,14,and 21 days post-infection(dpi).Body weight,survival status,neurobehavioral scores,and visual function scores were recorded.Visual evoked potential(VEP)was used to detect visual damage,and transmission electron microscope(TEM)was applied to observe ocular structural changes.On day 7 post-infection,mice were stereotactically injected with exogenous miRNA-200a&c mimics into the lateral ventricle,and then divided into four groups:normal control,A.cantonensis-infected(AC-21 dpi),A.cantonensis-infected+negative control(AC+NC),and A.cantonensis-infected+overexpressed miRNA-200a&c(AC+miRNA-200a&c)mimics.VEP and TEM were repeated to assess visual damage and ocular structural changes.Immunofluorescence was performed to quantify retinal ganglion cells(RGCs)and oligodendrocytes(OLs)in the optic nerve.[Results]At 21 dpi,some mice exhibited complete eyelid closure(32.52±4.67)%or ocular atrophy(15.79±3.23)%,weight loss(P＜0.05)and altered consciousness.Neurobehavioral scores significantly decreased(P＜0.01),with a 68%decline in rotarod performance;some mice even displayed hemiplegia,slowed movement,ataxia,and directional deficits.Additionally,a subset of mice showed diminished sensory responses,unilateral vision loss(83%reduction in optokinetic threshold),and impaired visual function(P＜0.05).VEP results revealed a mild prolongation of latency in infected mice at 21 dpi(P＜0.05),predominantly affecting one eye.Following overexpression of miRNA-200a&c,compared with the 21 dpi group,VEP showed significantly shortened P1 latency(P＜0.05);TEM showed alleviated cytoplasmic swelling of RGCs,and improved compactness and uniformity of myelin sheath(P＜0.05);immunofluorescence showed increased numbers of RGCs and OLs with improved cell alignment(P＜0.05).[Conclusions]A.cantonensis infection induces demyelinating optic neuritis in Balb/c mice.Overexpression of miRNA-200a&c alleviates the resulting damage and ameliorates ocular injury.

ObjectiveTo investigate whether co-activated mesenchymal stem cells（MSCs） exert therapeutic effects against schistosomiasis by modulating macrophage polarization. MethodsTwenty adult male Balb/c mice were randomly divided into four groups： uninfected， infected， MSC-treated， and MSC^TLR4+IFN-γ-treated groups. The Schistosoma japonicum infection model was established via abdominal patch method with cercariae. At week 5 post-infection， praziquantel was administered orally for antiparasitic treatment. At week 6， mice received either MSCs treatments （with or without pre-activation） or no treatment. Body weight changes were monitored weekly. Hepatic pathological alterations were evaluated via HE and Masson staining. RT-qPCR was used to assess α-SMA and collagen （Col-I， Col-Ⅲ） mRNA levels to quantify fibrosis. The mRNA levels of hepatic inflammatory cytokines and matrix metalloproteinases（MMP） were analyzed to explore fibrotic mechanisms. The expressions of i-Nos and Arg-1 in liver tissues were detected by RT-qPCR， and the ratio of M1 or M2 macrophages was detected by immunofluorescence staining， aiming to analyze the correlation between MSCs treatment and macrophage polarization. An in vitro co-culture system validated direct MSC-macrophage interactions. ResultsCompared with the infected group， the MSC^TLR4+IFN-γ group exhibited increased body weight gain （P< 0.01）， reduced hepatic granulomatous lesion area （P< 0.001）， and decreased α-SMA， Col-I， and Col-Ⅲ mRNA levels （P< 0.01）. Additionally， the MSC^TLR4+IFN-γ group showed reduced TNF-α and IL-1β expression （P< 0.05）， as well as elevated MMP2， Mmp9， and MMP13 levels （P< 0.01）. The MSC^TLR4+IFN-γ group showed higher expression of M2 marker Arg-1 mRNA compared with the infection group （P < 0.001） ， while the expression of M1 marker i-Nos decreased （P< 0.05）. Immunofluorescence confirmed a lower i-Nos+ cell ratio （P< 0.05） and higher F4/80⁺CD206⁺ cell ratio （P< 0.000 1） in the MSC^TLR4+IFN-γ group compared with the infection group. In vitro co-culture experiments further demonstrated that MSC^TLR4+IFN-γ promoted Arg-1 expression， suppressed pro-inflammatory cytokine i-Nos and TNF-α levels， consistent with ELISA results. ConclusionsThis study reveals that TLR4 and IFN-γ co-activated MSCs alleviate Schistosoma japonicum-induced hepatic fibrosis， potentially through modulating macrophage polarization toward the M2 phenotype. This mechanism may suppress inflammation and enhance extracellular matrix degradation， providing a therapeutic strategy for schistosomiasis-associated liver fibrosis.

[Objective]To investigate the protective effect of overexpressed miRNA-200a&c on Angiostrongylus cantonensis-induced demyelinating optic neuritis in Balb/c mice.[Methods]SPF-grade Balb/c mice(2-3 weeks old)were divided into four groups:a normal group,and three A.cantonensis-infected groups at 7,14,and 21 days post-infection(dpi).Body weight,survival status,neurobehavioral scores,and visual function scores were recorded.Visual evoked potential(VEP)was used to detect visual damage,and transmission electron microscope(TEM)was applied to observe ocular structural changes.On day 7 post-infection,mice were stereotactically injected with exogenous miRNA-200a&c mimics into the lateral ventricle,and then divided into four groups:normal control,A.cantonensis-infected(AC-21 dpi),A.cantonensis-infected+negative control(AC+NC),and A.cantonensis-infected+overexpressed miRNA-200a&c(AC+miRNA-200a&c)mimics.VEP and TEM were repeated to assess visual damage and ocular structural changes.Immunofluorescence was performed to quantify retinal ganglion cells(RGCs)and oligodendrocytes(OLs)in the optic nerve.[Results]At 21 dpi,some mice exhibited complete eyelid closure(32.52±4.67)%or ocular atrophy(15.79±3.23)%,weight loss(P＜0.05)and altered consciousness.Neurobehavioral scores significantly decreased(P＜0.01),with a 68%decline in rotarod performance;some mice even displayed hemiplegia,slowed movement,ataxia,and directional deficits.Additionally,a subset of mice showed diminished sensory responses,unilateral vision loss(83%reduction in optokinetic threshold),and impaired visual function(P＜0.05).VEP results revealed a mild prolongation of latency in infected mice at 21 dpi(P＜0.05),predominantly affecting one eye.Following overexpression of miRNA-200a&c,compared with the 21 dpi group,VEP showed significantly shortened P1 latency(P＜0.05);TEM showed alleviated cytoplasmic swelling of RGCs,and improved compactness and uniformity of myelin sheath(P＜0.05);immunofluorescence showed increased numbers of RGCs and OLs with improved cell alignment(P＜0.05).[Conclusions]A.cantonensis infection induces demyelinating optic neuritis in Balb/c mice.Overexpression of miRNA-200a&c alleviates the resulting damage and ameliorates ocular injury.

Activating transcription factor 7(ATF7)is a stress-induced transcription factor,a member of the cAMP-response element binding protein(CREB)family,which is usually phosphorylated under stress to activate the transcription of target genes and regulate related biological processes.Based on the existing literature reports,we reviewed the role of ATF7 in regulating immunity,tu-mor and metabolism,which provides a theoretical basis for further research.

Currently, there is still no effective curative treatment for the development of late-stage liver fibrosis. Here, we have illustrated that TB001, a dual glucagon-like peptide-1 receptor/glucagon receptor (GLP-1R/GCGR) agonist with higher affinity towards GCGR, could retard the progression of liver fibrosis in various rodent models, with remarkable potency, selectivity, extended half-life and low toxicity. Four types of liver fibrosis animal models which were induced by CCl₄, α-naphthyl-isothiocyanate (ANIT), bile duct ligation (BDL) and Schistosoma japonicum were used in our study. We found that TB001 treatment dose-dependently significantly attenuated liver injury and collagen accumulation in these animal models. In addition to decreased levels of extracellular matrix (ECM) accumulation during hepatic injury, activation of hepatic stellate cells was also inhibited via suppression of TGF-β expression as well as downstream Smad signaling pathways particularly in CCl₄-and S. japonicum-induced liver fibrosis. Moreover, TB001 attenuated liver fibrosis through blocking downstream activation of pro-inflammatory nuclear factor kappa B/NF-kappa-B inhibitor alpha (NFκB/IKBα) pathways as well as c-Jun N-terminal kinase (JNK)-dependent induction of hepatocyte apoptosis. Furthermore, GLP-1R and/or GCGR knock-down results represented GCGR played an important role in ameliorating CCl₄-induced hepatic fibrosis. Therefore, TB001 can be used as a promising therapeutic candidate for the treatment of multiple causes of hepatic fibrosis demonstrated by our extensive pre-clinical evaluation of TB001.

Angiostrongylus cantonensis invades the central nervous system (CNS) of humans to induce eosinophilic meningitis and meningoencephalitis and leads to persistent headache, cognitive dysfunction, and ataxic gait. Infected mice (nonpermissive host), admittedly, suffer more serious pathological injuries than rats (permissive host). However, the pathological basis of these manifestations is incompletely elucidated. In this study, the behavioral test, histological and immunohistochemical techniques, and analysis of apoptotic gene expression, especially caspase-3, were conducted. The movement and motor coordination were investigated at week 2 post infection (PI) and week 3 PI in mice and rats, respectively. The cognitive impairs could be found in mice at week 2 PI but not in rats. The plaque-like lesion, perivascular cuffing of inflammatory cells, and dilated vessels within the cerebral cortex and hippocampus were more serious in mice than in rats at week 3 PI. Transcriptomic analysis showed activated extrinsic apoptotic pathway through increased expression of TNFR1 and caspase-8 in mice CNS. Immunohistochemical and double-labeling for NeuN and caspase-3 indicated the dramatically increased expression of caspase-3 in neuron of the cerebral cortex and hippocampus in mice but not in rats. Furthermore, western-blotting results showed high expression of cleaved caspase-3 proteins in mice but relatively low expression in rats. Thus, extrinsic apoptotic pathway participated in neuronal apoptosis might be the pathological basis of distinct behavioral dysfunctions in rodents with A. cantonensis infection. It provides the evidences of a primary molecular mechanism for the behavioral dysfunction and paves the ways to clinical diagnosis and therapy for A. cantonensis infection.
Angiostrongylus cantonensis* ; Angiostrongylus* ; Animals ; Apoptosis* ; Behavior Rating Scale ; Caspase 3 ; Caspase 8 ; Central Nervous System ; Cerebral Cortex ; Diagnosis ; Eosinophils ; Gait ; Gene Expression ; Headache ; Hippocampus ; Humans ; Meningitis ; Meningoencephalitis ; Mice ; Neurons* ; Rats ; Receptors, Tumor Necrosis Factor, Type I ; Rodentia*

Objective To compare the toxicity of outer membrane vesicles ( OMVs) secreted by Acinetobacter baumannii strains with different drug-resistance spectrums.Methods Four Acinetobacter baumannii strains with different drug-resistance spectrums were collected (strain 33, 3237, B29 and 10), and OMVs produced by these strains were extracted and purified.BCA assay was used to determine the protein concentrations, and RAW264.7 cells were incubated with different concentrations of OMVs for 24 h. Cell viability was measured with CCK-8 assay, and gene expression of tumor necrosis factor-alpha ( TNF-α) , interleukin-6 ( IL-6) , interleukin-1 beta ( IL-1β) , keratinocyte-derived chemokine ( KC) and macrophage inflammatory protein 2 (MIP-2) was assessed by quantitative real-time PCR.One-way ANOVA was used for data analysis.Results According to the result of drug susceptibility test, strain 10 was extensively drug-resistant Acinetobacter baumannii ( XDRAB ) strain, strain B29 was multi-drug resistance Acinetobacter baumannii (MDRAB) strain, while strain 33 and 3237 were non-MDRAB strains.After incubated with different concentrations of OMVs for 24 h, cell viability of RAW264.7 declined with the increase of OMVs concentrations.OMVs released from strain10, B29 and 3237 significantly lowered the cell viability at the concentration of 5 μg/mL, while the cytotoxicity of OMVs released from strain 33 was much weaker, and no remarkable decrease in cell viability was observed even at the concentration of 25 μg/mL.OMVs of all strains induced the release of TNF-α, IL-6, IL-1β, KC and MIP-2 in RAW264.7 cells, and the levels of theses cytokines were increased with the concentration of OMVs.Inflammatory response in cells incubated with OMVs from strain 33 was the weakest, while OMVs from strain 10 induced strongest inflammatory response.KC and MIP-2 levels were significantly higher in RAW264.7 cells incubated with OMVs from strain 10 with a concentration of 5 μg/mL than that incubated with OMVs from other strains ( F=19.094 and 19.032,P<0.05 or <0.01).Conclusions OMVs from Acinetobacter baumannii strains with different drug-resistance spectrums are of different toxicity.OMVs from XDRAB and MDRAB strains have higher toxicities and may induce stronger inflammatory response.

Objective To evaluate the teaching activity on public health courses from clinical medical students in our university in order to provide a scientific basis for improving the curriculum design and teaching reform. Methods The “Questionnaire on Teaching Evaluation in Public Health Courses”, including teaching attitude, teaching content, teaching methods and teaching effectiveness was designed, and a general investigation was conducted among the clinical medical students of five-year program (840 students) and eight-year program (278 students) in these three aspects to under-stand students' evaluation to the course, who had finished the public health courses, including Preven-tive Medicine, Medical Statistics and Epidemiology (hereinafter referred to as: statistics, epidemiology, prevention) in Sun Yat-sen University. Statistical analysis was made using SPSS 13.0 software. Data analysis methods contain descriptive analysis, T-test, ANOVA, LSD, SNK, hierarchical logistic regres-sion analysis, etc. Results The overall score of teaching evaluation is (4.04±0.60). Differences exist between the evaluation in the five-year medical students and the eight-year medical students. The P values were 0.000 (Medical Statistics), 0.269 (Epidemiology), 0.047 (Preventive Medicine). The com-parison of scores among the four dimensions shows: Teaching effectiveness < Teaching methods β' effectiveness. Conclusions Clinical Medical students' overall evaluation on the public health courses offered by this university was good. Teaching effectiveness and teaching methods still need improvement. Teaching contents are the most influential factor of overall teaching satisfaction, followed by teaching effectiveness.

Based on the concept of general education in higher education,Zhongshan school of medicine of Sun Yat-sen University launched general education course-‘ basic medicine introduction' to all non-medical undergraduates.Teaching contents,teaching methods and teaching effects of this course were explored and evaluated.By introducing basic medicine,the overall objective is to guide students to consciously maintain the mental and physical health and to stimulate students' thinking on the meaning of life.

Angiostrongylus cantonensis is a parasitic nematode that needs to develop in different hosts in different larval stages. Freshwater snails, such as Pomacea canaliculata, are the intermediate host, and rats are the definitive host. Periodic shedding of the cuticle (moulting) is an important biological process for the survival and development of the parasite in the intermediate and definitive hosts. However, there are few studies on the cuticle alterations between different stages of this parasite. In this study, we observed the ultrastructural appearance and changes of the cuticle of the 2nd/3rd stage larvae (L2/L3) and the 3rd/4th stage larvae (L3/L4) using a scanning electron microscope. We also first divided L2/L3 into late L2 and early L3. The late L2 lacked alae, but possessed a pull-chain-like fissure. Irregular alignment of spherical particles on the cuticle were noted compared to the L3. Alae appeared in the early L3. The old cuticle turned into a thin film-like structure which adhered to the new cuticle, and spherical particles were seen regularly arranged on the surface of this structure. Regular rectangular cavities were found on the surface of L3/L4. The caudal structure of L3/L4 was much larger than that of L3, but caudal inflation, such as seen in L4, was not observed. These results are the first to reveal the ultrastructural changes of the cuticle of A. cantonensis before and after moulting of L2/L3 and L3/L4.
Angiostrongylus cantonensis/*physiology/*ultrastructure ; Animals ; Larva/physiology/ultrastructure ; Microscopy, Electron, Scanning ; *Molting