This study was aimed at investigating the effectiveness of various host nucleic acid removal and non-specific amplifica-tion techniques in animal tissue samples,to increase the accuracy of pathogen identification in tissue samples.Simulated samples were prepared with a mixture of mouse lung tissue homogenates and Klebsiella pneumoniae fluids,and processed with six host nucleic acid removal kits and three non-specific amplification techniques.The effectiveness of each method in removing host DNA and enriching nucleic acids of pathogenic microorganisms was evaluated through real-time fluorescence quantitative PCR and high-throughput se-quencing.For host nucleic acid removal techniques,the method of selective cleavage and quantitative degradation of host DNA(Com-plete5 kit)effectively decreased the host nucleic acid content in tissue samples and increased the relative abundance of pathogen nucleic acids.In contrast,the magnetic bead method for host DNA removal(Next microbiome DNA enrichment Kit kit)was less effec-tive.At lower pathogen concentrations(77 CFU/mL),the Vazyme kit was more effective than the other kits in removing host nucleic acids.Non-specific amplification techniques(MALBAC whole genome amplification,MDA isothermal amplification,and random primer amplification)were not applicable to tissue samples and were not effective in increasing the relative abundance of pathogen nucleic acids.Selective lysis and quantitative degradation of host DNA were suitable for processing tissue samples with high host back-ground and low pathogenic microorganism levels,whereas non-specific amplification methods were not applicable to tissue samples for pre-processing of macro-genome high-throughput sequencing.

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

This study was aimed at investigating the effectiveness of various host nucleic acid removal and non-specific amplifica-tion techniques in animal tissue samples,to increase the accuracy of pathogen identification in tissue samples.Simulated samples were prepared with a mixture of mouse lung tissue homogenates and Klebsiella pneumoniae fluids,and processed with six host nucleic acid removal kits and three non-specific amplification techniques.The effectiveness of each method in removing host DNA and enriching nucleic acids of pathogenic microorganisms was evaluated through real-time fluorescence quantitative PCR and high-throughput se-quencing.For host nucleic acid removal techniques,the method of selective cleavage and quantitative degradation of host DNA(Com-plete5 kit)effectively decreased the host nucleic acid content in tissue samples and increased the relative abundance of pathogen nucleic acids.In contrast,the magnetic bead method for host DNA removal(Next microbiome DNA enrichment Kit kit)was less effec-tive.At lower pathogen concentrations(77 CFU/mL),the Vazyme kit was more effective than the other kits in removing host nucleic acids.Non-specific amplification techniques(MALBAC whole genome amplification,MDA isothermal amplification,and random primer amplification)were not applicable to tissue samples and were not effective in increasing the relative abundance of pathogen nucleic acids.Selective lysis and quantitative degradation of host DNA were suitable for processing tissue samples with high host back-ground and low pathogenic microorganism levels,whereas non-specific amplification methods were not applicable to tissue samples for pre-processing of macro-genome high-throughput sequencing.

ObjectiveTo simulate the microstructure and mechanical properties of tendon tissue and promote its regeneration and repair, electrospinning technology was used to prepare L-polylactic acid (PLLA) fiber membranes loaded with different nano zinc oxide contents and with oriented structures. Physical and chemical characterization and biological performance evaluation were carried out to explore their effects on tendon cell proliferation and differentiation. MethodsPreparation of PLLA fiber scaffolds and PLLA/ZnO fiber scaffolds containing different mass fractions of nano ZnO was performed using electrospinning technology. The physicochemical properties of the scaffold were characterized by scanning electron microscopy, mechanical stretching, and EDS spectroscopy. The scaffold was co-cultured with mouse tendon cells to detect its biocompatibility and regulatory effects on cell differentiation behavior. ResultsThe fiber scaffolds were arranged in an oriented manner, and zinc elements were uniformly distributed in the fibers. The tensile strength and Young’s modulus of PLLA/0.1%ZnO fiber scaffolds were significantly higher than PLLA fiber scaffolds. The number of cells on the surface of PLLA/0.1%ZnO fiber scaffold was significantly higher than that of the PLLA group, and the activity was better; mouse tendon cells exhibit directional adhesion and growth along the fiber arrangement direction. ConclusionThe oriented PLLA/0.1%ZnO fiber scaffold had excellent physicochemical properties, which can significantly promote the oriented growth, proliferation and differentiation of tendon cells. It is expected to be used for tendon tissue regeneration and repair in the future.

Analyze the changes in phenolic components and gene expression profiles of Tetrastigma hemsleyanum leaves with supplemental blue light, and screen differentially expressed genes related to phenolic metabolism, providing a basis for improving the quality of T. hemsleyanum leaves. Using the leaves of T. hemsleyanum under supplemental blue light and visible light as research materials, the content of phenolic components such as neochlorogenic acid, chlorogenic acid, and 3-O-coumaroyl quinic acid was significantly increased by supplemental blue light. A total of 102 949 unigenes were obtained from the transcriptome, including 14 564 differentially expressed unigenes. They can be divided into 52 subclasses by gene ontology (GO) function, kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis showed that these differentially expressed unigenes were significantly enriched in phenolic metabolic pathways such as phenylpropane biosynthesis, flavonoid biosynthesis and isoflavone biosynthesis. A total of 63 differentially expressed unigenes were identified in the pathways related to the biosynthesis of phenolic cpmponents, including 19 key enzymes such as phenylalanine ammonia-lyase (PAL), cinnamyl-alcohol dehydrogenase (CAD), flavonol synthase (FLS), and so on. This study greatly enriched the genetic data information of T. hemsleyanum and laid a foundation for analyzing the mechanism of blue light promoting the biosynthesis of phenols and molecular breeding of T. hemsleyanum.

Tumor microenvironment (TME) is composed of endothelial cells, pericytes, immune cells, cancer-associated fibroblasts (CAFs), cancer stem cells (CSCs), extracellular matrix (ECM) and other components of the complex biological environment. TME interacts with the tumor cells through a large amount of signaling pathways, participates in the process of tumor progression, invasion, and metastasis. Hence, TME has become a potential therapeutic target for cancer treatment, exhibiting excellent therapeutic potential and research value in the field of cancer treatment. Currently, the novel nanotechnology has been widely applied in anticancer therapy, and nanotechnology-mediated drug delivery system is being explored to apply in TME modulation to inhibit tumor progression. Nanotechnology-mediated drug delivery has many advantages over traditional therapeutic modalities, including longer circulation times, improved bioavailability, and reduced toxicity. This review summarized the research of targeted nano-drug delivery based on TME regulation, including regulation strategies based on CSCs, CAFs, immune cells, ECM, tumor vascularization, exosomes, and microbiota. In addition, we summarized the advantages, opportunities, and challenges of TME regulation strategy compared with traditional treatment strategy, which provides a reference for the application of nano-drug delivery system based on TME regulation strategy in tumor precision therapy.

AIM: To analyze the changes of serum homocysteine(Hcy), vitamin B12(VitB12)and folic acid in the serum of patients with diabetic retinopathy(DR), and to explore their significance in the occurrence and development of DR.METHODS: A case-control study was designed. A total of 95 patients with DR(DR group), 94 patients with diabetes mellitus(DM group)treated in endgcrinology department and 87 patients with age-related cataract(normal control group)from the ophthalmology department of Shenzhen People's Hospital between July 2021 and January 2022 were selected. Fasting venous blood was collected and serum was separated. The concentration of Hcy in serum was detected by enzyme linked immunosorbent assay(ELISA), and chemiluminescence immunoassay was used to detect the concentration of VitB12 and folic acid. Pearson linear correlation analysis was used to evaluate the correlation between Hcy and clinical parameters. Multivariate linear regression analysis was used to evaluate the main factors which affect Hcy level. Receiver operating characteristic(ROC)curve was designed to analyze the diagnostic value of serum Hcy, VitB12 and folic acid in DR.RESULTS: The concentration of serum Hcy in DR group was 16.52±3.54 μmol/L, which was significantly higher than that in DM group(10.86±3.47 μmol/L)and control group(6.84±1.39 μmol/L; all P<0.05); The concentration of VitB12 in the serum of the control group was 501.79±108.95 pmol/L, which was higher than that in DM group(478.57±57.85 pmol/L)and DR group(455.88±181.49 pmol/L), but the difference was not statistically significant(P=0.054); The concentration of folic acid in serum of control group was 10.31±2.43 nmol/L, which was higher than that of DM group(9.94±1.90 nmol/L)and DR group(7.27±2.79 nmol/L), and the difference between DR group and DM group was statistically significant(P<0.05); In DR group, Hcy expression was weakly positively correlated with triglyceride and low density lipoprotein(r=0.208, P=0.043; r=0.240, P=0.019). Multivariate linear regression showed that low density lipoprotein was an important factor which affect the expression of Hcy in DR patients. ROC curve shows that Hcy has important value in the diagnosis of DR.CONCLUSIONS: Hcy, VitB12 and folic acid are differentially expressed in DR group, DM group and normal control group. Hcy may be involved in the pathogenesis of DR, and it has important value in the diagnosis of DR. In addition, low density lipoprotein is also an important factor which affects the expression of Hcy.

Objective:To construct the targeting evaluation method of traditional Chinese medicine （TCM） preparations based on supramolecular Qi chromatography theory， and to study the liver targeting effect of Bupleuri Radix on Pien Tze Huang. Method:The molecular connectivity index （MCI） was used to analyze the characteristics of imprinted template and liver targeting tendency of TCM mainly attributed to liver meridian and components of Pien Tze Huang， and combined with target dynamics and total statistical moment principle， aimed at the independent action characteristics of multi-component imprinted template of TCM， a method for evaluating the targeting of TCM preparations was established. Hepatoma rats in Pien Tze Huang group， Bupleuri Radix group， Pien Tze Huang+Bupleuri Radix group and blank group were tested and verified. Result:After the average value of MCI of TCM mainly attributed to liver meridian was deducted， the MCI similarity between Pien Tze Huang group and Bupleuri Radix group was 0.376 8， Pien Tze Huang+Bupleuri Radix group and Bupleuri Radix group was 0.988 2， so it was predicted that Bupleuri Radix could enhance the liver targeting of Pien Tze Huang. A system for evaluating the targeting of TCM compounds was established， including relative total uptake efficiency （RUE_T）， relative total concentration （RC_T）， relative imprinted tendency （RIT_T） and relative imprinted variance （RIV_T）. The RUE_T and RC_T of liver were the highest in all tissues （RUE_T=1.88>1，RC_T=2.30>1）， and the corresponding values of other tissues were all <1， indicating that Pien Tze Huang combined with Bupleuri Radix could increase its distribution in liver and enhance liver targeting. Except for plasma， the RIT_T and RIV_T of other tissues fluctuated around 1.0， indicating that targeted modification did not change imprinted tendency of Pien Tze Huang and had no significant effect on the types of components. Conclusion:Under the guidance of supramolecular Qi chromatography theory， a targeting evaluation parameter system can be established to characterize the multi-component imprinted effect of TCM preparations by MCI and total statistical moment parameters， so as to realize the evaluation of targeting of TCM preparations. The addition of Bupleuri Radix can increase the liver targeting of Pien Tze Huang.

Under the guidance of the theory of traditional Chinese medicine （TCM）， charcoal drugs are widely used in clinical treatment of various bleeding syndromes， in addition， they also have the effect in anti-diarrhea and anti-ulcer， but charcoal drugs are especially effective in stopping bleeding. According to the changes in the properties after processing， the hemostatic effect of charcoal drugs can be roughly divided into two categories. One is not used for hemostasis itself， but used for hemostasis after processing. The other is used for hemostasis itself， and the drug properties are changed or the hemostatic ability is enhanced after processing. By summarizing researches on historical evolution， processing mechanism and pharmacological effects of the commonly used hemostatic charcoal drugs， the author found that preservation or increase of active substances after processing was closely related to the hemostatic effect of charcoal drugs. The hemostatic mechanism mainly involves the influence of coagulation system and platelet function， etc. At the same time， combined with the theory of Qi chromatograph of TCM supramolecular， this paper puts forward the supramolecular research strategy on hemostatic mechanism of charcoal drugs， in order to provide reference for revealing the scientific connotation of charcoal drugs for hemostasis.