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.

Objective To develop and validate a transgenic mouse model enabling specific and inducible optogenetic activation of oligodendrocyte precursor cells(OPCs).Methods A conditional allele for the photosensitive opsin chicken opsin 5(cOpn5)(Rosa26-LSL-cOpn5)was generated using CRISPR/Cas9 technology.These mice were subsequently crossed with NG2-CreERT transgenic mice to produce NG2-CreERT;cOpn5 animals.In this model,tamoxifen administration induces Cre-mediated recombination,leading to specific expression of cOpn5 in NG2-positive OPCs.The specificity and efficiency of cOpn5 expression in OPCs were confirmed by immunofluorescent staining.Functional validation of light-induced OPC activation was performed by using calcium imaging in acute brain slices after stimulation with 470 nm blue light.Results Immunofluorescence analysis confirmed robust and specific expression of cOpn5 within NG2-positive OPCs in the brains of tamoxifen-treated NG2-CreERT;cOpn5 mice.Crucially,calcium imaging of acute brain slices from these mice demonstrated a significant increase in intracellular calcium levels in cOpn5-expressing OPCs upon stimulation with 470 nm blue light,indicating successful optogenetic activation.Conclusion We have successfully generated and validated a novel transgenic mouse model(NG2-CreERT;cOpn5)that permits specific and inducible optogenetic activation of OPCs.This model provides a novel tool for subsequent in vivo studies of the role and regulating mechanisms of OPCs in the central nervous system.

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.

Objective To develop and validate a transgenic mouse model enabling specific and inducible optogenetic activation of oligodendrocyte precursor cells(OPCs).Methods A conditional allele for the photosensitive opsin chicken opsin 5(cOpn5)(Rosa26-LSL-cOpn5)was generated using CRISPR/Cas9 technology.These mice were subsequently crossed with NG2-CreERT transgenic mice to produce NG2-CreERT;cOpn5 animals.In this model,tamoxifen administration induces Cre-mediated recombination,leading to specific expression of cOpn5 in NG2-positive OPCs.The specificity and efficiency of cOpn5 expression in OPCs were confirmed by immunofluorescent staining.Functional validation of light-induced OPC activation was performed by using calcium imaging in acute brain slices after stimulation with 470 nm blue light.Results Immunofluorescence analysis confirmed robust and specific expression of cOpn5 within NG2-positive OPCs in the brains of tamoxifen-treated NG2-CreERT;cOpn5 mice.Crucially,calcium imaging of acute brain slices from these mice demonstrated a significant increase in intracellular calcium levels in cOpn5-expressing OPCs upon stimulation with 470 nm blue light,indicating successful optogenetic activation.Conclusion We have successfully generated and validated a novel transgenic mouse model(NG2-CreERT;cOpn5)that permits specific and inducible optogenetic activation of OPCs.This model provides a novel tool for subsequent in vivo studies of the role and regulating mechanisms of OPCs in the central nervous system.

Spinal surgical site infection (SSI), especially deep SSI after internal fixation is difficult in treatment, with long course of disease and poor prognosis. At present, there are many controversies in the diagnosis and treatment of spinal SSI, with unsatisfactory overall efficacy of its diagnosis and treatment. Besides, no diagnosis and treatment guideline based on evidence-based medicine has been in existence. To this end, the Spinal Infection Group of the Orthopedic Branch of the Chinese Medical Doctor Association and the Spinal Infection Group of the Spinal Surgery Branch of the Chinese Rehabilitation Medicine Association jointly organized relevant experts to formulate Evidence-based clinical guideline for the diagnosis and treatment of surgical site infection in spinal trauma ( version 2024) based on an evidence-based approach. A total of 10 recommendations were proposed on the diagnosis and treatment of spinal SSI, so as to provide a clinical reference for the diagnosis and treatment of spinal SSI.

Spinal surgical site infection (SSI), especially deep SSI after internal fixation is difficult in treatment, with long course of disease and poor prognosis. At present, there are many controversies in the diagnosis and treatment of spinal SSI, with unsatisfactory overall efficacy of its diagnosis and treatment. Besides, no diagnosis and treatment guideline based on evidence-based medicine has been in existence. To this end, the Spinal Infection Group of the Orthopedic Branch of the Chinese Medical Doctor Association and the Spinal Infection Group of the Spinal Surgery Branch of the Chinese Rehabilitation Medicine Association jointly organized relevant experts to formulate Evidence-based clinical guideline for the diagnosis and treatment of surgical site infection in spinal trauma ( version 2024) based on an evidence-based approach. A total of 10 recommendations were proposed on the diagnosis and treatment of spinal SSI, so as to provide a clinical reference for the diagnosis and treatment of spinal SSI.

OBJECTIVE: To investigate the effects of methionine restriction on proliferation, cell cycle and apoptosis of human acute leukemia cells. METHODS: Cell Counting Kit-8 (CCK-8) assay was used to detect the effect of methionine restriction on HL-60 and Jurkat cells proliferation. The effect of methionine restriction on cell cycle of HL-60 and Jurkat cells was examined by PI staining. Annexin V-FITC / PI double staining was applied to detect apoptosis of HL-60 and Jurkat cells following methionine restriction. The expression of cell cycle-related proteins cyclin B1, CDC2 and apoptosis-related protein Bcl-2 was evaluated by Western blot assay. RESULTS: Methionine restriction significantly inhibited the proliferation of HL-60 and Jurkat cells in a time-dependent manner (HL-60: r =0.7773, Jurkat: r =0.8725), arrested the cells at G2/M phase (P < 0.001), and significantly induced apoptosis of HL-60 and Jurkat cells (HL-60: P < 0.001; Jurkat: P < 0.05). Furthermore, Western blot analysis demonstrated that methionine restriction significantly reduced the proteins expression of Cyclin B1 (P < 0.05), CDC2 (P < 0.01) and Bcl-2 (P < 0.001) in HL-60 and Jurkat cells. CONCLUSION Acute leukemia cells HL-60 and Jurkat exhibit methionine dependence. Methionine restriction can significantly inhibit the proliferation, promote cell cycle arrest and induce apoptosis of HL-60 and Jurkat cells, which suggests that methionine restriction may be a potential therapeutic strategy for acute leukemia.
Humans ; Cyclin B1/pharmacology* ; Cell Proliferation ; Methionine/pharmacology* ; Cell Cycle ; Apoptosis ; Leukemia, Myeloid, Acute ; Cell Division ; Cell Cycle Proteins ; Jurkat Cells ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; HL-60 Cells

Sanhan Huashi formula(SHF) is the intermediate of a newly approved traditional Chinese medicine(TCM) Sanhan Huashi Granules for the treatment of COVID-19 infection. The chemical composition of SHF is complex since it contains 20 single herbal medicines. In this study, UHPLC-Orbitrap Exploris 240 was used to identify the chemical components in SHF and in rat plasma, lung and feces after oral administration of SHF, and heat map was plotted for characterizing the distribution of the chemical components. Chromatographic separation was conducted on a Waters ACQUITY UPLC BEH C_(18)(2.1 mm×100 mm, 1.7 μm) using 0.1% formic acid(A)-acetonitrile(B) as mobile phases in a gradient elution. Electrospray ionization(ESI) source was used to acquire data in positive and negative mode. By reference to quasi-molecular ions and MS/MS fragment ions and in combination with MS spectra of reference substances and compound information in literature reports, 80 components were identified in SHF, including 14 flavonoids, 13 coumarins, 5 lignans, 12 amino-compounds, 6 terpenes and 30 other compounds; 40 chemical components were identified in rat plasma, 27 in lung and 56 in feces. Component identification and characterization of SHF in vitro and in vivo lay foundations for disclosure of its pharmacodynamic substances and elucidation of the scientific connotation.
Rats ; Animals ; Tandem Mass Spectrometry ; Chromatography, High Pressure Liquid/methods* ; Drugs, Chinese Herbal/chemistry* ; COVID-19 ; Lignans

Intermittent hypoxia (IH) is an important pathophysiological feature of obstructive sleep apnea (OSA), but its molecular mechanism is still unclear. We aim to investigate the role of endogenous competing endogenous RNA (ceRNA) regulatory network in the development of IH in OSA rats. An intermittent hypoxic rat model of OSA was constructed by hypoxic and reoxygenation cycles. CircRNAs and mRNAs were detected in rat bronchial tissues, and 230 up-regulated and 181 down-regulated circRNAs and 1238 up-regulated and 608 down-regulated mRNAs were analyzed and screened. The results of Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the differential circRNAs and mRNAs suggested that they were mainly associated with metabolic pathways and PI3K-Akt signaling pathways. The key circRNAs (the top six circRNAs with the largest differences) were further validated by quantitative real-time polymerase chain reaction (qRT-PCR), chr9:52042693| 52047844 and chr4: 64889575|64899587 were expressed in bronchial tissues consistent with the sequencing results, which were used to further construct the ceRNA regulatory network. Four potential ceRNA regulatory networks were identified by TargetScan and miRanda database, combined with the results of differential circRNA and mRNA. The expression of molecules in the four potential ceRNA regulatory networks was detected by qRT-PCR in bronchial and lung tissues, and the results suggested that the expression of this regulatory network, chr9:52042693|52047844-miR-351-5p-Pten, was consistent with the sequencing results. The findings indicate that chr9:52042693 | 52047844-miR-351-5p-Pten may be involved in the development and progression of obstructive sleep apnea syndrome through a ceRNA mechanism.

Objective: To analyze the clinical epidemiological characteristics including composition of pathogens , clinical characteristics, and disease prognosis acute bacterial meningitis (ABM) in Chinese children. Methods: A retrospective analysis was performed on the clinical and laboratory data of 1 610 children <15 years of age with ABM in 33 tertiary hospitals in China from January 2019 to December 2020. Patients were divided into different groups according to age,<28 days group, 28 days to <3 months group, 3 months to <1 year group, 1-<5 years of age group, 5-<15 years of age group; etiology confirmed group and clinically diagnosed group according to etiology diagnosis. Non-numeric variables were analyzed with the Chi-square test or Fisher's exact test, while non-normal distrituction numeric variables were compared with nonparametric test. Results: Among 1 610 children with ABM, 955 were male and 650 were female (5 cases were not provided with gender information), and the age of onset was 1.5 (0.5, 5.5) months. There were 588 cases age from <28 days, 462 cases age from 28 days to <3 months, 302 cases age from 3 months to <1 year of age group, 156 cases in the 1-<5 years of age and 101 cases in the 5-<15 years of age. The detection rates were 38.8% (95/245) and 31.5% (70/222) of Escherichia coli and 27.8% (68/245) and 35.1% (78/222) of Streptococcus agalactiae in infants younger than 28 days of age and 28 days to 3 months of age; the detection rates of Streptococcus pneumonia, Escherichia coli, and Streptococcus agalactiae were 34.3% (61/178), 14.0% (25/178) and 13.5% (24/178) in the 3 months of age to <1 year of age group; the dominant pathogens were Streptococcus pneumoniae and the detection rate were 67.9% (74/109) and 44.4% (16/36) in the 1-<5 years of age and 5-<15 years of age . There were 9.7% (19/195) strains of Escherichia coli producing ultra-broad-spectrum β-lactamases. The positive rates of cerebrospinal fluid (CSF) culture and blood culture were 32.2% (515/1 598) and 25.0% (400/1 598), while 38.2% (126/330)and 25.3% (21/83) in CSF metagenomics next generation sequencing and Streptococcus pneumoniae antigen detection. There were 4.3% (32/790) cases of which CSF white blood cell counts were normal in etiology confirmed group. Among 1 610 children with ABM, main intracranial imaging complications were subdural effusion and (or) empyema in 349 cases (21.7%), hydrocephalus in 233 cases (14.5%), brain abscess in 178 cases (11.1%), and other cerebrovascular diseases, including encephalomalacia, cerebral infarction, and encephalatrophy, in 174 cases (10.8%). Among the 166 cases (10.3%) with unfavorable outcome, 32 cases (2.0%) died among whom 24 cases died before 1 year of age, and 37 cases (2.3%) had recurrence among whom 25 cases had recurrence within 3 weeks. The incidences of subdural effusion and (or) empyema, brain abscess and ependymitis in the etiology confirmed group were significantly higher than those in the clinically diagnosed group (26.2% (207/790) vs. 17.3% (142/820), 13.0% (103/790) vs. 9.1% (75/820), 4.6% (36/790) vs. 2.7% (22/820), χ²=18.71, 6.20, 4.07, all P<0.05), but there was no significant difference in the unfavorable outcomes, mortility, and recurrence between these 2 groups (all P>0.05). Conclusions: The onset age of ABM in children is usually within 1 year of age, especially <3 months. The common pathogens in infants <3 months of age are Escherichia coli and Streptococcus agalactiae, and the dominant pathogen in infant ≥3 months is Streptococcus pneumoniae. Subdural effusion and (or) empyema and hydrocephalus are common complications. ABM should not be excluded even if CSF white blood cell counts is within normal range. Standardized bacteriological examination should be paid more attention to increase the pathogenic detection rate. Non-culture CSF detection methods may facilitate the pathogenic diagnosis.
Adolescent ; Brain Abscess ; Child ; Child, Preschool ; Escherichia coli ; Female ; Humans ; Hydrocephalus ; Infant ; Infant, Newborn ; Male ; Meningitis, Bacterial/epidemiology* ; Retrospective Studies ; Streptococcus agalactiae ; Streptococcus pneumoniae ; Subdural Effusion ; beta-Lactamases