Epidural spinal cord stimulation (eSCS) represents an emerging neuromodulation technology that ameliorates motor dysfunction in patients with spinal cord injury, Parkinson's disease, and stroke by activating sensory afferent fibers, enhancing spinal cord neural network integration, optimizing brain-spinal cord information transmission, and inducing neural plasticity. This article reviews the mechanism, electrode implantation, and stimulation parameter of eSCS, and application of eSCS in spinal cord injury, Parkinson's disease, and stroke, aiming to provide valuable insight for its clinical implementation.

The establishment of mouse models is critical for discovering the biological targets of tumorigenesis and cancer development, preclinical trials of targeted drugs, and formulation of personalized therapeutic regimens. Currently, the patient-derived xenograft (PDX) model is considered a reliable animal tumor model because of its ability to retain the characteristics of the primary tumor at the histopathological, molecular, and genetic levels, and to preserve the tumor microenvironment. The application of the PDX model has promoted in-depth research on tumors in recent years, focusing on drug development, tumor target discovery, and precise treatment of patients. However, there are still some common questions. This review introduces the latest research progress and common questions regarding tumors with high mortality rates, focusing on their application in targeted drug screening and the formulation of personalized medical strategies. The challenges faced, improvement methods, and future development of the PDX model in tumor treatment applications are also discussed. This article provides technical guidance and comprehensive expectations for anti-cancer drug screening and clinical personalized therapy.

BACKGROUND:Mammary stem cells are vital for the development and homeostasis of mammary gland tissue.The occurrence of breast cancer has a close relationship with the mammary stem cells.Recent studies have shown that Hopx,as an important transcriptional regulator of morphogenesis and cell differentiation,has been confirmed to be expressed in a variety of adult stem cells such as nerves,intestines,hair follicles and lungs.However,its role in mammary stem cells has not been reported so far.OBJECTIVE:To investigate whether Hopx expression marks mammary stem cells.METHODS:(1) Female Hopx-LacZ transgenic mice aged 8 weeks were selected to detect the background expression of Hopx in breast tissue by β-galactosidase staining.(2) Female wild-type mice at 4,6,and 8 weeks of age and 14.5 days of gestation were selected for whole-tissue magenta staining and K14 and K8 immunofluorescence staining,respectively.(3) Female Hopx-CreERT2;Rosa26LacZ transgenic mice aged 8 weeks and 17.5 days of gestation were selected and stained with breast β-galactosidase.(4) The 4-week-old female Hopx-CreERT2;Rosa26LacZ transgenic mice were selected.The Cre/loxp system was activated by intraperitoneal injection of tamoxifen (once every other day,three times),and breast β-galactosidase staining was performed 4 weeks after injection.The 8-week-old female Hopx-CreERT2;Rosa26LacZ transgenic mice were selected.The Cre/loxp system was activated by intraperitoneal injection of tamoxifen (once every other day,three times),and breast β-galactosidase staining was performed 4 and 10 weeks after the last injection.(5) Female Hopx-CreERT2;Rosa26LacZ transgenic mice aged 8 weeks were selected.The Cre/loxp system was activated by intraperitoneal injection of tamoxifen (once every other day,three times).Hopx-CreERT2;Rosa26LacZ transgenic mice were pregnant 2 weeks after injection.The mammary tissue of mice at 17.5 days of the first pregnancy and 17.5 days of the third pregnancy was stained with β-galactosidase.RESULTS AND CONCLUSION:(1) The results of β-galactosidase staining showed that the mammary ducts of Hopx-LacZ transgenic mice at 8 weeks of age did contain Hopx-positive cells and were located in the basal epithelia,with a small number.(2) Whole-mount staining of mammary glands and immunofluorescence staining results exhibited that the mammary glands of mice had different characteristics with corresponding developmental stages such as puberty,maturity,and pregnancy,and underwent a series of complex epithelial remodeling processes.(3) The results of β-galactosylase staining showed that Hopx-labeled positive cells in the mammary duct of Hopx-CreERT2;Rosa26LacZ transgenic mice at 17.5 days of gestation increased compared with female Hopx-CreERT2;Rosa26LacZ transgenic mice at 8 weeks of age.(4) The results of β-galactosylase staining showed that the Hopx-labeled positive cells in the mammary glands of 4-and 8-week-old female Hopx-CreERT2;Rosa26LacZ transgenic mice after tamoxifen injection were located in the basal epithelium with a small number.(5) The results of β-galactosidase staining showed that Hopx-labeled positive cells in the mammary glands of mice at 17.5 days of the first and third gestation were located in the basal epithelia around the alveoli,and the number of Hopx-labeled positive cells at 17.5 days of the third gestation was more.(6) In conclusion,Hopx reporter-marked basal epithelial cells belong to dormant mammary stem cells,which are responsible for the growth of the mammary glands during pregnancy and contribute to acinar formation.

BACKGROUND:Mammary stem cells are vital for the development and homeostasis of mammary gland tissue.The occurrence of breast cancer has a close relationship with the mammary stem cells.Recent studies have shown that Hopx,as an important transcriptional regulator of morphogenesis and cell differentiation,has been confirmed to be expressed in a variety of adult stem cells such as nerves,intestines,hair follicles and lungs.However,its role in mammary stem cells has not been reported so far.OBJECTIVE:To investigate whether Hopx expression marks mammary stem cells.METHODS:(1) Female Hopx-LacZ transgenic mice aged 8 weeks were selected to detect the background expression of Hopx in breast tissue by β-galactosidase staining.(2) Female wild-type mice at 4,6,and 8 weeks of age and 14.5 days of gestation were selected for whole-tissue magenta staining and K14 and K8 immunofluorescence staining,respectively.(3) Female Hopx-CreERT2;Rosa26LacZ transgenic mice aged 8 weeks and 17.5 days of gestation were selected and stained with breast β-galactosidase.(4) The 4-week-old female Hopx-CreERT2;Rosa26LacZ transgenic mice were selected.The Cre/loxp system was activated by intraperitoneal injection of tamoxifen (once every other day,three times),and breast β-galactosidase staining was performed 4 weeks after injection.The 8-week-old female Hopx-CreERT2;Rosa26LacZ transgenic mice were selected.The Cre/loxp system was activated by intraperitoneal injection of tamoxifen (once every other day,three times),and breast β-galactosidase staining was performed 4 and 10 weeks after the last injection.(5) Female Hopx-CreERT2;Rosa26LacZ transgenic mice aged 8 weeks were selected.The Cre/loxp system was activated by intraperitoneal injection of tamoxifen (once every other day,three times).Hopx-CreERT2;Rosa26LacZ transgenic mice were pregnant 2 weeks after injection.The mammary tissue of mice at 17.5 days of the first pregnancy and 17.5 days of the third pregnancy was stained with β-galactosidase.RESULTS AND CONCLUSION:(1) The results of β-galactosidase staining showed that the mammary ducts of Hopx-LacZ transgenic mice at 8 weeks of age did contain Hopx-positive cells and were located in the basal epithelia,with a small number.(2) Whole-mount staining of mammary glands and immunofluorescence staining results exhibited that the mammary glands of mice had different characteristics with corresponding developmental stages such as puberty,maturity,and pregnancy,and underwent a series of complex epithelial remodeling processes.(3) The results of β-galactosylase staining showed that Hopx-labeled positive cells in the mammary duct of Hopx-CreERT2;Rosa26LacZ transgenic mice at 17.5 days of gestation increased compared with female Hopx-CreERT2;Rosa26LacZ transgenic mice at 8 weeks of age.(4) The results of β-galactosylase staining showed that the Hopx-labeled positive cells in the mammary glands of 4-and 8-week-old female Hopx-CreERT2;Rosa26LacZ transgenic mice after tamoxifen injection were located in the basal epithelium with a small number.(5) The results of β-galactosidase staining showed that Hopx-labeled positive cells in the mammary glands of mice at 17.5 days of the first and third gestation were located in the basal epithelia around the alveoli,and the number of Hopx-labeled positive cells at 17.5 days of the third gestation was more.(6) In conclusion,Hopx reporter-marked basal epithelial cells belong to dormant mammary stem cells,which are responsible for the growth of the mammary glands during pregnancy and contribute to acinar formation.

Epidural spinal cord stimulation (eSCS) represents an emerging neuromodulation technology that ameliorates motor dysfunction in patients with spinal cord injury, Parkinson's disease, and stroke by activating sensory afferent fibers, enhancing spinal cord neural network integration, optimizing brain-spinal cord information transmission, and inducing neural plasticity. This article reviews the mechanism, electrode implantation, and stimulation parameter of eSCS, and application of eSCS in spinal cord injury, Parkinson's disease, and stroke, aiming to provide valuable insight for its clinical implementation.

Objective To study the injury risk and fatigue status of firefighters with different training postures under load-bearing conditions to reduce the occurrence of physical injuries and occupational diseases.Methods First,a questionnaire was administered to investigate the training injury conditions of firefighters in a fire-rescue brigade.Considering the exercise fatigue factor,which accounts for the highest proportion of injury causes,lower back analysis,static strength analysis,fatigue analysis,comfort analysis,and other human factor analysis tools in Jack software were used to analyze four common firefighter water-shooting training postures.Training postures while climbing a five-storey building with loads and a hooked ladder were also simulated.Results Injury caused by exercise fatigue accounted for 69.8%of injuries and was the most important injury-causing factor.The risk of knee and ankle joint injuries increased in all four water-shooting postures.The comfort levels of the four water-shooting postures from high to low were shoulder,standing,kneeling,and lying postures.For the entire dynamic training process,while climbing the five-storey building with loads and climbing the hooked ladder,firefighters did not have an increased risk of lower back injury but had an increased risk of ankle and knee joint injuries.Conclusions Some training postures are uncomfortable for firefighters,and they experience body discomfort during firefighting training with loads,thereby increasing injury risk.These results provide scientific references for the prevention and reduction of firefighter training injuries,and the formulation of reasonable training plans and targeted protective measures.

ObjectiveTo provide technical support for the molecular surveillance of pathogenic bacteria strains carrying mobile colistin resistance-1 （mcr⁃1） gene isolate from inlet of wastewater treatment plants （WWTP）. MethodsThe Enterobacteriaceae strains carrying mcr⁃1 resistance gene isolate from inlet of WWTP during April 1 to June 30， 2023 in Shanghai were cultured on blood-rich and SS culture medium and were identified using a mass spectrometry analyzer. The mcr⁃1 gene and copy number were detected by real-time fluorescence quantitative PCR. Drug susceptibility test was performed by microbroth dilution method. The copy numbers of Escherichia coli carrying mcr⁃1 gene isolated from wastewater and human fecel were statistically analyzed by SPSS 25.0. ResultsA total of 14 strains carrying the mcr⁃1 gene were isolated from 49 WWTP samples， and the positive isolation rate was 28.6%， including 12 non-diarrheal E. coli strains and 2 Klebsiella pneumoniae strains. The drug susceptibility results showed that all 14 strains were multi-drug resistant bacteria. They were all sensitive to imipenem and tigecycline， but were ampicillin- and cefazolin-resistant. There was no significant difference in the copy number between human-sourced diarrheal E. coli and wastewater-sourced non-diarrheal E. coli （t=0.647， P>0.05）. ConclusionThe isolation and identification of strains carrying the mcr⁃1 gene from inlet of WWTP samples were firstly established in Shanghai. The multi-drug resistance among the isolated strains is severe. To effectively prevent and control the spread of colistin-resistant bacteria， more attention should be paid to the surveillance of mcr⁃1 gene.

Objective:To understand the infection status, epidemiological characteristics and drug resistance of Diarrheagenic Escherichia coli (DEC) in Shanghai and provide evidence for the disease surveillance. Methods:The epidemiological data of diarrhea cases in Shanghai from 2016 to 2022 were collected from Shanghai Diarrhea Comprehensive Surveillance System, and stool samples were collected from the cases for DEC detection. The drug resistance data was obtained from Chinese Pathogen Identification Network. Statistical analysis was conducted by using χ2 and fisher test. Results:In 24 883 diarrhea cases detected during 2016-2022, the DEC positive rate was 9.13% (2 271/24 883), the single DEC positive rate was 8.83% (2 197/24 883) and the mixed DEC positive rate was 0.30% (74/24 883). The main type of DEC was Enterotoxigenic Escherichia coli (ETEC) [4.33% (1 077/24 883)]. The DEC positive rate was highest in people aged ≤5 years 18.48% (22/119). The annual peak of DEC positive rate was observed during July - September [5.91% (1 470/24 883)]. The DEC positive rate were 9.47% (554/5 847) and 9.02% (1 717/19 036) in urban area and in suburbs, respectively, Enteroaggregative Escherichia coli (EAEC) [3.98% (233/5 847)] and ETEC [4.56% (868/19 036)] were mainly detected. From 2016 to 2019, the DEC positive rate was 9.42% (1 821/19 330), while it was 8.10% (450/5 553) from 2020 to 2022, the main DEC types were ETEC (4.87%, 941/19 330) and EAEC (4.70%, 261/5 553). The multi-drug resistance rate was 40.21% (618/1 537). The top three antibiotics with high drug resistance rates were ampicillin [64.74% (995/1 537)], nalidixic acid [58.49% (899/1 537)] and tetracycline [45.09% (693/1 537)]. Conclusions:Compared with 2016- 2019, a decrease in DEC detection rate was observed during 2020-2022, and the main type of DEC detected shifted from ETEC to EAEC. The prevalence of multi-drug resistance was severe. Therefore, it is necessary to further strengthen the surveillance for DEC drug resistance and standardize the use of clinical antibiotics.

Objective:To investigate the role of hepatitis B virus X protein (HBx) in glomerular podocyte immune disorder and its regulatory mechanism.Methods:Fourteen 6-week-old male hepatitis B virus (HBV) transgenic (HBV-Tg) mice were selected, and age-matched wild type (WT) mice were as controls. They were fed to different weeks, and 24 h urinary protein, blood biochemistry, renal pathology and podocyte changes under electron microscope were detected. The expression of HBx and the infiltration of immune cells in kidney tissue of HBV-Tg mice were observed by immunohistochemistry. Human podocyte cell line was transfected with pcDNA3.1/myc-HBx plasmid, and the localization of HBx and Nephrin in podocytes was detected by immunofluorescence. The expression of major histocompatibility complex Ⅱ (MHC-Ⅱ) and co- stimulatory molecule CD40 on the cell surface was detected by flow cytometry. The contents of multiple cytokines in cell culture supernatants were determined by enzyme-linked immunosorbent assay. Transcriptome sequencing (RNA-seq) was used to screen the downstream related genes regulated by HBx, and real-time quantitative PCR was used to verify their expressions. After overexpression or silencing of Notch1 gene with overexpressed plasmids or short hairpin RNA (shRNA) in podocytes, the effects on the expression of immune molecules and cytokines secretion was observed. The Notch receptor inhibitor N-[N-(3, 5-difluorophenyl-l- alanyl)]-(s)-phenylglycine tert-butyl ester (DAPT) was used to block Notch1 signaling pathway in HBV-Tg mice, and then blood biochemistry, renal pathological changes and infiltration of immune cells in kidney tissue were observed. Results:Twenty-four-hour urine protein, serum creatinine and urea nitrogen levels were markedly increased (all P<0.05) and renal pathological injury was significantly aggravated in HBV-Tg mice than those in WT mice. Also, HBx was up-regulated and immune cells infiltrated in the glomerulus of HBV-Tg mice. After transfection with HBx in podocytes, the expression of MHC-Ⅱ and CD40 on the cellular surface was up-regulated (all P<0.05), the contents of monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor -α (TNF-α) and interleukin (IL)-1β in the supernatants were increased (all P<0.05), and the secretion of IL-4 and interferon γ (IFN-γ) was unbalanced. RNA-seq screened downstream genes of HBx, such as Notch1, PLA2R, TLR4, etc; and further confirmed that HBx could promote the up-regulation of Notch1 mRNA and protein (all P<0.05). After over-expression of Notch1 gene, HBx-induced expression of MHC-Ⅱ and CD40 on the cellular surface was significantly up-regulated (all P<0.05), and the contents of MCP-1, TNF-α and IL-1β in the supernatants were obviously increased (all P<0.05), and the imbalance of IL-4/IFN-γ was further aggravated. After Notch1 gene silencing, the above results showed the opposite changes. In vivo, the results indicated that serum creatinine levels were obviously decreased (all P<0.05), renal pathological injury and immune cell infiltration were significantly alleviated in HBV-Tg+DAPT group than those in HBV-Tg+DMSO group. Conclusions:HBx protein can promote the up-regulation of Notch1 signaling pathway in podocytes. And Notch1 signaling pathway promotes the expression of immune molecules on the surface of podocytes and regulates the imbalance of cytokines, then causes glomerular injury and dysfunction of immune microenvironment.

ObjectiveTo understand the presence of virulence genes， molecular typing characteristics， and antibiotic sensitivity of enteroaggregative Escherichia coli （EAEC） in children with diarrhea in Shanghai， so as to provide a scientific basis for EAEC monitoring and standardized treatment of EAEC infection. MethodsEAEC strains isolated from children （≤5 years old） with diarrhea in six districts of Shanghai were collected as the study subjects. EAEC virulence genes were detected by real-time fluorescence quantitative PCR， molecular typing was performed by pulsed-field gel electrophoresis （PFGE）， and drug susceptibility tests were conducted using the microbroth dilution method. χ² test and two independent samples t-test were used to compare the differences in virulence genes and antibiotic resistance between suburban and urban EAEC strains. ResultsFrom 2019 to 2021， the overall detection rates of gene aggR， pic and astA of 59 EAEC were 30.5%， 50.8%， and 57.6%， respectively. There was no significant difference in the detection rates of virulence genes between suburban and urban EAEC strains （P>0.05）. PFGE analysis revealed that only two EAEC strains belonged to the same PFGE pattern and were collected from the same hospital， and the overall PFGE patterns were polymorphic. EAEC showed susceptibility to imipenem and colistin E， and the resistance rates to sulfamethoxazole （SXT）， ampicillin （AMP）， nalidixic acid （NAL）， and tetracycline （93.1%， 79.3%， 63.8%， and 58.6%， respectively） were higher than 50.0%. The antibiotic resistance rates of cefazolin （CFZ）， cefotaxime （CTX）， and ciprofloxacin （CIP） were significantly different between EAEC strains from suburban and urban areas （P<0.05）. A total of 47 strains exhibited multi-drug resistance， with the most common resistance spectrum being AMP-SXT-NAL. There was no statistically significant difference in the number of multidrug-resistant EAEC strains between suburban and urban areas （P>0.05）. ConclusionThe EAEC virulence gene assemblages in children with diarrhea in the six districts of Shanghai are diverse， and the molecular typing patterns are relatively scattered， indicating possible cross-infection of homologous strains. Multi-drug resistance in EAEC strains is relatively common， and there is a statistically significant difference in the resistance rates of CFZ， CTX and CIP between urban and suburban EAEC strains. Attention should be given to standardizing the use of clinical antibiotics to effectively control the dissemination of multidrug-resistant EAEC strains.