ObjectiveTo establish a reliable chronic obstructive pulmonary disease (COPD) mouse model based on a self-developed multichannel automatic control system for long-term continuous cigarette smoke exposure in small animals using a novel continuous cigarette smoke exposure method, and to conduct phenotypic evaluation and analysis, thereby providing an animal experimental basis for investigating COPD pathogenesis and prevention strategies. MethodsTwenty male C57BL/6J mice aged 6 weeks were randomly and equally divided into a control group and a model group. The model group (n=10) underwent 6 h of continuous cigarette smoke exposure daily (6 cigarettes per day for 12 consecutive weeks), while the control group (n=10) received no intervention. Body weight was monitored biweekly. Post-exposure, in vivo micro-CT imaging was performed. After euthanasia, serum and bronchoalveolar lavage fluid (BALF) levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were quantified by ELISA. Lung tissues underwent H&E and Masson's trichrome staining to observe changes in lung morphology and inflammatory cell infiltration, and the mean linear intercept (MLI) was calculated, thereby comprehensively evaluating the clinical features of COPD in the mouse model. ResultsCompared with the control group, the model group showed significantly reduced body weight (P<0.01) from the fourth week. Compared with the control group, IL-6 level in the serum and BALF of the model group increased by 27.2% and 140.0%, respectively (P<0.01). TNF-α level in the serum and bronchoalveolar lavage fluid of the model group increased by 16.7% (P<0.01) and 19.3% (P<0.05), respectively. Histopathological examination revealed alveolar wall thinning, septal rupture, emphysematous bullae formation, reduced alveolar count, bronchial wall thickening with lumen narrowing, and inflammatory cell infiltration. MLI was significantly elevated (P<0.01). Masson's staining confirmed collagen deposition and bronchial remodeling. Micro-CT demonstrated localized high-density shadows exhibiting typical features of chronic bronchitis. Conclusion The self-developed device enables long-term continuous smoke exposure, and the successfully established COPD mouse model exhibits pathological features highly consistent with clinical manifestations, offering an efficient and reliable tool for COPD research.

Objective:To investigate the molecular mechanism by which 2',4'-dihydroxychalcone(D2)inhibits proliferation,migration,and epithelial-mesenchymal transition(EMT)in colorectal cancer cells through miR-7-5p-mediated autophagy.Methods:Human colorectal cancer cell lines HCT-15 and SW620 were treated with D2 at concentrations of 0,12.5,25,and 50 μmol/L.Cell proliferation and clonogenic capacity were evaluated using MTT and colony formation assays.Cell migration was assessed by wound healing and Transwell assays.WB assay was used to detect the expression of EMT-related proteins,autophagy-related proteins,and key components of the PI3K/AKT/mTOR pathway.Autophagosome formation was visualized by immunofluorescence staining.TCGA database and KEGG pathway analyses were performed to evaluate miR-7-5p expression and its association with colorectal cancer.RT-qPCR was used to quantify miR-7-5p expression,and lentiviral transduction was employed to establish stable miR-7-5p knockdown or overexpression cell lines.Results:D2 significantly inhibited colorectal cancer cell proliferation,migration,and EMT(P<0.05 or P<0.01).TCGA and KEGG analyses revealed that miR-7-5p expression was downregulated in colorectal cancer and closely associated with disease progression.D2 treatment(12.5,25,and 50 μmol/L)significantly upregulated miR-7-5p expression in HCT-15 and SW620 cells(P<0.01).At 25 μmol/L,D2 increased the expression of autophagy-related proteins(LC3 and p-ULK1)and inhibited the PI3K/AKT/mTOR signaling pathway(P<0.05),accompanied by increased autophagosome formation(P<0.01).In miR-7-5p-knockdown cells treated with D2,the levels of LC3 and p-ULK1 were significantly reduced compared to D2-only treated cells(P<0.05 or P<0.01).Conclusion:D2 upregulates miR-7-5p to induce autophagy,thereby inhibiting colorectal cancer cell proliferation,migration,and EMT,possibly through suppression of the PI3K/AKT/mTOR signaling pathway.

Objective The study aims to optimize the conditions for constructing orthotopic nude mouse models of liver cancer by injecting human liver tumor cell lines and to explore appropriate timings for drug administration. Methods Human hepatocellular carcinoma Hep3B and hepatoblastoma HepG2 cell lines, which stably expressing the luciferase reporter gene (LUC), were selected. The linear correlation between the luciferase luminescence intensity and the number of liver tumor cells was analyzed using a Small Animal In Vivo Imaging system to verify the luminescent efficiency of the human liver tumor cells. Different concentrations (8×10⁶, 2.4×10⁷, 7.2×10⁷ cells/mL) and resuspension media (PBS, Matrigel) of human liver tumor cell suspensions HepG2-LUC and Hep3B-LUC were orthotopically inoculated into the liver lobes of 5-week-old female BALB/c nude mice (12 groups, 7 mice each) to construct human liver tumor nude mouse orthotopic cancer models. Every 7 days, the weights of mice were recorded, and the growth of orthotopic tumors was monitored using the Small Animal In Vivo Imaging system. On day 35 post-cell inoculation, mouse livers were dissected, and pathological slices were prepared for HE staining to observe histopathological changes in liver tissues. Results The luminescence intensity of human liver tumor cell lines was positively correlated with the number of cells (R²=0.983 1, R²=0.970 5), indicating their suitability for orthotopic model construction. Successful modeling was achieved in the high-concentration groups of HepG2-LUC, the low-, medium-, and high-concentration groups of HepG2-LUC+Matrigel, the medium- and high-concentration groups of Hep3B-LUC, and the low-, medium-, and high-concentration groups of Hep3B-LUC+Matrigel. For both HepG2-LUC+Matrigel and Hep3B-LUC+Matrigel groups, mice in the high-concentration groups exhibited significantly reduced body weight compared to the low- and medium-concentration groups (both with P<0.05). The luminescence intensity of successfully modeled mice increased exponentially over time (R²>0.950 0), and reached a minimum of 1.0×10⁷ p/(s·cm²·sr) by day 14 post-transplantation. Mice in the low- and medium-concentration groups of HepG2-LUC and the low-concentration group of Hep3B-LUC showed no significant pathological changes, while the other groups exhibited evident liver tumors and hepatocyte lesions. Conclusion For the HepG2-LUC cell line, the recommended injection volume is 50 µL with a cell density of 2.4×10⁷ cells/mL, resuspended with Matrigel, followed by drug administration or prognostic measures on day 7 post-modeling. For the Hep3B-LUC cell line, the recommended injection volume is 50 µL with a cell density of 7.2×10⁷ cells/mL, not resuspended with Matrigel, with administration or prognostic measures on day 14 post-modeling.

Gene-edited mice are the most ideal laboratory animals for studying human gene functions, exploring disease mechanisms, and developing new drugs. Strain resulting from low fertility, aging, illness, etc. can cause irreversible losses to scientific research, so strain rescues of genetically engineering mice require different measures accordingly. Meanwhile, cost control is another key point when a specific technology is applied. First of all, when the only remaining gene-edited mouse in reproductive age suddenly dies, the dead male mouse can be rescued by in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), while the female mouse can be saved by ovarian transplantation, etc. Secondly, due to aging or diseases, mice can be saved through IVF-embryo transfer (ET) and unilateral epididymal tail assisted reproduction. Thirdly, round sperm injection (ROSI) and ovarian transplantation can be used to save endangered mice before sexual maturity with poor life status. This paper reviews rescue techniques of common endangered mice and their applications, which provides a reference for relevant practitioners to better maintain gene-edited mouse strains.

Objectives To access the bacteriology in patients with sepsis due to biliary tract infection to provide a basis for empirical selection of proper antibiotic treatment.Methods This is a single-center retrospective study on 214 patients with biliary tract infection admitted from August 2014 to July 2016 to the surgical intensive care units (ICU) of The First Affiliated Hospital of Sun Yat-sen University.To study the demographic information,sequential organ failure assessment (SOFA),usage of antibiotics before ICU and duration of ICU were analyzed.Bile,peritoneal drainage and blood samples were collected.Results 47 septic shock patients and 25 septic patients due to biliary tract infection were enrolled in the trial.The two groups (the shock group vs.the sepsis group) had a significant difference in the duration of ICU stay [(6.4 ± 4.6) d vs.(2.3 ± 1.8) d,P ＜ 0.05].48 strains of pathogens were isolated from the bile samples.The major pathogens were Escherichia coli (E.coli) (n =23,47.9％),Enterococcus faecalis (n =8,16.7％) and Enterococcus faecium (n =2,4.2％).80 strains of pathogens were isolated from the peritoneal drainage culture samples.E.coli,pseudomonas aeruginosa,and Klebsiella pneumoniae ranked the top 3 species,accounting for 26.3％,11.3％ and 7.5％,respectively.The sensitivity of E.coli isolated from bile to amikacin,imipenem and panipenem were all over 90.0％.Conclusions E.coli was the principal gram-negative bacterium in biliary infection induced sepsis.Early administration of carbapenemes may reduce the occurrence of septic shock in these patients.

With performance evaluation management as the stepping stone,the hospital joined the DRGs with the attending in-charge method by means of enforcing the attending in charge practice,DRGs knowledge training,and identifying problems with DRGs grouped data of the attending physician group, in an effort to explore new methods of medical quality control.Two years of practice provide tools of quality control to strengthen the hospital’s fine management.At the same time,it should also be noticed that DRGs merely diversify management means,as the content and form of which still need to constantly be improved in the course.

By using the diagnosis related groups(DRGs) method, we analyze and compare the rationality and feasibility of outcomes and human resources distribution of clinical specialties and health care professionals.It may increase the hospital management levels and feasibility.The introduction of DRGs for the majority of hospital management may enhance the performance evaluation and human resource levels in the hospitals.

A survey on clinical knowledge of coronary artery disease (CAD) management in general practitioners (GPs) in Beijing was conducted from March to September,2013.The questionnaire contained 4 cases (stable angina pectoris,post-percutaneous coronary intervention,acute anterior myocardial infarction and acute inferior myocardial infarction) and related clinical questions.Five hundred questionnaires were distributed and 471 valid questionnaires were returned with a recovery rate of 94.2％.The correct rate was 87.3％ and 61.8％ for diagnosis and treatment of emergent events in acute anterior myocardial infarction; however,the correct rate for other knowledge was ranged between 23.4％ and 40.6％.The correct rate increased with the educational levels in 5/11 items(P ＜ 0.01)and increased with the professional titles(P ＜ 0.001)in 3/11 items,which was not associated with the attendance of training or frequency of training attendance.The results indicate that clinical knowledge of CAD management for GPs in Beijing should be improved and the training methods should be focused on the clinical capacity.

OBJECTIVE To study the in vitro activity of cefepime combined with sulbactam against carbapenem-resistant strains of Acinetobacter spp clinically isolated. METHODS The activity of each drug alone was determined against 24 isolates. Chequerborad synergy testing was then performed against all the isolates. RESULTS The percentage of the FIC index showed 33.3% synergism, 62.5% additive, 4.2% (1/24) indifference, and no antagonism tively. CONCLUSIONS Testing of cefepime and sulbactam combinations revealed synergism and additivity activity against some carbapenem-resistant strains(23/24) of Acinetobacter spp which could be likely to prove beneficial effect for the treatment of infections due to multidrug-resistant strains of Acinetobacter spp.