Objective To isolate pathogenic bacteria from the skin of a nude mouse exhibiting squamous skin scurfs, and perform bacterial identification, traceability analysis, and pathogenicity studies to provide a new approach for the diagnosis of pathogens in nude mice with squamous skin scurfs. MethodsSkin swab samples were collected from a nude mouse exhibiting squamous skin scurfs for nucleic acid testing, bacterial isolation and culture, biochemical identification, 16S rDNA gene amplification and sequencing, and whole genome sequencing to construct a phylogenetic tree. Fifteen BALB/c nude mice were randomized into a saline-treated control group, a high-concentration group treated with 1.8×10⁸ CFU/mL of the isolated bacterial suspension, and a low-concentration group treated with 1.8×10⁷ CFU/mL of the isolated bacterial suspension. Pathogenicity was assessed by animal infection experiments and observation of histopathological changes in skin tissue using HE staining. Results The nucleic acid test for Corynebacterium bovis was negative, excluding infection by this organism. The pathogen isolated on mannitol salt agar and blood agar, combined with Gram staining, suggested a Gram-positive Staphylococcus species. The isolated strain was identified by 16S rDNA sequencing and a fully automated microbial identification system as Staphylococcus xylosus. Phylogenetic tree analysis based on whole genome sequencing showed that the strain was most closely related to an isolate from leafy vegetables in South Korea (GenBank GCA_00207825.1). In the high-concentration group, squamous skin scurfs appeared on the head, neck, and back of nude mice on the 17th day post-infection, while in the low concentration group, similar symptoms appeared on the 20th day post-infection and gradually spread to other areas. The scaling symptoms were transient, lasting for 7 days in the high-concentration group and 3 days in the low-concentration group, after which the skin returned to normal. The infection rate was 33.33% in both the high- and low-concentration groups. No significant pathological changes were observed in the skin tissues of infected mice compared to the control group, indicating marked individual differences in the pathogenicity of the strain in nude mice. Conclusion A strain of Staphylococcus xylosus was isolated from the skin of a nude mouse exhibiting squamous skin scurfs. The strain is an opportunistic pathogen that causes transient squamous skin scurfs without significant histopathological changes, and there are individual differences in the sensitivity of nude mice to this strain. These findings can provide valuable data for pathogen identification in immunodeficient or gene knockout mice.

Objective To isolate pathogenic bacteria from the skin of a nude mouse exhibiting squamous skin scurfs, and perform bacterial identification, traceability analysis, and pathogenicity studies to provide a new approach for the diagnosis of pathogens in nude mice with squamous skin scurfs. MethodsSkin swab samples were collected from a nude mouse exhibiting squamous skin scurfs for nucleic acid testing, bacterial isolation and culture, biochemical identification, 16S rDNA gene amplification and sequencing, and whole genome sequencing to construct a phylogenetic tree. Fifteen BALB/c nude mice were randomized into a saline-treated control group, a high-concentration group treated with 1.8×10⁸ CFU/mL of the isolated bacterial suspension, and a low-concentration group treated with 1.8×10⁷ CFU/mL of the isolated bacterial suspension. Pathogenicity was assessed by animal infection experiments and observation of histopathological changes in skin tissue using HE staining. Results The nucleic acid test for Corynebacterium bovis was negative, excluding infection by this organism. The pathogen isolated on mannitol salt agar and blood agar, combined with Gram staining, suggested a Gram-positive Staphylococcus species. The isolated strain was identified by 16S rDNA sequencing and a fully automated microbial identification system as Staphylococcus xylosus. Phylogenetic tree analysis based on whole genome sequencing showed that the strain was most closely related to an isolate from leafy vegetables in South Korea (GenBank GCA_00207825.1). In the high-concentration group, squamous skin scurfs appeared on the head, neck, and back of nude mice on the 17th day post-infection, while in the low concentration group, similar symptoms appeared on the 20th day post-infection and gradually spread to other areas. The scaling symptoms were transient, lasting for 7 days in the high-concentration group and 3 days in the low-concentration group, after which the skin returned to normal. The infection rate was 33.33% in both the high- and low-concentration groups. No significant pathological changes were observed in the skin tissues of infected mice compared to the control group, indicating marked individual differences in the pathogenicity of the strain in nude mice. Conclusion A strain of Staphylococcus xylosus was isolated from the skin of a nude mouse exhibiting squamous skin scurfs. The strain is an opportunistic pathogen that causes transient squamous skin scurfs without significant histopathological changes, and there are individual differences in the sensitivity of nude mice to this strain. These findings can provide valuable data for pathogen identification in immunodeficient or gene knockout mice.

Objective To study the effect of intra-aortic balloon pump(IABP)in the therapy of ST-segment-elevation myocardial infarction(STEMI)patients complicated with ventricular septal rupture(VSR).Methods A retrospective analysis was performed on 35 STEMI patients complicated with VSR.Those patients were admitted in Yan'an Hospital Affiliated to Kunming Medical University from January 2019 to June 2023.Patients were divided into the combine-treated group(20 cases)and the drug-treated group(15 cases)according to the therapeutic strategies.The combine-treated group received IABP implantation and drug therapy,and the drug-treated group only received drug therapy.The clinical characteristics,hemodynamic and cardiac function improvement and mortality were evaluated.Hemodynamic and cardiac function improvement were compared between the two groups.Results There were no statistically significant differences in age,male proportion and size of VSR between the two groups(P>0.05).In the combine-treated group,the average heart rate,the average arterial blood pressure,central venous pressure,the LVEF value of cardiac ultrasound,pleural effusion,B-Line of lung,the level of B-type natriuretic peptide(BNP),the level of serum creatinine and the level of serum lactic acid were improved at 72 h after IABP use(all P<0.05).All these indicators got worse in the drug-treated group.The mortality rate of the combine-treated group was markedly lower than that of the drug-treated group(P<0.05).The mortality rate of patients who received IABP implantation within 72 h after VSR was lower than that of patients who received IABP implantation beyond 72 h after VSR.Conclusion For patients with AMI complicated with VSR,implantation of IABP can significantly improve hemodynamics,cardiac function and reduce mortality.

ObjectiveTo explore the intervention effect and molecular mechanism of Dabufei decoction in Dunhuang formula combined with cisplatin on Lewis lung adenocarcinoma-bearing mice. MethodFifty C57BL/6J mice were used， with 10 randomly assigned to the blank group （without modeling）， and 40 subcutaneously inoculated with Lewis cells to establish a Lewis lung adenocarcinoma-bearing mouse model. These 40 mice were randomly divided into the following four groups （with 10 mice in each group）： Model group （equal volume of physiological saline）， cisplatin group （5 mg·kg^-1）， Dabufei decoction group （14.35 g·kg^-1·d^-1）， and Dabufei decoction combined with cisplatin group （Dabufei decoction 14.35 g·kg^-1·d^-1 + cisplatin 5 mg·kg^-1）. Each group was treated continuously for 14 days. The general condition of the mice was observed， body weight changes were recorded， and the tumor inhibition rate， spleen index， and thymus index were calculated. Peripheral blood white blood cell （WBC）， platelet （PLT）， and hemoglobin （HGB） were detected by routine blood tests. Flow cytometry was used to detect the expression of CD4⁺CD25⁺FoxP3⁺ regulatory T cells （Treg） and natural killer （NK） cells in the spleen. Western blot and real-time quantitative polymerase chain reaction （Real-time PCR） were used to determine the expression of proteins and mRNA related to the phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）/mammalian target of rapamycin （mTOR） signaling pathway in tumor tissues. ResultCompared with the blank group， the model group showed decreased body weight （P<0.05）， spleen index， and thymus index （P<0.05）， decreased percentage of NK cells in the spleen （P<0.05）， increased percentage of Treg cells （P<0.05）， and decreased counts of WBC， PLT， and HGB （P<0.05）. Compared with the model group， the Dabufei decoction group exhibited significant tumor growth inhibition， increased body weight， and reduced tumor weight （P<0.05）， increased percentage of NK cells （P<0.05）， decreased proportion of Treg cells （P<0.05）， and increased counts of WBC， PLT， and HGB （P<0.05）. In the cisplatin group， tumor growth was significantly inhibited， body weight significantly decreased （P<0.05）， and tumor weight significantly reduced （P<0.05）. The spleen index and thymus index decreased （P<0.05）， and the percentage of Treg cells significantly decreased （P<0.05）. The counts of WBC， PLT， and HGB significantly decreased （P<0.05）. In the Dabufei decoction combined with cisplatin group， tumor growth was significantly inhibited， and tumor weight significantly reduced （P<0.05）. The levels of phosphorylated PI3K， Akt， and mTOR proteins and mRNA in tumor tissues were significantly reduced in all medication groups （P<0.05）. Compared with the cisplatin group， the Dabufei decoction combined with cisplatin group showed significantly inhibited tumor growth， reduced tumor weight （P<0.05）， increased body weight （P<0.05）， increased spleen index and thymus index （P<0.05）， increased percentage of NK cells （P<0.05）， decreased percentage of Treg cells （P<0.05）， significantly increased counts of WBC， PLT， and HGB （P<0.05）， and reduced levels of phosphorylated PI3K， Akt， and mTOR and their mRNA （P<0.05）. ConclusionDabufei decoction combined with cisplatin has a synergistic effect with reduced toxicity， effectively regulating immune function， increasing the proportion of NK cells， reducing the proportion of Treg cells， improving bone marrow suppression， and downregulating the PI3K/Akt/mTOR signaling pathway to inhibit tumor growth in Lewis lung adenocarcinoma-bearing mice.

BACKGROUND:Intervertebral disc degeneration is clinically considered to be the main cause of low back pain,but due to the unclear pathogenesis of intervertebral disc degeneration,there is still a lack of effective means to delay the progression of the disease.Single-cell RNA sequencing technology can amplify and sequence mRNA at the single-cell level,reveal the gene expression intensity of a single cell,discover different cell subsets in tissues according to the heterogeneity of cells,study the pathogenesis of intervertebral disc degeneration at the molecular level,and provide a new theoretical basis for its early diagnosis and treatment. OBJECTIVE:To introduce the basic principles of single-cell RNA sequencing technology and review the research progress of single-cell RNA sequencing technology in intervertebral disc degeneration in recent years. METHODS:A computer was used to search PubMed,Web of Science,CNKI and WanFang databases for the literature published from 2012 to 2022.Key words were"single-cell RNA sequencing,intervertebral disc degeneration,sequencing Technology"in Chinese and English.Duplicate,poor-quality and irrelevant articles were excluded;a total of 70 articles were eventually included. RESULTS AND CONCLUSION:(1)We identified new cell subsets such as homeostatic chondrocytes,hypertrophy chondrocyte-like nucleus pulposus cells and fibrous nucleus pulposus cells,identified the marker genes and transcription factors of these cell subsets,and described the functions,differentiation paths and cell fate of these cell subsets during the development and progression of intervertebral disc degeneration,and proposed the concept of progenitor nucleus pulposus cells.A cell subpopulation with progenitor nucleus pulposus cells properties was identified and its effectiveness in treating intervertebral disc degeneration was verified in mice.(2)Fibro chondrocyte-like annulus fibrosus cells and annulus fibrosus stem cells with both cartilage and fiber properties were identified,and a new type of composite hydrogel was prepared by combining fibrous cartilage inducers silk fibroin and hyaluronic acid in vitro.Experiments in mice demonstrated that this hydrogel could repair both annulus fibrosus tissue and cartilage matrix,and was remarkably effective in the treatment of intervertebral disc degeneration.(3)Regulatory chondrocytes were found in endplate cartilage.Two distinct fates in the progression of intervertebral disc degeneration were analyzed and the differential genes in the two fates were identified.Intercellular communication analysis indicated that regulatory chondrocytes interact with endothelial cells to promote angiogenesis.(4)Immune cells such as macrophages,T cells,myeloid progenitor cells and neutrophils were identified in the degenerated intervertebral disc tissues,demonstrating the existence of immune response during intervertebral disc degeneration.It was found that apolipoprotein induced the polarization of macrophages M1 and M2 subtypes,and this polarization process affected the activity of progenitor nucleus pulposus cells by amplifying the inflammatory response through the MIF signaling pathway.

Objective:To investigate the epidemiological and clinical characteristics of RSV among patients aged ≥60 years in Beijing from 2015 to 2023.Methods:Based on the respiratory pathogen surveillance system, samples of upper respiratory tract infections (URTI), non-severe community-acquired pneumonia (nsCAP) and severe community-acquired pneumonia (sCAP) among people aged ≥60 years were collected from 28 sentinel hospitals in 16 districts of Beijing from January 2015 to December 2023. Swab samples were collected from URTI within one week, and lower respiratory tract samples from nsCAP and sCAP were collected. Demographic and epidemiological data were also collected. Various respiratory pathogens including RSV were detected.Results:From January 2015 to December 2023, a total of 20 349 cases of acute respiratory infections aged ≥60 years were included, with the RSV-positive rate of 1.54% (313/20 349, 95% CI: 1.39%-1.68%). Among them, the total RSV-positive rates of older people during the pre-pandemic, pandemic, and post-pandemic periods of COVID-19 were 1.59% (207/13 006, 95% CI: 1.38%-1.81%), 0.82% (38/4 650, 95% CI: 0.56%-1.08%) and 2.53% (68/2 693, 95% CI: 1.93%-3.12%), respectively. The difference in RSV-positive rate was statistically significant ( P<0.001). Based on the sampling time of cases, the RSV epidemic season for older people in Beijing was from October to March of the following year, with a peak period in December or January of the following year. In the post COVID-19 pandemic, there were very few RSV-positive cases detected in the elderly from April to June 2023, with only one positive case detected in May and one in June. The RSV-positive rate of older people increased significantly from October to December, reaching 11.75% (51/383) in December. Among 263 RSV-positive cases in the elderly, RSV-A, RSV-B and unclassified type accounted for 43.35% (114/263), 29.28% (77/263) and 27.38% (72/263), respectively. Since 2020, there has been a subtype conversion, with RSV-B being the main focus. Among 197 elderly cases that have complete clinical data, the main symptoms were cough (86.8%, 171/197), sputum (80.2%, 158/197) and fever (73.60%, 145/197). About 24.87% (49/197) of elderly cases experienced complications. The hospitalization mortality rate was 4.57% (9/197), and the hospitalization rate was 78.68% (155/197). The ICU occupancy rate was 1.99% (36/197). The mechanical ventilation usage rate was 13.32% (33/197), and the length of hospital stay [ M ( Q1, Q3)] was 12 (9, 16) days. Conclusion:In Beijing, the RSV infection rate is relatively low during the COVID-19 pandemic, and the prevalence of COVID-19 is relatively high. In 2023, there was no out-of-season outbreak of RSV infection among the elderly. Elderly RSV infection cases have multiple complications, severe diseases, and poor prognosis.

Objective To establish and evaluate a method for rapid and sensitive S.xylosus detection using qPCR(real-time quantitative PCR).Methods A gehM gene fragment was selected as the target for S.xylosus.A set of specific primers was synthesized and a qPCR method was established to detect S.xylosus.A S.xylosus standard strain and other non-target strains were chosen for analysis.DNA of S.xylosus was diluted 10-fold to determine its sensitivity.Clinical samples were tested,and positive products were sequenced.The result were compared with those of bacterial culture.Results S.xylosus had a specific amplification curve,whereas other non-S.xylosus species did not,indicating that the primers were specific for S.xylosus.Sensitivity was 100 fg/μL DNA.Repeatability within and between groups was less than 3％.A total of 60 clinical samples were analyzed,of which five samples had a typical S curve.qPCR products were sequenced and BLAST searched.The similarity of the gene sequences was 99.63％,indicating that the sample was positive for the S.xylosus gehM gene with a positivity rate of 8.3％.However,the positivity rate of bacterial culture was 6.7％.The positivity rate of qPCR was slightly higher than that of the culture.Conclusions The established qPCR method is rapid with high sensitivity and specificity,and can be used to detect S.xylosus.

Objective:To investigate the epidemiological and clinical characteristics of RSV among patients aged ≥60 years in Beijing from 2015 to 2023.Methods:Based on the respiratory pathogen surveillance system, samples of upper respiratory tract infections (URTI), non-severe community-acquired pneumonia (nsCAP) and severe community-acquired pneumonia (sCAP) among people aged ≥60 years were collected from 28 sentinel hospitals in 16 districts of Beijing from January 2015 to December 2023. Swab samples were collected from URTI within one week, and lower respiratory tract samples from nsCAP and sCAP were collected. Demographic and epidemiological data were also collected. Various respiratory pathogens including RSV were detected.Results:From January 2015 to December 2023, a total of 20 349 cases of acute respiratory infections aged ≥60 years were included, with the RSV-positive rate of 1.54% (313/20 349, 95% CI: 1.39%-1.68%). Among them, the total RSV-positive rates of older people during the pre-pandemic, pandemic, and post-pandemic periods of COVID-19 were 1.59% (207/13 006, 95% CI: 1.38%-1.81%), 0.82% (38/4 650, 95% CI: 0.56%-1.08%) and 2.53% (68/2 693, 95% CI: 1.93%-3.12%), respectively. The difference in RSV-positive rate was statistically significant ( P<0.001). Based on the sampling time of cases, the RSV epidemic season for older people in Beijing was from October to March of the following year, with a peak period in December or January of the following year. In the post COVID-19 pandemic, there were very few RSV-positive cases detected in the elderly from April to June 2023, with only one positive case detected in May and one in June. The RSV-positive rate of older people increased significantly from October to December, reaching 11.75% (51/383) in December. Among 263 RSV-positive cases in the elderly, RSV-A, RSV-B and unclassified type accounted for 43.35% (114/263), 29.28% (77/263) and 27.38% (72/263), respectively. Since 2020, there has been a subtype conversion, with RSV-B being the main focus. Among 197 elderly cases that have complete clinical data, the main symptoms were cough (86.8%, 171/197), sputum (80.2%, 158/197) and fever (73.60%, 145/197). About 24.87% (49/197) of elderly cases experienced complications. The hospitalization mortality rate was 4.57% (9/197), and the hospitalization rate was 78.68% (155/197). The ICU occupancy rate was 1.99% (36/197). The mechanical ventilation usage rate was 13.32% (33/197), and the length of hospital stay [ M ( Q1, Q3)] was 12 (9, 16) days. Conclusion:In Beijing, the RSV infection rate is relatively low during the COVID-19 pandemic, and the prevalence of COVID-19 is relatively high. In 2023, there was no out-of-season outbreak of RSV infection among the elderly. Elderly RSV infection cases have multiple complications, severe diseases, and poor prognosis.

Background::Carotid intima-media thickness (IMT) and diameter, stiffness, and wave reflections, are independent and important clinical biomarkers and risk predictors for cardiovascular diseases. The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods::A total of 3053 healthy Han Chinese adults (1922 women) aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022. The real-time tracking of common carotid artery walls was achieved by the radio frequency (RF) ultrasound system. The IMT, diameter, compliance coefficient, β stiffness, local pulse wave velocity (PWV), local systolic blood pressure, augmented pressure (AP), and augmentation index (AIx) were then automatically measured and reported. Data were stratified by age groups and sex. The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions. The major clinical determinants of carotid properties were identified by Pearson’s correlation, multiple linear regression, and analyses of covariance.Results::All the parameters of carotid properties demonstrated significantly age-related trajectories. Women showed thinner IMT, smaller carotid diameter, larger AP, and AIx than men. The β stiffness and PWV were significantly higher in men than women before forties, but the differences reversed after that. The increase rate of carotid IMT (5.5 μm/year in women and 5.8 μm/year in men) and diameter (0.03 mm/year in both men and women) were similar between men and women. For the stiffness and wave reflections, women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes (all P for age by sex interaction <0.05). The blood pressures, body mass index (BMI), and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex. Conclusions::The age- and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established. The blood pressures, BMI, and triglyceride levels should be considered for clinical application of corresponding reference values.