This study aims to understand the biological characteristics of Streptococcus dysgalacti-ae of yak origin.Bacterial isolation and identification,drug susceptibility test,virulence gene test and pathogenicity test were carried out on milk samples of yaks from Naqu City to evaluate the bi-ological characteristics of the isolated strains.Meanwhile,molecular biological information such as virulence factors and drug resistance genes were analyzed by whole genome sequencing,and viru-lence genes were verified by PCR.The results showed that a strain of Streptococcus dysgalactiae was isolated from the milk of yak,and its colony morphology was pinpoint size,smooth edge and milky white.This strain is sensitive to many antibiotics(penicillin G,cephalosporin,ciprofloxacin,tetracycline,erythromycin,etc.).Virulence gene test results showed that the strain carries six key virulence genes(cyl,eno,scpB,bca,bac and napr),which may be closely related to its pathoge-nicity.In the pathogenicity test,the mice were listless and less active after infection,but no death occurred during the observation period.The pathological changes of spleen,kidney,liver and lung tissue were found,suggesting that the strain had certain pathogenic potential but not high lethali-ty.Whole genome sequencing data showed that the gene length of this strain was 4 079 280 bp,the GC content was 39.41％,3 964 coding genes were predicted,604 of which were annotated as viru-lence factors,and another 28 gene mutations may enhance its pathogenic ability.Through annota-tion of CARD database,two Pat A resistance genes and two lmrp resistance genes were found,re-vealing their potential resistance mechanism.Through whole genome sequencing technology and bioinformatics analysis method,this study revealed the genomic characteristics,drug resistance and pathogenicity mechanism of Streptococcus dysgalactiae of yak origin.The findings provide impor-tant scientific evidence for further exploration of the pathogenicity,drug resistance mechanisms,and molecular evolution of yak-derived Streptococcus agalactiae.

This study aims to understand the biological characteristics of Streptococcus dysgalacti-ae of yak origin.Bacterial isolation and identification,drug susceptibility test,virulence gene test and pathogenicity test were carried out on milk samples of yaks from Naqu City to evaluate the bi-ological characteristics of the isolated strains.Meanwhile,molecular biological information such as virulence factors and drug resistance genes were analyzed by whole genome sequencing,and viru-lence genes were verified by PCR.The results showed that a strain of Streptococcus dysgalactiae was isolated from the milk of yak,and its colony morphology was pinpoint size,smooth edge and milky white.This strain is sensitive to many antibiotics(penicillin G,cephalosporin,ciprofloxacin,tetracycline,erythromycin,etc.).Virulence gene test results showed that the strain carries six key virulence genes(cyl,eno,scpB,bca,bac and napr),which may be closely related to its pathoge-nicity.In the pathogenicity test,the mice were listless and less active after infection,but no death occurred during the observation period.The pathological changes of spleen,kidney,liver and lung tissue were found,suggesting that the strain had certain pathogenic potential but not high lethali-ty.Whole genome sequencing data showed that the gene length of this strain was 4 079 280 bp,the GC content was 39.41％,3 964 coding genes were predicted,604 of which were annotated as viru-lence factors,and another 28 gene mutations may enhance its pathogenic ability.Through annota-tion of CARD database,two Pat A resistance genes and two lmrp resistance genes were found,re-vealing their potential resistance mechanism.Through whole genome sequencing technology and bioinformatics analysis method,this study revealed the genomic characteristics,drug resistance and pathogenicity mechanism of Streptococcus dysgalactiae of yak origin.The findings provide impor-tant scientific evidence for further exploration of the pathogenicity,drug resistance mechanisms,and molecular evolution of yak-derived Streptococcus agalactiae.

BACKGROUND:Previous studies found that the proliferative scar-specific long non-coding RNA lncRNA HSFAS is a novel biomarker that can be used in the diagnosis of hypertrophic scar,but how it functions in hypertrophic scar is not clear. OBJECTIVE:To investigate the role and mechanism of lncRNA HSFAS in hypertrophic scar.METHODS:Fresh scar tissue and surrounding normal skin tissue samples from three patients with hypertrophic scar were collected,and tissue immunofluorescence was used to detect the expression of lncRNA HSFAS in frozen sections of two skin tissues. Primary fibroblasts were isolated from proliferative scarred skin tissue and normal skin tissue and cultured by enzyme digestion method. Quantitative real-time PCR was used to detect the mRNA expression of lncRNA HSFAS in cells. The proteins bound to lncRNA HSFAS were detected by RNA pull-down combined mass spectrometry. GO and KEGG were used to analyze the main functions and pathways of lncRNA HSFAS involved in hypertrophic scar progression. The targeted binding of lncRNA HSFAS to proteins was determined by catRAPID and RPISeq website analysis. RESULTS AND CONCLUSION:Compared with normal skin tissue and fibroblasts from normal skin tissue,the expression of lncRNA HSFAS in human hypertrophic scar tissue and primary fibroblasts from hypertrophic scar tissue was significantly increased (P<0.05). There were 510 proteins clearly bound to lncRNA HSFAS by RNA pull-down combined mass spectrometry. The results of GO and KEGG analyses showed that these proteins were mainly involved in RNA splicing and processing,chromosome synthesis and separation,and cell cycle. Among them,the proteins involved in RNA splicing and processing included scaffold attachment factor B2 and DICER1,and the binding fraction with lncRNA HSFAS was higher. The results of bioinformatics analysis showed that lncRNA HSFAS was bound to scaffold attachment factor B2 and DICER1 proteins. To conclude,lncRNA HSFAS may affect gene expression by interacting with scaffold attachment factor B2 and DICER1 proteins to regulate RNA splicing and processing modification,thus promoting the occurrence and development of hypertrophic scar.

BACKGROUND:Previous studies found that the proliferative scar-specific long non-coding RNA lncRNA HSFAS is a novel biomarker that can be used in the diagnosis of hypertrophic scar,but how it functions in hypertrophic scar is not clear. OBJECTIVE:To investigate the role and mechanism of lncRNA HSFAS in hypertrophic scar.METHODS:Fresh scar tissue and surrounding normal skin tissue samples from three patients with hypertrophic scar were collected,and tissue immunofluorescence was used to detect the expression of lncRNA HSFAS in frozen sections of two skin tissues. Primary fibroblasts were isolated from proliferative scarred skin tissue and normal skin tissue and cultured by enzyme digestion method. Quantitative real-time PCR was used to detect the mRNA expression of lncRNA HSFAS in cells. The proteins bound to lncRNA HSFAS were detected by RNA pull-down combined mass spectrometry. GO and KEGG were used to analyze the main functions and pathways of lncRNA HSFAS involved in hypertrophic scar progression. The targeted binding of lncRNA HSFAS to proteins was determined by catRAPID and RPISeq website analysis. RESULTS AND CONCLUSION:Compared with normal skin tissue and fibroblasts from normal skin tissue,the expression of lncRNA HSFAS in human hypertrophic scar tissue and primary fibroblasts from hypertrophic scar tissue was significantly increased (P<0.05). There were 510 proteins clearly bound to lncRNA HSFAS by RNA pull-down combined mass spectrometry. The results of GO and KEGG analyses showed that these proteins were mainly involved in RNA splicing and processing,chromosome synthesis and separation,and cell cycle. Among them,the proteins involved in RNA splicing and processing included scaffold attachment factor B2 and DICER1,and the binding fraction with lncRNA HSFAS was higher. The results of bioinformatics analysis showed that lncRNA HSFAS was bound to scaffold attachment factor B2 and DICER1 proteins. To conclude,lncRNA HSFAS may affect gene expression by interacting with scaffold attachment factor B2 and DICER1 proteins to regulate RNA splicing and processing modification,thus promoting the occurrence and development of hypertrophic scar.

BACKGROUND:Abnormal extracellular matrix accumulation and excessive proliferation of fibroblasts are the main manifestations of pathological scars.Excessive proliferation of fibroblasts leads to the production of large amounts of collagen-based extracellular matrix.Therefore,to investigate the role of fibroblast fibrosis in the formation of pathological scar will provide a new idea for revealing the mechanism of pathological scar and biological therapy. OBJECTIVE:To investigate the effect of RAS-selective lethal small molecule 3(RSL3)on the fibrosis of human pathological scar fibroblasts. METHODS:Then cases of pathological scar tissue and normal skin tissue samples from the same individuals,provided by the Department of Burn Plastic Surgery,General Hospital of Ningxia Medical University,were collected.Fibroblasts of human pathological scar and human normal skin were extracted and used in the following experiments.The general condition of the pathological scar tissue and the normal skin tissue was detected by hematoxylin-eosin staining.The appearance of fibroblasts from pathological scar and normal skin were observed by inverted microscope.The fibroblasts were verified by immunofluorescence assay.The cells were treated with different concentrations of RSL3(1,3,5,7,9,11,13 μmol/L).The inhibitory concentration of RSL3 on fibroblasts was detected by cell counting kit-8.Control group(without treatment)and RSL3 intervention group(treated with 7 μmol/L RSL3 for 24 hours)were set up.The mRNA and protein expressions of glutathione peroxidase 4,type Ⅰ collagen,type Ⅲ collagen and α-smooth muscle actin were detected by Qrt-PCR and western blot,respectively.Level of malondialdehyde in cells was detected.The residual scratch area was measured by cell scratch test after 24 hours to calculate the percentage of residual scratch area. RESULTS AND CONCLUSION:The expression of glutathione peroxidase 4 in the pathological scar group was higher than that in the normal skin group(Mrna:t=3.252,P<0.01;protein:t=5.075,P<0.01).The expression of glutathione peroxidase 4 in the pathological scar fibroblast group was higher than that in the normal skin fibroblast group(Mrna:t=10.32,P<0.01;protein:t=26.22,P<0.01).Compared with the control group,the expression of glutathione peroxidase 4 was decreased(Mrna:t=2.798,P<0.05;protein:t=4.643,P<0.01),the content of malondialdehyde was increased(t=2.917,P<0.05),the expression of type Ⅰ collagen(Mrna:t=15.84,P<0.01;protein:t=4.610,P<0.01),type Ⅲ collagen(Mrna:t=28.86,P<0.01;protein:t=7.713,P<0.01)and α-smooth muscle actin(Mrna:t=2.671,P<0.05;protein:t=7.417,P<0.01)were decreased in the RSL3 intervention group.Compared with the control group,the migration ability was weakened in the RSL3 intervention group(t=14.06,P<0.01).To conclude,RSL3 can inhibit the expression of glutathione peroxidase 4 and then inhibit the ability of fibrosis and migration of pathological scar fibroblasts.

Objective:To explore the clinicopathological characteristics and the related influencing factors of efficacy and prognosis of elderly patients with malignant mesothelioma(MM)in Chinese population.Methods:We retrospectively analyzed the clinical data of 115 patients aged 65 years and above who were diagnosed with MM in Beijing Hospital, Peking University Cancer Hospital, and Cancer Hospital of Chinese Academy of Medical Sciences between November 2007 and July 2024, and the patients were grouped according to age(≥75 years in the older group and <75 years in the younger group), histological types and therapy regimens.Kaplan-Meier curve and Log-rank test were performed.Cox regression was used in prognostic analysis.Results:The positive expression rate of Calretinin in the Chinese elderly population with MM was consistent with previous reports, while the positive rates of Cytokeratin 5/6(CK5/6), WT-1, and D2-40 were much lower.The overall response ratio(ORR)for first-line treatment was 17.3%(9/52), and the disease control rate(DCR)was 92.3%(48/52).The ORR for second-line treatment was 7.7%(1/13)and the DCR was 76.9%(10/13).The ORR and DCR were higher in the first-line immunotherapy group than in the chemotherapy group, 50.0% vs.14.6%( P=0.134)and 100.0% vs.91.6%( P=1.000), respectively.The ORR in the second-line immunotherapy group was higher than that in the chemotherapy group, 25.0% vs.0, respectively, and the DCR were both 75.0% in two groups.The median progression free survival(mPFS)was 9.2 months and median overall survival(mOS)was 19.0 months for patients receiving first-line treatment, and the mPFS was 3.3 months and mOS was 11.0 months for second-line therapy.The first-line immunotherapy provided more shorter mPFS(1.6 months vs.9.2 months, P=0.081)and longer mOS(not reached vs.18.1 months, P=0.147)than the chemotherapy group.The younger group had prolonged mPFS(9.7 months vs.7.2 months, P=0.305)while shorter mOS(18.1 months vs.23.9 months, P=0.289)compared with the older group, and none of them reached statistical differences.Both mPFS and mOS were prolonged in the epithelioid subtype compared with the non-epithelioid subtypes, 10.4 months vs.1.6 months( P<0.001)and 20.3 months vs.4.6 months( P=0.803), respectively.Both mPFS(7.1 months vs.4.7 months, P=0.583)and mOS(18.3 months vs.6.3 months, P=0.134)were prolonged in the second-line chemotherapy group compared with the immunotherapy group.The Cox regression analysis showed that gender, Eastern Cooperative Oncology Group, Performance Status(ECOG PS)and positive CK5/6 were both the independent predictors for the first-line PFS.Histological type was an independent prognostic factor for the first-line OS. Conclusions:MM in the Chinese elderly population exhibits unique clinicopathologic characteristics.The immunotherapy improves ORR, DCR and prolongs mOS in first-line use, and improves ORR in second-line.First-line treatment improves mPFS in the younger group compared with the older group.Multivariate Cox regression demonstrates that gender, ECOG PS and CK5/6 expression are both predictors of efficacy, and histological type is an independent prognostic factor for survival of the Chinese elderly population with MM.

Objective:To investigate the efficacy and adverse effects of first-line immunotherapy combined with chemotherapy in elderly patients with small cell lung cancer(SCLC)in population of real world.Methods:A total of 148 elderly SCLC patients(age ≥65 years old)underwent pathological diagnosis were retrospectively analyzed from January 2013 to June 2023.103 patients received chemotherapy(chemotherapy group), and 45 patients received immunotherapy combined with chemotherapy(combination group). Patients were divided into senior group(≥75 years old)and younger group(<75 years old)by age.To compare the efficacy of different regimens in first-line treatment, the expression of programmed death-ligand 1(PD-L1)and tumor mutational burden(TMB)were evaluated.Response evaluation criteria in solid tumors(RECIST)version 1.1 was used to evaluate the efficacy, and common terminology criteria for adverse events(CTCAE)version 4.03 was used to evaluate immune-related adverse.Kaplan-meier and Log-rank test were performed.Cox regression was used in prognostic analysis.Results:The overall response rate(ORR)of the first-line combination group in elderly SCLC patients was 79.1%(34/43), which was higher than that of the chemotherapy group 63.2%(60/95), but the difference did not reach statistical significance( χ2=3.451, P=0.063). ORR was significantly higher in the combination group than in the chemotherapy group for patients in the ≥75-year-old group, 87.5%(7/8) vs.48.6%(17/35), respectively( χ2=4.001, P=0.045). The difference in median progression-free survival time(mPFS)in the combination group compared with the chemotherapy group was not statistically significant in the overall patients(5.43 months vs.6.07 months, P=0.660). The combination group prolonged patients' median overall survival time(mOS)compared with the chemotherapy group, but the difference did not reach statistical significance(13.63 months vs.11.97 months, P=0.205). In patients ≥75 years old, mPFS was lower in the combination group than in the chemotherapy group(2.97 months vs.6.47 months), but mOS was prolonged compared with that in the chemotherapy group(13.50 months vs.11.40 months), and none of the differences reached statistical significance(both P>0.05). The differences in mPFS and mOS between the combination group and the chemotherapy group were not statistically significant in patients <75 years old(both P>0.05). In elderly patients with severe comorbidities, mPFS and mOS were lower in the combination group than in the chemotherapy group(5.40 months vs.7.30 months and 10.70 months vs.12.27 months, both P>0.05). In patients without severe comorbidities, the difference in mPFS between the combination group and the chemotherapy group was not statistically significant( P>0.05), but the mOS was significantly longer in the combination group(20.57 months vs.11.57 months, P=0.054). Elderly SCLC patients had a positive PD-L1 tumor cell positive proportion score(TPS)rate(≥1%)of 23.5%(4/17)and a high TMB(≥9 mut/Mb)expression rate of 69.0%(11/16). The overall incidence of immune-related adverse reactions was 71.0%(32/45), grade 3 or higher 33.3%(15/45), and the most common grade 3 adverse reactions were rash, immune-related pneumonia and malaise. Conclusions:First-line immune-combination chemotherapy improves ORR and mOS over chemotherapy in elderly SCLC patients; mOS benefit of immune-combination chemotherapy is more pronounced in patients ≥75 years of age without severe comorbidities, low PD-L1 positivity and high TMB expression are present in elderly SCLC patients, and immune-related adverse effects are generally manageable in elderly patients.

Objective:To investigate the efficacy and adverse reactions of immunotherapy in elderly patients(≥65 years old)with lung squamous cell carcinoma(LUSC)in Chinese population of real world.Methods:A total of 113 elderly LUSC patients(age ≥65 years old)underwent pathological diagnosis were involved from January 2018 to January 2022.To compare the efficacy of mono-immunotherapy or combined with chemotherapy to chemotherapy in first-line and second-line treatment.44 patients received surgical or minimally invasive treatment, and 69 patients received first-line medical treatment, including 27 patients in chemotherapy group, 24 patients in combined chemotherapy group, and 11 patients in single drug immunization group.7 cases in targeted therapy group.Twenty-eight patients received second-line medical treatment, including 8 patients in chemotherapy group, 11 patients in combined immunochemotherapy(combined group), 4 patients in single drug immunotherapy group, and 5 patients in targeted therapy group.The therapeutic effects and adverse reactions were compared between the first-line and second-line treatments.The expression of programmed death-ligand 1(PD-L1)and tumor mutational burden(TMB)were evaluated.Response evaluation criteria in solid tumors(RECIST)version 1.1 was used to evaluate the efficacy, and common terminology criteria for adverse events(CTCAE)version 4.03 was used to evaluate immune-related adverse.Kaplan-meier and log-rank test was performed.Cox regression was used in prognostic analysis.Results:The total effective rate in the first-line combination group was 73.7%(14/19), higher than that in the chemotherapy group(24.0%, 6/25), and the difference was statistically significant( χ2=10.748, P<0.01). Median progression-free survival(mPFS)was longer in the first-line combination group, the immunization group, and the chemotherapy group, and the median overall survival(mOS)was longer in the combination group, but the differences were not statistically significant(all P<0.05); mOS in the second-line combined group were longer than those in the chemotherapy group, both P<0.01). Elderly patients with lung squamous cell carcinoma had high PD-L1 positive rate(≥1%)and high TMB expression rate(≥9 mut/Mb), 81.6%(31/38)and 57.4%(31/54), respectively.mPFS in the PD-L1 positive group(≥1%)was better than that in the PD-L1 negative group(5.10 months vs.0.93 months, P<0.05). Among PD-L1 positive patients, mPFS in the second-line combination group was better than that in the chemotherapy group(7.33 months vs.2.77 months, P<0.05). mPFS and mOS time were not related to TMB expression.The overall incidence of immune-related adverse reactions was 62.0%(31/50), and 26.0%(13/50)with grade 3 or above.The most common grade 3 adverse events were rash, immune-associated pneumonia, and fatigue. Conclusions:Immunology combined with chemotherapy increased objective response rate, mPFS and mOS of elderly patients with LUSC group in first-line therapy compared with chemotherapy.In second-line treatment, the mOS was significantly prolonged in both combination therapy and mono-immunotherapy, and the combination therapy exhibited no benefit in OS compared with monotherapy.The adverse effects of immunology in elderly patients with LUSC were controllable.

Objective:Immunologic characteristics of differed between younger and older patients.This study aimed to screen potentially key genes related to tumor-infiltrated immune cells(TIICs)in senile patients with lung adenocarcinoma(LUAD).Methods:In this retrospective study, the gene expression data for the training set were extracted from the Cancer Genome Atlas(TCGA)database, and the GSE72094 data set from Gene Expression Database was selected as the validation set.The 91 LUAD patients aged ≥75 years and 14 matched normal samples were screened for analysis.The components of tumor infiltrated immune cells(TIICs)were estimated by the deconvolution algorithm.Then a weighted gene co-expression network analysis was conducted in the training set so as to identify key genes correlating to TIICs.The GSE72094 dataset was used for validation.Results:In elderly patients with LUAD, the high expressions of IKZF1 and PRKCB were related to autoimmune diseases and T cell receptor signaling pathway.And their gene encoding proteins could interact with various immunomodulatory factors, such as IL2RB, LCK, and CD5.In the high expression group of IKZF1 and PRKCB, the expression levels of immunological checkpoint genes such as PD-L1, PD-1 and CTLA-4 were significantly higher than those of the low expression group(all P<0.01). The results of the validation set showed that CD8 + T cells were significantly correlated with the expression of IKZF1( r=0.75, P<0.01)and PRKCB( r=0.65, P<0.01). Conclusions:The expressions of IKZF1 and PRKCB in the tumor tissues are related to tumor infiltrating CD8 T cells and expression of immune checkpoint genes in elderly patients with LUAD.

Objective: To evaluate the value of MRI-T₂WI texture analysis in the differentiation of atypical medulloblastoma and ependymoma of the fourth ventricle. Methods: Preoperative MRI data of 36 cases of fourth ventricle tumor (19 cases of medulloblastoma and 17 cases of ependymoma) confirmed by the Central Theater General Hospital of the Chinese People′s Liberation Army were retrospectively analyzed. Manually sketch areas of interest (ROI) were made using texture analysis software to get histogram parameters, including mean, median, standard deviation, skewness, kurtosis, maximum, minimum, heterogeneity, entropy, the 5th percentile (T₂WI_5th), the 10th percentile (T₂WI_10th), the 25th percentile (T₂WI_25th), the 50th percentile (T₂WI_50th), the 75th percentile(T₂WI_75th), the 95th percentile(T₂WI_95th). Independent sample t test or mann-whitney U test was used for statistical analysis of each parameter value between the two groups. Logistic regression analysis was used to perform multiparameter joint analysis on meaningful parameters. The area under the curve (AUC) was obtained by using the subject operating characteristic (ROC) curve to determine the threshold and diagnostic efficacy for distinguishing the two group. Results: The mean, median, T₂WI_5th, T₂WI_10th, T₂WI_25th, T₂WI_50th, T₂WI₇5th values of the medulloblastoma group were smaller than those of the ependymoma group, and difference was statistically significant (P<0.05). The T₂WI_5th had the best diagnostic performance. When the critical value was 1 343, the diagnostic specificity was 75.0% and the sensitivity was 92.9%. Logistic regression was used to predict the joint analysis of probability parameters. T₂WI_5th+T₂WI_10th had the best performance, and AUC was 0.928. When the critical value was 0.75, the diagnostic specificity was 75.0% and the sensitivity was 100.0%. Conclusions MRI-T₂WI texture analysis can provide quantitative information for preoperative diagnosis of atypical medulloblastoma and ependymoma and improve the accuracy of preoperative diagnosis, which has obvious clinical value.