Background A diverse cohort of patients and susceptible individuals congregate in healthcare facilities, where exposure to pathogenic microorganisms associated with respiratory infectious diseases constitutes a significant risk factor for cross-infection. Central air-conditioning ventilation systems improve some indoor environment indicators while exacerbating the risk of transmission of respiratory infectious diseases. Objective To investigate the distribution characteristics of microbial communities in the central air-conditioning ventilation systems of hospitals, providing a scientific basis for the selection of microbial indicators in hygiene standards for hospital central air-conditioning ventilation systems and for hospital risk early warning systems. Methods In October 2023, two central air-conditioning ventilation systems were selected from a Grade 3A hospital in Shanghai: one was an all-air air-conditioning system serving the waiting area on the ground floor, and the other was a fan coil plus fresh air system serving the outpatient area on the third floor. Samples from four different components of the ventilation systems—air outlets, filters, surface coolers, and condensate trays—were collected for high-throughput sequencing of the 16S rRNA gene to analyze bacterial communities. Alpha-diversity and beta-diversity analyses were performed to investigate the microbial community composition and diversity characteristics of the hospital central air-conditioning ventilation systems. Functional analysis was conducted to determine the relative abundance of bacterial functions in these systems.Results A total of 528 operational taxonomic units (OTUs) were identified, encompassing 20 bacterial phyla, 37 classes, 79 orders, 123 families, and 240 genera. The analysis revealed that the bacterial community was predominantly composed of Proteobacteria, Gemmatimonadates, Bacteroidetes, and Actinobacteria. The diversity analysis indicated that bacterial community richness and diversity were highest in the condensate trays, while no statistically significant differences (P > 0.05) were observed in the bacterial community composition among the air outlets, filters, and surface coolers. The functional analysis showed that the bacterial communities in the central air-conditioning ventilation systems primarily exhibited chemoheterotrophic, oxidative energy-dependent heterotrophic, and ureolytic functional characteristics. Conclusion The dominance of Proteobacteria suggests that this phylum exhibits strong adaptability in the central air-conditioning ventilation systems, possibly related to its ability to survive and reproduce under varying environmental conditions. The diversity analysis indicates that the condensate tray is a critical area for bacterial proliferation in the central air-conditioning ventilation systems. The similarity in environmental conditions among the air outlets, filters, and surface coolers result in similar bacterial community structures. The functional analysis reveals that the bacterial communities possess robust energy conversion and metabolic capabilities, potentially contributing to processes such as organic matter decomposition and nitrogen cycling within the central air-conditioning ventilation systems.

Objective:To explore the safety and efficacy of intraosseous regional administration (IORA) of vancomycin for preventing infection in primary total knee arthroplasty (TKA).Methods:A total of 124 patients with knee osteoarthritis undergoing TKA between February 2024 and May 2024 at nine hospitals were enrolled. Preoperative infection prophylaxis involved either IORA (0.5 g vancomycin administered via intraosseous regional infusion before incision) or intravenous infusion (1 g vancomycin via peripheral vein). The IORA group included 15 males and 47 females with a median age of 66.5 years (range, 60.0-70.0 years), while the intravenous group included 14 males and 48 females with a median age of 66.0 years (range, 61.8-70.3 years) years. Intraoperative samples were collected including fat and synovium tissues after incision, before prosthesis placement, and after tourniquet release; distal femoral cancellous bone during femoral osteotomy; proximal tibial cancellous bone during tibial osteotomy; proximal intercondylar cancellous bone before prosthesis placement; and peripheral blood from non-infused arms at surgery initiation and after tourniquet release. Vancomycin concentrations were measured using liquid chromatography-tandem mass spectrometry. Vital sign changes were recorded from admission to 5~10 minutes post-IORA (IORA group) or post-incision (intravenous group). Follow-ups were conducted on postoperative day 1 and 3, and at 1 and 3 months, to document complications including IORA-related adverse events, periprosthetic joint infections, surgical site infections, red man syndrome, acute kidney injury, deep vein thrombosis and so on.Results:Vancomycin concentrations in bone, fat, and synovial tissue samples were significantly higher in the IORA group than in the intravenous group ( P<0.05), while vancomycin concentrations in blood samples were significantly lower in the IORA group than in the intravenous group ( P<0.05). Only 7.3%(41/558) of tissue samples in the IORA group had vancomycin concentrations below 2.0 μg/g (the minimum inhibitory concentration of vancomycin against coagulase-negative staphylococcus), compared to 59.3%(331/558) in the intravenous group (χ 2=11.285, P<0.001). In the intravenous group, 16.9%(21/124) of blood samples had vancomycin concentrations exceeding 15.0 mg/L (the threshold associated with a significantly increased risk of nephrotoxicity), while all concentrations in the IORA group were below this threshold, the difference was statistically significant (χ 2=22.943, P<0.001). There were no statistically significant difference ( P>0.05) in vital signs changes before and after vancomycin administration between the two groups. Two patients in the intravenous group experienced incision exudate, while no other related complications occurred in either group. Conclusions:Compared to the traditional intravenous infusion of 1 g vancomycin, intraosseous injection of a low dose (0.5 g) of vancomycin achieves higher local tissue concentrations in the knee joint with a lower incidence of adverse reactions and is safe for infection prophylaxis. Despite guidelines not recommending the routine use of vancomycin for preventing infection after primary TKA, intraosseous injection of 0.5 g vancomycin may be considered intraoperatively for primary TKA in the following scenarios: patients in medical institutions with a high prevalence of methicillin-resistant staphylococcus aureus (MRSA) infections, patients with potential preoperative MRSA colonization, or patients with cephalosporin allergy.

Purpose To investigate the expression of POLR2M in colorectal cancer(CRC)and its effects on cell growth,apoptosis and invasion.Methods GEPIA2.0,TCGA and Kaplan-Meier Plotter databases were used to ana-lyze the differential expression of POLR2M in CRC tissues and normal adjacent tissues,and to evaluate its prognostic significance using the Log-rank test.Quantitative real-time PCR(qRT-PCR)was used to detect the expression of POLR2M in human colorectal cancer cell lines SW480,HCT-8,RKO,LOVO,DLD-1,HCT-116,SW620 and human normal colorectal cell line FHC.DLD-1 and RKO cells were stably transfected with lentivirus,and the POLR2M groups were up-regulated into the control group(LV-NC)and experimental group(LV-POLR2M),and the transient transfec-tion of SW620 and SW480 cells with interfering fragments of SiRNA was used to down-regulate the POLR2M groups into the control group(Si-NC)and experimental group(Si-POLR2M),and the transfection efficiency of each group was verified.CCK-8,plate cloning,Transwell and scratch healing assays were used to detect cell proliferation,invasion and migration.Flow cytometry was used to detect the effects of POLR2M on cell cycle and apoptosis.Results GE-PIA2.0,TCGA and Kaplan-Meier Plotter database analysis showed that the expression of POLR2M in colorectal cancer was significantly higher than in normal adjacent tissues(P＜0.05),and the expression of POLR2M was closely associ-ated with the histological type of colorectal cancer and lymph node metastasis(P＜0.05),but not with the age,gen-der,tumor grade and vascular invasion of patients(P＞0.05).The prognosis of patients with POLR2M overexpression was poor(P＜0.05).The results of qRT-PCR showed that compared with FHC cells,the mRNA expression of POLR2M in SW480,HCT-8,RKO,LOVO,DLD-1,HCT-116 and SW620 cell lines was increased(F=97.7,P＜0.05),and POLR2M stable overexpression and interference cell lines were successfully constructed.Compared with the LV-NC group,the viability,colony number,number of cells passing through the chamber and cell mobility of DLD-1 and RKO cells in the LV-POLR2M group were significantly increased(P＜0.05).Compared with the Si-NC group,the viability,colony number,number of cells passing through the chamber,and cell mobility of SW620 and SW480 cells in the Si-POLR2M group were significantly decreased(P＜0.05).Downregulation of POLR2M induced cell cycle arrest in G1 phase and promotes apoptosis(P＜0.05).Conclusion POLR2M may play a role as a pro-tumor gene in CRC,and its high expression can significantly promote the proliferation and invasion of CRC cells.

Aortic aneurysm(AA)and aortic dissection(AD)are critical cardiovascular disease emergencies that seriously threaten human life and health.Due to various factors,the progressive reduction of various types of cells,such as smooth muscle cells and endothelial cells in the aortic wall,is an essential mechanism for developing AA and AD.On this basis,AD is induced by mechanical stresses such as hypertension,leading to damaged endothelial rupture or hemor-rhage within the aortic wall.However,AA causes the aortic wall to thin and expand outward in response to stimuli such as prolonged blood flow impingement.At present,increasing evidence shows that various programmed cell death,such as apoptosis,necroptosis,pyroptosis,ferroptosis,copper death,poly ADP-ribose polymerase 1(PARP-1)-dependent cell death,and immunogenic cell death,play essential roles in the pathogenesis of AA and AD.Therefore,understanding the key molecules and pathways in the pathogenesis of AA and AD from the perspective of programmed cell death and searching for inhibitors of various types of programmed death is essential to prevent aortic destruction and disease progression.The review summarizes the roles and research progress of different types of programmed cell death modalities in the development of AA and AD,clarifies the central position of programmed cell death in forming AA and AD,and searches for new thera-peutic methods for the clinic.

Purpose To investigate the expression of POLR2M in colorectal cancer(CRC)and its effects on cell growth,apoptosis and invasion.Methods GEPIA2.0,TCGA and Kaplan-Meier Plotter databases were used to ana-lyze the differential expression of POLR2M in CRC tissues and normal adjacent tissues,and to evaluate its prognostic significance using the Log-rank test.Quantitative real-time PCR(qRT-PCR)was used to detect the expression of POLR2M in human colorectal cancer cell lines SW480,HCT-8,RKO,LOVO,DLD-1,HCT-116,SW620 and human normal colorectal cell line FHC.DLD-1 and RKO cells were stably transfected with lentivirus,and the POLR2M groups were up-regulated into the control group(LV-NC)and experimental group(LV-POLR2M),and the transient transfec-tion of SW620 and SW480 cells with interfering fragments of SiRNA was used to down-regulate the POLR2M groups into the control group(Si-NC)and experimental group(Si-POLR2M),and the transfection efficiency of each group was verified.CCK-8,plate cloning,Transwell and scratch healing assays were used to detect cell proliferation,invasion and migration.Flow cytometry was used to detect the effects of POLR2M on cell cycle and apoptosis.Results GE-PIA2.0,TCGA and Kaplan-Meier Plotter database analysis showed that the expression of POLR2M in colorectal cancer was significantly higher than in normal adjacent tissues(P＜0.05),and the expression of POLR2M was closely associ-ated with the histological type of colorectal cancer and lymph node metastasis(P＜0.05),but not with the age,gen-der,tumor grade and vascular invasion of patients(P＞0.05).The prognosis of patients with POLR2M overexpression was poor(P＜0.05).The results of qRT-PCR showed that compared with FHC cells,the mRNA expression of POLR2M in SW480,HCT-8,RKO,LOVO,DLD-1,HCT-116 and SW620 cell lines was increased(F=97.7,P＜0.05),and POLR2M stable overexpression and interference cell lines were successfully constructed.Compared with the LV-NC group,the viability,colony number,number of cells passing through the chamber and cell mobility of DLD-1 and RKO cells in the LV-POLR2M group were significantly increased(P＜0.05).Compared with the Si-NC group,the viability,colony number,number of cells passing through the chamber,and cell mobility of SW620 and SW480 cells in the Si-POLR2M group were significantly decreased(P＜0.05).Downregulation of POLR2M induced cell cycle arrest in G1 phase and promotes apoptosis(P＜0.05).Conclusion POLR2M may play a role as a pro-tumor gene in CRC,and its high expression can significantly promote the proliferation and invasion of CRC cells.

Aortic aneurysm(AA)and aortic dissection(AD)are critical cardiovascular disease emergencies that seriously threaten human life and health.Due to various factors,the progressive reduction of various types of cells,such as smooth muscle cells and endothelial cells in the aortic wall,is an essential mechanism for developing AA and AD.On this basis,AD is induced by mechanical stresses such as hypertension,leading to damaged endothelial rupture or hemor-rhage within the aortic wall.However,AA causes the aortic wall to thin and expand outward in response to stimuli such as prolonged blood flow impingement.At present,increasing evidence shows that various programmed cell death,such as apoptosis,necroptosis,pyroptosis,ferroptosis,copper death,poly ADP-ribose polymerase 1(PARP-1)-dependent cell death,and immunogenic cell death,play essential roles in the pathogenesis of AA and AD.Therefore,understanding the key molecules and pathways in the pathogenesis of AA and AD from the perspective of programmed cell death and searching for inhibitors of various types of programmed death is essential to prevent aortic destruction and disease progression.The review summarizes the roles and research progress of different types of programmed cell death modalities in the development of AA and AD,clarifies the central position of programmed cell death in forming AA and AD,and searches for new thera-peutic methods for the clinic.

Objective:To explore the safety and efficacy of intraosseous regional administration (IORA) of vancomycin for preventing infection in primary total knee arthroplasty (TKA).Methods:A total of 124 patients with knee osteoarthritis undergoing TKA between February 2024 and May 2024 at nine hospitals were enrolled. Preoperative infection prophylaxis involved either IORA (0.5 g vancomycin administered via intraosseous regional infusion before incision) or intravenous infusion (1 g vancomycin via peripheral vein). The IORA group included 15 males and 47 females with a median age of 66.5 years (range, 60.0-70.0 years), while the intravenous group included 14 males and 48 females with a median age of 66.0 years (range, 61.8-70.3 years) years. Intraoperative samples were collected including fat and synovium tissues after incision, before prosthesis placement, and after tourniquet release; distal femoral cancellous bone during femoral osteotomy; proximal tibial cancellous bone during tibial osteotomy; proximal intercondylar cancellous bone before prosthesis placement; and peripheral blood from non-infused arms at surgery initiation and after tourniquet release. Vancomycin concentrations were measured using liquid chromatography-tandem mass spectrometry. Vital sign changes were recorded from admission to 5~10 minutes post-IORA (IORA group) or post-incision (intravenous group). Follow-ups were conducted on postoperative day 1 and 3, and at 1 and 3 months, to document complications including IORA-related adverse events, periprosthetic joint infections, surgical site infections, red man syndrome, acute kidney injury, deep vein thrombosis and so on.Results:Vancomycin concentrations in bone, fat, and synovial tissue samples were significantly higher in the IORA group than in the intravenous group ( P<0.05), while vancomycin concentrations in blood samples were significantly lower in the IORA group than in the intravenous group ( P<0.05). Only 7.3%(41/558) of tissue samples in the IORA group had vancomycin concentrations below 2.0 μg/g (the minimum inhibitory concentration of vancomycin against coagulase-negative staphylococcus), compared to 59.3%(331/558) in the intravenous group (χ 2=11.285, P<0.001). In the intravenous group, 16.9%(21/124) of blood samples had vancomycin concentrations exceeding 15.0 mg/L (the threshold associated with a significantly increased risk of nephrotoxicity), while all concentrations in the IORA group were below this threshold, the difference was statistically significant (χ 2=22.943, P<0.001). There were no statistically significant difference ( P>0.05) in vital signs changes before and after vancomycin administration between the two groups. Two patients in the intravenous group experienced incision exudate, while no other related complications occurred in either group. Conclusions:Compared to the traditional intravenous infusion of 1 g vancomycin, intraosseous injection of a low dose (0.5 g) of vancomycin achieves higher local tissue concentrations in the knee joint with a lower incidence of adverse reactions and is safe for infection prophylaxis. Despite guidelines not recommending the routine use of vancomycin for preventing infection after primary TKA, intraosseous injection of 0.5 g vancomycin may be considered intraoperatively for primary TKA in the following scenarios: patients in medical institutions with a high prevalence of methicillin-resistant staphylococcus aureus (MRSA) infections, patients with potential preoperative MRSA colonization, or patients with cephalosporin allergy.

Bipolar disorder with mixed features is currently a prevalent clinical phenomenon,with patients exhibiting a heightened risk of suicidal behaviour,suboptimal therapeutic outcomes,poor prognostic indicators and frequently accompanied by significant impairment in psychosocial functioning.The current body of research on the pathological mechanisms of bipolar disorder with mixed features has proposed several mechanisms including neurotransmitter imbalance leading to abnormal emotion regulation,hypothalamic-pituitary-adrenal(HPA)dysfunction triggering an excessive stress response,circadian rhythm disorder affecting the sleep pattern,abnormal functional connectivity of the cerebral cortex and limbic system,independent and multidirectional changes in four dimensions,such as behaviour,cognition,mood,and sleep.Further studies are required to integrate the results of neurobiology,imaging,genetics and other multidisciplinary fields in order to provide more precise targets for the diagnosis and treatment of bipolar disorder with mixed features.

convalescents, and to screen for broad-spectrum neutralizing antibodies against the SARS-CoV-2 RBD. Methods Using biotinylated RBD as a molecular probe, flow cytometry was employed to perform single-cell sorting of B cells from peripheral blood mononuclear cells (PBMCs) of convalescents. The obtained B cells were lysed and subjected to reverse transcription, followed by nested PCR amplification of the heavy and light chains of antibodies was conducted using random primers. The amplified products were cloned into corresponding expression vectors, and the respective matched heavy-light chain plasmids were co-transfected into 293F cells for expression. Monoclonal antibodies were then purified using Protein A column chromatography. Neutralization experiments were conducted with the wild-type (WT) pseudovirus, and antibodies with IC50<0.1 μg/mL were selected for further testing of neutralizing breadth and potency against the wild-type (WT), Beta variant (B.1.351), Delta variant (B.1.617.2), and currently prevalent pseudovirus strains (XBB, BA.5, BF.7). Results A total of 21 RBD-specific monoclonal B cells were obtained from two recovered patients, resulting in the isolation of 13 pairs of antibody light/heavy chains. Nine antibodies were successfully expressed, with P1-A1, P1-B6, and P1-B9 exhibiting IC50 values below 0.1 μg/mL against the pseudovirus of the wild-type strain (WT). Specifically, P1-B6 effectively neutralized the wild-type strain (WT), Beta variant (B.1.351), and Delta variant (B.1.617.2), with IC50 values reaching 0.01 μg/mL. P1-B9 demonstrated effective neutralization against the wild-type strain (WT), Beta variant (B.1.351), Delta variant (B.1.617.2), and Gamma variant (P.1) pseudoviruses, with IC50 values of 0.42 μg/mL, 0.63 μg/mL, 0.28 μg/mL, and 2.50 μg/mL, respectively. Additionally, P1-B6 exhibited good neutralization against BA.5 and BF.7 pseudoviruses, with IC50 values of 0.06 μg/mL and 0.09 μg/mL, respectively. Conclusions Infection with the SARS-CoV-2 WT strain can induce the generation of neutralizing antibodies with broad-spectrum activity. Generating these broadly neutralizing antibodies does not require an excessively high somatic hypermutation. The obtained antibodies can be used as candidates for SARS-CoV-2 diagnosis and prevention.