This study aims to investigate the biological function of the Clumping factor B(clfB)gene in Staphylococcus aureus.The recombinant plasmid pBT2-△clfB was constructed and elec-troporated into Staphylococcus aureus J57 to delete clfB by homologous recombination.The ex-pression plasmid pLI50-clfB was constructed,modified,and electroporated into clfB gene deletion strain △clfB and constructed a complementation strain(C△clfB).J57,△clfB,and C△clfB were cultured at 37℃ for 12 h,and the growth curves of each strain were plotted.The hemolytic properties of each strain were analyzed by contact method,the motility of each strain on TSA plates was determined,and the autolysis rate of each strain under the action of TritonX-100 was determined.Crystal violet staining was used to detect each strain's biofilm formation ability,and biofilm components formed by each strain were quantitatively analyzed.The K-B method was used to determine the sensitivity of each strain to commonly used antibiotics.ClfB gene deletion strain△clfB and the complemented strain C△clfB were successfully constructed.The growth curves of the deletion strain were almost consistent with those of the wild and complemented strains,and there was no significant difference.Compared with J57 and C△clfB,the hemoly ability and the athletic of △clfB decreased.In the condition of TritonX-100,the autolysis rate of △clfB was significantly lower than that of J57 and C△clfB(P＜0.01).Compared with J57 and C△clfB,the ability of △clfB to form biofilm was significantly lower than that of J57 and C△clfB(P＜0.05),and the content of extracellular DNA and protein in the biofilm was significantly decreased.In con-trast,the content of soluble polysaccharides was significantly increased(P＜0.05).Compared with J57 and C△clfB,△clfB was more sensitive to chloramphenicol,gentamicin,and kanamycin while more resistant to linezolid.ClfB gene is closely related to the autolysis,hemolytic activity,athlet-ic,and biofilm formation ability of Staphylococcus aureus,affecting the sensitivity of bacteria to certain antibiotics.

Objective To analyze the clinical application value of modified contrast agent injection protocol in computed tomography pulmonary angiography(CTPA)examinations.Methods A total of 124 patients with high clinical suspicion of pulmonary embolism(PE)who underwent CTPA were selected,and 104 patients were finally included in the study.These patients were randomly divided into traditional group and modified group based on different contrast agent injection protocols,with 52 patients in each group.The CT values,image noise,signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),visualized segment number,image score,contrast agent dosage,and radiation dose of pulmonary artery and its branches were compared between the two groups.Results There were no significant differences in age,body mass index(BMI),Qanadli embolism index,volume CT dose index(CTDIvol),dose length product(DLP),effective dose(ED),CT values of pulmonary artery and its branches,image noise,SNR and CNR between the two groups(P＞0.05).However,there were statistically significant differences in the subjective image score and contrast agent dosage between the two groups(P＜0.05).The subjective image score in the modified group was significantly higher than that in the traditional group,and the contrast agent dosage in the modified group was approximately half of that in the traditional group.Conclusion The modified contrast agent injection protocol in CTPA examinations can not only ensure the image quality of pulmonary artery and its branches meeting the diagnostic standards,but also significantly reduce the contrast agent dosage,which indicates a high clinical application value.

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.

Objective:To explore the effect of Shenxianling granules on the pharmacokinetics of ondansetron. Methods:A method for detecting the plasma concentration of ondansetron using highperformance liquid chromatography (HPLC) was established. The reliability of the method was validated through specificity, linear relationship, precision, stability, repeated experiments, and sample recovery rate testing. Thirty six healthy male New Zealand rabbits were randomly divided into 2 groups, with 18 rabbits in each group. Rabbits in the single ondansetron group (single drug group) received intravenous injection of ondansetron 0.92 mg/kg through the ear vein. Rabbits in the Shenxianling granules combined with ondansetron group (combination drug group) were firstly given 575 mg/kg of Shenxianling granules by gavage continuously for 10 days, and on the morning of the 11th day, ondansetron 0.92 mg/kg was intravenously injected. Blood samples were collected before administration and at 5 minutes, 10 minutes, 20 minutes, 30 minutes, 45 minutes, 1 hour, 2 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 10 hours and 24 hours after administration of ondansetron. The blood concentration of ondansetron was detected using HPLC method and pharmacokinetic parameters were calculate. Results:Two New Zealand rabbits in the combination drug group developed agitation and cough, and then died on the second and fifth day of gavage, respectively. Therefore a total of 18 and 16 rabbits in the single drug group and the combination drug group completed the experiment, respectively. After ondansetron administration, the plasma concentration of ondansetron increased rapidly in the single drug group and remained at low levels in the combination drug group. From 5 minutes to 10 hours after administration, the plasma concentration of ondansetron at the 13 blood sampling time points in the combination drug group was significantly lower than that in the single drug group, and the differences were statistically significant (all P<0.001). Compared with the single drug group, the plasma clearance half-life of ondansetron in the combination drug group was significantly prolonged, the peak time, peak concentration, concentration at the last time and area under the curve (AUC) were all significantly reduced, and the percen- tage of residual or extrapolated area to the overall AUC, apparent volume of distribution, and clearance/bioavailability ratio were significantly increased; the differences were statistically significant (all P<0.001). Conclusions:There is a significant interaction between Shenxianling granules and ondansetron, leading to a decreased plasma concentration of ondansetron. The mechanism may be related to Shenxianling granules altering the tissue distribution of ondansetron within the body.

This study aims to investigate the biological function of the Clumping factor B(clfB)gene in Staphylococcus aureus.The recombinant plasmid pBT2-△clfB was constructed and elec-troporated into Staphylococcus aureus J57 to delete clfB by homologous recombination.The ex-pression plasmid pLI50-clfB was constructed,modified,and electroporated into clfB gene deletion strain △clfB and constructed a complementation strain(C△clfB).J57,△clfB,and C△clfB were cultured at 37℃ for 12 h,and the growth curves of each strain were plotted.The hemolytic properties of each strain were analyzed by contact method,the motility of each strain on TSA plates was determined,and the autolysis rate of each strain under the action of TritonX-100 was determined.Crystal violet staining was used to detect each strain's biofilm formation ability,and biofilm components formed by each strain were quantitatively analyzed.The K-B method was used to determine the sensitivity of each strain to commonly used antibiotics.ClfB gene deletion strain△clfB and the complemented strain C△clfB were successfully constructed.The growth curves of the deletion strain were almost consistent with those of the wild and complemented strains,and there was no significant difference.Compared with J57 and C△clfB,the hemoly ability and the athletic of △clfB decreased.In the condition of TritonX-100,the autolysis rate of △clfB was significantly lower than that of J57 and C△clfB(P＜0.01).Compared with J57 and C△clfB,the ability of △clfB to form biofilm was significantly lower than that of J57 and C△clfB(P＜0.05),and the content of extracellular DNA and protein in the biofilm was significantly decreased.In con-trast,the content of soluble polysaccharides was significantly increased(P＜0.05).Compared with J57 and C△clfB,△clfB was more sensitive to chloramphenicol,gentamicin,and kanamycin while more resistant to linezolid.ClfB gene is closely related to the autolysis,hemolytic activity,athlet-ic,and biofilm formation ability of Staphylococcus aureus,affecting the sensitivity of bacteria to certain antibiotics.

To evaluate the efficacy and safety of dye-free submucosal injection solution for gastric endoscopic submucosal dissection (ESD), a retrospective cohort study was performed on data of inpatients with early gastric cancer and precancerous lesions who underwent ESD at the Digestive Endoscopy Center of Jiangsu Province Hospital of Traditional Chinese Medicine from January to December 2020. Cases were divided into dye-free submucosal injection solution group (the observation group) and dye-containing solution group (the control group). A total of 108 cases met the eligibility criteria for analysis (39 VS 69). Baseline characteristics were comparable between the two groups ( P>0.05). Compared with the control group, the observation group showed similar median procedure time (30.5 min VS 35.0 min), median dissection speed (0.3 cm2/min VS 0.4 cm2/min), mean volume of injection solution used (39.2 mL VS 38.8 mL), en bloc resection rate [100.0% (39/39) VS 98.6% (68/69)], and curative resection rate [97.4% (38/39) VS 97.1% (67/69)] (all P>0.05). Postoperative stay was 3.0±0.8 days in the observation group and 3.2±0.8 days in the control group ( t=-0.908, P=0.378). Delayed bleeding occurred in 3 (7.7%) patients VS 2 (2.9%) patients ( P=0.349), and postoperative infection occurred in 3 (7.7%) patients VS 8 (11.6%) patients ( P=0.743), respectively. In gastric ESD, dye-free submucosal injection solution demonstrates efficacy comparable with dye-containing solution and does not appreciably increase the incidence of intraoperative or postoperative complications.

Objective To explore the mechanism of malt alcohol extract improving depression-like behavior induced by CUMS in rats by regulating gut microbiota.Methods The depression model of rats was established using an 8-weeks CUMS procedure,and the administration group was given low(59.6 mg·kg-1)and high(178.8 mg·kg-1)doses of malt alcohol extract,respectively.The depression-like behavior of rats was evaluated by classic behavioral test.The composition of intestinal microbiota of rats was analyzed by 16S rRNA sequencing.The morphological changes of colon were observed by hematoxylin and eosin(HE),the expression of ZO-1 and Occludin in colon was detected by immunofluorescence(IF),and the expression of IL-10,IL-1βand 5-HT were detected by ELISA.Results The low dose of malt alcohol extract attenuated the depressive behavior and restored the expression of 5-HT in the brain of CUMS rats.16S rRNA sequencing results showed that the diversity and relative abundance of gut microbiota changed after treatment with the low dose of malt alcohol extract.ELISA results showed that the low dose of malt alcohol extract significantly reversed the CUMS-induced reduction of IL-10 and elevation of IL-1 β.HE results showed that the low dose of malt alcohol extract significantly ameliorated CUMS-induced structural damage in colon.IF results showed increased protain expression of intestinal epithelial barrier tight junction proteins ZO-1 and Occludin by the low dose of malt alcohol extract.Conclusion The low dose of malt alcohol extract can ameliorate CUMS-induced depressive-like behavior in rats by modulating intestinal flora,restoring 5-HT expression in the brain,inhibiting inflammation,and repairing the intestinal barrier.

Objective To explore the feasibility and safety of fastest recovery after surgery(FRAS)in laparoscopic surgery of gastrointestinal tumors.Methods The clinical data of patients undergoing laparoscopic surgery for gastrointestinal tumors under FRAS and enhanced recovery after surgery(ERAS)from Jan.2023 to May 2024 were collected,and perioperative safety and medical cost were analyzed.Results A total of 87 patients were enrolled,including 43 in the FRAS group and 44 in the ERAS group.Compared with the ERAS group,the FRAS group had significantly shorter surgical time(3.0[2.5,3.5]h vs 3.0[2.5,4.0]h),first postoperative movement time([2.85±4.29]h vs[20.18±6.13]h),first postoperative oral feeding time(2.0[2.0,3.0]h vs 24.0[15.0,48.0]h),postoperative hospital stay(24.0[20.0,40.0]h vs 192.0[150.0,216.0]h),lower hospitalization costs(50 515.61[46 650.44,56 827.12]yuan vs 65 555.09[58 683.21,86 239.02]yuan),and lower medication costs(2 671.09[2 063.31,3 127.09]yuan vs 7 326.90[5 104.66,10 674.26]yuan)(all P＜0.05).Conclusion It is safe and feasible to use FRAS during the perioperative period of laparoscopic radical gastrectomy for gastrointestinal tumors,and FRAS can also reduce the costs of hospitalization and medications.

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.

Objective To analyze the clinical application value of modified contrast agent injection protocol in computed tomography pulmonary angiography(CTPA)examinations.Methods A total of 124 patients with high clinical suspicion of pulmonary embolism(PE)who underwent CTPA were selected,and 104 patients were finally included in the study.These patients were randomly divided into traditional group and modified group based on different contrast agent injection protocols,with 52 patients in each group.The CT values,image noise,signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),visualized segment number,image score,contrast agent dosage,and radiation dose of pulmonary artery and its branches were compared between the two groups.Results There were no significant differences in age,body mass index(BMI),Qanadli embolism index,volume CT dose index(CTDIvol),dose length product(DLP),effective dose(ED),CT values of pulmonary artery and its branches,image noise,SNR and CNR between the two groups(P＞0.05).However,there were statistically significant differences in the subjective image score and contrast agent dosage between the two groups(P＜0.05).The subjective image score in the modified group was significantly higher than that in the traditional group,and the contrast agent dosage in the modified group was approximately half of that in the traditional group.Conclusion The modified contrast agent injection protocol in CTPA examinations can not only ensure the image quality of pulmonary artery and its branches meeting the diagnostic standards,but also significantly reduce the contrast agent dosage,which indicates a high clinical application value.