Objective To analyze the influencing factors for catheter-associated infection(CAI)in chemotherapy treated patients after indwelling peripherally inserted central catheter(PICC)based on a random forest model.Methods 400 tumor patients who received chemotherapy and PICC were selected and divided into the training set(n=300)and the test set(n=100)in a 3∶1 ratio through computer-generated random number.Patients in the training set were subdivided into the non-infection group and the infection group based on the occurrence of infec-tion.Clinical data from two groups of patients were compared.Influencing factors for the occurrence of CAI after PICC were analyzed with multivariate logistic regression model and the integrated classification algorithm of random forest model,and the predictive performance of the two methods was compared.Results Among 300 chemotherapy treated patients in the training set,32 cases(10.67％)experienced CAI.Compared with the non-infection group,patients in the infection group had more single punctures for catheterization,longer PICC retention time,larger pro-portion of catheter movement,larger proportion of complication with diabetes,higher frequency of dressing chan-ges,lower white blood cell count and immune function(all P＜0.05).PICC retention time,catheter movement,complication with diabetes,dressing change frequency,white blood cell(WBC)and immune function were inde-pendent influencing factors for CAI after PICC(all P＜0.05).The random forest model showed that ranking by the importance of different influencing factors was as following:PICC retention time,catheter movement,complication with diabetes,WBC,dressing change frequency and immune function.The integrated classification algorithm of random forest model for predicting the occurrence of CAI in chemotherapy treated patients showed that the area un-der the receiver operating characteristic(ROC)curve(AUC)was 0.872,which had better prediction performance compared with the logistic regression model(AUC=0.791).Conclusion PICC retention time,catheter movement,complicated with diabetes,dressing change frequency,WBC level and immune function are independent influencing factors for CAI in chemotherapy treated patients.The integrated classification algorithm of random forest model can be used to predict CAI in chemotherapy treated patients,and its prediction performance is better than that of the logistic regression model.

The growth of three plague phages from Qinghai Plateau in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,PTB5,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were detected through a micromethod based on the OmniLogTM microbial identification system and by the drop method,to provide a scientific basis for future ecological studies and classification based on the host range.For plague vaccine strains EV76 and 614F,successful phage infection and subsequent phage growth were observed in the host bacte-rium.Diminished bacterial growth and respiration and a concomitant decrease in color were observed with the OmniLogTM mi-crobial identification system at 33 ℃ for 48 h.Yersinia pseudotuberculosis PTB5 was sensitive to Yersinia pestis phage 476,but Yersinia pseudotuberculosis PST5 was insensitive to phage 087 and 072204.Three strains of non-Yersinia pestis(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersinia enterocolitica 52302-2)were insensitive to Yersinia pestis pha-ges 087,072204,and 476 showed similar growth curves.The growth of phages 476 and 087,as determined with the drop method,in two Yersinia pestis strains(plague vaccine strains EV76 and 614F)and four non-Yersinia pestis strains(Yersinia pseudotuberculosis PTB3,Escherichia coli V517,and Yersin-ia enterocolitica 52302-2)showed the same results at 37 ℃,on the basis of comparisons with the OmniLogTM microbial i-dentification system;in contrast,phages 072204 did not show plaques on solid medium at 37 ℃ with plague vaccine strains EV76 and 614F.Determination based on the OmniLogTM detection system can be used as an alternative to the traditional determination of the host range,thus providing favorable application val-ue for determining the interaction between the phage and host bacteria.

Damarane-type triterpene saponins are the main active ingredients in Gynostemma pentaphyllum (Thunb.) Makino. By using D101 macroporous adsorption resin and silica gel open-columns, C18 medium-pressure column chromatography, and preparative high performance liquid chromatography, we isolated four compounds from the leaves of G. pentaphyllum planted in Guangxi Zhuang Autonomous Region. Their structures were determined by comprehensive analyses of MS, NMR data and circular dichroism spectroscopy and identified as (3β,12β)-dihydroxy-25-peroxyhydrohydrodammarane-20,23-diene-3-O-[β-D-glucopyranosyl(1→2)]-β-D-glucopyranoside (1), (3β,12β,24S)-trihydroxydammarane-20,25-diene-3-O-[β-D-glucopyranosyl(1→2)]-β-D-glucopyranoside (2), (3β,20α)-dihydroxy-24-en-12β,22S-epoxydammarane-3-O-[β-D-glucopyranosyl(1→2)]-β-D-glucopyranoside (3), (3β,12β,20S)-trihydroxydammarane-24-en-3-O-[6-O-acetyl-β-D-glucopyranosyl(1→2)-β-D-glucopyranosyl]-20-O-β-D-xylopyranosyl(1→3)-α-L-rhamnopyranosyl (1→6)-β-D-glucopyranoside (4). Compounds 1-4 are new dammarane-type triterpene saponins.

Background::Clinical opportunistic screening is a cost-effective cancer screening modality. This study aimed to establish an easy-to-use diagnostic model serving as a risk stratification tool for identification of individuals with malignant gastric lesions for opportunistic screening.Methods::We developed a questionnaire-based diagnostic model using a joint dataset including two clinical cohorts from northern and southern China. The cohorts consisted of 17,360 outpatients who had undergone upper gastrointestinal endoscopic examination in endoscopic clinics. The final model was derived based on unconditional logistic regression, and predictors were selected according to the Akaike information criterion. External validation was carried out with 32,614 participants from a community-based randomized controlled trial.Results::This questionnaire-based diagnostic model for malignant gastric lesions had eight predictors, including advanced age, male gender, family history of gastric cancer, low body mass index, unexplained weight loss, consumption of leftover food, consumption of preserved food, and epigastric pain. This model showed high discriminative power in the development set with an area under the receiver operating characteristic curve (AUC) of 0.791 (95% confidence interval [CI]: 0.750–0.831). External validation of the model in the general population generated an AUC of 0.696 (95% CI: 0.570–0.822). This model showed an ideal ability for enriching prevalent malignant gastric lesions when applied to various scenarios.Conclusion::This easy-to-use questionnaire-based model for diagnosis of prevalent malignant gastric lesions may serve as an effective prescreening tool in clinical opportunistic screening for gastric cancer.

Objective To investigate the correlation between the level of N-terminal pro-Brain natriuretic peptide(NT-proBNP)and cardiorespiratory fitness following acute exposure to high altitude.Methods Forty-six subjects were recruited from the Second Affiliated Hospital of Army Medical University in June 2022,including 19 males and 27 females.After completing cardiopulmonary exercise test(CPET),serological detection of myocardial cell-related markers,and multiple metabolites at a plain altitude(300 meters above sea level),all subjects flew to a high-altitude location(3900 meters above sea level).Biomarker testing and CPET were repeated on the second and third days after arrival at high altitude.Changes in serum biomarker and key CPET indicators before and after rapid ascent to high altitude were compared,and the correlation between serum levels of various myocardial cell-related markers and metabolites and high altitude cardiorespiratory fitness was analyzed.Results Compared with the plain altitude,there was a significant decrease in maximal oxygen uptake after rapid ascent to high altitude[(25.41±6.20)ml/(kg.min)vs.(30.17±5.01)ml/(kg.min),P<0.001].Serum levels of NT-proBNP,Epinephrine(E),plasma renin activity(PRA),angiotensin Ⅱ(Ang Ⅱ),angiotensin-converting enzyme 2(ACE2)and leptin(LEP)significantly increased,with all differences being statistically significant(P<0.05)after acute high altitude exposure.In contrast,no statistically significant differences were observed for creatine kinase MB(CK-MB),cardiac troponin I(cTnI),myoglobin(Myo)and norepinephrine(NE)(P>0.05).Correlation analysis showed a significant negative correlation between NT-proBNP at plain altitude(r=-0.768,P<0.001)and at high altitude(r=-0.791,P<0.001)with maximal oxygen uptake at high altitude.Multivariate linear regression analysis indicated that maximal oxygen uptake at plain altitude(t=2.069,P=0.045),NT-proBNP at plain altitude(t=-2.436,P=0.020)and at high altitude(t=-3.578,P=0.001)were independent influencing factors of cardiorespiratory fitness at high altitude.Conclusion Cardiorespiratory fitness significantly decreases after rapid ascent to high altitude,and the baseline NT-proBNP level at plain altitude is closely related to cardiorespiratory fitness at high altitude,making it a potential predictor indicator for high altitude cardiorespiratory fitness.

Objective To explore medium and long term efficacy of oblique lateral interbody fusion(OLIF)in treating lumbar specific infection.Methods From October 2017 to January 2021,24 patients with lumbar specific infection were treated by OLIF combined with vertebral screw internal fixation,including 15 males and 9 females,aged from 27 to 61 years old with an average of(43.0±15.0)years old;the courses of disease ranged from 6 to 24 months with an average of(14.0±7.0)months;7 patients with L2-L3,12 patients with L3-L4 and 5 patients with L4-L5;19 patients with tuberculosis infection and 5 patients with brucella infection.The amount of intraoperative blood loss,operative time and complications were recorded,and erythro-cyte sedimentation rate(ESR),C-reactive protein(CRP),visual analogue scale(VAS),Japanese Orthopaedic Association(JOA)score and American Spinal Injury Association(ASIA)rating were compared before and one month after opertaion.Re-sults All patients were followed up from 9 to 24 months with an average of(13.0±6.0)months.Operative time was(132.5±21.4)min,and intraoperative blood loss was(227.3±43.1)ml.ESR and CRP were decreased from(82.34±18.62)mmol·h-1 and(53.08±21.84)mg·L-1 before operation to(33.52±17.31)mmol·h-1 and(15.48±8.36)mg·L-1 at one month after opera-tion,respectively(P＜0.05).VAS was decreased from(7.52±1.36)before opertaion to(1.74±0.87)at one month after opera-tion(P＜0.05).JOA was increased from(17.86±3.95)before operation to(24.72±3.19)at one month after operation(P＜0.05).Four patients had neurological symptoms before operation,and were classified to grade D according to ASIA classifica-tion,who were recovered to grade E at 1 month after operation.One patient was suffered from psoas major muscle injury after operation,and returned to normal at 3 weeks.One patient was suffered from abdominal distension and difficulty in defecation,and relieved after gastrointestinal decompression and enema.No complications such as abdominal organ injury and poor wound healing occurred in all patients.Conclusion OLIF combined with vertebral screw internal fixation is a new minimally invasive surgical method for the treatment of lumbar specific infection,especially the lesion located on the middle lumbar vertebra.It has advantages of less trauma,short operation time,less blood loss,convenient operation,complete removal of the lesion,safety and effectiveness,and has good medium-and long-term efficacy for lumbar specific infection.

Objective To verify the safety and efficacy of a new portable extracorporeal membrane oxygenation(ECMO)system(Xijing Advanced Life Support System JC-Ⅲ)in large animals.Methods A total of 10 healthy small fat-tail sheep underwent veno-arterial extracorporeal membrane oxygenation(VA-ECMO)support by carotid arterial-jugular catheterization to evaluate the performance of the JC-Ⅲ ECMO system.Systemic anticoagulation was achieved by continuous infusion of heparin.Active coagulation time(ACT)was recorded every 2 hours during the experiment,and the ACT was maintained between 200-250 s.Centrifugal pump speed is set at 3 000-3 500 r/min.The changes of hemoglobin,blood cell counts,hematocrit,liver and kidney function were monitored before and 24 h after ECMO initiation,respectively.After the experiment,the pump and oxygenator were dissected to probe the thrombosis.Results The success rate of VA-ECMO operation was 100％,and there was no hemolysis,pump thrombosis and oxygenator thrombosis after 24 h of ECMO.Before and after the operation,there were no significant changes in indicators such as hemoglobin content,white blood cell counts,platelet counts,alanine aminotransferase concentration,aspartate aminotransferase concentration,urea,creatinine,high-sensitivity troponin Ⅰ,and N-terminal pro-brain natriuretic peptide(all P＞0.05).Conclusions This in vivo study confirms that Xijing Advanced Life support System JC-Ⅲ is safe and effective.

Objective:To investigate the clinical characteristics,coexisting gene mutations and prognosis of acute myeloid leukemia(AML)patients with GATA2 gene mutation.Methods:The clinical data of 370 newly diagnosed AML patients treated in our hospital from January 2008 to January 2021 was analyzed retrospectively,the next-generation sequencing technology was used to detect the mutated genes in those patients.The clinical characteristics of AML patients with GATA2 mutations,the co-mutated genes of GATA2 mutations,and the effect of GATA2 mutation on prognosis were analyzed.Results:A total of 23 patients(6.2％)with GATA2 mutation was detected in 370 AML patients.Compared with GATA2 non-mutation group,patients in GATA2 mutation group were mostly normal karyotypes(P=0.037)and in low-risk cytogenetic stratification(P=0.028).The incidence of CEBPAdm and NRAS in GATA2 mutation group was significantly higher than that in GATA2 non-mutation group(P=0.010,P=0.009).There were no statistically significant differences between the two groups in terms of sex,age,white blood cell count(WBC),platelet count,hemoglobin,bone marrow(BM)blast,induction chemotherapy regimen and CR rate(P＞0.05).Among the 23 patients with GATA2 mutation,the most common co-mutated genes were CEBPAdm,NRAS(both 39.1％),NPM1,FLT3,TET2,WT1(all 17.4％),ASXL1 and IDH1(both 13.0％).Survival analysis showed that there was no statistical difference in 5-year overall survival(OS)and leukemia-free survival(LFS)rates between patients with and without GATA2 mutations in whole cohort(n=370)(P=0.306,P=0.308).Among 306 patients without CEBPAdm,the 5-year OS and LFS rates in GATA2 mutation group showed an increasing trend compared with GATA2 non-mutation group,but the difference was not statistically significant(P=0.092,P=0.056).Among 64 patients with CEBPAdm,there was no statistically significant difference in 5-year OS rate between the GATA2 mutation group and the GATA2 non-mutation group(P=0.104),but the 5-year LFS rate of the GATA2 mutation group was significantly decreased(P=0.047).Among the 23 patients with GATA2 mutation,16 cases received the"3+7"induction regimen,of which 12 cases received allogeneic hematopoietic stem cell transplantation(allo-HSCT);7 cases received the"DCAG"induction regimen,of which 3 cases received allo-HSCT.The CR rate was not statistically different between the"3+7"regimen group and the"DCAG"regimen group(P=1.000).The 5-year OS rate and LFS rate in the transplantation group were significantly higher than the chemotherapy group(P=0.021,P=0.020).Conclusion:GATA2 mutation is more common in AML patients with normal karyotype and low-risk cytogenetic stratification,and it is significantly associated with CEBPAdm and NRAS co-mutations.The prognostic significance of GATA2 is influenced by CEBPAdm.The choice of"3+7"or"DCAG"induction regimen in patients with GATA2 mutation does not affect their CR rate,while the choice of allo-HSCT can significantly improved the prognosis compared with chemotherapy only.

Objective:To investigate the effect of CD8+CD28-T cells on acute graft-versus-host disease(aGVHD)after haploidentical hematopoietic stem cell transplantation(haplo-HSCT).Methods:The relationship between absolute count of CD8+CD28-T cells and aGVHD in 60 patients with malignant hematological diseases was retrospectively analyzed after haplo-HSCT,and the differences in the incidence rate of chronic graft-versus host disease(cGVHD),infection and prognosis between different CD8+CD28-T absolute cells count groups were compared.Results:aGVHD occurred in 40 of 60 patients after haplo-HSCT,with an incidence rate of 66.67％.The median occurrence time of aGVHD was 32.5(20-100)days.At 30 days after the transplantation,the absolute count of CD8+CD28-T cells of aGVHD group was significantly lower than that of non-aGVHD group(P=0.03).Thus the absolute count of CD8+CD28-T cells at 30 days after transplantation can be used to predict the occurrence of aGVHD to some extent.At 30 days after transplantation,the incidence rate of aGVHD in the low cell count group(CD8+CD28-T cells absolute count＜0.06/μl)was significantly higher than that in the high cell count group(CD8+CD28-T cells absolute count ≥0.06/μl,P=0.011).Multivariate Cox regression analysis further confirmed that the absolute count of CD8+CD28-T cells at 30 days after transplantation was an independent risk factor for aGVHD,and the risk of aGVHD in the low cell count group was 2.222 times higher than that in the high cell count group(P=0.015).The incidence of cGVHD,fungal infection,EBV infection and CMV infection were not significantly different between the two groups with different CD8+CD28-T cells absolute count.The overall survival,non-recurrent mortality and relapse rates were not significantly different between different CD8+CD28-T cells absolute count groups.Conclusion:Patients with delayed CD8+CD28-T cells reconstitution after haplo-HSCT are more likely to develop aGVHD,and the absolute count of CD8+CD28-T cells can be used to predict the incidence of aGVHD to some extent.The absolute count of CD8+CD28-T cells after haplo-HSCT was not associated with cGVHD,fungal infection,EBV infection,and CMV infection,and was also not significantly associated with the prognosis after transplantation.

Objective To investigate the effect of microglial derived extracellular vesicles on neuronal damage in the context of heat stress.Methods After BV2 microglial cells were exposed to heat stress,the supernatant was collected and subjected to ultracentrifugation at different speeds to obtain large and small vesicles,respectively.Nano Particle Tracking and Zeta Potential Distribution Analyzer was used to measure and analyze the size distribution of the large vesicles and small vesicles.Western blotting was used to detect the expression of specific vesicle surface markers,TSG101,CD63 and flotillin-1.Microglial extracellular vesicles were labeled with PKH67 dye and then co-cultured with N2a cells to examine the uptake by capacity the neurons.After large and small vesicles derived from microglia after heat stress stimulation were co-cultured with N2a cells,respectively,CCK-8 assay,lactate dehydrogenase (LDH)assay,Trypan blue staining and TUNEL assay were employed to evaluate heat stress induced neuronal damage.Results The small vesicles were in a particle size of 30～120 nm,and highly expressed TSG101 and CD63,whereas the large vesicles,in a size of 90～1000 nm,highly expressed flotillin-1.The BV2-derived extracellular vesicles could be taken up by N2a cells and were proved to be involved in the modulation of N2a cell injury caused by heat stress.CCK-8 assay showed that both large and small vesicles of microglial cells inhibited the viability of N2a cells after heat exposure (P<0.05).The results of LDH assay,Trypan blue staining and TUNEL assay showed that both large (P<0.05)and small vesicles (P<0.01)significantly enhanced the LDH release,blue stain intensity and apoptosis of N2a cells after heat exposure,and the release,intensity and apoptosis were stronger in the cells treated with small vesicles than those group of large vesicles.Conclusion Microglia aggravate heat stress-induced neuronal damage through releasing extracellular vesicles.