1.Association between lactate-to-albumin ratio and prognosis of patients with sepsis:a retrospective analysis based on Medical Information Mart for Intensive Care-Ⅳ
Tianyun ZHOU ; Yanfei SHEN ; Guolong CAI ; Huihui ZHANG ; Qianghong XU
Chinese Journal of Integrated Traditional and Western Medicine in Intensive and Critical Care 2025;32(1):25-30
Objective To analysis the relationship between the lactate-to-albumin ratio(LAR)and the 28-day prognosis in patients with sepsis.Methods Based on the Medical Information Mart for Intensive Care-Ⅳ(MIMIC-Ⅳ)database,patients with sepsis aged≥18 years were selected.Patients were divided into survival and death groups according to their 28-day prognosis.The LAR was divided into quartiles:Q1(LAR<0.45),Q2(0.45≤LAR<0.70),Q3(0.70≤LAR<1.18),and Q4(LAR≥1.18);and into two groups based on the median LAR:low LAR group(LAR≤0.70)and high LAR group(LAR>0.70).Demographic characteristics,comorbidities,laboratory indicators,clinical treatments,and disease severity scores of patients were extracted.LAR was included as a continuous variable and a four-category variable in multiple Logistic regression models,with trend tests performed.Subgroup analyses were conducted based on gender,age,comorbidities,and sequential organ failure assessment(SOFA)score.Receiver operator characteristic curve(ROC curves)were plotted to analyze the predictive efficacy of lactate,albumin(Alb),LAR and SOFA score for the prognosis of sepsis patients.Kaplan-Meier survival curves were plotted to compare the difference of 28-day cumulative survival rates of sepsis patients in the high and low LAR groups.Results A total of 9 169 patients with sepsis were included,with 6 799 in the survival group and 2 370 in the death group.Compared with the survival group,the death group had older age[years:70.80(58.64,82.25)vs.65.07(53.56,76.92)],higher levels of potassium,creatinine,blood urea nitrogen(BUN),white blood cell count(WBC),lactate,LAR,SOFA score,simplified acute physiology scoreⅡ(SAPSⅡ),and higher proportions of chronic obstructive pulmonary disease(COPD),heart failure,use of vasopressors within 48 hours,and continuous renal replacement therapy(CRRT)[potassium(mmol/L):5.0(4.5,5.7)vs.4.8(4.4,5.4),creatinine(μmol/L):132.60(88.40,212.16)vs.97.24(70.72,159.12),BUN(mmol/L):11.42(7.14,18.56)vs.7.85(5.25,13.57),WBC(×109/L):13.1(8.7,19.1)vs.11.4(7.6,16.4),lactate(mmol/L):2.9(1.8,5.1)vs.2.0(1.4,3.1),LAR:1.03(0.63,1.88)vs.0.62(0.42,0.98),SOFA score:9(6,12)vs.6(4,8),SAPSⅡscore:52(42,64)vs.38(30,47),COPD:8.19%(194/2 370)vs.6.57%(447/6 799),heart failure:29.96%(710/2 370)vs.26.31%(1 789/6 799),use of vasopressors within 48 hours:62.19%(1 474/2 370)vs.37.56%(2 554/6 799),CRRT:19.45%(461/2 370)vs.9.56%(650/6 799),all P<0.05],while lower levels of body weight,chloride,calcium,hemoglobin(Hb),platelet count(PLT),Alb and lower proportions of hypertension were observed in the death group[body weight(kg):75.8(63.6,92.3)vs.78.7(66.5,95.0),chloride(mmol/L):104(98,109)vs.104(100,108),calcium(mmol/L):1.07(1.00,1.15)vs.1.09(1.03,1.15),Hb(g/L):103(87,120)vs.105(90,121),PLT(×109/L):173(104,246)vs.174(118,243),Alb(g/L):29(24,34)vs.33(28,37),hypertension:35.36%(838/2 370)vs.38.34%(2 607/6 799),all P<0.05].In the Logistic regression model adjusted for all confounding factors,the odds ratio(OR)and 95%confidence interval(95%CI)of LAR were 1.74(1.64-1.85),P<0.001;when LAR was treated as a four-category variable,the OR values of Q2,Q3,and Q4 increased progressively compared with Q1,being 1.49(1.22-1.82),2.27(1.88-2.75),and 5.05(4.20-6.08),respectively,P<0.001.Subgroup analyses showed that LAR was an independent risk factor for the 28-day prognosis of sepsis in different subgroups based on gender,age,comorbidities,and SOFA score(all P<0.001),with no interaction effects with the subgroup variables(all P>0.05).ROC curve analysis showed that the AUC of LAR predicted the 28-day prognosis of patients with sepsis was 0.688(0.675-0.700),higher than that of lactate[0.655(0.642-0.668)]and Alb[0.636(0.623-0.649)],both P<0.001,and not significantly lower than that of SOFA score[0.699(0.687-0.712),P=0.108].Kaplan-Meier survival analysis showed that the 28-day cumulative survival rate was significantly higher in the low LAR group than in the high LAR group(Log-Rank test:χ2=533.24,P<0.001).Conclusion LAR is an independent risk factor for the 28-day prognosis of sepsis patients.Higher LAR is associated with adverse outcomes,and its predictive efficacy is superior to that of lactate and albumin.
2.Association between lactate-to-albumin ratio and prognosis of patients with sepsis:a retrospective analysis based on Medical Information Mart for Intensive Care-Ⅳ
Tianyun ZHOU ; Yanfei SHEN ; Guolong CAI ; Huihui ZHANG ; Qianghong XU
Chinese Journal of Integrated Traditional and Western Medicine in Intensive and Critical Care 2025;32(1):25-30
Objective To analysis the relationship between the lactate-to-albumin ratio(LAR)and the 28-day prognosis in patients with sepsis.Methods Based on the Medical Information Mart for Intensive Care-Ⅳ(MIMIC-Ⅳ)database,patients with sepsis aged≥18 years were selected.Patients were divided into survival and death groups according to their 28-day prognosis.The LAR was divided into quartiles:Q1(LAR<0.45),Q2(0.45≤LAR<0.70),Q3(0.70≤LAR<1.18),and Q4(LAR≥1.18);and into two groups based on the median LAR:low LAR group(LAR≤0.70)and high LAR group(LAR>0.70).Demographic characteristics,comorbidities,laboratory indicators,clinical treatments,and disease severity scores of patients were extracted.LAR was included as a continuous variable and a four-category variable in multiple Logistic regression models,with trend tests performed.Subgroup analyses were conducted based on gender,age,comorbidities,and sequential organ failure assessment(SOFA)score.Receiver operator characteristic curve(ROC curves)were plotted to analyze the predictive efficacy of lactate,albumin(Alb),LAR and SOFA score for the prognosis of sepsis patients.Kaplan-Meier survival curves were plotted to compare the difference of 28-day cumulative survival rates of sepsis patients in the high and low LAR groups.Results A total of 9 169 patients with sepsis were included,with 6 799 in the survival group and 2 370 in the death group.Compared with the survival group,the death group had older age[years:70.80(58.64,82.25)vs.65.07(53.56,76.92)],higher levels of potassium,creatinine,blood urea nitrogen(BUN),white blood cell count(WBC),lactate,LAR,SOFA score,simplified acute physiology scoreⅡ(SAPSⅡ),and higher proportions of chronic obstructive pulmonary disease(COPD),heart failure,use of vasopressors within 48 hours,and continuous renal replacement therapy(CRRT)[potassium(mmol/L):5.0(4.5,5.7)vs.4.8(4.4,5.4),creatinine(μmol/L):132.60(88.40,212.16)vs.97.24(70.72,159.12),BUN(mmol/L):11.42(7.14,18.56)vs.7.85(5.25,13.57),WBC(×109/L):13.1(8.7,19.1)vs.11.4(7.6,16.4),lactate(mmol/L):2.9(1.8,5.1)vs.2.0(1.4,3.1),LAR:1.03(0.63,1.88)vs.0.62(0.42,0.98),SOFA score:9(6,12)vs.6(4,8),SAPSⅡscore:52(42,64)vs.38(30,47),COPD:8.19%(194/2 370)vs.6.57%(447/6 799),heart failure:29.96%(710/2 370)vs.26.31%(1 789/6 799),use of vasopressors within 48 hours:62.19%(1 474/2 370)vs.37.56%(2 554/6 799),CRRT:19.45%(461/2 370)vs.9.56%(650/6 799),all P<0.05],while lower levels of body weight,chloride,calcium,hemoglobin(Hb),platelet count(PLT),Alb and lower proportions of hypertension were observed in the death group[body weight(kg):75.8(63.6,92.3)vs.78.7(66.5,95.0),chloride(mmol/L):104(98,109)vs.104(100,108),calcium(mmol/L):1.07(1.00,1.15)vs.1.09(1.03,1.15),Hb(g/L):103(87,120)vs.105(90,121),PLT(×109/L):173(104,246)vs.174(118,243),Alb(g/L):29(24,34)vs.33(28,37),hypertension:35.36%(838/2 370)vs.38.34%(2 607/6 799),all P<0.05].In the Logistic regression model adjusted for all confounding factors,the odds ratio(OR)and 95%confidence interval(95%CI)of LAR were 1.74(1.64-1.85),P<0.001;when LAR was treated as a four-category variable,the OR values of Q2,Q3,and Q4 increased progressively compared with Q1,being 1.49(1.22-1.82),2.27(1.88-2.75),and 5.05(4.20-6.08),respectively,P<0.001.Subgroup analyses showed that LAR was an independent risk factor for the 28-day prognosis of sepsis in different subgroups based on gender,age,comorbidities,and SOFA score(all P<0.001),with no interaction effects with the subgroup variables(all P>0.05).ROC curve analysis showed that the AUC of LAR predicted the 28-day prognosis of patients with sepsis was 0.688(0.675-0.700),higher than that of lactate[0.655(0.642-0.668)]and Alb[0.636(0.623-0.649)],both P<0.001,and not significantly lower than that of SOFA score[0.699(0.687-0.712),P=0.108].Kaplan-Meier survival analysis showed that the 28-day cumulative survival rate was significantly higher in the low LAR group than in the high LAR group(Log-Rank test:χ2=533.24,P<0.001).Conclusion LAR is an independent risk factor for the 28-day prognosis of sepsis patients.Higher LAR is associated with adverse outcomes,and its predictive efficacy is superior to that of lactate and albumin.
3.Effects of Gentiopicroside on the Apoptosis of Human Pancreatic Cancer Cells PANC- 1 and IL- 6/JAK2/STAT3 Signaling Pathway
Song MENG ; Yaozhu ZHOU ; Yongchao MA ; Songtao XU ; Shaoju JIN
China Pharmacy 2020;31(15):1836-1841
OBJECTIVE:To study the effects of gentiopicroside on the apo ptosis o f human pancreatic cancer cells PANC- 1,and to explore its mechanism from the perspective of IL- 6/JAK2/STAT3 signaling pathway. METHODS :Using PANC- 1 cells as model , the proliferation inhibition rate of cells was tested by MTT assay after treated with 0(negative contro ),2,4,8,16,32,64,128 mg/L gentiopicroside for 72 h and IC 50 were calculated. The cells were divided into negative control group ,gemcitabine group (positive control,4 mg/L)and gentiopicroside low-concentration ,medium-concentration and high-concentration groups (15,30,60 mg/L). After cultured for 1,3,5,7 d,Trypan blue exclusion staining was used to count the survival cell ,and the growth of cells was investigated. After cultured for 72 h,colony formation assay was used to observe colony formation rate of cells ;the apoptotic rate of cells was detected by Hoechst 33258 staining;the mRNA and protein expressions of IL- 6,JAK2,STAT3 in cells were detected by RT-PCR and Western blotting assay. RESULTS :4-28 mg/L gentiopicroside could inhibit the proliferation of cells (P<0.05 or P< 0.01),in concentration dependent trend ;IC50 was 9.54 mg/L. Compared with negative control group ,survival cell count (cultured from 3,5,7 d),mRNA and protein expressions of IL- 6,JAK2 and STAT 3 in cells were decreased significantly in gemcitabine group , gentiopicroside medium-concentration and high-concentration groups (P<0.05 or P<0.01),while the apoptotic rate was increased significantly (P<0.01). The colony formation rate of cellswere decreased significantly in gemcitabine group and gentiopicroside high-concentration group (P<0.01). mail:hb.gz@163.com Compared with gemcitabine group ,there was no statistical significance in above indexes of gentiopicroside high- 6716008。 concentration group (P>0.05). CONC LUSIONS:30,60 mg/L gentiopicroside could inhibit the proliferation and induce apoptosis of PANC- 1 cells,and 60 mg/L gentiopicroside is similar to gemcitabine in the effects. Its mechanism may be related to inhibiting the activation of IL- 6/JAK2/STAT3 signaling pathway.
4.Investigation of nurses' attitude towards open visitation policy in intensive care unit and analysis of influence factors
Fang CHEN ; Qi REN ; Caixia LIU ; Juan LIN ; Huijuan ZHANG ; Yuyi ZHOU ; Guolong CAI
Chinese Critical Care Medicine 2020;32(8):998-1002
Objective:To investigate the nurses' attitude towards open visitation policy in intensive care unit (ICU) and its potential influence factors, and further to provide evidence for carrying out this policy in ICU.Methods:A self-designed, anonymous online questionnaire of "attitude of ICU nurses to open visiting system in ICU" was performed in 31 provinces, autonomous regions and municipalities in China from October to December 2019, using convenient sampling method approach. Only nurses working in ICU (including specialized ICU, but excluding the critical ward in general ward) and willing to participate in the survey were included. The survey included 35 items, including the general information of each participant, the attitude towards the implementation of the open visitation system in ICU and its potential influencing factors. Ordinal Logistic regression analysis was used to identify the significant influencing factors.Results:A total of 1 558 questionnaires were sent out and 1 546 effective questionnaires were retrieved, with a response rate of 99.2%. Overall, 32.2% of them agreed with the policy, 41.3% of them disagree with the policy and 26.5% of them were uncertain. The Ordinal Logistic regression analysis showed that the independent influencing factors of ICU nurses' attitude towards open visitation policy including the possibility of increasing healthcare-associated infection [disagree: β = 1.327, 95% confidence interval (95% CI) was 0.242 to 2.413, P = 0.017; uncertain: β = 0.697, 95% CI was 0.244 to 1.151, P = 0.003], the improvement of nurses' job satisfaction (disagree: β = -1.406, 95% CI was -1.750 to -1.062, P = 0.000; uncertain: β = -0.748, 95% CI was -1.030 to -0.466, P = 0.000), the information support for medical staffs from family members (disagree: β = -0.644, 95% CI was -1.048 to -0.240, P = 0.002; uncertain: β = -0.422, 95% CI was -0.721 to -0.124, P = 0.006), the feasibility that the family members can assist the nurses in the basic nursing for patients (uncertain: β = -0.465, 95% CI was -0.729 to -0.202, P = 0.001), reducing the time that a nurse spent on caring for the patients (uncertain: β = 0.349, 95% CI was 0.052 to 0.646, P = 0.021), improving early rehabilitation (disagree: β = -0.593, 95% CI was -1.166 to -0.019, P = 0.043), and getting psychological support for patients from family members (disagree: β = 1.293, 95% CI was 0.426 to 2.159, P = 0.003), family members' satisfaction (disagree: β = -0.981, 95% CI was -1.431 to -0.531, P = 0.000). Conclusion:ICU nurses in China have realized that open visitation policy has positive effect on patients' early rehabilitation, willing to live and satisfaction; meanwhile, this policy may need more improvement in many ways such as healthcare-associated infection control, disinfection and isolation, allocation of human resources and time spent treating and caring for patients.
5.The prognostic role of the programmed death-1 expression on T lymphocytes in septic patients
Chang XU ; Li LI ; Junhai ZHEN ; Jia ZHOU ; Shijin GONG ; Guolong CAI ; Jing YAN
Chinese Journal of Internal Medicine 2020;59(10):796-800
Objective:To investigate the value of programmed death-1(PD-1) expression on the T lymphocytes for the prognosis of septic patients.Methods:From September 2017 to May 2019, septic patients were included in Department of Intensive Care Unit at 6 hospitals. The PD-1 expression on T cells were measured by flow cytometry. Logistic regression was conducted to analyze independent risk factors related to death within 28 days,and receiver operating characteristic curve(ROC) was conducted to evaluate the prognostic value of PD-1 expression on T cells in septic patients.Results:A total of 64 septic patients were enrolled to this study,including 32 survivors and 32 deaths. The PD-1 expression on T cells in the death group was significantly higher than that in the surviving group ( P<0.05). Correlation analysis showed that the percentages of PD-1 +/CD3 +T cells and PD-1 +/CD8 +T cells were positively correlated with procalciton in ( r=0.313, P =0.015; r=0.375, P=0.003), logistic regression analysis showed that the percentages of PD-1 +/CD3 +,PD-1 +/CD4 +,PD-1 +/CD8 +T cells were independent risk factors for the death of sepsis patients. The percentage of PD-1 +/CD3 +T cell was 3.63%, with AUC 0.842, sensitivity to predict the mortality 96.43% and specificity 59.38%, ( P<0.000 1). The percentage of PD-1 +/CD4 +T cell was 4.65%, with AUC 0.847, sensitivity 96.43%, specificity 62.50%,( P<0.000 1). The percentage of PD-1 +/CD8 +T cell was 3.91%, with AUC 0.771, sensitivity 64.29%, specificity 81.25%,( P=0.000 3). Conclusions:The T cell PD-1 expression is an independent risk factor to predict the 28-day mortality in septic patients. Combining the proportions of PD-1 +/CD3 +, PD-1 +/CD4 +and PD-1 +/CD8 +T cells may further enhance the predictive value for death.
6.Observation on the application of ventilator internal circuit disinfection in mechanically ventilated patients
Kai QIU ; Yongke ZHENG ; Nanyuan GU ; Longhuan ZENG ; Huixia ZHOU ; Guolong CAI
Chinese Critical Care Medicine 2019;31(4):449-452
Objective To understand the internal circuit contamination of ventilator in mechanical ventilation patients, to evaluate the effect of ventilator internal circuit disinfection and the impact on the incidence of ventilator-associated pneumonia (VAP). Methods A total of 39 patients with mechanical ventilation admitted to intensive care unit (ICU) of Hangzhou Geriatric Hospital from January 2017 to June 2018 were enrolled. Routine mechanical ventilation treatments for patients included pipeline replacement, aseptic operation, prevention of infection, etc. After 2 weeks of mechanical ventilation, the internal circuit of the ventilator was disinfected using the internal circuit sterilizer of the ventilator. Microorganism sampling and detection at 3 cm to the exhalation port of the internal circuit of the ventilator was performed before and after disinfection. The number of colonies was < 5 cfu/cm2 and no pathogenic bacteria could be detected. During the observation period, if the patient was complicated by VAP for anti-infective treatment, the ventilator with internal loop disinfection was replaced after infection control, and was incorporated again into the group for observation. The number of microbial colonies in the internal circuit of the ventilator before and after disinfection, the microbiological test pass rate and the incidences of VAP during the 2 weeks were observed. Results All 39 patients were included in the analysis, with 23 male and 16 female; with age of 65-97 years old, average (78.7±7.6) years old. Before the disinfection, 9 604 strains were detected in the internal circuit of the ventilator, including 8 687 strains of Gram-negative bacilli (90.4%), 902 strains of Gram-positive cocci (9.4%), and 15 strains of fungi (0.2%), which were detected in the lower respiratory tract of the patients. The strain concordance rate was 41%. The qualified rate of microbial detection in the internal circuit of the ventilator was 5.1%; 13 cases (33.3%) of VAP occurred during 2 weeks of mechanical ventilation. After disinfection, 785 strains of pathogens were detected in the internal circuit of the ventilator, and the number of colonies was significantly reduced compared with that before disinfection [cfu/cm2: 0 (0, 20) vs. 150 (15, 500), P < 0.01], of which 688 strains of Gram-negative bacilli (87.7%), 92 strains of Gram-positive cocci (11.7%) and 5 strains of fungi (0.6%) were found; the qualified rate of microbial detection in the internal circuit of ventilator reached 71.8%, which was significantly higher than that before disinfection (P < 0.01); 2 weeks after mechanical ventilation the incidence of VAP decreased slightly during the period [20.5% (8/39) vs. 33.3% (13/39)], but there was no significant difference (P > 0.05). Conclusions The internal circuit of the ventilator can be used to detect the pathogen and the sputum culture of the patients on mechanical ventilation with a high consistency. The disinfection of the pathogen could significantly reduce the air pollution of the ventilator and reduce the occurrence of VAP in the patients.
7.Analysis of NF1 gene mutations in two sporadic patients with neurofibromatosis type 1.
Xiaoyan ZHAO ; Qian ZHOU ; Liangqi CAI ; Zijun ZHAO ; Linglin ZHANG ; Peiru WANG ; Guolong ZHANG
Chinese Journal of Medical Genetics 2018;35(4):489-492
OBJECTIVETo detect mutations of the NF1 gene in two sporadic cases with neurofibromatosis type 1 (NF1) and explore their molecular mechanisms.
METHODSClinical data of the two patients was collected. Genomic DNA was extracted from peripheral blood samples. Specific primers were designed to exclude pseudogenes. PCR was performed to amplify all coding exons of the NF1 gene. PCR products were directly sequenced.
RESULTSTwo novel mutations of the NF1 gene (c.1019-1020delCT in exon 9 and c.7189G to A in exon 48) were respectively identified in the two patients but not among their unaffected parents or 100 healthy controls.
CONCLUSIONMutations of the NF1 gene may have predisposed to the NF1 in the two patients.
8.Analysis of KIT mutations in five patients from two Han Chinese pedigrees affected with Piebaldism.
Yongxian LAI ; Zijun ZHAO ; Qian ZHOU ; Lude ZHU ; Linglin ZHANG ; Guolong ZHANG ; Yicheng TANG ; Xiuli WANG
Chinese Journal of Medical Genetics 2018;35(3):366-370
OBJECTIVETo screen for KIT gene mutations in two Han Chinese pedigrees affected with Piebaldism.
METHODSClinical data of the pedigrees was collected. Genomic DNA was extracted from blood samples collected from the pedigrees and 120 unrelated healthy controls. All coding exons of the KIT gene were subjected to PCR amplification and direct sequencing.
RESULTSTwo missense mutations, c.1861G>A(p.Ala621Thr) and c.1872G>A(p.Met624Ile), were identified respectively in the two pedigrees. Neither mutation was found among healthy members from the respective pedigree and the 120 unrelated healthy controls. c.1872G>A is a novel mutation.
CONCLUSIONMutations of the KIT gene may affect the structure and function of the transmembrane receptor KIT, which lead to the disease.
9.Analysis of clinical and genetic features of nine patients with disseminated superfacial actinic porokeratosis.
Xiuling LI ; Qian ZHOU ; Lude ZHU ; Zijun ZHAO ; Peiru WANG ; Linglin ZHANG ; Guolong ZHANG ; Xiuli WANG
Chinese Journal of Medical Genetics 2017;34(4):481-485
OBJECTIVETo analyze the clinical and genetic features of 9 ethnic Han Chinese patients with disseminated superfacial actinic porokeratosis (DSAP).
METHODSGenomic DNA was extracted from peripheral blood samples collected from the patients. PCR and direct sequencing were carried out for five patients from a family, 4 sporadic cases, and 120 healthy controls to identify potential mutations of four genes (MVK, MVD, PMVK, FDPS) involved in the mevalonate pathway as well as SLC17A9, SSH1, and SART3 genes. Pathogenecity of suspected mutations were assessed with SIFT, and Polyphen-2 scores.
RESULTSA c.746T>C mutation was identified in the family and two sporadic cases, while a c.875A>G mutation was identified in another sporadic case. No mutation was identified in the remainder genes among all patients. Scoring has suggested that the c.746T>C and c.875A>G mutations of the MVD gene are probably pathogenic.
CONCLUSIONc.746 T>C and c.875A>G of the MVD gene are most common mutations. Skin rashes of the patients have a strong connection with the sunlight, albeit a significant difference among patients was discovered.
Aged, 80 and over ; Case-Control Studies ; Female ; Humans ; Male ; Middle Aged ; Mutation ; genetics ; Pedigree ; Porokeratosis ; genetics
10.Expression and significance of osteogenic genes on porous tantalum-bone interface during osteogenesis
Zhenquan LAI ; Yishuang CUI ; Chao CHEN ; Guolong ZHOU ; Xiangyu PAN ; Qian WANG ; Hongquan GAN ; Zhiqiang WANG ; Qijia LI
Chinese Journal of Tissue Engineering Research 2017;21(18):2789-2795
BACKGROUND:Previous studies have shown that home-made porous tantalum has non-toxicity and good biocompatibility, and can promote osteogenesis. Herein, we explore the mechanisms of tantalum-bone interface osseointegration.OBJECTIVE:To observe the morphological characteristics and expressions of integrin β1 and fibronectin on the interface between porous tantalum and bone tissues after implantation into the right rabbit femur, and to evaluate the biological mechanisms of tantalum-bone interface osseointegration.METHODS: Animal models of bilateral femoral condyle defects were made in Japanese big ear rabbits. Porous tantalum rod and allogeneic bone were respectively implanted into the left (experimental group) and right (control group) femur of rabbits. The animal specimens at the bone defect region were taken and made into paraffin sections and hard tissue sections at postoperative 2, 4, 8 weeks for morphological observation of new bone at the junction between the tantalum rod and host bone under light microscope, for osteogenic observation of the tantalum-bone interface under scanning electron microscope, and for immunohistochemical detection of integrin β1 and fibronectin expression.RESULTS AND CONCLUSION:Porous tantalum was bonded closely with the host bone. The loose and thick fibrous capsule was observed in the early stage and became thinner in the late stage shown by hematoxylin-eosin staining. The new bone was visible on tantalum-bone interface. Hard tissue slicing observation showed that the new bone was seen on the porous tantalum-bone interface, blood capillaries grew into the pores at postoperative 2 weeks and the pores were full of new bone tissues at postoperative 4 and 8 weeks. Under the scanning electron microscope, the osteoblasts appeared on the tantalum surface and in the pores at the early stage, and bone maturation and lamelar bone were seen at the late stage. The immunohistochemical results showed that the expression of integrin β1 in the experimental group was significantly lower than that in the control group at postoperative 2 weeks (P < 0.05), but the expression of fibronectin had no significant difference between the two groups (P > 0.05). In addition, there was a decline trend in the expression of integrin β1 and fibronectin atpostoperative 2, 4, 8 weeks. To conclude, the porous tantalum material is beneficial to enhance adhesion of osteoblasts on the surface and inside the micro-pores. Increased expression of integrin β1 and fibronectin on the tantalum-bone interface at early stage may promote early osteogenesis, while their decreased expression at bone maturing stage can promote osseointegration and bone remodeling.

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