Objective:To investigate the effect and underlying mechanism of sonodynamic therapy (SDT) on inflammation-related atrial fibrillation (AF) susceptibility.Methods:Lipopolysaccharide (LPS)-stimulated mouse and HL-1 mouse atrial myocyte models were used. (1) In vivo study: experimental groups included control, LPS, LPS+SDT, and SDT groups, with 20 mice in each group. Atrial fibrillation inducibility and duration were assessed by electrical stimulation. Western blot was used to analyze atrial expression of NOD-like receptor family pyrin domain-containing protein 3 (NLRP3), interleukin (IL)-1β, and IL-18. Immunohistochemistry was used to detect calcium voltage-gated channel subunit alpha1 C (CACNA1C) expression. (2) In vitro study: cell counting kit-8 (CCK-8) and Western blot were used to determine the optimal and safe LPS concentration. The safe incubation condition for the sonosensitizer sinoporphyrin sodium was determined by CCK-8 and fluorometry. An LPS-induced inflammatory model in HL-1 atrial myocytes was used, with experimental groups including control, LPS, LPS+SDT, LPS+sinoporphyrin sodium, and LPS+ultrasound groups. NLRP3 was overexpressed using plasmid transfection, with experimental groups including control, NLRP3 plasmid, negative control plasmid, and NLRP3 plasmid+SDT groups. SDT was applied to LPS-stimulated or NLRP3-overexpressing HL-1 cells. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to measure mRNA and protein levels of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), Cleaved Caspase-1, IL-1β, IL-18, and CACNA1C. The NLRP3 inhibitor MCC950 was used to validate the relationship of NLRP3 and CACNA1C. The experimental groups included control, LPS, LPS+MCC950, and MCC950 groups. Intracellular reactive oxygen species (ROS) levels were detected using the probe DCFH-DA, and the ROS scavenger N-acetyl-L-cysteine (NAC) was used to test if the effects of SDT was ROS-dependent.Results:(1) In vivo: The LPS+SDT group exhibited a lower incidence of atrial fibrillation induction and a shorter duration of atrial fibrillation compared to the LPS group(both P<0.05). Protein expression levels of NLRP3 and IL-1β were lower than those in the LPS group (all P<0.05), while the expression of CACNA1C subunit tended to increase relative to the LPS group ( P>0.05). (2) In vitro: The safe concentration of LPS for administration was ≤20 μg/ml, with an optimal pro-inflammatory concentration of 4 μg/ml. The safe concentration of sinoporphyrin sodium for administration was 0.4 μmol/L, with an optimal incubation time of 4 hours. Compared to the LPS group or NLRP3 plasmid group, the LPS+SDT group or NLRP3 plasmid+SDT group exhibited lower expression levels of NLRP3, ASC, Cleaved Caspase-1, IL-1β, and IL-18, and higher mRNA and protein levels of CACNA1C (all P<0.05). The LPS+MCC950 group had higher CACNA1C protein expression than the LPS group ( P<0.05). SDT increased intracellular ROS levels, and NAC blocked the regulatory effects of SDT on NLRP3 and CACNA1C. Conclusion:SDT reduces atrial fibrillation susceptibility in mice by inhibiting NLRP3 inflammasome activation in atrial cardiomyocytes, thereby upregulating the L-type calcium channel subunit CACNA1C.

Objective:To investigate the effect and underlying mechanism of sonodynamic therapy (SDT) on inflammation-related atrial fibrillation (AF) susceptibility.Methods:Lipopolysaccharide (LPS)-stimulated mouse and HL-1 mouse atrial myocyte models were used. (1) In vivo study: experimental groups included control, LPS, LPS+SDT, and SDT groups, with 20 mice in each group. Atrial fibrillation inducibility and duration were assessed by electrical stimulation. Western blot was used to analyze atrial expression of NOD-like receptor family pyrin domain-containing protein 3 (NLRP3), interleukin (IL)-1β, and IL-18. Immunohistochemistry was used to detect calcium voltage-gated channel subunit alpha1 C (CACNA1C) expression. (2) In vitro study: cell counting kit-8 (CCK-8) and Western blot were used to determine the optimal and safe LPS concentration. The safe incubation condition for the sonosensitizer sinoporphyrin sodium was determined by CCK-8 and fluorometry. An LPS-induced inflammatory model in HL-1 atrial myocytes was used, with experimental groups including control, LPS, LPS+SDT, LPS+sinoporphyrin sodium, and LPS+ultrasound groups. NLRP3 was overexpressed using plasmid transfection, with experimental groups including control, NLRP3 plasmid, negative control plasmid, and NLRP3 plasmid+SDT groups. SDT was applied to LPS-stimulated or NLRP3-overexpressing HL-1 cells. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to measure mRNA and protein levels of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), Cleaved Caspase-1, IL-1β, IL-18, and CACNA1C. The NLRP3 inhibitor MCC950 was used to validate the relationship of NLRP3 and CACNA1C. The experimental groups included control, LPS, LPS+MCC950, and MCC950 groups. Intracellular reactive oxygen species (ROS) levels were detected using the probe DCFH-DA, and the ROS scavenger N-acetyl-L-cysteine (NAC) was used to test if the effects of SDT was ROS-dependent.Results:(1) In vivo: The LPS+SDT group exhibited a lower incidence of atrial fibrillation induction and a shorter duration of atrial fibrillation compared to the LPS group(both P<0.05). Protein expression levels of NLRP3 and IL-1β were lower than those in the LPS group (all P<0.05), while the expression of CACNA1C subunit tended to increase relative to the LPS group ( P>0.05). (2) In vitro: The safe concentration of LPS for administration was ≤20 μg/ml, with an optimal pro-inflammatory concentration of 4 μg/ml. The safe concentration of sinoporphyrin sodium for administration was 0.4 μmol/L, with an optimal incubation time of 4 hours. Compared to the LPS group or NLRP3 plasmid group, the LPS+SDT group or NLRP3 plasmid+SDT group exhibited lower expression levels of NLRP3, ASC, Cleaved Caspase-1, IL-1β, and IL-18, and higher mRNA and protein levels of CACNA1C (all P<0.05). The LPS+MCC950 group had higher CACNA1C protein expression than the LPS group ( P<0.05). SDT increased intracellular ROS levels, and NAC blocked the regulatory effects of SDT on NLRP3 and CACNA1C. Conclusion:SDT reduces atrial fibrillation susceptibility in mice by inhibiting NLRP3 inflammasome activation in atrial cardiomyocytes, thereby upregulating the L-type calcium channel subunit CACNA1C.

Objective The current study aims to investigate the protective effect and mechanisms of baicalin on pathological left ventricular remodeling.Methods Angiotensin Ⅱ(Ang Ⅱ)infusion mouse model was adopted to evaluate the impact of baicalin on pathological left ventricular remodeling in vivo.C57BL/6J mice were randomly allocated to 5 experimental groups,including sham controls,model group(Ang Ⅱ-infusion controls),as well as low-,medium-,and high-dose baicalin treatment groups.Except for the sham controls,C57/BL6 mice were subjected to AngⅡ infusion for 2 weeks.The mice from the baicalin treatment groups received baicalin via gavage at the indicated doses for 2 weeks.The blood pressure,body weight,heart weight and tibia length were measured at the end of the indicated treatments.Immunohistochemistry of wheat germ agglutinin(WGA)was performed to examine the cross-sectional area of cardiomyocytes.Immunohistochemistry was also performed to assess the expression of atrial natriuretic peptide(ANP)in cardiomyocytes.Hematoxylin/eosin(HE)staining and Masson's trichrome staining were performed to evaluate the cardiac pathologies.In vitro experiments were as follows.Ang Ⅱ was adopted to induce cardiomyocyte hypertrophy in H9C2 cells in order to determine if baicalin is able to directly suppress cardiomyocyte hypertrophy.H9C2 cells were divided into vehicle control group(VC group),model group(Ang Ⅱ group)and baicalin group(Bai group).The morphology and size of cardiomyocytes were examined by rhodamine phalloidin staining.The intracellular level of ANP was analyze by immunofluorescence staining.Mitochondrial superoxide(Mito-SOX)was assessed to evaluate oxidative stress.The mitochondrial membrane potential(ΔΨm)was analyzed by JC-1 staining.The opening of mitochondrial permeability transition pore(mPTP)was evaluated by calcein acetyl methyl ester(Calcein AM)staining.Results The in vivo findings:Baicalin significantly antagonized Ang Ⅱ-induced elevation of systolic blood pressure(P<0.05)when administered at the medium and high doses.Meanwhile,baicalin treatment resulted in lower ratios of heart weight to tibia length(HW/TL)and heart weight to body weight(HW/BW)in Ang Ⅱ-infused mice.Baicalin treatment mitigated cardiomyocyte hypertrophy(P<0.05)and lowered the level of cardiomyocyte ANP(P<0.05)in Ang Ⅱ-infused mice.Furthermore,baicalin treatment significantly alleviated cardiac inflammation and fibrosis in Ang Ⅱ-infused mice(P<0.05).In vitro findings:Baicalin suppressed Ang Ⅱ-stimulated enlargement of cardiomyocytes and elevation of the intracellular ANP in H9C2 cells.Moreover,baicalin alleviated Ang Ⅱ-induced mitochondrial oxidative stress,mitochondrial ΔΨm impairment and mPTP opening(P<0.05).Conclusion Our current findings demonstrate that baicalin is effective at mitigating Ang Ⅱ-mediated left ventricular pathological remodeling.Baicalin is pharmacologically active at antagonizing Ang Ⅱ-induced hypertrophic responses and mitochondrial dysfunction in cardiomyocytes,which may in part account for its therapeutic effects against pathological left ventricular remodeling.

Objective The current study aims to investigate the protective effect and mechanisms of baicalin on pathological left ventricular remodeling.Methods Angiotensin Ⅱ(Ang Ⅱ)infusion mouse model was adopted to evaluate the impact of baicalin on pathological left ventricular remodeling in vivo.C57BL/6J mice were randomly allocated to 5 experimental groups,including sham controls,model group(Ang Ⅱ-infusion controls),as well as low-,medium-,and high-dose baicalin treatment groups.Except for the sham controls,C57/BL6 mice were subjected to AngⅡ infusion for 2 weeks.The mice from the baicalin treatment groups received baicalin via gavage at the indicated doses for 2 weeks.The blood pressure,body weight,heart weight and tibia length were measured at the end of the indicated treatments.Immunohistochemistry of wheat germ agglutinin(WGA)was performed to examine the cross-sectional area of cardiomyocytes.Immunohistochemistry was also performed to assess the expression of atrial natriuretic peptide(ANP)in cardiomyocytes.Hematoxylin/eosin(HE)staining and Masson's trichrome staining were performed to evaluate the cardiac pathologies.In vitro experiments were as follows.Ang Ⅱ was adopted to induce cardiomyocyte hypertrophy in H9C2 cells in order to determine if baicalin is able to directly suppress cardiomyocyte hypertrophy.H9C2 cells were divided into vehicle control group(VC group),model group(Ang Ⅱ group)and baicalin group(Bai group).The morphology and size of cardiomyocytes were examined by rhodamine phalloidin staining.The intracellular level of ANP was analyze by immunofluorescence staining.Mitochondrial superoxide(Mito-SOX)was assessed to evaluate oxidative stress.The mitochondrial membrane potential(ΔΨm)was analyzed by JC-1 staining.The opening of mitochondrial permeability transition pore(mPTP)was evaluated by calcein acetyl methyl ester(Calcein AM)staining.Results The in vivo findings:Baicalin significantly antagonized Ang Ⅱ-induced elevation of systolic blood pressure(P<0.05)when administered at the medium and high doses.Meanwhile,baicalin treatment resulted in lower ratios of heart weight to tibia length(HW/TL)and heart weight to body weight(HW/BW)in Ang Ⅱ-infused mice.Baicalin treatment mitigated cardiomyocyte hypertrophy(P<0.05)and lowered the level of cardiomyocyte ANP(P<0.05)in Ang Ⅱ-infused mice.Furthermore,baicalin treatment significantly alleviated cardiac inflammation and fibrosis in Ang Ⅱ-infused mice(P<0.05).In vitro findings:Baicalin suppressed Ang Ⅱ-stimulated enlargement of cardiomyocytes and elevation of the intracellular ANP in H9C2 cells.Moreover,baicalin alleviated Ang Ⅱ-induced mitochondrial oxidative stress,mitochondrial ΔΨm impairment and mPTP opening(P<0.05).Conclusion Our current findings demonstrate that baicalin is effective at mitigating Ang Ⅱ-mediated left ventricular pathological remodeling.Baicalin is pharmacologically active at antagonizing Ang Ⅱ-induced hypertrophic responses and mitochondrial dysfunction in cardiomyocytes,which may in part account for its therapeutic effects against pathological left ventricular remodeling.

Objective:To investigate the phylogenetic and antigenic characteristics of hemagglutinin (HA) gene of influenza B/Victoria lineage (BV) viruses in Beijing during the 2021-2022 influenza surveillance season, and to analyze whether the circulating BV viruses match the vaccine strain.Methods:Pharyngeal swab specimens from influenza like-illness (ILI) cases in the 2021-2022 influenza surveillance season were collected from surveillance network labs in Beijing and cultured in MDCK cells and chicken embryo to isolate BV viruses. Nucleic acids of the viruses were extracted, and the HA gene was amplified and sequenced. The nucleotide and amino acid sequence identity of the HA gene was analyzed using MEGA5.0 software. A phylogenetic tree of HA gene was constructed using the maximum likelihood method. The N-glycosylation sites in HA were predicted online. Three-dimensional structure of HA was constructed using SWISS-MODEL homologous modeling. Hemagglutination inhibition (HI) test was performed to analyze the antigenicity of BV viruses.Results:A total of 402 BV viruses were collected and 58 strains with full-length HA gene sequences were chosen for further analysis. Compared with the HA gene of this year′s vaccine strain (B/Washington/02/2019), there were 27 amino acid mutations, 11 of which were located in four different antigenic determinants. The phylogenetic analysis revealed that three subgroups of 1A.3, 1A.3a1, and 1A.3a2 co-circulated in Beijing with 54 strains (54/58, 93.10%) clustered to the Clade 1A.3a2, two strains (2/58, 3.45%) clustered to the Clade 1A.3a1, and two strains (2/58, 3.45%) in the same subgroup (Clade 1A.3) as the vaccine component BV strain in 2021-2022. Compared with the vaccine strain (B/Washington/02/2019), two BV strains had an additional N-glycosylation site at residue 197, while the other 56 strains showed no change in N-glycosylation sites. Antigenic analysis showed that 35 BV strains (35/58, 60.34%) were antigenically similar to the vaccine strain and 23 strains (23/58, 39.66%) were low-response strains.Conclusions:Three subgroups of BV viruses co-circulated in Beijing during the 2021-2022 influenza surveillance season. The predominant subgroup was Clade 1A.3a2 (93.10%), showing a certain genetic distance with the vaccine strain (B/Washington/02/2019). Nearly 40% (39.66%) of the viruses were low-response strains. This study indicated that continuous monitoring of the variations of influenza epidemic strains and timely providing laboratory basis for screening vaccine component strains were the basic technical guarantee for coping with influenza pandemic.

Objective:To understand the epidemic situation of Redondoviridae in Beijing and analyze its epidemiologic characteristics.Methods:Pharyngeal swab samples of healthy people and patients with acute respiratory infection in Beijing, including influenza like cases and severe acute respiratory infection (SARI) cases in hospitals were collected. Real time PCR was used to detect the nucleic acid of Redondoviridae. The positive samples were amplified and sequenced to analyze their species. The age and sex distribution of patients and species distribution of Redondoviridae were obtained through statistical analysis. Multiplex PCR was used to detect other common respiratory pathogens in the positive samples of Redondoviridae in influenza like cases and SARI cases, and the pathogenicity of Redondoviridae was analyzed.Results:The positive rates of Redondoviridae in healthy people and acute respiratory infection cases were 20.48% (189/923) and 11.23% (43/390), respectively, with a statistically significant difference ( P<0.05). The positive rate of male was higher than that of female in the healthy population, and the positive rate of the elderly group was higher than that of the adult group and the underage group, with a statistically significant difference ( P<0.05). The positive rate of male patients with acute respiratory tract infection was higher than that of female patients, but there was no significant difference. The proportion of Vientovirus in the positive samples of Redondoviridae was higher than that of Brisavirus, and the difference was statistically significant ( P<0.05). Among the throat swabs of respiratory tract infection cases, 43 were positive for Redondoviridae, of whom 24 were not detected for other pathogens. Conclusions:Redondoviridae widely exists in healthy people of all age groups in Beijing, and is also found in acute respiratory infection cases. The positive rate of Redondoviridae is different in different ages and genders. Both Vientovirus and Brisavirus were detected, and the proportion of Vientovirus was significantly higher than Brisavirus.

Objective:To characterize the epidemic of influenza in Beijing from 2022 to 2023 and the variation of gene and antigenicity of hemagglutinin (HA) of influenza A H3N2 virus, so as to provide scientific basis for influenza prevention and control in Beijing.Methods:Statistical analysis was carried out on the result of influenza pathogenic monitoring in Beijing from week 14, 2022 to week 20, 2023, and 79 strains of influenza A H3N2 virus were selected at different time and population sources, and their genetic variation and evolution characteristics were analyzed through HA gene amplification sequencing and antigenicity analysis.Results:From week 14, 2022 to week 20, 2023, 24 244 throat swabs of influenza like cases were collected in Beijing, and 4 987 influenza virus nucleic acid positive cases were detected, including 2 749 influenza A H3N2 positive cases, with a detection rate of 11.34%. Among the 79 strains, 50 strains (63.29%) showed low response, 94.44% of the strains from August to November 2022 had low response, and 54.10% of the strains from February to March 2023 had low response, with a statistically significant difference ( χ2=8.079, P=0.004). Compared with the vaccine strain A/Darwin/9/2021, the HA gene sequence of 79 strains of influenza A H3N2 showed nucleotide similarity of 97.47% to 98.47% and amino acid similarity of 97.05% to 98.17%. Genetic evolution analysis showed that the 18 strains isolated from August to November 2022 were all distributed in the 3C.2a1b.2a.1a.1 branch, while the 61 strains isolated from February to March 2023 all belonged to the 3C.2a1b.2a.3a.1 branch. Compared with the vaccine strain, there were multiple site mutations distributed at multiple antigenic determinants and receptor binding sites in A, B, C, D, and E. All strains had potential glycosylation sites of 8NST, 22NGT, 38NAT, 45NSS, 63NCT, 126NWT, 133NGT, 246NST, 285NGS, 483NET, while one strain missed 165NVT glycosylation sites; 55 strains between February and March 2023 missed 122NES glycosylation sites. Conclusions:The HA gene locus of influenza A H3N2 virus detected in Beijing from week 14, 2022 to week 20, 2023 showed multiple mutations, continuous monitoring of this subtype variation is crucial.

Objective:To clarify the M protein ( emm gene) types and drug susceptibility characteristic variations of Group A Streptococcus (GAS) in children in Beijing. Methods:The GAS strains isolated from throat swab samples of children diagnosed with scarlet fever and pharyngeal infection in scarlet fever etiology surveillance sentinel hospitals in 16 districts of Beijing in 2018, 2019 and 2021 were analyzed retrospectively.PCR amplification and sequencing were used for emm genotyping, and the minimum inhibitory concentrations (MIC) of 10 antibiotics were determined by the broth microdilution method.The data were analyzed using χ2 test and Fisher′ s exact method between groups. Results:A total of 557 GAS strains were collected, and 11 emm genotypes ( emm1, emm3, emm4, emm6, emm11, emm12, emm22, emm75, emm89, emm128, and emm212) were detected.Of 557 strains, 238 trains were of emm1 type (42.73%), 271 strains were of emm12 type (48.65%) and 48 strains were of other emm types (8.62%). The detection rates of emm1, emm12 and other emm type genes in 2018, 2019, and 2021 were [37.50% (105/280 strains), 57.14% (160/280 strains), 5.36% (15/280 strains)], [49.05% (129/263 strains), 39.54% (104/263 strains), 11.41% (30/263 strains)], and [28.57% (4/14 strains), 50.00% (7/14 strains), 21.43% (3/14 strains)], respectively.In children infected with emm12 in 2018 and 2019, there were more children under 6 years old than children over 6 years old (62.50% vs.46.88%, 46.36% vs.30.36%) (χ 2=7.182, 6.973; all P<0.05). Drug susceptibility testing results suggested that 225 randomly selected GAS strains were all 100.00% sensitive to 7 antibiotics including Penicillin, Levofloxacin, Meropenem, Linezolid, Cefotaxime, Cefepime and Vancomycin.The rates of resistance to Erythromycin, Tetracycline and Clindamycin were [88.57% (93/105 strains), 87.62% (92/105 strains), 86.67% (91/105 strains)], and [94.34% (100/106 strains), 94.34% (100/106 strains), 87.74% (93/106 strains)] in 2018 and 2019, respectively.The test strains were 100.00% (14/14 strains) resistant to the above 3 antibiotics in 2021.MIC 50 and MIC 90 values of Penicillin in 2018, 2019, and 2021 were (0.03 mg/L, 0.03 mg/L), (0.03 mg/L, 0.06 mg/L), and (0.06 mg/L, 0.06 mg/L), respectively.Among 225 GAS strains, 207 strains had drug resistance and were resistant to more than one drug.Specifically, 94.69% (196/207 strains) were resistant to Erythromycin, Tetracycline and Clindamycin.About 4.35% (9/207 strains) were resistant to both Erythromycin and Clindamycin.A total of 0.97% (2/207 strains) were resistant to Erythromycin and Tetracycline. Conclusions:The emm genotypes of GAS in children in Beijing are diverse in 2018, 2019 and 2021.The dominant genotypes are emm12 and emm1, and emm12 is the main epidemiological type.GAS strains maintain highly resistant to Erythromycin, Clindamycin and Tetracycline, and sensitive to Penicillin and other antibiotics.However, MIC 50 and MIC 90 of Penicillin shows an ascending trend.

Objective:This study is to investigate the predictive value of serum levels of TIMP-2 and insulin-like growth factor-binding protein 7(IGFBP7) in patients with DCD(donation after cardiac death) kidney transplantation.Methods:A prospective research design was used to select DCD kidney transplant patients admitted to the Li Huili Hospital of Ningbo University from January 2018 to October 2020.Inclusion criteria: ①Complete data; ②There were no serious complications affecting the function of the transplanted kidney in the early postoperative period.Exclusion criteria: ①Incomplete data; ②Patients were unable or unwilling to cooperate with the study; ③Severe complications affecting the function of the transplanted kidney occurred early after the operation.The ELASE method was used to quantitatively detect the serum TIMP-2 and IGFBP7 levels at 6, 12, 24, 48, 72 hours and 7 days after renal transplantation, and monitor the serum creatinine values during the same period and 21 days after the operation. According to the occurrence of DGF, the measured values of TIMP-2 and IGFBP7 at different time points and their product's ability to predict the occurrence of DGF after kidney transplantation were analyzed. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to evaluate the diagnostic efficacy of TIMP-2 and IGFBP7 for DGF.Results:A total of 33 patients were enrolled, 7 patients (21.2%) in the DGF group and 26 patients (78.8%) in the non-DGF group. Between the two groups, the donor glomerular filtration rate were [98.5(15.8-132.5)ml/(min·1.73m 2) and 79.1(60.6-102.5)ml/(min·1.73m 2)], recipient gender (male/female: 3/4 cases and 10/16 cases), recipient age [48(34-56) Years old and 45(23-61) years old], the recipient's preoperative creatinine [1114.0(731.4-1293.0)μmol/L and 858.4(657.6-1051.9)μmol/L], the recipient's preoperative urea nitrogen [15.0(13.2-19.6)mmol/L and 17.3(13.6-20.9)mmol/L], receptor preoperative albumin [43.5(38.5-45.3)mmol/L and 41.2(37.5-46.1) mmol/L], recipient dialysis method [hemodialysis/peritoneal dialysis: 3/4 cases and 9/17 cases], warm ischemia time [6(5-7) and 5(4-6) min, there was no statistically significant difference] ( P>0.05). The values of serum IGFBP7 and TIMP-2×IGFBP7 in the DGF group were higher than those in the non-DGF group at all time points ( F=15.753, P=0.040; F=13.000, P=0.024), while serum TIMP-2 was not significant between the two groups difference ( F=1.157, P=0.075). For the diagnostic value of DGF, the AUC of serum IGFBP7 at 48 h after surgery was 0.863 (95% CI 0.696-1.000, P=0.004). When 5.97 ng/ml was used as the cut-off value, the sensitivity was 85.7% and the specificity was 80.8 %. The AUC of TIMP-2×IGFBP7 at 48 hours after surgery was 0.819 (95% CI 0.641-0.996, P=0.011). When 62.06(ng/ml) 2 was used as the cutoff value, the sensitivity was 71.4% and the specificity was 80.8%.There was no statistical difference in the area under the curve between the two ( P>0.05). There were differences in the dynamic trend of serum IGFBP7 and creatinine in the DGF group. Serum IGFBP7 at 7 days after surgery was positively correlated with creatinine at 21 days after surgery. Conclusion:Serum IGFBP7 and TIMP-2×IGFBP7 could predict the occurrence of DGF after DCD donor kidney surgery. The predictive value changes with time. Among them, 48h and 7d after surgery are the most valuable. However, serum TIMP-2 has not been found to have predictive value in this study.

Objective:To explore the predictive values of tissue inhibitor of metalloproteinase-2 (TIMP-2) and insulin-like growth factor binding protein 7 (IGFBP7) in donor sera and lavage fluid on delayed graft function (DGF) in donation after circulatory death (DCD) kidney transplant recipients.Methods:A total of 33 eligible kidney donors and 33 corresponding recipients were recruited. Preoperative serum and renal perfusion fluid samples of donors were collected to determine the levels of TIMP-2 and IGFBP7. Patients were grouped according to whether DGF occurred after kidney transplantation and measured indicators analyzed. Independent sample t test was utilized for comparing the groups with normal distribution measurement data. And χ2 test was employed for comparing the groups with normal distribution counting data and Mann-Whitney test for comparing the groups with non-normal distribution measurement data. Receiver operating characteristic (ROC) curve and area under curve (AUC) were used for evaluating the diagnostic efficacy of indicators. Results:In donor-DGF group, lavage fluid TIMP-2, product of lavage fluid TIMP-2 and IGFBP7 (TIMP-2×IGFBP7), serum IGFBP7 and product of serum TIMP-2 and IGFBP7 (TIMP-2×IGFBP7) were higher than those in donor-non-DGF group ( P<0.05). The AUC of TIMP-2, TIMP-2×IGFBP7, serum IGFBP7 and serum TIMP-2×IGFBP7 in the diagnosis of DGF were 0.753 (95%CI 0.546~0.959), 0.747 (95%CI 0.510~0.984), 0.824 (95%CI 0.615~1.000) and 0.852 (95%CI 0.660~1.000) respectively. Conclusions:Donor serum IGFBP7, donor serum TIMP-2×IGFBP7, lavage fluid TIMP-2 and lavage fluid TIMP-2×IGFBP7 may be used for predicting the occurrence of early DGF after kidney transplantation. Among them, serum TIMP-2×IGFBP7 has the highest diagnostic efficiency and may be an excellent predictor of DGF occurrence.