ObjectiveTo investigate the effect of the nitroglycerin-controlled low central venous pressure （CLCVP） technique on brain metabolic markers and cerebral blood oxygen saturation in patients undergoing laparoscopic hepatectomy for liver cancer， and to reduce the risk of neurological complications. MethodsA total of 105 patients who underwent elective laparoscopic hepatectomy for liver cancer in Haikou Hospital Affiliated to Xiangya Hospital of Central South University from April 2020 to May 2023 were enrolled and randomly divided into CLCVP group with 54 patients and non-CLCVP group with 51 patients. The patients in the CLCVP group were treated with the nitroglycerin CLCVP technique during surgery， while those in the non-CLCVP group were given conventional surgical treatment. The two groups were compared in terms of the following indicators： perioperative indicators； hemodynamic parameters and cerebral oxygen metabolism before anesthesia induction （T0）， at 5 minutes after anesthesia induction （T1）， at 5 minutes after the beginning of liver parenchyma dissection （T2）， at 5 minutes after the end of hepatectomy （T3）， and immediately after the end of surgery （T4）； the changes in liver function parameters after surgery； the incidence rate of adverse reactions. The independent-samples t test was used for comparison of continuous data between two groups， and the chi-square test was used for comparison of categorical data between two groups； the analysis of variance with repeated measures was used for comparison between multiple time points. ResultsCompared with the non-CLCVP group， the CLCVP group had significantly lower intraoperative blood loss and intraoperative fluid infusion volume （t=5.408 and 7.220， both P<0.05）， while there were no significant differences between the two groups in time of operation， anesthesia time， extubation time， resuscitation time and intraoperative urine volume （all P>0.05）. Compared with the data at T0， both groups had significant reductions in mean arterial pressure， heart rate， and central venous pressure during surgery （all P<0.05）， and compared with the non-CLCVP group， the CLCVP group had significantly lower mean arterial pressure and central venous pressure （P<0.05） and a significantly higher heart rate （P<0.05） at T2 and T3. Compared with the data at T0， both groups had a significant reduction in Ca-jvDO₂ at T2‍ ‍—‍ ‍T4 time points （all P<0.05）， while there was no significant difference in Ca-jvDO₂ between the two groups at each time point （all P>0.05）. Compared with the data at T0， the CLCVP group had a significant reduction in rSO₂ at T2‍ ‍—‍ ‍T4 time points （all P<0.05）， and the CLCVP group had a significantly lower level of rSO₂ than the non-CLCVP group at T2‍ ‍—‍ ‍T3 time points （both P<0.05）； there were no significant changes in CERO₂ and Djv-aBL in either group at each time point （all P>0.05）. At 3 and 7 days after surgery， both groups had significant increases in the liver function parameters of aspartate aminotransferase （AST）， alanine aminotransferase （ALT）， and total bilirubin （TBil） （all P<0.05）， and the CLCVP group had significantly lower levels of AST and ALT than the non-CLCVP group （all P<0.05）； there was no significant difference in TBil between the two groups at each time point （all P>0.05）. There was no significant difference in the incidence rate of perioperative complications between the two groups （χ²=0.729， P=0.394）. ConclusionThe application of the nitroglycerin CLCVP technique in laparoscopic hepatectomy for liver cancer can reduce the amount of intraoperative blood loss in patients， but it is necessary to further enhance the monitoring of cerebral blood oxygen saturation during surgery， so as to reduce the risk of neurological complications as much as possible.

This study aims to explore whether Naoxintong Capsules improve multiple cerebral infarctions and myocardial injury via promoting angiogenesis, thereby exerting a simultaneous treatment effect on both the brain and heart. Male SD rats were randomly divided into six groups: sham-operated group, model group, high-dose, medium-dose, and low-dose groups of Naoxintong Capsules(440, 220, and 110 mg·kg~(-1)), and nimodipine group(10.8 mg·kg~(-1)). Rat models of multiple cerebral infarctions were established by injecting autologous thrombus, and samples were collected and tested seven days after modeling. Evaluations included multiple cerebral infarction model assessments, neurological function scores, grip strength tests, and rotarod tests, so as to evaluate neuromotor functions. Morphological structures of brain and heart tissue were observed using hematoxylin-eosin(HE) staining, Nissl staining, and Masson staining. Network pharmacology was employed to screen the mechanisms of Naoxintong Capsules in improving multiple cerebral infarctions and myocardial injury. Neuronal and myocardial cell ultrastructures were observed using transmission electron microscopy. Apoptosis rate in brain neuronal cells was detected by TdT-mediated dUTP nick end labeling(TUNEL) staining, and reactive oxygen species(ROS) levels in myocardial cells were measured. Immunofluorescence was used to detect the expression of platelet endothelial cell adhesion molecule-1(CD31), antigen identified by monoclonal antibody Ki67(Ki67), hematopoietic progenitor cell antigen CD34(CD34), and hypoxia inducible factor-1α(HIF-1α) in brain and myocardial tissue. Western blot, and real-time quantitative polymerase chain reaction(RT-qPCR) were used to detect the expression of HIF-1α, vascular endothelial growth factor(VEGF), vascular endothelial growth factor receptor 2(VEGFR2), sarcoma(Src), basic fibroblast growth factor(bFGF), angiopoietin-1(Ang-1), and TEK receptor tyrosine kinase(Tie-2). Compared with the model group, the medium-dose group of Naoxintong Capsules showed significantly lower neurological function scores, increased grip strength, and prolonged time on the rotarod. Pathological damage in brain and heart tissue was reduced, with increased and more orderly arranged mitochondria in neurons and cardiomyocytes. Apoptosis in brain neuronal cells was decreased, and ROS levels in cardiomyocytes were reduced. The microvascular density and endothelial cells of new blood vessels in brain and heart tissue increased, with increased overlapping regions of CD31 and Ki67 expression. The relative protein and mRNA expression levels of HIF-1α, VEGF, VEGFR2, Src, Ang-1, Tie-2, and bFGF were elevated in brain tissue and myocardial tissue. Naoxintong Capsules may improve multiple cerebral infarctions and myocardial injury by mediating HIF-1α/VEGF expression to promote angiogenesis.
Animals ; Male ; Drugs, Chinese Herbal/administration & dosage* ; Rats, Sprague-Dawley ; Rats ; Cerebral Infarction/genetics* ; Hypoxia-Inducible Factor 1, alpha Subunit/genetics* ; Vascular Endothelial Growth Factor A/genetics* ; Capsules ; Signal Transduction/drug effects* ; Humans ; Brain/metabolism* ; Myocardium/metabolism* ; Apoptosis/drug effects*

This study aimed to characterize and identify the non-volatile components in aqueous and ethanolic extracts of the stems and leaves of Rhododendron tomentosum by using sensitive and efficient ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry(UHPLC-Q-TOF-MS) combined with a self-built information database. By comparing with reference compounds, analyzing fragment ion information, searching relevant literature, and using a self-built information database, 118 compounds were identified from the aqueous and ethanolic extracts of R. tomentosum, including 35 flavonoid glycosides, 15 phenolic glycosides, 12 flavonoids, 7 phenolic acids, 7 phenylethanol glycosides, 6 tannins, 6 phospholipids, 5 coumarins, 5 monoterpene glycosides, 6 triterpenes, 3 fatty acids, and 11 other types of compounds. Among them, 102 compounds were reported in R. tomentosum for the first time, and 36 compounds were identified by comparing them with reference compounds. The chemical components in the ethanolic and aqueous extracts of R. tomentosum leaves and stems showed slight differences, with 84 common chemical components accounting for 71.2% of the total 118 compounds. This study systematically characterized and identified the non-volatile chemical components in the ethanolic and aqueous extracts of R. tomentosum for the first time. The findings provide a reference for active ingredient research, quality control, and product development of R. tomentosum.
Rhododendron/chemistry* ; Chromatography, High Pressure Liquid/methods* ; Drugs, Chinese Herbal/chemistry* ; Mass Spectrometry/methods* ; Plant Leaves/chemistry*

PURPOSE: Hand-sewn anastomosis as the gold standard of vascular anastomosis cannot fully meet the requirements of vascular anastomosis in speed and quality. Various vascular couplers have been developed to ameliorate this situation. Most of them are mainly used for venous anastomosis rather than arterial anastomosis. Although it is generally acknowledged that in almost all operations involving vascular reconstruction, it is the arteries that need to be anastomosed faster and more accurately and not the veins. A dedicated device is needed for creating arterial anastomosis in an easy, timesaving, less damaging but reliable procedure. Therefore, we plan to develop a novel arterial coupler device and test pre-clinical safety and effectiveness. METHODS: In this cohort study, the rationality of this novel arterial coupler was preliminarily tested by finite element analysis before it was manufactured. Several factors restrict the use of vascular couplers in arterial anastomosis, such as arterial eversion, fixation, etc. The manufactured arterial couplers underwent in vitro and in vivo experiments. In vitro, isolated arteries of beagles were anastomosed with the assistance of an arterial coupler, and the anastomosed arteries were evaluated through anti-traction tests. In animal experiments, the bilateral femoral arteries of 5 beagles served as a control group. After dissection, the femoral artery on one side was randomly selected to be anastomosed with a quick arterial coupler (QAC) (QAC group), and the femoral artery on the other side was anastomosed by the same person using an end-to-end suture technique with a 6-0 Prolene suture (suture group). The bilateral femoral arteries of 5 beagles were used for coupler-assisted anastomosis and hand-sewn anastomosis in vivo, respectively. Success rate, blood loss, anastomotic time, clamp time, total operation time, and patency rate were recorded. The patency of anastomosed arteries was assessed using vascular Doppler ultrasound, electromagnetic flowmeter, and pathological examination (6 weeks after surgery). RESULTS: As a novel arterial coupler, QAC was successfully designed and manufactured by using poly lactic-co-glycolic acid raw materials and 3-dimensions printing technology. Its rationality was preliminarily tested through finite element analysis and related mechanical analysis methods. The isolated arteries were successfully anastomosed with the assistance of QAC in vitro testing, which showed good anti-traction properties. In animal studies, QAC-assisted arterial anastomosis has superior profiles compared to hand-sewn anastomosis in anastomotic time (7.80 ± 1.41 vs. 16.38 ± 1.04 min), clamp time (8.80 ± 1.41 vs. 14.14 ± 1.57 min), and total operation time (46.64 ± 2.38 vs. 51.96 ± 3.65 min). The results of electromagnetic flowmeter, vascular Doppler ultrasound, and pathological examination showed that QAC-assisted anastomotic arteries were superior to hand-sewn arteries in terms of postoperative blood flow (16.86 ± 3.93 vs. 10.36 ± 0.92 mL/min) and vascular patency in 6 weeks after surgery. CONCLUSION QAC is a well-designed and easily maneuverable device specialized for end-to-end arterial anastomosis. Application of this device may decrease thermal ischemia time and improve the patency of anastomotic arteries, thus, improving outcomes.
Animals ; Anastomosis, Surgical/instrumentation* ; Dogs ; Femoral Artery/surgery* ; Vascular Surgical Procedures/instrumentation* ; Finite Element Analysis

PURPOSE: The rate of complications among patients undergoing surgery has increased due to infection with SARS-CoV-2 and other variants of concern. However, Omicron has shown decreased pathogenicity, raising questions about the risk of postoperative complications among patients who are infected with this variant. This study aimed to investigate complications and related factors among patients with recent Omicron infection prior to undergoing orthopedic surgery. METHODS: A historical control study was conducted. Data were collected from all patients who underwent surgery during 2 distinct periods: (1) between Dec 12, 2022 and Jan 31, 2023 (COVID-19 positive group), (2) between Dec 12, 2021 and Jan 31, 2022 (COVID-19 negative control group). The patients were at least 18 years old. Patients who received conservative treatment after admission or had high-risk diseases or special circumstances (use of anticoagulants before surgery) were excluded from the study. The study outcomes were the total complication rate and related factors. Binary logistic regression analysis was used to identify related factors, and odds ratio (OR) and 95% confidence interval (CI) were calculated to assess the impact of COVID-19 infection on complications. RESULTS: In the analysis, a total of 847 patients who underwent surgery were included, with 275 of these patients testing positive for COVID-19 and 572 testing negative. The COVID-19-positive group had a significantly higher rate of total complications (11.27%) than the control group (4.90%, p < 0.001). After adjusting for relevant factors, the OR was 3.08 (95% CI: 1.45-6.53). Patients who were diagnosed with COVID-19 at 3-4 weeks (OR = 0.20 (95% CI: 0.06-0.59), p = 0.005), 5-6 weeks (OR = 0.16 (95% CI: 0.04-0.59), p = 0.010), or ≥7 weeks (OR = 0.26 (95% CI: 0.06-1.02), p = 0.069) prior to surgery had a lower risk of complications than those who were diagnosed at 0-2 weeks prior to surgery. Seven factors (age, indications for surgery, time of operation, time of COVID-19 diagnosis prior to surgery, C-reactive protein levels, alanine transaminase levels, and aspartate aminotransferase levels) were found to be associated with complications; thus, these factors were used to create a nomogram. CONCLUSION Omicron continues to be a significant factor in the incidence of postoperative complications among patients undergoing orthopedic surgery. By identifying the factors associated with these complications, we can determine the optimal surgical timing, provide more accurate prognostic information, and offer appropriate consultation for orthopedic surgery patients who have been infected with Omicron.
Humans ; COVID-19/complications* ; Male ; Female ; Middle Aged ; Postoperative Complications/epidemiology* ; SARS-CoV-2 ; Orthopedic Procedures/adverse effects* ; Aged ; Nomograms ; Adult ; Retrospective Studies ; Risk Factors

OBJECTIVES: To construct a Z-score regression model for coronary artery diameter based on echocardiographic data from children in Sichuan Province and to establish a Z-score calculation formula. METHODS: A total of 744 healthy children who underwent physical examinations at Sichuan Provincial People's Hospital from January 2020 to December 2022 were selected as the modeling group, while 251 children diagnosed with Kawasaki disease at the same hospital from January 2018 to December 2022 were selected as the validation group. Pearson correlation analysis was conducted to analyze the relationships between coronary artery diameter values and age, height, weight, and body surface area. A regression model was constructed using function transformation to identify the optimal regression model and establish the Z-score calculation formula, which was then validated. RESULTS: The Pearson correlation analysis showed that the correlation coefficients for the diameters of the left main coronary artery, left anterior descending artery, left circumflex artery, and right coronary artery with body surface area were 0.815, 0.793, 0.704, and 0.802, respectively (P<0.05). Among the constructed regression models, the power function regression model demonstrated the best performance and was therefore chosen as the optimal model for establishing the Z-score calculation formula. Based on this Z-score calculation formula, the detection rate of coronary artery lesions was found to be 21.5% (54/251), which was higher than the detection rate based on absolute values of coronary artery diameter. Notably, in the left anterior descending and left circumflex arteries, the detection rate of coronary artery lesions using this Z-score calculation formula was higher than that of previous classic Z-score calculation formulas. CONCLUSIONS The Z-score calculation formula established based on the power function regression model has a higher detection rate for coronary artery lesions, providing a strong reference for clinicians, particularly in assessing coronary artery lesions in children with Kawasaki disease.
Humans ; Male ; Female ; Child, Preschool ; Child ; Coronary Artery Disease/diagnostic imaging* ; Infant ; Mucocutaneous Lymph Node Syndrome ; Regression Analysis ; Coronary Vessels/diagnostic imaging* ; Echocardiography ; Adolescent

OBJECTIVE: To establish an in vitro cell model simulating acute graft-versus-host disease (aGVHD) bone marrow microenvironment injury with the advantage of mouse serum of aGVHD model and explore the effect of serum of aGVHD mouse on the adipogenic differentiation ability of mesenchymal stem cells (MSCs). METHODS: The 6-8-week-old C57BL/6N female mice and BALB/c female mice were used as the donor and recipient mice of the aGVHD model, respectively. Bone marrow transplantation (BMT) mouse model (n=20) was established by being injected with bone marrow cells (1×10⁷ per mouse) from donor mice within 4-6 hours after receiving a lethal dose (8.0 Gy, 72.76 cGy/min) of γ ray general irradiation. A mouse model of aGVHD (n=20) was established by infusing a total of 0.4 ml of a mixture of donor mouse-derived bone marrow cells (1×10⁷ per mouse) and spleen lymphocytes (2×10⁶ per mouse). The blood was removed from the eyeballs and the mouse serum was aspirated on the 7^th day after modeling. Bone marrow-derived MSCs were isolated from 1-week-old C57BL/6N male mice and incubated with 2%, 5% and 10% BMT mouse serum and aGVHD mouse serum in the medium, respectively. The effect of serum in the two groups on the in vitro adipogenic differentiation ability of mouse MSCs was detected by Oil Red O staining. The expression levels of related proteins PPARγ and CEBPα were detected by Western blot. The expression differences of key adipogenic transcription factors including PPARγ, CEBPα, FABP4 and LPL were determined by real-time quantitative PCR (RT-qPCR). RESULTS: An in vitro cell model simulating the damage of bone marrow microenvironment in mice with aGVHD was successfully established. Oil Red O staining showed that the number of orange-red fatty droplets was significantly reduced and the adipogenic differentiation ability of MSC was impaired at aGVHD serum concentration of 10% compared with BMT serum. Western blot experiments showed that adipogenesis-related proteins PPARγ and CEBPα expressed in MSCs were down-regulated. Further RT-qPCR assay showed that the production of PPARγ, CEBPα, FABP4 and LPL, the key transcription factors for adipogenic differentiation of MSC, were significantly reduced. CONCLUSION The adipogenic differentiation capacity of MSCs is inhibited by aGVHD mouse serum.
Animals ; Mesenchymal Stem Cells/cytology* ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Adipogenesis ; Female ; Cell Differentiation ; Graft vs Host Disease/blood* ; Bone Marrow Cells/cytology* ; PPAR gamma/metabolism* ; Disease Models, Animal ; CCAAT-Enhancer-Binding Protein-alpha/metabolism*

Objective To observe the clinical efficacy and safety of Vitapex paste and calcium hydroxide paste in the treatment of root canal patients.Methods Patients who received root canal treatment were included,and the data of patients who received one-time injection of calcium hydroxide pastefor root canal filling treatment were used as the control group;the data of patients who received Vitapex paste and calcium hydroxide paste for one-time filling injection root canal treatment at the same time were included as treatment group.The clinical efficacy,degree of pain,diameter of apical foramen,apical closure time,and detection of interleukin(IL)-1β,IL-8 and tumor necrosis factor-α(TNF-α)in gingival crevicular fluid between two groups of patients after 6 months were compared.Results There were 40 cases in control group and 42 cases in treatment group.After treatment,the total effective rates of treatment group and control group were 97.62％(41 cases/42 cases)and 80.00％(32 cases/40 cases),with significant difference(P＜0.05).After 6 months of treatment,36 patients in treatment group had no pain or mild pain,6 patients had moderate pain,and 0 patient had severe pain;there were 21 patients in control group who had no pain or mild pain,13 patients in moderate pain,and 6 patients in severe pain.The pain level in treatment group was significantly improved compared with control group,and the pain was reduced(P＜0.05).After 6 months of treatment,the diameter of the apical foramen and the closure time of treatment group were(0.55±0.22)mm and(13.86±2.05)month,which in control group were(0.81±0.10)mm and(16.98±4.35)month,the results of treatment group were significantly better than those in control group(all P＜0.05).After 6 months of treatment,IL-1 β,IL-8,TNF-α in the gingival crevicular fluid of treatment group were(12.50±2.18),(25.33±6.29)and(2.12±0.32)μg·L-1,which in control group were(23.00±6.00),(36.88±10.14)and(4.08±0.57)μg·L-1,all with significant difference(all P＜0.05).The drug complications in treatment group were 2 cases of gingival swelling,1 case of gingival pain.The control group had 3 cases of gingival swelling,2 cases of gingival pain,1 case of occlusal discomfort,respectively,with no statistically significant difference(P＞0.05).Conclusion The composite application of Vitapex paste and calcium hydroxide paste is more effective in treating root canals than a single calcium silicate bioceramic.

Objective To compare the bioavailability and bioequivalence of pivastatin calcium dispersive tablets in healthy Chinese subjects.Methods A single dose of pitavastatin calcium(2 mg)was orally administered to the test preparation or reference preparation under fasting and postprandial conditions,respectively.The plasma concentrations of pitavastatin calcium were measured at different time points before and after administration by high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).The bioequivalence of the two formulations was evaluated.Results Subjects received pitavastatin calcium test preparation and reference preparation in fasting condition,the Cmax were(47.79±23.99)and(46.03±21.82)ng·L-1;AUC0_,were(96.56±42.64)and(97.96±35.40)ng·h·L-1;AUC0_∞ were(102.09±43.01)and(103.46±35.62)ng·h·L-1,respectively.The 90％confidence intervals of the geometric mean ratios of Cmax,AUC0_t and AUC0-∞ of pitavastin-calcium test formulation and reference formulation were 96.28％-111.16％,94.46％-101.19％and 94.77％-101.31％,respectively.Subjects received pitavastatin calcium test preparation and reference preparation in fasting condition,the Cmax were(27.32±10.68)and(28.58±11.39)ng·L-1;AUC0_t were(82.76±27.58)and(84.06±29.12)ng·h·L-1;AUC0_∞ were(87.88±26.93)and(89.29±29.18)ng·h·L-1,respectively.The 90％confidence intervals of the geometric mean ratios of Cmax,AUC0_t and AUC0_∞ of the test formulation and the reference formulation of pitavastatin calcium were 87.39％-102.10％,94.62％-101.34％and 94.88％-101.47％,respectively.All of them were within the bioequivalence range of 80.00％to 125.00％.Conclusion Two pivastatin calcium dispersion tablets were bioequivalent and safe in healthy Chinese adult subjects.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.