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Objective:To investigate the distribution of pathogenic bacteria of bloodstream infection after chemotherapy in patients with acute leukemia (AL), to analyze the risk factors for the occurrence of adverse events and to construct a nomogram model to predict the occurrence of adverse events.Methods:The clinical data of 313 AL patients with bloodstream infection who were admitted to the First Hospital of Jilin University from January 2018 to December 2020 were retrospectively analyzed, and the incidence, fatality and distribution characteristics of pathogenic bacteria after chemotherapy in AL patients were analyzed; the occurrence of adverse events (death or infectious shock) in patients with different clinicopathological characteristics were compared. Unconditional logistic binary regression model multifactor analysis was used to screen independent risk factors for the occurrence of adverse events in AL patients with bloodstream infection after chemotherapy; the nomogram model for predicting the occurrence of adverse events was developed by using R software; the Hosmer-Lemeshow test was used to verify the predictive effect of the model.Results:Of the 313 AL patients, the overall fatality rate was 4.2% (13/313), the all-cause fatality rate of bloodstream infection was 3.5% (11/313). Of the 313 cases, 254 cases (81.1%) were Gram-negative bacteria infection, mainly including 115 cases (45.3%) of Escherichia coli, 80 cases (31.5%) of Klebsiella pneumoniae, and 29 cases (11.4%) of Pseudomonas aeruginosa, and 10 cases (3.9%) died; 51 cases (16.3%) were Gram-positive cocci infection, mainly including 22 cases (43.1%) of Streptococcus spp., 20 cases (39.2%) of Staphylococcus spp., 7 cases (13.7%) of Enterococcus faecalis, and 0 case died; 8 cases (2.6%) were fungal infection, including 4 cases (1.3%) of Candida tropicalis, 2 cases (0.6%) of Candida subsmoothis, 1 case (0.3%) of Candida smooth, 1 case (0.3%) of new Cryptococcus, and 3 cases (37.5%) died. The differences in the occurrence rates of adverse events were statistically significant when comparing different treatment stage, risk stratification, timing of sensitive antibiotic use, total duration of fever, and glucocorticoid use in chemotherapy regimen, infecting bacteria carbapenem resistance, and leukemia remission (all P < 0.05). The results of logistic binary regression analysis showed that the use of glucocorticoid in chemotherapy regimen, the total duration of fever ≥7 d, the timing of sensitive antibiotic use ≥24 h, and carbapenem resistance of the infecting bacteria were independent risk factors for the occurrence of adverse events in AL patients with bloodstream infection after chemotherapy (all P < 0.05). A nomogram prediction model for the occurrence of adverse events in AL patients with bloodstream infection was established, and the nomogram model was calibrated and validated with good calibration and discrimination. Conclusions:The pathogenic bacteria of bloodstream infection after chemotherapy in AL patients is mainly Gram-negative bacteria, and the presence of glucocorticoid in chemotherapy regimen, long total duration of fever, poor timing of sensitive antibiotics, and infecting bacteria carbapenem resistance are risk factors for the occurrence of adverse events in AL patients with bloodstream infection after chemotherapy, and the nomogram prediction model based on these factors has a reliable predictive ability for the occurrence of adverse events.
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BACKGROUND: Trabecular metal has been reported to provide enough physiologic support for new bone formation, to induce bone ingrowth and osseointegration so as to achieve the biological synosteosis; therefore, it is available for improving the initial and second stability of the dental implant.OBJECTIVE: To explore the stress distributional differences between porous tantalum trabecular metal (PTTM) dental implant and conventional titanium (TI) dental implant in the zone of mandibular premolar using three-dimensional finite element analysis.METHODS: Three-dimensional finite element models emulating PTTM and TI dental implants were established using Mimics16.0 and CATIA in the zone of mandibular premolar with three types of bone (II, III, IV). Then 100 N force was applied on the abutment at a 45° angle to the vertical axis of the implants in software of MSC Patran2010 and Nastran2010, then the representative von Mises stress nodes were calculated and sampled randomly, and finally the von Mises stress distributional differences between two types of implants were analyzed using SPSS 20.0 statistical software.RESULTS AND CONCLUSION: (1) The Von Mises stresses around the two types of implants both focused on the interface of the cortical bone-abutment-implant region, and the stress was relatively less for the corresponding trabecular bone. (2) If the bone quality was similar, the average von Mises stress of PTTM was higher than that of TI dental implants, but there was no significant difference (P > 0.05). As the bone density lowered (II-IV), the average Von Mises stresses were both increased, and the increasing rate of PTTM was higher than that of TI in bone of II-III, and was lower than that of TI in bone of III-IV. In this experiment, there were no significant stress distributional differences between PTTM and TI dental implant. However, with the bone density reduction, the increasing rate of average Von Mises stress for PTTM was lowered than that for TI dental implants in bone of III-IV, which suggests that PTTM dental implant may be more beneficial for the primary and secondary stability in osteoporosis patients undergoing dental implantation.
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Objective To screen the active components of Bushen Huoxue Decoction ( BSHXD) involved in promoting the proliferation of bone marrow mesenchymal stem cells ( MSCs). Methods BSHXD and its subdivisions were extracted with petroleum ether, ethyl acetate, water-free ethanol and water respectively. MSCs were isolated and cultured by the bone marrow adherent method. At the third passage, MSCs were identified by the specific surface markers with immunofluorescence, and their osteogenic and adipogenic differentiation were tested by alizarin red staining and oil red “O” staining. After treated with the extracts of BSHXD and its subdivisions at gradient concentrations for 24 hours, cell viability was detected by methyl thiazolyl tetrazolium (MTT) assay for the screening of active components and optimal concentration. MTT assay was used to describe the growth curve of MSCs treated with the most effective components, and cell cycle was analyzed by flow cytometry. Results Compared with the blank control group, the extracts of BSHXD and its subdivisions could protect MSCs from death to various degrees. Of all the extracts, the ethyl acetate extract of Bushen Division ( BSD) , ethyl acetate extract of BSHXD, ethyl acetate extract of Huoxue Division ( HXD) had the strongest effect, and the effect was dose-dependent, 100 μg/mL being the optimal active concentration while having no any cytotoxic reaction. The results of MTT assay revealed that BSD extracts promoted the proliferation of MSCs significantly and was the most effective component, and then came BSHXD. The results of flow cytometry indicated that BSD extract had the most strongest effect on increasing the amount of MSCs at proliferative phase, and then came BSHXD. Conclusion BSD ethyl acetate extract is the active component of BSHXD for promoting the proliferation of MSCs, showing an effect on increasing the proportion of MSCs at proliferative phase.