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Objective:To investigate the pathogen distribution and antimicrobial resistance among lower respiratory tract infections in patients with hematological malignancies.Methods:Sputum samples were collected from 967 patients with hematological malignancies and lower respiratory tract infections in Department of Hematology,the Second Hospital of Shanxi Medical University from January 2017 to July 2020. The pathogens and drug sensitivity reports were carried out by automatic bacterial identification instruments. WHONET 5.6 and SPSS 20.0 softwares were used for statistical analysis.Results:A total of 961 strains of pathogens were isolated, 516 (53.7%) pathogens were Gram-negative bacteria, mainly 118 strains of Klebsiella pneumonia (12.3%), 68 strains of Pseudomonas aeruginosa (7.1%), 67 strains of Acinetobacter baumannii (7.0%),52 strains of Stenotrophomonas maltophilia (5.4%), 43 strains of Escherichia coli (4.5%), and 42 strains of Enterbacter cloacae (4.4%). There were 171 (17.8%) strains of Gram-positive bacteria and 274 (28.5%) fungi. The drug resistance rates of Pseudomonas aeruginosa and Acinetobacter baumannii to carbapenem were 22.1%-31.3%. Stenotrophomonas maltophilia was sensitive to levofloxacin, compound sulfamethoxazole and minocycline. The antimicrobial resistance rates of these three enterobacteria to carbapenems, cefoperazone/sulbactam, piperacillin/tazobactam were low (<10%). The resistant Gram-positive bacteria to ticoplanin, vancomycin and linazolamide were not detected.Conclusion:The major pathogens related to lower respiratory tract infections in patients with hematological malignancies are gram-negative bacteria in our centre. Different pathogens appear different characteristics of antimicrobial resistance.
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Objective To explore the relationship between T-cell acute lymphoblastic leukemia and the Notch signaling pathway.Methods Human T-cell acute lymphoblastic leukemia SupT1 cells were infected with the lentiviral vector made up specific Notch1-shRNA gene and nonspecific Notch1-shRNA gene.The inhibitive rate of SupT1 cells was detected by CCK-8.The rates of early apoptotic cells (Annexin V+/ 7-AAD-) and late apoptotic cells (Annexin V+/7-AAD+) were analyzed by flow cytometry and the expression levels of Notch1 receptor gene and downstream target genes were assessed by quantitative reverse transcription and polymerase chain reaction (QT-PCR).Results The cell inhibition rates of Notch1 interference group,control group and empty vector group at 96 h were 0.902±0.013,0,and 0.486±0.084,respectively,and it was increased obviously in Notch1 interference group (both P ＜ 0.05).The cell early apoptosis rates of the three groups were (15.27±0.31) ％,(5.57±0.25) ％,(5.80±0.20) ％,respectively.The cell early apoptosis rate of Notch1 interference group was increased obviously compared with the control group and empty vector group (both P ＜ 0.05).While the cell late apoptosis rates had no significant difference among the three groups (P ＞ 0.05).The mRNA expression levels of Notch1 receptor gene and its target genes (Hesl,c-myc,NF-κB) at 48 h,72 h and 96 h were higher than those in the control group and empty vector group (all P ＜ 0.05).Conclusions The specificity of Notch1-shRNA can effectively decrease the Notch1 mRNA expression,and reduce the expression level of downstream target genes.Notch1 cut can inhibit the proliferation of SupT1 cells,and promote the early apoptosis.
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<p><b>BACKGROUND</b>Many researches demonstrate that the secondary brain injury which is caused by autoimmune attack toward brain antigens plays an important role in surgical brain injury (SBI). Although traditional immunosuppression can reduce autoimmune attack, it will lower the body immunity. Immune tolerance, by contrast, not only does not lower the body immunity, but also could lighten autoimmunity. This study used thymus tolerance to develop an immune system that is tolerant to autologous cerebrospinal fluid (CSF) and autologous brain tissue so that autoimmune injury can be suppressed following the disruption of the blood-brain barrier, thereby reducing brain damage.</p><p><b>METHODS</b>Eighty experimental rabbits were divided into five groups by random number table method: 16 in SBI group (group A), 16 in SBI+CSF drainage group (group B), 16 in SBI+CSF drainage+PBS injection group (group C), 16 in SBI+CSF drainage+CSF intrathymic injection group (group D), and 16 in SBI+brain homogenate intrathymic injection group (group E). Rabbits' CSF was drained in group B; was drained and injected PBS into thymus in group C; was drained and injected CSF into thymus in group D; and was injected brain homogenate in group E. Half of the rabbits in each group were phlebotomized on 1st, 3rd, 7th, and 14th days to observe the changes in IL-l, TGF-β by ELISA test, and CD4CD25 regulatory T cells ratio by flow cytometry, and in other animals brain tissues were taken on 7th day for exploring FasL expression by RT-PCR. The least significant difference (LSD) test was used to make paired comparisons; P < 0.05 was considered statistically significant.</p><p><b>RESULTS</b>The levels of FasL, TGF-β, and the ratios of CD4CD25 regulatory T cells in groups D and E were apparently higher than those in other three groups (P < 0.05). Likewise, the levels of IL-1 in these two groups were lower than the other three groups (P < 0.05). Moreover, the ratios of CD4CD25 regulatory T cells and the levels of TGF-β in groups B and C were higher than those in group A, but the level of IL-1 was lower than that in group A (P < 0.05). There was no significant difference between groups B and C, and groups D and E.</p><p><b>CONCLUSION</b>Thymic injection of CSF and brain homogenate may be able to reduce inflammation after SBI, so thymus immune tolerance may be a useful therapy to treat SBI.</p>
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Animals , Rabbits , Autoantigens , Brain , General Surgery , Brain Injuries , Therapeutics , Immune Tolerance , Physiology , Thymus Gland , Allergy and ImmunologyABSTRACT
Objective To detect the proliferation and the expression levels of downstream target genes of Notch pathway of T-ALL CCRF-CEM(CEM)cell line treated with exogenous DLK1 protein,in order to investigatethe effects of DLK1 protein on the Notch pathway in CEM cells.Methods CCK-8 assay was performed to examine the proliferation of CCRF-CEM cells,which were treated with various concentration(0.5,1.0,1.5 μg/ml)DLK1 for various time(24,48,72 h).RFQ-PCR was applied to assess the mRNA expression level of Notch1 receptor and downstream target genes of Notch pathway in CEM cells,which were treated for various time(24,48,72 h).Results DLK1 protein stimulated the proliferation of CCRF-CEM cells,and the proliferation rates with different concentrations of DLK1 were 0.14±0.03,0.17±0.04,0.55±0.01 in 72 hours,respectively,there were statistic differences between that in the experimental group and that in the control group(P＜0.05).DLK1 protein up-regulated the Notch1 receptor and its downstream target genes HES1,c-myc and NF-κB.The relative transcript levels of target genes HES1 in 72 hours,c-myc in 48 hours and NF-κB in 72 hours were 3.2551±0.3100,1.6086±0.0941,2.0515±0.3453 respectively,and there were statistic differences between that in the experimental group and that in the control group(P＜0.05).Conclusion DLK1 protein stimulates the proliferation of T-ALL CCRF-CEM cells by up-regulating Notch1 receptor and downstream target genes HES1,c-myc and NF-κB of Notch pathway.