[Influencing Factors of Nosocomial Infection after Chemotherapy in Adult Patients with Acute Myeloid Leukemia and Its Control Strategy].

OBJECTIVE: To investigate the influencing factors of nosocomial infection in adult patients with acute myeloid leukemia (AML) and its control strategies. METHODS: The clinical data of 109 patients with AML treated in our hospital from June 2014 to June 2017 were retrospectively analyzed. The clinical factors were analyzed retrospectively, and the influencing factors of infection after chemotherapy were explored. RESULTS: A total of 109 patients received chemotherapy for 267 case-times, the infection occurred in 168 case-times, the nosocomial infection rate was 62.92%, the main affected sites included upper respiratory tract and lung. 155 samples from 168 case-times infection patients were collected and cultured, 32 pathogens were obtained with a positive rate 20.6% (32/155), including 14 Gram-negative bacteria, 9 Gram-positive bacteria and 4 strains of fungi and 5 strains of other pathogens. Statistics showed that the patient's age over 40 years old, hospitalization in spring and summer, glucocorticoid therapy, high intensity chemotherapy, neutrophil count, white blood cell count and hemoglobin content were the independent risk factors for infection after chemotherapy in AML patients (P<0.05). CONCLUSION: The age of more than 40 years old, hospitalization in spring and summer, glucocorticoid therapy, high-intensity chemotherapy, white blood cell count, neutrophil count and hemoglobin content are the independent risk factors for infection after chemotherapy in the AML patients with the above-mentioned characteristics, they should be closely monitored, and chemotherapy intensity should be controled, so as to control the occurrence of infection; and in the event of infection, a timely powerful anti-infective treatment would be indispensable.

[Effect of Shh and BM-MSC Synergism on the Proliferation of Hematopoietic Stem Cells].

OBJECTIVE: To study the effect and mechanism of shh and mesenchymal stem cell（MSC）synergism on the proliferation of hematopoietic stem cells in noninvasive co-culture system in vitro. METHODS: The mesenchymal stem cells were cultured in vitro，CD34+ cells were sorted by mini MACS magnetic bead separator，flow cytometry was used to identify the purity of 2 cells. CD34+ cells and MSCs were seeded to upper and low of transwell respecibely for non-contact coculture，and add exogenous shh protein for intervenece. The number of MSCs and HSCs，the total amount of RNA，the expression of ki67 and Tie-2 mRNA of HSC，the expression of VEGF and Ang-1 mRNA of MSC were detected for investigating the condition of cell proliferation and the expression of angiogenic factors. RESULTS: The total number of cells，the total amount of RNA and the relative expression of ki67, Tie-2, VEGF and Ang-1 in non-contact co-culture group increased and showed the following trends on the 7th day：the above-mentioned indexes in group MSC + HSC, group shh + HSC were higher than those in group HSC, while those in MSC + shh + HSC Group was higher than those in MSC + HSC and shh + HSC group. CONCLUSION: Angiogenic factors help MSC to proliferate HSC and amplify the CD34+ hematopoietic stem/progenitor cells by shh and MSC synergism in vitro coculture system which may be related with angiogenic factors.