Objective To construct sigF deletion mutant of Bacillus anthracis and the complementary strain of sigF deletion mutant in order to analyze the effect of losing sigF on formation of spores.Methods The spectinomycinadenyltransferase gene(spc) was inserted to replace sigF of B.anthracis by homologous recombination.A plasmid which contained sigF and sigF promotor was constructed and then transferred to the mutant to get a complementary strain of sigF deletion mutant.The characters of the mutant were analyzed by measuring growth curves, the ability of carbohydrate metabolism was compared, and spore formation was observed under a microscope.Results The sigF deletion strain A16D2△sigF was constructed from A16D2,which had a similar growth rate to the wild type A16D2 in logarithmic phase, but was not significantly different from the initial strain in the ability to use carbohydrates,although unable to form spores.The strain was found to maintain the state of asymmetric division by microfluidics experiment.Conclusion It is showed by this study that sigF is the essential gene of B.anthracis for spore formation, but not essential for vegetative growth.

Objective: To study the mutual effect of EPHA3 gene polymorphism, folic acid intake in early pregnancy, and the occurrence of non-syndromic cleft lip with or without cleft palate, so as to provide the oretical basis for a etiological study on non-syndromic cleft lip with or without cleft palate. Methods: A total of 195 patients and 170 controls were included.The candidate site rs7650466 was genotyped by Snapshot technique.The correlation with folic acid intake in early pregnancy was analyzed. Result: The rs7650466 T allele was highly associated with the pathogenesis of non-syndromic cleft lip with or without cleft palate(OR=0.2472, 95%CI=0.1567-0.3899, P=1.851×10^-9). The T allele had protective effects.Folic acid intake in early pregnancy, and its interaction with EPHA3 gene, were associated with the pathogenesis of this disease(P<0.05). Conclusions EPHA3 gene, folic acid intake during the first trimester, and theinteractionsare associated with the pathogenesis of non-syndromic cleft lip with or without cleft palate.

Objective: To explore the clinical efficacy and safety of unrelated umbilical cord blood transplantation (UCBT) in the treatment of refractory and relapsed acute leukemia (AL) patients. Methods: The clinical data of 22 refractory and relapsed AL patients who were treated with UCBT as salvage therapy from November 2009 to May 2017 were retrospectively analyzed. All patients received a myeloablative conditioning regimen for prevention of graft-versus-host disease (GVHD) with cyclosporine A (CSA)/short course of mycophenolate mofetil (MMF). Results: ①Of 22 patients, 9 cases were male and 13 female. The median age was 23 (15-44) years and median weight of 52.5 (43-82) kg. All patients were transplanted with a median umbilical cord blood nucleated cells of 3.07 (1.71-5.30)×10⁷/kg (by weight), the median CD34⁺ cells was 1.60 (0.63-3.04)×10⁵/kg (by weight). ②The myeloid cumulative implantation rate was 95.5% (95%CI 45.2-99.7%) after transplantation of 42 d, with the median implantation time of 19 (13-27) d. The platelet cumulative implantation rate after transplantation of 120 d was 81.8% (95%CI 54.2-93.6%), the median implantation time of 42 (20-164) d. ③The incidence of Ⅱ-Ⅳ, Ⅲ-Ⅳ aGVHD and the 2 year cumulative incidence of cGVHD were 36.4%, 13.6% and 40.3% respectively. ④ The transplant related mortality (TRM) after transplantation of 180d was 22.7%, 2 year cumulative rate of relapse was 18.7% (95%CI 3.6-42.5%), 2 year disease-free survival rate (DFS) and overall survival rate (OS) were 53.7% and 58.1%, respectively. Conclusion The preliminary results show that the use of UCBT is safe and effective for refractory and relapsed AL patients who fail to respond to conventional chemotherapy.

Objective:To retrospectively analyze the clinical outcomes of single unrelated cord blood transplantation (UCBT) in children with high risk and refractory acute myeloid leukemia (AML) .Methods:Between June 2008 and December 2018, a total of 160 consecutive pediatric patients with AML received single UCBT (excluding acute promyelocytic leukemia) . Myeloablative conditioning (MAC) regimen were applied. All patients received a combination of cyclosporine A (CsA) and mycophenolate mofetil (MMF) for the prophylaxis of graft -versus- host disease (GVHD) .Results:The cumulative incidence of neutrophil cells engraftment at day +42 and platelet recovery at day +120 was 95.0% (95% CI 90.0%-97.5%) at a median of 16 days after transplantation (range, 11-38 days) and 85.5% (95% CI 83.3%-93.4%) with a median time to recovery of 35 days (range, 13-158) , respectively. Incidence of grades Ⅱ-Ⅳ and Ⅲ-Ⅳ acute GVHD and chronic GVHD were 37.3% (95%CI 29.3%-45.2%) , 27.3% (95% CI 20.0%-35.0%) and 22.4% (95% CI 15.5%-28.7%) , respectively. The transplant-related mortality (TRM) at 360 day was 13.1% (95% CI 8.4%-18.9%) . The 5-year cumulative incidence of relapse was 13.8% (95% CI 8.5%-20.3%) . The 5-year disease-free survival (DFS) and overall survival (OS) were 71.7% (95% CI 62.7%-77.8%) and 72.2% (95% CI 64.1%-78.7%) , respectively. The 5-year GVHD and relapse free survival (GRFS) was 56.1% (95% CI 46.1%-64.9%) . The 5-year cumulative recurrence rates of CR1, CR2, and NR groups were 5.3%, 19.9%, and 30.9% ( P=0.001) , and the 5-year OS rates were 79.9% (95% CI 70.3%-86.7%) , 71.1% (95% CI 50.4%-84.4%) and 52.9% (95% CI 33.0%-69.3%) ( χ2=7.552, P=0.020) , respectively. Conclusions:For pediatric patients with high risk and refractory AML, UCBT is a safe and effective treatment option, and it is favorable to improve the survival rate in CR1 stage.