Leukemia is one of the common tumors,and it seriously harms to the health.The more serious environmental pollutions become,the more people pay attention to the relationship between environmental exposures and leukemia,especially children leukemia.To discuss the progress of study on formaldehyde and leukemia,this study states the characteristics of formaldehyde,the resources of formaldehyde indoor air and the harms to health,toxicity and human cancinogenicity,and reviews the researches on the relationship between formaldehyde and leukemia.It concludes that there is "strong but not sufficient evidence for a causal association between leukemia and occupational exposure to formaldehyde".

Objective To explore the DNA-protein crosslink(DPC) induced by formaldehyde(FA) and the repair.Methods Three-month-old Wistar male rats were used as the experimental animals and exposed to gaseous FA at the doses of 0,0.5,1.0,3.0 mg/m3 respectively through continuous inhalation for 72 h.The cellular suspension of the lungs and kidneys was exposed to FA at the doses of 0,25,50,100,150 and 200 ?mol/L respectively for 1 h.The KCl-SDS assay was used to detect the coefficient of DPC in the lung and renal cells.The repair at 0,6,12,18 and 24 h exposure points was determined in the exposure test of 3.0 mg/m3 for 72 h in vivo and 75 ?mol/L for 1 h in vitro.Results Higher gaseous FA(≥1.0 mg/m3) could significantly cause DPC(P

0.05).Conclusion The study suggests that the coefficient of DNA-protein crosslinks can be increased significantly by higher concentrations of FA in A549 cell lines.DPC induced by FA could be repaired.

Objective To study the curative efficacy and safety of single-unit umbilical cord blood transplantation (sUCBT) for malignant hematologic diseases,which is provided by China's public cord blood bank.Methods We retrospectively analyzed 409 cases of malignant hematologic diseases who accepted myeloablative single-unit unrelated donor UCBT without ATG at our center between May 2008 and December 2016.A comparative analysis was made on the total nuclear cells (TNC) of the umbilical cord blood before freezing and after thawing,the cells of CD34+,the recovery rate of cells and the clinical effect of UCBT.Result 409 units of umbilical cord blood used in UCBT respectively came from eight China's public cord blood banks.The average TNC of 409 units of umbilical cord blood before freezing and after the tubular recovery were respectively 18.5 × 108 and 16.34 × 108 (p =0.000).The average recovery rate of the tubular recovery was 88.5％,and there was significant difference among cord blood banks (P =0.000).The average TNC of umbilical cord blood before freezing and transfusion were respectively 18.5 × 108 and 15.86 × 108 (p =0.000).The average recovery rate of umbilical cord blood transfusion was 85.9％,with the difference being significant among cord blood banks (P =0.000).The average number of CD34+ cells before freezing and after the tubular recovery was 11.18 × 106and 8.68 × 106 (p =0.000).The average recovery rate of CD34+ cells after the tubular recovery was 80.75 ％,with the difference being significant among the cord blood banks (P =0.000).At 42nd day after UCBT,the cumulative incidence of neutrophil engraftment was 95.4％,and the median time of the engraftment was 17 days (11-38 days).The cumulative incidence of platelet engraftment at 120th day was 84.6％,and the median time of the engraftment was 36 days (14-93 days).The cumulative incidence of erythrocyte engraftment at 60th day was 92％,and the median time of engraftment was 22 days (9d-60 days).After the umbilical cord blood provided by each bank was used in UCBT,it got the difference in cumulative incidence of engraftment.The P values for cumulative incidence of neutrophil,platelet and erythrocyte engraftment were respectively 0.004,0.01 and 0.000 2,with the differences being statistically significant.At 100th day after UCBT,the cumulative incidence of Ⅱ-Ⅳ and Ⅲ-Ⅳ degrees of acute graft-versus-host disease (aGVHD) was respectively 28.63％ and 15.7％.After umbilical cord blood provided by each bank was used in UCBT,it got the difference in cumulative incidence of aGVHD.There was no significant difference between Ⅱ-Ⅳ and Ⅲ-Ⅳ degrees (P =0.809 and 0.68 respectively).At 3rd year after UCBT,the cumulative incidence of relapse was 15.89％.After umbilical cord blood provided by each bank was used in UCBT,there was no significant difference in the cumulative incidence of relapse (P =0.898).At 3rd year after UCBT,the overall survival (OS) rate and disease free survival (DFS) rate were respectively 66.7％ and 59％.After umbilical cord blood provided by each bank was used in UCBT,it got the difference in OS and DFS.There was no significant difference in OS and DFS (P =0.566 and 0.703 respectively).At 3rd year after sUCBT,the rate of graft-versus-host diseases/relapse-free survival (GRFS) was 54.3％.After umbilical cord blood provided by each bank was used in UCBT,there was no significant difference in the rate of GRFS (P =0.449).Conclusion The umbilical cord blood provided by China's public cord blood bank was used in UCBT.It has a high safety and good efficacy in treating malignant hematologic diseases.But it needs to set up the standardized and normalized quality-control system of umbilical cord blood for China's public cord blood bank.