This article deals with the organ culture on hamster trachea under the normal condition. The result showed that the epithelium of trachea could be kept alive up to 8 th-week at most by means of rotatory method of incubation. The culture media are RPMI 1640 (Nissui) and Eagle MEM (Nissui). Each medium was with or without bovine serum added. The results of histological, ultrastructural, radioautographic observations exhibited that the tracheal epithelia of hamster before culture showed ciliated columnar form with cilia. With prolongation of culture time, the changes of tracheal epithelium took the following order, from ciliated columnar to simple columnar and to simple squamous form. These changes were observed in all 4 groups. In radioautography, there are labeling granules in nuclei of tracheal epithelial cells in all 4 groups at different culture time, indicating that the epithelial cells still maintained DNA synthetic activity. TEM observation has showed ultrastructure of tracheal epithelium remained unchanged within 4 weeks. The ciliated cells are well with intact cilia. The intercellular junction is the tight one. Occasionally in accordance with LM observation a few of ciliated cell lacked cilia and its nucleus flattened. In cytoplasm, the dilatation of cisternae of rER and the incresing amount of ribosomes and lysosomes could be seen under TEM. During 7-8 weeks only a part of epithelia of trachea was still kept well, most of them became single layer. The ciliated cells lacked cilia, and their nuclei were long and oval in shape. Some enlarged lysosomes and autophagic vacuoles could be seen in cytoplasm indicating cytoplasmic degeneration. The present study suggested that both Eagle MEM and RPMF 1640 show the same culture effect.

Objective To investigate the threshold of cytomegalovirus (CMV) DNAemia for preemptive antiviral therapy in patients with allogeneic hematopoietic stem cell transplantation (allo-HSCT).Methods Viral load between 1 × 103 copies/ml and 5× 103 copies/ml was defined as low viral load by real time Q-PCR.Clinical data and outcome were collected.Results A total of 95 allo-HSCT recipients with low viral load from September 2014 to February 2015 were recruited in this study.The control group included 37 patients who received preemptive initial antiviral therapy.The other 58 patients didn't received antiviral treatment after positive viremia was confirmed.During monitoring,CMV viremia was cleared spontaneously in 17 patients of study group.Among 41 patients with continuous positive viremia in study group,26 patients received antiviral therapy after second positivity including 18 with viral load ＞5 × 103 copies/ml,2 with fever but still low viral load,2 with hemorrhagic cystitis and low viral load,4 with continuous low viral load.Eleven patients received antiviral therapy after the third positivity including 5 with viral load ＞5×103 copies/ml,1 low viral load patient with fever and diarrhea,5 with continuous low viral load.Only 4 patients received antiviral therapy after the fourth positivity of ＞5× 103 copies/ml.In the study group,35 cases received ganciclovir and 6 cases received foscarnet.The incidence of neutropenia did not differ significantly between study and control groups [minimum of neutrophil count:(1.63±0.41)× 109/L vs.(1.58 ± 0.36) × 109/L].The proportion of viral load greater than 5 × 103 copies/ml in the first week was comparable in two groups.Successful viral clearance rate was not statistically different (P=0.87).Of all 95 patients,no CMV diseases developed,neither did patient die of CMV infection.Conclusions Spontaneous clearance of viremia occurs in some patients receiving allo-HSCT with low CMV viral load.Delayed antiviral treatment of continuous positive viremia does not prolong the whole treatment duration,neither contributes to the progression of CMV diseases.

Objective: To explore the significance of minimal residual disease (MRD) in predicting prognosis and guiding therapy of adults with Philadelphia-chromosome negative acute lymphoblastic leukemia (Ph^- ALL) in high-risk. Methods: Data of newly diagnosed adults with Ph^- ALL in high-risk who achieved CR were reviewed. Variables associated with outcome were identified by COX regression model and Landmark analysis. Results: A total of 177 patients, 99 (56%) cases male with a median age of 40 years (range, 16-65 years) were included in this study. Of them, 95 (54%) patients received allo-HSCT in CR₁. Multivariate analyses showed that MRD negativity after the first cycle of consolidation (HR=0.52, 95%CI 0.30-0.89, P=0.017) and achieving CR within 4 weeks (HR=0.43, 95%CI 0.24-0.79, P=0.006) were the factors significantly-associated with longer DFS, and allo-HSCT was associated with both longer DFS (HR=0.13, 95%CI 0.08-0.22, P<0.001) and OS (HR=0.24, 95%CI 0.15-0.41, P<0.001) . Landmark analysis was performed on 121 patients, of 85 patients achieving MRD negativity after the first cycle of consolidation, multivariate analyses showed that MRD negativity after the third cycle of consolidation was significantly-associated with longer DFS (HR=0.18, 95%CI 0.05-0.64, P=0.008) and OS (HR=0.14, 95%CI 0.04-0.50, P=0.003) . For the patients achieving MRD negativity after both the first and the third cycles of consolidation, the 3-year DFS rate in the allo-HSCT cohort had a higher trend compared with that in the chemotherapy cohort (75.2% vs 51.3%, P=0.082) , however, the 3-year OS rates in the 2 cohorts were similar (72.7% vs 68.7%, P=0.992) . In those with MRD positivity after the first and/or the third cycle of consolidation, 3-year DFS (64.8% vs 33.3%, P=0.006) and OS (77.0% vs 33.3%, P=0.028) rates in the allo-HSCT cohort were significantly higher than those in the chemotherapy cohort, and similar to those in the cohort achieving MRD negativity after both the first and the third cycles of consolidation and receiving allo-HSCT. Conclusions MRD negativity after the first cycle of consolidation was a predictor for better outcome in adults with Ph^- ALL in high-risk. The survival advantage of the allo-HSCT cohort was not pronounced compared with that in the chemotherapy cohort even in those with high-risk features but achieving MDR negativity after both the first and third cycles of consolidation. However, allo-HSCT could be a good option for the patients with MRD positivity after the first and/or the third cycle of consolidation.

Objective: To analyze the genome characteristics of an avian influenza A (H9N2) virus isolated from an 11-month-old infant, and to look for possible sources of infection. Methods: Throat swabs were collected from an infant with influenza-like illness in influenza sentinel surveillance hospitals and isolated for influenza viruses using cells. The isolates were identified for influenza virus types and subtypes by the method of hemagglutination assay, hemagglutination inhibition assay and fluorescence PCR. Whole genome sequencing of the isolated virus was carried out. The genome nucleic acid sequences and the deduced amino acid sequences were analyzed by comparing the phylogenetic trees which were constructed by bioinformatics software. Results: A seasonal un-typed influenza virus was isolated from the infant with influenza like illness. With fluorescent PCR method , it was identified as H9N2 subtype of avian influenza virus and the case was confirmed as a human infected with an avian influenza A(H9N2) virus. Epidemiological studies revealed that the case had no clear history of poultry contact and exposure. Blast analysis shows that eight segments of the viral genome are avian origin, and 97.5%-99.8% homology with that of viruses isolated from the live-poultry markets. The virus belongs to G57 genotype, deduced amino acid sequence analysis shows that the virus has typical low pathogenic avian influenza characteristics. Conclusions Although the case does not have a clear history of contact or exposure to poultry, molecular traceability suggests that possible sources of infection may be still from poultry.

Objective:To explore the relationship between anti-human leukocyte antigen (HLA) antibodies and transplant outcomes in patients with hematological diseases who underwent matched sibling donor transplantation (MSDT).Methods:A retrospective analysis was conducted in 168 patients with hematological diseases who received MSDT in Peking University People's Hospital from March 2015 to November 2017. All patients received detection of anti-HLA antibodies before transplantation, and the correlation between anti-HLA antibodies and transplant outcomes such as hematopoietic cells implantation, blood product transfusion and prognosis after transplantation were analyzed.Results:Among the 168 patients, 28 (16.7%) were positive for anti-HLA class Ⅰ or class Ⅱ antibodies, and 14 (8.3%) were positive for both anti-HLA class Ⅰ and class Ⅱ antibodies. All patients received neutrophil engraftment, 164 patients (97.9%) received platelet engraftment. Univariate analysis showed that there were no effects of anti-HLA antibodies on neutrophil engraftment and engraftment time, platelet engraftment and engraftment time, the volume of red cell transfusion, the volume of platelet transfusion, overall survival (OS) rate, disease free survival (DFS) rate and transplant-related mortality (TRM) in patients with hematological diseases underwent MSDT (all P > 0.05). Multivariate analysis showed that platelet engraftment was associated with better OS ( HR=0.065, 95% CI 0.017-0.252, P < 0.01), better DFS ( HR=0.083, 95% CI 0.024-0.289, P < 0.01) and lower TRM ( HR=0.094, 95% CI 0.014-0.626, P=0.015). Conclusion:Anti-HLA antibodies have no effect on transplant outcomes of patients with hematological diseases who have received MSDT.

Objective:To investigate the value of minimal residual disease (MRD) in prediction of prognosis in acute lymphoblastic leukemia (ALL) patients with or above complete remission 2 (CR2) underwent.Methods:A retrospective analysis was performed on 201 ALL patients who received allogeneic stem cell transplantation (allo-SCT) and pretransplant disease status ≥CR2 in Peking University People′s Hospital from January 2009 to December 2018. MRD was measured by multi-parameter flow cytometry at 1 month before transplantation and 1 month, 2 months, 3 months, 4 months, 6 months, 9 months or 12 months after transplantation. To investigate the influence of dynamic changes of MRD before and after transplantation on prognosis.Results:201 ALL patients, including 126 males and 75 females, with a median age of 18 years. The 3-year cumulative incidence of relapse (CIR), non-relapse mortality (NRM), leukemia-free survival (LFS) and overall survival (OS) of all cases were 34%, 16%, 50%, and 56%, respectively. Positive pre-SCT MRD patients with higher 3-year CIR (47% vs 26%, P=0.003), lower 3-year LFS (40% vs 55%, P=0.047) and OS (42% vs 60%, P=0.065) than those with negative one. Subjects with positive post-MRD had higher 3-year CIR (73% vs 22%, P<0.001) and lower 3-year LFS (28% vs 56%, P=0.005) and OS (32% vs 60%, P=0.040) compared with those with negative one. Multivariate analysis showed that both pre-MRD and post-MRD were associated with higher CIR ( HR=1.823, P=0.018; HR=3.474, P<0.001), lower LFS ( HR=1.779, P=0.007; HR=2.185, P=0.001) and OS ( HR=1.609, P=0.034; HR=1.970, P=0.001). Negative pre-and post-SCT MRD group had lower 3-year CIR (17%, 42%, 82%; P<0.001) and higher 3-year LFS (61%, 44%, 18%; P<0.001) and OS (63%, 47%, 27%; P<0.001) compared with those unrisen post-SCT MRD group, and increased post-SCT MRD group. Multivariate analysis showed that pre-and post-SCT MRD dynamics were associated with CIR, LFS and OS ( P<0.01 for all) independently. The pre-and post-SCT MRD dynamics could better distinguish CIR (C=0.669) from that of pre-SCT MRD (C=0.587) and post-SCT MRD (C=0.629). Conclusion:Our data suggest that pre-SCT MRD, post-SCT MRD and the dynamic peri-SCT MRD could be used to predict transplant outcome of ALLpatients with or above CR2 who underwent allo-SCT.