Droplet digital PCR for BCR/ABL(P210) detection of chronic myeloid leukemia: A high sensitive method of the minimal residual disease and disease progression.

OBJECTIVE: This study intended to establish a droplet digital PCR (dd-PCR) for monitoring minimal residual disease (MRD) in patients with BCR/ABL (P210)-positive chronic myeloid leukemia (CML), thereby achieving deep-level monitoring of tumor load and determining the efficacy for guided clinically individualized treatment. METHODS: Using dd-PCR and RT-qPCR, two cell suspensions were obtained from K562 cells and normal peripheral blood mononuclear cells by gradient dilution and were measured at the cellular level. At peripheral blood (PB) level, 61 cases with CML-chronic phase (CML-CP) were obtained after tyrosine kinase inhibitor (TKI) treatment and regular follow-ups. By RT-qPCR, BCR/ABL (P210) fusion gene was undetectable in PB after three successive analyses, which were performed once every 3 months. At the same time, dd-PCR was performed simultaneously with the last equal amount of cDNA. Ten CML patients with MR4.5 were followed up by the two methods. RESULTS: At the cellular level, consistency of results of dd-PCR and RT-qPCR reached R2  ≥ 0.99, with conversion equation of Y = 33.148X1.222 (Y: dd-PCR results; X: RT-qPCR results). In the dd-PCR test, 11 of the 61 patients with CML (18.03%) tested positive and showed statistically significant difference (P < .01). In the follow-up of 10 CML patients who were in MR4.5. All patients were loss of MR4.0, and 4 were tested positive by dd-PCR 3 months earlier than by RT-qPCR. CONCLUSION: In contrast with RT-qPCR, dd-PCR is more sensitive, thus enabling accurate conversion of dd-PCR results into internationally standard RT-qPCR results by conversion equation, to achieve a deeper molecular biology-based stratification of BCR/ABL(P210) MRD. It has some reference value to monitor disease progression in clinic.

Dehydrocostuslactone, a sesquiterpene lactone activates wild-type and ΔF508 mutant CFTR chloride channel.

Cystic fibrosis transmembrane conductance regulator (CFTR) represents the main cAMP-activated Cl⁻ channel expressed in the apical membrane of serous epithelial cells. Both deficiency and overactivation of CFTR may cause fluid and salt secretion related diseases. The aim of this study was to identify natural compounds that are able to stimulate wild-type (wt) and ΔF508 mutant CFTR channel activities in CFTR-expressing Fischer rat thyroid (FRT) cells. We found that dehydrocostuslactone [DHC, (3aS, 6aR, 9aR, 9bS)-decahydro-3,6,9-tris (methylene) azuleno [4,5-b] furan-2(3H)-one)] dose dependently potentiates both wt and ΔF508 mutant CFTR-mediated iodide influx in cell-based fluorescent assays and CFTR-mediated Cl⁻ currents in short-circuit current studies, and the activations could be reversed by the CFTR inhibitor CFTRinh-172. Maximal CFTR-mediated apical Cl⁻ current secretion in CFTR-expressing FRT cells was stimulated by 100 µM DHC. Determination of intracellular cAMP content showed that DHC modestly but significantly increased cAMP level in FRT cells, but cAMP elevation effects contributed little to DHC-stimulated iodide influx. DHC also stimulated CFTR-mediated apical Cl⁻ current secretion in FRT cells expressing ΔF508-CFTR. Subsequent studies demonstrated that activation of CFTR by DHC is forskolin dependent. DHC represents a new class of CFTR potentiators that may have therapeutic potential in CFTR-related diseases.

[The activation effect of nobiletin on cystic fibrosis transmembrane conductance regulator chloride channel].

Aim of the present study is to investigate activation effect of nobiletin on cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel activity. CFTR-mediated iodide influx assay and patch-clamp tests were done on FRT cells stably co-transfected with human CFTR and EYFP/H148Q. Nobiletin potently activated CFTR chloride channel activity in a dose- and time-dependent manner. The CFTR blocker CFTR(inh)-172 could completely reverse the effect. Preliminary mechanism study indicated that nobiletin activated CFTR chloride channel through a direct binding way. In addition, ex vivo tests done on mice trachea showed that nobiletin time-dependently stimulated submucosal gland fluid secretion. Nobiletin may be a therapeutic lead compound in treating CFTR-related diseases including disseminated bronchiectasis.

[Effects of Nitrogen Speciation Transformation on Microbial Community Succession in Input Rivers of Miyun Reservoir].

The Miyun Reservoir is the major source of surface drinking water in Beijing. However, the total nitrogen (TN) concentrations in the Miyun Reservoir and inflowing rivers have recently been increasing. In this study, the Mangniu River, a typical inflow river in the upper reaches of the Miyun Reservoir, was selected as the study area to investigate the spatial distribution and transformation of various nitrogen forms from the perspective of microbial community composition and predicting function, aimimg at providing a scientific reference for nitrogen pollution control of the Miyun Reservoir. The results indicated that except for TN, all the other physical and chemical water quality indicators in the upper reaches of the Miyun Reservoir met the Class II criteria of the environmental quality standards for surface water in China (GB 3838-2002). Additionally, NO3--N was the primary constituent of TN, ranging from 77.7% to 92.9%. Banchengzi Reservoir has a certain self-purification ability because its high C/N ratio promotes denitrification. Significant differences in microbial community structure were observed between the water and sediments of Mangniu River along with spatial distribution. High NO3--N concentration was the major environmental factor affecting the succession of microbial community structure. Many nitrification and denitrification microorganisms existed in Mengniu River, and the relative abundance of denitrification bacteria (DNB) was higher than that of nitrification bacteria, and that in the sediments was slightly higher than that in the water. Nitrosopumilus and Pseudomonas were the dominant nitrification and denitrification bacteria in Mengniuhe River, respectively. The results of phylogenetic investigation of communities by the reconstruction of unobserved states (PICRUSt2) showed that NO3--N reduction module was the major nitrogen metabolism module, which primarily occurred in water. The abundance of the functional genes for nitrification (i.e., narGH) was the highest in water, and the major functional gene involved in NO3--N reduction was nirBD of DNRA, which was primarily present in the sediments; however, the main functional gene involved in denitrification was nirK.

[Clinical Efficacy and Survival Analysis of Adult Patients with Acute Myeloid Leukemia after Microtransplantation].

OBJECTIVE: To investigate the clinical efficacy and survival factors of microtransplantation (MST) in adult patients with acute myeloid leukemia (AML). METHODS: For a retrospective analysis of 27 adult patients with AML receiving MST from July 2014 to October 2021, the median age was 59(29-77) years old, 13 cases were ≥60 years old, 14 case were <60 years old, 13 cases were male and 14 cases were female. Classification by FAB: AML-M2 6 cases, AML-M4 6 cases, AML-M5 2 cases, AML-M6 2 cases, AML（Undivided type） 9 cases, AML myeloid sarcoma 2 cases (primary AML 21 cases, AML secondary to MDS 6 cases). Cytogenetic analysis showed 25 patients with a normal karyotype, 2 patients with an abnormal karyotype, and 20 patients with an abnormal molecular biology. Induction chemotherapy regimens mainly include: IA, DA, MA or HA regimen, including CAG or CIG in combination with decitabine, and single-agent decitabine. 17 patients achieved complete remission (CR) after 1 course of induction chemotherapy and 4 patients achieved CR after 2 courses of induction chemotherapy. 3 patients received CR by four courses of decitabine, 2 patients received no remission, and 1 patient underwent no induction chemotherapy and were treated direct MST. There were 16 patients with pretransplant CR and 11 patients were not in remission before transplantation. Follow-up mainly used consult patient's medical records and telephone inquiry to observe the adverse effects and efficacy of MST treatment. Survival analysis was performed by Kaplan-Meier method, with the main observation indicators overall survival(OS) and leukemia-free survival(LFS), and performed with the Log-rank test. Multivariate analysis was performed by the Cox regression model. RESULTS: A total of 79 MST were performed in 27 AML patients with good overall safety and no special serious adverse effects. The median time of leukocyte recovery was 13(4-28) days, and the median time of platelet recovery was 13(4-30) days. There were 50 cases of infection, 5 cases of abnormal liver function and 3 cases of abnormal cardiac function. Except for abnormal cardiac function, all other complications did not affect the treatment and were cure. Acute or chronic GVHD, renal insufficiency, abnormal coagulation function, and severe bleeding were not observed during treatment or during follow-up. As of the follow-up date, the median follow-up time of the 27 patients was 79(14-171) months, the median OS time was 62(1-171) months, and the median LFS time was 15(0-171) months. The 2-year OS rate was 65.7%（17/27）, and the 2-year LFS rate was 47.4%（12/27） . The complete response rate of 27 patients treated with MST was 48.1% (13/27). 8 patients relapsed during MST treatment, including 7 patients after the completion of the first MST course and 1 patient after the completion of the second MST course. 2 patients relapsed after the end of the course of MST. 13 patients died, including 10 patients because of disease progression, two patients from severe infection, and one patient from cardiac damage. CONCLUSION: MST has the advantages of small toxic side effects, complete compatibility of HLA matching is not required, effective avoidance of GVHD and rapid hematopoietic recovery, which can improve OS and LFS in elderly AML and young AML patients, and is one of the treatment options for patients without HLA matching.

Leonurine-Repressed miR-18a-5p/SOCS5/JAK2/STAT3 Axis Activity Disrupts CML malignancy.

Leonurine, an active natural alkaloid compound isolated from Herba leonuri, has been reported to exhibit promising anticancer activity in solid tumors. The aim of this study was to explore whether leonurine is able to inhibit chronic myeloid leukemia (CML) malignancy. Here, we found that leonurine dose dependently inhibited the proliferation, migration, colony formation and promoted apoptosis of CML cells. Furthermore, leonurine markedly reduced CML xenograft growth in vivo. Mechanically, leonurine upregulated SOCS5 expression, thus leading JAK2/STAT3 signaling suppression. Silencing of SOCS5 by its siRNA abrogated the effect of leonurine on CML cells, demonstrating that SOCS5 mediates the anti-leukemia effect of leonurine. Notably, we observed that miR-18a-5p was remarkably increased in CML cells. Treating CML cells with leonurine significantly decreased miR-18a-5p expression. Moreover, we found miR-18a-5p repressed SOCS5 by directly targeting its 3'-UTR. miR-18a-5p downregulation induced by leonurine reduced the biological activity of CML cells by relieving miR-18a-5p repression of SOCS5 expression. Taken together, leonurine exerts significant anti-leukemia efficacy in CML by regulating miR-18a-5p/SOCS5/JAK2/STAT3 axis.

[Quantitative Analysis on Immunophenotype of CD34+ Myeloid Precursor Cells in Myelodysplastic Syndrome and Its Correlation with Clinical Features].

OBJECTIVE: To investigate the quantitative expression of immunophenotype of CD34+ myeloid precursor cells in myelodysplastic syndrome (MDS) patients and its correlation with clinical characteristics, and understand the effect of quantitative expression of CD7 and CD117 on the prognosis of low-risk MDS patients. METHODS: Multi-parameter flow cytometry (FCM) was used to detect the proportion and mean fluorescence intensity (MFI) of each antigen of bone marrow CD34+ myeloid precursor cells in 79 MDS patients. The correlation between the expression level of each immune marker and clinical characteristics was compared. The effects of quantitative expressions of CD7 and CD117 on the overall survival rate of low-risk patients were explored. RESULTS: Bone marrow blast cell proportion (P<0.01), RBC level (P<0.01), and Hb level (P<0.05) of high-risk MDS patients were higher, while EPO level (P<0.05) was lower than those of low-risk patients. The proportion of CD34+ blast cells (P<0.01), the proportion of CD117 (P<0.05) and the MFI of CD7 (P<0.05) were higher in high-risk patients than those in low-risk patients, but the MFI of CD123 was lower (P<0.05). In high-risk MDS patients, CD15/CD34 (MFI) and CD19/CD34 (MFI) positively correlated with the proportion of total T cells (r=0.458; r=0.505), while CD19/CD34 (%) and CD19/CD34 (MFI) negatively correlated with WBC levels (r=-0.469; r=-0.503). In low-risk MDS patients, CD34+ (%) positively correlated with bone marrow erythrocyte proportion, PLT level and neutrophil level (r=0.426; r=0.486; r=0.495), but negatively correlated with LDH level (r=-0.421); WT1 expression level was positively correlated with CD10/CD34 (%), CD10/CD34 (MFI) and CD117/CD34 (MFI) (r=0.745; r=0.800; r=0.434), while negatively correlated with CD11b/CD34 (%)(r=-0.457); CD19/CD34 (%) and CD71/CD34 (MFI) negatively correlated with NK cell proportion (r=-0.786; r=-0.514); CD10/CD34 (%) positively correlated with Th/Ts, while CD7/CD34 (MFI) negatively correlated with the proportion of Th cells (r=0.738; r=-0.513); HLADR/CD34 (%) and HLADR/CD34 (MFI) negatively correlated with PLT level (r=-0.461; r=-0.445), while HLADR/CD34 (MFI) positively correlated with bone marrow NAP fraction (r=0.552). The quantitative expression of CD7 and CD117 had no significant effect on the overall survival rate of low-risk MDS patients. CONCLUSION: The immunophenotype of CD34+ myeloid precursor cell in different risk groups in MDS patients is related to clinical characteristics. Bone marrow cell morphology, clinical and laboratory features and immunophenotype will be of great significance to the diagnosis, clinical classification and prognosis evaluation of MDS patients.

[Analysis of Spatial-Temporal Variation Characteristics of Potential Non-point Source Pollution Risks in the Upper Beiyun River Basin Using Different Weighting Methods].

Non-point source pollution has become an important factor affecting the aquatic ecological environment and human health, and the analysis of spatial-temporal variations in non-point source pollution risks is an important prerequisite for pollution control. Based on land-use and land-cover data from 1980 to 2020, the potential non-point source pollution index (PNPI) model was applied in the upper Beiyun River Basin using different weighting methods. The results showed that:① The potential risk of non-point source pollution is high in the southeast and low in the northwest of the basin. Between 1980 and 2020, the total area of extremely high-risk and high-risk non-point source pollution regions showed a decreasing trend, and the main types of land use for extremely high-risk and high-risk regions gradually evolved from paddy fields, drylands, and orchards to urban and rural residential land; ② The weighting of the land use index determined by the mean-square deviation decision, entropy, coefficient of variation, and expert scoring methods was largest among the three PNPI indices, with average weightings of 0.46, 0.53, 0.45, and 0.48, respectively. However, the weightings for runoff and distance indices determined by different weighting methods were notably different, and the proportions of regions with different levels of non-point source pollution risk also varied; ③ The exponential function method, which describes the relationship between source factors and transport factors by constructing the exponential functions of land use, runoff, and distance indices, provided results that are more consistent with the spatial distribution characteristics of non-point source pollution risk in the basin. The proportions of extremely low-risk and extremely high-risk regions are 54.22% and 6.23%, respectively. These results provide scientific reference for risk analysis and the control of non-point source pollution in this basin.

[Effect of Signal Transduction Pathway Gene Mutations on the One- course Induced Remission Rate and Analysis of Clinical Characteristics in Patients with CBF-AML].

OBJECTIVE: To investigate the effect of other gene mutations outside the fusion gene on the first complete remission (CR1) induced by one course of induction chemotherapy in patients with core binding factor-associated acute myeloid leukemia (CBF-AML). METHODS: DNA was extracted from bone marrow or peripheral blood samples of newly diagnosed CBF-AML patients admitted to the Hematology Department of the Second Hospital of Shanxi Medical University from January 2015 to January 2019. Next-generation sequencing was used for detection of 34 kinds of hematologic malignancy-related gene mutations in patients with CBF-AML, the effect of related gene mutations on the first complete remission (CR1) rate in one course of induction chemotherapy was analyzed by combineation with clinical characteristics. RESULTS: 34 kinds of genes in bone marrow or peripheral blood of 43 patients were detected by high throughput sequencing and the gene mutations were detected in 16 out of 34 genes. The mutation rate of KIT gene was the highest (48.8%), followed by NRAS (16.3%), ASXL1 (16.3%), TET2 (11.6%), CSF3R (9.3%), FLT3 (9.3%), KRAS (7.0%). The detection rates of mutations in different functional genes were as follows: genes related with signal transduction pathway (KIT, FLT3, CSF3R, KRAS, NRAS, JAK2, CALR, SH2B3, CBL) had the highest mutation frequency (72.1% (31/43); epigenetic modification gene mutation frequency was 30.2% (13/43), including ASXL1, TET2, BCOR); transcriptional regulation gene mutation frequency was 7.0% (3/43), including ETV6, RUNX1, GATA2). Splicing factor related gene mutation frequency was 2.3% (1/43), including ZRSR2). The CR1 rate was 74.4% after one course of induction chemotherapy. At first diagnosis, patients with low expression of WT1 (the median value of WT1 was 788.9) were more likely to get CR1 (P=0.032) and the RFS of patients who got CR1 after one course of induction chemotherapy was significantly longer than that of patients without CR1 [7.6 (2.2-44.1) versus 5.8 (1-19.4), (P=0.048)]. The rate of CR1 in the signal transduction pathway gene mutation group was significantly lower than that in non-mutation group (64.5% vs 100%) (P=0.045), while the level of serum hydroxybutyrate dehydrogenase (HBDH) was significantly higher than that in non-mutation group [(418 (154-2702) vs 246 (110-1068)] (P=0.032). There was no difference in CD56 expression between the two groups (P=0.053), which was limited to the difference between (≥20%) expression and non-expression. (P=0.048). CONCLUSION: CBF-AML patients with signal transduction pathway gene mutation are often accompanied by high HBDH level and CD56 expression, moreover, the remission rate induced by one course of treatment is low.

[Clinical Efficacy of Modified BU/CY as Conditioning Regimen Combined with Autologous Peripheral Blood Hematopoietic Stem Cell Transplantation in Young Acute Myeloid Leukemia Patients with Low or Intermediate Risk].

OBJECTIVE: To investigate the safety and efficacy of autologous peripheral blood hematopoietic stem cell transplantation (auto-PBHSCT) using modified BU/CY conditioning regimen for young AML patients of low and middle risk in the first complete remission (CR1). METHODS: Ten young AML patients of low and middle risk who did not want to accept allogeneic hematopoietic stem cell transplantation（allo-HSCT）and underwent auto-PBHSCT in CR1 during May 2013 to December 2016 were retrospectively analyzed. From 3 months after auto-PBHSCT, the maintenance therapy with interleukin-2 (IL-2) or IL-2 combined with histamine dihydrochloride was performed for these patients in the next 18 months. The side effects of the conditioning regimen, hematopoietic recovery time, transplant-related mortality (TRM) within 100 days and 1 year after auto-PBHSCT, relapse rate, leukemia-free survival (LFS) rate at 2 years and 3 years, overall survival (OS) were evaluated at 3 years and 4 years. RESULTS: Gastrointestinal side effects were the major non-hematologic toxicity reaction, among which, 7 cases relatively mild and 3 cases displayed moderate, just one case suffered from severe reaction. In 4 cases, the mild liver damage occurred, but no hemorrhagic cystitis occurred. All the patients experienced different kinds of infection, including 5 cases of bloodstream infection, 2 cases of gastrointestinal infection, 3 cases of crissum infection and 2 cases of oral infection. The myeloablative effect occurred in all ten patients. The median times for absolute neutrophil count (ANC)<0.5×109/L and for platelet count <20.0×109/L were 1.5 (0-3) days and 3 (2-5) days after transplantation, respectively. The patients achieved ANC>0.5×109/L at 10 to 19 days, median was 13 days after auto-PBHSCT. The patients achieved platelet count >20×109/L at 10 to 72 days; median was 32 days after auto-PBHSCT. The TRM within 100 days and 1 year after transplantation was 0. The relapse occurred in 2 cases at 6 and 14 months after auto-PBHSCT raspectively. The median follow-up time was 48.1 months, and the median survival time was 54.7 months after transplantation. The 2-year and 3-year LFS were 100% (10 cases) and 80% (8 cases), respectively. The 3-year and 4-year OS were 80% (8 cases) and 70% (7 cases), respectively. CONCLUSION: Modified BU/CY as conditioning regimen for auto-PBHSCT can achieve the myeloablative effect without raising TRM and obtain good LFS and OS. As for young AML patients without high risk, it is a valuable therapeutic option, especially for those lacking the chance of allo-HSCT.

Response to corticosteroids and cytotoxic drugs in a case of idiopathic hypereosinophilic syndrome with predominantly elevated eosinophils and multiple clinical manifestations.

In the present case study, a 42-year-old Chinese woman fulfilling the WHO criteria for idiopathic hypereosinophilic syndrome (IHES) who exhibited clinical manifestations of eosinophilic infiltration of multiple tissues including the lungs, heart, central and peripheral nervous system, gastrointestinal tract, spleen, liver and unexplained clinical findings is described. Laboratory investigations revealed the topmost white blood cell and eosinophil that were 150 × 10(9)/L and 136 × 10(9)/L (90.6 %), respectively. To our knowledge, such a large number of eosinophils has rarely been reported, and all reactive causes of hypereosinophilia were excluded. Treatment with cytotoxic chemotherapy, prednisone and dexamethasone was not beneficial. The patient showed a remarkable hematological response when methylprednisolone pulse therapy was initiated when progression of respiratory symptoms occurred, but without clinical remission. The patient subsequently died. We consider that her critical organ damage and poor prognosis were related to the large number of eosinophils and delayed effective anti-eosinophilic therapy after severe organ damage occurred. This case highlights the clinical importance of methylprednisolone pulse therapy which should be initiated without delay once the diagnosis of IHES is made.

[Expression of CD25 in acute B cell lymphoblastic leukemia and its clinical significance].

This study was purposed to investigate the relation of CD25 with the acute B cell lymphoblastic leukemia (B-ALL) and its clinical significance. A totol of 88 newly diagnosed B-ALL patients were enrolled in this study. The immunophenotype of leukemic myeloblasts were detected by flow cytometry, including interleukin 2 receptor α chain (CD25), ß chain (CD122), γ chain (CD132), CD19, CD20, CD10, CD34, CDIgM, CD79a, CD22 and CDTDT. The expression of BCR/ABL fusion gene was detected by qualitative PCR. The expression of IL2RA (CD25 gene) was detected by real-time qualitative RT-PCR. The results showed that there was no significant statistical difference in WBC count, Hb level, PLT count, marrow blast rate, peripheral blast rate, hepato-lienal infiltration, lymph node infiltration, levels of CD10, CD20, CD22, CD34, CD79a, CDTDT, CDIgM expression between B-ALL patients with CD25(+) and B-ALL patients with CD25(-), while the CD19 expression level in B-ALL patients with CD25(+) was higher than that in B-ALL patients with CD25(-). Out of 88 B-ALL patients, 21 patients showed BCR/ABL(+)(21/88) and their CD25(+) expression level was 66.7% (14/21); 67 patients showed BCR/ABL(-) and their CD25(+) expression level was 4.5% (3/67), there was statistical difference between these two groups (P < 0.05), but the expression level of IL2RA mRNA was not statistical different between CD25(+) and CD25(-) groups (P > 0.05). Among 21 BCR/ABL(+) B-ALL patients the remission rate and relapsed rate were not statistical different between CD25(+) an CD25(-) groups.In BCR/ABL(+) B-ALL patients 8 patients relapsed, the relapsed rate was 38.1% (8/21). In BCR/ABL(-) B-ALL patients 9 patients relapsed, the relapse rate was 13.4% (9/67), there was statistical difference between BCR/ABL(+) and BCR/ABL(-) two groups (P < 0.05). In BCR/ABL(+) group the RFS (relapse free survival) was 21 months, in BCR/ABL(+) CD25(+) patients the RFS was 15 months, while in BCR/ABL(+) CD25(-) patients the RFS was 21 months, in BCR/ABL(-) CD25(-) patients, the RFS was 24 months. It is concluded that the CD25 expresses at high level in B-ALL patients with BCR/ABL(+), which may serve as a predictive marker for the presence of BCR/ABL fusion gene, and relates with relapse, CD25(+) may serve as a adjuvant indicator for poor prognosis.

[Detection of intron 22 inversion of factor VIII gene in severe hemophilia A patients].

OBJECTIVE: To investigate the incidence of intron 22 inversion (INV22) of factor VIII (FVIII) gene in severe hemophilia A (HA) patients, clarify its pathological mechanism, and identify INV22 carrier in the female family members. METHODS: One-stage method was used to assay the FVIII activity (FVIII:C)in 126 severe HA patients with a median age of 14 years old (range: 4 months-63 years). INV22 was analyzed by long-distance polymerase chain reaction (LD-PCR) and pulsed field gel electrophoresis (PFGE), and pedigree were conducted in 3 involved HA families. RESULTS: Of all the 126 severe HA, 52 (41.3%) cases had the INV22. Four females including 3 mothers and 1 sister of probands were diagnosed as INV22 carriers among 11 suspected carrier mosaicisms from 3 INV22 positive HA families. In 8 females from one family without HA history, the patient's mother was a INV22 carrier, but her maternal grandmother, 2 maternal aunts, 2 female siblings and 1 elder female cousin were negative. CONCLUSION: LD-PCR and PFGE could be used to diagnose severe HA patients with INV22 and identify the carriers.

[Construction and identification of recombinant adenoviral vector for antisense klf4 gene].

This study was aimed to construct a recombinant adenovirus vector for antisense klf4 gene through AdEasy system. Human klf4 cDNA was reversely inserted into the multiple cloning sites (MCS)of the pShuttle-CMV by using the backbone plasmid AdEasy-l, the antisense klf4 gene was constructed through homologous recombination in E.coli BJ5183, then the adenoviruses were packaged and amplified in the HEK 293 ce1ls. The adenovirus vector for antisense klf4 gene confirmed by PCR, restriction analysis and DNA sequencing. After being transfected with the adenoviruses at 200 MOI for 48 hours, total RNA and protein were extracted from human umbilical vein endothelial cells (HUVEC). Klf4 mRNA and KLF4 protein expression levels were evaluated by Real-time PCR and Western-blot. The results showed that the recombinant adenovirus vector for antisense klf4 gene was successfully constructed, recombinant adenovirus could suppress the expression of klf4 mRNA and KLF4 protein in HUVECs. It is concluded that the adenovirus vector for antisense klf4 gene has been constructed successfully, which provides the material basis for further studying the biologic function and potential application of klf4.

[Construction of nonsense-mutated eukaryotic expression vector of factor IX gene and its expression in COS-7 cells].

The purpose of this study was to construct 4 types of nonsense-mutated eukaryotic expression plasmids of fIX gene, using pcDNA3.1 plasmid containing fIX cDNA as template, and to identify, then to perform their expression in COS-7 cells. These stop mutants constructed by site-directed mutagenesis based on PCR, and further confirmed by DNA sequencing. COS-7 cells were transfected with either the wild-type or mutated fIX expression constructs, then the relative expression levels of fIX mRNA were detected by real time fluorescent quantitative PCR. The result showed that except the designed sites, there were no other nucleotide mutation in the sequences of four nonsense mutants. The results of real time PCR proved that the nonsense-mutated vectors can be effectively expressed in COS-7 cells. It is concluded that the nonsense-mutated eukaryotic expression vectors of fIX gene have been successfully constructed and can express in COS-7 cells, which provides the material basis for further researches on mechanism and treatment of FIX deficiency and the function defects caused by nonsense mutation.