[The Short-term Analysis of Overlapped Delta-shaped Anastomosis in Total Laparoscopic Transverse Colectomy]

Objective: The aim of this study was to explore the clinical safety, feasibility and short-term effect of overlapped delta-shaped anastomosis in total laparoscopic transverse colectomy. Methods: The records, which were based on China National Cancer Center, of 20 and 31 patients who underwent total laparoscopic transverse colectomy with overlapped delta-shaped anastomosis and laparoscopic-assisted transverse colectomy with conventional extracorporeal anastomosis, from March 2017 to May 2018 were reviewed retrospectively. Data regarding surgical outcomes, postoperative recovery, pathological outcomes and perioperative complications were collected and compared. Results: There was no difference between the two groups in overall operation time, anastomosis time and intraoperative blood loss (P>0.05), however, the length of incision was significantly shorter in overlapped delta-shaped group [(4.7±0.6) cm vs. (5.5±1.0) cm, P=0.002]. The time to ground activities, first flatus and postoperative hospitalization did not differ between the two groups (P>0.05). The postoperative visual analogue scale was lower in the overlapped delta-shaped group than the control group on postoperative day 1 (3.7±0.7 vs. 4.2±0.9, P=0.015) and postoperative day 3 (2.7±0.5 vs. 3.2±0.9, P=0.040). The perioperative complication rates were 10.0% and 12.9% in the overlapped delta-shaped group and the control group, respectively, and the difference was not significant (P=0.753). Conclusion: Compared to conventional extracorporeal anastomosis, total laparoscopic transverse colectomy with overlapped delta-shaped anastomosis was a safe and feasible procedure with satisfactory short-term effect, shorter incision and less postoperative pain.

Radio frequency measurement and tuning of a 13 MeV Alvarez-type drift tube linac for a compact pulsed hadron source

This paper describes the radio frequency (RF) measurement and tuning result of a 13 MeV Alvarez-type drift tube linac (DTL) for a compact pulsed hadron source (CPHS) at Tsinghua University. The design, machining, assembly, and alignment of the DTL are presented for integrity. The CPHS project consists of a high-current proton linac (13 MeV, 16 kW, peak current of 50 mA, 0.5 ms pulse width at 50 Hz), a neutron target station, a small-angle neutron scattering instrument, and a neutron imaging/radiology station. The linac contains an electron cyclotron resonance ion source, a low energy beam transport line, a four-vane radio frequency quadrupole (RFQ) accelerator, an Alvarez-type DTL, a high energy beam transport line, and a RF power supply and distributor. Construction on the CPHS started in June 2009, and the CPHS has provided 2000 h since 2013 to users with the neutrons produced by the 3 MeV proton beam from the radio frequency quadrupole bombarding on the beryllium target as an achievement of its mid-term objective. Presently, the tuning of the assembled DTL cavity has been completed successfully. The 4.3-m-long DTL consists of 40 accelerating cells, among which 39 full-length drift tubes (DTs) are suspended inside the cavity, and two half-length DTs are mounted inside the two end flanges of the cavity. Each DT contains a permanent magnet quadrupole. Thirteen post couplers and nine tuners are available for the tuning of the field. The relative error of the field after tuning is within ±1.6%, with a tilt sensitivity within ±33%/MHz in all cells. The beam energy will reach its designed value of 13 MeV after the DTL is installed in the beam line downstream the 3 MeV RFQ accelerator.

[The exploration of gene promoter methylation profiling in nasal polyp]

Objective:To explore the gene promoter methylation profiles of nasal polyp, and to analysis the promoter methylation differences between the nasal polyp and the normal nasal mucosa.Method:Total DNA of the nasal polyp tissues and normal nasal mucosa were extracted. After immunoprecipitation and whole genome amplification, the DNA was labeled with Cy3/5 and hybridized in NimbleGen hybridization chamber. For array hybridization, Roche Nimblegen CpG Promoter array was used. The slides were scanned using the Axon GenePix 4000B microarray scanner. The different genes were analyzed through pathway and verified by Real-time PCR.Result:3010 genes were found to have promoter hypermethylation in normal nasal mucosa or nasal polyp.2,62%(79/3010) of the genes had promoter hypermethylation in all the nasal polyps, which were negative in normal nasal mucosa.10.66%(321/3010) of the genes had promoter hypermethylation in normal nasal mucosa, which were negative in all the nasal polyps. Three pathways were found in the promoter hypermethylation of the nasal polyps. Fourteen pathways were found in the negative hypermethylation of the nasal polyps.Conclusion:Genes promoter methylation plays an important role in the development of nasal polyps, and the gene promoter methylation profiling may yield new some clues on the mechanism of nasal polyps.

[A Meta-analysis on the relations between short-term exposure to PM(2.5) and both mortality and related emergency visits in China]

Objective: To carry out a quantitative estimate that related to the effects of short-term exposure to PM(2.5) on all-cause mortality and emergency visits in China by using the systematic review and Meta-analysis. Methods: We selected all the studies published before March 2018 from China National Knowledge Infrastructure, Wanfang database, PubMed and EMBASE and data on relative risk (RR), excess risk (ER) and their 95%CIs: appeared in these papers were extracted. According to the differences in the size or direction (heterogeneity) of the results, we computed summary estimates of the effect values using a random-effect or fixed effect model. We also conducted the subgroup analysis and Meta-analysis to have assessed the selected studies for the evidence of study bias. Results: A total of 33 original studies, indexed in databases, were identified. Among those studies, 39 sets of data on mortality and 4 sets of data on emergency were valid to show that within the daily concentration range from 47.7 to 176.7 μg/m(3), for 10 μg/m(3) increases in PM(2.5) concentrations, it would increase the daily numbers of deaths by 0.49% (95%CI: 0.39%-0.59%) and 0.30% (95%CI: 0.10%-0.51%) for all-cause deaths and all-cause emergency-room visits, respectively. For subgroup analysis, the combined effect of PM(2.5) in causing short-term all-cause deaths in the northern areas (ER=0.42%, 95%CI: 0.30%-0.54%) seemed lower than that in the southern areas (ER=0.63%, 95%CI: 0.44%-0.82%). The combined effect of PM(2.5) concentration below 75 μg/m(3) (ER=0.50%, 95%CI: 0.37%-0.62%) was higher than that of PM(2.5) concentration ≥75 μg/m(3) (ER=0.39%, 95%CI: 0.26%-0.52%). Conclusion: Within the concentration range from 47.7 to 176.7 μg/m(3), short-term exposure to current level of PM(2.5) might increase both the all-cause daily mortality and daily emergency visits in China.

[The exploration of VEGF-B methylation in the nasal polyp]

Objective:The objective of this study is to investigate the methylation status of vascular endothelial cell growth factor B (VEGF-B) gene and to indentify the roles in pathogenesis,development and classification of nasal polyps.Method:The methylation status of VEGF-B gene of 28 nasal polyp tissues and 12 samples of inferior turbinate tissues were detected by methylationspecific-polymerase chain reaction (MS-PCR) and gene sequencing.Result:There was significant statistic diference between nasal polyp tissue group and control group (χ ²=4.096,P<0.05). The results of gene sequencing suggest that the VEGF-B gene promoter were hypomethylation status in the nasal polyps.Conclusion:Methylation status of VEGF-B promoter may play an important role in the pathogenetic mechanism of nasal polyps.

Redefining Humicola sensu stricto and related genera in the Chaetomiaceae

The traditional concept of the genus Humicola includes species that produce pigmented, thick-walled and single-celled spores laterally or terminally on hyphae or minimally differentiated conidiophores. More than 50 species have been described in the genus. Species commonly occur in soil, indoor environments, and compost habitats. The taxonomy of Humicola and morphologically similar genera is poorly understood in modern terms. Based on a four-locus phylogeny, the morphological concept of Humicola proved to be polyphyletic. The type of Humicola, H. fuscoatra, belongs to the Chaetomiaceae. In the Chaetomiaceae, species producing humicola-like thick-walled spores are distributed among four lineages: Humicola sensu stricto, Mycothermus, Staphylotrichum, and Trichocladium. In our revised concept of Humicola, asexual and sexually reproducing species both occur. The re-defined Humicola contains 24 species (seven new and thirteen new combinations), which are described and illustrated in this study. The species in this genus produce conidia that are lateral, intercalary or terminal on/in hyphae, and conidiophores are not formed or are minimally developed (micronematous). The ascospores of sexual Humicola species are limoniform to quadrangular in face view and bilaterally flattened with one apical germ pore. Seven species are accepted in Staphylotrichum (four new species, one new combination). Thick-walled conidia of Staphylotrichum species usually arise either from hyphae (micronematous) or from apically branched, seta-like conidiophores (macronematous). The sexual morph represented by Staphylotrichum longicolleum (= Chaetomium longicolleum) produces ascomata with long necks composed of a fused basal part of the terminal hairs, and ascospores that are broad limoniform to nearly globose, bilaterally flattened, with an apical germ pore. The Trichocladium lineage has a high morphological diversity in both asexual and sexual structures. Phylogenetic analysis revealed four subclades in this lineage. However, these subclades are genetically closely related, and no distinctive phenotypic characters are linked to any of them. Fourteen species are accepted in Trichocladium, including one new species, twelve new combinations. The type species of Gilmaniella, G. humicola, belongs to the polyphyletic family Lasiosphaeriaceae (Sordariales), but G. macrospora phylogenetically belongs to Trichocladium. The thermophilic genus Mycothermus and the type species My. thermophilum are validated, and one new Mycothermus species is described. Phylogenetic analyses show that Remersonia, another thermophilic genus, is sister to Mycothermus and two species are known, including one new species. Thermomyces verrucosus produces humicola-like conidia and is transferred to Botryotrichum based on phylogenetic affinities. This study is a first attempt to establish an inclusive modern classification of Humicola and humicola-like genera of the Chaetomiaceae. More research is needed to determine the phylogenetic relationships of “humicola”-like species outside the Chaetomiaceae.

Control energy of complex networks towards distinct mixture states

Controlling complex networked systems is a real-world puzzle that remains largely unsolved. Despite recent progress in understanding the structural characteristics of network control energy, target state and system dynamics have not been explored. We examine how varying the final state mixture affects the control energy of canonical and conformity-incorporated dynamical systems. We find that the control energy required to drive a network to an identical final state is lower than that required to arrive a non-identical final state. We also demonstrate that it is easier to achieve full control in a conformity-based dynamical network. Finally we determine the optimal control strategy in terms of the network hierarchical structure. Our work offers a realistic understanding of the control energy within the final state mixture and sheds light on controlling complex systems.

[HCV infection status and related risk factors in drug users under HIV sentinel surveillance in Henan province, 2011-2015]

OBJECTIVE

To understand the hepatitis C virus infection status and related risk factors in drug users in Henan province during 2011-2015 and provide scientific evidence for the development of HCV infection prevention and control measures.

METHODS

Cross-sectional questionnaire surveys were conducted among the drug users and blood samples were taken from them for HCV antibody detection during HIV sentinel surveillance period in Henan province from April to June during 2011-2015.

RESULTS

The HCV infection rate in drug users increased from 3.70% in 2011 to 6.54% in 2015 (trend χ(2)=25.93, P<0.01). Multivariate analysis indicated that HCV infection related risk factors included age older (OR=1.23, 95% CI: 1.13-1.35, P=0.00), place of domicile (OR=3.45, 95%CI: 2.59-4.60, P=0.00), traditional drug user or mixed drug user (OR=1.46, 95%CI: 1.10-1.93, P=0.01; OR=1.82, 95%CI: 1.18-2.81, P=0.01), injecting drug user (OR=2.88, 95%CI: 2.45-3.39, P=0.00), commercial sex behavior in recent one year (OR=1.44, 95%CI: 1.20-1.72, P=0.00) and drug user in compulsory drug rehabilitation or those receiving methadone maintenance treatment (OR=1.79, 95% CI: 1.28-2.50, P=0.00; OR=1.74, 95% CI: 1.17-2.58, P=0.01).

CONCLUSION

The HCV infection rate in drug users was higher in Henan and increased rapidly with years. In order to control HCV spread, it is necessary to strengthen the management of drug users and take effective intervention measures.

Diversity and taxonomy of Chaetomium and chaetomium-like fungi from indoor environments

During a study of indoor fungi, 145 isolates belonging to Chaetomiaceae were cultured from air, swab and dust samples from 19 countries. Based on the phylogenetic analyses of DNA-directed RNA polymerase II second largest subunit (rpb2), β-tubulin (tub2), ITS and 28S large subunit (LSU) nrDNA sequences, together with morphological comparisons with related genera and species, 30 indoor taxa are recognised, of which 22 represent known species, seven are described as new, and one remains to be identified to species level. In our collection, 69 % of the indoor isolates with six species cluster with members of the Chaetomium globosum species complex, representing Chaetomium sensu stricto. The other indoor species fall into nine lineages that are separated from each other with several known chaetomiaceous genera occurring among them. No generic names are available for five of those lineages, and the following new genera are introduced here: Amesia with three indoor species, Arcopilus with one indoor species, Collariella with four indoor species, Dichotomopilus with seven indoor species and Ovatospora with two indoor species. The generic concept of Botryotrichum is expanded to include Emilmuelleria and the chaetomium-like species B. muromum (= Ch. murorum) in which two indoor species are included. The generic concept of Subramaniula is expanded to include several chaetomium-like taxa as well as one indoor species. Humicola is recognised as a distinct genus including two indoor taxa. According to this study, Ch. globosum is the most abundant Chaetomiaceae indoor species (74/145), followed by Ch. cochliodes (17/145), Ch. elatum (6/145) and B. piluliferum (5/145). The morphological diversity of indoor Chaetomiaceae as well as the morphological characteristics of the new genera are described and illustrated. This taxonomic study redefines the generic concept of Chaetomium and provides new insight into the phylogenetic relationships among different genera within Chaetomiaceae.

Genetic variability of Myzus persicae nicotianae densovirus based on partial NS and VP gene sequences

We previously described a novel densovirus [Myzus persicae nicotianae densovirus (MpnDV)] infecting M. persicae nicotianae (Hemiptera: Aphididae) with 34% prevalence. This single-stranded DNA virus has a 5480-nucleotide ambisense genome and belongs to the Densovirinae subfamily within the family Parvoviridae. In the present study, we estimated the genetic diversity of MpnDV using partial nonstructural protein (NS) and capsid protein (VP) gene sequences from 10 locations in China. First, we identified MpnDV-positive samples by amplifying a 445-bp fragment with primers MpDVF/MpDVR. Subsequently, we amplified and sequenced COI genes with primers MpCOIF/ MpCOIR, and partial NS and VP sequences with primers MpnDVF1/MpnDVR1. The respective 655-, 1461-, and 423-bp COI, NS, and VP fragments were used to analyze the genetic diversity of MpnDV using MEGA 6.0 and DnaSP 5.0. The high level of identity shared by all COI sequences (>99%) suggested that the aphids sampled were of the same species, and indicated population homogeneity across the 10 locations investigated. The nucleotide diversity of MpnDV sequences (0.0020 ± 0.0025) was significantly higher than that of the COI genes (0.0002 ± 0.0005). The pairwise fixation index for MpnDV was 0.832, and the total gene flow was 0.05. Phylogenetic analysis revealed that the MpnDV haplotypes clustered according to geographical location, except for those from the Liaoning and Shanxi provinces. In conclusion, MpnDV demonstrated a low level of gene flow and high genetic diversity, suggesting that it is vertically transmitted, and implying that endosymbiotic viruses could be used as markers in studies of insect population genetics.

[Effect of autophagy inhibitor combined with EGFR inhibitor on triple-negative breast cancer MDA-MB-468 and MDA-MB-231 cells]

OBJECTIVE

To investigate the effect of combined administration of autophagy inhibitor 3-methyladenine/bafilomycin A1 and EGFR inhibitor gefitinib on triple-negative breast cancer MDA-MB-468, MDA-MB-231 cells and estrogen receptor-positive MCF-7 cells.

METHODS

All the cells were treated with 3-methyladenine/bafilomycin A1 and/or gefitinib. The effect of autophagy inhibitor and gefitinib on the cell growth was evaluated by MTT assay. Cell apoptosis was detected by flow cytometry. Western blot analysis was used to determine the alteration of autophagy-related protein (such as LC3) and apoptosis-related proteins (such as caspase-3 and caspase-9).

RESULTS

MTT assay showed that the IC50 in the GE+ 3-MA and GE+ BAF groups were (4.1±0.2) μmol/L and (3.8±0.3) μmol/L, significantly lower than that of the gefitinib alone group [(7.0±0.2) μmol/L] in MDA-MB-468 cells (P<0.05). Similarly, the IC50 in the GE+ 3-MA and GE+ BAF groups were (9.7±0.1) μmol/L and (7.7±0.2) μmol/L, significantly lower than that of the gefitinib alone group [(14.7±0.1) μmol/L]in MDA-MB231 cells (P<0.05). The flow cytometry assay revealed that the apoptosis rates of MDA-MB-468 cells in GE, GE+ 3-MA and GE+ BAF groups were (12.43±3.18)%, (23.37±2.71)% and (18.71±2.81)%, respectively. The apoptosis rates of MDA-MB-231 cells of the GE, GE+ 3-MA and GE+ BAF groups were (12.15±1.82)%, (16.94±2.19)% and (33.83±5.92) %, significantly higher than that of the gefitinib alone group (All P<0.05). The apoptosis rates of the MCF-7 cells were not changed significantly among the three groups (P>0.05). Western blot data showed that the expression levels of LC3 and p-Akt were decreased in the combined groups than that of the gefitinib alone group, while the p-PTEN, caspase-3 and caspase-9 were increased.

CONCLUSIONS

Autophagy inhibitor may enhance the sensitivity to gefitinib in MDA-MB-468 and MDA-MB-231 cells by activation of the PTEN/P13K/Akt pathway. Apoptosis in MDA-MB-468 and MDA-MB-231 cells might be enhanced by the combination treatment through caspase cascade.

Apoptosis is related to imbalance of Th1/Th2-type cytokine in peripheral blood mononuclear cells of patients with chronic hepatitis B

KEYWORDS

peripheral blood mononuclear cells; apoptosis; cytokine; hepatitis B virus.

Effect of correlations on controllability transition in network control

The network control problem has recently attracted an increasing amount of attention, owing to concerns including the avoidance of cascading failures of power-grids and the management of ecological networks. It has been proven that numerical control can be achieved if the number of control inputs exceeds a certain transition point. In the present study, we investigate the effect of degree correlation on the numerical controllability in networks whose topological structures are reconstructed from both real and modeling systems, and we find that the transition point of the number of control inputs depends strongly on the degree correlation in both undirected and directed networks with moderately sparse links. More interestingly, the effect of the degree correlation on the transition point cannot be observed in dense networks for numerical controllability, which contrasts with the corresponding result for structural controllability. In particular, for directed random networks and scale-free networks, the influence of the degree correlation is determined by the types of correlations. Our approach provides an understanding of control problems in complex sparse networks.

Xpert MTB/RIF Assay for Pulmonary Tuberculosis and Rifampicin Resistance in Children: a Meta-Analysis

BACKGROUND

The Xpert MTB/RIF assay has been recommended by WHO to replace conventional microscopy, culture, and drug resistance tests. It simultaneously detects both Mycobacterium tuberculosis infection (TB) and resistance to rifampicin (RIF) within two hours. The objective was to review the available research studies on the accuracy of the Xpert MTB/RIF assay for diagnosing pulmonary TB and RIF-resistance in children.

METHODS

A comprehensive search of Pubmed and Embase was performed up to October 28, 2014. We identified published articles estimating the diagnostic accuracy of the Xpert MTB/RIF assay in children with or without HIV using culture or culture plus clinical TB as standard reference. QUADAS-2 tool was used to evaluate the quality of the studies. A summary estimation for sensitivity, specificity, diagnostic odds ratios (DOR), and the area under the summary ROC curve (AUC) was performed. Meta-analysis was used to establish the overall accuracy.

RESULTS

11 diagnostic studies with 3801 patients were included in the systematic review. The overall analysis revealed a moderate sensitivity and high specificity of 65% (95% CI: 61 - 69%) and 99% (95% CI: 98 - 99%), respectively, and a pooled diagnostic odds ratio of 164.09 (95% CI: 111.89 - 240.64). The AUC value was found to be 0.94. The pooled sensitivity and specificity for paediatric rifampicin resistance were 94.0% (95% CI: 80.0 - 93.0%) and 99.0% (95% CI: 95.0 - 98.0%), respectively. Hence, the Xpert MTB/RIF assay has good diagnostic and rifampicin performance for paediatric pulmonary tuberculosis.

CONCLUSIONS

The Xpert MTB/RIF is sensitive and specific for diagnosing paediatric pulmonary TB. It is also effective in detecting rifamnicin resistance. It can, therefore, be used as an initial diagnostic tool.

Diagnostic value of transvaginal color Doppler ultrasound on endometrial lesions

OBJECTIVE

To discuss the diagnostic value of transvaginal color Doppler ultrasound on endometrial lesions.

MATERIALS AND METHODS

The study included 126 cases diagnosed with endometrial lesions by transvaginal color Doppler ultrasound that were examined by hysteroscopy, biopsy, and curettage pathology, and compared with pathology.

RESULTS

The transvaginal color Doppler ultrasound diagnosis corresponded to 92.6% (117 of 126 cases) of the pathology diagnosis.

CONCLUSIONS

Transvaginal color Doppler ultrasound has important diagnostic value in the case of endometrial lesions, has a high rate of detection and diagnostic on endometrial lesions, and is the best method for diagnosis of endometrial lesions.

Analysis of drug-resistant gene detection of blaOXA-like genes from Acinetobacter baumannii

Our study determines the resistance gene profile of a set of Acinetobacter baumannii hospital isolates. A. baumannii is responsible for nosocomial outbreaks and sporadic infections. We extracted and PCR amplified bacterial DNA isolated from patients with ages below 60 years (23.36%) and above 60 years (76.64%). Most of the patients were admitted in the ICU (36.13%) and pneumology departments (28.47%). Of 164 isolated strains, 16 (9.75%) contained OXA-51, 8 (4.88%) contained OXA-58, and 140 (85.37%) contained both OXA-51 and OXA-23. Additionally, 8 (7.41%) strains containing OXA-58 and 100 (92.59%) strains containing both OXA-51 and OXA-23 showed multidrug-resistance. Drug resistance rates of A. baumannii to amikacin, tobramycin-levofloxacin, and cotrimoxazole were above 90%, while drug resistance rates to ampicillin, cefotetan, cefazolin, cefoperazone, and nitrofurantoin were 100%. In conclusion, we found that isolated strains containing OXA-51 and OXA-23 were more likely to be resistant or have decreased sensitivity to carbapenems.

Population genetic structure of Myzus persicae nicotianae (Hemiptera: Aphididae) in China by microsatellite analysis

The tobacco aphid, Myzus persicae nicotianae (Hemiptera: Aphididae), is an important agricultural pest that feeds on host plants and transmits plant viruses in China. To effectively control this pest, we investigated the genetic variation and genetic structure of 54 populations of tobacco aphids collected in China, using five microsatellite loci. An average of 7 alleles with effective number ranging from 1.5 to 6.6 was detected using these five loci, and the average polymorphic information content (PIC) was 0.652, suggesting that the five selected microsatellite loci were polymorphic and suitable for the study of population genetics. The expected heterozygosities in the populations studied ranged from 0.128 and 0.653, with an average value of 0.464. However, the observed heterozygosities ranged from 0.250 and 0.942 (average = 0.735), revealing a high genetic variability and heterozygosity excess in the Chinese tobacco aphid populations. The global fixation index (F(ST)) and mean gene flow (N(m)) were 0.34 (P < 0.0001) and 0.50, respectively, suggesting the high genetic differentiation among Chinese populations. The 54 populations of tobacco aphids were classified into two groups. The populations did not cluster geographically, as populations from the same provinces were usually present in different clusters. This was also confirmed by the Mantel test, which showed no significant correlation between the genetic distance and geographical distance or altitude. Long distance migration might be responsible for the lack of distance-related isolation.

Photoluminescence from voids created by femtosecond-laser pulses inside cubic-BN

Photoluminescence (PL) from femtosecond-laser-modified regions inside cubic-boron nitride (c-BN) was measured under UV and visible light excitation. Bright PL at the red spectral range was observed, with a typical excited state lifetime of ∼4  ns. Sharp emission lines are consistent with PL of intrinsic vibronic defects linked to the nitrogen vacancy formation (via Frenkel pair) observed earlier in high-energy electron-irradiated and ion-implanted c-BN. These, formerly known as the radiation centers, RC1, RC2, and RC3, have been identified at the locus of the voids formed by a single femtosecond-laser pulse. The method is promising to engineer color centers in c-BN for photonic applications.

Effect of Bcl-2-siRNA on proliferation and apoptosis of pediatric acute B lymphoblastic leukemia (A-BLL) cells

This study analyzed the effect of small interfering RNA specific for the Bcl-2 gene (siRNA Bcl-2) on the proliferation and chemotherapeutic sensitivity of pediatric A-BLL cells. Marrow samples were obtained from sixty newly-diagnosed A-BLL pediatric patients. The Bcl-2 mRNA expression in these samples was quantified by real time polymerase chain reaction. The Bcl-2 mRNA re-expression was analyzed by RNA interference using Bcl-2-siRNA. Cellular proliferation was detected using the MTT (Thiazolyl Blue Tetrazolium Bromide) assay. The cell apoptosis was quantified by flow cytometry. The Bcl-2 mRNA expression was significantly higher in the drug-resistance group than in the chemotherapy sensitivity group prior to chemotherapy (P < 0.05). In addition, the Bcl-2 mRNA expression in the chemotherapy sensitivity group was significantly higher before chemotherapy than that after chemotherapy (P < 0.05). The Bcl-2 mRNA expression significantly decreased in the leukemic cells of the Bcl-2-siRNA transfection group. We observed statistically significant differences in the relative mRNA expression levels among the Bcl-2-siRNA transfection, blank control, liposome empty transfection, and unrelated sequence oligonucleotide groups (P < 0.05). The rate of apoptosis in pediatric A-BLL leukemic cells was observed to increase significantly after transfection with Bcl-2-siRNA compared to the control, liposome empty transfection, and unrelated sequence oligonucleotide groups (P < 0.05). Therefore, we concluded that Bcl-2-siRNA can successfully inhibit the multiplicative capacity of A-BLL leukemic cells and promote apoptosis.

Expression differences in TEL-AML1 fusion gene in leukemia glucocorticoid-sensitive and -resistant cell lines

We investigated the expression differences of the TEL-AML1 fusion gene in a leukemia glucocorticoid (GC)-sensitive cell line (CEM) and a GC-resistant cell line (Jurkat). Changes in TEL-AML1 expression before and after GC exposure were analyzed. Expression of GC-sensitive and GC-resistant leukemia cells following initial diagnosis and during treatment was simulated. Leukemia cells were divided into a GC-unexposed or a GC-exposed group. A methyl thiazolyl tetrazolium assay was used to detect cell proliferation inhibition, flow cytometry was used to observe cell apoptosis, reverse transcription-polymerase chain reaction was used to detect the mRNA expression of TEL-AML1 before and after exposure, and western blotting was used to analyze protein levels of TEL-AML1 before and after exposure. Inhibitory concentrations of 50% of cells in the Jurkat and CEM cells at 24 h were 382 and 9 mM, respectively, and at 48 h they were 216 and 2 mM. The proliferation inhibition effect of dexamethasone sodium phosphate on Jurkat cells was much lower than that on CEM cells. Jurkat cells showed obvious apoptosis after exposure to 100 mM dexamethasone sodium phosphate for 48 h. In the exposed group, Jurkat cells showed higher TEL-AML1 expression than did CEM cells (P < 0.05). In the unexposed group, TEL-AML1 gene expression in Jurkat cells was not affected by GC exposure (P > 0.05), while the CEM cells presented significant differences before and after exposure (P < 0.05). Sustained high expression of TEL-AML1 participated in and maintained the occurrence of GC resistance. Inhibition of TEL-AML1 may provide a new therapeutic approach to reverse GC resistance.