PTPRC Overexpression Predicts Poor Prognosis and Correlates with Immune Cell Infiltration in Pediatric Acute Myeloid Leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is a molecularly heterogeneous disease that accounts for approximately 25% of childhood leukemia cases. In this study, we aimed to identify survival-associated genes in pediatric AML patients and investigate potential immunotherapy targets. METHODS: After retrieving and processing the data from Gene Expression Omnibus (GEO) web resource, we determined hub genes in AML. Bioinformatics technology was applied to identify key genes and perform functional analysis. Finally, we investigated the correlation between the key gene and the infiltration levels of tumor-infiltrating immune cells. RESULTS: High protein tyrosine phosphatase receptor-type C (PTPRC) expression was associated with worse overall survival rate (p < 0.001) in 287 pediatric AML patients. The results of risk subgroup analyses were similar in the high-risk and low-risk groups (p = 0.007; p = 0.013). Meanwhile, high expression of PTPRC was an independent adverse prognostic factor for overall survival (p = 0.04). Moreover, the results of immune infiltration assessment demonstrated that the expression level of PTPRC was significantly correlated with the infiltration level of activated dendritic cells (p < 0.001). CONCLUSIONS: Overexpression of PTPRC indicates poor prognosis, and its expression level is correlated with the infiltration level of activated dendritic cells. PTPRC could be a promising immunotherapy target for pediatric AML.

Antibody Aggregate Removal Using a Mixed-Mode Chromatography Resin.

In monoclonal antibody (mAb) production, aggregates represent a major class of product-related impurities that needs to be removed by the downstream process. Protein A chromatography is generally less effective at removing antibody aggregates under typical conditions, and in most cases aggregate removal relies on a subsequent polishing chromatography. Here we describe a procedure for effective removal of antibody aggregates using the mixed-mode chromatography resin Capto MMC ImpRes. Clearance of aggregates was confirmed by analytical size-exclusion chromatography (SEC) and native gel electrophoresis.

A potential downstream platform approach for WuXiBody-based IgG-like bispecific antibodies.

WuXiBody is a novel bispecific antibody (bsAb) platform developed by WuXi Biologics. It enables almost any monoclonal antibody (mAb) sequence pair to be assembled into a bispecific construct. BsAbs based on WuXiBody can adopt either asymmetric or symmetric format. WuXiBody's unique design not only ensures desired chain pairing but also facilitates removal of potential product-related impurities. In this work, demonstrated with four WuXiBody-based bsAbs (two asymmetric and two symmetric ones), we showed that Protein A followed by anion exchange (AEX) and mixed-mode chromatography (i.e., Capto MMC ImpRes or Capto adhere ImpRes) can be a potential platform approach for WuXiBody purification.

Autokinase Activity of Casein Kinase 1 δ/ε Governs the Period of Mammalian Circadian Rhythms.

Circadian rhythms exist in nearly all organisms. In mammals, transcriptional and translational feedback loops (TTFLs) are believed to underlie the mechanism of the circadian clock. Casein kinase 1δ/ε (CK1δ/ε) are key kinases that phosphorylate clock components such as PER proteins, determining the pace of the clock. Most previous studies of the biochemical properties of the key kinases CK1ε and CK1δ in vitro have focused on the properties of the catalytic domains from which the autoinhibitory C-terminus has been deleted (ΔC); those studies ignored the significance of self-inhibition by autophosphorylation. By comparing the properties of the catalytic domain of CK1δ/ε with the full-length kinase that can undergo autoinhibition, we found that recombinant full-length CK1 showed a sequential autophosphorylation process that induces conformational changes to affect the overall kinase activity. Furthermore, a direct relationship between the period change and the autokinase activity among CK1δ, CK1ε, and CK1ε-R178C was observed. These data implicate the autophosphorylation activity of CK1δ and CK1ε kinases in setting the pace of mammalian circadian rhythms and indicate that the circadian period can be modulated by tuning the autophosphorylation rates of CK1δ/ε.

Monitoring removal of hole-hole homodimer by analytical hydrophobic interaction chromatography in purifying a bispecific antibody.

Despite the use of knobs-into-holes (KiH) strategy to promote heterodimerization in recombinant production of bispecific antibody (bsAb), homodimer (especially the hole-hole homodimer) can still be generated in small amount. This by-product needs to be removed by downstream process. However, as homodimer and the target bsAb are usually very close in size, these two species may not be readily differentiated using size-exclusion chromatography-high performance liquid chromatography (SEC-HPLC). Thus, method other than SEC-HPLC needs to be developed to monitor removal of this by-product. Here, through a case study we demonstrate that analytical hydrophobic interaction chromatography (HIC) is a powerful tool for quantitatively monitoring removal of hole-hole homodimer in bsAb purification.

Transcatheter perimembranous ventricular septal defect closure under transthoracic echocardiographic guidance without fluoroscopy.

BACKGROUND: Transcatheter device closure has become an alternative therapy for ventricular septal defect (VSD). This study aimed to investigate the feasibility and safety of transcatheter perimembranous VSD (pm-VSD) closure under transthoracic echocardiography (TTE) guidance alone. METHODS: Between October 2012 and July 2016, 118 patients with pm-VSD underwent an attempt of transcatheter device closure for pm-VSD through the femoral artery under TTE guidance alone. Patients were followed-up at 1, 3, 6, and 12 months after the procedure and yearly after discharge. RESULTS: The mean age was 11.7±12.5 years (range, 1.0-53.0 years) and the mean body weight was 32.2±21.6 kg (range, 11.5-102.0 kg). The mean diameter of the VSD was 4.0±1.1 mm (range, 3.0-8.0 mm). Transcatheter device closure under TTE guidance alone was successful in 111 patients. The average procedural time was 44.9±7.3 minutes (range, 29.0-65.0 minutes). All 111 patients were followed-up for 3.4±2.3 years. At the last follow-up, two patients had a residual shunt smaller than 2 mm, seven patients had right bundle branch block (RBBB) including one patient with complete RBBB, six patients had mild or less tricuspid regurgitation, and two patients still had trivial aortic regurgitation including one patient that had it before the procedure. Occluder malposition, complete atrioventricular block, or other complications were not observed. CONCLUSIONS: Transcatheter pm-VSD closure can be successfully performed under TTE guidance alone with outcomes similar to those achieved with fluoroscopic guidance in selected patients with weight more than 10 kg and VSD smaller than 8 mm. However, long-term follow-up in a large number of patients would be necessary.

A Novel Wire Is Effective for Echo-Guiding Percutaneous Atrial Septal Defect Closure: A Preclinical Study.

Objective: To assess the effectiveness of a novel ultrasound wire for echo-guiding percutaneous atrial septal defect (ASD) closure in a sheep model. Methods: After right lateral thoracotomy, ASDs were created in 20 sheep by transseptal needle puncture followed by balloon dilatation. Animals were evenly randomized into 2 groups to undergo ASD closure using echography as the only imaging tool with either COOK wire (control group) or new ultrasound wire (study group). The total procedural time, passing time (time needed for the guide wire to enter the left atrium), frequency of delivery sheath dropping into the right atrium, frequency of arrhythmias, and 1-week rate of complications were compared between the two groups. Results: All animals survived defect creation procedures uneventfully. ASD devices were successfully implanted in all sheep. Compared with the control group, the study group had significantly (P < 0.05) lower mean procedure time (15.36 ± 4.86 versus 25.82 ± 7.85 min), lower mean passing time (2.69 ± 0.82 versus 5.58 ± 3.34 min), lower frequency of the guide wire dropping into the right atrium (0% versus 40%), and lower frequency of atrial (4.41 ± 2.61 versus 9.60 ± 3.68) or ventricular premature contractions (0.75 ± 0.36 versus 1.34 ± 0.68), respectively, without serious complications up to one week. Conclusion: The novel ultrasound specialized guide wire was effective in echo-guiding percutaneous ASD closure.

Feasibility and effectiveness of percutaneous balloon mitral valvuloplasty under echocardiographic guidance only.

OBJECTIVE: Percutaneous balloon mitral valvuloplasty (PBMV) is the treatment of choice in patients with isolated mitral stenosis. This study aimed to assess the feasibility of PBMV under echocardiography guidance only of isolated mitral stenosis (MS). METHODS: From October 2016 to Dec 2017, 20 consecutive patients with severe MS underwent PBMV with echocardiography as the only imaging modality at a single center. Outpatient follow-up including chest radiography, electrocardiography, and transthoracic echocardiography was conducted at 1, 3,6, and 12 months after the procedure. RESULTS: All 20 patients successfully underwent PBMV under echocardiography guidance without radiation and contrast agent. Among them, 2 patients were pregnant, 5 had chronic renal failure, and 1 had history of allergy to contrast. Mitral transvalvular pressure gradient measured at catheterization dropped from 13.35 ± 2.85 mm Hg to 5.10 ± 1.17 mm Hg (P < .01). Mitral valve area increased from 0.82 ± 0.10 cm2 pre-PBMV to 1.88 ± 0.24 cm2 post-PBMV (P < .01). Mean balloon diameter was 26.63 ± 0.93 mm. Mild mitral regurgitation developed in 6 patients. Mean follow-up duration was 6.27 ± 3.12 months. At last follow-up, mitral valve area remained high (1.71 ± 0.14 cm2 ) and mean transmitral pressure gradient low (6.07 ± 1.03 mm Hg). No pericardial effusion or peripheral vascular complications occurred. CONCLUSION: In this small experience, PBMV could be successfully performed under only echocardiography guidance and appeared safe and effective while avoiding radiation and contrast agent use.

Hybrid Balloon Valvuloplasty for the Treatment of Severe Congenital Aortic Valve Stenosis in Infants.

BACKGROUND: Surgical or percutaneous interventional treatment of severe congenital aortic valve stenosis (CAS) in early infancy remains challenging. This single-center, retrospective study analyzed midterm outcomes of a hybrid balloon valvuloplasty procedure through the ascending aorta by way of median sternotomy, including cases with improved technique. METHODS: Included were 45 consecutive infants (aged <90 days) with CAS and selected for biventricular repair who underwent hybrid balloon valvuloplasty in a hybrid or ordinary operating room from October 2010 to March 2016. Patients were assessed at 1, 3, 6, and 12 months and yearly thereafter. RESULTS: Hybrid balloon valvuloplasty was successful in all patients, with the last 8 treated in an ordinary operating room under only echocardiography guidance with a new sheath. Thirty-two patients were successfully rescued from low heart rate or left ventricular systolic dysfunction, or both, by cardiac massage under direct visualization; none required cardiopulmonary bypass. The degree of new aortic insufficiency was mild in 7 patients and changed from mild to moderate in 1 patient. Aortic valve pressure gradient decreased from 70.6 ± 17.5 mm Hg preoperatively to 15.2 ± 4.2 mm Hg immediately postoperatively (p < 0.001). Fluoroscopy time was 4.8 ± 2.3 minutes. At a median of 32.1 months (range, 1 to 68 months) follow-up, all patients were alive and healthy. Aortic valve pressure gradient remained low (19.1 ± 5.2 mm Hg). Left ventricular ejection fraction increased from 0.515 ± 0.134 (range, 0.21 to 0.70) preoperatively to 0.633 ± 0.035 (range, 0.58 to 0.75; p < 0.001). No aortic insufficiency developed, and no patient required reintervention. CONCLUSIONS: For infants with severe CAS, hybrid balloon valvuloplasty through the ascending aorta by way of a median sternotomy appears efficacious and safe up to midterm follow-up.

Percutaneous Closure of Atrial Septal Defects Under Transthoracic Echocardiography Guidance Without Fluoroscopy or Intubation in Children.

OBJECTIVE: Demonstrate the benefits of percutaneous atrial septal defect (ASD) closure under guidance of transthoracic echocardiography (TTE) without fluoroscopy. METHODS: From February 2013 to April 2014, 127 consecutive patients with an isolated type II ASD were recruited to undergo percutaneous closure under either TTE (n = 60, TTE group) or TEE (n = 67, TEE group) guidance. The TTE group received local anesthesia or sedation with propofol, and the TEE group received general anesthesia with endotracheal intubation. Follow-up examinations were performed for both groups at 1 month, 3 months, 6 months, and 1 year after discharge and annually thereafter. RESULTS: The TTE group had a significantly shorter procedure time and respirator ventilation duration than the TEE group. The dose of propofol required, the cost, and the pharyngeal complication rate were significantly lower in the TTE group than in the TEE group. The median follow-up of 11.6 months was uneventful in all patients. CONCLUSIONS: Percutaneous ASD closure with TTE guidance as the only imaging tool avoids fluoroscopy, endotracheal intubation, and probe insertion and is associated with a satisfactory procedural success rate and lower costs. This procedure is a safe and reliable treatment for ASD.

[Safety and efficacy of percutaneous patent ductus arteriosus closure solely under thoracic echocardiography guidance].

OBJECTIVE: To avoid the radiation injuries and use of contrast agent, we assessed the safety and efficacy of percutaneous patent ductus arteriosus closure solely under thoracic echocardiography guidance. METHODS: From June 2013 to June 2014, thirty patients (mean age: (6.3 ± 2.5) years, mean body weight:(22.5 ± 7.3) kg) with pure patent ductus arteriosus were continuously included in this study. The mean diameter of patent ductus arteriosus was (3.8 ± 0.9) mm. Patients were all treated by percutaneous patent ductus arteriosus closure via right femoral artery solely under thoracic echocardiography guidance. The efficacy of the procedure was evaluated by thoracic echocardiography. Follow-up was performed at one month after procedure. RESULTS: All 30 cases were successfully treated with percutaneous patent ductus arteriosus closure solely under thracic echocardiography guidance. The procedural time was (32.8 ± 5.7) minutes. The mean diameter of Amplatzer ADO II was (4.9 ± 1.0) mm. Postoperative trivial residual shunt occurred in six patients immediately after the procedure. All patients survived without peripheral vascular injury or complications such as cardiac perforation. Hospitalization time was (3.4 ± 0.7) days. At one-month follow-up, no complications such as residual shunt or pericardial effusion were observed. CONCLUSION: Echocardiography guided percutaneous patent ductus arteriosus closure by femoral artery approach is safe and effective, and can avoid X-ray and the use of contrast agents.

Comparative study of bacteriological culture and real-time fluorescence quantitative PCR (RT-PCR) and multiplex PCR-based reverse line blot (mPCR/RLB) hybridization assay in the diagnosis of bacterial neonatal meningitis.

BACKGROUND: Bacterial meningitis is more common in the neonatal period than any other time in life; however, it is still a challenge for the evidence based diagnosis. Strategy for identification of neonatal bacterial meningitis pathogens is presented by evaluating three different available methods to establish evidence-based diagnosis for neonatal bacterial meningitis. METHODS: The cerebrospinal fluid samples from 56 neonates diagnosed as bacterial meningitis in 2009 in Beijing Children's Hospital were analyzed in the study. Two PCR based molecular assays, real-time fluorescence quantitative PCR (RT-PCR) and multiplex PCR based-reverse line blot hybridization (mPCR/RLB), were used to assess 7 common neonatal meningitis bacterial pathongens, including Escherichia coli, Staphylococcus aureus, Listerisa monocytogenes, Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, and Streptococcus agalactiae. The findings in examinations of two assays were compared with the results obtained bacterial culture tests. RESULTS: Bacterial meningitis was identified in five cases (9%) by CSF cultures, 25 (45%) by RT-PCR and 16 (29%) by mPCR/RLB. One strain of S. epidermidis and one of E. faecalis were identified using mPCR/RLB but not by RT-PCR. In contrast, cultures identified one strain of S. pneumoniae which was missed by both PCR assays. Overall, the bacterial pathogens in 28 cases were identified with these three methods. Both RT-PCR and mPCR/RLB assays were more sensitive than bacterial culture, (p < 0.05). CONCLUSION: Our study confirmed that both RT-PCR and mPCR/RLB assays have better sensitivity than bacterial culture. They are capable of detecting the pathogens in CSF samples with negative culture results.

[Safety and efficacy of percutaneous transcatheter closure of atrial septal defect under transesophageal echocardiography guidance in children].

OBJECTIVE: To assess the safety and effectiveness of percutaneous transcatheter closure of atrial septal defect (ASD) under transesophageal echocardiography (TEE) guidance in children. METHODS: The study included 20 cases of patients with ASD. The patients were (4.2 ± 1.2) years old and the mean body weights were (18.2 ± 4.2) kg. The diameter of ASD before closure was (13.4 ± 3.3) mm . All procedures were guided under TEE. Procedure success was evaluated by TEE immediately after procedure. RESULTS: Closure devices were successfully implanted in all 20 patients under TEE guidance. The diameter of closure devices was 14-26 mm. There were no procedure related complications. The ventilation time was (2.9 ± 0.8)h and the hospitalization time was (3.2 ± 0.7) days. CONCLUSION: TEE guided percutaneous transcatheter closure is safe and effective for patients with ASD and avoids the radiation damages.

Tetramethylpyrazine potentiates arsenic trioxide activity against HL-60 cell lines

The objective of this study was to evaluate the effects of tetramethylpyrazine (TMP) in combination with arsenic trioxide (As2O3) on the proliferation and differentiation of HL-60 cells. The HL-60 cells were treated with 300 µg/mL TMP, 0.5 µM As2O3, and 300 µg/mL TMP combined with 0.5 µM As2O3, respectively. The proliferative inhibition rates were determined with MTT. Differentiation was detected by the nitroblue tetrazolium (NBT) reduction test, Wright’s staining and the distribution of CD11b and CD14. Flow cytometry was used to analyze cell cycle distribution. RT-PCR and Western blot assays were employed to detect the expressions of c-myc, p27, CDK2, and cyclin E1. Combination treatment had synergistic effects on the proliferative inhibition rates. The rates were increased gradually after the combination treatment, much higher than those treated with the corresponding concentration of As2O3 alone. The cells exhibited characteristics of mature granulocytes and a higher NBT-reducing ability, being a 2.6-fold increase in the rate of NBT-positive ratio of HL-60 cells within the As2O3 treatment versus almost a 13-fold increase in the TMP + As2O3 group. Cells treated with both TMP and As2O3 expressed far more CD11b antigens, almost 2-fold compared with the control group. Small doses of TMP potentiate As2O3-induced differentiation of HL-60 cells, possibly by regulating the expression and activity of G0/G1 phase-arresting molecules. Combination treatment of TMP with As2O3 has significant synergistic effects on the proliferative inhibition of HL-60 cells.

Tetramethylpyrazine potentiates arsenic trioxide activity against HL-60 cell lines.

The objective of this study was to evaluate the effects of tetramethylpyrazine (TMP) in combination with arsenic trioxide (As2O3) on the proliferation and differentiation of HL-60 cells. The HL-60 cells were treated with 300 µg/mL TMP, 0.5 µM As2O3, and 300 µg/mL TMP combined with 0.5 µM As2O3, respectively. The proliferative inhibition rates were determined with MTT. Differentiation was detected by the nitroblue tetrazolium (NBT) reduction test, Wright's staining and the distribution of CD11b and CD14. Flow cytometry was used to analyze cell cycle distribution. RT-PCR and Western blot assays were employed to detect the expressions of c-myc, p27, CDK2, and cyclin E1. Combination treatment had synergistic effects on the proliferative inhibition rates. The rates were increased gradually after the combination treatment, much higher than those treated with the corresponding concentration of As2O3 alone. The cells exhibited characteristics of mature granulocytes and a higher NBT-reducing ability, being a 2.6-fold increase in the rate of NBT-positive ratio of HL-60 cells within the As2O3 treatment versus almost a 13-fold increase in the TMP + As2O3 group. Cells treated with both TMP and As2O3 expressed far more CD11b antigens, almost 2-fold compared with the control group. Small doses of TMP potentiate As2O3-induced differentiation of HL-60 cells, possibly by regulating the expression and activity of G0/G1 phase-arresting molecules. Combination treatment of TMP with As2O3 has significant synergistic effects on the proliferative inhibition of HL-60 cells.