A Multi-site In-depth Evaluation of the Quanterix Simoa from a User’s Perspective

An in-depth evaluation of the Quanterix© Simoa? platform was undertaken by scientists from the AAPS Emerging Technologies Focus Group to determine the overall performance of the technology as well as provide guidance to future users. In order to test the platform in a non-GLP bioanalytical setting, a cross-site evaluation of the Quanterix IL-6 biomarker kit was performed. Parameters tested during this evaluation included sensitivity, accuracy and precision, and parallelism in human serum from normal individuals. The results demonstrated improved sensitivity compared to the claimed sensitivity of other commercially available IL-6 kits and showed excellent site-to-site reproducibility. Observed issues included difficulties with system reliability and a lack of parallelism and specificity in a subset of samples. Overall, these results demonstrate that while there are challenges to the Simoa platform this technology offers automation capabilities and excellent sensitivity that enhance bioanalysis especially of low-abundance analytes.     

Perturbations in the erythroid marrow progenitor cell pools may play a role in the augmentation of HbF by 5-azacytidine

In vivo observations on the kinetics of F cells and of fetal hemoglobin (HbF) synthesis and in vitro studies of erythroid progenitors, their number, and the gamma-gene expression in their progeny were carried out in baboons (Papio cynocephalus) treated with 5-azacytidine. Maximum effect on the increase of HbF production in vivo was observed only when an expanded erythroid marrow population was present. In these animals, as well as in normal animals, treatment resulted in a significant reduction of the late erythroid progenitor cell pools (erythroid clusters and erythroid colony-forming units, CFU-E) in the marrow. This reduction was more pronounced among those progenitors grown in the absence of added erythropoietin, and it was followed by a rebound a few days after treatment cessation, reflecting the accumulation of regenerating progenitors. An early increase in the in vitro synthesis of HbF in erythroid clusters and CFU-E colonies was observed. This increase was further documented at the cellular level, with immunofluorescent labeling of colonies with monoclonal anti-gamma- globin chain antibodies. In contrast to the findings in late progenitors, the number of erythroid burst-forming unit (BFU-E) colonies and the synthesis of HbF in these colonies was not influenced significantly by 5-azacytidine treatment. It is proposed that the toxic effects of 5-azacytidine on late progenitors, leading to faster mobilization of earlier progenitors to the next more mature compartment, play a role in the in vivo augmentation of HbF synthesis by this drug. This perturbation in the progenitor cell population kinetics and the presumed hypomethylation of the surviving differentiating cells may act synergistically to produce a maximum HbF response after 5-azacytidine treatment.     

Effects of human FLT3 ligand on myeloid leukemia cell growth: heterogeneity in response and synergy with other hematopoietic growth factors

A novel hematopoietic growth factor for primitive hematopoietic progenitor cells, the ligand for the flt3/flk2 receptor, (FL), has been recently purified and its gene has been cloned. In the present study, we investigated the effects of FL on the proliferation and differentiation of normal and leukemic myeloid progenitor cells. We demonstrate that FL is a potent stimulator of the in vitro growth of granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin- 3 (IL-3), or G-CSF-dependent granulocyte-macrophage committed precursors from Lin- CD34+ bone marrow cells of normal donors. By contrast, FL does not affect the growth of erythroid-committed progenitors even in the presence of erythropoietin. The effect of FL on the proliferation and on the in vitro growth of clonogenic leukemic precursor cells was studied in 54 acute myeloid leukemia (AML) cases. Fresh leukemia blasts from 36 of 45 patients with AML significantly responded to FL without any relation to the French-American-British (FAB) subtype. FL stimulated the proliferation of leukemic blasts in a dose-dependent fashion. Synergistic activities were seen when FL was combined with G-CSF, GM-CSF, IL-3, or stem cell factor (SCF). FL as a single factor induced or increased significantly colony formation by clonogenic precursor cells from 21 of 24 patients with AML. In the presence of suboptimal and optimal concentrations of G-CSF, GM-CSF, IL3, SCF, or a combination of all factors, FL strongly enhanced the number of leukemic colonies (up to 18-fold). We also evaluated the induction of tyrosine phosphorylated protein on FL stimulation in fresh AML cells. We demonstrate that, on FL stimulation, a band of phosphorylated protein(s) of about 90 kD can be detected in FL- responsive, but not in FL-unresponsive cases. This study suggests that FL may be an important factor for the growth of myeloid leukemia cells, either as a direct stimulus or as a synergistic factor with other cytokines.     

Comparing patient generated blood glucose diary records with meter memory in type 2 diabetes

Aim

To assess agreement between meter and diary self monitoring of blood glucose (SMBG) records, over a year, in a sample of patients with type 2 diabetes.

Methods

Meter and diary records were available, for 95 individuals, who took part in the Efficacy of self monitoring of blood glucose in patients with newly diagnosed type 2 diabetes study.Pearson's correlation coefficient was used to explore the relationships between the types of error. Maximum likelihood estimation was used to explore changes over time through a structural equation modelling approach. Paired samples t-tests were used to determine if the presence of errors led to a significant difference between the mean diary and meter SMBG concentrations or coefficients of variation. Multiple regression was used to explore possible predictors of the error indices.

Results

Mean over-reporting, under-reporting, concordance and overall reliability were 8.4%, 10.0%, 83.5% and 71.3%, respectively. The first week of monitoring had significantly more under-reporting, over-reporting and less concordance and overall reliability than subsequent weeks. The majority of concordance errors were not clinically significant. Those that were, tended to occur during the first three months of monitoring. Participants’ at one trial site were significantly more likely to have recording errors than those at the largest site.

Conclusions

Error levels were similar to those described previously in type 1 diabetes and there was a suggestion of an initial learning curve for record keeping. For some individuals diary records would not be considered acceptable if held to the same standards as blood glucose meters.     

Concomitant use of oral anticoagulants in patients with advanced prostate cancer receiving apalutamide: A post-hoc analysis of TITAN and SPARTAN studies

Apalutamide, an androgen receptor signaling inhibitor, in combination with androgen-deprivation therapy (ADT), is approved for treatment of patients with nonmetastatic castration-resistant prostate cancer and metastatic castration-sensitive prostate cancer, based on the data from the phase 3 SPARTAN and TITAN studies respectively. Apalutamide is an inducer of cytochrome P450 enzymes and P-glycoprotein, which are involved in the metabolism of oral anticoagulants (OACs) and may thus have potential drug-drug interactions when co-administered with OACs. Concomitant use of certain OACs such as apixaban, rivaroxaban, edoxaban, dabigatran, and warfarin was allowed in the SPARTAN and TITAN studies. A post-hoc analysis was conducted to evaluate the incidence of treatment-emergent thrombotic and embolic adverse events (AEs) in patients receiving concomitant OACs with apalutamide + ADT or placebo + ADT in both the studies. Anticoagulants were identified by WHO Drug Anatomical Therapeutic Chemical level 4 classifications. Thrombotic and embolic AEs were coded using the Medical Dictionary for Regulatory Activities Version 22.1. Data were analyzed from patients receiving concurrent OACs among all treated patients in SPARTAN (apalutamide + ADT: 95/803 [11.8%]; placebo + ADT: 48/398 [12.1%]) and TITAN (apalutamide + ADT: 31/524 [5.9%]; placebo + ADT: 28/527 [5.3%]). No consequential differences were observed in the occurrence of thrombotic and embolic events between apalutamide + ADT and placebo + ADT groups receiving concomitant OACs in SPARTAN (11.6% vs 12.5%) or TITAN (19.4% vs 21.4%). Grade 3/4 thrombotic and embolic AEs observed in patients receiving concomitant OACs with apalutamide + ADT or placebo + ADT were 6 (6.3%) vs 5 (10.4%) in SPARTAN and 3 (9.7%) vs 1 (3.6%) in TITAN. This analysis suggests that when necessary, concomitant OACs can be used with apalutamide with appropriate monitoring.     

经皮椎体注入骨水泥治疗老年脊椎骨质疏松压缩性骨折

目的:观察经皮椎体内注入骨水泥(聚甲基丙烯酸甲酯)治疗脊椎骨质疏松压缩性骨折的疗效。方法:自2005-06/2006-06吉林大学中日联谊医院骨科及大庆龙南医院骨科对35例40个椎体的骨质疏松压缩性骨折患者使用经皮椎体内注射骨水泥,行椎体成形术。成形材料:美国KYPHON公司生产的骨水泥,生产准许号:(GB/T19001-2000和YY/T0287-1996)。结果:35例患者均参加随访6个月。术后均未出现骨水泥外漏、脊髓或马尾神经损伤等并发症。35例患者中5例出现穿刺部位局部疼痛,服用镇痛药物后均缓解。疼痛完全消失25例,占71.4%;明显缓解8例,占22.6%;轻度缓解2例,占6.0%;无缓解0例。15例患者在术后72h内均能下床活动。术后未再发生压缩性骨折及疼痛。结论:经皮椎体注入骨水泥可以有效改善椎体骨质疏松压缩性骨折患者疼痛症状,随访6个月未出现充填剂不良性宿主反应,临床疗效较好。