Read carefully, because this is important! How value-driven strategies impact sentence memory.

Little is understood about how people strategically process and remember important but complex information, such as sentences. In the current study, we asked whether people can effectively prioritize memory for sentences as a function of their relative importance (operationalized as a reward point value) and whether they do so, in part, by changing their sentence processing strategies when value information is available in advance. We adapted the value-directed remembering paradigm (Castel, Psychol Learn Motiv 48:225-270, 2007) for sentences that varied in constraint and predictability. Each sentence was associated with a high or low value for subsequent free recall (whole sentence) and recognition (sentence-final words) tests. Value information appeared after or before each sentence as a between-subject manipulation. Regardless of condition, we observed that high-value sentences were recalled more often than low-value sentences, showing that people can strategically prioritize their encoding of sentences. However, memory patterns differed depending on when value information was available. Recall for high-value sentences that ended unexpectedly (and therefore violated one's predictions) was reduced in the Before compared to the After condition. Before condition participants also showed a greater tendency to false alarm to lures (words that were the predicted - but not obtained - ending) from strongly constraining sentences. These observations suggest that when people try to prioritize sentence-level information that they know is valuable, the reading strategies they employ may paradoxically lead to worse memory.

Dynamic interactions of lactic acid bacteria in Korean sourdough during back-slopping process.

AIMS: This study aimed to clarify the cause of quality reduction in Korean sourdough after successive back-slopping. METHODS AND RESULTS: We investigated the dynamic changes in lactic acid bacteria during the back-slopping process using genetic fingerprinting techniques. During the initial propagation phases, the dominant lactic acid bacteria were Fructilactobacillus sanfranciscensis (<5 log CFU per g sourdough), Latilactobacillus curvatus (9·5 log CFU per g sourdough) and Levilactobacillus brevis (6·5 log CFU per g sourdough). However, after the 11th propagation, F. sanfranciscensis became more prominent (>9·0 log CFU per g sourdough), whereas L. curvatus and L. brevis rapidly decreased. Monitoring these bacteria in the co-culture system revealed that acid-tolerant F. sanfranciscensis rapidly utilized maltose (1·65 g l-1  h-1 ) and produced large amounts of lactic acid, whereas L. brevis and L. curvatus consumed maltose slowly and L. curvatus was poorly tolerant to lactic acid. CONCLUSION: The results indicate that competition exists between the lactic acid bacteria in sourdough during the back-slopping process, and microbial succession by acid-tolerant species results in quality reduction of sourdough. SIGNIFICANCE AND IMPACT OF THE STUDY: This study uncovered the cause of microbial changes during the propagation of Korean sourdough and proposed a strategy to develop starters to produce high-quality bakery products.

Surgical repair of primary non-complex rhegmatogenous retinal detachment in the modern era of small-gauge vitrectomy.

OBJECTIVE: To report anatomic and visual outcomes of pars plana vitrectomy (PPV), as well as scleral buckling (SB) and PPV/SB as surgical treatments for the management of primary, non-complex rhegmatogenous retinal detachment (RRD). METHODS AND ANALYSIS: Data from 751 eyes that underwent PPV, SB or combined PPV/SB as a surgical treatment for primary non-complex RRD with at least 3 months of follow-up were analysed to determine rates of single surgery anatomic success (SSAS) and final anatomic success (FAS). Patients or the public were not involved in the design, conduct or reporting of this research. RESULTS: PPV accounted for 89.0% (n=668), PPV/SB for 6.8% (n=51) and SB for 4.2% (n=32) cases. Overall SSAS (91.2% PPV, 84.3% PPV/SB, 93.8% SB; p=0.267) and FAS (96.7% PPV, 94.1% PPV/SB and 100.0% SB; p=0.221) were reported for the three surgical groups. SSAS and FAS were similar for lens status, macular detachment status and the presence or absence of inferior retinal breaks for each of the PPV, PPV/SB and SB groups. CONCLUSIONS: In this large, single institution, retrospective case series, we report surgical outcomes for patients with primary non-complex RRD managed with PPV, SB or PPV/SB in the modern era of small-gauge vitrectomy. We demonstrate that primary PPV without adjunct SB provides excellent anatomic and visual outcomes irrespective of lens status, macular involvement or pathology location.

Efficacy and tolerability of febuxostat in gout patients on dialysis.

BACKGROUND: There are no sufficient data available on the use of febuxostat in patients undergoing dialysis. AIM: To investigate the efficacy and tolerability of febuxostat in gout patients on dialysis. METHODS: We retrospectively reviewed clinical and laboratory data available from a referral centre from January 2012 to December 2018. We included gout patients who initiated febuxostat during dialysis. Data regarding serum uric acid levels before and after the febuxostat treatment and clinical information such as gout attack after febuxostat initiation, as well as adverse events involving febuxostat treatment, were obtained from medical records. RESULTS: Among 62 patients who were treated with febuxostat for over 3 months, 45 were undergoing haemodialysis (HD) and 17 were undergoing peritoneal dialysis (PD). The mean serum uric acid level was significantly reduced 3 months after treatment (3.71 ± 1.32 mg/dL) compared with that at the pretreatment level (9.36 ± 2.06 mg/dL) (P < 0.001). The serum uric acid level was observed to be significantly reduced at 3 months in both HD and PD patients and subsequently remained at a significantly reduced level for 12 months. Of the 62 patients, only two stopped febuxostat due to its adverse effects. Initial dose of 80 mg/day was associated with higher adverse events compared to dose of 20-40 mg/day (odds ratio 8.25, 95% confidence interval 1.90-35.97, P = 0.006). CONCLUSIONS: Febuxostat is efficacious and well tolerated in gout patients on dialysis. Febuxostat taken at dose of 20-40 mg/day might be appropriate initial dose in patients undergoing dialysis.

Nonpharmaceutical Measures for Pandemic Influenza in Nonhealthcare Settings-Social Distancing Measures.

Influenza virus infections are believed to spread mostly by close contact in the community. Social distancing measures are essential components of the public health response to influenza pandemics. The objective of these mitigation measures is to reduce transmission, thereby delaying the epidemic peak, reducing the size of the epidemic peak, and spreading cases over a longer time to relieve pressure on the healthcare system. We conducted systematic reviews of the evidence base for effectiveness of multiple mitigation measures: isolating ill persons, contact tracing, quarantining exposed persons, school closures, workplace measures/closures, and avoiding crowding. Evidence supporting the effectiveness of these measures was obtained largely from observational studies and simulation studies. Voluntary isolation at home might be a more feasible social distancing measure, and pandemic plans should consider how to facilitate this measure. More drastic social distancing measures might be reserved for severe pandemics.

Nonpharmaceutical Measures for Pandemic Influenza in Nonhealthcare Settings-Personal Protective and Environmental Measures.

There were 3 influenza pandemics in the 20th century, and there has been 1 so far in the 21st century. Local, national, and international health authorities regularly update their plans for mitigating the next influenza pandemic in light of the latest available evidence on the effectiveness of various control measures in reducing transmission. Here, we review the evidence base on the effectiveness of nonpharmaceutical personal protective measures and environmental hygiene measures in nonhealthcare settings and discuss their potential inclusion in pandemic plans. Although mechanistic studies support the potential effect of hand hygiene or face masks, evidence from 14 randomized controlled trials of these measures did not support a substantial effect on transmission of laboratory-confirmed influenza. We similarly found limited evidence on the effectiveness of improved hygiene and environmental cleaning. We identified several major knowledge gaps requiring further research, most fundamentally an improved characterization of the modes of person-to-person transmission.

Comparison of elapegademase and pegademase in ADA-deficient patients and mice.

The absence of adenosine deaminase (ADA) causes severe combined immune deficiency (SCID), which has been treated with PEGylated bovine-extracted ADA (ADAGEN). ADAGEN was recently replaced by a PEGylated recombinant bovine ADA, expressed in Escherichia coli (elapegademase, ELA-ADA). Limited information on ELA-ADA is available.  ADA enzymatic activity of ELA-ADA and ADAGEN was assessed in vitro at diverse dilutions. ADA activity and immune reconstitution in an ADA-SCID patient treated with ELA-ADA were compared with age-matched patients previously treated with ADAGEN. ADA activity and thymus reconstitution were evaluated in ADA-deficient mice following ELA-ADA or ADAGEN administered from 7 days postpartum. In vitro, ADA activity of ELA-ADA and ADAGEN were similar at all dilutions. In an ADA-SCID patient, ELA-ADA treatment led to a marked increase in trough plasma ADA activity, which was 20% higher than in a patient previously treated with ADAGEN. A marked increase in T cell numbers and generation of naive T cells was evident following 3 months of ELA-ADA treatment, while T cell numbers increased following 4 months in 3 patients previously treated with ADAGEN. T cell proliferations stimulation normalized and thymus shadow became evident following ELA-ADA treatment. ADA activity was significantly increased in the blood of ADA-deficient mice following ELA-ADA compared to ADAGEN, while both treatments improved the mice weights, the weight, number of cells in their thymus and thymocyte subpopulations. ELA-ADA has similar in- vitro and possibly better in-vivo activity than ADAGEN. Future studies will determine whether ELA-ADA results in improved long-term immune reconstitution.

Abnormal expression of the co-stimulatory molecule B7-H3 in lichen simplex chronicus is associated with expansion of Langerhans cells.

BACKGROUND: The co-stimulatory molecule B7-H3, a cell surface transmembrane glycoprotein, was assessed for its functional and prognostic role in lichen simplex chronicus (LSC). AIM: To investigate if abnormal expression of the co-stimulatory molecule B7-H3 in LSC is associated with Langerhans cell (LC) expansion. METHODS: We used immunohistochemistry to stain LSC skin tissue, and evaluated if the immunostaining of B7-H3 and interleukin (IL)-6 was significantly different. RESULTS: Our results indicated that B7-H3 is abnormally expressed in LSC skin tissue and positively regulates LC expansion. We also found that IL-6 might modulate B7-H3 expression. Moreover, LC expansion in LSC leads to the proliferation of T cells. CONCLUSIONS: Our study indicates the potential value of immunotherapy as a treatment for LSC.

Extracellular production of functional single-chain variable fragment against aflatoxin B1 using Escherichia coli.

scFv-BM3 is a single-chain variable fragment (scFv) against aflatoxin B1 (AFB1 ) engineered by affinity maturation and site-directed mutagenesis, and thus has a 31-fold higher affinity than its wild-type. To apply scFv-BM3 to immunological detection of AFB1 , periplasmic expression in Escherichia coli was attempted to produce a functional form of scFv-BM3. scFv-BM3 accumulated as inactive aggregates in the cells. However, it was found that scFv-BM3 secreted into the culture medium had binding activity to AFB1 . Expression conditions for scFv-BM3 were further manipulated to enhance secretion into the culture medium. This extracellular secretion of functional scFv-BM3 was significantly improved by supplementation with Triton X-100 and optimization of expression conditions. The scFv-BM3 purified from the culture medium exhibited a typical antiparallel ß-sheet structure and adopted a proper conformation to bind AFB1 with high affinity and specificity in various biophysical and biochemical analyses. SIGNIFICANCE AND IMPACT OF THE STUDY: Single-chain variable fragments (scFvs) are recombinant antibodies that are difficult to produce as a functional form in Escherichia coli. This study demonstrates the production of functional scFvs against aflatoxin B1 (AFB1 ) (scFv-BM3) using Escherichia coli by extracellular secretion. While periplasmic expression of scFv-BM3 resulted in formation of inactive aggregates in E. coli, the scFv-BM3 secreted into the culture medium adopted a properly folded structure for specific binding to AFB1 . This study promotes the application of functional scFv-BM3 to the immunological detection of AFB1 in biotechnology fields.

[Synthesis, characterization and antitumor activity of 5-fluorouracil-nicotinamide cocrystal].

Objective: To synthesize 5-fluorouracil-nicotinamide (5-FU-NCT) cocrystal and to investigate its physicochemical and biological properties. Methods: The cocrystal of 5-Fu-NCT was prepared through the cooling technology. PXRD, NMR, FTIR and DSC were used to characterize the structure of 5-FU-NCT cocrystal. Solubility was measured by HPLC method. Drug resistant human liver cancer BEL-7402/5-FU cells were treated with 5-FU-NCT cocrystal, the inhibition effect was tested by MTT and HE staining, and cancer cell migration was determined by scratch test. Results: According to PXRD, NMR, FTIR and DSC results, the cocrystal of 5-Fu-NCT had been synthesized successfully. The characteristic diffraction peaks (2θ/°) of the cocrystal were 16.4, 20.4, 22.3, 27.9 and 30.1. The solubility of 5-FU-NCT was 13.5 g/L as measured by HPLC. The antitumor activity tests showed that 5-FU-NCT cocrystal enhanced anticancer effect of 5-FU, and the IC50 of 5-FU and 5-FU-NCT was 129.6 µg/mL and 42.6 µg/mL, respectively. Conclusion: 5-Fu-NCT cocrystal have been synthesized successfully through the cooling technology and it shows an enhanced anticancer effect in comparison to 5-FU on BEL-7402/5-FU cells.

[Synthesis of BODIPY photosensitizers and their photodynamic effect on cancer cells].

Objective: To design and synthesize photosensitizers with different substituents and to identify its physicochemical characteritics and photodynamic effect on cancer cells. Methods: Two kinds of BODIPY photosensitizers BPOI and BPCI were synthesized through condensation reaction between aldehyde and reactive hydrogen of pyrrole, followed with electrophilic substitution reaction. Physicochemical properties were characterized by 1H NMR, FT-IR and UV-visible absorption spectra and fluorescence emission spectra. The ability to produce reactive oxygen species was detected by BPDF and DCFH-DA. Photodynamic therapy effect on rat glioma C6 cells in vitro was determined by MTT method. Results: Two kinds of BODIPY photosensitizers BPOI and BPCI were successfully synthesized with different substituents, which were confirmed by 1H NMR, FT-IR. Both materials had low toxicity and could be readily taken up by tumor cells. The ability of synthesized photosensitizers to produce reactive oxygen species was strongly influenced by solvent polarity when the substituent was electron-donating group, while no effect was found when the substituent was electron-withdrawing group. Conclusion: Photosensitizer BPOI with electron-donating substituent produces reactive oxygen species with a slow rate in a highly polar environment, while greatly enhanced this effect in a low polarity environment, which is expected to be used for environmental-selective photodynamic therapy in tumor cells.

[Bacterial outer membrane vesicles as nano carriers to study immunological activities].

Objective: To prepare a nano-carrier based on combining bacterial outer membrane vesicles (OMV) with three block polymer pluronic F127 (PEO100-PPO65-PEO100) (OMV-F127) and to investigate its immunological activity. Methods: Attenuated salmonella (sal) was cultivated. OMV were separated by centrifugal ultrafiltration or ultrasonication, and OMV-F127 was prepared by mechanical extrudation method. The protein contents and compositions were tested with BCA and SDS-PAGE; the morphology of OMV, F127 and OMV-F127 were observed with FM and TEM; the particle sizes and their zeta potential were determined with DLS. Mouse macrophage RAW246.7 cells were treated with OMV-F127 (50 µg/mL, 100 µg/mL) in vitro, and the concentrations of IL-12, TNF-α and IFN-γ in culture supernatant were measured with ELISA kits. Results: The contents of protein in separated OMV by centrifugal ultrafiltration and ultrasonication were 2.8 mg/mL and 2.7 mg/mL, respectively. SDS-PAGE showed the marker protein OmpF/C in OMV. Under the FM and TEM, ball-like structure of F127 and OMV-F127 was observed. Size analysis revealed that the diameters of OMV, F127 and OMV-F127 were 72±2 nm, 90±3 nm and 92±2 nm, respectively. ELISA tests revealed that OMV-F127 significantly stimulated the secretion of IL-12, TNF-α and IFN-γ in RAW246.7 cells. Conclusion: A nano-carrier based on bacterial outer membrane vesicles has been prepared, which can stimulate the secretion of cytokines and may have immunomodulatory effects.

Neural Signals Related to Outcome Evaluation Are Stronger in CA1 than CA3.

We have shown previously that CA1 conveys significant neural signals necessary to update value of the chosen target, namely chosen value and reward signals. To better understand hippocampal neural processes related to valuation, we compared chosen value- and reward-related neural activity between the CA3 and CA1 regions. Single units were recorded with tetrodes from the dorsal CA3 and CA1 regions of rats performing a dynamic foraging task, and chosen value- and reward-related neural activity was estimated using a reinforcement learning model and multiple regression analyses. Neural signals for chosen value and reward converged in both CA3 and CA1 when a trial outcome was revealed. However, these neural signals were stronger in CA1 than CA3. Consequently, neural signals for reward prediction error and updated chosen value were stronger in CA1 than CA3. Together with our previous finding that CA1 conveys stronger value signals than the subiculum, our results raise the possibility that CA1 might play a particularly important role among hippocampal subregions in evaluating experienced events.

Dynamic prognostic value of the revised international prognostic scoring system following pretransplant hypomethylating treatment in myelodysplastic syndrome.

This study aimed to analyze the use of the revised International Prognostic Scoring System (IPSS-R) assessed after hypomethylating treatment (HMT) for patients with myelodysplastic syndrome (MDS) undergoing an allogeneic stem cell transplantation (SCT). Among 115 patients who received pre-SCT HMT, comparison analysis of the prognostic values between the IPSS-R at the time of HMT (IPSS-R@HMT) and at the time of SCT after HMT (IPSS-R@SCT) showed a significantly higher predictive power for overall survival (OS) of the latter. Alteration in IPSS-R risk occurred in 60%, while the patients with 'down-staged' IPSS-R@SCT showed better OS compared with those with 'unchanged' or 'up-staged' risk. On multivariate analysis in all 201 patients, IPSS-R@SCT, monosomal karyotype, treatment failure to pre-SCT treatment, and high hematopoietic cell transplantation-comorbidity index were independently associated with OS. Constructed using these factors, the MDS Transplantation Prognostic Scoring System (MTPSS) identified four risk groups with 4-year OS of 76.4% in low, 61.4% in intermediate-1 and 21.9% in intermediate-2 risk groups, whereas all in the high risk group died within 2 years after SCT (P<0.001). Our study emphasizes the need for further studies aiming to evaluate a transplantation prognostic model such as the MTPSS to make appropriate decisions for transplantation in MDS.

Comparable outcomes between younger (⩽40 years) and older (>40 years) adult patients with severe aplastic anemia after HLA-matched sibling stem cell transplantation using fludarabine-based conditioning.

Allogeneic stem cell transplantation from HLA-matched siblings (MSD-SCT) for elderly patients with severe aplastic anemia (SAA) is not a widely accepted first-line treatment. Recently, fludarabine, lower-dose cyclophosphamide and antithymocyte globulin conditioning (Flu/lower-dose Cy/ATG) with lower toxicities has been investigated. To determine whether this regimen can overcome the negative effects of age, we analyzed 117 adult patients with SAA who received MSD-SCT using Flu/lower-dose Cy/ATG, and compared outcomes between 63 younger age group (YAG; ⩽40 years) and 54 older age group (OAG; >40 years) patients. No primary graft failure was observed. Neutrophil engraftment was significantly faster in the YAG compared with the OAG (12 vs 13 days; P=0.04). The incidences of acute grade II-IV (9.5% vs 9.3% at day 100; P=0.42) and chronic GVHD (8.1% vs 9.5% at 5 years; P=0.80), secondary graft failure (20.8% vs 7.9% at 5 years; P=0.11) and transplant-related mortality (5.4% and 11.1% at 5 years; P=0.91) were not significantly different between the YAG and OAG. In addition, failure-free (73.7% vs 81.0% at 5 years; P=0.73) and overall survival rates (93.7% vs 88.9% at 5 years; P=0.20) were comparable. Our results suggest that MSD-SCT using Flu/lower-dose Cy/ATG may be a feasible first-line treatment even in older patients with SAA.

Drug resistance and genetic characteristics of clinical isolates of staphylococci in Myanmar: high prevalence of PVL among methicillin-susceptible Staphylococcus aureus belonging to various sequence types.

Prevalence, drug resistance and genetic characteristics were analysed for a total of 128 clinical isolates of staphylococci obtained from a tertiary hospital in Myanmar. The dominant species were S. aureus (39%) and S. haemolyticus (35%), followed by S. epidermidis (6%) and S. saprophyticus (5%). The majority of S. haemolyticus isolates (71.1%) harboured mecA, showing high resistance rates to ampicillin, cephalosporins, erythromycin and levofloxacin, while methicillin-resistant S. aureus (MRSA) was only 8% (four isolates) among S. aureus with type IV SCCmec. Panton-Valentine leukocidin (PVL) genes were detected in 20 isolates of S. aureus (40%), among which only one isolate was MRSA belonging to sequence type (ST) 88/agr-III/coa-IIIa, and the other 19 methicillin-susceptible S. aureus (MSSA) isolates were classified into six STs (ST88, ST121, ST1153, ST1155, ST1930, ST3206). An ST1153 MSSA isolate with PVL was revealed to belong to a novel coa type, XIIIa. ST121 S. aureus was the most common in the PVL-positive MSSA (47%, 9/19), harbouring genes of bone sialoprotein and variant of elastin binding protein as a distinctive feature. Although PVL-positive MSSA was susceptible to most of the antimicrobial agents examined, ST1930 isolates were resistant to erythromycin and levofloxacin. ST59 PVL-negative MRSA and MSSA had more resistance genes than other MRSA and PVL-positive MSSA, showing resistance to more antimicrobial agents. This study indicated higher prevalence of mecA associated with multiple drug resistance in S. haemolyticus than in S. aureus, and dissemination of PVL genes to multiple clones of MSSA, with ST121 being dominant, among hospital isolates in Myanmar.

Impact of pretransplant red cell transfusion on outcome after allogeneic stem cell transplantation in adult patients with severe aplastic anemia.

The aim of this study was to evaluate the impact of pretransplant transfusion of packed red cells (PRCs) on outcome after allogeneic stem cell transplantation (SCT) in severe aplastic anemia (SAA). A total of 221 adult SAA patients receiving allogeneic SCT were analyzed. The patients were divided into two groups according to the amount of pretransplant transfusion before SCT: the low transfusion group (⩽32 PRC units, n=164) and the high transfusion group (>32 PRC units, n=57). The incidence of engraftment failure was not different between the two groups. The incidence of acute GvHD (grades II-IV) was higher in the high transfusion group than in the low transfusion group (P=0.04), and the incidences of chronic extensive GVHD were not significantly different (P=0.136). The high transfusion group had higher 5-year transplant-related mortality (TRM) (24.8% vs 6.8%, P<0.001) and lower overall survival (OS) (72.3% vs 91.9%, P<0.001) than those in the low transfusion group. Multivariate analysis revealed that the high transfusion group and unrelated donor type were independent prognostic factors affecting OS. These results indicate that a history of higher pretransplant transfusion of PRCs was associated with increased TRM and decreased OS, suggesting that iron overload had a negative impact on outcome after SCT in SAA.

Transfibular ankle arthrodesis using burring, curettage, multiple drilling, and fixation with two retrograde screws through a single lateral incision.

PURPOSE: To review the outcome of 23 ankle arthrodeses using burring, curettage, multiple drilling, and fixation with 2 retrograde screws through a single lateral incision. METHODS: Records of 22 consecutive patients aged 39 to 79 (mean, 62.4) years who underwent 23 ankle arthrodeses for end-stage ankle arthritis were reviewed. Through a single lateral incision, articular cartilage was removed using burring and curettage, and multiple holes were drilled using a Kirschner wire, followed by fixation with 2 retrograde screws. The resected distal fibula was fixed to the distal part of the talus and tibia. The position of the ankle and subtalar joint arthrosis was assessed by 2 orthopaedic specialists. Pre- and post-operative American Orthopaedic Foot and Ankle Society (AOFAS) scores were evaluated. RESULTS: The mean operating time was 122 minutes. The mean follow-up period was 41 months. The mean postoperative ankle alignment was suboptimal: 2.7º varus, 6.7º plantar flexion, and 2.9º internal rotation. The mean AOFAS score improved from 30 to 71 (p<0.01). The postoperative varus ankle alignment was not associated with the AOFAS score (r= -0.13, p=0.569). Of the 23 cases, one was nonunion and 22 achieved bone union after a mean of 5.4 (range, 2-16) months; 3 of them were delayed union. Despite bone union, 7 patients complained of persistent pain; 4 of them had progressive arthrosis of the adjacent subtalar joints (n=2) or subtalar and talonavicular joints (n=2). CONCLUSION: Ankle arthrodesis using burring, curettage, multiple drilling, and fixation with 2 retrograde screws achieved a high union rate and acceptable functional score without serious complications.

Significance of KIT exon 17 mutation depends on mutant level rather than positivity in core-binding factor acute myeloid leukemia.

KIT exon 17 mutation is a poor prognostic factor in core-binding factor acute myeloid leukemia. However, the mutation detection method used for risk assessment is not assigned. It is necessary to verify the analytical and clinical performance before applying new methods. Herein, we firstly applied a highly sensitive allele-specific, real-time quantitative PCR (AS-qPCR) assay to analyze KIT mutations, which demonstrated excellent sensitivity and specificity. Much higher incidence of KIT mutations (62.2%, 69/111) and prevalence of multiple mutations (43.5%, 30/69) were observed using AS-qPCR, which meant the existence of multiple KIT mutant subclones. The relative KIT mutant level was variable (median, 0.3 per control allele 100 copies, 0.002-532.7) and was divided into two groups: high (⩾10, n=26) and low (<10) mutant level. Interestingly, rather than mutation positivity, mutant level was found to be associated with clinical outcome. High mutant level showed significantly inferior overall survival (P=0.005) and event-free survival (P=0.03), whereas low level did not influence the prognosis. The follow-up data showed that the mutant level were along with fusion transcripts in the majority (n=29), but moved separately in some cases, including the loss of mutations (n=5) and selective proliferation of minor clones (n=2) at relapse. This study highlighted that the KIT mutation should be analyzed using sensitive and quantitative techniques and set a cutoff level for identifying the risk group.