Reversal of MYB-dependent suppression of MAFB expression overrides leukaemia phenotype in MLL-rearranged AML

The transcription factor MYB plays a pivotal role in haematopoietic homoeostasis and its aberrant expression is involved in the genesis and maintenance of acute myeloid leukaemia (AML). We have previously demonstrated that not all AML subtypes display the same dependency on MYB expression and that such variability is dictated by the nature of the driver mutation. However, whether this difference in MYB dependency is a general trend in AML remains to be further elucidated. Here, we investigate the role of MYB in human leukaemia by performing siRNA-mediated knock-down in cell line models of AML with different driver lesions. We show that the characteristic reduction in proliferation and the concomitant induction of myeloid differentiation that is observed in MLL-rearranged and t(8;21) leukaemias upon MYB suppression is not seen in AML cells with a complex karyotype. Transcriptome analyses revealed that MYB ablation produces consensual increase of MAFB expression in MYB-dependent cells and, interestingly, the ectopic expression of MAFB could phenocopy the effect of MYB suppression. Accordingly, in silico stratification analyses of molecular data from AML patients revealed a reciprocal relationship between MYB and MAFB expression, highlighting a novel biological interconnection between these two factors in AML and supporting new rationales of MAFB targeting in MLL-rearranged leukaemias.

AB0624 Patients with vasculitis have a high prevalence of coronary microvascular dysfunction

Background

Vasculitides are a heterogenous group of diseases characterized by intense vessel wall inflammation, endothelial injury, and systemic inflammation. Several vasculitides are associated with high risk of cardiovascular (CV) disease, an important source of morbidity and mortality in this population. This excess CV risk is attributed both to a high burden of traditional risk factors and to inflammation, but this remains poorly studied. Indeed, inflammation is a known risk factor for CV disease and implicated in coronary microvascular dysfunction (CMD) which may precede obstructive coronary artery disease (CAD).

Objectives

We sought to assess whether vasculitis is associated with CMD in the absence of obstructive CAD.

Methods

We retrospectively identified subjects with systemic vasculitis who underwent symptom prompted rest/stress myocardial perfusion PET. Patients with an abnormal myocardial perfusion study (summed stress score ≥3) or LVEF<40% were excluded. Controls were identified from the same population and matched on age, gender and cardiovascular risk factors (CAD, hypertension, dyslipidemia, diabetes mellitus, and obesity). Coronary flow reserve (CFR), was calculated as the ratio of myocardial blood flow (ml/min/g) at peak stress compared to rest. CMD was defined as CFR <2.

Results

We studied 26 vasculitis cases and 66 matched controls. The most common vasculitides were giant cell arteritis (38%), ANCA-associated vasculitis (31%), and Takayasu’s arteritis (12%). Median (IQR) time between diagnosis and PET was 6.5 (2.9, 14.2) years. Seven (27%) cases had active vascultis at the time of PET. Cases and controls were well-matched on age, sex, and CV risk factors (Table 1). Despite a similar prevalence of CV risk factors, coronary flow reserve (reflected by CMD) was abnormal in 38% of vasculitis cases compared to 15% of controls (p=0.004). The mean [SD] CFR was 19% lower in vasculitis cases vs controls (2.11 [0.5] versus 2.6 [0.7], p=0.003).

Table 1.

The presence of coronary microvasculature dysfunction in patients with systemic vasculitis without obstructive coronary artery disease

Cohort characteristicsVasculitis (n=26)Control (n=66)P-valueAge at PET, years62 (18)61 (17)0.24Time from Vasculitis Diagnosis to PET, years (median, IQR)6.5 (2.9, 14.2)n/aFemale, n (%)18 (72%)43 (65%)0.99Vasculitis CharacteristicsLarge Vessel (e.g., giant cell arteritis, Takayasu’s), n(%)13 (50%)n/an/aMedium Vessel (e.g., polyarteritis nodosa, Kawasaki’s arteritis), n(%)2 (8%)n/an/aSmall Vessel (e.g., ANCA-associated vasculitis, Henoch-Schonlein Purpura), n(%)11 (42%)n/an/aCardiovascular Risk FactorsAt DiagnosisAt PETAt PETHypertension, n (%)12 (46%)20 (71%)47 (80%)0.47Obesity, n (%)3 (12%)2 (32%)2 (32%)0.84Diabetes, n (%)3 (12%)5 (20%)13 (20%)0.99Dyslipidemia, n (%)4 (15%)15 (58%)40 (61%)0.99Known CAD, n (%)0 (0%)1 (4%)1 (2%)0.48Imaging FindingsRest myocardial blood flow, ml/min/g1.0 (0.3)1.0 (0.3)0.8Stress myocardial blood flow, ml/min/g2.1 (0.6)2.6 (1.0)0.008Coronary Flow Reserve, ml/min/g*2.1 (0.5)2.6 (0.7)0.003Coronary Microvasculature Dysfunction** (CMD), n (%)10 (38%)11 (15%)0.004

Conclusion

Patients with systemic vasculitis, even in the absence of obstructive CAD, have a high prevalence of CMD compared with non-vasculitis patients. These differences were observed despite matching cases and controls on traditional CV risk factors, highlighting the importance of other factors, such as inflammation and vasculitis treatments on CMD and CV disease in this population. CMD is a known independent risk factor for CV mortality. Future prospective studies are needed to understand the relationship between vasculitis, systemic inflammation, and CMD.

Disclosure of Interests

None declared

[Analysis of pathogen spectrum and antimicrobial resistance of pathogens associated with hospital-acquired infections collected from 11 teaching hospitals in 2018]

Objective: To investigate the spectrum and antimicrobial resistance of major pathogens causing nosocomial infections in China, 2018. Methods: Non-duplicated nosocomial cases as well as pathogens causing bloodstream infections (BSI), hospital-acquired pneumonia (HAP) and intra-abdominal infections (IAI) from 11 teaching hospitals across China were collected. The minimum inhibitory concentrations (MICs) of clinically significant strains were determined by agar dilution method or broth microdilution method. The Clinical and Laboratory Standards Institute (CLSI) M100-S29 criteria were used for interpretation, and the WHONET-5.6 software was used in data analysis. Results: A total of 1 590 cases were collected, including 831 cases from BSI, 450 cases from HAP and 309 cases from IAI. The most prevalent pathogens causing BSI were Escherichia coli (29.2%, 243/831), Klebsiella pneumoniae (16.2%, 135/831) and Staphylococcus aureus (10.1%, 84/831); the most prevalent pathogens causing IAI were E. coli (26.2%, 81/309), Enterococcus faecium (15.5%, 48/309) and K. pneumoniae (13.3%, 41/309); while Acinetobacter baumanii (24.7%, 111/450), Pseudomonas aeruginosa (20.7%, 93/450) and K. pneumoniae (16.2%, 73/450) were dominated in HAP. All S. aureus were susceptible to tigecycline, linezolid, daptomycin and glycopeptides; 77.8% (105/135) of S. aureus strains were susceptible to ceftaroline. Methicillin-resistant S. aureus (MRSA) accounted for 29.6% (40/135) of all the S. aureus, and was lower than the accounted rate of methicillin-resistant coagulase-negative Staphylococcus (MRCNS) (83.7%, 41/49). One E. faecium strain (1.1%, 1/95) resistant to vacomycin and teicoplanin and one E. faecalis strain (2.3%, 1/43) resistant to linezolid was found. The prevalence of extended-spectrum β-lactamase (ESBL) was 56.1% (193/344) in E. coli and 22.1% (55/249) in K. pneumonia; the rate of carbapenem resistant E. coli and K. pneumonia was 4.1% (14/344) and 22.9% (57/249), respectively; the percentage of ceftazidime/avibactam resistant E. coli and K. pneumonia was 2.3% (8/344) and 2.0% (5/249), respectively; the percentage of colistin resistant E. coli and K. pneumonia was 1.5% (5/344) and 7.6% (19/249), respectively; no E. coli and K. pneumonia strains were found resistant to tigecycline. The rate of carbapenem resistant A. baumanii and P. aeruginosa were 78.9% (146/185) and 36.7% (66/180), respectively. A. baumanii showed low susceptibility to the antimicrobial agents except colistin (99.5%, 184/185) and tigecycline (91.4%, 169/185). Colistin, amikacin and ceftazidime/avibactam demonstrated high antibacterial activity against P. aeruginosa with susceptility rate of 100% (180/180), 93.3% (168/180) and 85.6% (154/180), respectively. Conclusions: Nosocomial Gram-negative pathogens show high susceptibilities to tigecycline, colistin and ceftazidime/avibactam in vitro. Antimicrobial resistance in A. baumannii is a serious problem. The prevalence of carbapenem-resistant Enterobacteriaceae has increased, which should be monitored continuously in China.

Association of inflammatory disease and long-term outcomes among young adults with myocardial infarction: the Partners YOUNG-MI registry

Background

Autoimmune systemic inflammatory diseases are associated with an increased risk of cardiovascular disease, particularly myocardial infarction (MI). However, there are limited data on the prevalence and effects of inflammatory disease among U.S. adults who experience an MI at a young age.

Purpose

We sought to determine the prevalence and prognostic value of inflammatory disease in U.S. adults who experience an MI at a young age.

Methods

The YOUNG-MI registry is a retrospective cohort study of consecutive patients who experienced a Type 1 MI at or below the age of 50 years from 2000 to 2016 at two large medical centers. A diagnosis of rheumatoid arthritis (RA), psoriasis (PsO), systemic lupus erythematosus (SLE), or inflammatory arthritis was determined through physician review of electronic medical records (EMR). Demographic information, presence of cardiovascular (CV) risk-factors, medical procedures, and medications upon discharge were also ascertained from the EMR. Incidence of death was determined using a combination of EMR and national databases. Cox proportional hazard modeling was performed on a sub-sample following Mahalanobis Distance matching on age, sex, and CV risk factors.

Results

The cohort consisted of 2097 individuals (median age 45 years, 19% female, 53% ST-elevation MI). Among these, 53 (2.5%) individuals possessed a diagnosis of systemic inflammatory disease at or before their index MI (23% SLE, 9% RA, 64% PsO, 4% inflammatory arthritis). When compared to the remainder of the cohort, patients with a diagnosis of systemic inflammatory disease were more likely to be female (36% vs 19%, p=0.004) and be diagnosed with hypertension (62% vs 46%, p=0.025). There was, however, no significant difference in the prevalence of other CV risk factors – diabetes, smoking, dyslipidemia – or a family history of premature coronary artery disease. Despite these similarities, patients with inflammatory disease were less likely to be prescribed aspirin (88% vs 95%, p=0.049) or a statin (76% vs 89%, p=0.008) upon discharge. Over a median follow-up of 11.2 years, patients with inflammatory disease experienced an increased risk of all-cause mortality when compared with the full-cohort (Figure). Compared to the matched sample (n=138), patients with systemic inflammatory disease exhibited an increased risk of all-cause mortality (HR=2.68, CI [1.18 to 6.07], p=0.018), which remained significant after multivariable adjustment for length of stay and GFR (HR=2.38, CI [1.02 to 5.54], p=0.045).

Conclusions

Among individuals who experienced an MI at a young age, approximately 2.5% had evidence of a systemic inflammatory disease at or before their MI. When compared with a population of individuals with similar cardiovascular risk profiles, those with inflammatory disease had higher rates of all-cause mortality. Our findings suggest that the presence of a systemic inflammatory disorder is independently associated with worse long-term outcomes.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): 1. 5T32 HL094301 NIH T32 Training Grant, “Noninvasive Cardiovascular Imaging Research Training Program”

Coronary vasomotor dysfunction is associated with worse outcomes in patients with inflammatory disease

Background

Rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and psoriasis (PsO) are common inflammatory conditions with excess cardiovascular (CV) risk compared to the general population. This excess CV risk is associated with traditional risk factors, glucocorticoid treatment, and systemic inflammation. Systemic inflammation perturbs endothelial function and has been linked to coronary vasomotor dysfunction. It is not clear if coronary vasomotor dysfunction would be associated with worse clinical outcomes in systemic autoimmune inflammatory conditions.

Purpose

We tested the hypothesis that impaired coronary flow reserve (CFR), which in the absence of flow-limiting obstructive coronary artery disease (CAD) reflects vasomotor dysfunction, among patients with SLE, RA, and PsO is associated with worse clinical outcomes.

Methods

We included patients with RA, SLE, and PsO who underwent clinically indicated rest/stress myocardial perfusion positron emission tomography (PET) at a large academic medical center from 2006 to 2019. Patients with an abnormal myocardial perfusion study (summed stress score &gt;3) or left ventricular ejection fraction &lt;40% were excluded. CFR was calculated as the ratio of myocardial blood flow (MBF, ml/min/g) at peak stress compared to the MBF at rest and adjusted for baseline heart rate and blood pressure.

Results

Among the 175 patients (median age 65.1 years, 80% female) in the cohort, 24% had SLE, 35% PsO, and 41% RA. There was no difference in mean CFR between patients with RA, SLE, or PsO. Over a median follow-up of 8.5 years after PET, there were 47 deaths. Patients in the lowest and middle tertile (CFR &lt;2.18) had a higher all-cause mortality when compared with the highest (Figure 1), and this association remained significant after adjusting for age and a composite clinical score incorporating sex, symptoms, and CV risk factors (lowest vs. highest tertile: HR 2.8; 95% confidence interval 1.2–6.5; p=0.01). CV risk factors such as diabetes, hypertension, obesity, tobacco use, and a family history of CAD were not significantly different across CFR tertiles, suggesting that inflammatory-disease specific risk factors may contribute to coronary vasomotor dysfunction.

Conclusions

In patients with systemic inflammatory disease, coronary vasomotor dysfunction was associated with worse outcomes independent of traditional CV risk factors and may have utility as a marker of CV risk among patients with inflammatory disease.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): 1. 5T32HL094301-02 NIH T32 Training Grant, “Noninvasive Cardiovascular Imaging Research Training Program”

OP0111 RHEUMATOID ARTHRITIS SEROLOGIC PHENOTYPE AT DIAGNOSIS AND SUBSEQUENT RISK FOR PNEUMONIA IDENTIFIED USING MACHINE LEARNING APPROACHES

Background:

Patients with rheumatoid arthritis (RA) are at increased risk of serious infections, with considerable excess morbidity and mortality after pneumonia. RA-related autoantibodies such as anti-cyclic citrullinated peptide (CCP) and rheumatoid factor (RF) may be generated at inflamed pulmonary mucosa prior to clinical RA onset. Therefore, patients with seropositive RA may be at increased risk for pneumonia after RA diagnosis due to subclinical pulmonary injury.

Objectives:

We investigated whether seropositive RA was associated with increased pneumonia risk compared to seronegative RA.

Methods:

We performed a retrospective cohort study among RA patients seen at a health care system in Boston, MA. RA patients were identified using a previously validated electronic health record (EHR) algorithm incorporating billing codes, natural language processing (NLP) of notes, medications, and laboratory results at 97% specificity1. We constructed an incident RA cohort using NLP for the index date of initial mention of RA. All patients were required to have both CCP and RF data from clinical care to determine serologic RA phenotype. We used semi-supervised machine learning approaches to identify pneumonia using billing codes and terms extracted using NLP, with the Centers for Disease Control definition of pneumonia from medical record review as a gold standard. The area under the receiver operating curve (AUROC) for this billing code+NLP pneumonia algorithm was 0.94 compared to the standard rule-based pneumonia algorithm (billing code on inpatient discharge) AUROC of 0.86 (p<0.001). Smoking status was extracted using NLP methods. Other covariates, including a previous validated weighted RA multimorbidity score2, were determined using structured EHR data. We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for pneumonia adjusting for potential confounders.

Results:

We analyzed a total of 4,110 patients with incident RA and both CCP/RF data available. Mean age at index date was 53.0 years (SD 14.8), 77.2% were female, and 79.8% were CCP+ or RF+. During 32,248 patient-years of follow-up (mean 7.8 years/patient), we identified 240 pneumonia cases. Patients with seropositive RA had a HR of 1.99 (95%CI 1.30-3.01, Table) for pneumonia compared to patients with seronegative RA, adjusted for age, sex, smoking, index year, ESR level, glucocorticoid use, DMARD use, and weighted RA multimorbidity score. While CCP+ RA (HR 1.91, 95%CI 1.23-2.97) and RF+ RA (HR 2.07, 95%CI 1.35-3.16) had increased pneumonia risk compared to seronegative RA, the CCP+RF- RA subgroup had no association with pneumonia (HR 0.67, 95%CI 0.23-1.93).

Conclusion:

Patients with incident seropositive RA, particularly RF+ RA, had increased risk for pneumonia throughout the RA disease course that was not explained by measured confounders including smoking status, multimorbidity, medications, and ESR level. Further studies should investigate how RF+ may predispose RA patients to later develop pneumonia after clinical RA diagnosis.

References:

[1]Liao KP, Cai T, Gainer V, et al. Electronic medical records for discovery research in rheumatoid arthritis. Arthritis Care Res. 2010;62(8):1120–1127.

[2]Radner H, Yoshida K, Mjaavatten MD, et al. Development of a multimorbidity index: Impact on quality of life using a rheumatoid arthritis cohort. Semin Arthritis Rheum. 2015;45(2):167–173.

Disclosure of Interests:

Jeffrey Sparks Consultant of: Bristol-Myers Squibb, Optum, Janssen, Gilead, Weixing Huang: None declared, Bing Lu: None declared, Sicong Huang: None declared, Andrew Cagan: None declared, Vivian Gainer: None declared, Sean Finan: None declared, Guergana Savova: None declared, Daniel Solomon Grant/research support from: Funding from Abbvie and Amgen unrelated to this work, Elizabeth Karlson: None declared, Katherine Liao: None declared

Pithecellobium clypearia extract enriched in gallic acid and luteolin has antibacterial activity against MRSA and reduces resistance to erythromycin, ceftriaxone sodium and levofloxacin

AIMS

Antibiotic adjuvants can give a second life to the antibiotics to which bacteria are highly resistant. We evaluated the antimicrobial effects of extracts from Pithecellobium clypearia against methicillin-resistant Staphylococcus aureus (MRSA) and also the potential for synergy with several antibiotics.

METHODS AND RESULTS

For this study, four extracts from P. clypearia were tested on MRSA using the broth microdilution method for activity assessment. The ethyl acetate fraction (S20b) had the strongest antibacterial activity against MRSA among the fractions tested. In all, 14 compounds such as gallic acid and luteolin in S20b were analysed by UFLC-Q-TOF-MS/MS. S20b combined with erythromycin showed synergy effects against MRSA and combined with ceftriaxone sodium and levofloxacin showed additive effects against MRSA. Electron microscopy showed that extract S20b damaged the MRSA cell wall and K⁺ efflux measurements indicated that extract S20b increased cell membrane permeability. Moreover, S20b suppression of PBP2a expression was assessed by Western blot. Furthermore, an in vivo study was used to investigate the therapeutic potential of S20b based on a mouse pneumonia model.

CONCLUSIONS

The in vitro study results have shown that S20b not only inhibits MRSA growth directly but also reduces the resistance of MRSA to the evaluated antibacterial agents. Based on the in vivo study, it can be concluded that S20b can treat pneumonia in the mouse model.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first research to demonstrate that S20b can inhibit MRSA growth and reduce drug resistance of clinical isolates to antibiotics. S20b has the potential to be used as a therapeutic agent against MRSA and treatment for MRSA pneumonia.

Saccharomyces cerevisiae Hog1 MAP kinase pathway is activated in response to honokiol exposure

AIM

The goal of the study was to investigate the cellular tolerance mechanism in response to honokiol exposure.

METHODS AND RESULTS

The broth microdilution method was employed to test the sensitivity of different Saccharomyces cerevisiae strains to honokiol. Intracellular levels of reactive oxygen species (ROSs) were determined by DCFH-DA staining. The phosphorylation of Hog1 was evaluated by Western blot analysis. The mRNA expressions of genes involved in the Ras-cyclic AMP (cAMP) pathway were analysed by real-time reverse transcription polymerase chain reaction. We found that the sod1▵ mutant was hypersensitive to honokiol and produced more ROS compared with wild-type and sod2▵ cells. Hog1 was phosphorylated in response to honokiol exposure and deletion of HOG1 increased the sensitivity to honokiol. The expressions of genes involved in the Ras-cAMP pathway were down-regulated after honokiol exposure; exogenous cAMP significantly reduced the phosphorylation of Hog1, although the level was higher than the control level.

CONCLUSIONS

In addition to SOD1, the Ras-cAMP cascade and Hog1 MAP kinase pathway is essential for protecting against honokiol-induced oxidative stress.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results provide insight into the understanding of the action mechanism of honokiol.

Simultaneous detection of 45 fusion genes in leukemia by dual-color fluorescence real-time PCR

INTRODUCTION

Detection of recurrent genetic abnormalities is of great significance for a refined diagnosis and assessment of prognosis in leukemia. Conventional nested reverse transcription PCR is labor intensive and time-consuming.

METHODS

We have developed a novel dual-color TaqMan probe-based real-time PCR method for the simultaneous screening of 45 fusion transcripts in 12 parallel reactions. The method was tested and validated with cell lines carrying known fusion transcripts and patient samples.

RESULTS

A multiplex real-time PCR method was successfully developed for rapid detection of 45 fusion genes and validated for 15 of the more commonly detected fusion genes. Intra-assay reproducibility assessed for the most frequent rearrangements ranged from 0.41% to 0.74% for the coefficient of variation (CV) of cycle threshold (Ct) and the interassay reproducibility ranged from 1.62% to 2.83% in five separate experiments. The lowest detection limit for the translocations tested ranged between 1 : 16 000 and 1 : 32 000. Validation of the method with 213 patient samples showed 100% specificity and excellent consistence with conventional nested RT-PCR.

CONCLUSION

Overall, we believe that this method is easily applicable, cost-effective, and clinically useful for a rapid screening of fusion genes in the initial diagnostic phase of leukemia. Its use can also be extended to the monitoring of minimal residual disease.

In utero exposure of high-dose di-n-butyl phthalate resulted in opposite effects on testicular cell apoptosis in late embryonic and pubertal male rat offspring

Objective:

To investigate the effects of in utero exposure to high-dose di- n-butyl phthalate (DBP) on testicular cell apoptosis in late embryonic and pubertal male rat offspring.

Methods:

Twenty pregnant Sprague-Dawley (SD) rats were divided into two groups. During gestation day (GD) 12 to GD 19, control group was given 1 ml day−1 of olive oil and experimental group was given DBP 500 mg kg−1 day−1 by gavage. On GD 19.5 and postnatal day (PND) 45, the testes were removed. Morphological analysis of the testes was observed by transmission electron microscopy and hematoxylin and eosin (H&E) staining. Testicular cell apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). The expression of Bcl-2, Bax, and p53 was presented by immunohistochemistry (IHC) and western blot. Data of the two groups was compared using independent samples t-test and Mann–Whitney test by SPSS 20.0.

Results:

H&E staining showed that spermatogenetic cells were significantly decreased in DBP exposed pubertal rat testis. The apoptosis index of testes in DBP-treated group was significantly lower on GD 19.5 but higher on PND 45 than that of the controls ( p < 0.01). IHC and western blot revealed significantly increased expression of Bcl-2 in GD 19.5 rat testis and Bax and p53 in PND 45 rat testis after DBP exposure, compared with the control ( p < 0.05).

Conclusion:

In utero exposure of high-dose DBP resulted in opposite effects on testicular cell apoptosis in late embryonic and pubertal rat offspring. The overexpression of Bcl-2, Bax, and p53 might be related to the occurrence of abnormal apoptosis and finally produce male infertility.

Development of EST-SSR markers in the relict tree Davidia involucrata (Davidiaceae) using transcriptome sequencing

Davidia involucrata, reputed to be a "living fossil" in the plant kingdom, is a relict tree endemic to China. Extant natural populations are diminishing due to anthropogenic disturbance. In order to understand its ability to survive in a range of climatic conditions and to design conservation strategies for this endangered species, we developed genic simple sequence repeats (SSRs) from mRNA transcripts. In total, 142,950 contigs were assembled. Of these, 30,411 genic SSR loci were discovered and 12,208 primer pairs were designed. Dinucleotides were the most common (77.31%) followed by trinucleotides (16.44%). Thirteen randomly selected primers were synthesized and validated using 24 individuals of D. involucrata. The markers displayed high polymorphism with the number of alleles per locus ranging from 3 to 12 and the observed and expected heterozygosities ranging from 0.083 to 1.0 and 0.102 to 0.69, respectively. This large expressed sequence tag dataset and the novel SSR markers will be key tools in comparative studies that may reveal the adaptive evolution, population structure, and resolve the genetic diversity in this endangered species.

Visible and Near-Infrared Photothermal Catalyzed Hydrogenation of Gaseous CO2 over Nanostructured Pd@Nb2O5

The reverse water gas shift (RWGS) reaction driven by Nb2O5 nanorod-supported Pd nanocrystals without external heating using visible and near infrared (NIR) light is demonstrated. By measuring the dependence of the RWGS reaction rates on the intensity and spectral power distribution of filtered light incident onto the nanostructured Pd@Nb2O5 catalyst, it is determined that the RWGS reaction is activated photothermally. That is the RWGS reaction is initiated by heat generated from thermalization of charge carriers in the Pd nanocrystals that are excited by interband and intraband absorption of visible and NIR light. Taking advantage of this photothermal effect, a visible and NIR responsive Pd@Nb2O5 hybrid catalyst that efficiently hydrogenates CO2 to CO at an impressive rate as high as 1.8 mmol gcat-1 h-1 is developed. The mechanism of this photothermal reaction involves H2 dissociation on Pd nanocrystals and subsequent spillover of H to the Nb2O5 nanorods whereupon adsorbed CO2 is hydrogenated to CO. This work represents a significant enhancement in our understanding of the underlying mechanism of photothermally driven CO2 reduction and will help guide the way toward the development of highly efficient catalysts that exploit the full solar spectrum to convert gas-phase CO2 to valuable chemicals and fuels.

Development of expressed sequence tag-based microsatellite markers for the critically endangered Isoëtes sinensis (Isoetaceae) based on transcriptome analysis

Isoëtes sinensis is a critically endangered quillwort. To facilitate studies on the conservation genetics of this species, we developed expressed sequence tag-simple sequence repeat (EST-SSR) markers. A total of 50,063 unigenes were predicted by transcriptome sequencing, 5294 (10.6%) of which significantly matched 3011 Gene Ontology annotations and 2363 were assigned to Kyoto Encyclopedia of Genes and Genomes metabolic pathways. Most of these (2297) were involved in metabolism. A total of 1982 SSR motifs were identified, with trinucleotides being the dominant repeat motif, and 1438 (72.6%) SSR primers were designed. Eighteen randomly selected primer pairs were used to genotype 24 I. sinensis accessions, which confirmed the suitability of these novel markers for molecular studies of I. sinensis. The heterozygosity index value ranged between 0.0799 and 0.9106, while the Shannon-Wiener diversity index value ranged between 0.1732 and 2.5589. The EST-SSRs reported in this study are linked to genic sequences, and are therefore ideal for investigating the evolutionary history of I. sinensis. These markers, together with the large EST dataset generated in this study, will greatly facilitate conservation genetic studies of I. sinensis.

Meta-analysis of cardiovascular toxicity risks in cancer patients on selected targeted agents

PURPOSE

The purpose was to estimate the risk and severity of cardiovascular toxicities associated with selected targeted agents.

METHODS

We searched English-language literature for randomized clinical trials published between January 1, 2000 and November 30, 2013 of targeted cancer therapy drugs approved by the FDA by November 2010. One hundred ten studies were eligible. Using meta-analytic methods, we calculated the relative risks of several cardiovascular toxicities [congestive heart failure (CHF), decreased left ventricular ejection fraction (DLVEF), myocardial infarction (MI), arrhythmia, and hypertension (HTN)], adjusting for sample size using the inverse-variance technique. For each targeted agent and side effect, we calculated the number needed to harm.

RESULTS

Regarding CHF, trastuzumab showed significantly greater risk of all-grade and high-grade CHF. There was significant increased risk of all-grade DLVEF with sorafenib, sunitinib, and trastuzumab and high-grade DLVEF with bevacizumab and trastuzumab. Sorafenib was associated with significant increased all-grade risk of MI based on one study. None was associated with high-grade risk of MI or increased risk of arrhythmia. Bevacizumab, sorafenib, and sunitinib had significant increased risk of all-grade and high-grade HTN.

CONCLUSIONS

Several of the targeted agents were significantly associated with increased risk of specific cardiovascular toxicities, CHF, DLVEF, and HTN. Several had significant increased risk for high-grade cardiovascular toxicities (CHF, DLVEF, and HTN). Patients receiving such therapy should be closely monitored for these toxicities and early and aggressive treatment should occur. However, clinical experience has demonstrated that some of these toxicities may be reversible and due to secondary effects.

Spatial Separation of Charge Carriers in In2O3-x(OH)y Nanocrystal Superstructures for Enhanced Gas-Phase Photocatalytic Activity

The development of strategies for increasing the lifetime of photoexcited charge carriers in nanostructured metal oxide semiconductors is important for enhancing their photocatalytic activity. Intensive efforts have been made in tailoring the properties of the nanostructured photocatalysts through different ways, mainly including band-structure engineering, doping, catalyst-support interaction, and loading cocatalysts. In liquid-phase photocatalytic dye degradation and water splitting, it was recently found that nanocrystal superstructure based semiconductors exhibited improved spatial separation of photoexcited charge carriers and enhanced photocatalytic performance. Nevertheless, it remains unknown whether this strategy is applicable in gas-phase photocatalysis. Using porous indium oxide nanorods in catalyzing the reverse water-gas shift reaction as a model system, we demonstrate here that assembling semiconductor nanocrystals into superstructures can also promote gas-phase photocatalytic processes. Transient absorption studies prove that the improved activity is a result of prolonged photoexcited charge carrier lifetimes due to the charge transfer within the nanocrystal network comprising the nanorods. Our study reveals that the spatial charge separation within the nanocrystal networks could also benefit gas-phase photocatalysis and sheds light on the design principles of efficient nanocrystal superstructure based photocatalysts.

[The effect of phospholipid transfer protein on cigarette smoke extract induced epithelial-mesenchymal transition of rat alveolar type Ⅱ cells]

OBJECTIVE

To investigate the effect of phospholipid transfer protein(PLTP) on cigarette smoke extract(CSE) induced epithelial-mesenchymal transition(EMT) in rat alveolar Type Ⅱ cells (RLE-6TN).

METHODS

CSE of different concentrations (0%, 0.25%, 0.5% and 1%) was co-cultured for 2 or 3 days with RLE-6TN, either pre-treated or not pre-treated with siRNA-PLTP for 6 h. Expression levels of E-cadherin mRNA and Vimentin mRNA were examined by RT-PCR, while expression levels of PLTP, E-cadherin, N-cadherin and Vimentin were examined by Western blot.

RESULTS

Our results showed that the expression of E-cadherin mRNA decreased in CSE-treated groups: 1.01±0.05, 0.74±0.05, 0.65±0.03, 0.30±0.08 respectively at different concentrations of CSE (0 %, 0.25%, 0.5 %, and 1.0%); while the level of Vimentin mRNA increased significantly in 1% CSE treated cells(1.88±0.49), compared with control cells (1.01±0.20). Treatment with CSE at different concentrations (0%, 0.25%, 0.5% and 1%) showed that the protein levels of PLTP were 0.42±0.02, 0.89±0.25, 1.08±0.18, 1.61±0.06 respectively; those of E-cadherin were 1.61±0.04, 1.08±0.10, 0.62±0.08, 0.68±0.17, respectively; those of N-cadherin were 0.60±0.14, 0.57±0.26, 0.88±0.30, 1.94±0.54, respectively; and those of Vimentin were 0.61±0.05, 0.98±0.16, 1.07±0.14, 1.34±0.19, respectively; all P<0.05 when the 1% CSE group was compared with the control group. EMT induced by CSE was significantly inhibited by siRNA-PLTP.

CONCLUSION

PLTP may be involved in CSE induced EMT of rat alveolar cells.

Development and characterization of microsatellite loci in Brasenia schreberi (Cabombaceae) based on the next-generation sequencing

To understand genetic variability of the endangered aquatic herb Brasenia schreberi (Cabombaceae), we describe 31 microsatellite markers obtained using next-generation sequencing. A total of 24 individuals from the population of Jackson Lake, USA, were genotyped for each marker. Twenty-eight markers were polymorphic. The number of alleles per locus ranged from 1 to 9; the observed and expected heterozygosities ranged from 0 to 1 and from 0 to 0.751, respectively. These markers should be useful tools for genetic variation and conservation studies of B. schreberi.

Cationic Silicon Nanocrystals with Colloidal Stability, pH-Independent Positive Surface Charge and Size Tunable Photoluminescence in the Near-Infrared to Red Spectral Range

In this report, the synthesis of a novel class of cationic quaternary ammonium-surface-functionalized silicon nanocrystals (ncSi) using a novel and highly versatile terminal alkyl halide-surface-functionalized ncSi synthon is described. The distinctive features of these cationic ncSi include colloidal stability, pH-independent positive surface charge, and size-tunable photoluminescence (PL) in the biologically relevant near-infrared-to-red spectral region. These cationic ncSi are characterized via a combination of high-resolution scanning transmission electron microscopy with energy-dispersive X-ray analysis, Fourier transform infrared, X-ray photoelectron, and photoluminescence spectroscopies, and zeta potential measurements.

Silencing NFBD1/MDC1 enhances the radiosensitivity of human nasopharyngeal cancer CNE1 cells and results in tumor growth inhibition

NFBD1 functions in cell cycle checkpoint activation and DNA repair following ionizing radiation (IR). In this study, we defined the NFBD1 as a tractable molecular target to radiosensitize nasopharyngeal carcinoma (NPC) cells. Silencing NFBD1 using lentivirus-mediated shRNA-sensitized NPC cells to radiation in a dose-dependent manner, increasing apoptotic cell death, decreasing clonogenic survival and delaying DNA damage repair. Furthermore, downregulation of NFBD1 inhibited the amplification of the IR-induced DNA damage signal, and failed to accumulate and retain DNA damage-response proteins at the DNA damage sites, which leaded to defective checkpoint activation following DNA damage. We also implicated the involvement of NFBD1 in IR-induced Rad51 and DNA-dependent protein kinase catalytic subunit foci formation. Xenografts models in nude mice showed that silencing NFBD1 significantly enhanced the antitumor activity of IR, leading to tumor growth inhibition of the combination therapy. Our studies suggested that a combination of gene therapy and radiation therapy may be an effective strategy for human NPC treatment.

Activation of Ultrathin Films of Hematite for Photoelectrochemical Water Splitting via H2 Treatment

Thermal treatment of ultrathin films of hematite (α-Fe2 O3 ) under an atmosphere of 5 % H2 in Ar is presented as a means of activating α-Fe2 O3 towards the photoelectrochemical splitting of water. Spin-coated films annealed in air exhibited no photoactivity, whereas films treated in hydrogen exhibited a photocurrent response. X-ray photoelectron spectroscopy and UV/Vis absorption spectroscopy results showed that the H2 -treated films contain oxygen vacancies, which suggests improved charge transport. However, Tafel slopes, scan-rate dependent measurements, and kinetic analyses performed by using H2 O2 as a hole scavenger suggested that surface modification may also contribute to their induced photoactivity. Electrochemical impedance spectroscopy results revealed the buildup of a surface trap capacitance at the point of photocurrent onset for the hydrogen-treated films under illumination. A decrease in charge trapping resistance was also observed, which suggests improved transport of charges away from the surface.

Morphology-controlled In2O3 nanostructures enhance the performance of photoelectrochemical water oxidation

Nanotower- and nanowall-like indium oxide structures were grown directly on fluorine-doped tin oxide (FTO)/In2O3 seeded substrates and pristine FTO substrates, respectively, by a straightforward solvothermal method. The tower-like nanostructures are proposed to form via a self-assembly process on the In2O3 seeds. The wall-like nanostructures are proposed to form via epitaxial growth from the exposed edges of SnO2 crystals of the FTO substrate. The nanotowers and nanowalls are composed of highly crystalline and ordered nanocrystals with preferred orientations in the [111] and [110] directions, respectively. The two structures display remarkably different activities when used as photoanodes in solar light-driven water splitting. X-ray photoelectron spectroscopy results suggest an increased density of hydroxyl groups in the nanowalls, which results in a decrease of the work function and a concomitant shift in the onset potential of the photocurrent in the linear sweep voltammograms, which is further confirmed by Mott-Schottky and flat-band potential measurements, indicating the importance of hydroxyl content in determining the photoelectrochemical properties of the films. Morphology-controlled, nanostructured transparent conducting oxide electrodes of the kind described in this paper are envisioned to provide valuable platforms for supporting catalysts and co-catalysts that are intentionally tailored for efficient light-assisted oxidation of water and reduction of carbon dioxide.

The Rational Design of a Single-Component Photocatalyst for Gas-Phase CO2 Reduction Using Both UV and Visible Light

The solar-to-chemical energy conversion of greenhouse gas CO₂ into carbon-based fuels is a very important research challenge, with implications for both climate change and energy security. Herein, the key attributes of hydroxides and oxygen vacancies are experimentally identified in non-stoichiometric indium oxide nanoparticles, In₂O_3-x(OH)_y, that function in concert to reduce CO₂ to CO under simulated solar irradiation.