Resistance of non-transgenic papaya plants to papaya ringspot virus (PRSV) mediated by intron-containing hairpin dsRNAs expressed in bacteria

RNA-mediated virus resistance based on natural antiviral RNA silencing has been exploited as a powerful tool for engineering virus resistance in plants. In this study, a conserved 3'-region (positions 9839-10117, 279 nt) of the capsid protein (CP) gene of papaya ringspot virus (PRSV), designated CP279, was used to generate an intron-containing hairpin RNA (ihpRNA) construct by one-step, zero-background ligation-independent cloning (OZ-LIC). The RNaseIII-deficient Escherichia coli strain M-JM109lacY was identified as the best choice for producing large quantities of specific ihpRNA-CP279. Resistance analyses and ELISA data verified that most papaya plants mechanically co-inoculated with TRIzol-extracted ihpRNA-CP279 and PRSV were resistant to PRSV, and resistance was maintained throughout the test period (>2 months post-inoculation). In contrast, a 1-2 day interval between sequential inoculation of PRSV and ihpRNA-CP279 did not result in complete protection against PRSV infection, but delayed the appearance of viral symptoms by 3 to 4 days. These findings indicate that direct mechanical inoculation of papaya plants with bacterially-expressed ihpRNA-CP279 targeting the PRSV CP gene can interfere with virus infection. This work lays a foundation for developing a non-transgenic approach to control PRSV by directly spraying plants with ihpRNA or crude bacterial extract preparations.

Itching is a significant problem and a mediator between disease severity and quality of life for patients with psoriasis: results from a randomized controlled trial

BACKGROUND

In patients with moderate-to-severe psoriasis, health-related quality of life (HRQOL) has been shown to improve in parallel with improvement in disease severity.

OBJECTIVES

To evaluate the role of pruritus (itch) in mediating the relationship between improvements in disease severity and HRQOL.

METHODS

Data from a phase 2 clinical trial, in which 142 patients with moderate-to-severe plaque psoriasis received ixekizumab or placebo, were used for this posthoc analysis. Relationships between improvement in Psoriasis Area and Severity Index (PASI), Itch Visual Analogue Scale (VAS) and Dermatology Life Quality Index (DLQI), as well as in individual DLQI domains (symptoms and feelings, treatment, work and school, daily activities, leisure, and personal relationships) from baseline to week 16 were determined. Multiple hierarchical linear regressions and Sobel tests were conducted to evaluate the results.

RESULTS

Improvement in PASI was highly correlated with pruritus improvement and improvements in DLQI total and domain scores at week 16 (P < 0·01). Multiple hierarchical linear regression analyses showed a statistically significant (P < 0·01) association between improvement in pruritus and improvement in DLQI total score and each of the six DLQI domain scores after adjusting for improvement in PASI. Sobel tests indicated that pruritus had a significant mediation effect (P < 0·05) on the association of PASI improvement with improvement in DLQI total score and all domains except the personal relationships score.

CONCLUSIONS

Pruritus appears to be an important mediator of the association between improvements in disease severity and HRQOL in patients with moderate-to-severe psoriasis.

Effect of once-daily tadalafil on confidence and perceived difficulty in performing sexual intercourse in men who were incomplete responders to as-needed PDE5 inhibitor treatment

INTRODUCTION

For men with erectile dysfunction (ED), the expectation of difficulty and level of confidence in achieving and maintaining an erection have an impact on sexual performance.

OBJECTIVE AND METHODS

This 12-week, double-blind study investigated once-daily tadalafil (2.5 mg titrated to 5 mg or 5 mg) (n = 176) or placebo (n = 79) on confidence and perceived difficulty in performing sexual intercourse in men with ED who were incomplete responders to as-needed phosphodiesterase-5 inhibitor therapy. The Confidence in Performing Sexual Intercourse Questionnaire (CPSIQ) and Difficulty in Performing Sexual Intercourse Questionnaire (DPSIQ) were administered at baseline and 12 weeks.

RESULTS

The mean change in CPSIQ for the tadalafil group was 1.8, which represents a shift from 'very low' to 'moderate' sexual confidence vs. a mean change of 0.5 in the placebo group (p < 0.0001). The mean change in DPSIQ for tadalafil was 1.6, which represents a shift from 'very difficult' to 'moderately' or 'slightly difficult' sexual performance vs. a mean change of 0.4 in the placebo group (p < 0.0001). Among men receiving tadalafil with an International Index of Erectile Function-Erectile Function (IIEF-EF) end-point score of ≥ 26 or who achieved a minimal clinically important difference in IIEF-EF score at end-point, the mean changes in CPSIQ were 3.0 and 2.4, respectively (both p < 0.0001).

CONCLUSION

Once-daily tadalafil vs. placebo improves confidence and decreases difficulty in performing sexual intercourse for men with ED who were incomplete responders to as-needed PDE5 inhibitor therapy.

Weight loss composition is one-fourth fat-free mass: a critical review and critique of this widely cited rule

Maximizing fat loss while preserving lean tissue mass and function is a central goal of modern obesity treatments. A widely cited rule guiding expected loss of lean tissue as fat-free mass (FFM) states that approximately one-fourth of weight loss will be FFM (i.e. ΔFFM/ΔWeight = ∼0.25), with the remaining three-fourths being fat mass. This review examines the dynamic relationships between FFM, fat mass and weight changes that follow induction of negative energy balance with hypocaloric dieting and/or exercise. Historical developments in the field are traced with the 'Quarter FFM Rule' used as a framework to examine evolving concepts on obesity tissue, excess weight and what is often cited as 'Forbes' Rule'. Temporal effects in the fractional contribution of FFM to changes in body weight are examined as are lean tissue moderating effects such as ageing, inactivity and exercise that frequently accompany structured low-calorie diet weight loss protocols. Losses of lean tissue with dieting typically tend to be small, raising questions about study design, power and applied measurement method reliability. Our review elicits important questions related to the fractional loss of lean tissues with dieting and provides a foundation for future research on this topic.

Degradation of acetochlor by a bacterial consortium of Rhodococcus sp.T3-1, Delftia sp.T3-6 and Sphingobium sp.MEA3-1

Owing to acetochlor persistence in the environment and its perceptible threats to the ecosystem and human health, it is urgent to search for effective approaches to decontaminate acetochlor. In this study, an acetochlor-degrading enrichment culture was obtained by continuous enrichment from acetochlor-contaminated soil and named T3. T3 could completely degrade 100 mg l(-1) acetochlor and butachlor within 6 days. Two bacterial strains Rhodococcus sp.T3-1 and Delftia sp.T3-6 and one strain Sphingobium sp.MEA3-1 were isolated and identified from T3 by using acetochlor and MEA as sole carbon source, respectively. These three bacteria could completely mineralize acetochlor by the cooperative metabolism. The biochemical pathway of acetochlor degradation by these three bacteria in a consortium was proposed: acetochlor to 2'-methyl-6'-ethyl-2-chloroacetanilide (CMEPA) by Rhodococcus sp. T3-1, CMEPA to 2-methyl-6-ethyl aniline (MEA) by Delftia sp.T3-6 and MEA by Sphingobium sp.MEA3-1 based on the identified degradation intermediates. Under laboratory conditions, the consortium was effective in the acetochlor mineralization.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study presents a bacterial consortium consisting of Rhodococcus sp.T3-1, Delftia sp.T3-6 and Sphingobium sp.MEA3-1 could completely mineralize acetochlor by biochemical cooperation. The study reveals the metabolic mechanism of acetochlor biodegradation and highlights the potential of the bacterial consortium for cleaning up acetochlor and its metabolites subsisting in the environment.

Complete genome sequence of an isolate of papaya leaf distortion mosaic virus from commercialized PRSV-resistant transgenic papaya in China

Papaya leaf distortion mosaic virus is highly destructive to commercial papaya production. Here, the complete genome sequence was determined for an isolate of papaya leaf distortion mosaic virus, designated PLDMV-DF, infecting the commercialized papaya ringspot virus (PRSV)-resistant transgenic papaya from China. Excluding the 3'-poly (A) tail, the sequence shares high sequence identity to several PLDMV isolates from Taiwan and Japan and is phylogenetically most closely related to the isolate from Japan. Infection of PLDMV-DF in transgenic PRSV-resistant papaya may indicate emergence of this disease in genetically engineered plants. The reported sequence for this isolate may help generate bi-transgenic papaya resistant to PRSV and PLDMV.

Deficiency of antithrombin and protein C gene in 202 Chinese venous thromboembolism patients

INTRODUCTION

Antithrombin and protein C gene deficiencies are commonly inherited risk factors for VTE patients. We aim to investigate the deficiency of these two gene in 202 Chinese patients with venous thromboembolism (VTE).

METHODS

Antithrombin activity (AT: A) and protein C activity (PC: A) were measured in 202 VTE patients, and for those with unexplainable low results, PCR and direct sequencing of the related genes were carried out.

RESULTS

Deficiency levels of antithrombin and protein C gene were found to be 2% and 8%, respectively. AT or PC hereditary deficiency can be found in 10% patients with VTE.

CONCLUSION

Protein C gene deficiency might be more prevalent than AT gene deficiency in Chinese VTE patients. Functional assay combined with genetic analysis is useful in the diagnosis of inherited defects in VTE patients.

Exploration of microfluidic devices based on multi-filament threads and textiles: A review

In this paper, we review the recent progress in the development of low-cost microfluidic devices based on multifilament threads and textiles for semi-quantitative diagnostic and environmental assays. Hydrophilic multifilament threads are capable of transporting aqueous and non-aqueous fluids via capillary action and possess desirable properties for building fluid transport pathways in microfluidic devices. Thread can be sewn onto various support materials to form fluid transport channels without the need for the patterned hydrophobic barriers essential for paper-based microfluidic devices. Thread can also be used to manufacture fabrics which can be patterned to achieve suitable hydrophilic-hydrophobic contrast, creating hydrophilic channels which allow the control of fluids flow. Furthermore, well established textile patterning methods and combination of hydrophilic and hydrophobic threads can be applied to fabricate low-cost microfluidic devices that meet the low-cost and low-volume requirements. In this paper, we review the current limitations and shortcomings of multifilament thread and textile-based microfluidics, and the research efforts to date on the development of fluid flow control concepts and fabrication methods. We also present a summary of different methods for modelling the fluid capillary flow in microfluidic thread and textile-based systems. Finally, we summarized the published works of thread surface treatment methods and the potential of combining multifilament thread with other materials to construct devices with greater functionality. We believe these will be important research focuses of thread- and textile-based microfluidics in future.

The role of sequential 18(F) -FDG PET/CT in predicting tumour response after preoperative chemoradiation for rectal cancer

AIM

The aim of this study was to investigate the potential of sequential positron emission tomography (PET)/CT standardized uptake value (SUV)/metabolic area variation in predicting the pathological response to preoperative chemoradiotherapy (CRT) for rectal cancer.

METHOD

Fifty-three patients diagnosed with clinical T3-4 and/or N+ rectal cancer were enrolled. All patients received CRT followed by radical surgery after 6-8 weeks. A PET/CT scan was performed before (PET/CT1) initiation of treatment and a second scan (PET/CT2) was performed within 1 week after the completion of CRT. Thirty-five of 53 patients also underwent a third (PET/CT3) scan within 1 week before surgery. Maximal SUV within the tumour (SUVmax), average SUV within the tumour (SUVmean), metabolic tumour volume (MV), total lesion glycolysis (TLG) and response indices (∆%, i.e. the percentage difference between two different PET/CT scans for SUVmax, SUVmean, MV and TLG) were calculated. The different metabolic parameters were analysed and correlated with the tumour regression grade (TRG) score.

RESULTS

When patients were regrouped as responders (TRG 3-4) and nonresponders (TRG 0-2), significant differences were observed in the percentage differences between PET/CT1 and PET/CT3 for MV (∆%MV(1-3); 91.08% vs 75.43%) and for TLG (∆%TLG(1-3); 94.00% vs 82.02%). As demonstrated by receiver-operating characteristics analysis, ∆%MV(1-3) and ∆%TLG(1-3) both had a strong capability to discriminate between responders and nonresponders. Patients classified as having a pathological complete response (pCR) and a non-pCR showed significant differences in the percentage difference between PET/CT1 and PET/CT3 in SUVmax (∆% SUVmax(1-3); 69.17% vs 57.77%), SUVmean (∆% SUVmean(1-3); 44.20% vs 30.19%), ∆%MV(1-3) (90.93% vs 80.30%) and ∆%TLG(1-3) (94.22% vs 85.63%). ∆%TLG (1-3) was a more powerful discriminator than the others.

CONCLUSION

Differences in the SUV/metabolic area with 18F-fluorodeoxyglucose (18(F) -FDG) PET/CT have the potential to predict a response to preoperative CRT for rectal cancer.

Discovery and characterization of LY2784544, a small-molecule tyrosine kinase inhibitor of JAK2V617F

Owing to the prevalence of the JAK2V617F mutation in myeloproliferative neoplasms (MPNs), its constitutive activity, and ability to recapitulate the MPN phenotype in mouse models, JAK2V617F kinase is an attractive therapeutic target. We report the discovery and initial characterization of the orally bioavailable imidazopyridazine, LY2784544, a potent, selective and ATP-competitive inhibitor of janus kinase 2 (JAK2) tyrosine kinase. LY2784544 was discovered and characterized using a JAK2-inhibition screening assay in tandem with biochemical and cell-based assays. LY2784544 in vitro selectivity for JAK2 was found to be equal or superior to known JAK2 inhibitors. Further studies showed that LY2784544 effectively inhibited JAK2V617F-driven signaling and cell proliferation in Ba/F3 cells (IC₅₀=20 and 55 nM, respectively). In comparison, LY2784544 was much less potent at inhibiting interleukin-3-stimulated wild-type JAK2-mediated signaling and cell proliferation (IC₅₀=1183 and 1309 nM, respectively). In vivo, LY2784544 effectively inhibited STAT5 phosphorylation in Ba/F3-JAK2V617F-GFP (green fluorescent protein) ascitic tumor cells (TED₅₀=12.7 mg/kg) and significantly reduced (P<0.05) Ba/F3-JAK2V617F-GFP tumor burden in the JAK2V617F-induced MPN model (TED₅₀=13.7 mg/kg, twice daily). In contrast, LY2784544 showed no effect on erythroid progenitors, reticulocytes or platelets. These data suggest that LY2784544 has potential for development as a targeted agent against JAK2V617F and may have properties that allow suppression of JAK2V617F-induced MPN pathogenesis while minimizing effects on hematopoietic progenitor cells.

Discovery and characterization of LY2784544, a small-molecule tyrosine kinase inhibitor of JAK2V617F

Owing to the prevalence of the JAK2V617F mutation in myeloproliferative neoplasms (MPNs), its constitutive activity, and ability to recapitulate the MPN phenotype in mouse models, JAK2V617F kinase is an attractive therapeutic target. We report the discovery and initial characterization of the orally bioavailable imidazopyridazine, LY2784544, a potent, selective and ATP-competitive inhibitor of janus kinase 2 (JAK2) tyrosine kinase. LY2784544 was discovered and characterized using a JAK2-inhibition screening assay in tandem with biochemical and cell-based assays. LY2784544 in vitro selectivity for JAK2 was found to be equal or superior to known JAK2 inhibitors. Further studies showed that LY2784544 effectively inhibited JAK2V617F-driven signaling and cell proliferation in Ba/F3 cells (IC50=20 and 55 nM, respectively). In comparison, LY2784544 was much less potent at inhibiting interleukin-3-stimulated wild-type JAK2-mediated signaling and cell proliferation (IC50=1183 and 1309 nM, respectively). In vivo, LY2784544 effectively inhibited STAT5 phosphorylation in Ba/F3-JAK2V617F-GFP (green fluorescent protein) ascitic tumor cells (TED50=12.7 mg/kg) and significantly reduced (P<0.05) Ba/F3-JAK2V617F-GFP tumor burden in the JAK2V617F-induced MPN model (TED50=13.7 mg/kg, twice daily). In contrast, LY2784544 showed no effect on erythroid progenitors, reticulocytes or platelets. These data suggest that LY2784544 has potential for development as a targeted agent against JAK2V617F and may have properties that allow suppression of JAK2V617F-induced MPN pathogenesis while minimizing effects on hematopoietic progenitor cells.

Identifying the target NSCLC patient for maintenance therapy: an analysis from a placebo-controlled, phase III trial of maintenance pemetrexed (H3E-MC-JMEN)

Background

This was a post hoc analysis of patients with non-squamous histology from a phase III maintenance pemetrexed study in advanced non-small cell lung cancer (NSCLC).

Patients and methods

The six symptom items' [average symptom burden index (ASBI)] mean at baseline was calculated using the lung cancer symptom scale (LCSS). Low and high symptom burden (LSB, ASBI < 25; HSB, ASBI ≥ 25) and performance status (PS: 0, 1) subgroups were analyzed for treatment effect on progression-free survival (PFS) and overall survival (OS) using the Cox proportional hazard models adjusted for demographic/clinical factors.

Results

Significantly longer PFS and OS for pemetrexed versus placebo occurred in LSB patients [PFS: median 5.1 versus 2.4 months, hazard ratio (HR) 0.49, P < 0.0001; OS: median 17.5 versus 11.0 months, HR 0.63, P = 0.0012] and PS 0 patients (PFS: median 5.5 versus 1.7 months, HR 0.36, P < 0.0001; OS: median 17.7 versus 10.3 months, HR 0.54, P = 0.0019). Significantly longer PFS, but not OS, occurred in HSB patients (median 3.7 versus 2.8 months, HR 0.50, P = 0.0033) and PS 1 patients (median 4.4 versus 2.8 months, HR 0.60, P = 0.0002).

Conclusions

ASBI and PS are associated with survival for non-squamous NSCLC patients, suggesting that maintenance pemetrexed is useful for LSB or PS 0 patients following induction.