Methods: The assay system utilized a known NS2B/NS3 peptide substrate, a recombinant of NS2B/NS3 protease with proprietary StrepTactin® donor and nickel chelate acceptor beads in 384-well format.
Results: The optimized assay to screen for NS2B/NS3 protease inhibitors was demonstrated to be potentially useful with reasonable z' factor, coefficient variance and signal to background ratio. However, screening of synthesized thioguanine derivatives using the optimized AlphaScreen® assay revealed weak NS2B/NS3 inhibition activities.
Conclusion: The AlphaScreen® assay to screen for NS2B/NS3 protease inhibitors is potentially applicable for high throughput screening.
RESULTS: The host counter-attack was evidenced based on fungal hyphae and Ganoderma DNA observed at 3 d.p.i which became significantly reduced at 7 and 11 d.p.i. DEGs revealed upregulation of multifaceted defense related genes such as PR-protein (EgPR-1), protease inhibitor (EgBGIA), PRR protein (EgLYK3) chitinase (EgCht) and expansin (EgEXPB18) at 3 d.p.i and 7 d.p.i which dropped at 11 d.p.i. Later stage involved highly expressed transcription factors EgERF113 and EgMYC2 as potential regulators of necrotrophic defense at 11 d.p.i. The reactive oxygen species (ROS) elicitor: peroxidase (EgPER) and NADPH oxidase (EgRBOH) were upregulated and maintained throughout the treatment period. Growth and nutrient distribution were probably compromised through suppression of auxin signalling and iron uptake genes.
CONCLUSIONS: Based on the analysis of oil palm gene expression, it was deduced that the biotrophic phase of Ganoderma had possibly occurred at the early phase (3 until 7 d.p.i) before being challenged by the fungus via switching its lifestyle into the necrotrophic phase at later stage (11 d.p.i) and finally succumbed the host. Together, the findings suggest the dynamic defense process in oil palm and potential candidates that can serve as phase-specific biomarkers at the early stages of oil palm-G. boninense interaction.
METHODS: Of the 37 sites that participated in the randomised, open-label, non-inferiority SECOND-LINE study, eight sites from five countries (Argentina, India, Malaysia, South Africa, and Thailand) participated in the body composition substudy. All sites had a dual energy x-ray absorptiometry (DXA) scanner and all participants enrolled in SECOND-LINE were eligible for inclusion in the substudy. Participants were randomly assigned (1:1), via a computer-generated allocation schedule, to receive either ritonavir-boosted lopinavir plus raltegravir (raltegravir group) or ritonavir-boosted lopinavir plus two or three N(t)RTIs (N[t]RTI group). Randomisation was stratified by site and screening HIV-1 RNA. Participants and investigators were not masked to group assignment, but allocation was concealed until after interventions were assigned. DXA scans were done at weeks 0, 48, and 96. The primary endpoint was mean percentage and absolute change in peripheral limb fat from baseline to week 96. We did intention-to-treat analyses of available data. This substudy is registered with ClinicalTrials.gov, number NCT01513122.
FINDINGS: Between Aug 1, 2010, and July 10, 2011, we recruited 211 participants into the substudy. The intention-to-treat population comprised 102 participants in the N(t)RTI group and 108 participants in the raltegravir group, of whom 91 and 105 participants, respectively, reached 96 weeks. Mean percentage change in limb fat from baseline to week 96 was 16·8% (SD 32·6) in the N(t)RTI group and 28·0% (37·6) in the raltegravir group (mean difference 10·2%, 95% CI 0·1-20·4; p=0·048). Mean absolute change was 1·04 kg (SD 2·29) in the N(t)RTI group and 1·81 kg (2·50) in the raltegravir group (mean difference 0·6, 95% CI -0·1 to 1·3; p=0·10).
INTERPRETATION: Our findings suggest that for people with virological failure of a first-line regimen containing efavirenz plus tenofovir and lamivudine or emtricitabine, the WHO-recommended switch to a ritonavir-boosted protease inhibitor plus zidovudine (a thymidine analogue nucleoside reverse transcriptase inhibitor) and lamivudine might come at the cost of peripheral lipoatrophy. Further study could help to define specific groups of people who might benefit from a switch to an N(t)RTI-sparing second-line ART regimen.
FUNDING: The Kirby Institute and the Australian National Health and Medical Research Council.
METHODS: We included 446 SARS-CoV-2 RT-PCR-positive patients taking at least one treatment drug for COVID-19 within a period of one month (March-April 2020). In addition to COVID-19-related treatment (HCQ/PI), concomitant drugs with risks of QTc prolongation were considered. We defined QTc prolongation as QTc interval of ≥470 ms in postpubertal males, and ≥480 ms in postpubertal females.
RESULTS AND DISCUSSION: QTc prolongation events occurred in 28/446 (6.3%) patients with an incidence rate of 1 case per 100 person-days. A total of 26/28 (93%) patients who had prolonged QTc intervals received at least two pro-QT drugs. Multivariate analysis showed that HCQ and PI combination therapy had five times higher odds of QTc prolongation as compared to HCQ-only therapy after controlling for age, cardiovascular disease, SIRS and the use of concurrent QTc-prolonging agents besides HCQ and/or PI (OR 5.2; 95% CI, 1.11-24.49; p = 0.036). Independent of drug therapy, presence of SIRS resulted in four times higher odds of QTc prolongation (OR 4.3; 95% CI, 1.66-11.06; p = 0.003). In HCQ-PI combination group, having concomitant pro-QT drugs led to four times higher odds of QTc prolongation (OR 3.8; 95% CI, 1.53-9.73; p = 0.004). Four patients who had prolonged QTc intervals died but none were cardiac-related deaths.
WHAT IS NEW AND CONCLUSION: In our cohort, hydroxychloroquine monotherapy had low potential to increase QTc intervals. However, when given concurrently with protease inhibitors which have possible or conditional risk, the odds of QTc prolongation increased fivefold. Interestingly, independent of drug therapy, the presence of systemic inflammatory response syndrome (SIRS) resulted in four times higher odds of QTc prolongation, leading to the postulation that some QTc events seen in COVID-19 patients may be due to the disease itself. ECG monitoring should be continued for at least a week from the initiation of treatment.