In low-resource settings, resilience to infectious disease outbreaks can be hindered by limited access to diagnostic tests. Here we report the results of double-blinded studies of the performance of paper-based diagnostic tests for the Zika and chikungunya viruses in a field setting in Latin America. The tests involved a cell-free expression system relying on isothermal amplification and toehold-switch reactions, a purpose-built portable reader and onboard software for computer vision-enabled image analysis. In patients suspected of infection, the accuracies and sensitivities of the tests for the Zika and chikungunya viruses were, respectively, 98.5% (95% confidence interval, 96.2–99.6%, 268 serum samples) and 98.5% (95% confidence interval, 91.7–100%, 65 serum samples) and approximately 2 aM and 5 fM (both concentrations are within clinically relevant ranges). The analytical specificities and sensitivities of the tests for cultured samples of the viruses were equivalent to those of the real-time quantitative PCR. Cell-free synthetic biology tools and companion hardware can provide de-centralized, high-capacity and low-cost diagnostics for use in low-resource settings.
Insecticide resistant Aedes populations have recently been reported in Pakistan, imposing a threat to their control. We aimed to evaluate the susceptibility of Aedes aegypti and Aedes albopictus populations from Lahore to WHO-recommended insecticides and to investigate metabolic and target-site resistance mechanisms. For this purpose, we first carried out bioassays with the larvicides temephos and pyriproxyfen, and the adulticides malathion, permethrin, deltamethrin, alpha-cypermethrin, and etofenprox. We looked for Knockdown resistance mutations (kdr) by qPCR, High-Resolution Melt (HRM), and sequencing. In order to explore the role of detoxifying enzymes in resistance, we carried out synergist bioassay with both species and then checked the expression of CYP9M6, CYP9J10, CYP9J28, CYP6BB2, CCAe3a, and SAP2 genes in Ae. aegypti. Both species were susceptible to organophosphates and the insect growth regulator, however resistant to all pyrethroids. We are reporting the kdr haplotypes 1520Ile + 1534Cys and T1520 + 1534Cys in high frequencies in Ae. aegypti while Ae. albopictus only exhibited the alteration L882M. PBO increased the sensitivity to permethrin in Ae. aegypti, suggesting the participation of P450 genes in conferring resistance, and indeed, CYP928 was highly expressed. We presume that dengue vectors in Lahore city are resistant to pyrethroids, probably due to multiple mechanisms, such as kdr mutations and P450 overexpression.
This study represents the first phytochemical analysis of Stillingia loranthacea (S. loranthacea) and describes new terpenoids obtained from the root bark of this species. The fractionation of the hexane extract from the root bark led to the isolation of two new 28-nor-taraxarenes derivatives, loranthones A and B (1 and 2), four new tigliane diterpenes (5−8), three known tigliane diterpenes (9−11), and three known flexibilene diterpenes, tonantzitlolones A−C (12−14). The investigation of these compounds and the use of a molecular networking-based prioritization approach afforded two other new 28-nor-taraxarenes, loranthones C and D (3 and 4). The cytotoxicity of compounds 1, 2, and 5−14 was evaluated against Vero cells, and their 20% cytotoxic concentration (CC 20 ) values varied from 8.7 to 328 μM; antiviral activity was tested against an epidemic Zika virus (ZIKV) strain circulating in Brazil. Six out of 12 compounds (2, 5, 9−11, and 14) exhibited significant antiviral effects against ZIKV. Specifically, compounds 2 and 5 offered the most promise as lead compounds as they had a 1.7 and 1.8 log 10 TCID 50 /mL reduction in ZIKV replication, respectively. Together, the present findings have identified S. loranthacea terpenoids as potent anti-ZIKV inhibitors and pave the way to the development of possible new treatments against this devastating pathogen.
Alpha and beta particulate radiation are used for non-treated neoplasia, due to their ability to reach and remain in tumor sites. Radium-223 (223Ra), an alpha emitter, promotes localized cytotoxic effects, while radioactive gold (198Au), beta-type energy, reduces radiation in the surrounding tissues. Nanotechnology, including several radioactive nanoparticles, can be safely and effectively used in cancer treatment. In this context, this study aims to analyze the antitumoral effects of [223Ra]Ra nanomicelles co-loaded with radioactive gold nanoparticles ([198Au]AuNPs). For this, we synthesize and characterize nanomicelles, as well as analyze some parameters, such as particle size, radioactivity emission, dynamic light scattering, and microscopic atomic force. [223Ra]Ra nanomicelles co-loaded with [198Au]AuNPs, with simultaneous alpha and beta emission, showed no instability, a mean particle size of 296 nm, and a PDI of 0.201 (±0.096). Furthermore, nanomicelles were tested in an in vitro cytotoxicity assay. We observed a significant increase in tumor cell death using combined alpha and beta therapy in the same formulation, compared with these components used alone. Together, these results show, for the first time, an efficient association between alpha and beta therapies, which could become a promising tool in the control of tumor progression.
<p>In low-resource settings, resilience to infectious disease outbreaks can be hindered by limited access to diagnostic tests. Here we report the results of double-blinded studies of the performance of paper-based diagnostic tests for the Zika and chikungunya viruses in a field setting in Latin America. The tests involved a cell-free expression system relying on isothermal amplification and toehold-switch reactions, a purpose-built portable reader and onboard software for computer vision-enabled image analysis. In patients suspected of infection, the accuracies and sensitivities of the tests for the Zika and chikungunya viruses were, respectively, 98.5% (95% confidence interval, 96.2-99.6%, 268 serum samples) and 98.5% (95% confidence interval, 91.7-100%, 65 serum samples) and approximately 2 aM and 5 fM (both concentrations are within clinically relevant ranges). The analytical specificities and sensitivities of the tests for cultured samples of the viruses were equivalent to those of the real-time quantitative PCR. Cell-free synthetic biology tools and companion hardware can provide de-centralized, high-capacity and low-cost diagnostics for use in low-resource settings.</p> <p>Double-blinded studies show that paper-based diagnostic tests and a companion portable device designed for use in low-resource settings perform well for the diagnosis of the Zika and chikungunya viruses in serum samples.</p>
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