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Fulltext Coordination of apicoplast transcription in a malaria parasite by internal and host cues

Kobayashi Y, Komatsuya K, Imamura S, Nozaki T, Watanabe YI, Sato S, et al.

Proc Natl Acad Sci U S A, 2023 Jul 11;120(28):e2214765120.
PMID: 37406097 DOI: 10.1073/pnas.2214765120

The malaria parasite Plasmodium falciparum has a nonphotosynthetic plastid called the apicoplast, which contains its own genome. Regulatory mechanisms for apicoplast gene expression remain poorly understood, despite this organelle being crucial for the parasite life cycle. Here, we identify a nuclear-encoded apicoplast RNA polymerase σ subunit (sigma factor) which, along with the α subunit, appears to mediate apicoplast transcript accumulation. This has a periodicity reminiscent of parasite circadian or developmental control. Expression of the apicoplast subunit gene, apSig, together with apicoplast transcripts, increased in the presence of the blood circadian signaling hormone melatonin. Our data suggest that the host circadian rhythm is integrated with intrinsic parasite cues to coordinate apicoplast genome transcription. This evolutionarily conserved regulatory system might be a future target for malaria treatment.
Fulltext Use of headspace-gas chromatography-ion mobility spectrometry to detect volatile fingerprints of palm fibre oil and sludge palm oil in samples of crude palm oil

Othman A, Goggin KA, Tahir NI, Brodrick E, Singh R, Sambanthamurthi R, et al.

BMC Res Notes, 2019 Apr 16;12(1):229.
PMID: 30992056 DOI: 10.1186/s13104-019-4263-7

OBJECTIVE: The addition of residual oils such as palm fibre oil (PFO) and sludge palm oil (SPO) to crude palm oil (CPO) can be problematic within supply chains. PFO is thought to aggravate the accumulation of monochloropropanediols (MCPDs) in CPO, whilst SPO is an acidic by-product of CPO milling and is not fit for human consumption. Traditional targeted techniques to detect such additives are costly, time-consuming and require highly trained operators. Therefore, we seek to assess the use of gas chromatography-ion mobility spectrometry (GC-IMS) for rapid, cost-effective screening of CPO for the presence of characteristic PFO and SPO volatile organic compound (VOC) fingerprints.
RESULTS: Lab-pressed CPO and commercial dispatch tank (DT) CPO were spiked with PFO and SPO, respectively. Both additives were detectable at concentrations of 1% and 10% (w/w) in spiked lab-pressed CPO, via seven PFO-associated VOCs and 21 SPO-associated VOCs. DT controls could not be distinguished from PFO-spiked DT CPO, suggesting these samples may have already contained low levels of PFO. DT controls were free of SPO. SPO was detected in all SPO-spiked dispatch tank samples by all 21 of the previously distinguished VOCs and had a significant fingerprint consisting of four spectral regions.
Fulltext Circadian oscillations of cytosolic free calcium regulate the Arabidopsis circadian clock

Martí Ruiz MC, Hubbard KE, Gardner MJ, Jung HJ, Aubry S, Hotta CT, et al.

Nat Plants, 2018 Sep;4(9):690-698.
PMID: 30127410 DOI: 10.1038/s41477-018-0224-8

In the last decade, the view of circadian oscillators has expanded from transcriptional feedback to incorporate post-transcriptional, post-translational, metabolic processes and ionic signalling. In plants and animals, there are circadian oscillations in the concentration of cytosolic free Ca2+ ([Ca2+]cyt), though their purpose has not been fully characterized. We investigated whether circadian oscillations of [Ca2+]cyt regulate the circadian oscillator of Arabidopsis thaliana. We report that in Arabidopsis, [Ca2+]cyt circadian oscillations can regulate circadian clock function through the Ca2+-dependent action of CALMODULIN-LIKE24 (CML24). Genetic analyses demonstrate a linkage between CML24 and the circadian oscillator, through pathways involving the circadian oscillator gene TIMING OF CAB2 EXPRESSION1 (TOC1).
Fulltext Development and implementation of a potential coronavirus disease 2019 (COVID-19) vaccine: A systematic review and meta-analysis of vaccine clinical trials

Sathian B, Asim M, Banerjee I, Roy B, Pizarro AB, Mancha MA, et al.

Nepal J Epidemiol, 2021 Mar;11(1):959-982.
PMID: 33868742 DOI: 10.3126/nje.v11i1.36163

Background: To date, there is no comprehensive systematic review and meta-analysis to assess the suitability of COVID-19 vaccines for mass immunization. The current systematic review and meta-analysis was conducted to evaluate the safety and immunogenicity of novel COVID-19 vaccine candidates under clinical trial evaluation and present a contemporary update on the development and implementation of a potential vaccines.
Methods: For this study PubMed, MEDLINE, and Embase electronic databases were used to search for eligible studies on the interface between novel coronavirus and vaccine design until December 31, 2020.
Results: We have included fourteen non-randomized and randomized controlled phase I-III trials. Implementation of a universal vaccination program with proven safety and efficacy through robust clinical evaluation is the long-term goal for preventing COVID-19. The immunization program must be cost-effective for mass production and accessibility. Despite pioneering techniques for the fast-track development of the vaccine in the current global emergency, mass production and availability of an effective COVID-19 vaccine could take some more time.
Conclusion: Our findings suggest a revisiting of the reported solicited and unsolicited systemic adverse events for COVID-19 candidate vaccines. Hence, it is alarming to judiciously expose thousands of participants to COVID-19 candidate vaccines at Phase-3 trials that have adverse events and insufficient evidence on safety and effectiveness that necessitates further justification.