- The phage T4 DNA ligase in vivo improves the survival-coupled bacterial mutagenesis. [Journal Article]
- MCMicrob Cell Fact 2019 Jun 13; 18(1):107
- CONCLUSIONS: Expression of T4 DNA ligase in vivo could notably enhance microbial survival to excess chromosomal damages caused by various mutagens. Potential application of T4 DNA ligase in microbial mutagenesis was explored by mutating and screening PHB producing E. coli XLPHB strain. When applied to atmospheric and room temperature plasma (ARTP) microbial mutagenesis, large survival pool was obtained. Mutants available for subsequent screening for desirable features. The use of T4 DNA ligase we were able to quickly improve the PHB production by generating a larger viable mutants pool. This method is a universal strategy can be employed in wide range of bacteria. It indicated that traditional random mutagenesis became more powerful in combine with modern genetic molecular biology and has exciting prospect.
- Impact of photochemical ageing on Polycyclic Aromatic Hydrocarbons (PAH) and oxygenated PAH (Oxy-PAH/OH-PAH) in logwood stove emissions. [Journal Article]
- STSci Total Environ 2019 May 31; 686:382-392
- The combustion of spruce logwood in a modern residential stove was found to emit polycyclic aromatic hydrocarbons (PAH) and oxygenated polycyclic aromatic hydrocarbons (OPAH) with emission factors of…
The combustion of spruce logwood in a modern residential stove was found to emit polycyclic aromatic hydrocarbons (PAH) and oxygenated polycyclic aromatic hydrocarbons (OPAH) with emission factors of 404 μg MJ-1 of 35 analysed PAH, 317 μg MJ-1 of 11 analysed Oxy-PAH and 12.5 μg MJ-1 of 5 analysed OH-PAH, most of which are known as potential mutagens and carcinogens. Photochemical ageing in an oxidation flow reactor (OFR) degraded particle-bound PAH, which was also reflected in declining PAH toxicity equivalent (PAH-TEQ) values by 45 to 80% per equivalent day of photochemical ageing in the atmosphere. OPAH concentrations decreased less than PAH concentrations during photochemical ageing, supposedly due to their secondary formation, while 1-hydroxynaphthalene, 1,5-dihydroxynaphthalene and 1,8-naphthalaldehydic acid were significantly increased after ageing. Furthermore, secondary organic aerosol (SOA) formation and aromatic compounds not included in targeted analysis were investigated by thermal-optical carbon analysis (TOCA) hyphenate to resonance-enhanced multi-photon ionisation time-of-flight mass spectrometry (REMPI-TOFMS). The commonly used PAH-source indicators phenanthrene/anthracene, fluoranthene/pyrene, retene/chrysene, and indeno[cd]pyrene/benzo[ghi]perylene remained stable during photochemical ageing, enabling identification of wood combustion emissions in ambient air. On the other hand, benz[a]pyrene/benz[e]pyrene and benz[a]anthracene/chrysene were found to decrease with increasing photochemical age. Retene/chrysene was not a proper classifier for the wood combustion emissions of this study, possibly due to more efficient combustion than in open wood burning, from which this diagnostic ratio was initially derived. This study motivates in-depth investigation of degradation kinetics of particle-bound species on different combustion aerosol as well as the consequences of photochemical ageing on toxicity and identification of wood combustion emissions in ambient air.
- Regeneration and evaluation of somaclones of sugarcane variety Co86032 for yellow leaf disease resistance and yield traits. [Journal Article]
- JBJ Biosci 2019; 44(2)
- The present investigation was focussed on regeneration, evaluation and screening of somaclones for yellow leaf disease (YLD) resistance using in vitro mutagenesis from a popular susceptible sugarcane…
The present investigation was focussed on regeneration, evaluation and screening of somaclones for yellow leaf disease (YLD) resistance using in vitro mutagenesis from a popular susceptible sugarcane variety Co86032 using four chemical mutagens at three levels of concentration (sodium azide (SA) at 0.5 mg L-1, 1.0 mg L-1, 1.5 mg L-1; sodium nitrite (SN) at 3 mg L-1, 5 mg L-1, 7 mg L-1; ethyl methane sulphonate (EMS) at 0.6 μ ML-1, 0.8 μML-1, 1.0 μ ML-1 and 2,4 D at 4 mg L-1, 5 mg L-1, 6 mg L-1). A total of 1138 tissue culture seedlings obtained were evaluated for virus resistance both in natural field conditions and in controlled greenhouse condition after aphid vector transmission and presence or absence of virus was observed by visual screening and reverse transcription-polymerase chain reaction method. Four out of 207 asymptomatic plants (16T22, 16T23, 16T29 and 16T31) were devoid of virus coat protein band and were considered to be YLD resistant. The obtained resistance somaclones showed inferior yield traits so they have to be exploited as parents in hybridization programmes with commercial varieties to impart YLD resistance ultimately yielding agronomically superior YLD-resistant varieties in sugarcane.
- The Role of Environmental Exposures and the Epigenome in Health and Disease. [Review]
- EMEnviron Mol Mutagen 2019 Jun 08
- The genetic material of every organism exists within the context of regulatory networks that govern gene expression, collectively called the epigenome. Epigenetics has taken center stage in the study…
The genetic material of every organism exists within the context of regulatory networks that govern gene expression, collectively called the epigenome. Epigenetics has taken center stage in the study of diseases such as cancer and diabetes, but its integration into the field of environmental health is still emerging. As the Environmental Mutagenesis and Genomics Society (EMGS) celebrates its 50th Anniversary this year, we have come together to review and summarize the seminal advances in the field of environmental epigenomics. Specifically, we focus on the role epigenetics may play in multi and trans-generational transmission of environmentally induced health effects. We also summarize state of the art techniques for evaluating the epigenome, environmental epigenetic analysis, and the emerging field of epigenome editing. Finally, we evaluate transposon epigenetics as they relate to environmental exposures and explore the role of non-coding RNA as biomarkers of environmental exposures. While the field has advanced over the past several decades, including being recognized by EMGS with its own Special Interest Group, recently renamed Epigenomics, we are excited about the opportunities for environmental epigenetic science in the next 50 years. This article is protected by copyright. All rights reserved.
- Should dsRNA treatments applied in outdoor environments be regulated? [Review]
- EIEnviron Int 2019 Jun 04; :104856
- The New Zealand Environmental Protection Authority (EPA) issued a Decision that makes the use of externally applied double-stranded (ds)RNA molecules on eukaryotic cells or organisms technically out …
The New Zealand Environmental Protection Authority (EPA) issued a Decision that makes the use of externally applied double-stranded (ds)RNA molecules on eukaryotic cells or organisms technically out of scope of legislation on new organisms, making risk assessments of such treatments in the open environment unnecessary. The Decision was based on its view that the treatment does not create new or genetically modified organisms and rests on the EPA's conclusions that dsRNA is not heritable and is not a mutagen. For these reasons EPA decided that treatments using dsRNA do not modify genes or other genetic material. I found from an independent review of the literature on the topic indicated, however, that each of the major scientific justifications relied upon by the EPA was based on either an inaccurate interpretation of evidence or failure to consult the research literature pertaining to additional types of eukaryotes. The Decision also did not take into account the unknown and unique eukaryotic biodiversity of New Zealand. The safe use of RNA-based technology holds promise for addressing complex and persistent challenges in public health, agriculture and conservation. However, by failing to restrict the source or means of modifying the dsRNA, the EPA removed regulatory oversight that could prevent unintended consequences of this new technology such as suppression of genes other than those selected for suppression or the release of viral genes or genomes by failing to restrict the source or means of modifying the dsRNA.
- [Cancer Surveillance in Inflammatory Bowel Diseases]. [Journal Article]
- DMDtsch Med Wochenschr 2019; 144(11):753-756
- Patients with ulcerative colitis and Crohn's colitis, especially in the presence of primary sclerosing cholangitis, have an increased risk of developing colorectal cancer due to the longstanding colo…
Patients with ulcerative colitis and Crohn's colitis, especially in the presence of primary sclerosing cholangitis, have an increased risk of developing colorectal cancer due to the longstanding colonic inflammation. Therefore, anti-inflammatory drugs reduce this elevated risk.On the other hand, immunosuppressive medication can have direct mutagen effects or can lead to compromised tumor surveillance, therefore increasing the risk of extra-intestinal tumors. This article reviews recommendations concerning cancer surveillance strategies in patients with inflammatory bowel diseases.
- [Efficacy and safety of tocilizumab in patients with Takayasu arteritis]. [Journal Article]
- ZNZhonghua Nei Ke Za Zhi 2019 Jun 01; 58(6):444-448
- CONCLUSIONS: Compared with CTX treatment, TCZ treatment for TA with less prednisone has better efficacy and safety.
- Effects of light on aging and longevity. [Journal Article]
- ARAgeing Res Rev 2019 May 30; 53:100913
- Increasing evidence suggests an important role for light in regulation of aging and longevity. UV radiation is a mutagen that can promote aging and decrease longevity. In contrast, NIR light has show…
Increasing evidence suggests an important role for light in regulation of aging and longevity. UV radiation is a mutagen that can promote aging and decrease longevity. In contrast, NIR light has shown protective effects in animal disease models. In invertebrates, visible light can shorten or extend lifespan, depending on the intensity and wavelength composition. Visible light also impacts human health, including retina function, sleep, cancer and psychiatric disorders. Possible mechanisms of visible light include: controlling circadian rhythms, inducing oxidative stress, and acting through the retina to affect neuronal circuits and systems. Changes in artificial lighting (e.g., LEDs) may have implications for human health. It will be important to further explore the mechanisms of how light affects aging and longevity, and how light affects human health.
- Generation of a fully erythromycin-sensitive strain of Clostridioides difficile using a novel CRISPR-Cas9 genome editing system. [Journal Article]
- SRSci Rep 2019 May 31; 9(1):8123
- Understanding the molecular pathogenesis of Clostridioides difficile has relied on the use of ermB-based mutagens in erythromycin-sensitive strains. However, the repeated subcultures required to isol…
Understanding the molecular pathogenesis of Clostridioides difficile has relied on the use of ermB-based mutagens in erythromycin-sensitive strains. However, the repeated subcultures required to isolate sensitive variants can lead to the acquisition of ancillary mutations that affect phenotype, including virulence. CRISPR-Cas9 allows the direct selection of mutants, reducing the number of subcultures and thereby minimising the likelihood of acquiring additional mutations. Accordingly, CRISPR-Cas9 was used to sequentially remove from the C. difficile 630 reference strain (NCTC 13307) two ermB genes and pyrE. The genomes of the strains generated (630Δerm* and 630Δerm*ΔpyrE, respectively) contained no ancillary mutations compared to the NCTC 13307 parental strain, making these strains the preferred option where erythromycin-sensitive 630 strains are required. Intriguingly, the cas9 gene of the plasmid used contained a proximal frameshift mutation. Despite this, the frequency of mutant isolation was high (96% and 89% for ermB and pyrE, respectively) indicating that a functional Cas9 is still being produced. Re-initiation of translation from an internal AUG start codon would produce a foreshortened protein lacking a RuvCI nucleolytic domain, effectively a 'nickase'. The mutation allowed cas9 to be cloned downstream of the strong Pthl promoter. It may find application elsewhere where the use of strong, constitutive promoters is preferred.
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- Efficacy and acceptability of immunosuppressive agents for pediatric frequently-relapsing and steroid-dependent nephrotic syndrome: A network meta-analysis of randomized controlled trials. [Meta-Analysis]
- MMedicine (Baltimore) 2019; 98(22):e15927
- CONCLUSIONS: No significant differences in acceptability were found. Our results suggest that cyclophosphamide may be preferred initially in children with FRSN/SDNS, chlorambucil, and rituximab may be acceptable medications for patients with FRSN/SDNS. Long-term follow-up trials focused on gonadal toxicity and limitation of maximum dosage of cyclophosphamide should been carried out.