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The British journal of dermatology
January, 2021

COVID-19 related dermatosis in November 2019. Could this case be Italy's patient zero?

Gianotti, R., Barberis, M., Fellegara, G., Galván-Casas, C., Gianotti, E.

<p>Milan, the largest city in northern Italy, was one of the first European metropolitan areas to be affected by the COVID-19 pandemic. We analyzed skin biopsies of patients from Milan with dermatoses and positive PCR swabs for SARS-CoV-2 at different stages of the infection (1,2). The results were compared to skin biopsies of 20 COVID-19 non-diagnosed patients with dermatoses, who were at high-risk of COVID-19 infection.</p>

Digital object identifier (DOI): 10.1111/bjd.19804

Pediatric reports, 13, 9--14
December, 2020

Detection of New Translocation in Infant Twins with Concordant ALL and Discordant Outcome.

Bahoush, Golamreza, Vafapour, Maryam, Kariminejad, Roxana

<p>About 2-5% of acute lymphoblastic leukemia (ALL) cases in pediatric patients are infants with an unfavorable prognosis because of high relapse probability. Early detection of the disease is, therefore, very important. Despite the fact that leukemia in twins occurs rarely, more attention has been paid to it in genetic studies. In the present study, through cytogenetic testing, a special case of concordant ALL in monozygotic twins was presented with different outcomes. In spite of an acceptable initial consequence to medical treatment in twins, in another brother (Twin B), early relapse was observed. In the cytogenetic study, both twins expressed while twin A expressed No cases have previously reported this mutation. Whether this translocation has a protective role for leukemia with mixed-lineage leukemia (MLL) gene rearrangement is still unclear. The difference in the translocation identified in the identical twins is also subject to further investigations.</p>

Digital object identifier (DOI): 10.3390/pediatric13010002

Journal of personalized medicine, 10
October, 2020

Radiation Biomarkers in Large Scale Human Health Effects Studies.

Moquet, Jayne, Rothkamm, Kai, Barnard, Stephen, Ainsbury, Elizabeth

Following recent developments, the RENEB network (Running the European Network of biological dosimetry and physical retrospective dosimetry) is in an excellent position to carry out large scale molecular epidemiological studies of ionizing radiation effects, with validated expertise in the dicentric, fluorescent hybridization (FISH)-translocation, micronucleus, premature chromosome condensation, gamma-H2AX foci and gene expression assays. Large scale human health effects studies present complex challenges such as the practical aspects of sample logistics, assay costs, effort, effect modifiers and quality control/assurance measures. At Public Health England, the dicentric, automated micronucleus and gamma-H2AX radiation-induced foci assays have been tested for use in a large health effects study. The results of the study and the experience gained in carrying out such a large scale investigation provide valuable information that could help minimise random and systematic errors in biomarker data sets for health surveillance analyses going forward.

Digital object identifier (DOI): 10.3390/jpm10040155

International journal of radiation biology, 96, 1263--1273
October, 2020

Comparison of inexperienced operators and experts in γH2A.X and 53BP1 foci assay for high-throughput biodosimetry approaches in a mass casualty incident.

Bucher, Martin, Duchrow, Lukas, Endesfelder, David, Roessler, Ute, Gomolka, Maria

<p>In case of population exposure by ionizing radiation, a fast and reliable dose assessment of exposed and non-exposed individuals is crucial important. In initial triage, physicians have to take fast decisions whom to treat with adequate medical care. In addition, worries about significant exposure can be taken away from hundreds to thousands non- or low exposed individuals. Studies have shown that the γH2A.X radiation-induced foci assay is a promising test for fast triage decisions. However, in a large-scale scenario most biodosimetry laboratories will quickly reach their capacity limit. The aim of this study was to evaluate the benefit of inexperienced experimenters to speed up the foci assay and manual foci scoring. The participants of two training courses performed the radiation-induced foci assay (γH2A.X) under the guidance of experts and scored foci (γH2A.X and 53BP1) on sham-irradiated and irradiated blood samples (0.05-1.5 Gy). The outcome of laboratory experiments and manual foci scoring by 26 operators with basic experience in laboratory work was statistically analyzed in comparison to the results from experts. Inexperienced operators prepared slides with significant dose-effects (0, 0.1 and 1.0 Gy) for semi-automatic microscopic analyses. Manual foci scoring by inexperienced scorer resulted in a dose-effect curve for γH2A.X, 53BP1 and co-localized foci. In addition, inexperienced scorers were able to distinguish low irradiation doses from unirradiated cells. While 53BP1 foci scoring was in accordance to the expert counting, differences between beginners and expert increased for γH2A.X or co-localized foci. In case of a large-scale radiation event, inexperienced staff is useful to support laboratories in slide preparation for semi-automatic foci counting as well as γH2A.X and 53BP1 manual foci scoring for triage-mode biodosimetry. Slides can be clearly classified in the non-, low- or high-exposed category.</p>

Digital object identifier (DOI): 10.1080/09553002.2020.1793024

Tuberculosis (Edinburgh, Scotland), 125, 101993
September, 2020

Machine-assisted interpretation of auramine stains substantially increases through-put and sensitivity of microscopic tuberculosis diagnosis.

Horvath, L., Hänselmann, S., Mannsperger, H., Degenhardt, S., Last, K., Zimmermann, S., Burckhardt, I.

Of all bacterial infectious diseases, infection by Mycobacterium tuberculosis poses one of the highest morbidity and mortality burdens on humans throughout the world. Due to its speed and cost-efficiency, manual microscopy of auramine-stained sputum smears remains a crucial first-line detection method. However, it puts considerable workload on laboratory staff and suffers from a limited sensitivity. Here we validate a scanning and analysis system that combines fully-automated microscopy with deep-learning based image analysis. After automated scanning, the system summarizes diagnosis-relevant image information and presents it to the microbiologist in order to assist diagnosis. We tested the benefit of the automated scanning and analysis system using 531 slides from routine workflow, of which 56 were from culture positive specimen. Assistance by the scanning and analysis system allowed for a higher sensitivity (40/56 positive slides detected) than manual microscopy (34/56 positive slides detected), while greatly reducing manual slide-analysis time from a recommended 5-15 min to around 10 s per slide on average.

Digital object identifier (DOI): 10.1016/j.tube.2020.101993

Toxicology in vitro : an international journal published in association with BIBRA, 66, 104866
August, 2020

A comparative in vitro toxicity assessment of electronic vaping product e-liquids and aerosols with tobacco cigarette smoke.

Wieczorek, R., Phillips, G., Czekala, L., Trelles Sticken, E., O'Connell, G., Simms, L., Rudd, K., Stevenson, M., Walele, T.

The use of electronic vaping products (EVPs) continues to increase worldwide among adult smokers in parallel with accumulating information on their potential toxicity and relative safety compared to tobacco smoke. At this time, in vitro assessments of many widely available EVPs are limited. In this study, an in vitro battery of established assays was used to examine the cytotoxic (Neutral red uptake), genotoxic (In vitro micronucleus) and mutagenic (Bacterial reverse mutation) responses of two commercial EVPs (blu GO™ disposable and blu PLUS+™ rechargeable) when compared to smoke from a reference cigarette (3R4F). In total, 12 commercial products were tested as e-liquids and as aerosols. In addition, two experimental base liquids containing 1.2% and 2.4% nicotine were also assessed to determine the effect of flavour and nicotine on all three assays. In the bacterial reverse mutation (Ames) and in vitro micronucleus (IVM) assays, exposures to e-liquids and EVP aerosols, with and without nicotine and in a range of flavourings, showed no mutagenic or genotoxic effects compared to tobacco smoke. The neutral red uptake (NRU) assay showed significantly reduced cytotoxicity (P < .05) for whole undiluted EVP aerosols compared to tobacco smoke, which by contrast was markedly cytotoxic even when diluted. The reduced in vitro toxicological responses of the EVPs add to the increasing body of scientific weight-of-evidence supporting the role of high-quality EVPs as a harm reduction tool for adult smokers.

Digital object identifier (DOI): 10.1016/j.tiv.2020.104866

Applied and environmental microbiology, 86
August, 2020

3-Hydroxybutyrate Derived from Poly-3-Hydroxybutyrate Mobilization Alleviates Protein Aggregation in Heat-Stressed Herbaspirillum seropedicae SmR1.

Alves, Luis Paulo Silveira, Santana-Filho, Arquimedes Paixão, Sassaki, Guilherme Lanzi, de Oliveira Pedrosa, Fabio, Maltempi de Souza, Emanuel, Chubatsu, Leda Satie, Müller-Santos, Marcelo

Under conditions of carbon starvation or thermal, osmotic, or oxidative shock, mutants affected in the synthesis or mobilization of poly-3-hydroxybutyrate (PHB) are known to survive less well. It is still unclear if the synthesis and accumulation of PHB are sufficient to protect bacteria against stress conditions or if the stored PHB has to be mobilized. Here, we demonstrated that mobilization of PHB in SmR1 was heat-shock activated at 45°C. proton ( H) nuclear magnetic resonance spectroscopy (i.e., H-nuclear magnetic resonance) showed that heat shock increased amounts of 3-hydroxybutyrate (3HB) only in strains able to synthesize and mobilize PHB. SmR1 mutants unable to synthesize or mobilize PHB were more susceptible to heat shock and survived less well than the parental strain. When 100 mM 3-hydroxybutyrate was added to the medium, the Δ strain (an mutant unable to synthesize PHB) and the double mutant with deletion of both and (i.e., Δ ) (unable to mobilize PHB) showed partial rescue of heat adaptability (from 0% survival without 3HB to 40% of the initial viable population). Addition of 200 mM 3HB before the imposition of heat shock reduced protein aggregation to 15% in the Δ mutant and 12% in the Δ mutant. We conclude that SmR1 is naturally protected by 3HB released by PHB mobilization, while mutants unable to generate large amounts of 3HB under heat shock conditions are less able to cope with heat damage. Bacteria are subject to abrupt changes in environmental conditions affecting their growth, requiring rapid adaptation. Increasing the concentration of some metabolites can protect bacteria from hostile conditions that lead to protein denaturation and precipitation, as well as damage to plasma membranes. In this work, we demonstrated that under thermal shock, the bacterium depolymerized its intracellular stock polymer known as poly-3-hydroxybutyrate (PHB), rapidly increasing the concentration of 3-hydroxybutyrate (3HB) and decreasing protein precipitation by thermal denaturation. Mutant strains unable to produce or depolymerize PHB suffered irreparable damage during thermal shock, resulting in fast death when incubated at 45°C. Our results will contribute to the development of bacteria better adapted to high temperatures found either in natural conditions or in industrial processes. In the case of and other bacteria that interact beneficially with plants, the understanding of PHB metabolism can be decisive for the development of more-competitive strains and their application as biofertilizers in agriculture.

Digital object identifier (DOI): 10.1128/AEM.01265-20

Molecular ecology
July, 2020

Adaptive divergence across Southern Ocean gradients in the pelagic diatom Fragilariopsis kerguelensis.

Postel, Ute, Glemser, Barbara, Salazar Alekseyeva, Katherine, Eggers, Sarah Lena, Groth, Marco, Glöckner, Gernot, John, Uwe, Mock, Thomas, Klemm, Kerstin, Valentin, Klaus, Beszteri, Bánk

The Southern Ocean is characterized by longitudinal water circulations crossed by strong latitudinal gradients. How this oceanographic background shapes planktonic populations is largely unknown, despite the significance of this region for global biogeochemical cycles. Here, we show, based on genomic, morphometric, ecophysiological and mating compatibility data, an example of ecotypic differentiation and speciation within an endemic pelagic inhabitant, the diatom Fragilariopsis kerguelensis. We discovered three genotypic variants, one present throughout the latitudinal transect sampled, the others restricted to the north and south, respectively. The latter two showed reciprocal monophyly across all three genomes and significant ecophysiological differences consistent with local adaptation, but produced viable offspring in laboratory crosses. The third group was also reproductively isolated from the latter two. We hypothesize that this pattern originated by an adaptive expansion accompanied by ecotypic divergence, followed by sympatric speciation.

Digital object identifier (DOI): 10.1111/mec.15554

Health physics, 119, 52--58
July, 2020

Automated Dicentric Aberration Scoring for Triage Dose Assessment: 60Co Gamma Ray Dose-response at Different Dose Rates.

Subramanian, Uma, O'Brien, Brett, McNamara, Maureen, Romanyukha, Lyudmila, Bolduc, David L., Olsen, Cara, Blakely, William F.

<p>The objective of this study was to establish radiation dose-response calibration curves using automated dicentric scoring to support rapid and accurate cytogenetic triage dose-assessment. Blood was drawn from healthy human volunteers and exposed to Co gamma rays at several dose rates (i.e., 1.0, 0.6, and 0.1 Gy min). After radiation, the blood was placed for 2 h in a 37 °C incubator for repair. Blood was then cultured in complete media to which a mitogen (i.e., phytoghemagglutinin, concentration 4%) was added for 48 h. Colcemid was added to the culture at a final concentration of 0.2 μg mL after 24 h for the purpose of arresting first-division metaphase mitotics. Cells were harvested at the end of 48 h. Samples were processed using an automated metaphase harvester and automated microscope metaphase finder equipped with a suite of software including a specialized automated dicentric scoring application. The data obtained were used to create dose-response tables of dicentric yields. The null hypothesis that the data is Poisson-distributed could not be rejected at the significance level of α = 0.05 using results from a Shiny R Studio application (goodness-of-fit Poisson). Calibration curves based on linear-quadratic fits for Co gamma rays at the three different dose rates were generated using these data. The calibration curves were used to detect blind test cases. In conclusion, using the automated harvester and automated microscope metaphase finder with associated automated dicentric scoring software demonstrates high-throughput with suitable accuracy for triage radiation dose assessment.</p>

Digital object identifier (DOI): 10.1097/HP.0000000000001285

Genes, 11
July, 2020

Deciphering the Impact of a Bacterial Infection on Meiotic Recombination in Arabidopsis with Fluorescence Tagged Lines.

Gratias, Ariane, Geffroy, Valérie

<p>Plants are under strong evolutionary pressure to maintain surveillance against pathogens. One major disease resistance mechanism is based on NB-LRR (NLR) proteins that specifically recognize pathogen effectors. The cluster organization of the NLR gene family could favor sequence exchange between NLR genes via recombination, favoring their evolutionary dynamics. Increasing data, based on progeny analysis, suggest the existence of a link between the perception of biotic stress and the production of genetic diversity in the offspring. This could be driven by an increased rate of meiotic recombination in infected plants, but this has never been strictly demonstrated. In order to test if pathogen infection can increase DNA recombination in pollen meiotic cells, we infected Fluorescent Tagged Lines (FTL) with the virulent bacteria . We measured the meiotic recombination rate in two regions of chromosome 5, containing or not an NLR gene cluster. In all tested intervals, no significant difference in genetic recombination frequency between infected and control plants was observed. Although it has been reported that pathogen exposure can sometimes increase the frequency of recombinant progeny in plants, our findings suggest that meiotic recombination rate in may be resilient to at least some pathogen attack. Alternative mechanisms are discussed.</p>

Digital object identifier (DOI): 10.3390/genes11070832

Science advances, 6, eabb3446
June, 2020

Molecular atlas of the adult mouse brain.

Ortiz, Cantin, Navarro, Jose Fernandez, Jurek, Aleksandra, Märtin, Antje, Lundeberg, Joakim, Meletis, Konstantinos

Brain maps are essential for integrating information and interpreting the structure-function relationship of circuits and behavior. We aimed to generate a systematic classification of the adult mouse brain based purely on the unbiased identification of spatially defining features by employing whole-brain spatial transcriptomics. We found that the molecular information was sufficient to deduce the complex and detailed neuroanatomical organization of the brain. The unsupervised (non-expert, data-driven) classification revealed new area- and layer-specific subregions, for example in isocortex and hippocampus, and new subdivisions of striatum. The molecular atlas further supports the characterization of the spatial identity of neurons from their single-cell RNA profile, and provides a resource for annotating the brain using a minimal gene set-a brain palette. In summary, we have established a molecular atlas to formally define the spatial organization of brain regions, including the molecular code for mapping and targeting of discrete neuroanatomical domains.

Digital object identifier (DOI): 10.1126/sciadv.abb3446

Genes, 11
June, 2020

Interstitial Telomeric Repeats Are Rare in Turtles.

Clemente, Lorenzo, Mazzoleni, Sofia, Pensabene Bellavia, Eleonora, Augstenová, Barbora, Auer, Markus, Praschag, Peter, Protiva, Tomáš, Velenský, Petr, Wagner, Philipp, Fritz, Uwe, Kratochvíl, Lukáš, Rovatsos, Michail

<p>Telomeres are nucleoprotein complexes protecting chromosome ends in most eukaryotic organisms. In addition to chromosome ends, telomeric-like motifs can be accumulated in centromeric, pericentromeric and intermediate (i.e., between centromeres and telomeres) positions as so-called interstitial telomeric repeats (ITRs). We mapped the distribution of (TTAGGG) repeats in the karyotypes of 30 species from nine families of turtles using fluorescence in situ hybridization. All examined species showed the expected terminal topology of telomeric motifs at the edges of chromosomes. We detected ITRs in only five species from three families. Combining our and literature data, we inferred seven independent origins of ITRs among turtles. ITRs occurred in turtles in centromeric positions, often in several chromosomal pairs, in a given species. Their distribution does not correspond directly to interchromosomal rearrangements. Our findings support that centromeres and non-recombining parts of sex chromosomes are very dynamic genomic regions, even in turtles, a group generally thought to be slowly evolving. However, in contrast to squamate reptiles (lizards and snakes), where ITRs were found in more than half of the examined species, and birds, the presence of ITRs is generally rare in turtles, which agrees with the expected low rates of chromosomal rearrangements and rather slow karyotype evolution in this group.</p>

Digital object identifier (DOI): 10.3390/genes11060657

Scientific reports, 10, 6682
April, 2020

α-synuclein inclusions are abundant in non-neuronal cells in the anterior olfactory nucleus of the Parkinson's disease olfactory bulb.

Stevenson, Taylor J., Murray, Helen C., Turner, Clinton, Faull, Richard L. M., Dieriks, Birger V., Curtis, Maurice A.

Reduced olfactory function (hyposmia) is one of the most common non-motor symptoms experienced by those living with Parkinson's disease (PD), however, the underlying pathology of the dysfunction is unclear. Recent evidence indicates that α-synuclein (α-syn) pathology accumulates in the anterior olfactory nucleus of the olfactory bulb years before the motor symptoms are present. It is well established that neuronal cells in the olfactory bulb are affected by α-syn, but the involvement of other non-neuronal cell types is unknown. The occurrence of intracellular α-syn inclusions were quantified in four non-neuronal cell types - microglia, pericytes, astrocytes and oligodendrocytes as well as neurons in the anterior olfactory nucleus of post-mortem human PD olfactory bulbs (n = 11) and normal olfactory bulbs (n = 11). In the anterior olfactory nucleus, α-syn inclusions were confirmed to be intracellular in three of the four non-neuronal cell types, where 7.78% of microglia, 3.14% of pericytes and 1.97% of astrocytes were affected. Neurons containing α-syn inclusions comprised 8.60% of the total neuron population. Oligodendrocytes did not contain α-syn. The data provides evidence that non-neuronal cells in the PD olfactory bulb contain α-syn inclusions, suggesting that they may play an important role in the progression of PD.

Digital object identifier (DOI): 10.1038/s41598-020-63412-x

International journal of radiation biology, 96, 214--219
February, 2020

An alternative approach for the induction of premature chromosome condensation in human peripheral blood lymphocytes using mitotic Akodon cells.

Selvan Gnana Sekaran, Tamizh, Ricoul, Michelle, Brochard, Patricia, Herate, Cecile, Sabatier, Laure

The premature chromosome condensation (PCC) technique is used to study exposure to external radiation through the determination of chromosome fragments observed in interphase cells. The presence of large telomeric signals in CHO cells interferes with the detection of PCC fragments and the identification of dicentric chromosomes. We present an improved method for the fusion of G0-lymphocytes with mitotic cells (few chromosomes and weakly-staining telomeric sequences) to induce PCC in combination with rapid quantification of dicentric chromosomes and centric rings as an alternative to the classical CHO cell fusion technique. Whole blood from three healthy volunteers was γ-irradiated with 0, 2, or 4 Gy. Following a 24 h incubation post-exposure at 37 °C, chromosome spreads of isolated lymphocytes were prepared by standard PCC procedures using mitotic cells. The percentage of scorable fusions, measured by telomere/centromere (T/C) staining, for -induced PCC was higher than that for CHO-induced PCC, irrespective of radiation exposure. Importantly, both techniques gave the same result for biodosimetry evaluation. The mitotic cell-induced PCC fusion assay, in combination with the scoring of dicentric chromosomes and rings by T/C staining of G0-lymphocytes is a suitable alternative for fast and reliable dose estimation after accidental radiation exposure.

Digital object identifier (DOI): 10.1080/09553002.2019.1625493

Scientific reports, 10, 2899
February, 2020

A High Throughput Approach to Reconstruct Partial-Body and Neutron Radiation Exposures on an Individual Basis.

Shuryak, Igor, Turner, Helen C., Perrier, Jay R., Cunha, Lydia, Canadell, Monica Pujol, Durrani, Mohammad H., Harken, Andrew, Bertucci, Antonella, Taveras, Maria, Garty, Guy, Brenner, David J.

Biodosimetry-based individualized reconstruction of complex irradiation scenarios (partial-body shielding and/or neutron + photon mixtures) can improve treatment decisions after mass-casualty radiation-related incidents. We used a high-throughput micronucleus assay with automated scanning and imaging software on ex-vivo irradiated human lymphocytes to: a) reconstruct partial-body and/or neutron exposure, and b) estimate separately the photon and neutron doses in a mixed exposure. The mechanistic background is that, compared with total-body photon irradiations, neutrons produce more heavily-damaged lymphocytes with multiple micronuclei/binucleated cell, whereas partial-body exposures produce fewer such lymphocytes. To utilize these differences for biodosimetry, we developed metrics that describe micronuclei distributions in binucleated cells and serve as predictors in machine learning or parametric analyses of the following scenarios: (A) Homogeneous gamma-irradiation, mimicking total-body exposures, vs. mixtures of irradiated blood with unirradiated blood, mimicking partial-body exposures. (B) X rays vs. various neutron + photon mixtures. The results showed high accuracies of scenario and dose reconstructions. Specifically, receiver operating characteristic curve areas (AUC) for sample classification by exposure type reached 0.931 and 0.916 in scenarios A and B, respectively. R for actual vs. reconstructed doses in these scenarios reached 0.87 and 0.77, respectively. These encouraging findings demonstrate a proof-of-principle for the proposed approach of high-throughput reconstruction of clinically-relevant complex radiation exposure scenarios.

Digital object identifier (DOI): 10.1038/s41598-020-59695-9

International journal of molecular sciences, 21
February, 2020

Micronucleus Assay: The State of Art, and Future Directions.

Sommer, Sylwester, Buraczewska, Iwona, Kruszewski, Marcin

During almost 40 years of use, the micronucleus assay (MN) has become one of the most popular methods to assess genotoxicity of different chemical and physical factors, including ionizing radiation-induced DNA damage. In this minireview, we focus on the position of MN among the other genotoxicity tests, its usefulness in different applications and visibility by international organizations, such as International Atomic Energy Agency, Organization for Economic Co-operation and Development and International Organization for Standardization. In addition, the mechanism of micronuclei formation is discussed. Finally, foreseen directions of the MN development are pointed, such as automation, buccal cells MN and chromothripsis phenomenon.

Digital object identifier (DOI): 10.3390/ijms21041534

Mutation research, 849, 503141
January, 2020

Premature chromosome condensation assay to study influence of high-level natural radiation on the initial DNA double strand break repair in human G0 lymphocytes.

Vivek Kumar, P. R., Karuppasamy, C. V., Ramachandran, E. N., Anil Kumar, V., Jaikrishan, G., Das, Birajalaxmi

The inherent capacity of individuals to efficiently repair ionizing radiation induced DNA double strand breaks (DSBs) may be inherited, however, it is influenced by several epigenetic and environmental factors. A pilot study tested whether chronic low dose natural radiation exposure influences the rejoining of initial DNA DSBs induced by a 2 Gy γ-irradiation in 22 individuals from high (&gt;1.5 mGy/year) and normal (≤1.5 mGy/year) level natural radiation areas (H&amp;NLNRA) of Kerala. Rejoining of DSBs (during 1 h at 37 °C, immediately after irradiation) was evaluated at the chromosome level in the presence and absence of wortmannin (a potent inhibitor of DSB repair in normal human cells) using a cell fusion-induced premature chromosome condensation (PCC) assay. The PCC assay quantitates DSBs in the form of excess chromosome fragments in human G lymphocytes without the requirement for cell division. A quantitative difference was observed in the early rejoining of DNA DSBs between individuals from HLNRA and NLNRA, with HLNRA individuals showing a higher (P = 0.05) mean initial repair ratio. The results indicate an influence of chronic low dose natural radiation on initial DNA DSB repair in inhabitants of HLNRA of the Kerala coast.

Digital object identifier (DOI): 10.1016/j.mrgentox.2020.503141

Cancer letters, 469, 355--366
January, 2020

PD-L1+ aneuploid circulating tumor endothelial cells (CTECs) exhibit resistance to the checkpoint blockade immunotherapy in advanced NSCLC patients.

Zhang, Lina, Zhang, Xinyong, Liu, Yanxia, Zhang, Tongmei, Wang, Ziyu, Gu, Meng, Li, Yilin, Wang, Daisy Dandan, Li, Weiying, Lin, Peter Ping

Sustained angiogenesis and increased PD-L1 expression on endothelial and carcinoma cells contribute toward fostering an immunosuppressive microenvironment suitable for tumor growth. PD-L1 CTCs were reported to associate with poor prognosis in NSCLC patients. However, whether or not aneuploid circulating tumor endothelial cells (CTECs) express PD-L1, then serve as a surrogate biomarker to evaluate immunotherapy efficacy remains unknown. In this study, a novel SE-iFISH strategy was established to comprehensively quantify and characterize a full spectrum of aneuploid CTCs and CTECs in advanced NSCLC patients subjected to second-line anti-PD-1 (nivolumab) immunotherapy. In situ co-detection of diverse subtypes of aneuploid CTCs and CTECs expressing PD-L1 and Vimentin was performed. The present clinical study demonstrated that significant amounts of PD-L1 aneuploid CTCs and CTECs could be detected in histopathologic hPD-L1 patients. In contrast to decreased PD-L1 CTCs, the number of multiploid PD-L1 CTECs (≥tetrasomy 8) undergoing post-therapeutic karyotype shifting increased in patients along with tumor progression following anti-PD-1 treatment. Progressive disease (PD) lung cancer patients possessing multiploid PD-L1 CTECs had a significantly shorter PFS compared to those without PD-L1 CTECs. In carcinoma patients, aneuploid CTCs and CTECs may exhibit a functional interplay with respect to tumor angiogenesis, progression, metastasis, and response to immunotherapy.

Digital object identifier (DOI): 10.1016/j.canlet.2019.10.041

Mutation research, 849, 503086
January, 2020

Analysis of historical negative control group data from the rat in vivo micronucleus assay.

Lovell, D. P., Fellows, M., Saul, J., Whitwell, J., Custer, L., Dertinger, S., Escobar, P., Fiedler, R., Hemmann, U., Kenny, J., Smith, R., van der Leede, B. M., Zeller, A.

A database of micronuclei counts for historical negative control data from rat in vivo micronuclei tests performed in 10 different laboratories was established. Data were available from over 4000 negative control rats from 10 laboratories. The mean frequency of micronucleated cells (MN)/1000 cells ranged from 0.44 to 2.22, a 5-fold range. Overall there were no major sex or strain differences in frequency, although there were some small but statistically significant differences within laboratories. There was appreciable variability between experiments compared with variability within experiments in some laboratories. No specific factor was identified which could explain this variability although it was noted that many different vehicles were used in the experiments. It is hoped that these data will help laboratories beginning studies with the rat micronucleus assay and those involved in the assessment of micronucleus assay results.

Digital object identifier (DOI): 10.1016/j.mrgentox.2019.503086

BMC plant biology, 19, 183
May, 2019

Development and characterisation of interspecific hybrid lines with genome-wide introgressions from Triticum timopheevii in a hexaploid wheat background.

Devi, Urmila, Grewal, Surbhi, Yang, Cai-Yun, Hubbart-Edwards, Stella, Scholefield, Duncan, Ashling, Stephen, Burridge, Amanda, King, Ian P, King, Julie

Triticum timopheevii (2n = 4x = 28; A<sup>t</sup>A<sup>t</sup>GG), is an important source for new genetic variation for wheat improvement with genes for potential disease resistance and salt tolerance. By generating a range of interspecific hybrid lines, T. timopheevii can contribute to wheat's narrow gene-pool and be practically utilised in wheat breeding programmes. Previous studies that have generated such introgression lines between wheat and its wild relatives have been unable to use high-throughput methods to detect the presence of wild relative segments in such lines. A whole genome introgression approach, exploiting homoeologous recombination in the absence of the Ph1 locus, has resulted in the transfer of different chromosome segments from both the A and G genomes of T. timopheevii into wheat. These introgressions have been detected and characterised using single nucleotide polymorphism (SNP) markers present on a high-throughput Axiom® Genotyping Array. The analysis of these interspecific hybrid lines has resulted in the detection of 276 putative unique introgressions from T. timopheevii, thereby allowing the generation of a genetic map of T. timopheevii containing 1582 SNP markers, spread across 14 linkage groups representing each of the seven chromosomes of the A and G genomes of T. timopheevii. The genotyping of the hybrid lines was validated through fluorescence in situ hybridisation (FISH). Comparative analysis of the genetic map of T. timopheevii and the physical map of the hexaploid wheat genome showed that synteny between the two species is highly conserved at the macro-level and confirmed the presence of inter- and intra-genomic translocations within the A and G genomes of T. timopheevii that have been previously only detected through cytological techniques. In this work, we report a set of SNP markers present on a high-throughput genotyping array, able to detect the presence of T. timopheevii in a hexaploid wheat background making it a potentially valuable tool for marker assisted selection (MAS) in wheat pre-breeding programs. These valuable resources of high-density molecular markers and wheat-T. timopheevii hybrid lines will greatly enhance the work being undertaken for wheat improvement through wild relative introgressions.

Digital object identifier (DOI): 10.1186/s12870-019-1785-z