Publications

We maintain this section to inform interested users about independent scientific studies conducted on MetaSystems products. We assume no responsibility or liability regarding the accuracy or correct use of the information or statements provided by external authors. The conclusions or statements expressed in the publications listed are those of the external authors or researchers. The publications may involve user-specific adaptations of MetaSystems products. They are not intended for diagnostic use. For publications covered by the Intended Purpose of Metafer or Ikaros, please refer to the respective instructions for use (IFU).

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Particle and Fibre Toxicology, 21
2024

Determining the toxicological effects of indoor air pollution on both a healthy and an inflammatory-comprised model of the alveolar epithelial barrier in vitro

Kirsty Meldrum, Stephen J. Evans, Michael J. Burgum, Shareen H. Doak, Martin J. D. Clift

<p>Exposure to indoor air pollutants (IAP) has increased recently, with people spending more time indoors (i.e. homes, offices, schools and transportation). Increased exposures of IAP on a healthy population are poorly understood, and those with allergic respiratory conditions even less so. The objective of this study, therefore, was to implement a well-characterised in vitro model of the human alveolar epithelial barrier (A549 + PMA differentiated THP-1 incubated with and without IL-13, IL-5 and IL-4) to determine the effects of a standardised indoor particulate (NIST 2583) on both a healthy lung model and one modelling a type-II (stimulated with IL-13, IL-5 and IL-4) inflammatory response (such as asthma).Using concentrations from the literature, and an environmentally appropriate exposure we investigated 232, 464 and 608ng/cm<sup>2</sup> of NIST 2583 respectively. Membrane integrity (blue dextran), viability (trypan blue), genotoxicity (micronucleus (Mn) assay) and (pro-)/(anti-)inflammatory effects (IL-6, IL-8, IL-33, IL-10) were then assessed 24 h post exposure to both models. Models were exposed using a physiologically relevant aerosolisation method (VitroCell Cloud 12 exposure system).No changes in Mn frequency or membrane integrity in either model were noted when exposed to any of the tested concentrations of NIST 2583. A significant decrease (p &lt; 0.05) in cell viability at the highest concentration was observed in the healthy model. Whilst cell viability in the "inflamed" model was decreased at the lower concentrations (significantly (p &lt; 0.05) after 464ng/cm<sup>2</sup>). A significant reduction (p &lt; 0.05) in IL-10 and a significant increase in IL-33 was seen after 24 h exposure to NIST 2583 (464, 608ng/cm<sup>2</sup>) in the "inflamed" model.Collectively, the results indicate the potential for IAP to cause the onset of a type II response as well as exacerbating pre-existing allergic conditions. Furthermore, the data imposes the importance of considering unhealthy individuals when investigating the potential health effects of IAP. It also highlights that even in a healthy population these particles have the potential to induce this type II response and initiate an immune response following exposure to IAP.</p>

Digital object identifier (DOI): 10.1186/s12989-024-00584-8

iScience, 27, 111108
2024

Preclinical validation of human recombinant glutamate-oxaloacetate transaminase for the treatment of acute ischemic stroke

María Pérez-Mato, Antonio Dopico-López, Yunus Akkoc, Sonia López-Amoedo, Clara Correa-Paz et al.

<p>The blood enzyme glutamate-oxaloacetate transaminase (GOT) has been postulated as an effective therapeutic to protect the brain during stroke. To demonstrate its potential clinical utility, a new human recombinant form of GOT (rGOT) was produced for medical use. We tested the pharmacokinetics and evaluated the protective efficacy of rGOT in rodent and non-human primate models that reflected clinical stroke conditions. We found that continuous intravenous administration of rGOT within the first 8 h after ischemic onset significantly reduced the infarct size in both severe (30%) and mild lesions (48%). Cerebrospinal fluid and proteomics analysis, in combination with positron emission tomography imaging, indicated that rGOT can reach the brain and induce cytoprotective autophagy and induce local protection by alleviating neuronal apoptosis. Our results suggest that rGOT can be safely used immediately in patients suspected of having a stroke. This study requires further validation in clinical stroke populations.</p>

Digital object identifier (DOI): 10.1016/j.isci.2024.111108

International journal of molecular sciences, 24
March, 2023

High Resolution and Automatable Cytogenetic Biodosimetry Using In Situ Telomere and Centromere Hybridization for the Accurate Detection of DNA Damage: An Overview.

M'Kacher, Radhia, Colicchio, Bruno, Junker, Steffen, El Maalouf, Elie, Heidingsfelder, Leonhard, Plesch, Andreas, Dieterlen, Alain, Jeandidier, Eric, Carde, Patrice, Voisin, Philippe

<p>In the event of a radiological or nuclear accident, or when physical dosimetry is not available, the scoring of radiation-induced chromosomal aberrations in lymphocytes constitutes an essential tool for the estimation of the absorbed dose of the exposed individual and for effective triage. Cytogenetic biodosimetry employs different cytogenetic assays including the scoring of dicentrics, micronuclei, and translocations as well as analyses of induced premature chromosome condensation to define the frequency of chromosome aberrations. However, inherent challenges using these techniques include the considerable time span from sampling to result, the sensitivity and specificity of the various techniques, and the requirement of highly skilled personnel. Thus, techniques that obviate these challenges are needed. The introduction of telomere and centromere (TC) staining have successfully met these challenges and, in addition, greatly improved the efficiency of cytogenetic biodosimetry through the development of automated approaches, thus reducing the need for specialized personnel. Here, we review the role of the various cytogenetic dosimeters and their recent improvements in the management of populations exposed to genotoxic agents such as ionizing radiation. Finally, we discuss the emerging potentials to exploit these techniques in a wider spectrum of medical and biological applications, e.g., in cancer biology to identify prognostic biomarkers for the optimal triage and treatment of patients.</p>

Digital object identifier (DOI): 10.3390/ijms24065699

Journal of clinical microbiology, 60, e0113122
2022

Evaluation of MetaSystems Automated Fluorescent Microscopy System for the Machine-Assisted Detection of Acid-Fast Bacilli in Clinical Samples.

Gianna Tomasello, Farnaz Foroughi, Danielle Padron, Angel Moreno, Niaz Banaei

<p>Manual reading of fluorescent acid-fast bacilli (AFB) microscopy slides is time-intensive and technically demanding. The aim of this study was to evaluate the accuracy<br /> of MetaSystems’ automated fluorescent AFB slide scanner and analyzer. Auramine O-stained slides corresponding to 133 culture-positive and 363 culture-negative respiratory (n = 284), tissue (n = 120), body fluid (n = 81), and other (n = 11) sources were evaluated with the MetaSystems Mycobacteria Scanner running the NEON Metafer AFB Module. The sensitivity and specificity of the MetaSystems platform was measured as a standalone diagnostic and as an assistant to technologists to review positive images. Culture results were used as the reference method. The MetaSystems platform failed to scan 57 (11.5%) slides. The MetaSystems platform used as a standalone had a sensitivity of 97.0% (129/133; 95% CI 92.5 to 99.2) and specificity of 12.7% (46/363; 95% CI 9.4 to 16.5). When positive scans were used to assist technologists, the MetaSystems platform had a sensitivity of 70.7% (94/133; 95% CI 62.2 to 78.3) and specificity of 89.0% (323/363; 95% CI 85.3 to 92.0). The manual microscopy method had a sensitivity of 79.7% (106/133; 95% CI 71.9 to 86.2) and specificity of 98.6% (358/363; 95% CI 96.8 to 99.6). The sensitivity of the MetaSystems platform was not impacted by smear grade or mycobacterial species. The majority (70.3%) of false positive smears had $21 smear results with the MetaSystems platform. Further performance improvements are needed before the MetaSystems’ automated fluorescent AFB slide reader can be used to assist microscopist in the clinical laboratory.</p>

Digital object identifier (DOI): 10.1128/jcm.01131-22

Radiation research
September, 2021

CytoRADx: A High-Throughput, Standardized Biodosimetry Diagnostic System Based on the Cytokinesis-Block Micronucleus Assay.

Capaccio, Chris, Perrier, Jay R., Cunha, Lídia, Mahnke, Ryan C., Lörch, Thomas, Porter, Michael, Smith, Chris L., Damer, Ken, Bourland, J. Daniel, Frizzell, Bart, Torelli, Jennifer, Vasquez, Marie, Brower, Jeremy B., Doyle-Eisele, Melanie, Taveras, Maria, Turner, Helen, Brenner, David J., Kowalski, Richard

<p>In a large-scale catastrophe, such as a nuclear detonation in a major city, it will be crucial to accurately diagnose large numbers of people to direct scarce medical resources to those in greatest need. Currently no FDA-cleared tests are available to diagnose radiation exposures, which can lead to complex, life-threatening injuries. To address this gap, we have achieved substantial advancements in radiation biodosimetry through refinement and adaptation of the cytokinesis-block micronucleus (CBMN) assay as a high throughput, quantitative diagnostic test. The classical CBMN approach, which quantifies micronuclei (MN) resulting from DNA damage, suffers from considerable time and expert labor requirements, in addition to a lack of universal methodology across laboratories. We have developed the CytoRADx™ System to address these drawbacks by implementing a standardized reagent kit, optimized assay protocol, fully automated microscopy and image analysis, and integrated dose prediction. These enhancements allow the CytoRADx System to obtain high-throughput, standardized results without specialized labor or laboratory-specific calibration curves. The CytoRADx System has been optimized for use with both humans and non-human primates (NHP) to quantify radiation dose-dependent formation of micronuclei in lymphocytes, observed using whole blood samples. Cell nuclei and resulting MN are fluorescently stained and preserved on durable microscope slides using materials provided in the kit. Up to 1,000 slides per day are subsequently scanned using the commercially based RADxScan™ Imager with customized software, which automatically quantifies the cellular features and calculates the radiation dose. Using less than 1 mL of blood, irradiated ex vivo, our system has demonstrated accurate and precise measurement of exposures from 0 to 8 Gy (90% of results within 1 Gy of delivered dose). These results were obtained from 636 human samples (24 distinct donors) and 445 NHP samples (30 distinct subjects). The system demonstrated comparable results during in vivo studies, including an investigation of 43 NHPs receiving single-dose total-body irradiation. System performance is repeatable across laboratories, operators, and instruments. Results are also statistically similar across diverse populations, considering various demographics, common medications, medical conditions, and acute injuries associated with radiological disasters. Dose calculations are stable over time as well, providing reproducible results for at least 28 days postirradiation, and for blood specimens collected and stored at room temperature for at least 72 h. The CytoRADx System provides significant advancements in the field of biodosimetry that will enable accurate diagnoses across diverse populations in large-scale emergency scenarios. In addition, our technological enhancements to the well-established CBMN assay provide a pathway for future diagnostic applications, such as toxicology and oncology.</p>

Digital object identifier (DOI): 10.1667/RADE-20-00030.1

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

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

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

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

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