Abstract Papillary microcarcinoma (PMC) of the thyroid is defined as papillary thyroid carcinoma (PTC) measuring ≤1 cm. Many autopsy studies on subjects who died of non-thyroidal diseases reported ...latent small thyroid carcinoma in up to 5.2% of the subjects. A mass screening study for thyroid cancer in Japanese adult women detected small thyroid cancer in 3.5% of the examinees. This incidence was close to the incidence of latent thyroid cancer and more than 1000 times the prevalence of clinical thyroid cancer in Japanese women reported at that time. The question of whether it was correct to treat such PMCs surgically then arose. In 1993, according to Dr. Miyauchi's proposal, Kuma Hospital initiated an active surveillance trial for low-risk PMC as defined in the text. In 1995, Cancer Institute Hospital in Tokyo, Japan, started a similar observation trial. The accumulated data from the trials at these two institutions strongly suggest that active surveillance (i.e., observation without immediate surgery) can be the first-line management for low-risk PMC. Although our data showed that young age and pregnancy might be risk factors of disease progression, we think that these patients can also be candidates for active surveillance, because all of the patients who showed progression signs were treated successfully with a rescue surgery, and none of them died of PTC. In this review, we summarize the data regarding the active surveillance of low-risk PMC as support for physicians and institutions that are considering adopting this strategy.
Cellular adaptation to stressful environments such as starvation is essential to the survival of microbial communities, but the uniform response of the cell community may lead to entire cell death or ...severe damage to their fitness. Here, we demonstrate an elaborate response of the yeast community against glucose depletion, in which the first adapted cells kill the latecomer cells. During glucose depletion, yeast cells release autotoxins, such as leucic acid and L-2keto-3methylvalerate, which can even kill the clonal cells of the ones producing them. Although these autotoxins were likely to induce mass suicide, some cells differentiated to adapt to the autotoxins without genetic changes. If nondifferentiated latecomers tried to invade the habitat, autotoxins damaged or killed the latecomers, but the differentiated cells could selectively survive. Phylogenetically distant fission and budding yeast shared this behavior using the same autotoxins, suggesting that latecomer killing may be the universal system of intercellular communication, which may be relevant to the evolutional transition from unicellular to multicellular organisms.
Southern Amazonia is one of the less-explored regions by anuran taxonomists. We describe a small new species of snouted treefrog, genus Scinax, from this region, from a fluvial archipelago in the ...Juruena River, state of Mato Grosso, Brazil. The description is based on external morphology of adults and tadpoles, advertisement call and molecular data. The species is phylogenetically related to other snouted treefrogs of the Scinax cruentomma species group and shows the most southeastern distribution in Amazonia among its close relatives. It is distinguished from congeners mainly by its larger adult body size and bilobate vocal sac that reaches the level of the pectoral fold, a reddish-brown horizontal stripe on the iris, dark melanophores or blotches on the vocal sac and the throat of females, and the uniformly brown posterior portion of the thigh. The advertisement call comprises one pulsed note emitted at regular intervals, with a duration of 189-227 ms, 30-35 pulses/note and a dominant frequency of 2,250-2,344 Hz. The type locality is suffering several environmental impacts, including illegal mining, overfishing, unsustainable agriculture, uncontrolled logging and degradation associated with the construction of new hydroelectric dams. Further study of the biology and regional distribution of the new species is required to propose mitigation measures needed for its conservation.
Grain dust exposure is associated with respiratory symptoms among grain industry workers. However, the fungal assemblage that contribute to airborne grain dust has been poorly studied. We ...characterized the airborne fungal diversity at industrial grain- and animal feed mills, and identified differences in diversity, taxonomic compositions and community structural patterns between seasons and climatic zones. The fungal communities displayed strong variation between seasons and climatic zones, with 46% and 21% of OTUs shared between different seasons and climatic zones, respectively. The highest species richness was observed in the humid continental climate of the southeastern Norway, followed by the continental subarctic climate of the eastern inland with dryer, short summers and snowy winters, and the central coastal Norway with short growth season and lower temperature. The richness did not vary between seasons. The fungal diversity correlated with some specific mycotoxins in settled dust and with fibrinogen in the blood of exposed workers, but not with the personal exposure measurements of dust, glucans or spore counts. The study contributes to a better understanding of fungal exposures in the grain and animal feed industry. The differences in diversity suggest that the potential health effects of fungal inhalation may also be different.
Abstract
Single-cell Hi-C analysis of diploid human cells is difficult because of the lack of dense chromosome contact information and the presence of homologous chromosomes with very similar ...nucleotide sequences. Thus here, we propose a new algorithm to reconstruct the three-dimensional (3D) chromosomal architectures from the Hi-C dataset of single diploid human cells using allele-specific single-nucleotide variations (SNVs). We modified our recurrence plot-based algorithm, which is suitable for the estimation of the 3D chromosome structure from sparse Hi-C datasets, by newly incorporating a function of discriminating SNVs specific to each homologous chromosome. Here, we eventually regard a contact map as a recurrence plot. Importantly, the proposed method does not require any imputation for ambiguous segment information, but could efficiently reconstruct 3D chromosomal structures in single human diploid cells at a 1-Mb resolution. Datasets of segments without allele-specific SNVs, which were considered to be of little value, can also be used to validate the estimated chromosome structure. Introducing an additional mathematical measure called a refinement further improved the resolution to 40-kb or 100-kb. The reconstruction data supported the notion that human chromosomes form chromosomal territories and take fractal structures where the dimension for the underlying chromosome structure is a non-integer value.
SUMMARY
We previously developed a large‐scale genome restructuring technology called the TAQing system. It can induce genomic rearrangements by introducing transient and conditional formation of DNA ...double‐strand breaks (DSBs) via heat activation of a restriction enzyme TaqI, which can cleave DNA at 5′‐TCGA‐3′ sequences in the genome at higher temperatures (37–42°C). Such heat treatment sometimes confers lethal damage in certain plant species and TaqI cannot induce rearrangements in AT‐rich regions. To overcome such problems we developed an extended TAQing (Ex‐TAQing) system, which enables the use of a wider range of restriction enzymes active at standard plant‐growing temperatures. We established the Ex‐TAQing system using MseI that can efficiently cleave DNA at room temperature (at temperatures ranging from 22 to 25°C) and the 5′‐TTAA‐3′ sequence which is highly abundant in the Arabidopsis genome. A synthetic intron‐spanning MseI gene, which was placed downstream of a heat‐shock‐inducible promoter, was conditionally expressed upon milder heat treatment (33°C) to generate DSBs in Arabidopsis chromosomes. Genome resequencing revealed various types of genomic rearrangements, including copy number variations, translocation and direct end‐joining at MseI cleavage sites. The Ex‐TAQing system could induce large‐scale rearrangements in diploids more frequently (17.4%, n = 23) than the standard TAQing system. The application of this system to tetraploids generated several strains with chromosomal rearrangements associated with beneficial phenotypes, such as high salinity stress tolerance and hypersensitivity to abscisic acid. We have developed the Ex‐TAQing system, allowing more diverse patterns of genomic rearrangements, by employing various types of endonucleases and have opened a way to expand the capacity for artificial genome reorganization.
Significance Statement
We have developed an extended TAQing (Ex‐TAQing) system to overcome weaknesses concerning plant fertility and the efficiency of genomic rearrangement in the TAQing system. The Ex‐TAQing system can induce massive genomic rearrangements at normal growth temperatures and extend the variety of plant genome beyond genome ploidy. Ex‐TAQing is able to contribute to screening for useful traits in polyploid plants, providing insight into the relationship between the rearranged genome and phenotypic change.
Ferromanganese crusts record long‐term deep‐sea environmental changes. Thus, providing their reliable high‐resolution age models is important. We applied a magnetostratigraphic technique to estimate ...the growth rate of a ferromanganese crust using scanning SQUID (superconducting quantum interference device) microscope (SSM). SSM is designed to map the magnetic field across thin sections with submillimeter resolution. The crust sample was taken from the Takuyo‐Daigo Seamount, northwestern Pacific, and recorded a limited supply of dust and sediment from continents. After drift correction and removal of spike noises, the magnetic field values were stacked within the areas of high signal‐to‐noise ratios. By correlating the obtained profiles with a standard geomagnetic polarity timescale, we obtained an average growth rate of 3.37 ± 0.06 mm/Ma, which is consistent with that obtained by 10Be/9Be geochronology (2.93 ± 0.15 mm/Ma). S ratio mapping shows low values after ~3 Ma, associated with voids between columnar structures.
Key Points
SQUID microscopy delineated magnetic stripes in ferromanganese crust parallel to growth layers indicating a growth rate of 3.37 mm/Ma
Magnetic minerals may be oxidized magnetites of low and medium coercivities with high‐coercivity minerals such as hematite or goethite
S ratio shows heterogeneous distribution of high‐coercivity minerals younger than 3 Ma associated with voids between columnar structures
Dust from grain and feed production may cause adverse health effects in exposed workers. In this study we explored circulating miRNAs as potential biomarkers of occupational grain dust exposure. ...Twenty-two serum miRNAs were analyzed in 44 grain dust exposed workers and 22 controls. Exposed workers had significantly upregulated miR-18a-5p, miR-124-3p and miR-574-3p, and downregulated miR-19b-3p and miR-146a-5p, compared to controls. Putative target genes for the differentially expressed miRNAs were involved in a range of Kyoto Encyclopedia of Genes and Genomes signaling pathways, and 'Pathways in cancer' and 'Wnt signaling pathway' were common for all the five miRNAs. MiRNA-diseases association analysis showed a link between the five identified miRNAs and several lung diseases terms. A positive correlation between miR-124-3p, miR-18a-5p, and miR-574-3p and IL-6 protein level was shown, while miR-19b-3p was inversely correlated with CC-16 and sCD40L protein levels. Receiver-operating characteristic analysis of the five miRNA showed that three miRNAs (miR-574-3p, miR-124-3p and miR-18a-5p) could distinguish the grain dust exposed group from the control group, with miR-574-3p as the strongest predictor of grain dust exposure. In conclusion, this study identified five signature miRNAs as potential novel biomarkers of grain dust exposure that may have potential as early disease markers.
Distinct crustal remanent magnetic anomalies are a strong indicator of rocks with stable natural remanent magnetization (NRM) carriers. The latter are able to store information on the history of a ...rock over long geological periods, and can therefore be used for a variety of applications in the field of paleomagnetism and rock magnetism. Typically, paleomagnetic and rock‐magnetic studies rely on rocks bulk magnetic properties. With the advent of high‐resolution magnetometric scanning techniques, it is now possible to map magnetic sources at the mineral scale, identify the different magnetic carriers, and analyze the effect of geometry, microstructures, and composition on their magnetic response. We investigate the stability of discrete remanent magnetization sources of a microcline–sillimanite gneiss sample from Russell Belt with a strong NRM, by scanning the sample before, and after alternating field demagnetization to 100 mT. We quantified changes in the magnetization intensity and direction by inverting the magnetic scan data. Here, we confirm that the exsolved titanohematite with ilmenite lamellae is the major source of magnetization, and the coexisting multidomain hematite grains contribute little to the NRM, or the magnetic anomalies. The microstructures in the titanohematite control local magnetic properties at the mineral scale. Magnetic modeling results suggest a consistent average magnetization direction before and after demagnetization at both the grain and thin section scale, with a decrease in the magnetization intensity of ≈30%. Results are consistent with previous bulk magnetic measurements and the likelihood to use high‐resolution magnetometric techniques in future magnetic studies is high.
Plain Language Summary
The magnetism recorded in rocks is a useful tool to study our planet’s history and can be a blueprint for the design of modern information storage systems. The stability of the magnetic record is a main issue for many applications, and microstructure in minerals can play a major role. In early studies, the influence of microstructure on the magnetic properties of individual grains was an elusive topic; now, it is possible to investigate this link through high‐resolution imaging techniques, advanced micromagnetic simulations, and laboratory techniques. We used a modern magnetic technique that maps the magnetic response over a thin rock slice with submillimeter spatial resolution. We used these data to identify grains yielding different magnetic responses from a sample that has bulk magnetic properties, which indicate a stable magnetic record. To investigate the magnetic stability of individual grains, we acquired data before and after partial removal of the magnetization of the sample and estimated the changes in the magnetic properties at both the grain and sample scale by modeling the magnetic response. Results are consistent with the bulk magnetic properties and indicate that the sample efficiently held the magnetization and that grains’ microstructure has a strong effect on local magnetic properties.
Key Points
Magnetic measurements and microscopic observation indicate exsolved titanohematite is the main source of natural remanent magnetization
Data inversions confirm magnetic enhancement from microstructure in titanohematite and weak contribution of multidomain hematite to the NRM
Inversion results are consistent with bulk measurements and indicate little effect of alternating field demagnetization on the NRM
PDF
