Aminolevulinate synthase 2 mediates erythrocyte differentiation by regulating larval globin expression during Xenopus primary hematopoiesis

AbstractHemoglobin synthesis by erythrocytes continues throughout a vertebrate’s lifetime. The mechanism of mammalian heme synthesis has been studied for many years; aminolevulinate synthase 2 (ALAS2), a heme synthetase, is associated with X-linked dominant protoporphyria in humans. Amphibian and mammalian blood cells differ, but little is known about amphibian embryonic hemoglobin synthesis. We investigated the function of the Xenopus alas2 gene (Xalas2) in primitive amphibian erythrocytes and found that it is first expressed in primitive erythroid cells before hemoglobin alpha 3 subunit (hba3) during primary hematopoiesis and in the posterior ventral blood islands at the tailbud stage. Xalas2 is not expressed during secondary hematopoiesis in the dorsal lateral plate. Hemoglobin was barely detectable by o-dianisidine staining and hba3 transcript levels decreased in Xalas2-knockdown embryos. These results suggest that Xalas2 might be able to synthesize hemoglobin during hematopoiesis and mediate erythrocyte differentiation by regulating hba3 expression in Xenopus laevis

Evaluation and application of ice segregation parameters for frost heave prediction

The success of civil engineering construction in cold regions often depends on the assessment of the potential for frost heave. Over the past two decades two models have been presented to the engineering community to identify the frost heave potential, namely: (1) the segregation potential (SP), and (2) the discrete ice lens (DIL) models. These models are based on ice segregation parameters which can be obtained from simple laboratory freezing tests. However, the reliability of the ice segregation parameters obtained from the laboratory freezing tests is still in question. In recognition of the need to improve the reliability of the measurement of ice segregation parameters in a frost heave test, a study was conducted to: (1) investigate several improvements in the step freezing test used to measure ice segregation parameters, (2) examine several approximations used to interpret the laboratory step freezing test results, (3) demonstrate the compatibility of the SP and DIL parameters, (4) propose a method to obtain reliable ice segregation parameters, and (5) demonstrate the applicability of the DIL model to address field frost heave problems. The results of the study indicated: (1) the accuracy of measured ice segregation parameters may be improved if step freezing tests are conducted under shallower temperature gradients and the water intake velocity is accurately and continuously monitored, (2) inappropriate approximations may produce a significant error in the measurement of ice segregation parameters, (3) SP may be defined either by the ratios of the (i) heave velocity/1.09 to the overall temperature gradient of the frozen soil, or (ii) water intake velocity to the temperature gradient of the frozen fringe, (4) the SP and DIL ice segregation parameters are compatible, and (5) the reliability of both models is improved through the demonstration of the compatibility of the ice segregation parameters. The application of the frost heave prediction models was studied based on ice segregation parameters determined with the improved laboratory procedure. A practical method to predict the influence of the groundwater level using the DIL ice segregation parameters was proposed. A probabilistic approach for the DIL frost heave model was developed

Pulmonary intravascular large B-cell lymphoma successfully treated with rituximab, cyclophosphamide, vincristine, doxorubicin and prednisolone immunochemotherapy: Report of a patient surviving for over 1 year

A 73-year-old man with a history of lethargy, fever and dyspnea was admitted to Tottori University Hospital. A computed tomography (CT) scan revealed splenomegaly and diffusely spreading ground‑glass opacities (GGOs) in both lungs. A video‑assisted thoracoscopic surgery (VATS)‑guided lung biopsy revealed intravascular proliferation of large atypical lymphoid cells in the arteries, veins and alveolar walls. The patient was diagnosed with intravascular large B‑cell lymphoma (IVLBCL); he received 6 cycles of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (R‑CHOP) immunochemotherapy and has remained in complete remission for >1 year. Although IVLBCL is a rare disease, it should be considered in the differential diagnosis of pulmonary diffuse lesions that present with GGOs on CT scans

H, C, and N isotopic compositions of Hayabusa category 3 organic samples

Since isotopic ratios of H, C, and N are sensitive indicators for determining extraterrestrial organics, we have measured these isotopes of Hayabusa category 3 organic samples of RB-QD04-0047-02, RA-QD02-0120, and RB-QD04-0001 with ion imaging using a NanoSIMS ion microprobe. All samples have H, C, and N isotopic compositions that are terrestrial within errors (approximately ±50‰ for H, approximately ±9‰ for C, and approximately ±2‰ for N). None of these samples contain micrometer-sized hot spots with anomalous H, C, and N isotopic compositions, unlike previous isotope data for extraterrestrial organic materials, i.e., insoluble organic matters (IOMs) and nano-globules in chondrites, interplanetary dust particles (IDPs), and cometary dust particles. We, therefore, cannot conclude whether these Hayabusa category 3 samples are terrestrial contaminants or extraterrestrial materials because of the H, C, and N isotopic data. A coordinated study using microanalysis techniques including Fourier transform infrared spectrometry (FT-IR), time-of-flight secondary ion mass spectrometry (ToF-SIMS), NanoSIMS ion microprobe, Raman spectroscopy, X-ray absorption near edge spectroscopy (XANES), and transmission electron microscopy/scanning transmission electron microscopy (TEM/STEM) is required to characterize Hayabusa category 3 samples in more detail for exploring their origin and nature.This research was supported by the JSPS Strategic Fund for Strengthening Leading-edge Research and Development to the JAMSTEC

Secondary contact and genomic admixture between rhesus and long‐tailed macaques in the Indochina Peninsula

Understanding the process and consequences of hybridization is one of the major challenges in evolutionary biology. A growing body of literature has reported evidence of ancient hybridization events or natural hybrid zones in primates, including humans; however, we still have relatively limited knowledge about the pattern and history of admixture because there have been little studies that simultaneously achieved genome‐scale analysis and a geographically wide sampling of wild populations. Our study applied double‐digest restriction site‐associated DNA sequencing to samples from the six localities in and around the provisional hybrid zone of rhesus and long‐tailed macaques and evaluated population structure, phylogenetic relationships, demographic history, and geographic clines of morphology and allele frequencies. A latitudinal gradient of genetic components was observed, highlighting the transition from rhesus (north) to long‐tailed macaque distribution (south) as well as the presence of one northern population of long‐tailed macaques exhibiting unique genetic structure. Interspecific gene flow was estimated to have recently occurred after an isolation period, and the migration rate from rhesus to long‐tailed macaques was slightly greater than in the opposite direction. Although some rhesus macaque‐biased alleles have widely introgressed into long‐tailed macaque populations, the inflection points of allele frequencies have been observed as concentrated around the traditionally recognized interspecific boundary where morphology discontinuously changed; this pattern was more pronounced in the X chromosome than in autosomes. Thus, due to geographic separation before secondary contact, reproductive isolation could have evolved, contributing to the maintenance of an interspecific boundary and species‐specific morphological characteristics

ToF-SIMS analysis of carbonaceous particles in the sample catcher of the Hayabusa spacecraft

Three carbonaceous category 3 particles (RA-QD02-0180, RB-QD04-0037-01, and RB-QD04-0047-02) returned in the sample catcher from the Hayabusa spacecraft were analyzed by time of flight-secondary ion mass spectrometry (ToF-SIMS) to establish an analytical procedure for determination of their origins. By the different analytical schemes, the three particles gave distinct elemental and molecular ions, in which the organic carbons commonly appear to be associated with nitrogen, silicon, and/or fluorine. The particles could be debris of silicon rubber and fluorinated compounds and are therefore man-made artifacts rather than natural organic matter

Sequential analysis of carbonaceous materials in Hayabusa-returned samples for the determination of their origin

Preliminary results of the analyses of five carbonaceous materials (particle size of approximately 50 μm) from the Hayabusa spacecraft sample catcher, including their texture, chemistry, and chemical/isotopic compositions, are summarized. The carbonaceous particles underwent sequential analysis using a series of microanalytical instruments located at several research institutes and universities. Collected particles were initially classified into four categories: two categories containing extraterrestrial silicate particles, one category containing metal and quartz particles consistent with contamination from the sample catcher or sample manipulation tools, and a final category containing carbonaceous particles. Analysis of this final category was the main focus of this study. Through examination of the carbonaceous materials, the appropriate analytical processes for sample transportation and handling were optimized to minimize sample damage and terrestrial contamination. Particles were investigated by transmission electron microscopy/scanning transmission electron microscopy, and Ca-carbonate inclusions were found in one particle. In a different particle, a heterogeneous distribution of silicon in a uniform C, N, and O matrix was found. Though further analysis is required for a strict determination of particle origin, the differences in the microstructure and elemental distribution of the carbonaceous particles suggest multiple origins.TEM analyses were performed at JEOL Ltd. XANES analysis was conducted in UVSOR Facility in Institute for Molecular Science, supported by Nanotechnology Platform Program (Molecule and Material Synthesis) of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan

X-ray absorption near edge structure spectroscopic study of Hayabusa category 3 carbonaceous particles

Analyses with a scanning transmission x-ray microscope (STXM) using x-ray absorption near edge structure (XANES) spectroscopy were applied for the molecular characterization of two kinds of carbonaceous particles of unknown origin, termed category 3, which were collected from the Hayabusa spacecraft sample catcher. Carbon-XANES spectra of the category 3 particles displayed typical spectral patterns of heterogeneous organic macromolecules; peaks corresponding to aromatic/olefinic carbon, heterocyclic nitrogen and/or nitrile, and carboxyl carbon were all detected. Nitrogen-XANES spectra of the particles showed the presence of N-functional groups such as imine, nitrile, aromatic nitrogen, amide, pyrrole, and amine. An oxygen-XANES spectrum of one of the particles showed a ketone group. Differences in carbon- and nitrogen-XANES spectra of the category 3 particles before and after transmission electron microscopic (TEM) observations were observed, which demonstrates that the carbonaceous materials are electron beam sensitive. Calcium-XANES spectroscopy and elemental contrast mapping identified a calcium carbonate grain from one of the category 3 particles. No fluorine-containing molecular species were detected in fluorine-XANES spectra of the particles. The organic macromolecular features of the category 3 particles were distinct from commercial and/or biological ‘fresh (non-degraded)’ polymers, but the category 3 molecular features could possibly reflect degradation of contaminant polymer materials or polymer materials used on the Hayabusa spacecraft. However, an extraterrestrial origin for these materials cannot currently be ruled out