Noble gases in the K-T boundary clay from Stevns Klint, Denmark

Helium and neon isotopes were investigated in two beds of the Cretaceous-Tertiary (K-T) boundary collected at Stevns Klint in Denmark. Observed enrichments in ^3He and ^Ne relative to atmospheric abundances suggest that the K-T boundary sediment contains spallogenic He and Ne. Although this is a favorable result for the asteroid impact hypothesis, we need more data on noble gas isotopes not only in the K-T boundary sediments but also in sedimentary rocks other than the K-T boundary

Noble gases and mineralogy of primary igneous materials of the Yamato-793605 shergottite

Mineralogical and petrologic study on the Y-793605 lherzolitic shergottite using an optical microscope and an electron microprobe shows that this meteorite is a primary cumulate rock with close affinity to ALH77005 (and possibly to LEW88516), and is different from Shergotty. Strong shock effects. 30-50 GPa, are observed as finely fractured texture of pyroxene, maskelynite and brownish color olivine. Noble gas analyses by total melt and stepwise heating were performed on 17.86 and 50.99 mg primary igneous materials from Y-793605,10,respectively. Xe isotopic ratios show weak isotope signature for shergottite, which is different from those of nakhlites, Chassigny and ALH84001. Cosmic-ray exposure ages calculated from cosmogenic ^3He and ^Ne are 5.1-5.8 Ma, which is slightly longer than the ages, 3.3-4.0 Ma, reported for other two lherzolitic shergottites ALH77005 and LEW88516. Multistage exposure to cosmic-rays would be responsible for the difference. Apparent K-Ar age of 1430-1860 Ma is calculated, which is concordant with the young crystallization ages for martian meteorites, though the age is still ambiguous

Noble gases, chemical composition, and cosmic-ray exposure age of the Yamato-74357 lodranite

Cosmic-ray produced ^3He, ^Ne, and ^Ar concentrations and the chemical composition of the Yamato-74357 lodranite have been determined. Concordant concentrations of ^3He and ^Ne have been obtained on both samples (Bern and Misasa). The concentration of cosmogenic ^Ar is twice as high in the Bern as in the Misasa sample. The ^3He, ^Ne and ^Ar data for both samples yield an average cosmic-ray exposure age of 5.8±2.0Ma. This age indicates that Yamato-74357 belongs to the lodranite group, which probably originates from a common break-up event about 5Ma ago. Radiogenic ^4He and ^Ar concentrations in the Bern sample are higher than those in the Misasa sample by more than a factor of two, suggesting that minerals enriched in U, Th and K are enriched in the finer grained fraction. The isotopic compositions of Kr and Xe are identical to those of the terrestrial atmosphere, except for the ^Xe abundance. The small ^Xe excess (^Xe/^Xe=1.15±0.04) is presumably due to the early formation of this meteorite

Differential responses of normal human coronary artery endothelial cells against multiple cytokines comparatively assessed by gene expression profiles

AbstractEndothelial cells play an important role in terms of biological functions by responding to a variety of stimuli in the blood. However, little is known about the molecular mechanism involved in rendering the variety in the cellular response. To investigate the variety of the cellular responses against exogenous stimuli at the gene expression level, we attempted to describe the cellular responses with comprehensive gene expression profiles, dissect them into multiple response patterns, and characterize the response patterns according to the information accumulated so far on the genes included in the patterns. We comparatively analyzed in parallel the gene expression profiles obtained with DNA microarrays from normal human coronary artery endothelial cells (HCAECs) stimulated with multiple cytokines, interleukin-1β, tumor necrosis factor-α, interferon-β, interferon-γ, and oncostatin M, which are profoundly involved in various functional responses of endothelial cells. These analyses revealed that the cellular responses of HCAECs against these cytokines included at least 15 response patterns specific to a single cytokine or common to multiple cytokines. Moreover, we statistically extracted genes contained within the individual response patterns and characterized the response patterns with the genes referring to the previously accumulated findings including the biological process defined by the Gene Ontology Consortium (GO). Out of the 15 response patterns in which at least one gene was successfully extracted through the statistical approach, 11 response patterns were differentially characterized by representing the number of genes contained in individual criteria of the biological process in the GO only. The approach to dissect cellular responses into response patterns and to characterize the pattern at the gene expression level may contribute to the gaining of insight for untangling the diversity of cellular functions

Full-Length Sequence of Mouse Acupuncture-Induced 1-L (Aig1l) Gene Including Its Transcriptional Start Site

We have been investigating the molecular efficacy of electroacupuncture (EA), which is one type of acupuncture therapy. In our previous molecular biological study of acupuncture, we found an EA-induced gene, named acupuncture-induced 1-L (Aig1l), in mouse skeletal muscle. The aims of this study consisted of identification of the full-length cDNA sequence of Aig1l including the transcriptional start site, determination of the tissue distribution of Aig1l and analysis of the effect of EA on Aig1l gene expression. We determined the complete cDNA sequence including the transcriptional start site via cDNA cloning with the cap site hunting method. We then analyzed the tissue distribution of Aig1l by means of northern blot analysis and real-time quantitative polymerase chain reaction. We used the semiquantitative reverse transcriptase-polymerase chain reaction to examine the effect of EA on Aig1l gene expression. Our results showed that the complete cDNA sequence of Aig1l was 6073 bp long, and the putative protein consisted of 962 amino acids. All seven tissues that we analyzed expressed the Aig1l gene. In skeletal muscle, EA induced expression of the Aig1l gene, with high expression observed after 3 hours of EA. Our findings thus suggest that the Aig1l gene may play a key role in the molecular mechanisms of EA efficacy

p62/SQSTM1-droplet serves as a platform for autophagosome formation and anti-oxidative stress response

Autophagy contributes to the selective degradation of liquid droplets, including the P-Granule, Ape1-complex and p62/SQSTM1-body, although the molecular mechanisms and physiological relevance of selective degradation remain unclear. In this report, we describe the properties of endogenous p62-bodies, the effect of autophagosome biogenesis on these bodies, and the in vivo significance of their turnover. p62-bodies are low-liquidity gels containing ubiquitin and core autophagy-related proteins. Multiple autophagosomes form on the p62-gels, and the interaction of autophagosome-localizing Atg8-proteins with p62 directs autophagosome formation toward the p62-gel. Keap1 also reversibly translocates to the p62-gels in a p62-binding dependent fashion to activate the transcription factor Nrf2. Mice deficient for Atg8-interaction-dependent selective autophagy show that impaired turnover of p62-gels leads to Nrf2 hyperactivation in vivo. These results indicate that p62-gels are not simple substrates for autophagy but serve as platforms for both autophagosome formation and anti-oxidative stress. Liquid-liquid phase separation of p62/SQSTM1 has been previously described, although the significance in vivo remains unclear. Here the authors show p62 droplets contain ubiquitin, autophagy-related proteins and Keap1 to serve as platform of not only autophagosome formation but also Nrf2 activation.Peer reviewe