Paleoenvironmental Analyses of the Buried Peat Deposit during the mid-Holocene at the Desaki Coast in Tamano City, Okayama Prefecture, Weatern Japan

The buried peat deposit was foud in the sand beach on the Desaki coast (Tamano City, Okayama Prefecture), the northeastern coast of Seto Inland Sea. In this study, we performed sulfur and diatom analyses of the deposit. The results were used along with 14C dates and the eruption age (7300 cal BP) of Kikai-Akahoya tephra (K-Ab) to derive sedimentary environments of the deposit. K-Ah was detected just below the peat deposit. At the culmination of the Jomon transgression, the peat deposit had been formed in brackish environments of salt marsh for about 300 years. In order to reconstruct local paleovegetation, we analyzed pollen, wood and plant fossils in the deposit. The results show vegetational transition from a deciduous broadleaved forest mainly of Ouercus subgen. Lepidobalanus to Pinus forest. In spite of the Holocene thermal optimum, the vegetation dominated by Ouercus subgen. Cyclobanopsis was not recognized at the Desaki site, as has been shown in many other regions of regions of western Japan. Ouercus sect. Prinus was replaced by Ouercus sect. Aegilops as the dominant section of Ouercus subgen. Lepidobalanus, suggesting early establishment of traditional rural vegetation of 'Satoyama' in Japan. However, no evidence for human agency has been obtained from the mid-Holocene archaeological sites around the Desaki site. Thus it is more likely that this vegetational transition resulted from the succession caused by natural forces such as ecological disturbance and climatic and/or endemic situations rather than by cultural deforestation

An RNA aptamer with potent affinity for a toxic dimer of amyloid β42 has potential utility for histochemical studies of Alzheimer's disease

Oligomers of β-amyloid 42 (Aβ42), rather than fibrils, drive the pathogenesis of Alzheimer's disease (AD). In particular, toxic oligomeric species called protofibrils (PFs) have attracted significant attention. Herein, we report RNA aptamers with higher affinity toward PFs derived from a toxic Aβ42 dimer than toward fibrils produced from WT Aβ42 or from a toxic, conformationally constrained Aβ42 variant, E22P–Aβ42. We obtained these RNA aptamers by using the preincubated dimer model of E22P–Aβ42, which dimerized via a linker located at Val-40, as the target of in vitro selection. This dimer formed PFs during incubation. Several physicochemical characteristics of an identified aptamer, E22P–AbD43, suggested that preferential affinity of this aptamer toward PFs is due to its higher affinity for the toxic dimer unit (KD = 20 ± 6.0 nm) of Aβ42 than for less-toxic Aβ40 aggregates. Comparison of CD data from the full-length and random regions of E22P–AbD43 suggested that the preferential binding of E22P–AbD43 toward the dimer might be related to the formation of a G-quadruplex structure. E22P–AbD43 significantly inhibited the nucleation phase of the dimer and its associated neurotoxicity in SH-SY5Y human neuroblastoma cells. Of note, E22P–AbD43 also significantly protected against the neurotoxicity of WT Aβ42 and E22P–Aβ42. Furthermore, in an AD mouse model, E22P–AbD43 preferentially recognized diffuse aggregates, which likely originated from PFs or higher-order oligomers with curvilinear structures, compared with senile plaques formed from fibrils. We conclude that the E22P–AbD43 aptamer is a promising research and diagnostic tool for further studies of AD etiology

Mycobacterium chelonae bloodstream infection induced by osteomyelitis of toe: A case report

Mycobacterium chelonae is a rapidly growing mycobacterium that has the potential to cause refractory infections in humans. Mycobacteremia resulting from the organism is extremely rare, and its clinical features are yet to be uncovered. We herein present a case of M. chelonae bloodstream infection involving an immunocompromised older patient. A 79-year-old woman, on a long-term treatment with prednisolone plus tacrolimus for rheumatoid arthritis, visited our outpatient department complaining of deteriorating pain and swelling at her right 1st toe. Laboratory parameters showed elevated C-reactive protein and leukocytosis, and magnetic resonance imaging indicated osteomyelitis at the proximal phalanx of her right 1st toe. Considering the refractory course, the infected toe was immediately amputated. M. chelonae was isolated from bacterial cultures of the resected tissue and blood (BD BACTEC™ FX blood culture system, Becton Dickinson, Sparks, MD, USA), leading to a diagnosis of disseminated M. chelonae infection. We treated the patient with an antibiotic combination of clarithromycin, minocycline, and imipenem (2 weeks), which was converted to oral therapy of clarithromycin, doxycycline, and levofloxacin. This case highlighted the potential pathogenesis of M. chelonae to cause mycobacteremia in an immunocompromised patient

The Creation of School Education Bringing up a Student Carrying Tomorrow (3) : The Valuation of "Compulsory Subjects", "Optional Subjects", and "Integrated Subjects"

The purpose of this study is to show the valuation of "Compulsory Subjects", "Optional Subjects", and "Integrated Subjects", to show the relationship between each subjects and "three abilities", "the ability of recognizing othere senses of value", "the ability of self-expression and communication" and "the ability of decision-making" which defined by the project members. The main result of this study is that we should make up the standards which teachers, students and parents recognize as important abilities

Insight into the Regulation of Glycan Synthesis in Drosophila Chaoptin Based on Mass Spectrometry

BACKGROUND: A variety of N-glycans attached to protein are known to involve in many important biological functions. Endoplasmic reticulum (ER) and Golgi localized enzymes are responsible to this template-independent glycan synthesis resulting glycoforms at each asparagine residues. The regulation mechanism such glycan synthesis remains largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: In order to investigate the relationship between glycan structure and protein conformation, we analyzed a glycoprotein of Drosophila melanogaster, chaoptin (Chp), which is localized in photoreceptor cells and is bound to the cell membrane via a glycosylphosphatidylinositol anchor. Detailed analysis based on mass spectrometry revealed the presence of 13 N-glycosylation sites and the composition of the glycoform at each site. The synthetic pathway of glycans was speculated from the observed glycan structures and the composition at each N-glycosylation site, where the presence of novel routes were suggested. The distribution of glycoforms on a Chp polypeptide suggested that various processing enzymes act on the exterior of Chp in the Golgi apparatus, although virtually no enzyme can gain access to the interior of the horseshoe-shaped scaffold, hence explaining the presence of longer glycans within the interior. Furthermore, analysis of Chp from a mutant (RNAi against dolichyl-phosphate alpha-d-mannosyltransferase), which affects N-glycan synthesis in the ER, revealed that truncated glycan structures were processed. As a result, the distribution of glycoforms was affected for the high-mannose-type glycans only, whereas other types of glycans remained similar to those observed in the control and wild-type. CONCLUSIONS/SIGNIFICANCE: These results indicate that glycan processing depends largely on the backbone structure of the parent polypeptide. The information we obtained can be applied to other members of the LRR family of proteins

Association of Tannins and Related Polyphenols with the Cyclic Peptide Gramicidin S

The association of 10 different tannins and related polyphenols with gramicidin S, a cyclic peptide having a rigid β-turn structure, has been examined using 1H-NMR spectroscopy. In the presence of pentagalloylglucose and epigallocatechin-3-O-gallate, the proton signals due to proline and the adjacent phenylalanine moieties selectively shifted to up field, suggesting a regioselective association with the β-turn structure. The association was also supported by the observation of intermolecular nuclear Overhauser effects between epigallocatechin-3-O-gallate and the peptide. In contrast, ellagitannins, biogenetically derived from pentagalloylglucose, showed small and non-selective chemical shift changes, suggesting that interaction with these tannins is relatively weak. The hydrophobicity of the tannin molecules and the steric hindrance of the interaction site are thought to be important in the association

Molecular characterization of genes essential for early development of germ cells in rice

　In flowering plants, after the transition from vegetative growth to reproductive development, primordial germ cell initials differentiate from somatic cells in flowers. Several genes that control the early stages of germ-cell development have been identified, however, little is known about the molecular mechanism determining the germ cell fate during sexual reproduction in plants. The MEL1 (MEIOSIS ARRESIED ATLEPTOTENE1) is the only plant ARGONAUTE (AGO) gene specifically expressing at the primordial germ cells. AGO proteins are known to be a key player in gene-silencing pathways guided by small RNAs. PlWl-domain containing subfamily has important roles in maintaining germ stem cells in animal. In plant, however, there is no AGO gene which belonging to PIWI subfamily. Therefore, a specific AGO gene system in plant germ cell development would be suggested.　In this study, I focused on the characterization gene expressed at early stages of germ cells development specifically in relation to the MEL1 function. MEL1 is well-characterized ARGONAUTE family that has essential functions in germ cell development. To date the rice MEL1 is the only gene available for investigating a genetic system conducting plant germ cell initiation and maintenance. A large portion of the genes identified specific in very early stages in germ cell development had unknown function However, comparison of gene expression profiles between wild-type and mell-1 mutant down- or up-regulated inmell-1 mutant revealed many possible causal genes for mell-1 dysfunction, i.e. most of which are not characterized previously. Of these genes, the OsSPLl4, one of SQUAMOSA(SQUA) promoter-binding-like(SPL) family genes, encoding a putative transcription factor, revealed to up-regulated in the mell-l mutant in both Affymetrix (Fold change=4.37) and Agilent (=3.01) microarray. Sequence and experimental analyses indicated that eleven OsSPL genes including OsSPL14 were putative targets of OsmiR156, suggesting a possibility that the OsSPL14 should be directly targeted by the rice MEL1 AGO with miR156 microRNA as a guide molecule. Moreover, the volume of miR156 RNA detected in the co-IP fraction with the anti-MEL1antibody 3.2-fold more than in that with the pre-immune serum. The detection level of miRl56 depended on that of the MEL1 protein, as the miR156 co-IP with the MEL1 immune complex protein, but few or not with precipitates recovered using mell-1 mutant or preimmune serum. These data strongly suggest that the MEL1forms a complex with the miR156 microRNA in vivo. These results strongly suggested that the miR156microRNA was one of good candidates of guide RNA molecules of the MEL1 AGO.　Analysis performed in each section and results obtained from the analysis are summarized as follows.　In the Section 1, the whole transcriptome profiles of plant reproductive process, including early stages that are difficult to be dissected in Arabidopsis, was obtained by using the Affymetrix rice genome array analysis and provided as a dataset of rice reproductive expression atlas. In addition, using the atlas data, the gene expression patterns of several genes that the are highly expressed in early development stage were investigated. A large part of genes that are expressed in early reproductive development remains uncharacterized because most of pre-meiotic stage specific genes were not categorized to any functions by GO analysis. However, the expression patterns of other meiosis-related genes were well corresponded previous reports. The specific genes that were found in this study may have the crucial function at early germ cells development stages.　In the section 2, to confirm the spatial and temporal expression of the MEL1 gene, mRNA in situ hybridization was performed on the anther sections with the MSP1 gene as cellular marker of young anther tissues. Expression of the MEL1 was earlier than that of the MSP1, which clearly indicates that the MEL1mRNA expression start at the archesporial initials. The MEL1 expression is not required for the germ-cell initiation, but for the maintenance of germ cells. In the Section 2, in situ hybridization of the OsNOZZLE(OsNZZ), a putative rice ortholog of Arabidopsis SPOLOCYTELESS|NOZZLE was also performed. Different from the MEL1 and the, MSP1,the OsNZZ mRNA was expressed both in developing anther wall layers and sporogenous cells similar that of Arabidopsis SPL/NZZ, but it was not detected in archesporial cells. Although their function is not the same as Arabidopsis SPL/NZZ, OsNZZ may have function in early germ cell development.　In the Section 3, the microarray at 1-cm young panicle, several genes responsive for environmental stresses and/or hormone-responsive genes up-regulated. It suggests that absence of the MEL1 may cause stressful condition, thus many stress-response genes and ethylene signaling-related gene are induced. TheMEL1 may inhibits stress responses in germ cells to accomplish precise germ cell division and meiosis. In addition, some transposable element-like transcripts were also up-regulated in mel-1 mutant. It was demonstrated that Drosophila piwi mutations impact retrotransposon mobility. MEL1 may also suppress the activity of transposable elements during rice germ-cell development. On the other hand, many genes related to cell structure and cycle were down-regulated in the mell-1 mutant. These results may indicated that inmell-1 mutant, the failure of pre-meiotic mitosis of sporogenous cells in the mell-1 mutant anther (Nonomura et al. 2007) was caused by down-regulation of these genes. At pre-meiotic S/G2 stage of young anthers, few genes were affected by the mell-1 mutation. Most of up- and down-regulation of genes in the later stages of pre-meiotic germ-cell development might be secondary effects of mell-1 mutation.　Finally, the Section 4 suggested a possibility that the rice MEL1 AGO directly regulated the OsSPL14gene with the plant specific microRNA, miR156 as described above.　Results obtained in this thesis will provide new and useful information to understand the gene functions in initiation of germ cells development and maintenance of germ cell identity in rice