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981.
Kenji Seiwa Munetaka Tozawa Naoto Ueno Megumi Kimura Miki Yamasaki Kaoru Maruyama 《Plant Ecology》2008,198(1):27-35
Willows usually establish on wet substrates with fine sediments at sites that are created by large disturbances, but suitable
microsites are spatially and temporally limited. Thus, we hypothesized that willow seeds are selectively dispersed to suitable
microsites, such as those with a wet substrate, rather than unsuitable microsites, such as those with a dry substrate, with
seedling establishment mediated by the cottony hairs attached to seeds (directed dispersal). To test our hypothesis, we compared
several recruitment-related traits, including buoyancy, germination, and trapping at favorable microsites, in seeds of the
riparian willows Salix sachalinensis and S. integra with and without cottony hairs in laboratory and field experiments. In both field and laboratory experiments, more seeds
with cottony hairs were trapped in water and wet sand than in dry sand, in which no seeds of either species germinated. These
results indicate that cottony hairs facilitate the recruitment of seeds to microsites favorable for seed germination and help
seeds avoid unfavorable microsites. On the water surface, 17.6% of S. sachalinensis seeds and 68.0% S. integra seeds with cottony hairs floated for more than 6 days, whereas all seeds without cottony hairs sank immediately after being
placed on the water surface. These results suggest that cottony hairs facilitate long-distance dispersal via flowing water
and also help avoid germination under water, where willow seedlings fail to establish. Seeds of the two willow species were
released from the cottony hairs and germinated immediately after the seeds were placed on wet sand, but not after placement
on water or dry sand. These results suggest that the seeds are released from the cottony hairs when the hairs become wet and
the seeds are striking to a suitable microsite for seedling establishment, such as wet sand. In riparian willows, the cottony
hairs promote directed dispersal by moving seeds to discrete and predictable microsites where the seedling establishment is
disproportionately high. 相似文献
982.
Takishita K Fujiwara Y Kawato M Kakizoe N Miyazaki M Maruyama T 《Marine biotechnology (New York, N.Y.)》2008,10(1):13-18
A protist tentatively designated “Pseudoperkinsus tapetis” belonging to the eukaryotic group Ichthyosporea (Mesomycetozoa) was previously isolated from carpet shell clams in Galicia
(northwest Spain). In the present study, based on molecular data, a potential P. tapetis specimen was identified from the gill tissues of the mussel Adipicola pacifica associated with whale carcasses (generating chemosynthetic-based ecosystems) collected at shelf depths in the northwest Pacific
(southwest Japan). Small subunit ribosomal DNA sequences (1751 sites) of the genotypes of P. tapetis from Spain and Japan were almost identical (only one substitution and one insertion/deletion difference). On the other hand,
differences of 10 and 8 substitutions were found in two internal transcribed spacer regions of ribosomal DNA, ITS1 (288 sites)
and ITS2 (251 sites) between these two genotypes, respectively, indicating that they are genetically different at the population
level. These findings suggest that P. tapetis occurs worldwide and can associate with (and possibly infect) various types of bivalves. Further, a PCR method to specifically
detect the P. tapetis cells in the host was also established. 相似文献
983.
Background Context
Research employing gait measurements indicate asymmetries in ground reaction forces and suggest relationships between these asymmetries, neurological dysfunction and spinal deformity. Although, studies have documented the use of centre of pressure (CoP) and net joint moments in gait assessment and have assessed centre of mass (CoM)-CoP distance relationships in clinical conditions, there is a paucity of information relating to the moments about CoM. It is commonly considered that CoM is situated around S2 vertebra in normal upright posture and hence this study uses S2 vertebral prominence as reference point relative to CoM.Purpose
To assess and establish asymmetry in the CoP pattern and moments about S2 vertebral prominence during level walking and its relationship to spinal deformity in adolescents with scoliosis.Patient sample
Nine Adolescent Idiopathic Scoliosis subjects (8 females and 1 male with varying curve magnitudes and laterality) scheduled for surgery within 2–3 days after data collection, took part in this study.Outcome measures
Kinetic and Kinematic Gait assessment was performed with an aim to estimate the CoP displacement and the moments generated by the ground reaction force about the S2 vertebral prominence during left and right stance during normal walking.Methods
The study employed a strain gauge force platform to estimate the medio-lateral and anterior-posterior displacement of COP and a six camera motion analysis system to track the reflective markers to assess the kinematics. The data were recorded simultaneously.Results
Results indicate wide variations in the medio lateral direction CoP, which could be related to the laterality of both the main and compensation curves. This variation is not evident in the anterior-posterior direction. Similar results were recorded for moments about S2 vertebral prominence. Subjects with higher left compensation curve had greater displacement to the left.Conclusion
Although further longitudinal studies are needed, results indicate that the variables identified in this study are applicable to initial screening and surgical evaluation of scoliosis. 相似文献984.
985.
Law M Maruyama T Lewis J Giang E Tarr AW Stamataki Z Gastaminza P Chisari FV Jones IM Fox RI Ball JK McKeating JA Kneteman NM Burton DR 《Nature medicine》2008,14(1):25-27
A major problem in hepatitis C virus (HCV) immunotherapy or vaccine design is the extreme variability of the virus. We identified human monoclonal antibodies (mAbs) that neutralize genetically diverse HCV isolates and protect against heterologous HCV quasispecies challenge in a human liver-chimeric mouse model. The results provide evidence that broadly neutralizing antibodies to HCV protect against heterologous viral infection and suggest that a prophylactic vaccine against HCV may be achievable. 相似文献
986.
Diabetic nephropathy in KK and KK-Ay mice. 总被引:4,自引:0,他引:4
Masako Okazaki Yukako Saito Yuko Udaka Mine Maruyama Hidetomo Murakami Sumiko Ota Takuya Kikuchi Katsuji Oguchi 《Experimental Animals》2002,51(2):191-196
KK mice and KK-Ay mice were examined for age related changes in blood and urinary biophysiological parameters. Blood hemoglobin A1c levels were significantly higher in KK-Ay and KK mice as compared to non-diabetic ddY mice. In both diabetic mice, especially KK-Ay mice, plasma insulin levels markedly increased at 2 to 4 months of age, and the urinary glucose and microalbumin levels and albumin-to-creatinine ratios increased dependent on age. Plasma thrombomodulin levels significantly increased at 2 to 4 months of age in both KK and KK-Ay mice. Mild enlargement of mesangial matrix and segmental proliferative glomerular nephritis were revealed in KK and KK-Ay mice, respectively, at 4 months of age. KK-Ay mice with insulin resistance and high urine mAlb level might be useful as models for the early stage of diabetic nephropathy. 相似文献
987.
The minimal eukaryotic ribosomal DNA units in the primitive red alga Cyanidioschyzon merolae. 总被引:1,自引:0,他引:1
Shinichiro Maruyama Osami Misumi Yasuyuki Ishii Shuichi Asakawa Atsushi Shimizu Takashi Sasaki Motomichi Matsuzaki Tadasu Shin-i Hisayoshi Nozaki Yuji Kohara Nobuyoshi Shimizu Tsuneyoshi Kuroiwa 《DNA research》2004,11(2):83-91
Cyanidioschyzon merolae is a small unicellular red alga that is considered to belong to one of the most deeply branched taxa in the plant kingdom. Its genome size is estimated to be 16.5 Mbp, one of the smallest among free-living eukaryotes. In the nucleus containing this small genome, one nucleolus is clearly observed, but the molecular basis for the intranuclear structure including ribosomal DNA organization is still unclear. We constructed a bacterial artificial chromosome library for C. merolae 10D composed of two subsets with different insert size distributions. The two subsets have average insert sizes of 97 and 48 kb, representing 10.0- and 6.9-fold genome-equivalent coverage of the haploid genome, respectively. For application to whole-genome shotgun sequencing, the termini of each clone were sequenced as sequence-tagged connectors and mapped on the contigs assigned to chromosomes. Screening for rRNA genes by conventional colony hybridization with high-density filter blots and subsequent sequencing revealed that the C. merolae genome contained the smallest number of ribosomal DNA units among all the eukaryotes examined to date. They consist of only 3 single units of rRNA genes distributed on separate chromosomal loci, representing an implication for concerted evolution. Based on these results, the origin and evolution of the nucleolus are discussed. 相似文献
988.
Miyamoto-Matsubara M Saitoh O Maruyama K Aizaki Y Saito Y 《Cellular signalling》2008,20(11):2084-2094
Melanin-concentrating hormone (MCH) receptor 1 (MCH1R) belongs to the class A G protein-coupled receptors (GPCRs). The MCH-MCH1R system plays a central role in energy metabolism, and thus the regulation of signaling pathways activated by this receptor is of particular interest. Regulator of G protein signaling (RGS) proteins work by increasing the GTPase activity of G protein alpha subunits and attenuate cellular responses coupled with G proteins. Recent evidence has shown that RGS proteins are not simple G protein regulators but equally inhibit the signaling from various GPCRs. Here, we demonstrate that RGS8, which is highly expressed in the brain, functions as a negative modulator of MCH1R signaling. By using biochemical approaches, RGS8 was found to selectively and directly bind to the third intracellular (i3) loop of MCH1R in vitro. When expressed in HEK293T cells, RGS8 and MCH1R colocalized to the plasma membrane and RGS8 potently inhibited the calcium mobilization induced by MCH. The N-terminal 9 amino acids of RGS8 were required for the optimal capacity to downregulate the receptor signaling. Furthermore, Arg(253) and Arg(256) at the distal end of the i3 loop were found to comprise a structurally important site for the functional interaction with RGS8, since coexpression of RGS8 with R253Q/R256Q mutant receptors resulted in a loss of induction of MCH-stimulated calcium mobilization. This functional association suggests that RGS8 may represent a new therapeutic target for the development of novel pharmaceutical agents. 相似文献
989.
Kimura S Maruyama J Takeuchi M Kitamoto K 《Bioscience, biotechnology, and biochemistry》2008,72(2):499-505
Aspergillus oryzae has numerous protease genes that might cause proteolytic degradation of heterologously-produced proteins. The productivity of the heterologous protein can be improved by protease gene disruption, but it is difficult to select disruption targets efficiently. In this study, we monitored the expression of 132 protease genes by DNA microarray. A group of protease genes up-regulated during cultivation was identified by clustering analysis. In this protease group, the nptB gene encoding neutral protease II was included as well as the alpA, tppA, and pepA genes, disruption of which has improved human lysozyme (HLY) production. The nptB gene was disrupted to investigate its involvement in HLY production, and nptB disruptants showed an improvement in the production. These observations suggest that monitoring the expression of protease genes is an efficient strategy in screening potential disruption targets for heterologous protein production in A. oryzae. 相似文献
990.
Nakato T Tago R Akiyama K Maruyama M Sugahara T Kishida T Yamauchi S 《Bioscience, biotechnology, and biochemistry》2008,72(1):197-203
Tetra-substituted tetrahydrofuran compounds were stereoselectively prepared from benzylic hemiacetal in the neutral condition by employing the simple reagent, H(2), and a Pd catalyst. The stereoselective conversion of benzylic hemiacetal to two different stereoisomers of the tetrasubstituted tetrahydrofuran compound was observed. One of these tetrahydrofuran compounds was converted to the virgatusin stereoisomer to estimate its antimicrobiological activity. 相似文献