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41.
The acidic pH-sensitive controlled release of fibroblast growth factor-2 (FGF-2) from a biodegradable hydrogel without any denaturation of the FGF-2 was successfully performed by a combination of FGF-2 activity and acidic pH-sensitivity. We prepared semi-interpenetrating polymer network like hetero-gels (S72-netgels) composed of poly(gamma-glutamic acid) (gamma-PGA) and 72% sulfonated gamma-PGA (gamma-PGA-S72). S72-netgels including 36 mol % sulfonic acid (S72-netgel-36) showed wide acidic pH-sensitive deswelling properties at pH = 2.0-6.0, corresponding to the isoelectric point of carboxylic acid, because of the concentration of protons due to the neighboring sulfonic acids from the carboxylic acids. The S72-netgel-36 (the volume of hydrogel is 7.85 x 10(-2) cm3) can incorporate 280 ng of FGF-2 after 24 h immersion in Tris-HCl buffer (pH = 7.4), including 1.0 microg of FGF-2. The S72-netgel-36 still retained about 60% of the FGF-2 even after 15 days of incubation in fresh Tris-HCl buffer at 37 degrees C because of the stable interaction of FGF-2 with gamma-PGA-S72 in S72-netgel-36. The release of FGF-2 from the S72-netgel-36 was successfully controlled by alternating immersion in pH = 7.4 and acidic pH buffers. Furthermore, the FGF-2 released from the S72-netgel-36 retained its activity without denaturation because the gamma-PGA-S72 in S72-netgel-36 has a protective activity. The acidic pH-sensitive FGF-2 release property of the S72-netgel-36 without denaturation of the FGF-2 may be useful for tissue engineering fields such as neovascular treatment for ischemia and inflammation. 相似文献
42.
Two species ofMenziesia, M. katsumatae andM. yakushimensis, are described as new to science. The former is characterized by having a long axis of the inflorescence with 15–20 bracts
while the other species has a short axis with about ten bracts.M. katsumatae is restricted to the Hakusan range extending northward to Mt. Hōdatsuzan in the Noto Peninsula.M. yakushimensis has been considered asM. purpurea Maxim. in Kyūshū, but it is clearly distinguishable from the latter by the color and shape of the corolla and the presence
of fasciculate glandular-hairs at the base of the corolla lobes. It is endemic to the higher altitudes of Yaku-shima Island,
Kagoshima Prefecture. 相似文献
43.
Michiya Matsuyama Ricardo Torres Lara Shuhei Matsuura 《Environmental Biology of Fishes》1988,21(1):27-36
The histology of the gonad of the red sea bream,Pagrus major, was examined in order to study the early gonadal development, sexual maturation and sex ratio in a natural population. A
total of 1,117 fish between the ages of 4 months and 8 years were examined. Gonads of 4-month-old fish were either sexually
undifferentiated with a central cavity, or ovarian in form. Gonads of 12- and 18-month-old fish were ovaries or bisexual gonads,
while those of 2-year-old fish were ovaries, bisexual gonads or testes. Fish aged between 3 and 8 years had ovaries or testes,
except for a few bisexual gonads found in 3- and 4-year-old fish. The chronological appearance of females, hermaphrodites
and males in that order, and histological evidence, suggested that the testis originates from the ovary via a bisexual gonad
in the juvenile stage. The sex ratio of females to males at the age of 2 years and over was about 1:1, suggesting that hermaphroditic
red sea bream appear in about 50% of the juvenile population. The sexual pattern in this species, therefore, is concluded
to be gonochorism with a bisexual juvenile stage. 相似文献
44.
45.
Kadowaki K Matsusaki M Akashi M 《Biochemical and biophysical research communications》2010,394(1):153-157
Naofen has recently been identified from the rat brain/spinal cord cDNA library as a substance reactive against an anti-shigatoxin (Stx)-2 antibody. Naofen mRNA is composed of 4620 nucleotides and encodes 1170 amino acids. Naofen contains four WD-repeat domains in its N-terminus and is ubiquitously distributed in many tissues of the rat. Tumor necrosis factor (TNF)-α enhanced the expression of naofen mRNA in HEK293 cells in a dose-dependent manner. Furthermore, naofen siRNA, which predominantly knocked down the expression of naofen mRNA, significantly reduced both TNF-α-induced caspase-3 activation and apoptosis in HEK293 cells. Overexpression of naofen in HEK293 cells (FLAG-NF) spontaneously induced caspase -3 activation and apoptosis, and showed extremely high susceptibility to TNF-α-induced apoptosis. These results indicated that naofen may function as a novel modulator activating caspase-3, and promoting TNF-α-stimulated apoptosis. 相似文献
46.
Nishino M Kurasawa Y Evans R Lin SH Brinkley BR Yu-Lee LY 《Current biology : CB》2006,16(14):1414-1421
The equal distribution of chromosomes during mitosis is critical for maintaining the integrity of the genome. Essential to this process are the capture of spindle microtubules by kinetochores and the congression of chromosomes to the metaphase plate . Polo-like kinase 1 (Plk1) is a mitotic kinase that has been implicated in microtubule-kinetochore attachment, tension generation at kinetochores, tension-responsive signal transduction, and chromosome congression . The tension-sensitive substrates of Plk1 at the kinetochore are unknown. Here, we demonstrate that human Nuclear distribution protein C (NudC), a 42 kDa protein initially identified in Aspergillus nidulans and shown to be phosphorylated by Plk1 , plays a significant role in regulating kinetochore function. Plk1-phosphorylated NudC colocalizes with Plk1 at the outer plate of the kinetochore. Depletion of NudC reduced end-on microtubule attachments at kinetochores and resulted in defects in chromosome congression at the metaphase plate. Importantly, NudC-deficient cells exhibited mislocalization of Plk1 and the Kinesin-7 motor CENP-E from prometaphase kinetochores. Ectopic expression of wild-type NudC, but not NudC containing mutations in the Plk1 phosphorylation sites, recovered Plk1 localization at the kinetochore and rescued chromosome congression. Thus, NudC functions as both a substrate and a spatial regulator of Plk1 at the kinetochore to promote chromosome congression. 相似文献
47.
SSR-based linkage map with new markers using an intraspecific population of common wheat 总被引:14,自引:0,他引:14
Torada A Koike M Mochida K Ogihara Y 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,112(6):1042-1051
Simple sequence repeats (SSRs) are valuable molecular markers in many plant species. In common wheat (Triticum aestivum L.), which is characteristic of its large genomes and alloploidy, SSRs are one of the most useful markers. To increase SSR
marker sources and construct an SSR-based linkage map of appropriate density, we tried to develop new SSR markers from SSR-enriched
genomic libraries and the public database. SSRs having (GA)n and (GT)n motifs were isolated from enriched libraries, and di-
and tri-nucleotide repeats were mined from expressed sequence tags (ESTs) and DNA sequences of Triticum species in the public database. Of the 1,147 primer pairs designed, 842 primers gave accurate amplification products, and
478 primers showed polymorphism among the nine wheat lines examined. Using a doubled haploid (DH) population from an intraspecific
cross between Kitamoe and Münstertaler (KM), we constructed an SSR-based linkage map that consisted of 464 loci: 185 loci
from genomic libraries, 65 loci from the sequence database including ESTs, 213 loci from the SSR markers already reported,
and 1 locus of morphological marker. Although newly developed SSR loci were distributed throughout all chromosomes, clustering
of them around putative centromeric regions was found on several chromosomes. The total length of the KM map spanned 3,441 cM
and corresponded to approximately 86% genome coverage. The KM map comprised of 23 linkage groups because two gaps of over
50 cM distance remained on chromosome 6A. This is a first report of SSR-based linkage map using single intraspecific population
of common wheat. This mapping result suggests that it becomes possible to construct linkage maps with sufficient genome coverage
using only SSR markers without RFLP markers, even in an intraspecific population of common wheat. Moreover, the new SSR markers
will contribute to the enrichment of molecular marker resources in common wheat. 相似文献
48.
Yasuhiko Soejima Jae Man Lee Yudai Nagata Hiroaki Mon Kazuhiro Iiyama Hajime Kitano Michiya Matsuyama Takahiro Kusakabe 《Central European Journal of Biology》2013,8(1):1-7
The baculovirus-silkworm expression system is widely used as a mass production system for recombinant secretory proteins. However, the final yields of some recombinant proteins are not sufficient for industrial use. In this study, we focused on the signal peptide as a key factor for improving the efficiency of protein production. Endoplasmic reticulum (ER) translocation of newly synthesized proteins is the first stage of the secretion pathway; therefore, the selection of an efficient signal peptide would lead to the efficient secretion of recombinant proteins. The Drosophila Bip and honeybee melittin signal peptides have often been used in this system, but to the best of our knowledge, there has been no study comparing secretion efficiency between exogenous and endogenous signal peptides. In this study we employed signal peptides from 30K Da and SP2 proteins as endogenous signals, and compared secretion efficiency with those of exogenous or synthetic origins. We have found that the endogenous secretory signal from the 30K Da protein is the most efficient for recombinant secretory protein production in the baculovirus-silkworm expression system. 相似文献
49.
Kohji Takahashi Reiji Masuda Michiya Matsuyama Yoh Yamashita 《Journal of Ethology》2012,30(2):309-316
Marine fishes often experience major habitat shifts during their life history, and previous studies have shown that the learning
capability of fish change ontogenetically and in accordance with such habitat shifts. However, because all of these studies
used a single type of conditioned stimuli (CS), they failed to detect qualitative changes in learning capability. Here we
tested the hypothesis that preparedness for learning changes ontogenetically in jack mackerel Trachurus japonicus, which undergo a drastic change in habitat preference during their life history as they move from offshore pelagic waters
to coastal and demersal rocky reefs. Groups of juveniles measuring 40 mm standard length (SL) (pelagic stage) and 60 mm SL
(demersal stage) were conditioned to food rewards in response to three different CS; the presence of a surface structure,
mid-water structure, and aeration. The results showed that small juveniles tended to become conditioned to the surface stimulus
faster than they did to the mid-water stimulus. Conversely, large juveniles responded to the mid-water stimulus significantly
more quickly than they did to the surface stimulus. These results suggest that stimulus-specific learning capability in T. japonicus changes ontogenetically, facilitating adaptation to their life-history strategy. 相似文献
50.
Sugawara M Kurosawa M Sakai K Kobayashi M Iseki K Miyazaki K 《Biochimica et biophysica acta》2002,1564(1):149-155
The effects of transmembrane electric potential difference and ionic strength on the permeation of tryptamine and indoleacetic acid across a Caco-2 cell monolayer were examined. A decrease in the transmembrane electric potential difference caused by the addition of potassium ion to the transport buffer had no effect on the permeation rate of either compound. On the other hand, an increase in ionic strength resulted in a decrease in the permeation rate of tryptamine and an increase in the permeation rate of indoleacetic acid. The changes in the permeation rate with changes in the ionic strength were correlated with the membrane surface potential monitored by 1-anilino-8-naphthalenesulfonic acid (ANS), a fluorescent probe. We tested these effects using several other cationic and anionic compounds. These effects of ionic strength were found to be common to all drugs tested. The compound that showed a relatively lower permeation rate was given relatively stronger effect. The possibility of overestimation or underestimation caused by these effects should be considered when the permeation of an ionic compound is evaluated using a cell monolayer system. 相似文献