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991.
992.
Takashi Kitagawa Shingo Kimura Hideaki Nakata Harumi Yamada Akira Nitta Yoshikazu Sasai Hideharu Sasaki 《Environmental Biology of Fishes》2009,84(2):193-196
The habitat and movements of a Pacific bluefin tuna were investigated by reanalyzing archival tag data with sea surface temperature
data. During its trans-Pacific migration to the eastern Pacific, the fish took a direct path and primarily utilized waters,
in the Subarctic Frontal Zone (SFZ). Mean ambient temperature during the trans-Pacific migration was 14.5 ± 2.9 (°C ± SD),
which is significantly colder than the waters typically inhabited by bluefin tuna in their primary feeding grounds in the
western and eastern Pacific (17.6 ± 2.1). The fish moved rapidly through the colder water, and the heat produced during swimming
and the thermoconservation ability of bluefin tuna likely enabled it to migrate through the cold waters of the SFZ. 相似文献
993.
Toll-like receptor expression in normal ovary and ovarian tumors 总被引:1,自引:0,他引:1
Mingfu Zhou Molly M. McFarland-Mancini Holly M. Funk Nader Husseinzadeh Taofic Mounajjed Angela F. Drew 《Cancer immunology, immunotherapy : CII》2009,58(9):1375-1385
Recent studies have implicated inflammation in the initiation and progression of ovarian cancer, though the mechanisms underlying
this effect are still not clear. Toll-like receptors (TLRs) allow immune cells to recognize pathogens and to trigger inflammatory
responses. Tumor cell expression of TLRs can promote inflammation and cell survival in the tumor microenvironment. Here we
sought to characterize the expression of TLRs in normal human ovaries, benign and malignant ovarian tumors from patients,
and in established ovarian tumor cell lines. We report that TLR2, TLR3, TLR4, and TLR5 are strongly expressed on the surface
epithelium of normal ovaries. In contrast to previous studies of uterus and endocervix, we found no cyclic variation in TLR
expression occurred in murine ovaries. TLR2, TLR3, TLR4, and TLR5 are expressed in benign conditions, epithelial tumors, and
in ovarian cancer cell lines. Variable expression of TLR6 and TLR8 was seen in benign and malignant epithelium of some patients,
while expression of TLR1, TLR7, and TLR9 was weak. Normal and malignant ovarian stroma were negative for TLR expression. Vascular
endothelial cells, macrophages, and occasional fibroblasts in tumors were positive. Functional activity for TLRs was demonstrated
by stimulation of cell lines with specific ligands and subsequent activation and translocation of NFκB and release of the
proinflammatory cytokines interleukin-6 and CCL-2. These studies demonstrate expression of multiple TLRs in the epithelium
of normal ovaries and in ovarian tumor cells, and may indicate a mechanism by which epithelial tumors manipulate inflammatory
pathways to facilitate tumor progression. 相似文献
994.
Steffen Harzsch Carsten H. G. Müller Verena Rieger Yvan Perez Silvia Sintoni Christian Sardet Bill Hansson 《Zoomorphology》2009,128(1):53-73
The enigmatic arrow worms (Chaetognatha) are marine carnivores and among the most abundant planktonic organisms. Their phylogenetic
position has been heavily debated for a long time. Most recent molecular studies still provide a diverging picture and suggest
arrow worms to be some kind of basal protostomes. In an effort to understand the organization of the nervous system in this
clade for a broad comparison with other Metazoa we analysed the ultrastructure of the ventral nerve centre in Spadella cephaloptera by transmission electron microscopy. We were able to identify six different types of neurons in the bilateral somata clusters
by means of the cytoplasmic composition (regarding the structure of the neurite and soma including the shape and eu-/heterochromatin
ratio within the nucleus) as well as the size and position of these neurons. Furthermore, our study provides new insights
into the neuropil composition of the ventral nerve centre and several other fine structural features. Our second goal was
to examine if individually identifiable neurons are present in the ventral nerve centres of four chaetognath species, Sagitta setosa, Sagitta enflata, Pterosagitta draco, and Spadella cephaloptera. For that purpose, we processed whole mount specimens of these species for immunolocalization of RFamide-related neuropeptides
and analysed them with confocal laser-scanning microscopy. Our experiments provide evidence for the interspecific homology
of individual neurons in the ventral nerve centres of these four chaetognath species suggesting that the potential to generate
serially arranged neurons with individual identities is part of their ground pattern. 相似文献
995.
Yu. E. Elisseeva E. V. Kugaevskaya 《Biochemistry (Moscow) Supplemental Series B: Biomedical Chemistry》2009,3(3):237-247
Somatic angiotensin converting enzyme (ACE) consists of two homologous catalytic domains (N- and C-domain), exhibiting different biochemical properties. The catalytically active ACE isoforms consisted of just one domain have been also detected in mammals. Substantial progress in ACE domain research was achieved during the last years, when their crystal structures were determined. The crystal structures of domains in complex with diverse potent ACE inhibitors provided new insights into structure-based differences of the domain active sites. Physiological functions of ACE are not limited by regulation of the cardiovascular system. Recent evidence suggests that the ACE domains may be also involved into control of different physiological functions. The C-terminal catalytic domain plays an important role in the regulation of blood pressure: it catalyzes angiotensin I cleavage in vivo. The N-domain contributes to the processing of other bioactive peptides for which it exhibits high affinity. The role of the N-domain is not ultimately associated with functioning of the rennin-angiotensin system and it contributes processing of other bioactive peptides for which it exhibits high affinity (goralatide, luliberin, enkephalin heptapeptide, beta-amyloid peptide). Domain-selective inhibitors selectively blocking either the N- or C-domain of ACE have been developed. 相似文献
996.
Chen-Xi Hu Hui Huang Li Zhang You Huang Zhu-Fang Shen Ke-Di Cheng Guan-Hua Du Ping Zhu 《Biotechnology letters》2009,31(7):979-984
Dipeptidyl peptidase (DPP) IV inhibitors provide a new strategy for the treatment of type 2 diabetes. Human DPP-IV gene was
cloned from differentiated Caco-2 cells and expressed in Pichia pastoris. The recombinant enzyme was used in a new system for screening of DPP-IV inhibitors. By high throughput screening, a novel
compound (W5188) was identified from 75,000 compounds with an IC50 of 6.5 μM. This method is highly reproducible and reliable for discovery of DPP-IV inhibitors as shown by Z′ value of 0.73
and S/N ratio of 6.89. 相似文献
997.
Microbial production of 2,3-butanediol from Jerusalem artichoke tubers by <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis> 总被引:1,自引:0,他引:1
Li-Hui Sun Xu-Dong Wang Jian-Ying Dai Zhi-Long Xiu 《Applied microbiology and biotechnology》2009,82(5):847-852
2,3-Butanediol is one of the promising bulk chemicals with wide applications. Its fermentative production has attracted great
interest due to the high end concentration. However, large-scale production of 2,3-butanediol requires low-cost substrate
and efficient fermentation process. In the present study, 2,3-butanediol production by Klebsiella pneumoniae from Jerusalem artichoke tubers was successfully performed, and various technologies, including separate hydrolysis and fermentation
(SHF) and simultaneous saccharification and fermentation (SSF), were investigated. The concentration of target products reached
81.59 and 91.63 g/l, respectively after 40 h in batch and fed-batch SSF processes. Comparing with fed-batch SHF, the fed-batch
SSF provided 30.3% higher concentration and 83.2% higher productivity of target products. The results showed that Jerusalem
artichoke tuber is a favorable substrate for 2,3-butanediol production, and the application of fed-batch SSF for its conversion
can result in a more cost-effective process. 相似文献
998.
Raimondi S Roncaglia L De Lucia M Amaretti A Leonardi A Pagnoni UM Rossi M 《Applied microbiology and biotechnology》2009,81(5):943-950
Twenty-two strains of Bifidobacterium, representative of eight major species of human origin, were screened for their ability to transform the isoflavones daidzin
and daidzein. Most of the strains released the aglycone from daidzin and 12 gave yields higher than 90%. The kinetics of growth,
daidzin consumption, and daidzein production indicated that the hydrolytic activity occurred during the growth. The supernatant
of the majority of the strains did not release the aglycone from daidzin, suggesting that cell-associated β-glucosidases (β-Glu)
are mainly responsible for the metabolism of soybean glyco-conjugates. Cell-associated β-Glu was mainly intracellular and
significantly varied among the species and the strains. The lack of β-Glu was correlated with the inability to hydrolyze daidzin.
Although S-equol production by anaerobic intestinal bacteria has been established, information on S-equol-producing bifidobacteria
is contradictory. In this study, 22 bifidobacteria failed to transform daidzein into reduced metabolites under all the experimental
conditions, excluding any role in the reductive pathway of daidzein toward the production of S-equol. These results suggest
that selected probiotic strains of Bifidobacterium can be used to speed up the release of daidzein, improving its bioavailability for absorption by colonic mucosa and/or biotransformation
to S-equol by other intestinal microorganisms. 相似文献
999.
核苷糖是植物细胞壁多聚糖合成时的活化底物.综述了近年来拟南芥核苷糖转换相关基因的克隆及功能分析等方面的研究进展.使人们能够深入认识核苷糖转换酶在植物生长发育中的重要作用,并且为人工改造植物细胞壁提供了理论依据.然而,对核苷糖转换酶的转录调控和代谢调节等方面研究还有待加强. 相似文献
1000.
Yu. M. Kirillova E. O. Mikhailova N. P. Balaban A. M. Mardanova A. R. Kayumov G. N. Rudenskaya S. V. Kostrov M. R. Sharipova 《Microbiology》2006,75(2):142-147
The effect of certain nutrients on the growth and production of the Bacillus intermedius subtilisin-like serine proteinase by the recombinant strain Bacillus subtilis AJ73(pCS9) was studied. Glucose was found to inhibit the synthesis of proteinase in the early (28 h of growth) but not in the late stationary phase (48 h of growth). The inhibitory effect of the other mono-and disaccharides studied was less pronounced. Casamino acids added to the medium at concentrations of 0.1–1% as an additional carbon and nitrogen source stimulated enzyme biosynthesis. Individual amino acids (cysteine, asparagine, glutamine, tryptophan, histidine, and glutamate) also stimulated enzyme biosynthesis in the early stationary phase by 25–30%, whereas other amino acids (valine, leucine, alanine, and aspartate) were ineffective or even slightly inhibitory to enzyme production. The stimulatory effect of the first group of amino acids on the synthesis of proteinase in the late stationary phase was negligible. In contrast, the bivalent ions Ca2+, Mg2+, and Mn2+ stimulated biosynthesis of proteinase in the late stationary phase (by 20–60%) and not in the early stationary phase. The data indicate that there are differences in the biosyntheses of proteinase by the recombinant B. subtilis strain during the early and late periods of the stationary phases. 相似文献