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991.
Nur-E-Kamal A Ahmed I Kamal J Babu AN Schindler M Meiners S 《Molecular and cellular biochemistry》2008,309(1-2):157-166
Activation of fibroblast growth factor receptors (FGFRs) requires the formation of a ternary complex between fibroblast growth
factors (FGFs), FGFRs, and heparan sulfate proteoglycans, which are all located on the cell surface and the basement membrane
(BM)/extracellular matrix (ECM). Heparan sulfate proteoglycans appear to stabilize FGFs by inhibiting the rapid degradation
of FGFs normally observed in solution. Because of the pivotal role of FGFs in proliferative and developmental pathways, a
number of recent studies have attempted to engineer microenvironments to stabilize growth factors for use in applications
in tissue culture and regenerative medicine. In this communication, we demonstrate that covalent linkage of FGF-2 to nanofibrillar
surfaces (defined as covalently bound FGF-2) composed of a network of polyamide nanofibers resulted in the maintenance of
the biological efficacy of FGF-2 when stored dry for at least 6 months at 25°C or 4°C. Moreover, covalently bound FGF-2 was
more potent than FGF-2 in solution when measured in cellular assays of proliferation and viability using a variety of cell
types. Covalently bound FGF-2 also strongly activated FGFR, extracellular signal-regulated kinase (ERK1/2), and c-fos. Hence
cell-signaling molecules can be incorporated into a synthetic nanofibrillar surface, providing a novel means to enhance their
stability and biological activity. 相似文献
992.
Understanding regulatory mechanisms of protein synthesis in eukaryotes is essential for the accurate annotation of genome sequences. Kozak reported that the nucleotide sequence GCCGCC(A/G)CCAUGG (AUG is the initiation codon) was frequently observed in vertebrate genes and that this 'consensus' sequence enhanced translation initiation. However, later studies using invertebrate, fungal and plant genes reported different 'consensus' sequences. In this study, we conducted extensive comparative analyses of nucleotide sequences around the initiation codon by using genomic data from 47 eukaryote species including animals, fungi, plants and protists. The analyses revealed that preferred nucleotide sequences are quite diverse among different species, but differences between patterns of nucleotide bias roughly reflect the evolutionary relationships of the species. We also found strong biases of A/G at position -3, A/C at position -2 and C at position +5 that were commonly observed in all species examined. Genes with higher expression levels showed stronger signals, suggesting that these nucleotides are responsible for the regulation of translation initiation. The diversity of preferred nucleotide sequences around the initiation codon might be explained by differences in relative contributions from two distinct patterns, GCCGCCAUG and AAAAAAAUG, which implies the presence of multiple molecular mechanisms for controlling translation initiation. 相似文献
993.
Kuroki H Nakagawa Y Mori K Kobayashi M Yasura K Okamoto Y Suzuki T Nishitani K Nakamura T 《Arthritis research & therapy》2008,10(4):R78
Introduction
There is a lack of data relating the macroscopic appearance of cartilage to its ultrasound properties. The purpose of the present study was to evaluate degenerated cartilage and healthy-looking cartilage using an ultrasound system. 相似文献994.
995.
P450 in wild animals as a biomarker of environmental impact 总被引:1,自引:0,他引:1
Shoichi Fujita Issei Chiba Mayumi Ishizuka Hidenobu Hoshi Hisato Iwata Akihito Sakakibara Shinsuke Tanabe Akio Kazusaka Makihiko Masuda Yasushi Masuda Hajime Nakagawa 《Biomarkers》2001,6(1):19-25
The impact of environmental pollution on selected animals was tested by monitoring the hepatic content of cytochromes P450 and their enzyme activities or by calculating TEQ values from the concentration of pollutants in the body. Fish-eating Stellars Sea Eagles, Haliaeetus pelagicus, found dead in the northern part of Hokkaido island accumulated high levels of PCBs and DDT and metabolites. The TEQ values calculated from the PCB concentration in the eagles were high enough to cause a significant toxic effect in other birds living in the same environment. Some of these birds were also contaminated with high concentrations of lead. Spotted seals, Phoca largha, captured along the coast-line of Hokkaido accumulated PCBs in their fat at about 100 million times the concentrations in the surface sea water. The levels of expressions of hepatic microsomal CYP 1A1and related enzyme activities in these seals showed good correlation to the levels of PCBs accumulated in the fat. The fresh water crabs, Eriocheir japonicus, were captured from three different rivers with various degrees of pollution. The P450 content and the related enzyme activities showed good correlation to TEQ values obtained from the concentrations of PCBs and PCDDs in the crabs from the rivers. The wild rodents, Clethrionomys rufocanus, were captured from urban, agricultural, and forest areas in Hokkaido. Those from the forest area had the lowest CYP content and related enzyme activities, comparable to those in laboratory-raised animals. Those from the urban areas, presumably contaminated with PAHs from fuel combustion, showed increased CYP 1A1 content and related enzyme activities. Those from the agricultural areas showed increased levels of CYP 1A1, 2B, 2E1. Rats treated with some of the agrochemicals used in the area resulted in a similar pattern of induction. It is concluded that P450 can be a useful biomarker for assessing the environmental impact of chemical pollutants on wild animals. 相似文献
996.
Ueda Keiichi Nakamura Ichiro Itano Eiko Nakagawa Takemura Kazunori Nakazato Yasutomo Sano Ayako 《Mycopathologia》2017,182(9-10):937-946
Mycopathologia - “Paracoccidioidomycosis ceti” is a rare zoonotic fungal infection affecting dolphins and is endemic worldwide. The causative agents are Paracoccidioides species;... 相似文献
997.
Monira Pervin Keiko Unno Aimi Nakagawa Yuu Takahashi Kazuaki Iguchi Hiroyuki Yamamoto Minoru Hoshino Aya Hara Akiko Takagaki Fumio Nanjo Akira Minami Shinjiro Imai Yoriyuki Nakamura 《Biochemistry and Biophysics Reports》2017
BackgroundThe consumption of green tea catechins (GTCs) suppresses age-related cognitive dysfunction in mice. GTCs are composed of several catechins, of which epigallocatechin gallate (EGCG) is the most abundant, followed by epigallocatechin (EGC). Orally ingested EGCG is hydrolyzed by intestinal biota to EGC and gallic acid (GA). To understand the mechanism of action of GTCs on the brain, their permeability of the blood brain barrier (BBB) as well as their effects on cognitive function in mice and on nerve cell proliferation in vitro were examined.MethodsThe BBB permeability of EGCG, EGC and GA was examined using a BBB model kit. SAMP10, a mouse model of brain senescence, was used to test cognitive function in vivo. Human neuroblastoma SH-SY5Y cells were used to test nerve cell proliferation and differentiation.ResultsThe in vitro BBB permeability (%, in 30 min) of EGCG, EGC and GA was 2.8±0.1, 3.4±0.3 and 6.5±0.6, respectively. The permeability of EGCG into the BBB indicates that EGCG reached the brain parenchyma even at a very low concentration. The learning ability of SAMP10 mice that ingested EGCG (20 mg/kg) was significantly higher than of mice that ingested EGC or GA. However, combined ingestion of EGC and GA showed a significant improvement comparable to EGCG. SH-SY5Y cell growth was significantly enhanced by 0.05 µM EGCG, but this effect was reduced at higher concentrations. The effect of EGC and GA was lower than that of EGCG at 0.05 µM. Co-administration of EGC and GA increased neurite length more than EGC or GA alone.ConclusionCognitive dysfunction in mice is suppressed after ingesting GTCs when a low concentration of EGCG is incorporated into the brain parenchyma via the BBB. Nerve cell proliferation/differentiation was enhanced by a low concentration of EGCG. Furthermore, the additive effect of EGC and GA suggests that EGCG sustains a preventive effect after the hydrolysis to EGC and GA. 相似文献
998.
Ryousuke Nagata Yoshihiro Takaki Akihiro Tame Takuro Nunoura Hisashi Muto Sayaka Mino Shigeki Sawayama Ken Takai Satoshi Nakagawa 《Systematic and applied microbiology》2017,40(6):352-356
A moderately thermophilic, strictly anaerobic, chemoautotrophic bacterium, designated strain HS1857T, was isolated from a deep-sea hydrothermal vent at the Noho site in the Mid-Okinawa Trough. Strain HS1857T grew between 35 and 63 °C (optimum 55 °C), in the presence of 10–55 g l?1 NaCl (optimum 25 g l?1), and pH 5.5–7.1 (optimum 6.4). Growth occurred with molecular hydrogen as the electron donor and elemental sulfur, nitrate, or selenate as the electron acceptors. Formate could serve as an alternative electron donor with nitrate as an electron acceptor. During growth with nitrate as the electron acceptor, strain HS1857T produced ammonium and formed a biofilm. CO2 was utilized as the sole carbon source. The G + C content of the genomic DNA was 33.2 mol%. Phylogenetic analysis of the 16S rRNA gene sequence indicated that strain HS1857T is a member of the order Nautiliales, showing a sequence similarity of 95.0% with Lebetimonas acidiphila Pd55T. The fatty acid composition was similar to that of L. acidiphila, which was dominated by C18:0 (47.0%) and C18:1 (23.7%). Based on the genomic, chemotaxonomic, phenotypic characteristics, the name Lebetimonas natsushimae sp. nov., is proposed. The type strain is HS1857T (= NBRC 112478T = DSM 104102T). 相似文献
999.
Winter territory prospecting is associated with life‐history stage but not activity in a passerine 下载免费PDF全文
Alfredo Sánchez‐Tójar Isabel Winney Antje Girndt Mirre J. P. Simons Shinichi Nakagawa Terry Burke Julia Schroeder 《Journal of avian biology》2017,48(3):407-416
Finding a high quality territory is essential for many animals to reproduce successfully. Despite its importance for fitness, we know little about the process of territory prospecting in wild birds, and whether individual traits and behaviours, such as personality, co‐vary with territory prospecting. Here, we use long‐term data from a wild, insular house sparrow Passer domesticus population to test three hypotheses about territory fidelity and prospecting: 1) house sparrows show high territory fidelity between years and also during winter. 2) Individuals will prospect for a breeding territory during their first winter whereas older, more experienced individuals will keep a territory from previous years and will, therefore, show no or reduced winter territory prospecting. 3) More active behavioural types will prospect more than less active behavioural types. We use data from four winters from automatically, daily recorded nest‐box visits of 188 birds of known age. The number of nest‐boxes that each individual visited within each winter was used as a proxy of winter territory prospecting. We show that house sparrows visit multiple nest‐boxes during their first winter, whereas older individuals keep territories year‐round and, potentially because of this, indeed show reduced winter territory prospecting. Activity was not associated with the number of nest‐boxes visited. Further research is needed to investigate whether time of territory and mate acquisition differs among individuals and the possible effect on lifetime fitness. 相似文献
1000.
Erina Kitagawa Tatsuya Yamamoto Mayuko Fujishita Yuki Ota Kohei Yamamoto Tomoyuki Nakagawa 《Bioscience, biotechnology, and biochemistry》2017,81(2):316-322
We investigated the efficacy of supplementing the diet with choline or betaine in ameliorating lipid accumulation induced by vitamin B6 (B6) deficiency in rat liver. Male Wistar rats were fed a control, B6-deficient, choline-supplemented (2, 4, or 6 g choline bitartrate/kg diet) B6-deficient diet or betaine-supplemented (1, 2, or 4 g betaine anhydrous/kg diet) B6-deficient diet for 35 d; all diets contained 9 g L-methionine (Met)/kg diet. Choline or betaine supplementation attenuated liver lipid deposition and restored plasma lipid profiles to control levels. These treatments restored the disruptions in Met metabolism and the phosphatidylcholine (PC)/phosphatidylethanolamine (PE) ratio induced by B6 deficiency in liver microsomes. These results suggest that choline and betaine ameliorated liver lipid accumulation induced by B6 deficiency via recovery of Met metabolism and very low-density lipoprotein secretion by restoring the supply of PC derived from PE. 相似文献