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991.
Interspecies Transmission of Feline Immunodeficiency Virus from the Domestic Cat to the Tsushima Cat (Felis bengalensis euptilura) in the Wild
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Yoshiaki Nishimura Yuko Goto Kumiko Yoneda Yasuyuki Endo Takuya Mizuno Masaharu Hamachi Hiroyuki Maruyama Hirotoshi Kinoshita Susumu Koga Mitsuru Komori Seigo Fushuku Kanji Ushinohama Masao Akuzawa Toshihiro Watari Atsuhiko Hasegawa Hajime Tsujimoto 《Journal of virology》1999,73(9):7916-7921
Feline immunodeficiency virus (FIV) was isolated from a wild-caught Tsushima cat (Felis bengalensis euptilura), an endangered Japanese nondomestic subspecies of leopard cat (F. bengalensis). Phylogenetic analysis of the env gene sequences indicated that the FIV from the Tsushima cat belonged to a cluster of subtype D FIVs from domestic cats. FIVs from both the Tsushima cat and the domestic cat showed similar levels of replication and cytopathicity in lymphoid cell lines derived from these two species. The results indicated the occurrence of interspecies transmission of FIV from the domestic cat to the Tsushima cat in the wild. 相似文献
992.
Sakuma T Nakamoto T Hemmi H Kitazawa S Kitazawa R Notomi T Hayata T Ezura Y Amagasa T Noda M 《Journal of cellular physiology》2012,227(7):2807-2812
Tumor metastasis to bone is a serious pathological situation that causes severe pain, and deterioration in locomoter function. However, the mechanisms underlying tumor metastasis is still incompletely understood. CIZ/NMP4 is a nucleocytoplasmic shuttling protein and its roles in tumor cells have not been known. We, therefore, hypothesized the role of CIZ/NMP4 in B16 melanoma cells that metastasize to bone. CIZ/NMP4 is expressed in B16 cells. The CIZ/NMP4 expression levels are correlated to the metastatic activity in divergent types of melanoma cells. Overexpression of CIZ/NMP4 increased B16 cell migration in Trans-well assay. Conversely, siRNA-based knockdown of CIZ/NMP4 suppressed migratory activity of these cells. As RANKL promotes metastasis of tumor cells in bone, we tested its effect on CIZ in melanoma cells. RANKL treatment enhanced CIZ/NMP4 expression. This increase of CIZ by RANKL promoted migration. Conversely, we identified CIZ/NMP4 binding site in the promoter of RANKL. Furthermore, luciferase assay indicated that CIZ/NMP4 overexpression enhanced RANKL promoter activities, revealing a positive feedback loop of CIZ/NMP4 and RANKL in melanoma. These observations indicate that CIZ/NMP4 is critical regulator of metastasis of melanoma cells. 相似文献
993.
Yuichi Takiue Makoto Hosoyamada Takuya Yokoo Masaki Kimura Manami Ochiai Kiyoko Kaneko 《Nucleosides, nucleotides & nucleic acids》2013,32(6-7):596-600
Familial juvenile hyperuricemic nephropathy is caused by mutations in the UMOD gene encoding uromodulin. A transgenic mouse model was developed by introducing a human mutant UMOD (C148W) cDNA under control of the mouse umod promoter. Uromodulin accumulation was observed in the thick ascending limb cells in the kidney of transgenic mice. However, the urinary excretion of uromodulin in transgenic mice did not decrease and LC-MS/MS analysis indicated it was of mouse origin. Moreover, the creatinine clearance was not different between wildtype and transgenic animals. Consequently, the onset of the disease was not observed in transgenic mice until 24 weeks of age. 相似文献
994.
Cultured Cortical Neurons Can Perform Blind Source Separation According to the Free-Energy Principle
Blind source separation is the computation underlying the cocktail party effect––a partygoer can distinguish a particular talker’s voice from the ambient noise. Early studies indicated that the brain might use blind source separation as a signal processing strategy for sensory perception and numerous mathematical models have been proposed; however, it remains unclear how the neural networks extract particular sources from a complex mixture of inputs. We discovered that neurons in cultures of dissociated rat cortical cells could learn to represent particular sources while filtering out other signals. Specifically, the distinct classes of neurons in the culture learned to respond to the distinct sources after repeating training stimulation. Moreover, the neural network structures changed to reduce free energy, as predicted by the free-energy principle, a candidate unified theory of learning and memory, and by Jaynes’ principle of maximum entropy. This implicit learning can only be explained by some form of Hebbian plasticity. These results are the first in vitro (as opposed to in silico) demonstration of neural networks performing blind source separation, and the first formal demonstration of neuronal self-organization under the free energy principle. 相似文献
995.
Rie Terada Takuya Nakayama Masaki Iwabuchi Ko Shimamoto 《The Plant journal : for cell and molecular biology》1993,3(2):241-252
To investigate developmental regulation of wheat histone H3 gene expression, the H3 promoter, which has its upstream sequence to ?1711 (relative to the cap site as +1), was fused to the coding region of the gus A gene (?1711H3/GUS) and introduced into a monocot plant, rice. Detailed histochemical analysis revealed two distinct types of GUS expression in transgenic rice plants; one is cell division-dependent found in the apical meristem of shoots and roots and in young leaves, and another is cell division-independent detected in flower tissues including the anther wall and the pistil. In this study, replication-dependent expression occurring in non-dividing cells which undergo endoreduplication could not be discriminated from strict replication-independent expression. The observed expression pattern in different parts of roots suggested that the level of the H3/GUS gene expression is well correlated with activity of cell division in roots. To identify 5′ sequences of the H3 promoter necessary for an accurate regulation of the GUS expression, two constructs containing truncated promoters, ?908H3/GUS and ?185H3/GUS, were analyzed in transiently expressed protoplasts, stably transformed calli and transgenic plants. The results indicated that the region from ?909 to ?1711 contains the positive cis-acting element(s) and that the proximal promoter region (up to ?185) containing the conserved hexamer, octamer and nonamer motifs is sufficient to direct both cell division-dependent and -independent expression. The use of the meristem of roots regenerated from transformed calli for the analysis of cell division-dependent expression of plant genes is discussed. 相似文献
996.
Taiki Umezawa Takeshi Maeda Takuya Akiyama Nurcahyo Iman Prakoso Jakia Jerin Mehjabin Tatsufumi Okino Fuyuhiko Matsuda 《化学与生物多样性》2023,20(6):e202300400
Synthesis of three derivatives of danicalipin A, tetrachloride, trisulfate and a fluorescent probe was achieved through Wittig reaction strategy. Toxicity of the derivatives against brine shrimp (Artemia salina) as also investigated to provide useful information for the biological activity; i) less chloride derivative showed similar toxicity to danicalipin A, ii) the amphiphilic property, a characteristic feature of danicalipin A, was crucial because trisulfate considerably decreased the toxicity and iii) fluorescent derivative kept brine shrimp toxicity of danicalipin A. 相似文献
997.
Sugahara Kazuhiro Kiyota Taketoshi Clark Richard A. F. Mason Robert J. 《Virchows Archiv. B, Cell pathology including molecular pathology》1993,63(1):115-121
Virchows Archiv B Cell Pathology - The cytoskeleton of alveolar type II cells on different matrices has been examined, and the bioelectric properties of these cells grown as monolayers in primary... 相似文献
998.
The discovery of non-universal genetic codes in several mitochondria and nuclear systems during the past ten years has necessitated a reconsideration of the concept that the genetic code is universal and frozen, as was once believed. Here, the flexibility of the relationship between codons and amino acids is discussed on the basis of the distribution of non-universal genetic codes in various organisms insofar as has been observed to date. Judging from the result of recent investigations into tRNA identity, it would appear that the non-participation of the anticodon in recognition by aminoacyl-tRNA synthetase has significantly influenced the variability of codons. 相似文献
999.
Atsuko Sugimoto Tetsushi Inoue Ichiro Tayasu Leigh Miller Satoki Takeichi Takuya Abe 《Ecological Research》1998,13(2):241-257
Methane and hydrogen emission rates and the 13C of CH4 were observed for various termites in Australia, Thailand and Japan. Combined with the already reported emission rates of CH4 in the literature, the phylogenetic trend was examined. Emission rates of the observed termites were categorized into five groups: group I with high CH4 and low H2 emission rates with a CH4/H2 ratio of typically 10/1; group II with high CH4 and high H2 emissions with a CH4/H2 ratio of 4/1–1/2; group III with low emission rates of CH4 and H2; group IV with high H2 and insignificant CH4 emissions; and group V with insignificant emissions for both CH4 and H2. In lower termites, there are both colonies infected and uninfected with methanogens even in the same species, and no specific trend in CH4 and H2 emissions was observed within a genus. Whether protozoa in the hindgut of termites are infected with methanogens or not and the differences in species compositions of protozoa are possibly responsible for the inter-colonial variations. The proportions of infected colonies were possibly small for the family Kalotermitidae (dry wood feeders), and relatively large for families of wet or damp wood feeders. The hydrogen emission rate possibly depends on the locality of methanogens: namely, whether they are intracellular symbionts of protozoa or whether they are attached to the hindgut wall. Emission rates of higher termites were classified into groups according to genera and the diet. Most species of soil or wood/soil interface feeders classified into group I, while the soil feeders Dicuspiditermes in Thailand and Amitermes in Australia were classified into groups with high H2 emission rates. Typical wood-feeding termites and fungus-growing termites were classified into group III. The results indicate that higher termites tend to increase the CH4 emission rate during dietary evolution from wood- to soil-feeding, and two types of the system with different efficiencies of interspecies transfer of H2 have been formed. The 13C of CH4 was discernible with a difference in the decomposition process in the termite–symbiont system among lower termites, fungus-growing termites and other higher termites. 相似文献
1000.
E. Kimura Takuya Ikeda Shin Aoki Mitsuhiko Shionoya 《Journal of biological inorganic chemistry》1998,3(3):259-267
As an extension of our earlier discoveries that ZnII-cyclen complex (1) (cyclen=1,4,7,10-tetraazacyclododecane) and ZnII-acridine-pendant cyclen complex ZnII-N-(9-acridin)ylmethyl-cyclen (3) are the first compounds to selectively recognize thymidine and uridine nucleosides in aqueous solution at physiological
pH, the interaction of these and a relevant complex, bis(ZnII-cyclen) (7), has been investigated with a series of polynucleotides, single-stranded poly(U) and poly(G), and double-stranded poly(A)·poly(U),
poly(dA)·poly(dT) and poly(dG)·poly(dC). These ZnII-cyclen complexes interact with the imide-containing nucleobases in the single-stranded poly(U), unperturbed by the presence
of the anionic phosphodiester backbone. The affinity constant of 1 for each N(3)-deprotonated uracil base in poly(U) is determined to be log K= 5.1 by a kinetic measurement, which is almost the same as log K=5.2 for the interaction of 1 with uridine. Thus, they disrupt the A-U (or A-T) hydrogen bonds to unzip the duplex of poly(A)·poly(U) or poly(dA)·poly(dT),
as demonstrated by lowering of the melting temperatures (T
m) of poly(A)·poly(U) and poly(dA)·poly(dT) in 5 mM Tris-HCl buffer (pH 7.6, 10 mM NaCl) with increase in their concentrations.
The order of the denaturing efficiency is well correlated with that of the 1 : 1 affinity constants for each complex with
uracil or thymine;7>3>1. The comparison of circular dichroism (CD) spectra for poly(A)·poly(U), poly(A), and poly(U) in the presence of 3 has revealed a structural change from poly(A)·poly(U) to two single strands, poly(A) and poly(U), caused by 3 binding exclusively to uracils in poly(U). On the other hand, the acridine-pendant cyclen complex 3, which earlier was found to associate with guanine by the ZnII coordinating with guanine N(7), in addition to the π-π stacking, interacts with guanine in the double helix of poly(dG)·poly(dC)
from outside and stabilized the double-stranded structure, as indicated by higher T
m.
Received: 31 December 1997 / Accepted: 23 February 1998 相似文献