排序方式: 共有59条查询结果,搜索用时 15 毫秒
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Koshida S Shinya M Nikaido M Ueno N Schulte-Merker S Kuroiwa A Takeda H 《Developmental biology》2002,244(1):9-20
The expression patterns of region-specific neuroectodermal genes and fate-map analyses in zebrafish gastrulae suggest that posterior neural development is initiated by nonaxial signals, distinct from organizer-derived secreted bone morphogenetic protein (BMP) antagonists. This notion is further supported by the misexpression of a constitutively active form of zebrafish BMP type IA receptor (CA-BRIA) in the zebrafish embryos. It effectively suppressed the anterior neural marker, otx2, but not the posterior marker, hoxb1b. Furthermore, we demonstrated that the cells in the presumptive posterior neural region lose their neural fate only when CA-BRIA and Xenopus dominant-negative fibroblast growth factor (FGF) receptors (XFD) are coexpressed. The indications are that FGF signaling is involved in the formation of the posterior neural region, counteracting the BMP signaling pathway within the target cells. We then examined the functions of Fgf3 in posterior neural development. Zebrafish fgf3 is expressed in the correct place (dorsolateral margin) and at the correct time (late blastula to early gastrula stages), the same point that the most precocious posterior neural marker, hoxb1b, is first activated. Unlike other members of the FGF family, Fgf3 had little mesoderm-inducing activity. When ectopically expressed, Fgf3 expands the neural region with suppression of anterior neural fate. However, this effect was mediated by Chordino (zebrafish Chordin), because Fgf3 induces chordino expression in the epiblast and Fgf3-induced neural expansion was substantially suppressed in dino mutants with mutated chordino genes. The results obtained in the present study reveal multiple actions of the FGF signal on neural development: it antagonizes BMP signaling within posterior neural cells, induces the expression of secreted BMP antagonists, and suppresses anterior neural fate. 相似文献
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Mochizuki R Dateki M Yanai K Ishizuka Y Amizuka N Kawashima H Koga Y Ozawa H Fukamizu A 《Biochemical and biophysical research communications》2003,310(4):1219-1226
Neurochondrin/norbin is a cytoplasmic protein involved in dendrite outgrowth. The expression of the gene has been restricted to neural, bone, and chondral tissues. To identify the functions of the gene in vivo, we have generated mice with a disrupted mutation in the neurochondrin/norbin gene. Histological analysis of heterozygous mutant mice indicates the possibility of specific functions of neurochondrin/norbin in chondrocyte differentiation. We defined the expression patterns of neurochondrin/norbin-lacZ fusion protein in the central nervous system. In the developing olfactory bulb, beta-galactosidase activity was detected in the mantle layer at 12.5 dpc and the strongest activity was detected in the presumptive mitral or tufted cell layer at 15.5 dpc. beta-Galactosidase activity was also detected in the lateral choroid plexus. In homozygous (-/-) mutant mice, the disruption of the neurochondrin/norbin gene leads to early embryonic death between 3.5 and 6.5 dpc. This result indicates that neurochondrin/norbin gene function is essential for the early embryogenesis. 相似文献
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Hiroshi Nakano Yoko Shibata Sumito Inoue Akira Igarashi Keiko Yamauchi Shuichi Abe Masamichi Sato Yasuko Aida Keiko Nunomiya Tomomi Kimura Takako Nemoto Tetsu Watanabe Tsuneo Konta Yoshiyuki Ueno Takeo Kato Takamasa Kayama Isao Kubota 《PloS one》2013,8(12)
Background
Accumulating evidence suggests the involvement of an autoimmune mechanism in the pathogenesis of respiratory dysfunction. The aim of this study was to investigate the relationship between pulmonary function and serum antibodies to several connective tissue disease autoantigens (ACTDA) levels, which has not been investigated in a general population.Methods
Blood sampling and spirometry were performed for subjects (n = 3,257) aged ≥40 years who participated in a community-based annual health check in Takahata, Japan, from 2004 to 2006. ACTDA was measured by enzyme immunoassay, and subjects with ACTDA values ≥20 were defined as positive.Results
In males, there were significant inverse relationships between logarithmically transformed ACTDA values and spirometric parameters, including % predicted values for forced expiratory volume in 1 s (FEV1) and maximal midexpiratory flow (MMF) as well as FEV1/forced vital capacity (FVC). Multiple linear regression analysis revealed that except for the relationship between ACTDA and FEV1/FVC, these relationships were still significant after adjustment for Brinkman index (a measure of inhaled cigarette consumption). The prevalence of positive ACTDA was greater in male never-smokers with mixed ventilation disorders and relatively severe airflow obstruction (% predicted FEV1 below the median value).Conclusions
Autoimmunity may be involved in the mechanism of impaired pulmonary function in the general population. 相似文献37.
Hiroyuki Tamiya Hideo Yasunaga Hiroki Matusi Kiyohide Fushimi Sumito Ogawa Masahiro Akishita 《PloS one》2015,10(6)
Background
Preventing falls and bone fractures in hospital care is an important issue in geriatric medicine. Use of hypnotics is a potential risk factor for falls and bone fractures in older patients. However, data are lacking on the association between use of hypnotics and the occurrence of bone fracture.Methods
We used a national inpatient database including 1,057 hospitals in Japan and included dementia patients aged 50 years or older who were hospitalized during a period of 12 months between April 2012 and March 2013. The primary outcome was the occurrence of bone fracture during hospitalization. Use of hypnotics was compared between patients with and without bone fracture in this matched case-control study.Results
Of 140,494 patients, 830 patients suffered from in-hospital fracture. A 1:4 matching with age, sex and hospital created 817 cases with fracture and 3,158 matched patients without fracture. With adjustment for the Charlson comorbidity index, emergent admission, activities of daily living, and scores for level walking, a higher occurrence of fractures were seen with short-acting benzodiazepine hypnotics (odds ratio, 1.43; 95% confidence interval, 1.19–1.73; P<0.001), ultrashort-acting non-benzodiazepine hypnotics (1.66; 1.37–2.01; P<0.001), hydroxyzine (1.45; 1.15–1.82, P=0.001), risperidone and perospirone (1.37; 1.08–1.73; P=0.010). Other drug groups were not significantly associated with the occurrence of in-hospital fracture.Conclusions
Short-acting benzodiazepine hypnotics and ultrashort-acting non-benzodiazepine hypnotics may increase risk of bone fracture in hospitalized dementia patients. 相似文献38.
Azithromycin suppresses interleukin-12p40 expression in lipopolysaccharide and interferon-γ stimulated macrophages
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Nakasono S Ikehata M Dateki M Yoshie S Shigemitsu T Negishi T 《Mutation research》2008,649(1-2):187-200
We used bacterial mutation and yeast genotoxicity tests to evaluate the effects of intermediate frequency (IF; 2 kHz, 20 kHz and 60 kHz) magnetic fields (MFs) on mutagenicity, co-mutagenicity and gene conversion. We constructed a Helmholtz type exposure system that generated vertical and sinusoidal IF MFs, such as 0.91 mT at 2 kHz, 1.1 mT at 20 kHz and 0.11 mT at 60 kHz. Mutagenicity, co-mutagenicity and gene conversion assays were performed for each of the three MF exposure conditions. Mutagenicity testing was performed in four strains of Salmonella typhimurium (TA98, TA100, TA1535 and TA1537) and two strains of Escherichia coli (WP2 uvrA and WP2 uvrA/pKM101) to cover a wide spectrum of point mutations. For co-mutagenicity tests, we used four sensitive test strains (TA98, TA100, WP2 uvrA and WP2 uvrA/pKM101) with five chemical mutagens (t-butyl hydroperoxide (BH, a hydroxyl free radical precursor), 2-(2-furyl)-3-(5-nitro-2-furyl) acrylamide (AF2) and N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG, DNA reactive reagents), benz[a]pyrene (BaP) and 2-aminoanthracene (2AA, DNA reactive promutagens). Gene conversion testing was performed in the yeast test strain, Saccharomyces cerevisiae XD83. We also examined the effects on the repair process of DNA damage by UV irradiation. No statistically significant effects were observed between exposed and control groups in any of the genotoxicity tests, indicating that the IF MFs (0.91 mT at 2 kHz, 1.1 mT at 20 kHz or 0.11 mT at 60 kHz) do not have mutagenic or co-mutagenic potentials for the chemical mutagens tested under these experimental conditions. Our findings also indicate that these IF MFs do not induce gene conversion or affect the repair process of DNA damage in eukaryotic cells. 相似文献