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101.
Itoh Y Masuyama N Nakayama K Nakayama KI Gotoh Y 《The Journal of biological chemistry》2007,282(1):390-396
Neuronal precursors remain in the proliferative zone of the developing mammalian neocortex until after they have undergone neuronal differentiation and cell cycle arrest. The newborn neurons then migrate away from the proliferative zone and enter the cortical plate. The molecules that coordinate migration with neuronal differentiation have been unclear. We have proposed in this study that the cdk inhibitors p57 and p27 play a role in this coordination. We have found that p57 and p27 mRNA increase upon neuronal differentiation of neocortical neuroepithelial cells. Knockdown of p57 by RNA interference resulted in a significant delay in the migration of neurons that entered the cortical plate but did not affect neuronal differentiation. Knockdown of p27 also inhibits neuronal migration in the intermediate zone as well as in the cortical plate, as reported by others. We have also found that knockdown of p27 increases p57 mRNA levels. These results suggest that both p57 and p27 play essential roles in neuronal migration and may, in concert, coordinate the timing of neuronal differentiation, migration, and possibly cell cycle arrest in neocortical development. 相似文献
102.
Annual medical examinations were conducted during adolescence for the in utero clinical study sample subjects exposed prenatally to the atomic bombs in Hiroshima and Nagasaki. Systolic blood pressure and several anthropometric measurements were recorded during these examinations. For 1014 persons exposed in utero, two types of longitudinal analyses were performed, for a total of 7029 observations (6.93 observations per subject) of systolic blood pressure (continuous data) and systolic hypertension (binary data) for persons aged 9 to 19 years. Body mass index (BMI) and/or body weight were considered in the analyses as potential confounders. For the measurements of systolic blood pressure, the common dose effect was 2.09 mmHg per Gy and was significant (P = 0.017). The dose by trimester interaction was suggestive (P = 0.060). A significant radiation dose effect was found in the second trimester (P = 0.001), with an estimated 4.17 mmHg per Gy, but in the first and third trimesters, radiation dose effects were not significant (P > 0.50). For prevalence of systolic hypertension, the radiation dose effect was significant (P = 0.009); the odds ratio at 1 Gy was 2.23 [95% confidence interval (CI): 1.23, 4.04], and the dose by trimester interaction was not significant (P = 0.778). The dose response of systolic hypertension had no dose threshold, with a threshold point estimate of 0 Gy (95% CI: <0.0, 1.1 Gy). The dose response for systolic blood pressure was most pronounced in the second trimester, the most active organogenesis period for the organs relevant to blood pressure. 相似文献
103.
Ohtani T Ohta M Yamamoto K Mano T Sakata Y Nishio M Takeda Y Yoshida J Miwa T Okamoto M Masuyama T Nonaka Y Hori M 《American journal of physiology. Regulatory, integrative and comparative physiology》2007,292(2):R946-R954
Cardiac aldosterone levels have not been evaluated in diastolic heart failure (DHF), and its roles in this type of heart failure remain unclear. This study aimed to detect cardiac aldosterone by use of a liquid chromatographic-mass spectrometric method and to assess the effects of mineralocorticoid receptor blockade on hypertensive DHF. Dahl salt-sensitive rats fed 8% NaCl diet from 7 wk (hypertensive DHF model) were divided at 13 wk into three groups: those treated with subdepressor doses of eplerenone (12.5 or 40 mg x kg(-1) x day(-1)) and an untreated group. Dahl salt-sensitive rats fed 0.3% NaCl diet served as controls. Cardiac aldosterone was detected in the DHF rats but not in the control rats, with increased ventricular levels of mineralocorticoid receptor. Cardiac levels of 11-deoxycorticosterone, corticosterone, and 11-dehydrocorticosterone were not different between the control and DHF rats, but the tissue level of corticosterone that has an affinity to mineralocorticoid receptor was 1,000 times as high as that of aldosterone. Aldosterone synthase activity and CYP11B2 mRNA were undetectable in the ventricular tissue of the DHF rats. Administration of eplerenone attenuated ventricular hypertrophy, ventricular fibrosis, myocardial stiffening, and relaxation abnormality, leading to the prevention of overt DHF. In summary, the myocardial aldosterone level increased in the DHF rats. However, its value was extremely low compared with corticosterone, and no evidence for enhancement of intrinsic myocardial aldosterone production was found. The upregulation of mineralocorticoid receptor may play a central role in the pathogenesis of DHF, and blockade of mineralocorticoid receptor is likely an effective therapeutic regimen of DHF. 相似文献
104.
Osawa M Kenmotsu S Masuyama T Taniguchi K Uchida T Saito C Ohshima H 《Cell and tissue research》2007,330(1):97-109
Our previous findings have demonstrated that the rat autosomal-recessive mutation, whitish chalk-like teeth (wct), induces enamel defects resembling those of human amelogenesis imperfecta (AI) in continuously growing incisor teeth. The
present study clarifies the effect of the wct mutation on the morphogenesis and calcification of rat molar teeth. Formalin-fixed maxillae obtained from animals aged 4-30 days
were examined by electron probe micro-analysis (EPMA) and by immunocytochemistry for amelogenin, ameloblastin, and enamelin.
There were no distinct differences in the calcium and phosphorous contents and the amount of enamel between homozygous mutant
and wild-type teeth during postnatal days 4–11. Although the mineral density in the enamel matrix considerably increased in
the wild-type teeth until day 15, no changes occurred in mutant teeth during days 11–30. The immunoreactivity for enamel proteins
in the secretory-stage ameloblasts in mutant teeth was similar to that in the wild-type teeth, and subsequently mutant maturation-stage
ameloblasts became detached from the enamel surface, resulting in odontogenic cyst formation between the enamel organ and
matrix until day 7 and the expansion of the cyst around the whole tooth crown on day 15. On day 30, the erupted mutant teeth
presented morphological changes such as enamel destruction and tertiary dentin formation in addition to low mineral density
in the enamel. Thus, the wct mutation prevents mineral transport without disturbing the synthesis of enamel proteins in molar teeth because of the absence
of maturation-stage ameloblasts, in addition to the occurrence of odontogenic cysts.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
This work was supported in part by KAKENHI (B) (no. 16390523 to H.O.) and KAKENHI (C) (no. 18592002 to T.U.) from MEXT, Japan. 相似文献
105.
Igarashi Y Trujillo ME Martínez-Molina E Yanase S Miyanaga S Obata T Sakurai H Saiki I Fujita T Furumai T 《Bioorganic & medicinal chemistry letters》2007,17(13):3702-3705
Two novel anthraquinones, lupinacidins A (1) and B (2), have been isolated from the culture broth of a new endophytic actinomycete belonging to the genus Micromonospora. Lupinacidins were found to show significant inhibitory effects on the invasion of murine colon 26-L5 carcinoma cells without inhibiting cell growth. 相似文献
106.
Methyl 4,6-O-benzylidene-2-C- and 3-C-cyano-2,3-dideoxy-D-erythro-hex-2-enopyranosides and -2-enitols were prepared and their epoxidation was performed. 相似文献
107.
Yoshihara R Aoyama E Kadota Y Kawai S Goto T Zhong M Gohda E 《Cellular immunology》2007,250(1-2):14-23
A two-step culture system was used to investigate the role of chondroitin sulfate (CS) B, which is mitogenic to B cells, in differentiation of B cells. Mouse spleen B cells were incubated for 3 days with CSB in the presence of interleukin (IL)-4 and IL-5. After washing, the cells were replated at 10(5) viable cells/well and recultured without CSB in the presence of IL-4 and IL-5. CSB dose-dependently increased IgM production, the greatest enhancement being 450%. Dextran sulfate had a similar effect, whereas other glycosaminoglycans, CSA, CSC, heparin and hyaluronic acid, were marginally effective. Treatment of B cells with CSB resulted in increases in the number of IgM-secreting cells and numbers of CD138-positive cells and CD45R/B220-negative cells. CSB-induced IgM production was inhibited by the protein kinase C (PKC) inhibitor GF109203X but not by the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin. These results demonstrated that CSB promoted differentiation of B cells in the presence of IL-4 and IL-5 and suggested that PKC but not PI3K is crucial for CSB-induced IgM production. 相似文献
108.
Hitoki Yamanaka Toshikazu Takagi Makiko Ohsawa Naoto Yamamoto Noriaki Kubo Takahira Takemoto Shoko Sasano Ritsuko Masuyama Kazutaka Ohsawa 《Experimental Animals》2014,63(3):297-304
To determine the prevalence of drug resistant bacteria colonizing laboratory mice, we
isolated and characterized vancomycin-resistant Enterococcus species
(VRE) from commercially available mice. A total of 24 VRE isolates were obtained from 19
of 21 mouse strains supplied by 4 commercial breeding companies. Of these, 19 isolates of
E. gallinarum and 5 isolates of E. casseliflavus
possessing the vanC1 and vanC2/3 genes intrinsically,
exhibited intermediate resistance to vancomycin respectively. In addition, these isolates
also exhibited diverse resistant patterns to erythromycin, tetracycline, and
ciprofloxacin, whereas the use of antibiotics had not been undertaken in mouse strains
tested in this study. Although 6 virulence-associated genes (ace,
asa, cylA, efaA,
esp, and gelE) and secretion of gelatinase and hemolysin
were not detected in all isolates, 23 of 24 isolates including the isolates of E.
casselifalvus secreted ATP into culture supernatants. Since secretion of ATP by
bacteria resident in the intestinal tract modulates the local immune responses, the
prevalence of ATP-secreting VRE in mice therefore needs to be considered in animal
experiments that alter the gut microflora by use of antibiotics. 相似文献
109.
Myosho T Otake H Masuyama H Matsuda M Kuroki Y Fujiyama A Naruse K Hamaguchi S Sakaizumi M 《Genetics》2012,191(1):163-170
Three sex-determining (SD) genes, SRY (mammals), Dmy (medaka), and DM-W (Xenopus laevis), have been identified to date in vertebrates. However, how and why a new sex-determining gene appears remains unknown, as do the switching mechanisms of the master sex-determining gene. Here, we used positional cloning to search for the sex-determining gene in Oryzias luzonensis and found that GsdfY (gonadal soma derived growth factor on the Y chromosome) has replaced Dmy as the master sex-determining gene in this species. We found that GsdfY showed high expression specifically in males during sex differentiation. Furthermore, the presence of a genomic fragment that included GsdfY converts XX individuals into fertile XX males. Luciferase assays demonstrated that the upstream sequence of GsdfY contributes to the male-specific high expression. Gsdf is downstream of Dmy in the sex-determining cascade of O. latipes, suggesting that emergence of the Dmy-independent Gsdf allele led to the appearance of this novel sex-determining gene in O. luzonensis. 相似文献
110.
Hakoda M Kasagi F Kusunoki Y Matsuura S Hayashi T Kyoizumi S Akahoshi M Suzuki G Kodama K Fujiwara S 《Radiation research》2006,166(2):360-366
Although it has been suggested that cardiovascular disease incidence is increased among atomic bomb survivors, the existence of a causal relationship between radiation exposure and atherosclerosis is unclear. Microbial infections, including those caused by Chlamydia pneumoniae, Helicobacter pylori and cytomegalovirus, have recently been implicated in atherosclerosis. Since immune function is somewhat impaired among atomic bomb survivors, their immune defense against such infections might be diminished. To investigate this possibility, we measured antibody levels to the above microorganisms in the sera of survivors. We found that the levels of IgG and IgA antibodies to Chlamydia pneumoniae decreased significantly with radiation dose, whereas the levels of IgG antibodies to Helicobacter pylori or cytomegalovirus remained unchanged. The inflammation marker C-reactive protein was significantly and positively associated with level of antibodies to Chlamydia pneumoniae only in heavily exposed (>or=1000 mGy) survivors. These results may suggest that among atomic bomb survivors, immune response to Chlamydia pneumoniae is diminished and chronic inflammatory reactions related to Chlamydia pneumoniae infection are present. 相似文献