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91.
The causal agents of witches' broom of bamboo plants in East Asia, Epichloë bambusae and E. sasae, were morphologically and phylogenetically examined. The phylogenetic studies were conducted using ITS 1, 2, and 5.8 S rDNA regions. Both Epichloë species produce Ephelis-type conidia in artificial medium and are phylogenetically situated in different clades from Epichloë and Parepichloë. Here, we propose a new genus Heteroepichloë for these two bambsicolous Epichloë species.  相似文献   
92.
Leukemia inhibitory factor (LIF) is a cytokine, which inhibits angiogenesis and decreases endothelial cell proliferation and migration, suggesting that LIF may modulate vascular tone. In this study, we examined the effects of LIF on the tone of rat arteries. The isometric tension of ring preparations from rat superior mesenteric arteries was continuously measured. LIF relaxed the mesenteric arteries in a dose-dependent manner, when the arterial rings were precontracted with phenylephrine. The relaxation was totally inhibited by mechanical removal of endothelium. N(G)-nitro-L-arginine methyl ester did not affect the relaxation by LIF. Ca(2+)-dependent K channel (KCa) blockers, apamin with charybdotoxin, inhibited the relaxation by LIF. Catalase, an enzyme which scavenges hydrogen peroxide, also inhibited the relaxation by LIF. Endothelium-derived hyperpolarizing factor relaxes smooth muscle cells and the effect is blocked by KCa and catalase. Our results suggest that LIF regulates vascular tone through the effect of this factor.  相似文献   
93.
Enthalpy changes (Delta H) of the photointermediates that appear in the photolysis of octopus rhodopsin were measured at physiological temperatures by the laser-induced transient grating method. The enthalpy from the initial state, rhodopsin, to bathorhodopsin, lumirhodopsin, mesorhodopsin, transient acid metarhodopsin, and acid metarhodopsin were 146 +/- 15 kJ/mol, 122 +/- 17 kJ/mol, 38 +/- 8 kJ/mol, 12 +/- 5 kJ/mol, and 12 +/- 5 kJ/mol, respectively. These values, except for lumirhodopsin, are similar to those obtained for the cryogenically trapped intermediate species by direct calorimetric measurements. However, the Delta H of lumirhodopsin at physiological temperatures is quite different from that at low temperature. The reaction volume changes of these processes were determined by the pulsed laser-induced photoacoustic method along with the above Delta H values. Initially, in the transformation between rhodopsin and bathorhodopsin, a large volume expansion of +32 +/- 3 ml/mol was obtained. The volume changes of the subsequent reaction steps were rather small. These results are compared with the structural changes of the chromophore, peptide backbone, and water molecules within the membrane helixes reported previously.  相似文献   
94.
The objective of this experiment was to determine the effect of AA, LH, or PSPB on secretion of PGE2, PGF2alpha, or progesterone by ovine caruncular endometrium of the estrous cycle or placental tissue of pregnancy in vitro. Ovine caruncular endometrium of the estrous cycle (days 8, 11, 13, and 15) or caruncular/placental tissue on days 8, 11, 13, 15, 20, 30, 40, 50, 60, and 90 postbreeding were incubated in vitro with vehicle, AA, LH, or PSPB in M-199 for 4 and 8 h. Secretion of PGF2alpha by caruncular endometrium of non-bred ewes on days 13 and 15 and by caruncular/placental tissue of bred ewes on days 13, 15, 20, 30, and 40 was increased (P < or = 0.05) when incubated with vehicle and declined (P < or = 0.05) after day-40 in bred ewes. Secretion of PGF2alpha by day-15 caruncular endometrium of non-bred ewes and bred ewes was increased (P < or = 0.05) by AA on days 13 and 15 and by LH on day-15. Secretion of PGF2alpha by caruncular/placental tissue from bred ewes was (P < or = 0.05) by AA on days 13, 15, 20, 30, and 40 and by LH on days 15, 20, 30, and 40, after which the response decreased (P < or = 0.05). Secretion of PGF2alpha by caruncular endometrium of non-bred ewes during the estrous cycle or by caruncular/placental tissue of bred ewes during the first trimester was not affected by PSPB (P > or = 0.05). Secretion of PGE2 by caruncular endometrium of non-bred ewes did not change (P > or = 0.05) and was increased (P < or = 0.05) by caruncular/placental tissue on days 13-90 from bred ewes when incubated with vehicle. Secretion of PGE2 by endometrium from non-bred ewes was not affected (P > or = 0.05) by AA, LH, or PSPB, but was increased (P < or = 0.05) by AA or LH on days 13-50 and by PSPB on days 60 and 90 when incubated with caruncular/placental tissue from bred ewes. Secretion of progesterone by placental tissue of bred ewes increased (P < or = 0.05) on day-50 and continued to increase through day-90. In summary, uterine/placental tissue secretion of PGF2alpha is not reduced until the end of the first trimester of pregnancy in ewes. In addition, LH appears to play a role in luteolysis of non-bred ewes by stimulating caruncular endometrial secretion of PGF2alpha and on day-5 postbreeding to prevent luteolysis during early pregnancy by stimulating caruncular/placental secretion of PGE2 throughout the first trimester of pregnancy in sheep. Secretion of PGE2 by caruncular/placental tissue after day-50 of pregnancy appears to be regulated by PSPB, not LH.  相似文献   
95.
Aciculosporium take (Ascomycota; Clavicipitaceae), causes the witches' broom disease in bamboo, particularly Phyllostachys bambusoides. Since it was observed that endogenous indole-3-acetic acid is reduced in the twigs of the diseased bamboo, the symptoms (bushy appearance) may be induced by reduction in auxin levels. Furthermore, two indolic compounds accumulated in diseased twigs, these being identified as N-p-coumaroylserotonin and N-feruloylserotonin by LC-MS, 1H NMR and 13C NMR spectroscopic analyses. N-p-Coumaroylserotonin possesses antifungal activity against A. take.  相似文献   
96.
Two members of a new class of C-nor-D-homo steroidal alkaloids, impranine (1). and dihydroimpranine (2). along with a new pyridyl-pregnane-type steroidal alkaloid, fetisinine (3). and a known base, korsevine (4). were isolated from the bulbs of Fritillaria imperialis. The structures of the compounds were established on the basis of spectroscopic techniques and some chemical transformations. Compounds 1 and 2 form a new class of steroidal alkaloids, named as "impranane."  相似文献   
97.
A mouse nanos (nanos1) gene was cloned and its function was examined by generating a gene-knockout mouse. The nanos1 gene encodes an RNA-binding protein, which contains a putative zinc-finger motif that exhibits similarity with other nanos-class genes in vertebrates and invertebrates. Although nanos1 is not detected in primordial germ cells, it is observed in seminiferous tubules of mature testis. Interestingly, maternally expressed nanos1 is observed in substantial amounts in oocytes, but the amount of maternal RNA is rapidly reduced after fertilization, and the transient zygotic nanos1 expression is observed in eight-cell embryos. At 12.5 days postcoitum, nanos1 is re-expressed in the central nervous system and the expression continues in the adult brain, in which the hippocampal formation is the predominant region. The nanos1 -deficient mice develop to term without any detectable abnormality and they are fertile. No significant neural defect is observed in terms of their behavior to date.  相似文献   
98.
We cloned cDNA of three variants of BtR175, a putative Bombyx mori receptor for Bacillus thuringiensis Cry1Aa delta-endotoxin by PCR. These variants were likely to be allelic to BtR175. cDNA of BtR175b, the most distant variant from BtR175, was introduced into mammalian cells. BtR175b protein was expressed in the plasma membrane of the cells and showed binding activity to Cry1Aa.  相似文献   
99.
100.
Chemoprevention of lung cancer by lycopene   总被引:1,自引:0,他引:1  
An investigation was conducted to assess the chemopreventive potential of lycopene (LP), a naturally occurring hydrocarbon carotenoid found in tomatoes and their products, administered during the post-initiation stage in a multiorgan carcinogenesis model. One hundred eighteen B6C3F1 mice of both sexes were subjected to combined treatment with diethylnitrosamine (DEN), N-methyl-N-nitrosourea (MNU) and 1,2-dimethylhydrazine (DMH) from day 11 after birth to week 9 (DMD treatment) (groups 1 and 2) or given their vehicles (group 3). Then group 1 received LP (25 or 50 ppm in drinking water) for 21 weeks from weeks 11 to 32. Group 2 served as a carcinogen alone control and group 3 was given only LP (25 or 50 ppm). The incidences and multiplicities of lung adenomas plus carcinomas combined in male mice in group 1 receiving LP 50 ppm were significantly decreased as compared to the DMD alone or DMD and LP 25 ppm group values (75.0 vs 18.8%, P < 0.02; 0.94+/-0.17 v.s 0.25+/-0.14, P < 0.001). While hepatocellular carcinomas were lacking in the DMD and LP groups, two cases were found in the DMD alone group (not statistically significant). The values for aberrant crypt foci (ACF) and tumors in the colon and kidney did not show any significant variation among the carcinogen-treated subgroups. The results of this study provide evidence that the tomato carotenoid, lycopene, may have potential as a chemopreventive agent against carcinogenesis in the male lung.  相似文献   
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