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121.
IgG from antiserum against endogenous mammalian FMRF-NH2-related peptides augments morphine- and stress-induced analgesia in mice 总被引:2,自引:1,他引:1
Two mammalian FMRF-NH2-like peptides have been isolated from bovine brain; an octapeptide with the structure Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2 (F-8-F-NH2) and an octadecapeptide, Ala-Gly-Glu-Gly-Leu-Ser-Ser-Pro-Phe-Trp-Ser-Leu-Ala-Ala-Pro-Gln-Arg-Phe- NH2 (A-18-F-NH2). In the present study determinations were made of the effects of intracerebroventricular administration of IgG prepared from antisera raised against these peptides on nociception and morphine- and immobilization-induced opioid analgesia in mice. Both F-8-F-NH2-IgG and A-18-F-NH2-IgG antisera increased nociception (thermal response latency) and significantly augmented morphine- and immobilization-induced analgesia in a naloxone reversible manner, with F-8-F-NH2-IgG antisera having a greater effect than A-18-F-NH2-IgG antisera. These results provide further evidence that mammalian FMRF-NH2-like peptides function as endogenous opiate antagonists and have a role in the mediation of antinociception. 相似文献
122.
仙茅属三个国产种的核型研究 总被引:1,自引:0,他引:1
本文报道了中国产三种仙茅植物的核型。1.绒叶仙茅Curculigo crassifolia (Baker) Hook. f., 2n=2x=18=10m(4SAT) 8 sm;2.大叶仙茅C.capitulata(Lour.)O. Kuntze,2n=2x=18=10(2SAT) 8sm;3.中华仙茅C.sinensis S.C.Chen,2n=2x=18=8m(3SAT) 10sm(2SAT)。其中中华仙茅的核型为首次报道。虽然三种仙茅的核型都是“2B”型,但中华仙茅的核型不对称性比绒叶仙茅和大叶仙茅强。 相似文献
123.
通过细胞学观察,在普通小麦栽培品种“丰抗13”和“京红1号”的杂交后代中,发现有多价体出现,这就表明有染色体易位发生。为进一步弄清究竟是哪条染色体发生了易位,我们采用单体测交方法,观察鉴定所有各单体系F_1的花粉母细胞第一次减数分裂中期Ⅰ(以下简称PMCs中Ⅰ)染色体构型。从鉴定结果发现,凡2n=42的F_1 PMCs中Ⅰ出现19~Ⅱ 1~Ⅳ,而2n=41的F_1PMCs中Ⅰ的染色体构型不同,单体与易位有关的两个单体系4B和1D F_1 PMCs中的Ⅰ构型中有部分呈现为19个二价体加1个三价体,即19~Ⅱ 1~Ⅲ,没有单价体,而其余各单体系F_1 PMCs中Ⅰ构型则表现为18个二价体,1个四价体和1个单价体,即18~Ⅱ 1~Ⅰ 1~Ⅳ。因此,可以肯定“丰抗13”存在1个染色体易位,其有关染色体就是4B和1D。 相似文献
124.
苦绳的一个新甾体成分 总被引:2,自引:0,他引:2
从苦绳(Dregea sinensis Hemsl.),和分出一新的甾体成分,Dresigenin A(I),经化学反应及光谱分析证明其结构为12-O-乙酰基-20-O-(2-甲基丁酰基)二氢肉珊瑚甙元[12-O-acetyl-20-O-(2-methylbutyryl)dihydrosarcostin]。 相似文献
125.
眼镜蛇科蛇毒对S180,EAC腹水癌治疗作用研究 总被引:1,自引:0,他引:1
本文报道金环蛇、扁颈蛇、眼镜蛇、银环蛇蛇毒及其细胞毒对小鼠S180,EAC腹水癌的治疗作用。结果表明,蛇毒及其细胞毒在体外有明显杀灭癌细胞作用,体内有较明显的治疗作用,动物存活时间延长,接种率降低。肿瘤细胞呈现不同程度形态变化,主要为膜破裂,坏死等。治疗效应由强到弱为金环蛇毒,扁颈蛇毒,金环蛇细胞毒,眼镜蛇毒,眼镜蛇细胞毒。银环蛇毒无作用。 相似文献
126.
Substitution of an invariant nucleotide at the base of the highly conserved ''530-loop'' of 15S rRNA causes suppression of yeast mitochondrial ochre mutations. 总被引:17,自引:7,他引:10
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We have determined the nucleotide sequence alteration in the 15S rRNA gene of a Saccharomyces cerevisiae strain carrying the previously described mitochondrial ochre suppressor, MSUI. The suppressor contains an A residue at position 633 of the yeast mitochondrial sequence, in place of the wild-type G. This position, located in the highly conserved region forming the stem of the '530-loop', corresponds to G517 of the Escherichia coli 16S rRNA and is occupied by G in all other known small rRNA sequences. This finding strongly supports the previous conclusions of others that the 530-loop region plays an important role in enhancing translational accuracy. 相似文献
127.
128.
X Y Wei A Rutledge Q Zhong J Ferrante D J Triggle 《Canadian journal of physiology and pharmacology》1989,67(5):506-514
The voltage-sensitive calcium channel in cultured chick neural retina cells was characterized by the actions of the enantiomers of Bay K 8644 and 202-791 and other 1,4-dihydropyridines. These cells showed time- and voltage-dependent Ca2+ uptake that was stimulated by K+ depolarization and blocked by the inorganic calcium channel blockers Cd2+ and Co2+. A small fraction only (15% maximum) of the uptake was inactivated by predepolarization of the cells with 80 mM K+. Ca2+ uptake was sensitive to the 1,4-dihydropyridine calcium channel antagonists and activators. (S)-Bay K 8644 and (S)-202-791 stimulated the Ca2+ uptake, and (R)-Bay K 8644 and (R)-202-791 as well as nitrendipine and PN 200-110 inhibited Ca2+ uptake stimulated by K+ depolarization or channel activators. The K+ depolarization-stimulated uptake was inhibited by 90%, but the activator-stimulated uptake was completely blocked by the 1,4-dihydropyridine antagonists. The potencies of these agents as inhibitors of Ca2+ uptake were significantly lower than the binding affinities in membrane preparations from the same cells or their binding and pharmacologic affinities in vascular smooth muscle. K+ depolarization or (S)-Bay K 8644 induced 45Ca2+ uptake was not observed in a glial cell culture. [3H]Nitrendipine and [3H]PN 200-110 bound to membrane preparations of the cells consistent with the presence of a single type of high affinity binding site.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
129.
Higher order structure is present in the yeast nucleus: autoantibody probes demonstrate that the nucleolus lies opposite the spindle pole body 总被引:5,自引:0,他引:5
A panel of sera from 892 autoimmune patients was screened by indirect immunofluorescence on mammalian cells. Seventy-three sera were identified that recognize the nucleolus. Three of these sera appear to stain the nucleolus in yeast, suggesting that they recognize highly conserved antigens. These three sera also immunoprecipitate mammalian U3 snRNA-containing particles, which reside in the nucleolus and have been implicated in rRNA processing. Double immunofluorescence experiments with anti-nucleolus and anti-tubulin antibodies revealed a novel form of non-random nuclear organization in yeast. The spindle pole body and the nucleolus — both of which are associated with the nuclear envelope — preferentially localize at opposite ends of the nucleus. Organization of these and other components into specific regions of the nucleus may be important for optimizing their proper function. 相似文献
130.
Nonparametric confidence interval estimators for heritability and expected selection response 总被引:2,自引:1,他引:1
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Statistical methods have not been described for comparing estimates of family-mean heritability (H) or expected selection response (R), nor have consistently valid methods been described for estimating R intervals. Nonparametric methods, e.g., delete-one jackknifing, may be used to estimate variances, intervals, and hypothesis test statistics in estimation problems where parametric methods are unsuitable, nonrobust, or undefinable. Our objective was to evaluate normal-approximation jackknife interval estimators for H and R using Monte Carlo simulation. Simulations were done using normally distributed within-family effects and normally, uniformly, and exponentially distributed between-family effects. Realized coverage probabilities for jackknife interval (2) and parametric interval (5) for H were not significantly different from stated probabilities when between-family effects were normally distributed. Coverages for jackknife intervals (3) and (4) for R were not significantly different from stated coverages when between-family effects were normally distributed. Coverages for interval (3) for R were occasionally significantly less than stated when between-family effects were uniformly or exponentially distributed. Coverages for interval (2) for H were occasionally significantly less than stated when between-family effects were exponentially distributed. Thus, intervals (3) and (4) for R and (2) for H were robust. Means of analysis of variance estimates of R were often significantly less than parametric values when the number of families evaluated was 60 or less. Means of analysis of variance estimates of H were consistently significantly less than parametric values. Means of jackknife estimates of H calculated from log transformed point estimates and R calculated from untransformed or log transformed point estimates were not significantly different from parametric values. Thus, jackknife estimators of H and R were unbiased. Delete-one jackknifing is a robust, versatile, and effective statistical method when applied to estimation problems involving variance functions. Jackknifing is especially valuable in hypothesis test estimation problems where the objective is comparing estimates from different populations. 相似文献