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81.
C B Pert J A Danks M A Channing W C Eckelman S M Larson J M Bennett T R Burke K C Rice 《FEBS letters》1984,177(2):281-286
A fluoro-analogue of the potent narcotic antagonist, naltrexone, was synthesized and shown to bind with high affinity to opiate receptors in vitro. 3-[18F]acetylcyclofoxy was prepared via a one-step triflate displacement reaction with the positron emitting 18F ion from tetraethylammonium [18F] fluoride. 3-[18F]acetylcyclofoxy accumulation in opiate receptor rich brain regions of both rat and baboon is shown to be completely displaced by the active enantiomer of naloxone [-)-naloxone) while the identical dose of the pharmacologically inert (+)-naloxone has no detectable effect. Moreover, both rat and baboon brain showed the well documented, typical opiate receptor distribution so that basal ganglia and thalamus are clearly visible in the living baboon brain up to 95 min after intravenous injection of 3-[18F] acetylcyclofoxy. We expect that 3-[18F )acetylcyclofoxy will be a useful probe for visualizing opiate receptors in living humans. 相似文献
82.
BRONWYN W. WILLIAMS DWAYNE R. ETTER DANIEL W. LINDEN KELLY F. MILLENBAH SCOTT R. WINTERSTEIN KIM T. SCRIBNER 《The Journal of wildlife management》2009,73(1):26-34
ABSTRACT Estimation of abundance is important for assessing population responses to management actions. Accurate abundance estimates are particularly critical for monitoring temporal variation following reintroductions when the management goal is to attain population sizes capable of sustaining harvest. Numerous reintroductions have taken place in the Great Lakes region of North America, including efforts to restore extirpated fishers (Martes pennanti) and American martens (M. americana). We used a DNA-based noninvasive hair-snaring method based on one trap design and trapping -grid configuration, and evaluated capture—mark—recapture (CMR) analytical approaches to simultaneously estimate population size for co-distributed fishers and American martens in a 671-km2 area of the Ottawa National Forest in the western Upper Peninsula of Michigan, USA. We included harvest as a final recapture period to increase probability of recapture and to evaluate potential violations of geographic closure assumptions. We used microsatellite markers to identify target species, eliminate congener species, and provide individual identity for estimation of abundance. Population estimates for fishers and martens on the study area ranged from 35 to 60 and 8 to 28, respectively. Estimators incorporating harvest data resulted in up to a 40% increase in abundance estimates relative to estimators without harvest. We considered population estimates not including harvest data the most appropriate for the study due to timing of sampling and environmental factors, but inclusion of harvested individuals was shown to be useful as a means to detect violations of the assumption of geographic closure. We suggest improvements on future CMR sampling designs for larger landscape scales of relevance to management through incorporation of habitat or historical harvest data. Noninvasive genetic methods that simultaneously estimate the numerical abundance of co-distributed species can greatly decrease assessment costs relative to traditional methods, and increase resulting demographic and ecological information. 相似文献
83.
A novel catalytic methanolysis can be induced by a natural cyclooligosaccharide, a cyclosophoraose (cyclic-(1-->2)-beta-D-glucan, Cys), which is a member of a family of unbranched cyclooligosaccharides produced as intra- or extraoligosaccharides by soil microorganisms of the genus, Rhizobium. Cys catalyzed the methanolysis for 5(4H)-oxazolones and various phospholipids. Cys enhanced the methanolysis reaction about 9200-fold for a benzylidene oxazolone or 250-fold for dipalmitoylphosphatidylcholine comparing with control. In this study, we describe that natural cyclosophoraoses isolated from the Rhizobium species function as catalytic carbohydrates for the methanolysis. 相似文献
84.
本文以对氨基苯甲酸为原料,经过重氮化、偶合、成盐等反应,合成4个抗肺癌转移药,并作了红外鉴定。 相似文献
85.
86.
昆虫肠道蛋白酶作用下δ内毒素的毒性肽及毒力特异性的变化* 总被引:3,自引:1,他引:2
本文报道杀斜纹夜娥(Prodenia lirura)δ-内毒素和杀鞘翅目昆虫δ-内毒素经昆虫肠液蛋白酶及胰蛋白酶作用后,其毒性肽及毒力特异性的变化。 以Sephadex G75柱层析提纯的130kD原毒素,经斜纹夜蛾幼虫肠液蛋白酶作用后,产生的70kD与75kD抗蛋白酶多肽(PRP)对斜纹夜蛾和家蚕皆有毒;经家蚕幼虫肠液蛋白酶作用后,产生的62kD与65kD的PRP失去对斜纹夜蛾的毒性,仅对家蚕有毒;经胰蛋白酶作用后产生的65kD与68kD的PRP,其毒力特性与经家蚕肠液蛋白酶作用后的相似。斜纹夜蛾肠液蛋白酶作用后产生的PRP,可进一步被家蚕肠液蛋白酶或胰蛋白酶降解为63-65kD的PRP,此种多肽对斜纹夜蛾无毒,对家蚕有毒。杀鞘翅目昆虫的原毒素不能为胰蛋白酶和粘虫肠液所完全降解。证明不同种类昆虫的肠道蛋白酶对占-内毒素蛋白质的作用位点不同,δ-内毒素对宿主昆虫的毒力特异性与其肠道蛋白酶的特性密切相关。 相似文献
87.
刚羽化的淡色库蚊(Culex pipiens pallens)去首后,其第I卵泡停滞在N期,不能进一步发育。 5天以上日龄滞育蚊去首后,第I卵泡约在去首后24小时即从N期开始发育。 组织切片发现,滞育蚊咽侧体(CA)体积小,形态瘦长,略呈圆锥形,胞核着色深,排列紧密,胞质少,似处于失活状态。 滞育蚊卵巢转种到发育蚊体内,其卵泡可以发育,而转种到滞育蚊体内则不能发育。类保幼激素(JHA,ZR515)及从发育蚊血淋巴液中提取的粗制保幼激素都能使滞育蚊的卵泡发育。 相似文献
88.
We have isolated a new hematoside from guinea pig kidney. Like the usual hematoside (II3NeuAc LacCer), isolated from human erythrocytes, this new hematoside contained glucose, galactose, and N-acetylneuraminic acid in an equimolar proportion. By thin-layer chromatography (TLC), however, it migrated faster than the usual hematoside. After mild alkaline hydrolysis the TLC mobility of this ganglioside became identical to that of the usual hematoside. The sialic acid in this ganglioside was susceptible to Clostridial neuraminidase. Based on TLC mobility and the results of periodate oxidation, the sialic acid of the new hematoside was identified as 9-O-acetyl-N-acetylneuraminic acid. Therefore, the structure of this new hematoside is 9-O-Ac-NeuAc alpha 2 leads to 3Gal beta 1 leads to 4GLc beta 1 leads to 1'Cer. 相似文献
89.
Fate of newly synthesized histones in G1 and G0 cells 总被引:2,自引:0,他引:2
We have shown that quiescent cells as well as those in the G1 phase of the cell cycle synthesize histones at a reduced but significant rate. Now, we show that the histones synthesized during G0 and G1 are stably incorporated into nuclei soon after synthesis. Micrococcal nuclease digestion of nuclei isolated from cells in G0 and G1 revealed that the specific histone variants synthesized in these different physiological states are found associated with DNA as nucleosomes. Nucleosomes were separated by polyacrylamide gel electrophoresis in a reducing buffer so that histone spot morphology, particularly that of the H3s was improved. 相似文献
90.
We have studied the effects of dibromothymoquinone (DBMIB) in various redox activities of the succinate-cytochrome c span of the mitochondrial respiratory chain. At concentrations higher than 50 mol/mol of cytochrome c1 the inhibitor produces a bypass of electron transfer on the substrate side of the bc1 complex, because of its autooxidation capability. This induces an artifactual overestimation of the real inhibition titer of the redox activity of this enzyme, which has been found to be 3-6 mol/mol of cytochrome c1 by following the ubiquinol-cytochrome c reductase activity. This action is reversed by addition of excess of sulphydryl compounds like cysteine. 相似文献