In Vivo Activation of Azipropofol Prolongs Anesthesia and Reveals Synaptic Targets

General anesthetic photolabels have been instrumental in discovering and confirming protein binding partners and binding sites of these promiscuous ligands. We report the in vivo photoactivation of meta-azipropofol, a potent analog of propofol, in Xenopus laevis tadpoles. Covalent adduction of meta-azipropofol in vivo prolongs the primary pharmacologic effect of general anesthetics in a behavioral phenotype we termed “optoanesthesia.” Coupling this behavior with a tritiated probe, we performed unbiased, time-resolved gel proteomics to identify neuronal targets of meta-azipropofol in vivo. We have identified synaptic binding partners, such as synaptosomal-associated protein 25, as well as voltage-dependent anion channels as potential facilitators of the general anesthetic state. Pairing behavioral phenotypes elicited by the activation of efficacious photolabels in vivo with time-resolved proteomics provides a novel approach to investigate molecular mechanisms of general anesthetics.     

昆明地区昭觉林蛙不同发育期蝌蚪的栖息地利用

通过观察昭觉林蛙(Ranachaochiaoensis)蝌蚪在栖息地的分布状况,统计和分析不同发育期蝌蚪在不同植被盖度、水深和水温下的分布频次。其结果表明,Ⅰ、Ⅱ期蝌蚪更倾向于选择植被盖度为41%—70%的水域;Ⅲ期蝌蚪对植被盖度的选择不明显。Ⅱ期蝌蚪倾向于选择水深为0·11—0·30m的水域;Ⅰ、Ⅲ期蝌蚪对水深的选择不明显,且Ⅲ期蝌蚪在水深大于0·31m的水域无分布。随着蝌蚪生长发育,Ⅰ期至Ⅲ期对水深的选择不断变浅。Ⅰ、Ⅱ期蝌蚪均倾向于选择水温为19—25℃的水域;Ⅲ期蝌蚪对水温的选择不明显,但在水温为8—13℃的水域无分布。     

应用微核试验和单细胞凝胶电泳技术来检测农药对青蛙蝌蚪及成体的遗传毒性

应用青蛙红细胞微核试验和单细胞凝胶电泳试验研究了两种新型杀虫剂 -吡虫啉和抑食肼对青蛙蝌蚪和成体的遗传毒性 ,结果表明 :当吡虫啉为 2mg/L时 ,蝌蚪红细胞微核率与对照组相比 ,无显著性差异 (p >0 .0 5) ;浓度升高到 8mg/L时 ,微核率与对照组相比 ,有显著性差异 (p <0 .0 5) ;当浓度为 3 2mg/L时 ,微核率与对照组相比 ,有极显著性差异 (p <0 .0 1) ;并有明显的剂量 -效应关系 (r =0 .9843 )。而抑食肼在浓度为 2 .5mg/L和 10mg/L时 ,微核率与对照组相比 ,无显著性差异 (p >0 .0 5) ;当浓度增至 40mg/L时 ,微核与对照组相比 ,有极显著性差异 (p <0 .0 1) ;吡虫啉与抑食肼各浓度组对青蛙红细胞的DNA损伤与阴性对照组相比 ,都有极显著性差异 (p <0 .0 1) ,且具有明显的剂量 -效应关系 (r =0 .960 ,r=0 .990 )。     

Immunofluorescence of somatostatin-producing sites in the hypothalamus of the tadpole,Alytes obstetricans Laur.

Summary Three sites of somatostatin-synthesizing perikarya, or a related antigen, were determined by immunofluorescence in the hypothalamus of the tadpole, Alytes obstetricans (Amphibia, Anura). Two sites of neurosecretory perikarya were localized in the preoptic nuclei of the anterior hypothalamus; the axons extended either to the anterior diencephalon or to the median eminence and the pituitary. The third site was found in the posterior hypothalamus. These neurosecretory cells showed a strong immunofluorescent reaction; their axons all terminated at the level of the median eminence. Somatostatin cells were only found in intact or hypophysectomized tadpoles given somatotropin (STH). The strong reaction observed in hypophysectomized tadpoles was possibly due to the loss of the terminal portion of the neurosecretory pathway (median eminence and pituitary) by which the agent is transported to the site of discharge.     

污水和污水土地处理系统中各种水质对华西蟾蜍蝌蚪红细胞微核率的影响

本文使用蝌蚪红细胞微核率作为指示器研究明通河污水和用污水土地处理系统处理后水质的致突变性。蝌蚪在各种水样品中暴露7天。采心脏血制片。在对照组中,微核率分别为4.40‰和4.68‰。1/4明通河污水组诱发蝌蚪的微核率是17.01‰。同对照组相比有明显的差异。     

蝌蚪（Bufo bufo andrewsi）血红细胞微核和核异常监测水质污染的研究

滇池是云南高原最大的淡水湖,是昆明地区工农业生产及人民生活用水的水源,又是昆明市的重要风景区。近年来,滇池水质污染,越来越引起人们的关注。昆明市的工业废水和生活污水经大观河等流入滇池,其中有毒有害物质多达30多种,包括镉、汞、砷、铅、铬、氟、有机磷、氰化物等。其中砷(Léonard et al., 1980;Katsuhiko,     

Evolution of parental care in dart poison frogs (Amphibia: Anura: Dendrobatidae)

Dendrobatid frogs perform a unique mode of parental care, ranging from egg attendance and tadpole transport to tadpole feeding. It is hypothesized that a behaviour in which the egg attending parent remains with the cluch is the most primitive condition. In more advanced forms or parental care, the male is able to attend several clutches of eggs. Tadpole attendance and feeding, finally, started as deceit; the male induced the female to lay eggs into a bromeliad leaf axil already occupied by a larva. Costs and benefits of the different modes of parental care and possible alternative reproductive tactics are discussed.     

Lateral line-mediated rheotactic behavior in tadpoles of the African clawed frog (<Emphasis Type="Italic">Xenopus laevis</Emphasis>)

Tadpoles (Xenopus laevis) have a lateral line system whose anatomical structure has been described, but whose functional significance has not been closely examined. These experiments tested the hypothesis that the lateral line system is involved in rheotaxis. Tadpoles in developmental stages 47–56 oriented toward the source of a water current. Orientation was less precise after treatment with cobalt chloride or streptomycin, but was similar to that of untreated animals after exposure to gentamicin. In no current conditions, tadpoles exhibited a characteristic head-down posture by which they held themselves in the water column at an angle around 45°. This body posture became significantly less tilted in the presence of water current. Treatment with cobalt chloride or streptomycin increased the angle of tilt close to that seen in no current conditions, while gentamicin treatment tended to decrease tilt angle. The data are consistent with anatomical and physiological findings that tadpole neuromasts are similar to superficial, but not canal, neuromasts in fishes, and they suggest that the lateral line system is involved in both directional current detection and current-related postural adjustments in Xenopus.     

Genes induced during the early developmental stages of the Cane Toad, Bufo (Chaunus) marinus

Metamorphosis, a critical stage in the development of toads and frogs, involves rapid levels of morphological change. In the current study, we have used microarray analysis to identify shifts in gene expression between tadpole and toadlet stages of the cane toad, Bufo (Chaunus) marinus. Here, we report on nine genes that show the greatest induction during metamorphosis; the gut-associated gastrokine and trefoil factor, blood components haemoglobins alpha/beta, apolipoprotein and serum albumin, a nasal gene olfactomedin, a lens gene gamma-crystallin, and a novel gene with low homology to frog harderin. We present both temporal and spatial expression patterns of these genes identified in developing and adult cane toads. This study extends our knowledge of the molecular basis of toad metamorphosis, and not only offers insights to the genes induced during the general remodelling that occurs but also reveals possible targets for control and manipulation of amphibian pest species, for example, the cane toad in Australia.     

Larval amphibian growth and development under varying density: are parasitized individuals poor competitors?

Population density and infection with parasites often are important factors affecting the growth and development of individuals. How these factors co-occur and interact in nature should have important consequences for individual fitness and higher-order phenomena, such as population dynamics of hosts and their interactions with other species. However, few studies have examined the joint effects of density and parasitism on host growth and development. We examined the co-influences of rearing density and parasitism, by the trematode Echinostoma trivolvis, on the growth and development of larval frogs, Rana (=Lithobates) pipiens. We also examined the potential role of parasite-mediated intraspecific competition by observing how unparasitized individuals performed when housed with other unparasitized tadpoles, versus housing with a combination of unparasitized and parasitized hosts. Mean mass and mean developmental stage were reduced under high rearing densities. The presence of parasitized conspecifics had no significant effect, but there was a significant interaction of density and parasitism presence on host mass, due to the fact that parasitized conspecifics grew poorly at high densities. Unparasitized individuals reared with parasitized and unparasitized conspecifics fared no better than unparasitized individuals reared only with one another. This result indicates that infected hosts compete as much as uninfected hosts for resources, even though infected individuals have reduced mass under high-density conditions. Resource acquisition and resource allocation are different processes, and parasitism, if it only affects the latter, might not have a discernible impact on competitive interactions.