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This study investigated the effects on genital reflexes of unilateral MPOA injections of 0.1, 1, 3, and 10 micrograms of the D2 agonist quinelorane (LY-163502), and of 3 micrograms quinelorane administered together with 3 micrograms of the D1 antagonist SCH-23390. In addition, the effects of an MPOA injection of 10 micrograms apomorphine were tested. All but the lowest dose of quinelorane significantly decreased the latency to the first reflex. The 3 and 10 micrograms doses of quinelorane, and the combination of quinelorane and SCH-23390, decreased the total number of reflexes. In addition, 10 micrograms quinelorane increased the number of seminal emissions. 10 micrograms apomorphine, like 10 micrograms quinelorane, decreased the latency to the first reflex and increased the number of seminal emissions, but did not decrease the numbers of erections or penile movements. The ratio of D1/D2 activity may influence the number of erections displayed during ex copula testing.  相似文献   
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Tobamoviruses, mostly isolated from solanaceous plants, may represent ancient virus lineages that have codiverged with their hosts. Recently completed nucleotide sequences of six nonsolanaceous tobamoviruses allowed assessment of the codivergence hypothesis and support a third subgroup within tobamoviruses. The genomic sequences of 12 tobamoviruses and the partial sequences of 11 others have been analyzed. Comparisons of the predicted protein sequences revealed three clusters of tobamoviruses, corresponding to those infecting solanaceous species (subgroup 1), those infecting cucurbits and legumes (subgroup 2), and those infecting crucifers. The orchid-infecting odontoglossum ringspot tobamovirus was associated with subgroup 1 genomes by its coat and movement protein sequences, but with the crucifer-pathogenic tobamoviruses by the remainder of its genome, suggesting that it is the progeny of a recombinant. For four of five genomic regions, subgroup 1 and 3 genomes were equidistant from a subgroup 2 genome chosen for comparison, suggesting uniform rates of evolution. A phylogenetic tree of plant families based on the tobamoviruses they harbor was congruent with that based on rubisco sequences but had a different root, suggesting that codivergence was tempered by rare events of viruses of one family colonizing another family. The proposed subgroup 3 viruses probably have an origin of virion assembly in the movement protein gene, a large (25-codon) overlap of movement and coat protein open reading frames, and a comparably shorter genome. Codon-position- dependent base compositions and codon prevalences suggested that the coat protein frame of the overlap region was ancestral. Bootstrapped parsimony analysis of the nucleotides in the overlap region and of the sequences translated from the -1 frame (the subgroup 3 movement protein frame) of this region produced trees inconsistent with those deduced from other regions. The results are consistent with a model in which a no or short overlap organization was ancestral. Despite encoding of subgroup 2 and 3 movement protein C-termini by nonhomologous nucleotides, weak similarities between their amino acid sequences suggested convergent sequence evolution.   相似文献   
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Background  

Reliable segmentation of cell nuclei from three dimensional (3D) microscopic images is an important task in many biological studies. We present a novel, fully automated method for the segmentation of cell nuclei from 3D microscopic images. It was designed specifically to segment nuclei in images where the nuclei are closely juxtaposed or touching each other. The segmentation approach has three stages: 1) a gradient diffusion procedure, 2) gradient flow tracking and grouping, and 3) local adaptive thresholding.  相似文献   
98.

Background  

Automated identification of cell cycle phases of individual live cells in a large population captured via automated fluorescence microscopy technique is important for cancer drug discovery and cell cycle studies. Time-lapse fluorescence microscopy images provide an important method to study the cell cycle process under different conditions of perturbation. Existing methods are limited in dealing with such time-lapse data sets while manual analysis is not feasible. This paper presents statistical data analysis and statistical pattern recognition to perform this task.  相似文献   
99.
A series of compounds which possess both thromboxane receptor antagonist and synthase inhibitory activity has been generated by incorporating any arylsulphonamide group into the synthase inhibitors CV4151 and R68070.  相似文献   
100.
Incorporation of a pyridine miety into amino-prostanoids, previously shown to be thromboxane receptor antagonists, has provided a series of compounds which also show potent thromboxane synthase inhibitory activity. GR 83783, an npropyl-substituted pyridine demonstrates these properties both in vitro and in vivo.  相似文献   
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