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1.
H2S+ bacteria responsible for the degradation of sulfur-containing amino acids of fish muscle are currently little used to evaluate the microbiological pal quality of fish. Shewanella putrefaciens greatly predominates in this flora, and was therefore used to define a suitable culture method and medium. Inoculations by the Spiral surface method at 25C, with an incubation of 72h, gave the best counts on a medium containing two sources of sulfur (organic and inorganic) for H2S+ bacteria. The culture medium and the NaCl concentration were determinant in the evaluation of this flora. At present there is no standard medium which meets these requirements.  相似文献   
2.
RNA molecules that bind tightly and specifically to a Rex fusion protein have been isolated from a conformationally constrained pool of random sequence RNAs. The anti-Rex aptamers effectively mimic several features of the wild-type Rex-binding element (XBE). The highest-affinity aptamers effectively compete with the wild-type XBE for binding to the RNA-binding domain of Rex, an arginine-rich motif (ARM), but do not bind to the functionally analogous Rev protein or its ARM. However, characteristic sequence and structural motifs found in some of the anti-Rex aptamers may provide insights into how the Rex protein can interact with other viral RNAs, such as the Rev-responsive element. The anti-Rex aptamers can functionally substitute for the XBE in vivo, a result which supports a previously proposed model for mRNA transport in which the viral genome serves as a platform for assembling a nucleoprotein complex that can co-opt the cellular transport apparatus. Overall, these studies suggest that anti-Rex aptamers may serve as RNA decoys of the Rex protein.  相似文献   
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The use of mebendazole-treated diet (60 ppm) effectively controlled Hymenolepis nana and Aspiculuris tetraptera in a large mouse breeding colony. In a 3 generation pilot study using a medicated diet, there was some reduction in litter size and in female growth rate and an overall 2.07% incidence of kinky tails in the offspring. When the whole mouse colony was fed mebendazole-treated diet, a high incidence of kinky tails (maximum 46% of weaned offspring) occurred.  相似文献   
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Six discrete protease activities were recovered from the supernatant broth of Legionella pneumophila cultures by ion-exchange chromatography. One of these demonstrated in vitro activity against collagen, casein and gelatin. When administered into the lungs of guinea-pigs this protease elicited lesions which were pathologically similar to those seen in clinical and experimentally induced Legionnaires' disease.  相似文献   
7.

Background  

In S. cerevisiae, the mitotic exit network (MEN) proteins, including the Polo-like protein kinase Cdc5 and the protein phosphatase Cdc14, are required for exit from mitosis. In pre-anaphase cells, Cdc14 is sequestered to the nucleolus by Net1 as a part of the RENT complex. When cells are primed to exit mitosis, the RENT complex is disassembled and Cdc14 is released from the nucleolus.  相似文献   
8.
Vomeronasal/accessory olfactory system and pheromonal recognition   总被引:2,自引:0,他引:2  
Keverne  EB 《Chemical senses》1998,23(4):491-494
Pregnancy block in mice requires exposure of recently mated females tourinary pheromones of a strange male, and when working with inbred strainsthis invariably requires urine from an outbred line. The pheromones whichinduce oestrus and early puberty in mice have been identified as thebrevicomins and dihydrothiazoles. Since the same vomeronasal, neural andneuroendocrine pathways are also activated in pregnancy block, thesecompounds are likely candidates for pregnancy blocking pheromones. However,these relatively simple chemicals lack the capacity to code for differingmouse strains. Since large quantities of the polymorphic major urinaryproteins from the lipocalin family found in urine serve as transporters forthe dihydrothiazoles and brevicomins, and differ across strains, then theseproteins must participate in pheromone recognition in the context ofpregnancy block.  相似文献   
9.

Background  

The integration of many aspects of protein/DNA structure analysis is an important requirement for software products in general area of structural bioinformatics. In fact, there are too few software packages on the internet which can be described as successful in this respect. We might say that what is still missing is publicly available, web based software for interactive analysis of the sequence/structure/function of proteins and their complexes with DNA and ligands. Some of existing software packages do have certain level of integration and do offer analysis of several structure related parameters, however not to the extent generally demanded by a user.  相似文献   
10.
We reported previously that endogenous p38 MAPK activity is elevated in invasive breast cancer cells and that constitutive p38 MAPK activity is important for overproduction of uPA in these cells (Huang, S., New, L., Pan, Z., Han, J., and Nemerow, G. R. (2000) J. Biol. Chem. 275, 12266-12272). However, it is unclear how elevated endogenous p38 MAPK activity is maintained in invasive breast cancer cells. In the present study, we found that blocking alpha(v) integrin functionality with a function-blocking monoclonal antibody or down-regulating alpha(v) integrin expression with alpha(v)-specific antisense oligonucleotides significantly decreased the levels of active p38 MAPK and inhibited cell-associated uPA expression in invasive breast cancer MDA-MB-231 cells. These results suggest a function link between alpha(v) integrin, p38 MAPK activity, and uPA expression in invasive tumor cells. We also found that vitronectin/alpha(v) integrin ligation specifically induced p38 MAPK activation and uPA up-regulation in invasive MDA-MB-231 cells but not in non-invasive MCF7 cells. Finally, using a panel of melanoma cells, we demonstrated that the cytoplasmic tail of alpha(v) integrin subunit is required for alpha(v) integrin ligation-induced p38 MAPK activation.  相似文献   
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