982 resultados para TRAD-MCN BIOASSAY
Resumo:
Cet article présente les résultats de la revue systématique: Inglis SC, Clark RA, McAlister FA, et al. Structured telephone support or telemonitoring programmes for patients with chronic heart failure. Cochrane Database Systematic Reviews 2010, Issue 8. Art. No.:CD007228. DOI:10.1002/14651858.CD007228.pub2. PMID: 20687083.
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Odorant receptor (OR) genes constitute with 1200 members the largest gene family in the mouse genome. A mature olfactory sensory neuron (OSN) is thought to express just one OR gene, and from one allele. The cell bodies of OSNs that express a given OR gene display a mosaic pattern within a particular region of the main olfactory epithelium. The mechanisms and cis-acting DNA elements that regulate the expression of one OR gene per OSN - OR gene choice - remain poorly understood. Here, we describe a reporter assay to identify minimal promoters for OR genes in transgenic mice, which are produced by the conventional method of pronuclear injection of DNA. The promoter transgenes are devoid of an OR coding sequence, and instead drive expression of the axonal marker tau-β-galactosidase. For four mouse OR genes (M71, M72, MOR23, and P3) and one human OR gene (hM72), a mosaic, OSN-specific pattern of reporter expression can be obtained in transgenic mice with contiguous DNA segments of only ~300 bp that are centered around the transcription start site (TSS). The ~150bp region upstream of the TSS contains three conserved sequence motifs, including homeodomain (HD) binding sites. Such HD binding sites are also present in the H and P elements, DNA sequences that are known to strongly influence OR gene expression. When a 19mer encompassing a HD binding site from the P element is multimerized nine times and added upstream of a MOR23 minigene that contains the MOR23 coding region, we observe a dramatic increase in the number of transgene-expressing founders and lines and in the number of labeled OSNs. By contrast, a nine times multimerized 19mer with a mutant HD binding site does not have these effects. We hypothesize that HD binding sites in the H and P elements and in OR promoters modulate the probability of OR gene choice.
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The elucidation of mechanisms underlying telencephalic neural development has been limited by the lack of knowledge regarding the molecular and cellular aspects of the ganglionic eminence (GE), an embryonic structure that supplies the brain with diverse sets of GABAergic neurons. Here, we report a comprehensive transcriptomic analysis of this structure including its medial (MGE), lateral (LGE) and caudal (CGE) subdivisions and its temporal dynamics in 12.5 to 16 day-old rat embryos. Surprisingly, comparison across subdivisions showed that CGE gene expression was the most unique providing unbiased genetic evidence for its differentiation from MGE and LGE. The molecular signature of the CGE comprised a large set of genes, including Rwdd3, Cyp26b1, Nr2f2, Egr3, Cpta1, Slit3, and Hod, of which several encode cell signaling and migration molecules such as WNT5A, DOCK9, VSNL1 and PRG1. Temporal analysis of the MGE revealed differential expression of unique sets of cell specification and migration genes, with early expression of Hes1, Lhx2, Ctgf and Mdk, and late enrichment of Olfm3, SerpinE2 and Wdr44. These GE profiles reveal new candidate regulators of spatiotemporally governed GABAergic neuronogenesis.
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A multiwell plate bioassay was developed using genetically modified bacteria (bioreporter cells) to detect inorganic arsenic extracted from rice. The bacterial cells expressed luciferase upon exposure to arsenite, the activity of which was detected by measurement of cellular bioluminescence. The bioreporter cells detected arsenic in all rice varieties tested, with averages of 0.02-0.15 microg of arsenite equivalent per gram of dry weight and a method detection limit of 6 ng of arsenite per gram of dry rice. This amounted to between approximately 20 and 90% of the total As content reported by chemical methods for the same sample and suggested that a major proportion of arsenic in rice is in the inorganic form. Calibrations of the bioassay with pure inorganic and organic arsenic forms showed that the bacterial cells react to arsenite with highest affinity, followed by arsenate (with 25% response relative to an equivalent arsenite concentration) and trimethylarsine oxide (at 10% relative response). A method for biocompatible arsenic extraction was elaborated, which most optimally consisted of (i) grinding rice to powder, (ii) mixing with an aqueous solution containing pancreatic enzymes, (iii) mechanical shearing, (iv) extraction in mild acid conditions and moderate heat, and (v) centrifugation and pH neutralization. Detection of mainly inorganic arsenic by the bacterial cells may have important advantages for toxicity assessment of rice consumption and would form a good complement to total chemical arsenic determination.
Resumo:
An oat bioassay was conducted in pots under greenhouse conditions to determine the persistence of atrazine, metribuzin and simazine herbicides in soils of the southeast of Buenos Aires Province, Argentina. Atrazine rates of 0, 0.58, 1.16 and 2.32 mug g-1 of active ingredient (a.i.), metribuzin rates of 0, 0.14, 0.28 and 0.56 mug g-1 of a.i., and simazine rates of 0, 0.72, 1.45 and 2.9 mug g-1 of a.i. dry soil weight were applied to pots containing soils from Balcarce and San Cayetano sites. Organic matter (OM) content and pH of Balcarce soil were 5.5% and 5.8%, while for San Cayetano soil were 2.9% and 6.7%, respectively. Relative dry weight (RDW) of oat shoots was calculated as percentage of control. Considering a 20% RDW reduction of oat shoots, persistences of recommended rates for the region were: atrazine (1.16 mug g-1 of a.i.), 78 and 130 days after treatment (DAT) for Balcarce and San Cayetano soil, respectively; metribuzin (0.28 mug-1 of a.i.), 63 and 77 DAT for Balcarce and San Cayetano soil, respectively; simazine (1.45 mug g-1 of a.i.), 81 and 156 DAT for Balcarce and San Cayetano soil, respectively. Results show that persistence of atrazine, metribuzin and simazine in soil increased with high rates, low OM content and high pH.
Resumo:
Cet article présente les résultats de la revue systématique: Singh M, Das RR. Zinc for the common cold. Cochrane Database of Systematic Reviews 2011, Issue 2, Art. No.: CD001364. DOI: 10.1002/14651858.CD001364.pub3. PMID: 21328251.
Resumo:
Cet article présente les résultats de la revue systématique: Yang M, Yan Y, Yin X, et al. Chest physiotherapy for pneumonia in adults. Cochrane Database of Systematic Reviews 2010, Issue 2. Art. No.: CD006338. DOI: 10.1002/14651858.CD006338.pub2. PMID: 20166082.
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"Ces traductions en vers rythmés et rimés de l'Intermezzo lyrique de Heine tiennent du tour de force, ou plutôt du défi relevé avec élégance. L'ambition de surmonter ce qui semble insurmontable n'est pas la raison principale du choix qu'a fait ici le traducteur : ce choix s'est imposé comme une nécessité. Ou pour reprendre sa formule qui n'est paradoxale qu'à une lecture superficielle : le vers rythmé et rimé était 'possible parce que nécessaire". Georges Starobinski
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Virgin queens of the fire ant,Solenopsis invicta Buren, that were removed from the influence of the inhibitory queen pheromone, dealated more readily in the presence of workers than in their absence. During 72 hours after disinhibition, a significantly greater number of overwintered virgin queens than spring-reared virgin queens dealated when they were isolated, but the numbers that dealated in the presence of workers were very similar. Some sexually immature virgin queens dealated after disinhibition. Virgin dealates were found to be capable of preventing other virgin queens from dealating. The various factors that influence dealation by virgin queens were used to develop a bioassay for the inhibitory queen pheromone ofS. invicta. Lorsque des reines vierges de la fourmi de feu sont soustraites à l'influence de la phéromone inhibitrice produite par la reine, elles perdent leurs ailes plus facilement en présence d'ouvrières qu'en leur absence. Lorsqu'elles sont isolées pendant 72 heures après la levée de l'inhibition, un nombre significativement plus grand de reines vierges ayant hiverné perdent leurs ailes, par rapport aux reines vierges élevées au printemps. Toutefois, les nombres d'individus perdant leurs ailes en présence d'ouvrières sont similaires. Après désinhibition, quelques reines vierges immatures perdent leurs ailes. Les sexués vierges désailés sont capables de prévenir la perte des ailes chez d'autres sexués vierges. Les divers facteurs influençant la déalation chez les reines vierges ont été utilisés afin de développer un essai biologique pour la phéromone inhibitrice produite par la reine deS. invicta.
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1. Accumulating evidence indicates that plant resistance against above-ground herbivores can be affected by the presence of arbuscular mycorrhizal fungi (AMF) in association with the host plant. Little is known, however, about how AMF composition can influence herbivore choice to feed on a particular plant. 2. Unravelling the preference-performance hypothesis in a multitrophic context is needed to expand our knowledge of complex multitrophic interactions in natural systems. If given mycorrhizal fungal genotypes increase attractiveness for a herbivore (reduced plant resistance), then the benefits of increased unpalatability provided by the mycorrhizal fungi (increased plant resistance) might be outweighed by the increased herbivore recruitment. 3. This was addressed by designing three experiments to test the effects of different AMF genotypes, inoculated either alone or in combination, to measure intraspecific AMF effects on plant resistance and insect herbivore preference. Using strawberry (Fragaria vesca L.) plants that were colonised by eight different combinations of Rhizophagus irregularis isolates, we measured effects on plant growth, insect growth and survival, as well as feeding preferences of a generalist herbivore caterpillar (Spodoptera littoralis Boisduval). 4. Overall, it was found that: (i) AMF influenced plant resistance in an AMF genotype-specific manner; (ii) some AMF inoculations decreased insect performance; (iii) insects preferentially chose to feed more on leaves originating from non-mycorrhizal plants; but also that (iv) in a whole plant bioassay, insects preferentially chose the biggest plant, regardless of their mycorrhizal status. 5. Therefore, AMF-mediated trade-offs between growth and resistance against herbivores have been shown. Such trade-offs, particularly driven by plant attractiveness to herbivores, buffer the positive effects of the mycorrhizal symbiosis on enhanced plant growth.