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911.
912.
Armelle Baeza-Squiban Emmanuelle Boisvieux-Ulrich Catherine Guilianelli Odile Houcine Gérard Geraud Christiane Guennou Francelyne Marano 《In vitro cellular & developmental biology. Animal》1994,30(1):56-67
Summary The differentiation of tracheal epithelial cells in primary culture was investigated according to the nature of the extracellular
matrix used. Cultures obtained by the explant technique were realized on a type I collagen substratum either as a thin, dried
coating or as a thick, hydrated gel supplemented with culture medium and serum. These two types of substratum induced distinct
cell morphology and cytokeratin expression in the explant derived cells. Where cells are less proliferating (from Day 7 to
10 of culture), differentiation was evaluated by morphologic ultrastructural observations, immunocytochemical detection of
cytokeratins, and determination of cytokeratin pattern by biochemical analysis.
The epithelium obtained on gel was multilayered, with small, round basal cells under large, flattened upper cells. The determination
of the keratin pattern expressed by cells grown on gel revealed an expression of keratin 13, already considered as a specific
marker of squamous metaplasia, that diminished with retinoic acid treatment. Present results demonstrated by confocal microscopy
that K13-positive cells were large upper cells with a dense keratin network, whereas lower cells were positively stained with
a specific monoclonal antibody to basal cells (KB37). Moreover, keratin neosynthesis analysis pointed out a higher expression
of K6, a marker of hyperproliferation, on gel than on coating. All these data suggest a differentiation of rabbit tracheal
epithelial cells grown on gel toward squamous metaplasia. By contrast, the epithelium observed on coating is nearly a monolayer
of very large and spread out cells. No K13-positive cells were observed, but an increase in the synthesis of simple epithelium
marker (K18) was detected. These two substrata, similar in composition and different in structure, induce separate differentiation
and appear as good tools to explore the mechanisms of differentiation of epithelial tracheal cells. 相似文献
913.
Luciano A Rigano María R Marano Atilio P Castagnaro Alexandre Morais Do Amaral Adrian A Vojnov 《BMC microbiology》2010,10(1):176
Background
Citrus Bacterial Canker (CBC) is a major, highly contagious disease of citrus plants present in many countries in Asia, Africa and America, but not in the Mediterranean area. There are three types of Citrus Bacterial Canker, named A, B, and C that have different genotypes and posses variation in host range within citrus species. The causative agent for type A CBC is Xanthomonas citri subsp. citri, while Xanthomonas fuscans subsp. aurantifolii, strain B causes type B CBC and Xanthomonas fuscans subsp. aurantifolii strain C causes CBC type C. The early and accurate identification of those bacteria is essential for the protection of the citrus industry. Detection methods based on bacterial isolation, antibodies or polymerase chain reaction (PCR) have been developed previously; however, these approaches may be time consuming, laborious and, in the case of PCR, it requires expensive laboratory equipment. Loop-mediated isothermal amplification (LAMP), which is a novel isothermal DNA amplification technique, is sensitive, specific, fast and requires no specialized laboratory equipment. 相似文献914.
T A Kopitnik H H Kaufman R W Haid G D Marano G R Nugent 《Applied neurophysiology》1987,50(1-6):188-194
A 'spherical coordinate system' has been developed to allow either stereotactic biopsy of two intracranial lesions using a single predetermined trajectory or biopsy of a single lesion through an existing burr hole. By means of the Gildenberg technique, the CT coordinates of the targets (or target and burr hole) are obtained. These are employed in three simple trigonometric equations to give three coordinates-two angles for the probe carrier (theta and alpha) and the radius (T) of a sphere, defined by one target as the center and the other target on the surface. These can be utilized in the Todd-Wells stereotactic frame. This system was evaluated using hollow skulls and crossed 30-gauge wire for phantom targets. The system was tried on ten different target combinations, and eight successful trajectories were obtained to within 3 mm. Two target combinations were inaccessible because of technical limitations of the Todd-Wells frame. This 'spherical coordinate system' can decrease the time to localize multiple targets as well as minimize the number of passes. 相似文献