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41.
L A Marco R Pendleton T F Reed T E Brigham L D Aldes R B Chronister 《Comp. Biochem. Physiol. C, Comp. Pharmacol. Toxicol.》1989,94(1):29-33
1. The purpose of this study was to demonstrate that ketamine anesthesia (100 mg/kg) induces tongue protrusions (P) in addition to retrusions (R) and swallows (S) in adult rats. 2. These linguo-pharyngeal events occur alone or combined in various sequential patterns. 3. The SPR sequence is not the predominant pattern in all preparations suggesting profound disruption of physiological linkages by ketamine. 4. Haloperidol administration suppresses these events for 1-120 min depending on the dose (0.75-2.5 mg/kg). 5. Swallows are the least vulnerable to haloperidol. 6. This and previous findings provide further evidence that ketamine induced linguo-pharyngeal activity can serve as a model for acute or tardive dyskinesia better than stereotypies. 相似文献
42.
Verticillium balanoides mycelial growth was stimulated on solid corn meal agar (1.7 %) and in liquid corn meal broth (0.2 %) upon the addition of phospholipids at various concentrations. Sporulation differed with phospholipid products and was highest in pure corn meal. Drechmeria coniospora mycelial growth increased upon addition of phospholipids at all concentrations in solid or liquid culture. Sporulation increased at high concentration (1000 ppm) and decreased at low concentration (100 ppm) of phospholipids in the medium. For both fungi, infectivity of conidia produced in liquid culture decreased when compared to conidia from parasitized nematodes. Addition of phospholipids partly restored this effect. Harposporium anguillulae mycelial growth and sporulation was not affected by addition of phospholipids to solid or liquid corn meal medium. 相似文献
43.
Mechanisms by which EGF receptor and TGF alpha contribute to malignant transformation 总被引:2,自引:0,他引:2
E Di Marco J H Pierce S A Aaronson P P Di Fiore 《Natural immunity and cell growth regulation》1990,9(3):209-221
Alterations affecting the epidermal growth factor/transforming growth factor alpha-responsive mitogenic pathway are frequently detected in malignancies. In particular, the epidermal growth factor receptor has been found overexpressed in a number of human tumors. Production and secretion of transforming growth factor type alpha has also been shown in several tumor cells but not in their normal counterparts. In this review we describe the establishment of in vitro model systems to study the transforming potential of these molecules and summarize our current understanding of the mechanisms involved in transformation by genes encoding a growth factor and a growth factor receptor. 相似文献
44.
45.
Raffaella Scardigli Silvia Soddu Rita Falcioni Marco Crescenzi Letizia Cimino Ada Sacchi 《Experimental cell research》1996,227(2):223
Integrin β4subunit is present in association with α6chain on both normal and transformed epithelial cells. Recently α6β4heterodimer was found on the endothelium of medium-sized blood vessels and on immature thymocytes. In this report we show, by Northern blotting, indirect immunofluorescence, immunoprecipitation, and Western blotting, that β4subunit is expressed also on cells of mesenchymal origin such as fibroblasts, myoblasts, and myotubes. Increased expression of α6β4has been related to the aggressive metastatic phenotype of human and murine carcinomas. The transforming growth factor β1(TGF-β1) has been found to modulate the expression of several integrins and intracellular matrix proteins, as well as to stimulate cell invasion and metastatic potential. To evaluate whether α6β4expression is modulated by TGF-β1, we transfected 3T3 fibroblasts with an expression vector carrying the human TGF-β1cDNA driven by the SV40 early promoter. We observed by indirect immunofluorescence a modification in the subcellular distribution of β4subunit, which acquires a perinuclear localization. This finding suggests this integrin subunit correlates with the cytoskeletal reorganization induced by TGF-β1. 相似文献
46.
Nonlinearity in normal human EEG: cycles,temporal asymmetry,nonstationarity and randomness,not chaos 总被引:7,自引:1,他引:6
Milan Paluš 《Biological cybernetics》1996,75(5):389-396
Two-hour vigilance and sleep electroencephalogram (EEG) recordings from five healthy volunteers were analyzed using a method
for identifying nonlinearity and chaos which combines the redundancy–linear redundancy approach with the surrogate data technique.
A nonlinear component in the EEG was detected, however, inconsistent with the hypothesis of low-dimensional chaos. A possibility
that a temporally asymmetric process may underlie or influence the EEG dynamics was indicated. A process that merges nonstationary
nonlinear deterministic oscillations with randomness is proposed for an explanation of observed properties of the analyzed
EEG signals. Taking these results into consideration, the use of dimensional and related chaos-based algorithms in quantitative
EEG analysis is critically discussed.
Received: 25 September 1994 / Accepted in revised form: 10 July 1996 相似文献
47.
Synopsis Morphological changes in the sea bass, Dicentrarchus labrax (Perciformes: Moronidae), were investigated after an experimental acclimation trial to freshwater. The sea bass is an euryhaline species occurring in the Mediterranean and west Atlantic from 30° N to 55° N. Part of the offspring of a pool of breeders was acclimated to freshwater at 9 months of age while maintaining the original stock in marine water. The effect of acclimation to freshwater over the entire form of the fish was studied through geometric morphometrics (shape coordinates). Changes in the form were shown graphically as landmark displacements though age classes 7,12, 15, 19 and 24 months and were discussed in the light of integrated growth. A significantly faster growth in freshwater was detected. Shape coordinates analyzed through multivariate statistics show that significant differences in shape arise after acclimation to freshwater. Moreover, the uniform component of shape change reveals a major effect of stretching or compression perpendicular to the body axis which is common and conservative in both trials. Differences are discussed in terms of selection and ecophenotypism. 相似文献
48.
Continuous pollen monitoring of an urban network consisting of three stations has been undertaken for a period of 2 years
in Perugia, central Italy. The aim has been to establish whether the Perugia pollen trap, active since 1983, is still representative
of the area following recent urbanisation. Quantitative differences were found between the stations, reflecting different
vegetational areas, but only slight differences were detected in relation to the timing of the principal period of pollination.
Therefore, although individual pollen traps are necessary to characterize fully the different areas, one trap is sufficient
to determine the key allergenic thresholds in the studied area. 相似文献
49.
Continuous pollen monitoring of an urban network consisting of three stations has been undertaken for a period of 2 years in Perugia, central Italy. The aim has been to establish whether the Perugia pollen trap, active since 1983, is still representative of the area following recent urbanisation. Quantitative differences were found between the stations, reflecting different vegetational areas, but only slight differences were detected in relation to the timing of the principal period of pollination. Therefore, although individual pollen traps are necessary to characterize fully the different areas, one trap is sufficient to determine the key allergenic thresholds in the studied area. 相似文献
50.
J. L. Marco L. A. Bataus F. F. Valência C. J. Ulhoa S. Astolfi-Filho C. R. Felix 《Applied microbiology and biotechnology》1996,44(6):746-752
ABacillus subtilis amylase gene was inserted into a plasmid which transferred toEscherichia coli. During cloning, a 3 region encoding 171 carboxyterminal amino acids was replaced by a nucleotide sequence that encoded 33 amino acid residues not present in the indigenous protein. The transformed cells produced substantial amylolytic activity. The active protein was purified to apparent homogeneity. Its molecular mass (48 kDa), as estimated in sodium dodecyl sulfate/polyacrylamide gel electrophoresis, was lower than the molecular mass values calculated from the derived amino acid sequences of theB. subtilis complete -amylase (57.7 kDa) and the truncated protein (54.1 kDa). This truncated enzyme form hydrolysed starch with aK
m of 3.845 mg/ml. Activity was optimal at pH 6.5 and 50°C, and the purified enzyme was stable at temperatures up to 50°C. While Hg2+, Fe3+ and Al3+ were effective in inhibiting the truncated enzyme Mn2+ and Co2+ considerably enhanced the activity. 相似文献