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41.
42.
David M. Anderson Richard H. Scheller James W. Posakony Linda B. McAllister Steven G. Trabert Clifford Beall Roy J. Britten Eric H. Davidson 《Journal of molecular biology》1981,145(1):5-28
Three repetitive sequence families from the sea urchin genome were studied, each defined by homology with a specific cloned probe one to a few hundred nucleotides long. Recombinant λ-sea urchin DNA libraries were screened with these probes, and individual recombinants were selected that include genomic members of these families. Restriction mapping, gel blot, and kinetic analyses were carried out to determine the organization of each repeat family. Sequence elements belonging to the first of the three repeat families were found to be embedded in longer repeat sequences. These repeat sequences frequently occur in small clusters. Members of the second repeat family are also found in a long repetitive sequence environment, but these repeats usually occur singly in any given region of the DNA. The sequences of the third repeat are only 200 to 300 nucleotides long, and are generally terminated by single copy DNA, though a few examples were found associated with other repeats. These three repeat sequence families constitute sets of homologous sequence elements that relate distant regions of the DNA. 相似文献
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44.
E. Molina Grima J. A. Sánchez Pérez F. García Camacho F. G. Acién Fernández J. M. Fernández Sevilla F. Valdés Sanz 《Biotechnology letters》1994,16(10):1035-1040
Summary Eicosapentaenoic acid (EPA) volumetric productivity from an outdoor chemostat culture ofPhaeodactylum tricornutum UTEX 640 in a 50-l tubular photobioreactor varies with dilution rate, reaching a maximum of 47.8 mg l–1 d–1 at D=0.36 d–1. Continuous culture at high dilution rates' is proposed as the most adequate operating mode to maximize polyunsaturated fatty acid production. 相似文献
45.
M Sj?lund J Nilsson L Palmberg J Thyberg 《Differentiation; research in biological diversity》1984,27(2):158-162
The effects of prostaglandin E1 (PGE1) on the phenotypic state of enzymatically isolated arterial smooth-muscle cells in primary culture were studied by transmission electron microscopy, thymidine autoradiography, and cell counting. Early in culture (day 0-2), PGE1 stimulated conversion of the cells from contractile (less euchromatic nucleus and cytoplasm dominated by myofilament bundles) to synthetic state (more euchromatic nucleus and cytoplasm dominated by cisternae of rough endoplasmic reticulum and a large Golgi complex). The rate of entrance of the cells into DNA synthesis and mitosis was also increased at this time. Later on (day 3-6), when the majority of the cells had entered synthetic state, PGE1 inhibited DNA synthesis and cellular proliferation. These observations indicate that the effect of prostaglandins on arterial smooth muscle is dual in nature and dependent on the state of differentiation of the cells. 相似文献
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Steven J. Tucker David McClelland Kristina Sep?i? Roderick H. Scott 《生物化学与生物物理学报:生物膜》2003,1614(2):171-181
The ability of two alkyl pyridinium sponge toxin preparations (poly-APS and halitoxin) to form transient pores/lesions in cell membranes and allow transfection of plasmid cDNA have been investigated using HEK 293 cells. Poly-APS and halitoxin preparations caused a collapse in membrane potential, reductions in input resistance and increased Ca2+ permeability. At least partial recovery was observed after poly-APS application but recovery was more rarely seen with halitoxin. The transfection with plasmid cDNAs for an enhanced green fluorescent protein (EGFP) and human tumour necrosis factor receptor 2 (TNFR2) was assessed for both toxin preparations and compared with lipofectamine. Stable transfection was achieved with poly-APS although it was less efficient than lipofectamine. These results show that viable cells transfected with alien cDNA can be obtained using novel transient pore-forming alkyl pyridinium sponge toxins and a simple pre-incubation protocol. This provides the first proof of principle that pore-forming alkyl pyridinium compounds can be used to deliver cDNA to the intracellular environment without permanently compromising the plasma membrane. 相似文献
48.
V V Snitinski? 《Zhurnal evoliutsionno? biokhimii i fiziologii》1989,25(5):583-588
[2-14C] leucine, [1-14C] alanine, [1-14C] glucose, [1-14C] lactate and [1-14C] pyruvate utilization in the protein synthesis has been studied in vivo at early stages of postnatal development of piglets. It has been established, that during the first 24 hours after birth the protein synthesis intensity, judging by [2-14C] leucine incorporation, in liver, skeletal muscle, duodenal wall and subcutaneous tissue of piglets increases 5, 7, 6.5 and 2.1 times respectively. At the age of 1-2 h the radioactive carbon incorporation from [1-14C] glucose into the brain proteins is more pronounced than into the proteins of liver and skeletal muscle. During the first days of life the intensity of the label incorporation from [1-14C] glucose into liver and skeletal muscle proteins of piglets is enhanced, whereas in brain it remains at the same level. The degree of 14C carbon incorporation from [1-14C]-alanine, [1-14C] pyruvate and [1-14C] lactate into the liver and skeletal muscle proteins of 5-days-old piglets is approximately the same, 14C substrates of protein synthesis in brain and subcutaneous adipose tissue having some peculiarities. 相似文献
49.
50.
A Ba?sset J Cotonat P Montastruc 《Comptes rendus des séances de la Société de biologie et de ses filiales》1975,169(2):444-448
The authors have studied in the dog--normal or diabetic insipidus after hypothalamic lesion--submitted to oral ingestion of ethanol the effects of a few antidiuretic drug: chlorpropamid, atromid-S, carbamazepin and carisoprodol. The carisoprodol only can reduce the diuresis and the drinking provoked by ethanol. 相似文献