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101.
Andrey V. Kulikov Alexander S. Vdovin Boris Zhivotovsky Vladimir Gogvadze 《Cellular and molecular life sciences : CMLS》2014,71(12):2325-2333
Rapidly proliferating tumor cells easily become hypoxic. This results in acquired stability towards treatment with anticancer drugs. Here, we show that cells grown at 0.1 % oxygen are more resistant towards treatment with the conventionally used anticancer drugs doxorubicin and cisplatin. The stimulation of apoptosis, as assessed by the number of cells in the SubG1 fraction of the cell cycle, release of cytochrome c into the cytosol, activation of caspase-3, and cleavage of PARP, was markedly suppressed under low oxygen content or when hypoxia was mimicked by deferoxamine. Hypoxia or deferoxamine treatment was accompanied by stabilization of the hypoxia-inducible factor (HIF-1). The downregulation of HIF-1 using siRNA technique restored cell sensitivity to treatment under hypoxic conditions to the levels detected under normoxic conditions. In contrast to cisplatin or doxorubicin, α-tocopheryl succinate (α-TOS), a compound that targets mitochondria, stimulated cell death irrespective of the oxygen concentration. Moreover, under hypoxic condition cell death induced by α-TOS was even enhanced. Thus, α-TOS can successfully overcome resistance to treatment caused by hypoxia, which makes α-TOS an attractive candidate for antitumor therapy via mitochondrial targeting. 相似文献
102.
Lígia O. Martins Paulo Durão Vânia Brissos Peter F. Lindley 《Cellular and molecular life sciences : CMLS》2015,72(5):911-922
The ubiquitous members of the multicopper oxidase family of enzymes oxidize a range of aromatic substrates such as polyphenols, methoxy-substituted phenols, amines and inorganic compounds, concomitantly with the reduction of molecular dioxygen to water. This family of enzymes can be broadly divided into two functional classes: metalloxidases and laccases. Several prokaryotic metalloxidases have been described in the last decade showing a robust activity towards metals, such as Cu(I), Fe(II) or Mn(II) and have been implicated in the metal metabolism of the corresponding microorganisms. Many laccases, with a superior efficiency for oxidation of organic compounds when compared with metals, have also been identified and characterized from prokaryotes, playing roles that more closely conform to those of intermediary metabolism. This review aims to present an update of current knowledge on prokaryotic multicopper oxidases, with a special emphasis on laccases, anticipating their enormous potential for industrial and environmental applications. 相似文献
103.
104.
F. Weygand A. Wacker V. Schmied-Kowarzik 《Cellular and molecular life sciences : CMLS》1948,4(11):427-428
Summary By condensing 2:4:5-triamino-6-hydroxy-pyrimidine with dihydroxyacetone (diacetate), diaminoacetone or acetone-1,3-di (p-formylaminobenzoic acid) not the expected 8- or 9-oxymethyl resp. -aminomethyl-pteridines but 8-or 9-methyl-pteridines were obtained. With p-tolyl-d-isoglucosamine not a tetrahydroxybutyl-pteridine but a trihydroxybutyl-pteridine was formed. For an explanation of these results it is supposed that from the dihydro-pteridines formed at first by intramolecular splitting off of H2O or R·NH2 aromatization takes place. 相似文献
105.
Summary Acetone and alcohol extracts of the posterior salivary glands ofOctopus vulgaris, Eledone moschata andEledone Aldrovandi contain a principle which strongly reduces the diuresis in hydrated rats.The antidiuretic principle is absent in all otherOctopus tissues as well as in the salivary glands ofOctopus macropus.It shows a high termostability and is strongly adsorbed by animal charcoal at any reaction.The salivary antidiuretic substance is not identical with the posterior pituitary principle nor with the other active substances found in the salivary glands of Octopoda.The injection of salivary extracts satisfactorily reduces polyuria and polydipsia in human diabetes insipidus.
Le presenti ricerche sono state in parte sovvenzionate da un contributo straordinario del Consiglio Nazionale delle Ricerche. 相似文献
Le presenti ricerche sono state in parte sovvenzionate da un contributo straordinario del Consiglio Nazionale delle Ricerche. 相似文献
106.
107.
Summary By the aid of a synthetic antihistaminic drug (dimethylamino-ethyl-benzylaniline) the Authors succeeded in demonstrating that the purgative action of various drastic agents(Oleum Ricini, Elaterium, Colocynthis, Globularia Alypum) is, at least partially, to be accounted to a release of histamine.Antihistaminic drugs are indeed able, in quantities by themselves ineffective on the alimentary canal, to delay or even to abolish the purgative action of very large doses of the examined drastics. 相似文献
108.
Ohne Zusammenfassung9. Mitt. Untersuchungen über Organextrakte; 8. Mitt. vgl. Helv. chim. acta28 im Druck. 相似文献
109.
Proteomic studies have yielded detailed lists of the proteins present in a cell. Comparatively little is known, however, about how these proteins interact and are spatially arranged within the 'functional modules' of the cell: that is, the 'molecular sociology' of the cell. This gap is now being bridged by using emerging experimental techniques, such as mass spectrometry of complexes and single-particle cryo-electron microscopy, to complement traditional biochemical and biophysical methods. With the development of integrative computational methods to exploit the data obtained, such hybrid approaches will uncover the molecular architectures, and perhaps even atomic models, of many protein complexes. With these structures in hand, researchers will be poised to use cryo-electron tomography to view protein complexes in action within cells, providing unprecedented insights into protein-interaction networks. 相似文献
110.
Piccioni G Drossart P Sanchez-Lavega A Hueso R Taylor FW Wilson CF Grassi D Zasova L Moriconi M Adriani A Lebonnois S Coradini A Bézard B Angrilli F Arnold G Baines KH Bellucci G Benkhoff J Bibring JP Blanco A Blecka MI Carlson RW Di Lellis A Encrenaz T Erard S Fonti S Formisano V Fouchet T Garcia R Haus R Helbert J Ignatiev NI Irwin PG Langevin Y Lopez-Valverde MA Luz D Marinangeli L Orofino V Rodin AV Roos-Serote MC Saggin B Stam DM Titov D Visconti G 《Nature》2007,450(7170):637-640
Venus has no seasons, slow rotation and a very massive atmosphere, which is mainly carbon dioxide with clouds primarily of sulphuric acid droplets. Infrared observations by previous missions to Venus revealed a bright 'dipole' feature surrounded by a cold 'collar' at its north pole. The polar dipole is a 'double-eye' feature at the centre of a vast vortex that rotates around the pole, and is possibly associated with rapid downwelling. The polar cold collar is a wide, shallow river of cold air that circulates around the polar vortex. One outstanding question has been whether the global circulation was symmetric, such that a dipole feature existed at the south pole. Here we report observations of Venus' south-polar region, where we have seen clouds with morphology much like those around the north pole, but rotating somewhat faster than the northern dipole. The vortex may extend down to the lower cloud layers that lie at about 50 km height and perhaps deeper. The spectroscopic properties of the clouds around the south pole are compatible with a sulphuric acid composition. 相似文献