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131.
Manipulation of DET1 expression in tomato results in photomorphogenic phenotypes caused by post-transcriptional gene silencing 总被引:4,自引:0,他引:4
132.
Diterpenes from the leaves of Croton zambesicus 总被引:1,自引:0,他引:1
Block S Baccelli C Tinant B Van Meervelt L Rozenberg R Habib Jiwan JL Llabrès G De Pauw-Gillet MC Quetin-Leclercq J 《Phytochemistry》2004,65(8):1165-1171
Two new trachylobane- and one isopimarane-type diterpenoids: ent-18-hydroxy-trachyloban-3-one; ent-trachyloban-3-one; isopimara-7,15-dien-3beta-ol, were isolated from the leaves of Croton zambesicus, together with trans-phytol, beta-sitosterol, alpha-amyrin and stigmasterol. The structures were determined by extensive NMR techniques and X-ray analysis. The cytotoxicity of these compounds has been evaluated on cancer and non-cancer cell-lines. 相似文献
133.
Pierleoni R Buffalini M Vallorani L Guidi C Zeppa S Sacconi C Pucci P Amoresano A Casbarra A Stocchi V 《Phytochemistry》2004,65(7):813-820
The formation of the fruit body represents the final phase of the ectomycorrhizal fungus T. borchii life cycle. Very little is known concerning the molecular and biochemical processes involved in the fructification phase. 2-DE maps of unripe and ripe ascocarps revealed different protein expression levels and the comparison of the electropherograms led to the identification of specific proteins for each developmental phase. Associating micropreparative 2-DE to microchemical approaches, such as N-terminal sequencing and 2-D gel-electrophoresis mass-spectrometry, proteins playing pivotal roles in truffle physiology were identified. 相似文献
134.
Capri M Scarcella E Fumelli C Bianchi E Salvioli S Mesirca P Agostini C Antolini A Schiavoni A Castellani G Bersani F Franceschi C 《Radiation research》2004,162(2):211-218
The aim of this study was to investigate the nonthermal effects of radiofrequency (RF) fields on human immune cells exposed to a Global System for Mobile Communication (GSM) signal generated by a commercial cellular phone and by a sinusoidal non-modulated signal. To assess whether mobile phone RF-field exposure affects human immune cell functions, peripheral blood mononuclear cells (PBMCs) from healthy donors were exposed in vitro to a 900 MHz GSM or continuous-wave (CW) RF field 1 h/day for 3 days in a transverse electromagnetic mode (TEM) cell system (70-76 mW/kg average specific absorption rate, SAR). The cells were cultured for 48 or 72 h, and the following end points were studied: (1) mitogen-induced proliferation; (2) cell cycle progression; (3) spontaneous and 2-deoxy-D-ribose (dRib)-induced apoptosis; (4) mitochondrial membrane potential modifications during spontaneous and dRib-induced-apoptosis. Data obtained from cells exposed to a GSM-modulated RF field showed a slight decrease in cell proliferation when PBMCs were stimulated with the lowest mitogen concentration and a slight increase in the number of cells with altered distribution of phosphatidylserine across the membrane. On the other hand, cell cycle phases, mitochondrial membrane potential and susceptibility to apoptosis were found to be unaffected by the RF field. When cells were exposed to a CW RF field, no significant modifications were observed in comparison with sham-exposed cells for all the end points investigated. 相似文献
135.
Brasun J Gabbiani C Ginanneschi M Messori L Orfei M Swiatek-Kozlowska J 《Journal of inorganic biochemistry》2004,98(12):2016-2021
The new cyclic tetrapeptide c(HGHK) was synthesised in the solid phase and its complexes with copper(II) were studied in aqueous solution at various pH values by means of potentiometric and spectroscopic methods (UV, EPR, CD). Six mononuclear coordination species were clearly identified within the pH range 3-11. Spectroscopic data strongly suggest sequential formation of N, 2N, 3N and 4N equatorial donor sets around the copper(II) centre from the lowest to the highest pH, involving both imidazole nitrogens and amide nitrogens. A detailed comparison with the copper(II) binding properties of HGHG and Ac-HGHG ligands is also reported. 相似文献
136.
The deletion of the succinate dehydrogenase gene KlSDH1 in Kluyveromyces lactis does not lead to respiratory deficiency 下载免费PDF全文
We have isolated a Kluyveromyces lactis mutant unable to grow on all respiratory carbon sources with the exception of lactate. Functional complementation of this mutant led to the isolation of KlSDH1, the gene encoding the flavoprotein subunit of the succinate dehydrogenase (SDH) complex, which is essential for the aerobic utilization of carbon sources. Despite the high sequence conservation of the SDH genes in Saccharomyces cerevisiae and K. lactis, they do not have the same relevance in the metabolism of the two yeasts. In fact, unlike SDH1, KlSDH1 was highly expressed under both fermentative and nonfermentative conditions. In addition to this, but in contrast with S. cerevisiae, K. lactis strains lacking KlSDH1 were still able to grow in the presence of lactate. In these mutants, oxygen consumption was one-eighth that of the wild type in the presence of lactate and was normal with glucose and ethanol, indicating that the respiratory chain was fully functional. Northern analysis suggested that alternative pathway(s), which involves pyruvate decarboxylase and the glyoxylate cycle, could overcome the absence of SDH and allow (i) lactate utilization and (ii) the accumulation of succinate instead of ethanol during growth on glucose. 相似文献
137.
Messori L Marcon G Cinellu MA Coronnello M Mini E Gabbiani C Orioli P 《Bioorganic & medicinal chemistry》2004,12(23):6039-6043
The solution behaviour of some novel organogold(III) compounds was investigated, and their cytotoxic properties evaluated against a few human tumour cell lines (A2780/S, A2780/R, MCF7, HT29 and A549). Specifically, the following compounds were considered: [Au(bipy(dmb)-H)(2,6-xylidine-H)][PF(6)] (AuXyl) and [Au(bipy(dmb)-H)(p-toluidine-H)][PF(6)] (AuTol) (in which bipy(dmb)=6-(1,1-dimethylbenzyl)-2,2'-bipyridine), [Au(py(dmb)-H)(AcO)(2)] (AuPyAcO) (in which py(dmb)=2-(1,1-dimethylbenzyl)-pyridine) and [Au(pz(Ph)-H)Cl(3)]K (AuPzCl) (in which pz(Ph)=1-phenylpyrazole). The solution chemistry of these compounds, under physiological-like conditions, was investigated through UV-vis absorption and (1)H NMR spectroscopies. Significant cytotoxic effects in vitro were observed in selected cases. 相似文献
138.
Chemical ligation approaches facilitate the chemoselective assembly of unprotected peptides in aqueous solution. Here, two photolabile auxiliaries are described that enlarge the applicability of native chemical ligation to non-cysteine targets. The auxiliaries, designed to allow reaction with thioester peptides, generate an amide bond between the two initial fragments. The o-nitrobenzyl tertiary benzylamide that is formed at the ligation junction can be transformed into a native amide group under mild photolysis conditions. The veratryl auxiliary was found to be excessively labile during peptide purification and ligation. However, the auxiliary based on the o-nitrobenzyl group shows all the necessary properties for a general application in routine peptide and protein synthesis. In addition, the auxiliary linked to the N-terminus can be efficiently photolyzed, suggesting a new approach for the generation of photocaged amines. Synthesis, solid phase introduction onto peptide chains, ligation properties and photolysis in water are described, and a careful study of compatibility of the method with potentially fragile peptide side chains is reported. 相似文献
139.
Loredana R Barbara D Annamaria L Stefania T Maria MC Silvana F Piero A Marina P 《Molecular reproduction and development》2003,66(1):54-59
In the present paper we investigated the role played by apoptosis during oogenesis in the cartilaginous fish Torpedo marmorata. TEM, TUNEL and immunohistochemical techniques were employed to specifically reveal morphological and biochemical hallmarks of apoptosis in specimens from birth to sexual maturity. Data obtained demonstrate that apoptosis occurs in prefollicular oocyte selection, in maintaining the homeostasis of granulosa in healthy growing oocyte and in resorbing atretic follicles. In this respect, the involvement of apoptosis in Torpedo marmorata oogenesis closely parallels that found in mammals, thus confirming that strategies of germ cell selection among vertebrates have been evolutionarily preserved. 相似文献
140.