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991.
Miller AC Cohen S Stewart M Rivas R Lison P 《Radiation and environmental biophysics》2011,50(4):585-596
The histone deacetylase inhibitor (HDAC), phenylbutyrate (PB), is a novel anti-tumor agent. Studies have demonstrated that
HDAC inhibitors can suppress cutaneous radiation syndrome and stimulate hematopoiesis. The objective of this study was to
test the ability of PB treatment to protect against acute gamma-radiation-induced lethality in the DBA/2 mouse model. A 30-day
radiation lethality study was used to assess radioprotective capability of PB. Mechanisms were evaluated using western blots,
flow cytometry, and the single-cell gel electrophoresis assay. Western blot studies showed that PB treatment acetylated histones
in vivo. For radiation protection studies, prophylactic administration of PB (24 h preradiation; 1–50 mg/kg) provided radioprotection
against gamma radiation (8–9.5 Gy) and PB demonstrated a DRF of 1.31 (P = 0.001; 95% confidence interval: 1.27, 1.36). When PB (10 mg/kg) was administered post-radiation (4 h), it also provided
significant radioprotection at 8.0 Gy radiation (P = 0.022). PB treatment before radiation was associated with significant elevations in neutrophils and platelets following
radiation. Results from single-cell gel electrophoresis of peripheral blood leukocytes demonstrated that PB treatment before
radiation can attenuate DNA damage and inhibit radiation-induced apoptosis. These results indicate that an HDAC inhibitor
like PB has potential as a radiation protector and that mechanisms of action include attenuation of DNA damage and inhibition
of apoptosis. 相似文献
992.
Trujillo-Ferrara J Campos-Rodríguez R Lara-Padilla E Ramírez-Rosales D Correa Basurto J Miliar Garcia A Reyna Garfias H Zamorano Ulloa R Rosales-Hernández MC 《Bioscience reports》2011,31(4):273-282
It is well known that CR (caloric restriction) reduces oxidative damage to proteins, lipids and DNA, although the underlying mechanism is unclear. However, information concerning the effect of CR on the host response to infection is sparse. In this study, 6-month-old mice that were fed AL (ad libitum) or with a CR diet were infected with Salmonella serovar Typhimurium. EPR (electron paramagnetic resonance; also known as ESR (electron spin resonance)) was used to identify FRs (free radicals). These results were subsequently correlated with SOD (superoxide dismutase) catalytic activity, iNOS [inducible NOS (nitric oxide synthase) or NOSII] expression and NO (nitric oxide) content. EPR analysis of liver samples demonstrated that there was a higher quantity of FRs and iron-nitrosyl complex in infected mice provided with a CR diet as compared with those on an AL diet, indicating that CR was beneficial by increasing the host response to Salmonella Typhimurium. Furthermore, in infected mice on the CR diet, NOSII expression was higher, NO content was greater and spleen colonization was lower, compared with mice on the AL diet. No changes in SOD activity were detected, indicating that the NO produced participated more in the formation of iron-nitrosyl complexes than peroxynitrite. These results suggest that CR exerts a protective effect against Salmonella Typhimurium infection by increasing NO production. 相似文献
993.
994.
Pilar Pérez Aitor Alonso Gloria Zita Rosa Morcuende Rafael Martínez-Carrasco 《Plant Growth Regulation》2011,65(3):439-447
Increases in growth temperature have been observed to affect photosynthesis differently under long-term exposure to ambient-
and twice ambient-air CO2 concentrations. This study investigates the causes of this interaction in wheat (Triticum aestivum L.) grown in the field over two consecutive years under temperature gradient chambers in ambient (370 μmol mol−1) or elevated (700 μmol mol−1) atmospheric CO2 concentrations and at ambient or ambient +4°C temperatures, with either a low or a high nitrogen supply. The photosynthesis-internal
CO2 response curves and the activity, activation state, kcat and amount of Ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) were measured, as well as the soluble protein concentration
in flag leaves at ear emergence and 8–15 days after anthesis. A high nitrogen supply increased Vcmax, the Rubisco amount and activity and soluble protein contents, but did not significantly change the Rubisco kcat. Both elevated CO2 and above ambient temperatures had negative effects on Vcmax and Rubisco activity, but at elevated CO2, an increase in temperature did not decrease Vcmax or Rubisco activity in relation to ambient temperature. The amounts of Rubisco and soluble protein decreased with elevated
CO2 and temperature. The negative impact of elevated CO2 on Rubisco properties was somewhat counteracted at elevated temperatures by an increase in kcat. This effect can diminish the detrimental effects on photosynthesis of combined increases of CO2 and temperature. 相似文献
995.
Márquez-Martín B Sesmero R Quesada MA Pliego-Alfaro F Sánchez-Romero C 《Journal of plant physiology》2011,168(17):2028-2034
Application of transformation and other biotechnological tools in avocado (Persea americana Mill.) is hampered by difficulties in obtaining mature somatic embryos capable of germination at an acceptable rate. In this work, we evaluated the effect of different compounds affecting medium water relations on maturation of avocado somatic embryos. Culture media were characterized with respect to gel strength, water potential and osmotic potential. Improved production of mature somatic embryos was achieved with gelling agent concentrations higher than those considered standard. The osmotic agents such as sorbitol and PEG did not have positive effects on embryo maturation. The number of w-o mature somatic embryos per culture was positively correlated with medium gel strength. Gel strength was significantly affected by gelling agent type as well as by gelling agent and PEG concentration. Medium water potential was influenced by sorbitol concentration; incorporation of PEG to a culture medium did not affect medium water potential. The highest maturation results were achieved on a medium gelled with 10 g l−1 agar. Moreover, these somatic embryos had improved germination rates. These results corroborate the role of water restriction as a key factor controlling maturation of somatic embryos. 相似文献
996.
Hackl M Jakobi T Blom J Doppmeier D Brinkrolf K Szczepanowski R Bernhart SH Höner Zu Siederdissen C Bort JA Wieser M Kunert R Jeffs S Hofacker IL Goesmann A Pühler A Borth N Grillari J 《Journal of biotechnology》2011,153(1-2):62-75
Chinese hamster ovary (CHO) cells are the predominant cell factory for the production of recombinant therapeutic proteins. Nevertheless, the lack in publicly available sequence information is severely limiting advances in CHO cell biology, including the exploration of microRNAs (miRNA) as tools for CHO cell characterization and engineering. In an effort to identify and annotate both conserved and novel CHO miRNAs in the absence of a Chinese hamster genome, we deep-sequenced small RNA fractions of 6 biotechnologically relevant cell lines and mapped the resulting reads to an artificial reference sequence consisting of all known miRNA hairpins. Read alignment patterns and read count ratios of 5' and 3' mature miRNAs were obtained and used for an independent classification into miR/miR* and 5p/3p miRNA pairs and discrimination of miRNAs from other non-coding RNAs, resulting in the annotation of 387 mature CHO miRNAs. The quantitative content of next-generation sequencing data was analyzed and confirmed using qPCR, to find that miRNAs are markers of cell status. Finally, cDNA sequencing of 26 validated targets of miR-17-92 suggests conserved functions for miRNAs in CHO cells, which together with the now publicly available sequence information sets the stage for developing novel RNAi tools for CHO cell engineering. 相似文献
997.
Otto SP Pannell JR Peichel CL Ashman TL Charlesworth D Chippindale AK Delph LF Guerrero RF Scarpino SV McAllister BF 《Trends in genetics : TIG》2011,27(9):358-367
Sex chromosomes differ from other chromosomes in the striking divergence they often show in size, structure, and gene content. Not only do they possess genes controlling sex determination that are restricted to either the X or Y (or Z or W) chromosomes, but in many taxa they also include recombining regions. In these 'pseudoautosomal regions' (PARs), sequence homology is maintained by meiotic pairing and exchange in the heterogametic sex. PARs are unique genomic regions, exhibiting some features of autosomes, but they are also influenced by their partial sex linkage. Here we review the distribution and structure of PARs among animals and plants, the theoretical predictions concerning their evolutionary dynamics, the reasons for their persistence, and the diversity and content of genes that reside within them. It is now clear that the evolution of the PAR differs in important ways from that of genes in either the non-recombining regions of sex chromosomes or the autosomes. 相似文献
998.
Lertxundi U Peral J Hernández R 《Revista espa?ola de geriatría y gerontología》2011,46(3):170-1; author reply 170
999.
1000.
Luque-Almagro VM Blasco R Martínez-Luque M Moreno-Vivián C Castillo F Roldán MD 《Biochemical Society transactions》2011,39(1):269-274
There are thousands of areas in the U.S.A. and Europe contaminated with cyanide-containing wastes as a consequence of a large number of industrial activities such as gold mining, steel and aluminium manufacturing, electroplating and nitrile pesticides used in agriculture. Chemical treatments to remove cyanide are expensive and generate other toxic products. By contrast, cyanide biodegradation constitutes an appropriate alternative treatment. In the present review we provide an overview of how cells deal in the presence of the poison cyanide that irreversible binds to metals causing, among other things, iron-deprivation conditions outside the cell and metalloenzymes inhibition inside the cell. In this sense, several systems must be present in a cyanotrophic organism, including a siderophore-based acquisition mechanism, a cyanide-insensitive respiratory system and a cyanide degradation/assimilation pathway. The alkaliphilic autochthonous bacterium Pseudomonas pseudocaligenes CECT5344 presents all these requirements with the production of siderophores, a cyanide-insensitive bd-related cytochrome [Cio (cyanide-insensitive oxidase)] and a cyanide assimilation pathway that generates ammonium, which is further incorporated into organic nitrogen. 相似文献