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51.
Identification of a protein coded by pR plasmid and involved in SOS repair in E. coli. 总被引:2,自引:1,他引:1
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The TP120 plasmid is known to determine enhanced UV survival in E. coli wild type an uvrB and PolA mutants but not in RecA mutant. In order to analyze the function involved in the SOS repair, we have constructed a new plasmid named pR derived by cleavage of TP120 with Hind III endonuclease. This new plasmid maintains the Ap and UV resistance. The insertion of Tn5 transposon in the plasmid allows to select several pR::Tn5 plasmids whose UV resistance was inactivated by the transposition. The comparison of the protein synthesis in the minicells of the pR and pR::Tn5 shows that the pR codes for a 22.000 M.W. dalton protein which is absent in protein pattern of pR::Tn5. 相似文献
52.
Radaelli A Paganini M Basavecchia V Elli V Neri M Zanotto C Pontieri E De Giuli Morghen C 《Letters in applied microbiology》2004,38(6):447-453
AIM: To investigate the composition of the microbial community in biodeterioration of two frescoes in St Damian's Monastery in Assisi. METHODS AND RESULTS: A total of 1292 colonies were isolated from the most deteriorated parts, analysed by microbiological, biomolecular and ultrastructural techniques, and taxonomically classified. Molecular biotyping of Staphylococcus cohnii colonies, one of the most prevalent bacterial species, showed a very restricted genome diversity while Bacillus licheniformis were very homogeneous by RFLP, tDNA-PCR and random-amplified polymorphic DNA. Electron microscopy confirmed heterogeneity of the bacterial population in the different sampling areas. CONCLUSIONS: Several of the identified species are widespread in the soil or saprophytes of human skin. Although unable to demonstrate that they are involved in biodeterioration, they may represent trophic elements contributing to fungi-related chromatic alterations when adequate environmental conditions occur. Deterioration may in part be prevented or controlled by adequate air filtering or conditioning of the room. 相似文献
53.
Summary The kinetics of the nuclear and cytoplasmic fluorescence response to glycolytic substrate were studied in ascites cells in culture (EL2 cells) and radiation giants (EL2G) maintained under a variety of conditions, using a beam-splitter supplemented microfluorimeter which allows fluorescence recording simultaneously with microelectrophoretic addition of substrate. A sequence of fluorescence pulses which resemble closely the curve of formation and disappearance of the enzyme-substrate complex were obtained upon repetitive additions of substrate. The pulses were analyzed in terms of peak fluorescence response (PFR), duration of steady state, halftime of fluorescence rise and decay (tin1/2off), number of consecutive cycles elicited, etc. There is a considerable parallelism in the kinetics of the nuclear and cytoplasmic fluorescence after addition of glycolytic substrate, over the whole time course of consecutive pulses. However in untreated, Amytal- or Rotenone-perfused cells the peak magnitudes of the cytoplasmic fluorescence are significantly lower and the cytoplasmic pulses are damped earlier than the nuclear upon repeated additions of substrate. In Amytal-grown EL2 cells there is a drop of PFR and a prolongation of t
1/2off in the nucleus and cytoplasm, which persists when the cells are transferred to an Amytal-free medium. However, if the cells are maintained for longer periods in Amytal, the nuclear fluorescence tends to return to control level, while the cytoplasmic pulses remain small and are easily damped. In T3- or Amytal + T3 -grown EL2 cells the cytoplasmic fluorescence instead of dropping like in the controls, follows the nuclear level over the whole time course of repeated pulses, and can even exceed the nuclear. Comparable phenomena are observed in T3 -and Insulin-grown radiation giants When the amount of substrate is varied, starting from levels which can barely elicit a response the magnitude of the fluorescence response (integrated fluorescence pulse) in the cytoplasm and nucleus follows a sigmoid curve which can be interpreted as a function of allosteric enzymes.List of Abbreviations EL2
mouse Ehrlich ascites cells in tissue culture
- EL2G
giant tissue culture mouse Ehrlich ascites cells obtained by X-irradiation
- EL2T
giant tissue culture EL2 cells obtained by treatment with Trenimon (2.3.5-Tris aethyleniminobenzochinon-1.4)
- G6P
glucose-6-phosphate
- FDP
fructose-1.6-diphosphate
- 6 PG
6-phospho-gluconate
- UDPG
uridine-5-diphosphoglucose
- AMP
adenosine-5-monophosphate
- ADP
adenosine-5-diphosphate
- G1P
D-glucose-1-phosphate
- PFR
peak fluorescence response
-
t
1/2off
halftime of fluorescence rise and decay
- T3
triidothyronine 相似文献
54.
Panagiotis Beretsos George A Partsinevelos Eleni Arabatzi Peter Drakakis Depy Mavrogianni Elli Anagnostou Kostas Stefanidis Aris Antsaklis Dimitris Loutradis 《Reproductive biology and endocrinology : RB&E》2009,7(1):91
Background
Recently, it has been demonstrated that, in patients down-regulated by GnRH analogues (GnRHa), a short-term pre-treatment with recombinant LH (rLH), prior to recombinant FSH (rFSH) administration, increases the number of small antral follicle prior to FSH stimulation and the yield of normally fertilized embryos. However, no data exist in the literature regarding the potential beneficial effect of "hCG priming" in controlled ovarian hyperstimulation (COH) through a long GnRH-a protocol, which binds the same receptor (LH/hCGR), though it is a much more potent compared to LH. The primary aims of this study were to assess the effect of short-term pre-rFSH administration of hCG in women entering an ICSI treatment cycle on follicular development, quality of oocytes and early embryo development. The secondary endpoints were to record the effects on endometrial quality and pregnancy rate. 相似文献55.
Bouakaz L Bouakaz E Murgola EJ Ehrenberg M Sanyal S 《The Journal of biological chemistry》2006,281(7):4548-4556
It has been suggested from in vivo and cryoelectron micrographic studies that the large ribosomal subunit protein L11 and its N-terminal domain play an important role in peptide release by, in particular, the class I release factor RF1. In this work, we have studied in vitro the role of L11 in translation termination with ribosomes from a wild type strain (WT-L11), an L11 knocked-out strain (DeltaL11), and an L11 N terminus truncated strain (Cter-L11). Our data show 4-6-fold reductions in termination efficiency (k(cat)/K(m)) of RF1, but not of RF2, on DeltaL11 and Cter-L11 ribosomes compared with wild type. There is, at the same time, no effect of these L11 alterations on the maximal rate of ester bond cleavage by either RF1 or RF2. The rates of dissociation of RF2 but not of RF1 from the ribosome after peptide release are somewhat reduced by the L11 changes irrespective of the presence of RF3, and they cause a 2-fold decrease in the missense error. Our results suggest that the L11 modifications increase nonsense suppression at UAG codons because of the reduced termination efficiency of RF1 and that they decrease nonsense suppression at UGA codons because of a decreased missense error level. 相似文献
56.
Ciceri P Volpi E Brenna I Elli F Borghi E Brancaccio D Cozzolino M 《Biochemical and biophysical research communications》2012,418(4):770-773
Phosphate (Pi)-binders are commonly used in dialysis patients to control high Pi levels, that associated with vascular calcification (VC). The aim of this study was to investigate the effects of lanthanum chloride (LaCl(3)) on the progression of high Pi-induced VC, in rat vascular smooth muscle cells (VSMCs). Pi-induced Ca deposition was inhibited by LaCl(3), with a maximal effect at 100μM (59.0±2.5% inhibition). Furthermore, we studied the effects on VC of calcium sensing receptor (CaSR) agonists. Gadolinium chloride, neomycin, spermine, and the calcimimetic calindol significantly inhibited Pi-induced VC (55.9±2.2%, 37.3±4.7%, 30.2±5.7%, and 63.8±5.7%, respectively). To investigate the hypothesis that LaCl(3) reduces the progression of VC by interacting with the CaSR, we performed a concentration-response curve of LaCl(3) in presence of a sub-effective concentration of calindol (10nM). Interestingly, this curve was shifted to the left (IC(50) 9.6±2.6μM), compared to the curve in the presence of LaCl(3) alone (IC(50) 19.0±4.8μM). In conclusion, we demonstrated that lanthanum chloride effectively reduces the progression of high phosphate-induced vascular calcification. In addition, LaCl(3) cooperates with the calcimimetic calindol in decreasing Ca deposition in this in vitro model. These results suggest the potential role of lanthanum in the treatment of VC induced by high Pi. 相似文献
57.
Pseudohypoparathyroidism-Ia and -Ib (PHP-Ia and -Ib) are caused by mutations in GNAS exons 1-13 and methylation defects in the imprinted GNAS cluster, respectively. PHP-Ia patients show Albright hereditary osteodystrophy (AHO), together with resistance to the action of different hormones that activate the Gs-coupled pathway. In PHP-Ib patients AHO is classically absent and hormone resistance is limited to PTH and TSH. This disorder is caused by GNAS methylation alterations with loss of imprinting at the exon A/B differentially methylated region (DMR) being the most consistent and recurrent defect. The familial form of the disease (AD-PHP-Ib) is typically associated with an isolated loss of imprinting at the exon A/B DMR due to microdeletions disrupting the upstream STX16 gene. In addition, deletions removing the entire NESP55 DMR, located within GNAS, associated with loss of all the maternal GNAS imprints have been identified in some AD-PHP-Ib kindreds. Conversely, most sporadic PHP-Ib cases have GNAS imprinting abnormalities that involve multiple DMRs, but the genetic lesion underlying these defects is unknown. Recently, methylation defects have been detected in a subset of patients with PHP-Ia and variable degrees of AHO, indicating a molecular overlap between the 2 forms. Imprinting defects do not seem to be associated with the severity of AHO neither with specific AHO signs. In conclusion, the latest findings on the molecular basis underlying these defects suggest the existence of a clinical and genetic/epigenetic overlap between PHP-Ia and PHP-Ib, and highlight the necessity of a new clinical classification of these disorders based on molecular findings. 相似文献
58.
59.
60.
Dimitrios Daoussis Athanassios C Tsamandas Stamatis-Nick C Liossis Ioannis Antonopoulos Elli Karatza Georgios Yiannopoulos Andrew P Andonopoulos 《Arthritis research & therapy》2012,14(3):R145