365 research outputs found
Identification of ferredoxin II as a major calcium binding protein in the nitrogen-fixing symbiotic bacterium Mesorhizobium loti
BACKGROUND: Legumes establish with rhizobial bacteria a nitrogen-fixing symbiosis which is of the utmost importance for both plant nutrition and a sustainable agriculture. Calcium is known to act as a key intracellular messenger in the perception of symbiotic signals by both the host plant and the microbial partner. Regulation of intracellular free Ca(2+) concentration, which is a fundamental prerequisite for any Ca(2+)-based signalling system, is accomplished by complex mechanisms including Ca(2+) binding proteins acting as Ca(2+) buffers. In this work we investigated the occurrence of Ca(2+) binding proteins in Mesorhizobium loti, the specific symbiotic partner of the model legume Lotus japonicus. RESULTS: A soluble, low molecular weight protein was found to share several biochemical features with the eukaryotic Ca(2+)-binding proteins calsequestrin and calreticulin, such as Stains-all blue staining on SDS-PAGE, an acidic isoelectric point and a Ca(2+)-dependent shift of electrophoretic mobility. The protein was purified to homogeneity by an ammonium sulfate precipitation procedure followed by anion-exchange chromatography on DEAE-Cellulose and electroendosmotic preparative electrophoresis. The Ca(2+) binding ability of the M. loti protein was demonstrated by (45)Ca(2+)-overlay assays. ESI-Q-TOF MS/MS analyses of the peptides generated after digestion with either trypsin or endoproteinase AspN identified the rhizobial protein as ferredoxin II and confirmed the presence of Ca(2+) adducts. CONCLUSIONS: The present data indicate that ferredoxin II is a major Ca(2+) binding protein in M. loti that may participate in Ca(2+) homeostasis and suggest an evolutionarily ancient origin for protein-based Ca(2+) regulatory systems. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12866-015-0352-5) contains supplementary material, which is available to authorized users
Preoperative digital three-dimensional planning for rhinoplasty
BACKGROUND: This report describes preoperative digital planning for rhinoplasty using a new three-dimensional (3D) radiologic viewer that allows both patients and surgeons to visualize on a common monitor the 3D real aspect of the nose in its inner and outer sides.
METHODS: In the period 2002 to 2008, 210 patients underwent rhinoplasty procedures in the authors' clinic. The patients were randomly divided into three groups according to the type of preoperative planning used: photos only, a simulated result by Adobe Photoshop, or the 3D radiologic viewer. The parameters evaluated included the number of patients that underwent surgery after the first consultation, the number of patients who asked for a reintervention, patient satisfaction (according to a test given to the patients 12 months postoperatively), the surgical time required for a functional intervention, and the improvement in nasal function by postoperative rhinomanometry and subjective evaluation.
RESULTS: Computer-aided technologies led to a higher number of patients deciding to undergo a rhinoplasty. Simulation of the postoperative results was not as useful in the postoperative period due to the higher number of reintervention requests.
CONCLUSION: The patients undergoing rhinoplasties preferred new technologies in the preoperative period. The advantages of using the 3D radiologic viewer included improved preoperative planning, reduction in intraoperative stress, a higher number of patients undergoing surgery, reduction in postoperative surgical corrections, reduction in surgical time for the functional intervention, a higher rate of improvement in nasal function, a higher percentage of postoperative satisfaction, and reduced costs
Base sizes of primitive permutation groups
This work was supported by: EPSRC Grant Numbers EP/R014604/1 and EP/M022641/1.Let G be a permutation group, acting on a set Ω of size n. A subset B of Ω is a base for G if the pointwise stabilizer G(B) is trivial. Let b(G) be the minimal size of a base for G. A subgroup G of Sym(n) is large base if there exist integers m and r ≥ 1 such that Alt (m)r ... G ≤ Sym (m) \wr Sym (r), where the action of Sym (m) is on k-element subsets of {1,...,m} and the wreath product acts with product action. In this paper we prove that if G is primitive and not large base, then either G is the Mathieu group M24 in its natural action on 24 points, or b(G) ≤ ⌈log n⌉ + 1. Furthermore, we show that there are infinitely many primitive groups G that are not large base for which b(G) > log n + 1, so our bound is optimal.Publisher PDFPeer reviewe
Evidence for calcium-mediated perception of plant symbiotic signals in aequorin-expressing Mesorhizobium loti
<p>Abstract</p> <p>Background</p> <p>During the interaction between rhizobia and leguminous plants the two partners engage in a molecular conversation that leads to reciprocal recognition and ensures the beginning of a successful symbiotic integration. In host plants, intracellular Ca<sup>2+ </sup>changes are an integral part of the signalling mechanism. In rhizobia it is not yet known whether Ca<sup>2+ </sup>can act as a transducer of symbiotic signals.</p> <p>Results</p> <p>A plasmid encoding the bioluminescent Ca<sup>2+ </sup>probe aequorin was introduced into <it>Mesorhizobium loti </it>USDA 3147<sup>T </sup>strain to investigate whether a Ca<sup>2+ </sup>response is activated in rhizobia upon perception of plant root exudates. We find that <it>M. loti </it>cells respond to environmental and symbiotic cues through transient elevations in intracellular free Ca<sup>2+ </sup>concentration. Only root exudates from the homologous host <it>Lotus japonicus </it>induce Ca<sup>2+ </sup>signalling and downstream activation of nodulation genes. The extracellular Ca<sup>2+ </sup>chelator EGTA inhibits both transient intracellular Ca<sup>2+ </sup>increase and inducible <it>nod </it>gene expression, while not affecting the expression of other genes, either constitutively expressed or inducible.</p> <p>Conclusion</p> <p>These findings indicate a newly described early event in the molecular dialogue between plants and rhizobia and highlight the use of aequorin-expressing bacterial strains as a promising novel approach for research in legume symbiosis.</p
Transcriptional analysis of calcium-dependent and calcium-independent signalling pathways induced by oligogalacturonides
alpha-1,4-linked oligogalacturonides (OGs) are pectic fragments of plant cell walls that are able to induce defence and developmental responses. To understand plant responses to OGs at the transcriptional level, changes in gene expression were examined using oligonucleotide-based microarrays that cover almost the entire Arabidopsis transcriptome. In suspension-cultured Arabidopsis thaliana (L.) Columbia hypocotyl cells, approximately 4% of the total transcriptome exhibited significant change in abundance in response to treatment with OGs for 2 h. Steady-state changes in the abundance of transcripts encoding stress- and disease-related proteins, signalling components, and transcription factors were particularly noteworthy. As in other plant cell types, OGs elicit a rapid, but transient, elevation in cytosolic free Ca(2+). The Ca(2+) transient can be abolished by the protein kinase inhibitor 4,5,6,7-tetrabromobenzotriazole (TBB) and by the Ca(2+) channel inhibitor La(3+), thereby facilitating a distinction between Ca(2+)-dependent and -independent transcriptional responses. Among the 244 transcripts that were up-regulated by OGs, the response of 93 (38%) was selectively sensitive to abolition of the Ca(2+) transient. These OG-up-regulated, Ca(2+)-dependent transcripts included two noteworthy classes, the first comprising genes involved in cell wall modification following pathogen attack, and the second consisting of genes involved in the biosynthesis of jasmonate and C6 volatile compounds. These results support the notion of an important role for cytosolic Ca(2+) signalling in jasmonate biosynthesis following OG perception. Promoter analysis of OG-induced, inhibitor-sensitive and -insensitive genes identified several putative cis-elements that might be involved specifically in Ca(2+)-dependent transcriptional regulation
Psychological Profile and Quality of Life of Morbid Obese Patients Attending a Cognitive Behavioural Program
The results show that 27% of cases had a BES score ≥ 17, indicative of possible binge eating, and 13% had a BES ≥ 27, largely indicative of binge eating, with a higher prevalence in females. The BDI score was above normal in 30% of males and 45% of females, and 13% of females were in the range of moderate-severe depression. BES and BDI were significantly correlated with each other. Orwell-97 was much higher in females, and similarly the generic PGWB was indicative of a poorer HRQL in females. PGWB was positively associated with age, without any effect of BMI. The association with age was maintained in female, not in males. Both the Orwell-97 and the PGWB were associated with both BES and BDI in both genders. Psychological distress is common and largely variable in patients attending CBT for morbid obesity. This data should be considered for individual treatment protocols, and should be compared with similar series of patients enrolled for bariatric surger
Groups satisfying a strong complement property
Let G = NH be a finite group where N is normal in G and H is a complement of N in G. For a given generating sequence (h(1),.., h(d)) of H we say that (N, (h(1),..., h(d))) satisfies the strong complement property, if is a complement of N in G for all x(1),..., x(d) is an element of N. When d is the minimal number of elements needed to generate H, and (N, (h(1),..., h(d)>)) satisfies the strong complement property for every generating sequence (h(1),..., h(d)) with length d, then we say that (N, H) satisfies the strong complement property. In the case when vertical bar N vertical bar and vertical bar H vertical bar are coprime, we show that (N, H) can only satisfy the strong complement property if H is cyclic or if H acts trivially on N. We give on the other hand a number of examples that show this does not need to be the case when considering the strong complement property of (N, (h(1),..., h(d))) for a given fixed generating sequence. In the case when N and H are not of coprime order, we give examples where (N, H) satisfies the strong complement property and where H is not cyclic and does not act trivially on N
Physical activity for the prevention and treatment of metabolic disorders
Metabolic syndrome and its various features 10 (obesity, hypertension, dyslipidemia, diabetes, and nonal- 11 coholic fatty liver disease) are increasing worldwide and 12 constitute a severe risk for the sustainability of the present 13 universal Italian health care system. Lifestyle interventions 14 should be the first therapeutic strategy to prevent/treat 15 metabolic diseases, far before pharmacologic treatment. 16 The role of diet and weight loss has been fully ascertained, 17 whereas the role of physical activity is frequently over- 18 looked both by physicians and by patients. Physical activity 19 has favorable effects on all components of the metabolic 20 syndrome and on the resulting cardiovascular risk, the 21 cornerstone in the development of cardiometabolic dis- 22 eases. The quantity and the frequency of physical activity 23 necessary to produce beneficial effects has not been defined 24 as yet, but brisk walking is considered particularly appro- 25 priate, as it can be practiced by a large number of indi- 26 viduals, without any additional cost, and has a low rate of 27 injury. The effects of exercise and leisure time physical 28 activity extend from prevention to treatment of the various 29 components of the metabolic syndrome, as well as to mood 30 and quality of life. Any effort should be done to favor adherence to protocols of physical activity in the 31 community
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