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671.
Martinelli T Whittaker A Masclaux-Daubresse C Farrant JM Brilli F Loreto F Vazzana C 《Journal of experimental botany》2007,58(14):3929-3939
The possible role of photorespiration as a general stress protectionmechanism, and in C4 plant metabolism, is controversial. Inparticular, the potential involvement of photorespiration inthe acquisition of desiccation tolerance in resurrectionplants is unknown. An investigation was carried out into whetherphotorespiration is present in leaves of the C4 resurrectionplant Sporobolus stapfianus Gandoger (Poaceae) and whether itfunctions as a mechanism of stress resistance in the desiccation-tolerantyounger leaves (YL) of this plant. It is shown that the enzymesinvolved in the photorespiratory pathway maintain their activityuntil 88% relative water content (RWC) in both YL and desiccation-sensitiveolder leaves (OL). In subsequent stages of dehydration stress,the enzymatic activity declined similarly in both YL and OL.The content of the phorespiratory metabolite, serine, and ethanolamine,a direct product of serine decarboxylation, is higher in theearly stages of dehydration (88% RWC) in OL, suggesting a transientlyenhanced photorespiratory activity in these leaves. This wasconfirmed by simultaneous gas exchange and fluorescence measurements,showing suppression of the electron transport rate in OL exposedto non-photorespiratory conditions (2% O2) at 85% RWC. It isconcluded that a higher photorespiratory electron transportoccurs in desiccation-sensitive OL, and it is therefore proposedthat the capacity to scavenge excess electrons through photorespirationdoes not contribute to protect leaves of the desiccation-tolerantYL of S. stapfianus during the stress. Key words: Ethanolamine, glycine, photorespiratory enzymes, photosynthesis, poikilohydric plant, serine
Received 5 June 2007; Revised 3 September 2007 Accepted 17 September 2007 相似文献
672.
Parind Mahendrakumar Desai Patrick Xuan Hua Er Celine Valeria Liew Paul Wan Sia Heng 《AAPS PharmSciTech》2014,15(5):1093-1104
Investigation of the effect of disintegrants on the disintegration time and hardness of rapidly disintegrating tablets (RDTs) was carried out using a quality by design (QbD) paradigm. Ascorbic acid, aspirin, and ibuprofen, which have different water solubilities, were chosen as the drug models. Disintegration time and hardness of RDTs were determined and modeled by executing combined optimal design. The generated models were validated and used for further analysis. Sodium starch glycolate, croscarmellose sodium, and crospovidone were found to lengthen disintegration time when utilized at high concentrations. Sodium starch glycolate and crospovidone worked synergistically in aspirin RDTs to decrease disintegration time. Sodium starch glycolate-crospovidone mixtures, as well as croscarmellose sodium-crospovidone mixtures, also decreased disintegration time in ibuprofen RDTs at high compression pressures as compared to the disintegrants used alone. The use of sodium starch glycolate in RDTs with highly water soluble active ingredients like ascorbic acid slowed disintegration, while microcrystalline cellulose and crospovidone drew water into the tablet rapidly and quickened disintegration. Graphical optimization analysis demonstrated that the RDTs with desired disintegration times and hardness can be formulated with a larger area of design space by combining disintegrants at difference compression pressures. QbD was an efficient and effective paradigm in understanding formulation and process parameters and building quality in to RDT formulated systems.KEY WORDS: disintegrants, quality by design, rapidly disintegrating tablets 相似文献
673.
Background
Self-harm entails high costs to individuals and society in terms of suicide risk, morbidity and healthcare expenditure. Repetition of self-harm confers yet higher risk of suicide and risk assessment of self-harm patients forms a key component of the health care management of self-harm patients. To date, there has been no systematic review published which synthesises the extensive evidence on risk factors for repetition.Objective
This review is intended to identify risk factors for prospective repetition of self-harm after an index self-harm presentation, irrespective of suicidal intent.Data sources
PubMed, PsychInfo and Scirus were used to search for relevant publications. We included cohort studies which examining factors associated with prospective repetition among those presenting with self-harm to emergency departments. Journal articles, abstracts, letters and theses in any language published up to June 2012 were considered. Studies were quality-assessed and synthesised in narrative form.Results
A total of 129 studies, including 329,001 participants, met our inclusion criteria. Some factors were studied extensively and were found to have a consistent association with repetition. These included previous self-harm, personality disorder, hopelessness, history of psychiatric treatment, schizophrenia, alcohol abuse/dependence, drug abuse/dependence, and living alone. However, the sensitivity values of these measures varied greatly across studies. Psychological risk factors and protective factors have been relatively under-researched but show emerging associations with repetition. Composite risk scales tended to have high sensitivity but poor specificity.Conclusions
Many risk factors for repetition of self-harm match risk factors for initiation of self-harm, but the most consistent evidence for increased risk of repetition comes from long-standing psychosocial vulnerabilities, rather than characteristics of an index episode. The current review will enhance prediction of self-harm and assist in the efficient allocation of intervention resources. 相似文献674.
675.
Alexander M. Brown Anna M. Kopps Simon J. Allen Lars Bejder Bethan Littleford-Colquhoun Guido J. Parra Daniele Cagnazzi Deborah Thiele Carol Palmer Celine H. Frère 《PloS one》2014,9(7)
Little is known about the Australian snubfin (Orcaella heinsohni) and Indo-Pacific humpback (Sousa chinensis) dolphins (‘snubfin’ and ‘humpback dolphins’, hereafter) of north-western Australia. While both species are listed as ‘near threatened’ by the IUCN, data deficiencies are impeding rigorous assessment of their conservation status across Australia. Understanding the genetic structure of populations, including levels of gene flow among populations, is important for the assessment of conservation status and the effective management of a species. Using nuclear and mitochondrial DNA markers, we assessed population genetic diversity and differentiation between snubfin dolphins from Cygnet (n = 32) and Roebuck Bays (n = 25), and humpback dolphins from the Dampier Archipelago (n = 19) and the North West Cape (n = 18). All sampling locations were separated by geographic distances >200 km. For each species, we found significant genetic differentiation between sampling locations based on 12 (for snubfin dolphins) and 13 (for humpback dolphins) microsatellite loci (F
ST = 0.05–0.09; P<0.001) and a 422 bp sequence of the mitochondrial control region (F
ST = 0.50–0.70; P<0.001). The estimated proportion of migrants in a population ranged from 0.01 (95% CI 0.00–0.06) to 0.13 (0.03–0.24). These are the first estimates of genetic diversity and differentiation for snubfin and humpback dolphins in Western Australia, providing valuable information towards the assessment of their conservation status in this rapidly developing region. Our results suggest that north-western Australian snubfin and humpback dolphins may exist as metapopulations of small, largely isolated population fragments, and should be managed accordingly. Management plans should seek to maintain effective population size and gene flow. Additionally, while interactions of a socio-sexual nature between these two species have been observed previously, here we provide strong evidence for the first documented case of hybridisation between a female snubfin dolphin and a male humpback dolphin. 相似文献
676.
Gabriela Petrof Arti Nanda Jake Howden Takuya Takeichi James?R. McMillan Sophia Aristodemou Linda Ozoemena Lu Liu Andrew?P. South Celine Pourreyron Dimitra Dafou Laura?E. Proudfoot Hejab Al-Ajmi Masashi Akiyama W.H.?Irwin McLean Michael?A. Simpson Maddy Parsons John?A. McGrath 《American journal of human genetics》2014,95(3):308-314
677.
Jae Eun Kim Qun He Yaqing Chen Celine Shi Ker Yu 《Biochemical and biophysical research communications》2014
While cancer cell mitochondria mediate actions of many successful chemotherapeutics, little is known about mitochondrial response in mTOR-targeted anticancer therapy. We have studied mitochondrial dynamics in relation to growth suppression employing an allosteric inhibitor rapalog, a highly selective mTOR kinase inhibitor (mTOR-KI) and mTOR-ShRNA. Global targeting of mTOR increased mitochondrial membrane potential (mΔψ) and inhibited mitochondrial permeability transition pore (mPTP). Importantly, these mTOR-KI-provoked anti-survival and pro-survival effects were differentially manifested in diverse cancer cells according to intrinsic susceptibility to mTOR-targeting. The most-sensitive cells including those possessing hyperactive PI3K/AKT/mTOR and/or growth factor-dependence (LNCap, MDA361 and MG63) all displayed a dramatic increase in mΔψ, whereas the mΔψ increase was not evident in majority of resistant cancer cells. Upon mTOR-KI treatment, the resistant cells including those harboring K-Ras- or B-Raf mutation (MDA231, HT29 and HCT116) all displayed a markedly reduced mPTP opening, which paralleled a sustained AKT-hexokinase 2 (HK2) survival signaling and persistent phosphorylation (inactivation) of GSK3β. Further studies demonstrated that the mTOR-KI-provoked mPTP closure in resistant cells was mediated through an enhanced binding of HK2 to the mitochondrial voltage-dependent anion channel (VDAC), a molecular mechanism known to promote mPTP closure and cell survival. Detaching HK2 from VDAC by an HK2-displacing peptide or methyl jasmonate specifically blocked the mTOR-KI-provoked mPTP closure and potentiated growth suppression in resistant cells. Thus, mTOR-inhibition can exert complex and differential perturbation to mitochondrial dynamics in cancer cells, which likely influence therapeutic outcome of mTOR-targeted therapy. 相似文献
678.
Maraike Willsch Victor Dacosta Marie‐Lilith Patou Adrian Seymour Celine Bonillo Arnaud Couloux Siew Te Wong Andrew P. Jennings Jörns Fickel Andreas Wilting 《Zoological Journal of the Linnean Society》2014,170(4):917-932
The Malay civet Viverra tangalunga Gray, 1832 is a fairly large viverrid that has a wide distribution in both the Sundaic and Wallacea regions of Southeast Asia. We investigated the genetic diversity of V. tangalunga by analysing the mitochondrial DNA of 81 individuals throughout its range in order to elucidate the evolutionary history of this species and to test the hypotheses of natural dispersal and/or potential human introductions to some islands and regions. Our phylogenetic analyses revealed that V. tangalunga has a low matrilinear genetic diversity and is poorly structured geographically. Borneo is likely to have served as the ancestral population source from which animals dispersed during the Pleistocene. Viverra tangalunga could have naturally dispersed to Peninsular Malaysia, Sumatra, and Belitung, and also to several other Sunda Islands (Bangka, Lingga, and Bintang in the Rhio Archipelago), and to Palawan, although there is possible evidence that humans introduced V. tangalunga to the latter islands. Our results strongly suggested that V. tangalunga was transported by humans across Wallace's Line to Sulawesi and the Moluccas, but also to the Philippines and the Natuna Islands. Our study has shown that human‐mediated dispersal can be an important factor in understanding the distribution of some species in this region. © 2014 The Linnean Society of London 相似文献
679.
Bioinformatic analysis of ESTs collected by Sanger and pyrosequencing methods for a keystone forest tree species: oak 总被引:1,自引:0,他引:1
Saneyoshi Ueno Grégoire Le Provost Valérie Léger Christophe Klopp Céline Noirot Jean-Marc Frigerio Franck Salin Jérôme Salse Michael Abrouk Florent Murat Oliver Brendel Jérémy Derory Pierre Abadie Patrick Léger Cyril Cabane Aurélien Barré Antoine de Daruvar Arnaud Couloux Patrick Wincker Marie-Pierre Reviron Antoine Kremer Christophe Plomion 《BMC genomics》2010,11(1):1-24
Background
Helicobacter mustelae causes gastritis, ulcers and gastric cancer in ferrets and other mustelids. H. mustelae remains the only helicobacter other than H. pylori that causes gastric ulceration and cancer in its natural host. To improve understanding of H. mustelae pathogenesis, and the ulcerogenic and carcinogenic potential of helicobacters in general, we sequenced the H. mustelae genome, and identified 425 expressed proteins in the envelope and cytosolic proteome.Results
The H. mustelae genome lacks orthologs of major H. pylori virulence factors including CagA, VacA, BabA, SabA and OipA. However, it encodes ten autotransporter surface proteins, seven of which were detected in the expressed proteome, and which, except for the Hsr protein, are of unknown function. There are 26 putative outer membrane proteins in H. mustelae, some of which are most similar to the Hof proteins of H. pylori. Although homologs of putative virulence determinants of H. pylori (NapA, plasminogen adhesin, collagenase) and Campylobacter jejuni (CiaB, Peb4a) are present in the H. mustelae genome, it also includes a distinct complement of virulence-related genes including a haemagglutinin/haemolysin protein, and a glycosyl transferase for producing blood group A/B on its lipopolysaccharide. The most highly expressed 264 proteins in the cytosolic proteome included many corresponding proteins from H. pylori, but the rank profile in H. mustelae was distinctive. Of 27 genes shown to be essential for H. pylori colonization of the gerbil, all but three had orthologs in H. mustelae, identifying a shared set of core proteins for gastric persistence.Conclusions
The determination of the genome sequence and expressed proteome of the ulcerogenic species H mustelae provides a comparative model for H. pylori to investigate bacterial gastric carcinogenesis in mammals, and to suggest ways whereby cag minus H. pylori strains might cause ulceration and cancer. The genome sequence was deposited in EMBL/GenBank/DDBJ under accession number FN555004. 相似文献680.
We have compared the use of a low resolution MALDI-Ion Trap MS/MS and a high-resolution ESI-TOF-MS/MS for the analysis of spots from 2D gels. The main criteria were speed and accuracy of protein identification. The results obtained using the MALDI-MS/MS system are comparable to those from the LC-MS/MS system in terms of accuracy, but less low-level proteins are identified while the time required for the analysis is dramatically reduced. 相似文献