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431.
Martin Enders Frank Havemann Florian Ruland Maud Bernard‐Verdier Jane A. Catford Lorena Gmez‐Aparicio Sylvia Haider Tina Heger Christoph Kueffer Ingolf Kühn Laura A. Meyerson Camille Musseau Ana Novoa Anthony Ricciardi Alban Sagouis Conrad Schittko David L. Strayer Montserrat Vil Franz Essl Philip E. Hulme Mark van Kleunen Sabrina Kumschick Julie L. Lockwood Abigail L. Mabey Melodie A. McGeoch Estíbaliz Palma Petr Pyek Wolf‐Christian Saul Florencia A. Yannelli Jonathan M. Jeschke 《Global Ecology and Biogeography》2020,29(6):978-991
432.
Beatrice Aramini Valentina Masciale Khawaja Husnain Haider 《World journal of stem cells》2020,12(6):406-421
Since the first publication regarding the existence of stem cells in cancer [cancer stem cells(CSCs)] in 1994, many studies have been published providing in-depth information about their biology and function. This research has paved the way in terms of appreciating the role of CSCs in tumour aggressiveness, progression,recurrence and resistance to cancer therapy. Targeting CSCs for cancer therapy has still not progressed to a sufficient degree, particularly in terms of exploring the mechanism of dynamic interconversion between CSCs and non-CSCs. Besides the CSC scenario, the problem of cancer dissemination has been analyzed indepth with the identification and isolation of microRNAs(miRs), which are now considered to be compelling molecular markers in the diagnosis and prognosis of tumours in general and specifically in patients with non-small cell lung cancer.Paracrine release of miRs via "exosomes"(small membrane vesicles(30-100 nm),the derivation of which lies in the luminal membranes of multi-vesicular bodies)released by fusion with the cell membrane is gaining popularity. Whether exosomes play a significant role in maintaining a dynamic equilibrium state between CSCs and non-CSCs and their mechanism of activity is as yet unknown.Future studies on CSC-related exosomes will provide new perspectives for precision-targeted treatment strategies. 相似文献
433.
Tapani Hovi Carita Savolainen-Kopra Teemu Smura Soile Blomqvist Haider Al-Hello Merja Roivainen 《PloS one》2013,8(6)
Partial sequences of 110 type 2 poliovirus strains isolated from sewage in Slovakia in 2003–2005, and most probably originating from a single dose of oral poliovirus vaccine, were subjected to a detailed genetic analysis. Evolutionary patterns of these vaccine derived poliovirus strains (SVK-aVDPV2) were compared to those of type 1 and type 3 wild poliovirus (WPV) lineages considered to have a single seed strain origin, respectively. The 102 unique SVK-aVDPV VP1 sequences were monophyletic differing from that of the most likely parental poliovirus type 2/Sabin (PV2 Sabin) by 12.5–15.6%. Judging from this difference and from the rate of accumulation of synonymous transversions during the 22 month observation period, the relevant oral poliovirus vaccine dose had been administered to an unknown recipient more than 12 years earlier. The patterns of nucleotide substitution during the observation period differed from those found in the studied lineages of WPV1 or 3, including a lower transition/transversion (Ts/Tv) bias and strikingly lower Ts/Tv rate ratios at the 2nd codon position for both purines and pyrimidines. A relatively low preference of transitions at the 2nd codon position was also found in the large set of VP1 sequences of Nigerian circulating (c)VDPV2, as well as in the smaller sets from the Hispaniola cVDPV1 and Egypt cVDPV2 outbreaks, and among aVDPV1and aVDPV2 strains recently isolated from sewage in Finland. Codon-wise analysis of synonymous versus non-synonymous substitution rates in the VP1 sequences suggested that in five codons, those coding for amino acids at sites 24, 144, 147, 221 and 222, there may have been positive selection during the observation period. We conclude that pattern of poliovirus VP1 evolution in prolonged infection may differ from that found in WPV epidemics. Further studies on sufficiently large independent datasets are needed to confirm this suggestion and to reveal its potential significance. 相似文献
434.
A simple, rapid and sensitive chemiluminescent (CL) method for the assay of venlafaxine (VEN) in pharmaceutical formulations and serum samples by a two‐chip device is proposed. The method is based on the reaction of this drug with a tris(2,2′‐bipyridyl) ruthenium(II)–peroxydisulphate CL system. The optimum chemical conditions for CL emission were investigated. The calibration graph was linear for the concentration range 0.02–8.0 µg/mL. The detection and quantification limits were found to be 0.006 and 0.018 µg/mL, respectively, while the relative standard deviation (RSD) was <2.0%. The present CL procedure was applied to the determination of VEN in pharmaceutical formulations and serum samples; the recovery levels were in the range 96.5–101.2%. The results suggest that the method is unaffected by the presence of common formulation excipients found in these samples. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
435.
Challa BR Awen BZ Chandu BR Rihanaparveen S 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2011,879(11-12):769-776
Liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was used for a quantitative estimation of entecavir (EV) in human plasma using lamivudine (LM) as internal standard (IS). The method herein described is simple, sensitive, and specific. Chromatographic separation was performed on XBridge-C18, 4.6 mm × 50 mm, 5-μm column with an isocratic mobile phase composed of 10 mM ammonium hydrogen carbonate (pH 10.5):methanol (85:15 v/v), pumped at 0.3 ml/min. EV and LM were detected using proton adducts at m/z 278.1→152.1 and 230.2→112.0 in multiple reaction monitoring (MRM) positive mode. Solid phase extraction method was employed in the extraction of EV and LM from the biological matrix. This method was validated over a linear concentration range of 50.0-20000.0 pg/ml with a correlation coefficient (r) ≥0.9983. Intra and inter-day precision of EV was found within the range of 1.2-4.2 for EV and 4.4-4.5 for LM. EV was stable throughout three freeze/thaw cycles, bench top and postoperative studies. This method was successfully used in the analysis of plasma samples following oral administration of EV (0.5 mg) in 26 healthy human volunteers. 相似文献
436.
N. Haider 《Russian Journal of Genetics》2013,49(3):263-274
Understanding the origin of cultivated wheats would further their genetic improvement. The hexaploid bread wheat (Triticum aestivum L., AABBDD) is believed to have originated through one or more rare hybridization events between Aegilops tauschii (DD) and the tetraploid T. turgidum (AABB). Progenitor, of the A-genome of the tetraploid and hexaploid wheats has generally been accepted to be T. urartu. In spite of the large number of attempts and published reports about the origin of the B-genome in cultivated wheats, the donor of the B-genome is still relatively unknown and controversial and, hence, remains open. This genome has been found to be closely related to the S-genome of the Sitopsis section (Ae. speltoides, Ae. longissima, Ae. sharonensis, Ae. searsii, and Ae. bicornis) of the genus Aegilops L. Among Sitopsis species, the most positive evidence has been accumulated for Ae. speltoides as the progenitor of the B-genome. Therefore, one or more of the Sitopsis species were proposed frequently as the B-genome donor. Although several reviews have been written on the origin of the genomes of wheat over the years, this paper will attempt for the first time to review the immense literature on the subject, with a particular emphasis on the B-genome which has attracted a huge attention over some 100 years. The ambiguity and conflicting results in most of the methods employed in deducing the precise B-genome donor/s to bread wheat are also discussed. 相似文献
437.
Nikhil Kothari Jaishri Bogra Haider Abbas Monica Kohli Anita Malik Divya Kothari Shivani Srivastava Prithvi K. Singh 《Cytokine》2013,61(2):676-681
IntroductionSystemic sepsis releases several cytokines among which tumor necrosis factor alfa (TNFα) has emerged as key cytokine causing septic shock. Single Nucleotide Polymorphisms (SNPs) at positions ?238, ?308, ?376 and +489 in the promoter region of TNF gene exhibit differential association to inflammation and increased TNF production in sepsis.Materials and MethodsThis research work was carried out in 278 critically ill patients and 115 controls. The patients were divided into four groups: Healthy controls, SIRS, Sepsis and Septic shock. Plasma cytokine level was evaluated by ELISA. Specific sequences of TNF gene (?238, ?308, ?376, +489) were amplified using polychromase chain reaction (PCR). SNP detected by BamHiI, NcoI, FokI, TaiI restriction enzymes.ResultsMean plasma TNFα level in healthy Control group was 8.37 ± 2.23 pg/ml, in SIRS group, the mean plasma TNFα level was 77.99 ± 5.51 pg/ml, in Sepsis patients 187.1 ± 14.33 pg/ml and in septic shock 202.2 ± 14.85 pg/ml; range 56.17–417.1 pg/ml. SNP was studied among different patient groups, which showed a higher frequency of mutants among sepsis and shock patients as compared to control.ConclusionPlasma TNF alpha level was significantly high in patients with sepsis and septic shock. SNP of TNF gene showed significant association between polymorphism and development of severe sepsis and septic shock, this would help us in evaluating patients at high risk for septic shock and such patients needed to obtain a rational basis for therapy. 相似文献
438.
Razia Khurshid Taimoor Khan Afifa Zaeem Laurine Garros Christophe Hano Bilal Haider Abbasi 《Plant Cell, Tissue and Organ Culture》2018,135(2):287-298
Eclipta alba (False daisy) is an important medicinal plant with well-known antihepatotoxic activity. However, no previous in vitro studies are available for its callus culture for increased production of antioxidant secondary metabolites. Herein, we maintained a competent protocol for callus culture of E. alba using stem and leaf explants grown on MS medium containing various concentrations of thidiazuron, 6-benzylaminopurine (BAP) either alone or in association with α-naphthalene acetic acid (NAA). Among all the applied plant growth regulators, BAP along with NAA resulted in maximal dry biomass of 18.0 and 13.8 g/l for stem and leaf explants, respectively. Furthermore, the highest production of phenolics (375.7 mg/l for stem-associated callus and 298 mg/l for leaf-associated callus) and flavonoids (62.0 and 52.3 mg/l for stem- and leaf-associated callus, respectively) were found to be present in optimized callus culture. Antioxidant activity was also elucidated for both stem and leaf derived calli. The highest antioxidant activities (~?93.5%) were witnessed for stem and leaf associated calli at set concentrations of 3.0 mg/l BAP?+?1.0 mg/l NAA and 4.0 mg/l BAP, respectively. High-performance liquid chromatography analyses revealed optimum accumulation of coumarin (1.98 mg/g DW) and wedelolactone (49.63 mg/g DW) in leaf associated callus and desmethylwedelolactone (69.96 mg/g DW), β-amyrin (0.8179 mg/g DW) and eclalbatin (0.3202 mg/g DW) in stem associated callus at optimized concentration. 相似文献
439.
Jake M. Alexander Loïc Chalmandrier Jonathan Lenoir Treena I. Burgess Franz Essl Sylvia Haider Christoph Kueffer Keith McDougall Ann Milbau Martin A. Nuñez Aníbal Pauchard Wolfgang Rabitsch Lisa J. Rew Nathan J. Sanders Loïc Pellissier 《Global Change Biology》2018,24(2):563-579
Rapid climatic changes and increasing human influence at high elevations around the world will have profound impacts on mountain biodiversity. However, forecasts from statistical models (e.g. species distribution models) rarely consider that plant community changes could substantially lag behind climatic changes, hindering our ability to make temporally realistic projections for the coming century. Indeed, the magnitudes of lags, and the relative importance of the different factors giving rise to them, remain poorly understood. We review evidence for three types of lag: “dispersal lags” affecting plant species’ spread along elevational gradients, “establishment lags” following their arrival in recipient communities, and “extinction lags” of resident species. Variation in lags is explained by variation among species in physiological and demographic responses, by effects of altered biotic interactions, and by aspects of the physical environment. Of these, altered biotic interactions could contribute substantially to establishment and extinction lags, yet impacts of biotic interactions on range dynamics are poorly understood. We develop a mechanistic community model to illustrate how species turnover in future communities might lag behind simple expectations based on species’ range shifts with unlimited dispersal. The model shows a combined contribution of altered biotic interactions and dispersal lags to plant community turnover along an elevational gradient following climate warming. Our review and simulation support the view that accounting for disequilibrium range dynamics will be essential for realistic forecasts of patterns of biodiversity under climate change, with implications for the conservation of mountain species and the ecosystem functions they provide. 相似文献
440.
Vigorous knowledge on the occurrence and distribution of toxic metals (TMs) in theenvironment is needed to assess their toxicological impacts on human health especially in developing countries like Pakistan. For the first time, the concentrations of TMs like Ni, Zn, Pb, Cr, and Cd in both ground and surface water and their potential health risk in the district Buner (Pakistan) were determined using Inductive Coupled Plasma Mass Spectrometry (ICP-MS, Agilent Technologies, 7500 CX, USA) and their results were compared with their safe limits defined by Pakistan Environmental Protection Agency (Pak-EPA) and World Health Organization WHO (2008). The concentrations of TMs, like Pb (43% and 86%), Ni (63% and 32%), Cr (41%), and Cd (1% and 20%) in drinking water samples exceeded their respective permissible limits set by Pak-EPA and WHO (2008), respectively. The mean concentrations of TMs were found in decreasing order Ni > Pb > Cr > Cd > Zn. The HRI values of TMs in drinking water samples for both adults and children were observed <1 indicating no health risk to the local population. Excessive marble industries are present in the study area; therefore, it is necessary to reduce metal contamination via proper disposal and treatment of marble wastewater, for which the government should take serious action in the study area. 相似文献