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11.
Biological Effects of Insulin and Its Analogs on Cancer Cells With Different Insulin Family Receptor Expression
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12.
Nine white-rot fungal strains were screened for biodecolourization of brilliant green, cresol red, crystal violet, congo red
and orange II. Dichomitus squalens, Phlebia fascicularia and P. floridensis decolourized all of the dyes on solid agar medium and possessed better decolourization ability than Phanerochaete chrysosporium when tested in nitrogen-limited broth medium. Journal of Industrial Microbiology & Biotechnology (2002) 28, 201–203 DOI: 10.1038/sj/jim/7000222
Received 12 July 2001/ Accepted in revised form 22 October 2001 相似文献
13.
Phylogenetic evidence for horizontal transmission of group I introns in the nuclear ribosomal DNA of mushroom-forming fungi 总被引:7,自引:3,他引:4
Group I introns were discovered inserted at the same position in the
nuclear small-subunit ribosomal DNA (nuc-ssu-rDNA) in several species of
homobasidiomycetes (mushroom-forming fungi). Based on conserved intron
sequences, a pair of intron-specific primers was designed for PCR
amplification and sequencing of intron-containing rDNA repeats. Using the
intron-specific primers together with flanking rDNA primers, a PCR assay
was conducted to determine presence or absence of introns in 39 species of
homobasidiomycetes. Introns were confined to the genera Panellus,
Clavicorona, and Lentinellus. Phylogenetic analyses of nuc-ssu-rDNA and
mitochondrial ssu-rDNA sequences suggest that Clavicorona and Lentinellus
are closely related, but that Panellus is not closely related to these. The
simplest explanation for the distribution of the introns is that they have
been twice independently gained via horizontal transmission, once on the
lineage leading to Panellus, and once on the lineage leading to Lentinellus
and Clavicorona. BLAST searches using the introns from Panellus and
Lentinellus as query sequences retrieved 16 other similar group I introns
of nuc-ssu-rDNA and nuclear large-subunit rDNA (nuc-lsu-rDNA) from fungal
and green algal hosts. Phylogenetic analyses of intron sequences suggest
that the mushroom introns are monophyletic, and are nested within a clade
that contains four other introns that insert at the same position as the
mushroom introns, two from different groups of fungi and two from green
algae. The distribution of host lineages and insertion sites among the
introns suggests that horizontal and vertical transmission, homing, and
transposition have been factors in intron evolution. As distinctive,
heritable features of nuclear rDNAs in certain lineages, group I introns
have promise as phylogenetic markers. Nevertheless, the possibility of
horizontal transmission and homing also suggest that their use poses
certain pitfalls.
相似文献
14.
Pim van Hooft Herbert HT Prins Wayne M Getz Anna E Jolles Sipke E van Wieren Barend J Greyling Paul D van Helden Armanda DS Bastos 《BMC evolutionary biology》2010,10(1):106
Background
The Y-chromosomal diversity in the African buffalo (Syncerus caffer) population of Kruger National Park (KNP) is characterized by rainfall-driven haplotype frequency shifts between year cohorts. Stable Y-chromosomal polymorphism is difficult to reconcile with haplotype frequency variations without assuming frequency-dependent selection or specific interactions in the population dynamics of X- and Y-chromosomal genes, since otherwise the fittest haplotype would inevitably sweep to fixation. Stable Y-chromosomal polymorphism due one of these factors only seems possible when there are Y-chromosomal distorters of an equal sex ratio, which act by negatively affecting X-gametes, or Y-chromosomal suppressors of a female-biased sex ratio. These sex-ratio (SR) genes modify (suppress) gamete transmission in their own favour at a fitness cost, allowing for stable polymorphism. 相似文献15.
Rosemary J Redfield Wendy A Findlay Janine Bossé J Simon Kroll Andrew DS Cameron John HE Nash 《BMC evolutionary biology》2006,6(1):82-15
Background
Many bacteria can take up DNA, but the evolutionary history and function of natural competence and transformation remain obscure. The sporadic distribution of competence suggests it is frequently lost and/or gained, but this has not been examined in an explicitly phylogenetic context. Additional insight may come from the sequence specificity of uptake by species such as Haemophilus influenzae, where a 9 bp uptake signal sequence (USS) repeat is both highly overrepresented in the genome and needed for efficient DNA uptake. We used the distribution of competence genes and DNA uptake specificity in H. influenzae 's family, the Pasteurellaceae, to examine the ancestry of competence. 相似文献16.
Repeated evolution of an acetate-crossfeeding polymorphism in long-term populations of Escherichia coli 总被引:1,自引:0,他引:1
Six out of 12 independent replicate populations of Escherichia coli
maintained in long-term glucose-limited continuous culture for up to
approximately 1,750 generations evolve polymorphisms maintained by acetate
crossfeeding. In all cases, the acetate-crossfeeding phenotype is
associated with semiconstitutive overexpression of acetyl CoA synthetase,
which allows for the enhanced uptake of low levels of exogenous acetate.
Mutations in the 5' regulatory region of the acetyl CoA synthetase locus
are responsible for all the acetate crossfeeding phenotypes found. These
changes were either transposable-element insertions or a single T-->A
nucleotide substitution at position -93 relative to the acs gene
translation start site.
相似文献
17.
Background
Extensive focus is placed on the comparative analyses of consensus genotypes in the study of West Nile virus (WNV) emergence. Few studies account for genetic change in the underlying WNV quasispecies population variants. These variants are not discernable in the consensus genome at the time of emergence, and the maintenance of mutation-selection equilibria of population variants is greatly underestimated. The emergence of lineage 1 WNV strains has been studied extensively, but recent epidemics caused by lineage 2 WNV strains in Hungary, Austria, Greece and Italy emphasizes the increasing importance of this lineage to public health. In this study we explored the quasispecies dynamics of minority variants that contribute to cell-tropism and host determination, i.e. the ability to infect different cell types or cells from different species from Next Generation Sequencing (NGS) data of a historic lineage 2 WNV strain.Results
Minority variants contributing to host cell membrane association persist in the viral population without contributing to the genetic change in the consensus genome. Minority variants are shown to maintain a stable mutation-selection equilibrium under positive selection, particularly in the capsid gene region.Conclusions
This study is the first to infer positive selection and the persistence of WNV haplotype variants that contribute to viral fitness without accompanying genetic change in the consensus genotype, documented solely from NGS sequence data. The approach used in this study streamlines the experimental design seeking viral minority variants accurately from NGS data whilst minimizing the influence of associated sequence error. 相似文献18.
Parent presence, delayed dispersal, and territory acquisition in the Seychelles warbler 总被引:1,自引:0,他引:1
The presence of parents in the natal territory may play an important,but often overlooked, role in natal dispersal and the consequentacquisition of a territory. Living with parents in a territorymay confer a fitness advantage to subordinates through, forexample, the nepotistic behavior of the parents or indirectbenefits gained by helping to raise nondescendent kin. Whena parent is replaced by a stepparent, such advantages are reducedor disappear and, as a result, subordinates may disperse. Subordinatesthat disperse after parent replacement may be constrained intheir timing of dispersal, which could have negative fitnessconsequences. In the cooperatively breeding Seychelles warbler,we show that when a parent was naturally replaced or experimentallyremoved and subsequently replaced by a stepparent from outsidethe territory, subordinates were more likely to disperse thanwhen both parents remained in the natal territory. Furthermore,subordinates dispersing from territories in which one or bothparents had been replaced were less likely to acquire a breederposition than subordinates dispersing when both parents werestill on the natal territory. Our findings suggest that thepresence of parents in the natal territory may promote delayeddispersal and facilitate the eventual acquisition of a breederposition outside the natal territory. Our results support theidea that the prolonged parental care, which long-lived speciesare able to provide, may have selected for family living. 相似文献
19.
Marica Cassarino Katie Robinson Dominic Trpel Íde OShaughnessy Eimear Smalle Stephen White Collette Devlin Rosie Quinn Fiona Boland Marie E. Ward Rosa McNamara Fiona Steed Margaret OConnor Andrew ORegan Gerard McCarthy Damien Ryan Rose Galvin 《PLoS medicine》2021,18(7)
BackgroundOlder adults frequently attend the emergency department (ED) and experience high rates of adverse events following ED presentation. This randomised controlled trial evaluated the impact of early assessment and intervention by a dedicated team of health and social care professionals (HSCPs) in the ED on the quality, safety, and clinical effectiveness of care of older adults in the ED.Methods and findingsThis single-site randomised controlled trial included a sample of 353 patients aged ≥65 years (mean age = 79.6, SD = 7.01; 59.2% female) who presented with lower urgency complaints to the ED a university hospital in the Mid-West region of Ireland, during HSCP operational hours. The intervention consisted of early assessment and intervention carried out by a HSCP team comprising a senior medical social worker, senior occupational therapist, and senior physiotherapist. The primary outcome was ED length of stay. Secondary outcomes included rates of hospital admissions from the ED; hospital length of stay for admitted patients; patient satisfaction with index visit; ED revisits, mortality, nursing home admission, and unscheduled hospital admission at 30-day and 6-month follow-up; and patient functional status and quality of life (at index visit and follow-up). Demographic information included the patient’s gender, age, marital status, residential status, mode of arrival to the ED, source of referral, index complaint, triage category, falls, and hospitalisation history. Participants in the intervention group (n = 176) experienced a significantly shorter ED stay than the control group (n = 177) (6.4 versus 12.1 median hours, p < 0.001). Other significant differences (intervention versus control) included lower rates of hospital admissions from the ED (19.3% versus 55.9%, p < 0.001), higher levels of satisfaction with the ED visit (p = 0.008), better function at 30-day (p = 0.01) and 6-month follow-up (p = 0.03), better mobility (p = 0.02 at 30 days), and better self-care (p = 0.03 at 30 days; p = 0.009 at 6 months). No differences at follow-up were observed in terms of ED re-presentation or hospital admission. Study limitations include the inability to blind patients or ED staff to allocation due to the nature of the intervention, and a focus on early assessment and intervention in the ED rather than care integration following discharge.ConclusionsEarly assessment and intervention by a dedicated ED-based HSCP team reduced ED length of stay and the risk of hospital admissions among older adults, as well as improving patient satisfaction. Our findings support the effectiveness of an interdisciplinary model of care for key ED outcomes.Trial registrationClinicalTrials.gov ; registered on 12 November 2018.Marica Cassarino and colleagues evaluate an intervention for early assessment of older patients in emergency care. NCT03739515相似文献
20.
R H Swerdlow J K Parks D S Cassarino A T Shilling J P Bennett M B Harrison W D Parker 《Biochemical and biophysical research communications》1999,261(3):701-704
Electron transport chain (ETC) dysfunction may arise from mitochondrial genetic, nuclear genetic, or toxic etiologies. Cytoplasmic hybrid (cybrid) systems can help distinguish between these possibilities by facilitating expression of suspect mitochondrial DNA (mtDNA) within a nuclear and environmentally controlled context. Perpetuation of ETC dysfunction in cybrids is consistent with an mtDNA pathogenesis while defect correction is not. We previously used cybrids to screen sporadic Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis patients for mtDNA mutation with positive results. To further address the fidelity of these experiments, we created and characterized cybrids expressing mtDNA from persons with Huntington's disease (HD), an autosomal dominant, nuclear DNA-determined disorder in which mitochondrial ETC functioning is abnormal. On ETC, oxidative stress, and calcium homeostasis assays HD cybrid lines were indistinguishable from control cybrid lines. These data support the use of the cybrid technique for mtDNA mutation screening in candidate diseases. 相似文献