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61.
Natália H Mendes Fernando AF Melo Adolfo CB Santos José RC Pandolfi Elisabete A Almeida Rosilene F Cardoso Henri Berghs Suzana David Faber K Johansen Lívia G Espanha Sergio RA Leite Clarice QF Leite 《BMC research notes》2011,4(1):269
Background
Tuberculosis is a major health problem in São Paulo, Brazil, which is the most populous and one of the most cosmopolitan cities in South America. To characterize the genetic diversity of Mycobacterium tuberculosis in the population of this city, the genotyping techniques of spoligotyping and MIRU were applied to 93 isolates collected in two consecutive years from 93 different tuberculosis patients residing in São Paulo city and attending the Clemente Ferreira Institute (the reference clinic for the treatment of tuberculosis).Findings
Spoligotyping generated 53 different spoligotype patterns. Fifty-one isolates (54.8%) were grouped into 13 spoligotyping clusters. Seventy- two strains (77.4%) showed spoligotypes described in the international databases (SpolDB4, SITVIT), and 21 (22.6%) showed unidentified patterns. The most frequent spoligotype families were Latin American Mediterranean (LAM) (26 isolates), followed by the T family (24 isolates) and Haarlem (H) (11 isolates), which together accounted for 65.4% of all the isolates. These three families represent the major genotypes found in Africa, Central America, South America and Europe. Six Spoligo-International-types (designated SITs by the database) comprised 51.8% (37/72) of all the identified spoligotypes (SIT53, SIT50, SIT42, SIT60, SIT17 and SIT1). Other SITs found in this study indicated the great genetic diversity of M. tuberculosis, reflecting the remarkable ethnic diversity of São Paulo city inhabitants. The MIRU technique was more discriminatory and did not identify any genetic clusters with 100% similarity among the 93 isolates. The allelic analysis showed that MIRU loci 26, 40, 23 and 10 were the most discriminatory. When MIRU and spoligotyping techniques were combined, all isolates grouped in the 13 spoligotyping clusters were separated.Conclusions
Our data indicated the genomic stability of over 50% of spoligotypes identified in São Paulo and the great genetic diversity of M. tuberculosis isolates in the remaining SITs, reflecting the large ethnic mix of the São Paulo city inhabitants. The results also indicated that in this city, M. tuberculosis isolates acquired drug resistance independently of genotype and that resistance was more dependent on the selective pressure of treatment failure and the environmental circumstances of patients.62.
ISOLDA LUNA‐VEGA J. DANIEL TEJERO‐DÍEZ RAÚL CONTRERAS‐MEDINA MICHAEL HEADS GERARDO RIVAS 《Biological journal of the Linnean Society. Linnean Society of London》2012,106(4):940-955
We analyzed the geographical and elevational distributions of two Polypodium complexes from Mexico and Central America. Distribution data of nine species of the Polypodium colpodes complex and the Polypodium plesiosorum complex were obtained from almost 1500 herbarium specimens, field collections in Mexico and Costa Rica, and literature studies. The presence of each species was recorded for each Mesoamerican country, in 1° × 1° grid‐cells and biogeographical provinces. The rarity of species was also evaluated. Although the two complexes show extensive overlap, the P. colpodes complex is distributed mainly along the Pacific versant of Mexico and Central America, whereas the P. plesiosorum complex occurs mainly along the Atlantic versant. Those biogeographical provinces with maximum species diversity are Chiapas (seven species), Sierra Madre del Sur (six species), and the Trans‐Mexican Volcanic belt (six species). Grid‐cells with more species are located mainly in the mountains of central‐southern Mexico and northern Central America. Richness does not decrease or increase with latitude. Elevation distributions showed that most Polypodium species are concentrated in the montane interval and three species groups were recognized based on elevational preferences. Polypodium colpodes and P. plesiosorum are the most widely distributed species, whereas Polypodium castaneum and Polypodium flagellare are the only two species that possess the three attributes of rarity (narrow geographical distribution, high habitat specificity, and scarce local populations). Polypodium species of both complexes are present mainly in the montane regions of the study area and show some degree of geographical sympatry, especially in southern Mexico and northern Central America. This overlapping is explained by the elevation tolerance within montane systems and because most species inhabit three or more vegetation types. The distributional patterns of these complexes coincided with the three regional highlands of Mesoamerica, which are separated from each other by the Isthmus of Tehuantepec and by the lowlands of Nicaragua. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??. 相似文献
63.
64.
BAM receptors regulate stem cell specification and organ development through complex interactions with CLAVATA signaling 总被引:3,自引:1,他引:2
The CLAVATA1 (CLV1) receptor kinase regulates stem cell specification at shoot and flower meristems of Arabidopsis. Most clv1 alleles are dominant negative, and clv1 null alleles are weak in phenotype, suggesting additional receptors functioning in parallel. We have identified two such parallel receptors, BAM1 and BAM2. We show that the weak nature of the phenotype of clv1 null alleles is dependent on BAM activity, with bam clv mutants exhibiting severe defects in stem cell specification. Furthermore, BAM activity in the meristem depends on CLV2, which is required in part for CLV1 function. In addition, clv1 mutants enhance many of the Bam− organ phenotypes, indicating that, contrary to current understanding, CLV1 function is not specific to the meristem. CLV3 encodes a small, secreted peptide that acts as the ligand for CLV1. Mutations in clv3 lead to increased stem cell accumulation. Surprisingly, bam1 and bam2 mutants suppress the phenotype of clv3 mutants. We speculate that in addition to redundant function in the meristem center, BAM1 and BAM2 act to sequester CLV3-like ligands in the meristem flanks. 相似文献
65.
Influenza exposure in United States feral swine populations 总被引:1,自引:0,他引:1
Hall JS Minnis RB Campbell TA Barras S Deyoung RW Pabilonia K Avery ML Sullivan H Clark L McLean RG 《Journal of wildlife diseases》2008,44(2):362-368
Swine play an important role in the disease ecology of influenza. Having cellular receptors in common with birds and humans, swine provide opportunities for mixed infections and potential for genetic reassortment between avian, human, and porcine influenza. Feral swine populations are rapidly expanding in both numbers and range and are increasingly coming into contact with waterfowl, humans, and agricultural operations. In this study, over 875 feral swine were sampled from six states across the United States for serologic evidence of exposure to influenza. In Oklahoma, Florida, and Missouri, USA, no seropositive feral swine were detected. Seropositive swine were detected in California, Mississippi, and Texas, USA. Antibody prevalences in these states were 1% in Mississippi, 5% in California, and 14.4% in Texas. All seropositive swine were exposed to H3N2 subtype, the predominant subtype currently circulating in domestic swine. The only exceptions were in San Saba County, Texas, where of the 15 seropositive samples, four were positive for H1N1 and seven for both H1N1 and H3N2. In Texas, there was large geographical and temporal variation in antibody prevalence and no obvious connection to domestic swine operations. No evidence of exposure to avian influenza in feral swine was uncovered. From these results it is apparent that influenza in feral swine poses a risk primarily to swine production operations. However, because feral swine share habitat with waterfowl, prey on and scavenge dead and dying birds, are highly mobile, and are increasingly coming into contact with humans, the potential for these animals to become infected with avian or human influenza in addition to swine influenza is a distinct possibility. 相似文献
66.
Lumeng CN Deyoung SM Saltiel AR 《American journal of physiology. Endocrinology and metabolism》2007,292(1):E166-E174
Obesity leads to a proinflammatory state with immune responses that include infiltration of adipose tissue with macrophages. These macrophages are believed to alter insulin sensitivity in adipocytes, but the mechanisms that underlie this effect have not been characterized. We have explored the interaction between macrophages and adipocytes in the context of both indirect and direct coculture. Macrophage-secreted factors blocked insulin action in adipocytes via downregulation of GLUT4 and IRS-1, leading to a decrease in Akt phosphorylation and impaired insulin-stimulated GLUT4 translocation to the plasma membrane. GLUT1 was upregulated with a concomitant increase in basal glucose uptake. These changes recapitulate those seen in adipose tissue from insulin-resistant humans and animal models. TNF-alpha-neutralizing antibodies partially reversed the insulin resistance produced by macrophage-conditioned media. Peritoneal macrophages and macrophage-enriched stromal vascular cells from adipose tissue also attenuated responsiveness to insulin in a manner correlating with inflammatory cytokine secretion. Adipose tissue macrophages from obese mice have an F4/80(+)CD11b(+)CD68(+)CD14(-) phenotype and form long cellular extensions in culture. Peritoneal macrophages take on similar characteristics in direct coculture with adipocytes and induce proinflammatory cytokines, suggesting that macrophage activation state is influenced by contact with adipocytes. Thus both indirect/secreted and direct/cell contact-mediated factors derived from macrophages influence insulin sensitivity in adipocytes. 相似文献
67.
Olga Obrezanova Andreas Arnell Ramón Gómez de la Cuesta Maud E Berthelot Thomas RA Gallagher Jesús Zurdo Yvette Stallwood 《MABS-AUSTIN》2015,7(2):352-363
Aggregation is a common problem affecting biopharmaceutical development that can have a significant effect on the quality of the product, as well as the safety to patients, particularly because of the increased risk of immune reactions. Here, we describe a new high-throughput screening algorithm developed to classify antibody molecules based on their propensity to aggregate. The tool, constructed and validated on experimental aggregation data for over 500 antibodies, is able to discern molecules with a high aggregation propensity as defined by experimental criteria relevant to bioprocessing and manufacturing of these molecules. Furthermore, we show how this tool can be combined with other computational approaches during early drug development to select molecules with reduced risk of aggregation and optimal developability properties. 相似文献
68.
Protein phosphatase 2A (PP2A) is a heterotrimeric complex comprising a catalytic, scaffolding, and regulatory subunit. The regulatory subunits are essential for substrate specificity and localization of the complex and are classified into B/B55, B'', and B” non-related families in higher plants. In Arabidopsis thaliana, the close paralogs B''η, B''θ, B''γ, and B''ζ were further classified into a subfamily of B'' called B''η. Here we present results that consolidate the evidence for a role of the B''η subfamily in regulation of innate immunity, energy metabolism and flowering time. Proliferation of the virulent Pseudomonas syringae in B''θ knockout mutant decreased in comparison with wild type plants. Additionally, B''θ knockout plants were delayed in flowering, and this phenotype was supported by high expression of FLC (FLOWERING LOCUS C). B''ζ knockout seedlings showed growth retardation on sucrose-free medium, indicating a role for B''ζ in energy metabolism. This work provides insight into functions of the B''η subfamily members, highlighting their regulation of shared physiological traits while localizing to distinct cellular compartments. 相似文献
69.
A systematic comparative and structural analysis of protein phosphorylation sites based on the mtcPTM database 下载免费PDF全文
mtcPTM is an online repository of human and mouse phosphosites in which data are hierarchically organized to preserve biologically
relevant experimental information, thus allowing straightforward comparisons of phosphorylation patterns found under different
conditions. The database also contains the largest available collection of atomic models of phosphorylatable proteins. Detailed
analysis of this structural dataset reveals that phosphorylation sites are found in a heterogeneous range of structural and
sequence contexts. mtcPTM is available on the web . 相似文献
70.
Phylogenetic analyses of the rbcL sequences from haptophytes and heterokont algae suggest their chloroplasts are unrelated 总被引:2,自引:0,他引:2
Using the large subunit of RuBisCo (rbcL) sequences from cyanobacteria,
proteobacteria, and diverse groups of algae and green plants, we evaluated
the plastid relationship between haptophytes and heterokont algae. The rbcL
sequences were determined from three taxa of heterokont algae
(Bumilleriopsis filiformis, Pelagomonas calceolata, and Pseudopedinella
elastica) and added to 25 published sequences to obtain a data set
comprising 1,434 unambiguously aligned sites (approximately 98% of the
total rbcL gene). Higher levels of mutational saturation in third codon
positions were observed by plotting the pairwise substitutions with and
without corrections for multiple substitutions at the same site for first
and second codon positions only and for third positions only. In accordance
with this finding phylogeny reconstructions were completed by omitting
third codon positions, thus using 956 bp in weighted-parsimony and
maximum-likelihood analyses. The midpoint-rooted phylogenies showed two
major clusters, one containing cyanobacteria, glaucocystophytes, a
phototrophic euglenoid, chlorophytes, and embryophytes (the green lineage),
the other containing proteobacteria, haptophytes, red algae, a cryptophyte,
and heterokont algae (the non-green lineage). In the nongreen lineage, the
haptophytes formed a sister group to the clade containing heterokont algae,
red algae, and the cryptophyte Guillardia theta. This branching pattern was
well supported in terms of bootstrap values in weighted- parsimony and
maximum-likelihood analyses (100% and 92%, respectively). However, the
phylogenetic relationship among red algae, heterokonts, and a cryptophyte
taxon was not especially well resolved. A four- cluster analysis was
performed to further explore the statistical significance of the
relationship between proteobacteria, red algae (including and excluding
Guillardia theta), haptophytes, and heterokont algae. This test strongly
favored the hypothesis that the heterokonts and red algae are more closely
related to each other than either is to proteobacteria or haptophytes.
Hence, this molecular study based on a plastid-encoded gene provides
additional evidence for a distant relationship between haptophytes and the
heterokont algae. It suggests an evolutionary scenario in which the
ancestor of the haptophyte lineage engulfed a phototrophic eukaryote and,
more recently, the heterokont lineage became phototrophic by engulfing a
red alga.
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