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101.
Reciprocal mouse and human limb phenotypes caused by gain- and loss-of-function mutations affecting Lmbr1 总被引:3,自引:0,他引:3
Clark RM Marker PC Roessler E Dutra A Schimenti JC Muenke M Kingsley DM 《Genetics》2001,158(2):715-726
An intensive linkage map of the yellow fever mosquito, Aedes aegypti, was constructed using single-strand conformation polymorphism (SSCP) analysis of cDNA markers to identify single nucleotide polymorphisms (SNPs). A total of 94 A. aegypti cDNAs were downloaded from GenBank and primers were designed to amplify fragments <500 bp in size. These primer pairs amplified 94 loci, 57 (61%) of which segregated in a single F(1) intercross family among 83 F(2) progeny. This allowed us to produce a dense linkage map of one marker every 2 cM distributed over a total length of 134 cM. Many A. aegypti cDNAs were highly similar to genes in the Drosophila melanogaster genome project. Comparative linkage analysis revealed areas of synteny between the two species. SNP polymorphisms are abundant in A. aegypti genes and should prove useful in both population genetics and mapping studies. 相似文献
102.
Immobilization of pneumococcal polysaccharide vaccine on silicon oxide wafer for an acoustical biosensor. 总被引:2,自引:0,他引:2
R F Dutra C M Castro C R Azevedo E Vinhas E Malague?o E H Melo J L Lima Filho J F Kennedy 《Biosensors & bioelectronics》2000,15(9-10):511-514
One the most important aspects of a biosensor is related to immobilization and maintenance of specific reference compounds on sensing surfaces. A method for the immobilization of polysaccharides to a silicon oxide surface intended for Surface Acoustical Waves (SAW) sensors is described. Silicon oxide is a hydrophobic inorganic support used for the fabrication of many electronic devices. The pneumococcal polysaccharide (PPS) vaccine is immobilized via Protein A after pre-treatment of the surface with hydrochloric acid. The effects of non-specific binding are discussed. The results indicate that the immobilization of PPS via Protein A increases the sensitivity of detecting Streptococcus pneumoniae antibodies in human sera and offers greater reproducibility of response compared with ELISA methods. The principles of this technique are simple and are applicable to the immobilization of many capsular polysaccharides. 相似文献
103.
Victor Satler Pylro André Luiz Moreira de Freitas Wagner Campos Otoni Ivo Ribeiro da Silva Arnaldo Chaer Borges Maurício Dutra Costa 《PloS one》2013,8(7)
Ectomycorrhizal fungi are ubiquitous in forest ecosystems, benefitting plants principally by increasing the uptake of water and nutrients such as calcium from the soil. Previous work has demonstrated accumulation of crystallites in eucalypt ectomycorrhizas, but detailed morphological and chemical characterization of these crystals has not been performed. In this work, cross sections of acetic acid-treated and cleared ectomycorrhizal fragments were visualized by polarized light microscopy to evaluate the location of crystals within cortical root cells. Ectomycorrhizal sections were also observed by scanning electron microscopy (SEM) coupled with energy dispersive x-ray (EDS) microprobe analysis. The predominant forms of crystals were crystal sand (granules) and concretions. Calcium, carbon and oxygen were detected by EDS as constituent elements and similar elemental profiles were observed between both crystal morphologies. All analyzed crystalline structures were characterized as calcium oxalate crystals. This is the first report of the stoichiometry and morphology of crystals occurring in eucalypt ectomycorrhizas in tropical soils. The data corroborates the role of ectomycorrhizae in the uptake and accumulation of calcium in the form of calcium oxalate crystals in hybrid eucalypt plants. 相似文献
104.
105.
Daniela de Angeli Dutra Antoine Filion Alan Fecchio Érika Martins Braga Robert Poulin 《Oikos》2021,130(6):979-988
Migration has an important impact on the transmission of pathogens. Migratory birds disperse parasites through their routes and may consequently introduce them to new areas and hosts. Hence, haemosporidian parasites, which are among the most prevalent, diverse and important bird pathogens, are potentially dispersed when infecting migrant hosts. Further, migrant hosts could enhance local parasite prevalence and richness by transporting new parasite strains to new areas. Here, we hypothesize and aim to evaluate if 1) migratory birds spread parasite lineages along their routes, and 2) localities crossed by more migratory birds have greater prevalence and richness of haemosporidians. For the first hypothesis, we tested whether parasite lineages found 1) in both migrants and residents, and 2) only in residents, differ in their frequencies of occurrence among localities. For the second hypothesis, we tested for a relationship among localities between the overall local haemosporidian parasite richness and prevalence, and the proportion of migratory bird individuals present in a locality. We combined a dataset on 13 200 bird samples with additional data from the MalAvi database (total: ~2800 sequenced parasites comprising 675 distinct lineages, from 506 host species and 156 localities) from South America, and used Bayesian multi-level models to test our hypotheses. We demonstrate that parasites shared between resident and migratory species are the most spatially widespread, highlighting the potential of migrants to carry and transmit haemosporidians. Further, the presence of migrants in a locality was negatively related to local parasite richness, but not associated with local prevalence. Here, we confirm that migrants can contribute to parasite dispersal and visiting migrants are present in regions with lower Plasmodium prevalence. Also, we observed their presence might raise Haemoproteus community prevalence. Therefore, we demonstrate migrants enhance pathogens spread and their presence may influence parasite community transmission. 相似文献
106.
Suzana Vieira Rabêlo Fernanda Granja da Silva Oliveira Michele Miriam Calixto de Lira Livia Macedo Dutra Adilson Sartoratto Marta Cristina Teixeira Duarte Maria Claudia dos Santos Luciano Maria Francilene Souza Silva Cláudia do Ó Pessoa Manoel Odorico de Moraes Filho Emmanoel Vilaça Costa Jackson Roberto Guedes da Silva Almeida 《Phyton》2021,90(3):921-931
This study aimed to identify the chemical composition of essential oil from fruits (EOAF) and the hexanic crude
extract from aerial parts (At-Hex) of atemoya (Annona cherimola x Annona squamosa), a hybrid belonging to the
Annonaceae family. Cytotoxic and antimicrobial activity was also evaluated. OEAF was obtained by hydrodistillation using a Clevenger apparatus, and their composition was analyzed by gas chromatography-mass spectrometry
(GC-MS) analyses. Cytotoxicity was tested against human tumor cell lines HCT-116 (colon carcinoma), SF-295
(glioblastoma), OVCAR-8 (ovarian carcinoma) and HL60 (leukemia) using 3-(4,5-dimethyl-2-thiazolyl)-2,5-
diphenyl-2H-tetrazolium bromide (MTT) assay, while antimicrobial activity was conducted by bioauthography
method against eleven microorganisms strains. Twenty-four compounds were identified in the EOAF and
twenty-nine in At-Hex. The monoterpenes linalool (25.70%), α-pinene (10.38%), β-pinene (9.12%), transocimene (7.43%), and the sesquiterpene bicyclogermacrene (12.58%) were the major constituents of EOAF,
whereas the sesquiterpene spathulenol (13.91%) was the main compound of At-Hex. At-Hex showed a high
cytotoxicity against SF-295 (glioblastoma). These findings show an important chemotaxonomic contribution
for the Annonaceae family, mainly for the Annona genus. Atemoya proved to be a promising source of substances
with potential cytotoxic activity. 相似文献
107.
de Mendonça JD Adachi O Rosado LA Ducati RG Santos DS Basso LA 《Molecular bioSystems》2011,7(1):119-128
The number of new cases of tuberculosis (TB) arising each year is increasing globally. Migration, socio-economic deprivation, HIV co-infection and the emergence of drug-resistant strains of Mycobacterium tuberculosis, the main causative agent of TB in humans, have all contributed to the increasing number of TB cases worldwide. Proteins that are essential to the pathogen survival and absent in the host, such as enzymes of the shikimate pathway, are attractive targets to the development of new anti-TB drugs. Here we describe the metal requirement and kinetic mechanism determination of M. tuberculosis dehydroquinate synthase (MtDHQS). True steady-state kinetic parameters determination and ligand binding data suggested that the MtDHQS-catalyzed chemical reaction follows a rapid-equilibrium random mechanism. Treatment with EDTA abolished completely the activity of MtDHQS, and addition of Co(2+) and Zn(2+) led to, respectively, full and partial recovery of the enzyme activity. Excess Zn(2+) inhibited the MtDHQS activity, and isotitration microcalorimetry data revealed two sequential binding sites, which is consistent with the existence of a secondary inhibitory site. We also report measurements of metal concentrations by inductively coupled plasma atomic emission spectrometry. The constants of the cyclic reduction and oxidation of NAD(+) and NADH, respectively, during the reaction of MtDHQS was monitored by a stopped-flow instrument, under single-turnover experimental conditions. These results provide a better understanding of the mode of action of MtDHQS that should be useful to guide the rational (function-based) design of inhibitors of this enzyme that can be further evaluated as anti-TB drugs. 相似文献
108.
109.
Ana Paula Carneiro Salgado Jamária Adriana Pinheiro Soares-Martins Luciana Garcia Andrade Jonas Dutra Albarnaz Paulo César Peregrino Ferreira Erna Geessien Kroon Cláudio Ant?nio Bonjardim 《Memórias do Instituto Oswaldo Cruz》2013,108(5):554-562
Interfering with cellular signal transduction pathways is a common
strategy used by many viruses to create a propitious intracellular environment
for an efficient replication. Our group has been studying cellular signalling
pathways activated by the orthopoxviruses Vaccinia (VACV) and Cowpox (CPXV) and
their significance to viral replication. In the present study our aim was to
investigate whether the GTPase Rac1 was an upstream signal that led to the
activation of MEK/ERK1/2, JNK1/2 or Akt pathways upon VACV or CPXV'' infections.
Therefore, we generated stable murine fibroblasts exhibiting negative dominance
to Rac1-N17 to evaluate viral growth and the phosphorylation status of ERK1/2,
JNK1/2 and Akt. Our results demonstrated that VACV replication, but not CPXV,
was affected in dominant-negative (DN) Rac1-N17 cell lines in which viral yield
was reduced in about 10-fold. Viral late gene expression, but not early, was
also reduced. Furthermore, our data showed that Akt phosphorylation was
diminished upon VACV infection in DN Rac1-N17 cells, suggesting that Rac1
participates in the phosphoinositide-3 kinase pathway leading to the activation
of Akt. In conclusion, our results indicate that while Rac1 indeed plays a role
in VACV biology, perhaps another GTPase may be involved in CPXV replication. 相似文献
110.
André Moreni Lopes Valéria de Carvalho Santos-Ebinuma Leticia Celia de Lencastre Novaes João Vitor Dutra Molino Leandro Ramos Souza Barbosa Adalberto Pessoa Jr Carlota de Oliveira Rangel-Yagui 《Applied microbiology and biotechnology》2013,97(14):6201-6209
Lipopolysaccharide endotoxins (LPS) are the most common pyrogenic substances in recombinant peptides and proteins purified from Gram-negative bacteria, such as Escherichia coli. In this respect, aqueous two-phase micellar systems (ATPMS) have already proven to be a good strategy to purify recombinant proteins of pharmaceutical interest and remove high LPS concentrations. In this paper, we review our recent experimental work in protein partitioning in Triton X-114 ATPMS altogether with some new results and show that LPS–protein aggregation can influence both protein and LPS partitioning. Green fluorescent protein (GFPuv) was employed as a model protein. The ATPMS technology proved to be effective for high loads of LPS removal into the micelle-rich phase (%REMLPS?>?98 %) while GFPuv partitioned preferentially to the micelle-poor phase (K GFPuv?<?1.00) due to the excluded-volume interactions. However, theoretically predicted protein partition coefficient values were compared with experimentally obtained ones, and good agreement was found only in the absence of LPS. Dynamic light scattering measurements showed that protein–LPS interactions were taking place and influenced the partitioning process. We believe that this phenomenon should be considered in LPS removal employing any kind of aqueous two-phase system. Nonetheless, ATPMS can still be considered as an efficient strategy for high loads of LPS removal, but being aware that the excluded-volume partitioning theory available might overestimate partition coefficient values due to the presence of protein–LPS aggregation. 相似文献