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排序方式: 共有152条查询结果,搜索用时 15 毫秒
51.
Lovato DV Amino R González Y Miranda A Schenkman S Tanaka AS 《Experimental parasitology》2011,129(4):362-367
Infestins are Kazal-type serine protease inhibitors described in the midgut of Triatoma infestans, Chagas disease vector. Of all infestins, only infestin 1R (INF1R) does not control host blood coagulation, due to its inhibitory specificity for chymotrypsin-like proteases. We further investigated the effect of INF1R on cell infection by Trypanosoma cruzi. The importance of INF1R reactive site to inhibit T. cruzi cell invasion was confirmed using 1RSFTI, a synthetic cyclic peptide containing the inhibitor reactive site region hybridized to the Sunflower Trypsin Inhibitor-1 (SFTI-1). Our results suggest that INF1R efficiently inhibited parasite cell invasion. For the first time, a serine protease inhibitor, derived from T. infestans, was shown to impair cell invasion by T. cruzi, representing possible new target in parasite cell invasion. 相似文献
52.
Objectives: The purpose of this study was to evaluate biofilm distribution over internal and external surfaces of upper complete dentures. It was also aimed at assessing the effect of oral hygiene instructions before and after home use of a disclosing solution. Materials and methods: The sample consisted of 29 complete denture wearers whose upper prostheses were evaluated. Surface biofilm was disclosed by means of a 1% neutral red solution and quantified with regard to internal and external surfaces. Oral hygiene information was provided on an individual basis. During the second stage, an amount of disclosing solution was given for domestic use. Results: Internal and external surfaces presented a similar amount of biofilm, which was concentrated over the area of the posterior teeth area, palatal rugae and the internal vestibular incline of the distobuccal flange. This pattern was maintained during the study. However, overall amounts were reduced following denture hygiene information. The use of disclosing solution by subjects at home resulted in a further reduction. Conclusions: It was concluded that biofilm deposits were similar over assessed surfaces, regardless of the type of procedure but irregular areas presented greater amounts. Oral health instruction was effective in reducing the biofilm, in particular when associated with home use of a disclosing agent. 相似文献
53.
Sasaki SD de Lima CA Lovato DV Juliano MA Torquato RJ Tanaka AS 《Experimental parasitology》2008,118(2):214-220
BmSI-7 and BmSI-6, two Boophilus microplus subtilisin inhibitors (BmSI) were purified and characterized from eggs. The inhibitors isolated by classical purification methods presented molecular masses of 7408 and 7271Da, respectively, by MALDI-TOF-MS. Both BmSI-7 and BmSI-6 inhibited neutrophil elastase (K(i) 0.4 and 0.3nM) and subtilisin A (K(i) 1.4nM for both inhibitors). They also strongly inhibited Pr1 proteases from the fungus Metarhizium anisopliae; BmSI-7 (K(i) 50nM) and BmSI-6 (K(i) 2.2nM). The BmSI-7 full length cDNA was obtained using amino acid sequence information of BmSI-7 peptides generated by proteolytic digestion. BmSI-7 belongs to trypsin inhibitor like cysteine rich domain family (TIL), and it is transcribed in ovary, fat body, gut, salivary gland and haemocytes. BmSI-7 is the first TIL inhibitor described with inhibitory activity toward subtilisin A and Pr1 proteases of entomopathogenic fungi. 相似文献
54.
Moncayo AL Vaca M Amorim L Rodriguez A Erazo S Oviedo G Quinzo I Padilla M Chico M Lovato R Gomez E Barreto ML Cooper PJ 《PLoS neglected tropical diseases》2008,2(9):e293
Background
Control of soil-transmitted helminth (STH) infections relies on the periodic and long-term administration of anthelmintic drugs to high-risk groups, particularly school-age children living in endemic areas. There is limited data on the effectiveness of long-term periodic anthelmintic treatment on the prevalence of STHs, particularly from operational programmes. The current study investigated the impact of 15 to 17 years of treatment with the broad-spectrum anthelmintic ivermectin, used for the control of onchocerciasis, on STH prevalence and intensity in school-age and pre-school children.Methods and Findings
A cross-sectional study was conducted in communities that had received annual or twice-annual ivermectin treatments and geographically adjacent communities that had not received treatment in two districts of Esmeraldas Province in Ecuador. Stool samples were collected from school-age children and examined for STH infection using the Kato-Katz and formol-ether concentration methods. Samples were collected also from pre-school children and examined by the formol-ether concentration method. Data on risk factors for STH infection were collected by parental questionnaire. We sampled a total of 3,705 school-age children (6–16 years) from 31 treated and 27 non-treated communities, and 1,701 pre-school children aged 0–5 years from 18 treated and 18 non-treated communities. Among school-age children, ivermectin treatment had significant effects on the prevalence (adjusted OR = 0.06, 95% CI 0.03–0.14) and intensity of Trichuris trichiura infection (adjusted RR = 0.28, 95% CI 0.11–0.70), but appeared to have no impact on Ascaris lumbricoides or hookworm infection. Reduced prevalence and intensities of T. trichiura infection were observed among children not eligible to receive ivermectina, providing some evidence of reduced transmission of T. trichiura infection in communities receiving mass ivermectin treatments.Conclusion
Annual and twice-annual treatments with ivermectin over a period of up to 17 years may have had a significant impact on T. trichiura infection. The present data indicate that the long-term control of onchocerciasis with ivermectin may provide additional health benefits by reducing infections with trichuriasis. The addition of a second anthelmintic drug such as albendazole may be useful for a long-term effect on A. lumbricoides infection. 相似文献55.
Kappa-chain constant-region gene sequences in genus Rattus: coding regions are diverging more rapidly than noncoding regions 总被引:2,自引:0,他引:2
We have determined the nucleotide sequence of a 1,200-base pair (bp)
genomic fragment that includes the kappa-chain constant-region gene (C
kappa) from two species of native Australian rodents, Rattus leucopus
cooktownensis and Rattus colletti. Comparison of these sequences with each
other and with other rodent C kappa genes shows three surprising features.
First, the coding regions are diverging at a rate severalfold higher than
that of the nearby noncoding regions. Second, replacement changes within
the coding region are accumulating at a rate at least as great as that of
silent changes. Third, most of the amino acid replacements are localized in
one region of the C kappa domain--namely, the carboxy-terminal "bends" in
the alpha-carbon backbone. These three features have previously been
described from comparisons of the two allelic forms of C kappa genes in R.
norvegicus. These data imply the existence of considerable evolutionary
constraints on the noncoding regions (based on as yet undetermined
functions) or powerful positive selection to diversify a portion of the
constant-region domain (whose physiological significance is not known).
These surprising features of C kappa evolution appear to be characteristic
only of closely related C kappa genes, since comparison of rodent with
human sequences shows the expected greater conservation of coding regions,
as well as a predominance of silent nucleotide substitutions within the
coding regions.
相似文献
56.
Bruno Leles Anderson V. Chaves Philip Russo Jo?o A. N. Batista Maria Bernadete Lovato 《PloS one》2015,10(3)
Knowledge of the role of Neotropical montane landscapes in shaping genetic connectivity and local adaptation is essential for understanding the evolutionary processes that have shaped the extraordinary species diversity in these regions. In the present study, we examined the landscape genetics, estimated genetic diversity, and explored genetic relationships with morphological variability and reproductive strategies in seven natural populations of Cattleya liliputana (Orchidaceae). Nuclear microsatellite markers were used for genetic analyses. Spatial Bayesian clustering and population-based analyses revealed significant genetic structuring and high genetic diversity (He = 0.733 ± 0.03). Strong differentiation was found between populations over short spatial scales (FST = 0.138, p < 0.001), reflecting the landscape discontinuity and isolation. Monmonier´s maximum difference algorithm, Bayesian analysis on STRUCTURE and principal component analysis identified one major genetic discontinuity between populations. Divergent genetic groups showed phenotypic divergence in flower traits and reproductive strategies. Increased sexual reproductive effort was associated with rock outcrop type and may be a response to adverse conditions for growth and vegetative reproduction. Here we discuss the effect of restricted gene flow, local adaptation and phenotypic plasticity as drivers of population differentiation in Neotropical montane rock outcrops. 相似文献
57.
Expression patterns of the whole troponin C gene repertoire during Drosophila development 总被引:2,自引:0,他引:2
Herranz R Díaz-Castillo C Nguyen TP Lovato TL Cripps RM Marco R 《Gene expression patterns : GEP》2004,4(2):183-190
The success of the genomic sequencing programs allows the discovery of additional family members of genes encoding known functions. This is the case of the Troponin C gene repertoire in Drosophila melanogaster. We have found two new Troponin C genes, DmTpnC41F and DmTpnC25D, increasing to five the total number of Troponin C genes identified in this species. The comparative characterization of the five Troponin C genes in D. melanogaster demonstrates considerable variation in gene structure and expression pattern. Expression of one gene, DmTpnC41F, has more restricted tissue specificity than the rest of the TpnC genes and, with the chromosomically linked DmTpnC41C, is expressed specifically in the adult thorax. The new gene, DmTpnC25D is expressed during development more broadly than the rest. In adults, it is highly expressed in the adult head. Finally, the other two genes, DmTpnC47D and DmTpnC73F, show a high embryonic/larval expression and in adults are expressed almost exclusively in the abdomens. The functional adaptive changes that may have evolved during the expansion of this gene family are briefly discussed in terms of the expression patterns, gene and protein structures leading to a simpler, more systematic nomenclature of the gene family. 相似文献
58.
Background
Helicobacter pylori colonizes the human stomach and is associated with gastritis, peptic ulcer, and gastric cancer. This ubiquitous association between H. pylori and humans is thought to be present since the origin of modern humans. The H. pylori genome encodes for an exceptional number of restriction and modifications (R-M) systems. To evaluate if R-M systems are an adequate tool to determine the geographic distribution of H. pylori strains, we typed 221 strains from Africa, America, Asia, and Europe, and evaluated the expression of different 29 methyltransferases. 相似文献59.
Franc-Christophe Baurens Stéphanie Bocs Mathieu Rouard Takashi Matsumoto Robert NG Miller Marguerite Rodier-Goud Didier MBéguié-A-MBéguié Nabila Yahiaoui 《BMC plant biology》2010,10(1):149
Background
Comparative sequence analysis of complex loci such as resistance gene analog clusters allows estimating the degree of sequence conservation and mechanisms of divergence at the intraspecies level. In banana (Musa sp.), two diploid wild species Musa acuminata (A genome) and Musa balbisiana (B genome) contribute to the polyploid genome of many cultivars. The M. balbisiana species is associated with vigour and tolerance to pests and disease and little is known on the genome structure and haplotype diversity within this species. Here, we compare two genomic sequences of 253 and 223 kb corresponding to two haplotypes of the RGA08 resistance gene analog locus in M. balbisiana "Pisang Klutuk Wulung" (PKW). 相似文献60.
Plathymenia reticulata is a tree species that occurs in two different Brazilian biomes, the Cerrado (a savannah environment), and the Atlantic Forest. In the present study, we evaluated morphological variation within and among five populations located in these vegetation types and in transitional sites in order to test the hypothesis that habitat selective pressures, being different in the Cerrado and the Atlantic Forest, would cause adaptive differences in morphological traits in individuals occurring under these different circumstances. Thirteen morphological traits of fruits, seeds, and of the membranous endocarp were obtained from 30 fruits and 20 seeds from each of nine to 10 individuals per population. Significant variation was found for all traits while comparing individuals within populations, and most traits varied significantly among populations as well. Some traits differed significantly between forest and Cerrado populations, while transition sites showed intermediate patterns and higher within-population variation. Contrary to our hypothesis, variation in seed size and mass among populations from different habitats was not significant. However, as predicted, the membranous endocarp was shorter for the seeds from Cerrado populations than from the Atlantic Forest. These data suggest the existence of P. reticulata ecotypes from Cerrado and Atlantic Forest; the relevance to Plathymenia evolution and to its wide ecological distribution is discussed. 相似文献