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排序方式: 共有169条查询结果,搜索用时 15 毫秒
1.
Rubens Souza de OLIVEIRA Lanna Jamile Corrêa da COSTA Fernanda Atanaena Gon?alves de ANDRADE Wilson UIEDA Luzia Fátima Alves MARTORELLI Ana Paula de Arruda Geraldes KATAOKA Elizabeth Salbé Travassos da ROSA Pedro Fernando da Costa VASCONCELOS Armando de Souza PEREIRA Ant?nio Ismael Barros do CARMO Marcus Emanuel Barroncas FERNANDES 《Revista do Instituto de Medicina Tropical de S?o Paulo》2015,57(6):497-503
The outbreaks of rabies in humans transmitted by Desmodus rotundus in 2004 and 2005,
in the northeast of the Brazilian State of Para, eastern Amazon basin, made this a
priority area for studies on this zoonosis. Given this, the present study provides
data on this phenomenon in an urban context, in order to assess the possible
circulation of the classic rabies virus (RABV) among bat species in Capanema, a town
in the Amazon basin. Bats were collected, in 2011, with mist nets during the wet and
dry seasons. Samples of brain tissue and blood were collected for virological and
serological survey, respectively. None of the 153 brain tissue samples analyzed
tested positive for RABV infection, but 50.34% (95% CI: 45.67-55.01%) of the serum
samples analyzed were seropositive. Artibeus planirostris was the most common
species, with a high percentage of seropositive individuals (52.46%, 95% CI: 52.31
52.60%). Statistically, equal proportions of seropositive results were obtained in
the rainy and dry seasons (c2 = 0.057, d.f. = 1, p = 0.88). Significantly
higher proportions of males (55.96%, 95% CI: 48.96-62.96%) and adults (52.37%, 95%
CI: 47.35-57.39%) were seropositive. While none of the brain tissue samples tested
positive for infection, the high proportion of seropositive specimens indicates that
RABV may be widespread in this urban area. 相似文献
2.
HENDRICKS JERRY D.; CHENG RONSHAN; SHELTON DENNIS W.; PEREIRA CLIFF B.; BAILEY GEORGE S. 《Toxicological sciences》1994,23(1):53-62
While the experimental data upon which current concepts in mechanisticallybased risk assessment and molecular epidemiology are groundedderive almost entirely from rodent models, fish models haveseveral attributes (e.g., low background incidence, extremelylow cost tumor studies, nonmammalian comparative status forextrapolation of mechanisms to humans) that make them valuableadjuncts for addressing these concepts. This report providesan initial characterization of the dose dependency of dietaryN-nitrosodiethylamine (DEN) hepatocarcinogenicity in Shastastrain rainbow trout (Oncorhynchus mykiss) and the potentialof DEN to elicit ras proto-oncogene activation in this species.Carcinogen was administered in the diet at five concentrationsfor 12 months. Necropsies were per formed at 9, 12, and 18 months,the latter on fish maintained on control diet for 6 months aftercessation of DEN exposure. The incidence of hepatic neoplasmsat the lower dietary concentrations (70 ppm) did not consistentlyexceed that for control groups, which were higher in this particularstudy (2%) than expected (historically 0.1%). For the higherDEN concentrations, a linear relationship between the hepatictumor incidence (expressed as log odds, log [p/(1-p)1, wherep = proportion of fish bearing tumors), and the logarithm oftotal cumulative dose was observed, with response being independentof the length of time (9 or 12 months) during which the dosewas accumulated. The dose-response curve for fish maintainedan additional 6 months postexposure was shifted toward higherincidence but was parallel to the curve for fish killed at cessationof exposure. The model predicts that doubling the dose willproduce some what more than a doubling of the odds (pl(100 -p) for tumor incidence and that the odds for lesions 6 monthspostexposure will be approximately double those at cessationof exposure. Comparison of these results with previous studiesusing rats suggests an overall similarity in dose-response curves,with trout being somewhat less sensitive than rats to DEN hepatocarcinogenesis. To examine the molecular basis for DEN carcinogenesis in this species, seven liver tumors induced separatelyby short-term DEN treatment were probed by 3'-mismatch primerpolymerase chain reaction analysis for evidence of Ki-ras proto-oncogeneactivating point mutations. A very high proportion (6/7) oftumors was found to carry codon 12 GGA - AGA mutations, whereasno codon 61 mutants were detected in this sample. These initialresults differ from those reported using hepatic tumors fromDEN-treated mice, which exhibit frequent Ha-ras codon 61 mutations[Richardson et al., Carcinogenesis 13, 12771279 (1992)]and rats, which appear not to carry DEN-activated ras alleles[Bauer-Hoffman et al., Carcinogenesis 11, 18751877 (1990)].Thus the available oncogene data for the common carcinogen DENdo not suggest a simple, consistent oncogenic pathway or mutationalspectrum useful in the molecular epidemiology of human cancers. 相似文献
3.
H. C. SCHILTER A. T. M. PEREIRA P. D. ESCHENAZI A. FERNANDES D. SHIM A. L. S. SOUSA M. M. TEIXEIRA D. NEGRÃO‐CORRÊA 《Parasite immunology》2010,32(3):184-192
Nematode infections are generally followed by high rates of reinfection, leading to elevated prevalence in endemic areas. Therefore, the effective control of nematode infections depends on understanding the induction and regulation of protective mechanisms. However, most experimental models for protective immune response against nematodes use high parasite exposure, not always reflecting what occurs naturally in human populations. In this study, we tested whether infecting mice with different Strongyloides venezuelensis larvae loads would affect protective responses against reinfection. Interestingly, we found that a previous infection with 10–500 larvae conferred high rate of protection against reinfection with S. venezuelensis in mice, by destroying large numbers of migrating larvae. However, low‐dose priming did not abolish adult worm maturation, as detected in high‐dose primed group. Results also indicated that a previous low‐dose infection delayed the development of cellular infiltrate, while a high inoculum rapidly induced these inflammatory features. Cytokine production by splenocyte cultures of challenge infected mice demonstrated that low‐dose priming had increased production of IL‐4 and IFN‐γ, while high‐dose induced IL‐4 production but not IFN‐γ. Our data support the hypothesis that low‐dose nematode infection does not induce a polarized type‐2 immune response, allowing adult worm survival. 相似文献
4.
Anuradha PRAKKI Renato CILLI Ian Matos VIEIRA Kristina DUDUMAS José Carlos PEREIRA 《Journal of applied oral science : revista FOB》2012,20(4):472-477
Objectives
To evaluate the effect of additives on the water sorption characteristics of Bis-GMA based copolymers and composites containing TEGDMA, CH3Bis-GMA or CF3Bis-GMA.Material and methods
Fifteen experimental copolymers and corresponding composites were prepared combining Bis-GMA and TEGDMA, CH3Bis-GMA or CF3Bis-GMA, with aldehyde or diketone (24 and 32 mol%) totaling 30 groups. For composites, barium aluminosilicate glass and pyrogenic silica was added to comonomer mixtures. Photopolymerization was effected by 0.2 wt% each of camphorquinone and N,N-dimethyl-p-toluidine. Specimen densities in dry and water saturated conditions were obtained by Archimedes'' method. Water sorption and desorption were evaluated in a desorption-sorption-desorption cycle. Water uptake (%WU), water desorption (%WD), equilibrium solubility (ES; µg/mm3), swelling (f) and volume increase (%V) were calculated using appropriate equations.Results
All resins with additives had increased %WU and ES. TEGDMA-containing systems presented higher %WU, %WD, ES, f and %V values, followed by resins based on CH3Bis-GMA and CF3Bis-GMA.Conclusions
Aldehyde and diketone led to increases in the water sorption characteristics of experimental resins. 相似文献5.
Camila Santos PEREIRA Marcos Vinícius Macedo de OLIVEIRA Lucas Oliveira BARROS Gabriela Alencar BANDEIRA Sérgio Henrique Sousa SANTOS John R. BASILE André Luiz Sena GUIMAR?ES Alfredo Maurício Batista DE PAULA 《Journal of applied oral science : revista FOB》2013,21(5):416-421
Objective
This study aimed to investigate the expression of the MSH2 DNA repair protein in head and neck squamous cell carcinoma (HNSCC) in order to analyze its association with clinicopathologic factors and overall survival of patients.Material and Methods
Clinical data and primary lesions of HNSSC were collected from 55 patients who underwent surgical resection with postoperative radiotherapy in Montes Claros, state of Minas Gerais, Brazil, between 2000 and 2008. Immunohistochemical reactions were performed to analyze MSH2 protein expression.Results
Bivariate analysis showed no significant correlation or association between MSH2 expression and clinicopathologic parameters by Mann-Whitney and Kruskal-Wallis tests. Patients with locoregional metastatic disease (OR=4.949, p<0.001) and lower MSH2 immunohistochemical expressions (OR=2.943, p=0.032) presented poorer survival for HNSCC by Cox regression models.Conclusions
Our data demonstrated that lower MSH2 expression might contribute to a higher clinic aggressiveness of HNSCC by promoting an unfavorable outcome. 相似文献6.
7.
Manoel BRITO-JúNIOR André Luis FARIA-E-SILVA Carla Cristina CAMILO Rodrigo Dantas PEREIRA Neilor Mateus Antunes BRAGA Manoel Dami?o SOUSA-NETO 《Journal of applied oral science : revista FOB》2014,22(2):98-102
Objective
This study evaluated apical transportation associated with ProTaper® Universal Fl, F2 and F3 rotary files in curved canais prepared by undergraduate students.Material and Methods
Twenty mesial roots of mandibular molars with curvatures ranging between 25° and 35° were selected. Mesiobuccal canals were instrumented by twenty students with the ProTaper® system (Dentsply-Maillefer, Ballaigues, Switzerland) according to the manufacturer''s instructions. Pre-fiaring was performed with Sl and SX files. A #15 K-file was inserted into the root canal up to the working length (WL), and an initial digital radiograph was taken in a buccolingual direction (baseline). Afterwards, the S1, S2, F1, F2, and F3 files were employed up to the WL. Other radiographies were taken in the same orientation of the baseline after the use of the Fl, F2, and F3 files, with each file inserted into the root canal. The radiographic images were overlapped, and the Image J software was used to measure the distance between the rotary files'' ends and the #15 K-file''s end, characterizing the apical transportation. Data were analyzed by Repeated Measure ANOVA and by the SNK post hoc test (P<0.05).Results
It was verified that file size affected apical transportation significantly (P<0.001). The F3 file showed higher apical transportation than Fl and F2, while between these last files there was no difference.Conclusion
The undergraduate students produced lower apical transportation in curved canals when they did not use the F3 rotary file. 相似文献8.
M. K. GEORGIEFF S. R. SASANOW U. M. CHOCKALINGAM G. R. PEREIRA 《Acta paediatrica (Oslo, Norway : 1992)》1988,77(2):214-219
ABSTRACT. We studied the accuracy of the ponderal index and the mid-arm circumference/head circumference ratio for detecting newborn infants who were likely to be symptomatic because of aberrant intrauterine growth. Sixty infants were evaluated because of suspected intrauterine growth retardation; both the mean ponderal index and mid-arm circumference/head circumference ratio were significantly lower in the group of 30 symptomatic infants than in the group of 30 asymptomatic infants ( p <0.05). However, the mid-arm circumference/head circumference ratio identified a significantly higher percentage of the symptomatic infants than the ponderal index (80% vs. 47%; p =0.007). An additional 60 infants were evaluated because of suspected abnormal intrauterine growth acceleration. The mean mid-arm circumference/head circumference ratio, but not the ponderal index, was significantly higher in the group of 30 symptomatic infants than in the group of 30 asymptomatic infants ( p <0.005). Again, the mid-arm circumference/head circumference ratio identified a significantly higher percentage of the symptomatic infants than the ponderal index (79% vs. 33%; p <0.001). The mid-arm circumference/head circumference ratio is more accurate than the ponderal index for the evaluation of potentially symptomatic newborn infants who suffered abnormal fetal growth. The ponderal index is not useful for the detection of symptomatic large-for-dates infants. 相似文献
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