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1.
Sci Rep ; 9(1): 14555, 2019 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-31601937

RESUMEN

The influence of sliding speed in the nanoscale friction forces between a silicon tip and monolayer and multilayer graphene were investigated with the use of an atomic force microscope. We found that the friction forces increase linearly with the logarithm of the sliding speed in a highly layer-dependent way. The increase in friction forces with velocity is amplified at the monolayer. The amplification of the friction forces with velocity results from the introduction of additional corrugation in the interaction potential driven by the tip movement. This effect can be interpreted as a manifestation of local thermally induced surface corrugations in nanoscale influencing the hopping dynamics of the atoms at the contact. These experimental observations were explained by modeling the friction forces with the thermally activated Prandtl-Tomlinson model. The model allowed determination of the interaction potential between tip and graphene, critical forces, and attempt frequencies of slip events. The latter was observed to be dominated by the effective contact stiffness and independent of the number of layers.

2.
Biomed Res Int ; 2019: 9524378, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31930141

RESUMEN

BACKGROUND: Adequate thyroid function is essential for normal growth and development of the fetus. Sonographic recognition of alterations in fetal thyroid dimensions may be the first sign of thyroid dysfunction, permitting early diagnosis and intervention. The main goal of this study was to build curves with reference values for ultrasound measurements of the fetal thyroid from 14 to 40 weeks of gestation. METHODS: This is a prospective longitudinal study of 90 Brazilian pregnant women, complementary to a cohort multicentre study named "WHO multicentre study for the development of growth standards from fetal life to childhood: the fetal component." Pregnant women without any pre-existing conditions that might affect fetal growth received antenatal care from the first trimester until childbirth, undergoing serial ultrasound evaluations of the fetus, including the thyroid. Longitudinal, anteroposterior, and transverse diameters of both thyroid lobes were measured in the fetus. Fetal thyroid lobe volume was also estimated. By quantile regression analysis, reference curves of measurements were fitted according to the gestational age. RESULTS: A reference standard of thyroid growth was defined during pregnancy by fitting curves of its measurements. Reference values for the 10th, 50th, and 90th centiles of fetal thyroid measurements (longitudinal, anteroposterior, transverse diameters, and lobe volume) were defined, from 14 to 40 weeks of gestation. CONCLUSION: We provided a reference curve of optimal thyroid development in a low-risk population that can be used as a standard of comparison to diagnose deviations from the norm. In addition, we demonstrated an alternative and simplified method for early recognition of thyroid morphological alterations by an individualized technique to evaluate the thyroid lobes.


Asunto(s)
Feto/diagnóstico por imagen , Glándula Tiroides/diagnóstico por imagen , Adolescente , Adulto , Brasil , Estudios de Cohortes , Femenino , Desarrollo Fetal/fisiología , Edad Gestacional , Humanos , Estudios Longitudinales , Embarazo , Atención Prenatal/métodos , Estudios Prospectivos , Valores de Referencia , Enfermedades de la Tiroides/diagnóstico , Enfermedades de la Tiroides/diagnóstico por imagen , Ultrasonografía Prenatal/métodos , Adulto Joven
3.
J Orthod ; 45(2): 79-93, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29504867

RESUMEN

AIMS: The purpose of this study was to evaluate the efficacy of orthodontic bonding systems containing different antimicrobial agents, as well as the influence of antimicrobial agent incorporation in the bonding properties of these materials. METHODS: Eight databases were searched: PubMed (Medline), Web of Science, Scopus, Lilacs, Ibecs, BBO, Scielo and Google Scholar. Any study that evaluated antimicrobial activity in experimental or commercial orthodontic bonding systems was included. DATA EXTRACTION: Data were tabulated independently and in duplicated by two authors on pre-designed data collection form. DATA SYNTHESIS: The global analysis was carried out using a random-effects model, and pooled-effect estimates were obtained by comparing the standardised mean difference of each antimicrobial orthodontic adhesive with the respective control group. A p-value < .05 was considered as statistically significant. RESULTS: Thirty-two studies were included in the qualitative analysis; of these, 22 studies were included in the meta-analysis. Antimicrobial agents such as silver nanoparticles, benzalkonium chloride, chlorhexidine, triclosan, cetylpyridinium chloride, Galla chinensis extract, acid ursolic, dimethylaminododecyl methacrylate, dimethylaminohexadecyl methacrylate, 2-methacryloyloxyethyl phosphorylcholine, 1,3,5-triacryloylhexahydro-1,3,5-triazine, zinc oxide and titanium oxide have been incorporated into orthodontic bonding systems. The antimicrobial agent incorporation in orthodontic bonding systems showed higher antimicrobial activity than the control group in agar diffusion (overall standardised mean difference: 3.71; 95% CI 2.98 to 4.43) and optical density tests (0.41; 95% CI -0.05 to 0.86) (p < .05). However, for biofilm, the materials did not present antimicrobial activity (6.78; 95% CI 4.78 to 8.77). Regarding bond strength, the global analysis showed antimicrobial orthodontic bonding systems were statistically similar to the control. CONCLUSIONS: Although there is evidence of antibacterial activity from in vitro studies, clinical and long-term studies are still necessary to confirm the effectiveness of antibacterial orthodontic bonding systems in preventing caries disease.


Asunto(s)
Antiinfecciosos , Recubrimiento Dental Adhesivo , Nanopartículas del Metal , Ensayo de Materiales , Cementos de Resina , Plata
4.
Genet Mol Res ; 16(2)2017 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-28549197

RESUMEN

Fusarium wilt caused by Fusarium oxysporum f. sp lycopersici (Fol) is one of the main diseases affecting tomatoes. The BHRS 2,3 genotype of tomato is, however, resistant to this disease. A proteomic approach was used to understand the defense mechanisms of this genotype using the tomato root, the first tissue that interacts with the fungus, as a target. Protein was extracted and separated by two-dimensional electrophoresis followed by staining with Coomassie brilliant blue. The proteins were identified by MALDI-TOF/TOF mass spectrometry. A total of 22 proteins were identified, 21 of which showed differential expression with 12 proteins being upregulated and nine being downregulated. Plants responded to the pathogen with increased expression of pathogenesis-related proteins. We noted the induction of proteins involved in hypersensitivity reaction and other defense mechanisms. The expression of proteins of primary metabolism related to energy production, however, decreased, as did the expression of two proteins related to defense against abiotic stress. These results demonstrate the presence of important mechanisms for defense against Fol in the tomato genotype BHRS 2,3.


Asunto(s)
Resistencia a la Enfermedad/genética , Fusarium/patogenicidad , Raíces de Plantas/metabolismo , Proteoma/genética , Solanum lycopersicum/genética , Regulación de la Expresión Génica de las Plantas , Solanum lycopersicum/inmunología , Solanum lycopersicum/microbiología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/genética , Raíces de Plantas/microbiología , Proteoma/metabolismo , Estrés Fisiológico
5.
Braz J Biol ; 75(3 Suppl 1): 277-89, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26691100

RESUMEN

In this paper some preliminary fossil specimens are presented. They represent a collection sampled by Belo Monte's Programa de Salvamento do Patrimônio Paleontológico (PSPP), which includes unprecedented invertebrate fauna and fossil vertebrates from Pitinga, Jatapu, Manacapuru, Maecuru e Alter do Chão formations from Amazonas basin, Brazil. The Belo Monte paleontological salvage was able to recover 495 microfossil samples and 1744 macrofossil samples on 30 months of sampling activities, and it is still ongoing. The macrofossils identified are possible plant remains, ichnofossils, graptolites, brachiopods, molluscs, athropods, Agnatha, palynomorphs (miosphores, acritarchs, algae cysts, fungi spores and unidentified types) and unidentified fossils. However, deep scientific research is not part of the scope of the program, and this collection must be further studied by researchers who visit Museu Paraense Emilio Goeldi, where the fossils will be housed. More material will be collected until the end of the program. The collection sampled allows a mosaic composition with the necessary elements to assign, in later papers, taxonomic features which may lead to accurate species identification and palaeoenvironmental interpretations.


Asunto(s)
Fósiles , Invertebrados/clasificación , Plantas/clasificación , Vertebrados/clasificación , Animales , Brasil , Paleontología , Centrales Eléctricas , Ríos
6.
Braz. J. Biol. ; 75(3,supl.1): 277-289, Aug. 2015. graf
Artículo en Inglés | VETINDEX | ID: vti-341499

RESUMEN

In this paper some preliminary fossil specimens are presented. They represent a collection sampled by Belo Montes Programa de Salvamento do Patrimônio Paleontológico (PSPP), which includes unprecedented invertebrate fauna and fossil vertebrates from Pitinga, Jatapu, Manacapuru, Maecuru e Alter do Chão formations from Amazonas basin, Brazil. The Belo Monte paleontological salvage was able to recover 495 microfossil samples and 1744 macrofossil samples on 30 months of sampling activities, and it is still ongoing. The macrofossils identified are possible plant remains, ichnofossils, graptolites, brachiopods, molluscs, athropods, Agnatha, palynomorphs (miosphores, acritarchs, algae cysts, fungi spores and unidentified types) and unidentified fossils. However, deep scientific research is not part of the scope of the program, and this collection must be further studied by researchers who visit Museu Paraense Emilio Goeldi, where the fossils will be housed. More material will be collected until the end of the program. The collection sampled allows a mosaic composition with the necessary elements to assign, in later papers, taxonomic features which may lead to accurate species identification and palaeoenvironmental interpretations.(AU)


Neste artigo são apresentados de forma preliminar alguns espécimes fósseis representativos do acervo coletado no Programa de Salvamento do Patrimônio Paleontológico (PSPP) da UHE Belo Monte, que inclui fauna vertebrada e invertebrada inédita das formações Pitinga, Jatapu, Manacapuru, Maecuru e Alter do Chão, da bacia do Amazonas, Brasil. No salvamento paleontológico de Belo Monte foi possível recuperar 495 amostras para microfósseis e 1744 amostras com macrofósseis em 30 meses de amostragem, que ainda continua em andamento. Os macrofósseis identificados são possíveis restos de plantas, icnofósseis, graptolitos, braquiópodes, moluscos, artópodes, Agnatha, palinomorfos (miósporos, acritarcas, cistos de alga, esporos de fungo e tipos indeterminados) além de fósseis não identificados. No entanto, pesquisa científica aprofundada não é parte do escopo do programa, e esta coleção deve ser estudada no futuro por pesquisadores pela visita ao Museu Paraense Emilio Goeldi, onde os fósseis ficarão depositados. Mais material será coletado até o fim de 2015. A assemblagem coletada permite a composição de mosaico com elementos necessários para a definição, em artigos futuros, características taxonômicas que levarão à identificação precisa de espécies e interpretações paleoambientais.(AU)


Asunto(s)
Animales , Fósiles , Invertebrados/clasificación , Plantas/clasificación , Vertebrados/clasificación , Brasil , Paleontología , Centrales Eléctricas , Ríos
7.
Braz. j. biol ; Braz. j. biol;75(3,supl.1): 277-289, Aug. 2015. graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1468299

RESUMEN

In this paper some preliminary fossil specimens are presented. They represent a collection sampled by Belo Monte’s Programa de Salvamento do Patrimônio Paleontológico (PSPP), which includes unprecedented invertebrate fauna and fossil vertebrates from Pitinga, Jatapu, Manacapuru, Maecuru e Alter do Chão formations from Amazonas basin, Brazil. The Belo Monte paleontological salvage was able to recover 495 microfossil samples and 1744 macrofossil samples on 30 months of sampling activities, and it is still ongoing. The macrofossils identified are possible plant remains, ichnofossils, graptolites, brachiopods, molluscs, athropods, Agnatha, palynomorphs (miosphores, acritarchs, algae cysts, fungi spores and unidentified types) and unidentified fossils. However, deep scientific research is not part of the scope of the program, and this collection must be further studied by researchers who visit Museu Paraense Emilio Goeldi, where the fossils will be housed. More material will be collected until the end of the program. The collection sampled allows a mosaic composition with the necessary elements to assign, in later papers, taxonomic features which may lead to accurate species identification and palaeoenvironmental interpretations.


Neste artigo são apresentados de forma preliminar alguns espécimes fósseis representativos do acervo coletado no Programa de Salvamento do Patrimônio Paleontológico (PSPP) da UHE Belo Monte, que inclui fauna vertebrada e invertebrada inédita das formações Pitinga, Jatapu, Manacapuru, Maecuru e Alter do Chão, da bacia do Amazonas, Brasil. No salvamento paleontológico de Belo Monte foi possível recuperar 495 amostras para microfósseis e 1744 amostras com macrofósseis em 30 meses de amostragem, que ainda continua em andamento. Os macrofósseis identificados são possíveis restos de plantas, icnofósseis, graptolitos, braquiópodes, moluscos, artópodes, Agnatha, palinomorfos (miósporos, acritarcas, cistos de alga, esporos de fungo e tipos indeterminados) além de fósseis não identificados. No entanto, pesquisa científica aprofundada não é parte do escopo do programa, e esta coleção deve ser estudada no futuro por pesquisadores pela visita ao Museu Paraense Emilio Goeldi, onde os fósseis ficarão depositados. Mais material será coletado até o fim de 2015. A assemblagem coletada permite a composição de mosaico com elementos necessários para a definição, em artigos futuros, características taxonômicas que levarão à identificação precisa de espécies e interpretações paleoambientais.


Asunto(s)
Animales , Fósiles , Invertebrados/clasificación , Plantas/clasificación , Vertebrados/clasificación , Brasil , Centrales Eléctricas , Paleontología , Ríos
8.
Nanotechnology ; 23(25): 255305, 2012 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-22652838

RESUMEN

In this work, we clarify the features of the lateral damage of line defects in single layer graphene. The line defects were produced through well-controlled etching of graphene using a Ga(+) focused ion beam. The lateral damage length was obtained from both the integrated intensity of the disorder induced Raman D band and the minimum ion fluence. Also, the line defects were characterized by polarized Raman spectroscopy. It was found that graphene is resilient under the etching conditions since the intensity of the defect induced Raman D peak exhibits a dependence on the direction of the lines relative to the crystalline lattice and also on the direction of the laser polarization relative to the lines. In addition, electrical measurements of the modified graphene were performed. Different ion fluences were used in order to obtain a completely insulating defect line in graphene, which was determined experimentally by means of charge injection and electric force microscopy measurements. These studies demonstrate that a Ga+ ion column combined with Raman spectroscopy is a powerful technique to produce and understand well-defined periodic arrays of defects in graphene, opening possibilities for better control of nanocarbon devices.

9.
Scand J Immunol ; 73(5): 486-95, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21231952

RESUMEN

The rational of this study we intended to investigate whether the peripheral blood immunological/virological biomarkers were associated with distinct patterns of sleeping quality in patients with chronic hepatitis C-(HCV). Distinct well-established indexes/scores were used to categorize the sleeping quality of HCV patients, including the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale and Fatigue Severity Scores. Our findings demonstrated that HCV patients classified as 'good sleeper' displayed an enhanced frequency of circulating CD8(+) T cells, lower frequency of activated (CD69(+)) neutrophils and eosinophils but enhanced frequency of activated lymphocytes besides lower seric levels of IL-4/IL-8/IL-10 but higher levels of IL-12, besides lower HCV virus load and lower anti-HCV IgG levels. In contrast, HCV patients classified as 'poor sleeper' displayed enhanced levels of activated neutrophils and eosinophils but lower frequency of activated lymphocytes, higher seric levels of IL-6/TNF-α/IL-10 but lower levels of IL-12 besides higher HCV virus load and increased anti-HCV IgG levels. Positive correlation was further confirmed by the relationship between the leucocyte activation status, the cytokine levels, the HCV viral load and the anti-HCV IgG reactivity with the PSQI indexes. Analysis of cytokine signature curves demonstrated that lower frequency of IL-10 was observed in HCV patients classified as 'good sleepers', whereas enhanced frequency of IL-6 was found HCV patients classified as 'poor sleepers'. In conclusion, our data suggest that immunological biomarkers (leucocytes activation status and seric cytokines levels) are likely to be associated with sleeping quality patterns in HCV patients, suggesting their putative use for clinical monitoring purposes.


Asunto(s)
Hepacivirus/inmunología , Hepatitis C Crónica/sangre , Trastornos del Sueño-Vigilia/sangre , Adulto , Anciano , Biomarcadores/sangre , Citocinas/genética , Citocinas/inmunología , Femenino , Citometría de Flujo , Hepatitis C Crónica/inmunología , Hepatitis C Crónica/virología , Humanos , Inmunofenotipificación , Masculino , Persona de Mediana Edad , ARN Viral/química , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Trastornos del Sueño-Vigilia/inmunología , Trastornos del Sueño-Vigilia/virología , Subgrupos de Linfocitos T/inmunología , Linfocitos T/inmunología , Adulto Joven
10.
Braz. j. phys. ther. (Impr.) ; 13(2): 173-179, Mar.-Apr. 2009. tab
Artículo en Inglés, Portugués | LILACS | ID: lil-516038

RESUMEN

Objetivo: Analisar o desempenho motor grosso e sua associação com fatores neonatais, familiares e de exposição à creche em crianças com até três anos de idade, frequentadoras de creches públicas. Métodos: Estudo transversal no qual foram avaliadas 145 crianças (58 com idade entre 6-11 meses, 54 entre 12-23 meses e 33 entre 24-38 meses) frequentadoras de seis creches públicas de Piracicaba (SP). O teste Peabody Developmental Motor Scale-2 foi utilizado para avaliação do desempenho motor grosso global e subtestes motores que compõem a escala (Reflexos, Habilidades Estacionárias, Habilidades de Locomoção e Manipulação de Objetos). Foram coletados dados neonatais, familiares e de exposição à creche e pesquisada a associação desses ao desempenho motor suspeito de atraso. Resultados: A prevalência de suspeita de atraso no desempenho motor grosso foi de 17%, com desvantagens em crianças menores de 24 meses e em Habilidades de Locomoção; encontrada associação de risco de desempenho motor grosso suspeito de atraso e renda familiar, e suspeita de atraso em Habilidades de Locomoção e escolaridade paterna. Crianças cujas famílias tinham renda mensal até R$700,00 estavam 2,81 vezes mais expostas a apresentar desempenho motor grosso suspeito de atraso. Crianças cujos pais tinham até oito anos de escolaridade apresentaram risco 4,63 vezes maior de atraso em Habilidades de Locomoção. Não foi encontrada associação de risco com as demais variáveis. Conclusão: Os resultados apontam maior atenção ao desenvolvimento motor durante os primeiros 24 meses de crianças que frequentam creches, especialmente as inseridas em famílias com menor renda mensal e cujos pais têm menos escolaridade.


Objective: To analyze gross motor performance and its association with neonatal and familial factors and day care exposure among children up to three years of age attending public day care centers. Methods: This was a cross-sectional study that evaluated 145 children (58 aged 6-11 months, 54 aged 12-23 months and 33 aged 24-38 months) attending six public day care centers in Piracicaba, State of São Paulo. The Peabody Developmental Motor Scale-2 test was used to assess overall gross motor performance and the motor subtests that make up the scale (reflexes, stationary skills, locomotion skills and object manipulation). Neonatal, familial and daycare center exposure data were also collected and their association with suspected delays in gross motor performance was investigated. Results: The prevalence of suspected delays in gross motor performance was 17%, with disadvantages among children under 24 months of age and with regard to locomotion skills. There were associations of risk between suspected delays in gross motor performance and family income, and between suspected delays in locomotion skills and parental educational level. Children whose families had a monthly income of up to 700 reais were 2.81 times more likely to present delays in gross motor performance. Children whose parents had up to eight years of education were 4.63 times more likely to present delays in locomotion skills. There was no association of risk with the other variables. Conclusion: The results indicate the need for greater attention to motor development during the first 24 months of children who attend day care centers, especially those with low- income and less-educated parents.

11.
J Environ Manage ; 90(8): 2448-59, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19285781

RESUMEN

The complexity of the environment demands a well-constructed composite environmental index (CEI) to provide a useful tool to draw attention to environmental conditions and trends for policy purposes. Among the common difficulties in constructing a proper CEI are uncertainties due to the selection of the most representative underlying variables or indicators. A degree of uncertainty accompanies experts' judgments, and to deal with vague, subjective or inconsistent information, logic other than classic is required. This study analyzes a procedure that uses different experts' opinions in constructing a CEI, with the use of paraconsistent annotated logic. For this, a sensitivity analysis of the Environmental Sustainability Index (ESI 2005) was used as an example to assess the reliability of experts' opinions. The uncertainty due to the disagreement in experts' opinions clearly indicates that the forms we presently use to measure and monitor the actual environment are insufficient, that is, there is a lack of a "science of sustainability".


Asunto(s)
Monitoreo del Ambiente/métodos , Monitoreo del Ambiente/normas , Testimonio de Experto
12.
Braz. j. phys. ther. (Impr.) ; 11(1): 1-5, jan.-fev. 2007. tab
Artículo en Portugués | LILACS | ID: lil-446077

RESUMEN

OBJETIVO: Avaliar as freqüências cardíaca e respiratória, a pressão arterial média, a temperatura e a saturação periférica de oxigênio dos recém-nascidos pré-termo (RNPT) de baixo peso, antes e após a aplicação do MMC. MÉTODOS: Foram avaliados 22 RNPT de baixo peso, saudáveis, de ambos os sexos, não portadores de deficiências neurológicas, cardíacas e/ou respiratórias. A avaliação foi realizada após trinta minutos de permanência do RNPT em berço comum e após trinta minutos de aplicação do MMC, por 3 dias consecutivos. Para a avaliação, foram utilizados monitor cardíaco com dispositivo para medida da pressão arterial média de forma não invasiva e sensor para a oximetria de pulso, termômetro e cronômetro. RESULTADOS: Os resultados não mostraram alterações significativas quanto à pressão arterial média (p> 0,05) e freqüência cardíaca (p> 0,05) após a aplicação do MMC, mas, por outro lado, houve aumento significativo da temperatura axilar (p< 0,05) e da saturação periférica de oxigênio (p< 0,05) e diminuição significativa da freqüência respiratória (p< 0,05). CONCLUSÃO: O MMC promove a melhora da temperatura corporal, o aumento da saturação periférica de oxigênio, melhorando a oxigenação tecidual, e a redução na freqüência respiratória, trazendo maior conforto respiratório aos RNPT, sugerindo que o MMC contribui para alterações benéficas nos sinais vitais dos RNPT.


OBJECTIVE: The aim of this study was to evaluate the heart and respiration rates, mean arterial pressure, temperature and peripheral oxygen saturation of low-weight preterm newborns, before and after the application of kangaroo mother care. METHOD: Twenty-two healthy low-weight preterm newborns of both sexes were studied. None of them had neurological, cardiac and/or respiratory deficiencies. Assessments were made after the newborn had been left in an ordinary cot for 30 minutes and after 30 minutes of kangaroo mother care, on three consecutive days. For these evaluations, a heart monitor with a device for non-invasively measuring mean arterial pressure, a sensor for pulse oximetry, a thermometer and a chronometer were utilized. RESULTS: There were no significant changes in mean arterial pressure (p> 0.05) or heart rate (p> 0.05) after applying kangaroo mother care. However, there were significant increases in axillary temperature (p< 0.05) and peripheral oxygen saturation (p< 0.05), and a significant decrease in respiration rate (p< 0.05). CONCLUSION: Kangaroo mother care promotes improvement in body temperature, increased peripheral oxygen saturation (thus improving tissue oxygenation), and decreased respiration rate (thus providing greater respiratory comfort for the newborns). This suggests that kangaroo mother care contributes towards beneficial alterations in the low-weight newborns' vital signs.


Asunto(s)
Recién Nacido , Frecuencia Cardíaca , Recién Nacido de Bajo Peso , Neonatología
13.
Scand J Immunol ; 61(6): 511-9, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15963045

RESUMEN

Localized adherence (LA) of enteropathogenic Escherichia coli (EPEC) to epithelial cells results in attaching and effacing of the surface of these cells. LA depends on the gene bfpA, which codes for the BfpA protein. We found that EPEC-E. coli adherence factor (EAF)((+)), expressing BfpA, significantly reduced HeLa cell viability in comparison with EPEC-EAF((-)), as evaluated by the mitochondrial-dependent succinate dehydrogenase conversion of 3'-[4,5,-dimethylthiazol-2yl]2,5-diphenyltetrazolium bromide (MTT) to its formazan. Apoptosis accounts for a substantial loss of the cell viability, because the cells incubated with EPEC-EAF((+)) or with cloned BfpA (data not shown), but not with EPEC-EAF((-)), were positive for annexin-V binding, demonstrated chromatin condensation and nuclei fragmentation and exhibited a high level of caspase-3 activity. Because the blockade of bacterial cell-surface-associated BfpA by anti-BfpA immunoglobulin (Ig)Y antibody suppressed apoptotic death induced by EPEC-EAF((+)), BfpA may be the trigger for apoptosis. Both EPEC-EAF((+)) and EPEC-EAF((-)), as well as recombinant BfpA (data not shown), activated nuclear factor (NF)-kappaB in a similar manner as analysed by the electrophoretic mobility shift assay (EMSA). EMSA supershift analysis demonstrated the presence of p65/RelA in a DNA-binding complex. In contrast to DNA binding, NF-kappaB-dependent reporter gene transactivation was stimulated more strongly by EPEC B171/EAF((+)), suggesting a role for this virulence factor in the regulation of transcriptional activity of NF-kappaB. Because suppression of NF-kappaB activation by BAY11-7085, a NF-kappaB inhibitor, neither induced apoptosis by itself nor blocked apoptosis induction by EPEC-EAF((+)), it may be suggested that apoptosis is not regulated by the NF-kappaB pathway in HeLa cells.


Asunto(s)
Apoptosis , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Proteínas Fimbrias/metabolismo , Fimbrias Bacterianas/metabolismo , FN-kappa B/metabolismo , Escherichia coli/patogenicidad , Células HeLa , Humanos , Factores de Virulencia/metabolismo
14.
Scand J Immunol ; 57(6): 573-82, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12791096

RESUMEN

Enteropathogenic Escherichia coli (EPEC) is a major aetiological agent of childhood diarrhoea in developing countries. The structural repeating protein A subunit, BfpA, found in the bundle-forming pilus, is one of the virulent factors for EPEC pathogenesis. Recombinant BfpA in laying hens elicited sustained and vigorous antibody production. Immunoglobulin Y (IgY) anti-BfpA antibodies were recovered from egg yolk, purified and characterized. Immunoadsorption with whole extracts of the isogenic E. coli EPEC adherence factor (EAF) strain that lacks BfpA rendered the resulting IgY preparations capable of: (a) recognizing purified or recombinant BfpA proteins in a dose-dependent fashion; (b) blocking the colonization of HeLa cells by EPEC EAF+, in vitro; (c) specifically identifying E. coli bearing EAF+; and (d) inhibiting the growth of E. coli EAF+ but not the EAF strain. IgY anti-BfpA is potentially useful as a specific, low-cost immunobiological reagent to screen human faecal specimens for the presence of EPEC.


Asunto(s)
Anticuerpos Antibacterianos/aislamiento & purificación , Proteínas de Escherichia coli/inmunología , Escherichia coli/inmunología , Escherichia coli/patogenicidad , Proteínas Fimbrias/inmunología , Animales , Anticuerpos Antibacterianos/biosíntesis , Adhesión Bacteriana/inmunología , Secuencia de Bases , Pollos , ADN Bacteriano/genética , Diarrea/microbiología , Escherichia coli/genética , Escherichia coli/crecimiento & desarrollo , Infecciones por Escherichia coli/diagnóstico , Proteínas de Escherichia coli/genética , Femenino , Proteínas Fimbrias/genética , Células HeLa , Humanos , Inmunoglobulinas/biosíntesis , Inmunoglobulinas/aislamiento & purificación , Técnicas In Vitro , Óvulo/inmunología , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología
15.
Arq Neuropsiquiatr ; 59(3-B): 815-6, 2001 Sep.
Artículo en Portugués | MEDLINE | ID: mdl-11593291

RESUMEN

Homocystinuria presenting as cerebral venous thrombosis is not usual. We report on a 13-year-old boy who was admitted to the hospital due to severe headache, nausea, vomiting and fever (38 degrees C). The patient was Marfan like and presented left hemiparesis and meningeal irritation sings. He was mentally retarded, had severe myopia, and had right lens dislocation one month before. Cranial CT scan was suggestive of cerebral venous infarct. MRI and magnetic resonance angiography showed venous infarcts more prominent in the right thalamic projection with hemorrhagic transformation and multiple foci of cortical (occipital and parietal bilaterally) deep parietal and left capsular bleeding, secondary of thrombosis of the transverse and sigmoid venous sinuses. High levels of homocysteine were detected in the blood and urine. Homocystinuria is an autosomal recessive inborn error of methionine metabolism caused by cystathionine-beta-synthase defect in most cases. We discuss the clinical and radiological findings in this patient, analyzing the pathophysiology of the thrombotic events related to homocystinuria.


Asunto(s)
Homocistinuria/complicaciones , Embolia y Trombosis Intracraneal/etiología , Trombosis Intracraneal/etiología , Adolescente , Venas Cerebrales , Homocisteína/sangre , Homocistinuria/diagnóstico , Humanos , Embolia y Trombosis Intracraneal/diagnóstico , Trombosis Intracraneal/diagnóstico , Angiografía por Resonancia Magnética , Imagen por Resonancia Magnética , Masculino
16.
Cad Saude Publica ; 17(3): 705-12, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11395807

RESUMEN

The article analyzes the World Health Organization Report for 2000, with emphasis placed on the methodology used to analyze the indicators utilized to compare and classify the performance of the health systems of the 191 member countries. The Report's contribution was the compromise of monitoring the performance of the health systems of member countries, but because of the inconsistent way it was elaborated, and the utilization of questionable scientific evaluation methodologies, the Report fails to give a clear picture. A criterion-based methodology revision is imposed. The main problems in evidence are the choice of individual indicators of disparity in health that discount the population profile, the inadequate control of the impact of social disparities over the performance of the systems, the evaluation of the responsibility of systems that are only partially articulated to the right of the citizens, the lack of data for a great number of countries, consequently having inconsistent estimations, and the lack of transparency in the methodological procedures in the calculation of some indicators. The article suggests a wide methodological revision of the Report.


Asunto(s)
Informes Anuales como Asunto , Servicios de Salud , Calidad de la Atención de Salud , Organización Mundial de la Salud , Femenino , Indicadores de Salud , Humanos , Masculino
17.
Vet Rec ; 143(21): 579-84, 1998 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-9854769

RESUMEN

Adult white leghorn hens hyperimmunised with Brazilian snake venoms of the genus Bothrops and/or Crotalus produced antibodies capable of recognising, combining with and neutralising the toxic and lethal components of the venoms. The antibodies were first detected by an enzyme-linked immunosorbent assay two weeks after starting the immunisation schedule, reached the highest titres by the third week and remained high for at least 24 weeks. These antibodies are transferred to the egg yolk from which they were isolated as enriched IgY preparations by a combination of methods using positive and negative precipitation with sodium sulphate and/or caprylic acid. The yolk-derived IgY preparations contained antibodies which blocked the phospholipase A2-dependent haemolytic activity of both venoms and the haemorrhagic activity of Bothrops venom, and neutralised the toxic lethal activities of the venoms with good efficacy. The median effective dose (ED50) of the IgY anti-Bothrops venom was 592.5 microliters/2LD50 and, 1.0 ml neutralised 0.0675 mg of venom. The ED50 of the IgY anti-Crotalus venom was 457.5 microliters/3LD50 and 1.0 ml neutralised 0.075 mg of venom.


Asunto(s)
Antivenenos/inmunología , Bothrops , Venenos de Crotálidos/inmunología , Venenos de Crotálidos/toxicidad , Crotalus , Venenos de Serpiente/inmunología , Animales , Formación de Anticuerpos , Antivenenos/biosíntesis , Pollos/inmunología , Yema de Huevo , Ensayo de Inmunoadsorción Enzimática , Inmunoglobulinas/análisis , Inmunoglobulinas/inmunología
18.
Arq Bras Cardiol ; 71(5): 681-6, 1998 Nov.
Artículo en Portugués | MEDLINE | ID: mdl-10347951

RESUMEN

PURPOSE: Evaluate functional and/or structural cardiac changes in young normotensive subjects with a family history of hypertension. METHODS: Prospective study was performed with 62 normotensive persons, ages 15 to 30 years, divided in 32 children of hypertensive patients (group 1) and 30 children of normotensive persons (group 2) comparable in blood pressure, body surface area, heart rate, age and sex. After clinical examination, all underwent Doppler-echocardiogram to evaluate cardiac structure and left ventricular (LV) systolic and diastolic function. RESULTS: Systolic LV fractional shortening was increased in group 1 when compared with group 2 (38.03 +/- 4.95% and 34.7 +/- 4.48%, respectively--p < 0.01). Mitral deceleration time (DT) ranged from 85 to 160 ms--mean values 116.47 +/- 16.99 ms--in group 1 and from 100 to 220 ms--mean values 126.73 +/- 26.66 ms--in group 2 (p < 0.05). A correlation between LV mass and left atrium (LA) diameter was noted in group 1 (r-0.514, p < 0.01). CONCLUSION: Children of hypertensive patients show increased LV function, similar to what occurs in early hypertension and in borderline hypertension, even when there is no evidence of LV hypertrophy or high blood pressure. Mitral DT (shorten in group 1) was the only diastolic parameter that differed in the groups. The correlation between LV mass and LA dimension suggests that LA size could be related to functional and hemodynamic LV changes.


Asunto(s)
Ecocardiografía Doppler , Corazón/fisiopatología , Hipertensión/diagnóstico por imagen , Adolescente , Adulto , Presión Sanguínea , Femenino , Frecuencia Cardíaca , Humanos , Hipertensión/genética , Masculino , Estudios Prospectivos , Sístole , Disfunción Ventricular Izquierda/genética
19.
Rev. SOCERJ ; 10(3): 121-7, jul. 1997. ilus, tab
Artículo en Portugués | LILACS | ID: lil-248212

RESUMEN

OBJETIVO: Analisar a dispersão do QTc nos diferentes padröes morfológicos e funcionais da hipertensão arterial sistêmica. PACIENTES E MÉTODOS: Foram estudados prospectivamente 162 pacientes portadores de hipertensão arterial sistêmica (HAS), oriundos de uma mesma instituição, e que foram submetidos a eletrocardiograma (ECG) computadorizado com registro sumultâneo das 12 derivaçöes e a ecocardiograma. Os ECGs foram analisados "off-line" por dois observadores independentes com auxílio do programa APEXPOS. Os índices de massa ventricular foram estimados pelo ecocardiograma modo M guiado pelo bidimensional, através da equação de regressão de Devereux. Os pacientes foram divididos em 64 normais (G1), 25 com remodelagem concêntrica (G2), 20 com hipertrofia ventricular (HVE) excêntrica, 43 com HVE concêntrica (G4) e 10 com disfunção sistólica do ventrículo esquerdo (G5). RESULTADO: Houve correlação significativa da dispersão do QTc com o índice de massa do ventrículo esquerdo (r=0,45 e p<0,001). Após ajuste para a idade, fração de ejeção e número de derivaçöes aferidas, a correlação manteve-se significativa (r= 0,37 e p, 0,001). Em relação à análise multivariada em "stepwise", somente a dispersão do QTc e a idade foram preditores independentes de HVE (p< 0,0001 e 0,05). As médias das dispersöes do QTc foram: ... fórmulas ..., com G4 e G5 diferindo significativamente de G1 e G2 pelo teste de Scheffé (p< 0,05). Num modelo de MANOVA, diferenças persistiram entre grupos após inclusão da idade e da fração de ejeção. CONCLUSÄO: A dispersão do QTc difere significativamente entre os diversos padröes geométricos-funcionais do ventrículo esquerdo na hipertensão arterial sistêmica, sendo preditora independente de hipertrofia ventricular esquerda.


Asunto(s)
Humanos , Masculino , Femenino , Síndrome de QT Prolongado , Disfunción Ventricular Izquierda , Hipertensión , Prevalencia , Estudios Prospectivos
20.
Cleft Palate Craniofac J ; 33(4): 297-9, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8827385

RESUMEN

In the daily routine of the Hospital for Research and Rehabilitation of Cleft Lip and Palate, a high frequency of natal/neonatal teeth was observed. Therefore, this retrospective study was conducted to determine the prevalence of this anomaly in 692 patients with complete unilateral and 327 bilateral cleft lip and palate, who were less than 3 months old, without prior surgery, and registered at the Hospital from 1989 to 1994. A higher prevalence of such teeth was found in the complete bilateral cleft group (10.6%), than in the complete unilateral cleft group (2.02%). Both, however, were higher than that reported for noncleft groups. There were also different characteristics in the appearance of these teeth in cleft patients from those previously related in the literature for normal patients. The conclusion was that these differences constitute another particularity of the cleft lip and palate patient.


Asunto(s)
Labio Leporino/epidemiología , Fisura del Paladar/epidemiología , Dientes Neonatales/patología , Brasil/epidemiología , Labio Leporino/clasificación , Fisura del Paladar/clasificación , Femenino , Humanos , Incisivo/patología , Lactante , Masculino , Maxilar/patología , Prevalencia , Sistema de Registros , Estudios Retrospectivos , Factores Sexuales , Erupción Dental , Extracción Dental
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