Characterization of Sm14 related components in different helminths by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blotting analysis

Sm14 was the first fatty acid-binding protein homologue identified in helminths. Thereafter, members of the same family were identified in several helminth species, with high aminoacid sequence homology between them. In addition, immune crossprotection was also reported against Fasciola hepatica infection, in animals previously immunized with the Schistosoma mansoni vaccine candidate, r-Sm14. In the present study, data on preliminary sodium dodecyl sulphate-polyacrylamide gel electrophoresis and Western blotting analysis of nine different helminth extracts focusing the identification of Sm14 related proteins, is reported. Out of these, three extracts - Ascaris suum (males and females), Echinostoma paraensei, and Taenia saginata - presented components that comigrated with Sm14 in SDS-PAGE, and that were recognized by anti-rSm14 policlonal serum, in Western blotting tests.

Hospitalization due to norovirus and genotypes of rotavirus in pediatric patients, state of Espírito Santo

Viruses are the leading cause for hospitalization due to gastroenteritis worldwide. Group A rotaviruses (RV) are the most prevalent and are assorted in glycoproteins (G) and protease sensitive (P) dual genotypes based on polymorphic genes that encode the external VP7 and VP4 capsid proteins, respectively. Noroviruses (NoV) have increasingly answered by sporadic gastroenteritis. This study aimed to determine the prevalence of NoV and RV in 68 hospitalized children, between July 2004 and November 2006, at a pediatric hospital in Vitória city, state of Espírito Santo, Southeastern Brazil. Nucleic acid was extracted from fecal suspension following the guanidine-silica procedure. Reverse transcriptase-polymerase chain reaction (RT-PCR) and polyacrylamide gel electrophoresis were employed for NoV and RV detection, respectively. RV genotyping was accomplished using RT-PCR followed by heminested multiplex PCR with specific primers for the most prevalent types of G and P. Fecal samples were positive for NoV and RV in 39.7% (27/68) and 20.5% (14/68), respectively and together were responsible for 60% (41/68) of the cases. RV genotypes were: 50% G9P[8], 28.7% G2P[4], 7.1% G1P[8], G2P[8] and G?P[8]. Vomit was a prominent manifestation observed in 92% and 85% of the NoV and RV cases, respectively. The median hospitalization was 5 and 5.5 days for the patients infected with NoV and RV, respectively. The data showed that NoV prevailed over RV and it also corroborated the emergence of RV G9 genotype followed by G2P[4], reinforcing the need for RV genotype surveillance.

Pulsed-field gel electrophoresis, virulence determinants and antimicrobial susceptibility profiles of type Ia group B streptococci isolated from humans in Brazil

Group B streptococci (GBS) infections occur worldwide. Although serotyping has been used for epidemiologic purposes, this does not accurately characterize enough members of a genetically heterogeneous bacterial population. The aims of this work were to evaluate the genetic diversity of 45 type Ia GBS strains isolated in Brazil by pulsed-field gel electrophoresis as well as to evaluate antimicrobial susceptibility profiles and identify virulence genes. Twenty-four strains were assigned to cluster A. All strains under study contained the hylB and scpB genes. The bca gene was detected in only 10 strains and none of the streptococci carried the bac gene. Thirty-nine strains were resistant to tetracycline.

Time-based distribution of Staphylococcus saprophyticus pulsed field gel-electrophoresis clusters in community-acquired urinary tract infections

The epidemiology of urinary tract infections (UTI) by Staphylococcus saprophyticus has not been fully characterised and strain typing methods have not been validated for this agent. To evaluate whether epidemiological relationships exist between clusters of pulsed field gel-electrophoresis (PFGE) genotypes of S. saprophyticus from community-acquired UTI, a cross-sectional surveillance study was conducted in the city of Rio de Janeiro, Brazil. In total, 32 (16%) female patients attending two walk-in clinics were culture-positive for S. saprophyticus. Five PFGE clusters were defined and evaluated against epidemiological data. The PFGE clusters were grouped in time, suggesting the existence of community point sources of S. saprophyticus. From these point sources, S. saprophyticus strains may spread among individuals.

Variabilidade genética em cultivares de soja determinada com marcadores microssatélites em gel de agarose

O objetivo deste trabalho foi avaliar a variabilidade genética de cultivares de soja com marcadores microssatélites selecionados e caracterizados quanto à informatividade para uso em gel de agarose. O DNA de 23 cultivares de soja foi amplificado com 283 marcadores microssatélites em gel de agarose a 3%. Posteriormente, 53 marcadores que apresentaram polimorfismo facilmente detectável nos géis de agarose foram utilizados na caracterização de 53 cultivares. Nessas cultivares foram detectados 124 alelos, com média de 2,34 alelos por loco, e os valores de conteúdo de informação polimórfica variaram entre 0,16 e 0,66, com média de 0,47. As frequências alélicas variaram de 0,02 a 0,91, com média de 0,43. A distância genética calculada variou de 0,02 a 0,73, com média de 0,47. A menor distância observada foi entre as cultivares CD201 e CD208, e a maior distância entre CD210 e BRSMT Uirapuru. Os marcadores utilizados possibilitaram a identificação das 53 cultivares avaliadas. Os locos microssatélites de soja, avaliados em gel de agarose, apresentam elevada informatividade. É possível detectar variabilidade significativa no germoplasma brasileiro de soja avaliado, mesmo entre cultivares elite, quando se usa marcadores moleculares microssatélites selecionados por sua informatividade.

Alterações fisiológicas e bioquímicas em sementes de café secas em sílica gel e soluções salinas saturadas

O objetivo deste trabalho foi avaliar alterações fisiológicas e bioquímicas em sementes de café submetidas à secagem rápida, em sílica gel, e à secagem lenta, em soluções salinas saturadas. As sementes foram secas até que atingissem os seguintes teores de água: 40, 30, 20, 15, 10 e 5% (base úmida). Após a secagem, uma parte das sementes foi imediatamente avaliada quanto ao desempenho fisiológico e ao perfil de enzimas do processo oxidativo, e outra parte foi avaliada após armazenagem em condição hermética, em câmara fria e seca, por quatro meses. A velocidade de secagem e o teor final de água tiveram efeito significativo sobre a qualidade fisiológica das sementes. Após a secagem rápida em sílica gel, as sementes toleraram teores finais de água mais baixos. No entanto, após a secagem lenta, as sementes com teores finais de água mais elevados apresentaram maior qualidade. O período de armazenamento não afetou a germinação, mas prejudicou o vigor das sementes. A secagem rápida apresenta maior potencial de dano ao endosperma do que aos embriões. O perfil enzimático das sementes de café é afetado pelo teor final de água e pela velocidade de secagem.

Organo-gel: um novo sistema para a imobilização de lipases e sua aplicação em síntese orgânica

Lipases have been immobilized in microemulsion-based organogels (MBG's) and successfully utilized for the enantioselective esterification, diesterification and transesterification reactions, in organic solvents at 25ºC. This methodology is described as a new alternative for the use of enzymes in organic solvents. High enzymic stability has been observed. We have also used this methodology for the successful resolution of chiral secondary alcohols. This is a convenient way of using this catalyst in organic solvents which employs small amounts of the enzyme (250mg/mL).

Optical characterization of sol-gel glasses derived from Eu3+ complex-forming precursors

Fabrication of new optical devices based upon the incorporation of rare earth ions via sol-gel methods depends on elimination of dopant ion clusters and residual hydroxyl groups from the final material. The optical absorption and/or luminescence properties of luminescent rare earth ions are influenced by the local bonding environment and the distribution of the rare-earth dopants in the matrix. Typically, dopants are incorporated into gel via dissolution of soluble species into the initial precursor sol. In this work, Eu3+ is used as optical probe, to assess changes in the local environment. Results of emission, excitation, fluorescence line narrowing and lifetimes studies of Eu3+-doped gels derived from Si(OCH3)4 and fluorinated/chelate Eu3+ precursors are presented. The precursors used in the sol-gel synthesis were: tris (6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate) Eu(III), Eu (III) trifluoromethanesulfonate, Eu(III) acetylacetonate hydrate, Eu (III) trifluoroacetate trihidrate, tris (2,2,6,6-tetramethyl-3,5- heptanedionate) Eu(III) and Eu(NO3)3.6H2O. The results were interpreted in terms of the evolution of the Eu3+ fluorescence in systems varying from solution to the gels densified to 800ºC. The lifetimes studies indicate that the fluorinated precursors are effective at reducing the water content in densified gels.

Organo-gel de heptano: diagrama de fases e aplicações sintéticas

The phase diagram formation of microemulsion-based gels composed of an anionic surfactant aerosol-OT sodium bis (2-ethylhexyl)-sulphosuccinate), water, gelatin and an organic solvent is presented for heptane. The stability of this organo- gel, when an enzyme is immobilized is discussed in terms of its reutilization in various esters synthesis.

Síntese e reatividade de sílica lamelar

An overview of the experimental procedures to prepare lamellar samples of silica, as well as the reactivity and possible applications of this kind of material is presented. Special attention is focused on the obtained materials by using neutral dialkylamine route through sol-gel process.

Dióxido de titânio sol-gel: propriedades e comportamento eletrocrômico

Titanium dioxide was prepared by hydrolysis and polycondensation of titanium tetraisopropoxide. TiO2 films were obtained by spin coating of the precursor solution on ITO substractes (glass covered with indium doped tin oxide). Films were prepared using different temperatures and hydrochloric acid contents. The effect of the drying temperature of the films (100 or 400ºC) was also investigated. TiO2 films were characterized by cyclic voltammetry, chronoamperometry, ultraviolete-visible spectroscopy, scanning electron microscopy and X-ray diffractrometry.

Caracterização de quitosana por Cromatografia de Permeação em Gel - Influência do método de preparação e do solvente

In this work, samples of chitosan obtained in different conditions were characterized by molecular weight distribution, using Gel Permeation Chromatography (GPC), in two different solvents. It was observed that the increase in the number of deacetylation steps promotes a increase in the degree of deacetylation followed by a decrease in the average of molecular weight and polydispersion. The GPC curves obtained for chitosan samples in the two solvents used (CH3COOH 0.30 mol/dm³ - CH3CONa 0.20 mol/dm³ and CH3COOH 0.10 mol/dm³ - NaCl 0.20 mol/dm³) showed small difference in elution volume, but significant changes in the average molecular weight (Mn and Mw) and polydispersion that, in agree with the values of Huggins constant, present evidences of chitosan aggregates formation in the second solvent.

Extração em fase sólida (SPE) e micro extração em fase sólida (SPME) de piretróides em água

The pyrethroids bifenthrin, permethrin, cypermethrin and deltamethrin were extracted by solid phase extraction (SPE) and solid phase microextraction (SPME). The analysis were performed on a gas chromatograph with electron capture detection (GC-ECD). Octadecil Silano-C18, Florisil and Silica stationary phases were studied for SPE. Better results were obtained for Florisil which gave recoveries from 80% to 108%. Pyrethroids extraction by SPME showed a linear response and a detection limit of 10 pg ml-1. Although the data showed that the two extraction methods were able to isolate the pesticide residues from water samples, the best results were obtained by using SPME which is more sensitive, faster, cheeper, being a more useful technique for the analysis of pyrethroids in drinking water.

Caracterização textural e estrutural de V2O5/TiO2 obtidos via sol-gel: comparação entre secagem convencional e supercrítica

This work describes a modified sol-gel method for the preparation of V2O5/TiO2 catalysts. The samples have been characterized by N2 adsorption at 77K, x-ray diffractometry (XRD) and Fourier Transform Infrared (FT-IR). The surface area increases with the vanadia loading from 24 m² g-1, for pure TiO2, to 87 m² g-1 for 9wt.% of V2O5. The rutile form is predominant for pure TiO2 but became enriched with anatase phase when vanadia loading is increased. No crystalline V2O5 phase was observed in the catalysts diffractograms. Two species of surface vanadium observed by FT-IR spectroscopy a monomeric vanadyl and polymeric vanadates, the vanadyl/vanadate ratio remains practically constant.

A utilização de materiais obtidos pelo processo de sol-gel na construção de biossensores

The use of sol-gel materials to develop new biosensors has received great attention due to its characteristics and versatility of sol-gel process. An overview is presented of the state-of-the-art of electrochemical biosensors employing sol-gel materials. Low-temperature, porous sol-gel ceramics represent a new class for the immobilization of biomolecules. The rational design of sol-gel sensing materials, based on the judicious choice of the starting alkoxide, encapsulated reagents, and preparation conditions, allows tailoring of material properties in a wide range, and offers great potential for the development of electrochemical biosensors.