Cultivation and identification of colon cancer stem cell-derived spheres from the Colo205 cell line

Our group established a method to culture spheres under serum-free culture condition. However, the biological characteristics and the tumorigenicity of spheres are unknown. Here, we demonstrate that sphere cells expressed high levels of the putative colorectal cancer stem cell markers CD133 and CD44. The CD133-positive rates were 13.27 ± 5.62, 52.71 ± 16.97 and 16.47 ± 2.45% in sphere cells, regular Colo205 cells and differentiated sphere cells, respectively, while the CD44-positive rates were 62.92 ± 8.38, 79.06 ± 12.10 and 47.80 ± 2.5%, respectively, and the CD133/CD44-double-positive rates were 10.77 ± 4.96, 46.89 ± 19.17 and 12.41 ± 2.27%, respectively (P < 0.05). Cancer sphere cells formed crypt-like structures in 3-D culture. Moreover, cells from cancer spheres exhibited more tumorigenicity than regular Colo205 cells in a xenograft assay. The cancer sphere cells displayed much higher oncogenicity than regular Colo205 cells to initiate neoplasms, as assayed by H&E staining, Musashi-1 staining and electron microscopy. Our findings indicated that the sphere cells were enriched with cancer stem cells (CSCs), and exhibited more proliferation capacity, more differentiation potential and especially more tumorigenicity than regular Colo205 cells in vitro and in vivo. Further isolation and characterization of these CSCs may provide new insights for novel therapeutic targets and prognostic markers.

Evaluation of polymethylmethacrylate as ocular implant in rabbits subjected to evisceration

Spheres of different types of material are used for the replacement of lost volume after removal of the eye bulb or its content to prevent contraction of the orbital cavity. The aim of this study was to evaluate the scope of polymethylmethacrylate (PMMA) used as intraocular implant in eviscerated rabbit eye. Twelve New Zealand rabbits underwent unilateral evisceration of the left eye, with subsequent implantation of PMMA sphere 12 mm in diameter. Clinical evaluation was performed daily during the first 15 days after surgery and every 15 days until the end of the study period (180 days). For the histopathological analysis, three animals per trial underwent enucleation at 15, 45, 90 and 180 days after evisceration. There was no wound dehiscence, signs of infection or implant extrusion in any animal throughout the study period. Histological examination revealed the formation of fibrovascular tissue around the implants. The PMMA behaved as inert and non-integrable.

National Immunization Program: Computerized System as a tool for new challenges

The scope and coverage of the Brazilian Immunization Program can be compared with those in developed countries because it provides a large number of vaccines and has a considerable coverage. The increasing complexity of the program brings challenges regarding its development, high coverage levels, access equality, and safety. The Immunization Information System, with nominal data, is an innovative tool that can more accurately monitor these indicators and allows the evaluation of the impact of new vaccination strategies. The main difficulties for such a system are in its implementation process, training of professionals, mastering its use, its constant maintenance needs and ensuring the information contained remain confidential. Therefore, encouraging the development of this tool should be part of public health policies and should also be involved in the three spheres of government as well as the public and private vaccination services.

Experimental Method to Determine Some Physical Properties in Physics Classes

ABSTRACT Particle density, gravimetric and volumetric water contents and porosity are important basic concepts to characterize porous systems such as soils. This paper presents a proposal of an experimental method to measure these physical properties, applicable in experimental physics classes, in porous media samples consisting of spheres with the same diameter (monodisperse medium) and with different diameters (polydisperse medium). Soil samples are not used given the difficulty of working with this porous medium in laboratories dedicated to teaching basic experimental physics. The paper describes the method to be followed and results of two case studies, one in monodisperse medium and the other in polydisperse medium. The particle density results were very close to theoretical values for lead spheres, whose relative deviation (RD) was -2.9 % and +0.1 % RD for the iron spheres. The RD of porosity was also low: -3.6 % for lead spheres and -1.2 % for iron spheres, in the comparison of procedures – using particle and porous medium densities and saturated volumetric water content – and monodisperse and polydisperse media.

Para além das fronteiras da química: relações entre filosofia, psicologia e ensino de química

The concepts of molecule and of molecular structure are so central to understand chemical phenomena that seems to be no doubt about the uniqueness of its meanings. Nevertheless, the idea that the world exhibits a multiform structure and that to different spheres of the world correspond different ways of knowing (Berger & Luckmann, 1967) has received support from different areas of scientific inquiry. Bachelard (1940, 1982) showed that a single philosophical doctrine is not enough to describe all the different ways of thinking when we try to explain a single concept. Wooley's question about the possibility of deducing the concept of molecular structure from quantum theory (Wooley, 1978) strengthened the feasibility of thinking the concept of molecule as a profile that encompasses different meanings. Moreover, research on students' learning of scientific concepts have brought to light that students use several ideas to explain scientific and everyday phenomena which are different from those learned in formal schooling. These ideas are not extinguished or replaced by scientific concepts, despite the efforts to do so in science classes. The common sense and scientific ways of understanding and talking about reality seems to be complementary in the same sense of the Bohr's complementarity (Halliday & Martin, 1993). So, we have to include in our profile of the concept of molecule not only scientific but also common sense zones. Drawing from Bachelard's notion of epistemological profile, from the history of science and from the research on children's ideas in science, we have developed the idea of a conceptual profile and used it to analyse basic scientific concepts, such as the concepts of matter and physical states of matter (Mortimer, 1995) and to investigate new ways to teach them. In the present paper, we will discuss the zones that might constitute a conceptual profile of molecule. The need of complementary views to account for the molecular structure in different contexts bring important issues for understanding and teaching chemistry, which will be discussed further in the article.

Construção de modelos para ilustração de estruturas moleculares em aulas de química

This paper describes the construction of a kit of molecular model for illustration of molecular structure in chemical class using cheap materials. The atoms were represented by plastic spheres and the bonds between the atoms were made from plastic straws which were cut in the required length using a scale of 1.6 cm corresponding to 100 pm. Examples of adaptations made in this kit for didactical application are given.

Nanocompósitos cerâmicos a partir do processo de moagem mecânica de alta energia

Pb/Ti, Sn and Mg-based nanocomposite materials were prepared by the high-energy mechanical milling of commercial powders. The surface of these ceramic compounds was strongly influenced by the doping, diameter of the milling spheres and time of the mechanical milling (amorphization process). Such milling leads to the formation of nanocrystalline materials. The mechanical processing parameters of these compounds were investigated through Brunauer, Emmett and Teller isotherms, wide angle X-ray diffraction, transmission electron microscopy and CO2 adsorption.

Imobilização de ferro (II) em matriz de alginato e sua utilização na degradação de corantes têxteis por processos Fenton

In this work Fenton and photo-Fenton processes for textile dye degradation were investigated using iron (II) immobilized in alginate spheres. Photomicrographs obtained by scanning electron microscopy showed an irregular and porous surface with a homogeneous distribution of iron. The Fenton process was used to evaluate the degradation efficiency of reactive dyes and this procedure showed a low degradation effect. The association of artificial visible light or solar radiation in the Fenton process (foto-Fenton process) showed degradation ratios of 70 and 80% respectively in 45 min. It was also observed that the iron-alginate matrix can be reused.

Co2 na desidrogenação oxidativa do etilbenzeno utilizando catalisadores compostos de óxido de ferro e óxido de alumínio

Materials containing aluminum and iron oxide were synthesized through the preparation of hybrid spheres and tested in the dehydrogenation of ethylbenzene in the presence of CO2. The catalytic results suggest that the high initial ethylbenzene conversion is due to the contribution of basic sites. These results also point to a competitive process between CO2 adsorption and the oxidative dehydrogenation of ethylbenzene for the basic sites (lattice oxygen). In spite of the coke deposition is originating from ethylbenzene and CO2, the amount of carbonaceous deposits was smaller with the presence of CO2, if compared with the dehydrogenation in the absence of CO2.

SÍNTESE E CARACTERIZAÇÃO DE COMPÓSITOS ORGÂNICO-INORGÂNICOS MACROPOROSOS PARA O SENSORIAMENTO DE H2O2

Electrodes modified with poly(5-amino-1-naphthol)/Prussian blue (poly(5-NH2-1-NAP)/PB) hybrid films are able to electrochemically reduce H2O2 in medium containing an excess of Na+ cations. This is an important advantage for biosensing applications over electrodes in which only conventionally (electro) deposited Prussian blue is present. Consequently, the aim of this work was to examine the application of templates of ordered arrays of colloidal poly(styrene) spheres (800, 450 and 100 nm in diameter) to produce inverse opal structures of poly(5-NH2-1-NAP)/PB hybrid platforms, in an effort to study the influence of the increase in surface area/volume ratio and higher exposition of the mediator active sites on material performance during H2O2 determination employing the different sized porous structures. Moreover, since the accentuated hydrophilic character of poly(5-NH2-1-NAP)/PB also allows H2O2 electrochemical reduction in inner active sites, issues concerning the amount of mediator electrodeposited on the electrode were also reflected in the observed results.

Resultados científicos do cruzeiro do "Baependi" e do "Vega" à Ilha da Trindade: contribuição para o conhecimento da plataforma insular da Ilha da Trindade

The oceanographic work realized during 10 days in the surroundings of the eruptive island of Trindade, 20º30'36" lat. S - 29º19'26" long. W, had as principal aim the determination of the insular plateau, whose knowledge was very insufficient. Thus were established some oceanographic stations and sounding lines were realized by means of an echobathymeter whose responses were initially verified with mechanical soundings obtaneid by means of a Thomson sounder. The insular plateau is very narrow and exhibits a sudden fall between the 100 and 120 m. depth line at 740 m. - 2950 m. from the coast. Its greatest depth is of 108,30 m. and its mean inclination is of 8,12%. The plateau of the island of Trindade is separated from that of the neighbouring group of Martim Yaz by great depths. The bottoms are rocky near the coast, the blocks having been produced by the rupture of the magmatic mass of the island. Further away from the coast, the size of the rocks gradually diminishes up to the fine sand thickness. In the litoral zone there are abundant tufts of living Lithothamnion with a rich associated flora and fauna, which partly covers the rocks themselves. Further off at sea, the spheres of the dead alga with its commensals are cimented together by sedimentation. The spheres are further broken up and become an integrating part of the sand. The results of the physical and chemical analyses of the sand bottoms are shown in tables 2 and 3. The coast is either of abrupt rocky walls falling down to sea level, or of shores, made of pebbles or of sand. Anyhow, there are frequently Lithothamnion terraces slightly inclinated towards the bottom (chemical analysis table 1).

Repair of the anophthalmic cavity of rats with synthetic hydroxyapatite

We placed spheres of synthetic hydroxyapatite (calcium chloride combined with sodium phosphate) in the eviscerated or enucleated orbital cavity of rats in order to evaluate the biocompatibility of this material with the orbital cavity. The study was conducted on 50 albino rats, 25 of which were submitted to enucleation and 25 to evisceration of one eye. The animals were sacrificed 7, 15, 21, 30 and 60 days after surgery and the orbital content was submitted to histopathological examination. A reaction of the young granulation tissue type was observed first. The hydroxyapatite was gradually surrounded by a granulomatous macrophage inflammatory response and covered with dense connective tissue that formed a sort of" mesh" septating and supporting progressively smaller blocks of the substance. The same type of reaction was observed in the enucleated and eviscerated cavities. We conclude that synthetic hydroxyapatite is an inert nonallergenic material which is appropriate for volume replacement in the anophthalmic cavity