Carla Rodrigues

Characterization of a bovine collagen–hydroxyapatite composite scaffold for bone tissue engineering

Different biomaterials have been used as scaffolds for bone tissue engineering. Here we characterize a biomaterial composed of sintered (1100 degrees C) and powdered hydroxyapatite (HA) and type I collagen (Coll), both of bovine origin, designed for osteoconductive and osteoinductive scaffolds. Coll/HA proportions were 1/2.6 and 1/1 (wet weight), and particles sizes varied from 200 to 400 microm. Vv (volume density) and Sv (surface to volume density) for the HA particles in the composite ranged from 0.48 +/- 0.06 to 0.55 +/- 0.02 and 5.090 +/- 0.545 to 6.366 +/- 0.289 microm(-1), respectively. Due to the relatively small changes in Vv and Sv, a macroporosity could be characterized for the biocomposite. X-ray diffraction and infrared spectroscopy showed that the sintered bone was composed essentially of HA with minimum additional groups such as surface calcium hydroxide, surface and crystal water, free carbon dioxide and possibly brushite. Mass spectrometry detected carbonates at A and B sites of HA, and weakly bound to the structure. Human osteoblasts adhered and spread on both the HA particle surface and the collagen fibers, which seemed to guide cells between adjacent particles. The biocomposite studied has several characteristics considered as ideal for its use as a scaffold for osteoconduction and osteoinduction.

A costela de Adão: diferenças sexuais a partir de Lévinas

This paper presents the thought of Emmanuel Levinas about women and about sex differences to explore what Jacques Derrida calls the two possibilities of reading Levinas. The first, androcentric, identifies the traditional hierarchical separation between male and female. The second possibility of reading Levinas, according to Derrida, sees the expansion of the meaning of women into the feminine, amplifying Levinass propositions of feminity as an opening to otherness. Levinas turns the feminine into a privileged figure of ethics and otherness. Derrida will depart from this idea of Levinas about the feminine to think of unconditional hospitality, radicalizing his view of openness to others.

Construindo Vera Cruz e desconstruindo gênero: aproximações entre Pedro Almodóvar e Judith Butler

Este artigo se propoe a uma aproximacao entre as proposicoes de desconstrucao da distincao sexo/genero tal qual proposta por Judith Butler com as questoes apresentadas no filme “A pele que habito”, do cineasta Pedro Almodovar. Neste dialogo, o trabalho debate questoes como o diagnostico de disforia de genero e o problema da essencializacao das categorias feminino/masculino e sua binaridade, a partir dos quais tematiza a normatividade de genero e autonomia do sujeito diante das normas.

Constructing Vera Cruz and deconstructing gender: an approximation between Pedro Almodovar and Judith Butler

Este artigo se propoe a uma aproximacao entre as proposicoes de desconstrucao da distincao sexo/genero tal qual proposta por Judith Butler com as questoes apresentadas no filme “A pele que habito”, do cineasta Pedro Almodovar. Neste dialogo, o trabalho debate questoes como o diagnostico de disforia de genero e o problema da essencializacao das categorias feminino/masculino e sua binaridade, a partir dos quais tematiza a normatividade de genero e autonomia do sujeito diante das normas.

Construyendo a Vera Cruz y deconstruyendo género: aproximaciones entre Pedro Almodóvar y Judith Butler

Este artigo se propoe a uma aproximacao entre as proposicoes de desconstrucao da distincao sexo/genero tal qual proposta por Judith Butler com as questoes apresentadas no filme “A pele que habito”, do cineasta Pedro Almodovar. Neste dialogo, o trabalho debate questoes como o diagnostico de disforia de genero e o problema da essencializacao das categorias feminino/masculino e sua binaridade, a partir dos quais tematiza a normatividade de genero e autonomia do sujeito diante das normas.

Brazilian Research Academy and Scientific Evidence on Calcium Phosphate Bone Grafts

Different types of bone grafts are available in Brazil due to the increase of use of biomaterials for hard tissue replacement. This study was designed to evaluate the scientific production of Brazilian research groups on safety and efficacy of calcium phosphate bone grafts of commercial use in Brazil. The calcium phosphate bone grafts approved for commercial use in Brazil were searched at the National Health Regulatory Agency’s database (ANVISA). The main leaders’ names of the Brazilian Research Groups on these health technologies were obtained by applying the search strategies to the National Council of Technological and Scientific Development’s database (CNPq). Afterwards, it was performed a systematic search of studies conducted by these leaders on calcium phosphate bone grafts and published from 2000 to May 2008 at the following databases: Medline, Lilacs and Scielo. Twenty-nine bone grafts composed by calcium phosphates were registered at Anvisa in May 2008. From those products, 17 and 12 were from imported and national origin respectively. There were twenty-four Brazilian research groups on calcium phosphate bone grafts whose scientific production consisted of 5 studies on bone grafts registered at Anvisa: 3 experiments conducted in animals on the Brazilian bovine bone graft Gen-Ox®, one prospective comparative study and one case report both evaluating the clinical performance of a national biomaterial composed by BMP, demineralized bovine bone, inorganic bovine bone and bovine collagen with the commercial name Gen-Tech® for dentistry applications and 6 months of follow-up. However, all the included studies had poor methodological quality and could not be used for further recommendations despite their good results. The scientific evidence produced by the Brazilian research groups on safety and efficacy of calcium phosphate bone grafts of commercial use in Brazil is still scant. Additional studies are necessary to evaluate these technologies.