Eduardo Galembeck

Effects of polyoxyethylene chain length on erythrocyte hemolysis induced by poly[oxyethylene (n) nonylphenol] non-ionic surfactants.

The effects of three different poly[oxyethylene (n) nonylphenols], n = 9.5, 20 and 100 oxyethylene (EO) units, on erythrocyte hemolysis and on the fluidity of the erythrocyte membrane were studied. The three different surfactants showed different effects. The surfactant with average n = 9.5 EO units (C9E9) shows a biphasic effect: at low concentrations it protects erythrocytes against hypotonic hemolysis, but at higher concentrations it induces hemolysis both in isotonic and hypotonic buffers. C9E20 does not affect the erythrocyte membrane resistance to hemolysis, independent of the buffer osmolarity; this detergent did not show a hemolytic effect. C9E100 is an effective protective agent against hypotonic hemolysis, in concentration > 2 x 10(-4) M. EPR spectroscopy of spin-labeled stearic acid indicated that the three different surfactants increase the fluidity of erythrocyte ghost membranes. At the higher C9E20 and C9E100 surfactant concentrations in the presence of membrane ghosts, spin-label is located in the surfactant micelles. In the case of the hemolytic concentrations of C9E9, mixed (surfactant plus phospholipid) micelles are formed. These results suggest that C9E9 has a higher affinity for membrane phospholipids, which accounts for its lytic activity. The protective effect of C9E100 is assigned to the osmotic buffering of the liquid surrounding the cell membrane, due to the large polar chains anchored to the membrane outer monolayer but other mechanisms previously considered in the literature may also be effective.

Phosphoproteome Reveals an Atlas of Protein Signaling Networks During Osteoblast Adhesion

Cell adhesion on surfaces is a fundamental process in the emerging biomaterials field and developmental events as well. However, the mechanisms regulating this biological process in osteoblasts are not fully understood. Reversible phosphorylation catalyzed by kinases is probably the most important regulatory mechanism in eukaryotes. Therefore, the goal of this study is to assess osteoblast adhesion through a molecular prism under a peptide array technology, revealing essential signaling proteins governing adhesion‐related events. First, we showed that there are main morphological changes on osteoblast shape during adhesion up to 3 h. Second, besides classical proteins activated upon integrin activation, our results showed a novel network involving signaling proteins such as Rap1A, PKA, PKC, and GSK3β during osteoblast adhesion on polystyrene. Third, these proteins were grouped in different signaling cascades including focal adhesion establishment, cytoskeleton rearrangement, and cell‐cycle arrest. We have thus provided evidence that a global phosphorylation screening is able to yield a systems‐oriented look at osteoblast adhesion, providing new insights for understanding of bone formation and improvement of cell–substratum interactions. Altogether, these statements are necessary means for further intervention and development of new approaches for the progress of tissue engineering. J. Cell. Biochem. 109: 957–966, 2010.

A quick guide for computer-assisted instruction in computational biology and bioinformatics.

Computational Biology and Bioinformatics (CBB) are indispensable components in the training of life scientists [1]–[3]. Current curricula in the life sciences should prepare graduates who master quantitative and computer skills for increased levels of performance [4]–[6]. Equally important is that the application of the curricula is driven by an appropriate instructional paradigm and effective learning experiences. Teaching and learning with computers bring specific issues that should be considered beforehand by any instructor. The following Quick Guide for Computer-Assisted Instruction (CAI) outlines ten principles for effective teaching. The principles are aligned with current developments on human cognition and learning [7] and have been drawn from our own experience using CAI in seminars, tutorials, and distance education, in courses on Molecular Life Sciences at the undergraduate level, taught to majors in biology or in other subjects (e.g., nutrition, teaching of physics and chemistry, teaching of biology, sports). The Guide refers to the preparation, presentation, and assessment of CAI. It should be an aid for those who teach CBB with CAI in class, and it is expected to stimulate student motivation and deeper learning in CBB, thus making class time more effective and improving satisfaction of both students and instructors.

Adapting a Biochemistry Course to Distance Education

Internet‐based distance education seems to be an attractive alternative to offer courses dealing with specific topics that are not conveniently explored in undergraduate courses. This is a good way to provide access to the recent and updated discoveries in this research area and to reach people who could not take the classes in the traditional mode. Using the communication advantages available via the Internet, we adapted the course “Biochemistry of Nutrition,” first offered as a summer course to be entirely carried out at distance. The adaptation explored the use of online tools such as E‐mail communication among students and teachers, computer conferencing in small groups to discuss specific subjects, and texts and software downloads to be used as main references. Graduate students had their first real experience as teachers, which proved to be very productive for both the development of the Internet version of the course and their integration with undergraduate students.

Different energy sources in sports: Introductory software†

This work describes software designed to promote the association between the content of a basic undergraduate biochemistry course and the professional activities of physical education students. The software contains three main content sections: (A) Structure of skeletal muscle, (B) Contraction mechanism, and (C) Adaptations to physical exercise. A fourth section asks questions of the students. The software offers students a brief introduction on muscle structure and function, focusing on the energy sources required by different kinds of physical activities. The software was field tested at Universidade Estadual de Campinas (Unicamp), Brazil and has been adopted by several Brazilian universities. The students are required to examine the software, to discuss its contents, and to produce a list of questions arising from their work with the software. These questions are answered during the development of the curriculum, thereby connecting biochemical knowledge with the energetic needs for the practice of sports.

Chave de identificação de espécies do estrato arbóreo da Mata Atlântica em Ubatuba (SP), com base em caracteres vegetativos

The identification key was developed taking into account the herbarium specimens from the species of the arboreal stratum sampled, with at least 4.8 cm DBH, in two stretches of Lower Montane Rain Forest. Only morphological vegetative characters were used, such as phyllotaxy, leaf shape, presence or absence of stipules, trichomes and glands, and other aspects relevant to the species identification, besides field observations. The key comprises 193 (4 without identification) species belonging to 114 genera and 50 botanical families, and an interactive electronic version is available online at the site http://www.gama.ib.unicamp.br/gama/index.php.

SUR1 Receptor Interaction with Hesperidin and Linarin Predicts Possible Mechanisms of Action of Valeriana officinalis in Parkinson

Parkinson’s disease (PD) is one of the most common neurodegenerative disorders. A theoretical approach of our previous experiments reporting the cytoprotective effects of the Valeriana officinalis compounds extract for PD is suggested. In addiction to considering the PD as a result of mitochondrial metabolic imbalance and oxidative stress, such as in our previous in vitro model of rotenone, in the present manuscript we added a genomic approach to evaluate the possible underlying mechanisms of the effect of the plant extract. Microarray of substantia nigra (SN) genome obtained from Allen Brain Institute was analyzed using gene set enrichment analysis to build a network of hub genes implicated in PD. Proteins transcribed from hub genes and their ligands selected by search ensemble approach algorithm were subjected to molecular docking studies, as well as 20 ns Molecular Dynamics (MD) using a Molecular Mechanic Poison/Boltzman Surface Area (MMPBSA) protocol. Our results bring a new approach to Valeriana officinalis extract, and suggest that hesperidin, and probably linarin are able to relieve effects of oxidative stress during ATP depletion due to its ability to binding SUR1. In addition, the key role of valerenic acid and apigenin is possibly related to prevent cortical hyperexcitation by inducing neuronal cells from SN to release GABA on brain stem. Thus, under hyperexcitability, oxidative stress, asphyxia and/or ATP depletion, Valeriana officinalis may trigger different mechanisms to provide neuronal cell protection.

Oxygen consumption by isolated mitochondria: Software for planning and interpreting experiments

Abstract A computer program for teaching is described which stimulates oxygen consumption by isolated mitochondria. The effects of different compounds (substrates, inhibitors, uncouplers) may be tested. Results from evaluation with 166 undergraduate and 11 postgraduate students are presented.

Mobile Applications in Cell Biology Present New Approaches for Cell Modelling

Cell biology apps were surveyed in order to identify whether there are new approaches for modelling cells allowed by the new technologies implemented in tablets and smartphones. A total of 97 apps were identified in 3 stores surveyed (Apple, Google Play and Amazon), they are presented as: education 48.4%, games 26.8% and medicine 15.4%. The apps were arranged by representation similarities of the cell models, and then the groups were nominated. The name of each one was based in recurrent terms on the apps descriptions and the definition is grounded in the literature. Thus, we categorized those apps in six modelling groups, not mutually exclusive: 32% three-dimensional, 25% bi-dimensional, 14% realistic, 14% animation, 11% scale and 4% playful. Each model has unique characteristics. Three-dimensional models can present proportional scales of organelles that allow immersion in the cell model. Realistic models and animations can be used to explore the dynamics of the cell functioning. The cell models designed for smartphones and tablets bring handling capabilities not found in computers and notebooks; they also have the potential to deliver content with high levels of interactivity and are accessible anytime and anywhere. Regarding the applicability of the cell models available in the apps, this paper offers some suggestions of classroom use based on the features of the models and examples found in the literature.

Radicais livres de oxigênio: um software introdutório

Though Free Radicals is one of the most frequently explored scientific subjects in mass communication media, the topic is absent of many Biochemistry introductory courses, especially those in which the students do not have a good chemical background. To overcome this contradictory situation we have developed a software treating this topic in a very simple way. The software is divided in four sections: (1) definition and description of free radicals, (2) production pathways, (3) mechanism of action and (4) enzymatic and non enzymatic protection. The instructional capacity of the software has been both qualitative and quantitatively evaluated through its application in undergraduate courses. The software is available in the INTERNET at the site: http://www.unicamp.br/ib/bioquimica/ensino.