Organismos transgênicos no Brasil: regular ou desregular?

The risk analysis of GMOs or transgenic plants follows international protocols concer-ning with possible damages (adverse effects), the form in which damages occur (risks), the significant risks deserving a thorough analysis, and which way the identified risk is to be observed and measured (assessment). Just like what has happened in Brazil, risk analyses conducted in other countries in the last fifteen years have never found any market-released products with adverse effects to human or animal health or to the environment. The excessive regulation favors big companies, which have resources and time to meet all regulatory demands. On the other hand, small-sized companies or state companies such as Embrapa do not have enough budgeting to comply with the overburdening regulation. Thus, taking into account the experience of other countries and also its own experience, Brazil should address this debate with more rationality, and start de-regulating what is over-regulated. Transgenic plants are harmless, and also favorable to the economy and to the environment. It has been proved that they reduce water use as they demand less insecticide, and also the use of diesel oil, thus reducing CO2 emission into the atmosphere.A análise de risco de OGM ou transgênicos segue protocolos internacionais através das quais se pergunta sobre o possível dano (efeito adverso), a forma de aparecimento do dano (riscos), os riscos significativos que mereçam análise detalhada e de que forma o risco identificado será observado e medido (avaliação). Assim como no Brasil, análises de risco efetuadas em outros países nos últimos quinze anos nunca evidenciaram, nos produtos liberados, efeitos adversos à saúde humana e animal ou ao ambiente. O excesso de regulamentação favorece as grandes empresas que têm recursos e tempo para atender a todas as demandas regulatórias. No entanto, pequenas empresas ou estatais como a Embrapa não têm orçamento para cumprir com os exageros do excesso de regulamentação. Por isso, o Brasil, tendo em vista a experiência dos outros países, além de sua própria experiência, deve introduzir mais racionalidade no debate e começar a desregular o que está regulado em demasia. As plantas transgênicas, além de inócuas, trazem vantagens econômicas e ao meio ambiente. Comprovadamente, reduzem o uso de água por exigir menos inseticidas e economizam o uso de óleo diesel reduzindo a emissão de CO2 na atmosfera

Selection of binding targets in parasites using phage-display and aptamer libraries in vivo and in vitro

Parasite infections are largely dependent on interactions between pathogen and different host cell populations to guarantee a successful infectious process. This is particularly true for obligatory intracellular parasites as Plasmodium, Toxoplasrna, and Leishmania, to name a few. Adhesion to and entry into the cell are essential steps requiring specific parasite and host cell molecules. the large amount of possible involved molecules poses additional difficulties for their identification by the classical biochemical approaches. in this respect, the search for alternative techniques should be pursued. Among them two powerful methodologies can be employed, both relying upon the construction of highly diverse combinatorial libraries of peptides or oligonucleotides that randomly bind with high affinity to targets on the cell surface and are selectively displaced by putative ligands. These are, respectively, the peptide-based phage display and the oligonucleotide-based aptamer techniques. the phage display technique has been extensively employed for the identification of novel ligands in vitro and in vivo in different areas such as cancer, vaccine development, and epitope mapping. Particularly, phage display has been employed in the investigation of pathogen host interactions. Although this methodology has been used for some parasites with encouraging results, in trypanosomatids its use is, as yet, scanty. RNA and DNA aptamers, developed by the SELEX process (Systematic Evolution of Ligands by Exponential Enrichment), were described over two decades ago and since then contributed to a large number of structured nucleic acids for diagnostic or therapeutic purposes or for the understanding of the cell biology. Similarly to the phage display technique scarce use of the SELEX process has been used in the probing of parasite host interaction. in this review, an overall survey on the use of both phage display and aptamer technologies in different pathogenic organisms will be discussed. Using these techniques, recent results on the interaction of Trypanosoma cruzi with the host will be highlighted focusing on members of the 85 kDa protein family, a subset of the gp85/TS superfamily.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo, Dept Ciencias Biol, São Paulo, BrazilUniv São Paulo, Inst Quim, Dept Bioquim, BR-05508900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Biol, São Paulo, BrazilFAPESP: FAPESP 2010/15042-2FAPESP: FAPESP 2009/52646-6Web of Scienc

Adhesion of Trypanosoma cruzi Trypomastigotes to Fibronectin or Laminin Modifies Tubulin and Paraflagellar Rod Protein Phosphorylation

Background: The unicellular parasite Trypanosoma cruzi is the causative agent of Chagas disease in humans. Adherence of the infective stage to elements of the extracellular matrix (ECM), as laminin and fibronectin, is an essential step in host cell invasion. Although members of the gp85/TS, as Tc85, were identified as laminin and fibronectin ligands, the signaling events triggered on the parasite upon binding to these molecules are largely unexplored. Methodology/Principal Findings: Viable infective parasites were incubated with laminin, fibronectin or bovine serum albumin for different periods of time and the proteins were separated by bidimensional gels. The phosphoproteins were envisaged by specific staining and the spots showing phosphorylation levels significantly different from the control were excised and identified by MS/MS. The results of interest were confirmed by immunoblotting or immunoprecipitation and the localization of proteins in the parasite was determined by immunofluorescence. Using a host cell-free system, our data indicate that the phosphorylation contents of T. cruzi proteins encompassing different cellular functions are modified upon incubation of the parasite with fibronectin or laminin. Conclusions/Significance: Herein it is shown, for the first time, that paraflagellar rod proteins and alpha-tubulin, major structural elements of the parasite cytoskeleton, are predominantly dephosphorylated during the process, probably involving the ERK1/2 pathway. It is well established that T. cruzi binds to ECM elements during the cell infection process. The fact that laminin and fibronectin induce predominantly dephosphorylation of the main cytoskeletal proteins of the parasite suggests a possible correlation between cytoskeletal modifications and the ability of the parasite to internalize into host cells.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2009/52646-6]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [303539/2005-4

Role of the gp85/Trans-Sialidases in Trypanosoma cruzi Tissue Tropism: Preferential Binding of a Conserved Peptide Motif to the Vasculature in Vivo

Background: Transmitted by blood-sucking insects, the unicellular parasite Trypanosoma cruzi is the causative agent of Chagas' disease, a malady manifested in a variety of symptoms from heart disease to digestive and urinary tract dysfunctions. the reasons for such organ preference have been a matter of great interest in the field, particularly because the parasite can invade nearly every cell line and it can be found in most tissues following an infection. Among the molecular factors that contribute to virulence is a large multigene family of proteins known as gp85/trans-sialidase, which participates in cell attachment and invasion. But whether these proteins also contribute to tissue homing had not yet been investigated. Here, a combination of endothelial cell immortalization and phage display techniques has been used to investigate the role of gp85/trans-sialidase in binding to the vasculature.Methods: Bacteriophage expressing an important peptide motif (denominated FLY) common to all gp85/trans-sialidase proteins was used as a surrogate to investigate the interaction of this motif with the endothelium compartment. for that purpose phage particles were incubated with endothelial cells obtained from different organs or injected into mice intravenously and the number of phage particles bound to cells or tissues was determined. Binding of phages to intermediate filament proteins has also been studied.Findings and Conclusions: Our data indicate that FLY interacts with the endothelium in an organ-dependent manner with significantly higher avidity for the heart vasculature. Phage display results also show that FLY interaction with intermediate filament proteins is not limited to cytokeratin 18 (CK18), which may explain the wide variety of cells infected by the parasite. This is the first time that members of the intermediate filaments in general, constituted by a large group of ubiquitously expressed proteins, have been implicated in T. cruzi cell invasion and tissue homing.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniv São Paulo, Inst Quim, Dept Bioquim, BR-01498 São Paulo, BrazilUniv Texas MD Anderson Canc Ctr, David H Koch Ctr, Houston, TX 77030 USAUniv Texas MD Anderson Canc Ctr, Dept Canc Biol, Houston, TX 77030 USAUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilFAPESP: 2004/03303-5FAPESP: 2008/54.806-8Web of Scienc

Reprogramming of Trypanosoma cruzi metabolism triggered by parasite interaction with the host cell extracellular matrix.

Trypanosoma cruzi, the etiological agent of Chagas' disease, affects 8 million people predominantly living in socioeconomic underdeveloped areas. T. cruzi trypomastigotes (Ty), the classical infective stage, interact with the extracellular matrix (ECM), an obligatory step before invasion of almost all mammalian cells in different tissues. Here we have characterized the proteome and phosphoproteome of T. cruzi trypomastigotes upon interaction with ECM (MTy) and the data are available via ProteomeXchange with identifier PXD010970. Proteins involved with metabolic processes (such as the glycolytic pathway), kinases, flagellum and microtubule related proteins, transport-associated proteins and RNA/DNA binding elements are highly represented in the pool of proteins modified by phosphorylation. Further, important metabolic switches triggered by this interaction with ECM were indicated by decreases in the phosphorylation of hexokinase, phosphofructokinase, fructose-2,6-bisphosphatase, phosphoglucomutase, phosphoglycerate kinase in MTy. Concomitantly, a decrease in the pyruvate and lactate and an increase of glucose and succinate contents were detected by GC-MS. These observations led us to focus on the changes in the glycolytic pathway upon binding of the parasite to the ECM. Inhibition of hexokinase, pyruvate kinase and lactate dehydrogenase activities in MTy were observed and this correlated with the phosphorylation levels of the respective enzymes. Putative kinases involved in protein phosphorylation altered upon parasite incubation with ECM were suggested by in silico analysis. Taken together, our results show that in addition to cytoskeletal changes and protease activation, a reprogramming of the trypomastigote metabolism is triggered by the interaction of the parasite with the ECM prior to cell invasion and differentiation into amastigotes, the multiplicative intracellular stage of T. cruzi in the vertebrate host

Meta-analysis: surveillance with ultrasound for early-stage hepatocellular carcinoma in patients with cirrhosis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74816/1/j.1365-2036.2009.04014.x.pd

Spielen Statine eine Rolle als adjuvante Therapie bei Entzündung? / Do statins play a role as an adjuvant therapy in inflammation?

Despite recent advances in management of patients in intensive care units, sepsis and septic shock are the major causes of morbidity and mortality. Prompt and adequate antibiotic therapy accompanied by surgical removal of the infectious material are the first-line therapy of choice. In addition, various immunomodulatory treatments have been investigated during the past decades. However, despite promising results in studies with animal models, studies in humans with antibodies against lipopolysaccharide (LPS), tumor necrosis factor and interleukin-1 have not been successful. In addition, high doses of steroids, immunoglobulins or antibodies against LPS and cytokines did not reduce mortality, probably owing to timing and dosage of these drugs. Prophylactic administration of immunomodulatory drugs cannot be recommended due to severe adverse effects. However, owing to pleiotropic effects of statins this class of cholesterol lowering drugs has been suggested to be beneficial as adjuvant therapy for sepsis. The present review summarizes the pathophysiology of sepsis as well as experimental and clinical evidence for the use of statins in sepsis.Trotz der Fortschritte der Medizin stellen schwere Entzündungsreaktionen wie die Sepsis eine wesentliche Ursache für Mortalität und Morbidität auf Intensivstationen dar. Zur kausalen Therapie gehört neben der Beseitigung der auslösenden Ursache durch chirurgische Maßnahmen vor allem eine effektive Antibiose. Weiterhin werden supportive Maßnahmen wie Kreislaufunterstützung, Nierenersatztherapie, Therapie von Gerinnungsstörungen und metabolischer Entgleisung zur Therapie eingesetzt. Darüber hinaus wurde in den vergangenen Jahren eine Vielzahl von immunomodulatorischen Therapien untersucht. Hierzu gehören neutralisierende Antikörper gegen Endotoxin oder proinflam-matorische Zytokine, Kortison, Immunglobuline und spezifische Gerinnungsinhibitoren. Neuere Studien weisen darauf hin, dass Statine (HMG-CoA-Reduktase-Inhibitoren) antientzündliche Wirkung haben und eine andauernde Statintherapie mit verminderter Inzidenz bakterieller Infektionen assoziiert ist. Aus diesem Grund wurden Statine als neue adjuvante Therpaie bei schweren Entzündungen und Sepsis vorgeschlagen. Im Gegensatz zu anderen antientzündlichen Therapien wäre hier auch ein prophylaktischer Einsatz bei Hochrisikopatienten, zum Beispiel vor elektiven chirurgischen Eingriffen, möglich. In der vorliegenden Arbeit sind die pathophysiologischen Grundlagen der Sepsis sowie die experimentelle Hintergründe und die ersten klinischen Daten zum Einsatz der Statine bei Sepsis zusammengefasst

The Heart Is an Early Target of Anthrax Lethal Toxin in Mice: A Protective Role for Neuronal Nitric Oxide Synthase (nNOS)

Anthrax lethal toxin (LT) induces vascular insufficiency in experimental animals through unknown mechanisms. In this study, we show that neuronal nitric oxide synthase (nNOS) deficiency in mice causes strikingly increased sensitivity to LT, while deficiencies in the two other NOS enzymes (iNOS and eNOS) have no effect on LT-mediated mortality. The increased sensitivity of nNOS−/− mice was independent of macrophage sensitivity to toxin, or cytokine responses, and could be replicated in nNOS-sufficient wild-type (WT) mice through pharmacological inhibition of the enzyme with 7-nitroindazole. Histopathological analyses showed that LT induced architectural changes in heart morphology of nNOS−/− mice, with rapid appearance of novel inter-fiber spaces but no associated apoptosis of cardiomyocytes. LT-treated WT mice had no histopathology observed at the light microscopy level. Electron microscopic analyses of LT-treated mice, however, revealed striking pathological changes in the hearts of both nNOS−/− and WT mice, varying only in severity and timing. Endothelial/capillary necrosis and degeneration, inter-myocyte edema, myofilament and mitochondrial degeneration, and altered sarcoplasmic reticulum cisternae were observed in both LT-treated WT and nNOS−/− mice. Furthermore, multiple biomarkers of cardiac injury (myoglobin, cardiac troponin-I, and heart fatty acid binding protein) were elevated in LT-treated mice very rapidly (by 6 h after LT injection) and reached concentrations rarely reported in mice. Cardiac protective nitrite therapy and allopurinol therapy did not have beneficial effects in LT-treated mice. Surprisingly, the potent nitric oxide scavenger, carboxy-PTIO, showed some protective effect against LT. Echocardiography on LT-treated mice indicated an average reduction in ejection fraction following LT treatment in both nNOS−/− and WT mice, indicative of decreased contractile function in the heart. We report the heart as an early target of LT in mice and discuss a protective role for nNOS against LT-mediated cardiac damage