Plasmodium vivax thrombospondin related adhesion protein: immunogenicity and protective efficacy in rodents and Aotus monkeys

The thrombospondin related adhesion protein (TRAP) is a malaria pre-erythrocytic antigen currently pursued as malaria vaccine candidate to Plasmodium falciparum. In this study, a long synthetic peptide (LSP) representing a P. vivax TRAP fragment involved in hepatocyte invasion was formulated in both Freund and Montanide ISA 720 adjutants and administered by IM and subcutaneous routes to BALB/c mice and Aotus monkeys. We measured specific humoral immune responses in both animal species and performed a sporozoite challenge in Aotus monkeys to assess the protective efficacy of the vaccine. After immunization both mice and Aotus seroconverted as shown by ELISA, and the specific anti-peptide antibodies cross reacted with the parasite in IFAT assays. Only two out of six immunized animals became infected after P. vivax sporozoite challenge as compared with four out of six animals from the control group. These results suggest that this TRAP fragment has protective potential against P. vivax malaria and deserves further studies as vaccine candidate.

CD40, autophagy and Toxoplasma gondii

Toxoplasmagondii represents a pathogen that survives within host cells by preventing the endosomal-lysosomal compartments from fusing with the parasitophorous vacuoles. The dogma had been that the non-fusogenic nature of these vacuoles is irreversible. Recent studies revealed that this dogma is not correct. Cell-mediated immunity through CD40 re-routes the parasitophorous vacuoles to the lysosomal compartment by a process called autophagy. Autophagosome formation around the parasitophorous vacuole results in killing of the T. gondii. CD40-induced autophagy likely contributes to resistance against T. gondii particularly in neural tissue.

Toxoplasma gondii in animals used for human consumption

Food-borne toxoplasmosis in humans may result from exposure to different stages of Toxoplasma gondii, in particular from the ingestion of tissue cysts or tachyzoites contained in meat, primary offal (viscera) or meat-derived products of many different animals, or the ingestion of sporulated oocysts that are contained in the environment and may contaminate food and water. Although the potential for transmission of the parasite to humans via food has been known for several decades, it is not known which routes are most important from a public health point of view. It is likely that transmission of the parasite to humans is influenced not only by the potential contamination of various food sources, but also by the individual behaviour of consumers in different ethnic groups and geographical regions. Most current methods for detection of T. gondii in meat-producing animals, in products of animal origin, or in the environment are insufficient because they do not allow quantification of infectious stages. Hence, most studies report only qualitative data from which it is difficult to assess the true risk of infection in individual cases. There is a need for quantitative data so that efficient strategies to reduce food-borne transmission of T. gondii to humans can be developed.

Molecular epidemiology of Candida albicans and Candida glabrata strains isolated from intensive care unit patients in Poland

Over the last decades, Candida spp have been responsible for an increasing number of infections, especially in patients requiring intensive care. Knowledge of local epidemiology and analysis of the spread of these pathogens is important in understanding and controlling their transmission. The aim of this study was to evaluate the genetic diversity of 31 Candida albicans and 17 Candida glabrata isolates recovered from intensive care unit patients from the tertiary hospital in Krakow between 2011-2012. The strains were typed by random amplified polymorphic DNA (RAPD) polymerase chain reaction using five primers (CD16AS, HP1247, ERIC-2, OPE-3 and OPE-18). The results of the present investigation revealed a high degree of genetic diversity among the isolates. No clonal relationship was found among the C. albicans strains, whereas two C. glabrata isolates were identical. The source of Candida infection appeared to be mostly endogenous; however, the presence of two clonal C. glabrata strains suggested the possibility of cross-transmission of these pathogens. Our study confirmed the high discriminatory power of the RAPD technique in the molecular typing of Candida clinical isolates. This method may be applied to the evaluation of transmission routes of pathogenic fungi on a local level.

Rotas de síntese e a homogeneidade dos precursores de mulita e cordierita

Multicomponent ceramics are mainly synthesized by conventional solid-state reaction route and sol-gel routes. In the sol-gel route, colloidal or polymeric gel are envolved. In this work, some principles of the chemistry of theses routes are discused and it is ilustrated a variety of strategies for obtaining a homogeneous multicomponent precursors.

Perspectives in the use of carbon dioxide

The mitigation of carbon dioxide is one of the scientific and technological challenges of the 2000s. Among the technologies that are under assessment, the recovery of carbon dioxide from power plants or industrial flue gases plays a strategic role. Recovered carbon dioxide can be either disposed in natural fields or used. The availability of large amounts of carbon dioxide may open new routes to its utilisation in biological, chemical and innovative technological processes. In this paper, the potential of carbon dioxide utilisation in the short-, medium-term is reviewed.

Síntese de poli(p-xililenos)

Poly(p-xylylenes), PPX, are a class of high performance insulating materials with many applications in the electronic component industry. We review herewith the most important synthetic routes to these polymers, described in the literature, since 1904.

Propriedades e aplicações de clusters trinucleares de carboxilatos de rutênio

A review with 94 references focusing on mu3-oxo-triruthenium carboxylate clusters is presented. The electronic, magnetic, electrochemical, and catalytic properties of these compounds are discussed. Main synthetic routes and structural characteristics, including their use as building blocks in supramolecular systems are described.

Preparação e caracterização de pós cerâmicos de aluminatos de lítio

The preparation of gamma-LiAlO2 by coprecipitation and sol-gel synthesis was investigated. Ceramic powders obtained by coprecipitation synthesis were prepared from aqueous solutions of aluminum and lithium nitrates using sodium hydroxide as precipitant agent. By sol-gel synthesis, the ceramic powders were prepared from hydrolysis of aluminum isopropoxide. The materials obtained by two routes of synthesis were dried at 80ºC and calcined at 550, 750, 950 and 1150ºC. The characterization was done by X-ray diffraction, infrared spectroscopy, emission and absorption atomic spectrometry, helium picnometry, specific surface area (BET method) and scanning electronic microscopy. Mixtures of crystalline phases were obtained by coprecipitation synthesis: 80ºC- LiAl2(OH)7.2H2O + Al(OH)3; 550 and 750ºC- alpha-LiAlO2 + eta-Al2O3; 950 and 1150ºC- gamma-LiAlO2 + LiAl5O8. Chemical analysis showed molar ration Al/Li @ 3. Crystalline single-phases were obtained by sol-gel synthesis above 550ºC: 550ºC-alpha-LiAlO2; 750, 950 and 1150ºC-gamma-LiAlO2. These powders presented molar ration Al/Li @ 1. Thus, gamma-LiAlO2 crystalline phase was obtained at 750ºC by sol-gel synthesis while by coprecipitation synthesis, a mixture of crystalline phases was obtained. These results showed the superiority of the sol-gel synthesis for the preparation of pure gamma-LiAlO2.

Híbridos inorgânico-orgânicos derivados da reação de filossicatos com organossilanos

Silylation reactions involving hydroxylated surfaces are an important route for synthesis of new materials that could present selected properties, for application in different areas such as catalysis, chromatography, adsorption and electrochemistry. An overview of many synthetic routes, comprising organosilanes to yield phyllosilicates is now presented.

Microemulsões: estrutura e aplicações como sistema de liberação de fármacos

Depending on formula composition, microemulsions may be used as a vehicle for drug administration. In this work the main applicable parameters used in the development of pharmaceutical microemulsions (ME) are analyzed. The conceptual description of the system, theoretical parameters related to formation of internal phases and some aspects of ME stability are described. The pseudo ternary phase diagram is used to characterize ME boundaries and to describe different structures in several regions of the diagram. Some applications of ME as drug delivery systems for different administration routes are also analyzed. ME offer advantages as drug delivery systems, because they favor drug absorption, being in most cases faster and more efficient than other methods in delivering the same amount of drug.

Óxido misto de ítrio-alumínio dopado com Eu(III)

In this work, we report the synthesis and the photoluminescence features of Eu(III)-doped yttrium-aluminium oxide obtained by non-hydrolytic sol-gel routes. After heating the powders above 600 ºC the XRD patterns show the presence of the Y4Al2O9 (YAM) and Y3Al5O12 (YAG) phases. At 800 and at 1500 ºC the PL spectra display the Eu(III) lines characteristic of the YAM monoclinic phase. The 5D0->7F2 transition is favored relatively to the 5D0->7F1 lines. However, at 1100 ºC the cubic YAG is the preferential phase and the 5D0->7F1 transition dominates the spectrum. The Eu(III) ions lie in a centrosymmetrical site. The different solvents used in the sol-gel synthesis also change the relative proportion between these two phases. This is monitored analyzing the modifications in the relative intensity between the 5D0->7F2 and the 5D0->7F1 transitions.

Bisfosfonatos: síntese, análises químicas e aplicações farmacológicas

Bisphosphonates are drugs that have been widely used in different bone diseases, and have recently been used successfully against many parasites. Various synthetic routes to prepare different types of bisphosphonates have been described, with distinct potency and pharmacological activity. A number of analytical techniques are currently being used to analyze these drugs; among these, the high performance liquid chromatography (HPLC), with different systems of detection, is worth highlighting. However, the development of more sensitive methods is still necessary, once they are essential for bioavailability and bioequivalence studies. This paper reports the major synthesis routes, chemical analysis methodologies and pharmacological applications of bisphosphonates.

Materiais híbridos orgânico-inorgânicos: preparação e algumas aplicações

The preparation and application of organic-inorganic hybrid materials are under fast development and constitute an interesting research topic on account of the versatility and wide range of applications offered by these materials. These properties can be achieved due to the mixture of the components at the molecular level. The present review covers the state of the art, the most useful preparation routes and the potential applications of these materials.

Heterociclos 1,2,3-triazólicos: histórico, métodos de preparação, aplicações e atividades farmacológicas

The 1,2,3-triazole, known since the end of 19th century, is a very widely used heterocyclic system present in many synthetic substances and commercial pharmaceutical compounds. In fact, 1,2,3-triazoles show several applications in many areas especially as medicines against many diseases like cancer, AIDS, Parkinson and Alzheimer. Nowadays there is a large variety of known methods to obtain these heterocyclic compounds comprising mainly three synthetic routes. Nevertheless, there is no article that gives an objective overview of the synthetic methods for obtaining these kinds of azoheterocycles. This paper presents a brief history of this class of compounds, and a synthetic discussion concerning the main synthetic methods for its preparation, such as cyclization through hydrazones, concerted cycloadditon [2+3] and pseudopericyclic cyclization - and some others of restricted application, but also important. Finally, this paper also provides a brief overview on pharmacological applications of some 1,2,3-triazoles.