Anticorpos contra LDL-ox e síndrome coronariana aguda

FUNDAMENTO: A oxidação da lipoproteína de baixa densidade (LDL-ox) induz à formação de epítopos imunogênicos na molécula. A presença de autoanticorpos contra a LDL-ox tem sido demonstrada no soro de pacientes com doença arterial coronariana (DAC). Contudo, o papel desses autoanticorpos na fisiopatologia das síndromes coronarianas agudas (SCA) e o seu significado clínico permanecem indefinidos. OBJETIVO: Avaliar a associação entre autoanticorpos contra a LDL-ox e SCA. MÉTODOS: Os títulos de imunoglobulina G autoanticorpos contra a LDL-ox por cobre (antiLDL-ox) e contra o peptídeo sintético D derivado da apolipoproteína B (antipeptD) foram determinados por ensaio imunoenzimático (ELISA) em 90 pacientes, nas primeiras 12h de SCA (casos) e em 90 pacientes com DAC crônica (controles). RESULTADOS: Os resultados mostraram que os títulos de antiLDL-ox foram significativamente mais elevados (p = 0,017) nos casos (0,40 ± 0,22), do que nos controles (0,33 ± 0,23). Por outro lado, os títulos de antipeptD foram significativamente menores (p < 0,01) nos casos (0,28 ± 0,23) do que nos controles (0,45 ± 0,30). A diferença dos títulos de ambos anticorpos entre os dois grupos estudados foi independente de idade, sexo, hipertensão arterial, diabete melito, dislipidemia, índice de massa corporal, tabagismo, perfil lipídico, uso de estatinas e história familiar de DAC. CONCLUSÃO: Os resultados mostraram que os títulos de antiLDL-ox foram significativamente mais elevados nos pacientes com síndrome coronariana aguda quando comparados aos pacientes com doença arterial coronariana e podem estar associados à instabilidade da placa aterosclerótica.

Synthesis of Fe/Ti oxides from a single source alkoxide precursor under inert atmosphere

The heterometal alkoxide [FeCl{Ti2(OPr i)9}] (1) was employed as a single source precursor for the preparation of Fe/Ti oxides under inert atmosphere. Three different synthetic procedures were adopted in the processing of 1, either employing aqueous HNO3 or HCl solutions, or in the absence of mineral acids. Products were characterised by powder X-ray diffractometry, scanning electron microscopy combined with energy dispersive X-ray spectroscopy (SEM/EDS) and Raman, electron paramagnetic resonance (EPR) and Mössbauer spectroscopies. Oxide products contained titanium(IV) and either iron(III) or iron(II), depending on reaction conditions and thermal treatment temperatures. An interesting iron(III)→iron(II) reduction was observed at 1000 ºC in the HNO3-containing system, leading to the detection of ilmenite (FeTiO3). SEM/EDS studies revealed a highly heterogeneous metal distribution in all products, possibly related to the presence of a significant content of carbon and of structural defects (oxygen vacancies) in the solids.

Fontes vegetais naturais de antioxidantes

Growing knowledge on the health-promoting impact of antioxidants in everyday foods, combined with the assumption that a number of common synthetic preservatives may have hazardous side effects has led to increased investigations in the field of natural antioxidants, principally those found in plants. Food industries normally discard plant residues that could benefit the human health and diminish undesirable environmental impact. Once estimated the content of antioxidants in these residues, advantageous economical and social alternatives to the discard are possible, for example, their use for preparation of nutraceuticals to be offered to low-income populations. We present here a broad, although not complete, account of the continuously growing knowledge on the antioxidant capacity of whole fruits, seeds and peels, cereals, vegetal oils and aromatic plants, at several physical forms, as well as a description of the usual methods for evaluating their antioxidant capacity and examples of agroindustrial processes that could be harnessed for the production of antioxidant supplement food, along with research perspectives in the area.

Eletrodos modificados por hidróxido de níquel: um estudo de revisão sobre suas propriedades estruturais e eletroquímicas visando suas aplicações em eletrocatálise, eletrocromismo e baterias secundárias

The present review paper describes the main features of nickel hydroxide modified electrodes covering its structural and electrochemical behavior and the newest advances promoted by nanostructured architectures. Important aspects such as synthetic procedures and characterization techniques such as X-Ray diffraction, Raman and Infrared spectroscopy, Electronic Microscopy and many others are detailed herein. The most important aspect concerning nickel hydroxide is related to its great versatility covering different fields in electrochemical-based devices such as batteries, electrocatalytic systems and electrochromic electrodes, the fundamental issues of these devices are also commented. Finally, some of the newest advances achieved in each field by the incorporation of nanomaterials will be shown.

Spectroscopic characterization of schiff base-copper complexes immobilized in smectite clays

Herein, the immobilization of some Schiff base-copper(II) complexes in smectite clays is described as a strategy for the heterogenization of homogeneous catalysts. The obtained materials were characterized by spectroscopic techniques, mostly UV/Vis, EPR, XANES and luminescence spectroscopy. SWy-2 and synthetic Laponite clays were used for the immobilization of two different complexes that have previously shown catalytic activity in the dismutation of superoxide radicals, and disproportionation of hydrogen peroxide. The obtained results indicated the occurrence of an intriguing intramolecular redox process involving copper and the imine ligand at the surface of the clays. These studies are supported by computational calculations.

Natural occurrence, biological activities and synthesis of eight-, nine-, and eleven-membered ring lactones

The natural occurrence, biological activities and synthetic approaches to natural eight-, nine-, and eleven-membered lactones is reviewed. These medium ring lactones are grouped according to ring size, and their syntheses are discussed. The structures of some natural products early identified as medium-ring lactones were revised after total synthesis.

Metal-free synthesis of indanes by iodine(III)-mediated ring contraction of 1, 2-dihydronaphthalenes

A metal-free protocol was developed to synthesize indanes by ring contraction of 1, 2-dihydronaphthalenes promoted by PhI(OH)OTs (HTIB or Koser's reagent). This oxidative rearrangement can be performed in several solvents (MeOH, CH3CN, 2 , 2, 2-trifluoroethanol (TFE), 1 , 1, 1, 3, 3, 3-hexafluoroisopropanol (HFIP), and a 1:4 mixture of TFE:CH2Cl2) under mild conditions. The ring contraction diastereoselectively gives functionalized trans-1, 3-disubstituted indanes, which are difficult to obtain in synthetic organic chemistry

Herdeiros e vítimas da "conciliação": política e História em Joaquim Nabuco

O artigo se propõe a discutir as complexas mediações entre política, memória e escrita da história, tomando como referência o recente livro de Izabel Andrade Marson, Política, história e método em Joaquim Nabuco: tessituras da revolução e da escravidão. Fundamentando-se, igualmente, em considerações de Maria Stella Bresciani e Carlos Alberto Vesentini, o texto procura problematizar procedimentos concernentes ao ofício de historiar.

Epidemiological and ecological aspects related to malaria in the area of influence of the lake at Porto Primavera dam, in western São Paulo State, Brazil

A study was carried out in the area of influence of the Porto Primavera Hydroelectric Power Station, in western São Paulo State, to investigate ecological and epidemiological aspects of malaria in the area and monitor the profile of the anopheline populations following the environmental changes brought about by the construction of the lake. Mosquitoes captured were analyzed by standardized indicator species analysis (ISA) before and during different flooding phases (253 m and 257 m elevations). The local human population was studied by means of parasitological (thin/thick blood smears), molecular (PCR) and serological tests. Serological tests consisted of Enzyme Linked Immunosorbent Assay (ELISA) with synthetic peptides of the circumsporozoite protein (CSP) from classic Plasmodium vivax, P. vivax variants (VK247 and "vivax-like"), P. malariae and P. falciparum and Indirect Immunofluorescence Assay (IFA) with asexual forms of P. vivax, P. malariae and P. falciparum. The results of the entomological survey indicated that, although the Anopheles darlingi population increased after the flooding, the population density remained very low. No malaria, parasite infection or DNA was detected in the inhabitants of the study area. However, there was a low frequency of antibodies against asexual forms and a significant prevalence of antibodies against P. vivax, P. vivax variants, P. falciparum and P. malariae; the presence of these antibodies may result from recent or less recent contact with human or simian Plasmodium (a parallel study in the same area revealed the existence of a sylvatic cycle). Nevertheless, these results suggest that, as in other places where malaria is present and potential vectors circulate, the local epidemiological conditions observed could potentially support the transmission of malaria in Porto Primavera Lake if infected individuals are introduced in sufficient numbers. Further studies are required to elucidate the phenomena described in this paper.

Natural antioxidant from yerba maté (Ilex paraguariensis St. Hil.) prevents hamburger peroxidation

The aim of this study was to evaluate whether yerba maté alcoholic extracts at very low concentrations (0.01 and 0.1%), prevent/retard lipid peroxidation in beef hamburgers without impairing sensory acceptability. For this TBARs and hexanal levels, fatty acid profile and cholesterol oxides were evaluated as oxidation parameters in beef hamburgers during 90 days' storage. The addition of 0.01% yerba maté ethanolic extracts proved inefficient in restraining the lipid peroxidation while the addition of 0.1% resulted in efficient antioxidant activity. Sensory evaluation of hamburger containing 0.1% yerba maté ethanolic extracts showed good acceptability. Yerba maté ethanolic extracts could entirely or partially replace the phenolic synthetic antioxidants in beef hamburgers only when used at above legally allowed concentrations for antioxidant additives (0.01%).

Estudo clínico da aplicação de matriz inorgânica de osso associado a peptídeo sintético de adesão celular (MIO/P-15), PepGen P-15®, em lesões periodontais avançadas de cães

Os mecanismos biológicos desenvolvidos para aumentar a qualidade da regeneração óssea e da reparação tecidual de sítios periodontais específicos continuam a ser um desafio e têm sido complementado pela capacidade de adesão celular do colágeno do tipo I, promovida por um peptídeo sintético de adesão celular (P-15), associado a uma matriz inorgânica de osso (MIO) para formar MIO/P-15. O objetivo deste estudo foi avaliar a perda do nível clínico de inserção e a resposta da bolsa periodontal em dentes após 3 e 6 meses da aplicação de enxerto com MIO/P-15. Vinte e um cães do Hospital Veterinário da Universidade de São Paulo foram anestesiados para realização de tratamento periodontal e 132 faces dentais com perda de nível clínico de inserção foram tratadas, sendo que 36,4% (48 faces) receberam o peptídeo de adesão celular e 63,6% (84 faces) compuseram o grupo controle que recebeu tratamento convencional (retalho muco-gengival e aplainamento radicular). O procedimento foi documentado através de radiografia intra-oral e todas as sondagens de bolsas periodontais foram fotografadas. Depois de 3 e de 6 meses, os animais foram re-anestesiados a fim de se obter novas avaliações, radiografias, fotografias e sondagens periodontais. As 48 faces com perda de nível clínico de inserção que receberam material de enxertia apresentaram taxa de 40% de recuperação do nível clínico de inserção após 6 meses. O grupo controle de faces dentais não apresentou alteração do nível clínico de inserção. A face palatina foi a que apresentou melhor taxa de regeneração (40%) e os dentes caninos e molares mostraram as melhores respostas (57,14% e 65%, respectivamente). Não houve sinais de infecção pós-cirúrgica relacionadas à falta de higienização oral dos animais. Pode-se concluir que o MIO/P-15 auxilia na regeneração e re-aderência das estruturas periodontais, incluindo osso alveolar. Sua aplicação mostrou-se fácil e prática e a incidência de complicações pós-cirúrgicas foi baixa. Ainda assim, mais estudos e pesquisas são necessários para que se avalie a quantidade e a qualidade do osso e do ligamento periodontal formados.

Níveis de lisina digestível e zinco quelato sobre os parâmetros produtivos de poedeiras marrons

Objetivou-se avaliar a produção de ovos em galinhas Isa Brown alimentadas com dietas com diferentes níveis de lisina digestível e zinco quelato. Utilizaram-se 720 poedeiras marrons, em dois períodos de avaliação, de 24 a 36 e de 48 a 60 semanas de idade. As dietas foram avaliadas em delineamento inteiramente casualizado, em esquema fatorial 5 × 3, composto de 5 níveis de lisina digestível (0,482; 0,527; 0,582; 0,644 e 0,732%) e 3 de zinco quelato (20, 40 e 80 ppm), de modo que cada combinação foi testada em 6 repetições de 8 aves por unidade experimental. Na fase de 24 a 36 semanas de idade, houve influência da interação de lisina digestível e zinco no consumo médio diário de ração e na porcentagem de postura. Na fase de 48 a 60 semanas, a interação foi evidenciada somente no consumo médio diário de ração. O aumento da concentração de lisina digestível favoreceu o consumo de ração em todos os níveis de zinco. Em ambas as fases, a menor concentração de zinco atende às necessidades de produção das aves. O valor médio estimado de lisina digestível ideal foi de 0,732% para a fase de 24 a 36 semanas e de 0,578% para a fase de 48 a 60 semanas de idade.

Electronic properties and hyperfine fields of nickel-related complexes in diamond

We carried out a first-principles investigation on the microscopic properties of nickel-related defect centers in diamond. Several configurations, involving substitutional and interstitial nickel impurities, have been considered either in isolated configurations or forming complexes with other defects, such as vacancies and boron and nitrogen dopants. The results, in terms of spin, symmetry, and hyperfine fields, were compared with the available experimental data on electrically active centers in synthetic diamond. Several microscopic models, previously proposed to explain those data, have been confirmed by this investigation, while some models could be discarded. We also provided insights into the microscopic structure of several of those centers.

Resprouting from roots in four Brazilian tree species

Previous studies pointed out that species richness and high density values within the Leguminosae in Brazilian forest fragments affected by fire could be due, at least partially, to the high incidence of root sprouting in this family. However, there are few Studies of the factors that induce root sprouting in woody plants after disturbance. We investigated the bud formation on root cuttings, and considered a man-made disturbance that isolates the root from the shoot apical dominance of three Leguminosae (Bauhinia forficata Link., Centrolobium tomentosum Guill. ex Benth, and Inga laurina (Sw.) Willd) and one Rutaceae (Esenbeckia febrifuga (St. Hit.) Juss. ex Mart.). All these species resprout frequently after fire. We also attempted to induce bud formation on root systems by removing the main trunk, girdling or sectioning the shallow lateral roots from forest tree species Esenbeckia febrifuga and Hymenaea courbaril L. We identified the origin of shoot primordia and their early development by fixing the samples in Karnovsky solution, dehydrating in ethyl alcohol series and embedding in plastic resin. Serial sections were cut on a rotary microtome and stained with toluidine blue O. Permanent slides were mounted in synthetic resin. We observed different modes of bud origin on root cuttings: close to the vascular cambium (C. tomentosum), from the callus (B. forficata and E febrifuga) and from the phloematic parenchyma proliferation (L laurina). Fragments of B. forficala root bark were also capable of forming reparative buds from healing phellogen formed in callus in the bark's inner side. In the attempt of bud induction on root systems, Hymenaea courbaril did not respond to any of the induction tests, probably because of plant age. However, Esenbeckia febrifuga roots formed suckers when the main trunk was removed or their roots were sectioned and isolated from the original plant. We experimentally demonstrated the ability of four tree species to resprout from roots after disturbance. Our results suggest that the release of apical dominance enables root resprouting in the studied species. Rev. Biol. Trop. 57 (3): 789-800. Epub 2009 September 30.

Identification of a Highly Antigenic Linear B Cell Epitope within Plasmodium vivax Apical Membrane Antigen 1 (AMA-1)

Apical membrane antigen 1 (AMA-1) is considered to be a major candidate antigen for a malaria vaccine. Previous immunoepidemiological studies of naturally acquired immunity to Plasmodium vivax AMA-1 (PvAMA-1) have shown a higher prevalence of specific antibodies to domain II (DII) of AMA-1. In the present study, we confirmed that specific antibody responses from naturally infected individuals were highly reactive to both full-length AMA-1 and DII. Also, we demonstrated a strong association between AMA-1 and DII IgG and IgG subclass responses. We analyzed the primary sequence of PvAMA-1 for B cell linear epitopes co-occurring with intrinsically unstructured/ disordered regions (IURs). The B cell epitope comprising the amino acid sequence 290-307 of PvAMA-1 (SASDQPTQYEEEMTDYQK), with the highest prediction scores, was identified in domain II and further selected for chemical synthesis and immunological testing. The antigenicity of the synthetic peptide was identified by serological analysis using sera from P. vivax-infected individuals who were knowingly reactive to the PvAMA-1 ectodomain only, domain II only, or reactive to both antigens. Although the synthetic peptide was recognized by all serum samples specific to domain II, serum with reactivity only to the full-length protein presented 58.3% positivity. Moreover, IgG reactivity against PvAMA-1 and domain II after depletion of specific synthetic peptide antibodies was reduced by 18% and 33% (P = 0.0001 for both), respectively. These results suggest that the linear epitope SASDQPTQYEEEMTDYQK is highly antigenic during natural human infections and is an important antigenic region of the domain II of PvAMA-1, suggesting its possible future use in pre-clinical studies.