Catabolism of Ap4A and Ap5A by rat brain synaptosomes

Adenosine 5',5'''-P1,P4-tetraphosphate (Ap4A) and adenosine 5',5'''-P1,P5-pentaphosphate (Ap5A) are stored in and released from rat brain synaptic terminals. In the present study we investigated the hydrolysis of dinucleotides (Ap4A and Ap5A) in synaptosomes from the cerebral cortex of adult rats. Ap4A and Ap5A, but not Ap3A, were hydrolyzed at pH 7.5 in the presence of 20 mM Tris/HCl, 2.0 mM MgCl2, 10 mM glucose and 225 mM sucrose at 37oC. The disappearance of the substrates measured by FPLC on a mono-Q HR column was both time and protein dependent. Since synaptosome integrity was at least 90% at the end of the assay, hydrolysis probably occurred by the action of an ecto-enzyme. Extracellular actions of adenine dinucleotides at central nervous system terminate due to the existence of ecto-nucleotidases which specifically cleave these dinucleotides. These enzymes in association with an ATP diphosphohydrolase and a 5'-nucleotidase are able to promote the complete hydrolysis of dinucleotides to adenosine in the synaptic cleft.

Development of a Glycocluster Adjuvant Mimicking Natural Yeast beta-(1,2)-Structures

Allergy is characterized by T helper (Th) 2-type immune response after encounter with an allergen leading to subsequent immunoglobulin (Ig) E-mediated hypersensitivity reaction and further allergic inflammation. Allergen-specific immunotherapy (SIT) balances the Th2-biased immunity towards Th1 and T regulatory responses. Adjuvants are used in allergen preparations to intensify and modify SIT. ��-(1,2)-oligomannoside constituents present in Candida albicans (C. albicans) cell wall possess Th1-type immunostimulatory properties. The aim of this thesis was to develop a ��-(1,2)-linked carbohydrate compound with known structure and anti-allergic properties to be applied as an adjuvant in SIT. First the immunostimulatory properties of various fungal extracts were studied. C. albicans appeared to be the most promising Th1-inducing extract, which led to the synthesis of various mono- or divalent oligomannosides designed on the basis of C. albicans. These carbohydrates did not induce strong cytokine production in human peripheral blood mononuclear cell (PBMC) cultures. In contrast to earlier reports using native oligosaccharides from C. albicans, synthetic ���-(1,2)-linked mannotetraose did not induce any tumor necrosis factor production in murine macrophages. Next, similarities with synthesized divalent mannosides and the antigenic epitopes of ��-(1,2)-linked C. albicans mannan were investigated. Two divalent compounds inhibited specific IgG antibodies binding to below 3 kDa hydrolyzed mannan down to the level of 30���50% showing similar antigenicity to C. albicans. Immunomodulatory properties of synthesized carbohydrate assemblies ranging from mono- to pentavalent were evaluated. A trivalent acetylated dimannose (TADM) induced interleukin-10 (IL-10) and interferon-�� responses. TADM also suppressed birch pollen induced IL-4 and IL-5 responses in allergen (Bet v) stimulated PBMCs of birch pollen allergic subjects. This suppression was stronger with TADM than with other used adjuvants, immunostimulatory oligonucleotides and monophosphoryl lipid A. In a murine model of asthma, the allergen induced inflammatory responses could also be suppressed by TADM on cytokine and antibody levels.

Screening for carbohydrate-binding proteins in extracts of Uruguayan plants

The presence of carbohydrate-binding proteins, namely lectins, ��-galactosidases and amylases, was determined in aqueous extracts of plants collected in Uruguay. Twenty-six extracts were prepared from 15 Uruguayan plants belonging to 12 Phanerogam families. Among them, 18 extracts caused hemagglutination (HAG) that was inhibited by mono- and disaccharides in 13 cases, indicating the presence of lectins. The other 8 extracts did not cause any HAG with the four systems used to detect HAG activity (rabbit and mouse red cells, trypsin-treated rabbit and mouse red cells). For the extracts prepared from Solanum commersonii, HAG activity and HAG inhibition were similar for those prepared from tubers, leaves and fruits, with the chitocompounds being responsible for all the inhibitions. Purification of the S. commersonii tuber lectin was carried out by affinity chromatography on asialofetuin-Sepharose, and SDS-PAGE under reducing conditions gave a single band of Mr of approximately 80 kDa. The monomer N-acetylglucosamine did not inhibit HAG induced by the purified lectin, but chitobiose inhibited HAG at 24 mM and chitotriose inhibited it at 1 mM. ��-Galactosidase activity was detected in leaves and stems of Cayaponia martiana, and in seeds from Datura ferox. Only traces of amylase activity were detected in some of the extracts analyzed. The present screening increases knowledge about the occurrence of carbohydrate-binding proteins present in regional plants.

There is no difference in hepatic fibrosis rates of patients infected with hepatitis C virus and those co-infected with HIV

Some studies have suggested that human immunodeficiency virus (HIV) infection modifies the natural history of hepatitis C virus (HCV) infection, accelerating the progression of fibrosis and the development of cirrhosis. Our objective was to evaluate the fibrosis progression rate (FPR) in HCV/HIV-co-infected patients, and to identify factors that may influence it. HCV-mono-infected and HCV/HIV-co-infected patients with a known date of HCV infection (transfusion or injection drug use) and a liver biopsy were included. The FPR was defined as the ratio between the fibrosis stage (Metavir score) and the estimated length of infection in years and the result was reported as fibrosis units per year. The factors studied were gender, age at infection, consumption of alcohol, aminotransferase levels, histological activity grade, HCV genotype and viral load, CD4 cell count, HIV viral load, and the use of antiretroviral therapy. Sixty-five HCV-infected (group 1) and 53 HCV/HIV-co-infected (group 2) patients were evaluated over a period of 19 months. The mean FPR of groups 1 and 2 was 0.086 �� 0.074 and 0.109 �� 0.098 fibrosis units per year, respectively (P = 0.276). There was a correlation between length of HCV infection and stage of fibrosis in both groups. The age at infection, the aspartate aminotransferase level (r = 0.36) and the inflammatory activity grade were correlated with the FPR (P < 0.001). No difference in FPR was found between HCV-mono-infected and HCV/HIV-co-infected patients.

Modulation of ROS production in human leukocytes by ganglioside micelles

Recent studies have reported that exogenous gangliosides, the sialic acid-containing glycosphingolipids, are able to modulate many cellular functions. We examined the effect of micelles of mono- and trisialoganglioside GM1 and GT1b on the production of reactive oxygen species by stimulated human polymorphonuclear neutrophils using different spectroscopic methods. The results indicated that exogenous gangliosides did not influence extracellular superoxide anion (O2.-) generation by polymorphonuclear neutrophils activated by receptor-dependent formyl-methionyl-leucyl-phenylalanine. However, when neutrophils were stimulated by receptor-bypassing phorbol 12-myristate 13-acetate (PMA), gangliosides above their critical micellar concentrations prolonged the lag time preceding the production in a concentration-dependent way, without affecting total extracellular O2.- generation detected by superoxide dismutase-inhibitable cytochrome c reduction. The effect of ganglioside GT1b (100 ��M) on the increase in lag time was shown to be significant by means of both superoxide dismutase-inhibitable cytochrome c reduction assay and electron paramagnetic resonance spectroscopy (P < 0.0001 and P < 0.005, respectively). The observed phenomena can be attributed to the ability of ganglioside micelles attached to the cell surface to slow down PMA uptake, thus increasing the diffusion barrier and consequently delaying membrane events responsible for PMA-stimulated O2.- production.

Skheda��rion quaternionis meletematum, e venerando et augusto sapientiae archivo erutorum

Invokaatio: Sun to Theo mono athanato.

Produ����o de anticorpos para cafe��na e seu derivado cafeinidina

S��o apresentados dados sobre a conjuga����o de cafe��na e seu derivado cafeinidina com albumina de soro bovino e sua utiliza����o para a produ����o de anticorpos. Galinhas poedeiras foram imunizadas e as globulinas extra��das das gemas dos ovos. Por ensaios de imunoprecipita����o pode-se verificar que ambos anticorpos reagiram com seus respectivos ant��genos, cafe��na e cafeinidina. Tamb��m verificou-se que a posi����o do radical metil em mono e dimetilxantinas era importante para o reconhecimento ant��geno-anticorpo. Metila����o na posi����o N-3 pareceu ser determinante para o reconhecimento pelo anticorpo produzido para o conjugado cafeinidina-BSA. Por outro lado, metila����o na posi����o N-7 foi importante para o conjugado cafe��na-BSA. Discute-se as vantagens de um anticorpo sobre o outro e a possibilidade de seu emprego em testes imunol��gicos para determina����o de alcal��ides pur��nicos totais em material vegetal e seus derivados aliment��cios.

MISTURAS DE FARINHA DE AVEIA E AMIDO DE MILHO COM ALTO TEOR DE AMILOPECTINA PARA PRODU����O DE "SNACKS"

O potencial de uso do amido modificado com alto teor de amilopectina combinado �� farinha de aveia para produ����o de "snacks" extrusados foi investigado. O processamento foi executado em extrusor mono-rosca, de acordo com um delienamento fatorial (2(5)) incompleto, com 3 repeti����es no ponto central. As vari��veis independentes controladas foram: umidade da mat��ria-prima, temperatura de extrus��o, rota����o do parafuso, di��metro da matriz e teor de amido modificado. Como respostas, avaliou-se o volume espec��fico, a dureza e a fraturabilidade. A partir da modelagem explorat��ria foram definidas as vari��veis significativas e novos deslocamentos na ��rea experimental, at�� se atingir o ponto ��timo para produ����o de "snacks". A melhor combina����o de vari��veis encontrada, para obter um produto com boas propriedades de expans��o e de textura, foi: 17% de umidade de mat��ria-prima, 183��C de temperatura de extrus��o, 100rpm de rota����o do parafuso, 4mm de di��metro da matriz e 30% de amido modificado. O produto obtido nessas condi����es apresentou 7,2mL/g de volume espec��fico, 5,41N de dureza e 2,02N de fraturabilidade, assemelhando-se, por essas caracter��sticas, aos produtos comerciais de milho.

Par��metros de estrus��o para produ����o de "snacks" de farinha de car�� (Dioscorea alata)

Farinha de car�� (Dioscorea alata) foi processada em extrusor mono-rosca, para a manufatura de "snacks". Foi empregada a Metodologia de Superf��cie de Resposta para avaliar os efeitos da umidade (16, 20 e 24%), temperatura (120, 150 e 180&ordm;C) e di��metro da matriz (3, 4 e 5mm) nas caracter��sticas dos extrusados. A temperatura foi a vari��vel mais importante, influenciando todas as propriedades estudadas. O volume espec��fico e o comprimento espec��fico aumentaram quando a temperatura aumentou e a umidade e o di��metro da matriz diminu��ram, enquanto, ao mesmo tempo, fraturabilidade e dureza diminu��ram. A expans��o diminuiu, quando a temperatura aumentou de 120 para 180&ordm;C. Foram selecionadas duas condi����es experimentais que possibilitavam obter "snacks" com propriedades desej��veis (alto volume espec��fico e baixa dureza e fraturabilidade) e os produtos foram avaliados por equipes sensoriais n��o treinadas. Estas apontaram que o melhor produto foi aquele extrusado com um teor de umidade de 17%, a 170&ordm;C, com uma matriz de 4mm de abertura. Este produto obteve um ��ndice de aceitabilidade de 80%, quando avaliado por 140 consumidores.

Perfil de ��cidos graxos trans de ��leo e gordura hidrogenada de soja no processo de fritura

O objetivo desse estudo foi avaliar as altera����es dos ��cidos graxos e a forma����o de is��meros trans, durante o aquecimento de ��leo de soja (OS) e gordura parcialmente hidrogenada de soja (GPHS) no processo de fritura de batata por 100 horas com reposi����o lip��dica. O perfil de ��cidos graxos foi avaliado atrav��s de cromatografia gasosa em coluna capilar de 100m. Os ��cidos graxos monoinsaturados trans foram os predominantes entre os is��meros trans. A partir de 10 horas de fritura, o OS formou 2,1% de is��meros mono trans e ao final de 50 horas este valor passou a 14,3% contra uma diminui����o do total de ��cidos graxos poliinsaturados, que passou de 59,9% antes do processamento para 32,6% ap��s 50h de fritura. Entretanto, a GPHS apresentou 20,2% de ��cidos graxos mono trans antes de ser submetida �� fritura e ap��s 50 horas apresentou uma concentra����o de 28%. Houve tamb��m, uma diminui����o do total de ��cidos graxos essenciais s��ries ��mega6 e ��mega3, de 12,8% para 7,3% no mesmo per��odo. Os resultados obtidos revelaram que is��meros trans s��o formados no ��leo e na gordura durante o processo de fritura, sendo que a forma����o de is��meros trans, ocorreu em menor propor����o na GPHS, confirmando a sua maior estabilidade em rela����o ao OS. Estes resultados indicam a import��ncia de se identificar os ��cidos graxos trans nos ��leos e gorduras ulizadas em processos de fritura.

Efeitos de par��metros de extrus��o nas propriedades f��sicas de produtos expandidos de inhame

Neste trabalho, estudou-se o efeito de par��metros de extrus��o sobre o ��ndice de expans��o (IE), volume espec��fico (VE), ��ndice de absor����o de ��gua (IAA) e ��ndice de solubilidade em ��gua (ISA) de extrusados de inhame. O processamento foi executado em extrusor mono rosca. Para analisar o efeito combinado das vari��veis independentes nas caracter��sticas tecnol��gicas dos extrusados de farinha de inhame, utilizou-se o delineamento 'central composto rotacional' para tr��s fatores. O desenho experimental foi elaborado para verificar o efeito de tr��s n��veis de temperatura na ��ltima zona de extrus��o (100, 115 e 130��C), rota����o da rosca (163, 204 e 245 rpm) e umidade das farinhas (12, 15 e 18%). Os resultados obtidos mostraram que a umidade e a temperatura influenciaram os par��metros de expans��o (IE e VE). O ��ndice de solubilidade em ��gua (ISA) foi dependente dos tr��s par��metros do processo. Temperatura elevada e alta rota����o da rosca promoveram maiores valores de ISA. Nas condi����es estudadas, os par��metros de extrus��o n��o influenciaram o ��ndice de absor����o de ��gua (IAA).

Hidr��lise enzim��tica do ��leo de pescado

O ��leo de pescado tem sido alvo de v��rias pesquisas em fun����o dos benef��cios nutricionais dos ��cidos graxos poliinsaturados. Esse fato pode ser comprovado pelos estudos epidemiol��gicos que relacionam a baixa incid��ncia de doen��as cardiovasculares com o consumo de ��cidos graxos n-3 (EPA-eicosapentaen��ico e DHA-docosahexaen��ico) provenientes de peixes marinhos. A obten����o de ��cidos graxos poliinsaturados n-3 pode ser realizada por hidr��lise enzim��tica. A hidr��lise enzim��tica de ��leos e gorduras, ou lip��lise, �� bem conhecida e vem sendo estudada para produzir ��cidos graxos e modificar as gorduras por esterifica����o, transesterifica����o e interesterifica����o. O objetivo deste trabalho foi a obten����o de ��cidos graxos poliinsaturados por hidr��lise enzim��tica do ��leo de pescado industrial. A hidr��lise de 1262,81 ��moles de ��leo de pescado com lipase pancre��tica porcina (concentra����o de extrato enzim��tico de 7,647 mg.mL-1), 60 minutos, 38 &deg;C, pH 8, tamp��o NH4Cl-NH4OH. Os produtos da hidr��lise foram separados por cromatografia em coluna e caracterizados por cromatografia em camada delgada (TLC) e gasosa (GLC). A enzima apresentou uma atividade espec��fica de 10,14 &plusmn; 0,15 UE.mg de prote��nas-1 e com 60 minutos de rea����o se obteve 44,45% de hidr��lise com 1865,76 &plusmn; 41,15 ��mols de ��cidos graxos. Foram identificados ��cidos graxos livres, mono-acilglicer��is, di-acilglicer��is e tri-acilglicer��is. Na fra����o dos tri-acilglicer��is verificou-se um aumento de 46,14% e 40,23% de ��cido araquid��nico e eicosapentaen��ico (EPA) respectivamente, enquanto que na fra����o monoacilglicerol um acr��scimo de 96,96% e 52,55% de DPA e DHA.

Produ����o de biscoitos extrusados de polvilho azedo com fibras: efeito de par��metros operacionais sobre as propriedades f��sicas

Neste trabalho buscou-se avaliar o efeito de par��metros operacionais do processo de extrus��o no desenvolvimento de biscoitos de polvilho com fibras, utilizando como mat��rias-primas o polvilho azedo e o farelo de mandioca. O processamento foi realizado em um extrusor mono-rosca, sendo considerados par��metros vari��veis: temperatura na 3�� zona de extrus��o, umidade e porcentagem de fibras na mistura. Para analisar o efeito combinado das vari��veis independentes nas caracter��sticas tecnol��gicas dos extrusados, utilizou-se o delineamento 'central composto rotacional' para tr��s fatores. Os resultados obtidos mostraram efeitos significativos da umidade e porcentagem de fibras sobre o volume espec��fico, sendo que a temperatura afetou os ��ndices de solubilidade e absor����o de ��gua dos produtos extrusados. Condi����es de baixa temperatura (65 ��C), baixa umidade (12%) e baixo teor de fibras (<4%), nas condi����es de processo utilizadas, produzem biscoitos com boas caracter��sticas tecnol��gicas.

Chemical sanitizers to control biofilms formed by two Pseudomonas species on stainless steel surface

The biofilm formation of Pseudomonas aeruginosa and Pseudomonas fluorescens on AISI 304 stainless steel in the presence of reconstituted skim milk under different temperatures was conducted, and the potential of three chemical sanitizers in removing the mono-species biofilms formed was compared. Pseudomonas aeruginosa cultivated in skim milk at 28 ��C presented better growth rate (10.4 log CFU.mL-1) when compared with 3.7 and 4.2 log CFU.mL-1 for P. aeruginosa and P. fluorescens cultivated at 7 ��C, respectively. Pseudomonas aeruginosa formed biofilm when cultivated at 28 ��C. However, only the adhesion of P. aeruginosa and P. fluorescens was observed when incubated at 7 ��C. The sodium dichloroisocyanurate was the most efficient sanitizer in the reduction of the adhered P. aeruginosa cells at 7 and 28 ��C and those on the biofilm, respectively. The hydrogen peroxide was more effective in the reduction of adhered cells of P. fluorescens at 7 ��C.

Purification, partial characterization and antimicrobial activity of Lectin from Chenopodium Quinoa seeds

Abstract A novel lectin was isolated from the seeds of Chenopodium quinoa. To achieve this end, the crude extract from the quinoa was submitted to two purification steps, Sephadex G50 and Mono Q. The hemagglutinating activity showed that this lectin agglutinates human erythrocytes. Its activity is inhibited by glucose and mannose, and remained stable under a wide range of pH levels and temperatures. The quinoa lectin was found to be a heterodimeric lectin of approximately 60 kDa, consisting of two subunits of approximately 25 kDa and 35 kDa. This lectin had its antimicrobial activity tested against several bacteria strains and effectively inhibited three strains. These strains were all Gram-negative, making this lectin a promising antimicrobial tool.