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Search Results: 1 - 10 of 391362 matches for " Raúl Jorge Hernan Castro Gómez "
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Production, characterization and technological properties of biopolymer produced by Agrobacterium radiobacter k84 Produ o, caracteriza o e propriedades tecnológicas de um biopolímero produzido por Agrobacterium radiobacter k84
Caroline Maria Calliari,Marciane Magnani,Raúl Jorge Hernan Castro Gómez
Semina : Ciências Agrárias , 2011,
Abstract: In this study, a biopolymer composed of carbohydrates (35%), protein (15%) and minerals (40%) was obtained through fermentation using sugar cane molasses as the sole carbon source for Agrobacterium radiobacter k84. The process yield was 10 gL-1 of biopolymer, which showed high solubility in water, neutral pH in aqueous solution and low water activity (0.52). The analysis in Scanning Electron Microscopy revealed microstructure characteristic of an amorphous solid, with particles of irregular shapes and sizes. In the evaluation of technological properties, the biopolymer showed formation of viscous solutions at room temperature from concentration of 0.5% in aqueous solution, gelling activity in solution at 2%, emulsifying (56.11±1.39%) and stabilizing activity (98.02±0.78%). The results suggest that the biopolymer from Agrobacterium radiobacter k84 is a promising candidate for industrial use. No presente estudo, utilizando mela o de cana-de-a úcar como única fonte de carbono para Agrobacterium radiobacter k84 foi obtido, em processo fermentativo, um biopolímero composto por carboidratos (35%), proteínas (15%) e minerais (40%). O rendimento do processo foi de 10 g.L-1 do biopolímero que apresentou elevada solubilidade em água, pH neutro em solu o aquosa e baixa atividade de água (0.52). As análises em Microscopia Eletr nica de Varredura revelaram microestrutura característica de um sólido amorfo, com partículas de formas irregulares e tamanhos variáveis. Na avalia o das propriedades tecnológicas, o biopolímero mostrou viscosidade à temperatura ambiente a partir da concentra o 0.5% em solu o aquosa, atividade geleificante em solu o a 2%, atividade emulsificante (56.11±0.78%) e estabilizante (98.02±1.39%). Os resultados sugerem o biopolímero de Agrobacterium radiobacter k84 como um candidato promissor para uso industrial.
Bacillus thuringiensis: general characteristics and fermentation Bacillus thuringiensis: características gerais e fermenta o
Elisangela Andrade Angelo,Gislayne Trindade Vilas-B?as,Raúl Jorge Hernan Castro-Gómez
Semina : Ciências Agrárias , 2010,
Abstract: The insect control is carried out mostly by chemical products, whose cumulative effects cause serious losses to environmental and human health, highlighting rapid selection of resistant insects. Biological control by entomopathogenic bacteria is an efficient alternative, mainly due to high specificity, absence of resistance in the target insects and low environment residual effect. Bacillus thuringiensis is a Gram-positive spore-forming bacterium that produces a parasporal crystal protein toxic for many insect species. Despite the widespread use of B. thuringiensis based products in biological control of insects, there are little studies about its multiplication, sporulation and crystal production, as so many trade secrets information. This revision was aimed at gathering general information about B. thuringiensis, as well as its production in culture media. O controle de insetos é realizado, em sua maioria, por produtos químicos; cujos efeitos cumulativos ocasionam grandes prejuízos ambientais e à saúde humana, destacando-se ainda a rápida sele o de insetos resistentes. O controle biológico por entomopatógenos é uma alternativa eficiente, principalmente devido a sua alta especificidade, ausência de resistência nos insetos alvos e baixo efeito residual no ambiente. Bacillus thuringiensis é uma bactéria Gram-positiva esporulante, produtora de cristais protéicos com atividade inseticida. Apesar do amplo uso B. thuringiensis no controle biológico, há poucos trabalhos publicados quanto a sua multiplica o, esporula o e produ o de cristais, visto que muitas informa es s o segredos industriais. Esta revis o teve por objetivo reunir informa es gerais sobre B. thuringiensis, bem como quanto sua produ o em meios de cultivo.
Antimicrobial activity of Lactobacillus and Bifidobacterium strains against pathogenic microorganisms “in vitro” Atividade antimicrobiana de Lactobacillus e Bifodobacterium frente a microrganismos patogênicos “in vitro”
Giselle Nobre Costa,Helio Hiroshi Suguimoto,Lucia Helena da Silva Miglioranza,Raúl Jorge Hernan Castro Gómez
Semina : Ciências Agrárias , 2012,
Abstract: Lactobacilli and bifidobacteria have a long history of safe use in foods. These bacteria have biotechnological characteristics of interest such as the inhibition of pathogens. In this work, two lactobacilli strain and a bifidobacterium strain isolated from human gut were evaluated concerning to their ability to inhibit pathogenic microorganisms in foods by diffusion agar tests. Moreover, we assessed the metabolites produced in culture broth under static and shaking growth to simulate anaerobiosis and aerobiosis conditions, respectively. L. acidophilus LA5, L. plantarum DCTA 8420 and B. lactis DCTA 8724 showed ability to inhibit S. aureus FRI 196, strains producer toxins A and D, as well as B. cereus ATCC 25923, E. coli ATCC 25922 and S. Enteritidis, whose inhibition halos reached, on average, 24 mm in diameter. In the agar diffusion method with concentrated culture medium, it was possible to observe the effect of oxygen on the production of toxic substances. This result showed that cultivation of Lactobacillus under aerobic conditions seems to exert greater inhibitory effect, whereas for Bifidobacterium strain the effect was the opposite. Lactobacilos e bifidobactérias apresentam um longo histórico de uso seguro em alimentos, além de apresentarem características de interesse biotecnológico como a inibi o de patógenos. Neste trabalho duas linhagens de lactobacilos e uma de bifidobactéria, isoladas do intestino humano, foram avaliadas em testes de difus o em ágar, quanto à capacidade de inibi o de microrganismos patogênicos de ocorrência comuns em toxinfec es alimentares. Adicionalmente, foram avaliados os metabólitos produzidos em caldo de cultivo estático e em agita o para simular condi es de anaerobiose a aerobiose, respectivamente. As três bactérias, L. acidophilus LA5, L. plantarum DCTA 8420 e B. lactis DCTA 8724 apresentaram capacidade de inibi o para S. aureus FRI 196 linhagem produtora de toxinas A e D, assim como para B. cereus ATCC 25923, E. coli ATCC 25922 e S. Enteritidis, cujos halos de inibi o apresentaram em média 24 mm de diametro. No método de difus o em ágar com meio de cultivo concentrado, foi possível observar o efeito do oxigênio sobre a produ o de substancias tóxicas aos microrganismos indicadores, evidenciando que Lactobacillus cultivados em aerobiose, parece produzir metabólitos com maior efeito inibitório, enquanto que, para a linhagem de Bifidobacterium, o efeito foi oposto.
Avalia??o da mutagenicidade e antimutagenicidade de um biopolímero extraído do microorganismo Agrobacterium radiobacter em camundongos Swiss
Primo, Milka Selestina;Calliari, Caroline Maria;Castro-Gómez, Raúl Jorge Hernan;Mauro, Mariana de Oliveira;Mantovani, Mário Sérgio;Oliveira, Rodrigo Juliano;
Revista Brasileira de Farmacognosia , 2010, DOI: 10.1590/S0102-695X2010000300009
Abstract: this study evaluated the mutagenic and ant mutagenic action of a biopolymer of glucose extracted from agrobacterium radiobacter (biopolymer of agrobacterium radiobacter). the experiment was conducted with swiss male mice divided into eight groups. treatment with the biopolymer was performed in a single dose by gavage at a dose of concomitant phosphate buffer groups in the evaluation of mutagenicity, or the agent of inducing dna damage, cyclophosphamide, the concentration of 50 mg/kg (body weight --b.w.), in groups of assessment ant mutagenic. we used the micronucleus test in peripheral blood. the blood sample was held 24 and 48 h after application of the test substances. statistical analysis showed that the biopolymer has no mutagenic activity and it is effective in preventing damage to dna. the percentages of damage reduction in groups of ant mutagenic were 83.9%, 89.1% and 103.1% in 24 h and 101.24%, 98.14% and 120.64% at doses of 48 to 75, 150 and 300 mg/kg (b.w.) respectively. the high percentage of damage reduction associated with the absence of mutagenic effects indicates the possibility of biopolymer chemoprotection action. it can also be considered a functional food candidate to be used as co-adjuvant chemotherapy to prevent side effects.
Chemical and microbiological evaluation of ensiled sugar cane with different additives
Bravo-Martins, Claudia Eugênia Castro;Carneiro, Heloisa;Castro-Gómez, Raúl Jorge Hernán;Figueiredo, Henrique César Pereira;Schwan, Rosane Freitas;
Brazilian Journal of Microbiology , 2006, DOI: 10.1590/S1517-83822006000400018
Abstract: sugar cane silage has a potential for animal feeding, but uncontrolled growth of undesirable microorganisms may cause nutritional losses and affect the animal productivity and health. the objective of this work was to evaluate the microbiological quality and chemical composition of ensiled sugar cane with and without nutritional additives after 30 days of fermentation. yeasts, filamentous fungi and distinct groups of bacteria were enumerated by plate count methods and the chemical analyzes comprised dry matter, crude protein, fiber content, lignin, and ph. facultative aerobic bacteria and filamentous fungi were not detected during the fermentative process in any of the treatments. the number of yeasts in five varieties of sugar cane silage without additives was about 6.55 log cfu g-1 of silage, and with 1% ammonium sulfate and 1% urea were about 5.86 and 5.50 log cfu g-1 of silage, respectively. the lactic acid bacteria (lab) count without additive was about 8.62 log cfu g-1 of silage, and with 1% ammonium sulfate and 1% urea the count was about 6.40 and 6.54 log cfu g-1 of silage, respectively. the average percent of dry material in the three treatments was 20.76%. the addition of ammonium sulphate and urea has decreased the microbial load after 30 days but it has increased the total crude protein concentration. additives also affected neutral detergent fiber, acid detergent fiber and lignin content in all five varieties of sugar cane silage.
Antimicrobial activity of Lactobacillus acidophilus against foodborne pathogens/ Atividade antimicrobiana de Lactobacillus acidophilus, contra microrganismos patogênicos veiculados por alimentos
Valéria Garcia Pereira,Raul Jorge Hernan Castro Gómez
Semina : Ciências Agrárias , 2007,
Abstract: The antimicrobial activity of a commercial probiotic culture, Lactobacillus acidophilus (La5), was tested against two foodborne pathogens, Escherichia coli and Staphylococcus aureus. The antagonistic effect of the probiotic culture in vitro was performed by applying both Multilayer Agar Plate and Agar Well Diffusion methods. The results indicated that the inhibitory substance present on 72 hours culture broth supernatant was extracellular and diffusible. The incubation period of the lactic acid bacteria on MRS Broth, at 37oC in aerobic conditions, for the highest lactic acid production (1,08 g/%) was 72 hours, which gave a minimum pH value of the supernatant (3,90) and the best inhibition results by the Well Diffusion Agar Assay, showing inhibition zone diameters of 14,75mm and 15,0mm for E. coli and S. aureus, respectively. The inhibitor compound was not sensitive to proteolytic enzyme and freezing, but was totally inactivated when the supernatant was neutralized with NaOH 1 N solution. The results suggest that the inhibitory activity was due to the lactic acid concentration and the low pH of the probiotic culture broth. Foi avaliada a atividade antimicrobiana de uma cultura probiótica comercial, o Lactobacillus acidophilus La5, frente ao crescimento de dois microrganismos patogênicos veiculados por alimentos, Escherichia coli e Staphylococcus aureus. O antagonismo da cultura probiótica in vitro foi avaliado utilizando tanto a Metodologia de Multicamadas quanto a de Difus o em ágar. Os resultados demonstraram que a substancia inibidora presente no sobrenadante é extracelular e difusível. O período de incuba o da bactéria lática em caldo MRS, a 37oC em condi es de aerobiose, onde se obteve a maior produ o de ácido lático (1,08 g/%) foi 72 horas, o qual demonstrou o menor valor de pH do sobrenadante (3,90), e os melhores resultados de inibi o pelo método de difus o em ágar, com halos de inibi o de 14,75mm e 15,0mm de diametro para E. coli e S. aureus, respectivamente. O composto inibidor n o foi sensível à a o de enzimas proteolíticas e ao congelamento, mas foi totalmente inativado quando o sobrenadante foi neutralizado com solu o de NaOH 1N. Os resultados obtidos sugerem que atividade inibidora observada foi decorrente da concentra o de ácido lático e do baixo pH do meio de cultivo do microrganismo probiótico.
Beta-glucana from Saccharomyces cerevisiae: constitution, bioactivity and obtaining / Beta-glucana de Saccharomyces cerevisiae: constitui o, bioatividade e obten o
Marciane Magnani,Raul Jorge Hernan Castro-Gómez
Semina : Ciências Agrárias , 2008,
Abstract: b-glucans are polysaccharides that constitute the structure of the cell wall of yeast, fungi and some cereals, which differs each other by the linkages between glucose units. An important source of these polymers is the Saccharomyces cerevisiae cell wall, which is a yeast widely used in industrial processes of fermentation. The b-glucan is considered to be a modifier of biological response due to its immunomodulator potential. When it is recognized by specific cellular receptors, have the ability to enhance the host’s immune response. Other beneficial effects such as anticarcinogenic, antimutagenic, hypocholesterolemic and blood sugar reduction have also been related to the b-glucan. The aim of this literature review was expand scientific knowledge about the constitution and bioactivity of b-glucan, including its recognition by the immune system, as well as its obtaining from S. cerevisiae cell wall. b-glucanas s o polissacarídeos constituintes estruturais da parede celular de leveduras, fungos e alguns cereais, que se diferenciam pelo tipo de liga o presente entre as unidades de glicose. Uma importante fonte destes polissacarídeos é a parede celular de Saccharomyces cerevisiae, uma levedura amplamente empregada em processos industriais de fermenta o. A b-glucana é considerada um modificador da resposta biológica devido ao seu potencial imunomodulador, pois ao ser reconhecida por receptores celulares específicos tem habilidade de real ar a resposta imune do hospedeiro. Outros efeitos benéficos como anticarcinogênico, antimutagênico, hipocolesterolêmico e hipoglicêmico também têm sido relacionados à b-glucana Esta revis o de literatura teve por objetivo agregar conhecimentos científicos sobre a constitui o e bioatividade da b glucana, incluindo seu reconhecimento pelo sistema imune, bem como, a obten o a partir da parede celular de S. cerevisiae.
Chilean crude extract of Ruta graveolens generates vasodilatation in rat aorta at subtoxic cellular concentrations  [PDF]
Ignacio Jofré Fernández, Patricia Navarrete Gómez, Jorge Parodi, Fernando Romero Mejía, Raúl Salvatici Salazar
Advances in Bioscience and Biotechnology (ABB) , 2013, DOI: 10.4236/abb.2013.41005
Abstract:

In Chile elevated percentage of population have cardiovascular diseases, 70% of this populations is a hypertensive peoples. The Ruta graveolens (Ruta) is a medicinal plant used in different parts of the world with different therapeutics properties like dermatologic as far as anti-helmintic properties. We analyzed the vascular action measuring the tension to identify vasodilator effect of Ruta extract in norm-tense rat’s aorta incubated and measured in isolated organ bath, and evaluating the toxicity effect in CRL-1730 cell line, through enzymatic assay (MTT), confocal microscopy (propidium iodide stain) and flow cytometry (TUNEL assay), including extracellular reactive oxygen species (ROS) production through luminescence assay. The results show with DE50 29 ± 0.1 μg/mL evidenced vasodilatation, partially endothelium-depend. The cytotoxicity showed with DE50 304.6 ± 2 μg/mL in enzymatic assay (MTT) while evidenced membrane permeability in high concentrations (1500 μg/mL), DNA fragmentation in absence of oxidative stress in only observed when high concentrations of Ruta are used over the cell culture. The vasodilatation activity is executed in subtoxic concentration and partially endothelium-depend without permeability effect in the membrane and deterioration of the cells viability suggesting a complex effect of Ruta preparation in the regulation of vascular tone.

Complicaciones neurológicas en pacientes con linfomas
Gómez Viera,Nelson; Monteagudo Torres,Marisol; de Castro Arenas,Raúl; Ruiz García,Dania;
Revista Cubana de Medicina , 2000,
Abstract: a prospective and descriptive study was carried out in 270 patients diagnosed of lymphoma, admitted in hematology service of "hermanos ameijeiras" clinical surgical hospital in havana city, cuba, from march 1, 1996 to december 31, 1998, to assess neurologic complications. 26 patients presenting with neurologic complications were detected. from 188 sick persons with non-hodgkin's lymphoma, 12,2 % had neurologic manifestations. in these patients, leptomeninges infiltration was the more frequent neurologic complication. in 82 patients with hodgkin's disease, only 3,6 % had neurologic alteration and herpes zoster infection was the commonest one. we found higher percent of patients with syndromes attributable to spinal cord compression and to craneal pars disturbance, headache was commonest and motor deficit the more frequent one. it was confirmed that patients carriers of high grade malinancy non-hodgkin' s lymphoma, had the great percentage of neurologic complications (28,7 %), and average time between diagnosis of lymphoma and that of neurologic complications was shorter in these patients was (5,5 months). survival after diagnosis of neurologic manifestations in most patients was under l year. in 14 patients deceaced, neurologic complication was main direct cause of death
Complicaciones neurológicas en pacientes con linfomas
Nelson Gómez Viera,Marisol Monteagudo Torres,Raúl de Castro Arenas,Dania Ruiz García
Revista Cubana de Medicina , 2000,
Abstract: Se realizó un estudio descriptivo prospectivo en 270 pacientes con diagnóstico de linfoma ingresados en el Servicio de Hematología del Hospital Clinicoquirúrgico "Hermanos Ameijeiras" de Ciudad de La Habana, Cuba, en el período comprendido del 1ro de marzo de 1996 al 31 de diciembre de 1998, para conocer las complicaciones neurológicas. Se detectaron 26 pacientes con complicaciones neurológicas. De 188 enfermos con linfomas no-Hodgkin, el 12,2 % presentó manifestaciones neurológicas. En estos pacientes, la infiltración leptomeníngea fue la complicación neurológica más frecuente. En los 82 pacientes con enfermedad de Hodgkin, solamente 3,6 % tuvieron alteraciones neurológicas y la infección por Herpes zoster fue la más común. Se observó el mayor porcentaje de pacientes con síntomas y signos atribuibles a compresión de la médula espinal y a la alteración de pares craneales, la cefalea como el síntoma más común y el déficit motor, el signo más frecuente. Se comprobó que los pacientes con linfoma no Hodgkin de alto grado de malignidad presentaron el mayor porcentaje de complicaciones neurológicas (28,7 %) y el tiempo promedio entre el diagnóstico del linfoma y el diagnóstico de la complicación neurológica fue menor en estos enfermos (5,5 meses). El tiempo de supervivencia después del diagnóstico de las manifestaciones neurológicas en la mayoría de los pacientes fue inferior a un a o. De los 14 pacientes fallecidos, la complicación neurológica fue la principal causa directa de la muerte A prospective and descriptive study was carried out in 270 patients diagnosed of lymphoma, admitted in Hematology Service of "Hermanos Ameijeiras" Clinical Surgical Hospital in Havana City, Cuba, from March 1, 1996 to December 31, 1998, to assess neurologic complications. 26 patients presenting with neurologic complications were detected. From 188 sick persons with non-Hodgkin's lymphoma, 12,2 % had neurologic manifestations. In these patients, leptomeninges infiltration was the more frequent neurologic complication. In 82 patients with Hodgkin's disease, only 3,6 % had neurologic alteration and Herpes zoster infection was the commonest one. We found higher percent of patients with syndromes attributable to spinal cord compression and to craneal pars disturbance, headache was commonest and motor deficit the more frequent one. It was confirmed that patients carriers of high grade malinancy non-Hodgkin' s lymphoma, had the great percentage of neurologic complications (28,7 %), and average time between diagnosis of lymphoma and that of neurologic complications was shorter in the
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