ABSTRACT
ABSTRACT Freshwater algae are rich sources of structurally biologically active metabolites, such as fatty acids, steroids, carotenoids and polysaccharides. Among these metabolites, lectins stand out. Lectins are proteins or glycoproteins of non-immune origin which bind to carbohydrates or glycoconjugates, without changing ligand structure. Many studies have reported on the use of Spirogyra spp. as effective bioindicators of heavy metals; however, reports on Spirogyra molecular bioprospecting are quite limited. Therefore, this study aimed to detect, isolate, purify and characterize a lectin present in the freshwater green algae Spirogyra. Presence of the lectin protein in the extract was detected by hemagglutination assays. Subsequently, the protein extract was subjected to a sugar inhibition assay to identify the lectin-specific carbohydrate. Following this, the extract was applied to a guar gum column to afford the pure lectin. The lectin was inhibited by N-acetyl-glucosamine and N-acetyl-beta-D-mannose, but more strongly by D-galactose. The apparent molecular mass of the purified lectin was evaluated by Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). Electrophoretic analysis revealed a single protein band with an apparent molecular mass of 56 kDa. Thus, it could be concluded that a lectin was purified from Spirogyra spp.
Subject(s)
Plant Lectins/isolation & purification , Spirogyra/chemistry , Hemagglutination Tests , Carbohydrates/isolation & purification , Carbohydrates/classification , Chromatography, Affinity , Plant Lectins/chemistry , Electrophoresis, Polyacrylamide Gel , Fresh WaterABSTRACT
Los carbohidratos simples como el azúcar, se encuentran en una gran cantidad de alimentos como tortas,caramelos, helados, refrescos, gaseosas y bocadillos. Los edulcorantes son sustancias artificiales que se clasifican en nutritivos, y no nutritivos o no calóricos. Para que los edulcorantes fueran aprobados por la Food Drugs Administration (FDA), han pasado por una serie de pruebas farmacológicas y toxicológicas paradeterminar si su uso es seguro. Las dosis o cantidades seguras de consumo se denominan ingesta diariaaceptable o admisible que puede ser consumida por las personas en forma mantenida sin riesgo apreciable para la salud. Su uso de manera moderada, puede ser de gran utilidad en el manejo de una dieta balanceada o con disminución en las calorías totales, para conservar el peso adecuado o controlar la ganancia y mantenerniveles de glicemia lo más cercano a lo normal. Aún queda mucho por investigar en relación con los edulcorantes y los datos hasta el momento indican que son seguros.
Carbohydrates as the simple sugar found in a variety of foods such as cakes, candy, ice cream, soft drinks and snacks. Artificial sweeteners are substances that are classified as nutritive and non-nutritive or non-caloric. For sweeteners are approved by the Food Drugs Administration (FDA), have gone through a series of pharmacological and toxicological tests to determine if their use is safe. Safe doses or quantities ofconsumption are called acceptable daily intake or intake (ADI) that can be consumed by people in theform maintained without appreciable health risk. Its use in moderation, can be very useful in managing abalanced diet or decrease in total calories, to keep the weight or gain and maintain control of blood glucoselevels as close to normal. Much remains to be investigated in relation to sweeteners and the data so farindicate they are safe.
Subject(s)
Humans , Male , Female , Child , Sweetening Agents/administration & dosage , Sweetening Agents/classification , Sweetening Agents , Sweetening Agents/adverse effects , Sweetening Agents , Carbohydrates/analysis , Carbohydrates/classification , Carbohydrates/pharmacology , Carbohydrates/toxicityABSTRACT
En niños con infección por VIH/SIDA, existen diferentes métodos para estimar las necesidades de proteína y energía. Estos requerimientos pueden ser estimados, sustituyendo la ingesta diaria recomendada (IDR) por proteína, o incrementando la IDR de proteína entre 50%-100%. Los lípidos ayudan a aumentar el aporte energético. La restricción de carbohidratos simples, se hará en el caso de presentar resistencia periférica a la insulina, al igual que cuando se presente hipertrigliceridemia. Es necesario mantener una buena hidratación para asegurar el equilibrio hidroelectrolítico. El objetivo del soporte nutricional especial, tiene que estar encaminado a preservar la masa grasa y mantener los niveles adecuados de nutrimentos y minimizar los síntomas de malabsorción. De preferencia se deberá utilizar la vía oral ó enteral. Aunque muchos estudios reportan la transmisión del VIH a través de la leche materna, la proporción y la epidemiología no está completamente establecida.
In children with HIV/AIDS infection, there are different methods for estimating protein and energy needs. These requirements can be estimated by replacing the recommended daily intake (RDI) for protein, or increasing the RDA of protein between 50%-100%. Lipids help to increase energy intake. The restriction of simple carbohydrates, will be presented in the case of peripheral insulin resistance, like when presented hypertriglyceridemia. Must be maintained to ensure good hydration and electrolyte balance. The purpose of the special nutritional support, must be designed to preserve body fat and maintain proper levels of nutrients and minimize symptoms of malabsorption. Preferably it should use the oral or enteral. Although many studies report HIV transmission through breast milk, the proportion and epidemiology is not fully established.
Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , HIV Infections/classification , HIV Infections/diagnosis , HIV Infections/metabolism , Child Nutrition , Carbohydrates/classification , Lipids/analysis , Lipids/classification , Minerals , Nutritional Requirements , Vitamins/classification , VitaminsABSTRACT
O estudo dos carboidratos dissolvidos e sua relação com as algas abundantes no reservatório de Barra Bonita, foi realizado em coletas mensais (junho de 2002 a janeiro de 2004), em seis profundidades na coluna d'água, cujos valores variaram dependendo da estação do ano e do nível do reservatório, num ponto fixo, localizado 3 km a montante da barragem. Aproximadamente 90 por cento dos carboidratos dissolvidos neste reservatório foram constituídos por carboidratos poliméricos hidrolisáveis (polissacarídeos ou oligossacarídeos). A análise de variância detectou variabilidade entre as concentrações dos carboidratos dissolvidos apenas em escala temporal (p < 0,05), sendo que no eixo vertical, as concentrações destes açúcares apresentaram-se homogêneas (p > 0,05). A composição monossacarídica dos açúcares encontrados no reservatório foi galactose, ramnose, glicose e fucose. Na maioria dos meses amostrados, as concentrações de carboidratos dissolvidos, a maioria deles poliméricos, ocorreram concomitantemente ao registro de florescimentos das espécies abundantes, principalmente cianofíceas, que provavelmente foram as principais fontes de polissacarídeos extracelulares para o sistema.
Dissolved carbohydrates and abundant algae of Barra Bonita Reservoir were studied monthly from June 2002 to January 2004 in six depths whose values vary depending on the seasons and the water level at a sampling site located 3 km upstream the Reservoir dam. Nearly 90 percent of the dissolved carbohydrates were constituted of polymeric hydrolysable carbohydrates (polysaccharides or oligosaccharides). Analysis of variance detected variability among concentrations of dissolved carbohydrates only in temporal scale (p < 0.05), whereas in vertical axis the concentrations of these sugars were uniform (p > 0.05). The monosaccharide composition of the sugars found in the reservoir was galactose, rhamnose, glucose e fucose. During the sampling period, higher concentrations of dissolved carbohydrates, mostly polymeric, occurred together with large phytoplanktonic blooms, predominantly cyanobacteria, which probably were the main source of extracellular polysaccharides in the system.
Subject(s)
Carbohydrates/analysis , Carbohydrates/classification , Carbohydrates/adverse effects , Eukaryota/classification , Eukaryota/growth & development , Aquatic Flora/analysis , Aquatic Flora/classificationABSTRACT
Säo abordados aspectos atuais dos processos de digestäo e absorçäo dos carboidratos que representam a maior fonte energética da alimentaçäo humana. Os estudos mais recentes têm mostrado que o amido pode näo ser totalmente hidrolisado e absorvido no intestino delgado, como se pensava até há pouco. Alguns fatores sao listados como determinantes da velocidade e totalidade da digestäo e absorçäo dos carboidratos. Compreendendo estes conceitos, uma classificaçäo baseada somente no tamanho do composto näo fornece dados precisos sobre o real aproveitamento dos carboidratos pelo organismo humano. De acordo com o tamanho do carboidrato, podemos classificá-lo em: a) monossacarídios; b) dissacarídios; c) oligossacarídios; d) polissacarídios. De acordo com sua digestibilidade ou disponibilidade, os carboidratos sao classificados como: a) carboidratos digeríveis; b) carboidratos nao-digeríveis. A digestibilidade destes carboidratos é alterada por alguns fatores, tais como: Fatores intrínsecos: a) forma física; b) distribuiçäo física da molécula; c) estado do alimento; d) fatores antinutricionais no alimento. Fatores extrínsecos: a) mastigaçäo; b) tempo de trânsito do alimento da boca até o íleo terminal; c) quantidade do amido presente; d) presença de fatores antinutricionais na dieta. Determinado por estes fatores acima, o processo digestivo ocorre pela açäo de enzimas distribuídas ao longo do trato gastrointestinal. Säo as amilases salivar e pancreática, as glicosidases da borda em escova do enterócito duodenal, a lactase, a sacarase a maltase, cujas atividades acontecem por um mecanismo de interaçäo entre a digestäo e a absorçäo. As etapas do processo absortivo podem ser resumidas em alguns movimentos: 1. Movimento da camada aquosa rente a superfície até a superfície do enterócito; 2. movimento através da membrana da borda em escova com transportadores específicos: a) SGLT1; b) GLUT 5; c) difusao passiva. 3. movimento através da membrana basolateral pelo GLUT2 que faz o transporte da glicose até o espaço intercelular.
Subject(s)
Humans , Carbohydrates/metabolism , Digestion , Carbohydrates/classification , Dietary Carbohydrates/metabolism , Intestinal AbsorptionABSTRACT
The starch and total sugar contents of 20 types of fruit, 28 types of vegetables and six differents herbs, grown in Mexico, were analysed. The selection was based on dietary surgery to identify those foods most widely consumed. Starch was determined by an enzymatic method whilst total sugar was determined gravimetrically. The foods were grouped according to the Southgate classification. Fruits contained little starch (range 0-4g/100g fresh weight (FW) except in the case of the plantain (31g/100g FW starch), ehereas vegetables showed a higher concentration with tubers in the range 10-20g/100g FW starch. Legumes contained 0-5g/100g FW; amongst the capsicum group the chilli poblano had the highest concentration at 1.3g/100g FW starch. The concentration of sugars in fruits ranged from 0,6g/100g FW to 21.1g/100g FW