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Arch. argent. pediatr ; 120(1): 59-66, feb 2022. tab, ilus
Article in English, Spanish | LILACS, BINACIS | ID: biblio-1353500


La lactosa es el principal carbohidrato de la leche materna. Es un disacárido conformado por glucosa y galactosa. Su producción en la glándula mamaria es independiente de la dieta materna. Además de proveer energía, es la única fuente de galactosa de la dieta, necesaria para la síntesis de macromoléculas como oligosacáridos, glicoproteínas y glicolípidos. Favorece la absorción y retención de calcio, magnesio y cinc. Su digestión por la enzima lactasa y posterior absorción tienen lugar en intestino delgado. El déficit de lactasa, que puede ser primario congénito (muy infrecuente), primario tardío o secundario por lesión intestinal, puede generar intolerancia con síntomas como dolor, distensión abdominal, flatulencia y diarrea. En el colon, bifidobacterias y lactobacilos pueden hidrolizarla. El manejo nutricional de la intolerancia deberá hacerse siempre preservando la lactancia materna. La reducción o suspensión de la lactosa deberá ser transitoria y se reemplazarán alimentos suspendidos por otros con adecuados aportes calóricos, proteicos y de minerales y vitaminas.

Lactose is the main carbohydrate present in humanmilk. It is a disaccharide made up of glucoseand galactose. It is produced in the mammaryglands, regardless of maternal diet. In addition toproviding energy, it is the only source of dietarygalactose, necessary for macromolecule synthesis,including oligosaccharides, glycoproteins, andglycolipids. It favors calcium, magnesium, andzinc absorption and retention. Its digestion bylactase and subsequent absorption occurs inthe small intestine. Lactase deficiency may beclassified into congenital primary (very rare),late-onset primary or secondary due to an injuryof the intestine; it may cause intolerance withpain, abdominal distension, abdominal gas, anddiarrhea. In the colon, it may be hydrolyzed bybifidobacteria and lactobacilli. The nutritionalmanagement of intolerance should alwayspreserve breastfeeding. Lactose reduction orelimination should be transient, and eliminatedfood should be replaced with other similar incalorie, protein, mineral, and vitamin content.

Humans , Lactose Intolerance/diagnosis , Lactase/metabolism , Diet , Lactose/metabolism , Milk, Human/metabolism
Electron J Biotechnol ; 49: 14-21, Jan. 2021. graf, tab
Article in English | LILACS | ID: biblio-1291625


BACKGROUND: Milk whey, a byproduct of the dairy industry has a negative environmental impact, can be used as a raw material for added-value compounds such as galactooligosaccharides (GOS) synthesis by bgalactosidases. RESULTS: B-gal42 from Pantoea anthophila strain isolated from tejuino belonging to the glycosyl hydrolase family GH42, was overexpressed in Escherichia coli and used for GOS synthesis from lactose or milk whey. Crude cell-free enzyme extracts exhibited high stability; they were employed for GOS synthesis reactions. In reactions with 400 g/L lactose, the maximum GOS yield was 40% (w/w) measured by HPAEC-PAD, corresponding to 86% of conversion. This enzyme had a strong predilection to form GOS with b(1 ? 6) and b (1 ? 3) galactosyl linkages. Comparing GOS synthesis between milk whey and pure lactose, both of them at 300 g/L, these two substrates gave rise to a yield of 38% (60% of lactose conversion) with the same product profile determined by HPAEC-PAD. CONCLUSIONS: B-gal42 can be used on whey (a cheap lactose source) to produce added value products such as galactooligosaccharides.

Oligosaccharides/biosynthesis , beta-Galactosidase/metabolism , Pantoea , Lactose/metabolism , Recombinant Proteins , Dairying , Whey
Electron. j. biotechnol ; 40: 78-83, July. 2019. tab, graf, ilus
Article in English | LILACS | ID: biblio-1053493


Background: Mathematical modeling is useful in the analysis, prediction, and optimization of an enzymatic process. Unlike the conventional modeling methods, Monte Carlo method has special advantages in providing representations of the molecule's spatial distribution. However, thus far, Monte Carlo modeling of enzymatic system is namely based on unimolecular basis, not suitable for practical applications. In this research, Monte Carlo modeling is performed for enzymatic hydrolysis of lactose for the purpose of real-time applications. Results: The enzyme hydrolysis of lactose, which is conformed to Michaelis­Menten kinetics, is modeled using the Monte Carlo modeling method, and the simulation results prove that the model predicts the reaction kinetics very well. Conclusions: Monte Carlo modeling method can be used to model enzymatic reactions in a simple way for real-time applications.

Monte Carlo Method , Enzymes/metabolism , Hydrolysis , Lactose/metabolism , Time Factors , Kinetics , beta-Galactosidase/metabolism , Enzymes, Immobilized , Galactose/metabolism
Braz. j. microbiol ; 48(2): 251-258, April.-June 2017. tab, graf
Article in English | LILACS | ID: biblio-839382


Abstract Kinetic behaviors of five Lactobacillus strains were investigated with Contois and Exponential models. Awareness of kinetic behavior of microorganisms is essential for their industrial process design and scale up. The consistency of experimental data was evaluated using Excel software. L. bulgaricus was introduced as the most efficient strain with the highest biomass and lactic acid yield of 0.119 and 0.602 g g-1 consumed lactose, respectively. The biomass and carbohydrate yield of L. fermentum and L. lactis were slightly less and close to L. bulgaricus. Biomass and lactic acid production yield of 0.117 and 0.358 for L. fermentum and 0.114 and 0.437 g g-1 for L.actobacillus lactis were obtained. L. casei and L. delbrueckii had the less biomass yield, nearly 11.8 and 22.7% less than L. bulgaricus, respectively. L. bulgaricus (R 2 = 0.9500 and 0.9156) and L. casei (R 2 = 0.9552 and 0.8401) showed acceptable consistency with both models. The investigation revealed that the above mentioned models are not suitable to describe the kinetic behavior of L. fermentum (R 2 = 0.9367 and 0.6991), L. delbrueckii (R 2 = 0.9493 and 0.7724) and L. lactis (R 2 = 0.8730 and 0.6451). Contois rate equation is a suitable model to describe the kinetic of Lactobacilli. Specific cell growth rate for L. bulgaricus, L. casei, L. fermentum, L. delbrueckii and L. lactis with Contois model in order 3.2, 3.9, 67.6, 10.4 and 9.8-fold of Exponential model.

Lactobacillus/growth & development , Lactobacillus/metabolism , Lactose/metabolism , Models, Theoretical , Sweetening Agents/metabolism , Biomass , Lactic Acid/metabolism , Fermentation
Arq. gastroenterol ; 53(4): 228-234, Oct.-Dec. 2016. tab, graf
Article in English | LILACS | ID: lil-794592


ABSTRACT Background Primary hypolactasia is a common condition where a reduced lactase activity in the intestinal mucosa is present. The presence of abdominal symptoms due to poor absorption of lactose, which are present in some cases, is a characteristic of lactose intolerance. , Objective Evaluate the efficacy of a product containing exogenous lactase in tablet form compared to a reference product with proven effectiveness in patients with lactose intolerance. Methods Multicentre, randomized, parallel group, single-blind, comparative non-inferiority study. One hundred twenty-nine (129) adult lactose intolerance patients with hydrogen breath test results consistent with a diagnosis of hypolactasia were randomly assigned to receive the experimental product (Perlatte(r) - Eurofarma Laboratórios S.A.) or the reference product (Lactaid(r) - McNeilNutritionals, USA) orally (one tablet, three times per day) for 42 consecutive days. Results Data from 128 patients who actually received the studied treatments were analysed (66 were treated with the experimental product and 62 with the reference product). The two groups presented with similar baseline clinical and demographic data. Mean exhaled hydrogen concentration tested at 90 minutes after the last treatment (Day 42) was significantly lower in the experimental product treated group (17±18 ppm versus 34±47 ppm) in the per protocol population. The difference between the means of the two groups was -17 ppm (95% confidence interval [95% CI]: -31.03; -3.17). The upper limit of the 95% CI did not exceed the a priori non-inferiority limit (7.5 ppm). Secondary efficacy analyses confirmed that the treatments were similar (per protocol and intention to treat population). The tolerability was excellent in both groups, and there were no reports of serious adverse events related to the study treatment. Conclusion The experimental product was non-inferior to the reference product, indicating that it was an effective replacement therapy for endogenous lactase in lactose intolerance patients.

RESUMO Contexto A hipolactasia primária é uma condição muito frequente na qual há redução da atividade da lactase na mucosa intestinal.A presença de sintomas abdominais devidos à má absorção da lactose presente em alguns casos caracteriza a intolerância à lactose. Objetivo Avaliar a eficácia de um produto contendo lactase exógena em comprimidos comparativamente a de um produto comparador com eficácia comprovada em pacientes portadores de intolerância à lactose. Métodos Estudo multicêntrico, randomizado, de grupos paralelos, com investigador cego, comparativo de não-inferioridade. Cento e vinte e nove (129) pacientes adultos portadores de intolerância à lactose e teste do hidrogênio no ar expirado compatível com o diagnóstico de hipolactasia foram randomizados para receber o produto experimental (Perlatte(r) - Eurofarma Laboratórios S.A.) ou o produto comparador (Lactaid(r) - McNeil Nutritionals, EUA), por via oral (um comprimido, três vezes ao dia), durante 42 dias consecutivos. Resultados Os dados dos 128 pacientes que efetivamente receberam o tratamento do estudo foram avaliados (66 tratados com o produto experimental e 62 com o produto comparador). Os dois grupos se mostraram homogêneos quanto aos dados demográficos e clínicos basais. A média da concentração do hidrogênio expirado aos 90 minutos no teste realizado ao final do tratamento (Dia 42) foi significativamente menor no grupo tratado com o produto experimental (17±18 ppm versus 34±47 ppm na população por protocolo). A diferença entre as médias dos dois grupos foi de -17 ppm (intervalo de confiança de 95% [IC95%]: -31,03; -3,17). O limite superior do IC95% não ultrapassou a margem de não-inferioridade estipulada a priori (7,5 ppm). As análises secundárias de eficácia confirmaram a semelhança entre os tratamentos (populações por protocolo e com intenção de tratamento). A tolerabilidade foi excelente em ambos os grupos e não houve relato de eventos adversos graves relacionados ao produto. Conclusão O produto experimental se mostrou não-inferior ao produto comparador, indicando sua eficácia no tratamento substitutivo da lactase endógena em pacientes portadores de intolerância à lactose.

Humans , Male , Female , Adolescent , Adult , Young Adult , Lactase/administration & dosage , Lactase/deficiency , Lactose Intolerance/drug therapy , Single-Blind Method , Administration, Oral , Treatment Outcome , Hydrogen/analysis , Lactose/metabolism , Lactose Intolerance/diagnosis , Middle Aged
Rev. panam. salud pública ; 38(6): 442-449, nov.-dic. 2015. tab
Article in English | LILACS | ID: lil-788101


OBJECTIVE:To describe the volume and patterns of alcohol consumption up to and including 2012, and to estimate the burden of disease attributable to alcohol consumption as measured in deaths and disability-adjusted life years (DALYs) lost in the Americas in 2012. METHODS: Measures of alcohol consumption were obtained from the World Health Organization (WHO) Global Information System on Alcohol and Health (GISAH). The burden of alcohol consumption was estimated in both deaths and DALYs lost based on mortality data obtained from WHO, using alcohol-attributable fractions. Regional groupings for the Americas were based on the WHO classifications for 2004 (according to child and adult mortality). RESULTS: Regional variations were observed in the overall volume of alcohol consumed, the proportion of the alcohol market attributable to unrecorded alcohol consumption, drinking patterns, prevalence of drinking, and prevalence of heavy episodic drinking, with inhabitants of the Americas consuming more alcohol (8.4 L of pure alcohol per adult in 2012) compared to the world average. The Americas also experienced a high burden of disease attributable to alcohol consumption (4.7% of all deaths and 6.7% of all DALYs lost), especially in terms of injuries attributable to alcohol consumption. CONCLUSIONS: Alcohol is consumed in a harmful manner in the Americas, leading to a high burden of disease, especially in terms of injuries. New cost-effective alcohol policies, such as increasing alcohol taxation, increasing the minimum legal age to purchase alcohol, and decreasing the maximum legal blood alcohol content while driving, should be implemented to decrease the harmful consumption of alcohol and the resulting burden of disease.

OBJETIVO:Describir el volumen y los modelos de consumo de alcohol hasta el año 2012 incluido, y calcular la carga de morbilidad atribuible al consumo de alcohol medida según el número de defunciones y los años de vida ajustados en función de la discapacidad (AVAD) perdidos en la Región de las Américas en el 2012. MÉTODOS: Los datos sobre el consumo de alcohol se obtuvieron a partir del Sistema Mundial de Información sobre el Alcohol y la Salud (GISAH, por sus siglas en inglés) de la Organización Mundial de la Salud (OMS). La carga del consumo de alcohol se calculó según la mortalidad y según los AVAD perdidos con base en los datos de mortalidad obtenidos de la OMS, tomando en consideración las fracciones atribuibles al alcohol. La división en subregiones se basó en las clasificaciones de la OMS del año 2004 (según la mortalidad en niños y adultos). RESULTADOS: Se observaron variaciones regionales en el volumen total de alcohol consumido, la proporción del mercado del alcohol atribuible al consumo de alcohol no registrado, los hábitos de consumo, la prevalencia del consumo y la prevalencia de los episodios de consumo excesivo de alcohol. Los habitantes de la Región de las Américas consumieron más alcohol (8,4 litros de alcohol puro por adulto en el 2012) en comparación con el promedio mundial. La Región también experimentó una alta carga de morbilidad atribuible al consumo de alcohol (4,7% de las defunciones y 6,7% de los AVAD perdidos), especialmente en forma de lesiones atribuibles al consumo de alcohol. CONCLUSIONES: El alcohol se consume de una manera perjudicial en la Región de las Américas y ello comporta una alta carga de morbilidad, especialmente en forma de lesiones. Con objeto de disminuir el consumo perjudicial de bebidas alcohólicas y la carga de morbilidad resultante, es preciso introducir nuevas políticas en materia de consumo de alcohol que sean eficaces en función de los costos, tales como el incremento de los impuestos sobre el alcohol, el aumento de la edad mínima legal para adquirir alcohol, y la disminución de la concentración máxima legal de alcohol en sangre mientras se conduce.

Bacterial Proteins/chemistry , Neuraminidase/chemistry , Streptococcus pneumoniae/enzymology , Virulence Factors/chemistry , Binding Sites , Bacterial Proteins/metabolism , Lactose/analogs & derivatives , Lactose/metabolism , Models, Molecular , Neuraminidase/metabolism , Protein Binding , Protein Folding , Protein Structure, Tertiary , Sialic Acids/metabolism , Streptococcus pneumoniae/chemistry , Virulence Factors/metabolism
Braz. j. microbiol ; 46(3): 753-757, July-Sept. 2015. tab, ilus
Article in English | LILACS | ID: lil-755797


Quinolones and fluoroquinolones are widely used to treat uropathogenic Escherichia coli infections. Bacterial resistance to these antimicrobials primarily involves mutations in gyrA and parC genes. To date, no studies have examined the potential relationship between biochemical characteristics and quinolone resistance in uropathogenic E. coli strains. The present work analyzed the quinolone sensitivity and biochemical activities of fifty-eight lactose-negative uropathogenic E. coli strains. A high percentage of the isolates (48.3%) was found to be resistant to at least one of the tested quinolones, and DNA sequencing revealed quinolone resistant determining region gyrA and parC mutations in the multi-resistant isolates. Statistical analyses suggested that the lack of ornithine decarboxylase (ODC) activity is correlated with quinolone resistance. Despite the low number of isolates examined, this is the first study correlating these characteristics in lactose-negative E. coli isolates.


Humans , Drug Resistance, Multiple, Bacterial/genetics , Escherichia coli Infections/drug therapy , Fluoroquinolones/therapeutic use , Lactose/metabolism , Nalidixic Acid/therapeutic use , Ornithine Decarboxylase/genetics , Urinary Tract Infections/drug therapy , Uropathogenic Escherichia coli/genetics , Anti-Bacterial Agents/therapeutic use , Brazil , DNA Gyrase/genetics , DNA Topoisomerase IV/genetics , Decarboxylation/genetics , Decarboxylation/physiology , Escherichia coli Infections/microbiology , Microbial Sensitivity Tests , Ornithine/metabolism , Urinary Tract Infections/microbiology , Uropathogenic Escherichia coli/drug effects , Uropathogenic Escherichia coli/enzymology , Uropathogenic Escherichia coli/isolation & purification
Article in English | WPRIM | ID: wpr-65167


The purpose of this study was to evaluate the capacity of a lactic acid bacteria (LAB) inoculum to protect calves with or without lactose supplements against Salmonella Dublin infection by evaluating histopathological lesions and pathogen translocation. Fifteen calves were divided into three groups [control group (C-G), a group inoculated with LAB (LAB-G), and a group inoculated with LAB and given lactose supplements (L-LAB-G)] with five, six, and four animals, respectively. The inoculum, composed of Lactobacillus (L.) casei DSPV 318T, L. salivarius DSPV 315T, and Pediococcus acidilactici DSPV 006T, was administered with milk replacer. The LAB-G and L-LAB-G received a daily dose of 109 CFU/kg body weight of each strain throughout the experiment. Lactose was provided to the L-LAB-G in doses of 100 g/day. Salmonella Dublin (2 x 1010 CFU) was orally administered to all animals on day 11 of the experiment. The microscopic lesion index values in target organs were 83%, 70%, and 64.3% (p < 0.05) for the C-G, LAB-G, and L-LAB-G, respectively. Administration of the probiotic inoculum was not fully effective against infection caused by Salmonella. Although probiotic treatment was unable to delay the arrival of pathogen to target organs, it was evident that the inoculum altered the response of animals against pathogen infection.

Administration, Oral , Animals , Animals, Newborn , Cattle , Cattle Diseases/drug therapy , Dietary Supplements/analysis , Feces/microbiology , Lactobacillus/metabolism , Lactose/metabolism , Male , Pediococcus/metabolism , Probiotics/therapeutic use , Salmonella Infections, Animal/drug therapy , Salmonella enterica/drug effects , Tissue Distribution
Indian J Pathol Microbiol ; 2006 Oct; 49(4): 626-30
Article in English | IMSEAR | ID: sea-75356


We propose a simple scheme for the identification of enterobacteriaceae species which routinely necessitates numerous biochemical tests and prolonged time span. In the scheme, family enterobacteriaceae is initially divided into four major groups depending on two important biochemical reactions viz. Lactose fermentation (L) and Methyl red test (MR). Each of the four groups, Group I (L + MR+), Group II (L + MR-), Group III (L- MR-), Group IV (L- MR+) can further be differentiated by using few tests. Eleven genera and 23 species can be identified by this scheme using limited biochemical tests. As many as 990 strains of enterobacteriaceae were subjected to standard biochemical tests and proposed simple scheme for identification. The discrepancy was observed only with 8 atypical strains of E. coli.

Azo Compounds/metabolism , Bacterial Typing Techniques , Bacteriological Techniques , Enterobacteriaceae/classification , Humans , Lactose/metabolism , Species Specificity
Arq. bras. endocrinol. metab ; 50(5): 852-861, out. 2006. tab
Article in Portuguese, English | LILACS | ID: lil-439066


O cálcio (Ca) dietético é fundamental para a saúde óssea. Tanto o teor como a biodisponibilidade do elemento nos alimentos devem ser considerados. Este artigo objetiva sumarizar os fatores envolvidos na absorção e destacar os alimentos com melhor disponibilidade do Ca. Este é absorvido principalmente no jejuno e o pH baixo parece favorecer sua absorção, que é maior no crescimento, na gestação/lactação e na carência de Ca ou fósforo (P), e menor no envelhecimento. As maiores fontes, e com melhor absorção, são os laticínios bovinos. Outros alimentos apresentam concentrações elevadas de Ca, mas com biodisponibilidade variável: os ricos em ácidos oxálico e fítico apresentariam uma menor absorção, enquanto que os ricos em carboidratos teriam uma absorção maior. Por apresentarem uma biodisponibilidade do Ca mais próxima da do leite bovino, o leite de outros animais, o de soja enriquecido e alguns vegetais, em quantidades adequadas, poderiam ser usados como alternativas a este.

Dietary calcium (Ca) is fundamental to the bone's health. Both the purport and the element bioavailability in the food need to be considered. The purpose of this work was to summarize the factors involved in Ca absorption and point out the sources with higher bioavailability. Ca is mostly absorbed in the jejunum and low pH seems to favor its absorption, which is higher during growth, gestation/lactation and Ca and phosphorus (P) deficiency, and lower with aging. The richest and best-absorbed Ca source is cow's milk and its derivatives. Other foods show high Ca concentrations but variable bioavailability: foods rich in phytates and oxalates show a smaller absorption and carbohydrate-rich foods show higher absorption. Since Ca bioavailability in other animal's milk, soymilk and some vegetables is closer to that in cow's milk, adequate amounts of these foods could be used as an alternative.

Humans , Animals , Male , Female , Bone Density Conservation Agents/pharmacokinetics , Bone Resorption/metabolism , Calcium, Dietary/pharmacokinetics , Diet , Intestinal Absorption/physiology , Nutritional Requirements , Biological Availability , Bone Density/physiology , Calcium Carbonate/metabolism , Calcium/deficiency , Lactation/metabolism , Lactose Intolerance/metabolism , Lactose/metabolism , Milk/metabolism , Osteoporosis/diet therapy , Osteoporosis/prevention & control , Soy Milk/pharmacokinetics , Vegetables/metabolism
Hig. aliment ; 21(140): 24-29, abr. 2006. tab
Article in Portuguese | LILACS | ID: lil-437923


A lactose está presente em diversos tipos de leite e todos os mamíferos, inclusive o ser humano, quando nascem em condições normais, estão aptos a digerir este açúcar. No entanto, aproximadamente 75 por cento da população mundial é intolerante à lactose. Para a lactose ser assimilada pelo organismo é necessário que seja hidrolisada no intestino delgado, pela ação da enzima lactase, também chamada de beta galactosidase, em: galactose e glicose. Na ausência da lactose na mucosa intestinal, a lactose não pode ser absorvida e utilizada. No cólon os microorganismos a fermentam, resultado em ácidos e gases, aparecendo sintomas clínicos como: diarréia, flatulência, dores de barriga e inchaço no abdômen. O tratamento da intolerância à lactose consiste basicamente na retirada ou diminuição desse açúcar da dieta, o que leva ao desaparecimento progressivo dos sintomas. Uma das grandes preocupações com a redução da lactose da alimentação é a garantia do fornecimento de quantidade apropriada de proteínas, cálcio, riboflavina e vitamina D, cuja maior fonte é o leite e seus derivados. É de fundamental importância um planejamento dietético apropriado em crianças, que assegura um crescimento satisfatório. Com o intuito de propiciar um melhor tratamento nutricional à pacientes intolerantes à lactose este trabalho tem por objetivo apresentar o teor de lactose em alimentos que são geralmente consumidos por crianças obtido através de pesquisa junto à algumas indústrias alimentícias, bem como apresentar um cardápio balanceado e equilibrado para crianças na faixa etária de 4 a 6 anos, que contribua para a prevenção de possíveis carências nutricionais.

Humans , Child , Child Nutrition , Diet Therapy , Lactose Intolerance , Lactose/adverse effects , Lactose/metabolism
Article in English | IMSEAR | ID: sea-124497


Lactase activity with age has been reported in a wide variety of population globally. However, most of these studies in human have ignored to assess age stratified lactose maldigestion. Therefore, the present study was planned to determine lactose maldigestion in different age groups of north Indians adults. Two hundred apparently healthy north Indians (age rage 10-80 years) were subjected to a 50g lactose hydrogen breath test by standard method using a Model 12 Microlyzer from Quintron, USA. The percentage of lactose maldigestion was calculated for different age groups with an interval of 10 years. The results of this study revealed that the frequency of lactose maldigestion did not differ significantly among the age groups. Thus, this study suggests that lactose maldigestion is not associated with age stratification among north Indians.

Adolescent , Adult , Age Distribution , Aged , Aged, 80 and over , Breath Tests , Child , Female , Humans , India/epidemiology , Lactose/metabolism , Lactose Intolerance/epidemiology , Male , Middle Aged
Biocell ; 27(1): 37-46, Apr. 2003.
Article in English | LILACS | ID: lil-384252


Amphibians respond to microbial infection through cellular and humoral defense mechanisms such as antimicrobial protein secretion. Most humoral defense proteins are synthetized in the skin. In this study we isolated two beta-galactoside-binding lectins with molecular weights of 50 and 56 KDa from the skin of Bufo arenarum. These lectins have significant hemagglutination activity against trypsinized rabbit erythrocytes, which was inhibited by galactose-containing saccharides. They are water-soluble and independent of the presence of calcium. The antimicrobial analysis for each lectin was performed. At mumolar concentration lectins show strong bacteriostatic activity against Gram negative bacteria (Escherichia coli K12 4100 and wild strains of Escherichia coli and Proteus morganii) and Gram positive bacteria (Enterococcus faecalis). The antibacterial activity of these lectins may provide an effective defense against invading microbes in the amphibian Bufo arenarum.

Anti-Bacterial Agents/pharmacology , Bufo arenarum/metabolism , Lectins/pharmacology , Skin/chemistry , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Bufo arenarum/anatomy & histology , Enterococcus faecalis/drug effects , Escherichia coli/drug effects , Hemagglutination Tests , Hemagglutinins/metabolism , Lactose/metabolism , Lectins/metabolism , Proteus/drug effects , Rabbits
Rev. microbiol ; 28(4): 273-8, out.-dez. 1997. ilus
Article in English | LILACS | ID: lil-240695


Eight lactose-fermenting Salmonella agona strains isolated in a pediatric unit were characterized by classic and molecular methods. The strains were classified as biotypes 1a, corresponding to the most frequen one in Brazil. None of the strains produced colicin. Multiple resistence to antimicrobials was observed among the strains studied, It was demonstrated that the lactose-fermenting character was encoded by a plasmid with spontaneous segregaton at a frequency of 1 percer center. This plasmid was transferable by conjugation at a frequency between 4x10(-8) and 5x10(-10). The lac+ plasmid, which molecular weight was approximately 90 MDa, encoded both lactose fermentation and multiple resistance to antimicrobials. Replicon typing showed that this plasmid did not belong to the known types, suggesting the present of a new replicon type. Classic methods showed that the studied strains had the same characteristics as the clone widely occurring in our area, differing only by lactose-fermenting ability. This conclusion was supported by the results of ribotyping study.

Humans , Infant , Child, Preschool , Diarrhea/microbiology , Lactose/metabolism , Drug Resistance, Microbial , Salmonella/metabolism , Acute Disease , Bacterial Typing Techniques , Fermentation
Indian J Biochem Biophys ; 1997 Jun; 34(3): 249-52
Article in English | IMSEAR | ID: sea-29074


Sugar-specific binding of bovine brain 14 kDa galactose-binding lectin (BBL) to individual endogenous gangliosides (GM1, GM2, GD1a, GD1b and GT1b) was studied using affinity electrophoresis of ganglioside-lectin mixture in polyacrylamide gel at pH 8.3. Unbound (free) lectin moved ahead while ganglioside-lectin complex moved very little. Sugar-specificity of binding was confirmed by reversal of the interaction by (i) presence of lactose along with the lectin and (ii) pretreatment of gangliosides with another galactose-binding lectin, Ricinus communis agglutinin. Stoichiometry of ganglioside-BBL interaction revealed that GT1b had the highest affinity for the lectin followed by GD1b and GM2, while GM1 and GD1a had the least affinity. Results indicated that a terminal sialic acid moiety covering a galactose moiety may at times enhance BBL recognition of the latter and that changes in ganglioside pattern is a possible modulator of lectin function in vivo.

Animals , Binding, Competitive , Brain/metabolism , Cattle , Electrophoresis, Polyacrylamide Gel , Galectins , Gangliosides/chemistry , Hemagglutinins/metabolism , Lactose/metabolism , Lectins/metabolism , N-Acetylneuraminic Acid/metabolism , Plant Lectins
Braz. j. med. biol. res ; 30(6): 723-6, jun. 1997. ilus
Article in English | LILACS | ID: lil-194171


Ninety-six weanling male Wistar rats were fed for four weeks one of two different chows: a normal rat chow containing 55.5 percent (w/w) starch (control group, N = 48) or a rat chow in which starch was partially replacced by lactose, in such a way that the experimental group (N = 48) received 35.3 per cent (w/w) starch and 20 percent (w/w) lactose. The gastric emptying of fluid was then studied by measuring the gastric retention of four test meals containing lactose (5 percent or 10 percent, w/v) or glucose + galactose (5 percent or 10 percent, w/v). Homogenates of the small intestine were assayed for lactase activity. The gastric retention values were obtained 15 min after orogastric infusion of the liquid meals. The median values for gastric retention of the 5 percent lactose solutions were 37.7 percent for the control group and 37.0 percent for the experimental group (P>0.02) For the 10 percent lactose solution the median values were 51.2 percent and 47.9 percent (P>0.02) for the control and experimental groups, respectively. However, for the 2.5 percent glucose + 2.5 percent galactose meal the median gastric retention was lower (P<0.02) in the group fed a lactose-enriched chow (38.5 percent) than in the control group (41.6 percent). For the 5 percent glucose + 5 percent galactose solution the median values were not statistically different between groups, 65.0 percent for the control group and 58.8 percent for the experimental group. The median values of the specific lactase activity in the small intestine homogenate was 0.74 U/g in the control group and 0.91 U/g in the experimental group. These values were not statistically different (P>0.05). These results suggest that the prolonged ingestion of lactose by young adult rats changes the gastric emptying of a solution containing 5 percent monosaccharides. This adaptation may reflect the desensitization of intestinal nutrient receptors, possibly by an osmotic effect of lactose present in the chow.

Male , Animals , Rats , Disaccharides/metabolism , Gastric Emptying/physiology , Gastrointestinal Motility/physiology , Lactose/metabolism , Monosaccharides/metabolism , Lactose/administration & dosage , Rats, Wistar
Arq. gastroenterol ; 33(1): 10-6, jan.-mar. 1996. tab, graf
Article in Portuguese | LILACS | ID: lil-163863


É sabido que a lactose é melhor absorvida sob forma de iogurte que de leite, por indivíduos hipolactásicos e que este fenômeno se deve à presença de atividade de beta-galactosidase nos iogurtes, que difere segundo as características dos produtos. Assim, o objetivo deste trabalho foi estudar a absorçao e a tolerância à lactose de alguns iogurtes utilizados em nosso meio. Foram estudados 12 adultos portadores de hipolactasia tipo adulto. Após a confirmaçao diagnóstica, os voluntários foram submetidos a três testes com ingestao de leite e dois tipos de iogurte com diferentes níveis de beta-galactosidase. Esta atividade foi determinada em cada amostra utilizada. A absorçao da lactose foi calculada pela medida do H2 eliminado no ar expirado e a tolerância avaliada por um escore de sintomas referidos pelos participantes. As medianas do incremento de H2 foram de 20 ppm para o leite, 1O.5 para o iogurte X e 5.5 para o iogurte Y. A área sob a curva apresentou mediana de 96O ppm/min no teste com leite, 42Oppm/min com o iogurte X e 27Oppm/min com o iogurte Y. Estes dois dados apresentaram diferenças estatisticamente significativas quando se comparou o leite com cada iogurte e nao significativas comparando-se os dois iogurtes entre si. Os escores de sintomas também foram significantemente diferentes entre o leite e os dois iogurtes e semelhantes entre os iogurtes. Nao se observou associaçao estatisticamente significante entre absorçao e tolerância. No entanto, a maioria dos intolerantes nao absorveu o açúcar. Estes dados indicam que a lactose dos iogurtes foi melhor absorvida e melhor tolerada que a do leite, o que vem sugerir que nossos produtos se assemelham à maioria daqueles da literatura, no que se refere à sua capacidade desdobradora de lactose "in vivo". Apesar das diferenças, medidas "in vitro", entre as atividades de beta-galactosidase, nao houve diferenças significativas de absorçao e tolerância entre os dois iogurtes.

Humans , Adult , beta-Galactosidase/metabolism , Lactose Intolerance/metabolism , Lactose/metabolism , Milk , Yogurt
Medicina (B.Aires) ; 55(3): 237-42, mayo-jun. 1995. graf
Article in Spanish | LILACS | ID: lil-155116


El propósito fue determinar si una leche no comercial fermentada con Lactobacillus casei y Lalctobacillus acidophilus de origen humano (LFC) que fuera desarrollada por CERELA (Centro de Referencia para Lactobacilos) es mejor tolerada que la leche común (LC) por sujetos con deficiencia de lactasa (<1 unidad/g de tejido fresco) e intolerancia a la lactosa. Fueron estudiados 18 individuos sanos con deficiencia de lactasa intestinal e intolerancia a la lactosa, y 12 controles. Las preparaciones lácteas consistieron en 480 ml y 240 ml de LFC y LC. Se usó la prueba del H2 en el aire espirado para medir el grado de absorción de la lactosa y el tiempo de tránsito boca ciego (TTBC), y se evaluó la sintomatología clínica después de la administración de cada una de las preparaciones. La excreción de Ha luego de 480 ml de LFC fue de 19,5 ñ 12,1 ppm versus 52,6 ñ 31,9 ppm obtenido con igual dosis de LC (p < 0,0008). Los resultados también mostraron que 480 ml de la LFC prolonga significativamente el TTBC 111,0 ñ 6,78 minutos versus 54,0 ñ 5,09 minutos de LC (p < 0,001) y reduce la presencia de síntomas clínicos (p < 0,08) especialmente los borborismos (p < 0,025), el meteorismo (p < 0,05), la diarrea (p < 0,05) y los cólicos abdominales (p < 0,05). Se concluye que la LFC mejora la digestión de la lactosa, influye sobre el TTBC y disminuye la presencia de síntomas de intolerancia en sujetos con hipolactasia e intolerancia clínica a la lactosa

Humans , Male , Female , Adult , Middle Aged , Lactose Intolerance/diagnosis , Lactose/metabolism , Milk/metabolism , Gastrointestinal Transit , Hydrogen/metabolism , Lactobacillus acidophilus/metabolism , Lactobacillus casei/metabolism , Random Allocation