ß-defensin-2 in breast milk displays a broad antimicrobial activity against pathogenic bacteria / ß-defensina 2 no leite materno mostra uma ampla atividade antimicrobiana contra bactérias patogênicas

OBJECTIVE: To describe the antimicrobial activity of ß-defensin-2 produced in the mammary gland and secreted in human breast milk. METHODS: The peptide production was performed by DNA cloning. ß-defensin-2 levels were quantified in 61 colostrum samples and 39 mature milk samples from healthy donors, by an indirect enzyme-linked immunosorbent assay (ELISA). Using halo inhibition assay, this study assessed activity against seven clinical isolates from diarrheal feces of children between 0 and 2 years of age. The activity of ß-defensin-2 against three opportunistic pathogens that can cause nosocomial infections was determined by microdilution test. RESULTS: The peptide levels were higher in colostrum (n = 61) than in mature milk samples (n = 39), as follows: median and range, 8.52 (2.6-16.3) µg/ml versus 0.97 (0.22-3.78), p < 0.0001; Mann-Whitney test. The recombinant peptide obtained showed high antimicrobial activity against a broad range of pathogenic bacteria. Its antibacterial activity was demonstrated in a disk containing between 1-4 µg, which produced inhibition zones ranging from 18 to 30 mm against three isolates of Salmonella spp. and four of E. coli. ß-defensin-2 showed minimum inhibitory concentrations (MICs) of 0.25 µg/mL and 0.5 µg/mL for S. marcescen and P. aeruginosa, respectively, while a higher MIC (4 µg/mL) was obtained against an isolated of multidrug-resistant strain of A. baumannii. CONCLUSIONS: To the authors' knowledge, this study is the first to report ß-defensin-2 levels in Latin American women. The production and the activity of ß-defensin-2 in breast milk prove its importance as a defense molecule for intestinal health in pediatric patients. .

OBJETIVO: Descrever a atividade antimicrobiana da defensina-beta 2 na glândula mamária e secretada no leite materno humano. MÉTODOS: A produção de peptídeos foi realizada por clonagem de DNA. Os níveis de defensina-beta 2 foram quantificados em 61 amostras de colostro e 39 de leite maduro de doadoras saudáveis pelo teste ELISA indireto. Por um ensaio de halo de inibição, avaliamos a atividade contra sete isolados clínicos diarreicos de crianças entre 0 e 2 anos. A atividade da defensina 2 contra três patógenos oportunistas que podem causar infecções nosocomiais foi determinada pelo teste de microdiluição. RESULTADOS: Os níveis de peptídeos estavam significativamente maiores nas amostras de colostro (n = 61) que de leite maduro (n = 39), como segue: 8,52 (2,6-16,3 µg/mL) mediana e faixa em comparação a 0,97 (0,22-3,78), p < 0,0001; teste de Mann-Whitney. O peptídeo recombinante foi obtido da alta atividade antimicrobiana demonstrada contra uma ampla gama de bactérias patogênicas. Sua atividade antibacteriana foi demonstrada em um disco contendo entre 1-4 µg, que produziu zonas de inibição entre 18 e 30 mm contra três isolados de Salmonella spp. e quatro de E. coli. A defensina-beta 2 demonstrou concentrações inibitórias mínimas (CIMs) de 0,25 µg/mL e 0,5 µg/mL para S. marcescen and P. aeruginosa, ao passo que uma CIM maior (4 µg/mL) foi obtida contra um isolado de cepa multirresistente de A. baumannii. CONCLUSÕES: Até onde sabemos, este estudo é o primeiro a relatar níveis de defensina em mulheres da América Latina. A produção e a atividade da defensina 2 no leite materno comprovam sua importância como uma molécula de defesa para a saúde intestinal em pacientes pediátricos. .

Inseminación artificial a tiempo fijo en vacas brahman lactantes / Artificial insemination at fixed time in lactating cows brahman

Objetivo. Evaluar el efecto de los días de lactancia sobre la tasa de gestación con inseminación artificial a tiempo fijo (IATF). Materiales y métodos. Se utilizaron 54 vacas multíparas brahman lactantes; sincronizadas con un protocolo a base de progesterona, benzoato de estradiol, eCG y prostaglandina. Se dividieron en dos grupos: G1: vacas < 110 días de lactancia (n=27); G2: vacas > 110 días de lactancia (n=27). Las vacas fueron inseminadas a las 30 horas de aplicación de la segunda dosis de benzoato. Las variables se analizaron por medio de la prueba de Chi². Resultados. No se presentó efecto (p>0,05) de los tratamientos sobre los porcentajes de preñez con IATF, obteniendo 29.6% y 22.2% para los tratamientos G1 y G2 respectivamente. Conclusiones. Los días de lactancia no tuvieron efecto sobre la tasa de gestación con IATF.

Evaluation of the secretory immunoglobulin A levels in the colostrum and milk of mothers of term and pre-trerm newborns

OBJECTIVE: To determine and to compare the levels of secretory immunoglobulin A in samples of colostrum and milk of mothers of term and preterm neonates. MATERIAL AND METHODS: The levels of secretory immunoglobulin A of 10 mothers of term neonates and 10 mothers of preterm neonates were determined from 5mL of colostrum or milk collected on the 1st, 4th, 10th and 15th days of the puerperal period, using the radial immunodifusion technique. We employed anamnesis, as well as physical and gynecological exams in women in the puerperal period. All the patients were attended at the Januário Cicco Maternity College. RESULTS: The secretory immunoglobulin A levels were significantly higher in the colostrum and milk of mothers of preterm neonates when compared with the levels found in colostrum and milk of mothers of term neonates (Mann-Whitney test, p<0.0001). There was a significant decline in the secretory immunoglobulin A levels of the colostrum and milk of the mothers of term and preterm neonates during the four periods (Kruskal-Wallis test, p<00001). CONCLUSIONS: The secretory immunoglobulin A levels in colostrum and milk of mothers of preterm neonates were significantly higher than in the mothers of term neonates, demonstrating immunological adaptation in preterm neonate breast-feeding.

IgA secretora total e específica no colostro e leite de mães da cidade do Natal-Rio Grande do Norte, Brasil / Total and specific IgA in colostrum and milk of mothers of Natal-Rio Grande do Norte, Brasil

PURPOSE: To determine the concentration of total secretory IgA and evaluate the repertoire of IgA antibodies to enteropathogenic Escherichia coli and Shigella flexneri antigens in colostrums and milk from mothers in Natal, RN. METHODS: The sample was constituted by 22 healthy clinically women whose babies were born at public hospital in Natal, RN. To determine total secretory IgA a radial immunedifusion tecnique (Mancini et al, 1965), was employed and to detect specific antibodies, immuneenzimatic assays, ELISA was used. RESULTS: The median values of total secretory IgA concentration presented individual variations with high levels in colostrums samples, decreasing during lactation, it was observed a p < 0.001 among the samples from the first day of lactation, to the thirtieth for total IgA concentration. All the donators present in colostrum and milk specific antibodies to Escherichia coli enteropathogenic (EPEC) and Shigella flexneri with titles higer in colostrum. There was parallel and directional pattern between total IgA and IgA anti-EPEC and Shegella flexneri, during period. CONCLUSION: The concentrations of total SIgA and specific antibodies to enteropathogenic Escherichia coli and Shigella flexneri in colostrums and milk in our study do not differ from others accomplished among populations with the same social and econimic features, stressing the importance of human milk as a protector agent against pathogens.

Morbilidad infecciosa gastrointestinal y respiratoria en lactantes amamantados / Diarrheic and respiratory infections in breastfeded neonates

La leche materna protege de las infecciones diarreicas y respiratorias, ante la disminución de esta práctica, éstos procesos se han incrementado. Objetivo. Evaluar la morbilidad infecciosa tanto gastrointestinal como respiratoria en lactantes amamantados. Material y métodos. Se realizó un estudio prospectivo, longitudinal que incluyó al 2 por ciento de lactantes y madres de Morelia, Mich. El muestreo fue aleatorio simple, lo que significó seleccionar 260 binomios. Los niños se alimentaron exclusivamente al seno materno hasta el año y con ablactación normada por UNICEF, se revisaron cada mes. Resultados. Se encontraron 12 niños con diarrea leve, 90 con infecciones respiratorias leves y 158 sanos; en 30 casos recibieron antibiótico por cinco días. No hubo defunciones. Un 29 por ciento fueron madres menores de 20 años, la mayoría primigestas, con escolaridad media, dedicadas al hogar y nivel socioeconómico medio bajo. Recomendaciones. Fomentar el amamantamiento hasta el año de edad, control sistemático de los niños en consulta, proscripción de leche industrializada en el primer año de vida y fortalecer al educación sexual

Factores de riesgo en enfermedades alérgicas / Risk factor in allergy diseases

El periodo posnatal inmediato representa para el niño una etapa de alto riesgo para su sensibilización. La expresión del fenotipo alérgico está determinado por las características genéticas, e influenciado por diversos factores, entre ellos la dieta materna (durante el embarazo y la lactancia) el mes de nacimiento, el régimen alimentario del lactante y las infecciones de las vías aéreas, además de otros factores adyuvantes, como el tabaquismo y la contaminación ambiental. La combinación de estos factores en contacto con el sistema inmune, aún inmaduro en el producto, puede propiciar un riesgo elevado de sensibilización y posterioremente manifestarse clínicamente.

Proteínas de la leche y su asociación con diabetes mellitus insulino-dependiente / Milk proteins and it association with insulin dependent diabetes mellitus

Cow`s milk has been implicated as a possible trigger of the autoinmune respose that destroys pancreatic beta cells in genetically susceptible host, thus causing diabetes mellitus. Studies in animals have suggested that bovine serum albumin, BSA, is the milk protein responsible, and an albumin peptide containing 17 amino acids, ABBOS, may be the reactive epitope. Antibodies to this peptide react with p69 a beta cell surface protein that may represent the target antigen for milk-induced beta-cell specific inmunity. The consumption of cow`s milk in Europe may support the hypothesis that cow`s milk may be a triggering factor for the development of type I diabetes. However, several epidemiological studies has not found significance correlation between the observed the importance of several enviromental factors in the devepment of type I diabetes with the objetive to establish a good prevention in susceptible subjects