The use of bioprocess to convert low valued biomass or agroindustrial byproducts into high-value chemicals is an emerging area. However, laboratories usually use outdated analytical techniques to identify bioproducts, losing valuable information, such as the identification of unexpected compounds. In this work, we presented a successful systematic and modern analytical approach based on direct infusion mass spectrometry (DIMS) for an automated high-throughput screening of untargeted compounds from glycerin bioconversion process. We describe advantages of DIMS and its combined application with chemometrics towards an untargeted metabolomics approach to analyze several samples in a short time (11 samples per h). Three batches with 34 samples from the bioconversion of glycerin using several filamentous fungi strains were analyzed. Batch 347 was selected as promising, since high value chemicals, such as amide, phenolic and acid compounds, were identified. The platform presented was fast, robust, and versatile, then it could be applied to different bioprocesses.

OBJETIVO: Conhecer os fatores de risco para a doença por refluxo gastroesofágico (DRGE) em recém-nascidos de muito baixo peso com displasia broncopulmonar. MÉTODOS: Realizou-se um estudo caso-controle incluindo 23 casos e 23 controles com displasia broncopulmonar, sendo realizada investigação por monitorização prolongada do pH esofágico no período de janeiro de 2001 a outubro de 2005. Para cada caso, selecionou-se um controle, e foram comparados pela idade gestacional, peso ao nascimento, gênero, uso de corticóide pré-natal, tempo de ventilação assistida, tempo de oxigenoterapia, tempo de uso de sonda gástrica, uso de xantinas, idade pós-conceptual e peso durante a monitorização do pH esofágico. Realizou-se a análise por regressão logística múltipla para estabelecer o odds ratio (OR) com intervalo de confiança de 95% (IC95%). RESULTADOS: Os dois grupos (com e sem DRGE) não apresentaram diferenças significativas em relação às variáveis demográficas e de evolução pós-natal, uso de corticóide pré e pós-natal, bem como ao tempo de uso de cafeína, ventilação mecânica e oxigenoterapia. Entretanto, as variáveis intolerância alimentar (OR = 6,55; IC95% 1,05-40,8) e tempo de uso de sonda gástrica (OR = 1,67; IC95% 1,11-2,51) comportaram-se como fatores de risco para DRGE. A variável idade pós-conceptual ao exame de monitorização do pH (OR = 0,02; IC95% < 0,001-0,38) comportou-se como fator protetor para DRGE. CONCLUSÃO: Os dados obtidos permitem inferir que o tempo prolongado de uso de sonda gástrica e a intolerância alimentar aumentam a probabilidade para DRGE. Já a maior idade pós-conceptual ao exame diminui a chance para DRGE em prematuros com menos de 1.500 g com displasia broncopulmonar.

OBJECTIVE: To assess risk factors for gastroesophageal reflux disease (GERD) in very low birth weight infants with bronchopulmonary dysplasia. METHODS: A case-control study was carried out in 23 cases and 23 control subjects with bronchopulmonary dysplasia submitted to 24-hour esophageal pH monitoring between January 2001 and October 2005. Cases and controls were compared for gestational age, birth weight, gender, use of antenatal steroids, duration of assisted ventilation, duration of oxygen therapy, length of gastric tube use, administration of xanthines, postconceptual age, and weight at esophageal pH monitoring. Multiple logistic regression analysis was used to establish the odds ratio(OR) with a 95% confidence interval (95%CI). RESULTS: None of the groups (with and without GERD) showed statistically significant differences in terms of demographic variables and postnatal outcome, use of antenatal and postnatal corticosteroids, or in terms of caffeine use and duration of mechanical ventilation and oxygen therapy. However, feeding intolerance (OR = 6.55; 95%CI 1.05-40.8) and length of gastric tube use (OR = 1.67; 95%CI 1.11-2.51) turned out to be risk factors for GERD. Postconceptual age at the time of pH monitoring (OR = 0.02; 95%CI < 0.001-0.38) was regarded as a protective factor against GERD. CONCLUSION: The data obtained allow inferring that prolonged gastric tube use and feeding intolerance increase the risk for GERD. On the other hand, older postconceptual age at the time of pH monitoring reduces the risk for GERD in preterm infants with bronchopulmonary dysplasia weighing less than 1,500 g.