In vivo and in vitro protein digestibility of formulated feeds for Artemesia longinaris (Crustacea, Penaeidae)

This study was undertaken to determine the in vivo crude protein apparent digestibility in the prawn Artemesia longinaris, using feeds with 0.25 percent of chromic oxide and animal (fish meal, meat and bone meal and squid protein concentrate) and plant (soybean meal) ingredients. Three replicate groups of prawn were fed and the feces were collected. The rate of protein hydrolysis was measured in vitro using midgut gland enzyme extract from the prawns fed the respective feeds and was compared with those found with enzyme extract of wild prawn. The in vivo apparent digestibility coefficients showed significant differences among the feeds (P<0.05). Fish meal feed presented the highest digestibility (92 percent); intermediate digestibility (83 percent) was found for meat and bone meal feed, and the less digestible feed (63 percent) was that containing soybean meal and squid proteins concentrate. No significant differences in the in vitro protein digestibility were found among the experimental feeds. The results indicated the limitation of in vitro enzyme assays and that it should be complemented by in vivo studies.

O objetivo do presente trabalho foi determinar a digestibilidade aparente in vivo da proteína bruta de ingredientes de origem animal (farinhas de peixe, osso e carne e concentrado de proteína de lula) e ingredientes vegetais (farinha de soja) em camarões Artemesia longinaris utilizando rações contendo 0,25 por cento de óxido de cromo. Três grupos de camarões, utilizados como replicatas, foram alimentados e as fezes coletadas. A velocidade de hidrólise da proteína de cada ração foi medida in vitro utilizando extrato enzimático da glândula do intestino médio dos camarões alimentados com a ração correspondente e foi comparado com aqueles obtidos com o extrato enzimático de camarões selvagens. Os coeficientes de digestibilidade aparente in vivo mostraram diferenças significativas entre as rações testadas (P<0,05). A farinha de peixe apresentou a maior digestibilidade (92 por cento), enquanto valores intermediários de digestibilidade (83 por cento) foram encontrados para a farinha de carne e ossos. A ração contendo farinha de soja e concentrado de proteína de lula resultou em menor digestibilidade (63 por cento). Não houve diferença significativa entre os valores de digestibilidade in vitro para as rações testadas. Estes resultados indicam a limitação inerente dos ensaios enzimáticos in vitro, os quais poderiam ser complementados com estudos in vivo.

Biomarcadores de exposición a tabaco ambiental en Argentina / Biomarkers of environmental tobacco smoke (ETS) exposure in Argentine

Health effects of smoking have been studied intensely and there is substantial evidence on the harmful consequences for health that produces. In the last 20 years the effect of environmental tobacco smoke has been studied and researchers as governmentalagencies have concluded that involuntary smoking is one of the causes of lung cancer and cardiovascular illness in adults and of adverse consequences, like the syndrome of sudden death of the nursing, asthma, bronchitis and pneumonia in small children (1,2). Epidemiological questionnaires have been the usual method to determine exposition to environmental tobacco,but they present bias and low sensibility that can lead to misinterpretations of associations between exposition and illness (3,4). Cotinine, a metabolite from nicotine with a relatively short half life in plasma (about 20-30 hours), is useful as a biomarker for categorization and verification of a recent exposition (5). The goal of this work was to determine the level of exposition to environmentaltobacco smoke in a group of adolescents of the city of Mar del Plata, Argentina.