La spiegazione scientifica: Aspetti storico-epistemologici e didattica. L’esempio della Chimica

In this paper we have analyzed the general characteristics of the scientific explanation, and of the chemical explanation in particular, and its relation with the science education. Starting with the deductivenomo logical model, which can be considered the standard model, we have shown that you cannot claim that this model of explanation can be gave in a unique form, in line with the methodological reductionism that could be called “radical”. The systemic view has allowed us to capture the specific object of study in the multiplicity of relations that it structure its and to inserting each specific scientific theory in the socioeconomic contextof its birth. The application, then, of the systemic view to the science education underlines the need of a deep change of both the scholastic and university education.In questo lavoro abbiamo analizzato i principali aspetti storico-epistemologici della spiegazione scientifica in generale, e della Chimica in particolare, e la loro relazione con la didattica. Abbiamo analizzato le caratteristiche generali della spiegazione scientifica, concentrandoci sul modello no mologico-deduttivo, che può venire considerato il modello standard. Abbiamo evidenziato che non è possibile sostenere che di tale modello si dà un’unica forma, in linea con un riduzionismo metodologico che potremmo definire “radicale”. La concezione sistemica ci ha consentito di cogliere lo specifico oggetto di studio nella molteplicità delle relazioni che lo strutturano e di inserire la singola teoria scientifica nel contesto socio/economico che l’ha vista nascere. L’applicazione, poi, dell’ottica sistemica alla didattica delle scienze evidenzia la necessità di un profondo cambiamento sia dell’insegnamento scolastico sia di quello universitario

Hepatic and intestinal biotransformation and transport of xenobiotics during pregnancy and lactation

The liver is the main place for phase II metabolism and transport of xenobiotics mediated by Mrp2, leading to elimination of conjugated metabolites into bile. In the gastrointestinal tract, phase II enzymes and Mrp2 are preferentially localized in the proximal region of the small intestine, particularly at the tip of the villus. In pregnant rats, conjugating enzymes (e.g. UGT and GST) and Mrp2-mediated transport of xenobiotics are decreased when compared to normal females, whereas these systems are preserved in small intestine, suggesting a complementary role for this tissue. After delivery, these same enzymes increase their expression and activity, being maximal during the last week of lactation. Mrp2 protein in liver also recovers and reaches the control level by the end of the lactation period. Post-partum rats exhibit a significant increase in development of the digestive tract in association with induction of phase II enzymes and Mrp2 expression and activity. Although the factors involved in regulation of protein expression may not be the same for conjugating enzymes and Mrp2 in the different experimental situations or tissues studied, their common localization and co-regulation provide evidence that they may work in cooperation. This is not surprising if we consider that most of the substrates for MRPs are the products that result from phase II reactions. Here, we provide a brief description of regulation of major phase II enzymes and Mrp2 during pregnancy and lactation, as particularly seen in the rat.Fil: Arana, Maite Rocío. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Fisiología Experimental (i); ArgentinaFil: Arias, Agostina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Fisiología Experimental (i); ArgentinaFil: Villanueva, Silvina Stella Maris. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Fisiología Experimental (i); ArgentinaFil: Mottino, Aldo Domingo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Fisiología Experimental (i); Argentin

Successful whole lung lavage in pulmonary alveolar proteinosis secondary to lysinuric protein intolerance: a case report

BACKGROUND: Pulmonary alveolar proteinosis (PAP) is a rare disease characterised by accumulation of lipoproteinaceous material within alveoli, occurring in three clinically distinct forms: congenital, acquired and secondary. Among the latter, lysinuric protein intolerance (LPI) is a rare genetic disorder caused by defective transport of cationic amino acids. Whole Lung Lavage (WLL) is currently the gold standard therapy for severe cases of PAP. CASE PRESENTATION: We describe the case of an Italian boy affected by LPI who, by the age of 10, developed digital clubbing and, by the age of 16, a mild restrictive functional impairment associated with a high-resolution computed tomography (HRCT) pattern consistent with pulmonary alveolar proteinosis. After careful assessment, he underwent WLL. CONCLUSION: Two years after WLL, the patient has no clinical, radiological or functional evidence of pulmonary disease recurrence, thus suggesting that WLL may be helpful in the treatment of PAP secondary to LPI