Bronchopulmonary dysplasia is a leading cause of mortality and morbidity in preterm infants despite improved treatment modalities. Pentoxifylline, a phosphodiesterase inhibitor, inhibits multiple processes that lead to neonatal hyperoxic lung injury, including inflammation, coagulation, and edema. Using a preterm rat model, we investigated the effects of pentoxifylline on hyperoxia-induced lung injury and survival. Preterm rat pups were exposed to 100% oxygen and injected subcutaneously with 0.9% saline or 75 mg/kg pentoxifylline twice a day. On day 10, lung tissue was harvested for histology, fibrin deposition, and mRNA expression, and bronchoalveolar lavage fluid was collected for total protein concentration. Pentoxifylline treatment increased mean survival by 3 days (P = 0.0018) and reduced fibrin deposition by 66% (P < 0.001) in lung homogenates compared with untreated hyperoxia-exposed controls. Monocyte chemoattractant protein-1 expression in lung homogenates was decreased, but the expressions of TNF-alpha, IL-6, matrix metalloproteinase-12, tissue factor, and plasminogen activator inhibitor-1 were similar in both groups. Total protein concentration in bronchoalveolar lavage fluid was decreased by 33% (P = 0.029) in the pentoxifylline group. Pentoxifylline treatment attenuates alveolar fibrin deposition and prolongs survival in preterm rat pups with neonatal hyperoxic lung injury, probably by reducing capillary-alveolar protein leakage.

No abstract

In biological research, generic questions that are derived from perspectives (ways of looking at and thinking about life processes) help in generating specific questions. In this study, we used perspective-based generic questions as scaffolds to support student teachers in increasing the quality and quantity of their questions about biological topics. Fifteen student biology teachers were given an intervention to individually generate, in 15 min, as many questions as possible that they might ask in class about standards from the national syllabus for biology on a particular biological topic, first without using, and then using a set of perspective-based generic questions. The results of this study show that, using perspective-based generic questions, student teachers generated significantly more and higher quality questions. The formulated questions can be applied in two different contexts: during practicum, when student teachers actually teach biology, or when they plan future lessons, as the basis of challenging tasks or assignments, with the aim of getting students interested in finding the answers.