Efficacy of pirfenidone in patients with idiopathic pulmonary fibrosis with more preserved lung function.

This post hoc analysis examined the differences in idiopathic pulmonary fibrosis disease progression and the effects of pirfenidone in patients stratified by more preserved versus less preserved baseline lung function status using forced vital capacity (FVC) or GAP (gender, age and physiology) index stage.Efficacy outcomes, i.e. FVC, 6-min walking distance (6MWD) and dyspnoea (University of California San Diego Shortness of Breath Questionnaire (UCSD SOBQ)), were analysed at 12 months in patients randomised to pirfenidone 2403 mg·day(-1) or placebo in the pooled phase 3 CAPACITY/ASCEND population (n=1247), with subgroups stratified by baseline FVC ≥80% versus <80% or GAP stage I versus II-III. Treatment-by-subgroup interaction was tested based on a rank ANCOVA model; factors in the model included study, region, treatment, subgroup and treatment-by-subgroup interaction term.Patients with both more preserved (FVC ≥80% or GAP stage I) and less preserved (FVC <80% or GAP stage II-III) lung function at baseline demonstrated clinically significant disease progression at 12 months in terms of categorical decline in FVC, 6MWD and UCSD SOBQ. The magnitude of pirfenidone treatment effect was comparable between subgroups, regardless of whether lung function was classified using FVC or GAP index stage.These findings support the initiation of treatment with pirfenidone, irrespective of stage of baseline lung function in this patient population.

Goal-oriented searching mediated by ventral hippocampus early in trial-and-error learning.

Most behavioral learning in biology is trial and error, but how these learning processes are influenced by individual brain systems is poorly understood. Here we show that ventral-to-dorsal hippocampal subdivisions have specific and sequential functions in trial-and-error maze navigation, with ventral hippocampus (vH) mediating early task-specific goal-oriented searching. Although performance and strategy deployment progressed continuously at the population level, individual mice showed discrete learning phases, each characterized by particular search habits. Transitions in learning phases reflected feedforward inhibitory connectivity (FFI) growth occurring sequentially in ventral, then intermediate, then dorsal hippocampal subdivisions. FFI growth at vH occurred abruptly upon behavioral learning of goal-task relationships. vH lesions or the absence of vH FFI growth delayed early learning and disrupted performance consistency. Intermediate hippocampus lesions impaired intermediate place learning, whereas dorsal hippocampus lesions specifically disrupted late spatial learning. Trial-and-error navigational learning processes in naive mice thus involve a stereotype sequence of increasingly precise subtasks learned through distinct hippocampal subdivisions. Because of its unique connectivity, vH may relate specific goals to internal states in learning under healthy and pathological conditions.

Inducible and neuron-specific gene expression in the adult mouse brain with the rtTA2S-M2 system.

To achieve inducible and reversible gene expression in the adult mouse brain, we exploited an improved version of the tetracycline-controlled transactivator-based system (rtTA2(S)-M2, rtTA2 hereafter) and combined it with the forebrain-specific CaMKIIalpha promoter. Several independent lines of transgenic mice carrying the CaMKIIalpha promoter-rtTA2 gene were generated and examined for anatomical profile, doxycycline (dox)-dependence, time course, and reversibility of gene expression using several lacZ reporter lines. In two independent rtTA2-expressing lines, dox-treatment in the diet induced lacZ reporter expression in neurons of several forebrain structures including cortex, striatum, hippocampus, amygdala, and olfactory bulb. Gene expression was dose-dependent and was fully reversible. Further, a similar pattern of expression was obtained in three independent reporter lines, indicating the consistency of gene expression. Transgene expression could also be activated in the developing brain (P0) by dox-treatment of gestating females. These new rtTA2-expressing mice allowing inducible and reversible gene expression in the adult or developing forebrain represent useful models for future genetic studies of brain functions.