Mindfulness-based stress reduction alters brain activity for breast cancer survivors with chronic neuropathic pain: preliminary evidence from resting-state fMRI.

PURPOSE: Breast cancer continues to be the most commonly diagnosed cancer among Canadian women, with as many as 25-60% of women suffering from chronic neuropathic pain (CNP) as a pervasive consequence of treatment. While pharmacological interventions have shown limited efficacy for the management of CNP to date, psychological interventions, such as mindfulness-based stress reduction (MBSR), may be a promising alterative for improving pain-related problems. The purpose of this study was to use brain imaging methods to investigate this potential. METHODS: Resting-state fMRI was used in female breast cancer survivors with CNP before and after an 8-week MBSR course (n = 13) and compared with a waitlist control group (n = 10). RESULTS: Focusing on the default mode network, the most significant results show greater posterior cingulate connectivity with medial prefrontal regions post-MBSR intervention. Moreover, this change in connectivity correlated with reduced pain severity for the MBSR group. CONCLUSIONS: These results provide empirical evidence of a change in the brain following MBSR intervention associated with changes in the subjective experience of pain. IMPLICATIONS FOR CANCER SURVIVORS: This study gives hope for a non-invasive method of easing the struggle of CNP in women following breast cancer treatment.

A model morphology of the pulmonary acinus.

A variation of a mathematical model of the structure of a pulmonary ventilatory unit is used to generate its internal ductal tree and associated alveolar architecture. The model unit comprises a space-filling block of regular polyhedra; ducts and alveoli were formed by opening specific common faces between polyhedra. The model employs a physically reasonable optimization strategy of maximizing gas exchange while minimizing the mean transit time to ventilate the ventilatory unit (assumed to be proportional to the mean path length) in order to create the ductal tree. The sensitivity of the global architecture to the competitive optimization parameters used and the tree structure are compared with independently published measurements. The study concludes that it is possible to model the detailed architecture of a unit using a simple space-invariant uniform modular structure for both alveoli and ductal parts. The close similarity between model and experimental measurement strongly suggests that the optimization used to create the unit is a likely one from a functional biological standpoint. The insensitivity of the architecture to the competition between the optimization parameters supports the belief that it is not important to consider the detailed measured size distribution of alveoli when considering how the large structure of the ventilatory unit is built up.

Modelling impact-initiated wave transmission through lung parenchyma in relation to the aetiology of exercise-induced pulmonary haemorrhage.

Recently we proposed that exercise-induced pulmonary haemorrhage (EIPH) results from locomotory-impact-induced trauma by impact of the scapula on the chest wall during footfall and the consequent transmission of waves through the lung. A computational model has been developed to demonstrate that wave amplification and focusing occur in the dorsocaudal tip of the lung for waves originating on the anterior subscapular surface. The propagation of an acoustic wave was investigated in a simplified 2-dimensional representation of a vertical anterio-dorsal section of horse lung. It was demonstrated that a complicated pattern of waves is transmitted from the scapula to the dorsal region. Wave motion was characterised using the instantaneous rate of change of pressure with time (dp/dt) which is associated with lung injury. Due to wave reflection and focusing, dp/dt is transiently very high on the spinal and diaphragmatic lung walls, particularly in the vicinity of the dorsal tip. The model therefore predicts that lung injury may occur in the region in which EIPH is reported to originate.