In smooth muscle tissues, the relationship between muscle or cell length and active force can be modulated by altering the cell or tissue length during stimulation. Mechanisms for this mechanical plasticity were investigated by measuring muscle stiffness during isometric contractions in which contractile force was graded by changing stimulus intensity or muscle length. Stiffness was significantly higher in contracted than in resting muscles at comparable forces; however, the relationship between stiffness and force during force development was curvilinear and independent of muscle length and stimulus intensity. This suggests that muscle stiffness during force development reflects properties of cellular components other than cross bridges which contribute to the series elasticity only during activation. During the tonic phase of isometric contraction, muscle stiffness increased while force remained constant. A step decrease in the length of a contracted muscle resulted in a high level of stiffness relative to force during isometric force redevelopment following the length step. We propose that the arrangement of the cytoskeleton can adjust to changes in the conformation of resting smooth muscle cells but that the organization of the cytoskeleton becomes more fixed upon contractile activation and is modulated very slowly during a sustained contraction. This may provide a mechanism for optimizing force development to the physical conformation of the cell at the time of activation.

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Adherence to guidelines was high for one third of the recommendations that were measured but was very low for nearly half of the measures, pointing to specific needs for quality improvement. Guideline-concordant depression care appears to be linked to improved outcomes in primary care patients with depression.

This study compared two components of a cognitive-behavioural treatment for panic disorder. Thirty-eight individuals with panic disorder and agoraphobia were randomly assigned to (a) cognitive restructuring, interoceptive exposure (i.e. repeated exposure to feared bodily sensations) and in vivo exposure to agoraphobic situations; or (b) cognitive restructuring, breathing retraining and in vivo exposure to agoraphobic situations. Assessments were conducted at pre-treatment, post-treatment and six months later. The treatments were equally effective on many measures. However, treatment that included interoceptive exposure was more effective at post-treatment in terms of panic frequency, overall severity and functioning, and more effective at six-month follow-up in terms of panic frequency, phobic fears and general anxiety and functioning. Follow-up results were limited due to attrition.

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