Molecular and cellular contractile dysfunction of dystrophic muscle from young mice.

The purpose of this study was to determine whether contractile protein alterations are responsible for force deficits in young dystrophic muscle. Contractility of intact extensor digitorum longus muscles and permeabilized fibers from wild-type (wt), dystrophin-deficient (mdx), and dystrophin/utrophin-deficient (mdx:utrn-/-) mice aged 21 and 35 days was determined. Myosin structural dynamics were assessed by site-directed spin labeling and electron paramagnetic resonance spectroscopy. The principal finding was that force generation was depressed by approximately 20% in mdx muscles, but fiber Ca2+-activated force and myosin structure were not different from wt animals, suggesting that contractile proteins are not responsible for the force deficits in those muscles. For mdx:utrn-/- mice, muscle and fiber forces were approximately 40% lower than wt and the fraction of strong-binding myosin during contraction was reduced by 13%. These data indicate that contractile protein alterations, in addition to myosin dysfunction, cause force deficit in muscles from young mdx:utrn-/- mice. Elucidating the molecular mechanisms underlying muscle weakness at the onset of disease is important for designing treatment strategies.

Oral care and stroke units.

OBJECTIVE: To investigate oral care provision reported by senior nurses in stroke care settings in Scotland. BACKGROUND: Stroke can have adverse effects on oral care and health. Little is known about current oral care practices in stroke care settings. MATERIALS AND METHODS: We designed a postal survey to be completed by ward managers or senior nurses. After piloting, the survey was distributed to all 71 units in Scotland, identified as providing specialist care for patients in the acute or rehabilitation stages following stroke. Pre-notification and reminder letters were circulated. Responses were anonymous. RESULTS: All but one survey was completed and returned. Help from dental professionals was available to most units (64/70) mostly on request. Only a third of units received oral care training in the last year (23/ 70). The majority of this training was ward based (20/23). The use of oral care assessment tools and protocols was limited (16/70 and 15/70 units respectively). Not all units had access to toothbrushes, toothpaste or chlorhexidine. For patients unable to perform oral care independently, senior nurses expected the patients' teeth or dentures to be cleaned at least twice a day in 59 of 70 and 49 of 70 units respectively. CONCLUSION: The response rate was excellent and has provided a national overview of oral care provision for patients in stroke care settings. Access to staff training, assessments, protocols and oral hygiene material varied considerably. This information provides a valuable baseline from which to develop and evaluate the effectiveness of ward-based oral care interventions for stroke patients.