Actigraphy has been widely used in adults and children. In infants, validation of actigraphy has typically used a comparison with behaviorally determined sleep state classification rather than polysomnography (PSG). This study validated actigraphy against PSG for determining sleep and waking states in infants who were younger than 6 mo. Twenty-two healthy infants, 13 term and 9 preterm, were studied at three different matched postconceptional ages. Actigraph data were compared with PSG recordings in 1-min epochs. Agreement rate (AR), predictive value for sleep, predictive value for wake, sensitivity. and specificity were calculated and compared between activity thresholds and across ages with two-way ANOVA for repeated measures. Thirty-two validation studies were analyzed. Overall AR with PSG of 93.7 Ϯ 1.3 and 91.6 Ϯ 1.8 were obtained at 2-4 wk and 5-6 mo, respectively, at the low activity threshold setting, whereas the auto activity threshold gave the best agreement with PSG at 2-4 mo (AR 89.3 Ϯ 1.3%). Sensitivity values of 96.2 Ϯ 1.1% at 2-4 wk, 91.2 Ϯ 1.5% at 2-4 mo, and 94.0 Ϯ 1.9% were obtained at these same settings. There was no difference across ages in AR or sensitivity. PVW and specificity values were low in this study. We conclude that actigraphy is a valid method for monitoring sleep in infants who are younger than 6 mo. Newborn infants spend~70% of their time asleep, and maturation of sleep is one of the major developments that occur during the first year of life. Sleep-related problems are extremely common in the preschool years, affecting~30% of this age group (1). Indeed, sleep problems are the most common subject on which parents seek advice from health professionals in these preschool years. These problems can range from disrupted sleep patterns with frequent night awakenings to sleep deprivation. The long-term consequences of poor sleep patterns are known to be slow growth, behavioral problems, poor school performance, family disruption, and even child abuse (2). Most home-based studies on infant sleep patterns have relied in parental reports. However, studies that have used both subjective and objective measures have identified that parental reporting may underestimate night-time awakening (3). Actigraphy provides a useful tool that has advantages over other methods of sleep/wake assessment in that it provides a noninvasive, continuous assessment that can be used for prolonged periods of time in a variety of situations. The actigraph continuously records the occurrence of limb movements and then sums the number of movements for a given epoch length. Through the use of a specially developed algorithm, the motility levels can be computer scored into states of sleep or wake (4,5). The actigraph was first developed for use in adults; however, it has recently been used in children to distinguish between sleep and wakefulness and provides a reliable measure of sleep-wake organization and sleep quality (4). To date, only two studies have been conducted in infants to validate actigraphy against other...

Patients exposed to a surgical safety checklist experience better postoperative outcomes, but this could simply reflect wider quality of care in hospitals where checklist use is routine.

Neural adaptation following maximal strength training improves the ability to rapidly develop force. Unilateral strength training also leads to contralateral strength improvement, due to cross-over effects. However, adaptations in the rate of force development and peak force in the contralateral untrained arm after one-arm training have not been determined. Therefore, we aimed to detect contralateral effects of unilateral maximal strength training on rate of force development and peak force. Ten adult females enrolled in a 2-month strength training program focusing of maximal mobilization of force against near-maximal load in one arm, by attempting to move the given load as fast as possible. The other arm remained untrained. The training program did not induce any observable hypertrophy of any arms, as measured by anthropometry. Nevertheless, rate of force development improved in the trained arm during contractions against both submaximal and maximal loads by 40-60%. The untrained arm also improved rate of force development by the same magnitude. Peak force only improved during a maximal isometric contraction by 37% in the trained arm and 35% in the untrained arm. One repetition maximum improved by 79% in the trained arm and 9% in the untrained arm. Therefore, one-arm maximal strength training focusing on maximal mobilization of force increased rapid force development and one repetition maximal strength in the contralateral untrained arm. This suggests an increased central drive that also crosses over to the contralateral side.

The association of PGCC with UC and an overlap in immunoexpression suggests that PGCC represents an extreme form of UC de-differentiation.

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