Observations of cold-induced vasodilation in persons with spinal cord injuries.

STUDY DESIGN: Acute experimental study. OBJECTIVES: Cold-induced vasodilation is a local mechanism of protection against frostbite in non-injured persons. We assessed whether an increase in skin blood flow (SkBF) during local cooling (LC) was observed in individuals with spinal cord injuries (SCIs) and if the response patterns differed between region levels or sites. SETTING: Laboratory of Wakayama Medical University and the affiliated clinics, Japan. METHODS: A local cooler device (diameter 4 cm) was placed on the chest (sensate) and right thigh (non-sensate) in persons with cervical (SCIC; n = 9) and thoracolumbar SCIs (SCITL; n = 9). After the surface temperature under the device was controlled at 33 °C for 10 min (baseline), LC (-0.045 °C/s) was applied and the skin temperature was maintained at 15 and 8 °C for 15 min of each stage. SkBF (laser Doppler flowmetry) was monitored using a 1-mm needle-type probe inserted into its center. RESULTS: The percent change in SkBF (%ΔSkBF) on the chest remained unchanged until the end of 15 °C stage; thereafter, it increased to a level at least 70% greater than the baseline during the 8 °C stage in both groups. The %ΔSkBF on the thigh in both SCIC and SCITL notably increased from 8 and 6 min respectively, during the 8°C stage, compared to 1 min before the stage; however, it did not exceed the baseline level. CONCLUSIONS: An increase in SkBF during LC was observed both in the sensate and non-sensate areas in SCIs, although the magnitude was larger in the sensate area.

Weekdays' sleeping condition and its influence on occurrence of general malaise in Japanese children aged 10 to 12 years.

The present study aimed to elucidate weekdays' sleeping condition and its influence on occurrence of general malaise in children. A total of 761 Japanese children aged 10 to 12 years were surveyed regarding their weekdays' waking time and bedtime and general malaise using a self-administered questionnaire. As the result of hierarchical cluster analysis on the sleep condition, the participants were classified into three clusters. Sleep duration was significantly longer in cluster 1 (9.35 ± 0.52 h) than in clusters 2 (7.83 ± 0.77 h) and 3 (9.02 ± 0.30 h) and significantly longer in cluster 3 than in cluster 2. Waking time was significantly later in cluster 3 (7:01 ± 0:12) than in clusters 1 (6:22 ± 0:31) and 2 (6:24 ± 0:33, p < 0.001). Bedtime was significantly later in cluster 2 (22:34 ± 0:47) than in clusters 3 (21:59 ± 0:19) and 1 (21:01 ± 0:22) and significantly later in cluster 3 than in cluster 1. There were significantly more subjects in cluster 2 than in clusters 1 and 3 who responded "nearly every day" or "occasionally" to the five of seven questionnaires related to general malaise. The current results indicate that in Japanese children aged 10 to 12 years, (1) sleeping condition of weekdays are classified into three clusters with different mean values for each of sleep duration, bedtime, and waking time, and (2) the occurrence of general malaise may be enhanced in individuals whose sleep duration is less than 8 h.