Number and function of circulating human antigen presenting cells regulated by sleep

STUDY OBJECTIVES: There is evidence that sleep facilitates the adaptive immune response to infectious agents and, thereby, supports immunologic memory. The effect might be attained by sleep-induced changes in the number and function of dendritic cells (DCs), which play a key role in the initiation of the immune response. This study aimed to dissociate effects of sleep and circadian rhythm on circulating numbers of DC precursors, ie, CD14+CD16- and CD14(dim)CD16+ monocytes, myeloid dendritic cell precursors (pre-mDC), and plasmacytoid dendritic cells (PDC) and on 2 key cytokines produced by these cells, ie, interleukin (IL)-12 and interferon (IFN)-alpha. DESIGN: In a within-subject cross-over design, human subjects were examined on 2 occasions, ie, during a normal sleep-wake cycle and during 24 hours of wakefulness. Blood was sampled every 1.5 hours during nighttime and every 3 hours during daytime. SETTING: Experiments took place under controlled laboratory conditions. PARTICIPANTS: Twenty-seven healthy men aged between 18 and 30 years. MEASUREMENTS AND RESULTS: Compared with wakefulness, sleep was associated with a striking increase in the number of pre-mDC producing IL-12, which is a main inducer of Th1 responses. In addition, sleep slightly decreased PDC and also T cell counts but did not affect IFN-alpha production by PDC. Sleep, however, substantially decreased numbers of CD14(dim)CD16+ monocytes, probably reflecting increased margination of the cells upon a sleep-related drop in catecholamine release. CONCLUSIONS: Our data identify pre-mDC producing IL-12 as a basic target of sleep that is most closely related to mature APC function and whereby sleep can effectively enhance adaptive immune responses.     

Physical Activity Patterns and Correlates of 9-Month-Old Chinese Infants in the Macau Population

Objectives Many obesity-related chronic diseases originate from unhealthy childhood habits. The aim of this study was to describe 9-month-old infants’ physical activity levels and patterns and to examine the correlates. Understanding these factors is necessary for improving the effectiveness of physical activity intervention programs for infants. Methods In total, 143 infant–mother dyads from Macau, SAR China, participated in this study. Physical activity (PA) was assessed by using the Actigraph GT3X+ accelerometer and the demographic variables were collected by questionnaires. Results The most important findings were that: (1) infants had more screen time during weekdays (p?=?.044); (2) infants and mothers were least active at 8 a.m. (both weekdays and weekends) in the morning and most active at 7 p.m. (weekdays) and 8 p.m. (weekends) in the evening; (3) infants’ PA levels significantly correlated with their mothers’ PA intensities during the weekends (r?=?.192, p?=?.036), especially the mothers’ lower intensities in the mornings and evenings; (4) maternal BMI predicted the PA levels of the 9-month-old infants’ (R²?=?.06, β?=?29.188, p?=?.009). Conclusions for Practice Physical activity promotion programs for infants should be time-specific starting from early infancy. This study was one of the first to examine 9-month-old infants’ PA levels, patterns and correlates. The results may be helpful in improving the effectiveness of future healthy lifestyle intervention programs for infants in Macau and in the region in general.     

Trends in epidemiology and patho-anatomical pattern of proximal humeral fractures

Purpose

Proximal humeral fractures are common and frequently associated with osteoporosis. Little is known about the association between the patho-anatomical fracture pattern of proximal humeral fractures and patient characteristics. The purpose of this six year longitudinal registry analysis of proximal humeral fractures was to study overall numbers, certain predefined pathoanatomical patterns and distribution compared with specific patient characteristics.

Methods

Data of patients treated between 2006 and 2011 in a country hospital that provides care >95 % of the city’s hospitalised patients with fractures was retrospectively reviewed. Data were analysed according to patient characteristics of age, gender, comorbidity, accompanying injuries and radiological analysis of pathoanatomical fracture patterns based on Neer and Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification.

Results

Eight hundred and fifteen proximal humeral fractures (67 % women/33 % men; mean age 66 years, range 19–99) were analysed. During the study period, an overall increase of 42.5 % was found: according to AO classification, 46 % were type A, 22 % type B and 32 % type C. Based on the Neer classification, 86 % were displaced, and 49 % were complex with more than three parts. Of complex fractures, 57 % were female patients >60 years. The number of complex fractures was five times higher in women >60 years than in men of the same age group.

Conclusions

An overall increase of inpatients with displaced proximal tibial fractures was documented. Interestingly, complex displaced proximal humeral fractures, especially in older women with comorbidities, accounted for the majority of cases. These results suggest that health-care planning and hospital-based therapeutic strategies should focus on this patient group.