A multistage controlled intervention to increase stair climbing at work: effectiveness and process evaluation.

BACKGROUND: Stair climbing helps to accumulate short bouts of physical activity throughout the day as a strategy for attaining recommended physical activity levels. There exists a need for effective long-term stair-climbing interventions that can be transferred to various worksite settings. The aims of this study were: 1) to evaluate short- and long-term effectiveness of a worksite stair-climbing intervention using an objective measurement of stair climbing and a controlled design; and 2) to perform a process evaluation of the intervention. METHODS: We performed a controlled before-and-after study. The study was conducted in two corporate buildings of the same company located in Paris (France), between September, 2013 and September, 2014. The status of either "intervention site" or "control site" was assigned by the investigators. Participants were on-site employees (intervention site: n = 783; control site: n = 545 at baseline). Two one-month intervention phases using signs (intervention phase 1) and enhancement of stairwell aesthetics (intervention phase 2) were performed. The main outcome was the change in stair climbing, measured with automatic counters and expressed in absolute counts/day/100 employees and percent change compared to baseline. Qualitative outcomes were used to describe the intervention process. RESULTS: Stair climbing significantly increased at the intervention site (+18.7%) but decreased at the control site (-13.3%) during the second intervention phase (difference between sites: +4.6 counts/day/100 employees, p < 0.001). After the intervention and over the long term, stair climbing returned to baseline levels at the intervention site, but a significant difference between sites was found (intervention site vs. control site: +2.9 counts/day/100 employees, p < 0.05). Some important facets of the intervention were implemented as intended but other aspects had to be adapted. The main difficulty reported by the company's staff members lay in matching the internal communications rules with critical intervention criteria. The program was maintained at the setting level after the end of the study. CONCLUSIONS: This study shows a successful stair-climbing intervention at the worksite. The main barriers to adoption and implementation were related to location and visibility of posters. Process evaluation was useful in identifying these barriers throughout the study, and in finding appropriate solutions.

Stair-use interventions in worksites and public settings - a systematic review of effectiveness and external validity.

OBJECTIVE: We performed a literature review with the main aims to propose an updated overview of the effectiveness of stair-use interventions and to determine the most effective type of intervention. METHODS: We systematically searched stair-use interventions performed in worksites or public settings, published up to mid 2013. We used a harvest plot approach to visualize the findings in addition to a quantitative synthesis. We also assessed external validity using the Reach, Efficacy, Adoption, Implementation, Maintenance (RE-AIM) framework. RESULTS: Of 8571 articles identified, 50 were included. In worksites (25 studies) and public settings (35 studies), an increase in stair climbing was found during the intervention period in 64% and 76% of studies, respectively. Combining motivational and directional signs in worksites or conducting a second intervention phase in public settings increased stair climbing in 83% and 86% of studies, respectively. Elements of external validity were overall largely under-reported. CONCLUSION: There is evidence that stair-use interventions are effective to increase stair climbing in public settings, but evidence of such effect is limited in worksites. Issues regarding the best sequencing of interventions or the potential importance of environmental interventions should be addressed in future studies. Process evaluation should be an integral part of interventions.

A novel murine model of rhinoscleroma identifies Mikulicz cells, the disease signature, as IL-10 dependent derivatives of inflammatory monocytes.

Rhinoscleroma is a human specific chronic disease characterized by the formation of granuloma in the airways, caused by the bacterium Klebsiella pneumoniae subspecies rhinoscleromatis, a species very closely related to K. pneumoniae subspecies pneumoniae. It is characterized by the appearance of specific foamy macrophages called Mikulicz cells. However, very little is known about the pathophysiological processes underlying rhinoscleroma. Herein, we characterized a murine model recapitulating the formation of Mikulicz cells in lungs and identified them as atypical inflammatory monocytes specifically recruited from the bone marrow upon K. rhinoscleromatis infection in a CCR2-independent manner. While K. pneumoniae and K. rhinoscleromatis infections induced a classical inflammatory reaction, K. rhinoscleromatis infection was characterized by a strong production of IL-10 concomitant to the appearance of Mikulicz cells. Strikingly, in the absence of IL-10, very few Mikulicz cells were observed, confirming a crucial role of IL-10 in the establishment of a proper environment leading to the maturation of these atypical monocytes. This is the first characterization of the environment leading to Mikulicz cells maturation and their identification as inflammatory monocytes.

Immature hematopoietic stem cells undergo maturation in the fetal liver.

Hematopoietic stem cells (HSCs), which are defined by their capacity to reconstitute adult conventional mice, are first found in the dorsal aorta after 10.5 days post coitus (dpc) and in the fetal liver at 11 dpc. However, lympho-myeloid hematopoietic progenitors are detected in the dorsal aorta from 9 dpc, raising the issue of their role in establishing adult hematopoiesis. Here, we show that these progenitors are endowed with long-term reconstitution capacity, but only engraft natural killer (NK)-deficient Rag2γc(-/-) mice. This novel population, called here immature HSCs, evolves in culture with thrombopoietin and stromal cells, into HSCs, defined by acquisition of CD45 and MHC-1 expression and by the capacity to reconstitute NK-competent mice. This evolution occurs during ontogeny, as early colonization of fetal liver by immature HSCs precedes that of HSCs. Moreover, organ culture experiments show that immature HSCs acquire, in this environment, the features of HSCs.

Are hematopoietic stem cells generated in the placenta?

In this issue of Cell Stem Cell, the origin of multipotent hematopoietic cells present in the placenta has been assessed in Ncx1(-/-) embryos lacking a functional heart and circulation. Rhodes and colleagues (Rhodes et al., 2008) found lymphoid progenitors in the placenta, as well as in dorsal aorta and yolk sac and vitelline vessels, indicating that they arose in situ.

Expression of Pitx2 in stromal cells is required for normal hematopoiesis.

Although the expression of Pitx2, a bicoid family homeodomain transcription factor, is highly regulated during hematopoiesis, its function during this process was not documented; we thus studied hematopoiesis in Pitx2-null mice. We found that Pitx2(-/-) embryos display hypoplastic livers with reduced numbers of hematopoietic cells, but these cells had normal hematopoietic potential, as evidenced by colony-forming assays, immature progenitor cell assays, and long-term repopulation assays. Because the microenvironment is also crucial to the development of normal hematopoiesis, we established Pitx2(-/-) and Pitx2(+/+) stromas from fetal liver and studied their hematopoietic supportive capacity. We showed that the frequency of cobblestone area-forming cells was 4-fold decreased when using Pitx2(-/-) stromal cells compared with Pitx2(+/+) stromal cells, whatever the Pitx2 genotype of hematopoietic cells tested in this assay. This defect was rescued by expression of Pitx2 into Pitx2(-/-) fetal liver stromal cells, demonstrating a major and direct role of Pitx2 in the hematopoietic supportive capacity of fetal liver stroma. Finally, we showed a reduced capacity of MS5 stromal cells expressing Pitx2 RNAi to support human hematopoiesis. Altogether these data showed that Pitx2 has major functions in the hematopoietic supportive capacity of fetal liver and adult bone marrow stromal cells.