Exploring objective approaches to measuring human physical activity in human-animal interaction research

A dog owner (female, 37 years) wore an activPALTM monitor [2] for 7 days, and completed a diary reporting timing of walking outdoors (with/without the dog). ActivPALTM monitors classify acceleration into periods of sitting, standing or walking allowing outcome measures relating to the quantity, quality and patterning of PA, e.g. walking at a pace suitable for health. Walking events (continuous periods of walking) were coded into activity categories based on diary information. Duration of walking, number of steps, and mean cadence of walking events were compared across categories. ResultsOn average the participant walked 2.3 hours/day, taking 12,118 steps/day, and walked the dog once/day. Mean walking event duration (72 vs. 33 s) and steps taken (127 vs. 54) were consistently higher when walking outdoors with the dog than without the dog. Cadence, however, was only marginally higher during dog walking (87 vs. 82 steps/min).ConclusionClear differences were demonstrated in the accumulation of outdoor walking with and without the dog. This level of detail in the pattern of walking allows interpretation of whether the walking could be health enhancing. Furthermore, this methodology will allow differences in health enhancing PA between dog owners and non-dog owners to be investigated in future studies.References[1] Christian HE, Westgarth C, Bauman A, Richards EA, Rhodes R, Evenson KR, Mayer JA, Thorpe RJ Jr. Dog ownership and physical activity: a review of the evidence. Journal of Physical Activity and Health, In Press[2] Grant PM, Dall PM, Mitchell SL, Granat MH. Activity monitor accuracy in measuring step number and cadence in community-dwelling older adults. Journal of Aging and Physical Activity 2008; 16(2):201-14.</p

DataSheet_1_Peripheral blood marker of residual acute leukemia after hematopoietic cell transplantation using multi-plex digital droplet PCR.pdf

BackgroundRelapse remains the primary cause of death after hematopoietic cell transplantation (HCT) for acute leukemia. The ability to identify minimal/measurable residual disease (MRD) via the blood could identify patients earlier when immunologic interventions may be more successful. We evaluated a new test that could quantify blood tumor mRNA as leukemia MRD surveillance using droplet digital PCR (ddPCR).MethodsThe multiplex ddPCR assay was developed using tumor cell lines positive for the tumor associated antigens (TAA: WT1, PRAME, BIRC5), with homeostatic ABL1. On IRB-approved protocols, RNA was isolated from mononuclear cells from acute leukemia patients after HCT (n = 31 subjects; n = 91 specimens) and healthy donors (n = 20). ddPCR simultaneously quantitated mRNA expression of WT1, PRAME, BIRC5, and ABL1 and the TAA/ABL1 blood ratio was measured in patients with and without active leukemia after HCT.ResultsTumor cell lines confirmed quantitation of TAAs. In patients with active acute leukemia after HCT (MRD+ or relapse; n=19), the blood levels of WT1/ABL1, PRAME/ABL1, and BIRC5/ABL1 exceeded healthy donors (p<0.0001, p=0.0286, and p=0.0064 respectively). Active disease status was associated with TAA positivity (1+ TAA vs 0 TAA) with an odds ratio=10.67, (p=0.0070, 95% confidence interval 1.91 – 59.62). The area under the curve is 0.7544. Changes in ddPCR correlated with disease response captured on standard of care tests, accurately denoting positive or negative disease burden in 15/16 (95%). Of patients with MRD+ or relapsed leukemia after HCT, 84% were positive for at least one TAA/ABL1 in the peripheral blood. In summary, we have developed a new method for blood MRD monitoring of leukemia after HCT and present preliminary data that the TAA/ABL1 ratio may may serve as a novel surrogate biomarker for relapse of acute leukemia after HCT.</p