Validation of the Actiheart Monitor for the Measurement of Physical Activity

The Actiheart monitor uniquely allows simultaneous measurement of heart rate and movement counts. The purpose of this study was to establish validity evidence for the Actiheart monitor under laboratory and free-living conditions. A total of 34 college students (17 males and 17 females, age = 21.8 ± 3.6 years) participated in the study. In the laboratory environment, the participants completed three, 5 min bouts of treadmill walking and/or running at speeds of 3.2, 6.4, and 9.6 km/h. Outside the laboratory, participants were asked to perform free-living physical activity for 30 min. For validation, energy expenditure, movement counts, and heart rate measurements from the Actiheart monitor were compared with an AEI Moxus Metabolic Cart, Actigraph accelerometer, Polar heart rate monitor (HRM), and electrocardiogram (ECG), respectively. The Actiheart underestimated energy expenditure only at the highest workload in the laboratory environment compared with the metabolic cart (p = .009). Actiheart heart rate (HR) was similar to the HR measured by ECG at all workloads. Under free-living conditions, the Actiheart energy expenditure was highly correlated (r = .81) with the Actigraph energy expenditure with no significant differences (t(33) =.26; p = .80). Actiheart heart rate was also highly correlated with HR from the Polar HRM (r = .93), however, there was an overestimation of HR by the Actiheart monitor (t(33) = 3.00; p = .005) under free-living conditions. The Actiheart monitor appears to accurately measure physical activity under free-living conditions and at low and moderate intensities in the laboratory environment

Dried blood spots: Effects of less than optimal collection, shipping time, heat, and humidity

ObjectivesThis study investigates how factors related to collection, storage, transport time, and environmental conditions affect the quality and accuracy of analyses of dried blood spot (DBS) samples.MethodsData come from the 2016 Health and Retirement Study (HRS) DBS laboratory reports and the HRS merged with the National Climatic Data Center (NCDC) Global Historical Climate Network Daily (NCDC GHCN‐Daily) and the NCDC Local Climatological Data, by zip code. We ran regression models to examine the associations between assay values based on DBS for five analytes (total cholesterol, high‐density lipoprotein (HDL) cholesterol, glycosylated hemoglobin (HbA1c), C‐reactive protein (CRP), and cystatin C) and the characteristics of DBS cards and drops, shipping time, and temperature, and humidity at the time of collection.ResultsWe found cholesterol measures to be sensitive to many factors including small spots, shipping time, high temperature and humidity. Small spots in DBS cards are related to lower values across all analytes. Longer DBS transit time before freezing is associated with lower values of total and HDL cholesterol and cystatin C. Results were similar whether or not venous blood sample values were included in equations.ConclusionsSmall spots, long shipping time, and exposure to high temperature and humidity need to be avoided if possible. Quality of spots and cards and information on shipping time and conditions should be coded with the data to make adjustments in values when necessary. The different results across analytes indicate that results cannot be generalized to all DBS assays.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162768/2/ajhb23390_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162768/1/ajhb23390.pd

Surfactant protein D increases fusion of Mycobacterium tuberculosis- containing phagosomes with lysosomes in human macrophages

Lung surfactant protein D (SP-D) binds to Mycobacterium tuberculosis surface lipoarabinomannan and results in bacterial agglutination, reduced uptake, and inhibition of growth in human macrophages. Here we show that SP-D limits the intracellular growth of bacilli in macrophages by increasing phagosome-lysosome fusion but not by generating a respiratory burst

Regulation of DMD pathology by an ankyrin-encoded miRNA

<p>Abstract</p> <p>Background</p> <p>Duchenne muscular dystrophy (DMD) is an X-linked myopathy resulting from the production of a nonfunctional dystrophin protein. MicroRNA (miRNA) are small 21- to 24-nucleotide RNA that can regulate both individual genes and entire cell signaling pathways. Previously, we identified several mRNA, both muscle-enriched and inflammation-induced, that are dysregulated in the skeletal muscles of DMD patients. One particularly muscle-enriched miRNA, miR-486, is significantly downregulated in dystrophin-deficient mouse and human skeletal muscles. miR-486 is embedded within the <it>ANKYRIN1(ANK1) </it>gene locus, which is transcribed as either a long (erythroid-enriched) or a short (heart muscle- and skeletal muscle-enriched) isoform, depending on the cell and tissue types.</p> <p>Results</p> <p>Inhibition of miR-486 in normal muscle myoblasts results in inhibited migration and failure to repair a wound in primary myoblast cell cultures. Conversely, overexpression of miR-486 in primary myoblast cell cultures results in increased proliferation with no changes in cellular apoptosis. Using bioinformatics and miRNA reporter assays, we have identified platelet-derived growth factor receptor β, along with several other downstream targets of the phosphatase and tensin homolog deleted on chromosome 10/AKT (PTEN/AKT) pathway, as being modulated by miR-486. The generation of muscle-specific transgenic mice that overexpress miR-486 revealed that miR-486 alters the cell cycle kinetics of regenerated myofibers <it>in vivo</it>, as these mice had impaired muscle regeneration.</p> <p>Conclusions</p> <p>These studies demonstrate a link for miR-486 as a regulator of the PTEN/AKT pathway in dystrophin-deficient muscle and an important factor in the regulation of DMD muscle pathology.</p

The Toxicology Investigators Consortium 2020 Annual Report.

The Toxicology Investigators Consortium (ToxIC) Registry was established by the American College of Medical Toxicology in 2010. The registry collects data from participating sites with the agreement that all bedside and telehealth medical toxicology consultation will be entered. This eleventh annual report summarizes the Registry\u27s 2020 data and activity with its additional 6668 cases. Cases were identified for inclusion in this report by a query of the ToxIC database for any case entered from January 1 to December 31, 2020. Detailed data was collected from these cases and aggregated to provide information which included demographics, reason for medical toxicology evaluation, agent and agent class, clinical signs and symptoms, treatments and antidotes administered, mortality, and whether life support was withdrawn. Gender distribution included 50.6% cases in females, 48.4% in males, and 1.0% identifying as transgender. Non-opioid analgesics were the most commonly reported agent class, followed by opioid and antidepressant classes. Acetaminophen was once again the most common agent reported. There were 80 fatalities, comprising 1.2% of all registry cases. Major trends in demographics and exposure characteristics remained similar to past years\u27 reports. Sub-analyses were conducted to describe race and ethnicity demographics and exposures in the registry, telemedicine encounters, and cases related to the COVID-19 pandemic