Reference Standards for Cardiorespiratory Fitness Measured With Cardiopulmonary Exercise Testing Using Cycle Ergometry: Data From the Fitness Registry and the Importance of Exercise National Database (FRIEND) Registry

The importance of cardiorespiratory fitness (CRF) is well established. This report provides newly developed standards for CRF reference values derived from cardiopulmonary exercise testing (CPX) using cycle ergometry in the United States. Ten laboratories in the United States experienced in CPX administration with established quality control procedures contributed to the “Fitness Registry and the Importance of Exercise: A National Database” (FRIEND) Registry from April 2014 through May 2016. Data from 4494 maximal (respiratory exchange ratio, ≥1.1) cycle ergometer tests from men and women (20-79 years) from 27 states, without cardiovascular disease, were used to develop these references values. Percentiles of maximum oxygen consumption (VO_2max) for men and women were determined for each decade from age 20 years through age 79 years. Comparisons of VO_2max were made to reference data established with CPX data from treadmill data in the FRIEND Registry and previously published reports. As expected, there were significant differences between sex and age groups for VO_2max (P<.01). For cycle tests within the FRIEND Registry, the 50th percentile VO_2max of men and women aged 20 to 29 years declined from 41.9 and 31.0 mLO₂/kg/min to 19.5 and 14.8 mLO₂/kg/min for ages 70 to 79 years, respectively. The rate of decline in this cohort was approximately 10% per decade. The FRIEND Registry reference data will be useful in providing more accurate interpretations for the US population of CPX-measured VO_2max from exercise tests using cycle ergometry compared with previous approaches based on estimations of standard differences from treadmill testing reference values.     

Association of the tyrosine kinase LCK with phospholipase C-gamma 1 after stimulation of the T cell antigen receptor

Stimulation of the T cell antigen receptor (TCR) activates a protein tyrosine kinase and leads to the tyrosine phosphorylation of phosphoinositide-specific phospholipase C-gamma 1 (PLC gamma 1). The molecular interactions involved in this phosphorylation are not known. After stimulation of the TCR on Jurkat T cells, tyrosine-phosphorylated proteins of 36, 38, 58, and 63 kD coprecipitate with PLC gamma 1. An identical pattern of proteins precipitate with TrpE fusion proteins that contain the Src homology (SH) 2 domains of PLC gamma 1, indicating that these regions of PLC gamma 1 are responsible for binding. TCR stimulation leads to an association between the SH2 domains of PLC gamma 1 and a protein tyrosine kinase, which, by peptide mapping, is identical to p56lck. These studies establish that p56lck associates with PLC gamma 1 as a result of TCR stimulation of Jurkat cells, suggesting that p56lck plays a central role in coupling the TCR to the activation of PLC gamma 1.     

A fourth hominin skull from Dmanisi, Georgia

Newly discovered Homo remains, stone artifacts, and animal fossils from Dmanisi, Republic of Georgia, provide a basis for better understanding patterns of hominin evolution and behavior in Eurasia ca. 1.77 million years ago. Here we describe a fourth skull that is nearly complete, lacking all but one of its teeth at the time of death. Both the maxillae and the mandible exhibit extensive bone loss due to resorption. This individual is similar to others from the site but supplies information about variation in brain size and craniofacial anatomy within the Dmanisi paleodeme. Although this assemblage presents numerous primitive characters, the Dmanisi skulls are best accommodated within the species H. erectus. On anatomical grounds, it is argued that the relatively small-brained and lightly built Dmanisi hominins may be ancestral to African and Far Eastern branches of H. erectus showing more derived morphology.     

Air Pollution from Road Traffic and Systemic Inflammation in Adults: A Cross-Sectional Analysis in the European ESCAPE Project

Background

Exposure to particulate matter air pollution (PM) has been associated with cardiovascular diseases.

Objectives

In this study we evaluated whether annual exposure to ambient air pollution is associated with systemic inflammation, which is hypothesized to be an intermediate step to cardiovascular disease.

Methods

Six cohorts of adults from Central and Northern Europe were used in this cross-sectional study as part of the larger ESCAPE project (European Study of Cohorts for Air Pollution Effects). Data on levels of blood markers for systemic inflammation—high-sensitivity C-reactive protein (CRP) and fibrinogen—were available for 22,561 and 17,428 persons, respectively. Land use regression models were used to estimate cohort participants’ long-term exposure to various size fractions of PM, soot, and nitrogen oxides (NO_x). In addition, traffic intensity on the closest street and traffic load within 100 m from home were used as indicators of traffic air pollution exposure.

Results

Particulate air pollution was not associated with systemic inflammation. However, cohort participants living on a busy (> 10,000 vehicles/day) road had elevated CRP values (10.2%; 95% CI: 2.4, 18.8%, compared with persons living on a quiet residential street with < 1,000 vehicles/day). Annual NO_x concentration was also positively associated with levels of CRP (3.2%; 95% CI: 0.3, 6.1 per 20 μg/m³), but the effect estimate was more sensitive to model adjustments. For fibrinogen, no consistent associations were observed.

Conclusions

Living close to busy traffic was associated with increased CRP concentrations, a known risk factor for cardiovascular diseases. However, it remains unclear which specific air pollutants are responsible for the association.

Citation

Lanki T, Hampel R, Tiittanen P, Andrich S, Beelen R, Brunekreef B, Dratva J, De Faire U, Fuks KB, Hoffmann B, Imboden M, Jousilahti P, Koenig W, Mahabadi AA, Künzli N, Pedersen NL, Penell J, Pershagen G, Probst-Hensch NM, Schaffner E, Schindler C, Sugiri D, Swart WJ, Tsai MY, Turunen AW, Weinmayr G, Wolf K, Yli-Tuomi T, Peters A. 2015. Air pollution from road traffic and systemic inflammation in adults: a cross-sectional analysis in the European ESCAPE project. Environ Health Perspect 123:785–791; http://dx.doi.org/10.1289/ehp.1408224