Non-invasive gene-expression-based detection of well-developed collateral function in individuals with and without coronary artery disease.

BACKGROUND: In patients with coronary artery disease (CAD), a well grown collateral circulation has been shown to be important. The aim of this prospective study using peripheral blood monocytes was to identify marker genes for an extensively grown coronary collateral circulation. METHODS: Collateral flow index (CFI) was obtained invasively by angioplasty pressure sensor guidewire in 160 individuals (110 patients with CAD, and 50 individuals without CAD). RNA was extracted from monocytes followed by microarray-based gene-expression analysis. 76 selected genes were analysed by real-time polymerase chain reaction (PCR). A receiver operating characteristics analysis based on differential gene expression was then performed to separate individuals with poor (CFI<0.21) and well-developed collaterals (CFI>or=0.21) Thereafter, the influence of the chemokine MCP-1 on the expression of six selected genes was tested by PCR. RESULTS: The expression of 203 genes significantly correlated with CFI (p = 0.000002-0.00267) in patients with CAD and 56 genes in individuals without CAD (p = 00079-0.0430). Biological pathway analysis revealed 76 of those genes belonging to four different pathways: angiogenesis, integrin-, platelet-derived growth factor-, and transforming growth factor beta-signalling. Three genes in each subgroup differentiated with high specificity among individuals with low and high CFI (>or=0.21). Two out of these genes showed pronounced differential expression between the two groups after cell stimulation with MCP-1. CONCLUSIONS: Genetic factors play a role in the formation and the preformation of the coronary collateral circulation. Gene expression analysis in peripheral blood monocytes can be used for non-invasive differentiation between individuals with poorly and with well grown collaterals. MCP-1 can influence the arteriogenic potential of monocytes.

Anthropogenic warming of Earth's climate system.

We compared the temporal variability of the heat content of the world ocean, of the global atmosphere, and of components of Earth's cryosphere during the latter half of the 20th century. Each component has increased its heat content (the atmosphere and the ocean) or exhibited melting (the cryosphere). The estimated increase of observed global ocean heat content (over the depth range from 0 to 3000 meters) between the 1950s and 1990s is at least one order of magnitude larger than the increase in heat content of any other component. Simulation results using an atmosphere-ocean general circulation model that includes estimates of the radiative effects of observed temporal variations in greenhouse gases, sulfate aerosols, solar irradiance, and volcanic aerosols over the past century agree with our observation-based estimate of the increase in ocean heat content. The results we present suggest that the observed increase in ocean heat content may largely be due to the increase of anthropogenic gases in Earth's atmosphere.

Interannual variability of temperature at a depth of 125 meters in the north atlantic ocean.

Analyses of historical ocean temperature data at a depth of 125 meters in the North Atlantic Ocean indicate that from 1950 to 1990 the subtropical and subarctic gyres exhibited linear trends that were opposite in phase. In addition, multivariate analyses of yearly mean temperature anomaly fields between 20 degrees N and 70 degrees N in the North Atlantic show a characteristic space-time temperature oscillation from 1947 to 1990. A quasidecadal oscillation, first identified at Ocean Weather Station C, is part of a basin-wide feature. Gyre and basin-scale variations such as these provide the observational basis for climate diagnostic and modeling studies.