Associations of plasma fibrinogen assays, C-reactive protein and interleukin-6 with previous myocardial infarction

Background: The association of plasma fibrinogen with myocardial infarction (MI) may (like that of C-reactive protein, CRP) be a marker of subclinical inflammation, mediated by cytokines such as interleukin-6 (IL-6). There are well- recognized discrepancies between commonly performed fibrinogen assays. Increased ratio of clottable fibrinogen to intact fibrinogen (measured by a recently developed immunoassay) has been proposed as a measure of hyperfunctional fibrinogen, and is elevated in acute MI.<br/> Objective: To compare the associations of intact fibrinogen and four routine fibrinogen assays (two von Clauss assays; one prothrombin-time derived; and one immunonephelometric) in a case-control study of previous MI. Patients/methods: Cases (n = 399) were recruited 3-9 months after their event; 413 controls were age- and sex-matched from the case-control study local population. Intact fibrinogen was measured in 50% of subjects. Results: All routine fibrinogen assays showed high intercorrelations (r = 0.82-0.93) and significant (P lt 0.0001) increased mean levels in cases vs. controls. These four routine assays correlated only moderately with intact fibrinogen (r = 0.45-0.62), while intact fibrinogen showed only a small, nonsignificant increase in cases vs. controls. Consequently, the ratio of each of the four routine assays to the intact fibrinogen assay was significantly higher (P lt 0.0003) in cases vs. controls. Each fibrinogen assay correlated with plasma levels of CRP and IL-6 (which were also elevated in cases vs. controls). Each routine fibrinogen assay remained significantly elevated in cases vs. controls after further adjustment for C-reactive protein and interleukin-6. Conclusions: These data provide evidence for acquired, increased hyperfunctional plasma fibrinogen in MI survivors, which is not associated with markers of inflammatory reactions. The causes and significance of these results remain to be established in prospective studies

Microbolometer spectrometer: applications and technology

Current Thermal Infra Red (7.14μm) multispectral imager instruments use cryogenically cooled Mercury Cadmium Telluride (MCT or HgCdTe) detectors. Now due to the increased performance of uncooled microbolometer arrays, the next generation of instruments can be designed without cryogenic cooling. TNO TPD has designed a spectrometer called the Micro Bolometer Spectrometer (MIBS), that is able to provide co-registered images in the 7 to 14 μm wavelength region with an acceptable NETD performance on the basis of currently available detectors. Apart from space based multispectral imaging, the concept can also be used for several other applications, for example, CO2 monitoring through the broader spectral response. The removal of the standard highpass filter of the bolometer detector allows imaging in both the 3 to 5 and 7 to 14 μm atmospheric windows at the same time in a co-registered fashion. Applications include forest fire detection, military reconnaissance and, wideband flame analysis (NOx detection in industrial ovens)