Brachial-ankle pulse wave velocity compared with mean arterial pressure and pulse pressure in risk stratification in a Chinese population.

BACKGROUND: Brachial-ankle pulse wave velocity (baPWV) can be easily measured in an observer-independent way, but lacks robust population-based validation in terms of fatal combined with nonfatal outcomes. METHOD: To address this issue, we studied 4251 Chinese randomly recruited Gaoyou County (54.1% women; mean age, 52.1). RESULTS: In the whole study population, mean values were 102.4 mmHg for mean arterial pressure (MAP), 51.1 mmHg for pulse pressure, and 14.8 m/s for baPWV. Over 4.4 years (median), 74 participants experienced a fatal or nonfatal cardiovascular event and 44 a stroke. In multivariable-adjusted Cox regression, standardized hazard ratios expressing the risk of a composite cardiovascular endpoint were 1.77 (95% confidence interval, 1.43-2.20), 1.37 (1.14-1.64) and 1.50 (1.26-1.78) for MAP, PP and baPWV, respectively; the corresponding hazard ratios for stroke were 1.82 (1.39-2.38), 1.39 (1.12-1.74) and 1.53 (1.25-1.89). baPWV did not add to the prediction of cardiovascular events or stroke by MAP (hazard ratios for baPWV, 1.25 and 1.27, respectively; P ≥ 0.053) but refined models including PP (hazard ratios, 1.42 and 1.45; P ≤ 0.0033). The optimized baPWV threshold, obtained by maximizing Youden's index (16.7 m/s), increased the integrated discrimination improvement over and beyond MAP (+1.27%; P = 0.021) and PP (+1.37%; P = 0.038) for the cardiovascular outcome, but not stroke, and increased the net reclassification improvement for both endpoints (≥42.2%; P ≤ 0.004). CONCLUSION: With fatal and nonfatal cardiovascular and cerebrovascular endpoints as outcome, baPWV marginally increases risk stratification over and beyond MAP, but is a better predictor than PP. A threshold of 16.7 m/s might be used in Chinese populations.

Synchrotron radiation (SR) diffraction enhanced imaging (DEI) of chronic glomerulonephritis (CGN) mode.

OBJECTIVE: The aim of this study is to investigate microstructural changes in chronic glomerulonephritis (CGN) rabbit model under diffraction enhanced imaging (DEI) technology of synchrotron radiation (SR). MATERIALS AND METHODS: The chronic glomerulonephritis (CGN) models were obtained within two months after 5 New Zealand white rabbits were treated with doxorubicin hydrochloride. Blood exams, urine tests and kidney histological studies were carried out after the 5 rabbits were humanely sacrificed by hyperanesthesia. The kidney tissues were fixed in 4% formalin for one week before DEI experiment, with another 5 normal rabbits used as the control group. The experiment was performed at Beijing Synchrotron Radiation Facility (BSRF) with a 4W1A beam line (beam energy was 14keV). On routine scanning process, the rocking curve was detected, and slope position on the curve was selected to make a 360° spatial CT scan; DEI reconstruction software was used to generate a 3-dimensional image, from which the difference in grey value between the chronic glomerulonephritis (CGN) group and the control group was measured and analyzed using MATLAB and SPSS. RESULT: Without radio-contrast, DEI provided clear visibility of the microstructures including artery, vein, straight collecting ducts, papillary tubules, glomeruli in both the chronic glomerulonephritis (CGN) group and the control group, with a spatial resolution as low as 10µm. MATLAB grey value extraction and SPSS analysis showed that cortex of CGN group (91 to 112) lost more gray value compared to the control group (121 to 141), T tests P <  0.05. Equivalant cortical ROI (data points 450×80) quantitative analysis showed that gross grey value of CGN group (ranking from 55 to 160) was smaller than the control group (ranking from 75 to 175). DEI images correlated well with pathologic images. Morphological changes in the microstructure of contstartabstractCGN kidney was revealed, due to the advantage of phase-contrast imaging (PCI) mechanism, and the diagnostic value of CGN by synchrotron radiation (SR) phase-contrast imaging (PCI) technology was evaluated. CONCLUSION: Synchrotron radiation (SR) diffraction enhanced imaging (DEI) experiment makes non-contrast CGN diagnosis possible in the rabbit model studied. With improvement of laboratory equipment and image analyzer in clinical practice, diffraction enhanced imaging (DEI) could fundamentally become a new diagnostic method for CGN.