http://repub.eur.nl/res/aut/1056/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/23952/ 2010-01-01T00:00:00Z This article examines the trade policy response of Latin American governments to the rapid growth of Chinese and Indian exports in world markets. To explain more protection in sectors where a large share of imports originates in China and India, the "protection for sale" model is extended to allow for region-specific degrees of substitutability between domestic and imported varieties of a good. The results suggest that more protection toward Chinese and Indian goods can be explained by the higher substitutability of Chinese and Indian goods with domestic varieties. The data support the model, which performs better than the original protection for sale framework in explaining Latin America's structure of protection. JEL classification numbers: F10, F11, F13 http://repub.eur.nl/res/pub/5074/ 1995-08-01T00:00:00Z http://repub.eur.nl/res/pub/21638/ 1995-05-31T00:00:00Z Investigation of the characteristics of the atheromatous plaque has gained new interest since the advent of pharmacological and mechanical intervention in the coronary arteries. Most of the information available on plaque substrate and its modification by such interventions was based in pathological or angiographic studies. However, major bias occurs when these sources of knowledge are used. Post-mortem studies afe performed only in those patients with the extreme of the clinical manifestations of a syndrome and a faral outcome, or in cases where death occurred as a consequence of failed intervention. On the other hand, angiography constitutcs a "shaclowgram» or luminogram which provides limited insights on the nature of coronary obstruction, and no infonnation as to the characteristics of the arterial wall and. Catheter based intracoronary imaging techniques provide a major opportunity to solve the above discllssed limitations. Intracoronary ultrasound and angioscopic imaging provide complementary information as to the structure and composition of the arterial wall and the modifications in the luminal surface of the coronary arteries. http://repub.eur.nl/res/pub/5071/ 1995-01-01T00:00:00Z Background Postmortem-derived findings support the common beliefs that lipid-rich coronary plaques with a thin, fibrous cap are prone to rupture and that rupture and superimposed thrombosis are the primary mechanisms causing acute coronary syndromes. In vivo imaging with intracoronary techniques may disclose differences in the characterization of atherosclerotic plaques in patients with stable or unstable angina and thus may provide clues to which plaques may rupture and whether rupture and thrombosis are active. Methods and Results We assessed the characteristics of the ischemia-related lesions with coronary angiography and intracoronary angioscopy and determined their compositions with intracoronary ultrasound in 44 patients with unstable and 23 patients with stable angina. The angiographic images were classified as noncomplex (smooth borders) or complex (irregular borders, multiple lesions, thrombus). Angioscopic images were classified as either stable (smooth surface) or thrombotic (red thrombus). The ultrasound characteristics of the lesion were classified as poorly echo-reflective, highly echo-reflective with shadowing, or highly echo-reflective without shadowing. There was a poor correlation between clinical status and angiographic findings. An angiographic complex lesion (n=33) was concordant with unstable angina in 55% (24 of 44); a noncomplex lesion (n=34) was concordant with stable angina in 61% (14 of 23). There was a good correlation between clinical status and angioscopic findings. An angioscopic thrombotic lesion (n=34) was concordant with unstable angina in 68% (30 of 44); a stable lesion (n=33) was concordant with stable angina in 83% (19 of 23). The ultrasound-obtained composition of the plaque was similar in patients with unstable and stable angina. Conclusions Angiography discriminates poorly between lesions in stable and unstable angina. Angioscopy demonstrated that plaque rupture and thrombosis were present in 17% of stable angina and 68% of unstable angina patients. Currently available ultrasound technology does not discriminate stable from unstable plaques. http://repub.eur.nl/res/pub/4583/ 1994-02-01T00:00:00Z http://repub.eur.nl/res/pub/4587/ 1994-01-01T00:00:00Z Long-term changes in vasocontractility were examined in 23 coronary segments from 20 patients with variant angina using computer-based quantitative coronary angiography and ergonovine provocation tests repeated at an interval of 42 +/- 14 months. Measurements of vasospasticity at the sites of fixed stenoses were compared with values predicted by an elementary geometric theory based on the assumption that the cross-sectional area of a vessel wall is constant regardless of its state of vasoconstriction. While all patients were symptomatic initially, only 11 remained symptomatic at follow-up. At the initial provocation test, the response was correctly predicted in four segments, was lower than expected in one, and was stronger in 18. At follow-up, only one of the four segments in which the response had been initially predicted correctly again showed the predicted response and the remaining three showed a response weaker than expected; the one segment which was initially hypocontractile remained hypocontractile at follow-up; and of the 18 segments which were initially hypercontractile, 12 exhibited hypercontractility again, four had the predicted value and the remaining two showed hypocontractility. In only one of 23 segments did the geometric theory predict the behaviour of vasospasticity at the site of fixed stenosis on both tests. Vasospastic responsiveness is a dynamic process demonstrating temporal variability and is not directly predicted by geometric theory. http://repub.eur.nl/res/pub/4603/ 1994-01-01T00:00:00Z OBJECTIVES. The purpose of this study was to determine the predictive value of quantitative coronary angiography in the assessment of the functional significance of coronary stenosis as judged from the development of left ventricular wall motion abnormalities during dobutamine-atropine stress echocardiography. BACKGROUND. Coronary angiography is the reference method for assessment of the accuracy of noninvasive diagnostic imaging techniques to detect the presence of significant coronary stenosis. However, use of arbitrary cutoff criteria for the interpretation of angiographic data may considerably influence the true diagnostic accuracy of the technique investigated. METHODS. Thirty-four patients without previous myocardial infarction and with single-vessel coronary stenosis were studied with both quantitative angiography and dobutamine-atropine stress echocardiography. Two different techniques of quantitative angiographic analysis--edge detection and videodensitometry--were used for measurement of minimal lumen diameter, percent diameter stenosis and percent area stenosis. Two-dimensional echocardiographic images were collected during incremental doses of intravenous dobutamine and later analyzed using a 16-segment left ventricular model. Angiographic cutoff criteria were derived from receiver-operating curves to define the functional significance of coronary stenosis on the basis of dobutamine-atropine stress echocardiography. RESULTS. The angiographic cutoff values with the best predictive value for the development of left ventricular wall motion abnormalities during dobutamine-atropine stress echocardiography were minimal lumen diameter of 1.07 mm, percent diameter stenosis of 52% and percent area stenosis of 75%. Minimal lumen diameter was found to have the best predictive value for a positive dobutamine stress test (odds ratio 51, sensitivity 94%, specificity 75%). CONCLUSIONS. Automated quantitative angiographic measurement of minimal lumen diameter is a practical and useful index for determining both the anatomic and functional significance of coronary stenosis, and a value of 1.07 mm is the best predictor for a positive dobutamine stress test.