Xeroradiography and ionography: new technologies to replace the x-ray film

Novel methods of radiogram imaging are described and compared with conventional means. They include: xeoradiography, low- and high-pressure ionography and liquid phase ionography. The possibility of real time operation is considered also. Of these systems, xeroradiography is already in use for a limited range of applications. High pressure gas ionography shows great promise and practical systems may be expected to appear in the near future.     

Variations in normal coronary vasodilatory reserve stratified by artery, gender, heart transplantation and coronary artery disease

OBJECTIVES: The purpose of the study was to assess the spectrum of coronary vasodilatory reserve values in patients with angiographically normal arteries who had atypical chest pain syndromes or remote coronary artery disease or were heart transplant recipients. BACKGROUND: The measurement of post-stenotic coronary vasodilatory reserve, now possible in a large number of patients in the cardiac catheterization laboratory, is increasingly used for decision making. Controversy exists regarding the range of normal values obtained in angiographically normal coronary arteries in patients with different clinical presentations. METHODS: Quantitative coronary arteriography was performed in 214 patients classified into three groups: 85 patients with chest pain syndromes and angiographically normal arteries (group 1); 21 patients with one normal vessel and at least one vessel with > 50% diameter lumen narrowing (group 2); and 108 heart transplant recipients (group 3). Coronary vasodilatory reserve (the ratio of maximal to basal average coronary flow velocity) was measured in 416 arteries using a 0.018-in. (0.04 cm) Doppler-tipped angioplasty guide wire. Intracoronary adenosine (8 to 18 micrograms) was used to produce maximal hyperemia. RESULTS: Coronary vasodilatory reserve was higher in angiographically normal arteries in patients with chest pain syndromes (group 1:2.80 +/- 0.6 [group mean +/- SD]) than in normal vessels in patients with remote coronary artery disease (group 2: 2.5 +/- 0.95, p = 0.04); both values were significantly higher than those in the post-stenotic segment of the diseased artery (1.8 +/- 0.6, p < 0.007). Coronary vasodilatory reserve in transplant recipients (group 3) was higher than that in the other groups (3.1 +/- 0.9, p < 0.05 vs. groups 1 and 2) as a group and for individual arteries. When stratified by vessel, coronary vasodilatory reserve was similar among the left anterior descending, left circumflex and right coronary arteries. There were no differences between coronary vasodilatory reserve values on the basis of gender for patients with coronary artery disease and transplant recipients. In group 1 (chest pain), there was a trend toward higher coronary vasodilatory reserve in men than in women (2.9 +/- 0.6 vs 2.7 +/- 0.6, p = 0.07). CONCLUSIONS: These findings identify a normal reference range for studies assessing the coronary circulation and post-stenotic coronary vasodilatory reserve in patients with and without coronary artery disease encountered in the cardiac catheterization laboratory.     

Detection of the t(2;5)-associated NPM/ALK fusion cDNA in peripheral blood cells of healthy individuals

The translocation t(2;5), which leads to the fusion of the nucleophosmin gene (NPM) on chromosome 5q35 to the receptor kinase ALK on chromosome 2p23, is found in CD30+ anaplastic large cell lymphomas and some cases of B-cell lymphoma. Hodgkin's disease (HD) is a malignant lymphoma characterized by large multinucleated tumour cells, Hodgkin and Reed-Sternberg (H&RS) cells, surrounded by a dense lymphohistiocytic infiltrate. Our group recently demonstrated NPM/ALK fusion cDNAs by single-cell RT-PCR in < 3% of CD30+ tumour cells in 2/9 cases of HD. To further delineate the relevance of this finding for HD, we studied the occurrence of NPM/ALK fusion genes in peripheral blood cells of healthy donors by RT-PCR. NPM/ALK fusion cDNAs were found by RT-PCR in 14/29 healthy individuals and confirmed by hybridization with a breakpoint-specific oligonucleotide. Due to the low rate of NPM/ALK-positive cells in the peripheral blood of positive individuals, an assignment to a defined cellular subpopulation was not possible. We conclude that NPM/ALK fusion genes are present in peripheral blood cells of healthy donors. After t(14;18) and t(9;22), t(2;5) represents the third example of tumour-associated translocation products in blood cells of apparently healthy donors. The implications of this finding are discussed.     

Cost-effectiveness calculations from trials

EFFECTIVENESS OF ANTIHYPERTENSIVE THERAPY: Data on the effectiveness of antihypertensive therapy derived from the results of large clinical trials are of great importance, but also have a number of significant flaws and probably underestimate the real effectiveness of treatment. In the next few years much more information is likely to become available on the effects of the newer classes of drugs and thus evaluations of cost-effectiveness will have fewer limitations than at present. ECONOMIC VALUE OF SAVING A LIFE: Today, in every country worldwide, priority should be given to determining the economic cost of avoiding the morbidity and mortality caused by hypertension. Each society must decide the price per life-year gained that it is willing to pay. This is the most difficult task of all, since the economic value of saving a life is not easily evaluable.     

Drug-induced disorders

Recent estimates suggest that each year more than 1 million patients are injured while in the hospital and approximately 180,000 die because of these injuries. Furthermore, drug-related morbidity and mortality are common and are estimated to cost more than $136 billion a year. The most common type of drug-induced disorder is dose-dependent and predictable. Many adverse drug events occur as a result of drug-drug, drug-disease or drug-food interactions and, therefore, are preventable. Clinicians' awareness of the agents that commonly cause drug-induced disorders and recognition of compromised organ function can significantly decrease the likelihood that an adverse event will occur. Patient assessment should include a thorough medication history, including an analysis of all prescribed and over-the-counter medications, vitamins, herbs and "health-food" products to identify drug-induced problems and potentially reversible conditions. An increased awareness among clinicians of drug-induced disorders should maximize their recognition and minimize their incidence.     

Automatic Modulation Classification Using Information Theoretic Similarity Measures

Modem wireless systems employ adaptive techniques to provide high throughput while observing desired coverage, QoS （quality of service） and capacity. An alternative to further enhance data rate is to apply cognitive radio concepts, where a system is able to exploit unused spectrum on existing licensed bands by ＂sensing＂ the spectrum and opportunistically access unused portions. Techniques like AMC （automatic modulation classification） could help or be vital for such scenarios. Usually, AMC implementations rely on some form of signal pre-processing, which may introduce a high computational cost or make assumptions about the received signal which may not hold （e.g., Gaussianity of noise）. This work proposes a new method to perform AMC which uses a similarity measure from the ITL （information theoretic learning） framework, known as correntropy coefficient. It is capable of extracting similarity measurements over a pair of random processes using higher order statistics, yielding in better similarity estimations than by using e.g. correlation coefficient. Experiments with binary modulations show that in the presence of AWGN （additive white Gaussian noise）, a 97% success rate in classification is achieved at a SNR （signal-to-noise rate） of 5 dB without requiring any pre-processing at all.