During the past six months we have been studying the behavior of manganese in Escherichia coli cells in the hope that this approach might help to clarify some of the very interesting effects found by Demerec and Hanson (1951) in their work on the mutagenic action of manganese. With such a simple mutagenic agent, which can be followed with ease
Substantial variation in the virulence of Newcastle disease virus (NDV) isolates means that the detection of NDV or evidence of infection is insufficient for an adequate diagnosis, as control measures for avirulent viruses are very different to those for virulent viruses. Diagnosis therefore requires further characterization, at least as to whether an isolate is virulent or avirulent. Conventional detection and differentiation of ND viruses is perceived as slow, laborious and requiring an undesirable use of in vivo techniques. In addition, further characterization is needed to give greater information on origin and spread. This review concentrates on the application of monoclonal antibody and molecular biological approaches. Panels of monoclonal antibodies were a major advance for the characterization of NDV isolates, although confirmation of virulence for poultry still required in vivo testing. As molecular-based techniques become easier and more reliable, they are likely to supersede the use of monoclonal antibodies, especially for characterizing viruses for epidemiological purposes. The attraction of molecular-based techniques is that they may be able to cover all three aspects of Newcastle disease diagnosis (detection of virus, characterization, including inference of virulence, and epidemiology) quickly, accurately and definitively in a single test. A number of approaches based on the reverse transcriptase polymerase chain reaction have been developed, with subsequent analysis of the product by restriction enzyme analysis, probe hybridization and nucleotide sequencing. Although extensive variation among NDVs still poses technical problems, the real and potential advantages of a molecular biological approach to Newcastle disease diagnosis appear to be overwhelming.
Abstract Background Coronary artery disease (CAD) risk is underestimated in women using current risk stratification tools. The mammographic finding of breast arterial calcification (BAC) associates with CAD. Furthermore, breast adipose tissue, measured through breast density (BD) on mammography (low breast density indicates high adiposity) has shown potential to act as a pro-inflammatory, pro-atherogenic fat deposit. Given its uptake in screening programs, mammography may therefore represent a novel risk stratification tool for cardiovascular disease in women. Purpose To evaluate the association between the combined mammographic features of BD and BAC, with CAD. Methods Single-centre, retrospective, cross-sectional study, including 153 women, mean age 62±10, who had both clinically indicated mammography, and coronary computed tomography angiogram (CCTA) for suspected CAD. CAD risk was identified by the CAD Consortium Score, with a 15% threshold for low and high risk. BD was visually assessed and categorised by 4-level BI-RADS grade with grade A-B representing low density, and C-D representing high density (Figure 1). BAC was visually assessed and categorised as present/absent (Figure 1). CAD was categorised as presence/absence of coronary artery plaque on CCTA. Logistic regression was performed with results presented as Odds Ratio (OR) and [95% Confidence Intervals]. Receiver operator characteristic area under the curve (AUC) was used for model discrimination. Results Low BD (n=103 (67%)) was associated with CAD (OR 3.20 [1.58-6.53], p=0.001, as was BAC presence (n=37 (24%), OR 4.36 [1.58-12], p=0.004). There were 51 (33%) with elevated CAD risk. Participants were categorised into 4 subgroups based on low/high BD and presence/absence of BAC: 29 (19%) had low BD and BAC, 74 (48%) had low BD and no BAC, 8 (5%) had high BD and BAC and 42 (27%) had high BD and no BAC. Significantly higher proportions of CAD were noted with low BD and BAC alone, as well as combined low BD and BAC (Figure 2). Compared with high BD/BAC negative, the presence of low BD and BAC independently associated with CAD (OR 5.27 [1.19-23.3], p=0.03). Significant incremental benefit was seen after adding BD/BAC status to CAD Consortium Score (AUC 0.65 vs. 0.72, p=0.004). Conclusions Combined, and individual mammographic features of low BD and BAC presence are associated with CAD and improve risk prediction beyond standard coronary risk probabilities. Standardised reporting of these features to inform risk identification may be of further benefit and should be tested in prospective screening studies.