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Biomedical subjects

Alan Scott

Publications and source records attributed to Alan Scott.

5 recordsLinked to original sources

Performance evaluation of a thermal Doppler Michelson interferometer system.

The thermal Doppler Michelson interferometer is the primary element of a proposed limb-viewing satellite instrument called SWIFT (Stratospheric Wind Interferometer for Transport studies). SWIFT is intended to measure stratospheric wind velocities in the altitude range of 15-45 km. SWIFT also uses narrowband tandem etalon filters made of germanium to select a line out of the thermal spectrum. The instrument uses the same technique of phase-stepping interferometry employed by the Wind Imaging Interferometer onboard the Upper Atmosphere Research Satellite. A thermal emission line of ozone near 9 microm is used to detect the Doppler shift due to winds. A test bed was set up for this instrument that included the Michelson interferometer and the etalon filters. For the test bed work, we investigate the behavior of individual components and their combination and report the results.

Journal Article↗

Multiple-laboratory comparison of microarray platforms.

Microarray technology is a powerful tool for measuring RNA expression for thousands of genes at once. Various studies have been published comparing competing platforms with mixed results: some find agreement, others do not. As the number of researchers starting to use microarrays and the number of cross-platform meta-analysis studies rapidly increases, appropriate platform assessments become more important. Here we present results from a comparison study that offers important improvements over those previously described in the literature. In particular, we noticed that none of the previously published papers consider differences between labs. For this study, a consortium of ten laboratories from the Washington, DC-Baltimore, USA, area was formed to compare data obtained from three widely used platforms using identical RNA samples. We used appropriate statistical analysis to demonstrate that there are relatively large differences in data obtained in labs using the same platform, but that the results from the best-performing labs agree rather well.

Baltimore↗

Is aortic angiography necessary for accurate planning of endovascular aortic aneurysm stents?

UNLABELLED: Endovascular management of abdominal aortic aneurysms (AAA) relies upon accurate stent design. We hypothesized the length of the stent could be measured from computed tomogram (CT) generated 3D surface rendered images of the abdominal vessels, eliminating the need for digital subtraction angiography (DSA). METHODS: The CT scans from a consecutive series of 54 patients considered for endovascular AAA repair were reviewed. A TRIFAB Zenith (Cook) endovascular aortic stent was designed, using the manufacturer's sizing computer program. These hypothetical stents were compared to those that had been implanted, using measurements from both angiogram and CT (Spearman's test of correlation (p<0.05)). RESULTS: The stent body size and short limb extension (SLE) of stents in each group was similar (correlation coefficient 0.70(p<0.01) and 0.50 (p=0.014)), however, CT alone significantly underestimated the length of the long limb extension (LLE) (correlation coefficient 0.095). CONCLUSION: These data suggest that CT underestimates the tortuosity of iliac vessels. Aortic angiography is necessary for accurate AAA endovascular stent design.

Angiography, Digital Subtraction↗

Development of antigen detection ELISA for the diagnosis of brugian and bancroftian filariasis using antibodies to recombinant filarial antigens Bm-SXP-1 and Wb-SXP-1.

Antibodies specific to recombinant filarial antigens Wb-SXP-1 and Bm-SXP-1 have been used to develop a sandwich ELISA for the detection of circulating filarial antigen (CFA) in sera from patients with lymphatic filariasis caused by Wuchereria bancrofti of Brugia malayi. In patients with W. bancrofti infections, a high proportion of microfilaria (mf) positive (MF) and low proportions of patients with chronic pathology (CP) and endemic normals (EN) showed the presence of CFA. Similarly in patients with brugian infections a high proportion of mf positive individuals contained CFA while none of the patients with chronic pathology or endemic normals showed the presence of CFA. Sera from patients with other parasitic infections (OPI) like O. volvulus, Loa loa, Ascaris lumbricoides and from individuals residing in areas non-endemic to filariasis did not exhibit any reactivity. This assay shows promise for the detection of microfilaremic infections in lymphatic filariasis and its usefulness as a diagnostic tool especially in B. malayi infections, needs to be further evaluated.

Animals↗