Some observations on caffeine-induced contracture of barnacle muscle fibers.
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Animals↗
Biomedical subjects
W Lin
Publications and source records attributed to W Lin.
Lumen definition in MR angiography.
Factors affecting blood vessel lumen definition for two-dimensional and three-dimensional inflow magnetic resonance (MR) imaging methods are considered. Vessel definition is affected (a) by the amount of dephasing of the blood in the vessels, both for uncompensated and velocity-compensated gradients; (b) by the image reconstruction technique (normal Fourier reconstruction when asymmetric echoes are collected or a maximum-intensity projection technique in post-processing); (c) by loss of signal due to T2* dephasing; (d) by misregistration; (e) by vessel wall motion; and (f) by partial-volume effects. The first two factors were found to dominate for resolution on the order of 1 mm3. To overcome these dephasing problems, the authors developed asymmetric echo, velocity-compensated sequences with TEs as short as 4.8 msec. The data were then reconstructed with an iterative partial Fourier algorithm, enabling improved lumen definition to be obtained in phantoms and in vivo.
Artifacts↗
Gadolinium-enhanced high-resolution MR angiography with adaptive vessel tracking: preliminary results in the intracranial circulation.
To overcome problems associated with poor contrast between vessels and background tissue in time-of-flight magnetic resonance angiography, the role of intravenous gadopentetate dimeglumine in conjunction with a postprocessing adaptive vessel tracking scheme was studied. Vessel tracking makes it possible to discriminate arteries from veins, to prevent problems associated with other bright tissues on maximum-intensity projections, and to increase the signal-to-noise ratio. Short, asymmetric, velocity-compensated field echoes were used in conjunction with high-resolution imaging techniques to spatially discriminate between adjacent vessels and stationary background tissue. Gadopentetate dimeglumine was shown to be useful for visualization of small vessels, aneurysms, and regions of slow flow, when used with this post-processing scheme.
Adolescent↗
Automated local maximum-intensity projection with three-dimensional vessel tracking.
Despite the simplicity and widespread acceptance of the maximum-intensity-projection (MIP) technique for displaying three-dimensional (3D) magnetic resonance angiographic data, several disadvantages are associated with MIP as it is applied to all of the 3D data. These include elevated noise level, reduced contrast between small vessels and background tissue, and the inability to distinguish arteries from veins. The authors have developed a 3D vessel tracking method combined with a local MIP around a given vessel to complement conventional MIP and alleviate these problems. The method is referred to as a traveling MIP (TMIP). TMIP was evaluated in both patients and healthy volunteers. The results indicate that TMIP provides better contrast between vessels and background tissue, better lumen definition, and better vascular visualization than either MIP or vessel tracking alone.
Algorithms↗
Preparation of human serum albumin microspheres by a novel acetone-heat denaturation method.
Human serum albumin (HSA) microspheres have been produced in the size range of 200 nm to 10 microns by the controlled addition of acetone to an aqueous solution of HSA, followed by stabilization of the formed microspheres at an elevated temperature. Microspheres produced by this acetone-heat denaturation method could be stabilized at relatively low temperatures (75 degrees C) over a short time period (15-30 min). The acetone-heat denaturation method is different from the traditional oil/water technique for preparation of HSA microspheres, both in terms of production method and the avoidance of high temperatures (> 100 degrees C) and extended heating times (> 30 min) for stabilization. This paper describes the influence of process conditions, such as volumes of acetone and HSA concentration, on the formation of the microspheres and their morphological characteristics. A loading efficiency of 8 per cent was achieved for the HSA microspheres when using rose bengal as a model compound. The release of rose bengal from the microspheres in phosphate buffered saline at 37 degrees C was dependent on the presence of the surfactant Tween 80, and varied from a 5 per cent release in 14 days in the absence of surfactant to a 50 per cent release in 8 h in the presence of surfactant.
Acetone↗
Isolation of an apathogenic immunogenic strain of duck enteritis virus from waterfowl in California.
A herpesvirus isolated from waterfowl dying of duck enteritis (DE) was tentatively designated the Sheridan-83. It was serologically related to the original Holland and Lake Andes (LA) strains of duck enteritis viruses (DEV). Other biological characteristics indicated that the Sheridan-83 was more closely related to the Holland strain than to the LA virus. The Sheridan-83 was nonpathogenic to ducks, and ducks inoculated with this virus developed resistance to challenge with the virulent strain LA.
Animals↗
Vaccination of turkeys against air-sac infection with a temperature-sensitive mutant of Mycoplasma gallisepticum.
Turkeys were vaccinated with temperature-sensitive (TS) mutants of Mycoplasma gallisepticum (MG) to determine pathogenicity and immunogenicity. TS 37 was apathogenic yet immunogenic to turkeys, TS 100 was highly pathogenic, and TS 102 was slightly pathogenic and nonimmunogenic. Five or 7 weeks after intranasal vaccination of turkeys with the TS 37 mutant, a highly statistically significant resistance against intra-air-sac challenge with the S6 strain of MG was observed.
Air Sacs↗