HCFA support may affect all APNs.
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Centers for Medicare and Medicaid Services, U.S.↗
Biomedical subjects
B McFadden
Publications and source records attributed to B McFadden.
Influencing our growth: a tribute to two doctors.
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Humans↗
In vitro replication of cyanobacterial plasmids from Synechocystis PCC 6803.
Little knowledge of DNA replication in cyanobacteria is available. In this study, we report the development and characterization of an in vitro system for studies of replication of the endogenous plasmids from the unicellular cyanobacterium Synechocystis 6803. This system (fraction III) was isolated at high salt concentrations and partially purified on a heparin-agarose column. DNA polymerases in Synechocystis 6803 appeared to be associated with membranes and could be released by the addition of ammonium sulfate to 20% saturation. DNA synthesis in fraction III was dependent on the addition of cyanobacterial plasmids isolated from the same strain. The in vitro replication products consist mostly of the supercoiled form of the plasmids. Unlike replication of many Escherichia coli plasmids, replication of cyanobacterial plasmids did not require added ATP, was not inhibited by omission of the ribonucleotides, and was insensitive to the RNA polymerase inhibitor rifampicin and the gyrase inhibitor novobiocin, but was inhibited by ethidium bromide. These data suggest that RNA may not be involved in the initiation of replication of cyanobacterial plasmids from Synechocystis 6803. In addition, intermediates of replication have been detected by two-dimensional gel electrophoresis. Density labeling experiments also indicate that cyanobacterial plasmid synthesis in vitro occurs by a semiconservative replication.
Centrifugation, Density Gradient↗
Quality control for chest radiography.
A quality Control Program for Chest Radiography was established in a six room Radiology Department. After a preliminary educational session on the definition of a "good" chest film, and the factors which affect the image quality, a "Chest Team" was established. The technologists were divided into three groups: Standard Chest Group, Consistency Group and Monitoring Group. Each group served as a control for the other, resulting in standardization of all methods, techniques, and acceptance criteria in the department. A random inspection of chest radiographs, both before and after the project, showed significant improvement in the overall quality of chest films in the department over a three month period. Follow-up confirmed that the established standard was maintained with minimal effort.
Hospital Departments↗
Principles of radiographic exposure a new approach.
Radiographic technique charts have traditionally been established by the empirical method. A precisely calculated chart based on the effective energy of the spectrum and the output of the equipment will give more consistent results of density and contrast as well as repeatability of these results from patient to patient. A better understanding of patient attenuation and screen energy sensitivity will enable the radiographer to logically adjust technical factors to change density or contrast scales as required.
Radiation Protection↗