Biomedical subjects
Publications and source records attributed to R F MacDonald.
Line graphs that average response frequency over long periods obscure the major rate changes that indicate sources of behavioral control. A scatter plot can make patterns of responding identifiable and, in turn, suggest environmental features that occasion undesirable behavior. Use of scatter diagrams is illustrated in three cases.
Ninety-two patients who satisfied the criteria proposed by Kellgren for the diagnosis of ankylosing spondylitis were re-evaluated by clinical, radiological and laboratory parameters after an average length of illness of 18.7 years. The following associated clinical lesions were studied: aortic insufficiency 8%, heart block 3%, iritis 11%, and other associated lesions. Long-term effects of x-ray therapy were evaluated by comparing irradiated and non-irradiated patients; no significant difference was noted in the clinical course of these two treatment groups. On serum protein electrophoresis no characteristic dysproteinemia was demonstrated; in no instance was there a marked hypergammaglobulinemia. Test results for rheumatoid factor, antinuclear factor and antithyroglobulin were all within the range expected for a normal population. In addition to bilateral sacroiliitis, several other characteristic radiological lesions, such as anterior spondylitis, were present in a high percentage of cases. It is suggested that the diagnostic criteria proposed by Kellgren, although useful, should be enlarged and refined.