Quantitative MRI studies for assessment of multiple sclerosis.

Although magnetic resonance imaging (MRI) is a valuable aid in the initial diagnosis of multiple sclerosis (MS), quantitatively MRI has been disappointing in staging and evaluating therapy protocols by means of serial examinations. In this study, image processing algorithms were developed for the global analysis of MR images of the cerebrum. Limited three-dimensional segmentation was achieved through histogram analysis by these algorithms, which are essentially operator independent. The effects of coil response and tip angles, patient positioning, and interslice gap thicknesses were examined for 10 MS patients with repeated examinations for a total of 72 images. Effects of technique and instrumentation errors were approximately 6%, and agreement between two independent operators for measuring the total MR pixel sum from periventricular effusions and intense MS plaques was better than 97% with a standard deviation of 2.9%.     

Lymphocyte surface markers in acute rheumatic fever and post-streptococcal acute glomerulonephritis.

Lymphocyte cell-surface markers were examined in forty children with acute rheumatic fever (ARF) and twelve with acute post-streptococal glomerulonephritis (AGN) and compared to thirty-six normal controls of similar age. Cell-surface-marker studies included surface Ig using fluorescein-labelled F(ab)2 anti-F(AB')2, IgG aggregate binding cells, and EAC rosettes. T cells were identified both as 'active' rosettes and total E-binding cells. Proportions and absolute numbers of cells bearing surface Ig and Fc receptors were elevated in subjects with AGN (Pless than0-01-0-5), whereas proportions of cells producing EAC rosettes were diminished. Patients with acute rheumatic carditis or chorea showed a substantial elevation in proportions and numbers of active T-cell rosettes (Pless than0-01). Streptococcal antigen binding cells capable of forming rosettes with autologous cells coated with group A streptococcal membranes were elevated in the acute phase of both rheumatic fever and acute glomerulonephritis(Pless than0-01). The majority of such cells were removed by passage over insolubilized Ig-anti-IgG columns and appeared to be B cells.     

Serodiagnosis of leprosy: relationships between antibodies to Mycobacterium leprae phenolic glycolipid I and protein antigens.

Sera from leprosy patients and controls were assayed for immunoglobulin M (IgM) and IgG antibodies to the Mycobacterium leprae-specific phenolic glycolipid I antigen (PG) by enzyme-linked immunosorbent assay, for IgG antibodies to M. leprae protein antigens by Western immunoblot, and for antibodies to a 65-kilodalton (kDa) protein antigen of M. leprae by a competition antibody binding assay. Elevated levels of anti-PG IgM were seen in lepromatous and borderline lepromatous patients, and elevated levels of anti-PG IgG were seen in borderline lepromatous patients. There was a significant correlation between the bacillary index (BI) and anti-PG IgM whether all leprosy patients or only multibacillary patients were analyzed. A significant correlation was seen between anti-PG IgG and BI when all leprosy patients were used for analysis, but not when only multibacillary patients were used. IgG antibodies to protein antigens of M. leprae, as detected by Western immunoblot, were more prevalent in lepromatous and borderline lepromatous patients than in borderline tuberculoid patients, while one of eight controls showed one weak band. There were significant correlations between the number of M. leprae protein antigens detected by the sera of patients and both BI and the level of anti-PG IgM. The 65-kDa competition antibody binding assay detected active multibacillary leprosy. Patients positive for antibody to the 65-kDa antigen had a significantly higher BI and levels of anti-PG IgM and anti-PG IgG than did patients that were negative. In addition, the level of antibody to the 65-kDa antigen correlated with both the BI and anti-PG IgM. We conclude that testing for antibodies to protein antigens of M. leprae may provide a useful adjunct to testing for antibodies to PG.