Frequent alterations of specific reiterated DNA sequence abundances in human cancer.

An in-gel renaturation method allows the visualization, quantitation, and initial characterization of reiterated DNA restriction fragments (RRFs) without prior possession of their probes. Using this method we analyzed EcoRI restricted DNAs from ten human tumors, paired normal tissues from these patients, ten unpaired tumors, and 26 noncancer patients. Frequent qualitative and quantitative differences in the relative radioactive intensities of all or specific RRFs in the DNA from different individuals have been observed. However, we also report frequent two- to ten-fold alterations in the relative radioactive intensities of several specific RRFs in tumor-control analyses of DNA from the same individual. A 0.65-kb alphoid-like DNA RRF was decreased in six tumors and increased in none. Moreover, a new 1.55-kb RRF was observed in two colon cancer DNAs. Several new RRFs, suggestive of gene amplification, were detected in a neuroblastoma, two of which were also seen in a glioma. These data support frequent qualitative and quantitative alterations of specific reiterated DNA sequences in human cancer when compared with paired controls. This approach will allow the future characterization of specific DNA sequences whose patterns of altered reiteration suggest a role in the emergence of specific malignancies.

Glutamate and malate dehydrogenase activities in Joseph disease and olivopontocerebellar atrophy.

The activities of brain glutamate dehydrogenase and malate dehydrogenase were not statistically different in samples from patients with autosomal dominant olivopontocerebellar atrophy or Joseph disease compared with control subject samples. These two enzymes are thus not involved in the pathogenesis of these two separate dominantly inherited diseases.

Diagnosis of Colorado tick fever virus infection by enzyme immunoassays for immunoglobulin M and G antibodies.

An immunoglobulin M (IgM) capture enzyme immunoassay technique was adapted for the detection of antibody to Colorado tick fever virus in sera from 84 individuals for whom diagnosis had been confirmed by virus isolation or neutralization test. Titers were compared with those for IgG and neutralizing antibodies in these Colorado tick fever cases. IgM antibody titers were higher than neutralizing antibody titers, but neither appeared until 1 to 2 weeks after the onset of illness. Neutralizing antibodies were detected earlier than IgM antibodies, and both were detected with greater frequency than IgG antibodies. Late-convalescent-phase sera contained both neutralizing and IgG antibodies, but IgM was all but undetectable by 2 months after onset. Although the neutralization test may remain the serological test of choice, the enzyme immunoassay for IgM antibody offers a simple and more rapid method of serodiagnosis; the enzyme immunoassay is, however, less sensitive than the neutralization test. Furthermore, because there was a sharp decline in IgM antibody after 45 days, the presence of IgM antibody in a single serum sample provides a basis for the presumptive serodiagnosis of recent Colorado tick fever virus infection.