Koji Seki

Pick's disease: selective occurrence of apolipoprotein E-immunoreactive Pick bodies in the limbic system

Abstract We carried out immunohistochemical examination of apolipoprotein E (apoE) in brains from two patients with Pick’s disease. In these cases 1 and 2, the APOE genotypes were ɛ3/4 and ɛ3/3, respectively. In both cases, numerous argyrophilic globular intraneuronal inclusions, Pick bodies (PBs), were distributed widely throughout the brain, and immunohistochemically were occasionally positive for apoE. Interestingly, such apoE-immunoreactive PBs were virtually restricted to neurons in the limbic system; in the dentate gyrus, the proportion of apoE-immunoreactive PBs relative to the total number of argyrophilic PBs was 5.0% in case 1 and 2.7% in case 2, whereas in the frontal and temporal neocortices it was less than 0.1% in both cases. Diffuse cytoplasmic immunoreactivity for apoE was found in only a few limbic system neurons without PBs in both cases. In conclusion, it is considered that apoE may not be positively involved in the process of PB formation and that the preferential distribution of apoE-immunoreactive PBs in the limbic system may reflect the presence of certain regional factors associated with the synthesis or metabolism of apoE in this particular system.

Absence of linkage disequilibrium at amyloid precursor protein gene locus in Japanese familia Alzheimer's disease with 717Val→Ile mutation

To date, eleven independent FAD pedigrees with the 717Val-->Ile mutation have been identified. Interestingly, five pedigrees were of Japanese origin and four were of British origin. The apparent ethnic prediction of this mutation raises the possibility that there is a founder effect in these two island nations. We did not observe any significant linkage disequilibrium in any locus of APP and GT12 loci in the five Japanese FAD pedigrees with the 717Val-->Ile mutation. A founder effect would probably not be present in Japanese FAD pedgrees with the 717Val-->Ile mutation.

Circulating Autoantibody to Mature Neurons and Astrocytes of Humans and Some Mammals Present in a Demented Patient with Autoimmune Disorder

Circulating autoantibody to a 48-kD nuclear protein in neurons and astrocytes of the human and bovine cerebrum were present in the serum of a demented patient with an autoimmune disorder. Other human visceral organs, dorsal root ganglion cells, neuroblastoma and glioblastoma cell lines, and rat cerebrum did not react with the patients serum. No sera from age-matched controls, including those with Alzheimers disease, reacted with the 48-kD protein. Only the mature neurons and astrocytes of humans and some mammals express the 48-kD protein. This antibody may be responsible for the patients demented condition.