[A case of codon 232 mutation-induced Creutzfeldt-Jakob disease visualized by the MRI-FLAIR images with atypical clinical symptoms].

A 50-year-old man was admitted to our hospital because of disorientation and nocturnal restlessness. The patient presented chronically progressive dementia. No myoclonus or periodic synchronous discharge (PSD) was found over time, with abnormal evidence in MRI-FLAIR (fluid-attenuated inversion recovery) images alone. Brain biopsy and prion protein gene analysis led to the final diagnosis of Creutzfeldt-Jakob disease (CJD) induced by the point mutation at codon 232 (Met to Arg). To date the cases of M232R mutation-induced CJD have been reported to present clinical symptoms and pathological evidences similar to sporadic CJD cases, and differential diagnosis between the types has been believed to be difficult. Our case suggests that some types of CJD induced by point mutation at codon 232 cannot be easily inferred from clinical findings.

[An autopsy case with lower motor neuron disease showing a transient-appearance of anti-GM1 antibody and an improvement of conduction block after gamma-globulin administration].

We report a 63-year-old man who died of respiratory failure. He was well until 1992 (57 years of his age), when he had an onset of progressive weakness of the bilateral upper limbs. He showed no improvement with TRH administration in other hospital. On January 12, 1994, he admitted to our department because of the progressive muscle weakness. Neurologic examination revealed a muscular atrophy associated with severe weakness and hyporeflexia in both upper limbs, and fasciculation were seen in his tongue. Electrophysiological studies revealed mild conduction block in the left medial nerve, and F-waves were not evoked in the left ulnar nerve and bilateral median nerves. After an administration of 25 g/day of human gamma-immunoglobulin for 5 days, conduction block as well as F-wave abnormalities in the left median and left ulnar nerve were improved, yet no improvement of muscle weakness was seen. The anti-GM1 IgG titer was transiently elevated in the patient's serum after gamma-immunoglobulin therapy. On September 8, 1994, subtotal gastrectomy was performed because of the early stage gastric cancer. Histological examination showed poorly differentiated adenocarcinoma (signet-ring cell carcinoma). His muscle weakness had been gradually extended to the lower limbs and he couldn't walk himself on January, 1998. On March, 1998, he developed tetraplegia, mild dysphagia, dysuria and the respiratory disturbance. On April 12, 1998, he admitted to our department for the second time. Neurologic examination revealed a muscular atrophy and fasciculation associated with severe weakness in all of his limbs, tongue and musclus masseter. Neither deep tendon reflex nor pathologic reflex was evoked in his upper and lower extremities. His ocular movements and sensations were well preserved. He died of respiratory failure on May 1, 1998. The patient was presented in a neurological CPC. Neurological and laboratory findings suggested a spinal progressive muscular atrophy (SPMA). However, there were several unusual points as a typical SPMA in this case, that is, an improvement of the electrophysiological abnormalities by gamma-globulin treatment, as well as transient elevation of anti-GM1 antibody. The clinical neurologists have arrived at the conclusion that the patient had lower motor neuron syndrome associated with anti-ganglioside antibody and cause of death was ascribed to the respiratory failure. We discussed whether this case was SPMA or multifocal motor neuropathy. Postmortem examination revealed numerous diverticulums in the ascending colon and lymphothyroiditis. No recurrent carcinoma was detected. Neuropathologically, both severe atrophy of the anterior spinal roots, and severe gliosis and neuronal loss in the anterior horn of the spinal cord were observed. Onuf nuclei were not affected. Neurogenic muscular atrophy was detected in the tongue, diaphragm, and limb muscles. Motor neurons of the brainstem were relatively preserved, but skein-like inclusions as detected by anti-ubiquitin antibody, were present in the facial and hypoglossal nuclei. Neither motor cortex nor cortico-spinal tracts were affected. Demyelination, remyelination or cellular infiltrations were not apparent in the right median nerve and sciatic nerves. The neuropathologic features were compatible with SPMA.

Differential expression of transforming growth factor-beta isoforms in human prion diseases.

To examine the involvement of transforming growth factor-beta (TGF-beta) in the pathogenesis of prion diseases, immunohistochemical studies on both TGF-beta isoforms (beta 1, beta 2 and beta 3) and TGF-beta receptor type II (TGF-beta RII) were performed on the cerebral neocortices of 20 cases with human prion diseases, three cases with Alzheimer's disease, and five control cases. TGF-beta 2 immunoreactivity was thus detected in most neurons and astrocytes in all observed cases of prion disease. TGF-beta 3 immunoreactivity in the astrocytes and TGF-beta RII in the neurons were also detected in 17 of 20 cases with prion diseases. These immunoreactivities had increased markedly regarding the intensity and the number of positive cells in comparison to the control cases, but they were indistinguishable from those observed in Alzheimer's disease cases. In contrast, the TGF-beta 1 immunostaining did not show any apparent difference. Among the cases with prion diseases, however, no significant correlation was revealed between the immunohistochemical results and the clinical and pathological features. The results showed that TGF-beta isoforms thus appear to be differentially involved in the pathogenesis of prion diseases in a similar manner to that of Alzheimer's disease. Furthermore, two cases of prion disease in which pathological findings were free from astrogliosis and neuronal cell degeneration in the cerebral cortices also showed an increased immunoreactivity for TGF-beta 2. Thus, this result suggests that TGF-beta 2 may be involved in the early stages of neuronal cell degeneration in prion diseases.

Structure and expression of the alternatively-spliced forms of mRNA for the mouse homolog of Alzheimer's disease amyloid beta protein precursor.

The human amyloid beta protein (BP) is a major constituent of the amyloid deposited in the brain of patients with Alzheimer's disease and is derived from a larger precursor protein (BPP). In human three alternatively-spliced forms of BPP mRNA were found and two of them were shown to encode a protease inhibitory activity. We have isolated the corresponding species of cDNA in mice and found that the inhibitor domain is highly conserved through mammalian evolution. The homology between human and mouse was 94.6%. Northern blot using specific probes showed that the mRNA for BPP with inhibitor domain was present in every tissue, particularly at a higher level in the kidney. On the other hand, that without inhibitor domain was found most abundantly in the brain but much less in the kidney and the intestine. These data suggest that the individual BPP mRNA species were produced in a tissue-specific manner in mouse as in the case of human.