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Biomedical subjects

S Capellari

Publications and source records attributed to S Capellari.

25 records · Page 2Linked to original sources
PubMed1998

Creutzfeldt-Jakob disease with long duration and panencephalopathic lesions: molecular analysis of one case.

A 49-year-old woman presented with isolated aphasia followed by dementia and ataxia with a duration of 4 years. Histopathologically there was panencephalic involvement, status spongiosus, and kuru-type plaques. Molecular analysis showed heterozygosity at codon 129 in the prion protein (PrP) gene, and type 2 protease-resistant PrP. The comparison between this case and those previously reported suggests that the panencephalopathic variant of Creutzfeldt-Jakob disease (CJD) is an aspecific end-stage condition displayed by most if not all CJD variants in individual patients with an unusually prolonged course.

Biopsy↗
PubMed1997

Allelic origin of the abnormal prion protein isoform in familial prion diseases.

The hallmark of prion diseases is the presence of an aberrant isoform of the prion protein (PrP(res)) that is insoluble in nondenaturing detergents and resistant to proteases. We investigated the allelic origin of PrP(res) in brains of subjects heterozygous for the D178N mutation linked to fatal familial insomnia (FFI) and a subtype of Creutzfeldt-Jakob disease (CJD178), as well as for insertional mutations associated with another CJD subtype. We found that in FFI and CJD178 subjects, only mutant PrP was detergent-insoluble and protease-resistant. Therefore, PrP(res) derives exclusively from the mutant allele carrying the D178N mutation. In contrast, in the CJD subtype harboring insertional mutations, wild-type PrP was also detergent-insoluble and likely to be protease-resistant. Our findings indicate that the participation of the wild-type PrP in the formation of PrP(res) depends on the type of mutations, providing an insight into the molecular mechanisms underlying the phenotypic heterogeneity in familial prion diseases.

Alleles↗
PubMed1997

Familial prion disease with a novel 144-bp insertion in the prion protein gene in a Basque family.

Three members of a Basque family carrying a novel six R2 octapeptide repeat 144-bp insertion in the prion protein gene (PRNP) showed a slowly progressive dementia associated with cerebellar signs, myoclonic jerks, and seizures. Although postmortem examination revealed only focal and minimal spongiform degeneration in one subject with a 4-year course, significant astrogliosis and neuronal loss were associated with pronounced spongiform degeneration in the patient with a duration of symptoms of 10 years. Prion protein (PrP)-immunoreactive patches with a unique morphology were present in the molecular layer of the cerebellum in both subjects. Western blot analysis demonstrated the presence of protease-resistant prion protein (PrPres) with the same characteristics (size and ratio of the three differently glycosylated isoforms) of that found in typical sporadic Creutzfeldt-Jakob disease (CJD129M/M, PrPres type 1). The amount of PrPres correlated with presence and severity of spongiform degeneration in the cerebral cortex. The findings suggest that a relatively low rate of PrPres deposition is the cause of the lack of spongiform degeneration in subjects carrying a 144-bp insertion in PRNP. The presence of PrP-immunoreactive patches with unique morphology in the molecular layer of the cerebellum is a hallmark of certain prion encephalopathies with insertional mutations and is useful in the diagnosis of this subtype of human prion disease.

Adult↗
PubMed1996

Molecular basis of phenotypic variability in sporadic Creutzfeldt-Jakob disease.

We sequenced the prion protein gene and studied the biochemical characteristics and the intracerebral distribution of protease-resistant prion protein with Western blot and immunohistochemistry in 19 cases of sporadic Creutzfeldt-Jakob disease. We identified four groups of subjects defined by the genotype at codon 129 of the prion protein gene, the site of a common methionine/valine polymorphism, and two types of protease-resistant prion proteins that differed in size and glycosylation. The four Creutzfeldt-Jakob disease groups showed distinct clinicopathological features that corresponded to previously described variants. The typical Creutzfeldt-Jakob disease phenotype or myoclonic variant and the Heidenhain variant were linked to methionine homozygosity at codon 129 and to "type 1" protease-resistant prion protein. The atypical and rarer variants such as that with dementia of long duration, the ataxic variant, and the variant with kuru plaques were linked to different genotypes at codon 129 and shared the "type 2" protease-resistant prion protein. Our data indicate that the sporadic form of Creutzfeldt-Jakob disease comprises a limited number of variants. The methionine/valine polymorphism at codon 129 of the prion protein gene and two types of protease-resistant prion proteins are the major determinants of these variants. These findings suggest the existence of prion strains in humans and provide the molecular basis for a novel classification of sporadic Creutzfeldt-Jakob disease.

Adult↗
PubMed1996

Early pathologic and biochemical changes in Creutzfeldt-Jakob disease: study of brain biopsies.

We examined brain biopsy tissue from five patients with a neurologic syndrome consistent with Creutzfeldt-Jakob disease using Western blot analysis and immunohistochemistry for the detection of protease-resistant prion protein, in addition to histopathologic examination. Our results indicate that the formation of protease-resistant prion protein is an early event in disease pathogenesis and Western blot analysis can detect protease-resistant prion protein in the absence of structural lesions using a small amount of brain biopsy tissue.

Adult↗
PubMedDate not supplied

Arylsulfatase A pseudodeficiency and Lafora bodies in a patient with progressive myoclonic epilepsy.

Since age 12 years, a 25-year-old woman had a syndrome with myoclonic epilepsy, cerebellar signs, and spontaneous myoclonus. Skin biopsy showed typical Lafora bodies (LB), but she lacked a progressive course and mental impairment, hallmarks of Lafora disease. Lysosomal enzyme assays showed low level arylsulfatase A (ASA) activity. DNA study disclosed a homozygous ASA Pd genotype. Both parents carried one Pd allele. The still-unknown relationship between the pathologic level of ASA activity and myoclonic epilepsies suggests introduction of ASA assays in patients with PME.

Adult↗