Biomedical subjects

T Kitamoto

Publications and source records attributed to T Kitamoto.

At least 37 records · Page 2Linked to original sources

PubMed1991

Immunoreactivity of cerebral amyloidosis is enhanced by protein denaturation treatments.

We investigated paraffin-embedded brain sections from three patients with Gerstmann-Sträussler syndrome and three patients with Alzheimer's disease or senile dementia of Alzheimer type using anti-human prion protein antisera and anti-beta/A4 protein antisera after protein denaturation treatments. After incubation with guanidine-thiocyanate, trichloroacetate, and phenol, the immunoreactivity of kuru plaques and senile plaques was enhanced to the same level as the formic acid treatment. These treatments revealed small compact amyloid deposits, amyloid deposits surrounding the plaque cores, and diffuse plaques. Most of these chemicals changed the congophilia of both amyloids. It is possible that these treatments denature amyloid fibril proteins and break down the structure of amyloid fibrils, thus revealing buried epitopes.

Adolescent↗

PubMed1991

Modified tau is present in younger nondemented persons: a study of subcortical nuclei in Alzheimer's disease and progressive supranuclear palsy.

Tau-positive neurons relating to neurofibrillary tangles and diffuse cytoplasmic stainings were quantitatively examined in the brains of 61 nondemented persons including 24 age-matched controls, 10 patients with Alzheimer's disease (AD) and 5 with progressive supranuclear palsy (PSP). In nondemented persons, the locus ceruleus (LC) was found to contain tau-positive neurons initially in persons in their 30s, whereas the hippocampus contained such neurons initially in persons in their 40s. The LC had a higher incidence and density than the hippocampus in almost all age classes. As neuronal tau accumulation is considered a histological change occurring with normal aging, the LC might be involved in the earliest aging in the normal brain. In AD there was conspicuous tau accumulation in the same sites which were vulnerable to tau accumulation in the age-matched controls. In PSP tau accumulated heavily in a set of sites different from the age-matched controls and AD. Thus, subcortical tau accumulation in AD is increased far more than that under normal aging process, while that in PSP is not simply in an increased state of the normal aging process.

Adult↗

PubMed1991

Practical methods for chemical inactivation of Creutzfeldt-Jakob disease pathogen.

Chemical inactivation of pathogen of Creutzfeldt-Jakob disease (CJD) was examined using the mouse-adapted CJD strain. A high concentration of formic acid, guanidine compounds, trichloroacetate and phenol prevented CJD transmission. NaOH between 0.25 and 2 N lengthened the incubation periods. Sodium dodecyl sulfate (SDS) in a concentration between 1 and 3% did not alter incubation at room temperature but did completely block the transmission after boiling for 3 min in 3% SDS. This method is recommended for practical disinfection.

Acids↗

PubMed1991

Abnormal isoform of prion protein accumulates in follicular dendritic cells in mice with Creutzfeldt-Jakob disease.

We established that follicular dendritic cells (FDCs) are the site of abnormal prion protein (PrPCJD) accumulations in lymphoid tissues from mice infected with Creutzfeldt-Jakob disease. Evidence of positive FDC staining was observed in Creutzfeldt-Jakob disease-infected mice irrespective of the inoculation route, while no such staining was seen in the control mice. We also found that the severe combined immunodeficiency mouse trait is transmittable via the intracranial route but not via the intraperitoneal route. Mice with severe combined immunodeficiency did not have PrPCJD accumulation in FDCs.

Animals↗

PubMed1991

Immunohistochemical quantification of substance P in spinal dorsal horns of patients with multiple system atrophy.

Using a computer-assisted image analyser, an immunohistochemical quantification method of substance P-like immunoreactivity (SPLI) in laminae I + II of spinal dorsal horn was established and applied to 13 patients with multiple system atrophy (MSA) with no disturbance of pain sensation, including olivo-ponto-cerebellar atrophy and striatonigral degeneration, and 13 neurologically normal controls. To investigate whether alteration of SPLI is related to an autonomic disorder, myelinated fibre counts of the fourth thoracic ventral roots were performed. Eleven of 13 MSA patients showed a significant decrease in small and large myelinated fibres, and were diagnosed with definite Shy-Drager syndrome (SDS), with the exception of two who had no apparent history of autonomic dysfunction. SPLIs in laminae I + II in 10 of these 11 patients, when adjusted for age, were significantly decreased at both levels of the fourth thoracic and third lumbar spinal segments. The results suggest the disorder of SP-containing synapses of primary afferent neurons and/or those of interneurons in SDS.

Adult↗

PubMed1991

A prion protein missense variant is integrated in kuru plaque cores in patients with Gerstmann-Sträussler syndrome.

Kuru plaques are the pathologic hallmark in Gerstmann-Sträussler syndrome (GSS). To demonstrate that prion protein (PrP) is a component of kuru plaque cores, we fractionated and sequenced kuru plaque core derived peptides, following digestion with Achromobacter lyticus protease I. We identified 3 PrP-derived peptides by reverse-phase high-performance liquid chromatography and found a fragment of digests derived from a missense variant of PrP. The variant PrP was also present in the prion rod fraction in patients with GSS. This substitution may play a major role in cerebral amyloidogenesis.

Amino Acid Sequence↗

PubMed1991

A comparative immunohistochemical study of Kuru and senile plaques with a special reference to glial reactions at various stages of amyloid plaque formation.

The authors examined 10 patients with Gerstmann-Sträussler syndrome or Creutzfeldt-Jakob disease and 10 with Alzheimer's disease (AD). Immunohistochemistry using anti-prion protein (PrP) and anti-beta/A4 protein (beta/A4) coupled with formic acid pretreatment could detect Congophilic and non-Congophilic deposits. Prion protein deposits were classified into five types and compared with types of beta/A4 deposits. Kuru plaques with multicentric cores and fine granular deposits were a characteristic feature of PrP deposits. Some types of PrP or beta/A4 deposits depend on the anatomic sites. To clarify the relationship of microglia and astrocytes to PrP or beta/A4 deposits, double-immunostaining method was performed. In both kuru and senile plaques, microglia were closely linked to the Congophilic plaques. Astrocytes, however, extended their processes toward the plaques even in the non-Congophilic plaques. These observations strongly suggest that similar glial association with plaque formation may be involved in both kuru and senile plaques, although the amyloid core proteins differ.

Alzheimer Disease↗

PubMed1991

Alzheimer's amyloid precursor protein-positive degenerative neurites exist even within kuru plaques not specific to Alzheimer's disease.

To clarify the relationship between amyloid formation and amyloid precursor protein (APP), the brain sections from eight patients with Alzheimer's disease (AD) and four with Gerstmann-Sträussler Syndrome (GSS) were investigated immunohistochemically by the double-immunostaining method. In AD, most APP-positive senile plaques belong to classical plaques or primitive plaques, whereas in diffuse plaques, APP-positive neuritic components are rarely observed. The authors documented that anti-APP-labeled degenerative neurites surrounding kuru plaques in all four GSS patients. These kuru plaques were verified by double immunostaining using anti-prion protein and anti-APP. The APP-positive structures in kuru plaques were almost identical with those seen in the classical plaques in AD. The authors concluded that APP-positive degenerative neurites are not an early event in the amyloid formation of senile plaques. It is therefore postulated that depositions of beta/A4 and prion proteins are primary events that may involve the surrounding microenvironment and result in the secondary formation of APP-positive degenerative neurites, not specific to AD.

Alzheimer Disease↗

PubMed1991

Hydrated autoclave pretreatment enhances tau immunoreactivity in formalin-fixed normal and Alzheimer's disease brain tissues.

We developed a new immunohistochemical method by which normal tau antigenicity can be visualized in paraffin sections of formalin-fixed brain tissue. This method consists of autoclave pretreatment of sections immersed into distilled water (hydrated autoclaving) before incubation with anti-tau antibodies. In normal human brain, immunoreactive tau was detected in neuronal cell bodies and dendrites, axon fibers, astroglia, oligodendroglia and gray matter neuropil. In previous studies on normal tau distribution, different optimized fixations that effectively preserve tau antigenicity were used but none of these revealed all of these compartments together. Our method is therefore considered to be more sensitive for detecting normal tau immunoreactivity. In addition, hydrated autoclaving had an enhancing effect on the abnormally phosphorylated (modified) tau immunoreactivity in formalin-fixed brains. In hydrated autoclaving of sections from patients with Alzheimer's disease, neuropil threads, senile plaques, extracellular and intracellular tangles were enhanced in quantity and in staining intensity. Therefore, modified tau appears to accumulate more densely than expected from conventional immunohistochemistry. Immunoblot analysis showed that normal or modified tau immunoreactivity was totally or partially eliminated on formalin treatment and could be revisualized by hydrated autoclaving, an event presumably related to recovering of formalin-masked tau antigens through denaturation by hydrated autoclaving.

Adult↗

PubMed1991

[Mutation of codon 117 of the prion gene in Gerstmann-Sträussler-Scheinker disease].

We report the clinical progression of the Gerstmann-Sträussler-Scheinker disease (GSS) in a family of Alsatian origin. The age of onset and duration of evolution were variable. The clinical picture became more complex over the generations: isolated dementia in the first generations, then, more recently, a triad of pyramidal, pseudobulbar syndrome and dementia associated with symptoms indicating spread of damage to the spinal cord and cerebellum. Study of the prion gene showed that in all patients analyzed and in 10 healthy family members, there is a double mutation of codon 117 leading to loss of the restriction site PvuII and to the replacement of an alanine by a valine. We did not find the mutation of codon 102 reported in 5 GSS families. The role of these mutations in the pathogenesis of the disease is unclear: marker for a particular susceptibility to the encephalopathies due to the prion, or direct role in the disease? Further study of the family, particularly the healthy carriers, could suggest the answer. GSS seems to be an especially useful model for the study of the role of a foreign abnormal protein in the synthesis and regulation of host proteins.

Chromosome Mapping↗

PubMed1990

Cerebral amyloid in mice with Creutzfeldt-Jakob disease is influenced by the strain of the infectious agent.

We examined Fukuoka-1 and Fukuoka-2 mouse-adapted Creutzfeldt-Jakob disease strains. Mice infected with the Fukuoka-2 strain have a higher incidence of kuru plaques, a higher concentration of proteinase-resistant prion protein, and a higher infectivity titer than do mice with the Fukuoka-1 strain. Thus, it must be kept in mind that there is a difference in the strain of the infectious agent in murine Creutzfeldt-Jakob disease.

Amyloidosis↗

PubMed1990

Creutzfeldt-Jakob disease patients with congophilic kuru plaques have the missense variant prion protein common to Gerstmann-Sträussler syndrome.

Congophilic kuru plaques, one of the pathological hallmarks in kuru and Gerstmann-Sträussler syndrome, are sometimes present in patients with Creutzfeldt-Jakob disease (CJD). The congophilic kuru plaques are composed partly of a host-encoded prion protein, and a missense variant prion protein with the codon 102 proline-to-leucine change (Leu102) is commonly present in patients with Gerstmann-Sträussler syndrome. To investigate the relationship between this syndrome and CJD with congophilic kuru plaques, we made a sequence analysis of the prion protein gene from patients with CJD, with or without congophilic kuru plaques. We found no alterations other than the Leu102 change, common to Gerstmann-Sträussler syndrome, in one of the prion protein alleles of the patient with congophilic kuru plaques. In the prion protein genotype analysis of other patients with CJD, the Leu102 allele was revealed to be carried heterozygously by 6 of 7 patients who had CJD with congophilic kuru plaques, yet no patient with CJD without congophilic kuru plaques had this allele. Interestingly, the Leu102 allele was also carried by some unaffected relatives of 3 patients with CJD with congophilic kuru plaques but with no apparent familial occurrence of a similar neurological disorder. Our findings show that CJD with congophilic kuru plaques should be categorized as belonging to Gerstmann-Sträussler syndrome, not CJD, and also suggest that the variant prion protein with Leu102 is closely related to the amyloidogenesis seen in subjects with congophilic kuru plaques.

Adult↗

PubMed1990

Immunogold light and electron microscopic detection of amyloid plaques in transmissible spongiform encephalopathies.

The antigenicity of the 'prion' protein amyloid fibrils was shown to be preserved after glutaraldehyde/OsO4 fixation in uranyl acetate-stained brain tissue blocks from patients with Gerstmann-Sträussler syndrome (GSS) and from mice infected with Creutzfeldt-Jakob disease (CJD). Amyloid plaques were demonstrated by light microscopy in immunogold silver-intensified semithin sections. Under the electron microscope, the amyloid fibrils were labelled in immunogold-reacted ultrathin sections using an antiserum prepared against GSS amyloid plaque cores and mouse amyloid fibrils respectively. The influence of various oxidizing agents (hydrogen peroxide, sodium metaperiodate) on the tissue preservation and the immunohistochemical detection was tested.

Amyloidosis↗

PubMed1990

Immunochemical, molecular genetic, and transmission studies on a case of Gerstmann-Sträussler-Scheinker syndrome.

Using immunostaining with anti-prion protein (PrP) antiserum, we detected numerous kuru plaques in the brain of a 24-year-old man with Gerstmann-Sträussler-Scheinker syndrome. Immunoreactivity on Western blotting of the protease-resistant PrP fraction from the frozen brain was weak. PrP gene analysis showed substitution of alanine to valine in codon 117 but no substitution in codon 102. As the experimental transmission of the disease to mice was negative, a pathogen of a relatively low infectivity may cause the disease in predisposed family members.

Adult↗

PubMed1989

Expression of cellular retinoic acid binding protein II (chick-CRABP II) in the chick embryo.

We previously demonstrated the presence of cellular retinoic acid binding protein II, chick-CRABP II, in chick embryos. In the present study, we investigated the distribution of chick-CRABP II in 14-day chick embryos by means of immunoblot analysis. Chick-CRABP II was expressed in skin, muscle, bone with tendon of the embryos, but not expressed in the nervous system. In adult chick tissues, chick-CRABP II was not detected on immunoblotting; Chick-CRABP II in adults amounts to less than 10 ng/mg soluble protein. These observations suggest that chick- CRABP II is an embryonic protein involved in the development of specific tissues, such as bone, muscle and skin.

Animals↗

PubMed1989

Pro----leu change at position 102 of prion protein is the most common but not the sole mutation related to Gerstmann-Sträussler syndrome.

The host-encoded prion protein (PrP) is a component of transmissible amyloid deposited in the brains affected by Gerstmann-Sträussler syndrome (GSS). Recently GSS in two unrelated Caucasian families has been reported to be linked to an amino acid change in PrP codon 102, proline to leucine (Leu102). However, it has not been clear whether the change is commonly found to GSS regardless of ethnic origin. We report here that Leu102 is also found in all the Japanese GSS patients tested. Interestingly, one French GSS patient was found to have another change, alanine to valine in codon 117 (Val117), instead of Leu102. Our results indicate that Leu102 is closely related to GSS irrespective of ethnic origin, but not the sole mutation related to GSS. Val117 may also be related to GSS.

Alleles↗

PubMed1989

Ferritin immunohistochemistry as a marker for microglia.

An immunohistochemical analysis of formalin-fixed, paraffin-embedded brain sections was performed with antisera against holoferritin and the light(L)-subunit of ferritin. Sections immunostained using anti-glial fibrillary acidic protein (GFAP), Ricinus communis agglutinin-1 (RCA-1) stain for microglia and iron stain (Berlin blue stain) were compared. The L-subunit of ferritin was purified from normal human spleen according to the modified scrapie-associated fibrils purification, and the anti-serum was raised in a rabbit. Both ferritin antisera positively stained resting and, more markedly, reactive microglia, both of which were also stained with RCA-1 but not with GFAP. Ferritin-positive resting microglia were seen more abundantly in cerebral and cerebellar cortices than in white matter. The advantages of ferritin antisera over RCA-1 are as follows. (1) RCA-1 heavily stains blood vessels, while anti-ferritin does not, hence the microglial cells are more readily visualized with ferritin immunohistochemistry. (2) Reactive microglia and macrophages are more strongly stained with anti-ferritin. (3) The staining intensity of ferritin is independent of the length of tissue fixation in formalin. However, anti-ferritin is inferior to RCA-1 in staining resting microglia with a scanty cytoplasm, especially in the white matter, probably because the former recognizes cytoplasmic components, while the latter recognizes cell membrane. Iron stain only gave a reaction to microglial cells in brains with neurosyphilis and to hemosiderin-laden macrophages. Thus, in addition to RCA-1, ferritin antisera are useful as a microglia marker in formalin-fixed, paraffin-embedded sections.

Brain↗

PubMed1989

Organ distribution of proteinase-resistant prion protein in humans and mice with Creutzfeldt-Jakob disease.

We attempted to clarify the organ distribution of human and murine proteinase-resistant prion protein (PrPCJD) in Creutzfeldt-Jakob disease (CJD), and to measure the concentration of PrPCJD, using a semi-quantitative Western blot analysis. Human PrPCJD was restricted to the central nervous system, whereas murine PrPCJD was present in the central nervous system and in the lymphoreticular system at the end stage of CJD. PrPCJD concentration in the central nervous system of mice was almost identical to that of humans. The minimum wet weight of an organ with a positive reaction was 0.3 mg for brain, 1 to 3 mg for spleen, 3 mg for spinal cord, 3 mg for lymph node, 10 mg for thymus and 10 to 30 mg for intestine of the CJD-infected mice. There were no immunoreactions in purified PrPCJD fractions from 300 mg of spleen, lymph node, liver or peripheral nervous systems of humans, nor in 300 mg of liver, lung or kidney of CJD-infected mice. Within the limits of our method, the distribution of murine PrPCJD differed from that of human PrPCJD. Antibodies on the Western blot membrane from murine spleen PrPCJD fractions stained the kuru plaques in the CJD-infected mouse brain. Therefore, PrPCJD in the murine spleen probably shares the epitopes of the antigen in the murine kuru plaques. Although the immunological detection of PrPCJD does have limits of sensitivity, PrPCJD concentrations did correlate with infectivity titres in scrapie-infected or CJD-infected mice.

Animals↗