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Biomedical subjects

K Oyanagi

Publications and source records attributed to K Oyanagi.

At least 55 records · Page 3Linked to original sources
PubMed1996

Disaggregation of polyribosomes in the spinal anterior horn cells in a patient with X-linked spinal and bulbar muscular atrophy.

The spinal anterior horn cells (AHCs) in a patient with X-linked spinal and bulbar muscular atrophy (SBMA) were examined by light and electron microscopy, giving special attention to alterations in the rough endoplasmic reticulum (ER). Seven age-matched subjects were used as controls. The patient with SBMA showed a severe decrease of AHCs, but the Nissl substance in the remaining AHCs appeared well preserved on light microscopy. Electron microscopy revealed a relatively well preserved parallel lamellar pattern of ER and marked disaggregation of the polyribosomes surrounding the ER in the remaining AHCs. These findings indicate that the Nissl substance was affected in spite of its light microscopic appearance in SBMA, and that the AHCs degenerate through disaggregation of the polyribosomes of the ER.

Anterior Horn Cells↗
PubMed1995

The anterolateral funiculus in the spinal cord in amyotrophic lateral sclerosis.

We carried out a morphometric study on the myelinated fibers in the anterolateral funiculus (ALF) and lateral corticospinal tract (LCS) in the cervical segment of the spinal cord of 13 patients with classic amyotrophic lateral sclerosis (ALS), 6 of whom had been on a respirator; 5 age-matched subjects were used as controls. The results obtained revealed that: (1) the fiber-size distributions of the myelinated fibers in the ALF and LCS of the control subjects had peaks at 2 microns; (2) there were marked and significant losses of large myelinated fibers in the ALF and LCS of ALS patients; (3) the patients who required respirator support showed more severe degeneration in the ALF than those who required none; and (4) the degree of myelinated fiber loss in the LCS did not correlate with either the illness duration or the history of respirator use.

Aged↗
PubMed1995

Evidence for transneuronal degeneration in the spinal cord in man: a quantitative investigation of neurons in the intermediate zone after long-term amputation of the unilateral upper arm.

Does transneuronal degeneration occur in the neurons of the spinal intermediate zone following degeneration of the anterior horn cells in man? To investigate this possibility, we carried out a quantitative examination of neurons in the cervical intermediate zone of a 56-year-old man who had suffered accidental amputation of the right upper arm 38 years prior to death. Recently, we reported that the cervical anterior horn cells of this patient were reduced in number not only on the amputation side but also on the spared side. The present study revealed that medium-sized neurons in the cervical intermediate zone, which were considered to be internuncial neurons, were decreased in number on both the amputation and the spared sides, but less so on the spared side. These findings indicate that retrograde transneuronal degeneration occurs in the internuncial neurons following degeneration of the anterior horn cells caused by amputation. Sequentially to this, degeneration of the commissural neurons in the intermediate zone secondary to that of the internuncial neurons may induce degeneration of the neurons in the intermediate zone and the anterior horn cells on the spared side.

Amputation, Traumatic↗
PubMed1995

Genetic association of the very low density lipoprotein (VLDL) receptor gene with sporadic Alzheimer's disease.

A specific isoform of apolipoprotein E has been associated with the accelerated rate of disease expression of sporadic Alzheimer's disease (AD) and late-onset familial AD (FAD). An earlier age at onset has also been demonstrated in familial AD patients with mutations in the amyloid precursor protein (APP) gene (APP717 and APP670/671)13 carrying the APOE epsilon-4 allele compared to those who do not, but not in familial AD patients with APP692 or 693 mutations, or in chromosome 14-linked familial AD patients. Hypothesizing that receptors for apoE-containing lipoproteins act as a potential risk factor for AD, we performed an association study using a polymorphic triplet (CGG) repeat in the gene for the VLDL receptor (VLDL-R), a receptor for apoE-containing lipoproteins. The frequency of the 5-repeat allele was significantly higher in all of the Japanese sporadic AD patients (P < 0.02) than in the Japanese controls. Moreover, the odds ratio was significantly increased in the AD patients homozygous for the 5-repeat allele (OR = 2.1, 95% CI = [1.1-4.2]). Multiple logistic regression analysis reveals that the relative risk conferred by the presence of two copies of the 5-repeat allele and at least one copy of the APOE epsilon-4 allele is 8.7 (95% CI = [2.9-25.8]). Our results suggest that the VLDL-R gene is a susceptibility gene for AD.

Alleles↗
PubMed1995

Isolated persistent hypermethioninemia.

New information has been obtained on 30 patients with isolated persistent hypermethioninemia, most of them previously unreported. Biopsies to confirm the presumptive diagnosis of partially deficient activity of ATP: L-methionine S-adenosyltransferase (MAT; E.C.2.5.1.6) in liver were not performed on most of these patients. However, none showed the clinical findings or the extreme elevations of serum folate previously described in other patients with isolated hypermethioninemia considered not to have hepatic MAT deficiency. Patients ascertained on biochemical grounds had no neurological abnormalities, and 27/30 had IQs or Bayley development-index scores within normal limits or were judged to have normal mental development. Methionine transamination metabolites accumulated abnormally only when plasma methionine concentrations exceeded 300-350 microM and did so more markedly after 0.9 years of age. Data were obtained on urinary organic acids as well as plasma creatinine concentrations. Patterns of inheritance of isolated hypermethioninemia were variable. Considerations as to the optimal management of this group of patients are discussed.

Adolescent↗
PubMed1995

[Neuropathology of syringomyelia].

Eighteen autopsy cases of syringomyelia were studied neuropathologically. In 5 cases associated with Chiari type I malformation, the syrinx was irregular in shape and communicated with the subarachnoid space at the entry zone of the posterior nerve roots. The central canal above the level of the syrinx was patent in 2 but closed in 3 out of 5 cases. In cases associated with Chiari type I malformation, communication between the syrinx and the subarachnoid space was considered to play an important role in the pathogenesis of syringomyelia. In 6 cases associated with Chiari type II malformation, the syrinx central canal, and the central canal was patent from the 4th ventricle to the syrinx in all cases. In these cases, direct continuity between the 4th ventricle and the syrinx was essential for the development of the syrinx. In cases associated with posterior fossa or spinal canal tumors, the local circulatory disturbance and/or edema due to the tumors were thought to cause the syrinx.

Adolescent↗
PubMed1994

Corticobasal degeneration: etiopathological significance of the cytoskeletal alterations.

We have studied brain tissues from three patients with corticobasal degeneration (CBD) histologically, ultrastructurally and immunohistochemically. Ballooned neurons in the cerebral cortex and severe degeneration of the substantia nigra were observed in them all and weakly basophilic neurofibrillary tangles (NFTs) were distributed widely in the basal ganglia and brain stem. Ultrastructural examination demonstrated that the NFTs comprised characteristic 15-nm-wide straight tubules, which showed positive immunohistochemical staining with an antibody against tau, but not ubiquitin. Tau-immunoreactive neuronal cell bodies without NFTs also were found in the cerebral cortex and subcortical nuclei, predominantly in the brain stem, and the greatest number of tau-positive glial inclusions occurred in the cerebral gray and white matter of the pre- and post-central gyri. These inclusions comprised tubular structures with diameters of about 15 nm and were localized in the oligodendroglial cellular cytoplasm and processes. These findings indicate that there is a close cytoskeletal pathological relationship between CBD and progressive supranuclear palsy.

Aged↗
PubMed1994

Motor neuron disease with multi-system involvement presenting as tetraparesis, ophthalmoplegia and sensori-autonomic dysfunction.

We carried out a postmortem examination on two Japanese patients, 64- and 80-year-old men whose survival was prolonged with an artificial respirator. They had no family history of neuropsychiatric disorders and were suspected, clinically, as having a motor neuron disease that differed from amyotrophic lateral sclerosis (ALS). As well as upper and lower motor neuron impairment, they showed a variety of symptoms, such as sensory disturbances, hypohidrosis, impotence, ophthalmoparesis and/or atonic neurogenic bladder, and their protein content in cerebrospinal fluid was elevated markedly. Pathological examination revealed the following extensive nervous system involvement: (1) the upper and lower voluntary motor systems, including the IIIrd, IVth and VIth cranial nerve nuclei: (2) the reticular formation and its major afferent pathways; (3) the vestibulospinal and tectospinal systems; (4) the spinocerebellar system and the exteroceptive somatic afferent pathways; (5) the dentatorubral and pallidoluysian systems; and (6) the substantia nigra, locus ceruleus and intermediolateral and Onufrowicz's nuclei. Neither Bunina bodies, Lewy body-like hyaline inclusions nor ubiquitin immunoreactive skein-like structures were observed. The distribution of the lesions was quite different from that in patients with ALS and the other known related diseases. Recently, seven autopsied cases with clinical and histopathological similarities to our patients have been reported in Japan. Our conclusion is that our two and these seven patients should be classified as having a new motor neuron disease entity, which can be is differentiated from ALS.

Aged↗
PubMed1994

The neostriatum and nucleus accumbens in parkinsonism-dementia complex of Guam: a pathological comparison with Alzheimer's disease and progressive supranuclear palsy.

The neostriatum, nucleus accumbens and basal nucleus of Meynert (bnM) in the parkinsonism-dementia complex of Guam (Guam PDC) were examined immunohistologically, ultrastructurally, quantitatively and topographically, and the results were compared with those in Alzheimer's disease (AD) and progressive supranuclear palsy (PSP). Compared to neurologically normal controls, the number of large neurons in Guam PDC was reduced by approximately 70% in the caudate nucleus and putamen and by more than 90% in the nucleus accumbens. The decreased number of large neurons in the neostriatum was significantly correlated to that in the bnM. The remaining large neurons and many of the medium-sized neurons in the neostriatum and nucleus accumbens were immunopositive for tau protein and contained varying amounts of 21- to 25-nm-wide paired helical filaments (PHFs) admixed with straight tubules. Curly fibers and circularly arranged reactive astrocytes were seen in the nucleus accumbens of many PDC patients. Collectively, these findings, which are similar in part to those of AD and differ from those of PSP, suggest that the large neurons in the neostriatum and nucleus accumbens in Guam PDC degenerate through PHF formation, and that extremely severe loss of large neurons in the nucleus accumbens may be linked to marked degeneration of the limbic and ventral tegmental areas and nucleus dorsal raphe.

Adult↗
PubMed1994

Amyotrophic lateral sclerosis of Guam: the nature of the neuropathological findings.

To elucidate the fundamental differences and similarities of the neuropathological features and etiopathogenesis of the amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia complex (PDC) of Guam, we conducted a topographic, quantitative and histological investigation of tau-containing neurons, neurofibrillary tangles (NFTs), Bunina bodies and ubiquitinated inclusion bodies in 27 non-ALS non-PDC Guamanian subjects, as well as 10 Guam ALS patients, 28 PDC patients, and 5 patients with combined ALS and PDC (ALS-PDC). The topographic distribution of NFTs was basically the same in each disease and also in the non-ALS non-PDC group. There were relatively few, if any, NFTs in non-ALS non-PDC subjects and ALS patients, but there were many, especially in the frontal and temporal cortex, in Guam PDC and ALS-PDC patients. The histological and ultrastructural features of Bunina bodies in Guam ALS and ALS-PDC patients were similar to those reported in classic ALS. The ratio of occurrence of the inclusion in Guam ALS and ALS-PDC patients was similar to that reported so far in classic ALS. Ubiquitinated skein-like inclusion bodies were observed in the spinal anterior horn cells in Guam ALS and ALS-PDC patients. These findings indicate that classic ALS does exist on Guam, that NFTs in Guam ALS patients are merely a background feature widely dispersed in the population, that the mechanism of neuronal degeneration of Guam ALS is basically different from that of PDC, and that Guam ALS occurs initially are classic ALS.

Adult↗
PubMed1994

Topographic investigation of brain atrophy in parkinsonism-dementia complex of Guam: a comparison with Alzheimer's disease and progressive supranuclear palsy.

The topographic distribution of brain atrophy in nine patients with parkinsonism-dementia complex of Guam (Guam PDC) was evaluated quantitatively, and compared with that in six Japanese patients with Alzheimer's disease or senile dementia of Alzheimer type (AD), five Japanese patients with progressive supranuclear palsy (PSP), and nine Japanese control subjects. Characteristic features of Guam PDC were as follows: (1) severe atrophy of the frontal and temporal cortex with relative preservation of the white matter; (2) atrophy of the tectum, tegmentum and cerebral peduncle of the midbrain, and (3) atrophy of the tegmentum and base of the upper pons. In contrast, sectional areas of the tectum and cerebral peduncle of the midbrain were relatively well preserved in PSP, while in AD there was no significant atrophy in the brain stem.

Aged↗
PubMed1993

Widespread multiple system degeneration in a patient with familial amyotrophic lateral sclerosis.

We report a 57-year-old woman with familial amyotrophic lateral sclerosis (ALS) with posterior column involvement of 11 years duration. The patient had been on a respirator for more than 5 years before death. In addition to the well established pathology of this form of familial ALS, there were obvious degenerative changes in the brainstem tegmentum, including the reticular formation, cerebellar cortex, dentate and red nuclei, thalamus and mammillary body. Of great interest in this case was intracytoplasmic accumulation of neurofilaments in the remaining neurons in these areas, some of which, for instance, those in the oculomotor and abducens nuclei, still showed only minimal loss. This patient had survived considerably beyond the point of respiratory failure, which is the final stage in the natural history of the disease. We considered that in this patient the underlying degenerative process of the disease had become manifested in wider areas than recognized previously during the prolonged clinical course due to respiratory support. However, whether or not such widespread degeneration would occur in all patients with this disease who survive longer with the help of respiratory support awaits further studies.

Amyotrophic Lateral Sclerosis↗
PubMed1993

A quantitative pathological investigation of the cervical cord, roots and ganglia after long-term amputation of the unilateral upper arm.

A pathological study was conducted on an autopsied patient who had undergone amputation of the right arm at the level of the shoulder 38 years prior to death. The numbers of anterior horn cell, spinal ganglion cells and myelinated fibers in the anterior and posterior spinal roots at the cervical segments were examined quantitatively and compared with those of age-matched control subjects. On the amputation side, anterior horn cells, spinal ganglion cells and large myelinated fibers of the anterior and posterior roots were decreased in number. In addition, on the spared side, the medium-sized neurons of Rexed's lamina IX were shrunken, or decreased in number, and the number of small- and medium-sized myelinated fibers in the anterior roots was decreased. These findings indicate that the long-term effects of axonal amputation induce retrograde degeneration of the anterior horn and spinal ganglion cells on the amputation side, resulting in atrophy and a decrease of medium-sized neurons in the anterior horn even on the contralateral, spared side.

Amputation, Traumatic↗
PubMed1993

The intermediolateral nucleus in sporadic amyotrophic lateral sclerosis.

Histological and morphometrical observations of the intermediolateral nucleus (IML) at the levels of the upper and lower thoracic segments (T2 and T9) were carried out in 18 patients with sporadic amyotrophic lateral sclerosis (ALS) and 15 age-matched control subjects. Of the 18 ALS patients 6 had been on a respirator before death. No Bunina bodies were found in the IML neurons in either the ALS patients or the control subjects. Only a small number of spheroids were encountered rarely in the IML in both the patients and controls. The number of neurons in the IML in the non-respirator-supported ALS patients were reduced at T2, but well preserved at T9 compared with the control subjects. In the respirator-supported ALS patients, there was a marked reduction of IML neurons at both T2 and T9. Considering the absence of direct synaptic contacts with anterior horn cells, these neurons, without the formation of Bunina bodies, appeared to be involved primarily in the disease process in sporadic ALS.

Adult↗