Biomedical subjects

F Ikuta

Publications and source records attributed to F Ikuta.

At least 109 records · Page 6Linked to original sources

PubMed1989

Pleiotropic molecular defects in energy-transducing complexes in mitochondrial encephalomyopathy (MELAS).

The extent of molecular defects in the mitochondrial energy-transducing system was examined in autopsied tissues of a 14-year-old male with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) in order to elucidate the underlying molecular and genetic abnormalities. The patient also had other multiorganic disorders: hypertrophic cardiomyopathy, nephrotic syndrome, and pseudohypoparathyroidism. Enzymic activities of complex I and IV were severely decreased, and those of complex III and V were mildly decreased in the mitochondria isolated from various tissues, but the severity of the deficiencies varied from tissue to tissue. In contrast, complex II and citrate synthase activities were normal or were decreased to a lesser extent than the enzymic activities of other complexes in all the tissues examined. These results suggest that the energy-transducing complexes, namely complexes, I, III, IV, and V, that contain mitochondrially synthesized subunits, were selectively affected. Immunoblot analysis demonstrated that the decreased enzymic activities were based on decreased contents of subunits in these complexes. The multiorganic manifestation of the disorder may result from wide and uneven distribution of abnormal mitochondria that have pleiotropic molecular defects in the energy-transducing complexes among the organs of the patient.

Acidosis, Lactic↗

PubMed1989

A Creutzfeldt-Jakob disease agent (Echigo-1 strain) recovered from brain tissue showing the 'panencephalopathic type' disease.

We used histologic evidence of degenerative changes in both the gray and white matter of the brain to diagnose a patient as having the panencephalopathic type of Creutzfeldt-Jakob disease (CJD). This type of CJD is relatively common in Japan, but not in North America or Europe. We recovered a transmissible pathogen (Echigo-1 strain) from an autopsy specimen of the patient's brain and passed it serially in Hartley guinea pigs. After a long latent period, it caused degenerative changes, mainly in the thalamic area of the guinea pig brain. On the 4th passage, a substrain emerged with a short latent period. When cross-transmitted to Golden Syrian hamsters, this substrain induced severe degeneration in both the thalamus and cerebral cortex. We compare our results with those for other experimental CJDs produced by other types of this disease.

Adult↗

PubMed1989

Lewy bodies in the enteric nervous system in Parkinson's disease.

We systematically studied the intramural nervous system of the alimentary tract in patients with Parkinson's disease and found that Lewy bodies were distributed widely in the Auerbach's and Meissner's plexuses. In the central nervous system, we recognized a striking similarity between the distribution of Lewy bodies and that of monoaminergic neurons. More recently, we have demonstrated that neuronal somata immunoreactive for tyrosine hydroxylase (TH) exist in the Auerbach's and Meissner's plexuses of normal humans. We consider a possible relation between these TH-immunoreactive catecholaminergic neurons to the occurrence of Lewy bodies in the enteric nervous system in Parkinson's disease. The affinity of Lewy bodies to the central and enteric neurons seems to be attributable to an unknown cell-biological characteristic apparently shared by both neurons.

Cytoplasm↗

PubMed1989

[The occurrence of tyrosine hydroxylase-immunoreactive neurons in a parietal lobe ganglioglioma].

A parietal lobe ganglioglioma in a 61-year-old male was investigated ultrastructurally and immunohistochemically, using antiserum against tyrosine hydroxylase (TH), a rate-limiting enzyme of the catecholamine (CA)-synthesizing pathway. On light microscopy, the tumor was composed mainly of neuronal and astrocytic cells. The neuronal cells had typical round vesicular nuclei with prominent nucleoli and showed abundant cytoplasm with variable amounts of Nissl bodies. Bi-nucleated neuronal cells were occasionally found. The astrocytic cells had eosinophilic cytoplasm of variable shapes and hyperchromatic small nuclei. Electron microscopy revealed numerous dense core vesicles (DCVs) in the neuronal cytoplasm and processes. Immunohistochemically, TH-immunoreactive neuronal cells were found sporadically in the tumor tissue. They were often binucleated or multinucleated. The presence of TH-immunoreactive neuronal cells in the present case is of interest in considering the origin of neuronal cells in ganglioglioma. Some investigators have considered that they may arise from the ectopic autonomic neuronal cell nests in view of the presence of DCVs. However, Gasper et al. have recently demonstrated the presence of TH-immunoreactive neurons in the normal human cerebral cortex. Therefore, it may also be possible to consider that TH-immunoreactive neuronal cells in this tumor originated from a certain dysgenetic focus containing such TH-immunoreactive neurons in the developmental stage.

Brain Neoplasms↗

PubMed1989

[An autopsy case of senile dementia with numerous neocortical senile plaques and preserved subcortical nuclei].

An 80-year-old retired teacher developed impairment of memory and suffered from delusions of theft. Four years later, she became disoriented as to person, time and situation, restless, began mutter to herself, and displayed night delirium and insomnia. She was subsequently diagnosed as having senile dementia of the Alzheimer type (SDAT). She died of bronchopneumonia and multiple metastases from breast cancer at the age of 85 years. Family history was non-contributory. The brain weighed 1,020 g and showed diffuse atrophy. Histologically, there was moderate loss of neurons in the cerebral cortex, which was accentuated in the frontal and temporal lobes. In addition, numerous senile plaques were observed in the neocortex and hippocampus. Several senile plaques were also found in the amygdala, innominate substance, neostriatum, claustrum, thalamus, hypothalamus and tegmentum of the mesencephalon. Neurofibrillary tangles (NFTs) were mostly restricted to the hippocampus and parahippocampal gyrus, their number being compatible with the patient's age. No obvious neuronal loss was noted in the nucleus basalis of Meynert, neostriatum, substantia nigra or locus ceruleus, which are well known to be involved in Alzheimer's disease and SDAT. Recently, Terry et al proposed a new disease concept, "SDAT without neocortical NFTs". The histopathology of the cerebral cortex in our patient was very similar, if not identical, to those observed in their patients. However, the above authors did not mention any subcortical changes, leaving the detailed neuropathological picture unclear. Tentatively, we classified the present case as senile dementia with numerous neocortical senile plaques and preserved subcortical nuclei.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1989

[Early development of cerebral blood vessels: on the morphological changes in endothelial cells during the fetal period in the rat brain].

Developmental changes of cerebral blood vessels in the rat fetal brain from the embryonic day 11 (E 11) to E 21 were chronologically observed with light and electron microscopes. Based on the fine structures the development of the blood vessels was divided into three successive stages: Stage I (from E 11 to E 21). The neural groove fused at the dorsal portion and transferred to the neural tube. Endothelial cells located only around the neural tissue, and showed a primitive nature in their cellular structures, such as immature nucleus and intracytoplasmic organelles. There were many pores at the thin portion of the cytoplasmic processes. Stage II (from E 13 to E 16). Matrix cells in the neural tube began to produce neuroblasts. These neuroblasts migrated from the matrix layer and were recognized as the migrating zone just outside the matrix layer. The formation of the migrating zone started at the ventrolateral portion and successively spread to the lateral neopallium and then to the medial one of the cerebrum. Perineural vessels invaded into the neural tissue at the ventrolateral portion and were distributed in the migrating zone and the matrix layer. It was the first appearance of the intraneural blood vessels, and the next invading seemed to follow the area which formed the migrating zone. The endothelial cells at this stage became to increase their cytoplasmic thickness and simultaneously to protrude many cell processes to the luminal and abluminal sides. Numerous large vesicles in the cytoplasm were also observed. Being associated with the vesicle formation the pores in the cytoplasm were rapidly decreased. Pericytes were recognized around the endothelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

[An autopsy case of thrombotic thrombocytopenic purpura--topography of the vascular lesion in the central nervous system].

We reported the pathological findings of an autopsy case of thrombotic thrombocytopenic purpura, with special reference to the topography of vascular lesion in the central nervous system. Amorphous eosinophilic, PAS-positive thrombi, endothelial proliferation and aneurysmal dilatation of affected vessels were prominent features in the visceral organs such as the heart, kidneys, liver, pancreas, adrenals, thyroid and alimentary tracts. Most of these vascular lesions were restricted to the arteriolar-capillary junctions. There were no thrombi in the lungs as reported previously. In addition, the thrombi were rarely seen in so-called portal vessels existed in the liver, pancreas and anterior pituitary gland. In the central nervous system, there were many vascular lesions similar to those of visceral organs in the cerebral gray matter, brain stem and cerebellar cortex. A few lesions were also seen in the white matter, subarachnoid space and choroid plexus. Many foci of chromatolytic neurons as well as a few petechial hemorrhages and minute infarcts were observed in the parenchyma. The characteristic of the vascular lesions in the cerebral and cerebellar cortex was the sites of thrombi. They were predominantly located at the bifurcation of arterioles, 20-50 microns in diameter, and were numerous in the third or fourth cortical layer of the cerebrum, and in the Purkinje cell layer of the cerebellum. Although the etiology of TTP is still unknown, the characteristic topography of vascular lesions suggests primary endothelial involvement in this disease.

Arterioles↗

PubMed1989

Cerebral glioblastoma with cerebrospinal fluid dissemination: a clinicopathological study of 14 cases examined by complete autopsy.

During the last 17 years, complete autopsies were performed on 51 patients who died of cerebral glioblastoma, and 14 were found to have dissemination by cerebrospinal fluid (CSF). In these 14 cases of glioma, the extent of intraparenchymal invasion by the primary tumor and the degree of seeding were studied in connection with histological findings and immunohistochemical staining for glial fibrillary acidic protein (GFAP) as the most reliable marker of astrocytic differentiation. From the findings obtained, the cases were divided into two groups. In one group, consisting of 7 gliomas, autopsy revealed intense seeding, despite only slight invasion by the primary tumor. Among these 7 extensively disseminated gliomas, 4 expressed almost no GFAP, 2 contained only a few GFAP-positive cells, and only 1 displayed an immunohistochemically high degree of astrocytic differentiation. Clinically, 6 of the 7 affected patients developed symptoms attributable to CSF seeding. In the other group consisting of the remaining 7 gliomas, only slight dissemination was seen, despite extensive infiltration of the primary tumor. Each of these 7 gliomas contained many GFAP-positive cells. None of the affected patients developed symptomatic seeding. This study shows the existence of two clinicopathologically distinct groups of disseminated cerebral glioblastomas and suggests that, regardless of morphological features, glioblastomas showing immunohistochemically poor astrocytic differentiation tend to shed tumor cells more vigorously but are less invasive at the primary site than those with many GFAP-positive cells. It is also suggested that, as a consequence, the former glioma type produces symptomatic seeding more frequently than the latter type.

Adult↗

PubMed1989

[The vestibular system and cerebellum in organic mercury intoxication; an otolaryngological and neuropathological investigation on 14 autopsy cases in Niigata].

The vestibular system consisting of vestibular ganglion, nerve and inferior, medial, lateral and superior nuclei and fastigial nucleus, cerebellar vermis, flocculus and hemisphere in 14 autopsy cases of methyl mercury intoxication in Niigata and 12 age-matched controls were examined neuropathologically. The findings were evaluated semiquantitatively, that is, -; normal, +/-; gliosis alone, +; loss of neurons or myelinated fibers less than about 40%, ++; loss of neurons from about 41 to 80%, ; loss of neurons more than about 81%. The results were compared to the records of the equilibrium function of those patients. The examinations on the equilibrium function revealed positive findings in the optokinetic and positional nystagmus, eye tracking, Mann or Stepping test in many of the patients. There were no remarkable histological alterations in the vestibular ganglion and nerve of the patients. Moderate and diffuse gliosis with slight shrinkage of neurons were observed in the vestibular and fastigial nuclei of all the patients. Slight loss of neurons in various vestibular nuclei was examined in only 4 patients. The fastigial nucleus showed no evident loss of neurons. In contrast, the cerebellum showed diffuse loss of Purkinje and granule cells, the degree of which was higher in the vermis than in the hemisphere and the flocculus. In the controls, the vestibular nerve and nuclei showed no remarkable alteration even in eight decade subjects. However, the Purkinje cells in the vermis seemed to have a tendency to decrease in aging. The dysequilibrium in the patient of methyl mercury intoxication did not seem to be correspond to the degeneration of the vestibular ganglion, nerve or nuclei.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1988

Endothelial fenestrae in the rat fetal cerebrum.

Ultrastructural analysis of endothelial cells during forebrain ontogenesis in the rat was carried out with special reference to endothelial fenestrae. Before the stage of neuroblast formation, i.e., at embryonic day 11 (E11) or E12, blood vessels were present only in the perineural mesenchymal tissue and possessed endothelial fenestrae in most of their cytoplasm. From E13 to E16, blood vessels invaded into the neural parenchyma, where the migrating zone was formed just outside the matrix layer. Peri- and intraneural endothelial cells during this period showed some peculiar ultrastructural changes characterized by cytoplasmic thickening, pseudopodial protrusions and the formation of large vesicles. In association with these changes, the fenestrae rapidly decreased in frequency, and had disappeared completely by E17. These results indicate that non-fenestrated endothelial cells are established in the developing rat cerebrum by E17 onwards.

Animals↗

PubMed1988

Selective decrease of large neurons in the neostriatum in progressive supranuclear palsy.

In order to evaluate the quantitative changes in the neostriatum in progressive supranuclear palsy (PSP), sections of the caudate head (CN) and putamen (PT) from 4 PSP patients were stained with Klüver-Barrera, and the cell body and nuclear area of the neurons were measured by a digitizer. Obtained results were compared to those of 6 age-matched control and 4 Alzheimer's disease and senile dementia of Alzheimer type (AD/SDAT) subjects which were previously reported. The number of large neurons (nuclear area greater than 101 microns 2) in PSP was about 40% (P less than 0.01) and 30% (P less than 0.01) of that of the controls in CN and PT, respectively. In contrast, the number of small neurons in PSP (nuclear area less than 100 microns 2) was well preserved. The values were quite similar to those in AD/SDAT. The implications and possible significance are discussed.

Aged↗

PubMed1988

Esthesioneuroblastoma: a nasal catecholamine-producing tumor of neural crest origin. Demonstration of tyrosine hydroxylase-immunoreactive tumor cells.

An esthesioneuroblastoma in a 16-year-old male was studied ultrastructurally and immunohistochemically, using antiserum against tyrosine hydroxylase (TH), a rate-limiting enzyme in the catecholamine-synthesizing pathway. Tumor cells were fairly uniform in appearance, showing scanty eosinophilic cytoplasm and round to oval hyperchromatic nuclei, and were arranged in nests and cords of various sizes. Ultrastructurally, individual tumor cells had well-developed cell organelles including polyribosomes, microtubules, intermediate filaments, centrioles, Golgi apparatus and mitochondria. Secretory-like granules were occasionally found, predominantly in the cell processes. Immunohistochemically, many tumor cells were shown to be immunoreactive for TH. This finding strongly suggested that the present tumor was capable of producing catecholamines and that it might be derived from certain sympathetic neuronal cell nests in the superior nasal cavity.

Adolescent↗

PubMed1988

Neuropathology of myoclonus epilepsy associated with ragged-red fibers (Fukuhara's disease).

The post-mortem findings are reported of two patients with myoclonus epilepsy associated with ragged-red fibers (MERRF, Fukuhara's disease), whose clinical findings have been described in detail previously. In addition to the mitochondrial myopathy, both patients had consistent lesions in the central and peripheral nervous systems: (1) degeneration of the dentatorubral and pallidoluysian systems, (2) spinal cord lesions resembling Friedreich's ataxia, and (3) degeneration of the substantia nigra, cerebellar cortex, inferior olivary nucleus, locus ceruleus, gracile and cuneate nuclei, and the pontine tegmentum. The nature and distribution of the lesions are different not only from the other mitochondrial encephalomyopathies but also from other known diseases. It is concluded that MERRF is a disease entity.

Adult↗

PubMed1988

A new type of cytoplasmic inclusion in human choroid plexus. A histochemical, ultrastructural and frequency study.

We described a new type of cytoplasmic inclusion in the choroidal epithelial cells of humans. The inclusions usually appeared as brown, round or elongated bodies with or without an inner core, ranging in size from 1.3 to 7.0 micron. Histochemically, they contained polysaccharides, proteins and compound lipids. Ultrastructurally, they were composed of finely granular and filamentous materials, which are densely packed in the inner core and less dense in the outer zone. The frequency study of the inclusions in 197 autopsied patients revealed that their occurrence had no correlation with the age or the disease category. It is concluded that the inclusions are a nonspecific, but peculiar, change of the choroidal epithelial cells, probably representing the morphological expression of a physiological or pathological alteration of the cellular metabolism at the single-cell level.

Choroid Plexus↗

PubMed1988

Parkinson's disease: the presence of Lewy bodies in Auerbach's and Meissner's plexuses.

We systematically studied the enteric nervous system of the alimentary tract in seven patients with Parkinson's disease. In all patients, characteristic inclusions histologically and ultrastructurally identical to Lewy bodies were found in Auerbach's and Meissner's plexuses. They were most frequent in the Auerbach's plexus of the lower esophagus. Lewy bodies were found in 8 out of 24 age-matched nonparkinsonian patients. However, they were obviously small in number. These findings clearly indicate that the plexuses are also involved in Parkinson's disease.

Aged↗

PubMed1988

Cytoarchitectonic investigation of the rat spinal cord following ethylnitrosourea administration at different developmental stages.

We examined the histological findings and cytoarchitectonic alterations in the rat spinal cord following matrix cell degeneration caused at different developmental stages, from neural plate formation through neuroblast generation. Ethylnitrosourea (ENU) 20 mg/kg body weight was administered transplacentally to the fetuses on the 10th embryonic day (E10) to 14th. The observations were made until the 21st postnatal day. Normally, mitoses were present scatteredly in the matrix cell layer of the neural plate or neural tube on E10 or E11, and gradually restricted to the dorsal portion of the alar plate as development occurred. The localization and number of degenerative cells as well as the site and degree of neuronal decrease in the completed dysgenetic spinal cord seemed to correlate with the topography and frequency of the mitoses in the matrix cell layer at the time of ENU administration. Disorder in the pattern of cytoarchitecture of neurons was not observed. The degree of hypoplasia of the white matter was proportional to the intensity of decrease of the spinal neurons. Aberrant myelinated fibers were not seen. No reactive gliosis, fibrosis or abnormal vascularization was observed at any time.

Animals↗

PubMed1988

Alterations of oligodendrocytes and demyelination in the spinal cord of patients with mitochondrial encephalomyopathy.

The spinal cords of 2 autopsied patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) were examined. Histologically, the spinal cords showed a spongy state due to the presence of distended myelinated fibers with enlarged periaxonal spaces. Ultrastructurally, the affected fibers showed extensive microvacuolation of the inner myelin sheath with occasional vesicular changes. The presence of macrophages near the degenerated myelin was a frequent finding. The stripping of myelin lamellae by macrophage was observed, with frequent appearance of denuded axons. Furthermore, prominent morphological changes were observed in oligodendrocytes. These findings indicate that demyelination, probably secondary to the degeneration of oligodendrocytes, occurs in the spinal cord of MELAS.

Adolescent↗

PubMed1988

Mitochondrial abnormalities in choroid plexus of Leigh disease.

Morphological study of the choroid plexuses in three patients with Leigh disease revealed a marked increase in the number of mitochondria in almost all of the choroidal epithelial cells. This finding is considered the morphological expression of a biochemical defect in the mitochondrial metabolism underlying Leigh disease, and the probable explanation for increased CSF levels of lactate and pyruvate in this disease.

Brain Diseases, Metabolic↗