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Biomedical subjects

S Yokoi

Publications and source records attributed to S Yokoi.

At least 37 records · Page 2Linked to original sources
PubMed1991

A nuclear magnetic resonance spectroscopic and conformational study of eight pseudo-trehaloses (D-glucopyranosyl 5a-carba-D- and -L-glucopyranosides).

N.m.r. data (1H and 13C) are presented for eight pseudo-trehalose derivatives in which the D-glucopyranosyl moiety is alpha or beta and the 5a-carbaglucopyranoside moiety is alpha-D, beta-D, alpha-L, or beta-L. The differences in the chemical shifts and then n.O.e. effects have been correlated with the preferred conformations estimated from empirical force-field calculations (HSEA), which have been used to calculate the average parameters over the whole energy surface. Of the four alpha-D-glucopyranosyl derivatives, only that with a 5a-carba-beta-D-glucopyranoside moiety (3) was a substrate for glucoamylase.

Carbohydrate Conformation↗
PubMed1991

Degeneration of the corticopontine tract in olivopontocerebellar atrophy.

Nine cases of sporadic olivopontocerebellar atrophy [Déjérine-Thomas type, multisystemic atrophy (MSA)] were examined histologically and electron microscopically with special reference to the corticopontine tract. Five of nine cases showed degeneration of the myelinated nerve fibres in this tract. More severe degeneration of the fibres at the level of the pons than the crus cerebri indicates that degeneration of the fibres may start axodistally. Electron microscopy revealed selective involvement of large fibres in olivopontocerebellar atrophy, in contrast to unselective axonal atrophy in dentatorubropallidoluysian atrophy. The problem whether the degeneration of the tract is primary or secondary due to the loss of the pontine neurons remains open. We believe the former to be most likely. Degeneration of the corticopontine fibres should be added to the list of neuropathological findings in sporadic olivopontocerebellar atrophy.

Adult↗
PubMed1990

[An autopsy case of complicated form of spastic paraplegia with amyotrophy, mental deficiency, sensory impairment, and parkinsonism].

An autopsied case of complicated form of spastic paraplegia with many unusual clinical and pathological features is reported. Present case: a 31-year-old male. His parents are first cousins. Pregnancy and delivery had been unremarkable. Though he was mentally retarded, his physical development was normal. He was considered normal until age 10. He suffered from progressive disturbance in gait at the age of 11. He could not walk without assistance at the age of 22. Neurological examination revealed the following findings. He was obese and mentally deteriorated. Spastic paraplegia with increased tendon reflexes and pathological reflexes was prominent. Though slight sensory disturbance was present in the lower extremities, neither involuntary movement nor cerebellar ataxia was observed. In the age of late 20's, dementia, general muscular atrophy, and Parkinsonism developed. At the age of 30, he could not move by himself. He was apathic and indifferent, and showed forced laughing. Muscle tonus was flaccid because of general muscular atrophy and peripheral neuropathy. He died of acute gastric enlargement. Neuropathological findings were characterized by mal-development of the central nervous system (CNS) and the multisystem degeneration. There existed cerebral white matter hypoplasia with hypogenesis of the corpus callosum and ectopia of neurons of the cerebral and cerebellar cortex. Hypoplasia of melanin pigment was also observed in the remaining neurons of the substantia nigra and the locus ceruleus. Many neurons in the CNS included lipofuscin granules of variable shapes. Some of them showed clusters of several block-like inclusions which were green with luxol fast blue and cresyl violet stain.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Further observation of Japanese Creutzfeldt-Jacob disease with widespread amyloid plaques.

An autopsy case of Creutzfeld-Jacob disease with widespread amyloid plaques is reported. A 45-year-old Japanese man, whose father had died of a similar disease, had a 5-year illness characterized by progressive cerebellar signs. Mental changes and brain-stem signs developed in the late stage. Myoclonus frequently occurred. Akinetic mutism ensued. The autopsy revealed spongiform encephalopathy with widespread amyloid plaques and extensive degeneration of the white matter. This disease, Western Gerstmann-Sträussler-Scheinker disease and panencephalopathic type of Creutzfeld-Jacob disease are discussed.

Amyloid↗
PubMed1989

Fatty acid analysis of galactolipids and ganglioside in the brains of four cases of Nasu-Hakola disease.

A study was conducted on the fatty acid composition of cerebroside, sulfatide and ganglioside in the brains of 4 cases of Nasu-Hakola disease. The percentage of short carbon chain (C.16-C.18) nonhydroxy fatty acids of sulfatide in the cortex was much higher than that of the control and long-chain (C.24-) fatty acids showed a lower percentage. Sulfatide in the white matter was of the same tendency. The percentage of C.16:0 palmitic acid of ganglioside in the cortex was much larger than that of the control. Referring to the fatty acid composition of lipids in the literature, abnormalities of the fatty acid concentration, namely a high percentage of short-chain fatty acids of sulfatide and ganglioside in the cerebral cortex of the present cases, were confirmed.

Adult↗
PubMed1989

[The reappraisal study of the ultrastructure of Alzheimer's neurofibrillary tangles in three cases of progressive supranuclear palsy].

Progressive supranuclear palsy (PSP) is characterized by symptoms of disturbance of eye movement, nuchal rigidity, parkinsonism and subcortical dementia. Its pathology reveals that Alzheimer's neurofibrillary tangles (NFTs) are situated especially in the nuclei of basal ganglia and brainstem. It has been pointed out that NFTs observed in PSP are composed of straight tubules, the width of which is about 15 nm. This report is to reappraise the ultrastructure of NFTs observed in three cases of PSP. They are case 1; 69-year-old male, case 2; 62-year-old female and case 3; 65-year-old male. The clinical features of three cases were characterized by above-mentioned symptoms. Many NFTs were observed in brainstem of case 1 and 3. NFTs seen in brainstem of case 2 were in a small amount. In case 1 and 2, there were many NFTs in cerebral cortex, especially in parahippocampal gyri and other limbic areas. We examined the portions of frontal cerebral cortex, parahippocampal cortex, the basal nucleus of Meynert, oculomotor nucleus, substantia nigra, pontine nuclei and locus caeruleus of case 1, substantia nigra, red nucleus and inferior olivary nucleus of case 2, and Ammon's horn, globus pallidum, subthalamic nucleus, substantia nigra, oculomotor nucleus, pontine nuclei, locus ceruleus and inferior olivary nucleus of case 3. Ultrastructurally, NFTs of frontal cortex of case 1 consisted of twisted tubules and those of hippocampal and parahippocampal cortices of case 1 consisted of straight and twisted tubules, being observed separately in neurons. The NFTs of brainstem of case 1 and 2 were mainly composed of 12-17 nm straight tubules, and twisted tubules occasionally intermingled with straight components. In locus ceruleus of case 1, a single straight tubule could be seen in the bundles of twisted tubules. NFTs of case 3 were composed of only straight tubules, the width of which was about 15 nm. Twisted components were not observed in neurons of each nuclei of case 3. The characteristic ultrastructure of NFTs in PSP has been an appearance of straight tubules, however, twisted tubules were occasionally observed in this study. There are several case reports which demonstrated an appearance of both straight and twisted components. It is easily presumed that the process of aging takes part in the accumulation of twisted fibrils. However, it is now under consideration why twisted tubules are also observed in PSP. To summarize this study, the cases with many NFTs observed in widespread cerebral cortex may have a tendency to show both straight and twisted tubules.

Aged↗
PubMed1989

[Iron deposition in the brain of a case of the special type of hepatocerebral encephalopathy].

The histochemical demonstration of iron and the iron content was examined in the brain of a case of the special type of hepatocerebral encephalopathy (HCE). The patient had suffered from a liver disease since 36 years old. At 44 years old, she experienced the first attack of twilight state with flapping tremor. She had predilection for eating beans. Her personality gradually became euphoric with the recurrent episodes of unconsciousness. At 54 years old, she died of the complication of melena, renal insufficiency and pneumonia. The liver showed cirrhotic changes and iron content of liver was 0 or 1 after MacDonald's criterion scale. The histopathological findings of the brain showed the characteristic changes of HCE, which were incomplete softening and spongy state pseudolaminarilly extending in the deep layer of the cerebral cortex, the proliferation of the severely changed Alzheimer 2 type glia with or without intranuclear carmine positive substance. The deparaffinized sections, 20 mu in thickness, which were not fastened on slides were used for the histochemical study of iron, because iron deposits displaced inside of the brain tissues when the paraffin sections were fastened on slide glasses in the constant-temperature bath. The iron deposition was found in the central gyrus, superior temporal gyrus, medial and lateral occipito-temporal gyrus and middle temporal gyrus of occipital lobe. The iron accumulated in the ground substance, glia cell bodies, glia nuclei and unknown bodies in the 3-6 layers of cerebral cortex of these gyri. The iron accumulation demonstrated histochemically in other parts of the brain were group 1, 2 by Spatz, mammillary body, glia cell bodies in cerebellar white matter and pons.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain↗
PubMed1989

[A hip joint surgical planning system using 3-D images].

This paper describes a hip joint surgical simulation system using a three-dimensional image (X-ray CT images). We developed this system in cooperation with surgeons, and we have already applied it to several clinical examples. According to a surgeon who used our system for actual surgical plannings, most of the hip joint surgeries operated at the present time can be simulated. Our system has useful functions in order to plan surgeries such as interference check in movement of a bone and display of the attached surface of bone. We show an actual surgical planning process performed by the surgeon with our system.

Computer Simulation↗
PubMed1988

Three categories of the degenerative appearance of the human cerebellar dentate nucleus. A morphometric and morphological study.

This morphometric and morphological study demonstrates 3 categories (types A, B and C) of degenerative feature in the cerebellar dentate nucleus. Type A is characterized by neuronal loss, astrocytosis and granular and/or amorphous argyrophilic change around the neurons and neuronal processes, and this type was thought to be synonymous with the so-called grumose degeneration of the DN. Type B is characterized by extensive neuronal loss and astrocytosis without argyrophilic change, and it was considered that many diverse factors were responsible for type B. Type C features marked swelling of the neurons without neuronal loss, astrocytosis or argyrophilic change. The Purkinje cells were not involved in type A and C, but severely damaged in type B. Clinically, type A was observed in progressive supranuclear palsy and dentatorubropallidoluysian atrophy, type B extensively in many diseases including anoxic, toxic and infectious disorders, and type C in tardive dyskinesia manifesting with oral hyperkinesia. Types A and C may be more or less specific signs of degeneration of the dentate nucleus, whereas type B appears to be non-specific.

Adult↗
PubMed1988

[Lipid chemical study of an autopsy case of Nasu-Hakola disease].

Lipid chemical analysis of a case of membranous lipodystrophy (Nasu-Hakola disease) was reported. The case is a 43 yr-old man (at death). Onset of the disease was at his age of 10 when he had complained of leg pain. Since his age of 14, he had bone fractures of the lower extremities many times. At the age of 35, he was admitted to a hospital for the neurological examination. At that time, he showed exaggerated tendon reflexes and intension tremor of the upper extremities. He was euphoric and demented. His IQ was 31. Histological examination of biopsy specimen from the bone marrow revealed the typical membrano-cystic lesion. He had status epilepticus which was followed by comatous state for a week. The disease progressed gradually and he fell into decorticated state. He died at the age of 43. The total clinical course was 33 years. The brain weighed 680 g. Remarkable atrophy was observed in the whole brain. Loss of nerve cells in the upper layers of the cortex was marked. There were loss of myelin sheath and severe gliosis in the white matter. A part of the brain, liver and subcutaneous fat was frozen at the time of autopsy for the chemical examination. Quantitative determination of cholesterol, glycolipid, phospholipid, free fatty acid in the brain and liver, cholesterol, free fatty acid, triglyceride in the subcutaneous fat were carried out. Cholesterol was decreased about 33% in the cortex and 42% in the white matter in comparing with those of controls and the content of cerbroside in the white matter was about 1/3 of that of controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

A case of adult neuronal ceroid-lipofuscinosis with the appearance of membranous cytoplasmic bodies localized in the spinal anterior horn.

An autopsy case of adult neuronal ceroid-lipofuscinosis was examined. The clinical picture was characterized by gait disturbance, bulbar palsy and dementia. Histopathologically, diffuse neuronal loss was found throughout the central nervous system. The remaining neurons, predominantly in the motor nuclei of the spinal cord and brain stem, were swollen with storage material. Observed under the electron microscope the storage material showed various ultrastructures, such as lipofuscin-like bodies, pleomorphic lipid bodies, curvilinear profiles and finger-print profiles, in different regions of the central nervous system. In the ballooned neurons of the spinal anterior horn, many membranous cytoplasmic bodies and curvilinear profiles were intermingled within the same cell and were continuous with each other. Biochemically, N-acetyl neuraminic acid content was significantly increased in the spinal anterior horn. These findings suggest the localized increase of ganglioside in that region.

Gangliosides↗
PubMed1987

Nasu-Hakola's disease (membranous lipodystrophy).

An autopsy case of Nasu-Hakola's disease (membranous lipodystrophy) is reported. A 43-year-old Japanese man, whose parents were not consanguineous, had been suffering from frequent long bone fractures since the age of 10. Neuropsychiatric symptoms, which were characterized by euphoria, disturbance of attention and dementia, appeared at his thirties and generalized and/or localized seizures and apallial syndrome at the later stage. The neuropathology revealed diffuse leukoencephalopathy of the cerebrum. The peculiar aspects in this case were membranocystic changes in the lungs [Yagishita et al. Virchows Arch [A] 408:211-217 (1985)], diffuse degeneration of the cerebral cortex, chiefly in frontal and temporal lobes, and many axonal spheroids throughout the cerebral cortex. The ultrastructure of spheroids in the cerebral cortex demonstrated aggregations of mitochondria, dense bodies and minute concentric bodies and a small amount of neurofilaments.

Adult↗
PubMed1987

Tardive dyskinesia with inflated neurons of the cerebellar dentate nucleus. Case reports and morphometric study.

Four autopsied cases of tardive dyskinesia manifesting oral hyperkinesia revealed markedly inflated neurons in the cerebellar dentate nucleus (DN), which had not been described previously. The inflation of the neurons was proved to be statistically significant (P less than 0.01) by morphometric study. The nuclei were usually situated in the central portion of the cytoplasm. This inflated change was different from both central chromatolysis and grumose degeneration of the DN, typically observed in progressive supranuclear palsy and dentatorubropallidolysian atrophy, and seemed to be easy to miss without careful observation, since neuronal loss and gliosis were very mild in the DN. Among a few autopsied cases of tardive dyskinesia reported previously, degeneration of the DN was described in only two. It is believed, however, that the inflated neurons of the DN may not be so rare and may be related to the occurrence of some involuntary hyperkinesia, especially oral hyperkinesia following some neurotoxic disorders and/or neuroleptic medications.

Aged↗
PubMed1987

11C-glucose metabolism in manic and depressed patients.

The authors used positron emission tomography (PET) and 11C-labeled glucose to study 15 unmedicated patients with affective disorders and 7 control subjects. Diagnoses of affective disorders were based on DSM-III criteria, and symptomatology was evaluated by the Hamilton Rating Scale for Depression. Blood counts of 11C in both unipolar and bipolar patients did not differ from those in controls after oral administration of 11C-glucose. By contrast, brain counts of 11C in unipolar depressed patients were significantly lower, whereas those in bipolar manic patients were significantly higher, than in normal controls.

Adult↗