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Biomedical subjects

N Amano

Publications and source records attributed to N Amano.

At least 145 records · Page 8Linked to original sources
PubMed1983

beta-Galactosidase-neuraminidase deficiency (galactosialidosis): clinical, pathological, and enzymatic studies in a postmortem case.

Three male siblings in a Japanese family were affected with beta-galactosidase-neuraminidase deficiency (galactosialidosis). One patient died at 45 years of age, and postmortem liver and brain tissues were studied enzymatically. The residual activity of neuraminidase was relatively high in these tissues. Neuraminidase activity did not change in the tissues after repeated freezing and thawing of the homogenates, whereas this enzyme in control tissues lost 30 to 60% of its activity. There was a profound deficiency of beta-galactosidase in the tissues of the patient. Michaelis constant, pH profiles, and cryostability were identical for the patient and control patients. Cathepsin B was moderately increased in activity in the patient's tissues.

Adult↗
PubMed1983

Pleomorphic intra-neuronal polyglucosan bodies mainly restricted to the pallidium. A case report.

rare case with pleomorphic intra-neuronal polyglucosan bodies is reported. A 45-year-old man died of gastric carcinoma with extensive visceral involvement. The autopsy showed numerous intra-neural pleomorphic PAS-positive deposits reminiscent of Bielschowsky bodies in the lateral segments of the pallidum, substantia nigra, and brain stem on both sides. Their histochemical properties were consistent with polyglucosan. The bodies were ultrastructurally composed of filamentous structures and seen in perikarya, axons, and dendrites. Occasionally, spotty electron-dense material was seen in the center of the bodies. The filaments were selectively stained with thiocarbohydrazide method after Thiéry, indicating their chief component as glucose polymers. The bodies are compared with Bielschowsky bodies, Lafora bodies, corpora amylacea, and related bodies, and their nature and significance are briefly discussed.

Axons↗
PubMed1983

Neuropathological findings of an autopsy case of adult beta-galactosidase and neuraminidase deficiency.

An autopsy case of a Japanese male with familial beta-galactosidase and neuraminidase deficiency is reported. The clinical picture was characterized by adult onset, a gargoyle-like face, cerebellar ataxia, myoclonus, convulsions, retinal degeneration and cortical blindness. Histopathologically, most neurons seemed to have become degenerated in the whole cerebral cortex. Moreover, the calcarine cortex appeared spongy with depopulation of nerve cells. Stuffed neurons or neuronal storage changes were found throughout the brain, especially in the motor nuclei of the spinal cord and brain stem. The inclusions in the stuffed neurons revealed various profiles on the electron microscope. They were composed of membranous lamellar and/or multilamellar structures, often accompanying vacuoles and reminiscent of lipofuscin-like profiles.

Age Factors↗
PubMed1983

R wave changes in patients with myocardial infarction during treadmill stress testing.

A graded multistage treadmill exercise test was performed on 78 patients with myocardial infarction (65 males and 13 females, ranging in age from 30 to 76). The amplitude of the R wave in CC5 was measured at rest and during the periods of peak exercise. The exercise-induced R wave changes were classified into 3 groups: increased, 39.1%; no changes, 39.7% and decreased, 22.2%. Acute attacks of myocardial infarction were more severe in the patients whose R wave decreased during exercise than in those whose R wave increased. Heart rate, blood pressure and pressure rate products were not different among the groups. However, oxygen consumption was greater in the R-increased group than in the R-decreased group. Therefore, an increase in R wave amplitude during exercise in post-myocardial infarction patients indicates a good efficiency of the myocardium and skeletal muscles. Exercise-induced changes of the mean electrical axes of the transverse plane were significantly related to changes of the R wave amplitude in CC5 (r = 0.50, p less than 0.001). Therefore, change in the transverse plane axis is one of the important determinants of exercise-induced R wave changes.

Adult↗
PubMed1983

Exercise capacity of the patients with myocardial infarction.

This study was conducted to investigate the functional capacity in postmyocardial infarction. Eighty-four multistage treadmill exercise tests were performed on 60 patients, none of whom had had any formal rehabilitation or regular exercise. There were 50 men and 10 women, ranging in age from 30 to 81 with an average age of 60. The time interval between the acute attack and the exercise test ranged from one month to 9 years. Even though severe infarction affects the exercise capacity for a long time after an acute attack, its effect on cardiac function was more obvious than that on physical capacity. Age was the most important determinant of physical capacity, and the slope of decreasing physical capacity with age in patients with infarct was the same as that in normal subjects. Cardiac function also decreased with age. However, during the early recovery phase, cardiac function was influenced by the severity of infarction and the influence of age could not be established. There was no significant correlation between early ambulation and physical capacity. The beneficial effects of early ambulation may be lost if physical activity is discontinued for some time after the acute attack. The physical capacity increased 2-3 years after the acute attack, but myocardial function did not change significantly.

Adult↗
PubMed1982

Response characteristics of primary periodontal mechanoreceptive neurons in the trigeminal mesencephalic nucleus to trapezoidal mechanical stimulation of a single tooth in the rat.

The response characteristics of primary periodontal mechanoreceptive neurons in the trigeminal mesencephalic nucleus (MeNV) were studied by changing the rate and magnitude of trapezoidal pressure applied to the upper incisor in very lightly anesthetized rats. Using a metal microelectrode in the MeNV either for recording or for stimulation, the projection site of primary afferents in the anterior superior alveolar nerve innervating the upper incisor was determined. Its stereotaxic coordinates were 1.0--2.0 mm posterior to the interaural plane and 1.2--1.3 mm lateral to the mid-sagittal plane, corresponding to the caudal part of the MeNV. From this site of 19 animals, single unitary activity from 41 primary periodontal mechanoreceptive neurons was recorded, which were identified by: (1) the constant, brief latency of 1.0--4.0 ms (2.0 +/- 0.6 ms, mean +/- S.D.) from the onset of single tooth tapping; (2) the wave forms of their unitary spike responses; and (3) the ability to follow faithfully trains of repetitive stimuli applied to the anterior superior alveolar nerve at rates of more than 100 Hz for 2 s. The responses of the identified primary mechanoreceptive neurons in the MeNV were tested for repetitive tapping and trapezoidal pressure to the ipsilateral upper incisor. The highest frequency of one-to-one following was observed in repetitive tapping at 100 Hz. All of the 27 tested neurons exhibited such very rapid adaptation as to show only on-off responses to trapezoidal pressures, and did not respond at all unless the pressures were applied more rapidly than 0.6 Newtons/s (N/s). In most of these neurons, the number of evoked spikes was greater in on-responses than in off-responses, and the number and frequency of spikes were increased with an increase in the rate of pressure application. But in several neurons only one spike was triggered even when the pressures were applied at the rate of more than 83.1 N/s.

Afferent Pathways↗
PubMed1981

Reappraisal of the fine structure of Alzheimer's neurofibrillary tangles.

Alzheimer's neurofibrillary tangles were studied by electron microscopy. The study includes four cases of Alzheimer's disease, two cases of atypical senile dementia, and one case of progressive supranuclear palsy. In Alzheimer's disease the tangles were composed of either straight filaments or paired helical filaments. In progressive supranuclear palsy the tangles were composed of 15 nm straight filaments or helical filaments. A few straight filaments were mixed with paired helical filaments. In atypical senile dementia, both straight and paired helical filaments comprised the tangles and one type of filaments appeared to intermingle with the other in the same neurons.

Adult↗
PubMed1980

Atypical senile dementia with widespread Lewy type inclusion in the cerebral cortex.

An atypical case of senile dementia is reported which shows senile plaques, neurofibrillary tangles, granulovacuolar degeneration, and Hirano bodies and numerous Lewy bodies in the pigmented neurons of the brain stem, and Lewy-body-like inclusions in the cerebral cortex. The inclusions in the cerebral cortex had a strong resemblance to the Lewy bodies in the substantia nigra, though a few histochemical and ultrastructural differences were observed. The pathological findings were unexpected since the parkinsonian syndrome was not recognized.

Brain Stem↗
PubMed1980

The fine structure of neurofibrillary tangles in a case of atypical presenile dementia.

The neurofibrillary tangles in a case of atypical presenile dementia were studied by electron microscopy. The tangles consisted of 2 types of tubule: one straight, measuring about 15--20 nm in width, the other twisted. Both types of tubule appeared separately in each neuron; however, occasionally twisted tubules seemed to be distributed among the straight tubules. The implications of these findings are briefly discussed.

Alcohol Amnestic Disorder↗
PubMed1979

Crystalloid inclusions reminiscent of Hirano bodies in autolyzed peripheral nerve of normal wistar rats.

In a study of experimental autolysis of peripheral nerves of normal Wistar rats, crystalloid inclusions similar to Hirano bodies were observed. They occurred in the nuclei and cytoplasms of Schwann cells and in myelinated axons. They first developed after a 12-h autolysis and increased in number and size with time. Their fine structure, localization, and morphogenesis are discussed in relation to the autolysis of the cellular organelles.

Animals↗