Biomedical subjects

N Amano

Publications and source records attributed to N Amano.

At least 91 records · Page 5Linked to original sources

PubMed1990

An autopsy case of peroneal muscular atrophy with rigidity and tremor. Ultrastructural and systematic morphometrical studies on peripheral nerves.

An autopsy case of hereditary peroneal muscular atrophy (PMA) with rigidity and static tremor is presented. The patient developed slowly progressive distal muscular atrophy of the legs at the age of 15 years. By the age of 52 years, PMA became marked associated with pes cavus, and tremor and rigidity of the extremities were noted. Motor and sensory conduction velocities gradually depressed and lost near the end of his life. At autopsy, the major neuropathological abnormalities involved the peripheral nervous systems, and were characterized by axonal atrophy and loss of myelinated fibers. These changes involved both the proximal and distal nerves, being more severely affected in the distal. The pathological changes in other regions of the nervous systems were mainly confined to the spinal cord, dorsal ganglia and spinal nerve roots, and pigmented neurons in the brain stem. Morphometrically, the total fascicular area was much smaller than in control, but the total number of myelinated fibers greatly outnumbered that of control 75,200 to 48,200 at the proximal sciatic nerve and then gradually decreased towards the periphery; however, even in the distal sural nerve, the total number of myelinated fibers exceeded that of control (6820 to 5469). Thus, the density of myelinated fibers were much higher, being 1.5 to 2 times greater, than in control. Its abrupt decline at the distal nerve might account for neurogenic atrophy of the distal musculature. Unmyelinated fibers were slightly increased in density and not atrophic. This case is unique in its clinicopathology and does not belong to any subtypes of PMA including "neuronal plus".

Adult↗

PubMed1990

[Studies on oral sensation in patients with implant denture. 4. Ability of hardness discrimination].

The ability of hardness discrimination in 11 implant denture wearers was compared with those in 10 bridge wearers and 11 normal dentate subjects. The hardness discrimination was tested using silicone rubber blocks having rubber hardness that ranged at intervals of 10 degrees from 30 degrees to 70 degrees. Using a rubber block with rubber hardness of 50 degrees as a standard, the ability of discriminating rubber blocks of different hardness was examined. All the three groups examined had excellent ability of discriminating the rubber blocks of rubber hardness of 30 degrees and 70 degrees from the standard block. The ability to discriminate the rubber block of rubber hardness of 40 degrees from the standard block was only slightly lower than but almost the same as the ability of discriminating the hardness of 30 degrees and 70 degrees in all the three groups. However, the ability of discriminating the rubber block of rubber hardness of 60 degrees from the standard block was significantly lower in the implant denture wearers, compared to the normal dentate subjects and bridge wearers.

Dental Implants↗

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↗

PubMed1990

[An autopsied case of alcoholic cerebellar degeneration with spastic paraplegia and neuropathy].

A 45 year-old-female was admitted to Kanagawa Rehabilitation Center because of marked spastic paraplegia. There was no family history of neurological diseases. She had been drinking a great excess of alcohol since twenty years of age. Though she noticed the unsteadiness of gait several years prior to the admission, she had not been examined. On admission neurological examination revealed pyramidal weakness of both legs, and slight sensory impairment in distal part of the lower extremities. But she had neither difficulty in speech nor abnormal findings in the upper extremities. Her mentality was well preserved. Though computed tomography revealed cerebellar cortical atrophy, no signs of cerebellar impairment could not be found except spastic paraplegia. Blood chemistry failed to reveal liver dysfunction. There was no pernicious anemia. These symptoms were almost stationary until her death. At the age of 53, she died of gastric cancer. Postmortem examination disclosed marked degeneration of cerebellum and spinal cord. Cerebellar cortical degeneration, which was characterized by involvement of all layers of the cortex, showed unique distribution. The lingula, central lobule, culmen, superior portion of declive, anterior lobules and anteromedial half of simple lobule were severely degenerated, while other lobules were spared excluding moderate degeneration in inferomedian portion of the hemisphere. These cortical degeneration was prominent much more in vermis than in hemisphere. There was a mild myelin pallor in the lamellar white matter and slight fibrous gliosis. In the dentate nucleus, there were moderate neuronal loss with gliosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗

PubMed1990

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--1. Introduction].

We have developed a new method of total intravenous anesthesia with droperidol, fentanyl and ketamine and have administered it to more than 400 surgical patients, ranging in ages from 4 to 80 years. Cardiac and neurosurgical patients were excluded. After establishing a routine monitoring, droperidol 0.06-0.1 ml.kg-1 was slowly given. After 5 minutes, fentanyl 1-2 micrograms.kg-1 and ketamine 1.0-1.5 mg.kg-1 were slowly administered intravenously. Trachea was intubated following intravenous succinylcholine. A total dose of 5-15 micrograms.kg-1 of fentanyl was given intravenously with a continuous infusion of ketamine 2 mg.kg-1.hr-1 during surgical procedure. Air and O2 (FIO2 0.30-0.35) were given and muscle relaxation was achieved with necessary dose of intravenous pancuronium or vecuronium and no inhaled anesthetic was given. Total intravenous anesthesia has many advantages such as no air pollution in the operating theatre, empty bowels, no organ (hepato-renal) toxicity, good peripheral perfusion and low cost, while this method has several disadvantages to overcome such as hypertension. There are many anesthetic agents for total intravenous anesthesia. However, sufentanil, alfentanil and propofol are not available. Droperidol, fentanyl and ketamine are the best combination for this purpose in Japan so far.

Adolescent↗

PubMed1990

[Accurate and simplified determination of ketamine in plasma by gas chromatography mass spectrometry].

An accurate and simplified method has been developed for determination of ketamine in human plasma using gas chromatography and electron impact mode mass spectrometry with selected ion recording from 0.5ml of plasma. Standards and samples of plasma underwent the same procedure of two step extraction by methanol. Ketamine concentrations in the plasma were determined from the peak in the selected ion profile of ketamine (m/e: 237). Standard curve was linear with the increasing amount of ketamine (0.63-5.0 micrograms.ml-1) in plasma with mean CV = 5.2% mean RR = 63.8% and r = 0.998. The concentration of ketamine in plasma ranged from 1.6 micrograms.ml-1 to 2.5 micrograms.ml-1 during ketamine anesthesia (2mg.kg-1.h-1) in a surgical patient.

Gas Chromatography-Mass Spectrometry↗

PubMed1989

Innervation of the tooth pulp by the mesencephalic trigeminal nucleus in the cat: a retrograde horseradish peroxidase study.

HRP was applied to the tooth pulp of 8 cats. Six were subjected to postoperative administration of the anti-inflammatory drug, prednisolone, whereas the remaining two were not. In all prednisolone-treated cats, labeled neurons were found in both the mesencephalic trigeminal nucleus and trigeminal ganglion, ipsilaterally. On the other hand, no labeled neurons were observed in the mesencephalic nucleus in cats receiving no steroid.

Animals↗

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

Distribution and morphology of brain stem plaques in Alzheimer's disease.

The morphology, incidence and distribution of senile plaques in the brain stem were examined in 15 cases of Alzheimer's disease, using mainly the Methenamine-Bodian method. The plaques were found in all cases and were grouped into three types according to their morphology. They were not randomly scattered in the brain stem, but had a distribution common to all cases. There were numerous plaques in the periaqueductal gray, superior colliculus, fourth-ventricle floor and superior central nucleus. The plaques were also found less abundantly in the reticular formation, substantia nigra, pontine nucleus and inferior olivary nucleus. There was a tendency for certain plaque types to be associated with specific regions. In the familial cases, the plaques tended to occur even in the regions where they were rare in other cases. The capillaries with plaque-like degeneration were observed not infrequently in the brain stem. The distribution of plaques did not always coincide with that of neurofibrillary tangles.

Aged↗

PubMed1989

"Grumose degeneration" of Trétiakoff.

We reviewed Trétiakoff's "grumose degeneration (GD)" which described pathologic cellular change in the substantia nigra (SN). This term has been occasionally used up to the mid-1960s by Greenfield et al.; it has rarely been used after the 1970s. This study emphasises the following: (1) after the 1970s, GD has sometimes been signalled in the SN under various names, such as "spheroid with foamy appearance", "granular spheroid", "saccular structure", or "foamy spheroid body"; (2) the ultrastructure of GD is unknown, being entirely different from that of typical axonal swellings (so-called "spheroids"); (3) more attention should be paid to GD in the SN because its nature has remained unclarified since the original description; and (4) "GD" in the cerebellar dentate nucleus is essentially different from Trétiakoff's GD.

Cerebellar Nuclei↗

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

[Studies on oral sensation in patients with implant denture. 3. Ability of interdental dimension discrimination].

Interdental dimension discrimination (IDD) ability in 11 patients with implant dentures was compared with that in 10 normal dentate subjects and bridge wearers. Using a 3.0 mm diameter wire as a reference, minimum perception difference between reference wire and test wires were measured at first molar region. In discrimination of thicker wires from reference wire, IDD ability was highest in normal dentate subjects followed by bridge wearers. It was lowest in implant denture wearers. In discrimination of thinner wires from reference wire. IDD ability was highest in bridge wearers followed by normal dentate subjects. It was lowest in implant denture wearers. A so-called "directional specificity", namely, higher IDD ability between thinner wires and reference wire than between thicker wires and reference wire, was recognized in normal dentate subjects and bridge wearers. However, there was no demonstrable directional specificity in implant denture wearers. On analyzing IDD ability in individual patients of implant denture wearers. IDD of both thicker and thinner wires from reference wire were approximately the same in 3 of the patients as those in normal dentate subjects and bridge wearers. In 7 patients, IDD ability of either thicker or thinner wires from reference wire was lower compared to the two other groups. In remaining patient, IDD of both thicker and thinners wire was impaired.

Dental Implants↗

PubMed1989

[Changes in chewing rhythm during repetitive series of mastication in normal adults as a function of time elapsed and the four basic taste stimuli].

Surface EMG activities in the masseter muscle were recorded from 8 healthy men with normal permanent dentition during habitual chewing of a small cube of synthetic cellulose sponge which had absorbed distilled water. Three parameters of chewing rhythm, viz., cycle time, duration, and interval, were shown as the respective averages of 40 measurements of the EMG traces of a masticatory series of 42 consecutive chewing strokes. Twenty-five recording sessions, in each of which the above masticatory series were repeated 10 times in a day with a 5 minutes' recess between each series, were performed on a subject during continuous 25 days. The amount of scatter in the distribution of 25 cycle time values was great at the 1st masticatory series, gradually decreased to reach a node relatively free from the dispersion at the 5th series, and then gradually increased from the 6th to 10th series. The same phenomenon was observed in all 8 subjects, although there was a small difference among them in the number of the series where the node was apparent. The average of 5 cycle time values was used to compare in the same subject the effect of chewing the cellulose sponge which had absorbed one of the 4 basic taste solutions with the effect of chewing that which had absorbed distilled water. The average value while chewing the sponge which had absorbed 1 M saccharose was significantly lower in the subjects who obtained a relatively large average value during distilled water sponge-chewing, whereas it was significantly greater in those who obtained a relatively small average value while chewing the sponge which had absorbed distilled water. The other 3 taste stimuli induced a significant increase in the average value in most subjects.

Adult↗

PubMed1989

[A study on the formation of apatite crystallized with gel method].

About apatite produced with a silicahydro gel method using calcium nitrate (group I) or calcium chloride (group II) and a gelatin gel method by use of calcium nitrate (group III) or calcium chloride (group IV), the formative volume as well as the formative condition of a periodic-layered precipitate (Liesegang ring), the pH measurement, calculation of Ca/P ratio, an estimation of the chlorine ion, morphological observation with a scanning electron microscope, qualitative analyses by X-ray diffraction (identification, crystallite size, lattice imperfections, lattice constants) and the composition analysis by infrared absorption spectroscopy were carried out to elucidate the formation of apatite using the gel method. The result showed that there were no distinct differences between group I-II and group III-IV, and it is suggested that it is possible to form satisfact fluorapatite with a gel method using calcium chloride as well as calcium nitrate.

Apatites↗

PubMed1989

[Study on frictional characteristics of KB horizontal brackets. A comparative study of kinetic frictional forces to be caused between various kinds of brackets and wires].

KB horizontal brackets were designed to tip no more than 6 degrees at the maximum. This tipping amount is based on the idea of reducing friction between a wire and brackets to allow the effective tooth movement of the Begg technique even with horizontally long brackets, and does not originate in the concept of carrying out tipping movement. Thereon, experimental measurements by use of Rheometer were conducted to review for comparison of the kinetic frictional forces caused between various wires and the following four types of brackets; KB horizontal brackets, Tip edge brackets, Straight edge brackets and Begg brackets. 1. In case of utilizing ribbon arch wires and rectangular wires, no significant difference was acknowledged among Tip edge, KB horizontal and Straight edge brackets. 2. There proved to be a reduction in the kinetic frictional forces by incorporating tip into the edgewise slots, when using smaller dimensions of the wires which call for the effective tooth movement, however, Begg brackets (in conjunction with Ordinary T-pins and/or Safety T-pins) showed the small value which is far less than that of the three kinds of brackets.

Orthodontic Appliances↗

PubMed1989

[Enhancement of enamel crystallinity with gel method during orthodontic treatment. The 2nd report: application of micro-area X-ray diffraction method].

This study is to review an effect on the improvement of enamel crystallinity with gel method in the course of orthodontic treatment by applying gelatin gel method (group II) as well as silica-hydro gel method (group I) to bracket-bonded enamel surfaces of extracted teeth and for a relative review, the chopped cross sections of the above teeth were analyzed by the method of micro area X-ray diffraction. The results obtained were as follows: 1. As a result of identifying by the method of microarea X-ray diffraction, the present of hydroxyapatite, Ca5(PO4)3OH and fluorapatite, Ca5(PO4)3F was recognized at any section of every group. 2. In making a relative study of the variation of line profile and peak shift, an outstanding difference was not acknowledged in line profile, however, peak shift in the direction of high angle side was indicated on the experimental side of each group and a tendency for peak shift was more noticeable near by enamel cuticle. At boundary sites and on the control side, the variation was only shown in one part of group II. Also a tendency for peak shift in the direction of high angle side was recognized in group I rather than in group II. From the foregoing results, it was found to be effective to improve tooth substance of the bracket-bonded enamel and in that event, the silica-hydro gel method was suggested to be superior to the gelatin gel method. Also with the regard to the bracket-bonded sides, tooth substance was noticeably improved at enamel cuticle but not sufficiently improved at sites underneath the brackets and at boundary sites of the both, therefore, one of the future subjects would be to review such areas.

Apatites↗

PubMed1989

The effect of pentobarbital and ether anesthesia on rat brain PGD2 content.

Effects of pentobarbital and ether anesthesia on PGD2 contents in brain and plasma levels of compound beta, A.C.TH. epinephrine (E) norepinephrine (NE) and dopamine were investigated in 39 male Wistar strain rats weighing 280-300 g. They were divided into 3 groups: pentobarbital anesthesia group (P.A.), ether anesthesia group (E.A.) and control. Anesthesia or not the rats were decapitated the heads were frozen with liquid nitrogen and PGD2 were extracted and assayed by radioimmunoassay. In the group of P.A. and E.A., PGD2 contents of the brain were decreased by 69.6% and 77.8% of the control group respectively. In the group PA, plasma levels of Comp-beta, ACTH, E and NE were significantly decreased. In the EA group, plasma levels of Comp-beta was not changed but that of ACTH, E and NE were significantly increased. In the EA and PA groups, plasma levels of dopamine were not significantly changed. Intraventricularly injected PGD2 has been reported to induce the natural sleep in rat, increase or decrease the pain threshold and lower the body temperature in rat. On the other hand, intravenous injection of PGD2 has been reported to prolong the duration of pentobarbital anesthesia in rat or changed the EEG pattern to slow wave in cat. Stresses including restrain and foot shock have been reported to increase the PGE2 and PGF2a in the brain of rat. The present findings demonstrate that pentobarbital and ether anesthesia decreased the PGD2 contents in the brain of rat.

Anesthesia, General↗

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↗