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Biomedical subjects

H Wada

Publications and source records attributed to H Wada.

At least 991 records · Page 55Linked to original sources

Cell sparse zones in the ventrolateral thalamic mass in humans, monkeys and cats: their special reference to kinesthetic neurons.

The Vim nucleus of the human thalamus is the cell sparse zone. The neurons in this zone respond to peripheral stimuli of kinesthetic modality with a short latency. In the cytometrical study, the cell sparse zone is identifiable in both the monkey and cat thalamus. The cell dimension and density in a 1 mm2 area in the cell sparse zone of each species are as follows: humans--large neuron 500-900 microns2, medium neuron 200-400 microns2, cell density 60-90/mm2/50 microns thickness; monkeys--large neuron 400-800 microns2, medium neuron 200-400 microns2, cell density 120-250/mm2/50 microns thickness; cats--large neuron 400-800 microns2, medium neuron 200-400 microns2, cell density 120-250/mm2/50 microns thickness. In this zone, there are large and medium thalamocortical relay neurons defined by the Golgi impregnated and HRP studies. It is still obscure which neurons respond to kinesthetic stimulation and which neurons or afferent fibers play important roles in the tremor mechanism.

Animals↗

Immune responses to polyethylene glycol modified L-asparaginase in mice.

Suppression of anti-L-asparaginase (anti-A-ase) IgG and IgE antibody responses was achieved in Balb/c mice with polyethylene glycol (PEG, MW, 5,000) conjugated Escherichia coli A-ase. Following the administration of the mixture of A-ase and PEG-A-ase, antibody production to A-ase was reduced. PEG-A-ase administration prior to A-ase suppressed the primary and secondary responses to A-ase antibody. The suppression could be transferred to normal mice with spleen cells from A-ase tolerant mice. The cell transfer experiment showed that the suppression was caused by suppressor T cells. Since PEG-A-ase administration failed to suppress antibody response to ovalbumin, the suppression seemed to be A-ase specific. PEG-A-ase administration also suppressed the delayed type hypersensitivity reaction. IgG and IgE antibodies to PEG or PEG-A-ase were not detected in mice immunized with PEG or PEG-A-ase in the presence of Freund's complete adjuvant or A1(OH)3, respectively.

Animals↗

Persistent primitive trigeminal artery, cavum septi pellucidi, and associated cerebral aneurysm in a patient with polycystic kidney disease: case report.

A 51-year-old man with polycystic kidney disease had a persistent primitive trigeminal artery, cavum septi pellucidi, and an unruptured cerebral aneurysm. He had a history of long-standing hypertension, but not of subarachnoid hemorrhage. Computed tomograms revealed cavum septi pellucidi. Because of the polycystic kidney disease, we performed four-vessel cerebral angiography, which revealed a persistent primitive trigeminal artery and a cerebral aneurysm at the bifurcation of the left internal carotid artery. The neck of the aneurysm was clipped successfully without producing any neurological deficit. The clinical significance of the combination of these multiple anomalies and cerebral aneurysms is discussed.

Arteries↗

Effects of alpha-fluoromethylhistidine on increase in histidine decarboxylase activity of maternal mouse kidney observed during late pregnancy and evidence for its non-mast cell origin by using estrogen and W/WV mice.

The increase of histidine decarboxylase (HDC) activity during late pregnancy in the whole bodies of fetal mice and the kidneys of their mothers were almost completely inhibited by i.p. administration of 25 mg/kg of alpha-fluoromethylhistidine (alpha-FMH), a suicide inhibitor of HDC, starting on day 13 of pregnancy. The increase of HDC in fetal mice was previously shown to be in mast cells [T. Watanabe et al., Proc. Natl. Acad. Sci. U.S.A. 78, 4209-4212 (1981)]. The increase of HDC in maternal kidneys was examined by using estrogen and W/WV mice, which were devoid of mast cells and infertile. Treatment of castrated mice with 17-beta-estradiol increased the HDC activity of the kidney, and this increase was antagonized by concomitant treatment with clomiphene, an antiestrogen, confirming that the increase is mediated through an estrogen receptor. HDC activity in the kidney of W/WV mice was also increased by estradiol treatment, indicating that HDC activity was associated with non-mast cells.

Animals↗

A silica-based reversed-phase column for single-stranded oligodeoxyribonucleotides.

A novel, silica-based, reversed-phase column targeted to the separation of single-stranded oligodeoxyribonucleotides has been developed by grafting monochlorooctadecylsilane onto silica which is a base material of reversed-phase columns (TSK 120A and 120T), in which polychlorosilane is used as a grafting reagent. By applying a shallow gradient elution of an aqueous acetonitrile solution containing 0.1 M ammonium acetate, chromatography with this column produced well-resolved peaks for large samples such as those having bases up to 26.

Chromatography, High Pressure Liquid↗

Malignant melanoma of the spinal epidural space metastasized from the enucleated left eye after nine years without symptoms: report of a case.

A case of flaccid paraplegia due to a metastatic spinal epidural melanoma is reported. Symptoms occurred approximately 9 years after the enucleation of the left eye. A solid melanotic mass was removed almost totally. Three years after the operation, the patient had not regained the motility of the lower limbs. The need for long term follow-up and management of patients with such problems is discussed, and the pertinent literature is reviewed.

Choroid↗

[Long-term follow-up study of selective VIM-thalamotomy].

To evaluate the effect of the physiologically defined selective Vim-thalamotomy on tremor type Parkinson's disease (PA, 26 cases) and essential tremor (ESS-T, 16 cases), a long-term follow-up study was conducted. The follow-up time extended from 4 months to 7 years (mean: 3.6 years). On 42 cases a total of 49 operations (4 bilateral surgery and 3 reoperations) were carried out. After identifying kinesthetic neuron, the coagulative lesion was made by using Leksell's apparatus between two needles of 4 mm effective tip length located with 3 mm interval including the recording point. One coagulation (unit lesion) destroyed about 20 mm3 brain tissue taking account of the mechanical damage by the needles themselves. The unit lesion was added around an imaginary cylinder of 3 mm radius, until the tremor was abolished completely. On the basis of number of unit lesion and its extent within an imaginary cylinder, these 49 operations were divided into the following group. Group I (minimal lesion group): coagulative lesion of 1 to 3 units within a quadrant of the imaginary cylinder. Group II: 3 to 5 units within 1/2 to one cylinder. The early (14 days after operation) and the late results on the tremor were evaluated clinically and electromyographically by 4 different categories: complete abolition, slight residual, residual, and recurrence in a strict sense. The late results in 13 PA cases of group I (similar to the early results) were: 10 complete abolition, 2 slight residual and one recurred, this case was reoperated 3 months after first operation and therefore categolized in group II. The late results in 11 ESS-T cases of group I were: 6 complete arrest, 4 slight residual, and one recurred case, which had been reoperated 2 years after operation. Therefore in a total of 24 minimal lesioned cases with PA and ESS-T complete abolition in 16, slight residual in 6, and 2 reoperated cases. In these successful 22 cases with minimal lesion, the tremor was abolished without noticeable long-lasting side effect. In other 20 cases with PA and ESS-T of group II, the tremor was almost completely relieved and maintained. In conclusion, by radiographically and physiologically controlled selective Vim thalamotomy for Parkinsonian and essential tremor, it was shown that the effect of minimal lesion was valid and well maintained on the long-term follow-up base.

Adult↗

Origins of histamine-containing fibers in the cerebral cortex of rats studied by immunohistochemistry with histidine decarboxylase as a marker and transection.

The origins of histamine-containing fibers in the cerebral cortex were examined by means of the retrograde tracer technique of horseradish peroxidase (HRP)-immunohistochemistry with histidine decarboxylase (HDC) as a marker for the histamine neuron system. Total transection of the brain rostral to the posterior hypothalamus resulted in disappearance of HDC-like immunoreactive (HDCI) fibers in the cerebral cortex, but total transection caudal to the posterior hypothalamus did not decrease the number of HDCI fibers in the cortex, suggesting that HDCI fibers in the cerebral cortex originate in the posterior hypothalamus. The projection of HDCI neurons from the posterior hypothalamus to the cerebral cortex seemed to be bilateral because hemi-transection of the brain rostral to the posterior hypothalamus resulted in a bilateral decrease of HDCI fibers in the cerebral cortex with ipsilateral predominance. After injection of HRP into the cerebral cortex, numerous cells containing both HRP granules and HDCI structures were found bilaterally in the tuberal, caudal and postmamillary magnocellular nuclei, with ipsilateral predominance. These findings indicate that HDCI cells in the above nuclei give rise to axons extending bilaterally to the cerebral cortex.

Animals↗

Effect of a new eburnamine derivative, RU 24722, on the turnover of monoamines in mouse brain: selective and reversible decrease of noradrenaline.

A new eburnamine derivative, RU 24722, is structurally similar to vincamine and is known to cause a specific and reversible decrease of noradrenaline in rat brain. The effects of RU 24722 on the turnover of monoamines in mouse brain were investigated. The noradrenaline level in mouse brain was significantly decreased after administration of RU 24722 10 mg/kg i.p. with significant increases in 3-methoxy-4-hydroxyphenylglycol, 3,4-dihydroxyphenylacetic acid and homovanillic acid. The levels of these compounds returned to the control levels within 5 h. The levels of dopamine, serotonin, 5-hydroxyindoleacetic acid and histamine were not affected by this dose of RU 24722. Higher doses of RU 24722 (25 and 50 mg/kg) decreased the concentration of serotonin significantly with a significant increase in 5-hydroxyindoleacetic acid. There were no differences between the patterns of change in the forebrain, midbrain and hindbrain. These results indicate that RU 24722 increased the turnover of noradrenaline and dopamine in mouse brain at the dose of 10 mg/kg and the turnover of serotonin was also increased only at higher doses.

3,4-Dihydroxyphenylacetic Acid↗

Fine structure of histaminergic neurons in the caudal magnocellular nucleus of the rat as demonstrated by immunocytochemistry using histidine decarboxylase as a marker.

The morphology of histamine-containing neurons in the caudal magnocellular nucleus was light and electron microscopically examined by means of peroxidase-antiperoxidase (PAP) immunocytochemistry with histidine decarboxylase (HDC) as a marker. HDC-like immunoreactive (HDCI) neurons had large (25-30 microns in diameter) perikarya from which two to four primary dendrites arose. The perikarya had a nearly round nucleus and well-developed Golgi apparatus in addition to a large number of mitochondria and rough endoplasmic reticulum. Immunoreactive endproducts were found diffusely throughout the perikarya, dendrites, and axons. HDCI neurons made synaptic contact with nonreactive axon terminals on the perikarya and dendrites. In addition, the HDCI neurons very frequently formed puncta adherentia with neuronal elements, either HDCI or nonreactive, or glial cells. Most of the HDCI axon terminals serially observed under electron microscopy did not exhibit typical synaptic contact in the caudal magnocellular nucleus. These findings suggest the nonsynaptic release of histamine in the caudal magnocellular nucleus.

Animals↗

Abnormalities in plasma catecholamine response and tissue catecholamine accumulation in streptozotocin diabetic rats: a possible role for diabetic autonomic neuropathy.

Plasma catecholamine levels, determined by high performance liquid chromatography, were elevated in response to blood withdrawal in normal rats. Such a response was also observed in streptozotocin diabetic rats 2 and 6 weeks after disease onset, but was no longer seen at 13 weeks. Tissue (adrenal, heart, skin, kidney) catecholamine levels in diabetic rats were increased at 6 weeks as well as at 13 weeks. These abnormalities were corrected by insulin treatment in at least a part of diabetic rats. The present data suggest that there might be a catecholamine accumulation, which is later accompanied with an impairment of catecholamine secretion, in diabetic rats, and they gave a basis for an inference that similar changes might play some role in the pathogenesis of diabetic autonomic neuropathy in man.

Adrenal Glands↗

Purification of histidine decarboxylase from the liver of fetal rats and its immunochemical and immunohistochemical characterization.

Histidine decarboxylase was purified from fetal rat liver about 3,000-fold by the method described previously (Watanabe, T., Nakamura, H., Leu, Y.L., Yamatodani, A., and Wada, H. (1979) Biochem. Pharmacol. 28, 1149-1155) except that DEAE-cellulose column chromatography, Sephacryl S-300 gel filtration, and preparative polyacrylamide gel electrophoresis were added. The enzyme had a molecular weight of 110,000 in the native state and gave a single band of protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis in a position corresponding to a molecular weight of 54,000, indicating that it was a dimer. Its isoelectric point was pH 5.1. Antibody raised in rabbits against the enzyme gave single fused precipitation lines with the enzymes from fetal rat liver and adult rat brain and stomach in Ouchterlony's double diffusion test, and inhibited these three enzymes similarly and strongly. Using this antibody, histidine decarboxylase-like immunoreactive structures were located in fetal liver and peritoneal mast cells, stomach and brain of rats.

Animals↗