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S Mitake

Publications and source records attributed to S Mitake.

At least 19 recordsLinked to original sources
PubMed2001

Age-dependent changes in HCNP-related antigen expression in the human hippocampus.

Hippocampal cholinergic neurostimulating peptide (HCNP), originally purified from the young rat hippocampus, enhances the cholinergic phenotype development of the medial septal nucleus in vitro. In this study, we examined the HCNP-antigen distribution and the age-related changes in the number of positive cells in the hippocampus (obtained at autopsy from 74 subjects with no known neurological disorders). Immunohistochemical assay revealed that the immunopositive cells were GABAergic neurons and oligodendrocytes. They were first identified in the fetus at around 25 to 30 weeks and their number increased rapidly with advancing postconceptional age to reach maximal at the perinatal stage and in early postnatal life; it then decreased to the adult level by 10 years old. These results suggest that HCNP-related antigen may play important roles in the development and/or differentiation of the human hippocampus.

Adolescent↗
PubMed2001

Decrease of neurons in the medullary arcuate nucleus in myotonic dystrophy.

Respiratory insufficiency has been reported frequently in patients with myotonic dystrophy (MyD). Recent data support the hypothesis that this respiratory failure results from a primary dysfunction of the central nervous system. The medullary arcuate nucleus (ARC) has been shown to be involved in the regulation of respiration. We performed a quantitative study of neurons in the ARC in eight MyD patients, ten control subjects with other neurological diseases (control group A) and eight control subjects without neurological diseases (control group B). Alveolar hypoventilation of the central type occurred in three of the MyD patients but not in the remaining MyD patients or controls. The density of neurons in the ARC in MyD patients with hypoventilation was significantly lower than in MyD patients without hypoventilation and control groups A and B. There was no significant difference in the neuronal density of the ARC between MyD patients without hypoventilation and control groups A and B. These data suggest that the neuronal loss of the ARC is associated with the presence of hypoventilation in MyD.

Aged↗
PubMed2000

Interferometric modulation of an atomic beam by an electric field: A phase hologram for atoms

Electric-field-controlled atomic holography has been demonstrated. A binary hologram pattern was encoded in the gaps of regularly spaced parallel stripes of platinum electrodes formed on SiN4 thin film. Each electrode was either grounded or connected to a terminal. The electrode connections were arranged so that an electric field appeared in approximately half the 512 gaps when a finite voltage was applied to the terminal. By controlling this voltage, we could shift, erase, or switch holographically reconstructed two-dimensional images of atoms on a screen.

Journal Article↗
PubMed2000

Hippocampal cholinergic neurostimulating peptides (HCNP).

Neuronal development and differentiation require a variety of cell interactions. Diffusible molecules from target neurons play an important part in mediating such interactions. Our early studies used explant culture technique to examine the factors that enhance the differentiation of septo-hippocampal cholinergic neurons, and they revealed that several components resident in the hippocampus are involved in the differentiation of presynaptic cholinergic neurons in the medial septal nucleus. One of these components, originally purified from young rat hippocampus, is a novel undecapeptide (hippocampal cholinergic neurostimulating peptide; HCNP); this enhances the production of ChAT, but not of AchE. Later experiments revealed that: (1) a specific receptor appears to mediate this effect; (2) NGF and HCNP act cooperatively to regulate cholinergic phenotype development in the medial septal nucleus in culture; and (3) these two molecules differ both in their mechanism of release from the hippocampus and their mechanism of action on cholinergic neurons. The amino acid sequence deduced from base sequence analysis of cloned HCNP-precursor protein cDNA shows that HCNP is located at the N-terminal domain of its precursor protein. The 21 kDa HCNP precursor protein shows homology with other proteins, and it functions not only as an HCNP precursor, but also as a binding protein for ATP, opioids and phosphatidylethanolamine. The distribution and localization of HCNP-related components and the expression of their mRNAs support the notion that the precursor protein is multifunctional. In keeping with its multiple functions, the multiple enhancers and promoters found in the genomic DNA for HCNP precursor protein may be involved in the regulation of its gene in a variety of cells and at different stages of development. Furthermore, several lines of evidence obtained from studies of humans and animal models suggest that certain types of memory and learning disorders are associated with abnormal accumulation and expression of HCNP analogue peptide and/or its precursor protein mRNA in the hippocampus.

Amino Acid Sequence↗
PubMed2000

Neuronal distribution and subcellular localization of HCNP-like immunoreactivity in rat small intestine.

A novel peptide, hippocampal cholinergic neurostimulating peptide (HCNP), originally purified from young rat hippocampus, affects the development of specific cholinergic neurons of the central nervous system in vitro. In this study, HCNP-like-immunoreactive nerve processes and nerve cell bodies were identified by electron microscopic immunocytochemistry in the rat small intestine. Labeled nerve processes were numerous in the circular muscle layer and around the submucosal blood vessels. In the submucosal and myenteric plexuses, some HCNP-like-immunopositive nerve cell bodies and nerve fibers were present. The reaction product was deposited on the membranes of various subcellular organelles, including the rough endoplasmic reticulum, Golgi saccules, ovoid electron-lucent synaptic vesicles in axon terminals associated with submucosal and myenteric plexuses, and the outer membranes of a few mitochondria. The synaptic vesicles of HCNP-like positive terminals were 60-85 nm in diameter. The present data provide immunocytochemical evidence that HCNP-like-positive nerve cell bodies and nerve fibers are present in the submucosal and myenteric plexuses of the rat small intestine. An immunohistochemical light microscopic study using mirror-image sections revealed that in both the submucosal and myenteric ganglia, almost all choline acetyltransferase (ChAT)-immunoreactive neurons were also immunoreactive for HCNP. These observations suggest (i) that HCNP proper and/or HCNP precursor protein is a membrane-associated protein with a widespread subcellular distribution, (ii) that HCNP precursor protein may be biosynthesized within neurons localized in the rat enteric nervous system, and (iii) that HCNP proper and/or HCNP precursor protein are probably stored in axon terminals.

Animals↗
PubMed2000

[An autopsy case of corticobasal degeneration without prominent cortical pathology--an imitator of progressive supranuclear palsy].

We describe an autopsy case of parkinsonism with bradykinesia, muscle rigidity, and dementia as major symptoms. The patient had developed bradykinesia at the age of 62, and then muscle rigidity, a parkinsonian posture, bradylalia, and dementia gradually appeared. Neurological examination revealed rigidity in the neck and limbs, with motion and speech being generally slow. He lacked involuntary movements including alien hand, tremor, chorea, and dystonia. Vertical gaze palsy, both upward and downward was noted, but other cranial nerves were intact. He was diagnosed as suffering from PSP clinically based on vertical gaze palsy, bradykinesia, instability on standing and gait, and dementia. Levodopa was only transiently effective. Within three years he became bed-ridden and in a state of akinetic mutism. At age 65 he died from pneumonia. Neuropathology revealed severe neuronal degeneration and gliosis in the substantia nigra. Because atrophy of the tegmentum of brainstem, dentate nuclei, inferior olivary nuclei was very mild and Alzheimer neurofibrillary tangles in the brainstem were relatively few, PSP was ruled out. Cortical neuronal degeneration was not apparent, but in the deep layer of cingulate gyrus, frontal lobe, and insula, there were several ballooned neurons. Gallyas-Braak silver staining showed no tuft-shaped astrocytes, specific for PSP, but it disclosed astrocytic plaques in the basal ganglia and the cerebral cortex. At present, astrocytic plaques are recognized as a hallmark of corticobasal degeneration (CBD), along with ballooned neurons in the cerebral cortex. The present case thus illustrates that CBD has a wide spectrum and may include cases in which degeneration of cerebral cortex is very mild.

Aged↗
PubMed1999

Presence of up-stream and downstream components of a mitogen-activated protein kinase pathway in the PSD of the rat forebrain.

We previously reported the presence of Erk2 type mitogen-activated protein kinase (MAPK) and enrichment of its substrates in the post-synaptic density (PSD) fraction, and suggested a role for MAPK in the synaptic transmission and its modulation [Suzuki, T., Okumura-Noji, K., Nishida, E., ERK2-type mitogen-activated protein kinase (MAPK) and its substrates in post-synaptic density fractions from the rat brain, Neurosci. Res., 22 (1995) 277-285.]. In this paper, synaptic localization of the upstream and downstream components of a MAPK cascade was examined. We found that RSK1, Sos1, N-Shc 66 kDa, N-Shc 52 kDa, and Grb2 were present in the PSD fraction, and cPLA(2) was present in the synaptic plasma membrane fraction. RSK2, Sos2, and N-Shc 46 kDa were not present in the PSD fraction. Post-synaptic localization of RSK1 and Sos1 was confirmed by immunohistochemical examination at the electron microscopic level: the two immunoreactivities were localized in the PSDs, both in the spines and dendrites. These results suggest that all the MAPK cascade components examined were associated with PSD or the synaptic plasma membrane, suggesting the role(s) of the MAPK cascade for synaptic transmission and its regulation at post-synaptic sites.

Animals↗
PubMed1999

[A case of Miller Fisher syndrome with gadolinium-enhancing lesions in the cranial nerves and the cauda equina on magnetic resonance imaging].

MRI findings for a patient with Miller Fisher syndrome (MFS) are reported. A 25-year-old woman presented with blephaloptosis, double vision, and gait disturbance after antecedent upper respiratory infection. Neurologic examination on admission revealed bilateral blephaloptosis and restriction of extraocular movement. She was unable to maintain an upright posture, nor able to walk because of severe truncal ataxia. Mild limb ataxia was also seen. The tendon reflexes were generally absent and she had hypesthesia in her shoulder and upper limbs. On the next day, her eyes became fixed in the central position. Based on these characteristic symptoms, she was diagnosed as having MFS and underwent plasmapheresis therapy six times. Although ataxia gradually reduced, ophthalmoplegia did not improve and severe symmetric facial nerve palsy appeared. Antiganglioside IgG antibodies (anti-GQ1b and GD1b) were detected in the sera on admission. Spinal fluid examination on day 18 revealed 5 cells/microliter and protein 171 mg/dl. T1-weighted images with Gd-DTPA on day 15 demonstrated enhancement of the posterior nerve roots of the cauda equina. MRI on day 32 revealed swelling and enhancement of the bilateral oculomotor nerves, as well as the facial nerves and the abducens nerves. Marked improvement of ophthalmoplegia followed high dose intravenous immunoglobulin therapy. Gd-enhanced MRI after recovery showed no enhancement of the cauda equina, nor the cranial nerves. These findings well correlated with her clinical features. Although abnormal Gd-enhancement of the cranial nerves or cauda equina in several neurological disorders has been documented, similar findings have been rarely reported in MFS. In our patient, IgG anti-GQ1b and GD1b antibodies were detected and the distribution of Gd-enhanced lesions was compatible with the distribution of the involved gangliosides. We suggest that contrast enhanced MRI is useful for identifying affected cranial nerves and cauda equina nerve roots. In addition, MRI may play a significant role in disclosing the pathophysiology of this disease.

Adult↗
PubMed1998

Occurrence of a transcription factor, cAMP response element-binding protein (CREB), in the postsynaptic sites of the brain.

The postsynaptic density (PSD) fraction prepared from the rat forebrain contained a transcription factor, cAMP response element-binding protein (CREB). The occurrence of CREB in the PSD was confirmed by immunoelectron microscopic examination. CREB in the PSD fraction was phosphorylated both by protein kinase A and Ca2+/calmodulin-dependent protein kinase II (CaMKII) endogenous to the fraction, and dissociated from the PSD after phosphorylation, especially under CaMKII-activated conditions. The fraction containing CREB that was released from PSD after phosphorylation possessed cAMP response element (CRE)-binding activity. Thus, PSD anchors functionally active CREB. These results suggest that CREB anchored to the PSD is liberated by phosphorylation upon specific synaptic stimulation, translocates into the nucleus, and then triggers synaptic activity-dependent changes in gene expression.

Animals↗
PubMed1998

NMDA receptor activation enhances the release of a cholinergic differentiation peptide (HCNP) from hippocampal neurons in vitro.

Hippocampal cholinergic neurostimulating peptide (HCNP) is a novel undecapeptide purified from the hippocampus of young rats. The peptide stimulates cholinergic phenotype development in the rat medial septal nucleus in vitro. Here, we have focused on the mechanism of release of the peptide from the hippocampus, by applying tissue culture techniques. Quantitation of HCNP in the culture supernatant after chemical stimulation was carried out by RIA, and by a combination of HPLC and RIA. We found that the N-methyl-D-aspartate (NMDA) receptor specifically mediates release of the deacetylated form of HCNP from the culture. Our results suggest that during the early development of hippocampal neurons, the peptide is released by NMDA receptor activation, and that it may be involved in mediating the effect of activity-dependent cues on developing septal cholinergic neurons.

Animals↗
PubMed1998

High levels of hippocampal cholinergic neurostimulating peptide (HCNP) in the CSF of some patients with Alzheimer's disease.

Hippocampal cholinergic neurostimulating peptide (HCNP), originally purified from the hippocampus of young rats, enhances the cholinergic development of rat medial septal nuclei in vitro. This report concerns the determination of the HCNP content of the cerebrospinal fluid (CSF) of 173 clinically, and of 22 clinico-pathologically defined patients. A radioimmunoassay was used throughout. The HCNP level was relatively uniform among the clinically defined patients; for almost all non-Alzheimer's patients, the level fell within the range delimited by +/- 2 SD of the mean for all patients taken together, and none of them had a level above this range. By contrast, the early-onset Alzheimer's disease patients could be divided on the basis of their HCNP level into two groups, one with high levels (markedly above the mean +/- 2SD range), and the other with levels similar to those of the other patients. The analysis of the CSF samples obtained postmortem revealed that Group I Alzheimer-type dementia (ATD) patients with clinico-pathologically established diagnoses had a strikingly higher level of HCNP than patients with either Group II ATD or cerebral vascular disease. These results suggest that HCNP is involved in certain pathophysiological alterations associated with dementia, and that its determination may be useful in patient evaluation. Copyright 1998 Lippincott Williams & Wilkins

Journal Article↗
PubMed1998

An unusual course of progressive multifocal leukoencephalopathy in a patient with idiopathic CD4+ T lymphocytopenia.

A case is reported of idiopathic CD4+T lymphocytopenia with progressive multifocal leukoencephalopathy and cervical lymph node tuberculosis. A 57 year old Japanese man presented with cervical lymphadenopathy and progressive neurological deficits, and six months later he developed akinetic mutism. He had a persistent severely depressed number of circulating CD4+T lymphocytes in the absence of human immunodeficiency virus infection. T1 weighted MRI showed a diffuse decreased signal intensity limited to the white matter without mass effect. A brain biopsy specimen had a morphology similar to that of progressive multifocal leukoencephalopathy. Polyomavirus antigen was detected in the brain lesion, and viral DNA was identified in nucleated blood cells and urine. Unusually this serious medical condition has lasted for more than three years without remission. To our knowledge this is the first patient with CD4+T lymphocytopenia with progressive multifocal leukoencephalopathy, suggesting that similar opportunistic infections should be considered even in previously normal people.

Antigens, Viral↗
PubMed1998

Loss of serotonin-containing neurons in the raphe of patients with myotonic dystrophy: a quantitative immunohistochemical study and relation to hypersomnia.

Hypersomnia occurs frequently in patients with myotonic dystrophy (MyD). We performed a quantitative immunohistochemical study of serotonin (5-HT)-containing neurons linked to hypersomnia in the dorsal raphe nucleus (DRN) and the superior central nucleus (SCN) in 8 patients with MyD, 5 of whom showed hypersomnia, and in 12 age-matched controls. The densities of 5-HT neurons in the DRN and the SCN were significantly lower in MyD patients with hypersomnia than in MyD patients without hypersomnia and controls. These data suggest that the loss of 5-HT neurons of the DRN and the SCN is associated with the presence of hypersomnia in MyD.

Aged↗
PubMed1998

Loss of catecholaminergic neurons in the medullary reticular formation in myotonic dystrophy.

OBJECTIVE: To clarify the possible relation between the extent of involvement of catecholaminergic neurons and the presence of alveolar hypoventilation in patients with myotonic dystrophy (MyD). BACKGROUND: Respiratory insufficiency has been reported frequently in MyD patients. Recent data support the hypothesis that this respiratory failure results from a primary dysfunction of the CNS. METHODS: The authors performed a quantitative immunoreactive study of tyrosine hydroxylase immunoreactive (TH+) neurons linked to hypoventilation in the dorsal central medullary nucleus (DCMN), the ventral central medullary nucleus (VCMN), and the subtrigeminal medullary nucleus (SMN)--where the autonomic respiratory center is thought to be located--in eight MyD patients and in 10 age-matched control subjects. Alveolar hypoventilation of the central type was present in three of the MyD patients but not in the remaining MyD patients or the control subjects. RESULTS: The densities of TH+ neurons of the DCMN, the VCMN, and the SMN in MyD patients with hypoventilation were significantly lower than in those without hypoventilation (p < 0.02, p < 0.01, and p < 0.01, respectively) and control subjects (p < 0.01, p < 0.01, and p < 0.01, respectively). CONCLUSIONS: These data suggest that the loss of TH+ neurons of the DCMN, the VCMN, and the SMN is associated with the presence of hypoventilation in MyD and may be an important feature of MyD.

Aged↗
PubMed1997

Presence of NF-kappaB-like and IkappaB-like immunoreactivities in postsynaptic densities.

The distributions of IkappaB and NF-kappa B immunoreactivities were examined immunohistochemically in the rat brain by the electron microscopy. Antibodies were raised against synthetic peptides with the sequences specific to the human MAD-3 type IkappaB or NF-kappa B. Both IkappaB alpha and NF-kappa B immunoreactivities were localized in the dendrites including the spines and, particularly, the postsynaptic densities (PSDs) of the hippocampus and the cerebral cortex. The PSD fraction prepared from the rat brain contained an activity that inhibited the binding of NF-kappa B to the kappa B DNA elements. These results suggest that the NF-kappa B/IkappaB system or a similar mechanism may play a role in signal transmission from synapses to the nucleus.

Amino Acid Sequence↗
PubMed1997

Excitable membranes and synaptic transmission: postsynaptic mechanisms. Localization of alpha-internexin in the postsynaptic density of the rat brain.

The synaptic localization of alpha-internexin, a brain-specific intermediate filament protein, was investigated immunohistochemically in the rat brain. The specificity of the antibody used in this study was confirmed by Western blotting and the antibody specifically reacted with alpha-internexin in the neurofilament preparation and in the postsynaptic density (PSD) fraction. The alpha-internexin immunoreactivity was distributed in neurons, especially in the somata and dendrites, throughout the cerebral cortex. Immunoelectron microscopic examination showed the immunoreactivity in the PSD, while neurofilament M was not in the PSD. Thus alpha-internexin and neurofilament M are differentially localized in neuronal cells. Alpha-internexin content in the PSD fraction was relatively high even before the period of synaptogenesis and the content in the fraction was unchanged between young and adult rats (2-6 weeks old). These results suggest a role of alpha-internexin for early development and organization of the PSD.

Amino Acid Sequence↗
PubMed1997

Intracytoplasmic inclusion bodies of the substantia nigra in myotonic dystrophy. Immunohistochemical observations.

We recently reported a significantly higher incidence of intracytoplasmic inclusion bodies (IIBs) of the substantia nigra in patients with myotonic dystrophy (MyD) than in age-matched controls. The changes are, per se, not specific, since a small percentage of disease and normal controls also showed similar inclusions. To elucidate the pathological significance of the inclusion in MyD, we studied immunohistochemical characteristics of IIBs of the substantia nigra in eight patients with MyD. Many IIBs showed moderately intense immunoreactivity for ubiquitin, microtubule-associated protein (MAP) 1 and MAP 2. However, the IIBs did not react with any of the following: anti-neurofilament protein antibodies (Abs) (68, 160 and 200 kDa), anti-neuron-specific enolase antibody (Ab), anti-tau Ab, anti-tubulin Abs (alpha and beta), anti-paired helical filament Ab, anti-actin Ab, anti-phosphorylated epitope of neurofilaments Ab, anti-synaptophysin Ab, anti-myelin basic protein Ab, anti-actin Ab and anti-glial fibrillary acidic protein Ab. Our results suggest that IIBs of the substantia nigra in MyD are related to an alteration of neuronal cytoskeleton metabolism affecting microtubular proteins in conjunction with activation of ubiquitin proteolytic systems.

Aged↗