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Biomedical subjects

K Kosaka

Publications and source records attributed to K Kosaka.

At least 73 records · Page 4Linked to original sources
PubMed1999

Epworth Sleepiness Scale and sleep studies in patients with obstructive sleep apnea syndrome.

Excessive daytime sleepiness (EDS) is the major symptom of patients with obstructive sleep apnea syndrome (OSAS). In this study, we examined the relationship between subjective EDS scored with the Epworth Sleepiness Scale (ESS), objective EDS measured with the multiple sleep latency test (MSLT) and sleep variables evaluated with polysomnography for patients with OSAS. Subjects were 10 patients (51.7+/-19.0 years old). The average ESS and MSLT scores were 10.6+/-5.6 and 7.7+/-5.6, respectively. There was no significant relationship between ESS and MSLT. The Multiple Sleep Latency Test had a significant negative relationship with the number of awakenings and the apnea/hypopnea index. No relationship was found between nocturnal hypoxia and either ESS or MSLT. Our findings suggest that objective EDS in OSAS is related with fragmentation of sleep, and that several patients are not aware of their EDS.

Adult↗
PubMed1999

Polysomnographic and urodynamic changes in a case of obstructive sleep apnea syndrome with enuresis.

A 53-year-old female patient with obstructive sleep apnea syndrome was reported. She had complained of enuresis as well as a 15-year history of snoring, but she had no complaint of sleep and awake disturbance. Polysomnographic study showed repeated obstructive apnea and hypopnea with an apnea/hypopnea index of 52.6, and severe oxygen desaturation during sleep. On cystometography during sleep, the changing amplitude of the spike wave corresponds to the changes of respiratory efforts against a closed upper airway. The patient was treated successfully with imipramine and acetazolamide for the obstructive sleep apnea and enuresis. Apnea/hypopnea index, nocturnal oxygen desaturation, and sleep architecture were improved, and enuresis completely disappeared. Cystometrography during sleep showed that the average amplitude of the spike wave tended to be low. Percentage urinary volume during sleep compared with 24 h volume was significantly reduced. We considered that the enuresis was mainly related to increased intra-abdominal pressure produced by respiratory efforts and enhanced nocturnal urine production.

Acetazolamide↗
PubMed1999

Alterations of muscarinic acetylcholine receptor subtypes in diffuse lewy body disease: relation to Alzheimer's disease.

OBJECTIVES: Dementia associated with Lewy bodies in cortical and subcortical areas is classified as dementia of the non-Alzheimer type and termed diffuse Lewy body disease (DLBD). The generic term "dementia with Lewy bodies (DLB)" was proposed in the international workshop on Lewy body dementia to include the similar disorders presenting Lewy bodies. In DLB, a lower level of choline acetyltransferase (ChAT) activity in the neocortex was found compared with that in Alzheimer's disease. The purpose of the present study was to determine the total amount of muscarinic acetylcholine receptors (mAChRs) and relative proportion of each subtype (m1-m4) of mAChRs in the frontal and temporal cortex of seven DLBD and 11 Alzheimer's disease necropsied brains. METHODS: A [(3)H]quinuclidinyl benzilate (QNB) binding assay and an immunoprecipitation assay using subtype-specific antibodies were performed. Each antibody was raised against fusion proteins containing peptides corresponding to the third intracellular (i3) loops of the respective mAChR subtype. RESULTS: The total amounts of mAChRs were significantly lower in the preparations of temporal cortices from DLBD and Alzheimer's disease than in those from dead controls (seven cases). In both diseases, the proportion of the m3 receptor in the frontal cortex was significantly increased and that of the m4 receptor in the temporal cortex was significantly decreased compared with the control specimens. The proportions of the m1 and m2 subtypes were significantly different in the temporal cortex. The proportion of the m1 receptor was significantly greater in the DLBD brains, whereas that of the m2 receptor was significantly greater in the Alzheimer's disease brains than in the controls. CONCLUSIONS: The m1 receptor is the major subtype in the cerebral cortex, and m2 is known to be present at presynaptic terminals. The higher proportions of m1 in DLBD and m2 in Alzheimer's disease suggest that the manner of degeneration in the cholinergic system is different between the diseases. It is hypothesised that a severe depletion of presynaptic cholinergic projective neurons causes the upregulation of m1 receptor in the temporal cortex in DLBD.

Aged↗
PubMed1999

Preparation and pharmacological evaluation of novel glycoprotein (Gp) IIb/IIIa antagonists. 1. The selection of naphthalene derivatives.

The synthesis and design using molecular modeling techniques for non-peptide, low molecular weight novel fibrinogen receptor (glycoprotein IIb/IIIa: Gp IIb/IIIa) antagonists, is reported. We used a highly potent serine protease inhibitor, Nafamostat, having an amidinonaphthyl unit as the starting compound. The compounds 4-(6-amidino-2-naphthylaminocarbonyl)phenoxyacetic acid (5a) and 4-(6-amidino-2-naphthalenecarboxamido)phenoxyacetic acid (5b) inhibited adenosin-5'-diphospate (ADP)-induced aggregation of human platelet-rich plasma (PRP) with IC50 values of 0.05 and 0.07 microM, respectively, and had lost their ability to inhibit a variety of serine proteases, including thrombin, factor Xa, plasmin and trypsin.

Adenosine Diphosphate↗
PubMed1999

Preparation and pharmacological evaluation of novel glycoprotein (Gp) IIb/IIIa antagonists. 2. Condensed heterocyclic derivatives.

A novel series of platelet receptor glycoprotein (Gp) IIb/IIIa antagonists with condensed heterocycles as their basic core was synthesized. In an in vitro assay, trans-4-(5-amidinobenzofuran-2-carboxamido)cyclohexyloxyacetic+ ++ acid 17e and trans-3-[4-(5-amidinobenzofuran-2- carboxamido)cyclohexyl]propionic acid 17f produced marked inhibitions with IC50 values of 0.018 and 0.006 microM, respectively in a human platelet adenosin-5'-diphospate (ADP)-induced aggregation assay; they also exhibited a wide spectrum of inhibition toward major aggregation agonists (ADP, collagen, thrombin, PMA (tumor promoter) and arachidonic acid). These compounds were > 2-3 orders of magnitude more effective in inhibiting platelet aggregation than human umbilical vein endothelial cell (HUVEC) binding. The oral administration of 10 mg/kg of either 17e and 17f to guinea pig, resulted in a 60% inhibition of ex vivo platelet aggregation after 5 h. Oral administration of ethyl trans-4-(5-amidinoben-zofuran-2- carboxamido)cyclohexyloxyacetate 18e (10 mg/kg) resulted in 80% inhibition of platelet aggregation in dogs for 6 h after oral administration with a return to baseline by 24 h. Ethyl trans-3-[4-(5-amidinobenzofuran-2-carboxamido)cyclohexyl]propionat e 18f (AR0598) produced 80% inhibition for 5 h after oral administration. Prodrug 18e showed a good profile in dogs with a long duration of action. 18e (AR0510) was selected as suitable clinical candidate for development as an orally active antithrombotic agent.

Adenosine Diphosphate↗
PubMed1999

[An autopsied case of subacute progressive dementia with flactuated disturbance of consciousness, myoclonus and periodic synchronous discharges on EEGs].

We present an autopsied case which developed progressive dementia at the age of 45. EEGs showed periodic synchronous discharges (PSD) when he showed fluctuated cloudy consciousness with myoclonus. Cerebrospinal fluid examination showed mild to moderate increase in protein and monocytes for duration of illness, but antivirotics and antibiotics were not effective. He was not apallic even at the terminal stage when computed tomography (CT) revealed marked cerebral atrophy, and died of pneumonia 27 months after onset. He was clinically diagnosed as having Creutzfeldt-Jakob disease (CJD) because of subacute progressive dementia, myoclonus and PSD. Neuropathological examination revealed marked brain atrophy with severe neuronal loss and gliosis in the cerebral cortex and subcortical nuclei, although no spongiform degeneration was found. Senile plaques, neurofibrillaly tangles, argyrophilic glial inclusions and glial nodules were not detected. Prion protein immunoreactivity was negative. Therefore, this case can not be neuropathologically diagnosed as having CJD, Alzheimer's disease, non-Alzheimer-type degenerative dementias or any encephalitis. This case might have suffered from an unknown new disease.

Brain↗
PubMed1999

[Acquired pendular nystagmus after pontine hemorrhage].

A 60-year-old hypertensive woman had a pontine hemorrhage that caused slight right hemiplegia, deep sensory disturbance on her right side and dysarthria. Three months after the stroke, she was transferred to our hospital for rehabilitation. Approximately 6 months later, she gradually began to complain of the visual oscillation. Continual, unceasing conjugate vertical/rotatory eye movements were observed. Fixation was momentary at best because of an inability to dampen the spontaneous eye movements. Electrooculography (EOG) showed bilateral vertical/rotatory sinusoidal eye movements of 2.5 Hz frequency and 10- to 35-degree amplitude. Both vertical and horizontal optokinetic nystagmus were absent. Caloric stimulation did not evoke any responses bilaterally. There were no rhythmical movements at similar frequencies in other parts of the body such as palatal myoclonus. MRI revealed not only hematoma mainly at the dorsal pontine tegmentum but also hypertrophy of the inferior olive nucleus, suggesting disruption of the central tegmental tract. Lesions of this tract may be one cause of pendular nystagmus. Several drug therapies were investigated for the nystagmus. There was no response to baclofen 15 mg. Trihexyphenidyl 4 mg was discontinued because of drug-induced hallucinations. Tiapride 600 mg and phenobarbital 90 mg were each slightly effective in reducing both frequency and amplitude of nystagmus. Treatment with clonazepam 1 mg resulted in the striking disappearance of nystagmus. She was aware of this and no longer experienced oscillopsia. Despite the visual benefit, however, the patient did not wish to continue this drug because of drowsiness and muscle relaxation. The potential long-term therapeutic application of clonazepam should be further investigated. To our knowledge, there have been no reports of successful treatment in acquired pendular nystagmus with clonazepam. Therefore, based on this favorable experience, it is suggested that clonazepam should be added to the list of potential therapies for pendular nystagmus.

Anticonvulsants↗
PubMed1998

Degenerative terminals of the perforant pathway are human alpha-synuclein-immunoreactive in the hippocampus of patients with diffuse Lewy body disease.

We investigated the hippocampal pathology in diffuse Lewy body disease (DLBD) using alpha-synuclein immunohistochemistry. Ubiquitin-positive intrahippocampal structures caused by the degeneration of terminal axons of the perforant pathway were observed to be alpha-synuclein immunoreactive. These alpha-synuclein-positive degenerative terminals contained granulo-filamentous or vesiculo-tubular components similar to those of Lewy bodies (LB) immunoelectron microscopically, suggesting that alpha-synuclein may abnormally aggregate into filamentous or membranous cytoskeletal components including neurofilaments and synaptic vesicles in DLBD. A 'dying back' degenerating process due to a blockage of axonal transport may explain why the degenerative terminals and LB share similar alpha-synuclein-positive components, but the origin cells of the perforant pathway contain only a few LB.

Aged↗
PubMed1998

Mutation involving cytochrome P450IID6 in two Japanese patients with neuroleptic malignant syndrome.

Cytochrome P450IID6 (CYP2D6) plays an important role in the hepatic metabolism of various psychotropic drugs. We detected a mutation of the CYP2D6 gene in two patients who previously had episodes of neuroleptic malignant syndrome (NMS). They were homozygous for a mutated CYP2D6J allele conferring a poor-metabolizer phenotype. Possession of this trait may contribute to susceptibility to NMS.

Alleles↗
PubMed1998

Ubiquitin-immunohistochemical investigation of atypical Pick's disease without Pick bodies.

Six cases of atypical Pick's disease (PD) without Pick bodies (PB) were examined immunohistochemically. These cases showed severe neuronal loss with gliosis predominantly in the temporal cortices. Ubiquitin immunohistochemistry revealed ubiquitin-positive intraneuronal inclusions in the dentate gyrus and ubiquitin-positive neurites in the cerebral cortex. In the dentate gyrus, the dendrites in the stratum moleculare as well as the intraneuronal inclusions in the granular cells were positively stained. Both structures were composed of ubiquitin-positive ribosome-like granular components and a few filamentous components immunoelectron-microscopically. In the cerebral cortex, ubiquitin-positive neurites were distributed in layers II-IIIab and layers V-VI, and were considered to be the distal dendrites from the small neurons. The dendrites and perikarya of these neurons contained ubiquitin-positive components similar to those in the dentate gyrus. Some ubiquitin-positive neurites were also found in the hippocampal subiculum, amygdala and striatum. The results of this study suggest that the granular cells in the dentate gyrus and the small neurons in the cerebral cortex share common ubiquitin-related and ribosome-associated abnormalities in both the perikarya and dendrites, that the degeneration of the perforant pathway caused by the parahippocampal lesion participates in the ubiquitin related abnormalities in the granular cells, and that PD cases with and without PB have common affected neurons, as shown immunohistochemically.

Aged↗
PubMed1998

Regional quantitative analysis of tau-positive neurons in progressive supranuclear palsy: comparison with Alzheimer's disease.

In patients with progressive supranuclear palsy (PSP), various tau-positive abnormal structures are found in the cerebral cortex as well as in the subcortical nuclei. Similar tau-positive abnormalities are also identified in cortico-basal degeneration (CBD). It is therefore questionable as to whether PSP can be neuropathologically differentiated from CBD. It also remains nuclear whether neurofibrillary tangles (NFT) in the cerebral cortex of PSP patients consist of PSP-NFT or concomitant Alzheimer's disease (AD)-NFT, although there have been some reports suggesting that PSP- and AD-NFT are different with respect to distribution pattern and biochemical character. In this study, a regional quantitative analysis of the distribution and antigenicity of tau-positive neurons (TPN) was performed in PSP cases and compared with that in AD cases. TPN consisted of NFT with tangle-formation and pretangle neurons (PN) without tangle-formation. In addition, NFT were subdivided into mature and immature NFT according to the difference of staining properties with anti-tau-related antibodies. The comparison of the TPN of the PSP cases with those of the AD cases revealed that the degree of tangle-formation in the TPN of AD was similar in all of the examined regions, while that in the TPN of PSP varied according to the region and case. Moreover, the NFT in the PSP and AD cases had different distributions according to the cortical layer and subnucleus, even in the common predilection sites of PSP and AD, suggesting that NFT in these regions of the PSP cases consist mainly of PSP-NFT. In addition, the PSP cases could be divided into two groups according to the difference of the tangle-formation of TPN; group I with typical PSP pathology and group II with atypical PSP pathology similar to CBD. This suggests that there is a continuity between PSP and CBD with respect to the distribution and antigenicity of TPN.

Aged↗
PubMed1998

Chemically defined neuron groups and their subpopulations in the glomerular layer of the rat main olfactory bulb: III. Structural features of calbindin D28K-immunoreactive neurons.

The present study analyzed three-dimensional structural features and synaptic contacts of morphologically and chemically identified calbindin D28K-immunoreactive neurons in the glomerular layer of the rat main olfactory bulb by means of combined confocal laser scanning light microscopy, high-voltage electron microscopy and electron microscopic serial section/three-dimensional reconstruction. Most of calbindin D28K-immunoreactive neurons were identified as the periglomerular cell type by combined high-voltage electron microscopic and confocal laser scanning light microscopic observations, and the minority were the short-axon cell type and others. The combined confocal laser scanning light microscopic and electron microscopic study revealed that the calbindin D28K-immunoreactive neurons exhibited unique synaptic contact patterns; they received asymmetrical synapses from presumed mitral/tufted dendrites and made conversely symmetrical synapses with them. About 30% of asymmetrical postsynaptic sites and about 40% of symmetrical presynaptic sites formed reciprocal pairs of synapses. Calbindin D28K-immunoreactive dendrites and somata also received synapses from GABA-like-immunoreactive profiles containing numerous pleomorphic, and a few dense-cored, vesicles. On the other hand, surprisingly, calbindin D28K-immunoreactive neurons had almost no synaptic contacts from olfactory nerve terminals. The present study clearly revealed that calbindin D28K-immunoreactive neurons are a type of periglomerular cell involving unique synaptic contacts that have not been reported so far, and thus indicated that so-called periglomerular cells should be heterogeneous in their synaptic connections as well as in their chemical and structural features.

Animals↗
PubMed1998

Heparan sulfate proteoglycans recognize ghost Pick bodies.

An anti-heparan sulfate proteoglycan (HSPG) monoclonal antibody (3G10) recognized irregular round structures (IRSs) of various sizes adjacent to tau-positive intracellular Pick bodies (PBs) in the granular cell layer of the dentate gyrus and the superficial layers of the parahippocampal and other temporal gyri in Pick's disease. Some intracellular PBs were also weakly immunostained with 3G10. Only part of the IRSs were double-immunostained with 3G10 and anti-tau antibody. Immunoelectron-microscopic examination revealed that IRSs were composed of aggregated fibrillary structures with a diameter of 10-20 nm, corresponding to the appearance of ghost PBs. These findings suggest that 3G10 identifies ghost PBs better than intracellular PBs, and that heparan sulfate proteoglycans are involved in the process of PBs extinction.

Antibodies, Monoclonal↗
PubMed1998

A new informative Alw 26 I polymorphism in exon 10 of the human low density lipoprotein receptor gene. Application to prenatal diagnosis. Mutations in brief no. 145. Online.

Using DNA sequencing of the coding and exon flanking regions of the low density lipoprotein receptor (LDLR) gene we identified an Alw26 I site in exon 10 by a transition G142A. The alleles are represented by one uncut fragment (A1=108bp) or two fragments (A2=82bp and 26 pb). Two other fragments (72bp and 16bp) were systematically found within the amplified product. The alleles were detected in 157 unrelated French Caucasians with A1 frequency = 0.58 and A2=0.42. The observed heterozygoty was 44.5%. Homozygous familial hypercholesterolemie (FH) has a severe clinical picture leading to death during childhood. Because it is very informative, the present polymorphism was very useful as genetic marker for clinical diagnois and counseling as we described in linkage analysis at the LDLR locus for prenatal diagnosis in a fetus who could inherit two LDLR mutant alleles from FH heterozygote parents.

DNA-Cytosine Methylases↗