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Biomedical subjects

K Okamoto

Publications and source records attributed to K Okamoto.

At least 235 records · Page 13Linked to original sources
PubMed2000

Accumulation of NACP/alpha-synuclein in lewy body disease and multiple system atrophy.

OBJECTIVES: NACP/alpha-synuclein is an aetiological gene product in familial Parkinson's disease. To clarify the pathological role of NACP/alpha-synuclein in sporadic Parkinson's disease and other related disorders including diffuse Lewy body disease (DLBD) and multiple system atrophy (MSA), paraffin sections were examined immunocytochemically using anti-NACP/alpha-synuclein antibodies. METHODS: A total of 58 necropsied brains, from seven patients with Parkinson's disease, five with DLBD, six with MSA, 12 with Alzheimer's disease, one with Down's syndrome, one with amyotrophic lateral sclerosis (ALS), three with ALS and dementia, one with Huntington's disease, two with progressive supranuclear palsy (PSP), one with Pick's disease, one with myotonic dystrophy, and three with late cerebellar cortical atrophy (LCCA), and 15 elderly normal controls were examined. RESULTS: In addition to immunoreactive Lewy bodies, widespread accumulation of NACP/alpha-synuclein was found in neurons and astrocytes from the brainstem and basal ganglia to the cerebral cortices in Parkinson's disease/DLBD. NACP/alpha-synuclein accumulates in oligodendrocytes from the spinal cord, the brain stem to the cerebellar white matter, and inferior olivary neurons in MSA. These widespread accumulations were not seen in other types of dementia or spinocerebellar ataxia. CONCLUSION: Completely different types of NACP/alpha-synuclein accumulation in Parkinson's disease/DLBD and MSA suggest that accumulation is a major step in the pathological cascade of both diseases and provides novel strategies for the development of therapies.

Aged↗
PubMed2000

Redox regulation of the nuclear receptor.

Redox regulation is currently considered a mode of signal transduction for coordinated regulation of a variety of cellular processes. Transcriptional regulation of gene expression is also influenced by the cellular redox state, for example, through the oxidoreductive modification of transcription factors. The nuclear receptors act as ligand-dependent transcription factors and are considered to be one of the key regulators of essential biological processes. Using a glucocorticoid receptor as a model, we show that redox regulation of receptor function is one of the dynamic cellular responses to environmental stimuli.

Animals↗
PubMed2000

Hydrolysis of beta-glucosyl ester linkage of p-hydroxybenzoyl beta-D-glucose, a chemically synthesized glucoside, by beta-glucosidases.

To investigate the hydrolysis of glucosyl esters by beta-glucosidase, p-hydroxybenzoyl beta-D-glucose (pHBG) was chemically synthesized. The hydrolytic activity of some beta-glucosidases for pHBG was compared to that for p-nitrophenyl beta-glucoside (pNPG). The Clavibacter michiganense and Flavobacterium johnsonae enzymes could hydrolyze pHBG and steviol glycosides which are natural glucosyl esters. The commercial beta-glucosidase originating from Caldocellum saccharolyticum also hydrolyzes pHBG despite having no activity for steviol glycosides. The beta-glucosidase from Aspergillus niger cleaved the glucosyl ester linkage much more weakly than the glucosidic linkage. The pH-activity profile for the hydrolysis of pHBG was similar to that of pNPG by the C. saccharolyticum beta-glucosidase. The similar profiles for these substrates suggested that the active site for the glucosyl ester chemically resembles that for glucoside with respect to catalysis. Kinetic analysis of the C. saccharolyticum beta-glucosidase for mixed substrates of pHBG and pNPG showed that the hydrolysis of pHBG competed with that of pNPG. This result indicated that there is only one active site for both the glucosyl ester and glucoside. Mass spectroscopic analysis of the hydrolysates of pHBG in H218O suggested that beta-glucosidase hydrolyzes glucosyl esters between the anomeric carbon of glucose and the carbonyl oxygen, not between the carbonyl carbon and the carbonyl oxygen.

Journal Article↗
PubMed2000

Hydrolysis of beta-galactosyl ester linkage by beta-galactosidases.

p-Hydroxybenzoyl beta-galactose (pHB-Gal) was synthesized chemically to examine the hydrolytic activity of beta-galactosyl ester linkage by beta-galactosidases. The enzyme from Penicillium multicolor hydrolyzed the substrate as fast as p-nitrophenyl beta-galactoside (pNP-Gal), a usual substrate with a beta-galactosidic linkage. The enzymes from Escherichia coli and Aspergillus oryzae hydrolyzed pHB-Gal with almost the same rates as pNP-Gal. The enzymes from Bacillus circulans, Saccharomyces fragilis, and bovine liver showed much lower activities. pH-activity profiles, inhibition analysis, and kinetic properties of the enzymic reaction on pHB-Gal suggested that beta-galactosidase had only one active site for hydrolysis of both galactosyl ester and galactoside. The Penicillium enzyme hydrolyzed pHB-Gal in the presence of H218O to liberate galactose containing 18O. This result suggests the degradation occurs between the anomeric carbon and an adjacent O atom in the ester linkage of pHB-Gal.

Animals↗
PubMed2000

Purification and some properties of a beta-glucosidase from Flavobacterium johnsonae.

Flavobacterium johnsonae was isolated as a microorganism that produced a beta-glucosidase with hydrolytic activity of beta-glucosyl ester linkages in steviol glycosides. The enzyme was purified to homogeneity from a cell-free extract by streptomycin treatment, ammonium sulfate fractionation, and column chromatographies on S-Sepharose and phenyl-Toyopearl. The molecular mass of the purified enzyme was about 72 kDa by SDS-PAGE. An isoelectric point of pI 8.8 was estimated by isoelectric focusing. The enzyme was most active at pH 7.0, and was stable between pH 3.0 and 9.0. The optimum temperature was 45 degrees C, and the enzyme was stable below 35 degrees C. The enzyme hydrolyzed glucosyl ester linkages at site 19 of rebaudioside A, stevioside, and rubusoside, although it could not degrad beta-glucosidic linkages at site 13 of rebaudioside B or steviol bioside. The enzyme acted on aryl beta-glucosides such as p-nitrophenyl beta-glucoside, phenyl betaglucoside, and salicin, and glucobioses such as sophorose and laminaribiose. The enzyme activity on Rub was inactivated completely by Hg2+, and reduced by Fe3+, Cu2+, p-chloromercuric benzoate, and phenylmethylsulfonyl fluoride (residual activity; 67.9-84.8%). The pNPG hydrolysis was also inactivated to almost the same degrees. Kinetic behaviors in the mixed substrate reactions of rebaudioside A and steviol monoside, and of steviol monoglucosyl ester and phenyl beta-glucoside suggested the glucosidic and glucosyl ester linkages were hydrolyzed at a single active site of the enzyme.

Chromatography, High Pressure Liquid↗
PubMed2000

Detection of thermophilic Campylobacter from sparrows by multiplex PCR: the role of sparrows as a source of contamination of broilers with Campylobacter.

The best combination of primers and the annealing temperature of multiplex PCR for Campylobacter jejuni, Campylobacter coli, and Campylobacter lari were examined. The multiplex PCR was able to detect type strains of the three species. All results of identification of wild strains (30 strains of C. jejuni, 20 strains of C. coli, and 4 strains of C. lari) by the multiplex PCR coincided with those of the conventional biochemical identification tests, suggesting that the multiplex PCR can simultaneously differentiate C. jejuni, C. coli, and C. lari from wild strains of campylobacters easily and rapidly. Campylobacters were detected from sparrow feces by the multiplex PCR and antimicrobial sensitivities of the strains were determined to discuss the role of sparrows in contamination of broilers with C. jejuni. Three out of 13 strains of C. jejuni isolated from sparrow feces showed quinolone resistance. From the frequent use of quinolones for treatment of industrial animals like chickens, pigs, and cows, the three strains of quinolone-resistant C. jejuni in sparrows must have been originated from those industrial animals. Sparrows that have quinolone-resistant C. jejuni were considered to have contacted with industrial animals or thier feed. It may be presumed, on the contrary, that C. jejuni in sparrows could be a potential source of contamination of broilers.

Animals↗
PubMed2000

Interferon-gamma stimulates the expression of CX3CL1/fractalkine in cultured human endothelial cells.

CX3CL1/Fractalkine, a CX3C chemokine, is a potent agonist for the chemotaxis and adhesion of monocytes and lymphocytes. It was first identified as a membrane protein in endothelial cells activated with IL-1 or TNF-alpha. We have found the enhanced expression of fractalkine in human umbilical vein endothelial cells stimulated with interferon-gamma (IFN-gamma). Pretreatment of the cells with cycloheximide did not inhibit the expression of fractalkine mRNA. The majority of fractalkine protein was found in the cell lysate, and an antibody-blocking experiment disclosed that fractalkine contributes to the adhesion of mononuclear cells to endothelial monolayers stimulated with IFN-gamma. Vascular endothelial cells produce fractalkine in response to IFN-gamma, and this may play an important role in immune responses by eliciting a traffic of mononuclear cells through the vascular wall.

Antibodies↗
PubMed2000

Coordinate regulation of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 expression in human vascular smooth muscle cells.

The expression of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) by human vascular smooth muscle cells (SMC) was monitored as a function of the phenotypic modulation in vitro. Cell phenotype was manipulated by varying serum concentration and cell density. Synthetic phenotype was characterized by a minimum expression of the contractile proteins and a maximal proliferation rate. Contractile phenotype was quiescent and expressed a maximal level of contractile proteins. Synthetic cells expressed the highest levels of both MMP-1 and TIMP-1 and displayed maximal collagenolytic activity. No significant change was detected in MMP-2 expression or catalytic activity. Enzyme immunoassays revealed that MMP-1 expression fell by 77+/-2.4-95+/-0.5%, and that of TIMP-1 by 34+/-0.5-59+/-1.9%, as the cells acquired a contractile phenotype. The level of the MMP-1/TIMP-1 complex was similarly reduced by 78+/-2.9-85+/-1.6%. These data demonstrate that the expression of MMP-1 and TIMP-1 are coordinately regulated with SMC phenotype.

Adult↗
PubMed2000

[Feeling of well-being and family contacts in community elderly residents].

The aim of this study is to explore the factors associated with feelings of well-being in 683 community-dwelling elderly residents, aged 65 years and over using a self-administered questionnaire. The feeling of well-being was rated using a single question item constructed by The Japanese Association for Cerebro-cardiovascular Disease control (JACD), and then subjects were divided into two groups according to answer categories: happiness and unhappiness. There was no statistically significant difference in the proportion of subjects with happiness between males and females, or among age groups. Even when interaction among multiple factors were adjusted by logistic regression analysis, a high frequency of conversation with family was statistically significantly related to happiness, and the odds ratio of it was highest among all other factors. The odds ratio of high frequency of conversation with family was higher among the elderly aged 75 and over than among those aged 65-74. These results suggest that the construction of communication between the elderly and their family through conversation could contribute to feelings of well-being in the elderly.

Aged↗
PubMed2000

[Agreement between reports by the aged themselves and by their family members on physical and psychological status].

We examined the agreement between reports about physical and psychological status obtained from 286 community-dwelling elderly persons aged 65 years and over (subjects) and their family members (proxies). A total of 205 subject-proxy pairs were studied. Information from subjects was obtained by a self-administered questionnaire, and proxy respondents by an interview-administered questionnaire between Nov. 1997, and Feb 1998. Agreement was assessed by percent agreement and statistical kappa values. Percent agreement ranged from a low of 50.8 for anxiety to a high of 90.4 for difficult in swallowing. Kappa values ranged from a low of 0.21 for anxiety to a high of 0.67 for high frequency of falling. Median kappa values were higher in summary measure of physical status (0.52) than in that of psychological status (0.39). Compared to subjects, their partners tended to report higher level both in physical status and in psychological status, except for sleep compliance and introversion. The median kappa was 0.54 for spouses, whereas it was 0.39 for family members other than spouses. Overall, our finding indicated that partners could be aware of the concrete and directly-observable variables of physical status such as constipation, difficult in swallowing, but not so for subjective variables as psychological status such as depressed condition and introversion. Our results also suggested that the degree of agreement of proxy's perception and understanding of lifestyle of the elderly is closely related to health status of the elderly.

Aged↗
PubMed2000

[Renal cell carcinoma in acquired cystic disease of the kidney manifested by spontaneous renal hemorrhage].

Acquired cystic disease of the kidney (ACDK) is a common phenomenon in long-term adult dialysis patients with end-stage renal disease. Renal hemorrhage and neoplastic transformation of the cyst are two major complications of this entity and these two can occur independently. Here we describe a 65-year-old man with a history of hemodialysis-dependent end-stage renal failure for 12 years presented with macroscopic hematuria and right flank pain. Investigations revealed right massive perirenal and subcapsular hematoma with ACDK. The hemorrhagic state required nephrectomy of the right kidney. Histological study showed ACDK with massive subcapsular and perinephric hematoma containing minimal clear cell carcinoma region(0.5 cm in diameter). Although a causal relationship between renal hemorrhage and renal cell carcinoma in this patient was unproven, the present case suggests radical surgery can be a recommendable treatment modality of hemorrhagic ACDK.

Aged↗
PubMed2000

Effects of Fusobacterium necrophorum subspecies necrophorum on extracellular matrix of tissue-cultured bovine kidney cells.

The effects of Fusobacterium necrophorum subsp. necrophorum on the extracellular matrix were investigated. The toxic preparation from the culture induced reduction in the number of tissue-cultured bovine kidney cells. The exposed cells often manifested partial loss of cytoplasm and were morphologically irregular. Scanning electron microscopy demonstrated partial loss of the microvilli on the exposed cells and roughness of the cell surfaces. Finally, sodium dodecyl sulphate polyacrylamide gel electrophoresis profiles revealed complete degradation of bovine collagen type 1 after treatment with the toxic preparation. This degradation was inhibited by the addition of homologous antiserum. These findings indicate that the degradation may contribute to the establishment of the infection caused by F.n. subsp. necrophorum.

Animals↗
PubMed2000

[Empyema thoracis accompanied by hyperammonemic encephalopathy].

A 50-year-old man was admitted to our hospital due to consciousness disturbance. On admission, he was comatose (200 on the Japan Coma Scale) but brain computed tomographic (CT) scans were normal. Chest radiographs and CT scans on admission revealed massive pleural effusion in the right hemithorax. A culture of purulent pleural fluid yielded three species of anaerobes, including Bacteroides fragilis. Laboratory examinations revealed markedly elevated WBC count, CRP, and serum ammonia (586 micrograms/dl). However, liver function was almost normal and no other metabolic disorders were demonstrated. After the initiation of antibiotic therapy and pleural drainage, the patient's cousciousness level gradually improved in parallel with decreasing serum levels of ammonia and CRP. Because no other potential causes of hyperammonemia were observed, we concluded that the consciousness disturbance was due to hyperammonemia presumably caused by a urease-producing anaerobe infecting the right pleural space.

Ammonia↗
PubMed2000

Band-suppressed restoration of X-ray images blurred by body movement.

The restoration of X-ray images that have been blurred due to body movement are discussed. The observation system for these images is described using a mathematical model, and several restoration filters composed of a series of such models are proposed. These filters restore band-suppressed approximations of the original images. In addition, redundancy is introduced into these restoration filters in order to suppress additive noise. These filters are expanded to be applicable not only to parallel translations, but also to rotations by coordinate transformation. The proposed methods are applied to blurred X-ray images of a bone model of the elbow joint. The parameters of the restoration filter are estimated using a marker attached to the subject as a reference signal.

Artifacts↗
PubMed2000

[A resected case of large cell neuroendocrine carcinoma].

Large cell neuroendocrine carcinoma (LCNEC) is a rare lung cancer and it has a poor prognosis. We describe our experience with a patient in whom LCNEC was diagnosed. 38-year-old woman who complained of a cough and low grade fever up was admitted to our hospital. Chest X-ray and CT shoued 6.5 x 5.0 mass in rt-S1 and S2. It was suspected as LCNEC of the right lung because of broncopscopic cytology. The upper lobectomy of the right lung and desection of mediastinal lymph nodes were performed. Pathological diagnosis was III B (T2N2M0) LCNEC. Four weeks after the operation, one cycle of chemotherapy (CDDP + VP - 16 + VDS) and one cycle of chemoradiotherapy (thoracic radiation of 40 Gy, CDDP + 5 - FU) were performed. There are no findings of tumor recurrence 7 months after operation.

Adult↗
PubMed2000

[Hepatic function after surgical repair of constrictive pericarditis].

We report the results of long-term follow up in 9 patients who underwent pericardiectomy for constrictive pericarditis. In order to test whether if congestive liver dysfunction due to the disease could be reversible or not after the surgical repair, the patients were evaluated by indocyanine green (ICG) clearance test. All the patients improved in NYHA classification after long-term periods following surgical repairs. The percentage of ICG retention at 15 minutes (ICG-R15) improved in most of the patients. However, two patients who had a long history from the onset before surgery became worse in ICG-R15. From the above reports, reversibility of hepatic function might be dependent on the duration of liver congestion before surgical repairs.

Adult↗