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Biomedical subjects

M Okamoto

Publications and source records attributed to M Okamoto.

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

Focal cerebral ischemia-induced escape deficit in rats is ameliorated by a reversible inhibitor of monoamine oxidase-a: implications for a novel animal model of post-stroke depression.

The present investigation was conducted to examine whether a reversible inhibitor of monoamine oxidase (MAO)-A, T-794, affects the shuttle-box escape deficit induced by transient middle cerebral artery (MCA) occlusion (MCAO). MCA-occluded and sham-operated rats (surgery on day 0) were subjected to daily shuttle-box session from day 7 to 9 (training series) and from day 13 to 15 (test series) and received twice daily administration of T-794 (10 mg/kg p.o., b.i.d.) or vehicle from the evening of day 9. In the final shuttle-box session of test series (day 15), while MCA-occluded-vehicle-treated rats showed significantly more escape failures than sham-operated-vehicle-treated rats, the failures made by MCA-occluded rats were significantly decreased by T-794 to the level of the sham-operated group. Additionally, biochemical examination was conducted after behavioral evaluation to examine possible involvement of the brain monoamine system in the observed behavioral syndrome. In occluded hemisphere of MCA-occluded rats, catecholamine levels were decreased and ratios of deaminated metabolite to corresponding monoamine were increased compared with the respective values of the sham-operated group, and these changes were reversed by T-794. Results are discussed in terms of possible relevance of the MCAO-induced escape deficit to post-stroke depression.

Animals↗
PubMed2000

Cardiac tumor biopsy under the guidance of intracardiac echocardiography.

Transthoracic echocardiography or transesophageal echocardiography is sometimes useful in intracardiac tumor biopsy. Intracardiac echocardiography was used as an alternative to either of these for performing a biopsy of a right cardiac tumor in a 79-year-old woman. The procedure was well tolerated and no complications occurred. Histopathological findings and immunohistological staining were compatible with the diagnosis of neurogenic sarcoma.

Aged↗
PubMed2000

Beneficial application of quantitative coronary angiography (edge detection algorithm) in analysis of dissected coronary arteries to predict long-term patency.

The present study evaluated the application of quantitative coronary angiography (edge detection algorithm) for the analysis of coronary dissection lesions after balloon angioplasty. Acute and late results were obtained by the edge detection algorithm in 60 patients with 66 dissected lesions (NHLBI types B-C). The edge detection algorithm delineated the border of the true lumen in 32 lesions (group with automated analysis alone, 48.5%) and included the dissection cap in the analysis in 34 lesions in which manual editing was adjuncted (group with manual editing, 51.5%). In both groups, the minimal lumen diameter after balloon angioplasty obtained by initial automated analysis was correlated to that obtained at the 5.3-month follow-up similarly (r=0.554, p=0.0010 for the group with automated analysis alone and r=0.613, p=0.0001 after automated analysis for the group with manual editing). However, additional manual editing reduced the correlation coefficient (r=0.240, p=0.1707) in the latter group. Thus, in terms of predicting long-term patency, it is reasonable to let the edge detection algorithm decide the measurements in types B and C dissected lesions.

Algorithms↗
PubMed2000

Effects of dietary supplementation with n-3 fatty acids compared with n-6 fatty acids on bronchial asthma.

OBJECTIVE: The effects of perilla seed oil (n-3 fatty acids) on bronchial asthma were compared with the effects of corn oil (n-6 fatty acids) in relation to the pulmonary function and the generation of leukotriene B4 (LTB4) and C4 (LTC4) by leucocytes. METHODS AND SUBJECTS: 14 asthmatic subjects were divided randomly into two groups: one group (7 subjects) consumed perilla seed oil-rich supplementation and the other group (7 subjects) consumed corn oil-rich supplementation for 4 weeks. Generation of LTs by leucocytes and respiratory function were compared between the two groups. RESULTS: The generation of LTB4 and LTC4 by leucocytes tended to increase in subjects (N=7) with corn oil-rich supplementation, and decrease in subjects (N=7) with perilla seed oil-rich supplementation. Significant differences between the two groups were observed in the generation of LTB4 at 2 weeks (p<0.05) and LTC4 at 2 weeks (p<0.05) after dietary supplementation. Significant increases in the value of PEF (p<0.05), FVC (p<0.01), FEV(1.0) (p<0.05) and V(25) (p<0.05) were found in subjects who received perilla seed oil supplementation for 4 weeks. And significant differences in the value of FVC (p<0.05) and FEV(1.0) (p<0.05) were observed between the two groups after 4 weeks of dietary supplementation. CONCLUSION: These results suggest that perilla seed oil-rich supplementation is useful for the treatment of asthma in terms of suppression of LTB4 and LTC4 generation by leucocytes, and improvement of pulmonary function.

Adult↗
PubMed2000

The characteristics of fatigue symptoms and their association with the life style and the health status in school children.

In order to evaluate the characteristics of fatigue symptoms and their association with the life style and the health status, we examined using data accumulated by the longitudinal surveys from 1992 to 1998, in 118 six-year primary school children and 129 second-year junior high school children. The complaints of "drowsiness and dullness", such as "become drowsy" (71%), "give a yawn" (59%) and "want to lie down" (51%), respectively, were most frequently observed. The proportion of these complaints was high before the first morning class, but decreased when the children leave school. Notably, the complaints of "difficulty in concentration" annually have increased. Children with undesirable eating habits, particularly those who often eat salty foods, or poor life style, such as staying up late at night tended to have more complaints of fatigue symptoms. By correlation analysis, these complaints were significantly related to the obesity degree, blood pressure, HDL cholesterol and atherogenic index. These results support the hypothesis that fatigue symptoms increase or are associated with life style and health status. Consequently, it is necessary to improve the life style such as dietary habits and rhythm of life for the reduction of fatigue symptom.

Child↗
PubMed2000

Tracking of cardiovascular risk factors and a cohort study on hyperlipidemia in rural schoolchildren in Japan.

A cohort study was conducted to explore the tracking stability of cardiovascular risk factors and relative risk (RR) of factors relating hyperlipidemia in children. The percentages of children remaining persistently at high risk over a four-year tracking were as follows: body mass index (BMI) 65.0%, total cholesterol (T-c) 60.6%, atherogenic index (AI) 56.4%, high density lipoprotein cholesterol (HDL-c) 50.7%, systolic blood pressure (SBP) 44.2% and diastolic blood pressure (DPB) 39.6%. The order of correlation coefficients over four years was BMI > AI > HDL-c > T-c > SBP > DBP and these coefficients in boys were slightly higher than those in girls. The relative risk (RR) of BMI for AI > or = 3 was elevated (RR=4.36, 95% CI: 1.3-14.1). The incidence and RR for AI > or = 3 increased along with the addition of the selected risk factor number. The RR in children with three selected risk factors rose to 8.39 ( 95% CI: 1.2-38.7 ). The stability of tracking was better for BMI, T-c, AI and HDL-c. As the number of multiple factors increased, so did the RR of higher AI in childhood. These results suggest that preventive activities for hyperlipidemia should be focused on children with multiple cardiovascular risk factors.

Cardiovascular Diseases↗
PubMed2000

How Japanese students characterize information from web-sites.

How 352 Japanese university students regard web-site information was investigated by two kinds of survey. Application of correspondence analysis and cluster analysis to the questionnaire responses to the web-site advertisement showed students regarded a web-site as a new alien medium which is different from current media. Students regarded web-sites as simply complicated, intellectual, and impermanent, or not memorable. Students got precise information from web-sites but they did not use it in making decisions to purchase goods.

Adolescent↗
PubMed2000

SIK (Salt-inducible kinase): regulation of ACTH-mediated steroidogenic gene expression and nuclear/cytosol redistribution.

Possible involvement of salt-inducible kinase (SIK), a serine/threonine protein kinase first cloned from high K+-diet treated rat adrenal glands, in the regulation of steroidogenesis was investigated. Y-1 cells, when treated with ACTH, underwent a rapid change in SIK's mRNA content. It reached the maximum within a few hours and returned to the base after 8 h. In contrast, the levels of mRNAs for CYP11A and StAR protein reached the maxima after 8 h. The SIK's mRNA induction failed to occur in ACTH-, forskolin- or 8-Br-cAMP-treated Kin-7 cells, a mutant cell line of Y-1 with defective cAMP-dependent protein kinase A (PKA). Y-1 cells that overexpress SIK, when treated with ACTH, had significantly repressed levels of mRNAs for CYP11A and StAR protein. Therefore, SIK might have a negative effect on the CYP11A- and StAR protein-gene expression in the early phase of ACTH-mediated steroidogenesis. To further explore the mechanisms underlying this phenomenon, we examined intracellular distribution of the green fluorescence protein (GFP)-tagged SIK. When GFP-SIK was introduced into HeLa cells, the fluorescent signals were detected in the nucleus. In Y-1 cells GFP-SIK was detected both in the nucleus and cytosol, and the signal in the former moved to the latter after ACTH-treatment. The nuclear/cytosol re-distribution of GFP-SIK was also observed in forskolin- or 8-Br-cAMP-treated Y-1 cells, but not in Kin-7 cells. These results suggest that the intracellular re-distribution of SIK in Y-1 cells may depend on the cAMP/PKA signaling pathway and has an important regulatory role in the ACTH-mediated steroidogenic gene expression.

Adrenal Cortex↗
PubMed2000

[Immunohistochemical study of mast cells in allergic rhinitis: an indicator for assessing the therapeutic effect of chemosurgery using trichloroacetic acid].

An immunohistochemical study was conducted on the degree of tryptase-positive, chymase-negative mast cells (MCT) and tryptase-positive, chymase-positive mast cells (MCTC) infiltration in the inferior turbinates of 15 patients with perennial allergic rhinitis who underwent septal reconstruction and bilateral inferior turbinectomy 85 +/- 21 days after unilateral chemosurgical treatment using trichloroacetic acid (TCA). In samples without TCA treatment, many MCTs were observed in the mucosal epithelium near the basement membrane, especially in the area where many goblet cells were found, and some MCTs were found around the glands and vessels in the subepithelial layer. Most MCTCs were found in the subepithelial layer, and some in the epithelial layer. On the TCA-treated side, part of the epithelium disappeared, becoming squamatized epithelium in which MCTs were scarcely observed. Statistically, the number of mast cell on the side of TCA treatment was significantly less than on the non-treated side in the epithelial layer. In treated subepithelium layer, both MCTs and MCTCs were significantly fewer than on the non-treated side. These pathological findings suggest that TCA surgery has clinical potential to improve allergic rhinitis symptoms.

Adult↗
PubMed2000

WF14865A and B, new cathepsins B and L inhibitors produced by Aphanoascus fulvescens. I. Taxonomy, production, purification and biological properties.

WF14865A and B, novel cathepsins B and L inhibitors, were produced and isolated separately from the culture mycelium of a fungal strain Aphanoascus fulvescens No. 14865. Spectroscopic analysis revealed that both WF14865A and B were composed of trans-epoxysuccinyl moieties, 1-H-imidazole-2-ylamine, and isoleucine or leucine. These compounds inhibited human cathepsins B and L with IC50 values in the range of 8.4 approximately 72nM in vitro. Though their in vitro properties were typical as trans-epoxysuccinyl type inhibitors, they exerted strong bone resorption inhibitory effects in low-calcium-diet-fed mouse model at 3.2 approximately 10 mg/kg.

Animals↗
PubMed2000

[Retrospective study of acute myelogenous leukemia in 83 elderly patients: clinical and biological characteristics].

In order to characterize clinical and biological characteristics of elderly patients with acute myelogenous leukemia (AML), we retrospectively analysed 83 elderly patients aged 60 years or more and, as a control, 114 younger patients aged 15 to 59 years who were admitted to our hospital between August 1984 and January 1998. There was a significantly higher incidence of preceding myelodysplastic syndromes in the elderly patients. They also had a significantly higher incidence of unfavorable cytogenetic abnormalities (loss or partial deletion of chromosome 5 or 7) and a significantly lower incidence of favorable cytogenetic abnormalities, such as t(15:17), t(8:21), or inv(16). With regard to FAB subtypes in de novo AML, the incidence of M3 subtype was significantly lower in the elderly group. Myeloperoxidase positivity of AML cells in the elderly group was lower than that in the younger group. Laboratory data at presentation disclosed a lower peripheral leukemic cell count, a higher fibrinogen level, a lower serum protein level, and a higher serum creatinine level in the elderly group. They also had poorer performance status and more frequent concomitant diseases at presentation, including liver diseases, heart diseases, or documented infections. It was concluded that elderly AML patients 60 years or older had a higher incidence of poor prognostic factors compared to younger patients.

Adolescent↗
PubMed2000

[Retrospective study of acute myelogenous leukemia in elderly patients: treatment and outcome of 83 consecutive patients].

We retrospectively analyzed treatments and outcomes for 83 acute myelogenous leukemia (AML) patients aged 60 years or more (median age 71) admitted to our hospital between August 1984 and January 1998. Complete remission was achieved in 36% of 78 patients who received anti-leukemic therapy, and median overall survival was 227 days. In addition to abnormal karyotypes involving chromosome 5 or 7, administration of less than 120 mg/m2/course of daunorubicin (DNR) during the initial treatment phase was an unfavorable prognostic factor for both CR and survival. Only 41% of all patients received 120 mg/m2/course of DNR or more, and had a significantly higher CR rate (56%) and longer survival, with a median of 389 days. It was suggested that intensive chemotherapy was effective for selected elderly AML patients who were relatively younger and had good performance status, although the number of such patients was limited in our study.

Age Factors↗
PubMed2000

[A case of mixed connective tissue disease with lupus-like manifestations of the central nervous system, successfully treated with cyclophosphamide combined with prednisolone].

A 29-year-old woman experienced Raynaud's phenomenon, swelling of her fingers, eruptions on her face, and muscle weakness in 1990. She was diagnosed as having mixed connective tissue disease (MCTD) and was treated with prednisolone (PSL) for 3 years. Most of her complaints disappeared after the treatment. In March 1997, she experienced fever, erythema, and lymphadenopathy. Although she was treated with PSL (20 mg/day) again, muscle weakness, mental disturbance, and recto-urinary disturbance appeared. When she was re-admitted to our hospital, increased levels of muscle-derived enzymes and positivity of anti-RNP antibody were found. High signal areas in her cerebrum were shown by magnetic resonance imaging, and slow and spike pattern was shown by electroencephalography. Hypoperfusion of the cerebral blood flow was suggested on single photon emission computed tomography. The number of mononuclear cells, amount of protein and level of interleukin-6 were found to be elevated in her cerebrospinal fluid (CSF). Her neurological manifestations were diagnosed as being due to MCTD, and showed characteristics similar to those of systemic lupus erythematosus. She was treated with PSL (60 mg/day) followed by steroid pulse therapy. Because the response to this treatment was partial, oral administration of cyclophosphamide (CPM) (100 mg/day) was added. Muscle weakness and neurological abnormalities as well as abnormal laboratory findings gradually improved over the following two months. We conclude that the treatment with CPM combined with PSL may be useful, when neurological manifestations of MCTD are serious and resistant to conventional therapy.

Adult↗
PubMed2000

[HPLC-separation of racemic cyclohexane-1,2-diamine platinum(II) dimyristates on chiral stationary phases] .

In this paper, the stereochemical resolution of racemic cyclohexane-1,2-diamine platinum(II) dimyristates on chiral stationary phases (CSP) is described. These CSP are Pirkle phases chiral column (Sumichiral OA-2500, 3100, 3200, 3300, 4000, 4100). Among them, the Sumichiral OA-2500 column gave the best results. The effects of the temperature and mobile phase composition as well as the hydrophobicity of the analytes on the chromatographic separation are described.

Chromatography, High Pressure Liquid↗
PubMed2000

[Pulmonary Nocardia otitidiscaviarum infection in an immunocompetent host].

A rare case of pulmonary Nocardia otitidiscaviarum (N. otitidiscaviarum) was encountered in an immunocompetent host. A 74-year-old man was admitted to our hospital with a high fever and a productive cough. His chest radiograph and CT scan revealed infiltrative shadows in the right middle and lower lung fields. Although several antibiotics (third-generation cephalosporin, minocycline, imipenem) were administered, the fever and cough persisted, and C-reactive protein remained elevated. Repeated sputum cultures showed normal flora, so a transbronchial lung biopsy and bronchoalveolar lavage (BAL) were performed bronchoscopically at the right S5. The BAL fluid contained acid-fast, branching filamentous structures. The microorganism was identified as N. otitidiscaviarum by the Research Center for Pathogenic Fungi and Microbial Toxicoses (Chiba University). Trimethoprim-sulfamethoxazole was therefore administered, but the fever continued to rise daily, and C-reactive protein remained elevated. This isolated N. otitidiscaviarum showed resistance to multiple antimicrobial agents in vitro when examined by the disk diffusion method, and so, on the basis of the antibiogram, the patient was treated with clarithromycin (oral, 600 mg/day) plus amikacin (400 mg/day), which proved successful. Testing for pulmonary nocardiosis should be added to the differential diagnosis procedures for refractory pneumonia as an opportunistic infection and for community-acquired pneumonia.

Aged↗
PubMed2000

[Human heparanase: roles in invasion and metastasis of cancer].

Heparanase, which is an extracellular matrix degradative enzyme, degrades heparan sulfate and heparan sulfate proteoglycans, which are chief components of extracellular matrix and vascular basement membrane. The gene structure of this enzyme was recently determined. The biological functions of this enzyme in vivo were as follows: 1) this enzyme accelerates cancer cell invasion and metastasis though the degradation of vascular basement membrane and extracellular matrix by cancer cells; 2) this enzyme releases and activates heparin-binding growth factors such as bFGF and VEGF from heparan sulfate proteoglycans, and induces angiogenesis; 3) the degradative products of heparan sulfate proteoglycans by this enzyme suppress the biological function of activated T-lymphocytes. Therefore, heparanase is thought to be a favorable molecule for acceleration of cancer invasion and metastasis. The expression of heparanase is strongly correlated with the metastasis of melanoma and fibrosarcoma. Thus, heparanase may play important roles in invasion and metastasis of cancer.

Animals↗
PubMed2000

Biological hydrogen potential of materials characteristic of the organic fraction of municipal solid wastes.

The purpose of this study is to investigate the biological hydrogen production potential of individual organic fraction of municipal solid wastes (OFMSW) by batch experiments. Seven varieties of typical organic solid wastes including rice, cabbage, carrot, egg, lean meat, fat and chicken skin were selected to estimate the hydrogen production potential. Among the OFMSW, carbohydrate produced the most hydrogen through biological hydrogen fermentation compared with proteins or lipids. Subsequently, the biological hydrogen production potentials of some individual carbohydrate were measured: cabbage, 26.3-61.7 mL/g-VS; carrot, 44.9-70.7 mL/g-VS; and rice, 19.3-96.0 mL/g-VS. The hydrogen percentages of the total biogas produced from cabbage, carrot and rice were 33.9-55.1%, 27.7-46.8% and 44.0-45.6%, respectively.

Bacteria, Anaerobic↗