Biomedical subjects

M Takasaki

Publications and source records attributed to M Takasaki.

At least 37 records · Page 2Linked to original sources

PubMed2001

Cooperative effects of exercise training and genistein administration on bone mass in ovariectomized mice.

We reported that genistein, a soybean isoflavone, prevents bone loss caused by estrogen deficiency, without undesirable effects on the uterus. In this study, we examined cooperative effects of genistein administration and running exercise on bone mass in ovariectomized (OVX) mice. Female mice aged 7 weeks were either sham-operated or OVX and divided into six groups: (1) sham; (2) OVX; (3) OVX, treated with genistein at a submaximal dose (0.4 mg/day) subcutaneously (G); (4) OVX, exercised on a treadmill daily for 30 minutes/day at 12 m/minute on a 10 degree uphill slope (Ex); (5) OVX, given genistein and exercised (ExG); and (6) OVX, treated with 17beta-estradiol (0.03 microg/day) in the same manner as genistein (E2). Four weeks after intervention, bone mass was estimated by dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT). Bone mineral density (BMD) of the whole femur measured by DXA was higher in both the G and the Ex groups than in the OVX group. Furthermore, BMD in the ExG group was significantly higher than that in the groups receiving either intervention alone. Bone area in distal region of the femur was significantly higher in Ex and ExG groups as compared with those in the OVX and G groups. pQCT analysis showed that the cross-sectional areas (CSAs) and periosteum perimeter at midshaft of the femur did not differ in the sham and OVX groups but were significantly higher in Ex and ExG groups. Histomorphometric analysis showed that bone formation rate/bone surface (BFR/BS) was significantly higher in both Ex and ExG groups as compared with that in non-exercised groups. The bone volume (BV/TV) in the distal femoral cancellous bone was lower in the OVX than that in the sham group, and it was restored completely in the ExG group, as in the E2 group. Thickness of the trabecular bone (Tb.Th) was higher in Ex and ExG groups than that in the OVX and G groups. These results indicate that the combined intervention of moderate exercise and the submaximal dose of genistein administration show a cooperative effect in preventing bone loss in OVX mice.

Animals↗

PubMed2001

[Noninvasive positive-pressure ventilation in an elderly woman with acute respiratory failure caused by influenza a virus pneumonia].

A 79-year-old woman was admitted on January 18, 2000, with a lumbar compression fracture. Two days after admission, a chest X-ray film showed reticular infiltrates in the right lung field. She was diagnosed as having pneumonia and was treated with antibiotics. Despite this therapy, her symptoms did not improve and the infiltrates diffusely extended to involve both lungs on chest X-ray films. She was placed on noninvasive positive pressure ventilation (NIPPV) for progressive respiratory failure at 5 days after admission in order to avoid endotracheal intubation. Her hypoxemia was immediately improved by oronasal bilevel positive airway pressure ventilation (BiPAP) and chest X-ray films revealed improvement of the reticular infiltrates. Measurement of viral antibody titers showed that the cause of acute respiratory failure was influenza A virus pneumonia. In conclusion, NIPPV may reduce the need for intubation of elderly patients with acute respiratory failure, as well as chronic obstructive pulmonary disease (COPD) patients.

Acute Disease↗

PubMed2001

[Present status and problems in medical care for demented patients using public counselling facilities].

To clarify the present status and problems in medical care for the elderly with dementia, 103 cases were studied according to the descriptive records obtained at a public counselling facility for dementia, based on interviews with patients' families. Their records were analysed based on their background, severity of dementia (clinical dementia rating: CDR), and counselling content. There were 75 demented patients with a CDR score of 1 or more, and 50 of them were women aged 54 to 90, while the remaining 25 men were aged 55 to 88. The consultation content was clustered into 5 codes: code 1, evaluation of dementia and/or dementia-related symptoms including psychiatric symptoms and behavioral disturbance; code 2, methods to manage patients; code 3, methods to take a patient to a medical institution; code 4, questions regarding medical treatment and drugs prescribed at present; code 5, information on the welfare resources provided. In most of the 75 patients, the degree of dementia deteriorated insidiously without any physical symptoms. The key person and/or caregiver was usually an elderly spouse, and the family noticed dementia only after cognitive impairment progressed with or without troublesome symptoms. Hallucination was a common troublesome symptom. Concerning consultation content, codes 1, 2, and 3 were common, while 13 cases had dissatisfaction with their medical treatment. Therefore, it was necessary to explain the significance of early diagnosis of dementia to families and their caregivers. There were also many families who felt strain and wondered about what hospital or department to take the patient to. In addition, it seemed that explanation on the clinical course and adverse drug reactions, advice for the correspondence with psychiatric symptoms and abnormal behaviour, and information services concerning utilization of social resources was not yet sufficient.

Aged↗

PubMed2001

[An elderly case of lung cancer presenting with symptoms of orbital metastasis].

An 88-year-old woman was first referred to an eye clinic in mid-May 2000 because of limitation of ocular movement. A right orbital tumor was recognized on orbital CT scans and she was referred to our hospital. A chest X-ray film showed an abnormal mass in the right middle lung field, so she was admitted for further investigations. Adenocarcinoma was diagnosed by transbronchial lung biopsy. The right orbital tumor was thought to be a metastasis from the lung cancer. She received radiation therapy for the metastatic orbital tumor. However, two months after the onset of symptoms, she died due to progressive systemic metastasis. In summary, we report an elderly lung cancer patient whose initial symptoms were related to orbital metastasis.

Adenocarcinoma↗

PubMed2001

[Findings of bedside swallowing assessment and brain computerized tomography in patients with chronic cerebral infarction, and their outcome].

To estimate the usefulness of the bedside swallowing assessment proposed by Smithard et al and neuroimaging findings characteristic for dysphagia, we studied the outcome of 102 patients with chronic cerebral infarction after assessment of swallowing by this test with brain computerized tomography (CT). All patients had a variety of motor disturbance and were admitted on a long-term medicare basis. They were divided into two groups according to the findings: the positive group (n = 33), who showed any of the listed types of difficulty in swallowing water, and the negative group (n = 69). Followed up to 2.2 years, their outcomes were studied. CT findings were studied on type of infarction, number and laterality of infarction, grade of periventricular lucency (PVL), presence of ventricular dilatation (VD), and severity of cortical atrophy (CA). The mean age was 76.4 years at registration and 61 were men. The frequency of severe dementia and disturbed ADL were significantly higher in the positive group. Eighteen patients died during the observation period and 15 of those were in the positive group, indicating higher annual death rate (29.9% vs 2.2% in the negative group). All of the 15 patients in the positive group died of pneumonia. CT findings showed high incidence of multiple infarction, bilateral hemispheric lesion, severe PVL, VD, and severe CA in the positive group. These findings indicated that this evaluation method was useful in screening swallow function for patients with cerebral infarction in the chronic phase. Furthermore, CT findings suggested that severe white matter lesion, VD, and severe CA as well as multiple infarction seen in bilateral hemisphere was related to dysphagia, probably due to multiple factors involving pyramidal- and extrapyramidal-tracts with higher brain function.

Adult↗

PubMed2001

Effect of ethyl icosapentaenoate (EPA) on the concentration of tumor necrosis factor (TNF) and interleukin-1 (IL-1) in the carotid artery of cuff-sheathed rabbit models.

To evaluate the effect of ethyl icosapentaenoate (EPA) on the metabolism of tumor necrosis factor alpha (TNFalpha) and interleukin-1beta (IL-1beta), the concentrations of these cytokines in the carotids of rabbits sheathed in a cuff were studied. Japanese white rabbits were divided into two groups; the EPA group, in which 600 mg/kg/day EPA was administered forcibly p.o. for 1 week before cuff treatment, and the control group. Carotid artery samples were obtained just before, 3 days and 7 days after cuff treatment, and TNFalpha and IL-1beta were determined separately with the Western blot analysis method. In the control group, there were 43.5 (+/- 3.0) pg/microg protein of TNFalpha and 53.5 (+/- 4.8) pg/microg protein of IL-1beta just before cuff treatment. Compared to the control group, these concentrations of the EPA group were both significantly low. Three days after cuff treatment, TNFalpha of the EPA group was still significantly low, while IL-1beta showed no difference. There was no significant difference between the two groups 7 days after cuff treatment. These findings suggested that EPA could influence TNFalpha and IL-1beta metabolism in the arterial wall even at baseline. Furthermore, EPA suppressed TNFalpha and IL-1beta production in the early phase of intimal thickening, indicating a mechanism inhibiting the activation of smooth muscle cells such as their proliferation and migration, induced by the cuff-sheath method.

Animals↗

PubMed2001

Up-regulation of cell surface sodium channels by cyclosporin A, FK506, and rapamycin in adrenal chromaffin cells.

Treatment of cultured bovine adrenal chromaffin cells with cyclosporin A (CsA) increased cell surface [(3)H]saxitoxin ([(3)H]STX) binding by 56% in a time (t(1/2) = 15.2 h)- and concentration (EC(50) = 2.9 microM)-dependent manner but did not change the K(d) value. In CsA-treated cells, veratridine-induced (22)Na(+) influx was augmented with no change in the EC(50) of veratridine; also, alpha- and beta-scorpion venom and Ptychodiscus brevis toxin-3 enhanced veratridine-induced (22)Na(+) influx in a more than additive manner, as in nontreated cells. CsA treatment for 1 to 24 h inhibited calcineurin activity, measured by the in vitro assay, with the IC(50) of 0.6 microM but did not alter cellular level of calcineurin. FK506 or rapamycin elevated [(3)H]STX binding by 36 or 25%, whereas GPI-1046, an immunophilin ligand incapable to inhibit calcineurin, or okadaic acid, an inhibitor of protein phosphatases 1 and 2A, had no increasing effect. The rise of [(3)H]STX binding by CsA was attenuated by the coincident treatment with brefeldin A (BFA), an inhibitor of vesicular exit from the trans-Golgi network. The internalization rate of cell surface Na(+) channels, as determined in the presence of BFA, was decreased in CsA (but not rapamycin)-treated cells (t(1/2) = 20.3 h), compared with nontreated cells (t(1/2) = 13.7 h). CsA treatment, however, did not elevate cellular levels of Na(+) channel alpha-subunit and Na(+) channel alpha- and beta(1)-subunit mRNAs. In CsA-treated cells, veratridine-induced (45)Ca(2+) influx via voltage-dependent Ca(2+) channels and catecholamine secretion were enhanced, whereas high K(+)-induced (45)Ca(+) influx was not. Thus, the inhibition of calcineurin or rapamycin-binding protein causes up-regulation of cell surface functional Na(+) channels via modulating externalization and internalization of Na(+) channels, thus enhancing Ca(2+) channel gating and catecholamine secretion.

Adrenal Glands↗

PubMed2001

[Depressive effect of dibucaine and bupivacaine on the growth of axons from cultured neuron of Lymnaea stagnalis].

The depressive effect of dibucaine (n = 8) was compared with that of bupivacaine (n = 9) using identified cultured neurons (A cluster) of Lymnaea stagnalis. Cultured interneurons exhibit extensive neurite outgrowth within 14-20 hours when placed in brain conditioned media. The changes of cultured neuron were recorded using a color video camera directly connected to an inverted microscope and the images were stored on digital video tape. Local anesthetics were added to the culture dish, with final concentrations of 1 x 10(-6) M-8 x 10(-4) M of dibucaine and 1 x 10(-5) M-8 X 10(-3) M of bupivacaine. We examined the damage of growth cone before and 30 minute after local anesthetics administration. Histologic damage were scored from moderate to severe compared to the control before dibucaine or bupivacaine administration. Dibucaine or bupivacaine damaged the growth cone moderately in the concentration of 1 x 10(-5) M or 4 x 10(-4) M, respectively. While dibucaine or bupivacaine damaged it severely in the concentration of 8 x 10(-5) M or 2 x 10(-3) M, respectively. These results suggest that bupivacaine is safer than dibucaine with the concentration we use in clinical practice.

Animals↗

PubMed2001

Donepezil hydrochloride preserves regional cerebral blood flow in patients with Alzheimer's disease.

UNLABELLED: The aim of this SPECT study was to investigate the effects of donepezil on regional cerebral blood flow (rCBF) in patients with mild to moderate Alzheimer's disease (AD) using statistical parametric mapping. METHODS: rCBF was noninvasively measured using (99m)Tc-ethyl cysteinate dimer in 35 AD patients with a Mini-Mental State Examination score > 16 on initial evaluation. Baseline and follow-up SPECT studies with a mean interval of 12 mo were performed on these patients. We used the adjusted rCBF images in the relative flow distribution (normalization of global cerebral blood flow for each patient to 50 mL/100 g/min with proportional scaling) to compare these groups through statistical parametric mapping. RESULTS: In the follow-up study, the adjusted rCBF was significantly preserved in the right and left anterior cingulate gyri, right middle temporal gyrus, right inferior parietal lobules, and prefrontal cortex of donepezil-treated AD patients, compared with placebo-treated AD patients. CONCLUSION: Treatment with donepezil for 1 y appears to reduce the decline in rCBF, suggesting preservation of functional brain activity.

Aged↗

PubMed2001

[Diagnosis of Alzheimer's disease using brain SPECT with three-dimensional stereotactic surface projections].

We compared the diagnostic usefulness of three-dimensional stereotactic surface projection (3D-SSP) with that of standard transaxial images in brain SPECT in patients with Alzheimer's disease (AD). The subjects consisted of 69 patients with AD and 60 patients with non-AD, including vascular dementia, Parkinson's disease with dementia, frontotemporal dementia, other dementing diseases and neuropsychiatric diseases. Standard transaxial section and 3D-SSP SPECT images with N-isopropyl-p-[123I] iodoamphetamine were blindly interpreted by three examiners and were classified into the following three patterns: typical AD, atypical AD, and not indicative AD patterns. The 3D-SSP images demonstrated reductions of cerebral blood flow in the parieto-temporal association cortex and posterior cingulate gyrus more clearly and easily than the standard transaxial images. The diagnostic sensitivity and specificity were 93% and 85% with 3D-SSP and 83% and 82% with standard transaxial section respectively. 3D-SSP was especially useful for early or atypical AD which showed no characteristic perfusion abnormalities on standard transaxial images. These results suggest that SPECT with 3D-SSP provides an sensitive as well as accurate tool for the diagnosis of AD.

Aged↗

PubMed2000

Inhibition of epstein-barr virus early antigen activation promoted by 12-O-tetradecanoylphorbol-13-acetate by the non-steroidal anti-inflammatory drugs.

As part of our screening program for cancer inhibitory agents effective specifically in the promotion stage of cancer development, we have evaluated the possible inhibitory effects of 36 non-steroidal anti-inflammatory drugs (NSAIDs) on the Epstein-Barr virus early antigen (EBV-EA) activation which was induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in Raji cells. All the drugs were observed to inhibit the EBV-EA activation at low doses with low toxicity. The two most active anti-tumor promoting agents were the arylacetic acid derivatives, etodolac and sulindac. We also report for the first time the activities of 14 new NSAIDs belonging to different classes as potential cancer chemopreventive agents. A structure-activity relationship study showed that among the salicylic acid derivative tested, the oxidation of the thiol group to dithiol derivatives results in the reduction of the activity. Introduction of amino group on the salicylic acid molecules also results in the reduction of activity in the EBV-EA assay. The results are of great interest in the development of NSAIDs as cancer chemopreventive agents, which halt cancer progression in multistage carcinogenesis, where successive activities are required to evolve into fully-fledged and metastatic cancer.

Acetates↗

PubMed2000

Post-translational reduction of cell surface expression of insulin receptors by cyclosporin A, FK506 and rapamycin in bovine adrenal chromaffin cells.

Long-term (>/=3 h) treatment of cultured bovine adrenal chromaffin cells with cyclosporin A (CsA) decreased cell surface (125)I-insulin binding by 62% in a concentration (IC(50)=18 microM)- and time (t(1/2)=16 h)-dependent manner, but did not change the K(d) value. FK506 (1 microM) or rapamycin (3 microM) treatment reduced (125)I-insulin binding. Western blot analysis showed that CsA treatment decreased insulin receptor (IR) beta-subunit level (t(1/2)=15 h) in membrane fraction, but did not alter total cellular levels of IR precursor and IR beta-subunit. Internalization rate of cell surface IR measured by using brefeldin A, an inhibitor of vesicular exit from the trans-Golgi network, was comparable between non-treated and CsA-treated cells. Thus, CsA, FK506 and rapamycin inhibit peptidyl prolyl cis-trans isomerase activities of cyclophilin and FK506-binding protein, and down-regulate IR presumably by reducing cell surface externalization of IR.

Animals↗

PubMed2000

Anti-tumor-promoting activity of lignans from the aerial part of Saussurea medusa.

In the course of our continuing search for novel cancer chemopreventive agents from natural sources, several kinds of Compositae plants were screened. Consequently, the lignans, arctiin (ARC) and arctigenin (ARC-G), were obtained from the aerial part of Saussurea medusaas active constituents. These compounds exhibited the remarkable anti-tumor-promoting effect on two-stage carcinogenesis test of mouse skin tumors induced by 7, 12-dimethylbenz[a]anthracene as an initiator and 12-O-tetradecanoyl phorbol-13-acetate as a promoter by both topical application and oral administration. Furthermore, ARC-G exhibited potent anti-tumor-promoting activity on two-stage carcinogenesis test of mouse pulmonary tumors induced by 4-nitroquinoline-N-oxide as an initiator and glycerol as a promoter.

4-Nitroquinoline-1-oxide↗

PubMed2000

Cancer chemopreventive activity of an iridoid glycoside, 8-acetylharpagide, from Ajuga decumbens.

In the course of our continuing search for novel cancer chemopreventive agents from natural sources, several kinds of Labiatae plants were screened. Consequently, the iridoid glycoside derivative, 8-acetylharpagide (8-AcHarp), was obtained from the flowering whole plant of Ajuga decumbens as an active constituent. This glycoside exhibited the remarkable inhibitory effect on two-stage carcinogenesis test of mouse skin tumors induced by nitric oxide (NO) donor, (+/-)-(E)-methyl-2-[(E)-hydroxyimino]-5-nitro-6-methoxy-3-hexen eamide (NOR 1) as an initiator and 12-O-tetradecanoylphorbol-13-acetate (TPA) as a promoter. Further, 8-AcHarp exhibited potent anti-tumor-promoting activity on two-stage carcinogenesis test of mouse hepatic tumor using N-nitrosodiethylamine (DEN) as an initiator and phenobarbital (PB) as a promoter.

Animals↗

PubMed2000

Cancer chemopreventive activity of euglobal-G1 from leaves of Eucalyptus grandis.

In the course of our continuing search for novel cancer chemopreventive agents from natural sources, several kinds of Eucalyptus plants were screened. Consequently, the phlorogrucinol-monoterpene derivative, euglobal-G1 (EG-1), was obtained from the leaves of Eucalyptus grandis as an active constituent. EG-1 exhibited the remarkable inhibitory effect on two-stage carcinogenesis test of mouse skin tumors induced by 7, 12-dimethylbenz[a]anthracene (DMBA) as an initiator and fumonisin-B1, which has been known as one of mycotoxins produced by Fusarium monifliforme, as a promoter. Further, EG-1 exhibited potent anti-tumor-promoting activity on two-stage carcinogenesis test of mouse pulmonary tumor using 4-nitroquinoline-N-oxide (4-NQO) as an initiator and glycerol as a promoter.

4-Nitroquinoline-1-oxide↗

PubMed2000

Ephedrine, dopamine, or dobutamine to treat hypotension with propofol during epidural anesthesia.

PURPOSE: To compare the efficacy of ephedrine, dopamine and dobutamine for circulatory support during thoracic epidural anesthesia after anesthetic induction with propofol. METHODS: Forty patients undergoing lobectomy or mastectomy were divided into four groups of 10: a control group received no vasopressor; an ephedrine group received 5 mg ephedrine when the mean arterial pressure (MAP), measured every 2.5 min, decreased by 10% from baseline; dopamine and dobutamine groups received 5 microg x kg(-1) x min(-1) dopamine or 3 microg x kg(-1) x min(-1) dobutamine from five minutes after epidural injection of local anesthetic to the end of tracheal intubation. Anesthesia was induced with 2 mg x kg(-1) propofol. The MAP and heart rate (HR) were measured at baseline, 20 min after epidural injection, three minutes after propofol, and one minute after tracheal intubation. RESULTS: In the control group, MAP and HR decreased from 86+/-9 mmHg, 74+/-8 bpm to 62+/-9 mm Hg; P<0.0001, 60+/-8 bpm; P = 0.0003 after propofol. After tracheal intubation, MAP was restored to (81+/-13 mmHg, 70+/-13 bpm). In the ephedrine, dopamine, and dobutamine groups, MAP and HR remained unchanged during epidural anesthesia and propofol induction. However, after tracheal intubation, MAP and HR increased in the ephedrine (104+/-11 mm Hg; P = 0.004, 87+/-11 bpm; P<0.0001) and dobutamine (117+/-13 mm Hg; P = 0.0005, 100+/-11 bpm; P<0.0001) groups, but not in the dopamine group compared with baseline. CONCLUSION: Dopamine is preferable to ephedrine and dobutamine in providing hemodynamic stability during propofol induction and tracheal intubation following epidural anesthesia.

Adrenergic Agents↗

PubMed2000

Flavonoid and benzophenone glycosides from Coleogyne ramosissima.

A benzophenone glucoside and two flavonol glycosides were isolated together with 27 known polyphenols from the aerial parts of Coleogyne ramosissima, and their structures were elucidated by spectroscopic and chemical methods as iriflophenone 2-O-beta-glucopyranoside, isorhamnetin 3-O-2G-rhamnopyranosylrutinoside-7-O-alpha-rhamnopyranoside and limocitrin 3-O-rutinoside-7-O-beta-glucopyranoside, respectively.

Carbohydrate Conformation↗

PubMed2000

Optimum contact conditions for miniaturized surface acoustic wave linear motor

This paper reports the successful operation of a 70 MHz driving surface acoustic wave (SAW) linear motor with a miniaturized stator transducer. This paper also deals with an investigation into an optimized slider design for the miniaturized SAW linear motor. The performance of three silicon type sliders, with different projection size, was compared. Output forces of the three sliders were measured with change of pre-load. It was found that the slider with smaller projection tended to produce greater output force.

Journal Article↗