Biomedical subjects

T Miyamoto

Publications and source records attributed to T Miyamoto.

At least 109 records · Page 6Linked to original sources

PubMed2001

Three new acylated triterpene saponins from Acanthophyllum squarrosum.

Three new triterpenoid saponins, 1-3, were isolated from the roots of Acanthophyllum squarrosum. Their structures were established mainly by 2D NMR techniques as 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucuronopyranosyl-gypsogenin-28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-beta-D-xylopyranosyl-(1-->4)-3-O-acetyl-alpha-L-rhamnopyranosyl-(1-->2)-3,4-di-O-acetyl-beta-D-fucopyranoside (1), 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucuronopyranosyl-gypsogenin-28-O-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-[5-O-acetyl-alpha-L-arabinofuranosyl-(1-->3)]-4-O-acetyl-beta-D-fucopyranoside (2), and 3-O-beta-D-glucopyranosyl-quillaic acid-28-O-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->6)]-beta-D-glucopyranoside (3).

Carbohydrate Sequence↗

PubMed2001

Junceosides A-C, new triterpene saponins from Arenaria juncea.

Three novel triterpenoid saponins, junceosides A (1), B (2), and C (3), together with two known saponins have been isolated from the roots of Arenaria juncea. Their structures were elucidated using a combination of homo- and heteronuclear 2D NMR techniques (COSY, TOCSY, NOESY, HSQC, and HMBC) and by FABMS. The new compounds were characterized as 3-O-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-galactopyranosyl-(1-->3)]-beta-D-glucuronopyranosylgypsogenin-28-O-beta-D-glucopyranosyl(1-->3)-[beta-D-xylopyranosyl-(1-->4)]-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranoside (1), 3-O-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-galactopyranosyl-(1-->3)]-beta-D-glucuronopyranosylgypsogenin-28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranoside (2), and 3-O-beta-D-xylopyranosyl-(1-->3)-[beta-D-galactopyranosyl-(1-->2)]-beta-D-glucuronopyranosylgypsogenin-28-O-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranoside (3).

Caryophyllaceae↗

PubMed2001

A comparison of middle latency auditory-evoked response in obstructive sleep apnea syndrome before and after treatment.

The ascending reticular activating system seems to be affected by nocturnal hypoxia in obstructive sleep apnea syndrome (OSAS) patients so that their vigilance level is decreased. To evaluate the change in vigilance level in OSAS patients, polysomnography, the Epworth Sleepiness Scale and middle latency auditory-evoked responses (MLR) were measured before and after treatment in seven men with OSAS (mean age 45.4 +/- 12.9 years, mean body mass index 33.3 +/- 7.6 kg/m2). After treatment there was significant improvement of nocturnal hypoxia in OSAS. Peak amplitude of P1 in MLR increased after treatment. There was also improvement of the electrical field distribution of MLR on the scalp. The results suggest that the decreased vigilance level in OSAS patients is reversible with treatment.

Arousal↗

PubMed2001

Amyotrophic lateral sclerosis associated with insomnia and the aggravation of sleep-disordered breathing.

A case of amyotrophic lateral sclerosis (ALS) diagnosed by sleep-disordered breathing is described. The patient's chief complaints were insomnia and nocturnal dyspnea after taking a hypnotic drug. On examination, he showed restrictive ventilatory impairment, alveolar hypoventilation and hypoxia. Polysomnographic examination revealed marked hypoxia during REM sleep periods, decreased duration of REM sleep periods, and increased sleep disruption. Amyotrophic lateral sclerosis was diagnosed by the neurological finding of paraspinal muscle weakness and neurogenic changes revealed by needle electromyography and muscle biopsy. The daytime and nocturnal respiratory insufficiency improved after nasal bilevel positive airway pressure therapy. Amyotrophic lateral sclerosis should be suspected as a cause of insomnia and nocturnal dyspnea.

Amyotrophic Lateral Sclerosis↗

PubMed2001

Parasomnia as an occasion for the diagnosis of Parkinson's disease.

We report a case of Parkinson's disease (PD) diagnosed by REM sleep behavior disorder (RBD). The patient was a 68-year-old man. On admission, rigidity in the left upper and lower extremities, bradykinesia, and gait disturbance were noted. In addition, polysomnography revealed REM sleep without atonia (RWA), and a diagnosis of untreated PD associated with RBD was made. Polysomnographic data showed that REM density decreased and RWA tended to increase after administration of a combination of L-DOPA and DCI (L-DOPA/DCI). Thus, we considered that the pathophysiological mechanism of RBD in this case was based not only on the dysfunction of the brainstem mechanism of RWA, but also on the impairment of dopaminergic neuron.

Aged↗

PubMed2001

Effects of bright light exposure on heart rate variability during sleep in young women.

To investigate the effects of evening bright light on the autonomic nervous system, heart rate variability (HRV) during sleep was analyzed in dim light (DL) and bright light (BL) conditions. We recorded polysomnography in nine healthy young women aged 20-21 years. Time series of % delta power was calculated in the 0.49-2.20 Hz band. Heart rate variability was analyzed from a 10-min segment of slow wave sleep. The low- to high-frequency ratio and the low-frequency component decreased significantly in the BL conditions compared with the DL conditions. However, the power of the high-frequency component did not change in the two conditions. These results indicate that evening BL affects the autonomic nervous system during slow wave sleep.

Adult↗

PubMed2001

Efficacy of budesonide Turbuhaler compared with that of beclomethasone dipropionate pMDI in Japanese patients with moderately persistent asthma.

OBJECTIVE: The aim of the study was to compare the efficacy and safety of budesonide Turbuhaler with that of beclomethasone dipropionate (BDP) pMDI. METHODOLOGY: Three hundred and fifty adult asthma patients (mean age 52.7 years, mean baseline morning peak expiratory flow (PEF) 294 L/min (< 80% predicted normal)), taking BDP via pressurized metered-dose inhaler (pMDI), 400 microg daily for at least 2 months, were randomized in an open 6 week study to receive daily doses of either budesonide 100 microg or 400 microg twice daily via Turbuhaler or continued treatment with BDP, 100 microg four times daily. The primary efficacy variable was the mean change in morning PEF from baseline to the end of treatment. Outcome was also assessed using symptom scores and investigators' assessments employed in Japanese clinical trials. RESULTS: At the end of the 6 week treatment period, mean morning PEF improved significantly from baseline in both budesonide groups, 16 L/min and 33 L/min in the 200 microg and 800 microg groups, respectively, but not in the BDP group, 5 L/min. There was no significant difference between 200 microg budesonide and 400 microg BDP treatment in the effect on PEF (P = 0.29), but 800 microg budesonide was significantly superior to BDP (P < 0.001). Final assessment of improvement and usefulness ratings showed that both budesonide treatments were significantly superior to BDP (P < 0.001). All treatments were well tolerated. CONCLUSION: Budesonide Turbuhaler (200 microg) was as effective as 400 microg BDP pMDI. The efficacy of budesonide was improved significantly by increasing the dosage to 800 microg daily. The study design shows the importance of including a higher dose treatment group when comparing two formulations of inhaled corticosteroids in order to determine whether the treatments to be compared are on the steep part of the dose-response curve. Without that information, comparative studies are usually inconclusive.

Anti-Inflammatory Agents↗

PubMed2001

Evaluation of three-dimensional glenoid structure using MRI.

The tilting angle and the shape of the glenoid cavity are considered to relate closely to shoulder stability. They are also important when planning arthroplasty and developing new designs. This study examines the glenoid cavity using 3-dimensional MRI. Forty volunteers (20 men, 20 women; average age 21.4; range 18-35 y) were enrolled in the study. The tilting angles of the glenoid bone were measured in 5 consecutive axial planes perpendicular to the glenoidal long axis. Cross sections were divided into 3 types (concave, flat, convex) according to the shape on each plane. The average tilting angles for the 5 planes from the bottom to the top were 3.3+/-4.1, 1.4+/-3.8. -0.6+/-1.9, -1.4+/-3.3, and -6.2+/-3.3 degrees anteriorly, indicating that the 3-dimensional bony structure of the glenoid was twisted anteriorly to posteriorly. Images on the bottom plane consisted of 82.5 % concave type, 15% flat type and 2.5% convex type, while only 3 cases (7.5%) showed concave at the top plane. The shape of the glenoid cavity is thought to be conducive to glenohumeral motion and stability.

Adolescent↗

PubMed2001

State of percutaneous transluminal coronary artery angioplasty and effectiveness of low-density lipoprotein apheresis.

We have recognized percutaneous transluminal coronary artery angioplasty (PTCA) as an important procedure for achieving myocardial revascularization. PTCA has been performed for stable and unstable angina, acute myocardial infarction, and silent myocardial ischemia. Among many new devices, the coronary stent is the most important advancement in PTCA. Frequent stent use is due to the introduction of antiplatelet therapy to prevent stent thrombosis. One serious problem is that PTCA, even with stent use, often causes chronic restenosis. This problem has not been solved, however, despite various strategies. Aggressive lipid-lowering therapy is one of the most important therapies for coronary heart disease. The findings in aggressive lipid-lowering therapy show us its importance. We report that low-density lipoprotein (LDL) apheresis, when performed immediately before and after PTCA, can prevent restenosis of coronary artery lesions. Lipid-lowering therapy should be applied more aggressively with medicine and/or with LDL apheresis for patients who have undergone PTCA.

Angioplasty, Balloon, Coronary↗

PubMed2001

Collagens XII and XIV (FACITs) in capsular opacification and in cultured lens epithelial cells.

PURPOSE: We previously reported that extracellular matrix (ECM) accumulation in human capsular opacification included collagen types I, III, IV, V, and VI. To further characterize the ECM in capsular opacification we performed immunohistochemistry to localize collagen types XII and XIV (fibril-associated collagens with interrupted triple helices, or FACITs) in specimens of human capsular opacification and in cultures of bovine lens epithelial cells (LECs). METHODS: Cryosections and paraffin sections of human capsular opacification specimens or uninjured lens capsules, as well as cultured bovine LECs, were processed for immunohistochemistry using antibodies against collagen types I to VI, XII, and XIV. A rat crystalline lens was punctured through the central cornea and the eye was processed for immunohistochemistry for FACITs after healing intervals. RESULTS: In the absence of injury human LECs were unstained for FACITs, but as early as 10 days after operation, LECs in healing capsules were immunoreactive. Collagen types I, III, IV, V, and VI were also detected. ECM deposited in confluent LEC cultures stained for FACITs. Normal rat LECs were not stained for FACITs, but ECM accumulated in injured lens stained for them. CONCLUSIONS: LECs up-regulate FACITs during post-opera-tive healing. FACITs, as well as other collagen types, are deposited in ECM in healing injured rat lens, in human capsular opacification and in LEC cultures. ECM components may regulate LEC behavior during postoperative healing.

Adult↗

PubMed2001

Differential transduction mechanisms underlying NaCl- and KCl-induced responses in mouse taste cells.

The transduction mechanism of salt-induced responses of mouse taste cells was investigated using the patch clamp and the local stimulation techniques under quasi-natural conditions. Apically applied NaCl induced a voltage-independent current, which was partially suppressed by amiloride and Cd2+. In contrast, apically applied 0.5 M KCl induced an inwardly rectifying current (KCl-induced Iir). The KCl-induced Iir was unaffected by amiloride. The Iir was suppressed not only by external Ba2+ and Cs+, but also by a Cl- channel blocker, niflumic acid. The Er of the KCl-induced response was independent of the apical ionic concentration, but rather was close to the equilibrium potential of Cl- (E(Cl)) at the basolateral membrane. The KCl-induced Iir displayed a fast run-down under the conditions of the conventional whole cell clamp method, but not under the perforated patch conditions. Immunohistochemical localization of an inwardly rectifying Cl- channel protein, ClC-2, was observed in taste bud cells of the fungiform papillae. It is concluded that the transduction mechanism of NaCl-induced responses is completely different from that of KCl-induced responses in mouse taste cells.

Amiloride↗

PubMed2001

Non-synaptic transformation of gustatory receptor potential by stimulation of the parasympathetic fiber of the frog glossopharyngeal nerve.

When the glossopharyngeal nerve (GP) in the frog was strongly stimulated electrically, slow potentials were elicited from the tongue surface and taste cells in the fungiform papillae. Injection of atropine completely blocked these slow potentials. The present and previous data indicate that the slow potentials induced in the tongue surface and taste cells are due to a liquid junction potential between saliva secreted from the lingual glands due to parasympathetic fiber activity and an adapting solution on the tongue surface. Intracellularly recorded depolarizing receptor potentials in taste cells induced by 0.5 M NaCl and 3 mM acetic acid were enhanced by depolarizing slow potentials induced by GP nerve stimulation, but were depressed by the hyperpolarizing slow potentials. On average, the receptor potential of taste cells for 0.5 M NaCl was increased by 25% by the GP nerve-induced slow potential, but the receptor potential of taste cells for 3 mM acetic acid was decreased by 1% by the slow potential. These transformations of receptor potentials in frog taste cells were not due to a synaptic event initiated between taste cells and the efferent nerve fiber, but due to a non-synaptic event, a lingual junction potential generated in the dorsal lingual epithelium by GP nerve stimulation.

Animals↗

PubMed2001

Reverse redistribution of 99m Tc-sestamibi after direct percutaneous transluminal coronary angioplasty in acute myocardial infarction: relationship with wall motion and functional response to dobutamine stimulation.

Reverse redistribution (RR) of 99mTc-sestamibi is observed after direct percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI). The purpose of this study was to clarify the functional characteristics of myocardial segments with RR after direct PTCA in AMI. Thirty patients with AMI who had undergone direct PTCA were examined. Myocardial perfusion tomography with 99mTc-sestamibi and low dose dobutamine echocardiography were performed within 2 weeks of the onset. The 99mTc-sestamibi images were obtained 1 and 3 h after tracer administration. The left ventricle was divided into nine segments, and regional 99mTc-sestamibi uptake and clearance were quantitatively evaluated in each segment. RR was defined as a decrease in 99mTc-sestamibi uptake of >10% on 3 h delayed images compared with the 1 h early images. The left ventricle in the echocardiographic images was also divided into nine segments corresponding to the scintigraphic images, and regional wall motion was assessed in the resting condition as the baseline and during dobutamine administration (5-10 microg x kg(-1) x min(-1)). Out of a total of 270 myocardial segments, 111 segments were perfused by the culprit coronary artery and were defined as ischaemic segments. There were 25 segments with RR and 86 segments without RR in the ischaemic myocardium. Enhanced clearance of 99mTc-sestamibi was observed in ischaemic segments with RR (P<0.001). Echocardiography demonstrated that 24 out of 25 segments with RR and 61 out of 86 segments without RR had wall motion abnormalities. Dobutamine infusion improved wall motion in 20 (83%) of the 24 dysfunctional segments with RR and 33 (54%) of the 61 dysfunctional segments without RR (P<0.02). These findings suggest that RR indicates reversible functional abnormalities associated with preserved contractile reserve in response to dobutamine. The early and delayed imaging of 99mTc-sestamibi provides useful information regarding the residual viability of the dysfunctional myocardium in AMI patients.

Acute Disease↗

PubMed2001

Life style and urinary 8-hydroxydeoxyguanosine, a marker of oxidative dna damage: effects of exercise, working conditions, meat intake, body mass index, and smoking.

The urinary levels of 8-hydroxydeoxyguanosine (8-OH-dG), a marker of oxidative DNA damage, of 318 healthy men aged 18 - 58 were measured with high resolution by a newly developed automated high-pressure liquid chromatography (HPLC) system coupled to an electrochemical detector (ECD). The mean 8-OH-dG level (mg / g creatinine) was 4.12 +/- 1.73 (SD). An eleven-fold inter-individual variation was observed. The accuracy of the measurement estimated from the recovery of an added 8-OH-dG standard was 90 - 98%. By univariate analysis, it was found that moderate physical exercise (P = 0.0023) and high body mass index (BMI) (P = 0.0032) reduced the 8-OH-dG level, while physical labor (P = 0.0097), smoking (P = 0.032), and low meat intake (less than once / week) (P = 0.041) increased its level. Based on a multi-regression analysis of the log-transformed values, moderate physical exercise (P = 0.0039), high BMI (P = 0.0099), and age (P = 0.021) showed significant reducing effects on the 8-OH-dG level, while low meat intake (P = 0.010), smoking (P = 0.013), and day-night shift work (P = 0.044) increased its level. These results suggest that many types of life-style factors that either generate or scavenge oxygen radicals may affect the level of oxidative DNA damage of each individual.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2001

Dendritic cell development from common myeloid progenitors.

Dendritic cells (DCs) are professional antigen-presenting cells which both initiate adaptive immune responses and control tolerance to self-antigens. It has been suggested that these different effects on responder cells depend on subsets of DCs arising from either myeloid or lymphoid hematopoietic origins. In this model, CD8 alpha+ Mac-1- DCs are supposed to be of lymphoid while CD8 alpha- Mac-1+ DCs are supposed to be of myeloid origin. Here we summarize our findings that both CD8 alpha+ and CD8 alpha- DCs can arise from clonogenic common myeloid progenitors (CMPs) in both thymus and spleen. Therefore CD8 alpha expression DCs does not indicate a lymphoid origin and differences among CD8 alpha+ and CD8 alpha- DCs might rather reflect maturation status than ontogeny. On the basis of transplantation studies, it seems likely that most of the DCs in secondary lymphoid organs and a substantial fraction of thymic DCs are myeloid-derived.

Animals↗

PubMed2001

Latent TGFbeta binding protein-1 and fibrillin-1 in human capsular opacification and in cultured lens epithelial cells.

BACKGROUND/AIM: It was previously reported that collagenous extracellular matrix (ECM) in human capsular opacification contained isoforms of transforming growth factor beta (TGFbeta). In the present study, the authors performed immunohistochemistry to examine whether ECM in human capsular opacification and in cultures of bovine lens epithelial cells (LECs) contained latent TGFbeta binding protein-1 (LTBP-1), TGFbeta1 latency associated peptide (beta1-LAP), and fibrillin-1, a suspected ligand of LTBP-1 as well as a component of the extracellular microfibrillar apparatus. The aim of the study was to further clarify the mechanism of TGFbeta1 deposition in ECM of capsular opacification. METHODS: Human capsular opacification specimens and uninjured lens capsules, as well as cultured bovine LECs, were processed for immunohistochemistry using antibodies against LTBP-1, beta1-LAP, fibrillin-1, and collagen type I. RESULTS: LTBP-1, beta1-LAP, and fibrillin-1 all were localised to the ECM in human capsular opacification. Uninjured lens epithelium stained for beta1-LAP, but not for LTBP-1 and fibrillin-1. ECM deposited in confluent LEC cultures stained for LTBP-1, beta1-LAP, and fibrillin-1, while cultures with only sparse cellularity were unstained for LTBP-1 or fibrillin-1. CONCLUSIONS: LECs upregulate LTBP-1 and fibrillin-1 during postoperative healing. LTBP-1, beta1-LAP, and fibrillin-1 colocalised to the ECM in capsular opacification and in confluent LEC cultures. TGFbeta1 is considered to deposit in ECM in the large latent form. ECM secreted by LEC may function as a scavenger or repository of TGFbeta.

Activin Receptors, Type I↗

PubMed2001

In vivo assessment of acetylcholine-releasing function at cardiac vagal nerve terminals.

We examined whether the ACh concentration measured by cardiac microdialysis provided information on left ventricular ACh levels under a variety of vagal stimulatory and modulatory conditions in anesthetized cats. Local administration of KCl (n = 5) and ouabain (n = 7) significantly increased the ACh concentration in the dialysate to 4.3 +/- 0.8 and 7.3 +/- 1.3 nmol/l, respectively, from the baseline value of 0.6 +/- 0.5 nmol/l. Intravenous administration of phenylbiguanide (n = 5) and phenylephrine (n = 6) significantly increased the ACh concentration to 5.4 +/- 0.9 and 6.0 +/- 1.5 nmol/l, respectively, suggesting that the Bezold-Jarisch and arterial baroreceptor reflexes affected myocardial ACh levels. Modulation of vagal nerve terminal function by local administration of tetrodotoxin (n = 6), hemicholinium-3 (n = 6), and vesamicol (n = 5) significantly suppressed the electrical stimulation-induced ACh release from 20.4 +/- 3.9 to 0.6 +/- 0.1, 7.2 +/- 1.9, and 2.7 +/- 0.6 nmol/l, respectively. Increasing the heart rate from 120 to 200 beats/min significantly reduced the myocardial ACh levels during electrical vagal stimulation, suggesting a heart rate-dependent washout of ACh. We conclude that ACh concentration measured by cardiac microdialysis provides information regarding ACh release and disposition under a variety of pathophysiological conditions in vivo.

Acetylcholine↗

PubMed2001

Cutaneous eruptions in coma patients with nontraumatic rhabdomyolysis.

BACKGROUND: Rhabdomyolysis has been described most commonly after muscle injury but may also result from coma due to alcohol intake or drug abuse. Its clinical findings usually occur as muscular pain and swelling, but these symptoms are also seen in as many as 60% of patients with nontraumatic rhabdomyolysis. The diagnosis of slight nontraumatic rhabdomyolysis is often difficult to establish clinically. Few previous studies have reported cutaneous symptoms in nontraumatic rhabdomyolysis. OBJECTIVE: We attempted to elucidate a relationship between nontraumatic rhabdomyolysis and cutaneous eruption. METHODS: We studied 7 patients who were diagnosed as having massive to slight nontraumatic rhabdomyolysis with a cutaneous eruption in pressure areas at the first visit to our hospital between March 28, 1988, and June 27, 1998. RESULTS: They revealed wine-red-colored urine and elevated serum myogenic enzyme. Two patients complained of muscle pain. In all patients, cutaneous eruptions including well-demarcated erythema, bullae and deep ulcers were observed in areas of pressure. The pathological findings of 5 cutaneous eruptions revealed necrosis of sweat ducts and glands in the dermis. CONCLUSIONS: The pathogenesis of nontraumatic rhabdomyolysis and the cutaneous eruptions in coma patients has not been elucidated, but these conditions are due to similar factors; pressure and hypoxia are considered to be important causative factors for both. Cutaneous eruptions in the coma patient may be an important clinical symptom of nontraumatic rhabdomyolysis.

Adolescent↗