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T Takashima

Publications and source records attributed to T Takashima.

At least 73 records · Page 4Linked to original sources
PubMed1998

RF system of the SPring-8 storage ring.

Construction of three RF stations in the storage ring of SPring-8 has been completed. The design concept concentrates on avoiding a coupled-bunch instability which limits the stored current or makes the synchrotron radiation beam unstable. The cavity is bell-shaped to reduce the coupling impedance of the higher-order modes. The cavity dimensions are trimmed systematically to distribute the higher-order mode frequencies. Each cavity has two movable tuners. The temperature of the cavity cooling water is controlled within 0.02 K and the water flow is kept constant. The construction and commissioning of the SPring-8 storage ring RF system is reported.

Journal Article↗
PubMed1998

The 5-HT3 receptor agonist attenuates the action of antidepressants in the forced swim test in rats.

Involvement of 5-hydroxytryptamine (5-HT)3 receptors in action of antidepressants was examined in the forced swim test in rats. Rats were forced to swim in a cylinder for 15 min on day 1 and for 5 min on day 2. Imipramine, desipramine and mianserin, administered after the 15-min swim session on day 1 and before the 5-min swim test on day 2, dose-dependently decreased the duration of immobility in the swim test on day 2. 1-(m-Chlorophenyl)-biguanide (mCPBG) attenuated the decreased duration of immobility induced by imipramine, desipramine and mianserin, although mCPBG did not affect the duration of immobility when it was given alone. ICS205-930 dose-dependently decreased the duration of immobility in the swim test on day 2, and the effect of ICS205-930 was attenuated by mCPBG. These results suggest that the suppression of 5-HT3 receptor activity may contribute to the action of antidepressants.

Animals↗
PubMed1998

Ultimate observation of tungsten atoms and clusters adsorbed on single crystalline MgO films.

Tungsten single atoms and clusters composed of four and five atoms deposited on MgO (001) thin films were observed by high-resolution transmission electron microscopy at R.T. The observation was realized by optimizing the thickness of the MgO films and by using special imaging techniques such as an off-Bragg HREM method. The multislice simulation for the interpretation of the image contrast showed a possibility of discrimination of the atomic configuration of clusters, such as "b.c.c.," "on-top," or "f.c.c." type clusters, from details of the image-contrast. The image intensity at the center of the clusters with the b.c.c. configuration was evidently smaller than that of the clusters with the f.c.c. configuration. The reason for the difference was clarified through the multislice image simulation, suggesting that the lattice mismatch between the clusters and the MgO lattice was a key factor in determining the intensity of the center of the clusters.

Adsorption↗
PubMed1998

Biochemical modulation therapy for pancreatic cancer.

It is well known that the clinical course in most patients with advanced pancreatic cancer is not influenced substantially by chemotherapy and/or radiotherapy. However, new chemotherapy, based on the synergistic antitumor activities of 5-fluorouracil (5-FU) and cisplatin (CDDP) producing biochemical modulation in solid cancers diagnosed as adenocarcinoma, has recently been reported to be effective. In gastrointestinal cancers, the optimal concentrations of each drug and the duration of the anticancer effects, as well as adverse effects have been confirmed in pharmacodynamic studies. Our experience of this treatment for advanced pancreatic cancer (stage IV) indicates the usefulness of the antitumor effect in terms of both effect on the tumor size in unresectable patients and prognosis in resectable patients. These results were remarkable in patients diagnosed as stage IV b and/or curability C. Although there were adverse effects, none were severe. However, anything compromising the patient's quality of life must be prevented. Randomized prospective studies of the combination of 5-FU and CDDP are expected in the near future.

Adenocarcinoma↗
PubMed1998

A new complex translocation (15;20;17)(q22;p13;q21) in acute promyelocytic leukemia.

We describe here a 39-year-old male with acute promyelocytic leukemia (APL) carrying a new complex translocation (15;20;17). A chromosomal analysis of the bone marrow cells showed 46, XY, t(15;20;17)(q22;p13;q21). Fluorescence in situ hybridization (FISH) analysis using plasmid DNA libraries of chromosomes 15, 17, and 20 revealed three derivative chromosomes, der(15)t(15;17), der(17)t(17;20), and der(20)t(15;20). Fluorescence in situ hybridization with cosmid DNA probes flanking the breakpoints of t(15;17) did not show the retinoic acid receptor alpha (RAR alpha)/PML fusion signal usually generated on the der(17)t(15;17). However, rearrangement of the RAR alpha gene and expression of the PML/RAR alpha chimeric transcript were identified by Southern blot and reverse-transcriptase polymerase chain reaction (RT-PCR) analyses, respectively. Our results confirmed that the PML/RAR alpha gene on the der(15)t(15;17), not the RAR alpha/PML gene, must be essential to leukemogenesis in APL. Furthermore, considering another reported case with a 20p13 aberration, it is possible that 20p13 is a nonrandom breakpoint in APL with a complex translocation.

Adult↗
PubMed1998

Effect of lipo-pro-prostaglandin E1, AS-013 on rat inner ear microcirculatory thrombosis.

We investigated effects of lipo-pro-prostaglandin E1 (lipo-[11alpha, 13E, 15S]-11,15-dihydroxy-9-[1-oxobutoxy]-prosta-8, 13-dien-1-oic acid butyl ester), AS-013 in two models of hearing disturbance and equilibrium dysfunction induced by rat inner ear microcirculatory thrombosis. Inner ear microcirculatory thrombosis was induced by photochemical reaction between systemic injection of Rose Bengal and irradiation of green light to the cochlea and vestibule. Photochemical reaction causes endothelial injury followed by platelet adhesion, aggregation and formation of a platelet- and fibrin-rich thrombus. In the hearing disturbance model, a compound cochlear nerve action potential was recorded by electrocochleography every minute. Photochemical reaction induced inner ear microcirculatory thrombosis, followed by disappearance of the action potential. AS-013 significantly (P<0.05) prolonged time to disappearance of the action potential compared with control group. In the equilibrium dysfunction model, the irradiation to the vestibule was applied for 10 min after Rose Bengal injection. The behavior of rats in the swimming test and nystagmus were observed 24 h after the completion of irradiation. In the swimming test, two of 12 animals treated with AS-013 showed no rotating about their longitudinal axes, which indicates equilibrium dysfunction and the duration of well-balanced swimming prolonged. AS-013 suppressed the appearance of nystagmus. These results suggest that lipo-pro-prostaglandin E1, AS-013 may prevent hearing disturbance and equilibrium dysfunction due to inner ear microcirculatory disorders.

Action Potentials↗
PubMed1998

Clinical value of MRA analysis of the vertebrobasilar system in vertiginous patients.

Vertebrobasilar haemodynamics correlate closely with syndromal vertigo. The aim of this study is to examine the clinical value of MRA for evaluation of vertebrobasilar haemodynamics in vertiginous patients. We examined 40 individuals (20 with vertebrobasilar insufficiency and 20 diagnosed with other vestibular disorders). MRA results were quantified on the basis of the severity of vascular stenosis in the major arteries of the vertebrobasilar system and we analysed the relationship of these results with otoneurological diagnoses, eye-tracking tests (ETT) and optokinetic nystagmus (OKN). MRA results correlated well with otoneurological diagnoses and ETT results. Consequently, MRA can be used as a screening examination to evaluate vertebrobasilar haemodynamics and ETT may be a sensitive functional parameter of vertebrobasilar insufficiency.

Adult↗
PubMed1998

Evaluation of the vertebrobasilar artery system by magnetic resonance angiography in the diagnosis of vertebrobasilar insufficiency.

To evaluate the advantages of magnetic resonance angiography (MRA) in assessing the vertebrobasilar artery system for diagnosing vertebrobasilar insufficiency (VBI), we compared the MRA results of middle-aged and older VBI cases with those of age-matched peripheral disorder cases. There were no significant differences in the rate of complications associated with atherosclerosis between VBI cases and peripheral disorder cases. The MRA results were quantitatively assessed by scores determined on the basis of the severity of stenosis in the vertebral arteries and basilar artery. The MRA score was defined as the total score of these three arteries. The severity of stenosis and the MRA score of VBI cases were significantly higher than those of peripheral cases. MRA can therefore be of value as a screening examination for estimating vertebrobasilar blood flow and can provide helpful information for diagnosing VBI.

Aged↗
PubMed1998

Quantitative analysis of correlation between smooth pursuit and vertebrobasilar hemodynamics.

The cerebellar arterial system is derived from the vertebrobasilar system. However, the relation between cerebellar function and vertebrobasilar hemodynamics remains poorly understood. In this study on patients with vertebrobasilar insufficiency symptoms we examined the relation between magnetic resonance angiography (MRA) abnormalities in the vertebrobasilar system and smooth pursuit function, which is a sensitive parameter of cerebellar function. MRA abnormality was quantitatively assessed on the basis of the severity of stenosis in the vertebral arteries and basilar artery, and on the visualization of the superior cerebellar arteries. Smooth pursuit dysfunction was quantified by the combined amplitude of spikes on an electronystagmograph. A significant correlation was found between MRA abnormality and smooth pursuit dysfunction. This suggests that smooth pursuit dysfunction is closely related to static factors of dysregulation of vertebrobasilar blood flow. Therefore, smooth pursuit can be valued as a sensitive parameter to dysfunction of vertebrobasilar blood flow.

Aged↗
PubMed1998

Comparative assessment of cell proliferation and accumulation of extracellular matrix in nasal polyps.

In nasal polyps constantly associated with chronic inflammation, a dysregulation of epithelial cell proliferation has been described. Involvement of extracellular matrix accumulation is also suggested in the formation and growth of nasal polyps. In this study, we attempted to evaluate the activity of the proliferation of epithelial cells and fibroblasts and the relation between fibronectin accumulation and these cell proliferations in nasal polyps. The pathological specimens of 30 patients were examined which manifested proliferating cell nuclear antigen (PCNA) expression in epithelial cells and fibroblasts and in fibronectin expression. PCNA expression was quantified by calculating the index for each sample. No significant difference in PCNA index was found between epithelial cells and fibroblasts. However, a significant correlation was found between the epithelial and fibroblastic PCNA index. In addition, fibronectin immunopositivity was well correlated with the activity of proliferation of fibroblasts. Therefore, proliferation of fibroblasts is also an important factor in the growth of nasal polyps, and its relationship with fibronectin accumulation may play a role in the pathogenesis of nasal polyposis.

Adult↗
PubMed1998

Hypervascular hepatocellular carcinoma: evaluation of hemodynamics with dynamic CT during hepatic arteriography.

PURPOSE: To assess the hemodynamics and the main drainage vessel of hypervascular hepatocellular carcinoma. MATERIALS AND METHODS: Single-level dynamic computed tomography during hepatic arteriography (CTHA) was performed in 32 patients with hepatocellular carcinoma. Carcinoma was confirmed with histologic (n = 9) or clinical (n = 23) examination results. Single-level CTHA findings were retrospectively analyzed. Histologic specimens from 40 livers with hepatocellular carcinoma were also examined, with special attention to vessels along the rim of the lesion. RESULTS: Contrast material enhancement on single-level CTHA images occurred in four phases: (a) inflow of the contrast material into tumor, (b) tumor enhancement, (c) inflow of the contrast material into adjacent liver, and (d) corona enhancement of adjacent liver. Corona enhancement was seen in all lesions. A bright branching structure in the corona enhancement area, suggestive of a portal venule, was visible at the start of adjacent liver staining in 21 lesions. Continuity between a tumor sinusoid and a tiny vessel in the inner layer of the pseudocapsule was histologically confirmed in 10 of 40 specimens. Continuity between a tiny vessel in the inner layer and a portal vein in the outer layer of the pseudocapsule was confirmed with findings on serial sections from one liver. CONCLUSION: The main drainage of hepatocellular carcinoma lesions may be a protal venule.

Carcinoma, Hepatocellular↗
PubMed1998

The antiatherogenic effect of nifedipine on intramural small coronary arterial lesions in cholesterol-fed rabbits.

The objective of this study was to examine the suppressive effect of nifedipine on intramural coronary arterial lesions in cholesterol-fed rabbits. Each rabbit in Groups A (n=6) and B (n=5) was fed a 0.3% cholesterol diet and was orally administered nifedipine (40 mg/day) or placebo. Each rabbit in Groups C (n=5) and D (n=6) was fed a 0.5% cholesterol diet and was orally administered nifedipine (40 mg/day) or placebo. The serum concentrations of total cholesterol (TC) were determined at 1-week intervals to calculate the integrated values. The lesion induction ratio was defined as the ratio of intramural coronary arteries 50-150 microm in diameter with arterial lipoidosis to the total number of arteries of the same diameter. There were no significant differences between the nifedipine-treated and placebo groups in either the integrated TC or lesion induction ratio in either the 0.3% and 0.5% cholesterol-fed rabbits. This study demonstrates that nifedipine does not suppress atherogenesis in the intramural small coronary arteries of cholesterol-fed rabbits.

Administration, Oral↗
PubMed1998

Suppressive effect of simvastatin on intramural small coronary arterial lesions in cholesterol-fed rabbits.

The aim of this study was to examine the suppressive effect of simvastatin on intramural coronary arterial lesions in cholesterol-fed rabbits. In one experiment, six groups of rabbits were fed laboratory chow alone or with added 0.1%, 0.2%, 0.3%, 0.5% or 1.0% cholesterol for 16 weeks. In another experiment, four groups of rabbits were fed a 0.5% cholesterol diet and treated with simvastatin at 1, 3, or 5 mg/kg/day or placebo. In each rabbit, the levels of serum total cholesterol (TC) were determined at 1-week intervals to calculate the integrated values. The lesion induction ratio was defined as the ratio of intramural coronary arteries 50-150 microm in diameter with arterial lipoidosis to the total number of arteries of the same diameter. In the two experiments, there were positive correlations between the lesion induction ratio and integrated TC (r=0.785, P<0.0001 and r=0.763, P<0.0001, respectively). The slopes of the regression lines for integrated TC obtained in the two experiments were similar, but the lesion induction ratio in the simvastatin-treated group was always lower, by about 14%, in comparison with that in the non-simvastatin-treated group. These findings suggest that simvastatin induces lesion reduction not only by reducing the levels of circulating cholesterol but also by directly suppressing the development of lipoidosis.

Animals↗
PubMed1998

[Diagnosis of the wall-thickened lesions of the gallbladder with dynamic MRI].

We studied 32 patients with the thickened lesions of the wall of the gallbladder by using dynamic MRI. We tried the differential diagnosis of gallbladder lesions according to the time intensity curve (TIC) and enhanced pattern. TIC of carcinoma was elevated more seeply from plain to arterial phase than the inflammatory diseases. The Inflammatory diseases were keeping three-layer structures of the wall of the gallbladder, but gallbladder carcinoma destroys the wall-structure. We could diagnose as direct liver invasion of the carcinoma clearly. We could exactly diagnose adenomyomatosis in dynamic MRI by small low intensity spots within the wall of the gallbladder. In the patients with gall stones, the wall of the gallbladder were more clearly observed in dynamic MRI compared with US and EUS.

Carcinoma, Adenosquamous↗
PubMed1998

[Usefulness of T2-weighted images using single shot fast spin echo (SSFSE) pulse sequence for the evaluation of pancreatobiliary diseases: comparison with MRCP using SSFSE].

Single shot fast spin echo (SSFSE) pulse sequence provides us with a thick single-slice MR cholangiopancreatography (MRCP) as well as thin multi-slice MRCP, and T2-weighted images are also obtained with SSFSE sequences. In comparison with conventional spin-echo and fast spin-echo sequences, T2-weighted image using SSFSE sequence has the advantages of the abscence of motion artifacts and the extremely short acquisition times. MRCP using SSFSE sequence is useful in the conspicuity of bile duct, pancreatic duct, and cystic lesions. However, T2 weighted image using SSFSE is superior to MRCP not only for the differentiation between solid and cystic lesions but also for the visualization of contour of different organs and lesions.

Biliary Tract Diseases↗
PubMed1998

[What 100 HPN patients taught us].

Recently, Terumo Corporation has developed a new management system, 'Home-Joint', which helps hospitals discharge patients easily. Several hospitals have adopted this system for HPN (home parenteral nutrition) patients, as it can provide discharge program from the hospital and provide items required in alternate site care. This report gives an evaluation of 100 HPN patients who underwent 'Home-Joint' program in 1997. 1) Profiles of patients. Number: 100 (female 47, male 53) Age: 26-96 (61 patients over 70) DIAGNOSIS: cancer 57, others 21, unknown 22 Therapeutic periods: average 53 days (2-617) for terminated 84 patients. Infusion Devices: ambulatory pump 55, stationary pump 41, gravity 4. 2) Important factors for HPN support 1. Be reliable for patients and staff. 2. Train patients well before discharge. 3. The simpler the device the better. 4. Trial or short home-coming required. 3) Issues. 1. Compared with other home therapies, HPN blood access requires much care. 2. Therapeutic period too short. 3. Pay for HPN service too small for a business HPN is very useful for the hospital to discharge the patient comfortably, but requires a complete service system and suitable reimbursement for business.

Adult↗
PubMed1997

The GABA(B) receptor antagonist CGP36742 attenuates the baclofen- and scopolamine-induced deficit in Morris water maze task in rats.

Effects of CGP36742 (3-aminopropyl-n-butylphosphinic acid), an orally active GABA(B) receptor antagonist, on the baclofen- and scopolamine-induced deficit of place learning in the Morris water maze task were examined in rats. Rats were given four training trials per day with the submerged platform at a fixed location in the maze for 4 days. On day 4, the rats were required to swim in the pool without the platform after the fourth training trial (probe test). Intraperitoneal injection of baclofen (4 mg/kg) or scopolamine (0.3 mg/kg) significantly increased the escape latency to reach the platform and decreased the duration in the quadrant where the platform had been originally located. Increased latency in the training trials and decreased duration in the probe test induced by baclofen or scopolamine were significantly attenuated by oral administration of CGP36742 at doses of 10 and 30 mg/kg. In the rotarod test, CGP36742 at a dose of 100 mg/kg but not at doses of 10 or 30 mg/kg antagonized the baclofen-induced motor incoordination. Thus, there was dissociation between the effective doses of CGP36742 in the learning task and those in the sensory motor test. These results suggest the possible involvement of cholinergic systems as well as GABA(B) receptor systems in the CGP36742 action.

Animals↗