Search PubMed⌕ Search

Biomedical subjects

Y Toda

Publications and source records attributed to Y Toda.

At least 19 recordsLinked to original sources
PubMed2003

Layer-doubling method in ADF-STEM image simulation.

A layer-doubling method developed in LEED calculation is applied to the ADF-STEM image simulation. This approach makes it possible to simulate image intensities of systems having a repeated slab structure, such as embedded precipitates or defects, with a much higher efficiency because it does not require the diagonalization of repeated slabs. As a simple example of this method, channeling effects are calculated for a system with embedded crystalline displaced slabs for various different slab thicknesses.

Journal Article↗
PubMed2003

Agreement between frequency doubling perimetry and static perimetry in eyes with high tension glaucoma and normal tension glaucoma.

AIMS: To investigate the agreement in results between frequency doubling technology (FDT) and the conventional automated static perimeter in eyes with normal tension glaucoma (NTG) and high tension glaucoma (HTG). METHODS: 72 eyes of 36 patients, who had two or more experiences with the Humphrey field analyser (HFA) program C30-2, were examined with the screening C-20-1 program of FDT. The result of FDT at each of the 17 stimulus points was graded as one of four categories. 58 out of 76 test points of HFA were assigned to one of the 17 clusters corresponding to FDT test points. Each cluster was represented as the lowest (scotoma of HFA) or the highest (threshold of HFA) probability symbol of total deviation (TD) of the HFA test points included in the cluster. The agreement between scotoma/threshold of HFA and FDT results was evaluated for NTG and HTG. RESULTS: In a total of 65 eyes, the Spearman coefficients between the FDT and HFA (threshold/scotoma of HFA) were 0.599 and 0.515 (p<0.0001), respectively. In the HFA mean deviation matched 20 HTG eyes and 20 NTG eyes, the number of points with abnormal FDT results were 102 and 62 in eyes with HTG and NTG, respectively. The eyes with HTG had more abnormal FDT results than NTG eyes (p=0.0014, Mann-Whitney U test). The kappa coefficient between FDT and threshold of HFA in eyes with HTG and NTG was 0.288 and 0.520, respectively, and the agreement between FDT and scotoma of HFA was 0.480 and 0.439, respectively. CONCLUSIONS: The best agreement of the results of FDT and HFA was observed in eyes with NTG using threshold of HFA. The eyes with HTG showed lower agreement with more abnormal points in FDT results, which suggests enough sensitivity of FDT in eyes with NTG, and higher sensitivity of FDT in eyes with HTG.

Adult↗
PubMed2001

2-Acylimino-3H-thiazoline derivatives: a novel template for platelet GPIIb/IIIa receptor antagonists.

In the course of our research for the low-molecular weight RGD peptide mimics, we have found that a rigid 2-acylimino-3H-thiazoline structure is suitable for the peptide backbone mimics. Introduction of amidinophenyl and beta-alanine moiety as arginine and aspartic acid side-chain surrogates to this backbone mimic resulted in a highly potent fibrinogen receptor antagonist 2-(4-amidinobenzoylimino)-3,4-dimethyl-N-(2-carboxyethyl)-3H-thiazoline-5-carboxamide (7c), namely PS-028 (Ki = 46.5 +/- 5.8 microM).

Animals↗
PubMed2001

Uptake by vascular smooth muscle cells plays an important role in targeting of lipid microspheres incorporating prostaglandin E1 into a thickened intima.

A study was done to determine how lipid microspheres (LM) containing prostaglandin E1 (lipo PGE1) accumulate in injured arterial tissue. After administration of lipo PGE1 labeled with a fluorescence probe, 1,1'-dioctadecyl-3, 3, 3',3'-tetramethyl-indocarbocyanine perchlorate (DiI-lipo PGE1) to rats 14 of days after balloon injury of the carotid artery, localization into the injured site was examined using a fluorescence confocal laser scanning microscope (CLSM). In contrast with the normal carotid artery, DiI-lipo PGE1 accumulated remarkably in neointima of the injured site which was occupied mainly by the migration of the proliferating and quiescent vascular smooth muscle cells (SMC). In vitro cellular uptake of DiI-lipo PGE1 was semi-quantitatively measured using CLSM, regarding differentiated and proliferative phenotypes of human vascular SMC, compared with the human endothelial cells (EC) and mouse fibroblasts. The differentiated SMC incorporated DiI-lipo PGE1 to equal or a higher level of the proliferative phenotype, and was significantly higher than EC and fibroblasts. The uptake of DiI-lipo PGE1 by both SMC and EC was inhibited at 4 degrees C, by dansylcadaverine and excessive LM, but was unaffected by cytochalasin B. These results suggest that the uptake of DiI-lipo PGE1 by SMC plays an important role in localization of DiI-lipo PGE1 at the injured site, and that the uptake seems to be a receptor mediated endocytosis.

3T3 Cells↗
PubMed2001

Optimum treatment strategy for superficial esophageal cancer: endoscopic mucosal resection versus radical esophagectomy.

This study was designed to determine the optimum treatment for a superficial esophageal cancer involving the mucosal or submucosal layer of the esophagus. The subjects were 150 patients with a superficial esophageal cancer who underwent endoscopic mucosal resection (EMR) or esophagectomy in Kurume University Hospital from 1981 to 1997. The mortality and morbidity rates, survival rate, and recurrence rate were retrospectively compared for (1) 35 patients who underwent EMR and 37 patients who underwent esophagectomy for a mucosal esophageal cancer and (2) 45 patients who underwent extended radical esophagectomy and 33 patients who underwent less radical esophagectomy for a submucosal esophageal cancer. Among the 72 patients with a mucosal cancer, lymph node metastasis/recurrence was observed in only one (1%); whereas of 78 patients with a submucosal cancer it was observed in 30 (38%). Among patients with a mucosal cancer the mortality and morbidity rates after EMR were lower than for those after esophagectomy. The survival rate after EMR was the same as that after esophagectomy. No recurrence was observed after either treatment modality. Among the patients with a submucosal cancer, the survival rate was higher and the recurrence rate lower after extended radical esophagectomy; than after less radical esophagectomy; the mortality and morbidity rates after extended radical esophagectomy were the same as those after less radical esophagectomy. Multivariate analysis demonstrated that the treatment modality (EMR versus esophagectomy) did not influence the survival of patients with a mucosal esophageal cancer, whereas it strongly influenced the survival of patients with a submucosal esophageal cancer. We concluded that EMR was the mainstay of treatment for a mucosal esophageal cancer, and extended radical esophagectomy was the mainstay of treatment for a submucosal esophageal cancer.

Aged↗
PubMed2001

The effect of energy restriction, walking, and exercise on lower extremity lean body mass in obese women with osteoarthritis of the knee.

Two hundred and twenty-eight Japanese women, aged 45-69 years, with osteoarthritis of the knee (knee OA) and a body mass index of greater than 26.4 self-selected one of the following interventions: (1) a nonsteroidal anti-inflammatory drug (NSAID) alone (NA group; n = 52), (2) the NSAID with nonweight-bearing exercises (NE; n = 49), (3) the NSAID combined with walking (NW; n = 35), (4) an energy restriction diet plus the NSAID (ND; n = 29), (5) the diet combined with the NSAID and strengthening exercises (NDE; n = 37), or (6) the diet combined with the NSAID and walking (NDW; n = 26). Body weight and lower extremity lean body mass (L-LBM), assessed with segmental bioelectrical impedance, were measured at the outset and at 8 weeks in the six therapy groups. Interval changes in L-LBM and L-LBM per body weight (L-LBM/weight) were compared among the six groups at the conclusion. The Lequesne index can index of severity of osteoarthritis of the knee at the final assessment, compared with that at the initial assessment, was significantly decreased in the NE group, but not in the NW or the NA groups (P = 0.023). There was a significant increase in the L-LBM/weight in the NE group, but not in the NA or NW groups (P = 0.002 between NE and NA; P = 0.019 between NE and NW). There was a significant reduction in the Lequesne index in the NDE group in comparison with the ND and NDW groups (P = 0.0001 between NDE and ND; P = 0.0001 between NDE and NDW). There was a significant increase in L-LBM/weight in the NDE group, but not in the NDW or the ND groups (P = 0.011). Adjunctive therapy with nonweight-bearing lower extremity exercises appears to be more efficacious for prevention of lower extremity loss of muscle mass than adjunctive therapy with walking for obese women with knee OA.

Aged↗
PubMed2001

Heat shock protein (HSP) 47 and collagen are upregulated during neointimal formation in the balloon-injured rat carotid artery.

Heat shock protein (HSP) 47, a collagen-specific molecular chaperone, is thought to be essential for the proper processing and secretion of procollagen molecules. We investigated the time course and localization of HSP47 and collagen expression after balloon catheter angioplasty in the rat carotid artery, based on the premise that accumulation of extracellular matrix components is a main feature of intimal hyperplasia in humans and in laboratory animals. Low levels of HSP47 expression were evident in uninjured carotid arteries. Northern blot analysis revealed that HSP47 mRNA expression was markedly stimulated 1--3 days after the induced injury and a high level was maintained for 7 days, followed by a gradual decline for up to 21 days after the injury. These changes in HSP47 expression paralleled changes in alpha 1(I) collagen expression. Immunohistochemical staining revealed colocalization of HSP47 and collagen in smooth muscle cells (SMCs) of the media and intima. In situ hybridization analysis showed that activated SMCs, which proliferated and migrated into the intima, expressed high levels of HSP47. In cultured human aortic SMCs, similar upregulation of HSP47 and alpha1(I) collagen by TGF-beta was noted. These results show that SMCs activated after balloon injury express high levels of HSP47 and collagen during cell proliferation and migration, hence an overproduction of collagen and development of intimal thickening. Thus, HSP47 plays a role in the formation and progression of neointima after angioplasty.

Animals↗
PubMed2001

Microsatellite instability and alternative genetic pathway in intrahepatic cholangiocarcinoma.

BACKGROUND/AIMS: Intrahepatic cholangiocarcinoma (ICC) arises from intrahepatic bile duct epithelium and is the second most prevalent among primary liver cancers. The aim of this study was to clarify the mechanism of cholangiocarcinogenesis. METHODS: We studied the incidence of microsatellite instability (MSI) involving eight highly polymorphic microsatellite markers and alternations of the K-ras, p53 and mdm-2 genes in human ICC tissues. Overexpression of mdm-2 oncoprotein was also immunohistochemically studied. RESULTS: Of all 65 cases examined, K-ras gene mutation was found in three cases (4.6%) at codon 12. Analysis of p53 alterations was performed in 28 cases including 22 frozen samples and mutations were found in three cases (10.7%). Overexpression of mdm-2 protein was observed in 25 (41.7%) out of 60 cases analyzed. In 22 frozen samples, seven (31.8%) cases showed mdm-2 amplification and four (18.2%) cases revealed MSI-positive phenotype. Among the cases analyzed, all the tumors with mdm-2 amplification/overexpression harbored the wild-type p53 gene and all the microsatellite instability-positive cases were from mass-forming (MF) + periductal-infiltrating (PI) subtype. CONCLUSIONS: These results suggest that mdm-2 plays a role, which might be partially through inhibiting p53 activity, in cholangiocarcinogenesis and that M

Adult↗
PubMed2001

Taurine inhibits development of atherosclerotic lesions in apolipoprotein E-deficient mice.

1. The effects of taurine on the development of atherosclerotic lesions were investigated in apolipoprotein (apo) E-deficient mice, an animal model with severe hypercholesterolaemia and extensive atherosclerosis. These mice were fed a normal laboratory chow containing 2% taurine for 12 weeks. 2. Serum total cholesterol was significantly elevated after 12 weeks treatment with taurine. This elevation was due to increases in very low-density lipoprotein- and low-density lipoprotein-cholesterol. 3. Despite such effects on serum lipoproteins, analysis using en face oil red O staining revealed that taurine reduced the area of arterial lipid accumulation by 28%, as measured quantitatively as an index of atherosclerosis. Histological examination also demonstrated a decrease in the size of aortic lesions in taurine-treated mice. 4. Serum levels of thiobarbituric acid reactive substances (TBARS) in apoE-deficient mice were higher than in normolipidaemic C57BL/6J mice. Serum TBARS levels were significantly decreased by 12 weeks treatment of apoE-deficient mice with taurine. 5. Thus, taurine prevents the formation of atherosclerotic lesions, independently of serum cholesterol levels, and the results suggest that the anti-oxidative effects of taurine are related to its anti-atherosclerotic actions.

Animals↗
PubMed2001

Two configurations of static magnetic fields for treating rheumatoid arthritis of the knee: a double-blind clinical trial.

OBJECTIVE: To assess the efficacy of a nonpharmacologic, noninvasive static magnetic device as adjunctive therapy for knee pain in patients with rheumatoid arthritis (RA). DESIGN: Randomized, double-blind, controlled, multisite clinical trial. SETTING: An American and a Japanese academic medical center as well as 4 community rheumatology and orthopedics practices. PATIENTS: Cohort of 64 patients over age 18 years with rheumatoid arthritis and persistent knee pain, rated greater than 40/100mm, despite appropriate use of medications. INTERVENTION: Four blinded MagnaBloc (with 4 steep field gradients) or control devices (with 1 steep field gradient) were taped to a knee of each subject for 1 week. MAIN OUTCOME MEASURES: The American College of Rheumatology recommended core set of disease activity measures for RA clinical trials and subjects' assessment of treatment outcome. RESULTS: Subjects randomly assigned to the MagnaBloc (n = 38) and control treatment groups (n = 26) reported baseline pain levels of 63/100mm and 61/100mm, respectively. A greater reduction in reported pain in the MagnaBloc group was sustained through the 1-week follow-up (40.4% vs 25.9%) and corroborated by twice daily pain diary results (p < .0001 for each vs baseline). However, comparison between the 2 groups demonstrated a statistically insignificant difference (p < .23). Subjects in the MagnaBloc group reported an average decrease in their global assessment of disease activity of 33% over 1 week, as compared with a 2% decline in the control group (p < .01). After 1 week, 68% of the MagnaBloc treatment group reported feeling better or much better, compared with 27% of the control group, and 29% and 65%, respectively, reported feeling the same as before treatment (p < .01). CONCLUSIONS: Both devices demonstrated statistically significant pain reduction in comparison to baseline, with concordance across multiple indices. However, a significant difference was not observed between the 2 treatment groups (p < .23). In future studies, the MagnaBloc treatment should be compared with a nonmagnetic placebo treatment to characterize further its therapeutic potential for treating RA. This study did elucidate methods for conducting clinical trials with magnetic devices.

Arthralgia↗
PubMed2001

Significance of adrenomedullin under cardiopulmonary bypass in children during surgery for congenital heart disease.

To elucidate the effect of adrenomedullin (AM) on fluid homeostasis under cardiopulmonary bypass (CPB), we investigated the serial changes in plasma AM and other parameters related to fluid homeostasis in 13 children (average age, 28.2 months) with congenital heart disease during cardiac surgery under CPB. Arterial blood and urine samples were collected just after initiation of anesthesia, just before commencement of CPB, 10 min before the end of CPB, 60 min after CPB, and 24 h after operation. Plasma AM levels increased significantly 10 min before the end of CPB and decreased 24 h after operation. Urine volume increased transiently during CPB, which paralleled changes in AM. Simple regression analysis showed that plasma AM level correlated significantly with urinary vasopressin, urine volume, urinary sodium excretion, and plasma osmolarity. Stepwise regression analysis indicated that urine volume was the most significant determinant of plasma AM levels. Percent rise in AM during CPB relative to control period correlated with that of plasma brain natriuretic peptide (r = 0.57, P < 0.01). Our results suggest that AM plays an important role in fluid homeostasis under CPB in cooperation with other hormones involved in fluid homeostasis.

Adrenomedullin↗
PubMed2001

Possible participation of isolated epicardial cell clusters in the formation of chick embryonic epicardium.

The embryonic epicardium is formed by the spreading of cells derived from the extracardiac proepicardial organ over the myocardial surface after transfer to the dorsal side of the myocardium via a bridge of villous projections. Using whole-heart immunostaining for keratin, we found that the chronology and pattern of epicardial formation in the chick was basically identical to that reported previously in the quail. However, discrete epicardial islands were observed on the ventrolateral surface of the atrioventricular canal as well as in two previously reported areas. Closer examination by scanning electron microscopy demonstrated the presence of isolated, sparsely distributed epicardial cell clusters on both the dorsal and ventral surfaces of the myocardium. These cells showed a surface morphology similar to that of the epicardial cells at the advancing edge of the spreading epicardial sheet and possessed numerous well-developed filopodia, suggesting active motility. These clusters are probably seeded onto the myocardium by vesicular transport from proepicardial villi, and our findings suggest that the resulting small, localised patches of epicardial cells might accelerate, supplement and tune the epicardial formation mediated by radial spreading of the epicardial sheet in the chick embryonic heart.

Animals↗
PubMed2001

Intraarterial corticosteroid infusion following radiotherapy for primary central nervous system lymphoma: feasibility and preliminary result.

To utilize the high lympholytic effect of corticosteroids with minimal systemic adverse effects, we used intraarterial corticosteroid infusion in the treatment of 8 patients with primary central nervous system lymphoma (PCNSL). One patient had recurrent PCNSL, while the other patients had primary disease. Following standard radiotherapy with or without some systemic or intrathecal chemotherapy, prednisolone (60-100 mg in total) or dexamethazone (12 mg in total) was rapidly infused through the carotid arteries in all patients and also through the left vertebral artery in 5 patients. No acute or late complications of this treatment were observed. All 8 patients achieved complete or partial response. Four patients died of the disease, while the other 4 were alive with (1 patient) or without (3 patients) disease at 8-37 months after treatment, giving a 2-year survival rate of 55%. Intraarterial administration of high-dose corticosteroids appears to be a feasible treatment modality. This method may be used in preradiotherapy setting to evaluate response of PCNSL in future studies.

Adrenal Cortex Hormones↗
PubMed2001

[The clinical evaluation of the lateral wedged insole fixed elastically on the subtalar joint of patients with osteoarthritis of the knee].

We assessed the clinical efficacy of a lateral wedged insole with elastic fixation of the subtalar joint for conservative treatment of osteoarthritis of the knee. Novel insoles with elastic subtalar fixation (fixed insole) and a traditional shoe insert wedged insoles (inserted insole) were prepared. Seventy-one new female outpatients with osteoarthritis of the knee (knee OA) were treated with wedged insoles for 3 months. Randomization was performed according to birth date. The Severity Index of Lequesne, et al at the final assessment was compared with that at baseline in both the inserted and fixed insole groups. There were 37 participants in the inserted group and 34 participants in the fixed insole group. Regarding discomfort during nocturnal bed rest, 21 out of 34 (61%) participants were positive at the baseline assessment, however, only 8 out of 34 (27%) were positive at the final assessment in the fixed insole group (P = 0.033). In the fixed insole group, the number of participants complained immediate pain after walking was decreased from 28 (82%) at the baseline assessment to 17 (50%) at the final assessments (P = 0.0104). These significant differences were not found in the group with the inserted insole. Thus, clinical efficacy of lateral wedged insole may be emphasized with elastic fixation of the subtalar joint.

Aged↗