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Biomedical subjects

Yasuyuki Matsushita

Publications and source records attributed to Yasuyuki Matsushita.

14 recordsLinked to original sources
PubMed2006

Hinokiresinol is not a precursor of agatharesinol in the norlignan biosynthetic pathway in Japanese cedar.

The biosynthetic relationship between the two norlignans agatharesinol and trans-hinokiresinol was investigated. Fresh sapwood sticks of Cryptomeria japonica were fed with stable isotope-labeled compounds, namely p-coumaryl alcohol-[9,9-(2)H], p-coumaryl alcohol-[9-(18)O] and trans-hinokiresinol-[1-(2)H], and then incubated under high-humidity for approximately 20 days, during which the two norlignans were produced simultaneously. While trans-hinokiresinol was strongly deuterium-labeled after feeding with p-coumaryl alcohol-[9,9-(2)H], agatharesinol was only lightly labeled after feeding with either p-coumaryl alcohol-[9,9-(2)H] or -[9-(18)O]. These results suggest that p-coumaryl alcohol, which is a precursor of hinokiresinol, is not involved in the biosynthesis of agatharesinol. Therefore, the norlignan carbon skeleton of agatharesinol must be framed from different types of phenylpropanoid monomers compared to those utilized by the trans-hinokiresinol pathway. The biosynthesis of these two norlignans seems to branch at an early stage, i.e., before the framing of the norlignan carbon skeleton. Furthermore, agatharesinol was not labeled with deuterium after feeding with (2)H-labeled trans-hinokiresinol, which has the simplest norlignan structure. This result strongly supports the suggestion that the conversion of trans-hinokiresinol to agatharesinol is not part of the biosynthesis of norlignans and that early branching occurs instead.

Coumaric Acids↗
PubMed2006

Enzymatic polymerization of coniferyl alcohol in the presence of cyclodextrins.

The dehydrogenative polymerization of coniferyl alcohol by horseradish peroxidase was performed in 0.10 M phosphate buffer at 27 degrees C. Dehydrogenative polymer (DHP) from coniferyl alcohol was characterized by size exclusion chromatography (SEC) and nuclear magnetic resonance (NMR) spectroscopy. The ratio of 8-O-4':8-5':8-8' linkages was determined by the 1H NMR spectrum of DHP acetate which had good solubility. In "end-wise like" polymerization (the slow addition of hydrogen peroxide), addition of alpha-cyclodextrin to the medium led to DHP with increased 8-O-4' content and a decrease in 8-5' linkages. Under higher pH conditions, DHP with higher 8-O-4' and 8-5' content was obtained in the presence of alpha-cyclodextrin. In the end-wise polymerization (the slow additions of coniferyl alcohol and hydrogen peroxide), using alpha-cyclodextrin also gave DHP with a 8-O-4' richer structure than that prepared in no additive system. The analysis of thioacidolysis products from DHP supported the results of the alpha-cyclodextrin effects on the 8-O-4'-rich structure of DHP. The 8-O-4' structure in DHP prepared in the presence of alpha-cyclodextrin had racemic form as shown by ozonation.

Animals↗
PubMed2006

Full-frame video stabilization with motion inpainting.

Video stabilization is an important video enhancement technology which aims at removing annoying shaky motion from videos. We propose a practical and robust approach of video stabilization that produces full-frame stabilized videos with good visual quality. While most previous methods end up with producing smaller size stabilized videos, our completion method can produce full-frame videos by naturally filling in missing image parts by locally aligning image data of neighboring frames. To achieve this, motion inpainting is proposed to enforce spatial and temporal consistency of the completion in both static and dynamic image areas. In addition, image quality in the stabilized video is enhanced with a new practical deblurring algorithm. Instead of estimating point spread functions, our method transfers and interpolates sharper image pixels of neighboring frames to increase the sharpness of the frame. The proposed video completion and deblurring methods enabled us to develop a complete video stabilizer which can naturally keep the original image quality in the stabilized videos. The effectiveness of our method is confirmed by extensive experiments over a wide variety of videos.

Algorithms↗
PubMed2005

Preparation and evaluation of lignosulfonates as a dispersant for gypsum paste from acid hydrolysis lignin.

In order to effectively utilize a by-product of the acid saccharification process of woody materials, the chemical conversion of guaiacyl sulfuric acid lignin (SAL), one of the acid hydrolysis lignins, into water-soluble sulfonated products with high dispersibitity was investigated. At first, SAL was phenolated (P-SAL) to enhance the solubility and reactivity. Lignosulfonates were prepared from P-SAL by three methods of hydroxymethylation followed by neutral sulfonation (two-step method), sulfomethylation (one-step method) and arylsulfonation. Surprisingly, all prepared lignosulfonates possessed 30 to 70% higher dispersibility for gypsum paste than the commercial lignosulfonate. Evaluation of the preparations for gypsum paste suggested that the higher molecular weights and sulfur contents of the preparations increased their dispersibility.

Agriculture↗
PubMed2005

Relation of serum total cholesterol and other factors to risk of cerebral infarction in Japanese men with hypercholesterolemia.

BACKGROUND: Risk factors for cerebral infarction have not been well clarified, except for hypertension (HT), and few studies have examined the risk factors in the elderly. METHODS AND RESULTS: Clinical and behavioral risk factors for cerebral infarction were examined in 4,349 Japanese men aged 45-74 years with a serum total cholesterol (TC) concentration of 220 mg/dl or greater who participated in the Kyushu Lipid Intervention Study. A total of 81 men developed definite cerebral infarction in a 5-year follow-up period. The Cox proportional hazards model was used with serum TC at baseline and during the follow-up, serum high-density lipoprotein-cholesterol (HDL-C), HT, diabetes mellitus (DM), and other factors as covariates. Serum TC during the follow-up, not at baseline, was positively associated with cerebral infarction, showing a stronger association in the elderly (>or=65 years old) than in the middle-aged (<65 years old). Statin use was related to a moderate decrease in the risk of cerebral infarction when follow-up TC was not considered, but the decrease was almost nullified after adjustment for follow-up TC. A low concentration of serum HDL-C, diabetes mellitus, hypertension, and angina pectoris were each related to an increased risk. No clear association was observed for body mass index, smoking or alcohol use. CONCLUSIONS: Lowering cholesterol is important in the prevention of cerebral infarction in men with moderate hypercholesterolemia. A low concentration of HDL-C, DM, and HT are independent predictors of cerebral infarction.

Aged↗
PubMed2004

Illumination normalization with time-dependent intrinsic images for video surveillance.

Variation in illumination conditions caused by weather, time of day, etc., makes the task difficult when building video surveillance systems of real world scenes. Especially, cast shadows produce troublesome effects, typically for object tracking from a fixed viewpoint, since it yields appearance variations of objects depending on whether they are inside or outside the shadow. In this paper, we handle such appearance variations by removing shadows in the image sequence. This can be considered as a preprocessing stage which leads to robust video surveillance. To achieve this, we propose a framework based on the idea of intrinsic images. Unlike previous methods of deriving intrinsic images, we derive time-varying reflectance images and corresponding illumination images from a sequence of images instead of assuming a single reflectance image. Using obtained illumination images, we normalize the input image sequence in terms of incident lighting distribution to eliminate shadowing effects. We also propose an illumination normalization scheme which can potentially run in real time, utilizing the illumination eigenspace, which captures the illumination variation due to weather, time of day, etc., and a shadow interpolation method based on shadow hulls. This paper describes the theory of the framework with simulation results and shows its effectiveness with object tracking results on real scene data sets.

Algorithms↗
PubMed2004

Relation of serum total cholesterol and other risk factors to risk of coronary events in middle-aged and elderly Japanese men with hypercholesterolemia: the Kyushu Lipid Intervention Study.

BACKGROUND: The role of serum total cholesterol (TC) in the development of coronary heart disease (CHD) may differ in different age groups. METHODS AND RESULTS: The relation of serum TC and other risk factors to CHD events was examined in middle-aged (<65 years) and elderly (> or =65 years) men separately in the Kyushu Lipid Intervention Study (KLIS). Subjects were 4,349 men aged 45-74 years with serum TC of 220 mg/dl or greater who had no history of myocardial infarction, coronary angioplasty, or stroke. There were 123 CHD events (ie, myocardial infarction, coronary bypass surgery, coronary angioplasty, cardiac death, and sudden death) in a 5-year follow-up period. The Cox proportional hazards model was used with baseline and follow-up serum TC, baseline high-density lipoprotein (HDL) cholesterol, hypertension, diabetes mellitus, and other factors as covariates. Serum TC concentration during the follow-up, not at baseline, was associated with an increased risk of CHD events, especially in elderly men. High concentrations of serum HDL cholesterol were associated with a modest, statistically nonsignificant decrease in the risk among middle-aged men. An increased risk of CHD events associated with diabetes mellitus was greater in middle-aged men. Hypertension and smoking were not measurably related to the risk in either middle-aged or elderly men. CONCLUSIONS: Both the serum TC concentration during follow-up and diabetes mellitus are important predictors of CHD events in Japanese men with moderately elevated serum TC.

Aged↗
PubMed2004

[Pharmacoeconomic analysis of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor therapy for the secondary prevention of coronary heart disease].

OBJECTIVE: The pharmacoeconomics of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (pravastatin) therapy were evaluated using data from an open-labeled, randomized, controlled trial (PCS: Prevention of Coronary Sclerosis study) with a two-year follow-up period. METHODS: Patients with a serum total cholesterol concentration of between 180 and 219 mg/dL at baseline were randomly assigned to two groups: the pravastatin group (n=54) and the group that did not receive cholesterol-lowering drugs (no-pravastatin group, n=66). A cost-minimization analysis and a cost-effectiveness analysis were then performed from the perspective of a health insurance company, using insurance information obtained from the subjects. In the cost-minimization analysis, the expected costs associated with percutaneous transluminal coronary angioplasty (PTCA) and the pravastatin prescription were compared; the total medication costs between the two groups were also compared. In the cost-effectiveness analysis, the estimated savings per event-free year were calculated. RESULTS: The median cost of a PTCA procedure was 1,323,492 yen. The expected insurance cost for two years was 182,532 yen per patient in the pravastatin group and 224,444 yen per patient in the no-pravastatin group. The cost-minimization analysis showed that the cost of healthcare for the no-pravastatin group was higher than that for the pravastatin group. The mean total cost of medication was 729,849 yen per patient in the pravastatin group and 989,606 yen per patient in the no-pravastatin group. The cost-effectiveness ratio for coronary heart disease was 2,766,994 yen. CONCLUSION: Pravastatin therapy in normocholesterolemic patients with coronary sclerosis seems to have an excellent pharmacoeconomic profile.

Adult↗
PubMed2003

A study to survey susceptible genetic factors responsible for troglitazone-associated hepatotoxicity in Japanese patients with type 2 diabetes mellitus.

BACKGROUND AND OBJECTIVE: Troglitazone is a 2,4-thiazolidinedione antidiabetic agent with insulin-sensitizing activities. This agent had been used efficiently in a large number of patients but was withdrawn from the market in March 2000 because of its association with idiosyncratic hepatotoxicity. To address the susceptible genetic factors responsible for the hepatotoxicity associated with this agent, we performed a genetic polymorphic analysis by a target gene approach in troglitazone-treated Japanese patients with type 2 diabetes mellitus. METHODS: One hundred ten patients treated with troglitazone were recruited into this study. The case patients (n = 25) were recruited through medical professionals who had previously reported abnormal increases in the levels of ALT or AST among their patients. The control patients (n = 85) were recruited through physicians prescribing troglitazone. For statistical accuracy, efforts were made to maximize the size of the case group. Genotype analysis was performed in 68 polymorphic sites of 51 candidate genes related to drug metabolism, apoptosis, roduction and elimination of reactive oxygen species, and signal transduction pathways of peroxisome proliferator-activated receptor gamma 2 and insulin. RESULTS: The strong correlation with transaminase elevations was observed in the combined glutathione-S-transferase GSTT1-GSTM1 null genotype (odds ratio, 3.692; 95% confidence interval, 1.354-10.066; P =.008). CONCLUSIONS: The double null mutation of GSTT1 and GSTM1 might influence troglitazone-associated abnormal increases of liver enzyme levels.

Aged↗
PubMed2003

Reduction in serum total cholesterol and risks of coronary events and cerebral infarction in Japanese men: the Kyushu Lipid Intervention Study.

Lowering serum total cholesterol is shown to decrease the risk of coronary heart disease (CHD) in Western countries,but evidence is limited regarding cerebral infarction (CI). The present study used the Kyushu Lipid Intervention Study to examine the risks of CHD events and CI in relation to reduction in serum total cholesterol. Subjects were 4,615 men aged 45-74 years with serum total cholesterol of 220 mg/dl (5.68 mmol/L) or greater who had no history of CHD events or stroke. CHD events and CI numbered 125 and 92, respectively, in a 5-year follow-up. After adjustment for potential confounding factors, the relative risks of CHD events and CI for 15% or greater reduction in total cholesterol, compared with less than 5% reduction, were 0.78 (95% confidence limit [CL]0.46-1.32) and 0.39 (95% CL 0.22-0.69), respectively. As compared with on-treatment cholesterol levels of 240 mg/dl (6.20 mmol/L)or higher, the risk of CHD events was approximately 50% lower across 3 categories below 240 mg/dl (6.20 mmol/L), and that of CI was 70%lower at 2 categories below 220 mg/dl (5.68 mmol/L). Lowering serum total cholesterol below 220 mg/dl (5.68 mmol/L) seems desirable with regard to the prevention of CI.

Aged↗
PubMedDate not supplied

Decorating surfaces with bidirectional texture functions.

We present a system for decorating arbitrary surfaces with bidirectional texture functions (BTF). Our system generates BTFs in two steps. First, we automatically synthesize a BTF over the target surface from a given BTF sample. Then, we let the user interactively paint BTF patches onto the surface such that the painted patches seamlessly integrate with the background patterns. Our system is based on a patch-based texture synthesis approach known as quilting. We present a graphcut algorithm for BTF synthesis on surfaces and the algorithm works well for a wide variety of BTF samples, including those which present problems for existing algorithms. We also describe a graphcut texture painting algorithm for creating new surface imperfections (e.g., dirt, cracks, scratches) from existing imperfections found in input BTF samples. Using these algorithms, we can decorate surfaces with real-world textures that have spatially-variant reflectance, fine-scale geometry details, and surfaces imperfections. A particularly attractive feature of BTF painting is that it allows us to capture imperfections of real materials and paint them onto geometry models. We demonstrate the effectiveness of our system with examples.

Algorithms↗
PubMedDate not supplied

In vitro study of a mandibular implant overdenture retained with ball, magnet, or bar attachments: comparison of load transfer and denture stability.

PURPOSE: When implants are used to support a removable overdenture, the optimal stress distribution to minimize both forces on the implants and denture movement is desirable. This study compared the stress patterns generated around implants and denture movement among three retention systems. MATERIALS AND METHODS: Two root-form implants were anchored in a mandibular model made of resin, and a removable overdenture on which all experiments were performed was fabricated. The surface of the model was covered with a layer of impression material to simulate oral mucosa. Ball/ O-ring, bar/clip, and magnetic attachments were used. A vertical force was applied to the left first molar and gradually increased from 0 to 50 N in 5-N steps. The resultant stress distribution and denture movement were evaluated. RESULTS: The ball/O-ring attachment transferred the least stress to both implants and produced less bending moment than the bar/clip attachment. Vertical force applied to the bar/clip attachment created immediate stress patterns of greater magnitude and concentration on both implants. CONCLUSION: This in vitro study suggested that the use of the ball/O-ring attachment could be advantageous for implant-supported overdentures with regard to optimizing stress and minimizing denture movement.

Analysis of Variance↗
PubMedDate not supplied

Thymidylate synthase expression as a predictor of the prognosis of curatively resected colon carcinoma in patients registered in an adjuvant immunochemotherapy clinical trial.

The expression levels of thymidylate synthase (TS) affect the sensitivity of tumor cells to fluorinated pyrimidine cytotoxic agents and determine the response of patients with colorectal cancer to fluorinated-pyrimidine-based chemotherapy. The correlation between the expression of TS and the prognosis of patients with colorectal cancer was examined in a prospective study. Evaluation of biomarkers including TS expression was performed using tumor specimens from 229 colorectal cancer patients. Immunohistochemical analysis of TS expression was performed using an antibody raised against a C-terminal epitope (D186-V313) of the human TS. The intensity of TS staining and the expression of other biomarkers were blindly scored. The five-year survival rates were 63.4% and 85.6% among patients with high and low intratumoral TS expressions, respectively (p=0.0007). Similarly, the disease-free survival (DFS) rate was 51.2% and 80.3% in the high and low TS expression groups, respectively (p=0.0004). In a subset analysis of Dukes' stage C patients, the survival and DFS rates were 44.0% and 40.0% in the high TS expression group, and 73.5% and 67.4% in the low TS expression group, respectively. Significant differences were observed in both survival (p=0.0048) and DFS (p=0.0054) rates. No significant correlation was observed between the expression of other biomarkers and prognosis. Significantly poorer prognosis of curatively resected colon cancer in patients with high TS expression levels in tumor tissue was confirmed by a double-blind prospective study conducted on samples obtained from patients enrolled in an adjuvant immunochemotherapy randomized clinical trial.

Adult↗