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Biomedical subjects

Fumitaka Ohsuzu

Publications and source records attributed to Fumitaka Ohsuzu.

At least 37 records · Page 2Linked to original sources
PubMed2005

Close relationship between the vasodilator response to acetylcholine in the brachial and coronary artery in suspected coronary artery disease.

BACKGROUND: Vasodilator response to acetylcholine (endothelium-dependent dilation) is impaired in the peripheral and coronary circulation in patients with coronary artery disease (CAD). The purpose of this study is to investigate if the vasodilator response to acetylcholine in the brachial artery (BA) correlates with the same response in the coronary artery (CA). STUDY: We measured the flow responses of BA and CA in 57 patients with suspected CAD. Doppler guidewire was placed into the proximal portion of the left BA and the major branch of CA. Acetylcholine was infused at 7.5, 15, and 30 mug/min for 5 min into BA and at 10(-8), 10(-7), 10(-6) M for 3 min into CA, respectively. The flow was calculated by multiplying average peak velocity by cross sectional areas obtained from quantitative angiography. Vasodilator response to acetylcholine was assessed by ratio of acetylcholine-induced flow/baseline flow. RESULTS: A total of 33 CAD patients (CAD group, 61+/-8 years old) and 24 normal coronary patients (NL group, 57+/-12 years old) were investigated. A strong correlation between the vasodilator response to acetylcholine in BA and CA was observed in both CAD and NL groups, only at two moderate doses of acetylcholine (CAD group, r=0.64, p<0.001, NL group, r=0.87, p<0.001, 15 microg/min vs. 10(-7) M; CAD group, r=0.68, p<0.001, NL group, r=0.72, p<0.001, 30 microg/min vs. 10(-6) M). No significant correlation was obtained during low dose acetylcholine infusion. CONCLUSIONS: The brachial artery vasodilator response to optimal acetylcholine doses is a useful surrogate for coronary endothelial function studies.

Acetylcholine↗
PubMed2005

Involvement of tumor necrosis factor-alpha in the development of T cell-dependent aortitis in interleukin-1 receptor antagonist-deficient mice.

BACKGROUND: Interleukin-1 receptor antagonist-deficient (IL-1Ra(-/-)) mice on the BALB/c background spontaneously develop inflammatory arthropathy that resembles rheumatoid arthritis in humans. These mice also frequently develop aortitis at the root of the aorta, but the mechanism underlying the development of this disease has not been completely elucidated. METHODS AND RESULTS: Using IL-1Ra(-/-) mice (backcrossed 8 generations to the BALB/c background) and wild-type mice, we studied the histopathology and examined the immunologic mechanisms involved in the development of aortic inflammation by cell transplantation experiments. Half of the IL-1Ra(-/-) mice developed aortitis at the root of the aorta, with massive infiltration of macrophages and monocytes and loss of elastic lamellae in the aortic media. Left ventricular hypertrophy and mild aortic stenosis were also shown by transthoracic echocardiography. Transplantation of T cells from IL-1Ra(-/-) mice induced aortitis in recipient nu/nu mice. Bone marrow cell transplants from IL-1Ra(-/-) mice also induced aortitis in irradiated wild-type recipient mice. Furthermore, tumor necrosis factor (TNF)-alpha deficiency completely suppressed the development of aortitis in IL-1Ra(-/-) mice, whereas IL-6 deficiency did not affect pathology. CONCLUSIONS: These observations suggest that IL-1Ra deficiency in T cells activates them excessively, resulting in the development of aortitis in IL-1Ra(-/-) mice in a TNF-alpha-dependent manner.

Animals↗
PubMed2005

Antioxidant activities of black and yellow soybeans against low density lipoprotein oxidation.

Several studies have demonstrated that the daily intakes of soy foods were associated with a reduced cardiovascular risk. The aim of our study was to investigate the inhibitory effect of black soybeans on low density lipoprotein (LDL) oxidation in comparison to yellow soybeans. The extract from black soybean had a longer LDL oxidation lag time than that from yellow soybean (205 +/- 16 and 65 +/- 3 min, respectively). When both soybeans were divided into the seed coat and the mixture of the germ and cotyledon, the diluted extract solution from the black soybean seed coat prolonged the lag time significantly more than the original extract of the yellow soybean seed coat. On the other hand, antioxidant effects of the extract from the mixture of germs and cotyledons were similar in both soybeans. Regarding total polyphenol contents, the seed coat of black soybean had a higher polyphenol content than that of yellow soybean (29.0 +/- 0.56 and 0.45 +/- 0.02 mg/g, respectively). Interestingly, the mixture of the germ and cotyledon hydrolyzed by beta-glucosidase in both soybeans showed a stronger inhibitory effect on LDL oxidation than that before being hydrolyzed by beta-glucosidase. These results suggest that black soybeans may be more effective in inhibiting LDL oxidation than yellow soybeans because of total polyphenols contents in its seed coat. In addition, aglycones, which are rich in soybeans fermented or hydrolyzed by beta-glucosidase, may play a crucial role in the prevention of oxidation-related diseases.

Antioxidants↗
PubMed2005

Effect of lipid-lowering therapy with atorvastatin on atherosclerotic aortic plaques detected by noninvasive magnetic resonance imaging.

OBJECTIVES: We sought to elucidate the effects of 20-mg versus 5-mg atorvastatin on thoracic and abdominal aortic plaques. BACKGROUND: Regression of thoracic aortic plaques by simvastatin was demonstrated using magnetic resonance imaging (MRI). However, the effects of different doses of statin have not been assessed. METHODS: Using MRI, we investigated the effects of 20-mg versus 5-mg atorvastatin on thoracic and abdominal aortic plaques in 40 hypercholesterolemic patients who were randomized to receive either dose. Treatment effects were evaluated as changes in vessel wall thickness (VWT) and vessel wall area (VWA) of atherosclerotic lesions from baseline to 12 months of treatment. RESULTS: The 20-mg dose induced a greater low-density lipoprotein (LDL) cholesterol reduction than did the 5-mg dose (-47% vs. -34%, p < 0.001). Although 20 mg and 5 mg reduced C-reactive protein (CRP) levels (-47% and -28%), the degree of CRP reduction did not differ between the two doses. The 20-mg dose reduced VWT and VWA of thoracic aortic plaques (-12% and -18%, p < 0.001), whereas 5 mg did not (+1% and +4%). Regarding abdominal aortic plaques, even 20 mg could not reduce VWT or VWA (-1% and +3%), but instead progression was observed with 5-mg treatment (+5% and +12%, p < 0.01). Notably, the degree of plaque regression in thoracic aorta correlated with LDL cholesterol (r = 0.64) and CRP (r = 0.49) reductions. Although changes in abdominal aortic plaques only weakly correlated with LDL cholesterol reduction (r = 0.34), they correlated with age (r = 0.41). CONCLUSIONS: One-year 20-mg atorvastatin treatment induced regression of thoracic aortic plaques with marked LDL cholesterol reduction, whereas it resulted in only retardation of plaque progression in abdominal aorta. Thoracic and abdominal aortic plaques may have different susceptibilities to lipid lowering.

Aged↗
PubMed2005

Effect of cevimeline on salivary components in patients with Sjögren syndrome.

The aim of this study is to clarify the effects of cevimeline on various components in human saliva, such as immunoglobulin A (IgA), lysozyme, alpha-amylase and squamous cell carcinoma (SCC) antigen. Twelve female patients with Sjögren syndrome (SS) and 14 healthy women were enrolled. After the first saliva collection, one capsule (30 mg) of cevimeline was administered to each subject. Saliva was collected again after 90 min. The salivary flow rate and concentration of each component were measured. In both groups the salivary flow rate and amylase concentration were significantly increased by cevimeline. The lysozyme and IgA concentrations did not change significantly in both groups. The SCC antigen concentration did not change significantly in the SS group, but it decreased significantly in the control group. The secretion rates of amylase and IgA showed significant increases in both groups. The secretion rate of lysozyme significantly increased only in the control group, while the secretion rate of SCC significantly increased only in the SS group. Cevimeline augments not only the salivary flow rate but also the secretion rate of some digestive and/or defense factors from infections. It may be beneficial for SS patients to continue taking cevimeline to prevent oral infections, and other serious sequelae.

Antigens, Neoplasm↗
PubMed2005

Levels of matrix metalloproteinase-1 in patients with and without coronary artery disease and relation to complex and noncomplex coronary plaques.

We investigated the association between serum levels of matrix metalloproteinase-1 (MMP-1) and coronary artery disease (CAD) in 185 patients who underwent elective coronary angiography. MMP-1 levels did not differ between patients who had CAD and those who did not and did not correlate with the number of >50% stenotic vessels or segments, but MMP-1 levels were significantly higher in patients who had CAD and complex coronary lesions than in those who did not have such lesions and those who did not have CAD. High serum levels of MMP-1 were associated with the presence of complex lesions in patients who had CAD.

Aged↗
PubMed2005

Associations of plasma C-reactive protein levels with the presence and extent of coronary stenosis in patients with stable coronary artery disease.

Prospective studies showed plasma high sensitivity C-reactive protein (hsCRP) levels to be a powerful predictor of cardiac events. However, the association between hsCRP levels and the extent of coronary stenosis in patients with coronary artery disease (CAD) remains controversial. We investigated the association between hsCRP levels and the extent of coronary stenosis in 273 patients undergoing elective coronary angiography. Plasma hsCRP levels were higher in patients with CAD than in those without CAD (0.70 mg/l versus 0.56 mg/l, P < 0.02), but hsCRP levels did not correlate with the number of >50% stenotic vessels and were not a significant factor for CAD. However, after the exclusion of 76 patients taking statins, a step-wise increase in hsCRP levels was found depending on the number of >50% stenotic vessels: 0.50 in CAD(-), 0.68 in 1-vessel, 0.77 in 2-vessel, and 0.88 mg/l in 3-vessel disease (P < 0.01). The hsCRP levels also correlated with the numbers of >50% and >25% stenotic segments (r = 0.30 and 0.32, P < 0.001). Multivariate analysis revealed the hsCRP levels to be a significant factor for CAD. Thus, after the exclusion of patients with statins, plasma hsCRP levels were found to be associated with the presence and extent of coronary stenosis in patients with stable CAD.

Aged↗
PubMed2005

Effect of anastrozole and tamoxifen on lipid metabolism in Japanese postmenopausal women with early breast cancer.

Endocrine therapies that profoundly decrease estrogen levels potentially have a detrimental effect on the cardiovascular system. This study evaluated the effect on lipid metabolism of one such agent, the new generation aromatase inhibitor anastrozole, compared with tamoxifen, when used as adjuvant treatment in postmenopausal Japanese women with early breast cancer. All patients had completed primary surgery and were randomized to anastrozole 1 mg once daily (n=22) or tamoxifen 20 mg once daily (n=22). Anastrozole significantly reduced levels of triglycerides and remnant-like particle cholesterol, whereas tamoxifen significantly increased these. Activity of lipoprotein lipase and levels of high-density lipoprotein cholesterol significantly increased after anastrozole treatment. In contrast, activity of hepatic triglyceride lipase, also a key enzyme of triglyceride metabolism, significantly decreased following treatment with tamoxifen. We thus conclude that in our study anastrozole had a beneficial effect on lipid profiles of postmenopausal women with early breast cancer after 12 weeks of treatment.

Aged↗
PubMed2005

Green tea consumption and serum malondialdehyde-modified LDL concentrations in healthy subjects.

OBJECTIVE: Green tea was shown to inhibit LDL oxidation, platelet aggregation, and matrix metalloproteinases (MMPs) activities in vitro. We tried to elucidate whether or not green tea consumption may have these effects in vivo, which may be protective against atherosclerotic disease. METHODS: We measured serum malondialdehyde-modified LDL (MDA-LDL) concentrations and urine 8-epi-prostaglandin (PG) F(2alpha) in 22 healthy male nonsmokers. They drank 7 cups/day of water for 2 weeks and drank 7 cups/day of green tea for the next 2 weeks. Regarding platelet aggregation, plasma thromboxane B(2) (TXB(2)) and 6-keto-PGF(1alpha) concentrations and ex vivo platelet aggregation were evaluated. Plasma MMP-2 and -9 concentrations were also measured. RESULTS: Of the 22 subjects, 20 had been in the habit of drinking green tea before the study. Plasma catechins concentrations significantly decreased at the end of the water period and then increased at the end of the green tea period. Although no change in plasma LDL-cholesterol concentrations (110 +/- 33 vs. 113 +/- 28 mg/dL, p = NS) was found, MDA-LDL concentrations (84 +/- 45 vs. 76 +/- 40 IU/L, p < 0.05) and the ratio of MDA-LDL/LDL-cholesterol (0.74 +/- 0.21 vs. 0.65 +/- 0.20, p < 0.02) significantly decreased at the end of the green tea period. However, no significant changes were observed in urine 8-epi-PGF(2alpha) concentrations, in platelet aggregation, nor in plasma TXB(2), 6-keto-PGF(1alpha) or MMP concentrations. CONCLUSION: Daily consumption of green tea decreased serum MDA-LDL concentrations, but it had no significant effects on platelet aggregation, platelet TX production or plasma MMPs concentrations. Our results suggest that green tea consumption may inhibit LDL oxidation in vivo.

Adult↗
PubMed2005

Quantitative analysis for soluble elastin in circulation and cell culture fluids using monoclonal antibody-based sandwich immunoassay.

We have newly established 3 distinct murine monoclonal antibodies (MoAbs) against human soluble elastin by using chemically denatured immunogen isolated from human aorta; they are designated as HASG-2, HASG-30, and HASG-61-1. All of these MoAbs were highly reactive with soluble forms of native elastin in normal human serum. HASG-2 and HASG-61-1 MoAbs can recognize soluble bovine elastin as well as human antigen, but HASG-30 cannot. The sandwich enzyme-linked immunosorbent assay (ELISA) for human soluble elastin was developed with HASG-61-1 labeled with peroxidase and HASG-30 immobilized on the microplates. The circulating levels of soluble elastin in human healthy subjects (mean +/- SD; 42.9 +/- 19.9ng/mL; n = 85) could be measured with full accuracy and reproducibility, and gradually increased with aging. The positive correlation between the levels and ages was statistically significant (r = 0.581, p < 0.0001). In addition, we could also determine the concentration of tropoelastin secreted from cultured human dermal fibroblasts accurately by this ELISA. This simple assay can be utilized for the routine clinical laboratory screening of patients with arteriosclerotic vascular diseases or to accurately determine the concentrations of tropoelastin secreted from cultured human cells.

Adult↗
PubMed2005

Plasma matrix metalloproteinase-8 concentrations are associated with the presence and severity of coronary artery disease.

BACKGROUND: Interstitial collagen, especially type I, is a major component of atherosclerotic plaques and the matrix metalloproteinases (MMP) 1, 8 and 13 can initiate collagen breakdown. MMP-8 degrades type I collagen preferentially and more potently than MMP-1 or MMP-13. Although MMP-8 was thought to be produced only by neutrophils, it was recently reported to also be produced by endothelial cells, smooth muscle cells and macrophages in plaques. METHODS AND RESULTS: Plasma MMP-8 concentrations were measured in 250 patients undergoing coronary angiography for coronary artery disease (CAD: >50% stenosis), which was found in 181 patients, of whom 69 had 1-vessel, 66 had 2-vessel, and 46 had 3-vessel disease. Compared with 69 patients without CAD, the 181 with CAD had higher MMP-8 concentrations (3.5 vs 3.0 ng/ml, p < 0.001). There was a stepwise increase in MMP-8 concentration depending on the number of stenotic vessels: 3.2 in 1-vessel, 3.6 in 2-vessel, and 4.3 ng/ml in 3-vessel disease (p < 0.001). Multivariate analysis showed that MMP-8 concentration was independently associated with CAD. The odds ratio for CAD was 1.22 (95%confidence interval = 1.07-1.39) for a 1 ng/ml increase in MMP-8 concentration. CONCLUSIONS: Plasma MMP-8 concentration is associated with the presence and severity of CAD.

Aged↗
PubMed2005

Polymorphism of the 3'-untranslated region of interleukin-12 p40 gene is not associated with the presence or severity of coronary artery disease.

BACKGROUND: Interleukin (IL)-12 is thought to play an important role in the development of atherosclerosis and recently, polymorphism of the 3'-untranslated region of the IL-12 p40 gene (A1188C) was reported to be associated with diabetes and multiple sclerosis. However, the association between this genetic polymorphism and coronary artery disease (CAD) has not been studied. METHODS AND RESULTS: The frequency of this polymorphism was investigated in 555 patients undergoing coronary angiography: 395 had CAD, of whom 161 also had a myocardial infarction (MI). With regard to the IL-12 p40 polymorphism, 125 had the A/A, 268 had the A/C, and 162 had the C/C genotype. The prevalence of CAD did not differ among the groups (71%, 73%, and 69%, respectively; p= NS). The prevalence of MI was also similar among the groups (28%, 27%, and 33%, respectively; p= NS). Moreover, the number of >50% stenotic vessels, >50% stenotic segments, and < or =50% stenotic segments did not differ among the 3 groups. CONCLUSIONS: Polymorphism of IL-12 p40 gene was not found to be associated with the presence or severity of CAD, suggesting that it does not play an important role in the development of this disease.

Aged↗
PubMed2005

Characterization of the expression of TLR2 (toll-like receptor 2) and TLR4 on circulating monocytes in coronary artery disease.

TLRs are receptors involved in the recognition of pathogens by the innate immune system, and TLR2 and TLR4 play important roles in the activation of monocytes. A total of 105 consecutive patients who underwent coronary angiography comprised of 46 with stable effort angina (SA), 41 with unstable angina (UA), and 18 with no significant CAD (CNT) were enrolled. The baseline expression levels of TLR2 and TLR4 on monocytes in peripheral blood mononuclear cells (PBMCs) were determined by flow-cytometric analysis. Since TLR2 expression has been reported to be regulated by TLR4 signaling, we cultured PBMCs with or without lipopolysaccharide (LPS, 1 microg/ml). At baseline, TLR4 levels (mean of fluorescence intensity ) in SA (145 +/- 58, p < 0.05) and UA (164 +/- 65, p < 0.01) were higher than those in CNT (107 +/- 37). As for TLR2, levels were higher in UA (108 +/- 36, p < 0.05) than in SA (94 +/- 18) and CNT (87 +/- 22). After stimulation with LPS, TLR2 levels increased in SA but decreased in UA. In conclusions, TLR4 levels increased in both SA and UA. Monocytes in UA were characterized by elevated TLR2 levels and unresponsiveness of the TLR2 levels to TLR4 stimulation.

Aged↗
PubMed2004

Deficiency of interleukin-1 receptor antagonist deteriorates fatty liver and cholesterol metabolism in hypercholesterolemic mice.

Although the anti-inflammatory effect of interleukin-1 (IL-1) receptor antagonist (IL-1Ra) has been described, the contribution of this cytokine to cholesterol metabolism remains unclear. Our aim was to ascertain whether deficiency of IL-1Ra deteriorates cholesterol metabolism upon consumption of an atherogenic diet. IL-1Ra-deficient mice (IL-1Ra(-/-)) showed severe fatty liver and portal fibrosis containing many inflammatory cells following 20 weeks of an atherogenic diet when compared with wild type (WT) mice. Expectedly, the levels of total cholesterol in IL-1Ra(-/-) mice were significantly increased, and the start of lipid accumulation in liver was observed earlier when compared with WT mice. Real-time PCR analysis revealed that IL-1Ra(-/-) mice failed to induce mRNA expression of cholesterol 7alpha-hydroxylase, which is the rate-limiting enzyme in bile acid synthesis, with concurrent up-regulation of small heterodimer partner 1 mRNA expression. Indeed, IL-1Ra(-/-) mice showed markedly decreased bile acid excretion, which is elevated in WT mice to maintain cholesterol level under atherogenic diet feeding. Therefore, we conclude that the lack of IL-1Ra deteriorates cholesterol homeostasis under atherogenic diet-induced inflammation.

Animals↗
PubMed2004

Lack of interleukin-1 receptor antagonist modulates plaque composition in apolipoprotein E-deficient mice.

OBJECTIVE: Interleukin (IL)-1 plays an important role in atherosclerosis. IL-1 receptor antagonist (IL-1Ra) is an endogenous inhibitor of IL-1. However, the role of IL-1Ra in the development of atherosclerosis is poorly understood. METHODS AND RESULTS: Mice that lacked IL-1Ra (IL-1Ra-/-) were crossed with apolipoprotein E-deficient (E-/-) mice and formation of atherosclerotic lesions was analyzed after 16 weeks or 32 weeks consumption of a normal chow diet. This study focused on the comparison of atherosclerotic lesion between IL-1Ra+/+/apoE-/- (n=12) and IL-1Ra(+/-)/apoE-/- mice (n=12), because of the significantly leaner phenotype in IL-1Ra-/-/apoE-/- mice compared with the others. Interestingly, atherosclerotic lesion size in IL-1Ra+/-/apoE-/- mice at age 16 weeks was significantly increased (30%) compared with IL-1Ra+/+/apoE-/- mice (P<0.05). At 32 weeks, the differences of lesion size between these mice failed to achieve statistical significance. However, immunostaining demonstrated an 86% (P<0.0001) increase in the MOMA-2-stained lesion area of IL-1Ra+/-/apoE-/- mice. In addition, alpha-actin staining in these lesions was significantly decreased (-15%) compared with those in IL-1Ra+/+/apoE-/- mice (P<0.05). CONCLUSIONS: These results suggest an important role of IL-1Ra in the suppression of lesion development during early atherogenesis and furthermore indicate its role in the modulation of plaque composition.

Animals↗