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Biomedical subjects

H Yasue

Publications and source records attributed to H Yasue.

At least 91 records · Page 5Linked to original sources

Improvement of endothelial function and insulin sensitivity with vitamin C in patients with coronary spastic angina: possible role of reactive oxygen species.

OBJECTIVES: This study was designed to examine the effect of antioxidant supplementation on the endothelial function and insulin sensitivity in patients with coronary spastic angina (CSA). BACKGROUND: Insulin resistance may play a key role in coronary heart disease, and there is a possible link between acetylcholine-induced coronary vasoconstriction and hyperinsulinemia in patients with CSA. Endothelial dysfunction is present in the systemic arteries in CSA patients, and reactive oxygen species may cause inactivation of nitric oxide in these patients. METHODS: We measured flow-mediated dilation of the brachial artery using ultrasound technique in 22 patients with CSA and 20 control subjects. We also evaluated glucose tolerance using a 75-g oral glucose tolerance test and insulin sensitivity using steady-state plasma glucose (SSPG) methods in the same patients. RESULTS: The incidence of impaired glucose tolerance was higher in the CSA group than in the control group. Vitamin C infusion augmented flow-mediated dilation and decreased SSPG levels in the CSA group (from 3.27 +/- 0.77% to 7.00 +/- 0.59% [p < 0.001 by analysis of variance (ANOVA)] and from 177.3 +/- 13.3 to 143.1 +/- 14.9 mg/dl [p = 0.047 by ANOVA], respectively) but not in the control group (from 6.47 +/- 0.66% to 6.80 +/- 0.60% and from 119.8 +/- 11.7 mg/dl to 118.1 +/- 11.3 mg/dl, respectively). The steady-state plasma insulin levels were not affected by vitamin C infusion in either group. CONCLUSIONS: Vitamin C improves both endothelial function and insulin sensitivity in patients with CSA. Thus, reactive oxygen species and/or decreased nitric oxide bioactivity may play an important role in the genesis of both endothelial dysfunction and insulin resistance in patients with CSA.

Angina, Unstable↗

Diffuse intimal thickening of coronary arteries in patients with coronary spastic angina.

OBJECTIVES: The purpose of this study was to evaluate the extent of atherosclerotic changes in angiographically normal coronary arteries using intravascular ultrasound (IVUS) technique in patients with coronary spastic angina. BACKGROUND: Nitric oxide activity was shown to be decreased in coronary arteries of patients with coronary spastic angina (CSA). Decrease in nitric oxide causes arterial intimal hyperplasia or thickening. However, it remains unclear whether intimal thickening is diffusely present in coronary arteries of patients with CSA. METHODS: The IVUS study was performed in 26 patients with CSA and with normal coronary angiograms and in 31 control subjects in whom age and gender was matched with those in patients with CSA. RESULTS: Compared with control subjects, patients with CSA had significantly larger percent intima + media area (%I + M area), intima + media area and maximal intima + media thickness in all of proximal, middle and distal segments (p<0.01, respectively). Lumen area was comparable between these groups. The presence of spasm was the most powerful independent predictor of increase in percent intima + media area, in multiple-regression analysis with the traditional risk factors as covariates. CONCLUSIONS: Intimal thickening existed entirely in a coronary artery in patients with CSA and with normal angiograms, independently of other traditional risk factors. The diffuse intimal thickening in the spasm coronary arteries is intimately related with coronary spasm.

Aged↗

Construction and evaluation of a porcine bacterial artificial chromosome library.

A porcine bacterial artificial chromosome (BAC) library consisting of 103,488 clones has been constructed. The average insert size in the BAC vector was calculated to be 133 kb based on the examination of 189 randomly selected clones, indicating that the library contained 4.4 genome equivalents. The library can be screened by two-step PCR. The first screening step is performed on 22 superpools, each containing 4704 clones (49 x 96 well plates). In the second screening step, 49 plates comprising a superpool are arrayed in a 7 x 7 matrix and 4D-PCR is performed. Screening of the library superpools by PCR for 125 marker sequences selected from different regions of swine genome revealed 123 sequences, indicating that the library is not biased. Subsequent screenings (4D-PCR) were successfully applied for identification of clones containing each marker sequence. This porcine BAC library and the PCR screening system are useful for isolation of genomic DNA fragments containing desired sequences.

Animals↗

Quantitative trait loci (QTL) analysis in a Meishan x Göttingen cross population.

In order to locate the genetic regions in the swine genome that are responsible for economically important traits, a resource population has been constructed by mating two female Meishan pigs with a male Göttingen miniature pig. In subsequent generations, 265 F2 offspring were produced from two F1 males and 19 F1 females. The F2 offspring were scored for eight traits including growth rate, teat number, vertebra number and backfat thickness, and genotyped for 318 genetic markers spanning the swine genome. Least-square analysis revealed quantitative trait loci (QTL) effects for vertebra number on chromosomes 1 and 2; for teat number on chromosomes 1 and 7; for birth weight on chromosome 1; for average daily gain between 4 and 13 weeks of age on chromosomes 9 and 10; for backfat thickness on chromosome 7; and for backskin thickness on chromosome 3.

Animals↗

Interaction on metabolic clearance between A-type and B-type natriuretic peptides in patients with heart failure.

A-type and B-type natriuretic peptides (ANP and BNP) are secreted into the systemic circulation via the coronary sinus. Plasma levels of ANP and BNP at the coronary sinus should directly determine the systemic circulating levels. However, the metabolic clearance of these hormones are dependent on similar systems, natriuretic peptide clearance receptor (NPR-C) and neutral endopeptidase 24.11 (NEP), suggesting a possible interaction between ANP and BNP on metabolic clearance. In this study, we examined the interaction on metabolic clearance in patients with heart failure. We obtained blood samples from the coronary sinus and aortic root in 100 patients with heart failure and 28 control subjects. The difference in ANP and BNP levels between the coronary sinus and the aortic root is reflected partly by the metabolic clearance in the pulmonary circulation. In this study, we examined the possible interaction on metabolic clearance between ANP and BNP using a statistical procedure. The ratio of the level of BNP to ANP (BNP/ANP) was significantly higher in the aortic root than in the coronary sinus at any stage of heart failure. We performed multiple regression analysis using ANP and BNP levels at the coronary sinus as independent variables (X1 and X2, respectively) and the ANP level at the aortic root as a dependent variable (Y). The analysis showed that both X1 and X2 were significant variables in the equation. On the other hand, we performed the same analysis using the BNP level at the aortic root as a dependent variable (Y). The analysis showed that only X2 was a significant variable in the equation. This study suggests that (1) the metabolic clearance in the pulmonary circulation is higher for ANP versus BNP and (2) the amount of ANP cleared in the pulmonary circulation depends on the amount of both ANP and BNP secreted from the heart, whereas the amount of BNP cleared in the pulmonary circulation is dependent solely on the amount of BNP secreted from the heart.

Aorta↗

Increased plasma level of soluble E-selectin in acute myocardial infarction.

BACKGROUND: E-selectin, also known as endothelial cell leukocyte adhesion molecule-1, is a member of the selectin family of adhesion molecules and is expressed on vascular endothelial cells in inflammatory reactions. The induction of surface E-selectin expression by endothelial cells is considered a marker of activation. METHODS AND RESULTS: We examined the plasma soluble E-selectin (sE-selectin) level in 41 patients within 6 hours after the onset of acute myocardial infarction (AMI) and in 37 patients with stable exertional angina and 27 control patients. Blood samples were obtained on admission, after reperfusion therapy, and at 4 hours, 8 hours, 12 hours, 24 hours, 48 hours, 3 days, 5 days, 1 week, and 2 weeks after admission in the AMI group. In this group, 21 patients had a history of prodromal unstable angina before infarction and 20 had sudden onset of infarction. The plasma sE-selectin level (ng/mL) on admission was higher in the AMI group than in the stable exertional angina group and control group (38.5 +/- 3.1 vs 28.5 +/- 1.5, P <.01, 26.0 +/- 1.8, P <.01, respectively). In addition, plasma sE-selectin levels were higher in the patients with AMI with prodromal unstable angina than in those with a sudden onset of infarction on admission (44.7 +/- 5.4 vs 32.0 +/- 2.1, P <.05). The plasma sE-selectin level decreased slowly during the chronic phase both in patients with AMI with prodromal unstable angina (from 44.7 +/- 5.4 to 33.8 +/- 3.4, P <.01) and those with a sudden onset of infarction (from 32.0 +/- 2.1 to 24.9 +/- 2.4, P <.01). CONCLUSIONS: These results suggest that an increase of sE-selectin may reflect enhanced endothelial cell activation in patients with AMI. The higher sE-selectin level in patients with AMI with prodromal unstable angina may have been associated with repeated episodes of myocardial ischemia and reperfusion.

Aged↗

Cell-mediated and humoral immunity and phagocytic ability in chicken Lines divergently selected for serum immunoglobulin M and G levels.

Humoral and cell-mediated immunities and phagocytic ability were examined at the third and fourth generations of selection in two pairs of chicken lines (at 10 wk of age) that were divergently selected for levels of high serum Ig M (HIM), low serum Ig M (LIM), high serum Ig G (HIG), and low serum Ig G (LIG). Cell-mediated immunity was examined by splenomegaly assay at 12 wk of age. At 20 and 23 wk of age, 20 birds from the respective lines were injected Brucella abortus (BA), and blood samples were collected at 7 and 14 d postprimary immunization (PPI) and postsecondary immunization (PSI). Phagocytic ability was measured by carbon clearance assay at 25 and 30 wk of age. The results showed that the LIG line had higher degree of splenomegaly indices than the HIG line in both generations. The HIM and HIG lines had significantly (P < 0.05) higher total antibody titers to BA than their low counterparts. Similarly, mercaptoethanol-resistant (MER) antibody titers to BA, as measured only in the fourth generation, were significantly (P < 0.05) higher in the HIM and HIG lines than their low counterparts. In both generations, the HIM and HIG lines had significantly (P < 0.01) faster carbon clearance ability than the LIM and LIG lines. The results suggest that both pairs of selected lines exhibited divergence in immunocompetence, although they had been selected for serum Ig isotypes.

Animals↗

Insulin resistance and endothelial dysfunction in smokers: effects of vitamin C.

Cigarette smoking impairs endothelial function and is one of the major risk factors for atherosclerosis and coronary heart disease. Insulin resistance is associated with major risk factors for atherosclerosis. We examined the effects of vitamin C on insulin sensitivity and endothelial function by measuring steady-state plasma glucose (SSPG) and flow-mediated dilation (FMD) of the brachial artery. We studied 16 current smokers with normal glucose tolerance, 15 nonsmokers with impaired glucose tolerance (IGT), and 17 nonsmokers with normal glucose tolerance as controls. Both SSPG and FMD were blunted in smokers and nonsmokers with IGT compared with controls. In smokers, vitamin C decreased SSPG (P < 0.01 by ANOVA) with decreasing plasma thiobarbituric acid-reactive substances (TBARS) (P < 0.05 by ANOVA) and improved FMD (P < 0.05 by ANOVA). Furthermore, vitamin C improved both SSPG (P < 0.005 by ANOVA) and FMD (P < 0.05 by ANOVA) in nonsmokers with IGT. SSPG, FMD, or TBARS in controls did not change after vitamin C infusion. There was a significant correlation between SSPG and FMD both in smokers and nonsmokers with IGT, whereas no correlation was observed in controls. In conclusion, both insulin sensitivity and endothelial function were impaired in smokers and nonsmokers with IGT and were improved by vitamin C. Thus increased reactive oxygen species play an important role in the pathogenesis of insulin resistance as well as endothelial dysfunction in smokers and nonsmokers with IGT.

Analysis of Variance↗

Increased blood vascular endothelial growth factor levels in patients with acute myocardial infarction.

Vascular endothelial growth factor (VEGF) is a growth factor for vascular endothelial cells in vitro. The present study was designed to determine whether serum VEGF levels increase in patients with acute myocardial infarction (AMI) compared with patients with stable exertional angina and control subjects, and to examine the serial changes of serum VEGF levels in patients with AMI. We examined serum VEGF levels by using antibody prepared from serum immunized with human VEGF(121). The serum VEGF level (pg/ml) was higher (p < 0. 0001) on admission in the patients with AMI (177 +/- 19) than in those with stable exertional angina (61 +/- 7) and control subjects (62 +/- 6). The serum VEGF level (pg/ml) of the patients with AMI was 177 +/- 19 on admission, 125 +/- 9 on day 3, 137 +/- 11 on day 5, 242 +/- 18 at 1 week, and 258 +/- 22 at 2 weeks after admission. The value was higher on admission than on day 3 after admission (p = 0.014), the values were higher at 1 week and 2 weeks than on admission, on day 3, and 5 (p < 0.01). Furthermore, there were correlations between peak VEGF levels at 1 week or 2 weeks after admission and peak creatine kinase levels. The increase of VEGF on admission in the patients with AMI may be due to the hypoxia of acute myocardial ischemia. The elevation at 1 week and 2 weeks from the onset may cause the development of collateral circulation in relation to the healing of the infarction site.

Aged↗

Hemodynamic and hormonal effects of the angiotensin II antagonist, candesartan cilexetil, in patients with congestive heart failure.

Candesartan cilexetil is a newly synthesized, specific angiotensin II type 1 receptor antagonist. Candesartan cilexetil is a prodrug, and is converted to its active form, candesartan, by the enzyme esterase at the time of intestinal absorption. We conducted a single-dose study to evaluate the effect of candesartan cilexetil on cardiac hemodynamics and hormone response in 13 patients with congestive heart failure. Mean blood pressure did not show any significant change in the patients receiving either 2 or 8 mg. Pulmonary capillary wedge pressure was reduced by 34.9% in the patients given 8 mg of candesartan cilexetil. The cardiac index did not show any significant changes. Total peripheral vascular resistance was reduced in the patients receiving 2 or 8 mg from 1 h after administration, and the tendency to decrease continued until 8 h after administration. Plasma atrial natriuretic peptide levels were reduced by 15.5% 2 h after dosing with 8 mg of candesartan cilexetil. Plasma brain natriuretic peptide levels decreased slightly after dosing with candesartan cilexetil. Administration of candesartan cilexetil reduces cardiac preload and afterload and is expected to be useful for the treatment of congestive heart failure.

Administration, Oral↗

Lysophosphatidylcholine induces urokinase-type plasminogen activator and its receptor in human macrophages partly through redox-sensitive pathway.

Urokinase-type plasminogen activator (uPA) and its cell surface receptor (uPAR) have been shown to be expressed in macrophages in atherosclerotic arterial walls, but the regulatory mechanisms of their expression remain unclear. The present study was performed to examine the effects of lysophosphatidylcholine (lysoPC), an important atherogenic lipid, on the expression of uPA and uPAR in human monocyte-derived macrophages. LysoPC upregulated the mRNA expression of uPA and uPAR, and it increased the protein expression of uPA in the culture medium and bound to the cell surface and of uPAR in the particulate fraction of the cells. LysoPC significantly increased the binding of the amino-terminal fragment of uPA to the treated cells and the cell-associated plasminogen activator activity. LysoPC stimulated superoxide anion production and increased intracellular oxidant levels in the cells. The combined incubation with reduced glutathione diethyl ester or N-acetylcysteine, antioxidants, suppressed the upregulation of uPA and uPAR mRNA and the increase in plasminogen activator activity by lysoPC. uPA and uPAR mRNA expression was also induced by the incubation with xanthine and xanthine oxidase, a superoxide anion-generating system. The results suggest that lysoPC increased the expression of uPA and uPAR and their functional activities in human monocyte-derived macrophages, at least in part through a redox-sensitive mechanism. This coordinate increase in the expression of uPA and uPAR in human macrophages by lysoPC could play an important role in plaque formation and disruption, arterial remodeling, and angiogenesis in atherosclerotic arterial walls.

Acetylcysteine↗

The plasma levels of dehydroepiandrosterone sulfate are decreased in patients with chronic heart failure in proportion to the severity.

Dehydroepiandrosterone sulfate (DHEAS) is the major secretory steroid of the human adrenal glands. The secretion of DHEAS decreases with aging. The incidence of heart failure also rises in the elderly population. We measured the plasma levels of DHEAS and cortisol in 49 patients with chronic heart failure (CHF) and 32 age-matched controls and assessed its relation to plasma levels of A-type natriuretic peptide and B-type natriuretic peptide, biochemical markers of heart failure. Plasma levels of DHEAS were significantly lower in patients with CHF than in controls, whereas there was no significant difference in plasma levels of cortisol between the two groups. In stepwise regression analysis, the plasma level of DHEAS was significantly and independently correlated with age (beta = -0.451; P < 0.0001) and the plasma level of B-type natriuretic peptide (beta = -0.338; P < 0.001), and the plasma cortisol/DHEAS ratio was significantly and independently correlated with the plasma levels of A-type natriuretic peptide (beta = 0.598; P < 0.0001) and thiobarbituric acid-reactive substances (a marker of oxidative stress; beta = 0.252; P < 0.01) and age (beta = 0.171; P < 0.05). These results indicate that the plasma levels of DHEAS are decreased in patients with CHF in proportion to its severity and that oxidative stress is associated with decreased levels of DHEAS in patients with CHF.

Adult↗

Elevated levels of soluble intercellular adhesion molecule-1 in the coronary circulation of patients with coronary organic stenosis and spasm.

The cell surface expression of intercellular adhesion molecule-1 (ICAM-1) is upregulated following activation during inflammatory responses, mediating both cell migration and activation. The involvement of inflammation in unstable angina is suggested by the presence of activated circulating leukocytes. To examine whether plasma soluble ICAM-1 (sICAM-1) levels increase in the coronary circulation of patients with coronary organic stenosis and coronary spasm, plasma sICAM-1 levels were measured in the coronary sinus (CS) and the aortic root (Ao) simultaneously in 10 patients with 90% or more coronary narrowing and coronary spasm (coronary spastic angina (CSA) with organic stenosis), in 11 patients with coronary spasm and no significant coronary narrowing (CSA without organic stenosis), in 16 patients with stable exertional angina, and in 13 control subjects. The plasma sICAM-1 levels (ng/ml) in the CS increased in CSA with organic stenosis (230+/-26) as compared with CSA without organic stenosis (158+/-14), stable exertional angina (130+/-9) and control subjects (121+/-10) (p<0.01). The levels in the Ao also increased in CSA with organic stenosis (208+/-24) as compared with CSA without organic stenosis (149+/-13), stable exertional angina (130+/-11) and control subjects (121+/-10) (p<0.01). Furthermore, the plasma sICAM-1 levels were higher in the CS than in the Ao only in CSA with organic stenosis. These results suggest that activation of leukocytes occurs through the induction of ICAM-1 in the coronary circulation in the patients with CSA with organic stenosis.

Aged↗

Increased rate of formation of small-sized platelet aggregates in patients with acute coronary syndromes.

Coronary thrombosis has been implicated in the pathogenesis of acute coronary syndromes, and platelet activation plays a pivotal role in the pathogenesis of coronary thrombus. A new platelet aggregometer using a laserlight scattering beam was trialled for assessment of platelet aggregation. Platelet aggregability, especially small-sized platelet aggregates, was investigated on admission using the laser-light scattering method and again after treatment in 23 patients with acute coronary syndromes. The platelet aggregability in 14 patients with stable exertional angina and in 14 control subjects was also examined. On admission, the number of small- and medium-sized platelet aggregates in the acute coronary syndromes group was significantly greater than in the stable exertional angina group or control group. However, the number of large-sized platelet aggregates on admission was not increased in the acute coronary syndromes group. Furthermore, the number of small- and medium-sized platelet aggregates decreased significantly after treatment in the acute coronary syndromes group. The increased number of small-sized platelet aggregates may sensitively reflect attacks of thrombosis in patients suffering acute coronary syndromes.

Acute Disease↗

Increased plasma antigen levels of monocyte chemoattractant protein-1 in patients with restenosis after percutaneous transluminal coronary angioplasty.

Monocyte chemoattractant protein-1 (MCP-1) plays an important role in the progression of atherosclerosis in coronary arteries. To examine whether or not plasma antigen levels of MCP-1 are related to restenosis after percutaneous transluminal coronary angioplasty (PTCA), the plasma antigen levels of MCP-1 were measured by enzyme-linked immunosorbent assay (pg/ml) before, 24 and 48 h, and 3 months after elective PTCA for stable exertional angina performed between June 1997 and March 1998. Restenosis was defined as recurrence of stenosis greater than 50% of the diameter in the dilated segment at 3-month follow-up angiography. There were no differences in plasma MCP-1 antigen levels before and at 24 h after PTCA between restenosis (R; n=27) and no-restenosis (N; n=43) groups (R vs N: 633+/-35 vs 589+/-34, and 669+/-41 vs 575+/-36 pg/ml before and at 24 h after PTCA, respectively), but plasma MCP-1 antigen levels were higher at 48 h and 3 months after PTCA in the R than in N group (R vs N: 678+/-41 vs 558+/-35, and 735+/-35 vs 571+/-32 pg/ml at 48 h and 3 months after PTCA, respectively). These data suggest that the MCP-1 production and macrophage accumulation in the balloon-injured site is partially associated with restenosis after PTCA.

Aged↗

Lack of association between T-786-->C mutation in the 5'-flanking region of the endothelial nitric oxide synthase gene and essential hypertension.

Accumulating evidence strongly suggests that an alteration in nitric oxide metabolism is involved in the pathogenesis of hypertension. We recently found 2 polymorphisms in the endothelial nitric oxide synthase (eNOS) gene, a Glu298Asp missense variant in exon 7 and a T-786-->C variant in the 5'-flanking region, which are not linked to each other. In our previous reports, we showed a positive association between the Glu298Asp variant and essential hypertension, myocardial infarction, and coronary spastic angina. We also revealed that the T-786-->C variant is strongly associated with coronary spastic angina and leads to the reduction of the eNOS gene promoter activity. To further investigate the genetic involvement of the eNOS gene in essential hypertension, we examined the frequency of T-786-->C variant in two independent populations of persons with essential hypertension in Kyoto (n=215) and Kumamoto (n=186) and compared the frequency with that in each age- and gender-matched control (233 controls in Kyoto and 223 controls in Kumamoto). In both groups, the frequency of T-786-->C variant was similar in patients with hypertension and normal controls. In conclusion, the T-786-->C variant was not positively associated with essential hypertension. Given the evidence of positive association of another polymorphism in the eNOS gene, the Glu298Asp polymorphism, with essential hypertension, special attention will be required to interpret the results of a case-control study for genetic risk factors.

Adult↗

Cloning and chromosomal assignment of the porcine interleukin-2 receptor alpha (IL-2Ralpha) gene.

Porcine genomic DNA encoding a 55 kDa subunit of interleukin-2 receptor (IL-2R), which is termed alpha chain (IL-2Ralpha), was cloned by repeated plaque hybridization using IL-2Ralpha cDNA as a probe. Two different lambda phage clones, one of which encoded exon 1 and the 5'-upstream flanking region of IL-2Ralpha gene and another encoded the sequence from exon 2 to exon 8, were isolated. By analysis of the 5'-upstream region of the gene, putative binding motifs for transcription factors such as GATA family proteins, Ikaros, NF-kappaB, NF-IL2Ralpha and SRF, were found as described in human, murine and bovine genes. Two additional motifs for STAT4 binding were also found in this region. Moreover, using the FISH technique, we assigned the porcine IL-2Ralpha locus to the distal end of the long arm of chromosome 10 (10q6-qter) where the vimentin gene had been assigned nearby.

Animals↗

Rapid change of platelet aggregability in acute hyperglycemia. Detection by a novel laser-light scattering method.

We examined the alteration of platelet aggregability in acute hyperglycemia during 75-gram oral glucose tolerance tests (OGTT). Twenty subjects underwent 75-gram OGTT and venous blood samples were obtained before (0 min), 60, 120 and 180 min postload. Platelet aggregability shown as the number of small platelet aggregates was measured with a novel laser-light scattering (LS) method. Platelet aggregability increased in parallel with both glucose and immunoreactive insulin (IRI) levels. The number of mean small aggregates at 60 min (12.30 +/- 1.10 X 10(4)) was significantly higher than the one at 0 min (8.32 +/- 0.88 x 10(4), p <0.001), 120 min (10.63 +/- 0.98 x 10(4), p <0.05) and 180 min (8.28 +/- 0.84 x 104, p <0.001) (mean +/- SEM). Small aggregates correlated positively with plasma glucose levels at 60 min postload (r = 0.67, p = 0.001) while not with IRI. It might be important to suppress transient hyperglycemia for preventing the onset of acute coronary syndromes that could be closely related to platelet hyperaggregability.

Acute Disease↗