Biomedical subjects

Takeshi Hibino

Publications and source records attributed to Takeshi Hibino.

9 recordsLinked to original sources

PubMed2007

Association of gene polymorphisms with myocardial infarction in individuals with or without conventional coronary risk factors.

The purpose of the present study was to assess the genetic risk for myocardial infarction (MI) in individuals with or without conventional coronary risk factors and thereby to contribute to the personalized prevention of MI in such individuals. The study population comprised 3483 unrelated Japanese individuals (1913 men, 1570 women). The 1192 subjects with MI (926 men, 266 women) and 2291 controls (987 men, 1304 women) either had or did not have conventional coronary risk factors, including hypertension, hypercholesterolemia, and diabetes mellitus. The genotypes for 164 polymorphisms of 137 candidate genes were determined by a method that combines the polymerase chain reaction and sequence-specific oligonucleotide probes with suspension array technology. Multivariable logistic regression analysis and a stepwise forward selection procedure revealed that nine different polymorphisms were significantly (P<0.005) associated with MI among individuals with or without hypertension, hypercholesterolemia, or diabetes mellitus: 1018Cright curved arrow T of GP1BA, -108/3Gright curved arrow 4G of IPF1, 677Cright curved arrow T of MTHFR, and Gright curved arrow A of UTS2 in hypertensive individuals; 2445Gright curved arrow A of FABP2, -108/3Gright curved arrow 4G of IPF1, 677Cright curved arrow T of MTHFR, -11,377Cright curved arrow G of ACDC, Aright curved arrow G of AKAP10, 11,496Gright curved arrow A of F7, and 46Cright curved arrow T of F12 in individuals without hypercholesterolemia; 2445Gright curved arrow A of FABP2 in diabetic individuals; and -108/3Gright curved arrow 4G of IPF1 in nondiabetic individuals. Polymorphisms associated with MI may thus differ among individuals with different conventional coronary risk factors. Stratification of subjects on the basis of such risk factors may thus be important in order to achieve personalized prevention of MI with the use of genetic information.

Case-Control Studies↗

PubMed2006

Diagnostic accuracy of cardiac markers for myocardial damage after radiofrequency catheter ablation.

AIMS: This study compares serum markers of myocardial damage incurred during radiofrequency catheter ablation (RFCA). METHODS AND RESULTS: Blood was sampled from 34 patients with atrial flutter (n = 16), atrioventricular nodal reentrant tachycardia (AVNRT; n = 13), and Wolff-Parkinson-White syndrome (WPW; n = 5) to measure creatine kinase MB subfraction (CK-MB), human heart-type fatty acid protein (h-FABP), and cardiac troponin T (cTnT) values at baseline and after RFCA. The controls comprised 12 patients without significant elevation of all myocardial markers during electrophysiological study (EPS) without RFCA. h-FABP values did not elevate significantly, whereas CK-MB and cTnT demonstrated significant change after RFCA (P < 0.001). Neither peak h-FABP nor CK-MB correlated with following RFCA parameters: delivery duration, number of RFCA discharges, and cumulative RFCA energy. In contrast, correlations were significant between mean peak values of cTnT and these RFCA parameters (all P < 0.05). The sensitivity (71.6%) and specificity (35.6%) of h-FABP were inferior to those of cTnT (93.3% and 89.8%, respectively). CONCLUSION: h-FABP is an insensitive and less specific marker of myocardial damage in RFCA much along the lines of CK-MB and when compared with the proven accuracy of cTnT.

Adult↗

PubMed2006

Prediction of genetic risk for metabolic syndrome.

OBJECTIVES: The aim of the study was to identify gene polymorphisms that confer susceptibility to metabolic syndrome in order to allow reliable assessment of genetic risk for this condition. METHODS AND RESULTS: The study population comprised 1788 unrelated Japanese individuals (1033 men, 755 women), including 1017 subjects with metabolic syndrome (634 men, 383 women) and 771 controls (399 men, 372 women). The genotypes for 158 polymorphisms of 133 candidate genes were determined with a method that combines the polymerase chain reaction and sequence-specific oligonucleotide probes with suspension array technology. Multivariable logistic regression analysis with adjustment for age, sex, and the prevalence of smoking revealed that the -1131T-->C polymorphism of the apolipoprotein A-V gene (APOA5) was significantly associated with the prevalence of metabolic syndrome, with the C allele representing a risk factor for this condition. A stepwise forward selection procedure demonstrated that APOA5 genotype (CC+TC versus TT) significantly affected the prevalence of metabolic syndrome. The C allele of this polymorphism was associated with an increased serum concentration of triglycerides and a decreased concentration of HDL-cholesterol. CONCLUSIONS: Genotype for APOA5 may prove reliable for assessment of genetic risk for metabolic syndrome.

Aged↗

PubMed2006

Assessment of the genetic component of hypertension.

BACKGROUND: Although genetic epidemiologic studies have suggested that several genetic variants increase the risk for hypertension, the genes that underlie genetic susceptibility to this condition remain to be identified definitively. We have now performed a large-scale association study to identify gene polymorphisms for reliable assessment of the genetic component of hypertension. METHODS: The study population comprised 4853 unrelated Japanese individuals, including 2818 subjects with hypertension (1677 men, 1141 women) and 2035 controls (1011 men, 1024 women). The genotypes for 150 polymorphisms of 128 candidate genes were determined with a method that combines the polymerase chain reaction and sequence-specific oligonucleotide probes with suspension array technology. RESULTS: Multivariable logistic regression analysis with adjustment for age, sex, body mass index, and the prevalence of smoking revealed that four polymorphisms (1648G-->A in ITGA2, -30G-->A in GCK, A-->G in SAH, and 1117C-->A in PTGIS) were significantly (P < .01) associated with hypertension. A stepwise forward selection procedure demonstrated that ITGA2, GCK, and PTGIS genotypes significantly affected the prevalence of hypertension. Combined genotype analysis of these polymorphisms yielded a lowest odds ratio of 0.47 for the genotypes of AA or AG for ITGA2, GA or AA for GCK, and CC for PTGIS, which were present in 1.1% and 2.0% of hypertensive and control individuals, respectively. CONCLUSIONS: These results suggest that the genotypes for ITGA2, GCK, and PTGIS may prove reliable for the assessment of the genetic component of hypertension. Determination of the combined genotypes for these genes may contribute to personalized prevention of this condition.

Aged↗

PubMed2006

DNA secondary structure forming at minisatellite repeat unit sequences.

The lengths of simple repeat sequences are generally unstable or polymorphic; that is, they are highly variable with respect to the numbers of tandem repeats. To determine the structural features that cause such variability, we examined a minisatellite DNA isolated from the yellow fin sea bream Acanthopagrus latus. Electrophoresis, CD spectra, and calorimetric analyses of oligodeoxyribonucleotides comprised of the minisatellite repeat unit suggest a stable secondary structure is formed within the repeat unit.

Animals↗

PubMed2006

Assessment of genetic risk for myocardial infarction.

Although lifestyle and environmental factors influence the prevalence of myocardial infarction, genetic epidemiological studies have suggested that several genetic variants increase the risk for this condition. We have performed a large-scale association study to identify gene polymorphisms for reliable assessment of the genetic risk of myocardial infarction. The study population comprised 3,483 unrelated Japanese individuals (1,913 men; 1,570 women), including 1,192 subjects with myocardial infarction and 2,291 controls. The genotypes for 164 polymorphisms of 137 candidate genes were determined with an oligonucleotide ligation assay based on analysis of fluorescent microspheres with suspension array technology. Multivariable logistic regression analysis with adjustment for age, sex, body mass index, and the prevalence of smoking, hypertension, diabetes mellitus, and hypercholesterolemia revealed that the 677C-->T (Ala222Val) polymorphism of MTHFR, the 1595C-->G (Ser447Stop) polymorphism of LPL, and the -108/3G-->4G polymorphism of IPF1 were significantly associated with the prevalence of myocardial infarction. A stepwise forward selection procedure demonstrated that IPF1, MTHFR, and LPL genotypes significantly affected the prevalence of myocardial infarction. Combined genotype analysis of these polymorphisms yielded a maximum odds ratio of 2.54 for the combined genotype of TT for MTHFR, CC for LPL, and 3G3G for IPF1. The genotypes for MTHFR, LPL, and IPF1 may prove reliable for assessment of genetic risk for myocardial infarction. Determination of the combined genotype for these genes may contribute to primary, personalized prevention of this condition.

Aged↗

PubMed2005

Nonfixed relationship of the Michaelis constant and maximum velocity with their corresponding rate constants.

The Michaelis constant (K(m)) and V(mas) (E0k(cat)) values for two mutant sets of enzymes were studied from the viewpoint of their definition in a rapid equilibrium reaction model and in a steady state reaction model. The "AMP set enzyme" had a mutation at the AMP-binding site (Y95F, V67I, and V67I/L76V), and the "ATP set enzyme" had a mutation at a possible ATP-binding region (Y32F, Y34F, and Y32A/Y34A). Reaction rate constants obtained using steady state model analysis explained discrepancies found by the rapid equilibrium model analysis. (i) The unchanged number of bound AMPs for Y95F and the wild type despite the markedly increased K(m) values for AMP of the AMP set of enzymes was explained by alteration of the rate constants of the AMP step (k(+2), k(-2)) to retain the ratio k(+2)/k(-2). (ii) A 100 times weakened selectivity of ATP for Y34F in contrast to no marked changes in K(m) values for both ATP and AMP for the ATP set of enzymes was explained by the alteration of the rate constants of the ATP steps. A similar alteration of the K(m) and k(cat) values of these enzymes resulted from distinctive alterations of their rate constants. The pattern of alteration was highly suggestive. The most interesting finding was that the rate constants that decided the K(m) and k(cat) values were replaced by the mutation, and the simple relationships between K(m), k(cat), and the rate constants of K(m)1 = k(+1)/k(-1) and k(cat) = k(f) were not valid. The nature of the K(m) and k(cat) alterations was discussed.

Adenosine Monophosphate↗

PubMed2005

Both HDL3 and HDL2 exert a powerful anti-oxidative and protective effect against acceleration of oxidative modification of LDL by ascorbic acid.

The objective of the present study was to establish whether high-density lipoprotein 3 (HDL3) or high-density lipoprotein 2 (HDL2) might show an anti-oxidative effect on the acceleration of the oxidative modification of low-density lipoprotein (LDL) by ascorbic acid from measurement of the agarose gel electrophoretic mobility of LDL. LDL was incubated without adding transitional-metal ions for 48 or 96 h in phosphate-buffered saline (PBS) alone, with ascorbic acid (20 microg/mL), or with both ascorbic acid (20 microg/mL) and HDL3 (200 microg protein/mL). The LDL autoxidation occurred in PBS alone. Although ascorbic acid significantly suppressed oxidative modification of LDL after incubation for 48 h, the opposite was true after 96 h. However, since the anti-oxidative ability of HDL2 shows a weaker tendency than that of HDL3, both HDL3 and HDL2 significantly inhibited this acceleration of oxidative modification of LDL by ascorbic acid as assessed by electrophoretic mobility. If there is an augmented oxidative modification of LDL due to ascorbic acid in vivo, HDL3 or HDL2 may thus have an important role in inhibiting this ascorbic acid-accelerated oxidation of LDL.

Antioxidants↗

PubMed2002

HDL3 exerts a more powerful antiperoxidative and protective effect against peroxidative modification of LDL than HDL2 does.

The objective of the present study was to establish that HDL3 has a greater antiperoxidative effect on the peroxidative modification of LDL than HDL2 has. The protective influence of HDL subfractions on this form of LDL modification was examined in samples by measuring the concentration of thiobarbituric acid-reactive substance (TBARS), as well as the electrophoretic mobility of LDL. LDL was incubated for 96 hours in phosphate-buffered saline (PBS) alone, without the addition of transition-metal ions or in the presence of PBS and HDL2 or HDL3. All samples were subjected to agarose gel electrophoresis. Both HDL2 and HDL3 significantly inhibited peroxidative modification of LDL, as assessed by electrophoretic mobility, but this effect was much more pronounced with HDL3. HDL3 may play a more important role than HDL2 in the prevention of atherosclerosis in vivo by more effectively inhibiting LDL peroxidation.

Antioxidants↗