Search

Compared to clopidogrel, prasugrel has a lower incidence of ischemic events following percutaneous coronary intervention (PCI) because of an early reduction during the acute phase in P2Y12 reaction units (PRU). The objective of this study was to compare the antiplatelet effect and vascular endothelial function of both drugs during the chronic phase after PCI. Patients who had undergone PCI and were confirmed to have no restenosis by follow-up coronary angiography under dual anti-platelet therapy with clopidogrel (75 mg/day) and aspirin (100 mg/day) were randomized to either continue clopidogrel or switch to prasugrel (3.75 mg/day). At baseline, prior to randomization we determined the CYP2C19 genotype. At the baseline and 24 weeks after randomization, the P2Y12 reactivity unit (PRU) was measured using the VerifyNow™ P2Y12 assay. Endothelial function was evaluated by flow-mediated vasodilation (FMD) and reactive hyperemia peripheral arterial tonometry (RH-PAT), while and circulating CD34+/CD133+/CD45low progenitor cells were measured by flow cytometric analysis. Serum high-sensitivity C-reactive protein (hsCRP) level was also measured. The PRU was reduced significantly in the prasugrel group (P = 0.0008), especially in patients who were intermediate or poor metabolizers based on the CYP2C19 genotype (P < 0.0001). This reduction was not observed in the clopidogrel group. The number of CD34+/CD133+/CD45low cells increased in the clopidogrel group (P = 0.008), but not in the prasugrel group. The hsCRP, FMD and reactive hyperemia index measured by RH-PAT did not change in either group. Prasugrel is potentially better than clopidogrel for preventing thrombotic events, although clopidogrel may have an advantage over prasugrel in terms of preventing atherosclerotic events. Proper use of thienopyridine drugs based on the CYP2C19 genotype has promising clinical potential. [ABSTRACT FROM AUTHOR]

Right atrial pressure (RAP), a representative parameter of right heart failure, is very important for prognostic evaluation and risk assessment in pulmonary hypertension. However, its measurement requires invasive cardiac catheterization. In this study, we determined the most accurate echocardiographic surrogate of catheterization-based RAP. In 23 patients with pulmonary hypertension, a total of 66 cardiac catheterization procedures were performed along with 2-dimensional echocardiography. We evaluated tricuspid E/A, E', A' and E/E', and estimated RAP by the respirophasic variation of the inferior vena cava diameter (eRAP-IVCd) as possible surrogates of catheterization-based RAP. In simple linear regression analysis, E/A (R = 0.452, P = 0.0001) and eRAP-IVCd (R = 0.505, P < 0.0001) were positively correlated with catheterization-based RAP, whereas A' (R = − 0.512, P < 0.0001) was negatively correlated with RAP. In multiple regression analysis, A' was the most significant independent predictor of catheterization-based RAP (R = − 0.375, P = 0.0007). In 16 patients who had multiple measurements, there were a total of 43 measurements before and after medication changes. The absolute change in catheterization-based RAP was negatively correlated with the percent change in A'. Receiver operating characteristic curve analysis indicated that the optimal cut-off value of A' to predict a catheterization-based RAP > 10 mmHg was 11.3 cm/s (area under the curve = 0.782, sensitivity = 0.70, specificity = 0.78). In 20 measurements of 20 patients with left heart failure, catheterization-based RAP was not correlated with any of 5 echocardiographic parameters. However, it was closely correlated with catheterization-based pulmonary capillary wedge pressure. The echocardiographic parameter, A', was the best surrogate of catheterization-based RAP in patients with pulmonary hypertension. [ABSTRACT FROM AUTHOR]

Skeletal muscle is a plastic organ that adapts its mass to various stresses by affecting pathways that regulate protein synthesis and degradation. This study investigated the effects of repetitive restriction of muscle blood flow (RRMBF) on microvascular oxygen pressure (PmvO), mammalian target of rapamycin (mTOR) signaling pathways, and transcripts associated with proteolysis in rat skeletal muscle. Eleven-week-old male Wistar rats under anesthesia underwent six RRMBF consisting of an external compressive force of 100 mmHg for 5 min applied to the proximal portion of the right thigh, each followed by 3 min rest. During RRMBF, PmvO was measured by phosphorescence quenching techniques. The total RNA and protein of the tibialis anterior muscle were obtained from control rats, and rats treated with RRMBF 0-6 h after the stimuli. The protein expression and phosphorylation of various signaling proteins were determined by western blotting. The mRNA expression level was measured by real-time RT-PCR analysis. The total muscle weight increased in rats 0 h after RRMBF, but not in rats 1-6 h. During RRMBF, PmvO significantly decreased (36.1 ± 5.7 to 5.9 ± 1.7 torr), and recovered at rest period. RRMBF significantly increased phosphorylation of p70 S6-kinase (p70S6k), a downstream target of mTOR, and ribosomal protein S6 1 h after the stimuli. The protein level of REDD1 and phosphorylation of AMPK and MAPKs did not change. The mRNA expression levels of FOXO3a, MuRF-1, and myostatin were not significantly altered. These results suggested that RRMBF significantly decreased PmvO, and enhanced mTOR signaling pathways in skeletal muscle using a rat model, which may play a role in diminishing muscle atrophy under various conditions in human studies. [ABSTRACT FROM AUTHOR]

Although exercise oscillatory ventilation has emerged as a potent independent risk factor for adverse prognosis in heart failure, it is not well known whether cardiac rehabilitation can improve oscillatory ventilation. In this study, we investigated the magnitude of oscillations in ventilation before and after cardiac rehabilitation in chronic heart failure patients with exercise oscillatory ventilation. Cardiac rehabilitation (5-month program) was performed in 26 patients with chronic heart failure who showed an oscillatory ventilation pattern during cardiopulmonary exercise testing (CPX). After the 5-month rehabilitation program was completed, the patients again underwent CPX. To determine the magnitude of oscillations in ventilation, the amplitude and cycle length of the oscillations were calculated and compared with several other parameters, including biomarkers that have established prognostic value in heart failure. At baseline before cardiac rehabilitation, both oscillation amplitude ( R = 0.625, P < 0.01) and cycle length ( R = 0.469, P < 0.05) were positively correlated with the slope of minute ventilation vs. carbon dioxide production. Plasma BNP levels were positively correlated with amplitude ( R = 0.615, P < 0.01) but not cycle length ( R = 0.371). Cardiac rehabilitation decreased oscillation amplitude ( P < 0.01) but failed to change cycle length. The change in amplitude was positively correlated with the change in BNP levels ( R = 0.760, P < 0.01). Multiple regression analysis showed that only the change in amplitude was an independent predictor of the change in BNP levels ( R = 0.717, P < 0.01). A 5-month cardiac rehabilitation program improves exercise oscillatory ventilation in chronic heart failure patients by reducing the oscillation amplitude. This effect is associated with a reduction of plasma BNP levels, potentially contributing to an improvement of heart failure. [ABSTRACT FROM AUTHOR]

Purpose: The effects on muscle swelling were compared between low-load resistance exercise to exhaustion with (BFR) and without blood flow restriction (NBFR). Methods: Ten young men [aged 27 (SD 5) years, standing height 1.74 (SD 0.05) m, body mass 70.3 (SD 4.3) kg] performed 20 % of one repetition maximal dumbbell curl exercise to exhaustion (four sets, rest intervals were 30 s for BFR and/or 3 min for NBFR, respectively). One arm was randomly chosen for BFR exercise and the other arm performed NBFR exercise. During the BFR exercise session, an elastic cuff was worn proximally on the testing arm at 160 mmHg. Electromyography (EMG) signals were recorded from surface electrodes placed on the biceps brachii muscle and analyzed for integrated EMG (iEMG). Biceps brachii muscle thickness (MTH) was measured using B-mode ultrasound. Results: The total number of exercise repetitions was greater ( p < 0.01) in NBFR (221 ± 67 reps) than in BFR (111 ± 36 reps). During the exercise session, iEMG for biceps brachii muscles increased ( p < 0.01) during BFR and NBFR (3.94 and 4.45 times of baseline value). Immediately after the exercise, MTH sharply increased ( p < 0.01) with BFR and NBFR (1.21 and 1.20 times of baseline value). These results demonstrate that both BFR and NBFR exercises lead to pronounced muscle activation and muscle swelling. Conclusion: Low-load resistance exercise to exhaustion is an effective method for promoting muscle swelling regardless of BFR. Furthermore, our data indicate that the increase in muscle swelling for both NBFR and BFR is maintained even 60 min after the exercise. [ABSTRACT FROM AUTHOR]

Background: Although blood flow-restricted low-intensity resistance training (BFR-RT) increases muscle size and strength in older adults, the effect of detraining on muscle adaptation is unclear. Methods: We investigated the effects of 24 weeks of detraining on thigh muscle cross-sectional area (CSA) and one-repetition maximum strength (1-RM) in older adults who had previously participated in 12 weeks of training (BFR-RT, 20-30 % 1-RM, knee extension and leg press) or non-BFR training. Results: Both 1-RM and relative dynamic strengths (1-RM divided by quadriceps femoris (QF) muscle CSA) were higher at both post-training and detraining than at pre-training for the BFR-RT group ( p < 0.05). QF muscle CSA was higher at only post-training than at pre-training for the BFR-RT group ( p < 0.01). Conclusion: Increased muscle strength following 12 weeks of training with BFR-RT was well preserved at 24 weeks of detraining, which is due mainly to neural adaptation in older adults. [ABSTRACT FROM AUTHOR]

We examine developmental changes in the responsiveness of rat vestibular ganglion neurons (VGNs) to two neurotrophic factors (NTFs), brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) and investigate the protective effects of these NTFs against ototoxic drugs during postnatal development in dissociated cultures. VGNs were obtained from rats on postnatal days (P) 1, 3, 7 and 14. BDNF facilitated neuronal survival as well as neurite sprouting of VGNs obtained from younger rats (P1 and P3), whereas these effects were not observed in older rats (P7 and P14). BDNF was also effective in facilitating neurite extension in VGNs at each of the postnatal ages. NT-3 also facilitated neuronal survival and neurite extension of VGNs from younger rats but these effects were significantly smaller than those of BDNF ( p < 0.05). The protective effects of BDNF and NT-3 against ototoxic drugs, gentamicin and cisplatin, were also age-dependent: they were effective for neuronal survival, neurite sprouting and neurite extension in VGNs from younger rats, whereas these effects tended to disappear in VGNs from older rats. Analysis of the changes in the expression of the receptors of NTFs revealed that expression of TrkB and TrkC proteins and their mRNA did not change during the developmental period, whereas expression of p75 protein was down-regulated together with that of p75 mRNA during the developmental period. Developmental changes in the responsiveness to exogenous NTFs in VGNs, which is not caused by the changes of their receptors but probably caused by changes in the intracellular signaling pathways, should be taken into consideration in the prevention of neuronal degeneration caused by ototoxic drugs. [ABSTRACT FROM AUTHOR]

Genes of the immunoglobulin superfamily (IgSF) have a wide variety of cellular activities. In this study, we investigated molecular evolution of IgSF genes in primates by comparing orthologous sequences of 249 IgSF genes among human, chimpanzee, orangutan, rhesus macaque, and common marmoset. To evaluate the non-synonymous/synonymous substitution ratio (ω), we applied Bn-Bs program and PAML program. IgSF genes were classified into 11 functional categories based on the Gene Ontology (GO) database. Among them, IgSF genes in three functional categories, immune system process (GO:0002376), defense response (GO:0006952), and multi-organism process (GO:0051704), which are tightly linked to the regulation of immune system had much higher values of ω than genes in the other GO categories. In addition, we estimated the average values of ω for each primate lineage. Although each primate lineage had comparable average values of ω, the human lineage showed the lowest ω value for the immune-related genes. Furthermore, 11 IgSF genes, SIGLEC5, SLAMF6, CD33, CD3E, CEACAM8, CD3G, FCER1A, CD48, CD4, TIM4, and FCGR2A, were implied to have been under positive selective pressure during the course of primate evolution. Further sequence analyses of CD3E and CD3G from 23 primate species suggested that the Ig domains of CD3E and CD3G underwent the positive Darwinian selection. [ABSTRACT FROM AUTHOR]

High-intensity exercise shares similarities with acute phase responses of inflammatory diseases. We investigated the influences of acute exercise on inflammatory markers, plasma pentraxin3 (PTX3) and serum high-sensitive C-reactive protein (CRP) (hsCRP). Nine healthy male subjects (41 ± 3 years old) participated. Each subject performed three types of exercise; ergometer exercise at 70% workload of anaerobic threshold (AT) for 30 min (70% AT exercise), peak ergometer exercise (peak EX, 20 watt increase/min until fatigue) and resistance exercises of 70% 1 RM (70% RE) until exhaustion. We measured plasma PTX3, serum hsCRP, lactate, noradrenaline (NOR), white blood cells (WBC), interleukin-6 (IL-6) and myeloperoxidase (MPO), a marker of neutrophil degranulation. The effects of exercise on intracellular PTX3 and MPO in neutrophils were also investigated, by using flow cytometry analysis. Circulating PTX3 and hsCRP significantly increased immediately after 70% RE and peak EX, while they did not increase after 70% AT exercise. The exercise-induced fold increase in PTX3 and hsCRP relative to the resting level was positively correlated with the changes in WBC, NOR, lactate and MPO. The exercise-induced fold increase in IL-6 was positively correlated with that in NOR, but not with that in PTX3 and hsCRP. Neutrophils isolated immediately after 70% RE, but not 70% AT exercise, exhibited lower mean fluorescence for PTX3 and MPO than those from pre-exercise blood. These results provide the evidence that high-intensity exercises significantly increase circulatory PTX3 as well as hsCRP. The release from peripheral neutrophils is suggested to be involved in the exercise-induced plasma PTX3 increase. [ABSTRACT FROM AUTHOR]

deletion/insertion (Del/Ins) polymorphism of 28 base pairs (bp) in the 3′ untranslated region (UTR) of fibrinogen alpha gene ( FGA) was associated with thromboembolic diseases, but the underlying mechanisms remain unknown. Computational predication reveals that the 28 bp polymorphic fragment is complementary to the sequence of a microRNA, miR- 759. In this study, we aim to investigate the association and implicated mechanisms between FGA polymorphisms and the susceptibility to chronic thromboembolic pulmonary hypertension (CTEPH). The Del/Ins polymorphism was analyzed in 190 patients with CTEPH and 628 controls. The FGA 3′UTR and miR- 759 interaction was investigated using luciferase assay and quantitative RT-PCR method. Expression of miR- 759 and FGA in human tissues was investigated by RT-PCR. The results reveal that the allele frequency of Ins was significantly higher in the patients than in the controls (55.8 vs. 47.1%, P = 0.003, odds ratio = 1.42, 95% confidence interval: 1.13–1.79). Both miR- 759 and FGA were expressed in human liver. Co-transfection of miR- 759 decreased the expression and mRNA stability of reporter gene containing the FGA 3′UTR. The effect of miR- 759 was stronger on the Ins allele than on the Del allele. These observations suggest that the expression of FGA was regulated by miR- 759 through its interaction at the polymorphic 3′UTR sequence, which was associated with the susceptibility to CTEPH. [ABSTRACT FROM AUTHOR]

Coronary artery disease (CAD) is caused by a thrombotic occlusion or spasm of the coronary artery. Association of genetic variants with susceptibility to CAD has been reported in various populations, but the association should be replicated in other populations to establish the role of genetic variants in CAD. We conducted a case–control study with a total of 1480 CAD cases and 2115 controls from two East Asian populations, Japanese and Korean, to validate the associations of CAD with eight single nucleotide polymorphisms (SNPs) in eight loci, which were identified from large-scale whole-genome association studies in Europeans or East Asians. Among the tested SNPs, one SNP in BRAP (rs11066001) showed a significant association in allele frequency distribution with CAD in both the Japanese (Odds ratio (OR)=1.63, 95% confidence interval (CI); 1.41–1.89, P=5.0 × 10−11, corrected P (Pc)=4.0 × 10−10) and Korean populations (OR=1.68, 95% CI; 1.41–2.00, P=6.5 × 10−9, Pc=5.2 × 10−9), and a meta-analysis showed a significant association in the East Asian populations (OR=1.65, 95% CI; 1.48–1.85, P=1.8 × 10−18, Pc=1.4 × 10−17), whereas no evidence of association was found for the other SNPs. In addition, a combined analysis of BRAP and another CAD locus on 9p21 suggested that these loci had a synergistic role in the susceptibility. Failure to replicate the association with the other SNPs, which were reported in the European populations, suggested that their contributions to CAD were not large enough to be readily captured in the East Asian populations. [ABSTRACT FROM AUTHOR]

Coronary artery disease (CAD) is based on the atherosclerosis of coronary artery and may manifest with myocardial infarction or angina pectoris. Although it is widely accepted that genetic factors are linked to CAD and several disease-related genes have been reported, only a few could be replicated suggesting that there might be some other CAD-related genes. To identify novel susceptibility loci for CAD, we used microsatellite markers in the screening and found six different candidate CAD loci. Subsequent single nucleotide polymorphism (SNP) association studies revealed an association between CAD and megakaryoblastic leukemia factor-1 gene ( MKL1). The association with a promoter SNP of MKL1, −184C > T, was found in a Japanese population and the association was replicated in another Japanese population and a Korean population. Functional analysis of the MKL1 promoter SNP suggested that the higher MKL1 expression was associated with CAD. These findings suggest that MKL1 is involved in the pathogenesis of CAD. [ABSTRACT FROM AUTHOR]

Coronary artery disease (CAD) has become a major health problem in many countries because of its increasing prevalence and high mortality. Recently, an association of a functional sequence variation, −8C>G, in the human proteasome subunit α type 6 gene (PSMA6) with the susceptibility to CAD was reported. To validate the association, we investigated a total of 1330 cases and 2554 controls from Japanese and Korean populations for PSMA6 genotypes, and no evidence of the association was obtained in both Japanese (odds ratio (OR)=1.03, 95% confidence interval (CI); 0.90–1.19, P=0.66, allele count model) and Korean populations (OR=1.00, 95% CI; 0.86–1.17, P=0.95, allele count model). However, when a meta-analysis of data from this study and previously reported six replication studies was done, OR was 1.08 for the G allele (95% CI; 1.02–1.14, P=0.0057), suggesting that the contribution of PSMA6 to CAD was not large enough to be readily replicated. Further studies are required to establish the contribution of this variant in the susceptibility to CAD.Journal of Human Genetics (2009) 54, 248–251; doi:10.1038/jhg.2009.22; published online 13 March 2009 [ABSTRACT FROM AUTHOR]

The innate immune system constitutes the front line of host defense against pathogens. Toll-like receptors (TLRs) recognize molecules derived from pathogens and play crucial roles in the innate immune system. Here, we provide evidence that the TLR-related genes have come under natural selection pressure in the course of primate evolution. We compared the nucleotide sequences of 16 TLR-related genes, including TLRs ( TLR1–10), MYD88, TILAP, TICAM1, TICAM2, MD2, and CD14, among seven primate species. Analysis of the non-synonymous/synonymous substitution ratio revealed the presence of both strictly conserved and rapidly evolving regions in the TLR-related genes. The genomic segments encoding the intracellular Toll/interleukin 1 receptor domains, which exhibited lower rates of non-synonymous substitution, have undergone purifying selection. In contrast, TLR4, which carried a high proportion of non-synonymous substitutions in the part of extracellular domain spanning 200 amino acids, was found to have been the suggestive target of positive Darwinian selection in primate evolution. However, sequence analyses from 25 primate species, including eight hominoids, six Old World monkeys, eight New World monkeys, and three prosimians, showed no evidence that the pressure of positive Darwinian selection has shaped the pattern of sequence variations in TLR4 among New World monkeys and prosimians. [ABSTRACT FROM AUTHOR]

The KAATSU training is a unique method of muscle training with restricting venous blood flow, which might be applied to prevent muscle atrophy during space flight, but the effects of KAATSU in microgravity remain unknown. We investigated the hemodynamic responses to KAATSU during actually simulated weightlessness (6 degrees head-down tilt for 24 h, n = 8), and compared those to KAATSU in the seated position before bed rest. KAATSU was applied to the proximal ends of both the thighs. In the seated position before bed rest, sequential incrementing of KAATSU cuff pressure and altering the level of blood flow restriction resulted in a decrease in stroke volume (SV) with an increase in heart rate (HR). KAATSU (150-200 mmHg) decreased SV comparable to standing. Following 24-h bed rest, body mass, blood volume (BV), plasma volume (PV), and diameter of the inferior vena cava (IVC) were significantly reduced. Norepinephrine (NOR), vasopressin (ADH), and plasma renin activity (PRA) tend to be reduced. A decrease in SV and CO induced by KAATSU during the simulated weightlessness was larger than that in the seated position before bed rest, and one of eight subjects developed presyncope due to hypotension during 100 mmHg KAATSU. High-frequency power (HF(RR)) decreased during KAATSU and standing, while low-frequency/high-frequency power (LF(RR)/HF(RR)) increased significantly. NOR, ADH and PRA also increased during KAATSU. These results indicate that KAATSU blood flow restriction reproduces the effects of standing on HR, SV, NOR, ADH, PRA, etc., thus stimulating a gravity-like stress during simulated weightlessness. However, syncope due to lower extremity blood pooling and subsequent reduction of venous return may be induced during KAATSU in microgravity as reported in cases of lower-body negative pressure. [ABSTRACT FROM AUTHOR]

We set up a cohort of HIV-infected, asymptomatic Japanese patients with hemophilia for follow-up study in 1995. All subjects who had been infected with HIV-1 for more than 10 years met the criteria for long-term nonprogressors (LTNPs) at the time of entry; however, some of them later developed lymphopenia and required antiretroviral treatment during five more years of observation. In this study, we investigated the impacts of the CCL3L1 dose on the long-term prognosis in the subjects with chronic HIV-1 infection. We collected genomic DNA from 95 long-term survivors including 48 nonprogressors and 47 subjects receiving antiretroviral treatment. The distributions of CCL3L1 copy number significantly differed between the 95 HIV-1-infected subjects with hemophilia and 205 controls. Average copy number of CCL3L1 in the HIV-1-infected subjects was significantly lower than in control (5.00 ± 0.22 vs 3.35 ± 0.24, p < 0.001). Moreover, the subjects possessing two or less copies of CCL3L1 had significantly higher risk of acquiring HIV-1. However, CCL3L1 copy number variations had no significant effect on the disease progression among the LTNP subjects who had been afflicted with chronic HIV-1 infection for more than 15 years, when compared between nonprogressors and patients under treatment (3.68 ± 0.37 vs 3.02 ± 0.29, ns). Furthermore, variations in the CCL3L1 copy number had little effect on the levels of HIV-1 load among them. We conclude that variation in the CCL3L1 copy number is apparently not a factor that determines the prognosis of chronic HIV-1 infection, even though it is linked to HIV-1 susceptibility. [ABSTRACT FROM AUTHOR]

Buerger disease (BD) is an occulusive vascular disease of unknown etiology. Although cigarette smoking is a well-known risk factor of BD, genetic factors may also play a role in the etiology. Because chronic bacterial infection such as oral periodontitis is suggested to be involved in the pathogenesis of BD, gene polymorphisms involved in the infectious immunity might be associated with BD as the genetic factor(s). We have previously reported that HLA-DRB1*1501 and B54 was associated with BD in Japanese. In this study, polymorphisms in HLA-DPB1, DRB1 and B were analyzed in 131 Japanese BD patients and 227 healthy controls. In addition, we investigated a functional promoter polymorphism, −260 C > T, of CD14 that is a main receptor of bacterial lipopolysaccharide. It was found that the frequencies of CD14 TT genotype [37.4 vs. 24.2%, P = 0.008 OR = 1.87, 95% confidence interval (CI); 1.18, 2.97], DRB1*1501 (34.4 vs. 13.2%, P c = 4.4 × 10−5, OR = 3.44, 95%CI; 2.06, 5.73) and DPB1*0501 (79.4 vs. 55.1%, P c = 4.7 × 10−5, OR = 3.14, 95%CI; 1.93, 5.11) were significantly higher in the patients than in the controls, demonstrating that at least three genetic markers were associated with BD. Stratification analyses of these associated markers suggested synergistic roles of the genetic factors. Odds ratios ranged from 4.72 to 12.57 in individuals carrying any two of these three markers. These findings suggested that the susceptibility to BD was in part controlled by genes involved in the innate and adaptive immunity. [ABSTRACT FROM AUTHOR]

The application of an orthostatic stress such as lower body negative pressure (LBNP) has been proposed to minimize the effects of weightlessness on the cardiovascular system and subsequently to reduce the cardiovascular deconditioning. The KAATSU training is a novel method to induce muscle strength and hypertrophy with blood pooling in capacitance vessels by restricting venous return. Here, we studied the hemodynamic, autonomic nervous and hormonal responses to the restriction of femoral blood flow by KAATSU in healthy male subjects, using the ultrasonography and impedance cardiography. The pressurization on both thighs induced pooling of blood into the legs with pressure-dependent reduction of femoral arterial blood flow. The application of 200 mmHg KAATSU significantly decreased left ventricular diastolic dimension (LVDd), cardiac output (CO) and diameter of inferior vena cava (IVC). Similarly, 200 mmHg KAATSU also decreased stroke volume (SV), which was almost equal to the value in standing. Heart rate (HR) and total peripheral resistance (TPR) increased in a similar manner to standing with slight change of mean blood pressure (mBP). High-frequency power (HF(RR)) decreased during both 200 mmHg KAATSU and standing, while low-frequency/high-frequency power (LF(RR)/HF(RR)) increased significantly. During KAATSU and standing, the concentration of noradrenaline (NA) and vasopressin (ADH) and plasma renin activity (PRA) increased. These results indicate that KAATSU in supine subjects reproduces the effects of standing on HR, SV, TPR, etc., thus stimulating an orthostatic stimulus. And, KAATSU training appears to be a useful method for potential countermeasure like LBNP against orthostatic intolerance after spaceflight. [ABSTRACT FROM AUTHOR]

Multiple single nucleotide polymorphisms (SNPs) within ADAM33 have been reported to be associated with asthma and bronchial hyper-responsiveness in Caucasian populations. We examined whether these SNPs contribute to a predisposition to asthma, especially aspirin-intolerant asthma (AIA), in the Japanese population. Ten polymorphic sites (ST+4, ST+7, T1, T2, T+1, V-3, V-2, V-1, V4, V5) were genotyped in 102 AIA patients, 282 aspirin-tolerant asthma (ATA) patients and 120 control (CTR) subjects by direct sequencing. Haplotype frequencies were estimated by the expectation-maximization method. Differences in allele and haplotype frequencies among phenotypes were analyzed by the chi-square and permutation tests. ST+7, V-1 and V5 sites in the AIA group were significantly different from those in the ATA group ( P=0.034–0.004) and from those in the CTR group ( P=0.019–0.002). Haplotypes at three sites (ST+7, V-1, and V5) were significantly different in frequency between the AIA and ATA ( P=0.008) or CTR ( P=0.001) groups. Sequence variations in ADAM33 are likely to correlate with susceptibility to AIA in the Japanese population. [ABSTRACT FROM AUTHOR]

Genes encoding the serine proteinase inhibitor B family ( SERPINBs) are mainly clustered on human chromosome 18 (18q21). Several serpins are known to affect malignant phenotypes of tumor cells, so aberrant genetic variants in this molecular family are candidates for conferring susceptibility for risk of cancer. We investigated whether eight selected non-synonymous variations within SERPINB loci at 18q21 might be associated with risk of prostate cancer in Japanese men. A case-control study involving 292 prostate-cancer patients and 384 controls revealed significant differences in regard to distribution of four missense variations in genes encoding plasminogen activator inhibitor 2 ( PAI2) and SERPINB10. The most significant association was detected for the N120D polymorphism in the PAI2 gene ( P=5.0×10−5); men carrying the 120-N allele (120-N/N and 120-N/D genotypes) carried a 2.4-fold increased risk of prostate cancer (95% confidence interval 1.45–4.07). Associations were also detected for three other missense polymorphisms in those two genes. Strong linkage disequilibrium in the region encompassing PAI2 and SERPINB10 extended to about 50 kbp. The results suggested that missense variations in one or both of these genes confer important risks for prostate cancer, and may be themselves tumorigenic. Although confirmative replication studies on larger cohorts are awaited, clinical examination of these variations may become useful for identifying individuals at high risk for prostate cancer. [ABSTRACT FROM AUTHOR]

We investigated the hemodynamic and hormonal responses to a short-term low-intensity resistance exercise (STLIRE) with the reduction of muscle blood flow. Eleven untrained men performed bilateral leg extension exercise under the reduction of muscle blood flow of the proximal end of both legs pressure-applied by a specially designed belt (a banding pressure of 1.3 times higher than resting systolic blood pressure, 160-180 mmHg), named as Kaatsu. The intensity of STLIRE was 20% of one repetition maximum. The subjects performed 30 repetitions, and after a 20-seconds rest, they performed three sets again until exhaustion. The superficial femoral arterial blood flow and hemodynamic parameters were measured by using the ultrasound and impedance cardiography. Serum concentrations of growth hormone (GH), vascular endothelial growth factor (VEGF), noradrenaline (NE), insulin-like growth factor (IGF)-1, ghrelin, and lactate were also measured. Under the conditions with Kaatsu, the arterial flow was reduced to about 30% of the control. STLIRE with Kaatsu significantly increased GH (0.11+/-0.03 to 8.6+/-1.1 ng/ml, P < 0.01), IGF-1 (210+/-40 to 236+/-56 ng/ml, P < 0.01), and VEGF (41+/-13 to 103+/-38 pg/ml, P < 0.05). The increase in GH was related to neither NE nor lactate, but the increase in VEGF was related to that in lactate (r = 0.57, P < 0.05). Ghrelin did not change during the exercise. The maximal heart rate (HR) and blood pressure (BP) in STLIRE with Kaatsu were higher than that without Kaatsu. Stroke volume (SV) was lower due to the decrease of the venous return by Kaatsu, but, total peripheral resistance (TPR) did not change significantly. These results suggest that STLIRE with Kaatsu significantly stimulates the exercise-induced GH, IGF, and VEGF responses with the reduction of cardiac preload during exercise, which may become a unique method for rehabilitation in patients with cardiovascular diseases. [ABSTRACT FROM AUTHOR]

A hypercholesterolemic patient medicated with cerivastatin for 22 days resulted in acute rhabdomyolysis. CYP2C8 and CYP3A4 are the major enzymes responsible for the metabolism of cerivastatin, and a transporter, OATP2, contributes to uptake of cerivastatin to the liver. In this study, the patient’s DNA was sequenced in order to identify a variant that would lead to the adverse effect of cerivastatin. Three nucleotide variants, 475delA, G874C, and T1551C, were found in the exons of CYP2C8. The patient was homozygous for 475delA variant that leads to frameshift and premature termination. Accordingly, the patient is most likely lacking the enzyme activity. The patient’s children were both heterozygous for the mutation. The patient had three nucleotide variants in exon 4 (A388G) and exon 5 (C571T and C597T) of OATP2 that were all heterozygous. No nucleotide variation in the exons of CYP3A4 was identified. To our knowledge, this is the first report showing that the adverse effect of cerivastatin might be caused by the genetic variant of CYP2C8. [ABSTRACT FROM AUTHOR]

Ubiquitin is a highly conserved protein, and is encoded by a multigene family among eukaryote species. The polyubiquitin genes, UbB and UbC, comprise tandem multiple ubiquitin coding units without a spacer region or intron. We determined nucleotide sequences for the UbB and UbC of human, chimpanzee, gorilla, and orangutan. The ubiquitin repeat number of UbB was constant (3) in human and great apes, while that of UbC varied: 6 to 11 for human, 10 to 12 for chimpanzee, 8 for gorilla, and 10 for orangutan. The heterogeneity of the repeat number within closely related hominoid species suggests that a lineage-specific unequal crossover and/or gene duplication occurred. A marked homogenization of UbC occurred in gorilla with a low level of synonymous difference (ps). The homogenization of UbC also occurred in chimpanzee and less strikingly in human. The first and last ubiquitin coding units of UbC were clustered independently between species, and less affected by homogenization during the hominoid evolution. Therefore, the homogenization of ubiquitin coding units is likely due to an unequal crossing-over inside the ubiquitin units. The lineage-specific homogenization of UbC among closely related species suggests that concerted evolution has a key role in the short-term evolution of UbC. [ABSTRACT FROM AUTHOR]

We previously performed a genome-wide linkage study of intracranial aneurysm (IA) and found positive evidence of linkage at chromosomes 5q22-31, 7q11, and 14q22. In the present study, we focus on 5q31, where three candidate genes, fibroblast growth factor 1 (FGF1), fibrillin 2 (FBN2), and lysyl oxidase gene (LOX) lie, and evaluate associations with IA. Genomic DNAs were obtained from 172 IA patients and 192 controls. Association analysis was performed with ten, five, and four single-nucleotide polymorphisms (SNPs) identified in FGF1, FBN2, and LOX, respectively. A difference in allelic frequency was observed for only the SNP at intron 4 in FGF1 (χ[SUB2] = 4.44, df=1, P=0.035). Although a haplotype association was observed with the combination of ten SNPs in FGF1 (χ[SUB2] =16.04, df=1, P=0.00006), significant haplotype associations were not observed when haplotypes were constructed with the three, two, and four SNPs in FGF1 according to the linkage disequilibrium structure. No associations of FBN2 and LOX with IA were detected in the present study. [ABSTRACT FROM AUTHOR]

The extent and distribution of linkage disequilibrium (LD) in humans is a current topic especially for gene mapping of complex diseases. Akaike's information criterion (AIC) was applied to estimate LD and compared with other standard LD measures, D' and r². By comparison of an independent model (IM; linkage equilibrium) and a dependent model (DM; linkage disequilibrium), the parsimonious model is the one with the smaller AIC score. Therefore, the extent of LD by AIC is expressed as AIC(IM) — AIC(DM)(AIC(LD)). A total of 39 singlenucleotide polymorphisms on a 1.6-Mb region of chromosome 21q22 were identified, and genotyped in 192 Japanese individuals. All possible pairs were analyzed to estimate LD and the analyses were compared. AIC(LD) became highly positive as the D' value increased and was negative at D' values of around 0.2. Because a negative value of AIC(LD) implies linkage equilibrium, D' values below 0.2 should be regarded as linkage equilibrium. The LD estimate by AIC yielded results similar to those obtained by r², indicating that AIC(LD) would be useful for fine gene mapping. [ABSTRACT FROM AUTHOR]

Abstract Heterozygous familial hypercholesterolemia (FH) is a serious disorder causing twice normal low-density lipoprotein (LDL) cholesterol levels early in childhood and very early coronary disease in both men and women. Treatment with multiple medications together with diet can normalize cholesterol levels in many persons with FH and prevent or delay the development of coronary atherosclerosis. Previously published blood cholesterol criteria greatly under-diagnosed new cases of FH among members of known families with FH and over-diagnosed FH among participants of general population screening. Thus, there is a need for accurate and genetically validated criteria for the early diagnosis of heterozygous FH. In the course of investigations of coronary artery disease in Utah, we identified a family whose proband showed elevated plasma levels of LDL cholesterol. To carry out molecular genetic diagnosis of the disease, we screened DNA samples for mutations in all 18 exons and the exon-intron boundaries of the LDL receptor gene (LDLR). Novel point mutations were identified in the proband: a C-to-T transversion at nucleotide position 631, causing substitution of tyrosine for histidine at codon 190 in exon 4 of the LDLR gene. The mutant allele-specific amplification method was used to examine 12 members of the family recruited for the diagnosis. This method helped to unequivocally diagnose 7 individuals as heterozygous for this particular LDLR mutation, while excluding the remaining 5 individuals from carrier status with FH. [ABSTRACT FROM AUTHOR]

Neurokinin A (NKA) caused single tracheal smooth muscle cells (TSMCs) to contract. The effects of NKA on the electrical activity of guinea-pig TSMCs were examined using the tight-seal whole-cell patch-clamp technique. Under current-clamp conditions at rest, the membrane potential of TSMCs spontaneously oscillated at about −40 mV and NKA rapidly depolarized the membrane potential to nearly 0 mV, which then gradually repolarized to about −20 mV in the presence of NKA. The oscillations in potential disappeared transiently during the rapid phase of depolarization in response to NKA and reappeared during the sustained phase of depolarization. Under voltage-clamp conditions, NKA evoked an inward current which faded quickly. Subsequently, the cell conductance in the presence of NKA at potentials greater than −40 mV decreased gradually. The reversal potential of the NKA-induced inward current was about 0 mV, and shifted with changes in the Cl equilibrium potential. The Cl current was not elicited by NKA when using a pipette solution containing 10 mM ethylenebis(oxonitrilo) tetraacetic acid (EGTA). During the sustained phase, K currents evoked by depolarizing voltage steps were inhibited by NKA. The present results indicate that NKA causes rapid and sustained depolarization of TSMCs by two distinct mechanisms: (1) initial transient activation of the Ca-dependent Cl current, and (2) sustained inhibition of K currents. [ABSTRACT FROM AUTHOR]

We examined the effects of calcitonin gene-related peptide (CGRP) on the membrane currents of single atrial and ventricular cells of guinea pig heart. The tightseal whole-cell voltage-clamp technique was used. In atrial cells, like isoproterenol, CGRP increased the L-type Ca channel current ( I) in a concentration-dependent manner. Human CGRP-(8-37), a putative CGRP receptor antagonist, completely abolished the CGRP-induced increase of I. Although the effects of CRGP were similar to those of isoproterenol, propranolol, a β-adrenergic receptor antagonist, did not affect the CGRP-induced increase of I. After I had been maximally activated by isoproterenol (2 μM) or intracellular cyclic adenosine 5′-monophosphate (100 μM), CGRP failed to increase I. Acetylcholine antagonized the effects of CGRP on I. Unlike the effects on atrial cells, CGRP had no significant effects on the membrane currents of ventricular myocytes. Thes results indicate that CGRP increases I via adenylate cyclase activation by binding to specific membrane receptors in cardiac atrial myocytes. Furthermore, CGRP receptors are expressed in atrial cells but probably not in ventricular cells. [ABSTRACT FROM AUTHOR]

The short-term desensitization of the acetylcholine (ACh)-induced K channel current was examined in single atrial cells of guinea-pig heart. The tight-seal whole cell voltage clamp technique was used. The solution in the pipettes contained GTP or guanosine-5′-O-(3-thiotriphosphate) (GTP-γS, a non-hydrolyzable GTP analogue). In GTP-loaded cells, ACh evoked a specific K channel current via GTP-binding proteins (G) in a dose-dependent manner. The K current showed agonist-dependent desensitization similar to those reported in other cardiac tissues (Nilius 1983; Carmeliet and Mubagwa 1986). The cellular response to ACh was also desensitized by activation of P1-purinergic receptors with adenosine (Ado). In GTP-γS-loaded cells, the K current was gradually induced even in the absence of agonists, probably due to direct activation of G proteins by GTP-γS. In the early phase of the spontaneous current increase, ACh evoked a large current transiently. As the GTP-γS-induced activation of the current progressed, the magnitude of the ACh-evoked current transient became smaller and finally negligible. Similar results were obtained when Ado was used as an agonist instead of ACh to induce the K current. Therefore, it is indicated that the agonistreceptor interaction may not be essential for the desensitization of ACh-induced K current in atrial myocytes. [ABSTRACT FROM AUTHOR]

The molecular mechanisms underlying activation of a K channel by adenosine (Ado) and acetylcholine (ACh) were examined in single atrial cells of guinea-pig. Whole cell clamp and patch clamp techniques were used to characterize the K channel. In the whole cell clamp conditions, Ado and ACh increased the K channel current in a dose-dependent manner. The maximum responses and the apparent dissociation constants were different for Ado and ACh activations of the current. Theophylline blocked activation of the K current by Ado, while atropine blocked ACh-activation, indicating that two different membrane receptors were involved. Measurements of the conductance and kinetic properties of both whole cell and single channel currents indicate that Ado and ACh regulate the same K channels. In 'inside-out' patch conditions, GTP was required in the intracellular side of the membrane for activation of the K channel by agonists (present in the patch electrode). The A protomer of pertussis toxin inhibited the channel activation only when NAD was also present. Furthermore, GTP-γS, a non-hydrolyzable GTP analogue, gradually caused activation of the K channel in the absence of agonists. Therefore, it was concluded that Ado and m-ACh receptors link with the same population of K channels via GTP-binding proteins Ni and/or No in the atrial cell membrane. [ABSTRACT FROM AUTHOR]

The effect of coenzyme Q (CoQ) on the cyanide (CN)-induced ATP-sensitive K channel current (K) was examined in single atrial myocytes, using the patch clamp technique. Superfusion of the cells with a CN/low glucose bathing solution induced an outward current in the whole-cell clamp condition. Glibenclamide (1 μM) abolished this current, indicating that the current was carried through the K channel. After steady-state activation by CN, pinacidil (a K channel opener, 300 μM) failed to further increase the current. In cell-attached patches, CN, when applied to the bath, induced bursting openings of an 80 pS channel (the K channel). In cells preincubated for 30 min in a solution containing CoQ (100 μg/ml), CN-activation of the K channel was markedly attenuated both at the whole cell and at the single channel level. At the steady-state effect of CN in CoQ-treated cells, pinacidil (300 μM) activated the current to the maximum level achieved by CN in the control cells. These results suggest that CoQ reduces in the CN-induced KATP current not by affecting the channel itself but by preventing depletion of intracellular ATP caused by CN. [ABSTRACT FROM AUTHOR]

Buerger disease (BD) and Takayasu arteritis (TA) are rare vascular disorders. Although their etiology and pathogenesis have not been elucidated, several studies have suggested the involvement of innate immunity. Myeloid differentiation primary-response protein 88 (MyD88) is a key signaling adaptor for all Toll-like receptors, which have a central role in innate immunity. In the present study, we evaluated the association of MyD88 with BD and TA. We conducted case-control studies in Japanese populations composing of 131 BD cases, 90 TA cases and 270 healthy controls to be genotyped for a single nucleotide polymorphism rs7744 A>G in the 3′-untranslated region of MyD88 gene. The frequency of GG genotype was significantly lower in the BD patients than in the controls (6.9 vs 15.9%, P=0.011, odds ratio=0.39, 95% confidence interval; 0.19, 0.81), although there was no significant difference in the genotype frequencies between the TA patients and controls. It was suggested that MyD88 may confer resistance to BD in Japanese. Because this is the first report of the association between MyD88 and BD, replication studies in other cohorts are required. [ABSTRACT FROM AUTHOR]

Coronary artery disease (CAD) and stroke are the major health problems in many countries because of their increasing prevalence and high mortality. It is well known that CAD and stroke are based on atherosclerosis and shared environmental and genetic risk factors. Recently, an association of a functional sequence variation −154G>A in the angiotensin receptor-like 1 (AGTRL1) with a susceptibility to stroke was reported. In this study, we investigated a total of 1479 CAD cases and 2062 controls from the Japanese and Korean populations to validate the association of AGTRL1 with CAD. However, we obtained no evidence of the association in both the Japanese (odds ratio (OR)=0.95, 95% confidence interval (CI); 0.82–1.10, P=0.47, allele count model) and Korean (OR=0.90, 95% CI; 0.77–1.05, P=0.18, allele count model) populations. In addition, there was no trend of association between the risk allele and severity of coronary atherosclerosis. These data suggested that AGTRL1 did not contribute much to the atherosclerosis of the coronary artery. [ABSTRACT FROM AUTHOR]

Coronary artery disease (CAD) has become a major health problem in many countries. Recent genome-wide association studies have identified the association between rs1333049 on chromosome 9p21 and susceptibility to CAD in Caucasoid populations. In this study, we evaluated the associations of rs1333049 with CAD in Japanese (604 patients and 1,151 controls) and Koreans (679 patients and 706 controls). We found a significant association in both Japanese [odds ratio (OR) = 1.30, 95% confidence interval (CI); 1.13–1.49, p = 0.00027, allele count model] and Koreans (OR = 1.19, 95% CI; 1.02–1.38, p = 0.025, allele count model). These observations demonstrated that chromosome 9p21 was the susceptibility locus for CAD also in East Asians. [ABSTRACT FROM AUTHOR]

Effects of intracellular Mg in the activation of a muscarinic K channel were examined in single atrial cells, using patch-recording techniques. In 'cell-attached' patch recordings, acetylcholine (ACh) or adenosine (Ado), present in the pipette, activated a specific population of K channels. In 'inside-out' patches, openings of the K channel by ACh or Ado diminished and did not resume until Mg was added to the perfusate which contained GTP or GTP-γS, a non-hydrolyzable GTP analogue. Channel openings caused by GTP faded by removing Mg, while GTP-γS-induced openings persisted steadily even when both Mg and GTP-γS were removed. In contrast to the case of GTP-induced channel openings, the GTP-γS-induced openings were not inhibited by the A protomer of pertussi toxin with NAD. From these observations, we concluded: 1) Intracellular Mg is essential for GTP to activate the GTP-binding protein. 2) Deactivation of the N protein may be caused by hydrolysis of GTP to GDP. This process may not require Mg. 3) During the activation by GTP analogues, the N protein may be dissociated into its subunits. [ABSTRACT FROM AUTHOR]

Postsynaptic mechanisms underlying the anticholinergic effects of quinidine were examined in single atrial cells, using the tight-seal whole-cell recording technique. The solution in the glass pipettes contained guanosine-5′triphosphate (GTP) or guanosine-5′-O-(3-thiotriphosphate) (GTP-γS, a non-hydrolyzable GTP analogue). In both cases, acetylcholine (ACh), applied to the bath, induced a specific K current. In GTP-loaded cells, quinidine in the bath solution depressed the ACh-induced K current concentration-dependently. Atropine also blocked the K current. On the other hand, in GTP-γS-loaded cells, the ACh-induced current was not blocked by atropine and persisted even when ACh was washed out from the bath, indicating that GTP-γS causes uncoupling of the K channels from the muscarine receptors. Quinidine, however, did depress the increased K current concentration-dependently. The percent inhibition curves for quinidine to depress the K current were very similar between GTP-loaded and GTP-γS-loaded cells. From these observations, we suggest that direct inhibition of the muscarine receptor-activated K channel current by quinidine, and not blockade of the muscarine receptor itself, is mainly responsible for the anticholinergic effects of the drug in atrial myocytes. [ABSTRACT FROM AUTHOR]

Abstract We identified a new common amino acid polymorphism of isoleucine/valine at codon 796 in exon 16 of the gene for human sterol regulatory element binding protein (SREBP) cleavage-activating protein (SCAP), a central regulator of lipid synthesis and metabolism in animal cells. It can be detected as an Ms/I restriction fragment length polymorphism. The allelic frequencies were: isoleucine (A) allele, 0.57 and valine (G) allele, 0.43. This polymorphism may be useful for genetic studies of disorders affecting intracellular lipid metabolism and hyperlipidemia. [ABSTRACT FROM AUTHOR]

Abstract Sterol regulatory element binding protein (SREBP) cleavage-activating protein (SCAP) is a central regulator of lipid synthesis and uptake in animal cells. A polymorphic dinucleotide (CA) repeat sequence was isolated from a genomic clone containing the SCAP gene and was mapped to chromosome 3p21.3. High heterozygosity (0.89) makes this polymorphism a useful marker in the genetic study of disorders affecting lipid metabolism. [ABSTRACT FROM AUTHOR]

Abstract The transcriptional factor nuclear factor kappa-beta (NFKB) consists of a multicomponent protein complex that plays a major role in the regulation of many viral and cellular genes. The NFKB complex has two alternative DNA binding subunits. We isolated a polymorphic dinucleotide (CA) repeat sequence from a genomic clone containing the NFKB subunit 1 (NFKB1) gene located at 4q23-24. High heterozygosity (0.813) makes this polymorphism a useful marker in the genetic study of disorders affecting the immune response and cell differentiation. [ABSTRACT FROM AUTHOR]