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Biomedical subjects

T Okura

Publications and source records attributed to T Okura.

At least 19 recordsLinked to original sources
PubMed2005

Effects of aerobic exercise and obesity phenotype on abdominal fat reduction in response to weight loss.

OBJECTIVE: To test the effects on abdominal fat reduction of adding aerobic exercise training to a diet program and obesity phenotype in response to weight loss. DESIGN: A prospective clinical trial with a 14-week weight-loss intervention design. SETTING AND PARTICIPANTS: In total, 209 overweight and obese women were assigned to four subgroups depending on type of treatment and the subject's obesity phenotype: diet alone (DA) with intra-abdominal fat (IF) obesity (> or =mean IF area), diet plus exercise (DE) with IF obesity, DA with abdominal subcutaneous fat (ASF) obesity (<mean IF area) and DE with ASF obesity. Abdominal fat areas were evaluated by CT scans, with values adjusted for selected variables. RESULTS: Values were adjusted for age, menopausal status and change in body weight and total fat mass. The IF reductions were significantly (P<0.0001) greater in subjects with IF obesity phenotype (-45.1 cm2) compared to the ASF obesity phenotype (-22.2 cm2). The ASF reductions were significantly (P<0.001) greater for subjects with ASF obesity (-74.5 cm2) compared to IF obesity (-55.5 cm2). For IF obesity, the IF reduction was significantly (P<0.01) greater in the DE group (-49.3 cm2) than in the DA group (-37.8 cm2). CONCLUSION: These results suggest that for individuals with IF obesity, the efficacy on reducing IF of adding aerobic exercise training to a diet-alone weight-reduction program is more prominent (-49.3 cm2/-37.8 cm2=1.3 times) compared with DA. Moreover, abdominal fat reduction was found to be modified by obesity phenotype in response to weight loss.

Adult↗
PubMed2005

Association between carotid haemodynamics and inflammation in patients with essential hypertension.

Previous studies have shown that high blood pressure causes chronic inflammation. Hypertensive patients are reported to have high-circulating levels of proinflammatory cytokines such as interleukin-6 (IL-6) and high sensitive C-reactive protein (hs-CRP). The pulsatility index (PI) and resistive index (RI) are used as markers of peripheral vascular resistance. In the present study, we evaluated the relationship between carotid haemodynamics and the proinflammatory cytokines, IL-6 and hs-CRP. In all, 41 patients with essential hypertension participated. The intima-media thickness (IMT), peak systolic velocity (pVs), peak diastolic velocity (pVd) and mean velocity (mV) in the common carotid artery were measured using ultrasound Doppler flow methods, and PI [(pVs-pVd)/mV] and RI [(pVs-pVd)/pVs] were calculated. Serum IL-6 and hs-CRP concentrations were measured by an enzyme-linked immunosorbent assay. IMT was positively correlated with age and pulse pressure. Both PI and RI were positively correlated with pulse pressure, IL-6 and hs-CRP. A multiple regression analysis revealed that PI and RI were independently associated with hs-CRP. These results suggested that carotid haemodynamic parameters such as PI and RI are associated with atherosclerosis and inflammation in hypertensive patients.

Aged↗
PubMed2003

Association of polymorphisms in the estrogen receptor alpha gene with body fat distribution.

OBJECTIVE: To examine whether polymorphisms of the estrogen receptor (ER) alpha gene are associated with body fat distribution. DESIGN: Cross-sectional, epidemiological study of two single-nucleotide polymorphisms, a T --> C (PvuII) and an A --> G (XbaI), in the first intron of the ERalpha gene. SUBJECTS: A total of 2238 community-dwelling middle-aged and elderly Japanese population (age: 40-79 y). MEASUREMENTS: The ERalpha genotypes (by automated fluorescent allele-specific DNA primer assay system), anthropometric variables, fat mass (FM) and percentage FM (%FM) (by dual-energy X-ray absorptiometry). RESULTS: FM and waist were inversely associated with age (r=-0.630 and -0.504, respectively) in women with the GG genotype. On the other hand, waist circumference of the AA genotype was positively correlated with age (r=0.231). Thus, for middle-aged women (40-59 y) with the AG or GG genotype body mass index (BMI), %FM, FM, waist, hip and waist-to-hip ratio (WHR) were larger than those with the AA genotype. In particular, FM and waist were greater by 20% and 9%, respectively, for the GG genotype, compared to the AA genotype. Alternatively, FM and waist were smaller by 18% and 6%, respectively, in older women with the GG genotype, compared to the AA genotype. No effect was found among the A --> G polymorphisms for men. For both genders, no difference was found in any variables among the TT, TC and CC genotypes with the exception of BMI of older men (60-79 y). CONCLUSION: No association was found between the ERalpha gene polymorphisms and body fat distribution in men. For women, the A --> G polymorphism, in particular the GG genotype, may contribute to the development of upper-body obesity in middle-aged individuals, but may serve to decrease the whole-body and abdominal fat tissue of older individuals.

Absorptiometry, Photon↗
PubMed2002

Selective and sustained occupancy of prostatic alpha1-adrenoceptors by oral administration of KMD-3213 and its plasma concentration in rats.

This study examined the ex-vivo occupancy by KMD-3213 of alpha1-adrenoceptors in the prostate and other tissues of rats in terms of tissue selectivity and duration of occupancy in relation to plasma concentration. Oral administration of KMD-3213 (0.2-20.2 micromol kg(-1), 0.5 h) dose-dependently decreased [3H]prazosin binding sites (Bmax) in the prostate (42-74%) and submaxillary gland (54-88%) compared with the control value. In contrast, there was only a slight change in the Bmax values in the spleen and cerebral cortex of KMD-3213-treated rats. The alpha1-adrenoceptor occupancy in the prostate and submaxillary gland was increased, with plasma free concentration of KMD-3213 at 0.5 h after oral administration of KMD-3213 (0.6-20.2 micromol kg(-1)). The receptor occupancy in these tissues was much greater than that in the spleen, heart or cerebral cortex. After oral administration of KMD-3213 (6.1 micromol kg(-1)), the alpha1-adrenoceptor occupancy in the prostate and submaxillary gland occurred rapidly, in parallel with the rise in the plasma concentration of the drug, and it lasted for at least 24 h, despite a remarkable decrease in the plasma concentration. It is concluded that KMD-3213 may produce fairly selective and sustained occupancy of alpha1-adrenoceptors in the prostate, a target organ for treatment of bladder outlet obstruction in patients with benign prostatic hyperplasia.

Administration, Oral↗
PubMed2001

Targeted overexpression of CCAAT/enhancer-binding protein-delta evokes enhanced gene transcription of platelet-derived growth factor alpha-receptor in vascular smooth muscle cells.

Platelet-derived growth factor (PDGF) is thought to play a significant role in various models of vascular remodeling, particularly in the early process of vascular diseases. Its action is mediated by its specific receptor, the PDGF receptor. The PDGF alpha-receptor (PDGFalphaR) plays an important role in the growth and proliferation of vascular smooth muscle cells (VSMCs), and its gene expression is thought to be regulated by several potential transcriptional nuclear factors. However, the detailed mechanisms of tissue-specific transactivation of the PDGFalphaR gene in VSMCs remain to be clarified. We have previously demonstrated that the rat PDGFalphaR gene contains an enhancer core sequence for CCAAT/enhancer-binding proteins (C/EBPs) in its promoter region, and we have also suggested that C/EBP-delta is the principal factor involved in the induction of tissue-specific transcriptional activity of the PDGFalphaR gene in VSMCs. To explore the definitive roles of C/EBP-delta protein on PDGFalphaR gene transcription in VSMCs, we developed C/EBP-delta transgenic rats by using a chimeric fusion gene of the mouse smooth muscle alpha-actin promoter and an entire coding region of rat C/EBP-delta cDNA. This report describes the first successful targeted overexpression of C/EBP-delta capable of inducing PDGFalphaR gene transcription and modifying cell proliferative activity to PDGFs. Targeted overexpression of C/EBP-delta evokes high levels of PDGFalphaR gene expression, susceptibility to VSMC growth, and proliferation of VSMCs to PDGFs. The results obtained reveal evidence of a new role and new functional significance of C/EBP-delta on VSMC growth via the PDGFalphaR during the process of vascular remodeling and atherosclerosis.

Animals↗
PubMed2001

Peroxisome proliferator-activated receptor-gamma activation inhibits interleukin-1beta -mediated platelet-derived growth factor-alpha receptor gene expression via CCAAT/enhancer-binding protein-delta in vascular smooth muscle cells.

CCAAT/enhancer-binding protein (C/EBP)-binding motifs have been identified in the promoter regions of interleukin (IL)-6, tumor necrosis factor-alpha, and platelet-derived growth factor-alpha receptor (PDGFalphaR). Recently, peroxisome proliferator-activated receptors (PPARs) have been suggested to be important immunomodulatory mediators. Although many studies have demonstrated that the interaction between C/EBPs and PPARs plays a central role in lipid metabolism, expression and function of these factors are unknown in vascular smooth muscle cells (VSMCs). In the present study, we clarified a functional relationship between C/EBPs and PPARgamma in the regulation of IL-1beta-induced PDGFalphaR expression in VSMCs. PPARgamma activators, troglitazone and 15-deoxy-Delta(12,14)-prostaglandin J(2), inhibited IL-1beta-induced PDGFalphaR expression and suppressed PDGF-induced proliferation activity of VSMCs. Electromobility shift and supershift assays for a C/EBP motif in the PDGFalphaR promoter region revealed that PPARgamma activators suppressed IL-1beta-induced DNA binding activity of C/EBPdelta and beta. PPARgamma activators also suppressed IL-1beta-induced C/EBPdelta expression. In contrast, overexpression of C/EBPdelta reversed the suppressive effect of PPARgamma activators on PDGFalphaR expression almost completely. From these results, we conclude that the inhibitory effect of PPARgamma activators on PDGFalphaR expression is mainly mediated by C/EBPdelta suppression. Regulation of C/EBPdelta by PPARgamma activators probably plays critical roles in modulating inflammatory responses in the arterial wall.

Animals↗
PubMed2001

Successfully treated composite graft infection after Bentall's procedure.

A 47-year-old male patient underwent Bentall's modification with total arch replacement owing to type A acute dissection. Mediastinitis and composite graft infection occurred 3 weeks after the operation. Extensive debridement and irrigation followed by omental wrapping without graft removal were performed and the patient was successfully cured.

Aneurysm, Infected↗
PubMed2001

Nuclear factor 1 is a negative regulator of gadd153 gene expression in vascular smooth muscle cells.

Growth arrest and DNA damage inducible gene 153 (gadd153) is expressed at very low levels in growing cells but is markedly induced in response to cellular stresses, including glucose deprivation, exposure to genotoxic agents, and other growth-arresting situations. Forced expression of GADD153 can induce cell cycle arrest and/or apoptosis in many types of cells. Recently, we reported that GADD153 was induced in vascular smooth muscle cells (VSMCs) in neointimal lesions of balloon-injured carotid arteries. To investigate the underlying molecular mechanisms of gadd153 gene expression in VSMCs, we isolated and characterized a promoter region of the rat gadd153 gene. Sequence alignments of this region revealed 1 TATA-like sequence and several well-known cis elements. The 5'-deletion analysis for this region showed that a domain spanning -447 through -368 drastically reduced the promoter activity to almost equal levels of promoterless control. Because this domain contained a consensus sequence for the nuclear factor 1 family of proteins (NF1), DNA-binding studies were performed by use of 2 types of NF1 consensus probes. Both probes were specifically shifted by nuclear extracts from proliferating VSMCs and were supershifted by antiserum against CCAAT transcription factor/NF1. In addition, promoter activity of a mutant luciferase vector, which was generated by a point mutation at the NF1 binding motif of the gadd153 gene, was 14-fold higher than that of a wild-type one. These results suggest that gadd153 gene expression in VSMCs is negatively regulated by an NF1-binding motif, and NF1 may act as an antiapoptotic factor by continuously suppressing gadd153 gene expression in growing VSMCs.

Animals↗
PubMed2001

Hypoglycemic syncope induced by a combination of cibenzoline and angiotensin converting enzyme inhibitor.

A 65-year-old Japanese woman with dilated cardiomyopathy, hypothyroidism and refractory sustained ventricular tachycardia experienced a near-death hypoglycemic syncope. The attack seemed to be induced by a high level of serum insulin, probably due to cibenzoline and by concomitant use of an angiotensin converting enzyme inhibitor (ACEI). Additionally, decreased food intake because of a severe toothache may have contributed to the deterioration of her condition. This case warns cardiologists that a combined cibenzoline and ACEI therapy can provoke serious adverse effects such as hypoglycemic syncope in the elderly. Therefore, the possibility of a hypoglycemic attack associated with these drugs should be explained to patients who are in poor condition.

Aged↗
PubMed2001

A unique method for predicting cardiorespiratory fitness using rating of perceived exertion.

The purpose of this study was to develop a simple and convenient indirect method for estimating maximal oxygen uptake (VO2max) and oxygen uptake at the anaerobic threshold (VO2AT) by using workrate and a rating of perceived exertion (RPE) during a submaximal graded cycling test (GCTsubmax). One hundred and fifty-four healthy Japanese men, aged 20 to 64 years, volunteered to participate in the study. The subjects were randomly divided into two groups, a validation (V) group (n = 100) and a cross-validation (CV) group (n = 54). The V and CV groups performed a maximal cycling test and the GCTsubmax. The GCTsubmax was conducted with documentation of three categories (overall, chest, legs) of RPE, up to a rating of 15. Prediction equations of VO2max and VO2AT were developed by multiple regression analysis using data of the V group. The mean VO2max and VO2AT of the V group were 2462 +/- 484 ml.min-1 and 1349 +/- 334 ml.min-1, respectively. Correlational analyses indicated that the workrate (W) at which the legs RPE (RPElegs) reached 15 or higher was evaluated first (WRPE legs 15) together with WRPE legs 14 both yielded the highest correlation coefficients (r) with VO2max (r = 0.781) and V O2AT (r = 0.790), respectively. The developed prediction equations of VO2max and VO2AT were VO2max (ml.min-1) = 1.19 WRPE legs 15 (kgm.min-1) - 15.84 age (yr) + 13.06 weight (kg) + 1365 (R = 0.849, SEE = 261 ml.min-1) VO2AT (ml.min-1) = 1.34 WRPE legs 14 (kgm.min-1) - 5.49 age (yr) + 665 (R = 0.816, SEE = 195 ml.min-1) Results of a cross-validation analysis indicated a similar estimation (r = 0.793 and 0.853, and SEE = 240 ml.min-1 and 183 ml.min-1) compared with the above equations developed from data of the V group. Reliability coefficients of V O2max (r = 0.891) and VO2AT (r = 0.870) respectively were significant and there was no difference in the mean value between trials 1 and 2. The "RPE method" developed for estimating cardiorespiratory fitness is not only a unique indirect method but also a valid and useful tool in various settings of exercise prescription.

Adult↗
PubMed2001

Ultrasonography of gastric volvulus: "peanut sign".

We report a case of chronic gastric volvulus in which ultrasonography (US) was useful. An 81-year-old woman was hospitalized due to vomiting, and upper gastroduodenoscopy revealed that the stomach was spirally twisted and constricted. An upper gastrointestinal barium study demonstrated an organoaxial-mesenteroaxial combined type gastric volvulus. US showed constriction between the dilated upper stomach body and the lower stomach body similar to a "peanut". Thereafter, the patient's vomiting stopped and follow-up US demonstrated that the constriction of the stomach was loosened. Therefore, we believe that this characteristic US sign paralleled the symptoms of the patient.

Aged↗
PubMed2001

In vivo demonstration of alpha(1A)-adrenoceptor subtype selectivity of KMD-3213 in rat tissues.

The present study was undertaken to characterize the in vivo alpha(1)-adrenoceptor binding of KMD-3213, a novel selective antagonist of alpha(1A)-adrenoceptors, in rat tissues by using a tritiated ligand with high specific activity, in comparison with that of [(3)H]prazosin. A significant degree of in vivo specific binding of [(3)H]KMD-3213 after i.v. injection of the radioligand (1. 4 nmol/kg) was seen in most rat tissues, except the cerebral cortex, spleen, and liver, which showed a little or no specific binding. There was a notable difference among tissues in the time course of specific [(3)H]KMD-3213 binding after i.v. injection of the ligand. The specific binding in the lung, kidney, and spleen was greatest at 10 min and declined rapidly with the disappearance of the ligand from the plasma. On the other hand, [(3)H]KMD-3213 binding in the submaxillary gland, vas deferens, and prostate attained peak levels at 60 min, and a considerable degree of binding was present even at 240 min. After i.v. injection of a similar dose (1.2 nmol/kg) of [(3)H]prazosin in rats, the in vivo specific binding in the submaxillary gland was greatest at 10 min and then it fell rapidly, whereas [(3)H]prazosin binding in the spleen attained a peak level at 60 min, and this was maintained even at 120 min. The AUC(0-120) values of the specific binding for [(3)H]KMD-3213, compared with those of [(3)H]prazosin, were markedly lower in the rat aorta, spleen, and liver, whereas the prostate, submaxillary gland, and lung showed significantly higher AUC(0-120) values of [(3)H]KMD-3213 compared with [(3)H]prazosin. Furthermore, the in vivo specific binding of [(3)H]KMD-3213 at dose ranges of 1.4 to 13.6 nmol/kg increased linearly in the prostate and submaxillary gland, but did not increase in a dose-dependent manner in the spleen. On the other hand, there was a dose-dependent increase in the in vivo specific binding of [(3)H]prazosin at doses of 1.2 to 10.6 nmol/kg in all tissues. The in vivo specific binding of [(3)H]KMD-3213 in rat tissues was reduced by concomitant i.v. injection of low doses of prazosin in a dose-dependent manner, but not by even a relatively high dose of yohimbine. In conclusion, the present study shows that KMD-3213 binds to the alpha(1A)-adrenoceptor subtype with a higher affinity than to the alpha(1B)- and alpha(1D)- subtypes under in vivo condition, thus leading to prostate selectivity.

Adrenergic alpha-Antagonists↗
PubMed2001

Role of GADD153 (growth arrest- and DNA damage-inducible gene 153) in vascular smooth muscle cell apoptosis.

GADD153 (growth arrest- and DNA damage-inducible gene 153) is expressed at very low levels in growing cells, but is markedly induced in response to a variety of cellular stresses, including glucose deprivation, exposure to genotoxic agents and other growth-arresting situations. Forced expression of GADD153 induces cell cycle arrest in many types of cells. It is also reported that GADD153 is directly associated with apoptosis. Recently we have reported that platelet-derived growth factor (PDGF)-BB induces apoptosis in cultured vascular smooth muscle cells (VSMC), but only when 100% confluency is reached. These results suggested that cell-cell contact inhibition (cell growth arrest) may be a critical factor for induction of VSMC apoptosis by PDGF-BB. In the present study, we explored the role of GADD153, one of a number of growth-arrest-related gene products, in the molecular mechanisms of VSMC apoptosis in vitro and in vivo. GADD153 was markedly induced at both the mRNA and protein levels, in parallel with the induction of VSMC apoptosis, after treatment with PDGF-BB. Moreover, overexpression of GADD153 in VSMC significantly reduced cell viability and induced apoptosis. In the carotid artery balloon injury model in rats, GADD153 protein was expressed in apoptotic VSMC which were positively stained by in situ DNA labelling. These results demonstrate an important role for GADD153 in the molecular mechanisms of VSMC apoptosis.

Analysis of Variance↗
PubMed2000

Troglitazone induces apoptosis via the p53 and Gadd45 pathway in vascular smooth muscle cells.

Thiazolidinediones, activators of peroxisome proliferator-activated receptor (PPAR)gamma, have been reported to induce apoptosis in many types of cells. In the present study, we investigated the effects of thiazolidinediones, troglitazone, and pioglitazone on the cell growth of vascular smooth muscle cells, and identified a specific effect of troglitazone in addition to PPARgamma activation. Subconfluent rat culture vascular smooth muscle cells were treated with or without PPARgamma activators, troglitazone (1-30 microM), or pioglitazone (1-30 microM) for 72 h. After treatment, cell viability was significantly reduced by troglitazone in concentrations of 5-30 microM but not by pioglitazone. Vascular smooth muscle cells appeared to float and shrink 48 h after treatment with 20 microM of troglitazone. In situ DNA labeling showed that the nuclei of these cells were positively stained, and genomic DNA extracted from the cells showed nucleosomal laddering. Messenger RNA expression levels of c-myc, p21, bax, bcl-2, and bcl-x were not changed by the treatment with troglitazone. In contrast, along with the induction of vascular smooth muscle cell apoptosis, both the mRNA and protein expression levels of p53 and Gadd45 markedly increased in response to troglitazone. These results strongly suggest that troglitazone can induce vascular smooth muscle cell apoptosis and that this effect is caused primarily by activation of the p53 and Gadd45 pathway but not by PPARgamma activation.

Animals↗
PubMed2000

Differential down-regulation of the human delta-opioid receptor by SNC80 and [D-Pen(2),D-Pen(5)]enkephalin.

We examined the contribution of the human delta-opioid receptor carboxyl terminal tail to (+)-4-[(alphaR)-alpha-((2S,5R)-4-allyl-2, 5-dimethyl-1-piperazinyl)-3-methoxybenzyl]-N,N-diethylbenzamide (SNC80)- and cyclic[D-Pen(2),D-Pen(5)]enkephalin (DPDPE)-mediated receptor down-regulation. Both SNC80 and DPDPE mediated down-regulation of an epitope tagged human delta-opioid receptor. Truncation of the human delta-opioid receptor after Gly(338) blocked DPDPE-mediated down-regulation. However, SNC80 mediated significant down-regulation of the truncated receptor. These findings suggest that SNC80-mediated down-regulation involves receptor domains in addition to the carboxyl terminal tail.

Benzamides↗
PubMed2000

Polygonum tinctorium extract suppresses nitric oxide production by activated macrophages through inhibiting inducible nitric oxide synthase expression.

Despite its beneficial role in host defense mechanisms, excessive nitric oxide (NO) production by activated macrophages has been implicated in several inflammatory diseases. To clarify the mechanisms of anti-inflammatory activities of Polygonum tinctorium, we evaluated whether extracts of P. tinctorium could modulate the production of NO by activated macrophages. An AcOEt extract of P. tinctorium markedly inhibited NO synthesis by interferon-gamma (IFN-gamma)/lipopolysaccharide (LPS)-stimulated murine peritoneal macrophages and the macrophage-like cell line RAW 264.7 in a dose-dependent manner. Inhibition of NO synthesis was achieved by reducing inducible NO synthase (iNOS) expression at protein and mRNA levels. However, the AcOEt extract of P. tinctorium failed to inhibit NO synthesis when iNOS was already expressed following stimulation with IFN-gamma and LPS. The AcOEt extract also exhibited inhibitory activity on iNOS expression in human lung epithelial A549 cells stimulated with a combination of IFN-gamma, TNF-alpha and IL-1 beta without affecting the expression of constitutive isoforms of NOS. Furthermore, in vivo injection of the AcOEt extract of P. tinctorium into LPS-treated mice significantly reduced NO synthesis by peritoneal exudate cells under ex vivo conditions. These results suggest that P. tinctorium extract may be a potential therapeutic modulator of NO synthesis in various pathological conditions.

Animals↗
PubMed2000

Coronary spastic angina induced by anticholinesterase medication for myasthenia gravis--a case report.

Myasthenia gravis (MG) is characterized by weakness of skeletal muscles because of a decrease in the number of available acetylcholine receptors at neuromuscular junctions. Anticholinesterase medication is widely used to treat MG, but muscarinic side effects sometimes appear and limit the drug usage. To their knowledge, the authors present the first case of coronary spastic angina quite possibly induced by anticholinesterase medication to treat MG. The appearance of coronary spastic angina in the present case is likely mediated through the increase of acethylcholine by anticholinesterase medication.

Aged↗