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Biomedical subjects

H Adachi

Publications and source records attributed to H Adachi.

At least 91 records · Page 5Linked to original sources
PubMed2000

Elastofibroma of the sigmoid colon.

A case of elastofibroma occurring in the sigmoid colon of a 69 year-old woman is reported. The woman presented for survey of her gastrointestinal tract. Colonoscopy disclosed two polyps in the sigmoid colon, one of which was clinically considered to be recurrent adenoma. Histologically, the lesion had characteristic eosinophilic fibers and globules, termed elastofibroma fibers with hematoxylin and eosin stain. In addition, these elastinophilic materials were digested by elastase. Histological evaluation confirmed the diagnosis of elastofibroma. Our case might suggest that it is the result of long-term fibrosis after previous endoscopic resection of a sigmoid colonic adenoma.

Adenoma↗
PubMed2000

Association between alcohol intake and development of hypertension in Japanese normotensive men: 12-year follow-up study.

Although it has been suggested that alcohol intake is related to hypertension, few long-term prospective studies have investigated this relationship. We therefore conducted a prospective study in male residents of a farming community in Japan to determine whether heavy drinking would predispose to the development of hypertension. A total of 325 normotensive (< 140/90 mm Hg) men were enrolled in 1977. Twelve years later, 93 (28.6%) subjects became hypertensive (defined as blood pressure > or = 140/90 mm Hg or use of antihypertensive medication). The probability of the development of hypertension in heavy drinkers predicted from a logistic regression equation was 44.6% (relative risk: 2.05 versus nondrinkers) after adjusting for age and body mass index (BMI). It was 36.2% (relative risk: 1.86 versus nondrinkers) after a further adjustment for systolic blood pressure at baseline. A high odds ratio of 2.39 for the development of hypertension with alcohol intake of < 46 g/day versus > or = 46 g/day at baseline was obtained even after adjustments for age, BMI, and confounding factors. We conclude that habitual heavy drinking of alcohol is a risk factor for the development of hypertension. This is the first report demonstrating a significant relationship between habitual alcohol intake and the development of hypertension in a long-term prospective study in Japan.

Adult↗
PubMed2000

Left-right asymmetric expression of lefty2 and nodal is induced by a signaling pathway that includes the transcription factor FAST2.

The left-right (L-R) asymmetric expression of lefty2 and nodal is controlled by a left side-specific enhancer (ASE). The transcription factor FAST2, which can mediate signaling by TGF beta and activin, has now been identified as a protein that binds to a conserved sequence in ASE. These FAST2 binding sites were both essential and sufficient for L-R asymmetric gene expression. The Fast2 gene is bilaterally expressed when nodal and lefty2 are expressed on the left side. TGF beta and activin can activate the ASE activity in a FAST2-dependent manner, while Nodal can do so in the presence of an EGF-CFC protein. These results suggest that the asymmetric expression of lefty2 and nodal is induced by a left side-specific TGF beta-related factor, which is most likely Nodal itself.

Animals↗
PubMed2000

Characterization of two mu class glutathione S-transferases from guinea pig lens.

Glutathione S-transferase (GST) plays an important role in the detoxifications of foreign electrophiles. Two GSTs of class mu from guinea pig lens were purified with Sephacryl S-100 gelfiltration, S-Hexyl glutathione Agarose affinity and Q-Sepharose anion exchange chromatographies. These GSTs (GST-A and B) showed similar relative molecular masses of 22.9 and 22.5 kDa, respectively. Two protein bands which crossreacted with anti GSTYb1 (GST 3-3) were detected in lens cytosolic crude extract on Western blotting and they showed Mrs corresponding to the purified enzymes. These GSTs showed a strong resistance against H2O2, 1,2-naphthoquinone and superoxide anion consistent with the other GSTs in class mu from animal tissues.

Animals↗
PubMed2000

amiB, a novel gene required for the growth/differentiation transition in Dictyostelium.

BACKGROUND: The differentiation programme of Dictyostelium discoideum is initiated by starvation. Nutrient depletion triggers the differentiation of Dictyostelium cells through the transcriptional inactivation of some growth-phase genes, as well as through the transcriptional activation of essential genes required for the aggregation of the cells. The adenylyl cyclase (ACA) gene, acaA, is one of the earliest genes expressed following starvation. ACA produces intracellular and extracellular cAMP that drives further differentiation by inducing chemotaxis, developmental gene expression and morphogenesis of Dictyostelium cells. Although several genes have been identified as being essential for the initiation of differentiation process, such as the transcriptional activation of ACA expression, the molecular mechanisms of the growth/differentiation transition remain to be explored. RESULTS: Using insertional mutagenesis, we have isolated a mutant that does not aggregate upon starvation. The disrupted gene, amiB (aggregation minus B), is predicted to encode a novel protein of 298.9 kDa. When starved, amiB- cells produced an undetectable level of cAMP. Analyses of gene expression showed that amiB- cells fail to turn off the expression of one of the growth-phase genes, cprD, and to turn on the expression of ACA following starvation. The ectopic expression of ACA from a constitutive promoter rescued the differentiation and morphogenesis of amiB- mutants. Furthermore, the ectopic expression of a putative transcriptional factor DdMyb2 or a catalytic subunit of cAMP-dependent protein kinase (PKA-C), both of which are thought to be involved in ACA expression pathway(s), also rescued the starvation-induced ACA expression and further differentiation of the amiB- mutant. CONCLUSION: These results suggest that AmiB plays a role at the start of Dictyostelium differentiation through induction of the ACA expression which is essential for cAMP signalling.

Adenylyl Cyclases↗
PubMed2000

Resuscitation and circulatory support using extracorporeal membrane oxygenation for fulminant pulmonary embolism.

Fulminant pulmonary embolism (PE) with circulatory collapse is associated with a high mortality rate due to acute right ventricular failure and hypoxia. Immediate and appropriate resuscitation and circulatory support in the perioperative period is mandatory to prevent sudden death. Extracorporeal membrane oxygenation (ECMO) was recently introduced for extracorporeal life support in patients with circulatory collapse and has provided an excellent outcome. We report on the effectiveness of ECMO support for fulminant PE. Seven patients were placed on veno-arterial ECMO for circulatory collapse caused by fulminant PE refractory to conventional treatment. After resuscitation, all patients underwent pulmonary angiography, and thrombolytic therapy was administered in all 7 patients under ECMO support. Three patients who did not improve by thrombolysis underwent embolectomy with standard cardiopulmonary bypass. Two thrombolysis and 2 surgery patients were weaned from bypass and survived. The duration of support ranged from 18-168 h (mean = 67.8 +/- 67.1 h), with maximum bypass flow rates of 2.0-4.5 (mean = 3.5 +/- 0.9). There were no device-related complications during support. In total, 4 patients (57%) were successfully weaned from support and discharged from the hospital in good condition. All patients who survived required prolonged support (27, 82, 151, and 168 h). We conclude that resuscitation and circulatory support using ECMO can be effective, life-saving measures in cases of circulatory collapse caused by fulminant PE.

Adult↗
PubMed2000

Platelet activation in the gyro C1E3 centrifugal pump: comparison with the terumo capiox and the Nikkiso HPM-15.

The Gyro C1E3 was developed as a cardiopulmonary bypass pump incorporating the sealless double pivot bearing system. In this study, we evaluated platelet activation induced by the Gyro C1E3 in vitro and in comparison to that of other centrifugal pumps. Rates of increase (RI) for beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) in the Gyro C1E3 were calculated from in vitro data and compared with the rate of increase in the Capiox (Terumo) and HPM-15 (Nikkiso) pumps. Fresh human blood was used, and a flow of 5.0 L/min with a DeltaP (pressure difference between the outlet and inlet of the pump) of 100 mm Hg employed. RI = Deltabeta-TG/DeltaN and DeltaPF4/DeltaN were used where Deltabeta-TG is the increase in beta-TG, DeltaPF4 is the increase in PF4, and DeltaN is the increase in the passing number and where N = Qt/V (t = time, V = priming volume, and Q = flow rate). The mean RI for beta-TG was 0.26 +/- 0. 05 in the Gyro C1E3, 0.20 +/- 0.07 in the Capiox, and 0.15 +/- 0.02 in the HPM-15. The mean RI for PF4 was 0.15 +/- 0.03 in the Gyro C1E3, 0.12 +/- 0.05 in the Capiox, and 0.09 +/- 0.04 in the HPM-15. While there was no difference in RI for beta-TG and PF4 between the Gyro C1E3 and Capiox, RI for beta-TG and PF4 were significantly higher in the Gyro C1E3 than in the HPM-15 (p = 0.006 and 0.029). In vitro evaluation using RI for beta-TG and PF4 showed platelet damage caused by the Gyro C1E3 and the Capiox to be nearly equal while the HPM-15 was less traumatic to platelets than the Gyro C1E3.

Algorithms↗
PubMed2000

Influence of surgical procedures on interleukin-6 and monocyte chemotactic and activating factor responses: CABG vs. valvular surgery.

Interleukin-6 (IL-6) and monocyte chemotactic and activating factor/monocyte chemoattractant protein-1 (MCAF/MCP-1) play pivotal roles in systemic inflammation, immune response, and tissue damage after cardiopulmonary bypass (CPB). Previous reports have described transient rises in IL-6 and MCAF after CPB, but the data seem to vary according to the different surgical procedures used. To evaluate the influence of the different surgical procedures on the proinflammatory cytokine responses, we compared perioperative serum IL-6 and MCAF release in coronary artery bypass grafting (CABG) and valvular surgery cases. Eighteen CABG (CABG group) and 7 single valvular cardiac surgery patients (valve group) were included in this study. Blood samples were taken to measure the serum concentrations of IL-6 at the induction of anesthesia, at the removal of the aortic cross-clamp, at the end of CPB, at the end of surgery, and 24 h after the termination of surgery. Serum IL-6 and MCAF were assayed by ELISA. Serum IL-6 increased immediately after aortic declamping and reached its peak at the end of surgery in both groups. Serum IL-6 concentrations at the end of surgery and 24 h after surgery were significantly higher in the valve group than in the CABG group (123.9 +/- 21.7 pg/ml vs. 79.7 +/- 10.4 pg/ml, p = 0.049; 113.6 +/- 25.0 pg/ml vs. 39.9 +/- 11.5 pg/ml, p = 0.006, respectively). Serum MCAF increased immediately after aortic declamping, and the MCAF level at the end of surgery was significantly higher in the valve group than in the CABG group (1118.4 +/- 353.9 pg/ml vs. 241.0 +/- 71.2 pg/ml, p = 0.002, respectively). IL-6 and MCAF may play important roles in the pathophysiology of surgical damage with CPB, and the different surgical procedures appear to affect the proinflammatory cytokine release after cardiac surgery differently.

Chemokine CCL2↗
PubMed2000

Effects of tocotrienols on life span and protein carbonylation in Caenorhabditis elegans.

To assess the efficiency of tocotrienols against oxidative damage, we have demonstrated in a model-system nematode, Caenorhabditis elegans, that tocotrienol administration reduced the accumulation of protein carbonyl (a good indicator of oxidative damage during aging) and consequently extended the mean life span (LS), but not the maximum LS. Conversely, alpha-tocopherol acetate did not affect these parameters. As a way to evaluate the protective ability of tocotrienols against oxidative stress, the life spans of animals administrated tocotrienols before or after exposure to ultraviolet B-induced oxidative stress were measured. Ultraviolet B irradiation shortened the mean LS of animals, whereas preadministration of tocotrienols recovered the mean LS to that of unirradiated animals. Interestingly, postadministration also extended the mean LS more than that of unirradiated animals, and administration through the LS conferred greater protection. Thus, the administration of tocotrienols to animals results in a reduction of oxidative stress risks. These data indicated that tocotrienols merit further investigation as possible agents for antiaging and oxidative stress prevention. In addition, they suggest that C. elegans will continue to provide provocative clues into the mechanisms of aging.

Animals↗
PubMed2000

Intractable epilepsy associated with multiple cavernous malformations: case report.

OBJECTIVE AND IMPORTANCE: Epilepsy associated with cavernous malformations is often effectively controlled by lesionectomy alone. Detailed preoperative evaluation is necessary if the lesions are multiple and the seizures are medically intractable. We report on a patient with multiple cavernous malformations associated with medically intractable seizures who became seizure-free after a single gyrus resection. The importance of electroencephalography with video monitoring is emphasized. CLINICAL PRESENTATION: The patient was a 25-year-old man with a 10-year history of complex partial and generalized convulsions. Magnetic resonance imaging revealed more than 10 cavernous malformations. Video-electroencephalographic monitoring indicated that seizures originated from either the frontal or temporal lobe of the right hemisphere. INTERVENTION: Subdural electrodes were implanted, covering both frontal and both temporal lobes. The seizures originated in the right frontal lobe. The gyrus, including a calcified cavernous malformation, was removed, and multiple subpial transections of the surrounding cortices were performed. The patient has been free of seizures for 22 months after surgery. CONCLUSION: Medically intractable seizures associated with multiple cavernous angiomas can be controlled by a single resective procedure.

Adult↗
PubMed2000

Induction of the cytochrome P450 gene CYP26 during mucous cell differentiation of normal human tracheobronchial epithelial cells.

In this study, the expression of CYP26 is examined in relation to retinoid-induced mucosecretory differentiation in human tracheobronchial epithelial (HTBE) cells and compared with that in human lung carcinoma cell lines. In HTBE cells, retinoic acid (RA) inhibits squamous differentiation and induces mucous cell differentiation as indicated by the suppression of transglutaminase I and increased expression of the mucin gene MUC2. The latter is accompanied by increased expression of CYP26 mRNA. RA is required but not sufficient to induce RARbeta, CYP26, and MUC2 mRNA because induction is only observed in confluent but not in logarithmic cultures, suggesting that additional factors are critical in their regulation. CYP26 mRNA can be induced by the RAR-selective retinoid 4-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-anthracenyl)-benzoic acid (TTAB) but not by the RXR-selective retinoid SR11217 or the anti-activator-protein 1-selective retinoid SR11302. RARalpha-, beta-, and gamma-selective retinoids are able to induce CYP26; this induction is inhibited by the RARalpha-selective antagonist Ro41-5253. TTAB is able to induce CYP26 mRNA expression in only a few of the lung carcinoma cell lines tested. The lack of CYP26 induction in many carcinoma cell lines may relate to previously reported defects in the retinoid-signaling pathway. The induction of CYP26 correlated with increased metabolism of RA into 18-hydroxy-, 4-oxo-, and 4-hydroxy-RA. The latter metabolite was shown to be able to induce MUC2 and MUC5AC expression in HTBE cells. Our results demonstrate that in normal HTBE cells, CYP26 expression is closely associated with mucous cell differentiation and that many lung carcinoma cells exhibit increased RA metabolism and a defective regulation of CYP26.

Antineoplastic Agents↗
PubMed2000

Platelet-derived nitric oxide and coronary risk factors.

Platelet aggregation is inhibited through a negative feedback mechanism by the L-arginine/nitric oxide (NO) pathway found in platelets themselves. We have shown that long-term smoking impairs the bioactivity of platelet-derived NO (PDNO), resulting in an increased platelet aggregability. However, little is known about the relation between other coronary risk factors and PDNO release. Accordingly, this study was undertaken to examine whether other coronary risk factors are related to the impairment of PDNO bioactivity. We measured collagen-induced PDNO release with an NO-selective electrode in 61 subjects (mean age 47 years, range 24 to 74 years) who underwent complete physical and laboratory examinations. There was a significant inverse correlation between PDNO release and the number of coronary risk factors (r=-0.61, P<0. 001). Univariate analysis showed a significant inverse correlation between PDNO release and age (r=-0.33, P<0.01), mean arterial pressure (r=-0.40, P<0.002), total cholesterol level (r=-0.31, P<0. 02), and LDL-cholesterol level (r=-0.33, P<0.02). PDNO release was significantly lower in long-term smokers than in nonsmokers (P<0. 001). With multiple stepwise regression analysis, PDNO release correlated significantly and independently (r(2)=0.51), with smoking (F=37.8), age (F=7.1), and mean arterial pressure (F=5.1). Thus, we demonstrated that coronary risk factors are associated with an impairment of PDNO release by human platelets. Our findings may contribute to the understanding of the pathophysiological link between coronary risk factors and atherothrombotic disease.

Adult↗
PubMed2000

Activin/nodal responsiveness and asymmetric expression of a Xenopus nodal-related gene converge on a FAST-regulated module in intron 1.

Vertebrate Nodal-related factors play central roles in mesendoderm induction and left-right axis specification, but the mechanisms regulating their expression are largely unknown. We identify an element in Xnr1 intron 1 that is activated by activin and Vg1, autoactivated by Xnrs, and suppressed by ventral inducers like BMP4. Intron 1 contains three FAST binding sites on which FAST/Smad transcriptional complexes can assemble; these sites are differentially involved in intron 1-mediated reporter gene expression. Interference with FAST function abolishes intron 1 activity, and transcriptional activation of Xnrs by activin in embryonic tissue explant assays, identifying FAST as an essential mediator of Xnr autoregulation and/or 'signal relay' from activin-like molecules. Furthermore, the mapping of endogenous activators of the Xnr1 intronic enhancer within Xenopus embryos agrees well with the pattern of Xnr1 transcription during embryogenesis. In transgenic mice, Xnr1 intron 1 mimics a similarly located enhancer in the mouse nodal gene, and directs FAST site-dependent expression in the primitive streak during gastrulation, and unilateral expression during early somitogenesis. The FAST cassette is similar in an ascidian nodal-related gene, suggesting an ancient origin for this regulatory module. Thus, an evolutionarily conserved intronic enhancer in Xnr1 is involved in both mesendoderm induction and asymmetric expression during left-right axis formation.

Activins↗
PubMed2000

Lack of a relation between serum potassium concentration and exercise hyperpnea in patients with chronic heart disease.

Exertional dyspnea, a major symptom of patients with chronic heart failure, mainly stems from an abnormally high ventilatory response to exercise. However, there has been considerable controversy surrounding the mechanisms of respiratory control during exercise, especially regarding the role of serum potassium. We investigated the relation between serum potassium concentration [K+] and ventilation (VE) during exercise before and after oral supplements of potassium chloride in cardiac patients. Thirteen patients with chronic heart disease performed a 6-min constant-work-rate exercise (65.8+/-11.1 W) with respiratory gas measurements before initiating oral supplements of potassium chloride, 4 weeks after continued supplements, and 4 weeks after discontinuing supplements. Blood was sampled from a forearm vein at rest before exercise and at the end of exercise for measurement of [K+] and blood gases. The [K+] at rest was 3.66+/-0.30 mmol/L before oral supplements of potassium and significantly increased to 4.08+/-0.31 mmol/L (p<0.01) after supplements. In spite of the significant increases in the [K+], resting VE was not changed. While serum [K+] during exercise was significantly higher after potassium supplements than before, exercise VE was not influenced by the changes in [K+] throughout the study period. The findings of the present study strongly suggest that the chronic increase in the serum [K+] has no influence on the resting or exercise VE in patients with heart disease.

Adult↗
PubMed2000

Effect of long-term exercise training on blood viscosity during endurance exercise at an anaerobic threshold intensity.

Blood viscosity (etaB) is low in athletes, but the effect of exercise training on etaB during endurance exercise at an anaerobic threshold (AT) intensity in non-athletes is not well known, although it is known that exercise training sometimes induces the hyperviscosity syndrome. Fourteen subjects were recruited and divided into 2 groups: those who trained at an AT intensity for 30 min/day, 3 times weekly for 1 year (Group T, n=8), and sedentary subjects (Group C, n=6). The test protocol consisted of a single 30-min treadmill exercise at each individual's AT intensity, which was determined in advance. The etaB, plasma viscosity (etaP), and hematocrit were measured just before and at the end of the treadmill exercise. The subjects were not allowed to drink any water before exercise. In the Group C subjects, the hematocrit and etaP increased significantly and the etaB tended to increase. However, in the Group T subjects, the hematocrit and etaP did not increase and the etaB decreased significantly. These data indicate that long-term exercise training attenuates the increase in blood viscosity during exercise.

Adult↗
PubMed2000

Prognostic significance of cardiopulmonary exercise testing for 10-year survival in patients with mild to moderate heart failure.

Although a number of studies have investigated the prognostic significance of exercise variables, they have focused only on short-term prognosis in relatively severe heart failure. This study was carried out to determine whether the indices obtained during cardiopulmonary exercise testing have prognostic significance during a 10-year follow-up in mild to moderate heart failure. Three hundred and sixty-four consecutive patients with cardiac disease performed 4 min of 20-W warm-up, followed by a symptom-limited incremental exercise test on a cycle ergometer. In addition to the measurements of peak oxygen uptake (VO2) and gas exchange (anaerobic) threshold, the time constant of VO2 kinetics during the onset of warm-up exercise was calculated using a single exponential equation. Data on mortality were available for follow-up in 260 patients. After 3,331+/-610 days of follow-up, 29 cardiovascular-related deaths occurred. The time constant of VO2 in the nonsurvivors was 76.7+/-43.3 s and was significantly prolonged compared with that of survivors (55.3+/-30.6 s, p=0.001). Peak VO2 and gas exchange threshold were both significantly lower in nonsurvivors than in survivors. Kaplan-Meier survival curves for 10 years of follow-up demonstrated a survival rate of 89.0% for patients with a normal VO2 time constant (< 80 s) and 71.7% for those with a longer time constant (> or = 80 s), showing a significant difference in survival (p=0.0028). Respiratory gas parameters obtained during exercise testing, particularly the time constant of VO2 kinetics, were found to be useful for predicting long-term prognosis in patients with chronic heart failure. These results suggest that cardiopulmonary exercise testing could be more applicable in ambulatory patients with minimal symptoms or minimal functional impairment.

Actuarial Analysis↗
PubMed2000

Detecting viable hibernating myocardium in chronic coronary artery disease--a comparison of resting 201Tl single photon emission computed tomography (SPECT), 99mTc-methoxy-isobutyl isonitrile SPECT after nitrate administration, and 201Tl SPECT after 201Tl-glucose-insulin infusion.

To identify and quantify the amount of viable hibernating myocardium in patients with chronic coronary artery disease, resting 201Tl single photon emission computed tomography (SPECT) was compared with 99mTc-methoxy-isobutyl isonitrile (MIBI) SPECT after nitrate infusion (nitrate-99mTc-MIBI) and 201Tl SPECT after 201Tl with glucose-insulin-potassium infusion (201Tl-GIK) in 25 patients. Twenty-one patients also underwent completely left ventriculography beforehand and 5+/-4 months afterwards. SPECT images were divided into 9 segments and scored visually from 0 (normal uptake) to 3 (absent). The defect score was calculated as the summation of the total scores (TDS) in each patient. The TDS of nitrate-99mTc-MIBI images (6.3+/-4.3) and 201Tl-GIK images (5.8+/-4.2) were significantly lower than the 7.4+/-4.3 of resting 201Tl images (p<0.01). Based on the improvement of wall motion after coronary revascularization, the sensitivity of 201Tl-GIK imaging (85%) was significantly higher (p<0.05), and that of nitrate-99mTc-MIBI imaging (79%) also tended to be higher (p=0.08), than that of 201Tl imaging (62%) in detecting viable myocardium. The specificity of the 3 methods was almost the same. The nitrate-99mTc-MIBI and 201Tl-GIK methods were more useful than the resting 201Tl method for evaluating viable hibernating myocardium. Furthermore, the 201Tl-GIK method may provide a more accurate estimate of the amount of viable myocardium than the nitrate-99mTc-MIBI method.

Aged↗