Dissociation of a complex of F-actin and H-meromyosin by addition of adenosine triphosphate.
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Adenosine Triphosphatases↗
Biomedical subjects
T Nakata
Publications and source records attributed to T Nakata.
The spectrum of findings in supra-aortic Takayasu's arteritis as seen on spiral CT angiography and digital subtraction angiography.
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Adult↗
A three-step purification of manganese superoxide dismutase from human liver on both large and small scales.
A new method for the purification of manganese superoxide dismutase from human liver is described. The procedure involves essentially three steps: DEAE-cellulose, hydroxylapatite, and butyl-Toyopearl chromatographies. The method has several advantages: (i) its simplicity and rapidity (it takes less than 3 days), (ii) its high yield (62%) with a high specific activity (5660 units/mg of purified SOD), and (iii) its suitability for both large- and small-scale purifications.
Chromatography↗
Cardiac death prediction and impaired cardiac sympathetic innervation assessed by MIBG in patients with failing and nonfailing hearts.
BACKGROUND: Although cardiac sympathetic nerve dysfunction is related to poor clinical outcome, a critical sympathetic dysfunction level for predicting cardiac death is still unclear. The current study was designed to investigate which indices derived from metaiodobenzylguanidine (MIBG) imaging have prognostic value compared with clinical and cardiac function variables, and to determine the threshold of cardiac MIBG activity for identifying patients likely to suffer cardiac death in both failing and nonfailing hearts. METHODS AND RESULTS: Myocardial I-123-MIBG activity was quantified as a heart-to-mediastinum ratio in 414 consecutive patients, 173 (42%) of whom had symptomatic heart failure. After cardiac function measurements, patients were followed up with an end-point of cardiac or noncardiac death. During a mean follow-up period of 22 months, 37 cardiac deaths occurred: 23 resulted from heart failure, 9 were sudden cardiac deaths, and 5 were fatal myocardial infarctions. Multivariate analysis using the Wald chi2 and the Cox proportional hazard model revealed that late heart-to-mediastinum ratio, the use of nitrates, early heart-to-mediastinum ratio, and left ventricular ejection fraction were independent predictors of cardiac death; late heart-to-mediastinum ratio, New York Heart Association (NYHA) class, the presence of previous myocardial infarction, and age were independent predictors of heart failure and sudden cardiac death. Late heart-to-mediastinum ratio was the most powerful predictor of overall cardiac death among the variables. The Kaplan-Meier analysis showed that a late heart-to-mediastinum ratio of 1.74 or less, age greater than 60 years, the presence of myocardial infarction, and NYHA functional class 3 or 4 strongly indicated poor clinical outcomes. Furthermore, the more powerful incremental prognostic values were obtained by using MIBG imaging in combination with conventional clinical variables. CONCLUSIONS: Impaired cardiac sympathetic innervation assessed by MIBG activity has the greatest potential for predicting cardiac death and may be useful for identifying a threshold level for selecting patients at risk for death by heart failure, sudden cardiac death, and fatal myocardial infarction.
3-Iodobenzylguanidine↗
Representation of molecular configurations by CAST coding method.
A configurational CAST (CAnonical representation of STereochemistry) coding method, which represents relative and absolute configuration, is described. The configurational CAST codes are constructed by canonical rotation of the dihedral angles of the input structure before the CAST codes are assigned. Using the configurational CAST, configurational differences can be distinguished independently of conformational differences. Representation of enantiomers is also achieved by a mirror image conversion method. The CAST representation shows the distinctive characteristics of several diastereomers and conformers that were examined. The method clearly represents the differences in configurations. Applications to organic molecules having complex stereochemistry are also demonstrated.
Journal Article↗
Two- and three-dimensional assessments of myocardial perfusion and function by using technetium-99m sestamibi gated SPECT with a combination of count- and image-based techniques.
BACKGROUND: Although the myocardial gated single photon emission computed tomography (SPECT) technique makes it possible to assess concurrent myocardial perfusion and function, quantitative methods for analyzing and displaying gated SPECT data in 2- and 3-dimensional presentations for regional and global cardiac assessment have not been established. METHODS AND RESULTS: We have developed an automated quantitative method for assessing perfusion and function by means of technetium-99m sestamibi gated SPECT with a computerized technique combining count-based and image-based methods. We have examined its validity in 91 patients by comparing its results with those of conventional techniques: contrast left ventriculography and radionuclide angiocardiography. In addition to color-scale displays of regional function, simultaneous 3-dimensional presentations of regional wall motion and perfusion have been produced. High reproducibility of gated SPECT analysis with this algorithm was demonstrated; interoperator errors (%CV) were 2.6% to 5.5%, and good intraobserver reproducibility was confirmed by means of high correlation coefficients (0.954 to 0.989). Left ventricular volumes assessed by means of contrast left ventriculography and by means of the gated SPECT technique showed significant correlations (left ventricular end-diastolic volume, y = 1.01x - 9.7, r = 0.845, P<.001, standard errors of the estimate [SEE] = 14 mL; left ventricular end-systolic volume, y = 1.03x - 1.4, r = 0.902, P<.001, SEE = 6 mL). Left ventricular ejection fraction determined by means of gated SPECT with the new algorithm closely correlated with that determined by means of radionuclide ventriculography (y = 1.05x - 0.6, r = 0.891, P<.001, SEE = 3 %). These parameters quantified by means of the present method correlated closely with those derived from the QGS program (r = 0.926 to 0.987). CONCLUSION: In comparison with conventional techniques, myocardial gated SPECT with automated quantitative analysis provides accurate and reproducible data for global and regional function. Quantitative concurrent assessment of myocardial perfusion and function by using 2-and 3-dimensional representations appears to be superior to other modalities and to contribute to nuclear cardiology practice.
Adult↗
Placental transfer of heavy metals in normal pregnant Japanese women.
To investigate the interrelation of heavy metals and the influence on next generation, total mercury and methylmercury, lead, cadmium, manganese, copper, zinc, and iron were determined in the maternal blood, placenta, umbilical cord, and umbilical cord blood. Samples were collected at delivery from 231 pregnant women who were living in the city of Nagoya, located in the central district of Japan, during 1974 and 1978. Total mercury and methylmercury, cadmium, and iron were higher in cord blood than in maternal blood, whereas copper and zinc were lower. Significant positive correlations were observed between maternal and cord blood with regard to total mercury and methylmercury, lead, cadmium, and manganese contents. Significant correlations were also observed between many pairs of metals, particularly in umbilical cord and its blood.
Air Pollutants↗
The effect of 9-ethyladenine on the photodimerization of 1-cyclohexylthymine.
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Adenine↗
Detection of cardiac calcinosis in hemodialysis patients by whole-body scintigraphy with 99m-technetium methylene diphosphonate.
A noninvasive method for the diagnosis of cardiac calcinosis, a life-threatening complication in hemodialysis patients with end-stage renal disease (ESRD), has not, as yet, been firmly established. We tested whether whole body scanning with 99m-technetium methylene diphosphonate (MDP) might visualize cardiac calcinosis. In 19 consecutive chronic hemodialysis ESRD patients (13 males and 6 females, aged 40-81, mean 63 +/- 8 years) with cardiovascular disease [mitral annular calcinosis and/or calcified aortic valve (n = 4), hemodialysis cardiomyopathy (n = 1), coronary artery disease (n = 9) and peripheral artery atherosclerotic disease (n = 6)], MDP uptake in the heart was compared to that in 7 non-ESRD controls with hyperparathyroidism due to adenoma. Cardiac and lung field MDP uptake was confirmed in only 3 (16%) and 5 (26%) of the 19 ESRD subjects, respectively, but was absent in controls. Positive cardiac uptake was related to cardiac calcified complications (mobile intracardiac calcinosis, myocardial calcinosis and mitral annular calcification) and the duration of hemodialysis (p = 0.015). While it was statistically insignificant, subjects showing MDP uptake were elder and had higher serum Ca or Ca x P product and lower intact parathyroid hormone levels. These results suggest that cardiac calcinosis in ESRD patients can be detected noninvasively by myocardial scintigraphy with 99m-technetium MDP.
Adult↗
Fetal hydrocephalus secondary to intraventricular hemorrhage diagnosed by ultrasonography and in utero fast magnetic resonance imaging. A case report.
Although fetal hydrocephalus is commonly detected by prenatal ultrasonographic examination, posthemorrhagic hydrocephalus has rarely been observed in the fetus. We report a case of hydrocephalus secondary to intraventricular hemorrhage (IVH) diagnosed by in utero magnetic resonance imaging (MRI) at 37 + 1 weeks of gestation. Ultrasonography revealed enlargement of the bilateral ventricles and an irregular mass measuring 20 x 12 x 10 mm in the right lateral ventricle. T1-weighted images with two-dimensional fast low-angle shot (2D-FLASH) and T2-weighted images with half-Fourier single-shot turbo spin echo (HASTE) demonstrated that an old hemorrhagic clot existed in the right lateral ventricle of the fetus. Hydrocephalus secondary to IVH was confirmed by postnatal MRI and ventriculoscopy. Fast MRI is especially useful for prenatal diagnosis of fetal brain abnormalities because it minimizes the artifact of fetal movement.
Adult↗
Efficacy and safety of the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor fluvastatin in hyperlipidemic patients treated with probucol.
The objective of this open trial was to investigate the efficacy and safety of the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor fluvastatin in hypercholesterolemic patients already receiving probucol. All of the participants had hypercholesterolemia. i.e. serum total cholesterol > or = 220 mg/dl, despite administration of probucol, 500 mg/day, for more than 4 weeks. After this, fluvastatin, 30 mg/day, was added to probucol treatment for 12 weeks. Twenty-seven patients were recruited into this study; all were evaluated for safety, and 22 were evaluated for efficacy. The addition of fluvastatin to the probucol regimen produced a significant further reduction in serum total and low-density lipoprotein cholesterol concentrations (of 18 and 20%, respectively; p < 0.001); these effects were fully established within 4 weeks of treatment and were maintained throughout the treatment. Fluvastatin did not affect the serum high-density lipoprotein cholesterol concentration. Fluvastatin treatment decreased serum triglyceride concentrations slightly in all patients (not significant); in patients with hypertriglyceridemia, triglyceride levels were decreased significantly by 34% (p < 0.01; serum triglycerides > or = 150 mg/dl). In addition, fluvastatin significantly decreased serum apolipoprotein B, C-II, C-III and E levels, whereas serum apolipoprotein A-I and A-II levels were unaffected. One patient complained of slight abdominal discomfort during fluvastatin administration, but relationship to fluvastatin remains unclear. One patient had slight elevation of the serum alanine aminotransferase level, and another patient had an elevated gamma-glutamyl transferase level. The addition of fluvastatin to probucol treatment can be considered to be an effective and well tolerated treatment in hypercholesterolemic patients.
Adult↗
Destruction of challenged endotoxin in a dry heat oven.
The amount and pyrogenicity of challenged endotoxin (derived from E. coli 055:B5, 10,000 endotoxin units, EU) processed in a dry heat oven at 200 degrees and 250 degrees C was measured and compared with the predicted amount and pyrogenicity calculated from destruction kinetics. The values for the assayed amount and pyrogenicity of the endotoxin processed in the dry heat oven at 200 degrees and 250 degrees C were fairly close to the predicted values. When the challenged endotoxin was exposed for 60 min in a dry heat oven at 200 degrees C, the amount of destruction did not reach a 3 log cycle reduction, although the pyrogenicity of the endotoxin was sufficiently reduced. However, at 250 degrees C for 30 min in the dry heat oven, the amount of endotoxin destroyed quickly reached a 3 log cycle reduction, and the pyrogenicity was quickly reduced to a sufficient level.
Chemical Phenomena↗
[Fatty acid metabolic and perfusion abnormalities in hypertrophied myocardium assessed by dual tracer tomography using thallium-201 and iodine-123-beta-methylpentadecanoic acid].
Fatty acid metabolic and perfusion abnormalities associated with cardiac hypertrophy were investigated using dual tracer tomography with thallium and a cardiac metabolic tracer, 15-(p-iodophenyl)-3-R, S-methylpentadecanoic acid (BMIPP), in eight patients with hypertrophic cardiomyopathy (HCM) and in three with hypertension (HT). Thallium and BMIPP uptakes were scored and analyzed in 143 segments (13/heart) by comparison with the left ventricular wall thickness measured by two-dimensional echocardiography. Complete agreement of both scores in HT patients was significantly higher than that in HCM patients (64% vs 24%, p < 0.001), while a lower BMIPP uptake compared to that of thallium (mismatching) was observed more frequently in HCM than in HT patients (65% vs 31%, p < 0.001). The wall thickness significantly (p < 0.005) correlated with BMIPP uptake score. HCM patients showed a low BMIPP uptake in 22 hypertrophic segments (59%) and 15 non-hypertrophic segments (41%), and reduced BMIPP uptake in 29% hypertrophic segments, while HT patients showed just five segments with decreased BMIPP uptake of which 4 were non-hypertrophic and only one hypertrophic. The left ventricular ejection fraction assessed by radionuclide ventriculography was normal and no regional wall motion abnormality was detected in any patient by echocardiographic and scintigraphic studies. Metabolic abnormalities detected by the iodine-123-beta-methyl fatty acid analog in hypertrophic cardiomyopathy may be independent of thallium myocardial perfusion, regional wall motion, or the magnitude of cardiac hypertrophy, suggesting that fatty acid imaging may be useful in investigating the pathogenesis and subclinical abnormality of hypertrophic cardiomyopathy, and differentiation from secondary, induced cardiac hypertrophy.
Adult↗
Destruction of typical endotoxins by dry heat as determined using LAL assay and pyrogen assay.
The kinetics of destruction by dry heat of two typical endotoxins, Escherichia coli 055:B5 (E. coli endotoxin) and Salmonella abortus equi (S. abortus equi endotoxin), were determined using the Limulus Amebocyte Lysate (LAL) and pyrogen assays. The efficiency of recovery of these endotoxins from carriers using a pyrogen assay was also determined simultaneously. In the LAL assay 0.1-10,000 EU was used and 10-1000 EU in the pyrogen assay. Recoveries of E. coli endotoxin and S. abortus equi endotoxin were, respectively, 49.7-92.0% and 27.0-70.1% by the LAL assay, and 31.1% and 60.6% by the pyrogen assay. Fourier transformation infrared (FT-IR) spectra demonstrated the presence of chemical structural differences between the two endotoxins. By dry heat (200 or 250 degrees C), there were no significant differences in the destruction kinetics between the two endotoxins; either endotoxin can therefore be adapted for use in the endotoxin challenge test. Destruction in the pyrogen assay was significantly quicker than that predicted by the LAL assay for each of the two endotoxins. In this endotoxin destruction system, 3 log cycle reduction (the United State Pharmacopeia (USP) recommendation for the depyrogenation process) could not be obtained by challenge with 10,000 EU of endotoxin under the depyrogenation conditions of 200 degrees C for 60 min (a set of conditions described in the European Pharmacopoeia (EP)), though little pyrogenicity remained. On the other hand, at 250 degrees C for 30 min (a set of conditions described in the EP, USP and Pharmacopoeia of Japan (JP)),a 3 log cycle reduction was achieved without any pyrogenicity remaining.
Drug Contamination↗
The effect of ulinastatin on cutaneous microcirculation during inhalation of 100% oxygen in a rabbit ear chamber.
This study aims to investigate the effects of ulinastatin, a human urinary trypsin inhibitor, on the cutaneous microcirculation during inhalation of 100% oxygen in the rabbit. Twenty-one rabbits having a rabbit ear chamber (REC), were divided into 2 groups: 11 rabbits without ulinastain treatment (Group C) and 10 rabbits with ulinastatin (Group U). After air inhalation, the inspired gas was changed to 100% oxygen. In Group U, 50,000 units of ulinastatin were administered before changing the concentration of inspired gas. The results suggests that ulinastatin may be useful for maintaining the cutaneous microcirculation during inhalation of 100% oxygen.
Animals↗
Effect of inhalation of nitrous oxide on rabbit ear chamber microvessels.
The purpose of this study is to investigate the effect of inhalation of nitrous oxide (N2O) on peripheral hemodynamics in vivo. We observed changes in the peripheral microcirculation before and during inhalation of 70% N2O -30% O2 for 2 hours, using rabbit ear chamber method in 16 rabbits. In summary, inhalation of N2O causes decrease of the diameters, blood-flow velocities, and blood-flow rates of arterioles; thus participating in the increase of systemic vascular resistance gradually during the first 5 minutes of N2O inhalation. This phenomenon (arteriole vasoconstriction) was maintained for 2 hours.
Administration, Inhalation↗